1. Field of the Invention
This invention relates to polymer dispersions in partially alkoxylated polyoxyalkyleneamines, and more particularly relates to dispersions of polymers made from various vinyl monomers in the presence of partially alkoxylated polyoxyalkyleneamines as the dispersing media.
2. Description of the Related Art
Conventional polyols useful in the production of flexible polyurethane foams are usually made by the reaction of a polyhydric alcohol with an alkylene oxide, usually ethylene oxide and/or propylene oxide, to a molecular weight of about 2,000 to 3,000 and above. These polyols are then reacted with polyisocyanates in the presence of water or other blowing agents such as fluorocarbons to obtain polyurethane foams. Polyols have been modified in many ways to improve the properties of the polyurethanes made from them. One common method of modifying polyols involves the use of polymers as the dispersed phase. One variation available entails the polymerization of vinyl monomers such as acrylonitrile and styrene in a polyol media. Another method includes the polymerization of vinyl monomers in polyol-isocyanate addition products. Another involves the preparation of polyurea polymers by the reaction of diamines with diisocyanates in a polyol media.
U.S. Pat. No. 3,008,917 to Park, et al., for example, teaches the addition of an unsaturated liquid monomer such as styrene to a polyester-isocyanate adduct which itself contains vinyl unsaturation. The resulting mixture is then copolymerized through the unsaturated linkages. U.S. Pat. No. 3,304,273 to Stamberger discloses a polymer polyol having radicals reactive with the --N.dbd.C.dbd.O radicals of an organic polyisocyanate (such as polymers of acrylic acid, allyl alcohol, styrene, butadiene, etc.) combined with a large amount of a solvent which also contains radicals reactive with an isocyanate group, but which has little or no ethylenic unsaturation (such as a polyol). U.S. Pat. No. 3,383,351 to Stamberger discloses similar polymer polyols where the dispersed polymers consist of polymerized ethylenically unsaturated monomers such as methacrylonitrile, styrene, etc., particularly copolymers using more than one kind of unsaturated monomer.
U.S. Pat. No. 4,104,236 to Simroth reveals a liquid polymer polyol composition containing 45-90 wt. % of a polyoxypropylene polyol having a molecular weight of at least 1500, and 55 to 10 wt. % of a polymer. The polymer consists of 60 to 90 wt. % polymerized acrylonitrile and 40 to 10 wt % of polymerized styrene. Polyurethane foams having high load-bearing properties and solid polyurethane elastomers having a high modulus were made from these materials. A polymer polyol consisting of 45 to 95 wt. % of a poly(oxypropyleneoxyethylene) polyol having a hydroxyl number of 20 to 60, an oxyethylene cap of 10 to 30 wt. %, an internal oxyethylene content of 5 to 60 wt. % and from 5 to 60 wt. % of a polymerized vinyl monomer (such as a copolymer of styrene and acrylonitrile) is taught in U.S. Pat. No. 4,125,505 to Critchfield, et al. Further, U.S. Pat. No. 4,148,840 to Shah, et al. discloses polymer polyol compositions made by polymerizing one or more ethylenically unsaturated monomers in a polyol.
High resilience urethane foams may be prepared from tolylene diisocyanate and polymer polyol compositions which were made by polymerizing acrylonitrile and vinylidene chloride monomers in polyols, as taught by U.S. Pat. No. 4,214,055 to Seefried, et al. Foams made from the novel polymer polyols showed enhanced loadbearing properties and a decrease in flammability. U.S. Pat. No. 4,226,756 to Critchfield, et al. teaches that polyol/ vinyl polymer blends made by polymerizing acrylonitrile, styrene and/or methyl methacrylate in the presence of polyethylene-polypropylene glycols are useful in producing polyurethanes. Polymer stabilizers made by polymerizing 30:70 acrylonitrile-styrene mixtures with polypropylene glycol monobutyl ether methacrylate are disclosed by U.S. Pat. No. 4,242,249 to Van Cleve, et al. as useful stabilizers for polyol-vinyl monomer reaction products.
U.S. Pat. No. 4,521,581 to Dominguez, et al. discloses a method of making polymer polyols by mixing a relatively low molecular weight liquid polymer of an ethylenically unsaturated monomer with a polyol and crosslinking it in the polyol. U.S. patent application Ser. No. 472,341, now abandoned, describes a method of making polymer prepolymers in which a relatively low molecular weight liquid polymer of an ethylenically unsaturated monomer is mixed with an isocyanate terminated prepolymer and crosslinked in the prepolymer.
U.S. Pat. No. 3,325,421 to Miller, et al. describes polyurea polymer polyols made by reacting diamines with diisocyanate using a polyol as the dispersing media. U.S. Pat. No. 4,539,378 teaches of a vinyl polymer polyol prepared by polymerizing via a free radical reaction a vinyl monomer component having at least one vinyl monomer in the presence of an epoxy resin modified polyol having a molecular weight of 2,000 to 7,000. The free radical-containing polymerization of vinyl monomers using epoxy resin-modified polyols as the reaction media gives polymer polyols which are more effective than conventional polymer polyols in increasing the load-bearing properties of flexible foams. U.S. Pat. No. 4,523,025 to Cuscurida describes polymer polyols made from partially alkoxylated polyoxyalkyleneamines reacted with an organic polyisocyanate in a polyether polyol.
The art cited heretofore primarily discloses variations of the preparation of polymer polyols by a procedure using a polyol as the dispersing media.
U.S. Pat. No. 4,286,074 to Davis, et al. teaches the preparation of copolymer dispersions by the in situ polymerization of an ethylenically unsaturated monomer or mixture of monomers in the presence of a free radical initiator in an amine-terminated polyoxyalkylene polyether polymer. These dispersions were found useful in the preparation of polyurethane foams which have improved tensile strength, elongation, load deflection and tear strength properties.
The materials found to be useful as the dispersing media in this invention are partially alkoxylated polyoxyalkyleneamines. Generally, the partially alkoxylated polyoxyalkyleneamine is prepared by the addition of at least one alkylene oxide to an aqueous polyoxyalkyleneamine as described in U.S. Pat. 4,465,858 to Cuscurida, et al., incorporated by reference herein.