JPH04363369A - Capsule ink composition - Google Patents

Abstract

PURPOSE:To obtain a UV- curing type composition containing a microcapsule, a specific ethylenic unsaturated compound and a photopolymerization initiator as basic components and capable of providing excellent color developing property when used for offset printing. CONSTITUTION:The objective composition obtained by blending (A) microcapsule obtained by subjecting an electron-donating color Producing agent such as diphenylmethane based dye, thiazine based dye or infrared ray developing dye to encapsulization in a state dissolved in oil such as paraffin or triarylmethane with (B) a compound [e.g. 2-phenoxyethyl (meth)acrylate]expressed by the formula [W is H or methyl, X and Y are H or either one of X and Y is H and the other is methyl; Z is (substituted)aryl; (n) is >=1] of 15-85wt.% (as solid content) based on total capsule ink composition and (C) photopolymerization initiator such as benzoquinone or fluorenone of 1-20 pts.wt. based on 100 pts.wt. component B and sensitizer, resin, etc., as other components.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to capsule ink compositions.

0002

[Prior Art] Electron-donating coloring agents such as crystal violet lactone and benzoylleucomethylene blue;
Pressure-sensitive copying paper that utilizes the principle of color development by reaction with an electron-accepting color developer such as activated clay, phenol resin, or polyvalent metal salt of a salicylic acid derivative is well known.

[0003] In general, such pressure-sensitive copying paper is produced using a phase separation method,
Top paper with color developer-containing microcapsules prepared by interfacial polymerization method, in-situ method, etc. applied to the back side of the support, lower paper with color developer applied to the surface of the support, and the above microcapsules and developer. Inner paper sheets coated with colorants on different sides of a support are put into practical use in appropriate combinations. In addition, there are also so-called single-piece pressure-sensitive copying papers in which the above-mentioned microcapsules and color developer are coated as a laminated or mixed layer on the same side of a support, and furthermore, a capsule layer is provided on the back side of the single-piece pressure-sensitive copying paper. There are several types of paper, and these are put into practical use either alone or in appropriate combinations with the above-mentioned top paper, middle paper, or bottom paper.

[0004] Usually, the capsule layer of such pressure-sensitive copying paper is
It is formed by applying an aqueous capsule coating liquid to a support using a large coating machine (hereinafter referred to as the coating method), but special manufacturing methods include converting the capsules into ink, flexographic printing, gravure printing, etc. A method of coating a support with a printing machine such as printing, screen printing, letterpress printing, offset printing, etc.
(hereinafter referred to as printing method). Printing methods can produce small lots with little loss, and are more suitable than coating methods for producing a wide variety of products in small quantities. suitable for production.

[0005] Furthermore, since the printing method allows capsules to be partially printed only on the necessary parts of the support, it is more economical than the coating method in which expensive capsules are applied to the entire surface of the support.
For example, upper paper or inner paper is coated entirely by printing capsule inks of different color tones on high-quality paper or on the back side of the lower paper, or by a coating method as described in JP-A-1-301360. By partially printing capsule ink with a different color tone from that of the capsule on the coated surface of the capsule, it is possible to obtain pressure-sensitive copying paper (upper paper or inner paper) having multiple color tone areas, etc. Certain varieties can be produced.

However, although the printing method is a production method that has many advantages as described above, each of the printing methods including flexo printing, gravure printing, screen printing, letterpress printing, and offset printing has one of the following drawbacks. There is a strong demand for improvement. ■The amount of ink applied is small, which results in poor color development. ■Because the capsule content in the ink is low,
Due to the strong influence of ingredients other than the capsule, the oil release from the capsule becomes poor, resulting in poor color development.

[0007] During printing, the capsules are easily destroyed and colored stains are likely to occur. ■Since solvents are used, there are environmental and safety problems. Among these, in the case of letterpress printing or offset printing, there are many problems such as (1), (2), and (3) mentioned above, so the reality is that a product of practical level has not yet been obtained.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks that have arisen in the production of pressure-sensitive copying paper, particularly in the printing process using conventional capsule inks. As a result of repeated studies, the present inventors have discovered that by using a specific capsule ink composition for printing, it is possible to obtain pressure-sensitive copying paper of high quality, which has not been achieved until now, without any environmental or safety problems. This is what we discovered.

[0009]

[Means for Solving the Problems] The present invention provides an ultraviolet curable capsule ink composition containing microcapsules, an ethylenically unsaturated compound, and a photopolymerization initiator as basic components.
This is a capsule ink composition characterized by containing a compound represented by the following formula [Formula 1] as the ethylenically unsaturated compound.

0010

[Chemical formula 1]

[In the formula, W is a hydrogen atom or a methyl group:
, Y are all hydrogen atoms, or one is a hydrogen atom and the other is a methyl group; Z is an unsubstituted or substituted aryl group:
n = integer greater than or equal to 1]

0012

[Action] The capsule ink composition of the present invention can be used in printing methods such as flexographic printing, gravure printing, screen printing, letterpress printing, and offset printing. Among them, when used for letterpress printing or offset printing, The improvement effect is noticeable in terms of quality such as color development.

The present invention will be explained in detail below using a capsule ink composition for pressure-sensitive copying paper, but the present invention is not limited thereto. First, as the electron-donating coloring agent to be encapsulated in the microcapsules, there may be used, for example, 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(p-dimethylaminophthalide), which is known in the art. -dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, 3,3-bis(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3 -triallylmethane dyes such as -bis(9-ethylcarbazol-3-yl)-6-dimethylaminophthalide, 4,4-bis-dimethylaminobenzhydrylbenzyl ether, N-halophenylleucoauramine, N -Diphenylmethane dyes such as 2,4,5-trichlorophenylleucoauramine, benzoylleucomethylene blue,

Thiazine dyes such as P-nitrobenzoylleucomethylene blue, 3-methyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-
Spiro dyes such as propyl-spiro-dibenzopyran,
Rhodamine-B-anilinolactam, rhodamine (o-
Lactam dyes such as chloroanilino)lactam, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-(N
-ethyl-p-toluidino)-7-methylfluorane,
3-diethylamino-7-N-methylaminofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-(N-ethyl-p-toluidino)-6-methyl-7-phenylaminofluorane, 3- Diethylamino-6-methyl-7-phenylaminofluorane, 3-(
N-cyclohexyl-N-methylamino)-6-methyl-7-phenylaminofluorane, 3-piperidino-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-xylidinofluorane, etc. Red dyes such as fluoran dyes, 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethylene-2-yl]-4,5,6,7-tetrachlorophthalide, etc. Examples include external coloring dyes, which are used alone or in combination.

[0015] The electron-donating coloring agent as described above is usually encapsulated in a state dissolved in oil, and examples of such oil include the following substances known in the art. Vegetable oils such as cottonseed oil; Mineral oils such as kerosene, paraffin, naphthenic oil, and chlorinated paraffin; Aromatic hydrocarbons such as alkylated biphenyls, alkylated terphenyls, alkylated naphthalenes, diarylethanes, triarylmethanes, and diphenylalkanes. Class: dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate,
Esters such as dioctyl phthalate, diethyl adipate, propyl adipate, di-n-butyl adipate, dioctyl adipate, etc., and mixtures thereof.

[0016] The electron-donating coloring agent is usually oil 100
Range of 2 to 80 parts by weight, preferably 5 to 80 parts by weight
It is added in an amount of 50 parts by weight. As the encapsulation method, known coacervation method, interfacial polymerization method, in-s
The itu method etc. can be selected and used as appropriate, but among them, the in-
Capsules made of a melamine-formalin resin film obtained by the in-situ method are particularly preferred because they have excellent solvent resistance and are easy to powder. The average particle diameter of the capsules varies depending on the membrane material or membrane thickness used and cannot be unconditionally determined, but it is usually 1 to 10 μm. Further, the capsule may contain antioxidants, ultraviolet absorbers, fragrances, etc., if necessary.

The capsules obtained by the above method are:
Usually an aqueous dispersion, it can be dried in a semi-dry state after filtration or by air drying, surface drying, fluidized fluid drying, flash drying, spray drying, vacuum drying, freeze drying, infrared drying, high frequency drying, ultrasonic drying. After being subjected to treatments such as drying, pulverization and drying, it is dispersed in the following non-aqueous ink medium in a dry state, and various auxiliary agents are added as necessary to form a capsule ink. In addition, as described in JP-A-53-135718, after mixing the aqueous capsule dispersion and the non-aqueous medium,
Capsules can also be dispersed in a non-aqueous ink medium by removing water under reduced pressure or by filtering the capsule dispersion and then washing and replacing the water with a non-aqueous medium that is miscible with water.

Examples of the compound represented by the formula [Formula 1] used in the present invention include 2-phenoxyethyl (meth)
Acrylate, 2-(nonylphenoxy)ethyl acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)
Acrylate, Bromphenoxydiethylene glycol (meth)acrylate, Butylphenoxydiethylene glycol (meth)acrylate, Butylphenoxydipropylene glycol (meth)acrylate, Hexylphenoxydiethylene glycol (meth)acrylate,
hexylphenoxydipropylene glycol (meth)acrylate, octylphenoxydiethylene glycol (meth)acrylate, octylphenoxydipropylene glycol (meth)acrylate, nonylphenoxydiethylene glycol (meth)acrylate, nonylphenoxydipropylene glycol (meth)acrylate,

Laurylphenoxydiethylene glycol (meth)acrylate, laurylphenoxydipropylene glycol (meth)acrylate, naphthoxydiethylene glycol (meth)acrylate, naphthoxydipropylene glycol (meth)acrylate, bitylnaphthoxydiethylene glycol (meth)acrylate, bromine naphthoxydiethylene glycol (meth)acrylate, hydroxyphenoxypolyethylene glycol (
meth)acrylate, chlorphenoxypolypropylene glycol (meth)acrylate, butylphenoxypolyethylene glycol (meth)acrylate, butylphenoxypolypropylene glycol (meth)acrylate, hexylphenoxypolyethylene glycol (meth)acrylate, hexylphenoxypolypropylene glycol (meth)acrylate,

Octylphenoxypolyethylene glycol (meth)acrylate, octylphenoxypolypropylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolypropylene glycol (meth)acrylate, laurylphenoxypolyethylene glycol (meth)acrylate, laurylphenoxy Examples include polypropylene glycol (meth)acrylate, naphthoxypolypropylene glycol (meth)acrylate, and among them, those in which n=1 to 10 are preferred.

As the ethylenically unsaturated compound used in the present invention, compounds known in the art and commonly used in the art other than the formula [Formula 1] can be used in combination, such as methyl methacrylate, butyl methacrylate, 2-ethoxy Ethyl acrylate, cyclohexyl methacrylate,
Benzyl methacrylate, trifluoroethyl methacrylate, 3-sulfopropyl methacrylate potassium salt, N-(3-sulfopropyl)-N-methacryloylamidopropyl-N,N-dimethylammonium betaine, glycidyl methacrylate, allyl methacrylate,
Dimethylaminoethyl methacrylate, 3-chloro-2
- hydroxypropyl methacrylate,

Ethoxydiethylene glycol acrylate, benzyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, 1-methoxycyclododecadienyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 2
-hydroxy-3-phenoxypropyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2,6-dibromo-4-t-butylphenyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate , propylene glycol dimethacrylate,

Polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, 1,2
-butanediol diacrylate, 1,2-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate,
1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, glycerol dimethacrylate, glycerol methacrylate acrylate, Trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, hydroxypivalic acid neopentyl glycol ester diacrylate, 2,2-bis[4-(acryloyloxydiethoxy)phenyl]propane , caprolactone adduct diacrylate of hydroxypivalic acid neopentyl glycol ester, diacrylate of acetal compound of hydroxypivalaldehyde and trimethylolpropane, diallyloxy diacryloyloxycyclohexane, trimethylolpropane propylene oxide adduct triacrylate, Examples include esters of lower fatty acids and acrylic acid of pentaerythritol, caprolactone adduct acrylate of dipentaerythritol, dioctyl 2-acryloyloxyethyl phosphate, diphenyl 2-acryloyloxyethyl phosphate, among others, polyfunctional monomers or Those used in combination with oligomers are preferred because they have a good balance between color development and stain resistance.

The amount of the ethylenically unsaturated compound represented by formula [Chemical formula 1] in the capsule ink is 15 to 85% by weight of the total capsule ink composition (as solid content).
A range of is preferred. Incidentally, less than 15% by weight or 85% by weight
If it exceeds the weight percentage, it is difficult to obtain the desired and satisfactory effects of the present invention. In addition, the viscosity of the ethylenically unsaturated compound used is 1 to 5000 cps (at 25°C).
Those having a viscosity exceeding 5,000 cps tend to have a lower ink transferability and poor color development.

[0025] The photopolymerization initiator used in the present invention includes:
For example, aromatic ketones and quinones such as benzoquinone, phenanthrenequinone, naphthoquinone, diisopropylphenanthrenequinone, benzoisobutyl ether, benzoin, furoinbutyl ether, Michler's ketone, Michler's thioketone, fluorenone, trinitrofluorenone, β-benzoylaminonaphthalene, etc. compounds, ether compounds, and nitro compounds.

The photopolymerization initiator is usually added in an amount of 1 to 20 parts by weight per 100 parts by weight of the ethylenically unsaturated compound. A sensitizer may be added to further promote polymerization, and examples of such sensitizers include triethanolamine, N-methyldiethanolamine, and N-methyldiethanolamine.
, N-dimethylethanolamine, N-methylmorpholine and the like.

As the ink medium used in the capsule ink of the present invention, in addition to the above-mentioned compounds, a high boiling point medium, resin, waxes, and oils may be used in combination as required.

Incidentally, examples of high boiling point media include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 2,3-butylene glycol, methyl cellosolve, cellosolve, butyl cellosolve, carbitol, butyl carbitol. Thor et al.

Examples of the resin include gum rosin, wood rosin, shellac, ester gum, pentaerythritol ester of rosin, pentaerythritol ester of polymerized rosin, maleic acid resin, pentaerythritol ester of maleated rosin, dimerized rosin, and rosin-modified phenol resin. , butanol-modified urea resin, butanol-modified melamine resin, terpene resin, terpene phenol resin, soybean oil-modified alkyd resin, polyamide resin, polyvinyl acetate, acrylic resin, vinyl chloride, vinyl chloride,
Vinyl acetate copolymer, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, modified polyvinyl alcohol, polyvinyl butyral, Examples include polyvinylpyrrolidone, ethylcellulose, nitrocellulose, hydroxypropylcellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like.

Examples of waxes include beeswax, spermaceti, lanolin, candelilla wax, carnauba wax, wood wax, rice wax, montan wax,
Ozokerite, paraffin wax, microcrystalline wax, montan wax derivative, paraffin wax derivative, microcrystalline wax derivative, castor wax, opal wax, low molecular weight polyethylene, distearyl ketone, caprylic acid amide,
Examples include stearamide, ethylene bisstearamide, stearic acid, behenic acid, stearyl alcohol, distearyl phosphate, and the like.

Examples of oils include vegetable oils such as linseed oil, safflower oil, soybean oil, and castor oil; processed oils such as dehydrated castor oil, polymerized oil, maleated oil, vinyl oil, and urethane oil; machine oil, spindle oil, etc. Mineral oils such as

In addition to the ink medium and microcapsules described above, the capsule ink of the present invention may further contain stilt materials such as cellulose powder, starch particles, and synthetic resin particles, titanium oxide, zinc oxide, calcium carbonate, and aluminum hydroxide, if necessary. , a white pigment such as silica, a desensitizing component for color development such as a desensitizer, an ultraviolet absorber, an antioxidant, a fluorescent whitening agent, a plasticizer, a colored dye, etc. may be added as appropriate.

The content of capsules in the capsule ink is usually adjusted within the range of 5 to 80 parts by weight per 100 parts by weight of the ink. In addition, the content of the ink medium is usually ink 1
The amount is adjusted to be in the range of 30 to 95 parts by weight relative to 00 parts by weight. Further, the proportion of the ethylenically unsaturated compound in the ink medium is in the range of 30 to 99% by weight. Ink is usually
The ink medium is prepared by adding microcapsules and other auxiliary agents and thoroughly mixing them using a propeller disperser, an ultrasonic disperser, a ball mill, or a three-roll mill.

The capsule ink thus prepared is printed on various supports by various printing methods such as flexo, letterpress, offset, gravure, and screen, usually in a dry weight of 1 to 1.
It is coated in an amount of 0 g/m2, preferably in the range of 2 to 6 g/m2. Supports used for printing include, for example, wood-free paper, synthetic paper, film, art paper, coated paper, cast paper, lightly coated paper, and pressure-sensitive copying paper (top paper, middle paper, bottom paper, Cercon paper). etc.

The substances contained in the capsule of the capsule ink of the present invention are not limited to materials for pressure-sensitive copying paper, and include, for example, fragrances, liquid crystals, temperature indicating materials, rust preventives, insect repellents, rodenticides, and adhesives. agent, adhesive, etc.

[0036]

EXAMPLES In order to make the effects of the present invention even clearer, Examples and Comparative Examples will be described below, but the present invention is not limited to these Examples. Note that parts and % in the examples represent parts by weight and % by weight, respectively, unless otherwise specified.

Example 1 (Preparation of capsule ink) 3,3-bis(2-methyl-
An internal phase oil was obtained by heating and dissolving 25 parts of 1-octyl-3-indolyl) phthalide in 75 parts of benzyltoluene. Subsequently, 3 of ethylene-maleic anhydride copolymer (trade name EMA-31, manufactured by Monsanto) whose pH was adjusted to 6.0 was added.
After emulsifying the internal phase oil in 200 parts of % aqueous solution, this system was
The temperature was raised to 5°C.

Separately, 37% formaldehyde aqueous solution 45
15 parts of melamine was added to the mixture and reacted at 60° C. for 15 minutes to prepare an aqueous prepolymer solution. This prepolymer aqueous solution was added dropwise to the emulsion, and while stirring, 0.1
After adjusting the pH to 5.3 by dropping N hydrochloric acid, the system was heated to 80°C.
After stirring for 1 hour, 0.2N hydrochloric acid was added dropwise to lower the pH to 3.5. After stirring for a further 3 hours, the capsules with an average particle diameter of 3.8 μm were dispersed. I got the liquid.

Next, this dispersion was filter-pressed and then air-dried to form powder capsules, and 100 parts of the capsules were mixed with 400 parts of an ethylenically unsaturated compound [2-(
nonylphenoxy)ethyl acrylate:pentaerythritol triacrylate = 7:3] and a photopolymerization initiator (
Capsule ink was prepared by adding and mixing 10 parts of benzoin methyl ether and 20 parts of titanium oxide.

(Preparation of upper paper) Letterpress printing of the above capsule ink on 40 g/m2 base paper (ink amount 5.0 g/m2)
2) and was cured using a 6 kW ultraviolet irradiation device to obtain a top paper.

(Preparation of oil capsules) Ethylene-maleic anhydride copolymer (trade name: E) whose pH was adjusted to 6.0.
After emulsifying 100 parts of alkyldiphenylethane as an internal phase oil into 200 parts of a 3% aqueous solution of MA-31 (manufactured by Monsanto), the system was heated to 55°C. Separately, add 15 parts of melamine to 45 parts of 37% formaldehyde aqueous solution,
A prepolymer aqueous solution was prepared by reacting at 0°C for 15 minutes.

This prepolymer aqueous solution was added dropwise to the emulsion, and 0.1N hydrochloric acid was added dropwise while stirring.
After setting H to 5.3, the system was heated to 80°C and stirred for 1 hour, then 0.2N hydrochloric acid was added dropwise to lower the pH to 3.5, and after stirring for another 3 hours, it was cooled. A dispersion of capsules having an average particle diameter of 5.0 μm was obtained.

(Preparation of bottom sheet) Light calcium carbonate 60
10 parts of zinc oxide, 10 parts of a blend of zinc 3,5-di(α-methylbenzyl)salicylate and α-methylstyrene-styrene copolymer (melt ratio 80/20), 10 parts of the above oil capsules 10 parts of pulp powder was dispersed in 300 parts of 0.2% polyvinyl alcohol aqueous solution, and 10 parts (solid content) of gelatinized starch and 15 parts (solid content) of carboxy-modified styrene-butadiene latex were added, and then diluted. 40g/m2 of 30% by weight color developer coating solution prepared by
The base paper was coated with an air knife coater so that the dry weight was 7 g/m2 to obtain a base paper.

(Evaluation) When the thus obtained upper paper and lower paper were overlapped and printed using a typewriter, an extremely clear colored image was obtained on the surface of the lower paper corresponding to the printed portion of the capsule.

Example 2 (Preparation of top paper) Offset printing of the above capsule ink on 40 g/m2 base paper (ink amount 3.0 g/m2)
Then, it was cured using a 6 kW ultraviolet irradiation device to obtain a top paper.

(Evaluation) When the upper paper thus obtained and the lower paper obtained in the same manner as in Example 1 were overlapped and printed using a typewriter, extremely clear marks were printed on the lower paper surface corresponding to the printed portions of the capsule. A colored image was obtained.

Example 3 An ink was prepared in the same manner as in Example 1, except that 400 parts of (nonylphenoxydiethylene glycol acrylate: 1,6-hexanediol diacrylate = 5:5) was used as the ethylenically unsaturated compound. The upper paper was prepared and evaluated in the same manner as in Example 1. The color image obtained was extremely clear.

Example 4 The same procedure as in Example 1 was carried out except that 400 parts of [2-(nonylphenoxy)ethyl acrylate:1,6-hexanediol diacrylate=6:4] was used as the ethylenically unsaturated compound. An ink was prepared, and a top paper was prepared and evaluated in the same manner as in Example 1. The color image obtained was quite clear.

Example 5 An ink was prepared in the same manner as in Example 1, except that 400 parts of (butyl phenoxy polypropylene glycol acrylate: 1,6-hexanediol diacrylate = 5:5) was used as the ethylenically unsaturated compound. Then, the upper paper was prepared and evaluated in the same manner as in Example 1. The color image obtained was extremely clear.

Example 6 Same as Example 1 except that 400 parts of (nonylphenoxydipropylene glycol acrylate: nonylphenoxypropylene glycol acrylate: polypropylene glycol dimethacrylate = 4:3:3) was used as the ethylenically unsaturated compound. An ink was prepared, and a top paper was prepared and evaluated in the same manner as in Example 1. The color image obtained was extremely clear.

Comparative Example 1 An ink was prepared in the same manner as in Example 1, except that 400 parts of pentaerythritol triacrylate was used as the ethylenically unsaturated compound, and a top paper was prepared and evaluated in the same manner as in Example 1. I did it. The color image obtained was quite poor.

[0052]

[Effects of the Invention] Pressure-sensitive copying paper printed with the capsule ink of the present invention exhibited extremely excellent color development.

Claims (1)

[Claims] Claim 1: In an ultraviolet curable capsule ink composition containing microcapsules, an ethylenically unsaturated compound, and a photopolymerization initiator as basic components, a compound represented by the following formula [Chemical formula 1] is used as the ethylenically unsaturated compound. A capsule ink composition characterized by comprising: [Formula, W is a hydrogen atom or a methyl group; X and Y are both hydrogen atoms, or one of them is a hydrogen atom and the other is a methyl group; Z is an unsubstituted or substituted aryl group: n=1 Integer greater than or equal to