Silicon modified polycarbonate polyol and preparation method thereof

Abstract

The invention discloses a method for preparing silicon-modified polycarbonate polyol. The method comprises the following steps: using trimethyl silyl ester and glycerol as raw materials, carrying out an ester exchange reaction in the presence of a catalyst to produce an intermediate, and then carrying out an ester exchange and polycondensation reaction on the intermediate, a diol and a carbonate to generate the silicon-modified polycarbonate polyol. The prepared silicon-modified polycarbonate polyol has the following benefit effects: the polycarbonate polyol product has a certain flame retardant effect through silicon modification, and due to the presence of a side chain silicon element, the viscosity of the polycarbonate polyol product is reduced, the crystallinity is improved, and the surface performance and touch of downstream products are improved.

Description

Technical Field

[0001] The invention relates to the field of preparation of polyols, and in particular to a silicon-modified polycarbonate polyol and a preparation method thereof. Background Art

[0002] Polycarbonate polyol is a type of polyurethane white material. It is used as the soft segment of polyurethane materials. Its main application areas are synthetic leather / coating and other fields. It is recognized as one of the polyols with the best performance.

[0003] Traditional polycarbonate polyols are synthesized by transesterification using carbonate and small molecule diol as raw materials. The main advantages of this synthesis method are mild reaction conditions and easy adjustment of the synthesis method. Compared with other synthesis methods, it is a pollution-free green preparation process with the characteristics of versatility, economy, simple operation, easy industrialization and environmental protection. As described in invention patent CN201711394969.1, transesterification is used as the synthesis method of polycarbonate polyols.

[0004] However, polycarbonate polyols synthesized by the transesterification method are prone to high product viscosity, which makes downstream applications very inconvenient. In addition, polycarbonate polyols synthesized by diols with an even number of carbon atoms in the prior art also have the problem of crystallization, which further seriously affects downstream applications. In addition, some application fields require it to have flame retardant properties, but there are currently no flame retardant polycarbonate polyol products. Summary of the invention

[0005] In order to improve the performance of polycarbonate polyol, the present invention provides a new silicon-modified polycarbonate polyol and a preparation method thereof. The new process of side chain silicon modification is adopted to make the polycarbonate polyol product have a certain flame retardant effect, reduce the viscosity of the polycarbonate polyol product, improve the crystallinity, and improve the surface performance and touch of downstream products.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A polycarbonate polyol comprising the following components in mass fractions:

[0008] Intermediate 10-40%, preferably 15-35%;

[0009] Small molecule carbonate 30-70%, preferably 35-55%;

[0010] Other glycols 15-40%, preferably 25-55%;

[0011] The total weight of the above components is 100%.

[0012] The intermediate is a compound synthesized using trimethylsilyl ester and glycerol as raw materials under the action of a catalyst.

[0013] Preferably, the mass ratio of trimethylsilyl ester to glycerol is 30-80:20-70.

[0014] Preferably, the catalyst one is one or more of triethylamine, tripropylamine, triethylenediamine, diethylenediamine, tetrabutyl titanate, tetraisopropyl titanate, dibutyltin dilaurate, dibutyltin octoate, p-toluenesulfonic acid, stannous octoate, and hydrotalcite; the amount of catalyst one is 50-150ppm of the total mass of the reactants, preferably 60-80ppm.

[0015] Preferably, the trimethylsilyl acid ester is one or more of methyl trimethylsilyl acetate, ethyl trimethylsilyl acetate, propyl trimethylsilyl acetate, methyl trimethylsilyl propionate, and ethyl trimethylsilyl propionate, among which methyl trimethylsilyl acetate is preferred.

[0016] Preferably, the preparation method of the intermediate is: in a nitrogen atmosphere, trimethylsilyl ester, glycerol and a catalyst are mixed, the temperature is raised to 160-250° C., preferably 200-230° C., at normal pressure, and after keeping the temperature at normal pressure for a period of time, vacuuming is performed to continue the reaction for a period of time before stopping the reaction.

[0017] Preferably, in the method for preparing the intermediate, the reaction time at normal pressure is 3-6 h, preferably 4-5 h.

[0018] Preferably, in the preparation method of the intermediate, the reaction time under vacuum conditions is 5-9 h, preferably 6-8 h, and the vacuum degree conditions are 1-10 kPa, preferably 1-5 kPa.

[0019] In the present invention, the carbonate is one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate and diphenyl carbonate.

[0020] In the present invention, the small molecule diol is selected from one or more of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,3-propylene glycol, 1-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and dipropylene glycol, preferably one or more of 1,4-butanediol and 1,5-pentanediol.

[0021] The present invention also provides a method for preparing the silicon-modified polycarbonate polyol. In a nitrogen environment, an intermediate, a small molecule carbonate, a catalyst II and a small molecule diol are respectively added into a reactor, the temperature is raised to 160-250° C., preferably 200-220° C., at normal pressure, and after being kept at normal pressure for a period of time, vacuuming is performed to continue the reaction, and the reaction is stopped when the hydroxyl value of the product reaches the designed hydroxyl value.

[0022] In the preparation method of the silicon-modified polycarbonate polyol of the present invention, the reaction time at normal pressure is 10-24 hours, preferably 16-18 hours.

[0023] In the preparation method of the silicon-modified polycarbonate polyol of the present invention, the reaction time under vacuum conditions is 3-22 hours, preferably 15-17 hours, and the vacuum degree conditions are 1-10 kPa, preferably 1-4 kPa.

[0024] In the present invention, the catalyst 2 is one or more of tetrabutyl titanate, tetraisopropyl titanate, dibutyl tin dilaurate, stannous octoate, dibutyl tin octoate, trimethylamine, triethylamine, tripropylamine, and p-toluenesulfonic acid, among which tetrabutyl titanate is preferred; the dosage of the catalyst 2 is 30-150ppm, among which 50-130ppm is preferred.

[0025] The silicon-modified polycarbonate polyol prepared by the preparation method of the present invention is applied to the preparation of polyurethane elastomers, and can effectively improve the mechanical properties of the elastomers and enhance the flame retardant properties of the elastomers.

[0026] Preferably, the polyurethane elastomer adopts a traditional elastomer synthesis process, and its formula is: it includes the following raw material components by weight: 25-35 parts of isocyanate, 5-10 parts of chain extender, 50-60 parts of polycarbonate polyol, 2-5 parts of antioxidant and 0-2 parts of catalyst.

[0027] The isocyanate in the elastomer formula of the present invention can be one of MDI, TDI or IDPI; the chain extender is one or more of ethylene glycol, 1,2-propylene glycol, 1,4-butanediol and neopentyl glycol; the antioxidant is mainly a long-chain ester, which can be one or more of antioxidants 245 / 1010 / 1035; the catalyst three is a tertiary amine catalyst, which can be one or more of triethylenediamine, cyclohexylmethyl tertiary amine and pentamethyldialkylenetriamine.

[0028] Compared with the prior art, the present invention has the following beneficial effects: the polycarbonate polyol product has a flame retardant effect through silicon modification, and due to the modification of the side chain silicon element, the apparent performance of the polycarbonate polyol product can be effectively improved, especially reducing the viscosity and improving the crystallinity (all products are in a liquid state), especially the polycarbonate polyol synthesized from the diol with an even number of carbon atoms also has good crystallization performance and can be liquid at room temperature. The lower viscosity and maintaining the liquid state of the product can improve the convenience of use for downstream customers; at the same time, through the application evaluation of the product, it is found that the silicon element modification in the present invention further improves the mechanical properties of downstream products, especially the elongation at break. DETAILED DESCRIPTION

[0029] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0030] The reactants involved in the present invention are all purchased from commercially available pure products unless otherwise specified.

[0031] The test method involved in the present invention is:

[0032] Hydroxyl value: The hydroxyl value of polyester polyol products refers to GBT 12008.5-2009;

[0033] Viscosity: The product viscosity of polyester polyols refers to GBT 12008.7-2010

[0034] Oxygen index: The oxygen index of polyurethane products refers to GBT 10802-2006

[0035] Elongation at break of polyurethane elastomer products refer to GBT 13022-1991

[0036] [Example 1]

[0037] In a 5L stainless steel reactor equipped with a stirrer, a heater, a thermocouple, and a distillation column, under nitrogen protection and stirring, 881g of ethyl trimethylsilyl acetate and 463g of glycerol were added in sequence, and 60ppm of tetrabutyl titanate accounting for the total mass of the above raw materials was added as a catalyst. The reaction was started, and the temperature was raised to 220°C under normal pressure and kept for 5h, and then the vacuum was slowly evacuated to 3kPa, and the vacuum reaction was continued for 6h, and the temperature was lowered and the material was discharged to obtain a silicon-modified polycarbonate polyol intermediate.

[0038] After the reaction of the silicon-modified polycarbonate polyol intermediate was completed, 705g of 1,4-butanediol and 1571g of dimethyl carbonate were added to the reactor to continue the reaction at a temperature of 230°C. After 16 hours of heat preservation, the vacuum was slowly evacuated to 3kPa, and the vacuum reaction was continued for 16 hours. The temperature was lowered and the material was discharged to obtain silicon-modified polycarbonate polyol. The hydroxyl value of the test sample was 67.8mgKOH / g, and the sample appearance was a light yellow viscous liquid with a viscosity of 42670cP at 25°C.

[0039] Preparation of polyurethane elastomer: 8 parts by mass of 1,4-butanediol, 55 parts by mass of polycarbonate polyol, 3 parts by mass of antioxidant 1010 and 0.5 parts by mass of triethylenediamine were mixed to prepare a polyol component, and then 33.5 parts by mass of MDI were added, the temperature was raised to 70-80°C, compression molding was performed, and performance testing was performed after aging for 20 hours.

[0040] According to the test, the elongation at break of the polyurethane elastomer product is 418%, and the oxygen index of the product is 29.3%.

[0041] [Example 2]

[0042] In a 5L stainless steel reactor equipped with a stirrer, a heater, a thermocouple, and a distillation column, under nitrogen protection and stirring, 700g of methyl trimethylsilyl acetate and 368g of glycerol were added in sequence, and 80ppm of tetrabutyl titanate accounting for the total mass of the above raw materials was added as a catalyst. The reaction was started, and the temperature was raised to 200°C under normal pressure and kept for 4h, and then the vacuum was slowly evacuated to 5kPa, and the vacuum reaction was continued for 8h, and the temperature was lowered and the material was discharged to obtain a silicon-modified polycarbonate polyol intermediate.

[0043] After the reaction of the silicon-modified polycarbonate polyol intermediate is completed, 609g of 1,5-hexanediol and 1893g of dimethyl carbonate are added to the reactor to continue the reaction at a reaction temperature of 220°C. After keeping warm for 18 hours, the reaction is slowly evacuated to 2kPa, and the vacuum reaction is continued for 17 hours. The temperature is lowered and the material is discharged to obtain silicon-modified polycarbonate polyol. The hydroxyl value of the test sample is 66.3mgKOH / g, and the sample appearance is a light yellow viscous liquid with a viscosity of 48751cP at 25°C. The polyurethane elastomer is prepared by the same method as in Example 1, and the elongation at break of the elastomer product is 382%, and the oxygen index of the product is 29.1%.

[0044] [Example 3]

[0045] In a 5L stainless steel reactor equipped with a stirrer, a heater, a thermocouple, and a distillation column, under nitrogen protection and stirring, 782g of trimethylsilyl propyl acetate and 373g of glycerol were added in sequence, and 70ppm of stannous octoate as a catalyst was added to the total mass of the above raw materials. The reaction was started, and the temperature was raised to 210°C under normal pressure and kept for 4h, and then the vacuum was slowly evacuated to 3kPa, and the vacuum reaction was continued for 7h, and the temperature was lowered and the material was discharged to obtain a silicon-modified polycarbonate polyol intermediate.

[0046] After the reaction of the silicon-modified polycarbonate polyol intermediate is completed, 678g of 1,4-butanediol and 1923g of dimethyl carbonate are added to the reactor to continue the reaction at a reaction temperature of 200°C. After 17 hours of heat preservation, the reaction is slowly evacuated to 2kPa, and the vacuum reaction is continued for 15 hours. The temperature is lowered and the material is discharged to obtain silicon-modified polycarbonate polyol. The hydroxyl value of the test sample is 65.8mgKOH / g, and the sample appearance is a light yellow viscous liquid with a viscosity of 46673cP at 25°C. The polyurethane elastomer is prepared by the same method as in Example 1, and the elongation at break of the elastomer product is 403%, and the oxygen index of the product is 29.8%.

[0047] [Example 4]

[0048] In a 5L stainless steel reactor equipped with a stirrer, a heater, a thermocouple, and a distillation column, under nitrogen protection and stirring, 791g of ethyl trimethylsilyl acetate and 395g of glycerol were added in sequence, and 70ppm of tetraisopropyl titanate accounting for the total mass of the above raw materials was added as a catalyst. The reaction was started, and the temperature was raised to 210°C under normal pressure and kept for 5h, and then the vacuum was slowly evacuated to 3kPa, and the vacuum reaction was continued for 7h, and the temperature was lowered and the material was discharged to obtain a silicon-modified polycarbonate polyol intermediate.

[0049] After the reaction of the silicon-modified polycarbonate polyol intermediate is completed, 723g of 3-methyl-1,5-pentanediol and 1764g of dimethyl carbonate are added to the reactor to continue the reaction at a reaction temperature of 220°C. After 16 hours of heat preservation, the vacuum is slowly evacuated to 2kPa, and the vacuum reaction is continued for 17 hours. The temperature is lowered and the material is discharged to obtain silicon-modified polycarbonate polyol. The hydroxyl value of the test sample is 66.0mgKOH / g, and the sample appearance is a light yellow viscous liquid with a viscosity of 43659cP at 25°C. The polyurethane elastomer is prepared by the same method as in Example 1, and the elongation at break of the elastomer product is 399%, and the oxygen index of the product is 28.7%.

[0050] [Example 5]

[0051] In a 5L stainless steel reactor equipped with a stirrer, a heater, a thermocouple, and a distillation column, under nitrogen protection and stirring, 848g of ethyl trimethylsilyl propionate and 347g of glycerol were added in sequence, and 70ppm of tetraisopropyl titanate accounting for the total mass of the above raw materials was added as a catalyst. The reaction was started, and the temperature was raised to 220°C under normal pressure and kept for 5h, and then the vacuum was slowly evacuated to 5kPa, and the vacuum reaction was continued for 7h, and the temperature was lowered and the material was discharged to obtain a silicon-modified polycarbonate polyol intermediate.

[0052] After the reaction of the silicon-modified polycarbonate polyol intermediate is completed, 764g of 3-methyl-1,5-pentanediol and 1795g of dimethyl carbonate are added to the reactor to continue the reaction at a reaction temperature of 210°C. After 17 hours of heat preservation, the reaction is slowly evacuated to 2kPa, and the vacuum reaction is continued for 17 hours. The temperature is lowered and the material is discharged to obtain silicon-modified polycarbonate polyol. The hydroxyl value of the test sample is 65.3mgKOH / g, and the sample appearance is a light yellow viscous liquid with a viscosity of 45614cP at 25°C. The polyurethane elastomer is prepared by the same method as in Example 1, and the elongation at break of the elastomer product is 422%, and the oxygen index of the product is 28.9%.

[0053] [Example 6]

[0054] In a 5L stainless steel reactor equipped with a stirrer, a heater, a thermocouple, and a distillation column, under nitrogen protection and stirring, 692g of methyl trimethylsilyl acetate and 347g of glycerol were added in sequence, and 80ppm of tetrabutyl titanate accounting for the total mass of the above raw materials was added as a catalyst. The reaction was started, and the temperature was raised to 220°C under normal pressure and kept for 4h, and then the vacuum was slowly evacuated to 5kPa, and the vacuum reaction was continued for 8h, and the temperature was lowered and the material was discharged to obtain a silicon-modified polycarbonate polyol intermediate.

[0055] After the reaction of the silicon-modified polycarbonate polyol intermediate is completed, 611 g of 1,6-hexanediol and 1822 g of dimethyl carbonate are added to the reactor to continue the reaction at a reaction temperature of 210°C. After keeping warm for 18 hours, the reaction is slowly evacuated to 2 kPa, and the vacuum reaction is continued for 17 hours. The temperature is lowered and the material is discharged to obtain silicon-modified polycarbonate polyol. The hydroxyl value of the test sample is 65.8 mgKOH / g, and the appearance of the sample is a light yellow viscous liquid with a viscosity of 46683 cP at 25°C. The polyurethane elastomer is prepared by the same method as in Example 1, and the oxygen index of the product is 29.3%, and the elongation at break of the elastomer product is 396%.

[0056] [Comparative Example]

[0057] In a 5L stainless steel reactor equipped with a stirrer, a heater, a thermocouple, and a distillation column, 1570g of dimethyl carbonate and 1873g of 1,4-butanediol were added in sequence under nitrogen protection and stirring conditions, and 80ppm of tetrabutyl titanate accounting for the total mass of the above raw materials was added as a catalyst. The reaction was started, and the temperature was raised to 220°C under normal pressure and then kept warm for 17h, and then evacuated to 5kPa, and the reaction was continued for 18h, and the temperature was lowered and the material was discharged to obtain a flame-retardant polycarbonate polyol. After testing, the hydroxyl value was 66.3mg KOH / g, the sample appearance was white solid, and the viscosity at 25°C was 56708cP. The polyurethane elastomer was prepared by the same method as in Example 1, and the product oxygen index was 23.1%, and the elongation at break of the elastomer product was 323%.

[0058] The crystallinity comparison between the embodiment and the comparative example is as follows:

[0059]

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A polycarbonate polyol, characterized in that The following components are included in the mass fraction: Intermediate 10-40%; Small molecule carbonate 30-70%; Small molecule diols 15-40%; Taking the total mass of the above components as 100%; Wherein, the intermediate is a compound synthesized with trimethylsilyl ester and glycerol as raw materials under the action of catalyst one; The mass ratio of the trimethylsilyl ester to glycerol is 30-80:20-70.

2. The polycarbonate polyol according to claim 1, characterized in that The following components are included in the mass fraction: Intermediate 15-35%; Small molecule carbonate 35-55%; Small molecule diols 25-55%; The total weight of the above components is 100%.

3. The polycarbonate polyol according to claim 1, characterized in that The catalyst one is one or more of triethylamine, tripropylamine, triethylenediamine, diethylenediamine, tetrabutyl titanate, tetraisopropyl titanate, dibutyltin dilaurate, dibutyltin octoate, p-toluenesulfonic acid, stannous octoate and hydrotalcite.

4. The polycarbonate polyol according to claim 3, characterized in that The dosage of catalyst 1 is 50-150 ppm based on the total mass of the reactants.

5. The polycarbonate polyol according to claim 4, characterized in that The dosage of catalyst 1 is 60-80 ppm based on the total mass of the reactants.

6. The polycarbonate polyol according to claim 1, characterized in that The trimethylsilyl acid ester is one or more of methyl trimethylsilyl acetate, ethyl trimethylsilyl acetate, propyl trimethylsilyl acetate, methyl trimethylsilyl propionate, and ethyl trimethylsilyl propionate.

7. The polycarbonate polyol according to claim 6, characterized in that The trimethylsilyl ester is methyl trimethylsilyl acetate.

8. The polycarbonate polyol according to claim 1, characterized in that The preparation method of the intermediate is as follows: in a nitrogen atmosphere, trimethylsilyl ester, glycerol and a catalyst are mixed, the temperature is raised to 160-250° C. under normal pressure, the temperature is kept at normal pressure for a period of time, and then vacuum is evacuated to continue the reaction for a period of time before stopping the reaction.

9. The polycarbonate polyol according to claim 8, characterized in that The preparation method of the intermediate is as follows: in a nitrogen atmosphere, trimethylsilyl ester, glycerol and a catalyst are mixed, the temperature is raised to 200-230° C. under normal pressure, the temperature is kept at normal pressure for a period of time, and then vacuum is evacuated to continue the reaction for a period of time before stopping the reaction.

10. The polycarbonate polyol according to claim 8, characterized in that In the preparation method of the intermediate, the reaction time at normal pressure is 3-6 hours.

11. The polycarbonate polyol according to claim 10, characterized in that In the preparation method of the intermediate, the reaction time at normal pressure is 4-5 hours.

12. The polycarbonate polyol according to claim 8, characterized in that In the preparation method of the intermediate, the reaction time under vacuum conditions is 5-9 hours, and the vacuum degree conditions are 1-10 kPa.

13. The polycarbonate polyol according to claim 12, characterized in that In the preparation method of the intermediate, the reaction time under vacuum conditions is 6-8 hours, and the vacuum degree conditions are 1-5 kPa.

14. The polycarbonate polyol according to claim 1, characterized in that The small molecule carbonate is one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, and diphenyl carbonate; The small molecule diol is selected from one or more of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,3-propylene glycol, 1-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and dipropylene glycol.

15. The polycarbonate polyol according to claim 14, characterized in that The small molecule diol is selected from one or more of 1,4-butanediol and 1,5-pentanediol.

16. A method for preparing the polycarbonate polyol according to any one of claims 1 to 15, characterized in that: In a nitrogen environment, the intermediate, small molecule carbonate, small molecule diol and optional catalyst 2 are added to the reactor respectively, and the temperature is raised to 160-250°C under normal pressure. After maintaining the temperature and pressure for a period of time, the reaction is continued by vacuuming until the hydroxyl value of the product reaches the designed hydroxyl value and then the reaction is stopped.

17. The preparation method according to claim 16, characterized in that: In a nitrogen environment, the intermediate, small molecule carbonate, small molecule diol and optional catalyst 2 are added to the reactor respectively, and the temperature is raised to 200-220°C under normal pressure. After maintaining the temperature and pressure for a period of time, the reaction is continued by vacuuming until the hydroxyl value of the product reaches the designed hydroxyl value and then the reaction is stopped.

18. The preparation method according to claim 16, characterized in that: The reaction time at normal pressure is 10-24h.

19. The preparation method according to claim 18, characterized in that: The reaction time at normal pressure is 16-18h.

20. The preparation method according to claim 16, characterized in that: The reaction time under vacuum conditions is 3-22h, and the vacuum degree conditions are 1-10kPa.

21. The preparation method according to claim 20, characterized in that: The reaction time under vacuum conditions is 15-17h, and the vacuum degree conditions are 1-4kPa.

22. The preparation method according to claim 16, characterized in that: The second catalyst is one or more of tetrabutyl titanate, tetraisopropyl titanate, dibutyltin dilaurate, stannous octoate, dibutyltin octoate, trimethylamine, triethylamine, tripropylamine, and p-toluenesulfonic acid.

23. The preparation method according to claim 22, characterized in that: The second catalyst is tetrabutyl titanate.

24. The preparation method according to claim 16, characterized in that: The dosage of catalyst 2 is 0-150ppm.

25. The preparation method according to claim 24, characterized in that: The dosage of catalyst 2 is 30-130ppm.

26. Use of the polycarbonate polyol according to any one of claims 1 to 15 or the polycarbonate polyol prepared by the preparation method according to any one of claims 16 to 25 in the field of preparing polyurethane elastomers.

27. The use according to claim 26, wherein the polyurethane elastomer comprises the following raw material components in parts by weight: 25-35 parts of isocyanate, 5-10 parts of chain extender, 50-60 parts of polycarbonate polyol, 2-5 parts of antioxidant and 0-2 parts of catalyst.

28. The use according to claim 27, wherein the isocyanate is one of MDI, TDI or IDPI; and the chain extender is one or more of ethylene glycol, 1,2-propylene glycol, 1,4-butanediol and neopentyl glycol.

29. The use according to claim 27, characterized in that The antioxidant is antioxidant 245, antioxidant 1010 or antioxidant 1035.

30. The use according to claim 27, characterized in that Catalyst three is a tertiary amine catalyst.

31. The use according to claim 30, characterized in that Catalyst three is one or more of triethylenediamine, cyclohexylmethyl tertiary amine, pentamethyldialkylenetriamine.

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