JP2631847B2 - Method for producing polyhydric alcohol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention reacts hydroxypivalaldehyde with pentaerythritol to obtain high purity and high yield of β, β,
The present invention relates to a method for producing β ′, β′-tetramethyl-2,4,8,10-tetraoxaspiro [5,5] undecane-3,9-diethanol (hereinafter referred to as spiroglycol).

Spiroglycol is urethane, ester, thiol,
As a synthetic intermediate for low molecular compounds such as ether compounds,
Or, as an intermediate of a high molecular compound such as polyurethane, polyester, polyether polyol, epoxy resin,
Furthermore, as a raw material for synthetic lubricating oils, cross-linking agents, reactive diluents, plasticizers, adhesives, modifiers, and resins such as photocurable, chemical-resistant, heat-resistant, abrasion-resistant, weather-resistant, and impact-resistant resins. Useful.

(Prior art and problems to be solved by the present invention) Conventionally, spiroglycol reacts hydroxypivalaldehyde and pentaerythritol with an acid catalyst (ie, sulfuric acid, phosphoric acid,
It is produced by reacting in the presence of hydrochloric acid, p-toluenesulfonic acid, methanesulfonic acid) in water or an organic solvent. (U.S. Patent No. 3,092,640; U.S. Patent No. 2,945,008
No., JP-A-59-148776). However, there is no example or suggestion of performing the reaction using nitric acid in these production methods. Further, according to the additional test by the present inventors (see Comparative Example 1), the yield was about 80% and the purity was 90% in these methods.
This is about several percent, which is not always satisfactory. Therefore, it is desired to develop a method for producing spiroglycol with satisfactory yield and purity.

(Means for Solving the Problems) The present inventors have conducted various studies to solve the above problems, and as a result, it has been found that spiroglycol that can satisfy both the yield and the purity can be obtained by performing the reaction using nitric acid as the acid catalyst. Was obtained.

That is, the present invention is a method for producing spiroglycol, which comprises reacting pentaerythritol and hydroxypivalaldehyde in an aqueous solvent using nitric acid as an acid catalyst.

The amount of nitric acid used is 5 to 40% by weight, preferably 10 to 20% by weight, based on the charged amount of pentaerythritol.

The reaction temperature is preferably in the range of 50 to 75 ° C, preferably 60 to 70 ° C.
° C is good. If the temperature is lower than 50 ° C., the reaction rate is slow and not industrial, and the yield and purity of spiroglycol decrease. 75 ℃
Above is undesirable because the amount of by-products increases.

Examples of the aqueous solvent used include water, a mixed solvent of a water-soluble solvent and water, and the like.

The reaction method is as follows: (1) Preliminary reaction temperature (50-70 ° C)
A method in which a hydroxypivalaldehyde solution and a nitric acid are co-injected into an aqueous solution of pentaerythritol kept at the same temperature as that of the reaction, and (2) a hydroxypivalaldehyde solution is added to a nitric acid aqueous solution of pentaerythritol (3) A method of reacting while simultaneously injecting an aqueous solution of pentaerythritol and nitric acid into a solution of hydroxypivalaldehyde, and (4) A method of adding a nitric acid aqueous solution of pentaerythritol to a solution of hydroxypivalaldehyde. The reaction may be carried out by any of the following methods (5) or a method in which nitric acid is dropped into a mixed solution of a hydroxypivalaldehyde solution and an aqueous solution of pentaerythritol, or charged at once.

The charged amount of pentaerythritol is preferably 0.7 to 1.0 mol, and more preferably 0.85 to 0.95 mol, per 1 mol of hydroxypivalaldehyde.

When the reaction is carried out by the co-injection or addition method, the co-injection or addition time is preferably 0.5 to 5 hours, and there is no particular limitation on the co-injection or addition time within this range.

The reaction pressure is not particularly limited, but it is practically carried out under normal pressure industrially.

In the following examples,% and parts mean% by weight and part by weight, respectively, unless otherwise specified.

Example 1 Aldol reaction product liquid obtained by reacting isobutyraldehyde with formaldehyde using triethylamine as a catalyst (containing 58% of hydroxypivalaldehyde)
306.3 parts were placed in a pressure-equalizing double-tube dropping funnel kept warm with hot water at 60 ° C. Preliminarily add 115.6 parts of pentaerythritol to 1,000
306.3 parts of the aldol reaction product solution in 60% aqueous pentaerythritol solution
22 parts of nitric acid were co-injected over about 5 hours, and the reaction temperature was 60
The reaction was carried out at 9 ° C for 9 hours including the co-injection time. After completion of the reaction, use a 48% aqueous sodium hydroxide solution to adjust the pH of the reaction solution to 7.
Neutralization was performed until 5. After the neutralization, the reaction solution was filtered, and the remaining filter cake was washed twice with hot water at 80 ° C. After removing the filter cake and drying, 24
8 parts of spiro glycol were obtained. This corresponds to a yield of 96 mol% (based on pentaerythritol). The purity was 99%.

Example 2 Aldol-reactive solution 30 obtained in the same manner as in Example 1
After mixing 6.3 parts and 1115.6 parts of an aqueous pentaerythritol solution containing 115.6 parts of pentaerythritol, the mixture was heated to 60 ° C. and stirred to form a uniform solution. To this mixed solution, 22 parts of 60% nitric acid was added at a time, and the reaction was carried out at 60 ° C. for 6 hours. Post-treatment after the reaction is also performed in the same manner as in Example 1, and after drying.
246 parts of spiro glycol were obtained. This corresponds to a yield of 95 mol% (based on pentaerythritol). The purity was 98%.

Example 3 115.6 parts of pentaerythritol and 22 parts of 60% nitric acid were added to 500 parts of water.
The acidic aqueous solution that had been dissolved in the solution and made uniform was kept at 70 ° C. in advance. A solution of 188 parts of hydroxypivalaldehyde having a purity of 98% dissolved in 600 parts of water was added uniformly over a period of about 1 hour to an aqueous solution of hydroxypivalaldehyde at 65 ° C, which was added over a period of about 1 hour. A time reaction was performed.
Post-treatment after the reaction was performed in the same manner as in Example 1.
After drying, 254 parts of spiro glycol were obtained. This corresponds to a yield of 98 mol% (based on pentaerythritol).
The purity was 99%.

Comparative Example 1 Aldol reaction product solution 30 obtained in the same manner as in Example 1
After mixing 6.3 parts and 1115.6 parts of an aqueous pentaerythritol solution containing 115.6 parts of pentaerythritol, the mixture was heated to 60 ° C. and stirred to form a uniform solution. To this mixed solution, 22 parts of 98% sulfuric acid was added at a time, and the reaction was carried out at 60 ° C. for 6 hours. Post-treatment after the reaction is also performed in the same manner as in Example 1, and after drying.
207 parts of spiro glycol were obtained. This corresponds to a yield of 80 mol% (based on pentaerythritol). The purity was 93%.

(Effect of the Invention) According to the method of the present invention, spiroglycol having a higher yield and a higher purity can be produced as compared with the conventional method, and an industrially useful method can be provided.

Claims (1)

(57) [Claims] 1. β, β, β ′, β′- characterized in that pentaerythritol and hydroxypivalaldehyde are reacted in an aqueous solvent using nitric acid as an acid catalyst.
Tetramethyl-2,4,8,10-tetraoxaspiro [5,5]
A method for producing undecane-3,9-diethanol.