Automobile assembly

Abstract

A method is provided for making an automobile assembly having a moulded plastics structural member and a reinforcing member in which a polymerisable adhesive is employed to bond the two members together and an automobile assembly having a bonded structural member and a reinforcing member. The assembly is suitably used as a “front end carrier” or a bumper system in an automobile.

1 . A method for producing an automobile assembly comprising a structural member made of a moulded plastics material having a low energy surface and a reinforcing member attached to the structural member, the members having complementary surfaces, which comprises applying an adhesive to the complementary surface of the structural member and/or reinforcing member, bringing the complementary surfaces of the reinforcing member and structural member into contact and allowing the adhesive to set so as to bond the structural member and reinforcing member together wherein the adhesive is capable of bonding to a low energy surface plastic.  
   
   
       2 . A method according to  claim 1  in which the low energy surface plastics material has a surface energy of less than 45 mJ/m 2 .  
   
   
       3 . A method according to  claim 1  in which the plastics material comprises a homopolymer selected from a polyolefin, a polystyrene and a polyamide or a copolymer.  
   
   
       4 . A method according to  claim 1  in which the plastics material comprises fibre.  
   
   
       5 . A method according to  claim 4  in which the fibre is selected from short glass fibre, long glass fibre, short natural fibre or long natural fibre.  
   
   
       6 . A method according to  claim 1  in which the plastics material is selected from short glass fibre filled polypropylene, long glass fibre filled polypropylene, glass filled polyamide and glass filled polyamide alloys.  
   
   
       7 . A method according to  claim 1  in which the reinforcement is made of steel and/or aluminium.  
   
   
       8 . A method according to  claim 1  which comprises applying the adhesive directly to the surface of the structural member without treatment or priming of the said surface.  
   
   
       9 . A method according to  claim 1  in which the structural member and reinforcing member are bonded together by a continuum of adhesive along the complementary surfaces on the two members.  
   
   
       10 . A method according to  claim 1  in which the reinforcing member comprises contours or channels which are complementary with the surface of the structural member so as to provide resistance to stress by means of adhesion and/or abutment between the structural and reinforcing member.  
   
   
       11 . A method according to  claim 1  in which the adhesive comprises a polymerisable composition.  
   
   
       12 . A method for producing an automobile assembly comprising a structural member made of a moulded plastics material having a low energy surface and a reinforcing member attached to the structural member, the members having complementary surfaces, which comprises providing an adhesive comprising a polymerisable composition, contacting together the components of the composition under conditions to initiate polymerisation, applying the adhesive to the complementary surface of the structural and/or reinforcing member, bringing the complementary surfaces of the reinforcing member and structural member into contact and curing the adhesive whereby the said members bond together.  
   
   
       13 . A method according to  claim 11  or  claim 12  in which the polymerisable composition comprises an organoborane/amine complex and one or more of monomers, oligomers or polymers having olefinic unsaturation which is capable of polymerisation by free radical polymerisation.  
   
   
       14 . A method according to  claim 13  in which the polymerisable composition further comprises a compound which causes the said complex to disassociate so as to release the organoborane to initiate polymerisation of one or more of monomers, oligomers or polymers having olefinic unsaturation.  
   
   
       15 . A method according to  claim 13  in which the amine part of the organoborane/amine complex is selected from the group of amines having an amidine structural component; aliphatic heterocycles having at least one nitrogen in the heterocyclic ring; primary amines which in addition have one or more hydrogen bond accepting groups wherein there are at least two carbon atoms between the primary amine and the hydrogen bond accepting group; and conjugated imines.  
   
   
       16 . A method according to  claim 15  in which the amine is selected from dimethylaminopropyl amine, methoxypropyl amine, dimethylaminoethylamine, dimethylaminobutylamine, methoxybutyl amine, methoxyethyl amine, ethoxypropylamine, propoxypropylamine, amine terminated polyalkylene ethers (such as trimethylolpropane tris(poly(propyleneglycol), amine terminated)ether), aminopropylmorpholine, isophoronediamine, and aminopropylpropanediamine.  
   
   
       17 . A method according to  claim 13  in which the organoborane part of the organoborane/amine complex is selected from a trialkyl borane and an alkyl cycloalkyl borane.  
   
   
       18 . A method according to  claim 17  in which the organoborane is selected from tri-ethyl borane, tri-isopropyl borane and tri-n-butylborane.  
   
   
       19 . A method according to  claim 13  in which the molar ratio of amine compound to organoborane compound is from 1.0:1.0 to 3.0:1.0  
   
   
       20 . An automobile assembly comprising a structural member made of a moulded plastics material having a low energy surface and a reinforcing member attached to the structural member, the structural member and reinforcing member having complementary surfaces and being attached by means of an adhesive, which is capable of bonding to a low energy surface substrate, on at least part of at least one of the complementary surfaces.  
   
   
       21 . An automobile assembly comprising a structural member made of a moulded glass filled polypropylene and/or glass filled polyamide having a surface energy of less than 45 mJ/m 2 , and a reinforcing member made from a metal selected from steel, zinc and aluminium attached to the structural member, the structural member and reinforcing member having complementary surfaces and being attached by means of an adhesive which is capable of bonding to a substrate having a surface energy of less than 45 mJ/m 2  disposed between at least part of the complementary surfaces so as to bond them together, the adhesive being derived from a polymerisable composition comprising 
 i) a complex between an organoborane and an amine;    ii) one or more of monomers, oligomers or polymers having olefinic unsaturation which is capable of polymerisation by free radical polymerisation; and, optionally    iii) a compound which causes the complex to disassociate so as to release the organoborane to initiate polymerisation of said one or more of monomers, oligomers or polymers having olefinic unsaturation.    
   
   
       22 . An automobile assembly according to any one of claims  20  and  21  for an automobile which has two sides wherein the assembly comprises a front end carrier and the carrier joins the two sides of the automobile together at the front of the automobile and in which the assembly is aligned transversely so as to define a compartment.  
   
   
       23 . An automobile assembly according to any one of claims  20  and  21  wherein the assembly comprises a bumper system in which: 
 i) the reinforcing member is an energy absorbing unit made of metal or plastics material and the structural member is a bumper fascia made of plastics material; or    ii) the reinforcing member is a bumper beam made of metal and the structural member is an energy absorbing unit made of plastics material.    
   
   
       24 . An assembly according to  claim 23  in which the energy absorbing unit defined in part i) or part ii) of  claim 23  has a generally “C” shaped cross section.