Sealant articles and compositions useful therein

Abstract

A sealant article useful for sealing a substrate surface having a first surface and a second surface is provided. The first surface comprises a deformable composition that is capable of conforming to a substrate surface when subjected to heat and/or pressure. The second surface of the sealant article has been at least partially cured by exposing said surface to an amount of radiation effective to induce at least partial curing of the second surface of the sealant article. Prior to such curing, the second surface also is comprised of the deformable composition. Such at least partial curing is effective to render the second surface less deformable than the first surface.

What is claimed is: 
     
         1 . A deformable composition capable of being cured by exposure to radiation, said deformable composition comprising at least one thermoplastic, at least one (meth)acrylate-functionalized monomer or oligomer, at least one thermally activatable free radical initiator, and at least one filler. 
     
     
         2 . The deformable composition of  claim 1 , additionally comprising at least one tackifier. 
     
     
         3 . The deformable composition of  claim 1 , additionally comprising at least one reactive tackifier. 
     
     
         4 . The deformable composition of  claim 1 , additionally comprising at least one liquid diene homopolymer or copolymer containing pendant vinyl groups. 
     
     
         5 . The deformable composition of  claim 1 , comprising at least one thermally activatable free radical initiator selected from the group consisting of organic peroxides. 
     
     
         6 . The deformable composition of  claim 1 , comprising at least one thermoplastic copolymer of ethylene and at least one comonomer selected from the group consisting of vinyl acetate, (meth)acrylic acid, and C1 to C6 alkyl esters of (meth)acrylic acid. 
     
     
         7 . The deformable composition of  claim 1 , comprising at least one thermoplastic that is an ethylene/vinyl acetate copolymer. 
     
     
         8 . The deformable composition of  claim 1 , additionally comprising at least one photoinitiator. 
     
     
         9 . The deformable composition of  claim 1 , additionally comprising at least one aryl-substituted ketone photoinitiator. 
     
     
         10 . The deformable composition of  claim 1 , comprising at least one (meth)acrylate-functionalized monomer or oligomer selected from the group consisting of epoxy (meth)acrylates and urethane (meth)acrylates. 
     
     
         11 . The deformable composition of  claim 1  comprising, as weight % of total weight of the deformable composition:
 20-45 weight % Ethylene/Vinyl Acetate Copolymer(s) and/or Polyester(s); 
 1-12 weight % liquid Polybutadiene(s) 
 5-30 weight % (Meth)acrylate-Functionalized Monomer(s) and/or 
 Oligomer(s); 
 25-55 weight % Inorganic Particulate Filler(s); 
 0.1-2 weight % Peroxide(s); and 
 0.1-2 weight % Photoinitiator(s). 
 
     
     
         12 . The deformable composition of  claim 11  wherein the (meth)acrylate-functionalized monomer or oligomer is selected from the group consisting of epoxy (meth)acrylates and urethane (meth)acrylates; the epoxy (meth)acrylates essentially all epoxy groups on the epoxy (meth)acrylates being ring-opened, the composition being free of other epoxy compounds 
     
     
         13 . The deformable composition of  claim 1 , comprising, as weight % of total weight of the deformable composition:
 20-45 weight % ethylene/vinyl acetate copolymer(s) and/or polyester(s);   2-6 weight % reactive tackifier;   15-20 weight % epoxy (meth)acrylate(s) and/or urethane (meth)acrylates;   25-55 weight % inorganic particulate filler(s);   0.1-2 weight % peroxide(s);   0.1-2 weight % photoinitiator(s); and   at least one component selected from the group consisting of colorants, pigments, plasticizers, organic acids, anti-oxidants, stabilizers, thixotropic agents, thickeners, reactive diluents, adhesion promoters, coupling agents, radiation absorbers, and radiation blocking agents.   
     
     
         14 . A method of sealing a substrate, said method comprising applying to a substrate surface a deformable composition according to  claim 1 , said deformable composition being a solid having an uncured first surface and a partially cured second surface opposite said first surface, such that said first surface is in at least partial contact with said substrate surface and said second surface faces away from said substrate surface, wherein said first surface is capable of conforming to the substrate surface when subjected to heat and/or pressure and said second surface has been partially cured by exposing said surface to an amount of radiation effective to induce partial curing of said second surface, wherein said partial curing is effective to render said second surface less deformable than said first surface, rendering said second surface capable of substantially limiting said deformable composition to a desired area of said substrate surface when heated to a temperature effective to cause said uncured first surface of the deformable composition to flow. 
     
     
         15 . A method of sealing a substrate, said method comprising applying a solid deformable composition having an uncured first surface and a partially cured second surface, wherein said first surface is capable of conforming to the substrate surface when subjected to heat and/or pressure and said second surface has been partially cured by exposing said surface to an amount of radiation effective to induce partial curing of said second surface, wherein said partial curing is effective to render said second surface less deformable than said first surface to said substrate surface such that said first surface is in at least partial contact with said substrate surface. 
     
     
         16 . The method of  claim 15 , wherein said deformable composition comprising said uncured first surface flows and substantially covers a desired area of said substrate surface when said deformable composition is heated to a temperature effective to cause uncured portions of said deformable composition to flow. 
     
     
         17 . A method of sealing a substrate, said method comprising applying a sealant article having a first surface and a second surface, wherein said first surface is comprised of a deformable composition that is capable of conforming to a substrate surface when subjected to heat and/or pressure and said second surface of said sealant article has been at least partially cured by exposing said surface to an amount of radiation effective to induce at least partial curing of said second surface of said sealant article, wherein said second surface prior to said curing is comprised of said deformable composition and wherein said at least partial curing is effective to render said second surface less deformable than said first surface to said substrate surface such that said first surface is in at least partial contact with said substrate surface. 
     
     
         18 . The method of  claim 17 , comprising an additional step of exerting an amount of pressure on said sealant article effective to conform said first surface more closely to said substrate surface. 
     
     
         19 . The method of  claim 17 , comprising an additional step of heating said sealant article to a temperature effective to cause said first surface to conform more closely to said substrate surface.