Ips Corporation

Rashid H Siddiqi

Naresh D Patel

Edward D Otremba

Novel low VOC solvent-based adhesives are provided, comprising a mixture of low vapor pressure, isomeric dimethyl-2-piperidones (DMPD) blended with (1) a non-solvent diluent, specifically, acetone (a VOC-exempt compound), or with mixtures of acetone and other known ketonic solvents such as methyl ethyl ketone (MEK), diethyl ketone (DEK), methyl propyl ketone (MPK), and methyl iso-butyl ketone (MIBK), cyclohexanone, and (2) thermoplastic PVC or CPVC resins. Omission of the resin provides a novel primer for pipes. The blended mixture yields PVC or CPVC pipe adhesives and primers that: (1) result in low VOC formulas (e.g., less than 510 g/l for PVC pipe and less than 490 g/l for CPVC pipe); (2) are very economical in the industry; (3) yield strong, quick setting, durable pipe joints that meet the required standards and performance criteria (e.g., ASTM D-2564 lap shear for PVC); (4) yield stable, low viscosity solutions that, in the case of adhesives, can be readily adjusted with thixotropes (e.g., Aerosil 200) to give desirable flow characteristics and body, as well as primers for solvent welding PVC and CPVC pipe and components; and (5) can be formulated with minimal (10 wt %) or no cyclic ethers such as THF.

Low VOC (volatile organic compounds), dimethyl-2-piperidone solvent-based, PVC and CPVC pipe and component adhesives and primers containing minimal or no tetrahydrofuran

CPVC adhesives for joining CPVC substrates, pipes and articles are provided which comprise (a) about 5 to about 25 wt. % CPVC resin, (b) about 20 to about 90 wt. % of a single pentanone or blends of pentanones, (c) 0 to about 20 wt. % total heterocyclic solvent, and (d) 0 to about 45 wt. % total of non-heterocyclic solvents other than component (b) (such as MEK, acetone, cyclohexanone, and so forth). The CPVC adhesive compositions of this invention permit a reduction in the content of heterocyclic solvents to be achieved while meeting performance standards applicable to CPVC pipe joining, such as hydrostatic burst strength and hydrostatic sustained pressure test.

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South Pasadena, CA, United States of America

Rashid H Siddiqi