JP2001106652A - Method for producing hydroxyalkyl (meth)acrylate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a high-quality hydroxyalkyl (meth) acrylate in high yield at a low cost while intactly using (meth)acrylic acid obtained by a vapor-phase oxidizing reaction. SOLUTION: This method for producing a hydroxyalkyl (meth)acrylate comprises bringing methacrylic acid prepared by a vapor-phase oxidizing reaction of a 4C compound or acrylic acid obtained by a vapor-phase oxidizing reaction of a 3C compound into contact with a primary amine in the liquid phase and then reacting the methacrylic acid or acrylic acid containing the primary amine with an alkylene oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing hydroxyalkyl (meth) acrylate, and more particularly to a method for producing high-quality hydroxyalkyl (meth) acrylate in a high yield while being an industrially simple method. .

[0002]

2. Description of the Related Art Generally, hydroxyalkyl (meth) acrylate is obtained by reacting (meth) acrylic acid with alkylene oxide in the presence of a catalyst, and purifying the resulting reaction solution by direct distillation to obtain a distillate thereof. Can be

In the industrial production of hydroxyalkyl (meth) acrylate, a method using a novel catalyst system or additive capable of synthesizing hydroxyalkyl (meth) acrylate with high selectivity, and a polymerization operation in a distillation operation after the reaction are used. Many techniques have been proposed, such as a method for avoiding troubles and a method for improving properties of distillation residues.

By the way, methacrylic acid and acrylic acid are industrially produced by gas phase oxidation of a compound having 4 carbon atoms, respectively.
And a gas phase oxidation reaction of a compound having 3 carbon atoms. Since the (meth) acrylic acid thus obtained contains many impurities, it is common to remove these impurities as much as possible and use it as high-quality (meth) acrylic acid.

[0005] The same applies to the case where hydroxyalkyl (meth) acrylate is synthesized by reacting (meth) acrylic acid with alkylene oxide.

[0006]

However, methacrylic acid obtained by a gas phase oxidation reaction of a compound having 4 carbon atoms or acrylic acid obtained by a gas phase oxidation reaction of a compound having 3 carbon atoms undergoes a high degree of purification. When used as a raw material and reacted with an alkylene oxide by a general method, the resulting hydroxyalkyl (meth) acrylate has extremely low polymerizability and is colored, and the quality is not satisfactory as a product. .

Therefore, methacrylic acid obtained by a gas phase oxidation reaction of a compound having 4 carbon atoms or acrylic acid obtained by a gas phase oxidation reaction of a compound having 3 carbon atoms is used as a raw material, whereby more economical and high quality products can be obtained. There has been a strong need for a method that can produce hydroxyalkyl (meth) acrylates.

Accordingly, an object of the present invention is to provide a method for producing a high-quality, high-quality hydroxyalkyl (meth) acrylate at a low cost using (meth) acrylic acid obtained by a gas phase oxidation reaction. And

[0009]

Means for Solving the Problems As a result of diligent studies, the present inventor has brought low-purity (meth) acrylic acid obtained by a gas phase oxidation reaction into contact with a primary amine in a liquid phase. The inventors have found that high-quality hydroxyalkyl (meth) acrylate can be obtained by using (meth) acrylic acid containing a primary amine as a raw material, and have reached the present invention.

That is, the present invention relates to a method in which methacrylic acid obtained by a gas phase oxidation reaction of a compound having 4 carbon atoms or acrylic acid obtained by a gas phase oxidation reaction of a compound having 3 carbon atoms is reacted with a primary amine and a liquid phase. And then reacting the methacrylic acid or acrylic acid containing the primary amine with an alkylene oxide.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The methacrylic acid used in the present invention is methacrylic acid obtained by a gas phase oxidation reaction of a compound having 4 carbon atoms. For example, isobutylene or t-butyl alcohol may be used as the compound having 4 carbon atoms. Methacrylic acid synthesized via methacrolein as an intermediate by a phase oxidation reaction, or as a compound having 4 carbon atoms, after isomerization and / or dehydrogenation of other saturated or unsaturated hydrocarbons, Methacrylic acid or the like synthesized by oxidation. Since these methacrylic acids have not been purified, their purity is not high, but usually they have a purity of 98% or more.

The acrylic acid used in the present invention is acrylic acid obtained by a gas phase oxidation reaction of a compound having 3 carbon atoms, and acrylic acid synthesized by a gas phase oxidation reaction using, for example, propylene as a compound having 3 carbon atoms. Is an acid. Since these acrylic acids have not been purified, their purity is not high, but usually they have a purity of 98% or more.

The primary amine used in the present invention may be either an aliphatic amine or an aromatic amine, and includes amines having a plurality of amine groups in one molecule. For example, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, t-butylamine, hydrazine, phenylhydrazine, monoethanolamine, 1,
Examples thereof include 6-hexanediamine, hydroxylamine hydrochloride, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, aniline, benzylamine, phenethylamine, anisidine, toluidine, and phenylenediamine.

The contact between the (meth) acrylic acid obtained by the gas phase oxidation reaction and the amine is performed in a liquid phase. As a contacting method, for example, a method of adding an amine compound to (meth) acrylic acid, heating the mixture to a predetermined temperature, preferably stirring the mixture, and holding the mixture for a predetermined time while blowing air is used.

The processing temperature at the time of contact is 20 to 150
C., preferably from 80 to 140.degree. C., and the treatment time is preferably from 10 minutes to 20 hours, particularly preferably from 1 hour to 10 hours. In addition, when performing this treatment, it can be usually carried out without adding a polymerization inhibitor, but under more severe conditions, for the purpose of performing more stable treatment, an appropriate polymerization inhibitor is added. You may go, especially
Performing the treatment in the presence of air is effective for preventing polymerization.

The amount of the primary amine to be added is 0.0005 to 0.2 equivalent, particularly 0.005 to (meth) acrylic acid.
A range of 1 to 0.1 equivalent is preferred.

Next, after such a contact treatment with a primary amine, a treatment solution containing a primary amine and (meth) acrylic acid may be used as it is when used for the next reaction with an alkylene oxide. Alternatively, if necessary, it may be used after purification by simple distillation or the like. In the present invention, from the viewpoint of simplifying the process, it is preferable to use it as it is, and it is more preferable to use a simple method as much as possible even when performing purification such as distillation. In addition, when the primary amine is contained in (meth) acrylic acid, the reaction with the next alkylene oxide is rather advantageous as described later.

The alkylene oxide used in the reaction with the (meth) acrylic acid thus treated is generally of a low molecular weight since the target hydroxyalkyl (meth) acrylate is obtained by distillation. And those having up to 4 carbon atoms are preferred. Specifically, ethylene oxide, propylene oxide, 1,
Examples thereof include 2-butylene oxide and 2,3-butylene oxide.

Numerous catalysts have been proposed for the reaction between (meth) acrylic acid and alkylene oxides, and amines are known to have a catalytic action. Therefore, by appropriately selecting the primary amines and using the liquid containing the primary amine as it is after the contact treatment, the reaction with the alkylene oxide can be carried out, especially without adding a new catalyst. It is possible. However, in order to obtain a high-quality hydroxyalkyl (meth) acrylate with high reactivity and high selectivity and high yield, it is necessary to use an effective catalyst when reacting with alkylene oxide. It is preferable to newly add.
It is preferable to use a metal compound as the catalyst,
In particular, a compound containing at least one metal selected from the group consisting of iron, aluminum, chromium, lithium, zinc, cadmium, niobium, and ruthenium is preferable.

For such a metal compound catalyst, the primary amine functions as a cocatalyst, and the reaction rate becomes faster and the control of by-products becomes easier as compared with the case where no primary amine is added. There are advantages such as. Accordingly, it is preferable to appropriately set the type and amount of the primary amine used in the contact treatment and the treatment conditions, depending on the catalyst newly added for the reaction with the alkylene oxide.

As the metal compound catalyst, for example, nitrates, hydrochlorides, acetates, sulfates, organic acid salts and the like of the respective metals are used, and commercially available products may be used as they are, but they can be used as reaction raw materials by a known method. It can be easily prepared using an inorganic acid or an organic acid.

The reaction between (meth) acrylic acid and alkylene oxide is carried out under stirring in order to obtain a suitable reaction rate.
In general, the heating is performed under pressure, and for example, when ethylene oxide is used as the alkylene oxide, 3
At 0-120 ° C, preferably 60-90 ° C, at a pressure of 0.
The reaction is carried out at a pressure of from 0.5 to 1 MPa, preferably from 0.2 to 0.5 MPa. Depending on the reaction temperature, it is preferable to add an appropriate polymerization inhibitor if necessary.

After the contact treatment with the primary amine, the reaction with the alkylene oxide can be carried out in the same reactor.

After the reaction is completed, unreacted alkylene oxide is degassed and separated from the reaction solution under reduced pressure, and then the hydroxyalkyl (meth) acrylate product is obtained by distillation. At that time, if necessary,
It is preferable to add a polymerization inhibitor.

In the distillation, since the reaction catalyst is still present in the reaction solution to be subjected to the distillation, the reaction may proceed more than necessary during the distillation, and the hydroxyalkyl (meth) acrylate may not be polymerized. Because there is a risk of
The contact time between the reaction solution and the evaporative heat transfer surface is preferably as short as possible, and it is effective to use equipment such as a thin film evaporator.

[0026]

EXAMPLES Evaluation of the polymerizability and coloring of the obtained hydroxyalkyl (meth) acrylate was carried out as follows.

<Evaluation of Polymerizability> The polymerization induction period (IP) was measured as follows. 1) A test tube having an inner diameter of 20 mm and a depth of 200 mm is charged with 10.0 g of hydroxyalkyl methacrylate and 0.050 g of benzoyl peroxide.
Mix and dissolve for minutes. 2) Immediately after dissolution, a temperature sensor covered with a protective tube made of glass is put into the sample, and the test tube is fixed in a constant temperature water bath at 65 ° C. 3) At the same time, the temperature recording is started, and thereafter, the temperature rise due to heat generation indicating the start of polymerization in the sample is detected, and the time from the start of the measurement to the confirmation of the temperature rise is defined as IP (minutes).

<Evaluation of Coloring> The number of colors APHA indicating the degree of coloring of hydroxyalkyl methacrylate is determined according to JIS.
K 0071: Measured according to 1993 “Test method for chemical product color and sulfuric acid coloring”.

Hereinafter, the method of the present invention will be described with reference to examples, but the method of the present invention is not limited to these examples.

Example 1 First, as methacrylic acid,
Methacrylic acid (purity: 99.000) synthesized by a gas phase oxidation reaction of isobutylene, extracted with toluene, separated from the solvent, and distilled at a reflux ratio of 1 by a 10-stage Aldershaw distillation column.
2%).

Next, 861 parts by weight of the above methacrylic acid and 8.84 parts by weight of o-phenylenediamine (1.7 mol% based on methacrylic acid) were added to a 2-liter autoclave with a stirrer. The temperature was raised from room temperature to 125 ° C. over 1 hour in an oil bath while blowing a small amount of air into the mixture under stirring, and then maintained at 125 ° C. for 3 hours.

Thereafter, the autoclave is cooled in an ice bath,
At 30 ° C., 2.7 parts by weight of chromium acetate and 2.2 parts by weight of hydroquinone were added, and the autoclave was replaced with nitrogen.
28 parts by weight were added. 300 gauge pressure with nitrogen
After the pressure was increased to kPa, the temperature was gradually raised in an oil bath with stirring so that the temperature reached 75 ° C. in about 1 hour. Thereafter, the temperature of the reaction solution was maintained at 75 ° C. by heating and adjusting, and when the amount of residual methacrylic acid reached 0.5% by weight (reaction time: 7.0 hours).
The unreacted ethylene oxide was removed under reduced pressure while cooling the autoclave with a water bath.

After the temperature in the system reaches 30 ° C. at 2 kPa, 1
After maintaining the pressure for 5 minutes, the pressure was returned to normal pressure, and then 1290 parts by weight of the reaction solution was fed to the thin film evaporator at a constant flow rate, while performing distillation at a heat transfer surface temperature of 85 ° C. and a reduced pressure of 300 Pa, to thereby obtain a primary distillation distillate. 1025 parts by weight of the liquid was obtained, and the primary distillation residue was distilled again in the same manner to obtain 195 parts by weight of the secondary distillate. Therefore, the primary distillation distillate and the secondary distillation distillate were mixed to obtain 1220 parts by weight (yield 93.8%) of the product. The composition analysis result of the product was 97.0% by weight of 2-hydroxyethyl methacrylate, 0.2% by weight of methacrylic acid, 0.1% by weight of water, and 2.7% by weight of others.

The color number of the product was 10 or less in APHA, there was almost no coloring, and the IP value was 22 (min). It was confirmed that the product exhibited excellent polymerizability. The conditions and results are shown in Table 1 together with other examples.

The reaction after the reaction with ethylene oxide was similarly carried out using methacrylic acid (purity: 99.5%) derived from acetone cyanohydrin without any special treatment. The number of colors of the products obtained in exactly the same manner was APHA 10 or less, and the IP value was 23 (minutes). That is, according to the present invention, even when methacrylic acid obtained by a gas phase oxidation method is used, the same color number and IP value as methacrylic acid derived from acetone cyanohydrin by a simple contact treatment with a primary amine are used. Was found to be extremely advantageous industrially.

Comparative Example 1 The same methacrylic acid as in Example 1 was used, except that the treatment with o-phenylenediamine was not performed. As a result, the yield of the product was 1218 parts by weight (yield 93.6%), and the result of composition analysis of the product was 97% 2-hydroxyethyl methacrylate.
1% by weight, methacrylic acid 0.2% by weight, water 0.1% by weight, and other 2.6% by weight. At this time, the reaction time was 8.0 hours, and the time required for completing the reaction was longer than in Example 1. Product color number is APH
A100-150, strong coloring, IP value 225 (min)
And the polymerizability was extremely low.

[Examples 2 to 17] The results are shown in the same manner as in Example 1 except that the same methacrylic acid as in Example 1 was used, and only the type, amount and processing conditions of the primary amine were changed. It is shown in FIG. The amount of the primary amine added was indicated by an equivalent per amine group with respect to the methacrylic acid used.

[Examples 18 to 20] Example 1 was repeated except that the same methacrylic acid as in Example 1 was used and the type and amount of the catalyst shown in Table 2 were changed as the catalyst used in the reaction with ethylene oxide. Was performed in the same manner as described above. Table 1 shows the results.

Example 21 In a 2-liter autoclave equipped with a stirrer, 861 parts by weight of the same methacrylic acid and 6.0 parts by weight of ethylenediamine (2.0 moles based on methacrylic acid) were used. %), And while stirring, while blowing a small amount of air into the mixture, the temperature was raised from room temperature to 120 ° C. over 1 hour in an oil bath.
And maintained for 3 hours.

Thereafter, the autoclave is cooled in a water bath,
At 30 ° C., 2.7 parts by weight of chromium acetate, 2.8 parts by weight of hydroquinone monomethyl ether, and 864 parts by weight of 1,2-butylene oxide were added. After closing the autoclave, the system was purged with nitrogen and further pressurized to a gauge pressure of 300 kPa, and then gradually heated in an oil bath with stirring so as to reach 75 ° C. in about 1 hour. Thereafter, the temperature of the reaction solution was maintained at 75 ° C. by controlling the heating, and when the amount of the remaining methacrylic acid reached 0.5% by weight (reaction time: 8.5 hours), the autoclave was cooled in a water bath under reduced pressure. Then, unreacted 1,2-butylene oxide was removed.

After the temperature in the system reaches 30 ° C. at 2 kPa, 1
After maintaining the pressure for 5 minutes, the pressure was returned to normal pressure, and then 1570 parts by weight of the reaction liquid was distilled at a heat transfer surface temperature of 100 ° C. and a reduced pressure of 300 Pa while supplying 1570 parts by weight of the reaction liquid to the thin film evaporator. Then, the primary distillation residue was again distilled in the same manner to obtain 156 parts by weight of a secondary distillation distillate. Therefore, the primary distillation distillate and the secondary distillation distillate were mixed to obtain 1431 parts by weight (yield 90.6%) of the product.
The composition analysis result of the product was 97.9% by weight of 2-hydroxybutyl methacrylate, 0.3% by weight of methacrylic acid, 0.1% by weight of water, and 1.7% by weight of others. The color number of the product was APHA 15, and the IP value was 32 (minutes).

Comparative Example 2 The same procedure as in Example 21 was carried out except that the same methacrylic acid as in Example 21 was used, and the treatment with ethylenediamine was not carried out. As a result, the yield of the product was 1445 parts by weight (yield: 91 2.5%)
-Hydroxybutyl methacrylate has a purity of 98.1%
Met. At this time, the reaction time was 9.5 hours, and the time required to complete the reaction was longer than that in Example 21. The number of colors of this product is 100-150 APHA.
And the IP value was 258 (minutes).

Comparative Example 3 The same methacrylic acid as in Example 15 was used, and the contact treatment with ethylenediamine was not performed. However, 6.0 parts by weight of ethylenediamine was added to the reaction between ethylene oxide and methacrylic acid (to methacrylic acid). 2.0 mol%), and the reaction was carried out exactly as in Example 15 except for that. The amount of residual methacrylic acid is 0.
The time to reach 5% by weight (reaction time: 7.0 hours) is exactly the same as in Example 15, and the product yield of 2-hydroxyethyl methacrylate obtained by thin-film distillation is 9
1.0% and the purity was 97.5%. However, the number of colors of the product was APHA 20-50, and the IP value was 180 (minutes).

Table 1 summarizes the results of the above Examples and Comparative Examples.

[0045]

[Table 1] (HAMA: hydroxyalkyl (meth) acrylate in the table)

[0046]

[Table 2]

[0047]

According to the present invention, a high-quality hydroxyalkyl (meth) acrylate can be produced at a high yield at a low cost using (meth) acrylic acid obtained by a gas phase oxidation reaction.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 67/60 C07C 67/60 69/54 69/54 Z (72) Inventor Kazutaka Inoue Konan, Minato-ku, Tokyo 1-6-1, Mitsubishi Rayon Co., Ltd. (72) Inventor Yukio Tanaka 18-8 Katayamacho, Kashiwara-shi, Osaka Osaka Organic Chemicals Co., Ltd. (72) Inventor Teruo Tani Katayama, Kashiwara-shi, Osaka 18-8, Osaka Organic Chemicals Co., Ltd. F-term (reference) 4H006 AA02 AC48 AD11 AD30 AD33 AD41 BA03 BA07 BA09 BA12 BA14 BA19 BA23 BA32 BA34 BA36 BA37 BA50 BA51 BA94 BC10 BC19 BC34 BC51 BT12 KA19 4H039 CA60 CA66 CF90

Claims (5)

[Claims] 1. A methacrylic acid obtained by a gas phase oxidation reaction of a compound having 4 carbon atoms or an acrylic acid obtained by a gas phase oxidation reaction of a compound having 3 carbon atoms is contacted with a primary amine in a liquid phase. And then reacting the methacrylic acid or acrylic acid containing the primary amine with an alkylene oxide to produce a hydroxyalkyl (meth) acrylate. 2. A method according to claim 1, wherein the methacrylic acid obtained by the gas-phase oxidation reaction of the compound having 4 carbon atoms is obtained by using gas-phase oxidation reaction of isobutylene or t-butyl alcohol as the compound having 4 carbon atoms to convert methacrolein into an intermediate. Is a methacrylic acid that is synthesized via a carbon dioxide, or a compound having 4 carbon atoms, and is synthesized by performing a gas phase oxidation reaction after isomerization and / or dehydrogenation of other saturated or unsaturated hydrocarbons. The method for producing a hydroxyalkyl methacrylate according to claim 1, which is methacrylic acid. 3. The primary amine is methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, t-butylamine, hydrazine, phenylhydrazine, monoethanolamine, 1,6-hexane. Diamine, hydroxylamine hydrochloride, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, aniline, benzylamine, phenethylamine, anisidine, toluidine, o-phenylenediamine, p-
The method for producing a hydroxyalkyl (meth) acrylate according to claim 1 or 2, wherein the method is at least one selected from the group consisting of phenylenediamine and m-phenylenediamine. 4. The hydroxyalkyl (meth) acrylate according to claim 1, wherein a metal compound is used as a catalyst when reacting the methacrylic acid or acrylic acid with the alkylene oxide. Manufacturing method. 5. The metal compound used as a catalyst,
5. The production of a hydroxyalkyl (meth) acrylate according to claim 4, wherein the compound is a compound containing at least one metal selected from the group consisting of iron, aluminum, chromium, lithium, zinc, cadmium, niobium, and ruthenium. Method.