Epoxy resin composition

Abstract

Curable composition obtained by combining and mixing an epoxy resin composition comprising an epoxy resin, a monool and/or polyol and a compound comprising a carboxamide group, and a polyisocyanate composition comprising a polyisocyanate, a lithium halide and a urea compound, wherein the number of moles of lithium halide per isocyanate equivalent ranges of from 0.0001-0.04 and the number of urea+biuret equivalents per isocyanate equivalent of from 0.0001-0.4. The epoxy resin composition is claimed as well.

Claims

1. A method for increasing pot-life of a curable composition comprising combining: a) a polyisocyanate composition comprising a polyisocyanate, a lithium halide and a urea compound having an average molecular weight of 500 to 15000 and comprising biuret groups; and b) an epoxy resin composition comprising an epoxy resin, a monool and/or a polyol and a compound having a structure NH.sub.2COR to form the curable composition wherein R is selected from hydrogen, a C.sub.1-C.sub.20 hydrocarbyl group, NH.sub.2, NR.sub.1R.sub.2, C.sub.6H.sub.5 and ##STR00002## where R.sub.1 and R.sub.2 are each independently OH or a C.sub.1-C.sub.10 hydrocarbyl optionally comprising 1-3 hydroxy and/or ether groups wherein the curable composition has a number of hydroxy equivalents per epoxy equivalent of 0.02 to 100, a number of carboxamide equivalents per epoxy equivalent of 0.0005 to 1, a number of urea and biuret equivalents per isocyanate equivalent ranging from 0.0001 to 0.4 and a number of epoxy equivalents per isocyanate equivalent ranging from 0.003 to 1.

2. The method of claim 1, wherein the urea compound is a compound obtained from a reaction of a diphenylmethane diisocyanate comprising at least 35% 4,4-diphenylmethane diisocyanate or a carbodiimide and/or a uretonimine variant of a diphenylmethane diisocyanate comprising at least 35% 4,4-diphenylmethane diisocyanate and an amine.

3. The method of claim 2, wherein the amine is a polyoxyalkylene monoamine comprising oxypropylene groups in an amount of at least 50% by weight, based on the total weight of the monoamine.

4. The method of claim 1, wherein the lithium halide is premixed with the urea compound to form a mixture and the mixture is added to the polyisocyanate.

5. The method of claim 1, wherein the curable composition has a pot-life at ambient conditions of at least 5 hours up to 300 hours.

6. The method of claim 1, wherein the curable composition has a pot-life at ambient conditions of at least 40 hours up to 300 hours.

7. A curable composition for making a polyisocyanurate material, the curable composition comprising: a polyisocyanate composition comprising a polyisocyanate, a urea compound having an average molecular weight of 500 to 15000 and comprising biuret groups and a lithium halide; and an epoxy resin composition comprising an epoxy resin, at least one of a monool and a polyol and a compound having a structure NH.sub.2COR wherein R is selected from hydrogen, a C.sub.1-C.sub.20 hydrocarbyl group, NH.sub.2, NR.sub.1R.sub.2, C.sub.6H.sub.5 and ##STR00003## where R.sub.1 and R.sub.2 are each independently OH or a C.sub.1-C.sub.10 hydrocarbyl optionally comprising 1-3 hydroxy and/or ether groups wherein the curable composition exhibits an increased pot-life as compared to a pot-life of the curable composition in the absence of the carboxamide compound.

8. The curable composition of claim 7, wherein: the urea compound does not comprise isocyanate-reactive groups other than urea groups; the urea compound has an average molecular weight of 200 Daltons to 3000 Daltons; the urea compound is a compound obtained by reacting a polyisocyanate selected from the group consisting of methylene diphenyl diisocyanate, a polyisocyanate comprising a methylene diphenyl diisocyanate, and a mixture thereof with a polyoxyalkylene monoamine comprising oxypropylene groups in an amount of at least 50% by weight calculated on the total weight of the monoamine; and a number of urea and biuret equivalents per isocyanate equivalent is in a range of from 0.001 to 0.2 and a number of urea and biuret equivalents per mole of lithium halide is in a range of from 0.5 to 60.

9. The curable composition of claim 7, wherein the polyisocyanate is selected from the group consisting of methylene diphenyl diisocyanate, a polyisocyanate composition comprising methylene diphenyl diisocyanate, and a mixture thereof.

10. The curable composition of claim 7, wherein the lithium halide is present in an amount ranging from 0.00015 to 0.025 moles per isocyanate equivalent.

11. The curable composition according to claim 7, wherein the lithium halide is lithium chloride.

12. The curable composition according to claim 7, wherein the epoxy resin is liquid at 20 C. to 25 C.

13. A curable composition for making a polyisocyanurate material, the curable composition comprising: a polyisocyanate composition comprising a polyisocyanate, a urea compound having an average molecular weight of 500 to 15000 and comprising biuret groups and a lithium halide; and an epoxy resin composition comprising an epoxy resin, at least one of a monool and a polyol and a compound having a structure NH.sub.2COR wherein R is selected from hydrogen, a C.sub.1-C.sub.20 hydrocarbyl group, NH.sub.2, NR.sub.1R.sub.2, C.sub.6H.sub.5 and ##STR00004## where R.sub.1 and R.sub.2 are each independently OH or a C.sub.1-C.sub.10 hydrocarbyl optionally comprising 1-3 hydroxy and/or ether groups wherein the curable composition exhibits a pot-life of at least 5 hours up to 300 hours.

14. The curable composition of claim 13, wherein: the urea compound does not comprise isocyanate-reactive groups other than urea groups; the urea compound has an average molecular weight of 200 Daltons to 3000 Daltons; the urea compound is a compound obtained by reacting a polyisocyanate selected from the group consisting of methylene diphenyl diisocyanate, a polyisocyanate comprising a methylene diphenyl diisocyanate, and a mixture thereof with a polyoxyalkylene monoamine comprising oxypropylene groups in an amount of at least 50% by weight calculated on the total weight of the monoamine; and a number of urea and biuret equivalents per isocyanate equivalent is in a range of from 0.001 to 0.2 and a number of urea and biuret equivalents per mole of lithium halide is in a range of from 0.5 to 60.

15. The curable composition of claim 13, wherein a number of carboxamide equivalents per epoxy equivalent of the epoxy resin composition is in a range of from 0.0005 to 1.

16. The curable composition of claim 15, wherein the number of carboxamide equivalents per epoxy equivalent of the epoxy resin composition is in a range of from 0.005 to 0.7.

17. The curable composition of claim 16, wherein the number of carboxamide equivalents per epoxy equivalent of the epoxy resin composition is in a range of from 0.01 to 0.5.

18. The curable composition of claim 13, wherein the carboxamide compound has a molecular weight of at most 499.

19. The curable composition of claim 13, wherein a number of hydroxyl equivalents per epoxy equivalent of the epoxy resin composition is in a range of from 0.02 to 100.

20. The curable composition of claim 13, wherein the curable composition exhibits a pot-life of at least 14 hours up to 300 hours.

Description

EXAMPLES

(1) Chemicals Used:

(2) Jeffamine M-600: a monofunctional polyoxyethylene polyoxypropylene primary amine having a molecular weight of about 560 and an oxypropylene/oxyethylene ratio of about 9/1. Obtainable from Huntsman. In these examples referred to as M-600.

(3) Suprasec 1306 polyisocyanate ex Huntsman: 4,4-MDI. In these examples referred to as S1306.

(4) Suprasec 2020 polyisocyanate: a uretonimine modified polyisocyanate ex Huntsman, in these examples indicated as 52020.

(5) Alcupol R1610 polyol ex Repsol indicated herein as R1610; a polyoxypropylene triol having an average molecular weight of about 1050.

(6) Daltocel F526 is a polyoxyethylene triol ex Huntsman; MW about 1300. Daltocel is a trademark of the Huntsman Corporation or an Affiliate thereof and has been registered in one or more but not all countries. Daltocel F442 and Daltocel F555 are also polyether polyols ex Huntsman having a nominal functionality of 3 and an average molecular weight of about 4000 and 6000, respectively.

(7) Voranol P400: polyol from DOW; a polyoxypropylene diol having an average molecular weight of about 430.

(8) Carbalink HPC: hydroxypropyl carbamate, a carboxamide compound ex Huntsman.

(9) Araldite DY-T epoxide ex Huntsman, triglycidylether of trimethylolpropane, indicated herein as DY-T. Araldite and Carbalink are trademarks of the Huntsman Corporation or an Affiliate thereof and has been registered in one or more but not all countries.

(10) In none of the following examples biuret formation was observed.

Example 1

(11) Preparation of Polyisocyanate Compositions Comprising Lithium Chloride and a Urea Compound.

(12) A number of moles of an amine, which was kept at 50 C., and a number of moles of a polyisocyanate 1, which was also kept at 50 C., were mixed and allowed to react for 1 hour, while stirring, so as to form a urea compound. The reaction temperature was kept at 80 C. An amount of salt was dissolved in an amount of ethanol while stirring.

(13) This solution was added to the above prepared urea compound which was still kept at 80 C. Stirring was continued for about 15 minutes. A substantial amount of ethanol was stripped off by distillation at 85-95 C. The amount of the urea/salt mixture so obtained is given in below Table 1; together with the amount and type of amine, polyisocyanate 1 and salt used and the amount of ethanol used.

(14) An amount of the so prepared urea/salt mixture (having a temperature of about 60 C.) was added to an amount of a polyisocyanate 2 and mixed so as to prepare the polyisocyanate composition for use with an epoxy resin composition.

(15) In below Table 2 the amounts and types of the ingredients used are given together with the ratio of the number of urea+biuret equivalents per isocyanate equivalent and the number of moles of salt per isocyanate equivalent and the number of urea+biuret equivalents per mole of salt. Parts by weight is indicated as pbw.

(16) TABLE-US-00002 TABLE 1 Urea + Polyiso- salt Urea Amine type/ cyanate 1 Salt type/ Ethanol/ mixture/ com- amount in type/amount amount amount amount pounds moles in moles in grams in grams in grams A M-600/2 S1306/1.04 LiCl/23.9 125.3 1407.6 B M600/2 S1306/1.04 LiCl/100.7 528.5 1484.4 C M-600/2 S1306/1.04 LiCl/48.6 255.0 1432.3 D M-600/2 S1306/1.04 LiCl/11.8 62.1 1396.0

(17) TABLE-US-00003 TABLE 2 Urea com- pound from Polyiso- urea + urea + Polyiso- table 1/ cyanate 2 biuret/ Salt/ biuret/ cyanate amount type/amount NCO NCO salt blends in pbw in pbw ratio ratio ratio 1 A/5 S2020/95 0.0109 0.003 3.65 2 B/1.25 S2020/95 0.0027 0.003 0.91 3 C/2.5 S2020/95 0.0055 0.003 1.82 4 A/2.5 S2020/95 0.0055 0.0015 3.65 5 A/15 S2020/95 0.0328 0.009 3.65 6 A/1.25 S2020/95 0.0027 0.0007 3.65 7 D/10 S2020/95 0.0219 0.003 7.30
Preparation of Epoxy Resin Compositions According to the Present Invention.

(18) The carboxamide compound was added to a polyol 1 and stirred under ambient pressure and at 120 C. for 1 hour. Then a polyol 2 was added if a second polyol was used. After cooling this mixture to ambient conditions, Araldite DY-T was added and stirred under ambient conditions. The amounts and types of ingredients used have been given in Table 3, wherein also the equivalent ratios of OH/epoxy and carboxamide/epoxy have been indicated.

(19) Preparation of Curable Compositions and Polyisocyanurate Materials According to the Present Invention.

(20) The compositions of Table 2 were mixed with epoxy compositions according to the invention (and comparative ones) for 30 seconds and placed at room temperature in order to determine the pot-life by following the temperature profile with a thermocouple placed in the liquid resin till the onset of the temperature rise. The curable composition was allowed to react so as to prepare polyurethane polyisocyanurate materials according to the present invention. The presence of isocyanurate groups was confirmed by Fourier Transformed InfraRed Spectroscopy (FTIRS).

(21) The ingredients used, the amounts in parts by weight, the number of epoxy equivalents per isocyanate equivalent and the pot-lives are given in Table 3.

(22) In the first column, A1 means that urea compound A (Table 1) was used and Polyisocyanate blend 1 (Table 2), and A6 means that urea compound A was used and polyisocyanate blend 6. For B2, 9 different experiments were conducted with urea compound B and Polyisocyanate blend 2.

(23) TABLE-US-00004 TABLE 3 Polyol Polyol Compositions Epoxy type/ type type Carboxamide Epoxy/ OH/ Curable from table 2/ amount in 1/amount 2/amount type/ NCO epoxy Carboxamide/ Pot-life compositions amount in pbw pbw in pbw in pbw amount in pbw ratio ratio epoxy ratio (h) A1-1* 1/100 DY-T/4 F526/2 P400/5 n.u. 0.048 0.87 0.000 5 A1-2 1/100 DY-T/4 F526/2 P400/5 urea/0.02 0.048 0.87 0.021 45 A1-3 1/100 DY-T/4 F526/2 P400/5 urea/0.04 0.048 0.87 0.042 91 A1-4 1/100 DY-T/4 F526/5 P400/5 urea/0.1 0.048 1.08 0.104 312 B2-1* 2/96.25 DY-T/4 F526/2 P400/5 n.u. 0.048 0.87 0.000 3 B2-2 2/96.25 DY-T/4 F526/2 P400/5 urea/0.02 0.048 0.87 0.021 5 B2-3 2/96.25 DY-T/4 F526/2 P400/5 urea/0.04 0.048 0.87 0.042 9 B2-4 2/96.25 DY-T/4 F526/5 P400/5 urea/0.10 0.048 1.08 0.104 89 B2-5* 2/96.25 DY-T/4 F442/5 P400/5 n.u. 0.048 0.84 0.000 5 B2-6 2/96.25 DY-T/4 F442/5 P400/5 N-methyl urea/0.010 0.048 0.84 0.004 6 B2-7 2/96.25 DY-T/4 F442/5 P400/5 N-methyl urea/0.020 0.048 0.84 0.008 7 B2-8 2/96.25 DY-T/4 F442/5 P400/5 N-methyl urea/0.050 0.048 0.84 0.021 14 B2-9 2/96.25 DY-T/4 F442/5 P400/5 N-methyl urea/0.10 0.048 0.84 0.042 35 C3-1 3/97.5 DY-T/4 F442/5 P400/5 1,1 diethyl urea/0.010 0.048 0.84 0.003 7 C3-2 3/97.5 DY-T/4 F442/5 P400/5 1,1 diethyl urea/0.020 0.048 0.84 0.005 9 C3-3 3/97.5 DY-T/4 F442/5 P400/5 1,1 diethyl urea/0.050 0.048 0.84 0.013 14 C3-4 3/97.5 DY-T/4 F442/5 P400/5 1,1 diethyl urea/0.10 0.048 0.84 0.027 24 A1-5 1/100 DY-T/4 F526/5 R1610/10 Propionamide/0.05 0.048 1.24 0.021 90 A1-6 1/100 DY-T/4 F526/5 R1610/10 Propionamide/0.13 0.048 1.24 0.053 130 A1-7 1/100 DY-T/4 F526/5 R1610/10 Propionamide/0.25 0.048 1.24 0.107 180 A4-1 4/97.5 DY-T/4 F526/5 R1610/10 Propionamide/0.25 0.048 1.24 0.107 >138 A1-8 1/100 DY-T/4 F555/5 n.u. Tolyl urea/0.010 0.048 0.08 0.002 12 A1-9 1/100 DY-T/4 F555/5 n.u. Tolyl urea/0.05 0.048 0.08 0.010 41 A1-10 1/100 DY-T/4 R1610/15 n.u. Carbalink HPC/0.13 0.048 1.34 0.034 30 A4-2 4/97.5 DY-T/4 R1610/15 n.u. Carbalink HPC/0.13 0.048 1.34 0.034 55 A1-11 1/100 DY-T/4 F526/0.25 R1610/5 Urea/0.0063 0.048 0.46 0.007 25 A1-12 1/100 DY-T/8 F526/2.5 R1610/5 Urea/0.063 0.096 0.31 0.033 97 A1-13 1/100 DY-T/12 F526/2.5 R1610/5 Urea/0.063 0.014 0.21 0.022 40 A5-1 5/110 DY-T/4 F526/2.5 R1610/10 Urea/0.063 0.048 1.07 0.065 150 A4-3 4/97.5 DY-T/4 R1610/15 n.u. Carbalink HPC/0.033 0.048 1.34 0.009 14 A1-15 1/100 DY-T/1.5 F526/1.5 n.u. Urea/0.015 0.018 0.28 0.042 >65 D7-1 7/105 DY-T/4 F526/1 P400/5 Urea/0.010 0.048 0.79 0.010 >65 n.u. means not used *comparative example

Further Examples According to the Invention

(24) In Table 4 the information related to a few further experiments has been given, similar to Table 3 with the exception that the T.sub.g of the polyisocyanurate has been given instead of the pot-life of the curable composition. The T.sub.g was measured by Differential Mechanical Thermo Analysis on samples having a thickness of about 4 mm which had been cured in an open mould for 1 hour at 125 C. in an oven. With further post curing the T.sub.g could be higher.

(25) TABLE-US-00005 TABLE 4 Compositions from table 2/ Epoxy type/ Epoxy/ OH/ Curable amount in amount in Polyol type 1/ Polyol type 2/ Carboxamide type/ NCO epoxy Carboxamide/ Tg (tan ) compositions pbw pbw amount in pbw amount in pbw amount in pbw ratio ratio epoxy ratio in C. A4-4 4/97.5 DY-T/4 F526/2.5 R1610/12.5 urea/0.13 0.048 1.29 0.130 183.9 A1-14 1/100 DY-T/4 F526/2.5 R1610/12.5 urea/0.063 0.048 1.29 0.065 192.0 A6-1 6/96.25 DY-T/4 F526/2.5 R1610/12.5 urea/0.13 0.048 1.29 0.130 186.8 A1-7 1/100 DY-T/4 F526/5 R1610/10 Propionamide/0.25 0.048 1.24 0.107 213.1.sup.(1) A1-10 1/100 DY-T/4 R1610/15 n.u. Carbalink HPC/0.13 0.048 1.34 0.034 221.7.sup.(1) A1-5 1/100 DY-T/4 F526/5 R1610/10 Propionamide/0.050 0.048 1.24 0.021 239.6 B2-10 2/96.25 DY-T/4 F526/5 P400/5 N-methyl urea/0.25 0.048 1.08 0.105 183.4 A1-16 1/100 DY-T/4 F526/1 R1610/14 1,1 diethyl urea/0.025 0.048 1.32 0.007 194.3 A1-17 1/100 DY-T/8 F526/1.5 R1610/13.5 Urea/0.038 0.096 0.65 0.020 197.8 .sup.(1)cured for 1 h at 150 C. n.u. means not used