WO2018061376A1

WO2018061376A1 - Transfer paper

Info

Publication number: WO2018061376A1
Application number: PCT/JP2017/024376
Authority: WO
Inventors: 宏二五十嵐; 淳浦崎
Original assignee: 三菱製紙株式会社
Priority date: 2016-09-29
Filing date: 2017-07-03
Publication date: 2018-04-05
Also published as: CN109844216A; CN109844216B

Abstract

Provided is transfer paper, which has base paper and one or more coating layers on at least one surface of the base paper, the outermost coating layer positioned outermost with the base paper as the reference including at least a pigment, a binder, a polyacrylate, and an acetylene glycol derivative, and which is used in a transfer printing method using sublimation printing ink. Thus, the transfer paper has anti-image degradation properties, excellent chromogenic properties, and superior adhesion.

Description

Transfer paper

The present invention relates to a transfer paper used for transferring a pattern in a transfer printing method for forming a pattern on a substrate such as a fiber material.

As a method of forming a pattern on a printed material such as a textile material, a pattern is printed on a transfer paper using sublimation printing ink to produce a transfer paper, the transfer paper is brought into close contact with the printed material, and the sublimation printing ink is used. A transfer textile printing method for transferring to a substrate is known (see, for example, Patent Document 1 and Patent Document 2).

Transfer paper used for transfer textile printing is known.
For example, a sheet-like substrate can be used as a sublimation transfer sheet that is excellent in water-based ink absorptivity and capable of obtaining a clear recorded image without bleeding and excellent in ink transfer efficiency to a transfer object during sublimation transfer. Material and an ink receiving layer provided on one or both sides of the sheet-like base material, and the ink receiving layer contains a pigment, a binder, and a cationic resin, and precipitated silica is used as the pigment. In addition, as the binder, a sublimation transfer sheet is known in which any one of starch, starch derivatives, polyvinyl alcohol, modified polyvinyl alcohol or a mixture of two or more thereof is used (for example, And Patent Document 3).
In addition, it has a sublimation printing ink receiving layer on a substrate as a sublimation printing type transfer paper that has excellent ink drying properties and anti-through-through properties, and also has good properties in terms of transfer image reproducibility and transfer efficiency. A sublimation printing type transfer paper, wherein the sublimation printing ink receiving layer comprises a water-soluble resin and fine particles dispersed as a main component, a nonionic surfactant, and a surface of the sublimation printing ink receiving layer. Sublimation printing type transfer paper characterized by forming irregularities is known (see, for example, Patent Document 4).
Sublimation with excellent absorption and drying properties of sublimation printing inks for inkjet printing, excellent image reproducibility and prevention of back-through, and excellent transfer efficiency for transfer printing to transferred materials Sublimation type printing ink receiving layer is formed on a substrate as a type inkjet printing transfer paper, the substrate has a water absorption of 5 to 20 g / m ² for 10 seconds, and the sublimation printing ink receiving layer is made of a water-soluble resin and a fine layer. A water-soluble resin is at least carboxymethylcellulose, and the ink-receiving layer coating contains 100 to 400 parts by mass of carboxymethylcellulose with respect to 100 parts by mass of fine particles. Is an inorganic fine particle having at least a plate crystal structure. The inorganic fine particle has a median diameter d50 of 0.4 to 2.3 μm, an aspect ratio of 5 to 30, and an ink receiving layer. The coating amount of the fee is 3 ~ 13g / m ^2, sublimation inkjet printing transfer paper Average pinhole expression number is 5 or less are known (e.g., see Patent Document 5).
Further, a transfer paper suitable for ink jet printing, which has a release or barrier layer and has a maximum porosity of 100 ml / min, is known (for example, see Patent Document 6).

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

JP2015-168705A JP2015-124324A JP 2010-158875 A JP 2009-131958 A Japanese Patent Application Laid-Open No. 2016-155943 Special Table 2002-521245

The transfer paper, which is a white paper before the design is printed, and the transfer paper obtained by printing the design on the transfer paper must have two characteristics that are contradictory to each other. That is, the transfer paper is required to have an ability to successfully receive the sublimation type printing ink, and the transfer paper is required to have an ability to transfer the sublimation type printing ink onto the substrate.
Since the transfer paper becomes a transfer paper having a sharp image so as not to deteriorate the image quality of the pattern formed on the substrate, it is necessary to improve the acceptability for the sublimation type printing ink. Furthermore, the transfer paper must not deteriorate the image quality of the pattern formed on the substrate from the transfer paper having a sharp image.
On the other hand, when the transfer paper has improved acceptability of the transfer paper with respect to the sublimation printing ink, the transfer of the sublimation printing ink may be insufficient at the time of transfer for forming a pattern on the substrate. As a result, the color developability of the substrate is reduced.

Further, since the transfer is performed by bringing the transfer paper and the printing material into close contact with each other, the transfer paper must be able to make good contact with the printing material. In addition to the above-described deterioration in image quality during image formation, there is a problem of image quality that occurs because the transfer paper and the printing material do not adhere well. In a region where the transfer paper and the printing material are not in close contact with each other, image blurring or distortion occurs.
In the case of continuously transferring to a printing material, the transfer is performed by bringing the roll paper-like transfer paper and the printing material into close contact with each other. In particular, in order to proceed the transfer continuously, it is more important that the transfer paper is in close contact with the substrate.

Also, in the transfer textile printing method, there is fogging as a problem of image quality different from the deterioration of the image quality of the pattern formed on the printed material. The fog is a phenomenon in which sublimation-type printing ink is sublimated and transferred to a region different from a pattern when the sublimation-type printing ink is transferred from a transfer paper to a substrate. Typically, this is a phenomenon in which spotted stains occur on a white background. Although a method for suppressing fogging by the technique of sublimation type printing ink has been studied, a method for suppressing fogging by transfer paper is also required.

Also, in order to satisfactorily transfer the sublimation printing ink from the transfer paper to the printing material, the transfer paper needs to be received without penetrating the sublimation printing ink to the deep part of the paper. That is, the transfer paper is required to suppress the back-through. “Back-through” is a phenomenon in which sublimation dye ink of an image printed on a transfer paper penetrates to the depth of the paper.

Also, an ink jet printing method is often adopted as a method for producing a transfer paper by printing a design on a transfer paper. In the ink jet printing system, transfer paper and transfer paper are often handled by roll paper, and in the roll paper state, evaporation of the ink solvent tends to be delayed. There is a demand for a transfer paper that can absorb the sublimation printing ink so that it does not exude before the ink solvent evaporates on the transfer paper wound up in a roll after printing.

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 type ink jet printing transfer paper of Patent Document 6 is not necessarily sufficient. Improvement is desired for the transfer paper to adhere well to the substrate or to suppress fogging.

In view of the above, an object of the present invention is to provide a transfer paper that satisfies the following items.
(1) Image degradation can be suppressed on the substrate (image degradation resistance)
(2) The ability to suppress a decrease in color development on the substrate (color development)
(3) The transfer paper and the substrate to be in good contact (adhesion)

Furthermore, in a preferred embodiment, a transfer sheet satisfying the following items is provided.
(4) Suppression of fogging on printed materials (fogging resistance)
(5) Suppression of back-through on transfer paper (anti-through-through resistance)
(6) The ink can be absorbed so that the ink does not ooze out on the transfer paper (ink absorbability).

As a result of intensive studies to solve the above problems, the inventors of the present invention can achieve the object of the present invention as follows.

[1] A base paper and one or more coating layers on at least one side of the base paper, and the outermost coating layer located on the outermost side with respect to the base paper is a pigment, a binder, a polyacrylate, and acetylene A transfer paper used in a transfer printing method using a sublimation printing ink, which contains at least a glycol derivative.
As a result, the transfer paper can obtain image deterioration resistance, color developability and adhesion.

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

[3] The transfer paper according to [1] or [2], wherein the polyacrylate is ammonium polyacrylate.
As a result, the transfer paper has improved image deterioration resistance.

[4] The transfer paper according to [3], wherein the weight average molecular weight of the ammonium polyacrylate measured by a gel permeation chromatography method is 5000 or more and 30000 or less.
Thereby, the transfer paper mainly improves the adhesion.

[5] At least one of the pigments in the outermost coating layer has primary particles having an average major axis / average minor axis ratio of 2.0 or more and 7.0 or less, which are aggregated radially at one end in the major axis direction. [1] to [1], wherein the light calcium carbonate has an average secondary particle diameter of 2 μm or more and 6 μm or less, and the light calcium carbonate is 80 parts by mass or more with respect to 100 parts by mass of the pigment in the outermost coating layer. 4]. The transfer paper according to any one of [4].
As a result, the transfer paper can obtain image deterioration resistance, fog resistance, anti-through-through resistance, and ink absorbability.

[6] The transfer paper according to [5], wherein the air permeability required in accordance with ISO 5636-3 obtained by measuring the side provided with the outermost coating layer is more than 100 ml / min and not more than 320 ml / min. .
As a result, the transfer paper has improved anti-through-through or anti-fogging properties.

According to the present invention, it is possible to provide a transfer paper excellent in image deterioration resistance, color development and adhesion. Furthermore, in a preferred embodiment, it is possible to provide a transfer paper having anti-fogging properties, anti-penetration resistance and ink absorbability.

The present invention is described in detail below.
In the present invention, the “transfer sheet” refers to a sheet in a blank state before a pattern to be transferred is printed. “Transfer paper” refers to paper on which a pattern to be transferred to the transfer paper is printed.

The transfer paper has a base paper and one or more coating layers on at least one side of the base paper. When the coating layer is one layer, the coating layer corresponds to the outermost coating layer, and the outermost coating layer contains at least a pigment, a binder, a polyacrylate, and an acetylene glycol derivative. When there are two or more coating layers, the outermost coating layer located on the outermost side with respect to the base paper contains at least a pigment, a binder, a polyacrylate, and an acetylene glycol derivative. When there are two or more coating layers, the intermediate coating layer existing between the base paper and the outermost coating layer is either a coating layer containing a pigment and a binder or a coating layer containing no pigment. There may be. Further, when the intermediate coating layer has a pigment, the particle diameter and shape thereof are not particularly limited. Furthermore, the presence or absence of polyacrylate or acetylene glycol in the intermediate coating layer is not particularly limited.
From the viewpoint of production cost, one coating layer is preferable. The coating layer may be provided on one side or both sides of the base paper. When the outermost coating layer according to the present invention is provided on one side of the base paper, the transfer paper may have a conventionally known back coat layer on the back side of the base paper.

The coating amount of the coating layer is not particularly limited. Terms easily brought into close contact against the manufacturing cost and the substrate of the transfer sheet, the coating weight is preferably 2 g / m ² or more 70 g / m ² or less per side dry solid content. The upper limit is more preferably 30 g / ^{m 2} or less of coating weight, 20 g / ^{m 2} or less is more preferred. Furthermore, for the reason that it is possible to prevent the coating layer is lost during the adhesion and the manufacturing cost and the substrate, the coating weight is per side 2 g / m ² or more 12 g / m ² or less is most preferred. When there are a plurality of coating layers on one side, the coating amount is a total value thereof.

Base paper is chemical pulp such as LBKP (Leaf Bleached Kraft Pulp), NBKP (Needle Bleached Kraft Pulp), GP (Groundwood Pulp), PGW (Pressure GroundWood pulp), RMP (Refiner Mechanical Pulp), TMP (Refiner Mechanical Pulp), TMP (ChemiThermoMechanical Pulp), CMP (ChemiMechanical Pulp), mechanical pulp such as CGP (ChemiGroundwood Pulp), and at least one pulp selected from waste paper pulp such as DIP (DeInked Pulp), calcium carbonate, talc, clay, kaolin, etc. In addition, various types of fillers, and further, papers made from papers containing various additives such as sizing agents, fixing agents, retention agents, cationizing agents, and paper strength agents as necessary. Further, the base paper includes high-quality paper obtained by subjecting papermaking paper to calendar treatment, surface sizing treatment with starch or polyvinyl alcohol, or the like. Furthermore, the base paper includes high-quality paper that has been subjected to surface sizing or surface treatment and then calendered.

Paper making is performed using a conventionally known paper machine by adjusting the stock to acid, neutral or alkaline. Examples of the paper machine include a long net paper machine, a twin wire paper machine, a combination paper machine, a circular net paper machine, and a Yankee paper machine.

The basis weight of the base paper is not particularly limited. The basis weight of the base paper is preferably 10 g / m ² or more and 100 g / m ² or less, and more preferably 30 g / m ² or more and 90 g / m ² or less from the viewpoint of easy handling with respect to transfer to the printing material. Further, the thickness of the transfer paper is not particularly limited. From the viewpoint of easy handling with respect to the transfer to the printing material, the thickness of the transfer paper is preferably 0.01 mm or more and 0.5 mm or less, and more preferably 0.05 mm or more and 0.3 mm or less.

In paper stock, other additives include pigment dispersants, thickeners, fluidity improvers, antifoaming agents, antifoaming agents, mold release agents, foaming agents, penetrating agents, colored dyes, colored pigments, fluorescent enhancers. One or more selected from a whitening agent, an ultraviolet absorber, an antioxidant, an antiseptic, an antibacterial agent, a water resistant agent, a wet paper strength enhancer, a dry paper strength enhancer, and the like according to the present invention. It can mix | blend suitably in the range which does not impair an effect.

The transfer paper has one or more coating layers on at least one side of the base paper. The coating layer can be provided on the base paper by applying and drying a coating layer coating solution on the base paper.
The method for providing the coating layer on the base paper is not particularly limited. Examples thereof include a method of coating and drying using a conventionally known coating apparatus and drying apparatus in the papermaking field. Examples of the coating apparatus include a size press, 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 dryers include various dryers such as straight tunnel dryers, arch dryers, air loop dryers, sine curve air float dryers, hot air dryers, infrared heating dryers, dryers using microwaves, etc. Can do.

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 ratio of pigment to binder is preferably pigment: binder = 20: 80 to 80:20. Further, when the specific surface area of the pigment is relatively large, pigment: binder = 20: 80 to 40:60 is preferable, and when the specific surface area of the pigment is relatively small, pigment: binder = 50: 50 to 80:20 is satisfied. preferable. Here, when the BET specific surface area is 150 m ² / g or less, the specific surface area of the pigment is relatively small, and when the BET specific surface area exceeds 150 m ² / g, the specific surface area of the pigment is relatively large.
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 0.1 parts by mass or more and 1 part by mass with respect to 100 parts by mass in total of the pigment and the binder. Less than the mass part is more preferable. In the outermost coating layer, the content of the polyacrylate with respect to 100 parts by mass of the binder is preferably 0.1 parts by mass or more and 3.5 parts by mass or less.
The content of the acetylene glycol derivative in the outermost coating layer is preferably 0.1 parts by mass or more and 0.5 parts by mass or less with respect to a total of 100 parts by mass of the pigment and the binder.
In the present invention, the content of the polyacrylate according to the present invention is not included in the content of the binder.

The pigment of the outermost coating layer is not particularly limited and is a conventionally known pigment in the coated paper field. The pigment is preferably a white pigment. Examples of white pigments include 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 inorganic pigments such as, and organic pigments such as plastic pigments. The outermost coating layer contains one or more selected from these pigments.
For pigments having a relatively small specific surface area, kaolin and light calcium carbonate are preferred. For pigments having a relatively large specific surface area, silica is preferred.

At least one of the pigments in the outermost coating layer is an average secondary particle in which primary particles having an average major axis / average minor axis of 2.0 or more and 7.0 or less are aggregated radially at one end in the major axis direction. It is preferably light calcium carbonate having a diameter of 2 μm or more and 6 μm or less.

The primary particles having an average major axis / average minor axis of 2.0 or more and 7.0 or less have an elongated shape and are generally called columnar, needle-like or spindle-like particles. The secondary particles are aggregates formed by radially aggregating such primary particles at one end in the major axis direction. Light calcium carbonate with an average secondary particle diameter of 2 μm or more and 6 μm or less formed by agglomeration of primary particles having an average major axis / average minor axis of 2.0 or more and 7.0 or less radially at one end in the major axis direction It is called light calcium carbonate or sea urchin-like light calcium carbonate or cocoon-like light calcium carbonate (hereinafter, also referred to as “chestnut-like light calcium carbonate”). For example, light calcium carbonate having the shape shown in JP-A-59-94700 and JP-A-2015-117437.

Examples of the method for producing light calcium carbonate include a carbon dioxide compounding method or a soluble salt reaction method. The carbon dioxide compounding method is a method for producing light calcium carbonate by dissolving quick lime obtained by firing limestone in water to form lime milk and reacting the lime milk with carbon dioxide. The soluble salt reaction method is a method for producing light calcium carbonate by reacting lime milk with a calcium chloride solution and sodium carbonate. The crystal system, size, and shape of light calcium carbonate can be adjusted according to reaction conditions and the like. Examples of the light calcium carbonate crystal system include calcite crystal and aragonite crystal. The calcite crystal is usually in the form of a spindle, a shape in which spindle-shaped particles are agglomerated and bonded, or a shape of cube (including a dumpling with inconspicuous corners) or a shape in which cubic particles are agglomerated and bonded. The aragonite crystal is usually columnar or needle-shaped, or a shape in which they are aggregated. These light calcium carbonates are commercially available from, for example, Shiraishi Calcium and Okutama Kogyo.
The chestnut-like light calcium carbonate is preferably an aragonite crystal. This is because the ink absorption or fog resistance is improved.

An average long diameter / average short diameter of 2.0 to 7.0 primary particles radially aggregated at one end in the long diameter direction and having an average secondary particle diameter of 2 μm to 6 μm. The content 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 with respect to 100 parts by mass of the pigment in the outermost coating layer. This is because the anti-fogging property, the anti-through-through property or the ink absorbability is improved.

The average minor axis and average major axis of the primary particles of light calcium carbonate, the shape of the secondary particles and the average secondary particle diameter can be determined by image analysis from a scanning electron micrograph of the outermost coating layer. . The average minor axis and average major axis of the primary particles are calculated by taking an electron micrograph using a scanning electron microscope and observing and actually measuring 100 arbitrary primary particles whose shape can be confirmed from the taken image. Can do. The average secondary particle size is obtained by taking an electron micrograph using a scanning electron microscope, and assuming that the projected area of the particle approximates a spherical shape with respect to any 100 secondary particles from the captured image. To calculate the average secondary particle size.

The binder of the outermost coating layer is a conventionally known binder and is not particularly limited. However, in the present invention, polyacrylate is excluded from conventionally known binders. Examples of conventionally known binders include starches and various modified starches, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, natural polymer resins such as casein, gelatin, soy protein, pullulan, gum arabic, karaya gum, and albumin or derivatives thereof, Polyvinylpyrrolidone, polyvinyl alcohol and various modified polyvinyl alcohols, polyacrylamide, polyethyleneimine, polypropylene glycol, polyethylene glycol, maleic anhydride resin, acrylic resin, methacrylic ester-butadiene copolymer, styrene-butadiene copolymer, ethylene- Thermosetting of vinyl acetate copolymers or functional group-modified copolymers with monomers containing functional groups such as carboxy groups of these various copolymers, melamine resins, urea resins, etc. Binders such as synthetic resins, polyurethane resins, unsaturated polyester resins, polyvinyl butyral, can be exemplified alkyd resin latex. The outermost coating layer contains one or more selected from these binders.

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

In the above general formula, M is Na, K or NH ₄ .

The polyacrylate 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 1500 or more and 50000 or less, and more preferably 5000 or more and 30000 or less. This is because the adhesion is improved. Ammonium polyacrylate having a weight average molecular weight of 1500 or more and 50000 or less is excellent as a protective colloid for the pigment, so that the flexibility of the outermost coating layer is increased. As a result, it is considered that the adhesion is improved. If the weight average molecular weight is less than 1500, it is considered that the protective colloid is insufficient, and if it exceeds 50,000, it is difficult to obtain flexibility.
The weight average molecular weight of the present invention is a polyethylene glycol conversion value of the gel permeation chromatography method.

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

R ₁ , R ₂ , R ₃ and R ₄ in the general formula (1) each represents an alkyl group having 1 to 5 carbon atoms. R ₁ , R ₂ , R ₃ and R ₄ preferably have a bilaterally symmetric structure around the acetylene group.

R ₅ , R ₆ , R ₇ and R ₈ in the general formula (2) each represents an alkyl group having 1 to 5 carbon atoms. m and n are each an integer of 1 to 25, and m + n is 2 to 40. OE is an oxyethylene chain (—O—CH ₂ —CH ₂ —), and OP is an oxypropylene chain (—O—CH ₂ —CH [CH ₃ ] —). OE and OP may each be a single chain or a mixed chain. R ₅ , R ₆ , R ₇ and R ₈ preferably have a bilaterally symmetric structure centering on the acetylene group.

The acetylene glycol derivative is commercially available from Nissin Chemical Industry Co., Ltd. under the name “Surfynol (registered trademark)” or “Olfine (registered trademark)” and from Kawaken Fine Chemical Co., Ltd. under the name “Acetylenol (registered trademark)”.

In the present invention, the acetylene glycol derivative is 2,4,7,9-tetramethyl-5-decyne-4,7-diol or 2,4,7,9-tetramethyl-5-decyne-4,7-diol. The ethoxylate is preferred. This is because it is easily available commercially.

The outermost coating layer can contain various conventionally known additives in the coated paper field, if necessary, in addition to the polyacrylate and the acetylene glycol derivative. Examples of additives include dispersants, fixing agents, thickeners, fluidity improvers, antifoaming agents, mold release agents, foaming agents, penetrating agents, coloring pigments, colored dyes, fluorescent whitening agents, UV absorbers , Antioxidants, preservatives, antifungal agents and the like.
Further, the outermost coating layer can contain various conventionally known auxiliaries by a transfer printing method. The auxiliary agent is added to optimize various physical properties of the outermost coating layer coating solution or to improve the dyeing property of the transferred sublimation printing ink. Examples of the auxiliary agent include various surfactants, humectants, wetting agents, pH adjusting agents, alkali agents, thickening agents, deaerating agents and reduction inhibitors.

The transfer paper of the present invention preferably has an air permeability determined in conformity with ISO 5636-3 obtained by measuring the side provided with the outermost coating layer and more than 100 ml / min and not more than 320 ml / min.

Generally, the air permeability of the base paper is a very high value compared to the air permeability of the coated paper in which the coating layer is provided on the base paper. This is because the components of the coating layer block the voids of the pulp fibers constituting the base paper. Therefore, normally, the air permeability of the coated paper can be adjusted by the coating layer.
The air permeability of the coated paper is a known physical property value in the coated paper field, and can be adjusted by the size and shape of the pigment in 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 depending on the coating amount of the coating layer or the presence / absence of calendar treatment and its conditions. The intended air permeability can be obtained by controlling the calendar conditions such as the temperature of the calendar roll, the calendar nip pressure, and the calendar nip time.
In the transfer paper of the present invention, the air permeability can be adjusted in the same manner as the general coated paper.

The transfer paper can be obtained by printing a pattern on the side 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 the design on the transfer paper are conventionally known printing methods and are not particularly limited. Examples of the printing method include a gravure printing method, an ink jet printing method, an electrophotographic printing method, a screen printing method, and the like. Among these, the ink jet printing method is preferable in terms of high image quality and downsizing of the apparatus.

The transfer printing method using sublimation type printing ink is a method having a step of printing a pattern on transfer paper to obtain transfer paper and a step of bringing transfer paper into close contact with the substrate. The process of making it adhere | attach includes heating and pressurization as needed. The conditions for heating and pressurizing in the step of adhering are conventionally known conditions in the transfer printing method. Examples of the step of bringing in close contact include a method in which the transfer paper is brought into close contact with the substrate to be printed with a press or a heating drum and heated and pressurized.

The substrate is a fiber material and is not particularly limited. The fiber material may be either a natural fiber material or a synthetic fiber material. Examples of natural fiber materials include cellulosic fiber materials such as cotton, hemp, 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 polyacryl. Examples of the configuration of the fiber material include woven fabrics, knitted fabrics, nonwoven fabrics, and the like alone, mixed spinning, mixed fiber, and union. Furthermore, these configurations may be combined. Moreover, you may pre-process a to-be-printed material with the chemical | medical agent effective in dyeing | staining promotion as needed.
In the transfer printing method using the sublimation type printing ink, the printed material is preferably a synthetic fiber material. Natural fiber materials often require pretreatment.

Hereinafter, the present invention will be described in more detail 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 amount of dry solids or the amount of substantial components, respectively. The coating amount of the coating layer represents the dry solid content.

<Base paper>
To a pulp slurry consisting of 100 parts by mass of LBKP having a freeness of 380 mlcsf, 10 parts by mass of calcium carbonate, 1.2 parts by mass of amphoteric starch, 0.8 parts by mass of sulfate band, 0.1 parts by mass of alkyl ketene dimer type sizing agent as fillers It was added and made with a long paper machine. Oxidized starch was attached to both sides with a size press machine at 1.5 g / m ² per side, and machine calendering was performed to prepare a base paper with a basis weight of 62 g / m ² . .

<Outermost coating layer coating solution>
The outermost coating layer coating solution was prepared by mixing and dispersing in water using the materials shown in Table 1.
Table 1 also shows the amount of each material in the outermost coating layer coating solution.

In Table 1, silica A is NIPGEL (registered trademark) AY-200 manufactured by Tosoh Silica. Silica B is MIZUKASIL (registered trademark) P-527 manufactured by Mizusawa Chemical. Light calcium carbonate is TamaPearl (registered trademark) TP221F (calcite crystal, average major axis / average minor axis = 2.0, average secondary particles not formed) manufactured by Okutama Kogyo Co., Ltd. The acetylene glycol derivative A is Surfynol 104E (structure of general formula (1)) manufactured by Nissin Chemical Industry. The acetylene glycol derivative B is Olfine E1010 (structure of the general formula (2)) manufactured by Nissin Chemical Industry Co., Ltd. Acetylene alcohol is Fine B manufactured by Nissin Chemical Industry. Except for Examples 24 and 25, ammonium polyacrylate having a weight average molecular weight of about 22,000 as measured by gel permeation chromatography was used. As the ammonium polyacrylates of Examples 24 and 25, those having a weight average molecular weight of about 6000 measured by gel permeation chromatography method were used.

<Transfer paper>
A transfer sheet was prepared by the following procedure.
On the base paper, the outermost coating layer coating solution was coated on one side with an air knife coater, dried with a hot air dryer, and then calendered to obtain a transfer paper. The coating amount is shown in Table 1.

“Polyacrylate content mass ratio” in Table 1 is the content of polyacrylate with respect to 100 parts by mass of the binder in the outermost coating layer.

<Preparation of transfer paper>
On the obtained transfer paper, using an ink jet printer (JV2-130II, manufactured by MIMAKI ENGINEERING) using a sublimation printing ink, an evaluation pattern using sublimation printing ink (cyan, magenta, yellow) is printed and transferred. I got paper.

<Printing (cut paper)>
A polyester cloth was used as the substrate. The obtained transfer paper and the polyester cloth were brought into close contact with each other, and heated at 200 ° C. for 1 minute using a thermal transfer press (manual wide swinger Model 221 manufactured by INSTA) to transfer the dye to the polyester cloth. Thereafter, the transfer paper was peeled from the polyester cloth to obtain a polyester cloth on which a pattern was formed.

<Evaluation of image degradation resistance>
From the point of sharpness of the design, the image quality of the polyester cloth on which the design was formed was sensory-evaluated based on the following criteria. In the present invention, the transfer paper has an image deterioration resistance if the evaluation is A, B or C.
A: Good level.
B: Almost no deterioration in image quality is observed, and the level is generally good.
C: Deterioration in image quality is recognized, but there is no practical problem.
D: Level at which deterioration of an image which is practically impossible is recognized.

<Evaluation of color development>
On a printed material, the color density of a solid image portion of three colors of sublimation printing ink (cyan, magenta, yellow) is measured using an optical densitometer (X-rite 530, manufactured by Sakata Inx Engineering Co., Ltd.). Totaled. The color developability was judged according to the following criteria. In the present invention, the transfer paper has good color developability if the evaluation is A or B.
A: Total value is 4.7 or more B: Total value is 4.4 or more and less than 4.7 C: Total value is less than 4.4

<Printing (roll paper)>
A rolled polyester cloth was used as the substrate. The obtained roll paper-like transfer paper and the polyester cloth are brought into close contact with each other, using a heating and pressurizing machine (200 ° C., 0.5 MPa, 2.5 m / min, roller type, contact time with roller 30 seconds), The dye was transferred to a polyester fabric. Thereafter, the transfer paper was peeled from the polyester cloth to obtain a polyester cloth on which a pattern was formed.

<Evaluation of adhesion>
For the polyester cloth on which the design was formed, the adhesiveness was subjected to sensory evaluation according to the following criteria in terms of the degree of out-of-focus and distortion of the design. In the present invention, if the transfer sheet is evaluated as A or B, it is excellent in adhesion.
A: Good level without blurring or distortion.
B: Almost no blur or distortion is observed, and the level is generally good.
C: Defocus and distortion are recognized, but there is no practical problem.
D: A level at which out-of-focus and distortion are recognized, causing a problem in practical use.

Evaluation results are shown in Table 1 above.

From the evaluation results of Table 1, Examples 1 to 25, in which the outermost coating layer corresponds to a transfer paper containing a pigment, a binder, a polyacrylate, and an acetylene glycol derivative, are image degradation resistance, color developability and adhesion. It turns out that it has. However, it can be seen that Comparative Examples 1 to 10, which do not correspond to the transfer paper, cannot satisfy any of the image deterioration resistance, color developability and adhesion.
From the comparison between the main examples 4 to 6 and examples 14 to 16 and the main examples 11 and 23, the content of polyacrylate in the outermost coating layer is 0.1 parts by weight with respect to 100 parts by mass of the binder. It can be seen that a range of not less than 3.5 parts by mass is preferred.
From the comparison between main examples 4 and 14 and main examples 7 and 17, it can be seen that the polyacrylate is preferably ammonium polyacrylate.
From Examples 1 to 23 in which the weight average molecular weight measured by the gel permeation chromatography method is about 22000 and Examples 24 and 25 in which the weight average molecular weight is about 6000, the weight average molecular weight of ammonium polyacrylate is preferably 5000 or more and 30000 or less. I understand.

Next, the following outermost coating layer coating solution was prepared.

<Outermost coating layer coating solution>
The outermost coating layer coating solution was prepared by mixing and dispersing in water using the materials shown in Table 2.
Table 2 also shows the amount of each material in the outermost coating layer coating solution.

In Table 2, the materials used are shown below.
Light calcium carbonate of Examples 26-36:
Callite (registered trademark) SA manufactured by Shiraishi Calcium
Aragonite crystal Average major axis / Average minor axis = 6.5
Average secondary particle size = 3.3 μm, chestnut-like calcium carbonate of Example 37:
Otatama Kogyo TamaPearl TP-121SA
Calcite-based crystal Average major axis / Average minor axis = 4.0
Average secondary particle size = 3.5 μm, chestnut-like light calcium carbonate of Examples 38 and 39:
Tama Pearl TP-221BM manufactured by Okutama Industry Co., Ltd.
Calcite crystal Average major axis / Average minor axis = 3.0
Average secondary particle size = 4.0 μm, chestnut-shaped light calcium carbonate of Example 40:
TamaPearl TP-121S manufactured by Okutama Kogyo Co., Ltd.
Calcite-based crystal Average major axis / Average minor axis = 4.0
Average secondary particle size = 4.3 μm, chestnut-like light calcium carbonate of Example 41:
TamaPearl TP-121MS manufactured by Okutama Industry Co., Ltd.
Calcite crystal Average major axis / Average minor axis = 3.0
Average secondary particle size = 2.3 μm, chestnut-like Light calcium carbonate of Example 42:
Tunex (registered trademark) E made by Shiraishi Calcium
Calcite crystal Average major axis / Average minor axis = 3.0
Average secondary particle size = 5.6 μm, chestnut-like light calcium carbonate of Examples 43 and 44:
Callite KT manufactured by Shiraishi Calcium
Aragonite crystal average major axis / average minor axis = 6.7
Average secondary particle size = 2.6 μm, chestnut-like light calcium carbonate of Examples 45 and 46:
Callite SA made by Shiroishi Calcium
Aragonite crystal Average major axis / Average minor axis = 6.5
Average secondary particle size = 3.3 μm, chestnut-shaped Kaolin of Examples 45 and 46:
Huber HG90
Average particle size = 0.19 μm
Light calcium carbonate of Example 47:
Callite SA made by Shiroishi Calcium
Aragonite crystal Average major axis / Average minor axis = 6.5
Average secondary particle size = 3.3 μm, chestnut-like silica of Example 47:
Finesil® X-37 manufactured by Oriental Silica
Average particle size = 2.6 μm
Light calcium carbonate of Example 48 Callite (registered trademark) SA manufactured by Shiraishi Calcium Co.
Aragonite crystal Average major axis / Average minor axis = 6.5
Average secondary particle size = 3.3 μm, chestnut-shaped

<Transfer paper>
A transfer sheet was prepared by the following procedure.
On the base paper, the outermost coating layer coating solution was coated on one side with an air knife coater, dried with a hot air dryer, and then calendered to obtain a transfer paper. The air permeability of the transfer paper was adjusted according to the coating amount and / or calendar processing conditions. The coating amount is shown in Table 2.

<Preparation of transfer paper>
On the obtained transfer paper, an evaluation pattern using sublimation printing ink (cyan, magenta, yellow, black) is printed using an ink jet printer (JV2-130II, manufactured by Mimaki Engineering Co., Ltd.) using sublimation printing ink. A transfer paper (roll paper) was obtained.

<Evaluation of strike-through resistance>
The transfer paper obtained as described above was subjected to sensory evaluation for see-through resistance according to the following criteria from the degree of image viewing from the back surface of the transfer paper. In the present invention, the transfer sheet has resistance to see-through if the evaluation is A or B.
A: A good level with almost no see-through.
B: Slight back-through is observed, but at a level where there is no practical problem in the subsequent transfer.
C: Level at which show-through is recognized and causes practical problems in the subsequent transfer.

<Evaluation of ink absorbency>
After the transfer paper obtained as described above is left at 23 ± 1 ° C. and 50 ± 2% RH for 5 hours, each color contour portion and cutout character portion are functionalized according to the following criteria with respect to the printed material near the roll core of the roll paper. evaluated. In the present invention, the transfer paper has ink absorptivity if it is evaluated as A or B.
A: Bleeding is not recognized in each color outline portion or extracted character by microscopic observation (× 25).
B: Slight blurring is observed in each color contour portion and extracted characters by microscopic observation (× 25).
It is difficult to recognize by visual observation, and there is no problem in actual use.
C: Bleeding is observed in each color outline portion and extracted characters by microscopic observation (× 25).
It is slightly recognized even by visual observation, which causes a problem in actual use.
D: Bleeding is observed in each color outline portion and extracted characters by visual observation.

<Evaluation of fog resistance>
The anti-fogging property was sensory-evaluated according to the following criteria by confirming the presence or absence of spotted stains on the printed material with a magnifying glass and visual observation. In the present invention, if the transfer sheet is evaluated as A or B, it is assumed that the fog resistance is good.
A: Specular stain is not observed with a magnifying glass, and the level is good.
B: Spotted stains are not recognized visually, and the level is generally good.
C: A practical lower limit level in which spotted stains that do not cause defects are observed visually.
D: Spot stains that cause defects are visually observed, and are not practical.

The evaluation results are shown in Table 2 above.

From the evaluation results of Table 2, at least one of the pigments in the outermost coating layer is such that the primary particles having a ratio of average major axis / average minor axis of 2.0 or more and 7.0 or less are radial at one end in the major axis direction. Light calcium carbonate having an average secondary particle diameter of 2 μm or more and 6 μm or less formed by agglomeration in the case of the transfer paper, the light calcium carbonate being 80 parts by mass or more with respect to 100 parts by mass of the pigment in the outermost coating layer It can be seen that Examples 26 to 48 have image deterioration resistance, fog resistance, anti-through-through resistance and ink absorbability.
Mainly from the comparison between Examples 26, 27, 29 to 31, 34, 35 and 48 and Examples 28, 32, 33 and 36, the transfer paper has an air permeability of more than 100 ml / min and not more than 320 ml / min. It turns out that it is preferable.

The transfer paper according to the present invention is a useful transfer paper that satisfies all of the following items.
(1) Image degradation can be suppressed on the substrate (image degradation resistance)
(2) The ability to suppress a decrease in color development on the substrate (color development)
(3) The transfer paper and the substrate to be in good contact (adhesion)
(4) Suppression of fogging on printed materials (fogging resistance)
(5) Suppression of back-through on transfer paper (anti-through-through resistance)
(6) The ink can be absorbed so that the ink does not ooze out on the transfer paper (ink absorbability).

Claims

A base paper and at least one coating layer on at least one side of the base paper, and the outermost coating layer located on the outermost side with respect to the base paper contains a pigment, a binder, a polyacrylate, and an acetylene glycol derivative. The transfer paper used for the transfer textile printing method using the sublimation type textile ink which contains.
2. The transfer paper according to claim 1, wherein in the outermost coating layer, the content of the polyacrylate with respect to 100 parts by mass of the binder is 0.1 parts by mass or more and 3.5 parts by mass or less.
The transfer paper according to claim 1 or 2, wherein the polyacrylate is ammonium polyacrylate.
The transfer paper according to claim 3, wherein the weight average molecular weight of the ammonium polyacrylate measured by a gel permeation chromatography method is 5000 or more and 30000 or less.
An average of at least one of the pigments in the outermost coating layer in which primary particles having an average major axis / average minor axis ratio of 2.0 to 7.0 are aggregated radially at one end in the major axis direction. The light calcium carbonate having a secondary particle diameter of 2 µm to 6 µm, wherein the light calcium carbonate is 80 parts by mass or more with respect to 100 parts by mass of the pigment in the outermost coating layer. Transfer paper as described.
6. The transfer paper according to claim 5, wherein the air permeability obtained in accordance with ISO 5636-3 obtained by measuring the side provided with the outermost coating layer is more than 100 ml / min and not more than 320 ml / min.