JP2008036935A - Resin composition for forming inkjet receiving layer, inkjet receiving agent and inkjet recording medium using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for forming an inkjet receiving layer capable of forming the ink receiving layer which has excellent color developing properties, can suppress running of ink, and is excellent in coating film strength, an inkjet receiving agent and an inkjet recording medium having the inkjet receiving layer formed by using the inkjet receiving agent. <P>SOLUTION: The resin composition for forming the inkjet receiving layer is characterized by comprising (A) cationic acrylic polymer particles, (B) a silane coupling agent, (C) a filler and (D) a water-based medium. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin composition for forming an ink jet receiving layer capable of forming an ink jet receiving layer excellent in ink absorbability, color developability and coating strength, an ink jet receiving agent, and an ink jet recording medium using the same.

In recent years, in the industry related to ink-jet printing, which has been growing rapidly, the performance of ink-jet printers and the improvement of ink have progressed dramatically, and it is now possible to easily obtain high-definition images comparable to silver halide photographs even in ordinary households. .
However, there is a limit to improving the image quality of printed images only by improving ink jet printers and inks, and in recent years, there has been an active study of improving the image quality of printed images with a focus on improving ink jet recording media.

  The ink jet recording medium usually has an ink jet receiving layer for absorbing ink and forming an image on a substrate such as paper, and the ink jet receiving layer is used for printing a high quality image. In order to make this possible, excellent color developability and performance capable of suppressing ink bleeding are required.

  In addition, the ink jet receiving layer constituting the ink jet recording medium is likely to cause peeling due to the influence of external force such as friction or change with time, and dropping of the pigment constituting the receiving layer, which is generally referred to as powder falling. The print image may be deteriorated or damaged. Therefore, the ink jet recording medium is strongly required to have an ink jet receiving layer excellent in coating strength, in addition to the performance excellent in color developability and suppressing bleeding.

Specifically, for example, for ink jet recording having an ink receiving layer containing a binder containing a self-emulsifying cationic resin made of a water-insoluble acrylic copolymer and a pigment on at least one surface of a support. It is known that a sheet is capable of recording a high color and non-bleeding image at high speed and has excellent coating strength (for example, see Patent Document 1).
In addition, an ink jet recording sheet having an image-receiving layer containing a specific amount of a crosslinkable group-containing cationic acrylic copolymer, a saponified vinyl acetate copolymer and a blocked isocyanate compound has improved ink absorption and water resistance. It is known to be excellent (see, for example, Patent Document 2).

However, it is difficult to say that the above-described ink jet recording medium has a coating strength that can sufficiently withstand external force such as friction, and it does not reach the level required by the industry.
Japanese Patent Laid-Open No. 9-99633 JP 2001-150804 A

  The problem to be solved by the present invention is to provide an ink-jet receiving layer-forming resin composition and an ink-jet receiving agent that can form an ink-jet receiving layer that has excellent color developability, can suppress ink bleeding, and has excellent coating strength. And an inkjet recording medium having an inkjet receiving layer formed using the inkjet receiver.

  In order to solve the above-mentioned problems, the inventors of the present invention, in a resin composition containing a cationic group-containing acrylic polymer, a filler and an aqueous medium as described in Patent Document 1, Furthermore, it has been found that a resin composition for forming an ink-jet receiving layer containing a silane coupling agent not only has excellent color developability and can suppress ink bleeding but also can improve the coating strength of the ink-jet receiving layer. The present invention has been completed.

That is, the present invention comprises a resin for forming an ink-jet receiving layer, comprising cationic acrylic polymer particles (A), a silane coupling agent (B), a filler (C), and an aqueous medium (D). It relates to a composition.
The present invention also relates to an ink jet recording medium having an ink jet receiving layer formed by applying an ink jet receiving agent comprising the resin composition for forming an ink jet receiving layer on a substrate and then drying.

  The resin composition for forming an ink jet receiving layer of the present invention has excellent ink absorbability and color developability even when the ink jet receiving layer is thinner than the conventional film thickness, and has excellent coating properties. An ink jet receiving layer having film strength can be formed. An ink jet recording medium having an ink jet receiving layer formed by the resin composition for forming an ink jet receiving layer of the present invention can be used for various applications such as paper used for printing photographs taken with a digital camera. is there.

The present invention is characterized by containing cationic acrylic polymer particles (A), a silane coupling agent (B), a filler (C), an aqueous medium (D), and other additives as required. It relates to a resin composition for forming an inkjet receiving layer.
In the resin composition for forming an ink jet receiving layer of the present invention, the cationic acrylic polymer particles (A) and the filler (C) are each independently dispersed in the aqueous medium (D), and the silane coupling agent (B). Is dissolved or dispersed in the aqueous medium (D).

First, the cationic acrylic polymer particles (A) constituting the resin composition for forming an ink jet receiving layer of the present invention will be described.
The cationic acrylic polymer particles (A) used in the present invention have a cationic property as a whole, and for example, due to the contribution of acrylic polymer particles having a cationic group or a dispersant having a cationic group. Including acrylic polymer particles dispersed in water. Examples of the cationic group include a tertiary amino group or a salt thereof, and a quaternary ammonium base.
The cationic acrylic polymer particles (A) used in the present invention are obtained by polymerizing various polymerizable monomers having an acrylic monomer as a main component. The cationic acrylic polymer particles (A) may have a uniform structure or a core / shell type structure, but have excellent color developability and high coating strength. From the viewpoint of forming an excellent ink jet receiving layer, it is preferable to use core-shell type cationic acrylic polymer particles.

  The cationic acrylic polymer particles (A) are dispersed in the form of particles in the aqueous medium (D), and the average particle size is 0.03 to 0.03 from the viewpoint of improving ink absorbability and color developability. A range of 1 μm is preferable, and a range of 0.05 to 0.3 μm is more preferable.

  Moreover, the said cationic acrylic polymer particle (A) may include the silane coupling agent (B) mentioned later. At that time, the silane coupling agent (B) usually exists independently of the cationic acrylic polymer particles (A), but the acrylic polymer particles (A) have a reactive functional group or the like. In this case, a part of the silane coupling agent (B) may be chemically bonded to the acrylic polymer particles (A).

  The cationic acrylic polymer particles (A) can be produced, for example, by the methods shown in the following (1) to (2).

(1) A polymerizable monomer such as a cationic acrylic monomer to be described later, water, a polymerization initiator, and, if necessary, a molecular weight regulator, an emulsifier, a dispersion stabilizer and the like are mixed together to form the polymerizable monomer. A method of polymerizing a monomer.
(2) A liquid mixture of a polymerizable monomer such as a cationic acrylic monomer, water and an emulsifier is dropped into a liquid mixture containing a polymerization initiator and water to polymerize the polymerizable monomer. So-called monomer dropping method.

  The core-shell type cationic acrylic polymer particles usable as the cationic acrylic polymer particles (A) can be produced by the methods shown in the following (3) to (5). However, it is preferable to manufacture by the following method (5).

(3) In the presence of a polymerization initiator and an aqueous medium (D), a cationic group-containing polymer oligomer or a cationic group-containing polymer polymer, which will be described later, is produced in advance, and then other polymerizable monomers and polymerizations are produced. A shell part made of the cationic group-containing polymer by polymerizing the other polymerizable monomer by batch mixing an initiator and, if necessary, a molecular weight adjusting agent and the like and a mixed solution containing the oligomer and the like. And a method for producing cationic acrylic polymer particles having a core portion made of other polymer.
(4) In the presence of a polymerization initiator and an aqueous medium (D), a cationic group-containing polymer oligomer or a cationic group-containing polymer polymer, which will be described later, is produced in advance, and then other polymerizable monomers and polymerizations are produced. It consists of the shell part which consists of the said cationic group containing polymer, and another polymer by dripping the liquid mixture of an initiator and a molecular weight modifier etc. in the liquid mixture containing the said oligomer etc. as needed. A method for producing cationic acrylic polymer particles having a core part.
(5) In the presence of a polymerization initiator and an aqueous medium (D), a cationic group-containing polymer oligomer or a cationic group-containing polymer polymer, which will be described later, is produced in advance, and then other polymerizable monomers are used. By mixing with a mixed liquid containing the oligomer and the like, the oligomer and the like are swollen with the other polymerizable monomer, and further, a polymerization initiator is further mixed to polymerize the other polymerizable monomer. A method for producing a cationic acrylic polymer particle having a shell part made of the cationic group-containing polymer and a core part made of another polymer.

  When manufacturing the said cationic acrylic polymer particle (A), you may use the well-known emulsifier in the range which does not inhibit the effect of this invention, for example including the emulsifier which has a cationic group. However, it is preferable not to use an emulsifier from the viewpoint of suppressing the foaming of the ink jet receiving layer of the present invention and ensuring the long-term storage stability of the printed image when producing the ink jet recording medium of the present invention.

  The temperature at which the cationic acrylic polymer particles (A) are produced by the method as described above varies depending on the type of polymerizable monomer used, the type of polymerization initiator, and the like, but a temperature range of 30 to 90 ° C. It is preferable to carry out with.

  As a polymerizable monomer that can be used when the cationic acrylic polymer particles (A) are produced, for example, a cationic group-containing acrylic monomer can be used. Specifically, an acrylic monomer having a tertiary amino group or a salt thereof, and a monomer having a quaternary ammonium base can be used.

Examples of the acrylic monomer having a tertiary amino group or a base thereof include di-C _1-4 alkylamino-C _2-3 alkyl (meth) acrylamide or a salt thereof, and di-C _1-4 alkylamino-C. _2-3 alkyl (meth) acrylate or a salt thereof can be used.

Examples of the di-C _1-4 alkylamino-C _2-3 alkyl (meth) acrylamide or a salt thereof include dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, and diethylaminopropyl. (Meth) acrylamide or a salt thereof can be used.

Examples of the di-C _1-4 alkylamino-C _2-3 alkyl (meth) acrylate or a salt thereof include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, Diethylaminopropyl (meth) acrylate or a salt thereof can be used.

Examples of the acrylic monomer having a quaternary ammonium base include tri-C _1-4 alkylamino-C _2-3 alkyl (meth) acrylamide salts and tri-C _1-4 alkylamino-C _2-3. A salt such as alkyl (meth) acrylate can be used.

Examples of the salt of tri-C _1-4 alkylamino-C _2-3 alkyl (meth) acrylamide include, for example, a salt of trimethylaminoethyl (meth) acrylamide, a salt of triethylaminoethyl (meth) acrylamide, and a trimethylaminopropyl (meth) Acrylamide salts, triethylaminopropyl (meth) acrylamide salts, and the like can be used.

Examples of the salt of tri C _1-4 alkylamino-C _2-3 alkyl (meth) acrylate include, for example, a salt of trimethylaminoethyl (meth) acrylate, a salt of triethylaminoethyl (meth) acrylate, trimethylaminopropyl ( A salt of meth) acrylate, a salt of triethylaminopropyl (meth) acrylate, or the like can be used.

As a counter ion constituting the salt structure of the tri-C _1-4 alkylamino-C _2-3 alkyl (meth) acrylamide salt or the tri-C _1-4 alkylamino-C _2-3 alkyl (meth) acrylate salt Are, for example, halide ions (chloride ions, bromide ions, etc.), sulfate ions, alkyl sulfate ions (methyl sulfate ions, ethyl sulfate ions, etc.), alkyl sulfonate ions, aryl sulfonate ions, carboxylate ions (acetate ions, etc.) And the like.

  The cationic acrylic polymer particles (A) are prepared by polymerizing an acrylic monomer having a tertiary amino group by the above-described method, and then, for example, an alkylating agent such as epichlorohydrin, methyl chloride, benzyl chloride, and the like. Alternatively, a quaternary ammonium salt may be formed by reacting with the tertiary amino group of the obtained acrylic polymer.

In addition to the above-mentioned cationic group-containing acrylic monomer, examples of the polymerizable monomer that can be used for producing the cationic acrylic polymer particles (A) include di-C _1-4 alkylamino. —C _2-3 alkyl group-substituted aromatic vinyl or a salt thereof, a nitrogen-containing heterocyclic monomer or a salt thereof, and the like can be used.

Examples of the di-C _1-4 alkylamino-C _2-3 alkyl group-substituted aromatic vinyl or a salt thereof include 4- (2-dimethylaminoethyl) styrene, 4- (2-dimethylaminopropyl) styrene, and the like. Or the like can be used.

  Moreover, as said nitrogen-containing heterocyclic monomer or its salt, vinyl pyridine, vinyl imidazole, vinyl pyrrolidone, or these salts etc. can be used, for example.

  The amount of the cationic monomer used can be selected within a range that does not impair the physical properties of the resin composition for forming an ink jet receiving layer of the present invention, but the polymerization used when the cationic acrylic polymer (A) is produced. 1-10 mass parts is preferable with respect to 100 mass parts of an ionic monomer, More preferably, it is 3-8 mass parts.

  As a monomer used when producing the cationic acrylic polymer (A), in addition to the cationic group-containing acrylic monomer as described above, other polymerizable monomer may be used as necessary. Can be used together.

  Examples of the other polymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, dicyclo (Meth) acrylic acid esters such as pentanyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate; 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3- Pentafluoro Fluorine-containing (meth) such as propyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, β- (perfluorooctyl) ethyl (meth) acrylate Acrylic esters; Vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl versatic acid; Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, amyl vinyl ether, hexyl vinyl ether; Nitrile group-containing polymerizable monomers such as acrylonitrile; aromatics such as styrene, α-methylstyrene, vinyltoluene, vinylanisole, α-halostyrene, vinylnaphthalene, divinylstyrene Vinyl compounds having; isoprene, chloroprene, butadiene, ethylene, tetrafluoroethylene, vinylidene fluoride, N- vinylpyrrolidone and the like can be used singly or in combination.

  Examples of the other polymerizable monomer include hydroxyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and glycerol mono (meth) acrylate. (Meth) acrylic acid esters; amide group-containing polymerizable monomers such as (meth) acrylamide, N-monoalkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide; dicyclopentenyl (meth) acrylate, etc. Cyclopentenyl group-containing polymerizable monomers; allyl group-containing polymerizable monomers such as allyl (meth) acrylate can be used.

  As the other polymerizable monomer, for example, a polyfunctional polymerizable monomer having two or more polymerizable groups can be used. For example, ethylene glycol di (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, diallyl phthalate, divinylbenzene, allyl ( A (meth) acrylate etc. can be used.

  In addition, when the cationic acrylic polymer particles (A) are produced, it is possible to use a crosslinkable monomer in addition to the above-described various monomers, and the resulting coating strength of the ink jet receiving layer can be further increased. Since it improves, it is preferable.

  The crosslinkable monomer is a monomer having a self-crosslinkable or reactive functional group, for example, a hydrolyzable group-containing crosslinkable monomer having a crosslinkable group represented by the following general formula [I]. The body can be used. Cationic acrylic polymer particles obtained by using a hydrolyzable condensable group-containing crosslinkable monomer having a crosslinkable group represented by the following general formula [I] are bonded to a part of the filler (C) described later. By doing so, it is possible to suppress the filler (C) from falling off from the ink jet receiving layer. Therefore, it is preferable to use a hydrolyzable condensable group-containing crosslinkable monomer having a crosslinkable group represented by the following general formula [I] as the crosslinkable monomer. In addition, the alkoxysilyl group represented by the following general formula [I] may be hydrolyzed and exist in the form of a silanol group.

（式［I］中、Ｒ_１は水素原子、アルキル基、アリール基及びアラルキル基からなる群より選ばれる一種の一価の有機残基を、Ｒ_２はハロゲン原子、アルコキシル基、アシロキシ基、フェノキシ基、イミノオキシ基、アルケニルオキシ基及び水酸基からなる群より選ばれる一種の官能基を表し、また、ｎは０、１又は２なる整数を表す。）

(In the formula [I], R ₁ represents a monovalent organic residue selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and an aralkyl group; R ₂ represents a halogen atom, an alkoxyl group, an acyloxy group, a phenoxy group; A functional group selected from the group consisting of a group, an iminooxy group, an alkenyloxy group and a hydroxyl group, and n represents an integer of 0, 1 or 2.)

  Specific examples of the hydrolysis-condensable group-containing crosslinking monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethoxydimethylsilane, vinylethoxydimethylsilane, vinylisobutoxydimethylsilane, Vinyldimethoxymethylsilane, vinyldiethoxymethylsilane, vinyltris (β-methoxyethoxy) silane, vinyldiphenylethoxysilane, vinyltriphenoxysilane, γ- (vinylphenylaminopropyl) trimethoxysilane, γ- (vinylbenzylaminopropyl) Trimethoxysilane, γ- (vinylphenylaminopropyl) triethoxysilane, γ- (vinylbenzylaminopropyl) triethoxysilane, divinyldimethoxysilane, divinyldiethoxysilane, di Vinyldi (β-methoxyethoxy) silane, vinyldiacetoxymethylsilane, vinyltriacetoxysilane, vinylbis (dimethylamino) methylsilane, vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyltrichlorosilane, vinylmethylphenylchlorosilane, allyltriethoxysilane, 3-allylaminopropyltrimethoxysilane, allyldiacetoxymethylsilane, allyltriacetoxysilane, allylbis (dimethylamino) methylsilane, allylmethyldichlorosilane, allyldimethylchlorosilane, allyltrichlorosilane, methacrylphenyldichlorosilane, β- (meth) Acryloxyethyltrimethoxysilane, β- (meth) acryloxyethyltriethoxysilane, γ- (meth) acryloxyp Pyrtrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldichlorosilane, γ- (meth) acryloxypropyltris (Β-methoxyethoxy) silane or the like can be used, and it is more preferable to use γ-methacryloxypropyltrimethoxysilane from the viewpoint of easy availability.

Further, as the crosslinkable monomer, in addition to those described above, glycidyl (meth) acrylate, (meth) allyl glycidyl ether, 1-allyloxy-3,4-epoxybutane, 1- (3-butenyloxy) -2, Epoxy group-containing crosslinkable monomers such as 3-epoxypropane and 4-vinyl-1-cyclohexene-1,2-epoxide, and N-C such as N-methylol (meth) acrylamide and N-methoxymethyl (meth) acrylamide _1-4 methylol group-containing cross-linkable monomers such as alkoxymethyl (meth) acrylamide and N-butyrol (meth) acrylamide or derivatives thereof, (meth) acrylic acid 2- (1-aziridinyl) ethyl, (meth) acrylic 2- (1-aziridinyl) propyl acid, 3- (1-aziridinyl) propyl (meth) acrylate, etc. Diridinyl group-containing crosslinkable monomers; (meth) acryloyl isocyanate, isocyanate groups such as phenol or methyl ethyl ketoxime adduct of (meth) acryloyl isocyanate ethyl and / or blocked isocyanate group-containing crosslinkable monomers; Oxazoline group-containing crosslinking monomers such as 2-isopropenyl-2-oxazoline and 2-vinyl-2-oxazoline; Carbonyl group-containing crosslinking monomers such as acrolein and diacetone (meth) acrylamide; Acetoacetoxyethyl (meta ) An acetoacetyl group-containing cross-linkable monomer such as an acrylate can be used.

  Moreover, the said crosslinkable monomer is the range of 0.1-5 mass parts with respect to 100 mass parts of whole quantity of the polymerizable monomer used when manufacturing the said cationic acrylic polymer particle (A). Is preferably within the range of 0.2 to 2 parts by mass.

  Moreover, as a polymerization initiator which can be used when manufacturing the said cationic acrylic polymer particle (A), a radical polymerization initiator can be used, for example.

  Examples of the radical polymerization initiator include diacyl peroxides such as benzoyl peroxide, lauroyl peroxide and decanoyl peroxide, dialkyl peroxides such as t-butylcumyl peroxide and dicumyl peroxide, and t-butyl peroxide. Peroxyesters such as oxylaurate, t-butyl peroxybenzoate, organic peroxides such as cumene hydroperoxide, paramentane hydroperoxide, hydroperoxide such as t-butyl hydroperoxide, persulfuric acid Persulfates such as potassium, sodium persulfate and ammonium persulfate, hydrogen peroxide and the like can be used alone or in combination of two or more.

  The radical polymerization initiator described above includes ascorbic acid and salts thereof, erythorbic acid and salts thereof, tartaric acid and salts thereof, citric acid and salts thereof, metal salts of formaldehyde sulfoxylate, sodium thiosulfate, sodium bisulfite, chloride It can also be used as a redox polymerization initiator in combination with a reducing agent such as ferric iron. As the polymerization initiator, an azo initiator such as 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-amidinopropane) dihydrochloride can be used. .

  Further, when producing the cationic acrylic polymer particles (A), if necessary, a compound having chain transfer ability as a molecular weight modifier, such as lauryl mercaptan, octyl mercaptan, dodecyl mercaptan, 2-mercaptoethanol, Mercaptans such as octyl thioglycolate, 3-mercaptopropionic acid, thioglycerin, or α-methylstyrene dimer may be used.

Next, the silane coupling agent (B) constituting the resin composition for forming an ink jet receiving layer of the present invention will be described.
The silane coupling agent (B) used in the present invention includes a hydrolyzable alkoxysilyl group or silyl halide group in the molecule and a functional group different from them, such as an amino group, an epoxy group, a vinyl group, an acrylic group, A compound having a methacryl group, an isocyanate group, a quaternary ammonium base, a mercapto group, an alkyl halide group, or the like can be used.
The silane coupling agent (B) is contained in the aqueous medium (D) independently of the cationic acrylic polymer particles (A) and filler (C) in the resin composition for forming an ink-jet receiving layer of the present invention. Or may be bonded to a part of the cationic acrylic polymer particles (A) or the like. Moreover, the said silane coupling agent (B) may be taken in in the said cationic acrylic polymer particle (A).

  Examples of the silane coupling agent (B) include N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane. Ethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, vinyltrimethoxysilane, Vinyltriethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N- (1,3-dimethylbutylidene)- 3- Triethoxysilyl) -1-propanamine, N- [2- (vinylbenzylamino) ethyl] 3-aminopropyltrimethoxysilane hydrochloride, N, N′-bis [3- (trimethoxysilyl) propyl] ethylenediamine, 3-isocyanopropyltrimethoxysilane, N-phenyl- [N-3- (trimethoxysilyl) propyl] -N, N-dimethylammonium chloride, N-stearyl- [N-3- (trimethoxysilyl) propyl] -N, N-dimethylammonium chloride or the like may be used alone or in combination of two or more.

  The silane coupling agent (B) has at least one functional group selected from the group consisting of an epoxy group, an amino group, and an isocyanate group from the viewpoint of improving the coating strength of the obtained ink jet receiving layer. It is preferable to use a silane coupling agent.

  The silane coupling agent (B) is 0.01% based on the total amount of the cationic acrylic polymer particles (A) from the viewpoint of maintaining the dispersion stability of the resin composition for forming an ink jet receiving layer of the present invention. It is preferable to use in the range of ˜5% by mass.

Next, the filler (C) used in the resin composition for forming an ink jet receiving layer of the present invention will be described.
Examples of the filler (C) include amorphous silica, aluminum silicate, white carbon, particulate calcium silicate, zeolite, magnesium aminosilicate, calcined siliceous soil, particulate magnesium carbonate, particulate alumina, silica, talc, and kaolin. Mineral powders such as delaminated kaolin, clay, heavy calcium carbonate, light calcium carbonate, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, magnesium silicate, calcium sulfate, sericite, bentonite, smectite Inorganic pigments such as granules, cross-linked or non-cross-linked organic fine particles such as polystyrene resin, acrylic resin, urea resin, melamine resin, and benzoguanamine resin, organic pigments such as fine hollow particles, plastic pigments, etc. It can be used. Among these, the use of amorphous silica, alumina, hydrated alumina sol, colloidal silica, and colloidal alumina is from the viewpoint of improving ink absorbability and color developability, and improving the coating strength of the resulting inkjet receiving layer. Particularly preferred.

  The filler (C) is preferably used in a range of 100 to 4000 parts by weight, and in a range of 100 to 3000 parts by weight, with respect to 100 parts by weight of the total amount of the cationic acrylic polymer particles (A). Is more preferable. Within such a range, an ink jet receiving layer having excellent ink absorbability and coating strength can be formed.

  Moreover, as an aqueous medium (D) used for the resin composition for inkjet receiving layer formation of this invention, polar solvents, such as water and the organic solvent mixed with water, can be specifically used.

  Examples of the organic solvent miscible with water include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; propylene glycol monomethyl ether; Alkyl ethers of polyalkylene glycols such as tetraethylene glycol monobutyl ether, and acetates thereof; amides such as N-methyl-2-pyrrolidone can be used.

  As the aqueous medium (D), only water may be used, or a mixture of water and an organic solvent miscible with water may be used. As the aqueous medium, it is preferable to use only water or a mixture of water and an organic solvent miscible with water from the viewpoint of safety and environmental load, and it is particularly preferable to use only water.

  In order to improve the dispersion stability of the filler (C) and to improve the fixing property of the ink to the obtained ink jet receiving layer, the resin composition for forming an ink jet receiving layer of the present invention contains a water-soluble cationic group. It is preferable to use the resin (E) in combination.

  The cationic group-containing water-soluble resin (E) is not limited as long as it is a water-soluble resin that dissociates and exhibits cationic properties when dissolved in the aqueous medium (D). For example, polyethyleneimine, Polyvinylpyridine, polyamine sulfone, polyvinylamidine, polydialkylaminoethyl methacrylate, polydialkylaminoethyl acrylate, polydialkylaminoethyl methacrylamide, polydialkylaminoethyl acrylamide, polyepoxyamine, polyamidoamine, dicyandiamide-formalin condensate, dicyandiamide polyalkyl -Polyalkylene polyamine condensates, compounds such as polyvinylamine, polyallylamine and their hydrochlorides, polydiallyldimethylammonium chloride and acrylamides thereof Copolymer, polydiallylmethylamine hydrochloride, polymethacrylic acid ester methyl chloride quaternary salt and other resins having primary to tertiary amine groups or quaternary ammonium bases, cationic modified polyvinyl alcohol, cationic group-containing water-soluble Acrylic resin, cation-modified starch, neutralized salt of chitosan, and the like can be used. Among them, polydiallyldimethylammonium chloride is more preferably used from the viewpoint of improving ink absorbability and color developability.

  The cationic group-containing water-soluble resin (E) is preferably used in the range of 1 to 50 parts by mass, and in the range of 1 to 20 parts by mass, with respect to 100 parts by mass of the filler (C). From the viewpoint of improving the dispersion stability of the filler (C), it is more preferable.

  The resin composition for forming an ink jet receiving layer of the present invention contains a water soluble resin (F) other than the cationic group-containing water soluble resin (E) in order to further improve the coating strength of the ink jet receiving layer. Are also preferably used in combination.

  The water-soluble resin (F) is a resin that can take a form completely dissolved in water. For example, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetal, polyalkylene oxide, starch, methyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, hydroxypropyl Cellulose derivatives such as methyl cellulose and carboxymethyl cellulose, polyamides, modified products thereof, and the like can be used. In particular, it is preferable to use polyvinyl alcohol as the water-soluble resin (F) because the binder strength with respect to the filler (C) is particularly good and the coating strength of the formed inkjet receiving layer can be improved.

  The polyvinyl alcohol can impart properties necessary for the formation of an inkjet receiving layer, such as transparency, coating film strength, binder power to fillers, and is easily available, and is rich in types of modified products, Conventionally, it is used for the resin composition for inkjet receiving layer formation.

  The polyvinyl alcohol having any degree of polymerization can be used, but has a degree of polymerization in the range of 500 to 5000 from the viewpoint of improving the binder strength against the filler (C) and the coating strength of the ink jet receiving layer. Those having a degree of polymerization in the range of 1500 to 5000 are more preferable.

  Polyvinyl alcohol is generally obtained by hydrolyzing an acetyl group portion of a vinyl acetate polymer with a strong base such as sodium hydroxide to form a hydroxyl group (saponification). As polyvinyl alcohol, those having various saponification ratios (saponification degree) and those having various polymerization degrees are commercially available.

  As said polyvinyl alcohol, it is preferable to use the polyvinyl alcohol which has a saponification degree of the range of 80 mol%-99.9 mol% from a viewpoint of improving the film strength of an inkjet receiving layer, and 85 mol%-99.99. More preferably, polyvinyl alcohol having a saponification degree in the range of 9 mol% is used.

  Moreover, as the polyvinyl alcohol, modified polyvinyl alcohol having various modifying groups can be used. Examples of the modifying group include acetoacetyl group, silyl group, quaternary ammonium base, carboxylic acid group, carboxylic acid group, sulfonic acid group, sulfonic acid group, ketone group, mercapto group, amino group, ethylene group and the like. . These can be introduced into polyvinyl alcohol by copolymerizing vinyl acetate and the monomer having the modifying group.

  Next, the manufacturing method of the resin composition for inkjet receiving layer formation of this invention is demonstrated.

  The resin composition for forming an inkjet receiving layer of the present invention includes, for example, an aqueous dispersion of the cationic acrylic polymer particles (A), the silane coupling agent (B), the filler (C), and the aqueous medium (D ) And, if necessary, other components such as the cationic group-containing water-soluble resin (E) and the water-soluble resin (F).

  Moreover, since the cationic group-containing water-soluble resin (E) contributes to the dispersion stability of the filler (C) as described above, the filler (C) and the cationic group-containing water-soluble resin (E) are previously added. It is preferable to manufacture the resin composition for forming an ink-jet receiving layer by mixing those dispersed and dissolved in an aqueous medium and other components.

  In addition, the silane coupling agent (B), the cationic group-containing water-soluble resin (E), and the water-soluble resin (F) may each be dispersed or dissolved in an aqueous medium.

  Further, the silane coupling agent (B) is incorporated into the cationic acrylic polymer particles (A) by being used in advance when the aqueous dispersion of the cationic acrylic polymer particles (A) is produced. It may be.

  When manufacturing the said resin composition for inkjet receiving layer formation, a stirrer and a disperser can be used as needed. As the stirrer, for example, a stirrer having a turbine blade, a propeller blade, a fiddler blade, a paddle blade, an anchor blade, a max blend blade, a ribbon blade, a disper blade, and the like can be used. Further, as the disperser, for example, various homogenizers, bead mills, sand mills, line mills, colloid mills, and the like can be used.

The inkjet receiving layer forming resin composition of the present invention, relative to the cationic acrylic polymer particles (A) 100 parts by mass of the filler (C) one containing 100 to 4000 parts by weight is preferred. Moreover, what contains 0.01-5 mass parts of said silane coupling agents (B) is more preferable.
In addition, the said aqueous medium (D) can be suitably adjusted so that the non volatile matter of the resin composition for inkjet receiving layer formation may be 5-40 mass%.
As described above, according to the resin composition for forming an ink jet receiving layer having the above-described blending ratio, it is possible to form an ink jet receiving layer having excellent ink absorbability and color developability and having a tough coating film strength.

  The resin composition for forming an ink-jet receiving layer of the present invention may contain various additives as necessary within a range not impairing the effects of the present invention.

  Examples of the additive include various cross-linking agents such as boric acid, zirconium-based, epoxy-based, isocyanate-based, melamine-based, and carbodiimide-based materials, pigment dispersants, ultraviolet absorbers, antioxidants, antistatic agents, and extinguishing agents. A foaming agent and various leveling agents such as nonionic, cationic, anionic and amphoteric hydrocarbons, silicones, fluorines and acetylenic diols can be used.

  Although the usage-amount of the said additive will not be specifically limited if it is a range which does not impair the effect of this invention, It is the range of 0.01-30 mass% with respect to the non volatile matter whole quantity of the resin composition for inkjet receiving layer formation. It is preferable.

  In addition, the resin composition for forming an ink-jet receiving layer of the present invention is a known resin other than those described above that can be dispersed in the aqueous medium (D) within a range not impairing the effects of the present invention, such as vinyl acetate, ethylene, and the like. Synthetic rubbers such as vinyl acetate, acrylic, epoxy, polyester, polyamide, urethane, styrene / butadiene, acrylonitrile / butadiene, and acrylic / butadiene may also be included.

  The resin composition for forming an ink jet receiving layer can be used as an ink jet receiving agent that can be used for forming an ink jet receiving layer of an ink jet recording medium.

  The ink jet receiving agent of the present invention preferably has a viscosity in the range of 5 mPa · s to 100,000 mPa · s from the viewpoint of storage stability and efficiency of application to various substrates and impregnation workability.

Next, the ink jet recording medium of the present invention will be described.
The ink jet recording medium of the present invention is an ink jet receiving layer formed on a substrate by volatilizing an aqueous medium (D) contained in the ink jet receiving agent after coating or impregnating the ink jet receiving agent on various substrates. Is formed, and is excellent in ink absorbability, color developability, and coating strength of the ink jet receiving layer. Therefore, the ink jet recording medium of the present invention is particularly useful as a photographic ink jet recording medium.

  The ink jet recording medium of the present invention preferably has an ink jet receiving layer having a thickness in the range of 3 μm to 50 μm in order to maintain the properties such as ink absorbability at a practical level and maintain good production efficiency. Considering the ink absorbability and the coating strength of the inkjet receiving layer, those having an inkjet receiving layer with a thickness in the range of 5 μm to 30 μm are more preferable.

  Examples of the base material that can be used in the production of the inkjet recording medium of the present invention include paper, paperboard, resin-coated paper, various plastic films, synthetic paper, fiber, non-woven fabric, spunbond, woven fabric such as artificial leather and natural leather. And a non-woven fabric impregnated and / or coated with a resin.

  As a method for coating or impregnating the ink jet receiving agent onto the substrate, a known and commonly used method can be used, and is not particularly limited. For example, an air knife coater, a blade coater, a roll coater, a gravure coater, a comma coater A method using a coating machine such as a gate roll coater is simple.

  The method for volatilizing the aqueous medium (D) contained in the receiving agent after coating the inkjet receiving agent of the present invention on the substrate is not particularly limited. For example, a dryer is used. The drying method is generally used. The drying temperature may be a temperature that can volatilize the aqueous medium (D) and does not adversely affect the substrate.

  Moreover, when applying the conventional inkjet receiving agent on a base material etc., in order to prevent generation | occurrence | production of the said crack, the process of repeating a low temperature drying process and coating several times etc. was required, for example. However, since the ink jet receiving agent of the present invention is less likely to cause cracks in the ink jet receiving layer formed when coated or impregnated on a substrate, according to the ink jet receiving agent of the present invention, as described above. A process is unnecessary, and the production efficiency of the ink jet recording medium can be improved.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

[Synthesis Example 1] Preparation of emulsion (AI) of cationic acrylic polymer particles.
A condenser, thermometer, and dropping funnel were attached to a stainless steel reaction vessel (2 liters) with a stirrer, and the air inside the vessel was replaced with nitrogen. Then, 20 parts by mass of methacryloxyethyltrimethylammonium chloride, 0.6 mass of n-dodecyl mercaptan Part, 2 parts by mass of ammonium persulfate, and 540 parts by mass of deionized water were added, the internal temperature was raised to 80 ° C. while stirring, and the mixture was allowed to react at the same temperature for 45 minutes to obtain a mixture (a).

  Next, the mixture (a) adjusted to 70 ° C. and a monomer mixture previously mixed in another container (212 parts by mass of butyl acrylate, 180 parts by mass of methyl methacrylate, 8 parts by mass of glycidyl methacrylate, γ- 1.2 parts by mass of a polymerization catalyst (5% 2,2′-azobis (2-methylpropionamidine) dihydrochloride) is added dropwise to a mixture of methacryloxypropyltrimethoxysilane (0.8 parts by mass) for 180 minutes. And copolymerized. The copolymerization was performed at 80 ° C.

  After completion of the dropwise addition, the contents were stirred for 1 hour, then cooled to 25 ° C., adjusted to pH 5-6 with aqueous ammonia, and adjusted with deionized water to a non-volatile content of 40% by weight. An emulsion (AI) of coalesced particles was obtained.

[Synthesis Example 2] Preparation of emulsion (A-II) of cationic acrylic polymer particles.
A cationic acrylic polymer particle emulsion (A-II) was obtained in the same manner as in Synthesis Example 1 except that γ-methacryloxypropyltrimethoxysilane was not used.

[Production Example 1] Preparation of silica dispersion.
In advance, 480 parts by mass of water and 33 parts by mass of a 52% by mass aqueous solution of polydiallyldimethylammonium chloride were mixed, and then dry silica [silica specific surface area: 300 m ² / g, average particle diameter of primary particles: 7 nm, (Specific gravity: 50 g / l) 87 parts by mass were sufficiently mixed using a stirrer equipped with a propeller blade to produce a silica dispersion having a nonvolatile content of 17% by mass.

[Example 1]
In accordance with the blending amount described in Table 1 below, 3-glycidoxypropyltrimethoxysilane was mixed with the cationic acrylic polymer particle emulsion (AI), and then the mixture and PVA145H [manufactured by Kuraray Co., Ltd., By sufficiently mixing an 8% by mass aqueous solution of polyvinyl alcohol having a saponification degree of 99.5% and a polymerization degree of 4500 with the silica dispersion described in Production Example 1 using a stirrer equipped with a propeller blade, A resin composition (G-1) for forming an ink-jet receiving layer having a nonvolatile content of 15% by mass was prepared.

  The obtained resin composition for forming an ink-jet receiving layer (G-1) was applied onto an easily adhesive-treated transparent polyethylene terephthalate film (A-4100, manufactured by Toyobo Co., Ltd.) using an applicator. By drying at 60 ° C. for 3 minutes, an inkjet recording medium having an inkjet receiving layer having a thickness of 14 μm was produced.

[Example 2]
For forming an inkjet receiving layer in the same manner as in Example 1 except that the same amount of the cationic acrylic polymer emulsion (A-II) is used instead of the cationic acrylic polymer emulsion (AI). A resin composition (G-2) was obtained. Further, an inkjet recording medium was produced in the same manner as in Example 1 except that the resin composition for forming an inkjet receiving layer (G-2) was used instead of the resin composition (G-1).

[Comparative Example 1]
An ink jet receiving layer forming resin composition (G′-3) was obtained in the same manner as in Example 1 except that 3-glycidoxypropyltrimethoxysilane was not used. Further, an ink jet recording medium was produced in the same manner as in Example 1 except that the resin composition for forming an ink jet receiving layer (G′-3) was used instead of the resin composition (G-1).

[Comparative Example 2]
Instead of the cationic acrylic polymer particle emulsion (A-I), the same amount of the cationic acrylic polymer emulsion (A-II) was used, and 3-glycidoxypropyltrimethoxysilane was not used. In the same manner as in Example 1, a resin composition for forming an ink jet receiving layer (G′-4) was prepared. Further, an ink jet recording medium was produced in the same manner as in Example 1 except that the resin composition for forming an ink jet receiving layer (G′-4) was used instead of the resin composition (G-1).

[Comparative Example 3]
Resin composition for forming an ink jet receiving layer (G′-5) in the same manner as in Example 1 except that the emulsion (AI) of cationic acrylic polymer particles and 3-glycidoxypropyltrimethoxysilane were not used. ) Further, an ink jet recording medium was produced in the same manner as in Example 1 except that the resin composition for forming an ink jet receiving layer (G′-5) was used instead of the resin composition (G-1).

[Evaluation method of printing characteristics]
For each inkjet recording medium, PIXUS iP8600, an inkjet printer manufactured by Canon Inc., was used for printing with dye ink. The printed image is a 100% solid image of each color of cyan (hereinafter abbreviated as C), magenta (hereinafter abbreviated as M), yellow (hereinafter abbreviated as Y), and black (hereinafter abbreviated as Bk). Printed. The color density of each solid image obtained was measured using a reflection color density meter made by Gretag Macbeth. In addition, a solid image of 100% of each color of C, M, Y, and Bk is printed in a solid image of 100% Y, and the ink absorbency of the 100% solid image portion and the presence or absence of bleeding are visually observed. evaluated.
The color developability and the like of a printed image can be greatly improved by improving the color density by about 0.05. Further, when comparing a plurality of printed images having different color densities of about 0.05 to 0.1, it is possible to confirm the quality of the color developability even visually.

[Ink absorbency]
○ ・ ・ ・ Absorbs well and is excellent △ ・ ・ ・ Almost absorbs × ・ ・ ・ Does not absorb, overflows ink, has problems in practical use

[Smear]
○… Excellent without blurring △ ・ ・ ・ Good with almost no blurring × ・ ・ ・ Breaking occurs and there are practical problems

[Coating strength]
A peeling test with a mending tape was performed and visually evaluated.
○ ・ ・ ・ No peeling of coating film △ ・ ・ ・ There is little peeling of coating film × ・ ・ ・ Peeling of coating film completely

As is apparent from Table 3, the ink jet recording media obtained in the examples are excellent in ink absorbability, color developability, and coating film strength. On the other hand, the ink jet recording medium obtained by the comparative example is inferior in terms of the coating strength of the ink jet receiving layer, the color developability, and the like as compared with the examples.

Claims (9)

A resin composition for forming an ink-jet receiving layer, comprising cationic acrylic polymer particles (A), a silane coupling agent (B), a filler (C), and an aqueous medium (D). The resin composition for forming an inkjet receiving layer according to claim 1, wherein the cationic acrylic polymer particles (A) have a structural unit (a) represented by the general formula [I].

(In the formula [I], R ₁ represents a monovalent organic residue selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and an aralkyl group; R ₂ represents a halogen atom, an alkoxyl group, an acyloxy group, a phenoxy group; A functional group selected from the group consisting of a group, an iminooxy group, an alkenyloxy group and a hydroxyl group, and n represents an integer of 0, 1 or 2.) The resin composition for forming an ink jet receiving layer according to claim 1, wherein the silane coupling agent (B) is contained in an amount of 0.01 to 5% by mass with respect to the total amount of the cationic acrylic polymer particles (A). The resin composition for forming an ink jet receiving layer according to claim 1, wherein the filler (C) is at least one selected from the group consisting of silica, alumina, and hydrated alumina sol. Furthermore, the resin composition for inkjet receiving layer formation of Claim 1 formed by containing cationic group containing water-soluble resin (E). The resin composition for forming an inkjet receiving layer according to claim 5, wherein the cationic group-containing water-soluble resin (E) is polydiallyldimethylammonium chloride. Furthermore, the resin composition for inkjet receiving layer formation of Claim 1 or 6 formed by containing water-soluble resin (F) other than the said cationic group containing water-soluble resin (E). An ink jet receiving agent comprising the resin composition for forming an ink jet receiving layer according to claim 1. An ink jet recording medium having an ink jet receiving layer formed by applying the ink jet receiving agent according to claim 8 on a substrate and then drying.