JPS61235436A - Production of laminate - Google Patents

Abstract

PURPOSE:To obtain a laminate excellent in workability, heat resistance, adhesiveness and electrical properties, by infiltrating a specified curable resin composition into glass or quartz cloth to form prepregs and laminate-molding these prepregs. CONSTITUTION:The following curable resin composition is infiltrated into glass or quartz woven or nonwoven cloth to form B-stage prepregs and these prepregs are laminate-molded together with, if necessary, metal foil to obtain the title laminate. Said composition is a curable resin composition comprising 60-95wt% thermosetting resin composition [A] which, when cured, has a dielectric constant of 4.0 or below (at 1MHz and 25 deg.C) and 40-5wt% copolymer [B], m.p. >=10 deg.C, obtained by introducing at least 0.5, per molecule, at last one functional group selected from among hydroxyl, carboxyl, acid anhydride, epoxy, mercapto and amino groups to a copolymer obtained by copolymerizing butadiene with a vinyl aromatic compound and having a 1,2-bond content of the butadiene units constituting the polymer chains, >=50%.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing a laminate with excellent electrical properties, etc., and in particular to a molded body for printed wiring with a low dielectric constant and a low dielectric loss tangent. It is suitably used in the production of structural laminates, etc.

[Conventional methods and their problems]

The dielectric properties of conventional thermosetting resin metal foil-clad laminates are insufficient for printed boards for high-speed arithmetic circuits and high-frequency circuits, and tetrafluoroethylene resins have mainly been used. However, this fluororesin laminate is expensive and has problems in adhesion to metal foil, dimensional stability, plating adhesion, etc.

On the other hand, although polybutadiene resin has a low dielectric constant,
It is liquid at room temperature, making it difficult to make a dry prepreg, and its adhesion is insufficient.

Furthermore, methods using compositions of thermosetting resins and polybutadiene resins have been attempted, but these have had problems such as workability and solubility.

[Means for solving problems]

As a result of intensive studies to improve the drawbacks of the conventional methods as described above, the present inventors found that by using a thermosetting resin composition having specific physical properties, specific butadiene, and a vinyl aromatic compound, A laminate with excellent workability, heat resistance, adhesive properties, electrical properties, etc. was discovered, and the present invention was completed.

That is, in the present invention, the dielectric constant of the cured resin is 4.0 (at
1 MHz, 25°C) or less [
A] A copolymer in which 50% or more of the butadiene units constituting the polymer chain formed by polymerization of 60 to 95% by weight and a vinyl aromatic compound are 1,2-bonds, a hydroxyl group, a carboxyl group, Obtained by introducing 0.5 or more functional groups per molecule of one or more types selected from the group consisting of acid anhydride groups, epoxy groups, mercapto groups and amino groups,
Prepare a B-stage prepreg by impregnating glass or quartz woven or nonwoven fabric with a curable resin composition consisting of 40 to 5% copolymer [B] having a melting point of 10°C or higher. This is a method for producing a laminate, which is characterized in that the thermosetting resin composition [A] is formed by laminating and molding the laminate with a metal foil if necessary, and preferable thermosetting resin compositions [A] include epoxy resin,
One or a mixture of two or more selected from the group consisting of diallyl phthalate resin, polymaleimide resin, and polyisocyanate resin is used.

The present invention will be explained below.

Component [A] of the present invention has a dielectric constant of 4.0 (IM
IIz, 25°C) or less.

As a thermosetting resin composition that satisfies such physical properties,
It is usually selected from the group consisting of epoxy resins, diallyl phthalate resins, polymaleimide resins, polyisocyanate resins, and mixtures of one or more of these.

To explain these more specifically, epoxy resins include bisphenol A epoxy resin, bisphenol F epoxy resin, halogenated bisphenol A epoxy resin, phenol novolank epoxy resin, cresol novolak epoxy resin, and halogenated phenol Novolac type epoxy resins and mixtures of two or more of these with melting points of 10°C or higher; In addition, modified epoxy resins such as isocyanurate/oxazolidone resins manufactured from two components of polyfunctional isocyanate and epoxy resin, and polyfunctional Examples include a resin manufactured from maleimide and an epoxy resin, a resin manufactured from 1,2-polybutadiene and its modified resin, and an epoxy resin. When using these epoxy resins, curing accelerators include amines such as diethylenetriamine and diaminodiphenylmethane; acid anhydrides such as hexahydrophthalic anhydride and methylhexahydrophthalic anhydride; 2-ethylimidazole, etc. Examples include known imidazoles.

Examples of diallyl phthalate resins include diallyl orthophthalate and prepolymer/monomer mixtures of diallyl isophthalate, and examples of curing accelerators include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, octanoyl peroxide, and lauroyl peroxide. Diacyl peroxides such as oxide; di-tert-butyl peroxide, 2゜5-dimethyl-2,5-di(t-
butyl peroxide) hexyne-3, dialkyl peroxide 11 such as dicumyl peroxide; ter
tert-butyl perbenzoate, tert-butyl peracetate, di-tert-butyl perphthalate, 2
．． 5-dimethyl-2,5-di(benzoylperoxy)
Peroxy esters such as hexane; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; di-tert-butyl hydroperoxide, cumene hydroperoxide, α-phenylethyl hydroperoxide, cyclohexenyl hydroperoxide Hydroperoxides such as oxide; l, 1-bis(tert-butylperoxy)cyclohexane, 1. Examples include organic peroxides such as peroxyketals such as l-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane.

As the polymaleimide resin, a composition having a molar ratio of maleimide compound and jepoxy compound of 1:0.2 to 0.5 as described in Japanese Patent Publication No. 48-8279,
The equivalent ratio of maleimide compound and alkenylphenol or alkenylphenol ether as described in JP-A-54-101200 is 1:0.2 to 1.
．． 5, a composition of a maleimide compound and 1,2-polybutadiene as described in JP-A-55-126451, and examples of curing accelerators include the above-mentioned amines and organic peroxides. Preferably.

Furthermore, as a polyisocyanate resin, JP-A-55-
Known compositions such as a composition comprising an epoxy resin, a polyfunctional isocyanate compound, and a heterocycle-forming catalyst as described in Japanese Patent No. 75418 may be mentioned.

Next, the copolymer [B] of the present invention is obtained by polymerizing butadiene and a vinyl aromatic compound and introducing a functional group, and usually the butadiene and vinyl aromatic compound are mixed by weight 80: 20-10:90, preferably 70:30-
20:80, and 50% or more, preferably 85% or more of the butadiene units constituting the polymer chain are 1.2
- obtain a block or random copolymer which is a bond;
Next, the reaction solution of the copolymer is treated with a functional group-introducing reagent, either as it is or after the reaction has been stopped, to obtain hydroxyl groups,
One or more functional groups selected from the group consisting of a carboxyl group, an acid anhydride group, an epoxy group, a mercapto group, and an amino group are introduced per molecule on average of 0.5 or more, preferably 1 to 4. The melting point is 10°C or higher, preferably 20°C or higher.

Here, as the aromatic vinyl compound, styrene, α-
Methylstyrene, vinyltoluene, chlorostyrene, P
-Ethylstyrene, P-methoxystyrene, divinylbenzene, etc. are exemplified.

The copolymer can be polymerized by anionic polymerization using a nonpolar hydrocarbon solvent at a temperature of 0 to 70°C using an alkali metal as a catalyst. % or more can be done,
Although this method may be used, in particular, in the application of the present invention, a Lewis compound such as tetrahydrofuran is used in the presence or absence of a polycyclic or polynuclear aromatic hydrocarbon activator such as naphthalene, anthracene, biphenyl, or 1,2-diphenylbenzene. A system obtained by dispersing a basic compound and an alkali metal such as sodium or lithium was heated at a temperature of -20°C.
According to the method of anionic living polymerization by adding butadiene and a vinyl aromatic compound simultaneously or sequentially at a temperature below ℃, the amount of L2- bonds in the butadiene unit is
It is easy and preferable to set it to 0% or more, and 85 to 95% depending on the conditions. Furthermore, this method is preferable because it makes it easy to adjust the molecular weight.

The introduction of functional groups can be achieved by treating the polymerization reaction solution obtained by this method with reagents such as tJ, ethylene oxide, ethylene sulfide, and ethylene imine, and then treating with water and methanol to form both polymer chains. A butadiene-vinyl aromatic compound copolymer having a functional group such as a carboxyl group, a hydroxyl group, a mercapto group, or an amino group at the terminal end is obtained, and if the polymerization reaction solution is immediately treated with epichlorohydrin, the polymer chain has A butadiene-vinyl aromatic compound copolymer having epoxy groups is obtained.

In addition, if the polymerization reaction solution obtained by the above method is immediately treated with water and methanol, a butadiene-vinyl aromatic compound copolymer having no functional groups can be obtained. Maleic anhydride, methyl maleic anhydride, etc.
By heating and mixing with an α/β-dicarboxy compound at 140 to 230°C, a butadiene-vinyl aromatic compound copolymer with an acid anhydride group introduced into a part of the polymer chain can be obtained. If a butadiene-vinyl aromatic compound copolymer with or without a functional group at the terminal end is treated with air or oxygen at 100 to 150°C in the presence of a catalyst and a solvent, carboxyl groups, A butadiene-vinyl aromatic compound copolymer into which a hydroxyl group has been introduced is obtained, and a butadiene-vinyl aromatic compound copolymer having no functional group is mixed with peracetic acid and perbrobionic acid at 40 to 100°C in the presence of a solvent. By treatment with such an organic peracid, a butadiene-vinyl aromatic compound copolymer in which epoxy groups are introduced into some of the double bonds of butadiene in the polymer chain can be obtained.

If the amount of the butadiene component in the copolymer CB) of the present invention prepared by the above method exceeds 80% by weight, the compatibility with the thermosetting resin composition of component [A] will deteriorate, which is not preferable. On the other hand, if it is less than 10% by weight, the heat resistance of the cured product will deteriorate, so it is not preferable.
If the bonding unit content is less than 50%, the heat resistance of the cured product will deteriorate, which is not preferable. Furthermore, the number average molecular weight of the copolymer [B] is 500 to 10,000, particularly 1,000.
0 to 5.000 is preferable, and the melting point is preferably 10°C or higher, preferably 20°C or higher. If the melting point is lower than 10°C, the composition becomes sticky and workability deteriorates. In addition, as the functional group, hydroxyl group, carboxyl group, and epoxy group are particularly preferable, and although it depends on the number average molecular weight, it is usually 0.5 per molecule.
The number is preferably 1 to 4, taking into account the compatibility of the [A] component and the [B] acid component, electrical properties, etc.

The above thermosetting resin composition [A] and a specific butadiene-vinyl aromatic compound copolymer CB) are mixed or preliminarily reacted to prepare a curable resin composition to be used in the prepreg for laminated molding of the present invention. do.

Preparation methods include mixing under heating without a solvent; heating preliminary reaction without a solvent; mixing as a solution or colloidal solution of a solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, etc. Any of the following methods are possible: a method in which a solution of the solvent is mixed and pre-reacted; a method in which a pre-reacted solution of the solvent is mixed.

The composition ratio of component [A] and CB) is not particularly limited, but is usually preferably in the range of 9515 to 60/40.

If component [A] is less than 60% by weight, the thermosetting properties will be lowered, and if it exceeds 95% by weight, the improvement in dielectric properties will be insufficient.

The thermosetting resin composition used in the present invention consists of the above two components as essential components, but in addition to these, modifying resins and known additives may be added in such a way that the properties of the composition are impaired. It can be added within the range.

These include the viscous behavior of the composition, adhesion, curability,
Resins for the purpose of improving flexibility, such as thermosetting resins such as polyester resins, phenol resins, acrylic resins, and urethane resins; polybutadiene and butadiene.
Liquid to elastic rubbers such as acrylonitrile copolymer, polychloroprene, butadiene-styrene copolymer, polyisoprene, butyl rubber, natural rubber, etc., and their low molecular weight products with a molecular weight of several thousand or less; thermoplastic polyurethane resin, vinyl acetate Resins and other thermoplastic resins with reactive groups and their low molecular weight products with a molecular weight of several thousand or less; Engineering plastics with a molecular weight of several thousand or less such as polycarbonate, thermoplastic polyester, polyester carbonate, polyarylate, polyphenylene ether, etc. Molecular weight oligomer; polyethylene,
Low molecular weight oligomers of polyolefins such as polypropylene and 4-methylpentene-1 with a molecular weight of several thousand or less;
Resins such as low molecular weight oligomers with a molecular weight of several thousand or less of fluorine resins such as polytetrafluoroethylene, polytetrafluoroethylene-propylene copolymer, perfluoroethylene propylene copolymer; Inorganic fillers - e.g. For applications with low dielectric constant and dielectric loss tangent, silica powder such as fused silica and crystalline silica, boron nitride powder, and boron silicate powder are used.For applications with high thermal conductivity, in addition to the above, alumina, Inorganic fillers such as magnesium oxide (magnesia), wollastonite, mica, calcium carbonate, and talc are suitable for other purposes. These inorganic fillers may be used as they are, or may be surface-treated with a silane coupling agent, titanate coupling agent, etc.
Used as particulate or fibrous filler.

Furthermore, it is a preferable embodiment to improve the processability, flexibility, etc. of the molded article by replacing some of the above-mentioned inorganic fillers with organic fillers. are polycarbonate, thermoplastic polyester, polyester carbonate, polyarylate,
High molecular weight powder of engineering plastics such as polyphenylene ether; High molecular weight powder of polyolefin such as polyethylene, polypropylene, poly-4-methyl-1-pentene; polytetrafluoroethylene, polytetrafluoroethylene-propylene copolymer Union,
Examples include powder of fluororesin such as perfluoroethylene propylene copolymer.

The thermosetting resin composition described above is impregnated or applied to a reinforcing base material, which is a woven or nonwoven fabric of glass or quartz, using a known method, and dried as necessary to prepare the prepreg of the present invention. do. These reinforcing base materials are preferably treated with a surface treatment agent such as a silane coupling agent or a titanate coupling agent, like ordinary reinforcing base materials for laminated molding.

One or more sheets of prepreg obtained by the above method are used, and if necessary, metal foil such as electrolytic copper foil is layered, and the molding pressure is usually 3 to 100 kg/d and the temperature is 160 kg/d.
The laminate of the present invention is formed by heating and pressurizing at ~240°C. Note that the molding time is selected within the range of 30 seconds to 30 hours. Depending on the resin component, 30 seconds to 10
In the case of a relatively short time in the range of 0 minutes or in the case of using a low temperature, by post-curing in an oven after lamination molding,
It is preferable to form a molded article that is sufficiently cured.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples. In addition, parts and percentages in the examples are based on weight unless otherwise specified.

Reference Example-1 A polymer produced by adding 50 parts of butadiene and then 50 parts of α-methylstyrene at -60°C to a system in which a sodium dispersion was added to tetrahydrofuran in which 1,2-diphenylbenzene was dissolved. - The reaction mixture was treated with epichlorohydrin to give a number average molecular weight of 2,100, butadiene units of 49.8%, and α-methylstyrene units of 50.
2%, 1.2-bond in the butadiene unit 90.5%, 1
．． A butadiene-α/methylstyrene block copolymer having a 4-bond of 9.5%, an epoxy equivalent of 1250, and a melting point of 62°C was obtained.

Reference Example 2 Butadiene 4 was added to a system in which a sodium dispersion was added to tetrahydrofuran in which naphthalene was dissolved at -60°C.
A polymerization reaction solution produced by adding a mixture of 0 parts and 60 parts of styrene was treated with ethylene oxide, and then hydrolyzed.
Number average molecular weight 2,520, butadiene unit 39.8%,
60.2% styrene units, 1.2- in butadiene units
Bond 91.3%, 1.4-bond 8.7%, hydroxyl value 4
0.1, a butadiene-styrene random copolymer having a melting point of 66°C was obtained.

Reference Example 3 Butadiene 4 was added to a system in which a sodium dispersion was added to tetrahydrofuran in which biphenyl was dissolved at -60°C.
The polymerization reaction solution produced by adding 0 parts of α-methylstyrene and then adding 60 parts of α-methylstyrene was treated with propylene oxide and then hydrolyzed to give a number average molecular weight of 3,480, butadiene units of 39.1%, α - 60.9% methylstyrene units,
1,2-bond in butadiene unit 89.4%, 1,4-
A butadiene-α/methylstyrene block copolymer having a bond of 10.6%, a hydroxyl value of 28.9, and a melting point of 75°C was obtained.

Example-1 Bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy ■, trade name: Epicote 1001, epoxy equivalent: 45
0 to 500, melting point 68°C) 70 parts, butadiene-α/methylstyrene block copolymer 3 prepared in Reference Example-1
0 parts, and 8 parts of dicyandiamide and 0.05 parts of benzyldimethylamine as catalysts were mixed with methyl ethyl ketone (hereinafter referred to as MEK) and dimethylformamide (hereinafter referred to as DM).
It was dissolved in a mixed solvent of (denoted as F) to make a solution with a concentration of 50%.

This solution was impregnated into a flat glass woven fabric with a thickness of 0.2111 and dried at 140°C for 7 minutes.
-stage prepreg.

8 sheets of this prepreg were stacked and electrolytic copper foil with a thickness of 35 cm was layered on both sides, and the temperature was 175℃ and the pressure was 35kg/c+J.
Lamination molding was performed for minutes to obtain a copper-clad laminate.

The properties of this copper-clad laminate are shown in Table 1.

Comparative Example-1 Butadiene prepared in Reference Example-1 in Example-1
A copper-clad laminate was obtained in the same manner except that the α-methylstyrene block copolymer was not used.

The properties of this copper-clad laminate are shown in Table 1.

Example-2 78 parts of diallyl phthalate prepolymer with a softening temperature of 80°C and an iodine value of 58, 8 parts of diallyl phthalate, Reference example-
Butadiene-styrene random copolymer 2 prepared in 2
0 parts, and 2 parts of tert-butylperoxybenzoate as a catalyst were added and dissolved in MEK to form a solution with a concentration of 50%.

This solution was impregnated into a plain-woven E glass woven fabric with a thickness of 0.2 mm.
B-sta with no flattening after drying at 10℃ for 5 minutes
ge prepreg.

Eight sheets of this prepreg were stacked on both sides with electrolytic copper foil having a thickness of 35 haze, and laminated and molded at a temperature of 160°C and a pressure of 30 kg/- for 120 minutes to obtain a copper-clad laminate.

The properties of this copper-clad laminate are shown in Table 1.

Comparative Example-2 A copper-clad laminate was obtained in the same manner as in Example-2 except that the butadiene-styrene random copolymer prepared in Reference Example-2 was not used.

The properties of this copper-clad laminate are shown in Table 1.

Example-3 30 parts of bis(4-maleimidophenyl)methane and 70 parts of the same bisphenol A epoxy resin used in Example-1 were mixed at 120°C for 30 minutes to form a prepolymer, which was then cooled to room temperature. .

To this prepolymer, 40 parts of the butadiene-α/methylstyrene block copolymer prepared in Reference Example-3 was added,
MEK was mixed, and further 5 parts of diaminodiphenylmethane and 0.5 parts of dicumyl peroxide were mixed as catalysts to form a colloidal solution.

This solution was impregnated into a 0.2 mm thick quartz fabric and dried at 150° C. for 6 minutes to obtain a B-stage prepreg with no stickiness.

8 sheets of this prepreg were stacked and electrolytic copper foil with a thickness of 35 layers was layered on both sides, and the temperature was 180℃ and the pressure was 40ksr/c+1.
After lamination molding for 0 minutes, the product was post-cured for 4 hours in a constant temperature bath at 240°C to obtain a copper-clad laminate.

The properties of this copper-clad laminate are shown in Table 1.

Comparative Example 3 A copper-clad laminate was obtained in the same manner as in Example 3, except that the butadiene-α/methylstyrene block copolymer prepared in Reference Example 3 was not used.

The properties of this slightly stretched laminate are shown in Table 1.

Comparative Example 4 In Example 3, a prepreg was prepared in the same manner except that 40 parts of 1,2-polybutadiene having a molecular weight of 2,000 was used instead of the butadiene-α/methylstyrene block copolymer prepared in Reference Example 3. An attempt was made to prepare The solution is
It phase-separates easily, requires impregnation while stirring, and furthermore, it is impossible to obtain a prepreg without "stickiness", making it unsuitable for use as a prepreg for laminated molding.

Example 4 After adding and mixing 30 parts of fused silica powder to the colloidal solution obtained in the same manner as in Example 3, the solution was impregnated into a glass nonwoven fabric with a thickness of 0.3 mm, and heated at 150°C.
It was dried for 6 minutes to obtain a B-stage prepreg with no stickiness.

Four sheets of this prepreg were stacked, one sheet of prepreg obtained in the same manner as in Example-3 was placed on both sides, and the thickness was further increased to 35I.
Layer na electrolytic copper foil one by one at a temperature of 180°C and a pressure of 4.
After lamination molding at 0 kg/aJ for 120 minutes, the product was cured for 4 hours in a constant temperature bath at 240° C. to obtain a copper-clad laminate.

The properties of this copper-clad laminate are shown in Table 1.

Example 5 30 parts of bis(4-maleimidophenyl)methane, 30 parts of the same bisphenol A epoxy resin used in Example 1, brominated bisphenol A epoxy resin (
Made of Yuka shell epoxy ■, product name: Epicoat 1045
, epoxy equivalent 450-500°, melting point 68°C) 30
and 50 parts of diphenylmethane diisocyanate (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name, MDI-CR) were dissolved in DMF.

To this solution, add 30 parts of the butadiene-α/methylstyrene block copolymer prepared in Reference Example-3 and 2 parts as a catalyst.
-0.1 part of -ethyl-4-methylimidazole and 1 part of dicumyl peroxide were dissolved and mixed. Add this solution to a 0.2fl thick S glass woven fabric (5i (h 65%, Al
A low dielectric constant glass woven fabric containing 25% of 2O3 and about 10% of l'1go was impregnated and dried at 150° C. for 7 minutes to produce a B-stage prepreg without stickiness.

Eight sheets of this prepreg were stacked one by one with 35 InA electrolytic copper foil on both sides at a temperature of 200°C and a pressure of 40 kg/cm.
- for 240 minutes to obtain a copper-clad laminate.

The properties of this m-stretch laminate are shown in Table 1.

Comparative Example-5 Butadiene prepared in Reference Example-3 in Example-5
A copper-clad laminate was obtained in the same manner except that the α-methylstyrene block copolymer was not used.

The properties of this copper-clad laminate are shown in Table 1.

Table 1 (Functions and Effects of the Invention) The method for producing a laminate of the present invention as described above improves the solubility of the cured resin composition used in general-purpose low-boiling solvents, and improves the working environment and dryness. Others are very easily B-sta
Ge-containing prepreg is obtained, and the prepreg has virtually no tackiness, has excellent handling and workability, and has excellent electrical properties (especially low dielectric constant, dielectric loss tangent), adhesive properties, etc. of the obtained cured product. It is possible to obtain a laminate exhibiting the following properties, which is highly practical.

Patent applicant Mitsubishi Gas Chemical Co., Ltd. Nihon Raidatsu Co., Ltd.

Claims (1)

[Claims] 1. The dielectric constant of the cured resin is 4.0 (at 1 MHz, 25°C
) 60 to 95% by weight of the thermosetting resin composition [A] below, and 50% or more of the butadiene units constituting the polymer chain formed by polymerizing butadiene and a vinyl aromatic compound.
, 2-bond copolymer has at least 0.5 or more functional groups selected from the group consisting of hydroxyl group, carboxyl group, acid anhydride group, epoxy group, mercapto group, and amino group per molecule. A curable resin composition consisting of 40 to 5% by weight of a copolymer [B] obtained by introducing the copolymer [B] and having a melting point of 10°C or higher is impregnated into a woven or nonwoven fabric of glass or quartz to obtain B- A method for manufacturing a laminate, which comprises preparing a stage prepreg and layering it with metal foil as necessary to form a laminate. 2. Claim 1, wherein the thermosetting resin composition [A] is one or a mixture of two or more selected from the group consisting of epoxy resin, diallyl phthalate resin, polymaleimide resin, and polyisocyanate resin. manufacturing method.