JPS6063251A - Flame-retardant phenolic resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition afforded with adequate flame-retardancy without impairing mechanical strength, electrical properties, and heat and solvent resistance, by incorporating specific resorcin-polyphosphate compound in (modified) resol-type phenolic resin. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100pts.wt. of a (modified) resol-type phenolic resin with (B) 10-70pts.wt. of a resorcin-polyphosphate compound of formula (R is H or methyl; n is 1-5) (pref. n=1-3) and, if required, (C) organic halogen compound, antimony trioxide, etc. The component (B) can be prepared by the reaction between resorcin and phosphorus oxychloride followed by reaction with phenol and/or cresol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flame-retardant phenolic resin composition, and more particularly to an a-smoking composition in which a phenolic resin is blended with a specific resorcinol polyphosphate compound.

Conventionally, flame retardant methods for phenolic resins include organic phosphate esters such as triphenyl phosphate and tricresyl phosphate, organic halogen compounds such as tetrachlorobisphenol A1, tetrabromobisphenol A1, chlorinated paraffin, and additives such as antimony trioxide. It is known to include flame retardants.

However, there is a limit to the amount of these flame retardants that can be added to phenolic resins, and when trying to impart sufficient flame retardance, mechanical strength, electrical properties, heat resistance, and solvent resistance may be significantly impaired. Or, it often corrodes equipment and equipment during processing and molding.

Among these flame retardants, organic phosphate esters are less corrosive, but have poorer electrical properties and heat resistance, and are not practically satisfactory. In order to eliminate these drawbacks, phenyl
It has also been proposed to use hydroquinone polyphosphate, but this compound is solid at room temperature and is not only inconvenient to add to phenolic resins, but also has poor solvent resistance and mechanical strength, and is also poor in heat resistance and electrical resistance. The effect of improving properties was still insufficient.

In view of these points, the present inventors have made extensive studies and found that the resorcinol polyphosphate compound represented by the following general formula (1) is liquid at room temperature and can be easily blended into phenolic resin. It has been found that not only the solvent resistance and mechanical strength are excellent, but also the heat resistance and electrical properties are significantly improved. That is, the present invention provides a flame-retardant phenol resin composition, which is obtained by adding a polyphosphate compound represented by the following general formula (1) to a phenol resin.

(In the formula, R represents a hydrogen atom or a methyl group, and n is 1 to 5
shows. ) The resorcin polyphosphate compound represented by the general formula (1) used in the present invention can be prepared by a known method for producing polyphosphate compounds, for example, by reacting resorcin with phosphorus oxychloride and then adding phenol and/or cresol. A compound having a desired degree of polymerization can be produced by appropriately adjusting the molar ratio of these compounds.

A compound with a large average degree of polymerization n has a high viscosity, which is not only inconvenient to use but also tends to deteriorate the physical properties of the resulting phenol resin composition. Therefore, n should be in the range of 1 to 5, preferably 1 to 3. It is adjusted so that

The flame-retardant phenolic resin composition of the present invention can be obtained by mixing a normal resol type phenol resin or a resol type phenol resin modified with various modifiers and a resorcinol polyphosphate compound.

The amount of the resorcinol polybosphate compound used in the present invention is generally 10 to 70 parts by weight per 100 parts by weight of the phenol resin, but is not necessarily limited to this ratio depending on the purpose of use.

The resorcinol polyphosphate compound used in the present invention imparts good flame retardancy to phenol resin even when used alone, but if necessary, it may be combined with other organic phosphate esters, tetrachlorohisphenol A1, etc. Tetrabromobisphenol A1. Organic halogen compounds such as chlorinated paraffin, antimony dioxide, etc. can be used in combination.

The flame-retardant phenolic resin composition obtained by the present invention is particularly suitable for electrical materials such as laminates, molding materials, and insulating panels, and can also be applied to various laminate materials, adhesives, and the like.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Resol type phenol tree B obtained under normal reaction conditions
50 parts of the organic phosphate listed in Table 1 were mixed and dissolved in 100 parts, and the mixture was diluted with acetone to obtain a phenol resin liquid.

Apply this resin liquid to 10 mils thick linter paper with a resin amount of 5
After impregnating the paper to about 0 to 53% to form a B stage, nine sheets of this impregnated paper were stacked, silver foil was further stacked on one side of the paper, heated and compressed for 60 minutes under normal conditions, and then cooled.

The results of measuring the mechanical properties of the obtained laminate are shown in Table 1 below.

Example 2 50 parts of the organic phosphate listed in Table 2 (based on 100 parts of resin) was added to a cresol/formalin resin face, impregnated with linter paper, and a laminate was prepared in the same manner as in Example 1. Obtained.

The results of measuring the mechanical properties of the obtained laminate are shown in Table 1 below.

Claims (1)

[Claims] A flame-retardant phenol resin composition comprising a phenol resin and a polyphosphate compound represented by the following general formula (1). (In the formula, R represents a hydrogen atom or a medyl group, and n is 1 to 5
shows. )