Abstract: A chlorinated vinyl chloride resin composition comprising 100 parts by weight of chlorinated vinyl chloride resin and a hydroxypolycarboxylic acid salt, e.g., sodium tartrate, and/or 0.2 to 1.5 parts by weight of zeolite. The composition exhibits improved thermal stability and is particularly suited to pipe extrusion.

Abstract: A method for forming a recognition mark on the back surface of a substrate for a KGD that can be easily produced while manufacturing cost is low and permits repeated use of a substrate is provided. In the method, wiring patterns are formed on a surface of one side of an insulating substrate. The method includes step of forming a conductive pattern as a recognition mark on one surface where the wiring patterns are formed, and step of forming a through hole from a surface where the wiring pattern is not formed toward the conductive pattern. In the substrate, bumps connected with the KGD are formed on the surface on which the wiring patterns are not formed. Also, the conductive pattern may have a shape as the recognition mark or the through hole may have the shape as the recognition mark.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, the floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.

Abstract: A chlorinated vinyl chloride resin composition containing a chlorinated vinyl chloride resin which has a polymerization degree of from 600 to 1500 prior to chlorination and a chlorination degree of from 62 to 70 wt. %, an impact modifier, a stabilizer, a lubricant and titanium dioxide, wherein the content of zinc in titanium dioxide is 0.1% or less, which has improved thermal stability.

Abstract: A chlorinated vinyl chloride resin composition containing a chlorinated vinyl chloride resin which has a polymerization degree of from 600 to 1500 prior to chlorination arid a chlorination degree of from 62 to 70 wt. %, an impact modifier, a stabilizer, a lubricant and titanium dioxide, wherein the content of zinc in titanium dioxide is 0.1% or less, which has improved thermal stability.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, the floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.

Abstract: In producing chlorinated polyvinyl chloride resin having chlorination degree of 60-73% by weight, wherein polyvinyl chloride resin is suspended in an aqueous medium and chlorine gas is blown into said suspension under beam of a mercury lamp in the temperature range of 40-90° C., an organic peroxide compound having a 10 hour half-life in the range of 40-90° C. is added into the reaction vessel in the ratio of 0.01-1 parts to 100 parts of the polyvinyl chloride resin by weight before the chlorination reaction is started. By this method, the time for chlorination reaction can be shortened without sacrificing the initial coloring and the heat stability, whereby chlorinated polyvinyl chloride can be produced with significantly improved productivity.

Abstract: A chlorinated vinyl chloride resin composition, which is suitably used for the production of extruded pipes, containing a chlorinated vinyl chloride resin which has a polymerization degree of from 600 to 1500 prior to chlorination and a chlorination degree of from 62 to 70 wt. %, methyl methacrylate-butadiene-styrene copolymer particles having a butadiene content of less than 60 wt. % and a styrene content of larger than 30 wt. % in the whole particles, and a chlorinated polyethylene having a chlorine content of from 10 to 50 wt. %, in which the methyl methacrylate-butadiene-styrene copolymer particles have an average dispersed particle size of 2,000 angstroms or less in an extruded pipe produced from the composition.