Low moisture permeability laminate construction

Abstract

An article having a fluid permeation prevention layer, such as a pneumatic tire or hose. A tire for example includes an outer tread layer, intermediate sidewall and carcass layers and an innermost air permeation prevention layer: (i) the air permeation prevention (APP) layer having an upper and a lower surface, the layer having a polymer composition exhibiting an air permeation coefficient (APC) of about 25×10 −12 cc cm/cm 2 sec cmHg (at 30° C.) or less and a Young's modulus of about 1 MPa to about 500 MPa, the polymer composition comprising: (A) at least 10 wt % of at least one thermoplastic resin component having an APC of about 25×10 −12 cc cm/cm 2 sec cmHg (at 30° C.) or less and a Young's modulus of more than 500 MPa, which is preferably a polyamide resin or mixture, and (B) at least 10 wt % of at least one elastomer component having an APC of more than about 25×10 −12 cc cm/cm 2 sec cmHg (at 30° C.) and a Young's modulus of not more than 500 MPa, which elastomer component is preferably a halogen-containing rubber or mixture, the total amount (A)+(B) being not less than about 30 wt %, and the elastomer component is a dispersed vulcanized, discontinuous phase in the thermoplastic resin matrix; and (ii) at least one thermoplastic laminate layer bonded to at least said lower surface of the APP layer, the thermoplastic layer comprising a film-forming, semi-crystalline, substantially hydrophobic carbon chain polymer having a glass transition temperature, Tg, of less than about −20° C.

1 . A layered construction comprising at least three layers, one of which layers comprising a fluid permeation prevention layer having an upper and a lower surface; at least one thermoplastic layer in laminate relation with at least said fluid permeation prevention layer lower surface, said thermoplastic layer comprising a film-forming semi-crystalline carbon chain polymer having a glass transition temperature, Tg, of less than about −20° C. and wherein said thermoplastic polymer has an equilibrium water content at 100% relative humidity of less than about 0.1 g per 100 g polymer or a molar water content per polymer structural unit of less than about 0.1; and a layer comprising at least one high diene rubber;
 wherein said fluid permeation prevention layer comprises a polymer composition having an air permeation coefficient of 25×10 −12  cc·cm/cm 2  sec cmHg (at 30° C.) or less and a Young's modulus of 1 to 500 MPa, said layer of said polymer composition comprising: 
 (A) at least 10% by weight, based on the total weight of the polymer composition, of at least one thermoplastic resin component having an air permeation coefficient of 25×10 −12  cc·cm/cm 2  sec cmHg (at 30° C.) or less and a Young's modulus of more than 500 MPa, which resin component is selected from the group consisting of polyamide resins, polyester resins, polynitrile resins, polymethacrylate resins, polyvinyl resins, cellulose resins, fluororesins, and imide resins, and 
 (B) at least 10% by weight, based on the total weight of the polymer composition, of at least one elastomer component having an air permeation coefficient of more than 25×10 −12  cc·cm/cm 2  sec cmHg (at 30° C.) and a Young's modulus of not more than 500 MPa, which elastomer component is selected from the group consisting of diene rubbers and the hydrogenates thereof, halogen-containing rubbers, silicone rubbers, sulfur-containing rubbers, fluoro-rubbers, hydrin rubbers, acryl rubbers, ionomers and thermoplastic elastomers, the total amount (A)+(B) of the component (A) and the component (B) being not less than 30% by weight based on the total weight of the polymer composition, wherein the elastomer component (B) is dispersed in a vulcanized state, as a discontinuous phase, in a matrix of the thermoplastic resin component (A) in the polymer composition. 
 
     
     
         2 . The construction of  claim 1  further comprising a second thermoplastic layer, the thermoplastic of said second thermoplastic layer being the same or different from said first thermoplastic layer and wherein said second thermoplastic layer is in laminate relation with the other of said upper and lower surfaces of said fluid permeation prevention layer. 
     
     
         3 . The construction of  claim 1  wherein: (1) when said construction comprises one thermoplastic layer, said surface of said fluid permeation prevention layer not in contact with said thermoplastic layer further comprises an adhesive composition; and (2) when said construction comprises two thermoplastic layers each having surfaces, a surface of one of said thermoplastic layers not in contact with said fluid permeation prevention layer is in contact with or further comprises an adhesive composition or adhesive layer. 
     
     
         4 . The construction of  claim 1  wherein said thermoplastic layer comprises a polymer selected from the group consisting of homopolymers and copolymers of polyolefins, styrenics, vinyls, acrylics, fluorocarbons, diene polymers and mixtures thereof. 
     
     
         5 . The construction of  claim 1  suitable for use in a tire wherein said layer comprising at least one fluid permeation prevention layer is an innerliner layer and said layer comprising said high diene rubber is a carcass layer or sidewall layer or both. 
     
     
         6 . The construction of  claim 1  wherein said thermoplastic resin component is selected from the group consisting of polyamide resins, polyester resins, polynitrile resins, polymethacrylate resins, polyvinyl resins, cellulose resins, fluororesins, imide resins and mixtures thereof. 
     
     
         7 . The construction of  claim 1  wherein said at least one elastomer component B is selected from the group consisting of natural rubber, synthetic polyisoprene rubber, epoxylated natural rubber, styrene-butadiene rubber (SBR), polybutadiene rubber (BR), nitrile-butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR; ethylene propylene diene monomer rubber (EPDM), ethylene propylene rubber (EPM), maleic acid-modified ethylene propylene rubber (M-EPM), butyl rubber (IIR), isobutylene-aromatic vinyl or diene monomer copolymers, brominated-IIR, chlorinated-IIR, brominated isobutylene p-methylstyrene copolymer, chloroprene rubber, epichlorohydrin homopolymers rubber, epichlorohydrin-ethylene oxide or allyl glycidyl ether copolymer rubbers, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer rubbers, chlorosulfonated polyethylene, chlorinated polyethylene, maleic acid-modified chlorinated polyethylene, methylvinyl silicone rubber, dimethyl silicone rubber, methylphenylvinyl silicone rubber, polysulfide rubber, vinylidene fluoride rubbers, tetrafluoroethylene-propylene rubbers, fluorinated silicone rubbers, fluorinated phosphagen rubbers, styrene elastomers, thermoplastic olefin elastomers, polyester elastomers, urethane elastomers, and polyamide elastomers. 
     
     
         8 . The construction of  claim 4  wherein said thermoplastic is selected from the group consisting of ethylene homopolymers, ethylene copolymers, linear low density polyethylene, high density polyethylene, ethylene-styrene copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer and mixtures thereof. 
     
     
         9 . An article comprising:
 (A) a first layer comprising an elastomer;   (B) a second layer comprising a dynamically vulcanized alloy of an engineering resin and a copolymer of an isoolefin and a para-alkylstyrene, said second layer having fluid permeation prevention properties; and   (C) a substantially hydrophobic thermoplastic layer having an upper and a lower surface and comprising a film-forming, semi-crystalline, substantially hydrophobic carbon chain polymer having a glass transition temperature, Tg, of less than about −20° C.;   wherein said upper or said lower surface of said second layer is adjacent said first layer, and the other of said upper or said lower surface of said thermoplastic layer is adjacent a fluid.   
     
     
         10 . The article of  claim 9  wherein said thermoplastic polymer has an equilibrium water content at 100% relative humidity of less than about 0.1 g per 100 g polymer or a molar water content per polymer structural unit of less than about 0.1. 
     
     
         11 . The article of  claim 9  wherein said thermoplastic layer comprises a polymer selected from the group consisting of homopolymers and copolymers of polyolefins, ethylene homopolymers, ethylene copolymers, styrenics, vinyls, acrylics, fluorocarbons, diene polymers and mixtures thereof. 
     
     
         12 . The article of  claim 9  further comprising an adhesive composition or adhesive layer situated between said substantially hydrophobic thermoplastic layer and said fluid permeation prevention layer. 
     
     
         13 . The article of  claim 12  wherein said adhesive composition or adhesive layer comprises at least one polymer or copolymer selected from the group consisting of maleated ethylene copolymers, epoxidized ethylene copolymers, ethylene ionomers, ethylene acrylate copolymers, ethylene vinyl acetate copolymers and mixtures thereof. 
     
     
         14 . The article of  claim 12  wherein said adhesive layer or adhesive composition is about 1 micron to about 15 microns thick. 
     
     
         15 . The article of  claim 9  substantially in the form of a hose. 
     
     
         16 . A pneumatic tire comprising an outer tread layer, intermediate sidewall and carcass layers and an innermost air permeation prevention layer:
 (i) said air permeation prevention layer having an upper and a lower surface, said layer comprising a polymer composition having an air permeation coefficient of about 25×10 −12  cc cm/cm 2  sec cmHg (at 30° C.) or less and a Young's modulus of about 1 MPa to about 500 MPa, said polymer composition comprising:   (A) at least 10% by weight, based on the total weight of the polymer composition, of at least one thermoplastic resin component having an air permeation coefficient of about 25×10 −12  cc cm/cm 2  sec cmHg (at 30° C.) or less and a Young's modulus of more than 500 MPa, which resin component is selected from the group consisting of polyamide resins, polyester resins, polynitrile resins, polymethacrylate resins, polyvinyl resins, cellulose resins, fluororesins, and imide resins, and   (B) at least 10% by weight, based on the total weight of said polymer composition, of at least one elastomer component having an air permeation coefficient of more than about 25×10 −12  cc cm/cm 2  sec cmHg (at 30° C.) and a Young's modulus of not more than 500 MPa, which elastomer component is selected from the group consisting of diene rubbers and the hydrogenates thereof, halogen-containing rubbers, silicone rubbers, sulfur-containing rubbers, rubbers, fluoro-rubbers, hydrin rubbers, acryl rubbers, ionomers and thermoplastic elastomers, the total amount (A)+(B) of the component (A) and the component (B) being not less than about 30% by weight based on the total weight of said polymer composition, wherein the elastomer component (B) is dispersed in a vulcanized state, as a discontinuous phase, in a matrix of the thermoplastic resin component (A) in said polymer composition; and   (ii) at least one thermoplastic layer in laminate relation with at least said lower surface of said air permeation prevention layer, said thermoplastic layer comprising a film-forming, semi-crystalline, substantially hydrophobic carbon chain polymer having a glass transition temperature, Tg, of less than about −20° C.   
     
     
         17 . A pneumatic tire as claimed in  claim 16 , further comprising an adhesive composition or adhesive layer between said thermoplastic layer and said fluid permeation prevention layer. 
     
     
         18 . A pneumatic tire as claimed in  claim 17 , wherein said adhesive layer comprises at least one polymer selected from the group consisting of ethylene acrylic ester terpolymers comprising at least one of methyl-acrylate, ethyl-acrylate or butyl-acrylate; and at least one of maleic anhydride or glycidyl methacrylate. 
     
     
         19 . The construction of  claim 1 , wherein said layer comprising at least one high diene rubber is located on the upper surface of said fluid permeation prevention layer opposite from said at least one thermoplastic layer.