JP4522751B2 - Photosensitive film, screen printing plate and etching photosensitive film - Google Patents

Description

  The present invention relates to a photosensitive transparent film comprising polyvinyl alcohol, a photoacid generator and an epoxy compound, a screen printing plate using the photosensitive transparent film, and an etching resist film.

The resin film sensitive to active energy rays forms a pattern by its chemical structural change caused by the action of active rays. Active rays include light, infrared rays, far infrared rays, electron beams, X-rays, and the like. Among active rays, those widely used are light.
A photosensitive film having a thickness of several μm to several tens of μm is widely used as a wet or dry etching material. In order to perform wet or dry etching using this film, the film is attached to the surface of the etching substrate, exposed to this, developed with a solvent to form a relief pattern, and then wet or dry etching is performed. . In this case, the film is called a dry film resist in wet etching and a sandblast resist film in dry etching. On the other hand, dry films used for circuit insulation protection are covered with coverlay films. It is also used to obtain a stencil for screen printing by applying a photosensitive film to a screen mesh to form a screen printing plate, exposing the film to water and developing it, and this is called a direct film.

  A thick photosensitive film suitable for these purposes must satisfy the following basic characteristics. Properties required for the film before exposure include long-term storage stability, adhesion to a substrate, surface smoothness, transparency, and the like. The characteristics required at the time of exposure and development include appropriate exposure sensitivity, photomask reproducibility in the exposed area, developability with an aqueous developer in the unexposed area, and the like. Properties required for the relief pattern after development include high resolution, chemical resistance, mechanical strength, and the like. Among these, development with an aqueous solvent is indispensable. However, as the pattern line width is increased, further improvement in high resolution and photomask shape reproducibility is required. For this purpose, a photosensitive film excellent in transparency without light scattering is required.

  A dry film resist for etching is most widely used as a thick photosensitive film. The main components of this type of photosensitive film are a binder polymer composed of a (meth) acrylic acid copolymer, a photoradical polymerizable monomer such as a polyfunctional (meth) acrylate and styrene, and a photoradical polymerization initiator ( Edited by Radtech Research Group, “Current Status and Prospects of UV / EB Curing Technology”, CMC Publishing, 2002, p. 219). These are dissolved in an organic solvent and applied onto a transparent resin film to remove the solvent, and then a cover film is provided to produce a photosensitive film having a three-layer structure. The cover film is an indispensable member because it not only protects the flexible unpolymerized layer but also serves as an oxygen barrier layer that prevents the effect of inhibiting photoradical polymerization by oxygen in the air. When the photosensitive layer is attached to the substrate surface by thermocompression bonding, etc., the cover film is peeled off, the exposure is performed through the substrate film, and then the unexposed areas are generally dissolved with alkaline water. Removal and development to obtain a relief pattern.

This type of dry film resist has good sensitivity because it uses a radical polymerization reaction, and has the advantage that the physical properties can be adjusted according to the purpose by appropriate selection of monomers, while volume shrinkage associated with the vinyl polymerization reaction. This is a problem in ensuring reproducibility of a more precise line width. In addition, since the exposure is performed through the substrate film, a highly transparent substrate film is required to obtain a more precise line width. In addition, since the photosensitive composition contains an organic solvent, there is a problem that the organic solvent must be removed in the step of forming a photosensitive film, and alkaline water is used from the viewpoint of work safety and waste liquid treatment. However, it is obvious that a photosensitive film that can be developed with neutral water is more preferable. Furthermore, when the etching substrate does not have resistance to alkaline water, alkali development cannot be performed, and development with neutral water is required.

  As described above, a photosensitive film which can be formed into a film without scattering an organic solvent, has a basic characteristic as described above, and gives a relief pattern by development with neutral water. However, a photosensitive film that can be formed into a film without using an organic solvent and that can be developed with neutral water is limited. Examples of the aqueous photosensitive resin necessary for this purpose are as follows. A material in which dichromate is added to a water-soluble polymer such as gelatin, casein or polyvinyl alcohol has long been put to practical use. However, it contains heavy metal ions and has a significantly poor storage stability. Use as is excluded. An aqueous photosensitive resin composition using a water-soluble diazo resin as a photocrosslinking agent has a lower photosensitivity than a dichromate-based photosensitive resin, and light transmission is limited as the exposed portion is colored. Therefore, there are problems such as being unsuitable for a thick photosensitive film and being inferior in storage stability over a long period of time, and its range of use is limited. A composition in which an ethylenically unsaturated compound and a photopolymerization initiator are emulsified in polyvinyl alcohol and a photocrosslinking agent is blended therein [JP 49-121852 (Patent Document 1), JP 50-108003]. [Patent Document 2], Japanese Patent Application Laid-Open No. 59-107343 (Patent Document 3), etc.] have been proposed, but since the crosslinked structure is not formed in the polyvinyl alcohol itself, the water resistance of the relief image is insufficient. is there.

  A water-developable photosensitive polymer in which a hydrophilic photosensitive residue typified by styrylpyridinium is bonded to polyvinyl alcohol is also known [JP 55-23163 (Patent Document 4), JP 55- 62905 gazette (patent document 5), Unexamined-Japanese-Patent No. 58-25303 (patent document 6), etc.]. Taking advantage of features such as higher sensitivity than other water-developable photosensitive resins and excellent long-term storage stability, they are used in pattern forming materials represented by screen platemaking materials. However, insolubilization of the film obtained from the photosensitive polymer in water is achieved by a crosslinking reaction based only on the photodimerization reaction, so that the water resistance is poor. For this reason, improvement in physical properties by using various additives has been devised. For example, JP-A-55-62446 (Patent Document 7), JP-A-60-10245 (Patent Document 8), JP-A-61-17141 (Patent Document 9), JP-A-56-122784. No. (Patent Document 10), Japanese Patent Application Laid-Open No. 60-10245 (Patent Document 11), and the like have been proposed. However, the photosensitive films obtained from these compositions still have problems in various physical properties such as water resistance, chemical resistance and mechanical strength.

  JP-A-9-31980 (Patent Document 12) proposes a water-developable photosensitive composition obtained by adding a water-soluble photoacid generator to polyvinyl alcohol and an acid-reactive crosslinking agent. However, the types of water-soluble photoacid generators are limited, and there remains a problem that the acid generated here is low in acid strength due to the carboxylic acid. In addition, this type of photosensitive film containing a diazoketone photoacid generator has difficulty in long-term storage stability due to its thermal decomposability.

JP-A-59-184220 (Patent Document 13) proposes a photosensitive aqueous dispersion composition containing an epoxy compound compound dispersed in water and an onium salt as a photocationic polymerization initiator. Furthermore, a screen for screen printing by directly applying and drying the composition, and a stencil obtained by exposing and developing the screen are also proposed. In general, epoxy compounds are stable in the absence of water, but it is known that a reaction with water can occur. For example, epoxy compounds having tertiary carbon and cyclic epoxy compounds such as cyclopentene oxide react with water in the absence of an acid catalyst to give a diol (Houben-Weyl; Methoden der Organischen Chemie, Sauerstoff-Verbindungen, Teil). 3, Georg Thieme Verlag, Stuttgart, p. 454 (1965) (Non-patent Document 3)). Therefore, the water-dispersible photosensitive resin composition containing an epoxy compound having at least tertiary carbon has a difficulty in long-term storage stability.
Japanese Patent Application Laid-Open No. 10-62990 (Patent Document 14) proposes an aqueous photosensitive composition for screen printing comprising polyvinyl alcohol, an epoxy compound and a photocationic polymerization initiator. Actually, as a fourth component, diazo resin, dichromate, or polyvinyl alcohol having a photocrosslinkable stilbazolium group introduced is added to the composition as a fourth component. This is presumed to be because the epoxy compound causes an addition reaction with water remaining in the coating film due to the acid catalysis of the photocationic polymerization initiator, thereby suppressing the polymerization reaction.

By the way, it is widely known that a cationic photopolymerization resin made of an epoxy compound has a feature that it is not inhibited by oxygen compared to a radical photopolymerization resin, but is susceptible to curing inhibition by moisture or an alkali component. [Ichimura, supervised by Tsunooka, “Practical guide to photocuring technology”, Technonet (2002), pages 71 to 75 (non-patent document 4)]. Polyvinyl alcohol is a highly hydrophilic polymer, which makes it difficult to completely remove moisture from the coating film obtained from the composition, and the cationic polymerization reaction of the epoxy compound competes with the addition reaction of water. It is inferred that it will decrease.
Therefore, it can be manufactured and developed with neutral water by utilizing the characteristics of the epoxy-based cationic polymerization composition that is not affected by oxygen inhibition, has a small polymerization volume shrinkage, and has excellent adhesion to a substrate. In order to achieve high resolution, a highly transparent photosensitive film has been desired.

Japanese Patent Laid-Open No. 49-121852 JP 50-108003 A JP 59-107343 A JP-A-55-23163 JP-A-55-62905 JP 58-25303 A JP 55-62446 A Japanese Patent Application Laid-Open No. 60-10245 JP-A 61-17141 JP 56-122784 A JP 59-184220 A Japanese Patent Application Laid-Open No. 60-10245 Japanese Patent Laid-Open No. 9-319080 JP-A-10-62990 Japanese Patent Laid-Open No. 5-140143 JP-A-9-118663 Japanese Patent Laid-Open No. 5-140209 JP-A-54-151024 JP 58-40302 A JP 60-76740 A JP 60-78443 A JP-A-60-88005 JP 60-11802 A JP-A-61-97650 JP-A-61-180359 Japanese Patent Laid-Open No. 62-161820 JP 63-243102 A Akio Yamaoka, Mototaro Matsunaga, “Photopolymer Technology”, Nikkan Kogyo Shimbun (1988) C. P. Ed. Wong, Polymers for Electronic and Photonic Applications, Academic Press, p. 67 (1993) Houben-Weyl; Methoden der Organischen Chemie, Sauerstoff-Verbindungen, Tail 3, Georg Thieme Verlag, Stuttgart, p. 454 (1965) Ichimura, supervised by Kakuoka, “Practical guide for photocuring technology”, Technonet (2002), pages 71-75 Organic Materials for Imaging ", Bunshin Publishing (1993), 187-192 pages Taiga, Hirashima, Matsuoka, Kitao, "Dye Handbook" (Kodansha) Edited by the Color Materials Association, “Color Material Engineering Handbook”, Asakura Shoten (issued in 1989) Hayashibara Biochemical Research Laboratories Photosensitizing dye research institute "Dye Catalog"

  The present invention provides a photosensitive transparent film, a screen printing plate, a stencil for screen printing, and a dry film resist that can be formed into a film without using an organic solvent and can be developed with neutral water after light irradiation. Is the subject.

As a result of intensive studies to solve the problems in the previous term, the present inventors have completed the present invention.
That is, according to the present invention, the following photosensitive transparent film, screen printing plate, stencil for screen printing, and dry film resist that can be developed with neutral water are provided.

(1) An aqueous solution of 100 parts by weight of polyvinyl alcohol having a saponification rate of 60% or more has 12 to 200 parts by weight of a photoacid generator that generates Bronsted acid or Lewis acid by the action of active energy rays, and at least one epoxy group. A photosensitive transparent film obtained by laminating a photosensitive resin composition in which 10 to 2000 parts by weight of an epoxy compound is dissolved or dispersed on a support film.
(2) The photosensitive transparent film as described in (1) above, wherein the photosensitive resin composition contains a cationically polymerizable oxetane compound.
(3) The said photosensitive resin composition contains the nitrogen-containing compound, hydroxymethylated phenol derivative, or resole resin by which N-methylolation or N-alkoxymethylation was carried out, (1) or (2) The photosensitive transparent film of description.
(4) A screen printing plate comprising the photosensitive film according to any one of (1) to (3) wetted with an aqueous medium and attached to a screen mesh.
(5) A stencil for screen printing, wherein the screen printing plate according to (4) is irradiated with light and subjected to heat treatment as necessary, and then developed with water.
(6) The photosensitive transparent film for etching, wherein the transparent film of any one of (1) to (3) is wetted with an aqueous medium and attached to a substrate.

The photosensitive transparent film according to the present invention has a great feature that it is excellent in long-term storage and high transparency. In the case of this photosensitive film, the solvent used for coating and development is mainly neutral water, and thus has environmentally friendly characteristics, and has the following effects.
(1) Since only water is used as a solvent in the production and development of the photosensitive film, it is suitable for safety in the work environment, fire prevention, pollution prevention, and the like.
(2) Since various sensitizers can be used in combination, the resin film is sensitive to a wide wavelength range from the far ultraviolet to the near infrared region.
(3) A screen printing plate and a stencil for screen printing can be obtained by applying the film to a screen base material to form a photosensitive resin film and exposing the film.
(4) By wet laminating the film on an etching substrate, a dry film resist that is not subject to oxygen inhibition can be obtained.

  The polyvinyl alcohol used in the present invention may have any degree of saponification of 60% or more, preferably 80% or more and a polymerization degree of 300 to 4500. Further, water-soluble polyvinyl alcohol acetalized with butyraldehyde or acrolein, or polyvinyl alcohol modified by copolymerization of a monomer having a cationic group can be used. In the modified polyvinyl alcohol in this case, the proportion of the unmodified vinyl alcohol component contained in the main chain is at least 60 mol%, preferably 70 mol% or more.

  The photoacid generator that generates Bronsted acid or Lewis acid by the action of light in the present invention is a conventionally known compound having cationic polymerization initiating ability, and is a compound used in a chemically amplified photoresist or a photocationic polymerization system. (Organic Electronics Materials Study Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), pages 187 to 192) (Non-Patent Document 5)] As the photoacid generator used in the present invention, In particular, a photocationic polymerization initiator that generates a strong acid for initiating cationic polymerization is preferred, and examples of suitable compounds are as follows. is there.

That is, as the ionic photoacid generator, Cl ⁻ , Br ⁻ , I ⁻ , ZnCl ₃ ⁻ , HSO ₃ ⁻ , BF ₄ ⁻ , PF of onium cations such as diazonium, ammonium, iodonium, sulfonium, phosphonium, ferrocenium and the like can be used. _{^{6 -, AsF 6 -, SbF}} 6 -, CH 3 SO 3 -, CF 3 SO 3 -, perfluorobutane sulfonate, perfluorooctane sulfonate, camphorsulfonate, benzenesulfonate, p- toluenesulfonate, 9,10-dimethoxy anthracene 2-sulfonate, cyclohexylamino ^{_{sulfonate, (C 6 F 5) 4}} B - can be mentioned salts such as ^{_{-, (C 4 H 9)}} 4 B.

  Specific examples of the onium cation include phenyldiazonium, p-methoxydiazonium, α-naphthyldiazonium, biphenyldiazonium, diphenylamine-4-diazonium, 3-methoxydiphenylamine-4-diazonium, 2,5-diethoxy-4-methoxy. Benzoylamidophenyldiazonium, 2,5-dipropoxy-4- (4-tolyl) thiophenyldiazonium, 4-methoxydiphenylamine-4-diazonium, condensates of 4-diazodiphenylamine and formaldehyde, 1-methoxyquinolinium, 1 -Ethoxyisoquinolinium, 1-phenacylpyridinium, 1-benzyl-4-benzoylpyridinium, 1-benzylquinolinium, N-substituted benzothiazolium [JP-A-5-140143 Distribution (Patent Document 5), and the like.

  Further, benzyltriphenylsulfonium, p-methoxyphenyldiphenylsulfonium, bis (p-methoxyphenyl) phenylsulfonium, tris (p-methoxyphenyl) sulfonium, p-phenylthiophenyldiphenylsulfonium, benzyltetramethylenesulfonium, phenacyltetramethylene Sulfonium, phenacyldimethylsulfonium, p-methoxyphenyldiethylsulfonium, naphthyldialkylsulfonium [JP-A-9-118663 (Patent Document 16), JP-A-5-140209 (Patent Document 17)], (2-naphthylcarbonyl) Methyl) tetramethylenesulfonium, (p-hydroxyphenyl) dithymesulfonium, (4-hydroxynaphthyl) -dimethylsulfonium, (4 -Dihydroxynaphthyl) -1-dimethylsulfonium, (4,8-dihydroxynaphthyl) -1-dimethylsulfonium, diphenyliodonium, phenyl (4-methoxyphenyl) iodonium, phenyl {4- (tert-butyl) phenyl} iodonium, 4-bis {4- (tert-butyl) phenyl} iodonium, bis (4-dodecylphenyl) iodonium, (4-methoxyphenyl) (4-octyloxyphenyl) iodonium, phenacyltriphenylphosphonium, cyanomethyltriphenylphosphonium Etc.

  Examples of photoacid generators that generate sulfonic acid include 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, 1- (p-toluenesulfonyloxyimino) -1-phenylethanenitrile, -(P-toluenesulfonyloxyimino) -1-phenylethanenitrile, benzoin p-toluenesulfonate, 2-p-toluenesulfonyloxy-2-benzoylpropane, p-nitrobenzyl 9,10-dimethoxyanthracene-2-sulfonate, N-trifluoromethanesulfonyloxydiphenylmaleimide, Np-toluenesulfonyloxysuccinimide, N-camphorsulfonyloxysuccinimide, N-trifluoromethanesulfonyloxysuccinimide, N-perfluoro Tansulfonyloxysuccinimide, Np-toluenesulfonyloxyphthalimide, N-camphorsulfonyloxyphthalimide, N-tolufluoromethanesulfonyloxyphthalimide, N-perfluorobutanesulfonyloxyphthalimide, Np-toluenesulfonyloxy-1, 8-naphthalenecarboximide, N-camphorsulfonyloxy-1,8-naphthalenecarboximide, N-trifluoromethanesulfonyloxy-1,8-naphthalenecarboximide, N-perfluorobutanesulfonyloxy-1,8-naphthalenecarboximide 1,2,3-tris (p-toluenesulfonyloxy) benzene, bis (phenylsulfone), bis (phenylsulfonyl) methane, and the like.

  The photoacid generators exemplified above alone generate the corresponding Bronsted acid or Lewis acid by the action of light. In the present invention, various conventionally known sensitizers can coexist. Since the photo acid generator exemplified above functions as an electron acceptor, the sensitizers used in the present invention are disclosed in JP-A-54-151024 (Patent Document 18) and JP-A-58-40302. Gazette (Patent Document 19), JP-A-60-76740 (Patent Document 20), JP-A-60-78443 (Patent Document 21), JP-A-60-88005 (Patent Document 22), Japanese Unexamined Patent Publication No. 60-112802 (Patent Document 23), Japanese Unexamined Patent Publication No. 61-97650 (Patent Document 24), Japanese Unexamined Patent Publication No. 61-180359 (Patent Document 25), Japanese Unexamined Patent Publication No. 62-161820 ( As described in JP-A-63-243102 (Patent Document 26) and JP-A-63-243102 (Patent Document 27), an electron donating compound is desirable. Sensitizers suitable for the present invention having such characteristics include aromatic polycyclic compounds, porphyrin compounds, phthalocyanine compounds, polymethine dye compounds, merocyanine compounds, coumarin compounds, thiopyrylium compounds, pyrylium compounds, p-dialkylaminostyryl. Examples thereof include, but are not limited to, compounds and thioxanthene compounds. Many of these include Taiga, Hirashima, Matsuoka, Kitao, “Dye Handbook” (Kodansha) (Non-Patent Document 6), Color Material Association, “Color Material Engineering Handbook”, Asakura Shoten (issued in 1989) Non-Patent Document 7), Hayashibara Biochemical Laboratories Photosensitivity Laboratories “Dye Catalog” (Non-Patent Document 8) and the like.

  Examples of the aromatic polycyclic compound used as a sensitizer include those having a basic skeleton composed of hydrocarbons such as naphthalene, phenanthrene, pyrene, anthracene, tetracene, chrysene, pentacene, picene, coronene, hexacene, and ovalene. it can. In addition, aromatic heterocyclic 5-membered polycyclic compounds such as benzofuran, dibenzofuran, indole, carbazole, benzothiophene, dibenzothiophene, and the like having oxygen atom, nitrogen atom, and sulfur atom as constituent atoms can also be mentioned. Examples of the basic skeleton of the aromatic heterocyclic 6-membered polycyclic compound include α-benzopyrone, β-benzopyrone, α-thiabenzopyrone, β-thiabenzopyrone, flavone, xanthone, thioxanthone, phenoxazine, and phenothiazine. Further, these basic skeletons may be substituted with at least one electron-donating group such as an alkyl group, a hydroxy group, an alkoxy group, and an alkylthio group. Examples of sensitizers composed of substituted aromatic polycyclic compounds include 1-methoxynaphthalene, 1,4-dimethylnaphthalene, 1,8-dimethylnaphthalene, 9,10-dimethylphenanthrene, 9-methylanthracene, 9 , 10-dimethylanthracene, 9,10-diphenylanthracene, 9,10-bis (phenylethynyl) anthracene, 1,8-dimethyl-9,10-bis (phenylethynyl) anthracene, 9,10-dimethoxyanthracene, 9, Examples thereof include 10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene, 2-ethyl-9,10-diethoxyanthracene, and 1-methylpyrene. Examples of the substituted product of the polycyclic heterocyclic compound include N-methylcarbazole, N-ethylcarbazole, thioxanthone, isopropylthioxanthone, and the like.

  Porphyrin compounds include tetraphenylporphine, octaethylporphine, mesoporphyrin, protoporphyrin, hematoporphyrin, chlorin, tetrabenzoporphine, and other basic skeletons and their magnesium complexes, zinc complexes, May include chlorophyll.

  The phthalocyanine compound includes a naphthocyanine compound, and at least one substituent such as an alkyl group, an alkoxy group, an alkylthio group, an aryl group, or a halogen group may be introduced into their basic skeleton. Further, magnesium, zinc, cadmium, and aluminum are particularly preferable as the central metal.

  As the polymethine dye compound, a cyanine type or merocyanine type having a structure in which a heterocyclic ring containing a nitrogen atom, an oxygen atom, a sulfur atom or the like is connected by polymethine can be used. Examples include the dye compounds described in Shin Okawara, Shinjiro Kitao, Kosuke Hiraoka, Ken Matsuoka, “Dye Handbook”, Kodansha Scientific (1986), pages 382 to 417. Specifically, in addition to a cyanine group consisting of a quinoline ring, an indocyanine group consisting of an indole ring, a thiocyanine group consisting of a benzothiazole ring, a polymethine group consisting of an iminocyclohexadiene ring, a benzoxazole system, a pyrylium system, a thiapyrylium system, Examples include squarylium-based and croconium-based.

  As coumarin compounds, there are monocoumarin compounds described in Nobu Okawara, Shinjiro Kitao, Tsuneaki Hiraoka, Ken Matsuoka, “Dye Handbook”, Kodansha Scientific (1986), pages 432 to 438, and 3- (2- Benzothiazolyl) -7- (diethylamino) coumarin, 3- (2-benzothiazolyl) -7- (dibutylamino) coumarin, 3- (2-benzothiazolyl) -7- (dioctylamino) coumarin, 3- (2-benzimidazolyl)- 7- (diethylamino) coumarin, 10- (2-benzothiazolyl) -2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H, 5H, 11H- [1] benzopyrano [6,7 , 8-ij] quinolizin-11-one, 3,3-carbonylbis (7-diethylaminocoumarin), 3,3 And the like carbonyl bis (7-dibutyl-amino coumarin).

  Examples of p-dialkylaminostyryl compounds include 4-diethylaminobenzylideneacetophenone, 4-diethylaminobenzylidene (p-methoxy) acetophenone, 4-diethylaminobenzylidenemalondinitrile, 4-dimethylaminobenzylideneacetoacetic acid ethyl ester, 4-dimethylaminobenzylidenemalon Acid diethyl ester, 4-dimethylaminobenzylidene-α-cyanoacetophenone, 2,6-bis (4-dimethylaminobenzylidene) cyclohexanone, 4-dimethylaminocinnamylideneacetophenone, 4-dimethylaminocinnamylidenemalondinitrile, 4- Dimethylaminocinnamylidene cyanoacetic acid ethyl ester, 4-dimethylaminocinnamylidenemalonic acid diethyl ester, 4-dimethylamino N'namiriden -α- cyanoacetophenone, 4-dimethylamino cinnamylidene - bis (4-dimethylamino benzylidene) cyclohexanone, and the like.

  The absorption wavelength of these spectral sensitizers covers a wide range from ultraviolet to infrared, and not only these alone but also two or more sensitizers can be mixed to efficiently emit light in a wide wavelength range. It can absorb and generate acid.

  Examples of the epoxy compound used in the photosensitive film of the present invention include monofunctional and polyfunctional epoxy monomers. As monofunctional epoxy monomers, pinene oxide, Denacol series EX-111, EX-121, EX-141, EX-145, EX-146, EX-171, EX- described in Nagase ChemteX Corporation catalog 192, EX-111, EX-147, M-1230, EHDG-L, and 100MF, which are Epolite series described in the catalog of Kyoeisha Chemical Co., Ltd., are not limited thereto. If these are used as reactive diluents, high viscosity or solid epoxy resins can be used. For example, the BPF type epoxy resin, BPA type epoxy resin, BPF type epoxy resin, novolak type epoxy resin, brominated epoxy resin, flexible epoxy resin, and Yuka Shell Epoxy Co., Ltd. catalog listed in the catalog of Toto Kasei Co., Ltd. Epicoat basic solid type, Epicoat bis F solid type, EHPE alicyclic solid epoxy resin described in the catalog of Daicel Chemical Industries, Ltd., and the like can be used.

  Examples of the multifunctional glycidyl type epoxy monomer include Denacol series EX-611, EX-612, EX-614, EX-614B, EX-614, EX-622, EX described in the Nagase ChemteX Corporation catalog. -512, EX-521, EX-411, EX-421, EX-313. EX-314, EX-321, EX-201, EX-211, EX-212, EX-252, EX-810, EX-811, EX-850, EX-851, EX-821, EX-830, EX- 832, EX-841, EX-861, EX-911, EX-941, EX-920, EX-721, EX-221, EM-150, EM-101, EM-103, YD described in the catalog of Tohto Kasei Co., Ltd. -115, YD-115G, YD-115CA, YD-118T, YD-127, 40E, 100E, 200E, 400E, 70P, 200P, 400P, 1500NP, 1600, 80MF, which is the Epolite series described in the Kyoeisha Chemical Co., Ltd. catalog , 100MF, 4000, 3002, 1500, and the like. Examples of the alicyclic epoxy monomer include Celoxide 2021, Celoxide 2080, Celoxide 3000, Epolide GT300, Epolide GT400, Epolide D-100ET, Epolide D-100OT, Epolide D-100DT, Epolide D described in the catalog of Daicel Chemical Industries, Ltd. -100ST, epolide D-200HD, epolide D-200E, epolide D-204P, epolide D-210P, epolide D-210P, epolide PB3600, epolide PB4700, etc., but are not limited thereto.

  An oxetane monomer can be added to the epoxy monomer used in the photosensitive film of the present invention. Examples of oxetane monomers include J.M. V. Crivello and H.C. Sasaki, J .; M.M. S. Pure Appl. Chem. A30 (2 & 3), 189 (1993) or J.A. H. Sasaki and V.M. Crivello, J.M. M.M. S. Pure Appl. Chem. , A30 (2 & 3), 915 (1993). Examples include OXT-101, OXT-121, OXT-211, OXT-221, OXT-212, OXT-611, etc. from Toagosei Co., Ltd. These oxetane monomers can be used by mixing with the above epoxy monomers.

Next, the photosensitive transparent film of the present invention comprises an aqueous composition comprising (i) the photoacid generator described above, (ii) a sensitizer used by mixing as necessary, and (iii) an epoxy compound. It is manufactured by coating on a support film and drying.
First, the photosensitive composition necessary for this will be described. When the photoacid generator and the sensitizer and further the epoxy compound is soluble in water, these are dissolved in an aqueous solution of polyvinyl alcohol to prepare a liquid composition. When the cationic photopolymerization initiator and the sensitizer are hardly soluble or insoluble in water, they may be dissolved in a cationic polymerizable monomer that is insoluble or hardly soluble in water and emulsified in an aqueous polyvinyl alcohol solution. . An organic solvent such as ethanol, isopropyl alcohol, ethylene carbonate, propylene carbonate, toluene, or xylene can be used to promote dissolution of the photoacid generator and sensitizer in the cationically polymerizable monomer.

  In the composition for obtaining the photosensitive transparent film of the present invention, the ratio of the photocationic polymerization initiator to 100 parts by weight of polyvinyl alcohol is 12 to 200 parts by weight, preferably 15 to 200 parts by weight, more preferably 18 to 200 parts by weight. When the amount of the cationic photopolymerization initiator added is less than this range, insolubilization of polyvinyl alcohol in water does not occur or insolubilization occurs even when the photosensitive film prepared from the composition is irradiated with light. However, the film is significantly inferior in mechanical and chemical resistance. On the other hand, addition of a photocationic polymerization initiator exceeding the above range does not improve the insolubilization rate.

  Thus, it is thought that the lower limit exists in the addition amount of a photocationic polymerization initiator for the following reasons. That is, the polyvinyl alcohol constituting the composition of the present invention has high hydrophilicity, and therefore moisture cannot be completely removed from the photosensitive film obtained from the composition. For this reason, the cationic polymerization reaction caused by the acid generated by light irradiation is affected by residual moisture.

  The above-mentioned sensitizer can be added to the photoacid generator, but the sensitizer is 5 to 300 parts by weight, preferably 10 to 200 parts by weight, based on 100 parts of the photoacid generator. If it is less than this range, a sufficient sensitizing effect cannot be obtained, and not only the sensitizing effect is not improved beyond this range, but also in the thickness direction of the photosensitive film in order to reduce the light transmittance. Uniform insolubilization does not occur. An epoxy compound is 10-2000 weight part with respect to 100 weight part of polyvinyl alcohol, Preferably it is 20-1000 weight part, More preferably, it is 30-800 weight part. When the addition amount of the cationic polymerizable monomer is less than this range, insolubilization does not occur, and even if it exceeds this range, the insolubilization rate does not improve. On the other hand, exceeding this range is not preferable because the transparency of the resulting film is poor.

  The composition of the present invention may contain an acid-reactive cross-linking agent that causes a dehydration condensation reaction with polyvinyl alcohol in order to utilize the acid catalyst reactivity of the photoacid generator. Examples of the acid-reactive cross-linking agent include N-hydroxymethyl acrylamide, N-hydroxymethylated urea, N-hydroxymethylated malonamide, N-hydroxymethylated phthalimide, hexahydroxymethylated melamine, hexamethoxymethylated melamine, hexabutoxymethyl Melamine, p-hydroxymethylphenol, o-hydroxymethylphenol, 2,6-bis (hydroxymethyl) -p-cresol, resole resin, compound having at least one formyl group or acetal group, more preferably two or more Can be used. A diazo resin may be used in combination as a photocrosslinking agent. Furthermore, extender pigments such as aluminum oxide, silicon oxide, titanium oxide, zinc white and talc, quinacridone pigments, azo pigments, diketopyrrolopyrrole pigments, perylene pigments, phthalocyanine pigments, isoindoline pigments and other organic pigments Can be dispersed and added.

  The aqueous photosensitive resin composition produced in this manner is applied onto various conventionally known supporting films and dried to form a photosensitive film. Examples of the support film in this case include polyester, polyolefin, cellulose acetate, and polyimide. The thickness is (5) to (500) μm, preferably (10) to (200) μm.

  Application | coating to the support film surface of the photosensitive resin composition is performed by the well-known method in which a uniform film is formed. That is, methods such as spin coating, brushing, spraying, reverse roll coating, dip coating, doctor knife coating, and curtain coating. The film thickness depends on the purpose and the type of the substrate, but is an average film thickness of 0.1 μm to 2000 μm, preferably (1.0) to (1000) μm. Water is evaporated and dried from the photosensitive resin layer applied on the support film by a conventionally known method to obtain a photosensitive film. Examples of the drying method include warm air drying and far infrared drying. The photosensitive film is self-supporting because it contains polyvinyl alcohol, but a protective layer comprising a resin film or a resin layer can be provided on the surface.

The photosensitive film of the present invention thus produced has a structure in which a photosensitive layer is laminated on a support film, but exhibits long-term storage stability as compared with a water-dispersible composition. This is probably because the water addition reaction of the epoxy group is suppressed because the amount of water in the film is limited.
Furthermore, the photosensitive film of the present invention has high transparency. The haze degree is 15 or less, preferably 10 or less. It was surprising that a film produced from a water-dispersible photosensitive resin composition containing a poorly water-soluble or water-insoluble epoxy monomer exhibits high transparency. This is presumably because the difference in refractive index between the polyvinyl alcohol and the epoxy monomer is not so large, and the two are partially compatible. Furthermore, the particle diameter of the poorly water-soluble or water-insoluble epoxy monomer system dispersed in water is smaller than that of the corresponding acrylic monomer system, which is considered to improve the transparency of the film. This transparency can suppress light scattering during exposure and also includes an epoxy ring-opening polymerization reaction with small volume shrinkage, so that a relief pattern with excellent resolution can be obtained.

  In order to obtain a stencil for screen printing from the photosensitive film of the present invention, the photosensitive film is pressure-bonded to a screen mesh wetted with an aqueous medium such as water, a water-containing organic solvent, or an aqueous photosensitive resin composition. wear. Next, after the film is dried, pattern exposure is performed and development is performed with water. When the photosensitive film of the present invention is used as an etching photosensitive film such as a dry film resist or a sandblast film, it is similarly wetted with an aqueous medium such as water, a water-containing organic solvent, or an aqueous photosensitive resin composition. A wet lamination method in which the film is pressure-bonded to the substrate surface can be employed. As a result, a resist film that sufficiently follows the irregularities on the surface of the substrate can be provided. The exposed portion of the photosensitive film becomes insoluble in water, but heat treatment may be performed after the exposure to promote insolubilization. The heating temperature depends on the type of the screen and the substrate, but is in the range of room temperature to 200 ° C, preferably room temperature to 100 ° C. The heating time depends on the type of the photosensitive composition and the heating temperature, but is about 30 seconds to 60 minutes. The exposed and optionally heat-treated film is developed with neutral water, but water development involves immersing the photosensitive film in water to dissolve and remove unexposed areas, This is achieved by removing the unexposed portion.

  The photosensitive wavelength region of the photosensitive film affixed to the screen or substrate is determined by the type of sensitizer together with the photoacid generator. Since a wide range of sensitizers can be used, the wavelength range of light ranges from deep ultraviolet to near infrared. Therefore, as a light source, in addition to a low pressure water source lamp, a high pressure mercury lamp, an ultra-high mercury pressure lamp, a xenon lamp, a mercury-xenon lamp, a halogen lamp, a fluorescent lamp, etc., various laser light sources that oscillate ultraviolet rays, visible rays, and near infrared rays. Are preferably used. The exposure may be performed through a photomask or may be performed by writing directly on the photosensitive film with a laser beam. Alternatively, a colored image can be directly drawn on the photosensitive film or the ink receiving film by an inkjet method or the like to obtain a negative image, and then exposure and development can be performed.

  Since the photoinsolubilization of the photosensitive film of the present invention is based on the photocation generation reaction and the cation polymerization reaction, it is not affected by the oxygen in the air and therefore does not require a barrier film. For this reason, there is no reduction in resolution due to the barrier film. Moreover, since it is excellent in transparency, there is no reduction in resolution due to light scattering. Furthermore, since the epoxy compound forms not only cationic polymerization but also a high-density cross-linked structure by acid-catalyzed addition reaction to the hydroxyl group of polyvinyl alcohol, the photo-insolubilized relief image has chemical resistance, water resistance, and solvent resistance. Are better.

  The invention is explained in more detail below by means of examples.

Experimental Examples 1-17
(Preparation of photosensitive composition)
While stirring a 15% by weight aqueous solution of polyvinyl alcohol, a photoacid generator and an epoxy compound were added to obtain a photosensitive composition as a dispersion. The photosensitive compositions thus prepared are summarized in Table 1. The compounds used here are as follows.
As the polyvinyl alcohol, Kuraray K-217 (polymerization degree = 1700, saponification degree = 88%), as the photoacid generator, sulfonium salt photocationic polymerization initiator UVI-6690 manufactured by Dow Chemical, Nippon Soda Iodonium salt -Based cationic photopolymerization initiator (CI-5102), as sensitizer, Nippon Kayaku isopropylthioxanthone (ITX), Kawasaki Kasei 9,10-dibutoxyanthracene (DBA), as epoxy compound, Daicel UCB Celoxide 2021, manufactured by Tohto Kasei ST-3000 and YD-128, EX-622 manufactured by Nagase ChemteX, and the oxetane compound include OXT-221 manufactured by Toagosei. As the acid crosslinking agent, methylolmelamine M-3 manufactured by Sumitomo Chemical Co., Ltd. and Resole Resin Resist Top PL-4668 manufactured by Gunei Chemical Industry Co., Ltd. were used. In addition, 25 parts by weight of FL-GB Blue manufactured by Dainichi Seika Kogyo Co., Ltd. was added to these aqueous photosensitive compositions.
When the particle size of the dispersion composition prepared in Experimental Examples 2, 9 and 17 was repeatedly measured five times with a particle size measuring device MALVERN-HPPS manufactured by Sysmex Corporation, it was in the range of 456 to 797 nm.

Experimental Examples 18-34
(Preparation and storage stability of photosensitive film and photosensitive properties)
The photosensitive composition prepared in Experimental Examples 1 to 17 was applied on a polyester film and dried at 40 ° C. for 15 minutes to obtain a photosensitive film having a film thickness of 25 to 30 μm. The film was irradiated from a distance of 1 meter with a 4 KW ultra-high pressure mercury lamp or a 3 KW halogen lamp through a photomask adhered to the film. Next, it was developed by spraying water with a spray gun. Photosensitivity characteristics were evaluated with ◯ when a 50 μm pattern was faithfully resolved, Δ when a partial defect was found in the pattern, and x when no pattern was formed. These results are summarized in Table 2.

Experimental Example 39 (Reference Example)
(Preparation of photosensitive film-1 from acrylic water-dispersible photosensitive composition)
A water-dispersible photosensitive composition having the following composition was prepared.
15% aqueous solution of partially saponified vinyl acetate polymer (GH-17 manufactured by Nippon Gosei Kagaku): 50 parts polyvinyl acetate polymer (MA-206 manufactured by Hoechst Synthesis) Solid content 50%: 130 parts pentaerythritol triacrylate (Nipponization) Medicinal PET-30): 30 parts diethylthioxanthone (Nippon Kayaku DETX): 1 part isopropyl benzoate (Nippon Kayaku DMBI): 0.5 parts diazodiphenylamine-formaldehyde condensate (Respechemicals DR80) 1 .5 parts This dispersion composition was diluted with water, and the particle size was repeatedly measured 5 times with a particle size measuring device MALVERN-HPPS manufactured by Sysmex Corporation. The result was 2615 to 3397 nm. This composition was applied onto a polyester support film and dried to obtain a 25 μm photosensitive film.

Experimental Example 40 (Reference Example)
(Preparation of photosensitive film-2 from water-dispersible photosensitive composition having photocrosslinkability)
A water-dispersible photosensitive composition having the following composition was prepared.
Photocrosslinking group-added partially saponified vinyl acetate polymer (SPP-H manufactured by Toyo Gosei Co., Ltd.) 15% aqueous solution: 160 parts Polyvinyl acetate polymer (Maechst MA-206): 40 parts pentaerythritol triacrylate (Nippon Kayaku) PET-30): 50 parts Diethylthioxanthone (DETX made by Nippon Kayaku): 2 parts Isopropyl dimethylbenzoate (DMBI made by Nippon Kayaku): 1 part This composition was applied onto a polyester support film and dried to give 25 μm. It was set as the photosensitive film.

Experimental Examples 42-47
(Measurement of haze value of photosensitive film)
In order to know the transparency of the photosensitive film laminated on the polyester film, the haze value was measured using a direct reading haze computer manufactured by Suga Test Instruments. Table 3 summarizes the average values obtained at three different values for the same film.

Experimental Examples 48-65
(Preparation and photosensitivity of film for screen making)
A 250 mesh polyester screen was moistened with water, and then pressure bonded to the photosensitive film prepared in Examples 18 to 34, followed by drying at 40 ° C. to obtain a screen platemaking material. After irradiating from a distance of 1 meter with a 3 KW halogen lamp through a photomask pattern in close contact with the photosensitive layer, it was developed by spraying water with a spray gun to obtain a stencil. Prior to this water development, the photosensitive properties were as follows. The evaluation of the resolution was performed with ◯ when the 20 μm pattern was faithfully resolved, Δ when the pattern was partially broken, and × when the pattern was not obtained at all. Further, while pouring a solvent such as water, acetone, ethyl acetate, butyl cellosolve, etc. on the obtained coating film for plate making, the metal rod whose tip was covered with a cotton cloth was rubbed 100 times with a load of 1 kg. The water resistance and the solvent resistance were evaluated by ◯ marks when no pattern collapse was observed, Δ marks when defects occurred in some patterns, and x marks when pattern collapse was significant. The above results are summarized in Table 4.

Experimental Example 52
(sand blast)
The photosensitive composition obtained in Experimental Example 17 was applied on a polyester support film and laminated as a 50 μm film, which was dried at 40 ° C. for 2 hours to obtain a photosensitive film. After wetting the surface of a glass plate with a thickness of 8 mm with a sponge, the photosensitive film layer was pressure-bonded and pasted and dried at 60 ° C. for 1 hour, and then a photomask was closely attached to the support film, and 1 with a 3 KW halogen lamp. Irradiated from a distance of meters. Subsequently, the polyester film was peeled off and then developed by spraying water with a spray gun, and the unexposed portion was removed to obtain a relay pattern. The glass plate was placed in a sand blasting machine, and blast engraving was performed by spraying an alumina # 80 abrasive under a compressed air pressure of 4 kg / cm ³ . The resin layer of the relief pattern was not peeled off or damaged, and the glass surface coated with the resin layer was not polished at all, and a sandblast image faithful to the photomask was obtained. After the sandblasting, the glass plate was immersed in water, and the resin layer was peeled off.

Experimental Example 53
(Etching of copper-clad laminate)
The photosensitive film obtained in Experimental Example 20 was applied on a copper-clad laminate using paper phenolic resin wetted with water as a substrate, and was dried at 70 ° C. for 30 minutes. After exposure for 4 minutes using a 3 KW halogen lamp through a photomask, the support film was peeled off, developed by spraying water with a spray gun, and a relief pattern was obtained by removing unexposed portions. This was immersed in a 5% ferric chloride aqueous solution at room temperature for etching, washed with water, and then immersed in a 2% sodium periodate aqueous solution for 3 minutes to peel off the resist layer. As a result, a copper pattern faithful to the photomask was obtained.

Claims (6)

Epoxy compound 10 having 12 to 200 weight of photoacid generator and at least one epoxy group that generates Bronsted acid or Lewis acid by the action of active energy rays in an aqueous solution of 100 parts by weight of polyvinyl alcohol having a saponification rate of 60% or more. A photosensitive transparent resin film obtained by laminating a photosensitive resin composition containing a cationically polymerizable oxetane compound in which 2,000 parts by weight are dissolved or dispersed on a support film. Epoxy compound 10 having 12 to 200 weight of photoacid generator and at least one epoxy group that generates Bronsted acid or Lewis acid by the action of active energy rays in an aqueous solution of 100 parts by weight of polyvinyl alcohol having a saponification rate of 60% or more. A photosensitive resin composition containing acid-crosslinked N-methylolated or N-alkoxymethylated nitrogen-containing compound, hydroxymethylated phenol derivative or resole resin , dissolved or dispersed in ~ 2000 parts by weight on a support film A photosensitive transparent resin film characterized by being laminated on. Epoxy compound 10 having 12 to 200 weight of photoacid generator and at least one epoxy group that generates Bronsted acid or Lewis acid by the action of active energy rays in an aqueous solution of 100 parts by weight of polyvinyl alcohol having a saponification rate of 60% or more. Photosensitivity containing cationically polymerizable oxetane compound dissolved in or dispersed in 2000 parts by weight , and acid-crosslinkable N-methylolated or N-alkoxymethylated nitrogen-containing compound, hydroxymethylated phenol derivative or resole resin A photosensitive transparent resin film obtained by laminating a resin composition on a support film.   A screen printing plate comprising the photosensitive transparent film according to any one of claims 1 to 3 wetted with an aqueous medium and attached to a screen mesh.   A stencil for screen printing, wherein the screen printing plate according to claim 4 is irradiated with light, subjected to heat treatment as necessary, and then developed with water.   A photosensitive transparent film for etching, wherein the transparent film according to claim 1 is wetted with an aqueous medium and attached to a substrate.