JP4716539B2 - Method for producing liquid epoxidized polymer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a liquid epoxidized polymer used in paints, resin modifiers, rubber modifiers, adhesives and the like. More specifically, when a double bond in a molecular chain of a liquid polymer is converted into an epoxy group using peracids, an anhydrous peracid, a peracid derived from hydrogen peroxide, or hydrogen peroxide and a catalyst Is used to improve the productivity of a liquid epoxidized polymer by suspending the polymer in a solvent and performing epoxidation.
[0002]
[Prior 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 this anhydrous percarboxylic acid solution is added to the reaction system as an epoxidizing agent, and 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. To perform epoxidation reaction.
(3) A method of epoxidation using hydrogen peroxide in the presence of a catalyst such as an osmium salt or a tungstic acid and a solvent.
Usually, when performing epoxidation by these methods, the epoxidation target polymer is dissolved in a solvent, and epoxidation is performed. This is to obtain a high epoxidation rate by performing epoxidation in a homogeneous phase.
In addition, percarboxylic acid is called peracid.
[0003]
However, when the polymer to be epoxidized is soluble in an organic solvent, the epoxidized product can be easily recovered by desolvation operation, but the polymer to be epoxidized is insoluble in the organic solvent or In the case of a liquid having low solubility, a liquid product is precipitated when the solvent is removed, 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 workability is remarkably deteriorated.
In the case of a liquid polymer, epoxidized materials such as liquid polybutadiene and polyisoprene are used because curing with an acid or a cationic species is possible by introducing an epoxy group.
Since these liquid polymers generally have good compatibility with solvents such as esters and aromatics, there is no particular problem with the recovery of products after epoxidation.
[0004]
However, for example, some liquid polyisoprene has extremely low solubility in a solvent.
In general, epoxidation is more efficient when dissolved in a solvent, so when epoxidizing a polymer with low solubility, it is necessary to use a large amount of solvent. Often becomes.
[0005]
In the prior art, for example, in Japanese Patent Laid-Open No. 56-11904, 1,300 parts of benzene is added to 500 parts of liquid polybutadiene and dissolved, and 700 parts of 30% hydrogen peroxide water is added thereto to suspend it. A method is disclosed in which a suspension is obtained and formic acid is added to the resulting suspension for epoxidation.
In this method, the efficiency of the transfer of the oxidant is poor between the large amount of benzene solvent system used for dissolving the liquid polybutadiene and the hydrogen peroxide solution system, but the transfer is even worse, especially because formic acid is used. The epoxidation rate by this method is 0.19 per butadiene constitutional unit, and compared with the oxirane oxygen concentration of epoxidized polybutadiene which is currently commercially available, the epoxidation method is a very good method. I can't say that.
[0006]
Japanese Patent Application Laid-Open No. 9-165418 exemplifies epoxidation in a suspended state, but this is epoxidation of a solid material, and product recovery should be performed in the same manner as a normal solid product. It is something that can be done.
In the case of the present invention in which a liquid polymer having low solubility in a solvent is epoxidized, the product cannot be recovered by filtration or centrifugation, so that the situation is different from the technique described in JP-A-9-165418. .
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing a liquid epoxidized polymer with high productivity by using a liquid polymer having a double bond and an epoxidizing agent.
[0008]
[Means for Solving the Problems]
In such a situation, the inventors have improved the productivity by epoxidizing 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, the present invention has been completed.
[0009]
That is, the first of the present invention is a liquid polymer having a double bond, and a polymer having a unit composed of a diene monomer is previously suspended in ethyl acetate, or the following epoxidation: In addition to the suspension in ethyl acetate by adding an agent, an anhydrous ethyl acetate solution of peracetic acid obtained by oxygen oxidation of aldehyde is used as an epoxidizing agent, and the amount of all solvents used is the epoxidized product. Provided is a method for producing a liquid epoxidized polymer, characterized by epoxidizing a liquid polymer having a double bond in an amount of 1/2 to 2 times by mass .
A second aspect of the present invention is the method for producing a liquid epoxidized polymer according to the first aspect of the present invention, wherein the polymer is two or more kinds of blocks containing a diene monomer or a random copolymer. I will provide a.
In the present specification, in addition to the above-mentioned invention, a liquid polymer having a double bond insoluble in organic solvent or having low solubility is suspended in a solvent in advance, or the following epoxidizing agent is added. To make it suspended in a solvent,
As an epoxidizing agent,
(1) An anhydrous organic solvent solution of peracid,
A method for producing a liquid epoxidized polymer, characterized by (2) hydrogen peroxide and carboxylic acid or (3) epoxidation using hydrogen peroxide and a catalyst, is also described.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a liquid epoxidized polymer is produced by epoxidizing a liquid polymer, in particular, a polymer having a portion composed of a diene monomer, among liquid rubbers that are usually commercially available, in a suspended state. It is.
[0011]
The present invention is described in detail below.
In the present invention, the liquid polymer used for epoxidation is not particularly limited as long as it has a double bond in the molecule, but it may be a single monomer polymer or a polymer of two or more monomers. Absent. In the case of two or more kinds of polymers, a block copolymer or a random copolymer may be used.
Examples of the polymer of a single diene monomer include polybutadiene, polyisoprene, polybutylene and the like.
As monomers that can constitute the copolymer, typical examples of vinyl aromatic hydrocarbon compounds include, for example, various alkylene-substituted styrenes such as styrene and α-methylstyrene, alkoxy-substituted styrenes, vinyl naphthalene, and alkyl-substituted vinyl naphthalene. , Divinylbenzene, vinyltoluene and the like.
Also, ethylene, propylene, or the like can be used. One or a combination of two or more of these can be used.
[0012]
Representative examples of the diene compound that can constitute the block copolymer include, for example, 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl- Examples include 1,3-octadiene and phenyl-1,3-butadiene.
Further examples include dicyclopentadiene, cyclopentadiene, and ethylidene norbornene having an alicyclic skeleton. Among these, you may combine 1 type or 2 types or more.
There is no restriction | limiting in the copolymerization composition ratio (mass ratio) of the vinyl aromatic hydrocarbon compound and conjugated diene compound which can comprise a block copolymer.
These polymers having a double bond in the molecule (hereinafter also abbreviated as epoxidized product).
) Is not particularly limited.
It is desirable from the viewpoint of workability when handling raw materials and products that it is liquid at room temperature. If it is liquid at normal temperature, there is no restriction | limiting in particular also about the terminal group of these epoxidized materials.
Examples of such compounds include Clayton Liquid L-1302 (manufactured by Shell, number average molecular weight 8,000, iodine value 43) which is a liquid diene block copolymer, and LIR-290 (Kuraray) which is a liquid polyisoprene. Manufactured, number average molecular weight 25,000, iodine value 40) and the like.
[0013]
In the present invention, a liquid polymer having a double bond having low solubility (that is, epoxidized in a suspended state) is used to epoxidize the polymer in a suspended state in advance in a solvent. The organic solvent to be used is an organic solvent soluble in water by 0.5 to 10% by weight, preferably 1 to 6% by weight, more preferably 2 to 5% by weight, and the following compounds are suitable.
Specifically, lower alcohol esters having 1 to 4 carbon atoms of lower carboxylic acids having 1 to 5 carbon atoms such as methyl acetate, ethyl acetate, butyl acetate, methyl butyrate and methyl isobutyrate; Or a lower alcohol ether having 1 to 4 carbon atoms of a glycol having 2 to 4 carbon atoms such as dimethyl ether; 1 to 4 carbon atoms of a glycol having 2 to 4 carbon atoms such as mono- or diacetate of ethylene glycol or propylene glycol Lower carboxylic acid esters; lower alcohol ethers having 1 to 4 carbon atoms of 1 to 4 carbon atoms of glycols having 2 to 4 carbon atoms such as methoxypropylene glycol acetate; mono- or diethylene glycol or dipropylene glycol Diacetate S Polyether esters such as Le; nitriles such as acetonitrile; and the like halogenated hydrocarbons such as chloroform.
Among these, it is desirable to use ethyl acetate or the like because of the low solubility of the epoxidized product and the ease of subsequent organic solvent recovery.
Further, in the present invention, as a solvent for producing a suspended state by adding an epoxidizing agent to a liquid polymer having a double bond, since it contains a peracid, water, the above lower carboxylic acid and lower alcohol Examples include esters, glycol ethers, or mixtures thereof.
In particular, the solvent used in the epoxidation reaction may be difficult to recover when the produced liquid epoxidized product is dissolved. Therefore, it is desirable to use a solvent having the lowest solubility of the liquid epoxidized product.
Accordingly, hexane, octane, cyclohexane, cycloheptane, benzene, toluene, xylene, naphthalene and the like alone are not preferable because of their low solubility in water. However, it can be used if it is prepared so as to have the above-mentioned solubility in water as a mixed solvent.
In addition, a solvent in which the solvent itself is oxidized by a peracid, such as ketones such as acetone, is not preferable.
[0014]
Total solvent for the epoxidized product during the epoxidation reaction (this is the total of the solvent to be suspended in the solvent by adding the epoxidizing agent and the solvent used to make the suspension in advance) )) Varies depending on the type of epoxidized product, epoxidation reaction conditions, etc., but is 1/5 to 5 times, preferably ¼ times the mass of the epoxidized product on a mass basis. It can be selected in a range of ˜3 times, more preferably ½ times to 2 times.
If the amount of solvent used is less than the above range, the epoxidized product cannot be sufficiently dispersed or suspended, resulting in a prolonged reaction due to a decrease in the reaction efficiency of epoxidation, poor liquid feeding by a pump, etc. . On the other hand, if the amount is too large, it takes a long time for solvent removal and product separation / recovery operation after the epoxidation reaction, and the equipment for storing the solvent becomes large.
[0015]
In the present invention, examples of the epoxidizing agent include the following three types.
(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.
These peracids can be used either from hydrogen peroxide and carboxylic acid or from aldehyde oxygen oxidation.
[0016]
Examples of these peracid solvents include hydrocarbons such as hexane, organic acid esters such as ethyl acetate, and aromatic hydrocarbons such as toluene. Preferably, the peracid solvent is used for the epoxidation. A solvent is mentioned.
In a system using hydrogen peroxide, hydrogen peroxide and a lower carboxylic acid such as formic acid or acetic acid are reacted in advance to produce a percarboxylic acid, and this percarboxylic acid is added to the reaction system as an epoxidizing agent, and the presence of a solvent. There are a case where the epoxidation reaction is performed in the presence or absence of hydrogenation, and a method in which hydrogen peroxide is epoxidized in the presence of a catalyst such as an osmium salt, tungstic acid and a solvent.
The term “in the absence of a solvent” as used above refers to the case where a suspending solvent is not used before the start of the epoxidation reaction. Even in this case, since a peracid solution 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 a liquid polymer having a heavy bond will occur.
[0017]
As these peracid solvents, for example, hydrocarbons, organic acid esters, aromatic hydrocarbons and the like are desirable because they are easily available industrially.
The reaction temperature is suitably 20 to 80 ° C, particularly preferably 30 to 60 ° C. The reaction pressure is sufficient under atmospheric pressure, but it may be slightly reduced or slightly increased.
When the reaction temperature is less than 20 ° C., the reaction rate is small and not practical. On the other hand, if it exceeds 80 ° C., the self-decomposition of the peroxide becomes remarkably unfavorable.
The reaction molar ratio (peracid / double bond amount) of the double bond amount and the pure peracid content in the epoxidized product is suitably 1.0 to 2.0, particularly 1.05 to 1.3. preferable.
[0018]
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 ratio of the epoxidizing agent.
The reaction time varies depending on the reaction rate, but is usually about 1 to 5 hours. When the reaction time is less than 1 hour, the double bond conversion rate is low and impractical. If it is 5 hours or more, for example, when peracetic acid is used as the peracid, the addition reaction between the epoxidized product and acetic acid increases, which is not preferable because it causes a decrease in yield.
[0019]
Since the reaction product obtained by the method of the present invention contains by-products, carboxylic acid, solvent, etc. in addition to the epoxidized product, the epoxidation reaction with peracid is completed. The product is produced by removing the solvent, carboxylic acid, or the like by washing with water, or removing the solvent in a heated or non-heated state under reduced pressure or non-depressurized without washing with water.
In the present invention, a liquid polymer having a double bond can be epoxidized in a suspended state, and may be suspended or dissolved at the end of epoxidation.
[0020]
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 and epoxidized in a suspended state, so that a large amount of solvent is not required and productivity is improved. be able to.
[0021]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Examples 3 and 4 are described as reference examples.
“Parts” and “%” are both based on mass.
The oxirane oxygen concentration and acid value of the epoxidized product were measured by the method described below.
(1) Oxirane oxygen concentration: measured in accordance with ASTM-1652.
(2) Acid value: JIS K-0070
[0022]
[Example 1]
In a 1,000 ml four-necked round bottom flask equipped with a thermometer, a stirrer, and a reflux condenser, 300 g of Clayton Liquid L-1302 (iodine number 43, number average molecular weight 8,000, manufactured by Shell), As a solvent, 300 g of ethyl acetate was taken, mixed well, and heated to 40 ° C. This solution was milky white and cloudy, but was then added 155.9 g of anhydrous 30% pure ethyl acetate solution (double molar ratio of epoxidized compound: peracid reaction molar ratio = 1.00: 1). 20) was dropped using a dropping funnel in about 60 minutes, and further aged at a reaction temperature of 40 ° C. for 2 hours. The reaction mass after aging was cloudy.
After completion of the aging, the solvent was removed by a thin film evaporator to produce a product, and 298.0 g of an epoxidized product (epoxidation rate: 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.
[0023]
[Example 2]
In the same flask as in Example 1, 200 g of liquid polyisoprene LIR-290 (iodine value 40, number average molecular weight 25,000, manufactured by Kuraray Co., Ltd.) and 200 g of ethyl acetate as a solvent were mixed well. This was heated to 50 ° C., but the mixed solution was cloudy. Thereto, 84.1 g of an anhydrous ethyl acetate solution with a purity of 30% was dropped for about 30 minutes using a dropping funnel, and the mixture was aged at a reaction temperature of 50 ° C. for 3 hours.
After completion of the aging, the solvent was removed by a thin film evaporator to obtain 195.3 g (epoxidation rate: 89.2%) of epoxidized polyisoprene. The obtained epoxidized polyisoprene had an oxirane oxygen concentration of 2.21% and an acid value of 1.80 mgKOH / g.
[0024]
[Example 3]
In the same flask as in Example 1, 100 g of Clayton Liquid L-1302, 200 g of ethyl acetate and 11.4 g of 90% aqueous formic acid solution are taken and mixed well. This was heated to 50 ° C., but the solution was cloudy. Into this, 37.8 g of 30% pure hydrogen peroxide water was charged using a dropping funnel in about 20 minutes, and an ethyl formate acetate solution (double bond in epoxidized product: reaction molar ratio of formic acid = 1.00). : 1.30) and then aged for about 4 hours.
After completion of aging, the solvent was removed using a thin film evaporator to obtain 99.0 g of an epoxidized product (epoxidation rate: 85%). The obtained epoxidized product had an oxirane oxygen of 2.27% and an acid value of 2.9 mgKOH / g.
[0025]
[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 are mixed well. This was warmed to 50 ° C., but the solution was cloudy. Here, 37.8 g of 30% pure hydrogen peroxide water (reaction molar ratio of double bond in epoxidized substance: H ₂ O ₂ = 1.00: 1.30) was added in about 20 minutes using a dropping funnel. Prepared and aged for about 4 hours. This reaction completion liquid was washed twice with 200 g of ion-exchanged water.
After completion of the cleaning, the solvent was removed using a thin film evaporator to obtain 99.0 g of an epoxidized product (epoxidation rate 88%). The obtained epoxidized product had an oxirane oxygen of 2.35% and an acid value of 2.7 mgKOH / g.
[0026]
[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. This was warmed to 40 ° C. This solution was clear. Thereto, 51.9 g of a 30% pure ethyl acetate solution was dropped for about 60 minutes using a dropping funnel, and further aged at a reaction temperature of 40 ° C. for 3 hours.
After completion of the aging, the solvent was removed using a thin film evaporator to obtain 98.7 g of an epoxidized product (epoxidation rate 96%). The obtained epoxidized product had an 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]
【The invention's effect】
In the present invention, when epoxidizing a liquid rubber polymer that is insoluble or low in solubility in an organic solvent, it is not dissolved in a solvent and epoxidized in a suspended state, so that a large amount of solvent is not required and productivity is improved. Improvements can be made.

Claims (2)

A liquid polymer having a double bond, wherein a polymer having units composed of a diene monomer is suspended in ethyl acetate in advance or ethyl acetate is added by adding the following epoxidizing agent. An anhydrous ethyl acetate solution of peracetic acid obtained by oxygen oxidation of an aldehyde is used as an epoxidizing agent, and the amount of all solvents used is a liquid heavy compound having the above-mentioned double bond as an epoxidized product. A method for producing a liquid epoxidized polymer, characterized in that epoxidation is carried out in an amount of 1/2 to 2 times the mass of the coalescence. Polymer, two or more blocks or comprising monomers of diene, manufacturing method of the liquid epoxidized polymers of claim 1, wherein the random copolymer.