JPH0551434A - Epoxy resin composition and method for producing laminated board - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a uniformly transparent epoxy resin composition. [Structure] Bisphenol A diglycidyl ether type epoxy resin, tetrabromobisphenol A diglycidyl ether type epoxy resin, methylhexahydrophthalic anhydride, dimethacrylate of bisphenol A diglycidyl ether type epoxy resin, styrene, and benzoyl A peroxide and a curing accelerator, tetraphenylboron-2-ethyl-4-methylimidazole, are mixed to prepare an epoxy resin composition. A laminated board is manufactured using this epoxy resin composition. [Effect] A composition that is uniformly transparent and has good stability can be obtained.
When it is used in the production of a laminated plate, the fiber substrate can be impregnated for a long time, and the finally obtained laminated plate also has excellent physical properties.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a specific solventless epoxy resin composition having a small increase in viscosity at room temperature, and a method for producing a laminated board using the resin composition. .

[0002]

2. Description of the Related Art A glass epoxy resin-based laminate used as a printed circuit board is manufactured by heating and pressurizing after passing through a B-staged prepreg.
It is known that a polybasic acid anhydride having excellent heat resistance and electrical characteristics is used as an epoxy resin curing agent.

Since the above heat and pressure molding requires a long time and has a problem in productivity, a resin having a polymerizable unsaturated group and a polymerization initiator are added to an epoxy resin and a curing agent for an epoxy resin. There is known a prepreg manufacturing method (JP-A-62-285929) in which moldability is improved by a resin composition.

However, the composition described in the above publication has a drawback that the viscosity increases with time at room temperature, and as a composition that solves this problem, amine compounds which have been subjected to a specific treatment, so-called microcapsules. There has been proposed a method for producing a laminated plate using a composition to which is added as a curing accelerator (JP-A-1-261430).

Generally, this kind of microcapsule type curing accelerator is stable at room temperature because it is difficult to dissolve in organic substances.

[0006]

A method for producing a laminated sheet using a composition containing a microcapsule type curing accelerator is suitable as a method for producing a laminated sheet having a small increase in viscosity of the composition and excellent in impregnation workability. However, since it is insoluble in the composition and is a dispersion system, it has a drawback that a defective impregnation site is likely to occur in the laminate of the final cured product.

[0007]

In view of such circumstances, the present inventor comprises a solventless liquid epoxy resin, a polybasic acid anhydride, an epoxy vinyl ester resin and / or an unsaturated polyester resin, and a polymerization initiator. As a result of earnest research on a curing accelerator that dissolves uniformly in a solventless epoxy resin composition, by using a tetraphenylboron compound as a curing accelerator, the composition is uniformly transparent, and the viscosity increase at around room temperature is small. It became possible to perform impregnation work for a long time. Moreover, it was found that a laminated board obtained by using this composition has almost no impregnated defective portion, and that a laminated board excellent in water absorption rate and solder heat resistance can be obtained, thereby completing the present invention.

That is, the present invention is a solventless liquid epoxy resin (A), a polybasic acid anhydride (B), an epoxy vinyl ester resin and / or an unsaturated polyester resin (C).
And an epoxy resin composition (I) containing a polymerization initiator (D) and a tetraphenylboron compound (E) as essential components, and a fibrous base material (II) impregnated with the epoxy resin composition (I). The present invention provides a method for producing a laminated plate, which comprises obtaining a base material (III) and then thermoforming it.

As the epoxy resin (A) used in the present invention, either a solventless liquid epoxy resin at room temperature or a mixture thereof can be used, but a solid epoxy resin can also be used in combination. Usually the average epoxy equivalent is 100-40
0, preferably 100-250 is used. Typical examples thereof include epoxy resins obtained from epichlorohydrin and dihydric phenols such as bisphenol A, bisphenol F, tetrabromobisphenol A, tetrabromobisphenol F and resorcin: polyglycidyl ethers of phenol or alkylphenol / novolak resin: ethylene Polyglycidyl ethers of polyhydric alcohols such as glycol, propylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane or bisphenol A ethylene oxide or propylene oxide adducts: adipic acid, Polyglycidyl esters of polycarboxylic acids such as phthalic acid, hexahydrophthalic acid or dimer acid; Cyclohexene-based epoxy compounds obtained by epoxidizing clohexene or a derivative thereof with peracetic acid (3,4-epoxy-6-methyl-cyclohexyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 3,4 4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 1-epoxyethyl-3,4-epoxycyclohexane, etc.), cyclopentadiene or dicyclopentadiene or a derivative thereof by epoxidation with peracetic acid or the like. Cyclopentadiene-based epoxy compounds (cyclopentadiene oxide, dicyclopentadiene oxide, 2,3-epoxycyclopentyl ether, etc.), limonene dioxide or hydroxybenzoate There are glycidyl ether esters of acids, etc. Among them, solvent-free liquid epoxy resin obtained from epichlorohydrin and bisphenol A is good because of good balance of performance and low price, and low viscosity of solvent-free liquid epoxy resin. Cyclohexene epoxy compounds are preferred.

Next, examples of the polybasic acid anhydride (B) used in the present invention include phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and nadic anhydride. Acid, methyl nadic acid anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, succinic anhydride, itaconic anhydride, citraconic anhydride, dodecenyl succinic anhydride, chlorendic acid anhydride, benzophenone tetracarboxylic acid anhydride, Cyclopentatetracarboxylic anhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, ethylene glycol bis trimellitate anhydride or glycerin trimellitate anhydride, etc. , But these are alone Or used in the form of a mixing of two or more. Among them, liquid divalent carboxylic acid anhydrides such as methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylnadic nadic acid anhydride are preferable, and an epoxy resin composition having particularly excellent storage stability can be obtained. Phthalic anhydride is most preferred.

As the epoxy vinyl ester resin (C) used in the present invention, any of the known and conventional ones can be used. For example, the various epoxy resins described above as the epoxy resin, preferably a bisphenol type or novolak resin. Epoxy vinyl ester resins obtained by reacting each type of epoxy resin, alone or in mixture, with an unsaturated monobasic acid in the presence of an esterification catalyst are mentioned.

Typical examples of unsaturated monobasic acids are acrylic acid, methacrylic acid, cinnamic acid, crotonic acid, monomethylmaleate, monopropylmaleate,
Monobutylmalate, sorbic acid, mono (2-ethylhexyl) malate and the like can be used, and these can be used alone or in a mixture of two or more kinds.

The epoxy vinyl ester resin may be dissolved in a polymerizable vinyl monomer, if necessary. Typical of the polymerizable vinyl monomers, styrene, vinyltoluene, t-butylstyrene, chlorostyrene, or styrene such as divinylbenzene and derivatives thereof; 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, 2
-Hydroxyethyl (meth) acrylate, or 2
-Ester monomers of (meth) acrylic acid such as hydroxypropyl (meth) acrylate; or trimethylolpropane tri (meth) acrylate, diethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate or 1, Examples thereof include (meth) acrylates of polyhydric alcohols such as 6-hexanediol di (meth) acrylate, and these may be used alone or as a mixture of two or more kinds.

The polymerizable vinyl monomer is usually used in a proportion of 25 to 150 parts by weight per 100 parts by weight of the epoxy vinyl ester resin. As the unsaturated polyester resin (C) used in the present invention, any of the known and commonly used ones can be used. For example, an unsaturated polyester resin (C) obtained by reacting a dibasic acid containing an unsaturated dibasic acid with a polyhydric alcohol can be used. A saturated polyester resin may be used.

Representative examples of unsaturated dibasic acids include maleic acid, maleic anhydride, fumaric acid, halogenated maleic anhydride, and the like, and other representative acids as saturated dibasic acids. Examples include phthalic acid, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, succinic acid, adipic acid, sebacic acid, etc. Is ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, hydrogenated bisphenol A, 1,6-hexanediol, bisphenol A. Ethylene oxide or propylene oxide Adducts of the side, glycerin, trimethylolpropane and the like.

The unsaturated polyester resin may be dissolved in a polymerizable vinyl monomer, if necessary. Examples of the polymerizable vinyl monomer used here include the same polymerizable vinyl monomers as described above. These are used alone or as a mixture of two or more kinds, and the amount of the polymerizable vinyl monomer used is usually the unsaturated polyester resin 1
It is used in a proportion of 25 to 150 parts by weight per 00 parts by weight.

To obtain an epoxy vinyl ester resin or an unsaturated polyester resin using each of these raw materials,
A conventionally known method may be followed, and in preparing both of the resins constituting the resin (C) in the present invention, the purpose is to prevent gelation during resin preparation, storage stability of the produced resin, or It is recommended to use a polymerization inhibitor for the purpose of adjusting the curability.

Typical examples of such a polymerization inhibitor include hydroquinone, pt-butylcatechol,
Hydroquinones such as mono-t-butyl hydroquinone; hydroquinone monomethyl ether, di-t-p-
Phenols such as cresol; quinones such as p-benzoquinone, naphthoquinone and toluquinone; copper salts such as copper naphthenate; N-nitrosohydroxylamine derivatives and the like.

Examples of the polymerization initiator (D) used in the present invention include cyclohexanone peroxide, 3,3,3.
5-trimethylcyclohexanone peroxide, methylonexanone peroxide, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, cumene hydroperoxide, dicumyl peroxide, lauroyl peroxide, 3 , 5,5-trimethylhexanoyl peroxide, benzoyl peroxide, di-myristyl peroxydicarbonate,
t-butylperoxy (2-ethylhexanoate),
Organic peroxides such as t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxybenzoate and cumylperoxyoctoate can be mentioned.

In the present invention, the tetraphenylboron compound (E), which is the most prominent feature of the curing accelerator, is
Can be any of known and commonly used compounds. For example, in the general formula, (R ₁ ) ₄ B · R ₂ (wherein R ₁ represents a phenyl group or a substituted phenyl group, R ₂ represents a metal, amines Means).

Specifically, for example, tetraphenylboron-sodium or other tetraphenylboron-metals, tetraphenylboron-imidazole, tetraphenylboron-triethanolamine, tetraphenylboron-
1,8-diaza-bicyclo (5,4,0) undecene-
7 etc. Tetraphenylboron / amine salt, tetraphenylboron / tetraphenylphosphonium, etc.

The solventless epoxy resin composition (I) used in the present invention uses each of the components (A) to (E) as an essential component, and further contains an internal release agent, a pigment and a filler, if necessary. It can be easily prepared by adding additives such as. When these additives are added, it is preferable to prepare the composition so that the fibrous base material (II) can be impregnated.

The weight ratio of the total of the components (A) and (B) to the component (C) in the solventless epoxy resin composition (I) is not particularly limited, but (A)
+ (B) is usually 5 to 235 per 100 parts by weight of (B).
However, 10 to 100 is preferable in that the curing shrinkage is small and the adhesiveness to metal, particularly copper foil or fibrous base material, especially glass fiber, and the moldability are excellent.

The amount of the polymerization initiator (D) added is usually 0.1 to 3 parts by weight, preferably 0.5 to 100 parts by weight of the epoxy vinyl ester resin and / or unsaturated polyester resin (C). ~ 3 parts by weight.

Further, the addition amount of the tetraphenylboron compound (E) which is the curing accelerator of the present invention is usually 0.1 to 10 parts by weight, preferably 100 parts by weight of the polybasic acid anhydride (B). 0.5 to 5 parts by weight.

The filler which can be added to the solventless epoxy resin composition (I) as required is not particularly limited and may be appropriately selected depending on the required performance, working conditions and the like. Aluminum hydroxide, aluminum silicate, colloidal silica, calcium carbonate, mica,
There are talc, titanium dioxide, quartz powder, zirconium silicate, glass powder, asbestos powder, diatomaceous earth, antimony trioxide and the like.

There are no particular restrictions on the mixing method and the mixing order of the respective components in obtaining the solventless epoxy resin composition (I). On the other hand, typical examples of the fibrous base material (II) used in the present invention include glass fibers, carbon fibers, aromatic polyamide fibers, etc., among which glass fibers are preferable. Among these, glass fibers include E-glass, C-glass, A
-Glass and S-glass exist, but any kind can be applied to the present invention.

These fibrous base materials (II) have rovings, chopped strand mats, continuous mats, cloths, non-woven fabrics, roving cloths, depending on their shapes.
There are surfacing mats and chopped strands, but the types and shapes shown above are appropriately selected depending on the intended use and performance of the molded product, and if necessary, mixing from two or more types or shapes. It may be used. Of these, cloth and non-woven fabric are preferable.

As a method for obtaining a laminated board using the solventless epoxy resin composition (I), for example, a fibrous base material is impregnated with the solventless epoxy resin composition (I) and a predetermined number of layers are laminated. Further, a method in which both upper and lower surfaces thereof are covered with a metal foil and / or a cover film, if necessary, preheated by heating or irradiation with active energy rays, and then heat-cured, solvent-free epoxy resin for fibrous base material Examples include a method of impregnating the composition (I), converting it into a B-stage while removing the polymerizable vinyl monomer in a drying furnace, and then stacking a predetermined number of the B-staged products and heating and curing. When the active energy ray is ultraviolet ray, a known and conventional photopolymerization initiator is usually added.

The above-mentioned heat curing may be carried out without pressure in a continuous heating furnace, or may be continuously heated and pressed by a continuous double belt press. Alternatively, the pre-heated laminate or the B-staged B-staged product may be cut and heat-pressed in a batch size. Pre-heating and B-staging of
Usually, it is carried out in the temperature range of 70 to 150 ° C, and both of the heat curing are carried out at 130 to 190 ° C. The heat and pressure molding is usually performed at a pressure of 5 to 40 kg / cm ² .

The tetraphenylboron compound (E) which is the curing accelerator used in the present invention is not limited to the system of the present invention.
Solventless liquid epoxy resin (A) and polybasic acid anhydride (B)
It can also be used in an epoxy resin composition containing as essential components.

The application to the laminated board has been described in detail above. The use of the epoxy resin composition (I) of the present invention is as follows.
It is not particularly limited, and for example, it can be used for paints, adhesives, sealants, insulating varnishes, castings, fiber reinforced plastics, and the like.

[0033]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. All parts and% in the examples are by weight unless otherwise specified.

Example 1 Epicron 840 (manufactured by Dainippon Ink and Chemicals, Inc.,
Hereafter, abbreviated as DIC. Diglycidyl ether type epoxy resin of bisphenol A, epoxy equivalent 185) 1
7.8 parts, Epicron 152 (diglycidyl ether type epoxy resin of tetrabromobisphenol A manufactured by DIC, epoxy equivalent 370) 22.4 parts, Epicron B-
650 (manufactured by DIC, methylhexahydrophthalic anhydride)
24.7 copies, Dick Light UE-7016 (DIC
(Epoxy vinyl ester resin composed of 73% dimethacrylate of Epiclon 152 and 27% styrene)
28.0 parts, benzoyl peroxide 0.6 part, styrene monomer 4.8 parts and tetraphenylboron-2
-Ethyl-4-methylimidazole (0.5 part) was mixed to obtain a uniform transparent solventless epoxy resin composition (I-1).
Was prepared. The pot life of the obtained composition (I-1) at 25 ° C was measured.

The pot life referred to here is the composition (I-
The number of days until the viscosity of 1) reaches three times the viscosity at the time of preparation (initial viscosity) is shown. The results are shown in Table-1. Comparative Example 1 A solventless epoxy resin composition (I-1 ′) was prepared in the same manner as in Example 1 except that modified imidazole / isocyanate block type microcapsules were used instead of tetraphenylboron-2-ethyl-4-methylimidazole. Was prepared.

The pot life of the resulting composition (I-1 ') at 25 ° C was measured. The results are shown in Table-1. Examples 2 to 3 According to Example 1, the composition (I-2) and the composition (I-3) were prepared in the formulations shown in Table-1, and the pot life of the obtained composition at 25 ° C was measured. did. The results are shown in Table-1.

[0037]

[Table 1]

[0038]

[Table 2]

Example 4 Forty-five parts of the composition (I-1) was used, having a thickness of 0.18 mm and a length of 300 m.
An impregnated base material was obtained by impregnating 55 parts of glass cloth of m and 300 mm in width, and 8 pieces of this were stacked, copper foil of thickness 35 μm was stacked on top and bottom, and then sandwiched between mirror-finished stainless steel plates. It is sandwiched between papers, charged into a heating and pressure molding machine at 110 ° C., heated for 4 minutes under contact pressure, then heated to 110 ° C. to 170 ° C. for 4 to 5 minutes and preheated to form B-stage. 20kg immediately after
The mixture was heated and pressed at a pressure of / cm ² for 60 minutes to obtain a laminated plate (I-1) having a thickness of 1.6 mm. The impregnated state, delamination strength, chemical resistance, water absorption rate and solder heat resistance of the obtained copper clad laminate were measured by the following methods. The results are shown in Table-2.
It was shown to.

Impregnated state: The copper foils on both sides of the obtained laminated plate were removed by etching, and the substrate was observed with a microscope to visually judge the impregnated state. Delamination strength: Peeling off the fibrous base material of the outermost layer with the copper foil attached from the fibrous base material adjacent to the outermost layer, keeping the angle of the peeling direction to the outermost layer base material removal surface at 90 degrees. The peel strength was measured with a Tensilon at a speed of 5 cm / min.

Chemical resistance: The copper foils on both sides of the obtained laminated plate were removed by etching, and the resultant was immersed in methylene chloride at 40 ° C. for 15 minutes.
Minute and 30 minutes, the state of the surface of the laminate was visually judged.

Water absorption (%): 120 after removing the copper foil on one side of the laminated plate cut into 25 mm × 50 mm by etching
Perform a pressure cooker test for 4 hours and 6 hours under the condition of ℃, 2 atm, and calculate the water absorption rate based on the following formula:
The average value is shown.

[0043] (W is the weight of the laminated board before the test, and W'is the weight of the laminated board after the test.) Solder heat resistance: After wiping off the moisture on the surface of the laminated board after the above pressure cooker test well, JIS C-6481 According to the above, each sample was measured 10 times and evaluated according to the following criteria.

◯: No sample having poor solder heat resistance. Δ: There is less than 1/4 of the sample with poor solder heat resistance. X: There are 1/4 or more samples with poor solder heat resistance.

Polylite FG387: Bisphenol type unsaturated polyester resin, styrene content 42
%. Comparative Example 2 A laminated board (I-1 ′) was obtained in exactly the same manner as in Example 4 except that the composition (I-1 ′) was used. Similar characteristics were measured for the obtained copper-clad laminate. The results are shown in Table-2.
It was shown to. Examples 5-6 Laminates (I-2) and (I-) were prepared in the same manner as in Example 4 except that the composition (I-2) or (I-3) was used.
3) were obtained respectively. Similar characteristics were measured for the obtained copper-clad laminate. The results are shown in Table-2.

[0046]

[Table 3]

[0047]

Since the epoxy resin composition of the present invention uses a tetraphenylboron compound as a curing accelerator, the composition is uniformly transparent, sufficiently stable, and excellent in moldability. Has a great effect.

When the epoxy resin composition of the present invention is used, for example, in the production of a laminate, it is possible to impregnate a fibrous base material for a long time, and the impregnated state is good, and finally various kinds of There is an advantage that a laminate having excellent physical properties can be obtained.

Claims (4)

[Claims] 1. A solventless liquid epoxy resin (A), a polybasic acid anhydride (B), an epoxy vinyl ester resin and / or an unsaturated polyester resin (C), a polymerization initiator (D), and a tetraester. An epoxy resin composition (I) containing a phenylboron compound (E) as an essential component. 2. A tetraphenylboron compound (E) is
The composition according to claim 1, which is a tetraphenylboron amine salt. 3. A method for producing a laminate, which comprises impregnating a fibrous base material (II) with the composition (I) according to claim 1 to obtain an impregnated base material (III), and then heat-molding the impregnated base material. 4. The production according to claim 3, wherein after obtaining the impregnated base material (III), the impregnated base material (III) is overlaid, preheated to be B-staged, and then heat-pressed. Method.