JP2018163336A - Black photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a black photosensitive resin composition that makes it possible to obtain a cured product having excellent resolution and hiding power without impairing basic characteristics such as sensitivity and insulation reliability.SOLUTION: A black photosensitive resin composition contains (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, and (E) a carbon black dispersion.SELECTED DRAWING: None

Description

  The present invention relates to a black photosensitive resin composition having excellent resolution and hiding power, and when used as an insulating coating, for example, a solder resist of a printed wiring board, fine pitch and finer electrodes. It is related with the black photosensitive resin composition which can respond to this.

  A printed wiring board is used to form a pattern of a conductor circuit on a substrate and to mount electronic components on the soldering land of the pattern by soldering. The circuit portion excluding the soldering land is made of an insulating film ( For example, it is coated with a solder resist film). This prevents solder from adhering to unnecessary parts when soldering electronic components to a printed wiring board, and prevents circuit conductors from being directly exposed to air and being corroded by oxidation or humidity. To do.

  In recent years, in the electronics field, demands for smaller size and lighter weight have further increased, and accordingly, in order to arrange more compact electronic components with high density, the fine pitch of the conductor circuit pattern of the printed wiring board is required. There are demands for miniaturization, miniaturization, and high accuracy. Accordingly, the solder resist film is also required to have higher performance in terms of various properties such as resolution and hiding power, and one of such solder resist films is black.

  As a material for forming a black solder resist film, a solder resist composition in which a colorant blended in a carboxyl group-containing resin is a black colorant and one or more colorants other than the black colorant has been proposed. (Patent Document 1). Carbon black is used as a black colorant. However, since the black solder resist composition of Patent Document 1 is black, it is difficult for light to uniformly reach the deep part of the solder resist coating film, photocuring in the deep part of the solder resist coating film is not sufficient, and resolution is sufficient. There was a problem that was not.

  On the other hand, if the blending amount of the black colorant is limited in order to obtain resolution, there is a problem that the hiding power of the coating film is not sufficient.

JP 2008-257045 A

  In view of the above circumstances, an object of the present invention is to provide a black photosensitive resin composition capable of obtaining a cured product having excellent resolution and hiding power without impairing basic characteristics such as sensitivity and insulation reliability. There is to do.

  Aspects of the present invention include (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, and (E) a carbon black dispersion. The black photosensitive resin composition characterized by containing.

  In the said aspect, the carbon black dispersion is mix | blended as a black coloring agent. The carbon black dispersion is obtained by dispersing carbon black in a liquid phase dispersion medium. Therefore, in the said aspect, carbon black powder is not mix | blended directly in the resin composition.

  In the embodiment of the present invention, the carbon black contained in the carbon black dispersion (E) has a cumulative volume percentage of 50% by volume particle diameter (D50) of 0.50 μm or less and a cumulative volume percentage of 95% by volume. (D95) is a black photosensitive resin composition characterized by being 1.0 μm or less.

  In the aspect of the present invention, the carbon black contained in the carbon black dispersion (E) has a cumulative volume percentage of 50 volume%, a particle diameter (D50) of 0.20 to 0.30 μm, and a cumulative volume percentage of 95 volume%. The black photosensitive resin composition is characterized by having a particle diameter (D95) of 0.40 to 0.60 μm.

  An aspect of the present invention is the black photosensitive resin composition, wherein the (E) carbon black dispersion contains carbon black, a resin, and an organic solvent.

  An aspect of the present invention is the black photosensitive resin composition, wherein the carbon black dispersion (E) contains 5.0 to 50% by mass of carbon black.

  An aspect of the present invention is the black photosensitive resin composition, wherein the carbon black contained in the carbon black dispersion (E) contains furnace black.

  An aspect of the present invention is a black photosensitive resin composition, wherein the furnace black has an average primary particle size of 20 to 80 nm and a pH of 2.0 to 8.0.

  According to the aspect of the present invention, basic characteristics such as sensitivity and insulation reliability are obtained by blending a carbon black dispersion in which powdered carbon black is dispersed in a liquid phase dispersion medium instead of powdered carbon black. The hardened | cured material which has the outstanding resolution and hiding power can be obtained, without impairing.

  According to the aspect of the present invention, the carbon black contained in the carbon black dispersion has a D50 of 0.20 to 0.30 μm and a D95 of 0.40 to 0.60 μm. The balance can be improved and the blending amount of carbon black can be reduced.

  Next, each component of the black photosensitive resin composition of this invention is demonstrated. The black photosensitive resin composition of the present invention comprises (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, and (E). And a carbon black dispersion.

(A) Carboxyl group-containing photosensitive resin The carboxyl group-containing photosensitive resin is not particularly limited, and examples thereof include a resin having one or more photosensitive unsaturated double bonds. As a carboxyl group-containing photosensitive resin, for example, at least part of the epoxy group of a polyfunctional epoxy resin having two or more epoxy groups in one molecule, acrylic acid or methacrylic acid (hereinafter referred to as “(meth) acrylic acid”) A radical polymerizable unsaturated monocarboxylic acid such as epoxy (meth) acrylate to obtain a radical polymerizable unsaturated monocarboxylic oxide epoxy resin, and a polybasic acid or its Mention may be made of polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxide epoxy resins such as polybasic acid-modified epoxy (meth) acrylates obtained by reacting anhydrides.

  Any polyfunctional epoxy resin can be used as long as it is a bifunctional or higher functional epoxy resin. The epoxy equivalent of the polyfunctional epoxy resin is not particularly limited, but the upper limit is preferably 2000 g / eq, more preferably 1000 g / eq, and particularly preferably 500 g / eq. On the other hand, the lower limit is preferably 100 g / eq, particularly preferably 200 g / eq.

  Examples of polyfunctional epoxy resins include biphenyl aralkyl type epoxy resins, phenyl aralkyl type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, silicone modified epoxy resins, and the like. Rubber modified epoxy resin, ε-caprolactone modified epoxy resin, bisphenol A type, bisphenol F type, bisphenol AD type and other phenol novolac type epoxy resins, о-cresol novolac type cresol novolac type epoxy resins, bisphenol A novolak type epoxy Resin, cycloaliphatic polyfunctional epoxy resin, glycidyl ester polyfunctional epoxy resin, glycidylamine polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol For example, a denatured novolac type epoxy resin, a polyfunctional modified novolak type epoxy resin, a condensate type epoxy resin of a phenol and an aromatic aldehyde having a phenolic hydroxyl group can be used. Moreover, you may use what introduce | transduced halogen atoms, such as Br and Cl, into these resin. These epoxy resins may be used alone or in combination of two or more. Of these, biphenyl aralkyl type epoxy resins and bisphenol A type epoxy resins are preferred from the viewpoint of improving sensitivity, insulation reliability, and resolution in a well-balanced manner, and biphenyl aralkyl type epoxy resins are preferred from the point of further improving insulation reliability. Is particularly preferred.

  The radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, and acrylic acid and methacrylic acid are preferable. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more.

  The reaction method of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid is not particularly limited. For example, the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid are reacted by heating in an appropriate diluent. Can do.

  The polybasic acid or polybasic acid anhydride is for reacting with a hydroxyl group produced by the reaction between the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid to introduce a free carboxyl group into the resin. The polybasic acid or its anhydride is not particularly limited, and either saturated or unsaturated can be used. Polybasic acids include, for example, succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4- Ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydro Examples include phthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid, and diglycolic acid. Examples of polybasic acid anhydrides include these anhydrides. These compounds may be used alone or in combination of two or more.

  In the present invention, the above-mentioned polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin can also be used as a carboxyl group-containing photosensitive resin, but if necessary, the carboxyl group of the above-mentioned polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin. In addition, a carboxyl group-containing photosensitive resin further improved in photosensitivity by further introducing a radical polymerizable unsaturated group by reacting a glycidyl compound having one or more radical polymerizable unsaturated groups and an epoxy group It is good.

  In this carboxyl group-containing photosensitive resin with improved photosensitivity, the radical polymerizable unsaturated group is bonded to the side chain of the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin skeleton by the reaction of the glycidyl compound. The photopolymerization reactivity is high, and the photosensitivity can be further improved. Examples of the compound having one or more radically polymerizable unsaturated groups and an epoxy group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, pentaerythritol trimethacrylate monoglycidyl ether, and the like. Can be mentioned. In addition, you may have multiple glycidyl groups in 1 molecule. The above-mentioned compound having one or more radically polymerizable unsaturated groups and an epoxy group may be used alone or in combination of two or more.

  Further, as the carboxyl group-containing photosensitive resin, an acid-modified urethanized unsaturated monocarboxylic oxide epoxy resin such as an acid-modified urethanized epoxy (meth) acrylate resin may be used. The acid-modified urethanized unsaturated monocarboxylic oxide epoxy resin is obtained by first obtaining a radical polymerizable unsaturated monocarboxylic oxide epoxy resin such as epoxy (meth) acrylate as described above, and the above-mentioned polybasic acid on the generated hydroxyl group. Alternatively, it can be obtained by reacting an anhydride thereof with a compound having two or more isocyanate groups in one molecule.

  The compound having two or more isocyanate groups in one molecule is not particularly limited. For example, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), methylene biscyclohexyl isocyanate, Examples thereof include diisocyanates such as trimethylhexamethyl diisocyanate, hexane diisocyanate, hexamethylamine diisocyanate, methylenebiscyclohexyl isocyanate, toluene diisocyanate, 1,2-diphenylethane diisocyanate, 1,3-diphenylpropane diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethyl diisocyanate. These compounds may be used alone or in combination of two or more.

  In the present invention, an acid-modified urethanized unsaturated monocarboxylic oxide epoxy resin such as the above-mentioned acid-modified urethanized epoxy (meth) acrylate resin can also be used as a carboxyl group-containing photosensitive resin. Further introduction of radically polymerizable unsaturated groups by reacting the glycidyl compound having one or more radically polymerizable unsaturated groups and epoxy groups with the carboxyl group of the modified urethanized unsaturated monocarboxylic oxide epoxy resin. In addition, a carboxyl group-containing photosensitive resin with improved photosensitivity may be used.

  The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit is preferably 30 mgKOH / g, particularly preferably 40 mgKOH / g, from the viewpoint of reliable alkali development. On the other hand, the upper limit of the acid value is preferably 200 mgKOH / g from the viewpoint of preventing dissolution of the exposed area with an alkali developer, and particularly preferably 150 mgKOH / g from the viewpoint of preventing moisture resistance of the cured product and preventing deterioration of electrical characteristics.

  Further, the mass average molecular weight of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit is preferably 3000 and particularly preferably 5000 from the viewpoint of toughness of the cured product and dryness to touch. On the other hand, the upper limit value of the mass average molecular weight is preferably 200000, particularly preferably 50000, from the viewpoint of smooth alkali developability.

  The carboxyl group-containing photosensitive resin may be synthesized in the reaction step using the above raw materials, or a commercially available carboxyl group-containing photosensitive resin may be used. Examples of commercially available carboxyl group-containing photosensitive resins include “SP-4621” (Showa Denko KK), “ZAR-2000”, “ZFR-1122”, “FLX-2089”, “ZCR-1569H”. (Nippon Kayaku Co., Ltd.), “Cyclomer P (ACA) Z-250” (Daicel Ornex Co., Ltd.), and the like. These resins may be used alone or in combination of two or more.

(B) Photopolymerization initiator The photopolymerization initiator is not particularly limited as long as it is generally used, and any of them can be used. Specifically, for example, 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone 1- [9-ethyl-6- (2-methylbenzoyl)- 9H-carbazol-3-yl] -1- (0-acetyloxime), (Z)-(9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1-methoxypropane-2 -Yl) oxy) -2-methylphenyl) methanone O-acetyloxime, 2- (acetyloxyiminomethyl) thioxanthen-9-one, 1,8-octanedione, 1,8-bis [9-ethyl-6 -Nitro-9H-carbazol-3-yl]-, 1,8-bis (O-acetyloxime), 1,8-octanedione, 1,8-bis [9- (2-ethylhexyl) -6-nitro- 9H-carbazo Ru-3-yl]-, 1,8-bis (O-acetyloxime), (Z)-(9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1-methoxypropane -2-yl) oxy) -2-methylphenyl) methanone Oxime ester compounds such as O-acetyloxime, phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, benzoin, benzoin methyl ether, benzoin ethyl ether , Benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-methyl-4'- (Methylthio) -2-morpholinopropio Enone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p -Phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2- Examples include chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, and P-dimethylaminobenzoic acid ethyl ester. It is. These may be used alone or in combination of two or more.

  Content of a photoinitiator is not specifically limited, 0.1 mass part-10 mass parts are preferable with respect to 100 mass parts of carboxyl group-containing photosensitive resin, Especially 0.2 mass part-5 mass parts are especially. preferable.

(C) Reactive Diluent The reactive diluent is, for example, a photopolymerizable monomer and is a compound having at least one polymerizable double bond per molecule, preferably at least two polymerizable double bonds per molecule. The reactive diluent is used to sufficiently cure the black photosensitive resin composition to obtain a cured product having acid resistance, heat resistance, alkali resistance, and the like.

  The reactive diluent is not particularly limited as long as it is the above compound. For example, 2-hydroxyethyl methacrylate, phenoxyethyl methacrylate, diethylene glycol monomethacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 1,4- Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neo Pentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate Rate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tri (Meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, urethane (meth) acrylate Etc. The. These may be used alone or in combination of two or more.

  Content of a reactive diluent is not specifically limited, For example, 2.0-100 mass parts is preferable with respect to 100 mass parts of carboxyl group-containing photosensitive resin, and 10-50 mass parts is especially preferable.

(D) Epoxy compound An epoxy compound is for obtaining the hardened | cured material of sufficient intensity | strength by raising the crosslinking density of hardened | cured material, For example, an epoxy resin can be mentioned. Examples of the epoxy resin include biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, bisphenol A type epoxy resin, novolak type epoxy resin (phenol novolak type epoxy resin, o-cresol novolak type epoxy resin, p-tert-butylphenol novolak type). Bisphenol F type and bisphenol S type epoxy resin obtained by reacting bisphenol F and bisphenol S with epichlorohydrin, and cycloaliphatic epoxy resin having cyclohexene oxide group, tricyclodecane oxide group, cyclopentene oxide group, etc. Triglycidides having a triazine ring such as tris (2,3-epoxypropyl) isocyanurate, triglycidyltris (2-hydroxyethyl) isocyanurate Isocyanurate, dicyclopentadiene type epoxy resins, adamantane type epoxy resin. These compounds may be used alone or in combination of two or more. Of these, biphenyl aralkyl type epoxy resins and bisphenol A type epoxy resins are preferred from the viewpoint of improving sensitivity, insulation reliability, and resolution in a well-balanced manner, and biphenyl aralkyl type epoxy resins are preferred from the viewpoint of further improving resolution. Is particularly preferred. In addition, when using a polybasic acid-modified radical polymerizable unsaturated monocarboxylic oxide epoxy resin as the carboxyl group-containing photosensitive resin, the epoxy compound used as the basic skeleton of the carboxyl group-containing photosensitive resin is used as the epoxy compound. It is preferable to use it.

  The content of the epoxy compound is not particularly limited, and is preferably, for example, 10 to 200 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin, from the viewpoint of obtaining a coating film having sufficient strength after curing. 100 parts by mass is particularly preferred.

(E) Carbon black dispersion The carbon black dispersion is a dispersion of carbon black in a liquid phase dispersion medium. Specific examples include a mixture of an organic solvent, a resin, and carbon black powder.

  Examples of the organic solvent include, but are not limited to, esters such as ethyl diglycol acetate, methoxypropyl acetate, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, ethanol, propanol, ethylene glycol, propylene glycol, etc. Alcohols such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol monomethyl Ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether Ether, may be mentioned glycol ethers such as triethylene glycol monoethyl ether.

  Examples of the resin include a urethane resin, an epoxy resin, an acrylic resin, and a phenol resin.

  The particle size distribution of the carbon black is not particularly limited. For example, the upper limit value of the particle diameter (D50) having a cumulative volume percentage of 50% by volume is preferably 0.50 μm from the viewpoint of reliably obtaining resolution and hiding power. 0.30 μm is more preferable from the viewpoint of improving the resolution and hiding power in a balanced manner, and 0.25 μm is particularly preferable from the viewpoint of improving the resolution and the hiding power in a balanced manner while reducing the blending amount. On the other hand, the lower limit of D50 is preferably 0.10 μm from the viewpoint of good dispersibility in the carbon black dispersion, more preferably 0.15 μm, and particularly preferably 0.20 μm from the viewpoint of further improving the resolution. .

  The upper limit of the particle diameter (D95) with a cumulative volume percentage of 95% by volume is preferably 1.0 μm from the viewpoint of reliably obtaining resolution and hiding power, and is 0 from the viewpoint of improving the resolution and hiding power in a balanced manner. 80 μm is more preferable, and 0.60 μm is particularly preferable from the viewpoint of improving the resolution and hiding power in a balanced manner while reducing the blending amount. On the other hand, the lower limit of D95 is preferably 0.30 μm, more preferably 0.40 μm, and particularly preferably 0.45 μm from the viewpoint of good dispersibility in the carbon black dispersion.

  The particle size distribution of carbon black is such that D50 is 0.20 to 0.30 μm and D95 is 0.40 to 0.60 μm from the viewpoint of further improving the resolution and hiding power while reducing the blending amount. preferable. As a means for adjusting the particle size distribution of carbon black, for example, when preparing a carbon black dispersion, as a mixing and dispersing means, a pulverizer for fine powder production (for example, a bead mill, a pearl mill, a ball mill, a jet mill, a sand mill, And a mill dispersion method using an attritor or the like. By adjusting the operating speed (pulverization energy), raw material supply speed, bead diameter, etc. of the pulverizer for producing fine powder, the degree of pulverization, ie, the particle size distribution can be adjusted.

  The ratio of the carbon black contained in the carbon black dispersion is not particularly limited. For example, the upper limit is preferably 50% by mass, and 20% by mass from the viewpoint of the dispersibility of the carbon black dispersion in the resin composition. Particularly preferred. On the other hand, the lower limit is preferably 5.0% by mass, particularly preferably 10% by mass, from the viewpoint of reliably obtaining resolution and hiding power.

  Further, the content of carbon black is not particularly limited. For example, the upper limit is 20 masses from the viewpoint of flexibility of the cured product and excellent insulation reliability with respect to 100 mass parts of the carboxyl group-containing photosensitive resin. Part is preferable, and 10 parts by mass is particularly preferable. On the other hand, the lower limit is preferably 0.5 parts by mass and particularly preferably 1.0 part by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin from the viewpoint of reliably improving the hiding power.

  Further, furnace black produced by the furnace method may be used as the carbon black contained in the carbon black dispersion from the viewpoint of surely improving the hiding power. The average primary particle diameter of the furnace black is not particularly limited, but the lower limit is preferably 20 nm from the viewpoint of preventing reaggregation, and particularly preferably 35 nm from the viewpoint of further improving the hiding power. Further, the upper limit is preferably 80 nm from the viewpoint of dispersing the resin composition at a high concentration, and particularly preferably 75 nm from the viewpoint of further improving the hiding power. The pH of the furnace black is not particularly limited, but the lower limit is preferably 2.0 from the viewpoint of chemical resistance, and the upper limit is preferably 8.0 from the viewpoint of preventing color unevenness.

  In the black photosensitive resin composition of the present invention, in addition to the components (A) to (E), various components such as extender pigments, flame retardants, curing accelerators, antifoaming agents, A non-reactive diluent or the like can be blended.

  The extender pigment contributes to increasing the physical strength of the coating film of the black photosensitive resin composition, and examples thereof include talc, barium sulfate, silica, alumina, aluminum hydroxide, and mica.

  A flame retardant is not specifically limited, A well-known thing can be used. Examples of the flame retardant include a phosphorus element-containing compound. Specific examples of the phosphorus element-containing compound include tris (chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-bromopropyl) phosphate, tris (bromo). Halogenated phosphoric acid such as chloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromoneopentyl) phosphate Esters; non-halogen aliphatic phosphate esters such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate; triphenyl phosphate Cresyl diphenyl phosphate, dicresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, xylenyl diphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyl diphenyl phosphate, diisopropylphenylphenyl phosphate, tris (trimethylphenyl) phosphate, Tris (t-butylphenyl) phosphate, hydroxyphenyl diphenyl phosphate, octyl diphenyl phosphate, 3-glycidyloxypropylene diphenylphosphine oxide, 3-glycidyloxydiphenylphosphine oxide, diphenylvinylphosphine oxide, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphafe Non-halogens such as entolen-10-oxide, 2- (9,10-dihydro-9-oxa-10-oxide-10-phosphaphenanthrene-10-yl) methylsuccinic acid bis- (2-hydroxyethyl) -ester polymer Aromatic phosphoric acid ester; aluminum trisdiethylphosphinate, aluminum diethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, Bisdiethylphosphinate titanyl, tetrakisdiethylphosphinate titanium, bismethylethylphosphinate titanyl, tetrakismethylethylphosphinate titanium, bisdiphenylphosphinate tita Cyclic, chain phosphazene systems having substituted or unsubstituted phenoxy groups or substituted or unsubstituted naphthoxy groups, such as metal salts of phosphinic acids such as titanium, tetrakisdiphenylphosphinate, cyclic phenoxyphosphazenes, and cyclic cyanophenoxyphosphazenes A compound, triallylphosphine, and the like.

  Examples of the curing accelerator include dicyandiamide (DICY) and derivatives thereof, organic acid hydrazide, diaminomaleonitrile (DAMN) and derivatives thereof, guanamine and derivatives thereof, melamine and derivatives thereof, and amine imide (AI). In addition, examples of the antifoaming agent include silicone-based, hydrocarbon-based, and acrylic-based agents.

  A non-reactive diluent is for adjusting the drying property and coating viscosity of a black photosensitive resin composition, for example, an organic solvent can be mentioned. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether , Glycol ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene Glycol monomethyl ether acetate and the above Esters such as esters of calls ethers; ethanol, can be mentioned propanol, ethylene glycol, and alcohols such as propylene glycol.

  Although the manufacturing method of the above-mentioned black photosensitive resin composition is not limited to a specific method, For example, after mix | blending each said component by a predetermined ratio, it can mix and disperse | distribute with a three roll at room temperature. Moreover, you may pre-mix with a stirrer before the said mixing dispersion | distribution as needed.

  Next, the usage example of the black photosensitive resin composition of this invention is demonstrated. Here, a method of applying the black photosensitive resin composition of the present invention as an insulating protective film (for example, a solder resist film) of a printed wiring board will be described as an example.

  The black photosensitive resin composition of the present invention obtained as described above is subjected to, for example, a screen printing method, a bar coater method, a blade on a printed wiring board which is a substrate having a circuit pattern formed by etching a copper foil. A coating film is formed by coating at a desired thickness by a known method such as a coater method, a knife coater method, a roll coater method, a gravure coater method, or a spray coater method. Next, when a non-reactive diluent such as an organic solvent is contained in the black photosensitive resin composition, in order to volatilize the non-reactive diluent, the temperature is about 60 to 80 ° C. Pre-drying is performed by heating for about minutes to form a tack-free coating film.

  Next, a negative film (photomask) having a light-transmitting pattern other than the circuit pattern land is brought into close contact with the pre-dried coating film, and ultraviolet light (for example, in a wavelength range of 300 to 400 nm) is formed thereon. ). Then, the coating film is developed by removing the non-exposed areas corresponding to the lands with a dilute alkaline aqueous solution. As the developing method, a spray method, a shower method, or the like is used, and examples of the diluted alkaline aqueous solution to be used include 0.5 to 5% by mass of an aqueous sodium carbonate solution. Next, by performing post-cure for 20 to 80 minutes with a hot air circulation dryer or the like at 130 to 170 ° C., a desired insulating protective film such as a solder resist film can be formed on the printed wiring board.

  Next, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Examples 1-8, Comparative Examples 1-3
The black photosensitive materials used in Examples 1 to 8 and Comparative Examples 1 to 3 were prepared by mixing the components shown in Table 1 below in the proportions shown in Table 1 and mixing and dispersing them at room temperature using three rolls. A functional resin composition was prepared. The numbers in Table 1 below indicate parts by mass. Moreover, the blank in Table 1 below means no blending.

  The details of each component in Table 1 are as follows.

(A) Carboxyl group-containing photosensitive resin / KAYARAD ZAR-2000, KAYARAD ZCR-1569H: Nippon Kayaku Co., Ltd.
(B) Photopolymerization initiator / NCI-831: ADEKA Corporation
(C) Reactive Diluent-EBECRYL 8405: Daicel Cytec Corporation (D) Epoxy Compound-EPICLON 850-S: DIC Corporation
・ NC-3000: Nippon Kayaku Co., Ltd.

Carbon black MA-14, MA-7: Mitsubishi Chemical Corporation
・ Denka Black: Electrochemical Industry Co., Ltd.

Extender pigment, Heidilite H42M: Showa Denko K.K.
Flame Retardant Exolit OP-935: Clariant Japan Co., Ltd.
Curing accelerator, melamine: Nissan Chemical Co., Ltd.
-DICY-7: Mitsubishi Chemical Corporation
Antifoaming agent X-50-1095C: Shin-Etsu Chemical Co., Ltd.
Non-reactive diluent / EDGAC: Sanyo Chemicals Co., Ltd.

  The carbon black dispersion was carbon black (MA-14, MA-7) / urethane resin (urethane acrylate: EBECRYL 8405) / ethyl diglycol acetate / methoxypropyl acetate 15 parts by mass / 5 parts by mass / 77 parts by mass / 3. It was prepared by mixing and dispersing with a ball mill at a mass part ratio. The particle size distribution in Table 1 below was adjusted by controlling the ball mill operating conditions (grinding energy), bead diameter, and raw material supply speed. D50 and D95 were specified by measuring the particle size distribution with a dynamic light scattering type particle size measuring device ("Laser diffraction particle size analyzer LS130" manufactured by COULTER).

Test piece preparation process A substrate for a flexible wiring board in which a circuit pattern is formed on a polyimide film (Toray DuPont Co., Ltd. “Kapton 100H”) is surface-treated with dilute sulfuric acid (3 mass%), and then screen printed. After applying the black photosensitive resin composition prepared as described above, preliminary drying was performed at 80 ° C. for 20 minutes in a BOX furnace. After preliminary drying, the coating film was exposed to 100 mJ / cm ² with an exposure apparatus (Oak Co., Ltd. “HMW-680GW”), developed with 1% by weight sodium carbonate developer at 30 ° C., and then a BOX furnace. A cured coating film was formed on the substrate by curing at 150 ° C. for 60 minutes. The thickness of the cured coating film (DRY film thickness) was 20 μm.

The evaluation items are as follows.
(1) Transmittance A cured coating film of a black photosensitive resin composition was formed on a glass plate so as to have a DRY film thickness of 20 μm in accordance with the above test piece preparation step. Then, the transmittance | permeability of wavelength 400nm was measured by making the transmittance | permeability of a glass plate into a base line (measuring apparatus: UV spectrophotometer U-3310 (Hitachi High Technology Co., Ltd.)).

(2) Sensitivity According to the above test piece preparation process, a step tablet for sensitivity measurement (Kodak Co., Ltd., 21 steps) is installed on the coated substrate after preliminary drying at 80 ° C. for 20 minutes. Using a tablet as a test piece, irradiated with ultraviolet light (main peak wavelength 365 nm) through a tablet and irradiated with 100 mJ / cm ² using an integrating light meter (Oak Corp.), a 1% by weight sodium carbonate aqueous solution was developed. Development was performed for 60 seconds at a spray pressure of 2.0 kg / cm ² . The portion of the exposed portion after development that is not removed is represented by a number (number of steps). The larger the number of steps, the better the photosensitive characteristics.

(3) Resolution According to the above test piece preparation step, the pre-dried coating film on the copper-clad laminate is exposed through a photomask (line 30 to 130 μm) so that the DRY film thickness is 30 μm. A cured coating film of the black photosensitive resin composition was formed. The remaining line of the formed exposed part was visually confirmed and evaluated.

(4) Insulation reliability In accordance with the above test piece preparation process, using IPC-TM-650 IPC-SM840B B-25 test coupon comb-shaped electrode, 85 ° C., 85% R.D. H. The insulation resistance after humidifying for 200 hours was measured by applying DC 50V.
A: 1.0 × 10 ¹³ Ω or more.
○: The insulation resistance value is 1.0 × 10 ¹² Ω or more and less than 1.0 × 10 ¹³ Ω.
Δ: Insulation resistance value is 1.0 × 10 ¹⁰ Ω or more and less than 1.0 × 10 ¹² Ω.
×: Insulation resistance value is less than 1.0 × 10 ¹⁰ Ω.

  The results of the evaluation are shown in Table 1 below.

  As shown in Table 1 above, in Examples 1 to 8 in which a carbon black dispersion was blended in place of carbon black, the transmittance was 15% or less and the resolution was 110 μm or less. A cured coating film having resolution could be obtained. Sensitivity and insulation reliability were also obtained. In particular, from the comparison between Examples 1 and 2 and Examples 3 and 4, when a carbon black dispersion in which D50 of carbon black is 0.23 to 0.27 μm is blended, D50 of carbon black is 0.15 to 0.17 μm. Compared with the carbon black dispersion, the resolution was further improved despite the large amount of carbon black. Further, from Examples 3 and 4, the carbon black dispersion having a carbon black D50 of 0.23 μm and D95 of 0.56 μm was compared with the carbon black dispersion having a carbon black D50 of 0.27 μm and D95 of 0.68 μm. However, the same hiding power and resolution could be obtained with a small amount of formulation. Further, from comparison between Examples 3 and 5 and Example 6, in the carbon black dispersion in which D50 of carbon black is 0.27 μm and D95 is 0.68 μm, D50 of carbon black is 0.23 μm and D95 is 0.56 μm. The carbon black dispersion and carbon black dispersion having a D50 of 0.15 μm and a D95 of 0.40 μm were able to obtain better resolution. In addition, from comparison between Examples 1 to 6 and Examples 7 and 8, as the carboxyl group-containing photosensitive resin, a polybasic acid-modified radical polymerizable unsaturated monocarboxylic oxide epoxy resin was used, and the carboxyl group-containing photosensitive resin was When biphenyl aralkyl type epoxy resin was used as the basic skeleton, the insulation reliability was further improved. Furthermore, from the comparison between Example 7 and Example 8, as the epoxy compound, the same epoxy resin type as the epoxy resin type (biphenylaralkyl type epoxy resin in Examples 7 and 8) used as the basic skeleton of the carboxyl group-containing photosensitive resin. In Example 8, the resolution was further improved when biphenyl aralkyl epoxy resin was used.

  On the other hand, in Comparative Examples 1 to 3 in which powdery carbon black was directly blended into the resin composition, either the transmittance (hiding power) or the resolution was not sufficient.

  In the black photosensitive resin composition of the present invention, a cured product having excellent resolution and hiding power can be obtained without impairing basic characteristics such as sensitivity and insulation reliability. The utility value is high in the field of insulating coatings (for example, solder resist films) to be applied.

Claims (7)

  Containing (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, and (E) a carbon black dispersion. A black photosensitive resin composition.   The carbon black contained in the carbon black dispersion (E) has a particle size (D50) having a cumulative volume percentage of 50% by volume of 0.50 μm or less and a particle size (D95) having a cumulative volume percentage of 95% by volume of 1. It is 0 micrometer or less, The black photosensitive resin composition of Claim 1 characterized by the above-mentioned.   The carbon black contained in the carbon black dispersion (E) has a cumulative volume percentage of 50% by volume (D50) of 0.20 to 0.30 μm and a cumulative volume percentage of 95% by volume (D95). The black photosensitive resin composition according to claim 1, wherein is 0.40 to 0.60 μm.   The black photosensitive resin composition according to any one of claims 1 to 3, wherein the (E) carbon black dispersion contains carbon black, a resin, and an organic solvent.   The black photosensitive resin composition according to any one of claims 1 to 4, wherein the carbon black dispersion (E) contains 5.0 to 50% by mass of carbon black.   The black photosensitive resin composition according to any one of claims 1 to 5, wherein the carbon black contained in the carbon black dispersion (E) contains furnace black.   The black photosensitive resin composition according to claim 6, wherein the furnace black has an average primary particle size of 20 to 80 nm and a pH of 2.0 to 8.0.