JPS58181039A - Photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE:To enhance the shelf stability, printing resistance and developability by using a photosensitive layer consisting of water insoluble resin and a polymer having a specified structure and a specified acid value. CONSTITUTION:A polymer film of polyacrylic acid or polymethacrylic acid having <=0.5mum thickness is formed on an anodically oxidized Al plate. A photosensitive layer consisting of water insoluble diazo resin and a polymer having 10-100 acid value and contg. structural units represented by general formula I (where R1 is H or methyl) and <=50wt% structural units represented by general formula II (where R2 is H or alkyl, and (n) is an integer of 1-10) is laminated on the polymer film. The preferred content of the structural units represented by general formula I is 5-30wt%, and that of the structural units represented by general formula II is 20-50wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive lithographic printing plate, and is particularly related to a diazo-based photosensitive lithographic printing plate that has good storage stability, one-time printing durability, and improved dust removal properties. &It's shocking.

The photosensitive layer of the photosensitive lithographic print 11 and below (referred to as PM plate) includes:
Generally, diazo thread-sensitive compositions are often used. The diazo-based material 4C of the Hora 11M28 version is naphthoquinonediazide, and the diazo-based gjt material of the negative PS version is a condensation product of 4-diazodiphenylfmine, 4-diazo-5-methquinediphenylamine, and paraformaldehyde. (
diazo-fat and neji) are mainly used. By mixing this diazo W resin with a polymer compound, it is possible to make a plate printing plate with good printing power without using lacquer, and it can also be easily developed with an aqueous solution containing a surfactant. It is used as a photosensitive material for NEKA-type PS plates. Diazo41! The resins are classified as follows depending on the partner polymer compound with which they undergo a photocrosslinking reaction, and form the photosensitive layer of a non-reactive PS plate.

(1+ A combination of a water-insoluble polymer compound having an alcoholic hydroxyl group and a water-insoluble s) resin.

Examples of water-insoluble polymeric compounds having alcoholic hydroxyl groups include Epoxy 7 Seijiji (% Kosho 47-1167), 2-hydrogyalkyl methacrylate, acrylonitrile, a multi-component acrylic copolymer consisting of methacrylate and MEC 11-ruic acid, and polyvinyl Formal resin, polyhinyl phthyral &&, folipinyl chlorbensal, 2-
Multi-component acrylic co-electrolytic composite consisting of hydroquine-6-fetuquinprobyl acrylate, methyl methacrylate, hydroquinone methacrylate, acrylonitrile and methacrylic acid (Japanese Patent Publication No. 52-7564, Japanese Patent Publication No. 52-7564, Japanese Patent Publication No. 52-7564)
5-34929, Japanese Unexamined Patent Publication No. 54 (1973) = 8840! S, % Sekisho 55-142!552) township is known.

(2) A combination of a water-insoluble polymer compound having a phenolic hydroxyl group and a water-insoluble diazo resin.

Examples of polymeric compounds having phenolic hydroxyl groups include phenol resins (% Kōsho 47-1167), multi-component acrylic copolymers consisting of N (4-hydroxyphenyl) methacrylamide, acrylonitrile, methyl methacrylate, and methacrylic acid (% Kōsho 47-1167); 54-98414, JP-A-56-107234). (3) Combinations of other water-insoluble polymer compounds and water-insoluble diazo Il&.

Other water-insoluble polymer compounds include polyamide,
Polystyrene, polyester, polyacetate, poly9
Rethane, polyvinyl acetate (Japanese Patent Publication No. 47-1147, Japanese Patent Publication No. 56-9697), N-vinylpyrrolidone, acrylonitrile, multi-component acrylic copolymer consisting of methyl methachloride (% open 1982-27802), methyl methacrylate, acrylonitrile Combinations belonging to (21) and (3) above, in which multi-component acrylic copolymers consisting of methacrylic acid and methacrylic acid (Japanese Unexamined Patent Publication No. 56-4144) are known, are more difficult to combine with a diazo compound than combinations belonging to (11) above. Because the bridge density is low, solvent resistance is weak, and if you try to have solvent resistance, the developability with an aqueous developing solution containing a surfactant will be poor, making it difficult to make a good NEKA MPS plate. has many problems.

The water-insoluble diazo resin used in the negative 28th plate is a combination of diazo 41I fat and an organic sulfonic acid such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, 2-methquine-4-hydroxybenzophenone-5-sulfonic acid, or a salt thereof. No reaction products such as fluoroboric acid, thiocyanic acid, hexafluorophosphoric acid, etc.! The photosensitive compositions of these diazo negative PS plates are coated on a hydrophilic support such as paper, chrome, or aluminum. P81
JL is made, but when Ik cloth is applied to an anodized aluminum plate to increase printing durability, the adhesion is too good, so if it has been applied for several months or has been stored at high temperatures, When image high light 311 is used, the unexposed areas are eluted, but there is a dust phenomenon that causes ink stains. To solve these problems, oxalic acid ( Tokuko Sho 57-8460) Ya!
By mixing phosphoric acid (15102, 1972!S) or polymeric Il acid (1072, 1972!S8), it is possible to remove ink stains after dust images on the Neka-type PS plate over time. It is known that there is no need for it, but it is still not enough.

As a result of intensive research to solve the above problem, the inventors of the present invention have developed a seawall α5μ on anodized aluminum plate.
A polymer film of the following polyacrylic acid or methacrylic acid is formed, and a water-insoluble diazo resin and a structural unit represented by the following general formula (1) and the following general formula of 50 weight or less are formed on the polymer film. Acid value 1 containing the structural unit represented by (n)
OR has discovered that a diazo negative IIP8N with good stability over time and improved printing durability and developability can be obtained by stacking photosensitive layers made of 0 to 1000 polymers.

0HR.

1 R (In each of the above formulas, R1 represents water or a methyl group, R
8 represents a hydrogen atom or an aluminum group, and n represents an integer of 1 to 10.) The anointed aluminum plate used in the present invention is:
After the aluminum plate is grained by bluff polishing or electric scale grinding, it is anodized in an anodizing bath of ii#, hydrochloric acid, phosphoric acid, boric acid, or a mixed acid, and is then anodized with silicate or zirconium fluoride. It is treated with an aqueous solution of salt.

The polyacrylic acid or polymethacrylic acid used in the present invention has an average molecular weight of 5000 to 5000.

It is highly soluble, dissolves well in water, and hardly dissolves in solvents.

According to R￥f 1985-107238, it is stated that the storage stability of -P8wL is improved when 1 to 511% of polyacrylic acid is mixed into Ki 1IiI, a photosensitive composition made from diazo yarns. However, since polyacrylic acid is almost insoluble in solvents such as methyl cellosolve constituting the photosensitive liquid, polyacrylic acid is removed during the filtration process during the production of the photosensitive liquid. Therefore, variations occur in the storage stability of P8[f]. In addition, water-insoluble diazo** is difficult to decompose due to the low viscosity of the photosensitive solution. Therefore, when collecting and applying the sensory liquid to an aluminum plate using a roll coater, the blind side concentration of the photosensitive liquid is 1H1, taking into account the decomposition of the water-insoluble diazo resin.
It is necessary to adjust the temperature to 0 to 15 or more in order to produce a Pa plate with stable quality, and it is not possible to add and dissolve polyacrylic acid accordingly.〇Bo 11 Acrylic acid is mixed into the photosensitive solution and stored. In order to produce psWi with good stability, it is necessary to consider the solubility of polyacrylic acid and use a polymer compound that is easily soluble in water or methanol and a diazo photosensitive material. Even if a negative PS plate with storage stability is obtained with this photosensitive liquid composition, there is a problem in printing durability.

The thickness of the polymer film of polyacrylic acid or polymethacrylic acid used in the undercoat layer of the present invention is preferably α5μ or less; At mark -1, there is a risk that the th image area may be missing in spots. The thickness of the polymer film varies depending on the type of water-insoluble diazo resin used, and is appropriately selected from the above-mentioned range. For example, when using the reaction product of diazo tM fat and hexafluoro LI II phosphate, the city molecule! When a reaction product of a 0 diazo resin and 2-methoquino-4-hydroxypenzophenone-5-sulfonic acid is used, α1 to α2μ is preferable.

The polymer used in the present invention undergoes an efficient photo-crosslinking reaction with water-insoluble diazo III fat, has good water resistance and adhesion to aluminum plates after being anodized, and has photosensitive properties as an Ig agent.
Forms a film. Further, the unexposed area can be easily cleaned with a weakly alkaline aqueous solution containing a surfactant (surfactant ii).

The monomers containing the structural unit represented by the general formula (1) include 2-hydroxy-6-phenoxypropylacrylate, 2-hydroxy-3-methylphenoxypropylacrylate, and the corresponding methacrylate. In addition, 2-hydroxyethyl (meth)acrylate, hydroginepropyl (meth)acrylate, etc. are known as monomers forming the structural unit represented by general formula l).

The monomers that form the structural unit tube of the general formula [1] and [Rin] are methyl (meth)acrylate, styrene, Monomers such as benzyl acrylate, α-77-methyl acrylate, and acrylonide+1 are copolymerized as necessary, and further 6 (in order to make it developable with a weak alkaline aqueous solution containing a surfactant, 1) Unsaturated carboxylic acids such as hydrochloric acid, methacrylic acid, and maleic acid are copolymerized.

When the polymer compound containing the structural unit represented by the general formula (1) is efficiently photocrosslinked with diazo 11[1], it exhibits strong adhesion to the anodic-coated aluminum plate, and has excellent abrasion resistance. However, the general formula (1)
The monomer forming the structural unit represented by formula 1 is difficult to copolymerize with other acrylic monomers, and the polymerization solution thereof tends to gel. However, the monomer forming the structural unit represented by general formula l] When present, copolymers are easily formed with other monomers.

The content of the structural unit represented by general formula (1) is 5 to 50
If the weight is 30% or higher, the adhesion with the anodized aluminum plate is too strong, and the mechanical strength of the part becomes weaker than 5%.

The content of the structural unit represented by the general formula [yam] is 20 to 5
Zero weight is preferred. If the amount is 20% by weight or less, the general formula [1
] It is difficult to copolymerize with the monomer forming the structural unit shown by the formula, and if the weight coefficient is 50 or more, the adhesion to an anodized aluminum plate subbed with polyacrylic acid or polymethacrylic acid +1 oxide is poor. Due to the decrease in dust image, th
The ink receptivity is reduced by causing swelling ia in one part.

The acid value of the above polymer is preferably 10 to 100.

If the acid value is less than 10, the ms of a weakly alkaline aqueous solution containing a surfactant becomes slow and ink stains are likely to occur even after development is completed. If the acid value is 100 or more, the oil sensitivity of the -seed part is severely reduced, making it unsuitable for use in the photosensitive layer of lithographic printing -IJ)i[.

The molecular weight of the parent polymer is preferably in the range of 50,000 to 150,000.

Water-insoluble diazo*WI! used in the present invention! The above-mentioned organic sulfonates of diazo-11 fats and reaction products with inorganic salts can be used. In particular, diazo resin hexafluoro-11m or 2-methoxy-
4-Hydroxy/benzophenone - the reaction product with 5-sulfonate - is preferred. Since these water-insoluble diazo*Ws are soluble in solvents such as methyl cellosolve, dimethylformamide, and ethylene dichloride, a mixed solvent of these is used as the solvent constituting the photosensitive solution.

Oxalic acid, phosphorous acid, high-molecular organic acids, etc., which are conventionally added to photosensitive solutions, are difficult to dissolve in these solvents, and are difficult to dissolve in these solvents. Coating methods that require a photosensitive liquid with a high viscosity have many pinholes and uneven coating on the coated surface, and also cause variations in manufacturing loft in terms of storage stability.

In the present invention, in order to use a polymer film of polyacrylic acid or polymethacrylic acid that is completely soluble in water as the underlayer, some amount of diazo l1IT#I is synthesized, and when the dust rises due to the 411r fatification, It can also prevent ink stains. The content of the diazo compound is preferably 5 to 20% by weight relative to the polymer number. l! 6 (The performance of the PS plate can be improved by adding dyes, pigments, and photonic agents to the required 4 mm width.) , Japanese Patent Publication No. Sho 56-'59464, which consists of an anionic surfactant, benzyl alcohol, and a water bath containing a salt in water-soluble IL#, may be conveniently used, but there is no history. In order to efficiently remove dust, a present compound consisting of a water solution containing a 7'to11 acyl-ain addition salt and a surfactant is combined with phenylcerone, which was published in 1987, 1987,406.
Preferably, N solution is used.

The present invention will be described in detail below using the example of Sou #11, but the present invention is not limited thereto.

Actual example 1: Under a similar atmosphere, add 150 g of dioxane to 150 g of azo and isobutyronitrile, and heat to 80-85°C. Add 2-hydroxy/-5-phenoxy7-propylacrylate into it while stirring. 15.5A A mixture consisting of 2-hydroxyethyl methacrylate 411i, methyl methacrylate 215 g, α-cyan methyl acrylate 1877, and methacrylic acid 5I was added dropwise over a period of 1 hour, and after the addition was completed, the mixture was heated at 80 to 85°C for 2 hours. Stir. After the reaction, the mixture is cooled, diluted with a mixture of dioxane/methanol, and then poured into a large amount of water with stirring to precipitate the copolymer. This polymer is dissolved in methyl cellosolve, purified by pouring it into water, and vacuum dried to reduce the water content to 1% or less. The acid value of this multi-component acrylic copolymer was 286.

An aluminum plate with a thickness of α5cm was grained with a nylon brush, and then immersed in 10-inch caustic sorter water for 10 seconds and rinsed with water. After that, it was immersed in sulfur water for 5 seconds, desmutted, and then washed with water. This aluminum plate is 20% #2A/
dm" for S minutes. After that, it was treated with sodium silicate water for 50 minutes at 70°C, washed with water, and dried. Then, using a Whaler, a 11% polyacrylic acid aqueous solution (using polyacrylic # having a molecular weight of 8000) was applied. It was coated and dried at 60°C for 5 minutes.The film thickness of polyacrylic acid was 0.08μ. Suppose that the aluminum treated with this polyacrylic acid was treated with a photosensitive liquid Keholer having the following composition. Negative type 28 plate (11) was obtained by drying at 85°C for 3 minutes.On the other hand, for comparison and 17, 17 was applied to ll# super oxidized tongue 1 nialumbanium root soil without polyacrylic acid treatment. , Apply the photosensitive liquid in the same manner as above, and compare the ratio @ P8 version (2)
I got it. In both cases, the thickness of the photosensitive layer was t7a.

Photosensitive liquid 1 Rx, multi-component acrylic copolymer 5.0S/
Reaction product of diazo rebel and hexafluorophosphate α5v Oil Bruna 605 0.259 Methyl cellosolve
95.0g dimethylformamide
1αog (diazollll1- is a condensation of diazodiphenylamine and paraformaldehyde)
Tokushiwata negative PS version (11 and comparison P8 sales (2),
1- It was exposed to light using an ultra-high pressure water chain lamp at an intensity of 2.2 mW/- for 1 minute, and developed with the following developer at 25° C. for 50 seconds to obtain a lithographic printing plate.

Developer Kx, Phenyl Cellosolve 12II Benzotriazole Triethanolamine Addition Salt 61 Sodium Isopropyl Naphthalene Sulfonate. G!
In order to assess the storage stability of the paper, the negative PS plate (11) of the present invention and the comparative PS plate (2) were stored in an atmosphere of 11i75% at a temperature of 40°C, and the ones immediately after production were exposed to 1j4. Compared to the imaged one, when printing, the step tablet (1 (odd
Table 1 As is clear from Table 1, the negative type P8) &
(No. 11 is found to have excellent storage stability. Also, Fuga MP8 Sales (No. 11 was able to print more than 100,000 copies of printed materials with a brush.) 112 The water-insoluble material used in No. 11 Diazo resin, cyan all
2-Methoxy-4-hydroxy-7penzophenone-5-
Even if the reaction product 6ζ with sulfonic acid was changed, it was found that the storage stability and printing durability were significantly superior to Example 1.

% fraudulent applicant Fuji Pharmaceutical Industry Co., Ltd. (1 other person)

Claims (1)

[Claims] A polymer film of polyacrylic acid or polymethacrylic acid with a film thickness of α5 μ or less is formed on a positively oxidized aluminum plate, and a water-insoluble diazo resin and a military discipline general formula are formed thereon. (Engineering) 1 (. The structural unit shown by . and the following general formula (
n) 1 (In the above formulas I and 2, R1 represents a hydrogen atom or a methyl group, l(, represents a hydrogen atom or an alkyl group, and n is 1 to
A photosensitive lithographic printing plate comprising a photosensitive layer made of a polymer having an acid value of 10 to 1000 and containing a structural unit represented by (representing an integer of 10).