WOA1 - Fast-curing cpvc solvent cement- Google Patents WOA1 - Fast-curing cpvc solvent cement- Google Patents Fast-curing cpvc solvent cementInfo Publication number WOA1 WOA1 PCT/US2013/050636 USW WOA1 WO A1 WO A1 WO A1 US W US W US W WO A1 WO A1 WO A1 Authority WO WIPO (PCT) Prior art keywords amount solvent cpvc cement weight Prior art date 2012-07-18 Application number PCT/US2013/050636 Other languages Inventor Amrit Parhar Forest HAMPTON Original Assignee Oatey Company Priority date (The priority date is an assumption and is not a legal conclusion. Fast Curing CPVC Solvent CementCROSS-REFERENCE TO RELATED APPLICATIONS0001 This non-provisional patent application claims the benefit of U.S. Provisional Application No. 61/672,970, filed July, 18, 2012, the content of which is hereby incorporated by reference as if fully recited herein.TECHNICAL FIELD0002 The present invention is in the field of adhesives and more particularly in the field of solvent cements useful for plumbing applications including drain, waste, vent and pressurized applications.BACKGROUND0003 Many plumbing applications such as drain, waste, vent and pressure pipe applications utilize thermoplastic resin-based plastics due to their ease of manufacture, cost and water and corrosion resistance. However, these plastics often require upgrading or need repair after extended use. When repairs, new installations or upgrades are required, the piping is necessarily taken out of service. While outages for repair or upgrade are unavoidable, the length of these outages can create significant problems for municipalities or businesses with significant plumbing needs such as hotels and hospitals.
Alkohol dan fenol — Presentation Transcript. Lisa Andina, S. Alcohols Classification Primary: carbon with –OH is bonded to one other carbon. Secondary: carbon with –OH is bonded to two other carbons. Galvanized pipes were once common in residential plumbing systems, but pipes made from other materials are now more popular, including copper and plastic. The white PVC pipes you see in outdoor plumbing systems are easy to find and to work with, but they aren't suitable for use with hot water, so when replacing galvanized pipes indoors, the plumbing code requires the use of CPVC instead of PVC.
No matter the underlying cost, when repairs or upgrades are performed, the joints between sections of piping must be secured together.0004 Joints for plastic plumbing and other articles made from molded plastics such as polyvinyl chloride (PVC) or chlorinated polyvinyl chloride (CPVC) are often secured by solvent cements. These solvent cements are conventionally made from a combination of solvents, and resins dissolved in the mixture.0005 Solvent cementing is a process in which thermoplastics, usually amorphous, are softened by the application of a suitable solvent or mixture of solvents, and then pressed together to effect a bond. Many thermoplastic substrates are easier to join effectively by solvent cements than by conventional adhesive bonding. Generally, a small amount of the same resin that makes up the substrate is dissolved in a solvent to form the cement. The inclusion of the resin aids in gap filling, accelerates setting, and reduces shrinkage and internal stresses.0006 For many years, solvent cements have been made for joining CPVC plastic pipe and fittings. The major uses are drain, waste, vent, sewer and potable water conveyance. Plastic pipe has increasingly displaced the traditional materials used for the same purpose such as copper, steel, galvanized metal, cast iron, lead and concrete asbestos pipe.
Plastic pipe has become the material of choice in the home, municipal, and manufacturing industries.0007 ASTM F-493 sets forth the requirements for CPVC solvent cements as containing a minimum of 10% CPVC resin, inert fillers, and the remainder is one or more solvents including THF, CYH, MEK and/or acetone.0008 Pipes and fittings of CPVC are used for applications where, in addition to high internal pressures of up to 5 bar, temperatures in the range from ambient to at least about 95° C. Are encountered.
Solvent cements for pipes and fittings of CPVC contain between 10 and 30% by weight CPVC in combination with suitable solvents, such as tetrahydrofuran, cyclohexanone, methyl ethyl ketone, N-methylpyrrolidone, methylene chloride, acetone, ethyl acetate and the like. The adhesives may contain consistency- generating constituents such as thickeners, thixotropic agents and the like.0009 Conventionally, cyclohexanone has been used in every marketed CPVC solvent cement.
This is due to the perception that cyclohexanone provides benefits that other common solvents do not. Specifically, stronger joints, and extended working time for artisans working with the joint, allowing for a more optimal fit between the pipes making up the joint. 0047 It is clear from Table 2 that the cure times for effective bonding increase with increased testing pressure. There is little difference between the curing times required for each formula at the 100° F/100 psi scenario. However, the differences begin to emerge once pressures higher than 100 psi are required, with formula 2 requiring 50% more cure time at 150 psi.0048 The data is more pronounced for the 140 F tests. Formula 1 requires ¼ the cure time of formula 2 for the 100 psi; ½ the cure time for the 150 psi test as well as significantly lower cure times for the remainder of the tests.
While all of the formulas required longer cure times than formula 1 excepting the 100° F/100 psi test cases, of particular note is the difference between formula 1 and formula 3 at 140° F/250 psi, where formula 3 required an additional week for an effective cure.0049 Overall, the CYH-free formulation disclosed herein (FORMULA 1 ) overcame the conventionally-perceived drawbacks expected of CYH-free solvent cements. The CYH-free formulation, FORMULA 1, achieved high bonding strength as the joints were able to withstand all of the tested pressures and temperatures. Unexpectedly, FORMULA 1 was able to achieve these high joint strengths in shortened cure times.0050 If desired, additional additives may be advantageously included in the compositions. Additives can include lubricants, stabilizers, plasticizers, colorants, pigments, thixotropic agents, polymeric rheology additives and processing aids, etc.
Small amounts of pigments or colorants such as titanium dioxide, carbon black or a dye or other colorant may be added to the adhesive compositions to serve as a guide for uniform mixing and to provide a method of identifying various adhesive compositions.0051 Exemplary stabilizing agents for CPVC formulations include alkyltin compounds such as methyltin, butyltin and octyltin; dialkyltin dicarboxylates; methyltin mercaptides and butyltin mercaptides; dialkyltin bis(alkylmercaptocarboxylate) including di-n-octyltin-S, S'- bis(isooctylmercaptoacetate); butylthiostaunoic acid; etc. Alkyltin stabilizers such as C4 to C6 alkyltin mercaptides are normally preferred. The stabilizers are generally present in amounts of from about 0.05 to 3% by weight. Triphenyl phosphite, BHT (butylated hydroxy toluene), complex calcium and zinc soaps of alkyl carboxylic acids and hydrotalcite can also be used.0052 The compositions of this disclosure are easy to apply, cost effective, and cure within a reasonable period of time without the use of heat, pressure, UV light or extraordinary mechanical devices.