Repellent fluorochemical compositions

• US 20030136938A1
• Filed: 12/04/2001
• Published: 07/24/2003
• Est. Priority Date: 12/04/2001
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Jariwala, Chetan P., Clark, John C., Burleigh, Malcolm B., Zai-Ming, Qiu
• Granted Patent: US 7,056,846 B2
• Time in Patent Office: Days
• US Class Current: 252/8.62
• CPC Class Codes: C08G 18/2885 containing halogen atoms
• CPC Class Codes: Y10T 442/2279 Coating or impregnation improves soil repellency, soil release, or anti- soil redeposition qualities of fabric
• CPC Class Codes: Y10T 442/2287 Fluorocarbon containing

Abstract

This invention provides compositions for treating fibrous substrates to render those substrates durably repellent to water and oil and durably resistant to dry soil comprising a fluorochemical urethane formed by reacting a tri- or higher order isocyanate with a fluorochemical monofunctional compound; and optionally a non-fluorinated aliphatic monofunctional compound.

The present invention also provides a method of treating fibrous substrates to render those substrates durably repellent to water and oil and durably resistant to dry soil comprising application of the aforementioned composition to a fibrous substrate with optionally one or more hydrophilic anti-staining compounds such as acrylic and methacrylic acid polymers and copolymers, sulfonated phenol-formaldehyde resins, and styrene-maleic anhydride polymers and copolymers, said application of the composition taking place either coincident with or following application of the hydrophilic anti-staining compound or compounds to the substrate. Fibrous substrates treated according to this method and fibrous substrates treated with the aforementioned compositions are also disclosed.

Claims

1. A urethane composition comprising the reaction product of:

a. An aliphatic polyisocyanate having three or more isocyanate groups; and

b. A fluorochemical of the formula R_f—

SO₂N(R¹)—

R²-Z;

wherein R_f a perfluoroalkyl or perfluoroheteroalkyl group having from 3 to about 6 carbon atoms,

R¹ is a lower alkyl group,

R² is an alkylene or heteroalkylene group, and

Z is an isocyanate-reactive functional group, and said fluorochemical is in an amount sufficient to react with at least about 50% of the available isocyanate groups

2. The composition of claim 1 comprising the further reaction product of an aliphatic monofunctional compound.

3. The composition of claim 2 wherein said aliphatic monofunctional compound is of the formula R′

″

-Z, wherein R′

″

is an aliphatic group and Z is an isocyanate-reactive functional group.

4. The composition of claim 3 comprising compounds of the formula

(R_f*)_nA(NHCO-Z′

R′

″

)<sub>m−

n</sub>,

wherein

R_f* is R_f—

SO₂N(R¹)—

R²-Z′

,

Z′

is the residue of Z,

A is the residue of said aliphatic isocyanate, having valency m,

R′

″

is an aliphatic radical, and

n (average) is at least 1.5.

5. The composition of claim 1 wherein

R_f a fluorinated carbon chain having from 3 to about 6 carbon atoms,

R¹ is a —

H or —

CH₃,

R² is an alkylene group having 1 to 3 carbon atoms, and Z is —

OH.

6. The composition of claim 3 wherein the amount of aliphatic monofunctional compound is in an amount sufficient to react with the remaining available isocyanate groups.

7. The composition of claim 3 wherein the amount of aliphatic monofunctional compound is in an amount sufficient to react with 15% or less of the available isocyanate groups.

8. The composition of claim 1 wherein the amount of fluorochemical is in an amount sufficient to react with 75% or more of the available isocyanate groups.

9. The composition of claim 1 wherein R_f is a perfluorinated alkyl group.

10. The composition of claim 1 further comprising a hydrophilic anti-staining compound.

11. The fibrous substrate treatment composition comprising the urethane composition of claim 1 and a solvent.

12. The treatment composition of claim 11 comprising from about 0.05 to 10 weight percent of the urethane composition.

13. A method for imparting stain-release characteristics to a fibrous substrate comprising the steps of:

(a) applying a treatment composition of claim 12, and.

(b) allowing the treatment composition to cure.

16. An article comprising:

a fibrous substrate having a cured coating derived from at least one solvent and a chemical composition of claim 1.

17. The composition of claim 1 further comprising a surfactant.

14. The method of claim 14 wherein said treatment composition is applied in an amount sufficient to provide between 0.05% and 3% solids on fiber.

15. The method of claim 14 wherein said composition is cured at ambient temperature.