JPH0428015B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides an organic polybasic acid anhydride curing agent,
A printed wiring board using a prepreg impregnated with a solvent-free epoxy resin varnish using a liquid curing agent made by eutecticizing a monofunctional polybasic acid anhydride and a polyfunctional polybasic acid anhydride. The present invention relates to a method for manufacturing epoxy laminates for use in industrial applications. [Conventional methods and their problems] Epoxy resin laminates for printed wiring boards are mainly manufactured using prepregs obtained using varnishes containing solvents. However, this method
In the prepreg manufacturing process, it is necessary to remove the solvent contained in the varnish, and the drying process requires a large amount of heat and is difficult to recover, so not only is most of it wasted, but it also degrades the working environment. There was also a risk of fire and explosion. Furthermore, it is impossible to completely remove the solvent in order to maintain the prepreg at the B-stage, and residual solvent may cause defects in soldering heat resistance and other physical properties. As a countermeasure to this problem, there is a method of using a solvent-free varnish. For example, JP-A-57-109829, JP-A-57-
Dicyandiamide-cured epoxy resin system, amine-cured epoxy resin system as disclosed in JP-A No. 44619, JP-A-58-15528, JP-A-57-70127, etc.;
58-107312, JP-A-58-87122, JP-A-58-87123
Novolac-type phenol-cured epoxy resin system as disclosed in JP-A-57-57626, JP-A-57
-9742, JP-A-59-49240, polybasic acid anhydride-cured epoxy resin systems; other examples include dibasic acid hydrazide-cured epoxy resin systems, ring-opening polymerization-cured epoxy resin systems, and the like. The requirements for these solvent-free epoxy resin systems are that the varnish is uniform, that the viscosity is low enough to be impregnated into the base material, that the pot life is long, and that it is easy to B-stage the prepreg itself. It is stable and has a high curing speed of the prepreg during lamination molding, and the physical properties of the obtained laminate are good. By the way, when using liquid acid anhydride as a hardening agent, which is widely used in solvent-free varnish,
Epoxy resin laminates have the advantage of being uniformly compatible with epoxy resins, making it easy to obtain a long pot life and stable B-stage formation, and have physical properties equivalent to or better than those of epoxy resin laminates made using conventional solvent methods. When making boards, it is necessary to further reduce the viscosity of the varnish, and reactive diluents are usually used for this purpose, but it is also important to , methylene chloride resistance), etc., were still insufficient. [Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have developed a method that lowers the viscosity of a solvent-free varnish without using a reactive diluent, and improves solder heat resistance. The present invention was completed as a result of extensive research into a method for producing glass epoxy laminates with improved properties such as hardness, measling properties, and solvent resistance (particularly resistance to methylene chloride). That is, in the present invention, a bisphenol A type epoxy resin a having an epoxy equivalent of 500 or less, a monofunctional organic polybasic acid anhydride b, and a polyfunctional organic polybasic acid anhydride c are eutectic and liquefied. 40% solvent-free varnish containing curing agent and curing accelerator d as essential ingredients.
One or more sheets of B-stage prepreg obtained by impregnating and heating a reinforcing base material at ~100°C are stacked, and if necessary, metal foil is layered on one or both sides of the prepreg for lamination molding. This is a method for producing an epoxy resin laminate for a printed wiring board, which is characterized in that, in a preferred embodiment, as the polyfunctional organic acid anhydride c, general formula (1); 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,
2-dicarboxylic acid is used. The configuration of the present invention will be explained below. The bisphenol A type epoxy resin a having an epoxy equivalent of 500 or less in the present invention includes bisphenol A type epoxy resin, tetrabromo bisphenol A type epoxy resin, etc., and those having various epoxy equivalents are commercially available. , either can be used. Among these, especially those with an epoxy equivalent of 200
The following liquid materials or mixtures of these liquid materials and solid materials that are liquid at room temperature are preferred. The monofunctional acid anhydride b used for preparing the eutectic liquid curing agent of organic polybasic acid anhydride of the present invention may be aromatic, aliphatic, alicyclic, halogenated, or Various products such as fusion and adduct systems are commercially available, and any of them can be used. Among these, those that are liquid at room temperature are particularly preferred, and specific examples include hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, dodecenylsuccinic anhydride, and anhydride. Citraconic acid; Epicure YH-306, YH-, which is commercially available as a liquid alicyclic acid anhydride curing agent.
307 (manufactured by Yuka Ciel Epoxy Co., Ltd.; phthalic anhydride, tetrahydrophthalic anhydride, methylnadic acid, trimellitic anhydride, chlorendic anhydride, maleic anhydride, succinic anhydride, itaconic anhydride, polyazelite polyanhydride, etc.) Solid acid anhydrides and pyromellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bistrimelitate, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2- Examples include liquid eutectic mixtures with polyfunctional acid anhydrides such as dicarboxylic acids. Examples of polyfunctional organic acid anhydrides c include pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and ethylene. Glycol bis trimellitate, acetyl glycerol bis trimellitate, polycaprolactone bis trimellitate, trimellitic acid triglyceride, 5-(2,5-
dioxotetrahydrofuryl)-3-methyl-3
Specific examples include -cyclohexene-1,2-dicarboxylic acid, particularly 5-(2,5-dioxotetrahydrofuryl) represented by the above general formula (1).
-3-Methyl-3-cyclohexene-1,2-dicarboxylic acid is preferred. The blending ratio of polyfunctional acid anhydride c to monofunctional acid anhydride b is an amount corresponding to 5 to 60% of the acid anhydride equivalent of the polybasic acid anhydride used, and this is equivalent to epoxy equivalent of 1. In contrast, as acid anhydride equivalent
It is in the range of 0.035 to 0.72 equivalent, and depending on the type of polyfunctional polybasic acid anhydride, the specific equivalent range to be used is as follows: ●MCTC: 0.035 to 0.7 ●Pyromellitic anhydride ethylene glycol bistrimelitate : 0.035 to 0.4 ●Benzophenone tetracarboxylic trimellitate Triglyceride acetyl glycerol bis trimellitate Polycaprolactone bis trimellitate : 0.035 to 0.3. If the amount used is less than 5%, the improvement in physical properties will be insufficient, and if it is used more than 60%, it will be difficult to achieve eutectic mixing to form a liquid or the stability of the prepreg will be impaired, so it is preferable. do not have. The amount of the curing agent that is a eutectic liquid curing agent of organic polybasic acid anhydride [b+c] is preferably such that the acid anhydride equivalent is in the range of 0.7 to 1.2 per 1 epoxy equivalent of the epoxy resin a. In particular, 0.9 to 1.1 is preferable. As the curing accelerator d of the present invention, commercially available tertiary amines, imidazoles, imidazole-metal salt complexes, Lewis acid-amine complexes (for example, BF ₃ -amine complexes), acetylethylenediamines, amine imide compounds, etc. Both can be used. Specifically, 2-methylimidazole, 2-ethylimidazole, 1,2-dimethylimidazole, 2-isopropylimidazole,
2-Undecylimidazole, 2-phenylimidazole, 4-methylimidazole, N-ethylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-ethyl-4-methylimidazole, imidazole and metal complexes such as Cu, Ni or Co,
Cyanoethyl imidazole obtained by the reaction of 2-methylimidazole with acrylonitrile, etc., and imidazoles obtained by adding trimellitic acid, etc. to these, and reactants of these with dicyandiamide; BF ₃ -monoethanolamine, BF ₃ -Monoethylamine, _BF3 -triethylamine, BF3 _- benzylamine, _BF3 -dimethylaniline, _BF3 -hexylamine, _BF3-
2,6-diethylaniline, _BF3 -aniline,
_BF3 -amine chains such as _BF3 -piperidine; tri-2,4,6-dimethylaminomethylphenol, 2-dimethylaminomethylphenol, piperidine, benzyldimethylamine, triethanolamine, triethylamine, pyridine, (1 ，
8-Diaza-bicyclo(5,4,0)undecene-7, and tertiary amines such as salts of these amines with phenol, 2-ethylhexanoic acid, oleic acid, diphenylphosphorous acid, and organic phosphoric acid compounds. Type; Epicure YHP (= trade name, Yuka Ciel Epoxy Co., Ltd.) made from 1,1-dimethylhydrazine
Examples include amine imide compounds such as (manufactured by Nippon Steel & Co., Ltd.); trivalent phosphorus compounds such as triphenylphosphine; and organic acid metal salts such as tin octylate. The amount of the curing accelerator or catalyst used is preferably 0.1 to 10 parts by weight per 100 parts by weight of the epoxy resin, and the gelation time of the varnish measured at 160°C is 1.
~10 minutes is suitable for producing a stable prepreg. The components explained above are mixed to form the solvent-free varnish of the present invention. The mixing order of each component is not particularly limited, but usually, the epoxy resin component a is mixed with a eutectic liquid curing agent of polybasic acid anhydride [b+
c] is heated to a temperature of 100° C. or less and stirred and mixed uniformly to make it into a liquid state, and then the curing accelerator d is added and stirred and mixed. At this time, the viscosity of the varnish is usually at a temperature of 40°C.
~100℃, preferably 200cps or less at 40-80℃,
In particular, it should be 150cps or less. When preparing a solvent-free varnish, internal mold release agents,
Well-known and commonly used additives such as pigments may be added, and reactive diluents such as monoglycidyl ether type epoxy resins and compounds with unsaturated double bonds may be added to the epoxy. It can be added in an amount of 10% by weight or less of the resins [a, b]. The prepreg of the present invention is prepared by impregnating and heating a reinforcing base material with the varnish prepared by the above method. The reinforcing base materials include fibrous reinforcing materials of various shapes such as roving, chopped strand mat, continuous mat, cloth, roving cloth, surfing mat and chopped strand, as well as glass fiber and carbon fiber. , fully aromatic polyamide fibers, and blends thereof,
In particular, alkali-free, silane coupling agent-treated glass cloth, which is used in laminates for electrical applications, is preferably used. 30 to 70% by weight of the prepreg obtained by heating the solvent-free varnish of the present invention to 40 to 100 °C, preferably 40 to 80 °C, and impregnating and applying it to a base material,
In particular, impregnated in a range of 40 to 55% by weight,
Usually, this is done at a temperature of 80~180℃, preferably 100~
Heat it at 160℃ to make B-stage prepreg.
In addition, B-
It can also be used as stage prepreg. Using one or more sheets of prepreg obtained by the above manufacturing method, if desired, metal foil (for example, electrolytic copper foil, etc.) is layered and sandwiched between mirror plates under normal lamination molding conditions, temperature 100-200℃, pressure. 5～
The laminate of the present invention is manufactured by lamination molding at 100 kg/cm ² for 0.5 to 5 hours. [Example] Examples and comparative examples will be shown and explained below. Note that "parts" and "%" in Examples, Comparative Examples, and Table 1 are based on weight unless otherwise specified. Example 1 Mix the following ingredients at 60℃ to obtain a uniform viscosity of 150cps.
(at.60℃) varnish was obtained. ●Bisphenol A diglycidyl ether (product name: Epicote 828, epoxy equivalent 190)
100 parts Hexahydrophthalic anhydride (acid anhydride equivalent 154)
48 parts ● Epiclon B-4400 (trade name; manufactured by Dainippon Ink and Chemicals Co., Ltd., acid anhydride equivalent: 132) 25 parts ● 2-ethyl-4-methylimidazole (=
2E4MZ) 0.5 parts of this solvent-free varnish on glass woven fabric (product name;
EPC188 (manufactured by Arisawa Seisakusho Co., Ltd.) with an impregnation rate of 40% at 60℃
B-
Stage prepreg was prepared. 8 sheets of this prepreg with a thickness of 35 μm on both sides
The copper foils were layered and laminated for 2 hours at a temperature of 175°C and a pressure of 40 kg/cm ² to obtain a double-sided copper-clad laminate with a thickness of 1.65 mm. The properties of this laminate are shown in Table 1. Examples 2 to 12 Varnishes were prepared using the ingredients shown in Table 1 in the same manner as in Example 1, and double-sided copper-clad laminates were created using the varnishes. The properties of this laminate are shown in Table 1. Comparative Example 1 A copper-clad laminate was obtained using the manufacturing method of Example without using a polyfunctional polybasic acid anhydride (Epicron B-4400). The properties of this laminate are shown in Table 1. In Table 1, the measurement methods and abbreviations are as follows. ●Solder resistance: A 50m/m x 50m/m test piece with 1/2 of the copper foil of a copper-clad laminate removed by etching was boiled for 8 hours, washed with water, and immediately wiped with gauze.
Immerse in a 300°C solder bath, observe whether the copper foil, glass cloth, and resin on the test piece peel off, and measure the time until peeling, blistering, etc. occur. ● Measling resistance; 50m/m x 50m/ with copper foil etched away
A large number of drill holes of 1.0 mmφ were drilled in a test piece of m.
After boiling for 8 hours, wash with water, wipe off moisture with gauze, and immediately immerse in soybean oil at 260°C for 30 seconds to observe the state of adhesion between the glass cloth and the resin. No abnormality: ○, peeling, blistering, etc.: × ● Methylene chloride resistance; 50m/m x 50m/ with copper foil etched away
After immersing the test piece in methylene chloride at 25°C for 30 minutes, it was stored in a hot air circulation dryer at 50°C for 1 hour 10 times, and the state of adhesion between the glass cloth and the resin on the test piece was observed. do. No abnormalities: ○, Whitening, blistering, etc.: × ●Epoxy resin; Epicoat 828: (manufactured by Yuka Ciel Epoxy Co., Ltd.)
Bisphenol A diglycidyl ether, epoxy equivalent: 190 YED-111: Alkyl monoglycidyl ether, epoxy equivalent: 330 ESB-400: (manufactured by Sumitomo Chemical Co., Ltd.) Bromine content
48% tetrabromo bisphenol A type epoxy resin, epoxy equivalent: 400 ELB-250L: Tetrabromo bisphenol A type epoxy resin with 25% bromine content, epoxy equivalent: 250 ● Monofunctional polybasic acid anhydride; HHAP: Hexahydrophthalic anhydride MMAN: Methyl nadzic anhydride THAP: Tetrahydrophthalic anhydride MTAP: Methyltetrahydrophthalic anhydride Polyfunctional polybasic acid anhydride; B4400: 5-(2,5-dioxotetrahydrofuryl)-3 -methyl-3-cyclohexene-1,
2-Dicarboxylic acid PHAC: Pyromellitic anhydride BPAC: Benzophenone tetracarboxylic anhydride EGBC: Ethylene glycol bistrimelitate TMGC: Trimellitic acid triglyceride AGTC: Acetylglycerol bistrimelitate ●Curing accelerator; 2E4MZ: 2-ethyl -4-Methylimidazole DBU: (1,8-diaza-bicyclo(5.4.0) undecene-7 BDMA: Benzyldimethylamine YPH-201: Hardening accelerator made from 1,1-dimethylhydrazine (trade name, oil (Manufactured by Kasiel Epoxy Co., Ltd.) [Operations and Effects of the Invention] As is clear from the detailed description of the invention, Examples, and Comparative Examples above, the solvent-free varnish of the present invention and a laminate made from a prepreg using the same. With this manufacturing method, the varnish has excellent storage stability and low viscosity, making it easy to manufacture prepregs, and the physical properties of the manufactured laminates are also better than those that do not use polyfunctional polybasic acid anhydrides. It is possible to provide highly practical laminates that are significantly superior to laminates made using conventional solvent-containing varnishes and can be used extremely favorably as printed wiring boards. Recognize.

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Claims (1)

[Claims] 1. Bisphenol A having an epoxy equivalent of 500 or less
A solvent-free varnish containing as essential components a curing agent and a curing accelerator d made into a liquid by eutectic melting of a type epoxy resin a, a monofunctional organic polybasic acid anhydride b, and a polyfunctional organic polybasic acid anhydride c. One or more sheets of B-stage prepreg obtained by impregnating and heating a reinforcing base material at 40 to 100℃ are layered, and if necessary, metal foil is layered on one or both sides and laminated. A method for producing an epoxy resin laminate for printed wiring boards, characterized by: 2 The polyfunctional organic acid anhydride c has the general formula (1); 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,
A method for producing an epoxy resin laminate according to claim 1, wherein the epoxy resin laminate is a 2-dicarboxylic acid.