JPS6033127B2 - Production method of oil-modified phenolic resin for laminated products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an oil-modified phenolic resin for laminates.

It has been known that novolac type phenolic resins have better dimensional stability than resol type phenolic resins.

To obtain laminated products using novolac type phenolic resin,
It is common to use a varnish in which hexamine or resol type phenolic resin is mixed with a solution of novolak type phenolic resin dissolved in an organic solvent. However, since it is difficult to completely dissolve hexamine in the varnish solution, there is a drawback that hexamine precipitates over time, especially in dry-drying oil-denatured varnishes.

In addition, when a hexamine-added varnish is heated, the reaction proceeds and the viscosity increases rapidly, which impairs the impregnating properties of the varnish. On the other hand, a method is known in which formaldehyde is added to /borac type phenol resin and reacted in the presence of a hexamine or aqueous ammonia catalyst to form a resol, but in this case, methylenation reaction is likely to occur and the viscosity of the reaction system increases. However, there is a drawback that it becomes difficult to continue the reaction before the methylolation reaction has progressed sufficiently.

High viscosity resins have poor flow, resulting in the resin impregnated into the coating substrate losing its fluidity before the solvent and condensed water cannot be sufficiently removed during the coating process on the substrate. Furthermore, when a metal alkali such as caustic soda, caustic potash, or barium hydroxide is used as a catalyst for the resolization reaction of novolac-type phenolic resin, metal ions remain in the laminate, resulting in a decrease in moisture resistance and electrical insulation. . Furthermore, the method of mixing resol type phenolic resin with /borac type phenolic resin loses the advantages of /borac type phenolic resin. Even in resol-type phenolic resins, which are mainly composed of mononuclear methylol phenols that are commonly used in laminated products, volatile substances such as integrated water and reaction products are often generated during the curing process. The resulting laminate often shrinks and expands due to heating and moisture absorption, causing warping and twisting, and when modified with oil, there is also a problem with compatibility with varnish.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and provide an oil-modified phenolic resin for laminates that has good dimensional stability.

The present invention provides a dry oil obtained by reacting isoprobenylphenol dimer and phenols with drying oil in the presence of an acidic catalyst.
This method is characterized by reacting an oil-phenol adduct with formaldehyde in the presence of an acidic catalyst to form a novolak, and then reacting it in the presence of a tertiary amine catalyst to form a resol.

Examples of the phenols used in the present invention include phenol, cresol, xylenol, butylphenol, octylphenol, nonylphenol, cashew nut oil, and urushiol.

Any acidic catalyst such as an inorganic acid such as hydrochloric acid, sulfuric acid or phosphoric acid, an organic acid such as toluenesulfonic acid or xylene sulfonic acid, or a Lewis acid can be used for the reaction between phenols and drying oil. As the acidic catalyst used in the reaction between the drying oil-phenol adduct and formaldehyde, the inorganic acid or organic acid used in the reaction between the phenol and the drying oil may be used.

The molar ratio of formaldehyde to be reacted in the presence of an acidic catalyst is preferably 0.2 to 0.6 to 1 part of phenol. In addition, during the reaction of the drying oil-phenol adduct and formaldehyde in the presence of an acidic catalyst, it is also possible to add the above-mentioned various phenols as necessary. After converting the drying oil-phenol adduct into novolak, the third
It is reacted with formaldehyde in the presence of a grade amine catalyst to form a resol. The appropriate molar ratio of formaldehydes to be added is 1 to 1.5 to 1 phenol based on the total formaldehyde including the formaldehyde used for novolac formation in the presence of an acidic catalyst. Examples of tertiary amines include trimethylamine, triethylamine, penzyldimethylamine, 2,4,6 tris(dimethylaminomethyl)phenol, 2-methylimidazole, 2-phenylimidazole, 2-ethyl, 4-methylimidazole, etc. is appropriate. After formaldehyde is reacted to a predetermined degree of reactivity using a tertiary amine catalyst, if necessary, a solvent is added after dehydration under reduced pressure to prepare a coating varnish. The oil-modified phenolic resin according to the present invention is produced by impregnating and drying cotton linter paper, kraft paper, etc., and then stacking the required number of sheets, stacking copper foil on one or both sides as necessary, and heating and pressing to form a laminate. Alternatively, obtain a copper-clad laminate.

Furthermore, when impregnating the substrate with the oil-modified phenolic resin according to the present invention, it is also possible to mix a water-dropping phenolic resin initial condensate, or to use a base material pre-impregnated with the initial condensate. Next, examples of the present invention will be described.

Example Isoprobenylphenol dimer 100%, phenol 400%, tung oil 250% para-toluene sulfonic acid 0
．． 7 days were added and reacted at 80 to 8 years for 120 minutes to obtain a tung oil-phenol adduct.

Subsequently, 85% paraformaldehyde was added to
The reaction was carried out at 0-85% for 150 minutes. After lowering the temperature to 60 qo and adding 15 qo of 30% trimethylamine and 263 qo of 85% paraformaldehyde, it was heated to 80-85 qo.
The reaction was carried out for 4 hours. After dehydration under reduced pressure, the mixture was diluted with methanol to obtain an oil-modified phenol resin varnish with a resin concentration of 5% by weight. Kraft paper, which had been undercoated with a water-lacquered phenolic resin initial condensate, was impregnated with the oil-modified phenolic resin varnish and dried to obtain coated paper with a resin adhesion content of 4% by weight. 9 sheets of coated paper and copper foil with adhesive on one side were stacked at a temperature of 1.
6000 and a pressure of 100k9/lump for 60 minutes to obtain a copper-clad laminate having a thickness of 1.6 willow. Comparative Example 1 A reaction was carried out under the same conditions as in Example 1, except that 25% aqueous ammonia was added in place of 30% trimethylamine in Example 1.

25 minutes after the aqueous ammonia was added and the temperature reached 8030, the viscosity of the reaction system suddenly increased, so the reaction was stopped.
The obtained reaction product was a gelled product that did not dissolve in acetone or toluene. Comparative Example 2 500 parts of phenol, 250 parts of tung oil and 0.7 parts of balatoluenesulfonic acid were added and reacted at 80 to 85 DEG C. for 15 minutes to obtain a tung oil-phenol adduct.

The reaction was carried out under the same conditions as in the examples to obtain an oil-modified phenol resin varnish. A copper-clad laminate was obtained using this varnish under the same conditions as in the example. Comparative Example 3 500 parts of phenol, 250 parts of tung oil, and 0.7 parts of balataluenesulfonic acid were added and reacted at 80 to 85 oC for 120 minutes.

Next, 15 minutes of 25% ammonia water and 230 minutes of 85% paraformaldehyde were added, and the mixture was reacted at 80 to 8,500 for 240 minutes. Next, the mixture was dehydrated under reduced pressure and diluted with acetone to obtain an oil-modified phenol resin varnish with a resin concentration of 5% by weight. A copper-clad laminate was obtained using this varnish under the same conditions as in the example. Table 1 shows the performance of the copper-clad laminates of the above Examples and Comparative Examples 2 and 3.

As mentioned above, the oil-modified phenolic resin according to the present invention is
Since the drying oil-phenol adduct is converted into a novolac, a laminate product with little dimensional change due to heating can be obtained.

Claims (1)

[Claims] 1 A drying oil-phenol adduct obtained by reacting isopropenylphenol dimer and phenols with a drying oil in the presence of an acidic catalyst is reacted with formaldehyde in the presence of an acidic catalyst, and then in the presence of a tertiary amine catalyst. A method for producing an oil-modified phenolic resin for laminated products, which is characterized by reacting with.