JP2010126626A - Prepreg and layered product using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prepreg giving a layered product being excellent in dielectric characteristic at a high frequency area and being excellent in flame retardancy, hydrolysis-resistance and acid-resistance in a non-halogen system, and to provide a layered product obtained using such a prepreg. <P>SOLUTION: In the prepreg, a reinforced fiber is impregnated with a curable resin composition containing a conjugated diene-based polymer, a curing agent, a filler and a phosphinate. The layered product is obtained by superposing the prepreg and the prepreg or other materials and curing them. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a prepreg suitable for a multilayer wiring board including an electronic circuit wiring board, and a laminate using such a prepreg.

  A circuit board is generally composed of a dielectric layer and a conductor layer. In recent years, with the advent of advanced information technology, information transmission has begun to move toward higher speeds and higher frequencies, and microwave communication and millimeter wave communication are becoming reality. The dielectric layers of circuit boards in these high frequency eras must reduce noise and transmission loss at high frequencies to the utmost. Therefore, as a material for forming such a dielectric layer, a dielectric material having a high Q value is used. Selection has become an important issue.

  As a dielectric material for such a circuit board, an epoxy resin having a Q value of usually about 10 to 30 has been used in a conventional low frequency (KHz to MHz range) circuit board. However, in a high-frequency circuit board in the GHz range, if the Q value is low, the performance and reliability of the circuit board are not sufficient, and the Q value of the epoxy resin conventionally used is several times to 10 times or more. Is required to have a Q value of 100 or more. In addition, a material excellent in flame retardancy, particularly non-halogen flame retardancy without using a halogen flame retardant (hereinafter referred to as non-halogen flame retardancy) is demanded for use in consumer applications.

  For example, Patent Document 1 discloses an insulation composed of a flame-retardant thermosetting resin composition containing polybutadiene or polyisoprene resin, a crosslinking agent, a particulate fluoropolymer, and 20 to 50% by weight of magnesium hydroxide based on the total amount. An electronic circuit member comprising a layer and a conductor layer is disclosed.

  On the other hand, Patent Document 2 discloses that a combination of a phosphinate and a silica, aluminum phosphate, dihydrotalcite, zinc borate, zinc oxide or the like is useful as a flame retardant for a thermoplastic polymer. It is disclosed that the flame retardant effect differs depending on differences in thermoplastic polymers such as ABS, nylon-6, polybutyrin terephthalate and the like.

  Patent Document 3 discloses that phosphinate alone is not effective in making flame retardant resins such as unsaturated polyesters and epoxy resins, but it can be combined with zinc borate, zinc stannate, and zinc oxide. It is disclosed that flame retardancy is achieved.

  Further, Patent Document 4 discloses phosphinate and reactive organic compounds as flame retardants such as thermoplastic resins such as polyamide resins and polyolefin resins, and thermosetting resins such as epoxy resins, phenol resins and unsaturated polyester resins. Combining phosphate compounds is disclosed.

US Patent Publication No. 7,022,404 JP 2000-219772 A Japanese Patent Application Laid-Open No. 2004-115797 JP 2006-328124 A

However, when the present inventor examined, the electronic circuit member described in Patent Document 1 has a problem that flame retardancy is not always sufficient. Moreover, in the flame-retardant composition disclosed in Patent Documents 2 to 4, when formed into a molded body, high-frequency dielectric properties, hydrolysis resistance, acid resistance, and non-halogen flame resistance are highly balanced. The problem of being unable to do so was recognized.
An object of the present invention is to provide a prepreg that provides a laminate having excellent dielectric properties in a high-frequency region, and having excellent non-halogen flame resistance (non-halogen flame resistance), hydrolysis resistance, and acid resistance, and the like. It is providing the laminated body obtained using a prepreg.

  As a result of intensive studies in view of the above problems, the present inventor, in a prepreg obtained by impregnating a reinforcing fiber with a resin composition containing a conjugated diene polymer, a curing agent and a filler, and a metal / resin laminate obtained using the prepreg A prepreg which provides a laminate excellent in non-halogen flame resistance, hydrolysis resistance and acid resistance while maintaining a high Q value by blending a phosphinic acid salt as a flame retardant in the resin composition, and It has been found that the laminate can be obtained, and the present invention has been completed based on this finding.

That is, according to the present invention,
[1] A prepreg obtained by impregnating a reinforcing fiber with a curable resin composition containing a conjugated diene polymer, a curing agent, a filler, and a phosphinate, and [2] the prepreg according to [1], and the prepreg Or a laminate obtained by laminating and curing with other materials,
Is provided.

  According to the present invention, a prepreg capable of giving a laminate having a high Q value and excellent non-halogen flame retardancy, hydrolysis resistance and acid resistance, and a laminate obtained using such a prepreg are provided. Can be provided. Such a laminate of the present invention has a high Q value and is excellent in non-halogen flame retardancy, hydrolysis resistance and acid resistance, and is therefore suitable for high frequency circuit boards such as microwaves or millimeter waves for communication equipment applications. Can be used.

The prepreg of the present invention is obtained by impregnating reinforcing fibers with a curable resin composition containing a conjugated diene polymer, a curing agent, a filler, and a phosphinate.
First, each component which comprises the curable resin composition used by this invention is demonstrated.

(Conjugated diene polymer)
The conjugated diene polymer used in the present invention is not particularly limited as long as it is a polymer containing at least a conjugated diene monomer unit, but at least one selected from the group consisting of a conjugated diene homopolymer and a conjugated diene copolymer. Species are preferably used.

  The conjugated diene homopolymer may be a polymer obtained by polymerizing only a conjugated diene monomer, and those generally used industrially can be used without any particular limitation. Examples of the conjugated diene monomer that forms the conjugated diene homopolymer include butadiene, isoprene, chloroprene, cyanobutadiene, and pentadiene. Among these, butadiene and isoprene are preferable, and butadiene is more preferable. These conjugated diene monomers can be used alone or in combination of two or more.

  Specific examples of the conjugated diene homopolymer include polybutadiene, polyisoprene, polychloroprene, polycyanobutadiene, and polypentadiene. Among these, polybutadiene and polyisoprene are preferable, and polybutadiene is more preferable. The polymerization mode of the conjugated diene homopolymer is not particularly limited, and may be appropriately selected depending on the purpose of use. Moreover, it does not specifically limit as a manufacturing method of a conjugated diene homopolymer, What is necessary is just to manufacture by a well-known method.

  The conjugated diene copolymer is not particularly limited as long as it is a copolymer containing at least a conjugated diene monomer unit. By using the conjugated diene copolymer, it is possible to improve the impregnation property of the curable resin composition into the reinforcing fiber when making a prepreg.

  As the conjugated diene monomer forming the conjugated diene monomer unit of the conjugated diene copolymer, the same conjugated diene homopolymer as described above can be used.

  In addition, as a monomer that forms a monomer unit other than the conjugated diene monomer unit of the conjugated diene copolymer, there is no particular limitation as long as it is a monomer copolymerizable with the conjugated diene monomer. However, examples include cyano group-containing vinyl monomers, amino group-containing vinyl monomers, pyridyl group-containing vinyl monomers, alkoxyl group-containing vinyl monomers, and aromatic vinyl monomers. Among these, cyano group-containing vinyl monomers and aromatic vinyl monomers are preferable, and aromatic vinyl monomers are more preferable. These monomers copolymerizable with the conjugated diene monomer can be used alone or in combination of two or more.

  Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t. -Butyl styrene, 5-t-butyl-2-methyl styrene, N, N-dimethylaminoethyl styrene, N, N-diethylaminoethyl styrene and the like. Of these, styrene and α-methylstyrene are particularly preferable. These aromatic vinyl monomers can be used alone or in combination of two or more.

  The ratio of the conjugated diene monomer and the monomer copolymerizable with the conjugated diene monomer in the conjugated diene copolymer may be appropriately selected according to the purpose of use. The weight ratio of “body unit / unit of copolymerizable monomer” is usually in the range of 5/95 to 95/5, preferably 10/90 to 90/10, more preferably 20/80 to 80/20. is there. By setting the ratio in the above range, the operability of the prepreg can be improved, and the properties such as the operability, mechanical strength and toughness of the obtained laminate can be highly balanced.

  In addition, as the conjugated diene copolymer, either a random copolymer or a block copolymer can be used, but a block copolymer is preferable. The bonding mode of the conjugated diene block copolymer is appropriately selected according to the purpose of use, such as a diblock copolymer, triblock copolymer, tetrablock copolymer, and pentablock copolymer. Among these, a triblock copolymer is preferable because it can highly balance the laminate properties and mechanical strength of the resulting laminate. Specific examples of such a triblock copolymer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, α-styrene-butadiene-α-styrene block copolymer, and the like. It is done. Among these, a styrene-butadiene-styrene block copolymer is preferable. In addition, it does not specifically limit as a manufacturing method of a conjugated diene type copolymer, What is necessary is just to manufacture by a well-known method.

  In the present invention, as the conjugated diene polymer, the above conjugated diene homopolymer and conjugated diene copolymer can be used alone or in combination of two or more. It is preferable to use in combination with a diene copolymer. By using these in combination, the laminate property of the prepreg can be improved, and the properties such as mechanical strength and hydrolysis resistance of the resulting laminate can be highly balanced.

  The amount of 1,2-vinyl bond in the conjugated diene part of the conjugated diene polymer used in the present invention is not particularly limited and may be appropriately selected depending on the intended use, but is usually 5 mol% or more, preferably 40 mol%. As mentioned above, More preferably, it is 60 mol% or more, More preferably, it is 80 mol% or more. By setting the 1,2-vinyl bond amount of the conjugated diene part in the above range, the mechanical strength and heat resistance of the obtained laminate can be improved to a high degree.

  The molecular weight of the conjugated diene polymer used in the present invention is not particularly limited and may be appropriately selected depending on the purpose of use, but it is a weight average molecular weight measured by gel permeation chromatography (polystyrene conversion, toluene eluent). The range is usually 500 to 5,000,000, preferably 1,000 to 1,000,000.

  Moreover, the molecular weight of the conjugated diene homopolymer when using a conjugated diene homopolymer and a conjugated diene copolymer in combination as a conjugated diene polymer is measured by gel permeation chromatography (polystyrene conversion, toluene eluent). The weight average molecular weight is usually 500 to 500,000, preferably 1,000 to 10,000, and more preferably 1,000 to 5,000. On the other hand, the molecular weight of the conjugated diene copolymer is a weight average molecular weight measured by gel permeation chromatography (polystyrene conversion, toluene eluent) and is usually 1,000 to 1,000,000, preferably 5,000. It is -500,000, More preferably, it is the range of 10,000-300,000. When using a combination of a conjugated diene homopolymer and a conjugated diene copolymer, by making these molecular weights within the above range, the relationship between the laminate property and mechanical strength of the resulting laminate is highly balanced. Can do.

  Furthermore, when the conjugated diene homopolymer and the conjugated diene copolymer are used in combination, the ratio of these polymers is not particularly limited, and may be appropriately selected according to the purpose of use. The weight ratio of the “conjugated diene copolymer” is usually in the range of 5/95 to 95/5, preferably 15/85 to 90/10, and more preferably 50/50 to 90/10. By setting this ratio within the above range, the laminate property of the prepreg can be improved, and the properties such as mechanical strength, toughness and hydrolysis resistance of the resulting laminate can be highly balanced.

(Curing agent)
The curing agent used in the present invention is not particularly limited as long as it can induce a crosslinking reaction in the conjugated diene polymer described above, and a radical generator is usually used. Examples of the radical generator include organic peroxides, diazo compounds, and nonpolar radical generators. Among these, organic peroxides and nonpolar radical generators are preferable, and nonpolar radical generators are more preferable because the Q value of the resin layer of the obtained laminate can be highly enhanced.

  Examples of the organic peroxide include hydroperoxides such as t-butyl hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide; dicumyl peroxide, t-butylcumyl peroxide, α, α′-bis (t- Butylperoxy-m-isopropyl) benzene, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) -3-hexyne, 2,5-dimethyl-2,5-di ( dialkyl peroxides such as t-butylperoxy) hexane; diacyl peroxides such as dipropionyl peroxide and benzoyl peroxide; 2,2-di (t-butylperoxy) butane, 1,1-di (t-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) -2-methyl Peroxyketals such as chlorocyclohexane and 1,1-di (t-butylperoxy) cyclohexane; peroxyesters such as t-butylperoxyacetate and t-butylperoxybenzoate; t-butylperoxyisopropylcarbonate, di (isopropylperoxy) ) Peroxycarbonates such as dicarbonate; alkylsilyl peroxides such as t-butyltrimethylsilyl peroxide; 3,3,5,7,7-pentamethyl-1,2,4-trioxepane, 3,6,9-triethyl-3 , 6,9-trimethyl-1,4,7-triperoxonane, cyclic peroxides such as 3,6-diethyl-3,6-dimethyl-1,2,4,5-tetroxane; . Among these, dialkyl peroxides, peroxyketals, and cyclic peroxides are preferable.

  Examples of the diazo compound include 4,4'-bisazidobenzal (4-methyl) cyclohexanone and 2,6-bis (4'-azidobenzal) cyclohexanone.

  Examples of the nonpolar radical generator include 2,3-dimethyl-2,3-diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, 1,1,2-triphenylethane, 1,1, Examples thereof include 1-triphenyl-2-phenylethane.

  When a radical generator is used as the curing agent, the half-life temperature for 1 minute varies depending on the type of radical generator used and the use conditions, but is usually 50 to 350 ° C, preferably 100 to 250 ° C, more preferably 150. It is in the range of ~ 230 ° C.

  These curing agents can be used alone or in combination of two or more. The amount of the curing agent used is usually 0.01 to 10 parts by weight, preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the conjugated diene polymer. is there.

(filler)
The filler used in the present invention is not particularly limited as long as it is generally used industrially, and either an inorganic filler or an organic filler can be used, but an inorganic filler is preferable. Used.

  Examples of the inorganic filler include metal particles such as iron, copper, nickel, gold, silver, aluminum, lead, and tungsten; carbon particles such as carbon black, graphite, activated carbon, and carbon balloon; silica, silica balloon, alumina, Inorganic oxide particles such as titanium oxide, iron oxide, zinc oxide, magnesium oxide, tin oxide, beryllium oxide, barium ferrite, strontium ferrite; inorganic carbonate particles such as calcium carbonate, magnesium carbonate, sodium hydrogen carbonate; calcium sulfate, etc. Inorganic sulfate particles; inorganic silicate particles such as talc, clay, mica, kaolin, fly ash, montmorillonite, calcium silicate, glass, glass balloon; titanate particles such as calcium titanate and lead zirconate titanate; Aluminum nitride, silicon carbide particles Whiskers; and the like. Among these, metal particles, inorganic oxide particles, inorganic hydroxide particles, inorganic silicate particles, and titanate particles from the viewpoint that the dielectric loss tangent and laminate property of the obtained laminate can be highly balanced. Are preferred, and inorganic oxide particles and titanates are more preferred.

  Examples of the organic filler include compound particles such as wood powder, starch, organic pigments, polystyrene, nylon, polyolefins such as polyethylene and polypropylene, vinyl chloride, various elastomers, and waste plastics.

  These fillers can be used alone or in combination of two or more. The blending amount of the filler is usually 1 to 1,000 parts by weight, preferably 50 to 750 parts by weight, and more preferably 10 to 500 parts by weight with respect to 100 parts by weight of the conjugated diene polymer.

(Phosphinate)
The phosphinic acid salt used in the present invention acts as a flame retardant. Such phosphinic acid salts can be used without particular limitation as long as they are industrially used. For example, JP-A Nos. 2000-219772, 2004-115797, and 2006-2006. Those described in Japanese Patent No. 328124 can be used.

  Examples of the phosphinic acid salt include alkali metal salts of phosphinic acid, and calcium phosphinic acid salt, zinc phosphinic acid salt, aluminum phosphinic acid salt and the like are particularly preferably used. Examples of the phosphinic acid salt include monophosphinic acid salts; oligophosphinic acid salts such as diphosphinic acid; and phosphinic acid polymer salts; depending on the number of phosphinic acid units. Acid salts and oligophosphinic acid salts are preferred, and monophosphinic acid salts are more preferred.

（上記式（１）及び式（２）中、Ｒ^１及びＲ^２は、それぞれ独立して、アルキル基またはアリール基を、Ｒ^３は、アルキレン基、アリーレン基、アルキルアリーレン基またはアリールアルキレン基を、Ｍは金属原子を、ｍ及びｎはそれぞれ１〜４の整数を、ｘは１〜４の整数を、それぞれ示す。） Specific examples of such phosphinic acid include compounds represented by the following general formula (1) and general formula (2).

(In the above formulas (1) and (2), R ¹ and R ² each independently represents an alkyl group or an aryl group, and R ³ represents an alkylene group, an arylene group, an alkylarylene group or an arylalkylene group. M represents a metal atom, m and n each represents an integer of 1 to 4, and x represents an integer of 1 to 4.

Preferable examples of R ¹ and R ^{2 in} the above formulas (1) and (2) include an alkyl group having 1 to 6 carbon atoms and an aryl group having 3 to 12 carbon atoms. Preferred examples of R ³ include an alkylene group having 1 to 10 carbon atoms; an arylene group, an alkylarylene group, or an arylalkylene group having 6 to 12 carbon atoms; Preferable examples of M include a calcium atom, an aluminum atom and a zinc atom. m is 2 when M is a calcium atom or a zinc atom, and 3 when M is an aluminum atom. Specific examples of the phosphinic acid moiety include dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, methandi (methylphosphinic acid), benzene-1,4- (dimethylphosphinic acid), methyl Examples thereof include phenylphosphinic acid and diphenylphosphinic acid.

  Examples of the compound represented by the general formula (1) include aluminum diethylphosphinate, zinc diethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate and the like. Examples of the compound represented by the general formula (2) include aluminum diethyldiphosphinate, zinc diethyldiphosphinate, aluminum dimethyldiphosphinate, zinc dimethyldiphosphinate and the like.

  These phosphinic acid salts can be used alone or in combination of two or more. The blending amount of the phosphinic acid salt is not particularly limited and may be appropriately selected depending on the purpose of use, but is preferably 10 to 1,000 parts by weight, more preferably 50 parts per 100 parts by weight of the conjugated diene polymer. It is -500 weight part, More preferably, it is the range of 100-300 weight part.

  In the present invention, as the flame retardant, in addition to the phosphinic acid salt, other flame retardants may be blended as desired. Other flame retardants include, for example, metal hydroxide flame retardants such as aluminum hydroxide and magnesium hydroxide; metal oxide flame retardants such as magnesium oxide and aluminum oxide; red phosphorus, triphenyl phosphate, tricresyl Phosphoric flame retardants other than phosphinates such as phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, resorcinol bis (diphenyl) phosphate, bisphenol A bis (diphenyl) phosphate, bisphenol A bis (dicresyl) phosphate; melamine derivatives Flame retardants containing both phosphorus and nitrogen, such as ammonium polyphosphate, melamine phosphate, melamine phosphate, melamine polyphosphate, melam polyphosphate, guanidine phosphate, phosphazenes, etc. ; And the like. These other flame retardants can be used alone or in combination of two or more. The blending amount may be appropriately selected within a range that does not impair the effects of the present invention, but the ratio of the phosphinic acid salt is 10% by weight or more with respect to the total of 100% by weight of the phosphinic acid salt and other flame retardants. It is desirable to blend so as to be 40% by weight or more.

(Curable resin composition)
The curable resin composition used in the present invention contains the conjugated diene polymer, a curing agent, a filler, and a phosphinate. The curable resin composition used in the present invention may contain an antiaging agent, a curing aid, other compounding agents, and the like as desired.

  Examples of the anti-aging agent include at least one selected from the group consisting of phenol-based anti-aging agents, amine-based anti-aging agents, phosphorus-based anti-aging agents, and sulfur-based anti-aging agents, and cure such anti-aging agents. By mix | blending with an adhesive resin composition, it becomes possible to improve the oxidation degradation resistance of the obtained laminated body, without inhibiting a curing reaction. Among these anti-aging agents, phenol-based anti-aging agents and amine-based anti-aging agents are preferable, and phenol-based anti-aging agents are more preferable. These anti-aging agents can be used alone or in combination of two or more. The amount of the anti-aging agent may be appropriately selected according to the purpose of use, but is usually 0.0001 to 10 parts by weight, preferably 0.001 to 5 parts by weight, based on 100 parts by weight of the conjugated diene polymer. More preferably, it is the range of 0.01-1 weight part.

  The curing aid can be used without particular limitation as long as it is generally used industrially. For example, a bifunctional compound having two carbon-carbon unsaturated bonds and 3 carbon-carbon unsaturated bonds can be used. A polyfunctional compound such as a trifunctional or higher functional compound having at least two compounds can be given.

  Examples of other compounding agents include coloring agents. As the colorant, dyes, pigments and the like are used. There are various kinds of dyes, and known ones may be appropriately selected and used. These other additives can be used alone or in combination of two or more, and the amount used can be appropriately selected within a range not impairing the effects of the present invention.

  The curable resin composition used in the present invention can be obtained by mixing the above components. As a mixing method, it can carry out in accordance with a conventional method.

(Reinforced fiber)
The reinforcing fiber used in the present invention is not particularly limited. For example, organic fibers such as PET (polyethylene terephthalate) fiber, aramid fiber, ultrahigh molecular polyethylene fiber, polyamide (nylon) fiber, and liquid crystal polyester fiber; glass fiber , Carbon fibers, alumina fibers, tungsten fibers, molybdenum fibers, budene fibers, titanium fibers, steel fibers, boron fibers, silicon carbide fibers, silica fibers, and other inorganic fibers. Among these, organic fibers and glass fibers are preferable, and aramid fibers, liquid crystal polyester fibers, and glass fibers are particularly preferable. As the glass fiber, fibers such as E glass, NE glass, S glass, D glass, and H glass can be suitably used.

  These reinforcing fibers can be used alone or in combination of two or more. The compounding amount of the reinforcing fiber is not particularly limited and is appropriately selected depending on the purpose of use. In the prepreg or laminate, usually 10 to 90% by weight, preferably 20 to 80% by weight, more preferably 30 to 30%. It is in the range of 70% by weight. When the blending amount is within this range, the balance between the dielectric loss tangent and mechanical strength of the resin layer of the obtained laminate can be improved.

(Prepreg)
The prepreg of the present invention is produced by impregnating the reinforced resin with the curable resin composition.

As an impregnation method in producing the prepreg of the present invention, a conventional method may be used, and examples thereof include a wet method and a hot melt method (dry method). Usually, a wet method is used.
According to the wet method, a conjugated diene polymer, a curing agent, a filler, a phosphinate, and other compounding agents added as required are dissolved in a solvent to prepare a curable resin composition having a reduced viscosity. A prepreg is prepared by impregnating a reinforcing fiber with a curable resin composition having a viscosity and then removing the solvent. Examples of the solvent used in the preparation of the curable resin composition having a reduced viscosity include aromatic hydrocarbon solvents such as xylene and toluene.
According to the hot melt method (dry method), for example, a release resin is coated with a curable resin composition (substantially free of a solvent), a reinforcing fiber is aligned on the resin, and a heat-dissolved resin is applied. A prepreg is prepared by impregnating with a roll or a doctor blade and then allowing to cool.

  The drying temperature after impregnation by the wet method is usually in the range of 50 to 250 ° C., preferably 80 to 200 ° C., more preferably 90 to 150 ° C. In the present invention, in addition to the temperature range, When a radical generator is used as the curing agent, it is more preferable to set the temperature in consideration of the 1 minute half-life temperature of the radical generator. That is, the drying temperature is preferably a 1-minute half-life temperature or less, more preferably a 1-minute half-life temperature of 10 ° C. or less, and even more preferably a 1-minute half-life temperature of 20 ° C. or less. . Here, the half-life temperature for 1 minute is a temperature at which half of the radical generator decomposes in 1 minute. For example, it is 186 ° C. for di-t-butyl peroxide and 194 ° C. for 2,5-dimethyl-2,5-bis (t-butylperoxy) -3-hexyne. The drying time may be appropriately selected, but is usually in the range of 0.1 to 120 minutes, preferably 0.5 to 60 minutes, more preferably 1 to 30 minutes.

  The thickness of the prepreg of the present invention is not particularly limited and may be appropriately selected depending on the purpose of use, but is usually 0.001 to 10 mm, preferably 0.005 to 1 mm, more preferably 0.01 to 0.5 mm. Range. By making the thickness within the above range, the operability of the prepreg and the mechanical strength and toughness of the resulting laminate can be made sufficiently good.

  The amount of volatile components of the prepreg of the present invention is the amount of volatilization when heated at 200 ° C. for 1 hour, and is usually 30% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less. If the amount of volatile components in the prepreg is too large, stickiness of the prepreg will occur and the operability and storage stability will deteriorate, and voids will occur in the cured laminate, resulting in decreased appearance and mechanical strength, and bleeding. In addition, there is a tendency to cause problems such as deterioration in heat resistance and chemical resistance, which is not preferable.

(Laminate)
The laminate of the present invention is produced by laminating two or more of the prepregs of the present invention, shaping and curing as desired. Alternatively, it is produced by laminating the prepreg of the present invention above with another material (material other than the prepreg of the present invention), shaping and curing as desired.

  The other material to be laminated on the prepreg of the present invention is not particularly limited and is appropriately selected depending on the purpose of use. Examples thereof include thermoplastic resin materials and metal materials, and metal materials are particularly preferably used. It is done. As the metal material, those generally used in circuit boards can be used, and usually metal foil, preferably copper foil is used. The thickness of the metal material is not particularly limited and is appropriately selected depending on the purpose of use, but is usually 0.5 to 50 μm, preferably 1 to 30 μm, more preferably 3 to 20 μm, and further preferably 3 to 15 μm. It is.

  When a metal material is used as another material to be laminated on the prepreg of the present invention, the surface roughness (Rz) of the metal material to be adhered to the prepreg to be a resin layer in the obtained laminate is preferably 2,500 nm or less. More preferably, it is 2,000 nm or less, More preferably, it is 1,800 nm or less, Most preferably, it is 1,000 nm or less. On the other hand, the lower limit of the surface roughness is not particularly limited, but is usually 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more. If the surface roughness of the layer made of a metal material is too large in the obtained laminate, it may cause noise, delay, transmission loss, etc. in high-frequency transmission. In addition, surface roughness is calculated | required as ten-point average roughness (Rz) according to JISB0601-1994.

  As a lamination and curing method in producing the laminate of the present invention, a conventional method may be followed, for example, a known press machine having a press frame mold for flat plate molding, a sheet mold compound (SMC) or a bulk mold. Heat press can be performed using a press molding machine such as a compound (BMC).

  The heating temperature at the time of lamination and curing is a temperature at which crosslinking with a curing agent occurs. When a radical generator is used as the curing agent, it is usually at least a half-life temperature of the radical generator, preferably a radical generator. The temperature is 5 ° C. or more higher than the 1-minute half-life temperature, more preferably 10 ° C. or more higher than the 1-minute half-life temperature of the radical generator, and is usually in the range of 100 to 300 ° C., preferably 150 to 250 ° C. is there. The heating time is usually in the range of 0.1 to 180 minutes, preferably 1 to 120 minutes, more preferably 2 to 20 minutes. The pressing pressure is usually 0.1 to 20 MPa, preferably 0.1 to 10 MPa, more preferably 1 to 5 MPa. Further, the hot pressing may be performed in a vacuum or a reduced pressure atmosphere.

  The laminate of the present invention thus obtained has a high Q value of the resin layer, so that there is little transmission loss in the high frequency region, and is excellent in non-halogen flame resistance, hydrolysis resistance and acid resistance. Therefore, it can be used widely and suitably as a high-frequency substrate material. Specifically, the laminate of the present invention can be suitably used for a microwave or millimeter wave high-frequency circuit board for use in communication equipment.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to these Examples. In the examples and comparative examples, “part” and “%” are based on weight unless otherwise specified.
The test and evaluation were as follows.

(1) Q value About the laminated body, the dielectric loss (tan-delta) in 1 GHz was measured by the capacitance method at 20 degreeC using the impedance analyzer, and Q value was computed by calculating | requiring the reciprocal number (1 / tan-delta). The measurement results were evaluated according to the following criteria.
◎: Q value is 100 or more ×: Q value is less than 100

(2) Hydrolysis resistance By performing a high-temperature and high-humidity test with a high-temperature and high-humidity tester under the conditions of a temperature of 85 ° C. and a humidity of 85% for 72 hours, and measuring the mechanical strength before and after the test, The hydrolysis resistance was evaluated. In addition, the result of the hydrolysis resistance was obtained by obtaining the mechanical strength after the high-temperature and high-humidity test when the mechanical strength before the high-temperature and high-humidity test was set to 100, and was evaluated according to the following criteria. The mechanical strength was measured by a bending test method.
A: 90 or more x: Less than 90

(3) Acid resistance The acid resistance was evaluated by observing the appearance of the laminate after immersing the laminate in a 10% sulfuric acid aqueous solution for 1 hour. Evaluation was performed according to the following criteria.
A: No change in shape or color was observed.
X: Change in shape or color was observed.

(4) Flame retardancy Cut the laminate to 125 mm × 15 mm × 0.9 mm, and let the flame close to 8 cm below the sample in the longitudinal direction of the sample and let it stand for 10 seconds, then take off the flame, The flame retardancy was evaluated by observing the subsequent burning. Evaluation was performed according to the following criteria.
(Double-circle): There was no flaming after flare-off.
○: Although there was flaming after taking off the flame, it disappeared soon.
X: The flame after the flare reached the top of the sample and burned.

Example 1
100 parts of polybutadiene as a conjugated diene polymer (polybutadiene resin B3000, manufactured by Nippon Soda Co., Ltd., weight average molecular weight 3,000, 1,2-vinyl bond content 95 mol%), styrene-butadiene block as a conjugated diene polymer 20 parts of polymer (product name “Tufprene”, manufactured by Asahi Kasei Co., Ltd.), 70 parts of aluminum diethylphosphinate as a flame retardant, silica (product name “Admafine”, manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) ) 350 parts and 1.2 parts of di-t-butyl peroxide (1 minute half-life temperature: 186 ° C.) were mixed in xylene to obtain a curable resin composition. Next, the obtained curable resin composition was impregnated into glass cloth (E glass) and heated to remove xylene as a solvent to prepare a sheet-like prepreg. The reinforcing fiber (glass cloth) content in the prepreg was 50%.

  Next, 5 sheets of the prepared prepreg sheets were stacked, and the laminated prepreg sheets were sandwiched with 12 μm electrolytic copper foil (type F0, manufactured by Furukawa Circuit Foil Co., Ltd., surface roughness Rz = 700 nm). The laminate was obtained by performing a heat press at 3 MPa for 3 minutes. And according to the said method, each evaluation of Q value, hydrolysis resistance, acid resistance, and a flame retardance was performed about the obtained laminated body. The results are shown in Table 1.

Example 2
A prepreg and a laminate were produced in the same manner as in Example 1 except that 70 parts of zinc diethylphosphinate were used in place of 70 parts of aluminum diethylphosphinate, and the resulting laminate was treated in the same manner as in Example 1. Each evaluation was performed. The results are shown in Table 1.

Comparative Example 1
A prepreg and a laminate were produced in the same manner as in Example 1 except that 100 parts of magnesium hydroxide was used instead of 70 parts of aluminum diethylphosphinate, and the resulting laminate was treated in the same manner as in Example 1. Evaluation was performed. The results are shown in Table 1.

As shown in Table 1, by adding a curable resin composition to a conjugated diene polymer, a curing agent, and a filler, and including a phosphinic acid salt as a flame retardant, the obtained laminate has a Q value, The results were excellent in hydrolysis resistance, acid resistance and non-halogen flame resistance (Examples 1 and 2).
On the other hand, when magnesium hydroxide was used instead of the phosphinate as a flame retardant, the resulting laminate was inferior in hydrolysis resistance, acid resistance and flame resistance (comparison) Example 1).

Claims (2)

  A prepreg obtained by impregnating reinforcing fibers with a curable resin composition containing a conjugated diene polymer, a curing agent, a filler, and a phosphinate.   The laminated body obtained by laminating | stacking the prepreg of Claim 1, and the said prepreg or another material, and hardening | curing.