| 摘要 |
PURPOSE:To enable reduction of wall thickness, enhancement of transparency, and improvement of fit tightness by using a specified propylene type resin. CONSTITUTION:The main body 1 of a film cartridge is made of a polymer having >=70wt% propylene monomer units, a melt index of 16-80g/10min, a tensile yielding point stress of 250kg/cm<2>, a bending elasticity of >=10,000kg/cm<2>, a notched Izod impact strength of >=2.0kg.cm/cm<2>, and an average circumference wall thickness of 0.4-1.2mm.. The polymer contains a nucleating agent, serving as ensuring said various physical properties. A wall thickness near a resin injection part 4 is made thicker than the average thicknesses of the walls 2, 7 to prevent pinholes. Since such a material has high strength, the main body 1 can be reduced in thickness and improved in the fit tightness of a cap 3. It is good in transparency and needs no pigment. Since the resin is good in fluidity, high speed molding is made possible, and a rate of deffective molded products can be reduced. The main body 1 can be used also for the outer case to lower its cost, and printing is made on the outer surface of the body 1 to enhance saleability. |
