JP4609642B2 - Method for producing cycloalkyl alkyl ether - Google Patents

Description

  The present invention relates to a method for producing a cycloalkyl alkyl ether useful as a cleaning solvent, a reaction solvent, an extraction solvent, a solvent for electronic / electric materials, a release agent, and the like for electronic parts and precision machine parts.

  Conventional methods for producing ethers by addition reaction of olefin and alcohol include, for example, (a) a method using crystalline aluminosilicate as a catalyst (Patent Document 1), and (a) a special alumino having a large number of acid points on the outer surface. A method using a silicate (Patent Document 2), and (c) a method using a tungsten oxide in which water of crystallization of a heteropolyacid is adjusted to an average of 3.0 molecules or less per molecule of the heteropolyacid as a catalyst (Patent Document 3) ), (D) a method using a cation exchange resin dried as a catalyst until the water content is 5% by weight or less (Patent Document 4) is known.

  However, when a solid acid other than a cation exchange resin is used in these production methods (Patent Documents 1 to 3), the conditions for the addition reaction are severe, resulting in low productivity and large equipment. There was a problem. When a cation exchange resin dried as a solid acid catalyst is used and a cycloalkyl alkyl ether is produced on an industrial scale using an alicyclic olefin as a starting material (Patent Document 4), the solid acid catalyst is dried and filled. In some cases, static electricity is generated when the catalyst is charged, or a decrease in catalyst activity becomes a problem.

JP 59-25345 A Japanese Patent Laid-Open No. 61-249945 JP-A-5-163188 WO03 / 002500 publication

  The object of the present invention is to use a cation exchange resin as a solid acid catalyst, and to produce a cycloalkyl alkyl ether on an industrial scale using an alicyclic olefin as a starting material, without generating static electricity when filling the catalyst, An object of the present invention is to provide a method capable of preventing a decrease in catalyst activity.

  As a result of intensive studies to solve the above problems, the present inventors have found that (I) the heat-resistant temperature of the cation exchange resin as the catalyst is low (heat-resistant temperature is about 80 to 190 ° C.), and ( II) When producing cycloalkyl alkyl ethers on an industrial scale, the removal of heat of reaction is not in time, and the cation exchange resin deteriorates due to the heat generated at the beginning of the reaction (generation of hot spots, etc.). Thus, the inventors have found that if a specific pretreatment process is performed, sufficient catalytic activity can be obtained without drying and filling the solid acid catalyst, and the present invention has been completed.

That is, the present invention
(1) In a method for producing a cycloalkyl alkyl ether by using a fixed bed flow type reactor and subjecting an alicyclic olefin and alcohol (1) to an addition reaction in the presence of a cation exchange resin, before the addition reaction, (A) filling the reactor with the cation exchange resin in a wet state with water to form a catalyst layer;
(B) supplying alcohol (2) to the catalyst layer to replace and remove water;
(C) supplying an inert gas to the catalyst layer after step (b) to replace and remove alcohol (2);
A process for producing a cycloalkyl alkyl ether, characterized in that the pretreatment step comprising: (a) to (c) in the order of
(2) The production method as described above, wherein the alicyclic olefin and the alcohol (1) are subjected to an addition reaction at a temperature higher by 5 ° C. or more than the temperature of the pretreatment step,
(3) The production method according to the above, wherein the alicyclic olefin is cyclopentene and the alcohol (1) is methanol,
Is to provide.

  The method for producing a cycloalkyl alkyl ether of the present invention does not generate static electricity when the catalyst is charged, and does not cause a decrease in the catalytic activity during the reaction even in an industrial scale reaction apparatus. Cycloalkylalkyl ethers can be produced with selectivity.

The method for producing a cycloalkyl alkyl ether according to the present invention comprises the use of a fixed bed flow reactor to produce a cycloalkyl alkyl ether by an addition reaction between an alicyclic olefin and an alcohol (1) in the presence of a cation exchange resin. In this method, before the addition reaction, (a) a step of filling the reactor with the cation exchange resin in a wet state with water to form a catalyst layer (hereinafter abbreviated as “step (a)”). ,
(B) supplying alcohol (2) to the catalyst layer to replace and remove water (hereinafter abbreviated as “step (b)”);
(C) a step (hereinafter abbreviated as “step (c)”) in which an inert gas is supplied to the catalyst layer after step (b) to replace and remove alcohol (2);
The preprocessing consisting of is performed in the order of (a) to (c).

[1. Reaction raw materials]
The alicyclic olefin used in the present invention has an aliphatic monocyclic or polycyclic skeleton, and has at least one carbon-carbon double bond in these ring skeletons.
Each of the ring skeletons is preferably composed of 3 to 10 carbons and has a substituent such as an alkyl group, aryl group, halogen atom, nitro group, amino group, alkoxy group, sulfone group, and cyano group. Also good.

  The alicyclic olefin is preferably an alicyclic olefin having a monocyclic ring having 5 to 8 carbon atoms constituting the ring skeleton, from the viewpoint of availability and the ability to obtain the target product more efficiently, and has a substituent. Cyclopentene which may be substituted or cyclohexene which may have a substituent is particularly preferred.

  Specific examples of the cyclopentene which may have a substituent include cyclopentene, 1-methylcyclopentene, 3-methylcyclopentene, 1,3-dimethylcyclopentene, 1-fluorocyclopentene and 1-phenylcyclopentene. Examples of the cyclohexene which may have a substituent include cyclohexene, 1-methylcyclohexene, 4-methylcyclohexene, 1,3-dimethylcyclohexene, 1-fluorocyclohexene, 4-chlorocyclohexene, 1-phenylcyclohexene, and 4- And phenylcyclohexene. Among these, cyclopentene or cyclohexene is preferable, and cyclopentene is particularly preferable.

  The alcohol (1) used as a reaction raw material of the present invention is not particularly limited as long as it can undergo an addition reaction with an alicyclic olefin in the presence of a cation exchange resin, but a cycloalkyl alkyl ether can be efficiently obtained. For these reasons, linear and branched saturated alcohols having 1 to 10 carbon atoms or cycloalkyl alcohols having 3 to 8 carbon atoms are preferable, and linear and branched saturated alcohols having 1 to 6 carbon atoms are particularly preferable. .

  Examples of linear and branched saturated alcohols having 1 to 10 carbon atoms include, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, n-pentyl alcohol, and n-hexyl alcohol. Etc. Examples of the cycloalkyl alcohol having 3 to 8 carbon atoms include cyclopropyl alcohol, cyclopentyl alcohol, and cyclohexyl alcohol. Among these, linear and branched saturated alcohols having 1 to 3 carbon atoms are more preferable, and methyl alcohol is particularly preferable.

The amount of alcohol (1) used is usually 0.002 to 11 mol, preferably 0.1 to 5 mol, particularly preferably 0.2 to 1 mol, per 1 mol of alicyclic olefin.
By making it in the above range, the effect of the present invention becomes more remarkable.

  In the present invention, alicyclic olefin and alcohol (1) are used as reaction raw materials. The water content in the reaction raw materials is preferably 10,000 ppm by weight or less, more preferably 1,000 ppm by weight or less, and particularly preferably. Is 500 ppm by weight or less. If the amount of water is too large, the reaction yield may decrease. In addition, it is preferable from a viewpoint of the reaction yield to supply the reaction raw material to the fixed bed flow-type reactor in the vaporized state.

  In practicing the present invention, a solvent or diluent inert to the cation exchange resin, alicyclic olefin and alcohol (1) can be added to the reaction system. The solvent or diluent may be used alone or in combination of two or more.

  Solvents and diluents that can be used include, for example, aliphatic saturated hydrocarbons such as n-butane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane; Aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, anisole, cumene and nitrobenzene; cyclopentane, alkyl-substituted cyclopentanes, alkoxy-substituted cyclopentanes, nitro-substituted cyclopentanes, cyclohexane, alkyl-substituted cyclohexanes, alkoxy Substituted cyclohexanes, nitro substituted cyclohexanes, cycloheptane, alkyl substituted cycloheptanes, alkoxy substituted cycloheptanes, nitro substituted cycloheptanes, cyclooctane, alkyl substituted cyclooctanes, alkoxy substituted cyclohexane Tan acids, alicyclic saturated hydrocarbons and nitro-substituted octanes; nitrogen, argon, and the like air and helium. The amount of the solvent and diluent used is not particularly limited, and any amount can be selected as long as the addition reaction is not inhibited, but preferably 100 parts by weight or less with respect to 100 parts by weight of the total amount of the alicyclic olefin and the alcohol, The amount is more preferably 50 parts by weight or less, particularly preferably 10 parts by weight or less.

[2. Catalyst]
The cation exchange resin used as a catalyst is made of an insoluble and porous synthetic resin having a polar group capable of exchanging cations on a polymer substrate having a fine three-dimensional network structure.

  Cation exchange resins can be broadly classified into gel resins and porous resins as classified from the geometric structure of cation exchange resins. In the present invention, both gel resins and porous resins are used. Can be used. The cation exchange resin type includes a proton acid type in which the proton part of the ion exchange group is a proton as it is and an alkali metal salt type in which the proton of the ion exchange resin is exchanged for an alkali metal ion. Cation exchange resins are preferred.

  As the cation exchange resin, as a polymer substrate having a sulfonic acid group or a carboxylic acid group as an ion exchange group and bonded with an ion exchange group, a polymer substrate obtained by condensation polymerization of phenol and formaldehyde, styrene or Examples thereof include those having a copolymer substrate of halogenated styrene and divinylbenzene. Among these, from the viewpoint of availability and easy handling, it is preferable to use a sulfonic acid type strongly acidic cation exchange resin having a sulfonic acid group as an ion exchange group, and a copolymer of styrene or halogenated styrene and divinylbenzene. It is particularly preferable to use a sulfonic acid type styrene-based strong acidic cation exchange resin having a polymer base and a sulfonic acid group as an ion exchange group.

  Preferable specific examples of the cation exchange resin include a styrene strong acid cation exchange resin gel type manufactured by Mitsubishi Chemical Corporation, product names DIAION SK1B, SK012, SK104, SK106, SK110, SK112 and SK116; Cation exchange resin porous type, product names PK208, PK212, PK216, PK220 and PK228; Styrenic strongly acidic cation exchange resin high porous type, product names HPK25, Diaion RCP-160M, RCP-160H and RCP-170H; Styrene-based strongly acidic cation exchange resin, product name RCP145; strong acid Bayer catalyst gel type manufactured by Bayer, product names K1221, K1431, K1481, and K1491; strong acid Bayer catalyst macroporous type, product name K2 431, K2621 and K2641; Amberlite (product name XE-284) manufactured by Rohm and Haas; Amberlist manufactured by Organo Corporation; product names CSP-2 and A-15; Among them, the product name DIAION RCP-160M having a high specific surface area is preferable.

  The apparent density of these cation exchange resins (the weight (g) of the cation exchange resin when the cation exchange resin is filled in a container having a volume of 1 liter) is usually 500 to 1,000, preferably 600 to 900. The average particle size of the cation exchange resin is not particularly limited, but is usually 0.02 mm to 10 mm, preferably 0.3 mm to 2 mm. The cation exchange resin is preferably used in a protonic acid form, and can be used repeatedly by performing a normal regeneration treatment.

[3. Reactor]
The addition reaction is carried out by using a fixed bed flow type reactor, filling the reactor with a cation exchange resin to form a catalyst layer, and circulating the alicyclic olefin and alcohol through the catalyst layer. Here, the “catalyst layer” refers to a packed bed of cation exchange resin formed in a fixed bed flow type reactor, and the gap between the cation exchange resins may be a space, alcohol, etc. It may be filled with liquid or gas.
In the present invention, the “fixed-bed flow reactor” refers to a reactor having any structure that has a catalyst layer inside the reactor and that allows the alicyclic olefin and alcohol to flow through the catalyst layer. . The structure of the reactor is not particularly limited, but a tubular reactor is preferable. As the tubular reactor, a single-tube reactor having a heating device or a multi-tube heat exchange reactor may be used, but a multi-tube heat exchange reactor having good heat removal efficiency of reaction heat is preferable.

  When a tubular reactor (hereinafter abbreviated as “tubular reactor”) is used, the inner diameter of the tubular reactor can be arbitrarily set in consideration of the catalyst particle diameter, but is preferably 5 to 1000 mm, more preferably. Is 10 to 200 mm. If the inner diameter of the tubular reactor is too large, it is difficult to remove the heat of addition reaction. Conversely, if the inner diameter of the tubular reactor is too small, the number of required tubular reactors increases remarkably and the equipment becomes complicated and installed. It is disadvantageous in terms of space.

[4. Pretreatment steps (a) to (c)]
In the present invention, (a) the cation exchange resin is used as a pretreatment for addition reaction of the alicyclic olefin and the alcohol (1) in the presence of the cation exchange resin using a fixed bed flow reactor. Filling the reactor in a wet state with water to form a catalyst layer;
(B) supplying alcohol (2) to the catalyst layer to replace and remove water;
(C) supplying an inert gas to the catalyst layer to replace and remove the alcohol (2);
Is essential.

(Process (a))
In the step (a), a cation exchange resin is filled in a fixed bed flow reactor in a wet state with water to form a catalyst layer.
Water for wetting the cation exchange resin is not particularly limited as long as it does not adversely affect the cation exchange resin and has no reactivity with the reactor material, but the metal cation of the proton in the cation exchange resin In order to prevent ion exchange due to cation exchange water or distilled water is preferably used. If the proton of the cation exchange resin as a catalyst is ion-exchanged with a metal cation, the catalytic activity may be reduced.
The method of wetting the cation exchange resin is not particularly limited, but a cation exchange resin marketed in a wet state may be used as it is, or a commercially available cation exchange resin may be dispersed in water and moistened.

In addition, as for the cation exchange resin, a commercially available product may be charged as it is into a fixed bed flow reactor, or after pretreatment with an acid, it may be charged into a fixed bed flow reactor. From the viewpoint of activity, it is preferable to charge the fixed bed flow reactor after pretreatment with acid.
As a pretreatment method with an acid, for example, a method in which a cation exchange resin is added to dilute acid such as dilute hydrochloric acid or dilute sulfuric acid and left at 20 to 100 ° C. for several minutes to several tens of hours or stirred, And a method in which a dilute acid is allowed to flow until the liquid from which the cation exchange resin is eluted from one side of the column becomes acidic. Further, the column may be a fixed bed flow reactor itself, in which case the diluted acid may be passed through the fixed bed flow reactor before the step (b). It is preferable to use the ion exchange resin pretreated with an acid after thoroughly washing with distilled water or deionized water to remove excess acid.
In the present invention, “wet state with water” means that water adheres to the cation exchange resin (including water present in the pores of the cation exchange resin), and the adhering water. The ratio of the amount of the cation exchange resin and water to the total amount (hereinafter referred to as “water content”) is 30% by weight or more. The water content of the cation exchange resin is preferably 40% by weight or more, particularly preferably 50% by weight or more.

(Process (b))
In the step (b), the alcohol (2) is supplied to the catalyst layer formed in the step (a), and the adhering water is replaced and removed by the alcohol (2).
The alcohol (2) for replacing and removing the water of the cation exchange resin charged in the fixed bed flow reactor is not particularly limited as long as it does not adversely affect the cation exchange resin and does not cause a significant reaction with water. The thing similar to what was illustrated as alcohol (1) used as an addition reaction raw material is used. Among them, the temperature control in the next step (depending on the type of alcohol used, a hot spot may occur in the catalyst layer, which may exceed the heat-resistant temperature of the cation exchange resin) and have an appropriate boiling point. To C1-C10 linear or branched saturated alcohol or C3-C8 cycloalkyl alcohol, more preferably C1-C6 linear or branched saturated alcohol, and methyl alcohol. Is particularly preferred.
In addition, if the same alcohol (1) used as the addition reaction raw material is used as the alcohol (2), the types of impurities contained in the reaction mixture at the outlet of the fixed bed flow reactor are reduced. There is a merit that becomes easy.

  The alcohol (2) used in the step (b) may be in a liquid or gas state, but it is preferable to use it in a liquid from the viewpoint of the efficiency of replacing and removing water.

The temperature of the step (b) is not particularly limited as long as it does not exceed the heat resistant temperature of the cation exchange resin, but is preferably 1 to 180 ° C, more preferably 5 to 100 ° C, and particularly preferably 10 to 50 ° C. It is a range.
By making it into the above range, the effect of the present invention is further improved.

  Although the pressure at the time of water removal is not particularly limited, the absolute pressure is preferably 1 to 5,000 kPa, more preferably 50 to 500 kPa, and particularly preferably 50 to 200 kPa.

  The amount of the alcohol (2) used in the step (b) is not particularly limited, but is preferably 1 to 100 times, more preferably 2 to 20 times, and more preferably 3 to 10 times the volume of the catalyst layer (based on the empty column). Is particularly preferred. If the amount of alcohol is too small, water cannot be replaced sufficiently, resulting in a decrease in the addition reaction yield. If the amount of alcohol is too large, the amount of waste increases. The “empty standard” means that the volume occupied by the entire catalyst layer including the gap between the cation exchange resins is used as a standard.

  The degree of displacement removal of the catalyst layer can be detected by measuring the amount of water in the alcohol discharged from the outlet of the fixed bed flow reactor. Substitution removal is preferred until the amount of water in the discharged alcohol is 5% by weight or less, substitution is more preferred until it is 1% by weight or less, and substitution removal is carried out until it is 0.5% by weight or less. It is particularly preferred.

  The water removal can be carried out either intermittently or continuously, but is preferably carried out continuously from the viewpoint of operation efficiency.

(Process (c))
In step (c), an inert gas is supplied to the catalyst layer from which water has been removed with alcohol in step (b) to remove alcohol.
Examples of the inert gas include nitrogen gas, helium gas, argon gas, and air. Nitrogen gas is preferable.
The temperature at which the alcohol in the catalyst layer is removed by replacement with an inert gas is not particularly limited as long as it does not exceed the heat resistance temperature of the cation exchange resin as the catalyst, but is preferably 1 to 180 ° C., more preferably 5 It is -100 degreeC, Most preferably, it is the range of 10-50 degreeC.
By making it into the above range, the effect of the present invention is further improved.

  Although the pressure of a process (c) is not specifically limited, Preferably it is 0-5000 kPa by absolute pressure, More preferably, it is 0-2000 kPa, Most preferably, it is the range of 50-500 kPa.

  The amount of the inert gas when the alcohol in the catalyst layer is replaced with an inert gas is preferably 0.1 to 100 times the volume of the catalyst layer volume (empty standard), and is 0.1 to 10 times the volume. More preferably, 0.3-5 volume times is further more preferable, and 0.5-3 volume times is especially preferable. If the amount of the inert gas is too small, excess alcohol remains in the catalyst layer, and the pressure loss at the start of the addition reaction increases. On the other hand, if the amount of the inert gas is too large, the catalyst layer is dried more than necessary, and the heat generated at the start of the addition reaction is increased, which may deteriorate the catalyst.

[5. Addition reaction]
In the present invention, after the pretreatments of the above steps (a) to (c), the addition reaction is started by supplying the alicyclic olefin and alcohol to the fixed bed flow reactor.

The addition reaction temperature can be arbitrarily set within a range not lower than the boiling point of the alicyclic olefin and alcohol and not higher than the heat resistance temperature of the cation exchange resin as a catalyst, preferably 60 to 180 ° C., more preferably 70. ~ 150 ° C. When the addition reaction temperature is too low, the addition reaction rate decreases. When the addition reaction temperature is too high, the cation exchange resin as a catalyst is deteriorated by heat, and the catalytic activity may be reduced.
In addition, when an addition reaction is performed by heating a fixed bed flow reactor with a heat medium, the heat medium temperature at the start of the reaction is maintained at 50 to 75 ° C. for 0.1 hour or more and then increased to 80 to 100 ° C. Since the rapid temperature rise at the beginning of the reaction can be prevented, the effect of the present invention becomes even more remarkable.

In addition, after performing the said pretreatment process, it is preferable from a viewpoint of prevention of a fall of catalyst activity to carry out addition reaction of an alicyclic olefin and alcohol at the temperature higher 10 degreeC or more than the temperature of this pretreatment process. The internal temperature of the catalyst layer in the addition reaction of the alicyclic olefin and alcohol is more preferably 20 ° C. or more, and particularly preferably 30 ° C. or more, higher than the temperature during the pretreatment step. The “temperature during the pretreatment step” refers to the highest temperature reached in the steps (a) to (c).
Moreover, the effect of this invention becomes still more remarkable by heating up to addition reaction temperature, supplying an alicyclic olefin and alcohol after completion | finish of a pre-processing process.

  The addition reaction pressure is not particularly limited as long as the alicyclic olefin and alcohol are in a gaseous state, but is preferably 0.01 to 10000 kPa in absolute pressure, more preferably 1 to 5000 kPa, and particularly preferably 50 to 200 kPa. . If the pressure is too low, the production efficiency decreases, and if the pressure is too high, side reactions (such as dehydration condensation of alcohols) are promoted.

  The target cycloalkyl alkyl ether can be isolated and purified by subjecting the reaction liquid obtained from the outlet of the fixed bed flow reactor to usual separation and purification methods such as solvent extraction and distillation. Although distillation can be carried out by either a batch method or a continuous method, the continuous method is preferred from the viewpoint of operational efficiency.

（式中、Ｒ^１は置換基を有していてもよいシクロペンチル基又は置換基を有していてもよいシクロヘキシル基を表し、Ｒ^２は炭素数１〜１０のアルキル基又は炭素数３〜８のシクロアルキル基を表す。） As the cycloalkyl alkyl ether obtained by the production method of the present invention, a cycloalkyl alkyl ether represented by the following formula (1) is preferable.

(In the formula, R ¹ represents a cyclopentyl group which may have a substituent or a cyclohexyl group which may have a substituent, and R ² represents an alkyl group having 1 to 10 carbon atoms or 3 to 8 carbon atoms. Represents a cycloalkyl group of

Preferable specific examples of the cycloalkyl alkyl ether represented by the formula (1) include cyclopentyl methyl ether, cyclopentyl ethyl ether, cyclopentyl n-propyl ether, cyclopentyl isopropyl ether, cyclopentyl n-butyl ether, cyclopentyl sec-butyl ether, cyclopentyl tert. Cyclopentyl alkyl ethers such as butyl ether, cyclopentyl n-pentyl ether, dicyclopentyl ether, cyclopentyl cyclohexyl ether; cyclohexyl methyl ether, cyclohexyl ethyl ether, cyclohexyl n-propyl ether, cyclohexyl isopropyl ether, cyclohexyl n-butyl ether, cyclohexyl sec-butyl ether , Rohekishiru tert- butyl ether, cyclohexyl n- pentyl ether, cyclohexyl cyclopropyl ether, cyclohexyl alkyl ethers such as dicyclohexyl ether, and the like. Among these, cyclopentyl alkyl ether in which R ¹ is a cyclopentyl group is more preferable, cyclopentyl methyl ether or cyclopentyl ethyl ether is more preferable, and cyclopentyl methyl ether is particularly preferable.

  The cycloalkyl alkyl ether obtained by the production method of the present invention is used as a cleaning solvent for electronic parts, precision machine parts, a reaction solvent for various chemical reactions, an extraction solvent, a crystallization solvent, a solvent for electronic / electrical materials, and a release agent. Useful.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the scope of the present invention is not limited by these examples. Note that “parts” represents “parts by weight” unless otherwise specified. )

(1) Analysis by gas chromatography (hereinafter referred to as “GC analysis”) was performed under the following conditions.
Analytical instrument: Product name Agilent 6850 (manufactured by Agilent)
Column: Capillary column Product name HP-5 30 m × 0.25 mmφ (manufactured by Hewlett-Packard Japan)
Column temperature: 40 ° C. (10 minutes), 40 ° C. → 250 ° C. (10 ° C./min)
Inlet temperature: 200 ° C
Detector temperature: 300 ° C
Carrier gas: He
Detector: FID
(2) Cyclopentene conversion rate (hereinafter abbreviated as “CPE conversion rate”) (%) is (cyclopentene weight in 1 g of raw material liquid−cyclopentene weight in 1 g of reaction liquid) / (cyclopentene weight in 1 g of raw material liquid). Calculated with x100.
(3) Cyclopentyl methyl ether selectivity (hereinafter abbreviated as “CPME selectivity”) (%) is (number of moles of cyclopentyl methyl ether in 1 g of reaction liquid) / (number of moles of cyclopentene in 1 g of raw material liquid−reaction liquid). The number of moles of cyclopentene in 1 g) × 100.
(4) The moisture content is measured by the Karl Fischer coulometric titration method using a moisture measuring device (product name AQ-7, generating solution: product name Aqualite (RS-A), counter electrode solution: product name Aqualite (CN), Hiranuma. Sangyo Co., Ltd.).

[Example 1]
1. Pretreatment step (a) (formation of catalyst layer)
A commercially available styrene-based cation exchange resin (manufactured by Mitsubishi Chemical Corporation, product name DIAION RCP-160M, heat-resistant temperature: 120 ° C., water content: 53% by weight) is dispersed in distilled water and sufficiently swelled. The exchanged resin was measured with a graduated cylinder, and a fixed bed flow reactor (tubular, inner diameter 57 mm, made of SUS316) equipped with a thermocouple and heat medium circulation jacket in the axial direction had an empty catalyst layer volume of 1275 ml. It was filled to become. Thereafter, a raw material supply pump, a raw material vaporizer, a reactor outlet gas condenser, and a reaction liquid collection tank were connected to the reactor.

2. Pretreatment step (b) (substitution removal of water in catalyst layer with alcohol (2))
Methanol was introduced into the fixed bed flow reactor after completion of the pretreatment step (a) at a flow rate of 34 ml / min for 2.5 hours under conditions of 25 ° C. and an absolute pressure of 101 kPa, and water in the catalyst layer was discharged. Replacement with methanol was removed.
When the methanol discharged from the outlet of the fixed bed flow reactor at the end of the flow was collected and the water content was measured, the water content was 0.25% by weight.

3. Pretreatment step (c) (replacement removal of alcohol (2) with inert gas)
Nitrogen gas was introduced into the fixed bed flow reactor after completion of the pretreatment step (b) at a supply rate of 1245 ml / min for 1 minute under the conditions of 25 ° C. and absolute pressure of 111 kPa, and methanol was replaced with nitrogen gas. Removal was performed.

4). Reaction Step After completion of the pretreatment step (c), the temperature of the heating medium in the reactor was raised to 70 ° C., and then a mixture of cyclopentene and methyl alcohol vaporized by the vaporizer (water content of 120 wt ppm in the mixture, mixing) Molar ratio: cyclopentene / methanol = 1.6 / 1) was supplied to the fixed bed flow reactor at a supply rate of 2.83 L / min (volume conversion in the standard state) to initiate the reaction. At this time, the maximum temperature in the fixed bed flow reactor was 103 ° C., the absolute pressure at the inlet of the fixed bed flow reactor was 133 kPa, and the absolute pressure at the outlet of the fixed bed flow reactor was 101 kPa. When the heat medium temperature of the fixed bed flow type reactor was increased to 90 ° C. at the stage where the exotherm at the beginning of the reaction was finished (0.5 hr after the start of the reaction), the maximum temperature in the fixed bed flow type reactor was 95 ° C. The fixed bed flow type reactor inlet pressure was 116 kPa, and the fixed bed flow type reactor outlet pressure was normal pressure. Furthermore, when the reaction liquid discharged | emitted from a fixed bed flow-type reactor outlet after 5 hours was extract | collected and GC analysis was performed, CPE conversion ratio was 14.4% and CPME selectivity was 93.7%. In the series of operations, the internal temperature of the fixed bed flow reactor was maintained at 70 to 103 ° C., which was 30 ° C. higher than the temperature in the pretreatment step. Further, the internal temperature of the fixed bed flow reactor did not exceed the heat resistance temperature (120 ° C.) of the catalyst, and no decrease in activity due to deterioration of the catalyst was observed.

[Comparative Example 1]
The same commercially available styrenic cation exchange resin as in Example 1 was placed in a vacuum dryer, dried at a pressure of 13.3 Pa and a temperature of 70 ° C. for 10 hours, then placed in a desiccator and dried at room temperature for 1 week, and then at 60 ° C. Dry nitrogen gas was circulated, dried for 4 hours, and then returned to room temperature to obtain a dry ion exchange resin (water content: 2.1% by weight).
Next, the same fixed bed flow reactor as in Example 1 was packed with the dry ion exchange resin obtained above so as to have the same catalyst layer volume as that of Example 1 on the basis of the empty column. Thereafter, a raw material supply pump, a raw material vaporizer, a reactor outlet gas condenser, and a reaction liquid collection tank were connected to the reactor.
After raising the temperature of the heat medium in the fixed bed flow type reactor to 70 ° C., a mixture of cyclopentene and methyl alcohol (mixing molar ratio: cyclopentene / methanol = 1.6 / 1) converted to a molecular form by a vaporizer was reduced to 2 The reaction was started by feeding to a fixed bed flow reactor at a feed rate of 0.83 L / min (converted to volume in standard state). At this time, the maximum temperature in the fixed bed flow reactor increased to 130 ° C. and exceeded the heat resistance temperature (120 ° C.) of the catalyst. When the heat medium temperature of the fixed bed flow reactor was raised to 90 ° C. at the stage where the heat generation at the beginning of the reaction was finished, the maximum temperature in the fixed bed flow reactor was 97 ° C. Furthermore, when the reaction liquid discharged | emitted from the fixed bed flow-type reactor outlet after 5 hours was extract | collected, GC analysis was performed and the reaction result was calculated, CPE conversion rate was 9.4% and CPME selectivity was 93.2. %Met.

  Example 1 in which an addition reaction was carried out by supplying cyclopentene and methanol after performing a specific pretreatment step, which is a feature of the present invention, was not performed at all, and was filled with a dried cation exchange resin. Compared with Comparative Example 1 in which the addition reaction was performed, the conversion rate on the basis of CPE was remarkably high, and no decrease in the catalyst activity was observed even when operated for a long time.

Claims (3)

In the method for producing a cycloalkyl alkyl ether by using an immobilized reaction catalyst in the presence of a cation exchange resin in the presence of a cation exchange resin to produce a cycloalkyl alkyl ether, (a ) Filling the reactor with the cation exchange resin in a wet state with water to form a catalyst layer;
(B) supplying alcohol (2) to the catalyst layer to replace and remove water;
(C) supplying an inert gas to the catalyst layer after step (b) to replace and remove alcohol (2);
A method for producing a cycloalkyl alkyl ether, wherein the pretreatment step comprising: (a) to (c) is carried out in this order.   The production method according to claim 1, wherein the alicyclic olefin and the alcohol (1) are subjected to an addition reaction at a temperature higher by 5 ° C or more than the temperature of the pretreatment step.   The production method according to claim 1, wherein the alicyclic olefin is cyclopentene and the alcohol (1) is methanol.