| 摘要 |
Provided is a method for manufacturing a foam-molded article by molding between molds (5) a parison (1) with a foam layer (3) formed by extruding an expandable molten resin composition, obtained by melt-kneading a polyethylene resin and a physical foaming agent, to an area of low pressure from a die (2), wherein the polyethylene resin is selected from at least any of the following I), II), and III), and wherein the apparent density of the foam layer in the foam-molded article is about 0.04 to 0.3 g/cm<3>, whereby a foam-molded article with a low apparent density and excellent physical properties can easily be obtained. I) A resin comprising 40 to 85 wt% polyethylene (A) with a density that is more than 0.94 g/cm<3> and not more than 0.97 g/cm<3>, and a melt flow rate of 0.1 to 20 g/10 minutes; and 15 to 60 wt% polyethylene (B) with a density of 0.89 to 0.94 g/cm<3>, a melt flow rate of 0.2 to 20 g/10 minutes, and a melt tension of not less than 2 cN (provided that the total of polyethylene (A) and (B) is 100 wt%). II) A resin which has at least one endothermic peak having a top temperature of not less than 125 DEG C on a DSC curve obtained by differential scanning calorimetry, and in which the ratio of the heat quantity of the endothermic peak(s) at not less than 125 DEG C with respect to the total heat quantity of the endothermic peak(s) is 50 to 95%, melt flow rate is 0.2 to 25 g/10 minutes, and melt tension is not less than 1.5 cN. III) A resin which comprises 40 to 85 wt% polyethylene (A) having a density more than 0.94 g/cm<3> and not more than 0.97 g/cm<3>, and a melt flow rate of 0.1 to 20 g/10 minutes; and 15 to 60 wt% polyethylene (B) having a density of 0.89 to 0.94 g/cm<3>, a melt flow rate of 0.2 to 20 g/10 minutes, and a melt tension of not less than 2 cN (provided that the total of polyethylene (A) and (B) is 100 wt%); which has at least one endothermic peak having a top temperature of not less than 125 DEG C on a DSC curve obtained by differential scanning calorimetry; and in which the ratio of the heat quantity of the endothermic peak(s) at not less than 125 DEG C with respect to the total heat quantity of the endothermic peak(s) is 50 to 95%, melt flow rate is 0.2 to 25 g/10 minutes, and melt tension is not less than 1.5 cN. <??>The foam-molded article of the present invention, as obtained by the above-described method, has a foam layer with an apparent density of about 0.04 to 0.3 g/cm<3> and a thickness of 2 to 25 mm, exhibits excellent heat resistance, mechanical strength, low-temperature impact resistance, and possesses excellent lightweight, thermal-insulating characteristics, soundproofing characteristics, vibration-proofing characteristics, chemical resistance, and recycling properties. <IMAGE> |
