Polyurethanes containing perfluoroalkyl groups and a process for their production

• US 4,540,765 A
• Filed: 05/18/1984
• Issued: 09/10/1985
• Est. Priority Date: 05/27/1983
• Status: Expired due to Term

• Current Assignee: Bayer AG
• Original Assignee: Bayer AG
• Inventors: Geisler, Klaus, Koemm, Ulrich
• Primary Examiner(s): WELSH JR, MAURICE
• Application Number:
  US06/612,095
• Time in Patent Office: 480 Days
• Field of Search: 528/45, 427/389.9, 427/176
• US Class Current: 528/45
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/2805 Compounds having only one group containing active hydrogen vinylpolymers having terminal groups containing active hydrogen C08G18/62
• CPC Class Codes: C08G 18/3812 having fluorine atoms
• CPC Class Codes: C08G 18/3825 containing amide groups C08G18/3821 takes precedence
• CPC Class Codes: C08G 18/3861 containing sulfonamide and/or sulfonylhydrazide groups
• CPC Class Codes: C08G 18/8077 Oximes
• CPC Class Codes: D06M 15/576 containing fluorine

Abstract

To render surfaces, such as of textile fabrics and fibers, repellent to oil and/or water, they are treated with novel polyurethanes containing perfluoroalkyl ligands and having as recurring structural units ##STR1## with chain ends of the formula

--YA.sub.m'"'"'

in which

X, Y and Z each independently is the skeletal radical of an aliphatic or aromatic di- or polyisocyanate,

R_F is a difunctional radical containing at least one perfluoroalkyl ligand, the perfluoroalkyl chain comprising 3 to 30 carbon atoms and, in addition to fluorine atoms, containing at most one hydrogen or chlorine atom to two carbon atoms; and the perfluoroalkyl chain optionally being interrupted by oxygen,

n is the number of isocyanate groups on the skeletal radical X and is an integer from 2 to 25,

A is an isocyanate group protected by a blocking agent,

m is the number of blocked isocyanate groups A on the skeletal radical Y and is an integer from 1 to 5,

E is O, S or --NR'"'"'--,

R'"'"' is H, alkyl or aryl,

R is the radical of a compound containing at least two alcohol, amine and/or thiol groups,

a and b are the number of --OH, --NR'"'"'H or --SH functions in the alcohols, amines or thiols R(EH).sub.(a+b) used and each is an integer from 0 to 10, and

p is the number of isocyanate groups on the skeletal radical Z and is an integer from 0 to 25.

Subsequent heating removes the end blocks and effects chemical fixation on the surface.

Claims

1. A polyurethane containing perfluoroalkyl ligands and having as recurring structural units ##STR7## with chain ends of the formula

View Dependent Claims (2, 3, 4, 5, 6)

2. A polyurethane containing perfluoroalkyl ligands according to claim 1, wherein the blocking agent of A is the radical of an oxime.

3. A process for producing a polyurethane containing perfluoroalkyl ligands according to claim 1, comprising condensing an excess of a dialcohol containing perfluoroalkyl ligands and of the following formula

4. In the treatment of a surface with a perfluoralkyl-containing polyurethane to render it oil- and/or water-repellent, the improvement which comprises employing as the perfluoroalkyl-containing polyurethane a material according to claim 1 and thereafter heating to effect chemical fixation with the surface.

5. The process according to claim 4, wherein the surface is a textile fiber or fabric.

6. The process according to claim 4, wherein the surface is that of a synthetic fiber as spun, the fiber thereafter being drawn and heated to effect the chemical fixation.