JPH0713038B2 - Process for producing methacrylic acid ester of alicyclic alcohol - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a methacrylic acid ester of an alicyclic alcohol.

(Prior Art) In the production of methacrylic acid ester, attention is paid to how to suppress the polymerization during the esterification reaction, but it is generally effective to add a polymerization inhibitor and blow air (oxygen). It is widely practiced by those skilled in the art. However, when a methacrylic acid ester of an alicyclic alcohol is produced, the alicyclic alcohol is easily oxidized to form a peroxide, and the raw material methyl methacrylate or the methacrylic acid ester of the product is polymerized. It is difficult to suppress the polymerization during the reaction by the method.

As a method for preventing polymerization during the production of methacrylic acid or acrylic acid ester of such alicyclic alcohol,
As disclosed in JP-A-58-213733, there is a method in which an organic sulfonic acid is added to an alicyclic alcohol and heat-treated, and then methacrylic acid or acrylic acid is added to carry out an esterification reaction.

Further, among alicyclic alcohols, there is a problem that remarkable coloration is likely to occur particularly during esterification of an alcohol having a tertiary carbon or an alicyclic group having a double bond. As a method for removing colored components by these reactions, Japanese Patent Laid-Open No. 56-
As disclosed in Japanese Patent No. 138142, there is a method of reacting in the presence of an acid catalyst and then adding an aliphatic hydrocarbon solvent to precipitate and remove a coloring component.

(Problems to be Solved by the Invention) However, in the method using a strong acid as a catalyst as disclosed in JP-A-58-213733, there is a side reaction in which the alicyclic structure part is ionically polymerized. In addition, there is a problem that the coloring property of the catalyst itself causes remarkable coloring during the reaction. This tendency is particularly remarkable in alcohols having an alicyclic group having a tertiary carbon or a double bond. Further, in the case of an alicyclic secondary or tertiary alcohol, there is a problem that alcohol is decomposed by causing intramolecular dehydration. Therefore, in the above publication, the acid is limited to organic sulfonic acid, but it is not possible to prevent intramolecular dehydration.

Further, in the method for removing the coloring component as disclosed in JP-A-56-138142, the productivity is deteriorated because the aliphatic hydrocarbon solvent which is several times or more the amount of the target ester compound is required. There is a problem.

As described above, the method of esterifying an alicyclic alcohol with methacrylic acid in the presence of an acid catalyst has problems in terms of purity and coloring of the obtained reaction solution.

Further, there is no known method for suppressing polymerization by a method of obtaining an ester compound by transesterification of such an alicyclic alcohol with methyl methacrylate. In general, when a methacrylic acid ester is synthesized by a transesterification reaction, a polymerization inhibitor is present for the purpose of preventing polymerization. Usually, the polymerization inhibitor used in the transesterification reaction is a methacrylic ester of an alicyclic alcohol. It is difficult to prevent polymerization during the synthesis of acid esters.

(Means for Solving the Problems) The present invention is characterized by treating an alicyclic alcohol with an alkaline substance and then performing a transesterification reaction with methyl methacrylate in the presence of the alkaline substance. To a method for producing a methacrylic acid ester.

In the present invention, the alicyclic alcohol is an alcohol having an alicyclic group in the molecule, for example, bicyclo [2.2.
1] Hept-2-en-5-ol, bicyclo [2.2.1]
Heptane-2-ol, cyclohexane monomethylol, cyclohexane dimethylol, bicyclo [2.2.
1] Hept-2-en-5-ylmethanol, bicyclo [2.2.1] heptane-2-ylmethanol, 1-adamantanol, 2-adamantanol, tricyclo [5.2.10]
^2,6 ] deca-3-en-8 (or 9) -ol, tricyclo [5.2.1.0 ^2,6 ] decane-8-ol, tricyclo [5.2.1.0 ^2,6 ] decane-3 (or 4)- Ilmethanol, 3 (or 4), 8 (or 9) -bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane borneol, isoborneol, phenethyl alcohol, 2.2.5-trimethylcyclohexanol, menthol, ethylene Examples include glycol monodicyclopentenyl ether, propylene glycol monodicyclopentenyl ether, neopentyl glycol monodicyclopentenyl ether, and 1.6-hexanediol monodicyclopentenyl ether.

Among the alicyclic alcohols, alcohols having a tertiary carbon atom or a double bond in the alicyclic group are particularly liable to generate a peroxide by air oxidation. In particular, alcohols having both a tertiary carbon and a double bond in the alicyclic group, eg dicyclopentadiene structure Alcohols are those which very easily undergo oxidation by air to give peroxides.

Such alicyclic alcohols themselves contain peroxides as impurities, and when left in the air, the amount of peroxides increases, and when air is further inhaled, the amount increases significantly. This peroxide is decomposed by contact treatment with an alkaline substance,
Unfavorable polymerization reaction can be suppressed.

Examples of the alkaline substance include metallic sodium, metallic potassium, metallic lithium, sodium hydride, potassium hydride, lithium hydride, butyl lithium, phenyl lithium, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium, potassium or lithium. Basic compounds such as methoxide, ethoxide, propoxide, or an alkoxide of the above alicyclic alcohol. From the viewpoint of handling, it is preferable to use a hydroxide or an alkoxide. These may be used after being dissolved or dispersed in a solvent such as alcohol such as methanol or ethanol.

The amount of alkaline substance used is based on the alicyclic alcohol.
It is preferably 0.01 to 5.0% by weight, and more preferably 0.05 to 2.0% by weight. If the amount of the alkaline substance is small, the effect of decomposing the peroxide cannot be obtained sufficiently, and if the amount is too large, there is no particular improvement in this effect. These alkaline substances may be added to the alicyclic alcohol in the first place for treatment and reaction, but may be additionally divided during the treatment or transesterification reaction.

The treatment of the alicyclic alcohol with the alkaline substance is preferably carried out in a reaction vessel equipped with an ordinary stirring device.
Alternatively, an alkaline substance can be added to the alicyclic alcohol storage container, but many alkaline substances are solid and are not easily dissolved in the alicyclic alcohol. For example, it is more efficient that the liquid is in a fluid state to some extent.

The treatment conditions differ depending on the type and amount of the alkaline substance used, but it is preferable to perform the treatment at a temperature of 0 to 120 ° C. The treatment time may be appropriately determined, but a range of 5 hours or less is sufficient. For example, when a metal alkali is used, the temperature is preferably low, and the treatment can be completed at a low temperature in a substantially short time. On the other hand, when an alkaline substance such as an alkali hydroxide which is difficult to dissolve in an alicyclic alcohol is used, solid-liquid contact is used, and therefore it may be preferable to heat or treat for a long time. However, in any case, the object can be achieved by gently stirring at room temperature (without special heating or cooling) for 1 minute to 1 hour. In addition, in an actual production facility, when adding methyl methacrylate after adding an alkaline substance to the alicyclic alcohol, it takes some time to prepare the methyl methacrylate. Immediately after the addition of
The above-mentioned treatment can also be substantially completed by carrying out the transesterification reaction described below.

If the alicyclic alcohol is treated with an alkaline substance and then the substance is not separated, the treatment liquid thus obtained can suppress the production of peroxide even after being stored for several days. Therefore, after the treatment, the treated liquid can be stored and then subjected to transesterification reaction with methyl methacrylate.

Since the alkaline substance functions as a catalyst for the transesterification reaction, it is possible to add methyl methacrylate to the treatment liquid to cause the transesterification reaction without separation from the treatment liquid after the treatment. If it is necessary to remove alkaline substances from the processing solution, neutralize with acid, wash with water,
The alkaline substance can be removed due to excess or the like.

In the transesterification reaction between alicyclic alcohol and methyl methacrylate, the alkaline substance is preferably present in an amount of 0.01 to 5.0% by weight based on the alicyclic alcohol, particularly 0.0
It is preferably present between 5 and 2.0% by weight. If the amount is too small, the transesterification reaction becomes slow, and if the amount is too large, there is no particular advantage.
After the reaction, a complicated operation is required to remove the alkaline substance.

When the alkaline substance is not separated from the treatment liquid, it is not necessary to newly add the alkaline substance during the transesterification reaction, and the alkaline substance is appropriately added so that the alkaline substance is present in the transesterification reaction. You may add.

The above-mentioned alkaline substance can be used as the alkaline substance to be present in the transesterification reaction, and the alkaline substance has a function of suppressing the generation of peroxide during the transesterification reaction.

In the transesterification reaction, methyl methacrylate is preferably used in the range of 2 to 5 mol per 1 equivalent of hydroxyl group of the alicyclic alcohol. If the amount of methyl methacrylate is too small, the reaction becomes slow and unreacted alicyclic alcohol is likely to remain. On the other hand, if the amount of methyl methacrylate is too large, the productivity will be poor, and it will take a long time to recover the excess methyl methacrylate after the reaction.

In the present invention, it is preferable that a polymerization inhibitor is present during the transesterification reaction. As the polymerization inhibitor, known polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, parabenzoquinone, 2.5-diphenylparabenzoquinone, phenothiazine, diphenylamine, phenyl-β-naphthylamine and methylene blue can be used. . The amount of these polymerization inhibitors used is 15 to 10,000 with respect to the alicyclic alcohol.
ppm is preferable, and 50 to 1,000 ppm is particularly preferable. If the amount is too small, the effect of preventing polymerization by using the polymerization inhibitor may not always be sufficient, and if the amount is too large, adverse effects such as inhibition of polymerization when the product in which the polymerization inhibitor is not removed are subjected to polymerization May be affected.
Note that hydroquinone monomethyl ether and phenothiazine are particularly preferable in that the resulting reaction liquid is less colored. In the present invention, it is preferable to blow a small amount of molecular oxygen during the reaction to prevent polymerization of the reaction solution. Molecular oxygen is preferably used in a diluted form such as air. Blow-in of molecular oxygen is also preferable in the case of using a rectification column as described later, in order to prevent the polymerization of methyl methacrylate existing as a gas or a fluid in the rectification column. The amount of molecular oxygen used depends on the shape of the reactor and the stirring power, but
5 to 500 ml / mi per 1 mol of alicyclic alcohol charged
Blow at a speed of n (25 to 2,500 ml / min as air).

The transesterification reaction is preferably carried out at 60 to 130 ° C under normal pressure or reduced pressure.

Further, as a reaction mode of the transesterification reaction, a method generally known by those skilled in the art for producing a methacrylic acid ester by transesterification of methyl methacrylate and alcohol can be adopted. In this method, in order to increase the conversion rate of the raw material alcohol, it is preferable to carry out the synthesis while distilling methanol out of the system by azeotropic distillation of by-produced methanol and methyl methacrylate.

Therefore, as the reaction apparatus, it is preferable to use a batch reaction tank equipped with a rectification column. In this case, the transesterification reaction is performed as follows, for example. That is, when the reaction is carried out at normal pressure, the methanol and methyl methacrylate that are produced will boil when the temperature of the reaction solution rises to about 100 ° C. In the rectification column, the reflux ratio was controlled so that the overhead temperature was 64 ° C, which is the azeotropic point of methanol and methyl methacrylate, and the amount of methyl methacrylate distilled out of the system was minimized. The transesterification reaction is completed while removing methanol outside the system as an azeotrope with methyl methacrylate. In this case, the reaction solution temperature rises to about 110 to 125 ° C near the end of the reaction, and the column top temperature approaches 100 ° C. That is, since the azeotropic composition of methanol and methyl methacrylate deviates, it is preferable to increase the reflux ratio to reduce the loss of methyl methacrylate.

On the other hand, when methanol stays in the reaction system at a high concentration for a long time, a by-product in which methanol is added to the unsaturated bond of methacrylic acid ester is generated. It is also necessary to promptly distill out of the system.

Here, a large amount of methyl methacrylate liquid and gas vaporized from the reaction tank exist in the rectification column. However, even if the polymerization inhibitor is charged in the reaction tank, it does not easily vaporize, and thus there is almost no polymerization inhibitor in the rectification column, and methyl methacrylate may polymerize. Therefore, as described above, a method in which molecular oxygen (eg, air) is introduced into the reaction vessel so that molecular oxygen coexists in the rectification column, or a polymerization inhibitor is added to the reflux liquid returned from the top of the rectification column to the column. Is preferably added.

The reaction solution obtained by the transesterification reaction is often composed of a solution containing methyl methacrylate, a methacrylic acid ester of the product, a small amount of the starting alcohol and a polymerization inhibitor, and an insoluble material such as an alkaline substance. .

To obtain the product by substantially isolating the product methacrylic acid ester from this reaction solution, a method widely used in the art can be used. That is, methyl methacrylate may be distilled off as it is from the reaction solution, and subsequently the methacrylic acid ester of the desired product may be obtained by distillation (usually by vacuum distillation). Alternatively, the reaction solution may be washed with water or washed with water to remove alkaline substances (catalysts) and the like, and then methyl methacrylate may be distilled off to obtain a product. In some cases, the product may be further purified by distillation. Good. Also,
The product may be obtained by removing the methyl methacrylate from the reaction solution and then removing the alkaline substance (catalyst) or the like by washing with water or washing with water, and in this case also, the product may be further purified by distillation. It should be noted that the use of an alkaline substance such as lithium hydroxide is convenient because it can be easily removed by filtration.

(Operation) As a result of further investigation on the behavior of the alicyclic alcohol, the present inventors have found out the following facts.

That is, the alicyclic alcohol itself contains peroxide as an impurity, and the peroxide increases when left in the air, and further the molecular oxygen (or air) is added.
Blow in significantly increases the amount. However, when this alcohol is contacted with an alkaline substance, this peroxide decomposes. Further, peroxide is not formed even if air is blown in under the temperature condition of the transesterification reaction in the presence of the alkaline substance and the polymerization inhibitor. Such an action shows a significant difference from the method described below.

After treatment with an alkaline substance to prepare a cycloaliphatic alcohol that does not contain peroxide, the alkaline substance is removed, and then a transesterification reaction is performed using a neutral catalyst such as titanium tetraisopropoxide or titanium tetrabutoxide. Then, when air is blown even in the presence of the polymerization inhibitor, peroxide is immediately formed, and subsequently polymerization is caused.

In addition, a method in which an alicyclic alcohol, methyl methacrylate and a polymerization inhibitor are charged in advance, and then an alkaline catalyst is added immediately before the start of the reaction, a considerable amount of peroxide has already been produced and This causes the formation of a polymer, and a small amount of the polymer is formed before the reaction.

When such an alicyclic alcohol is subjected to a transesterification reaction with methyl methacrylate using an acid catalyst such as paratoluenesulfonic acid or sulfuric acid, a side reaction occurs that produces a byproduct of intramolecular dehydration of the alicyclic alcohol. There are problems, and cycloaliphatic alcohols undergo ionic polymerization with acid catalysis, producing oligomer by-products and causing significant coloration.

(Example) An example of the present invention will be described.

In the following examples, the presence or absence of a polymer was determined and the peroxide content was measured by the following methods.

Judgment of presence or absence of formation of polymer A methanol solubility test was conducted. That is, 5 g of a sample and 15 g of methanol were placed in a test tube, and the presence or absence of insoluble matter (whether or not cloudy) was observed with the naked eye when thoroughly mixed by shaking to determine the presence or absence of a polymer.

Determination of peroxide content In a 250 ml Erlenmeyer flask with a corkscrew, add 100 ml of methyl alcohol, 5 ml of 10% potassium thiocyanate solution and 2 ml of 1: 1 sulfuric acid. Then add 10 ml of 1/10 N ferrous ammonium sulfate solution with a pipette. Add a blob of solid carbonic acid to it,
Replace the air in the flask with carbon dioxide, grease and let stand for 15 minutes. Carefully add 1 / 50N Titanium Chloride solution until the pink color of ferric iron disappears. Next, add a small block of solid carbonic acid to the Erlenmeyer flask, inactivate the flask, and add a 25 ml sample with a pipette.

After mixing well, grease it and leave it in the dark. This is carefully titrated with 1 / 50N titanium chloride solution until the pink color disappears. Near the end of the titration, add one drop at a time to allow sufficient reaction with titanium chloride.

The peroxide content c (weight% in terms of hydrogen peroxide) is calculated by the following formula.

Where A: Titration of 1 / 50N titanium chloride solution required to reduce ferric iron produced by peroxide in sample (ml) F: 1 / 50N titanium chloride solution Titer G: specific gravity of the sample 1: 1 sulfuric acid is a mixture of water and concentrated sulfuric acid at a volume ratio of 1: 1.
In addition, the titer of 1/50 N titanium chloride solution was determined by adding 50 ml of distilled water, 15 ml of hydrochloric acid and 10 ml of 10% potassium thiocyanate solution to a 250 ml Erlenmeyer flask equipped with a spiral wire, and further adding 10 ml of iron standard solution with a pipette. Add a small lump of solid carbonic acid, inactivate the flask with carbon dioxide gas, titrate with 1 / 50N titanium chloride solution until the pink color disappears, and calculate with the following formula.

Here A: 1 / 50N required to reduce 10 ml of iron standard solution
Titre chloride first titanium solution (ml) In addition, the iron standard solutions dissolved ferrous ammonium (Mohr's salt) _{[FeSO 4 (NH 4) 2 SO} 4 · 6H 2 O ] 35.11g sulfate distilled water 400ml Then add 25 ml of concentrated sulfuric acid and warm to 50-60 ° C.
Adjust by adding potassium permanganate solution until ferrous ions are oxidized to ferric ions, and then make up to 1000 ml with distilled water. This solution contains 0.005 g ferric ion in 1 ml.

Example 1 A 14-necked flask equipped with a stirrer, a thermometer, an air inlet tube and a rectification column (15 stages) was charged with tricyclo [5.2.1.0 ^2,6 ].
Deca-3-en-8 or 9-ol 150 g [ 1 mol, peroxide content 48 ppm (H ₂ O ₂ conversion)] was charged, and 1.5 g of granular sodium hydroxide was added to this, and the temperature was 30 ° C.
After gently stirring for 1 hour, the peroxide was not detected when measured. Next, methyl methacrylate
350 g (3.5 mol) and hydroquinone monomethyl ether
It was charged to 0.11 g and heated while introducing air into the reaction solution at a rate of 50 ml / min. When the temperature of the reaction solution increased to about 100 ℃, the azeotrope of methanol and methyl methacrylate began to flow out from the top of the rectification column, so the reflux ratio was set to 2 and the temperature at the top of the column was 64 to 66 ℃. The reaction was carried out while distilling off methanol as an azeotrope with methyl methacrylate so as to fall within the range.

In addition, 0.5 g of granular sodium hydroxide was added to each of the first and second hours after the start of the reaction. Since the temperature at the top of the column started to rise to about 90 ° C from the time of reaction for 2.5 hours, the reflux ratio was gradually increased accordingly, and finally it was set to 10, and the reaction was continued for 1.5 hours. At this point, that is, when gas chromatographic analysis was carried out for 4 hours after the start of the reaction, the starting alcohol tricyclo [5.2.1.0 ^2,6 ]
The reaction was terminated because deca-3-en-8 or 9-ol was 0.15% (area%) with respect to the methacrylic acid ester of the alcohol as a product. No peroxide was detected in the reaction solution. Also, no polymer was formed.

Next, the reaction liquid temperature was set to 100 ° C, methyl methacrylate was distilled off while gradually lowering the pressure, and finally it was set to 40 mmHg, and when the methyl methacrylate content rate reached 0.15% by gas chromatography analysis. I stopped the concentration. Cool this concentrate to room temperature and use a glass Buchner funnel.
Toyo Paper 5B paper used Light yellow transparent liquid 21
0 g (no peroxide detected, no polymer) was obtained. When this liquid was analyzed by gas chromatography, the target tricyclo [5.2.1.0 ^2,6 ] deca-3-ene-8 or 9-
The purity of all methacrylic acid esters (area%, the same below) was 98.6%.

Example 2 A device similar to that of Example 1 was charged with 208 g of propylene glycol monodicyclopentenyl ether. 1 mol and a peroxide content of 63 ppm (converted to H ₂ O ₂ )] were added, and 1.0 g of 28% sodium methoxide-methanol solution was added thereto, and the mixture was stirred at 25 ° C. for 30 minutes. No peroxide was detected in the alcohol at this point. To this was charged 350 g (3.5 mol) of methyl methacrylate and 0.11 g of hydroquinone monomethyl ether, and the reaction was carried out in the same manner as in Example 1. In addition, 1 hour and 2 of reaction
At the hour, add 28% sodium methoxide-methanol solution
Added 1.0g each. After the reaction was completed, no peroxide was detected in the reaction solution. Also, no polymer was formed. Methyl methacrylate was distilled off in the same manner as in Example 1,
As a result, 260 g of a pale yellow transparent liquid was obtained (no peroxide was detected, no polymer was detected). The results of this gas chromatography analysis showed that the methacrylic acid ester of propylene glycol monodicyclopentenyl ether was 98.7
It was in%.

Example 3 A device similar to that of Example 1 was used, except that bicyclo [2,2,1] hept-
2-en-5-ol 165 g [ 1.5 mol, peroxide content 18 ppm (converted to H ₂ O ₂ )] was added, 0.3 g of lithium hydride was added thereto, and the mixture was gently stirred at 50 ° C. for 1 hour. At this time, no peroxide was detected in the alcohol. Methyl methacrylate 45
0 g (4.5 mol) and hydroxynone monomethyl ether
0.2 g was charged and the reaction was carried out in the same manner as in Example 1. In addition, lithium hydride was not added on the way. No peroxide was detected after the reaction was completed. Further, no polymer was formed. Methyl methacrylate was distilled off in the same manner as in Example 1 and was passed to give a pale yellow transparent liquid.
258 g was obtained (no peroxide was detected, no polymer was detected). From the results of the gas chromatography analysis, the bicyclo (2.
2.1] The purity of methacrylic acid ester of hept-2-en-5-ol was 98.8%.

Example 4 In a device similar to that of Example 1, 194 g of ethylene glycol monodicyclopentenyl ether [ 1 mol were charged peroxide content 35 ppm (H ₂ O ₂ equivalent)] was charged 30 ° C. This lithium hydroxide (anhydrous) 0.4 g
The mixture was stirred for 2 hours. At this time, no peroxide was detected in the alcohol. Methyl methacrylate 35
Example 1 was charged with 0 g (3.5 mol) phenothiazine 0.08 g.
The reaction was performed in the same manner as in. 0.4 g of lithium hydroxide was added 1 hour after the reaction. No peroxide was detected in the reaction solution. Also, no polymer was formed. Methyl methacrylate was distilled off in the same manner as in Example 1 to obtain 255 g of a pale yellow transparent liquid (no peroxide was detected, no polymer was detected). From the results of gas chromatography analysis, the purity of methacrylic acid ester of ethylene glycol monodicyclopentenyl ether was 98.8%.

Example 5 In an apparatus similar to that of Example 1, 152 g of tricyclo [5.2.1.0 ^2,6 ] decan-8-ol [ 1 mol and a peroxide content of 15 ppm (converted to H ₂ O ₂ ) were charged, 1.0 g of potassium hydroxide was added thereto, and the mixture was stirred at 40 ° C. for 30 minutes. To this was charged 350 g (3.5 mol) of methyl methacrylate and 0.02 g of hydroquinone monomethyl ether, and the reaction was carried out in the same manner as in Example 1. 0.5 g of lithium hydroxide was added 30 minutes after the start of the reaction. No peroxide was detected in the reaction completed liquid. Further, no polymer was formed. Methyl methacrylate was distilled off in the same manner as in Example 1 to obtain 212 g of a pale yellow transparent liquid (no peroxide was detected, no polymer was detected). From the results of gas chromatography analysis, the purity of the methacrylic acid ester of tricyclo [5.2.1.0 ^2,6 ] decan-8-ol was 98.5%.

Example 6 In a device similar to that of Example 1, 194 g of ethylene glycol monodicyclopentenyl ether [ 1 mol, a peroxide content of 35 ppm (converted to H ₂ O ₂ )] was charged, 0.5 g of a 28% sodium methoxide-methanol solution was charged, and the mixture was stirred at 25 ° C. for 20 minutes (no detection of peroxide). 350g of methyl methacrylate (3.5mol)
And 0.08 g of phenothiazine were charged, and the reaction was carried out in the same manner as in Example 1. At 30 minutes, 1 hour and 2 hours of reaction,
28% sodium methoxide-methanol solution
Added 0.2g each. No peroxide was detected in the reaction completed liquid. Also, no polymer was formed. This reaction solution was washed twice with 100 g of 10% saline solution, and then methyl methacrylate was distilled off and passed over to obtain a pale yellow transparent liquid.
253 g was obtained (no peroxide was detected, no polymer was detected). From the results of gas chromatography analysis, the purity of methacrylic acid ester of ethylene glycol monodicyclopentenyl ether was 98.7%.

Comparative Example 1 In a device similar to that of Example 1, 150 g of tricyclo [5.2.1.0 ^2,6 ] dec-3-en-8 or 9-ol [ 1 mol, peroxide content 48 ppm (H ₂ O ₂ equivalent)], titanium tetraisopropoxide 3.0 g, hydroquinone monomethyl ether 0.11 g and methyl methacrylate 350 g (3.5 mol) were charged, and air was introduced at a rate of 50 ml / min. While reacting. After 10 minutes from the start of the reaction, formation of a polymer was observed (a small amount of the reaction solution was sampled, titanium tetraisopropoxide was removed, and a methanol solubility test was conducted. As a result, the polymer was precipitated and became cloudy). The peroxide in the reaction solution at this time was about 300 ppm (converted to H ₂ O ₂ ). When the reaction was continued as it was, 1 hour later, a remarkable formation of a polymer was observed, and the reaction solution thickened and the stirring became impossible.

Comparative Example 2 In the same apparatus as in Example 1, 194 g of ethylene glycol monodicyclopentenyl ether [ 1 mol, peroxide content 35 ppm (H ₂ O ₂ conversion)], methyl methacrylate 350 g (3.5 mol) and phenothiazine
0.08 g was charged and the temperature was raised while introducing air at a rate of 50 ml / min. After 15 minutes, when the liquid temperature reached 100 ° C, 0.4 g of lithium hydroxide was added and the reaction was carried out. 0.4 g of lithium hydroxide was added 1 hour after the reaction. Formation of a polymer was observed at the start of the reaction. It was observed that the reaction solution became turbid due to the polymer 30 minutes after the start of the reaction. However, the reaction was continued for 4 hours without becoming impossible to stir due to the increase in viscosity. Methyl methacrylate was distilled off from this reaction-completed liquid in the same manner as in Example 1. The obtained liquid was colored in red and could not be used as a product as it was. When mixed with methanol in a ratio of 1: 1, a white precipitate of the polymer was formed. HL
It was found from C analysis that the polymer content was about 4%.

Comparative Example 3 Ethylene glycol monodicyclopentenyl ether dried in the same apparatus as in Example 1 with a 20% aqueous sodium hydroxide solution to decompose peroxide and then dried with Glauber's salt.
194g ( 1 mol, peroxide not detected), methyl methacrylate
350 g, phenothiazine 0.08 g and titanium tetraisopropoxide 3.0 g were charged and reacted in the same manner as in Example 1. Formation of a polymer was observed 20 minutes after the start of the reaction. The peroxide in the reaction solution at this time was about 250 ppm (converted to H ₂ O ₂ ). When heating was continued as it was, remarkable formation of a polymer was observed after 30 minutes, and the reaction solution thickened and stirring became impossible.

COMPARATIVE EXAMPLE 4 Tricyclo [5.2.1.0 ^2,6 ] decan-8-ol 152 g [in the same device as in Example 1] 1 mol, peroxide content 15 ppm (H ₂ O ₂ conversion)], methyl methacrylate 350 g (3.5 mol), hydroquinone monomethyl ether 0.02 g and titanium tetraisopropoxide 3.0 g were charged, and the reaction was carried out in the same manner as in Example 1. Natsuta. Formation of a polymer was observed after a reaction time of 1.5 hours. At this time, the peroxide in the reaction solution was about 300 ppm (converted to H ₂ O ₂ ). When heating was further continued, it was observed that a polymer was remarkably generated after 1 hour, and the reaction solution remarkably thickened.

Comparative Example 5 In the same device as in Example 1, 194 g of ethylene glycol monodicyclopentenyl ether [ 1 mol, peroxide content 35 ppm (H ₂ O ₂ equivalent)] and paratoluene sulfonic acid 5 g were charged and heated to 60 ° C. with stirring and kept at the same temperature for 10 minutes, then methyl methacrylate
350 g, 4-methoxyphenol 0.13 g was charged, and the same reaction as in Example 1 was performed thereafter. After 1 hour from the reaction, the reaction solution was colored blackish brown, and when the reaction solution was placed in an 18φ test tube, it could not be seen through on the other side. At this time, the reaction rate is 25%, and further, an oligomer by-product having a molecular weight of about 700 to 1000 (presumed to be a polymer by ionic polymerization of dicyclopentadiene)
Was generated by about 2%.

(Effect of the Invention) According to the present invention, a methacrylic acid ester of an alicyclic alcohol with little coloration can be produced by efficiently suppressing side reactions.

Claims (8)

[Claims] 1. A process for producing a methacrylic acid ester of an alicyclic alcohol, which comprises treating an alicyclic alcohol with an alkaline substance and then performing a transesterification reaction with methyl methacrylate in the presence of the alkaline substance. 2. A process for producing a methacrylic acid ester of an alicyclic alcohol according to claim 1, which comprises treating the alicyclic alcohol with an alkaline substance and further adding methyl methacrylate to carry out a transesterification reaction. Law. 3. A methacrylic acid ester of an alicyclic alcohol according to claim 1 or 2, wherein the alicyclic alcohol is an alicyclic alcohol having an alicyclic group having a tertiary carbon in the ring. Manufacturing method. 4. A methacrylic acid ester of an alicyclic alcohol according to claim 1 or 2, wherein the alicyclic alcohol is an alicyclic alcohol having an alicyclic group having two kinds of bonds in the ring. Manufacturing method. 5. The alicyclic alcohol according to claim 1 or 2, wherein the alicyclic alcohol is an alicyclic alcohol having an alicyclic group having a tertiary carbon and a double bond in the ring. Method for producing methacrylic acid ester. 6. The method according to claim 1, wherein the alkaline substance is at least one compound selected from the group consisting of sodium, potassium, lithium and basic compounds thereof.
Item 4. A method for producing a methacrylic acid ester of an alicyclic alcohol according to Item 4 or 5. 7. The method for producing a methacrylic acid ester of an alicyclic alcohol according to claim 1, wherein the transesterification reaction is carried out in the presence of a polymerization inhibitor. 8. The method for producing a methacrylic acid ester of an alicyclic alcohol according to claim 1 or 7, wherein the transesterification reaction is carried out while blowing molecular oxygen.