JPH0411857B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photosensitive composition, and in particular to a photosensitive composition that is highly sensitive, has excellent chemical resistance and printing durability, and is suitable for a photosensitive lithographic printing plate that can be developed with water or a weakly alkaline aqueous solution. be. Until now, various studies have been conducted on unsaturated polyester resins in which cinnamic acid skeletons are introduced into the side chains or main chains of polymers, and it is well known that they have already been applied as photosensitive resin layers for lithographic printing plates. It is about. However, in conventional photosensitive planographic printing plates that use unsaturated polyester containing a cinnamic acid skeleton, the resin is generally soluble only in organic solvents, so organic solvents are not used to elute and remove non-exposed areas. Main developer must be used,
In addition to being economically disadvantageous, there were also problems in terms of work hygiene and disposal of used developer. In recent years, consideration has been given to developing photosensitive lithographic printing plates that can be developed with water or a weakly alkaline aqueous solution. For example, unsaturated compounds containing an oxymonocarboxylic acid residue derived from an alkylhydroxyalkoxycinnamate starting from oxycinnamic acid and an aromatic hydrocarbon residue having a sulfo group adjacent to an aromatic nucleus in the main chain. A photosensitive material (Japanese Unexamined Patent Application Publication No. 130897/1989) has been proposed that has a resin photosensitive layer and is developable with an alkaline aqueous solution. However, conventional photosensitive lithographic printing plates are
Or, the developability with weakly alkaline aqueous solutions containing no organic solvents, sensitivity, chemical resistance to various chemicals used during lithographic printing, ink receptivity, printing durability, etc. are still insufficient, and further improvements are needed. was desired. In addition, conventionally, a water-developable process consisting of a polyester using a dicarboxylic acid having a sulfo group as a polyester-forming component as a binder resin, and an unsaturated compound having an addition-polymerizable carbon-carbon double bond as a photoreaction initiator. Various photosensitive compositions for resin letterpress printing have been proposed (for example,
-6191, JP-A-49-105888), but these systems basically do not have the property that the binder resin polyester itself crosslinks and becomes insolubilized by photoreaction, so it is difficult to absorb light in an oxygen atmosphere. In the case of irradiation, the sensitivity may be extremely reduced, or a long time may be required for pretreatment under a specific inert gas atmosphere to prevent the effects of trace amounts of oxygen dissolved in the photosensitive layer, or Since the system itself is extremely hydrophilic, it has major drawbacks as a lithographic printing plate material, such as being difficult to accept lithographic printing ink, which is more lipophilic than letterpress ink, even after photocuring. In addition, an ethylenically unsaturated monomer having at least two addition-polymerizable terminal double bonds in a photocrosslinkable polymer having a cinnamic acid group, a cinnamylidene acetic acid group, or a furyl acrylic acid group in the main chain or side chain. There have also been proposed photosensitive compositions for use in dry films or release development, in which a photopolymerization sensitizer is added. (For example, Tokuko Sho 56-12857,
However, it goes without saying that these systems cannot be developed at all with water or a weakly alkaline aqueous solution that does not contain any organic solvent, and the main point of these systems is to improve the plasticizing effect. By adding an ethylenically unsaturated monomer as a liquid substance, the adhesion to the support can be improved or controlled. The present inventors have studied photosensitive compositions improved in this respect, and have previously found a photosensitive composition having a specific aromatic dicarboxylic acid unit, a dicarboxylic acid unit having a sulfonate salt group, and a specific hydrogenated benzene ring. We proposed the use of a photosensitive polyester containing diol units as an essential component in the photosensitive layer.
(Japanese Unexamined Patent Publication No. 56-118345) With the intention of further improving this photosensitive composition, as a result of intensive studies, the present invention has revealed that, in addition to the above-mentioned essential components, (B) at least two addition-polymerizable infinitesimals. The present inventors have discovered that the desired objective can be achieved by using a combination of an ethylenically unsaturated compound having a saturated double bond and (C) a photopolymerization initiator, and have completed the present invention. An object of the present invention is to provide a photosensitive composition that has extremely high sensitivity and can be developed even with a weak alkaline aqueous solution containing no water or organic solvent. It can be used as a printing plate in the lithographic printing method, which prints using the most minute balance between hydrophilicity and lipophilicity, and it also has excellent ink receptivity, chemical resistance, and printing durability. An object of the present invention is to provide a photosensitive composition with excellent properties. Therefore, the object of the present invention is to at least
(A): (a) General formula () (In the formula, m and n represent the numbers 0 or 1, and at least one is 1.) An aromatic dicarboxylic acid unit represented by (b) a dicarboxylic acid unit having a sulfonate salt group,
and (c) general formula () (In the formula,

[Formula] represents a hydrogenated benzene ring, R ¹ and R ² represent an alkylene group having 2 to 4 carbon atoms, R ³ and R ⁴ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, r and s represent numbers from 0 to 3, and t represents a number of 0 or 1); (B): at least two addition-polymerizable terminal unsaturated diol units; This can be easily achieved using a photosensitive composition characterized by containing an ethylenically unsaturated compound having a double bond and (c) a photopolymerization initiator. The present invention will be explained in detail below. (A) Photocrosslinkable polyester of the present invention comprises (a) an aromatic dicarboxylic acid unit represented by the above general formula (), (b) a dicarboxylic acid unit having a sulfonate salt group, preferably a sulfonate salt group. and (c) a diol unit represented by the above general formula () as essential components. The aromatic dicarboxylic acid unit represented by the general formula () is, for example, p-phenylene diacrylic acid, m-phenylene diacrylic acid, p-carboxycinnamic acid, m-carboxycinnamic acid, or an alkyl ester thereof. derived from derivatives such as Especially when considering the sensitivity, the general formula ()
Preferably, m=n=1. The amount of such aromatic dicarboxylic acid units in the photocrosslinkable polyester is usually 5 to 45 mol%, particularly 15 to 40 mol%.
A mole % range is preferred. (b) The dicarboxylic acid unit having a sulfonate salt group is, for example, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, or derivatives thereof such as alkyl esters or hydroxyalkyl esters, 3-sodium sulfoisophthalic acid, or derivatives thereof such as alkyl esters and hydroxyalkyl esters Sulfophthalic acid, 3-potassium sulfophthalic acid, 4-sodium sulfophthalic acid, 4-potassium sulfophthalic acid, or derivatives thereof such as alkyl esters and hydroxyalkyl esters, 2-sodium sulfophthalate acid,
2-potassium sulfoterephthalic acid or derivatives thereof such as alkyl esters and hydroxyalkyl esters, α-sodium sulfosuccinic acid, β-sodium sulfoadipic acid, 2,
It is derived from 5-disodium sulfoadipic acid or its alkyl esters or hydroxyalkyl esters, preferably dimethyl 5-sodium sulfoisophthalate, dibutyl 2-sodium sulfoterephthalate, and the like. The dicarboxylic acid unit having such a sulfonate salt group is 5 mol% in the photocrosslinkable polyester.
It is sufficient if the content is above. However, as the content increases, the adhesion to the support and the ink receptivity of highly lipophilic inks for lithographic printing tend to decrease.
It is preferable to use it in a range of 35 mol%. The above (a) aromatic dicarboxylic acid unit and (b) dicarboxylic acid unit having a sulfonate salt group are:
They constitute the dicarboxylic acid component of the photocrosslinkable polyester of the present invention, but considering sensitivity and developability, the ratio of these (a) units to (b) units is 1:0.1 to 10.
(molar ratio), particularly preferably 1:0.25 to 3 (molar ratio). Further, the diol unit represented by the general formula () is, for example, 1,4-bis(β-hydroxyethoxy)cyclohexane, 1,4-bis(2-
Hydroxypropoxy) cyclohexane, cyclohexanediol or derivatives thereof, hydrogenated bisphenol F, hydrogenated bisphenol A, or derivatives obtained by adding ethylene oxide or propylene oxide to the hydroxyl group thereof. When considering the chemical resistance and printing durability of the obtained polymer, in the general formula () above,

[Formula] preferably has a high degree of hydrogenation, and is particularly preferably a cyclohexane ring. Furthermore, in consideration of the ink receptivity of the resulting polymer, R ¹ and R ² preferably have either a linear or branched alkylene group. In the present invention, (b) is further used as a diol unit.
Those containing aliphatic diol units are preferred.
Such aliphatic diol units are, for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, neopentyl glycol, 2,2-diethyltrimethylene glycol, 2,2-dipropyltrimethylene Derived from linear or branched aliphatic diols such as glycol, 2-ethyl-2-propyltrimethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol . In particular, in consideration of water solubility, chemical resistance, etc. of the resulting photocrosslinkable polyester, aliphatic diols having an ether bond such as diethylene glycol, triethylene glycol, and tetraethylene glycol are preferred. The usage ratio of (c) the hydrogenated benzene ring-containing diol unit represented by the general formula () and (d) the aliphatic diol unit is determined by considering the balance between ink receptivity and developability. c)
The ratio of the unit to the unit (d) is preferably 1:0.2 to 5 (molar ratio). The photocrosslinkable polyester of the present invention can be prepared using the above-mentioned components (a) to (c) or (a) to (d) by a well-known method, for example, the method described in U.S. Pat. No. 3,622,320. It can be easily manufactured. That is, an ester derivative of an aromatic dicarboxylic acid represented by the general formula (), an ester derivative of a dicarboxylic acid having a sulfonate salt group,
At least one diol component among the hydrogenated benzene ring-containing diols represented by the general formula (), with other well-known dicarboxylic acid ester derivatives as a constituent component of the dicarboxylic acid unit, if necessary. and optionally an aliphatic diol as constituent components of the diol unit, heat-dissolved, add a titanium-based catalyst to perform a transesterification reaction, and gradually reduce the pressure and raise the temperature to remove the excess. It can be easily produced by distilling out of the reaction system the diol component and the diol component produced as the polycondensation reaction progresses. In the present invention, reduced viscosity (0.25 g/dlN,
N-dimethylformamide solution, 30℃) is 0.1
A photocrosslinkable polyester having a molecular weight of 1.5 to 1.5, particularly 0.2 to 0.8 is preferable from the viewpoint of improving sensitivity without reducing developability. (B) of the present invention is an ethylenically unsaturated compound having at least two addition polymerizable terminal unsaturated double bonds. It refers to a monomer or polymer that undergoes a reaction to harden and become substantially insolubilized. Monomer here includes dimers, trimers, and oligomers in addition to monomers in the narrow sense. It also includes. Examples of the ethylenically unsaturated monomer having an addition-polymerizable terminal unsaturated double bond include esters of unsaturated carboxylic acids and aliphatic polyhydroxy compounds, and esters of unsaturated carboxylic acids and aromatic polyhydroxy compounds. , unsaturated carboxylic acids and polyhydric carboxylic acids and the aforementioned aliphatic polyhydroxy compounds,
Examples include esters obtained by an esterification reaction with a polyhydric hydroxy compound such as an aromatic polyhydroxy compound, or further modified esters. Specific examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, and the like. Examples of aliphatic polyhydroxy compounds include dihydric compounds such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, neopentyl glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, and 1,2-butanediol. Examples include alcohol, trihydric alcohols such as trimethylolethane, trimethylolpropane, and glycerol, tetrahydric or higher alcohols such as pentaerythritol and tripentaerythritol, and polyhydric hydroxycarboxylic acids such as dihydroxymaleic acid. Examples of aromatic polyhydroxy compounds include hydroquinone, resorcinol, catechol, pyrogallol, and the like. Examples of polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, trimellitic acid, pyromellitic acid, benzophenone dicarboxylic acid, maleic acid, fumaric acid, malonic acid, glutaric acid, adipic acid, and sebacic acid. , tetrahydrophthalic acid, etc. Specific examples of esters of aliphatic polyhydroxy compounds and unsaturated carboxylic acids include ethylene glycol diacrylate, triethylene glycol diacrylate, tetramethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and pentaerythritol. Acrylic acid esters such as diacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol octaacrylate, glycerol diacrylate, triethylene glycol dimethacrylate, tetramethylene glycol Dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, dipentaerythritol dimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate, tripenta Erythritol octamethacrylate, ethylene glycol dimethacrylate,
Methacrylic acid esters such as 1,2-butanediol dimethacrylate and sorbitol tetramethacrylate, ethylene glycol diitaconate,
Propylene glycol diitaconate, 1,2-
Itaconic acid esters such as butanediol itaconate, tetramethylene glycol diitaconate, pentaerythritol triitaconate, crotonic acid esters such as ethylene glycol dicrotonate, diethylene glycol dicrotonate, pentaerythritol tetracrotonate, ethylene glycol dimaleate , triethylene glycol dimaleate, pentaerythritol dimaleate, and other maleic acid esters. Examples of esters of aromatic polyhydroxy compounds and unsaturated carboxylic acids include hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate, and pyrogallol triacrylate. The ester obtained by the esterification reaction of an unsaturated carboxylic acid with a polyvalent carboxylic acid and a polyvalent hydroxy compound is not necessarily a single product, but typical examples are shown in Table 1. Z in the table represents an acryloyl group or a methacryloyl group.

[Table] Other examples of compounds having ethylenically unsaturated double bonds that can be used in the present invention include acrylamides such as ethylenebisacrylamide and hexamethylenebisacrylamide, and methacrylamides such as ethylenebismethacrylamide and hexamethylenebismethacrylamide. , diallyl phthalate,
Examples include allyl ester acids such as diallyl malonate, diallyl fumarate, and triallyl isocyanurate, and vinyl-containing compounds such as divinyl adipate, divinyl phthalate, and ethylene glycol divinyl ether. Examples of the ethylenically unsaturated monomer having a modified addition-polymerizable terminal unsaturated double bond include monomers having a free carboxyl group described in Japanese Patent Application No. 56-210920. They can be prepared by reacting (meth)acrylates containing hydroxyalkyl groups with acid anhydrides of dibasic carboxylic acids. Examples of (meth)acrylates containing a hydroxyalkyl group include trimethylolethane diacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, Polyvalent esters such as pentaerythritol triacrylate, pentaerythritol trimethacrylate, and dipentaerythritol tetraacrylate can be mentioned. (meta) with these hydroxyalkyl groups
Examples of the acid anhydride for reacting with acrylates include succinic anhydride, maleic anhydride, itaconic anhydride, phthalic anhydride, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride. A (meth)acrylate compound having a carboxyl group is prepared by a half-esterification reaction between the (meth)acrylate having a hydroxyalkyl group and the acid anhydride. It is preferable to heat the mixture in the presence of a so-called thermal polymerization inhibitor in the absence of a solvent or in the presence of a catalyst such as pyridine, tertiary amine, sulfuric acid, p-toluenesulfonic acid, etc., if necessary. Benzene, toluene, methyl ethyl ketone, dioxane, etc. are useful as the reaction solvent. Considering the developability of these ethylenically unsaturated compounds having at least two addition-polymerizable terminal unsaturated double bonds in a weakly alkaline aqueous solution that does not contain any water or organic solvent, alcoholic Particularly suitable are those containing a hydroxyl group, a phenolic hydroxyl group, or a free carboxyl group, such as (meth)acrylic acid esters such as pentaerythritol acrylate and their succinic anhydride modified products. The unsaturated compound is the photocrosslinkable polyester.
It is used in a range of 5 to 200 parts by weight per 100 parts by weight, preferably in a range of 10 to 100 parts by weight. (C) The photopolymerization initiator of the present invention generates radicals by irradiation with actinic rays, and the above-mentioned (B) photopolymerization initiator can be used to add-polymerize the ethylenically unsaturated compound having at least two addition-polymerizable terminal unsaturated double bonds. It is something that brings about a reaction. The photopolymerization initiator that can be used in the present invention needs to be capable of efficiently expressing the photopolymerization reaction without inhibiting the photocrosslinking reaction of the photocrosslinkable polyester described above. Also,
It is essential to irradiate actinic rays to draw images on photosensitive lithographic printing plates, but the light sources used in this process usually emit light energy with a wavelength of 340 nm or more, and light in this wavelength range is essential. The polymerization reaction must be carried out efficiently. Furthermore, although the photocrosslinking reaction of the photocrosslinkable polyester described above occurs sufficiently with polyester alone, in order to achieve practical so-called sensitivity, a sensitizer as described below is usually added to the photosensitive layer for use. It will be done. This sensitizer is also a chemically designed product that takes into consideration the light energy distribution of the light source used for image drawing and can efficiently convert that energy into the expression of a photocrosslinking reaction. As described above, the photopolymerization initiator (C) in the present invention sufficiently coexists with the light energy distribution of these light sources and the light absorption of the sensitizer added to promote the photocrosslinking reaction, and thereby performs photocrosslinking. In parallel with the photocrosslinking reaction of the polyester, (B) a strong photopolymerization reaction of the ethylenically unsaturated compound having at least two addition-polymerizable terminal unsaturated double bonds. Must be an initiator. In view of this point, the present inventors investigated and found that benzyl-
It has been found that so-called complex initiators such as a combination of 4,4'-bis(dimethylamino)benzophenone are particularly effective. The complex initiator referred to here is
When a mixture of specific compounds is used as a photopolymerization reaction initiator in a photopolymerization reaction, a mutual activation effect appears, and a unique mixture that exhibits an effect that cannot even be predicted when each compound is used alone can be created. means. Examples of this composite initiator include
Combinations of compounds such as benzoin, benzoin methyl ether, benzyl, and fluorenone and 4,4'-bis(dialkylamino)benzophenone disclosed in No. 20067, benzyl and fluorenone, or substitutions disclosed in JP-A No. 57-10605. Benzyl groups with groups and general formulas (In the formula, R ⁵ , R ⁶ , R ⁷ and R ⁸ represent an alkyl group, and u and v represent 0, 1, or 2.)
A combination with p-dialkylaminophenyl ketones represented by the general formula disclosed in JP-A-55-95865 (In the formula, R ⁹ represents an alkyl group, Y is -O-,
A divalent atom or atomic group selected from -S-, -Se-, -CH=CH-, and -NR ¹⁰ -, which forms a heteroaromatic ring B together with a trivalent nitrogen atom, and R ¹⁰
represents a hydrogen atom or an alkyl group, and even if ring A is a benzene ring or naphthalene ring which may have a substituent, it is fused with ring B. ) A combination of p-dialkylaminostilbene derivative represented by
General formula disclosed in 56-118339 (In the formula, R ¹¹ represents an alkyl group, R ¹² represents a hydrogen atom or an alkyl group, and Ring A is a benzene ring or a naphthalene ring which may have a substituent, and is fused with a thiazole ring. are doing.)
Combination of p-dialkylaminocinnamylidene derivative represented by and hexaarylbiimidazole, Japanese Patent Application No. 56-128406 and Japanese Patent Application No. 56-139484
The general formula disclosed in (In the formula, R ¹³ and R ¹⁴ represent an alkyl group,
Ring A and Ring B represent a benzene ring or a naphthalene ring which may have a substituent, X represents an anion, and w represents 0 or 1. ) or thiapyrylium salt, and
general formula (In the formula, R ¹⁵ , R ¹⁶ and R ¹⁷ are an alkyl group or an aryl group which may have a substituent, or an alkenyl group, a piperidino group, -NR ₂ -, -OR,
-S (Here, R represents a hydrogen atom or an alkyl group.)
, at least one of which represents a mono-, di- or trihalogen-substituted methyl group. ), and any of them can be suitably used.
In particular, benzoin, benzoin methyl ether,
A combination of a compound such as benzyl or fluorenone and 4,4'-bis(dialkylamino)benzophenone is preferred. The amount of each specific compound constituting this composite initiator may range from 0.1% by weight to 0.1% by weight in the photosensitive layer.
It is advantageous to use 20% by weight, preferably in the range of 1% to 10% by weight. Furthermore, it is also a very useful means to add (D) a resin containing a phenolic hydroxyl group in addition to these essential components. Addition of this resin containing phenolic hydroxyl groups significantly improves water resistance when unexposed. Such resins include so-called phenolic resins synthesized from phenols and aldehydes or ketones by addition condensation reaction, poly-hydroxyphenyl resins such as poly-p-hydroxystyrene, and other substituted resins. Examples include poly-hydroxyphenyl resins containing groups. In addition, the phenolic hydroxyl groups in these resins can be partially converted into esters by reacting with acid chlorides such as cinnamic acid chloride and (meth)acrylic acid chloride, or with acid anhydrides such as succinic anhydride and phthalic anhydride. Resins that have been modified to partially contain free carboxylic acid residues by reacting with substances are also well used. The resin containing a phenolic hydroxyl group is used in an amount of 1 to 500 parts by weight, preferably 5 to 150 parts by weight, per 100 parts by weight of the photocrosslinkable polyester.
A range of parts by weight is preferred. The photosensitive composition of the present invention can be prepared, for example, by dissolving the photocrosslinkable polyester in a solvent, and then adding an ethylenically unsaturated compound having at least two addition-polymerizable terminal unsaturated double bonds and a photopolymerization initiator to the photosensitive composition. It is easily produced by dissolving it in a solution. Suitable solvents vary depending on the composition and molecular weight of the photocrosslinkable polyester, but when the content of dicarboxylic acid units having sulfonate salt groups is low, suitable solvents include methylene chloride, chloroform, trichloroethane, chlorobenzene, dichlorobenzene, etc. Chlorinated solvents, alcoholic solvents such as furfuryl alcohol, tetrahydrofurfuryl alcohol, benzyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monophenyl ether,
Ethylene glycol and ether derivatives of diethylene glycol such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, ester solvents such as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, ethyl acetate, dimethyl formamide, N-methyl pyrrolidone,
Examples include nitrogen-containing solvents such as nitroethane and nitrobenzene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, 4-methyl-4-methoxy-2-pentanone, and dimethyl sulfoxide. On the other hand, when the content of dicarboxylic acid units having sulfonate salt groups is high, not only water but also keto alcohols such as diacetone alcohol, methyl lactate, ethyl lactate, n-butyl lactate, i-butyl lactate, etc. and hydroxy group-containing fatty acid esters are also effective. The photosensitive composition of the present invention may contain various known additives in addition to the above-mentioned components, if necessary. For example, it may contain additives such as other resins, colorants, plasticizers, stabilizers, sensitizers, etc. within the range that does not inhibit the developability with water or weakly alkaline aqueous solutions. These additives may be added when preparing the photosensitive composition. Here, the sensitizer is a substance that promotes the photocrosslinking reaction of the photocrosslinkable polyester itself, and includes conventionally known sensitizers such as benzanthrone, 6,11-dichlorobenzanthrone, 11-
Chloro-hydroxybenzanthrone, 1-carboethoxy-2-keto-3-methyl-3-aza-
Benzanthrone derivatives such as 1,9-benzanthrone, 1,8-dichloroanthraquinone, 1,
Quinones such as 8-dimethoxyanthraquinone and 1,2-benzanthraquinone, 5-nitroacenaphthene, 2-nitrofluorenone, 2,7-dinitrofluorenone, 1-nitronaphthalene, 1,
Mono- or polynitro compounds such as 5-dinitronaphthalene, 2-dibenzoylmethylene-3-
Methyl-β-naphthothiazoline, 2-henzoylmethylene-3-methyl-β-naphthothiazoline,
2-di(2-furoyl)methylene-3-methyl-
Naphthothiazoline derivatives such as β-naphthothiazoline are preferred. Examples of the stabilizer include known thermal polymerization inhibitors, and suitable examples include hydroquinone, methylhydroquinone, p-methoxyphenol, pyrogallol, catechol, 2,6-di-t-butyl-p-cresol, and β-naphthol. It can be used for The photosensitive composition of the present invention can be applied to polyethylene terephthalate films, printing zinc plates,
Aluminum plates for printing, silicon wafers,
It can be applied by well-known coating methods such as dip coating, coating rod, spinner coating, and spray coating onto an object appropriately selected depending on the purpose of use, such as a chromium-deposited glass plate. . For example, by applying a photosensitive composition to the surface of a support, printing materials for letterpress printing, gravure printing, etc., photoresists, etc. can be formed. For example, when used in a photosensitive lithographic printing plate, a printing aluminum plate whose surface has been anodized is suitable as a support, especially anodized in a bath of phosphoric acid or a mixed acid bath of phosphoric acid and sulfuric acid. This aluminum plate is particularly preferred because it has good adhesion to the photocrosslinkable polyester polymer of the present invention. The photosensitive composition thus prepared for use is exposed to light in an overlapping manner according to conventional methods, or a pattern or image is drawn by irradiating it with an electron beam or the like. After that, by developing with water or a weakly alkaline aqueous solution, a corresponding pattern, image, etc. can be formed on the support. especially,
The present invention is extremely useful compared to conventional systems because it allows good development without containing an organic solvent in the developer. Of course, even an alkaline aqueous solution containing a small amount of an organic solvent having an affinity for water shows extremely excellent developability. The present invention has been described in detail above, and the photosensitive composition of the present invention can be developed with water or a weakly alkaline aqueous solution with extremely high sensitivity.
Moreover, when used in photosensitive lithographic printing plates, the printing plates have excellent abrasion resistance, chemical resistance, and printing durability, and also have excellent properties such as extremely good acceptance of highly oleophilic lithographic printing inks. have. Next, the present invention will be explained in more detail with reference to Examples, but the present invention includes the following:
The present invention is not limited to the following examples. Production example 1 Diethyl p-phenylene diacrylate 32.88g
(120 mmol), 23.68 g (80 mmol) of dimethyl 5-sodium sulfoisophthalate, 1,4-bis(2-hydroxyethoxy)-cyclohexane
20.40g (100mmol) and 42.0g (280mmol) of triethylene glycol were placed in a 200ml three-necked flask, and 5% of butyl orthotitanate was added as a catalyst.
Add 10ml of ethanol solution and under nitrogen gas supply.
Gradually raise the temperature while stirring at a rotation speed of 200 rpm.
The transesterification reaction was carried out at 210°C for about 1 hour, and the produced ethanol and methanol were distilled off. Next, the stirring rotation speed was lowered to 100 rpm, and the system was gradually reduced in pressure over 1 hour. After reaching a reduced pressure of 1 mmHg, the bath temperature was quickly raised to 250°C, and the reaction was carried out under these conditions for about 30 minutes. Excess diol and diol produced as the reaction progressed were distilled off.
After cooling, the three-necked flask was broken to obtain a transparent photocrosslinkable polyester. The reduced viscosity (ηsp/C, 0.25 g/dl N,N-dimethylformamide solution, 30°C) of the obtained polyester was 0.45. Production example 2 Diethyl p-phenylene diacrylate 32.88g
(120 mmol), 23.68 g (80 mmol) of dimethyl 5-sodium sulfoisophthalate, 1,4-bis(2-hydroxyethoxy)-cyclohexane
12.24g (60mmol) and triethylene glycol
42.00 g (280 mmol) was charged into a 200 ml three-necked flask, and a transesterification reaction was carried out in the same manner as in Production Example 1. Then, after reducing the pressure to 1 mmHg at 210°C,
The bath temperature was quickly raised to 240°C, and the reaction was carried out under these conditions for 45 minutes. The reduced viscosity of the obtained polyester (same as in Production Example 1) was 0.54. Production Examples 3 to 6 Several kinds of photocrosslinkable polyesters were obtained under the conditions shown in Table 1 below.

【table】

[Table] Example 1 and Comparative Example 1 4 of the photocrosslinkable polyester obtained in Production Example 1
A wt% ethylene glycol monomethyl ether solution was prepared, and 2-dibenzoylmethylene-3-methyl-β-naphthothiazoline (hereinafter referred to as
DBT) was added in an amount of 5% by weight based on the polyester. Furthermore, here is pentaerythritol triacrylate (“Viscoat” manufactured by Osaka Organic Chemical Industry Co., Ltd.).
300") was added to the polyester in an amount of 40% by weight, and benzyl and Michler's ketone as photoreaction initiators were added in an amount of 2.8% by weight based on the polyester, and after confirming that they were uniformly dissolved, Eisen Victoria Pour Blue-BOH ( CI No. 42595) (manufactured by Hodogaya Chemical Co., Ltd.) was added to the polyester in an amount of 1% by weight and filtered to obtain a photosensitive solution (1). This photosensitive solution (1) was grained and further placed in a phosphoric acid bath. A photosensitive lithographic printing plate (1) was obtained by applying the coating to an aluminum plate anodized with a whirler.This printing plate was passed through a step wedge with an optical density step of 0.15, and a 3kw high-pressure mercury lamp was used to coat the plate at a distance of 500 m from a distance of 1 m. I exposed it to light for a few seconds.I developed it by rubbing it gently with a soft cloth for a few seconds under tap water.
It was insolubilized up to the 5th stage. When the resulting image was loaded with a conventional lithographic development ink, the ink receptivity was very good and only a few sheets of paper were required to roll up the image area on the printing press. Furthermore, when a chemical resistance test was conducted on the image obtained by exposure and development using a petroleum solvent and an alcohol solvent, no change was observed in the image area. As a comparative example, a photosensitive solution (2) without the addition of pentaerythritol acrylate, benzyl, and Michler's ketone was prepared and coated on the aluminum plate with a white coating to obtain a photosensitive lithographic printing plate (2). It took more than a dozen sheets of paper to roll up the image section. In addition, we conducted an abrasion resistance test using a petroleum solvent for both photosensitive lithographic printing plates (1) and (2), and observed the image area after abrasion using a scanning electron microscope. It was confirmed that this method is superior to (2) and has been improved. Examples 2 to 3 Photosensitive solutions (3) and (4) having the compositions shown in Table 2 below were prepared, and photosensitive planographic printing plates (3) and (4) were prepared in the same manner as in Example 1.
I got it.

[Table] The obtained printing plates were exposed in the same manner as in Example 1.
When developed, it was found that the 8th and 9th stages were insolubilized. A printing test was carried out using the printing plate obtained using the photosensitive liquid (3), which was installed in a printing machine, and it showed excellent ink receptivity, and even after printing 150,000 sheets, good prints were obtained, making it an extremely excellent product. Demonstrated printability. Examples 4 and 5 Photosensitive solutions (5) and (6) having the compositions shown in Table 3 below were prepared using the photocrosslinkable polyester obtained in Production Example 2, and photosensitive lithographic printing was carried out in the same manner as in Example 1. Versions (5) and (6) were obtained.

[Table] Photosensitive lithographic printing plates (5) and (6) were exposed in the same manner as in Example 1, and developed using an alkaline aqueous solution containing 5.5% sodium silicate and 1.2% sodium hydroxide. The non-image areas were removed very cleanly, showing excellent developability, and were insolubilized up to the 6th stage in each case. When these printing plates were subjected to an abrasion resistance test, they exhibited excellent abrasion resistance as in Example 2, and also had extremely excellent ink receptivity. In addition, the photosensitive planographic printing plate (5) obtained in Example 4
After storing it in a room at 60° C. and 90% humidity for 3 days, it was exposed and developed in the same manner, and the non-image areas were completely removed, yielding a printing plate with good image areas.
When this printing plate was subjected to an abrasion resistance test, the printing plate showed excellent abrasion resistance and also had extremely good ink receptivity. Examples 6 and 7 Photosensitive solutions (7) and (8) having the compositions shown in Table 4 below were prepared using the photocrosslinkable polyester obtained in Production Example 2, and photosensitive planographic plates were prepared in the same manner as in Example 1. Print version(7)
and (8) were obtained.

[Table] Photosensitive lithographic printing plates (7) and (8) were exposed in the same manner as in Example 1, and developed using an alkaline aqueous solution containing 5.5% sodium silicate and 1.2% sodium hydroxide. The non-image area was removed very cleanly, and printing plate (7) was insolubilized up to the 6th stage and printing plate (8) up to the 4th stage. Both the abrasion resistance test and the ink receptivity of these printing plates were excellent. Examples 8 to 11 Using the photocrosslinkable polyester obtained in Production Example 2, photosensitive solutions (9) to (12) having the compositions shown in Table 5 below were prepared, and photosensitive lithographic printing was carried out in the same manner as in Example 1. Versions (9) to (12) were obtained.

【table】

[Table] Optical density difference for photosensitive lithographic printing plates (9) to (12)
Exposure for 60 seconds from a distance of 1 m using a 1 kW metal halide lamp through a 0.15 step wedge.
Similar to Examples 4 and 5, sodium silicate 5.5
The resulting image was developed using an alkaline aqueous solution containing 1.2% sodium hydroxide, and the resulting image was subjected to a chemical resistance test using petroleum-based solvents and alcohol-based solvents, as well as an abrasion resistance test, and the processed image area was scanned. The results of observation using an electron microscope are shown in Table 6 below.

【table】

[Table] The ink receptivity of the image area of these printing plates was also very good, and only several sheets of paper were required to roll up the image area on the printing press. Examples 12 to 16 Using the photocrosslinkable polyester obtained in Production Example 1, photosensitive liquids (13) to 12 having the compositions shown in Table 7 below were prepared.
(17) was prepared, and photosensitive printing plates (13) to (17) were obtained in the same manner as in Example 1.

【table】

[Table] Photosensitive lithographic printing plates (13) to (17) were exposed in the same manner as in Example 1, and 5.5% sodium silicate was added.
and developed using an alkaline aqueous solution containing 1.2% sodium hydroxide. The resulting image area had good chemical resistance, abrasion resistance, and ink receptivity. Furthermore, the water resistance of the unexposed area was also extremely good. Examples 17 to 20 Using the photocrosslinkable polyesters obtained in Production Examples 3 to 6, photosensitive solutions (18) to (21) having the compositions shown in Table 8 below were prepared in the same manner as in Example 1, Photosensitive planographic printing plates (18) to (21) were obtained.

[Table] Printing plates (18) to (21) were exposed and developed in exactly the same manner as in Example 1, and the chemical resistance, abrasion resistance, and ink receptivity of the image areas obtained were measured. The results were obtained.

Claims (1)

[Claims] 1 At least (A): (a) General formula () (In the formula, m and n represent the numbers 0 or 1, and at least one is 1.) An aromatic dicarboxylic acid unit represented by (b) a dicarboxylic acid unit having a sulfonate salt group,
and (c) general formula () (In the formula, [Formula] represents a hydrogenated benzene ring, R ¹ and R ² represent an alkylene group having 2 to 4 carbon atoms, and R ³ and R ⁴ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. (B): at least two addition-polymerizable polyesters; A photosensitive composition comprising: an ethylenically unsaturated compound having a terminal unsaturated double bond; and (c): a photopolymerization initiator. 2 The photocrosslinkable polyester (A) has the following formula: (a) General formula () (In the formula, m and n represent the numbers 0 or 1, and at least one is 1.) An aromatic dicarboxylic acid unit represented by (b) an aromatic dicarboxylic acid unit having a sulfonate salt group, (c ) General formula () (In the formula, [Formula] represents a hydrogenated benzene ring, R ¹ and R ² represent an alkylene group having 2 to 4 carbon atoms, and R ³ and R ⁴ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. (d) aliphatic diol unit; and (d) aliphatic diol unit. The photosensitive composition described in . 3. The photosensitive composition according to claim 1, wherein the photopolymerization initiator (c) is a composite initiator. 4. The photosensitive composition according to claim 1, wherein the photosensitive layer further contains a resin having a D phenolic hydroxyl group.