Patent ID: 8115105

Claim:
A prepreg comprising composite woven cloth composed of mixed spun fiber of quartz glass fiber and polyolefin fiber that are a main part of the cloth and a thermosetting resin composition that gives a cured product having a low thermal expansion coefficient, wherein the thermal expansion coefficient of the cured resin composition at 50 to 100° C. is 50 ppm/° C. or less, wherein the thermosetting resin composition comprises: (i) a curable polyphenylene ether compound; (ii) one member selected from the group consisting of polybutadiene compounds represented by Formula 1, polyfunctional styrene compounds represented by Formula 2, and bismaleimide compounds represented by Formula 3, (In the formula 1, n is an integer of 10 or more, and a weight average molecular weight based on polystyrene conversion in GPC (Gel Permeation Chromatography) is 1000 or more); (In the Formula 2, R denotes hydrogen skeleton, R 1 is hydrogen or a hydrocarbon group having a carbon number of 1 to 20, the R 1 being the same or different, R 2 , R 3 and R 4 are hydrogen or hydrocarbon group having a carbon number of 1 to 6, the R 2 , R 3 and R 4 being the same or different); and In the Formula 3, R 5 represents a hydrocarbon group having a carbon number of 1 to 4, the R 5 being the same or different and I is an integer of 1 to 4); (iii) silicon oxide filler; (iv) a silane coupling agent; and (v) a hydrogenated styrene-butadiene copolymer.