JPH028847A - Damping-waterless planographic printing plate - Google Patents

Abstract

PURPOSE:To prevent the flawing of a non-printing part and to improve printing resistance without adversely affecting the ink repulsive property of a silicone rubber layer by incorporating a graft polymer having organosiloxane in branches into the silicone rubber layer. CONSTITUTION:The graft polymer having the organosiloxane in the branches is incorporated into the silicone rubber layer of the printing plate material having a photosensitive layer and the silicone rubber layer successively on a base. The base which has the flexibility to allow setting of the base to an ordinary planographic printing machine and withstands the load to be exerted at the time of printing is preferable as the base. The more preferable base is an aluminum sheet. The photosensitive material used for the photosensitive layer is not particularly limited and is preferably a positive type photosensitive material of a quinone diazide type like o-naphthoquinone diazide compd. The graft polymer obtd. by a method of radical copolymn. of acryl-modified silicone and monomer is preferable as this polymer has excellent solubility in an org. solvent. The flawing of the non-imaging part is improved and the printing resistance is improved in this way without adversely affecting the ink repulsive property.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a lithographic printing plate material that does not require dampening water, and more particularly to a lithographic printing plate material that does not require dampening water and is resistant to scratches in non-image areas. [Prior Art] Conventionally, as a lithographic printing plate material that does not require dampening water (hereinafter referred to as "plate material" as necessary), one in which a photosensitive layer and a silicone rubber layer are sequentially coated on a support is known. . If you use a lithographic printing plate that does not require dampening water (hereinafter referred to as a "printing plate" as necessary) obtained by exposing and developing this plate material, the ink repellency of the photosensitive layer and the ink repellency of the silicone rubber layer will allow printed matter to be printed. can be obtained. However, in such printing plates, it is difficult to obtain sufficient attractive force between the photosensitive layer and the silicone rubber layer, and it is difficult to obtain a sufficient attractive force between the photosensitive layer and the silicone rubber layer. Problems such as easy scratching on the ii line portion and poor dot image reproducibility occurred. In order to improve this, Japanese Patent Application Laid-Open No. 82-288849 proposes a technique of adding a certain silane compound to the silicone rubber layer. [Problems to be Solved by the Invention] However, according to Japanese Patent Application Laid-open No. 82-288849, although it is true that the scratch resistance of the non-printing area is improved, the silicone rubber layer must be durable. This had an adverse effect on ink repellency, and as a result, there was a problem with one printing durability. [Objective of the Invention] Therefore, the object of the present invention is to prevent scratches in non-image areas without adversely affecting the ink repellency of the silicone rubber layer;
1111 An object of the present invention is to provide a lithographic printing plate material that does not require dampening water and can improve printing properties. [Means for Solving the Problems] The inventor of the present invention has conducted intensive studies to achieve the above object, and as a result, has arrived at the present invention. Namely, 1. A lithographic printing plate material that does not require dampening water according to the present invention is a lithographic printing plate material that does not require dampening water and has a photosensitive layer and a silicone rubber layer in this order on a support. The silicone rubber layer is characterized in that it contains a graft polymer having polyorganosiloxane as a branch. [Function] Conventionally, polyorganosiloxane alone has not been able to prevent scratches in non-image areas and improve rigidity without adversely affecting the ink repellency of the silicone rubber layer. According to the invention, since the silicone rubber layer contains a unique graft polymer having polyorganosiloxane as a branch, it prevents scratches in non-image areas without adversely affecting the ink repellency of the silicone rubber layer. I was able to improve my rationality. LSpecific Structure of the Invention] The support of the present invention is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can withstand the load applied during printing, such as aluminum, zinc, copper,
Metal plates such as steel, and chrome. Examples include a metal plate plated or vapor-deposited with zinc, copper, nickel, aluminum, iron, etc., a plastic film and glass plate, resin coated paper, paper covered with metal foil such as aluminum, and the like. Among these, aluminum plates are preferred. The treatment for the support itself to improve the adhesion is not particularly limited, and includes various surface roughening treatments. A primer layer may be provided on the support, and the primer layer is preferably a resin or a silane coupling material,
As the resin, for example, polyester resin, vinyl chloride
Vinyl acetate copolymer, acrylic resin, vinyl chloride resin,
Examples include polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin, polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, and the like. Among them, epoxy resin is preferred. In addition, as the anchor agent constituting the primer layer, 1
For example, the silane coupling agent and silicone primer used in the silicone rubber layer described above can be used, and organic titanates and the like are also effective. The photosensitive material used in the photosensitive layer of the present invention is not particularly limited, and examples thereof include quinonediazide-type positive photosensitive materials such as conventionally known 0-naphthoquinonediazide compounds. Suitable 0-naphthoquinone diazide compounds include naphthoquinone-(1,2)-diazide-(2)-sulfonic acid chloride and phenol or cresol-formaldehyde resins described in U.S. Pat. No. 3,048,120. There is an ester with. Other useful O-naphthoquinonediazide compounds include esters of pyrogallol-acetone resin and O-naphthoquinonediazide sulfonic acid chloride described in U.S. Pat. No. 3,835,709, JP-A-55-78348;
Ester of polyhydroxyphenyl resin and 0-naphthoquinonediazide sulfonic acid chloride described in No. 5B-1044 and No. 5B-1045, JP-A-50
A homopolymer of p-hydroxystyrene or a copolymer of this with other copolymerizable monomers as described in Japanese Patent Publication No. 113305, ester-reacted with 0-naphthoquinonediazide sulfonic acid chloride. -17481, a reaction product of a polymer product of a styrene monomer and a phenol derivative and O-quinonediazide sulfonic acid, and an ester of polyhydroxybenzophenone and O-naphthoquinonediazide sulfonic acid chloride. A photosensitive composition containing such a quinone diazide type positive photosensitive material may optionally contain a binder. For example, a preferred example is a novolac resin soluble in an aqueous alkali solution. Examples of such novolac resins include phenol-formaldehyde resins,
cretu-formaldehy)/resin, p-tart-
Typical examples include butylphenol-formaldehyde resin and phenol-modified xylene resin.
Ru. The amount of quinonediazide compound in the photosensitive layer is 10 to 50
gLHk%, more preferably 20 to 40% by weight
It is. Further, the amount of the above-mentioned binder added is 4% in the photosensitive layer composition.
It is 5 to 80% by weight, preferably 50 to 70% by weight. Further, in the present invention, the following photosensitive substances can be used. For example, a diane resin typified by a condensate of an aromatic diazonium salt and formaldehyde. Particular preference is given to salts of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde, such as reaction products of hexafluorophosphates, tetrafluoroborates, perchlorates or periodates with said condensates. Certain diane resin inorganic salts and U.S. Patent No. 3,300,30
Examples include diazo resin organic salts, which are reaction products of the condensate and sulfonic acids, as described in No. 9. Furthermore, diazo resins are preferably used together with binders. Various polymeric compounds can be used as such a binder, but monomers having an aromatic hydroxyl group such as those described in JP-A No. 54-98813, such as N-(4-hydroxyphenyl ) acrylamide,
N-(4-hydroxyphenyl)methacrylamide,
o-, m-1 or p-hydroxystyrene, o-, m
Copolymer of -1 or p-hydroxyphenyl methacrylate and other monomers, US Pat. No. 4,123,276
Polymers containing hydroxyenal acrylate units or hydroxyethyl methacrylate units as the main turning unit, natural resins such as shellac and rosin, polyvinyl alcohol, and U.S. Pat.
, 751,257,
Included are linear polyurethane resins described in U.S. Pat. No. 3,860,097, polyvinyl alcohol phthalate resins, epoxy resins condensed from bisphenol A and epichlorohydrin, celluloses such as cellulose acetate and cellulose acetate phthalate. . Also, as a photosensitive group in the main chain or side chain of the polymer, C) I=C:
Photosensitive polymers such as polyesters containing H-C knee, polyamides, and polycarbonates. Examples include those containing gold as a main component. For example, phenylene diethyl as described in JP-A-55-40415. Photosensitive polyesters obtained by condensation of acrylates with hydrogenated bisphenol A and triethylene glycol, as described in U.S. Pat. No. 2,958,878;
Examples include photosensitive polyesters derived from (2-properidene)malonic acid compounds such as cinnamylidenemalonic acid and difunctional glycols. Further examples include aromatic acid compounds in which the acid group is bonded directly or via a carbonyl group or a sulfonyl group to an aromatic ring. -Ashi) Hensiato, polyvinyl-p-Ashitohenzaar, as described in Special Publication No. 1977-9613.
- Reaction product of arylsulfanyl clot 1~ and unperturbed hydrocarbon polymer, and Japanese Patent Publication No. 4:1-210
Examples include polymers having sulfonylacyl l- or carbonyl acid, as described in No. 57, No. 44-229, No. 44-22954, and No. 45-249+5. Furthermore, a photopolymerizable composition comprising an addition polymerizable unsaturated compound may also be mentioned. The photopolymerizable polymers used in this composition include ethylene glycol mono(cy)(meth)acrylate 1 to
Polyethylene glycol mono(cy)(meth)acrylate, hydroxyethyl(meth)acrylate, and 1-roxypropyl(meth)acrylate, chrycidyl(meth)acrylate, hydroxyphenylamino(meth)acrylate, l-chloro-2-hydroxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, a series of hydrophilic monoacrylic esters, methaxolic ester ethylene bisacrylamide,
Acrylamide derivatives such as N-methylol acrylamide and methoxymethyl acrylamide, allyl alcohol esters such as triacryl cyanurate, triacryl phosphate, diallyl phthalate and sialyl simalate, other styrene derivatives, cinnabar M and J conductors, etc. You can use it. Examples of the photosensitizer used in this composition include benzphenone derivatives, benzoin derivatives, anthraquinone derivatives, aldehydes, ketones, sulfur compounds, halogen compounds, and dyes such as methylene true and riboflavin. The present invention can also be applied to photosensitive compositions used in electrophotographic printing plates.
Examples include a photosensitive composition comprising an electron donating compound, a phthalocyanine pigment, and a phenol resin, which are used in a printing original plate using electrophotography as described in No. 0. In addition to the above, the photosensitive layer contains dyes (for example, Victoria Pure Fluor BO) I (manufactured by Hodogaya Chemical Co., Ltd.) and Oil Blue 1160 to make the image visible after exposure or development.
3 (Triphenylmethane-based and diphenylmethane-based dyes such as (manufactured by Orient Kagaku Kogyo Co., Ltd.)), alkyl ethers (e.g., ethyl cellulose, methyl cellulose) to improve coating properties, fluorine-based surfactants, nonionic surfactants (For example, Pluronic L64 (manufactured by Asahi Denka Co., Ltd.), a potting agent for imparting flexibility to the coating film (for example,
(polyethylene glycol, tricresyl phosphate, acrylic acid or methacrylic acid polymers), stabilizers (eg phosphoric acid, oxalic acid, tartaric acid, etc.). The silicone rubber layer of the present invention contains a graft polymer having polyorganosiloxane as a branch (hereinafter referred to as the graft polymer of the present invention). As the graft polymer of the present invention, for example, those obtained by the following synthesis method are used. (1) As seen in Japanese Patent Publications Nos. 32-6896, 47-16199, and 48-28389, activation is achieved by abstracting hydrogen from the lower alkyl group bonded to the silicon atom of silicone. [2] As seen in Japanese Patent Publication No. 46-9355, a silicone having an active group and a living polymer obtained by anionic polymerization are used. Method for obtaining a silicone-based craft polymer by reaction (3) Synthesizing a polysiloxane polyester containing maleic acid in the main chain, as shown in Japanese Patent Publication No. 52-135391, and adding maleic acid and a charge transfer complex to this polysiloxane polyester. Method for obtaining a silicone-based graft bomber by mixing and graft polymerizing electron donor molecules that are easy to generate (4) α, ω-dihydroxydimethylbolysiloxane 1
A method of obtaining a silicone-based graft polymer by radical copolymerization of an acrylic-modified silicone obtained by a condensation reaction from 0.25 to 1 mole of γ-methacryloxypropylmethyldichlorosilane per mole and a radical-polymerized sulfuric acid (hereinafter referred to as acrylic-modified silicone). Of the above methods, silicone-based craft polymers obtained by the radical copolymerization method of acrylic-modified silicone and monomers have excellent solubility in organic solvents. The silicone content in the kraft polymer of the present invention is from 10 to 95% by weight, preferably 2% by weight in the graft polymer.
0 to 90% by weight (herein, the silicone content in the graft polymer is an analytical value obtained by firing a silicone-based craft polymer and assuming that the silicone is SiO□). When the graft polymer of the present invention having a silicone content of less than 10% by weight is used in a coating composition, the surface modification effect of the coating film obtained cannot be sufficiently exhibited; When the graft polymer of the invention is used in a coating composition, it has poor solubility in organic solvents. The silicone-based graft polymer obtained in this way is a craft copolymer with a copolymer obtained from a radically polymerizable monomer as the trunk and silicone as branches, and the number of branch points is determined by the acrylic resin used. This can be determined by the molecular weight of the modified silicone, the molecular weight of the radically weighted monomer, the molecular weight of the silicone-based graft copolymer, and the silicone content in the silicone-based graft copolymer. The graft polymer of the present invention may have a monomer capable of co-merging with the backbone or a polymer other than organopolysiloxane. The amount of the graft polymer used in the present invention is 0.01 to 100% by weight, preferably 0.1 to 90% by weight, in the silicone rubber layer composition. If the amount of graft bomber added is less than 0.01% by weight, the strength of the silicone rubber layer will not be sufficient. The graft polymer may be added by any method, such as adding the graft polymer directly to the organic solvent, or dissolving the graft polymer in an appropriate solvent and adding the resulting solution to the organic solvent. Examples of the organic solvent used include those used in the developer described below. In the present invention, in addition to the above-mentioned components, a small amount of a photosensitizer may be included in the silicone rubber layer. The thickness of each layer constituting the plate material of the present invention is as follows. That is, the support body is 50 to 4004 m, preferably 100 m
~:lOOgu+, photosensitive layer is 0.05~lOpLm
, preferably 0.5 to 5 pLI11. The silicone rubber layer has a thickness of 0.5 to 10 gm, preferably 1 to 40 wells. In the present invention, a protective layer may be provided on the upper surface of the silicone rubber layer, if necessary. The dampening water-free plate material of the present invention is manufactured, for example, as follows. 1. A composition solution to form a photosensitive layer is coated on the support using a conventional coater such as a reverse roll coater, an air knife coater, a Meyer coater, or a rotary coater such as a Whaler, and then dried and thermally cured if necessary. do. If necessary, a primer layer may be provided between the support and the photosensitive layer in the same manner as for the photosensitive layer. Next, a silicone rubber solution is applied onto the photosensitive layer in the same manner and heat-treated at a temperature of usually 100 DEG to 120 DEG C. for several minutes to sufficiently cure the solution to form a silicone rubber layer. If necessary, a protective film can be provided on the silicone rubber layer using a laminator or the like. Next, a method for manufacturing a printing plate that does not require dampening water using the plate material that does not require dampening water of the present invention will be explained. A negative film, which is a manuscript, is vacuum attached to the surface of a negative plate material and exposed. As a light source for this exposure, a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, etc., which generate abundant ultraviolet light, are used. Next, the negative film is peeled off and developed using a developer. As the developer, any one known as a developer for plate materials that do not require dampening water can be used. For example, aliphatic hydrocarbons (hexane, heptane, ° "Isopar E, H, G" (trade name of aliphatic hydrocarbon mantle made by Etsuji Chemical), gasoline, kerosene, etc.)
, aromatic hydrocarbons (toluene, xylene, etc.), or halogenated hydrocarbons (1 to ricrene, etc.) to which the following polar solvents are added. Alcohols (methanol, ethanol, water, etc.), ethers (methyl cellosolve, ethyl cellosol, phthyl cellosol, methyl carpitol, ethyl carpitol, sotyl carbitol thioxane), ketones (acetone, methyl ethyl ketone, etc.), esters ( (ethyl acetate, methyl cellosolve acetate, cellosolve acetate, carpitol acetate, etc.) It is also possible to dye the image area at the same time as development by adding dyes such as crystal violet and astrazone red 1 to the developer. Development can be carried out by a known method, such as using a developing vat containing the above-mentioned developer, or pouring the developer onto the printing plate and then rubbing it with a developing brush. By the above development, the silicone rubber in the exposed areas is removed and the photosensitive layer is exposed, and the unexposed areas are left with either the silicone rubber layer or the remaining printing plate. Note that a printing plate can also be obtained by exposing a positive film, which is an original, to a positive plate material. [Effects of the Invention] According to the present invention, a dampening water-free lithographic plate can prevent scratches in non-image areas and improve layer properties without adversely affecting the ink repellency of the silicone rubber layer. We can provide printing plate materials. [Example] The present invention will be explained in more detail with reference to Examples below. In the following description, "r parts" means "parts by weight" unless otherwise specified. Synthesis example 1 α,ω-dihydroxydimethylpolysiloxane 220g
γ
-methacryloxypropylmethyldichlorosilane 12
．． 0.06 g (0.05 mol) of a 10% diethyl ether solution was gradually added dropwise at room temperature over 1 hour. The reaction proceeded immediately and white crystals of pyridine hydrochloride were precipitated. After the dropwise addition was completed, the mixture was further stirred at room temperature for 1 hour, and the crystals of pyridine hydrochloride were removed by filtration. Next, this solution was placed in a separatory funnel, and 500+oM water was added thereto, thoroughly shaken, and washed with water. After washing with water, the separatory funnel was left standing to separate the upper ether layer and the lower aqueous layer. Anhydrous sodium sulfate was added to the obtained ether layer, and the mixture was left at room temperature overnight to dehydrate. Thereafter, anhydrous sodium sulfate was removed by filtration, and the resulting filtrate was distilled under reduced pressure to remove ether, yielding 225 g of a colorless and transparent acrylic-modified silicone. Next, the obtained acrylic modified silicone was polymerized. For polymerization, 100 parts of the acrylic modified silicone, 1.0 part of azopisisophthyronitrile, and 300 parts of toluene were placed in a flask equipped with a condenser and a stirrer, and the mixture was heated for 80 min in a nitrogen atmosphere.
The reaction was carried out for 24 hours at a temperature of .degree. After the reaction, the toluene was concentrated to 1/10 by distillation under reduced pressure to obtain a large amount of l1exane:2-P.
It was dropped into rOH (Propertool) = 1:1. After thorough stirring, the supernatant was poured off to extract unreacted acrylic-modified silicone and dried under reduced pressure, yielding 80 parts of a sticky substance. This silicone-based tarraft polymer was soluble in toluene, xylene, and thinner. Further, the number average molecular weight in terms of polystyrene was 50,000. The molecular weight is a value determined by liquid chromatography. Synthesis Example 2 100 parts of α,ω-cyhydroxydimethylborisiloxane C■2, 83 parts of styrene, 67 parts of butyl acrylate, and 0.75 parts of di-t-phthyl peroxide were placed in a flask equipped with a condenser and a stirrer. The reaction was carried out at a temperature of 122° C. for 7 hours in a nitrogen atmosphere. A small amount of unreacted monomer was removed at 80° C. under a vacuum of 1+a+st1 g. The reaction product was a white highly viscous oil. Even when the reaction product was attempted to be dissolved in toluene, xylene, and thinner, there were some undissolved substances, resulting in a cloudy solution. Example I A phenol formaldehyde resol resin (Sumilite Resin PC-1) manufactured by Sumitomo Dures was placed on a smooth aluminum plate degreased in a conventional manner by dry weight.1. It was coated so as to give Opm and cured by heating at 200'C for 3 minutes. The following photosensitive composition was coated on the primer layer at a dry weight of 2 g/m' and finned at 120°C for 35 seconds.
It was dried to form a photosensitive layer. Fork Jj

[Consideration]

(1)! Partial esterification product of phenol formaldehyde novolac resin with average degree of polymerization of 5.6 and naphthoquinone-1,2-diazide-5-sulfonic acid chloride (esterification rate 49%) 100 parts by weight (2) 4.4-diphenylmethane diisocyanate 3
0 parts by weight (3) 0.2 parts by weight of cyphtyltin diacetate Next,
2. Apply the following silicone rubber layer composition on the photosensitive layer by dry weight. The silicone rubber layer was coated to obtain a silicone rubber layer. 10 parts by weight = 85/15 ff11 ratio) 100 parts by weight (3) Shisotyltin diacetate o, former parts by weight A thickness of 10 parts by weight was applied to the surface of the silicone rubber layer obtained as above.
A lithographic printing plate material requiring no dampening water was obtained by laminating a μm polypropylene film. A negative film was applied to this plate material, and the film was vacuum-adhered and exposed for 00 seconds using Idolfin 2000 manufactured by Iwasaki Tonkeisha. Next, the laminate film was peeled off, and a developer consisting of 90 parts by weight of Isopar H (manufactured by Esso Chemical Co., Ltd.), 3 parts by weight of diethylene glycol monoethyl ether, 3 parts by weight of diethylene glycol monoethyl ether, and 5 parts by weight of diethyl succinate was added. When the developer was soaked in a developing vat and lightly rubbed on the plate surface, the silicone rubber layer in the exposed areas was removed and the photosensitive layer was exposed. In this way, the image of the negative film was faithfully reproduced over the entire surface of the printing plate. The scratch prevention performance of this printing plate was evaluated using the following test method. [Scratch test method] Continuous weighted scratch strength test @ (TYPE-HE I
DON-18), a sapphire needle of about 0.5 mm was scanned at a speed of 60 cm/min, and the non-image area of the printing plate was immersed in the organic solvent Isopar E manufactured by Esso, while being continuously applied. hurt. This involves printing on a scratched printing plate using a flatbed proofing machine that does not use dampening water, and then measuring the load on the areas that are receptive to ink. This means that a printing plate with a large load, which causes ink adhesion due to scratches, has excellent scratch prevention performance. The results are shown in Table 1. Next, the above printing plate was attached to a Heidelberg GTO printing machine with the dampening water supply device removed, and TO
A printed matter was obtained by printing on YO with ING ULTRA TUK AQUALES G red ink. The printing durability of this printed matter was evaluated based on the number of printed matter that was free of stains and had good reproducibility of highlight areas. The results are shown in Table 1. Example 2 After forming a primer layer in the same manner as in Example 1, the following photosensitive composition was applied to give a dry weight of 5 g/d.
A photosensitive layer was formed by drying at Q''C. Photosensitive composition (1) Acrylic acid/methyl methacrylate copolymer (copolymerization ratio 7:3) 60 parts by weight IO parts by weight Non-(5) N-methyl acrylate 1-(6) Dye obtained by reacting crystal violet with acid 5 parts by weight 3 parts by weight violet 4g 0.5 parts by weight A polypropylene film with a thickness of 10 μm was laminated on the surface. A positive film was applied to this plate material, vacuum-adhered, and exposed for 35 seconds using Idol Fin 2000 manufactured by Iwasaki Electric Co., Ltd. Next, the same as in the example process When developed, a plate that faithfully reproduced the positive film was obtained. This was evaluated in the same manner as in Example 1. Comparative Example l In Example 1, the silicone rubber layer composition was replaced with the following composition (JP-A-62 Plate materials and printing plates were obtained in the same manner except that they were changed as in No. -2888119), and the scratch prevention performance and printing durability were evaluated.The results are shown in Table 1. (3) Dibutyltin diacetate 0. 01 parts by weight (4
) Cll:+01il+ CHz+ 33! (OCzH
s): lo, s fffffi part Table 1 As is clear from Table 1, the present invention shows no significant difference in scratch prevention performance compared to the comparative example, but it is found to be very superior in printing durability. Note that the effects of the present invention were confirmed even when the kraft polymer of the present invention was replaced with other compounds disclosed in this specification.

Claims (1)

[Claims] A dampening water-free lithographic printing plate material having a photosensitive layer and a silicone rubber layer in this order on a support, wherein the silicone rubber layer contains a graft polymer having polyorganosiloxane as a branch. Lithographic printing plate material.