JP2001302672A - Method for producing spiroglycol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a spiroglycol of high purity sufficient for use as a raw material for highly functional polymers from pentaerythritol and hydroxypivalaldehyde. SOLUTION: The spiroglycol is produced by a two-stage reaction for producing 5,5-dimethylol-2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane which is an intermediate substance by a reaction of the pentaerythriol with the hydroxypivalaldehyde and then carrying out a reaction of the intermediate substance with the hydroxypivalaldehyde in a second stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a high-purity 3,9-bis (1,1-dimethyl-2-dihydroxyethyl) -2,4,8,10-primarily used as a resin raw material.
Tetraoxaspiro- (5,5) -undecane (hereinafter, referred to as
(Referred to as spiro glycol).
Spiro glycol is a polyhydric alcohol having a cyclic acetal in the molecule, polycarbonate, polyester,
These compounds are useful as intermediates or monomers of polymer materials such as polyacrylates, polyurethanes, polyether polyols, and epoxy resins, and as raw materials for adhesives, plasticizers, lubricating oils, and the like.

[0002]

2. Description of the Related Art Conventionally, spiroglycol has been prepared under an acid catalyst.
Pentaerythritol (hereinafter, referred to as PE) and hydroxypivalaldehyde (hereinafter, referred to as HPA) are synthesized by an acetalization reaction in an aqueous solution, and spiroglycol crystals precipitated during this reaction are separated by filtration and washed with water. Through a drying process (US Pat. No. 30,926)
No. 40, JP-A-59-148776, JP-A-64-6
1485, JP-A-7-215979, etc.). The reaction product obtained by such a method has a low purity, and there is a problem in using this as a highly functional polymer raw material.

[0003] For this reason, when it is used as a raw material for a polymer or the like, a further step is required and thorough purification is required. JP-A-2000-34290 discloses crude spiroglycol, C
₄ was dissolved in aliphatic alcohol -C _10, after adding water to the resulting solution had the following to extract and remove impurities in the water, the water layer and the organic layer was separated, spiro glycol was cooled and the organic layer A method for recrystallization is described.

[0004]

The impurities contained in the reaction product of PE and HPA have the same solubility in water as that of the desired spiroglycol.
It can hardly be removed even after the washing process. Therefore, when it is used as a raw material for a polymer or the like, the purity is not sufficient due to these by-products, and the inherent properties of spiroglycol cannot be brought out. For example, copolymerized polycarbonate of bisphenol and spiro glycol originally has excellent optical properties and impact resistance,
Although useful as a resin used in optical applications, polymers polymerized using conventional low-purity commercial products, spiroglycol, do not provide satisfactory impact resistance properties and have coloring problems. Can not do.

In the method disclosed in Japanese Patent Application Laid-Open No. 2000-34290, spiroglycol itself has a low solubility in aliphatic alcohols of C _{4 to} C _10. Requires an organic solvent, and
Complicated operations are required in the production process such as high-temperature hot filtration, which is industrially problematic. The object of the present invention is to use PE and H
An object of the present invention is to solve the above-mentioned problems in the production of spiroglycol by reacting with PA and to provide a method for producing spiroglycol of high purity sufficient for use as a functional polymer raw material.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for producing high-purity spiroglycol in order to solve the above-mentioned problems. As a result, it was found that the purity of the reaction product of PE and HPA was low. Is caused by a polymer of pentaerythritol (hereinafter, referred to as polypentane) in PE used as a raw material, that is, di-pentaerythritol (hereinafter, d).
i-PE), bis-pentaerythritol (hereinafter referred to as bis-PE), tri-pentaerythritol (hereinafter referred to as tri-PE), and the like. By carrying out the reaction in two stages, spiroglycol of high purity can be obtained, and it is possible to reduce the melting Hazen color number after holding at 260 ° C. for 5 hours in the air to No. 25 or less, and to obtain excellent strength and optical properties. The present inventors have found that they can be sufficiently used as a raw material of a highly functional polymer resin having the same, and have reached the present invention.

That is, the present invention relates to the production of spiroglycol by reacting monopentaerythritol with hydroxypivalaldehyde in the presence of an acid catalyst.
The intermediate, 5,5-dimethylol-2-
(1,1-dimethyl-2-hydroxyethyl) -1,3
-A process for producing spiroglycol, which comprises producing dioxane and performing a second-stage reaction of the intermediate with hydroxypivalaldehyde.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The acid of the catalyst used in the acetalization reaction of the present invention is not particularly limited, but generally, for example, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, etc., and P-toluenesulfonic acid, Organic acids such as methanesulfonic acid are useful. The acetalization reaction operation can be performed by any of a batch system, a semi-continuous system, and a continuous system with stirring. The pressure in the reaction system may be either normal pressure, reduced pressure, or increased pressure. However, the pressure is not particularly required to be reduced or increased, and the reaction is usually performed at normal pressure.

In the first stage of the acetalization reaction in the present invention, PE and HPA are reacted in the presence of an acid catalyst to obtain water-soluble 5,5-dimethylol-2- (1,1-1-
Dimethyl-2-hydroxyethyl) -1,3-dioxane (hereinafter referred to as DOT) is synthesized. At this time, HPA is reacted at 0.8 to 1.2 mol with respect to PE charged at a reaction molar ratio, and the reaction is carried out under stirring at 50 to 95 ° C, preferably 6 to 95 ° C.
The reaction is carried out at 0 to 90 ° C. for about 1.5 to 3.0 hours, preferably for 2 to 2.5 hours. When the temperature of HPA is reduced to 50 ° C. or lower in an aqueous solution, the dimer structure 2,1,1-1-
Dimethyl-2-hydroxymethyl-5,5-dimethyl-
It becomes 4-hydroxy-1,3-dioxane and turns into a slurry. For this reason, if possible, it is effective to carry out the reaction in a homogeneous solution at a temperature in the range of 60 to 90 ° C., but a part of the HPA may be turned into a dimer to form a slurry at the initial reaction stage.

[0010]

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The first-stage reaction is carried out as described above, and the poly-pentaacetal ring compound and the poly-pentaspiro ring compound and a part of by-produced spiroglycol are precipitated as a slurry, while the generated DOT is dissolved in water. Be present in dissolved form. Next, the first-stage acetalization reaction liquid is subjected to solid-liquid separation by filtration without neutralization. Here, HPA is added to the filtrate containing DOT, and the second-stage acetalization reaction is continuously performed. On this occasion,
The reaction molar ratio was set such that HPA was 0.8 to DOT in the filtrate.
The reaction is desirably performed at about 1.2 mol. This second-stage reaction is carried out at 60 to 90 ° C. under stirring at about 2.0 to 3.0.
Perform for 0 hours. Since the reaction catalyst acid added in the first-stage reaction is in the filtrate, there is basically no need to add it,
It is preferable to add a necessary amount in consideration of a loss at the time of solid-liquid separation. By performing the second-stage acetalization reaction in this way, spiroglycol is obtained as crystals. After neutralizing this, it is separated by filtration, further washed with water and dried to obtain the product spiroglycol.

In the present invention, general grade products are used for the raw materials PE and HPA, and PE is produced by an aldol condensation reaction of acetaldehyde and formaldehyde in the presence of a base catalyst, followed by a cross-Canizallo reaction. In this reaction product solution, sodium formate, di-PE, bis-
Contains PE, tri-PE, and other unknowns. PE is generally separated and recovered from water by crystallization in water.
However, it is extremely difficult to obtain high-purity PE in a high yield. This is because it is not easy to completely remove poly-penta such as di-PE and bis-PE. Typical industrial grade PE purity is approximately 90% PE
~ 95%. To obtain higher purity PE,
It is necessary to further treat the product PE with an acid decomposition step, or to use a large amount of water in the crystallization step and to recrystallize it many times in a form that limits the circulating use of mother liquor and the like. Become. These methods are not performed except in special cases where costs are ignored because the yield is greatly reduced.

As described above, spiroglycol obtained by reacting with HPA in the presence of an acid catalyst while containing poly-penta other than PE contains spirocyclic compound by-products corresponding to impurities. become. That is, a spirocyclic compound of HPA and di-PE or HPA and bis-PE
And a spiro ring compound. Since these compounds have the same solubility in water as the target spiroglycol or are more difficult to dissolve, they cannot be removed even if recrystallization is repeated in water.

Therefore, when the spiroglycol thus obtained is used as a raw material for a polymer or the like, the inherent properties of spiroglycol cannot be brought out because these by-products are contained. For example, a copolymerized polycarbonate of bisphenol and spiroglycol is originally useful as a resin used for optical applications because it has excellent optical properties and impact resistance, but a spirocyclic compound by-produced from poly-pentane is used. A polymer polymerized using spiroglycol containing a trace amount did not exhibit satisfactory impact resistance properties, and could not be used for optical applications. Also,
In particular, if there are many bis-PEs, the bis-PE
It may be easily decomposed by acid itself, or it may be a cause of coloring in the case of copolycarbonate.

According to the present invention, the solubility in 100 parts of water is D.
OT 15 parts (50 ° C.), while utilizing the physical property that the solubility of the poly-pentaacetal ring compound and the poly-penta-spiro ring compound is 0.1 part or less, D obtained from the first stage acetalization reaction
Spiroglycol obtained by reacting OT with PE as a raw material has high purity, and is of sufficient quality especially as a highly functional polymer raw material.

[0016]

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples. In the following examples, (%) means (% by weight).

Example 1 595 parts of IBAL and 600.6 parts of 40% formalin were mixed, stirred at 40 ° C. in a nitrogen stream, and added with 24 parts of triethylamine (hereinafter referred to as TEA) over 5 minutes. The reaction starts simultaneously with the addition of TEA, and after 10 minutes,
The reaction temperature rose to 65 ° C. Once the unreacted IBAL refluxed violently, it was gradually cooled by external cooling with cold water. Thereafter, the temperature of the reaction solution was gradually increased while repeating cooling and warming.
0 ° C. was reached. After the reaction was further performed at 90 to 93 ° C. for 5 minutes, the reaction was temporarily cooled to 60 ° C. by external cooling to stop the reaction. Next, at a temperature of 60 to 70 ° C. and a pressure of 53 KPa, 125 parts of a low-boiling distillate such as unreacted IBAL, TEA, and methanol were distilled off. The composition of the reaction product liquid after the distillation of the low-boiling fraction was analyzed by gas chromatography (hereinafter, referred to as GC), and as a result, the composition was as follows. HPA6
8.2%, IBAL 0.12%, formaldehyde
0.36%, IBDL-Aldol 0.28% TE
A 0.09%, TEA-formic acid 1.6%, NPG 1.
8%, neopentyl glycol monohydroxypivalate monoester 1.2%, neopentyl glycol monobutyrate monoester 0.4% and water 23.77%.

The reaction product liquid 109 after distillation of the low-boiling fraction is removed.
After adding 403.6 parts of water to the half amount of 4.6 parts and 547.2 parts, 497.5 parts of PE and 8.0 parts of catalyst p-toluenesulfonic acid (hereinafter referred to as PTSA) were added and stirred. Under the reaction temperature of 60 to 65 ° C., the first stage acetalization reaction was performed for 2 hours. After the reaction, the precipitated poly-pentaacetal ring compound and polypentapentaspiro ring compound and 82 parts (water content) of by-product spiroglycol and the like were partially removed using a centrifuge. Next, to 5174.4 parts of the obtained filtrate containing 14.3% of DOT, 533.8 parts and 5 parts of PTSA of 547.4 parts of the aldol reaction product liquid previously divided into two parts were added and stirred. The second stage acetalization reaction was performed at a reaction temperature of 80 to 90 ° C. for 3 hours. As a result, 5713.2 parts of a reaction product solution in which spiro glycol was precipitated in a slurry was obtained. After the second stage reaction,
Neutralization was performed using a 10% aqueous sodium carbonate solution until the pH value of the reaction solution reached 7.5. Spiroglycol precipitated from this reaction solution was separated into solid and liquid using a centrifuge to obtain spiroglycol as a cake. After further rinsing with water, it was dried using a vacuum drier kept at 80 ° C., and spiroglycol of high purity 942.9.
Got a part. The yield was 87% based on PE. Also,
The obtained spiroglycol had a melting point of 204 ° C., and had a high melting color number of 20 after holding at 260 ° C. in the atmosphere for 5 hours.

Example 2 In Example 1, the first stage acetal reaction was carried out at 50 ° C.
The procedure was performed in the same manner as in Example 1 except that the time and the acetal reaction in the second stage were performed at 75 ° C. for 5 hours. As a result, 9
45.0 parts of spiro glycol were obtained. The yield is 87.3.
%Met. In addition, the melting point of the obtained spiroglycol 2
The temperature was 04 ° C., the melting Hazen color number after holding at 260 ° C. in the atmosphere for 5 hours was 20 and high quality.

Example 3 The procedure of Example 1 was repeated, except that the catalyst for the acetal reaction was changed to 35% hydrochloric acid. As a result, 952.9 parts of spiro glycol were obtained. Yield 8
8.0%. Further, the melting point of the obtained spiroglycol was 204 ° C., and the melting Hazen color number after holding at 260 ° C. for 5 hours in the air was 25, which was high quality.

Comparative Example 1 The procedure of Example 1 was repeated, except that the acetalization reaction was carried out at once without distinction from the first and second stages of the reaction.
Performed similarly. As a result, 867.6 parts of spiro glycol were obtained. The yield was 78.1%. The melting point of the obtained spiroglycol was 199.5 ° C.
After holding at 60 ° C. for 5 hours, the melted Hazen color number was 250, and the color was low in quality.

[0022]

As is clear from the above examples, according to the present invention, a high-purity spiroglycol which can be used as a raw material for a high-functional polymer can be easily obtained. That is, when reacting HPA, which is a raw material of spiroglycol, with PE,
The acetalization reaction is separated into two stages and is produced from di-PE, bis-RE, and tri-PE contained in the raw material PE, and is added to impurities other than M-PE which cannot be separated from spiroglycol by washing with water or the like. By removing the acetal ring compound and the spiro ring compound after the DOT synthesis in the first stage of the reaction, high-purity spiro glycol can be easily obtained. According to the present invention, spiroglycol having a high purity sufficient for use as a high-functional polymer raw material having a molten Hazen color number of 25 or less after holding at 260 ° C. for 5 hours in the atmosphere is obtained, and the present invention has great industrial significance.

Continued on the front page (72) Fukutake Miyashita 3-10 Mizushima Kaigan-dori, Kurashiki City, Okayama Prefecture Inside Mizushima Plant of Mitsubishi Gas Chemical Co., Ltd. (72) Masafumi Watanabe 3-10 Mizushima Kaigan-dori, Kurashiki City, Okayama Prefecture Mitsubishi Gas Chemical Co., Ltd. Mizushima Plant F-term (reference) 4C071 AA04 BB01 CC14 EE06 FF16 GG03 KK01 LL07

Claims (4)

[Claims] In producing a spiroglycol by reacting pentaerythritol with hydroxypivalaldehyde in the presence of an acid catalyst, first, an intermediate 5 is prepared by a first-stage reaction between pentaerythritol and hydroxypivalaldehyde. , 5-Dimethylol-2- (1,1-dimethyl-
A method for producing spiroglycol, comprising producing (2-hydroxyethyl) -1,3-dioxane, and performing a second-stage reaction between the intermediate substance and hydroxypivalaldehyde. 2. The method for producing spiroglycol according to claim 1, wherein the first-stage reaction solution is filtered, and the filtrate is subjected to a second-stage reaction. 3. The reaction according to claim 1, wherein the supply molar ratio of pentaerythritol and hydroxypivalaldehyde is 1: 0.8 to 1.
2. The method for producing spiroglycol according to claim 1, which is 1.2. 4. The 5,5-dimethylol-2 of the second stage reaction
-(1,1-dimethyl-2-hydroxyethyl) -1,
The method for producing spiroglycol according to claim 1, wherein the supply molar ratio of 3-dioxane and hydroxypivalaldehyde is 1: 0.9 to 1.4.