US 10,889,694 B2
Method and composition for preparing polyamide powders
Chia-Hung Yang, Taichung (TW); Yu-Pao Huang, Taichung (TW); Hsing-Fu Yeh, Taichung (TW); Yao-Tang Ke, Taichung (TW); Feng-Lin Chen, Taichung (TW); Yung-Chih Chen, Taichung (TW); and Yi-Chung Su, Taichung (TW)
Assigned to Taiwan Green Point Enterprises Co., Ltd., Taichung (TW)
Filed by Taiwan Green Point Enterprises Co., Ltd., Taichung (TW)
Filed on Jul. 1, 2019, as Appl. No. 16/458,770.
Claims priority of application No. 2018 1 0737968 (CN), filed on Jul. 6, 2018.
Prior Publication US 2020/0010626 A1, Jan. 9, 2020
Int. Cl. C08J 3/14 (2006.01); C08J 3/11 (2006.01); C08J 3/09 (2006.01); C08K 3/36 (2006.01); C08K 3/22 (2006.01); C08J 3/215 (2006.01)
CPC C08J 3/14 (2013.01) [C08J 3/096 (2013.01); C08J 3/11 (2013.01); C08J 3/215 (2013.01); C08K 3/22 (2013.01); C08K 3/36 (2013.01); C08K 2003/2241 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method of preparing polyamide powders, comprising the steps of:
(a) heating a composition including polyamide granules, a nucleating agent and an organic solvent under normal pressure to a first temperature (T1) equal to or higher than the melting point (Tm) of the polyamide granules, followed by maintaining at the first temperature for a first time period to dissolve the polyamide granules in the organic solvent;
(b) cooling the heated composition to a second temperature (T2) to nucleate the dissolved polyamide granules, followed by maintaining at the second temperature (T2) to crystallize, so as to form a crystallization product, in which 15° C.≤Tm−T2≤33° C.;
(c) cooling the crystallization product to precipitate polyamide, so as to form a precipitated product; and
(d) washing the precipitated product to remove the organic solvent,
wherein the weight ratio of the polyamide granules to the organic solvent ranges from 0.11 to saturation solubility of the polyamide granules in the organic solvent, and the weight ratio of the polyamide granules to the nucleating agent is 100:1.