JP2014081611A - Photocurable resin composition, print circuit board, and production method of photocurable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable composition enabling obtaining a cured product having good resolution, although comprising a plurality of kinds of filler having different refraction index.SOLUTION: A photocurable composition comprises carboxyl group-containing resin, photoinitiator, and not less than two filler having different refraction index, and the photocurable composition is characterized in that, of the not less than two fillers, not less than one filler is blended as powder, and not less than one filler is blended in slurry state.

Description

  The present invention relates to a photocurable resin composition, a printed wiring board, and a method for producing a photocurable resin composition, and more specifically, the resolution is achieved despite containing multiple types of fillers having different refractive indexes. The present invention relates to a photocurable resin composition capable of obtaining an excellent cured product, a printed wiring board comprising the cured product, and a method for producing the photocurable resin composition.

  In general, in printed wiring boards used in electronic devices, etc., in order to prevent the solder from adhering to unnecessary parts, and to prevent the circuit conductor from being exposed and corroded by oxidation or moisture, A solder resist is formed in a region excluding the connection holes on the formed substrate.

  As one of methods for forming a solder resist having a desired pattern on a substrate, a forming method using a photolithography technique is used. For example, a photosensitive solder resist composed of an alkali-developable photocurable resin composition is exposed through a pattern mask and then alkali-developed, so that the solubility in an alkali developer generated in an exposed area and an unexposed area is obtained. A pattern can be formed using the difference between the two.

  Conventionally, inorganic fillers and organic fillers have been blended into solder resists as one of the means for improving the characteristics of solder resists, such as curing shrinkage suppression, heat resistance, adhesion and hardness (for example, Patent Documents 1 and 2). ). Various fillers have their merits and demerits. In recent years, multiple types of fillers have been added to solder resists for the purpose of improving the workability and performance of solder resists as the density of printed wiring boards increases with the reduction in the thickness and size of electronic equipment. Increasing the effect of the filler by blending has been studied.

JP 2001-053448 A JP 2002-236363 A

  However, when a plurality of types of fillers are blended in the photosensitive solder resist, if the refractive index between the fillers is different, good resolution cannot be obtained, and fine pattern formation may not be possible.

  Accordingly, an object of the present invention is to provide a photocurable resin composition capable of obtaining a cured product with good resolution despite containing a plurality of types of fillers having different refractive indexes, a dry film thereof, It is providing the manufacturing method of the hardened | cured material obtained by hardening | curing, the printed wiring board which comprises the hardened | cured material, and its photocurable resin composition.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a plurality of types of fillers having different refractive indexes in a powder and slurry state, thereby completing the present invention. It came to.

  That is, the photocurable resin composition of the present invention is a photocurable resin composition comprising a carboxyl group-containing resin, a photopolymerization initiator, and two or more kinds of fillers having different refractive indexes. Among the above fillers, one or more kinds of fillers are blended in powder, and one or more kinds of fillers are blended in a slurry state.

The photocurable resin composition of the present invention is a particle size distribution _{D 50} is 3.0μm or _less, it is preferable _{D 90} of at most 8.0 .mu.m.

  In the photocurable resin composition of the present invention, one or more fillers out of the two or more fillers have a refractive index smaller than 1.5 or larger than 1.7, and in a slurry state. It is preferable that it is blended.

  In the photocurable resin composition of the present invention, among the two or more fillers, one or more fillers have a refractive index of 1.5 to 1.7 and are blended in powder form. Is preferred.

  In the photocurable resin composition of the present invention, the carboxyl group-containing resin preferably has an aromatic ring.

  The photocurable resin composition of the present invention preferably contains a carboxyl group-containing resin obtained using a phenol compound as a starting material.

  The dry film of the present invention is obtained by coating and drying any one of the above photocurable resin compositions on a film.

  The printed wiring board of the present invention comprises any one of the above-described photocurable resin compositions or a cured product obtained by curing the dry film by at least one of irradiation with active energy rays and heating. It is characterized by this.

  The method for producing a photocurable resin composition of the present invention is a step of blending two or more fillers having different refractive indexes, one or more fillers in powder, and one or more fillers in a slurry state. It is characterized by including.

  According to the present invention, a photocurable resin composition capable of obtaining a cured product with good resolution despite containing a plurality of types of fillers having different refractive indexes, its dry film, and curing them It is possible to provide a cured product to be obtained, a printed wiring board having the cured product, and a method for producing the photocurable resin composition.

FIG. 1 is a chart showing the results of measuring the particle size distribution of the photocurable resin composition of Example 3 with a laser diffraction / scattering particle size distribution analyzer. FIG. 2 is a chart showing the results of measuring the particle size distribution of a photocurable resin composition (Comparative Example 2) containing only a powder filler using a laser diffraction / scattering particle size distribution measuring apparatus.

  The photocurable resin composition of the present invention is a photocurable resin composition comprising a carboxyl group-containing resin, a photopolymerization initiator, and two or more fillers having different refractive indexes, wherein the two or more types are used. Among the fillers, one or more fillers are blended in powder form, and one or more fillers are blended in a slurry state. Even when two or more kinds of fillers having different refractive indexes are blended, by blending the filler in a slurry state, the transparency of the photocurable resin composition is improved, and a cured product with good resolution is obtained. be able to. Further, by blending one or more fillers in powder form without blending all the fillers in a slurry state, it is possible to suppress an increase in the amount of solvent and deterioration such as dryness and to ensure good workability.

The filler can form aggregates in the photocurable resin composition, but the photocurable resin composition of the present invention has a particle size of aggregates in the composition as compared with the case where the filler is blended only with powder. Becomes smaller. The particle size distribution D ₅₀ of the photocurable resin composition of the present invention is 3.0 μm or less, preferably D ₉₀ is 8.0 μm or less, D ₅₀ is 1.0 μm or less, and D ₉₀ is 3. More preferably, it is 0 μm or less. In this specification, the particle size when the cumulative percentage from the small particle size of the particle size distribution measurement result is 50% is referred to as the particle size distribution D ₅₀ , and the particle size when 90% is the particle size distribution D ₉₀ . The particle size distribution _{D 50} and _{D 90,} for example by using a Nikkiso Co. MT3300EX, can be measured by a laser diffraction scattering method.

  The refractive index of the filler blended in the slurry state is preferably smaller than 1.5 or larger than 1.7. This is because when a filler having such a refractive index is blended with powder, good resolution is often not obtained. This is because such a refractive index has a large difference from the refractive index of the resin of the photocurable resin composition, and the wettability at the interface between the filler and the resin blended in powder is insufficient. This is probably because refraction easily occurs and light scattering easily occurs. When blended in a slurry state, the wettability between the filler and the resin is improved, and light scattering can be suppressed, so that the resolution is considered to be improved. On the other hand, the refractive index of the filler blended with powder is preferably 1.5 to 1.7 since good resolution can be obtained even when blended with powder. Moreover, since the coating film which apply | coated the photocurable resin composition of this invention has low reflectance, it is thought that the filler is disperse | distributed uniformly.

[Carboxyl group-containing resin]
As the carboxyl group-containing resin, various conventionally known carboxyl group-containing resins having a carboxyl group in the molecule can be used. In particular, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond in the molecule is preferable from the viewpoint of photocurability and development resistance. The ethylenically unsaturated double bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. In the case of using only a carboxyl group-containing resin having no ethylenically unsaturated double bond, in order to make the composition photocurable, a compound having a plurality of ethylenically unsaturated groups in the molecule described later, that is, light It is necessary to use a reactive monomer together.
Specific examples of the carboxyl group-containing resin include the following compounds (any of oligomers and polymers).

  (1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid such as (meth) acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene.

  (2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates; carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, polycarbonate polyols, and polyethers A carboxyl group-containing urethane resin by a polyaddition reaction of a diol compound such as a polyol, a polyester-based polyol, a polyolefin-based polyol, an acrylic polyol, a bisphenol A-based alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

  (3) Diisocyanate and bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin ( A carboxyl group-containing photosensitive urethane resin obtained by a polyaddition reaction of (meth) acrylate or a partially acid anhydride-modified product thereof, a carboxyl group-containing dialcohol compound, and a diol compound.

  (4) During the synthesis of the resin of the above (2) or (3), a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate is added, and the terminal ( (Meth) acrylic carboxyl group-containing photosensitive urethane resin.

  (5) During the synthesis of the resin of (2) or (3), one isocyanate group and one or more (meth) acryloyl groups are added in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. A carboxyl group-containing photosensitive urethane resin obtained by adding a compound having a terminal (meth) acrylate.

  (6) Carboxyl group-containing photosensitivity in which (meth) acrylic acid is reacted with a bifunctional or higher polyfunctional (solid) epoxy resin as described later and a dibasic acid anhydride is added to the hydroxyl group present in the side chain. Resin.

  (7) A polyfunctional epoxy resin obtained by epoxidizing a hydroxyl group of a bifunctional (solid) epoxy resin as described later with epichlorohydrin is reacted with (meth) acrylic acid, and a dibasic acid anhydride is added to the resulting hydroxyl group. Added carboxyl group-containing photosensitive resin.

  (8) A dicarboxylic acid such as adipic acid, phthalic acid or hexahydrophthalic acid is reacted with a bifunctional oxetane resin as described later, and the resulting primary hydroxyl group is phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride. A carboxyl group-containing polyester resin to which a dibasic acid anhydride such as

  (9) Reaction product obtained by reacting a compound obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride.

  (10) Obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a reaction product obtained by reacting a cyclic carbonate compound such as ethylene carbonate or propylene carbonate with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting a reaction product with a polybasic acid anhydride.

(11) A carboxyl group-containing photosensitive resin obtained by adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule to the resins (1) to (10).
In addition, in this specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

Since the carboxyl group-containing resin as described above has a large number of carboxyl groups in the side chain of the backbone polymer, development with a dilute alkaline aqueous solution becomes possible.
The acid value of the carboxyl group-containing resin is suitably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the carboxyl group-containing resin is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, when the acid value exceeds 200 mgKOH / g, dissolution of the exposed area by the developer proceeds and the line becomes thinner than necessary. Depending on the case, the exposed portion and the unexposed portion are not distinguished from each other by dissolution and peeling with a developer, which makes it difficult to draw a normal resist pattern.

  Moreover, although the weight average molecular weight of the said carboxyl group containing resin changes with resin frame | skeletons, what is generally in the range of 2,000-150,000, Furthermore, 5,000-100,000 is preferable. When the weight average molecular weight is less than 2,000, tack-free performance may be inferior, the moisture resistance of the coated film after exposure may be poor, film thickness may be reduced during development, and resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be remarkably deteriorated, and storage stability may be inferior.

  The amount of such a carboxyl group-containing resin is 20 to 60% by mass, preferably 30 to 50% by mass in the photocurable resin composition. When the amount of the carboxyl group-containing resin is less than the above range, the coating strength is lowered, which is not preferable. On the other hand, when the amount is larger than the above range, the viscosity of the photocurable resin composition is increased, and the applicability to the carrier film is decreased, which is not preferable.

  These carboxyl group-containing resins are not limited to those listed above, and one kind thereof may be used alone, or a plurality of kinds may be mixed and used. In particular, among the carboxyl group-containing resins, resins having an aromatic ring are preferable because they have a high refractive index and excellent resolution, and those having a novolak structure not only have resolution but also PCT and It is preferable because of excellent crack resistance. Among them, carboxyl group-containing resins synthesized using phenol compounds such as the carboxyl group-containing resins (9) and (10) as starting materials are excellent in HAST resistance and PCT resistance, and in the present invention, low CTE is achieved. And, as a result, excellent crack resistance, it can be suitably used. Such a carboxyl group-containing resin can also be obtained as a resin having no hydroxyl group. In general, the presence of a hydroxyl group has excellent characteristics such as improved adhesion due to hydrogen bonding, but is known to significantly reduce moisture resistance. Specifically, a phenol resin in which a phenol novolac resin is modified with an alkyl oxide is partially acrylated, and an acid anhydride is introduced, thereby providing a double bond equivalent of 300 to 550 and an acid value of 40 to 120 mgKOH / g. In theory, a resin having no hydroxyl group can be easily obtained.

[Photopolymerization initiator]
The photopolymerization initiator is not particularly limited, but includes an oxime ester photopolymerization initiator having an oxime ester group, an α-aminoacetophenone photopolymerization initiator, an acylphosphine oxide photopolymerization initiator, and a titanocene photopolymerization initiator. One or more photopolymerization initiators selected from the group can be preferably used.

  Since the addition amount of the oxime ester-based initiator is small and outgassing is suppressed, it is effective and effective in PCT resistance and crack resistance. The acylphosphine oxide photopolymerization initiator is preferable because it has high deep-part curability since it absorbs at a long wavelength of 400 nm or longer. Further, it is particularly preferable to use an acylphosphine oxide photopolymerization initiator in addition to the oxime ester initiator because a shape with good resolution can be obtained. The titanocene-based photopolymerization initiator is preferable because it has a very wide light absorption wavelength range and is excellent in deep-part curability and has high photoreactivity, so that a small amount of exposure is required for curing and high production is possible.

Examples of the oxime ester photopolymerization initiator include CGI-325, Irgacure OXE01, Irgacure OXE02 manufactured by BASF Japan, N-1919, NCI-831 manufactured by ADEKA, and the like as commercially available products. Moreover, the photoinitiator which has two oxime ester groups in a molecule | numerator can also be used suitably, Specifically, the oxime ester compound which has a carbazole structure represented with the following general formula is mentioned.
(In the formula, X is a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a phenyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms). A group, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms), And Y and Z are each a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, or a carbon number 1). Alkyl group having 1 to 8 alkoxy group, halogen group, phenyl group, phenyl group (alkyl group having 1 to 17 carbon atoms, alkoxy group having 1 to 8 carbon atoms, amino group, alkyl group having 1 to 8 carbon atoms) Group or a dialkylamino group), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or Represents an anthryl group, a pyridyl group, a benzofuryl group, a benzothienyl group, and Ar is a bond or alkylene having 1 to 10 carbon atoms, vinylene, phenylene, biphenylene, pyridylene, naphthylene, thiophene , Anthrylene, thienylene, furylene, 2,5-pyrrole-diyl, 4,4′-stilbene-diyl, 4,2′-styrene-diyl, and n is an integer of 0 or 1.)

  In particular, in the above general formula, X and Y are each a methyl group or an ethyl group, Z is methyl or phenyl, n is 0, and Ar is a bond, phenylene, naphthylene, thiophene or thienylene. It is preferable.

Moreover, the compound which can be represented by the following general formula can also be mentioned as a preferable carbazole oxime ester compound.
(In the formula, R ¹ represents an alkyl group or a nitro group, a halogen atom or a phenyl group which may be substituted with an alkyl group having 1 to 4 carbon atoms having 1 to 4 carbon atoms.
R ² represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may be substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group.
R ³ may be linked with an oxygen atom or a sulfur atom, and may be substituted with an alkyl group having 1 to 20 carbon atoms and an alkoxy group having 1 to 4 carbon atoms which may be substituted with a phenyl group. Represents a good benzyl group.
R ⁴ represents a nitro group or an acyl group represented by X—C (═O) —. X represents an aryl group, a thienyl group, a morpholino group, a thiophenyl group, or a structure represented by the following formula, which may be substituted with an alkyl group having 1 to 4 carbon atoms. )

  In addition, JP-A-2004-359639, JP-A-2005-097141, JP-A-2005-220097, JP-A-2006-160634, JP-A-2008-094770, JP-A-2008-509967, Specific examples include carbazole oxime ester compounds described in JP2009-040762A and JP2011-80036A.

  It is preferable that the compounding quantity of such an oxime ester system photoinitiator shall be 0.01-5 mass parts with respect to 100 mass parts of said carboxyl group-containing resin. If it is less than 0.01 parts by mass, the photocurability on copper is insufficient, and the coating film peels off, and the coating properties such as chemical resistance may deteriorate. On the other hand, when it exceeds 5 parts by mass, light absorption on the surface of the solder resist coating film becomes violent, and the deep curability tends to decrease. More preferably, it is 0.5-3 mass parts.

  As the α-aminoacetophenone photopolymerization initiator, specifically, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N , N-dimethylaminoacetophenone and the like. Examples of commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan.

  Specific examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and bis (2,6-dimethoxy). And benzoyl) -2,4,4-trimethyl-pentylphosphine oxide. Examples of commercially available products include Lucilin TPO and Irgacure 819 manufactured by BASF Japan.

  The blending amount of these α-aminoacetophenone photopolymerization initiator and acylphosphine oxide photopolymerization initiator is preferably 0.01 to 15 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. If it is less than 0.01 parts by mass, the photocurability on copper is insufficient, and the coating film peels off, and the coating properties such as chemical resistance may deteriorate. On the other hand, when the amount exceeds 15 parts by mass, the effect of reducing the outgas cannot be obtained, the light absorption on the surface of the coating film becomes intense, and the deep curability tends to decrease. More preferably, it is 0.5-10 mass parts.

  Specific examples of titanocene photopolymerization initiators include bis (cyclopentadienyl) -di-phenyl-titanium, bis (cyclopentadienyl) -di-chloro-titanium, and bis (cyclopentadienyl) -bis. (2, 3, 4, 5, 6 pentafluorophenyl) titanium, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium and the like. Examples of commercially available products include Irgacure 784 manufactured by BASF Japan.

  It is preferable that the compounding quantity of these titanocene type photoinitiators is 0.01-15 mass parts with respect to 100 mass parts of said carboxyl group-containing resin. When it is less than 0.01 parts by mass, the photocurability on copper is insufficient, the coating film peels off, and the coating properties such as chemical resistance may be deteriorated. On the other hand, if it exceeds 15 parts by mass, the light absorption amount becomes excessively high and the deep curability may be deteriorated. More preferably, it is 0.05-10 mass parts.

  In addition to the photopolymerization initiator, a photoinitiator assistant and a sensitizer can be used in the photocurable resin composition of the present invention. Examples of the photoinitiator and sensitizer that can be suitably used include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds.

  Specific examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

  Specific examples of the acetophenone compound include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, and the like.

  Specific examples of the anthraquinone compound include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, and the like.

  Specific examples of the thioxanthone compound include 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.

  Specific examples of the ketal compound include acetophenone dimethyl ketal and benzyl dimethyl ketal.

  Specific examples of the benzophenone compound include benzophenone, 4-benzoyldiphenyl sulfide, 4-benzoyl-4′-methyldiphenyl sulfide, 4-benzoyl-4′-ethyldiphenyl sulfide, and 4-benzoyl-4′-propyldiphenyl. And sulfides.

  Specifically, as the tertiary amine compound, for example, an ethanolamine compound, a compound having a dialkylaminobenzene structure, such as 4,4′-dimethylaminobenzophenone (Nisso Cure MABP manufactured by Nippon Soda Co., Ltd.), 4, Dialkylaminobenzophenone such as 4′-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.), 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4-methylcoumarin), etc. Dialkylamino group-containing coumarin compounds, ethyl 4-dimethylaminobenzoate (Kayacure EPA, manufactured by Nippon Kayaku Co., Ltd.), ethyl 2-dimethylaminobenzoate (Quantacure DMB, manufactured by International Bio-Synthetics), 4-dimethylamino Nobenzoic acid (n-butoxy) ethyl (Quantacure BEA manufactured by International Bio-Synthetics), p-dimethylaminobenzoic acid isoamyl ethyl ester (Kayacure DMBI manufactured by Nippon Kayaku Co., Ltd.), 2-dimethylhexyl 4-dimethylaminobenzoic acid (Esolol 507 manufactured by Van Dyk).

  Of these, thioxanthone compounds and tertiary amine compounds are preferred. In particular, the inclusion of a thioxanthone compound is preferable from the viewpoint of deep curability. Among them, it is preferable to include a thioxanthone compound such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.

  As a compounding quantity of such a thioxanthone compound, it is preferable that it is 20 mass parts or less with respect to 100 mass parts of said carboxyl group-containing resin. When the blending amount of the thioxanthone compound exceeds 20 parts by mass, the thick film curability is lowered and the cost of the product is increased. More preferably, it is 10 parts by mass or less.

  As the tertiary amine compound, a compound having a dialkylaminobenzene structure is preferable, and among them, a dialkylaminobenzophenone compound, a dialkylamino group-containing coumarin compound having a maximum absorption wavelength in the range of 350 to 450 nm, and ketocoumarins are particularly preferable. .

  As the dialkylaminobenzophenone compound, 4,4'-diethylaminobenzophenone is preferable because of its low toxicity. Dialkylamino group-containing coumarin compounds have a maximum absorption wavelength of 350-410 nm in the ultraviolet region, so they are less colored and use colored pigments as well as colorless and transparent photocurable resin compositions to reflect the color of the colored pigments themselves. It is possible to provide a colored solder resist film. In particular, 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one is preferable because it exhibits an excellent sensitizing effect on laser light having a wavelength of 400 to 410 nm.

  As a compounding quantity of such a tertiary amine compound, it is preferable that it is 0.1-20 mass parts with respect to 100 mass parts of said carboxyl group-containing resin. When the amount of the tertiary amine compound is less than 0.1 parts by mass, a sufficient sensitizing effect tends not to be obtained. On the other hand, when the amount exceeds 20 parts by mass, light absorption on the surface of the dry solder resist coating film by the tertiary amine compound becomes intense, and the deep curability tends to decrease. More preferably, it is 0.1-10 mass parts.

These photopolymerization initiators, photoinitiator assistants, and sensitizers can be used alone or as a mixture of two or more.
The total amount of such photopolymerization initiator, photoinitiator assistant, and sensitizer is preferably 35 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing resin. When it exceeds 35 parts by mass, the deep curability tends to decrease due to light absorption.

[Filler]
Two or more kinds of fillers having different refractive indexes are blended in the photocurable resin composition of the present invention, but the present inventors blended one or more kinds of fillers in powder form among the two or more kinds of fillers. In addition, it has been found that the transparency of the photocurable resin composition is improved and the resolution is improved by blending one or more fillers in a slurry state. Further, a filler having a refractive index smaller than 1.5 or larger than 1.7, preferably a filler having a refractive index larger than 1.3 and smaller than 1.5, or larger than 1.7 is slurry. By blending in a state, higher resolution can be obtained as compared with the case of blending with powder. If the amount of filler added in the slurry state increases, the amount of solvent increases, dryness etc. deteriorates and workability also decreases, but not all fillers are added in the slurry state but also in powder form. Therefore, it is possible to improve the drying property and workability while the resolution is good. Since better resolution is obtained, the refractive index of the filler to be blended with the powder is preferably 1.5 to 1.7, more preferably 1.5 to 1.65. Moreover, since the coating film which apply | coated the photocurable resin composition of this invention has low transmittance | permeability, it is thought that the filler is disperse | distributed uniformly.

In the present invention, the powder is not particularly limited as long as the filler is powdery, and known and conventional ones can be used. In the present invention, the primary particle size means an average primary particle size (D ₅₀ ) and can be measured by a laser diffraction scattering method. Moreover, it is preferable that the total amount of the filler mix | blended with powder is 75% or less of the total amount of all the fillers by mass conversion, and it is more preferable that it is 0.1 to 60%. When the blending amount of the filler exceeds 75% of the total amount of the composition, the viscosity of the insulating composition is increased, the coating and moldability are lowered, and the cured product becomes brittle.

  The slurry state is a state in which the filler is dispersed in a liquid such as water or an organic solvent. Since fillers having a small primary particle size are likely to aggregate when mixed with a liquid, it is preferable to use the filler after filtering through a filter to remove coarse aggregates. In order to remove coarse aggregates, it is preferable to perform filtration through a filter of 10 μm or less, and it is more preferable to perform filtration through a filter of 5 μm or less. The amount of filler in the slurry is preferably 10 to 90%, more preferably 10 to 80%. When it is less than 10%, workability may be deteriorated due to a decrease in viscosity or the like, and when it is more than 90%, dispersion stability as a slurry is low, and aggregation may not be suppressed. It is preferable that the primary particle size of the filler blended in the powder and the filler blended in the slurry state are different. In that case, the filler can be blended with high filling. Since a filler having a small primary particle size is likely to aggregate when it is a powder, it is preferable to add a filler having a primary particle size of 1 μm or less in a slurry state because the filler can be added with higher filling. Moreover, it is preferable that the total amount of the solid content of the filler mix | blended in a slurry state is 10-90% of the total amount of the solid content of all the fillers in terms of mass, and it is more preferable that it is 15-85%. If the amount is less than 10%, the effect of improving the transparency may be low. If the amount is more than 90%, the amount of the solvent in the composition increases, so that the drying property may deteriorate or the filler component may precipitate after storage. .

  Although it does not specifically limit as a liquid mixed with a filler in order to set it as a slurry state, Water, aqueous solution, the organic solvent mentioned later, etc. are mentioned.

  The blending method of the powder and slurry filler is not particularly limited, and may be in the powder and slurry state when mixed with other components such as a carboxyl group-containing resin at the time of blending before preliminary mixing. .

  In the present invention, known and commonly used inorganic fillers and organic fillers can be used as the filler. Inorganic fillers include calcium carbonate, magnesium carbonate, fly ash, dehydrated sludge, natural silica, synthetic silica, kaolin, clay, calcium oxide, magnesium oxide, titanium oxide, zinc oxide, barium sulfate, calcium hydroxide, aluminum hydroxide, Alumina, magnesium hydroxide, talc, mica, hydrotalcite, aluminum silicate, magnesium silicate, calcium silicate, calcined talc, wollastonite, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate, sepiolite, zonolite, boron nitride , Aluminum borate, silica balloon, glass flake, glass balloon, silica, iron slag, copper, iron, iron oxide, carbon black, sendust, alnico magnet, magnetic powder such as ferrite, Cement, glass powder, diatomaceous earth, antimony trioxide, magnesium oxysulfate, hydrated aluminum, hydrated gypsum, alum, and the like. In particular, silica, barium sulfate, talc, hydrotalcite and the like are preferably used.

  Examples of the inorganic filler having a refractive index smaller than 1.5 include silica (refractive index: 1.45), potassium (refractive index: 0.07), and potassium hydrogen carbonate (refractive index: 1.48). Examples of the inorganic filler having a refractive index larger than 1.7 include zinc sulfide (refractive index: 2.37), zirconium oxide (refractive index: 2.4), alumina (refractive index: 1.76), chromium oxide (refractive index). Ratio: 2.5), cadmium oxide (refractive index: 2.49), cadmium sulfide (refractive index: 2.5), zinc oxide (refractive index: 1.95), titanium oxide (refractive index: 2.52-2) .71), iron (refractive index: 2.36), copper oxide (refractive index: 2.71), copper sulfide (refractive index: 1.73), and the like. Inorganic fillers having a refractive index of 1.5 to 1.7 include barium sulfate (refractive index: 1.65), talc (refractive index: 1.54-59), magnesium carbonate (refractive index: 1.57-1). .60), clay (refractive index: 1.55-1.57), aluminum oxide (refractive index: 1.65), aluminum hydroxide (refractive index: 1.65), boehmite (refractive index: 1.62-). 1.65), mica powder (refractive index: 1.59), hydrotalcite (refractive index: 1.50), slaked lime (refractive index: 1.55), calcium hydroxide (refractive index: 1.57), Examples thereof include calcium carbonate (refractive index: 1.58), calcium sulfate (refractive index: 1.59), and potassium carbonate (refractive index: 1.5).

  Examples of the organic filler include polyethylene, polypropylene, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, polycarbonate, crosslinked polymethyl methacrylate, crosslinked polybutyl methacrylate, polyimide, polyamide, polyester, Polyvinyl chloride, polyvinylidene chloride, polydivinylbenzene, fluororesin, polyphenylene oxide, polyphenylene sulfide, polymethylpentene, urea resin, melamine resin, benzoguanamine resin, polyacetal resin, furan resin, silicone resin, cured epoxy resin, etc. In particular, polyethylene, polypropylene, crosslinked polymethyl methacrylate, crosslinked polybutyl methacrylate and the like are preferably used.

  Examples of the organic filler having a refractive index smaller than 1.5 include methyl methacrylate resin (refractive index: 1.49), polymethyl methacrylate (refractive index: 1.49), vinyl acetate resin (refractive index: 1.46). ), Silicone resin (refractive index: 1.43), polyacetal resin (refractive index: 1.48), polypropylene resin (refractive index: 1.48), and the like. Examples of the organic filler having a refractive index larger than 1.7 include a resin for a polythiourethane optical material (refractive index: 1.75). Examples of the organic filler having a refractive index of 1.5 to 1.7 include melamine resin (refractive index: 1.6), nylon (refractive index: 1.53), polystyrene (refractive index: 1.6), polyethylene (refractive index). Rate: 1.53), vinylidene chloride resin (refractive index: 1.61), polycarbonate (refractive index: 1.59), and the like.

  The refractive index of the filler can be measured by the Becke line method. This is a method in which the filler component is placed in the immersion liquid, dropped onto the slide glass, and the cover glass is placed on it, and the Becke line seen at the interface between the filler and the immersion liquid is observed with a narrowed microscope. The refractive index can be measured.

  Moreover, since a filler can be mix | blended with higher filling, if the primary particle size of the filler mix | blended in a slurry state is 1 micrometer or less, since a filler can be mix | blended with higher filling, it is preferable. The lower limit is preferably 0.005 μm or more.

  Examples of the filler having a primary particle size of 1 μm or less include SO-E1 (primary particle size: 0.25 μm), SO-E2 (primary particle size: 0.5 μm), and SO-E3 (primary particle size: 1.0 μm). ), Etc. (all manufactured by Admatechs), B-30 (primary particle size: 0.3 μm), B-31 (primary particle size: 0.3 μm), B-33 (primary particle size: 0.3 μm) ), BF-10 (primary particle size: 0.06 μm), BF-1 (primary particle size: 0.05 μm), BF-20 (primary particle size: 0.03 μm), BF-40 (primary particle size: 0) .01 μm) and the like (all manufactured by Sakai Chemical Co., Ltd.), Hijilite H42 (primary particle size: 1 μm), H42M (primary particle size: 1 μm), H43 (primary particle size: 0.75 μm), Aluminum hydroxide such as H43M (primary particle size: 0.75 μm) DHT-4A (primary particle size: 0.4 μm), DHT-4A-2 (primary particle size: 0.4 μm), DHT-4C (primary particle size: 0.4 μm), DHT-4H (primary particle size) Hydrotalcite (all of which are manufactured by Kyowa Chemical Co., Ltd.) and the like. Among these, barium sulfate is preferable because the particle size is particularly small and the powder is likely to aggregate.

  The total amount of the filler is preferably 500 parts by mass or less, more preferably 0.1 to 300 parts by mass, and particularly preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. When the blending amount of the filler exceeds 500 parts by mass, the viscosity of the photocurable resin composition becomes high and printability may be lowered, or the cured product may become brittle, which is not preferable.

(Photoreactive monomer)
The photocurable resin composition of the present invention may contain a known and commonly used photoreactive monomer. A photoreactive monomer is a compound having one or more ethylenically unsaturated groups in the molecule. The photoreactive monomer assists photocuring of the carboxyl group-containing resin by irradiation with active energy rays.

  Examples of the compound used as the photoreactive monomer include conventionally known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, and epoxy (meth) acrylate. It is done. Specifically, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; N, N-dimethylacrylamide Acrylamides such as N-methylol acrylamide and N, N-dimethylaminopropyl acrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; hexanediol, trimethylolpropane, Polyhydric alcohols such as pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate or the like; Multivalent acrylates such as a peroxide adduct, a propylene oxide adduct, or an ε-caprolactone adduct; a polyvalent such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adduct or propylene oxide adduct of these phenols Acrylates; glyceryl diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyglycerides of glycidyl ether such as triglycidyl isocyanurate; not limited to the above, polyether polyol, polycarbonate diol, hydroxyl-terminated polybutadiene, Polyacrylate polyol and other polyols are directly acrylated or urethane acrylated via diisocyanate Acrylates and melamine acrylates, and at least one of each methacrylate corresponding to the acrylate.

  Further, an epoxy acrylate resin obtained by reacting acrylic acid with a polyfunctional epoxy resin such as a cresol novolac type epoxy resin, or a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate on the hydroxyl group of the epoxy acrylate resin. An epoxy urethane acrylate compound obtained by reacting a half urethane compound may be used as a photoreactive monomer. Such an epoxy acrylate resin can improve photocurability without deteriorating the touch drying property.

  The compounding amount of the compound having an ethylenically unsaturated group in the molecule used as the photoreactive monomer is preferably 5 to 100 parts by mass, more preferably 5 to 100 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. The ratio is 70 parts by mass. When the said compounding quantity is less than 5 mass parts, the photocurability of a photocurable resin composition may fall. On the other hand, when it exceeds 100 mass parts, a coating film may become weak.

(Thermosetting component)
The photocurable resin composition of the present invention may further contain a thermosetting component for the purpose of improving characteristics such as heat resistance and insulation reliability. Examples of thermosetting components include amino resins, isocyanate compounds, blocked isocyanate compounds, maleimide compounds, benzoxazine compounds, oxazoline compounds, carbodiimide compounds, cyclocarbonate compounds, polyfunctional oxetane compounds, episulfide resins, and epoxy resins. A curable resin can be used.

  Examples of the amino resin include amino resins such as melamine derivatives and benzoguanamine derivatives. Examples include methylol melamine compounds, methylol benzoguanamine compounds, methylol glycoluril compounds, and methylol urea compounds. Furthermore, the alkoxymethylated melamine compound, the alkoxymethylated benzoguanamine compound, the alkoxymethylated glycoluril compound and the alkoxymethylated urea compound have the methylol group of the respective methylolmelamine compound, methylolbenzoguanamine compound, methylolglycoluril compound and methylolurea compound. Obtained by conversion to an alkoxymethyl group. The type of the alkoxymethyl group is not particularly limited and can be, for example, a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a butoxymethyl group, or the like. In particular, a melamine derivative having a formalin concentration which is friendly to the human body and the environment is preferably 0.2% or less.

  Examples of commercially available amino resins include Cymel 300, 301, 303, 370, 325, 327, 701, 266, 267, 238, 1141, 272, 202, and the like. 1156, 1158, 1123, 1170, 1174, 1174, UFR65, 300 (above, manufactured by Mitsui Cyanamid Co., Ltd.), Nicalak Mx-750, Mx-032, Mx-270, Mx-280, Mx -290, Mx-706, Mx-708, Mx-40, Mx-31, Ms-11, Mw-30, Mw-30HM, Mw-390, Mw-100LM, Mw -750LM, (manufactured by Sanwa Chemical Co., Ltd.) and the like.

  As the isocyanate compound, a polyisocyanate compound having a plurality of isocyanate groups in the molecule can be used. As the polyisocyanate compound, for example, aromatic polyisocyanate, aliphatic polyisocyanate or alicyclic polyisocyanate is used. Specific examples of the aromatic polyisocyanate include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m- Examples include xylylene diisocyanate and 2,4-tolylene dimer. Specific examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate), and isophorone diisocyanate. Specific examples of the alicyclic polyisocyanate include bicycloheptane triisocyanate. In addition, adduct bodies, burette bodies, and isocyanurate bodies of the isocyanate compounds listed above may be mentioned.

  The blocked isocyanate group contained in the blocked isocyanate compound is a group in which the isocyanate group is protected by reaction with a blocking agent and temporarily deactivated. When heated to a predetermined temperature, the blocking agent is dissociated to produce isocyanate groups.

  As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent is used. Examples of the isocyanate compound that can react with the blocking agent include isocyanurate type, biuret type, and adduct type. As an isocyanate compound used in order to synthesize | combine a block isocyanate compound, aromatic polyisocyanate, aliphatic polyisocyanate, or alicyclic polyisocyanate is mentioned, for example. Specific examples of the aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate include the compounds exemplified above.

  Examples of the isocyanate blocking agent include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-palerolactam, γ-butyrolactam and β-propiolactam; Active methylene blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl Ether, methyl glycolate, butyl glycolate, diacetone alcohol, lactic acid And alcohol-based blocking agents such as ethyl lactate; oxime-based blocking agents such as formaldehyde oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, cyclohexane oxime; butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, Mercaptan block agents such as methylthiophenol and ethylthiophenol; Acid amide block agents such as acetic acid amide and benzamide; Imide block agents such as succinimide and maleic imide; Amines such as xylidine, aniline, butylamine and dibutylamine Blocking agents; imidazole blocking agents such as imidazole and 2-ethylimidazole; imine blocking agents such as methyleneimine and propyleneimine It is.

  The block isocyanate compound may be commercially available, for example, Sumidur BL-3175, BL-4165, BL-1100, BL-1265, Desmodur TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117. , Desmotherm 2170, Desmotherm 2265 (above, Sumitomo Bayer Urethane Co., Ltd., trade name), Coronate 2512, Coronate 2513, Coronate 2520 (above, Nihon Polyurethane Industry Co., Ltd., trade name), B-830, B-815, B- 846, B-870, B-874, B-882 (above, Mitsui Takeda Chemicals, trade name), TPA-B80E, 17B-60PX, E402-B80T (above, Asahi Kasei Chemicals, trade name), etc. Can be mentioned. Sumijoules BL-3175 and BL-4265 are obtained using methyl ethyl oxime as a blocking agent.

  The compounding amount of the polyisocyanate compound or the blocked isocyanate compound is preferably 1 to 100 parts by mass, more preferably 2 to 70 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. When the amount is less than 1 part by mass, sufficient toughness of the coating film may not be obtained, which is not preferable. On the other hand, when the amount exceeds 100 parts by mass, the storage stability may decrease, which is not preferable.

  A urethanization catalyst can be further added to the photocurable resin composition of the present invention. As the urethanization catalyst, it is preferable to use one or more urethanization catalysts selected from the group consisting of tin-based catalysts, metal chlorides, metal acetylacetonate salts, metal sulfates, amine compounds and amine salts.

  Examples of the tin catalyst include organic tin compounds such as stannous octoate and dibutyltin dilaurate, and inorganic tin compounds.

  Examples of the metal chloride include metal chlorides selected from the group consisting of Cr, Mn, Co, Ni, Fe, Cu, and Al. For example, cobalt chloride, nickel chloride, ferric chloride, and the like. Can be mentioned.

  The metal acetylacetonate salt is a metal acetylacetonate salt selected from the group consisting of Cr, Mn, Co, Ni, Fe, Cu and Al. For example, cobalt acetylacetonate, nickel acetylacetonate, iron acetyl Examples include acetonate.

  Examples of the metal sulfate include a metal sulfate selected from the group consisting of Cr, Mn, Co, Ni, Fe, Cu, and Al. Examples thereof include copper sulfate.

  Examples of the maleimide compound include polyfunctional aliphatic / alicyclic maleimide and polyfunctional aromatic maleimide. Examples of the polyfunctional aliphatic / alicyclic maleimide include N, N′-methylene bismaleimide, N, N′-ethylene bismaleimide, tris (hydroxyethyl) isocyanurate, and aliphatic / alicyclic maleimide carboxylic acid. Isocyanurate skeletal polymide compounds such as isocyanurate skeleton maleimide urethane compounds obtained by urethanization of tris (carbamate hexyl) isocyanurate and aliphatic / alicyclic maleimide alcohols. Maleimides; isophorone bisurethane bis (N-ethylmaleimide), triethylene glycol bis (maleimide ethyl carbonate), aliphatic / alicyclic maleimide carboxylic acid and various aliphatic / alicyclic polyols, or dehydrated ester or fat Aliphatic / alicyclic polymaleimide compounds obtained by transesterification of aliphatic / alicyclic maleimide carboxylic acid esters with various aliphatic / alicyclic polyols; aliphatic / alicyclic maleimide carboxylic acids and various types Aliphatic / alicyclic polymaleimide ester compounds obtained by ether ring-opening reaction of aliphatic / alicyclic polyepoxides, urethanes of aliphatic / alicyclic maleimide alcohols and various aliphatic / alicyclic polyisocyanates Aliphatic / alicyclic polymaleimide urethane compounds obtained by the conversion reaction.

  As the polyfunctional aromatic maleimide, aromatic polymaleimide ester compounds obtained by dehydrating esterification of maleimide carboxylic acid and various aromatic polyols, or transesterification reaction of maleimide carboxylic acid ester and various aromatic polyols, maleimide Of aromatic polymaleimide ester compounds obtained by ether ring-opening reaction of carboxylic acid and various aromatic polyepoxides, aromatic polymaleimide urethane compounds obtained by urethanization reaction of maleimide alcohol and various aromatic polyisocyanates And aromatic polyfunctional maleimides.

  Specific examples of the polyfunctional aromatic maleimide include, for example, N, N ′-(4,4′-diphenylmethane) bismaleimide, N, N′-2,4-tolylene bismaleimide, N, N′-2, 6-tolylene bismaleimide, 1-methyl-2,4-bismaleimide benzene, N, N′-m-phenylene bismaleimide, N, N′-p-phenylene bismaleimide, N, N′-m-toluylene Bismaleimide, N, N′-4,4′-biphenylenebismaleimide, N, N′-4,4 ′-[3,3′-dimethyl-biphenylene] bismaleimide, N, N′-4,4′- [3,3′-dimethyldiphenylmethane] bismaleimide, N, N′-4,4 ′-[3,3′-diethyldiphenylmethane] bismaleimide, N, N′-4,4′-diphenylmethane bismale N, N′-4,4′-diphenylpropane bismaleimide, N, N′-4,4′-diphenyl ether bismaleimide, N, N′-3,3′-diphenylsulfone bismaleimide, N, N ′ -4,4'-diphenylsulfone bismaleimide, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-t-butyl-4- (4-maleimidophenoxy) phenyl ] Propane, 2,2-bis [3-s-butyl-4- (4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] decane, 1,1-bis [2-Methyl-4- (4-maleimidophenoxy) -5-t-butylphenyl] -2-methylpropane, 4,4′-cyclohexylidene-bis [1- (4 Maleimidophenoxy) -2- (1,1-dimethylethyl) benzene], 4,4′-methylene-bis [1- (4-maleimidophenoxy) -2,6-bis (1,1-dimethylethyl) benzene] 4,4′-methylene-bis [1- (4-maleimidophenoxy) -2,6-di-s-butylbenzene], 4,4′-cyclohexylidene-bis [1- (4-maleimidophenoxy) -2-cyclohexylbenzene, 4,4′-methylenebis [1- (maleimidophenoxy) -2-nonylbenzene], 4,4 ′-(1-methylethylidene) -bis [1- (maleimidophenoxy) -2,6 -Bis (1,1-dimethylethyl) benzene], 4,4 '-(2-ethylhexylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4'-(1 -Methylheptylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4′-cyclohexylidene-bis [1- (maleimidophenoxy) -3-methylbenzene], 2,2-bis [4 -(4-maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4- Maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3,5-dimethyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3,5-dimethyl-4- (4- Maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-ethyl-4- (4-maleimidophenoxy) phenyl] propa 2,2-bis [3-ethyl-4- (4-maleimidophenoxy) phenyl] hexafluoropropane, bis [3-methyl- (4-maleimidophenoxy) phenyl] methane, bis [3,5-dimethyl- ( 4-maleimidophenoxy) phenyl] methane, bis [3-ethyl- (4-maleimidophenoxy) phenyl] methane, 3,8-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5.2.1. 02,6] decane, 4,8-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5.2.1.02,6] decane, 3,9-bis [4- (4-maleimidophenoxy) ) Phenyl] -tricyclo [5.2.1.02,6] decane, 4,9-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5 2.1.02,6] decane, 1,8-bis [4- (4-maleimidophenoxy) phenyl] menthane, 1,8-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] menthane, Examples include 1,8-bis [3,5-dimethyl-4- (4-maleimidophenoxy) phenyl] menthane.

  Examples of commercially available maleimide compounds include BMI-1000, BMI-1000H, BMI-1000S, BMI-1100, BMI-1100H, BMI-2000, BMI-2300, BMI-3000, BMI-3000H, BMI-4000, Examples thereof include BMI-5100, BMI-7000, BMI-7000H, BMI-TMH (manufactured by Daiwa Kasei Kogyo Co., Ltd.), MIA-200 (manufactured by DIC), and the like.

  These bismaleimide derivatives may be synthesized by conventional methods, or commercially available products may be used. In particular, among the bismaleimide derivatives, those that do not contain a halogen atom in the molecule are preferable from the viewpoint of not placing a burden on the environment. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the benzoxazine compound include bisphenol A type benzoxazine, bisphenol F type benzoxazine, and bisphenol S type benzoxazine. Examples of these commercially available products include “F-a” (manufactured by Shikoku Kasei Co., Ltd.).

  The oxazoline compound is not particularly limited as long as it contains an oxazoline group. Examples of these commercially available products include K-2010E, K-2020E, K-2030E, WS-500, WS-700, and RPS-1005 of Epocross (manufactured by Nippon Shokubai Co., Ltd.).

  Examples of the carbodiimide compound include dicyclohexylcarbodiimide and diisopropylcarbodiimide.

  The cyclocarbonate compound is not particularly limited as long as it is a cyclic compound and has a carbonate bond. Examples include alkylene carbonate compounds having a polyfunctional structure.

  Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3-methyl -3-Oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) In addition to polyfunctional oxetanes such as methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, oxetane alcohol and novolak resin, Poly (p-hydroxystyrene), cardo-type bisphenol Le ethers, calixarenes, calix resorcin arenes, or the like ethers of a resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.

  Examples of the episulfide resin include YL7000 (bisphenol A type episulfide resin) manufactured by Mitsubishi Chemical Corporation and YSLV-120TE manufactured by Tohto Kasei Co., Ltd. Moreover, episulfide resin etc. which replaced the oxygen atom of the epoxy group of the novolak-type epoxy resin with the sulfur atom using the same synthesis method can be used.

  As said epoxy resin, the well-known and usual polyfunctional epoxy resin which has at least 2 epoxy group in 1 molecule can be used. The epoxy resin may be liquid or may be solid or semi-solid.

Examples of epoxy resins include jER828, jER834, jER1001, and jER1004 manufactured by Mitsubishi Chemical Corporation, Epicron 840, Epicron 850, Epicron 1050, Epicron 2055, Epoto YD-011, YD-013 manufactured by Tohto Kasei Co., Ltd. YD-127, YD-128, D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.E. E. R. 664, Sumitomo Epoxy ESA-011, ESA-014, ELA-115, ELA-128, manufactured by Sumitomo Chemical Co., Ltd., A.A. E. R. 330, A.I. E. R. 331, A.I. E. R. 661, A.I. E. R. Bisphenol A type epoxy resin such as 664 (all trade names); jERYL903 manufactured by Mitsubishi Chemical, Epicron 152, Epicron 165 manufactured by DIC, Epototo YDB-400, YDB-500 manufactured by Tohto Kasei Co., Ltd., manufactured by Dow Chemical Of D. E. R. 542, Sumitomo Epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Co., Ltd., A.A. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (both trade names); jER152 and jER154 manufactured by Mitsubishi Chemical Corporation, and D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865 manufactured by DIC, Epototo YDCN-701, YDCN-704 manufactured by Tohto Kasei Co., Ltd., EPPN-201, EOCN-1025, EOCN manufactured by Nippon Kayaku Co., Ltd. -1020, EOCN-104S, RE-306, NC-3000, Sumitomo Epoxy ESCN-195X, ESCN-220, manufactured by Sumitomo Chemical Co., Ltd., A.C. E. R. ECN-235, ECN-299, YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-704 YDCN- manufactured by Nippon Steel Chemical Co., Ltd. Novolak type epoxy resins such as 704A, Epicron N-680, N-690, N-695 (all trade names) manufactured by DIC; Epicron 830 manufactured by DIC, jER807 manufactured by Mitsubishi Chemical Co., Ltd. Bisphenol F type epoxy resin such as YDF-170, YDF-175, YDF-2004, etc. (all trade names); water such as Epototo ST-2004, ST-2007, ST-3000 (trade names) manufactured by Tohto Kasei Co., Ltd. Bisphenol A type epoxy resin; jER604 manufactured by Mitsubishi Chemical Corporation, Epototo YH-434 manufactured by Toto Kasei Co., Ltd. Sumitomo Chemical Co., Ltd. Sumi-epoxy ELM-120 etc. (all trade names) glycidylamine type epoxy resin; Hydantoin type epoxy resin; Daicel Chemical Industries Ltd. Celoxide 2021 grades (all trade names) Epoxy resin; YL-933 manufactured by Mitsubishi Chemical Co., Ltd., T.W. manufactured by Dow Chemical Co., Ltd. E. N. , EPPN-501, EPPN-502, etc. (all trade names) trihydroxyphenylmethane type epoxy resin; Mitsubishi Chemical Corporation YL-6056, YX-4000, YL-6121 (all trade names) Type or biphenol type epoxy resin or a mixture thereof; Nippon Kayaku EBPS-200, ADEKA EPX-30, DIC EXA-1514 (trade name) and other bisphenol S type epoxy resins; Bisphenol A novolac type epoxy resin such as jER157S (trade name); tetraphenylolethane type epoxy resin such as jERYL-931 (all trade name) made by Mitsubishi Chemical; TEPIC made by Nissan Chemical Industries (all) Product name) heterocyclic epoxy resin; diglycid such as NOF's Bremer DGT Phthalate resin; Tetraglycidylxylenoylethane resin such as ZX-1063 manufactured by Tohto Kasei Co., Ltd .; ESN-190, ESN-360 manufactured by Nippon Steel Chemical Co., Ltd., HP-4032 manufactured by DIC, EXA-4750, EXA-4700, etc. Naphthalene group-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC; glycidyl methacrylate copolymer epoxy resin such as CP-50S and CP-50M manufactured by NOF; Examples include, but are not limited to, copolymerized epoxy resins of cyclohexylmaleimide and glycidyl methacrylate; CTBN-modified epoxy resins (for example, YR-102 and YR-450 manufactured by Tohto Kasei Co., Ltd.) and the like. Among these, bisphenol A type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, biphenol type epoxy resin or a mixture thereof is preferable.
These epoxy resins may be used individually by 1 type, and may be used in combination of 2 or more type.

(Thermosetting catalyst)
When it contains the said thermosetting component, it is preferable to contain a thermosetting catalyst further. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Examples include amines, amine compounds such as 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., and U-CAT (registered by San Apro). Trademarks) 3503N, U-CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. In particular, it is not limited to these, as long as it promotes the reaction between the epoxy resin or oxetane compound thermosetting catalyst, or at least one of the epoxy group and oxetanyl group, and the carboxyl group, one type alone. It may be used and may be used as a mixture of two or more. Also, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine and isocyanuric acid adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine and isocyanuric acid adducts can also be used. A compound that also functions in combination with the thermosetting catalyst.

  The blending amount of the thermosetting catalyst is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15.0 parts by mass with respect to 100 parts by mass of the thermosetting component.

(Coloring agent)
The photocurable resin composition of this invention can mix | blend a coloring agent. As the colorant, conventionally known colorants such as red, blue, green and yellow can be used, and any of pigments, dyes and dyes may be used. Specific examples include color index (CI; issued by The Society of Dyer's and Colorists) number. However, it is preferable that the colorant does not contain a halogen from the viewpoint of reducing environmental burden and affecting the human body.

Red colorant:
Examples of the red colorant include monoazo, diazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone.

Blue colorant:
Blue colorants include phthalocyanine-based and anthraquinone-based compounds, and pigment-based compounds include pigments. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Green colorant:
Similarly, the green colorant includes phthalocyanine, anthraquinone, and perylene, and metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Yellow colorant:
Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone.

  In addition, a colorant such as purple, orange, brown, or black may be added for the purpose of adjusting the color tone.

(Organic solvent)
In the above photocurable resin composition, an organic solvent is added for the preparation of the resin composition, for preparing the filler in a slurry state, and for adjusting the viscosity for application to a substrate or a carrier film. Can be used.

  Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl Glycol ethers such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, diethylene glycol monoethyl ether acetate (carbitol acetate), dipropylene glycol methyl ether acetate, Propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene Esters such as glycol butyl ether acetate; Alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; Aliphatic hydrocarbons such as octane and decane; Petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha Etc. Such an organic solvent may be used individually by 1 type, and may be used as a 2 or more types of mixture.

(Other optional ingredients)
The photocurable resin composition of the present invention may further contain components such as an elastomer, a mercapto compound, an adhesion promoter, a block copolymer, an antioxidant, and an ultraviolet absorber as necessary. As these, those known in the field of electronic materials can be used. In addition, the photocurable resin composition of the present invention includes known and commonly used thickeners such as finely divided silica, hydrotalcite, organic bentonite, and montmorillonite, antifoaming agents such as silicone, fluorine, and polymer, and leveling. Known and commonly used additives such as imidazole, thiazole and triazole silane coupling agents, rust preventives and the like can be blended.

  The photocurable resin composition of the present invention is adjusted to a viscosity suitable for a coating method using, for example, the organic solvent, and on a substrate, a dip coating method, a flow coating method, a roll coating method, a bar coater method, a screen printing method. A tack-free coating film can be formed by applying the organic solvent contained in the composition at a temperature of about 60 to 100 ° C. by volatile drying (temporary drying).

  Examples of the base material include printed circuit boards and flexible printed circuit boards in which circuits are formed in advance, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, synthetic fiber. Copper graded laminates of all grades (FR-4 etc.) using other materials such as epoxy, fluorine, polyethylene, PPO, cyanate ester, etc., and other polyimide films, PET films Glass substrate, ceramic substrate, wafer plate and the like.

  The photocurable resin composition of the present invention can be applied and dried on a film (hereinafter also referred to as a carrier film) to form a dry film. When forming a dry film, the photocurable resin composition of the present invention is diluted with the above organic solvent to adjust to an appropriate viscosity, and is applied to a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll. A film can be obtained by applying a uniform thickness on a carrier film with a coater, gravure coater, spray coater or the like and drying at a temperature of 50 to 130 ° C. for 1 to 30 minutes. Although there is no restriction | limiting in particular about a coating film thickness, Generally, it is a film thickness after drying, 5-150 micrometers, Preferably it selects suitably in the range of 10-60 micrometers.

  As the carrier film, a plastic film is used, and a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, or a polystyrene film is preferably used. Although there is no restriction | limiting in particular about the thickness of a carrier film, Generally, it selects suitably in the range of 5-150 micrometers. Preferably, it is the range of 10-150 micrometers.

After the photo-curable resin composition of the present invention is formed on the carrier film, a cover film that can be peeled is laminated on the surface of the film for the purpose of preventing dust from adhering to the surface of the film. Is preferred.
As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper or the like can be used, and when the cover film is peeled off, the adhesive strength between the film and the carrier film is exceeded. What is necessary is just to have a smaller adhesive force between the membrane and the cover film.

  After laminating the dry film of the present invention on a substrate so as to come into contact with the substrate, a resin insulating layer can be formed by peeling off the carrier film.

  Volatile drying performed after the photocurable resin composition of the present invention is applied on a substrate or a carrier film may be performed by a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven, or the like (heat source of air heating system using steam) Can be carried out using a method in which hot air in a dryer is brought into countercurrent contact and a method in which a nozzle is blown onto a support).

  By performing exposure (irradiation of active energy rays) on the coating film or dry film obtained after applying the photocurable resin composition of the present invention and evaporating and drying the solvent, an exposed portion (by active energy rays). The irradiated part is cured. Further, by a contact method (or non-contact method), exposure is selectively performed with an active energy ray through a photomask having a pattern formed thereon or direct pattern exposure is performed by a laser direct exposure machine, and an unexposed portion is diluted with a dilute alkaline aqueous solution (for example, 0.3 The resist pattern is formed by development with a 3 wt% sodium carbonate aqueous solution. If necessary, a pattern may be formed by laser processing.

As an exposure machine used for the active energy ray irradiation, a high-pressure mercury lamp lamp, an ultra-high pressure mercury lamp lamp, a metal halide lamp, a mercury short arc lamp, and the like may be used as long as the apparatus irradiates ultraviolet rays in a range of 350 to 450 nm. Furthermore, a direct drawing apparatus (for example, a laser direct imaging apparatus that directly draws an image with a laser using CAD data from a computer) can also be used. As a laser light source of the direct drawing machine, either a gas laser or a solid laser may be used as long as laser light having a maximum wavelength in the range of 350 to 410 nm is used. The amount of exposure for image formation varies depending on the film thickness and the like, but is generally 20 to 800 mJ / cm ² , preferably 20 to 600 mJ / cm ² .

  The developing method can be a dipping method, a shower method, a spray method, a brush method or the like, and as a developer, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, Alkaline aqueous solutions such as ammonia and amines can be used.

  The method for producing a printed wiring board of the present invention includes a step of blending two or more fillers having different refractive indexes, one or more fillers in powder, and one or more fillers in a slurry state. It is characterized by. As described above, it is preferable that one or more fillers of the two or more fillers are blended in a slurry state with a refractive index smaller than 1.5 or larger than 1.7. Moreover, it is preferable that 1 or more types of fillers are 1.5-1.7 refractive index among 2 or more types of said fillers, and are mix | blended with powder.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following description, “parts” and “%” are based on mass unless otherwise specified.

(Synthesis Example 1: Synthesis of carboxyl group-containing resin (A-1))
In an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device, and a stirring device, 119.4 g of a novolac-type cresol resin (Showa Denko KK, Shounol CRG951, OH equivalent: 119.4), potassium hydroxide 1. 19 g and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually added dropwise and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1% and the hydroxyl value was 182.2 g / eq. A novolak-type cresol resin propylene oxide reaction solution was obtained. This was an average of 1.08 moles of alkylene oxide added per equivalent of phenolic hydroxyl group. 293.0 g of an alkylene oxide reaction solution of the obtained novolak-type cresol resin, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were mixed with a stirrer, a thermometer and an air blowing tube. The reaction vessel was charged with air at a rate of 10 ml / min and reacted at 110 ° C. for 12 hours while stirring. As the water produced by the reaction, 12.6 g of water was distilled as an azeotrope with toluene. Thereafter, the mixture was cooled to room temperature, and the resulting reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution and then washed with water. Thereafter, toluene was distilled off while substituting 118.1 g of diethylene glycol monoethyl ether acetate (carbitol acetate) with an evaporator to obtain a novolak acrylate resin solution. Next, 332.5 g of the obtained novolac acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown at a rate of 10 ml / min. While stirring, 60.8 g of tetrahydrophthalic anhydride was gradually added and reacted at 95 to 101 ° C. for 6 hours. A carboxyl group-containing resin having a solid acid value of 88 mgKOH / g and a solid content of 71% was obtained. This is designated as resin solution A-1.

(Synthesis Example 2: Synthesis of carboxyl group-containing resin (A-2))
Orthocresol novolac type epoxy resin (DIC Corporation, EPICLON N-695, softening point 95 ° C., epoxy equivalent 214, average number of functional groups 7.6) 1070 g, diethylene glycol monoethyl ether acetate (carbitol acetate) 600 g, acrylic acid 360 g, And 1.5 g of hydroquinone was added, and the mixture was heated and stirred at 100 ° C. to dissolve uniformly. Next, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. and reacted for 2 hours, then heated to 120 ° C. and reacted for further 12 hours. 415 g of aromatic hydrocarbon (Sorvesso 150) and 456.0 g of tetrahydrophthalic anhydride were added to the resulting reaction liquid, reacted at 110 ° C. for 4 hours, and after cooling, the solid content acid value 89 mgKOH / g, solid content 65 % Carboxyl group-containing resin was obtained. This is designated as resin solution A-2.

(Evaluation of refractive index)
The refractive indexes of the resins (solid content) of the resin solutions A-1 and A-2 obtained above were measured using a refractometer ER-7MW manufactured by ERMA under the conditions of 589.3 nm and 25 ° C. The results are shown in Table 1 below together with the refractive indexes of silica, alumina, barium sulfate and hydrotalcite.

(Preparation of silica slurry)
700 g of true spherical silica (SO-E2 manufactured by Admatech), 295 g of diethylene glycol monoethyl ether acetate (carbitol acetate) as a solvent, and 5 g of vinyl silane coupling agent as a silane coupling agent are mixed and stirred, and 0.5 μm zirconia in a bead mill. Dispersion treatment was performed using beads. This was repeated three times to produce a silica slurry filtered through a 3 μm filter.

(Preparation of alumina slurry)
700 g of alumina (ASFP-20 manufactured by Denka Co., Ltd.), 295 g of diethylene glycol monoethyl ether acetate (carbitol acetate) as a solvent, and 5 g of a wetting and dispersing agent were mixed and stirred, and dispersion treatment was performed in a bead mill in the same manner as described above. This was repeated three times to produce an alumina slurry filtered through a 3 μm filter.

(Preparation of barium sulfate slurry)
700 g of barium sulfate (B-30 manufactured by Sakai Chemical Industry Co., Ltd.), 295 g of diethylene glycol monoethyl ether acetate (carbitol acetate) as a solvent, and 5 g of a wetting and dispersing agent were mixed and stirred, and dispersion treatment was performed in a bead mill in the same manner as described above. This was repeated three times to produce a barium sulfate slurry filtered through a 3 μm filter.

(Preparation of hydrotalcite slurry)
Hydrotalcite (DHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd.) 700 g, diethylene glycol monoethyl ether acetate (carbitol acetate) 295 g as a solvent, and 5 g of a wetting and dispersing agent were mixed and stirred, and dispersion treatment was performed in a bead mill in the same manner as described above. . This was repeated three times to prepare a hydrotalcite slurry filtered through a 3 μm filter.

<Examples 1-5 and Comparative Examples 1-4>
Using the above resin solution and slurry, blended in the blending (parts by mass) shown in Table 2, premixed with a stirrer, kneaded with a three roll mill, Examples 1-5, Comparative Examples 1-4 A photocurable resin composition was prepared.
In addition, when the dispersion degree of the obtained photocurable resin composition was evaluated by the particle size measurement by the grindometer made from Eriksen, it was each 15 micrometers or less.

The meanings of the numbers in Table 2 are as follows.
* 1: SO-E2 manufactured by Admatech
* 2: Denka's ASFP-20
* 3: Sakai Chemical Industry B-30
* 4: DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd.
* 5: Dipentaerystol hexaacrylate * 6: Phenol novolac epoxy resin * 7: Triglycidyl isocyanurate * 8: Melamine * 9: 2,4,6-trimethylbenzoyldiphenylphosphine oxide * 10: Pigment Blue 15: 3
* 11: Pigment Yellow 147
* 12: Silicone antifoaming agent * 13: Dipropylene glycol monomethyl ether

(Particle size distribution)
About the photocurable resin composition of the said Example 3 and the comparative example 2, the particle size distribution was measured in the micro track | truck (Nikkiso Co., Ltd. MT3300EX). The result of Example 3 is shown in FIG. 1, and the result of Comparative Example 2 is shown in FIG. _{D 50} Example 3 0.41 _{.mu.m, D 90} was 1.7 [mu] m. _{D 50} of Comparative Example 2 is 3.7 _{.mu.m, D 90} was 8.1Myuemu.

Characterization:
The photo-curable resin compositions of the above Examples and Comparative Examples were applied on the entire surface of the patterned copper foil substrate by screen printing, dried for 30 minutes in a hot air circulating drying oven at 80 ° C., and then released to room temperature. It cooled and obtained the evaluation board | substrate. The characteristics of the obtained evaluation substrate were evaluated as follows.
In addition, in the following evaluation, formation of the pattern of the photocurable resin composition is optimal for the obtained evaluation substrate using a high-pressure mercury lamp mounting exposure apparatus (mercury short arc lamp mounting exposure equipment manufactured by Oak Manufacturing Co., Ltd.). It exposed by the exposure amount, and performed by developing for 60 second on the conditions of temperature: 30 degreeC, spray pressure: 0.2MPa, developing solution: 1 mass% sodium carbonate aqueous solution. The optimum exposure amount was exposed through a step tablet (T4105C manufactured by Stouffer, Inc.) at the time of exposure, and the optimum exposure amount was obtained when the number of step tablet steps remaining after development was eight. After pattern formation, UV irradiation was performed in a UV conveyor furnace under the condition of an integrated exposure amount of 1000 mJ / cm ² , and then heated at 160 ° C. for 60 minutes to cure the patterned photocurable resin composition.

(Resolution)
Using the negative pattern having a via opening diameter of 60 μm as a resolution evaluation negative mask, an opening pattern of the photocurable resin composition was formed on the obtained evaluation substrate and cured. The diameter at the bottom of the opening was observed and measured with a scanning electron microscope having a magnification of 1000 times, and evaluated under the following evaluation conditions.
◎: Diameter greater than 55 μm and less than 60 μm ○: Diameter greater than 50 μm and less than 55 μm ×: Diameter less than 50 μm

(Crack resistance)
A pattern of a photocurable resin composition was formed and cured under the above conditions using a negative pattern having a square blank as a negative mask for resolution evaluation on the obtained evaluation substrate. Thereafter, a thermal history was added with -55 ° C for 30 minutes and 125 ° C for 30 minutes as one cycle, and after 1000 cycles, observation was performed with an optical microscope, and evaluation was performed under the following evaluation conditions.
◎: No cracks occurred ○: Cracks occurred ×: Significant cracks occurred

(HAST resistance)
Under the same conditions as described above except that the photocurable resin composition is applied to a BT substrate on which comb-shaped electrodes (line / space = 50 microns / 50 microns) are formed instead of the patterned copper foil substrate. An evaluation board was obtained. The photocurable resin composition on the obtained evaluation substrate was cured under the same conditions as above to form a cured coating film. The substrate thus obtained was placed in a high-temperature and high-humidity tank under an atmosphere of 130 ° C. and a humidity of 85%, charged with a voltage of 12 V, and subjected to an in-chamber HAST test for 168 hours. The insulation resistance value in the tank when 168 hours passed was evaluated according to the following criteria.
◎: 10 ⁸ Ω or more ○: 10 ⁶ Ω more than 10 ⁸ Ω less than ×: 10 ⁶ Ω or less

(Haze value)
About Examples 1-5 and Comparative Examples 1-4, what mixed and disperse | distributed only the carboxyl group-containing resin and filler component of Table 2 was apply | coated with the applicator on the glass substrate, and hot-air circulation type drying of 80 degreeC was carried out. The film was dried in an oven for 30 minutes to obtain a dried coating film having a thickness of 25 μm. The haze value of the dried coating film was measured with an ultraviolet-visible spectrophotometer (V-600 manufactured by JASCO Corporation). Haze value = diffuse transmittance / total light transmittance × 100 (%). The larger the value, the more diffused the light. If the haze value is small, the light is difficult to diffuse, and the resolution is excellent.

* 1: In Comparative Example 3, since the amount of the solvent was too large, the film formability was insufficient and evaluation was impossible.

  As is clear from the results shown in Table 3 above, the photocurable resin composition of the present invention obtains a cured product with good resolution despite containing multiple types of fillers having different refractive indexes. It was possible. On the other hand, the photocurable resin composition shown in the comparative example was inferior in resolution and poor in performance as a photocurable resin composition, such as lacking in film formability.

That is, the photocurable resin composition of the present invention is a photocurable resin composition comprising a carboxyl group-containing resin, a photopolymerization initiator, and two or more kinds of fillers having different refractive indexes. among the above fillers, one or more fillers are blended in a powder, one or more fillers, powder Ri Na are blended in a slurry state dispersed in advance in the liquid, the photocurable resin composition particle size distribution _{D 50} is at 3.0μm or _less, in _{which D 90} of characterized der Rukoto following 8.0μm in.

In the method for producing a photocurable resin composition of the present invention, two or more kinds of fillers having different refractive indexes are used, one or more kinds of fillers are powdered, and one or more kinds of fillers are powdered into a liquid in advance. in a slurry state dispersed, it saw including a step of compounding, and the particle size distribution D ₅₀ of 3.0μm or less in the photocurable resin composition, in which D ₉₀ of which equal to or less than 8.0μm is there.

That is, the photocurable resin composition of the present invention is a photocurable resin composition comprising a carboxyl group-containing resin, a photopolymerization initiator, and two or more kinds of fillers having different refractive indexes. Among the above fillers, one or more fillers are blended in powder (except when only hydrotalcite is blended in powder) , and one or more fillers disperse the powder in liquid in advance The refractive index of the filler mixed in the slurry state is 1.5 to 1.7, and the refractive index of the filler mixed in the slurry state is smaller than 1.5. Or larger than 1.7, wherein the particle size distribution D ₅₀ in the photocurable resin composition is 3.0 μm or less, and D ₉₀ is 8.0 μm or less. It is.

The method for producing the photocurable resin composition of the present invention comprises two or more fillers having different refractive indexes, one or more fillers in powder form (provided that only hydrotalcite is blended in powder form). And a step of blending one or more fillers in a slurry state in which powder is dispersed in a liquid in advance, and the refractive index of the filler blended with the powder is 1.5 to 1. 7, wherein either the refractive index of the filler made are blended in a slurry state is less than 1.5, or, there is greater than 1.7, the particle size distribution D ₅₀ in the photocurable resin composition 3 and a .0μm _less, is characterized in that the _{D 90} of at most 8.0 .mu.m.

FIG. 1 is a chart showing the results of measuring the particle size distribution of the photocurable resin composition of Reference Example 3 with a laser diffraction / scattering particle size distribution analyzer. FIG. 2 is a chart showing the results of measuring the particle size distribution of a photocurable resin composition (Comparative Example 2) containing only a powder filler using a laser diffraction / scattering particle size distribution measuring apparatus.

<Examples 1 , 2 and 5 , Reference Examples 3, 4 and Comparative Examples 1-4>
Using the above resin solution and slurry, blended in the blending (parts by mass) shown in Table 2, premixed with a stirrer, kneaded with a three roll mill, Examples 1 , 2, and 5 , Reference Example 3, 4 and the photocurable resin compositions of Comparative Examples 1 to 4 were prepared.
In addition, when the dispersion degree of the obtained photocurable resin composition was evaluated by the particle size measurement by the grindometer made from Eriksen, it was each 15 micrometers or less.

The meanings of the numbers in Table 2 are as follows.
* 1: SO-E2 manufactured by Admatech
* 2: Denka's ASFP-20
* 3: Sakai Chemical Industry B-30
* 4: DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd.
* 5: Dipentaerystol hexaacrylate * 6: Phenol novolac epoxy resin * 7: Triglycidyl isocyanurate * 8: Melamine * 9: 2,4,6-trimethylbenzoyldiphenylphosphine oxide * 10: Pigment Blue 15: 3
* 11: Pigment Yellow 147
* 12: Silicone antifoaming agent * 13: Dipropylene glycol monomethyl ether

(Particle size distribution)
About the photocurable resin composition of the said reference example 3 and the comparative example 2, the particle size distribution was measured in the micro track | truck (Nikkiso MT3300EX). The result of Reference Example 3 is shown in FIG. 1, and the result of Comparative Example 2 is shown in FIG. The _{D 50} of Reference Example 3 0.41 _{.mu.m, D 90} was 1.7 [mu] m. _{D 50} of Comparative Example 2 is 3.7 _{.mu.m, D 90} was 8.1Myuemu.

Characterization:
After coating the entire surface of the photocurable resin compositions of the above Examples , Reference Examples and Comparative Examples on a patterned copper foil substrate by screen printing and drying in a hot air circulating drying oven at 80 ° C. for 30 minutes, After cooling to room temperature, an evaluation substrate was obtained. The characteristics of the obtained evaluation substrate were evaluated as follows.
In addition, in the following evaluation, formation of the pattern of the photocurable resin composition is optimal for the obtained evaluation substrate using a high-pressure mercury lamp mounting exposure apparatus (mercury short arc lamp mounting exposure equipment manufactured by Oak Manufacturing Co., Ltd.). It exposed by the exposure amount, and performed by developing for 60 second on the conditions of temperature: 30 degreeC, spray pressure: 0.2MPa, developing solution: 1 mass% sodium carbonate aqueous solution. The optimum exposure amount was exposed through a step tablet (T4105C manufactured by Stouffer, Inc.) at the time of exposure, and the optimum exposure amount was obtained when the number of step tablet steps remaining after development was eight. After pattern formation, UV irradiation was performed in a UV conveyor furnace under the condition of an integrated exposure amount of 1000 mJ / cm ² , and then heated at 160 ° C. for 60 minutes to cure the patterned photocurable resin composition.

(Haze value)
For Examples 1 , 2 and 5, Reference Examples 3 and 4, and Comparative Examples 1 to 4, only the carboxyl group-containing resin and filler component in Table 2 were mixed and dispersed on a glass substrate with an applicator. And dried for 30 minutes in a hot air circulation drying oven at 80 ° C. to obtain a dry coating film having a thickness of 25 μm. The haze value of the dried coating film was measured with an ultraviolet-visible spectrophotometer (V-600 manufactured by JASCO Corporation). Haze value = diffuse transmittance / total light transmittance × 100 (%). The larger the value, the more diffused the light. If the haze value is small, the light is difficult to diffuse, and the resolution is excellent.

* 1: In Comparative Example 3, since the amount of the solvent was too large, the film formability was insufficient and evaluation was impossible.

Claims (9)

A photocurable resin composition comprising a carboxyl group-containing resin, a photopolymerization initiator, and two or more fillers having different refractive indexes,
Of the two or more kinds of fillers, one or more kinds of fillers are blended in a powder form, and one or more kinds of fillers are blended in a slurry state. Particle size distribution D ₅₀ is at 3.0μm or less, the photocurable resin composition of claim 1 wherein the D ₉₀ of which being not more than 8.0μm in the photocurable resin composition.   Of the two or more fillers, one or more fillers have a refractive index smaller than 1.5 or larger than 1.7 and are blended in a slurry state. The photocurable resin composition of Claim 1 or 2.   The one or more fillers of the two or more kinds of fillers have a refractive index of 1.5 to 1.7 and are blended in powder form. The photocurable resin composition according to claim 1.   The photocurable resin composition according to any one of claims 1 to 4, wherein the carboxyl group-containing resin has an aromatic ring.   The photocurable resin composition according to any one of claims 1 to 5, wherein the carboxyl group-containing resin contains a carboxyl group-containing resin obtained using a phenol compound as a starting material.   A dry film obtained by applying and drying the photocurable resin composition according to any one of claims 1 to 6 on a film.   It is obtained by applying and drying the photocurable resin composition according to any one of claims 1 to 6 or the photocurable resin composition according to any one of claims 1 to 6 on a film. A printed wiring board comprising a cured product obtained by curing a dry film by at least one of irradiation with active energy rays and heating.   A photocurable resin composition comprising a step of blending two or more kinds of fillers having different refractive indices, one or more kinds of fillers in powder and one or more kinds of fillers in a slurry state. Production method.