JP2006193856A - Binder composition for producing coated paper for gravure printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a binder composition for producing a coated paper for gravure printing, providing the coated paper having excellent white paper gloss and resistance to calender staining, and hardly causing miss dot in the gravure printing, i.e. providing excellent repeatability of dots. <P>SOLUTION: The binder composition for producing the coated paper for the gravure printing, obtained by forming a coated layer containing a pigment and a binder composition as essential components on a paper base contains a polymer emulsion containing a macromolecular compound (A) exhibiting hydrophilicity in the temperature range not higher than the temperature-sensitive point, and exhibiting hydrophobicity in the temperature range exceeding the temperature-sensitive point. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a binder composition for producing a coated paper for gravure printing, and more specifically, a gravure that produces good halftone dot reproducibility with less calendar stains even in high-temperature calender finishing, less occurrence of misdots in gravure printing. The present invention relates to a binder composition for producing a coated paper for printing.

  Conventionally, as a binder composition used for the production of coated paper for gravure printing, it is possible to obtain coated paper for gravure printing that has both good printability and good operability only by optimizing the glass transition temperature (hereinafter referred to as Tg). It is known that the lower the Tg, the better the cushioning properties, but the coated paper has poor rigidity and anti-calendar stain resistance. In order to improve this, for example, Patent Document 1 discloses that in a method for producing a gravure coated coated paper in which a coating layer is calendered at a high temperature of 100 to 230 ° C. in order to obtain smoothness, the gel content is 5 as a binder. It has been proposed to use a resin latex having a Tg of 15 to 45 ° C. at ˜55%. Further, for example, Patent Document 2 discloses a viscosity modifier together with a resin latex having a Tg of −20 ° C. to 20 ° C. and an average particle diameter of 70 to 130 nm in order to achieve both printability, high-speed coating property, and calendar drum stain resistance. There has been proposed a method of forming a coating layer by using a coating. Furthermore, for example, in Patent Document 3, a delaminated clay, which has been conventionally known to give a coating layer having good smoothness and cushioning properties, is used in an amount of 50% by mass or more as a pigment, and a bulky coating layer is formed. It is disclosed that the temperature-sensitive gelling latex to be applied is used as a binder composition. For example, in Patent Document 4, the amount of the emulsifier in the aqueous phase is 0.01 mmol / g (resin) or less, the glass transition temperature of the resin is −80 to 10 ° C., and the gel content in the resin is 60 to 100%. A binder composition comprising a resin latex having an average particle size of 150 to 250 nm and a heat-sensitive gelling agent has been proposed. However, since the thing of the said patent document 1 carries out a calendar process at high temperature, there exists a problem that the lifetime of a calendar | calender becomes short and long-term operation stability falls, and the thing of patent document 2 uses a viscosity modifier together. Therefore, the B-type viscosity of the coating liquid at room temperature (30 ° C.) is increased to about 17 times, and there is a problem that the handling property of the coating liquid is lowered. Moreover, since the thing of patent document 3 uses delaminated clay as a pigment 50 mass% or more, there existed a problem that the high shear viscosity of a coating liquid became high and the coating stability at high speed fell. . The thing of patent document 4 had the problem that the coating liquid viscosity was high and it was difficult to obtain the uniform coating surface.

JP-A-10-77598 JP-A-9-176997 Japanese Patent Laid-Open No. 10-237795 JP 2000-234293 A

  The object of the present invention is to provide a binder composition for the production of coated paper for gravure printing that is excellent in white paper gloss and anti-calendar roll stain resistance of coated paper and has few misdots in gravure printing, that is, excellent dot reproducibility. Is to provide things.

As a result of intensive studies to solve the above problems, the present inventors have shown that the polymer compound (A) exhibits hydrophilicity in a temperature region below the temperature sensitive point and exhibits hydrophobicity in a temperature region above the temperature sensitive point. It was found that a coated paper having good gravure printing suitability can be obtained without using a large amount of delaminated clay by using a polymer emulsion containing). That is, the present invention is as follows.
1) A binder composition for producing a coated paper for gravure printing in which a coating layer mainly composed of a pigment and a binder composition is provided on a paper substrate, and is hydrophilic in a temperature range below the temperature sensitive point. A binder composition for the production of coated paper for gravure printing, comprising a polymer emulsion containing a polymer compound (A) that exhibits properties and exhibits a hydrophobic property in a temperature range exceeding the temperature sensitive point.
2) For gravure printing according to the invention 1, wherein the polymer emulsion containing the polymer compound (A) is a polymer emulsion obtained by emulsion polymerization using a surfactant having a reactive group A binder composition for producing coated paper.
3) A coated paper for gravure printing comprising a coating layer formed from the binder composition for producing a coated paper for gravure printing according to 1) or 2) above.

  When the binder composition for producing a coated paper for gravure printing of the present invention is used, the coating for gravure printing is excellent in white paper gloss and calendar roll stain resistance, and has few misdots in gravure printing, that is, excellent dot reproducibility. You can get craft paper.

The present invention will be specifically described below.
The polymer compound (A) used in the present invention exhibits hydrophilicity in the temperature range below the temperature sensitive point and is hydrophobic in the temperature range above the temperature sensitive point. A homopolymer polymer of a monomer (main monomer (M)) or a copolymer polymer compound of two or more main monomers (M), which can obtain a polymer compound exhibiting hydrophilicity-hydrophobicity change due to Can react with the main monomer (M) to form a polymer compound, and the monomer (submonomer (N)) and the main monomer (for which the polymer compound exhibiting the temperature responsiveness cannot be obtained by homopolymerization) M) and a copolymerized polymer compound. The main monomer (M) and the submonomer (N) can be used alone or in combination of two or more.
A polymer compound having high temperature responsiveness can be obtained by homopolymerization of the main monomer (M), but the main monomer (M) is homopolymerized by copolymerizing the main monomer (M) and the submonomer (N). A polymer compound (A) having a temperature sensitive point different from that of the polymer compound can be obtained, or a polymer compound (A) having a film-forming property different from the homopolymerized polymer compound of the monomer (M) can be obtained. it can.

  The main monomer (M) is an N-alkyl or N-alkylene-substituted (meth) acrylamide derivative (where (meth) acryl is a simple notation of methacryl (or methacryl) or acryl), vinylmethyl Specific examples include N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-cyclopropyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-diethyl. Acrylamide, N, N-dimethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-methyl-Nn-propylacrylamide, N-methyl-N-isopropylacrylamide, N- (meth) acryloylpyrrolidine, N- (meth) acryloylpiperidi N-tetrahydrofurfuryl (meth) acrylamide, N-methoxypropyl (meth) acrylamide, N-ethoxypropyl (meth) acrylamide, N-isopropoxypropyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide, N- (2,2-dimethoxyethyl) -N-methylacrylamide, N-methoxyethyl (meth) acrylamide, N- (meth) acryloylmorpholine and the like. From the viewpoint of film formability, N-isopropylacrylamide, Nn-propylacrylamide, N, N-diethylacrylamide, and N-acryloylmorpholine are preferable.

  Examples of the auxiliary monomer (N) include lipophilic vinyl compounds, hydrophilic vinyl compounds, and ionic vinyl compounds. Specific examples of lipophilic vinyl compounds include methyl (meth) acrylate and ethyl (meth) acrylate. , N-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl methacrylate, styrene, α-methylstyrene, ethylene, isoprene, butadiene, vinyl acetate, vinyl chloride, and the like. As the hydrophilic vinyl compound, For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol acrylamide, diacetone acrylamide, methylene bisacrylamide, -Methyl-5-vinylpyridine, N-vinyl-2-pyrrolidone, N-acryloylpyrrolidine, acrylonitrile and the like. Examples of ionic vinyl compounds include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid. , Crotonic acid, Butenetricarboxylic acid, Monoethyl maleate, Monomethyl maleate, Monoethyl itaconate, Monomethyl itaconate, Monocarboxylic acid group-containing monomer, 2-acrylamido-2-methyl-propanesulfonic acid, styrenesulfonic acid, vinylsulfonic acid And sulfonic acid group-containing monomers such as (meth) acrylsulfonic acid, and amino group-containing monomers such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate. In particular, methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, styrene, 2-hydroxypropyl (meth) acrylate, acrylamide, methacrylamide, diacetone acrylamide, and methylene bisacrylamide are preferably used. It is done.

The copolymerization ratio of the main monomer (M) and the submonomer (N) is determined within a range in which the obtained copolymer polymer compound exhibits temperature responsiveness in which hydrophilicity and hydrophobicity change at a certain temperature as a boundary. It is done. That is, when the proportion of the submonomer (N) is too large, the copolymeric polymer compound obtained does not exhibit the temperature responsiveness.
That is, the copolymerization ratio of the main monomer (M) and the submonomer (N) depends on the combination of the monomer species used, but the ratio of the submonomer (N) in the resulting polymer compound is preferably 50% by mass or less. More preferably, it is 30 mass% or less. Moreover, 0.01 mass% or more is preferable in order that the addition effect of a submonomer (N) may be expressed better.

In the present invention, the “temperature sensitive point” of the polymer compound (A) is a temperature at which its hydrophilicity-hydrophobicity changes, and “temperature responsiveness” indicates the change in the hydrophilicity-hydrophobicity. Means nature. In the present invention, the term “hydrophilic” means that the polymer compound (A) in a system in which the polymer compound (A) and water coexist is more stable in a state compatible with water than in a phase separated state. In the system where the polymer compound (A) and water coexist, the polymer compound (A) is in a state in which the polymer compound (A) is phase-separated from water than in a state in which the polymer compound (A) is in solution. Means stable. The change in hydrophilicity-hydrophobicity is, for example, an abrupt viscosity change accompanying a temperature change in a system in which the polymer compound (A) and water coexist, or transparency in a system in which the polymer compound (A) and water coexist. It appears as a sudden change in the solubility of the polymer compound (A) in water. In the present invention, when the temperature of the system in which the polymer compound (A) and water coexist is gradually lowered from the temperature range where the polymer compound (A) exhibits hydrophobicity (temperature exceeding the temperature sensitive point). The temperature-sensitive point of the polymer compound (A) is determined as a transition point at which the temperature-viscosity curve obtained by measuring the viscosity of the polymer rapidly changes.
The polymer compound (A) of the present invention may be any of anionic, cationic, nonionic and amphoteric, but is preferably anionic from the viewpoint of miscibility with the pigment described later.
The cationic polymer compound (A) can be obtained, for example, by including an ethylenically unsaturated monomer having a cationic group as a secondary monomer (N) used for polymerization. The ethylenically unsaturated monomers having a cationic group can be used alone or in combination of two or more.

  Examples of the ethylenically unsaturated monomer having a cationic group include vinyloxyethyltrimethylammonium chloride, 2,3-dimethyl-1-vinylimidazolinium chloride, and trimethyl- (3- (meth) acrylamide-3,3-dimethyl. Propyl) ammonium chloride, trimethyl- (3-methacrylamidopropyl) ammonium chloride, trimethyl- (3-acrylamidopropyl) ammonium chloride, N- (1,1-dimethyl-3-dimethylaminopropyl) (meth) acrylamide and its 4 Quaternary ammonium salt, trimethyl- (3- (meth) acrylamide) ammonium chloride, 1-vinyl-2-methyl-imidazole, 1-vinyl-2-ethyl-imidazole, 1-vinyl-2-phenyl-imi Sol, 1-vinyl-2,4,5-trimethyl-imidazole, N, N-dimethylaminopropyl (meth) acrylate and its quaternary ammonium salt, N, N-dimethylaminoethyl (meth) acrylate and its quaternary ammonium Salt, N, N-diethylaminoethyl (meth) acrylate and its quaternary ammonium salt, t-butylaminoethyl (meth) acrylate and its quaternary ammonium salt, N- (3-dimethylaminopropyl) methacrylamide and its quaternary Ammonium salt, N- (3-dimethylaminopropyl) acrylamide and its quaternary ammonium salt, N- (3-diethylaminopropyl) methacrylamide and its quaternary ammonium salt, N- (3-diethylaminopropyl) acrylamide and its 4 Ammonium salt, o-, m-, p-aminostyrene and its quaternary ammonium salt, o-, m-, p-vinylbenzylamine and its quaternary ammonium salt, N- (vinylbenzyl) pyrrolidone, N- (vinyl Benzyl) piperidine, N-vinylimidazole and its quaternary ammonium salt, 2-methyl-1-vinylimidazole and its quaternary ammonium salt, N-vinylpyrrolidone and its quaternary ammonium salt, N, N′-divinylethyleneurea and Its quaternary ammonium salt, α-, or β-vinylpyridine and its quaternary ammonium salt, α-, or β-vinylpiperidine and its quaternary ammonium salt, 2-, or 4-vinylquinoline and its quaternary ammonium salt Etc. are exemplified. In particular, from the viewpoint of surface gloss of the resulting coated paper, for example, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, t-Butylaminoethyl (meth) acrylate, N- (3-dimethylaminopropyl) methacrylamide, N- (3-dimethylaminopropyl) acrylamide, N- (3-diethylaminopropyl) methacrylamide, N- (3-diethylamino Propyl) acrylamide is preferably used.

The copolymerization ratio of the main monomer (M) and the submonomer (N) containing the ethylenically unsaturated monomer having the cationic group is such that the obtained copolymer polymer compound has hydrophilicity and hydrophobicity with the temperature sensitive point as a boundary. It is determined within a range exhibiting reversible temperature response.
The preferred content of the ethylenically unsaturated monomer unit having a cationic group in the polymer compound (A) used in the present invention varies depending on the type and combination of the monomers used. From the viewpoint of the above, 0.01 mass% or more is preferable, and from the viewpoint of film formability, 50 mass% or less is preferable. More preferably, it is 0.1-30 mass%.
The polymer compound (A) preferably has a carboxyl group from the viewpoints of scratch resistance of the resulting coating layer, color developability of an image obtained by printing, etc., and the polymer compound (A) having the carboxyl group is For example, it can be obtained by including an ethylenically unsaturated monomer having a carboxylic acid group as a secondary monomer (N) used for polymerization. The ethylenically unsaturated monomers having carboxylic acid groups can be used alone or in combination of two or more.
Examples of the ethylenically unsaturated monomer having a carboxylic acid group include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, butenetricarboxylic acid, monoethyl maleate, monomethyl maleate, monoethyl itaconate, and itacone. Preferred examples include carboxylic acid group-containing monomers such as monomethyl acid, and it is particularly preferable to use acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid.
The copolymerization ratio of the main monomer (M) and the submonomer (N) containing the ethylenically unsaturated monomer having a carboxylic acid group is hydrophilic and hydrophobic with the obtained copolymer polymer compound as the boundary of the temperature sensitive point. Is determined within a range exhibiting temperature responsiveness that reversibly changes.

The preferred content of the ethylenically unsaturated monomer unit having a carboxylic acid group in the polymer compound (A) used in the present invention varies depending on the type and combination of the monomers used, but it is generally easy to adjust the coating solution. From the viewpoint of thickness, 0.01% by mass or more is preferable, and from the viewpoint of film formability, 30% by mass or less is preferable. More preferably, it is 0.1-10 mass%.
The glass transition point of the polymer compound (A) used in the present invention is preferably −50 to 150 ° C. from the viewpoints of film formability and the flexibility of the resulting coated paper, and 80 to 150 ° C. from the viewpoint of productivity. Is preferred. However, when importance is attached to the flexibility of the resulting coated paper, −50 to 30 ° C. is preferable.
The polymer emulsion containing the polymer compound (A) used in the present invention has a temperature-sensitive point that causes a viscosity change abruptly due to the influence of the hydrophilicity-hydrophobicity change due to the temperature change of the polymer compound (A). That is, in a temperature range exceeding the temperature sensitive point, the polymer emulsion containing the polymer compound (A) forms a stable emulsion in an aqueous solvent, and the coating liquid containing the polymer emulsion has a relatively low viscosity. However, since the polymer compound (A) is hydrophilic in the temperature range below the temperature sensitive point, the polymer emulsion swells or partially dissolves, and the viscosity of the coating solution is high. Or the viscosity increases over time. Therefore, it is preferable that the coating liquid of the present invention is maintained at a temperature higher than the temperature sensitive point of the polymer compound (A) of the present invention.

In producing the polymer compound (A), it is preferable to carry out the polymerization reaction in an aqueous solvent in a temperature range exceeding the temperature sensitive point of the polymer compound (A). Since the polymer compound (A) exhibits hydrophobicity and forms an emulsion in the temperature region, a widely known polymer emulsion production technique can be used in the temperature region. Specifically, the surfactant is dissolved in water, and the copolymerization monomer component such as the main monomer (M) and the submonomer (N) is added to emulsify, and the radical polymerization initiator is added to emulsify by a batch charging reaction. In addition to the method of performing polymerization, there may be mentioned a method of supplying the above copolymerization component or radical polymerization initiator to the reaction system by a method such as continuous dropping or divided addition.
In producing a polymer emulsion containing the polymer compound (A) used in the present invention, it is preferable to use a surfactant.
The polymer emulsion containing the polymer compound (A) used in the present invention may be any of anionic, cationic, nonionic and amphoteric.

When the polymer emulsion containing the polymer compound (A) is cationic, a cationic surfactant and / or a nonionic surfactant is used. For example, examples of the cationic surfactant include laurylamine hydrochloride, alkylbenzyldimethylammonium chloride, lauryltrimethylammonium chloride, alkylammonium hydroxide, and polyoxyethylene alkylamine. Nonionic surfactants include Examples thereof include polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan fatty acid ester, oxyethylene oxypropylene block copolymer, polyglycerin fatty acid ester and the like.
When the polymer emulsion containing the polymer compound (A) is anionic, an anionic surfactant and / or a nonionic surfactant is used. For example, fatty acid soap, alkyl sulfonate, alkyl sulfosuccinate, polyoxyethylene alkyl sulfate, polyoxyethylene alkyl aryl sulfate, p-styrene sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonate, formalin heavy Condensates, condensates of higher fatty acids and amino acids, dialkylsulfosuccinates, naphthenates, etc., alkyl ether carboxylates, acylated peptides, α-olefin sulfonates, N-acylmethyl taurines, alkyl ether sulfates And anionic surfactants such as secondary higher alcohol ethoxy sulfate, polyoxyethylene alkylphenyl ether sulfate, monoglyculate, alkyl ether phosphate ester, alkyl phosphate ester salt and the like.

Examples of the nonionic surfactant include polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan fatty acid ester, oxyethylene oxypropylene block copolymer, and polyglycerin fatty acid ester.
When the polymer emulsion containing the polymer compound (A) is nonionic, a nonionic surfactant is used. Examples of the nonionic surfactant include polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan fatty acid ester, oxyethylene oxypropylene block copolymer, and polyglycerin fatty acid ester.
When the polymer emulsion containing the polymer compound (A) is amphoteric, it is possible to use an amphoteric surfactant from the viewpoint of the stability of the polymer emulsion containing the polymer compound (A) to changes in pH. Preferably, a cationic surfactant can be used when the polymer emulsion containing the polymer compound (A) is cationic in the coating liquid of the present invention, and the coating liquid of the present invention can be used. Among them, when the polymer emulsion containing the polymer compound (A) is anionic, an anionic surfactant can be used. Examples of the amphoteric surfactant include carboxybetaine type, aminocarboxylate, lecithin and the like.
The amount of these surfactants used is preferably 0.05 to 50 parts by mass, more preferably 1 to 100 parts by mass of the resin solid content of the polymer emulsion containing the polymer compound (A). -30 mass parts.
In this invention, the said surfactant can also be used individually by 1 type, and can also use 2 or more types together.
By using a “surfactant having a reactive group” at the time of polymer emulsion polymerization containing the polymer compound used in the present invention, the amount of non-reactive surfactant used can be reduced. It is preferable from the viewpoint of water resistance. The surfactant having a reactive group is generally called a reactive surfactant, and examples thereof include a compound having a hydrophobic group, a hydrophilic group and a reactive group in the molecule. Examples of the reactive group include carbon-carbon double bonds such as a (meth) allyl group, a 1-propenyl group, a 2-methyl-1-propenyl group, an isopropenyl group, a vinyl group, and a (meth) acryloyl group. The functional group which has is mentioned.

Examples of the reactive surfactant having an anionic property include those having a structure such as a sulfonate group, a sulfate ester base, a carboxylate group, and a phosphate group. Examples of vinyl monomers having a sulfonate group include allyl sulfone. Acid, 2-methylallylsulfonic acid, vinylsulfonic acid, 4-vinylbenzenesulfonic acid, 2- (meth) acryloyloxyethanesulfonic acid, 3- (meth) acryloyloxypropanesulfonic acid, 2-acrylamido-2-methylpropane Examples thereof include those obtained by neutralizing various sulfonic acid group-containing vinyl monomers such as sulfonic acid with various basic compounds. Examples of the basic compound include lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia, methylamine, ethylamine, n-butylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, tri-n-butylamine, diethanolamine, 2- Examples thereof include dimethylaminoethyl alcohol, tetramethylammonium hydroxide, and tetra-n-butylammonium hydroxide. Examples of the vinyl monomer containing a sulfate ester base include those obtained by neutralizing vinyl monomers containing a sulfate ester group such as sulfate of allyl alcohol with the various basic compounds. Examples of vinyl monomers containing a phosphate group include those obtained by neutralizing phosphate group-containing vinyl monomers such as mono {2- (meth) acryloyloxyethyl} acid phosphate with the various basic compounds. It is done. Examples of the reactive surfactant having an anionic property containing an allyl group (CH ₂ ═C (—R) —CH ₂ —) (where R is an alkyl group) include, for example, sulfate of polyoxyethylene allyl glycidyl nonyl phenyl ether Examples of commercially available products include “Adekaria Soap SE-10N” series (trademark: manufactured by Asahi Denka Kogyo Co., Ltd.), “Eleminol JS-2” (trademark: manufactured by Sanyo Chemical Industries, Ltd.), “Latemul S-180 or S-180A” (trademark: manufactured by Kao Corporation), “H3390A” and “H3390B” (trademark: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and the like. As a reactive surfactant having an anionic property containing a (meth) acryloyl group (CH ₂ ═C (—R) —C (═O) —O—) (where R is an alkyl group), for example, as a commercially available product , “Eleminol RS-30” series (trademark: manufactured by Sanyo Chemical Industries, Ltd.), “Antox MS-60” series (trademark: manufactured by Nippon Emulsifier Co., Ltd.), and the like. Examples of the reactive surfactant having an anionic property containing a propenyl group (CH ₃ —CH═CH—) include ammonium sulfate salt of polyoxyethylene nonylpropenyl phenyl ether and the like. HS-10 "series and" Aqualon BC "series (trademark: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

Examples of the reactive surfactant having a cationic property include cationic vinyl monomers containing a structure having a cationic property such as an amine base. Examples of vinyl monomers having an amine base include neutralizing amino group-containing vinyl monomers such as allylamine, N, N-dimethylallylamine, N, N-diethylallylamine, and N, N-diethylaminopropyl vinyl ether with various acidic compounds. Can be obtained. Examples of the acidic compound include hydrochloric acid, formic acid, acetic acid, lauric acid and the like. Examples of commercially available reactive surfactants having cationic properties include "RF-751" (trademark: manufactured by Nippon Emulsifier Co., Ltd.) and "Blemmer QA" (trademark: manufactured by Nippon Oil & Fats Co., Ltd.).
Examples of nonionic reactive surfactants include various polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene higher fatty acid esters, polyoxyethylene-polyoxypropylene block copolymers, and the like. Examples thereof include vinyl ethers having an ether chain in the side chain, monomers of allyl ethers or (meth) acrylic acid esters. Examples of the nonionic reactive surfactant containing an allyl group (CH ₂ ═C (—R) —CH ₂ —) (where R is an alkyl group) include polyoxyethylene allyl glycidyl nonyl phenyl ether. Examples of commercially available products include “Adekaria Soap NE” series (Asahi Denka Kogyo Co., Ltd.). As a nonionic reactive surfactant containing a (meth) acryloyl group (CH ₂ ═C (—R) —C (═O) —O—) (where R is an alkyl group), as a commercially available product, “ RMA-560 "series (manufactured by Nippon Emulsifier Co., Ltd.)," Blenmer PE "series (manufactured by Nippon Oil & Fats Co., Ltd.), and the like. Examples of the nonionic reactive surfactant containing a propenyl group (CH ₃ —CH═CH—) include polyoxyethylene nonylpropenyl phenyl ether, and commercially available products include “AQUALON RN series” (No. Ichi Kogyo Seiyaku Co., Ltd.).
The amount of these reactive surfactants used is preferably 0.05 to 100 parts by weight, more preferably 1 with respect to 100 parts by weight of the solid content of the polymer emulsion resin containing the polymer compound (A). -50 mass parts.
In the present invention, the reactive surfactant can be used alone, or two or more of the reactive surfactants can be used in combination. Further, the reactive surfactant is used in combination with the non-reactive surfactant. You can also

When producing the polymer emulsion containing the polymer compound (A) of the present invention, a known radical polymerization initiator is used. Polymerization initiators include organic polymerization initiators [peroxides (cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramentane hydroperoxide, benzoyl peroxide, lauroyl peroxide, etc.), azo compounds (azobisisobutyrate). Ronitrile, azobisisovaleronitrile, etc.)
], Inorganic polymerization initiators [persulfates (sodium persulfate, ammonium persulfate, potassium persulfate, etc.), hydrogen peroxide, etc.]. The usage-amount of a radical polymerization initiator is 0.01-5 mass% with respect to the monomer mixture whole quantity, Preferably it is 0.1-3 mass%.
In addition, a known chain transfer agent can be used for the purpose of adjusting the molecular weight of the polymer, the gel content of the latex, and the like. As the chain transfer agent, α-methylstyrene dimer (2,4-diphenyl-4-methyl-1-pentene etc.), terpinolene, terpinene, dipentene, alkyl mercaptan having 8 to 18 carbon atoms, alkylene having 8 to 18 carbon atoms Examples include dithiol, alkyl thioglycolate, dialkylxanthogen disulfide, teraalkylalkylthiuram disulfide, chloroform, carbon tetrachloride and the like. These can be used alone or in combination of two or more. The amount of the chain transfer agent used is 0 to 15% by mass, preferably 0 to 5% by mass, based on the total amount of the monomer mixture.
Further, if necessary, a reducing agent [sodium pyrobisulfite, sodium sulfite, sodium hydrogen sulfate, ferrous sulfate, glucose, formaldehyde sodium sulfoxylate, L-ascorbic acid (salt)], chelating agent (glycine, alanine, ethylenediamine tetra An additive such as a pH buffer (sodium tripolyphosphate, potassium tetrapolyphosphate, etc.) may be used in combination. The usage-amount of these additives is 0-5 mass% with respect to the monomer mixture whole quantity, Preferably it is 0-3 mass%.

The average particle diameter of the polymer emulsion particles containing the polymer compound (A) used in the present invention is from the viewpoint of the film forming properties of the coating layer and the production efficiency of the polymer emulsion containing the polymer compound (A). 10 to 600 nm, more preferably 10 to 300 nm, and most preferably 20 to 100 nm. The average particle size referred to here is the number average particle size of the polymer emulsion containing the polymer compound (A) measured by the dynamic light scattering method in the temperature range where the polymer compound (A) exhibits hydrophobicity. is there.
It is preferable that the coating liquid contains a crosslinking agent capable of crosslinking the polymer compound (A) from the viewpoint of scratch resistance of the resulting coated paper.
In particular, it is industrially desirable that the crosslinking reaction does not proceed in the coating solution before coating, but the crosslinking reaction proceeds after coating. The reaction is preferably a reaction of a carbonyl group with a hydrazine group or a semicarbazide group. That is, it is preferable to polymerize the polymer compound (A) having a carbonyl group and use a hydrazine derivative having a hydrazine group and / or a semicarbazide group as a crosslinking agent.
The polymer compound (A) containing a carbonyl group is obtained, for example, by copolymerizing a main monomer (M) and a submonomer (N) containing a monomer containing a carbonyl group. The main monomer (M) and the submonomer (N) containing a monomer containing a carbonyl group can be used alone or in combination of two or more. As for the copolymerization ratio of the main monomer (M) and the submonomer (N) containing the carbonyl group-containing monomer, the hydrophilicity and hydrophobicity of the obtained copolymeric polymer compound change reversibly at the temperature sensitive point. It is determined within a range exhibiting temperature responsiveness.

The content of the carbonyl group-containing monomer unit in the polymer compound (A) is preferably from 0.01 to 50 mass%, more preferably from 0.1 to 20 mass%, from the viewpoint of film formability.
The carbonyl group-containing monomer is not particularly limited as long as the monomer has a structure containing a keto group or an aldo group. For example, acrolein, diacetone acrylamide, diacetone methacrylamide, formyl styrene, vinyl methyl ketone, vinyl Examples include ethyl ketone, vinyl isobutyl ketone, acryloxyalkyl propanals, methacryloxyalkyl propanals, diacetone acrylate, diacetone methacrylate, acetonitrile acrylate, 2-hydroxypropyl acrylate acetyl acetate, butanediol acrylate acetyl acetate, etc. .
When the polymer compound (A) contains a carbonyl group, it is possible to use a hydrazine derivative having at least two hydrazine groups and / or a semicarbazide group as a crosslinking agent in the coating solution. It is preferable from the viewpoint of strength and the like. A coating layer containing a compound having a molecular structure in which a carbonyl group site is cross-linked by a hydrazine derivative by adding, mixing, coating and drying the hydrazine derivative to a coating solution containing the polymer compound (A). Can be obtained. As the hydrazine derivative, a compound having at least two hydrazine groups and / or a semicarbazide group is used. Among these, examples of the compound having a hydrazine group include carbohydrazide, isophthalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, Glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, polyacrylic acid hydrazide, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-1 1,4-dihydrazine, hydrazine hydrate and the like are exemplified, and examples of the compound having a semicarbazide group include a product obtained by reaction of a polyisocyanate compound and the hydrazine compound. It is. As the hydrazine derivative, a compound having a semicarbazide group is preferable because the resulting recording medium has high water resistance. The content of the hydrazine derivative is preferably 0.01 to 10 times the molar amount of the carbonyl group-containing monomer unit in the obtained polymer compound (A).

The binder composition of the present invention can contain a known water-soluble polymer as required. Specific examples include polyvinyl alcohol, partially saponified products of ethylene-vinyl acetate copolymer, polyvinyl alcohol typified by partially acetalized products of polyvinyl alcohol and the like, such as oxidized starch, phosphated starch, cation Starch, casein, soy protein, synthetic protein, mannangalactan derivative, starch typified by carboxymethylcellulose or the like, for example, acrylamide polymer, acrylamide- (meth) acrylic acid soda copolymer, polyacrylamide Mannich modification Polyacrylamides typified by products, for example, formalin resins typified by urea-formalin resin, melamine-formalin resin, etc., polyethyleneimine, polyamide polyamine-epichlorohi Phosphorus, styrene - soda salt of maleic acid copolymer, (meth) acrylic acid alkyl ester - include soda salts of (meth) acrylic acid copolymer. Content of water-soluble polymer is 0-2500 mass parts with respect to 100 mass parts of resin solid content of a polymer emulsion, Preferably it is 20-500 mass parts.
Among these, polyvinyl alcohol or a modified product thereof and starch or a modified product thereof are preferable in terms of providing good water retention.
If necessary, the binder composition of the present invention may further contain known pigments such as various clays, kaolin, calcium carbonate, satin white, titanium oxide, aluminum hydroxide, barium sulfate, zinc oxide, calcium sulfate, talc, and plastic. Pigment, etc. can be contained. Content of a pigment is 0-2500 mass parts with respect to 100 mass parts of resin solid content of a polymer emulsion, Preferably it is 300-1000 mass parts.
Further, if necessary, for example, a pigment dispersant represented by sodium poly (meth) acrylate, sodium pyrophosphate, sodium hexametaphosphate, etc., for example, an antifoam represented by a mineral oil-based antifoaming agent, a silicon-based antifoaming agent, or the like. Additives such as foaming agents, lubricants, pH adjusters, preservatives, water-proofing agents, and printing suitability improvers can also be included. The content of these additives is 0 to 250 parts by mass, preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the resin solid content of the polymer emulsion.

An example of the formulation of the coating liquid for producing gravure printing coated paper using the binder composition of the present invention is as follows (solid content parts by mass).
Usually, preferably a binder composition 2-100 5-36
Water-soluble polymer 2-50 5-25
Pigment 100 100
Pigment dispersant 0-10 0.05-5
Other additives 0-10 0.05-5
Moreover, solid content concentration of the coating liquid for coated paper is 10-80 mass% normally, Preferably it is 30-65 mass%.
Next, an example of a method for producing a coating liquid used for gravure coated paper using the binder composition of the present invention will be described. First, the pigment is dispersed in water using a dispersing device in the presence of a pigment dispersant, an antifoaming agent, etc. to obtain a pigment slurry. Subsequently, a coating liquid is obtained by mix | blending the binder composition of this invention, and said other additive. Examples of the dispersing device include a high speed mixer, a keddy mill, a speed mill, a sigma blade kneader, a more house mill, and a lead kneader.

The coated paper is obtained by applying a coating liquid for coating paper to a base paper for coating using a coating machine, heat drying and, if necessary, smoothing treatment. The coating amount of the coating liquid, as the weight after drying is usually 1 to 50 g / ^{m 2,} preferably from 5 to 25 g / ^{m 2.}
The base paper for coating is not particularly limited, and acidic or neutral high-quality paper, medium-quality paper, or lower grade paper (basis weight is 35 to 400 g / m ² ) is used as it is or after being calendered. Further, if necessary, a modified starch aqueous solution, a general coating solution or a coating solution obtained by using the binder composition of the present invention was preliminarily applied in an amount of 0.1 to 50 g / m ² as a weight after drying. Coated paper may be used as the base paper for coating.
The coating is performed in one layer or two or more layers by a coating machine. Coating machines include roll coaters (size press, gate roll coater, etc.), double-sided simultaneous coating type coaters (bill blade coaters, twin blade coaters, etc.), various blade coaters (bench type blade coaters, helicopters, etc.), air knife coaters. On-machine or off-machine coaters provided with a rod coater, brush coater, curtain coater, Champlex coater, bar coater, gravure coater and the like.
In the present invention, after the coating solution is applied and before the following drying, the production apparatus includes means for quickly cooling the coating layer to a temperature not higher than the temperature sensitive point. It is preferable from the viewpoint of gloss. As a means for performing the cooling, air cooling by a blower, a cold air blower or the like is preferable.

The paper coated with the coating solution is dried with a dryer and then smoothed as necessary. Examples of the dryer include an infrared dryer, a drum dryer, an air cap dryer, an air foil dryer, an air conditioner bear dryer, and combinations thereof.
The smoothing process can be performed by using a commonly used calendar such as a super calendar, a gloss calendar, a soft calendar, or a machine calendar on or off machine, for example, a wet cast method using a cast drum, a rewet cast method, It can also be performed by a so-called cast finish such as a gelled cast method. The treatment pressure and temperature are not particularly limited, and the nip pressure is usually 20 to 500 N / mm, and the temperature is usually room temperature to 300 ° C. The number of pressure nips is usually 1-15. Moreover, a water coating device using a roll, an electrostatic humidifier, a steam humidifier, and the like can be arranged together with the calendar for humidity control and humidification of the coated paper after finishing.

Hereinafter, the present invention will be described based on examples.
In the following examples and comparative examples, “parts” and “%” represent “parts by mass” and “mass%”. Various physical properties were measured as follows.
The number average particle diameter was measured by ELS-800 manufactured by Otsuka Electronics Co., Ltd. by a dynamic light scattering method. When measuring the particle diameter of the polymer emulsion, it was measured at a temperature higher than the temperature sensitive point.
The temperature sensitive point of the polymer compound (A) emulsion used in the present invention; the temperature of the polymer emulsion (A) adjusted to 5% by mass with an aqueous solvent while maintaining the temperature above the polymerization temperature is gradually increased. The viscosity of the emulsion was measured and the transition point at which the temperature-viscosity curve changed rapidly was determined as the temperature sensitive point of the polymer compound (A) emulsion.
Blank paper gloss was evaluated sensuously by looking at the reflection of fluorescent light. The evaluation results were evaluated on a five-point scale, with 5 being a very good result, 4 being a good result, 3 being a slightly good result, 2 being a poor result, and 1 being a very poor result.
Misdots were printed using a printing station type gravure printing appropriate tester manufactured by Kumagai Riki Kogyo Co., Ltd. under the conditions of a printing pressure of 20 kg / cm and a printing speed of 100 m / min, and 1 cm ^{2 at} a dot area of 15%. It was evaluated sensuously from the number and distribution of missed dots per hit. The evaluation results were evaluated on a five-point scale, with 5 being a very good result, 4 being a good result, 3 being a slightly good result, 2 being a poor result, and 1 being a very poor result.
The stain resistance is visually observed on the cast drum after the coated paper is prepared, ◎ if there is no stain, ○ if there is very little stain, × if there is a lot of stain. Indicated.

(Preparation Example 1)
In a reaction vessel equipped with a stirrer, a reflux condenser, a dropping tank, and a thermometer, 360 parts of water was added to bring the inside of the reaction vessel to 80 ° C. Next, 21 parts of a 38% aqueous solution of “Eleminol JS-2” and 12 parts of “ADEKA rear soap SE-1025N” (25% aqueous solution) were added to the reactor. Further, 8 parts of a 2% aqueous solution of ammonium persulfate was put into the reactor, and after 5 minutes, 9 parts of methyl methacrylate, 9 parts of butyl acrylate, 9 parts of styrene, 2 parts of diacetone acrylamide and 2 parts of acrylic acid were added. The mixed liquid was continuously added into the reactor over 30 minutes. The addition was performed while keeping the inside of the reaction vessel at 80 ° C. The number average particle size of the emulsion at this stage was 11 nm. Subsequently, 290 parts of N-isopropylacrylamide, 10 parts of diacetone acrylamide, 0.5 parts of methylenebisacrylamide, 0.5 parts of acrylic acid, 3 parts of 38% aqueous solution of “Eleminol JS-2”, “Adekalia” Addition of 11 parts of "SOPE SE-1025N" (25% aqueous solution) and 46 parts of 2% aqueous solution of ammonium persulfate into the reaction vessel was started, and the addition was completed over 5 hours. During the addition and for 1 hour after the completion of the addition, the liquid temperature in the reaction vessel was kept at 80 ° C., then cooled to 40 ° C., the pH of the emulsion was adjusted to 9 with 5% ammonia water, and the number average particle size was 100 nm. As a result, polymer compound 1 was obtained. The temperature point was measured and found to be 30 ° C. The resulting polymer emulsion was stored at 40 ° C.

(Preparation Example 2)
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 45 parts of water was added to bring the inside of the reaction vessel to 80 ° C. Next, 0.3 part of 25% aqueous solution of “ADEKA rear soap SE1025N” (manufactured by Asahi Denka Kogyo Co., Ltd., surfactant: trade name) and 0.5 part of 2% aqueous solution of ammonium persulfate were added. Five minutes later, 5 parts of methyl methacrylate, 5 parts of butyl acrylate, 0.8 part of 25% aqueous solution of “ADEKA rear soap SE1025N”, 1 part of 2% aqueous solution of ammonium persulfate and 10 parts of water were pre-emulsified with a homogenizer. And a solution prepared by dissolving 35 parts of N-isopropylacrylamide in 160 parts of water were respectively added to the reaction vessel, and the addition was completed over 4 hours. During the addition and for 1 hour after the completion of the addition, the liquid temperature in the reaction vessel was kept at 80 ° C., then cooled to 40 ° C., the pH of the emulsion was adjusted to 9 with 5% ammonia water, and the number average particle size was 250 nm. As a result, polymer compound 2 was obtained. The temperature point was measured and found to be 23 ° C. The resulting polymer emulsion was stored at 40 ° C.
(Preparation Example 3)
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 600 parts of water and 38% aqueous solution of “Eleminol JS-2” (manufactured by Sanyo Chemical Industries, Ltd., anionic surfactant: trade name) 15 parts and 9 parts of “ADEKA rear soap SE-1025N” (25% aqueous solution) were added, and the inside of the reaction vessel was set to 80 ° C. Next, an additive liquid (1) obtained by mixing 4 parts of diacetone acrylamide, 128 parts of styrene, 80 parts of methyl methacrylate, and 66 parts of butyl methacrylate,
An additive solution (2) obtained by dissolving 2 parts of 38% aqueous solution of “Eleminol JS-2”, 8 parts of “ADEKA rear soap SE-1025N” (25% aqueous solution) and 40 parts of 2% aqueous solution of ammonium persulfate in 100 parts of water Were added from the dropping tank into the reaction vessel over 4 hours. The temperature in the reaction vessel was kept at 80 ° C. during the addition and for another hour after the addition was completed, and then cooled to room temperature. Thereafter, the pH of the emulsion was adjusted to 9 with 5% aqueous ammonia to obtain polymer compound 3 in which an emulsion having a resin solid content of 30% and a number average particle size of 40 nm was formed. Attempts were made to measure the temperature sensitive point, but no change that was judged to be a temperature sensitive point occurred.

[Example 1]
Water 15 parts Dispersant [manufactured by San Nopco, SN Dispersant 5040]
0.3 part sodium hydroxide 0.1 part defoaming agent manufactured by San Nopco, Nopco DF122-NS]
0.1 part Primary clay 50 parts The above components are dispersed and mixed with a disper (2,000 rpm) for 30 minutes, heated to 40 ° C., and then the polymer compound 1 obtained in Preparation Example 1 is added to the mixture. 12 parts (mass part of solid content) and 8.3 parts of pregelatinized phosphate esterified starch (30% aqueous solution) were added and mixed uniformly to prepare coating solution 1. In a state where the coating liquid 1 is kept at 40 ° C., a high-quality coated paper having a basis weight of 50 g / m ² is coated at 800 m / min with a blade coater so that the dry coating amount is about 10 g / m ² . The coated surface was blown for 10 minutes using a blower, and then dried with a hot air dryer having a hot air temperature of 150 ° C. until the pure water content reached 6%. Next, the coated paper 1 was prepared by performing smooth finishing by passing paper twice at a heat roll temperature of 90 ° C., a linear pressure of 250 N / mm, and a speed of 600 m / min. The stain resistance (situation of occurrence of stain on the cast drum) in the smooth finish, the glossiness of the white paper of the obtained coated paper 1, and the misdots were measured. The results are shown in Table 1.
[Example 2]
A coating solution 2 was prepared in the same manner as in Example 1 except that the polymer compound 2 obtained in Preparation Example 2 was used. Using the coating liquid 2, a coated paper 2 was prepared in the same manner as in Example 1. As in Example 1, stain resistance, white paper gloss, and misdots were measured. The results are shown in Table 1.
[Comparative Example 1]
A coating solution 3 was prepared in the same manner as in Example 1 except that the polymer compound 3 obtained in Preparation Example 3 was used. Using the coating solution 3, a coated paper 3 was prepared in the same manner as in Example 1. As in Example 1, stain resistance, white paper gloss, and misdots were measured. The results are shown in Table 1.

  By using the binder composition of the present invention, it is possible to obtain a coated paper for gravure printing that is excellent in white paper gloss and calendar roll stain resistance, has few misdots in gravure printing, that is, gives excellent halftone dot reproducibility. The utility value of is great.

Claims (3)

  A binder composition for producing a coated paper for gravure printing in which a coating layer mainly composed of a pigment and a binder composition is provided on a paper substrate, and has hydrophilicity in a temperature range below the temperature sensitive point. A binder composition for producing a coated paper for gravure printing, comprising a polymer emulsion containing a polymer compound (A) that exhibits hydrophobicity in a temperature range that exceeds the temperature sensitive point.   2. The gravure printing coating according to claim 1, wherein the polymer emulsion containing the polymer compound (A) is a polymer emulsion obtained by emulsion polymerization using a surfactant having a reactive group. Binder composition for paper manufacture.   A coated paper for gravure printing, comprising a coating layer formed from the binder composition for producing coated paper for gravure printing according to claim 1 or 2.