JP6217878B1 - Resin dispersion for water-based inkjet ink - Google Patents

Abstract

[PROBLEMS] To provide a resin dispersion for water-based ink-jet ink capable of satisfying both ink physical properties such as storage stability and ejection property and coating film properties such as gloss, abrasion resistance, water resistance and solvent resistance. To provide a water-based inkjet ink. A methacrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms in excess of 58.5% by mass and less than 96.7% by mass and exceeding 3% by mass is 9.6% by mass. Less than, an emulsion polymer of a monomer mixture comprising 0.1 to 10% by weight of a carboxyl group-containing monomer, 0.1 to 10% by weight of an alkoxysilyl group-containing monomer, and 0.1 to 10% by weight of a surfactant monomer. A resin dispersion for an aqueous inkjet ink, comprising a resin particle and an aqueous medium. [Selection figure] None

Description

  The present invention relates to a resin dispersion for aqueous inkjet ink and an aqueous inkjet ink using the same.

  The aqueous inkjet ink is generally composed of a colorant, water, a hydrophilic organic solvent, and a binder resin. Inks are required to have excellent quality requirements such as storage stability and ejection properties of ink and resistance to printed matter. Of these, binder resins have low viscosity even at high solids when used as inks. Many resin fine particles are used, and aqueous inkjet inks containing various resin fine particles have been reported.

Patent Document 1 discloses an ink composition containing water, a colorant, and acrylic silicon resin fine particles.
Patent Document 2 discloses an ink jet recording liquid containing an emulsion obtained by radical polymerization in the presence of a radical reactive emulsifier, a pigment, and an aqueous medium.
Patent Document 3 discloses an aqueous inkjet recording liquid containing a polymer emulsion obtained by radical polymerization of a radically polymerizable unsaturated monomer having a specific amount of alkoxysilyl group.

  However, in recent years when the use of ink-jet inks has expanded, in addition to the above-mentioned required qualities, demands for quality such as gloss and abrasion resistance have also increased, and the ink-jet inks disclosed in the above-mentioned patent documents have these required qualities. Was not satisfactory.

JP-A-9-235499 JP 2002-294105 A JP 2010-159355 A

  The problems to be solved by the present invention are for water-based inkjet inks that can achieve both ink physical properties such as storage stability and ejection properties and coating film properties such as gloss, abrasion resistance, water resistance, and solvent resistance. The object is to provide a resin dispersion and an aqueous inkjet ink using the same.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using resin particles obtained by emulsion polymerization using a specific monomer composition, and the present invention has been completed. It was.
That is, the present invention is more than 58.5% by mass of the styrene monomer and less than 96.7% by mass, and more than 3% by mass of the (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms. Emulsion polymerization of a monomer mixture comprising less than mass%, carboxyl group-containing monomer 0.1-10 mass%, alkoxysilyl group-containing monomer 0.1-10 mass%, and surfactant monomer 0.1-10 mass% The present invention relates to a resin dispersion for water-based inkjet inks, comprising resin particles as a product and an aqueous medium.

  Further, according to the present invention, the monomer mixture further includes two other functional group-containing monomers: a hydroxyl group-containing monomer, an amide group-containing monomer, a glycidyl group-containing monomer, an oxyalkylene group-containing monomer, and other ethylenically unsaturated bonds. It is related with the said resin dispersion for water-based inkjet inks which contains at least 1 type chosen from the group which consists of the monomer which has the above.

  Moreover, this invention relates to the said resin dispersion for water-based inkjet inks which contains 0.1-10 mass% of said other functional group containing monomers in the said mixture.

  The present invention further relates to the resin dispersion for water-based ink-jet ink comprising an aqueous wax dispersion.

  The present invention also relates to the resin dispersion for aqueous inkjet ink, wherein the aqueous wax dispersion is an aqueous polyolefin wax dispersion.

  The present invention also relates to the resin dispersion for aqueous inkjet ink, wherein the polyolefin wax contained in the aqueous polyolefin wax dispersion has a melting point of 100 to 150 ° C.

  The present invention also relates to an aqueous inkjet ink comprising the resin dispersion for an aqueous inkjet ink and a colorant.

  According to the present invention, a resin dispersion for water-based inkjet inks that can achieve both ink physical properties such as storage stability and ejection properties and coating film properties such as gloss, abrasion resistance, water resistance, and solvent resistance, and the like. The water-based ink-jet ink used can be provided.

  Hereinafter, the present invention will be described in detail, but prior to that, terms used in this specification will be described. “Monomer” means a monomer that is a compound having an ethylenically unsaturated bond. “(Meth) acryl” means acrylic and methacrylic. “(Meth) acrylate” means acrylate and methacrylate. “A (meth) acrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms” means a (meth) acrylic acid alkyl ester in which the alkyl group in the (meth) acrylic acid alkyl ester has 4 to 12 carbon atoms. It does not mean a (meth) acrylic acid alkyl ester in which a part of the (meth) acrylic acid alkyl ester is substituted with an alkyl group having 4 to 12 carbon atoms. “Resin dispersion for water-based inkjet ink” and “water-based inkjet ink” may be abbreviated as “dispersion” and “ink”, respectively.

  The resin dispersion for water-based inkjet inks of the present invention is more than 58.5% by mass of styrene monomer and less than 96.7% by mass, and 3% by mass of (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms. And less than 9.6% by weight, 0.1 to 10% by weight of a carboxyl group-containing monomer, 0.1 to 10% by weight of an alkoxysilyl group-containing monomer, and 0.1 to 10% by weight of a surfactant monomer. A resin dispersion for an aqueous inkjet ink comprising resin particles having an average particle size of 30 to 100 nm, which is an emulsion polymer of the monomer mixture, and an aqueous medium.

<Styrene monomer>
From the viewpoint of high gloss, the styrene monomer is contained in the monomer mixture in an amount of more than 58.5% by mass and less than 96.7% by mass, preferably 80 to 96% by mass.

<(Meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms>
The (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms is contained in the monomer mixture in an amount of more than 3% by mass and less than 9.6% by mass, but 4 to 9.5% by mass. Is preferred. In the monomer mixture, the styrene monomer exceeds 58.5% by mass and less than 96.7% by mass, and the (meth) alkyl acid alkyl ester monomer having 4 to 12 carbon atoms exceeds 3% by mass and less than 9.6% by mass. By including, the glass transition temperature of a polymer can be designed in the range of 20-120 degreeC, and the dispersion excellent in abrasion resistance is obtained. Moreover, since a styrene monomer and a C4-C12 (meth) alkyl acid alkyl ester monomer are both monomers of a hydrophobic skeleton, a dispersion excellent in water resistance can be obtained by including them in the above ratio. .

  Examples of the (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms include butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, Pentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, 3-pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, heptyl (meth) acrylate, 2-heptyl ( (Meth) acrylate, octyl (meth) acrylate, 2-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, do Although such Sil (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t- butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, it is preferable to use dodecyl (meth) acrylate.

<Carboxyl group-containing monomer>
By using a carboxyl group-containing monomer, gloss and ink storage stability are improved. The carboxyl group-containing monomer is contained in the monomer mixture in an amount of 0.1 to 10% by mass, preferably 0.3 to 5% by mass. Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, and cinnamic acid, and acrylic acid is preferably used.

<Alkoxysilyl group-containing monomer>
By using an alkoxysilyl group-containing monomer, wear resistance, water resistance, and solvent resistance are improved. The alkoxysilyl group-containing monomer is contained in the monomer mixture in an amount of 0.1 to 10% by mass, preferably 0.1 to 5% by mass.

  The alkoxysilyl group-containing monomer means a silane compound having an ethylenically unsaturated double bond, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, 3-acryloxypropyl. Trimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, Examples include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, parastyryltrimethoxysilane, parastyryltriethoxysilane, and the like. From the viewpoint of aqueous and abrasion resistance, it is preferable to use an alkoxysilyl group-containing monomer having three alkoxy groups.

<Surfactant monomer>
The surfactant monomer refers to a surfactant having one or more ethylenically unsaturated double bonds capable of radical polymerization in the molecule. By using the surfactant monomer, wear resistance, water resistance and solvent resistance are improved. The surfactant monomer is contained in the monomer mixture in an amount of 0.1 to 10% by mass, preferably 0.3 to 5% by mass. Examples of the surfactant monomer include an anionic surfactant monomer, a cationic surfactant monomer, and a nonionic surfactant monomer, and an anionic surfactant monomer or a nonionic surfactant monomer is preferable. The main skeleton of the anionic surfactant monomer is preferably sulfosuccinate, alkyl ether, alkylphenyl ether, alkylphenyl ester, (meth) acrylate sulfate, and phosphate. The nonionic surfactant monomer preferably has an alkyl ether, alkylphenyl ether, or alkylphenyl ester as the main skeleton.

<Other functional group-containing monomers>
Other functional group-containing monomers are other than the above-mentioned styrene monomer, (meth) acrylic acid alkyl ester monomer having a C 4-12 alkyl group, carboxyl group-containing monomer, alkoxysilyl group-containing monomer, surfactant monomer A monomer having a functional group of The other functional group-containing monomer may include at least one of a hydroxyl group-containing monomer, an amide group-containing monomer, a glycidyl group-containing monomer, an oxyalkylene group-containing monomer, and another monomer having two or more ethylenically unsaturated bonds. preferable. However, in this specification, these monomers are defined as follows. The monomer having two or more ethylenically unsaturated bonds means a monomer having two or more ethylenically unsaturated bonds excluding a hydroxyl group-containing monomer, an amide group-containing monomer, a glycidyl group-containing monomer, and an oxyalkylene group-containing monomer. . An oxyalkylene group-containing monomer means an oxyalkylene group-containing monomer excluding a hydroxyl group-containing monomer, an amide group-containing monomer, and a glycidyl group-containing monomer. A glycidyl group-containing monomer means a glycidyl group-containing monomer excluding a hydroxyl group-containing monomer and an amide group-containing monomer. An amide group-containing monomer means an amide group-containing monomer excluding a hydroxyl group-containing monomer.
It is preferable that 0.1-10 mass% of other functional group containing monomers are contained in a monomer mixture, and it is more preferable that 0.3-8 mass% is contained.

  Other functional group-containing monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, N- (2-hydroxyethyl) Hydroxyl group-containing monomers such as (meth) acrylamide and allyl alcohol;

  (Meth) acrylamide, diacetone (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N- Amide group-containing monomers such as isopropyl (meth) acrylamide and N-butyl (meth) acrylamide;

  Glycidyl group-containing monomers such as glycidyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate glycidyl ether;

  Diethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polyethylene glycol / polypropylene glycol mono (meth) acrylate, methoxydiethylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, phenoxydiethylene glycol mono (meth) acrylate Oxyalkylene group-containing monomers such as phenoxypolyethylene glycol mono (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate;

  Allyl (meth) acrylate, vinyl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri It has two or more other ethylenically unsaturated bonds such as (meth) acrylate, pentaerythritol tetra (meth) acrylate, divinylbenzene, divinyl adipate, diallyl isophthalate, diallyl phthalate, and diallyl maleate. Nomar, and the like.

<Other monomers>
Other monomers include the above-mentioned styrene monomers, (meth) acrylic acid alkyl ester monomers having 4 to 12 carbon atoms, carboxyl group-containing monomers, alkoxysilyl group-containing monomers, surfactant monomers, other functional groups It refers to a monomer other than the contained monomer. Specific examples include (meth) acrylic acid alkyl ester monomers having 1 to 3 or 13 carbon atoms, (meth) acrylic acid alkyl ester monomers having an aliphatic ring and an aromatic ring.

  The methacrylic acid alkyl ester monomer having 1 to 3 or 13 carbon atoms is methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) Examples include acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, icosyl (meth) acrylate, and behenyl (meth) acrylate.

  Examples of the (meth) acrylic acid alkyl ester monomer having an aliphatic ring or an aromatic ring include cyclohexyl (meth) acrylate and benzyl (meth) acrylate.

  Other vinyl group-containing monomers include, for example, α-methylstyrene, vinyl acetate and the like. These monomers can be used alone or in combination of two or more.

<Polymerization initiator and reducing agent>
The emulsion polymerization of the monomer mixture is preferably performed in the presence of a radical polymerization initiator (hereinafter referred to as a polymerization initiator). As the polymerization initiator, a known oil-soluble polymerization initiator or water-soluble polymerization initiator can be used.

  Examples of the oil-soluble polymerization initiator include benzoyl peroxide, t-butyloxybenzoate, t-butyl hydroperoxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxy-3,5,5. , Trimethylhexanoate, di-t-butyl peroxide, cumene hydroperoxide, organic peroxides such as p-menthane hydroperoxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis And azobis compounds such as 2,4-dimethylvaleronitrile, 2,2 ″ -azobis (4-methoxy-2,4-dimethylvaleronitrile), and 1,1′-azobiscyclohexane-1-carbonitrile. It is done.

  Examples of the water-soluble polymerization initiator include ammonium persulfate, sodium persulfate, potassium persulfate, hydrogen peroxide, and 2,2'-azobis (2-methylpropionamidine) dihydrochloride.

  In the polymerization of the monomer mixture, a reducing agent can be used in combination with the polymerization initiator. Thereby, the polymerization reaction can be promoted. Such reducing agents include reducing organic compounds such as metal salts such as ascorbic acid, erythorbic acid, tartaric acid, citric acid, glucose, formaldehyde sulfoxylate, sodium sulfite, sodium bisulfite, sodium metabisulfite (SMBS) And reducing inorganic compounds such as sodium hyposulfite, ferrous chloride, Rongalite and the like.

  For the polymerization of the monomer mixture, a water-soluble polymerization initiator is preferably used. It is preferable that a polymerization initiator uses 0.03-5 mass parts with respect to 100 mass parts of monomer mixtures. The reducing agent is preferably used in an amount of 0.01 to 2.5 parts by mass with respect to 100 parts by mass of the monomer mixture.

  In the emulsion polymerization of the monomer mixture, a buffer, a chain transfer agent, a basic compound and the like can be used as necessary. Examples of the buffer include sodium acetate, sodium citrate, sodium bicarbonate and the like. Examples of the chain transfer agent include octyl mercaptan, t-dodecyl mercaptan, lauryl mercaptan, stearyl mercaptan, 2-ethylhexyl mercaptoacetate, octyl mercaptoacetate, 2-ethylhexyl mercaptopropionate, and octyl mercaptopropionate. From the viewpoint of solvent resistance, when a chain transfer agent is used, it is preferable to use 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the monomer mixture.

  The basic compound is used for neutralization, and examples thereof include alkylamines such as trimethylamine, triethylamine, and butylamine; alcohol amines such as dimethylaminoethanol, diethylaminoethanol, diethanolamine, triethanolamine, and aminomethylpropanol; morpholine, ammonia, and the like. It is done. From the viewpoint of the storage stability of the ink, it is preferable to use an alcohol amine.

<Resin particles>
Resin particles, which are emulsion polymerization products of the monomer mixture, have excellent gloss, dischargeability, and ink storage stability by making the average particle size 30 to 100 nm from the viewpoint of the smoothness of the coating film surface and the viscosity of the dispersion. Water-based inkjet ink is obtained.

<Aqueous wax dispersion>
The aqueous inkjet ink resin dispersion can be further mixed with an aqueous wax dispersion to obtain an aqueous inkjet ink resin dispersion with further improved wear resistance. Examples of the aqueous wax dispersion include aqueous wax dispersions such as polyolefin wax, carnauba wax, silicone wax, urethane wax, and Teflon (registered trademark) wax. From the viewpoint of improving wear resistance, a polyolefin wax dispersion is used. It is preferable. Furthermore, among polyolefin waxes, it is preferable to use a polyethylene wax dispersion. Furthermore, from the viewpoint of improving wear resistance, the melting point of the polyolefin wax is preferably 100 ° C to 150 ° C, more preferably 110 ° C to 140 ° C. From the viewpoint of ejection properties, the average particle size of the aqueous wax dispersion is preferably 10 to 200 nm. In order to achieve both the physical properties of the coating film and the storage stability of the ink, it is preferable that the aqueous wax dispersion is contained in an amount of 1 to 30 parts by mass with respect to 100 parts by mass of the resin particles that are the emulsion polymer of the monomer mixture.

<Water-based inkjet ink>
The aqueous inkjet ink of the present invention contains a resin dispersion for an aqueous inkjet ink and a colorant.

<Colorant>
A pigment is generally used as the colorant. As the pigment, for example, an achromatic pigment such as carbon black, titanium oxide, calcium carbide, or a chromatic organic pigment can be used. Organic pigments include insoluble azo pigments such as toluidine red, toluidine maroon, Hansa echo, benzidine echo, pyrazolone red, soluble azo pigments such as ritole red, heliobordeaux, pigment scarlet, permanent red 2B, alizarin, indanthrone, thioindigo Derivatives from vat dyes such as maroon, phthalocyanine organic pigments such as phthalocyanine blue and phthalocyanine green, quinacridone organic pigments such as quinacridone red and quinacridone magenta, perylene organic pigments such as perylene red and perylene scarlet, isoindolinone yellow , Isoindolinone organic pigments such as isoindolinone orange, pyranthrone organic pigments such as pyranthrone red and pyranthrone orange, thioy Digo-based organic pigments, condensed azo-based organic pigments, benzimidazolone-based organic pigments, quinophthalone-based organic pigments such as quinophthalone yellow, isoindoline-based organic pigments such as isoindoline yellow, and other pigments such as flavanthrone yellow and acylamide yellow Nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, dioxazine violet and the like.

  When organic pigments are exemplified by color index (CI) numbers, C.I. I. Pigment Yellow 12, 13, 14, 17, 20, 24, 74, 83, 8893, 109, 110, 117, 120, 125, 128, 129, 137, 138, 139, 147, 148, 150, 151, 153 154, 155, 166, 168, 180, 185, C.I. I. Pigment orange 16, 36, 43, 51, 55, 59, 61, C.I. I. Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 123, 149, 168, 177, 180, 192, 202, 206, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, C.I. I. Pigment violet 19, 23, 29, 30, 37, 40, 50, C.I. I. Pigment blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 22, 60, 64, C.I. I. Pigment green 7, 36, C.I. I. Pigment brown 23, 25, 26, and the like.

  Specific examples of carbon black include “Special Black 350, 250, 100, 550, 5, 4, 4A, 6” “Printex U, V, 140 U, 140 V, 95, 90, 85, 80, 75, 55, manufactured by Degussa. 45, 40, P, 60, L6, L, 300, 30, 3, 35, 25, A, G ", Cabot's" REGAL 400R, 660R, 330R, 250R "," MOGUL E, L ", Mitsubishi Chemical “MA7, 8, 11, 77, 100, 100R, 100S, 220, 230” “# 2700, # 2650, # 2600, # 200, # 2350, # 2300, # 2200, # 1000, # 990, # 980, # 970, # 960, # 950, # 900, # 850, # 750, # 650, # 52, # 50, # 47, # 45, # 4 5L, # 44, # 40, # 33, # 332, # 30, # 25, # 20, # 10, # 5, CF9, # 95, # 260 ”and the like.

  Specific examples of titanium oxide include “Taipeku CR-50, 50-2, 57, 80, 90, 93, 95, 953, 97, 60, 60-2, 63, 67, 58, 58- manufactured by Ishihara Sangyo Co., Ltd. 2, 85 "" Tipekes R-820, 830, 930, 550, 630, 680, 670, 580, 780, 780-2, 850, 855 "," Tipekes A-100, 220 "," Tipekes W-10 "," Tipekes " PF-740, 744 "" TTO-55 (A), 55 (B), 55 (C), 55 (D), 55 (S), 55 (N), 51 (A), 51 (C) " "TTO-S-1, 2", "TTO-M-1, 2", "Titanics JR-301, 403, 405, 600A, 605, 600E, 603, 805, 806, 701, 800, 808" manufactured by Teika "Titanic EN-1, C, 3, 4, 5 ", and the like manufactured by Du Pont" Taipyua R-900,902,960,706,931 ". Organic pigments such as yellow, magenta, cyan and black are usually used in an amount of 0.2 to 15% by weight, preferably 0.5 to 10% by weight in 100% by weight of the water-based inkjet ink. Moreover, in the case of white titanium oxide, it is preferable to mix | blend in the ratio of 5 to 50 weight% normally, Preferably it is 10 to 45 weight%.

<Aqueous medium>
The aqueous inkjet ink contains an aqueous medium. An aqueous medium refers to water and a hydrophilic organic solvent.

  Examples of the hydrophilic organic solvent include ethylene glycol, 1,3-propanediol, propylene glycol, 1,2-butanediol, 1,4-butanediol, pentylene glycol, 1,2-hexanediol, 1,6. -Glycol solvents such as hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol; methyl glycol, methyl diglycol, methyl triglycol, isopropyl diglycol, butyl glycol, butyl diglycol, butyl triglycol, isobutyl glycol, isobutyl diglycol Glycol, hexyl glycol, hexyl diglycol, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tet Glycol ether solvents such as ethylene glycol dimethyl ether, methyl propylene glycol, methyl propylene diglycol, methyl propylene triglycol, propyl propylene glycol, propyl propylene diglycol; N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, Lactam solvents such as 2-pyrrolidone and ε-caprolactam; formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide And amide solvents such as

  These hydrophilic organic solvents are added as a humectant component and a penetrant component in the ink composition. In addition to lowering the surface tension of the ink, the glycol solvent serves to improve the drying property of the resin dispersion for aqueous inkjet ink. By using a glycol-based solvent, drying of the binder is prevented, nozzle clogging of the resin dispersion for aqueous inkjet ink is prevented, and ejection properties are also improved.

  In addition to reducing the surface tension of the ink itself and improving the wetting and spreading of ink droplets on difficult-to-absorbent substrates, glycol ether solvents can be used to form a resin dispersion for aqueous inkjet inks when drying. Work to promote. By using a glycol ether solvent, the film-forming property of the resin dispersion for aqueous inkjet ink is very excellent, and the coating film properties of the printed matter are good. When these hydrophilic organic solvents are blended, wetting and spreading of the ink droplets on the hardly-absorbable substrate is improved, the dispersion stability of the resin dispersion for aqueous inkjet ink is maintained, and sufficient when drying. Expresses film-forming properties.

 From the viewpoints of printability of the water-based inkjet ink and drying properties, the glycol solvent is preferably contained in an amount of 10 to 40% by mass in 100% by mass of the water-based inkjet ink. In addition, from the viewpoint of water resistance, solvent resistance, abrasion resistance, and dischargeability of the water-based inkjet ink, 0.1 to 15% by mass of an ethylene glycol ether solvent is contained in 100% by mass of the water-based inkjet ink. Preferably, it is in the range of 0.1 to 5% by mass. From the viewpoint of water resistance, solvent resistance, abrasion resistance, and ejection properties of the water-based inkjet ink, the hydrophilic organic solvent as a whole is usually 10 to 60% by mass, preferably 20 to 100% by mass in 100% by mass of the water-based inkjet ink. 50% by mass is used. When blending the water-based inkjet ink, a dispersant, a leveling agent, a preservative, a chelating agent, a pH adjuster, and the like can be blended and used as necessary.

<Printing>
Examples of the substrate on which the water-based inkjet ink of the present invention can be applied or printed include non-penetrating base materials such as penetrating base materials such as fine paper, art paper, coated paper, and polyvinyl chloride sheets. As the printing method, an ink jet method having an on-demand type recording head is preferable. Examples of the on-demand type include a piezo method, a thermal ink jet method, and an electrostatic method, but the piezo method is most preferable. In printing using the water-based inkjet ink of the present invention, a heating and drying process can be introduced into the printing process as necessary for the purpose of reinforcing the drying property and durability of the printed matter. By introducing a heat drying step, film formability may be improved, and an appropriate heat treatment is preferable. The heat treatment step can be used to such an extent that it does not affect the printing step (inkjet printing speed). For example, the heat treatment step is generally carried out at 40 to 100 ° C. for 1 to 200 seconds.

  EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following. Unless otherwise specified, “part” means mass part and “%” means mass%.

<Example 1> Production of resin dispersion for water-based inkjet ink 91 parts of styrene monomer, 5 parts of 2-ethylhexyl acrylate as a (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms, and a carboxyl group-containing monomer 1 part of acrylic acid, 1 part of 3-methacryloxypropyltrimethoxysilane as an alkoxysilyl group-containing monomer, 1 part of 2-hydroxyethyl methacrylate as a hydroxyl group-containing monomer, Latemul PD-104 (manufactured by Kao Corporation, polyoxy) A mixture of 0.4 part of alkylene alkenyl ether ammonium sulfate) and 55 parts of ion-exchanged water was mixed using a homomixer to prepare a monomer pre-emulsion and charged into a dropping tank.
Separately, a four-necked flask equipped with a reflux condenser, a stirrer, a thermometer, a nitrogen inlet tube, and a raw material inlet was used as a reaction vessel, and 90 parts of ion-exchanged water was charged into the reaction vessel. Subsequently, nitrogen was introduced and the liquid temperature was heated to 75 ° C. while stirring. Then, 0.6 part of Latemul PD-104 is added to the reaction vessel, 0.3 part of ammonium persulfate is added, and then the monomer pre-emulsion is continuously dropped over 3 hours from the dropping tank, and emulsion polymerization is performed. Went. After completion of the dropwise addition, the liquid temperature was kept at 80 ° C. for 2 hours, and emulsion polymerization was continued. Then, it cooled to 50 degreeC and the resin dispersion for water-based inkjet inks was obtained by filtering a solution with the filter cloth made from a 180 mesh polyester. The obtained dispersion had a nonvolatile content of 40%, and the acid value of the resin contained in the dispersion was 31 mgKOH / g.

Moreover, the average particle diameter of the resin particles contained in the dispersion obtained above, the glass transition temperature (Tg) of the resin, and the gel fraction of the resin were measured. The Tg and gel fraction of the resin here means the Tg and gel fraction of the resin constituting the resin particles. The average particle diameter of the resin particles is the D ₅₀ average particle diameter measured by a dynamic light scattering measurement method, and a diluted solution obtained by diluting the above dispersion with water 500 times (volume ratio) is measured with Nanotrac (Nikkiso Co., Ltd.). And asked. The Tg of the resin was measured using DSC (Differential Scanning Calorimeter TA Instruments). Specifically, an endothermic peak in a DSC curve obtained by measuring the resin obtained by drying the dispersion under a temperature rising condition of 5 ° C./min was defined as Tg. The resin gel fraction was determined by weighing the resin obtained by drying the dispersion, placing it in a wire mesh, immersing it in tetrahydrofuran at 40 ° C. for 24 hours, weighing the dried mass, Calculated based on
Gel fraction = {(resin mass before immersion) − (resin mass after immersion)} / (resin mass before immersion) × 100

<Water resistance>
The water resistance of the dispersion was evaluated by the following method. The dispersion was applied on a glass plate using an applicator so that the thickness after drying was 40 μm, and dried at 80 ° C. for 1 hour to prepare a coating film. The obtained coating film was put into 40 degreeC warm water, and the state of the coating film after 1 hour was confirmed visually. The evaluation criteria are shown below.
A: No change is observed in the coating film (very good)
○: The coating film is slightly whitened (good)
Δ: Whitening of film (defect)
X: The film peeled off from the glass plate (very bad)

<Machine stability>
The mechanical stability of the dispersion was evaluated by the following method. Using a Maron mechanical stability tester AB-802 manufactured by Tester Sangyo Co., Ltd., measurement was performed under the following conditions.
Resin content: 20%
Amount used: 50 g
Number of revolutions: 1000 rpm (± 20)
Time: 20 minutes Overload: 30kgf
The dispersion after the measurement is filtered with a 100 mesh wire mesh, the dry mass (Wg) of the aggregate on the wire mesh is measured, and the amount (%) of the generated aggregate is obtained by the following formula, based on the following criteria: evaluated.
Amount of generated aggregates (%) = W (g) / [50 (g) × resin content of resin dispersion for aqueous inkjet ink (20%)] × 100
The evaluation criteria are shown below.
○: Less than 0.1% (good)
Δ: 0.1% or more and less than 1.0% (defect)
X: 1.0% or more (very poor)

<Storage stability>
The storage stability of the dispersion was evaluated based on the viscosity change rate by the following method. The initial viscosity was measured immediately after production of the dispersion, then placed in a sealed container, and after 2 weeks at 70 ° C., the viscosity after aging was measured. For the viscosity measurement, a B-type viscometer was used, and measurement was performed under the conditions of 25 ° C. and 30 rpm.
Viscosity change rate (%) = | initial viscosity−viscosity after aging | × 100
The evaluation criteria are shown below.
A: Less than 10% (very good)
○: 10% or more, less than 20% (good)
Δ: 20% or more and less than 50% (defect)
X: 50% or more (very poor)

<Examples 2 to 11 and Comparative Examples 1 to 12> Production of Resin Dispersion for Aqueous Ink-Jet Ink In Example 2 except that the materials and blending compositions shown in Tables 1 and 2 were changed. To 11 and Comparative Examples 1 to 12 were obtained. The numerical values in the table indicate “part” if the unit is not described, and the blank indicates that it is not used.

<Example 12> Preparation of resin dispersion for aqueous inkjet ink While mixing 100 parts of the resin dispersion for aqueous inkjet ink obtained in Example 1 with a disper, 10 parts of AQUACER 507 was blended as an aqueous wax dispersion and dispersed. Got the body.

<Examples 13 to 15> Preparation of Resin Dispersion for Aqueous Ink-jet Inks In the same manner as in Example 12 except that the composition shown in Table 1 was changed, dispersions of Examples 13 to 15 were obtained. The numerical values in the table indicate “part” if the unit is not described, and the blank indicates that it is not used.

Abbreviations in the table are as follows.
St: Styrene <(Meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms>
BA: butyl acrylate BMA: butyl methacrylate 2EHA: 2-ethylhexyl acrylate LMA: lauryl methacrylate (dodecyl methacrylate)
<Carboxyl group-containing monomer>
AA: acrylic acid MAA: methacrylic acid <alkoxysilyl group-containing monomer>
KBM-503: 3-methacryloxypropyltrimethoxysilane KBE-503: 3-methacryloxypropyltriethoxysilane <surfactant monomer>
PD-104: Laterum PD104 (manufactured by Kao Corporation)
SR-10: ADEKA rear soap SR-10 (manufactured by ADEKA)

<Other functional group-containing monomers>
HEMA: 2-hydroxyethyl methacrylate MAAm: methacrylamide GMA: glycidyl methacrylate EGDMA: ethylene glycol dimethacrylate <other monomers>
MMA: Methyl methacrylate EA: Ethyl acrylate

<Aqueous wax dispersion>
AQUACER 507: Polyethylene wax (BYK, melting point: 130 ° C., D ₅₀ : 30 nm)
AQUACER 498: paraffin wax (manufactured by BYK, melting point: 60 ° C., D ₅₀ : 200 nm)
AQUACER 593: Polypropylene wax (BYK, melting point 160 ° C., D ₅₀ : 30 nm)
CERACOL79: Carnauba wax (BYK, melting point 90 ° C., D ₅₀ : 3000 nm)

<Non-polymerizable surfactant>
EO: Emar O (Kao Corporation)

  As can be seen from Tables 1 and 2, the dispersion of the present invention was found to be excellent in water resistance, mechanical stability and storage stability.

<Production of cyan pigment dispersion>
20 parts of pigment (Lionogen Blue 7351 manufactured by Toyocolor Co., Ltd.), 30 parts of pigment dispersion resin (Johncrill 61J manufactured by BASF, 30% solid content aqueous solution), 29.3 parts of ion-exchanged water, and antifoaming agent (Nisshin Chemical Industry Co., Ltd.) Manufactured Surfinol 104E) 0.5 parts was dispersed with a paint conditioner for 2 hours to obtain a concentrated cyan pigment dispersion.

<Manufacture of magenta pigment dispersion>
A concentrated magenta pigment dispersion was obtained in the same manner as the cyan pigment dispersion, except that the pigment was changed to 20 parts (Fastogen Super Magenta RCT manufactured by DIC).

<Manufacture of yellow pigment dispersion>
A concentrated yellow pigment dispersion was obtained in the same manner as the cyan pigment dispersion, except that the pigment was changed to 20 parts (Novoperm Yellow H2G manufactured by Clariant).

<Manufacture of black pigment dispersion>
A concentrated black pigment dispersion was obtained in the same manner as the cyan pigment dispersion, except that the pigment was changed to 20 parts (Printex 85, manufactured by Evonik Degussa).

<Example 16> Preparation of water-based inkjet ink For 10 parts of the solid content of the resin dispersion for water-based inkjet ink obtained in Example 1, 40 parts of the above-mentioned cyan pigment dispersion and 20 parts of glycerin as a hydrophilic organic solvent Then, 40 parts of 1,3-propanediol was added, ion-exchanged water was added so that the solid content was 12%, and kneaded to obtain a cyan water-based inkjet ink. The cyan pigment dispersion was changed to a magenta pigment dispersion, a yellow pigment dispersion, and a black pigment dispersion, respectively, and prepared in the same manner to obtain water-based inkjet inks of various colors.

<Examples 17 to 30 and Comparative Examples 13 to 24> Preparation of water-based inkjet ink Prepared in the same manner as in Example 16 to obtain four-color water-based inkjet ink.

<Evaluation of water-based inkjet ink>
The four-color water-based ink-jet inks prepared above were filled in a solvent ink-jet printer Color Painter 64SPlus manufactured by Seiko Eye Infotech Co., Ltd. under an environment of 25 ° C., and an image was printed on fine paper. About water-based inkjet ink, storage stability and discharge property were evaluated. After printing, the quality paper was dried at room temperature to obtain a printed matter for evaluation. Using this, abrasion resistance, water resistance, solvent resistance, and gloss were evaluated. Tables 3 and 4 show the results.

<Ink storage stability>
The storage stability of the water-based inkjet ink was evaluated based on the viscosity change rate by the following method. Immediately after preparation of the obtained water-based inkjet ink, the initial viscosity was measured, put in a sealed container, and after 2 weeks at 70 ° C., the viscosity after aging was measured. The viscosity was measured using a rheometer (AR Instruments 2000 manufactured by TA Instruments).
Viscosity change rate (%) = | initial viscosity−viscosity after aging | × 100
The evaluation criteria are shown below.
A: Less than 10% (very good)
○: 10% or more, less than 15% (good)
Δ: 15% or more and less than 20% (defect)
×: 20% or more (very poor)

<Dischargeability>
With the above printer, the time until drying and nozzle clogging during printing standby (25 ° C., no ink supplied) was evaluated. The nozzle clogging here refers to a state where ink cannot be printed due to ink clogging during standby. The longer the time until the nozzle clogging occurs, the better the dischargeability. Evaluation criteria are shown below.
A: No nozzle clogging occurs in 120 minutes (very good)
○: No nozzle clogging in 60 minutes (good)
Δ: Nozzle clogging occurs in 30 minutes (defect)
×: Nozzle clogging occurs in 10 minutes (very bad)

<Abrasion resistance>
The printed surface of the printed matter for evaluation (quality paper) is scratched on the printed surface by reciprocating 30 times under the condition of a load of 100 / cm ² (contact surface is high-quality paper) with the Gakushin Abrasion Tester (AB-301 manufactured by Tester Sangyo). Was visually evaluated. Evaluation criteria are shown below.
A: There is no color transfer on the contact surface of the high-quality paper, and there is no scratch on the printed surface (very good)
◯: There is some color transfer on the contact surface of the high-quality paper, but there is no scratch on the print surface (good)
Δ: Color transfer on the contact surface of the high-quality paper, and scratches are seen on the printed surface, but the substrate is not visible (defect)
×: State in which the printed surface has many scratches and the substrate can be seen (very bad)

<Water resistance>
Water was dipped in a cotton swab and the printed surface of the evaluation printed matter (quality paper) was rubbed 10 times. Evaluation criteria are shown below.
A: No ink adhered to the cotton swab (very good)
○: Ink adheres slightly to the cotton swab, but no erosion of the printed surface is observed (good)
Δ: Ink adheres to the cotton swab and erosion of the printed surface is observed, but the surface of the substrate is not visible (defect).
×: Ink adheres to the cotton swab and the surface of the substrate can be seen (very bad)

<Solvent resistance>
Ethanol was immersed in a cotton swab, and the printed surface of the evaluation printed matter (quality paper) was rubbed 10 times. Evaluation criteria are shown below.
A: No ink adhered to the cotton swab (very good)
○: Ink adheres slightly to the cotton swab, but no erosion of the printed surface is observed (good)
Δ: Ink adheres to the cotton swab and erosion of the printed surface is observed, but the surface of the substrate is not visible (defect).
×: Ink adheres to the cotton swab and the surface of the substrate can be seen (very bad)

<Glossy>
The printed surface of the evaluation printed matter was measured for 60 ° gloss with a gloss meter (Nippon Denshoku VG2000). Evaluation criteria are shown below.
○: 60 or more (good)
Δ: 50 or more, less than 60 (defect)
X: Less than 50 (very bad)

  As can be seen from Table 3 and Table 4, the water-based inkjet using the resin dispersion for water-based inkjet inks obtained in Examples 1-15 is more in comparison with the water-based inkjet ink using Comparative Examples 1-12. Ink physical properties such as storage stability and ejection properties, and coating film properties such as gloss, abrasion resistance, water resistance, and solvent resistance were excellent.

Claims (7)

Styrene monomer exceeding 58.5% by mass and less than 96.7% by mass, (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms exceeding 3% by mass and less than 9.6% by mass, carboxyl group Average particle diameter which is an emulsion polymer of a monomer mixture comprising 0.1 to 10% by mass of the monomer containing monomer, 0.1 to 10% by mass of the alkoxysilyl group-containing monomer and 0.1 to 10% by mass of the surfactant monomer A resin dispersion for water-based inkjet inks, comprising resin particles having a diameter of 30 to 100 nm and an aqueous medium.

  The monomer mixture further comprises a hydroxyl group-containing monomer, an amide group-containing monomer, a glycidyl group-containing monomer, an oxyalkylene group-containing monomer, and other monomers having two or more ethylenically unsaturated bonds as other functional group-containing monomers. The resin dispersion for water-based inkjet inks of Claim 1 which comprises at least 1 type chosen from more.   The resin dispersion for water-based inkjet inks of Claim 2 which comprises 0.1-10 mass% of said other functional group containing monomer in the said mixture.   Furthermore, the resin dispersion for water-based inkjet inks in any one of Claims 1-3 which comprise a water-based wax dispersion.   The resin dispersion for aqueous inkjet inks according to claim 4, wherein the aqueous wax dispersion is an aqueous polyolefin wax dispersion.   The resin dispersion for water-based inkjet inks of Claim 5 whose melting point of the polyolefin wax contained in the said water-based polyolefin wax dispersion is 100-150 degreeC.   An aqueous inkjet ink comprising the resin dispersion for an aqueous inkjet ink according to any one of claims 1 to 6 and a colorant.