KR100562152B1 - Process for producing polytetrahydrofuran - Google Patents

Abstract

In the present invention, a tetrahydrofuran (THF) is polymerized to prepare polytetrahydrofuran (PTHF), and after the manganese oxide compound or chromium oxide compound, or a mixture thereof, which is a catalyst precursor, is supported on an oxide support, 400 ° C. to It relates to a method for producing polytetrahydrofuran having a molecular weight of 200 to 5000 in high yield using a catalyst prepared by firing at a temperature in the range of 1200 ° C.

Description

Process for preparing polytetrahydrofuran

The present invention relates to a method of preparing high molecular weight polytetrahydrofuran (hereinafter abbreviated as "PTHF") by reacting tetrahydrofuran (THF) with a catalyst, more specifically manganese oxide compound or chromium oxide compound, Or it relates to a method for producing a polytetrahydrofuran having a molecular weight of 200 to 5000 using a catalyst prepared by supporting a mixture of these, such as a catalyst precursor on an oxidation support, and then calcining at an appropriate temperature.

PTHF, also called polyoxybutylene glycol, is used as an intermediate in the preparation of polyurethanes, polyesters and polyamide elastomers used as diol components.

PTHF is used as a component of the soft segment of these polymers because the polymer containing such PTHF is soft in its chain and exhibits ductile properties.

It is also used as a plasticizer, impregnant, monomer, emulsifier, and dispersion aid, and is an industrially useful polymer that can be used as a solvent, a pressure fluid, and the like used for removing ink in waste paper recycling, and their use continues to increase.

Polymerization of tetrahydrofuran (THF) by oxonium ion catalysis is known by the results of a basic experiment (H. Mewerwein et al., Angew Chemie 72, (1960), 927), Dreyfuss et al. It is also described in a research paper (eg, "Polytetrahydrofuran" by P. Dreyfuss, Gordon and Breach Sc. Publishers, New York, London, Paris 1982).

A previously prepared catalyst participates as a catalyst of this reaction or the catalyst is prepared in the same system as the reaction mixture.

Strong Lewis acids and strong Bronsted acids can be used as catalysts, with the help of reactive compounds called accelerators which produce oxonium ions which initiate the polymerization of tetrahydrofuran.

Strong Lewis acids used include boron trichloride, tin tetrachloride, antimony pentachloride, phosphorus fluoride, and the like, and strong Bronsted acids include perchloric acid, fluorosulfonic acid, chlorosulfonic acid, iodic acid, and ferric tetrachloride.

In addition, as an accelerator, alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and the like may be used, and orthoesters, acetals, benzyl halides, acid chlorides, carboxylic anhydrides, sulfonic acid halides, and the like may be used.

However, these catalyst systems are highly acidic and cause corrosive and discoloration of the PTHF produced, so only a few of them are used industrially.

In US Pat. No. 3,358,042, a THF polymerization reaction is carried out using two molecules of fluorosulfonic acid as a catalyst to prepare PTHF.

In addition, US Pat. No. 3,712,930 uses a fuming sulfuric acid as a catalyst to perform THF polymerization.

The disadvantage of these methods is that they cannot recover the fluorosulfonic acid used in the polymerization, and by-products such as sulfuric acid and hydrofluoric acid are very harmful and strong acids, which can cause environmental problems.

The PTHF produced in this way also contains a certain amount of fluorine end groups.

Examples of using zeolites in the preparation of PTHF are described in US Pat. No. 4,303,782.

PTHF obtained by this method is unsuitable for commercial use because it has a very large number average molecular weight of 250,000 to 500,000.

This method also has the disadvantage that the reaction yield is very low, resulting in a PTHF conversion of 4% in 24 hours.

U.S. Patent No. 5,149,862 uses an acidic heterogeneous polymerization catalyst prepared by doping sulfate with zirconium dioxide.

This method has the disadvantage that the reaction proceeds very slowly in the absence of an accelerator and yields only 6% for 19 hours. A mixture of acetic acid and acetic anhydride is added to the reaction medium to promote polymerization.

However, PTHF diacetate prepared by this method has a disadvantage that it must be converted to PTHF through a terminal hydrolysis reaction.

U.S. Patent No. 4,163,115 also discloses esters of PTHF by polymerizing THF using a polymerization catalyst comprising a sulfonic acid group or a polymerization catalyst comprising a carboxylic acid such as acetic acid in a solvent containing an acylium ion precursor such as acetic anhydride. The method of making is described.

The ratio of carboxylic acid and acylium ion precursor is related to the molecular weight of the ester produced.

Soft segments of urethane elastomers using PTHF easily crystallize at low temperatures, causing problems in physical properties at low temperatures that are insufficient to recover after being stretched under tension.

In order to solve this problem, a copolymer of polyether glycol and a cyclic ether such as THF has been studied instead of the conventional PTHF homopolymerization, but the ring-opening polymerization of the cyclic ether or the difficulty of synthesizing the cyclic ether, etc. For this reason, the type of copolymer is limited and satisfactory results cannot be obtained.

In general, a method of obtaining a copolymer having a hydroxyl group in the sock end at the time by copolymerizing THF having low ring-opening polymerizability and a polyhydric alcohol coexist is not known.

An example of co-opening epichlorohydrin in THF is known from Japanese Patent Publication No. 1973-32220, but the polyhydric alcohol added in this method is only bound to one end of the polymer because it is thought to act only at the start of the reaction. do.

In addition, US Pat. No. 4,568,775 and US Pat. No. 4,658,065 describe examples of using heteropolyacids as catalysts in the preparation of PTHF.

Heteropoly acids have the disadvantage that the degree of dissolution in the polymer is different depending on the number of water molecules coordinated to the heteropoly acid, and they are also susceptible to discoloration while forming a mixture with the polymer.

This method also does not readily separate heteropolyacids mixed with polymers.

To this end, a method of precipitating a heteropoly acid mixed with a polymer by a method such as hydrocarbon addition is also devised.

PTHF manufacturing methods as described above had a common disadvantage of low polymerization yield, and in order to eliminate such disadvantages, a compound known as a reaction accelerator was added and then prepared in a multi-step treatment.

The present invention is to provide a method that can be produced in a high polymerization yield in the production of polytetrahydrofuran (PTHF) by reacting tetrahydrofuran (THF) with a catalyst.

According to the present invention, in preparing polytetrahydrofuran (PTHF) by polymerizing tetrahydrofuran (THF), after supporting a manganese oxide compound or a chromium oxide compound, or a mixture thereof, which is a catalyst precursor on an oxide support, 400 to It relates to a method for producing a polytetrahydrofuran having a molecular weight of 200 to 5000 by reacting a catalyst prepared by firing at a temperature in the range of 1200 ℃ with THF.

Hereinafter, the present invention will be described in detail.

The polymerization catalyst of the present invention is prepared by supporting manganese oxide or chromium oxide or a mixture thereof on the support on an oxide support material.

In addition, it may be used as a catalyst by additionally doping a sulfur compound or a phosphorus compound.

Catalyst precursors such as manganese oxide or chromium oxide or a mixture thereof are supported on the support material and then calcined at 400 ° C. to 1200 ° C. to be converted into the catalyst of the present invention.

Examples of the oxide support include zirconium dioxide, titanium dioxide, hafnium oxide, yttrium oxide, iron oxide (III), aluminum oxide, tin oxide (IV), silicon dioxide, zinc oxide or a mixture of these oxides.

Preferred of these is zirconium dioxide.

The weight ratio of the catalytic precursor to the support is 0.1 to 50% by weight, preferably 1 to 30% by weight, based on the weight of manganese trioxide (MnO ₃ ) or chromium trioxide (CrO ₃ ), More preferably 5 to 20% by weight.

Outside the above range, the activity of the catalyst is reduced.

In all cases the catalyst used in this invention may be doped with an oxygen containing compound comprising sulfur or phosphorus.

The amount doped is 0.01 to 5% by weight, preferably 0.5 to 3% by weight, more preferably 0.1 to 1% by weight, based on the total weight of the catalyst supported on the basis of sulfur (S) and phosphorus (P).

Also in the case of doping, if it is out of the said range, the activity of the catalyst containing sulfur (S) and phosphorus (P) will decrease, and it is not suitable as a catalyst of this invention.

It is more effective to start with hydroxide as a support for the polymerization catalyst used in the present invention.

Precursor compounds of manganese oxide or chromium oxide containing catalytically activated oxygen may be coated on the hydroxide of the support component by impregnation.

The precursor compound of manganese oxide or chromium oxide is coated on the hydroxide of the above component by impregnating a water-soluble salt of manganese acid prepared by dissolving manganese trioxide in an aqueous ammonia solution and a water-soluble salt of chromic acid prepared by dissolving chromium trioxide in an aqueous ammonia solution. .

The hydroxide impregnated in this way is usually dried at an atmospheric pressure or reduced pressure at a temperature of 80 to 400 ℃, preferably 100 to 150 ℃.

This impregnated and dried catalyst precursor is converted to the final catalyst by firing in air and at temperatures ranging from 400 to 1200 ° C., preferably from 500 to 1000 ° C., more preferably from 600 to 800 ° C.

Outside the above temperature range, the activity of the catalyst, which has a deep relationship with the yield of the product, decreases, and consequently, the PTHF yield decreases.

The hydroxide used as starting material in the calcination process is converted into an oxidizing support material, and the precursor compound of the manganese or chromium compound containing oxygen, which is made by the above method and coated on the support material by impregnation, is catalytically activated. Converted to the compound.

The firing temperature in this process is deeply related to the yield of the THF polymerization process.

Firing at high temperatures is important for obtaining high conversions.

When firing at temperatures lower than those described above, the desired high yields are difficult to obtain and are uneconomical and of low commercial value.

As described above, in addition to a compound in which manganese oxide or chromium oxide containing catalytically activated oxygen is impregnated on a support, a sulfate group which is a compound containing sulfur and a phosphate group which is a compound containing phosphorus can be used as a catalyst. have.

The preparation of such catalysts takes place in a similar manner as described for catalysts comprising manganese oxides or chromium oxides and the compounds comprising sulfur and phosphorus consist in further impregnation of the hydroxides of the above components prepared in a similar manner.

The process of coating the compound containing sulfur or phosphorus on the support occurs simultaneously with or after the process of coating the manganese and chromium components.

Compounds containing sulfur and phosphorus are advantageous compounds comprising sulfate groups and phosphate groups.

For example, it is prepared by impregnating a hydroxide of the above components in an aqueous solution of sulfuric acid or phosphoric acid.

In particular, catalysts prepared by impregnation with an aqueous solution of sulfate or phosphate are advantageous, and ammonium sulfate or ammonium phosphate is preferred as the sulfate and phosphate used.

When using telogen water and the catalyst described in the present invention, high yields of PTHF can be obtained in one step reaction.

Since water used as telogen can terminate the polymerization reaction, the average molecular weight of the PTHF to be prepared can be controlled by adjusting the amount of water used.

When the concentration of water is high in the reaction solution, a low molecular weight PTHF may be obtained. On the contrary, when the concentration of water in the reaction solution is low, a high molecular weight PTHF may be prepared.

PTHF having a molecular weight of 200 to 10000 can be prepared according to the amount of water added to the reaction solution.

The process of the present invention can be advantageously used for the preparation of PTHF, preferably having a molecular weight of 200 to 5000, more preferably of 1000 to 3000.

To this end, telogen is added in an amount of 0.01 to 20 mol%, preferably 0.1 to 10 mol%, more preferably 0.5 to 5 mol%, of the amount of THF used for preparing PTHF.

The polymerization is usually carried out at atmospheric temperature at a temperature of 20 to 80 ° C., preferably 40 to 60 ° C.

The reaction time is usually from 1 hour to 30 hours and preferably from 3 hours to 20 hours, depending on the amount added to the reaction.

The amount of catalyst added for the polymerization is suitably added in an amount of 20 to 80% by weight, preferably 30 to 60% by weight, based on the weight of THF added to the reaction.

Example 1

The catalyst was prepared by adding 130 g of manganese acid (H ₂ MnO ₄ ) to 1000 g of ammonia solution at 25% concentration, stirring at room temperature and atmospheric pressure for 2 hours, and adding 850 g of zirconium hydroxide to the solution.

The mixture was stirred for 2 hours and then dried at 120 ° C for 24 hours under atmospheric pressure.

The catalyst precursor produced after drying was powdered and calcined at 600 ° C. for 6 hours.

500 g of the catalyst prepared as described above was added to a THF 500 g solution having a telogen water content of 400 ppm, and stirred at 60 ° C. for 6 hours at atmospheric pressure.

After the reaction, the catalyst was precipitated, and the upper layer solution was taken and dried to obtain 290 g of PTHF having a number average molecular weight of 2,800.

Comparative Example 1

500 g of the catalyst precursor obtained in the same manner as described in Example 1 was powdered and then calcined at 350 ° C. for 6 hours.

The reaction was carried out under the same conditions as in Example 1.

As a result, 24 g of PTHF having a number average molecular weight of 1,300 was obtained.

Example 2

500 g of the catalyst obtained in the same manner as described in Example 1 was added to a THF 500 g solution having a telogen water content of 1,000 ppm, and the reaction was performed in the same manner as in Example 1.

As a result, 220 g of PTHF having a number average molecular weight of 2,100 was obtained.

Example 3

A catalyst prepared in the same manner as in Example 1 was added to a THF solution under the same conditions as in Example 1.

The reaction was carried out under the same conditions as in Example 1 except that the reaction time was 10 hours.

As a result, 330 g of PTHF having a number average molecular weight of 3,700 was obtained.

Example 4

A catalyst was prepared in the same manner as in Example 1 except that the firing temperature of the catalyst precursor was 800 ° C.

500 g of the catalyst thus prepared was added to the same solution as in Example 1 to carry out the reaction in the same manner.

As a result, 310 g of PTHF having a number average molecular weight of 3,500 was obtained.

Example 5

The catalyst was prepared by adding 130 g of chromic acid (H ₂ CrO ₄ ) to 1,000 g of ammonia solution at 25% concentration, stirring the mixture at room temperature and atmospheric pressure for 2 hours, and adding 850 g of zirconium hydroxide to the solution.

The mixture was stirred for 2 hours and then dried at 120 ° C for 24 hours under atmospheric pressure.

The catalyst precursor produced after drying was powdered and calcined at 600 ° C. for 6 hours.

500 g of the prepared catalyst was added to a THF 500 g solution having a telogen water content of 400 ppm, and stirred at 60 ° C. for 6 hours at atmospheric pressure.

After the reaction, the catalyst was precipitated, and the upper layer solution was taken and dried to obtain 130 g of PTHF having a number average molecular weight of 1,500.

Comparative Example 2

500 g of the catalyst precursor obtained in the same manner as described in Example 5 was powdered and then calcined at 350 ° C. for 6 hours.

The reaction was carried out under the same conditions as in Example 5.

As a result, 15 g of PTHF having a number average molecular weight of 1100 was obtained.

Example 6

500 g of the catalyst obtained in the same manner as described in Example 5 was added to a THF 500 g solution having a telogen water content of 800 ppm, and the reaction was carried out in the same manner as in Example 5.

As a result, 110 g of PTHF having a number average molecular weight of 1,400 was obtained.

Example 7

A catalyst prepared in the same manner as in Example 5 was added to a THF solution under the same conditions as in Example 5.

The reaction was carried out under the same conditions as in Example 5 except that the reaction time was 10 hours.

As a result, 260 g of PTHF having a number average molecular weight of 2,400 was obtained.

Example 8

A catalyst was prepared in the same manner as in Example 5 except that the firing temperature of the catalyst precursor was 800 ° C.

500 g of the catalyst thus prepared was added to the same solution as in Example 5, and the reaction was performed in the same manner.

As a result, 240 g of PTHF having a number average molecular weight of 2,800 was obtained.

Example 9

130 g of manganese acid (H ₂ MnO ₄ ) was added to 1,000 g of ammonia solution at 25% concentration, and then mixed with 200 g of sulfuric acid (H ₂ SO ₄ ) at 1 N concentration, followed by stirring at atmospheric pressure for 2 hours.

850 g of zirconium hydroxide was added to the mixture, followed by further stirring for 2 hours, followed by drying at 120 ° C. for 24 hours.

The precursor of the catalyst produced after drying was powdered and calcined at 800 ° C. for 5 hours.

500 g of the catalyst thus prepared was subjected to reaction under the same experimental conditions as in Example 1.

As a result, 310 g of PTHF having a number average molecular weight of 3,300 was obtained.

Example 10

A catalyst was prepared in the same manner as in Example 9, except that phosphoric acid (H ₃ PO ₄ ) of 1N concentration was added instead of sulfuric acid.

The reaction was carried out under the same conditions as in Example 9 using the prepared catalyst to obtain 230 g of PTHF having a number average molecular weight of 2,900.

Example 11

130 g of chromic acid (H ₂ CrO ₄ ) was added to 1,000 g of ammonia solution at 25% concentration, and then mixed with 200 g of sulfuric acid (H ₂ SO ₄ ) at 1 N concentration, followed by stirring at atmospheric pressure for 2 hours.

850 g of zirconium hydroxide was added to the mixture, followed by further stirring for 2 hours, followed by drying at 120 ° C. for 24 hours.

The precursor of the catalyst produced after drying was powdered and calcined at 800 ° C. for 5 hours.

500 g of the catalyst thus prepared was allowed to react under the same conditions as in Example 1.

As a result, 140 g of PTHF having a number average molecular weight of 1,700 was obtained.

Example 12

A catalyst was prepared in the same manner as in Example 11, except that 1N phosphoric acid (H ₃ PO ₄ ) was added instead of sulfuric acid.

The reaction was carried out under the same conditions as in Example 11 using the prepared catalyst to obtain 120 g of PTHF having a number average molecular weight of 1,500.

As can be seen from Table 1, it can be seen that the yield is reduced when it is out of the firing temperature range of the present invention.

The present invention can produce PTHF in high yield because water is telogen and the THF is polymerized using a polymerization catalyst prepared by a specific method.

In addition, the present invention can prepare a PTHF having a molecular weight of 200 to 5000 by adjusting the amount of water used, and can also easily prepare a molecular weight of PTHF.

In addition, since the present invention uses water as the telogen, there is also an advantage in that PTHF may be prepared in one step.

Claims (5)

A method for producing polytetrahydrofuran (PTHF) characterized in that the tetrahydrofuran (THF) is polymerized using telogen water in the presence of a catalyst prepared by the following method.                             Below "Prepared by supporting a catalyst precursor selected from manganese oxide, chromium oxide, or a mixture thereof on an oxide support material, followed by drying and firing at 400 to 1,200 占 폚. The method of claim 1, wherein the oxide support is selected from zirconium dioxide, titanium dioxide, hafnium oxide, yttrium oxide, iron (III) oxide, aluminum oxide, tin oxide (IV), silicon dioxide, zinc oxide or a mixture of these oxides The manufacturing method of polytetrahydrofuran. The method for producing polytetrahydrofuran according to claim 2, wherein a catalyst obtained by further doping sulfur (S) or phosphorus (P) to the catalyst is used. The method according to claim 1, wherein the weight ratio of the catalyst precursor to the support for the oxidation of polytetrahydrofuran characterized in that it contains 0.1 to 50% by weight of manganese or chromium relative to the total weight of the catalyst based on the weight of the manganese trioxide or chromium trioxide. Way. The method for producing polytetrahydrofuran according to claim 3, wherein a catalyst doped with 0.01 to 5% by weight of a sulfur compound or a phosphorus compound based on sulfur and phosphorus relative to the total weight of the catalyst is used.