POLYURETHANE DISPERSIONS BASED ON RENEWABLE RAW MATERIALS

Abstract

A polyurethane dispersion PUD comprises at least one polyurethane P based on at least one polyisocyanate and at least one polyester polyol PES, wherein the polyester polyol PES is based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and/or at least one dicarboxylic acid D were at least partly derived from renewable raw materials.

Claims

1. A polyurethane dispersion PUD comprising at least one polyurethane P based on at least one polyisocyanate and at least one polyester polyol PES, wherein the polyester polyol PES is based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and/or at least one dicarboxylic acid D were at least partly derived from renewable raw materials.

2. The polyurethane dispersion according to claim 1 wherein the at least one dicarboxylic acid D is sebacic acid, azelaic acid, succinic acid, furan dicarboxylic acid or tetrahydrofuran dicarboxylic acid.

3. The polyurethane dispersion according to claim 1 wherein the at least one dicarboxylic acid D comprises sebacic acid at least partly derived from renewable raw materials, and adipic acid.

4. The polyurethane dispersion according to claim 1 wherein the at least one polyhydric alcohol A was at least partly derived from renewable raw materials.

5. The polyurethane dispersion according to claim 1, wherein the at least one polyhydric alcohol A is selected from the group consisting of aliphatic C2-C6 diols.

6. The polyurethane dispersion according to claim 1 wherein the at least one polyhydric is selected from the group consisting of 1,3-propanediol and 1,4-butanediol.

7. The polyurethane dispersion according to claim 1, wherein the polyurethane comprises at least one chain extender.

8. The polyurethane dispersion according to claim 1, wherein the polyurethane dispersion is aqueous.

9. A process for producing a polyurethane dispersion, which process comprises the step of reacting at least one polyisocyanate and at least one polyester polyol PES, wherein the polyester polyol PES is based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and/or at least one dicarboxylic acid D were at least partly derived from renewable raw materials.

10. The process according to claim 9 comprising the steps of: I. preparing a polyurethane by reaction of a) at least one polyfunctional isocyanate having 4 to 30 carbon atoms, b) diols whereof b1) 10 to 100 mol %, based on the total amount of diols (b), have a molecular weight of 500 to 5000, and b2) 0 to 90 mol %, based on the total amount of diols (b), have a molecular weight of 60 to 500 g/mol, c) optionally further polyfunctional compounds other than the diols (b) and having reactive groups in the form of alcoholic hydroxyl groups or primary or secondary amino groups, and d) monomers having at least an isocyanate group or at least an isocyanate-reactive group which are other than the monomers (a), (b) and (c) and which further bear at least a hydrophilic group or a potentially hydrophilic group, whereby polyurethanes are rendered dispersible in water, to form a polyurethane in the presence of a solvent S, and II. then dispersing the polyurethane in water, III. wherein polyamines may optionally be added after or during step II, wherein diol b1) comprises at least one polyester polyol PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and/or at least one dicarboxylic acid D were at least partly derived from renewable raw materials.

11. A polyurethane dispersion obtained by the process according to claim 9.

12. A method comprising coating, impregnation or adhesive bonding of wood, wood veneer, paper, paperboard, card, textile, leather, leather substitute, batting, plastics surfaces, glass, ceramic, mineral-type building materials, apparel, vehicular interior trim, vehicles, metals or coated metals, with the polyurethane dispersion of claim 1.

13. A coating composition comprising the aqueous polyurethane dispersion PUD according to claim 1.

Description

EXAMPLES

[0195] Polyesterol 1 is formed from sebacic acid (from renewable raw materials), adipic acid (molar ratio 1/1) and 1,3-propanediol (from renewable raw materials), molar mass 1400 g/mol.

[0196] Polyesterol 2 is formed from adipic acid, neopentyl glycol and 1,6-hexanediol (molar ratio 1/1), molar mass 1400 g/mol.

Example 1

[0197] A stirred tank fitted with a thermometer and a reflux condenser was initially charged with 420 g (0.30 mol) of polyesterol 1, 27.0 g of 1,4-butanediol, 100 g of acetone and 0.30 ml of dibutyltin dilaurate followed by heating to 65° C. This was followed by the admixture of 89.8 g (0.404 mol) of isophorone diisocyanate and 106.7 g of 4,4′-dicyclohexylmethane diisocyanate and stirring at 95° C. This was followed by dilution with 850 g of acetone after 210 min.

[0198] The NCO content of the solution was determined as 1.16% (computed: 1.04%).

[0199] The solution was cooled to 50° C. and admixed with 42.0 g (0.10 mol) of a 40% aqueous solution of the Michael adduct of ethylenediamine onto sodium acrylate. This was followed by dispersal by admixture of 1200 g of water. Immediately following dispersal, a mixture of 50 g of water, 2.7 g (0.016 mol) of isophoronediamine and 5.8 g (0.056 mol) of diethylenetriamine was admixed.

[0200] After distillation of the acetone, a finely divided polyurethane dispersion having a solids content of 37.2% was obtained.

Example 2 (Comparative)

[0201] A stirred tank fitted with a thermometer and a reflux condenser was initially charged with 420 g (0.30 mol) of polyesterol 2, 27.0 g of 1,4-butanediol, 100 g of acetone and 0.30 ml of dibutyltin dilaurate followed by heating to 65° C. This was followed by the admixture of 89.8 g (0.404 mol) of isophorone diisocyanate and 106.7 g of 4,4′-dicyclohexylmethane diisocyanate and stirring at 95° C. This was followed by dilution with 850 g of acetone after 210 min.

[0202] The NCO content of the solution was determined as 1.16% (computed: 1.04%).

[0203] The solution was cooled to 50° C. and admixed with 42.0 g (0.10 mol) of a 40% aqueous solution of the Michael adduct of ethylenediamine onto sodium acrylate. This was followed by dispersal by admixture of 1200 g of water. Immediately following dispersal, a mixture of 50 g of water, 2.7 g (0.016 mol) of isophoronediamine and 5.8 g (0.056 mol) of diethylenetriamine was admixed.

[0204] After distillation of the acetone, a finely divided polyurethane dispersion having a solids content of 38.4% was obtained.

[0205] Floats were prepared from

[0206] 120 g of Lepton Schwarz NB,

[0207] 150 g of Lepton Filler FCG,

[0208] 400 g of polyurethane dispersion, and

[0209] 100 g of Corial Ultrasoft NT

and thickened with Lepton Paste VL to an efflux viscosity of 35 sec in the 4 mm Ford cup. These floats were reverse roll coated at 8.0 g/ft.sup.2 onto a full-grain leather.

[0210] Lepton® Schwarz NB is a pigment formulation from BASF SE for application in aqueous finishes which is based on carbon black.

[0211] Lepton Filler FCG is an aqueous dispersion of inorganic delusterants with casein, fat and waxes from BASF SE for use in aqueous finishes.

[0212] Corial® Ultrasoft NT is an aqueous acrylate polymer dispersion from BASF SE for use in aqueous finishes.

[0213] Lepton® Paste VL is a PU dispersion in admixture with water and comparatively highly hydric alcohols from BASF SE for use in aqueous finishes.

Table 1 Summarizes the Test Results:

[0214]

TABLE-US-00001 Example 3 (poly- Example 4 (poly- urethane dispersion urethane dispersion from Example 1) from Example 2) DIN EN ISO 11644 7.4 8.1 adherence of finish (N/cm) DIN EN ISO 5402 flex life no damage no damage dry 100 000 x DIN EN ISO 5402 flex life no damage no damage dry at −10° C. 30 000 x

[0215] Polyurethane dispersions of the present invention, which are based on renewable raw materials, have the same performance characteristics as polyurethane dispersions formed from petrochemical raw materials.