JPH01287121A - Resin composition for electrical laminate - Google Patents

Abstract

PURPOSE:To obtain the subject easily processable composition having excellent flame-retardance, at a low cost, by adding an epoxy resin, a bromine-containing alkyd resin and a radical curing catalyst to a specific styrene monomer solution at specific ratios. CONSTITUTION:The objective composition can be produced by compounding (A) 100pts.wt. of a styrene monomer solution of a resin having double bond on side chain and consisting of a main chain composed of a copolymer containing styrene monomer unit and maleic anhydride residue and a side chain containing (meth)acrylic acid ester having primary hydroxyl group and bonded to said maleic anhydride residue through an ester bond, wherein said styrene monomer solution contains 20-60wt.% of the main chain, >=10wt.% of the side chain and >=20wt.% of styrene monomer, (B) 5-50pts.wt. of an epoxy resin, (C) 20-100pts.wt. of a bromine-containing alkyd resin and (D) a radical curing catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin composition for electrical laminates used in electrical equipment, electronic equipment, communication devices, and the like.

[Prior art and its problems] Typical resin compositions used in electrical laminates, such as metal foil-clad electrical laminates, are conventionally phenol resin-based, epoxy resin-based, and unsaturated polyester resin-based. It is used in combination with various base materials.

Regarding the above-mentioned resin systems, for example, phenol resin systems have problems in that molding takes a long time and molding pressure is high. In addition, epoxy resin systems have problems in that they require removal of solvent during molding and are relatively expensive.

Unsaturated polyester resin systems generate heat quickly during curing, so
There are problems such as warping of the laminate due to curing shrinkage and unevenness on the surface of the laminate.

In addition, flame retardancy is insufficient, and the methods for providing it have common technical unresolved points and cost problems.

[Problems to be Solved by the Invention] The present invention provides a novel flame-retardant resin composition that can be easily molded and is inexpensive and can be used to manufacture electrical laminates with balanced electrical properties and mechanical properties. With the goal.

[Means for solving the problem] As a result of intensive research to achieve this objective, the present inventors have found that
Radicals are added to side chain double bond type resins, epoxy resins, and bromine-containing alkyd resins that have an unsaturated group of (meth)acrylic acid ester at the end of the side chain and an ester bond to the maleic anhydride residue in the main chain. It was found that a resin composition consisting of a styrene solution to which a curing catalyst was added could be used for electrical laminates, and the present invention was completed. That is, the gist of the present invention is that the main chain is a copolymer containing a styrene monomer unit and a maleic anhydride residue, and the side chain is a copolymer containing the maleic anhydride residue and a (meth)acrylic ester having a primary hydroxyl group. A styrene monomer solution of a side chain double bond type resin in which hydroxyl groups are ester bonded has a main chain of 20 to 60% by weight, a side chain of 10% by weight or more, and a styrene monomer of 2
A resin for electrical laminates, which is composed of 0 wt. In the composition.

The present invention will be explained in detail below.

The side chain double bond type resin according to the present invention is composed of a main chain polymer and a side chain having a carbon-carbon double bond at the end, and the main chain is composed of a styrene monomer unit and a maleic anhydride residue. The maleic anhydride residue provides a functional group for forming a side chain in the copolymer, and the side chain is formed by an ester bond.

Next, an example of a method for producing the side chain double bond type resin according to the present invention will be explained.

The copolymer of styrene and maleic anhydride preferably has a copolymer composition and molecular size shown in formula CI).

(Left below) A copolymer of maleic anhydride and styrene is easiest to make by adding maleic anhydride to styrene under polymerization conditions while proceeding with the copolymerization. When the polymerization is stopped when almost no maleic anhydride is detected in the copolymerization solution, a styrene monomer solution can be easily obtained. The molecular weight can be controlled by copolymerizing in the presence of mercaptans or other chain transfer agents.

As an example of a substance forming a side chain, there may be mentioned an esterified product of (meth)acrylic acid having a primary hydroxyl group represented by the general formula [11)%Formula%). It is preferable that this molecular weight does not exceed 1000 at most.

- There should be one hydroxyl group in the (meth)acrylic acid ester represented by the formula [n) in the molecule, and - when carrying out an esterification reaction with the maleic anhydride residue in the copolymer represented by the formula CI), This is a condition to prevent gelation. In addition, it is necessary that it be a primary hydroxyl group in order to facilitate the esterification reaction.

The (meth)acrylic esters applicable to the above are:
Polyethylene glycol mono(meth)acrylates, such as ethylene glycol mono(meth)acrylate, diethylene glycol mono(meth)acrylate, 1,4
polyhydric almonohydroxy(meth)acrylic acid esters such as butanediol mono(meth)acrylate, 1,6 hexanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate; Examples include addition products of ε-caprolactone.

- When a (meth)acrylic acid ester having a primary hydroxyl group represented by formula [11] is added to a styrene solution of a styrene and maleic anhydride copolymer represented by formula [I], - formula Cm) It is possible to generate a Nisthyl bond as shown in .

To a styrene solution of a copolymer of styrene and maleic anhydride shown in [CI], a (meth)acrylic acid ester having a primary hydroxyl group shown in [II] is added, and the esterification reaction is further promoted. As a catalyst for this, tertiary amine, pyridine, organic tin compound (e.g. dibutyltin oxide), organic titanium compound (e.g. titanate ester), triphenylphosphine, quaternary ammonium salt, etc. are added in an amount of 1/1000 to 1/1000 of the above mixture. It is preferable to add in an amount of 1/100 liters by weight, and the temperature is usually between room temperature and 100 liters by weight.
It is in the range of 0°C.

The (meth)acrylic acid ester having a primary hydroxyl group is preferably used in an amount of 1 to 3 equivalents per equivalent of maleic anhydride residue contained in the copolymer of styrene and maleic anhydride.

In the styrene monomer solution of the side chain double bond type resin in the present invention, the main chain must be 20 to 60% by weight, the side chain must be 10% or more, and the styrene monomer must be 20% or more by weight.

If the main chain content is less than 20% by weight, the viscosity of the resin composition will be low and a good molded product will not be obtained. Moreover, if it exceeds 60% by weight, the viscosity of the resin composition becomes high and the impregnating property for profiteers becomes poor. If the side chain content is less than 10% by weight, the mechanical strength of the molded article will be low and the solvent resistance will be poor. Styrene monomer is 20
When the amount is less than % by weight, the viscosity of the resin composition becomes high, which not only impairs impregnation into the base material but also increases costs.

As the epoxy resin used in the present invention, bisphenol A type epoxy resin is typically used in terms of performance, but other types include resorcin type, bisphenol F type, tetrahydroxyphenylethane type, novolac type, glycerin triether type, and alicyclic type. Examples include epoxy resins such as molds and epoxidized soybean oil.

The epoxy resin may have an equivalent weight to the carboxyl group present in the side chain double bond type resin.

The bromine-containing alkyd resin used in the present invention preferably has a hydroxyl value of 10 to 60 degrees and an acid value of 30 to 200 degrees, and preferably has a bromine content of 20 to 90%, which contributes to flame retardancy.

q- As the radical curing catalyst, an organic peroxide catalyst effective for use with polyester resins and vinyl ester resins may be used in combination with a curing accelerator, if necessary.

The temperature during curing may be at least room temperature and below 200°C. When these components are impregnated into a laminate, they are cured as follows.

Radical curing occurs when an epoxy resin and a bromine-containing alkyd resin are added to a styrene monomer solution of such a side chain double bond type resin, and then a radical polymerization catalyst is added to start curing, especially in heat curing. In epoxy resins, a crosslinking reaction occurs simultaneously with radical polymerization due to an addition reaction between styrene and the carboxyl groups generated in the maleic anhydride copolymer and the carboxyl groups of the bromine-containing alkyd.

It has been found that when this composition is used for a laminate, it is possible to produce a laminate that is flame retardant and exhibits little mold-hardening strain.

The present invention will be explained below with reference to Examples.

Example Kraft paper (25cm x 25c) with a basis weight of 135g/g
m) was soaked in an aqueous solution of Nikaledin S-305J (trade name 1 manufactured by Nippon Carbide Co., Ltd., methylolmelamine), squeezed with a roller, and dried at 120°C for 30 minutes.

11.7% by weight was spread on the obtained paper base material. This paper was placed in a flat plate and floated on an impregnating resin solution having the composition shown in Table 1 to allow the resin solution to seep into it.

Commercially available adhesive-attached copper foil rMK-56J (product name) using 6 sheets of paper impregnated with resin liquid and phenolic adhesive.

(manufactured by Mitsui Kinzoku Mining Co., Ltd.) was stacked one on top of the other, sandwiched between two mirror plates, placed in a press preheated to 120°C, and held at a pressure of 0.5 kg/cJ for 10 minutes.

Take out the laminate together with the mirror plate from the press and press 12.
The mixture was placed in an air oven at 0°C and heating continued for 5 hours.

The laminate was taken out of the oven together with the mirrored plate, and after being left to cool, the laminate was removed.

The resulting laminate had a thickness of 1.57 to 1.83 mm.

Table 2 shows the characteristic values of the laminate.

Comparative Example A laminate was produced using the impregnating resin mixture shown in Table 1 in the same manner as in the Example. Table 2 shows the performance of the obtained laminate.

(The following is a blank space) [Effects] As can be seen from the above explanation, by adopting the structure of the present invention, it is possible to create electrical laminations that not only do not have the disadvantages of phenolic resins, but also are superior to radical-curable flame-retardant unsaturated polyester resins. They succeeded in providing a resin composition for plates.

Patent applicant: Showa Kobunshi Co., Ltd. Showa Denko Co., Ltd.

Claims (1)

[Claims] The main chain is a copolymer containing styrene monomer units and maleic anhydride residues, and the side chains are the maleic anhydride residues and 1
A styrene monomer solution of a side chain double bond type resin formed by ester bonding of the hydroxyl group of a (meth)acrylic ester having a class hydroxyl group has a main chain of 20 to 60% by weight, a side chain of 10% by weight or more, and a styrene monomer of 20% by weight. % or more, and 5 to 50 parts by weight of epoxy resin and 20 parts by weight of bromine-containing alkyd resin to 100 parts by weight of the styrene monomer solution.
A resin composition for electrical laminates, comprising ~100 parts by weight and a radical curing catalyst.