Low VOC (volatile organic compounds), solvent-based CPVC pipe adhesives which maintain joint adhesive performance
OwnerNaresh D. Patel, Mark D. Browninventors
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Abstract
A CPVC adhesive for joining CPVC pipes comprises: (a) about 18 to 28 wt % CPVC resin; (b) a high vapor pressure solvent comprising about 15 to 35 wt % tetrahydrofuran and 0 to about 30 wt % methyl ethyl ketone; and (c) a low vapor pressure solvent comprising about 20 to 45 wt % cyclohexanone, 0 to about 30 wt % N-methyl pyrrolidone, and 0 to 10 wt % dibasic esters (a mixture of refined dimethyl esters of adipic, glutaric, and succinic acids). The VOC level of the CPVC adhesive composition of the invention is at or below the allowed maximum value of 450 g/l, yet the adhesive meets or exceeds required performance standards, such as hydrostatic burst strength and hydrostatic sustained pressure test.
Claims18
A chlorinated polyvinyl chloride (CPVC) adhesive for joining CPVC pipes consisting essentially of:
- (a) about 18 to 28 wt % CPVC resin;
- (b) a high vapor pressure solvent consisting essentially of about 15 to 35 wt % tetrahydrofuran and 0 to about 30 wt % methyl ethyl ketone, with the total high vapor pressure solvent concentration not exceeding a maximum concentration of about 55 wt % of said adhesive;
- (c) a low vapor pressure solvent consisting essentially of about 20 to 45 wt % cyclohexanone, 0 to about 35 wt % N-methyl pyrrolidone, and 0 to about 10 wt % of a mixture of at least two refined dimethyl esters selected from the group consisting of adipic, glutaric, and succinic acids, with the total low vapor pressure solvent concentration at least about 20 wt % of said adhesive;
- and
- (d) up to about 8 wt % of at least one component selected from the group consisting of pigments, fillers, thixotropic agents, and stabilizers,
- said adhesive having a volatile organic compound concentration not exceeding 450 g/l.
A method for reducing volatile organic compound emissions from chlorinated polyvinyl chloride (CPVC) pipe adhesives, wherein said adhesive is formulated by combining
- (a) a resin component consisting essentially of about 18 to 28 wt % CPVC resin;
- (b) a high vapor pressure solvent consisting essentially of about 15 to 35 wt % tetrahydrofuran and 0 to about 30 wt % methyl ethyl ketone, with the total high vapor pressure solvent concentration not exceeding a maximum concentration of about 55 wt % of said adhesive;
- (c) a low vapor pressure solvent consisting essentially of about 20 to 45 wt % cyclohexanone, 0 to about 35 wt % N-methyl pyrrolidone, and 0 to about 10 wt % of a mixture of at least two refined dimethyl esters selected from the group consisting of adipic, glutaric, and succinic acids, with the total low vapor pressure solvent concentration at least about 20 wt % of said adhesive;
- and
- (d) up to about 8 wt % of at least one component selected from the group consisting of pigments, fillers, thixotropic agents, and stabilizers,
- said adhesive having a volatile organic compound concentration not exceeding 450 g/l.
Dependencies are inferred from the claim text.