	US 11,814,490 B2
	Method for producing low molecular weight polytetrafluoroethylene, low molecular weight polytetrafluoroethylene, and powder
Ken Yoshida, Osaka (JP); Hirotoshi Yoshida, Osaka (JP); Keisuke Hagi, Osaka (JP); Masayuki Tsuji, Osaka (JP); Taketo Kato, Osaka (JP); Yuuji Tanaka, Osaka (JP); Taku Yamanaka, Osaka (JP); Kazuya Kawahara, Osaka (JP); Masamichi Sukegawa, Osaka (JP); and Kazutaka Hosokawa, Osaka (JP)
Assigned to DAIKIN INDUSTRIES, LTD., Osaka (JP)
Filed by DAIKIN INDUSTRIES, LTD., Osaka (JP)
Filed on Oct. 23, 2020, as Appl. No. 17/078,365.
Application 17/078,365 is a continuation of application No. 16/069,735, granted, now 10,870,735, previously published as PCT/JP2017/028469, filed on Aug. 4, 2017.
Claims priority of application No. 2016-153856 (JP), filed on Aug. 4, 2016.
Prior Publication US 2021/0040274 A1, Feb. 11, 2021
Int. Cl. C08J 3/12 (2006.01); C08J 3/28 (2006.01); C08F 8/50 (2006.01); C08F 8/06 (2006.01); C08F 14/26 (2006.01)

CPC C08J 3/12 (2013.01) [C08F 8/06 (2013.01); C08F 8/50 (2013.01); C08F 14/26 (2013.01); C08J 3/28 (2013.01); C08F 2500/07 (2013.01); C08F 2500/17 (2013.01); C08F 2800/20 (2013.01); C08F 2810/40 (2013.01); C08J 2327/18 (2013.01); C08J 2327/22 (2013.01)]

1 Claim

1. Powder comprising low molecular weight polytetrafluoroethylene,

the low molecular weight polytetrafluoroethylene having a melt viscosity of 1×10²to 7×10⁵Pa·s at 380° C., having an average particle size of 1.0 to 20 μm, and containing 30 or more carboxyl groups at ends of the molecule chain per 10⁶carbon atoms in the main chain,

the powder being substantially free from C8-C14 perfluorocarboxylic acids and salts thereof,

wherein the powder has a specific surface area of not smaller than 0.5 m²/g but smaller than 7.0 m²/g, or not smaller than 9.0 m²/g and not larger than 20 m²/g,

wherein the perfluorocarboxylic acids and salts thereof amount to less than 25 ppb.