Patent ID: 8318051

Claim:
A light-absorbent resin composition for laser welding, comprising laser light absorbent nanoparticles and a polymer dispersing agent that has a glass transition temperature of 30° C. or higher, wherein the laser-light-absorbent nanoparticles are at least one of nanoparticles of tungsten oxide indicated by the general formula W y O z , wherein W is tungsten, O is oxygen, and 2.0<z/y<3.0, and nanoparticles of composite tungsten oxide indicated by the general formula M x W y O z , wherein M is one or more elements selected from the group consisting of hydrogen, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Ti, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I; W is tungsten; O is oxygen; 0.001<x/y<1; and 2.0<z/y<3.0, and the light-absorbent resin composition for laser welding is a solid powder at room temperature, wherein the polymer dispersing agent is included in a ratio of 2 to 10 times the weight of the laser light absorbent nanoparticles, and a content ratio of the nanoparticles of tungsten oxide or the composite tungsten oxide in a region that is 3 mm or less from a surface and that constitutes a surface layer of the light-absorbent resin molding is 0.01 g/m 2 or higher and 32 g/m 2 or less.