Abstract: A Xonotlite-reinforced organic polymer composition obtained by mixing (A) an organic polymer and (B) fibrous Xonotlite, in which the fibrous Xonotlite (1) satisfies conditions (a), (b), and (c):(a) 0.1 .mu.m.ltoreq.D.ltoreq.0.4 .mu.m(b) 1 .mu.m.ltoreq.L <5 .mu.m(c) 10.ltoreq.L/D .ltoreq.15wherein D and L represent an average fiber diameter and an average fiber length, respectively, of fibrous Xonotlite (B);(2) has a BET specific surface area of not less than 21 m.sup.2 /g as measured by nitrogen adsorption; (3) has had its surface treated with a surface active agent and/or a coupling agent; and (4) has been formed into granules. The composition exhibits improved mechanical characteristics and improved balance between heat resistance and impact resistance.

Abstract: This invention provides a hybrid yarn obtained by combining the filaments of a carbon fiber and a specific inorganic fiber composed substantially of elements Si, Ti or Zr, C and O having a ratio of tensile modulus of the inorganic fiber to tensile modulus of the carbon fiber in the range of from 0.6 to 1.4. Further, this invention provides a unidirectional prepreg obtained by unidirectionally arranging the hybrid yarn prepared from a carbon fiber and a specific inorganic fiber and impregnated with a thermosetting resin, and provides a laminated material obtained by laminating the prepregs.