Polyurethanes

• US 20050164010A1
• Filed: 01/27/2005
• Published: 07/28/2005
• Est. Priority Date: 01/27/2004
• Status: Active Grant

• Current Assignee: Solvay Solexis SPA (Solvac SA)
• Original Assignee: Solvay Solexis SPA (Solvac SA)
• Inventors: Trombetta, Tania
• Granted Patent: US 7,655,310 B2
• Time in Patent Office: Days
• US Class Current: 428/423.400
• CPC Class Codes: C08G 18/0804 Manufacture of polymers containing ionic or ionogenic groups
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/3228 acyclic
• CPC Class Codes: C08G 18/3893 containing silicon
• CPC Class Codes: C08G 18/5015 having fluorine atoms
• CPC Class Codes: C08G 18/61 Polysiloxanes
• CPC Class Codes: C08G 18/6692 with compounds of group C08G18/34
• CPC Class Codes: C09D 175/08 from polyethers
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31558 Next to animal skin or membrane
• CPC Class Codes: Y10T 428/31605 Next to free metal

Abstract

Polyurethanes-urea based on perfluoropolyethers comprising ionizable groups and pendant groups having the following structure:
—R^I—Si(OR^II)_n(OH)_3−n   (I) wherein:

• • R^I is alkylene from 1 to 10 carbon atoms;
  • R^II is an alkyl group from 1 to 4 carbon atoms; n is an integer from 0 to 3.

Claims

1. Polyurethanes-urea based on perfluoropolyethers comprising:

ionizable groups;

pendant groups along the polymeric chain backbone having the following structure;

—

R^I—

Si(OR^II)_n(OH)<sub>3−

n</sub>  

 

(I)

wherein;

R^I is alkylene from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, still more preferably from 2 to 4 carbon atoms;

R^II is a linear or branched alkyl group from 1 to 4, preferably from 1 to 3 carbon atoms;

n is an integer from 0 to 3.

2. Polyurethanes according to claim 1, comprising units deriving from the following monomers:

a) (per)fluoropolyether diols having a number average moelcular weight from 400 to 5,000, preferably from 800 to 2,500;

b) diisocyanates selected from one or more of the following;

OCN—

R—

NCO  

 

(IA)

wherein R is a bivalent radical selected from the following;

C₂-C₁₂ aliphatic;

C₆-C₁₈ cycloaliphatic or alkylen-cycloaliphatic, wherein optionally the cycloaliphatic ring can be substituted with one or more C₁-C₃ alkyl groups, or

R contains two cyloaliphatic rings, each containing one of the NCO groups indicated in (IA), said rings joined together by a C₁-C₆ alkylene chain;

C₆-C₁₈ aromatic, wherein the aromatic ring can be substituted with one or more C₁-C₃ alkyl groups, or

R contains two aromatic rings, each containing one of the NCO groups indicated in (IA), said rings joined with each other by a C₁-C₆ alkylene chain;

c) diols having an ionizable function, selected from the following;

c.0) diols having a carboxylic function, of the following general formula (IB);

T is a linear or branched C₂-C₂₀, preferably C₂-C₁₀, trivalent aliphatic radical;

the two hdyroxyls linked to T can replace also two different aliphatic chains of the trivalent radical, and they never are on the same carbon atom;

c.1) diols comprising an amine function, having formula (I.a);

R_N is a linear or branched C₁-C₆, preferably C₁-C ₄ alkyl;

R_CI is H or C₁-C₄ alkyl, NI is an integer and ranges from 1 to 4, NIA is an integer and ranges from 0 to 4, NIB is an integer and ranges from 1 to 4;

c.2) diols with amine group in the chain, having formula (I.b);

wherein R_N and NI have the above meanings;

d) diamines containing in the molecule one silicon atom, having formula (I.d);

(R_D)NH—

R⁰—

NH—

R^I—

Si(OR^II)₃  

 

(I.d)

wherein;

R_D is hydrogen or C₁-C₃ alkyl;

R⁰, equal to or different from R^I, has the same meangins as R^I;

R^I and OR^II are as above;

e) optionally chain extenders, selected from C₁-C₆ aliphatic diols, for example diethylenglycol;

C₃-C₁₀ cycloaliphatic, such as cyclohexyldimethanol, C₆-C₁₂ aromatic, hydroquinone bis(2-hydroxyethylether);

C₂-C₆ aliphatic diamines, hydrazine.

3. Polyurethanes according to claim 2, wherein the percentages by weight of the monomers in the polyurethane, are the following:

a);

50%-85%, preferably 55%-75%;

b);

10%-40%, preferably 10%-30%;

c);

3%-10%, preferably 3%-7%;

d);

1%-12%, preferably 4%-10%;

e);

0-12%, preferably 1%-7%;

being 100% the sum of the components.

4. Polyurethanes according to claims 1-3, wherein the amount of groups of formula (I), expressed in equivalents of silicon/kg of polyurethane, ranges from 0.05 to 0.5 eq/Kg of polymer.

5. Polyurethanes according to claims 1-4, wherein the bifunctional (per)fluoropolyethers indicated in a) have one or more of the following units statistically distributed along the chain:

(C₃F₆O);

(CFYO) wherein Y is F or CF₃;

(CF₂CF₂O);

(CF₂(CF₂)_x′

CF₂O) wherein x′

is an integer equal to 1 or 2;

(CR₄R₅CF₂CF₂O) wherein;

R₄ and R₅ are equal to or different from each other and selected between H, Cl, and one fluorine atom of the perfluoromethylene unit can optionally be substituted with H, Cl or (per)fluoroalkyl having, for example, from 1 to 4 carbon atoms.

6. Polyurethanes according to claim 5, wherein the (C₃F₆O) unit is selected between (CF₂CF(CF₃)O) and (CF(CF₃)CF₂O).

7. Polyurethanes according to claim 5, wherein the bifunctional compounds a) have the following perfluorooxyalkylene structures:

(a′

) —

CF₂—

O—

(CF₂CF₂O)_p′

(CF₂O)_q′

—

CF₂—

wherein;

p′ and

q′

are numbers such that the q′

/p′

ratio is between 0.2 and 4, p′

being different from zero; and

the number average molecular weight is in the above range;

(b′

) —

CFY—

O—

(CF₂CF(CF₃)O)_r′

—

(CF₂CF₂O)_s′

—

(CFYO)_t′

—

CFY—

wherein;

Y is as above;

r′

, s′ and

t′

are numbers such that r′

+s′

is between 1 and 50, the ratio t′

/(r′

+s′

) is between 0.01 and 0.05, r′

+s′

being different from zero, and the number average molecular weight is in the above range;

(c′

) —

CF (CF₃)(OCF₂CF (CF₃))_u′

—

OR′

_fO—

(CF(CF₃)CF₂O)_u′

(CF(CF₃)—

wherein;

R′

_f is a C₁-C₃ perfluoroalkyl bifunctional radical;

u′

is a number such that the number average molecular weight is in the above range;

(c″

) —

CFYO—

(CFYO)_t′

—

((CF₃)CFCF₂O)_r′

—

R′

_fO—

(CF₂CF(CF₃)O)_r′

—

(CFYO)_t′

—

CFY—

wherein;

R′

_f is a C₁-C₃ perfluoroalkyl bifunctional radical;

r′

, t′ and

Y are as above;

r′ and

t′

such that the number average molecular weight is in the above range;

(d′

) —

CF₂CF₂O—

(CF₂(CF₂)_x′

CF₂O)_v′

—

CF₂CF—

wherein;

v′

is a number such that the molecular weight is in the above range, x′

is an integer equal to 1 or 2;

(e′

) —

CF₂CH₂—

(OCF₂CF₂CH₂)_w′

—

OR′

_fO—

(CH₂CF₂CF₂O)_w′

—

CH₂CF₂—

wherein;

R′

_f is as above;

w′

is a number such that the number average molecular weight is in the above range;

the end groups of the bifunctional perfluoropolyethers component a) being of the —

CH₂—

(OCH₂CH₂)_k′

—

OH type, wherein k′

is a number between 0 and 6, preferably between 0 and 2.

8. Polyurethanes according to claims 2-7, wherein the diamines component d) are selected from the group of the following compounds:

N-(2-aminoethyl)-3-aminopropyltrimethoxysilane NH₂—

(CH₂)₂—

NH—

(CH₂)₃—

Si(OCH₃)₃,

N-(2-aminoethyl)-2-aminoethyltrimethoxysilane, NH₂—

(CH₂)₂—

NH—

(CH₂)₂—

Si(OCH₃)₃,

N-(3-aminopropyl) -3-aminopropyltrimethoxysilane NH₂—

(CH₂)₃—

NH—

(CH₂)₃—

Si(OCH₃)₃.

9. Polyurethanes according to claim 8, wherein the diamine component d) is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

10. A process to obtain anionic polyurethanes according to claims 1-9, comprising the following steps:

obtainment of the prepolymer by reaction of the perfluoropolyether diol component a) with component c.0) salified with a tertiary amine and the diisocyanate component b) in excess, working at a temperature between 20°

C. and 40°

C., at a dry product concentration higher than 80% by weight by using a solvent not containing in its molecule reactive hydrogen groups, partially or totally soluble with water, the end of the reaction being determined by controlling the NCO titre according to ASTM D 2572;

the reaction mixture containing the prepolymer is dispersed in water at a temperature from 5°

to 15°

C. and it is added a mixture of component d), diamines containing in the molecule one silicon atom, with the optional component e);

the amount of components d) and e) being such that the meq. of the total aminic groups are in defect, preferably lower than 2% in percentage, with respect to the NCO meq. of the prepolymer;

the reaction is followed until the disappearance of the NCO group by IR at 2260 cm<sup>−

1</sup>.

11. A process for obtaining cationic polyurethanes according to claims 1-9, comprising the following steps:

obtainment of the NCO ended bifunctional fluorinated prepolymer by reacting the bifunctional perfluoropolyethers component a) with the diisocyanates component b) in molar excess, at a temperature from 50°

C. to 70°

C. with a dry product content between 50% and 70% by weight by using organic solvents not containing in their molecules reactive hydrogen groups, and partially or totally soluble with water;

the end of the reaction being determined by controlling the NCO titre according to ASTM D 2572;

maintaining the reaction mixture in the above temperature range, addition of a diol selected in the c.1) and/or c.2) groups, optionally in admixture with the aliphatic diols component e), in an amount such that the OH equivalents are in defect with respect to the NCO eq., finally determining again the NCO titre;

the reaction mixture is cooled to a temperature between 15°

C. and 25°

C. and component d) is added so that the total equivalents of aminic groups are equal to the NCO titre;

salification of the polymer obtained with organic acids, or by carrying out the quaternization of the tertiary aminic nitrogen atoms in the polyurethane with nitrogen alkylating agents;

to the organic solution of the salified polymer water is added under stirring, by distilling the organic solvent under vacuum.

12. Formulations containing the polyurethanes of claims 1-9.

13. Formulations according to claim 12 comprising additives selected from pigments, viscosity regulators, antifoam agents, UV stabilizers.

14. Use of the formulations according to claims 12-13 for application on substrata.

15. Use according to claim 14, wherein the substrata are selected among metals, plastic or natural or synthetic rubber sections, bricks, ceramic and stony materials, skins and leather.

16. Coatings obtainable by applying on substrata the formulations of claims 12-13.