JPH0558929A - Trans-14-cycloheaxnedimethanol tetrahydrate crystal and production of tetrahydrate crystal or anhydride of the same - Google Patents

Abstract

PURPOSE:To obtain trans-1,4-cyclohexanedimethanol tetrahydrate crystal, suitable for industrial production, having excellent handleability, not requiring drum containers, etc., in a distribution stage, not needing previous heating and dissolu tion before use. CONSTITUTION:A crystal of trans-1,4-cyclohexanedimethanol (CHDM) tetrahydrate shown by the molecular formula C8H16O2.4H2O useful as a raw material for polyester-based coating compound, fibers, resins, etc. This crystalline compound has 20-23 deg.C melting point, readily becomes a liquid state, is obtained by crystallizing a mixture of cis-isomer and trans-isomer of 1,4-CHDM and is produced by a process suitable for industrial production. Further, extremely easily handleable trans-1,4-CHDM anhydride is industrially and readily produced by removing its water of crystallization and grinding.

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

The present invention is a trans-form useful as a raw material or a chemical intermediate for polyester-based paints, fibers, resins and the like.
The present invention relates to 1,4-cyclohexanedimethanol tetrahydrate crystals and a method for producing the tetrahydrate crystals or anhydride.

[0003]

[Prior Art]

Conventionally, 1,4-cyclohexanedimethanol (hereinafter sometimes abbreviated as 1,4-CHDM).
Was industrially produced, for example, by reducing 1,4-cyclohexanedicarboxylic acid dimethyl ester with hydrogen in the presence of a copper chromium catalyst and then distilling it.

1,4-CHDM thus obtained
Is a wax-like or muskite-like substance at room temperature, which usually consists of about 70% of trans form and about 30% of cis form.

By reducing para-xylene glycol with hydrogen, 1,4-CHDM having a relatively large amount of cis isomer is obtained.
Are also known to be manufactured.

Comparing the properties of the cis form and the trans form, the melting point of the high purity cis form is 42 to 43 ° C, and the melting point of the high purity trans form is 66 to 66.5 ° C.

Regarding the derivative thereof, it is known that the polyester resin produced from the trans body has a higher glass transition point and a higher softening point and is superior in properties.

Therefore, trans-1,4-CHDM is desired as a raw material for polyester paints, fibers, resins and the like, and its demand is expected to increase.

In the laboratory, trans-1,4-CHDM was produced, for example, by the following method.

Acta Pharmaceutica Suetica 5 (5), 449
-As introduced on page 456 (1968), 1,
A method in which a cis-trans mixture of 4-CHDM is trimethylsilylated and chromatographed on a diglycerol column.

Journal of Liquid Chromatography 10
(6) A method for chromatographic separation of a 1,4-CHDM cis-trans mixture as described on pages 1077-1084 (1987) using a cyclodextrin-bonded silica gel column.

Journal of the Chemical Society 404-4
1,4-, as introduced on page 07 (1953)
A method of obtaining trans-1,4-CHDM by converting a cis / trans mixture of CHDM into dibenzoate, selectively crystallizing the mixture by utilizing the difference in crystallinity, and then hydrolyzing again.

[0014]

[Problems to be Solved by the Invention]

However, what is obtained by industrial production by carrying out ordinary distillation is a cis / trans mixture containing about 30% of cis isomer.

As described above, 1,4-CHDM containing about 30% of cis isomer has a melting point of about 55 ° C., and therefore has many problems in handling.

For example, in the case of commercial distribution, an expensive drum container is required because it is wax-like or musket-like.
It is necessary to heat and dissolve at a temperature of 0 to 60 ° C., decomposition and coloration occur during the heating and melting, and the cost required for heating and melting is high, and it is manufactured using this as a raw material. There was a problem that the goods became expensive.

Further, the transformer-1, which is shown in the above items,
The 4-CHDM production method is an analytical method or a laboratory method, and has problems such as low yield, high cost, and complicated operation, and is not suitable for industrial production.

Accordingly, the transformers 1, 4 which are excellent in handling, do not require a drum container or the like at the distribution stage, need not be heated and melted before use, and can be manufactured by a process suitable for industrial production. -CHDM was desired.

[0020]

[Means for Solving the Problems]

The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems, and as a result, by crystallizing a 1,4-CHDM cis / trans mixture in an aqueous solution, a melting point of 2 was obtained.
Trans-1,4-C that easily becomes liquid at 0-23 ° C
We have succeeded in obtaining HDM tetrahydrate crystals for the first time.

Furthermore, by removing the water of crystallization of this product and pulverizing it, powder trans-1, which is extremely easy to handle,
We succeeded in easily obtaining 4-CHDM anhydride and completed the present invention.

That is, the means for solving the problems of the present invention are as follows.

First, it is a crystal of trans-1,4-cyclohexanedimethanol tetrahydrate represented by the molecular formula C ₈ H ₁₆ O ₂ .4H ₂ O.

Secondly, it is the trans-1,4-cyclohexanedimethanol tetrahydrate crystal described in the first paragraph having a melting point of 20 to 23 ° C.

Thirdly, there is provided a method for producing trans-1,4-cyclohexanedimethanol tetrahydrate crystals which is crystallized from an aqueous solution of a mixture of cis and trans isomers of 1,4-cyclohexanedimethanol.

Fourth, after crystallization of trans-1,4-cyclohexanedimethanol tetrahydrate by crystallization from an aqueous solution of a mixture of cis and trans isomers of 1,4-cyclohexanedimethanol, water of crystallization is added. It is a method for producing trans-1,4-cyclohexanedimethanol anhydrous by removing.

Fifth, after producing trans-1,4-cyclohexanedimethanol tetrahydrate crystals by crystallization from an aqueous solution of a mixture of cis and trans isomers of 1,4-cyclohexanedimethanol, water of crystallization is added. It is a method for producing powdery trans-1,4-cyclohexanedimethanol anhydrous by removing and pulverizing.

The contents of the present invention will be described in detail below.

First, the transformer according to the present invention will be described below.
1 shows various properties of 1,4-CHDM tetrahydrate crystal.

(1) Elemental analysis measurement value C = 44.1% H = 11.1% O = 44.8% Theoretical value C = 44.4% H = 11.2% O = 44.4%

(2) Molecular weight 216.3

(3) Melting point 20-23 ° C.

(4) Moisture measurement by Karl Fischer moisture meter Measured value 33.8% Theoretical value 33.3%

(5) Appearance Transparent plate crystal

(6) Qualitative Analysis This crystal was obtained by using the commercially available trans-1,4-CH
Gas chromatography using DM (reagent) as a standard,
When analyzed by high performance liquid chromatography, it is detected at the same position as the standard trans-1,4-CHDM.

(7) X-ray diffraction analysis (a) A trans-1,4-CHDM tetrahydrate crystal was placed on a non-reflective sample plate in a dry ice atmosphere, and X-ray diffraction analysis (X-ray diffraction manufactured by JEOL Ltd. Analyzer, JDX-3500). The results are shown in Figure 1. (b) As a reference, trans-1,4-CHDM anhydrous obtained from trans-1,4-CHDM tetrahydrate crystals was placed on a non-reflective sample plate under a dry ice atmosphere, and X-ray diffraction analysis ( JEOL X-ray diffraction analyzer, JDX-350
0) was performed. The results are shown in Figure 2.

From the above facts, it is judged that the crystal according to the present invention is trans-1,4-CHDM tetrahydrate, which has never been known.

Next, the transformer-1,4-C according to the present invention
Method for producing HDM tetrahydrate crystals and trans-1,4-
The method for producing CHDM anhydride and powder trans-1,4-CHDM anhydride will be described.

1,4-CH used as a raw material in the present invention
The DM may be any mixture as long as it is a mixture of cis and trans isomers, and the production method is not limited.

Trans-1,4 in the crystallization of the present invention
The concentration of the -CHDM aqueous solution is 10 to 60% (hereinafter,% represents% by weight unless otherwise specified), preferably 30 to.
50% is good.

If the concentration is higher than 60%, it becomes difficult to separate the precipitated trans-1,4-CHDM tetrahydrate crystals,
When it is less than 10%, the yield of trans-1,4-CHDM tetrahydrate crystals is small and the production efficiency is poor.

The crystallization temperature is trans-1,4-CH.
Since the melting point of DM tetrahydrate crystals is 20 to 23 ° C, it is necessary to perform it at a low temperature of 0 to 15 ° C.

The crystal seed for crystallization can be crystallized with or without addition, but the crystallizing time can be shortened by adding it.

Crystallized trans-1,4-CHDM tetrahydrate crystals can be separated by a commonly used centrifugation method or filter filtration.
Since the melting point of 4-CHDM tetrahydrate crystals is 20 to 23 ° C, it is necessary to treat the crystals at 5 to 15 ° C.

Trans-1,4-CHD obtained here
Since the M tetrahydrate crystal has a melting point of 20 to 23 ° C., it becomes a liquid with a slight heating, and therefore, handling such as taking out from a container, which has been troublesome until now, is easy.

The water of crystallization can be easily removed by a reduced-pressure drying method, a freeze-drying method or the like, which is carried out while heating if necessary.

The trans-body-rich content 1,4-having a trans-body content of about 90% or more thus obtained
The melting point of the anhydrous CHDM varies depending on the content of the trans isomer, but it is generally 60 to 65 ° C.

Therefore, 1,4-CHD with a high trans content
Since the anhydrous M forms a relatively hard solid by cooling, it is easy to use a method of kneading and then molding while cooling, a method of cooling and solidifying and then cutting, and the like to easily give a granular powder which is smooth. Transformer-1,4-C
HDM anhydrous can be obtained.

By using these trans-1,4-CHDM tetrahydrate crystals, trans-1,4-CHDM anhydrous and powdered trans-1,4-CHDM anhydrous, the glass transition point is high and the properties are high. It is possible to produce a derivative such as a polyester resin having excellent properties.

For example, 1,4-CHDM having a trans isomer content of 80% or more, more preferably 1,4-CHDM having a trans isomer content of 90% or more is contained in an amount of 50 to 97 mol%, and another glycol component is contained. Ethylene glycol as 3
The polyester obtained by reacting a dicarboxylic acid component such as terephthalic acid with a content of ˜50 mol% is a conventional product, that is, 1,4 having a trans isomer content of less than 80%.
The heat resistance is remarkably improved as compared with a product produced by the same reaction using -CHDM.

Further, in producing the above polyester,
If desired, various properties can be further strengthened by adding various improving agents such as fibrous reinforcing agent, flame retardant, anti-coloring agent, antistatic agent, heat-resistant agent and weathering agent.

Thus, the trans-1,4-CHDM
By making it possible to easily produce tetrahydrate crystals and powdery trans-1,4-CHDM anhydride, a polyester resin, fiber, etc. having excellent properties using trans-1,4-CHDM can be obtained. It becomes possible to manufacture, and eventually
The applications of 1,4-CHDM can be expanded.

Although para-xylene glycol is dissolved in a solvent such as water and reduced in the presence of a reducing catalyst such as ruthenium, 1,4-CHDM having a relatively large amount of cis isomer can be prepared. Thus obtained 1,
4-CHDM as it is or JP-A-2-131442
After applying the isomerization method introduced in the publication, it is applied to the method for producing trans-1,4-CHDM tetrahydrate crystals and powdery trans-1,4-CHDM anhydride of the present invention, and , 4-CHDM can be separated into a high trans isomer content product and a high cis isomer content product.

[0055]

【Example】

The present invention will be further described below with reference to examples, but these examples do not limit the scope of the present invention. In addition,% represents% by weight unless otherwise specified.

[0057]

Example 1

Commercially available 1,4-CHDM having a purity of 99.8%
(Cis body 27%, trans body 73%) was dissolved in water to give 5
The solution was made into a 0% aqueous solution and left at 5 ° C. for 1 day.

The precipitated crystals were centrifuged while keeping the temperature below 10 ° C. to obtain crystals.

The crystal has a transparent plate-like appearance, and by elemental analysis, C = 44.1%, H = 11.1%, O = 4.
4.8%, molecular weight 216.3, melting point 22.5 ° C
Met. The water content measured by the Karl Fischer moisture meter was 34%.

The crystals were qualitatively analyzed by gas chromatography and high performance liquid chromatography using currently commercially available trans-1,4-CHDM (reagent) as a standard product, and found to be the same as standard trans-1,4-CHDM. Was detected at the position. In addition, when analyzed by gas chromatography, the trans form was 99.4%.

Further, the crystal was placed on a non-reflective sample plate in a dry ice atmosphere, and an X-ray diffraction analyzer (made by JEOL,
X-ray diffraction analysis was carried out using JDX-3500).
The result is shown in FIG. In addition, the result shown in FIG.
This was different from the X-ray diffraction pattern (FIG. 2) of anhydrous trans-1,4-CHDM shown in Example 3 below.

From the above results, the crystal obtained in Example 1 is a novel crystal body in which trans-1,4-CHDM and water are bound, trans-1,4-CHDM tetrahydrate crystal. Was confirmed.

[0064]

Example 2

250 kg of 1,4-cyclohexanedicarboxylic acid dimethyl ester and 25 kg of copper chromium catalyst [C-5, manufactured by Sakai Chemical Industry Co., Ltd.] were placed in a 550 liter autoclave and stirred at 260 ° C., and hydrogen pressure was 150 kg / cm ^2.
After hydrogen reduction with, the catalyst was removed by filtration, and by-product methanol in the obtained filtrate was removed by concentration to prepare 1,4-CHDM as a raw material.

As a result of analyzing this product by gas chromatography, the purity of 1,4-CHDM was 98%.
It contained 28% of cis isomer and 72% of trans isomer.

1,4-CHDM50 of the above-prepared raw material
After dissolving Kg in 50 Kg of water, the mixture was cooled to 5 ° C., a small amount of the trans-1,4-CHDM tetrahydrate crystal obtained in Example 1 was added as a crystal seed, and the mixture was allowed to stand for 1 day.

By centrifuging the precipitated crystal while keeping it at 10 ° C. or lower, 33 kg of trans-1,4-CHDM tetrahydrate crystal was obtained.

When this product was analyzed by gas chromatography, it had a purity of 99.7% and a trans isomer of 9
It was 7.7%.

The moisture content measured by the Karl Fischer moisture meter was 33.2% and the melting point was 21 ° C.

[0071]

Example 3

Trans-1,4-CHD obtained in Example 2
10 kg of M tetrahydrate crystals are decompressed at 5 mmHg, 70 ° C.
It was heated at 18 ° C for 18 hours to remove water of crystallization and then cooled and solidified to give trans-1,4-CHDM anhydride 6.7.
Kg was obtained.

The analysis result of this product by gas chromatography showed that the purity was 99.7% and that the trans form was 97.7.
%Met.

The water content measured by the Karl Fischer moisture meter was 0.2%, and the melting point was 64 ° C.

Further, this product was placed on a non-reflective sample plate in a dry ice atmosphere and subjected to X-ray diffraction analysis using an X-ray diffraction analyzer (JDX-3500, manufactured by JEOL Ltd.). The result is shown in FIG.

[0076]

Example 4

Trans-1,4-CHD obtained in Example 2
10 kg of M tetrahydrate crystals are decompressed by 10 mmHg, 80
After removing the water of crystallization by heating at ℃ for 20 hours, it was poured into a stainless steel vat in the molten state and left overnight at room temperature, and the solidified mass was frozen cutter [FZ type,
By Shonan Sangyo Co., Ltd.] to obtain a white powder trans-1,4-CHDM anhydride which is easy to handle.

The analysis result of this product by gas chromatography showed that the purity was 99.7% and that the trans form was 97.7%.
%Met.

The water content measured by the Karl Fischer moisture meter was 0.6%, and the melting point was 63 ° C.

[0080]

【The invention's effect】

Trans-1,4-CHDM according to the present invention
Tetrahydrate crystals are excellent in handling, do not require a drum container or the like at the distribution stage, and do not need to be heated and dissolved before use, and thus can be produced by a process suitable for industrial production. it can.

Furthermore, according to the present invention, the transformer-1,
4-CHDM Anhydrous and Powder trans-1,4-CHD
The M anhydride can be easily produced industrially.

[Brief description of drawings]

FIG. 1 shows an X-ray diffraction pattern of trans-1,4-CHDM tetrahydrate according to the present invention.

FIG. 2 shows an X-ray diffraction pattern of anhydrous trans-1,4-CHDM according to the present invention.

Continued Front Page (72) Inventor Azusa Tokari 232-1 Fujishimoto Market, Shizuoka Prefecture Corp. Senju 2-205 (72) Inventor Okamoto Directly 4-61-17 Minamihanajima, Matsudo City, Chiba Prefecture

Claims (5)

[Claims] 1. A crystal of trans-1,4-cyclohexanedimethanol tetrahydrate represented by the molecular formula C ₈ H ₁₆ O ₂ .4H ₂ O. 2. The trans-1,4-cyclohexanedimethanol tetrahydrate crystal according to claim 1, which has a melting point of 20 to 23 ° C. 3. Crystallization from an aqueous solution of a mixture of cis and trans isomers of 1,4-cyclohexanedimethanol.
Process for producing crystals of trans-1,4-cyclohexanedimethanol tetrahydrate. 4. A crystal of trans-1,4-cyclohexanedimethanol tetrahydrate is produced by crystallization from an aqueous solution of a mixture of cis and trans isomers of 1,4-cyclohexanedimethanol, and then water of crystallization is removed. A method for producing trans-1,4-cyclohexanedimethanol anhydrous. 5. A crystal of trans-1,4-cyclohexanedimethanol tetrahydrate is produced by crystallization from an aqueous solution of a mixture of cis and trans isomers of 1,4-cyclohexanedimethanol, and then water of crystallization is removed. A method for producing powdery trans-1,4-cyclohexanedimethanol anhydrous by pulverization.