JPS6067481A - Purification of dibenzylidenesorbitol - Google Patents

Abstract

PURPOSE:To purify the titled compound useful as an addition agent for a resins, by treating a dibenzylidenesorbitol with hydroxylamine in the presence of a quaternary ammonium salt. CONSTITUTION:A dibenzylidenesorbitol is reated with hydroxylamine in the presence of a quaternary ammonium salt shown by the formula (R1)(R2)(R3)(R4) N<+>X<-> (R1-R4 are hydrocarbon such as 1-38C alkyl, phenyl, etc.; X is halogen soluble in water, or in methanol-water system) under slight heating, so that the dibenzylidenesorbitol is purified. A weight ratio of the quaternary ammonium salt to the dibenzylidenesorbitol is 1/1,000-1/100.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying dibenzylidene sorbitols.

φ Dibenzylidene sorbyl 1--ols, when added in small amounts to polyolefin resins, especially polypropylene, have the effect of improving the transparency of resins, and are useful in the fields of various containers that require transparency. This compound is suitable as an additive for resins.

However, since dibenzylidene sorbitol has an extremely strong gelling effect on organic solvents, it is difficult to completely remove (argyl)benzaldehyde, which is an unreacted raw material, during its production. For this reason, when this is added to a resin, the resin will have an odor and this will cause dibenzylidene solubi 1
・One major point in using the tool widely in the above application fields
(It had caused 9 damage.

Regarding the purification method of dibenzylidene sorbitol, regarding bis(alkylbenzylidene) sol di-1--
A method has been proposed (Japanese Unexamined Patent Publication No. 185287/1987) in which heat treatment is carried out at P l-1 7 or more in the coexistence of lower aliphatic terminone. Although it is said that the content of anole:1-ninolebensaldehyde in ~1-niolbenzaldehyde can be lowered to 10 to 30 ppm or less, the degree of purification was insufficient in terms of odor.

In addition, the present applicant has previously invented a method for producing dibenzylidenesols 1 to 1, which is characterized by treating dibenzylidenesorbitols with hydroxylamine,
The application (Japanese Patent Application No. 58-137645) was filed, but in this case, in a collectively preferred embodiment, it was necessary to use a methanol-water solvent as the solvent for the reaction.

The Ministry of the Invention has further researched an industrially advantageous method for purifying dibenzylidene sorbitol, and in a method for purifying dibenzylidene sorbitol by treating it with hydroxylamine, the hydroxylamine treatment is replaced with the addition of a quaternary ammonium salt. A method for purifying dibenzylidene sorbitol was invented.

In the present invention, the dibenzylidene sorbitols include dibenzylidene sorbitol itself and bis(P
Examples include bis(alkylbenzylidene) sorbitol such as -methylbenzylidene) sorbitol, bis(dimethylbenzylidene) sorbitol, and bis(trimethylbenzylidene) sorbitol.

Since hydroxylamine itself is an unstable compound, it is usually used in the form of a salt such as an acid such as hydrochloric acid or sulfuric acid.

Treatment of dibenzylidene sorbitol with hydroxylamine therefore neutralizes the acid of the hydroxylamine in a solvent, or liberates the hydroxylamine, but both are treated under alkaline conditions without causing hydrolysis of the acetal of dibenzylidene sorbitol. The method of contacting
It's simple.

In this case water can be used as solvent. Industrially, when recovering the solvent, it is desirable to use only water, and in that case the usefulness of the present invention increases, but it is preferable to use only water as described below. A small amount of lower alcohol such as methanol may be added in order to appropriately adjust the phase separation of the dibenzylidene sorbitol phase and the phase contact. That is, by adding alcohol, it is possible to cause a shift of 1 to 1 on the phase contact side (dispersion side).

The quaternary ammonium salt preferred in the present invention has the general formula (R+
) (R2) (R3) (R4) N" It is compatible with water or methanol-water systems.

In cases where R1-R1 has a small number of carbon atoms, such as Te1-ramedel ammonium chloride, the aqueous layer and dibenzylidene sorbitol tend to phase separate, requiring strong stirring, but the purification effect is large and R1 -R1 having 3 to 10 carbon atoms is preferable, for example, in the case of Te1-butylammonium bromide, the aqueous layer and dibenzylidene sorbitol can be separated well and the purification effect is also large. When the number of carbon atoms in R1-R4 exceeds 8, the dibenzylidene sorbyl compounds tend to be dispersed in a syrupy state in the aqueous phase, so if too much is used, separation of the two after purification tends to be difficult. , for example in the case of trimethylcedylammonium bromide. In the present invention, it is possible to use one type of ammonium salt, but it is also possible to use a lower ammonium salt that easily undergoes phase separation and a higher ammonium salt that disperses and is difficult to phase separate.

The amount of hydroxylamine salt used in the present invention (δ) is equimolar to several times that of the alkyl)benzaldehyde contained in dibenzylidene sorbitol before purification, and the quaternary ammonium salinity is: In order to promote the purification reaction, young [-Details of the present invention will be shown in Examples below, but in the following, 6-stage evaluation method odor melon is evaluated by several panelists as 6-stage, i.e., 〇 -Odorless.

1- There is a slight odor that I can't tell what it is.

2-It smells so bad that you can barely tell what's inside.

3 - Easily perceived odor.

4-It smells strongly.

5-It smells even stronger.

The value is the average of the evaluations.

Example 1 Hydroxylamine W in a flask? Bi salt 0,!
+ Dissolve g in water of Ukezume and add carbonic acid to it]・Lium o
, zg to neutralize. Add to this 0.30Q of Teller butylammonium chloride and 10.0Q of water. (Add 7 to J, mix well, then add bis(P-methylbenzylidene)
Add sorbitol io and gg and stir until well dispersed into a milky or creamy mixture.

After stirring this under reflux for 10 hours, 11 parts of water are added, it is filtered and washed twice with water and covered.

The resulting cake is dried in an 85° C. oven for 6 hours.

There was virtually no loss of bis(P-methylbenzylidene) turgotol by this treatment. The odor intensity according to the 6-level evaluation method was 0 to 1.

0.3% by weight of the bis(P-methylbenzylidene) sorbyls obtained in this way were added to a polypropylene resin, and molded at a molding temperature of 250°C to a size of 10 cm x 10 cm and a thickness of 2.
When injection molded into a M11 plate shape, the molded product had almost no odor (odor O), no additives were deposited on the mold even after 20 shots, and there was no deterioration in the transparency of the molded product. Without,
It was equivalent to that of the first molded article of Comparative Example 1.

Comparative Example 1 The same commercially available bis<P-methylbenzylidene) sorbitol (odor strength 3) used in Example 1 was added to the same polypropylene as in Example 1 at Q, 3i'1 (i1%'14 L/
When the same plate-shaped molded product was obtained under the same conditions as in Example 1, the molded product had an odor (smelling level 2) and had a 10% odor.
The transparency of the molded product is lower than the shot level.

Does the mold after injection molding contain additives? 1 was recognized.

As described above, according to the present invention, it is possible to very easily purify dibenzylidene sorbitol and remove its odor, and therefore, it is possible to eliminate the odor of polyurethane resin using it, and A great effect can be achieved by eliminating the bleed of additives used in molding.

Example 2 Hydroxylamine hydrochloride 1.0 to 150 parts of water! Melt I and add 1.39 ml of helium carbonate (melt).

On the other hand, put 22.40 of bis(P-methyl-benzylidene) sorbyl in an autoclave, and add 10.
Add 10 g of stearyl 1-limebluammonium chloride to a mixture of 40 d of NFL water and mix well. To this is added an aqueous solution containing the above hydroxylamine hydrochloride and lithium carbonate.

Close the autoclave and add 1 with stirring at 500 ppm.
Heat to 00°C and react for 8 hours.

After cold IA, take out the contents into a beaker, add 1 g of water, stir well, strain, and wash twice with water. +
Dry the baked cake in an 85°C oven for 6 hours.

There was virtually no loss of bis(P-methylbenzylidene) sorbitol due to this treatment. Moreover, after the treatment, the odor was no longer felt.

Example 3 Dissolve 1.0 g of hydroxylamine salt (1) in 150+ i of water, add 1 to 1.3 g of lithium carbonate, and dissolve.

On the other hand, a solution of 22.4 g of bis(P-methylbenzylidene) sorbyl 1--1 dissolved in O-1-crepe, and 0.60 g of tetramethylammonium chloride and 0.050 g of cetyl trimedelammonium chloride dissolved in 50 ml of water. Add J:<Mix. To this is added an aqueous solution prepared by dissolving the above hydroxylamine hydrochloric acid j711i and alium carbonate.

Close the autoclave and stir at 5QQ rpm.
Heat to 00°C and allow to react for 8 hours.

Cool, take out the contents into a beaker, add 1Q of water and dry.

The actual loss of bis(P-methylbenzylidene) sorbyl by this treatment was 1 nl. Further, no odor was detected after the treatment.

Patent applicant: Showa Denko Co., Ltd.

Claims (1)

[Claims] A method for purifying dibenzylidene sorbitol, characterized by treating dibenzylidene sorbitol with human[)xylamine in the coexistence of a quaternary ammonium salt, 1