Abstract: A PTC thermistor capable of ensuring ohmic contact between a PTC thermistor body and an electrode and preventing deterioration in appearance of the thermistor to increase the yields. The PTC thermistor includes a PTC thermistor body, a first electrode formed of plated Ni of 0.2 to 0.7 .mu.m in thickness and a second electrode arranged on the first electrode and mainly formed of metal of low contact resistance. Moisture or water such as a Ni plating solution enters into the PTC thermistor body during formation of the first electrode on the body. The water then bursts due to expansion during baking of the second electrode formed on the first electrode, to produce craters on a surface of the second electrode. A decrease in thickness of the first electrode to a level as small as 0.2 to 0.7 .mu.m facilitates outward discharge of the water to reduce occurrence of the craters.

Abstract: A strand prepreg which comprises (i) a resin composition comprising 100 parts by weight of thermosetting resin having a softening point of 60.degree. C. or less and about 5 to 60 parts by weight of epoxy resin having a number average molecular weight of 5,000 or more and (ii) about 20 to 80% by volume strands of carbon fibers, glass fibers, aromatic polyamide fibers and the like, wherein the strands are impregnated with the resin composition.

Abstract: A process for the preparation of methallyl sulfonic acid and its salt which process comprises the reaction of isobutylene with a complex of sulfur trioxide to form methallyl sulfonic acid and, if desired, neutralization of the formed acid with an alkaline compound to obtain its salt. The sulfur trioxide complex is prepared by a reaction of sulfur trioxide with a mono-alkyl substituted amide of an aliphatic carboxylic acid, which has a tertiary carbon atom bonded directly to the nitrogen atom thereof.