JP2001088263A - Laminated aliphatic polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated aliphatic polyester film which has antibacterial properties and antifungal properties and can control a decomposition rate in the nature. SOLUTION: The laminated aliphatic polyester film has a base of an aliphatic polyester film which has a primary repeating unit expressed by general formula -O-CHR-CO-(R is hydrogen or a 1-3C alkyl group). An antibacterial resin layer containing an antibacterial resin composition is set to an outermost layer of at least one face of the base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated aliphatic polyester film, particularly to a laminated film based on polylactic acid. A film having degradability is obtained.

[0002]

2. Description of the Related Art In recent years, there has been a growing demand for biodegradable films that do not require incineration due to increased environmental awareness and waste disposal problems in the disposal of unnecessary films. In response to this requirement, polyethylene terephthalate films and polyethylene naphthalate films conventionally used as film supports have no biodegradability and must be incinerated.

On the other hand, biodegradable films mainly composed of polylactic acid have been attracting attention because they are decomposed in the natural world and turned into harmless substances. In particular, polylactic acid biaxially stretched film has not only the characteristics of biodegradability, but also excellent transparency in a wide wavelength range, heat resistance comparable to biaxially stretched polypropylene film, mechanical strength similar to biaxially stretched polyester film, cellophane film Taking advantage of its excellent properties, such as moderate hand-cutting properties, twist fixing properties, and water vapor permeability, development is proceeding in a wide range of applications such as packaging films, agricultural films, and industrial films.

[0004] However, being biodegradable means that bacteria and mold are liable to be formed. In particular, the adhesion of bacteria and mold to food packaging films and medicine bags is not preferable in terms of safety and hygiene. In addition, there is a problem that the decomposition speed is not stable due to the distribution, storage, use environment of the end user, and the like, and the product is decomposed and deteriorated before disposal.

At present, antibacterial agents mainly studied or used include natural products such as chitin, chitosan, wasabi extract, mustard extract, hinokitiol, tea extract antibacterial agent, photooxidation catalyst titanium oxide particles, and zinc oxide. Examples include inorganic compounds such as ultrafine particles, silver-containing zeolite, and silver-containing zirconium phosphate, and synthetic products such as organic ammonium salt-based and organic phosphonium salt-based compounds.

[0006] Inorganic antibacterial agents represented by silver and natural products have low toxicity and are excellent in safety, but antibacterial activity is insufficient if a small amount is added to maintain transparency. In order to improve the antibacterial activity, transparency must be sacrificed, and there is practically room for improvement. In addition, it is difficult to exhibit sufficient antibacterial properties under low humidity, and furthermore, there is a problem that discoloration and spots are caused by light and heat, and the appearance is impaired.

On the other hand, antibacterial agents of low-molecular organic synthetic products are generally superior in antibacterial performance to fungi and the like to natural products and inorganic products. When the surface is coated or filled, the antibacterial agent has a low molecular weight, so it is easy to volatilize, desorb, and separate from a substrate such as a film,
It is not preferable from the viewpoint of long-term stability of antibacterial property and safety to human body.

For this reason, recently, an immobilized antibacterial material in which a low molecular organic antibacterial agent is bonded to a polymer material by an ionic bond or a covalent bond is disclosed in Japanese Patent Application Laid-Open Nos.
-266912, WO92 / 814365, and JP-A-5-310820.
These immobilized antibacterial materials are antibacterial materials in which a phosphonium base ionically bonded to an acidic group such as a carboxyl group or a sulfonic acid is immobilized on a polymer substance.

However, there is no example in which the organic immobilized antibacterial material is used for a polylactic acid film, and these organic immobilized antibacterial materials can impart antibacterial and antifungal properties to the polylactic acid film. The above publication does not describe at all whether the method is suitable for controlling the rate of biodegradability.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a laminated aliphatic polyester film having antibacterial and antifungal properties and capable of controlling the decomposition rate in nature.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above situation, and a laminated aliphatic polyester film which can solve the above-mentioned problems includes:
It is as follows.

1. The main repeating unit is represented by the general formula: -O
An aliphatic polyester film comprising a unit represented by —CHR—CO— (R is hydrogen or an alkyl group having 1 to 3 carbon atoms) is used as a base material, and at least one outermost layer contains an antibacterial resin composition. A laminated aliphatic polyester film having an antimicrobial resin layer.

2. 2. The laminated aliphatic polyester film according to the above item 1, wherein the aliphatic polyester is polylactic acid.

3. The antimicrobial resin composition is a polyester resin having a dicarboxylic acid component and a glycol component as main components and a phosphonium group of a sulfonic acid group-containing aromatic dicarboxylic acid represented by the following general formula (1). 3. The laminated aliphatic polyester film according to the above 1 or 2.

[0015]

Embedded image

Wherein A is an aromatic group, X ₁ and X ₂ are ester-forming functional groups, R ₁ , R ₂ , R ₃ and R ₄ are alkyl or aryl groups, at least one of which is carbon Number 1
An alkyl group of 0 or more and 20 or less, bonded to a phosphorus atom)

4. 4. The laminated aliphatic polyester film according to any one of the above items 1 to 3, wherein the antibacterial resin layer further contains a hydrophilic substance.

5. 5. The laminated aliphatic polyester film according to the above item 4, wherein the hydrophilic substance is a vinyl polymer having a hydrophilic group in a side chain, and this is grafted to an antibacterial resin composition.

6. 6. The laminated aliphatic polyester film according to any one of the above 1 to 5, wherein the antibacterial resin layer further contains a photopolymerizable curable resin.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The laminated aliphatic polyester film of the present invention will be described below.

(Biaxially stretched aliphatic polyester film)
The main repeating unit used in the present invention has the general formula -O-
Examples of the aliphatic polyester comprising a unit represented by CHR-CO- (R is hydrogen or an alkyl group having 1 to 3 carbon atoms) include polylactic acid, polyglycolic acid, and poly (2
-Oxybutyric acid) and the like, and one or more of these may be selected and used. When two or more kinds are used, a mixture or a copolymer may be used. Further, those having an asymmetric carbon in the polymer include L-form and DL-form.
There are optical isomers such as isomers and D-isomers, and any of these may be used, or a mixture of two or more isomers may be used. In addition, as the repeating unit other than the repeating unit represented by the above general formula contained in the aliphatic polyester, an aliphatic polyester unit derived from an oxycarboxylic acid, and / or an aliphatic carboxylic acid unit obtained from a diol and a dicarboxylic acid may be used. Is mentioned.

In addition to using these as a homopolymer, they may be used as a polymer mixture or a copolymer. Those having an asymmetric carbon in the polymer include L-form, D-form
There are optical isomers such as L-form and D-form, and any of them may be used, or a mixture of these isomers may be used. The polymer used as a material of these films uses a corresponding dehydrated cyclic ester compound of α-oxyacid,
It can be produced by a known method such as ring-opening polymerization.

The aliphatic polyester used in the present invention is:
The weight average molecular weight is from 5,000 to 500,000.
When the weight average molecular weight is less than 5,000, the physical properties of the obtained film are remarkably deteriorated, and the decomposition rate is too high, which is not preferable. In order to ensure sufficient extrudability during film production and biaxial stretching with a biaxial stretching machine, the weight average molecular weight is preferably 10,000 or more. On the other hand, a high viscosity polymer having a weight average molecular weight of 500,000 or more has a problem that melt extrusion becomes difficult. For these reasons, the preferable range of the weight average molecular weight is 40,000 to 300,000.

The aliphatic polyester film serving as the base material of the present invention has inorganic particles having an average particle diameter of 0.01 to 5 μm in the film in order to form irregularities on the film surface and improve handling properties. Inert particles such as organic salt particles and crosslinked polymer particles are added to the base polyester in an amount of 0.1%.
It is preferable that the content is 03 to 0.5% by weight.

The inorganic particles include calcium carbonate, kaolin, talc, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, and fluorine oxide. Lithium oxide and the like.

In particular, in order to obtain a film having a lower haze while maintaining good handling properties, the inorganic particles are preferably aggregated silica particles formed by aggregating primary particles.

The organic salt particles include calcium oxalate, terephthalate such as calcium, barium, zinc, manganese and magnesium.

Examples of the crosslinked polymer particles include divinylbenzene, styrene, acrylic acid, methacrylic acid, and homo- or copolymers of vinyl monomers of acrylic acid or methacrylic acid. In addition, organic particles such as polytetrafluoroethylene, benzoguanamine resin, thermosetting epoxy resin, unsaturated polyester resin, thermosetting urea resin, and thermosetting phenol resin may be used.

The method of adding the inert particles to the lactic acid-based polymer of the present invention is not particularly limited. The inert particles may be dispersed in molten lactide and added for polymerization, or the inert particles may be added during the synthetic polymerization reaction. There is a way to distribute.

In the aliphatic polyester film of the present invention, a nucleating agent, an antioxidant, a coloring inhibitor, a pigment, a dye, an ultraviolet absorber, a releasing agent, a lubricant, a flame retardant, a charge You may mix | blend an inhibitor.

The aliphatic polyester film as the base material of the present invention is preferably formed by extruding an aliphatic polyester at a specific extrusion temperature into an unstretched film, and biaxially stretching the unstretched film under specific conditions. .

In the melt extrusion of the aliphatic polyester, an unstretched sheet can be obtained by extruding the molten resin into a sheet on a cooling drum by a T-die and rapidly cooling and solidifying the sheet. The extrusion temperature ranges from the melting temperature (Tm) of the polymer to be used to Tm + 70 ° C.,
+20 to Tm + 50 ° C. If the extrusion temperature is too low, it is difficult to obtain extrusion stability, and it is easy to overload. On the other hand, if it is too high, the decomposition of the polymer becomes severe, which is not preferable. The die of the extruder used in the present invention may have an annular or linear slit. The temperature of the die may be as high as the extrusion temperature range.

The unstretched sheet thus obtained is preferably stretched at least uniaxially. The aliphatic polyester film serving as the base material of the present invention is more preferably a film heat-set after biaxial stretching.

The biaxial stretching of the unstretched sheet may be performed either sequentially or simultaneously with the stretching of the first axis and the stretching of the second axis. The method may be any of stretching between rolls having different speeds (roll stretching), stretching by gripping and expanding with clips (tenter stretching), and stretching by air pressure (inflation stretching). However, from the viewpoint of mechanical properties and the like, sequential biaxial stretching in which the film is first stretched in the machine direction and then stretched in the transverse direction is preferred. The sequential biaxial stretching in which the stretching is performed in the longitudinal and transverse directions will be specifically described as an example, but is not limited to the following method.

The stretching in the vertical and horizontal directions may be performed in one step or in multiple steps, but it is ultimately at least three times, more preferably 3.5 times or more in each stretching direction. Stretching at a lateral area magnification of 9 times or more, more preferably 12 times or more, is preferable in terms of thickness uniformity and mechanical properties. If the longitudinal and transverse stretching ratios are each 3 times or less and the area magnification is 9 times or less, it is difficult to obtain a film having good thickness uniformity, and it is difficult to sufficiently improve physical properties such as mechanical strength.

The stretching temperature is preferably in the range of the glass transition temperature (Tg) of the polymer used to Tg + 50 ° C. More preferably, it is in the range of Tg + 10 to Tg + 40 ° C. If the stretching temperature is lower than Tg, stretching is difficult, and Tg + 50 ° C.
Exceeding the thickness is not preferable because the thickness uniformity and the mechanical strength of the obtained film decrease.

The longitudinal stretching is preferably performed by roll stretching, and the heating method of the sheet during longitudinal stretching may be heating rolls, heating by infrared rays, or other methods. Also preheating,
A guide roll or a nip roll may be used anywhere on the stretching roll. Moreover, tenter stretching is desirable for transverse stretching.

In the present invention, the temperature is preferably 130 ° C. to Tm, more preferably 140 ° C. to 160 ° C.
Heat-treats the film with. At this time, a film having a smaller heat shrinkage can be obtained by performing the heat treatment while relaxing in the vertical and / or horizontal directions by 2% or more. By adopting the production conditions as described above, the heat shrinkage at 120 ° C. of the biaxially stretched aliphatic polyester film of the present invention can be reduced to 5% or less, further 3% or less. If the heat shrinkage ratio is more than 5%, printing misalignment is likely to occur in the printing process, and not only wrinkles are generated at the time of heat sealing but also the hand-cutting property is impaired, which is not preferable.

(Antimicrobial Resin Composition) In a polyester resin having a phosphonium group of a sulfonic acid group-containing aromatic dicarboxylic acid of the present invention, in a preferred embodiment, a sulfonic acid group-containing polyester resin represented by the following general formula (1) is used. The phosphonium base of the aromatic dicarboxylic acid is used in an amount of 1 to 5 relative to the total acid component.
It is a polyester resin copolymerized with 0 mol%.

[0040]

Embedded image

Wherein A is an aromatic group, X ₁ and X ₂ are ester-forming functional groups, R ₁ , R ₂ , R ₃ and R ₄ are alkyl or aryl groups, at least one of which is a carbon or aryl group. Number 1
An alkyl group of 0 or more and 20 or less, bonded to a phosphorus atom)

The dicarboxylic acid component used in the polyester resin includes terephthalic acid, isophthalic acid, 2,6
-Naphthalenedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and the like. Further, an alicyclic dicarboxylic acid, an aliphatic dicarboxylic acid, a heterocyclic dicarboxylic acid, or the like may be used in combination within a range not to impair the content of the invention. Examples of the alicyclic dicarboxylic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. Aliphatic dicarboxylic acids include succinic acid, glutaric acid, adipic acid, sebacic acid,
Dodecanedicarboxylic acid, azelaic acid, eicoic acid, dimer acid and derivatives thereof. Heterocyclic dicarboxylic acids include pyridine carboxylic acid and its derivatives. Further, an oxycarboxylic acid such as p-oxybenzoic acid and a polyvalent carboxylic acid such as trimellitic anhydride and pyromellitic anhydride may be used in combination as long as the content of the invention is not impaired. Among these, it is preferable to contain an aromatic dicarboxylic acid in an amount of 70 mol% or more from the viewpoint of practical durability when formed into a coating film. As other dicarboxylic acids, 1,4-dicarboxylic acid, adipic acid and sebacic acid are particularly preferred.

The glycol components include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentadiol, neopentyl glycol, , 6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 1,9-nonanediol, 1,10 -Alkylene glycols such as -decanediol; alicyclic glycols such as 1,2-cyclohexanedimethanol; alkylene oxide adducts of bisphenol A or F; diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. In addition, a small amount of amide bond, urethane bond,
It may contain a compound containing an ether bond or a carbonate bond. Among these, ethylene glycol, neopentyl glycol, 2-methyl 1,3 are preferable from the viewpoint of practical durability when formed into a coating film.
-Propanediol, 1,6-hexanediol, 1,
5-pentanediol, 3-methyl-1,5-pentanediol, and 1,4-cyclohexanedimethanol.

A polyhydric polyol such as trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol may be used in combination as long as the content of the invention is not impaired.

Examples of the phosphonium salt of a sulfonic acid group-containing aromatic dicarboxylic acid include tri-n-sulfoterephthalic acid.
Butyldecylphosphonium salt, tri-n-butyloctadecylphosphonium sulfoterephthalate, tri-n-butylhexadecylphosphonium sulfoterephthalate, tri-n-butyltetradecylphosphonium sulfoterephthalate, tri-n-sulfoterephthalate Butyl dodecylphosphonium salt, tri-n sulfoisophthalate
-Butyldecylphosphonium salt, tri-n-butyloctadecylphosphonium sulfoisophthalate, tri-n-butylhexadecylphosphonium sulfoisophthalate, tri-n-butyltetradecylphosphonium sulfoisophthalate, sulfoisophthalic acid-n- Butyl dodecyl phosphonium salt, 4-sulfonaphthalene-2,7-
Dicarboxylic acid tri-n-butyldecylphosphonium salt,
4-sulfonaphthalene-2,7-dicarboxylic acid tri-n
-Butyloctadecylphosphonium salt, 4-sulfonaphthalene-2,7-dicarboxylic acid tri-n-butylhexadecylphosphonium salt, 4-sulfonaphthalene-2,7
-Dicarboxylic acid tri-n-butyltetradecylphosphonium salt, 4-sulfonaphthalene-2,7-dicarboxylic acid tri-n-butyldodecylphosphonium salt, and the like, and from the viewpoint of antibacterial activity, trisulfoisophthalic acid tri-n-
Butyl hexadecyl phosphonium salt, tri-n-butyl tetradecyl phosphonium sulfoisophthalate, and tri-n-butyl dodecyl phosphonium sulfoisophthalate are particularly preferred.

The above-mentioned phosphonium salts of aromatic dicarboxylic acids include tri-n-butylhexadecylphosphonium bromide, tri-n-butyltetradecylphosphonium bromide, tri-n-butylhexadecylphosphonium bromide and sulfoaromatic dicarboxylic acids or their sodium, potassium and ammonium salts. It can be obtained by reacting a phosphonium salt such as n-butyldodecylphosphonium bromide. The reaction solvent at this time is not particularly limited, but water is most preferable.

For the purpose of improving the heat resistance such as the degree of coloring and the degree of gelation, the copolymerized polyester may be a magnesium salt such as magnesium acetate or magnesium chloride, or calcium acetate, in addition to a polymerization catalyst such as antimony oxide, germanium oxide or a titanium compound. , Ca salts such as calcium chloride, manganese acetate, Mn salts such as manganese chloride, zinc chloride, Zn salts such as zinc acetate,
It is also possible to add a Co salt such as cobalt chloride or cobalt acetate at 300 ppm or less as a metal ion, respectively, and phosphoric acid or a phosphate derivative such as trimethyl phosphate or triethyl phosphate at 200 ppm or less as P. If the total amount of metal ions other than the polymerization catalyst is more than 300 ppm and the amount of P exceeds 200 ppm, not only the coloring of the polymer becomes remarkable, but also the heat resistance and hydrolysis resistance of the polymer are remarkably reduced.

At this time, in terms of heat resistance, hydrolysis resistance and the like, the molar ratio between the total P amount and the total metal ion amount is 0.4 to 0.4.
It is preferably 1.0. The molar atomic ratio is 0.4
If it is less than 1.0 or more than 1.0, the composition of the present invention is not preferable because coloring and generation of coarse particles become remarkable.

The method for producing the polyester is not particularly limited, and a so-called direct polymerization method in which an oligomer obtained by directly reacting a dicarboxylic acid and a glycol is polycondensed,
A so-called transesterification method in which a dimethyl ester of a dicarboxylic acid and a glycol are subjected to transesterification and then polycondensation, and the like, may be used, and an arbitrary production method can be applied.

The timing of addition of the above metal ions and phosphoric acid and its derivatives is not particularly limited. Generally, metal ions are added by polycondensation at the time of charging raw materials, that is, before transesterification or esterification. It is preferably added before the reaction.

In the antimicrobial resin composition of the present invention, it is necessary to mix or chemically bond a hydrophilic substance to a polyester resin containing a phosphonium base. The presence of a hydrophilic substance significantly improves antibacterial properties. The biodegradation rate of the substrate film can be controlled by the amount of the hydrophilic substance added (copolymerization amount).

The hydrophilic substance in the present invention is a substance having an excellent affinity for water, and is a substance which can be dissolved, dispersed or water-retaining, moisturizing and swellable in water. A hydrophilic group or a derivative thereof such as a carboxylic acid group or an alkali metal salt thereof, a sulfonic acid group or an alkali metal salt thereof, or an organic compound or a polymer compound containing two or more ether bonds in one molecule. Are polyvinyl alcohol, starch, homopolymer or copolymer of acrylic acid, homopolymer or copolymer of methacrylic acid, homopolymer or copolymer of maleic anhydride (for example, maleic anhydride-styrene copolymer), Homopolymers or copolymers of vinyl sulfonic acid or their alkali metal salts, polyethylene glycol (also known as Tylene oxide), polypropylene glycol, polyethylene propylene glycol,
Polyalkylene glycols such as polytetramethylene glycol, glycerin, polyols such as polyglycerin or polymers thereof, glycerin, polyglycerin, hydroxyethyl cellulose as a water-soluble modified cellulose,
Examples include methylcellulose, methylhydroxypropylcellulose, sodium carboxycellulose, and cellulose nitrate carboxyl methyl ether.
These are mixed and used in the polyester resin containing the phosphonium base. The molecular weight of the hydrophilic substance is not particularly limited, but in the case of polyethylene glycol, the number average molecular weight is preferably from 200 to 30,000, and more preferably from 1,000 to 25,000.

The amount of the hydrophilic substance (in the case of a copolymer, the hydrophilic substance to be incorporated in the copolymer) is 0.1 to 20% by weight, preferably 0.5 to 20% by weight, based on the polyester resin.
It is 10% by weight, more preferably 1 to 5% by weight. 0.
If it is less than 1% by weight, the effect of increasing the antibacterial activity is insufficient, and if it exceeds 20% by weight, the mechanical properties and heat resistance and weather resistance of the antibacterial composition are undesirably reduced. The method of mixing with the hydrophilic substance is not particularly limited, and any method can be adopted depending on the method of producing the polyester resin, its chemical properties, and its physical properties. For example, a method in which both are heated and melt-mixed using an extruder, or a method in which a polymer substance and a hydrophilic substance are mixed in an appropriate solvent such as water, a water / alcohol mixed solvent, or an organic solvent such as acetone, methyl ethyl ketone, or cyclohexanone. After mixing and dissolving or dispersing, there is a method of drying the solvent to dryness.

In addition, as a method for introducing a hydrophilic substance, a hydrophilic group such as an amino group, an amide group, a carboxylic acid group or an alkali metal salt thereof, a sulfonic acid group or an alkali metal salt thereof, or the like is added to a polyester resin containing a phosphonium base. These derivatives can be copolymerized into the main or side chains. By copolymerization, the compatibility is improved, and the appearance, storage stability, and physical properties of the coating film are improved. Methods for copolymerizing these hydrophilic groups include metal salts such as 5-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5 (4-sulfophenoxy) isophthalic acid, or 2-sulfo-isophthalic acid.
A method of copolymerizing a dicarboxylic acid or glycol containing a sulfonic acid metal base such as a metal salt such as 1,4-butanediol and 2,5-dimethyl-3-sulfo-2,5-hexanediol with a polyester resin, polyethylene Examples thereof include a method of copolymerizing an alkylene glycol such as glycol, polypropylene glycol, and polytetramethylene glycol with a polyester resin, and a method of graft-polymerizing a vinyl-based monomer containing a hydrophilic group onto the polyester resin.

As the vinyl monomer having a hydrophilic group which can be grafted onto the polyester resin in the present invention, those containing a carboxylic acid group, a hydroxyl group, a sulfonic acid group, an amide group, etc., or a hydrophilic group can be used. Examples of groups that can be formed include those containing an acid anhydride group, a glycidyl group, a chloro group, and the like. Among them, those having a carboxylic acid group are most preferred. For example, monomers containing a carboxylic acid group such as acrylic acid, methacrylic acid and salts thereof or salts thereof, and alkyls such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate and t-butyl acrylate Acrylate, methyl methacrylate,
Ethyl methacrylate, n-butyl methacrylate, t
-Alkyl methacrylates such as butyl methacrylate,
Hydroxy-containing monomers such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, acrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-
Methylol methacrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide,
Amide group-containing monomers such as N, N-dimethylolacrylamide and N-phenylacrylamide, and epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate.

Other monomers having a hydrophilic group include, for example, monomers containing an epoxy group such as allyl glycidyl ether, monomers containing a sulfonic acid group or a salt thereof such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof, Monomers containing a carboxylic acid group or a salt thereof, such as crotonic acid, itaconic acid, maleic acid, fumaric acid, and salts thereof, and monomers containing an acid anhydride, such as maleic anhydride and itaconic anhydride. These can be used in combination with other monomers. As other monomers, for example, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, acrylonitrile, methacrylonitrile,
Examples thereof include vinylidene chloride, vinyl acetate, and vinyl chloride, and one or two of these can be used for copolymerization.

The ratio between the monomer having a hydrophilic group and the other monomer is preferably in the range of 30/70 to 100/0 in molar ratio. When the ratio of the monomer having a hydrophilic group is 30
If it is less than mol%, the effect of enhancing antibacterial properties cannot be sufficiently exhibited.

As a method for grafting a monomer having a hydrophilic group to the polyester, a known graft polymerization method can be used. The following method is mentioned as a typical example. For example, a radical polymerization method in which radicals are generated in a main chain polymer substance by light, heat, radiation, or the like, and then the monomers are graft-polymerized, or AlCl ₃ ,
There are a cation polymerization method in which cations are generated using a catalyst such as TiCl _4, and an anion polymerization method in which anions are generated using metal Na, metal Li, or the like.

Further, there is a method in which a polymerizable unsaturated double bond is previously introduced into a main chain polymer substance, and a vinyl monomer is reacted with the polymerizable unsaturated double bond. Examples of the monomer having a polymerizable unsaturated double bond used therein include fumaric acid, maleic acid, maleic anhydride, tetrahydromaleic anhydride and the like. The most preferred of these are fumaric acid, maleic acid, and 2,5-norbornene dicarboxylic acid.

Further, there is a method in which a main chain high molecular substance having a functional group introduced into a side chain is reacted with a branch polymer having a group which reacts with the above functional group at the terminal. For example the side chain -OH group, -SH group, -NH ₂ group, -COOH group, -
A polymer having a hydrogen donating group such as a CONH ₂ group, and one end having a —N ＝ C ＝ O group, a —C ＝ C ＝ O group, an epoxy group,

[0061]

Embedded image

And a reaction in the reverse combination.

The preferred weight ratio of the polyester as the main chain of the present invention to the vinyl monomer to be grafted is 95 /
5/40/60, more preferably 93/60.
7-55 / 45, most preferably 90 / 10-60 / 4
It is in the range of 0. If the weight ratio of the main chain polymer substance is less than 40%, the graft polymerizable vinyl monomer remains without completely reacting, and the properties of the conventional polymer such as heat resistance, processability, and water resistance are impaired. It is. When the weight ratio of the main chain polymer substance exceeds 95%, the effect of improving the antibacterial property, which is the object of the present invention, is not sufficiently exhibited. There is no significant difference in the antibacterial effect between the case where the hydrophilic substance is mixed with the polymer substance and the case where the hydrophilic substance is copolymerized, and good antibacterial properties are obtained.

The present invention is characterized in that a photopolymerizable curable resin is blended in addition to the above-mentioned polyester and hydrophilic substance. Curable resins are broadly classified into thermosetting resins and ionizing radiation-curable resins, but ionizing radiation-curable resins are excellent from the viewpoints of flexibility in resin design, rapid curability, and work environment. Good film properties can be obtained by blending a curable resin. The ionizing radiation-curable resin is formed from a composition containing at least a resin that is cured by irradiation with an electron beam or ultraviolet rays. Specifically, it contains a photopolymerization initiator, a photopolymerizable prepolymer, and further contains a photopolymerizable monomer, a photosensitizer, an additive such as a leveling agent, a solvent, and the like, if necessary.

The photopolymerizable prepolymer undergoes radical polymerization or ionic polymerization when a reactive group inserted into the molecular skeleton is irradiated with ionizing radiation. A typical example of the radical polymerizable prepolymer is an acrylic prepolymer having an acryloyl group, and a typical example of the ionic polymerizable prepolymer is an epoxy prepolymer having an epoxy group. The acrylic prepolymer has two or more acryloyl groups in one molecule, and urethane acrylate, epoxy acrylate, polyester acrylate and the like can be used. The higher the number of functional groups, the faster the curability and the higher the hardness. As the epoxy-based prepolymer, epoxy oligomers such as bisphenol A type, hydrogenated bisphenol A type, bisphenol F type, phenol novolak type and alicyclic type can be used. In the epoxy prepolymer, the epoxy group is cationically ring-opened and polymerized, so that a thermal factor affects the curing reaction, and the temperature is 50 ° C. to 6 ° C. during or after irradiation with ionizing radiation.
By heating to about 0 ° C., the curing reactivity can be further increased. The preferable amount of the photopolymerizable prepolymer is 5 to 60% by weight, more preferably 15 to 50%, based on the total amount of the polyester and the hydrophilic substance.

The photopolymerization initiator is added to start the reaction of acryloyl group in a short time in the radical polymerizable prepolymer and promote the reaction, and acts as a catalyst. Photoinitiators include those that undergo radical polymerization by self-cleavage and those that undergo radical polymerization by extracting hydrogen. For the former, benzoin ethers, dialkoxyacetophenones, hydroxyacetophenones, morpholinoacetophenones, etc. are used, and for the latter, benzophenones, cyclic benzophenones, benzyl, etc. are used, and one or more of these can be used. . In the ionic polymerizable prepolymer, the photopolymerization initiator is a compound which absorbs ionizing radiation energy and releases a catalyst component for initiating cationic polymerization, and includes an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, and a metallocene. Compounds and the like are used. The compounding amount of the photopolymerization initiator is preferably 1 to 10% by weight, more preferably 2 to 5% by weight, based on the solid content of the resin.

In the photopolymerizable curable resin, a photopolymerizable monomer is added, if necessary, in addition to the above-mentioned photopolymerizable prepolymer and photopolymerization initiator. Particularly, in the case of a radical polymerizable prepolymer, it is effective for diluting a high-viscosity photopolymerizable prepolymer to improve the workability by lowering the viscosity and for imparting a coating film strength as a crosslinking agent. Monofunctional acrylic monomers such as 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, and 1, as photopolymerizable monomers for radical polymerization.
One or more of a bifunctional acrylic monomer such as 6-hexanediol diacrylate and a polyfunctional acrylic monomer such as trimethylolpropane triacrylate are used.

When the antimicrobial resin composition of the present invention is irradiated with an ionizing radiation such as an electron beam or an ultraviolet ray, the photocurable resin reacts and cures, and good coating film properties can be obtained. When irradiating with an electron beam, a scanning or curtain type electron beam accelerator is used, has an acceleration voltage of 1000 keV or less, preferably 100 to 300 keV, and has an energy of 100 nm.
Irradiation with an electron beam in the following wavelength range can be performed.
When irradiating ultraviolet rays, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc, a metal halide lamp, or the like is used, and 100 to 400 nm, preferably 200 to 400 n.
In the wavelength region of m, ultraviolet rays having an integrated light amount of ²⁰ to 1500 mJ / cm ² are irradiated.

The antimicrobial composition of the present invention is preliminarily incorporated into the antimicrobial composition with calcium carbonate, calcium phosphate, apatite, sulfuric acid for the purpose of improving physical properties such as slipping property, abrasion resistance, blocking resistance, concealing property and the like. Barium, calcium fluoride, talc, kaolin, silicon oxide, alumina, titanium dioxide, zirconium oxide (ZrO ₂ ), iron oxide,
It is also possible to add inorganic particles such as alumina / silica composite oxide, and organic particles such as polystyrene, polymethacrylate, polyacrylate, a copolymer thereof, or a cross-linked product thereof.

The antimicrobial resin composition of the present invention can be prepared by a usual coating method such as bar coating, blade coating, gravure coating, spin coating, spray coating, dip coating, etc. After applying to wood, ceramics, etc., after a drying step as necessary, it can be cured by irradiating with an electron beam or an ultraviolet ray to obtain a laminate having a curable resin layer having excellent antibacterial properties and durability. it can.

[0071]

EXAMPLES Hereinafter, the contents and effects of the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to the following examples unless departing from the gist thereof. The methods for evaluating physical properties in Examples and Comparative Examples are as follows.

1. Antibacterial test S.I. diluted with 1/50 broth aureus (Staphylococcus aureus) bacterial solution (concentration: 10 ⁶ cells / ml) 0.1 m
1 was dropped on a sample film having a size of 5 cm × 5 cm which had been sterilized with high pressure steam in advance, and a Saran wrap film which had been sterilized with high pressure steam was adhered to the film. The test piece was transferred to a sterile petri dish and cultured at 37 ° C. for 24 hours. Then, the bacteria on the film were washed with 10 ml of SCDLP medium, diluted 10-fold, spread on a normal agar plate, and the number of bacteria was counted 24 hours later. The antibacterial activity is evaluated by a bacteriostatic activity value according to the following formula. Bacteriostatic activity value = (logA-logB) A: 2 in polyester film without antimicrobial layer
Number of bacteria measured after 4 hours of culture B: Number of bacteria measured after 24 hours of culture on antibacterial / mold-resistant laminated film

2. Store biodegradable film in compost at 60 ° C for 1 month
After a month, this film was taken out, and its appearance change and the tensile strength retention rate (%) [(tensile strength after storage /
Tensile strength before storage) × 100] was used to determine the presence or absence of biodegradability. ：: Highly biodegradable (remarkable change in appearance is observed,
Δ: Moderate biodegradability (appearance change is observed, tensile strength retention is 50% or less) ×: No biodegradability (no significant change in appearance) , Retention of tensile strength is over 50%)

(Production Example 1 of Polyester Resin) Stirrer,
In a stainless steel autoclave equipped with a thermometer and a partial reflux condenser, 485 parts by weight of dimethyl terephthalate, 388 parts by weight of dimethyl isophthalate, 161 parts by weight of tri-n-butyl dodecyl phosphonium salt of 5-sulfodimethylisophthalic acid (C12 phosphonium salt) , 443.3 parts by weight of ethylene glycol, 400.4 parts by weight of neopentyl glycol, and 0.52 part of tetra-n-butyl titanate, and a transesterification reaction was performed at 160 to 220 ° C. for 4 hours. Then fumaric acid 2
9 parts were added, the temperature was raised to 200 to 220 ° C. over 1 hour, and the reaction system was gradually decompressed. Then, the reaction was carried out for 1 hour and 30 minutes under a reduced pressure of 26.7 Pa to obtain a polyester (A-1). . Table 1 shows the composition of the polyester.

By the same method, various polyesters (A-2, A-3) having the compositions shown in Table 1 were produced.

Production Example 1 of Graft Polymer 300 parts by weight of polyester (A-1), 360 parts by weight of methyl ethyl ketone, 120 parts by weight of isopropyl alcohol were placed in a reactor equipped with a stirrer, a thermometer, a reflux device and a metered addition device.
The resin was dissolved in a reflux state by heating and stirring. After the resin was completely dissolved, a mixture of 65 parts by weight of acrylic acid, 35 parts by weight of ethyl acrylate, 1.5 parts by weight of octyl mercaptan, azobisisobutyronitrile 6
A solution prepared by dissolving 90 parts by weight of methyl ethyl ketone and 30 parts by weight of isopropyl alcohol was added dropwise to the polyester solution over a period of 1.5 hours, and the mixture was further reacted for 3 hours. A combined solution (B-1) was obtained. In a similar manner, the polyesters (A-2, A-3) were subjected to graft polymerization to obtain graft polymers (B-2, B-3).

Preparation Example 2 of Graft Polymer The same as Preparation Example 1 except that the amount of acrylic acid was changed to 20 parts by weight and the amount of ethyl acrylate was changed to 10 parts by weight. By the method, a graft polymer solution (B-4) was obtained.

Preparation Example 3 of Graft Polymer Preparation Example 1 was repeated except that 35 parts by weight of N-methylacrylamide and 65 parts by weight of acrylamide were used in Preparation Example 1 of the graft polymer.
A graft polymer solution (B-5) was obtained in the same manner as in the above.

Preparation Example 4 of Graft Polymer Graft polymer was prepared in the same manner as in Preparation Example 1, except that styrene and 85 parts by weight of styrene and vinyl acetate were used as grafting monomers. A polymer solution (B-6) was obtained.

Production Example 1 of Polylactic Acid Film 100 parts by weight of poly-L-lactic acid having a weight average molecular weight of 200,000 were used as inactive particles for forming surface projections, as aggregated silica having an average particle size of 1.8 μm. Poly-L-lactic acid containing 0.06 parts by weight of particles with respect to the produced polyester,
Resin temperature 210 ° C by a 30mm diameter extruder with T die
And then cooled with a chill roll at 20 ° C.
An unstretched film of 0 μm was obtained. The film temperature of the unstretched film is set to 95 ° C. by a plurality of ceramic rolls.
The film was stretched 1.4 times in the machine direction at a stretching speed of 30,000% / min between rolls, and further stretched 2.5 times in the longitudinal direction at 97 ° C. Next, 100 times in the transverse direction by a tenter type stretching machine.
After stretching 4 times at ℃, it was heat-set at 155 ° C and subjected to a 3% transverse relaxation treatment at 135 ° C. Further, the obtained film was
℃, corona treatment, 50μm thick poly
A biaxially stretched film of L-lactic acid was obtained. The heat shrinkage in the longitudinal direction at 120 ° C. of the obtained film was 2.3%.

Example 1 Polyester (B-4): 100 parts by weight of solid content
One-part type epoxy photopolymerizable prepolymer containing a photoinitiator (C-2: Adeka KR566, manufactured by Asahi Denka Co., Ltd.)
After adding 33 parts by weight, the coating liquid was diluted with methyl ethyl ketone so that the total solid content concentration became 17% by weight. Then, a coating solution was applied on one side of a polylactic acid film having a thickness of 50 μm with a bar coater so that the coating amount was 1.5 g / m ² , dried in a hot air oven at 120 ° C. for 3 minutes, and then irradiated with ultraviolet rays. 9 with device
Ultraviolet rays of an integrated irradiation light amount of 00 mJ / cm ² were irradiated and cured to obtain a laminate having a cured coating film on the surface layer. Table 3 shows the properties of the laminated film.

Examples 2 to 5 In place of the polyester (B-1), the polyester (B
Except for using -2, 4, 5, 6), a laminated aliphatic polyester film was obtained in the same manner as in Example 1. Table 3 shows the properties of the laminated film.

Comparative Example 1 Polyester (B-1) was used instead of polyester (B-1).
Except for using -3), a laminated aliphatic polyester film was produced in the same manner as in Example 1. Table 3 shows the properties of the laminated film.

Comparative Example 2 A biaxially stretched polyethylene terephthalate film (Ester Film E5100, manufactured by Toyobo Co., Ltd.) having a thickness of 50 μm was used as a base film, and an antibacterial and fungicide layer was formed in the same manner as in Example 1. A laminated film was obtained. Table 3 shows the properties of the laminated film.

Comparative Example 3 As a base film, a biaxially stretched polypropylene film having a thickness of 50 μm (Pyrene film P2 manufactured by Toyobo Co., Ltd.)
161) was used to obtain a laminated film having an antibacterial and antifungal layer formed in the same manner as in Example 1. Table 3 shows the properties of the laminated film.

COMPARATIVE EXAMPLE 4 A biaxially stretched nylon 6 film having a thickness of 50 μm obtained by a known method was used as a base film, and a laminated film having an antibacterial and antifungal layer formed in the same manner as in Example 1 was used. Obtained. Table 3 shows the properties of the laminated film.

[0087]

[Table 1]

[0088]

[Table 2]

[0089]

[Table 3]

[0090]

Since the aliphatic polyester film of the present invention has an antibacterial / mold-resistant resin layer as the outermost layer, the decomposition rate in the natural world can be controlled arbitrarily.

Front page of the continued F-term (reference) 4F100 AH02B AH02C AH04B AH04C AH07B AH07C AH10B AH10C AK21B AK21C AK41A AK41B AK41C AL05B AL05C AR00B AR00C BA02 BA03 BA06 BA10B BA10C EH462 EJ082 EJ542 EJ862 GB01 GB15 JB05B JB05C JB14B JB14C JG00B JG00C 4H011 AA02 BB17 BB19 BC19 DA07 DH04 DH19 DH29 4J029 AA03 AB07 AC02 AE03 BA02 BA03 BA04 BA05 BA07 BA08 BA10 BD06A BF09 BF25 BF26 BH01 CA02 CA04 CA05 CA06 CB05A CB06A CC06A CD03 CH02 CH03 DA14 DB02 DC08 EB05A GA12 JE182

Claims (6)

[Claims] The main repeating unit is represented by the general formula: -O-
An aliphatic polyester film comprising a unit represented by CHR-CO- (R is hydrogen or an alkyl group having 1 to 3 carbon atoms) is used as a base material, and at least one outermost layer contains an antibacterial resin composition. A laminated aliphatic polyester film having an antibacterial resin layer. 2. The laminated aliphatic polyester film according to claim 1, wherein the aliphatic polyester is polylactic acid. 3. An antimicrobial resin composition comprising a dicarboxylic acid component and a glycol component as main components, and represented by the following general formula (1):
The laminated aliphatic polyester film according to claim 1 or 2, which is a polyester resin having a phosphonium group of a sulfonic acid group-containing aromatic dicarboxylic acid represented by the following formula: Embedded image (Where A is an aromatic group, X ₁ and X ₂ are ester-forming functional groups, R ₁ , R ₂ , R ₃ and R ₄ are alkyl groups or aryl groups, at least one of which has 10 or more carbon atoms.) An alkyl group of 20 or less, which is bonded to a phosphorus atom) 4. The laminated aliphatic polyester film according to claim 1, wherein the antibacterial resin layer further contains a hydrophilic substance. 5. The laminated aliphatic polyester according to claim 4, wherein the hydrophilic substance is a vinyl polymer containing a hydrophilic group in a side chain, and is grafted to an antibacterial resin composition. the film. 6. The laminated aliphatic polyester film according to claim 1, wherein the antibacterial resin layer further contains a photopolymerizable curable resin.