JPS6039287B2 - Manufacturing method of paper-based phenolic resin laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a flame-retardant paper-based phenolic resin laminate with excellent low-temperature punching processability.

Recently, there has been a strong demand for improved durability and low-temperature punching workability (dimensional stability of the substrate due to the ability to perform low-temperature punching) for paper-based phenolic resin laminates. Conventionally, phenolic resin laminates have been cured using halogen compounds such as tetrabromobisphenol A, hexabromophenol, fluorinated epoxy resins, etc., and phosphate compounds such as tricresyl phosphate and cresyl diphenyl phosphate. Flame retardants such as phate, triphenyl phosphate, or nitrogen-containing compounds such as melamine and benzoguanamine are added to or reacted with the phenol resin, either alone or in combination. However, in order to achieve the desired degree of combustion by adding the above-mentioned flame retardant, it is necessary to increase the amount added, which makes the laminate hard and brittle, and reduces punching workability, that is, it is difficult to punch at high temperatures. This resulted in large dimensional shrinkage of the punched product, making it unsuitable as a substrate for automatic insertion of electronic components. Further, there was a drawback that heat resistance, moisture absorption, and electrical properties after water absorption were also deteriorated. Furthermore, when used as a copper-clad laminate, there were also drawbacks such as a decrease in solder resistance and the occurrence of bulges during punching. An object of the present invention is to improve such drawbacks and provide a flame-retardant paper-based phenolic resin laminate that can be used as a substrate for automatic insertion and has excellent low-temperature punching processability.

That is, in the present invention, when manufacturing a paper-based phenolic resin laminate, the phenolic resin has the following general formula: R is 1 carbon number.
The alkyl group R2 of ~4 is characterized by adding the compound (1) represented by CH3 or C25 n=1-3 in an amount of 2-15% by weight in terms of solid content.

In carrying out the present invention, resins that are generally used for paper-based phenolic resin laminates, such as alkylphenol-modified phenolic resins, tung oil-modified phenolic resins, and epoxy-modified phenolic resins, can be used as the phenolic resin. In particular, in the case of tung oil-modified phenolic resin, it has good compatibility with the compound (1), and it is possible that the two may react during heating and pressing during lamination molding, compared to laminates using other phenolic resins. To provide a laminate that has the desired flame retardancy and low-temperature punching workability, has little powder falling during punching, and has a good hole wall finish. The paper base material is impregnated with the resin component in one step, and in two steps, in which the initial condensate of phenol-formaldehyde or melamine-formaldehyde is pre-impregnated and then a general phenol resin is impregnated again. However, the compound (1) of the present invention may be
) may be used in a one-step method, or may be added to the above-mentioned initial condensate and used during preliminary impregnation.

Paper base materials include kraft paper, linter paper, kraft paper,
Paper mixed with linter is used. The compound (1) represented by the above general formula to be added to the phenol resin is an unsaturated vinyl phosphate compound, and for example, as a commercially available product, the product name is Phylor, which has a ratio of R:C4, R2:CH3, and n=1. 76 (manufactured by Stouffer Japan).

The amount added to phenol resin is 2 to 15 in terms of solid content concentration.
A range of % by weight is desirable; if the amount added is less than 2% by weight, the flame resistance effect will be insufficient, and if it exceeds 15% by weight, electrical properties, chemical resistance, etc. will deteriorate. Moreover, although compound (1) can be used alone, it may also be used in combination with other flame retardants such as phosphate ester compounds and nitrogen compounds. The phenol resin to which the compound (1) has been added is soaked into a paper base material, dried, and made into a paper base material.
Let's call it J-preg. This prepreg is laminated in the required number of sheets to a predetermined thickness, and in the case of making a copper-clad laminate, copper foil is further placed on one or both sides, and this is formed by heating and pressure to form the desired paper base material. Obtain a resin laminate. Examples will be described below.

Example 1 8 parts of tung oil-modified phenolic resin were added with 1 part of unsaturated vinyl phosphate (trade name: Phylor 76),
Add a brominated eboxy compound (dibromocresyl monoglycidyl ether) to one part, add a solvent to make a coating varnish, impregnate 10 mils kraft paper with the varnish,
After drying, a prepreg with a resin content of 4% by weight was obtained.

Nine sheets of the prepreg were layered with copper foil on one side and heated to a temperature of 1.
Press molding was carried out for 6 minutes at 60 qo and a pressure of 100 kg/skin to obtain a copper-clad laminate with a thickness of 1.6 skins/skin (invention product 1).
. Example 2 A phenol-formaldehyde initial condensate was blended with 15% by weight of unsaturated vinyl phosphate (trade name: Phylor 76) in terms of solid content, impregnated onto 10 mils kraft paper, and dried until the resin amount was 15% by weight. A pre-impregnated paper was obtained.

Next, 11 parts of tung oil-modified phenolic resin 8$ woven dibromocresilmo/glycidyl ether were added, a solvent was added to form a coating varnish, and the pre-impregnated paper was impregnated with the varnish.
A prepreg having a resin content of 4% by weight was obtained by drying, and the prepreg was molded in the same manner as in Example 1 to obtain a copper-clad laminate (Invention Product 2). Comparative Example Tung oil-modified phenolic resin 8 Etsuro's dibromocresyl monoglycidyl ether was added to form a coating varnish, and using this varnish, a copper-clad laminate was obtained in the same manner as in Example 1. comparison product).

Table 1 shows the characteristics of the invention products 1 and 2 and the comparative product. It shows.

Table 1 Note 1 1. Flame resistance: According to UL-94 method K (V-○, average 5
seconds or less, maximum 10 seconds or less) o Note 1 2. Hot hardness:
Coil hardness tester #935, at 80°C Note-3. Optimal punching temperature: Temperature at which a very good rating is obtained according to ASTM method K. Note that solder heat resistance, insulation resistance, and bending strength are according to JIS method.

Claims (1)

[Claims] 1. When manufacturing a paper-based phenolic resin laminate, the phenolic resin has a general formula ▲ mathematical formula, chemical formula, table, etc. ▼ where R_1 is an alkyl group having 1 to 4 carbon atoms R_2 is CH
The compound (I) represented by _3 or C_2H_5 n=1-3 is 2-15 in terms of solid content concentration.
A method for producing a paper-based phenolic resin laminate, characterized by adding % by weight.