JPS6213420A - Production of alpha, beta-unsaturated dicarboxylic acid anhydride polymer - Google Patents

Abstract

PURPOSE:To obtain the title polymer stably in good yield and efficiency by preventing the deposition of polymer on the wall and the like areas of a polymerization kettle, by radicalpolymerizing an alpha, beta-unsaturated dicarboxylic acid anhydride in the presence of a specified dispersant and a poor solvent. CONSTITUTION:100pts.wt. monomer (mixture) comprising an alpha, beta-unsaturated dicarboxylic acid anhydride (e.g., maleic anhydride) and, optionally, 0-30mol% other copolymerizable monomers such as linear or cyclic monoolefins is (co) polymerized in a state of suspension at 70-200 deg.C for 2-12hr by using 1-30pts. wt. radical initiator such an an organic peroxide in the presence of 0.5-10pts.wt. dispersant comprising atactic polypropylene of a MW of 1,000-100,000 and a poor solvent (e.g., pentane).

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing an α,β-unsaturated dicarboxylic acid anhydride polymer, and more particularly, it relates to a method for efficiently producing an α,β-unsaturated dicarboxylic acid anhydride polymer by slurry polymerization. The present invention relates to a method for producing a dicarboxylic acid anhydride polymer.

(Prior art) A polymer of α,β-unsaturated dicarboxylic acid anhydride represented by maleic anhydride (hereinafter sometimes referred to as polydicarboxylic acid) tlj: itself or an alkali metal salt,
Epoxy hardeners, ink and adhesive additives, dye and pigment dispersants, in the form of ammonium salts, esters, etc.
It is known to be used in fields such as detergent builders, textile treatment agents, and water treatment agents.

It is known that such polydicarboxylic acids are generally obtained by dissolving an α,β-unsaturated dicarboxylic anhydride in an inert organic solvent and polymerizing it using a radical polymerization catalyst. For example, according to Japanese Patent Publication No. 53-201475, a polymer is produced by polymerizing a small amount of maleic anhydride (for 3 hours at 70 to 120°C) using toluene as a solvent and benzoyl peroxide as a polymerization initiator. Maleic anhydride is obtained in high yield.

However, in such conventional methods, the product precipitates from the bath liquid as a black colored tar-like substance, as is clear from the examples. Therefore, the purification method is complicated, and the troublesome operation of heating the tar-like substance into a small amount of methyl ethyl ketone, precipitating the polymer with a large amount of toluene, and then separating the resulting product is complicated.

In addition to complicating the purification process, there are other problems caused by the tar-like nature of the product, such as the large amount of energy required for stirring, the blockage of the equipment, and the build-up of polymers on the walls of the vessel. There were problems such as the occurrence of adhesion and the mixing of unreacted maleic anhydride into the product, resulting in a decrease in conversion rate.

(Problems to be Solved by the Invention) Therefore, the present inventors have attempted to solve these drawbacks of the prior art (
As a result of intensive research, it was discovered that by using a specific dispersant, polydicarboxylic acid could be produced not as a tar-like substance (but as a powder slurry), and based on this knowledge, the present invention was completed.

(Another means to solve the problem) According to the present invention, α,β-unsaturated di5
Provided is a method for producing an α,β-unsaturated dicarboxylic acid anhydride polymer, which comprises radically polymerizing a carboxylic acid anhydride.

The α,β-unsaturated dicarboxylic acid anhydride used as a monomer in the present invention may be any one commonly used in this technical field (specific examples include maleic anhydride, Examples include those having 4 to 10 carbon atoms, such as itaconic acid and citraconic anhydride.Among them, maleic anhydride is prized for its reactivity, quality, economical efficiency, and the like.

Two or more of these monomers may be used in combination as necessary (and other comonomers that can be copolymerized may be used in combination within a range that does not essentially change the performance of the product). You can also do it.

Specific examples of comonomers that can be used in combination include ethylene,
7' Robylene, Isobutyne, Butene-1, Butene-2,
Pentene-1, Pentene-2,2-methylbutene-1,
Chain monoolefins such as 2-methylbutene-2, hexene-1,2,2,4-trimethylpentene-1,2,2,4-trimethylpentene-2, decene-1, etc., cyclopentene, cyclohexene, cyclooctene Examples include tricyclic monoolefins such as styrene, α-methylstyrene, and aromatic monoolefins such as vinyltoluene, and these are used in a proportion of 30 mole or less, preferably 20 mole or less in the total monomer. It will be done.

The polymerization of the present invention is carried out in an antisolvent in the presence of atactic polypropylene. As atactic polypropylene, those with molecular t of 1,000 to 100,000, which are produced as by-products during the production of poly 1 and ropylene (crystalline polypropylene), are prized, but the manufacturing method is not limited to .

The amount of dispersant used is usually 0.5 to 10 parts by weight, preferably 1.0 to 5 parts by weight per 100 M parts of the monomer component. The effect of suppressing the production is small (on the contrary, if there is a large amount, it is economically disadvantageous).

Furthermore, in the present invention, a poor solvent, that is, a solvent that does not dissolve the produced polymer, is used as the polymerization solvent. Specific examples of such poor solvents include linear, branched, or cyclic aliphatic hydrocarbons such as butane, pentane, hexane, hexanes, octane, decane, ligroin, and cyclohexane, benzene, and toluene. , aromatic hydrocarbons such as xylene, chlorobenzene, etc.

In the present invention, polymerization is carried out according to a conventional method in the presence of the above-mentioned poor solvent and dispersant.

The catalyst used in the reaction is cumene hydroperoxa ()
”, t-butyl human peroxide, di-t-butyl peroxide, benzoyl peroxide, diisoglobil peroxydicarbonate, t-butyl peroxy 7-biparate, etc., α,α′-azobis Radical initiators such as azobis compounds such as isobutyronitrile, α, α′-azo α-ethylbutyronitrile, redox catalysts, etc., and are not limited to (but are not limited to) radical initiators. The amount of such catalyst used is usually per 100 parts by weight of monomer components!
It is 11 to 3 ONth parts, preferably 5 to 20 heavy ships parts.

Polymerization is usually carried out at 70 to 200°C, preferably 90 to 15°C.
It is carried out in suspension at 0° C. for 2 to 12 hours.

(Effects of the Invention) Thus, according to the present invention, the problems associated with the production of oily substances as described above can also be solved. In other words, it is possible to operate stably for a long period of time without cleaning the polymerization reactor, and it is possible to obtain polymers with high yield and efficiency.It is also possible to produce polymers in a powder or suspension state. It is possible to transfer, separate, wash, and
aS etc. become easy, and the manufacturing process can be simplified.

(Example) The present invention will be described in more detail with reference to Examples below. In addition, parts and weights in the examples are based on weight unless otherwise specified. In addition, in the examples, Bistac-L (manufactured by Chiba Fine Chemical Co., Ltd., atactic polypropylene) as a dispersant, molecular weight, s, ooo~15,000
, a softening point of ion to 155°C was used.

Example 1 196 parts of maleic anhydride was charged into a 32 autoclave equipped with a stirrer, the can was sealed, and the system was then purged with gold and nitrogen. After adding a total of 1000 parts of loupentane under reduced pressure, the temperature was raised to 130 ° C. A predetermined amount of BISTAC as a dispersant
25 parts of L and di-t-butyl peroxide were added over a period of 1 hour. Thereafter, the mixture was heated and stirred at the same temperature for 6 hours to effect polymerization. After the polymerization reaction was completed, the produced polymer was taken out through a valve at the bottom of the polymerization vessel, and its conversion rate was measured. The conditions inside the polymerization system and the occurrence of clogging of the bottom pulp were also observed. The results are shown in Table 1.

Table 1 The conversion rate was measured using a high performance liquid chromatograph.
Amount of unreacted maleic anhydride t - Conversion rate of maleic anhydride calculated by measurement.

Example 2 400 parts of maleic anhydride was charged into a 31 autoclave equipped with a stirrer, the can was sealed, and the system was then purged with gold and nitrogen. Then, 35 parts of pentene-1, 120 parts of lupentane I, and 1500 parts of Zyi were added under reduced pressure. Thereafter, the temperature was raised to 130°C, and at the same temperature, 8 parts of Vistax L and 50 parts of di-t-butyl peroxide were added as a dispersant over 1 hour. Thereafter, the mixture was heated and stirred at the same temperature for 6 hours to effect polymerization.

As a result, the conversion rate was 75%, and the product was a yellow powder slurry. In addition, there was no clogging of the bottom valve, and no oily substance was observed after the slurry was extracted□

Claims (1)

[Claims] 1. A method for producing an α,β-unsaturated dicarboxylic anhydride polymer, which comprises radically polymerizing an α,β-unsaturated dicarboxylic anhydride in the presence of atactic polypropylene and a poor solvent.