Abstract: The inorganic fiber of this invention comprising as major constituents______________________________________ % by weight ______________________________________ SiO.sub.2 40-50 CaO 0-10 MgO 15-25 Fe.sub.2 O.sub.3 + FeO 0-10 Al.sub.2 O.sub.3 5-15 MnO 2-15 ______________________________________(provided that the total amount of CaO, Fe.sub.2 O.sub.3, FeO and MnO is about 20% by weight) is excellent in alkali- and heat-resistances and is useful as a replacement of asbestos in asbestos-cement boards. Titanium oxide (TiO.sub.2) is contained in natural rocks or slags to be used for the meltable material as an impurity in the amount of about 2% by weight.

Abstract: A process for producing a glass fiber-reinforced molded sheet by impregnating glass fibers with a resin syrup and thereafter hardening the resin syrup with which the glass fibers are impregnated, wherein the resin syrup is 20 to 35% by weight vinyl aromatic hydrocarbon and comprises 25 to 50 parts by weight acrylonitrile-vinyl aromatic hydrocarbon copolymer and 75 to 50 parts by weight acrylic acid, methacrylic acid, methacrylic acid ester, acrylic acid ester or mixtures thereof, the copolymer comprising 10 to 50 parts by weight acrylonitrile and 90 to 50 parts by weight vinyl aromatic hydrocarbon and having a viscosity average molecular weight of 30,000 to 100,000. A process for producing a glass fiber-reinforced resin molded sheet is also disclosed which is more effective than the aforesaid process wherein the acrylonitrile-vinylaromatic copolymer is modified with 0.05 to 0.2 part by weight of a polyfunctional monomer based on a total of 100 parts by weight of acrylonitrile and vinyl aromatic hydrocarbon.