PROCESS FOR THE PREPARATION OF FUNCTIONALIZED POLYOXYALKYLENE POLYOLS

Abstract

A process for preparing halogen-containing polyoxyalkylenepolyols, comprising the step of reacting an alkylene oxide with carbon dioxide in the presence of an H-functional starter compound and of a double metal cyanide catalyst, wherein the reaction is also conducted in the presence of an α,β-epoxy-γ-haloalkane.

Claims

1. A process for preparing polyoxyalkylenepolyols, comprising reacting an alkylene oxide with carbon dioxide in the presence of an H-functional starter compound and of a double metal cyanide catalyst, and an α,β-epoxy-γ-haloalkane.

2. The process as claimed in claim 1, wherein the α,β-epoxy-γ-haloalkane comprises at least one of epichlorohydrin, epibromohydrin and epiiodohydrin.

3. The process as claimed in claim 1, wherein the alkylene oxide comprises ethylene oxide and/or propylene oxide.

4. The process as claimed in claim 1, wherein the alkylene oxide and the α,β-epoxy-γ-haloalkane are used in a molar ratio of ≥99:1 to ≤50:50.

5. The process as claimed in claim 1, wherein the H-functional starter compound comprises a polyol.

6. The process as claimed in claim 1, wherein the reaction is conducted in a reactor and comprises (α) initially charging the reactor with a suspension medium containing no H-functional groups, and (γ) continuously metering one or more H-functional starter substances into the reactor during the reaction.

7. The process as claimed in claim 6, wherein, in (α) when the suspension medium is initially charged, no H-functional starter substance is initially charged in the reactor or a portion of the H-functional starter substance is initially charged in the reactor.

8. The process as claimed in claim 6, wherein, in (α), the suspension medium is initially charged together with a double metal cyanide catalyst.

9. The process as claimed in claim 8, wherein (α) is followed by (β) adding a portion of alkylene oxide to the mixture from (α) at temperatures of 90 to 150° C., and then stopping the addition of the alkylene oxide.

10. The process as claimed in claim 9, wherein, in (β), (β1) adding a first portion of alkylene oxide in a first activation stage under an inert gas atmosphere and (β2) adding a second portion of alkylene oxide in a second activation stage under a carbon dioxide atmosphere.

11. The process as claimed in claim 6, wherein the continuously metered addition in (γ) of the H-functional starter substances in (γ) is ended before the addition of the alkylene oxide.

12. The process as claimed in claim 6, wherein the continuously metered addition of the α,β-epoxy-γ-haloalkane and of the carbon dioxide in (γ) is simultaneous.

13. A polyoxyalkylenepolyol obtainable by a process as claimed in claim 1.

14. A polyoxyalkylenepolyol as claimed in claim 13 having a content of units originating from the α,β-epoxy-γ-haloalkane of ≥1 mol % to ≤30 mol %.

15. A polyurethane polymer obtainable from the reaction of a polyol component comprising a polyoxyalkylenepolyol as claimed in claim 13 with at least one polyisocyanate component.

16. The process as claimed in claim 4, wherein the alkylene oxide and α,β-epoxy-γ-haloalkane are used in a molar ratio of ≥95:5 to ≤50:50.

17. The polyoxyalkylene polyol as claimed in claim 14 having a content of units originating from the α,β-epoxy-γ-haloalkane of ≥3 mol % to ≤15 mol %.

Description

EXAMPLES

[0193] The invention is more particularly described with reference to the examples which follow but without any intention to limit the invention thereto.

[0194] H-functional starter compounds (starters) used:

[0195] PET-1 difunctional poly(oxypropylene)polyol having an OH number of 112 mg.sub.KoH/g

[0196] The DMC catalyst was prepared according to example 6 of WO-A 01/80994.

[0197] Epichlorohydrin (ECH), 99% purity, Fluka

[0198] Carbon dioxide (CO2), 99.995% purity, Westfalen

[0199] Propylene oxide (PO), 99.9% purity, Chemogas GmbH

[0200] HDI trimer triisocyanate with an average molar NCO functionality of 3.4

[0201] Desmodur N3300 from Covestro AG, equivalent weight 192 g/mol, NCO content 21.7% by weight

[0202] DBTL dibutyltin dilaurate from Sigma Aldrich, purity >95%

[0203] The 300 ml pressure reactor used in the examples had a height (internal) of 10.16 cm and an internal diameter of 6.35 cm. The reactor was equipped with an electrical heating jacket (maximum heating power 510 watts). The counter-cooling consisted of an immersed tube of external diameter 6 mm which had been bent into a U shape and which projected into the reactor up to 5 mm above the base, and through which cooling water flowed at about 10° C. The water flow was switched on and off by means of a magnetic valve. In addition, the reactor was equipped with an inlet tube and a thermal sensor of diameter 1.6 mm, which projected into the reactor up to 3 mm above the base.

[0204] The heating power of the electrical heating jacket during activation [step (β)] was on average about 20% of the maximum heating power. As a result of the closed-loop control, the heating power varied by 5% of the maximum heating power. The occurrence of increased evolution of heat in the reactor, brought about by the rapid reaction of propylene oxide during the activation of the catalyst [step (β)], was observed via reduced heating power of the heating jacket, engagement of the counter-cooling, and, as the case may be, a temperature increase in the reactor. The occurrence of evolution of heat in the reactor, brought about by the continuous reaction of propylene oxide during the reaction [step (γ)], led to a fall in the power of the heating jacket to about 8% of the maximum heating power. As a result of the closed-loop control, the heating power varied by 5% of the maximum heating power.

[0205] The hollow shaft stirrer used in the examples was a hollow shaft stirrer in which the gas was introduced into the reaction mixture via a hollow shaft in the stirrer. The stirrer body mounted on the hollow shaft comprised four arms having a diameter of 35 mm and a height of 14 mm. The arm was equipped at each end with two gas outlets of 3 mm in diameter. The turning of the stirrer created a negative pressure such that the gas above the reaction mixture was sucked away and was introduced into the reaction mixture via the hollow shaft of the stirrer.

[0206] The reaction mixture was characterized by .sup.1H-NMR spectroscopy.

[0207] The proportion of the unconverted monomers (propylene oxide R.sub.PO, epichlorohydrin R.sub.ECH in mol %) was determined by means of .sup.1H NMR spectroscopy. For this purpose, a sample of each reaction mixture obtained after the reaction was dissolved in deuterated chloroform and measured on a Bruker spectrometer (AV400, 400 MHz).

[0208] Subsequently, the reaction mixture was diluted with dichloromethane (20 ml) and the solution was passed through a falling-film evaporator. The solution (0.1 kg in 3 h) ran downwards along the inner wall of a tube of diameter 70 mm and length 200 mm which had been heated externally to 120° C., in the course of which the reaction mixture was distributed homogeneously as a thin film on the inner wall of the falling-film evaporator in each case by three rollers of diameter 10 mm rotating at a speed of 250 rpm. Within the tube, a pump was used to set a pressure of 3 mbar. The reaction mixture which had been purified to free it of volatile constituents (unconverted epoxides, cyclic carbonate, solvent) was collected in a receiver at the lower end of the heated tube.

[0209] The relevant resonances in the .sup.1H NMR spectrum (based on TMS=0 ppm) which were used for integration are as follows:

[0210] I1: 1.10-1.17 ppm: methyl group of the polyether units, resonance area corresponds to three hydrogen atoms,

[0211] I2: 1.25-1.34 ppm: methyl group of the polycarbonate units, resonance area corresponds to three hydrogen atoms,

[0212] I3: 1.45-1.48 ppm: methyl group of the cyclic carbonate, resonance area corresponds to three hydrogen atoms

[0213] I4: 2.82-3.85 ppm: CH group for free, unreacted epichlorohydrin, resonance area corresponds to one hydrogen atom.

[0214] I5: 2.95-3.00 ppm: CH group for free, unreacted propylene oxide, resonance area corresponds to one hydrogen atom.

[0215] The molar proportion of the unconverted propylene oxide (R.sub.PO in mol %) based on the sum total of the amount of propylene oxide used in the activation and the copolymerization is calculated by the formula:

R.sub.ECH=[I4/((I1/3)+(I2/3)+(I3/3)+I4+I5))]×100%

The molar proportion of the unconverted propylene oxide (R.sub.PO in mol %) based on the sum total of the amount of propylene oxide used in the activation and the copolymerization is calculated by the formula:

R.sub.MA=[(I5/2)/((I1/3)+(I2/3)+(I3/3)+(I4)+(I5/2)+(I7/2))]×100%

[0216] The proportion (% by weight) of CO.sub.2 incorporated into the polymer was determined by means of .sup.1H NMR spectroscopy.

CO.sub.2 incorporation=[I2*102/((I1/3)*58+(I2/3)*102))]×100%

[0217] The number-average M.sub.n and the weight-average M.sub.w of the molecular weight of the resulting polymers was determined by gel permeation chromatography (GPC). The procedure of DIN 55672-1 was followed: “Gel permeation chromatography, Part 1—Tetrahydrofuran as eluent” (SECurity GPC System from PSS Polymer Service, flow rate 1.0 ml/min; columns: 2×PSS SDV linear M, 8×300 mm, 5 μm; RID detector). Polystyrene samples of known molar mass were used for calibration.

[0218] The OH number (hydroxyl number) was determined based on DIN 53240-2 but using N-methylpyrrolidone rather than THF/dichloromethane as solvent. A 0.5 molar ethanolic KOH solution was used for titration (endpoint recognition by potentiometry). The test substance used was castor oil with certified OH number. The reporting of the unit in “mg/g” relates to mg[KOH]/g[polyetherthiocarbonatepolyol].

[0219] Viscosity was determined on an Anton Paar Physica MCR 501 rheometer. A cone-plate configuration having a separation of 1 mm was selected (DCP25 measurement system). The polythioethercarbonate polyol (0.1 g) was applied to the rheometer plate and subjected to a shear of 0.01 to 1000 l/s at 25° C. and the viscosity was measured every 10 s for 10 min. The figure reported is the viscosity averaged over all measurement points.

[0220] For rheological determination of the gel point for the polyurethane polymer the polythioethercarbonate polyols were admixed with an equimolar amount of Desmodur N3300 (hexamethylene diisocyanate trimer) and 2000 ppm of dibutyltin laurate (2% in diphenyl ether). The complex moduli G′ (storage modulus) and G″ (loss modulus) were determined in an oscillation measurement at 40° C. and a frequency of 1 Hz, using a plate/plate configuration with a plate diameter of 15 mm, a plate-to-plate distance of 1 mm, and a 10 percent deformation. The gel point was defined as the time at which G′=G″.

Example 1: Preparation of a Halogen-Containing Polyoxyalkylenecarbonate Polyol by Polymerization of Propylene Oxide, 13.5 Mol % of Epichlorohydrin and CO.SUB.2

[0221] [First Activation Stage, Step (α)]

[0222] A 300 ml pressure reactor fitted with a sparging stirrer was initially charged with a mixture of DMC catalyst (27 mg) and PET-1 (30 g). The reactor was sealed and the pressure in the reactor reduced to 5 mbar for five minutes. The pressure in the reactor was then adjusted to 50 mbar by application of a gentle Ar stream and simultaneous removal of the gas with a pump. The reactor was heated to 130° C. and the mixture was stirred (800 rpm) at 130° C. under reduced pressure (50 mbar) and a gentle Ar stream for 30 minutes. [Second activation stage, step (β)]

[0223] CO.sub.2 was injected to 15 bar, which caused the temperature in the reactor to drop slightly. The temperature was kept at 130° C. by closed-loop control and, during the subsequent steps, the pressure in the reactor was kept at 15 bar by metering in further CO.sub.2. 3.0 g of propylene oxide were metered in with the aid of an HPLC pump (1 ml/min) and the reaction mixture was stirred (800 rpm) for 20 min. The occurrence of a brief increase in evolution of heat in the reactor during this time indicated the activation of the catalyst. Subsequently, two further portions each of 3.0 g of propylene oxide were metered in by means of the HPLC pump (1 mL/min) and the reaction mixture was stirred for 20 min (800 rpm). The occurrence of a brief increase in evolution of heat in the reactor during this time confirmed the activation of the catalyst.

[0224] [Polymerization Stage, Step (γ)]

[0225] After cooling to 105° C., a further 38.0 g of propylene oxide were metered in by means of an HPLC pump (0.91 ml/min) with continued stirring. 10.5 min after commencement of the addition of propylene oxide, 12 g of epichlorohydrin were simultaneously metered in by means of an HPLC pump (0.26 ml/min). The reaction mixture was then stirred at 105° C. for a further 1 h. The reaction was stopped by cooling the reactor with ice water, the positive pressure was released and the resulting product analyzed.

[0226] The molar proportion of unconverted propylene oxide (R.sub.PO in mol %) was 4.0%, and that of unconverted epichlorohydrin (R.sub.ECH in mol %) was 3.0 mol %.

[0227] The CO.sub.2 content incorporated in the polyether ester carbonate polyol, the ratio of carbonate to ether units, the molecular weight obtained, the polydispersity index (PDI) and the OH number are reported in table 1.

Example 2: Preparation of a Halogen-Containing Polyoxyalkylenecarbonate Polyol by Polymerization of Propylene Oxide, 6.5 Mol % of Epichlorohydrin and CO.SUB.2

[0228] [First Activation Stage, Step (α)]

[0229] A 300 ml pressure reactor fitted with a sparging stirrer was initially charged with a mixture of DMC catalyst (27 mg) and PET-1 (30 g). The reactor was sealed and the pressure in the reactor reduced to 5 mbar for five minutes. The pressure in the reactor was then adjusted to 50 mbar by application of a gentle Ar stream and simultaneous removal of the gas with a pump. The reactor was heated to 130° C. and the mixture was stirred (800 rpm) at 130° C. under reduced pressure (50 mbar) and a gentle Ar stream for 30 minutes. [Second activation stage, step (β)]

[0230] CO.sub.2 was injected to 15 bar, which caused the temperature in the reactor to drop slightly. The temperature was kept at 130° C. by closed-loop control and, during the subsequent steps, the pressure in the reactor was kept at 15 bar by metering in further CO.sub.2. 3.0 g of propylene oxide were metered in with the aid of an HPLC pump (1 ml/min) and the reaction mixture was stirred (800 rpm) for 20 min. The occurrence of a brief increase in evolution of heat in the reactor during this time indicated the activation of the catalyst. Subsequently, two further portions each of 3.0 g of propylene oxide were metered in by means of the HPLC pump (1 ml/min) and the reaction mixture was stirred for 20 min (800 rpm). The occurrence of a brief increase in evolution of heat in the reactor during this time confirmed the activation of the catalyst.

[0231] [Polymerization Stage, Step (γ)]

[0232] After cooling to 105° C., a further 45.0 g of propylene oxide were metered in by means of an HPLC pump (0.91 ml/min) with continued stirring. 10.5 min after commencement of the addition of propylene oxide, 6.0 g of epichlorohydrin were simultaneously metered in by means of an HPLC pump (0.26 ml/min). The reaction mixture was then stirred at 105° C. for a further 1 h. The reaction was stopped by cooling the reactor with ice water, the positive pressure was released and the resulting product analyzed.

[0233] The molar proportion of unconverted propylene oxide (R.sub.PO in mol %) was 1.4%, and that of unconverted epichlorohydrin (R.sub.ECH in mol %) was 1.1 mol %.

[0234] The CO.sub.2 content incorporated in the polyether ester carbonate polyol, the ratio of carbonate to ether units, the molecular weight obtained, the polydispersity index (PDI) and the OH number are reported in table 1.

Example 3 (Comparative): Attempted Preparation of a Halogen-Containing Polyoxyalkylene Polyol by Polymerization of Propylene Oxide and 13.5 Mol % of Epichlorohydrin

[0235] [First Activation Stage, Step (α)]

[0236] A 300 ml pressure reactor fitted with a sparging stirrer was initially charged with a mixture of DMC catalyst (27 mg) and PET-1 (30 g). The reactor was sealed and the pressure in the reactor reduced to 5 mbar for five minutes. The pressure in the reactor was then adjusted to 50 mbar by application of a gentle Ar stream and simultaneous removal of the gas with a pump. The reactor was heated to 130° C. and the mixture was stirred (800 rpm) at 130° C. under reduced pressure (50 mbar) and a gentle Ar stream for 30 minutes.

[0237] [Second Activation Stage, Step (β)]

[0238] A pressure of 2 bar of Ar was established. 3.0 g of propylene oxide were metered in with the aid of an HPLC pump (1 ml/min) and the reaction mixture was stirred (800 rpm) for 20 min. The occurrence of a brief increase in evolution of heat in the reactor during this time indicated the activation of the catalyst. Subsequently, two further portions each of 3.0 g of propylene oxide were metered in by means of the HPLC pump (1 ml/min) and the reaction mixture was stirred for 20 min (800 rpm). The occurrence of a brief increase in evolution of heat in the reactor during this time confirmed the activation of the catalyst.

[0239] [Polymerization Stage, Step (γ)]

[0240] After cooling to 105° C., a further 39.0 g of propylene oxide were metered in by means of an HPLC pump (0.91 ml/min) with continued stirring. 10.5 min after commencement of the addition of propylene oxide, 12.0 g of epichlorohydrin were simultaneously metered in by means of an HPLC pump (0.26 ml/min). The reaction mixture was then stirred at 105° C. for a further 1 h. Ten minutes after the start of the addition of epichlorohydrin, the reaction was stopped by cooling the reactor with ice-water, since no reaction was observed.

Example 4 (Comparative): Attempted Preparation of a Halogen-Containing Polyoxyalkylene Polyol by Polymerization of Epichlorohydrin

[0241] [First Activation Stage, Step (α)]

[0242] A 300 ml pressure reactor fitted with a sparging stirrer was initially charged with a mixture of DMC catalyst (27 mg) and PET-1 (30 g). The reactor was sealed and the pressure in the reactor reduced to 5 mbar for five minutes. The pressure in the reactor was then adjusted to 50 mbar by application of a gentle Ar stream and simultaneous removal of the gas with a pump. The reactor was heated to 130° C. and the mixture was stirred (800 rpm) at 130° C. under reduced pressure (50 mbar) and a gentle Ar stream for 30 minutes.

[0243] [Second Activation Stage, Step (β)]

[0244] Ar was injected to 2 bar. 3.0 g of epichlorohydrin were metered in with the aid of an HPLC pump (1 ml/min) and the reaction mixture was stirred (800 rpm) for 20 min. There was no occurrence of a brief increase in evolution of heat in the reactor during this time that would have indicated activation of the catalyst. Subsequently, two further portions each of 3.0 g of epichlorohydrin were metered in by means of the HPLC pump (1 ml/min) and the reaction mixture was stirred for 20 min (800 rpm). The reaction was stopped by cooling the reactor with ice-water since no reaction was observed.

TABLE-US-00001 TABLE Overview of the results of the preparation of polyoxyalkylenecarbonate polyols CO.sub.2 ECH OH Reaction incorporation incorporation M.sub.n number Example [—] [% by wt.] [mol %] [g/mol] PDI [mg.sub.KOH .Math. g.sup.−1] 1 Terpolymerization of 7.7 5.8 3286 1.21 40.2 PO/13.5 mol % ECH/CO.sub.2 2 Terpolymerization of 9.2 3.2 3324 1.23 46.0 PO/6.5 mol % ECH/CO.sub.2 3 Copolymerization of No product was obtained. (comp.) PO/13.5 mol % ECH 4 Homopolymerization of No product was obtained. (comp.) ECH Comp.: comparative example ECH: epichlorohydrin

[0245] Comparative examples 3-4 demonstrate that, in the case of copolymerization in the presence of epichlorohydrin and in the absence of carbon dioxide, no polymer is formed in the polymerization catalyzed by DMC catalyst. As shown by examples 1-2, the DMC catalyst used, when the monomer mixture contains epichlorohydrin, is active only when carbon dioxide is additionally used as comonomer.

Example 5: Preparation of a Polyurethane Using a Polyoxyalkylenecarbonate Polyol from Example 1 (PEC-1) and HDI Trimer

[0246] PEC-1 (2.0 g), HDI (276 mg) and DBTL (1% by weight, 22.8 mg) were mixed in an aluminum beaker. Subsequently, a sample of the mixture (0.4 g) was used for the measurement on the rheometer and was heated to 40° C. for three hours.

[0247] The NCO index was 1.0.

[0248] The gel time was 17.2 min.

Example 6: Preparation of a Polyurethane Using a Polyoxyalkylenecarbonate Polyol from Example 2 (PEC-2) and HDI Trimer

[0249] PEC-2 (2.0 g), HDI (317 mg) and DBTL (1% by weight, 23.2 mg) were mixed in an aluminum beaker. Subsequently, a sample of the mixture (0.4 g) was used for the measurement on the rheometer and was heated to 60° C. for three hours.

[0250] The NCO index was 1.0. The gel time was 15.3 min.