Abstract: A pressure-sensitive recording material is described, comprising an electron-accepting compound, and at least one of electron-donating colorless dyes represented by formula (I) or formula (II) ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 each represents a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkoxy group, or a halogen atom; and R.sub.9 and R.sub.10 each represents a hydrogen atom or a lower alkyl group, provided that at least one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 represents a lower alkyl group or a lower alkenyl group.

Abstract: A trench excavator capable of excavating a trench of a rectangular section suitable for formation of an underground diaphragm wall. The underground diaphragm walls are now applied as underground structures replacing caissons, rigid foundations for multistory or tower like buildings, underground tanks and the like. In the trench excavator according to the invention, a pair of drum cutters and a ring cutter interposed therebetween form one unit and a plurality of such units are arranged parallel to one another, whereby an unexcavated portion produced between the drum cutters can be cut out by the ring cutter, leaving no unexcavated portion.

Abstract: A molded article having excellent optical characteristics and obtained by injection molding a resin composition of a bis(hydroxyphenyl)alkane polycarbonate resin having an average molecular weight of 12000 to 18000 and containing 0.005 to 0.5 wt %, based on the resin, of a phosphorous ester represented by the general formula, ##STR1## wherein R.sup.1 and R.sup.2 independently represent an alkyl or aryl group, and R.sup.3 represents hydrogen, an alkyl or aryl group, at a resin temperature of 330.degree. to 400.degree. C. and at a mold temperature of 50.degree. to 110.degree. C., and a method for producing such articles.

Abstract: A polyamide based resin composition is prepared mixing a resin composition with a urea compound of the formula: R.sup.2 --NHCONH--R.sup.1 --NHCONH--R.sup.3 wherein R.sup.1 is an aromatic hydrocarbon group and R.sup.2 and R.sup.3 are both aliphatic groups of 8 to 32 carbon atoms, said resin composition being prepared by melt mixing 99 to 40 parts by weight of a polyamide resin and 1 to 60 parts by weight of a modified ethylene copolymer prepared by graft copolymerizing a copolymer of ethylene and an .alpha.-olefin of at least three carbon atoms with an .alpha.,.beta.-unsaturated carboxylic acid or derivative thereof.