Cyclic carbonates

Abstract

Compounds of the formula ##STR00001##
in which R.sup.1 is an organic radical having a (meth)acryloyl group and R.sup.2, R.sup.3, and R.sup.4 independently of one another are an H atom or a C1 to C10 alkyl group.

Claims

1. A compound of formula (I) ##STR00025## in which R.sup.1 is an organic radical having a (meth)acryloyl group and R.sup.2, R.sup.3, and R.sup.4 independently of one another are an H atom or a C1 to C10 alkyl group.

2. The compound according to claim 1, wherein R.sup.1 is an organic radical having a total of not more than 24 C atoms and comprising no heteroatoms other than oxygen atoms.

3. The compound according to claim 1, wherein R.sup.1 is a group of formula (II) ##STR00026## in which X is a bond or an alkylene group having 1 to 18 C atoms and R.sup.5 is an H atom or a methyl group, or R.sup.1 is a group of formula (III) ##STR00027## in which m and p independently of one another are 0 or an integer from 1 to 10, R.sup.5 is an H atom or a methyl group, and R.sup.6 is an H atom or a C1 to C10 alkyl group, or R.sup.1 is a group of formula (IV) ##STR00028## in which s and t independently of one another are 0 or an integer from 1 to 10, R.sup.5 is an H atom or a methyl group, and R.sup.7 is an H atom or a C1 to C10 alkyl group.

4. The compound according to claim 1, wherein R.sup.2 is a methyl group and R.sup.3 and R.sup.4 are an H atom.

5. A process for preparing the compound of claim 3, in which R.sup.1 is a group of the formula (II), comprising: reacting, in a first stage, a compound having a terminal triple bond with a hydroxyalkanone or hydroxyalkanal, the triple bond undergoing addition to the carbonyl group of the hydroxyalkanone or hydroxyalkanal to form a dihydroxy compound, protecting, in a second stage, the hydroxyl group of the dihydroxy compound that did not originate from the carbonyl group with a protecting group, ring closing, in a third stage, to form a carbonate group with carbon dioxide, and replacing, in a fourth stage, the protecting group with a (meth)acryloyl group.

6. A process for preparing the compound of claim 3, in which R.sup.1 is a group of the formula (III), comprising: reacting, in a first stage, a compound having a terminal triple bond with an alkanone or alkanal which comprises an acetal group, the triple bond undergoing addition to the carbonyl group of the alkanone or alkanal to form a hydroxy compound, ring closing, in a second stage, to form a carbonate group with carbon dioxide, ring closing, in a third stage, to form a 1,3-dioxane ring by reaction of the acetal group with a compound having a total of at least three hydroxyl groups, with two of the hydroxyl groups being located in 1,3 position, and introducing, in a fourth stage, the (meth)acryloyl group by esterification or transesterification of the remaining hydroxyl group.

7. A process for preparing the compound of claim 3, in which R.sup.1 is a group of the formula (IV), comprising: reacting, in a first stage, a compound having a terminal triple bond with an alkanone or alkanal which comprises an acetal group, the triple bond undergoing addition to the carbonyl group of the alkanone or alkanal to form a hydroxy compound, ring closing, in a second stage, to form a carbonate group with carbon dioxide, ring closing, in a third stage, to form a 1,3-dioxolane ring by reaction of the acetal group with a compound having a total of at least three hydroxyl groups, with two of the hydroxyl groups being located in 1,2 position, and introducing, in a fourth stage, the (meth)acryloyl group by esterification or transesterification of the remaining hydroxyl group.

8. An epoxy resin composition comprising the compound of claim 1.

9. An epoxy resin composition comprising a) a compound of claim 1, b) an epoxy compound having at least one epoxy group c) optionally a hardener for the epoxy compound, and d) optionally a further constituent.

10. The epoxy resin composition according to claim 9, comprising 0.1 to 10 000 parts by weight of the compound of the formula (I) per 100 parts by weight of the epoxy compound.

11. The epoxy resin composition according to claim 9, wherein the hardener is present, and has at least one primary or secondary amino group.

12. A two-component binder system comprising: a component A comprising a) the compound of claim 1, b) an epoxy compound having at least one epoxy group, and a component B comprising c) a hardener for the epoxy compound.

13. A coating material, casting material, or adhesive comprising the epoxy resin composition of claim 9.

Description

EXAMPLES

1. Materials

(1) ExoVC Acrylate 1:

(2) ##STR00018##

(3) ExoVC Acrylate 2:

(4) ##STR00019##

(5) ExoVC, Comparative

(6) ##STR00020##

4,4-Dimethyl-5-methylene-1,3-dioxolan-2-one (ExoVC for Short) According to WO2011/157671

(7) Epoxy Resin:

(8) Aromatic epoxy resin based on bisphenol A with an epoxide equivalent of 175-185 g/eq and with a viscosity at 25 C. of 8-10 Pa.Math.s (Epilox A 18-00)

(9) Hardeners

(10) Hardener H1: Polyetheramine D230 (BASF SE)

(11) Hardener H2: Isophoronediamine (IPDA, BASF SE)

2. Preparation Examples

(12) 2.1. Preparation of ExoVC Acrylate 1

(13) The preparation takes place in four stages.

(14) The reaction scheme below encompasses stages 1 to 3

(15) ##STR00021##

(16) 1st Stage: Reaction of Hydroxypentanone with Acetylene to Give the Acetylene Adduct:

(17) KOtBu (800 g, 7.1 mol) is introduced in anhydrous THF (4.5 L) and cooled to 0-3 C. Acetylene (280 g, 10.8 mol) is introduced at this temperature over the course of 3 hours. Then, with further introduction of acetylene (130 g, 5 mol), hydroxypentanone (550 g, 5.39 mol) is added dropwise at 0-6 C. over the course of 1 hour. After passage through a viscosity maximum, an orange-brown solution is formed here.

(18) After 1 hour of subsequent stirring at 0-3 C., the system is warmed to RT and, at 20-25 C., ammonium chloride (1068 g in 5 L of water) is added over the course of 45 minutes. Two phases are formed.

(19) The organic phase is separated off, dried over sodium sulfate, and stripped of its solvent on a rotary evaporator at 40 C. and 5 mbar.

(20) 649 g of a brown oil are obtained. This oil is distilled under an oil pump vacuum, observing a liquid-phase temperature of not more than 130 C. The principal fraction was obtained at 110-111 C. in the form of a yellow oil (440 g, 3.4 mol, 64%).

(21) Purity (GC area %): 93%

(22) 2nd Stage: Reaction of the Diol with Formic Acid to Give the Formate:

(23) The diol obtained in the first stage (1.305 kg, 10.2 mol) is introduced and is admixed with formic acid (1.512 L, 40 mol) at 7-8 C. over the course of 1 hour. The system is then warmed to room temperature and the progress of the reaction is observed by GC/FID. The reaction is allowed to continue until there is virtually no longer any increase in the principal peak, this being the case after about 4 hours at RT. If the reaction is continued beyond this point, there is increased formation of doubly formylated product.

(24) For working up, the reaction mixture is first concentrated under reduced pressure, without heating, and the crude product obtained is then distilled at 12 mbar. The principal fraction goes over at 112-115 C. in the form of a clear yellow liquid (1.453 kg, 9.3 mol, 91%). Purity (GC area %): 93%

(25) 3rd Stage: Ring Closure with CO.sub.2 to Give the ExoVC Formate

(26) The formate obtained in the second stage (1.623 kg, 10.4 mol) is admixed with silver acetate (1.38 g) and TMTACN (N,N,N-trimethyl-1,4,7-triazacyclononane, 13.8 mL) and subjected to 10 bar of CO.sub.2 in a stirred autoclave with a pressure maintenance valve.

(27) Over the course of 5 hours, the temperature rises to 56 C. and the pressure to 18 bar. When the temperature has dropped back to RT, the mixture is heated to 70 C. The pressure at this stage rises to about 28 bar. After about 4 hours, reaction monitoring shows virtually no remaining reactant (GC/FID).

(28) The system is cooled and let down. The contents of the autoclave are admixed with dichloromethane (1.5 L) and then washed twice with HCl (10% strength solution, 480 mL each time) and dried over sodium sulfate, and the solvent is removed on a rotary evaporator (40 C., 60 mbar).

(29) Thereafter, with stirring at RT, all of the constituents volatile under an oil pump vacuum are removed, a procedure which may take up to 48 hours. About 1.9 kg of crude product are obtained.

(30) For further purification, volatile components are first separated off in a thin-film evaporator with wiper system (0.05-0.02 mbar, jacket temperature 109-114 C.). At least two runs are usually required for this purpose.

(31) Then, in a further run, the target compound is separated off from low-volatility constituents (0.012 mbar, jacket temperature 170 C.).

(32) Yield of ExoVC formate: 1.419 kg (7.1 mol, 68%).

(33) Purity (GC area %): 97%

(34) 4th Stage: Acrylation to Give the ExoVC Acrylate 1

(35) ##STR00022##

(36) A two-liter flat-bottom flask with Teflon stirrer, thermometer and condenser was charged with 300 g of ExoVC formate (1.5 mol) and 1200 g of methyl acrylate (14 mol). The methyl acrylate contained 0.3 g of MeHQ (monomethyl ether of hydroquinone) as inhibitor. The mixture was stirred and heated to 40 C. 30 g of the enzyme Candida Antarctica lipase B (immobilized form) were added.

(37) After 24 hours, the resulting mixture was decanted into a two-liter round-bottom flask, with the enzyme remaining in the flat-bottom flask. The methanol formed and, simultaneously, methyl acrylate were removed under reduced pressure.

(38) The residue was returned, together with 1000 g of fresh methyl acrylate, to the flat-bottom flask containing the enzyme. The mixture obtained was stirred again at 40 C. for 24 hours.

(39) The reaction mixture was cooled to room temperature and filtered. Methanol and unreacted methyl acrylate were removed by distillation under reduced pressure.

(40) The yield was 339 g of ExoVC acrylate 1

(41) Purity: 96.7% (determined by gas chromatography)

(42) 2.2 Preparation of ExoVC Acrylate 2

(43) The preparation takes place in four stages.

(44) The reaction scheme below encompasses stages 1 to 3

(45) ##STR00023##

1.) Ethynylation of 4,4-dimethoxybutan-2-one

(46) TMS-acetylene (982 g, 10 mol) is initially charged under argon in THF (17 L, dried over molecular sieve) and cooled to 68 C. With stirring, over the course of 1 h, n-butyllithium (2.5 M in hexane, 4 L) is added dropwise at 68 C., followed by stirring for a further hour.

(47) Over the course of 30 minutes, the ketone (1.319 kg, 10 mol) is then added dropwise at 68 C. to 54 C., followed by stirring for 15 minutes. After that, the mixture is heated to 9 C. and water (2.9 L) is added in one portion. The temperature here rises to about 17 C.

(48) The reaction mixture is concentrated thoroughly at 45 C./8 torr. GC analysis ensures that there is no longer any TMS-protected product present.

(49) The residue is suspended in diethyl ether (750 mL) and filtered, and the filtration residue is washed again with diethyl ether. The filtrate is concentrated under reduced pressure. This leaves about 1.2 kg of crude material as a brown liquid.

(50) By vacuum distillation (5 mbar), about 1.1 kg (7 mol, 70%) of ethynylated product are obtained from the brown liquid at 64-68 C., in the form of a colorless oil.

(51) Purity: >96% (GC area %)

2.) Ring Closure with CO2

(52) The acetylene alcohol (1233 g; 7.79 mol) obtained in stage 1 is introduced in acetonitrile (1.2 L) and admixed in a stirred autoclave with PMDETA (pentamethyldiethylenetriamine; 138.9 g; 0.8 mol) and AgOAc (12.9 g; 0.078 mol). 50 bar of CO.sub.2 are injected and the mixture is stirred for 2.5 hours. The temperature rises to 75 C.

(53) After cooling to room temperature, the reaction mixture is let down to atmospheric pressure, filtered, and concentrated at 100 C./5 mbar. About 1.5 g of crude material remain, in the form of a brown liquid.

(54) By vacuum distillation at 5 mbar, about 1.39 kg of the carbonate are obtained as an orange-colored oil from the brown liquid, at 114-115 C., and this oil crystallizes to completion overnight (possibly after addition of a few seed crystals).

(55) The crystal mass is stirred with cyclohexane (1.34 L), and filtered with suction, and the residue is washed again with cyclohexane (0.45 L).

(56) Drying under reduced pressure gives 1.29 kg (6.38 mol, 64%) of almost colorless solid.

(57) Purity: >99% (GC area %)

3.) Transacetalization with Trimethylolpropane

(58) The dimethoxy-substituted carbonate from stage 2 (250 g, 1.24 mol) is introduced in 1.4 L acetonitrile under an argon atmosphere. Then 253 g (1.87 mol) of trimethylolpropane and 407 mg (0.002 mol) of p-toluenesulfonic acid hydrate are added. The mixture is heated under reflux for 10 hours.

(59) After cooling to room temperature, the solvent is removed under reduced pressure and the residue is taken up in about 1 L of MTBE. It is washed with four times 300 mL of water. The organic phase is dried over sodium sulfate, filtered, and concentrated on a rotary evaporator. This is followed by drying at 40 C. under an oil pump vacuum for several hours.

(60) The product is obtained as a viscose, slightly yellowish oil (339 g) in the form of two isomers, this oil slowly crystallizing on prolonged standing at room temperature.

(61) Purity: >98% (GC area %)

4.) Acrylation to Give ExoVC Acrylate 2

(62) ##STR00024##

(63) In a two-liter flat-bottom flask with Teflon stirrer, thermometer, and condenser, 129 g of ExoVC-PMP alcohol (0.47 mol), 409 g of methyl acrylate (4.75 mol), and 152 g of molecular sieve 5 powder were introduced. The methyl acrylate contained 0.3 g of MeHQ (monomethyl ether of hydroquinone) as inhibitor. The mixture was stirred and heated to 60 C. 9.7 g of the enzyme Candida Antarctica lipase B (immobilized form) were added.

(64) After 72 hours, 100 g of molecular sieve 5 powder and 9.7 g of the enzyme Candida Antarctica lipase B (immobilized form) were added.

(65) After 96 hours, the reaction mixture was cooled to room temperature and filtered. Methanol and unreacted methyl acrylate were removed by distillation under reduced pressure.

(66) The yield was 153 g of ExoVC acrylate 2.

(67) Purity: 97.1% (determined by gas chromatography)

3. Performance Tests

(68) The epoxy resin compositions were prepared by mixing the epoxy resins, the hardeners, and the reactive diluents (ExoVC acrylate 1, ExoVC acrylate 2 or ExoVC). The tables give the details of the epoxy resins, hardeners and reactive diluents used and also of their parts by weight.

(69) 3.1 Viscosity and Reactivity

(70) The initial viscosity of the epoxy resin compositions was determined at 25 C. using a plate/plate viscometer having a slot width of 1 mm (MCR302, Anton Paar).

(71) Using the same instrument, the increase in the viscosity of the compositions was measured over time (temperature 25 C.). The tables report the time taken for the initial viscosity to double. The shorter the time, the higher the reactivity.

(72) 3.2 Glass Transition Temperature Tg

(73) The glass transition temperature T.sub.g of the epoxy resin compositions was determined by DSC (Differential Scanning calorimetry) in accordance with ASTM 3418/82.

(74) 3.3 Cupping test (DIN EN ISO1520)

(75) The elasticity of coatings on a metallic substrate is determined using the cupping test. A steel sheet was coated with the epoxy resin compositions (film thickness 100 m). The coated metal sheet was stored at room temperature overnight. In an apparatus for performing the cupping test, the sheet was deformed by forceful application of a die to the uncoated side, causing the coated side to bulge out correspondingly. The height of the bulge at which cracks are observed in the coating for the first time is a measure of the elasticity. The higher the bulge at the first cracks, the more elastic the coating. The values reported in the table are average values from three measurements.

(76) 3.4 Shore D Hardness

(77) The epoxy resin compositions were placed, in an amount of 10 g, into dishes having a radius of 4 cm, and stored at 25 C. for 7 days. For the determination of the Shore D hardness, a defined needle with defined length is pressed completely into the coating. The Shore D hardness corresponds to the force required to achieve this. The tables report the average values from 5 measurements. The greater the force, the higher the hardness.

(78) TABLE-US-00001 TABLE 1 Initial viscosity and reactivity Epoxy resin Diluent Hardener Initial parts by parts by parts by viscosity Reactivity No. weight type weight type weight mPas min 1 10 0 H1 3.4 577 180 2 9 ExoVC acrylate1 1 H1 4.0 340 28 3 7 ExoVC acrylate1 3 H1 5.3 310 9.8 4 5 ExoVC acrylate1 5 H1 6.8 125 4.2 5 3 ExoVC acrylate1 7 H1 8.0 80 3 6 9 ExoVC acrylate2 1 H1 3.7 565 41 7 7 ExoVC acrylate2 3 H1 4.5 521 13.6 8 5 ExoVC acrylate2 5 H1 5.2 236 6.1 9 3 ExoVC acrylate2 7 H1 5.9 187 4.1 10 9 ExoVC 1 H1 4.0 236 25.2 11 10 0 H2 2540 40 12 10 ExoVC acrylate1 0.5 H2 2.4 3000 34.4 13 10 ExoVC acrylate1 0.5 H2 2.6 2413 30.6 14 10 ExoVC acrylate1 0.5 H2 2.7 2515 36.6 15 10 ExoVC acrylate1 1 H2 2.7 2657 13.4 16 10 ExoVC 1 H2 2.5 1700 8.5

(79) TABLE-US-00002 TABLE 2 Cupping test and Shore hardness of the hardened epoxy resin compositions Epoxy compound Diluents Hardener Cupping parts by parts by parts by Tg test Shore D No. weight type weight type weight C. mm hardness 1 10 0 H1 3.4 92.6 0.6 89.5 2 9 ExoVC acrylate1 1 H1 4.0 69.9 9.0 89.0 3 7 ExoVC acrylate1 3 H1 5.3 41.8 9.0 86.6 4 5 ExoVC acrylate1 5 H1 6.8 24.7 9.0 76.9 5 3 ExoVC acrylate1 7 H1 8.0 9.0 36.9 6 9 ExoVC acrylate2 1 H1 3.7 74.8 0.7 88.4 7 7 ExoVC acrylate2 3 H1 4.5 53.7 0.9 87.6 8 5 ExoVC acrylate2 5 H1 5.2 33.8 9.0 86.5 9 3 ExoVC acrylate2 7 H1 5.9 22.5 9.0 77.7 10 9 ExoVC 1 H1 4.0 62.5 0.5 88.2