METHOD FOR PRODUCING POLYETHERESTER POLYOLS

Abstract

A subject of the invention is a method for producing a polyetherester polyol by addition of alkylene oxide and lactone to H-functional starter substance in the presence of a double metal cyanide catalyst, wherein a suspension medium containing no H-functional groups is first initially charged in a reactor, and an H-functional starter substance is subsequently continuously metered in to the reactor during the reaction, and wherein the lactone is a 4-membered cyclic lactone. A further subject is also the polyetherester polyol obtainable according to the method according to the invention, and also polyurethanes which can be produced therefrom.

Claims

1. A process for preparing a polyether ester polyol by addition of alkylene oxide and lactone onto H-functional starter substance in the presence of a double metal cyanide catalyst, comprising: () initially charging a suspension medium containing no H-functional groups in a reactor; and () continuously metering H-functional starter substance into the reactor over the course of the reaction and wherein the lactone is a 4-membered ring lactone.

2. The process as claimed in claim 1, wherein in step () a suspension medium containing no H-functional groups is initially charged in the reactor and no H-functional starter substance is initially charged in the reactor.

3. The process as claimed in claim 1, wherein in step () a suspension medium containing no H-functional groups and additionally a portion of the H-functional starter substance are initially charged in the reactor.

4. The process as claimed in claim 1, wherein in step () a suspension medium containing no H-functional groups is initially charged in the reactor together with DMC catalyst.

5. The process as claimed in claim 4, wherein after step () () a portion of alkylene oxide or a mixture of alkylene oxide and lactone is added to the mixture from step () at a temperature of 90 C. to 150 C. and wherein the addition of the alkylene oxide compound is then interrupted.

6. The process as claimed in claim 5, wherein in step () a mixture of alkylene oxide and lactone is added and the proportion of the lactone is 1% by weight to 80% by weight, based on the total mass of alkylene oxide and lactone metered in step ().

7. The process as claimed in claim 1, wherein in step () H-functional starter substance, alkylene oxide and lactone are metered in continuously.

8. The process as claimed in claim 1, wherein in step () the metered addition of the H-functional starter substance is terminated prior to the addition of the alkylene oxide.

9. The process as claimed in claim 8, wherein in step () a mixture of alkylene oxide and lactone is added and the proportion of the lactone is 1% by weight to 80% by weight, based on the total mass of alkylene oxide and lactone metered in step ().

10. The process as claimed in claim 1, wherein the 4-membered ring lactone comprises at least one of propiolactone, -butyrolactone, -isovalerolactone, -caprolactone, -isocaprolactone, -methyl--valerolactone, and diketene.

11. A polyether ester polyol obtained by the process as claimed in claim 1.

12. A process for producing polyurethanes comprising reacting i) the polyether ester polyol as claimed in claim 11 with ii) a polyisocyanate.

Description

EXAMPLES

[0154] Starting Materials Used

[0155] Propylene glycol (purity >99.5%, Sigma-Aldrich Chemie GmbH)

[0156] Propylene oxide (purity >99.5%, Sigma-Aldrich Chemie GmbH)

[0157] -Propiolactone (97%, Acros Organics BVBA)

[0158] -Butyrolactone (purity 98%, Sigma-Aldrich Chemie GmbH)

[0159] -Caprolactone (purity 97%, Sigma-Aldrich Chemie GmbH)

[0160] The DMC catalyst used in all examples was DMC catalyst prepared according to example 6 in WO 01/80994 A1.

[0161] Description of the Methods:

[0162] Gel permeation chromatography (GPC): Measurements were performed on an Agilent 1200 Series (G1311A Bin Pump, G1313A ALS, G1362A RID), detection by RID; eluent: tetrahydrofuran (GPC grade), flow rate 1.0 ml/min at 40 C.; column temperature; column combination: 2PSS SDV precolumn 100 (5 m), 2PSS SDV 1000 (5 m). Calibration was carried out using Poly(styrene) ReadyCal-Kit low in the range Mp=266-66000 Da from PSS Polymer Standards Service. The measurement recording and evaluation software used was the PSS WinGPC Unity software package.

[0163] .sup.1H NMR

[0164] The composition of the polymer was determined by .sup.1H NMR (Bruker DPX 400, 400 MHz; pulse program zg30, relaxation time D1: 10s, 64 scans). Each sample was dissolved in deuterated chloroform. The relevant resonances in the .sup.1H NMR (based on TMS=0 ppm) and the assignment of the area integrals (A) are as follows: [0165] cyclic propylene carbonate (cPC), solvent, resonance at 4.5 ppm, area integral corresponds to one hydrogen atom; [0166] unreacted monomeric propylene oxide (PO), resonance at 2.4 and 2.8 ppm, each area integral corresponds to one hydrogen atom; [0167] polypropylene oxide (PPO), PO homopolymer, resonances at 1.0 to 1.2 ppm, area integral minus portion of PPL-PPO moiety (1.5*A(PPL-PPO)) corresponds to 3 hydrogen atoms; [0168] polypropiolactone (PPL-PPL), resonance at 4.4 ppm, area integral corresponds to 2 hydrogen atoms; [0169] polypropiolactone (PPL-PPO), resonance at 2.6 ppm, area integral minus 2 hydrogen atoms from the PPL-PPL repeating unit corresponds to 2 hydrogen atoms; [0170] beta-butyrolactone (BL), resonance at 1.6 ppm, area integral minus 3 hydrogen atoms of cPC corresponds to 3 hydrogen atoms; [0171] beta-propiolactone (PL), resonance at 4.28 and 3.54, each area integral corresponds to 2 hydrogen atoms; [0172] polybutyrolactone (PBL-PBL), resonance at 2.4-2.7 ppm, area integral corresponds to 2 hydrogen atoms; [0173] polypropiolactone (PBL-PPO), resonance at 2.4 ppm, area integral corresponds to 2 hydrogen atoms, [0174] epsilon-caprolactone (CL), resonance at 4.3 ppm, area integral corresponds to 2 hydrogen atoms; [0175] polycaprolactone (PCL), resonance at 2.3 ppm, area integral corresponds to 2 hydrogen atoms;

[0176] This gives the following mole fractions (x) for the respective components: [0177] x(cPC)=A (4.5 ppm) [0178] x(PO)=A (2.75 ppm) or A (2.4 ppm) [0179] x(PPO)=A (1.0-1.2 ppm)/3 [0180] x(PPL-PPL)=A(PPL-PPL)/2 [0181] x(PPL-PPO)=A(PPL-PPO)/2 [0182] x(BL)=A(BL)/3 [0183] x(PL)=A(PL)/2 [0184] x(PBL-PBL)=A(PBL-PBL)/2 [0185] x(PBL-PPO)=A(PBL-PPO)/2 [0186] x(CL)=A(CL)/2 [0187] x(PCL)=A(PCL)/2

[0188] The percentage mole fraction is calculated by dividing the mole fraction (x) of the respective component by the sum of the mole fractions present in the sample. The weight fraction is also calculated by multiplying the mole fractions (x) by the accompanying molar masses and dividing by the sum of the weight fractions present. The following molar masses (g/mol) are used for converting the weight fractions: cPC=102, PO and PPO=58, BL=86, PL=72, CL=PCL=114, PPL-PPO=130, PBL-PPO=144, PCL-PPO=172.

Example 1: Preparation of Polyether Ester Polyol with Initial Charging of cPC as the Suspension Medium and Continuous Metered Addition of Propylene Glycol as the H-Functional Starter Substance and -Propiolactone as the Lactone

[0189] Step :

[0190] 100 mg of dried unactivated DMC catalyst were suspended in 50.0 g of 4-methyl-2-oxo-1,3-dioxolane (also referred to hereinafter as cyclic propylene carbonate or cPC) in a 0.3 L pressure reactor fitted with a gas metering unit. The reactor was sealed and inertized by threefold pressurization with 20 bar of N2 and subsequent decompression to 5 bar.

[0191] Step :

[0192] In the reactor at 130 C., 500 rpm and at a supply pressure of 5 bar established with nitrogen, an amount of 10 g of a mixture of -propiolactone (10% by weight) in propylene oxide was added all at once. Onset of the reaction was indicated by a temperature peak (hotspot) and by a pressure drop to the starting pressure. The procedure was carried out twice in total.

[0193] Step :

[0194] After activation, 76.20 g of a mixture of -propiolactone (30% by weight) in propylene oxide at 1 g/min and at the same time 38.05 g of a mixture of propylene glycol (10% by weight) in propylene carbonate at 1 g/min are simultaneously metered into the reactor. Once addition was complete the mixture was stirred at 130 C. until the exothermic reaction had abated and until a constant pressure was reached. The average molecular weight (determined by gel permeation chromatography) is reported in table 1.

Example 2: Preparation of Polyether Ester Polyol with Initial Charging of cPC as the Suspension Medium and Continuous Metered Addition of Propylene Glycol as the H-Functional Starter Substance and -Butyrolactone as the Lactone

[0195] Preparation of the polyether ester polyol was performed as per example 1, but employing a mixture of -butyrolactone (30% by weight) in propylene oxide in step and . The results are reported in table 1.

Example 3 (Comparative): Preparation of Polyether Ester Polyol with Initial Charging of cPC as the Suspension Medium and Continuous Metered Addition of Propylene Glycol as the H-Functional Starter Substance and -Caprolactone as the Lactone

[0196] Preparation of the polyether ester polyol was performed as per example 1, but employing a mixture of -caprolactone (30% by weight) in propylene oxide in step and .

[0197] The results are reported in table 1.

Example 4: Preparation of Polyether Ester Polyol with Initial Charging of cPC as the Suspension Medium and Continuous Metered Addition of Propylene Glycol as the H-Functional Starter Substance and -Propiolactone as the Lactone

[0198] Preparation of the polyether ester polyol was performed as per example 1, but employing a mixture of -propiolactone (5% by weight) in propylene oxide in step and . The results are reported in table 1.

Example 5: Preparation of Polyether Ester Polyol with Initial Charging of cPC as the Suspension Medium and Continuous Metered Addition of Propylene Glycol as the H-Functional Starter Substance and -Propiolactone as the Lactone

[0199] Preparation of the polyether ester polyol was performed as per example 1, but employing a mixture of -propiolactone (10% by weight) in propylene oxide in step and . The results are reported in table 1.

Example 6 (Comparative): Preparation of Polyether Ester Polyol with Initial Charging of Propylene Glycol as the H-Functional Starter Substance and -Propiolactone as the Lactone

[0200] Step :

[0201] 100 mg of dried unactivated DMC catalyst were suspended in 50 g of 4-methyl-2-oxo-1,3-dioxolane (also referred to hereinafter as cyclic propylene carbonate or cPC) and 3.805 g of monopropylene glycol (MPG) in a 0.3 L pressure reactor fitted with a gas metering unit. The reactor was sealed and inertized by threefold pressurization with 20 bar of N.sub.2 and subsequent decompression to 5 bar.

[0202] Step :

[0203] In the reactor at 130 C., 500 rpm and at a supply pressure of 5 bar established with nitrogen, an amount of 10 g of a mixture of -propiolactone (10% by weight) in propylene oxide was added all at once. No reaction such as would be indicated by a temperature increase and a pressure reduction in the reactor was apparent after addition of the propylene oxide. Even addition of a second portion of PO (10 g) did not lead to onset of a reaction. The polyester ether polyol was not producible in this way.

TABLE-US-00001 TABLE 1 Conversion of lactone and molecular weight of the polyether ester polyols Lactone proportion in step ()/ x () [% by X(lactone) M.sub.n (lactone) Example Lactone weight].sup.a) [%] [g/mol] [mol %] 1 - 30/30 100 1845 22.5 propiolactone 2 - 30/30 82 2089 14.5 butyrolactone 3 - 30/30 21 1975 3.0 (comparative) caprolactone 4 - 5/5 100 1945 3.6 propiolactone 5 - 10/10 100 1856 6.9 propiolactone 6 - 30/30 n.d. n.d. n.d. (comparative) propiolactone .sup.a)calculated lactone proportion metered in in step ()/() based on the sum of lactone and alkylene oxide in % by weight in step ()/().

[0204] The results for preparing polyether ester polyols are summarized in table 1. The process according to the invention was used to prepare polyether ester polyols by copolymerization of an alkylene oxide with a lactone by adding 5% by weight (entry 4), 10% by weight (entry 5) and 30% by weight (entry 1) of lactone. The results show that through continuous metered addition of the H-functional starter substance the 4-ring lactones show an improved incorporation rate and conversion rate compared to the prior art and compared to higher lactones such as -caprolactone (comparative example 3). Initial charging of the H-functional starter substance resulted in no polyether ester polyol being obtainable (comparative example 6).