JPH0148923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polymer containing glycidyl acrylate or glycidyl methacrylate (hereinafter abbreviated as glycidyl (meth)acrylate) by a solution polymerization method.

When performing solution polymerization for homopolymerization of glycidyl (meth)acrylate or copolymerization with other polymerizable vinyl monomers, popcorn polymers are often formed after the middle stage of the reaction, or the entire reaction system often gels. happen.

To improve this point, Japanese Patent Publication No. 1985-8594 discloses a method in which t-butyl peroxypivalate or diisopropyl peroxydicarbonate is used as a polymerization initiator and the reaction is carried out at 20 to 55°C. However, sometimes the entire reaction system turns into a gel.

In the method described in JP-A-54-155295, in order to obtain a half-life of 10 hours, an organic peroxide whose decomposition temperature is 60°C or less is used as a polymerization initiator, and the temperature is 10 to 50°C higher than the decomposition temperature. The above disadvantages have been improved by adding the organic peroxide in two or more portions to the reaction system, but since a highly active initiator is used, handling is difficult. However, the method itself is complicated, such as adding in portions. It was also found that copolymerization of glycidyl (meth)acrylate with a monomer having a functional group such as a hydroxyl group causes gelation, and that this method also has its limitations.

Regarding the copolymerization of glycidyl (meth)acrylate and hydrophilic vinyl monomer,
Although it is also described in the example of JP-A No. 52-92290,
When this method was repeated, gelation still occurred when trying to increase the polymerization rate.

In order to overcome these drawbacks of the prior art, the present inventors conducted extensive research and developed a method for producing glycidyl (meth)acrylate homopolymers or copolymers with other vinyl monomers by gelling or submerging them. We have discovered a method for obtaining it without involving any reaction, leading to the present invention.

That is, in the present invention, a radical polymerization initiator is added and dissolved in glycidyl (meth)acrylate or a mixture of one or two of these and one or more other polymerizable vinyl monomers, and this mixed solution is A method for producing a polymer containing glycidyl (meth)acrylate, characterized in that the polymerization initiator is added to a solvent maintained at a temperature higher than the temperature at which the polymerization initiator obtains a half-life of 10 hours.

In the present invention, even if a compound having a functional group such as a hydroxyl group that can react with an epoxy group is used as another vinyl monomer or a solvent, a polymer can be obtained without gelation or side reactions, and the polymer can be co-produced. In case of polymerization,
A distinctive feature not seen in the prior art is that it can be applied to any composition ratio.

As polymerizable vinyl monomers that can be copolymerized,
Methyl acrylate and methyl methacrylate (hereinafter acrylic acid and methacrylic acid derivatives are abbreviated as (meth)acrylic acid derivatives), alkyl (meth)acrylates such as ethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl ( Hydroxyl group-containing (meth)acrylates such as meth)acrylate, diethylene glycol mono(meth)acrylate,
Examples include styrene, (meth)acrylonitrile, and vinyl acetate.

Solvents used in the present invention include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ethers such as acetic acid esters, diethyl carbitol, and diethyl cellosolve, methyl cellosolve, and ethyl Examples include ether alcohols such as cellosolve and carbitol, and ester ethers such as cellosolve acetate and carbitol acetate, and a hydrocarbon solvent may be used in combination if necessary.

The polymerization initiator may be any one known as a radical polymerization initiator, such as azobisisobutylnitrile, benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypivalate, methyl ethyl ketone peroxide. , dicumyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, and the like.

The amount of the initiator added needs to be changed depending on the reaction temperature, the molecular weight of the desired polymer, etc., but the preferable amount is 1 to 5% by weight based on the total amount of monomers.

The reaction temperature is closely related to the polymerization initiator used, and it needs to be higher than the temperature at which the polymerization initiator has a half-life of 10 hours (hereinafter abbreviated as T1/2°C). It is an essential condition of the present invention that the mixture of monomer and initiator be added to the solvent maintained at or above .degree. Conversely, in a method in which an initiator or an initiator diluted with a solvent is added to a monomer or a mixture of a monomer and a solvent kept at T1/2°C or above, or all components are added from the beginning and reacted, Side reactions such as gelation and ring opening of epoxy groups occur, making it impossible to obtain the desired polymer.
The preferred reaction temperature is (T1/2+10)℃~(T1/2
+50)℃.

According to the method of the present invention, no gelation or side reactions occur during the reaction, and a polymer with a polymerization rate of 95% or more can be easily obtained.

Next, the present invention will be explained using Examples and Comparative Examples.

Example 1 560 g of ethyl cellosolve was charged into a four-necked flask equipped with a stirring bar, a thermometer, a nitrogen inlet tube, a dropping funnel, and a reflux condenser, and the system was purged with nitrogen. Thereafter, the temperature was raised to 90°C, and 120 g of glycidyl methacrylate, 120 g of hydroxyethyl methacrylate, and 7.2 g of azobisisobutyronitrile were added.
(3% by weight based on the monomer) was mixed and dissolved in advance and added dropwise over 1 hour. After dropping, the solution was kept at the same temperature for 2 hours to obtain a copolymer solution of glycidyl methacrylate and hydroxyethyl methacrylate. The epoxy equivalent of the obtained polymerization solution was 966, which was almost in agreement with the theoretical value of 956. Further, the number average molecular weight of the copolymer was 7000, and the polymerization rate was 95%.

Comparative Example 1 In Example 1, glycidyl methacrylate and hydroxyethyl methacrylate were placed in a flask in advance, the temperature was raised to 90°C, and 7.2 g of asobisisobutyronitrile was added to ethyl cellosolve 560.
When using the method of dropping a solution dissolved in g,
In addition, when all the components were charged into a flask from the beginning and then heated to 90°C for reaction, a side reaction occurred and some of the epoxy groups of the resulting polymer were ring-opened. Furthermore, when the reaction was carried out at 60°C using this method, the entire reaction system turned into a gel.

Example 2 Methyl cellosolve 420 was added to the same apparatus as in Example 1.
g was charged, and the system was purged with nitrogen. Then 100℃
Glycidyl methacrylate
162g, hydroxyethyl methacrylate 18g,
A premixed solution of 3.2 g of benzoyl peroxide (3% by weight based on the monomer) was dropped over a period of 2 hours, and after the dropwise addition, the mixture was kept at the same temperature for 2 hours. The epoxy equivalent of the obtained polymerization solution was 540, which was almost in agreement with the theoretical value of 530. In addition, the number average molecular weight of the copolymer is
5000, and the polymerization rate was 97%.

Comparative Example 2 When the reaction was carried out in the same manner as in Example 2 except that the reaction temperature was 50°C, a side reaction occurred and some of the epoxy groups in the resulting polymer were ring-opened.

Claims (1)

[Scope of Claims] 1 A radical polymerization initiator is added and dissolved in glycidyl acrylate or glycidyl methacrylate, or a mixture of one or two of these and one or more other polymerizable vinyl monomers, A method for producing a polymer containing glycidyl acrylate or glycidyl methacrylate, characterized in that the mixed solution is added to a solvent maintained at a temperature higher than the temperature at which the polymerization initiator obtains a half-life of 10 hours. 2. The production according to claim 1, wherein the other polymerizable vinyl monomer is an acrylic acid alkyl ester, a methacrylic acid alkyl ester, a hydroxyl group-containing acrylate, a hydroxyl group-containing methacrylate, styrene, acrylonitrile, methacrylonitrile, or vinyl acetate. Law. 3. Claims 1 or 2, characterized in that the solvent is mainly composed of a compound having one or more functional groups selected from hydroxyl group, ketone group, ether group, and ester group. Manufacturing method described.