Lightguide preform resin composition, the light guide preform, laminated lightguide preform, a surface light source device for the light guide and the planar light source device

The present invention relates to a low cost form lightguide preform resin composition capable of the light scattering effect is large foam layer by laser irradiation process on the surface of the molded article, and more particularly, the weight average molecular weight containing from 60,000 to 150,000 in which the resin, is 30% thermal weight loss temperature when subjected to a thermal mass measurement from the state of 100 ° C. at a heating rate of 5 ° C. / min 310 ° C. or less in an air, 40% thermal weight loss temperature and the light guide body preform resin composition is a 20% difference thermal mass loss temperature of 7 ° C. or less, or, in the resin and nitrogen under a weight average molecular weight of from 60,000 to 150,000 100 ° C. of state from 5 ° C. / min 90% thermal mass loss temperature resin for lightguide preform containing a silicone compound is less than 650 ° C. 250 ° C. or higher when subjected to a thermal mass measurement at a heating rate of it relates compositions.