Chlorinated polyvinyl chloride compound having excellent physical, chemical resistance and processing properties

An article formed from CPVC compound which meets or exceeds ASTM D 1784 cell class 23447, has a hydrostatic design basis or 1,000 psi-hs according to ASTM D 2837 at approximately 2.000 hours of testing at 203° F. and when the compound is formed into plaques, has a heat deflection temperature measured according to ASTM D 648 at 264 psi of about at least 250° F. wherein said compound comprises a CPVC resin formed by a two-step process in an aqueous suspension comprising in the first step chlorinating granular microporous polyvinyl chloride having a chlorine content of about 57% at a starting temperature in the range of 30° to 75° C. in the absence of liquid chlorine and free oxygen, but in the presence of at least a stoichiometric amount of chlorine, but less than 10% excess over that required to produce the CPVC end product and a catalytic amount of organic peroxy catalyst sufficient to produce the first step CPVC having an intermediate Cl level of chemically bound chlorine in the range of 64 to 72% by weight, said peroxy catalyst having a 10 hour half life in the range of 30° to 130° C. and in a second step further chlorinating the CPVC formed in the first step, in the presence of at least a stoichiometric amount of chlorine but less than 10% excess over that required to produce the CPVC end product at a temperature in the range of 90° to 130° C. and having a chlorine content of 67 to 75%;

• a chlorinated polyethylene and an impact modifier chosen from the group consisting essentially of acrylic modifier chosen from the group consisting essentially of acrylic impact modifiers, methacrylate-butadiene-styrene impact modifiers, or acrylonitrile-butadiene-styrene impact modifiers and mixtures thereof.