The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1988
Filed:
Jan. 30, 1987
Kyoichi Nakamura, Ibaraki, JP;
Kanegafuchi Kagaku Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
In a process for preparing pre-expanded particles of a thermoplastic resin which comprises releasing into a low pressure zone an aqueous dispersion of thermoplastic resin particles containing a volatile blowing agent, the dispersion being maintained at an elevated temperature under pressure in a pressure vessel, the improvement which comprises releasing the dispersion through an orifice having a ratio of the length to the average diameter of 4 to 100. According to the present invention, the pre-expanded particles having cells which are uniform in diameter and have an average dimeter of not less than 200 .mu.m can be obtained, and therefore the articles molded in a mold from the pre-expanded particles are small in the shrinkage and strain, are excellent in the appearance, and are increased in the productivity. Accordingly, the molded articles are utilizable for use of shock absorbing, wrapping materials or structural material such as impact-absorbing materials for cars which requires excellent dimensional precision and heat insulating building materials.