JPH0239048A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To obtain the plate wear, the developing property and the sensitization of a photosensitive material which are fundamental characteristics required for a printing plate by incorporating an alcohol soluble rosin modified resin in the photosensitive material contg. a diazo type photosensitive agent. CONSTITUTION:The alcohol soluble rosin modified resin is incorporated in the photosensitive material contg. the diazo type photosensitive agent. The photosensitive material is not specified. If the diazonium compd. is used for the photosensitive agent, all photosensitive agents contg. the compd. are effectively used. The photosensitive material is preferably constituted of the diazo type photosensitive agent and a binder. The diazo type photosensitive agent may be used by optionally selecting from the diazonium compds. which are usually used for the diazo type photosensitive agent. Thus, the practical printing plate which has the excellent plate wear and the developing property and the remarkably improved sensitization is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel photosensitive composition suitable for the production of printing plates. More specifically, the present invention has excellent mechanical strength and alkali developability, and
In particular, the present invention relates to a photosensitive composition that can form image areas with improved oil sensitivity.

Conventional technology Conventionally, diazonium compounds have often been used as photosensitizers for photosensitive materials in the making of negative printing plates, and diazo resins, typified by condensates of p-diazodiphenylamine and formaldehyde, are particularly preferred for practical purposes. It is used as a thing.

The plate-making method involves coating a diazo resin as described above on a support to form a photosensitive layer, then passing a negative film through this photosensitive layer to form an image by exposing it to ultraviolet rays, and then exposing the unexposed areas. A method has been used in which a photocured image area is formed by dissolving and removing it with an aqueous developer.

However, when a photosensitive layer is formed using a photosensitive material using the diazo resin alone, the photocured image area formed by exposure has low mechanical strength and poor rigidity. A resin with good abrasion resistance is blended into the resin.

By the way, printing plates using photosensitive materials containing these cyan photosensitizers are required to be resistant to #sensitivity, oil sensitivity, alkaline developability, etc., and various photosensitive materials are used to meet these requirements. materials are proposed. That is, when a diazo resin is used alone in the photosensitive layer, the photocured image area formed by exposure has low mechanical strength and mHJ
2-hydroxy-3-2 enoxypropyl acrylate) or 112
A photosensitive material made of a polymer containing monomer units such as -hydroxy-3-methylphene/xypropyl acrylate and a diazo photosensitizer is known (Japanese Patent Publication No. 51656/1983). 1 mechanical strength is high because it has a benzene ring in the unit.
Although it is possible to provide a printing plate with excellent rI# printing properties, it has the drawbacks of extremely low alkali developability and insufficient oil sensitivity for practical use.

Also known is a photosensitive composition (Japanese Unexamined Patent Publication No. 118802/1983) comprising a 2-hydroxyethyl methacrylate homopolymer, a copolymer such as acriminitril or methacrylate tril, and a diazonium compound. has excellent rigidity resistance and developability, but has drawbacks such as low oil sensitivity because the image area is easily swollen by the developer.

As described above, conventional photosensitive materials containing diazo photosensitizers cannot be said to fully satisfy the basic properties required of printing plates, such as rigidity resistance, developability, and oil sensitivity.

Problems to be Solved by the Invention The present inventors have conducted extensive research in order to overcome the drawbacks of the prior art described above and to develop a photosensitive composition suitable for manufacturing printing plates.As a result, the inventors have developed an alcohol-soluble rosin. It was discovered that the purpose could be achieved by a photosensitive composition containing a modified resin, and based on this knowledge, the unreleased product was completed.

The invention was made for the purpose of providing a photosensitive composition which can provide a printing plate having excellent properties and developability, and particularly improved oil sensitivity.

Means for Solving the Problems To summarize the present invention, 1. The present invention relates to a photosensitive composition characterized by blending an alcohol-soluble rosin-modified resin into a photosensitive material containing a cyan-based photosensitizer. It is something.

Hereinafter, the configuration of the present invention will be explained in detail.

(Photosensitive material) In the photosensitive composition of the present invention, there are no particular restrictions on the photosensitive material containing a diazo-based photosensitizer, and any material containing a diazonium compound as a photosensitizer can be effectively used. Kotoka degoru. Specifically, a photosensitive material composed of a cyan-based photosensitizer and a binder can be preferably used.5 As the above-mentioned diazo-based photosensitizer, among the diazonium compounds conventionally used as diazo-based photosensitizers, Any one can be selected and used.

Such diazonium compounds include, for example, 4-cyandiphenylamine, 4-diazo-3-methyldi7-diphenylamine, 4-diazo-4'methoxydiphenylamine, 4-cyaso-3-methyl-4'-ethoxydiphenylamine, and formaldehyde or Condensates with acetaldehyde can be mentioned, but in particular, these diazonium compounds and organic sulfonic acids such as benzenesulfonic acid, toluenesulfonic acid, naphthalenesulfonic acid, propylnaphthalenesulfonic acid, 2-hydroxy-
Salts with 4-methoxyhenlafuenone-5-sulfone a and the like are preferably used.

Further, the above-mentioned binder is prepared from binder components as shown below.

That is, the binder components include acrylic acid, methacrylic acid, alkyl acrylate, furkyl methacrylate, acrylonitrile methacrylate, tolyl hydroxyalkyl acrylate, hydroxyalkyl methacrylate, hydroxyalkoxy acrylate, hydroxyalkoxy methacrylate, hydroxyalkyl acrylate, dihydroxyalkyl methacrylate, Hydroxyalkoxyprobyl acrylate.

Examples include polymerizable unsaturated compounds such as hydroxyalkoxypropyl methacrylate, ε-caprolactam-modified β-hydroxyalkyl acrylate, and (-caprolactam-modified β-hydroxyalkyl methacrylate).

In addition to these polymerizable unsaturated compounds, maleic acid,
7 Unsaturated carboxylic acids such as malic acid and itaconic acid, unsaturated fatty acid amides such as acrylamide and methacrylamide, methyl vinyl ethers Styrenes such as styrene and α-methylstyrene 2 Vinyl esters such as vinyl acetate and hinyl propionate etc. can also be used as constituents.

These may be used alone or in combination of two or more.

There are no particular restrictions on the method for producing Painter, and for example, the above-mentioned binder components may be dissolved in a suitable solvent, and a conventionally used radical polymerization initiator such as ambiisobutyronitrile or benzoyl peroxide may be added. ,
It can be obtained by performing polymerization by heating as necessary. The binder thus obtained has a molecular weight in the range of 10,000 to 500,000, preferably 30,000 to 100,000. In order to impart alkaline developability to /Hingoo, it is preferable to adjust its acid value to 10 to 150.

In addition to the binder prepared as described above, in the present invention, for the purpose of improving various properties required for printing plates, we also use a styrene resin, a urethane resin, and a urethane resin that does not have an acid value. Acrylic resin, rosin resin, etc. may be added.

In this case, the amount added is 30 plus 1 to the binder.
% or less is preferable.

In order to prepare the photosensitive material containing the diazo photosensitizer used in the photosensitive composition of the present invention, the diazo photosensitizer described above is usually added in 5 to 4
Qii%, preferably in the range of IO to 1% by weight. If the content is less than 5% by weight, the mechanical strength of the image area may be lowered, and if it exceeds 4% by weight, the developability tends to decrease, so neither is preferable.

In addition to the above-mentioned diazo-based photosensitizers and paint goo, the prepared photosensitive material may contain additive components commonly used in conventional photosensitive materials, such as dyes, pigments, plasticizers, fillers, stabilizers, etc. Agents, etc. can be added.

(Resin component) Next, the alcohol-soluble rosin modified resin component used in the present invention will be explained.

As the alcohol-soluble rosin-modified resin component, any rosin-modified resin that is soluble in alcoholic solvents can be used, but specifically, addition reaction products of rosin compounds and maleic anhydride and alcoholic An esterified product obtained by mixing a compound having a hydroxyl group, heating, and back-esterifying is preferable.The method for obtaining this esterified product will be described below.The alcohol-soluble rosin modified resin used in the present invention is It is not limited to this esterified product.

The rosin compound constitutes rosin, and includes, for example, abietic acid, neo-abietic acid, pimaric acid, in-α-pimaric acid, and levo-pimaric acid. These may be used alone or in combination of two or more.

An addition reaction product can be easily obtained by heating a rosin compound with maleic anhydride, and this addition reaction product can be produced without a solvent, without a catalyst (if necessary,
dO2, PzOs, etc. may be used as a catalyst,
), the mixture of rosin compound and maleic anhydride was
It can be obtained by heating reaction at 0 to 250°C.

There is no particular limitation on the addition rate of maleic anhydride to the rosin compound, but it is preferable that maleic anhydride is added at a ratio of 5 to 50% by weight to the rosin compound.
If this proportion is less than 5% by weight, it is undesirable because even if the adduct is esterified with a polyhydric alcohol, it becomes difficult to be soluble in alcohol.2On the other hand, if it exceeds 50% by weight, the acid value becomes too high for practical use. This is not preferable because it becomes impossible to obtain good developability and oil sensitivity.

Next, the obtained addition reaction product is mixed with a compound having an alcoholic hydroxyl group and heated to prepare an esterified product.

Examples of the compound having an alcoholic *acid group to be esterified with the addition reaction product described above include ethylene glycol, diethylene glycol triethylene glycol tetote ethylene glycol propylene glycol.

dipropylene glycol, trimethylene glycol, butanediol 1.5-bentanediol.

Examples include polyhydric alcohols having a valence of two or more such as hexylene glycol octylene glycol, glycerin glyceryl monoacetate, glyceryl monobutyrate trimethylol propane 1,2,6-hexandriol. These may be used alone or in combination of two or more types, but among these, trihydric alcohols are particularly preferred because they can provide practical developability and oil sensitivity.

An esterified product, which is one of the alcohol-soluble rosin-modified resins, is prepared as described above, but as described above, the alcohol-soluble rosin-modified resins used in the present invention are not limited to this. Even if a rosin-modified resin is used, it is preferable that the alcohol-soluble rosin-modified resin contains 80% or more of the esterified product; if it is less than 80% by weight, a product with excellent oil sensitivity cannot be obtained. Preferred l/)
.

In the present invention, in addition to the above-mentioned esterified products, Harinister MSR-4, Harinister MT, and Harinister MT, which are reprinted as alcohol-soluble rosin-modified resins, are used.
-80, Harimak FX25, Harimak 2723,
Harimac AS-5, Harimac AS-9 (both
(manufactured by Harima Kasei Kogyo Co., Ltd.) can also be used.

In the present invention, the alcohol-soluble rosin modified resin is
If the acid value is in the range of 5.2 to 200, it is not preferable because it requires 3tz to achieve both alkali developability and oil sensitivity.

(Production method of photosensitive composition) The photosensitive composition of the present invention can be obtained by blending the alcohol-soluble rosin-modified resin described above with the photosensitive material containing the diazo photosensitizer described above. The amount of the alcohol-soluble rosin-modified resin is 1 part for the photosensitive material containing the diazo photosensitive agent.
35% to 35% by weight, particularly 5 to 20% by weight is preferred. If this amount is less than 1% by weight, the effect of improving oil sensitivity will be lowered, and on the contrary, if it exceeds 35% by weight, the stiffness resistance will be significantly reduced. Unfavorable for degrading.

(Method for producing a printing plate) In order to produce a printing plate using the photosensitive composition of the present invention, first, a photosensitive material containing the above-mentioned diazo photosensitizer and an alcohol-soluble rosin-modified resin are dissolved in a solvent. After coating this on the substrate and drying it to form a photosensitive layer,
This photosensitive layer is irradiated with ultraviolet rays through a negative film (that is, subjected to image-forming exposure), and then developed using an alkaline developer to dissolve and remove the unexposed areas. can be formed and a printing plate obtained.

As the solvent, for example, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, etc. can be used, and as the substrate, for example, polyethylene film, zinc plate, copper plate, aluminum plate, glass plate. 6 Examples Example 1 After mixing 302 g of abietic acid, which is a rosin compound, and 19.6 g of maleic anhydride in a flask equipped with a reflux tube, the mixture was heated at 180 to 200°C for 45 minutes. By heating and reacting, 320 g of a black water maleic acid adduct of 7-bietic acid (addition rate 20%) was obtained. 6 Next, 42 g of trimethylol-butylene was added thereto, and the mixture was heated at 200°
By carrying out an esterification reaction with C for 3 hours, an alcohol-soluble rosin-modified maleic I! consisting of a maleic anhydride adduct of abietic acid and an esterified product of trimethylolprobant (7) was produced. #330g of resin (r) was obtained. The acid value of this resin is 40, the weight average molecular weight is 1,000, and 5% for all of methyl alcohol, isopropyl alcohol, and ethylene glycol monomethyl ether.
It had a solubility of 0% by weight or more.

Next, the following photosensitive composition was prepared using this alcohol-soluble rosin-modified maleic acid resin (I).

(1) Acrylic copolymer (acid value 50, weight average molecular weight 90,000)...2g (2 alcohol-soluble rosin-modified maleic acid resin (1
) ...0.3g (3) 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid ring of the condensate of p-diazonium diphenylamine and paraformaldehyde ・
...0.5g (4) Victoria Pure Blue BOH [
Hodogaya Chemical Industry Co., Ltd. J...0.04g (5) Pluronic L-64 [Asahi Denka Co., Ltd.]...0.02g (6) Ethylene glycol monomethyl ether...
30g Then, place the above (1) on a 0.24mm thick aluminum plate.
A photosensitive solution obtained by mixing (6) to (6) was applied to a dry weight of 1.8 g/m' and dried to form a photosensitive layer on an aluminum plate. The aluminum plate was previously mechanically grained with a nylon brush, anodized with sulfuric acid, and treated with silicate.

Next, a negative film was applied to the photosensitive layer and exposed to light for 30 seconds from a distance of 70 cm using a 2 kW metal halide lamp. At this time, exposure printout was clearly identified under yellow fluorescent lighting. After exposure, apply 400 ml to a developer having the composition shown below at room temperature.
After immersion for 0 seconds, an image pattern was formed on the aluminum plate by washing with water to obtain a lithographic printing plate.

[Developer composition]

Hensyl alcohol 1.5 g 40% by weight aqueous sodium silicate solution 0.5 g Sodium nitite 0.5 g Inpropylnaphthalenesulfone sodium chloride 05 g Water
Next, 97 g of non-image area protection gum liquid "rD-4s" (manufactured by Tokyo Almetal Kogyo Co., Ltd.) was applied to the entire surface of the obtained planographic printing plate using a sponge, and then heated at 60"C for 2 hours.
Dry for a minute.

Using the lithographic printing plate obtained in this way, using a 5% by weight aqueous isopropyl alcohol solution as a dampening water and using offset oil-based ink N Offlin LM-FK Sumisho 5 (manufactured by Moroboshi Ink Co., Ltd.), sheet-fed printing was performed. Offset Hamada Star CDX
900 (When printed on high-quality paper manufactured by Hamada Seisakusho Co., Ltd., the number of copies wasted due to poor ink coverage at the beginning was 10 copies, and after that, 100,000 copies were printed with no ink adhesion defects, smudges, fading, etc.) I was able to get more than that.

Thereafter, this lithographic printing plate was stored with a gum, and after 7 days, printing was performed in the same manner, but the number of paper losses and printing durability remained unchanged. Furthermore, when the lithographic printing plate before exposure treatment was treated for 7 days at a humidity of 80% and a temperature of 40°C, no decrease in sensitivity, developability, or oil sensitivity was observed, and the storage stability was excellent. It was confirmed that

Comparative Example 1 A lithographic printing plate obtained in the same manner as in Example 1 except for excluding the alcohol-soluble rosin-modified maleic acid resin (I) used in Example 1 had a paper loss of 60% due to poor initial inkling. Occurred. Also, those stored with cam pull for 7 days are 1
Even after printing more than 00 copies, the ink was completely dry.

Example 2 Using the alcohol-soluble rosin-modified maleic acid resin (r) synthesized in Example 1, the following photosensitive composition was prepared in the same manner as in Example 1.

(1) 2-hydroxyethyl methacrylate/acrylonitrile/methyl methacrylate/methacrylic acid = 5
Acrylic copolymer synthesized from 0/20/2515 parts by weight (acid value: 351, weight molecular weight: 120,000)
...1.5g (2) Alcohol-soluble rosin-modified maleic acid resin (I) ...0.
3g (3) p-)Luene-nurphonate of condensate of p-diasonium diphecolamine and paraformaldehyde...0, 25g (4) Oil Blue-#603 [manufactured by Orient Chemical Industry Co., Ltd.]
...0.08 g (5) Ethylene glyco-spider/methyl ether ...25 g (6) Methanol ...5 g Next, on the aluminum plate used in Example 1, the above (1
) or 6) Apply the resulting photosensitive solution so that the weight after drying is 2.48 g/rn',
By drying, a photosensitive layer was formed on the aluminum plate, and a planographic printing plate was obtained.

This lithographic printing plate was exposed in the same manner as in Example 1, and then developed using an alkaline developing solution DN-3C (manufactured by Fuji Photo Film Co., Ltd.) diluted with water at a ratio of 1:2 (volume ratio) for 40 minutes at room temperature.
As a result of continuous development treatment by dipping for seconds, it was possible to obtain more than 100,000 copies of prints without stains during printing, even when using a developer that processed an unexposed planographic printing plate to 10rn'/distance. .

Example 3 Instead of the alcohol-soluble rosin-modified maleic acid resin (I) used in Example 1, Harinister MSR-4, which is a commercially available alcohol-soluble rosin-modified maleic acid resin, was used.
(manufactured by Yokoma Kasei Kogyo Co., Ltd.) [The following photosensitive composition was prepared using an acid value of 120 to 1401 weight average molecular weight and 0OQI.

(1) Acrylic copolymer synthesized from ethyl methacrylate/acrylonitrile/methacrylic acid = 50/35/15 parts and 1 part (acid!1lIi801 weight average molecular weight 60,000)...2
, 3'g (2 N Harrier-MSR-4...0.2g
(3) p-diazodiphenylamine k Hexafluorophosphate of condensate with halaformaldehyde
...0.25g (4) Crystal violet powder C manufactured by Hodogaya Chemical Industry Co., Ltd. ...0.02g (5)
Ethylene glycol monomethyl ether...15g (6) Diethylene glycol monomethyl ether...
15g The photosensitive solution obtained by mixing (1) to 6) above was applied onto the aluminum plate used in Example 1 so that the weight after drying was 1.5g/d, and dried. By doing so, a photosensitive layer was formed on the aluminum plate, and a planographic printing plate was obtained.

Next, it was exposed to light in the same manner as in Example 1, and then immersed in a developer having the composition shown below for 20 seconds at room temperature, and then washed with water to obtain a lithographic printing plate on which an image was formed.

[Development f! [1 product] Ethylene glycol mono-2 enyl ether...6g Sodium metasilicate...1g Sodium lauryl sulfate...4g water
...
94g Then, using this planographic printing plate, DICH50
When printing on high-quality paper using a Heidel GTO printer using offset oil-based ink (manufactured by Dainippon Ink and Chemicals) using 0 etch liquid (manufactured by Dainippon Ink and Chemicals) as dampening water, initial adhesion was observed. We were able to obtain over 100,000 copies of printed matter free of defects and stains.

Example 4 After mixing 302 g of iso-α-pimal #1, which is a 0-dine compound, and 39 g of maleic anhydride in a flask equipped with a reflux tube, the mixture was heated and reacted at 180 to 200°C for 45 minutes to produce in-α-pimal. 330g of maleic anhydride adduct of acid (addition rate 40%) was obtained.Next, 50g of glycerin was added to this and an esterification reaction was carried out at 200°C for 3 hours to obtain maleic anhydride adduct of iso-α-pimaric acid. Alcohol-soluble rosin-modified maleic acid resin (11) 320 consisting of an esterified product of and glycerin
I got g. This resin had an acid value of 120ffi-ffi and an average molecular weight of 1,200, and had a solubility in all of methyl alcohol, isopropyl alcohol, and ethylene glycol monomethyl ether of 50% by weight or more.

Next, a photosensitive solution 3J was prepared in the same manner as in Example 3 except that 0.7 g of the alcohol-soluble rosin-modified maleic acid resin (H) described above was used in place of Harinister MSR4 used in Example 3. A lithographic printing plate was obtained. When printing was carried out in the same manner as in Example 3 using this lithographic printing plate, more than 100,000 copies of printed matter without any initial inkling defects or stains could be obtained.

Effects of the Invention The photosensitive composition of the present invention has excellent printing durability and developability, and can provide a practical printing plate that is highly oil-sensitive and highly saturated, especially compared to conventional printing plates.

Claims (5)

[Claims] (1) A photosensitive composition comprising a photosensitive material containing a diazo photosensitizer and an alcohol-soluble rosin-modified resin. (2) Photosensitivity according to claim 1, wherein the alcohol-soluble rosin-modified resin is an esterified product obtained by subjecting an addition reaction product of a rosin compound and maleic anhydride to an esterification reaction with a compound having an alcoholic hydroxyl group. Composition. (3) The photosensitive composition according to claim 2, wherein the compound having an alcoholic hydroxyl group is a polyhydric alcohol. (4) The photosensitive composition according to claim 1 or 2, wherein the alcohol-soluble rosin-modified resin has an acid value of 5 to 200. (5) The photosensitive composition according to claim 1, wherein the alcohol-soluble rosin-modified resin is blended in a proportion of 1 to 35% by weight based on the photosensitive material containing the diazo photosensitizer.