Polyester Carbonates From Cycloaliphatic Diacids, 1,4:3,6-Dianhydrohexitol and a Further Aliphatic Dihydroxy Compound

Abstract

-- The present invention relates to a process for preparing a polyestercarbonate proceeding from cycloaliphatic diacids and at least one 1,4:3,6-dianhydrohexitol and at least one further aliphatic dihydroxy compound, to the polyestercarbonate prepared by the process and also to a molding compound and a molded article including the polyestercarbonate. The process according to the invention is a direct synthesis in which all the structural elements that form the subsequent polyestercarbonate are already present as monomers in the first process step.

Claims

1. A process for preparing a polyestercarbonate by melt transesterification, comprising the steps of: (i) reaction at least of at least one cycloaliphatic dicarboxylic acid with at least one diaryl carbonate using at least one catalyst and in the presence of a mixture of dihydroxy compounds comprising (A) at least one 1,4:3,6-dianhydrohexitol and (B) at least one further aliphatic dihydroxy compound, and (ii) further condensation of the mixture obtained from process step (i), at least with removal of the chemical compound eliminated in the condensation, wherein the molar ratio of all dihydroxy compounds present in process step (i) to all cycloaliphatic dicarboxylic acids present in process step (i) prior to the reaction in process step (i) is 1:0.6 to 1:0.05.

2. The process as claimed in claim 1, wherein the at least one further aliphatic dihydroxy compound has the chemical formula (I): ##STR00009## in which X represents a linear alkylene group having 2 to 22 carbon atoms, which may optionally be interrupted by at least one heteroatom, a branched alkylene group having 4 to 20 carbon atoms, which may optionally be interrupted by at least one heteroatom, or a cycloalkylene group having 4 to 20 carbon atoms, which may optionally be interrupted by at least one heteroatom .

3. The process as claimed in claim 1, wherein the at least one further aliphatic dihydroxy compound is selected from the group consisting of 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2-bis(4-hydroxycyclohexyl)propane, tetrahydro-2,5-furandimethanol, 2-butyl-2-ethyl-1,3-propanediol, 2-(2-hydroxyethoxy)ethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, cyclobutane-1,1-diyldimethanol, 8-(hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and any desired mixtures thereof.

4. The process as claimed in claim 1, wherein the reaction in process step (i) is conducted in the presence of at least a first catalyst and/or a second catalyst and the condensation in process step (ii) is conducted at least in the presence of the first catalyst and the second catalyst, wherein the first catalyst is at least one tertiary nitrogen base, the second catalyst is at least one basic compound, and wherein the proportion of the alkali metal cations in process step (ii) is 0.0008% to 0.0030% by weight, based on all components used in process step (i).

5. The process as claimed in claim 1, wherein the at least one 1,4:3,6-dianhydrohexitol is isosorbide.

6. The process as claimed in claim 1, wherein the at least one cycloaliphatic dicarboxylic acid is selected from a compound of the chemical formula (IIa), (IIb) or mixtures thereof ##STR00010## ##STR00011## in which B each independently represents a CH.sub.2 group or a heteroatom selected from the group consisting of O and S, R.sub.1 each independently represents a single bond or an alkylene group having 1 to 10 carbon atoms, and n is a number between 0 and 3.

7. The process as claimed in claim 6, wherein the at least one cycloaliphatic dicarboxylic acid is selected from the group consisting of 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, tetradihydro-2,5-furandicarboxylic acid, tetradihydro-2,5-dimethylfurandicarboxylic acid, decahydro-2,4-naphthalenedicarboxylic acid, decahydro-2,5-naphthalenedicarboxylic acid, decahydro-2,6-naphthalenedicarboxylic acid, and decahydro-2,7-naphthalenedicarboxylic acid.

8. The process as claimed in claim 1, wherein the at least one diaryl carbonate is selected from the group consisting of a compound of formula (2) ##STR00012## 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 group.

9. The process as claimed in claim 6, wherein the at least one diaryl carbonate is diphenyl carbonate.

10. The process as claimed in claim 4, wherein the first catalyst is selected from the group consisting of guanidine-derived bases, 4-dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and mixtures of these substances.

11. The process as claimed in claim 1, wherein the at least one catalyst is used in an amount of 0.002% to 0.1% by weight, based on all components used in process step (i).

12. The process as claimed in claim 4, wherein the second catalyst is selected from the group consisting of inorganic or organic alkali metal salts and inorganic or organic alkaline earth metal salts.

13. A polyestercarbonate obtained by the process as claimed in claim 1.

14. A molding compound comprising a polyestercarbonate as claimed in claim 13.

15. A molded article comprising a polyestercarbonate as claimed in claim 13.

16. The process as claimed in claim 2, wherein the cycloalkylene group contains a plurality of rings and is branched.

17. The process as claimed in claim 4, wherein the first catalyst is used in an amount of 0.002% to 0.1% by weight, based on all components used in process step (i).

18. The process as claimed in claim 6, wherein: B each independently represents a CH.sub.2 group or an oxygen atom; R.sub.1 each independently represents a single bond; and n is 0 or 1.

19. The process as claimed in claim 1, wherein the molar ratio of all dihydroxy compounds present in process step (i) to all cycloaliphatic dicarboxylic acids present in process step (i) prior to the reaction in process step (i) is 1:0.5 to 1:0.15.

Description

EXAMPLES

[0098] Materials used: [0099] Cyclohexanedicarboxylic acid: 1,4-Cyclohexanedicarboxylic acid; CAS 1076-97-7 99%; Tokyo Chemical Industries, Japan, abbreviated as CHDA. The CHDA contained less than 1 ppm sodium per elemental analysis [0100] Diphenyl carbonate: Diphenyl carbonate, 99.5%, CAS 102-09-0; Acros Organics, Geel, Belgium, abbreviated as DPC [0101] 4-Dimethylaminopyridine: 4-dimethylaminopyridine; ≥98.0%; purum; CAS 1122-58-3; Sigma-Aldrich, Munich, Germany, abbreviated as DMAP [0102] Isosorbide: isosorbide (CAS: 652-67-5), 99.8%, Polysorb PS A; Roquette Freres (62136 Lestrem, France); abbreviated as ISB [0103] Lithium hydroxide monohydrate (CAS: 1310-66-3); >99.0%; Sigma-Aldrich [0104] 2-Butyl-2-ethyl-1,3-propanediol: CAS No.: 115-84-4; Aldrich (abbreviated as BEPD) [0105] 2,2,4,4-Tetramethyl-1,3-cyclobutanediol: 98% (CAS: 3010-96-6); ABCR (abbreviated as TMCBD) [0106] 2,2,4-Trimethyl-1,3-pentanediol; CAS No.: 144-19-4; Aldrich (abbreviated as TMPD) [0107] Neopentyl glycol (2,2-dimethylpropane-1,3-diol); CAS: 126-30-7; Aldrich (abbreviated as NPG) [0108] 1,4-Butanediol: CAS: 110-63-4; Merck 99%; (abbreviated as BDO) [0109] 1,4-Cyclohexanedimethanol: CAS: 105-08-8, Aldrich 99% (abbreviated as CHDM) [0110] 1,12-Dodecanediol: CAS: 5675-51-4, Aldrich 99% (abbreviated as DDD)

Analytical Methods

Solution Viscosity

[0111] 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. with an Ubbelohde viscometer. The determination was carried out in accordance with DIN 51562-3; 1985-05. This method involves measuring the flow times of the polyestercarbonate to be measured through the Ubbelohde viscometer in order to then ascertain the difference in viscosity between the polymer solution and its solvent. For this purpose, the Ubbelohde viscometer is first calibrated by measuring the pure solvents dichloromethane, trichloroethylene and tetrachloroethylene (always performing at least 3 measurements, but at most 9 measurements). This is followed by the calibration proper using the solvent dichloromethane. The polymer sample is then weighed out, dissolved in dichloromethane and then the flow time is determined three times for this solution. The average of the flow times is corrected via the Hagenbach correction and the relative solution viscosity calculated.

Determination of the Glass Transition Temperature

[0112] The glass transition temperature was 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. MALDI-ToF-MS

[0113] The sample was dissolved in chloroform. The matrix used was dithranol with LiCl. The sample was analyzed in positive reflector and linear modes.

Comparative Example 1 (Experiment Without Additional Diol)

[0114] A flask with a short-path separator was initially charged with 17.20 g (0.10 mol) of 1,4-cyclohexanedicarboxylic acid and 29.83 g (0.204 mol) of isosorbide, and also 64.30 g (0.3 mol) of diphenyl carbonate, 0.0111 g of DMAP (4-dimethylaminopyridine; 100 ppm based on the starting materials CHDA, DPC and ISB) and 115 .Math.l of an aqueous solution of lithium hydroxide (100 g/l), corresponding to approx. 30 ppm Li. The mixture was freed of oxygen by evacuating and venting with nitrogen four times. The mixture was melted and heated to 160° C. at standard pressure with stirring. The mixture was stirred for 40 minutes at 160°, for 60 minutes at 175° C., for 30 minutes at 190° C. for 10 minutes at 205° C. During this operation, carbon dioxide was continuously evolved. On cessation of CO.sub.2 evolution, the bath temperature was adjusted to 220° C. After a further 20 minutes, a vacuum was applied. The pressure was lowered to 10 mbar within 30 minutes. Phenol was continuously removed in the process. The mixture was stirred at 10 mbar for about 10 minutes. The pressure was then lowered to < 1 mbar (approx. 0.7 mbar) and the condensation was continued for a further 10 minutes. Processing of the mixture was then stopped.

[0115] A light yellow polymer having a solution viscosity of eta rel 1.33 was obtained.

[0116] The other examples (Ex.) and comparative examples (Comp.) were carried out as stated for comparative example 1. In a departure from example 1, the aliphatic diols respectively specified in table 1 were in addition initially charged in the flask with a short-path separator, together with all the other polymer-forming monomers and the catalyst.

TABLE-US-00001 Co mp. 1 Inv. 1 Inv. 2 Inv. 3 Inv. 4 Inv. 5 Inv. 6 Inv. 7 Inv. 8 Inv. 9 Inv. 10 Inv. 11 Inv. 12 Co MP. 2 CHDA / ISB / OH—R—OH molar ratio 33/6 7/0 33/6 4/3 33/6 0/7 33/5 7/10 33/6 4/3 33/5 7/10 33/6 0/7 33/6 4/3 33/6 4/3 33/5 7/10 33/6 4/3 33/6 4/3 33/5 7/10 44/4 9/7 Diol: CHDA sum ratios appr ox. 1:0. 5 appr ox. 1:0. 5 appr ox. 1:0. 5 appr ox. 1:0.5 appr ox. 1:0. 5 appr ox. 1:0.5 appr ox. 1:0. 5 appr ox. 1:0. 5 appr ox. 1:0.5 appr ox. 1:0.5 appr ox. 1:0. 5 appr ox. 1:0. 5 appr ox. 1:0.5 appr ox. 1:0. 85 CHDA (mol) approx. 0.1 0.2 0.2 0.2 0.2 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.15 8 HO—R—OH approx. (mol) 0 0.02 TM PD 0.04 TM PD 0.06 TMP D 0.02 NP G 0.06 NPG 0.02 BEP D 0.01 BEP D 0.01 TMC BD 0.03 TMC BD 0.01 BD O 0.01 CH DM 0.03 DDD 0.02 BEP D DPC (mol) approx. 0.3 0.6 0.6 0.6 0.6 0.6 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.358 ISB (mol) approx. 0.2 0.38 0.36 0.34 0.38 0.34 0.18 0.19 0.19 0.17 0.19 0.19 0.17 0.184 Eta rel 1.33 1.383 1.362 1.647 1.413 1.446 1.501 1.474 1.434 1.606 1.396 1.41 1.301 1.023 Glass transition temperature in °C 151 144 146 138 150 147 133 142 154 153 145 145 94 The mol data in the first column of table 1 are reported as “approx.” since they were rounded to the second decimal place. The ratio 2.04:1.00 (diols to diacids) served as a basis.

[0117] Examples 1 to 12 according to the invention show that the process of the invention affords the desired polyestercarbonates in high viscosities provided that the ratios of isosorbide to CHDA according to the invention are observed. It can be seen here that the addition of a further aliphatic diol, especially of branched diols, causes the molecular weight to rise significantly compared to an example in which no further aliphatic diol is present (see comparative example 1). Better miscibility was observed at higher temperatures, which meant it was possible for a further increase in molecular weight to take place. It is moreover surprising that polymers having certain ISB+further aliphatic diol:CHDA ratios do not exhibit a good increase in molecular weight. Comparative example 2 shows that ratios with larger proportions of cyclohexanedicarboxylic acid do not lead to the desired polymers and the molecular weights obtained are very low. This was moreover not known/not inferable from the literature. In the as-yet unpublished patent application PCT/EP2019/084847, it has already been found that the ratio of ISB:CHDA leads to a good increase in molecular weight over the broad defined range according to the invention, but not outside of this range. The addition of at least one further aliphatic diol leads, as can be seen from the comparison with comparative example 1, to an even greater increase in molecular weight (see above).

Example 13 According to the Invention: Reaction in Process Step (i)

[0118] A flask with a short-path separator was initially charged with 0.10 mol of 1,4-cyclohexanedicarboxylic acid, 0.02 mol of BEPD (10%) and 0.18 mol of isosorbide, and also 0.3 mol of diphenyl carbonate and 100 ppm of DMAP (4-dimethylaminopyridine; based on the starting materials CHDA, BEPD, DPC, and ISB) and 0.0763 ml of an aqueous solution of lithium hydroxide (100 g/l), corresponding to approx. 20 ppm Li. The mixture was freed of oxygen by evacuating and venting with nitrogen four times. The mixture was heated gradually up to 190° C. During this operation, carbon dioxide was continuously evolved. A 3 ml sample was then taken and analyzed by MALDI-ToF-MS. To ensure that the batch continued to polymerize, the reaction was heated to 220° C. and the vacuum then reduced in steps to < 1 mbar. An increase in viscosity was observed.

[0119] The results of the analysis are summarized in table 2. The respective masses correspond to the Li adduct M+Li*. Various peaks were identified in which not only the ISB but also the BEPD might already have reacted. This is a clear indication that the isosorbide and the BEPD already react under the process conditions of process step (i). In table 2, ISB denotes an isosorbide unit minus the two OH end groups (these are described separately), CHDA stands for cyclohexane (cyclohexanedicarboxylic acid minus the two carboxylic acid groups), and BEPD stands for 2-butyl-2-ethyl-1,3-propanediol minus the two OH groups.

TABLE-US-00002 Peaks in the MALDI-ToF spectrum Possible structure 383 Da HO-ISB-ester-CHDA-ester-phenyl 397 Da HO-BEPD-ester-CHDA-ester-phenyl 512 Da HO-ISB-carbonate-ISB-carbonate-BEPD-OH 555 Da HO-ISB-carbonate-ISB-ester-CHDA-ester-phenyl 607 Da HO-ISB-carbonate-ISB-ester-CHDA-ester-ISB-OH 613 Da Phenyl-ester-CHDA-ester-ISB-ester-CHDA-ester-phenyl 627 Da Phenyl-ester-CHDA-ester-BEPD-ester-CHDA-ester-phenyl 665 Da HO-ISB-ester-CHDA-ester-ISB-ester-CHDA-ester-phenyl 679 Da Phenyl-ester-CHDA-ester-ISB-ester-CHDA-ester-BEPD-OH 727 Da HO-ISB-carbonate-ISB-carbonate-ISB-ester-CHDA-ester-phenyl 785 Da Phenyl-ester-CHDA-ester-ISB-ester-CHDA-ester-ISB-carbonate-phenyl 837 Da HO-ISB-carbonate-ISB-ester-CHDA-ester-ISB-ester-CHDA-ester-phenyl

[0120] These results suggest that the process of the invention leads to a polyestercarbonate that differs from a polyestercarbonate prepared via a two-stage process (i.e. preparation first of a diaryl dicarboxylate by reaction of a cycloaliphatic dicarboxylic acid with a diaryl carbonate, purification of said diaryl dicarboxylate, and subsequent condensation of the diaryl dicarboxylate with a diaryl carbonate and an aliphatic dihydroxy compound). It is highly likely that different statistical distributions of carbonate units and/or ester units are present in the different polyestercarbonates.