Antistatic gloves and process for making same

Abstract

The present invention is directed to antistatic elastomeric articles and methods of making the same. The articles can be single layered or multilayered. The single layered articles possess desirable antistatic properties and desirable properties of comfort and feel. The multilayered articles have an outermost layer/surface that possesses desirable antistatic properties and an innermost layer/surface that exhibits desirable properties of comfort and feel. In preferred embodiments, the elastomeric articles are made form a nitrile/natural rubber blend. Articles of the present invention have antistatic properties measured as having a surface resistivity below about 10 14 Ω/sq and a static decay time of less than about 60 seconds.

1 . An antistatic elastomeric article comprising a non-leachable polymeric antistatic agent and an elastomeric material. 
   
   
       2 . The elastomeric article of  claim 1  wherein the non-leachable polymeric antistatic agent is selected from the group consisting of nitrile rubber, polyurethane, polyvinyl chloride, epichlorohydrin rubber, EPDM-polyaniline copolymer, polyether, polyalkylene oxide, polyalkylene glycol, polybetaine, polyacetylene, polyaniline, copolyesteramide, polyetheramide, polyetheresteramide block copolymer, polythiophene, polyparaphenylene, polyvinyl carbazole, polyglycol diglycidyl ether, polypyrrole, polyfuran, polybenzene, polyphenylene sulfide, salts of polyacrylic acid, polymer electrolyte/ionomers, quaternary polysalts, and ammonium polyphosphate. 
   
   
       3 . The elastomeric article of  claim 1  wherein the elastomeric material is selected from the group consisting of natural rubber, polyisoprene, polychloroprene, plasticized polyvinyl chloride, polybutadiene, butyl rubber, EPD, polyacrylic rubber, polyurethane, halogenated butyl rubber, and styrene-containing block copolymers. 
   
   
       4 . The elastomeric article of  claim 1  wherein the non-leachable polymeric antistatic agent is nitrile rubber and the elastomeric material is natural rubber. 
   
   
       5 . The elastomeric article of  claim 1  comprising between about 51% and about 95% non-leachable polymeric antistatic agent and between about 5% and about 49% elastomeric material. 
   
   
       6 . The elastomeric article of  claim 1  comprising between about 60% and about 90% non-leachable polymeric antistatic agent and between about 10% and about 40% elastomeric material. 
   
   
       7 . The elastomeric article of  claim 1  comprising between about 65% and about 85% non-leachable polymeric antistatic agent and between about 15% and about 35% elastomeric material. 
   
   
       8 . The elastomeric article of  claim 1  comprising about 80% non-leachable polymeric antistatic agent and about 20% elastomeric material. 
   
   
       9 . The elastomeric article of  claim 1  wherein the article is a glove. 
   
   
       10 . The elastomeric article of  claim 1  wherein the article a finger cot. 
   
   
       11 . The elastomeric article of  claim 1  comprising about 80% non-leachable polymeric antistatic agent and about 20% elastomeric material wherein the non-leachable polymeric antistatic agent is nitrile rubber and the elastomeric material is natural rubber. 
   
   
       12 . An antistatic multilayered elastomeric article comprising:
 a) a first layer comprising a blend of a majority of a non-leachable polymeric antistatic agent and a minority of an elastomeric material, and   b) a second layer comprising a blend of a majority of an elastomeric material and a minority of a non-leachable polymeric antistatic agent.   
   
   
       13 . The elastomeric article of  claim 12  wherein the layers do not delaminate upon stretching. 
   
   
       14 . The elastomeric article of  claim 12  wherein the non-leachable polymeric antistatic agent is selected from the group consisting of nitrile rubber, polyurethane rubber, poly vinyl chloride, epichlorohydrin rubber, EPDM-polyaniline copolymer, polyether, polyalkylene oxide, polyalkylene glycol, polybetaine, polyacetylene, polyaniline, copolyesteramide, polyetheramide, polyetheresteramide block copolymer, polythiophene, polyparaphenylene, polyvinyl carbazole, polyglycol diglycidyl ether, polypyrrole, polyfuran, polybenzene, polyphenylene sulfide, salts of polyacrylic acid, polymer electrolyte/ionomers, quaternary polysalts, and ammonium polyphosphate. 
   
   
       15 . The elastomeric article of  claim 12  wherein the elastomeric material is selected from the group consisting of natural rubber, polyisoprene, polychloroprene, plasticized polyvinyl chloride, polybutadiene, butyl rubber, EPD, polyacrylic rubber, polyurethane, halogenated butyl rubber, and styrene-containing block copolymers. 
   
   
       16 . The elastomeric article of  claim 12  wherein the non-leachable polymeric antistatic agent is nitrile rubber and the elastomeric material is natural rubber. 
   
   
       17 . The elastomeric article of  claim 12  wherein the article is a glove. 
   
   
       18 . The elastomeric article of  claim 12  wherein the article is a finger cot. 
   
   
       19 . The elastomeric article of  claim 12 , wherein the article has a surface static resistivity of less than about 10 14  Ω/sq and a static decay time of less than about 60 seconds. 
   
   
       20 . The elastomeric article of  claim 12 , wherein the article has an elastic modulus at 500% elongation of less than about 10 MPa. 
   
   
       21 . The elastomeric article of  claim 12 , wherein the article has an elastic modulus at 500% elongation of less than about 7 MPa. 
   
   
       22 . The elastomeric article of  claim 12 , wherein the article is chlorinated. 
   
   
       23 . The elastomeric article of  claim 12 , further comprising at least one dispersion selected from the group consisting of a sulfur dispersion, a sulfur donor dispersion, a vulcanization accelerator dispersion, a zinc oxide dispersion, an antioxidant dispersion and a titanium dioxide dispersion. 
   
   
       24 . The elastomeric article of  claim 1 , wherein the article has a surface static resistivity of less than about 10 14  Ω/sq and a static decay time of less than about 60 seconds. 
   
   
       25 . The elastomeric article of  claim 1 , wherein the article has an elastic modulus at 500% elongation of less than about 10 MPa. 
   
   
       26 . The elastomeric article of  claim 1 , wherein the article has an elastic modulus at 500% elongation of less than about 7 MPa. 
   
   
       27 . The elastomeric article of  claim 1 , wherein the article is chlorinated. 
   
   
       28 . The elastomeric article of  claim 11 , wherein the article has a surface static resistivity of less than about 10 14  Ω/sq and a static decay time of less than about 60 seconds. 
   
   
       29 . The elastomeric article of  claim 11  wherein the article has an elastic modulus at 500% elongation of less than about 7 MPa. 
   
   
       30 . The elastomeric article of  claim 1  further comprising at least one dispersion selected from the group consisting of a sulfur dispersion, a sulfur donor dispersion, a vulcanization accelerator dispersion, a zinc oxide dispersion, an antioxidant dispersion and a titanium dioxide dispersion. 
   
   
       31 . The elastomeric article of  claim 12 , wherein the first layer is an outer layer of the article. 
   
   
       32 . The elastomeric article of  claim 31 , wherein the outer layer comprises about 80% non-leachable polymeric antistatic agent and about 20% elastomeric material. 
   
   
       33 . The elastomeric article of  claim 12 , wherein the second layer is an inner layer of the article. 
   
   
       34 . The elastomeric article of  claim 32 , wherein the inner layer comprises about 80% elastomeric material and about 20% non-leachable polymeric antistatic agent. 
   
   
       35 . The elastomeric article of  claim 34 , wherein the article has a surface static resistivity of less than about 10 14  Ω/sq and a static decay time of less than about 60 seconds. 
   
   
       36 . The elastomeric article of  claim 35 , wherein the article has an elastic modulus at 500% elongation of less than about 7 MPa. 
   
   
       37 . The elastomeric article of  claim 31 , wherein the outer layer comprises between about 51% and about 95% non-leachable polymeric antistatic agent and between about 5% and about 49% elastomeric material. 
   
   
       38 . The elastomeric article of  claim 37 , wherein the inner layer comprises between about 51% and about 95% elastomeric material and between about 5% and about 49% non-leachable polymeric antistatic agent. 
   
   
       39 . The elastomeric article of  claim 38 , wherein the article has a surface static resistivity of less than about 10 14  Ω/sq and a static decay time of less than about 60 seconds. 
   
   
       40 . The elastomeric article of  claim 31 , wherein the outer layer comprises between about 60% and about 90% non-leachable polymeric antistatic agent and between about 10% and about 40% elastomeric material. 
   
   
       41 . The elastomeric article of  claim 40 , wherein the inner layer comprises between about 60% and about 90% elastomeric material and between about 10% and about 40% non-leachable polymeric antistatic agent. 
   
   
       42 . The elastomeric article of  claim 41 , wherein the article has a surface static resistivity of less than about 10 14  Ω/sq and a static decay time of less than about 60 seconds. 
   
   
       43 . The elastomeric article of  claim 31 , wherein the outer layer comprises between about 65% and about 85% non-leachable polymeric antistatic agent and between about 15% and about 35% elastomeric material. 
   
   
       44 . The elastomeric article of  claim 43 , wherein the inner layer comprises between about 65% and about 85% elastomeric material and between about 15% and about 35% non-leachable polymeric antistatic agent. 
   
   
       45 . The elastomeric article of  claim 44 , wherein the article has a surface static resistivity of less than about 10 14  Ω/sq and a static decay time of less than about 60 seconds. 
   
   
       46 . A process for making an antistatic multilayered elastomeric article having a first layer and a second layer comprising:
 a) preparing a first latex composition by mixing natural rubber latex with nitrile rubber latex, wherein the natural rubber latex in said first latex composition is in a lesser amount than the nitrile rubber latex in said first latex composition,   b) preparing a second latex composition by mixing nitrile rubber latex with natural rubber latex, wherein the nitrile rubber latex in said second latex composition is in a lesser amount than the natural rubber latex in said second latex composition, and   c) forming the first layer from said first latex composition and the second layer from said second latex composition.   
   
   
       47 . The process of  claim 46 , wherein step a) further comprises mechanically mixing the natural rubber latex with the nitrile rubber latex, and wherein step b) further comprises mechanically mixing the nitrile rubber latex with the natural rubber latex. 
   
   
       48 . The process of  claim 47 , wherein step a) further comprises adjusting the first latex composition to a pH of about 9.5. 
   
   
       49 . The process of  claim 47 , wherein step c) further comprises forming a first latex gel from the first latex composition and a second latex gel from the second latex composition. 
   
   
       50 . The process of  claim 46 , wherein step c) further comprises dipping a latex article former a first time into a coagulant solution, dipping the former a second time into the first latex composition, and dipping the former a third time into the second latex composition. 
   
   
       51 . The process of  claim 46 , wherein step c) further comprises vulcanizing the article. 
   
   
       52 . The process of  claim 46 , further comprising a step
 d) chlorinating the article.   
   
   
       53 . The process of  claim 52 , wherein the chlorinating step further comprises:
 inverting the article a first time,   exposing the article to a chlorine solution a first time   inverting the article a second time, and   exposing the article to a chlorine solution a second time.   
   
   
       54 . An antistatic multilayer elastomeric article comprising:
 a) a first layer comprising a synthetic rubber latex and a nitrile rubber latex, the synthetic rubber latex is in a lesser amount than the nitrile rubber latex, and   b) a second layer comprising a nitrile rubber latex and a synthetic rubber latex, the nitrile rubber latex is in a lesser amount than the synthetic latex.   
   
   
       55 . The article of  claim 54  wherein the layers do not delaminate upon stretching. 
   
   
       56 . A process for making an antistatic multilayer elastomeric article having a first layer and a second layer comprising:
 a) preparing a first latex composition by mixing synthetic rubber latex with nitrile rubber latex, wherein the synthetic rubber latex in said first latex composition is in a lesser amount than the nitrile rubber latex in said first latex composition,   b) preparing a second latex composition by mixing nitrile rubber latex with synthetic rubber latex, wherein the nitrile rubber latex in said second latex composition is in a lesser amount than the synthetic rubber latex in said second latex composition, and   c) forming the first layer from the first latex composition and the second layer from the second latex composition.