0818292-A2 is referenced by 30 patents and cites 5 patents.

A process for preparing an expanded product of a thermoplastic resin is herein disclosed which comprises a gas dissolving step of adding supercritical carbon dioxide and/or nitrogen as an blowing agent to a thermoplastic resin, and melting it in the thermoplastic resin, a cooling step of cooling the resulting molten resin composition under a pressure not less than a critical pressure of the blowing agent, a nuclei forming step of discharging the molten resin composition from a die(4)to lower the pressure to a level not more than the critical pressure, and an expansion controlling step of cooling an expanded product of the thermoplastic resin to a level not more than a glass transition temperature or a crystallization temperature of the resin to control a cell diameter of the expanded product, wherein the process comprises a shear rate adjusting section (12); having a function of generating a shear rate in the range of 10 to 10 sec and having a sectional area A, and a flow velocity distribution adjusting section (13) having a function of lowering the shear rate and having a sectional area B, and B/A is in the range of 1.3 to 20, whereby a cell diameter and a cell density are controlled. According to this process, the expanded product of the thermoplastic resin can be obtained which has an excellent surface appearance, a high strength, and cells of a fine average cell diameter and a uniform average cell density and in which carbon dioxide and/or nitrogen is used as the blowing agent.

Title
Process for preparing expanded product of thermoplastic resin
Application Number
EP19970305063 19970709
Publication Number
0818292 (A2)
Application Date
July 9, 1997
Publication Date
January 14, 1998
Inventor
Amemiya Hideo
JP
Sueda Takanori
JP
Eriguchi Michio
JP
Inoue Haruo
JP
Ichikawa Kouzo
JP
Yorita Kaoru
JP
Nishikawa Shigeo
JP
Assignee
Mitsui Toatsu Chemicals
JP
IPC
B29C 44/46
B29C 44/34
B29C 44/46
B29C 44/34
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