Compositions for imparting a translucent optical effect to transparent thermoplastic polymers

Abstract

The invention provides compositions and methods for imparting a translucent optical effect to transparent thermoplastic polymers. The compositions comprise the thermoplastic polymer and 0.01 to 15 parts per hundred by weight (preferably 0.1 to 6, more preferably 0.2 to 5 parts by weight, even more preferably 0.5 to 2 parts by weight, and most preferably 0.5 to 1.5 parts by weight) of at least one particulate, light diffusing material in the form of powders, fibers, whiskers, platelets, flakes, aggregates, agglomerates, and mixtures of these, comprising a average maximum particle size of from about 0.1 microns to about 200 microns (preferably from about 1 to about 100 microns). A first embodiment of the invention comprises a one step method for imparting the translucent optical effect. A second embodiment comprises a two step method, including the use of a concentrate composition. The translucent optical effects are obtainable in a continuum of very smooth to very grainy, depending on the type and concentration of the particles employed.

I claim:  
     
         1 . A composition for imparting a translucent optical effect to a transparent thermoplastic polymer, comprising: 
 (i) 0.01 to 15 parts by weight of a particulate, light diffusing material comprising an average maximum particle size of from about 0.1 microns to about 200 microns, selected from the group consisting of calcium sulfates, talc, silicates, kaolin, silicas, mica flakes, mica platelets, mica pearls, titanates, metal sulfates, metal carbonates, sulfides, metal oxides, borides, wollastonite, basalt, boron, ceramics, single crystal fibers, boron nitrides, naturally occurring calcium carbonates, and mixtures thereof;    (ii) a dispersing agent selected from the group consisting of silicone waxes, fatty acids, metallic salts, ionomer waxes, amide waxes, hydroxy stearates, olefinic waxes, and mixtures thereof; and    (iii) 85 to 99.99 parts by weight of a transparent thermoplastic polymer.    
     
     
         2 . The composition of  claim 1 , wherein the particulate material comprises an average maximum particle size of from about 1 micron to about 100 microns.  
     
     
         3 . The composition of  claim 1 , wherein the particulate material comprises about 0.1 to about 6 parts by weight.  
     
     
         4 . The composition of  claim 1 , wherein the particulate material comprises about 0.2 to about 5 parts by weight.  
     
     
         5 . The composition of  claim 1 , wherein the particulate material comprises about 0.5 to about 2.0 parts by weight.  
     
     
         6 . The composition of  claim 1 , wherein the particulate material comprises about 0.5 to about 1.5 parts by weight.  
     
     
         7 . The composition of  claim 1 , wherein the particulate material is in a form selected from the group consisting of powders, fibers, whiskers, platelets, flakes, aggregates, agglomerates, and mixtures thereof.  
     
     
         8 . The composition of  claim 1 , wherein the transparent thermoplastic polymer is selected from the group of transparent and near transparent grades of thermoplastic polymers consisting essentially of polyolefins, polyethylene, polypropylene, clarified grades of polyethylene, clarified grades of polypropylene, polyethylene terephthalate, glycol-modified polyethylene terephthalate, glycol-modified polycyclo-hexanemethanol terephthalate, acid-modified polycyclo-hexanemethanol terephthalate, polystyrene, styrene acrylonitrile copolymers, styrene butadiene, styrene acrylic ester, acrylonitrile butadiene styrene, acrylo-nitrile styrene acrylic ester, acrylics, polymethacrylo-nitrile, ethylene methylacrylate, polymethylmethacrylate, ethylene ethylacrylate, ethylene butylacrylate, ethylene acrylic ester, cellulose butyrate, polymethylpentene, polyisobutene, polybutene, polyamides, polycarbonate, ionomers, polyurethane, liquid crystal polymers, cellulose propionate, polyvinyl alcohol, ethylene vinyl alcohol, ethylene vinylacetate copolymer, polyvinyl chloride, high density polyethylene, polypropylene, polyacetal, and copolymers, grafts and blends thereof.  
     
     
         9 . The composition of  claim 1 , wherein the transparent thermoplastic polymer is ground to 20 mesh.  
     
     
         10 . The composition of  claim 1 , wherein the transparent thermoplastic polymer is finely ground, finely flaked, finely pelletized, or a mixture thereof.  
     
     
         11 . The composition of  claim 1 , wherein the dispersing agent comprises a bis-stearamide compound.  
     
     
         12 . The composition of  claim 1 , wherein the dispersing agent comprises a hydroxy stearate.  
     
     
         13 . The composition of  claim 1 , wherein the dispersing agent comprises an olefenic wax selected from the group consisting of polyethylene and polypropylene based waxes.  
     
     
         14 . A composition as defined in  claim 1 , wherein the composition further comprises a flow enhancing compound.  
     
     
         15 . The composition of  claim 14 , wherein the composition comprises about 0.1 to about 7 parts by weight of the flow enhancing compound.  
     
     
         16 . The composition of  claim 14 , wherein the flow enhancing compound is selected from the group consisting of fumed silica, precipitated silica, and mixtures thereof.  
     
     
         17 . A composition for imparting a translucent optical effect to a transparent thermoplastic polymer, comprising: 
 0.1 to 15 parts by weight of a substantially homogeneous mixture that comprises 
 (i) 40 to 90 parts by weight of a ground, flaked or pelletized carrier agent selected from the group consisting of a first transparent thermoplastic polymer, a dispersing agent, and mixtures thereof, wherein the dispersing agent is selected from the group consisting of silicone waxes, fatty acids, metallic salts, ionomer waxes, amide waxes, hydroxy stearates, olefinic waxes, and mixtures thereof, and  
 (ii) 10 to 60 parts by weight of a particulate, light diffusing material comprising an average maximum particle size of from about 0.1 microns to about 200 microns, selected from the group consisting of calcium sulfates, talc, silicates, kaolin, silicas, mica flakes, mica platelets, mica pearls, titanates, metal sulfates, metal carbonates, sulfides, metal oxides, borides, wollastonite, basalt, boron, ceramics, single crystal fibers, boron nitride, naturally occurring calcium carbonates, and mixtures thereof;  
   and 85 to 99.9 parts by weight of a second transparent polymer that is chemically compatible with the carrier agent.    
     
     
         18 . The composition of  claim 17 , wherein the particulate material comprises an average maximum particle size of from about 1 micron to about 100 microns.  
     
     
         19 . The composition of  claim 17 , wherein the particulate material comprises about 0.1 to about 6 parts by weight.  
     
     
         20 . The composition of  claim 17 , wherein the particulate material comprises about 0.2 to about 5 parts by weight.  
     
     
         21 . The composition of  claim 17 , wherein the particulate material comprises about 0.5 to about 2 parts by weight.  
     
     
         22 . The composition of  claim 17 , wherein the particulate material comprises about 0.5 to about 1.5 parts by weight.  
     
     
         23 . The composition of  claim 17 , wherein the particulate material is in a form selected from the group consisting of powder, fibers, whiskers, platelets, flakes, aggregates, agglomerates or mixtures thereof.  
     
     
         24 . The composition of  claim 17 , wherein the first and second polymers are the same or different and are independently selected from the group of transparent and near transparent grades of thermoplastic polymers consisting of polyolefins, polyethylene, polypropylene, clarified grades of polyethylene, clarified grades of polypropylene, polyethylene terephthalate, glycol-modified polyethylene terephthalate, glycol-modified polycyclohexanemethanol terephthalate, acid-modified polycyclohexanemethanol terephthalate, polystyrene, styrene acrylonitrile copolymers, styrene butadiene, styrene acrylic ester, acrylonitrile butadiene styrene, acrylonitrile styrene acrylic ester, acrylics, polymethacrylonitrile, ethylene methylacrylate, polymethyl-methacrylate, ethylene ethylacrylate, ethylene acrylic ester, ethylene butylacrylate, cellulose butyrate, polymethylpentene, polyisobutene, polybutene, polyamides, polycarbonate, ionomers, polyurethane, liquid crystal polymers, cellulose propionate, polyvinyl alcohol, ethylene vinyl alcohol, ethylene vinylacetate copolymer, polyvinyl chloride, high density polyethylene, polypropylene, polyacetal, and copolymers, grafts and blends thereof.  
     
     
         25 . The composition of  claim 17 , wherein the carrier agent is finely ground, finely flaked, finely pelletized, or a mixture thereof.  
     
     
         26 . The composition of  claim 17 , wherein the carrier agent comprises a finely ground polymer and the composition further comprises 0 to 20 parts by weight of the dispersing agent.  
     
     
         27 . The composition of  claim 17 , wherein the carrier agent comprises a mixture of 80 to 98 parts by weight of the first polymer and 2 to 20 parts by weight of the dispersing agent.  
     
     
         28 . The composition of  claim 17 , wherein the carrier agent comprises a bis-stearamide compound.  
     
     
         29 . The composition of  claim 17 , wherein the carrier agent comprises a hydroxy stearate.  
     
     
         30 . The composition of  claim 17 , wherein the carrier agent comprises an olefenic wax selected from the group consisting of polyethylene and polypropylene based waxes.  
     
     
         31 . The composition of  claim 17 , wherein the composition further comprises a flow enhancing compound.  
     
     
         32 . The composition of  claim 31 , wherein the flow enhancing compound is selected from the group consisting essentially of fumed silica, precipitated silica, and mixtures thereof.  
     
     
         33 . The composition of  claim 31 , wherein the composition comprises about 0.1 to about 7 parts by weight of the flow enhancing compound.  
     
     
         34 . A molded, extruded or formed polymer product having a translucent optical appearance, comprising: 
 (i) 0.01 to 15 parts by weight of a particulate, light diffusing material comprising an average maximum particle size of from about 0.1 microns to about 200 microns, selected from the group consisting of calcium sulfates, talc, silicates, kaolin, silicas, mica flakes, mica platelets, mica pearls, titanates, metal sulfates, metal carbonates, sulfides, metal oxides, borides, wollastonite, basalt, boron, ceramics, single crystal fibers, boron nitrides, naturally occurring calcium carbonates, and mixtures thereof;    (ii) a dispersing agent selected from the group consisting of silicone waxes, fatty acids, metallic salts, ionomer waxes, amide waxes, hydroxy stearates, olefinic waxes, and mixtures thereof; and    (iii) 85 to 99.99 parts by weight of a transparent thermoplastic polymer,    wherein the polymer product when measured according to the procedures described in the operating manual of a HazeGard® Plus hazemeter (Byk-Gardner) (referencing ASTM D-1003 and D-1044), exhibits an average translucency as measured by a transmittance that is about 2% to about 65% lower than the transmittance of a polymer part comprising the polymer alone; a haze that is about 900% to about 11,400% higher than the haze of a polymer part comprising the polymer alone; and a clarity that is about 7% to about 95% lower than the clarity of a polymer part comprising the polymer alone, all at a molded part thickness of 30 mils.    
     
     
         35 . The polymer product of  claim 34  wherein the particulate material comprises an average maximum particle size of from about 1 micron to about 100 microns.  
     
     
         36 . The polymer product of  claim 34 , wherein the particulate material comprises about 0.1 to about 6 parts by weight.  
     
     
         37 . The polymer product of  claim 34 , wherein the particulate material comprises about 0.2 to about 5 parts by weight.  
     
     
         38 . The polymer product of  claim 34 , wherein the particulate material comprises about 0.5 to about 2 parts by weight.  
     
     
         39 . The polymer product of  claim 34 , wherein the particulate material comprises about 0.5 to about 1.5 parts by weight.  
     
     
         40 . The polymer product of  claim 34 , wherein the particulate material is in a form selected from the group consisting of powders, fibers, whiskers, platelets, flakes, aggregates, agglomerates, and mixtures thereof.  
     
     
         41 . The polymer product of  claim 34 , wherein the polymer is selected from the group of transparent and near transparent grades of thermoplastic polymers consisting of polyolefins, polyethylene, polypropylene, clarified grades of polyethylene, clarified grades of polypropylene, polyethylene terephthalate, glycol-modified polyethylene terephthalate, glycol-modified polycyclohexanemethanol terephthalate, acid-modified polycyclohexanemethanol terephthalate, polystyrene, styrene acrylonitrile copolymers, styrene butadiene, styrene acrylic ester, acrylonitrile butadiene styrene, acrylonitrile styrene acrylic ester, acrylics, polymethacrylonitrile, ethylene methylacrylate, polymethyl-methacrylate, ethylene ethylacrylate, ethylene acrylic ester, ethylene butylacrylate, cellulose butyrate, polymethylpentene, polyisobutene, polybutene, polyamides, polycarbonate, ionomers, polyurethane, liquid crystal polymers, cellulose propionate, polyvinyl alcohol, ethylene vinyl alcohol, ethylene vinylacetate copolymer, polyvinyl chloride, high density polyethylene, polypropylene, polyacetal, and copolymers, grafts and blends thereof.  
     
     
         42 . A method for imparting a translucent optical effect to a transparent thermoplastic polymer, comprising the steps of: 
 (a) forming a substantially homogeneous mixture comprising (i) 0.01 to 15 parts by weight of a particulate, light diffusing material having an average maximum particle size of from about 0.1 microns to about 200 microns, selected from the group consisting of calcium sulfates, talc, silicates, kaolin, silicas, mica flakes, mica platelets, mica pearls, titanates, metal sulfates, metal carbonates, sulfides, metal oxides, borides, wollastonite, basalt, boron, ceramics, single crystal fibers, boron nitrides, naturally occurring calcium carbonates, and mixtures thereof, (ii) a dispersing agent selected from the group consisting of silicone waxes, fatty acids, metallic salts, ionomer waxes, amide waxes, hydroxy stearates, olefinic waxes, and mixtures thereof; and (iii) 85 to 99.99 parts by weight of at least one transparent thermoplastic polymer; and    (b) molding, extruding or forming the homogeneous mixture to form a translucent molded, extruded or formed polymer product, wherein, after hardening, the polymer product when measured according to the procedures described in the operating manual of a HazeGard® Plus hazemeter (Byk-Gardner) (referencing ASTM D-1003 and D-1044), exhibits an average translucency as measured by a transmittance that is about 2% to about 65% lower than the transmittance of a polymer part comprising the polymer alone; a haze that is about 900% to about 11,400% higher than the haze of a polymer part comprising the polymer alone; and a clarity that is about 7% to about 95% lower than the clarity of a polymer part comprising the polymer alone, all at a molded part thickness of 30 mils.    
     
     
         43 . The method of  claim 42  wherein the particulate material comprises an average maximum particle size of from about 1 micron to about 100 microns.  
     
     
         44 . The method of  claim 42 , wherein the particulate material comprises about 0.1 to about 6 parts by weight.  
     
     
         45 . The method of  claim 42 , wherein the particulate material comprises about 0.2 to about 5 parts by weight.  
     
     
         46 . The method of  claim 42 , wherein the particulate material comprises about 0.5 to about 2 parts by weight.  
     
     
         47 . The method of  claim 42 , wherein the particulate material comprises about 0.5 to about 1.5 parts by weight.  
     
     
         48 . The method of  claim 42 , wherein the transparent thermoplastic polymer is selected from the group of transparent and near transparent grades of thermoplastic polymers consisting of polyolefins, polyethylene, polypropylene, clarified grades of polyethylene, clarified grades of polypropylene, polyethylene terephthalate, glycol-modified polyethylene terephthalate, glycol-modified polycyclohexanemethanol terephthalate, acid-modified polycyclohexanemethanol terephthalate, polystyrene, styrene acrylonitrile copolymers, styrene butadiene, styrene acrylic ester, acrylonitrile butadiene styrene, acrylonitrile styrene acrylic ester, acrylics, polymethacrylonitrile, ethylene methylacrylate, polymethyl-methacrylate, ethylene ethylacrylate, ethylene acrylic ester, ethylene butylacrylate, cellulose butyrate, polymethylpentene, polyisobutene, polybutene, polyamides, polycarbonate, ionomers, polyurethane, liquid crystal polymers, cellulose propionate, polyvinyl alcohol, ethylene vinyl alcohol, ethylene vinylacetate copolymer, polyvinyl chloride, high density polyethylene, polypropylene, polyacetal, and copolymers, grafts and blends thereof.  
     
     
         49 . A method for imparting a translucent optical effect to a transparent thermoplastic polymer, comprising the steps of: 
 (a) forming a substantially homogeneous concentrate mixture comprising (i) 40 to 90 parts by weight of a carrier agent that is ground, flaked, pelletized, or a mixture thereof, selected from the group consisting of a first transparent thermoplastic polymer, a dispersing agent, and mixtures thereof, wherein the dispersing agent is selected from the group consisting of silicone waxes, fatty acids, metallic salts, ionomer waxes, amide waxes, hydroxy stearates, olefinic waxes, and mixtures thereof, and (ii) 10 to 60 parts by weight of a particulate, light diffusing material having an average maximum particle size of from about 0.1 microns to about 200 microns, selected from the group consisting of calcium sulfates, talc, silicates, kaolin, silicas, mica flakes, mica platelets, mica pearls, titanates, metal sulfates, metal carbonates, sulfides, metal oxides, borides, wollastonite, basalt, boron, ceramics, single crystal fibers, boron nitrides, naturally occurring calcium carbonates, and mixtures thereof;    (b) forming a mixture that comprises 0.1 to 15 parts by weight of the concentrate and 85 to 99.99 parts by weight of a second transparent polymer that is chemically compatible with the carrier agent; and    (c) molding, extruding or forming the homogeneous mixture to form a translucent molded, extruded or formed polymer product, wherein, after hardening, the polymer product when measured according to the procedures described in the operating manual of a HazeGard® Plus hazemeter (Byk-Gardner) (referencing ASTM D-1003 and D-1044), exhibits an average translucency as measured by a transmittance that is about 2% to about 65% lower than the transmittance of a polymer part comprising the polymer alone; a haze that is about 900% to about 11,400% higher than the haze of a polymer part comprising the polymer alone; and a clarity that is about 7% to about 95% lower than the clarity of a polymer part comprising the polymer alone, all at a molded part thickness of 30 mils.    
     
     
         50 . The method of  claim 49 , further comprising the step of extruding and pelletizing the concentrate prior to forming the mixture.  
     
     
         51 . The method of  claim 49 , wherein the particulate material comprises an average maximum particle size of about 1 to about 100 microns.  
     
     
         52 . The method of  claim 49 , wherein the particulate material comprises about 0.1 to about 6 parts by weight.  
     
     
         53 . The method of  claim 49 , wherein the particulate material comprises about 0.2 to about 5 parts by weight.  
     
     
         54 . The method of  claim 49 , wherein the particulate material comprises about 0.5 to about 2 parts by weight.  
     
     
         55 . The method of  claim 49 , wherein the particulate material comprises about 0.5 to about 1.5 parts by weight.  
     
     
         56 . The method of  claim 49 , wherein the first and second polymers are the same or different and are independently selected from the group of transparent and near transparent grades of thermoplastic polymers consisting of polyolefins, polyethylene, polypropylene, clarified grades of polyethylene, clarified grades of polypropylene, polyethylene terephthalate, glycol-modified polyethylene terephthalate, glycol-modified polycyclohexanemethanol terephthalate, acid-modified polycyclohexanemethanol terephthalate, polystyrene, styrene acrylonitrile copolymers, styrene butadiene, styrene acrylic ester, acrylonitrile butadiene styrene, acrylonitrile styrene acrylic ester, acrylics, polymethacrylonitrile, ethylene methylacrylate, polymethyl-methacrylate, ethylene ethylacrylate, ethylene acrylic ester, ethylene butylacrylate, cellulose butyrate, polymethylpentene, polyisobutene, polybutene, polyamides, polycarbonate, ionomers, polyurethane, liquid crystal polymers, cellulose propionate, polyvinyl alcohol, ethylene vinyl alcohol, ethylene vinylacetate copolymer, polyvinyl chloride, high density polyethylene, polypropylene, polyacetal, and copolymers, grafts and blends thereof.  
     
     
         57 . The method of  claim 49 , wherein the carrier agent is finely ground, finely flaked finely pelletized, or a mixture thereof.  
     
     
         58 . The method of  claim 49 , wherein the mixture that comprises the concentrate and the second transparent thermoplastic polymer further comprises 0.1 to 7 parts by weight of a flow enhancing compound.  
     
     
         59 . The method of  claim 58 , wherein the flow enhancing compound is selected from the group consisting essentially of fumed silica, precipitated silica, and mixtures thereof.