Abstract: A polycarbonate resin composition is given as a mixture of (A) 97-50 wt. % of a polycarbonate resin, and (B) 3-50 wt. % of a graft copolymer. The graft copolymer is obtained by graft-polymerizing 50-95 wt. parts of a monomer selected from (b1) a monomer mixture comprising 60-90 wt. % of an aromatic vinyl monomer, 40-10 wt. % of a vinyl cyanide monomer, and 0-30 wt. % of a monomer copolymerizable with the monomers and (b2) an alkyl methacrylate having an alkyl group including 1-4 carbon atoms in the presence of a latex containing 5-50 wt. parts of a rubber polymer with respect to the total of the monomer and the rubber polymer as 100 wt. parts. The graft copolymer includes a graft-polymerized component having a weight-average molecular weight 50.times.10.sup.4 -300.times.10.sup.4. The polycarbonate resin composition shows a good extrudability and provides a sheet product which exhibits good thermoforming characteristics, such as suppressed drawdown and good deep drawability.

Abstract: A polyvinyl chloride resin pipe is produced for use as an inner lining for repairing or reinforcing sewerage pipes or other existing pipes. An airtight packing is disposed in the resin pipe and between a traction device and a reheating device, with the traction device pulling forwards the resin pipe which has been extruded from an extruder. An internal pressure is imparted to the resin pipe by introducing compressed air from a forward end thereof so that the resin pipe is depressed flat while being reeled up on a drum in such a state that an internal space is maintained without failure within the resin pipe. In use, a heating medium is fed into the resin pipe from its end so that it rapidly becomes soft uniform as a whole, whereby a defect-free inner lining is formed in the existing pipes.

Abstract: A polyvinyl choride resin pipe serves as an inner lining material for the existing pipes. The resin pipe is formed of a resin composition which comprises as a main component either a polyvinyl chloride having a degree of polymerization DP of 600 to 1,050, or a mixture of 40 to 60% by weight of a polyvinyl chloride having a lower average degree of polymerization DP.sub.L of 400 to 600 and 60 to 40% by weight of another polyvinyl chloride having a higher average degree of polymerization DP.sub.H of 1,050 to 1,350. The resin composition further comprises 3 to 25 parts by weight of a modifying agent blended with 100 parts by weight of the main component. The modifying agent is composed of MMA- and/or MBS-modifiers.