A POLYOL BASED ON DIMER FATTY ACID RESIDUES AND THE CORRESPONDING POLYURETHANES

Abstract

The present invention relates to a polyol comprising a) at least one dimer fatty residue selected from a dimer fatty diacid residue and a dimer fatty diol residue; and b) at least one residue of a linear or branched C17 to C32 dicarboxylic acid or diol; wherein the polyol comprises at least two hydroxyl end groups. The invention also relates to a a polyurethane comprising the polyol, the use of the polyol and a method of making the polyurethane.

Claims

1. A polyol comprising: a) at least one dimer fatty residue selected from a dimer fatty diacid residue and a dimer fatty diol residue; and b) at least one residue of a linear or branched C17 to C32 dicarboxylic acid or diol; wherein the polyol comprises at least two hydroxyl end groups.

2. A polyol as claimed in claim 1 wherein the C17 to C32 dicarboxylic acid or diol is a linear dicarboxylic acid or diol.

3. A polyol as claimed in claim 1 wherein the weight ratio of a) to b) in the polyol is in the range 90:10 to 30:70.

4. A polyol as claimed in claim 1 wherein the weight % of a) in the polyol is at least the weight % of b) in the polyol.

5. A polyol as claimed in claim 1 wherein the C17 to C32 dicarboxylic acid or diol is a C18 to C26 dicarboxylic acid or diol.

6. A polyol as claimed in claim 1 wherein the C17 to C32 dicarboxylic acid or diol is derived from a C17 to C32 diacid or dialkyl ester which is obtained by a metathesis reaction.

7. A polyol as claimed in claim 1 which further comprises: c) at least one residue of a C2 to C16 acid or alcohol which has at least 2 functional groups selected from a carboxylic acid group, a hydroxyl group and mixtures thereof.

8. A polyol as claimed in claim 7 wherein c) is at least one residue of a diol comprising from 2 to 10 carbon atoms.

9. A polyol as claimed in claim 7 wherein the weight % of a) in the polyol is greater than the weight % of c) in the polyol.

10. A polyol as claimed in claim 7 wherein the weight % of b) in the polyol is greater than the weight % of c) in the polyol.

11. A polyurethane comprising a polyol as claimed in claim 1.

12. A polyurethane as claimed in claim 11 wherein the polyurethane is a polyurethane elastomer with a tensile strength at break of at least 80 N when measured according to ISO 527-2.

13. A polyurethane as claimed in claim 11 wherein the polyurethane is a polyurethane elastomer with a Shore A hardness of at least 70 when measured according to ISO 868.

14. A polyurethane as claimed in claim 11 wherein the polyurethane is a polyurethane elastomer with a 100% modulus of at least 20 kg/cm.sup.2 when measured according to ISO 527-2.

15. A method of making a polyurethane comprising reacting a polyol as claimed in claim 1 with an isocyanate to form: (i) the polyurethane; or (ii) an isocyanate-terminated pre-polymer which is then reacted with a chain extender to form the polyurethane.

16. (canceled)

17. An adhesive, coating, elastomer or sealant comprising a polyol as claimed in claim 1.

18. A polyol as claimed in claim 1 wherein the weight ratio of a) to b) in the polyol is in the range 85:15 to 45:55.

19. A polyol as claimed in claim 1 wherein the C17 to C32 dicarboxylic acid or diol is a C18 or C26 dicarboxylic acid or diol.

20. A polyol as claimed in claim 6 wherein the C17 to C32 dicarboxylic acid or diol is derived from a C17 to C32 diacid or dialkyl ester which is obtained by a self-metathesis reaction.

21. A polyol as claimed in claim 7 wherein c) is at least one residue of a diol comprising from 5 to 8 carbon atoms.

Description

EXAMPLES

[0182] The present invention will now be described further by way of example only with reference to the following Examples. All parts and percentages are given by weight unless otherwise stated.

[0183] It will be understood that all tests and physical properties listed have been determined at atmospheric pressure and room temperature (i.e. about 20 C.), unless otherwise stated herein, or unless otherwise stated in the referenced test methods and procedures.

[0184] Tests of polyurethane dispersions in coatings were performed at 23 C. with a relative humidity of 50%.

[0185] Compounds as used in the following examples are identified as follows: [0186] 1,4-butanediola bio-based version is available from BioAmber [0187] 1,6-hexanediol [0188] Adipic acid (C.sub.6 dicarboxylic acid)a bio-based version is available from Verdezyne [0189] PRIPOL 1006 (TM) dimer fatty diacidhydrogenated C.sub.36 dicarboxylic acid ex Croda [0190] PRIPOL 2033 (TM) dimer fatty diolhydrogenated C.sub.36 dimer diol ex Croda [0191] C18 diacidSaturated linear C18 dicarboxylic acid produced according to Example M1 below [0192] C26 diacidSaturated linear C26 dicarboxylic acid produced according to Example M2 below [0193] Diethyleneglycol (DEG) [0194] Poly(tetramethylene ether) glycol (PTMEG also known as polyTHF) e.g. PTMEG 250=Mw 250 and PTMEG 2000=Mw 2000 [0195] Dimethylolpropionic acid (DMPA) [0196] Isophorone diisocyanate (IPDI) [0197] N-methyl pyrrolidone (NMP) [0198] Ethylene diamine (EDA) [0199] Triethylamine (TEA)

[0200] Test methods: [0201] Number average molecular weight was determined by end group analysis with reference to the hydroxyl value. [0202] Weight average molecular weight was determined by end group analysis with reference to the hydroxyl value. [0203] The hydroxyl value is defined as the number of mg of potassium hydroxide equivalent to the hydroxyl content of 1 g of sample, and was measured by acetylation followed by hydrolysation of excess acetic anhydride. The acetic acid formed was subsequently titrated with an ethanolic potassium hydroxide solution. [0204] The acid value is defined as the number of mg of potassium hydroxide required to neutralise the free fatty acids in 1 g of sample, and was measured by direct titration with a standard potassium hydroxide solution. [0205] The isocyanate (NCO) value or content is defined as the weight % content of isocyanate in the sample and was determined by reacting with excess dibutylamine, and back titrating with hydrochloric acid. [0206] Hardness was measured using a Shore A meter on a 10 mm thick sample according to ISO 868. A mean value of 10 readings was calculated. [0207] Knig Hardness was measured using DIN ISO 2815 [0208] Particle size of polyurethane dispersions was measured with a Zetasizer using dynamic light scattering [0209] Elongation was measured using an Instron tensile tester according to ISO 527-2 norm. [0210] Tensile Strength was measured using an Instron tensile tester according to ISO 527-2 norm. [0211] Modulus was calculated as the tensile strength required to achieve a predetermined elongation. [0212] Hydrolysis Samples were aged by placing dumbells of the material in a climate chamber at 70 C and >98% relative humidity for periods of 2 and 4 weeks. The elongation at break of the aged samples was determined as above and the values compared to the original figures (on percentage retention terms).

Example M1

Production of C18 Diacid

[0213] 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-imidazolidinyliden]dichloro[(2-isopropoxy)(5-trifluoracetamido)benzyliden]ruthenium(II)) was dissolved in 1 ml toluene, and this was added to the methyl oleate.

[0214] 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 treated with a treated clay (Tonsil 210FF, 5 g) while stirring at 80 C. for 60 minutes. This mixture was filtered over filter paper to give an essentially catalyst-free product.

[0215] 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%.

[0216] Purified dimethyl octadecenedioate (200 g) 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, >95% purity according to Gas Chromatography analysis.

[0217] Dimethyl octadecanedioate (150 g) was combined with 300 g methanol, 100 g water and 200 g of a 50% KOH solution in water. This was heated to reflux for 1 h, and subsequently cooled to 55 C. 185 g of an 85% H.sub.3PO.sub.4 solution in 750 ml water was added gradually upon which a solid precipitate was formed which was stirred for 1 h. The solids were filtered off and washed with water until the filtrate had neutral pH as indicated using indicator paper. The solids were dried under vacuum (approx. 10 mbar, 60 C.) until no further mass loss occurred, resulting in 1,18-octadecanedioic acid. In the following examples, this 1,18-octadecanedioic acid will be referred to as C18 diacid.

Example M2

Production of C26 Diacid

[0218] 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-imidazolidinyliden]dichloro[(2-isopropoxy)(5-trifluoracetamido)benzyliden]]ruthenium(II) was dissolved in 1 ml toluene, and this was added to the methyl erucate.

[0219] 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.

[0220] In order to produce 1,26-hexacosanediacid (C26 diacid) from this reaction mixture, the same steps were followed as given above in Example M1 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. In the following examples, the 1,26-hexacosanedioic acid produced by this example will be referred to as C26 diacid.

Comparative Example P1

Formation of Polyol 1 (a Polyester Polyol not According to the Invention)

[0221] 50 parts by weight Pripol 1006, 50 parts Adipic acid (C6) and 59.3 parts hexanediol (C6) were charged to a reactor equipped with a gas inlet, a stirrer, a thermometer and a condenser. The temperature in the reactor was raised to 220-230 C. under normal pressure in a nitrogen atmosphere. An esterification reaction was conducted under these conditions until the desired acid and hydroxyl value were obtained. The evaluation results of the obtained polyester polyol gave an acid value <1 mg KOH/g and a hydroxyl value of 56 mg KOH/g, equivalent to a number average molecular weight (Mn) of about 2000.

Example P2

Formation of Polyol 2 (a C18 Diacid Based Polyester Polyol)

[0222] 50 parts by weight Pripol 1006 (C36 dimer fatty diacid), 50 parts C18-diacid (produced according to Example M1) and 36.9 parts hexanediol (C6) were charged to a reactor equipped with a gas inlet, a stirrer, a thermometer and a condenser. The temperature was raised to 220-230 C. under normal pressure in a nitrogen atmosphere. An esterification reaction was conducted under these conditions until the desired acid and hydroxyl value were obtained. The evaluation results of the obtained polyester polyol gave an acid value <1 mg KOH/g and a hydroxyl value of 56 mg KOH/g, equivalent to a number average molecular weight (Mn) of about 2000.

Example P3

Formation of Polyol 3 (a C18 Diacid Based Polyester Polyol)

[0223] 80 parts by weight Pripol 1006 (C36 dimer fatty diacid), 20 parts C18-diacid (produced according to Example M1) and 31.3 parts hexanediol (C6) were charged to a reactor equipped with a gas inlet, a stirrer, a thermometer and a condenser. The temperature was raised to 220-230 C. under normal pressure in a nitrogen atmosphere. An esterification reaction was conducted under these conditions until the desired acid and hydroxyl value were obtained. The evaluation results of the obtained polyester polyol gave an acid value <1 mg KOH/g and a hydroxyl value of 56 mg KOH/g, equivalent to a number average molecular weight (Mn) of about 2000.

Example P4

Formation of Polyol 4 (a C18 Diacid Based Polyol Including DEG)

[0224] 50 parts by weight Pripol 1006 (C36 dimer fatty diacid), 50 parts C18-diacid (produced according to Example M1) and 32.8 parts Diethyleneglycol (DEG) were charged to a reactor equipped with a gas inlet, a stirrer, a thermometer and a condenser. The temperature was raised to 220-230 C. under normal pressure in a nitrogen atmosphere. An esterification reaction was conducted under these conditions until the desired acid and hydroxyl value were obtained. The evaluation results of the obtained polyol gave an acid value <1 mg KOH/g and a hydroxyl value of 56 mg KOH/g, equivalent to a number average molecular weight (Mn) of about 2000.

Example P5

Formation of Polyol 5 (a C18-Diacid Based Polyester Polyol Including Dimer Fatty Diol)

[0225] 100 parts by weight C18-diacid (produced according to Example M1) and 318.2 parts Pripol 2033 (C36 dimer fatty diol) were charged to a reactor equipped with a gas inlet, a stirrer, a thermometer and a condenser. The temperature was raised to 220-230 C. under normal pressure in a nitrogen atmosphere. An esterification reaction was conducted under these conditions until the desired acid and hydroxyl value were obtained. The evaluation results of the obtained polyester polyol gave an acid value <1 mg KOH/g and a hydroxyl value of 89 mg KOH/g, equivalent to a number average molecular weight (Mn) of about 1200.

Example P6

Formation of Polyol 6 (a C18-Diacid Based Poly(Ether)Ester Polyol)

[0226] 58 parts by weight Pripol 1006 (C36 dimer fatty diacid), 50 parts C18-diacid (produced according to Example M1) and 88 parts PTMEG 250, were charged to a reactor equipped with a gas inlet, a stirrer, a thermometer and a condenser. The temperature was raised to 220-230 C. under normal pressure in a nitrogen atmosphere. An esterification reaction was conducted under these conditions the until the desired acid and hydroxyl value were obtained. The evaluation results of the obtained polyol gave an acid value <1 mg KOH/g and a hydroxyl value of 56 equivalent to a number average molecular weight (Mn) of about 2000.

[0227] A comparison of the components of the polyols P1 to P6 is given in Table 1 below for guidance.

TABLE-US-00001 TABLE 1 Comparison of the ingredients of the polyols P1 to P6 Components of the polyol (parts by weight/wt %) P1 P2 P3 P4 P5 P6 Alcohol component PRIPOL 1006 50/ 50/ 80/ 50/ 58/ (C36 dimer fatty diacid) 31.4 wt % 36.5 wt % 61 wt % 37.7 wt % 30 wt % Adipic acid 50/ 31.4 wt % C18-diacid 50/ 20/ 50/ 100/ 50/ 36.5 wt % 15.2 wt % 37.7 wt % 23.9 wt % 25 wt % Acid component(s) Hexanediol 59.3/ 36.9/ 31.3/ 37.2 wt % 27 wt % 23.8 wt % Diethylene glycol 32.8/ 24.6 wt % Pripol 2033 318.2/ (C36 dimer fatty diol) 76.1 wt % PTMEG 250 88/ 45 wt %

Example PUD6

Polyurethane Dispersion Formed from Polyol P6 Compared with Comparative PUD

[0228] A polyurethane dispersion (PUD6) was formed using Polyol P6. The PUD synthesis was performed using the pre-polymer process.

Ingredients of the PUD:

[0229]

TABLE-US-00002 100 g Polyol P6 13 g Dimethylolpropionic acid (DMPA) 60.1 g Isophorone diisocyanate (IPDI)) 25 g N-methyl pyrrolidone (NMP) 371.14 g water 4.3 g Ethylene diamine (EDA) 9.6 g Triethylamine (TEA)

[0230] The polyol P6, DMPA and NMP (solvent) were dried at 120 C. under nitrogen. After cooling to 70 C., dibutyl tin dilaurate (DBTL) catalyst (0.05% wt on pre-polymer) and slowly IPDI (aliphatic diisocyanate) are added to the reaction until the desired NCO % has been reached. Then at 60 C. TEA is added for neutralising the DMPA carboxylic acid groups, during 0.5 to 1 hour, followed by cooling to 40-55 C. Then the prepolymer is dispersed in demineralised water, adding slowly during 1 hour under vigorous stirring. At 25 C. the prepolymer is chain extended with EDA, added drop-wise and reacted 2 hours. Result is a 40% solids PUD. Acetone can be used as processing aid, to reduce viscosity, and distilled off from the final PUD.

[0231] A comparative PUD using 100 g of a PTMEG Mw2000 polyol instead of polyol P6 was made following the same steps as above.

[0232] A comparison of selected physical properties of PUD6 and the comparative PUD is given in Table 2 below.

Evaluation Methods for Polyurethane Dispersions:

[0233] Particle size: Zetasizer using dynamic light scattering
Knig hardness: tested using DIN ISO 2815
Chemical resistance: Spot test, rating 0=undamaged to 5=complete damage
Water absorption: determined by measuring weight increase after 24 h in demineralised water at room temperature

TABLE-US-00003 TABLE 2 Evaluation of coating PUD6 from polyol P6 compared with comparative PUD PUD6 using Comparative PUD Polyol P6 using PTMEG Particle size nm 85.4 102 Konig hardness s 32 44 Water absorption (24 h) 4 8 (% weight increase) Chemical resistance to: Ammonia (10%) (2 min) 0-1 2-3 EtOH (50%, 1 hour) 3 4-5 Water (16 hour) 2 3 Acetic acid (1 hour) 4 5

[0234] It can be seen from the results in the above Table 2 that PUD6 based on the C18 diacid based polyol P6 has a similar particle size to the comparative PUD. PUD6 has improved water absorption resistance compared with the PTMEG based PUD. Furthermore the overall resistance to the tested chemicals is higher for PUD6 than for the comparative PUD.

Examples E1 to E5

Polyurethane Elastomers Formed from Polyols P1 to P5

[0235] Polyurethane elastomers were made from Polyol 1 of Comparative Example P1 (E1comparative example), Polyol 2 of Example P2 (E2), Polyol 3 of Example P3 (E3), Polyol 4 of Example P4 (E4) and Polyol 5 of Example P5 (E5)

[0236] The polyurethane elastomers were prepared using 1 part by weight of Polyol 1, 2, 3, 4 or 5, 0.6 parts 1,4-butanediol (BDO) as a chain extender, and 1.7 parts 4,4-5 diphenylmethane diisocyanate (MDI), using a one-shot method.

[0237] To form the elastomer E1 to E5, Polyol 1, 2, 3, 4 or 5 and 1,4-butanediol (BDO) chain extender were blended and pre-heated at 50 C. and degassed in a degassing chamber. The Polyol and BDO were mixed thoroughly, after which molten 4,4-diphenylmethane diisocyanate (MDI) was added. The reaction mixture was stirred efficiently, transferred to the degassing chamber for a few minutes until significant viscosity increase occurred. The mixture was then poured into a preheated 100 C. steel mould. The mould was closed and transferred to an oven at 100 C. After 2 hours the elastomer was de-moulded and further cured at 100 C. for another 18 hours.

[0238] The physical properties of each elastomer E1 to E5 were determined and are shown in Table 3 below.

TABLE-US-00004 TABLE 3 Physical properties of Elastomers E1 to E5 with component ratio of 1 part polyol/0.6 parts BDO/1.7 parts MDI E1 E2 E3 E4 E5 Hardness (Shore A) 50 86 80 79 83 Tensile strength at break (N) 60 176 92 118 294 Elongation (%) 830 620 840 715 427 100% modulus (kg/cm.sup.2) 11 45 22 42 79 300% modulus (kg/cm.sup.2) 19 69 35 54 123 Hydrolysis resistance: performance of Elastomers after immersion for 1 week @90 C. in water Retention of Elongation (%) 85 100 97 * 95 * = not evaluated

[0239] It can be seen from the results in the above Table 3 and using the comparison of polyol components in Table 1 that the polyurethane elastomer E2 shows a higher Shore A hardness than E1 at a similar wt % of aliphatic diacid (ie. adipic acid in E1 and C18 diacid in E2). Furthermore with an increased wt % of C18 diacid in the elastomer E2 compared to E3, the hardness and tensile strength go up in E2 compared to E3 but E2 still has a good amount of elongation.

[0240] By lowering the C18 diacid wt % in the elastomer E3 compared to E2 it can be seen that the elongation is improved in E3 over E2 and E3 still maintains a higher hardness and tensile strength than the comparative adipic acid containing elastomer E1.

[0241] After hydrolysis the C18 diacid containing elastomers E2 to E5 show an improved retention of elongation than adipic acid containing elastomer E1.

[0242] It is to be understood that the invention is not to be limited to the details of the above embodiments, which are described by way of example only. Many variations are possible.