POLYURETHANE

Abstract

A polyurethane obtainable by reacting a polyisocyanate, a polyol, and/or a chain extender, wherein at least one of the polyisocyanate and chain extender comprises a C14 to C32 alkyl group. The polyurethane is particularly suitable for use in coating, elastomer and adhesive/sealant compositions.

Claims

1. A polyurethane obtained by reacting a polyisocyanate, a polyol, and/or a chain extender, wherein at least one of the polyisocyanate and chain extender comprises a C14 to C32 alkyl group.

2. A polyurethane according to claim 1 wherein the polyisocyanate and/or chain extender comprises a C16 to C26 alkyl group.

3. A polyurethane according to claim 1 wherein the polyisocyanate is of the Formula (1);
OCN(CH.sub.2).sub.nNCO (1) wherein n is in the range from 14 to 30.

4. A polyurethane according to claim 1 wherein the polyisocyanate is heptadecane 1,16-diisocyanate.

5. A polyurethane according to claim 1 wherein the chain extender is of the Formula (2);
X(CH.sub.2).sub.nX (2) wherein each X is independently OH or NH.sub.2, and n is in the range from 16 to 32.

6. A polyurethane according to claim 1 wherein the chain extender is 1,18-heptadecanediol and/or 1,26-hexacosanediol.

7. A polyurethane according to claim 1 wherein the polyol comprises a polyester polyol.

8. A polyurethane according to claim 1 wherein the polyisocyanate comprises aromatic polyisocyanate.

9. A polyurethane according to claim 1 comprising 2 to 70% by weight of isocyanate of Formula (1) and/or 1 to 20 by weight chain extender of Formula (2) wherein the polyisocyanate is of the Formula (1);
OCN(CH.sub.2).sub.nNCO (1) wherein n is in the range from 14 to 30, and wherein the chain extender is of the Formula (2);
X(CH.sub.2).sub.nX (2) wherein each X is independently OH or NH.sub.2, and n is in the range from 16 to 32.

10. A polyurethane according to claim 2 comprising 0.5 to 8% by weight of C16 to C26 alkyl groups.

11. A polyurethane according to claim 10 wherein the C16 to C26 alkyl groups are exclusively derived from polyisocyanate and/or chain extender.

12. A process for preparing a polyurethane which comprises reacting a polyisocyanate, a polyol and/or a chain extender, wherein at least one of the polyisocyanate and chain extender comprises a C14 to C32 alkyl group.

13. The process according to claim 12 wherein the polyisocyanate is reacted with the polyol to form an isocyanate-terminated prepolymer.

14. An adhesive and/or sealant composition comprising a polyurethane which comprises the reaction residues of a polyisocyanate, a polyol, and/or a chain extender, wherein at least one of the polyisocyanate and chain extender comprises a C14 to C32 alkyl group, wherein the polyisocyanate optionally comprises an aromatic polyisocyanate.

15. An elastomer composition comprising a polyurethane which comprises the reaction residues of a polyisocyanate, a polyol, and/or a chain extender, wherein at least one of the polyisocyanate and chain extender comprises a C14 to C32 alkyl group, wherein the polyisocyanate optionally comprises an aromatic polyisocyanate.

16. (canceled)

17. A polyurethane according to claim 3 wherein n is in the range from 14 to 28.

18. A polyurethane according to claim 5 wherein n is in the range from 16 to 30.

19. A polyurethane according to claim 5 wherein each X is OH.

20. A polyurethane according to claim 9 comprising 4 to 60% by weight of isocyanate of Formula (1) and/or 1.5 to 15% by weight chain extender of Formula (2).

21. A polyurethane according to claim 10 comprising 1 to 6% by weight of C16 to C26 alkyl groups.

Description

EXAMPLES

Example 1

[0109] 100 g methyl oleate (purified by aluminium-oxide treatment) was heated to 100 C. 13 ppm of ([1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylider]dichloro[(2-isopropoxy)(5-trifluoracetamido)benzyliden]ruthenium(II)) was dissolved in 1 ml toluene, and this was added to the methyl oleate.

[0110] After 30 seconds, 43.6% conversion was reached, and after 120 seconds, the reaction equilibrium conversion was reached. The resulting reaction mixture contained 24.8% 9-octadecene, 25.2% 9-octadecenedioic acid dimethyl ester and approximately 50% methyl oleate according to Gas Chromatography analysis. The reaction mixture was contacted with a treated clay (5 g Tonsil 210FF) while stirring at 80 C. for 60 minutes. This mixture was filtered over filter paper to give an essentially catalyst-free product.

[0111] The catalyst-free product was purified using fractional distillation under vacuum of 2 to 9 mbar, by first distilling off the alkene and methyl oleate, and then collecting dimethyl octadecenedioate in the temperature range of 220-240 C. Gas Chromatography analysis indicated a purity of >95%.

[0112] 200 g dimethyl octadecenedioate was charged into a 400 ml volume hydrogenation autoclave vessel, 0.18 g palladium 5% on carbon hydrogenation catalyst was added, and the autoclave heated to 160 C. under 15 bar of hydrogen for 45 minutes, after which the hydrogen uptake has stopped, indicating reaction completion. The catalyst was filtered, resulting in dimethyl octadecanedioate (dimethyl ester of C18 diacid) at >95% purity according to Gas Chromatography analysis.

[0113] 2.9 g Zn(2-ethylhexanoate).sub.2(8 mmol) and 0.3 g NaBH.sub.4 (8 mmol) were added to 150 ml diisopropyl ether and heated under nitrogen to 70 C. The mixture was stirred for 20 minutes (hydrogen evolved). 32 g dimethyl octadecanedioate (0.2 mol ester groups) was added and 57 g PMHS (0.88 mol) was dosed in 45 minutes. The mixture was maintained under reflux. After 4 hours, gelation of the mixture occurred. The gel was cooled and 74 g KOH dissolved in 90 g methanol was added carefully (exothermic reaction). The gel dissolved during addition. The reaction temperature increased to 50 C. 50 ml water and 50 ml ether were added and the mixture was stirred for 45 minutes. The phases were separated. The organic phase was washed with water and concentrated with the use of a rotavap. The product (8 g) was distilled using the bulb-to-bulb distillation and 7 g of distillate (OHV=387 mg KOH/g) was obtained. The water phase was washed with diethyl ether. The ether was evaporated and 10 g of 1,18-octadecanediol having a hydroxyl value of 392 mg KOH/g was obtained.

[0114] In the following examples, this 1,18-octadecanediol is referred to as C18 diol.

Example 2

[0115] 100 g methyl erucate (purified by aluminium-oxide treatment) was heated to 100 C. 105 ppm of ([1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylider]dichloro[(2-isopropoxy) (5-trifluoracetamido)benzyliderVuthenium(II) was dissolved in 1 ml toluene, and this was added to the methyl erucate.

[0116] After 30 seconds, the reaction equilibrium conversion was reached. The resulting reaction mixture contained 20.6% 9-octadecene, 28.4% 13-hexacosenedioic acid dimethyl ester and approximately 50% methyl erucate according to Gas Chromatography analysis.

[0117] In order to produce 1,26-hexacosanediacid (C26 diacid) from this reaction mixture, the same steps were followed as given above in Example 1 for octadecanedioic acid (C18 diacid). However, the fractional distillation step was modified in that the product (dimethyl hexacosenedioiate) remained in the bottom fraction of the distillation due to its high molecular weight.

[0118] 3.0 g Zn(2-ethylhexanoate).sub.2 (8 mmol) and 0.3 g NaBH.sub.4 (8 mmol) were added to 300 ml diisopropyl ether and heated under nitrogen to 70 C. The mixture was stirred for 20 minutes (hydrogen evolved). 43.1 g dimethyl hexacosenedioiate (0.2 mol ester groups) was added and 57 g PMHS (0.88 mol) was dosed in 45 minutes. The mixture was maintained under reflux. After 7 hours, gelation of the mixture occurred. The gel was cooled and 75 g KOH dissolved in a mixture of 10 g water/200 g methanol was added carefully (exothermic reaction). The gel dissolved during addition. The reaction temperature increased to 45 C. 150 ml water was added and the mixture was stirred for 45 minutes. Toluene was added to prevent solidification of the mixture. The phases were separated. The organic phase was washed with water and concentrated with the use of a rotavap. The product was distilled using the bulb-to-bulb distillation and 23 g of 1,26-hexacosanediol having a hydroxyl value of 270 mg KOH/g was obtained.

[0119] In the following examples, this 1,26-hexacosanediol is referred to as C26 diol.

Example 3

[0120] This is a comparative example, not according to the invention.

[0121] Ingredients:

[0122] 100 g Priplast 3192 (polyester diol, ex Croda)

[0123] 11.9 g dimethylolpropionic acid (DMPA)

[0124] 3.7 g hexanediol (HDO)

[0125] 59.6 g isophorone diisocyanate (IPDI)

[0126] 24.5 g N-methyl pyrrolidone (NMP)

[0127] 267 g water

[0128] 4.5 g ethylene diamine (EDA)

[0129] 8.7 g triethylamine (TEA)

[0130] The Priplast 3192, DMPA and NMP (solvent) were dried at 120 C. under nitrogen. After cooling to 70 C., DBTL (dibutyl tin laurate) catalyst (0.05%wt on pre-polymer) and IPDI were added (IPDI slowly) to produce a prepolymer, during approximately 3 hours. When the NCO % reached 4.1, the hexanediol was added to the reaction until the desired NCO % had been reached. TEA was then added at 60 C. to neutralize the DMPA carboxylic acid groups, during 0.5 to 1 hour, followed by cooling to 40-55 C. The resultant prepolymer was dispersed in demineralised water, by slowly adding for 1 hour under vigorous stirring. The prepolymer was chain extended at 25 C. with EDA, by adding drop-wise and reacting for 2 hours. The resulting product was a 40% solids polyurethane dispersion (PUD). Acetone was used as a processing aid, to reduce viscosity, and was distilled off from the final PUD.

Example 4

[0131] Ingredients:

[0132] 100 g Priplast 3192 (polyester diol, ex Croda)

[0133] 11.9 g dimethylolpropionic acid (DMPA)

[0134] 7.3 g C18-diol (produced in Example 1)

[0135] 59.6 g isophorone diisocyanate (IPDI)

[0136] 24.5 g N-methyl pyrrolidone (NMP)

[0137] 267 g water

[0138] 4.5 g ethylene diamine (EDA)

[0139] 8.7 g triethylamine (TEA)

[0140] The procedure of Example 3 was repeated except that C18 diol was used instead of hexanediol.

Example 5

[0141] Ingredients:

[0142] 100 g Priplast 3192 (polyester diol, ex Croda)

[0143] 11.9 g dimethylolpropionic acid (DMPA)

[0144] 7.3 g C26-diol (produced in Example 2)

[0145] 59.6 g isophorone diisocyanate (IPDI)

[0146] 24.5 g N-methyl pyrrolidone (NMP)

[0147] 267 g water

[0148] 4.5 g ethylene diamine (EDA)

[0149] 8.7 g triethylamine (TEA)

[0150] The procedure of Example 3 was repeated except that C26 diol was used instead of hexanediol.

Example 6

[0151] The PUDs produced in Examples 3, 4 and 5 were subjected to various test procedures and the results are shown in Table 1.

TABLE-US-00001 TABLE 1 Example 3 (Comp) 4 5 Chain extender HDO C18 diol C26 diol Particle size 100 nm 97.8 nm 74 nm Konig hardness 60 s 78 s 41 s Water absorption 5% 4% 4% (24 hours/RT) Chemical resistance to 5 3 2 ethanol (50%, 1 hour) Chemical resistance to 5 3-4 2 acetic acid (1 hour)

[0152] The results in Table 1 show that compared to Comparative Example 3, the polyurethane dispersion of Example 4 has improved hardness and the polyurethane dispersions of both Examples 4 and 5 have a lower water absorption and improved chemical resistance to ethanol and acetic acid (0=undamaged, 5=complete damage).

[0153] The above examples illustrate the improved properties of a polyurethane according to the present invention.