JP2538793B2 - Photosensitive lithographic printing plate developer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developer for a photosensitive lithographic printing plate containing an o-quinonediazide compound as a photosensitive component.

[Conventional technology]

It is known that an o-quinonediazide compound becomes a compound having a carboxyl group by the decomposition of a diazo group upon irradiation with actinic light. Therefore, when the photosensitive layer containing the o-quinonediazide compound is treated with an alkaline developing solution after image exposure, the exposed portion is removed and the unexposed portion becomes an image. It is extremely used as a photosensitive layer of a printing plate or a photoresist composition for etching. In particular, a composition obtained by mixing an o-quinonediazide compound with an alkali-soluble resin is advantageously used from the viewpoint of economy and practicality, and among them, a mixture of a novolac type phenol formaldehyde condensation resin or a cresol formaldehyde condensation resin is generally used. Has been. Sodium triphosphate is used as a developer for the automatic processor of these o-quinonediazide photosensitive layers,
A single or mixed aqueous solution of caustic soda, sodium silicate, potassium silicate, ammonium silicate or the like is used. However, caustic soda, sodium triphosphate aqueous solution, etc. are not suitable as a developing solution for a photosensitive lithographic printing plate using a metal support when the etching action on metals such as aluminum is strong and the developing time is long. Further, when the development result is extremely variable and extremely large, the image may be lost even if the development time is slightly exceeded. Further, the developing capacity is remarkably reduced due to repeated use, and the processable amount (processing capacity) of the photosensitive lithographic printing plate at a constant capacity is very small. Therefore, aqueous sodium silicate solution or aqueous potassium silicate solution has recently been used relatively advantageously. It has a weak etching effect on metals and, at the same time, contains silicon oxide (SiO ₂ ) which is a component of sodium silicate or potassium silicate and sodium oxide (Na ₂ O) or potassium oxide (K ₂ O) in a content ratio (generally SiO ₂ / Na ₂ O or the molar ratio of SiO ₂ / K ₂ O) and the concentration allow the developability to be adjusted to some extent. That is, as the SiO ₂ content increases, the developing power is suppressed and the development stability increases, and when the Na ₂ O or K ₂ O content increases, the developing power increases and the development stability decreases. The term “development stability” as used herein refers to the stability of development with respect to the development time, and when Na ₂ O or K ₂ O alone is increased, image loss easily occurs in a short time.

The higher the processing capacity at a constant volume, the better the Na ₂ O or K ₂ O content. Therefore, the developing power of the SiO ₂ / Na ₂ O ratio or SiO ₂ / K ₂ O ratio,
By increasing the total density while adjusting the development stability, it is possible to obtain a certain level of developing power and stability, as well as processing ability. However, there is a tendency that it is insufficient to satisfy any of the points, and lacks stability based on developing power, and lacks developing power and processing ability based on stability. Further, in a general automatic developing machine, a developing solution is supplied by a spray method to perform development, so that an alkali content is neutralized by carbon dioxide gas contained in the air, so that the processing ability is easily deteriorated. For this reason, since the concentration is relatively high, precipitates are easily generated, and there are drawbacks such that the amount of the acid for neutralization used in the treatment of the waste liquid after use is large. To summarize the problems of the developing solutions such as caustic soda, sodium triphosphate, sodium silicate, potassium silicate, etc., if the alkali strength is increased, the developing power and processing ability are excellent, but the developing stability is poor and the developing stability is low. In order to obtain it, the alkali concentration must be lowered and therefore the processing capacity will be lacking. Therefore, if the development stability can be obtained in a state where the alkali strength is high, it is possible to obtain a developing solution having excellent developing power and processing ability.

JP-A-50-51324 discloses a method of adding an anionic surfactant or an amphoteric surfactant to a developer as a method of obtaining development stability in a state of high alkali strength, and a method of adding a water-soluble cationic polymer. Is Japanese Patent Laid-Open No. 55-95946
JP-A-56-142528 describes a method of adding a water-soluble amphoteric polymer electrolyte. However, all of these developers have the drawback that they are foamed during development when they are developed using an automatic processor. In addition,
55-25100 discloses a periodic table II A, III A and III B.
It is described that an ionic compound of a transition element is added. In this case, there is an effect of suppressing the etching of the anodized aluminum support by a strong alkali, but the development stability was not sufficient.

[Problems to be Solved by the Invention]

Therefore, the object of the present invention is to improve the development stability over a long period of time,
It is an object of the present invention to provide a developer having excellent development processing ability and low foaming property, which is particularly suitable for use in an automatic processor.

Another object of the present invention is to provide a developing method using the above developing solution, which can provide a lithographic printing plate excellent in ink receptivity.

[Means for solving the problem]

The above-mentioned object is a water-soluble ethylene oxide addition obtained by adding 4 mol or more of ethylene oxide to an alkali metal silicate having a ratio of SiO ₂ / M ₂ O (M is an alkali metal) of 0.6 to 2.0 and an acid or alcohol. It was achieved by a developer of a photosensitive lithographic printing plate having an o-quinonediazide compound-containing photosensitive layer.

The alkali silicate used in the present invention includes sodium silicate, potassium silicate, and lithium silicate, which can be used alone or in combination. The SiO ₂ / M ₂ O molar ratio of alkali silicate (M represents an alkali metal) is preferably 0.6 to 2.0, particularly preferably 0.8 to 1.5. The above molar ratio is 2.0
If it exceeds, the developability tends to decrease. Further, as the above-mentioned molar ratio becomes smaller than 0.6, the alkali strength becomes higher, so that the harmful effect of etching a metal such as an aluminum plate generally used as a support of a photosensitive lithographic printing plate comes to appear. The concentration of alkali silicate in the developer is preferably 1 to 10% by weight, and particularly preferably 1.5 to 5% by weight. If it is higher than 10% by weight, precipitates and crystals are likely to be formed, and gelation is likely to occur during neutralization during the waste liquid, so that the waste liquid treatment liquid becomes troublesome. Also, 1% by weight
The lower the level, the lower the developing power and the processing capacity.

The water-soluble ethylene oxide addition compound used in the developing solution of the present invention is a compound obtained by addition-condensing an aliphatic or aromatic alcohol or hydroxy compound or acid with ethylene oxide, and a sulfonic acid or sulfonate group bonded thereto. Is a compound obtained by
When using an aliphatic alcohol, the carbon number of the alcohol is preferably 3 or more, more preferably 5 or more. Examples of alcohols include n-propyl alcohol and iso-
Propyl alcohol, n-butanol, isobutanol, secondary butanol, tertiary butanol, n-amyl alcohol, isoamyl alcohol, 3-pentanol, n
-Hexanol, methylamyl alcohol, 2-ethylbutanol, n-heptanol, n-octanol, 2
-Ethylhexanol, nonanol, n-decanol,
Undecanol, n-dodecanol, 3,5,5-trimethylhexanol, n-dodecanol, trimethylnonyl alcohol, tetradecanol, heptadecanol, cyclohexanol, benzyl alcohol, 2,6,8-trimethyl-4-nonanol, 2 -Methyl-7-ethyl-4
-Undecanol, 5-ethyl-2-nonanol, 3-
Ethyl-6-undecanol, 3,9-diethyl-6-undecanol, 3,9-diethyl-9-undecanol,
Examples include 3,9-diethyl-6-tridecanol, tridecanol, oleyl alcohol, lauryl alcohol, octyl alcohol, acetyl alcohol, trimethylene glycol, butanediol, 1,5-pentanediol, hexylene glycol, octylene glycol and glycerin. To be

Examples of aromatic hydroxy compounds include P-isobutylphenol, P-isohexylphenol, P-
Isooctylphenol, P-isododecylphenol, octylphenol, hexadecylphenol, alkyl (C _{6 to} C ₁₄ ) β-naphthol, dialkyl (C _{6 to} C
₁₄ ) Phenol, β-naphthol, P-phenylphenol and the like, and examples of the acid include valeric acid and
Caproic acid, enanthic acid, caprylic acid, pelargonic acid,
Examples thereof include capric acid, undecyl acid, lauric acid, tridecyl acid, myristic acid, pentadecyl acid, palmitic acid, margaric acid, stearic acid and the like.

If desired, block copolymerization of propylene oxide may be used for these compounds. Also,
The method of binding a sulfonate group to these compounds is described in, for example, JP-A-59-195641. These compounds, along with the novolac resin used in the photosensitive layer of the photosensitive lithographic printing plate, slowly adhere to the image area during the development process and slow the penetration of the developer into the development area to stabilize the development latitude. It is considered that the effect is shown. When the addition of ethylene oxide is less than 4 mol, the effect of stabilizing the development latitude is small. The preferred addition amount of ethylene oxide is from 6 to 50 mol. When it exceeds 50 mol, the developing speed becomes slow, or the ink adherence to the plate surface becomes poor during printing. Further, when 15 mol or more of ethylene oxide is added, foaming easily occurs in an automatic developing machine. In such a case, this problem can be solved by block cocondensing propylene oxide.

The addition amount of these water-soluble ethylene oxide adducts is suitably 0.003 to 10% by weight with respect to the developer, and the more preferable addition amount range is 0.05 to 5% by weight.

When the photosensitive layer has a narrow development latitude, a compound having a large addition mole number of ethylene oxide is used, and conversely, when the development latitude of the photosensitive layer is relatively wide but not sufficient, ethylene oxide is used. By using a compound having a small addition mole number, a developing solution having a desired development latitude can be obtained.

The developer of the present invention can maintain the development stability even in a developing method in which the temperature of the developer is raised to 28 to 40 ° C. in an automatic developing machine to enhance the developability.

The known compounds described below can be further added to the developer used in the present invention.

For example, neutral salts such as NaCl, KCl and KBr described in JP-A-58-75152, chelating agents such as EDTA and NTA described in JP-A-58-190952, and [Co described in JP-A-59-121336]. (NH ₃ ) ₆ ] C
Complexes such as l _3, etc., periodic table I described in JP-A-55-25100
Ionizable compounds of Group Ia, Group IIIa or Group IIIb elements, anions such as sodium alkylnaphthalene sulfonate described in JP-A-50-51324, N-tetradecyl-N, N-dihydroxyethylbetaine, or the like; Amphoteric surfactants, tetramethyldecynediol, etc. described in U.S. Pat. No. 4,374,920, nonionic surfactants described in JP-A-60-213943, methyl p-dimethylaminomethyl polystyrene described in JP-A-55-95946. Cationic polymers such as chloride quaternary compounds, amphoteric polymer electrolytes such as copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, and sodium sulfite described in JP-A-57-192952. Inorganic reducing salts such as
Alkali-soluble mercapto compounds or thioether compounds such as thiosalicylic acid, cystine and thiodiglycolic acid, inorganic lithium compounds such as lithium chloride described in JP-A-58-59444, and lithium benzoate described in JP-B-50-34442. Organic lithium compounds, organometallic surfactants containing Si, Ti, etc. described in JP-A-59-75255, JP-A-59-8424
Examples thereof include organic boron compounds described in No. 1, quaternary ammonium salts such as tetraalkylammonium oxide described in European Patent 101010, and bactericides such as sodium dehydroacetate described in Japanese Patent Application No. 61-298534.

Further, if necessary, an organic solvent having a water solubility of 10% by weight or less can be used in combination.

Carboxylic esters such as ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, butyl levulinate; ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone; Alcohols such as ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; methylene. There are halogenated hydrocarbons such as dichloride, ethylene dichloride and monochlorobenzene. One or more of these organic solvents may be used. Among these organic solvents, benzyl alcohol is particularly preferable.

The content in the developer is 5% by weight or less, preferably 1 to 4
% By weight.

In the development processing method using the developing solution of the present invention, it is advantageous to develop using an automatic developing machine, and it is preferable to perform deterioration of the developing solution by supplementing the development replenishing solution, that is, while compensating by a so-called replenishing method, A known technique is used as the replenishment method. For example, as described in JP-A-55-115039, a method of continuously or intermittently replenishing with a PS plate processing amount and time, and a dissolution rate of a photosensitive layer in the middle of a developing zone described in JP-A-58-95349. A method of providing a measuring sensor and replenishing according to the detected elution degree, Japanese Patent Application No. 62-178457
The method described in JP-A No. 63-4560 and Japanese Patent Application No. 63-4560 is preferably used, in which the impedance of the developer is measured and the detected impedance value is processed by computer to replenish it.

With the o-quinonediazide photosensitive layer to which the developing solution of the present invention is applied, alkali solubility is increased by irradiation with active light. A photosensitive copying layer containing an o-quinonediazide compound as a photosensitive component.

For such a light-sensitive material, see J. Coser, "Light-Sensitive Systems" (John WiIey & Sons, Inc.).
Or "Photosensitive Resin Data Collection" (edited by Sogo Chemical Research Institute)
Etc. are described in detail. In particular, a mixture of an o-quinonediazide sulfonic acid ester of an aromatic polyhydroxy compound and an alkali-soluble resin such as a phenol resin, a cresol resin, a styrene / maleic anhydride copolymer is commonly used, and is commonly used as a lithographic printing photosensitive material. It is used for plates (presensitized plates) and photo-etching resists. Among these, the developer of the present invention is o
-Particularly excellent as a developer for a positive photosensitive printing plate having a quinonediazide photosensitive layer (hereinafter, referred to as a positive PS plate). Such a positive PS plate basically has a photosensitive layer made of an o-quinonediazide compound on an aluminum plate as a support. Suitable aluminum plates include pure aluminum plates and aluminum alloy plates, as well as aluminum laminated or vapor deposited plastic films. The surface of the aluminum plate is preferably subjected to graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like, or anodization treatment. Further, as described in U.S. Pat.No. 2,714,066 after graining, an aluminum plate immersed in an aqueous solution of sodium silicate, and an aluminum plate as an anode as described in JP-B-47-5125 are used. A product obtained by immersing it in an aqueous solution of an alkali metal silicate after the oxidation treatment is also suitably used. The above-mentioned anodizing treatment is, for example, electrolysis of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, boric acid or the like, an organic acid such as oxalic acid, sulfamic acid or the like, or an aqueous solution or a non-aqueous solution of these salts, or a combination of two or more kinds. It is carried out by passing an electric current in a liquid using an aluminum plate as an anode.

Further, silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective.

Further, U.S. Pat.No. 4,087,341, JP-B-46-274.
No. 81 and Japanese Patent Application Laid-Open No. 52-30503 are also useful, as described above. In addition, U.S. Pat.
Also preferred are aluminum plates which are grained, chemically etched and then anodized, as described in US Pat. No. 998. These hydrophilization treatments, in addition to the treatment for imparting hydrophilicity to the surface of the support, prevent harmful reaction with the photosensitive composition provided thereon, and further improve adhesion to the photosensitive layer. It is applied for various purposes such as to improve

Further, U.S. Pat.No. 3511661, JP-B-57-16349, JP-B-46-35685, JP-A-60-149491, JP-A-60-23299.
A method of applying an undercoating agent as described in No. 8 etc. is also preferable.

The photosensitive layer provided on the hydrophilic surface of the support comprises an o-quinonediazide compound. Particularly preferred o-quinonediazide compounds are o-naphthoquinonediazide compounds, such as U.S. Pat. Nos. 3,046,110, 3,046,111,
No. 3,046,112, No. 3,046,115, No. 3,046,118
No. 3,046,119, No. 3,046,120, No. 3,046,12
No. 1, No. 3,046,122, No. 3,046,123, No. 3,061,4
No. 30, No. 3,102,809, No. 3,106,465, No. 3,635,
It is described in a number of publications, including the specifications of Nos. 709 and 3,647,443, and these can be suitably used. Among these, particularly o-naphthoquinodiazide sulfonic acid ester of aromatic hydroxy compound or o-
Naphthoquinone diazide carboxylic acid ester, and o-naphthoquinone diazide sulfonic acid amide or o-naphthoquinone diazide carboxylic acid amide of an aromatic amino compound are preferable, and in particular, a condensate of pyrogallol and acetone described in US Pat. No. 3,635,709. Ester-reacted with o-naphthoquinone diazide sulfonic acid, ester having o-naphthoquinone diazide carboxylic acid or o-naphthoquinone diazide carboxylic acid on a polyester having a hydroxy group at the terminal described in US Pat. No. 4,028,111 Reacted, British Patent No. 1,
Esterification of o-naphthoquinonediazide carboxylic acid or o-naphthoquinonediazide carboxylic acid with homopolymers of p-hydroxystyrene or copolymers thereof with other copolymerizable monomers as described in US Pat. No. 494,043. A copolymer of o-aminostyrene and another copolymerizable monomer as described in U.S. Pat. No. 3,759,711 with o-quinone diazide sulfonic acid or o-quinone diazide carboxylic acid as an amide. The ones that have reacted are very good.

These o-quinonediazide compounds can be used alone, but it is preferable to mix them with an alkali-soluble resin and provide this mixture as a photosensitive layer. Suitable alkali-soluble resins include novolac type phenolic resins, specifically phenol formaldehyde resins,
o-Cresol formaldehyde resin, m-cresol formaldehyde resin and the like are included. JP-A-50-
As described in JP-A-125806, a condensate of phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms, such as t-butylphenol formaldehyde resin, and a condensate of formaldehyde are used together with the phenol resin described above. Then, it is even more preferable. The alkali-soluble resin is contained in the photosensitive layer in an amount of about 50 to 85% by weight, more preferably 60 to 85% by weight.
80% by weight is included.

Further, an alkali-soluble resin other than the above-mentioned alkali-soluble novolac resin can be blended in the composition of the present invention as required. For example, styrene-acrylic acid copolymer, methylmethacrylate-methacrylic acid copolymer, alkali-soluble polyurethane resin, JP-B-52-28
The alkali-soluble vinyl-based resin and the alkali-soluble polybutyral resin described in JP-A-401 may also be contained.

If necessary, the photosensitive layer comprising the o-quinonediazide compound may further contain additives such as dyes, plasticizers, and components for imparting printout performance as described in JP-A-58-203433. .

The coating amount of the photosensitive layer consisting of o- Kinojiajido compound provided on the support is from about 0.5 to about 7 g / m ^2, more preferably from 1.5~3g / m ^2.

When the positive PS plate thus obtained is exposed through a transparent original image by a light beam rich in active light rays such as a carbon arc lamp, a mercury lamp, a metal halide lamp, a xenon lamp, and a tungsten lamp, the portion becomes alkali-soluble. Therefore, when treated with the developing solution of the present invention, the exposed portions of the photosensitive layer are eluted, and the hydrophilic surface of the support is exposed.

〔The invention's effect〕

The developer of the present invention has high development stability, management of development conditions is extremely easy, and high processing capacity allows development of many photosensitive materials in a small amount, and further, discharge of used waste liquid is small, and waste liquid treatment is possible. Is also easy. Further, high temperature development can be stably performed.

〔Example〕

 The present invention will be described in detail below with reference to examples.

Examples 1 to 6 JP-B-43-28403 Japanese Unexamined Patent Publication No. 43-28403 0.8 parts by weight of naphthoquinone-1,2-diazide-5-sulfonate of polyhydroxyphenyl obtained by condensation of acetone and pyrogallol described in Example 1 and novolak -Type metapara mixed cresol formaldehyde resin 2.2 parts by weight, novolac type octylphenol formaldehyde resin 0.02 parts by weight, phthalic anhydride 0.08 parts by weight, 2-trichloromethyl-5- (p-methoxystyryl) -1,3-4-oxazoazole 0.04 parts by weight Further, 0.03 parts by weight of para-toluenesulfonate of crystal violet was dissolved in 20 parts by weight of methyl cellosolve acetate and 8 parts by weight of methyl ethyl ketone to prepare a photosensitive solution. A 0.3 mm thick aluminum plate grained with a nylon brush is etched with alkali, and then electrolytically etched in a nitric acid aqueous solution, and then anodized in a sulfuric acid aqueous solution (anodized film amount 2.7 g / m 2.
² ) After that, it was treated with an aqueous solution of zinc acetate at 70 ° C, washed thoroughly, dried, and then the above photosensitive solution was applied and dried by a spin coater to obtain a photosensitive plate having a photosensitive layer of about 2.0 g / m ^2. It was This photosensitive plate was exposed using a PS light (2kw metal halide lamp) manufactured by Fuji Photo Film Co., Ltd. through a step wedge having a density difference of 0.15 and a halftone dot wedge. On the other hand, as a developing solution, a developing solution was prepared by adding the compounds shown in Table 1 to a 2 wt% aqueous solution of sodium silicate 1 having a SiO ₂ / Na ₂ O molar ratio of about 0.9.

The exposure-printed photosensitive plate was dipped in each developing solution maintained at a developing solution temperature of 25 ° C and 35 ° C.
After a minute, it was taken out and washed with water. Table 2 shows the reproducibility of the number of step wedges exuded and the halftone dots in the highlight portion of the halftone dot wedge.

It can be seen from Table 2 that the developing solutions of Examples 1 to 6 are much more stable in temperature, time, etc. than the aqueous solution of sodium silicate of Comparative Example 1 alone. Further, the development processing capacities of the developing solutions of Examples 1 and 2 were examined.
Even after developing the photosensitive plate of ^3, the developing ability was sufficiently maintained. Further, in Examples 1 to 6, potassium silicate was used instead of sodium silicate to maintain the same performance as sodium silicate.

Claims (1)

(57) [Claims] 1. A silicic acid alkali metal salt having a ratio of SiO ₂ / M ₂ O (M represents an alkali metal) of 0.6 to 2.0, and an alkali (C _{6 to} C
₁₄ ) β-naphthol or a water-soluble ethylene oxide addition compound obtained by adding 4 mol or more of ethylene oxide to β-naphthol, or a water-soluble ethylene oxide addition compound represented by the following formula,
A developer for a photosensitive lithographic printing plate having a photosensitive layer containing an o-quinonediazide compound.