	US 11,807,958 B2
	Oleophobic polyamide fine fibers, methods, filter media, and filter elements
Suresh L. Shenoy, Bloomington, MN (US); Thomas M. Weik, Deephaven, MN (US); and Matthew P. Goertz, Bloomington, MN (US)
Assigned to DONALDSON COMPANY, INC., Minneapolis, MN (US)
Appl. No. 16/772,296
Filed by DONALDSON COMPANY, INC., Minneapolis, MN (US)
PCT Filed Dec. 12, 2018, PCT No. PCT/US2018/065271 § 371(c)(1), (2) Date Jun. 12, 2020, PCT Pub. No. WO2019/118636, PCT Pub. Date Jun. 20, 2019.
Claims priority of provisional application 62/598,303, filed on Dec. 13, 2017.
Prior Publication US 2021/0079560 A1, Mar. 18, 2021
Int. Cl. D01F 1/10 (2006.01); D01D 5/00 (2006.01); D01F 6/60 (2006.01); D01F 6/90 (2006.01); B01D 39/16 (2006.01)

CPC D01F 1/10 (2013.01) [B01D 39/1623 (2013.01); D01D 5/003 (2013.01); D01F 6/60 (2013.01); D01F 6/90 (2013.01); B01D 2239/0428 (2013.01); B01D 2239/0618 (2013.01); B01D 2239/0631 (2013.01); B01D 2239/0654 (2013.01); D10B 2401/021 (2013.01); D10B 2505/04 (2013.01)]

13 Claims

1. A fine fiber comprising:

a fiber-forming polyamide; and

a fluorochemical urethane additive incorporated within the fine fiber;

wherein the fluorochemical urethane additive includes one or more perfluorinated alkyl groups and/or perfluorinated heteroalkyl groups, and each alkyl or heteroalkyl group is bonded to a sulfonamido (—SO₂NR²—) group, a carboxamido (—C(O)NR³—) group, a carboxyl group (—C(O)O—), or a sulfonyl group (—SO₂—), wherein R²and R³are independently a hydrogen or an alkyl, and

wherein the fine fiber is an electrospun fiber having an average diameter less than 10 μm and comprises a core phase and a coating phase, wherein the fiber-forming polyamide is present in the core phase at a concentration of 50% by weight or more and the fluorochemical urethane additive is present in the coating phase at a concentration of 50% by weight or more.