초록 ▼

In the present invention, for the production of a blow-molded foam, there is used a base resin which is mainly composed of a polypropylene resin and has, at 230.degree. C., a melt tension (MT) of 10 gf or over and a melt flow rate (MFR) of 0.5 g/10 minutes or over. A foaming agent is added to the ba

In the present invention, for the production of a blow-molded foam, there is used a base resin which is mainly composed of a polypropylene resin and has, at 230.degree. C., a melt tension (MT) of 10 gf or over and a melt flow rate (MFR) of 0.5 g/10 minutes or over. A foaming agent is added to the base resin, followed by melt kneading by means of an extruder under high temperature and high pressure conditions to provide a foamable melt. This melt is subjected to extrusion from a circular die 5 and expanded to form a cylindrical foamed parison 4. Thereafter, molds 6, 6 are clamped, and the parison 4 in a softened condition is placed in the molds 6, 6, and a pressurized gas is blown into the parison 4 from a gas blowing port 7 for blow molding in the form of a hollow shape conforming to the mold profile to produce a blow-molded foam.

대표청구항 ▼

1. A blow-molded foam of the type which consists of a hollow molded foam obtained by blow-molding a parison in a desired form, characterized in that it comprises a foamed layer made of a base resin which is mainly composed of a polypropylene resin, wherein the resin forming said foamed layer has, at

1. A blow-molded foam of the type which consists of a hollow molded foam obtained by blow-molding a parison in a desired form, characterized in that it comprises a foamed layer made of a base resin which is mainly composed of a polypropylene resin, wherein the resin forming said foamed layer has, at 230.degree. C., a melt tension (MT) of 5 gf or over and a melt flow rate (MFR) of 1 g/10 minutes or over, and the foamed layer has an average cell diameter from about 0.05 to about 2.2 mm, an average thickness of about 0.5 mm or over, and an average density of about 0.30 g/cm3 or below.