JP5234962B2 - Prepreg, laminated board and printed wiring board - Google Patents

Description

  The present invention relates to an epoxy resin composition excellent in high thermal conductivity, low thermal expansion, high heat resistance and low hygroscopicity, a prepreg to which the epoxy resin composition is applied, and a laminate or printed wiring board using the prepreg.

  As an epoxy resin composition excellent in high thermal conductivity, one using an epoxy resin having a mesogenic structure is known. For example, JP-A-7-90052 discloses a biphenol type epoxy resin and a polyhydric phenol resin. An epoxy resin composition containing a curing agent as an essential component is shown, and it is disclosed that it is excellent in stability and strength at high temperatures and can be used in a wide range of fields such as adhesion, casting, sealing, molding and lamination. Japanese Patent Application Laid-Open No. 9-118673 discloses an epoxy compound having two mesogenic structures connected by a bent chain in the molecule. Further, JP-A-11-323162 discloses a resin composition containing an epoxy compound having a mesogenic group.

Japanese Patent Laid-Open No. 7-90052 JP-A-9-118673 JP-A-11-323162 JP 2004-123847 A

  However, an epoxy resin having such a mesogenic structure has a high melting point and is extremely insoluble in an organic solvent. High temperature is required to uniformly mix such an epoxy resin with a curing agent. At high temperatures, the curing reaction of the epoxy resin proceeds rapidly and the gelation time is shortened, so the mixing process is severely limited and difficult to handle. Furthermore, there is a problem that an epoxy resin mixture that is insoluble in an organic solvent is difficult to impregnate a fiber base material, and it is difficult to produce a prepreg and a laminate. When a soluble third component is added to compensate for the drawback, the melting point of the resin is lowered and the resin is easily dissolved in an organic solvent, but the cured product has a problem that the thermal conductivity is lowered.

  In addition, the cured product obtained from the epoxy resin having a mesogenic structure is not sufficiently advanced in crystallization, and exhibits high thermal conductivity, low thermal expansion, high heat resistance, low hygroscopicity, etc. that are manifested by improvement in crystallinity. The effect of was not enough. Patent Document 4 describes a sealant using a biphenyl ether type epoxy resin, but only teaches application to a sealant.

  The present invention provides a prepreg, a laminate or a printed wiring board to which an epoxy resin composition excellent in high thermal conductivity, low thermal expansion, high heat resistance and low hygroscopicity in addition to solubility in an organic solvent is applied. It is in.

  The present inventors have found an extremely specific phenomenon that an epoxy resin having a diphenyl ether structure crystallizes even in a three-dimensional crosslinked state after the curing reaction. The present invention can be achieved for the first time by applying this phenomenon to a prepreg, and exhibits high thermal conductivity, low thermal expansion, high heat resistance and low moisture absorption as a laminated board due to the development of crystallinity in a cured state. It is possible to manufacture a laminated board having excellent characteristics with secured properties.

（ここで、ｍは１であり、ｎは０以上の数を示す。）
That is, the present invention relates to a prepreg in which a sheet-like fiber base material is impregnated with an epoxy resin composition containing an epoxy resin and a curing agent to be in a semi-cured state. ), And a phenolic resin represented by the following general formula (3) and m = 1 is used as part or all of the curing agent .

(Here, m is 1 and n represents a number of 0 or more.)

（ここで、ｎは０以上の数の数を示す。）Examples of the epoxy resin represented by the general formula (1) include an epoxy resin represented by the following general formula (2).

(Here, n represents a number of 0 or more.)

As part or all of the curing agent, a phenolic resin or an aromatic diamine compound represented by the following general formula (3) can be used. And as phenolic resin shown by General formula (3), there exists phenolic resin shown by following General formula (4). In the general formulas (3) and (4), m represents a number from 1 to 3, and q represents a number of 0 or more.

  Moreover, this invention is a laminated board formed by heat-pressing the laminated material which has said prepreg as the whole layer of the prepreg layer, or one part layer. Furthermore, this invention is a printed wiring board provided with the insulating layer formed by heat-press-molding the layer of said prepreg. Here, in the laminated board or printed wiring board, the resin phase is crystallized, and preferably has a melting point of 120 ° C. to 280 ° C. In addition, the present invention is a prepreg cured product having a melting point of 120 ° C. to 280 ° C., in which a resin phase in a cured product obtained by heating and pressing the prepreg is crystallized.

  The laminate according to the present invention is formed by heating and press-molding a laminate material having the prepreg as a whole layer or a part of the prepreg layer and integrally laminating. Moreover, the printed wiring board according to the present invention includes an insulating layer formed by heating and pressing the above-described prepreg layer.

（但し、ｍは１〜３の整数を示す。）
で表されるビスフェノール化合物とエピクロルヒドリンを反応させることにより製造することができる。この反応は、通常のエポキシ化反応と同様に行うことができる。The epoxy resin represented by the general formula (1) is represented by the following general formula (5),

(However, m represents an integer of 1 to 3.)
It can manufacture by making the bisphenol compound represented by and epichlorohydrin react. This reaction can be performed in the same manner as a normal epoxidation reaction.

  For example, after the bisphenol compound of the general formula (5) is dissolved in excess epichlorohydrin, it is 50 to 150 ° C., preferably 60 to 100 in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. The method of making it react for 1 to 10 hours in the range of ° C is mentioned. In this case, the amount of the alkali metal hydroxide used is in the range of 0.8 to 1.2 mol, preferably 0.9 to 1.0 mol, relative to 1 mol of the hydroxyl group in the bisphenol compound. The epichlorohydrin is used in an excess amount relative to the hydroxyl group in the bisphenol compound, and is usually 1.2 to 15 mol with respect to 1 mol of the hydroxyl group in the bisphenol compound. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene, methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the target epoxy is removed by distilling off the solvent. A resin can be obtained.

  In the general formula (1), n is an integer of 0 or more, but the value of n can be easily adjusted by changing the molar ratio of epichlorohydrin to the bisphenol compound used in the epoxy resin synthesis reaction. Moreover, as an average value of n, the range of 0.1-10.0 is preferable. When larger than this, melting | fusing point and a viscosity will become high and handleability will fall.

  Further, in order to obtain a high molecular weight epoxy resin, a method in which an epoxy resin mainly composed of n in the general formula (1) and a bisphenol compound of the general formula (5) is reacted in advance is used. You can also.

  In the above general formula (5), m is 1, 2 or 3, preferably 1 or 2. Specifically, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 1,3-bis (4-hydroxyphenoxy) benzene, 1,3-bis (3-hydroxyphenoxy) Examples include benzene, 4,4′-bis (4-hydroxyphenoxy) diphenyl ether, 3,3′-bis (4-hydroxyphenoxy) diphenyl ether, and 3,3′-bis (3-hydroxyphenoxy) diphenyl ether. As a raw material of the epoxy resin, a mixture thereof may be used, but 4,4′-dihydroxydiphenyl ether or a bisphenol compound having a content of 50 wt% or more is preferable.

  Among the epoxy resins represented by the general formula (1), an epoxy resin represented by the general formula (2) is preferably exemplified. This epoxy resin is an epoxy resin in which m is 1 in the general formula (1), and n has the same meaning as that in the general formula (1).

  The epoxy resin used for the prepreg of the present invention contains a part or all of the epoxy resin represented by the general formula (1), preferably 50 wt% or more, more preferably 70 wt% or more. If it is less than this, the crystallinity at the time of making it into a cured product is lowered, and the effect of improving high thermal conductivity, low thermal expansion, high heat resistance and low hygroscopicity is small. In addition, the epoxy equivalent of the epoxy resin represented by the general formula (1) is usually in the range of 160 to 50,000, but is preferable from the viewpoint of imparting film properties and flexibility in applications such as laminates. Is in the range of 400 to 40,000. This epoxy equivalent preferably satisfies this condition even when two or more types of epoxy resins are used. In this case, the epoxy equivalent is calculated by the total weight (g) / epoxy group (mol).

The purity of the epoxy resin, in particular the amount of hydrolyzable chlorine, is better from the viewpoint of improving the reliability. Although it does not specifically limit, Preferably it is 1000 ppm or less, More preferably, it is 500 ppm or less. In addition, the hydrolyzable chlorine as used in the field of this invention means the value measured by the following method. That is, the potential difference the sample 0.5g were dissolved in dioxane 30 ml, 1N-KOH, after the added boiled under reflux for 30 minutes 10 ml, cooled to room temperature, 80% aqueous acetone 100ml was added, with 0.002 N-AgNO ₃ aqueous solution This is a value obtained by titration.

  In addition to the epoxy resin represented by the general formula (1), another epoxy resin having two or more epoxy groups in the molecule may be used in combination with the epoxy resin used in the present invention. Examples include bisphenol A, bisphenol F, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, fluorene bisphenol, 4,4'-biphenol, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-biphenol, hydroquinone, resorcin Catechol, t-butylcatechol, t-butylhydroquinone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1, 7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allylated or polyallylated products of the above-mentioned dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, Divalent phenols such as allylated phenol novolak, or phenol novolak, bisphenol A novolak, o-cresol novolak, m-cresol novolak, p-cresol novolak, xylenol novolak, poly-p-hydroxystyrene, tris- (4 -Hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, fluoroglycinol, pyrogallol, t-butyl pyrogallol, allylated pyrogallol, polyallylated pyrogallo 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, phenol aralkyl resin, naphthol aralkyl resin, dicyclopentadiene resin and other trivalent phenols, or tetrabromobisphenol A There are glycidyl ethers derived from halogenated bisphenols and the like. These epoxy resins can be used alone or in combination of two or more.

  As the curing agent used in the present invention, those generally known as epoxy resin curing agents can be used. Examples include dicyandiamide, imidazoles, amine curing agents, acid anhydride curing agents, phenol curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, block isocyanate curing agents, and the like. Is mentioned.

  Specific examples of the amine curing agent include aliphatic amines, polyether polyamines, alicyclic amines, aromatic amines and the like. Aliphatic amines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, diethylenetriamine, iminobispropylamine, bis ( Hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra (hydroxyethyl) ethylenediamine and the like. Examples of polyether polyamines include triethylene glycol diamine, tetraethylene glycol diamine, diethylene glycol bis (propylamine), polyoxypropylene diamine, and polyoxypropylene triamines. Cycloaliphatic amines include isophorone diamine, metacene diamine, N-aminoethylpiperazine, bis (4-amino-3-methyldicyclohexyl) methane, bis (aminomethyl) cyclohexane, 3,9-bis (3-amino). Propyl) 2,4,8,10-tetraoxaspiro (5,5) undecane, norbornenediamine and the like. Aromatic amines include tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4-diaminoanisole, 2, 4-toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-1,2-diphenylethane, 2,4-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone , M-aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethyl) phenol, triethanolamine, methylbenzylamine, α- (m-aminophenyl) ethylamine, α- (p-aminophenyl) Ethylamine, diaminodiethyldimethyldiphenylmethane, α, α'- Scan (4-aminophenyl)-p-diisopropylbenzene and the like.

  Specific examples of acid anhydride curing agents include dodecenyl succinic anhydride, polyadipic acid anhydride, polyazeline acid anhydride, polysebacic acid anhydride, poly (ethyloctadecanedioic acid) anhydride, poly (phenylhexadecanedioic acid) Anhydride, Methyltetrahydrophthalic anhydride, Methylhexahydrophthalic anhydride, Hexahydrophthalic anhydride, Methylhymic anhydride, Tetrahydrophthalic anhydride, Trialkyltetrahydrophthalic anhydride, Methylcyclohexene dicarboxylic anhydride, Methylcyclohexene tetracarboxylic Acid anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitic acid, anhydrous het acid, anhydrous nadic acid, anhydrous methyl nadic acid, 5- (2,5 -Geo Sotetrahydro-3-furanyl) -3-methyl-3-cyclohexane-1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride and the like.

  Specific examples of phenolic curing agents include bisphenol A, bisphenol F, phenol novolak, bisphenol A novolak, o-cresol novolak, m-cresol novolak, p-cresol novolak, xylenol novolak, poly-p-hydroxystyrene, resorcin, Catechol, t-butylcatechol, t-butylhydroquinone, fluoroglycinol, pyrogallol, t-butyl pyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2, , 8-dihydroxynaphthalene, allylated or polyallylated products of the above-mentioned dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, allylated pyrogallol and the like.

  These curing agents may be appropriately selected in consideration of the physical properties of the obtained prepreg or laminate, but are preferably phenolic curing agents or aromatic diamine compounds from the viewpoint of heat resistance, moisture resistance and electrical insulation, Particularly preferred is a phenolic resin represented by the general formula (3).

  The compounding amount of the curing agent with respect to the epoxy resin is usually determined so that the number of functional groups in the curing agent is in the range of 0.8 mol to 1.2 mol with respect to 1 mol of the epoxy group. The amount used when the phenolic resin represented by the general formula (3) is used is preferably 50% by weight or more, more preferably 70% by weight or more in the total curing agent component in the epoxy resin composition. By using this phenolic resin in the above amount or more, the degree of crystallinity when a cured epoxy resin is obtained increases, and effects such as high thermal conductivity, low thermal expansion, high heat resistance, and low hygroscopicity are excellent.

  The hydroxyl group equivalent of the phenolic resin represented by the general formula (3) is usually in the range of 100 to 40,000, but in applications such as laminates, it is preferably from the viewpoint of imparting film properties and flexibility. It is in the range of 200 to 20,000. This hydroxyl equivalent is preferably satisfied even when two or more types of epoxy resins are used. In this case, the hydroxyl equivalent is calculated by the total weight (g) / hydroxyl group (mol).

  Among the phenolic resins represented by the general formula (3), a phenolic resin represented by the general formula (4) is mentioned as a preferred phenolic resin. The phenolic resin represented by the general formula (4) is a phenolic resin in which m is 1 in the general formula (3), and q has the same meaning as that of the general formula (3). In addition, n can be calculated from the above hydroxyl group equivalent and may be calculated as an average value. In general formula (3), when q is 0, the phenolic resin is a bisphenol compound represented by general formula (5).

  In the general formula (3), when q is a number larger than 0, this phenolic resin can be produced, for example, by reacting the bisphenol compound of the general formula (5) with epichlorohydrin. In this case, 1 mol or less of epichlorohydrin is used with respect to 1 mol of hydroxyl group in the bisphenol compound, and the reaction is carried out in the presence of an alkali metal hydroxide.

  The bisphenol compound used as a raw material for the phenolic resin is preferably a bisphenol compound represented by the general formula (5). In the general formula (5), m is 1, 2 or 3, preferably 1 or 2. Specifically, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 1,3-bis (4-hydroxyphenoxy) benzene, 1,3-bis (3-hydroxyphenoxy) Examples include benzene, 4,4′-bis (4-hydroxyphenoxy) diphenyl ether, 3,3′-bis (4-hydroxyphenoxy) diphenyl ether, and 3,3′-bis (3-hydroxyphenoxy) diphenyl ether. As a raw material of the phenolic resin, a mixture thereof may be used, but preferably 4,4′-dihydroxydiphenyl ether or a bisphenol compound having a content of 50 wt% or more.

  Further, the phenolic resin represented by the general formula (3) is obtained by reacting the bisphenol compound of the general formula (5) with an epoxy resin mainly composed of n of the general formula (1) of 0. It can also be synthesized. In this case, the use ratio of both is that the epoxy group in the epoxy resin is 1 mol or less, preferably 0.1-0.9, more preferably 0.2-0. It is adjusted to be 6.

  Furthermore, the phenolic resin represented by the general formula (3) may be a single bisphenol compound in which q is 0 in the general formula (3), or a mixture thereof. As the bisphenol compound as such a phenolic resin, in general formula (3) or (5), m is 1, 2, or 3, but is preferably 1 or 2. Specifically, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 1,3-bis (4-hydroxyphenoxy) benzene, 1,3-bis (3-hydroxyphenoxy) Examples include benzene, 4,4′-bis (4-hydroxyphenoxy) diphenyl ether, 3,3′-bis (4-hydroxyphenoxy) diphenyl ether, and 3,3′-bis (3-hydroxyphenoxy) diphenyl ether.

  The epoxy resin composition used in the present invention may contain a conventionally known curing accelerator in addition to the epoxy resin and the curing agent. Examples include amines, imidazoles, organic phosphines, Lewis acids, etc., specifically 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, benzyldimethylamine, Tertiary amines such as ethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, Organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, tetra Tetra-substituted phosphonium tetra-substituted borate such as Chiruhosuhoniumu-tetrabutyl borate, 2-ethyl-4-methylimidazole · tetraphenyl port rate, and the like tetraphenyl boron salts such as N- methylmorpholine-tetraphenyl port rate. As addition amount, it is the range of 0.2-10 weight part normally with respect to 100 weight part of epoxy resins.

  Thermoplastic oligomers can be added to the epoxy resin composition used in the present invention from the viewpoint of improving fluidity during molding and improving adhesion to a lead frame and the like. Thermoplastic oligomers include C5 and C9 petroleum resins, styrene resins, indene resins, indene / styrene copolymer resins, indene / styrene / phenol copolymer resins, indene / coumarone copolymer resins, indene / benzothiophene. Examples thereof include copolymer resins. As addition amount, it is the range of 2-30 weight part normally with respect to 100 weight part of epoxy resins.

  Epoxy resin compositions used in the present invention include flame retardants such as brominated epoxies, mold release agents such as carnauba wax and ester wax, epoxy silane, amino silane, ureido silane, vinyl silane, alkyl silane, organic titanate, aluminum alcoholate Coupling agents such as carbon black, colorants such as carbon black, flame retardant aids such as antimony trioxide, low stress agents such as silicone oil, lubricants such as higher fatty acids and higher fatty acid metal salts, and the like can be used.

  Furthermore, in order to improve the thermal conductivity of the cured epoxy resin, an appropriate amount of an inorganic filler can be added to the epoxy resin composition. Examples of the inorganic filler include metals, metal oxides, metal nitrides, metal carbides, metal hydroxides, and carbon materials. Silver, copper, gold, platinum, zircon, etc. as metal, silica, aluminum oxide, magnesium oxide, titanium oxide, tungsten trioxide, etc. as metal oxide, boron nitride, aluminum nitride, silicon nitride, etc. as metal nitride Silicon carbide as metal carbide, aluminum hydroxide and magnesium hydroxide as metal hydroxide, carbon fiber, graphitized carbon fiber, natural graphite, artificial graphite, spherical graphite particles, mesocarbon microbeads as carbon material , Whisker-like carbon, microcoiled carbon, nanocoiled carbon, carbon nanotube, carbon nanohorn and the like. As the shape of the inorganic filler, a crushed shape, a spherical shape, a whisker shape, or a fiber shape can be applied. These inorganic fillers may be blended singly or in combination of two or more. Ordinary coupling agent treatment may be applied to the inorganic filler for the purpose of improving the wettability between the inorganic filler and the epoxy resin, reinforcing the interface of the inorganic filler, and improving the dispersibility.

  The epoxy resin composition used in the present invention is preferably produced by impregnating a sheet-like fiber base material and drying it as a varnish using a solvent. Solvents in this case include aromatic solvents such as benzene, toluene, xylene and chlorobenzene, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, aliphatic hydrocarbon solvents such as hexane, heptane and methylcyclohexane, ethanol Alcohol solvents such as isopropanol, butanol, ethylene glycol, ether solvents such as diethyl ether, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, etc. Polar solvents can be used.

  The prepreg according to the present invention is obtained by impregnating the above epoxy resin composition into a sheet-like fiber base material (woven fabric or non-woven fabric) made of glass fiber or organic fiber, followed by drying by heating, so that the epoxy resin is in a semi-cured state. It is what. Alternatively, the epoxy resin composition obtained by heating and partially curing the above epoxy resin composition solution may be impregnated into a sheet-like fiber base material and dried by heating.

  The laminated board of the present invention is formed by heat-pressing a laminated material having all or part of the prepreg layer. And a laminated material may consist only of a prepreg layer, or may have layers other than a prepreg layer. When the prepreg layer is composed of a plurality of layers, it has at least one prepreg of the present invention. Advantageously, it is 50% or more, preferably 70% or more of the total prepreg layer thickness in the laminate.

  Another type of substrate can be laminated on one side, both sides, or the middle of the prepreg layer. As the substrate to be laminated, there are sheet-like and film-like materials, such as copper foil, aluminum foil, stainless steel foil, etc., polyethylene, polypropylene, polystyrene, polyacrylate, polymethacrylate, polyethylene terephthalate, polybutylene terephthalate, Examples of the polymer base material include polyethylene naphthalate, liquid crystal polymer, polyamide, polyimide, and Teflon (registered trademark).

  The printed wiring board of the present invention is provided with an insulating layer formed by heat-pressing the prepreg layer, and is a single-sided printed wiring board, a double-sided printed wiring board, and further a multilayer printed circuit having a printed wiring in the inner layer. It is a wiring board.

  When the prepreg of the present invention is heat-press molded, a prepreg cured product is obtained. The prepreg cured product preferably has a crystallized resin phase. Moreover, as for the laminated board or printed wiring board of this invention, it is desirable for the resin phase to crystallize. The growth of the crystal phase can be visually confirmed because the resin phase becomes cloudy and eventually becomes opaque, but the degree of crystal phase growth can be estimated from the endothermic amount by differential thermal analysis. A preferable endothermic amount is 10 J / g or more per unit weight of the resin component (corresponding to the total of the epoxy resin, the curing agent and the curing accelerator) excluding the filler, the sheet-like fiber base material, the metal foil and the like. More preferably, it is 30 J / g or more, and particularly preferably 60 J / g or more. When smaller than this, the improvement effect of thermal conductivity, low thermal expansibility, high heat resistance, and low hygroscopicity as a cured epoxy resin is small. Furthermore, those having a large endotherm, that is, those having a high degree of crystallinity, can maintain strength at high temperatures by maintaining crystallinity even if the glass transition point is low, and are practically heat resistant. The heat distortion temperature can be kept high. The melting point of the crystallized resin phase is in the range of 120 ° C. to 280 ° C., preferably in the range of 150 ° C. to 250 ° C. In addition, the endothermic amount here refers to the endothermic amount obtained by measuring with a differential thermal analyzer under the condition of a temperature rising rate of 5 ° C./min under a nitrogen stream using a sample accurately weighed about 10 mg. The melting point is the endothermic peak temperature of differential thermal analysis.

  The degree of crystallization of the resin can be adjusted by controlling the curing conditions of the prepreg. The optimum curing conditions largely depend on the blending conditions of the epoxy resin composition, but usually the molding temperature is 80 ° C. to 250 ° C., and the molding time is 1 minute to 20 hours. The molding pressure is preferably in the range of 0.2 MPa to 20 MPa, but may be a vacuum press. In order to increase the crystallinity of the cured epoxy resin, it is desirable to cure at a low temperature for a long time. A preferred curing temperature is in the range of 120 ° C to 200 ° C, more preferably 140 ° C to 180 ° C. The preferable curing time is 10 minutes to 6 hours, more preferably 30 minutes to 3 hours. Further, after molding, the crystallinity can be further increased by post-cure. Usually, the post-cure temperature is 130 ° C. to 250 ° C., and the time is in the range of 1 hour to 24 hours, but preferably 1 hour at a temperature 5 ° C. to 50 ° C. lower than the endothermic peak temperature in differential thermal analysis. It is desirable to perform post-cure over 24 hours from the beginning.

Examples of the present invention will be described below, and the present invention will be described in detail.

Synthesis example 1
1010 g of 4,4′-dihydroxydiphenyl ether was dissolved in 6475 g of epichlorohydrin, and 808 g of a 48% aqueous sodium hydroxide solution was added dropwise over 4 hours at about 120 mmHg and 60 ° C. over 4 hours. The distilled epichlorohydrin was returned to the system by boiling, and the reaction was continued for another hour after the completion of the dropping, and then the epichlorohydrin was distilled off under reduced pressure, dissolved in 3660 g of methyl isobutyl ketone, and filtered. Thereafter, 119.4 g of a 20% aqueous sodium hydroxide solution was added, and the mixture was reacted for 2 hours at 80 ° C. After the reaction, filtration and washing were performed, and then methyl isobutyl ketone as a solvent was distilled off under reduced pressure. To obtain 1440 g of a light yellow crystalline epoxy resin (epoxy resin A). The epoxy equivalent of the obtained epoxy resin was 163 g / eq, the hydrolyzable chlorine was 280 ppm, the melting point was 78 to 84 ° C., and the viscosity at 150 ° C. was 0.0062 Pa · s. The sample was prepared by dissolving 0.5 g of the sample in 30 ml of dioxane, adding 10 ml of 1N-KOH, boiling and refluxing for 30 minutes, cooling to room temperature, and further adding 100 ml of 80% acetone water to 0.002 N-AgNO _3. The value is obtained by performing potentiometric titration with an aqueous solution, and the melting point is a value obtained by a capillary method at a heating rate of 2 ° C./min.

Synthesis example 2
Into a 1 L, 4-neck separable flask equipped with a stirrer, thermometer, cooling tube, and nitrogen introduction tube were charged 489 g of the epoxy resin synthesized in Synthesis Example 1 and 75.8 g of 4,4′-dihydroxydiphenyl ether, and under a nitrogen stream, After stirring and mixing at 150 ° C. with stirring, 0.226 g of triphenylphosphine was added and the reaction was performed for 2 hours. After the reaction, the obtained epoxy resin (epoxy resin B) was allowed to cool to room temperature, thereby showing crystallinity and solidifying. The epoxy equivalent of the obtained epoxy resin is 261 g / eq. The melting point was 100 to 122 ° C., and the viscosity at 150 ° C. was 0.037 Pa · s. Moreover, each component ratio in General formula (1) calculated | required from GPC measurement of the obtained resin is 45.8% for n = 0, 28.0% for n = 2, and 12.3% for n = 4. N ≧ 6 was 13.9%. Here, the viscosity was measured with Rheomatt 115 manufactured by Contrabass. In addition, GPC measurement was performed by using an apparatus; HLC-82A (manufactured by Tosoh Corp.), column; TSK-GEL2000 × 3 and TSK-GEL4000 × 1 (both manufactured by Tosoh Corp.), solvent; 1 ml / min, temperature; 38 ° C., detector; RI conditions were followed.

Example 1
Into a 1 L, 4-neck separable flask equipped with a stirrer, thermometer, cooling pipe, and nitrogen introduction pipe, 185.2 g of epoxy resin A obtained in Synthesis Example 1 as an epoxy resin component, and 4,4 ′ as a curing agent component -141.8 g of dihydroxydiphenyl ether (curing agent A) and 0.18 g of 2-ethyl-4-methylimidazole as a curing accelerator were dissolved in 246 g of cyclohexanone and reacted at 120 ° C for 0.5 hour to give an epoxy. A resin composition varnish was prepared. The viscosity at 25 ° C. in the E-type viscometer was 0.42 Pa · s. From the GPC measurement, 25.7% of the epoxy resin obtained in Reference Example 1 remained, and 24.2% of 4,4′-dihydroxydiphenyl ether remained.

  The epoxy resin composition was impregnated into a glass fiber woven fabric having a thickness of 0.07 mm and dried by heating at 150 ° C. for 8 minutes to obtain a prepreg. Four prepregs are stacked, devolatilized at a temperature of 130 ° C. for 15 minutes by a vacuum press machine, and then integrated by heating and pressing for 90 minutes under the conditions of a temperature of 175 ° C. and a pressure of 2 MPa. I got a plate. A plate-like sample of 50 mm × 120 mm was cut out from this laminated plate and subjected to various physical property measurements.

Example 2
Except that the epoxy resin component was 216.3 g of the epoxy resin B obtained in Synthesis Example 2, and the curing agent component was 83.7 g of 4,4′-dihydroxydiphenyl ether (curing agent A), the same as in Example 1. An epoxy resin composition varnish was prepared. The viscosity at 25 ° C. was 0.56 Pa · s. A laminate was obtained from this epoxy resin composition in the same manner as in Example 1 and subjected to various physical property measurements.

Example 3
The epoxy resin component was 189.5 g of the epoxy resin A obtained in Synthesis Example 1, the curing agent component was 99.4 g of 4,4′-dihydroxydiphenyl ether (curing agent A) and 4,4′-diaminodiphenyl sulfone (curing agent). B) An epoxy resin composition varnish was prepared in the same manner as in Example 1 except that 11.0 g was used. The viscosity at 25 ° C. was 0.61 Pa · s. A laminate was obtained from this epoxy resin composition in the same manner as in Example 1 and subjected to various physical property measurements.

Example 4 (Reference Example)
The same procedure as in Example 1 was conducted except that the epoxy resin component was 242.3 g of the epoxy resin B obtained in Synthesis Example 2 and the curing agent component was 47.6 g of 4,4′-diaminodiphenylsulfone (curing agent B). Thus, an epoxy resin composition varnish was prepared. The viscosity at 25 ° C. was 0.78 Pa · s. A laminate was obtained from this epoxy resin composition in the same manner as in Example 1 and subjected to various physical property measurements.

Example 5 (Reference Example)
The epoxy resin component was 183.8 g of the epoxy resin A obtained in Synthesis Example 1, and the curing agent component was PSM-4261 (curing agent C: manufactured by Gunei Chemical Co., phenol novolak resin; OH equivalent 103 g / eq., Softening point 80 The epoxy resin composition varnish was prepared in the same manner as in Example 1 except that 116.1 g. The viscosity at 25 ° C. was 0.47 Pa · s. A laminate was obtained from this epoxy resin composition in the same manner as in Example 1 and subjected to various physical property measurements.

Comparative Example 1
As an epoxy resin component, YD-128 (epoxy resin C: manufactured by Tohto Kasei, bisphenol A type epoxy resin, epoxy equivalent 186 g / eq.) 193.0 g, as a curing agent component, PSM-4261 (curing agent C: manufactured by Gunei Chemical Co., Ltd.) , Phenol novolac resin; OH equivalent 103 g / eq., Softening point 80 ° C.) 106.9 g was used in the same manner as in Example 1 to prepare an epoxy resin composition varnish. The viscosity at 25 ° C. was 0.43 Pa · s. A laminate was obtained from this epoxy resin composition in the same manner as in Example 1 and subjected to various physical property measurements.

Comparative Example 2
As an epoxy resin component, YD-128 (epoxy resin C: manufactured by Tohto Kasei Co., Ltd., bisphenol A type epoxy resin, epoxy equivalent 186 g / eq.) 225.0 g, 4,4′-diaminodiphenyl sulfone (curing agent B) as a curing agent component ) Using 75.0 g, the reaction was carried out in the same manner as in Example 1 to prepare an epoxy resin composition varnish. The viscosity at 25 ° C. was 0.61 Pa · s. A laminate was obtained from this epoxy resin composition in the same manner as in Example 1 and subjected to various physical property measurements.

Comparative Example 3
As an epoxy resin component, YX-4000H (epoxy resin C: manufactured by Japan Epoxy Resin, biphenyl type epoxy resin; epoxy equivalent 195 g / eq.) 196.3 g, as a curing agent component, PSM-4261 (curing agent C: manufactured by Gunei Chemical Co., Ltd.) , Phenol novolac resin; OH equivalent 103 g / eq., Softening point 80 ° C.) 103.7 g was used in the same manner as in Example 1 to prepare an epoxy resin composition varnish. The viscosity at 25 ° C. in the E-type viscometer was 0.45 Pa · s. A laminate was obtained from this epoxy resin composition in the same manner as in Example 1 and subjected to various physical property measurements.

  The measurement results are summarized in Table 1. In Table 1, Tg is the glass transition point, CTE is the thermal expansion coefficient, HDT is the heat distortion temperature, and m.p. is the melting point. In the appearance, X is transparent, Δ is slightly turbid, and ◯ is completely opaque.

Industrial applicability

  According to the present invention, an epoxy resin having a diphenyl ether structure is used as an epoxy resin component, but the diphenyl ether structure is different from an epoxy resin having a mesogenic group which is a rigid main chain conventionally known, and has a solvent solubility. The prepreg has excellent characteristics and excellent thermal conductivity. The printed wiring board of the present invention has a good thermal conductivity of the insulating layer and excellent heat dissipation. Therefore, the printed wiring board for automobile equipment, the power supply unit board for home appliances, personal computers, servers, etc. It is suitably used for plates.

Claims (9)

In a prepreg in which a sheet-like fiber base material is impregnated with an epoxy resin composition containing an epoxy resin and a curing agent to form a semi-cured state, an epoxy resin represented by the following general formula (1) is used as a part or all of the epoxy resin. use have as part or all of the curing agent, prepreg characterized by using a phenolic resin represented by the following general formula (3).

Here, m is 1 and n is a number of 0 or more.

Here, m is 1 and q represents a number of 0 or more. The prepreg according to claim 1, wherein the epoxy resin represented by the general formula (1) is an epoxy resin represented by the following general formula (2).

Here, n represents a number of 0 or more. The prepreg according to claim 1 or 2, wherein the phenolic resin represented by the general formula (3) is a phenolic resin represented by the following general formula (4) .

Here, q represents a number of 0 or more. The epoxy resin represented by the general formula (1) is used by 70 wt% or more of the total epoxy resin, and the phenolic resin represented by the general formula (3) is used by 50 wt% or more of the total curing agent. The prepreg according to any one of the above. The prepreg according to any one of claims 1 to 4, wherein an aromatic diamine compound is used as a part of the curing agent.   A laminate comprising a laminate material having the prepreg according to any one of claims 1 to 5 as a whole layer or a part of a prepreg layer, which is formed by heating and pressing.   A prepreg obtained by crystallizing a resin phase in a cured product obtained by heating and pressing the prepreg according to claim 1 and having a melting point of 120 ° C to 280 ° C. Cured product.   A printed wiring board comprising an insulating layer obtained by heating and pressing the prepreg layer according to claim 1.   The printed wiring board according to claim 8, wherein the resin phase in the insulating layer is crystallized and has a melting point of 120 ° C. to 280 ° C.