Laser-welded article

Abstract

A laser-welded article comprises: an integral construction of piled workpieces, that are welded by exothermic through irradiating laser and include thermoplastic resin, comprises of a laser-transmissible-absorptive molded workpiece including a thermoplastic resin and 0.001 to 0.3 weight % of colorant consisting of nigrosine which has an absorption coefficient: ε for a ray of 940 nm ranging form 4000 to 7000, that transmits laser partially and absorbs laser partially, and a laser-absorptive molded workpiece including a thermoplastic resin and 0.1 to 5 weight % of diverse colorant comprising of nigrosine and/or carbon black, that absorbs the laser.

1 . A laser-welded article comprising: 
 an integral construction of piled workpieces, that are welded by exothermic through irradiating laser, comprises of    a laser-transmissible-absorptive molded workpiece including a thermoplastic resin and 0.001 to 0.3 weight % of colorant consisting of nigrosine which has an absorption coefficient: ε for a ray of 940 nm ranging form 4000 to 7000 (ml/g·cm), that transmits laser partially and absorbs laser partially,    and a laser-absorptive molded workpiece including a thermoplastic resin and 0.1 to 5 weight % of diverse colorant comprising of nigrosine and/or carbon black, that absorbs the laser.    
     
     
         2 . The laser-welded article according to  claim 1 , wherein the diverse colorant includes carbon black.  
     
     
         3 . The laser-welded article according to  claim 2 , wherein the diverse colorant furthermore includes nigrosine.  
     
     
         4 . The laser-welded article according to  claim 1 , wherein the laser-transmissible-absorptive molded workpiece satisfies the following numerical expression (I) 
         0.07≦a 1 =ε 1 C 1 L 1 ≦0.8  (I) 
       (in the numerical expression (I), a 1  is absorbance thereof, ε 1  (1/cm) is an absorption coefficient thereof, C 1  (weight %) is concentration of the colorant therein, L 1  (cm) is thickness thereof).  
     
     
         5 . The laser-welded article according to  claim 1 , wherein the laser-absorptive molded workpiece satisfies the following numerical expression(II) 
         1≦a 2 =ε 2 C 2 L 2 ≦50  (II) 
       (in the numerical expression(II), a 2  is absorbance thereof, ε 2  (1/cm) is an absorption coefficient thereof, C 2  (weight %) is concentration of the diverse colorant therein, L 2  (cm) is thickness thereof).  
     
     
         6 . The laser-welded article according to  claim 1 , wherein nigrosine includes at least one selected from a group consisting of compounds represented by following chemical formulas (1) to (4).  
       
         
           
           
               
               
           
         
       
     
     
         7 . The laser-welded article according to  claim 1 , wherein the laser-transmissible-absorptive molded workpiece includes at least one thermoplastic resin selected from a group consisting of polyamide resin, polycarbonate resin, polyphenylene sulfide resin, polyester resin, and polyolefin-type resin.  
     
     
         8 . The laser-welded article according to  claim 7 , wherein the laser-transmissible-absorptive molded workpiece includes the thermoplastic resin of polyamide resin and 0.01 to 0.2 weight % of the colorant consisting of nigrosine.  
     
     
         9 . The laser-welded article according to  claim 7 , wherein the laser-transmissible-absorptive molded workpiece includes the thermoplastic resin of polycarbonate resin and 0.01 to 0.2 weight % of the colorant consisting of nigrosine.  
     
     
         10 . The laser-welded article according to  claim 1 , wherein concentration of iron in nigrosine is 1% at maximum.  
     
     
         11 . The laser-welded article according to  claim 1 , wherein concentration of aniline in nigrosine is 1% at maximum.  
     
     
         12 . The laser-welded article according to  claim 1 , wherein the laser-transmissible-absorptive molded workpiece and the laser-absorptive molded workpiece have thickness ranging from 200 to 5000 microns.  
     
     
         13 . The laser-welded article according to  claim 1 , wherein the laser-transmissible-absorptive molded workpiece and the laser-absorptive molded workpiece are films having thickness ranging from 200 to 1000 microns.