US 12,221,526 B2
Method for preparing spherical or angular powder filler, spherical or angular powder filler obtained therefrom, and use thereof
Shuzhen Chen, Huzhou (CN); and Rui Li, Huzhou (CN)
Assigned to Zhejiang Third Age Material Technology Co., Ltd., Huzhou (CN)
Appl. No. 17/263,047
Filed by Zhejiang Third Age Material Technology Co., Ltd., Huzhou (CN)
PCT Filed Feb. 22, 2019, PCT No. PCT/CN2019/075832
§ 371(c)(1), (2) Date Jan. 25, 2021,
PCT Pub. No. WO2020/019709, PCT Pub. Date Jan. 30, 2020.
Application 17/263,047 is a continuation of application No. PCT/CN2018/097327, filed on Jul. 27, 2018.
Prior Publication US 2021/0309832 A1, Oct. 7, 2021
Int. Cl. C08K 5/5419 (2006.01); C08K 3/36 (2006.01)
CPC C08K 5/5419 (2013.01) [C08K 3/36 (2013.01)] 10 Claims
 
1. A method for preparing a spherical or angular powder filler, comprising the steps of:
S1, providing a spherical or angular siloxane comprising T units, wherein the T unit=R1SiO3—, and R1 is a hydrogen atom or an organic group independently selected from C1-C18;
S2, performing a heat treatment on the spherical or angular siloxane, the heat treatment temperature between 250° C. and the temperature of oxidative decomposition of organic groups, the heat treatment time is 30 min-24 h, so that silicon hydroxyl groups in the spherical or angular siloxane are condensed to obtain a condensed siloxane, wherein new isolated outer surface Si—OHs and internal cracked surface Si—OHs are produced due to the spatial geometric limitation of the condensed siloxane; and
S3, adding a treatment agent to treat the condensed siloxane to promote the condensation of silicon hydroxyl groups in the condensed siloxane to give a spherical or angular powder filler, the treatment agent comprising a silane coupling agent and/or disilazane, the weight percentage of the treatment agent being 0.5-50 wt %, and the quotient of the molecular weight of at least a portion of the silane coupling agent and/or the disilazane divided by its specific gravity at 25° C. being less than or equal to 210, wherein the silane coupling agent and/or disilazane enters the internal cracks of the powder due to its small molecule in order to promote the condensation of the internal cracked surface Si—OHs.