JP2011225798A - Thermosetting resin composition, cured material of the same and printed wiring board using the cured material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition capable of realizing a cured material having a good preservation stability and resolution, and also having a good flex resistance, coated film hardness and electrical insulation, its cured material and a printed wiring board using the cured material.SOLUTION: This thermosetting resin composition is characterized by containing (A) a solid epoxy resin having a structure of general formula (i) [wherein, X is -CH- or -C(CH)-; Y is a group expressed by formula (A); and Z is H or a glycidyl group; and (n) is an integer of 1 to 12], (B) an acid anhydride-based curing agent, (C) a curing accelerator and (D) a powdery urethane resin, wherein, the acid anhydride of the acid anhydride-based curing agent is within the range of 0.5 to 1.5 equivalent based on the one equivalent of the epoxy group contained in the solid epoxy resin.

Description

  The present invention relates to a thermosetting resin composition, a cured product thereof, and a printed wiring board using the cured product.

  An epoxy resin composition containing an epoxy resin and a curing agent as an essential component exhibits excellent heat resistance and insulation in the cured product, and is therefore widely used in electronic component applications such as semiconductors and printed wiring boards. .

  For example, Patent Document 1 contains an epoxy resin, an acid anhydride curing agent, an accelerator, and a thermoplastic resin such as an ethylene-vinyl chloride copolymer resin and a vinylidene chloride resin, and has impact resistance, flexibility, and adhesiveness. And a thermosetting epoxy resin composition with improved impregnation properties.

  Patent Document 2 contains (A) a liquid epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) a hygroscopic agent, and is excellent in non-voidability, storage stability, and solder connectivity. An epoxy resin composition suitable for a no-flow manufacturing method of a flip-chip type semiconductor device is disclosed.

Japanese Patent Laid-Open No. 61-26317 JP 2008-274080 A

  By the way, when manufacturing a printed wiring board using a thermosetting resin composition, the hardened | cured material of the said thermosetting resin composition has sufficient bending resistance (flexibility), coating-film hardness, and electrical insulation. In particular, when a thermosetting resin composition is applied by a screen printing method, a dense print pattern is formed if the thermosetting resin composition does not have good resolution. I can't do it.

  Furthermore, a thermosetting resin composition containing an epoxy resin as a main agent and a curing agent as an auxiliary agent may easily have a problem in storage stability because the main agent and the auxiliary agent are easily cured by contact. There are many demands for thermosetting resin compositions that can be easily stored.

  At present, a thermosetting resin composition that satisfies all the requirements for these properties has not been provided.

  Therefore, the present invention provides a thermosetting resin composition that has a good storage stability and resolution, and can realize a cured product having good bending resistance, coating film hardness, and electrical insulation. The object is to provide goods.

  Another object of the present invention is to provide a cured product of the thermosetting resin composition and a printed wiring board using the cured product.

（式中、Ｘは−ＣＨ_２−又は−Ｃ（ＣＨ_３）_２−を表し、Ｙは、

を表し、Ｚは、水素原子又はグリシジル基を表し、ｎは１〜１２の整数を表す。）
（２）前記硬化促進剤（Ｃ）として、下記式（ｉｉ）で表される化合物及び／又は下記式（ｉｉｉ）で表される化合物を含む、（１）に記載の熱硬化性エポキシ樹脂組成物。

（３）さらに、シリカ粒子（Ｅ）を含むことを特徴とする、（１）又は（２）に記載の熱硬化性樹脂組成物。
（４）さらに、着色剤（Ｆ）を含むことを特徴とする、（１）〜（３）何れかに記載の熱硬化性樹脂組成物。
（５）スクリーン印刷用である、（１）〜（４）何れかに記載の熱硬化性樹脂組成物。
（６）（１）〜（５）いずれかに記載の熱硬化性樹脂組成物を基材上に塗布し、硬化して得られる硬化物。
（７）（６）に記載の硬化物を用いたプリント配線板。
（８）前記着色剤（Ｆ）が酸化チタンである、（４）に記載の熱硬化性樹脂組成物の硬化物を皮膜とする反射シート。
（９）（１）〜（５）何れかに記載の熱硬化性樹脂組成物を、スクリーン印刷法により基板に塗布し、硬化させる工程を有することを特徴とする、プリント配線板の製造方法。 In order to solve the above-described problems, the present invention provides the following (1) to (8).
(1) A solid epoxy resin (A) having the structure of the following general formula (i), an acid anhydride curing agent (B), a curing accelerator (C), and a powder urethane resin (D) are blended. ,
The thermosetting resin composition characterized in that the acid anhydride group of the acid anhydride curing agent is in the range of 0.5 to 1.5 equivalents relative to 1 equivalent of the epoxy group of the solid epoxy resin. .

(In the formula, X represents —CH ₂ — or —C (CH ₃ ) ₂ —, and Y represents

Z represents a hydrogen atom or a glycidyl group, and n represents an integer of 1 to 12. )
(2) The thermosetting epoxy resin composition according to (1), comprising a compound represented by the following formula (ii) and / or a compound represented by the following formula (iii) as the curing accelerator (C). object.

(3) The thermosetting resin composition according to (1) or (2), further comprising silica particles (E).
(4) The thermosetting resin composition according to any one of (1) to (3), further comprising a colorant (F).
(5) The thermosetting resin composition according to any one of (1) to (4), which is for screen printing.
(6) Hardened | cured material obtained by apply | coating the thermosetting resin composition in any one of (1)-(5) on a base material, and hardening.
(7) A printed wiring board using the cured product according to (6).
(8) The reflective sheet which uses as a film | membrane the hardened | cured material of the thermosetting resin composition as described in (4) whose said colorant (F) is a titanium oxide.
(9) A method for producing a printed wiring board, comprising a step of applying the thermosetting resin composition according to any one of (1) to (5) to a substrate by a screen printing method and curing the composition.

  The thermosetting resin composition of the present invention has good storage stability and resolution. Moreover, since the cured product of the thermosetting resin composition of the present invention has good flex resistance (flexibility), coating film hardness, and electrical insulation, a protective coating (solder resist) for printed wiring boards. Useful as.

  Hereinafter, the present invention will be described with reference to embodiments.

[Thermosetting resin composition]
Hereinafter, each component of the thermosetting resin composition according to the present invention will be described in detail.
Solid epoxy resin (A)
The solid epoxy resin (A) is an epoxy resin that is solid at normal temperature (25 ° C.) represented by the following general formula (i).

を表し、Ｚは、水素原子又はグリシジル基を表し、ｎは１〜１２の整数を表す。 Here, in the formula, X represents —CH ₂ — or —C (CH ₃ ) ₂ —, and Y represents

Z represents a hydrogen atom or a glycidyl group, and n represents an integer of 1 to 12.

  As an epoxy equivalent of a solid epoxy resin (A), it is preferable to use the thing of the range of 250-3300 g / eq, Furthermore, 400-2500 g / eq from a viewpoint which makes easy adjustment of a compounding quantity.

  Moreover, the compounding quantity of solid epoxy resin (A) is 25-75 mass% with respect to the whole thermosetting resin composition from a viewpoint of bending resistance and heat resistance, Furthermore, the range of 25-65 mass% is preferable. .

  The solid epoxy resin (A) may be a commercially available one or a suitably synthesized one. Specific examples of commercial products of the solid epoxy resin (A) include Epicoat 1001, Epicoat 1004 (all manufactured by Japan Epoxy Resin), YDF-2001 (manufactured by Tokyo Chemical Industry), and ST-5080 (manufactured by Tohto Kasei). .

Acid anhydride curing agent (B)
The acid anhydride curing agent used in the present invention is not particularly limited as long as it has an acid anhydride group in the molecule, and is an acid anhydride that is usually used as a curing agent for epoxy resins. Can be widely used, for example, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhymic anhydride, pyromellitic dianhydride, maleated alloocimene, benzophenonetetracarboxylic dianhydride 3,3 ′, 4,4′-biphenyltetrabisbenzophenonetetracarboxylic dianhydride, (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 3,4-dimethyl-6- (2- Til-1-propenyl) -1,2,3,4-tetrahydrophthalic anhydride and 1-isopropyl-4-methyl-bicyclo [2.2.2] oct-5-ene-2,3- Dicarboxylic acid anhydride can be preferably used.

（式（ｉｖ）において、点線は二重結合となっていても良い箇所を示し、Ｒ^１は水素原子又はメチル基を意味する。また、式（ｖ）において、Ｒ^２は−ＯＡｃ（Ａｃ：アセチル）により置換されていても良い、炭素数１〜５の二価の炭化水素基を意味する。） Particularly preferred acid anhydride curing agents are one or more compounds represented by the following general formulas (iv) and (v).

(In the formula (iv), the dotted line indicates a portion which may be a double bond, and R ¹ represents a hydrogen atom or a methyl group. In the formula (v), R ² represents —OAc (Ac: A divalent hydrocarbon group having 1 to 5 carbon atoms, which may be substituted by acetyl).

  Specific examples of the compound represented by the formula (iv) or (v) include Ricacid TH, Ricacid HT-1, Ricacid HH, Ricacid MH-700, and Ricacid MT-500 (all manufactured by Shin Nippon Rika Co., Ltd.) Is given.

  The acid anhydride equivalent of the acid anhydride curing agent is preferably 140 to 240 g / eq, more preferably 150 to 230 g / eq, from the viewpoint of easy adjustment of the blending amount.

  In the thermosetting resin composition according to the present invention, the acid anhydride of the acid anhydride curing agent is 0.5 to 1.5 equivalents relative to 1 equivalent of the epoxy group of the solid epoxy resin (A), It is preferable to mix | blend a solid epoxy resin (A) and an acid anhydride hardening | curing agent so that it may become 0.8-1.2 equivalent. If the acid anhydride is less than 0.5 equivalent, the flexibility and coating film hardness of the cured product may be reduced. Moreover, when it exceeds 1.5 equivalent, there exists a possibility that the storage stability of a thermosetting resin composition and the coating-film hardness of hardened | cured material may fall.

  Moreover, the compounding quantity of an acid anhydride hardening | curing agent (B) is 5-30 mass% with respect to the whole thermosetting resin composition from a viewpoint of bending resistance and heat resistance, Furthermore, the range of 10-25 mass% Is preferred.

Curing accelerator (C)
The curing accelerator used in the thermosetting resin composition of the present invention is not limited as long as it normally functions as a curing accelerator for epoxy resins, and two or more curing accelerators may be used in combination. . Specifically, 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2 -Methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6- [2'-methylimidazole- (1 ' )] Ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazole- (1 ')] ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl, 4 -Methylimidazole- (1 ')] ethyl-s-triazine, 2,4-diamino-6- [2'-methylimi Dazole- (1 ′)] ethyl-s-triazine isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2: 3 adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethyl Various imidazoles such as imidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole, and imidazoles and phthalic acid, isophthalic acid, terephthalic acid Acids, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, maleic acid, salts with polyvalent carboxylic acids such as succinic acid, amides such as dicyandiamide, 1,8-diaza-bicyclo (5.4.0) undecene Diaza compounds such as 7 and phenols of the above compounds , Polycarboxylic acids, salts with tetraphenylborate, or salts with phosphinic acids, ammonium salts such as tetrabutylammonium bromide, cetyltrimethylammonium bromide, trioctylmethylammonium bromide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate And other phosphines, phenols such as 2,4,6-trisaminomethylphenol, amine adducts, and microcapsule type curing accelerators in which these curing accelerators are made into microcapsules.

Further, from the viewpoint of storage stability of the thermosetting resin composition, a particularly preferable curing agent is any one or both of the compounds (salts) represented by the following formulas (ii) and (iii).

  A hardening accelerator is 0.01-5 mass parts normally with respect to 100 mass parts of solid epoxy resins (A), Furthermore, it is used in 0.05-0.2 mass part. From the standpoint of stability over time, it is particularly preferable to use at 0.1 to 0.2 parts by mass.

Powder urethane resin (D)
In the thermosetting resin composition of the present invention, known polyurethane fine particles can be used as the powder urethane resin (D). The shape of the particles may be indefinite, spherical or spherical. As the particle diameter, polyurethane fine particles having a particle size of 0.1 to 30 μm, preferably 1 to 10 μm are suitable. When the particle size is 0.1 μm or less, it is difficult to reduce the elastic modulus and sufficient flexibility cannot be obtained. On the other hand, when the particle size is 30 μm or more, sufficient flexibility can be obtained by reducing the elastic modulus, but the particle size is large. Therefore, it is not preferable because fine image formation cannot be obtained. Such polyurethane fine particles are obtained by mechanically pulverizing solid polyurethane at low temperature, by precipitation and drying from an aqueous polyurethane emulsion, by spray drying, and by adding a poor solvent to solution-polymerized polyurethane to form a granular polyurethane. It can be prepared by a method such as precipitation and filtration, drying and removing the solvent to produce. The surface of the fine particles may be coated with hydrophobic silica coating or fluorine compound-treated silica.

  The amount of the powdered urethane resin used is 1 to 30 parts by mass with respect to 100 parts by mass of the solid epoxy resin from the point of further improving elongation and folding resistance while further suppressing the occurrence of warpage in addition to elasticity. From the point which is excellent in the balance of each said characteristic, Preferably it is 3-18 mass parts. Examples of commercially available powdered urethane resins include “RHC-730” manufactured by Dainichi Seika Co., Ltd., “Art Pearl C-300” and “C-400” manufactured by Negami Kogyo Co., Ltd. “C-800”, “P-800T”, “U-600T”, “CF-600T”, “JB-400T”, “JB-800T”, “CE-400T”, “ “CE-800T”, “MM-120TW”, “C-400R” and the like.

Other components The thermosetting resin composition of the present invention contains, in addition to the above components, various additive components, for example, various additives, extenders, colorants, antifoaming agents, solvents and the like. Can be made.

  Examples of the additive include a dispersant such as a coupling agent such as silane, titanate, and alumina.

  The extender pigment is for increasing the physical strength of the cured film, and examples thereof include silica particles (E), barium sulfate, alumina, aluminum hydroxide, talc, and mica.

  In particular, in order to improve resolution in the screen printing method, it is preferable to add silica particles (E) to the thermosetting resin composition.

The silica particles added for this purpose are not particularly limited, but those having a specific surface area of 50 to 400 m ² / g and a primary average particle diameter of 7 to 40 nm are preferable. As the silica particles, any silica produced by a so-called pyrolysis method (fumed) or a sol-gel method can be suitably used. Further, from the viewpoint of improving dispersibility, the surface of the silica particles is preferably hydrophobized with a surface treating agent, and in particular, the surface treated with dimethyldichlorosilane is preferred. As a compounding quantity of a silica particle, the range of 0.01-10 mass parts with respect to 100 mass parts of solid epoxy resins (A), Furthermore, the range of 0.1-0.5 mass part is preferable.

  Specific examples of the hydrophilic fumed silica include AEROSIL90, AEROSIL130, AEROSIL150, AEROSIL200, AEROSIL300, AEROSIL380, AEROSIL OX50, AEROSIL EG50, AEROSIL TT600, manufactured by Nippon Aerosil Co., Ltd. QS-10L, QS-10, QS-102, CP-102, QS-20L, QS-20, QS-25C, QS-30, QS-30C, QS-40, etc. are mentioned. Specific examples of the hydrophobic fumed silica include AEROSIL R972, AEROSIL R974, AEROSIL R104, AEROSIL R106, AEROSIL R202, AEROSIL R805, AEROSIL R812, AEROSIL R816, AEROSIL R8200, AEROSIL, manufactured by Nippon Aerosil Co., Ltd. AEROSIL R9200, AEROSIL RY50, AEROSIL NY50, AEROSIL RY200, AEROSIL RY200S, AEROSIL RX50, AEROSIL NAX50, AEROSIL RX200, AEROSIL RX300, AEROSIL R504, AEROSIL DT4, MT 10C, DM-10, DM-10C, DM-20S, DM-30, DM-30S, KS-20S, KS-20SC, HM-20L, HM-30S, PM-20L and the like.

  As the colorant, known color pigments can be used, and examples thereof include phthalocyanine-based organic pigments such as phthalocyanine green and phthalocyanine blue, anthraquinone-based and azo-based organic pigments, and inorganic pigments such as titanium oxide and carbon black.

  When the target color is white, titanium oxide particles having a rutile crystal structure are effective, and the coating film is whitened. The average particle size of the particles is not particularly limited, but may be a primary average particle size of 0.1 to 0.5 μm. Further, the surface treatment agent for rutile-type titanium oxide particles is not limited. Specifically, TR-600, TR-700, TR-750, TR-840 manufactured by Fuji Titanium Industry Co., Ltd., R-550, R-580, R-630, R-820 manufactured by Ishihara Sangyo Co., Ltd., CR-50, CR-60, CR-90, KR-270, KR-310, KR-380, etc. manufactured by Titanium Industry Co., Ltd. can be used.

  When the target color is black, C.I. I. Pigment Black 6, 7, 9 and 18, etc., carbon black pigments, C.I. I. Pigment Black 8, 10, etc., a graphite pigment, C.I. I. Pigment Black 11, 12 and 27, etc .: iron oxide pigments such as KN-370 iron oxide manufactured by Toda Kogyo Co., Ltd., 13M titanium black manufactured by Mitsubishi Materials Corporation, C.I. I. Anthraquinone pigments such as C.I. Pigment Black 20; I. Pigment Black 13, 25, 29 and the like, cobalt oxide pigments such as C.I. I. Pigment Black 15 and 28 and the like, copper oxide pigments such as C.I. I. Pigment Black 14 and 26 and the like, manganese-based pigments such as C.I. I. Antimony oxide pigments such as C.I. Pigment Black 23; I. A pigment of nickel oxide represented by Pigment Black 30 or the like; I. Perylene pigments represented by Pigment Black 31 and 32, molybdenum sulfide and bismuth sulfide can also be exemplified as suitable pigments.

  When blue is the target color, Pigment Blue 15, Pigment Blue 15: 1, Pigment Blue 15: 2, Pigment Blue 15: 3, Pigment Blue 15: 4, Pigment Blue 15: 6, Pigment Blue Blue, Pigment Blue 15 Blue 35, Solvent Blue 63, Solvent Blue 68, Solvent Blue 70, Solvent Blue 83, Solvent Blue 87, Solvent Blue 94, Solvent Blue 97, Sol Blu 122, Sol 67 Blue 122, Sol 36 That.

  When green is the target color, Pigment Green 7, Pigment Green 10, Pigment Green 18, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green, etc. can be used.

  If Yellow is the target color, Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 199, Pigment Yellow 202, Pigment Yellow 202, Pigment Yellow 199, Pigment Yellow 199 , Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202, Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 12 , Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180, Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow 181, Pigment Yellow 12,, etc. Pigment Yellow198 like.

  When red is the target color, Pigment Red 1, Pigment Red 2, Pigment Red 3, Pigment Red 17, Pigment Red 37, Pigment Red 37, Pigment Red 48: 1, Pigment Red 48: 3, Pigment Red 50: 1, Pig 53 1, Pigment Red 57: 1,68 Solvent Red 135, Solvent Red 179, Pigment Red 123, Pigment Red 149, Pigment Red 166, Pigment Red 178, Pigment Red 179, Pigment Red 179, Pigment Red 179, Pigment Red 179, Pigment Red 179, Pigment Red 179, 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207, and the like.

  In addition, the following purple, orange, brown, black and other colorants can be used. For example, Pigment Violet 19, Pigment Violet 23, Pigment Violet 29, Pigment Violet 32, Solvent Violet 13, Solvent Violet 36, C.I. I. Pigment Orange 1, C.I. I. Pigment Orange 5, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 17, C.I. I. Pigment Orange 40, C.I. I. Pigment Brown 23 and the like. In addition, the above coloring agent is normally used in 0.001-30 mass parts with respect to 100 mass parts of solid epoxy resins (A), and even if it uses independently, 2 or more can also be mixed.

  Moreover, a well-known thing can be used for an antifoamer, For example, a silicone type, a hydrocarbon type, an acrylic type etc. can be mentioned.

  As the solvent, an organic solvent is suitable, for example, ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, cyclohexane, methylcyclohexane and the like. Aliphatic hydrocarbons, petroleum solvents such as petroleum ether and petroleum naphtha, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate And acetate esters such as carbitol acetate, butyl carbitol acetate, and diethylene glycol monoethyl ether acetate. When an organic solvent is used, the amount used is preferably 10 to 500 parts by mass, more preferably 10 to 100 parts by mass, and still more preferably 30 to 50 parts by mass with respect to 100 parts by mass of the solid epoxy resin (A). Part.

  The manufacturing method of the thermosetting composition according to the above-described embodiment of the present invention is not limited to a specific method. For example, after blending each of the above components at a predetermined ratio, the mixture is dispersed and dispersed at room temperature with a three roll. Can be manufactured.

[Hardened product (cured film), printed wiring board and method for producing the same]
The printed wiring board according to the present invention is a printed wiring board having a cured film of the thermosetting resin composition of the present invention. Note that the printed wiring board includes both those not mounted with electronic components and those mounted.

  In order to form a cured film, for example, a printed wiring board having a circuit pattern formed by etching a copper foil of a thermosetting resin composition according to an embodiment of the present invention obtained as described above ( The substrate is applied to a desired thickness using a screen printing method, curtain coating method, roll coating method, spray coating method, etc., and pre-dried by heating at a temperature of about 60 to 80 ° C. for about 15 to 60 minutes. Do. Thereafter, the applied thermosetting resin composition is post-cured for 5 to 80 minutes using a hot-air circulating dryer or the like at 130 to 170 ° C. to form a target solder resist film on the printed wiring board. be able to. In addition, as a coating method, the coating method by a screen printing method is suitable as mentioned above.

The cured film of the present invention thus obtained has excellent bending resistance, coating film hardness, and electrical insulation. The coating film hardness (JIS K-5600-5-4) is usually in the range of 2H to 6H, although it depends on the heating conditions. The surface electrical insulation resistance (JIS C 5016) is usually in the range of 1.1 to 2.2 × 10 ¹² Ω, and the interlayer electrical insulation resistance (JIS C 6471) is usually 0.6 to 1.2 ×. The range is 10 ¹² Ω.

  An electronic circuit unit is formed by soldering an electronic component to the printed wiring board covered with the cured film obtained as described above by a jet soldering method, a reflow soldering method, or the like.

  [Reflection sheet]

  Further, by adding a titanium oxide such as rutile-type titanium oxide to the thermosetting resin composition of the present invention described above, a white thermosetting resin composition is obtained, and this white thermosetting resin composition A reflective sheet can be obtained by coating on a sheet-like base film. For example, the said reflection sheet is arrange | positioned on the back surface side of a solar cell module, ie, the surface on the opposite side to the surface which receives solar radiation. Then, since the sunlight that has passed through the solar cell module without being received by the power generation element of the solar cell module is reflected by the reflection sheet and returned from the back side of the solar cell module to the inside of the solar cell module, the solar cell The power generation efficiency of the module is improved. In addition, the installation method of the reflective sheet to a solar cell module back surface includes the method of sticking directly on a solar cell module back surface using an adhesive agent or an adhesive tape, for example. As a compounding agent of the titanium oxide in this case, the range of 30-250 mass parts, 50-220 mass parts, and also 150-200 mass parts is preferable with respect to 100 mass parts of solid epoxy resins (A).

  The material of the base film to which the white thermosetting resin composition is applied is not particularly limited. For example, polyimide, polyethylene terephthalate (PET), polyvinyl fluoride (PVF), fluorinated ethylene / propylene copolymer (FEP) Polytetrafluoroethylene (PTFE), aramid, polyamide-imide, epoxy, polyetherimide, polysulfone, polyethylene naphthalate (PEN), liquid crystal polymer (LCP), and the like.

  The method for coating the white curable resin composition on the sheet-like base film is not particularly limited, and the same method as described above can be employed. Further, for example, after treating the surface of a polyethylene terephthalate film having a thickness of 40 μm with 3% sulfuric acid and washing the surface, a white curable resin composition is predetermined on the washed surface using a known printing method such as screen printing. The coating is performed such that the film thickness after curing, for example, the film thickness after curing is 20 to 23 μm. The white curable resin composition is coated on the entire or substantially entire surface of the base film facing the back surface of the solar cell module. After coating, preliminary drying is performed by heating at a temperature of about 60 to 80 ° C. for about 15 to 60 minutes. Subsequently, the target white film | membrane can be formed on a sheet-like base film by performing a postcure for 5 to 80 minutes at the temperature of about 130-170 degreeC.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not restrict | limited by these Examples.
(1) Preparation method of evaluation sample (1-1) Examples 1 to 13 and Comparative Examples 1 to 5
Each composition was mixed and dispersed in a composition (weight ratio) described in Table 1 using three rolls (manufactured by Inoue Seisakusho, S16) in an air atmosphere and at room temperature. A composition was prepared. Subsequently, the cured coating film was produced on the following conditions using each composition.

<Method for forming cured coating film>
The surface of the printed circuit board was subjected to buffing, followed by washing with a 3% sulfuric acid aqueous solution and drying, followed by surface treatment. Thereafter, the resin composition is applied to a printed circuit board by a screen printing method, and the coating film is used at 70 ° C. for 20 minutes (inside the furnace: 25 minutes) using a hot air circulating drying oven (manufactured by Tabai Espec, (model number) PHH201) ) Dried to form a dry coating film having a thickness of 20 to 23 μm. Next, heat curing was carried out at 150 ° C. for 10 minutes (in the furnace: 15 minutes) using a hot air circulating drying furnace to form a cured coating film.
(1-2) Examples 14 to 16, Comparative Example 6 and Comparative Example 7 (Reflective Sheet)
Each compound was mixed and dispersed with three rolls at a weight ratio shown in Table 3 to prepare a white curable resin composition. After the surface of a 38 μm thick polyethylene terephthalate film (“Lumirror” manufactured by Toray Industries, Inc.) is treated with a 3% sulfuric acid aqueous solution to clean the surface, a white curable resin composition is prepared so that the DRY film thickness is 20 to 23 μm. Then, it was applied to one whole surface of the polyethylene terephthalate film by a screen printing method, and a cured coating film was prepared under the same UV irradiation and heat treatment conditions as in the above (1-1) to obtain a test piece. As for the reflectance, in order to eliminate the influence of deterioration of the polyethylene terephthalate film itself due to the environmental standing as an accelerated test, a cured coating is applied on a glass plate (1.2 mm thickness) in the same manner instead of the polyethylene terephthalate film. A film was formed and evaluated.

(2) Evaluation method (2-1) Storage stability Viscosity measurement (25 degreeC) is performed for the said resin composition with a Brookfield viscometer, The viscosity increase rate after 50 degreeC-7 days is calculated | required with a thermostat, Evaluation was made according to the following criteria.

  Thickening rate ◎: Less than 1.1, ○: 1.1 or more and less than −1.2, Δ: 1.2 or more and less than −1.5, ×: 1.5 or more

(2-2) Bending resistance A test piece in which a cured coating film is formed on the flexible substrate (Espanex thickness 50 μm, copper foil thickness 18 μm, manufactured by Nippon Steel Chemical Co., Ltd.) having a copper foil on one side is formed by the cylindrical mandrel method. According to JIS K5600-5-1, the flexibility of the coating film was observed visually and with an optical microscope of x200, and evaluated according to the following criteria.

  ○: No abnormality at a diameter of 4 mm or less, △: No abnormality at a diameter of 6 mm, but abnormalities such as cracking and peeling at a diameter of 4 mm or less, ×: Abnormalities such as cracking and peeling at a diameter of 6 mm or more

(2-3) Coating film hardness The pencil hardness of the cured coating film on the copper foil was evaluated according to the test method of JIS K-5600-5-4. The coating film hardness was measured both after heating at 70 ° C. for 20 minutes and after heating at 150 ° C. for 20 minutes in the cured coating film forming method.

(2-4) Resolution Using a screen printing apparatus (manufactured by Tokai Seiki Co., Ltd., SERIA), the minimum aperture diameter (φ) that can form a circular pattern without causing bleeding of the coating film is defined as the resolution value. did.

(2-5) Electrical insulation (2-5-1) Surface electrical insulation resistance An electrical insulation test coupon described in JIS C 5016 was produced by etching (Espanex, manufactured by Nippon Steel Chemical Co., Ltd., thickness 50 μm, copper foil thickness 18 μm). Using the test coupon obtained by coating the thermosetting resin composition with a thickness of 20 μm by the above-described method, 85 ° C., 85% R.D. H. The electrical insulation resistance after humidifying for 1000 hours was measured by applying DC 100V.

(2-5-2) Interlayer Electrical Insulation Resistance A circular electrode (φ83 mm) test coupon described in JIS C 6471 was prepared by etching (Espanex, manufactured by Nippon Steel Chemical Co., Ltd., thickness 50 μm, copper foil thickness 18 μm). After the thermosetting resin composition described above was formed on the electrode (thickness: 40 μm), a silver paste (Tamura Kaken Co., Ltd., Alzelite) was applied in a circular shape (φ50 mm) on the coupon, Using the dried one, 85 ° C., 85% R.D. H. The interlayer electrical insulation resistance between the electrodes after humidifying for 1000 hours was measured by applying DC 100V.

(2-6) Reflectance Using a spectrophotometer U-3410 (manufactured by Hitachi, Ltd .: φ60 mm integrating sphere), the reflectance at 450 nm of the test piece coated with the cured coating film was measured. “Initial” means immediately after the preparation of the evaluation test piece, and “after warming and humidification” means that after the preparation of the evaluation test piece, it is left at 85 ° C. and 85% RH for 1000 hours.

(3) Evaluation results The evaluation results of each thermosetting resin composition are shown in Tables 1 and 2 below. As is clear from Tables 1 and 2, it can be seen that the thermosetting resin composition according to the present invention is excellent in storage stability and resolution. Furthermore, all the cured coating films of the thermosetting resin composition according to the present invention have excellent flex resistance. Moreover, the coating film hardness is 2H or more under the condition of 70 ° C.-20 minutes, and 4H or more under the condition of 150 ° C.-10 minutes, indicating that the coating film hardness is excellent. In both cases, the surface insulation resistance was 1.2 × 10 ¹² Ω or more, and the interlayer insulation resistance was 0.7 × 10 ¹² Ω or more, indicating good electrical insulation.
On the other hand, in Comparative Example 1, since a liquid epoxy resin is used, the storage stability, the bending resistance, and the resolution are inferior. In Comparative Example 2, the acid anhydride group of the acid anhydride-based curing agent is less than 0.5 equivalent with respect to 1 equivalent of the epoxy group of the solid epoxy resin, so that the bending resistance and the coating film hardness are inferior. It is the result. In Comparative Example 3, since the acid anhydride group of the acid anhydride curing agent exceeds 1.5 equivalents relative to 1 equivalent of the epoxy group of the solid epoxy resin, the storage stability and the flex resistance are high. Inferior. In Comparative Example 4, since the curing accelerator is not included, the storage stability is good, but the bending resistance and the coating film hardness are inferior, and the surface insulation resistance and the interlayer insulation resistance cannot be measured. there were. In Comparative Example 5, since the powder urethane resin is not included, the bending resistance is poor.
As is apparent from Table 1, when the compound represented by the above general formula (ii) and / or the compound represented by (iii) is included as the curing agent, it can be seen that the storage stability is particularly excellent. Moreover, about Example 9-Example 12 containing a silica particle, resolution is especially favorable and it is especially suitable for screen printing methods especially among the thermosetting resin compositions which concern on this invention. I understand.
Furthermore, as is apparent from Table 3, the cured product of the curable composition of the present invention has excellent reflectance, coating film hardness, and good bending resistance, so that it is a reflective sheet for solar cell modules. It is also suitable.

リカシッドＴＭＴＡ−Ｃ：下記式（ｖｉｉ）で表される硬化剤（新日本理化株式会社製、酸無水物当量１６０ｇ／ｅｑ）

ＴＰＰ−Ｋ：硬化促進剤（テトラフェニルホスホニウム・テトラフェニルボレート、北興化学工業（株）製、酸無水物当量２２０ｇ／ｅｑ）
ＨＩＰＡ−２Ｐ４ＭＨＺ：上記一般式（ｉｉ）で表される硬化促進剤（日本曹達（株）製）
ＮＩＰＡ−２Ｐ４ＭＨＺ：上記一般式（ｉｉｉ）で表される硬化促進剤（日本曹達（株）製）
ＲＨＣ−７３０：粉末ウレタン樹脂（大日精化（株）製）
Ｒ−９７４：シリカ粒子（日本アエロジル（株）製）
カーボンブラック：着色剤（電気化学工業（株）製、デンカブラック）
Ｒ−６８０：着色剤（石原産業（株）製）
ジエチレングリコールモノエチルエーテルアセテート：溶剤（三洋化成工業（株）製） (Remarks)
Epicoat 1001: Solid epoxy resin represented by the above general formula (i) (manufactured by Japan Epoxy Resin, solid bisphenol A type epoxy resin, epoxy equivalent 450 g / eq, softening point 64 ° C.)
Epicoat 1004: Solid epoxy resin represented by the above general formula (i) (manufactured by Japan Epoxy Resin, solid bisphenol A type epoxy resin, epoxy equivalent 900 g / eq, softening point 97 ° C.)
Epicoat 1004FS: solid epoxy resin represented by the above general formula (i) (manufactured by Japan Epoxy Resin, high-purity solid bisphenol A type epoxy resin, epoxy equivalent 900 g / eq, softening 97 ° C.)
YDF-2001: Solid epoxy resin represented by the above general formula (i) (manufactured by Tohto Kasei, solid bisphenol F type epoxy resin, epoxy equivalent 500 g / eq, softening point 60 ° C.)
ST-5080: Solid epoxy resin represented by the above general formula (i) (manufactured by Tohto Kasei, solid hydrogenated bisphenol A type epoxy resin (epoxy equivalent 600 g / eq, softening point 80 ° C.)
Synthetic resin 1: solid epoxy resin represented by the above general formula (i) obtained by the following method <Synthesis method of synthetic resin 1>
410 parts by weight of YDF-2001 (solid bisphenol F type epoxy resin (epoxy equivalent 500 g / eq, softening point 60 ° C.) manufactured by Toto Kasei) was added to a mixture of 880 parts by weight of epichlorohydrin and 600 parts by weight of dimethyl sulfoxide and dissolved. . Next, while stirring the solution at 70 ° C., 50.6 g of 98.5% by weight sodium hydroxide was added over 100 minutes, and the reaction was further performed at 70 ° C. for 3 hours. Next, most of the excess unreacted epichlorohydrin and dimethyl sulfoxide are distilled off under reduced pressure, and the reaction product containing the by-product salt and dimethyl sulfoxide is dissolved in 750 g of methyl isobutyl ketone, and further 10 g of a 30 wt% aqueous sodium hydroxide solution. And reacted at 70 ° C. for 1 hour.
After completion of the reaction, after washing twice with 200 g of water, the layers were separated, methyl isobutyl ketone was distilled off from the oil layer, epoxy equivalent 290, hydrolyzable chlorine content 0.07% by weight, softening point 64.2 ° C. A synthetic resin 1 was obtained. The hydrolyzable chlorine content is determined by dissolving an epoxy resin in dioxane, adding a 1N-potassium hydroxide alcohol solution, and titrating with a silver nitrate aqueous solution the chlorine ions that are eliminated when heated at reflux for 30 minutes. The amount of chlorine atoms in the epoxy resin is expressed as a percentage by weight.
Epicoat 828: Liquid bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin, epoxy equivalent 180 g / eq, viscosity 120 poise (25 ° C.))
Rikacid MH-700G: Curing agent represented by the following formula (vi) (manufactured by Shin Nippon Rika Co., Ltd.)

Ricacid TMTA-C: a curing agent represented by the following formula (vii) (manufactured by Nippon Nippon Chemical Co., Ltd., acid anhydride equivalent 160 g / eq)

TPP-K: curing accelerator (tetraphenylphosphonium tetraphenylborate, manufactured by Hokuko Chemical Co., Ltd., acid anhydride equivalent 220 g / eq)
HIPA-2P4MHZ: Curing accelerator represented by the above general formula (ii) (manufactured by Nippon Soda Co., Ltd.)
NIPA-2P4MHZ: a curing accelerator represented by the above general formula (iii) (manufactured by Nippon Soda Co., Ltd.)
RHC-730: Powdered urethane resin (manufactured by Dainichi Seika Co., Ltd.)
R-974: Silica particles (manufactured by Nippon Aerosil Co., Ltd.)
Carbon black: Colorant (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.)
R-680: Colorant (Ishihara Sangyo Co., Ltd.)
Diethylene glycol monoethyl ether acetate: solvent (manufactured by Sanyo Chemical Industries, Ltd.)

Claims (9)

A solid epoxy resin (A) having a structure of the following general formula (i), an acid anhydride curing agent (B), a curing accelerator (C), and a powder urethane resin (D) are blended,
The thermosetting resin composition characterized in that the acid anhydride group of the acid anhydride curing agent is in the range of 0.5 to 1.5 equivalents with respect to 1 equivalent of the epoxy group of the solid epoxy resin. object.

(In the formula, X represents —CH ₂ — or —C (CH ₃ ) ₂ —, and Y represents

Z represents a hydrogen atom or a glycidyl group, and n represents an integer of 1 to 12. ) The thermosetting epoxy resin composition according to claim 1, comprising a compound represented by the following formula (ii) and / or a compound represented by the following formula (iii) as the curing accelerator (C).

  The thermosetting resin composition according to claim 1, further comprising silica particles (E).   Furthermore, a coloring agent (F) is included, The thermosetting resin composition in any one of Claims 1-3 characterized by the above-mentioned.   The thermosetting resin composition according to any one of claims 1 to 4, which is for screen printing.   Hardened | cured material obtained by apply | coating the thermosetting resin composition in any one of Claims 1-5 on a base material, and hardening | curing.   A printed wiring board using the cured product according to claim 6.   The reflective sheet which uses the hardened | cured material of the thermosetting resin composition of Claim 4 whose film | membrane is a titanium oxide as a film | membrane.   A method for producing a printed wiring board, comprising: applying the thermosetting resin composition according to claim 1 to a substrate by a screen printing method and curing the composition.