Methods for laser welding articles molded from polyolefins to those molded from other thermoplastic resins, and welded articles prepared therefrom

Abstract

Processes for laser welding polyolefin compositions to different thermoplastic resins are disclosed. Such polyolefin compositions comprise 80-99 weight percent of a first polyolefin and 1 to 20 weight percent of a second polyolefin (modified with a carboxylic acid, a carboxylic acid anhydride, and/or an epoxy group), based on the total weight of the polyolefin and modified polyolefin. These compositions can be laser welded to polyamides and polyesters, for example. Additives such as flame retardants, impact modifiers and the like may be incorporated in conventional amounts. Moreover, black colorants may also be selected for use in these compositions for molding transparent articles for laser welding. Laser welded articles made using these processes are also contemplated.

1 . A method for the preparation of laser welded articles of polyolefins and different thermoplastic resins, comprising: 
 (a) blending together 80 to 99 weight percent of a first polyolefin; and 1 to 20 weight percent of a second polyolefin modified with a carboxylic acid, a carboxylic acid anhydride, and/or an epoxy group, based on the total weight of said first polyolefin and said second modified polyolefin;    (b) molding the resulting blend into one or more desired articles;    (c) preparing one or more additional articles of at least one different thermoplastic resin;    (d) positioning said articles (b) and said articles (c) in a desired arrangement, such that they contact one another along common surfaces thereof; and    laser welding said articles (b) to said articles (c) along said common surfaces thereof, wherein either the one or more articles of [b] or the one or more articles [c] at least partially absorbs light at a selective wavelength used for laser welding.    
     
     
         2 . The method according to  claim 1 , wherein said different thermoplastic resin is one or more polyamides.  
     
     
         3 . The method according to  claim 1 , wherein said different thermoplastic resin is one or more polyesters.  
     
     
         4 . The method according to  claim 1 , wherein said first polyolefin comprises a black colorant suitable for molding transparent articles for laser welding.  
     
     
         5 . The method according to  claim 1 , wherein said second polyolefin comprises a black colorant suitable for molding transparent articles for laser welding.  
     
     
         6 . The method according to  claim 1 , wherein said different thermoplastic resin comprises a black colorant suitable for molding transparent articles for laser welding.  
     
     
         7 . The method according to  claim 4 , wherein the black colorant is nigrosine, aniline black, and/or carbon black.  
     
     
         8 . The method according to  claim 5 , wherein the black colorant is nigrosine, aniline black, and/or carbon black.  
     
     
         9 . The method according to  claim 6 , wherein the black colorant is nigrosine, aniline black, and/or carbon black.  
     
     
         10 . The method of  claim 1 , wherein the first polyolefin, second polyolefin, and/or thermoplastic resin contains one or more inorganic fillers and/or reinforcing agents.  
     
     
         11 . The method of  claim 10  wherein the fillers and/or reinforcing agents are one or more of glass fibers, carbon fibers, glass beads, talc, kaolin, wollastonite, and mica.  
     
     
         12 . A product made according to the process of  claim 1.