Adhesive composition and method

Abstract

An adhesive composition contains a block copolymer hot melt adhesive and a vapor releasing vapor corrosion inhibitor mixed with the block copolymer hot melt adhesive, the vapor corrosion inhibitor being in the form of particles suspended in the adhesive composition, the particles preferably having a maximum dimension of less than about 30 microns. One improvement results from inclusion in the adhesive mixture of a titanium and/or zirconium containing coupling agent, either separately or as part of the VCI particles. Another improvement results from blending the adhesive mixture in a continuous process using for example a twin screw extruder. As a result, the adhesive mixture has better uniformity and superior viscosity properties during use.

1 . An adhesive composition comprising
 a thermoplastic block copolymer adhesive;   vapor phase corrosion inhibitor(s) in powder format; and   at least one of an organotitanate coupling agent and an organozirconate coupling agent.   
     
     
         2 . A composition according to  claim 1 , wherein the block copolymer adhesive is an ABA block copolymer, wherein A is a styrene homopolymer or copolymer block and B is an ethylene homopolymer or copolymer block. 
     
     
         3 . A composition according to  claim 1 , wherein the block copolymer is an olefin block copolymer. 
     
     
         4 . A composition according to  claim 1 , wherein the powder particles comprise 0.01 to 20% by weight of the vapor phase corrosion inhibitor. 
     
     
         5 . A composition according to  claim 1 , wherein the particles have a diameter of less than 30 microns. 
     
     
         6 . A composition according to  claim 1 , wherein the composition comprises 0.1% to 5% by weight of total titanium (Ti) and zirconium (Zr). 
     
     
         7 . A composition according to  claim 1 , further comprising a tackifying resin. 
     
     
         8 . A composite product comprising a substrate in sheet form and an adhesive composition according to  claim 1  disposed in contact with at least one side of the substrate. 
     
     
         9 . A composite product according to  claim 8 , wherein the substrate is a polymer film. 
     
     
         10 . A composite product according to  claim 8 , wherein the substrate is a nonwoven fabric. 
     
     
         11 . A composite product according to  claim 8 , wherein the substrate is a woven fabric. 
     
     
         12 . A hot melt adhesive composition comprising
 a thermoplastic copolymer adhesive, comprising a multiblock copolymer comprising two or more blocks differing in one or more physical or chemical properties, wherein the blocks are made by polymerizing ethylene and at least one copolymerizable monomer;   a powder dispersed in the adhesive, wherein the powder comprises particles consisting of a chemical compound or compounds that have vapor phase corrosion protection properties, and   a titanate-functional coupling agent and/or a zirconate-functional coupling agent,   
       wherein the composition comprises 0.1% to 5% by weight of total titanium (Ti) and zirconium (Zr), and 
       wherein the average dimension of the powder particles is less than 30 microns. 
     
     
         13 . A composite product comprising a substrate in sheet form and an adhesive composition according to  claim 12  applied on at least one side of the substrate. 
     
     
         14 . A composite product according to  claim 12 , wherein the substrate is a polymer film, a non-woven fabric, or a woven fabric. 
     
     
         15 . A composite product according to  claim 12 , wherein the blocks are made by polymerizing ethylene and a copolymerizable monomer selected from C 3-20  olefins. 
     
     
         16 . A composite product according to  claim 12 , wherein the multiblock copolymer has a polydispersity of 1.0 to 2.9. 
     
     
         17 . A method of manufacturing a hot melt adhesive composition in multiple stages, the method comprising
 in a first stage at a first shear rate, melting an adhesive at a first temperature above 120° C.;   in a second stage, increasing the shear to a second shear rate and reducing the temperature below 120° C.;   in a third stage, adding a powder to the adhesive while maintaining a sufficient shear to maintain the temperature below 120° C. while providing melt flow for a sufficient time to disperse the powder in the adhesive, wherein the powder comprises a carrier and a vapor phase corrosion inhibitor.   
     
     
         18 . A method according to  claim 17 , further comprising, in a fourth stage, adding a tackifying resin 
     
     
         19 . A method according to  claim 17 , further comprising adding a coupling agent selected from the group consisting of organotitanates and organozirconates in the third stage. 
     
     
         20 . A method according to  claim 19 , further comprising, in a fourth stage, adding a tackifying resin. 
     
     
         21 . A method according to  claim 20 , comprising operating at a temperature of 125° C. to 150° C. in the first stage. 
     
     
         22 . A method according to  claim 20 , comprising operating at a temperature of 120° C. to 130° C. in the fourth stage. 
     
     
         23 . A method according to  claim 20 , comprising operating at a temperature of 100° C. or less in the third stage. 
     
     
         24 . A method according to  claim 20 , comprising operating at a temperature of 80° C. or less in the third stage. 
     
     
         25 . A method according to  claim 19 , comprising adding the particles and the coupling agents separately in the third stage. 
     
     
         26 . A method according to  claim 19 , comprising applying the coupling agent onto the particles before the particles are added in the third stage. 
     
     
         27 . A method according to  claim 19 , wherein the composition comprises 0.1% to 5% by weight total titanate and zirconate. 
     
     
         28 . A method according to  claim 17 , wherein the adhesive comprises an ABA block copolymer, wherein A is an ethylene homopolymer or copolymer block and B is an ethylene copolymer block different from A. 
     
     
         29 . A method according to  claim 20 , comprising operating at a temperature of 130° C. to 150° C. in the first stage, at a temperature of 75° C. to 90° C. in the third stage, and at a temperature of 100° C. to 130° C. in the fourth stage. 
     
     
         30 . A method according to  claim 17 , comprising operating at a temperature of less than 105° C. in the third and fourth stage. 
     
     
         31 . A process according to  claim 17 , which is a continuous process. 
     
     
         32 . A method of compounding an adhesive composition in an extrusion apparatus, comprising
 melting an adhesive comprising a block copolymer;   introducing the molten hot melt adhesive into the barrel of the extruder;   cooling the melt below 90° C. while increasing shear in the barrel to maintain sufficient melt flow;   adding a titanate coupling agent and/or a zirconate coupling agent to the melt at a temperature of 90° C. or below;   adding a vapor corrosion inhibitor in particulate form to the melt; and   blending the hot melt adhesive, VCI, and titanate and/or zirconate coupling agent at 90° C. or less until the particles are dispersed in the hot melt adhesive.   
     
     
         33 . A method according to  claim 32 , wherein the block copolymer has blocks produced by copolymerizing ethylene and at least one copolymerizable monomer. 
     
     
         34 . A method according to  claim 33 , wherein the adhesive is an olefin block copolymer with a polydispersity of 1.0 to 2.9. 
     
     
         35 . A method according to  claim 32 , comprising adding the titanate or zirconate coupling agent to the melt at a temperature of 50° C. to 80° C. and blending the hot melt adhesive, VCI, and titanate or zirconate coupling agent at a temperature of 50° C. to 80° C. 
     
     
         36 . A method according to  claim 32 , comprising melting the hot melt adhesive at a temperature of 120° C. to 160° C. 
     
     
         37 . A method according to  claim 32 , further comprising, after the particles are dispersed in the hot melt adhesive, continuing to apply shear at a temperature of 80° C. to 130° C. and adding a tackifying agent. 
     
     
         38 . A method according to  claim 32 , wherein the coupling agent is added at a level to provide a total level of titanium and/or zirconium of 0.1% to 5% by weight in the finished adhesive composition. 
     
     
         39 . A method according to  claim 32 , wherein the coupling agent and the VCI are added separately to the twin screw extruder. 
     
     
         40 . A method according to  claim 32 , wherein the coupling agent and the VCI are added together to the twin screw extruder. 
     
     
         41 . A method according to  claim 32 , comprising combining the VCI and the coupling agent and adding the combination to the melt at a temperature below 90° C. 
     
     
         42 . A composition consisting of a VCI powder and one of an organotitanate coupling agent and an organozirconate coupling agent. 
     
     
         43 . A composition according to  claim 42 , wherein the VCI powder comprises particles that contain 100% by weight vapor phase corrosion inhibitor. 
     
     
         44 . A composition according to  claim 42 , comprising 0.1-5% of the coupling agent, based on the total weight of the composition. 
     
     
         45 . A composition according to  claim 43 , wherein the coupling agent is disposed on the surface of active vapor corrosion inhibiting chemistry. 
     
     
         46 . A composition according to  claim 42 , wherein the coupling agent comprises neopentyl(diallyl)oxy-tri(dodecyl)benzene-sulfonyl titanate (LICA 09). 
     
     
         47 . A composition according to  claim 42 , wherein the coupling agent comprises neopentyl(diallyl)oxy-tri(dioctyl)pyrophosphato titanate (LICA38). 
     
     
         48 . A composition according to  claim 42 , wherein the coupling agent comprises a hydrophobic titanate. 
     
     
         49 . A composition according to  claim 42 , wherein the coupling agent comprises a hydrophilic titanate.