Abstract: The present invention relates to a metal-polymer resin composite in which a polymer resin is directly injection-molded to a zinc alloy, a magnesium alloy, or a die-casting part thereof, and thus an injection product is directly bonded to a metal surface, wherein in the case of a hard polymer resin, a tensile strength of the metal and the polymer resin is 30 MPa or greater, and in the case of a soft polymer resin, a tensile strength of the metal and the polymer resin is 20 MPa or greater, and an average helium leakage after 10 times of measurement is 10?8 Pa·m3/s or less, and a novel method for preparing the same.

Abstract: The present disclosure provides a method for preparing a titanium-resin assembly for improving the adhesion strength between a substrate containing titanium and a resin, which includes: a first pore formation step of immersing a substrate comprising titanium in a first solution and forming pores in the substrate by etching the same; a second pore formation step of immersing the substrate having pores formed in the first pore formation step in a second solution and forming another pores by etching the same; an electrolysis step of immersing the substrate that has undergone the second pore formation step in an electrolytic solution and conducting electrolysis; and a molding step of joining the substrate with a polymer resin and conducting injection molding, wherein the first solution is an alkaline solution with a pH>7 and the second solution is an acidic solution with a pH<7.