JPS6365201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polymer sensitizer that provides a photoinsoluble resin composition having excellent photosensitivity and a method for producing the same. More specifically, the present invention relates to a visible light-sensitizing polymer having a rhodanine residue conjugated with a dialkylaminophenyl group in its side chain as a photosensitizing residue, and a method for producing the same. Many studies have been conducted to increase the photosensitivity of photoinsoluble resins based on the principle of photopolymerization, but most of them involve photopolymerization sensitizers (initiators) that are active in ultraviolet light.
It is related to. On the other hand, photosensitive resins are attracting attention as photoresist materials, inks, paints, varnishes, printing plate materials, etc., and as image forming materials that use laser light and photosensitive materials that replace silver salts. The photosensitivity of conventional materials is extremely inadequate. Therefore,
It is necessary to expand the photosensitive wavelength range and dramatically increase the photosensitive speed. In this case, it goes without saying that the photosensitive resin must have both high resolution, which is an excellent characteristic, and various physical properties suitable for the purpose. Several proposals have been made for photopolymerizable resins that are sensitive to visible light. In JP-A-48-36281, S having at least one trihalomethyl group conjugated to a triazine ring due to ethylenically unsaturated and at least one chromophore moiety
- A method using triazine as a polymerization initiator has been proposed, and in JP-A-54-155292, p
A composition using an unsaturated ketone conjugated with -dialkylaminoallylidene as a photopolymerization initiator has been proposed. Moreover, in JP-A-52-134692, a composition using a polycyclic quinone and a tertiary amine as a photopolymerization initiation system is proposed. All of these can provide materials that are sensitive to longer wavelength light than conventional photopolymerizable resins, but they require even higher sensitivity in order to be used as photosensitive materials for lasers or silver salt substitute materials. is necessary. The photosensitivity of a photoinsolubilized resin depends on the molecular weight of the polymer to be insolubilized, the efficiency of the crosslinking reaction necessary for photoinsolubilization,
and the absorbance of the photosensitive group. The polymer composition that is sensitive to visible light is characterized by containing a low-molecular-weight photopolymerization initiator that absorbs visible light, so it is highly sensitive by focusing on the absorbance of the photosensitive group. I can say that. As a result of careful consideration of the above points, the inventors of the present invention have found that by polymerizing the photopolymerization initiator that absorbs visible light, it is possible to achieve even higher sensitivity. The present invention was developed based on the idea that improved resolution could also be expected. That is, the present invention provides the general formula () [In the formula, R is a simple bond or -OCO (-CH ₂
)-m- (where m is an integer from 1 to 3)
, R ₁ represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, and R ₂ represents a methyl group or an ethyl group] A photosensitizing structural unit consisting of rhodanine conjugated with a dialkylaminophenyl group ( A) and
General formula () (In the formula, R ₃ represents at least one residue selected from an alkyl group, a phenyl group, a vinyl group, an isopropenyl group, and a 2-alkylvinyl group.) (In the formula, R ₄ represents a hydrogen atom or a methyl group,
R ₅ represents at least one residue selected from phenyl group, alkoxycarbonyl group, carbamoyl group, 2-ketopyrrolidyl group, and cyano group) (meth)acrylic vinyl structural unit (C)
Each constituent unit (A), (B), (C)
The present invention provides a photosensitized polymer having a molecular weight in the range of 1,000 to 1,000,000 and a molecular weight of 1 to 30, 0 to 70, and 99 to 0 mol%, respectively, and a method for producing the same. The present inventors have discovered that the residue having a rhodanine derivative represented by the general formula () used in the present invention becomes an efficient photopolymerization initiator for visible light. That is, by combining this rhodanine derivative with an auxiliary substance having electron-accepting ability, polymerization is initiated by visible light absorbed by this rhodanine derivative. According to the present invention, by bonding a photosensitive compound having the ability to initiate photopolymerization to a polymer, this initiation site itself directly participates in the insolubilization of the polymer by radical polymerization, resulting in even higher sensitivity. is achieved. In order to produce the polymer sensitizer of the present invention having these features, it is necessary to efficiently polymerize this relatively large molecular weight residue. The present invention also provides such a method. Below, a method for producing a photosensitizing polymer having a photosensitizing structural unit represented by the general formula () will be explained. In order to obtain the photosensitized polymer of the present invention, a polymer of chloromethylstyrene or a copolymer thereof,
General formula () (In the formula, R, R ₁ and R ₂ have the same meanings as above,
A rhodanine derivative conjugated with a dialkylaminophenyl group represented by (M represents an alkali metal ion or a tetraalkylammominium ion) may be reacted. Furthermore, if desired, a carboxylic acid salt represented by the general formula () MOCOR ₃ (wherein M and R ₃ have the same meanings as above) may be reacted.
In particular, by reacting the carboxylate represented by the general formula (), the physical properties of the resulting photosensitized polymer can be adjusted, and the storage stability of the polymer can be improved by consuming active chloromethyl groups. can be significantly increased. Alternatively, if an unsaturated carboxylic acid salt is used, since it will itself participate in photopolymerization, a highly sensitive photo-insoluble resin composition can be provided. Examples of rhodanine derivatives represented by the general formula () used here include alkali metal salts such as lithium, sodium, and potassium of the following compounds, and ammonium ions such as tetramethylammonium, tetraethylammonium, and triethylbenzylammonium. be able to. In addition, carboxylic acid salts represented by the general formula () include acetic acid, propionic acid, butyric acid, valeric acid,
Alkyl carboxylic acids such as hexanoic acid, 2-ethylhexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, and decanoic acid; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, α-methylcrotonic acid, and 2-hexenoic acid. Preferred are acid or alkali metal salts such as lithium, sodium, and potassium such as benzoic acid, and ammonium salts such as tetramethylammonium, tetraethylammonium, and triethylbenzylammonium. As the vinyl polymeric polymer containing at least 1 mol % of chloromethylstyrene used in the method for producing a photosensitized polymer in the present invention, a polymer of chloromethylstyrene or a copolymer thereof is preferable. The comonomer in the copolymer is
Acrylonitrile, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate,
Ethyl methacrylate, butyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, N,N-dimethylacrylamide, N,N
-dimethylmethacrylamide, N-vinylpyrrolidone, styrene, etc. It goes without saying that these monomers can be used alone or in combination. In order to react the rhodanine derivative represented by the general formula () and the carboxylic acid salt represented by the general formula () with a chloromethylstyrene polymer or copolymer, the reaction is preferably carried out in a polar solvent. Preferred polar solvents include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and dichlorobenzene. The reaction temperature is preferably between room temperature and 120°C. If it is less than this, the reaction time will increase significantly, and if it is more than this, gelation may occur during the reaction. The reaction time is about 1 hour to 20 hours, depending on the reaction temperature and the reactivity of the halogen-containing polymer. Furthermore, in this method, an alkali salt of the compound represented by the general formula () may be reacted with a halogen-containing polymer compound in an organic solvent using a crown ether, or an organic ammonium salt, a phosphonium salt, etc. The reaction may be carried out in a two-phase system with an organic solvent using a phase transfer catalyst. Since the compound represented by the general formula () has an amino group, there is a possibility that quaternization may occur due to the active chlorine group, but in reality, this amino group has a reduced reactivity due to the conjugated ketone via the benzene ring. Therefore, quaternization is unlikely to occur. In order to reliably prevent the product from gelling due to quaternization, the sum of the compounds represented by the general formula () and the general formula () should be equal to or 5 times the molar amount relative to the chloromethyl group. Just prepare it so that it will work. The polymer having a photosensitizing residue in its side chain obtained by the present invention cannot be made insolubilized by light irradiation alone, but it can be coexisted with a compound that transfers one electron and generates a radical species by light irradiation. This results in a highly efficient photopolymerization initiation system. The electron-reduced compounds used for this purpose are electron-accepting, examples being ketones or quinones such as benzophenone, benzoquinone, naphthoquinone, anthraquinone, benzanthrone, fluorenone, diphenyliodonium salts, ditolyl. Iodonium salts such as iodonium salts and di(m-nitrophenyl)iodonium salts,
2,4,6-tris(trichloromethyl)-S-
Triazine, 2-methyl-4,6-bis(trichloromethyl)-S-triazine, 2-phenyl-
S-triazine derivatives such as 4,6-bis(trichloromethyl)-S-triazine, P-nitro-
α,α,α-tribromoacetophenone, 0-nitro-α,α,α-tribromoacetophenone,
Trihaloacetylated benzene derivatives such as α,α,α-tribromoacetophenone, benzene derivatives with trihalomethanesulfonyl groups such as tribromomethanesulfonylbenzene, 1-tribromomethanesulfonyl-3-nitrobenzene, triphenylbisimidazolyl, etc. Among these, iodonium salts and triazine derivatives are particularly effective. These electron-accepting compounds are used in an amount of 0.5 to 10 molar equivalents to the photosensitive residue represented by the general formula (),
More preferably, by mixing 1 to 5 molar equivalents, a highly efficient photopolymerization initiation system can be obtained. The compound having at least one ethylenically unsaturated bond having polymerizability as the third component constituting the photoinsoluble resin composition containing the polymer sensitizer of the present invention is a vinyl-based It may contain oligomers in addition to monomers, and may also be high molecular weight compounds. Specifically, there are high boiling point monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, acrylamide, methacrylamide, diacetone acrylamide, and N-vinylcarbazole, as well as ethylene glycol, diethylene glycol, and triethylene. Glycol, tetraethylene glycol, 1,3
-propanediol, 1,4-butanediol,
Di- or polyacrylic esters such as 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, trimethylolethane, pentaerythritol, sorbitol, mannitol, di- or polymethacrylic esters, and even di- or polymethacrylic esters. Examples include acrylated or methacrylated epoxy resins, polyester acrylate oligomers, acrylated or methacrylated urethane oligomers, and acroleinated polyvinyl alcohol. The amount of these polymerizable compounds is preferably 0.1 to 5 parts per 1 part of the polymer sensitizer of the present invention. It goes without saying that these polymerizable compounds need not be used alone, but may be a mixture of two or more. The photoinsoluble resin composition comprising the polymer sensitizer of the present invention becomes insolubilized at a very high rate against light of a wavelength that is absorbed by the photosensitive group represented by the general formula (). This is because this photosensitive group absorbs light energy and transfers electrons to the electron-accepting compound, resulting in a cation radical represented by the following partial structural formula. This is thought to be because protons are detached from the alkyl group (R ₃ ), thereby starting radical polymerization and causing graft polymerization. Furthermore, the fact that the electron-accepting compound itself generates a radical after transferring one electron and becomes an initiator is considered to be one reason why the resin composition comprising the polymer sensitizer of the present invention exhibits high sensitivity. Light sources suitable for the polymer sensitizer of the present invention include:
In addition to high-pressure mercury lamps, ultra-high-pressure mercury lamps, high-pressure xenon lamps, halogen lamps, and fluorescent lamps, He-Cd lasers and
Ar laser can be used. Since the photoinsoluble resin composition comprising the polymer sensitizer of the present invention has superior characteristics in sensitivity and resolution than conventional photopolymerizable compositions, it can It can be applied to a wide range of fields such as creating non-silver halide images and making printed wiring boards, and is also effective for negativeless plate making because it is sensitive to laser light. Furthermore,
It can also be used as an element material for photoelectric conversion. Below, the present invention will be explained in more detail with reference to Examples. Examples 1 and 2 To a solution of 1.13 g of potassium hydroxide dissolved in 1 g of water and further diluted with 150 g of ethanol, 5 g of 4-oxo-5-(p-diethylaminobenzylidene)thiazolidine-2-thione was added and gradually heated. The mixture was stirred at the same time until the crystals were dissolved. Then,
The solvent was distilled off from this solution under reduced pressure, and the precipitated crystals were recrystallized from ethanol to obtain a potassium salt. Copolymer consisting of 53.8 g of methyl methacrylate and 6.2 g of chloromethylstyrene (mixture of meta and para isomers) (Mw=6.15×10 ⁵ , Mn=1.82×
10 ⁵ ) Dissolve 1.63g in 25g of dimethylformamide and add the above potassium salt while stirring at 75℃.
0.38g was added and reacted for 2 hours. The reaction solution was poured into 200 ml of a methanol-water (3:2) mixture to obtain a reddish-orange polymer into which a sensitizing group had been introduced. This polymer was dissolved in tetrahydrofuran, and the introduction rate of rhodanine residue was 6.5 from the absorbance in the solution.
It was calculated as mol%. When this solution was spin-coated onto a slide glass plate and its absorption spectrum was measured, it showed an absorption maximum at 481 nm. In the above reaction, a polymer into which a sensitizing group was introduced was obtained in exactly the same manner by using a p-dimethylaminobenzylidene derivative instead of a p-diethylaminobenzylidene derivative. A photosensitive solution consisting of 2 g of a 10% by weight solution of these polymers in tetrahydrofuran, 0.15 g of pentaerythritol triacrylate, 36 mg of diphenyliodonium hexafluorophosphate, and 0.5 g of chloroform was applied to an anodized aluminum plate, and Kodak Step Tablet No. When masked with 1 and exposed to a xenon lamp, up to 5 stages were insolubilized in 20 seconds each. This corresponded to approximately 10 times the sensitivity of the sensitized polyvinyl cinnamate-based photosensitive material. Example 3 3-(carboxymethyl)-4-oxo-5-
26.5 g of (p-dimethylaminobenzylidene) thiazolidine-2-thione was dissolved in 200 g of ethanol, 100 ml of an ethanol solution containing 5.0 g of potassium hydroxide (85%) was added thereto, and the precipitate was filtered and dried. Potassium salt was obtained. 1.63 g of the methyl methacrylate-chloromethylstyrene copolymer used in Example 1 was dissolved in 25 g of dimethylformamide, and 0.43 g of the above potassium salt was added while stirring at a liquid temperature of 75° C., followed by reaction for 3 hours. The reaction solution was poured into a methanol-water (3:2) mixture to isolate the polymer. This polymer was dissolved in tetrahydrofuran, and the introduction rate of rhodanine residues was determined to be 6.3 mol% from the absorbance of the solution. Since the beil-shiutaine reaction is negative, the remaining 93.7 mol% will be methyl methacrylate units. A film obtained by spin coating this solution showed an absorption maximum at 481 nm. As a result of measuring the sensitivity in the same manner as in Examples 1 and 2, it was found that this polymer was about 10
It showed twice the sensitivity. Examples 4 to 10 1.26 g of a 1:1 copolymer of chloromethylstyrene and methyl methacrylate (Mw: 200,000) was dissolved in 20 g of dimethylformamide, and 0.53 g of potassium methacrylate was added while stirring at 75°C. Allowed time to react. Next, 0.34 g of the potassium salt used in Examples 1 and 2 was added and reacted at the same temperature for 2 hours. The reaction solution was spun down using a centrifuge, and the supernatant solution was separated by decantation, which was poured into a methanol-water mixed solvent to separate the polymer. This polymer was dissolved in tetrahydrofuran, and the absorbance of this solution showed that the rhodanine residue was 6.8 mol%.
The Weilstein reaction was negative. Therefore, the content of methyl methacrylate units is determined to be 50%, and the content of acetoxymethylstyrene units is determined to be 43.2 mol%. Diphenyliodonium hexafluorophosphate was added to this solution in an amount of 10% by weight based on the polymer, and the solution was spin coated on an anodized aluminum plate to measure sensitivity. Polyvinyl cinnamate photosensitive material (Tokyo Ohka Kogyo: TPR) using a xenon lamp as the light source
The relative value for . Polymers were also synthesized in exactly the same manner using various unsaturated carboxylic acids instead of potassium methacrylate. The introduction rate of rhodanine residues was comparable to that above. The results of measuring their sensitivities are also shown in Table 1. Light irradiation was performed not only in air but also under partial vacuum degassing. 【table】

Claims (1)

[Claims] 1. General formula (In the formula, R is a simple bond or -O-CO(-
CH ₂ )-m- (in the formula, m is an integer from 1 to 3), R ₁ is a hydrogen atom, a lower alkyl group,
A photosensitizing structural unit (A) consisting of rhodanine conjugated with a dialkylaminophenyl group represented by (a lower alkoxyl group, R ₂ represents a methyl group or an ethyl group); (In the formula, R ₃ represents at least one residue selected from an alkyl group, a phenyl group, a vinyl group, an isopropenyl group, and a 2-alkylvinyl group.) formula (In the formula, R ₄ represents a hydrogen atom or a methyl group,
R ₅ is an alkoxycarbonyl group, a carbamoyl group,
A (meth)acrylic vinyl structural unit (C) represented by (representing at least one residue selected from a 2-ketopyrrolidyl group and a cyano group)
Each constituent unit (A), (B), (C)
A photosensitized polymer having a molecular weight in the range of 1,000 to 1,000,000, each of which is 1 to 30, 0 to 70, and 99 to 0 mol%. 2 General formula A structural unit consisting of 1 to 100 mol% chloromethylstyrene represented by the general formula (In the formula, R ₄ represents a hydrogen atom or a methyl group,
R ₅ is an alkoxycarbonyl group, a carbamoyl group,
(representing at least one kind of residue selected from 2-ketopyrrolidyl group, cyano group) (In the formula, R is a simple bond or -O-CO(-
CH ₂ )-m- (in the formula, m is an integer from 1 to 3), R ₁ represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, and R ₂ represents a methyl group or an ethyl group. , M represents an alkali metal ion or a tetraalkylammonium ion) A rhodanine derivative conjugated with a dialkylaminophenyl group represented by the general formula R ₃ COOM (wherein R ₃ and M have the same meanings as above) ), a general formula characterized by reacting with (In the formula, R, R ₁ and R ₂ have the same meanings as above) A photosensitizing structural unit (A) consisting of rhodanine conjugated with a dialkylaminophenyl group represented by (In the formula, R ₃ has the same meaning as above) and the structural unit (B) represented by the general formula (In the formula, R ₄ and R ₅ have the same meanings as above.) (Meth)acrylic vinyl structural unit (C)
Each constituent unit (A), (B), (C)
A method for producing a photosensitized polymer having a molecular weight in the range of 1,000 to 1,000,000, each of which is 1 to 30, 0 to 70, and 99 to 0 mol%.