Method of preparing a phenolic aldehyde resin and resin composition for an adhesive system to be applied to glass fibers

Abstract

A method of preparing a thermoplastic, water-soluble, phenolic aldehyde resin and the composition are provided to enhance the flexibility and resistance to compression fatigue breakage of glass fibers to which the resin has been applied. The method involves two steps. In the first step, the phenolic compound and the aldehyde are reacted to less than 100 percent completion in an amount so that the aldehyde to phenolic compound ratio is in the range of about 0.6 to about 1.5 and at an acidic pH and for a period of time equivalent to about 3 hours to about 10 hours when the temperature is in the range of about 55.degree. F. (13.degree. C.) to about 90.degree. F. (32.degree. C.) to produce a resinous mixture. In the second stage the pH of the reaction is adjusted within the range above about 7.0 to about 7.5 and the reaction is continued between the unreacted phenolic compound and aldehyde and resinous mixture to produce a resinous mixture composition that is thermoplastic, and water soluble and has trimer polymer with slight cross-linking and dimer and no higher oligomer polymers. The phenolic aldehyde resin mixture is processed into an adhesive system by combining it with one or more elastomeric latex and various latex additives. The adhesive system is aged and has added to it an amine or ammonia to tie up any unreacted aldehyde. Also additional phenolic compound may be added. The adhesive system is used to coat filamentary materials and the coated filamentary materials are dried to produce reinforcement material for rubber.

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