JPH0547093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to capsules, and more particularly to capsules for recording materials having a specific combination of core material and wall material.

(Prior Art) The present inventors have proposed a recording system that obtains color images through a few simple operations using a combination of a polymerizable compound, a colorant precursor, and a photopolymerization initiator.

For example, in a recording system that uses a capsule containing a polymerizable compound, a colorant precursor, and a photopolymerization initiator, the capsule layer is imagewise exposed to light, and then a component that reacts with the colorant precursor to provide the colorant is coated. When pressure is applied on the layer, the capsule in the polymerized area hardens and becomes indestructible. On the other hand, the capsules in the unpolymerized area, that is, the unexposed area, are destroyed by pressure to release the colorant precursor and form a colorant.

However, this recording system also had some points that needed improvement.

For example, it has been difficult to obtain high image density while maintaining the S/N ratio.

In order to increase the image density, it is necessary to increase the colorant precursor concentration, but increasing the colorant precursor concentration in the capsule relatively decreases the polymerizable compound concentration, making it difficult to obtain sufficiently hardened capsules. There was a problem.

Another problem is that the colorant precursor in the exposed area bleeds during pressurization, handling, etc., resulting in fogging.

On the other hand, the present inventors have developed functional colorant precursors. For example, colorant precursors with a huge planar and conjugated structure such as a fluoran ring also undergo a polymerization reaction relatively easily, and the colorant precursor itself becomes insolubilized. It was found that physical changes such as thickening occur.

(Object of the invention) The object of the invention is to provide high color density,
Capsules useful for recording systems that have clear differences in unexposed areas and, if necessary, can be exposed to light, pressurized, and then re-exposed to make the colorant precursor released from the capsule insolubilized and chemical resistant. It relates to a capsule consisting of a wall agent.

(Structure of the Invention) The object of the present invention was achieved by developing a polymeric resin-walled capsule containing a colorant precursor having a polymerizable group, a photopolymerization initiator, and an organic liquid as core materials.

In the present invention, a colorant precursor having a polymerizable group can be synthesized by reacting a reactive compound having a vinyl group or an acrylic group with a colorant precursor having at least one active hydrogen.

For example, 1) Vinylbenzoic acid chloride 2)
Vinyl phenyl isocyanate 3) Vinylbenzoic acid glycidyl ester 4) Divinylbenzene monoepoxide 5) Vinylphenol glycidyl ether 6) Vinylbenzyl chloride
7) Formylstyrene 8) Styrenesulfonyl chloride 9) Bromoethylbenzenesulfonyl chloride 10) Vinylphenylacetic acid chloride
11) Vinyl phenoxyacetyl chloride 12) Vinyl acetophenone 13) Vinyl-α-bromoacetophenone 14) Vinyl phenyl vinyl sulfone 15) Bromostyrene 16) Bromoethylbenzoic acid chloride 17) Acrylic acid chloride 18)
Methacrylic acid chloride 19) Acryloxyethyl tosylate 20) β-Acryloxypropionic acid chloride 21) Glycidyl methacrylate
22) Ethyl acrylate 23) Glycidyl acrylate 24) β-acrylamidopropanesulfonyl chloride 25) Allyl bromide are examples of reactive compounds having a vinyl group or an acrylic group. This is advantageous from the viewpoint of coloring property during reaction with and handling.

As colorant precursors, compounds having partial skeletons such as lactones, lactams, sultones, spiropyrans, esters, and amides, which become ring-opening or cleavage upon contact with a color developer, become colored substances. include. Among these, those containing one or more active hydrogens are particularly preferred.

Examples of such compounds include 1) 2-amino-6-diethylaminofluorane 2) 2-amino-3-methyl-6-dibutylaminofluorane 3) 2-amino-3-pentadecyl-6-N
-ethyl, N-isoamylaminofluorane
4) 2-Amino-3-methyl-6-dibutylaminofluorane 5) 2-ethylamino-3-methyl-6-dibutylaminofluorane 6) 2-β
-Hydroxyethylamino-6-diethylaminofluorane 7) 2-anilino-3-methyl-6
-ethylaminofluorane 8) 2-anilino-
3-Methyl-6-N-methyl-β-aminoethylaminofluorane 9) 2-p-aminoanilino-3-methyl-6-diethylaminofluorane
10) 2-Hydroxy-4-diethylaminophenyl-2'-hydroxy-4'-methyl-5'-anilinophenyl phthalide 11) Michler Hydrol
12) 4-Diethylaminophenyl-4'-ethylaminophenyl phthalide 13) 3(2'-acetoxy-4'-ethylaminophenyl)-3-(1''-n-octyl-2''-methylindole -3″-yl)phthalide 14) N-ethylaminobenzoylleucomethylene blue, etc.

Among these, preferred are oil-soluble compounds with a melting point of 60°C or higher.

For example, examples of preferred compounds according to the present invention are as follows.

1) 2-p-vinylbenzoylamino-6-diethylaminofluorane 2) 2-p-(4'-vinylbenzoylamino)anilino-3-methyl-
6-dibutylaminofluorane 3) 2-p-
(4'-vinylbenzylamino)anilino-3-chloro-6-N-ethyl-N-isoamylaminofluorane 4) 2-vinylbenzylideneamino-
6-diethylaminofluorane 5) 2-β-
(p-vinylbenzoylamino)ethylamino-
3-chloro-6-diethylaminofluorane,
6) 2-β-(p-vinylbenzoylaminoethylamino)ethylamino-6-diethylaminofluorane, 7) 2-p-vinylbenzenesulfonylamino-3-isoamyl-6-diethylaminofluorane, 8) 2-anilino -3-methyl-6
-N-ethyl, N-β-p-vinylbenzoylaminoethylamino-fluoran, 9) (p-vinylbenzoylamino)benzoylleucomethylene blue, 10) 4-diethylaminophenyl-4'-
N-ethyl-N-vinylbenzylaminophenyl phthalide, 11) 2-p-vinylbenzoyloxy-4-diethylaminophenyl-2'-p-vinylbenzoyloxy-4'-methyl-5'-anilinophenyl Phthalide, 12) 2-p-vinylphenyl ureido 6-diethylaminofluorane, 13) 2-
p-vinylanilino-3-methyl-6-diethylaminofluorane, 14) 2-anilino-4-γ-
p-vinylbenzoylaminobutyl-6-diethylaminofluorane, 15) 2-β-hydroxy-
γ-p-vinylphenoxypropylamino-6-
Diethylaminofluorane, 16) 2-methacrylamino-3-ethyl-6-dibutylaminofluorane, 17) 2-p-methacrylaminoanilino-
6-diethylaminofluorane, 18) 2-p-acrylaminoanilino-6-dibutylaminofluorane, 19) 2-β-acrylaminoethylamino-6-dibutylaminofluorane, 20) 2-β
-acrylaminopropylamino-3-chloro-
6-diethylaminofluorane, 21) 2-anilino-3-β-acrylaminoethyl-6-diethylaminofluorane, 22) 2-p-chloroanilino-3-β-methacrylaminopropyl-6-dibutylaminofluorane, 23 )2-anilino-3
-Methyl-6-N-p-acrylaminoanilino-N-ethylaminofluorane, 24) 2-dibenzylamino-6-N-acrylamino-N-ethylfluorane, 25) 2-hexylamino-6 -N
-methacrylamino-N-methylfluorane.
26) 2-acrylamino-6-diethylaminofluorane, 27) 2-acrylamino-6-dibutylaminofluorane, 28) 2-acrylamino-
6-N-cyclohexyl-N-methylaminofluorane, 29) 2-acrylamino-3-chloro-
Examples include 6-diethylaminofluoran, 30) 2-acrylamino-3-methyl-6-diethylaminofluoran, and the like.

Further, colorant precursors having these polymerizable groups and other vinyl compounds can also be used in combination.

For example, acryloyl group, metallolyloyl group,
Allyl group, unsaturated polyester, vinyloxy,
Examples include compounds having an acrylamide group. The most typical examples include reaction products of polyols, polyamines, amino alcohols, etc. and unsaturated carboxylic acids, and reaction products of acrylates or methacrylates having hydroxyl groups and polyisocyanates.

Typical compounds include polyethylene glycol diacrylate, propylene glycol dimethacrylate, pentaerythritol triacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, hexanediol diacrylate, and 1,2-butanediol diacrylate. , tetrakis β-acryloxyethyl ethylene diamine, reaction product of epoxy resin and acrylic acid, reaction product of methacrylic acid, pentaerythritol and acrylic acid, condensation product of maleic acid, diethylene glycol and acrylic acid, methyl methacrylate, butyl methacrylate, styrene and so on. Regarding these monomers, see JP-A-49-52889, JP-A No. 48-68641, JP-A No. 48-32586,
You can also choose from those disclosed in Japanese Patent Publication No. 49-7115. It is preferable to use these in an amount of about 0.1 to 20 times per 1 of the colorant precursor having a polymerizable group.

In particular, photopolymerizable or photocrosslinkable vinyl monomers, such as patent application No. 118984/1984 (West German patent number
2164625), JP-A No. 49-36794, JP-A No. 49-38987, JP-A No.
49-60390, 49-103975, 49-107226, acrylate or methacrylate with a β-aryl substituted acrylate group, styrene with an azide group, acrylate or methacrylate with a β-aryl acrylate group, vinyl cinnamic acid Alternatively, derivatives thereof, vinyl ethers, acrylates or methacrylates, vinyl chalcone, ethyl methacryloxycinnamate, etc. having a δ-aryl substituted pentadienoic acid ester group can also be used in combination.

These are released after the capsules in the unexposed area are ruptured under pressure, but when exposed there, they have the advantage of causing a photocuring reaction and improving solvent resistance.

These are colorant precursors 1 with polymerizable groups.
It is used at a rate of 0.1 to 50 times.

A plurality of these may be used in combination depending on the purpose.

The photopolymerization initiator of the present invention means that by irradiation with light,
It includes single or combinations of organic or inorganic compounds that have the ability to initiate polymerization of vinyl compounds.

These materials are already well-documented in detail.
For example, Kosar “Light Sensitive Systems
“John Wiley & Sons, Warashina et al. “Photosensitive resin”
It has been disclosed by Nikkan Kogyo Shimbun, Tsunoda et al.'s "Photosensitive Resin" Society of Printing, etc.

Specific examples of photopolymerization initiators include aromatic ketones, quinone compounds, ether compounds, nitro compounds, and halogen compounds.

Specifically, benzoquinone, phenanthrenequinone, naphthoquinone, diisopropylphenanthrenequinone, benzoin butyl ether, benzoin, furoinbutyl ether, Michler's ketone, Michler's thioketone, tetraphenyllovhine dimer, fluorenone, trinitrofluorenone, β- Contains benzoylaminonaphthalene.

These are 0.1% to 8% of the polymerizable compound
Added to a certain extent.

Further, common colorant precursors such as triarylmethane compounds, diphenylmethane compounds, xanthene compounds, thiazine compounds, spiropyran compounds, etc. are used. Some examples of these include triarylmethane compounds such as 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3,
3-bis(p-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-
(1,3-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-
(2-methylindol-3-yl) phthalide, etc. Diphenylmethane compounds include:
There are 4,4'-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leucoauramine, N-2,4,5-trichlorophenylleucoauramine, and xanthene compounds include rhodamine-B. -anilinolactam, rhodamine (p-nitroanilino)lactam, rhodamine B (p-chloroanilino)lactam, 2-
Dibenzylamino-6-diethylaminofluorane, 2-anilino-6-diethylaminofluorane, 2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6
-N-cyclohexyl-N-methylaminofluorane, 2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluorane, 2-o-
Chloroanilino-6-diethylaminofluorane, 2-(3,4-dichloroanilino)-6-diethylaminofluorane, 2-octylamino-6
-diethylaminofluorane, 2-anilino-3
-Methyl-6-diphenylaminofluorane, 2
-anilino-3-methyl-5-chloro-6-diethylaminofluorane, 2-anilino-3-methyl-6-diethylamino-7-methylfluorane, 2-p-chloroanilino-3-phenyl-6
-diethylaminofluorane, 2-phenyl-6
-diethylaminofluorane, etc. Thiazine compounds include benzoyl leucomethylene blue, p-nitrobenzyl leucomethylene blue, etc., and spiro compounds include 3-methyl-
Spiro-dinaphthopyran, 3-ethyl-spiro-
Dinaphthopyran, 3,3'-dichloro-spiro-dinaphthopyran, 3-benzylspiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxy-benzo)-spiropyran, 3-propyl-spiro-
Examples include benzylpyran. By using these together with polymerizable colorant precursors, hue adjustment,
It has advantages such as improved resistance.

Particularly preferred is a case where about 0.1 to 50 parts are used per 1 part of the polymerizable colorant precursor.

In the present invention, the organic liquid refers to a colorant precursor,
A capsule core material consisting of a photopolymerization initiator is held in a low-viscosity dispersion, and the photopolymerization initiator or other liquid vinyl monomer can be substituted.

In addition, it is also possible to use evaporative solvents used in pressure-sensitive paper, etc. (synthetic oils such as alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated diarylethane, chlorinated paraffin, etc.), or fatty acids/aromatics. Group ethers, aliphatic ketones, organic acid esters, etc. can also be used in combination.

The colorant precursor having a polymerizable group is used in the capsule in an amount of about 0.1 to 15 wt%.

The synthetic resin wall in the present invention refers to polyurea, polyurethane amino resin, or modified products thereof.
Capsules that use coacervation gelatin as a wall or hydrophilic polymers such as polyvinylpyrrolidone or polyvinyl alcohol are difficult to obtain with sufficient preservability for recording purposes. Particularly, the effects are great when using a method based on polymer precipitation and an encapsulation method based on polymerization of a reactant from inside the oil droplet. That is, desirable capsules with uniform particle size, dense walls, and excellent preservability can be obtained within a short period of time.

For specific examples of this method and compounds, please refer to the U.S. patent
Details in the specifications of 3726804 and 3796669. However, the polyisocyanate used and the other polyol,
For polyamines, U.S. Patent 3135716,
3281383, 3468922, 3773695, 3793268, Special Publication Showa 48
-40347, 49-24159, JP-A-48-80191, 48
-84086, and you can also choose them.

Moreover, a tin salt can also be used in combination to promote the urethanization reaction. The particle size of the capsules is preferably 80 μm or less, particularly 20 μm or less from the viewpoint of ease of handling during storage. Further, from the viewpoint of ease of transfer, it is desirable that the thickness be 2μ or more. That is, it is desirable that there is no substantial change at pressures of 10 Kg/cm ² or less, and that about 50% or more of the capsules are destroyed at about 100 Kg/cm ² . Capsules are prepared by coating a coloring agent precursor having a polymerizable group on a support so that the amount of the coloring agent precursor is about 0.1 g to 2 g.

As the support, plastic film, synthetic paper, aluminum plate, paper, etc. are used.

When coating the support, a binder such as PVA or latex, a protective agent such as starch particles, etc. are used. In addition, various additives, binders, antioxidants, anti-smearing agents, surfactants, coating methods, usage methods, etc. used in recording systems are well known and have been patented in the United States.
2711375, 3625736, British Patent 1232347, JP-A-Sho
No. 50-44012, No. 50-50112, No. 50-127718,
No. 50-30615, U.S. Patent No. 3836383, U.S. Patent No. 3846331
There are disclosures in the issue, etc., and you can use those methods.

(Examples of the Invention) Examples will be given below to further clarify the effects of the present invention.

Color developer coated sheets A and B used in reference examples
was created using the following method.

Color developer coated sheet A Rodan zinc is 50g in basis weight so that it is 1.5g/ ^m2
Painted on high quality paper.

Color developer coated sheet B 65 parts of light calcium carbonate, 35 parts of aluminum hydroxide (Showa Denko H-10), 1.8 parts of styrene-α-methylstyrene decamer and 3,5-di-α-methylbenzyl Kneaded and ground product with 8.2 parts of zinc salicylate,
10 parts of zinc oxide, 0.2 parts of 2-hydroxy-4-butoxybenzophenone, and 1 part of sodium hexametaphosphate were dispersed in 200 ml of water, and then treated with a sand mill to obtain a dispersion having an average particle size of 2.6 μm. Add 9 parts of polyvinyl alcohol to this and carboxy-modified
Add 20 parts of SBR latex (48%) and 110 parts of water and stir well.

This was added to a base paper with a basis weight of 43 g/m ² as a solid content of 5.2
g/m ² and dried at 90°C.

Example 1 Pentaerythritol tetraacrylate 9
parts, 2 parts of ethyl acetate, 2-acrylamino-6-
Diethylaminofluorane 0.5 part, 2-propionylamino-6-dibutylaminofluorane 0.3
1 part, 3 parts of 1-phenyl-1-xylylethane, 0.3 part of benzoinbutyl, tolylene diisocyanate and trimethylolpropane (3:1) adduct
0.7 parts and 0.2 parts of propylene oxide (1:4) adduct of ethylene diamino were added and dissolved.

The solution thus obtained was emulsified and dispersed in a solution of 2.6 parts of polyvinyl alcohol dissolved in 29 parts of water at 20°C.
Set to 8μ. After emulsification, 100 parts of water was added and heated at 50°C to 70°C for 2 hours while stirring to obtain capsules. The average particle size was 8μ.

Example 2 Encapsulation was carried out in the same manner as in Example 1, except that 2-p-vinylbenzoylamino-6-dibutylaminofluorane was used instead of 2-acrylamino-6-diethylaminofluorane. The emulsified droplets were made to be 10μ to obtain capsules with an average particle size of 10μ.

Reference Example 1 5% SBR was added to the capsule liquid obtained in Example 1 to prepare a coating liquid. This was applied onto base paper and a phosphate-treated aluminum plate using a coating rod 38.

This capsule-coated sheet was exposed to light from a distance of 25 cm for 3 minutes using a 400 W high-pressure mercury lamp through the color-dispersed original.

This image-exposed sheet was placed first.
This was layered with developer-coated sheet B and pressed to 50 kg/cm ² for 10 seconds. The capsules in the unexposed areas were destroyed and transferred to a developer-coated sheet.

The transferred area gave a bright red color no matter which support was used.

Reference Example 2 When the capsule-coated sheet obtained in Reference Example 1 was pressed against the developer-coated sheets A and B, a clear and durable red image was obtained in the pressed area.

Claims (1)

[Claims] 1. A polymeric resin-walled capsule for recording materials containing a colorant precursor having a polymerizable group, a photopolymerization initiator, and an organic liquid as core substances.