JPH02160753A - Production of cyano-group containing (meth)acrylic acid ester - Google Patents

Abstract

PURPOSE:To obtain the title compound with inhibition of side-reactions in a shortened reaction time by effecting dehydrative esterification reaction between a ring-opening adduct between a cyano-substituted alkyl alcohol and epsilon- caprolactone and (meth)acrylic acid in the presence of a strong acid ion- exchange resin. CONSTITUTION:An epsilon-caprolactone adduct from a cyano-substituted alkyl alcohol of formula I (R<1> is a cyano-substituted alkyl; n is 1 to 10) is allowed to react with acrylic acid or methacrylic acid in the presence of a porous type or high porous type strong acid ion exchange resin in a solvent such as n-hexane using a polymerization inhibitor such as hydroquinone at 70 to 120 deg.C to give the objective compound of formula II (R<2> is H, methyl). The subject compound is homo-polymerized or co-polymerized to give polymers having excellent oil or fuel resistance due to the cyano groups and flexibility and resistance to chemicals due to the ring-opening parts of epsilon-caprolactone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a cyano group-containing (meth)acrylic ester. This cyano group-containing (meth)
By copolymerizing acrylic acid ester with its own center of gravity or with other 111 melon bodies, it has excellent characteristics such as oil resistance and fuel oil resistance due to the cyano group, and flexibility and chemical resistance due to the caprolactone ring opening. A polymer is obtained.

[Prior art] Generally, (meth)acrylic acid and alcohol (meth)
When synthesizing acrylic esters, a dehydration esterification reaction using a dehydration catalyst is used.

However, when the alcohol contains functional groups such as ester bonds and cyano groups in its structure, various side reactions occur during such dehydration and esterification reactions. The present inventors previously synthesized a cyano group-containing (meth)acrylic ester by a method using sulfuric acid as a dehydration esterification catalyst (Japanese Patent Application No.
(See No. 282177). However, since this method requires dehydration and esterification at high temperatures for a long time, side reactions such as transesterification and hydrolysis of cyano groups occur during one reaction.
There was a problem in that the molecular weight and acid value of the acrylic esters that were removed increased.

Problems to be Solved by the Invention One aspect of the present invention is that cyano group-containing (
The object of the present invention is to provide a catalyst system that can shorten the esterification reaction time and suppress side reactions that occur during esterification in a method for producing meth)acrylic acid ester.

[Means for Solving the Problems] The present invention provides a ring-opening adduct of ε-caprolactone of a cyano-substituted alkyl alcohol represented by the following formula (1) and (meth)
The present invention relates to a method for producing a cyano group-containing (meth)acrylic ester represented by the following formula (II), which is obtained by dehydration esterification with acrylic acid.

(Here, R1 is a cyano-substituted alkyl group, R2 is hydrogen or a methyl group, and n is an integer with a number average value of 1 to 10.)
When carrying out the dehydration esterification reaction of the compound represented by A cyano group-containing (meth)acrylic acid ester represented by the formula (In) is obtained by short-time dehydration and esterification, and side reactions such as transesterification and hydrolysis of the cyano group during dehydration and esterification are suppressed. I discovered that.

The compound represented by formula (1) used in the present invention is a
It is synthesized by a known method of ring-opening addition of monocaprolactone to a cyano-substituted alcohol in the presence of a catalyst such as a titanium compound, an organotin compound, a tin halide compound, or perchloric acid.

The cyano-substituted alcohols used here include ethylene cyanohydrin, l-cyanoethyl alcohol,
1-cyatuburobanol, 2-cyatuburobanol, 3
Examples include -cyatuburobanol, 4-diatubanol, 6-diatuhexanol, and ethylene cyanohydrin is particularly preferred.

The amount of the compound represented by formula (1) used in the present invention is from 0.05 to 0.05 to acrylic acid or methacrylic acid.
It is 2.0 times equivalent.

The strongly acidic ion exchange resin used as a catalyst in the present invention is a porous type or a heat-resistant high porous type resin 2, such as Amberlyst 15 manufactured by Rohm and Haas. Amberlyst 15B, Revachit 5PC-108°5PC-118 manufactured by Bayer, etc. are used. What is the amount of resin catalyst used?

per mole of the compound represented by formula (1).

The amount is 0.001 to 1 g, preferably 0.1 to 0.5 g. If the amount of catalyst is too small, the desired yield of acrylic ester will be reduced, and if the amount of catalyst is too large, side reactions during esterification will increase.

The reaction is carried out in a solvent commonly used in dehydration esterification reactions, such as n-hexane, cyclooxane, benzene, toluene, and the like.

The amount used is not particularly limited.

In the present invention, to prevent acrylic acid or methacrylic acid from polymerizing during dehydration and esterification.

Requires polymerization inhibitor or blowing air into the reaction solution.

Examples of the polymerization inhibitor used include hydroquinone, hydroquinone monomethyl ether, and catechol.

The reaction temperature is below the service limit temperature of the strongly acidic ion exchange resin, preferably 70 to 120°C.

By the method of the present invention, side reactions during dehydration and esterification can be suppressed in the synthesis of the cyano-substituted (meth)acrylic acid ester represented by formula (II).

[Examples] The present invention will be specifically explained below using Examples, but the scope of the present invention is not limited thereto.

Synthesis of ε-caprolactone ring-opening adduct of cyano-substituted alkyl alcohol of formula (1) 533.1 g (7.5 mol) of ethylene cyanohydrin and ε were placed in a 1,000 ml three-tube flask equipped with a stirrer and a condenser. - 171.2 g (1.5 mol) of caprolactone
was added and heated to 1' while stirring. temperature is 120
When it reached ℃.

0.5 g of stannous chloride was added, the temperature was maintained at 120° C., and the reaction was carried out under a nitrogen atmosphere for 1.5 hours. The conversion rates of ethylene cyanohydrin and E-caprolactone after the reaction were 9 and 8%, respectively.

It was 90.1%. Further, unreacted ethylene cyanohydrin and ε-caprolactone were removed from the reaction product by heating under reduced pressure to obtain a compound of Formula 1 (I). The molecular weight of the obtained compound was 202.3. This corresponds to a compound of formula (I) in which R1 is a cyanoethyl group and the number average value of n is 1.15. Here, the conversion rate of ethylene cyanohydrin and caprolactone was determined by using a gas chromatograph, and the molecular weight of the ring-opening adduct of ε-caprolactone was determined by the acetyl chloride-pyridine method (D, M, 5Illth and W, M, D.

11ryant, J, ^s, cbe+g, Soc
,,vol1.57. It was determined from the OH value measured according to Gl (1935)).

Example 1 313 g of the obtained compound of formula (1), 122 g of acrylic acid
315 g of g, l cyanide, 10 g of hydroquinone, and 90 g of dry resin Amberlyst 15 manufactured by Rohm & Haas (0.40 g).

The mixture was charged into a 1,000 ml Mitsuro flask equipped with a stirrer, a condenser, and a separator, and an esterification reaction was carried out.

The water produced by the reaction was distilled and condensed together with toluene, and the fraction was removed from the filament using a II vessel, and only toluene was returned to the reaction system. No more water was produced within 5 days after the start of the reaction, and the reaction was completed by cooling.

After reaction path γ, the catalyst was removed by decantation and the reaction solution was washed several times with a 5% aqueous sodium hydroxide solution and a 2096 aqueous sodium chloride solution to remove unreacted acrylic acid, the combination inhibitor, and unreacted ε- Remove caprolactone ring-opening adduct.

Toluene is removed under reduced pressure to obtain the target pale 1' of formula (II).
Four colors of cyano group QM acrylic esters were obtained.

The yield was 399g. The acid value of the obtained acrylic ester was 2.0×10 −5 equivalent fl/g.

i The molecular weight of the acrylic ester calculated from the quantitative determination of the terminal unsaturated group of the acrylic ester is 279.2.
Met. This corresponds to a compound of formula (II) in which R1 is a cyanethyl group, R2 is hydrogen, and the number average value of n is 1.35. here.

The acid value is the number of equivalents of alkali required to neutralize the acid contained in 1 g of the sample, and is measured by neutralization titration. In addition, the terminal unsaturated group can be quantified by the 1-morpholine method (for example, the method described in Section 225 of "Monomelon", Volume 2 of Molecular Experiments, edited by the Editorial Committee of Polymer Experiments, Japan Society of Polymer Science).
1llll was determined by

Example 2 As a catalyst, 104% of Levacitl-108 manufactured by Bayer was used as a catalyst.
Esterification was carried out in the same manner as in Example 1 using g (0.2 g of melon). The reaction time was 5 hours.

The yield of the obtained acrylic ester was 395 g. The acid value of the obtained acrylic ester is 1.5X10-
5 hitfilt/g.

The molecular weight was 274.9. In this formula (II), R1 is a cyanoethyl group and R2 is hydrogen.

This corresponds to a compound in which the number average value of n is 1.30.

Example 3 The same operation as in Example 1 was carried out except that 146 g of methacrylic acid was used instead of acrylic acid.

The reaction time was 5 hours. The yield of the obtained methacrylic ester was 410. The acid value of the obtained methacrylic ester was 3. The equivalent of lX10-5 was 7 g, and the molecular weight was 293.3. In this formula (II), R1 is a cyanoethyl group.

This corresponds to a compound in which R2 is a methyl group and the number average value of n is 1.35.

Comparative Example 1 The same operation as in Example 1 was performed except that 10 g of sulfuric acid was used as a catalyst. The reaction time H was 7 hours. The resulting reaction solution was neutralized with a 20% aqueous sodium hydroxide solution, and then washed several times with a 20% aqueous sodium chloride solution to carry out catalyst 1 polymerization. , the positive agent and unreacted ε-caprolactone ring-opening adduct were removed, and toluene was removed under reduced pressure to obtain the desired acrylic acid ester of formula (ff). The yield of the obtained acrylic ester was 450 g.

The acid value of the obtained acrylic ester is 3.6 x 10-4
The molecular weight was 307.8. This product has formula (II) in which R1 is a cyanoethyl group and R2
corresponds to a compound in which hydrogen is hydrogen and the number average value of n is 1.6.

Comparative Example 2 The same operation as in Comparative Example 1 was performed except that 9.5 g of sulfuric acid was used as a catalyst. The reaction time was 7 hours. The yield of the obtained acrylic ester was 441 g.

The acid value of the obtained acrylic ester was 2.7X1 (1'
equivalent/g, and the molecular weight was 302. In this formula (II), R is a cyanoethyl group, R2 is hydrogen, and the number of n! This corresponds to a compound with an average value of 1.55.

[Effects of the Invention] From the above results, it is clear that the method of the present invention suppresses the increase in acid value due to side reactions and the increase in n in formula (II).

Claims (2)

[Claims] (1) In the presence of a strongly acidic ion exchange resin, the following formula (1)
A cyano group-containing (meth) compound represented by the following formula (II), which is characterized by carrying out a dehydration esterification reaction between an ε-caprolactone ring-opening adduct of a cyano-substituted alkyl alcohol represented by the formula and acrylic acid or methacrylic acid. Production method of acrylic acid ester. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (Here, R^1 is a cyano-substituted alkyl group, R^2 is hydrogen or a methyl group, and n is an integer. , and the number average value is 1~
It is 10. ) (2) The method according to claim 1, wherein the strongly acidic ion exchange resin is a porous resin or a heat-resistant high porous resin.