JPS5821939B2 - Manufacturing method of rosin allyl ester - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing rosin allyl ester.

When dehydrated esterification of rosin and allyl alcohol is attempted using an acid catalyst such as sulfuric acid, which is conventionally used in the production of rosin allyl ester, the rosin is converted into a resin and no rosin allyl ester is produced.

This is thought to be due to polymerization of rosin caused by sulfuric acid.

In addition, for dehydration and esterification without using a sulfuric acid catalyst, approximately 25
High temperatures of 0°C are required and must be operated under pressure.

Further, at a high temperature of about 250°C, thermal polymerization of allyl groups occurs, and the yield of rosin allyl ester is extremely low.

On the other hand, a method is known in which an allyl halide and a common alkali metal salt of a carboxylic acid are reacted in the presence of a cuprous halide to synthesize a common allyl carboxylic acid ester in a good yield.

However, this reaction was attempted with tertiary carboxylic acids, such as in the case of rosin, in which all carbons to which carboxyl groups are bonded are bonded to other carbons, and reactivity is inhibited due to steric hindrance. I have never been.

Since the carboxyl group of rosin is tertiary, it is difficult to react at low temperatures and requires a high temperature of about 250°C, and the ester produced is difficult to hydrolyze and requires harsh conditions, which makes it different from ordinary carboxylic acids. It is known that the reactivity is significantly different.

Based on this conventional wisdom, the present inventors reacted an alkali metal salt of rosin with an allyl halide using a cuprous compound as a catalyst, and unexpectedly found that the reaction temperature was 150°C or lower and the reaction temperature was high under atmospheric pressure. The present invention was based on the discovery that pure rosin allyl ester could be obtained.

That is, in the present invention, when producing rosin allyl ester from an aqueous solution of an alkali metal salt of rosin and an allyl halide, cuprous chloride or cuprous oxide is added as a catalyst by weight of 3 to 10 to the rosin, and the atmospheric pressure is Below is a method for producing rosin allyl ester, which is characterized in that the reaction is carried out at 40°C to 45°C in the early stage of the reaction, and the reaction is carried out at 90°C to 100°C in the latter stage of the reaction.

The rosins used in the present invention include gum rosin, wood rosin, tall oil rosin, and modified rosins obtained by modifying these rosins by maleation, hydrogenation, disproportionation, or polymerization.

Rosin is composed of diterpene resin acids and a small amount of neutral components, and the resin acids are a mixture of monovalent carboxylic acids having hydrophenanthrene nuclei represented by C0, H2, and C00H.

The carboxyl group is bonded to a tertiary carbon and has lower reactivity than a normal carboxyl group.

The alkali metal salt of rosin is also called rosin soap, and can be prepared by any method such as heating and dissolving rosin with an aqueous solution of an alkali metal salt such as lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, or potassium carbonate. The alkali metal salt aqueous solution of rosin thus obtained can also be used directly.

The allyl halides used in the present invention include allyl chloride, allyl bromide, allyl iodide, and methallyl chloride.

3- such as crotyl chloride, 1,3-dichloropropene
It is a halogeno-1-propene compound.

Since allyl chloride is an industrial raw material, it is economically advantageous.

The amount of allyl halide used is preferably a stoichiometric or higher proportion to the carboxyl group of the rosin.

That is, the operation is carried out using 1.2 to 3 moles of allyl halide per carboxyl group in the rosin.

A portion of the excess allyl halide is hydrolyzed and the remainder is recovered.

In order to obtain ester in high yield, the pH of the reaction solution should be 4 to 4.
It is desirable to keep it in the range of 8, preferably in the range of 6-8.

The pH can be adjusted by any method such as adding an aqueous solution of an alkaline substance such as sodium hydroxide, sodium carbonate, etc., or using a buffer substance such as sodium bicarbonate, carbonate, etc. at the beginning of the reaction. It will be done.

In the present invention, cuprous chloride or cuprous oxide is used as a catalyst.

The appropriate amount of catalyst to be used is 3 to 10 inches (by weight) based on the rosin.

The reaction can be carried out under atmospheric pressure by a two-stage reaction method in which the reaction is carried out at a low temperature of about 40° C. in the early stage of the reaction and at a high temperature of about 100° C. in the latter half of the reaction.

A low reaction temperature makes it difficult for the reaction to proceed, while an excessively high temperature promotes side reactions, which is not preferred.

The reaction product is separated from the aqueous phase, and excess allyl halide and secondary volatile components are removed by distillation or the like to yield rosin allyl ester as a residue.

Rosin allyl ester can also be purified by methods such as vacuum distillation.

The rosin allyl ester thus obtained is used as a rosin methyl ester, a softener for rubbers, a viscosity reducer, a cold resistance imparting agent, etc., and is used in other fields that utilize the polymerizability of the allyl group. It is useful in

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

Example 1 Wood rosin (softening point 73°C, acid value 163) was placed in a reaction vessel equipped with a stirrer, reflux condenser, pH meter and thermometer.
344. ! i' and 10 heavy sodium hydroxide aqueous solution 4
00g was added, and the mixture was heated and stirred at about 90°C until all of the rosin was dissolved.

After cooling this to 30°C, add 10g of cuprous chloride (3 parts by weight to wood rosin) copper powder and 50g of sodium carbonate hydroxide, heat to 45°C, and add 153g of allyl chloride for about 1 hour while stirring. Added with.

After the addition was completed, the temperature was raised to 90°C in the first hour, and the temperature was increased to 90°C.
.

It was maintained at pH 7.5 for 1 hour.

After cooling the reaction solution to room temperature, the organic layer was separated, and the organic matter in the aqueous layer was extracted with toluene. This and the organic layer were dried over anhydrous sodium carbonate and concentrated by distillation.
The volatile components were distilled off at 3 MHg for 1 hour to obtain 384 g of wood rosin allyl ester (acid value: 4, iodine value: 205) as a pale amber transparent liquid.

Example 2 The reaction and treatment were carried out in the same manner as in Example 1, except that 194 g of 15-weight maleated rosin (softening point: 110° C., acid value: 287) was used instead of wood rosin to obtain maleated rosin allyl ester as an amber transparent liquid. 234I was obtained.

This product had an acid value of 10 and an iodine value of 147.

Example 3 In the same reaction vessel as in Example 1, tall oil rosin (softening point 77
°C, acid value 185) 303. ! 400 I of aqueous sodium hydroxide solution by weight of 9 and 10 was added, and the mixture was heated and stirred at about 90° C. until the whole became uniform.

After cooling the mixture to 40°C, 15g of cuprous oxide (5 parts by weight relative to tall oil rosin) was added, and while stirring while keeping the temperature at 40°C, 153g of allyl chloride was added. ! i' was added over approximately 1 hour.

The temperature was then raised to 90°C in about 1 hour and kept at 90°C for 1 hour.

During this time, in order to maintain the pH of the reaction system at 6 to 7, a 20% by weight aqueous sodium hydroxide solution was added to adjust the pH.

The reaction solution was treated in the same manner as in Example 1 to obtain an amber transparent liquid tall oil rosin allyl ester (acid value 8, iodine value 21).
3) 34:l was obtained.

Example 4 Hydrogenated rosin (softening point 668°C,
Acid value 164) 341. ! 381 g of a pale amber transparent liquid hydrogenated rosin allyl ester (acid value 6) was obtained in the same manner as in Example 3 except that i/ was used.

Claims (1)

[Claims] 1. When producing rosin allyl ester from an aqueous solution of an alkali metal salt of rosin and an allyl halide, cuprous chloride or cuprous oxide is used as a catalyst at a rate of 3 to 10% relative to the rosin.
By weight, at the initial stage of the reaction under atmospheric pressure, the temperature is 40℃~
The reaction was carried out at 45°C, and in the latter stage of the reaction the temperature was increased to 90°C to 10°C.
A method for producing rosin allyl ester, characterized by carrying out the reaction at 0°C.