Processing aids and polymer formulations containing the same and method for producing the same

#This invention relates to a multi-stage emulsion processing aid polymer, a foamable halogenated polymer formulation comprising the processing aid polymer, method of producing processing aids and method of producing the foamable polymer formulation.

#Halogenated polymers such as polyvinyl chloride (“PVC”) are employed as building materials to replace wood in a variety of applications such as house fascia, trim, and decorative molding mill work. “Halogenated polymers” as used herein means (1) homopolymers or copolymers containing greater than 80% of vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride, or combinations and (2) chlorinated polyvinyl chloride, chlorinated polyethylene, or combinations thereof. The most common of these polymers industrially is polyvinyl chloride (PVC) so the general description herein will emphasize PVC and foamed PVC as examples. PVC foam is also used for signage, deck boards, and in the cores of some types of PVC pipe.

#Foamed PVC for these various applications is typically made in a continuous extrusion process. The most common extrusion practices involve free foaming out of the die followed by some type of calibration and the Celuka or integrated skin process. A description of these PVC foaming processes and typical formulation ingredients can be found in D. Klempner. and V. Sendijarevic, “PVC Foams”, Chapter 9, Handbook of Polymeric Foams and Foam Technology, 2nd Ed., Hanser Publishers, Munich, (2004).

#The instant invention is a multi-stage emulsion processing aid polymer, foamable halogenated formulation containing the processing aid polymer, method of producing processing aids and method of producing the foamable halogenated polymer formulations containing the same.

#A first embodiment of the multi-stage emulsion processing aid polymer comprises: from 25 to 75 percent by weight first stage polymer which comprises units derived from non-functional ethylenically unsaturated monomer; and from 25 to 75 percent by weight second stage polymer which comprises 0 to 99.6 mole % units derived from one or more non-functional ethylenically unsaturated monomer(s) and 0.4 to 100 mole % units derived from one or more functionalized ethylenically unsaturated monomer(s) into the emulsion polymerization reactor, wherein the functionality is selected from the group consisting of β-keto esters, β-keto amides, β-diketones, cyanoacetic esters, malonates, nitroalkanes, β-nitro esters, sulfonazides, thiols, thiol-s-triazines, and amine, where the functionality is incorporated into polymers by polymerizing, ethylenically unsaturated monomers containing these functionalities or by post functionalization of a polymer with additional reactions after polymerization; and wherein the processing aid polymer has a Mw equal to or greater than 700,000. In such embodiment, the first stage contains no units derived from functionalized monomers.

#A second embodiment of the multi-stage emulsion processing aid polymer comprises from 25 to 75 percent by weight first stage polymer which comprises 0 to 99.6 mole % units derived from one or more non-functional ethylenically unsaturated monomer(s) and 0.4 to 100 mole % units derived from one or more functionalized ethylenically unsaturated monomer(s) into the emulsion polymerization reactor, wherein the functionality is selected from the group consisting of β-keto esters, β-keto amides, β-diketones, cyanoacetic esters, malonates, nitroalkanes, β-nitro esters, sulfonazides, thiols, thiol-s-triazines, and amine, where the functionality is incorporated into polymers by polymerizing, ethylenically unsaturated monomers containing these functionalities or by post functionalization of a polymer with additional reactions after polymerization; and from 25 to 75 percent by weight second stage polymer which comprises units derived from non-functional ethylenically unsaturated monomer; and wherein the processing aid polymer has a Mw equal to or greater than 700,000. In such embodiment, the second stage contains no units derived from functionalized monomers.