Process for producing a ring-opening polymerization product

Abstract

The invention relates to a process for producing a ring-opening polymerization product by reacting at least one polyisocyanate and 2-oxo-1,3-dioxolane-4-carboxylic acid and subjecting the reaction product to a temperature within the range of from about 40 to about 150 C. in the presence of a catalytic amount of at least one non-nucleophilic base. The obtained polymerization product may be present as a foam and is suitable as binder, insulation material, sealant or coating and in the production of mattresses or wound pads.

Claims

1. A process for producing a ring-opening polymerization product in the form of an open-cell foam which comprises the steps of: a) providing a reaction product of at least one polyisocyanate and 2-oxo-1,3-dioxolane-4-carboxylic acid; and b) subjecting said reaction product to a temperature within the range of from 40 to 150 C. in the presence of a catalytic amount of at least one non-nucleophilic base, wherein carbon dioxide is cleaved off.

2. The process of claim 1, wherein the polyisocyanate is selected from an aliphatic isocyanate, an aromatic isocyanate, a cycloaliphatic isocyanate, or a combination thereof, having an NCO functionality of 2.

3. The process of claim 1, wherein the polyisocyanate is selected from toluylenediisocyanate, isophorondiisocyanate, diphenylmethanediisocyanate, 4,4-diisocyanato-dicyclohexylmethane, tetramethylenediisocyanate, pentamethylenediisocyanate, hexamethylene-diisocyanate, and mixtures thereof.

4. The process of claim 1, wherein the polyisocyanate is a polyisocyanate prepolymer which is obtained by reacting a molar excess of a polyisocyanate with a polyol, wherein the polyisocyanate: i.) is selected from an aliphatic isocyanate, an aromatic isocyanate, a cycloaliphatic isocyanate, or a combination thereof, having an NCO functionality of 2; or ii.) is selected from toluylenediisocyanate, isophorondiisocyanate, diphenylmethanediisocyanate, 4,4-diisoyanatodicyclohexylmethane, tetramethylene diisocyanate, pentamethylenediisocyanate, hexamethylenediisocyanate, and mixtures thereof.

5. The process of claim 4, wherein the polyol has an average OH functionality of 2 to 8.

6. The process of claim 5, wherein the polyol is a poly-C.sub.2-4-alkylenoxide having a number average molecular weight Mn in the range of from 400 to 10000.

7. The process of claim 1, wherein the reaction product of step (a) is obtained by: (1) reacting the polyisocyanate with an equimolar amount of 2-oxo-1,3-dioxolane-4-carboxylic acid; or by (2) reacting in a first step a molar excess of the polyisocyanate with 2-oxo-1,3-dioxolane-4-carboxylic acid to obtain an intermediate, and in a second step reacting the intermediate with a polyol, wherein the polyol has an average OH functionality of 2 to 8.

8. The process of claim 7, wherein the polyol is a poly-C.sub.2-4-alkylenoxide having a number average molecular weight Mn in the range of from 400 to 10000.

9. The process of claim 1, wherein the reaction product of step (a) is of formula (I) ##STR00005## wherein R is an x-valent radical derived from said polyisocyanate by formally removing the NCO groups and x is an integer from 2 to 6.

10. The process of claim 1, wherein step (b) is carried out at a temperature in the range of from 60 to 150 C.

11. The process of claim 1, wherein the non-nucleophilic base is selected from 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazobicyclo[4.3.0]non-5-ene, 1,4-diazabicyclo[2.2.2]octane, 2,6-di-tert-butylpyridine, diisopropylethylamine, tetramethylguanidine or mixtures thereof.

12. A process for producing a ring-opening polymerization product in the form of an open-cell foam which comprises the steps of: a) providing a reaction product of at least one polyisocyanate and 2-oxo-1,3-dioxolane-4-carboxylic acid; and b) subjecting said reaction product to a temperature within the range of from 40 to 150 C. in the presence of a catalytic amount of at least one non-nucleophilic base, wherein carbon dioxide is cleaved off; wherein the reaction product of step (a) is obtained by: (1) reacting the polyisocyanate with an equimolar amount of 2-oxo-1,3-dioxolane-4-carboxylic acid; or by (2) reacting in a first step a molar excess of the polyisocyanate with 2-oxo-1,3-dioxolane-4-carboxylic acid to obtain an intermediate, and in a second step reacting the intermediate with a polyol; and wherein the polyol has an average OH functionality of 2 to 8; wherein the polyol is a poly-C.sub.2-4-alkylenoxide having a number average molecular weight Mn in the range of from 400 to 10000.

13. A ring-opening polymerization product in the form of an open-cell foam obtained by the process of claim 1.

14. The product of claim 13, wherein the polyisocyanate: i.) is selected from an aliphatic isocyanate, an aromatic isocyanate, a cycloaliphatic isocyanate, or a combination thereof, having an NCO functionality of 2; or ii.) is selected from toluylenediisocyanate, isophorondiisocyanate, diphenylmethanediisocyanate, 4,4-diisocyanatodicyclohexylmethane, tetramethylene diisocyanate, pentamethylenediisocyanate, hexamethylenediisocyanate and mixtures thereof.

15. The product of claim 13, wherein the non-nucleophilic base is selected from 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazobicyclo[4.3.0]-non-5-ene, 1,4-diaza bicyclo[2.2.2]octane, 2,6-di-tert-butylpyridine, diisopropylethylamine, tetramethyl guanidine or mixtures thereof.

Description

(1) FIG. 1 shows a thermogravimetric scan of a product according to the invention.

EXAMPLES

(2) The following abbreviations and products are used in the examples:

(3) CYCA: 2-oxo-1,3-dioxolane-4-carboxylic acid

(4) IPDI: isophorondiisocyanate

(5) DBTL: dibutyl tin dilaurate

(6) DMAP: 4-dimethylaminopyridine

(7) THF: tetrahydrofuran

(8) RT: room temperature

(9) Lupranol 2032: commercial product of BASF SE; trifunctional polyetherpolyol with

(10) OH number of 55 mg KOH/g and M.sub.n=3060 g/mole

(11) Lupranol 2095: commercial product of BASF SE; trifunctional polyetherpolyol with

(12) OH number of 35 mg KOH/g and M.sub.n=4800 g/mole

(13) DBU: 1,8-diazabicyclo[5.4.0]undec-7-ene

(14) TGA: thermogravimetric analysis

(15) TDI: toluylene-2,4-diisocyanate

(16) HDI: hexamethylene-1,6-diisocyanate

(17) Arcol Polyol 1374: commercial product of Bayer; trifunctional polyetherpolyol with

(18) OH number of 25-29 mg KOH/g and M.sub.eq=2078 g/mole

(19) Desmodur N3600: commercial product of Bayer; polyfunctional aliphatic polyisocyanate, i.e. HDI trimer; NCO content 23.50.5%

Example 1

Preparation of 4-methoxycarbonyl-2-oxo-1,3-dioxolane (Reference)

(20) ##STR00003##

(21) 80 g of sodium carbonate were dissolved in 200 ml of distilled water in a 1000 ml three-neck flask. The solution was cooled to 10 C. 58.5 g of methyl acrylate were then added and, after ca. 10 minutes, likewise at 10 C., 400 ml of a 7% strength aqueous sodium hypochlorite solution were stirred in. Then, the system was immediately flushed intensively with CO.sub.2. The temperature was allowed to increase to room temperature. The flask was flushed intensively with CO.sub.2 for a further 1 h at about 25 to 30 C., during which the temperature was held in the stated range by means of occasional cooling with an ice bath. The resulting white solid was filtered off via a suction filter. The filtrate was extracted with 490 ml of dichloromethane. The combined organic phase was dried with sodium sulfate and filtered off. The filtrate was removed on a rotary evaporator. Methyl epoxypropionate was obtained in 50 to 60% yield and a purity of 97%.

(22) 20 g of the methyl epoxypropionate were mixed with 20 g of tert.-butyl methyl ether and 1 g of tetrabutylammonium bromide. The homogeneous mixture was transferred to a 100 ml pressurized reactor and carboxylated for 4 days at 40 C. and a CO.sub.2 pressure of 20 bar. After the carboxylation, a two-phase system was obtained; the upper phase consisted of tert-butyl methyl ether, and the lower phase consisted of 4-methoxycarbonyl-2-oxo-1,3-dioxolane (purity 94% (GC), yield 94%).

Example 2

Aerobic Oxidation of Glycerol Carbonate (Reference)

(23) ##STR00004##

(24) 11.81 g (0.1 mole) of glycerol carbonate (4-(hydroxymethyl)-2-oxo-1,3-dioxolane), 0.50 g (0.002 mole) of manganese (II) nitrate tetrahydrate (Mn(NO.sub.3).sub.2.4 H.sub.2O), 0.58 g (0.002 mole) of cobalt (II) nitrate hexahydrate (Co(NO.sub.3).sub.2. 6 H.sub.2O) and 1.88 g (0.012 mole) of TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl) were dissolved in 100 ml of acetic acid. The reddish solution was stirred for 72 hours at room temperature under an oxygen atmosphere, evaporated to dryness, and the crude product was purified by recrystallization. This gave 2-oxo-1,3-dioxolane-4-carboxylic acid in the form of white to yellowish crystal needles. The yield was about 75%, and the analytical data were in agreement with known data.

(25) Additional examples for preparing the compounds of examples 1 and 2 are given in WO 2014/118268.

Example 3

CYCA-I 2032, a Binder System Based on CYCA, IPDI and Lupranol 2032 can be Cured in the Presence of 3 wt.-% of DBU to Give a Yellowish Foam within 1 h at 100 C.

(26) 3.1 Preparation of Prepolymer CYCA-I 2032

(27) Under an atmosphere of N.sub.2, 91.80 g Lupranol 2032 (0.03 mole), 20.01 g IPDI (0.09 mole) and 0.022 g DBTL in 250 mL of dry THF were heated to 60 C. and stirred for 1.25 h until the desired NCO value of 3.0% was reached. The reaction mixture was allowed to cool to RT and 10.70 g CYCA (according to the final NCO value of 3.0%) and 0.10 g DMAP were added and the reaction mixture was stirred for 12 h until no residual NCO could be found anymore (IR control). The solvent was removed in vacuo and the binder was obtained as highly viscous yellowish oil in quantitative yield.

(28) 3.2 1 K-Curing of CYCA-I 2032

(29) 12.0 g CYCA-I 2032 and 0.36 g (3 wt.-%) DBU were vigorously mixed in a plastic beaker and heated to 100 C. in a drier for 1 h. A yellowish soft foam was obtained. The foam was insoluble in most common organic solvents such as THF, dimethylsulfoxide, acetone, toluene and water. In some cases swelling was observed.

(30) IR (v, cm-1): 3312 (bm), 2969 (m), 2928 (m), 2866 (m), 1714 (w), 1648 (m), 1603 (w), 1532 (w), 1453 (m), 1372 (m), 1343 (w), 1324 (w), 1303 (w), 1241 (w), 1094 (s), 1014 (w), 925 (m), 868 (w), 766 (w).

(31) The stability of the foam was examined via TGA under N.sub.2 (FIG. 1). Decomposition starts at approx. 150 C. and strongly increases at 350 C.

Example 4

CYCA-T 2095, a Binder System Based on CYCA, TDI and Lupranol 2095 can be Cured at Slightly Elevated Temperature in the Presence of 1 wt.-% of DBU to Give a Yellowish Elastic Foam within 1 h

(32) 4.1 Preparation of Prepolymer CYCA-T 2095

(33) Under an atmosphere of N.sub.2, 584.76 g Lupranol 2095 (0.36 mole OH), 100.0 g of TDI-CYCA intermediate (15.35% NCO, 0.36 mole NCO; obtained in analogy to example 11 or 12 of WO 2014/118268) and 0.09 g DBTL were mixed in a flask, heated to 60 C. and stirred until no residual NCO was found (approx. 6 h, IR control). The reaction mixture was cooled to RT and the binder was obtained as viscous yellowish oil in quantitative yield.

(34) 4.2 Curing of CYCA-T 2095

(35) 12.0 g CYCA-T 2095 and 0.12 g (1 wt.-%) DBU were mixed in a plastic beaker and allowed to cure at 80 C. for 1 h. A yellowish, stable elastic foam was obtained.

Example 5

CYCA-T 1374, a Binder System Based on CYCA, TDI and Arcol Polyol 1374 can be Cured at Slightly Elevated Temperature in the Presence of 3 wt.-% of DBU to Give a Yellowish Elastic Film

(36) 5.1 Preparation of CYCA-T 1374

(37) Under an atmosphere of N.sub.2, 211.38 g Arcol Polyol 1374 (0.10 mole OH) were dissolved in 750 mL of dry THF. 27.98 g of TDI-CYCA intermediate (15.27% NCO, 0.10 mole NCO; obtained in analogy to example 11 or 12 of WO 2014/118268) and 0.06 g DBTL were added. The reaction mixture was heated to 60 C. until no residual NCO was found (approx. 6 h, IR control). The reaction mixture was cooled to RT and the solvent was removed in vacuo. The pure binder was obtained as highly viscous yellowish oil in quantitative yield.

(38) 5.2 Curing of CYCA-T 1374

(39) 12.0 g CYCA-T 1374 and 0.36 g (3 wt.-%) DBU were mixed in a plastic beaker and allowed to cure at 40 C. for 1 h. A yellowish, stable elastic film was obtained.

(40) IR (v, cm-1): 3267 (vw), 2968 (m), 2866 (m), 1703 (w), 1648 (w), 1615 (w), 1534 (w), 1453 (m), 1373 (m), 1344 (w), 1296 (w), 1241 (w), 1093 (s), 926 (m), 870 (w), 832 (w), 769 (w).

Example 6

CYCA-H 9046 (TRICYCA), a Binder System Based on CYCA and Desmodur N 3600 (HDI-isocyanurate) can be Cured in the Ppresence of 1 wt.-% DBU

(41) 6.1 Preparation of CYCA-H 9046 (TRICYCA)

(42) Under an atmosphere of N.sub.2, 78.21 g Desmodur N 3600 (0.43 mol NCO), 57.28 g cyclic carbonate carboxylic acid (CYCA) (0.43 mole) and 0.52 g 4-DMAP were diluted with 400 mL of dry THF and the reaction mixture was stirred at RT until no residual NCO was found (approx. 6h, IR control). The solvent was removed in vacuo and the pure binder was obtained as yellowish viscous liquid in quantitative yield.

(43) 6.2 Curing of CYCA-H 9046 (TRICYCA)

(44) 12.0 g CYCA-H 9046 and 0.12 g (1 wt.-%) DBU were mixed in a plastic beaker and allowed to cure at 80 C. for 1 h. A brownish, hard and brittle, porous material was obtained.

Example 7

N3600-GC, a Binder System Based on Glycerol Carbonate and Desmodur N3600 (HDI-isocyanurate) (Comparative Example to Example 6)

(45) 7.1 Preparation of N3600-GC

(46) Under an atmosphere of N2, 320.39 g Desmodur N 3600 (1.72 mole NCO), 202.78 g glycerol carbonate (1.72 mole) and 0.1 g DBTL were diluted with 600 mL of dry THF and the reaction mixture was heated to 60 C. until no residual NCO was found (approx. 6 h, IR control). The reaction mixture was cooled to RT and the solvent was removed in vacuo. The pure binder was obtained as clear viscous liquid in quantitative yield.

(47) 7.2 Curing of N3600-GC

(48) 12.0 g N3600-GC and 0.12 g (1 wt.-%) DBU were mixed in a plastic beaker and allowed to react at 80 C. for 1 h. No curing and no foaming was observed and a clear viscous liquid was obtained.

(49) In contrast to the examples of the invention, the cyclic carbonate of this binder is not activated by an electron-withdrawing group. In this case, no curing and foaming reaction was observed.

Example 8

T-2095-GC, a Binder System Based on Glycerol Carbonate, TDI and Lupranol 2095 (Comparative Example to Example 4)

(50) 8.1 Preparation of T-2095-GC

(51) Under an atmosphere of N.sub.2, 211.2 g Lupranol 2095 (M.sub.eq=1600 g/mol, 0.13 mol OH) were diluted with 350 mL of dry THF, 23.00 g TDI (48.2% NCO, 0.13 mole) were added and the reaction mixture was heated to 50 C. for 20 min. The NCO content was determined and the corresponding amount of glycerol carbonate (16.92 g, 0.14 mole) was added as well as 0.04 g (0.02 wt.-%) of DBTL. The reaction mixture was stirred at RT for 8 h and after removal of the solvent the binder was obtained as viscous clear oil in quantitative yield.

(52) 8.2 Curing of T-2095-GC

(53) 12.0 g T-2095-GC and 0.12 g (1 wt.-%) DBU were mixed in a plastic beaker and allowed to react at 80 C. for 3d. No curing and foaming was observed and a turbid brownish liquid was obtained.