JPH047376B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a thermosetting resin laminate having excellent flame retardancy and good punching workability. With the recent remarkable development of the electronic equipment industry, the development and density of electronic equipment has progressed, and from the standpoint of safety, the flame retardant requirements for printed wiring board laminates have become even stricter. Legislation and standards have been developed and regulations are being strengthened. Also,
Recently, as the density of printed wiring boards used in electronic devices has increased, automatic mounting technology has also advanced, and stricter dimensional accuracy is required, and low-temperature punching is now being performed to meet this requirement. . Conventionally, in order to improve punching workability, external plasticizers have been added to thermosetting resins, or resins have been modified with internal plasticizers. On the other hand, a method for making thermosetting resin flame retardant is to add inorganic compounds such as phosphorus compounds, bromine compounds, nitrogen compounds, and antimony to the thermosetting resin, either alone or in combination. It is done by. However, when a large amount of plasticizer is used to improve punching workability, solvent resistance, water resistance, heat resistance, and electrical properties deteriorate. In addition, since a flame retardant is further added to impart flame retardancy, solvent resistance, water resistance, heat resistance, and electrical properties are significantly deteriorated. In addition, there is a problem of compatibility between the plasticizer-added resin and the flame retardant used, and it is difficult to maintain this balance.As a countermeasure, dimer acid-modified halogenated bisphenol A diglycidyl ether reaction products, etc. There is an example of using epoxy (Japanese Patent Application Laid-Open No. 74876/1986), but since the halogenation content is low, it is necessary to use multiple epoxy groups, and the reaction product is The storage stability of the blended thermosetting resin varnish and the prepreg obtained by impregnating this varnish is significantly reduced, and workability is poor. The present invention was made in view of these points, and includes 2 to 7 moles of halogenated bisphenol A diglycidyl ether type epoxy resin, dimer acid (acid value 170 to 210, dimer acid content 20 to 98% by weight).
Molding a base material impregnated with a predetermined amount of a thermosetting resin varnish containing a reaction product obtained by heating and reacting 1 to 3 moles of halogenated phenol to an oxidation level of 1 or less as a flame retardant. This is a method for producing a flame-retardant laminate, which is characterized by: Halogenated bisphenol A diglycidyl ether type epoxy resin is a bisphenol A diglycidyl ether type epoxy resin in which 1 to 4 hydrogen atoms in the phenyl group are replaced with halogens, such as bromine or chlorine, and the epoxy equivalent and molecular weight are There are no particular restrictions. Preferred commercial products of the halogenated bisphenol A diglycidether type epoxy resin used in the present invention include YDB-340 (trade name manufactured by Toto Kasei Co., Ltd.), YDB-400 (trade name), and ESB-340 (trade name manufactured by Sumitomo Chemical Co., Ltd.). ), ESB-400 (same name), Epicote 1050 (trade name, manufactured by Yuka Ciel Epoxy Co., Ltd.), DER-542 (trade name, manufactured by Dow Chemical Company), etc. As the dimer acid, one having an acid value of 170 to 210 and a dimer acid content of 20 to 98% (weight %, the same hereinafter) is used. Preferred commercially available products include Enpol 1022 (trade name manufactured by Emery), Empol 1024 (same), VersaDime 216 (trade name manufactured by Henkel Japan), VersaDime 288 (same), and Lastaydime DA-200 (trade name manufactured by NICCA Kasei). name) Rusty Dime DA-500 (same)
etc. Halogenated phenols include monovalent phenols such as monobromophenol, dibromophenol, and tribromophenol, and divalent phenols such as tetrabromobisphenol A. There are no particular limitations on the halogen species and phenol species, and they may be used alone or in combination. However, it is preferable not to leave unreacted hydroxyl groups after the reaction. Since unreacted hydroxyl groups in halogenated phenols tend to cause deterioration in electrical properties, it is preferable to use monovalent halogenated phenols. In addition, divalent halogenated phenols tend to polymerize, tend to deteriorate the compatibility of the reaction product which is a new flame retardant, and tend to reduce the storage stability of the varnish for impregnation with a thermosetting resin. The halogenated bisphenol A diglycidyl ether type epoxy resin, dimer acid, and halogenated phenol are 2 to 7 mol, 1 to 3 mol, respectively.
1 to 3 mol, preferably 3 to 5 mol each, 1
~2 mol, 2 to 3 mol are blended, and the mixture is reacted at 80 to 150°C until the acid value becomes 1 or less, preferably 0.6 or less. The reactions may be carried out simultaneously or may be carried out separately. Organic amines used as catalysts include N,N-dimethylcyclohexylamine, benzyldimethylamine, triethylamine, diethylamine, dimethylamine, N,N-dimethylaniline, N-(B
-hydroxyethyl)amine, and alkali metal hydroxides. The obtained reactant has a moderate amount of epoxy group left as a reactive group, and has an epoxy equivalent of 900 to 900.
2600 and is used as a reactive flame retardant. The thermosetting resins used in the present invention include phenolic resins, preferably drying oils such as tung oil, dehydrated castor oil, and euticica oil, and polybutadiene-modified resol phenolic resins, and epoxy resins (epoxy equivalent, molecular weight, etc.) ), other polyester resins, melamine resins,
There are benzoguanamine resins, etc., and general commercial products are sufficient. As the solvent for thermosetting resin varnish, common solvents such as toluene methyl, ethyl ketone, acetone, and alcohol are used. The thermosetting resin varnish containing the flame retardant of the present invention is impregnated in a predetermined amount onto a common base material for thermosetting resin laminates such as paper, glass cloth, glass nonwoven fabric, synthetic fiber cloth, etc., and then molded into a laminate. shall be. Molding is carried out using one sheet or a required number of base materials impregnated with a flame retardant-containing thermosetting resin varnish at the required temperature (including room temperature) and the required pressure (including no pressure). As flame retardants used auxiliary to the phenol resin, tricresyl phosphate, triphenyl phosphate, tetrabromobisphenol A, etc. are used. Similarly, for epoxy resins, tetrabromobisphenol A, brominated epoxy novolac, etc. are used. Similarly, for polyester resins, tetrabromo phthalic anhydride, tetrachlorophthalic anhydride, etc. are used. As explained above, the present invention involves reacting dimer acid, which is effective as a plasticizer, with a halogenated bisphenol A diglycidyl ether type epoxy resin, which is effective as a flame retardant, and a halogenated phenol. By adding a reactive flame retardant/plasticizer with a moderate amount of residual flame retardant to a thermosetting resin varnish, impregnating varnish and prepreg with excellent storage stability can be obtained. It has flammability, improves punching workability, and is reactive.
Built into a thermoset resin structure, solvent resistant,
A laminate with good water resistance, heat resistance, and electrical properties is produced. That is, the present invention provides halogenated bisphenol A
A reaction product obtained by reacting diglycidyl ether type epoxy resin, dimer acid, and halogenated phenol is added to a thermosetting resin as the main flame retardant, along with other flame retardants as necessary, and this resin is By applying a predetermined amount of varnish to a base material such as paper, drying it, and then molding the required number of base materials under heat and pressure, a laminate that is flame retardant and has good punching workability can be produced. can be manufactured. The storage stability of thermosetting impregnating varnishes and prepregs using the flame retardant of the present invention is good, but since halogenated phenols are used, the epoxy groups in the halogenated bisphenol A diglycidyl ether type epoxy resin are By reacting with the hydroxyl group in the partially halogenated phenol,
This is thought to be due to a decrease in epoxy groups. Example 1 240 g of tetrabromobisphenol A diglycidyl ether type epoxy resin (Epicote 1050 epoxy equivalent weight 395-410) and 30 g of dibromophenol
60 g of dimer acid (Empol 1022 acid value 195-197 dimer content 75%) and 6 g of benzyldimethylamine as a catalyst were mixed and reacted at 100° C. for 4 hours to obtain a product. The acid value was 0.45, the bromine content was 41%, and the epoxy equivalent was 1000-1200. Tung oil and meta-cresol are reacted under an acidic catalyst, and then resolized with paraformaldehyde and an alkali catalyst to form a resolized resin (solid content) with a tung oil modification amount of 25% (parts by weight, same below) as above. The above impregnating varnish was mixed with 25 parts of the shown synthetic flame retardant and 25 parts of cresyl phenyl phosphate, and was applied to a craft substrate that had been previously treated with a water-soluble melamine-modified phenolic resin (resin coverage: 12%). It was impregnated and dried to a resin adhesion of 50%, and five sheets of this prepreg were combined with adhesive-coated copper foil and laminated under heat and pressure to obtain a 1.6 mm single-sided copper-clad laminate. The storage stability results of the impregnating varnish and prepreg and the properties of the copper-clad laminate are shown in the attached table. Comparative Example 1 Same tetrabromobisphenol A as in Example 1
160 g of diglycidether type epoxy resin, 60 g of the same dimer acid as in Example 1, and 4.4 g of benzyldimethylamine as a catalyst were blended and reacted at 100° C. for 4 hours to obtain a product. Acid value 0.4, bromine content 36%
It was hot. 30 parts of this flame retardant and 100 parts of resol resin with 25% tung oil modification obtained by the same manufacturing method as in Example 1.
(solid content) was blended with 25 parts of cresyl phosphate to make an impregnating varnish. Thereafter, a copper-clad laminate was obtained in the same manner as in Example 1. The storage stability results of the impregnating varnish and prepreg and the properties of the copper-clad laminate are shown in the attached table. Comparative Example 2 Tung oil modified amount 25% obtained by the same manufacturing method as Example 1
16 parts of the same tetrabromobisphenol A diglycidyl ether type epoxy resin as in Example 1, 2 parts of dibromophenol, and 25 parts of cresyl diphenyl phosphate were added to 100 parts of the resolized resin (solid content), and an impregnating varnish was prepared. I got it. Thereafter, a copper-clad laminate was obtained in the same manner as in Example 1. The storage stability results of the impregnating varnish and prepreg and the properties of the copper-clad laminate are shown in the attached table.

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Claims (1)

[Claims] 1. 2 to 7 moles of halogenated bisphenol A diglycidyl ether type epoxy resin, dimer acid (acid value 170 to 210, dimer acid content 20 to 98% by weight)
A base material is impregnated with a predetermined amount of a thermosetting resin varnish containing a reaction product obtained by heating and reacting 1 to 3 moles of halogenated phenol to an acid value of 1 or less as a flame retardant, and then molded. A method for producing a flame-retardant laminate, characterized by: 2 Claim 1 characterized in that the halogenated phenol is a monovalent halogenated phenol
A method for producing a flame-retardant laminate as described in Section 1.