Abstract:
An aromatic-aliphatic copolycarbonate and a process for producing the same which comprises polycondensation of an aromatic dihydroxy compound, such as 1,1-bis(4-hydroxyphenyl)cyclohexane, tricyclo(5.2.1.02,6)decanedimethanol, and a carbonic acid diester in a molten state under heating, wherein the carbonic acid diester has a chlorine content of 20 ppm or lower. The copolycarbonate has improved refractive index, balance of dispersion, and photoelastic constant while retaining high impact resistance, high heat resistance, and excellent hue.
Abstract:
Fe—Cr—Si steel sheet having an excellent corrosion resistance and high toughness and method for manufacturing the same; the amount of Cr is about 10-30 wt %, the total amount of C and N is not more than about 100 ppm and the remainder consists of Fe and incidental impurities; when a cast piece of this steel is subjected to hot rolling to roll into a thickness of not more than about 3 mm, the hot rolled sheet can be subjected to cold rolling or to warm rolling without annealing.
Abstract:
A titanosilicate catalyst and method for preparing the same, comprising primary titanosilicate particles which are combined with one another, wherein the titanosilicate catalyst comprises pores having a pore diameter of from 50 to 300 .ANG.. The inventive catalyst exhibits activity in a hydroxylation reaction of an aromatic compound, or an epoxidation reaction of an olefin, or an ammoximation reaction of a ketone using hydrogen peroxide as an oxidant.