Colored thermoplastic resin compositions for laser welding, specific neutral anthraquinone dyes as colorants therefor, and molded product therefrom

Abstract

Thermoplastic resin compositions suitable for laser welding are disclosed, which include a mixture of neutral anthraquinone dyes and at least one other red dye to absorb and transmit select regions of visible light and to enhance weldability.

1 . A thermoplastic resin composition for laser welding comprising: 
 1) thermoplastic resin; and,    2) a laser transmitting black colorant comprising a mixture of a) neutral anthraquinone dye which imparts colors of blue, violet or green, absorbs visible light with wavelength less than 700 nm and transmits a laser beam with wavelength at 800 nm to 1200 nm in the infra-red region with b) at least one other red dye which transmits with a wavelength at 800 nm to 1200 nm in infra-red region.    
     
     
         2 . The composition of  claim 1  wherein said colorant comprises a mixture of said neutral anthraquinone blue dyes with said red dyes and further other yellow dyes.  
     
     
         3 . The composition of  claim 1  wherein said thermoplastic resin is polyamide or polyester.  
     
     
         4 . The composition of any of claims  1 - 3  wherein said red dye is selected from the group consisting of perinone dyes, monoazo complex dyes and anthraquinone dyes.  
     
     
         5 . The composition of  claim 1  further comprising reinforcing agent.  
     
     
         6 . A laser-transmitting article formed from the composition of  claim 1 .  
     
     
         7 . An article formed by laser welding a laser-absorbing article with the laser-transmitting article of  claim 6 .  
     
     
         8 . A laser-transmitting black colorant suitable for being mixed with a thermoplastic resin applied to a laser welding comprising a mixture of a) neutral anthraquinone dye which imparts colors of blue, violet or green, absorbs visible light with wavelength less than 700 nm and transmits a laser beam with wavelength at 800 nm to 1200 nm in infra-red region with b) at least other red dye which transmits the laser beam with wavelength at 800 nm to 1200 nm in infra-red region.  
     
     
         9 . The colorant of  claim 8  comprising said mixture of neutral anthraquinone blue dyes with red dyes and further yellow dyes.