JP2001181423A - Porous resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous resin film having good water absorbability as a solvent for aqueous ink and aqueous paste, and to perform solid printing when a large amount of ink is ejected in ink jet recording. The present invention provides a recording medium capable of absorbing ink without density unevenness, and a porous resin film constituting a recording medium having such excellent properties. SOLUTION: The thermoplastic resin contains 30 to 80% by weight, a surface treating agent (A), and 70 to 20% by weight of an inorganic and / or organic fine powder surface-treated with the surface treating agent (B). A porous resin film, a recording medium using the porous resin film, and an ink jet recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous resin film excellent in water-based liquid absorption and ink absorption.
In addition, the present invention has particularly good ink jet recording characteristics,
The present invention also relates to a recording medium capable of forming a fine image.

[0002]

2. Description of the Related Art Conventionally, film-based synthetic papers having excellent water resistance are mainly composed of resin, and include offset printing and seal printing using oil-based inks or UV-curable inks, sublimation-type or melt-type thermal transfer. Has been the main use. However, with the expansion of applications, there is an increasing demand for a printing method using a water-based ink and an improvement in suitability for an environment-friendly water-based paste. For this reason, water-based inks and water-based pastes, or synthetic papers having good absorbency for water serving as a solvent for these are required. In addition, with the recent technological advances in multimedia, inkjet printers have become widespread for both commercial and consumer use. Ink jet printers have many features, such as easy multi-color and large-sized images and low printing cost. Above all, ink jet printers using water-based inks, which are less likely to cause environmental and safety problems than oil-based inks, have recently become mainstream.

[0003] Ink jet printers are widely used as a method of obtaining a hard copy including not only characters but also image processing. Therefore, the printed image is required to have higher definition. The image definition is
It depends on the drying properties of the ink printed on the recording medium.
For example, when printing is continuously performed on a plurality of recording media, another recording medium often overlaps the printed recording medium. At this time, if the ink absorption of the printed recording medium is insufficient, the ink adheres to the overlaid recording medium, causing image stains.

[0004] In order to enhance the definition of an image, a method of coating a recording medium such as synthetic paper, plastic film or paper with an ink receptive material having a hydrophilic resin or an inorganic fine powder has been widely adopted (particularly). Kaihei 3-
No. 82589, JP-A-9-216456).
On the other hand, an ink jet recording medium in which an ink receiving layer containing a hydrophilic resin as a main component is formed by a thermal lamination method or an extrusion lamination method has also been proposed (Japanese Patent Application Laid-Open Nos. 8-12871 and 9-1).
920, JP-A-9-314983). However, the recording medium for ink-jet formed by these methods has a case where the absorption capacity is insufficient when the discharge amount of the ink is large, so the coating layer needs to be thickened, and the coating process is required many times. There was a problem.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems of the prior art. That is, the present invention provides a porous resin film having good water absorbability as a solvent for aqueous inks and aqueous pastes, and provides a method of performing ink jet recording, which is capable of achieving uneven density even when solid printing is performed when a large amount of ink is ejected. It is an object of the present invention to provide a recording medium that can absorb ink without any problem. Another object of the present invention is to provide a porous resin film constituting a recording medium having such excellent properties.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies with the aim of solving the above-mentioned problems, and as a result, a thermoplastic resin, a surface treating agent (A) and a surface treating agent (B) were used. This is based on the finding that a porous resin film having an inorganic or organic fine powder surface-treated at a stage as a component has good absorption of an aqueous solvent or an aqueous ink. Preferably, "Japan TAPPI N
o. 51-87 ".
A porous resin film having a water contact angle of at least 110 ml / m ^2,
The present inventors have found that a porous resin film having a temperature of less than 1 ° C. can absorb ink without unevenness in density even when a large amount of ink is ejected, and is suitable as a recording medium such as an ink jet.

That is, the present invention relates to a porous resin film comprising a thermoplastic resin and an inorganic and / or organic fine powder surface-treated with a surface treating agent (A) and a surface treating agent (B). Japan TAPPI N
o. 51-87 ".
It is a porous resin film characterized by being in the range of 0.5 ml / m ² or more, and in a preferred embodiment, the film has an average contact angle to water of 110 ° or less, more preferably, It has pores inside and has a porosity of 10% or more. In a more preferred embodiment, the film has 1 × 10 ⁶ holes / m ^{2 on the surface.}
The average diameter of the pores on the surface is 0.01
It is preferably in the range of 50 μm. Further, it is preferable that at least a part of the inorganic and / or organic fine powder is present in pores on the surface and / or inside.

The thermoplastic resin is preferably a polyolefin resin, and the inorganic and / or organic fine powder preferably has an average particle diameter in the range of 0.01 to 20 μm. Furthermore, the specific surface area of the inorganic and / or organic fine powder is 0.5 m
Those in the range of ² / g or more are preferred. As a preferred embodiment of the mixing ratio of the constituent components, thermoplastic resins 30 to 90
% By weight, surface-treated inorganic and / or organic fine powder 7
0 to 10% by weight, and the amount of the surface treatment agent (A) is 0.01 to 100 parts by weight of the inorganic and / or organic fine powder.
-10 parts by weight, the amount of the surface treatment agent (B) is 0.01-10
It is in the range of parts by weight.

The preferred surface treatment agent is the surface treatment agent (A)
And the surface treatment agent (B) is selected from a sulfonate, a phosphate, a betaine, and a quaternary ammonium compound having a hydrocarbon group having 4 to 40 carbon atoms.
As a more preferred embodiment, the porous resin film is stretched. The present invention includes a laminate having a porous resin film on at least one surface thereof, a recording medium using the laminate, and an ink jet recording medium having a coloring material fixing layer provided thereon.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the porous resin film and the recording medium of the present invention will be described in detail. <Constituent Components> The porous resin film of the present invention comprises, as constituent components, inorganic and / or organic fine powder surface-treated with a thermoplastic resin, a surface treating agent (A) and a surface treating agent (B), and pores. .

As the thermoplastic resin used in the porous resin film of the present invention, ethylene resins such as high-density polyethylene, medium-density polyethylene and low-density polyethylene, polyolefin resins such as propylene resin, and polymethyl-1 -Pentene, ethylene-cyclic olefin copolymer, nylon-6, nylon-6,6, nylon-6,10, nylon-6,12, nylon-
6, T and other polyamide resins, polyethylene terephthalate and copolymers thereof, polyethylene naphthalate, aliphatic polyester and other thermoplastic polyester resins, polycarbonate, atactic polystyrene, syndiotactic polystyrene, and polyphenylene sulfide thermoplastic resins Is mentioned. These may be used in combination of two or more.

Among these, from the viewpoints of chemical resistance, low specific gravity, cost, etc., preferred are ethylene-based resins and polyolefin-based resins such as propylene-based resins.
More preferably, it is a propylene-based resin. Examples of the propylene-based resin include an isotactic polymer or a syndiotactic polymer obtained by homopolymerizing propylene. In addition, ethylene, 1-butene, 1-hexene, 1-heptene, 4-methyl-1-pentene and other α-olefins and propylene copolymerized, polypropylene having various stereoregularities as a main component. Copolymers can also be used. The copolymer may be a binary system, a ternary system or more, or a random copolymer or a block copolymer. The propylene-based resin is preferably used by blending a resin having a lower melting point than that of the propylene homopolymer in an amount of 2 to 25% by weight. High-density or low-density polyethylene can be exemplified as such a resin having a low melting point.

The type of the organic and / or inorganic fine powder used in the porous resin film of the present invention is not particularly limited, but specific examples thereof include the following. As the inorganic fine powder, heavy calcium carbonate, light calcium carbonate, aggregated light calcium carbonate, silica having various pore volumes, zeolite, clay, talc,
Examples thereof include a composite inorganic fine powder having an aluminum oxide or a hydroxide around a core of a hydroxyl group-containing inorganic fine powder such as titanium oxide, barium sulfate, zinc oxide, magnesium oxide, diatomaceous earth, silicon oxide, and silica.

For the purpose of forming pores, the organic fine particles are selected from those having a higher melting point or glass transition point than the thermoplastic resin used as the above-mentioned non-hydrophilic thermoplastic resin and being incompatible with each other. Specific examples include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, polystyrene, polymers or copolymers of acrylate or methacrylate, melamine resin, polyethylene sulfite, polyimide, polyethyl ether ketone , Polyphenylene sulfide, and the like.

Among them, as the non-hydrophilic thermoplastic resin,
When a polyolefin resin is used, a resin obtained from polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, or polystyrene is preferable. Further, an anionic surfactant, a monomer having an anionic structure in the molecule or a cationic surfactant, or an anionic polymer obtained by polymerization using a monomer having a quaternary ammonium structure in the molecule. If it is a particle of a coalesced or cationic polymer, it can be treated as equivalent to a fine powder which has been surface-treated with an anionic surface treating agent or a cationic surface treating agent.

Among inorganic and / or organic fine powders,
From the viewpoint that the amount of heat generated during combustion is small, inorganic fine powder is more preferable. Among them, heavy calcium carbonate, clay, and diatomaceous earth are preferred because they are inexpensive, and when formed by stretching, have good porosity. The average particle size of the inorganic and / or organic fine powder used in the present invention is preferably 0.1 to 20 μm, more preferably 0.1 to 10 μm, and still more preferably 0.5 to 5 μm.
m. For the purpose of improving the absorptivity of the aqueous solvent or the aqueous ink, the larger the particle size, the better the particle size is, preferably, 0.01 μm or more. In addition, from the viewpoint that it is difficult to cause troubles such as breakage of the sheet at the time of stretching and a decrease in the strength of the surface layer in the case where pores are generated inside to improve the absorbency by stretching, the thickness is preferably 20 μm or less.

The particle size of the surface-treated inorganic or organic fine powder used in the present invention is, for example, a particle measuring device, for example, a laser diffraction type particle measuring device "Microtrack" (trade name, manufactured by Nikkiso Co., Ltd.) Can be measured by the particle size corresponding to 50% in cumulative (measured particle size). The particle size of the fine powder dispersed in the non-hydrophilic resin or the hydrophilic resin by melt-kneading and dispersion is determined by measuring at least 20 of the particles by electron microscopic observation of the cross section of the porous film and calculating the particle size accumulation. , An average value. The specific surface area of the inorganic or organic fine powder used in the present invention is measured by the BET method, 0.1~1000m ² / g as an example, and more preferably 0.2~500m ² / g, more preferably, 0.5
１００100 m ² / g.

When inorganic and / or organic fine powder having a large specific surface area is used, the absorption of an aqueous solvent or ink tends to be improved. In addition, in the case of mixing and dispersing with a hydrophilic thermoplastic resin or a non-hydrophilic thermoplastic resin, when there is a tendency that troubles such as insufficient dispersion by classification and foaming due to accompanying air tend to occur, a specific surface area suitable for use. The upper limit is appropriately selected. Also, various oil absorptions can be used. For example, the oil absorption (JIS-K5101-
1991) is in the range of 1 to 300 ml / 100 g, preferably 10 to 200 ml / g. As the fine powder used for the porous resin film of the present invention, one kind may be selected from the above and used alone, or two or more kinds may be used in combination. When two or more kinds are used in combination, a combination of an organic fine powder and an inorganic fine powder may be used.

Hereinafter, the surface treating agent (A) used in the present invention.
And the surface treatment agent (A), respectively, "treatment agent (A)",
Abbreviated as "treatment agent (B)". The following are specific examples of the surface treatment agent, which are appropriately selected so as to obtain the effects of the present invention. The treating agent (A) is a cationic surface treating agent (K1), an anionic surface treating agent (L1), an amphoteric surface treating agent (M1), or a nonionic surface treating agent (N1).
It is selected from various types of surface treatment agents.

The cationic surface treating agent (K1), abbreviated as treating agent (K1): Examples of the treating agent (K1) include the following. That is, it has 4 to 30 carbon atoms, preferably 1 carbon atom.
Examples of the ammonium compound having a hydrocarbon group in the range of 0 to 20 include those represented by the following general formula. ^{R 1 XN + R 2 R 3} R 4 · Y - _{[X: -CH 2 -, - CONHCH} 2 CH 2 -, - CO
_{NHCH 2 CH 2 CH 2 -,} - NHCOCH 2 -, - N
_{HCOCH 2 CH 2 -, - COOCH} 2 CH 2 -, - C
OOCH ₂ CH ₂ CH ₂ —, —OCOCH ₂ —, or —OCOCH ₂ CH ₂ —R ¹ : an alkyl group having 10 to 20 carbon atoms R ² : an alkyl group having 1 to 20 carbon atoms R ³ : methyl , Ethyl, or polyalkyleneoxy group R ⁴ : methyl, ethyl, or polyalkyleneoxy group Y ⁻ : chloride ion, bromide ion, hydroxide ion,
Anions selected from methanesulfonate, ethanesulfonate, methylsulfate, ethylsulfate, nitrate, sulfate, or acetate]

Specific examples of R ¹ include undecyl, lauryl, tridecyl, cetyl, pentadecyl,
Examples include a stearyl group and an oleyl group. Specific examples of R ² include a methyl group, an ethyl group, a propyl group, a lauryl group, a cetyl group, and a stearyl group. R ³ and R
Specific examples of ⁴ include, in addition to a methyl group and an ethyl group,
-Hydroxyethyl group, 2- (2-hydroxyethyl)
Examples include an ethyl group, a trioxyethyleneoxy group, a tetraoxyethyleneoxy group, a pentaoxyethyleneoxy group, and a hexaoxyethyleneoxy group. Furthermore, ammonium such as laurylamine or coconutamine, lauryldimethylbenzylammonium, chlorides such as imidazolinium-type quaternary ammonium, bromide, hydroxide, methosulfate, ethosulfate, nitrate, sulfate or acetate and the like. Can be Further, among these ammonium compounds, an ammonium compound having a hydrocarbon group having 10 to 20 carbon atoms represented by the above general formula is preferable.

Hereinafter, the "salt" in the cationic treating agent (K1) means that the anion forming the salt is chloride ion, bromide ion, sulfate ion, nitrate ion, methyl sulfate ion, ethyl sulfate ion, methanesulfonic acid. Shown are those selected from ions. The treating agent (K1) of the present invention also contains a cationic polymer. Specifically, an epichlorohydrin adduct of a polyamine polyamide or an epichlorohydrin resin is used for preparing glycidyltrimethylammonium chloride or metsulfate. Cationized polymer obtained by modification with such, cationized polyvinyl alcohol obtained by modifying polyvinyl alcohol with glycidyltrimethylammonium chloride or metsulfate,
Ammonium polymer obtained by modifying polyethylene imine with methyl chloride, methyl bromide, ethyl chloride, ethyl bromide, dimethyl sulfate, diethyl sulfate, glycidyl trimethyl ammonium chloride, etc., the following cationic monomers (a
Copolymers of 1) and the nonionic hydrophilic vinyl monomer (a2) are exemplified.

In the copolymer of the cationic monomer (a1) and the nonionic hydrophilic vinyl monomer (a2), (a)
Specific examples of 1) include methacryloyloxyethyltrimethylammonium, acryloyloxyethyltrimethylammonium, methacryloyloxyethyldimethylethylammonium and acryloyloxyethyldimethylethylammonium chloride, bromide,
Methosulfate or ethosulfate, N, N
-Dimethylaminoethyl methacrylate or N, N-dimethylaminoethyl acrylate for epichlorohydrin,
And quaternary ammonium salts obtained by alkylation with an epoxy compound such as glycidol and glycidyltrimethylammonium chloride.

Of these, methacryloyloxyethyltrimethylammonium methosulfate or chloride, acryloyloxyethyltrimethylammonium methosulfate or chloride, methacryloyloxyethyldimethylethylammonium ethosulfate or chloride or acryloyloxyethyldimethylethylammonium ethosulfate is preferred. Or chloride. (A1) as a component constituting the copolymer is obtained by copolymerizing the tertiary amine compound corresponding to the above quaternary ammonium with (a2), and then methyl chloride, methyl bromide, ethyl chloride, ethyl bromide, dimethyl sulfate, It may be a quaternary ammonium salt modified with diethyl sulfate, glycidyltrimethylammonium chloride or the like.

Specific examples of (a2) include acrylamide, methacrylamide, N-vinylformamide, N-
Vinylacetamide, N-vinylpyrrolidone, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate,
(Meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, and (meth) acrylic acid butyl ester, and among these, acrylamide and methacrylamide are preferable. (A1) is 10 to 99 mol%, preferably 50 to 97 mol%, and (a2) is 90 to 1 mol%, preferably 50 to 3 mol%.

The above-mentioned monomer is dissolved in an aqueous medium or an organic solvent,
Using a water-soluble initiator exemplified by ammonium persulfate, 2,2-azobis (2-amidinopropane) dihydrochloride and the like, 40 ° C to 100 ° C, for example, 50 ° C
It can be obtained by reacting at ８０80 ° C. for 2 to 24 hours. When expressed as a weight average molecular weight measured by gel permeation chromatography (GPC), about 5
000 to 500,000, preferably 10,000 to 120
000, and more preferably in the range of 10,000 to 100,000.

Of these, lauryl trimethyl ammonium chloride or methosulfate, lauryl dimethyl ethyl ammonium chloride or ethosulfate, 3-lauroylaminopropyl dimethyl (2-hydroxyethyl) nitrate,
It is a mixture of dilauryl di (diethyleneoxy) ammonium chloride and dilauryl (2-hydroxyethyl) (trioxyethyleneoxy) chloride. In addition,
Starch, cellulose, cationic starch and cationic guar gum based on diene polymers such as natural rubber and latex have insufficient heat resistance when producing the porous resin film of the present invention, and are used in the present invention. It is not included in the category of the surface treatment agent.

An anionic surface treating agent (L1), abbreviated as treating agent (L1): As an example of treating agent (L1), C 4 -C 4
A sulfonate having a hydrocarbon group in the range of 40, a phosphate salt having a hydrocarbon group in the range of 4 to 40 carbon atoms, a carboxylate having a hydrocarbon group of the range of 4 to 40 carbon atoms, or a polymer Type anionic surface treatment agent. "Salt" in the following treating agent (L1)
Lithium salt, sodium salt, potassium salt, calcium salt, magnesium salt, 1-4 quaternary ammonium salt, 1-4
It shows a quaternary phosphonium salt, and preferred as the salt are a lithium salt, a sodium salt, a potassium salt, and a quaternary ammonium salt, and more preferably a sodium salt or a potassium salt.

As the sulfonate having a hydrocarbon group having 4 to 40 carbon atoms, the sulfonate having 4 to 40 carbon atoms, preferably 8 carbon atoms.
A sulfonic acid salt having a hydrocarbon group having a linear or branched or cyclic structure in the range of from 20 to 20; a salt of a sulfoalkanecarboxylic acid; specifically, a sulfonic acid salt having a carbon number of 4 to 40, preferably 8 to 20; Alkyl benzene sulfonic acid salt, salt of naphthalene sulfonic acid, preferably having 4 to 30 carbon atoms,
A salt of an alkylnaphthalenesulfonic acid having a linear or branched or cyclic structure in the range of 8 to 20; Sulfonic acid salt; having 1 to 30 carbon atoms, preferably 8 to 20 carbon atoms
A salt of an alkanesulfonic acid having a linear, branched or cyclic structure in the range of: 1 to 30 carbon atoms, preferably a salt of an alkyl sulfate in the range of 8 to 20; a salt of a sulfoalkanecarboxylic acid ester; 8 to 30 carbon atoms Preferably 10
Sulfonates of alkylene oxide adducts of alkyl alcohols in the range of 20 and the like.

Specific examples thereof include salts of alkanesulfonic acid and aromatic sulfonic acid, that is, octanesulfonic acid salt, dodecanesulfonic acid salt, tetradecanesulfonic acid, hexadecanesulfonic acid salt, octadecanesulfonic acid salt, Or 2-dodecylbenzenesulfonate, 1- or 2-hexadecylbenzenesulfonate, 1- or 2-octadecylbenzenesulfonate, various isomers of dodecylnaphthalenesulfonate, β-naphthalenesulfonic acid formalin condensation Salt of things,
Various isomers of octylbiphenylsulfonate, dodecylbiphenylsulfonate, various isomers of dodecylphenoxybenzenesulfonate, dodecyldiphenyletherdisulfonate, ligninsulfonate; alkyl sulfate, ie, dodecyl sulfate , Hexadecyl sulfate; salts of sulfoalkanecarboxylic acids, ie, dialkyl esters of sulfosuccinic acid;
Those in which the alkyl group has a linear or branched or cyclic structure having 1 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more specifically, a salt of di (2-ethylhexyl) sulfosuccinate, N-methyl-N- (2-sulfoethyl) alkylamide salt (the alkyl group has 1 to 30 carbon atoms, preferably 12 carbon atoms)
18), for example, an amide compound derived from N-methyltaurine and oleic acid, having 1 to 30 carbon atoms, preferably 1
Salts of 2-sulfoethyl esters of carboxylic acids of 0 to 18; triethanolamine lauryl sulfate, ammonium lauryl sulfate; polyoxyethylene lauryl sulfate, polyoxyethylene cetyl sulfate, having 8 to 30 carbon atoms, preferably 10 to 20 carbon atoms. Sulfonates of alkylene oxide adducts of alkyl alcohols, for example, sulfates of ethylene oxide adducts of lauryl alcohol,
Sulfate of ethylene oxide adduct of cetyl alcohol, sulfate of ethylene oxide adduct of stearyl alcohol, and the like.

Examples of the phosphoric acid ester salt having a hydrocarbon group having 4 to 40 carbon atoms include a hydrocarbon group having a linear or branched or cyclic structure having 4 to 40 carbon atoms, preferably 8 to 20 carbon atoms. Phosphoric acid mono- or di- having
Ester salts, preferably phosphoric acid mono- or di-ester salts having a hydrocarbon group having a linear or branched or cyclic structure having a carbon number in the range of 8 to 20;
Preferred are salts of mono- or diester phosphates of higher alcohols in the range of 8 to 20, and salts of phosphate esters of ethylene oxide adducts of higher alcohols in the range of 4 to 40, preferably 8 to 20 carbon atoms. Specific examples thereof include disodium dodecyl phosphate or dipotassium salt, disodium hexadecyl phosphate or dipotassium salt, dodecyl alcohol, disodium salt of monoester phosphate of ethylene oxide adduct of cetyl alcohol or stearyl alcohol. Or dipotassium salt, sodium salt or potassium salt of phosphoric acid diester of ethylene oxide adduct of stearyl alcohol, and the like.

Further, examples of the polymer anionic surface treating agent include salts of polyacrylic acid, salts of acrylic acid polymers such as polyacryl-maleic acid, and salts of copolymers of styrene sulfonic acid. Of these, preferably, sodium or potassium salt of dodecanesulfonic acid, sodium or potassium salt of tetradecanesulfonic acid, sodium or potassium salt of hexadecanesulfonic acid, sodium or potassium salt of di (2-ethylhexyl) sulfosuccinate Salts, sodium or potassium salts of dodecylbenzenesulfonic acid, and sodium or potassium salts of acrylic acid polymers.

The amphoteric surface treating agent (M1), abbreviated as treating agent (M1): As an example of treating agent (M1), the number of carbon atoms is 4 to 40.
Preferred are alkyl betaines and alkyl sulfo betaines having a hydrocarbon group in the range of 10 to 20, and specific examples thereof include lauryl dimethyl betaine, stearyl dimethyl betaine, dodecyl dimethyl (3-sulfo propyl) ammonium inner salt, and cetyl dimethyl ( 3
-Sulfopropyl) ammonium inner salt, stearyldimethyl (3-sulfopropyl) ammonium inner salt, 2-octyl-N-carboxymethyl-
N-hydroxyethylimidazolinium betaine, 2-
Lauryl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, and the like.

Further, the treating agent (M1) of the present invention also contains a cationic-anionic amphoteric polymer having an alkylbetaine structure in the molecule. Examples thereof include polyethyleneimine, polyamine polyamide, and polyvinylamine. Amino group-containing polymers such as amines, polyvinyldialkylamines, polyallylamines, and polyallyldialkylamines are used to prepare chloroacetic acid and its salts, bromoacetic acid and its salts, chloropropionic acid and its salts, bromopropionic acid and its salts, and chloromethanesulfonic acid. And its salts, bromomethanesulfonic acid and its salts, chloroethanesulfonic acid and its salts,
Examples thereof include polymers having a structure obtained by modification with bromoethanesulfonic acid or a salt thereof or, if necessary, further neutralization.

Further, a monomer having the following amphoteric structure:
(A3) Polymer or nonionic hydrophilic vinyl
And a copolymer with the monomer (a4). Bisexual
As specific examples of the monomer (a3) having a structure,
A monomer represented by the general formula: H_TwoC = CR^Five(-COOR⁶−) N⁺R⁷R⁸(R⁹
COOM) ・ Y^- [R^Five: Hydrogen atom or methyl group R⁶: Ethylene group, propylene group, butylene group, -CO
OCH_Two-, -COOCH_TwoCH_Two-, -COOCH_Two
CH_TwoCH_Two-Or -COOCH_TwoCH _TwoCH
_TwoCH_Two− R⁷: Methyl, ethyl or polyalkyleneoxy
Group R⁸: Methyl, ethyl or polyalkyleneoxy
Group R⁹: Methylene group, ethylene group, propylene group, or
Is a butylene group M: sodium or potassium Y^-: Chloride ion, bromide ion, hydroxide ion,
Methanesulfonic acid ion, ethanesulfonic acid ion,
Cyl sulfate ion, ethyl sulfate ion, nitrate ion, sulfuric acid
Ion or anion selected from acetate ion)

(A3) as a component constituting the copolymer
Is obtained by copolymerizing the tertiary amine compound corresponding to the above quaternary ammonium with (a4) and then chloroacetic acid or a salt thereof, bromoacetic acid or a salt thereof, chloropropionic acid or a salt thereof, bromopropionic acid or a salt thereof, chloromethane It may be modified with sulfonic acid or a salt thereof, bromomethanesulfonic acid or a salt thereof, chloroethanesulfonic acid or a salt thereof, or bromoethanesulfonic acid or a salt thereof, or further neutralized as necessary to form an amphoteric group. . Specific examples of the copolymerizable nonionic hydrophilic monomer (a4) include acrylamide, methacrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, 2-hydroxyethyl methacrylate, and 2-hydroxyethyl acrylate. , 2-hydroxypropyl (meth) acrylate,
Examples thereof include 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, and (meth) acrylic acid butyl ester. Of these, acrylamide and methacrylamide are preferable. .

(A3) is 30 to 100 mol%, preferably 50 to 97 mol%, and (a4) is 70 to 0 mol%, preferably 50 to 3 mol%. In the aqueous medium or organic solvent, according to the solubility with the solvent,
A water-soluble initiator such as ammonium persulfate and 2,2-azobis (2-amidinopropane) dihydrochloride for an aqueous medium, and AIBN for an organic solvent.
Using an organic azo compound or an organic peroxide such as
2 to 2 hours at 50 to 80 ° C. as an example.
It can be obtained by reacting for 4 hours. In addition, when represented by a weight average molecular weight measured by gel permeation chromatography (GPC), about 5,000 to 500,000,
Preferably, it is in the range of 10,000 to 120,000, more preferably 10,000 to 100,000.

Nonionic surface treating agent (N1), abbreviated as treating agent (N1): as an example of treating agent (N1), a carbon number of 8 to
Higher aliphatic alcohols having an alkyl group having 8 to 40 carbon atoms, preferably 10 to 20 carbon atoms, higher aliphatic amines having 8 to 40 carbon atoms, preferably 10 to 20 carbon atoms; And ethylene oxide adducts of higher fatty acid amides having a molecular weight of about 3000 or less, preferably 1000 or less. Specific examples thereof include ethylene oxide adducts of lauryl alcohol and ethylene oxide adducts of cetyl alcohol. , Stearyl alcohol ethylene oxide adduct, octylphenol ethylene oxide adduct, dodecylphenol ethylene oxide adduct, stearic acid ethylene oxide adduct, oleic acid ethylene oxide adduct, lauric acid ethylene oxide adduct, laurylamine Ethylene oxide adduct Ethylene oxide adducts of Riruamin,
Examples include ethylene oxide adducts of lauric acid amide, ethylene oxide adducts of stearic acid amide, ethylene oxide adducts of oleic acid amide, and phosphoric acid triesters of ethylene oxide adducts of dodecyl alcohol, cetyl alcohol or stearyl alcohol.

The surface treating agent (B) includes four kinds of a cationic surface treating agent (K2), an anionic surface treating agent (L2), an amphoteric surface treating agent (M2), and a nonionic surface treating agent (N2). Selected from the above surface treatment agents. Cationic surface treatment agent (K2), abbreviation is treatment agent (K
2): Examples of the treatment agent (K2) include the following. That is, it has 4 to 30 carbon atoms, preferably 10 to 20 carbon atoms.
Examples of the ammonium compound having a hydrocarbon group in the range include those represented by the following general formula. ^{R 1 XN + R 2 R 3} R 4 · Y - _{[X: -CH 2 -, - CONHCH} 2 CH 2 -, - CO
_{NHCH 2 CH 2 CH 2 -,} - NHCOCH 2 -, - N
_{HCOCH 2 CH 2 -, - COOCH} 2 CH 2 -, - C
OOCH ₂ CH ₂ CH ₂ —, —OCOCH ₂ —, or —OCOCH ₂ CH ₂ —R ¹ : an alkyl group having 10 to 20 carbon atoms R ² : an alkyl group having 1 to 20 carbon atoms R ³ : methyl , Ethyl, or polyalkyleneoxy group R ⁴ : methyl, ethyl, or polyalkyleneoxy group Y ⁻ : chloride ion, bromide ion, hydroxide ion,
Anions selected from methanesulfonate, ethanesulfonate, methylsulfate, ethylsulfate, nitrate, sulfate, or acetate]

Specific examples of R ¹ include an undecyl group, a lauryl group, a tridecyl group, a cetyl group, a pentadecyl group, a stearyl group and an oleyl group. Specific examples of R ² include a methyl group, an ethyl group, a propyl group, a lauryl group,
A cetyl group and a stearyl group. Specific examples of R ³ and R ⁴ include, in addition to a methyl group and an ethyl group, a 2-hydroxyethyl group, a 2- (2-hydroxyethyl) ethyl group, a trioxyethyleneoxy group, a tetraoxyethyleneoxy group, and a pentaoxy group. Examples include an ethyleneoxy group and a hexaoxyethyleneoxy group.

Further, chlorides such as ammonium derived from laurylamine or coconutamine, lauryldimethylbenzylammonium, imidazolinium type quaternary ammonium, etc., bromide, hydroxide, metsulfate, ethosulfate, nitrate, sulfate or acetate, etc. Is mentioned. Further, among these ammonium compounds, an ammonium compound having a hydrocarbon group having 10 to 20 carbon atoms represented by the above general formula is preferable. Of these, preferably, lauryl trimethyl ammonium chloride or methosulfate, lauryl dimethyl ethyl ammonium chloride or ethosulfate, 3-lauroylaminopropyl dimethyl (2-hydroxyethyl) nitrate, dilauryl di (diethyleneoxy)
It is a mixture of ammonium chloride and dilauryl (2-hydroxyethyl) (trioxyethyleneoxy) chloride.

An anionic surface treating agent (L2), abbreviated as treating agent (L2): Examples of treating agent (L2) include carbon atoms of 4
A sulfonate having a hydrocarbon group in the range of 40 to 40, a phosphate ester salt having a hydrocarbon group in the range of 4 to 40 carbon atoms, a carboxylate having a hydrocarbon group of the range of 4 to 40 carbon atoms, or Polymer-type anionic surface treatment agents are exemplified. The “salt” in the following treating agent (L2)
Lithium salt, sodium salt, potassium salt, calcium salt, magnesium salt, 1-4 quaternary ammonium salt, 1-4
It shows a quaternary phosphonium salt, and preferred as the salt are a lithium salt, a sodium salt, a potassium salt, and a quaternary ammonium salt, and more preferably a sodium salt or a potassium salt.

As the sulfonate having a hydrocarbon group having 4 to 40 carbon atoms, a sulfonate having 4 to 40 carbon atoms, preferably 8 to 40 carbon atoms.
A sulfonate or a sulfoalkanecarboxylate having a hydrocarbon group having a linear or branched or cyclic structure in the range of from 20 to 20, specifically, an alkylbenzene having from 4 to 40, preferably from 8 to 20 carbon atoms. Sulfonate, salt of naphthalenesulfonic acid, having 4 to 30 carbon atoms, preferably 8 to
Alkyl naphthalene sulfonic acid salts having a linear or branched or cyclic structure in the range of 20; diphenyl ethers and biphenyl sulfonic acids having an alkyl group having a linear or branched structure in the range of 1 to 30, preferably 8 to 20 carbon atoms Salt; a salt of an alkanesulfonic acid having a linear or branched or cyclic structure having 1 to 30 carbon atoms, preferably 8 to 20 carbon atoms; a salt of an alkyl sulfate having 1 to 30 carbon atoms, preferably 8 to 20 carbon atoms; Alkane carboxylate salt; C8-30, preferably C10-10
Sulfonates of alkylene oxide adducts of alkyl alcohols in the range of 20 and the like.

Specific examples thereof include alkanesulfonic acid and aromatic sulfonic acid, that is, octanesulfonic acid salt, dodecanesulfonic acid salt, tetradecanesulfonic acid, hexadecanesulfonic acid salt, octadecanesulfonic acid salt, 1- or 2 Various isomers of dodecylbenzenesulfonate, 1- or 2-hexadecylbenzenesulfonate, 1- or 2-octadecylbenzenesulfonate, dodecylnaphthalenesulfonate,
salts of β-naphthalenesulfonic acid formalin condensate, various isomers of octylbiphenylsulfonate, various isomers of dodecylbiphenylsulfonate, dodecylphenoxybenzenesulfonate, dodecyldiphenylether disulfonate, ligninsulfonate Alkyl sulfates, ie, dodecyl sulfate, hexadecyl sulfate; sulfoalkanecarboxylic acid salts, ie, dialkyl esters of sulfosuccinic acid, wherein the alkyl group has 1 to 30 carbon atoms, preferably 4 to 20 carbon atoms. Those having a linear or branched or cyclic structure, more specifically, salts of di (2-ethylhexyl) sulfosuccinate;
N-methyl-N- (2-sulfoethyl) alkylamide salt (the alkyl group has 1 to 30 carbon atoms, preferably 12 to 1 carbon atom)
8) For example, an amide compound derived from N-methyltaurine and oleic acid, having 1 to 30 carbon atoms, preferably 10 to 10 carbon atoms
Salt of 2-sulfoethyl ester of carboxylic acid of 18; triethanolamine lauryl sulfate, ammonium lauryl sulfate; polyoxyethylene lauryl sulfate, polyoxyethylene cetyl sulfate, having 8 to 30 carbon atoms, preferably
Sulfonate of alkylene oxide adduct of alkyl alcohol having 10 to 20 carbon atoms, for example, sulfate of ethylene oxide adduct of lauryl alcohol, sulfate of ethylene oxide adduct of cetyl alcohol, ethylene oxide adduct of stearyl alcohol And the like.

Examples of the phosphoric acid ester salt having a hydrocarbon group having 4 to 40 carbon atoms include a hydrocarbon group having a linear or branched or cyclic structure having 4 to 40 carbon atoms, preferably 8 to 20 carbon atoms. Phosphoric acid mono- or di-ester salts, preferably phosphoric acid mono- or di-ester salts having a hydrocarbon group having a linear, branched or cyclic structure having a carbon number of 8 to 20; Salts of mono- or diester phosphates of higher alcohols in the range of 4 to 40, preferably 8 to 20, preferably 4 to 40, preferably 8 to 8 carbon atoms.
And salts of phosphate esters of ethylene oxide adducts of higher alcohols in the range of -20 to 20.

Specific examples thereof include disodium dodecyl phosphate or dipotassium phosphate, disodium hexadecyl phosphate or dipotassium phosphate, dodecyl alcohol, cetyl alcohol, and disodium monoester phosphate of ethylene oxide adduct of stearyl alcohol. Salts or dipotassium salts, sodium or potassium salts of phosphoric diesters of ethylene oxide adducts of stearyl alcohol, and the like. Among them, preferably, sodium or potassium salt of dodecanesulfonic acid, sodium or potassium salt of tetradecanesulfonic acid, sodium or potassium salt of hexadecanesulfonic acid, sodium or potassium salt of di (2-ethylhexyl) sulfosuccinate And sodium salts or potassium salts of dodecylbenzenesulfonic acid.

The amphoteric surface treating agent (M2), abbreviated as treating agent (M2): As an example of treating agent (M2), the number of carbon atoms is 4 to 40.
As specific examples of alkyl betaines and alkyl sulfo betaines having preferably a hydrocarbon group in the range of 10 to 20,
Lauryl dimethyl betaine, stearyl dimethyl betaine, dodecyldimethyl (3-sulfopropyl) ammonium inner salt, cetyl dimethyl (3-sulfopropyl) ammonium inner salt, stearyl dimethyl (3-sulfopropyl) ammonium inner salt, 2-octyl-N- Carboxymethyl-N-hydroxyethylimidazolinium betaine, 2-lauryl-
N-carboxymethyl-N-hydroxyethylimidazolinium betaine and the like.

Nonionic surface treating agent (N2), abbreviation is treating agent (N2): Abbreviation is treating agent (N2) selected from the same nonionic surface treating agents (N1) as described above. In the present invention, the combination of the first-stage surface treatment agent (A) and the second-stage surface treatment agent (B) is optional, but is preferably
Treatment agent (K1) / treatment agent (K2), treatment agent (K1) / treatment agent (L2), treatment agent (K1) / treatment agent (M2), treatment agent (K1) / treatment agent (N2), treatment agent (L1) / treatment agent (K2), treatment agent (L1) / treatment agent (L2), treatment agent (L1) / treatment agent (M2), treatment agent (L1) / treatment agent (N2), treatment agent (N1) ) / Treatment agent (K2), treatment agent (N1) / treatment agent (L2), treatment agent (N1) / treatment agent (N2), treatment agent (N1) / treatment agent (M2), more preferably treatment Agent (K1) / treatment agent (K2), treatment agent (K1) / treatment agent (L2), treatment agent (K1) / treatment agent (M2), treatment agent (L1) / treatment agent (K2), treatment agent ( L1) / treatment agent (L2), treatment agent (L1) / treatment agent (M2), more preferably treatment agent (K1) / treatment agent (K2), (K1) / treatment agent L2), the processing agent (L
1) / treatment agent (K2), treatment agent (L1) / treatment agent (L
2). The surface treating agent within the above range has a large effect of improving the absorbability of the porous resin film of the present invention with an aqueous solvent or an aqueous ink.

(Surface Treatment Aid) A surface treatment aid can be used in combination with these surface treatment agents as long as their effects are not impaired. The amount of the surface treatment aid is 30% by the total amount of the surface treatment agent and the surface treatment aid as 100% by weight.
% By weight, preferably 20% by weight or less. Specific examples of the surface treatment auxiliary include amide compounds of higher fatty acids having 4 to 40 carbon atoms and higher alcohols, and specific examples thereof include stearamide, ethylenebisstearic amide, and N-methyl. Examples include stearic acid amide, N-ethylstearic acid amide, oleic acid amide, behenic acid amide, lauroyl monoethanolamide, stearoyl monoethanolamide, lauryl diethanolamine, stearyl diethanolamine, lauryl alcohol, and stearyl alcohol.

(Surface Treatment Method for Inorganic and / or Organic Fine Powder) In the present invention, after the treating agent (A) is adhered to the surface of the inorganic and / or organic fine powder in the first step and subjected to surface treatment, Next, as a second step, the surface treatment is performed by adhering the treating agent (B) to the surface. As the surface treatment method, various known methods can be applied, and there is no particular limitation. The mixing device and the temperature and time of mixing are also appropriately selected according to the properties and physical properties of the components used. The L / D (shaft length / shaft diameter) of the various mixers used, the shape of the stirring blades, the speed of the sedan, the specific energy, the residence time, the processing time, the processing temperature, etc. are selected according to the properties of the components used. It is possible.

As the treatment method of the first stage, (I) the treatment agent (A) is dissolved or dispersed in a powder, a liquid, a paste, a solvent such as water or an organic solvent, or When a solvent is used in the production of (A), the solvent is not removed, or a part thereof is removed, and a fine powder is obtained in the form of a solution or dispersion of the treating agent (A) having an appropriate concentration. (II) adding the treating agent (A) to the fine powder suspended in a solvent such as water or an organic solvent. Or conversely, dissolving the treating agent (A) in a solvent, adding the fine powder, mixing the two, removing the solvent, drying and attaching to the periphery of the fine powder, (III)
In the case of fine powder produced by a dry or wet pulverization method, a treatment agent (A) is added before or during pulverization and adhered to the periphery of the fine powder in the pulverization process;

(IV) A required amount of the treating agent (A) is added to a part of the fine powder to be used at a concentration higher than the required concentration to prepare a master batch composed of the fine powder and the treating agent (A). A method of mixing with the remaining fine powder, adhering around the fine powder and mixing with the thermoplastic resin, (V) in the case of an organic fine powder synthesized by polymerization, before, during or after the polymerization, A method in which the treating agent (A) is added to a powder in the form of a powder, a liquid, a paste, or dissolved or dispersed in a solvent, and adhered to the periphery of the organic fine powder. In the case of an organic filler dispersed in a thermoplastic resin continuous phase, a melt-kneading is performed by adding a surface treatment agent to a thermoplastic resin or an undispersed organic filler or a mixture of a thermoplastic resin and an undispersed filler during melt-kneading. Organic The method of depositing a surface treatment agent on the periphery of the organic filler in the process of the filler finely dispersed, and the like.

Among these, in the case of inorganic fine powder produced by wet pulverization, for example, calcium carbonate particles, a required amount of treatment is applied to 100 parts by weight of heavy calcium carbonate particles having a relatively large particle size of 10 to 50 μm. In the presence of the agent (A), the mixture is wet-pulverized in an aqueous medium to a desired particle size, and then dried. It can be obtained by drying. As the raw material calcium carbonate, heavy calcium carbonate particles obtained by dry grinding, classified and sieved calcium carbonate particles, and the like are used. The calcium carbonate particles are dispersed in an aqueous medium.

The heavy calcium carbonate is wet-pulverized in the presence of the treating agent (A). Specifically, calcium carbonate /
The weight ratio with the aqueous medium (preferably water) is 70 / 30-3.
0/70, preferably 60/40 to 40/60, an aqueous medium is added to the calcium carbonate, and the cationic copolymer dispersant is added as a solid component to the calcium carbonate in an amount of 0.01 / 100 parts by weight of calcium carbonate. 10 to 10 parts by weight, preferably 0.1 to 5 parts by weight, is wet-pulverized by a conventional method.
Further, an aqueous medium prepared by previously dissolving the treating agent (A) in an amount in the above range may be prepared, and the aqueous medium may be mixed with calcium carbonate and wet-pulverized by an ordinary method. The wet pulverization may be a batch type or a continuous type, and it is preferable to use a mill using a pulverizing device such as a sand mill, an attritor, and a ball mill. By the wet pulverization in this way, the average particle size is more than 2 μm and 20 μm or less, preferably 2.
2-5 μm calcium carbonate particles are obtained.

Next, the wet pulverized product is dried. Before the drying, a classification step is provided to remove coarse powder such as 350 mesh on. Drying can be performed by a known method such as hot air drying or powder jet drying, but is preferably performed by medium fluidized drying. Fluid drying of a medium means that a slurry-like substance is supplied into a group of fluidized particles (fluidized bed) in a fluidized state by hot air (80 to 150 ° C.) in a drying tower, and the supplied slurry-like substance is actively fluidized. This is a method in which various substances are dried by being dispersed in a fluidized bed while adhering to the surface of the medium particles in a film form and receiving a drying action by hot air. Such media fluidized drying, for example,
It can be easily performed by using a media fluid dryer “Media Slurry Dryer” manufactured by Nara Machinery Co., Ltd. It is preferable to use the medium fluidized drying because the drying and the disintegration of the aggregated particles (removal of the primary particles) are simultaneously performed.

When the wet pulverized slurry obtained by this method is fluidized and dried in a medium, calcium carbonate having an extremely small amount of coarse powder can be obtained. However, it is also effective to pulverize and classify the particles by a desired method after the fluidized-drying of the medium. On the other hand, in the case where the wet pulverized product is dried by ordinary hot air drying instead of the medium fluidized drying, it is preferable that the obtained cake is further subjected to particle pulverization and classification by a desired method. The dry cake of the wet-ground product obtained by this method is easily crushed, and calcium carbonate fine particles can be easily obtained.
Therefore, it is not necessary to provide a step of pulverizing the dried cake. The calcium carbonate fine particles thus obtained are further treated with a treating agent (B) in an aqueous medium.

When the treating agent (A) is dissolved or dispersed in a solvent or mixed with an inorganic and / or organic fine powder in the form of a paste, the mixing temperature depends on the properties of the fine powder and the surface treating agent. As an example, the temperature is in the range of room temperature to 120 ° C, and the temperature when drying is required is in the range of 40 to 120 ° C, preferably 80 to 120 ° C. If necessary, drying under reduced pressure and use of a dry gas or hot air can also be used. The treatment with the treatment agent (B)
A method performed after the above-mentioned wet pulverization, a method in which the fine powder is dispersed in an aqueous solvent (preferably water), and then a treatment with the treatment agent (A) and then with the treatment agent (B). A method in which the fine powder subjected to the surface treatment is mixed and melt-kneaded with the thermoplastic resin and simultaneously added and treated. Among these, preferably, a method of adding (A) in a wet pulverizing step of fine particles and then treating with a treating agent (B), and treating the treating agent (A) with the fine particles dispersed in water. And then treating with a treating agent (B), and adding and treating the fine powder surface-treated with the treating agent (A) simultaneously with mixing or melt kneading with a thermoplastic resin. is there.

(Amount Ratio of Constituent Components) The preferred range of the amount ratio of the components constituting the porous resin film of the present invention is 30 to 90% by weight of the thermoplastic resin, 70 to 90% of the surface-treated inorganic and / or organic fine powder. 10% by weight. A more preferable range of the thermoplastic resin is 30 to 60% by weight, and further preferably 35 to 55% by weight. The content is 30% by weight or more from the viewpoint of increasing the strength of the film, and 90% by weight or less in order to further enhance the absorbability of an aqueous solvent or ink. The amount of the surface-treated organic and / or inorganic fine powder is, for example, 70 to 10% by weight. In the case of the inorganic fine powder, the amount is preferably 70 to 40% by weight, more preferably 65 to 45% by weight. Range. It is better to increase the amount of the fine powder in order to increase the number of pores, but for the purpose of setting the strength of the surface of the porous resin film to a good level, the amount is 70% by weight or less. In the case of organic fine powder, the specific gravity is often low, preferably 10 to 50% by weight, more preferably 15 to 40% by weight.

The amount of the treating agent (A) varies depending on the use of the porous resin film of the present invention, but is usually 0.01 to 10 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of inorganic and / or organic fine powder. It is in the range of 0.04 to 5 parts by weight, more preferably 0.07 to 2 parts by weight. 0.01 parts by weight or more is preferable from the viewpoint of increasing the absorbability of the aqueous solvent or the aqueous ink. If it exceeds 10 parts by weight, the effect of the surface treatment agent reaches a plateau. The amount of the treating agent (B) used depends on the use of the porous resin film of the present invention, but is usually 0.01 to 10 parts by weight, preferably 0.05 to 10 parts by weight, per 100 parts by weight of the inorganic or organic fine powder. 5 parts by weight, more preferably 0.
It is in the range of 5 to 4 parts by weight. 0.01 parts by weight or more is preferable from the viewpoint of increasing the absorbability of the aqueous solvent or the aqueous ink. If it exceeds 10 parts by weight, the effect of the surface treatment agent reaches a plateau.

(Optional components) When these fine powders are mixed and kneaded in a thermoplastic resin, a dispersing agent, an antioxidant, a compatibilizer, a flame retardant, an ultraviolet stabilizer, a coloring pigment, etc. are added as required. can do. When the porous resin film of the present invention is used as a durable material, it is preferable to add an antioxidant, an ultraviolet stabilizer and the like.

(Manufacturing method) As a method for mixing the constituents of the porous resin film of the present invention, various well-known methods can be applied, and there is no particular limitation. Selected as appropriate. Mixing in a state of being dissolved or dispersed in a solvent, roll kneading, and melt kneading may be mentioned, but the melt kneading method has good production efficiency. Inorganic or organic fine powder surface-treated with thermoplastic resin or treating agent (A) in the form of powder or pellets and, if necessary, treating agent (B) mixed with Henschel mixer, ribbon blender, super mixer, etc. After that, it is melt-kneaded with a uniaxial or biaxial kneader, extruded into a strand and cut and pelletized, or extruded into water from a strand die and cut with a rotary blade attached to the die tip Is mentioned. Various L / D (shaft length / shaft diameter) can be used for single-shaft or twin-shaft kneaders.
In addition, materials such as membran speed, specific energy, residence time, and temperature can be selected according to the properties of the components used.

The porous resin film and the recording medium of the present invention can be produced by combining various methods known to those skilled in the art. A porous resin film or a recording medium produced by any method is included in the scope of the present invention as long as a porous resin film satisfying the conditions described in the present invention is used. As a method for producing the porous resin film of the present invention, various known film production techniques and combinations thereof are possible. For example, a stretched film method utilizing void generation by stretching, a rolling method or a calendering method for generating voids during rolling, a foaming method using a blowing agent, a method using void-containing particles, a solvent extraction method, A method of dissolving and extracting a mixed component is exemplified. Of these, the stretched film method is preferred.

When performing stretching, it is not always necessary to stretch only the porous resin film of the present invention. For example,
If the recording medium in which the porous resin film of the present invention is formed on the base material layer is to be finally manufactured, the non-stretched porous resin film layer and the base material layer are laminated and then collected together. It may be stretched. If they are laminated and stretched in advance, they are simpler and less expensive than the case where they are separately stretched and laminated. Further, the control of the pores formed in the porous resin film of the present invention and the substrate layer becomes easier. In particular, when used as a recording medium, the porous resin film of the present invention is controlled so that more pores are formed than the substrate layer, and the porous resin film is a layer that can improve ink absorbency. It is preferable to make it function effectively.

For stretching, various known methods can be used. The stretching temperature is higher than the glass transition temperature of the thermoplastic resin to be used in the case of non-crystalline resin, and is higher than the glass transition temperature of the non-crystal part in the case of crystalline resin, but is lower than the melting point of the crystalline part. It can be performed within a suitable temperature range. Specifically, longitudinal stretching using the peripheral speed difference of the roll group, transverse stretching using a tenter oven, rolling, inflation stretching using a mandrel on a tubular film, simultaneous biaxial stretching using a combination of a tenter oven and a linear motor Stretching can be performed by such methods.

The stretching ratio is not particularly limited, and is appropriately determined in consideration of the purpose of use of the porous resin film of the present invention and the characteristics of the thermoplastic resin used. For example, when a propylene homopolymer or a copolymer thereof is used as the thermoplastic resin, when it is stretched in one direction, about 1.2 to 12
2 times, preferably 2 to 10 times, and in the case of biaxial stretching, the area ratio is 1.5 to 60 times, preferably 10 to 50 times. When other thermoplastic resins are used, when stretched in one direction, it is 1.2 to 10 times, preferably 2 to 7 times, and when biaxially stretched, the area ratio is 1.5 to 20 times.
Times, preferably 4 to 12 times. Further, a heat treatment at a high temperature can be performed if necessary. The stretching temperature is a temperature 2 to 60 ° C. lower than the melting point of the thermoplastic resin used, and the stretching speed is preferably 10 to 350 m / min.

Although the thickness of the porous resin film of the present invention is not particularly limited, it is, for example, 5 μm or more, preferably 25 μm or more, more preferably 30 μm or more from the viewpoint of further increasing the absorption of the aqueous solvent or the aqueous ink. . The upper limit is appropriately selected according to the required absorption amount of the aqueous liquid, but is, for example, 1000 μm or less, preferably
0 μm, more preferably 300 μm or less. The porous resin film of the present invention may be used as it is, or may be used after being laminated on another thermoplastic film, laminated paper, pulp paper, nonwoven fabric, cloth, or the like. Further, as another thermoplastic film to be laminated, for example,
It can be laminated on a transparent or opaque film such as a polyester film, a polyamide film and a polyolefin film. In particular, a recording medium can be formed by forming an appropriate functional layer as described in Examples described later. For example, a recording medium can be prepared by forming a porous resin film of the present invention as a surface layer on a base material layer made of a thermoplastic film. The recording medium having the porous resin film of the present invention as a surface layer is particularly useful as a recording medium for inkjet recording. The type of the substrate layer is not particularly limited, and examples thereof include a film containing a polypropylene resin and inorganic fine powder.

As described above, the recording medium formed by laminating the porous resin film of the present invention and another film can have, for example, an overall thickness of about 50 μm to 1 mm. The surface of the porous resin film or the laminate using the same may be subjected to a surface oxidation treatment, if necessary. In some cases, the surface oxidation treatment improves the hydrophilicity and absorptivity of the surface, or improves the coating properties of the ink fixing agent and the ink receiving layer and the adhesion to the substrate. Specific examples of the surface oxidation treatment include corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment,
The treatment method selected from the ozone treatment is preferably a corona treatment or a flame treatment, and more preferably a corona treatment.

In the case of corona treatment, the treatment amount is 600 to 1
2,000 J / m ² (10-200 W · min / m ² ), preferably 1200-9000 J / m ² (20-180 W
Min / m ² ). In order to sufficiently obtain the effect of the corona discharge treatment, the treatment effect is 600 J / m ² (10 W · min / m ² ) or more, and when it exceeds 12,000 J / m ² (200 W · min / m ² ), the effect of the treatment reaches a plateau. 12,000 J / m ²
(200 W · min / m ² ) or less is sufficient. For flame treatment, 8,000~200,000J / m ^2, preferably 20,000~100,000J / m ² is used. In order to obtain the effect of the frame processing clearly,
0 J / m ² or more, and if it exceeds 200,000 J / m ² , the effect of the treatment reaches a plateau, so that 200,000 J / m ²
The following is sufficient.

As a preferred embodiment of the porous resin film of the present invention, its liquid absorption volume is 0.5 ml / m ² or more, preferably 3 to 2600 ml / m ² , more preferably 5 to 100 ml / m ² . Range. 0.5ml
If it is less than / m ² , the absorption of the aqueous ink and the aqueous paste is insufficient. In addition, since the thickness of the porous resin film must be considered in order to increase the absorption amount, the upper limit is appropriately selected depending on the application. The liquid absorption volume of the porous resin film of the present invention is “Japan TAPPI No. 51-8.
7 "(Paper and Pulp Technology Association, Paper and Pulp Test Method No. 51)
-87, Bristow method). In the present invention, the measured value whose absorption time is within 2 seconds is defined as the liquid absorption volume. The measurement solvent is measured using a solvent obtained by adding a coloring dye with a mixed solvent of 70% by weight of water and 30% by weight of ethylene glycol as 100% by weight. As a coloring dye, malachite green or the like is used, and the amount is about 2 parts by weight, in addition to 100 parts by weight of the mixed solvent, as long as the surface tension of the solvent used for measurement does not significantly change. The type and amount of the coloring dye used are not particularly limited.

Examples of the measuring device include a liquid absorption tester manufactured by Kumagai Riki Kogyo Co., Ltd. In addition, the larger the liquid absorption volume in a shorter absorption time, the smaller the amount of protrusion from the edge of the paper when an aqueous paste or the like is used. In the present invention, the liquid absorption volume within 40 milliseconds is 0.8 ml / m ² or more, more preferably 1 to 500 m
1 / m ² . Furthermore, the larger the liquid absorption rate measured in connection with the above-mentioned measurement of the liquid absorption volume, the better the tendency is to give better results to absorption and drying of the supercolored portion. The absorption rate between 20 milliseconds and 400 milliseconds is generally 0.02 ml / {m ² · (ms) ^1/2 }
It is the above range, more preferably 0.1 to 100 m
1 / {m ² · (ms) ^1/2 } or more.

The surface contact angle of the porous resin film of the present invention with water is 110 ° or less, preferably 0-100.
°, more preferably in the range of 0 to 90 °. 110 °
In the range exceeding the range, there are cases where the liquid permeation such as the paste using the aqueous ink or the aqueous medium is not sufficient. Also, there is a case where the contact angle has an appropriate range from the viewpoint of balancing the spread of the water-based ink droplet in the direction parallel to the film paper surface and the penetration in the film thickness direction. Selected as appropriate. In addition, the water contact angle of the film surface in the present invention is measured using a commercially available contact angle meter, and one minute after dropping pure water onto the film surface, using the same contact angle meter. The measurement is performed ten times for one sample, and the average value of the contact angles measured by replacing the film with an unmeasured film whose surface is not wet with pure water at each measurement is defined as a water contact angle. An example of a commercially available contact angle meter that can be used for the contact angle measurement of the present invention is Model CA-D manufactured by Kyowa Interface Chemical Co., Ltd.

Further, as the “difference between the maximum value and the minimum value” in the ten contact angle measurements is smaller, the absorption of the ink or the liquid using the aqueous medium tends to be more uniform,
It gives better print quality as a print medium, but as an example, the difference between the maximum value and the minimum value is within 40 °, preferably within 30 °, more preferably within 20 °.
The porous resin film of the present invention has fine pores on the surface, and absorbs the aqueous ink or aqueous liquid coming into contact with the surface from the pores. The number and shape of the pores on the surface of the porous resin film and the presence of at least a part of the inorganic or organic fine powder in the surface pores can be known by observation with an electron microscope.

Any part of the porous resin film sample
Cut and affix it to the observation sample table,
Deposits gold-palladium, etc., and uses an electron microscope, for example,
Scanning electron microscope S-2400 manufactured by Ritsu Seisakusho Co., Ltd.
Surface pore shape at any magnification that is easy to use and observe
The number of holes can be observed, the size of the holes and the shape of the holes
You can know. Unit surface of porous resin film surface
The number of holes per product is 1 × 10⁶Pieces / m^TwoAbove range
Is it a point of view to make absorption of aqueous liquid faster?
And preferably 1 × 10⁷Pieces / m^TwoMore preferably,
1 × 10⁸Pieces / m^TwoThat is all. In addition, more surface strength
From the viewpoint of obtaining a good level, preferably 1 × 10
^FifteenPieces / m ^TwoBelow, more preferably 1 × 10¹²Pieces / m^TwoLess than
The range is below.

The shape of the pores near the surface of the porous resin film is various such as circular and elliptical. The maximum diameter (L) of each pore and the maximum diameter (M )
[(L + M) / 2] is defined as the average diameter of each pore. The measurement is repeated for at least 15 surface pores, and the average value is defined as the average diameter of the pores on the surface of the porous resin film of the present invention. The measurement is repeated for at least 20 surface vacancies, and the average value is defined as the average diameter. From the viewpoint of obtaining a better level of liquid absorbency, the average diameter is at least 0.01 μm, more preferably at least 0.1 μm, and still more preferably at least 1 μm. In order to improve the surface strength of the porous resin film, the average diameter is 50 μm or less, preferably 30 μm or less, and more preferably 20 μm or less.

At least a part, preferably about 30% or more, of the pores on the surface or in the vicinity thereof has an inorganic or organic fine powder inside or around the pores. Preferably, the larger the number, the more the absorption capacity tends to be improved. The porous resin film of the present invention has a porous structure having fine pores inside,
The porosity is 10% or more, preferably 20 to 75%, and more preferably 30 to 65%, in order to improve the absorption drying property of the aqueous ink. When the porosity is 75% or less, the material strength of the film is at a good level.

It is preferable that at least some of the pores in the inside have inorganic or organic fine powder inside or around the pores. Absorption capacity tends to improve. The presence of pores inside and the existence of at least a part of the inorganic or organic fine powder in the internal pores can be confirmed by observing a cross section with an electron microscope. Note that the porosity in the present specification indicates the porosity represented by the following formula or the area ratio (%) occupied by vacancies in a region obtained by observing a cross-sectional electron micrograph. Porosity (%) = 100 (ρ ₀ −ρ) / ρ ₀ (where, ρ ₀ : density of non-porous portion of porous resin film, ρ: density of porous resin film)

More specifically, after the porous resin film is embedded in the epoxy resin and solidified, a cut surface parallel to, for example, the thickness direction of the film and perpendicular to the surface direction is formed using a microtome. After metallizing the cut surface, it can be observed at an arbitrary magnification that is easy to observe with a scanning electron microscope, for example, from 500 to 2000. As an example, an observed area is photographed, a hole is traced on a tracing film, and a solid figure is displayed on an image analysis device (manufactured by Nireco Corporation: Model Luzex II).
The image processing may be performed in D), and the area ratio of the holes may be determined to be the porosity. Further, in the case of a laminate having the porous resin film of the present invention on the surface, the thickness and basis weight (g / m ² ) of the laminate and the portion where the porous resin film layer of the present invention is removed therefrom The thickness and basis weight of the porous resin film layer are calculated, the density (ρ) is calculated from the thickness and the density (ρ ₀ ) of the non-void portion is further calculated from the composition of the constituent components, and the density (ρ ₀ ) is calculated by the above equation. it can.

Further, the shape and size of the internal pores may be adjusted at any magnification, for example, 50, which is easy to observe with a scanning electron microscope.
It can be observed at a magnification of 0 to 2000 times. The dimensions of the internal holes are obtained by measuring the dimensions in the plane direction and the thickness direction of at least 10 internal holes and averaging the measured values. The average size in the plane direction of the pores of the porous resin film is 0.1 to 1000 μm, preferably 1 to 1000 μm.
The range is 500 μm. From the viewpoint of improving the mechanical strength of the porous resin film to a better level, the maximum dimension of the pores in the surface direction of the film is preferably 1000 μm or less.
From the viewpoint of obtaining a higher level of water-based liquid absorbability, the maximum dimension of the film in the surface direction is preferably 0.1 μm or more. The average size in the thickness direction of the pores of the porous resin film is usually 0.01 to 50 μm, preferably 0.1 to 50 μm.
It is in the range of 1 to 10 μm. To improve the absorption of aqueous liquids,
The larger the dimension in the thickness direction, the better, but from the viewpoint of obtaining a suitable mechanical strength of the film, the upper limit can be selected according to the application.

When the porous resin film of the present invention is used as a recording medium, a colorant fixing layer for fixing a dye and a pigment colorant and an ink receiving layer can be formed on the surface thereof. Compared to the case of coating on a resin film with low absorbency, by combining with the porous resin film of the present invention having good water-based solvent absorbability, it reduces bleeding, improves absorbency, and improves the colorant fixing layer and the ink receiving layer. It is also possible to reduce the thickness. The colorant fixing layer has a function of rounding the dot shape of the ink, obtaining a clearer image, and preventing the colorant flow due to water or moisture. Therefore, the coloring agent fixing layer is particularly useful when the porous resin film of the present invention is used as an ink jet recording medium.

The colorant fixing layer and the ink receiving layer can be formed by coating or laminating. In order to improve the fixability of the colorant, it is preferable to use a hydrophilic resin having a cationic property and a fine powder. For example, as the cationic copolymer, those containing a cationic group such as an amino group, a modified product thereof, or a quaternary ammonium base in the main chain or side chain of the polymer can be used. As an ink receiving layer for inkjet, a porous ink receiving layer mainly composed of a pigment and an aqueous binder is used in a field requiring quick drying of the ink, and an aqueous binder is used when a high gloss is required. A swellable ink receiving layer as a main component can be provided. As pigments, synthetic silica, colloidal silica, alumina hydrosol, aluminum hydroxide,
Examples include talc, calcium carbonate, clay, plastic pigment, barium sulfate, titanium dioxide and the like. Among them, porous synthetic silica and alumina hydrosol are preferable.

Examples of the aqueous binder include a polyurethane resin, a polyester resin, a vinyl acetate resin, an acrylate resin, a styrene-acrylate copolymer, a vinyl acetate-acrylate copolymer, and a styrene-butadiene copolymer. Aqueous emulsions such as polymers, methyl methacrylate-butadiene copolymer, etc., polyvinyl alcohol, ethylene / vinyl alcohol copolymer containing silanol groups, polyvinyl acetal, polyvinyl pyrrolidone, methyl ethyl cellulose, sodium polyacrylate, various starch, Water-soluble polymers such as gelatin. Among them, when the pigment is porous synthetic silica, alumina hydrosol, polyvinyl alcohol,
An ethylene / vinyl alcohol copolymer containing a silanol group is preferred.

When the ink receiving layer used in the present invention is required to have an ink fixing property, an ink setting agent is blended.
Examples of the ink setting agent include cationic polymers such as a tertiary ammonium salt of polyethyleneimine, an acrylic copolymer containing a quaternary ammonium group as a copolymerization component, and an epichlorohydrin adduct of polyamine polyamide. Further, the coloring material fixing layer and the ink receiving layer used in the present invention may contain, as additives, pigment dispersants, thickeners, defoamers, fluorescent brighteners, ultraviolet absorbers, antioxidants, preservatives, and water resistance. An agent and the like can be appropriately compounded. In the case of a porous ink receiving layer, the ratio of pigment / water-based binder / ink setting agent is 50 to 90% by weight / 10 to 40% by weight / 0 to 20% by weight.
Is preferred. In the case of the swellable ink receiving layer, the ratio of the aqueous binder / ink setting agent is preferably 60 to 100% by weight / 0 to 40% by weight.

As the coating method of the ink receiving layer, general coating methods such as a blade method, a rod method, a wire bar method, a slide hopper method, a curtain method, an air knife method, a roll method, and a size press method are used. Can be The dry coating amount of the ink receiving layer varies depending on the required ink absorptivity, gloss, support absorptivity and the like, but is usually 0.05 to 100 g / m ² , preferably 0.1 to 5 g / m ² .
It is preferably 0 g / m ² . In the present invention, the ink receiving layer may be either a single layer or a multilayer of two or more layers. In the case of a multilayer, each layer can have a different composition or the same composition. When forming multiple layers,
Two or more layers may be applied at a time or one layer at a time.

The porous resin film or laminate of the present invention can be subjected to printing other than ink jet printing depending on the purpose of use. The type and method of printing are not particularly limited. For example, printing can be performed by using known printing means such as gravure printing using an ink in which a pigment is dispersed in a known vehicle, aqueous flexo, and silk screen. In addition, printing can be performed by metal deposition, gloss printing, mat printing, or the like. Images to be printed are animals, landscapes, grids,
It can be appropriately selected from natural patterns such as polka dots and abstract patterns. In addition to printing applications, it can also be used for applications that need to absorb aqueous liquids. For example, pressure-sensitive adhesive labels using water-based pressure-sensitive adhesives, label paper for containers such as bottles and cans, water-absorbing films, wallpapers, surface decorative paper for plywood and plasterboard, water-drop prevention films, food drip-proof wrapping paper, coasters , Craft paper, origami, water retention sheet,
It can also be used as a soil drying prevention sheet, a concrete drying auxiliary material, a desiccant, a dehumidifier, and the like.

[0085]

The present invention will be more specifically described below with reference to examples, comparative examples and experimental examples. The materials, usage amounts, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the examples described below. A porous resin film of the present invention, a recording medium using the same, and a recording medium using a comparative resin film were produced according to the following procedures.

(Experimental Example 1) Heavy carbon dioxide was used as the fine powder.
Lucium (average particle diameter 3 μm, specific surface area 1.8 m ^Two/
g, absorption measured according to JIS-K5101-1991.
Oil amount 31ml / 100g, abbreviation: charcoal 1) 40 weight
% And 60% by weight of water are sufficiently stirred and mixed to form a slurry.
Sodium recarboxylate (trade name: Dispersant 5)
040, manufactured by San Nopco Co., Ltd., abbreviation: A1)
0.2 parts by weight per 100 parts by weight of calcium acid
And then mixed with Anstex SAS (main component is carbon
Sodium alkane sulfonate of number 14 and C 16
A mixture of sodium alkane sulfonates, Toho Chemical Industry
(Trade name, abbreviation: B1) 2% aqueous solution, 50 layers
Parts (solid content per 100 parts by weight of heavy calcium carbonate)
2.5 parts by weight) and the resulting mixture was stirred.
Made by Nara Machinery Co., Ltd., MSD-200 medium fluid drying
Drying with a dryer to obtain surface-treated heavy calcium carbonate
Was. The symbol of this is F1. In addition, the actual
The particle size of the calcium carbonate powder used in the examples
-Diffraction Particle Measurement System "Microtrack" (Stock
50% particle size as measured by Nikkiso Co., Ltd.
It is.

(Experimental Example 2) Heavy calcium carbonate (average particle diameter 3 μm, specific surface area 1.8 m ² / g, JIS-K51
Oil absorption measured by 01-1991 is 31 ml / 1
00 g, abbreviation: charcoal 1) 40% by weight of water and 60% by weight of water were sufficiently stirred and mixed to form a slurry. Quality calcium carbonate 100
Add 0.2 parts by weight per part by weight, mix and stir, and then stir the slurry to make MSD manufactured by Nara Machinery Co., Ltd.
-200 medium fluidized-bed dryer was used to obtain surface-treated heavy calcium carbonate. The symbol of this is F2.

(Experimental Example 3) Heavy calcium carbonate (average particle diameter 3 μm, specific surface area 1.8 m ² / g, JIS-K51
Oil absorption measured by 01-1991 is 31 ml / 1
100 g, abbreviation: charcoal 1) 100 parts by weight were heated and stirred at 80 to 100 ° C. with a super mixer, and a surface treating agent (manufactured by Tokyo Chemical Industry Co., Ltd., 50% of reagent grade sodium dodecane sulfonate and Tokyo) Manufactured by Kasei Kogyo Co., Ltd.
Reagent grade sodium hexadecanesulfonate 50
% Mixture), and further heated and stirred to obtain surface-treated calcium carbonate. The temperature in the supermixer was about 100C to 120C. The symbol of this is F3.

(Experimental Example 4) Calcium carbonate surface-treated was obtained in the same manner as in Experimental Example 3 except that lauryltrimethylammonium methosulfate was used as the surface treating agent (abbreviation: F4). (Experimental Example 5) Calcium carbonate surface-treated by the same operation as in Experimental Example 3 except that the surface treating agent was changed to 3-lauroylaminopropyldimethyl (2-hydroxyethyl) nitrate (abbreviation: F5). . (Experimental example 6) Surface treatment was carried out in the same manner as in Experimental example 1 except that the surface treatment agent was changed to a mixture of dilauryl di (diethyleneoxy) ammonium chloride and dilauryl (2-hydroxyethyl) (trioxyethyleneoxy) chloride. Calcium carbonate was obtained (abbreviation: F6).

[0090]

Example 1 <Preparation of base layer and longitudinal stretching> Melt flow rate (MFR: 230 ° C., 2.16 kg load) was 1 g /
75 minutes by weight of polypropylene for 10 minutes and melt flow rate (MFR: 190 ° C., 2.16 kg load) of 8 g / 1
A composition [I] obtained by mixing 20% by weight of calcium carbonate having an average particle diameter of 3 μm with a mixture of 5% by weight of high-density polyethylene of 0 minutes is kneaded with an extruder set at a temperature of 250 ° C. And cut into pellets. This composition [A] was extruded into a sheet from a T-die connected to an extruder set at 250 ° C., and was cooled by a cooling device to obtain a non-stretched sheet. Then
After heating this unstretched sheet at 145 ° C., it was stretched 4.5 times in the machine direction to obtain a stretched sheet. In the melt kneading of the resin component or the mixture of the resin component and the fine powder in each Example, the total weight of the resin component and the fine powder was set to 100 parts by weight, and in addition, BHT as an antioxidant was added.
(4-methyl-2,6-di-t-butylphenol)
0.2 parts by weight and 0.1 parts by weight of Irganox 1010 (phenolic antioxidant, trade name, manufactured by Ciba Geigy) were added.

<Formation of Surface Porous Resin Film> Separately, polypropylene 4 having an MFR of 20 g / 10 min.
0% by weight (abbreviation: PP1) and 60% by weight of the surface-treated calcium carbonate (abbreviation: F1) described in Experimental Example 1 are sufficiently mixed in a powder state, and melt-kneaded by a twin-screw kneader set at 240 ° C. The mixture was extruded and cut into strands to obtain pellets (composition [b]). This composition was added to 230
The sheet was extruded from a T-die connected to an extruder set at a temperature of ° C. (temperature a). The obtained sheet was laminated on both sides of the 4.5-fold stretched sheet prepared by the above-mentioned operation,
After cooling to (temperature b), it was heated to 154 ° C. (temperature c) and stretched 8.5 times in the transverse direction with a tenter. afterwards,
Anneal at 155 ° C. (temperature d), cool to 55 ° C. (temperature e), slit the ears, and make 3 layers (absorption layer [b] on the front side / base layer [b] / absorption layer on the back side) [B]: 49 μm / 44 μm / 32 μm in thickness) 125 μm in total thickness of the structure
m having a porous resin film.

Hereinafter, the laminates of Examples and Comparative Examples were evaluated for the absorption layer on the front side. This was evaluated in the following manner. <Evaluation> (1) Liquid Absorption Volume The liquid absorption volume of the above porous resin film at 2 seconds is “Japan TAPPI No. 51
-87 "(Paper and Pulp Technology Association, Paper and Pulp Test Method No.
51-87, Bristow method), using a liquid absorption tester manufactured by Kumagai Riki Kogyo Co., Ltd. As a measurement solvent, 70% by weight of water and 30% by weight of ethylene glycol were mixed, and 100 parts by weight of the mixed solvent was used as a coloring dye.
It is obtained by dissolving 2 parts by weight of malachite green. (2) Average contact angle of porous resin film to water, difference between maximum value and minimum value The contact angle of the surface of the porous resin film is determined by contact angle meter (1 minute after pure water is dropped on the film surface). The measurement was performed using Kyowa Interface Chemical Co., Ltd .: Model CA-D). The measurement was performed 10 times (each time, the film was replaced with an unmeasured film whose surface was not wetted with pure water), and the average value of the contact angles measured 10 times and the difference between the maximum value and the minimum value were determined. Was.

(3) Confirmation of Existence of Surface Vacancies and Measurement of Number of Surface Vacancies and Surface Vacancy A part of the porous resin film was cut out, and it was confirmed that pores existed on the surface and in the cross section. Cut an arbitrary part from the porous resin film sample, paste it on the observation sample table, deposit gold or gold-palladium on the observation surface,
Scanning electron microscope S- manufactured by Hitachi, Ltd.
Using 2400, the presence of vacancies on the surface by magnifying 500 times, and the presence of inorganic fine powder in the majority of vacancies of at least about 50% or more of the total number of vacancies or at the ends of vacancies Confirmed that. An electron microscope image was output or photographed on thermal paper, and the number of holes on the surface was measured. As a result, it was about 2.4 × 10 ⁹ / m ² . Then, the above 10
As a result of averaging the measured values of five holes, the long diameter was 15.2 μm.
m, the minor axis was 4.8 μm, and the average diameter was 10 μm. In addition, when each two holes were connected to the left and right or up and down of the fine powder, the two holes were measured as one connected hole assuming that the holes were formed around the fine powder.

(4) Confirmation of existence of internal pores and measurement of internal porosity After embedding the above-mentioned porous resin film with epoxy resin and solidifying it, using a microtome, the thickness direction of the film was measured. After making a cut surface parallel and perpendicular to the surface direction, and after metallizing this cut surface with gold-palladium,
Using a scanning electron microscope S-2400 manufactured by Hitachi, Ltd., the sample was observed at a magnification of 1000 times, and it was confirmed that internal voids existed and that fine powder was present in at least a part of the internal voids. confirmed. The total thickness and basis weight (g / m ² ) were measured, then the surface absorbing layer was peeled off in a certain area, and the basis weight and thickness of the remaining film were measured.
The thickness and basis weight (g / m ² ) of the porous resin film layer were determined, and the basis weight was divided by the thickness to calculate the density (ρ) of the absorbing layer. Next, the composition [b] was heated at 230 ° C. to a thickness of 1
mm, and the density (ρ ₀ ) was measured, and the porosity was calculated by the following equation. Porosity (%) = 100 (ρ ₀ −ρ) / ρ ₀ (where, ρ ₀ : density of non-porous portion of porous resin film, ρ: density of porous resin film).

(5) Color chart for ink absorption evaluation
0% printing) and printed on a porous resin film as a surface layer of each recording medium by an inkjet printer (Model JP2115, manufactured by Graphtec, Inc.) using a pigment ink (yellow, magenta, cyan, black). . After that, the filter paper is crimped to the printing part at regular intervals,
It was observed whether the ink returned to the filter paper. The time when the ink did not return to the filter paper was recorded, and the ink absorbency was evaluated according to the following criteria. 6: The time during which the ink does not return to the filter paper is within 30 seconds. 5: The time during which the ink does not return to the filter paper is more than 30 seconds and within 1 minute. 4: The time when the ink does not return to the filter paper exceeds 1 minute,
Within 2 minutes. 3: The time when the ink does not return to the filter paper exceeds 2 minutes,
Within 3 minutes. 2: The time when the ink does not return to the filter paper exceeds 3 minutes,
Within 4 minutes. 1: The time when the ink does not return to the filter paper exceeds 4 minutes,
Within 5 minutes. 0: Even after more than 5 minutes, the ink returned to the filter paper and was not absorbed.

(Evaluation of density unevenness) Density unevenness after absorbing the ink was visually observed and evaluated according to the following criteria. 4: There is no density unevenness at all. 3: There is little density unevenness. 2: There is density unevenness. 1: Density unevenness is noticeable. (Evaluation of bleeding) The bleeding after absorbing the ink was visually observed and evaluated according to the following criteria. 4: There is no blur and the image is clear. 3: There is little bleeding and there is almost no hindrance to image identification. 2: There is bleeding, and there is a problem in image identification. 1: The bleeding is remarkable, and it cannot be used. (Evaluation of Roughness of Paper After Printing) After printing, the paper was left in a room for 1 hour, and it was visually observed whether or not the paper had unevenness (unevenness), and evaluated according to the following criteria. 3: There is no unevenness, the paper surface is flat, and there is almost no change from before printing. 2: There is little unevenness. 1: Unevenness is noticeable. Table 1 shows the results of these tests and evaluations.

[0097]

Comparative Example 1 In the preparation of a pellet-shaped composition [b], the heavy calcium carbonate (average particle diameter 3 μm) used in Experimental Example 1 was used in place of the surface-treated calcium carbonate F1.
m, specific surface area by BET method is 1.8 m ² / g, JIS
The oil absorption measured by K-5101-1991 is 3
1 ml / 100 g of calcium carbonate) was used without any surface treatment.
A laminated film having a porous resin film on the surface was prepared and evaluated. Table 1 shows the results of these tests and evaluations.

[0098]

Comparative Example 2 In the preparation of the pellet-shaped composition [b], the heavy calcium carbonate (average particle diameter 3 μm) used in Experimental Example 1 was used instead of the surface-treated calcium carbonate F1.
m, specific surface area by BET method is 1.8 m ² / g, JIS
The oil absorption measured by K-5101-1991 is 3
1 ml / 100 g of calcium carbonate), and stearic acid as a surface treatment agent.
A laminated film having a porous resin film on its surface was prepared and evaluated in the same manner as in Example 1 except that 4 parts by weight was added to 00 parts by weight. Table 1 shows the results of these tests and evaluations.

[0099]

Example 2 In the preparation of the composition [b] in the form of pellets, the surface-treated heavy calcium carbonate F1 was used instead of the heavy calcium carbonate F1.
2 and dodecyldimethyl (3-sulfopropyl) ammonium inner salt (manufactured by Aldrich, reagent grade, abbreviation: B) as a second surface treatment agent
2) to 5 parts by weight of calcium carbonate before treatment
Except for adding parts by weight, the same operation as in Example 1 was carried out.
A laminated film having a porous resin film on the surface was prepared and evaluated. Table 1 shows the results of these tests and evaluations.

[0100]

Example 3 In the preparation of the composition [b] in the form of pellets, the surface-treated heavy calcium carbonate F1 was used instead of F1.
2 and a mixture of lauryl dimethyl ethyl ammonium ethosulfate, cetyl dimethyl ethyl ammonium ethosulfate, and stearyl dimethyl ethyl ammonium ethosulfate (abbreviation: B3) as a second-stage surface treatment agent.
A laminated film having a porous resin film on the surface was prepared and evaluated in the same manner as in Example 1 except that 5 parts by weight was added to 0 parts by weight. Table 1 shows the results of these tests and evaluations.

[0101]

EXAMPLE 4 In the preparation of the composition [b] in the form of pellets, F3 was used in place of F1, and B3 was used as a second-stage surface treatment agent in an amount of 5 parts by weight based on 100 parts by weight of calcium carbonate before the treatment. A laminated film having a porous resin film on the surface was prepared and evaluated in the same manner as in Example 1 except that the addition was partially performed. Table 1 shows the results of these tests and evaluations.

[0102]

Example 5 In the preparation of a pellet composition [b], F4 was used in place of F1, and B1 was added as a second surface treatment agent in an amount of 4 parts by weight based on 100 parts by weight of calcium carbonate before the treatment. Other than the above, a laminated film having a porous resin film on the surface was prepared and evaluated in the same manner as in Example 1. Table 1 shows the results of these tests and evaluations.

[0103]

Example 6 In the preparation of the composition [b] in the form of pellets, F5 was used in place of F1, and lauryltrimethylammonium methosulfate (abbreviation: B4) was used as a second-stage surface treatment agent. Calcium 100
A laminated film having a porous resin film on the surface was prepared and evaluated in the same manner as in Example 1 except that 4 parts by weight was added to the parts by weight. Table 1 shows the results of these tests and evaluations.

[0104]

Example 7 MFR: 2 g / 10 min, melting point: 164 ° C.
(DSC peak temperature), a mixture of 70% by weight of polypropylene having a crystallinity of 87% and 8% by weight of high-density polyethylene mixed with 22% by weight of the surface-treated calcium carbonate B3 obtained in Experimental Example 3 above. Is kneaded with a twin-screw kneader set at 240 ° C. and extruded into strands,
It was cut into pellets. This is used as a composition [A] to be used for the next lamination. Apart from this, MF
R is 20 g / 10 min, 45% by weight of polypropylene and the surface-treated calcium carbonate F obtained in Experimental Example 6 above.
6 and 55 parts by weight of sodium benzenesulfonate (abbreviation: B5) were mixed with 100 parts by weight of calcium carbonate before treatment, and kneaded with a biaxial kneader set at 240 ° C. It was extruded into a strand and cut into pellets. This is used as a composition [b] to be used for the next lamination. The composition [a] and the composition [b] are melt-kneaded at 230 ° C in separate extruders, and the composition [a] is placed in a die such that the composition [b] is on both sides of the center layer. And co-extruded with a cooling device.
It cooled at ℃ and obtained the unstretched sheet of a three-layer structure.

Next, the sheet was heated to 135 ° C., stretched 5 times in the machine direction, and then cooled to 55 ° C. to obtain a uniaxially stretched laminated film having a three-layer structure having a porous resin film on the surface. Each layer ([b] / [a] / [b]) of the three-layer stretched film has a thickness of 48 μm / 70.
The opacity was 93% at μm / 20 μm. Further, the surface of the laminated film was subjected to corona treatment at a treatment density of 3000 J / m ² . The same evaluation as in Example 1 was performed for the surface layer having a thickness of 48 μm of the laminated film. Table 1 summarizes the above evaluation results.

[0106]

[Table 1]

[0107]

Embodiments 8 and 9 Each of the laminates having the porous resin films shown in Embodiments 1 and 5 on the surface has 4
Corona treatment was performed at a treatment density of 200 J / m ² (70 watts / min / m ² ), and the same evaluation as in Example 1 was performed. Table 2 shows the evaluation results.

[0108]

Example 10 The porous resin film produced in Example 1 was subjected to corona treatment at a processing density of 4200 J / m ² (70 watts / min / m ² ). This was used as a support (designated on one side) and coated with a coating liquid for an ink receiving layer having the following composition so that the solid content became 5 g / m ² , dried, and then smoothed with a super calender to perform inkjet printing. Recording paper was obtained. Coating composition: 100 parts by weight of synthetic silica powder (Mizukasil P-78D, Mizusawa Chemical Industry Co., Ltd.) 30 parts by weight of polyvinyl alcohol (Kuraray Co., Ltd., PVA-117) 30 parts by weight of polyamine polyamide epichlorohydrin adduct (Nippon PMC Co., Ltd. WS-) 570) 10 parts by weight Sodium polyacrylate (Wako Pure Chemical Industries, Ltd. reagent) 5 parts by weight Water 1600 parts by weight Evaluation was performed in the same manner as in Example 1. Table 2 shows the results
Shown in

[0109]

Example 11 A porous resin film obtained by subjecting the porous resin film of Example 1 to the same corona treatment as in Example 10 was used as a support (designated on one side). Was applied so as to be 5 g / m ² and dried to obtain an ink jet recording paper. Coating liquid composition: Alumina sol (Nissan Chemical Industries, Ltd. Alumina Sol 100, solid content 10%) 100 parts by weight Polyvinyl alcohol (Kuraray Co., Ltd. PVA-117) 10 parts by weight Water 100 parts by weight The evaluation results are shown in Table 2.

[0110]

Example 12 A porous resin film obtained by performing the same corona treatment as in Example 10 on the porous resin film of Example 1 was used as a support.
An ink receiving layer coating liquid having the following composition (designated on one side) was applied thereon so that the solid content became 5 g / m ² , and dried to obtain an ink jet recording paper. Coating liquid composition: Urethane binder (Dainippon Ink & Chemicals, Inc., SF coating agent 8310, solid content 13%) 100 parts by weight Polyamidine polymer (Hymo Co., Ltd., Himax SC700L, solid content 30%) 2 weight parts Table 2 shows the evaluation results.

Comparative Example 3 Commercially available pulp paper-based inkjet paper (Epson Sperfine paper MJA4SP1)
And the same evaluation as in Example 1 was performed. Table 2 shows the results
Shown in

[0111]

[Table 2]

As is evident from Tables 1 and 2, the porous resin films of the present invention (Examples 1 to 7) showed little density unevenness even when the ink ejection amount was large, and showed good absorption of ink and aqueous liquid. Is very good. On the other hand, a film whose liquid absorption is out of the range of the present invention (Comparative Examples 1 and 2)
Are inferior in ink absorbency. Further, as is apparent from Examples 8 and 9, the porous resin film whose surface has been subjected to oxidation treatment has good ink absorption, furthermore, has less density unevenness in the printed portion, and the effect of the present invention is clear. Further, as is apparent from Examples 10 to 12, when the ink receiving layer was provided, the ink absorption was good, the bleeding was good, and the effect of the present invention was obvious. Furthermore, from the comparison between each example and comparative example 3, the porous resin film of the present invention has no unevenness on the paper surface after printing, and the effect of the present invention is clear.

[0113]

As described above, the porous resin film of the present invention has extremely good water-based solvent and ink absorbency. Further, the recording medium of the present invention using the porous resin film can form a fine image without density unevenness even when the ink ejection amount is large. Therefore, the porous resin film and the recording medium of the present invention can be suitably provided for a wide range of printing applications such as an inkjet recording medium, particularly for recording applications using aqueous inks, and for applications using aqueous solvents.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiichiro Iida 23rd Towada, Kamisu-cho, Kashima-gun, Ibaraki Pref. AA66 AB05 AC26 AE01 AF00 AF03 AG01 CA02 CA03 CD15 CE02 CE46 CE84 DA03 4F100 AA08H AK01A AK01C AK03A AK03C AK05 AK07 AL05 AT00B BA02 BA03 BA06 BA07 BA10A BA10C CA13 CA30 DE01A DE01C DJJE EBJE10A DJ06E DJB10E DJA DJ06C DJA YY00A YY00C

Claims (18)

[Claims] 1. A thermoplastic resin comprising 30 to 80% by weight, a surface treating agent (A), and 70 to 20% by weight of an inorganic and / or organic fine powder surface-treated with the surface treating agent (B). A porous resin film characterized by the following. 2. “Japan TAPPI No. 51
-87 "is 0.5 ml
The porous resin film according to claim 1, wherein the thickness is in the range of / m ² or more. 3. The porous resin film according to claim 1, wherein an average contact angle with water is 110 ° or less. 4. The porous resin film according to claim 1, having pores on the surface and inside. 5. The porosity is 10% or more.
The porous resin film according to any one of the above. 6. The porous resin film according to claim 1, wherein pores are present on the surface at 1 × 10 ⁶ / m ² or more. 7. An average diameter of pores on the surface is 0.01 to 50.
The porous resin film according to any one of claims 1 to 6, wherein the thickness is in a range of µm. 8. The method according to claim 4, wherein at least a part of the surface and / or the internal vacancy has an inorganic or organic fine powder present inside or around the vacancy. The porous resin film according to the above. 9. The porous resin film according to claim 1, wherein the thermoplastic resin is a polyolefin resin. 10. The porous resin film according to claim 1, wherein the average particle diameter of the inorganic and / or organic fine powder is in the range of 0.01 to 20 μm. 11. The porous resin film according to claim 1, wherein the inorganic and / or organic fine powder has an average particle size of 2 to 10 μm or less. 12. An amount of the surface treating agent (A) of 0.01 to 10 parts by weight and an amount of the surface treating agent (B) of 0.01 to 10 parts by weight based on 100 parts by weight of the inorganic and / or organic fine powder. The porous resin film according to any one of claims 1 to 11, which is in a range. 13. The porous resin film according to claim 1, which is stretched. 14. The porous resin film according to claim 1, wherein the surface is subjected to an oxidation treatment. 15. A laminate having the porous resin film layer according to claim 1 on at least one surface of a base material layer. 16. A recording medium using the porous resin film or the laminate according to claim 1. 17. An ink jet recording medium using the porous resin film or the laminate according to claim 1. 18. A fixing agent for a colorant on at least one of the surfaces of the porous resin film according to claim 1 or at least one of the surfaces of the porous resin film of the laminate that is not in contact with the base material layer. An ink jet recording medium comprising a layer.