JP2011098993A - Prepreg containing amine antioxidant, and laminated product obtained using the prepreg - Google Patents

Abstract

A prepreg capable of producing a laminate that has high heat resistance and can be suitably used as a high-frequency circuit board material for a long time in a wide temperature range, and a laminate using the prepreg.
A prepreg obtained by impregnating a reinforcing fiber with a curable composition containing a conjugated diene polymer, a radical generator, and an amine anti-aging agent, and the above prepreg, or the other prepregs. A laminate obtained by curing after being laminated with a material has high heat resistance and can be suitably used as a high-frequency circuit board material for a long time in a wide temperature range.
[Selection figure] None

Description

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

  A circuit board is generally composed of a dielectric layer and a conductor layer. In recent years, with the advent of advanced information era, information transmission has started to move to higher speeds and higher frequencies, and microwave communication and millimeter wave communication have become a reality. In circuit boards in these high frequency eras, it is necessary to reduce noise and transmission loss at high frequencies as much as possible, and selection of a dielectric material having a low dielectric loss tangent (tan δ) has become an important issue.

  As dielectric materials having a low dielectric loss tangent, conjugated diene polymers such as polybutadiene and polyisoprene are attracting attention. For example, Patent Document 1 discloses 1,2-polybutadiene having a molecular weight of less than 5,000 at room temperature, a thermoplastic block copolymer such as styrene-butadiene-styrene triblock copolymer which is a solid polymer, dicumyl peroxide and t-butyl. Fiber reinforcing material as slurry by mixing organic peroxide such as peroxyhexine-3 and bromine-containing flame retardant such as ethylenebistetrabromophthalimide, tetradecabromodiphenoxybenzene, decabromodiphenoxyloxide, etc. in a solvent A laminated body is disclosed in which a solvent is removed after impregnating to prepreg to prepare a prepreg, and then a plurality of prepregs are laminated between two copper foils and cured. However, the laminate obtained by this method has a problem that the heat resistance is not sufficient, and when held at a high temperature, the dielectric loss tangent is increased and the mechanical properties are greatly deteriorated.

  On the other hand, in Patent Document 2, an ethylene-propylene polymer having a weight average molecular weight of less than 50,000 is added to a circuit board material containing a polybutadiene or polyisoprene polymer, a flame retardant, a knitted fabric, a particulate filler, and an organic peroxide. It is disclosed that by containing 6 to 12% by weight in the total polymer, there is little deterioration due to heat and stability such as dielectric constant is improved. However, this method has a problem that sufficient heat resistance cannot be obtained. In this method, Naugard (2,2-oxalyl diamidobis [ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) proprionate is used as an anti-aging agent in a heat deterioration test at 210 ° C. ]), No improvement effect was observed.

JP-A-8-208856 Special table 2003-528450 gazette

  An object of the present invention is to produce a laminate having high heat resistance using a conjugated diene polymer such as polybutadiene or polyisoprene having a low dielectric loss tangent, which can be suitably used as a high-frequency circuit board material for a long time in a wide temperature range. An object of the present invention is to provide a prepreg that can be manufactured and a laminate using the prepreg.

  As a result of intensive studies in view of the above problems, the present inventors have added an amine-based antioxidant to a curable composition containing a conjugated diene polymer such as 1,2-polybutadiene and a styrene-butadiene block copolymer and a radical generator. It has been found that the heat resistance can be improved with a low dielectric loss tangent without inhibiting the activity of the radical generator. In addition, it has been found that these effects are remarkably improved by using a secondary amine-based anti-aging agent, particularly a diphenylamine-based anti-aging agent, as the amine-based anti-aging agent. The present inventors also added a specific amount of amine-based anti-aging agent to the conjugated diene polymer or to the radical generator, thereby preventing heat-resistant reaction without inhibiting the crosslinking reaction of the conjugated diene polymer. It has been found that the sex is also improved. The present inventors have completed the invention based on these findings.

Thus, according to the present invention, there is provided a prepreg obtained by impregnating reinforcing fibers with a curable composition containing a conjugated diene polymer, a radical generator, and an amine antioxidant.
According to the present invention, there is also provided a laminate obtained by curing the above-described prepreg with each other or with another material.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated body excellent in heat resistance and the prepreg which gives it can be easily manufactured using polybutadiene or polyisoprene with a low dielectric loss tangent. Further, since the laminate of the present invention has a low dielectric loss tangent and excellent heat resistance, it can be suitably used for a high-frequency circuit board such as a microwave or millimeter wave for use in communication equipment.

(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, but at least one selected from the group consisting of a conjugated diene homopolymer and a conjugated diene copolymer is preferable. Used for. These polymerization modes are appropriately selected according to the purpose of use and can be carried out according to a conventional method.

  Examples of the conjugated diene include butadiene, isoprene, chloroprene, pentadiene and the like, preferably butadiene and isoprene, and more preferably butadiene.

  The conjugated diene homopolymer is not particularly limited as long as it is obtained by polymerizing a conjugated diene. For example, polybutadiene, polyisoprene, polychloroprene, polycyanobutadiene, polypentadiene, and the like, preferably polybutadiene, Polyisoprene, more preferably polybutadiene.

  The conjugated diene copolymer is not particularly limited as long as it is a copolymer containing at least a conjugated diene. For example, a random copolymer or a block copolymer can be used.

  The monomer to be copolymerized is not particularly limited as long as it is a monomer copolymerizable with a conjugated diene. For example, cyano group-containing vinyl, amino group-containing vinyl, pyridyl group-containing vinyl, alkoxyl group-containing vinyl, aromatic vinyl, etc. Among these, cyano group-containing vinyl and aromatic vinyl are preferable, and aromatic vinyl is particularly preferable. Examples of the aromatic vinyl include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, and 4-t-butylstyrene. , 5-t-butyl-2-methylstyrene, N, N-dimethylaminoethylstyrene, N, N-diethylaminoethylstyrene and the like, among which styrene and α-methylstyrene are particularly preferable.

  The ratio of the conjugated diene and the copolymerization monomer in the conjugated diene copolymer is appropriately selected according to the purpose of use, and is usually 95/5 to 5/95, preferably 90/10, as the weight ratio of the conjugated diene / copolymerization monomer. 10/90, more preferably in the range of 80/20 to 20/80, and in this range, the properties of the laminate, such as heat resistance, mechanical strength and toughness, are highly balanced and suitable.

  The coupling mode of the conjugated diene block copolymer is usually appropriately selected according to the purpose of use, such as a 2-block copolymer, 3-block copolymer, 4-block copolymer, 5-block copolymer, etc., but 2-block copolymer and 3-block copolymer are preferred. Triblock copolymers are particularly preferred because they can maintain a high balance of the laminateability, heat resistance and mechanical strength of the prepreg and laminate. Specific examples of the triblock copolymer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, α-methylstyrene-butadiene-α-methylstyrene block copolymer, and preferably styrene-butadiene-styrene. It is a block copolymer.

  The amount of 1,2-vinyl bond in the conjugated diene part of the conjugated diene polymer used in the present invention is appropriately selected according to the purpose of use, but is usually 5 mol% or more, preferably 40 mol% or more, more preferably Is at least 60 mol%, most preferably at least 80 mol%. When the 1,2-vinyl bond amount is within this range, the mechanical strength and heat resistance of the laminate can be improved to a high degree, which is preferable.

  The molecular weight of the conjugated diene polymer when the conjugated diene homopolymer or conjugated diene copolymer is used alone can be appropriately selected according to the purpose of use, but is measured by gel permeation chromatography (polystyrene equivalent toluene eluent). The weight average molecular weight is usually in the range of 500 to 5,000,000, preferably 1,000 to 1,000,000.

  In the present invention, the conjugated diene polymers can be used singly or in combination of two or more. However, by combining a conjugated diene homopolymer and a conjugated diene copolymer, the prepreg laminateability and the heat resistance of the laminate can be improved. It is preferable because properties such as property and mechanical properties can be highly balanced.

  When combining a conjugated diene homopolymer and a conjugated diene copolymer, the molecular weight of the conjugated diene homopolymer is a weight average molecular weight measured by gel permeation chromatography (polystyrene equivalent toluene eluent), usually 500 to 500, 000, preferably 1,000 to 10,000, more preferably 1,000 to 5,000. When combined, the molecular weight of the conjugated diene copolymer is a weight average molecular weight measured by gel permeation chromatography (polystyrene equivalent toluene eluent), and is usually 1,000 to 1,000,000, preferably 5,000 to It is in the range of 500,000, more preferably 10,000 to 300,000. When the molecular weights of the conjugated diene homopolymer and the conjugated diene copolymer are within this range, the relationship between the laminate property of the laminate and the mechanical strength can be highly balanced, which is preferable.

  The ratio to be used when combining the conjugated diene homopolymer and the conjugated diene copolymer is appropriately selected according to the purpose of use, but is usually 10/90 to 10/90 by weight ratio of the conjugated diene homopolymer / conjugated diene copolymer. It is in the range of 95/5, preferably 30/70 to 90/10, more preferably 50/50 to 85/15. When the ratio of both is in this range, characteristics such as heat resistance, mechanical characteristics, dielectric loss tangent and the like of the laminate are highly balanced.

(Radical generator)
The radical generator used in the present invention is not particularly limited as long as it can crosslink the conjugated diene polymer, and usually includes organic peroxides, diazo compounds, nonpolar radical generators, and the like. Peroxides and nonpolar radical generators are particularly suitable for lowering the dielectric loss tangent of the laminate.

  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; and the like. Of these, dialkyl peroxides and peroxyketals are preferable. Examples of the diazo compound include 4,4'-bisazidobenzal (4-methyl) cyclohexanone and 2,6-bis (4'-azidobenzal) cyclohexanone.

  Nonpolar radical generators include 2,3-dimethyl-2,3-diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, 1,1,2-triphenylethane, 1,1,1- And triphenyl-2-phenylethane.

  The 1-minute half-life temperature of the radical generator used in the present invention is appropriately selected depending on the type and use conditions of the radical generator, but is usually 50 to 350 ° C, preferably 100 to 250 ° C, more preferably 150. It is in the range of ~ 230 ° C.

  These radical generators can be used alone or in combination of two or more. The amount of the radical generator used is usually in the range of 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. It is.

(Amine-based anti-aging agent)
In the present invention, an amine anti-aging agent is used as the anti-aging agent.
The amine-based anti-aging agent is not particularly limited as long as it is an antioxidant having an amino group, and primary amine-based anti-aging agents and secondary amine-based anti-aging agents are usually used. Secondary amines are used.

Examples of the primary amine-based antiaging agent include aldol-α-naphthylamine, acetaldehyde aniline, p, p′-diaminodiphenylmethane, and the like.
Examples of the secondary amine antioxidant include 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, and the like. Secondary amine / ketone anti-aging agent: N-phenyl-1-naphthylamine, octylated diphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, p- (p-toluenesulfonylamide) diphenylamine, N, N′-di-2-naphthyl-p-phenylenediamine, N, N′-diphenyl-p-phenylenediamine, N-phenyl-N′-isopropyl-p-phenylenediamine, N-phenyl-N ′-( 1,3-dimethylbutyl) -p-phenylenediamine, N-phenyl-N ′-(3-methacryloyloxy-2-hydroxypropyl) -Diphenylamine anti-aging agent which is a compound having a diphenylamine structure in the molecule such as -p-phenylenediamine. Among these, diphenylamine-based antioxidants having a high volatility point are preferable, and in particular, N-phenyl-1-naphthylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, p- (p-toluenesulfonyl) Amide) diphenylamine, N, N′-di-2-naphthyl-p-phenylenediamine, N, N′-diphenyl-p-phenylenediamine, and other diphenylamine-based antioxidants having three or more aromatic rings are preferred.
These amine-based antioxidants can be used alone or in combination of two or more.

  The amount of the amine-based anti-aging agent is 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 with respect to 100 parts by weight of the conjugated diene polymer. More preferably, it is in the range of 0.01 to 1 part by weight.

  The use ratio of the amine-based anti-aging agent and the radical generator is appropriately selected according to the purpose of use, but is usually an amine-based anti-aging agent / radical generator (weight ratio), usually 1/99 to 90/10, The range is preferably 2/98 to 70/30, more preferably 3/97 to 50/50. When the ratio of the amine-based anti-aging agent and the radical generator is within this range, the heat resistance of the laminate can be improved without inhibiting the crosslinking reaction of the conjugated diene polymer.

(Curable composition)
The curable composition used in the present invention contains the conjugated diene polymer, radical generator, and amine-based anti-aging agent as essential components, and if necessary, a filler, a crosslinking aid, a flame retardant, and other components. A compounding agent etc. can be added.

  In the present invention, it is preferable that heat resistance can be further improved by adding a filler to the curable composition. The filler used is not particularly limited as long as it is generally used industrially, and any of inorganic fillers and organic fillers can be used, but inorganic fillers are preferred. .

  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, antimony oxide, beryllium oxide, barium ferrite and strontium ferrite; inorganic hydroxide particles such as aluminum hydroxide and magnesium hydroxide; calcium carbonate Inorganic carbonate particles such as magnesium carbonate and sodium hydrogen carbonate; inorganic sulfate particles such as calcium sulfate; inorganic silicates such as talc, clay, mica, kaolin, fly ash, montmorillonite, calcium silicate, glass, glass balloon Particles: calcium titanate , Titanate particles such as lead zirconate titanate, aluminum nitride, silicon carbide particles and whiskers, and the like. Among these, metal particles, inorganic oxide particles, inorganic hydroxide particles, inorganic silicate particles, titanate particles, and the like are preferable for highly balancing the dielectric loss tangent and heat resistance of the laminate. Oxide particles and titanates are more preferred.

Examples of the organic filler include particulate compounds such as wood flour, 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, and the addition amount is usually 10 to 1,000 parts by weight, preferably 50 parts per 100 parts by weight of the conjugated diene polymer. It is -750 weight part, More preferably, it is the range of 100-500 weight part.

  In the present invention, by adding a crosslinking aid to the curable composition, the impregnation property of the curable composition into the reinforcing fibers can be highly improved, and the mechanical strength of the laminate obtained by curing can be increased. Heat resistance is highly balanced, which is preferable.

As the crosslinking aid, those used industrially can be used without particular limitation. For example, bifunctional crosslinking aids such as p-diisopropenylbenzene, m-diisopropenylbenzene, and o-diisopropenylbenzene are used. Agents, trifunctional crosslinking aids such as triisopropenylbenzene and trimethallyl isocyanate.
These crosslinking aids can be used alone or in combination of two or more. The amount of the crosslinking aid is appropriately selected according to the purpose of use, but is usually 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight, more preferably 100 parts by weight of the conjugated diene polymer. Is in the range of 1 to 20 parts by weight.

In this invention, a flame retardance is provided to a laminated body by adding a flame retardant to a curable composition, and it is suitable.
As the flame retardant to be used, industrially used ones can be used without particular limitation. For example, any of halogen-based flame retardants and non-halogen flame retardants can be used.

  The halogen-based flame retardant is a flame retardant containing a halogen atom. Examples of halogen flame retardants include hexabromobenzene, decabromodiphenyl oxide, bis (tribromophenoxy) ethane, 1,2-bis (pentabromophenyl) ethane, tetrabromobisphenol S, tetradecabromodiphenoxybenzene, 2,2-bis (4-hydroxy-3,5-dibromophenylpropane), pentabromotoluene, tris (2-chloroethyl) phosphate, tris (chloropropyl) phosphate, tris (dichloropropyl) phosphate, tris (tribromoneo Low molecular halogen-containing organic compounds such as pentyl phosphate and halogen-containing condensed phosphates; halogenated paraffins having a halogen content of 40 to 70% by weight; halogenated elastomers; chlorinated polystyrene, iodinated polystyrene Halogenated polystyrene such as high chlorinated polyethylene, high chlorinated polypropylene, chlorosulfonated polyethylene and the like having a halogen content of 50% by weight or more; Halogenated polyvinyl chloride such as chlorinated polyvinyl chloride; The thing of high molecular weight is mentioned.

  Non-halogen flame retardants are flame retardants that do not contain halogen atoms, including, for example, metal hydroxide flame retardants, metal oxide flame retardants, phosphorus flame retardants, nitrogen flame retardants, both phosphorus and nitrogen And flame retardant.

  Examples of the metal hydroxide flame retardant include aluminum hydroxide and magnesium hydroxide. Examples of the metal oxide flame retardant include magnesium oxide and aluminum oxide. Examples of phosphorus flame retardants include red phosphorus and phosphate esters. Examples of phosphate esters include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, resorcinol bis (diphenyl) phosphate, bisphenol A bis (diphenyl) phosphate, bisphenol A bis (dicresyl) phosphate, and the like. However, a tertiary phosphate ester having a relatively high molecular weight such as tricresyl phosphate, resorcinol bis (diphenyl) phosphate, bisphenol A bis (diphenyl) phosphate, bisphenol A bis (dicresyl) phosphate, and the like is preferable.

  The nitrogen-based flame retardant is not particularly limited as long as it is a flame retardant containing nitrogen, and examples thereof include melamine derivatives, guanidines, isocyanuric acid, and preferably melamine derivatives. Examples of the melamine derivatives include melamine, melamine resin, melam, melem, melamine cyanurate, succinoguanamine, ethylene dimelamine, triguanamine, melamine sulfate, guanylmelamine sulfate, melam sulfate, melem sulfate, Melamine sulfate is preferred. Examples of guanidines include guanidine nitrate, guanidine carbonate, guanidine sulfamate, aminoguanidine nitrate, aminoguanidine bicarbonate, and preferably guanidine nitrate.

  Examples of the flame retardant containing both phosphorus and nitrogen include ammonium polyphosphate, melamine phosphate, melamine polyphosphate, melam polyphosphate, guanidine phosphate, and phosphazenes, preferably ammonium polyphosphate and melamine polyphosphate. , Melam polyphosphate.

  These flame retardants can be used alone or in combination of two or more. The amount of the flame retardant added is usually in the range of 10 to 300 parts by weight, preferably 20 to 200 parts by weight, more preferably 30 to 150 parts by weight with respect to 100 parts by weight of the conjugated diene polymer.

  Examples of other compounding agents include other polymer components, other anti-aging agents, colorants, dyes, and pigments. These other additives can be used alone or in combination of two or more, and the amount used is appropriately selected within a range not impairing the effects of the present invention.

  The curable composition used for this invention can be obtained by mixing the said component. Mixing can be performed according to 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; And inorganic fibers such as glass fibers, carbon fibers, alumina fibers, tungsten fibers, molybdenum fibers, budene fibers, titanium fibers, steel fibers, boron fibers, silicon carbide fibers, silica fibers, and the like. 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 amount of reinforcing fibers used is appropriately selected according to the purpose of use, but is usually in the range of 10 to 90% by weight, preferably 20 to 80% by weight, more preferably 30 to 70% by weight in the prepreg or laminate. In this range, the dielectric loss tangent and heat resistance of the laminate are highly balanced, which is preferable.

(Prepreg)
The prepreg of the present invention can be produced by impregnating the curable composition into the reinforcing fiber.
As an impregnation method, a conventional method may be followed. For example, a conjugated diene polymer, a radical generator, an amine anti-aging agent, and, if necessary, a filler, a crosslinking aid, a flame retardant, and other compounding agents. A wet method in which a curable composition that has been dissolved in a solvent and reduced in viscosity is impregnated into a reinforced fiber and then desolvated. The curable composition is coated on a release paper, and the reinforced fiber is aligned on it and heated to dissolve. A hot melt method (dry method) in which the curable composition is impregnated under pressure with a roll or a doctor blade and then allowed to cool can be used. Usually, a wet method is used.

  The drying temperature after impregnation by the wet method is usually in the range of 50 to 250 ° C., preferably 100 to 200 ° C., more preferably 120 to 170 ° C., and usually below the 1 minute half-life temperature of the radical generator, preferably The temperature is 10 ° C. or more lower than the 1 minute half-life temperature, more preferably 20 ° C. or more lower than the 1 minute half-life temperature. 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.

  Although the thickness of the prepreg of this invention is suitably selected according to the intended purpose, it is 0.001-10 mm normally, Preferably it is 0.01-1 mm, More preferably, it is the range of 0.05-0.5 mm. When the thickness of the prepreg is within this range, the operability of the prepreg and the mechanical strength and toughness of the laminate obtained by curing are sufficiently exhibited, which is preferable.

  The amount of the volatile component in the prepreg of the present invention is an amount that volatilizes when the prepreg is left at 200 ° C. for 1 hour, and is usually 30% by weight or less, preferably 10% by weight or less, more preferably 5% in the total curable composition. % By weight or less, most preferably 1% by weight or less. When the amount of volatile components in the prepreg is excessively large, the prepreg after drying remains sticky, and the operability and storage stability of the prepreg deteriorate. Further, voids are generated in the prepreg and the laminate, which deteriorates the appearance and mechanical strength, and causes problems such as bleeding, heat resistance and chemical resistance of the laminate.

(Laminate)
The laminate of the present invention can be produced by curing the above prepreg with the same prepreg or with other materials and shaping as necessary.
The other material that may be laminated is appropriately selected according to the purpose of use, and examples thereof include a thermoplastic resin material and a metal material, and preferably a metal material. As the metal material, those generally used for circuit boards can be used without particular limitation, and usually metal foil, preferably copper foil is used. Although the thickness of a metal material is suitably selected according to the intended purpose, it is 1-50 micrometers normally, Preferably it is 3-30 micrometers, More preferably, it is 5-20 micrometers, Most preferably, it is the range of 5-15 micrometers.

  The method for laminating and curing the prepreg may be in accordance with a conventional method, for example, a known press having a press frame mold for flat plate molding, a press molding machine such as a sheet mold compound (SMC) or a bulk mold compound (BMC). Can be carried out by hot pressing using The heating temperature is a temperature at which crosslinking by a radical generator occurs, and is usually at least 1 minute half-life temperature, preferably at least 5 ° C. above 1-minute half-life temperature, more preferably at least 10 ° C. above 1-minute half-life temperature. Temperature. Usually, it is 100-300 degreeC, Preferably it is the range of 150-250 degreeC. The heating time is 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 can be suitably used as a high-frequency substrate material for a long time under a wide range of temperatures, since it has low transmission loss in the high-frequency region and excellent heat resistance.

  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.

Each characteristic in an Example and a comparative example was measured and evaluated according to the following method.
(1) Dielectric loss tangent: The dielectric loss tangent (tan δ) at 1 GHz of the laminate was measured by a capacitance method using an impedance analyzer, and the dielectric loss tangent of Comparative Example 1 was set to 100, and judged according to the following criteria.
○: 100 or less ×: More than 100 (2) Heat resistance (dielectric loss tangent): The obtained laminate was held at 230 ° C. for 30 days, then cut into 2 × 2 cm ³ , and the laminate was measured using an impedance analyzer. The dielectric loss tangent (tan δ) at 1 GHz was measured by a capacitance method. (Tan δ after holding) / (tan δ before holding) was calculated and judged according to the following criteria.
○: Less than 2.0 Δ: 2.0 or more and less than 4.0 ×: 4.0 or more (3) Heat resistance (mechanical strength): After the obtained laminate was held at 230 ° C. for 30 days, 0 Cut to 5 × 3 cm ³ , the tensile strength of the laminate was measured according to ASTM D638 using a tensile tester. (Tensile strength after holding) / (Tensile strength before holding) was calculated and judged according to the following criteria.
○: 0.75 or more △: 0.5 or more and less than 0.75 ×: Less than 0.5

Example 1
Polybutadiene homopolymer B3000 (manufactured by Nippon Soda Co., Ltd .; molecular weight 3000, 1,2-vinyl bond content 95 mol%) 100 parts, styrene-butadiene-styrene block copolymer Toughprene A (manufactured by Asahi Kasei Co., Ltd.), bisphenol A bis as a flame retardant 80 parts of (dicresyl) phosphate, 35 parts of silica (manufactured by Admafine 0.5 μm), 1.2 parts of di-t-butyl peroxide as a radical generator and 6-ethoxy-1,2-dihydro- as an amine-based antioxidant One part of 2,2,4-trimethylquinoline was mixed in xylene to obtain a curable composition. Next, a glass cloth (E glass) was impregnated with the obtained curable composition, and the solvent was removed by heating to prepare a prepreg. The reinforcing fiber content of the prepreg was 41%.

  Next, 5 sheets of the prepared prepregs were stacked, and heated at 200 ° C. for 10 minutes at 3 MPa to obtain a laminate. The dielectric loss tangent and heat resistance of the obtained laminate were evaluated, and the results are summarized in Table 1.

Example 2
A prepreg and a laminate were prepared in the same manner as in Example 1 except that the amine anti-aging agent was changed to 4,4′-bis (α, α-dimethylbenzyl) diphenylamine. Summarized in

Comparative Example 1
A prepreg and a laminate were prepared in the same manner as in Example 1 except that the anti-aging agent was not used. The characteristics were evaluated and the results are summarized in Table 1.

Comparative Example 2
Ethylene-propylene-dicyclopentadiene random copolymer A prepreg and a laminate were prepared in the same manner as in Comparative Example 1 except that 10 parts of tolylene 54 (Uniroy Corp .; weight average molecular weight: 30000) was added, and the characteristics were evaluated. Are summarized in Table 1.

Comparative Example 3
The prepreg and laminate as in Comparative Example 2 except that 1 part of 2-oxalyldiamidobis [ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) proprionate]) was added as an antioxidant. The characteristics were evaluated and the results are summarized in Table 1.

Claims (7)

A prepreg obtained by impregnating reinforcing fibers with a curable composition containing a conjugated diene polymer, a radical generator, and an amine antioxidant. The prepreg according to claim 1, wherein 0.001 to 10 parts by weight of an amine anti-aging agent is blended with 100 parts by weight of the conjugated diene polymer. The prepreg according to claim 1 or 2, wherein the weight ratio of amine-based antioxidant / radical generator is in the range of 1/99 to 90/10. The prepreg according to any one of claims 1 to 3, wherein the amine-based anti-aging agent is a secondary amine-based anti-aging agent. The prepreg according to claim 4, wherein the secondary amine anti-aging agent is a diphenylamine anti-aging agent. The prepreg according to any one of claims 1 to 5, wherein the curable composition comprises a flame retardant. A laminate obtained by curing the prepreg according to any one of claims 1 to 6 between the prepregs or laminated with another material.