JPS63188088A - Color proofing sheet - Google Patents

Abstract

PURPOSE:To obtain a maintenance free sheet for a compact printer by perfect dry treatment, by constituting each color separation sheet by a method wherein a coating solution containing a microcapsule, which contains a color former as a core substance, and an emulsified and dispersed coupler is applied to a transparent support and dried to form a thermal color forming layer and a protective film is subsequently laminated to said layer. CONSTITUTION:A coating solution containing a dispersion, wherein a microcapsule having a color former encapsulated therein and at least a coupler are emulsified and dispersed, as a main component and further containing a binder and other additives is prepared and applied to a transparent support such as a synthetic resin film by a bar or blade coating method and dried to provide a thermal layer containing 2.5-25 g/m<2> of a solid. A protective layer mainly aiming preservability and stability is provided on the thermal layer. The thermal layer of the thermal material thus formed has extremely good transparency. By this method, since each color separation image is rapidly obtained by a perfect dry and maintenance free compact thermal printer, overlay type color correction can be performed in an extremely simple manner.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a multicolor color proofing sheet for color proofing, and particularly relates to a completely dry and maintenance-free heat-sensitive coloring overlay type multicolor color proofing sheet. Regarding.

(Conventional technology) Overlay color proofing is a method in which each color is created separately on a transparent base film, and then superimposed on a white sheet of paper and viewed using reflected light.It is much simpler than the subprint method or transfer method. It has the advantage of being able to be used for inspection. However, both products using conventional diazo resin coating layers and products using diazo photographic materials have no choice but to use developer solution or gas for development, which takes up a large amount of floor space.
Management and maintenance of the developer and equipment is essential.

Problems to be Solved by the Invention It is therefore an object of the present invention to provide a maintenance-free color proofing sheet that is completely dry processed using a compact printer.

(Means for Solving the Problems) An object of the present invention is to coat a transparent support with a coating liquid containing microcapsules in which each color separation sheet contains a color former as a core material and a color developer emulsified and dispersed. This was achieved by a color proofing sheet characterized by comprising a heat-sensitive color-forming unit layer which is dried to form a heat-sensitive color-forming layer, and then a protective layer is laminated thereon.

Each color separation sheet is a transparent thermal film that uses a separated negative or a separated positive that has been color-separated and halftone-photographed as an original, is read by the reading section of a thermal printer, and is colored in the predetermined hues of yellow, magenta, cyan, and black. Obtained by thermal recording. Additionally, thermal printers are capable of electrically reversing the shading, making it possible to create negative and positive proofs using one type of proofing sheet for each color separation. There is.

Transparent color-separated images are obtained without complicated liquid development, and proofreading can be performed by superimposing these images on white paper and viewing them with reflected light.

As the basic dye precursor as a coloring agent used in the present invention, a colorless or light-colored one is appropriately selected from known compounds that develop color by donating electrons or accepting protons such as acids. Such compounds have partial skeletons such as lactones, lactams, sultones, spiropyrans, esters, and amides, and these partial skeletons are ring-opened or cleaved upon contact with a color developer. Preferred compounds include , for example, triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds,
Examples include spiropyran compounds.

More specific examples include "Paper and Pulp Technology Times 999-70? (February 1920 issue)" by Masakichi Yahagi, and "Paper and Pulp Technology Times Jpa3-!0 (Showa 0! Month issue) by Takashi Shiga. From those listed in , those that develop cyan, magenta, yellow, and black can be appropriately selected and used.

In the present invention, by encapsulating the above-mentioned coloring agent in microcapsules, it is possible to prevent capri during the production of heat-sensitive materials, and at the same time, to improve the shelf life and archival stability of heat-sensitive materials. can. In this case, by selecting the wall material and manufacturing method of the microcapsule, it is possible to increase the image density during recording. The amount of coloring agent used is 0.0! ~s, Og/m2 is preferred.

Examples of the wall material of the microcapsule include polyurethane, polyurea, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene methacrylate copolymer, styrene-acrylate copolymer, gelatin, polyvinylpyrrolidone, polyvinyl alcohol, etc. . In the present invention, two or more of these polymeric substances can also be used in combination.

In the present invention, among the above-mentioned polymeric substances, polyurethane, polyurea, polyamide, polyester, polycarbonate, etc. are preferable, and polyurethane and polyurea are particularly preferable.

The microcapsules used in the present invention are preferably microencapsulated by emulsifying a core material containing a reactive substance such as a coloring agent, and then forming a wall of a polymer material around the oil droplets. In this case, a polymeric material is formed or an actant is added to the interior of the oil droplet and/or to the exterior of the oil droplet. For details about microcapsules that can be preferably used in the present invention, such as a preferred method for producing microcapsules, see, for example, JP-A-5-2, 2.2.27/! ! ; stated in the issue.

Here, the organic solvent for forming oil droplets can generally be appropriately selected from high boiling point oils, but
In particular, when an organic solvent suitable for dissolving the color developer described below is used, it has excellent solubility for leuco dyes, increases color density and color development speed during thermal printing, and has little fogging. This is preferable because it can be done.

In the present invention, the size of the microcapsule is, for example, JP-A-Sho t<0-2/4t? The volume average particle size measured by the measurement method described in No. 90 is preferably 2μ or less, particularly preferably /μ or less.

Also, if necessary, for example, a patent application from 1986 to 1983, 4t? 0
A photofading inhibitor described in No., No. 6θ-/η]2/, and No. 4T No. 6θ-/2j4t72 can be added as appropriate.

As a color developer that causes a color-forming reaction with the basic colorless dye used in the present invention, any known color developer can be used as appropriate. For example, as a color developer for leuco dye,
Examples include phenolic compounds, triphenylmethane compounds, sulfur-containing phenolic compounds, carboxylic acid compounds, sulfone compounds, urea or thiourea compounds, etc. For details, see, for example, Paper and Pulp Technology Times (/yrz
year)≠2-tp page and tj-70 page.

Among these, the melting point is jo 'C-,zso
oC is preferred, and water-soluble phenols and organic acids of to'c-0C are particularly desirable.

It is preferable to use two or more color developers in combination because the solubility increases.

Among the color developers used in the present invention, particularly preferred ones are represented by the following general formulas CI] to [■].

〔■゛〕

C1H2H+ 1 m=o~co, n=λ~/l [■] R1 is an alkyl group, an aryl group, or an aralkyl group, and a methyl group, an ethyl group, and a butyl group are particularly preferred.

(III) R2 is an alkyl group, especially a butyl group, a pentyl group,
Heptyl and octyl groups are preferred.

(IV) R3 is an alkyl group or an aralkyl group.

In the present invention, a color developer is dissolved in an organic solvent that is sparingly soluble or insoluble in water, and then mixed with an aqueous phase containing a surfactant and having a water-soluble polymer as a protective colloid, and emulsified and dispersed. Preference is given to using it in the form of a dispersion.

The organic solvent for dissolving the color developer can be appropriately selected from among high-boiling point oils, and in addition to maleic acid esters and phthalic acid esters, in particular, organic solvents that have two or more benzene rings and the number of heteroatoms can be used. An oil having a basic constant or less is preferable.

Such oils include compounds represented by the following general formulas (V) to (■), triallylmethane (e.g., tritolylmethane, tolyldiphenylmethane), terphenyl compounds (e.g., terphenyl), and alkylated diphenyl ethers. (e.g. Eva, Furovir diphenyl ether),
Examples include hydrogenated terphenyl (eg, hexahydroterphenyl), diphenyl ether, and the like.

(V) In the formula, R1 is hydrogen or an alkyl group having a carbon number of /-/r,
R represents an alkyl group having a carbon number of / to /I. pl, ql
represents an integer from / to μ, and the total number of alkyl groups is within μ.

In addition, the alkyl group of R and H is preferably an alkyl group having carbon number/~r.

In the formula, R is a hydrogen atom or an alkyl group having carbon number /-/λ,
R is an alkyl group having /-/2 carbon atoms.

n represents l or λ.

2% Q2 represents an integer between / and . When n = /, the total number of alkyl groups is within three, and when n = 2, the total number of alkyl groups is within four.

(■) In the formula, R and R represent a hydrogen atom or the same or different alkyl groups having 7 to /r carbon atoms.

m represents an integer of /-/J. p3 and q3 represent an integer of 1 to 3, and the total number of alkyl groups is 3 or less.

In addition, the alkyl group of R5 and R6 is particularly preferably an alkyl group having 2 to q carbon atoms.

Examples of the compound represented by formula (V) include dimethylnaphthalene, diethylnaphthalene, and diimpropylnaphthalene.

Examples of the compound represented by formula (Vl) include dimethylbiphenyl, diethylpiphenyl, diisopropylbiphenyl, and diisobutylpiphenyl.

Examples of compounds represented by formula (■) include /-methyl-
/-dimethylphenyl-/-phenylmethane, /-ethyl-/-dimethylphenyl-/-phenylmethane, /-
Propyl-/-dimethylphenyl-/-phenylmethane is Ii Keralel.

It is also possible to use the above oils together or with other oils.

In the present invention, an auxiliary solvent may be added to the above-mentioned organic solvent as a low boiling point dissolution aid. Particularly preferred examples of such co-solvents include ethyl acetate, isopropyl acetate, butyl acetate, and methylene chloride.

The water-soluble polymer to be contained as a protective colloid in the aqueous phase to be mixed with the oil phase in which the color developer is dissolved can be appropriately selected from known anionic polymers, nonionic polymers, and amphoteric polymers. However, polyvinyl alkone gelatin, cellulose derivatives, etc. are preferred.

Further, as the surfactant to be contained in the aqueous phase, one can be appropriately selected from anionic or nonionic surfactants that do not cause precipitation or aggregation by interacting with the above-mentioned protective colloid. .

Preferred surfactants include sodium alkylbenzenesulfonate (eg, sodium lauryl sulfate), dioctyl sodium sulfosuccinate, polyalkylene glycol (eg, polyoxyethylene nonylphenyl ether), and the like.

The emulsified dispersion of a color developer in the present invention is produced by mixing an oil phase containing a color developer and an aqueous phase containing a protective colloid and a surfactant by means of ordinary methods used for fine particle emulsification, such as high-speed stirring and ultrasonic dispersion. You can easily get the mixing and dispersion using the name.

A melting point depressant for a color developer may be added to this emulsified dispersion as appropriate. Some of these melting point depressants are
It also functions as a glass transition point regulator for the capsule wall. Examples of such compounds include droxy compounds, carbamate ester compounds, sulfonamide compounds, aromatic methoxy compounds, etc. For details, see
For example, it is described in Japanese Patent Application No. 79-2174t/ri0.

These melting point depressants are preferably O0! Although the melting point depressant and the color developer which lowers the melting point are preferably used in the same area. When adding at different locations, it is preferable to add 7 to 3 times the above amount.

The heat-sensitive recording material of the present invention contains silica, barium sulfate, titanium oxide, aluminum hydroxide, zinc oxide,
Pigments such as calcium carbonate, fine powders such as styrene beads, urea-melamine resin, etc. can be added, but in order to maintain the transparency of the heat-sensitive layer, additives are added on top of the heat-sensitive layer mainly to improve storage stability and stability. It is preferable to provide a desired protective layer by a known method and add the compound to this protective layer. For more information about the protective layer, see, for example, "Paper/ξrupu Technology Times" (
/ri♂! 2013, issue), pages 2 to 4.

Similarly, metal soaps can also be added to prevent sticking. The amount used is 0.2A-7g
/m2.

The heat-sensitive recording material of the present invention can be coated using a suitable binder.

Binders include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, gum arabic, gelatin, polyvinylpyrrolidone, casein, styrene-butadiene latex, acrylonitrile-butadiene latex, polyvinyl acetate, polyacrylic acid ester, ethylene-vinyl acetate, etc. Various emulsions such as polymers can be used. The amount used is o, r~s g/m2 as solid content.
It is.

The heat-sensitive recording material of the present invention is produced by preparing a coating solution containing microcapsules containing a color former, main components of a dispersion in which at least a color developer is emulsified, and other additives such as a binder. Bar coating, blade coating, air knife coating, gravure coating,
After coating and drying using coating methods such as roll coating, spray coating, and dip coating, the solid content is λ, j ~ confirmed!
It is manufactured by providing a heat-sensitive layer of g/m2.

The heat-sensitive layer of the heat-sensitive material produced in this way surprisingly has very good transparency, although the reason is not clear.

(Effects of the Invention) The proofing recording material of the present invention has high thermal sensitivity;
Images can be formed using a facsimile printer by heating with a thermal head. Therefore, each color separation image can be quickly obtained using a completely dry, maintenance-free, and compact thermal printer, making overlay-type color proofing extremely easy.

(Examples) The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited thereto.

Example / Separating sheet for cyan color development ■ Preparation of capsule liquid The following compound basic colorless dye (Blue◆2 θθ manufactured by Yamada Kagaku ■) /4 parts /-Phenyl-/-Xylylethane! j part methylene chloride 15 parts Sumisorb 200 (ultraviolet absorber manufactured by Sumitomo Chemical ■) - 2 parts Takenate D-/10N (manufactured by Narita Pharmaceutical Company ■) 60 parts were mixed,
It was added to an aqueous solution consisting of 100 parts of polyvinyl alcohol ♂ weight-based aqueous solution and <10 parts of distilled water, and then emulsified and dispersed at 20°C to obtain an emulsion having an average particle size/μ. Next, the obtained emulsion was continuously stirred at qθ0C for 3 hours to obtain capsule liquid C.

■ Preparation of color developer dispersion A (emulsified dispersion) 2 parts of color developer (a) and 4 parts of (b) represented by the following structural formula are heated in a room (c).
It was dissolved in 30 parts of phenyl-7-xylylethane and 30 parts of ethyl acetate. The obtained developer solution was mixed with polyvinyl alcohol/M aqueous solution/θθ part and water/
jθ part, and sodium dodecylbenzenesulfonate 0.3
% of the aqueous solution, emulsified and dispersed, and the particle size is 0. ! An emulsified dispersion of μ was obtained.

Color developer (a) Color developer (b) Color developer (C) 4Hg ■ Preparation of coating liquid ``Capsule liquid!'' was obtained by mixing 0 parts.

■ Preparation of Sheet A coaxially stretched polyethylene terephthalate film with a thickness of 7-iμ was used as a transparent support, and after corona treatment was applied to both sides, a coating solution was applied at a dry weight of /Jg/m2. A protective layer was provided to obtain a cyan coloring sheet.

Composition of (protective layer) Silica-modified polyvinyl alcohol (PVA R210s manufactured by Ri2shi ■) / part (solid content) Colloidal silica (Snowtex 30 manufactured by Nikki Kagaku ■) /, 3 parts (solid content) Zinc stearate (Middle East) Hydrin Z-7 manufactured by Yushi ■ 0102 parts (solid content) Paraffin wax (Hydrin P-7 manufactured by Seika Yushi ■) 0102 parts (solid content) ■ Measurement of transparency Manufactured by Nippon Seimitsu Kogyo 3, integrating sphere method HTR Haze was measured with a meter. Haze degree/! It showed good transparency in both cases.

■ Coloring performance Matsushita Densen facsimile printer (UF-/.

00), gradation recording was performed using a cyan color separation positive as an original.

A cyan color with a maximum transmission density of 7.4t was obtained.

Example - Color separation sheet for magenta color development Example/- In , the following compound (CIBA Pergascript Red 1-) was used as a basic colorless dye.
A magenta coloring sheet was obtained in the same manner as in Example except that A-B) was used. The same evaluation as in Example 1 was carried out to obtain an image with a background haze degree of 4% and a maximum color density of /,j.

Example 3 A yellow coloring sheet was obtained in the same manner as in Example 1, except that a compound having the following structure was used as the basic colorless dye in Example 2. The same evaluation as in Example 1 was carried out to obtain an image with a background haze degree of 74 s% and a maximum color density of O1♂.

EXAMPLE 4 A gray/black sheet was obtained in the same manner as in Example 1, except that a compound having the following structure was used as the basic colorless dye in Example 2. The same evaluation as in Example 1 was carried out, and the background haze degree was 73%, and the maximum color density was 7.
Two images were obtained.

Example! By superimposing each color separation sheet obtained in Examples 1 to 2 on a white paper and looking at it, color proofing could be done quickly and easily.

Claims (1)

[Claims] Each color separation sheet consists of microcapsules containing a color former as a core material and a coating solution containing an emulsified and dispersed color developer, which is coated on a transparent support and dried to form a thermosensitive color forming layer, and then a protective layer is laminated. A color proofing sheet characterized by comprising a heat-sensitive color forming unit layer.