JP2015063605A - Prepreg using organic fiber base material and laminate plate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prepreg using a thermosetting resin composition having excellent low thermal expansion properties and to provide a laminate plate using the prepreg.SOLUTION: There is provided a prepreg obtained by impregnating or coating an organic fiber base material with a compatibilizing resin obtained by iminocarbonation reaction and triazine cyclization reaction of a siloxane resin (a) having a hydroxyl group at the terminal represented by the following general formula (I), a compound (b) having at least two cyanate groups in one molecule, a compound (C) having at two epoxy groups in one molecule and an organic metal salt (d) as a reaction catalyst in a solvent and a thermosetting resin composition comprising a compound containing an imidazole structure in the molecular structure. (where, Rs each independently is a saturated hydrocarbon group having 1 to 5 carbon atoms; Ars each independently is not present or is an aromatic group; and m is a number of 5 to 100.)

Description

  The present invention relates to a prepreg using a thermosetting resin composition excellent in low thermal expansion, and a laminate.

  Thermosetting resin compositions have a cross-linked structure and exhibit high heat resistance and dimensional stability, and thus are widely used in the fields of electronic devices and the like. In particular, it is used as a printed wiring board on which wirings and circuit patterns are printed, a prepreg constituting a copper-clad laminate in which printed wiring boards are multilayered, and an interlayer insulating material.

  In recent years, electronic devices have become smaller and lighter, and the operating frequency has been increased, and printed wiring and circuit patterns have been highly integrated. As high integration methods, proposals have been made for miniaturization of printed wiring and circuit patterns formed on a printed wiring board, multilayering of circuit boards on which circuit patterns are formed, or a combination thereof.

  In addition, with the high integration of printed wiring, low thermal expansion is particularly required for printed wiring boards. Patent Documents 1, 2 and 3 disclose resin compositions comprising a cyanate compound and an inorganic filler and exhibiting low thermal expansibility.

JP 2003-268136 A JP 2003-73543 A JP 2002-285015 A

  The resin compositions disclosed in Patent Documents 1, 2, and 3 have a large amount of inorganic filler in order to develop low thermal expansibility, and when used as a copper clad laminate or an interlayer insulating material, There were problems such as insufficient moldability.

  This invention is made | formed in view of such a condition, and it aims at providing the prepreg using the thermosetting resin composition excellent in low thermal expansibility, and the laminated board using this prepreg.

The present invention is a prepreg obtained by impregnating or coating a thermosetting resin composition on an organic fiber base material, the thermosetting resin composition comprising:
A siloxane resin (a) having a hydroxyl group at the terminal represented by the following general formula (I), a compound (b) having at least two cyanate groups in one molecule, and at least two epoxy groups in one molecule The amount of (a) used per 100 parts by mass of the total of (a), (b), and (c) is 10 to 50 parts by mass of the compound (c) having the organic metal salt (d) as a reaction catalyst The amount of (b) used is in the range of 40 to 80 parts by mass, the amount of (c) used is in the range of 10 to 50 parts by mass, and these are 80 ° C. in a solvent previously selected from toluene, xylene and mesitylene. Manufactured by performing an imino carbonate reaction and a triazine cyclization reaction at a reaction temperature of ˜120 ° C., and pre-reacting so that the reaction rate (disappearance rate) of the compound having a cyanate group in (b) is 30 to 70 mol%. The That compatible resin,
And a prepreg which is a thermosetting resin composition containing a compound containing an imidazole structure in the molecular structure.

  Further, in the present invention, the organic fiber constituting the organic fiber base material is an aramid resin, an aromatic polyether ketone resin, a polyparaphenylene benzobisoxazole (PBO) resin, a polyester resin, an aromatic polyester resin, a polyimide resin, The present invention relates to the prepreg which is a base material composed of at least one resin selected from the group consisting of ultrahigh molecular weight polyethylene and tetrafluoroethylene resin.

  Moreover, this invention relates to the said prepreg by which the said organic fiber base material is surface-treated by either a silane coupling agent, a corona treatment, and a plasma treatment.

  Moreover, this invention relates to the laminated board obtained by shape | molding the said prepreg.

  ADVANTAGE OF THE INVENTION According to this invention, the prepreg excellent in low thermal expansibility and a laminated board using the same can be provided.

  Hereinafter, preferred embodiments of a prepreg according to the present invention and a laminate using the prepreg will be described in detail.

  The thermosetting resin composition used in the present embodiment includes (1) (a) a siloxane resin containing a hydroxyl group having a structure represented by the general formula (I), and (b) at least two cyanates in one molecule. A compound having a group, (c) a compound having at least two epoxy groups in one molecule, (d) an organometallic salt as a reaction catalyst, an imino carbonate reaction in an aromatic organic solvent, and a triazine ring It is a resin composition containing a compatibilizing resin obtained by the chemical reaction and (2) a compound containing an imidazole structure in the molecular structure.

  The siloxane resin which is the component (a) of the thermosetting resin composition used in the present embodiment is not particularly limited as long as it is a siloxane resin containing a hydroxyl group having a structure represented by the general formula (I). For example, trade name X-22-1821 (hydroxyl value: 30 KOHmg / g), trade name X-22-1822 (hydroxyl value: 20 KOHmg / g), Toray Product name BY16-752A (hydroxyl value: 30 KOHmg / g) manufactured by Dow Corning Co., Ltd., and product name X-22-160AS (hydroxyl value: 112 KOHmg / g) manufactured by Shin-Etsu Chemical Co., Ltd. in which both ends are alcoholic hydroxyl groups. ), Trade name KF-6001 (hydroxyl value: 62 KOHmg / g), trade name KF-6002 (hydroxyl value: 35 KOHmg / g), trade name KF-6003 (hydroxyl value: 20 KOHmg / g), trade name X-22 4015 (hydroxyl value: 27 KOHmg / g) and the like. These are commercially available from Shin-Etsu Chemical Co., Ltd. and Toray Dow Corning Co., Ltd.

  The compound having at least two cyanate groups in one molecule which is the component (b) of the thermosetting resin composition used in the present embodiment is, for example, a novolak type cyanate resin, a bisphenol A type cyanate resin, or a bisphenol E type cyanate. Examples thereof include resins, bisphenol F-type cyanate resins, and tetramethylbisphenol F-type cyanate resins, which can be used alone or in combination. Among these, bisphenol A-type cyanate resins and novolak-type cyanate resins represented by the following general formula (II) are particularly preferable from the viewpoints of dielectric properties, heat resistance, flame retardancy, low thermal expansion, and low cost.

  Although the average repeating number: m of the novolak-type cyanate resin represented by the general formula (II) is not particularly limited, 0.1 to 30 is preferable. When it is more than 0.1, crystallization is suppressed and handling is easy, and when it is less than 30, the cured product is hardly brittle.

  The compound having at least two epoxy groups in one molecule, which is the component (c) of the thermosetting resin composition used in the present embodiment, includes, for example, bisphenol A, bisphenol F, biphenyl, novolac, Examples thereof include glycidyl ethers such as functional phenols, naphthalenes, alicyclics, and alcohols, glycidylamines, and glycidyl esters, which can be used alone or in combination. Among these, both naphthalene type epoxy resin, naphthol aralkyl type epoxy resin, dihydroxynaphthalene aralkyl type epoxy resin, naphthol aralkyl cresol and naphthol aralkyl / cresol are used in terms of high rigidity, dielectric properties, heat resistance, flame resistance, moisture resistance and low thermal expansion. Naphthalene ring-containing epoxy resins such as polymerization type epoxy resins, biphenyl type epoxy resins, biphenyl group-containing epoxy resins such as biphenyl aralkyl type epoxy resins are preferred, and naphthol aralkyl type epoxy resins from the viewpoint of solubility in aromatic organic solvents, A naphthol aralkyl / cresol copolymer type epoxy resin and a biphenyl type epoxy resin are more preferred, and a biphenyl type epoxy resin represented by the following formula (III) is particularly preferred because it is inexpensive and has a small epoxy equivalent and may contain a small amount.

  Examples of the organometallic salt of the reaction catalyst that is the component (d) of the thermosetting resin composition used in the present embodiment include zinc naphthenate, cobalt naphthenate, tin octylate, and cobalt octylate.

  The amount of (a) used per 100 parts by mass of the sum of (a), (b) and (c) is in the range of 10 to 50 parts by mass, and the amount of (b) is in the range of 40 to 80 parts by mass. The amount of (c) used is in the range of 10 to 50 parts by mass, these are uniformly dissolved in advance in a solvent selected from toluene, xylene, and mesitylene, and iminocarbonate formation reaction at a reaction temperature of 80 ° C to 120 ° C, and It is necessary to carry out a pre-reaction so that the reaction rate (disappearance rate) of the compound having a cyanate group (b) is 30 to 70 mol% by triazine cyclization reaction. Here, the reaction solvent must be an aromatic solvent selected from toluene, xylene, and mesitylene, and a small amount of other solvent may be used if necessary, but the desired reaction does not proceed, heat resistance, etc. May decrease. In addition, benzene is highly toxic, and an aromatic solvent having a molecular weight larger than that of mesitylene is not preferable because it tends to be a residual solvent during prepreg production coating. If the reaction rate due to the pre-reaction is less than 30 mol%, the resulting resin is not compatibilized, the resin is separated and clouded, and a B-stage coated fabric cannot be produced. On the other hand, if the reaction rate exceeds 70 mol%, the resulting thermosetting resin becomes insoluble in the solvent, making it impossible to produce an A-stage varnish (thermosetting resin composition), or the gel time of the prepreg becomes too short. In this case, the moldability may deteriorate. The iminocarbonate reaction is a reaction in which an iminocarbonate bond (—O— (C═NH) —O—) is generated by the addition reaction of a hydroxyl group and a cyanate group, and the triazine cyclization reaction has 3 cyanate groups. It is a reaction that quantifies to form a triazine ring. In addition, a three-dimensional network structure is formed by a reaction in which the cyanate group is trimerized to form a triazine ring. At this time, a compound having at least two epoxy groups per molecule (c) is formed in the three-dimensional network. A compatibilized resin in which the components (a), (b) and (c) are uniformly dispersed is produced by uniformly dispersing in the structure.

  Here, when the amount of use of (a) exceeds 10 parts by mass, low thermal expansion in the surface direction of the obtained substrate is obtained, and when the amount of use of (a) is less than 50 parts by mass, heat resistance is obtained. And chemical resistance does not decrease. When the use amount of (b) exceeds 40 parts by mass, the compatibility of the obtained resin is good, and when the use amount of (b) is less than 80 parts by mass, low heat in the surface direction of the obtained substrate is obtained. Good expandability. When the amount of (c) used exceeds 10 parts by mass, the moisture and heat resistance is good without decreasing, and when the amount of (c) used is less than 50 parts by mass, the copper foil adhesion and dielectric properties are improved. Good without deterioration. The amount of component (d) used in the reaction catalyst is preferably 0.0001 to 0.004 parts by mass with respect to 100 parts by mass as the sum of (a), (b) and (c). If it is 0.0001 part by mass or more, the reaction time is appropriate, and the desired reaction rate is easily reached. Further, when it is less than 0.004 parts by mass, anti-endpoint management is easy. Here, the reaction rate of the compound having the cyanate group (b) is determined by the GPC (gel permeation chromatography) measurement, the peak area of the compound having the cyanate group (b) at the start of the reaction, and the peak after the reaction for a predetermined time. The areas are compared, and the peak area disappearance rate is obtained.

  In the thermosetting resin used in the present embodiment, it is desirable to use an inorganic filler for the purpose of improving low thermal expansion, heat resistance, flame retardancy, etc., and it is particularly preferable to use fused silica. It is more preferable to use fused silica whose surface has been treated with a silane compound having the following. The silane compound having a functional group may be any silane compound having a functional group and an alkoxyl group, such as vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyl. Diethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane , 3-aminopropyl Triethoxysilane, N- phenyl-3-aminopropyltrimethoxysilane and the like. Among these, N-phenyl-3-aminopropyltrimethoxysilane represented by the following formula (IV) is particularly preferable.

  Examples of surface treatment methods for inorganic fillers include adding fused silica to ketone organic solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and alcohol organic solvents such as ethylene glycol monomethyl ether and propylene glycol monomethyl ether. After mixing, the trimethoxysilane compound represented by the structural formula (IV) is added and reacted (surface treatment) at 60 ° C. to 120 ° C. with stirring for about 0.5 to 5 hours. Also, commercially available from Admatechs Co., Ltd., for example, trade names SC-2050KNK and SC-2050HNK manufactured by Admatechs Co., Ltd. are available. The amount of these fused silica used is preferably 10 to 300 parts by mass, more preferably 100 to 250 parts by mass, and more preferably 150 to 250 parts by mass with respect to 100 parts by mass of the resin composition in terms of solid content. It is particularly preferable to do this. If it is 10 parts by mass or more, the rigidity, heat resistance, and flame resistance of the substrate are sufficient, and if it is 300 parts by mass or less, chemical resistance such as moldability and plating solution resistance is improved. .

  In the thermosetting resin composition used in the present embodiment, the compound containing an imidazole structure in the molecular structure as the component (2) is, for example, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole 1 type (s) or 2 or more types can be mixed and used. Among these, from the viewpoint of heat resistance and storage stability, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole are preferable, and further 250 ° C or lower. In view of good curing reactivity at low temperature, 2-methylimidazole is more preferable. Moreover, 0.1-5 mass parts is preferable with respect to 100 mass parts of thermosetting resins for the compounding quantity of an imidazole compound. When the content is 0.1 parts by mass or more, good curability is obtained, and when the content is 5 parts by mass or less, good storage stability is obtained.

  For the thermosetting resin composition used in the present embodiment, other inorganic fillers may be used, for example, crushed silica, mica, talc, short glass fiber or fine powder, hollow glass, calcium carbonate, quartz powder. Among these, metal hydrates such as aluminum hydroxide and magnesium hydroxide are preferable from the viewpoint of low thermal expansion, high elasticity, heat resistance, and flame retardancy, and further, metal water. Among Japanese products, metal hydrates having a thermal decomposition temperature of 300 ° C. or higher, such as boehmite type aluminum hydroxide (AlOOH), or gibbsite type aluminum hydroxide (Al A compound in which the thermal decomposition temperature of (OH) 3) is adjusted to 300 ° C. or higher by heat treatment, magnesium hydroxide is more preferable, particularly inexpensive, and particularly high thermal decomposition at 350 ° C. or higher. And degrees, boehmite-type aluminum hydroxide having a high chemical resistance (AlOOH) is more preferable. The amount of these inorganic fillers used is preferably 10 to 200 parts by weight, more preferably 10 to 150 parts by weight, and more preferably 50 to 150 parts by weight with respect to 100 parts by weight of the resin composition in terms of solid content. It is particularly preferable that If it exceeds 10 parts by mass, the flame retardancy will be sufficient, and if it is less than 200 parts by mass, chemical resistance such as plating solution resistance and moldability will not be deteriorated, and it will be good.

  For the thermosetting resin used in the present embodiment, it is desirable to use a curing accelerator in order to improve heat resistance, flame retardancy, copper foil adhesion, etc., and examples of the curing accelerator include zinc naphthenate and naphthenic acid. Examples thereof include organometallic salts such as cobalt, tin octylate and cobalt octylate, imidazoles and derivatives thereof, tertiary amines and quaternary ammonium salts. If a curing accelerator is not used, heat resistance, flame retardancy, copper foil adhesion, etc. may be insufficient.

  The thermosetting resin used in this embodiment can optionally be used in combination with other flame retardants, such as halogen-containing flame retardants containing bromine or chlorine, metal hydroxides having a thermal decomposition temperature of less than 300 ° C., etc. Does not meet the purpose of the present invention. Other flame retardants used in combination include phosphoric flame retardants such as triphenyl phosphate, tricresyl phosphate, trisdichloropropyl phosphate, phosphoric ester compounds, phosphazenes, red phosphorus, antimony trioxide, zinc molybdate, etc. Examples include flame retardant aids. In particular, an inorganic flame retardant aid in which zinc molybdate is supported on an inorganic filler such as talc is particularly preferable because it significantly improves not only flame retardancy but also drill workability. The amount of zinc molybdate used is preferably 5 to 20 parts by mass with respect to 100 parts by mass of the compatibilizing resin of the present invention. When it is 5 parts by mass or more, flame retardancy and drilling workability are improved, and when it is less than 20 parts by mass, the gel time of the varnish does not become too short, and the moldability can be satisfied when the laminate is formed by pressing.

  In the present embodiment, known thermoplastic resins, elastomers, flame retardants, organic fillers and the like can be used in combination.

  Examples of the thermoplastic resin include tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, xylene resin, petroleum resin, and silicone resin.

  Examples of the elastomer include polybutadiene, acrylonitrile, epoxy-modified polybutadiene, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified acrylonitrile.

  Examples of organic fillers include organic powders such as silicone powder, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, and polyphenylene ether.

  In this embodiment, an ultraviolet absorber, an antioxidant, a photopolymerization initiator, a fluorescent whitening agent, an adhesion improver, and the like can be arbitrarily added to the resin composition, and is not particularly limited. Examples of these include UV absorbers such as benzotriazoles, antioxidants such as hindered phenols and styrenated phenols, photopolymerization initiators such as benzophenones, benzyl ketals, and thioxanthones, and fluorescence such as stilbene derivatives. Examples include brighteners, urea compounds such as urea silane, and adhesion improvers such as silane coupling agents.

  The prepreg of this embodiment is formed by impregnating or coating the base material with the above-described thermosetting resin composition. Hereinafter, the prepreg of this embodiment will be described in detail.

  The prepreg of this embodiment is formed by impregnating or coating the above-mentioned thermosetting resin composition on an organic fiber base material. The prepreg of the present embodiment can be produced by impregnating or coating the above-mentioned thermosetting resin composition on an organic fiber base material and semi-curing (B-stage) by heating or the like. Organic fiber base materials include aramid resins, aromatic polyether ketone resins, polyparaphenylene benzobisoxazole (PBO) resins, polyester resins, aromatic polyester resins, polyimide resins, ultrahigh molecular weight polyethylene and tetrafluoroethylene resins. Examples thereof include organic fiber base materials and mixtures thereof.

  These organic fiber base materials have shapes such as woven fabric, non-woven fabric, robink, chopped strand mat, and surfacing mat, but the material and shape are selected depending on the intended use and performance of the molded product, and are necessary. Thus, it is possible to combine a single material or two or more materials and shapes. The thickness of the base material is not particularly limited, and for example, a thickness of about 0.03 to 0.5 mm can be used, and the surface is treated with a silane coupling agent, corona treatment, plasma treatment, or the like. Or the thing which performed the fiber opening process mechanically is suitable from the surface of heat resistance, moisture resistance, and workability. After impregnating or coating the base material so that the amount of the resin composition attached to the base material is 20 to 90% by mass in terms of the resin content of the prepreg after drying, the temperature is usually 100 to 200 ° C. Can be heated and dried for 1 to 30 minutes and semi-cured (B-stage) to obtain the prepreg of this embodiment.

The laminate of this embodiment can be formed by laminate molding using the prepreg of this embodiment described above. The prepreg of this embodiment can be manufactured by, for example, laminating 1 to 20 sheets and laminating and forming with a configuration in which a metal foil such as copper and aluminum is disposed on one side or both sides thereof. The metal foil is not particularly limited as long as it is used for electrical insulating material applications. In addition, as the molding conditions, for example, a method of a laminated plate for an electrical insulating material and a multilayer plate can be applied. For example, a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine, etc. are used, and a temperature of 100 to 250 ° C. It can be molded in a range of ˜100 kg / cm ² and a heating time of 0.1 to 5 hours. Further, the prepreg of this embodiment and the inner layer wiring board can be combined and laminated to produce a multilayer board.

  Next, the present invention will be described in more detail with reference to the following examples, but these examples do not limit the present invention in any way.

(Production Example 1: Production of compatibilizing resin)
In a reaction vessel with a capacity of 3 liters, which can be heated and cooled, equipped with a thermometer, a stirrer, and a reflux condenser, bisphenol A type cyanate resin (manufactured by Lonza Japan Co., Ltd .; trade name Primaset BADCy): 600.0 g and the following formula (V) Siloxane resin (manufactured by Shin-Etsu Chemical Co., Ltd .; trade name X-22-1821, hydroxyl group equivalent; 1,600 g / eq): 200.0 g, biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation; product) Name YX-4000, epoxy equivalent; 186 g / eq): 200.0 g and toluene: 1000.0 g. Next, the temperature was raised to 120 ° C. with stirring, and after confirming that the resin solids had dissolved and became a uniform solution, 0.01 g of an 8% by mass mineral spirit solution of zinc naphthenate was added, and about 110 The reaction was carried out at 4 ° C. for 4 hours. Then, it cooled to room temperature and obtained the solution of compatibilizing resin (1-1). A small amount of this reaction solution was taken out and GPC measurement was performed under the following conditions. As a result, the peak area of the synthetic raw material bisphenol A type cyanate resin with an elution time of about 12.4 minutes was found to be the bisphenol A type at the start of the reaction. Compared with the peak area of the cyanate resin, the disappearance rate of the peak area was 68%. Moreover, the peak of the product of the thermosetting resin which appears in the vicinity of about 10.9 minutes and 8.0-10.0 minutes was confirmed. Further, the reaction solution taken out in a small amount is dropped into a mixed solvent of methanol and benzene (mixing mass ratio 1: 1) and reprecipitated to take out the purified solid, and FT-IR measurement (Fourier transform infrared) Spectrophotometric measurement), a peak near 1700 cm ⁻¹ due to the imino carbonate group, a strong peak near 1560 cm ⁻¹ due to the triazine ring, and a strong peak near 1380 cm ⁻¹ can be confirmed. Was confirmed to be manufactured.
[GPC measurement conditions]
Apparatus: Autosampler, manufactured by Tosoh Corporation, trade name: AS-8020
Oven, manufactured by JASCO Corporation, trade name: 860-CO
Pump, JASCO Corporation, trade name: 880-PU
Analyzer: JASCO Corporation, trade name: 870-UV
Column: manufactured by Tosoh Corporation, TSKgel-SuperHZ3000 and TSKgel-
SuperHZ2000 (both trade names ("TSKgel" is a registered trademark)) in series
Standard sample: Polystyrene developing solvent: Tetotehydrofuran Sample concentration: 10 mg / ml
Sample injection volume: 20 μl
Measurement temperature: 40 ° C
Pump flow rate: 0.5ml / min

(Production Example 2: Production of fused silica surface-treated (wet treatment) with a trimethoxysilane compound)
In a reaction vessel with a volume of 3 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a reflux condenser, fused silica (manufactured by Admatechs Co., Ltd .; trade name SO-25R): 700.0 g and propylene glycol monomethyl ether : 1000.0 g was mixed, and N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .; trade name KBM-573): 7.0 g was added with stirring. Next, the temperature was raised to 80 ° C., reacted at 80 ° C. for 1 hour to perform surface treatment of the fused silica (wet treatment), then cooled to room temperature, and surface treatment with N-phenyl-3-aminopropyltrimethoxysilane ( A wet-processed fused silica solution was obtained.

(Production Example 3: Production of thermosetting resin composition varnish)
Compatibilized resin obtained in Production Example 1, fused silica obtained in Production Example 2, 2-methylimidazole as a compound containing an imidazole structure in the molecular structure, a curing accelerator, and methyl ethyl ketone as a diluent solvent. The mixture was mixed at the blending ratio (parts by mass) shown in Table 1 to obtain a uniform varnish having a resin content of 60% by mass.

[Examples 1 to 3, Comparative Example 1]
Next, the glass cloth made of the organic fiber substrate shown in Table 2 and the S glass shown in Table 2 is impregnated with the solution of the thermosetting resin composition varnish, and dried by heating at 160 ° C. for 5 minutes. Thus, a prepreg having a resin content of 50% by mass was obtained. Subsequently, four prepregs are stacked to form a laminate, and an electrolytic copper foil having a wiring width of 18 μm is disposed on one surface and the other surface of the laminate, under the conditions of a pressure of 2.5 MPa and a temperature of 240 ° C. A copper clad laminate was obtained by pressure bonding for 60 minutes. Using the copper-clad laminate thus obtained, the linear thermal expansion coefficient was measured and evaluated by the following method, and the evaluation results are shown in Table 2.

[Measurement of linear thermal expansion coefficient]
A 4 mm × 30 mm evaluation board from which the copper foil was removed by immersing the copper clad laminate in a copper etching solution was prepared, and a TMA test apparatus (thermomechanical test apparatus, manufactured by TA Instruments, TMA Q400) was used. The linear thermal expansion coefficient of 30 ° C. to 100 ° C. in the plane direction of the evaluation substrate was measured in the tensile mode. The heating rate was 10 ° C./min.

  From comparison between Examples 1 to 3 and Comparative Example 1 in Table 2, a siloxane resin containing a hydroxyl group, (b) a compound having at least two cyanate groups in one molecule, and (c) at least in one molecule A compatibilizing resin obtained by subjecting a compound having two epoxy groups and (d) an organometallic salt as a reaction catalyst to an imino carbonate reaction and a triazine cyclization reaction in an aromatic organic solvent, and a molecule It can be seen that by using a thermosetting resin composition containing a compound containing an imidazole structure in the structure and using an organic fiber base material for the prepreg, a lower thermal expansion coefficient can be exhibited than a prepreg using a conventional glass cloth.

  The prepreg obtained by impregnating or coating the organic fiber base material with the thermosetting resin composition according to the present invention, and the copper-clad laminate produced by laminating the prepreg exhibit low thermal expansion characteristics. It is useful for printed wiring boards for electronic equipment.

Claims (4)

A prepreg obtained by impregnating or coating a thermosetting resin composition on an organic fiber substrate, the thermosetting resin composition comprising:
A siloxane resin (a) having a hydroxyl group at the terminal represented by the following general formula (I), a compound (b) having at least two cyanate groups in one molecule, and at least two epoxy groups in one molecule The amount of (a) used per 100 parts by mass of the total of (a), (b), and (c) is 10 to 50 parts by mass of the compound (c) having the organic metal salt (d) as a reaction catalyst The amount of (b) used is in the range of 40 to 80 parts by mass, the amount of (c) used is in the range of 10 to 50 parts by mass, and these are 80 ° C. in a solvent previously selected from toluene, xylene and mesitylene. Manufactured by performing an imino carbonate reaction and a triazine cyclization reaction at a reaction temperature of ˜120 ° C., and pre-reacting so that the reaction rate (disappearance rate) of the compound having a cyanate group in (b) is 30 to 70 mol%. The That compatible resin,
And a prepreg which is a thermosetting resin composition comprising a compound containing an imidazole structure in the molecular structure.

  The organic fibers constituting the organic fiber base material are aramid resin, aromatic polyether ketone resin, polyparaphenylene benzobisoxazole (PBO) resin, polyester resin, aromatic polyester resin, polyimide resin, ultrahigh molecular weight polyethylene and tetra The prepreg according to claim 1, wherein the prepreg is a substrate composed of at least one resin selected from the group consisting of fluoroethylene resins.   The prepreg according to claim 1 or 2, wherein the organic fiber substrate is surface-treated by any one of a silane coupling agent, a corona treatment and a plasma treatment.   The laminated board obtained by shape | molding the prepreg in any one of Claims 1-3.