Process for the production of polyurethane polyureas containing side chains and of aqueous dispersions of these

Abstract

The present invention relates to a process for the production of aqueous polyurethane-polyurea dispersions comprising the steps of: A) reacting primary and/or secondary monoamines or diamines A1) with cyclic carbonate containing one hydroxy group A2) such that the molar ratio of total primary and/or secondary amine groups to cyclic carbonate groups is in the range of 0.8 to 1.2; B) producing an NCO-containing polyurethane prepolymer by reacting B1) polyisocyanates with B2) polymeric polyols and/or polyamines having number average molecular weights of more than 400 to 8,000 g/mol, optionally B3) low molecular weight compounds having number average molecular weights of 17-400 g/mol selected from the group consisting of mono- and polyalcohols, mono- and polyamines, and aminoalcohols; optionally B4) isocyanate-reactive, ionically hydrophilizing compounds, and B5) the reaction products of A); C) dispersing the prepolymer from B) in water; and D) optionally reacting the remaining free NCO groups of the prepolymer from B) with monoamines, polyamines, hydrazine and/or hydrazides, wherein the molar ratio of the NH groups to the NCO groups is from 0 to 1.2, and step D) occurs partially or completely prior to or during the dispersion step C).

Claims

1. A process for preparing aqueous polyurethane-polyurea dispersions comprising a sidechain-bearing polyurethane-polyurea polymer, the process comprising the steps of A) initially A1) reacting primary monoamines, secondary monoamines or a mixture thereof comprising a group which is incorporated as sidechain into the polyurethane-polyurea polymer, with A2) cyclic carbonates containing one hydroxyl group, wherein the molar ratio of Al) and A2) is determined such that an arithmetic ratio of total primary and/or secondary amine groups to cyclic carbonate groups in the range from 0.8 to 1.2 is obtained, B) subsequently producing an NCO-containing polyurethane prepolymer by reacting B1) polyisocyanates with B2) polymeric polyols, polyamines or a mixture thereof having number average molecular weights of more than 400 to 8000 g/mol, B3) optionally low molecular weight compounds having number average molecular weights of 17-400 g/mol selected from the group consisting of monoalcohols, polyalcohols, monoamines, polyamines and amino alcohols, B4) optionally isocyanate-reactive ionically or potentially ionically hydrophilizing compounds, isocyanate-reactive nonionically hydrophilizing compounds or a mixture thereof, and B5) the reaction products from A), C) the prepolymer from B) being dispersed in water, D) optionally reacting the still free NCO groups of the prepolymer with isocyanate-reactive monoamines, polyamines, hydrazine, hydrazides or a mixture thereof, wherein the amount of substance thereof is determined such that an arithmetic ratio of isocyanate-reactive NH groups to NCO groups in the range from 0 to 1.2 is obtained, wherein said reaction D) can be effected partly or else wholly before or during the dispersing step C), and wherein the Al) components are monoamines of structural formula (1) ##STR00004## wherein R1 is selected from the group consisting of partially and/or completely fluorinated hydrocarbons having 4 to 18 carbon atoms, polysiloxanes having molecular weights of 400 to 5000 g/mol, and mixtures thereof, R2 is hydrogen or hydrocarbons having one to 18 carbon atoms, and n is from 0 to 12.

2. The process according to claim 1, wherein E) all reactions in A) are effected in aliphatic ketones or esters, and/or the prepolymer obtained from step B) is either prepared in aliphatic ketones or esters and/or after the reaction in step B) dissolved/diluted in aliphatic ketones or esters, and finally after steps A) to D) the solvent is optionally distilled off.

3. The process according to claim 1, wherein the A2) components are cyclic carbonates of structural formula (5) ##STR00005## wherein R6 is hydrogen or a hydrocarbon moiety of 1 to 18 carbon atoms, R7 is non-present or is a hydrocarbon moiety of 1 to 18 carbon atoms, and r is from 0 to 3.

4. The process according to claim 1, wherein the A2) component is 4-(hydroxymethyl)-1 ,3-dioxolan-2-one.

5. The process according to claim 1, wherein the B1) components are diisocyanates.

6. The process according to claim 1, wherein the B1) components are diisocyanates whose isocyanate groups are not attached directly to an aromatic group.

7. The process according to claim 1, wherein total B2) to B4) and D) components consist in molar terms of more than 70% of compounds having two isocyanate-reactive groups and of more than 95% of compounds having one or two isocyanate-reactive groups, wherein carboxylic acid groups are regarded as isocyanate nonreactive.

8. The process according to claim 1, wherein step D) is performed and an arithmetic ratio of isocyanate-reactive NH groups to NCO groups in the range from 0.7 to 1.2 is obtained.

9. The process according to claim 1, wherein the NCO-containing polyurethane prepolymer is obtained by reaction of 10% to 45% by weight of component B1), 30% to 80% by weight of component B2), 0% to 10% by weight of component B3), 0% to 20% by weight of component B4) and 0.1% to 40% by weight of component B5), wherein the sum total of all the components equals 100% by weight.

10. A process for preparing aqueous polyurethane-polyurea dispersions comprising a sidechain-bearing polyurethane-polyurea polymer, the process comprising the steps of A) initially A1) reacting primary diamines, secondary diamines or a mixture thereof comprising a group which is incorporated as sidechain into the polyurethane-polyurea polymer, with A2) cyclic carbonates containing one hydroxyl group, wherein the molar ratio of Al) and A2) is determined such that an arithmetic ratio of total primary and/or secondary amine groups to cyclic carbonate groups in the range from 1.8 to 2.2 is obtained, and A3) the remaining primary and/or secondary amine groups are reacted with compounds bearing one functional group reacting with primary and/or secondary amines in an addition reaction, so that no isocyanate-reactive groups are formed, wherein the amount of substance of A3) is determined such that an arithmetic ratio of total primary and/or secondary amine groups arithmetically remaining after reaction of Al) and A2) to amine-reactive groups in A3) in the range from 0.8 to 1.2 is obtained, wherein the reaction with A3) can take place after, simultaneously with or before the reaction with A2), B) subsequently producing an NCO-containing polyurethane prepolymer by reacting B1) polyisocyanates with B2) polymeric polyols, polyamines or a mixture thereof having number average molecular weights of more than 400 to 8000 g/mol, B3) optionally low molecular weight compounds having number average molecular weights of 17-400 g/mol selected from the group consisting of monoalcohols, polyalcohols, monoamines, polyamines and amino alcohols, B4) optionally isocyanate-reactive ionically or potentially ionically hydrophilizing compounds, isocyanate-reactive nonionically hydrophilizing compounds or a mixture thereof, and B5) the reaction products from A), C) the prepolymer from B) being dispersed in water, and D) optionally reacting the still free NCO groups of the prepolymer with isocyanate-reactive monoamines, polyamines, hydrazine, hydrazides or a mixture thereof, wherein the amount of substance thereof is determined such that an arithmetic ratio of isocyanate-reactive NH groups to NCO groups in the range from 0 to 1.2 is obtained, wherein said reaction D) can be effected partly or else wholly before or during the dispersing step C), and wherein the Al) components are diamines of structural formula (2) ##STR00006## wherein R3 is selected from the group consisting of partially and/or completely fluorinated hydrocarbons having 4 to 18 carbon atoms, colysiloxanes having molecular weights of 400 to 5000 g/mol, and mixtures thereof, R4 and R5 are each independently hydrogen or hydrocarbons having one to 18 carbon atoms, and p and q are each independently from 0 to 12.

11. The process according to claim 10, wherein E) all reactions in A) or only the reaction with A3) is effected in aliphatic ketones or esters, and/or the prepolymer obtained from step B) is either prepared in aliphatic ketones or esters and/or after the reaction in step B) dissolved/diluted in aliphatic ketones or esters, and finally after steps A) to D) the solvent is optionally distilled off.

12. The process according to claim 10, wherein the A2) components are cyclic carbonates of structural formula (5) ##STR00007## wherein R6 is hydrogen or a hydrocarbon moiety of 1 to 18 carbon atoms, R7 is non-present or is a hydrocarbon moiety of 1 to 18 carbon atoms, and r is from 0 to 3.

13. The process according to claim 10, wherein the A2) component is 4-(hydroxymethyl)-1,3-dioxolan-2-one.

14. The process according to claim 10, wherein the A3) components are monoisocyanates.

15. The process according to claim 10, wherein the A3) components comprise isocyanate groups not attached directly to an aromatic group.

16. The process according to claim 10, wherein the B1) components are diisocyanates.

17. The process according to claim 10, wherein the B1) components are diisocyanates whose isocyanate groups are not attached directly to an aromatic group.

18. The process according to claim 10, wherein total B2) to B4) and D) components consist in molar terms of more than 70% of compounds having two isocyanate-reactive groups and of more than 95% of compounds having one or two isocyanate-reactive groups, wherein carboxylic acid groups are regarded as isocyanate nonreactive.

19. The process according to claim 10, wherein step D) is performed and an arithmetic ratio of isocyanate-reactive NH groups to NCO groups in the range from 0.7 to 1.2 is obtained.

20. The process according to claim 10, wherein the NCO-containing polyurethane prepolymer is obtained by reaction of 10% to 45% by weight of component B1), 30% to 80% by weight of component B2), 0% to 10% by weight of component B3), 0% to 20% by weight of component B4) and 0.1% to 40% by weight of component B5), wherein the sum total of all the components equals 100% by weight.

Description

EXAMPLES

(1) The ATR-FTIR measurements were carried out using a Perkin Elmer Paragon 1000 with diamond ATR unit. The NCO values were determined by reacting a removed sample with an excess of dibutylamine and backtitration with hydrochloric acid, and are reported in % by weight.

Example 1

(2) 10 g (77.4 mmol) of 1-octylamine are initially charged at 25 C. before 9 g (76.2 mmol/98.4%) of 4-(hydroxymethyl)-1,3-dioxolan-2-one are added under agitation. The mixture heats up to 73 C. in the process. It is stirred at 75 C. for a further two hours. An IR spectrum shows complete conversion (no peak left at 1792 cm.sup.1, new peaks at 1691 cm.sup.1 and 1540 cm.sup.1).

(3) 10 g of the product obtained in this way are initially charged together with 147.2 g (72.8 mmol) of a polypropylene glycol having an average molar mass of 2022 g/mol, 41 g (40.2 mmol) of a polypropylene glycol having an average molar mass of 1020 g/mol and 12.1 g (90 mmol) of dimethylolpropionic acid and thoroughly commixed. This is followed by the addition of 104.3 g (470 mmol) of isophorone diisocyanate and 7.1 g (27 mmol) of bis(4-isocyanatocyclohexyl)methanes and the mixture is heated to 90 C. for two hours. The residual NCO value is then 6.34%. The mixture is cooled down to 60 C., 9.1 g of triethylamine are stirred in, and everything is transferred into 835 g of water (5 C.) under vigorous agitation. The dispersion is gradually admixed with a cold solution of 10 C. of 11.3 g (226 mmol) of hydrazine monohydrate in 75 g of water added by dropwise addition to obtain a storage-stable polyurethane dispersion having a dry matter content of 25%.

Example 2

(4) 10 g (76.8 mmol) of N-(2-aminoethyl)morpholine are initially charged at 25 C. before 8.84 g (74.9 mmol/97.5%) of 4-(hydroxymethyl)-1,3-dioxolan-2-one are added under agitation. The mixture heats up to 68 C. in the process. It is stirred at 70 C. for a further two hours. An IR spectrum shows complete conversion (no peak left at 1793 cm.sup.1, new peaks at 1693 cm.sup.1 and 1534 cm.sup.1).

(5) 18.84 g of the product obtained in this way are initially charged together with 402.2 g (200 mmol) of polytetramethylene glycol having an average molar mass of 2011 g/mol and 26.8 g (200 mmol) of dimethylolpropionic acid and thoroughly commixed. This is followed by the addition of 124.3 g (560 mmol) of isophorone diisocyanate and 42 g (200 mmol) of an isomeric mixture consisting of 2,2,4- and 2,4,4-trimethylhexamethylene 1,6-diisocyanate (40:60) and the mixture is heated to 85 C. for three hours. The residual NCO value is then 3.62%. The mixture is cooled down to 60 C., 21.2 g of triethylamine are stirred in, and everything is transferred into 975 g of water (5 C.) under vigorous agitation. The dispersion is gradually admixed with a cold solution of 10 C. of 41.8 g (246 mmol) of isophoronediamine in 150 g of water added by dropwise addition to obtain a storage-stable polyurethane dispersion having a dry matter content of 35%.

Example 3

(6) 10 g (70.3 mmol) of N-(3-aminopropyl)-2-pyrrolidinone are initially charged at 25 C. and 8 g (67.7 mmol/96.3%) of 4-(hydroxymethyl)-1,3-dioxolan-2-one are added under agitation. The mixture heats up to 75 C. in the process. It is stirred at 75 C. for a further five hours. An IR spectrum shows complete conversion (no peak left at 1793 cm.sup.1, new peak at 1534 cm.sup.1 and new shoulder on peak at 1654 cm.sup.1).

(7) 18 g of the product obtained in this way are initially charged together with 194.3 g (200 mmol) of a polycarbonate diol (based on 1,6-hexanediol) having an average molar mass of 971.4 g/mol, 1.8 g (20 mmol) of 1,4-butanediol and 26.8 g (200 mmol) of dimethylolpropionic acid and thoroughly commixed. This is followed by the addition of 142.8 g (850 mmol) of hexamethylene diisocyanate and the mixture is heated to 85 C. for 2.5 hours. The residual NCO value is then 7.69%. The mixture is dissolved in 200 g methyl acetate and cooled down to 35 C. 20.2 g of triethylamine are stirred in and thereafter 795 g of water (10 C.) are added under vigorous agitation. The dispersion is gradually admixed with a cold solution at 10 C. of 16.7 g (334 mmol) of hydrazine monohydrate in 75 g of water added by dropwise addition. The methyl acetate is removed in a vacuum distillation at about 200 mbar to obtain a storage-stable polyurethane dispersion which is adjusted with water to a dry matter content of 30%.

Example 4

(8) 25 g (38.2 mmol) of methyl polyalkylene glycol amine (alkylene ratio: ethylene to propylene 3:1, average molar mass 655 g/mol) are initially charged at 25 C. and 4.1 g (34.7 mmol/90.8%) of 4-(hydroxymethyl)-1,3-dioxolan-2-one are added under agitation. The mixture heats up to 28 C. in the process. It is stirred at 60 C. for three days. An IR spectrum shows complete conversion (no peak left at 1796 cm.sup.1, new peaks at 1717 cm.sup.1 and 1529 cm.sup.1).

(9) 29.1 g of the product obtained in this way are initially charged together with 493.8 g (250 mmol) of a polycaprolactone diol (initiated with neopentyl glycol) having an average molar mass of 1975 g/mol, 5.2 g (50 mmol) of neopentyl glycol and 26.8 g (200 mmol) of dimethylolpropionic acid, and dissolved in 206 g of acetone. This Is followed by the addition of 199.8 g (900 mmol) of isophorone diisocyanate and 2 g of triethylamine and the mixture is refluxed for four hours. The residual NCO value is then 2.85%. The mixture is cooled down to 30 C., 18.2 g of triethylamine are stirred in and 1500 g of water (10 C.) are added under vigorous agitation. The dispersion is gradually admixed with a cold solution at 10 C. of 17 g (283 mmol) of ethylene-diamine in 100 g of water added by dropwise addition. The acetone is removed in a vacuum distillation at about 200 mbar to obtain a storage-stable polyurethane dispersion which is adjusted with water to a dry matter content of 32%.

Example 5

(10) 50 g (77.3 mmol) of polyoxyalkylenediamine (alkylene ratio: ethylene to propylene 2:3, average molar mass 647 g/mol) are initially charged at 25 C. and 9.2 g (77.9 mmol/100.8%) of 4-(hydroxymethyl)-1,3-dioxolan-2-one are added under agitation. The mixture heats up to 30 C. in the process. It is stirred at 60 C. for three days. An IR spectrum shows complete conversion (no peak left at 1796 cm.sup.1, new peaks at 1716 cm.sup.1 and 1528 cm.sup.1). After the product has cooled down to 25 C., 7.3 g (73.7 mmol/96.3%) of n-butyl isocyanate are added under agitation. The temperature climbs to 67 C. in the process. After one hour of slow cooling down to 25 C., an IR spectrum shows complete conversion (no peak at about 2260 cm.sup.1, new peak at 1639 cm.sup.1, peak enlargement and shifting from 1528 cm.sup.1 to 1554 cm.sup.1).

(11) 66.5 g of the product obtained in this way are initially charged together with 153 g (150 mmol) of a polypropylene glycol having an average molar mass of 1020 g/mol and thoroughly commixed. This is followed by the addition of 77.7 g (350 mmol) of isophorone diisocyanate and 0.1 g of dibutyltin dilaurate and the mixture is heated to 75 C. for 2.5 hours. The residual NCO value is then 3.08%. The mixture is dissolved in 100 g of acetone and cooled down to 30 C. 615 g of water (10 C.) are added under vigorous agitation. The dispersion is gradually admixed with a cold solution at 10 C. of 7.7 g (103.5 mmol) of propylenediamine in 75 g of water added by dropwise addition. The acetone is removed in a vacuum distillation at about 200 mbar to obtain a storage-stable polyurethane dispersion which is adjusted with water to a dry matter content of 30%.

Example 6

(12) 37.2 g of ,-di(3-aminopropyl)polydimethylsiloxane (40 mmol, average molar mass 931 g/mol) are initially charged at 25 C. and 4.7 g (40 mmol/100%) of 4-(hydroxymethyl)-1,3-dioxolan-2-one are added under agitation. The mixture heats up to 40 C. in the process. It is stirred at 60 C. for one hour. An IR spectrum shows complete conversion (no peak left at 1796 cm.sup.1, new peaks at 1702 cm.sup.1 and 1541 cm.sup.1). The product is dissolved in 500 g of methyl acetate and 4.1 g (41 mmol/102.5%) of n-butyl isocyanate are added at 25 C. The temperature climbs by a further 3 C. or so in the process. After 10 min an IR spectrum shows complete conversion (no peak at about 2260 cm.sup.1, new peak at 1632 cm.sup.1, peak enlargement and shifting from 1541 cm.sup.1 to 1570 cm.sup.1).

(13) The resulting solution of 46 g of the product in 500 g of methyl acetate is initially charged together with 394.2 g (400 mmol) of a poly(hexanediol adipate)diol having an average molar mass of 985.5 g/mol and 53.6 g (400 mmol) of dimethylolpropionic acid and thoroughly commixed. This is followed by the addition of 360.8 g (1625 mmol) of isophorone diisocyanate and 3.04 g of triethylamine and the mixture is refluxed for four hours. The residual NCO value is then 4.70%. The mixture is cooled down to 40 C., 40.4 g of triethylamine are stirred in and 1760 g of water (10 C.) are then added under vigorous agitation. The dispersion is gradually admixed with a cold solution at 10 C. of 36.1 g (721 mmol) of hydrazine monohydrate in 175 g of water added by dropwise addition. The methyl acetate is removed in a vacuum distillation at about 200 mbar to obtain a storage-stable polyurethane dispersion which is adjusted with water to a dry matter content of 30%.