Silicone-acrylate impact modifier

Abstract

A silicone-acrylate impact modifier composition, wherein said impact modifier composition comprises structural units derived from: at least one silicone rubber monomer, a branched acrylate rubber monomer having the formula: wherein R 1 is selected from hydrogen and C 1 -C 8 linear and branched hydrocarbyl groups; and R 2 is a branched C 3 -C 16 hydrocarbyl group; a first graft link monomer, a polymerizable alkenyl-containing organic material, and and a second graft link monomer. The silicone-acrylate impact modifier compositions disclosed herein are useful for making molding compositions, which are useful for producing various articles, especially for outdoor applications.

1 . A silicone-acrylate impact modifier composition, wherein said impact modifier composition comprises structural units derived from: 
 at least one silicone rubber monomer,    a branched acrylate rubber monomer having the formula:                          wherein R 1  is selected from hydrogen and C 1 -C 8  linear and branched hydrocarbyl groups; and R 2  is a branched C 3 -C 16  hydrocarbyl group;    a first graft link monomer,    a polymerizable alkenyl-containing organic material, and    and a second graft link monomer.    
     
     
         2 . The impact modifier composition of  claim 1 , wherein R 1  is hydrogen and R 2  is at least one branched hydrocarbyl radical selected from 4-methylpentyl, 4-methylhexyl, and 5-methylhexyl.  
     
     
         3 . The impact modifier composition of  claim 1 , wherein said silicone rubber monomer comprises: 
 at least one cyclic siloxane silicone rubber monomer of the formula:                          wherein R 3  and R 4  are independently selected from hydrogen and C 1 -C 10  alkyl and aryl radicals; and “n” is an integer having a value from about 3 to about 20; and    at least one member selected from a trialkoxysilane and tetraalkoxysilane of the general formula:    (R 5 ) s Si(OR 6 ) 4-s ;    wherein R 5  independently comprises hydrogen and C 1 -C 10  alkyl and aryl radicals; R 6  independently comprises C 1 -C 4  hydrocarbyl radicals; and “s” is an integer having a value from about 0 to about 1.    
     
     
         4 . The impact modifier composition of  claim 1 , wherein said silicone rubber monomer comprises: 
 at least one member selected from octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and hexamethylcyclotrisiloxane; and    tetraethoxysilane.    
     
     
         5 . The impact modifier composition of  claim 1 , wherein said polymerizable alkenyl containing organic material comprises at least one aromatic vinyl monomer, olefinic nitrile; and branched and unbranched (meth)acrylate monomer.  
     
     
         6 . The impact modifier composition of  claim 1 , wherein said polymerizable alkenyl containing organic material is at least one selected from the group consisting of styrene, alpha-methylstyrene, acrylonitrile, methacrylonitrile, butyl acrylate, and methyl methacrylate.  
     
     
         7 . The impact modifier composition of  claim 1 , wherein said first graft link monomer comprises at least one of an (acryloxy)alkoxysilane, a (mercaptoalkyl)alkoxysilane, a vinylalkoxysilane, and an allylalkoxysilane.  
     
     
         8 . The impact modifier composition of  claim 1 , wherein said first graft link monomer comprises at least one of (gamma-methacryloxypropyl)(dimethoxy)methylsilane, (3-mercaptopropyl)alkoxysilane, vinyltrimethoxysilane, and allyltrimethoxysilane.  
     
     
         9 . The impact modifier composition of  claim 1 , wherein said second graft link monomer is at least one polyethylenically, unsaturated compound having at least one allyl group.  
     
     
         10 . The impact modifier composition of  claim 1 , wherein said second graft link monomer is at least one selected from the group consisting of allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, and diallylmaleate.  
     
     
         11 . A silicone-acrylate impact modifier composition, wherein said composition comprises structural units derived from: 
 a silicone rubber monomer comprising octamethylcyclotetrasiloxane and tetraethoxysilane;    a branched acrylate rubber monomer selected from the group consisting of iso-octyl acrylate, 6-methyloctyl acrylate, 7-methyloctyl acrylate, and combinations of the foregoing branched acrylate rubber monomers;    at least one first graft link monomer selected from the group consisting of (gamma-methacryloxypropyl)(dimethoxy)methylsilane and (3-mercaptopropyl)trimethoxysilane;    a polymerizable alkenyl-containing organic material comprising at least one of styrene, alpha-methylstyrene, acrylonitrile, methacrylonitrile, methyl methacrylate; and    at least one second graft link monomer selected from the group consisting of all methacrylate, triallyl cyanurate, and triallyl isocyanurate.    
     
     
         12 . The impact modifier composition of  claim 11 , wherein said impact modifier composition further comprises structural units derived from at least one acrylate monomer selected from the group consisting of linear alkyl acrylates.  
     
     
         13 . A molding composition comprising a polymer resin and a silicone-acrylate impact modifier composition, wherein said impact modifier composition comprises structural units derived from: 
 at least one silicone rubber monomer,    a branched acrylate rubber monomer having the formula:                          wherein R 1  is selected from hydrogen and C 1 -C 8  linear and branched hydrocarbyl groups; and R 2  is a branched C 3 -C 16  hydrocarbyl group;    a first graft link monomer,    a polymerizable alkenyl containing organic material, and    and a second graft link monomer;    wherein said molding composition has ductile-to-brittle transition temperature from about 0° C. to about −60° C.    
     
     
         14 . The molding composition of  claim 13 , wherein said polymer is selected from thermoplastic and thermoset polymers.  
     
     
         15 . The molding composition of  claim 14 , wherein said thermoplastic polymer is selected from the group consisting of polycarbonates, polyesters, polyolefins, polyestercarbonates, polyamides, polyethersulfones, polyetherimides, polyphenylenes ether, acrylate polymers, styrenic polymers, vinyl halide polymers, and blends of the foregoing polymers.  
     
     
         16 . The molding composition of  claim 14 , wherein said thermoplastic polymer is bisphenol A polycarbonate, 1,3-bis(4-hydroxyphenyl)-1-methyl-4-isopropylcyclohexane polycarbonate, polybutylene terephthalate, polyethylene terephthalate, acrylonitrile-styrene-acrylate core shell polymers, acrylonitrile-styrene-alpha-methylstyrene-acrylate core shell polymers, styrene-acrylonitrile copolymer, styrene-methacrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-alpha-methylstyrene-butadiene copolymer, copolymers comprising structural units derived from isophthalic acid, terephthalic acid, resorcinol, and bisphenol A; and blends of the foregoing polymers.  
     
     
         17 . The molding composition of  claim 13 , wherein said impact modifier composition further comprises structural units derived from at least one acrylate monomer selected from the group consisting of linear alkyl acrylates.  
     
     
         18 . An article of manufacture comprising the impact modifier composition of  claim 1 .  
     
     
         19 . The article of  claim 18 , wherein said article comprises outdoor enclosures for electrical and telecommunications interface devices, smart network interface devices, exterior and interior vehicle parts, external housings for garden equipment, and exterior and interior building and construction parts.  
     
     
         20 . The article of  claim 18 , wherein said article comprises exterior and interior automotive parts, window frames, window profiles, gutters, downspouts, siding, automotive bumper, doorliner, tailgate, interior parts, and fender; external housing for garden equipment, and snow scooter.  
     
     
         21 . A molding composition comprising a polymer resin and a silicone-acrylate impact modifier composition, wherein impact modifier composition comprises structural units derived from: 
 a silicone rubber monomer comprising octamethylcyclotetrasiloxane and tetraethoxysilane;    a branched acrylate rubber monomer selected from the group consisting of iso-octyl acrylate, 6-methyloctyl, 7-methyloctyl, and combinations of the foregoing branched acrylate rubber monomers;    at least one first graft link monomer selected from the group consisting of (gamma-methacryloxypropyl)(dimethoxy)methylsilane and (3-mercaptopropyl)trimethoxysilane;    a polymerizable alkenyl-containing organic material comprising at least one of styrene, alpha-methylstyrene, acrylonitrile, methacrylonitrile, methyl methacrylate; and    at least one second graft link monomer selected from the group consisting of allyl methacrylate and triallylcyanurate;    wherein said molding composition has ductile-to-brittle transition temperature from about 0° C. to about −60° C.    
     
     
         22 . The molding composition of  claim 21 , wherein said impact modifier composition further comprises structural units derived from at least one acrylate monomer selected from the group consisting of linear alkyl acrylates.  
     
     
         23 . A method for making a silicone-acrylate impact modifier composition, said method comprising: 
 emulsion polymerizing at least one silicone rubber monomer and a first graft link monomer at a temperature from about 30° C. to about 110° C. to form a silicone rubber latex;    adding to said silicone rubber latex, at a pH of about 4 to about 9.5, and a temperature of about 20° C. to about 90° C., at least one branched acrylate rubber monomer and a second graft link monomer to provide a latex comprising an emulsion polymerized silicone-acrylate rubber hybrid;    grafting said silicone-acrylate rubber hybrid with a polymerizable alkenyl containing organic material to form a graft silicone-acrylate rubber hybrid latex; and,    coagulating, washing, and drying said graft silicone-acrylate rubber hybrid latex to provide said silicone-acrylate rubber impact modifier composition;    wherein said at least one branched acrylate rubber monomer has the formula:                          wherein R 1  is selected from hydrogen and C 1 -C 8  linear and branched hydrocarbyl groups; R 2  is a branched C 3 -C 16  hydrocarbyl group.    
     
     
         24 . The method of  claim 23 , wherein said method further comprises adding to said silicone rubber latex, at least one acrylate monomer selected from the group consisting of linear alkyl acrylates.  
     
     
         25 . The method of  claim 23 , wherein said silicone rubber latex has a volume average particle size from about 100 nanometers to about 2 microns.  
     
     
         26 . The method of  claim 23 , wherein said polymerizable alkenyl containing organic material is at least one selected from the group consisting of styrene, alpha-methylstyrene, acrylonitrile, methacrylonitrile, and methyl methacrylate.