JPH0776832B2 - Photosensitive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive composition, and particularly to a photosensitive composition which is preferably used for a photosensitive lithographic printing plate. More specifically, it relates to a photosensitive composition which is preferably used for producing a photosensitive lithographic printing plate having excellent printing durability and inking property.

[Conventional technology]

The majority of those used as photosensitive substances in printing materials which have been presensitized are diazonium compounds, and among them, the most commonly used ones are diazo compounds represented by formaldehyde condensation products of p-diazodiphenylamine. There is resin.

The composition of the photosensitive layer of the photosensitive lithographic printing plate using a diazo resin, for example, as described in U.S. Pat.No. 2,714,066, the diazo resin alone, that is, without a binder, for example, As described in JP-A-50-30604, it can be classified into a mixture of a binder and a diazo resin. In particular, in recent years, many photosensitive lithographic printing plates using a diazonium compound have a photosensitive layer composed of a diazonium compound and a polymer serving as a binder in order to provide high printing durability.

Examples of such a photosensitive layer include a so-called alkaline developing type in which an unexposed portion is removed (developed) by an aqueous alkaline developing solution and an organic solvent-based developing solution as described in JP-A-50-30604. A so-called solvent-developing type which is removed is known. In recent years, attention has been paid to the alkali developing type from the viewpoint of occupational safety and health, which is mainly determined by the properties of the binder. As a method for imparting alkali developability to the binder, a carboxylic acid-containing monomer is copolymerized as described in JP-A-50-30604, or U.S. Pat.
There is a method of introducing a carboxylic acid into a polymer by reacting a hydroxyl group of polyvinyl alcohol with a cyclic acid anhydride such as phthalic anhydride as described in the specification. However, the polymer obtained is structurally
Only a lithographic printing plate having low printing durability was obtained from a photosensitive lithographic printing plate having poor abrasion resistance and containing such a binder in the photosensitive layer. On the other hand, polyvinyl acetal has a drawback that it forms a tough film and has abrasion resistance, but only an organic solvent-developing photosensitive lithographic printing plate can be obtained.

Therefore, attempts have been made to modify an abrasion-resistant polyvinyl acetal resin to be alkali-soluble. For example, as described in JP-B-51-10121,
After copolymerizing vinyl acetate and carboxylic acid-containing monomer,
Methods for saponification and acetalization have been proposed. However, even if the modified polyvinyl acetal obtained by the method is used, sufficient abrasion resistance cannot be obtained.

On the other hand, according to the method of introducing a substituent having an acidic hydrogen atom into the residual hydroxyl group of the polyvinyl alcohol resin which has been previously acetalized and modifying it to be alkali-soluble, the abrasion resistance of the original polyvinyl acetal resin is not significantly impaired. It was As such a method, for example, a method of introducing an arylsulfonyl urethane as described in British Patent No. 1370316, Japanese Patent Application No. 60-109122.
No. 60-123863 and No. 60-198742, a method of reacting an intramolecular acid anhydride of an organic polycarboxylic acid, and a method of introducing a component containing a hydroxyl group or a cyano group. And so on.

Further, there is a polyurethane resin as a known polymer having excellent wear resistance, which is disclosed in JP-B-49-36961 and JP-A-5-36196.
6-94346 discloses a combination system of a diazonium compound and a substantially linear polyurethane resin, and a combination system of a diazonium salt polycondensate and a branched polyurethane resin. However, none of these polyurethane resins has an alkali-soluble group, and the solubility in an aqueous alkaline developer is essentially insufficient, and it is very difficult to perform development without forming a residual film. there were.

Therefore, a polyurethane resin having a carboxyl group as described in Japanese Patent Application Nos. 60-263232 and 60-263233 has been proposed, which makes it possible to achieve both alkali developability and printing durability.

On the other hand, the inking property of the lithographic printing plate is an important property along with the developability and printing durability, and a method of adding a polymer compound as described in JP-A-55-527 has been proposed. However, further improvement is desired.

Further, the addition of a fluorine-containing surfactant for improving the coating property of the photosensitive composition is known from JP-A-54-135004, and such fluorine-containing surfactant is used as a fluorine-containing compound. There has never been a report that the inking property of a lithographic printing plate can be improved by selecting the content or the molecular weight.

[Problems to be solved by the invention]

The present invention is capable of alkali development and has high printing durability,
An object of the present invention is to provide a photosensitive composition suitable for producing a photosensitive lithographic printing plate having further improved inking property.

[Means for solving problems]

The present invention provides a finding that the above object can be achieved by using a polyurethane resin having a carboxyl group and / or a modified polyvinyl acetal resin introduced with a substituent having an acidic hydrogen atom and a specific fluorine-containing surfactant in combination. It was made based on this.

That is, the present invention provides a photosensitive composition containing a photosensitive diazo resin, a polymer binder and a fluorosurfactant, wherein the polymer binder is a polyurethane resin having a carboxyl group and / or a substituent having an acidic hydrogen atom. A modified polyvinyl acetal resin having a group introduced, wherein the fluorine-based surfactant has (i) 3 to 20 carbon atoms, contains 30% by weight or more of fluorine, and has at least 3 carbon atoms at the ends. An acrylate containing a fluoroaliphatic group (Rf group) which is completely fluorinated or a methacrylate containing an Rf group, and (ii) poly (oxyalkylene)
A copolymer with acrylate or poly (oxyalkylene) methacrylate, wherein the Rf group-containing acrylate or Rf group-containing methacrylate monomer unit is from 7 to 40% by weight based on the weight of the copolymer. The photosensitive composition has a molecular weight of 10,000 to 100,000.

The fluoroaliphatic group Rf of the fluorosurfactant used in the present invention is a saturated and generally monovalent aliphatic group. It is straight-chain, branched and, if sufficiently large, cyclic or combinations thereof (eg alkylcycloaliphatic radicals). The fluoroaliphatic backbone can include oxygen and / or trivalent nitrogen heteroatoms in the chain attached only to carbon atoms, which heteroatoms provide a stable bond between the fluorocarbon groups and Does not interfere with inert properties. In order to exert a sufficient effect, the Rf group has 3 to 20, preferably 6 to 12 carbon atoms and contains 30% by weight or more, preferably 40% by weight or more of fluorine bonded to carbon atoms. I have. At least three carbon atoms at the end of the Rf group are fully fluorinated. The end of the Rf group is, for example, CF ₃ C
F ₂ CF ₂ — and the preferred Rf group is a substantially fully fluorinated alkyl group such as CnF _{2n + 1} (n is an integer of 3 or more).

If the Rf group fluorine content is less than 30% by weight, the object of the present invention cannot be sufficiently achieved. It is more effective if the fluorine atom is localized at the end of the Rf group. Even if the number of carbon atoms in the Rf group is 2 or less, the fluorine content can be increased, but the total amount of fluorine atoms becomes insufficient and the effect is weak. Has 2 carbon atoms
Even if the fluorine content in the copolymer is increased by increasing the ratio of the following fully fluorinated Rf group-containing monomer to the copolymer, the fluorine atoms are not localized, No effect.

On the other hand, when the number of carbon atoms of the Rf group is 21 or more, the solubility of the obtained copolymer in a solvent becomes low when the fluorine content is high, and when the fluorine content is low, the localization of the fluorine atoms is sufficient. It is no longer possible to obtain a sufficient effect.

Solubilising moieties in the copolymer poly (oxyalkylene) group (OR ') a _x, R' is an alkylene group having 2 to 4 carbon atoms, such as _{-CH 2 CH 2 -, - CH} 2 CH ₂ CH ₂ −, −C
_{H (CH 3) CH 2 -} , or _{-CH (CH 3) CH (CH} 3) - is preferably. The oxyalkylene units in the poly (oxyalkylene) group may be the same as in poly (oxypropylene), or two or more kinds of oxyalkylene different from each other may be randomly distributed. Well, it may be linear or branched oxypropylene and oxyethylene units, or it may be present as a block of linear or branched oxypropylene units and a block of oxyethylene units. . The poly (oxyalkylene) chain may be one or more chain bonds (eg May be mediated by or may include these. When the linkages in the chain have three or more valences,
This provides the means to obtain branched oxyalkylene units. Further, when this copolymer is added to the photosensitive composition, in order to obtain the desired solubility, the molecular weight of the poly (oxyalkylene) group is appropriately 250 to 2,500, and the object of the present invention is sufficiently achieved. Therefore, the molecular weight of the poly (oxyalkylene) group is preferably 600 to 2,500. When the molecular weight of the poly (oxyalkylene) group is 250 to 600, the copolymer can be dissolved, but the number of poly (oxyalkylene) group-containing monomer units is large and the Rf group is not localized in the copolymer. Therefore, the effect is insufficient. On the contrary, the larger the molecular weight of the poly (oxyalkylene group), the smaller the number of the poly (oxyalkylene) group-containing monomer units, and the Rf group is localized in the copolymer, so that the effect is sufficiently exhibited.
However, if the molecular weight is 2,500 or more, the solubility will decrease.

The copolymer used in the present invention is, for example, a fluoroaliphatic group-containing acrylate or a fluoroaliphatic group-containing methacrylate, and a poly (oxyalkylene) acrylate or poly (oxyalkylene) methacrylate,
It can be prepared, for example, by free radical initiated copolymerization with monoacrylates or diacrylates or mixtures thereof. The molecular weight of the polyacrylate oligomer can be adjusted by adjusting the concentration and activity of the initiator, the concentration of the monomer and the temperature of the polymerization reaction, and by adding a chain transfer agent such as a thiol such as n-octyl mercaptan. . As an example, a fluoroaliphatic-containing acrylate, Rf—R ″ —O ₂ C—CH═CH ₂ (where R ″ is, for example, sulfonamide alkylene, carbonamido alkylene, or alkylene), such as C ₈ F ₁₇ SO 4. _{When 2} N (C ₄ H ₉ ) CH ₂ CH ₂ O ₂ CCH = CH is copolymerized with poly (oxyalkylene) monoacrylate CH ₂ ═CHC (O) (OR ′) _x OCH ₃ , it has the following repeating units. A copolymer is obtained.

The above fluoroaliphatic group-containing acrylate is described in US Pat.
No. 803,615, No. 2642,416, No. 2,826,564, No. 3,
102,103, 3,282,905 and 3,304,278. The poly (oxyalkylene) acrylates and other acrylates useful for this purpose used in preparing the above copolymers are commercially available hydroxypoly (oxyalkylene) materials such as the trade name "Pluronic" (Asahi). Denka Kogyo Co., Ltd.], Adeka Polyether (Asahi Denka Kogyo Co., Ltd.), "Carbowax" [Carbowax (Glyco Products)
ts) Co.)], "Triton" [Triton (Rhom and Hass Co.)] and PEG
It can be produced by reacting a product sold as (Daiichi Kogyo Seiyaku Co., Ltd.) with acrylic acid, methacrylic acid, acrylic chloride or acrylic anhydride by a known method. Alternatively, poly (oxyalkylene) diacrylate produced by known methods, CH ₂ ═CHCO ₂ (R′O) _x COCH═CH ₂ , for example CH ₂ ═CHCO ₂ (C ₂ H ₄ O) ₁₀ (C ₃ H ₆ O) ₂₂ (C ₂ H ₄ O) ₁₀ COH = CH
_{When 2} is copolymerized with the above-mentioned fluoroaliphatic group-containing acrylate, a polyacrylate copolymer having the following repeating units is obtained.

Other fluoroaliphatic group-containing terminal ethylenically unsaturated monomers suitable for producing the copolymer used in the present invention include U.S. Pat.Nos. 2,592,069, 2,995,542, and 3,
No. 078,245, No. 3,081,274, No. 3,291,843 and No. 3,325,163 are described, the ethylenically unsaturated material suitable for producing the fluoroaliphatic group-containing terminal ethylenically unsaturated monomer is It is described in US Pat. No. 3,574,791.

The copolymer used in the present invention is a copolymer of a fluoroaliphatic group-containing acrylate or a fluoroaliphatic group-containing methacrylate and a poly (oxyalkylene) acrylate or a poly (oxyalkylene) methacrylate. Contains 7-40% by weight of monomer units, based on the weight of the oligomer, and has a molecular weight of 10,000.
~ 100,000. If the amount of the fluoroaliphatic group-containing monomer unit is less than 7% by weight, the coating film will not be evenly produced and will be uneven, while if it is more than 40% by weight, the inking property will be deteriorated.

Further, the copolymer molecular weight of less than 10,000 is not sufficiently effective for the inking property, and the copolymer molecular weight of more than 100,000 is not preferable because the solubility in a solvent decreases.

The preferred range of use of the fluorosurfactant used in the present invention is 0.01 to 10% by weight with respect to the photosensitive composition (coating component excluding the solvent), and a more preferred range of use is 0.05 to 5 It is in the range of% by weight. If the amount of the fluorine-based surfactant used is less than 0.01% by weight, the effect is insufficient, and
If it exceeds 10% by weight, the coating film may not be fully dried, and the performance as a photosensitive material (eg developability)
Adversely affect the.

The photosensitive diazo resin used in the present invention is a diazo resin represented by a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound such as formaldehyde.
In particular, an organic solvent-soluble diazo resin is preferably used.

Examples of the diazo resin include organic solvent-soluble diazo resin inorganic salts, which are reaction products of a condensate of P-diazodiphenylamine and formaldehyde or acetaldehyde, and hexafluorophosphate or tetrafluoroborate, and JP-B-47- 1167 and the sulfonates, such as P-toluenesulfonic acid or a salt thereof, propylnaphthalenesulfonic acid or a salt thereof, butylnaphthalenesulfonic acid or a salt thereof, dodecylbenzenesulfonic acid or a salt thereof. Examples thereof include a salt, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid or a salt thereof, dioctylnaphthalenesulfonic acid or a salt thereof, or an organic solvent-soluble diazo resin organic salt which is a reaction product with a mixture thereof.

In addition, as shown in Japanese Patent Laid-Open No. 58-27141
Also suitable is a mesitylene sulfonate obtained by condensing methoxy-4-diazo-diphenylamine with 4,4'-bis-methoxy-methyl-diphenyl ether.

A particularly preferred diazo resin is represented by the following general formula (I).

[Wherein R ₁ represents a hydrogen atom, an optionally substituted alkyl, alkoxy, hydroxy, carboxy ester, or carboxy group, R ₂ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group, R ₃ represents a hydrogen atom or an alkoxy group having 1 to 3 carbon atoms, and R ₄ represents an alkyl group having 6 to 18 carbon atoms. n represents an integer of 2 or more. Specific examples of R ₁ include a hydrogen atom, a methyl group at the 4′-position, an ethyl group, an n-propyl group, an iso-propyl group, a methoxy group, an ethoxy group, an n-propoxy group, and iso.
-Propoxy group, hydroxymethyl group, β-hydroxyethyl group, γ-hydroxypropyl group, methoxymethyl group, ethoxymethyl group, β-methoxyethyl group, β-ethoxyethyl group, hydroxy group, carboxy group, carbomethoxy group, Carboethoxy groups, etc., and these 2 '
-Or 3'positional isomers are included. R ₁ is preferably a hydrogen atom, a methyl group at the 4′-position, a methoxy group, a hydroxy group or a carboxy group, and most preferably a hydrogen atom.

Specific examples of R ₂ include a hydrogen atom, a methyl group, an ethyl group,
An n-propyl group, an iso-propyl group, a phenyl group and the like are included, and the most preferable one is a hydrogen atom.

Specific examples of R ₃ include a hydrogen atom, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, and the like, and the most preferable one is a hydrogen atom.

Specific examples of R ₄ include n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group and n-undecyl group at the 2-, 3- or 4-position. ,
n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, etc., and carbon number 6
Within the range of -18, an appropriately branched alkyl group and the like are included. R ₄ is preferably an alkyl group having 12 carbon atoms, particularly a straight chain one, that is, an n-dodecyl group is 4
The one in the − position is most preferable.

The content of the photosensitive diazo resin and the polymer binder described below in the photosensitive composition should be 3 to 40% by weight of the diazo resin and 97 to 60% by weight of the polymer binder based on the total amount of both of them. Is appropriate. The smaller the content of diazo resin is, the higher the sensitivity is. However, when it is lower than 3% by weight, it becomes insufficient for photocuring the polymer binder, and the photocured film is swollen by the developing solution during development and the film becomes weak. There is. On the other hand, if the content of the diazo resin is more than 40% by weight, the sensitivity becomes low and practically difficult. Therefore, the more preferable range is 5 to 30% by weight of the photosensitive diazo resin and 95 to 70% by weight of the polymer binder.

Further, the total amount of the photosensitive diazo resin and the polymer binder is 50 to 100% by weight, preferably 70 to 100% by weight in the photosensitive composition.

The polyurethane resin, which is a polymer binder used in the present invention, is a polyurethane resin mainly having a group having a carboxyl group in the main chain, and further a group having a hydroxyl group and / or a nitrile group, if necessary, preferably A polyurethane resin having a basic skeleton as a reaction product of a diisocyanate compound represented by the general formula (II) and a diol compound having a carboxyl group represented by (III) or (IV) is included.

OCN-R ₅ -NCO (II) In the formula, R ₅ represents a divalent aliphatic or aromatic hydrocarbon which may have a substituent. If necessary, R ₅ may have another functional group which does not react with an isocyanate group, for example, an ester, urethane, amide or ureido group.

R ₆ represents a hydrogen atom, an optionally substituted alkyl, aralkyl, aryl, alkoxy, aryloxy group, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms,
It represents an aryl group having 6 to 15 carbon atoms. R ₇ , R ₈ and R ₉ may be the same or different and each represents a single bond or a divalent aliphatic or aromatic hydrocarbon which may have a substituent. Preferably, an alkylene having 1 to 20 carbon atoms and 6 carbon atoms
To 15 arylene groups, more preferably C1 to C8 alkylene groups. If necessary, R ₇ , R ₈ and R ₉ may have another functional group that does not react with an isocyanate group, such as an ester, urethane, amide, ureido or ether group. Note that 2 or 3 of R ₆ , R ₇ , R ₈ and R ₉
Individual pieces may form a ring.

Ar represents a trivalent aromatic hydrocarbon which may have a substituent, and preferably an aromatic group having 6 to 15 carbon atoms.

Specific examples of the diisocyanate compound represented by the general formula (II) include those shown below.

That is, 2,4-tolylene diisocyanate, dimer of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-
Aromatic diisocyanate compounds such as dimethyl biphenyl-4,4'-diisocyanate; aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate; isophorone diisocyanate, 4,4'-methylenebis ( Cyclohexyl isocyanate), methylcyclohexane-2,
Alicyclic diisocyanate compounds such as 4 (or 2,6) diisocyanate and 1,3-bis (isocyanatomethyl) cyclohexane; diols such as adducts of 1 mol of 1,3-butylene glycol and 2 mol of tolylene diisocyanate And a diisocyanate compound, which is a reaction product of diisocyanate with the above.

Specific examples of the diol compound having a carboxyl group represented by formula (III) or (IV) include those shown below.

That is, 3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid, 2,2-bis (3-hydroxypropyl) propionic acid, Examples thereof include bis (hydroxymethyl) acetic acid, bis (4-hydroxyphenyl) acetic acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid and tartaric acid.

The hydroxyl group and / or nitrile group optionally contained in the polyurethane resin used in the present invention has a hydroxyl group and / or a nitrile group as a part of the carboxyl group derived from the general formula (III) or (IV). It can be contained in the polyurethane resin by reacting in the presence of a halogen compound and a base. Further, in the case of a nitrile group, it can be introduced into the polyurethane resin by using a diol compound having a nitrile group in combination with the diol compound of the general formula (III) or (IV).

The polyurethane resin used in the present invention is a diisocyanate compound represented by the general formula (II) and a general formula (III)
Alternatively, it may be formed from two or more kinds of diol compounds having a carboxyl group represented by (IV).

Further, a diol compound which does not have a carboxyl group and may have another substituent that does not react with isocyanate may be used together to the extent that alkali developability is not deteriorated.

Specific examples of such diol compounds include those shown below. That is, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 1,3-butylene glycol, 1,6-hexanediol, 2-butene-
1,4-diol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanedimethanol, tricyclodecanedimethanol, hydrogenated bisphenol A, water Added bisphenol F, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A,
Bisphenol F ethylene oxide adduct, bisphenol F propylene oxide adduct, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, hydroquinone dihydroxyethyl ether, p-xylylene glycol , Dihydroxyethyl sulfone, bis (2-hydroxyethyl) -2,4-tolylene dicarbamate, 2,4-tolylene-bis (2-hydroxyethyl carbamide), bis (2-hydroxyethyl) -m-xylylene dicarbamate, Examples thereof include bis (2-hydroxyethyl) isophthalate.

The polyurethane resin used in the present invention contains the above diisocyanate compound and diol compound in an aprotic solvent,
Add a known active catalyst according to each reactivity,
It is synthesized by heating. The molar ratio of diisocyanate and diol compound used is preferably 0.8: 1.
When the isocyanate group remains at the polymer terminal, it is treated with alcohols or amines to finally synthesize the isocyanate group without leaving the isocyanate group.

The molecular weight of the polyurethane resin is preferably a weight average.
It is 1000 or more, and more preferably in the range of 5,000 to 100,000.

The modified polyvinyl acetal resin used in the present invention is
Substituents with acidic hydrogen atoms have an acid content of 0.1 g / g of resin.
It is a polyvinyl acetal resin modified by being introduced in the range of ˜6 meq and is a resin that is soluble or swellable in an alkaline aqueous solution. The substituent having an acidic hydrogen atom here means the acid dissociation constant (pk
a) is 6 or less, for example, carboxylic acid (-COO
H), and the like sulfonyl urethane (-SO ₂ NHCOO-). If the acid content per 1 g of the resin is less than 0.1 meq, the developability with an alkali developing solution becomes insufficient, and if it is more than 6 meq, abrasion resistance deteriorates. Preferably 0.
It is 5 to 4 meq.

Specific examples of the modified polyvinyl acetal resin used in the present invention include those into which arylsulfonyl urethane as described in British Patent No. 1370316 is introduced, Japanese Patent Application Nos. 60-109122, 60-123863, 60- Polyvinyl acetal resins as described in 198742 are reacted with an intramolecular acid anhydride of an organic polycarboxylic acid, and those into which a component containing a hydroxyl group or a cyano group is further introduced. . A particularly preferable modified polyvinyl acetal resin is represented by the following general formula (V).

[General formula (V)]

However, in the formula, R ₁₀ is an alkyl group which may have a substituent or a hydrogen atom, R ₁₁ is an alkyl group which does not have a substituent, R
₁₂ is an aliphatic or aromatic hydrocarbon group having a carboxylic acid group, R ₁₃ is an aliphatic or aromatic hydrocarbon group having at least one hydroxyl group or nitrile group, and optionally having another substituent Group, n ₁ , n ₂ and n ₃ ,
n ₄ and n ₅ represent mol% of each recurring unit, and are in the following ranges.

n ₁ = 5 to 85, n ₂ = 0 to 60, n ₃ = 0 to 20, n ₄ = 3 to 60, n ₅
Is greater than 0 and less than or equal to 60.

The resin represented by the general formula (V) is obtained by acetalizing polyvinyl alcohol with an aldehyde and further leaving the residual --OH.
It can be obtained by reacting carboxylic acid with an acid anhydride, and further reacting a part of the generated carboxylic acid with a halogen compound having a hydroxyl group or a cyano group. The resin of the general formula (V) is mainly composed of five components, a vinyl acetal component as the first component, a vinyl alcohol component as the second component, an unsubstituted ester component as the third component, and a fourth component as the fourth component. An ester component containing a carboxyl group, and a fifth component is an ester component containing a hydroxyl group or a cyano group, and each component may have at least one structural unit.

The first component, the vinyl acetal component, is obtained by reacting an aliphatic aldehyde that may have a substituent with a vinyl alcohol component, and as the substituent, a carboxyl group, a hydroxyl group, a chloro group, a bromine group, and a tertiary group. Examples thereof include amino group, alkoxyl group, cyano group, nitro group, amide group, ester group, urethane group and ureido group. Specifically, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, pentyl aldehyde, hexyl aldehyde, glyoxylic acid, N, N-dimethylformamide di-n-butyl acetal, bromoacetaldehyde, chloroacetaldehyde, 3-hydroxy-n.
-Butyraldehyde, 3-methoxy-n-butyraldehyde, 3- (dimethylamino) -2,2-dimethylpropionaldehyde, cyanoacetaldehyde and the like are included, but are not limited thereto.

In the third component, the substituent R ₁₁ represents an alkyl substituent having 1 to 10 carbon atoms, and a methyl group and an ethyl group are particularly preferable from the viewpoint of developability.

As the fourth component containing a carboxyl group, R ₁₂ is an aliphatic carboxylic acid or aromatic carboxylic acid group having 1 to 20 carbon atoms, which are mainly succinic anhydride, maleic anhydride,
Other cyclic acid anhydrides are obtained by reacting acid anhydrides such as phthalic anhydride, trimellitic anhydride and cis-4-cyclohexene-1,2-dicarboxylic acid anhydride with residual -OH of polyvinyl acetal. You may use.

Further, R ₁₂ may have a substituent other than the carboxy group. As the substituent, -OH, -C≡N, -Cl, -Br, -NO _2, such as -OR _14, and the like. R ₁₄ is an alkyl group having 1 to 20 carbon atoms which may have a substituent, an aralkyl group or an aryl group, and the substituent is —O.
H, -C≡N, -Cl, -Br, -NO ₂ may be mentioned.

As the fifth component containing a hydroxyl group or a cyano group, R ₁₃ can be obtained by reacting the carboxylic acid in R _{12 of} the fourth component with a halogen compound containing a hydroxyl group or a cyano group to esterify.

Specific examples of R ₁₃ include: However, the present invention is not limited to these.

In the general formula (V), n ₁ is preferably 5 to 85 mol%, particularly preferably 25 to 70 mol%. As the value of n ₁ becomes smaller, the film strength becomes weaker, and as the value of n ₁ becomes larger, other components eventually decrease and adversely affect.

With respect to n ₄ , 3 to 60 mol% is preferable, and 10 to 55 mol% is particularly preferable. When the value of n ₄ is large, the swelling of the exposed portion with the alkali developing solution is large, and when the value of n ₄ is small, it is difficult to develop with the alkali developing solution and the film is removed.

Regarding n _5, it is preferably more than 0 and 60 mol% or less, and particularly preferably more than 0 and 40 mol% or less. As the value of n ₅ increases, other components eventually decrease and adversely affect.

The molecular weight of the modified polyvinyl acetal resin is about 5000 as measured by gel permeation chromatography.
400,000 is suitable and preferably about 50,000 to 300,000.

The polyurethane resin having a carboxyl group and / or the modified polyvinyl acetal resin having a substituent having an acidic hydrogen atom introduced therein may be used alone or in combination. The content of these resins contained in the photosensitive composition is about 50 to 99.5% by weight, preferably about 55 to 95% by weight.

Other resin may be mixed in the photosensitive composition of the present invention in an amount of 50% by weight or less based on the resin. Examples of the mixed resin include polyurethane resin having no carboxyl group, polyvinyl acetal resin having no acidic hydrogen atom, polyamide resin, epoxy resin, acrylic resin, methacrylic resin, polystyrene resin, and novolac type phenol resin. You can

Further, various additives can be further added to the photosensitive composition of the present invention, if necessary. For example, alkyl ethers for improving coating properties (eg ethyl cellulose, methyl cellulose) flexibility of coating film, plasticizer for imparting abrasion resistance (eg tricresidyl phosphate, dimethyl phthalate, dibutyl phthalate, trioctyl phosphate, Tributyl phosphate, tributyl citrate, polyethylene glycol, polypropylene glycol, etc.), pigments such as acridine dye, dianine dye, styryl dye, triphenylmethane dye and phthalocyanine as coloring substances for visualizing the image part of the developer. Other general stabilizers for diazo resins (phosphoric acid, phosphorous acid, pyrophosphoric acid, oxalic acid, boric acid, p-toluenesulfonic acid, benzenesulfonic acid, p-hydroxybenzenesulfonic acid, 2-methoxy-4-) Hydroxy-5-ben Il-benzenesulfonic acid, malic acid, tartaric acid, dipicolinic acid, polyacrylic acid and copolymers thereof, polyvinylphosphonic acid and copolymers thereof, polyvinylsulfonic acid and copolymers thereof, 5-nitronaphthalene-1-phosphonic acid, 4-chlorophenoxymethylphosphonic acid, sodium phenyl-methyl-pyrazolone sulfonate, 2-phosphonobutane tricarboxylic acid-1,2,4,1-phosphonoethane tricarboxylic acid-1,2,2,1-hydroxyethane-1 , 1
-Disulfonic acid, etc.) can be added. The amount of these additives added varies depending on the intended purpose, but generally 0.5 to 30% by weight based on the total solid content of the photosensitive layer.
Is.

The photosensitive composition of the present invention is dissolved in a suitable organic solvent and coated on a support having a hydrophilic surface so that the dry coating weight is 0.5 to 5 g / m ² to obtain a photosensitive lithographic printing plate. it can. The concentration of the photosensitive composition at the time of coating is preferably in the range of 1 to 50% by weight. Examples of the coating solvent used include methyl cellosolve, ethyl cellosolve, 1-methoxy-2-bropanol, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethyl sulfoxide, ethylene dichloride, diclohexanone, dioxane, tetrahydrofuran, etc. Can be mentioned. A mixed solvent of these or a mixed solvent obtained by adding a small amount of water, a solvent such as toluene, which does not dissolve the diazo resin, or the polymer compound to the mixed solvent, is also suitable. When the photosensitive solution dissolved in these solvents is applied and dried, it is desirable to dry at 50 ° C to 120 ° C. As a drying method, the temperature may be lowered at the beginning and pre-dried and then dried at a high temperature, or may be directly dried at a high temperature by selecting an appropriate solvent and concentration.

A lithographic printing plate having a photosensitive layer coated on a support having a hydrophilic surface is exposed with an image and then developed with a developer containing weak alkaline water to obtain a negative relief image with respect to the original image. Suitable light sources for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps,
Strobe, ultraviolet laser beam, etc. can be mentioned. As a developing solution for a photosensitive lithographic printing plate having a photosensitive layer of the present invention, JP-A-51-77401, JP-A-51-80228, and JP-A-53-4420 are known.
No. 2 and JP-A No. 55-52054, organic solvents having a solubility in water of 10% by weight or less at room temperature (benzyl alcohol, ethylene glycol monophenyl ether, etc.) and alkaline agents (triethanol). Amine, monoethanolamine, etc., anionic surfactant (aromatic sulfonate, dialkyl sulfosuccinate, alkyl naphthalene sulfonate, A weak alkaline aqueous solution consisting of branched alkyl sulfate ester salt, etc.), water and, if necessary, an antifouling agent (sodium sulfite, sulfopyrazolone sodium salt, etc.) and a water softener (ethylenediaminetetraacetic acid 4Na, NCH ₂ COONa) ₃ ) Can be done.

As the support having a hydrophilic surface to which the photosensitive composition of the present invention is applied, a hydrophilized aluminum plate is particularly preferable. The surface of the aluminum plate is wire brush grained, brushed with a nylon brush while pouring a slurry of abrasive particles, ball graining, chemical graining, electrolytic graining and a combination of these graining methods. After graining the surface with the performed composite graining, if necessary, anodize with sulfuric acid, phosphoric acid, oxalic acid, boric acid, chromic acid, sulfamic acid or mixed acid of these with direct current or alternating current power source to make aluminum surface. Those provided with a strong passive film are preferable.
Such a passivation film itself makes the surface of aluminum hydrophilic, but if necessary, silicate treatment (sodium silicate, silica) described in U.S. Pat. No. 2,714,066 or U.S. Pat. No. 3,181,461. Acid potassium), potassium fluoride zirconate treatment described in U.S. Pat. No. 2,946,638, phosphomolybdate treatment described in U.S. Pat. No. 3,201247, described in German Patent No. 1091433. Polyacrylic acid treatment, German patent 11
Polyvinylphosphonic acid treatment described in 34093 and British Patent 1230447, phosphonic acid treatment described in JP-B-44-6409, and phytic acid described in U.S. Pat. No. 3,307,951. Treatment, JP-A-58-16
893 and Japanese Patent Laid-Open No. 58-18291, hydrophilic treatment by a composite treatment comprising a hydrophilic organic polymer compound and a divalent metal, or by undercoating a water-soluble polymer having a sulfonic acid group. What carried out is especially preferable. As another hydrophilic treatment method, silicate electrodeposition described in US Pat. No. 3658662 can also be mentioned.

〔The invention's effect〕

According to the present invention, there is provided a photosensitive composition suitable for producing a photosensitive printing plate which is alkali developable and has improved printing durability and inking property. Therefore, it can be widely used as a photosensitive lithographic printing plate to which the composition is applied.

Hereinafter, the present invention will be described in more detail based on examples.

[Reference example]

Synthesis Example 1 125 g of 4,4'-diphenylmethane diisocyanate in a 500 ml three-necked round bottom flask equipped with a condenser and a stirrer.
(0.50 mol) and 67 g (0.50 mol) of 2,2-bis (hydroxymethyl) propionic acid were added and dissolved in 290 ml of dioxane. 1 g of N, N-diethylaniline was added as a catalyst, and the mixture was heated under reflux for 6 hours with stirring. Then, the reaction solution was poured into a solution of water 4 and acetic acid 40 ml with stirring to precipitate a white polymer. This polymer was separated by filtration, washed with water, and dried under vacuum to obtain 185 g of a polymer.

Weight average (polystyrene standard) when molecular weight was measured by gel permeation chromatography (GPC)
It was 28,000. Further, the carboxyl group content measured by titration was 2.47 meq / g.

Furthermore, 40g of this polymer was equipped with a condenser and stirrer.
It was put in a 00 ml three-necked round bottom flask and dissolved with DMF 200 ml. To this solution was added 6.3 g (0.062 mol) of triethylamine and after heating to 80 ° C 7.7 g (0.06 mol) of ethylene bromohydrin.
2 mol) was added dropwise with stirring over 10 minutes. Then, stirring was continued for 2 hours.

After completion of the reaction, the reaction solution was poured into a solution of water 4 and acetic acid 200 ml with stirring to precipitate a white polymer. The polymer was separated by filtration, washed with water, and dried under vacuum to obtain 42 g of a polymer.

It was confirmed by NMR measurement that a hydroxyethyl group had been introduced into the carboxyl group, and the residual carboxyl group content was measured by titration to find that it was 1.21 meq / g (polymer (a)).

Synthetic Examples 2 to 5 Using the diisocyanates and diol compounds shown in Table 1, a polyurethane resin having a carboxyl group was first synthesized in the same manner as in Synthetic Example 1, and then ethylene bromohydrin (A) or ethylene cyano was used. The polyurethane resin of the present invention was synthesized by reacting bromide (B) with a part of the carboxyl groups in the polyurethane resin.

It was confirmed by NMR measurement that a hydroxyethyl group or a cyanoethyl group was introduced into the carboxyl group.
Furthermore, the molecular weight was measured by GPC, and the residual carboxyl group content was measured by titration. The measured carboxyl group content is shown in Table 1.

In the table, A is ethylene bromohydrin and B is ethylene cyanobromide.

All molecular weights are weight average (polystyrene standard)
It was 8,000 to 45,000.

Synthesis Example 6 60 g of polyvinyl butyral (Denka Butyral # 4000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to acetic acid 7
It was dissolved by heating in 20 ml. After further increasing the reaction temperature to 100 ° C,
89.8 g of phthalic anhydride and 60.5 g of sodium acetate were added and the reaction was carried out for 3 hours. After the reaction, this solution was added little by little to 10 solution of methanol water 1: 3 to precipitate a polymer. The solid was vacuum dried to obtain 64.8 g of polymer (f). The acid content was 2.72 meq / g.

Synthesis Example 7 Polyvinyl propional (propional component: 52 mol%, vinyl alcohol component: 48) was placed in the same apparatus as in Synthesis Example 6.
60% (mol%) was dissolved by heating in 720 ml of acetic acid. After further raising the reaction temperature to 100 ° C, 230 g of phthalic anhydride and 60.5 g of sodium acetate
Was added and reacted for 3 hours. After the reaction, this solution was post-treated in the same manner as in Synthesis Example 6 to obtain 61.5 g of polymer (g). The acid content was 2.82 meq / g.

Synthesis Example 8 In the same manner as in Synthesis Example 6, 60 g of polyvinyl formal (Vinilec B-2, manufactured by Chisso) was dissolved in 720 ml of acetic acid. After further raising the reaction temperature to 100 ° C, trimellitic anhydride 132.8
g and 72.0 g of sodium acetate were added and reacted for 4 hours. This solution was post-treated in the same manner as in Synthesis Example 6 to obtain 60.8 g of polymer (h). The acid content was 2.82 meq / g.

Synthesis Example 9 In a three-necked round bottom flask having a capacity of 1, equipped with a thermometer, a reflux condenser and a stirrer, 45 g of the modified polyvinyl butyral (f) synthesized in Synthesis Example 6 was dissolved by heating in 450 ml of N, N-dimethylformamide. . After adjusting the internal temperature to 80 ℃, potassium carbonate
Add 6.91g and add ethylene bromhydrin 6.24g 3
Reacted for hours. After the reaction, this solution was added to water-acetic acid 19: 1 5
The solution was added little by little to precipitate a polymer. By vacuum drying this solid, 38.4 g of polymer (i) was obtained.
Got The acid content was 1.48 meq / g.

Synthesis Example 10 Under the same conditions as in Synthesis Example 9, 6.93 g of propylene bromohydrin was added dropwise instead of ethylene bromohydrin. Post-treatment was carried out in the same manner as in Synthesis Example 9 to obtain 39.8 g of polymer (j). The acid content was 1.37 meq / g.

Synthesis Example 10 Under the same conditions as in Synthesis Example 9, 6.69 g of 3-bromopropionitrile was added dropwise instead of ethylene bromhydrin. Post-treatment was carried out in the same manner as in Synthesis Example 4 to obtain 37.5 g of polymer (k). The acid content was 1.48 meq / g.

Synthesis Example 12 Under the same conditions as in Synthesis Example 9, 17.5 g of 2,5-dibromo-4-hydroxybenzyl bromide was added instead of ethylene bromhydrin. Post-treatment was carried out in the same manner as in Synthesis Example 4 to obtain 40.8 g of Polymer (l). The acid content was 1.75 meq / g.

Synthesis Example 13 45 g of the modified polyvinyl propional (g) synthesized in Synthesis Example 7 was heated and dissolved in 450 ml of N, N-dimethylformamide in the same apparatus as in Synthesis Example 9. After adjusting the internal temperature to 80 ° C, add 7.3 g of potassium carbonate, and add ethylene bromhydrin.
6.55 g was added and reacted for 3 hours. After the reaction, this solution was
A solution of 10: 1 acetic acid 19: 1 was added little by little to precipitate a polymer. The solid was vacuum dried to obtain 41.8 g of polymer (m). The acid content was 1.27 meq / g.

Synthetic Example 14 45 g of the modified polyvinyl formol (h) synthesized in Synthetic Example 8 was placed in the same apparatus as in Synthetic Example 9 with N, N-dimethylformamide.
It was heated to 450 ml and dissolved. After adjusting the internal temperature to 80 ° C, 15.4 g of potassium carbonate was added, and ethylenebromhydrin 14.
0 g was added and reacted for 3 hours. After the reaction, this solution was added little by little to a 10 solution of water-acetic acid 19: 1 to precipitate a polymer. The solid was vacuum dried to obtain 39.4 g of polymer (n). The acid content was 1.20 meq / g.

Examples 1 to 10 and Comparative Examples 1 to 2 An aluminum plate having a thickness of 0.24 mm was grained on its surface using a nylon brush and an aqueous suspension of 400 mesh pumice and then washed well with water. This was immersed in a 10% aqueous solution of sodium hydroxide at 70 ° C. for 60 seconds for etching, washed with running water, neutralized with 20% nitric acid, and then washed with a light emitting device of JP-A-53-67.
Electrochemical surface roughening method described in Japanese Patent No. 507, that is, V _A = 12.7 V,
Using a sinusoidal alternating wave current of V _C = 9.1 V, electrolytic surface roughening treatment was performed in a 1% aqueous nitric acid solution with an electric quantity at the anode of 160 Coulomb / dm ² . Continue to soak in 30% sulfuric acid aqueous solution at 55 ℃
After desmutting for 2 minutes at a thickness of 2.
Anodizing treatment was performed so as to obtain 0 g / m ² . Then 70 ℃
Immersion treatment in a 3% aqueous solution of sodium silicate for 1 minute,
It was washed with water and dried. The aluminum plate obtained as described above was coated with the following photosensitive solution with a wheeler and dried at 80 ° C. for 2 minutes. The coating weight was 2.0 g / m ² .

Photosensitive solution 4- (n-dodecyl (benzenesulfonate 1.0 g polymer a to e and i to n) of a condensate of 4-diazodiphenylamine and formaldehyde Polymers of Synthesis Examples 1 to 5 and 9 to 14 (Table 2) 5.0 g Victoria Pure Blue BOH 0.1 g Malic acid 0.05 g Fluorosurfactant (Table 2) 0.12 g 2-Methoxyethanol 100 g These photosensitive lithographic printing plates were produced by Fuji Photo Film Co., Ltd.
Image exposure for 1 minute from a 1m distance with a PS light manufactured by PS, and a volume ratio of automatic processor 800EB II manufactured by the same company and developer DN-3C manufactured by the same as 1: 2.
Development and gumming treatment were carried out at 25 ° C. for 50 seconds using a (water) diluted solution and a water diluted solution of Gum FN-2 manufactured by the same company at a volume ratio of 1: 1. Next, one week after processing these planographic printing plates, they were applied to a GTO printing machine manufactured by Heidelberg Co., Ltd., and the inking property was examined by the number of prints until the ink was completely transferred to the printing paper. The printing durability was examined by the number of sheets where no The results are summarized in Table 2.

In Table 2, the amounts of fluorine in N-butylperfluorooctanecuronamide ethyl acrylate and N-butylperfluorohexanesulfonamide ethyl acrylate are 49.5% by weight and 44.7% by weight, respectively.

From the results shown in Table 2, it can be seen that the photosensitive lithographic printing plates of Examples 1 to 10 of the present invention have extremely excellent printing durability and inking property. Also, comparing Comparative Examples 1 and 2 with Example 3,
It can be seen that the fluorosurfactant having a low molecular weight and the fluoroaliphatic group-containing monomer having a high ratio have poor inking properties.

Claims (1)

[Claims] 1. A photosensitive composition containing a photosensitive diazo resin, a polymer binder and a fluorine-based surfactant,
The polymer binder is a polyurethane resin having a carboxyl group and / or a modified polyvinyl acetal resin introduced with a substituent having an acidic hydrogen atom, and the fluorine-based surfactant has (i) 3 to 20 carbon atoms. And an acrylate or methacrylate containing 30% by weight or more of fluorine and containing a fluoroaliphatic group in which at least three terminal carbon atoms are completely fluorinated, and (ii) poly (oxyalkylene) acrylate or A copolymer with poly (oxyalkylene) methacrylate, wherein the fluoroaliphatic group-containing acrylate or methacrylate monomer unit is 7 to 40% by weight based on the weight of the copolymer, and the molecular weight of the copolymer is A photosensitive composition, which is 10,000 to 100,000.