JPH0820778B2 - Electrophotographic lithographic printing plate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic lithographic printing plate precursor prepared by an electrophotographic method, and more particularly to a binder for forming a photoconductive layer of the lithographic printing plate precursor. Regarding improvement of resin.

(Prior Art) At present, various types of offset master plates for direct plate making have been proposed and put into practical use. Among them, photoconductive particles such as zinc oxide and a binder resin are mainly used on a conductive support. In a photoreceptor provided with a photoconductive layer, a highly lipophilic toner image is formed on the surface of the photoreceptor through a normal electrophotographic process, and then the surface is treated with a desensitizing solution called an etchant to make it non-sensitive. A technique for obtaining an offset original plate by selectively making an image portion hydrophilic is widely used.

In order to obtain a good printed matter, first, on the offset original plate,
The original image is faithfully copied, the surface of the photoconductor is easily compatible with the desensitizing solution, and the non-image area is sufficiently hydrophilic, and at the same time has water resistance. Should not be removed, and it should be well compatible with fountain solution, and the hydrophilicity of the non-image area should be sufficiently maintained so that stains do not occur even when the number of printed sheets increases.

It is already known that the ratio of zinc oxide to the binder resin in the photoconductive layer affects these performances. For example, if the ratio of the binder resin to the zinc oxide particles of the photoconductive layer is reduced, the desensitizing property of the photoconductive layer surface is improved and the background stain is reduced, but on the other hand, the internal cohesive force of the photoconductive layer itself is reduced. And the printing durability is reduced due to insufficient mechanical strength. On the contrary, if the ratio of the binder resin is increased, the printing durability is improved,
Soil pollution increases. Needless to say, the background stain is a phenomenon related to the quality of the desensitizing property of the surface of the photoconductive layer, but the desensitizing property of the surface of the photoconductive layer is a phenomenon of the zinc oxide and the binder resin in the photoconductive layer. It has become clear that not only the ratio but also the type of binder resin greatly affects.

Known resins have long been known, for example, silicone resin (Japanese Patent Publication Sho 34-6670), styrene-butadiene resin (Japanese Patent Publication 35-1950), alkyd resin, maleic acid resin, polyamide (Japanese Patent Publication 35-11219), vinyl acetate resin ( Japanese Patent Publication 41
-2425), vinyl acetate copolymer (Japanese Patent Publication No. 41-2426), acrylic resin (Japanese Patent Publication No. 35-11216), acrylate copolymer (eg Japanese Patent Publication No. 35-11219, Japanese Patent Publication No. 36-8510, Japanese Patent Publication No. 4).
1-13946 etc.) are known. However, in electrophotographic photosensitive materials using these resins, 1) the photoconductive layer has a low charging property, 2) the quality of the image portion of the copied image (particularly halftone dot reproducibility / resolution) is poor, and 3) exposure. Low sensitivity 4) Desensitization is not performed even when desensitized for use as an offset master. Therefore, background stain occurs on printed matter when offset printing is performed. 5) Photosensitive layer film strength is insufficient. If the offset printing is performed, the photosensitive layer may be detached, and the number of printed sheets cannot be increased. 6) The image quality is easily affected by the environment (for example, high temperature and high humidity) at the time of creating a copy image. It was

In particular, as the offset original plate, as described above, the occurrence of scumming due to insufficient desensitizing property is a big problem, and in order to improve this, various development of zinc oxide binder resin for improving desensitizing property has been studied. Is coming. For example, Japanese Examination Shokoku 50
-31011, Mw1.8-10 × 10 ⁴ obtained by copolymerizing (meth) acrylate-based monomer with other monomer in the presence of fumaric acid.
In which a resin having a Tg of 10 to 80 ° C. and a copolymer composed of a (meth) acrylate-based monomer and a monomer other than fumaric acid are used in combination. In JP-A-53-54027, at least a carboxylic acid group is formed from an ester bond. A method using a terpolymer containing a (meth) acrylic acid ester having a substituent having 7 atoms apart, JP-A-54-20735 and JP-A-57-202544 discloses acrylic acid and hydroxyethyl (meth). ) Using quaternary or quaternary copolymers containing acrylates
In 58-68046, one using a terpolymer containing a (meth) acrylic acid ester having an alkyl group having 6 to 12 carbon atoms as a substituent and a vinyl monomer containing a carboxylic acid is a desensitizing agent for the photoconductive layer. It is described that it is effective in improving sex. However, even with these resins that are said to be effective in improving the desensitizing property, when actually evaluated, the background stain and the printing durability were insufficient.

Further, as a binder resin, a resin containing a functional group capable of generating a hydrophilic group by decomposition has been studied, for example, a resin containing a functional group capable of generating a hydroxy group by decomposition (Japanese Patent Laid-Open No. 62- 195684, JP-A-62-210475
No. JP-A-62-210476) or those containing a functional group capable of generating a carboxyl group by decomposition (JP-A-62-21269)
Etc. are disclosed.

These resins are hydrolyzed or hydrogenolyzed by a desensitizing solution or a fountain solution used for printing to produce a hydrophilic group, and when these are used as a binder resin of a lithographic printing plate precursor, they have a hydrophilic property. Various problems (such as deterioration of smoothness, deterioration of electrophotographic characteristics, etc.) which are considered to be caused by strong interaction between the hydrophilic group and the surface of the photoconductive zinc oxide particles when a resin containing the group itself is used. ) Can be avoided, and the hydrophilicity of the non-image area to be hydrophilized by the desensitizing liquid is further enhanced by the hydrophilic group generated by decomposition in the resin. It is described that the hydrophilicity of the area becomes clear, prevents printing ink from adhering to the non-image area during printing, and as a result, it is possible to print a large number of prints of clear image quality without background smear. .

(Problems to be Solved by the Invention) However, even if these resins are used, background fouling and printing durability are still unsatisfactory, and when a resin containing a hydrophilic group-forming functional group as described above is used. However, when the content is increased in order to further improve the hydrophilicity in the non-image area, the hydrophilic group generated by the decomposition increases the hydrophilicity and becomes water-soluble, so that the sustainability is particularly high. It turned out that there was a problem in sex.

Therefore, the effect by the hydrophilicity of the non-image portion is further improved,
The emergence of a technology that further improves sustainability is desired.

More specifically, even if the content of the resin containing a hydrophilic group-forming functional group as described above in the entire binder resin is reduced, the effect of improving hydrophilicity can be maintained unchanged or is improved, or The advent of a technique capable of printing a large number of printed matter with clear image quality without background stains is desired even when printing conditions such as a large-sized printing machine or fluctuations in printing pressure become severe.

(Means for Solving Problems) The above problem is that at least one photoconductive zinc oxide and at least one carboxyl group are generated on the conductive support by decomposition represented by the following general formula (VI). A resin (A) each containing a copolymerization component containing at least one functional group and a copolymerization component containing at least one functional group that undergoes a curing reaction with heat and / or light; To be solved by an electrophotographic lithographic printing plate precursor provided with a photoconductive layer obtained by coating a liquid containing toluene and a crosslinking agent capable of chemically reacting with a functional group which undergoes a curing reaction by heat and / or light. Was found.

General formula (VI) X ': -O-, -CO-, -COO-, -OCO-, -CON
(D ₁ )-, an aromatic group or a heterocyclic group (provided that d ₁ is a hydrogen atom, a hydrocarbon group or-(Y'-W) in formula (VI))
Y ': a carbon-carbon bond which connects the linking group X'and the linking group W and which may pass through a hetero atom (provided that the hetero atom is an oxygen atom, a sulfur atom or a nitrogen atom), W: a functional group which decomposes to form a carboxy group, a ₁ , a ₂ : may be the same or different, and is a hydrogen atom, a halogen atom, a cyano group or an optionally substituted carbon atom 1 to
7, a hydrocarbon group.

In the present invention, at least a part of the binder resin of the photoconductive layer of the lithographic printing plate precursor contains a resin containing at least one functional group that decomposes to generate at least one carboxyl group, and It is characterized in that a crosslinking agent that crosslinks coexists. As a result, the lithographic printing plate precursor according to the present invention reproduces a copy image faithful to the original image, and since the non-image area has good hydrophilicity, scumming does not occur, and the smoothness and electrostatic properties of the photoconductive layer are reduced. It has the advantages of good characteristics and excellent printing durability.

Further, the lithographic printing plate precursor of the invention is characterized by being unaffected by the environment at the time of plate making processing and being excellent in preservability before processing.

Hereinafter, a functional group used in the present invention, which decomposes to form at least one carboxyl group (hereinafter simply referred to as
(Also referred to as a carboxyl group-forming functional group) will be described in detail.

The carboxyl group-forming functional group of the present invention generates a carboxyl group by decomposition, but the number of carboxyl groups generated from one functional group may be one or two or more.

According to one preferred embodiment of the present invention, the carboxyl group-forming functional group-containing resin has the general formula (I) [-COO-L
₁ ] A resin containing at least one functional group represented by the formula [ ₁ ].

In the general formula (I) [-COO-L ₁ ], L ₁ is -N = CH-Q ₁ , -NH-OH, Represents

However, R ₁ and R ₂ may be the same or different from each other,
Represents a hydrogen atom or a resin group, X represents an aromatic group, Z is a hydrogen atom, a halogen atom, a trihalomethyl group, an alkyl _{group, -CH, -NO 2, -SO 2} R 1 '( where R ₁ ′
Represents a hydrocarbon group), —COOR ₂ ′ (wherein R ₂ ′ represents a hydrocarbon group), or —O—R ₃ ′ (wherein R ₃ ′ represents a hydrocarbon group), n, m represents 0, 1, or 2.

R ₃ , R ₄ and R _{5, which} may be the same or different, each represents a hydrocarbon group or —O—R ₄ ′ (provided that R ₄ ′ represents a hydrocarbon group), M represents Si, Represents Sn or Ti.

Q ₁ and Q ₂ each represent a hydrocarbon group.

Y ₁ represents an oxygen atom or a sulfur atom, R ₆ , R ₇ and R ₈ may be the same or different and each represents a hydrogen atom or an aliphatic group, and p represents an integer of 3 or 4. Y ₂ represents an organic residue forming a cyclic imide group.

The functional group of the general formula [-COO-L ₁ ] generates a carboxyl group by decomposition, and will be described in more detail below.

L ₁ is In the case of representing, R ₁ and R ₂ may be the same or different from each other, preferably a hydrogen atom, or an optionally substituted linear or branched alkyl group having 1 to 12 carbon atoms (for example, a methyl group). , Ethyl group,
Propyl group, chloromethyl group, dichloromethyl group, trichloromethyl group, trifluoromethyl group, butyl group, hexyl group, octyl group, decyl group, hydroxyethyl group, 3-chloropropyl group, etc., and X is preferably Represents a phenyl group or naphthyl group which may be substituted (eg, phenyl group, methylphenyl group, chlorophenyl group, dimethylphenyl group, chloromethylphenyl group, naphthyl group, etc.), Z is preferably a hydrogen atom, a halogen atom (eg, Chlorine atom, fluorine atom, etc.), trihalomethyl group (eg trichloromethyl group, trifluoromethyl group etc.), linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted (eg, methyl group, Chloromethyl group, dichloromethyl group, ethyl group, propyl group, butyl group, hexyl group, tetrafluoro Ethyl, octyl, cyanoethyl, chloroethyl group, _{etc.), - CN, -NO 2,} -SO 2 R
₁ '[R _1' represents an aliphatic group (e.g. an optionally substituted alkyl group having 1 to 12 carbon atoms: for example, methyl group, ethyl group,
Propyl group, butyl group, chloroethyl group, pentyl group,
Aralkyl group having 7 to 12 carbon atoms and optionally substituted such as octyl group: specifically, benzyl group, phenethyl group, chlorobenzyl group, methoxybenzyl group, chlorophenethyl group, methylphenethyl group, etc.) or aromatic group ( For example, a phenyl group or naphthyl group which may contain a substituent: specifically, a phenyl group, a chlorophenyl group, a dichlorophenyl group, a methylphenyl group, a methoxyphenyl group, an acetylphenyl group, an acetamidophenyl group, a methoxycarbonylphenyl group, Naphthyl group, etc.], -CO
OR ₂ ′ (R ₂ ′ has the same meaning as R ₁ ′ above) or —O—R ₃ ′
(R ₃ ′ has the same meaning as R ₁ ′ above). n and m represent 0, 1 or 2.

Is L ₁ described above When the case of is described more specifically, the following examples of substituents can be given.

For example, β, β, β-trichloroethyl group, β, β,
β- trifluoroethyl group, a hexafluoro -i- _{propyl, -CH 2 CF 2 CF 2 n} 'H group (n' represents 1 to 5), 2-cyanoethyl, 2-nitroethyl group, 2-methane Sulfonylethyl group, 2-ethanesulfonylethyl group, 2
-Butanesulfonylethyl group, benzenesulfonylethyl group, 4-nitrobenzenesulfonylethyl group, 4-cyanobenzenesulfonylethyl group, 4-methylbenzenesulfonylethyl group, benzyl group which may contain a substituent (for example, benzyl group, methoxy group) A benzyl group, a trimethylbenzyl group, a pentamethylbenzyl group, a nitrobenzyl group, etc.), a phenacyl group which may contain a substituent (for example, phenacyl group, bromophenacyl group, etc.), and a phenyl group which may contain a substituent (for example, Phenyl, nitrophenyl, cyanophenyl, methanesulfonylphenyl, trifluoromethylphenyl, dinitrophenyl, etc.).

Also L ₁ In the case of representing, R ₃ , R ₄ and R ₅ may be the same or different from each other, and preferably an optionally substituted aliphatic group having 1 to 18 carbon atoms [wherein the aliphatic group is an alkyl group or an alkenyl group ，
It represents an aralkyl group or an alicyclic group, and examples of the substituent include a halogen atom, -CN group, -OH group, -O-Q '(Q'
Are alkyl groups, aralkyl groups, alicyclic groups, aryl groups, etc.), and optionally substituted aromatic groups having 6 to 18 carbon atoms (eg, phenyl group, tolyl group, chlorophenyl group, methoxyphenyl). Group, acetamidophenyl group, naphthyl group, etc.), or —O—R ₄ ′ [R ₄ ′ is an optionally substituted alkyl group having 1 to 12 carbon atoms, or an optionally substituted alkenyl group having 2 to 12 carbon atoms. Represents an optionally substituted aralkyl group having 7 to 12 carbon atoms, an optionally substituted alicyclic group having 5 to 18 carbon atoms, and an optionally substituted aryl group having 6 to 18 carbon atoms].

M represents each atom of Si, Ti, or Sn, and more preferably Si
Represents an atom. The L ₁ is -N = CH-Q ₁ or In the case of representing, each of Q ₁ and Q ₂ is preferably an optionally substituted aliphatic group having 1 to 18 carbon atoms (as the aliphatic group, an alkyl group, an alkenyl group, an aralkyl group, an alicyclic group Examples of the substituent include a halogen atom, CN
And an optionally substituted aryl group having 6 to 18 carbon atoms (for example, a phenyl group, a methoxyphenyl group, a tolyl group, a chlorophenyl group, and a naphthyl group).

L ₁ is In the formula, Y ₁ represents an oxygen atom or a sulfur atom. R ₆ , R ₇ and R ₈ may be the same or different from each other,
Preferably, a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group,
Decyl group, dodecyl group, octadecyl group, chloroethyl group, methoxyethyl group, methoxypropyl group, etc.), optionally substituted alicyclic group (eg, cyclopentyl group, cyclohexyl group, etc.), optionally substituted carbon number 7-12
Aralkyl group (eg, benzyl group, phenethyl group, chlorobenzyl group, methoxybenzyl group, etc.) or optionally substituted aromatic group (eg, phenyl group, naphthyl group, chlorophenyl group, tolyl group, methoxyphenyl group, methoxy group Carbonylphenyl group, dichlorophenyl group, etc.) or —O—R ₅ ′ (R ₅ ′ represents a hydrocarbon group,
Specifically, it represents the same substituents as the above-mentioned hydrocarbon groups of R ₆ , R ₇ and R ₈ ).

 P represents an integer of 3 or 4.

L ₁ is In the case of representing, Y ₂ represents an organic residue forming a cyclic imide group. Preferably, the compound represented by the general formula (II) or (II)
Represents an organic residue represented by I).

General formula (II) General formula (III) In formula (II), R ₉ and R ₁₀ may be the same or different, and each is a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, etc.), or an optionally substituted alkyl group having 1 to 18 carbon atoms ( For example, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group,
Hexadecyl, octadecyl, 2-chloroethyl, 2,
-Methoxyethyl group, 2-cyanoethyl group, 3-chloropropyl group, 2- (methanesulfonyl) ethyl group, 2- (ethoxyoxy) ethyl group, etc., an optionally substituted aralkyl group having 7 to 12 carbon atoms (For example, benzyl group, phenethyl group, 3-phenylpropyl group, methylbenzyl group, dimethylbenzyl group, methoxybenzyl group, chlorobenzyl group, bromobenzyl group, etc.), alkenyl having 3 to 18 carbon atoms which may be substituted. Group (for example, allyl group, 3-methyl-
2-propenyl group, 2-hexenyl group, 4-propyl-2-
Pentenyl group, 12-octadecenyl group, etc.), -S-
R ₆ ′ (R ₆ ′ has the same meaning as the alkyl group, aralkyl group and alkenyl group of R ₉ or R ₁₀ ) and optionally substituted aryl group (eg, phenyl group, tolyl group, chlorophenyl group, bromo group) phenyl group, a methoxyphenyl group, ethoxyphenyl group, an ethoxycarbonyl phenyl group, etc.), or -NHR ₇ '(R _7' represents the same content as the R ₆ '). Further, R ₉ and R ₁₀ may represent a residue forming a ring (for example, a 5- or 6-membered monocyclic ring (for example, cyclopentyl ring, cyclohexyl ring), or a 5- or 6-membered bicyclo ring (for example, Bicycloheptane ring, bicycloheptene ring, bicyclooctane ring, bicyclooctene ring, etc.), and these rings may be substituted, and the substituents are the same as those described above for R ₉ and R ₁₀ . Including things. ) Q represents 2 or 3 integer.

In the formula (III), R ₁₁ and R ₁₂ may be the same or different and have the same contents as R ₉ and R ₁₀ . Further, R ₁₁ and R ₁₂ may represent an organic residue which is linked to form an aromatic ring (eg, benzene ring, naphthalene ring, etc.).

In another preferred embodiment of the present invention, the compound represented by the general formula (I
V) - it is a resin containing at least one functional group represented by [CO-L _2].

In the general formula (IV) [-CO-L ₂ ], L ₂ is Represents Here, R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ each represent a hydrogen atom or an aliphatic group.

The aliphatic group preferably has the same contents as the substituents of R ₆ , R ₇ and R ₈ . Further, R ₁₄ and R ₁₅ and R ₁₆ and R ₁₇ represent an organic residue which may combine to form a condensed ring.
Preferably, a 5- to 6-membered monocyclic ring (eg, cyclopentyl ring, cyclohexyl ring, etc.), 5- to 12-membered aromatic ring (eg, benzene ring, naphthalene ring, thiophene ring,
Pyrrole ring, pyran ring, quinoline ring, etc.).
Further, another preferred embodiment of the present invention is a resin containing at least one oxazolone ring represented by the following general formula (V).

General formula (V) In the general formula (V), R ₁₈ and R ₁₉ may be the same or different from each other and each represents a hydrogen atom or a hydrocarbon group, or R ₁₈ and R ₁₉ together form a ring. Good.

Preferably, R ₁₈ and R ₁₉ may be the same or different from each other, and each is a hydrogen atom, or an optionally substituted linear or branched alkyl group having 1 to 12 carbon atoms (for example, methyl group, ethyl group). Group, propyl group, butyl group, hexyl group, 2-
Chloroethyl group, 2-methoxyethyl group, 2-methoxycarbonylethyl group, 3-hydroxypropyl group, etc.), optionally substituted aralkyl group having 7 to 12 carbon atoms (eg, benzyl group, 4-chlorobenzyl group, 4 -Acetamidobenzyl group, phenethyl group, 4-methoxybenzyl group, etc.),
Optionally substituted alkenyl group having 2 to 12 carbon atoms (for example, ethylene group, allyl group, isopropenyl group, butenyl group, hexenyl group, etc.), optionally substituted 5
7-membered alicyclic group (eg, cyclopentyl group, cyclohexyl group, chlorocyclohexyl group, etc.), optionally substituted aromatic group (eg, phenyl group, chlorophenyl group,
Methoxyphenyl group, acetamidophenyl group, methylphenyl group, dichlorophenyl group, nitrophenyl group,
Naphthyl group, butylphenyl group, dimethylphenyl group, etc.) or R ₁₈ and R ₁₉ together form a ring (eg,
(A tetramethylene group, a pentamethylene group, a hexamethylene group, etc.) may be formed.

The resin containing at least one functional group selected from the group of functional groups represented by the general formulas (I) to (IV) used in the present invention is a resin represented by the general formula [] by reacting a carboxyl group contained in a polymer. -COO-L ₁ ] or [-CO-L ₂ ] is converted into a functional group, a method by a so-called polymer reaction, or a functional group of the general formula [-COO-L ₁ ] or [-CO-L ₂ ] Is obtained by a method of forming a polymer by a polymerization reaction of one or more monomers containing one or more of, or the monomer and another monomer copolymerizable therewith.

These methods are described, for example, in “New Experimental Chemistry Course, Volume 14, Synthesis and Reaction of Organic Compounds [V]”, 2535, edited by The Chemical Society of Japan.
Pages (published by Maruzen Co., Ltd.), Yoshio Iwakura: Keisuke Kurita, "Reactive Polymers", page 170 (published by Kodansha), etc.

The general formula [-COO-L ₁ ] or [-CO-
For the reason that the functional group of L ₂ ] can be arbitrarily adjusted or that impurities are not mixed, the general formula [-COO-L ₁ ]
Alternatively, a method of producing a monomer containing one or more functional groups of [—CO-L ₂ ] by a polymerization reaction is preferable. Specifically, a carboxylic acid containing a polymerizable double bond or an acid halide thereof is converted to a carboxyl group of the general formula [-COO-L ₁ ] or [- After conversion into a functional group of [CO-L ₂ ], polymerization can be carried out to produce the compound.

The oxazolone ring-containing resin represented by the general formula (V) may be one or more monomers containing the oxazolone ring, or the monomer and another monomer copolymerizable therewith. To a polymer by a polymerization reaction of

The oxazolone ring-containing monomer can be produced by a dehydration ring-closing reaction of N-acylloyl-α-amino acids having a polymerizable unsaturated bond. In particular,
Iwakura Yoshio. It can be produced by the method described in the literature in Keiretsu Kurita, “Reactive Polymers”, Chapter 3 (published by Kodansha).

Other monomers that can be copolymerized with these monomers include:
For example, aliphatic vinyl carboxylates such as vinyl acetate, vinyl propionate, vinyl acetate, allyl acetate, allyl propionate or allyl esters, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, etc. Unsaturated carboxylic acid esters or amides, styrene derivatives such as styrene, vinyltoluene, α-methylstyrene, α-olefins, acrylonitrile, methacrylonitrile, and vinyl group-substituted heterocyclic compounds such as N-vinylpyrrolidone Etc.

As described above, the copolymerization component containing the functional groups of the general formulas (I) to (V) used in the method for producing a desired resin by the polymerization reaction is represented by the following general formula (VI).

General formula (VI) In formula (VI), X'is -O-, -CO-, -COO-, -OCO.
_{-, - CON (d 1)} -, an aromatic group or a heterocyclic group _{[where, d 1, d 2, d} 3, d 4 are each a hydrogen atom, a hydrocarbon group,
Or Y'-W] in the formula (VI), Y'represents a carbon-carbon bond which connects the bonding group X'and the bonding group [W] and which may be bonded via a hetero atom (hetero atom). Means an oxygen atom, a sulfur atom, a nitrogen atom), for example CH = CH, -O-, -S-, -COO -, - CONH -, - SO 2 -, - SO 2 NH -, - NHCOO-,
-NHCONH-, etc., which are composed of a single or a combination of bonding units (provided that b ₃ , b ₄ and b ₅ are the same or different, respectively, a hydrogen atom, a hydrocarbon group or In formula (VI),-(Y'-W) is represented.) W represents a functional group represented by formulas (I) to (V).

a ₁ and a ₂ may be the same or different and each represents a hydrogen atom, a halogen atom (eg, chlorine atom, bromine atom, etc.), a cyano group, a hydrocarbon group (eg, methyl group, ethyl group, propyl group, butyl group, 1 to 12 carbon atoms which may be substituted, such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, hexyloxycarbonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, butoxycarbonylmethyl group.
Alkyl group, benzyl group, phenethyl group and other aralkyl groups, phenyl group, tolyl group, xylyl group, chlorophenyl group, and other aryl groups), or a substituent containing -W group in formula (VI) Which represents an alkyl group having 1 to 18 carbon atoms, an alkenyl group, an aralkyl group, an alicyclic group or an aromatic group).

Further, the [-X'-Y'-] bonding residue in the formula (VI) is You may directly connect a part and -W.

W represents the symbol content represented by the general formulas (I) to (V).

Specific examples of the functional groups [W group in formula (VI)] represented by formulas (I) to (V) of the present invention are described below. However, the scope of the present invention is not limited to these.

(12) -COOCH ₂ CF ₃ (48) -COOCH ₂ OCH _{3 (50) -COOC (C 6 H} 5) 3 (51) -COOCH (C 6 H 5) 2 Further, as a copolymerization component containing at least one functional group which causes a curing reaction by heat and / or light in the resin (A) of the present invention, -OH group, -SH group, -NHR group (R is a carbon number 1
~ 8 alkyl group (eg, methyl group, ethyl group, propyl group, butyl group, hexyl group, etc.) or aryl group (eg, phenyl group, tolyl group, methoxyphenyl group, butylphenyl group, etc.), etc. It is a component containing a substituent having at least one dissociative hydrogen atom, or a component containing an epoxy group, a thioepoxy group, or the like. The proportion of the copolymer component containing these polar groups is preferably 1 to 20% by weight, and more preferably 3 to 10% by weight in the resin of the present invention.

The polar group-containing copolymer component may be, for example, any vinyl compound containing the polar group, which is copolymerizable with the general formula (VI). Specific examples include derivatives contained in the substituents of the same compounds as those described in the general formula (VI).

Furthermore, the resin of the present invention has the above general formula (I) to
In addition to the monomer containing (V) and the monomer containing any of the polar groups, a monomer other than these may be contained as a copolymerization component.

For example, α-olefins, vinyl alkanoates or allyl esters, acrylonitrile, methacrylonitrile, vinyl ethers, acrylamides, methacrylamides, styrenes, heterocyclic vinyls (for example, vinylpyrrolidone, vinylpyridine, vinylimidazole, vinyl). Thiophene, vinyl imidazoline, vinyl pyrazole, vinyl dioxane, vinyl quinoline, vinyl thiazole, vinyl oxazine, etc.) and the like. Particularly, vinyl acetate, allyl acetate, acrylonitrile, methacrylonitrile, styrenes and the like are preferable components from the viewpoint of improving the film strength.

In the present invention, as the cross-linking agent used, compounds which are usually used as cross-linking agents can be used.
Specifically, use the compounds described in "Crosslinking Agent Handbook" edited by Shinzo Yamashita and Tosuke Kaneko, published by Taisei Publishing Co., Ltd. (1981), edited by the Society of Polymer Science, "Polymer Data Handbook, Basic Edition, Baifukan (1986)". You can

For example, silane coupling such as organic silane compounds (for example, vinyltrimethoxysilane, vinyltributoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, etc. Agents, etc.), polyisocyanate compounds (for example, toluylene diisocyanate, O-toluylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate, hexamethylene diisocyanate, isophorone) Diisocyanates, high molecular weight polyisocyanates, etc., polyol compounds (eg 1,4-butanediol, polyoxypropylene glycol, polyoxyalkylene glycol, 1,1,1-trimethylol) Buropan etc.), polyamine compounds (e.g., ethylenediamine, .gamma.-hydroxypropyl ethylenediamine, phenylenediamine,
Hexamethylenediamine, N-aminoethylpiperazine, modified aliphatic polyamines, etc., polyepoxy group-containing compounds and epoxy resins (for example, "New Epoxy Resin" by Hiroshi Kakiuchi, Shokoido (1985), Kuniyuki Hashimoto, "Epoxy" Resin "Compounds described in Nikkan Kogyo Shimbun (1969)", melamine resin (eg, Ichiro Miwa, Hideo Matsunaga, "Uria Melamine Resin" Nikkan Kogyo Shimbun (1969), etc.) Compounds), poly (meth) acrylate compounds (eg Shin Okawara, Takeo Saegusa, Toshinobu Higashimura, "Oligomer" Kodansha (1976), Eizo Omori "Functional Acrylic Resin" Techno System (1985), etc. Specific examples of the compounds described include polyethylene glycol diacrylate, neopentyl glycol diacrylate, and 1,6-hexa Diacrylate, trimethylolpropane triacrylate, pentaerythritol polyacrylate, bisphenol A-
Diglycidyl ether diacrylate, oligoester acrylate: their methacrylates, etc.).

The binder resin of the present invention is cross-linked after being coated with the photosensitive layer-forming material toluene. In order to carry out the cross-linking, for example, it is preferable that the drying condition is set to a high temperature and / or a long time, or the coating solvent is dried and then further heat-treated. For example, the treatment is performed at 60 ° C to 120 ° C for 5 to 120 minutes. When the above reaction accelerator is used in combination, the treatment can be performed under milder conditions.

Further, the cross-linking should be carried out at least with the resin of the present invention, but it may also be carried out with another resin.

The resin of the present invention is preferably a resin that is hardly soluble or insoluble in acidic and alkaline aqueous solutions when a carboxyl group-forming functional group produces a carboxyl group by decomposition.

The amount of the crosslinking agent present in the resin is 0.1 to 30% by weight,
Particularly, 0.5 to 20% by weight is preferable.

Conventionally known resins can be used together with the resin used in the present invention. Examples thereof include silicone resins, alkyd resins, vinyl acetate resins, polyester resins, styrene-butanediene resins, acrylic resins, etc. as described above, and specific examples are Ryuji Kurita and Jiro Ishiwatari, Polymers,
Volume 17, p. 278 (1968), Harumi Miyamoto, Hidehiko Takei, Imaging, 1973 (No.8) p.

The lithographic printing plate precursor of the present invention is 10 to 60 parts by weight of the binder resin described above with respect to 100 parts by weight of photoconductive zinc,
It is preferably used in a proportion of 15 to 40 parts by weight.

When a conventional resin containing a carboxyl group itself is used from the beginning, the viscosity of a dispersion of zinc oxide and a binder resin becomes high, and even if applied, the smoothness of the photoconductive layer is significantly deteriorated, and the film The strength was not sufficient, and the electrophotographic characteristics were not satisfactory. Even if an original plate having sufficient smoothness could be produced, stains were generated during printing. Furthermore, even when the carboxyl group in the resin is adjusted to produce an original plate with good image quality of the copied image and image quality of the printed matter,
When the environment becomes low temperature / low humidity or high temperature / high humidity during copy image creation (plate making process) (especially in high temperature / high humidity)
In addition, the image quality of the copied image was deteriorated due to the occurrence of background fog, a decrease in density of the image portion, the occurrence of thin lines and skipped characters.

These things are because the interaction between the carboxyl group in the binder resin and the photoconductive zinc oxide particle surface is strong, so that the resin adsorption amount on the particle surface increases, and as a result, the desensitizing solution or fountain solution Even if the familiarity is impaired or the carboxyl group in the binder resin can be adjusted appropriately for the zinc oxide particles, the hydrophilic atmosphere at the interface between the carboxyl group in the resin and the zinc oxide particles Is significantly changed when exposed to low temperature / low humidity or high temperature / high humidity, and it is presumed that electrophotographic characteristics such as surface potential and dark decay after charging are deteriorated.

The resin used in the present invention and a known resin can be mixed at any ratio, but the content of the carboxyl group-forming functional group-containing resin in the total amount of the resin is about 1 to 90% by weight. Is appropriate.

If the content in the total amount of resin is less than 1% by weight, the resulting lithographic printing plate precursor has insufficient hydrophilicity due to desensitizing treatment with a desensitizing solution / fountain solution, and stains during printing. Occurs.

On the other hand, when it is more than 90% by weight, the image forming property during copying is not good.

The resin containing at least one functional group capable of forming a carboxyl group according to the present invention is a resin which is hydrolyzed or hydrolyzed by a desensitizing solution or a fountain solution used during printing to form a carboxyl group.

Therefore, when the resin is used as the binder resin of the lithographic printing plate precursor, the hydrophilicity of the non-image area which is hydrophilized by the desensitizing solution is further enhanced by the carboxyl group generated in the resin. The lipophilicity of the image area and the hydrophilicity of the non-image area become clear, and the printing ink is prevented from adhering to the non-image area during printing. As a result, it becomes possible to print a large number of clear printed matter with clear image quality, compared with the conventional lithographic original plate using a resin.

Furthermore, the resin of the present invention contains a cross-linking agent that causes a cross-linking reaction, and a cross-linking reaction occurs in the process of forming the photoconductive layer or in the process of heating and / or light irradiation before the etching treatment, resulting in a polymer. A bridge is formed between them.
Etching treatment and dampening water during printing on the printing machine
The carboxyl group-containing resin produced by decomposition becomes hydrophilic, and when the content is large, it becomes water-soluble.

However, since the resin of the present invention has a crosslinked structure, its solubility in water is significantly reduced while maintaining its hydrophilicity, and it becomes insoluble or insoluble.

Therefore, the hydrophilicity of the non-image area is further enhanced by the carboxyl group generated in the resin, and the durability is improved.

More specifically, even if the amount of the functional group-containing resin contained in the entire binder resin is reduced, the effect of improving hydrophilicity can be maintained unchanged, or the printing machine can be enlarged or the printing pressure can be increased. Even when the printing conditions such as fluctuations in the print quality become severe, it is possible to print a large number of prints with clear image quality without scumming.

In the present invention, various dyes can be used together as a spectral sensitizer, if necessary. For example, Harumi Miyamoto, Hidehiko Takei, Imaging 1973 (No.8), page 12, CJ Young, etc., RCA
Review 15 , 469 (1954), Kyohei Kiyota, Journal of the Institute of Electrical Communication, J 63-C (No2), 97 (1980) Yuji Harasaki, etc., Journal of Industrial Chemistry 66 78 and 188 (1963), Tadaaki Tani, Japan Journal of the Society 35, 2
08 (1972) and other general reference carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, phthalein dyes, polymethine dyes (for example,
Oxonol dye, merocyanine dye, cyanine dye,
Rhodocyanine dyes, styryl dyes, etc.), phthalocyanine dyes (which may contain a metal) and the like.

More specifically, examples of those mainly using a carbonium dye, a triphenylmethane dye, a xanthene dye, and a phthalein dye are described in JP-B-51-452 and JP-A-50-9.
0334, JP-A-50-114227, JP-A-53-39130, JP-A-53-82353, U.S. Pat.No. 3,052,540, U.S. Pat.No. 4,0
And those described in JP-A-57-16456.

As polymethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes and rhodacyanine dyes, F.
M. Harmmer `` The Cyanine Dyes and Related Compound
s '' and the like can be used, and more specifically, U.S. Pat.No. 3,047,384, U.S. Pat.No.3,110,591,
U.S. Patent 3,121,008, U.S. Patent 3,125,447, U.S. Patent 3,128,179, U.S. Patent 3,132,942, U.S. Patent 3,622,317, U.K. Patent 1,226,892, U.K. Patent 1,
No. 309,274, UK Patent No. 1,405,898, JP-B-48-7814
And the dyes described in JP-B-55-18892.

Further, as a polymethine dye for spectrally sensitizing the near-infrared to infrared light region having a long wavelength of 700 nm or more, JP-A-47-840, JP-A-47-44180, JP-B-51-41061, Sho 49-5034,
JP-A-49-45122, JP-A-57-46245, JP-A-56-35141
No., JP-A-57-157254, JP-A-61-26044, JP-A-61-26044
27551, U.S. Pat.No. 3,619,154, U.S. Pat.No. 4,175,95
No. 6, "Research Disclosure", 1982, 216, Nos. 117-11
Those described on page 8 and the like can be mentioned. The photoconductor of the present invention is excellent in that the performance thereof hardly changes depending on the sensitizing dye even when various sensitizing dyes are used in combination. Furthermore, if necessary, various conventionally known additives for electrophotographic photosensitive layers such as chemical sensitizers can be used in combination. For example, the above-mentioned review article: Imaging 1973 (No. 8), page 12, etc. review electron-accepting compounds (eg halogen, benzoquinone, chloranil, acid anhydrides, organic carboxylic acids, etc.), Hiroshi Komon, et al. Development and Practical Use of Photoconductive Materials and Photoconductors "Chapters 4 to 6: Review of Japanese Science Information Co., Ltd. (1986), polyarylalkane compounds, hindered phenol compounds, p-phenylene Examples thereof include diamine compounds.

The addition amount of these various additives is not particularly limited, but is usually 0.0001 to 2.0 parts by weight with respect to 100 parts by weight of the photoconductor.

The thickness of the photoconductive layer is preferably 1 to 100 μ, particularly 10 to 50 μ.

The photoconductive layer according to the present invention can be provided on a conventionally known support. Generally speaking, the support of the electrophotographic photosensitive layer is preferably conductive, and as the conductive support, for example, a substrate such as metal, paper or plastic sheet is impregnated with a low resistance substance as in the conventional case. Conductivity-treated by subjecting the substrate to one or more, at least one layer is coated for the purpose of imparting conductivity to the front and back surfaces (the surface opposite to the surface on which the photosensitive layer is provided) and further preventing curling, and the support described above. Having a water-resistant adhesive layer on its surface, having at least one precoat layer as needed on the surface layer of the support, and laminating a conductive electroconductive plastic substrate on which Al or the like has been vapor-deposited on paper Things etc. can be used.

Specifically, as an example of a conductive substrate or a conductive material, Yukio Sakamoto, Electrophotography, 14, (No1), p2 ~ 11 (1975),
Hiroyuki Moriga, “Chemistry of Introductory Special Papers” Polymer Publishing Association (197
5), MF Hoover, J. Macromol. Sci. Chem, A-4 (6), No.
Those described on pages 1327 to 1417 (1970) and the like are used.

(Examples) The present invention is illustrated below by examples.

Example 1 and Comparative Examples AC A mixed solution of 47 g of butyl methacrylate, 13 g of 2-hydroxyethyl methacrylate, 40 g of the monomer [A] corresponding to the copolymer component of the present invention and 200 g of toluene was used under a nitrogen stream 70.
After heating to a temperature of ° C, 1.5 g of 2,2'-azobisisobutyronitrile (AIBN) was added and reacted for 8 hours. The weight average molecular weight of the obtained copolymer [1] was 48,000.

Then, 25 g of this copolymer as the solid content and [ethyl methacrylate / acrylic acid (98.5 / 1.5) weight ratio]
Copolymer (weight average molecular weight 45000) 15g, zinc oxide 200g,
Rose Bengal 0.05g, succinic anhydride 0.01g and toluene
300 g of the mixture was dispersed in a ball mill for 2 hours. Next, 6 g of hexamethylene diisocyanate was added to this dispersion, and a photosensitive layer-formed product was prepared by further dispersing in a ball mill for 10 minutes, and a dry adhesion amount of the conductive-treated paper was 21 g /
An electrophotographic light-sensitive material was prepared by applying a coating with a wire bar so as to give m ² and drying at 10 ° C. for 1 minute, and then leaving it in the dark at 20 ° C. and 65% RH for 24 hours.

In the above Production Example, three kinds of comparative photosensitive materials A, B and C were prepared by replacing the photosensitive layer forming material with the following copolymers.

Comparative photosensitive material A; 60 g of butyl methacrylate, 13 g of 2-hydroxyethyl methacrylate, 40 g of the compound of the above-mentioned compound example (A) and 200 g of toluene were heated to 70 ° C. under a nitrogen stream, and then 2,2 1.5 g of'-azobisisobutyronitrile was added and the reaction was carried out for 8 hours. The weight average molecular weight of the obtained copolymer [2] was 45,000.

Then, 30 g of this copolymer [A] as the solid content
And [ethyl methacrylate / acrylic acid (98.5 / 1.5)
Weight ratio] A mixture of 10 g of a copolymer (weight average molecular weight of 45,000), 200 g of zinc oxide, 0.05 g of rose bengal, 0.01 g of phthalic anhydride and 300 g of toluene was dispersed in a ball mill for 2 hours to prepare a photosensitive layer forming material. , Apply it to a conductive treated paper with a wire bar so that the dry adhesion amount will be 25 g / m ² ,
An electrophotographic light-sensitive material was prepared by drying at 110 ° C. for 1 minute and then leaving it in the dark at 20 ° C. and 65% RH for 24 hours.

Comparative photosensitive material B: a mixed solution of 87 g of butyl methacrylate, 13 g of 2-hydroxyethyl methacrylate and 200 g of toluene, and the reaction was performed under the same conditions as in the synthesis method of Example 1 except that the weight average molecular weight was changed.
46,000 copolymer [3] was obtained.

Subsequently, an electrophotographic photosensitive material was produced in the same manner as in Example 1 except that the above copolymer [3] was used instead of the copolymer [1] used in Example 1.

Comparative Photosensitive Material C: Same as Comparative Example A, except that 40 g of [ethyl methacrylate / acrylic acid (98.5 / 1.5) weight ratio] copolymer (weight average molecular weight 45,000) was used as the binder resin for the photoconductive layer. Then, an electrophotographic photosensitive material was produced.

The film properties (surface smoothness), electrostatic properties, desensitization property of the photoconductive layer (expressed by the contact angle of the photoconductive layer with water after desensitization treatment) and printability of these photosensitive materials are examined. Was. Printability is fully automatic plate making machine ELP404V (Fuji Photo Film Co., Ltd.)
(Manufactured) was exposed and developed with a developer ELP-T to form an image, and the desensitizing liquid ELP-E was used to perform etching with an etching processor. The printing machine used was a Hamada Star 800SX type manufactured by Hamada Star Co., Ltd.).

 Table 1 summarizes the above results.

The embodiments of the evaluation items described in Table 1 are as follows.

Note 1) Smoothness of photoconductive layer: Using the Beck smoothness tester (manufactured by Kumagai Riko Co., Ltd.), the smoothness (sec / cc) of the obtained photosensitive material was measured under the condition of an air capacity of 1 cc. It was measured.

Note 2) Electrostatic characteristics: A paper analyzer (Kawaguchi Electric Co., Ltd. paper analyzer) was applied to each photosensitive material in a dark room at a temperature of 20 ° C and 65% RH.
(SP-428 type) was used for corona discharge at −6 KV for 20 seconds and then left for 10 seconds, the surface potential V _o at this time was measured, and then the surface of the photoconductive layer was irradiated with visible light with an illuminance of 2.0 lux. , The time until the surface potential V _o decays to 1/10 is obtained, and the exposure amount E1 / 10 (lux · sec) is calculated from this.

Note 3) Water and contact angle: After each photosensitive material is passed through an etching processor once using a desensitizing solution ELP-E (manufactured by Fuji Photo Film Co., Ltd.) to desensitize the photoconductive layer surface. Then, a water drop of 2 μl of distilled water is placed on this, and the contact angle with the formed water is measured with a goniometer.

Note 4) Image quality of copied image: Each photosensitive material and fully automatic plate-making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.) are left at room temperature and humidity (20 ° C, 65%) for one day, and then plate-made to make a copied image. And an image (fog, image quality) of the obtained copy original plate is visually observed (this is referred to as I). The image quality II of the copied image is tested by the same method as the above I except that the plate making is performed at high temperature and high humidity (30 ° C., 80%).

Note 5) Background stain of printed matter: Each photosensitive material is made into a toner image by making a plate with a fully automatic plate making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.), and desensitized under the same conditions as above Note 3). Then, this is applied as an offset master to an offset printing machine (Hamaduster 800SX type manufactured by Hamada Star Co., Ltd.) to print 500 sheets on high-quality paper,
The background stain of all prints is visually determined. This is referred to as background smear I of the printed matter.

For the background stain II of the printed matter, the desensitizing solution was diluted 5 times, and the immersion water during printing was diluted 2 times. Further, the printing pressure of the printing press was set to be relatively high. Others are tested by the same method as that of the above-mentioned background soil I.

The case of II corresponds to printing under significantly more severe conditions than I.

Although the copied images obtained using the light-sensitive materials of the present invention and Comparative Examples A to C were all clear images, Comparative Example C
As for, the thin lines such as halftone dots and scattering were observed in the part. Further, in each of Comparative Examples B and C in which each light-sensitive material was plate-formed in an environment of (30 ° C., 80%), the copied image was remarkably deteriorated (ground fog was generated and the image density was 0.6 or less). became).

Further, the contact angles with water of the respective photosensitive materials desensitized with the desensitizing solution were as small as 15 ° C. or less for the materials of the present invention and Comparative Example A, showing that they were sufficiently hydrophilized. .

Further, when these were printed as a master plate for offset printing, only the plates of the present invention and Comparative Example A were good, with no background stain on the non-image portion. Further, when both plates were printed up to 10,000 sheets under the condition of high printing pressure, the plate of the present invention had good image quality on the 10,000th sheet and did not cause scumming. However, Comparative Example A
About 7,000 sheets and about 3,000 sheets of Comparative Example B, remarkable background stain was generated. In the plate of Comparative Example C, the occurrence of background stain was remarkable after printing.

From the above facts, only the light-sensitive material of the present invention can produce 10,000 or more printed materials which always form a clear copy image and are free from background stain even when the plate is made under changing environmental conditions.

Examples 2 to 17 In Example 1, instead of the resin [1] of the present invention,
Each electrophotographic photosensitive material was produced in the same manner as in Example 1 except that the copolymers shown in Table 2 were used.

When this was subjected to plate making with the fully automatic plate making machine ELP404V in the same manner as in Example 1, the density of the obtained master plate for offset printing was 1.2 or more and the image quality was clear. Furthermore, when etching was performed and printing was performed with a printing machine, the printed matter after printing 10,000 sheets had no fog in the non-image area and the image was clear.

Further, this light-sensitive material was left under the condition of (45 ° C., 75% RH) and then subjected to the same processing as above, but there was no change from that before the passage of time.

Example 18 Copolymer of the present invention represented by the following chemical structure [20] (weight average molecular weight 42,000) Example 30 was used except that 30 g was used instead of the copolymer [1] of Example 1 and 4 g of hexamethylene diisocyanate was used.
An electrophotographic light-sensitive material having the same composition as in Example 1 was obtained in the same manner as in Example 1.

When this was subjected to plate making using the same apparatus as in Example 1, the density of the obtained offset printing master plate was 1.0 or more, and the image quality was clear. Further, after etching and printing with a printing machine, the printed matter after printing 10,000 sheets had clear image quality without fog.

Further, this light-sensitive material was left under the condition of (45 ° C., 75% RH) and then processed in exactly the same manner as above, but there was no change from that before aging.

Examples 19 to 23 Photosensitive materials were prepared in the same manner as in Example 1 except that the compounds shown in Table 3 below were used instead of the hexamethylene diisocyanate used in Example 1.

This was subjected to plate making with the same device as in Example 1, then etching treatment and printing with a printing machine. The density of the master plate for offset printing obtained after plate making was 1.0 or more, and the image quality was clear. The image quality of the printed matter after printing 10,000 sheets was a clear image without background fog.

(Effects of the Invention) According to the present invention, an original plate for electrophotographic lithographic printing having excellent background stain and printing durability can be obtained.

Claims (1)

[Claims] 1. A copolymerization component containing, on a conductive support, at least photoconductive zinc oxide and at least one functional group capable of generating at least one carboxyl group by decomposition represented by the following general formula (VI). And a resin (A) each containing a copolymerization component containing at least one functional group capable of undergoing a curing reaction with heat and / or light, and a function of causing a curing reaction with heat and / or light in the resin (A). An electrophotographic lithographic printing plate precursor comprising a photoconductive layer obtained by coating a liquid containing toluene and a crosslinking agent capable of chemically reacting with a group. General formula (VI) X ': -O-, -CO-, -COO-, -OCO-, -CON
(D ₁ )-, an aromatic group or a heterocyclic group (provided that d ₁ is a hydrogen atom, a hydrocarbon group or-(Y'-W) in formula (VI))
Y ': a carbon-carbon bond which connects the linking group X'and the linking group W and which may pass through a hetero atom (provided that the hetero atom is an oxygen atom, a sulfur atom or a nitrogen atom), W: a functional group that decomposes to generate a carboxyl group, a ₁ , a ₂ : may be the same or different, and is a hydrogen atom, a halogen atom, a cyano group or an optionally substituted carbon atom 1 to
7, a hydrocarbon group.