CN109844216B

CN109844216B - Transfer paper

Info

Publication number: CN109844216B
Application number: CN201780050277.7A
Authority: CN
Inventors: 五十岚宏二; 浦崎淳
Original assignee: Mitsubishi Paper Mills Ltd
Current assignee: Mitsubishi Paper Mills Ltd
Priority date: 2016-09-29
Filing date: 2017-07-03
Publication date: 2022-03-08
Anticipated expiration: 2037-07-03
Also published as: WO2018061376A1; CN109844216A

Abstract

A transfer paper having a base paper and at least one coating layer on at least one surface of the base paper, wherein the outermost coating layer positioned outermost with respect to the base paper contains at least a pigment, a binder, a polyacrylate and an acetylene glycol derivative, and having excellent image deterioration resistance, good color development properties and excellent adhesion, and a transfer printing method using a sublimation printing ink.

Description

Transfer paper

Technical Field

The present invention relates to a transfer sheet used for transferring a pattern in a transfer printing method for forming a pattern on a target printed material such as a fibrous material.

Background

As a method for forming a pattern on a printing object such as a fibrous material, the following transfer printing method is known: a sublimation type printing ink is transferred to a printed object by printing a pattern on transfer paper using the sublimation type printing ink to produce transfer paper and causing the transfer paper to adhere to the printed object (see, for example, patent document 1 and patent document 2).

Transfer papers used in a transfer printing method are known.

For example, as a sublimation transfer sheet having excellent absorbability of aqueous ink, which can provide clear recorded images without bleeding and excellent ink transfer efficiency to a transfer target during sublimation transfer, the following sublimation transfer sheets are known: the sublimation transfer sheet is characterized by comprising a sheet-like base material and an ink receiving layer provided on one surface or both surfaces of the sheet-like base material, wherein the ink receiving layer contains a pigment, a binder and a cationic resin, precipitated silica is used as the pigment, and 1 or a mixture of 2 or more of starch, a starch derivative, polyvinyl alcohol and modified polyvinyl alcohol is used as the binder (see, for example, patent document 3).

Further, as sublimation printing type transfer paper having excellent ink drying properties and offset resistance and also having good characteristics in terms of image reproducibility by transfer and transfer efficiency, sublimation printing type transfer paper as follows is known: the sublimation printing ink-receiving layer is formed by dispersing a water-soluble resin as a main component and fine particles, and contains a nonionic surfactant, and has a surface having irregularities formed thereon (see, for example, patent document 4).

Further, as a sublimation type ink jet printing transfer paper which is excellent in absorption and drying properties of sublimation type printing ink at the time of ink jet printing, has excellent image reproducibility and offset resistance, and is also excellent in transfer efficiency at the time of transfer printing to a transfer target, the following sublimation type ink jet printing transfer paper is known: wherein a sublimation type printing ink-receiving layer is formed on a substrate having a 10-second Cobb water absorption of 5 to 20g/m²The sublimation type printing ink-receiving layer is formed of an ink-receiving layer coating material containing a water-soluble resin and fine particles, the water-soluble resin being at least carboxymethyl cellulose, and the carboxymethyl cellulose 100 ℃eis contained in the ink-receiving layer coating material per 100 parts by mass of the fine particles400 parts by mass of inorganic fine particles having at least a planar crystal structure, a median diameter d50 of 0.4 to 2.3 μm, an aspect ratio of 5 to 30, and a coating weight of the ink-receiving layer coating of 3 to 13g/m²The average value of the pinhole counts is 5 or less (see, for example, patent document 5).

Transfer papers suitable for inkjet printing, which are provided with a release layer or a barrier layer and have a porosity of at most 100 ml/min, are known (see, for example, patent document 6).

As a method for producing transfer paper by printing a pattern on transfer paper using sublimation dye-containing ink or sublimation printing ink, an ink jet printing method is often used as described in patent documents 3 to 6.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-168705

Patent document 2: japanese patent laid-open publication No. 2015-124324

Patent document 3: japanese patent application laid-open No. 2010-158875

Patent document 4: japanese laid-open patent publication No. 2009-131958

Patent document 5: japanese patent laid-open publication No. 2016-159483

Patent document 6: japanese Kohyo publication No. 2002-521245

Disclosure of Invention

Problems to be solved by the invention

Transfer paper that is blank paper before a pattern is printed and transfer paper on which a pattern is printed need to have 2 types of characteristics opposite to each other. That is, the transfer paper is required to have a good ability to receive the sublimation printing ink, and the transfer paper is required to have a good ability to transfer the sublimation printing ink to the object to be printed.

In order to form a transfer paper having a clear image so that the image quality of the pattern formed on the object to be printed does not deteriorate, it is necessary to improve the receptivity to the sublimation type printing ink. Further, the transfer paper is required not to deteriorate the image quality of the pattern formed on the object to be printed by the transfer paper having a clear image.

On the other hand, in the case where the receptivity of the transfer paper to the sublimation type printing ink is improved, the sublimation type printing ink may not be sufficiently transferred at the time of transferring the object to be printed with the pattern. As a result, color developability is reduced in the printed matter.

In addition, in order to transfer the print material by bringing the transfer paper into close contact with the print material, the transfer paper must be able to adhere well to the print material. In addition to the deterioration of image quality during image formation, there is a problem in image quality caused by failure in good adhesion between the transfer paper and the object to be printed. In a region where the transfer paper and the object to be printed are not in good contact with each other, image blurring, distortion, or the like occurs.

When the transfer is continuously performed to the object, the transfer is performed by bringing the transfer paper in a roll form into close contact with the object. In particular, in order to perform continuous transfer, it is more important that the transfer paper and the object to be printed are in good adhesion.

In addition, in the transfer printing method, fogging (カブリ) is a problem of image quality different from the case where the image quality of a pattern formed on a target object is deteriorated. The fogging means: a phenomenon that, when sublimation type printing ink is transferred from a transfer paper to a printed object, the sublimation type printing ink is sublimated to a region different from a pattern and transferred. Typically, the phenomenon of stain stains on white substrates occurs. Although a method of suppressing fogging by a sublimation type printing ink technique has been studied, a method of suppressing fogging by a transfer paper has also been sought.

In order to transfer the sublimation type textile printing ink from the transfer paper to the object to be printed satisfactorily, the transfer paper must receive the sublimation type textile printing ink without allowing the sublimation type textile printing ink to penetrate deep into the transfer paper. That is, the transfer paper is required to suppress strike-through. "strike-through" refers to a phenomenon in which sublimation dye ink of an image printed on transfer paper penetrates into the deep part of the paper.

In addition, as a method of printing a pattern on transfer paper to produce transfer paper, an ink jet printing method is often used. In the inkjet printing method, transfer paper and transfer paper are often handled in a roll paper state, and in the roll paper state, evaporation of an ink solvent tends to be slow. Transfer paper wound in a roll shape after printing is required to be capable of absorbing sublimation type printing ink without bleeding until the ink solvent evaporates.

The quality of the sublimation transfer sheet of patent document 3, the sublimation printing type transfer paper of patent document 4, the sublimation printing type transfer paper of patent document 5, and the sublimation inkjet printing type transfer paper of patent document 6 is not sufficient, and particularly, improvement is desired in terms of good adhesion between the transfer paper and the object to be printed or suppression of fogging.

In view of the above, an object of the present invention is to provide a transfer paper satisfying the following items.

(1) Can suppress the deterioration of the image of the printed matter (resistance to image deterioration)

(2) Can inhibit the decrease of color development (color development property) of the printed matter

(3) The transfer paper is well sealed (sealing property) with the printed matter

Further, in a preferred embodiment, a transfer paper satisfying the following items is provided.

(4) Can inhibit the printed matter from fogging (fogging resistance)

(5) Capable of suppressing strike-through of transfer paper (strike-through resistance)

(6) Transfer paper capable of absorbing ink without bleeding (ink-absorbing property)

Means for solving the problems

The present inventors have made extensive studies to solve the above problems, and as a result, the object of the present invention is achieved by the following means.

[1] A transfer paper for use in a transfer printing method using a sublimation printing ink, the transfer paper having a base paper and at least one coating layer of 1 or more on at least one surface of the base paper, wherein the outermost coating layer positioned outermost with respect to the base paper contains at least a pigment, a binder, a polyacrylate and an acetylene glycol derivative.

Thus, the transfer paper can have image deterioration resistance, color development properties, and adhesion.

[2] The transfer paper according to the above [1], wherein the content of the polyacrylate in the outermost coating layer is 0.1 parts by mass or more and 3.5 parts by mass or less with respect to 100 parts by mass of the binder.

This improves the color development and adhesion of the transfer paper.

[3] The transfer paper according to the above [1] or [2], wherein the polyacrylate salt is ammonium polyacrylate.

This improves the image deterioration resistance of the transfer paper.

[4] The transfer paper according to [3], wherein the ammonium polyacrylate has a weight average molecular weight of 5000 to 30000 as measured by gel permeation chromatography.

This improves the adhesion of the transfer paper, mainly.

[5] The transfer paper according to any one of the above [1] to [4], wherein at least 1 of the pigments in the outermost coating layer is precipitated calcium carbonate having an average secondary particle diameter of 2 μm or more and 6 μm or less, in which primary particles having an average major axis/average minor axis ratio of 2.0 or more and 7.0 or less are radially aggregated at one end in the major axis direction, and the precipitated calcium carbonate is 80 parts by mass or more based on 100 parts by mass of the pigment in the outermost coating layer.

Thus, the transfer paper can have image deterioration resistance, fogging resistance, strike-through resistance, and ink absorption properties.

[6] The transfer paper according to [5], wherein the air permeability measured on the side provided with the outermost coating layer according to ISO5636-3 is more than 100 ml/min and not more than 320 ml/min.

This improves the strike-through resistance and fogging resistance of the transfer paper.

Effects of the invention

According to the present invention, transfer paper having excellent image deterioration resistance, color development properties, and adhesion can be provided. Further, in a preferred embodiment, transfer paper having fogging resistance, offset resistance, and ink absorbency can be provided.

Detailed Description

The present invention will be described in detail below.

In the present invention, the "transfer paper" refers to paper in a blank state before the pattern to be transferred is printed. The "transfer paper" refers to paper on which a pattern to be transferred is printed.

The transfer paper has a base paper and at least one coating layer of 1 layer on at least one surface of the base paper. In the case of 1 coating layer, the coating layer corresponds to an outermost coating layer containing at least a pigment, a binder, a polyacrylate and an acetylene glycol derivative. When the coating layer has 2 or more layers, the outermost coating layer located outermost based on the base paper contains at least a pigment, a binder, a polyacrylate, and an acetylene glycol derivative. When the coating layer is 2 or more layers, the intermediate coating layer present between the base paper and the outermost coating layer may be any of a coating layer containing a pigment and a binder and a coating layer containing no pigment. When the intermediate coating layer has a pigment, the particle diameter and shape thereof are not particularly limited. Further, the presence or absence of polyacrylate, acetylene glycol, or the like in the intermediate coating layer is not particularly limited.

From the viewpoint of production cost, 1 coating layer is preferable. Further, the base paper may have a coating layer on one side or both sides. When the base paper has the outermost coating layer of the present invention on one surface thereof, the transfer paper may have a conventionally known back coating layer on the back surface thereof.

The coating amount of the coating layer is not particularly limited. The amount of the coating is preferably 2g/m per one-side dry solid content in view of the production cost of transfer paper and the ease of adhesion to a printed matter²Above and 70g/m²The following. The upper limit of the coating amount is more preferably 30g/m²The lower, more preferably 20g/m²The following. Further, the coating amount is most preferably 2g/m per one surface of the substrate from the reasons of reducing the production cost and suppressing the peeling of the coating layer when the substrate is adhered to the substrate²Above and 12g/m²The following. When a plurality of coating layers are present on each surface, the coating amount is the total value of the coating layers.

The base paper is a Pulp paper obtained by pulping a paper stock selected from Mechanical pulps such as LBKP (broad-leaved Bleached Kraft Pulp), NBKP (Needle Bleached Kraft Pulp), GP (ground wood Pulp), PGW (Pressure ground wood Pulp), RMP (disc grinding Mechanical Pulp, Refiner Mechanical Pulp), TMP (thermo Mechanical Pulp), CTMP (chemical thermo Mechanical Pulp), CMP (chemical Mechanical Pulp), CGP (chemical ground wood Pulp), and the like, and DIP (DeInked Pulp) and other waste paper pulps, and further, various fillers such as calcium carbonate, talc, clay, and kaolin, and, if necessary, various additives such as a sizing agent, a fixing agent, a retention aid, a cationizing agent, and a paper strength agent. The base paper also includes high-quality paper obtained by subjecting the pulp paper to a calendering treatment, a surface sizing treatment with starch, polyvinyl alcohol, or the like, or a surface treatment. The base paper also includes high-quality paper subjected to surface sizing treatment and surface treatment and then subjected to calendering treatment.

The paper stock is adjusted to be acidic, neutral or alkaline, and the paper making is performed using a conventionally known paper machine. Examples of the paper machine include a fourdrinier machine, a twin-wire machine, a combination machine, a cylinder machine, and a yankee machine.

The basis weight (plateau amount) of the base paper is not particularly limited. The basis weight of the base paper is preferably 10g/m in view of ease of handling for transfer to a printed material²Above and 100g/m²The lower, more preferably 30g/m²Above 90g/m²The following. The thickness of the transfer paper is not particularly limited. From the viewpoint of ease of handling in transfer to a printed material, the thickness of the transfer paper is preferably 0.01mm or more and 0.5mm or less, and more preferably 0.05mm or more and 0.3mm or less.

The stock may be suitably blended with 1 or 2 or more kinds selected from pigment dispersants, thickeners, fluidity improvers, antifoaming agents, foam inhibitors, mold release agents, foaming agents, penetrants, coloring dyes, coloring pigments, fluorescent brighteners, ultraviolet absorbers, antioxidants, preservatives, mildewproofing agents, water resistance agents, wet paper strength agents, dry paper strength agents, and the like as other additives within a range not to impair the desired effects of the present invention.

The transfer paper has 1 or more coating layers on at least one surface of a base paper. The coating layer may be provided on the base paper by coating and drying the coating layer coating liquid on the base paper.

The method for providing the coating layer on the base paper is not particularly limited. For example, a method of coating and drying using a coating apparatus and a drying apparatus conventionally known in the paper making field can be cited. Examples of the coating apparatus include a size press (sizepress), a gate roll coater, a film transfer coater, a blade coater, a rod coater, an air knife coater, a comma coater, a gravure coater, a bar coater, an E-bar coater, and a curtain coater. Examples of the drying apparatus include various drying apparatuses such as a hot air dryer such as a straight tunnel dryer, an arch dryer, an air loop dryer, and a sinusoidal air dryer, an infrared heating dryer, and a dryer using microwaves.

The outermost coating layer contains at least a pigment, a binder, a polyacrylate and an acetylene glycol derivative.

In the outermost coating layer, the content mass ratio of the pigment to the binder is preferably 20: 80-80: 20. When the specific surface area of the pigment is large, the ratio of the pigment to the binder is preferably 20: 80 to 40: 60, and when the specific surface area of the pigment is small, the ratio of the pigment to the binder is preferably 50: 50 to 80: 20. Here, the BET specific surface area is 150m²At a specific surface area of less than g, the pigment has a small specific surface area of more than 150m in terms of BET specific surface area²The pigment has a large specific surface area per gram.

The content of the polyacrylate in the outermost coating layer is preferably 0.05 parts by mass or more and 1.2 parts by mass or less, and more preferably 0.1 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the total of the pigment and the binder. In addition, in the outermost coating layer, the content of the polyacrylate is preferably 0.1 part by mass or more and 3.5 parts by mass or less with respect to 100 parts by mass of the binder.

The content of the acetylenic diol derivative in the outermost coating layer is preferably 0.1 part by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the total of the pigment and the binder.

In the present invention, the content of the polyacrylate salt of the present invention is not included in the content of the binder.

The pigment of the outermost coating layer is a conventionally known pigment in the field of coated paper, and is not particularly limited. The pigment is preferably a white pigment, and examples of the white pigment include inorganic pigments such as kaolin, heavy calcium carbonate, light calcium carbonate, talc, satin white, lithopone, titanium oxide, zinc oxide, silica, alumina, aluminum hydroxide, activated clay, and diatomaceous earth, and organic pigments such as plastic pigments. The outermost coating layer contains 1 or 2 or more kinds selected from these pigments.

For pigments having a small specific surface area, kaolin and light calcium carbonate are preferable. For pigments with a large specific surface area, silica is preferred.

It is preferable that: at least 1 kind of the pigments of the outermost coating layer is light calcium carbonate having an average secondary particle diameter of 2 to 6 μm, wherein primary particles having an average major axis/average minor axis of 2.0 to 7.0 are radially aggregated at one end in the major axis direction.

Primary particles having an average major axis/average minor axis of 2.0 or more and 7.0 or less have a slender shape and are generally called columnar, acicular, or spindle-shaped particles. The secondary particles are aggregates in which such primary particles are radially aggregated at one end in the longitudinal direction. Light calcium carbonate having an average secondary particle diameter of 2 μm or more and 6 μm or less, in which primary particles having an average major axis/average minor axis of 2.0 or more and 7.0 or less are radially aggregated at one end in the major axis direction, is referred to as "hairy chestnut-like light calcium carbonate", or sea urchin-like light calcium carbonate, or hairy ball-like light calcium carbonate (hereinafter, also referred to as "hairy chestnut-like light calcium carbonate"). For example, light calcium carbonate having the shape shown in Japanese patent application laid-open Nos. 59-94700 and 2015-117437 is mentioned.

Examples of the method for producing light calcium carbonate include a carbon dioxide combination method and a soluble salt reaction method. The carbon dioxide combination method is as follows: a method in which quicklime obtained by burning limestone is dissolved in water to prepare lime milk, and carbon dioxide is reacted with the lime milk to produce light calcium carbonate. The soluble salt reaction method is as follows: a process for producing light calcium carbonate by reacting a calcium chloride solution with sodium carbonate in a milk of lime. The crystal system, size and shape of the precipitated calcium carbonate can be adjusted by using the reaction conditions. As the crystal system of the light calcium carbonate, there are calcite crystal, aragonite crystal, and the like. The calcite crystal is generally in the form of a spindle, a form in which spindle-shaped particles are aggregated and bound, a cube (including a cluster with inconspicuous edges) or a form in which cube-shaped particles are aggregated and bound. The shape of the aragonite crystal is generally columnar, needle-like, or a shape in which they are aggregated. Such light calcium carbonate is sold, for example, by whitlockite, odomol industries, and the like.

The chestnut-like light calcium carbonate is preferably aragonite-based crystals. The reason for this is because the ink absorbency or fogging resistance is improved.

The content of the chestnut-like light calcium carbonate having an average secondary particle diameter of 2 μm or more and 6 μm or less, in which primary particles having an average major axis/average minor axis of 2.0 or more and 7.0 or less are radially aggregated at one end in the major axis direction, in the outermost coating layer is preferably 80 parts by mass or more with respect to 100 parts by mass of the pigment in the outermost coating layer. The content is more preferably 85 parts by mass or more, and still more preferably 90 parts by mass or more, to 100 parts by mass of the pigment in the outermost coating layer. The reason for this is because the fogging resistance, the offset resistance, or the ink absorbency is further improved.

The average minor axis and the average major axis of the primary particles of the light calcium carbonate, and the shape and the average secondary particle diameter of the secondary particles can be determined by image analysis from a scanning electron micrograph of the outermost coating layer. The average short diameter and the average long diameter of the primary particles can be calculated by taking an electron microscope photograph using a scanning electron microscope, and observing and actually measuring 100 primary particles of which the shapes can be confirmed from the taken images. The average secondary particle size can be calculated by taking an electron microscope photograph using a scanning electron microscope, and calculating the particle size from the taken image by regarding any 100 secondary particles as a sphere whose projected area of the particles is approximate.

The binder of the outermost coating layer is a conventionally known binder, and is not particularly limited. However, in the present invention, the polyacrylate is not included in the conventionally known binders. Examples of the conventionally known adhesive include natural polymer resins such as starch, various modified starches, carboxymethylcellulose, and hydroxyethylcellulose, casein, gelatin, soybean protein, pullulan (pullulan), gum arabic, karaya gum, and albumin, and derivatives thereof, polyvinylpyrrolidone, polyvinyl alcohol, various modified polyvinyl alcohols, polyacrylamide, polyethyleneimine, polypropylene glycol, polyethylene glycol, maleic anhydride resin, acrylic resin, methacrylate-butadiene copolymer, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, or functional group-modified copolymer of the various copolymers based on a monomer having a functional group such as a carboxyl group, a binder such as melamine resin, and thermosetting synthetic resin such as urea resin, a binder such as melamine resin, and a binder such as a thermosetting synthetic resin, a binder such as a cellulose derivative such as starch, carboxymethylcellulose, and hydroxyethylcellulose, a binder such as polyvinyl pyrrolidone, polyvinyl alcohol, a polyacrylamide, a polyvinyl imine, a polypropylene glycol, a polyethylene glycol, a maleic anhydride resin, an acrylic resin, a methacrylate-butadiene copolymer, a styrene-butadiene copolymer, and a copolymer, Polyurethane resins, unsaturated polyester resins, polyvinyl butyral, alkyd resin latexes, and the like. The outermost coating layer contains 1 or 2 or more kinds selected from these binders.

The polyacrylate of the outermost coating layer contains 1 or 2 or more species of structural units derived from an acrylate represented by the following general formula, and is a homopolymer or a copolymer, or a copolymer containing other structural units as required. The polyacrylate salt of the present invention is preferably a polymer in which 50 mol% or more of the whole is occupied by structural units derived from an acrylate salt represented by the following general formula.

[ solution 1]

In the above general formula, M is Na, K or NH₄。

The polyacrylate salt is preferably ammonium polyacrylate. This is because the image deterioration resistance is particularly improved.

The weight average molecular weight of ammonium polyacrylate measured by gel permeation chromatography is preferably in the range of 1500 or more and 50000 or less, more preferably 5000 or more and 30000 or less. The reason for this is that the adhesion is improved. It can be considered that: ammonium polyacrylate having a weight average molecular weight of 1500 or more and 50000 or less is excellent as a protective colloid for a pigment, and therefore the flexibility of the outermost coating layer is increased. As a result, the adhesion is improved. It can be considered that: when the weight average molecular weight is less than 1500, the protective colloid is insufficient, and when it exceeds 50000, flexibility is difficult to obtain.

The weight average molecular weight of the present invention is a polyethylene glycol equivalent value of gel permeation chromatography.

The acetylene glycol derivative of the outermost coating layer is a compound represented by the following general formula (1) or (2).

[ solution 2]

R in the above general formula (1)₁、R₂、R₃And R₄Each represents an alkyl group having 1 to 5 carbon atoms. R₁、R₂、R₃And R₄Preferably, the structure is bilaterally symmetric about the ethynyl group.

[ solution 3]

R in the above general formula (2)₅、R₆、R₇And R₈Each represents a carbon number of 1 or moreAnd 5 or less alkyl groups. m and n are each an integer of 1 to 25 inclusive, and m + n is 2 to 40 inclusive. OE is ethylene oxide chain (-O-CH)₂-CH₂-) OP is an oxypropylene chain (-O-CH)₂-CH[CH₃]-). OE and OP may be a single chain or a mixed chain. R₅、R₆、R₇And R₈Preferably, the structure is bilaterally symmetric about the ethynyl group.

The alkynediol derivative is sold by Nissan chemical industries under the name "Surfynol (registered trademark)" or "Olfine (registered trademark)", and is sold by Kawaken Fine Chemicals Co., Ltd. under the name "acetolene (registered trademark)".

In the present invention, the alkynediol derivative is preferably 2, 4, 7, 9-tetramethyl-5-decyne-4, 7-diol or an ethoxylate of 2, 4, 7, 9-tetramethyl-5-decyne-4, 7-diol. The reason for this is because it is commercially available.

The outermost coating layer may contain, in addition to the polyacrylate and the acetylene glycol derivative, various additives known in the art of coated paper as needed. Examples of the additives include dispersants, fixatives, thickeners, fluidity improvers, antifoaming agents, mold release agents, foaming agents, penetrants, coloring pigments, coloring dyes, fluorescent brighteners, ultraviolet absorbers, antioxidants, preservatives, and mildewcides.

The outermost coating layer may contain various additives conventionally known in the transfer printing method. The auxiliary agent is added for optimizing various physical properties of the outermost coating layer coating liquid, improving the staining property of the transferred sublimation type printing ink, or the like. Examples of the auxiliary agent include various surfactants, humectants, wetting agents, pH regulators, alkalizers, deep dyeing agents, deaerators, and anti-reducing agents.

It is preferable that: the transfer paper of the present invention has an air permeability, as determined by ISO5636-3, of more than 100 ml/min and not more than 320 ml/min, as measured on the side provided with the outermost coating layer.

In general, the above air permeability of the base paper is a very high value compared with the air permeability of the coated paper having the coating layer provided on the base paper. The reason for this is because the components of the coating layer block the voids of the pulp fibers constituting the base paper. Therefore, the air permeability of the coated paper can be usually adjusted by the coating layer.

The air permeability of the coated paper is a physical property value known in the field of coated paper, and can be adjusted by the size and shape of the pigment of the coating layer, the content of the pigment, the type and content of the binder, and the like. A particularly effective adjustment method is a method of adjusting the coating amount of the coating layer, the presence or absence of rolling treatment, and the conditions thereof. By controlling the rolling conditions such as the temperature of the reduction rolls, the pressure in the reduction nip, and the time in the reduction nip, a desired air permeability can be obtained.

The transfer paper of the present invention can be adjusted in air permeability in the same manner as the above-mentioned ordinary coated paper.

The transfer paper can be obtained by printing a pattern on the surface of the transfer paper having the outermost coating layer using various conventionally known printing methods including sublimation type printing ink.

Various printing methods for printing a pattern on transfer paper are conventionally known printing methods, and are not particularly limited. Examples of the printing method include a gravure printing method, an inkjet printing method, an electrophotographic printing method, and a screen printing method. Among them, the inkjet printing method is preferable in terms of high definition of image quality and miniaturization of the apparatus.

A transfer printing method using sublimation printing ink includes a step of obtaining a transfer paper by printing a pattern on transfer paper, and a step of bringing the transfer paper into close contact with an object to be printed. The step of bonding includes heating and pressing as necessary. The conditions of heating and pressurizing in the step of adhesion are conventionally known conditions in the transfer printing method. Examples of the step of bonding include a method of bonding the transfer paper to the object to be printed by a press, a heating roller, or the like, and heating and pressing the transfer paper.

The material to be printed is a fibrous material, and is not particularly limited. The fiber material may be any of natural fiber materials and synthetic fiber materials. Examples of the natural fiber material include cellulose fiber materials such as cotton, hemp, Lyocell (Lyocell), rayon, and acetate, and protein fiber materials such as silk, wool, and animal hair. Examples of the synthetic fiber material include polyamide fiber (nylon), vinylon, polyester, and polyacrylic. Examples of the structure of the fiber material include woven fabric, knitted fabric, nonwoven fabric, and the like, which are woven fabric, blended fabric, mixed fabric, or woven fabric. Further, these components may be combined. In addition, the object to be printed may be pretreated with a chemical agent or the like effective for promoting staining, as necessary.

In the transfer printing method using the sublimation printing ink, the material to be printed is preferably a synthetic fiber material. Natural fiber materials mostly require pretreatment.

Examples

The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. Here, "parts by mass" and "% by mass" represent "parts by mass" and "% by mass" of the dry solid content or the essential component content, respectively. The coating amount of the coating layer indicates the amount of the dry solid component.

< base paper >

To 100 parts by mass of LBKP pulp containing 380mlcsf of drainage degree, 10 parts by mass of calcium carbonate, 1.2 parts by mass of amphoteric starch, 0.8 part by mass of aluminum sulfate and 0.1 part by mass of alkyl ketene dimer sizing agent were added as fillers, and papermaking was carried out using a fourdrinier papermaking machine, and oxidized starch was added in an amount of 1.5g/m per one side using a size press²Adhered to both sides, mechanically rolled to give a basis weight of 62g/m²The base paper of (1).

< outermost coating layer coating liquid >

For the outermost coating layer coating liquid, the materials described in table 1 were used and mixed and dispersed in water to prepare.

The amounts of the respective materials in the outermost coating layer coating liquid are also shown in table 1.

In Table 1, Silica A is NIPGEL (registered trademark) AY-200 manufactured by Tosoh Silica Corporation. The silica B was MIZUKASIL (registered trade name) P-527, manufactured by Shuizzihua chemical industries, Ltd. The light calcium carbonate was TamaPearl (registered trademark) TP221F (calcite crystal, average major axis/average minor axis of 2.0, no secondary particle formed) manufactured by ondol industries. The alkynediol derivative A is Surfynol 104E (structure of the general formula (1)) manufactured by Nissan chemical industries. The alkynediol derivative B is Olfine E1010 (structure of the general formula (2)) manufactured by Nissan chemical industries. The alkynol is Olfine B manufactured by Nissan chemical industry Co. For ammonium polyacrylate, except for examples 24 and 25, ammonium polyacrylate having a weight average molecular weight of about 22000 as determined by gel permeation chromatography was used. The ammonium polyacrylates of examples 24 and 25 used ammonium polyacrylate having a weight average molecular weight of about 6000 as determined by gel permeation chromatography.

< transfer paper >

Transfer paper was produced according to the following procedure.

The outermost coating layer coating liquid was applied to one side of the base paper by an air knife coater, dried by a hot air dryer, and then subjected to a calendering treatment to obtain a transfer paper. The coating amount is shown in Table 1.

[ Table 1]

TABLE 1

The "polyacrylate content by mass ratio" in table 1 is a content of polyacrylate with respect to 100 parts by mass of the binder in the outermost coating layer.

< production of transfer paper >

The transfer paper obtained was printed with an evaluation pattern based on sublimation printing ink (cyan, magenta, and yellow) using an inkjet printer (JV2-130II, MIMAKI ENGINEERING co., ltd.) using sublimation printing ink, to obtain transfer paper.

< printing (cutting paper) >

Polyester cloth was used as the material to be printed. The transfer paper thus obtained was closely adhered to a polyester cloth, and heated at 200 ℃ for 1 minute using a thermal transfer press (manual wide oscillator Model221, manufactured by INSTA) to transfer the dye to the polyester cloth. Thereafter, the transfer paper was peeled off from the polyester cloth to obtain a polyester cloth with a pattern.

< evaluation of resistance to image degradation >

For the polyester cloth formed with a pattern, the image deterioration resistance was evaluated in terms of the clarity of the pattern, and the image quality was evaluated in a sensory manner according to the following criteria. In the present invention, the transfer paper was evaluated as having image deterioration resistance at A, B or C.

A: good level.

B: almost no deterioration in image quality was observed, and the level was almost good.

C: deterioration in image quality was observed, but there was no practical problem level.

D: a level of image degradation that was practically impossible was observed.

< evaluation of color development >

Color density was measured for solid image portions of 3 colors (cyan, magenta, and yellow) of sublimation printing ink of a print target using an optical density meter (X-rite530, SAKATA INX eng.co., ltd., inc., and the color density values of the 3 colors were added. Color development was judged according to the following criteria. In the present invention, when the transfer paper is evaluated as A or B, it is said that the color developability is good.

A: a total value of 4.7 or more

B: a total value of 4.4 or more and less than 4.7

C: the total value is less than 4.4

< printing and dyeing (roll paper) >

As the object to be printed, a roll-shaped polyester cloth was used. The transfer paper in roll form thus obtained was closely adhered to a polyester cloth, and the dye was transferred to the polyester cloth by using a heating and pressing machine (200 ℃, 0.5MPa, 2.5 m/min, roll, contact time with roll 30 seconds). Thereafter, the transfer paper was peeled off from the polyester cloth to obtain a polyester cloth with a pattern formed.

< evaluation of adhesion >

For the polyester cloth formed with a pattern, the adhesion was evaluated by sensory evaluation according to the following criteria, in terms of the degree of occurrence of blurring and distortion of the pattern. In the present invention, when the transfer paper is evaluated as a or B, it is said that the adhesiveness is excellent.

A: no blur, distortion, good level was observed.

B: almost no blur or distortion was observed, and the level was almost good.

C: blurring, distortion, was observed, but there was no problem level in practical use.

D: blurring, distortion, and a practically problematic level were observed.

The evaluation results are also shown in Table 1.

From the evaluation results in table 1, it is found that: examples 1 to 25, which are transfer papers having an outermost coating layer containing a pigment, a binder, a polyacrylate and an alkynediol derivative, have image deterioration resistance, color development properties and adhesion. However, it can be seen that: in comparative examples 1 to 10, which do not belong to the above transfer paper, any of the image deterioration resistance, the color development property, and the adhesion property cannot be satisfied.

From the comparison of the main examples 4 to 6 and 14 to 16 with the main examples 11 and 23: in the outermost coating layer, the content of the polyacrylate with respect to 100 parts by mass of the binder is preferably in the range of 0.1 part by mass or more and 3.5 parts by mass or less.

From a comparison of the main examples 4 and 14, and the main examples 7 and 17: the polyacrylate salt is preferably ammonium polyacrylate.

From examples 1 to 23 having a weight average molecular weight of about 22000 measured by gel permeation chromatography and examples 24 and 25 having a weight average molecular weight of about 6000, it can be seen that: the weight average molecular weight of the ammonium polyacrylate is preferably 5000 to 30000.

Next, an outermost coating layer coating liquid described below was prepared.

< outermost coating layer coating liquid >

For the outermost coating layer coating liquid, the materials described in table 2 were used and mixed and dispersed in water to prepare.

The amounts of the respective materials in the outermost coating layer coating liquid are also shown in table 2.

[ Table 2]

TABLE 2

In table 2, the materials used are shown below.

Light calcium carbonate of examples 26 to 36:

callite (registered trademark) SA manufactured by Baishi calcium Co Ltd

Aragonite crystal

Average major axis/average minor axis is 6.5

Has an average secondary particle diameter of 3.3 μm and a hairy chestnut shape

Calcium carbonate of example 37:

TamaPearl TP-121SA manufactured by Ordomo industries Ltd

Calcite-based crystal

Average major axis/average minor axis is 4.0

Has an average secondary particle diameter of 3.5 μm and a hairy chestnut shape

Light calcium carbonate of examples 38 and 39:

TamaPearl TP-221BM manufactured by Ottoman industries Ltd

Calcite-based crystal

Average major axis/average minor axis is 3.0

Has an average secondary particle diameter of 4.0 μm and a hairy chestnut shape

Light calcium carbonate of example 40:

TamaPearl TP-121S manufactured by Ordomo industries Ltd

Calcite-based crystal

Average major axis/average minor axis is 4.0

Has an average secondary particle diameter of 4.3 μm and a hairy chestnut shape

Light calcium carbonate of example 41:

TamaPearlTP-121MS, manufactured by Ordomo industries Ltd

Calcite-based crystal

Average major axis/average minor axis is 3.0

Has an average secondary particle diameter of 2.3 μm and a hairy chestnut shape

Light calcium carbonate of example 42:

tunex (registered trademark) E manufactured by Baishi calcium Co

Calcite-based crystal

Average major axis/average minor axis is 3.0

Has an average secondary particle diameter of 5.6 μm and a hairy chestnut shape

Light calcium carbonate of examples 43 and 44:

callite KT manufactured by Baishi calcium Co Ltd

Aragonite crystal

Average major axis/average minor axis is 6.7

Has an average secondary particle diameter of 2.6 μm and a hairy chestnut shape

Light calcium carbonate of examples 45 and 46:

CalliteSA, CalliteSA

Aragonite crystal

Average major axis/average minor axis is 6.5

Kaolin for examples 45 and 46:

HG90 manufactured by ヒューバー Co

Average particle diameter of 0.19. mu.m

Light calcium carbonate of example 47:

CalliteSA, CalliteSA

Aragonite crystal

Average major axis/average minor axis is 6.5

Silica of example 47:

finesil (registered trademark) X-37 manufactured by Oriental Silicas Corporation

Average particle diameter of 2.6. mu.m

Light calcium carbonate of example 48

Callite (registered trademark) SA manufactured by Baishi calcium Co Ltd

Aragonite crystal

Average major axis/average minor axis is 6.5

< transfer paper >

Transfer paper was produced according to the following procedure.

The outermost coating layer coating liquid was applied to one side of the base paper by an air knife coater, dried by a hot air dryer, and then subjected to a calendering treatment to obtain a transfer paper. The air permeability of the transfer paper is adjusted by the coating amount and/or the calendering conditions. The coating amounts are shown in Table 2.

< production of transfer paper >

An evaluation pattern based on the sublimation printing ink (cyan, magenta, yellow, and black) was printed on the obtained transfer paper using an inkjet printer (JV2-130II, MIMAKI ENGINEERING co., ltd) using the sublimation printing ink, to obtain transfer paper (roll paper).

< evaluation of offset resistance >

The transfer paper obtained as described above was subjected to sensory evaluation for strike-through resistance according to the following criteria, in accordance with the degree of visibility of an image from the back surface of the transfer paper. In the present invention, it is said that the transfer paper has offset resistance when evaluated as A or B.

A: show through is hardly observed, good level.

B: strike-through was slightly observed, but the subsequent transfer was at a level that was not problematic in practice.

C: strike-through is observed, and subsequent transfer becomes a level of practical problem.

< evaluation of ink absorbency >

After the transfer paper obtained as described above was left to stand at 23+1 ℃ and 50+ 2% RH for 5 hours, the printed matter near the core of the roll paper was subjected to sensory evaluation for each color outline portion and hollow character portion according to the following criteria. In the present invention, it is said that the transfer paper has ink absorbability when evaluated as a or B.

A: no penetration was observed in the outline portion and the hollow character of each color by microscopic observation (X25).

B: slight penetration was observed in each color outline and hollow character by microscopic observation (magnification × 25).

Visual observation made it difficult to confirm the result, and there was no problem in actual use.

C: the color outline and the hollow character were observed by microscopic observation (X25).

It is also slightly observed by visual observation, and actually becomes a problem in use.

D: the penetration was observed at the outline portions and the hollow-out letters of the respective colors by visual observation.

< printing and dyeing (roll paper) >

< evaluation of resistance to image degradation >

For the polyester cloth formed with a pattern, the image quality was evaluated in terms of the clarity of the pattern and the image deterioration resistance according to the following criteria. In the present invention, the transfer paper was evaluated as having image deterioration resistance at A, B or C.

A: good level.

D: a level of image degradation that was practically impossible was observed.

< evaluation of fogging resistance >

The fogging resistance was evaluated by visually confirming the presence or absence of blotches on the printed matter with a magnifying glass and according to the following criteria. In the present invention, the transfer paper was evaluated as a or B, and it was found that the fogging resistance was good.

A: no spot staining was observed by magnifying glass, good level.

B: no spot staining was visually observed, approximately good level.

C: the practical lower limit level of the stain was visually observed, which did not cause any trouble.

D: the level of the stain which was a defect was visually observed, and was not practically possible.

The evaluation results are shown in table 2.

The evaluation results in table 2 show that: examples 26 to 48, which are transfer papers wherein at least 1 of the pigments belonging to the outermost coating layer is precipitated calcium carbonate having an average secondary particle diameter of 2 μm or more and 6 μm or less in which primary particles having an average major axis/average minor axis ratio of 2.0 or more and 7.0 or less are radially aggregated at one end in the major axis direction, and the precipitated calcium carbonate is 80 parts by mass or more relative to 100 parts by mass of the pigment in the outermost coating layer, have image deterioration resistance, fogging resistance, strike-through resistance, and ink absorption properties.

Mainly from the comparison of examples 26, 27, 29 to 31, 34, 35 and 48 with examples 28, 32, 33 and 36: the transfer paper preferably has an air permeability of more than 100 ml/min and not more than 320 ml/min.

Industrial applicability

The transfer paper of the present invention is useful as all of the following items.

(4) Can inhibit the printed matter from fogging (fogging resistance)

Claims

1. A transfer paper for use in a transfer printing method using a sublimation printing ink, the transfer paper having a base paper and at least one coating layer on at least one surface of the base paper, the outermost coating layer located outermost with respect to the base paper containing a pigment, a binder other than polyacrylate, and an acetylenic diol derivative,

in the outermost coating layer, the polyacrylate salt is 0.1 part by mass or more and 1 part by mass or less with respect to 100 parts by mass of the total of the pigment and the binder excluding the polyacrylate salt,

the polyacrylate is ammonium polyacrylate.

2. The transfer paper according to claim 1, wherein the polyacrylate salt is contained in an outermost coating layer in an amount of 0.1 parts by mass or more and 3.5 parts by mass or less with respect to 100 parts by mass of the binder.

3. The transfer paper according to claim 1, wherein the ammonium polyacrylate has a weight average molecular weight of 5000 or more and 30000 or less as measured by gel permeation chromatography.

4. The transfer paper according to claim 1 or 2, wherein at least 1 of the pigments in the outermost coating layer is precipitated calcium carbonate having an average secondary particle diameter of 2 μm or more and 6 μm or less, in which primary particles having an average major axis/average minor axis ratio of 2.0 or more and 7.0 or less are radially aggregated at one end in the major axis direction, and the precipitated calcium carbonate is 80 parts by mass or more with respect to 100 parts by mass of the pigment in the outermost coating layer.

5. The transfer paper according to claim 3, wherein at least 1 of the pigments in the outermost coating layer is precipitated calcium carbonate having an average secondary particle diameter of 2 μm or more and 6 μm or less, in which primary particles having an average major axis/average minor axis ratio of 2.0 or more and 7.0 or less are radially aggregated at one end in the major axis direction, and the precipitated calcium carbonate is 80 parts by mass or more with respect to 100 parts by mass of the pigment in the outermost coating layer.

6. The transfer paper according to claim 4, wherein the air permeability measured on the side provided with the outermost coating layer according to ISO5636-3 is more than 100 ml/min and not more than 320 ml/min.

7. The transfer paper according to claim 5, wherein the air permeability measured on the side provided with the outermost coating layer according to ISO5636-3 is more than 100 ml/min and not more than 320 ml/min.