Hexaarylbisimidazole mixed photoinitiators

Abstract

A 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator contains a compound of formula (I) having a 1-2' bond position and a compound of formula (II) having a 2'-3 bond position, with the combined content of the two compounds accounting for 97% or more of the mixed photoinitiator. When used in photosensitive resin compositions, the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator has excellent photosensitivity and good resolution, and can be widely used in the production of printed circuit boards, protective patterns, conductor patterns, lead wires, semiconductor packages, etc. in the form of dry films and wet films. TIFF2022509242000010.tif64170

Description

[Technical field]

[0001] The present invention relates to the field of organic chemistry, specifically to a 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator, a photosensitive resin composition containing the initiator and its use. [Background technology]

[0002] In recent years, with the miniaturization of printed circuit boards used in precision electronic devices such as personal computers, photosensitive resin compositions with high photosensitivity, high resolution and resolution have become a hotspot of research. As one of the essential components in photosensitive resin compositions, photoinitiators are required to have excellent performance such as high initiation efficiency, good compatibility with the system and good solubility. In radical polymerization systems, hexaarylbisimidazole compounds have a special chemical structure and are photodecomposed by the action of ultraviolet light to generate polymer radicals, making them very important photoinitiators in photosensitive resin compositions.

[0003] Among the hexaarylbisimidazole photoinitiators, 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole (BCIM) is the most widely used. BCIM has many different bond position isomers, and the current commercially available BCIM is basically a mixture of isomers with many different bond positions. The use of BCIM in photosensitive resin compositions reported so far has no further requirements for the composition and content of internal isomers, and the BCIM mixture is simply directly used in the composition. However, the difference in the use performance of BCIM produced by various manufacturers on the market is quite large, which has caused great confusion for younger manufacturers.

[0004] When the inventor's research and development team studied 2,2',5-tris(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenyldiimidazole (TCDM-HABI) and 2,2',4,4'-tetra(o-chlorophenyl)-5,5'-di(3,4-dimethoxyphenyl)diimidazole (TCTM-HABI) in the hexaarylbisimidazole photoinitiator, they unexpectedly discovered that the bond position and the content of photoinitiators with specific bond positions have obvious effects on the photosensitivity of the initiator. Therefore, based on this research, they recognized that investigating the effects of the structure and content of isomers on the performance of BCIM mixed photoinitiators is one of the effective means to further improve the practical use performance of BCIM. Summary of the Invention [Problem to be solved by the invention]

[0005] The performance of BCIM with different bond positions is significantly different, especially in terms of solubility and photosensitivity, and the existing commercially available BCIM has different performance due to its unstable and highly discriminatory components, which affects customer use. The object of the present invention is to address the shortcomings of the prior art by first providing a BCIM mixed photoinitiator containing isomers at specific bond positions. Compared with current BCIM products, the photoinitiator of the present invention has stability, excellent use performance, and obvious advantages in terms of photosensitivity, etc.

[0006] Specifically, the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator of the present invention mainly contains the compound of formula (I) having 1-2' bond position and the compound of formula (II) having 2'-3 bond position, and the total content of the two compounds accounts for more than 97% of the mixed photoinitiator.

[0007] TIFF0007680744000001.tif64170

[0008] Another object of the present invention is to provide a photosensitive resin composition containing the above-mentioned 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator, and the use of this composition in the field of photocuring.

[0009] The 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator of the present invention has excellent photosensitivity and good resolution when used in a photosensitive resin composition, and is widely used in the manufacture of printed circuit boards, protective patterns, conductor patterns, lead wires, semiconductor packages, etc. in the form of dry films and wet films.

[0010] Based on the object of the present invention, each aspect will be described in more detail below.

[0011] <2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator> The 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator of the present invention contains a compound of formula (I) having a 1-2' bond position and a compound of formula (II) having a 2'-3 bond position, and the total content of the two compounds accounts for 97% or more of the mixed photoinitiator.

[0012] TIFF0007680744000002.tif62170

[0013] Furthermore, the total content of the two compounds of the above formulae (I) and (II) accounts for 99% or more of this mixed photoinitiator.

[0014] In the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator of the present invention, the ratio of the compound of formula (I) to the compound of formula (II) is not particularly limited, and the object of the present invention can be achieved as long as the total content of both compounds satisfies the above requirements.

[0015] In addition to the two compounds of formula (I) and (II) above, 2,2'-di(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole (BCIM) also includes isomers of the bond positions such as 1-4', 1-5', 3-4', 3-5', 1-1', 1-3', 3-3', etc., but the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator that meets the structure and content of the present invention can exhibit the best photosensitivity. On the other hand, when the total content of both is less than 97%, the photosensitivity of BCIM tends to be obviously low. The content of the components in the BCIM mixed photoinitiator is detected by high performance liquid chromatography.

[0016] The synthesis method of 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole is a synthesis method of a photoinitiator known in the field of photoresists, and can be prepared by oxidative coupling of substituted triphenylimidazole compounds. Examples of the oxidizing agent used in the reaction include sodium hypochlorite and potassium ferricyanide, and examples of the phase transfer catalyst used include tetrabutylammonium bromide, benzyltriethylammonium chloride, crown ether (15-crown ether-5,18-crown ether-6), polyethylene glycol, and the like. For specific preparation steps, reference can be made to the contents described in the prior art such as US3784557, US4622286, and US4311783 (the entire text of which is incorporated herein by reference). In the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole obtained by the current technical process, the total content of the two compounds of the above formula (I) and (II) accounts for a relatively low proportion in the content of the BCIM mixed photoinitiator, and its impurity components are mainly diimidazole compounds at other bonding positions, so by adding a solvent beating or recrystallization process to the current process, the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator that meets the composition requirements of the present invention can be easily obtained. The solvent can be one or more of toluene, pure benzene, methanol, ethanol, ethyl acetate, dichloromethane, and water.

[0017] <Photosensitive resin composition> The present invention further relates to a photosensitive resin composition containing the above 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator.

[0018] Typically, in addition to the above 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator, the composition further comprises an alkali-soluble polymer, a compound having an ethylenically unsaturated double bond, other photoinitiators and / or sensitizers, and any auxiliary agents.

[0019] Each component will be described in more detail below.

[0020] 2,2'-Bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator In the photosensitive resin composition of the present invention, the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator as a component is as described above.

[0021] In 100 parts by mass of the photosensitive resin composition, the content of the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator is preferably 1-10 parts by mass. In this content range, the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator can exhibit excellent photosensitivity and resolution while also having excellent system compatibility.

[0022] Alkali-soluble polymer The alkali-soluble polymer can provide the photosensitive resin composition with a film-forming function, and any polymer having such properties can be used as the alkali-soluble polymer without any particular limitation.

[0023] For example, the alkali-soluble polymer to be applied may be a (meth)acrylic acid-based polymer, a styrene-based polymer, an epoxy-based polymer, an aliphatic polyurethane (meth)acrylate polymer, an aromatic polyurethane (meth)acrylate polymer, an amide-based resin, an amide epoxy-based resin, an alkyd-based resin, a phenol-based resin, or the like.

[0024] Furthermore, the alkali-soluble polymer can be obtained by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include polymerizable styrene derivatives substituted at the α-position or aromatic ring, such as styrene, vinyltoluene, α-methylstyrene, p-methylstyrene, p-ethylstyrene, and p-chlorostyrene, acrylamide derivatives, such as acrylamide and diacetoneacrylamide, ether derivatives of vinyl alcohol, such as acrylonitrile and vinyl n-butyl ether, (meth)acrylic acid derivatives, such as α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-furyl(meth)acrylic acid, and β-styryl(meth)acrylic acid, alkyl(meth)acrylates, benzyl(meth)acrylates, phenoxyethyl methacrylate, tetrahydrofurfuryl(meth)acrylate, and dimethylaminoethyl(meth)acrylate. Examples of the polymerizable monomer include (meth)acrylates such as ethylhexyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate; maleic acid, maleic anhydride, maleic acid monomethyl, maleic acid monoethyl, and maleic acid monoisopropyl; fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid, N-vinylcaprolactam, and N-vinylpyrrolidone. These polymerizable monomers may be used alone or in combination of two or more.

[0025] Furthermore, from the viewpoint of alkali developability and adhesion, it is preferable to use an alkali-soluble polymer having a carboxyl group.The alkali-soluble polymer having a carboxyl group may be an acrylic acid resin containing (meth)acrylic acid as a monomer unit, which uses (meth)acrylic acid as a monomer unit to introduce a carboxyl group; it may be a copolymer that further contains alkyl (meth)acrylate as a monomer unit in addition to (meth)acrylic acid; it may be a copolymer that further contains polymerizable monomer other than (meth)acrylic acid and alkyl (meth)acrylate as a monomer component (for example, a monomer having an ethylenically unsaturated group) in addition to (meth)acrylic acid.

[0026] Furthermore, the alkali-soluble polymer having a carboxyl group is obtained by radical polymerization of a polymerizable monomer having a carboxyl group with another polymerizable monomer, and in particular, is a (meth)acrylate-based polymer obtained by copolymerizing (meth)acrylate, an ethylenically unsaturated carboxylic acid with another copolymerizable monomer. The (meth)acrylate may be at least one of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, furfuryl (meth)acrylate, and glycidyl (meth)acrylate. The ethylenically unsaturated carboxylic acid is preferably at least one of acrylic acid, methacrylic acid, butenoic acid, maleic acid, fumaric acid, and itaconic acid, and more preferably acrylic acid and / or methacrylic acid. The other copolymerizable monomer is preferably at least one of (meth)acrylamide, n-butyl (meth)acrylate, styrene, vinylnaphthalene, (meth)acrylonitrile, vinyl acetate, vinylcyclohexane, and the like.

[0027] The alkali-soluble polymer may be used alone or in combination of two or more. Examples of the alkali-soluble polymer used in combination of two or more include two or more alkali-soluble polymers composed of different copolymerization components, two or more alkali-soluble polymers having different weight average molecular weights, and two or more alkali-soluble polymers having different dispersities.

[0028] In the photosensitive resin composition of the present invention, the weight average molecular weight of the alkali-soluble polymer is not particularly limited, but considering the mechanical strength and alkali developability comprehensively, the weight average molecular weight is preferably 15000-200000, more preferably 30000-150000, and particularly preferably 30000-120000. If the weight average molecular weight exceeds 15000, the developer resistance after exposure tends to be further improved, and if the weight average molecular weight is less than 200000, the development time tends to be shorter and compatibility with other components such as photoinitiators can be maintained. The weight average molecular weight of the alkali-soluble polymer is measured by gel permeation chromatography (GPC) and obtained by conversion using a calibration curve of standard polystyrene.

[0029] Further, from the viewpoint of good alkali developability, the acid value of the alkali-soluble polymer is preferably 50-300 mgKOH / g, more preferably 50-250 mgKOH / g, further preferably 70-250 mgKOH / g, and particularly preferably 100-250 mgKOH / g. If the acid value of the alkali-soluble resin is less than 50 mgKOH / g, it is difficult to ensure a sufficient development speed, and if it exceeds 300 mgKOH / g, the adhesion is reduced, pattern shorts are likely to occur, and the storage stability of the composition is reduced, and problems such as an increase in viscosity are likely to occur.

[0030] The molecular weight distribution of the alkali-soluble resin [weight average molecular weight (Mw) / number average molecular weight (Mn)] is preferably 1.5 to 6.0, particularly preferably 1.8 to 3.7. When the molecular weight distribution is in the above range, the developing property is excellent.

[0031] The content of the alkali-soluble polymer in the composition is preferably 20 to 70 parts by mass, more preferably 30 to 60 parts by mass, based on 100 parts by mass of the total amount of the photosensitive resin composition. When the content of the alkali-soluble polymer is 20 parts by mass or more, the durability of the photosensitive resin composition to plating treatment, etching treatment, etc. can be improved, and when the content is 70 parts by mass or less, it is advantageous for improving the sensitivity of the photosensitive resin composition.

[0032] Compounds containing ethylenically unsaturated double bonds The compound having an ethylenically unsaturated double bond can promote film formation of the photosensitive resin composition.

[0033] The type of compound having an ethylenically unsaturated double bond is not particularly limited, but may be a photopolymerizable compound having at least one ethylenically unsaturated bond in the molecule. For example, compounds obtained by reacting α,β-unsaturated carboxylic acid with polyol, bisphenol A (meth)acrylate compounds, compounds obtained by reacting α,β-unsaturated carboxylic acid with a glycidyl group-containing compound, urethane monomers such as (meth)acrylate compounds having a urethane bond in the molecule, nonylphenoxyethyleneoxy (meth)acrylate, nonylphenoxyoctaethyleneoxy (meth)acrylate, γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl-phthalate, β-hydroxypropyl-β'-(meth)acryloyloxyethyl-phthalate, phthalic acid compounds, alkyl (meth)acrylates, etc. may be mentioned. These compounds may be used alone or in combination of two or more.

[0034] Examples of compounds obtained by reacting the above-mentioned α,β-unsaturated carboxylic acids with polyols include polyethylene glycol di(meth)acrylates having 2-14 ethyleneoxy groups, polypropylene glycol di(meth)acrylates having 2-14 propyleneoxy groups, polyethyleneoxy-polypropyleneoxyglycol di(meth)acrylates having 2-14 ethyleneoxy groups and 2-14 propyleneoxy groups, trimethylolpropane di(meth)acrylate, trimethylolpropane tris(meth)acrylate, EO-modified trimethylolpropane, etc. Examples of the ethylene glycol mono(meth)acrylate include ethylene glycol mono(meth)acrylate, EO, PO-modified trimethylolpropane tris(meth)acrylate, tetramethylolmethane tris(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, and tripropylene glycol di(meth)acrylate. These compounds may be used alone or in combination of two or more. Here, "EO" refers to ethylene oxide, and the EO-modified compound refers to a compound having a block structure of an oxyethylene group; "PO" refers to propylene oxide, and the PO-modified compound refers to a compound having a block structure of an oxypropylene group.

[0035] Examples of the bisphenol A (meth)acrylate compound include 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloyloxypolyethoxypolypropoxy)phenyl)propane. Examples of the 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane include 2,2-bis(4-((meth)acryloyloxydiethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytriethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytetraethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypentaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyhexaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyheptoethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyoctaethoxy)phenyl)propane, 2 ,2-bis(4-((meth)acryloyloxynonaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxydecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyundecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxydodecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytridecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytetradecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypentadecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyhexadecaethoxy)phenyl)propane, and the like. The number of oxyethylene groups in a single 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane molecule is preferably 4 to 20, more preferably 8 to 15. These compounds may be used alone or in combination of two or more.

[0036] Examples of the (meth)acrylate compound having a urethane bond in the molecule include an addition reaction product of a (meth)acrylic acid monomer having an OH group at the β-position and a diisocyanate compound (e.g., isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1,6-hexamethylene diisocyanate, etc.), tris((meth)acryloyloxytetraethylene glycol isocyanate)hexamethylene isocyanurate, EO-modified urethane di(meth)acrylate, PO-modified urethane di(meth)acrylate, and EO,PO-modified urethane di(meth)acrylate. These compounds may be used alone or in combination of two or more.

[0037] As the above-mentioned nonylphenoxy polyvinyloxy acrylate, for example, nonylphenoxy tetravinyloxy acrylate, nonylphenoxy pentavinyloxy acrylate, nonylphenoxy hexavinyloxy acrylate, nonylphenoxy heptavinyloxy acrylate, nonylphenoxy octavinyloxy acrylate, nonylphenoxy nonavinyloxy acrylate, nonylphenoxy decavinyloxy acrylate, nonylphenoxy undecavinyloxy acrylate can be mentioned.These compounds can be used alone or in combination of two or more kinds.

[0038] Examples of the phthalic acid compound include γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl phthalate and β-hydroxyalkyl-β'-(meth)acryloyloxyalkyl phthalate. These compounds may be used alone or in combination of two or more.

[0039] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, phenyl (meth)acrylate, isobornyl (meth)acrylate, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. acrylate, 2-hydroxypropyl (meth)acrylate, benzyl (meth)acrylate, pentyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isooctyl (meth)acrylate, ethoxylated nonylphenol (meth)acrylate, propylene glycol polypropylene ether di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethoxylated polytetrahydrofuran diol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and the like. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, trimethylolpropane tris(meth)acrylate, ethoxylated trimethylolpropane tris(meth)acrylate, pentaerythritol tris(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexaacrylate are preferred. These compounds may be used alone or in combination of two or more.

[0040] From the viewpoint of improving resolution, plating resistance, and adhesion, the compound having an ethylenically unsaturated double bond is preferably selected from bisphenol A (meth)acrylate compounds and (meth)acrylate compounds having a urethane bond in the molecule. From the viewpoint of improving sensitivity and resolution, bisphenol A (meth)acrylate compounds are preferred. Commercially available bisphenol A (meth)acrylate compounds include, for example, 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane (e.g., Shin-Nakamura Chemical Co., Ltd., BPE-200), polyethoxybisphenol A methacrylate (e.g., Shin-Nakamura Chemical Co., Ltd., BPE-5000; Hitachi Chemical Co., Ltd., FA-321M), 2,2-bis(4-((meth)acryloyloxypolybutoxy)phenyl)propane (e.g., Shin-Nakamura Chemical Co., Ltd., BPE-1300), and the like.

[0041] In 100 parts by mass of the photosensitive resin composition, the content of the compound having an ethylenically unsaturated double bond is preferably 20-50 parts by mass, more preferably 25-45 parts by mass. When the content of the compound having an ethylenically unsaturated double bond is 20 parts by mass or more, the sensitivity and resolution of the photosensitive resin composition are further improved, and when the content is 50 parts by mass or less, the photosensitive resin composition is more easily thinned and the durability against etching treatment is further improved.

[0042] Other photoinitiators and / or sensitizers The photosensitive resin composition further contains other photoinitiators or sensitizers to increase the compatibility, photosensitivity and resolution of the photosensitive resin system through a synergistic effect. The other photoinitiators and / or sensitizers may include (but are not limited to) bisimidazoles, pyrazolines, aromatic ketones, anthraquinones, benzoin and benzoin alkyl ethers, oxime esters, triazines, triphenylamines, coumarins, thioxanthones, acridines and other photoinitiators known to those skilled in the art. These photoinitiators may be used alone or in combination of two or more.

[0043] Examples of the bisimidazole derivatives include 2,2',5-tris(2-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenyl-diimidazole, 2,2',5-tris(2-fluorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenyl-diimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-diimidazole, 2,2'- Bis(2-fluorophenyl)-4-(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-diimidazole, 2,2'-bis(2-fluorophenyl)-4,4',5,5'-tetraphenyl-diimidazole, 2,2'-bis(2-methoxyphenyl)-4,4',5,5'-tetraphenyl-diimidazole, 2,2'-bis(2-chloro-5-nitrophenyl)-4,4'-bis( 3,4-dimethoxyphenyl)-5,5'-bis(2-chlorophenyl)-diimidazole, 2,2'-bis(2-chloro-5-nitrophenyl)-4-(3,4-dimethoxyphenyl)-5-(2-chlorophenyl)-4',5'-diphenyl-diimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4'-bis(3,4-dimethoxyphenyl)-5,5'-bis(2-chlorophenyl)-diimidazole, 2 -(2,4-dichlorophenyl)-4-(3,4-dimethoxyphenyl)-2',5-bis(2-chlorophenyl)-4',5'-diphenyl-diimidazole, 2-(2,4-dichlorophenyl)-2'-(2-chlorophenyl)-4,4',5,5'-tetraphenyl-diimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-diimidazole, and the like. These bisimidazole derivatives may be used alone or in combination of two or more.

[0044] The pyrazoline compound may be, for example, 1-phenyl-3-(4-t-butylstyryl)-5-(4-t-butylphenyl)pyrazoline, 1-phenyl-3-biphenyl-5-(4-t-butylphenyl)pyrazoline, ethoxylated (9) trimethylol pyrazoline ester, ethoxylated (10) bisphenol A pyrazoline ester, and the like. These pyrazoline compounds may be used alone or in combination of two or more.

[0045] Examples of the aromatic ketone derivatives include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, benzophenone, 4-benzoyldiphenyl sulfide, 4-benzoyl-4'-methyldiphenyl sulfide, 4-benzoyl-4'-ethyldiphenyl sulfide, 4-benzoyl-4'-propyldiphenyl sulfide, 4,4'-bis(diethylamino)benzophenone, 4 -p-Toluene mercaptobenzophenone, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(methyl, ethylamino)benzophenone, acetophenone dimethyl ketal, benzil dimethyl ketal, α,α'-dimethylbenzyl ketal, α,α-diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylacetone, 1-hydroxycyclohexylbenzophenone, 2 -Hydroxy-2-methyl-1-p-hydroxyethyl ether phenylacetone, 2-methyl-1-(4-methylmercaptophenyl)-2-morpholine 1-acetone, 2-benzyl-2-dimethylamino-1-(4-morpholinephenyl) 1-butanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-1-{3-[4-(2-hydroxy-2-methyl-propionyl)phenyl}-1-acetone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl-(2-hydroxy-2-propyl)ketone, and the like. These aromatic ketone derivatives may be used alone or in combination of two or more.

[0046] Examples of the anthraquinone derivatives include 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 2,3-dimethylanthraquinone, 2-ethylanthracene-9,10-diethyl ester, 1,2,3-trimethylanthracene-9,10-dioctyl ester, 2-ethylanthracene-9,10-bis(4-chlorobutyric acid methyl ester), 2-(3-((3-ethylanthracene-9,10-bis(4-chlorobutyric acid methyl ester)), and 2-(3-((3-ethylanthracene-9,10-bis(4-chlorobutyric acid methyl ester)). 9,10-diethyl ester, 9,10-dibutoxyanthracene, 9,10-diethoxy-2-ethylanthracene, 9,10-bis(3-chloropropoxy)anthracene, 9,10-bis(2-hydroxyethylmercapto)anthracene, 9,10-bis(3-hydroxy-1-propylmercapto)anthracene, and the like. These anthraquinone derivatives may be used alone or in combination of two or more.

[0047] Benzoin and benzoin alkyl ether derivatives may be, for example, benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, and the like. These benzoin and benzoin alkyl ether derivatives may be used alone or in combination of two or more.

[0048] Examples of the oxime ester derivatives include 1-(4-phenylthiophenyl)-n-octane-1,2-dione-2-benzoic acid oxime ester, 1-(6-(2-methylbenzoyl)-9-ethylcarbazol-3-yl)-ethan-1-one oxime acetate, 1-(6-(2-methylbenzoyl)-9-ethylcarbazol-3-yl)-butan-1-one oxime acetate, 1-(6-(2-methylbenzoyl)-9-ethylcarbazol-3-yl)-prop ... -(6-(2-methylbenzoyl)-9-ethylcarbazol-3-yl)-1-cyclohexyl-methane-1-one oxime acetate, 1-(6-(2-methylbenzoyl)-9-ethylcarbazol-3-yl)-3-cyclopentyl-propan-1-one oxime acetate, 1-(4-phenylthiophenyl)-(3-cyclopentyl)-propane-1,2-dione-2-benzoic acid oxime ester, 1-(4-phenylthiophenyl)-(3-cyclohexyl)-propane-1,2-dione-2-cyclohexyl cyclohexyl carboxylic acid oxime ester, 1-(6-(2-methylbenzoyl)-9-ethylcarbazol-3-yl)-(3-cyclopentyl)-propane-1,2-dione-2-oxime acetate, 1-(6-o-methylbenzoyl-9-ethylcarbazol-3-yl)-(3-cyclopentyl)-propane-1,2-dione-2-benzoic acid oxime ester, 1-(4-benzoyldiphenylsulfide)-(3-cyclopentylacetone)-1-oxime acetate, 1-(6-o-methylbenzoyl -9-Ethylcarbazol-3-yl)-(3-cyclopentylacetone)-1-oxime cyclohexyl carboxylate, 1-(4-benzoyldiphenylsulfide)-(3-cyclopentylacetone)-1-oxime cyclohexyl carboxylate, 1-(6-o-methylbenzoyl-9-ethylcarbazol-3-yl)-(3-cyclopentyl)-propane-1,2-dione-2-o-methylbenzoic acid oxime ester, 1-(4-phenylthiophenyl)-(3-cyclopentyl)-propane-1,2-dione-2-cyclohexyl carboxylic acid oxime ester, 1-(4-thenoyl-diphenylene sulfide-4'-yl)-3-cyclopentyl-propan-1-one oxime acetate, 1-(4-benzoyldiphenyl sulfide)-(3-cyclopentyl)-propane-1,2-dione-2-oxime acetate, 1-(6-nitro-9-ethylcarbazol-3-yl)-3-cyclohexyl-propan-1-one oxime acetate, 1-(6-o-methylbenzoyl-9-ethylcarbazol-3-yl)-3-cyclohexyl Cyl-propan-1-one-oxime acetate, 1-(6-thenoyl-9-ethylcarbazol-3-yl)-(3-cyclohexylacetone)-1-oxime acetate, 1-(6-furfurylformyl-9-ethylcarbazol-3-yl)-(3-cyclopentylacetone)-1-oxime acetate, 1,4-diphenylpropane-1,3-dione-2-oxime acetate, 1-(6-furoyl-9-ethylcarbazol-3-yl)-(3-cyclohexyl)-propane-1,2-dione-2-oxime acetate, 1-(4- 1-(6-Furfurfurylformyl-9-ethylcarbazol-3-yl)-(3-cyclohexylacetone)-1-oxime acetate, 1-(4-phenylthiophenyl)-(3-cyclohexyl)-propane-1,2-dione-3-benzoic acid oxime ester, 1-(6-thenoyl-9-ethylcarbazol-3-yl)-(3-cyclohexyl)-propane-1,2-dione-2-oxime acetate, 2-((benzoyloxy) 1-(4-phenylthiophenyl)-2-(2-methylphenyl)-ethane-1,2-dione-2-oxime acetate, 1-(9,9-dibutyl-7-nitrofluoren-2-yl)-3-cyclohexyl-propan-1-one-oxime acetate, 1-(4-(4-(thiophene-2-formyl)thiophenyl)phenyl)-3-cyclopentylpropane-1,2-dione-2-oxime acetate, 1-(9,9-dibutyl-2-yl)-3-cyclohexylpropylpropane-1,2-dione-2-oxime acetate, 1-(6-(2-(benzoyloxyimino)-3-cyclohexylpropyl-9-ethylcarbazol-3-yl)octane-1,2-dione-2-benzoic acid oxime ester, 1-(7-nitro-9,9-diarylfluoren-2-yl)-1-(2-methylphenyl)methanone-oxime acetate, 1-(6-(2-methylbenzoyl)-9-ethylcarbazol-3-yl)-3-cyclopentadiene 1-(7-(2-methylbenzoyl)-9,9-dibutylfluoren-2-yl)-3-cyclohexylpropane-1,2-dione-2-oxime acetate, 1-(6-(furan-2-formyl)-9-ethylcarbazol-3-yl)-3-cyclohexylpropane-1,2-dione-2-ethoxycarbonyl oxime ester, and the like. These oxime ester derivatives may be used alone or in combination of two or more.

[0049] Examples of triazine derivatives include 2-(4-ethylbiphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4-methyleneoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 3-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}propionic acid, 1,1,1,3,3,3-hexafluoroisopropyl-3-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}propanoic acid ester, ethyl-2-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}acetate, 2-ethoxyethyl-2-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}acetate, cyclohexyl -2-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}acetate, benzyl-2-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}acetate, 3-{chloro-4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}propionic acid, 3-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}propionamide, 2,4-bis(trichloromethyl)-6-p-methoxystyryl-s-triazine, 2,4-bis(trichloromethyl)-6-(1-p-dimethylaminophenyl)-1,3-butadienyl-s-triazine, 2-trichloromethyl-4-amino-6-p-methoxystyryl-s-triazine, and the like. These triazine derivatives may be used alone or in combination of two or more kinds.

[0050] The triphenylamine compound may be, for example, N,N-bis-[4-(2-styryl-1-yl)-phenyl]-N,N-bis(2-ethyl-6-methylphenyl)-1,1-bisphenyl-4,4-diamine, N,N-bis-[4-(2-styryl-1-yl)-4'-methylphenyl]-N,N-bis(2-ethyl-6-methylphenyl)-1,1-bisphenyl-4,4-diamine, and the like. These triphenylamine compounds may be used alone or in combination of two or more.

[0051] The coumarin derivative may be, for example, 3,3'-carbonylbis(7-diethylaminecoumarin), 3-benzoyl-7-diethylaminecoumarin, 3,3'-carbonylbis(7-methoxycoumarin), 7-(diethylamino)-4-methylcoumarin, 3-(2-benzothiazole)-7-(diethylamine)coumarin, 7-(diethylamino)-4-methyl-2H-1-benzopyran-2-one (7-(diethylamino)-4-methylcoumarin), 3-benzoyl-7-methoxycoumarin, and the like. These coumarin derivatives may be used alone or in combination of two or more.

[0052] The thioxanthone derivatives may be, for example, thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, diisopropylthioxanthone, and the like. These thioxanthone derivatives may be used alone or in combination of two or more.

[0053] The acridine derivative may be, for example, 9-phenylacridine, 9-p-methylphenylacridine, 9-m-methylphenylacridine, 9-o-chlorophenylacridine, 9-o-fluorophenylacridine, 2-ethyl-2-(hydroxymethyl)-1,3-propylene glycol ether cycloethane ether [4-(9-acridinyl)phenoxy]acetate, 1,7-bis(9-acridinyl)heptane, 9-ethylacridine, 9-(4-bromophenyl)acridine, 9-(3-chlorophenyl)acridine, 1,7-bis(9-acridinyl)heptane, 1,5-bis(9-acridinpentane), 1,3-bis(9-acridinyl)propane, and the like. These acridine derivatives may be used alone or in combination of two or more.

[0054] In 100 parts by mass of the photosensitive resin composition, the content of the other photoinitiator or sensitizer preferably does not exceed 8 parts by mass.

[0055] Auxiliary Agent In addition to the above components, the photosensitive resin composition of the present invention may optionally contain other auxiliary agents in appropriate amounts as necessary. For example, the auxiliary agent may be a dye such as malachite green, a photocoloring agent such as tribromophenyl sulfone or colorless crystal violet, a pigment, a filler, a plasticizer, a stabilizer, a coating auxiliary agent, a peeling promoter, etc.

[0056] Examples of the dyes, pigments, and photocoloring agents include tris(4-dimethylaminophenyl)methane, tris(4-dimethylamino-2-methylphenyl)methane, fluoran dyes, toluenesulfonic acid monohydrate, alkaline fuchsin, phthalocyanine-based dyes such as phthalocyanine green and phthalocyanine blue, auramine base, paramagienta, crystal violet, methyl orange, Nile Blue 2B, Victoria Blue, malachite green, diamond green, basic blue 20, brilliant green, eosin, ethyl violet, erythrosine sodium B, methyl green, phenolphthalein, alizarin red S, thymolphthaleinphthalein, methyl violet 2B, quinadin red, rose bengal sodium agar, mitanil yellow, Thymolsulfophthalein, xylenol blue, methyl orange, orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein, panmethyl red, Congo red, benzopurpurin 4B, α-naphthyl red, phenacetin, methyl violet, Victoria Pure Blue BOH, rhodamine 6G, diphenylamine, dibenzylphenylamine, triphenylamine, diethylphenylamine, diphenyl-p-phenylenediamine, p-toluidine, benzotriazole, methylbenzotriazole, 4,4'-biphenyldiamine, o-chlorophenylamine, white crystal violet, white malachite green, white phenylamine, white methyl violet, organic pigments such as azo pigments, and inorganic pigments such as titanium dioxide may also be used. In terms of having good contrast, it is preferable to use tris(4-dimethylaminophenyl)methane (i.e., leuco crystal violet, LCV). These dyes, pigments, and photochromic agents may be used alone or in combination of two or more.

[0057] The above-mentioned filler may be, for example, a filler (excluding the above-mentioned inorganic pigments) such as silica, alumina, talc, calcium carbonate, barium sulfate, etc. The filler may be used alone or in combination of two or more kinds.

[0058] Examples of the plasticizer include phthalate esters such as dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, and diallyl phthalate; ethylene glycol esters such as triethylene glycol diacetate and tetraethylene glycol diacetate; sulfonamides such as p-toluenesulfonamide, benzenesulfonamide, and n-butylbenzenesulfonamide; triphenyl phosphate, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylyl phosphate, and tolyldiphenyl phosphate. nyl phosphate, trixylyl phosphate, 2-naphthyl diphenyl phosphate, tolyl bis-2,6-xylyl phosphate, aromatic condensed phosphate ester, tris(chloropropyl) phosphate, tris(tribromoneopentyl) phosphate, halogen-containing condensed phosphate ester, triethylene glycol dicaprylate, bis(2-ethylhexanoic acid) triethylene glycol ester, tetraethylene glycol diheptanoate, diethyl sebacate, dibutyl suberate, tris(2-ethylethyl) phosphate, Brij30 [C 12 H 25 (OCH 2 CH 2 ) 4 OH] and Brij35 [C 12 H 25 (OCH 2 CH 2 ) 20 The plasticizers may be used alone or in combination of two or more.

[0059] Examples of the stabilizer include hydroquinone, 1,4,4-trimethyl-diazobicyclo(3.2.2)-non-2-ene-2,3-dioxide, 1-phenyl-3-pyrazolidinone, p-methyloxyphenol, hydroquinone and quinone substituted with alkyl and aryl, t-butylcatechol, 1,2,3-benzenetriol, resinate, naphthylamine, β-naphthol, cuprous chloride, 2,6-di-t-butyl-p-cresol, phenothiazine, pyridine, nitrobenzene, dinitrobenzene, p-toluoquinone, and chloranil. The stabilizer may be used alone or in combination of two or more.

[0060] Considering safety and versatility, the above coating aid may be acetone, methanol, methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl ethyl ketone, propylene glycol monomethyl ether acetate, ethyl lactate, cyclohexanone, γ-butyrolactone, dichloromethane, etc. The coating aid may be used alone or in combination of two or more kinds.

[0061] The above-mentioned peeling promoter may be, for example, benzenesulfonic acid, toluenesulfonic acid, xylenesulfonic acid, phenolsulfonic acid, alkylbenzenesulfonic acids such as methyl, propyl, heptyl, octyl, decyl, dodecyl, etc. The peeling promoter may be used alone or in combination of two or more kinds.

[0062] The content of the auxiliary agent in 100 parts by mass of the photosensitive resin composition preferably does not exceed 10 parts by mass.

[0063] <Use> The photosensitive resin composition of the present invention can be prepared into a dry film, i.e., in the form of a photosensitive resin laminate, and used to manufacture printed circuit boards, protective patterns, conductor patterns, lead wires, and semiconductor packages, and required patterns can be formed on different substrates through each process.

[0064] The photosensitive resin composition of the present invention can be applied to the corresponding substrate in each corresponding manufacturing step by a wet film coater, that is, it can be used as a wet film to manufacture printed circuit boards, protective patterns, conductor patterns, lead wires, and semiconductor packages, and can form required patterns on different substrates through each process.

[0065] Use of dry film The dry film of the present invention, that is, the photosensitive resin laminate, includes a photosensitive resin layer formed from a photosensitive resin composition, and a support that supports the photosensitive resin layer.

[0066] In general, the preparation of a dry film includes coating a photosensitive resin composition on a support, drying the composition to form a photosensitive resin layer, and optionally attaching a cover film (protective layer) as necessary. The drying conditions are preferably drying at 60-100°C for 0.5-15 minutes. The thickness of the photosensitive resin layer is preferably 5-95 μm, more preferably 10-50 μm, and even more preferably 15-30 μm. If the thickness of the photosensitive resin layer is less than 5 μm, the insulating properties are poor, and if the thickness of the photosensitive resin layer is more than 95 μm, the resolution may decrease.

[0067] Specific examples of the support include various plastic films, such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, cellulose acetate, polyalkyl methacrylate, methacrylate copolymer, polyvinyl chloride, polyvinyl alcohol, polycarbonate, polystyrene, cellophane, vinyl chloride copolymer, polyamide, polyimide, vinyl chloride-vinyl acetate copolymer, polytetrafluoroethylene, polytrifluoroethylene, and the like. In addition, composite materials formed of two or more materials can be used. Preferably, polyethylene terephthalate, which has extremely good light transmittance, is used. The thickness of the support is preferably 5-150 μm, more preferably 10-50 μm.

[0068] The method for applying the photosensitive resin composition is not particularly limited, and for example, a conventional method such as spray coating, drum coating, rotary coating, slit coating, compression coating, curtain coating, dye coating, line coating, knife coating, roll coating, knife coating, spray coating, or dip coating can be used.

[0069] Furthermore, the present invention provides a method for producing a (1) a lamination step of laminating a photosensitive resin laminate onto a copper-clad laminate or a flexible substrate; (2) an exposure step of exposing a photosensitive resin layer in the photosensitive resin laminate to actinic rays in an imagewise manner to photocure the exposed portions; (3) a developing step of removing the unexposed portions of the photosensitive resin layer with a developer to form a protective pattern; (4): A conductive pattern forming process of etching or plating a portion of the surface of the copper-clad laminate or flexible substrate that is not covered by the protective pattern; (5) Use of the dry film in the manufacture of a printed circuit board, comprising a peeling step of peeling a protective pattern from the copper clad laminate or flexible substrate.

[0070] Furthermore, the present invention provides a use of the above-mentioned dry film in the manufacture of a protective pattern, which includes the above-mentioned lamination process, exposure process and development process, with the difference being that in the lamination process, the photosensitive resin laminate can be laminated onto substrates made of various different materials.

[0071] Furthermore, the present invention provides use of the above-mentioned dry film in the manufacture of a conductor pattern, which includes the lamination step, the exposure step, the development step and the conductor pattern forming step as described above, with the difference being that in the lamination step, the photosensitive resin laminate is laminated onto a metal plate or a metal-coated insulating plate.

[0072] Furthermore, the present invention provides use of the above-mentioned dry film in the manufacture of a lead wire, which includes the lamination step, the exposure step, the development step, and the conductor pattern formation step as described above, with the difference being that in the lamination step, the photosensitive resin laminate is laminated onto a metal plate, and in the conductor pattern formation step, the portion not covered by the protective pattern is etched.

[0073] Furthermore, the present invention provides a use of the above-mentioned dry film in the manufacture of a semiconductor package, which includes the above-mentioned lamination process, exposure process, development process, and conductor pattern formation process, with the difference being that in the lamination process, a photosensitive resin laminate is laminated onto a crystal chip having a large-scale integrated circuit, and in the conductor pattern formation process, the parts not covered by the protective pattern are plated.

[0074] Using Wet Film The photosensitive resin composition of the present invention can be directly applied to a substrate in the form of a wet film and used in the manufacture of printed circuit boards, protective patterns, conductor patterns, lead wires, semiconductor packages, and the like.

[0075] The photosensitive resin composition can be applied to a substrate by any of the usual methods, such as roll coating, knife coating, spray coating, dip coating, etc., without any restrictions, and then dried to form a photosensitive resin layer.

[0076] After forming the photosensitive resin layer on the substrate, the subsequent processes, such as an exposure process, a development process, a conductive pattern formation process, and a peeling process, can all be performed with reference to the method of using the dry film.

[0077] Process Step In the exposure step, the exposure may be, for example, a mask exposure method (a method of irradiating active light in an image-wise manner with a negative or positive mask pattern of a wiring pattern) or a projection exposure method, and may also be a method of irradiating active light in an image-wise manner by a direct drawing exposure method such as a laser direct imaging exposure method or a digital optical processing exposure method. As the light source of the active light, a light source that effectively emits ultraviolet light, such as a known light source, for example, a carbon arc lamp, a mercury vapor arc lamp, an ultra-high pressure indicator lamp, a high pressure indicator lamp, a xenon lamp, a gas laser such as an argon gas laser, a solid laser such as a YAG laser, a semiconductor laser, and a gallium nitride blue-violet laser, may be used. In addition, a light source that effectively emits visible light, such as a photographic flood lamp or a fluorescent lamp, may also be used.

[0078] The photosensitive resin composition of the present invention is not particularly limited with respect to the type of light source of actinic rays, but the exposure dose is 10 to 1000 mJ / cm 2 is preferred.

[0079] In the development step, the unexposed portion of the photosensitive resin layer is removed with a developer. When the photosensitive resin layer has a support, the support is first removed using an automatic peeler or the like, and then the unexposed portion is removed using a developer such as an alkaline aqueous solution, an aqueous developer, or an organic solvent. Examples of the alkaline aqueous solution may be, for example, a 0.1-5% by mass sodium carbonate solution, a 0.1-5% by mass potassium carbonate solution, or a 0.1-5% by mass sodium hydroxide solution, and the pH value is preferably 9-11. A surfactant, an antifoaming agent, an organic solvent, or the like may be further added to the alkaline aqueous solution. The development method may be a normal method such as immersion, spraying, or brushing.

[0080] In the etching process, the resist pattern (i.e., protective pattern) formed on the substrate is used as a mask to etch and remove the uncovered conductive layer of the circuit-forming substrate, thereby forming a conductive pattern. The etching method can be selected according to the conductive layer to be removed. Examples of the etching solution include a copper oxide solution, an iron oxide solution, an alkaline etching solution, and a hydrogen peroxide-based etching solution.

[0081] In the plating process, the resist pattern formed on the substrate is used as a mask to plate copper, solder, and the like on the insulating plate of the circuit-forming substrate that is not covered. After the plating process, the resist pattern is removed to form a conductor pattern. The plating process may be performed by electroplating or electroless plating, but electroless plating is preferred. Examples of electroless plating include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-throw solder plating, nickel plating such as Watts bath (nickel sulfate-nickel chloride) plating and nickel sulfamate plating, and gold plating such as hard gold plating and soft gold plating.

[0082] The resist pattern can be removed by using an aqueous solution that is more alkaline than the aqueous solution used in the development step. An example of an aqueous solution that is more alkaline is a 1-10% by mass sodium hydroxide solution. [Brief description of the drawings]

[0083] [Figure 1] FIG. 1 is a high performance liquid chromatographic chart of Comparative Product 1. [Diagram 2] FIG. 2 is a schematic diagram of the structures of two types of binding site compounds in BCIM. [Diagram 3] FIG. 3 is a high performance liquid chromatographic chart of the comparative product 2. [Figure 4] FIG. 4 is a high performance liquid chromatographic chart of the comparative product 3. [Diagram 5] FIG. 5 is a high performance liquid chromatographic chart of Product 1. [Figure 6] FIG. 6 is a high performance liquid chromatographic chart of the product 2. [Figure 7] FIG. 7 is a comparison of sensitometric results for Product 1-2 and Comparative Product 1-3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0084] The present invention will be described in more detail below in combination with specific examples, which should not be construed as limitations on the scope of protection of the present invention.

[0085] 1,2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator 1. Preparation of Examples (1) Preparation of Comparative Product 1 In a 1L four-neck flask, 79g of 2-(2-chlorophenyl)-4,5-diphenylimidazole, 1.2g of acetic acid, 0.5g of tetrabutylammonium bromide and 300g of toluene are poured, heated and stirred, 163g of sodium hypochlorite (11% aqueous sodium hypochlorite solution) is dropped at 60-65℃, the reaction temperature is maintained after the dropping, during the reaction, until the reaction of 2-(2-chlorophenyl)-4,5-diphenylimidazole is completed, sampling is controlled by HPLC, and then the incubation is terminated. After the incubation reaction is completed, the mixture is washed four times with 40g of pure water, and the aqueous layer is extracted once with 20g of toluene. Then, the organic layer obtained by the above extraction is heated to about 65℃ and filtered, and the organic layer after filtration is distilled under reduced pressure to completely precipitate the product, and 50g of pure water is added, stirred, cooled, drained, and dried to obtain 75g of comparative product 1.

[0086] Comparative Product 1 was detected using high performance liquid chromatography and single crystal diffraction. Figure 1 is a high performance liquid chromatographic chart of Comparative Product 1, which shows that the main component of Comparative Product 1 accounts for 82.52% of the total amount.

[0087] The main component of product 1 has only one peak in liquid chromatogram, but the single crystal diffraction analysis of the isolated single main component shows two peak shapes in single crystal diffraction. According to the structural characteristics, the main product of two monoimidazoles is a mixture of the hydrogen-containing N of one imidazole and the C at 2-position of the other imidazole, and the structure shown in Figure 2 is the stereostructure obtained by single crystal diffraction, which can be confirmed to show the two types of binding positions of 1-2' and 2'-3 described in the present invention.

[0088] The main components of the comparative product 1 are compounds with two types of bonding positions, 1-2' and 3-2', and their structural formulas are as follows:

[0089] (I): 2,2'-di(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-diimidazole, and (II): 2,2'-di(o-chlorophenyl)-4,4',5,5'-tetraphenyl-2',3-diimidazole,

[0090] TIFF0007680744000003.tif66170

[0091] The structure was further confirmed by LCMS. Mass spectrometry using the software provided with the instrument gave molecular fragment peaks of 659 and 660, which gave the product a molecular weight of 658, consistent with T+1 and T+2.

[0092] (2) Preparation of Comparative Product 2 It is prepared with reference to the preparation of the comparative product 1 described above, but the difference is that after the comparative product 1 is obtained, a beating treatment is carried out, the beating liquid used is a mixed solution of toluene and water, the ratio of toluene to water is 1:4, and the weight ratio of the beating liquid to product 1 is 1:1. After beating, it is centrifuged, suction filtered and dried to obtain product 2.

[0093] High performance liquid chromatography was used to detect Comparative Product 2. The results show that the main components of Comparative Product 2 (compounds having the structures shown in Formula (I) and Formula (II)) account for 86.18% of the total amount of Comparative Product 2 (see Figure 3).

[0094] (3) Preparation of Comparative Product 3 It is prepared with reference to the preparation of the above comparative product 2, but the difference is that the beating liquid used is methanol, the weight ratio of the beating liquid to product 1 is 1:1, and after beating, it is centrifuged, suction filtered and dried to obtain comparative product 3.

[0095] The detected results show that the main components of Comparative Product 3 (compounds having structures represented by Formula (I) and Formula (II)) account for 92.10% of the total amount of Comparative Product 3 (see Figure 4).

[0096] (4) Preparation of Product 1 It is prepared with reference to the preparation of the above comparative product 1, but the difference is that after obtaining the comparative product 1, a recrystallization process (heating, circulating, stirring, and then cooling and crystallizing) is carried out, the recrystallization solution used is toluene, the weight ratio of the recrystallization solution to product 1 is 1.2:1, and after cooling, centrifugation, rinsing, and drying are carried out to obtain product 1.

[0097] The detected results show that the main component of product 1 (compounds having structures represented by formula (I) and formula (II)) accounts for 97.45% of the total amount of product 1 (see FIG. 5).

[0098] (5) Preparation of Product 2 Prepare with reference to the preparation of product 1 above, but the difference is that the recrystallization solution used is a mixed solvent of toluene and methanol, the ratio of toluene to methanol is 1:1, and the weight ratio of the recrystallization solution to product 1 is 1.2:1. After cooling, centrifuge, suction filter and dry, product 5 is obtained.

[0099] The detected results show that the main component of product 2 (compounds having structures represented by formula (I) and formula (II)) accounts for 99.27% ​​of the total amount of product 2 (see FIG. 6).

[0100] (6) Preparation of Product 3 It is prepared with reference to the preparation of product 1 above, except that the phase transfer catalyst used is 18-crown ether-6, and product 3 is finally obtained.

[0101] The detected results show that the main component of product 3 (compounds having structures represented by formula (I) and formula (II)) accounts for 97.23% of the total amount of product 3.

[0102] (7) Preparation of Comparative Product 4 Prepare with reference to the preparation of Comparative Product 1 above, except that no acetic acid is added, to finally obtain Comparative Product 4.

[0103] The detected results show that the main components of Comparative Product 4 (compounds having structures represented by formula (I) and formula (II)) account for 93.30% of the total amount of Comparative Product 4.

[0104] (8) Preparation of Product 4 It is prepared with reference to the preparation of the above comparative product 4, but the difference is that after the comparative product 4 is obtained, a beating treatment is carried out, the beating liquid used is a mixed solution of toluene and methanol, the ratio of toluene to methanol is 1:1, the weight ratio of the beating liquid to product 1 is 0.6:1, and after beating, centrifugation, suction filtration and drying are carried out to obtain product 4.

[0105] The detected results show that the main component of product 4 (compounds having structures represented by formula (I) and formula (II)) accounts for 98.67% of the total amount of product 4.

[0106] (9) Preparation of Product 5 In a 1L four-neck flask, 79g of 2-(2-chlorophenyl)-4,5-diphenylimidazole, 1.3g of caustic soda flakes, 0.5g of tetrabutylammonium bromide and 300g of toluene are poured, heated and stirred, 156g of sodium hypochlorite (11% aqueous sodium hypochlorite solution) is dropped at 60-65℃, the reaction temperature is maintained after the dropping, during the reaction, until the reaction of 2-(2-chlorophenyl)-4,5-diphenylimidazole is completed, sampling is controlled by HPLC, and then the incubation is terminated. After the incubation reaction is completed, the mixture is washed four times with 40g of pure water, and the aqueous layer is extracted once with 20g of toluene, and then the organic layer obtained by the above extraction is heated to about 65℃ and filtered, and the organic layer after filtration is distilled under reduced pressure until the product precipitates, cooled, drained and dried, and 69g of product 5 is obtained.

[0107] The detected results show that the main component of product 5 (compounds having structures represented by formula (I) and formula (II)) accounts for 99.41% of the total amount of product 5.

[0108] 2. Sensitivity Measurement In order to measure the photosensitivity, the photosensitive resin compositions of Examples 1-2 and Comparative Examples 1-3 are prepared by uniformly mixing each component according to the formulation shown in Table 1. The dosage unit of each component in the table is all g.

[0109] TIFF0007680744000004.tif99170

[0110] In Table 1, TMPTA was purchased from Tianjin Beilian Fine Chemicals Development Co., Ltd., NPG was purchased from Shenzhen Pengshunxing Technology, and PGMEA was purchased from Jinan Huifengda Chemical.

[0111] The sample was prepared according to the above formulation and mixed uniformly, after which 1.0 mg of the sample was taken and spread on the bottom of a crucible, and then placed in the furnace of a differential scanning calorimeter (model number: DSC8000, manufacturer: PerkinElmer) for measurement.

[0112] The peak value indicates the maximum heat release mw / mg; the greater the heat release, the higher the photosensitivity.

[0113] The slope indicates the cure rate; the smaller the slope, the higher the photosensitivity.

[0114] As shown in Figure 7, the photosensitivity measurement results are Comparative Product 1< Comparative Product 2< Comparative Product 3< Product 1< Product 2. The results show that the photosensitivity after using BCIM mixed photoinitiator is closely related to the content of the two compounds of formula (I) and formula (II). With the gradual increase of both ratios in BCIM, the overall photosensitivity is improved accordingly, especially when the content is above 97%, the heat dissipation of BCIM can reach 12mw / mg, which can meet the requirements for the exposure time of dry film.

[0115] The photosensitivity of the photoinitiator determines the exposure time of the dry film, and the exposure time is a very important factor that affects the image of the dry film, if the exposure is insufficient, the polymerization of the resist film is insufficient, and the gum film swells and softens during development, the lines are unclear, the color is dim, and even degumming occurs, if the exposure is too much, development is difficult, the gum film is brittle, and problems such as gum residue occur. Therefore, the total content of the compounds of formula (I) and formula (II) in the BCIM mixed photoinitiator of the present invention is preferably 97% or more, more preferably 99% or more.

[0116] 2. Photosensitive resin composition 1. Preparation 1.1 Preparation of alkali-soluble polymer C1 In a nitrogen gas atmosphere, 500g of a mixed solvent prepared by mixing methyl cellosolve and toluene in a mass ratio of 3:2 is added to a flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel, and the mixture is heated to 80°C while stirring. A solution is prepared by mixing 100g of methacrylic acid, 200g of ethyl methacrylate, 100g of ethyl acrylate, 100g of styrene, and 0.8g of azobisisobutyronitrile, and the solution is slowly dripped into the flask. The dripping time is 4 hours, and the reaction is continued for 2 hours after the dripping. Next, 100g of a mixed solvent (same composition as above) in which 1.2g of azobisisobutyronitrile is dissolved is dripped into the flask. The dripping time is 10 minutes, and the reaction is continued for another 3 hours at 80°C after the dripping, and the temperature is further raised to 90°C and the reaction is continued for another 2 hours. After the reaction is completed, the mixture is filtered to obtain an alkali-soluble polymer C1, which has a weight average molecular weight of about 80,000.

[0117] 1.2 Preparation of photosensitive resin composition A photosensitive resin composition is obtained by uniformly mixing each component according to the formulation shown in Table 2. Unless otherwise specified, all parts shown in Table 2 are parts by mass.

[0118] TIFF0007680744000005.tif130170

[0119] The meanings of the numbers of each component in Table 2 are as shown in Table 3.

[0120] TIFF0007680744000006.tif232170

[0121] 2.Performance evaluation 2.1 Evaluation method Using the dry film method as an example, the performance characteristics of the photosensitive resin compositions shown in the above examples and comparative examples were examined.

[0122] <Preparation of dry film> The photosensitive resin composition is thoroughly stirred and then uniformly applied using a bar coater to the surface of a 25 μm-thick polyethylene terephthalate film support. The composition is then dried in a dryer at 95° C. for 5 minutes to form a 40 μm-thick photosensitive resin layer. Thereafter, a 15 μm-thick polyethylene film is attached as a protective layer to the surface of the photosensitive resin layer on which the polyethylene terephthalate film is not laminated, to obtain a dry film.

[0123] <Substrate surface preparation> A 1.2 mm thick copper-clad laminate having a 35 μm thick rolled copper foil laminate was used as the substrate, and the surface was polished with a wet buff roll (Scotch-Brite (registered trademark) HD#600 manufactured by 3M, passed twice).

[0124] <Layering> The protective layer of polyethylene film is peeled off from the dry film, and then it is laminated to a copper-clad laminate preheated to 60° C. using a hot roll laminator (AL-70 manufactured by Asahi Kasei Corp.) at a roll temperature of 105° C. The gas pressure is 0.35 MPa and the lamination speed is 1.5 m / min.

[0125] <Exposure> A mask is placed on a polyethylene terephthalate film as a support, and exposure is performed using an ultra-high pressure mercury lamp (HMW-201KB manufactured by ORC MANUFACTURING CO., LTD.).

[0126] <Development> The polyethylene terephthalate film was peeled off, and the film was developed using an alkaline developer (a dry film developer manufactured by FujiKiko Co., Ltd.) with 1% by weight Na at 30°C. 2 CO 3 The aqueous solution is sprayed onto the photosensitive resin layer, and the unexposed portions of the photosensitive resin layer are dissolved and removed in a time twice the minimum development time. The minimum development time is the shortest time required for the unexposed portions of the photosensitive resin layer to completely dissolve.

[0127] 2.2 Evaluation Content (1) Compatibility The photosensitive resin composition is thoroughly stirred and the composition is uniformly applied to the surface of a 25 μm thick polyethylene terephthalate film as a support using a bar coater. The composition is dried in a dryer at 95° C. for 5 minutes to form a photosensitive resin layer. Thereafter, the surface of the photosensitive resin layer is visually observed and classified as follows. ◇: The surface is uniform. ◆: Undissolved matter precipitated on the surface.

[0128] (2)Photosensitivity Using a 21-step stepped exposure table manufactured by Stouffer, which has 21 steps of brightness change from transparent to black, the photosensitive resin layer is exposed for 15 minutes and its photosensitivity is evaluated. After exposure, development is performed for twice the minimum development time, and the exposure amount at which the resist film remains completely is classified as follows, with the step exposure table having a series of 8. ○: Exposure amount is 20 mJ / cm 2 The following is the result. ◎: Exposure dose is 20 mJ / cm 2 -50mJ / cm 2 , but excluding the end values. ●: Exposure dose is 50mJ / cm 2 That's all.

[0129] (3)Resolution After exposure and development using an optical mask with a wiring pattern of Line / Space = 10:10-150:150 (unit: μm), the resolution of the dry film is measured. The resolution is the minimum value of the pattern after the unexposed parts of the resist pattern formed by development after exposure are removed. ○: The resolution value is 30 μm or less. ◎: Resolution value is 30 μm-50 μm, excluding end points. ●: Resolution value is 50 μm or greater.

[0130] (4) Hydrophilicity The hydrophilicity is evaluated based on the amount of precipitation after the photosensitive resin layer is dissolved.

[0131] The photosensitive resin composition is thoroughly stirred and uniformly applied to the surface of a 25 μm thick polyethylene terephthalate film as a support using a bar coater. The composition is dried in a dryer at 95° C. for 4 minutes to form a photosensitive resin layer. The layer thickness of the photosensitive resin layer is about 30.5 μm, and the layer weight is about 3.2 g.

[0132] Dissolve 20g of sodium carbonate in 2L of water and add 1.5ml of P1uronic RPG3110 (BASF, Mt. Olive, NJ, this reagent is a polyoxyethylene and polyoxypropylene copolymer plasticizer) to prepare a developer. Place 100g of the above-mentioned film with the photosensitive resin layer in the developer, leave the sample to stand until the resin layer dissolves, and determine the amount of precipitation according to the following scale. 0 = Sediment amount is less than 0.005 g. 1 = A small amount of finely divided pale yellow material is present, weighing 0.005-0.01 g. 5 = A moderate amount of pale yellow material (usually fine) with a sediment weight of 0.05-0.08 g. 10 = The solid layer contains a large amount of pale yellow material (usually flaky) with a precipitate weight of 0.1 g or more.

[0133] (5) Developability After development, the photoresist pattern was observed with a scanning electron microscope (SEM) to evaluate the developability.

[0134] The developability was evaluated according to the following standards: □: No residue was found in the unexposed areas. Δ: A small amount of residue is observed in the unexposed area, but the amount of residue is within the acceptable range. ×: Obvious residues are observed in the unexposed areas.

[0135] 2.3 Evaluation results The evaluation results are as shown in Table 4.

[0136] TIFF0007680744000007.tif46170

[0137] The BCIM mixed photoinitiator of the present invention has excellent compatibility when used in photosensitive resin compositions, and the composition has high photosensitivity, good resolution, hydrophilicity and developability.Compared with the photosensitive resin compositions of Comparative Examples 4-6, the present invention has obvious improvements in photosensitivity, resolution and hydrophilicity.

[0138] The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples. Any other changes, modifications, substitutions, combinations, and simplifications made within the scope of the spirit and principles of the present invention are equivalent replacement methods, and all of them should be included in the protection scope of the present invention.

Claims

1. A 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator containing a compound of formula (I) having a 1-2' bond position and a compound of formula (II) having a 2'-3 bond position, wherein the total content of the two compounds accounts for 97% or more of the total amount of the mixed photoinitiator.

2. The 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator according to claim 1, characterized in that the total content of the two compounds of formula (I) and formula (II) accounts for 99% or more of the mixed photoinitiator.

3. A photosensitive resin composition comprising the 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole mixed photoinitiator according to claim 1 or 2.

4. The photosensitive resin composition according to claim 3, further comprising an alkali-soluble polymer, a compound having an ethylenically unsaturated double bond, other photoinitiators and / or sensitizers, and any auxiliary agents.

5. 5. The photosensitive resin composition according to claim 4, wherein the alkali-soluble polymer is selected from the group consisting of (meth)acrylic acid-based polymers, styrene-based polymers, epoxy-based polymers, aliphatic polyurethane (meth)acrylate polymers, aromatic polyurethane (meth)acrylate polymers, amide-based resins, amide-epoxy-based resins, alkyd-based resins, and phenol-based resins.

6. 6. The photosensitive resin composition according to claim 4, wherein the alkali-soluble polymer is an alkali-soluble polymer having a carboxyl group.

7. 7. The photosensitive resin composition according to claim 6, wherein the alkali-soluble polymer having a carboxyl group is a (meth)acrylate-based polymer copolymerized with (meth)acrylate, an ethylenically unsaturated carboxylic acid, and another copolymerizable monomer.

8. 5. The photosensitive resin composition according to claim 4, wherein the compound having an ethylenically unsaturated double bond is a photopolymerizable compound having at least one ethylenically unsaturated bond in the molecule.

9. 9. The photosensitive resin composition according to claim 4, wherein the compound having an ethylenically unsaturated double bond is selected from a bisphenol A (meth)acrylate compound and a (meth)acrylate compound having a urethane bond in the molecule.

10. The photosensitive resin composition according to claim 4, wherein the other photoinitiator and / or sensitizer is selected from at least one of bisimidazoles, pyrazolines, aromatic ketones, anthraquinones, benzoin and benzoin alkyl ethers, oxime esters, triazines, triphenylamines, coumarins, thioxanthones, and acridine photoinitiators.

11. 5. The photosensitive resin composition according to claim 4, wherein the auxiliary is selected from at least one of dyes, photocolorants, pigments, fillers, plasticizers, stabilizers, coating aids, and peeling promoters.

12. A photosensitive resin laminate comprising a photosensitive resin layer formed from the photosensitive resin composition according to any one of claims 3 to 11, and a support supporting the photosensitive resin layer.

13. Use of the photosensitive resin laminate according to claim 12 in the manufacture of a printed circuit board, a protective pattern, a conductor pattern, a lead wire, or a semiconductor package.

14. Use of the photosensitive resin composition according to any one of claims 3 to 11 in the manufacture of printed circuit boards, protective patterns, conductor patterns, lead wires, and semiconductor packages.

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