JP2001278913A - Method for producing epoxidized liquid polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxidation method which improves productivity without requiring a large amount of solvent, on epoxidizing an insoluble or little soluble liquid rubber based polymer in organic solvent. SOLUTION: The method of producing an epoxidized liquid polymer is characterized by epoxidizing a liquid polymer having a double bond, which is insoluble or little soluble in organic solvent, making the polymer suspended in a solvent beforehand or suspended in a solvent by using an epoxidation agent such as (1) an anhydrous organic solvent solution of a peracid, or (2) hydrogen peroxide and a catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a liquid epoxidized polymer used for paints, resin modifiers, rubber modifiers, adhesives and the like. More specifically, in converting a double bond in a molecular chain of a liquid polymer into an epoxy group using a peracid, anhydrous peracid, a peracid derived from hydrogen peroxide, or hydrogen peroxide and a catalyst The epoxidation is carried out by suspending the polymer in a solvent using the method described above to improve the productivity of the liquid epoxidized polymer.

[0002]

2. Description of the Related Art In general, the following methods are known as epoxidation methods. (1) An anhydrous organic solvent solution of a percarboxylic acid of a lower carboxylic acid such as formic acid or peracetic acid is prepared, and the anhydrous percarboxylic acid solution is added to the reaction system as an epoxidizing agent, and the solution is added in the presence or absence of a solvent. A method of performing an epoxidation reaction in the presence. (2) A percarboxylic acid is produced by previously reacting hydrogen peroxide with a lower carboxylic acid such as formic acid or acetic acid, and this percarboxylic acid is added to the reaction system as an epoxidizing agent, in the presence or absence of a solvent. Epoxidation reaction. (3) A method of epoxidation using hydrogen peroxide in the presence of a catalyst such as an osmium salt, tungstic acid and a solvent. Usually, when epoxidation is performed by these methods, the epoxidation is performed by dissolving the polymer to be epoxidized in a solvent. This is to obtain a high epoxidation rate by performing epoxidation in a uniform phase. In addition, percarboxylic acid is called peracid.

However, the polymer to be epoxidized is
When soluble in an organic solvent, the epoxidized product can be easily recovered by a desolvation operation, but when the polymer to be epoxidized is insoluble or has a low solubility in the organic solvent, When the solvent is removed, a liquid product is deposited, and the recovery method is extremely difficult. In particular, when the polymer to be epoxidized is a rubber-based polymer, the epoxidized product has viscosity and the workability is significantly deteriorated. In the case of a liquid polymer, the epoxy group can be cured by an acid or a cationic species by introducing an epoxy group. Therefore, epoxidized ones such as liquid polybutadiene and polyisoprene are used. Since these liquid polymers generally have good compatibility with solvents such as ester-based and aromatic-based solvents, there is no particular problem in recovering the product after epoxidation.

[0004] However, for example, among liquid polyisoprenes and the like, there is one having extremely low solubility in a solvent. In general, epoxidation is more efficient when dissolved in a solvent, and when epoxidizing a polymer with low solubility, it is necessary to use a large amount of a solvent. Often becomes.

In the prior art, for example, Japanese Unexamined Patent Publication No.
JP-A-11904 discloses a liquid polybutadiene 500.
A method is disclosed in which 1,300 parts of benzene is added to and dissolved in, and 700 parts of a 30% hydrogen peroxide solution is added and suspended, and epoxidation is performed by adding formic acid to the obtained suspension. I have. In this method, the efficiency of the transfer of the oxidizing agent between the large amount of benzene solvent system used for dissolving the liquid polybutadiene and the aqueous hydrogen peroxide system is poor, but the transfer is even worse because of the use of formic acid. The epoxidation rate by this method is 0.19 per structural unit of butadiene. Compared with the oxirane oxygen concentration of epoxidized polybutadiene which is currently commercially available, it is a very good epoxidation method. I can't say.

Japanese Patent Application Laid-Open No. Hei 9-165418 exemplifies epoxidation in a suspended state, which is epoxidation of a solid substance, and the recovery of the product is performed in the same manner as in a normal solid product. It can be performed by: In the case of the present invention in which a polymer that is liquid and has low solubility in a solvent is epoxidized, the product cannot be recovered by filtration, centrifugation, or the like, which is different from the technology described in JP-A-9-165418. .

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to use a liquid polymer having a double bond and an epoxidizing agent.
An object of the present invention is to provide a method for producing a liquid epoxidized polymer with high productivity.

[0008]

Under such circumstances, the present inventors have epoxidized a liquid polymer insoluble or low in solubility in an organic solvent or the like in a suspended state using a specific solvent. As a result, it has been found that productivity can be improved, and the present invention has been completed.

That is, a first aspect of the present invention is to prepare a liquid polymer having a double bond which is insoluble or has low solubility in an organic solvent by suspending it in a solvent in advance or by adding the following epoxidizing agent. Epoxidized by suspending in a solvent and using (1) a solution of a peracid in an anhydrous organic solvent, (2) hydrogen peroxide and a carboxylic acid, or (3) hydrogen peroxide and a catalyst as an epoxidizing agent. A method for producing a liquid epoxidized polymer is provided. A second aspect of the present invention provides the method for producing a liquid epoxidized polymer according to the first aspect of the present invention, wherein the peracid is derived from hydrogen peroxide. A third aspect of the present invention is the first aspect of the present invention, wherein the peracid is obtained by oxygen oxidation of an aldehyde.
A method for producing the liquid epoxidized polymer described above. A fourth aspect of the present invention is the production of the liquid epoxidized polymer according to any one of the first to third aspects of the present invention, wherein the polymer is a polymer having a unit composed of a diene monomer. Provide a way. A fifth aspect of the present invention is the method for producing a liquid epoxidized polymer according to the fourth aspect of the present invention, wherein the polymer is two or more blocks containing a diene-based monomer or a random copolymer. I will provide a. A sixth aspect of the present invention is the first aspect of the present invention, wherein the solvent that causes the suspension of the liquid polymer having a double bond is water, a carboxylic acid ester, a glycol ether, or a mixture thereof. 6. A method for producing a liquid epoxidized polymer according to any one of claims 1 to 5.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a liquid polymer, particularly a polymer having a portion composed of a diene monomer among liquid rubbers commercially available, is epoxidized in a suspension state to obtain a liquid epoxy. To produce a polymerized polymer.

Hereinafter, the present invention will be described in detail. In the present invention, as a liquid polymer to be subjected to epoxidation,
There is no particular limitation as long as it has a double bond in the molecule, but it may be a polymer of a single monomer or a polymer of two or more monomers. In the case of two or more polymers, a block copolymer or a random copolymer may be used. Examples of the polymer of a single diene monomer include polybutadiene, polyisoprene, and polybutylene. As a monomer that can constitute the copolymer, typical examples of a vinyl aromatic hydrocarbon compound include, for example, styrene, various alkylene-substituted styrenes such as α-methylstyrene, alkoxy-substituted styrene, vinylnaphthalene, and alkyl-substituted vinylnaphthalene. , Divinylbenzene, vinyltoluene and the like. It is also possible to use ethylene or propylene. One of these may be used alone, or two or more may be used in combination.

Representative examples of the diene compound that can constitute the block copolymer include, for example, 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-diene.
1,3-butadiene, piperylene, 3-butyl-1,3
-Octadiene, phenyl-1,3-butadiene and the like. Further examples include dicyclopentadiene, cyclopentadiene, and ethylidene norbornene having an alicyclic skeleton. One or a combination of two or more of these may be used. There is no limitation on the copolymer composition ratio (mass ratio) of the vinyl aromatic hydrocarbon compound and the conjugated diene compound that can constitute the block copolymer. The molecular weight of the polymer having a double bond in the molecule (hereinafter, also abbreviated to be epoxidized) is not particularly limited. It is desirable to be liquid at room temperature from the viewpoint of workability when handling raw materials and products. If it is liquid at normal temperature, there is no particular limitation on the terminal groups of these epoxidized substances. Examples of such a compound include Clayton Liquid L-1302 (a number available from Shell, number average molecular weight 8,000, iodine value 43) which is a liquid diene-based block copolymer, and LIR-290 (Kuraray) which is a liquid polyisoprene. Manufactured, number average molecular weight 25.0
00, iodine value 40) and the like.

In the present invention, a liquid polymer having a low solubility (that is, epoxidized in suspension) having a double bond is previously suspended in a solvent,
The organic solvent used for epoxidation is an organic solvent that is soluble in water at 0.5 to 10% by weight, preferably 1 to 6% by weight, more preferably 2 to 5% by weight. Compounds are preferred. Specifically, lower carboxylic acids having 1 to 5 carbon atoms such as methyl acetate, ethyl acetate, butyl acetate, methyl butyrate, and methyl isobutyrate have 1 to 1 carbon atoms.
Lower alcohol esters of 4; mono- or dimethyl ether of ethylene glycol or propylene glycol;
Lower alcohol ethers of mono- or diacetates of ethylene glycol or propylene glycol; lower alcohol esters of 1-4 carbon atoms of glycols having 2 to 4 carbon atoms; 2 to 4 carbon atoms such as methoxypropylene glycol acetate Lower alcohol ether having 1 to 4 carbon atoms of glycol of lower carboxylic acid esters of 1 to 4 carbon atoms; polyether esters such as mono or diacetate of diethylene glycol or dipropylene glycol; nitriles such as acetonitrile; chloroform and the like Halogenated hydrocarbons and the like. Among these, it is desirable to use ethyl acetate or the like because of the low solubility of the epoxidized substance and the ease of recovering the organic solvent thereafter.
Further, in the present invention, since a solvent that forms a suspension by adding an epoxidizing agent to a liquid polymer having a double bond contains a peracid, water, the lower carboxylic acid lower alcohol Examples include esters, glycol ethers, or mixtures thereof. Particularly, as the solvent used in the epoxidation reaction, if the produced liquid epoxidized substance is dissolved, it becomes difficult to recover the solvent. Therefore, it is desirable to use a solvent in which the solubility of the liquid epoxidized substance is as low as possible. Therefore, hexane, octane, cyclohexane, cycloheptane, benzene, toluene,
Xylene and naphthalene alone are not preferred because of their low solubility in water. However, it can be used if it is prepared as a mixed solvent so as to have the above-mentioned solubility in water. Further, solvents in which the solvent itself is oxidized by a peracid, such as ketones such as acetone, are not preferred.

[0014] The total solvent for the epoxidized product at the time of the epoxidation reaction (the sum of the solvent used for suspending in advance and the solvent for suspending in the solvent by adding the epoxidizing agent) The amount of) varies depending on the type of epoxidized substance, epoxidation reaction conditions, and the like.
The amount can be selected in the range of / 5 to 5 times, preferably 1/4 to 3 times, more preferably 1/2 to 2 times. If the amount of the solvent used is too small, the epoxidized product cannot be sufficiently dispersed or suspended. . Conversely, if the amount is too large, it takes a long time to remove the solvent after completion of the epoxidation reaction, and to separate and recover the product, or the equipment for storing the solvent becomes large, and neither is preferable.

In the present invention, the following three types of epoxidizing agents can be mentioned. (1) An anhydrous organic solvent solution of peracid, (2) hydrogen peroxide and carboxylic acid, or (3) hydrogen peroxide and catalyst. As the peracid, a percarboxylic acid compound such as formic acid, peracetic acid and perpropionic acid is used. As these peracids, those obtained from hydrogen peroxide and carboxylic acid or those obtained by oxygen oxidation of aldehyde can be used.

Examples of solvents for these peracids include hydrocarbons such as hexane, organic acid esters such as ethyl acetate, and aromatic hydrocarbons such as toluene.
Preferably, a solvent used for the epoxidation is used. In a system using hydrogen peroxide, hydrogen peroxide is previously reacted with a lower carboxylic acid such as formic acid or acetic acid to produce a percarboxylic acid.The percarboxylic acid is added to the reaction system as an epoxidizing agent, and the presence of a solvent is added. Epoxidation in the presence or absence of epoxidation in the presence or absence of a catalyst such as an osmium salt or tungstic acid and a solvent. In addition, the absence of a solvent as described above refers to a case where no suspending solvent is used before the start of the epoxidation reaction. Even in this case, since a solution of a peracid is used, a solvent containing a peracid, for example, water, a carboxylic acid ester such as ethyl acetate, or a glycol ether such as methoxypropylene glycol is added to the reaction system. A suspended state of the liquid polymer having a heavy bond will occur.

Examples of the solvents for these peracids include:
Hydrocarbons, organic acid esters, aromatic hydrocarbons, and the like are preferable because they are industrially easily available. The reaction temperature is 20
-80 ° C is appropriate, and particularly preferably 30-60 ° C.
The reaction pressure is sufficient at atmospheric pressure, but may be slightly reduced or slightly increased. When the reaction temperature is 2
If the temperature is lower than 0 ° C., the reaction rate is too low to be practical.
On the other hand, when the temperature exceeds 80 ° C., the peroxide self-decomposes remarkably, which is not preferable. The reaction molar ratio (peracid / double bond amount) of the double bond amount and the pure peracid content in the epoxidized product is 1.0 to 1.0.
2.0 is appropriate, and particularly preferably 1.05 to 1.3.

The oxirane oxygen concentration of the epoxidized product of the present invention, that is, the liquid epoxidized polymer, can be adjusted by appropriately changing the reaction rate of the epoxidizing agent. The reaction time varies depending on the reaction rate, but is usually 1 hour.
About 5 hours. If the reaction time is less than 1 hour, the conversion of the double bond is low and not practical. If the time is 5 hours or longer, for example, when peracetic acid is used as the peracid, the addition reaction between the epoxidized product and acetic acid increases, which causes a decrease in yield, which is not preferable.

Since the reaction product solution obtained by the method of the present invention contains by-products, carboxylic acids, solvents, etc., in addition to the target epoxidized product, the epoxidation reaction with peracid After completion, the product is produced by removing the solvent, carboxylic acid and the like by washing with water, or removing the solvent under heating or non-heating under reduced pressure or non-reduced pressure without washing with water. Note that, in the present invention, the liquid polymer having a double bond is characterized in that it can be epoxidized in a suspended state, even when suspended at the end of the epoxidation,
It may be dissolved.

In the method of the present invention, when a rubber-based polymer having a double bond is epoxidized, it is not dissolved in a solvent but is epoxidized in a suspension state, so that a large amount of a solvent is not required and the productivity is reduced. Improvement can be achieved.

[0021]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. Further, “parts” and “%” are both based on mass. The oxirane oxygen concentration and acid value of the epoxidized product were measured by the methods described below. (1) Oxirane oxygen concentration: Measured according to ASTM-1652. (2) Acid value: JIS K-0070

Example 1 A 1,000 ml four-necked round bottom flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with Kraton Liquid L-1302 (iodine number 43,
Take 300 g of a number average molecular weight 8,000, manufactured by Shell Co., Ltd.) and 300 g of ethyl acetate as a solvent, mix well, and add
Was heated. This solution was milky white and cloudy, and was added with an anhydrous 30% pure ethyl peracetate solution 155.
9 g (reaction molar ratio of double bond to peracid in the substance to be epoxidized = 1.00: 1.20) was added dropwise using a dropping funnel in about 60 minutes, and further reacted at a reaction temperature of 40 ° C for 2 hours. Matured. The reaction mass after aging was cloudy. After aging,
The solvent was removed by a thin film evaporator to produce a product, and 298.0 g of an epoxidized product (epoxidation ratio: 90.2%) was obtained. The obtained epoxidized product had an oxirane oxygen concentration of 2.40% and an acid value of 1.88 mgKOH / g.

Example 2 200 g of liquid polyisoprene LIR-290 (iodine value: 40, number average molecular weight: 25,000, manufactured by Kuraray Co., Ltd.) was placed in the same flask as in Example 1.
200 g of ethyl acetate was taken as a solvent and mixed well.
This was heated to 50 ° C., but the mixture was cloudy. Here, anhydrous 30% pure ethyl acetate acetate solution 8
4.1 g was dripped using a dropping funnel in about 30 minutes to cause a reaction, and the mixture was further aged at a reaction temperature of 50 ° C. for 3 hours. After aging, the solvent was removed by a thin film evaporator to obtain 195.3 g of an epoxidized polyisoprene (epoxidation ratio: 89.2%). The obtained epoxidized polyisoprene had an oxirane oxygen concentration of 2.21% and an acid value of 1.80 mgKOH / g.

Example 3 In the same flask as in Example 1, 100 g of Kraton Liquid L-1302, 200 g of ethyl acetate as a solvent, and 11.4 g of a 90% formic acid aqueous solution are taken and mixed well. This was heated to 50 ° C., but the solution was cloudy. Here, 30% pure hydrogen peroxide solution 3
7.8 g was charged using a dropping funnel in about 20 minutes to prepare an ethyl formate acetate solution (reaction molar ratio of double bond: performic acid in the epoxidized product = 1.00: 1.30). 4
Aged for hours. After the aging, the solvent was removed using a thin film evaporator to obtain 99.0 g of an epoxidized product (epoxidation ratio: 85
%)Obtained. The obtained epoxidized product had oxirane oxygen of 2.27% and an acid value of 2.9 mgKOH / g.

Example 4 In the same flask as in Example 1, 100 g of Kraton Liquid L-1302, 200 g of ethyl acetate as a solvent, and 1.5 g of NaWO ₄ were mixed well and mixed well. This was heated to 50 ° C., but the solution was cloudy. Here, 37.8 g of 30% pure hydrogen peroxide solution (reaction molar ratio of double bond: H ₂ O ₂ in epoxidized substance = 1.0)
0: 1.30) using a dropping funnel in about 20 minutes and aged for about 4 hours. The reaction-terminated liquid was washed twice with 200 g of ion-exchanged water. After the washing was completed, the solvent was removed using a thin film evaporator to obtain 99.0 g of an epoxidized product (epoxidation ratio: 88%). The obtained epoxidized product had an oxirane oxygen of 2.35% and an acid value of 2.7 mgKOH / g.

Comparative Example 1 In the same flask as in Example 1, 100 g of Kraton Liquid L-1302 and 800 g of ethyl acetate as a solvent were taken and dissolved. At 40 ° C
Was heated. This solution was clear. Purity 3 here
51.9 g of a 0% ethyl peracetate solution was reacted dropwise using a dropping funnel in about 60 minutes, and further aged at a reaction temperature of 40 ° C. for 3 hours. After aging, the solvent was removed using a thin film evaporator, and 98.7 g of an epoxidized product (epoxidation ratio: 96
%)Obtained. The obtained epoxidized product had oxirane oxygen of 2.56% and an acid value of 2.7 mgKOH / g. Thus, a large amount of solvent was required to obtain a uniform reaction raw material solution.

[0027]

According to the present invention, when epoxidizing a liquid rubber polymer insoluble or having low solubility in an organic solvent, a large amount of solvent is required by epoxidizing in a suspended state without dissolving in a solvent. And productivity can be improved.

Claims (6)

[Claims] 1. A liquid polymer having a double bond which is insoluble or has low solubility in an organic solvent, is previously suspended in the solvent, or is suspended in the solvent by adding the following epoxidizing agent. And (2) epoxidation using an anhydrous organic solvent solution of peracid or (2) hydrogen peroxide and a catalyst as an epoxidizing agent. 2. The process for producing a liquid epoxidized polymer according to claim 1, wherein the peracid is derived from hydrogen peroxide. 3. The method for producing a liquid epoxidized polymer according to claim 1, wherein the peracid is obtained by oxygen oxidation of an aldehyde. 4. The polymer according to claim 1, wherein the polymer has a unit composed of a diene monomer.
The method for producing a liquid epoxidized polymer according to any one of claims 1 to 3. 5. The polymer according to claim 2, wherein the polymer contains a diene monomer.
The method for producing a liquid epoxidized polymer according to claim 4, wherein the method is a block of at least one kind or a random copolymer. 6. The method according to claim 1, wherein the solvent that causes the suspension of the liquid polymer having a double bond is water, a carboxylic acid ester, a glycol ether, or a mixture thereof. A method for producing a liquid epoxidized polymer according to any one of the above.