AQUEOUS DISPERSION OF A POLYURETHANE COMPRISING A DICARBOXYLATE WITH ONE OR TWO SECONDARY AMINO GROUP

Abstract

An aqueous dispersion of a polyurethane wherein the polyurethane is obtained by reacting di- or polyfunctional cyanates, diols, a dicarboxylate with one or two secondary amino groups and optionally further compounds.

Claims

1.-11. (canceled)

12. A synthesis of a dicarboxylate with one or two secondary amino groups wherein the dicarboxylate is a compound of Formula I ##STR00005## wherein R represents a bond or a hydrocarbon group with 1 to 20 carbon atoms and K.sup.+ represents an inorganic or organic cation, comprising reacting X) acrylonitrile with Y) a compound comprising two primary amino groups, wherein the adduct formed by the by reacting X) and Y) is a compound of Formula III ##STR00006## wherein R has the same meaning as in Formula I, wherein the compound of Formula III is transferred into the compound of Formula I by saponification of the two nitrile groups.

13. The synthesis according to claim 12 wherein the saponification is performed by reacting the compound of Formula III with a base.

14. The synthesis according to claim 13 wherein the base is an alkali hydroxide.

15. The synthesis according claim 12 wherein R represents a hydrocarbon group with 2 to 16 carbon atoms.

16. The synthesis according claim 12 wherein R represents a hydrocarbon group with 2 to 10 carbon atoms.

17. The synthesis according claim 12 wherein R is a non-aromatic hydrocarbon group.

18. The synthesis according claim 12 wherein the compound Y) is diaminoethane, diaminopropane, diaminobutane, diaminohexane, amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, 1,4-diaminocyclohexane, or hydrazine.

19. The synthesis according claim 12 wherein K.sup.+ represents a metal cation or a quaternary ammonium cation.

20. The synthesis according claim 12 wherein K.sup.+ is the cation of an alkali metal.

21. The synthesis according claim 12 wherein the compound Y) is used in excess.

22. The synthesis according claim 12 wherein by the saponification the nitrile groups become carboxylate groups.

Description

EXAMPLES

[0098]

TABLE-US-00001 IPDI isophorone diisocyanate H12MDI 1,1-methylenebis[4-isocyanato]cyclohexane Compound II compound of formula II DETA diethylene triamine PUD polyurethane dispersion Baxxodur ®PC 136 adduct of two mols of acrylonitrile and IPDA

Example 1

Preparation of Compound II

[0099] ##STR00004##

[0100] A 2-litre stirred flask was charged with 469.0 g of sodium hydroxide (20% by weight aqueous solution, 2.35 mol). Afterwards 197.8 g of 40% by weight aqueous solution of compound II was added to accelerate the desired saponification reaction of the starting material which is the corresponding dinitrile. The saponification reaction is also possible without the addition of compound II, but the dosage time has to be prolonged, especially at the beginning of the dosage.

[0101] The temperature of the resulting mixture was raised to 90° C. Then, 310.2 g Baxxodur® PC136 (1.12 mol) was dosed within 180 min. by keeping the reaction temperature at 90−95° C. The dosage was operated with a jacket dropping funnel which was heated to 55° C. to reduce the viscosity of compound I. After completion of the nitrile addition the dropping funnel was flushed with 102.0 g of de-ionized water and the reaction mixture was stirred at 95−100° C. for additional 120 min. to finalize the reaction and to remove the ammonia formed during saponification. A clear solution was obtained. After cooling to 20° C. addition de-ionized water was added to adjust the dry matter content to 43%.

[0102] The final product was characterized by NMR (1H- and 13C-NMR).

Example 2

[0103] Preparation of a PUD with Compound II

[0104] 600 g (0.30 mol) of a polyester diol made from adipic acid, neopentylglycol and 1,6-hexanediol (molar ratio 1/1) (OH-number 56), 26,7 g (0.014 mol) of a butanol-started polyethylene oxide, 100 g acetone and 0,3 g dibutyl tin dilaurate were charged to a vessel and stirred at 83° C. Then 89.8 g (0.404 mol) IPDI and 106.7 g (0.404 mol) H12MDI were added followed by stirring of the obtained mixture at 83° C. for 60 minutes. Then 27.0 g (0.30 mol) 1,4-butane diol were added and the reaction continued for further 120 minutes. The mixture was diluted by adding 850 g acetone. The NCO-content of the obtained mixture was determined to be 0.91% by weight (calculated: 0.93% by weight). Thereafter 73.1 g (0.10 mol of Compound II) of the solution of Example 1 were added. After 10 minutes 1300 g of water were added within 15 minutes. Then a mixture of 5.8 g (0.0562 mol) DETA and 2.7 g (0.0159 mol) IPDA were added. Finally, acetone was removed by distillation at reduced pressure.

[0105] A homogeneous polyurethane dispersion with small polyurethane particles was obtained. The polyurethane dispersion had a solids content of 36,0% by weight.

Comparison Example

[0106] Preparation of a PUD with diamino-monocarboxylic acid (analogous to the disclosure of DE-A 2 034 479)

[0107] 600 g (0.30 mol) of a polyester diol made from adipic acid, neopentylglycol and 1,6-hexanediol (molar ratio 1/1) (OH-number 56), 26,7 g (0.014 mol) of a butanol-started polyethylene oxide, 100 g acetone and 0,3 g dibutyl tin dilaurate were charged to a vessel and stirred at 83° C. Then 89.8 g (0.404 mol) IPDI and 106.7 g (0.404 mol) H12MDI were added followed by stirring of the obtained mixture at 83° C. for 60 minutes. Then 27.0 g (0.30 mol) 1,4-butane diol were added and the reaction continued for further 120 minutes. The mixture was diluted by adding 850 g acetone. The NCO-content of the obtained mixture was determined to be 0.93% by weight (calculated: 0.93% by weight). Thereafter 42.0 g (0.10 mol) of the adduct of sodium acrylate to ethylene diamine were added. After 10 minutes 1300 g of water were added within 15 minutes. Then a mixture of 5.8 g (0.0562 mol) DETA and 2.7 g (0.0159 mol) IPDA were added. Finally, acetone was removed by distillation at reduced pressure.

[0108] A homogeneous polyurethane dispersion with small polyurethane particles was obtained. The polyurethane dispersion had a solids content of 38,0% by weight.