Polybutylene terephthalate resin composition for fusion bonding with laser and molded article

Abstract

A laser weldable PBT-series resin composition comprises a polybutylene terephthalate (PBT)-series resin (A), and at least one resin (B) selected from the group consisting of a polycarbonate-series resin (b1), a styrenic resin (b2), a polyethylene terephthalate-series resin (b3) and an acrylic resin (b4). The PBT-series resin (A) may be a PBT homopolyester, or a PBT-series copolymer modified with not more than 30 mol % of a copolymerizable monomer (e.g., a bisphenol compound or an adduct thereof with an alkylene oxide, and an asymmetrical aromatic dicarboxylic acid). The ratio (weight ratio) of the resin (B) relative to the PBT-series resin (A) [the former/the latter] is about 0.1/1 to 1.5/1. The resin composition may comprise a glass fiber. The resin composition is excellent in laser weldability, and can improve in welding strength of a shaped article formed from the resin composition.

1 . A laser weldable polybutylene terephthalate-series resin composition which comprises a polybutylene terephthalate-series resin (A) and at least one resin (B) selected from the group consisting of a polycarbonate-series resin (b1), a styrenic resin (b2), a polyethylene terephthalate-series resin (b3) and an acrylic resin (b4).  
     
     
         2 . A resin composition according to  claim 1 , wherein the polybutylene terephthalate-series resin (A) comprises a polybutylene terephthalate or a polybutylene terephthalate-series copolymer modified with a copolymerizable monomer.  
     
     
         3 . A resin composition according to  claim 2 , wherein the copolymerizable monomer comprises at least one member selected from the group consisting of a bisphenol compound or an adduct thereof with an alkylene oxide, and an asymmetrical aromatic dicarboxylic acid or a derivative thereof capable of forming an ester.  
     
     
         4 . A resin composition according to  claim 2 , wherein the copolymerizable monomer comprises at least one member selected from the group constituting of phthalic acid, isophthalic acid, and an adduct of bisphenol A with an alkylene oxide, and a reactive derivative thereof.  
     
     
         5 . A resin composition according to  claim 1 , wherein the ratio of the resin (B) relative to the polybutylene terephthalate-series resin (A) [the former (B)/the latter (A)] is 0.1/1 to 1.5/1 (weight ratio).  
     
     
         6 . A resin composition according to  claim 1 , which has a light transmittance of not less than 15% for a wavelength of 800 to 1100 nm at a thickness of 3 mm in a shaped article formed from the resin composition by an injection molding.  
     
     
         7 . A resin composition according to  claim 1 , which further comprises a reinforcer capable of transmitting a laser beam.  
     
     
         8 . A resin composition according to  claim 1 , which further comprises a glass fiber.  
     
     
         9 . A laser weldable polybutylene terephthalate-series resin composition which comprises 
 at least one polybutylene terephthalate-series resin (A) selected from the group consisting of a polybutylene terephthalate and a polybutylene terephthalate-series copolymer modified with 0.01 to 30 mol % of a copolymerizable monomer, and    at least one resin (B) selected from the group consisting of a polycarbonate-series resin (b1), a styrenic resin (b2), a polyethylene terephthalate-series resin (b3) and an acrylic resin (b4),    wherein the ratio of the resin (B) relative to the polybutylene terephthalate-series resin (A) [the former (B)/the latter (A)] is 0.1/1 to 1.5/1 (weight ratio), and    the copolymerizable monomer comprises at least one member selected from the group consisting of phthalic acid, isophthalic acid, an adduct of bisphenol A with an alkylene oxide, and a reactive derivative thereof.    
     
     
         10 . A shaped article formed from a resin composition recited in  claim 1 .  
     
     
         11 . A shaped composite article comprising a shaped article formed from a resin composition recited in  claim 1 , and a counterpart shaped article formed from a resin, wherein the shaped article is bonded to the counterpart shaped article through a welding by a laser.