JPH117123A - Waterless photosensitive lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a waterless photosensitive lithographic printing plate for direct print having excellent thermal stability which enables direct print making from digital data by using a solid laser or a semiconductor laser (heat mode) having the emission region from near infrared to infrared. SOLUTION: This printing plate is produced by successively forming a photosensitive layer and a silicone rubber layer on a supporting body. The photosensitive layer contains (a) at least one crosslinking compd. selected from (a-1) aromatic compds. with substitution of alkoxymethyl groups or hydroxymethyl groups, (a-2) compds. having N-hydroxymethyl groups, N-alkoxymethyl groups, or N-acryloxymethyl groups, (a-3) an epoxy resin, and (b) an alkali soluble binder, (c) an IR absorbent, and (d) a compd. which produces acid by heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate requiring no fountain solution and capable of printing without using a fountain solution, and more particularly to a fountain solution for direct plate making that can be directly drawn from digital signals from a computer or the like. Unnecessary photosensitive lithographic printing plate.

[0002]

2. Description of the Related Art In recent years, lasers have been remarkably developed. In particular, high-power and small-sized solid-state lasers and semiconductor lasers having a light-emitting region from near infrared to infrared have become easily available. These lasers are very useful as an exposure light source when making a plate directly from digital data of a computer or the like.

Conventionally, as a lithographic printing plate having high sensitivity and requiring no dampening solution that can be directly drawn from digital data of a computer, Japanese Patent Publication No. 57-3516 and Japanese Patent Application Laid-Open No. 53-55211 disclose an ink repellent layer made of a silicone resin. above,
A printing plate in which an image portion is formed by forming a toner image using electrophotography is disclosed. JP-A-54-44905 discloses a printing plate in which a silver salt emulsion layer is laminated and which can be exposed to light with a wide range of wavelengths with high sensitivity. Further, U.S. Pat. No. 4,958,562 discloses a printing plate of a type in which a silicone rubber layer is laminated on a substrate and an image portion is formed by discharge breakdown.

Further, when digital data of a computer is directly made by a laser beam, a negative type is advantageous because a positive type material requires a considerable writing time.
As a negative type photosensitive lithographic printing plate requiring no dampening solution,
No. 1-54222 and JP-B-61-616 propose a photosensitive lithographic printing plate requiring no dampening solution in which a silicone rubber layer is provided on a photolytic photosensitive layer comprising O-naphthoquinonediazide backed by a support. Have been. Also, Japanese Patent Laid-Open No. 59-1
No. 7552 and Japanese Patent Publication No. 3-56223 propose that a similar printing plate is used for both a positive type and a negative type by adjusting the processing method.

[0005] Recently, as a negative type lithographic printing plate requiring no fountain solution, a compound capable of generating an acid by light in a photosensitive layer (a photoacid generator) and a compound which undergoes hydrolysis or the like by an acid to change the solubility, A composition containing a binder resin and the like as necessary has been reported. For example, JP-A-63-
No. 88556 discloses that a silicone is provided on a support via a photoacid generator, a photosensitive layer containing a compound having a C—O—C bond decomposable by an acid and a water-insoluble binder, and an interlayer made of amorphous silicic acid. After exposing the photosensitive lithographic printing plate which does not require dampening water with a rubber layer, the photosensitive layer solubilized using a developer is dissolved and removed, and at the same time, the silicone rubber layer on top is also removed, exposing the aluminum substrate. Department is proposed. However, in this case, the sensitivity is low, and most of the practically effective photoacid generators used in this technology absorb only at 450 nm or less. Not suitable for writing.

The present inventors have previously described Japanese Patent Application Laid-Open No. 9-120157.
No., resol resin / novolak resin / infrared absorber /
There is disclosed a digitally recordable fountain solution-free photosensitive lithographic printing plate in which a silicone rubber layer is laminated on a photosensitive layer containing a compound capable of generating an acid by heat. Although the printing plate disclosed herein is digitally recordable, its stability, especially when stored for a long period of time at a high temperature such as midsummer or a high-temperature region, is not always sufficient, and uniform development is not possible. Difficult things have been found.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to directly record digital data from a computer or the like using a solid-state laser or semiconductor laser (heat mode) having a light emitting region from near infrared to infrared. And a photosensitive lithographic printing plate requiring no dampening solution for direct plate making and having excellent thermal stability.

[0008]

The photosensitive lithographic printing plate requiring no dampening solution of the present invention comprises a support, on which a photosensitive layer and a silicone rubber layer are sequentially laminated, wherein the photosensitive layer comprises at least (a) At least one selected from the following crosslinkable compounds:
(a-1) an aromatic compound substituted with an alkoxymethyl group or a hydroxymethyl group, (a-2) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, and (a -3) at least one selected from the group consisting of epoxy compounds, (b) an alkali-soluble binder, (c) an infrared absorber, and (d)
It is characterized by containing a compound that generates an acid by heat (hereinafter, referred to as an acid precursor).

According to the present invention, a positive or negative type lithographic printing plate not requiring a dampening solution is obtained depending on the conditions for forming the photosensitive film. When creating a positive fountain solution-free lithographic printing plate, after generating an acid from the acid precursor in the exposed portion by image exposure, heat is applied to react the crosslinking agent component and the alkali-soluble binder component. At the same time, the exposed portion is insolubilized and, at the same time, the adhesiveness of the silicone layer is increased to make it a non-image portion. On the other hand, when preparing a negative type lithographic printing plate requiring no dampening solution, image exposure can be performed to improve the solubility of the exposed portion and at the same time reduce the adhesiveness of the silicone rubber layer to form an image portion.

The constitution of the present invention, particularly the component (c)
By using the specific infrared absorber, good sensitivity can be obtained even when digital data is directly recorded by using a solid-state laser or a semiconductor laser (thermal mode), and the component (a)
By applying the specific crosslinking compound to the alkali-soluble binder of the component (b), a printing plate excellent in heat stability can be obtained, and the printing plate can be used in both positive and negative printing plates. A positive or negative image can be satisfactorily obtained by simple processing after exposure without writing time.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. The photosensitive layer used in the present invention is a photosensitive composition containing the above components (a), (b), (c) and (d). First,
The crosslinkable compound of the component (a) of the present invention will be described.
(a-1) Examples of the aromatic compound substituted with an alkoxymethyl group or a hydroxymethyl group include, for example, an aromatic compound and a heterocyclic compound poly-substituted with a hydroxymethyl group, an acetoxymethyl group, or an alkoxymethyl group. No. However, it does not include resinous compounds obtained by polycondensing phenols and aldehydes known as resol resins under basic conditions. Although the resole resin is excellent in crosslinkability, it does not have sufficient thermal stability. In particular, when the resol resin is contained in a photosensitive material and stored at a high temperature for a long period of time, uniform development becomes difficult, which is not preferable.

Among aromatic compounds and heterocyclic compounds poly-substituted with a hydroxymethyl group or an alkoxymethyl group, a compound having a hydroxymethyl group or an alkoxymethyl group at a position adjacent to the hydroxy group may be mentioned as a preferred example. it can. In the case of an alkoxymethyl group, the alkoxymethyl group is preferably a compound having 18 or less carbon atoms. Particularly preferred examples include compounds represented by the following general formulas (1) to (4).

[0013]

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[0014]

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In the above formulas, L _{1 to} L ₈ each independently represent a hydroxymethyl group or an alkoxymethyl group substituted by an alkoxy group having 18 or less carbon atoms, such as methoxymethyl, ethoxymethyl and the like. These are preferred because they have high crosslinking efficiency and can improve printing durability. The crosslinking compounds exemplified above may be used alone or in combination of two or more.

(A-2) As the compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, European Patent Publication (hereinafter referred to as EP-A) 0,133,216 No. 3, West German Patent 3,6
No. 34,671, No. 3,711,264, monomer and oligomer-melamine-formaldehyde condensate and urea-formaldehyde condensate, EP-A
And the alkoxy-substituted compounds disclosed in No. 0,212,482. More preferred examples include, for example, at least two free N-hydroxymethyl groups, N
Melamine-formaldehyde derivatives having an -alkoxymethyl group or an N-acyloxymethyl group are exemplified, and among them, an N-alkoxymethyl derivative is particularly preferred.

(A-3) Examples of the epoxy compound include monomer, dimer, oligomer, and polymer epoxy compounds containing one or more epoxy groups. For example, a reaction product of bisphenol A with epichlorohydrin, a reaction product of a low molecular weight phenol-formaldehyde resin with epichlorohydrin and the like can be mentioned. Other examples include epoxy resins described and used in U.S. Pat. No. 4,026,705 and British Patent 1,539,192.

The crosslinkable compound according to the present invention is 5 to 80% by weight, preferably 1% by weight, based on the total solids of the waterless lithographic printing plate material.
The range is from 0 to 75% by weight, particularly preferably from 20 to 70% by weight. If the addition amount of the crosslinking compound is less than 5% by weight, the durability of the photosensitive layer of the obtained waterless lithographic printing plate material is deteriorated, and if it exceeds 80% by weight, it is not preferable from the viewpoint of storage stability. .

As the alkali-soluble binder (b) used in the present invention, novolak resin, polyhydroxystyrene, acrylic resin and the like can be mentioned. The novolak resin used in the present invention is a resin obtained by condensing phenols and aldehydes under acidic conditions. Preferred novolak resins include, for example, novolak resins obtained from phenol and formaldehyde,
Novolak resin obtained from m-cresol and formaldehyde, novolak resin obtained from p-cresol and formaldehyde, novolak resin obtained from o-cresol and formaldehyde, novolak resin obtained from octylphenol and formaldehyde, m− /
Novolak resin obtained from p-mixed cresol and formaldehyde, phenol / cresol (o-, m-,
p- or m- / p-, m- / o- or o- / p-mixture) and a novolak resin obtained from formaldehyde. These novolak resins have a weight average molecular weight of 800 to 200,000,
Those having a number average molecular weight of 400 to 60,000 are preferred.

Examples of the alkali-soluble binder other than the novolak resin used in the present invention include polyhydroxystyrenes, hydroxystyrene-N-substituted maleimide copolymers, hydroxystyrene-maleic anhydride copolymers, and alkali-soluble groups. Acrylic polymer having the same, a urethane type polymer having an alkali-soluble group, and the like. Here, examples of the alkali-soluble group include a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, a phosphonic acid group, and an imide group.

Also, hydroxystyrene polymers such as poly-p-hydroxystyrene, poly-m-hydroxystyrene, p-hydroxystyrene-N-substituted maleimide copolymer and p-hydroxystyrene-maleic anhydride copolymer are used. When used, the weight average molecular weight is
500,000, and more preferably 4000 to 300,000.

Examples of the acrylic polymer having an alkali-soluble group include methacrylic acid-benzyl methacrylate copolymer, poly (hydroxyphenylmethacrylamide), poly (hydroxyphenylcarbonyloxyethyl acrylate), poly (2,4-dihydroxy Phenylcarbonyloxyethyl acrylate), and the polymers described in Japanese Patent Application No. Hei 8-211731. These acrylic polymers have a weight average molecular weight of 2
000 to 500,000, preferably 4000 to 30
000 is preferred.

Examples of urethane-type polymers having an alkali-soluble group include resins obtained by reacting diphenylmethane diisocyanate with hexamethylene diisocyanate, tetraethylene glycol, 2,2-bis (hydroxymethyl) propionic acid, and the like. Among these alkali-soluble polymers, a hydroxystyrene-based polymer and an acrylic copolymer having an alkali-soluble group are preferred from the viewpoint of developability.

In the present invention, these alkali-soluble binders are used in an amount of 10 to 90% by weight, preferably 20 to 85% by weight, particularly preferably 30 to 90% by weight, based on the total solid content of the image recording material.
It is used at an addition amount of ８０80% by weight. When the amount of the alkali-soluble polymer compound is less than 10% by weight, the durability of the recording layer is deteriorated.
It is not preferable in terms of durability. Also, these alkali-soluble binders may be used alone,
Alternatively, two or more types may be used in combination.

In the present invention, various known pigments or dyes are used as the infrared absorbent (c).
Carbon black is preferably used as a pigment that absorbs infrared light. Examples of dyes that absorb infrared light include cyanine-based, merocyanine-based, phthalocyanine-based, squarylium-based, metal dithiolenes, naphthoquinone-based, and pyrylium-based dyes.
num Press, New York, NY (1990)), and cyanines described in JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, and JP-A-60-78787. Dye, JP-A-58-173696
Methine dyes described in JP-A Nos. 58-181690 and 58-194595;
No. 93, No. 58-224793, No. 59-48187
Nos. 59-73996, 60-52940 and 60-63744, squarylium dyes described in JP-A-58-112792, and British Patent 434,875. The described cyanine dyes and the like are preferably used. U.S. Pat.
No. 156,938, a near-infrared absorber, U.S. Pat.
Substituted arylbenzo (thio) pyrylium salts described in JP-A-881,924, trimethinethiopyrylium salts described in JP-A-57-142645, JP-A-58-18105.
No. 1, No. 58-220143, No. 59-41363
Nos. 59-84248, 59-84249, 59-146063, and 59-146061; pyrylium compounds described in JP-A-59-216146; cyanine dyes described in JP-A-59-216146; U.S. Pat. No. 475, pentamethine thiopyrylium salt and JP-B 5-1351.
The pyrylium compounds disclosed in JP-A Nos. 4 and 5-19702 are particularly preferably used.

Another particularly preferred example is a near-infrared absorbing dye described as formulas (I) and (II) in US Pat. No. 4,756,993. These pigments or dyes are used in an amount of 0.01 to 50% by weight, preferably 0.1 to 50% by weight, based on the total solid content of the photosensitive layer composition.
It can be added in a proportion of 20% by weight.

As the compound (acid precursor) that generates an acid by heat (d) used in the present invention, known compounds that generate an acid and mixtures thereof can be appropriately selected and used. . For example, SI Schlesinger, Photogr. S
ci. Eng., 18, 387 (1974), TS Bal et al, Polyme
r, 21, 423 (1980), diazonium salts, U.S. Pat.Nos. 4,069,055 and 4,069,056, ammonium salts described in the specification of JP-A-4-365049, DC Necker et al.
Macromolecules, 17, 2468 (1984), CS Wen et al, T
eh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct
(1988), U.S. Patent Nos. 4,069,055 and 4,069,056, JV Crivello et al, Macromor
ecules, 10 (6), 1307 (1977), Chem. & Eng. News, No.
v. 28, p31 (1988), European Patent No. 104,143, U.S. Pat.Nos. 339,049 and 410,201, JP-A-2-150848, Iodonium salts described in JP-A-2-295514, JV Crivel
lo et al, Polymer J. 17, 73 (1985), JV Crivello
et al. J. Org. Chem., 43, 3055 (1978), WR Watt e
t al, J. Polymer Sci., Polymer Chem. Ed., 22, 1789
(1984), JV Crivello et al, Polymer Bull., 14,
279 (1985), JV Crivello et al, Macromorecule
s, 14 (5), 1141 (1981), JV Crivelloet al, J. Pol
ymer Sci., Polymer Chem.Ed., 17, 2877 (1979), European Patent Nos. 370,693, 3,902,114, 233,567,
Nos. 297,443 and 297,442; U.S. Patent No. 4,933,377
Nos. 161,811, 410,201, 339,049, 4,
760,013, 4,734,444, 2,833,827, German Patent Nos. 2,904,626, 3,604,580, and 3,604,581, sulfonium salts described in JV Crivello et al, Macrom
orecules, 10 (6), 1307 (1977), JV Crivello et a
l, J. Polymer Sci., Polymer Chem. Ed., 17, 1047 (1
979), CS Wen et al, Teh,
Proc. Conf. Rad. CuringASIA, p478 Tokyo, Oct (198
Onium salts such as arsonium salts described in 8), U.S. Pat.
3,905,815, JP-B-46-4605, JP-A-48-36281,
JP-A-55-32070, JP-A-60-239736, JP-A-61-169
835, JP-A-61-169837, JP-A-62-58241, JP-A-62-212401, JP-A-63-70243, JP-A-63-298339
Organohalogen compounds described in K. Meier et al, J. R
ad. Curing, 13 (4), 26 (1986), TP Gill et al, In
org.Chem., 19, 3007 (1980), D. Astruc, Acc. Ch.
em. Res., 19 (12), 377 (1896), and organometallic / organic halides described in JP-A-2-14145, S. Hayase et al,
J. Polymer Sci., 25, 753 (1987), E. Reichmanis
et al, J. Polymer Sci., Polymer Chem. Ed., 23, 1
(1985), QQ Zhu et al, J. Photochem., 36, 85,
39, 317 (1987), B. Amit et al, Tetrahedron Lett.,
(24) 2205 (1973), DHR Barton et al, J. Chem So
c., 3571 (1965), PM Collins et al, J. Chem. So
c., PerkinI, 1695 (1975), M. Rudinstein et al, Tet.
rahedron Lett., (17), 1445 (1975), JW Walker e
t al, J. Am. Chem. Soc., 110, 7170 (1988), SC
Busman et al, J. Imaging Technol., 11 (4), 191 (198
5), HM Houlihan et al, Macoromolecules, 21, 200
1 (1988), PM Collins etal, J. Chem. Soc., Chem.
Commun., 532 (1972), S. Hayase et al, Macromolecu
les, 18, 1799 (1985), E. Reichmanis et al, J. Ele
ctrochem. Soc., Solid State Sci. Technol., 130
(6), FM Houlihan et al, Macromolecules, 21, 2001.
(1988), European Patent Nos. 0290,750, 046,083, and 15
Nos. 6,535, 271,851, 0,388,343, U.S. Pat.
3,901,710, 4,181,531, JP-A-60-198538,
A photoacid generator having an o-nitrobenzyl type protecting group described in JP-A-53-133022, M. Tunooka et al, Polymer Pr.
eprints Japan, 38 (8), G. Berner et al, J. Rad. Curi
ng, 13 (4), WJ Mijs et al, Coating Technol., 55 (6
97), 45 (1983), Akzo, H. Adachi et al, PolymerPrep.
rints, Japan, 37 (3), European Patent Nos. 0199,672 and 8451
No. 5, No. 199,672, No. 044,115, No. 0101,122, U.S. Pat.Nos. 4,618,564, 4,371,605, 4,431,774
No., JP-A-64-18143, JP-A-2-245756, JP-A-4-36
Represented by iminosulfonate and the like described in No. 5048,
Compound that generates sulfonic acid by photolysis, JP-A-61-166
The disulfone compound described in No. 544 can be mentioned.

Compounds in which these acid-generating groups or compounds are introduced into the main chain or side chain of the polymer, for example, ME Woodhouse et al, J. Am. Chem. Soc., 104,
5586 (1982), SP Pappas et al, J. Imaging Sci.,
30 (5), 218 (1986), S. Kondo et al. Makromol. Che
m., Rapid Commun., 9,625 (1988), Y. Yamada et al, M.
akromol.Chem., 152, 153, 163 (1972), JV Crivel
lo et al. J. PolymerSci., Polymer Chem. Ed., 17, 3
845 (1979), U.S. Patent 3,849,137, German Patent 3,9
No. 14,407, JP-A-63-26653, JP-A-55-164824,
JP-A-62-69263, JP-A-63-1460387, JP-A-63-163
Compounds described in JP-A No. 452, JP-A-62-153853 and JP-A-63-146029 can be used.

Further, VNR Pillai, Synthesis, (1),
1 (1980), A. Abad et al, Tetrahedron Lett., (47) 45
55 (1971), DHR Barton et al, J. Chem. Soc.,
(C), 329 (1970), U.S. Pat. No. 3,779,778, and EP 126,712 can also be used.

Among the above-mentioned acid precursors, particularly effective ones will be described below. (1) An oxazole derivative represented by the following general formula (I) or an S-triazine derivative represented by the following general formula (II) substituted by a trihalomethyl group.

[0031]

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In the formula, R ¹ is a substituted or unsubstituted aryl or alkenyl group, and R ² is a substituted or unsubstituted aryl, alkenyl, alkyl or —CY.
Represents ₃ . Y represents a chlorine atom or a bromine atom. The oxazole derivative (I) and the S-triazine derivative (I
Specific examples of I) include the following I-1 to 8 and II-1
However, the present invention is not limited thereto.

[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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(2) An iodonium salt represented by the following general formula (III) or a sulfonium salt represented by the following general formula (IV).

[0039]

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In the formula, Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. Preferred substituents include an alkyl group, a haloalkyl group, a cycloalkyl group,
Examples include an aryl group, an alkoxy group, a nitro group, a carboxyl group, an alkoxycarbonyl group, a hydroxy group, a mercapto group, and a halogen atom. R ³ , R ⁴ and R
⁵ each independently represents a substituted or unsubstituted alkyl group or aryl group. Preferably, it is an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 8 carbon atoms or a substituted derivative thereof. Preferred substituents are an alkoxy group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a nitro group, a carboxyl group, a hydroxy group or a halogen atom for the aryl group, and a carbon atom for the alkyl group. 1 to 8 alkoxy groups, carboxyl groups, and alkoxycarbonyl groups.

[0041] Z ^- represents a counter anion, for example BF ₄ -,
AsF ₆ −, PF ₆ −, SbF ₆ −, SiF ₆ −, ClO ₄ −, CF ₃ SO
-, BPh ₄ - (Ph = phenyl), naphthalene-1-sulfonic acid anion, anthraquinone sulfonic acid anion,
Examples thereof include, but are not limited to, condensed polynuclear aromatic sulfonic acid anions such as 9,10-dimethoxyanthracene-2-sulfonic acid anion, and a sulfonic acid group-containing dye.

Further, two of R ³ , R ⁴ and R ⁵ and Ar ¹ and Ar ² may be bonded through a single bond or a substituent. The onium salts represented by the general formulas (III) and (IV) are known, for example, JW Kn
apczyk et al, J. Am. Chem. Soc., 91, 145 (1969),
AL Maycoket al, J. Org.Chem., 35, 2532 (197
0), E. Goethas et al, Bull. Soc. Chem. Belg., 73,
546, (1964), HM Leicester, J. Am. Chem. Soc., 5
1, 3587 (1929), JB Crivello et al, J. Polym. Ch
em. Ed., 18, 2677 (1980), U.S. Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101331.

Specific examples of the onium compounds of the general formulas (III) and (IV) include the following compound III-1
-20 and IV-1 to 34, but are not limited thereto.

[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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(3) Disulfone derivatives represented by the following general formula (V) or iminosulfonate derivatives represented by the following general formula (VI). Ar ³ —SO ₂ —SO ₂ —Ar ⁴ (V)

[0060]

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Where Ar^ThreeAnd Ar^FourAre each independently substituted
Or an unsubstituted aryl group. R ⁶Is replaced or not
Represents a substituted alkyl group or an aryl group. A¹Also replace
Or an unsubstituted alkylene group, alkenylene group or
Represents a diene group. Represented by the general formulas (V) and (VI)
Specific examples of the compound include compounds V-1 to V-1 shown below.
2 and VI-1 to 12, but are not limited thereto.
It is not something to be done.

[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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The addition amount of these acid precursors is in the range of 0.001 to 40% by weight, preferably in the range of 0.1 to 20% by weight, based on the total solid content of the photosensitive layer composition. If the added amount of the acid precursor is too small, the sensitivity is lowered, and if it is too large, the sensitivity does not rise above a certain level, which is disadvantageous in cost.

Examples of the printing-out agent for obtaining a visible image immediately after exposure include a combination of a compound which releases an acid by heat due to exposure and an organic dye which can form a salt. Specifically, a combination of o-naphthoquinonediazide-4-sulfonic acid halogenide and a salt-forming organic dye described in JP-A-50-36209 and JP-A-53-8128, and JP-A-53-36223. JP-A-54-74
No. 728, a combination of a trihalomethyl compound and a salt-forming organic dye. Dyes other than the salt-forming organic dyes described above can also be used as colorants for images. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes or basic dyes. Specifically, for example, Oil Yellow # 101, Oil Yellow # 130, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Black BY, Oil Black BS,
Oil black T-505 (all manufactured by Oriental Chemical Industry Co., Ltd.), crystal violet (CI4255)
5), methyl violet (CI42535), rhodamine B (CI45170B), malachite green (C
I42000), methylene blue (CI52015) and the like.

These dyes are used in an amount of 0.01 to 10% by weight, preferably 0.1 to 3% by weight, based on the total solid content of the photosensitive layer composition.
It can be added to the photosensitive layer composition in a proportion of% by weight. In addition, when a visible image having a sufficient density can be obtained by the infrared absorbent of the present invention, it is not necessary to add such a dye.

In the photosensitive layer composition of the present invention, alkyl ethers (for example, ethyl cellulose and methyl cellulose) for improving coating properties, silicone surfactants, fluorine surfactants and fluorine surface alignments may be used, if necessary. Agents, plasticizers for imparting film flexibility and abrasion resistance (for example, tricresyl phosphate, dimethyl phthalate,
Trioctyl phosphate, tributyl phosphate, tributyl citrate, polyethylene glycol, polypropylene glycol, etc.) and additional sensitizers and the like. Further, a silane coupling agent, a titanium coupling agent, or the like may be added to enhance the adhesiveness with the silicone rubber layer. The amount added varies depending on the purpose of use, but is generally 0.3 to 30% by weight based on the total solid content of the photosensitive layer composition.
It is.

The photosensitive layer composition of the present invention is dissolved in a solvent that dissolves the above-mentioned components and used for coating. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether,
1-methoxy-2-propanol, ethylene glycol monoethyl ether, 2-methoxyethyl acetate,
1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, There are toluene, ethyl acetate, dioxane and the like, and these solvents are used alone or as a mixture.

The concentration of the above components (total solids including additives) in the solvent is preferably 2 to 50% by weight. The coating amount is generally preferably 0.2 to 5.
0 g / m ² , more preferably 0.3 to 3.0 g
/ M ² .

The above coating solution is coated on a support using a known coating technique. Examples of the coating technique include spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, curtain coating, and spray coating.

The support used in the present invention must be flexible enough to be set in an ordinary printing press and withstand the load applied during printing. Accordingly, typical supports include coated paper, metal plates such as aluminum, plastic films such as polyethylene terephthalate, rubber, and composites thereof, and more preferably aluminum and aluminum-containing ( For example, it is an alloy (alloy) of aluminum with a metal such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth and nickel.

In the present invention, a primer layer may be provided between the support and the photosensitive layer. As the primer layer used in the present invention, various layers can be used for improving adhesion between the substrate and the photosensitive layer, preventing halation, dyeing an image, and improving printing characteristics. For example, JP
Various photosensitive polymers such as those disclosed in Japanese Patent No. 22903 are exposed and cured before laminating a photosensitive layer, and the epoxy resins disclosed in Japanese Patent Application Laid-Open No. 62-50760 are thermally cured. JP-A-63-13
No. 3,151, hardened gelatin, further disclosed in JP-A-3-200965, using a urethane resin and a silane coupling agent, and disclosed in JP-A-3-273248. And the like using a urethane resin.
In addition, those obtained by hardening gelatin or casein are also effective. For the purpose of further softening the primer layer, polyurethane, polyamide, styrene / butadiene rubber having a glass transition temperature of room temperature or lower in the primer layer,
Polymers such as carboxy-modified styrene / butadiene rubber, acrylonitrile / butadiene rubber, carboxylic acid-modified acrylonitrile / butadiene rubber, polyisoprene, acrylate rubber, polyethylene, chlorinated polyethylene, and chlorinated polypropylene may be added. The addition ratio is arbitrary, and the primer layer may be formed with only the additive as long as the film layer can be formed. In addition, these primer layers are provided with a dye, a pH indicator, a printing-out agent, a photopolymerization initiator, and an adhesion assistant (for example, polymerizable monomers, diazo resins, silane coupling agents, titanate coupling agents, aluminum Coupling agents), pigments, and additives such as silica powder and titanium oxide powder. After the application, it can be cured by exposure. Generally, the coating amount of the primer layer is suitably in the range of 0.1 to 20 g / m ² , preferably 1 to 10 g / m ² , and more preferably 1 to 5 g / m ^2.
2

The crosslinked silicone rubber layer used in the present invention is a film formed by curing the following composition A or B.

Composition A Diorganopolysiloxane (number average molecular weight is 3,000 to 40,000) 100 parts by weight Condensation type crosslinking agent 3 to 70 parts by weight Catalyst 0.01 to 40 parts by weight A polymer having a repeating unit represented by the formula:
⁷ and R ⁸ are an alkyl group having 1 to 10 carbon atoms, a vinyl group or an aryl group, and may have other suitable substituents. Generally, 60% of R ⁷ and R ⁸
The above are preferably a methyl group, a vinyl halide group, a halogenated phenyl group, or the like.

[0081]

Embedded image

It is preferable to use a diorganopolysiloxane having hydroxyl groups at both ends. In addition, the component f has a number average molecular weight of 3,000 to 40,000,
More preferably, it is 5,000 to 36,000. The components may be of any type as long as they are of the condensation type, but those represented by the following general formula are preferred.

R ⁷ _m · Si · X _n (m + n = 4, n is 2 or more)
Here, R ⁷ has the same meaning as R ⁷ described above, and X is a substituent as shown below. Halogen such as Cl, Br, I, etc. H or OH, OCOR ⁹ , OR ⁹ , -ON = CR
¹⁰ R ^11, an organic substituent such as -NR ¹⁰ R ^11.

Here, R ⁹ is an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 20 carbon atoms, and R ¹⁰ and R ¹¹ are an alkyl group having 1 to 10 carbon atoms. The components are tin, zinc,
Examples of the metal carboxylate such as lead, calcium, and manganese include known catalysts such as dibutyl laurate, lead octylate, and lead naphthenate, and chloroplatinic acid.

Composition B Diorganopolysiloxane having an addition-reactive functional group (number average molecular weight: 3,000 to 100,000) 100 parts by weight Organohydrogenpolysiloxane 0.1 to 10 parts by weight Addition catalyst 0.00001 to 1 part by weight

The above-mentioned diorganopolysiloxane having an addition-reactive functional group is an organopolysiloxane having at least two alkenyl groups (more preferably, vinyl groups) directly bonded to silicon atoms in one molecule (number-average molecular weight). Is 3,000 to 40,000), and the alkenyl group may be at the terminal of the molecular chain or in the middle, and the organic group other than the alkenyl group is a substituted or unsubstituted alkyl group or aryl group having 1 to 10 carbon atoms. The component may optionally have a small amount of hydroxyl groups. The components have a number average molecular weight of 3,000 to 40,000, more preferably 5,000 to 36,0
00.

The components include polydimethylsiloxane having hydroxyl groups at both terminals, α, ω-dimethylpolysiloxane, (methylsiloxane) (dimethylsiloxane) copolymer having methyl groups at both terminals, cyclic polymethylsiloxane, and trimethylsilyl group having both terminals. Examples thereof include polymethylsiloxane and a (dimethylsiloxane) (methylsiloxane) copolymer of trimethylsilyl groups at both terminals.

The component is arbitrarily selected from known ones, and a platinum compound is particularly desirable, and examples thereof include platinum alone, platinum chloride, chloroplatinic acid, and olefin-coordinated platinum. In order to control the curing rate of these compositions, organopolysiloxanes containing vinyl groups such as tetracyclo (methylvinyl) siloxane, alcohols containing carbon-carbon triple bonds, acetone, methyl ethyl ketone, methanol, ethanol, propylene glycol monomethyl ether It is also possible to add a crosslinking inhibitor such as.

The silicone rubber layer may optionally contain inorganic powders such as silica, calcium carbonate, and titanium oxide.
An adhesion aid such as the above-mentioned silane coupling agent, titanate coupling agent or aluminum-based coupling agent, or a photopolymerization initiator may be added. The silicone rubber layer in the present invention serves as a printing ink repellent layer. If the thickness is small, there are problems such as a decrease in ink repellency and easy damage, and if the thickness is large, the developability deteriorates. from, the thickness is preferably 0.5 to 5 g / m ^2, preferably from 1 to 3 g / m ^2.

In the photosensitive lithographic printing plate requiring no dampening solution described above, various silicone rubber layers may be further coated on the silicone rubber layer. Also, in order to increase the adhesive strength between the photosensitive layer and the silicone rubber layer, a silane-based or titanate-based coupling agent is added to the photosensitive layer or the silicone rubber layer, or the photosensitive layer and the silicone rubber layer are It is preferable to provide an intermediate layer containing the above coupling agent to promote the adhesion between the photosensitive layer and the silicone rubber layer.

Examples of the silane coupling agent used in the present invention include vinyl silanes such as vinyl trichlorosilane, vinyl trimethoxy silane and vinyl triethoxy silane, γ-glycidoxypropyl trimethoxy silane,
Epoxysilanes such as γ-glycidoxypropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β
Aminosilanes such as (aminoethyl) γ-aminopropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-methacryloxypropylmethoxysilane, γ-methacryloxypropylmethyldiethoxysilane (Meth) acryloylsilanes.

The titanate coupling agents used in the present invention include alkyl titanates such as tetra-i-propyl titanate, tetra-n-butyl titanate and tetrastearyl titanate, and di-i-propoxybis (acetylacetonato) titanium. , Di-n-butoxy
Titanium chelates such as bis (acetonato) titanium, di-n-butoxybis (triethanolaminato) titanium, dihydroxybis (lactato) titanium, tetrakis (2-ethylhexanediolite) titanium, and tri-n-butoxytitanium mono Also included are stearate, titanium acylate such as titanium tetrabenzoate, or an association or polymer thereof. Further, i-propyl tri (dioctyl phosphate) titanate, bis (dioctyl phosphate) ethylene titanate,
Phosphorus-containing titanates such as i-propyl tris (dioctyl pyrophosphate) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate can also be used.

Further, in order to protect the surface of the silicone rubber layer, a transparent film such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, cellophane, etc. is laminated on the silicone rubber layer, A coating may be applied. These films may be used after being stretched. These films may be provided with a mat.

The photosensitive lithographic printing plate requiring no dampening solution of the present invention is usually subjected to image exposure and development steps. The light source for the actinic rays used in the printing plate of the present invention is preferably a light source having an emission wavelength in the near infrared to infrared region, for example, a solid laser,
Semiconductor lasers are particularly preferred. However, depending on the type of acid precursor used, it is possible to form an image with an electron beam, X-ray, ion beam, far ultraviolet, etc., in addition to ultraviolet rays of a mercury lamp, metal halide lamp, xenon lamp, chemical lamp, carbon arc lamp. is there. G-line, i-line, and Deep-UV light used as a light source for a photoresist can be used, and scanning exposure using a high-density energy beam (laser beam or electron beam) can also be used in the present invention. Such a laser beam is helium
Examples include a neon laser, an argon laser, a krypton ion laser, a helium / cadmium laser, and a KrF excimer laser.

In the present invention, when a positive type lithographic printing plate requiring no dampening solution is prepared, it is heated after exposure to promote the insolubilization reaction by the acid generated from the acid precursor. This heating step is preferably performed at a temperature in the range of 80 to 150 ° C. for 5 seconds to 20 minutes.

The photosensitive lithographic printing plate which does not require dampening water after exposure and, if necessary, a heating step is capable of dissolving or swelling part or all of the photosensitive layer in the image area, or swelling the silicone rubber layer. Developed with a developing solution. In this case, the photosensitive layer in the image area and the silicone rubber layer thereon may be removed, or only the silicone rubber layer in the image area may be removed, which can be controlled by the strength of the developer.

As the developer used for developing the photosensitive layer composition of the present invention, those known as developers for photosensitive lithographic printing plates requiring no dampening solution can be used. For example, aliphatic hydrocarbons [hexane, heptane, "Isoper E, H, G" (trade name of aliphatic hydrocarbons manufactured by Esso Chemical) or gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, xylene) Or the like, or a mixture of a halogenated hydrocarbon (such as tricrene) with the following polar solvent or the polar solvent itself.・ Alcohols (methanol, ethanol, propanol, benzyl alcohol, ethylene glycol monophenyl ether, 2-methoxyethanol, 2-ethoxyethanol, carbitol monomethyl ether, carbitol monoethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl Ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, propylene glycol, polypropylene glycol, triethylene glycol, tetraethylene glycol) Ketones (acetone, methyl ethyl ketone) Esters (ethyl acetate, methyl lactate) , Ethyl lactate,
Butyl lactate, propylene glycol monomethyl ether acetate, carbitol acetate, dimethyl phthalate, diethyl phthalate) Others (triethyl phosphate, tricresidyl phosphate) Also, water is added to the organic solvent-based developer or the solvent is added to the interface. Solubilized in water using an activator, and further an alkali agent such as sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate Inorganic alkaline agents such as ammonium tribasic acid, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, aqueous ammonia, tetraalkyl ammonium hydride, monoethanolamine, diethanolamine, triethanolamine. It may be added an organic alkali agent such as emissions.

In some cases, tap water or alkaline water can be used simply as a developer, and a surfactant or an organic solvent as described above can be added as necessary. Further, it is also possible to add a dye such as crystal violet or Astrazone Red to the developing solution and simultaneously carry out development and dyeing of the image area. Developing, for example, rubbing the plate surface with a developing pad containing a developer as described above, or rubbing with a developing brush in water after pouring the developer onto the plate surface,
It can be performed by a known method. The developer can be developed at any temperature, but is preferably from 10C to 50C.

The printing plate thus obtained can be detected by dyeing the exposed image portion with a dyeing solution in order to confirm the image forming property. When the developing solution does not contain a dye for dyeing the exposed image portion, it is dyed with the dyeing solution after development. By impregnating the dyeing solution with a soft pad and gently rubbing the image area, only the image area is dyed, whereby it can be confirmed that development is sufficiently performed up to the highlight area. As the dyeing solution, one or more selected from water-soluble disperse dyes, acid dyes and basic dyes are dissolved in water, alcohols, ketones, ethers or the like alone or in a mixture of two or more. Alternatively, those dispersed are used. It is also effective to add carboxylic acids, amines, surfactants, dyeing auxiliaries, defoamers and the like in order to improve the dyeability.

The printing plate dyed with the dyeing solution is preferably washed with water and then dried, whereby the stickiness of the printing plate surface can be suppressed and the handling of the printing plate can be improved. When printing plates thus processed are stacked and stored, it is preferable to insert and insert a slip sheet to protect the plate surface.

The above-described development and dyeing, and subsequent washing and drying are preferably performed by an automatic processor. A preferable example of such an automatic processor is disclosed in
No. 220061.

[0102]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Examples 1 to 5 [Preparation of a photosensitive lithographic printing plate requiring no positive dampening solution] (Preparation of a substrate) A 0.24 mm thick 2S aluminum plate was prepared using 8
After immersion in a 10% aqueous solution of sodium tertiary phosphate maintained at 0 ° C. for 3 minutes to degrease, and grained with a nylon brush,
Etching was performed with sodium aluminate for about 10 minutes, and desmutting was performed with a 3% aqueous solution of sodium hydrogen sulfate. This aluminum plate is subjected to a current density of 2 A in 20% sulfuric acid.
Anodization was performed at / dm ² for 2 minutes.

A coating solution having the following composition was applied on the above support so as to have a dry film thickness of 1 μm, and heated (at 100 ° C., 1 ° C.).
Min) and dried to form a primer layer. 10 parts by weight of polyurethane (SAMPLEN IB1700D, manufactured by Sanyo Chemical Industries, Ltd.) 0.1 part by weight of hexafluorophosphate of a condensation polymer of p-diazodiphenylamine and paraformaldehyde ・ Surfactant (Defenser MCF323, large 0.03 parts by weight-Propylene glycol methyl ether acetate 50 parts by weight-Methyl lactate 20 parts by weight-Pure water 1 part by weight

Thereafter, FT261V UDNS ULTRA manufactured by Neark Co., Ltd.
-PLUS FLIPTOP PLATE MAKER Using a vacuum exposure machine, 20
The count was exposed.

(Preparation of Carbon Black Dispersion) A composition having the following weight ratio was dispersed with glass beads for 30 minutes, and the glass beads were removed by filtration to obtain a carbon black dispersion. -1 part by weight of carbon black-1.6 parts by weight of m-cresol formaldehyde novolak resin-1.6 parts by weight of cyclohexanone-3.8 parts by weight of methoxypropyl acetate

(Synthesis of Crosslinking Agent) 1- [α-methyl-α-
(4-hydroxyphenyl) ethyl] -4- [α, α-
Bis (4-hydroxyphenyl) ethyl] benzene 20
g was dissolved in 100 ml of an aqueous potassium hydroxide solution (10%). 60 ml of formalin (37%) was added dropwise to this reaction solution over 1 hour while stirring at room temperature. After the reaction solution was further stirred at room temperature for 6 hours, it was poured into an aqueous sulfuric acid solution to cause crystallization. The obtained paste-like precipitate was thoroughly washed with water, and then recrystallized from 30 ml of methanol to obtain a white powder. The yield was 20 g. The obtained compound was analyzed by NMR for 1- [α-methyl-α- (4-
It was found to be a hexamethylolated product of [hydroxyphenyl) ethyl] -4- [α, α-bis (4-hydroxyphenyl) ethyl] benzene. Reversed phase HPLC
(Column: Shimpac CLC-ODS, manufactured by Shimadzu Corporation, solvent: methanol / water = 60/40 → 90/10), the purity of the hexamethylol compound was 92%.

20 g of this hexamethylol compound was dissolved by heating in 1000 ml of methanol, 1 ml of concentrated sulfuric acid was added, and the mixture was heated under reflux for 12 hours. After cooling the reaction solution, 2 g of potassium carbonate was added, and the mixture was further stirred and concentrated.
After adding 00 ml, washing with water and drying, the solvent was distilled off to obtain a white solid. The yield was 22 g. The resulting compound is
NMR revealed that it was a hexamethoxymethylated product of 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] -4- [α, α-bis (4-hydroxyphenyl) ethyl] benzene. Reversed phase HPLC (column:
The purity of hexamethoxymethylated compound by Shimpac CLC-ODS, manufactured by Shimadzu Corporation, solvent: methanol / water = 60/40 → 90/10) was 90%. This compound corresponds to the crosslinkable compound (a-1) of the present invention.

(Photosensitive Layer) A photosensitive solution having the following composition was coated on the aluminum plate and dried at 90 ° C. for 1 minute. The weight after drying was 2 g / m ² . 10 parts by weight of the carbon black dispersion 5 parts by weight of the crosslinking agent 5 parts by weight of m-cresol formaldehyde novolak resin 10 parts by weight of the acid precursor in Table 1 Surfactant (Defenser MCF323, Dainippon Japan) 0.1 parts by weight ・ Methyl ethyl ketone 50 parts by weight

(Silicone Rubber Layer) The following silicone rubber composition was applied on the above photosensitive layer to a dry weight of 2 g / m ^2, and dried at 100 ° C. for 2 minutes. 9 parts by weight of α, ω-divinyl polydimethylsiloxane (degree of polymerization: about 700) ・ 0.5 parts by weight of (CH ₃ ) ₃ -Si-O- (SiH (CH ₃ ) -O) ₈ -Si (CH ₃ ) ₃ Parts ・ Polydimethylsiloxane (degree of polymerization approx. 8,000) 0.5 parts by weight ・ Olefin-chloroplatinic acid 0.08 parts by weight ・ Inhibitor (CH≡C-Si (CH ₃ ) ₂ OSi (CH ₃ ) ₃ ) 0.3 parts by weight ・ γ-methacryloxypropyltrimethoxysilane 0.3 parts by weight ・ Isoper E (manufactured by Esso Chemical Co., Ltd.) 140 parts by weight

An 8 μm-thick biaxially oriented polypropylene film was laminated on the surface of the silicone rubber layer obtained as described above to obtain a photosensitive lithographic printing plate requiring no dampening water. The printing plate obtained was adjusted to a plate surface output of 2 W by YAG.
After exposure with a laser, the laminated film was peeled off and heated in an oven at 100 ° C. for 3 minutes. After the heated printing plate was immersed in a liquid of tripropylene glycol at 40 ° C. for 1 minute, the surface of the printing plate was rubbed with a developing pad in water. A positive-type fountain solution-free lithographic printing plate was obtained in which the photosensitive layer was exposed in the remaining unexposed areas.

[0112]

[Table 1]

Example 7 Instead of the crosslinking agent used in Example 1, an intermediate of a synthesis example of the crosslinking agent, 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] -4- [α, A photosensitive lithographic plate was obtained in the same manner as in Example 1 using hexamethylolate of [alpha] -bis (4-hydroxyphenyl) ethyl] benzene. This compound corresponds to the crosslinkable compound (a-1) of the present invention. Exposure, heating, and development were performed in the same manner as in Example 1 to obtain a positive planographic printing plate.

Example 8 A photosensitive lithographic plate was obtained in the same manner as in Example 1, except that hexamethoxymethylmelamine was used in place of the crosslinking agent used in Example 1. This compound is a crosslinkable compound (a-
This corresponds to 2). Exposure, heating, and development were performed in the same manner as in Example 1 to obtain a positive planographic printing plate.

Example 9 An epoxy resin (Epicoat 1002, manufactured by Yuka Shell Epoxy Co.), which is a reaction product of bisphenol A and epichlorohydrin, was used in place of the crosslinking agent used in Example 1, and To obtain a photosensitive lithographic plate. This compound corresponds to the crosslinkable compound (a-3) of the present invention. Exposure, heating, and development were performed in the same manner as in Example 1 to obtain a positive planographic printing plate.

Example 10 Polyhydroxystyrene was used in place of the m-cresol formaldehyde novolak resin used in Example 1,
A photosensitive lithographic plate was obtained in the same manner as in Example 1. Exposure, heating, and development were performed in the same manner as in Example 1, and a positive planographic printing plate was waited.

Comparative Example 1 A resole resin (weight average molecular weight: 1600) obtained from bisphenol A and formaldehyde was used in place of the crosslinking agent used in Example 1, and a photosensitive lithographic plate was obtained in the same manner as in Example 1. Immediately after production, this lithographic plate gives the same positive-type fountain solution-free lithographic printing plate as in Example 1, but by storing it for a long time (3 days) under high temperature conditions (60 ° C.), However, it had a disadvantage that it did not peel off. The printing plates of Examples 1 to 10 did not have such a defect.

Example 11 A photosensitive lithographic printing plate was obtained in the same manner as in Example 1, except that the following dye was used in place of the carbon black dispersion used in Example 1.

Dye: 2,6-di-t-butyl-4- {5- (2,6-di-t-butyl-4H-thiopyran-4-ylidene) -penta-1,3-dienyl} thio Pyrilium tetrafluoroborate (the compound described in US Pat. No. 4,283,475) 0.02 parts by weight

The obtained photosensitive lithographic printing plate was exposed at a linear velocity of 8 m / sec and a plate surface output of 110 mW using a semiconductor laser (wavelength: 825 nm, spot diameter: 1 / e ² = 11.9 μm). When the same developing treatment as in Example 1 was performed, a positive type lithographic printing plate requiring no dampening solution was obtained.

Comparative Example 2 A printing plate was prepared in the same manner as in Example 9 except that 0.02 parts by weight of an oil-soluble dye (Victoria Pure-BOH) was used in place of the dye in the photosensitive solution composition of Example 11. did.
When this printing plate was exposed and developed in the same manner as in Example 9, the silicone rubber layer was peeled off over the entire surface, and no image was obtained.

Example 12 Instead of the silicone rubber layer used in Example 1, a silicone rubber solution having the following composition was applied on the photosensitive layer of Example 1 so as to have a dry weight of 2 g / m ² , After drying for 2 minutes, a cover film was provided to obtain a waterless planographic printing plate.

9 parts by weight of dimethylpolysiloxane having a hydroxyl group at both terminals (polymerization degree 700) 0.3 parts by weight of methyltriacetoxysilane 0.3 parts by weight of trimethoxysilylpropyl-3,5-diallyl isocyanurate 0.1 parts by weight of dibutyltin dioctanoate 0.3 parts by weight of γ-aminopropyltrimethoxysilane 160 parts by weight of Isopar E (manufactured by Esso Chemical Co., Ltd.)

This printing plate was exposed and developed in the same manner as in Example 1 to obtain a positive type lithographic printing plate requiring no dampening solution.

Example 13 [Preparation of a photosensitive lithographic printing plate requiring no negative dampening solution] Example 1
On the primer layer used in the above, the dye of the coating solution for the photosensitive layer used in Example 11 was replaced with a compound having the following structural formula, and
At 2 ° C. for 2 minutes, and dried at a coating weight of 2 g / m ^2.
Was obtained.

[0126]

Embedded image

The silicone rubber layer used in Example 1 was further applied and dried under the drying conditions of 140 ° C. for 2 minutes to obtain a silicone rubber layer having a coating weight of 2 g / m ² . A 6 μm-thick polyethylene terephthalate film was laminated on the surface of the silicone rubber layer obtained as described above to obtain a photosensitive lithographic printing plate requiring no dampening water.

After the obtained printing plate was exposed to a YAG laser adjusted to a plate surface output of 2 W, the laminated film was peeled off, and the printing plate was immersed in a liquid of tripropylene glycol at 40 ° C. for 1 minute, and then immersed in water. After rubbing the plate surface with a developing pad, a negative type fountain solution-free lithographic printing plate was obtained in which the silicone rubber remained in the unexposed areas and the photosensitive layer was exposed in the exposed areas.

Comparative Example 3 Bisphenol A was used in place of the crosslinking agent used in Example 13.
And a resole resin obtained from formaldehyde (weight average molecular weight: 1600), and a photosensitive lithographic plate was obtained in the same manner as in Example 13. This lithographic plate was prepared in Example 1 immediately after production.
The same positive type fountain solution-free lithographic printing plate as in 3 is given,
When stored under a high temperature condition (60 ° C.) for a long time (3 days), the silicone rubber layer was not uniformly peeled off. The printing plates of Examples 11 to 13 did not have such a defect.

Comparative Example 4 A printing plate was prepared in the same manner as in Example 8, except that 0.02 part by weight of an oil-soluble dye (Victoria Pure-BOH) was used in place of the dye in the photosensitive solution composition of Example 13. .
When this printing plate was exposed and developed in the same manner as in Example 13, the silicone rubber layer did not peel off on the entire surface and no image was obtained.

[0131]

According to the present invention, the photosensitive lithographic printing plate requiring no dampening solution can directly make a plate from a digital signal of a computer or the like using a solid-state laser or semiconductor laser having a light emitting region from near infrared to infrared. Further, a lithographic printing plate which can be used for both a positive type and a negative type and which does not require dampening solution for direct plate making and has excellent thermal stability can be obtained.

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI G03F 7/038 G03F 7/038

Claims (1)

[Claims] 1. A photosensitive layer and a silicone rubber layer are sequentially laminated on a support, wherein the photosensitive layer comprises: (a) at least one kind selected from the following crosslinkable compounds; Aromatic compound substituted with methyl group or hydroxymethyl group (a-2) Compound having N-hydroxymethyl group, N-alkoxymethyl group or N-acyloxymethyl group (a-3) Epoxy compound (b) Alkali A lithographic printing plate requiring no dampening solution, comprising: a soluble binder; (c) an infrared absorber; and (d) a compound capable of generating an acid by heat.