POLYESTER CARBONATES FROM CYCLOALIPHATIC DIACIDS AND ALIPHATIC DIOLS, AND PROCESS FOR PREPARING SAME

Abstract

The present invention relates to a method for preparing a polyester carbonate starting from cycloaliphatic diacids and aliphatic diols and to the polyester carbonate prepared by the method. The method according to the invention is a direct synthesis in which all the structural elements that form the subsequent polyester carbonate are already present as monomers in the first step of the method.

Claims

1.-15. (canceled)

16. A method for preparing a polyester carbonate by melt transesterification, comprising the steps of (i) reacting at least one cycloaliphatic dicarboxylic acid with at least one diaryl carbonate using at least one catalyst and in the presence of at least one aliphatic dihydroxy compound and (ii) subjecting the mixture obtained from step (i) of the method to further condensation, at least with removal of the chemical compound eliminated in the condensation, wherein the molar ratio of all aliphatic dihydroxy compounds present in step (i) of the method to all cycloaliphatic dicarboxylic acids present in step (i) of the method prior to reaction in step (i) of the method is 1:0.6 to 1:0.05.

17. The method according to claim 16, wherein the at least one aliphatic dihydroxy compound is selected from the group consisting of cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cyclohexane-1,2-dimethanol, cyclohexane-1,3-dimethanol, cyclohexane-1,4-dimethanol, tricyclodecanedimethanol, 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 2,2-bis(4-hydroxycyclohexyl)propane, tetrahydro-2,5-furandimethanol and 1,4:3,6-dianhydrohexitols such as isomannide, isoidide and isosorbide.

18. The method according to claim 17, wherein the at least one aliphatic dihydroxy compound is isosorbide.

19. The method according to claim 16, wherein the at least one cycloaliphatic dicarboxylic acid is selected from a compound of the chemical formula (IIa), (IIb) or mixtures thereof ##STR00005## in which B in each case independently represents a carbon atom or a heteroatom selected from the group consisting of O, S and N and n is a number between 0 and 3.

20. The method according to claim 19, wherein the at least one cycloaliphatic dicarboxylic acid is selected from the group consisting of cyclohexane-1,4-dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, tetradihydro-2,5-furandicarboxylic acid, tetradihydro-2,5-dimethylfurandicarboxylic acid, decahydronaphthalene-2,4-dicarboxylic acid, decahydronaphthalene-2,5-dicarboxylic acid, decahydronaphthalene-2,6-dicarboxylic acid and decahydronaphthalene-2,7-dicarboxylic acid.

21. The method according to claim 16, wherein the at least one diaryl carbonate is selected from the group consisting of a compound of the formula (2) ##STR00006## in which R, R′ and R″ may each independently be identical or different and represent hydrogen, optionally branched C1-C34 alkyl, C7-C34 alkylaryl, C6-C34 aryl, a nitro group, a carbonyl-containing group, a carboxyl-containing group or a halogen moiety.

22. The method according to claim 21, wherein the at least one diaryl carbonate is diphenyl carbonate.

23. The method according to claim 16, wherein the molar ratio of the sum of all aliphatic dihydroxy compounds present in step (i) of the method and all cycloaliphatic dicarboxylic acids present in step (i) of the method to all diaryl carbonates present in step (i) of the method prior to reaction in step (i) of the method is 1:0.4 to 1:1.6.

24. The method according to claim 16, wherein step (ii) of the method is carried out at temperatures in the range from 210° C. to 280° C.

25. The method according to claim 16, wherein all monomers that are to undergo condensation to the polyester carbonate in step (ii) of the method are already present during step (i) of the method.

26. The method according to claim 16, wherein the chemical compound eliminated in the condensation is removed in step (ii) of the method by means of reduced pressure.

27. The method according to claim 16, wherein the polyester carbonate prepared has a relative solution viscosity eta rel of 1.12 to 1.60.

28. The method according to claim 16, wherein at least one inorganic base and/or at least one organic catalyst is used in step (i) of the method.

29. The method according to claim 28, wherein the at least one inorganic base or the at least one organic catalyst is selected from the group consisting of the hydroxides, carbonates, halides, phenoxides, diphenoxides, fluorides, acetates, phosphates, hydrogen phosphates and borates of lithium, sodium, potassium, caesium, calcium, barium and magnesium, tetramethylammonium hydroxide, tetramethylammonium acetate, tetramethylammonium fluoride, tetramethylammonium tetraphenylborate, tetraphenylphosphonium fluoride, tetraphenylphosphonium tetraphenylborate, dimethyldiphenylammonium hydroxide, tetraethylammonium hydroxide, cetyltrimethylammonium tetraphenylborate, cetyltrimethylammonium phenoxide, diazabicycloundecene (DBU), diazabicyclononene (DBN), 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-phenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7′-hexylidenedi-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7′-decylidenedi-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7,7′-dodecylidenedi-1,5,7-triazabicyclo[4.4.0]dec-5-ene, the phosphazene base P1-t-oct (tert-octyliminotris(dimethylamino)phosphorane), the phosphazene base P1-t-butyl (tert-butyl-iminotris(dimethylamino)phosphorane) and 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diaza-2-phosphorane (BEMP).

30. A polyester carbonate obtained by the method according to claim 16.

Description

EXAMPLES

[0061] Materials Used:

[0062] Cyclohexanedicarboxylic acid: cyclohexane-1,4-dicarboxylic acid; CAS 1076-97-7, 99%; Sigma-Aldrich, Munich, Germany, abbreviated to CHDA

[0063] Hydrogenated dimer acid CAS 68783-41-5≥98%, Sigma-Aldrich, Munich, Germany, as comparator substance

[0064] Diphenyl carbonate: diphenyl carbonate, 99.5%, CAS 102-09-0; Acros Organics, Geel, Belgium, abbreviated to DPC 4-Dimethylaminopyridine: 4-(dimethylamino)pyridine; >98.0%; purum; CAS 1122-58-3; Sigma-Aldrich, Munich, Germany

[0065] Isosorbide: isosorbide (CAS: 652-67-5), 99.8%, Polysorb PS A; Roquette Freres (62136 Lestrem, France); abbreviated to ISB

[0066] Dimethyl cyclohexane-1,4-dicarboxylate: CAS 94-60-0 Sigma Aldrich (97%); cis/trans mixture

[0067] Analytical Methods:

[0068] Determination of the glass transition temperature:

[0069] The glass transition temperature is determined by differential scanning calorimetry (DSC) in accordance with standard DIN EN ISO 11357-1:2009-10 and ISO 11357-2:2013-05 at a heating rate of 10 K/min under nitrogen with determination of the glass transition temperature (Tg) measured as the point of inflection in the second heating run.

[0070] Chemical Characterization:

[0071] .sup.1H NMR: 600 MHz; Bruker AV III HD 600 spectrometer; solvent: CDCl.sub.3

[0072] Solution Viscosity

[0073] Determination of solution viscosity: The relative solution viscosity (ηrel; also referred to as eta rel) was determined in dichloromethane at a concentration of 5 g/l at 25° C. using an Ubbelohde viscometer.

[0074] Gel-Permeation Chromatography

[0075] Mass-average molar mass M.sub.w, number-average molar mass M.sub.n and dispersity (D) values were determined by gel-permeation chromatography using dichloromethane as eluent, calibration with polystyrene standard, measured by Currenta GmbH & Co. OHG, Leverkusen. The eluent for the calibration is likewise dichloromethane. Column combination of crosslinked styrene-divinylbenzene resins. Diameter of analytical columns: 7.5 mm; length: 300 mm. Particle sizes of column material: 3 μm to 20 μm. Concentration of solutions: 1.0 g/l. Flow rate: 1.0 ml/min, temperature of solutions: 21° C. Detection using a refractive index (RI) detector.

[0076] MALDI-ToF-MS

[0077] The sample was dissolved in chloroform. The matrix used was Dithranol with LiCl. The sample was analysed in positive reflector and linear modes.

Example 1: Inventive; ISB:CHDA 1:0.5

[0078] A flask fitted with a short-path separator was charged with 17.22 g (0.10 mol) of cyclohexane-1,4-dicarboxylic acid, 29.815 g (0.204 mol) of isosorbide, 64.26 g (0.3 mol) of diphenyl carbonate and 0.01113 g (100 ppm), equivalent to 0.010% by weight, of DMAP (4-dimethylaminopyridine). The mixture was freed of oxygen by evacuating and releasing the vacuum with nitrogen four times. The mixture was melted and heated to 160° C. at standard pressure with stirring. The temperature was increased to 240° C. in stages, in line with the observed reactivity. Stirring was continued until CO.sub.2 evolution ceased: this took approximately 1 hour (from melting at 160° C.). During this operation, phenol was distilled off.

[0079] On cessation of CO.sub.2 evolution, the pressure was lowered cautiously to 100 mbar in stages over a period of approximately 20 minutes. During this operation, phenol was continuously distilled off. Evacuation was continued until a pressure of less than 1 mbar was reached. Stirring was continued at this pressure for approximately 30 minutes further, after which mixing was stopped.

[0080] Crude product 5.9 g of brown resin; NMR (1H NMR) confirmed that the desired compound had been obtained.

[0081] A light brown polymer with a solution viscosity of eta rel 1.335 was obtained.

[0082] Further data are given in table 1.

Example 2: Inventive; ISB:CHDA 1:0.4

[0083] The test was essentially carried out as described in example 1, except that 17.22 g (0.10 mol) of cyclohexane-1,4-dicarboxylic acid, 37.26 g (0.255 mol) of isosorbide and 74.97 g (0.35 mol) of diphenyl carbonate were used. The same amount of catalyst as in example 1 was used.

[0084] A light brown polymer with a solution viscosity of eta rel 1.288 was obtained.

Example 3: Inventive; ISB:CHDA 1:0.3

[0085] The test was essentially carried out as described in example 1, except that 17.22 g (0.10 mol) of cyclohexane-1,4-dicarboxylic acid, 49.25 g (0.337 mol) of isosorbide and 92.75 g (0.433 mol) of diphenyl carbonate were used. The same amount of catalyst as in example 1 was used.

[0086] A light brown polymer with a solution viscosity of eta rel 1.278 was obtained.

Example 4: Comparative Example 1: ISB:CHDA=1:1

[0087] The test was essentially carried out as described in example 1, except that 17.20 g (0.10 mol) of cyclohexane-1,4-dicarboxylic acid, 14.90 g (0.102 mol) of isosorbide and 42.80 g (0.20 mol) of diphenyl carbonate were used. The same amount of catalyst as in example 1 was used.

[0088] A brittle brown melt with a solution viscosity of eta rel 1.025 was obtained.

Example 5: Comparative Example 1: ISB:CHDA=0.8:1

[0089] The test was essentially carried out as described in example 1, except that 17.20 g (0.10 mol) of cyclohexane-1,4-dicarboxylic acid, 18.70 g (0.128 mol) of isosorbide and 48.20 g (0.225 mol) of diphenyl carbonate were used. The same amount of catalyst as in example 1 was used.

[0090] A brittle brown melt with a solution viscosity of eta rel 1.053 was obtained.

Example 6: Comparative Example, Using the Dimethyl Ester of CHDA Instead of CHDA

[0091] The test was essentially carried out as described in example 1, except that 20.20 g (0.10 mol) of dimethyl cyclohexane-1,4-dicarboxylate, 37.26 g (0.255 mol) of isosorbide and 32.13 g (0.15 mol) of diphenyl carbonate were used. The same catalyst as in example 1 was used, but in an amount of 1000 ppm.

[0092] A brittle brown melt with a solution viscosity of eta rel 1.054 was obtained.

Example 7: Comparative Example Using Noninventive Acid

[0093] The test was essentially carried out as described in example 1, except that 27.70 g (0.05 mol) of hydrogenated dimer acid (CAS 68783-41-5), 24.64 g (0.169 mol) of isosorbide and 46.40 g (0.217 mol) of diphenyl carbonate were used. The same amount of catalyst as in example 1 was used.

[0094] A liquid product was obtained. Determination of the solution viscosity was omitted, as it was clear that inadequate polymer growth had taken place.

TABLE-US-00001 TABLE 1 Example 4 Example 5 Example 1 Example 2 Example 3 Example 6 ISB:CHDA approx. approx. approx. approx. approx. approx. ratios 1:1 1:0.8 1:0.5 1:0.4 1:0.3 1:0.4 CHDA (mol) 0.10 0.10 0.10 0.10 0.10 0.10 (as dimethyl ester) DPC (mol) 0.2 0.225 0.30 0.35 0.433 0.15 ISB (mol) 0.102 0.128 0.204 0.255 0.337 0.255 Catalyst 100 ppm 100 ppm 100 ppm 100 ppm 100 ppm 1000 ppm DMAP DMAP DMAP DMAP DMAP DMAP Eta rel 1.025 (n.p.) 1.053 (n.p.) 1.391 (n.p.) 1.29 (n.p.) 1.28 (n.p.) 1.054 (n.p.) GPC — — Mn = Mn = Mn = 23 360 g/mol 31 000 g/mol 27 400 g/mol Mw = Mw = Mw = 90 430 g/mol 61 000 g/mol 64 400 g/mol (n.p.) (n.p.) (n.p.) DSC — — 151 (p.) 154 (p.) 156 (p.)

[0095] The abbreviation n.p. stands for “not precipitated”

[0096] The abbreviation p. stands for “precipitated”; the polymer was in each case precipitated in methanol.

[0097] Examples 1 to 3 show that the inventive method afforded the desired polyester carbonate in high viscosities provided the ratios of isosorbide to CHDA according to the invention had been conformed to.

[0098] This was surprising, given that transesterification reactions starting from free acids do not work well (see Jayakannan, J. Polym. Sci, Part A: Polymer Chemistry, 2004 vol. 42, 3996). Transesterification reactions starting from aliphatic esters (see comparative example 6) surprisingly show only very minimal growth in molecular weight, even though the ratios according to the invention had been conformed to.

[0099] Likewise, the comparison of example 7 with example 3 shows that the choice of acid component is important for adequate polymer growth. If an acid as described in US 2009/105393 A1 is used, only a liquid product is obtained.

[0100] Also surprising is that polymers having specific ISB:CHDA ratios cannot be synthesized. Thus, comparative examples 4 and 5 show that ratios with larger proportions of cyclohexanedicarboxylic acid do not afford the desired polymers and that the molecular weights obtained are very low. This was moreover not known/not inferrable from the literature.

Example 8: Reaction in Step (i) of the Method

[0101] A flask fitted with a short-path separator was charged with 17.22 g (0.10 mol) of cyclohexane-1,4-dicarboxylic acid, 29.228 g (0.20 mol) of isosorbide, 42.84 g (0.2 mol) of diphenyl carbonate and 0.0089 g (100 ppm) of DMAP (4-dimethylaminopyridine). The mixture was freed of oxygen by evacuating and releasing the vacuum with nitrogen four times. The mixture was melted at 160° C., after which the temperature was raised to 190° C. Over a period of approx. 30 minutes, the temperature was raised to 240° C. The mixture was stirred at 240° C. for approx. 30 minutes. A slight vacuum was then applied for 20 minutes, with the pressure reduced in stages; after 20 minutes the pressure had decreased to 200 mbar and the reaction was stopped. The slight vacuum was for the purposes of removing phenol, since this otherwise interferes with the analysis.

[0102] To remove residual amounts of phenol and polar substances such as CHDA, the mixture was dissolved in dichloromethane and extracted with water three times. The product was analysed by MALDI-ToF-MS.

[0103] Peaks 172 Da apart were observed, which is clear evidence of the formation of ISB carbonate units (the mass corresponds to a Li adduct: M+Li*).

[0104] In addition, peaks at 555 Da were identified that could correspond to HO-ISB-carbonate-ISB-ester-CHDA-phenyl (where ISB denotes an isosorbide unit minus the two terminal OH groups (these are described separately); CHDA represents cyclohexane (cyclohexanedicarboxylic acid minus the two carboxylic acid groups)).

[0105] The peak observed at 607 Da could correspond to an HO-ISB-carbonate-ISB-ester-CHDA-ester-ISB-OH oligomer.

[0106] Likewise, the peak observed at 717 Da could correspond to an HO-ISB-carbonate-ISB-carbonate-ISB-OH oligomer. A further peak at 665 Da could correspond to the presence of HO-ISB-ester-CHDA-ester-ISB-ester-CHDA-ester-phenyl and one at 837 Da to this plus a further ISB unit.

Example 9: Inventive; ISB:CHDA 1:0.5; Different Catalyst)

[0107] The test was essentially carried out as described in example 1, except that a flask fitted with a short-path separator was charged with 17.22 g (0.10 mol) of cyclohexane-1,4-dicarboxylic acid, 29.815 g (0.204 mol) of isosorbide, 64.26 g (0.3 mol) of diphenyl carbonate and 0.0555 g (500 ppm), equivalent to 0.010% by weight, of DBN (1,5-diazabicyclo[4.3.0]non-5-ene).

[0108] A light brown polymer with a solution viscosity of eta rel 1.14 was obtained.