Patent ID: 6229096
Filing Date: 2001-05-08
Classification: D21H,H05K,Y10T

Abstract:
A process for producing a nonwoven reinforcement for a printed wiring base board which comprises: producing by wet system paper making, paper stuff comprising (A) a thermotropic crystalline polyester fiber having a melting point 290.degree. C. or higher and (B) a thermotropic crystalline polyester fibrous binder having a melting point lower than 290.degree. C.; heat treating the resultant paper stuff under a non-pressurizing condition to melt and bring the thermotropic crystalline polyester fibrous binder into a form of a film having holes including at least 5 holes/mm.sup.2 each with an area of opening of 400 to 10000 .mu.m.sup.2 and to fix the thermotropic crystalline polyester fiber; and subjecting the thermotropic crystalline polyester fibrous binder to solid-phase polymerization to bring the melting point thereof to 290.degree. C. or higher.