JPS6320351A - Phenolic resin composition - Google Patents

Abstract

PURPOSE:To improve the flexibility of cured products and to improve the low- temperature punchability of laminated sheets obtd. by impregnating a substrate with the title resin, by blending a phenolic resin with a polyester obtd. by using an alkylene oxide adduct of bisphenol A. CONSTITUTION:A resin compsn. is obtd. by blending 100pts.wt. phenolic resin with 1-40pts.wt. polyester obtd. by reactive a polybasic acid with an alkylene oxide adduct of bisphenol A as part or the whole of a glycol component. As the polybasic acid component, unsaturated polybasic acids are particularly preferred, because they have an unsaturated bond which serves as a crosslinking point with the phenolic resin in the resulting polyester molecule. As the phenolic resin, alkylphenolic resins and drying oil-modified resins are preferred.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a phenol resin composition, and more specifically to a phenol resin composition containing a specific polyester resin to improve the flexibility of the cured product. The present invention relates to a resin composition.

Furthermore, the present invention relates to a phenolic resin composition that has improved low-temperature punchability of a laminate obtained by impregnating and curing a base material such as paper.

[Conventional technology and its problems]

Conventionally, phenolic resin has been used as a thermosetting resin with excellent electrical properties, heat resistance, and solvent resistance in various molding materials, and in particular, laminates made by impregnating a base material such as paper with it and curing it have been used. Widely used as printed circuit boards and insulating substrates.

The above-mentioned laminate is punched during the processing process, and various methods are used to impart flexibility to the resin in order to obtain desirable punching workability without cracking or peeling. It has been proposed and put into practical use. The methods can be roughly divided into two types: a method using an additive type plasticizer and a method using a reactive plasticizer.

The former involves adding plasticizers such as phthalate ester, rosin, and polyvinyl acetal to phenolic resin, and -a
Although the plasticizer has a large plasticizing effect, since the plasticizer simply exists in a dispersed state in the resin, heat resistance, solvent resistance, electrical properties, etc. may deteriorate, and it may bleed out from the resin after a long period of time. may occur.

On the other hand, examples of the latter include addition reaction products of drying vegetable oils such as tung oil, linseed oil, and castor oil with phenols, and addition reaction products of epoxidized modified products of the above drying vegetable oils and phenols. Since it is partially crosslinked with the phenol resin, it has excellent heat resistance, solvent resistance, electrical properties, etc., but on the other hand, the plasticizing effect is somewhat reduced.

Generally, laminates made using plasticized phenolic resin compositions are punched by heating to about 60 to 80 degrees Celsius, above room temperature. From the viewpoint of improving the performance, it is desired to develop materials that can be punched at lower temperatures, preferably at room temperature.

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art, and have found that a phenolic resin composition containing a specific polyester resin has remarkable flexibility. It was discovered that an excellent laminate can be obtained, leading to the present invention.

That is, the present invention uses an alkylene oxide adduct of bisphenol A as part or all of the glycol component, and reacts this with a polybasic acid to produce a polyester resin in an amount of 1 to 40 parts by weight per 100 parts by weight of the phenol resin. Parts by weight of phenolic resin compositions.

Polyester resins are generally obtained by polycondensing a glycol component and a polybasic acid component consisting of a saturated polybasic acid and/or an unsaturated polybasic acid, but the polyester resin used in the present invention contains bisphenol A as a glycol component. It contains part or all of an alkylene oxide adduct. As the alkylene oxide, ethylene oxide, propylene oxide, butylene oxide, etc. can be used. Further, the number of moles of these alkylene oxides added can be selected in the range of 2 to 30 moles per mole of bisphenol A, and a range of 4 to 20 moles is particularly desirable from the viewpoint of imparting the desired room-temperature punchability. The content of the alkylene oxide adduct of bisphenol A in the glycol component is preferably 30% by weight or more, more preferably 50% by weight or more. Examples of glycol components that can be used in conjunction with the alkylene oxide adduct of bisphenol A include ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol, and dipropylene glycol.

On the other hand, polybasic acid components that react with these glycol components to produce polyester resins include unsaturated polybasic acids such as fumaric acid, maleic anhydride, and itaconic acid, and/or phthalic anhydride, isophthalic acid, terephthalic acid, Saturated polybasic acids such as adipic acid can be used, and unsaturated polybasic acids are particularly preferred because they contain unsaturated bonds in the polyester molecular chain that can serve as crosslinking points with the phenol resin. Preferred polybasic acids include 30% by weight or more of ethylenically unsaturated dibasic acids or their acid anhydrides;
Preferably, it is used in an amount of 50% by weight or more.

As the phenolic resin that can be used in the present invention,
For example, novolac-type phenolic resins or resol-type phenolic resins can be mentioned, and resol-type phenolic resins, especially resins modified with alkylphenols, drying oils, epoxidized drying oils, etc., can be preferably used for laminated board applications.

The polyester resin in the present invention is added to the phenol resin as it is or dissolved in an organic solvent such as toluene, xylene, methanol, or acetone. The amount added is 1 to 10 parts by weight, more preferably 2 to 30 parts by weight of the polyester resin per 100 parts by weight of the phenol resin. If the amount added is less than 1 part by weight, the plasticizing effect is small and the desired improvement in low-temperature punchability cannot be achieved, which is not preferable. Moreover, when it exceeds 40 parts by weight, the crosslinking density decreases,
This is not preferable because the mechanical properties and electrical properties of the cured product are impaired.

This phenolic resin composition can also contain other known additives for the purpose of further improving properties such as flame retardancy. For example, antimony compounds such as antimony trioxide, halogen-containing compounds such as chlorinated paraffin, halogenated phenols, and halogenated epoxy compounds, phosphorus-containing compounds such as triphenyl phosphate, talesyl diphenyl phosphate, and tricresyl phosphate. Nitrogen-containing compounds such as , melamine, and benzoguanamine can be mentioned as additives for improving flame retardancy.

Furthermore, inorganic substances such as asbestos, mica, talc, clay, and kaolin can be added for the purpose of improving heat resistance, electrical properties, water resistance, and the like.

The phenolic resin composition thus obtained can be made into a laminate by impregnating and curing a paper base material such as kraft paper or linter paper, a nonwoven fabric, or a base material such as glass fiber cloth. It is also possible to apply it to other uses such as molded products within the range where flexibility can be effectively utilized.

〔Effect of the invention〕

The polyester resin used in the present invention has excellent compatibility with phenolic resin, and the phenolic resin composition containing it can be molded into a laminate using a normal method to give a laminate with excellent flexibility, and can be used at room temperature. Punching can be performed without cracks or peeling in the vicinity. Furthermore, since the heat resistance, solvent resistance, electrical properties, etc. inherent to phenol resins are not impaired, they can be suitably used as printed circuit boards and insulating substrates.

〔Example〕

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

Example 1 Bisphenol A was reacted with propylene oxide under an alkali catalyst to obtain a bisphenol A propylene oxide adduct having an average number of moles of 16 moles. This was reacted with maleic anhydride in equimolar amounts to obtain a polyester resin (resin-A) having an acid value of 14.

On the other hand, a phenolic resin modified with tung oil was synthesized, and the solid content was 55%.
Dissolve it in toluene so that it becomes, and then add and dissolve resin-A to obtain a phenol resin solid content: resin-A = 90:10.
(weight ratio).

Next, the fabric was impregnated with kraft paper according to a conventional method and dried to obtain a prepreg with an adhered resin content of 50 wt %. A predetermined number of sheets were stacked together and heated to 160°C.

Heat pressed for 60 minutes at a pressure of 80 kg/cm.
Thickness 1. A laminate of 1000 m was obtained.

Table 1 shows the properties of this laminate.

Example 2 A bisphenol A propylene oxide adduct with an average added mole number of 8 moles was obtained in the same manner as in Example 1, and equimolar amounts of this were reacted with fumaric acid to obtain a polyester resin (resin-B) with an acid value of 12. Ta.

The same tung oil modified phenol resin as in Example 1 and Resin-B were dissolved and mixed in toluene at a weight ratio of 80:20 to prepare a resin face.

This was processed into a laminate in the same manner as in Example 1. Table 1 shows the properties of this laminate.

Example 3 A bisphenol A ethylene oxide adduct with an average addition mole number of 2 moles was obtained in the same manner as in Example 1, and the adduct was mixed with propylene glycol, fumaric acid, and adipic acid at a molar ratio of 0.7.
: 0.3 : 0.8 : 0.2 to obtain a polyester resin (resin-○) having an acid value of 10.

A resin varnish was prepared by dissolving and mixing the same tung oil-modified phenol resin and Resin-C as in Example 1 in toluene at a weight ratio of 85:15.

This was processed into a laminate in the same manner as in Example 1. Table 1 shows the properties of this laminate.

Comparative Example 1 A laminate was obtained in the same manner as in Example 1 using only a tung oil-modified phenolic resin that did not contain the polyester resin according to the present invention.

Table 1 shows the physical properties of this laminate.

Table 1 (Note) Punching workability was evaluated based on ASTM D-617, and other items were evaluated based on JIS C-6481.

Claims (1)

[Claims] 1. A polyester resin obtained by using an alkylene oxide adduct of bisphenol A as part or all of the glycol component and reacting it with a polybasic acid in an amount of 1 to 1 to 1 parts by weight per 100 parts by weight of the phenol resin. A phenolic resin composition containing 40 parts by weight. 2. The phenol resin composition according to claim 1, wherein part or all of the polybasic acid is an ethylenically unsaturated dibasic acid or an acid anhydride thereof. 3. The phenol resin composition according to claim 1, wherein the polybasic acid is fumaric acid or maleic anhydride.