| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyolefin sheet having a broad width of thermoforming temperatures by melt-kneading a polypropylene resin, polyethylene resins having melting points different from each other by suitable degrees and an olefin resin having a glass transition temperatures different from the melting point of the polypropylene resin by suitable degrees and rapidly cooling the melt to form a sheet. SOLUTION: Forty (40) to 95wt.% polypropylene resin, 5-40wt.% at least two polyethylene resins having melting points (as measured according to JIS K 7121) different from each other by at least 8 deg.C and 5-40wt.% amorphous polyolefin resin having a glass transition temperature (measured by the above method) lower than the melting point of the polypropylene resin by 8 deg.C or above are melt-kneaded, and the obtained melt is rapidly cooled at 80 deg.C or below to form a thermoforamable polyolefin sheet. More desirably, this sheet is heat-treated at 90-160 deg.C. This sheet has a broad range of thermoforming temperatures and good formability, while it retains the features of a sheet made of a polypropylene resin. |
