Combination of substituted cyclodextrin compound and activated carbon

Abstract

The invention is a composition that can prevent formation in, or scavenge undesirable organic materials from, a polymer matrix. The composition contains cyclodextrin and particles of activated carbon. The composition can scavenge thermal decomposition products that can be produced during melt processing of a polymer, contaminants inherent in a polymer, or other types of impurities from a polymer matrix that otherwise may elute into the air, a water supply, or an ingestible material such as a food, a drug, or a beverage. Other aspects of the invention are blends of the composition with polymeric materials, methods of making blends, articles containing the composition, and methods of making articles containing the composition.

We claim: 
     
         1 . A masterbatch composition comprising:
 (a) a thermoplastic polymer;   (b) a substituted cyclodextrin compound in an amount corresponding to about 100 to 150,000 parts by weight of substituted cyclodextrin per each one million parts of the composition; and   (c) carbon particles comprising activated carbon in an amount corresponding to about 0.005 to 5,000 parts by weight of carbon particles per each one million parts of the composition,   
       wherein the substituted cyclodextrin has a degree of substitution of about 0.3 to 2.5 and is substantially free of any compound in the central pore of the cyclodextrin ring. 
     
     
         2 . The composition of  claim 1  wherein the cyclodextrin is present in an amount of about 100 parts by weight to 80,000 parts by weight of the cyclodextrin compound per each one million parts of the composition. 
     
     
         3 . The composition of  claim 1  wherein there are about 2 to 40,000 parts by weight of substituted cyclodextrin per each part by weight of activated carbon particles. 
     
     
         4 . The composition of  claim 1  wherein the activated carbon particles are present at about 0.05 to 2000 parts by weight of the carbon particles per each one million parts of the composition. 
     
     
         5 . The composition of  claim 1  wherein the carbon particles comprise acid washed carbon particles. 
     
     
         6 . The composition of  claim 1  wherein the cyclodextrin is β-cyclodextrin. 
     
     
         7 . The composition of  claim 1  wherein the cyclodextrin compound has a substituent substantially on at least one —OH group on the −2 or −6 position of the glucose moiety in the cyclodextrin. 
     
     
         8 . The composition of  claim 7  wherein the cyclodextrin compound comprises a 2-O-Methyl ether. 
     
     
         9 . The composition of  claim 7  wherein the cyclodextrin compound comprises a 6-O-Acetyl ester. 
     
     
         10 . The composition of  claim 1  wherein the cyclodextrin compound comprises a degree of substitution of about 0.5 to 2. 
     
     
         11 . The composition of  claim 1  wherein the activated carbon particles have an average particle size of about 10 nanometers to 100 microns. 
     
     
         12 . The composition of  claim 1 , wherein the thermoplastic polymer is a polyamide, a polycarbonate, a polyurethane, a polyether, a polyketone, polystyrene, a polyacrylate, a polyphenylene oxide, poly(vinyl chloride), or copolymers or blends thereof. 
     
     
         13 . The composition of  claim 1  wherein the thermoplastic polymer is polyester. 
     
     
         14 . The composition of  claim 13  wherein the polyester comprises at least 60% by weight polyethylene terephthalate units and up to 40% by weight other polymers. 
     
     
         15 . The composition of  claim 13  wherein the polyester comprises at least 60% by weight polyethylene naphthalate units and up to 40% by weight other polymers. 
     
     
         16 . The composition of  claim 13  wherein the polyester comprises a copolymer of polyethylene terephthalate/isophthalate and the cyclodextrin is a non-reducing carbohydrate. 
     
     
         17 . The composition of  claim 1  wherein the thermoplastic polymer is a polyolefin. 
     
     
         18 . The composition of  claim 17  wherein the polyolefin comprises polyethylene, polypropylene, or poly(ethylene-co-propylene). 
     
     
         19 . A method of making a masterbatch composition, the method comprising contacting a molten thermoplastic polymer with an additive mixture, said additive mixture comprising:
 (a) a substituted cyclodextrin compound in an amount corresponding to about 100 parts by weight to 150,000 parts by weight of cyclodextrin groups per each one million parts of masterbatch composition, and   (b) carbon particles comprising an activated carbon present in an amount corresponding to about 0.005 parts by weight to 5000 parts by weight per each one million parts of the masterbatch composition,   
       wherein the substituted cyclodextrin has a degree of substitution of about 0.3 to 2.5 and is substantially free of any compound in the central pore of the cyclodextrin ring. 
     
     
         20 . The method of  claim 19  wherein the contacting comprises extrusion blending. 
     
     
         21 . The method of  claim 20  wherein the extrusion blending is followed by the steps of:
 (a) extruding the masterbatch composition to form a polymeric strand; 
 (b) passing the polymeric strand through a water bath; 
 (c) passing the strand through a strand cutter to form a pellet or chip; and 
 (d) drying the pellet or chip. 
 
     
     
         22 . The method of  claim 20  wherein the cyclodextrin is present in an amount of about 200 parts by weight to 80,000 parts by weight of the cyclodextrin compound per each one million parts of the composition. 
     
     
         23 . The method of  claim 20  wherein there are about 2 to 40,000 parts by weight of substituted cyclodextrin per each part by weight of activated carbon particles. 
     
     
         24 . The method of  claim 20  wherein the carbon particles are present at about 0.05 to 2000 parts by weight of the carbon particles per each one million parts of the composition. 
     
     
         25 . The method of  claim 20  wherein the activated carbon particle has an average particle size of about 10 nanometers to 100 micrometers. 
     
     
         26 . A method of making a coated pellet or chip comprising contacting an additive composition with the surface of a thermoplastic pellet or chip, said additive composition comprising:
 (a) a substituted cyclodextrin compound, and   (b) an effective amount of carbon particles comprising activated carbon,   
       wherein the substituted cyclodextrin has a degree of substitution of about 0.3 to 2.5 and is substantially free of a compound in the central pore of the cyclodextrin ring. 
     
     
         27 . The method of  claim 26  wherein the coated pellet or chip comprises about 100 parts by weight to 150,000 parts by weight of the substituted cyclodextrin compound per each one million parts of the coated pellet or chip. 
     
     
         28 . The method of  claim 26  wherein the additive composition comprises about 100 to 80,000 parts by weight of substituted cyclodextrin per each part by weight of activated carbon particles. 
     
     
         29 . The method of  claim 26  wherein the coated pellet or chip comprises about 0.05 to 5000 parts by weight of carbon particles per each one million parts of the coated pellet or chip. 
     
     
         30 . The method of  claim 26  further comprising the step of drying the coated pellet or chip after coating. 
     
     
         31 . A thermoplastic polymeric article comprising:
 (a) a thermoplastic polymer;   (b) a substituted cyclodextrin compound in an amount corresponding to about 10 parts by weight to 50,000 parts by weight of cyclodextrin groups per each one million parts by weight of the article; and   (c) an effective amount of carbon particles comprising activated carbon,   
       wherein the substituted cyclodextrin has a degree of substitution of about 0.3 to 2.5 and is substantially free of any compound in the central pore of the cyclodextrin ring. 
     
     
         32 . The article of  claim 31  wherein the thermoplastic polymer is a polyamide, a polyurethane, a polycarbonate, a polyether, a polyketone, polystyrene, a polyacrylate, a polyphenylene oxide, poly(vinyl chloride), poly(ethylene-co-vinyl alcohol), or copolymers or blends thereof. 
     
     
         33 . The article of  claim 31  wherein the thermoplastic polymer is a polyolefin. 
     
     
         34 . The article of  claim 31  wherein the thermoplastic polymer is a polyester. 
     
     
         35 . The article of  claim 34  wherein the polyester comprises at least 60% by weight polyethylene terephthalate units and up to 40% by weight other polymers. 
     
     
         36 . The article of  claim 34  wherein the polyester comprises at least 60% by weight polyethylene naphthalate units and up to 40% by weight other polymers. 
     
     
         37 . The article of  claim 31  wherein the cyclodextrin is β-cyclodextrin. 
     
     
         38 . The article of  claim 31  wherein the cyclodextrin compound has a substituent substantially on at least one —OH group on the −2 or −6 position of the glucose moiety in the cyclodextrin. 
     
     
         39 . The article of  claim 38  wherein the cyclodextrin compound comprises a 2-O-Methyl ether. 
     
     
         40 . The article of  claim 38  wherein the cyclodextrin compound comprises a 6-O-Acetyl ester. 
     
     
         41 . The article of  claim 31  wherein the cyclodextrin compound comprises a degree of substitution of about 0.5 to 2. 
     
     
         42 . The article of  claim 31  wherein the cyclodextrin is present in an amount of about 100 parts by weight to 25,000 parts by weight per each one million parts of polymer. 
     
     
         43 . The article of  claim 31  wherein there are about 2 to 40,000 parts by weight of substituted cyclodextrin per each part by weight of activated carbon particles. 
     
     
         44 . The article of  claim 31  wherein the activated carbon particles are present at about 0.001 to 500 parts by weight of the carbon particles per each one million parts of the article. 
     
     
         45 . The article of  claim 31  wherein the activated carbon particles are present at about 0.05 to 100 parts by weight of the carbon particles per each one million parts of the article. 
     
     
         46 . The article of  claim 31  wherein the activated carbon particles have an average particle size of about 10 nanometers to 500 nanometers. 
     
     
         47 . The article of  claim 31  wherein the carbon particles comprise acid washed carbon particles. 
     
     
         48 . The article of  claim 32  wherein the thermoplastic polymeric composition has no substantial visible polymer defects nor any substantial discoloration caused by the carbon particles and no carbon particles visible to the unaided human eye. 
     
     
         49 . The article of  claim 32  wherein the thermoplastic polymeric composition has substantially the same stress-strain properties as the thermoplastic polymer without the substituted cyclodextrin and without the carbon particles. 
     
     
         50 . A method of making a thermoplastic article comprising the steps of:
 (a) contacting a treated thermoplastic chip or pellet with an untreated thermoplastic chip or pellet, the treated thermoplastic chip or pellet comprising
 (i) a substituted cyclodextrin in an amount of about 100 parts by weight to 150,000 parts by weight of per each one million parts of the treated chip, and 
 (ii) a carbon particle comprising an activated carbon in an amount of 0.005 to 5000 parts by weight per one million parts of the treated chip; and 
   (b) forming the article,   
       wherein the substituted cyclodextrin has a degree of substitution of about 0.3 to 2.5 and is substantially free of any compound in the central pore of the cyclodextrin ring.