JPS58134120A - Preparation of polytetramethylene glycol - Google Patents

Abstract

PURPOSE:To obtain the titled polymer having a stable high quality without carrying out the acidic hydrolysis, by polymerizing tetrahydrofuran in the presence of a catalyst consisting of sulfuric acid, etc., and treating the resultant intermediate polymer containing sulfuric ester groups with a solid catalyst. CONSTITUTION:Tetrahydrofuran (THF) is polymerized in the presence of a catalyst consisting essentially of sulfuric acid and/or a derivative thereof, e.g. fluorosulfuric acid, as an essential component in an amount of 1-20wt% expressed in terms of SO3 based on THF, and the resultant intermediate polymer containing sulfuric ester groups is then treated with 0.05-20wt%, based on the intermediate polymer, solid catalyst, e.g. silica, to convert the sulfuric ester groups into the hydroxyl groups.

Description

Detailed Description of the Invention The present invention relates to polytetramethylene glycol (hereinafter referred to as PTMG).
That means there is power. ) related to the manufacturing method.

More specifically, the present invention relates to a method for producing polytetramethylene glycol that does not require acidic hydrolysis and can produce stable, high-quality polytetramethylene glycol.

PTMG has been attracting attention in recent years as a glycol component for polyurethane, polyester, etc., and its demand is increasing year by year. PTMG is usually produced by polymerizing tetrahydrofuran (hereinafter sometimes referred to as THF). Traditionally, polymerization catalysts containing sulfuric acids or sulfuric acid derivatives have been commonly used in the production of PTMG due to their high reactivity and high yield of polymers. A method for producing PTMG having hydroxyl groups at both ends by polymerizing THF in the presence of this catalyst and heating and hydrolyzing the polymer having sulfuric ester groups at the terminals produced as an intermediate compound under a strong acid column. was there.

However, in this method, PTMG depolymerizes at high temperatures under a strong acid column, and hydrogen fluoride is generated in certain catalyst systems (for example, systems using fluorosulfuric acid, hydrogen heptadide, or hydrogen fluoride). Usual acid-resistant materials (e.g. glass lining, lead lining.

Hastelloy steel, stainless steel, etc.), so it requires fluororesin, which is difficult to process, and precious metals, which are expensive.

In addition, in addition to sulfuric acids or their derivatives, when carboxylic acid anhydrides and/or carboxylic acid halides are used as cocatalysts, a middle cylinder polymer having an acyloxy group in addition to the ζ ester group is formed. The acidic hydrolysis process that converts sulfate ester groups into hydroxyl groups and the alkaline process that converts acyloxy groups into hydroxyl groups are contaminating, require separate corrosion-resistant equipment, and increase the amount of acidic and alkaline waste liquids. There were drawbacks.

Under these circumstances, the present inventors have intensively studied an industrially advantageous method for producing PTMG without performing acidic hydrolysis, and as a result, they have arrived at Invention C. That is, in the present invention, a sulfate group-containing intermediate polymer obtained by polymerizing tetrahydrofuran using a catalyst containing sulfuric acids and/or sulfuric acid derivatives as an essential component is treated with a solid catalyst to convert the sulfate groups into hydroxyl groups. This is a method for producing polytetramethylene glycol.

In the present invention - a catalyst containing a sulfuric acid and/or a sulfuric acid derivative as an essential component, examples of the sulfuric acid include sulfuric acid, sulfuric acid, sulfuric acid, and sulfuric anhydride.

The sulfuric acid is □′, industrial concentrated sulfuric acid (JIS K 18
02-1956) For example, 9 leaves, 95%, ss
% products are given, and 9th sister products are preferred.

As fuming sulfuric acid, there is a wide range of concentrations (1 to 99%), but industrially (JIS K 180B-6
6) 28% and 28% products are available.

Examples of sulfuric anhydride include α-type, β-type, and γ-type, and γ-type (melting point: 16.8° C.) is preferable in terms of melting point.

Sulfuric acid derivatives include fluorosulfuric acid and chlorosulfuric acid.

Examples include trifluoromethanesulfonic acid and a mixture of two or more thereof.

Sulfuric acids and sulfuric acid derivatives may be used alone or together with a cocatalyst. Examples of cocatalysts include carboxylic anhydrides [acetic anhydride, propionic anhydride, butyric anhydride, trichloroacetic anhydride,
, trifluoroacetic anhydride, benzoic anhydride, male anhydride, inic acid, phthalic anhydride, etc.), carboxylic acid halides (acetic acid chloride, benzoic acid chloride,
phosgene, etc.), hydrogen fluoride, hydrogen nitride salts (sodium fluoride, potassium fluoride, ammonium fluoride, acidic sodium fluoride, acidic potassium fluoride, acidic calcium fluoride, acidic ammonium fluoride, etc.) ) and mixtures of two or more of these.

Specific examples of catalysts containing sulfuric acids and/or sulfuric acid derivatives as essential components include the following catalysts.

[1] Catalyst requiring sulfuric acid ■Oleum group; oleum 1 oleum - acetic anhydride hydrogen fluoride (salt) - acetic anhydride 1 oleum - hydrogen fluoride (salt) - propylene anhydride, ionic acid 1 fuming Sulfuric acid - boriphosphoric acid, etc.■ Sulfuric anhydride group; sulfuric anhydride, sulfuric anhydride - acetic anhydride.

Anhydrous sulfuric acid-hydrogen fluoride (salt), anhydrous sulfuric acid-hydrogen fluoride (salt)
Salt) - acetic anhydride, etc. Sulfuric acid group: sulfuric acid - acetic anhydride, sulfuric acid - perchloric acid, acetic anhydride, etc. [2] Catalysts that require sulfuric acid derivatives Fluorosulfuric acid, Fluorosulfuric acid - Acetic acid, Fluorosulfuric acid - Adipic acid, Fluorosulfuric acid -acetic anhydride.

Fluorosulfuric acid-benzoic acid, etc. [8] Fluorosulfuric acid-sulfuric acid, fluorosulfuric acid-fuming sulfuric acid, catalysts that require sulfuric acids and sulfuric acid derivatives.

When THF such as trifluoromethanesulfuric acid-oleum is polymerized in the presence of the above-mentioned catalyst, the amount of the catalyst varies depending on the type and combination of catalysts and cannot be determined, but generally sulfuric acids and/or sulfuric acid derivatives are used. The amount of THF
When using a co-catalyst, the amount of carboxylic acid anhydride is 1-50% by weight based on the weight of THF.
Weight%, hydrogen fluoride (salt): 0.1 to 5 in terms of hydrogen fluoride
Weight%.

As for the method of adding the catalyst, when it is used alone, it may be added and mixed with the mother THF. However, when adding high concentration (60% or more) oleum or sulfuric anhydride.

Ethi L/ for the purpose of preventing THF coloring or tar formation.
Preferably, a diluent such as carbon cyclolide (EDC) is used. The temperature at which the catalyst is added is usually 40°C or lower, preferably 10°C or lower.If there are two or more components, they may be added separately or mixed in advance. , the former method is preferred.

Moreover, the order of addition is not particularly limited. Polymerization conditions vary slightly depending on the catalyst, but may be the same as conventional ones, and the temperature is usually -
20 to 40°C, preferably 0 to 10°C, and the time is usually 0.
The time is 5 to 10 hours, preferably 2 to 5 hours.

The polymerization is terminated using an alkaline aqueous solution such that the pH becomes 4 or higher, preferably 7 or higher. It is possible to stop using only water, but in this case, it is necessary to heat the water before recovering THF.
When H is 4 or more, preferably 7 or more with an alkali, the terminals of the polymerized product are sulfuric ester groups and hydroxyl groups, and in this case, after the polymerization is terminated, unreacted THF is removed by distillation and recovered. The aqueous layer containing Japanese salt may be separated by standing and discarded.

Further, when a carboxylic acid anhydride and a carboxylic acid halide are used together as a cocatalyst, a sulfuric acid ester group, a hydroxyl group, and an acyloki'741ζ are formed. In this case, it is the same as above (after termination of polymerization, THF recovery, the aqueous layer containing the neutralized salt may be separated and discarded (however, in this case, after the solid catalyst treatment described below,
It is necessary to perform alkaline hydrolysis. ) After THF recovery, the acyloxy groups may be converted into hydroxyl groups by performing alkaline hydrolysis as is or by adding an alkali.

The method for carrying out the alkaline hydrolysis may be the same as conventional methods, for example, the amount of acyloxy group or more, preferably 1.1
It is sufficient to add an aqueous alkali solution (usually 20 to 50% by weight) of ~1.5 times the equivalent and stir the mixture usually at 80 to 150[deg.] for 2 to 6 hours, preferably at 110 to 180[deg.] for 8 to 4 hours. At this time, a solvent such as benzene, toluene, xylene, isopropyl alcohol, butyl alcohol, etc. may be used in combination.

Should stirring be stopped after hydrolysis?

Alternatively, if centrifugation or the like is performed, the oil layer will be separated into an oil layer and an aqueous layer, so the oil layer can be taken out and the aqueous layer can be removed.

In this way, typically 60 to 80% of the THF used can be converted into intermediate polymers.

The content of sulfate ester groups (in terms of S03) of the intermediate polymer having 1,000 sulfuric acid ester groups thus obtained is usually several hundred to several ppm. The intermediate polymer is then treated with a solid catalyst. Examples of the solid catalyst include the following compounds and mixtures of two or more thereof.

(1) Silicas anhydrous silicic acid, hydrated silicic acid, anhydrous magnesium silicate, hydrated magnesium silicate (e.g. talc), silicic acid power,
Lucium, 2Mg0'6SiOix ・H2O (Kizi-Ward 600. Kyowa Chemical Co., Ltd. product), etc. [Yam] Aluminas Anhydrous alumina, Aj? 203'x -H2O (Keyword 200) 2.5Mg0*A6203 ・x -H
2O (Kyoward 800) etc. (1) Silica-aluminas 5 (02 (18%)-alWoa (87%) (silica alumina, Catalysts Kasei Kyowa), 5i02 (89%)-A
120a (4.5%) (Radiolite 900. Catalyst Kasei Kyowa) 2 Synthetic silicates (e.g. Tsurmos A, Shiraishi Kogyo Kyowa), clays (e.g. kaolin, sericite, pyrophyllite, montmorillonite, etc.), mica powder 1 Synthetic zeolite (molecular sieve) etc. (IV) Among activated carbon stiffness, preferred are silicas and silica
Among the aluminas, particularly preferred are 5i02 (1
8%)-A1203 (87%) and 2Mg0 6S
i 02 xH2O. The shape of the solid catalyst is a fine powder (granules) (4) Although it can vary depending on the type of solid catalyst, it is usually 0.05 to 20% by weight of the intermediate polymer containing a certain sulfate ester group, and preferably 0.5~
It is 5% by weight. If the amount of solid catalyst used is less than 0.05% by weight, the processing time will be extremely long, and if it is too much, there will be no problem with the purpose of one bottle, but the adsorption power of the solid catalyst will lead to product loss. .

As a treatment method using a solid catalyst, a solid catalyst may be added to an intermediate polymer having a sulfuric acid ester group, and the mixture may be mixed and stirred. During processing, it is preferred that a small amount of water be present along with the solid catalyst.

This moisture removal may be carried out using water that is incorporated into the solid catalyst or without an intermediate heavy solvent, or may be carried out in a solvent such as benzene or toluene. The treatment temperature is usually room temperature 160° C.) The treatment time is usually 1 minute to 8 hours, preferably 10 minutes to 1 hour.

The solid catalyst is then removed by a method such as filtration to obtain a treated polymer. After this, if a carboxylic acid anhydride or carboxylic acid halide is used as a cocatalyst, and the terminal remains as an acyloxy group and has not yet been alkaline hydrolyzed, hydrolyze it using the method described above. Converts an acyloxy group to a hydroxyl group.

The PTMG thus obtained usually has a hydroxyl number of about 200-20. Poppy value: 1.0 or less, acid value: 0.1 or less.

Sulfate ester content: several tens to several ppm or less 9 Molecular weight: approximately 500
~6000, the appearance is almost pure white solid or colorless transparent liquid; 1. be.

,″ The effects of the present invention are as follows. Namely.

When a catalyst that requires sulfuric acid or the like is used, the intermediate polymer usually contains sulfuric ester groups in an amount of 1 to several hundred ppm in terms of S03 at the time of termination of polymerization or after alkaline hydrolysis. Until now, acidic hydrolysis had to be performed to convert the sulfate ester group into a hydroxyl group, but in the present invention, this can be done simply by treatment with a solid catalyst. Therefore, the acidic hydrolysis step can be omitted, and P
There is no risk of deterioration due to depolymerization of TMG, and the equipment is made of ordinary glass lining or stainless steel (5us8o4).
．． axs) can be used, and there is no acidic waste liquid, making it extremely useful industrially.

The present invention will be further explained below with reference to Examples.

The present invention is not limited to this. - In the examples,
The sulfate ester group content was measured as So3 content by a general absorbance measurement method using methylene blue. Moreover, parts in the examples indicate parts by weight.

Example 1 150 parts of THF was charged in a 500 nJ reactor equipped with a stirring device, 19 parts of 80% oleum was added thereto so as not to exceed 10°C, and 150 parts of THF was added in advance to 50 parts of THF.
．． 51.5 parts of a hydrogen fluoride-THF solution into which 5 parts of gaseous hydrogen fluoride had been blown and 22 parts of acetic anhydride were added;
The reaction was carried out for 8 hours while stirring and cooling from the outside to maintain the temperature at 5°C. Polymerization was terminated by adding an 80% aqueous solution of caustic soda so that the pH of the reaction solution was 7 to 9. Then, heat to 100℃ to remove unreacted THF.
was recovered. The system was cooled to 90°C, left to stand for 1 hour, and the lower layer was discarded as waste liquid.The intermediate polymer in the upper layer had a hydroxyl value of 81.

Silicification value 46. The sulfate ester content was 8,400 ppm.

A silica-alumina compound (S
102-A120387%-18%) Enter t'L,
Stirring was performed at 18° C. for 80 minutes, and solid matter was removed through filtration I9.

This intermediate polymer has a hydroxyl value of 81. The silicification value was 46° and the sulfate ester content was 4.2 ppm. After that, 40% caustic soda aqueous solution 10F was added to the intermediate polymer, and
The mixture was stirred at 30°C for 8 hours. After cooling to 90'C, the mixture was allowed to stand for 1 hour, and the separated lower layer was discarded as waste liquid. After that, add 201 water to the upper oil layer and PO1? ,, stirred for 10 minutes. Water was removed from the oil layer obtained by static separation in the same manner as above by topping under reduced pressure, and PTMG was obtained by filtration. The obtained PTMG has a hydroxyl value of 78. Silicification value 0. The sulfate ester content was 8.9 ppm. Note that although SUS 816 was used as the material for all devices, no corrosion was observed at all.

Example 2 Toluene 501/and 40% caseinida aqueous solution 1 was added to 100f of the intermediate polymer after THF recovery in Example 1.
After adding OfI, the mixture was stirred vigorously at 180°C for 8 hours. 80℃
The mixture was allowed to stand still for 1 hour, the lower layer was separated and removed, the mixture was further cooled to 40°C, and the precipitated salts were removed by filtration. After toluene was removed by vacuum topping, the intermediate polymer had a hydroxyl number of 78. Silicification value 0. The sulfate ester content was 8200 ppm. 2 g of Kyoward 600 and 1 g of water were added to this intermediate polymer, and the mixture was stirred at 110° C. for 1 hour, and then the solid matter was removed by filtration to obtain PTMG. obtained ntaP
TMG has a hydroxyl value of 78° and a silicification value of 0. The sulfuric acid ester content was 8.9 ppm, and the acid value was 0.1>.

Dumping 49d8 In Example 1, the catalyst to which THF Iζ was added was added with 80% oleum, and the reaction was carried out at 5°C for 5 hours, and a 20% caustic soda aqueous solution was added to adjust the pH to 8 to stop the polymerization.

Thereafter, unreacted THF was recovered, the lower layer was separated, and filtration was performed, and 1420389 was added to the obtained intermediate polymer, followed by stirring at 180° C. for 1 hour. After filtration, the PTMG (D sulfate ester content) obtained was 5.1 ppm.

Claims (1)

[Scope of Claims] 1. An intermediate polymer containing sulfate ester groups obtained by polymerizing tetrahydrofuran using a catalyst containing sulfuric acids and/or sulfuric acid derivatives as an essential component is treated with a monolithic catalyst to form sulfuric ester groups. A method for producing polytetramethylene glycol, which comprises converting into a hydroxyl group. 2. The production method according to claim 1, wherein the 1ia1 catalyst is a compound selected from the group consisting of silicas, aluminas, silica-aluminas, and activated carbon. 3. The amount of solid catalyst is 0.01 to 10% relative to the intermediate polymer.
The manufacturing method according to claim 1 or 2, which is % by weight. 4. Claims in which the treatment temperature with solid catalyst C is 15 to 200°C 6. Claims in which the sulfuric acid is sulfuric acid 1, fuming sulfuric acid and/or sulfuric anhydride The manufacturing method according to any one of Items 1 to 2. ? 7. The silk-making method according to any one of claims 1 to 6, wherein the sulfuric acid derivative is fluorosulfuric acid, chlorosulfuric acid and/or trifluoromethanesulfosic acid.