JPH0254841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an olefin-maleic anhydride copolymer, and more specifically, the present invention relates to a method for producing an olefin-maleic anhydride copolymer. The present invention relates to a method for producing an olefin-maleic anhydride copolymer that can be used for various purposes. Conventionally, a method for producing an olefin-maleic anhydride copolymer by copolymerizing an olefin and maleic anhydride has been known. Various aliphatic and aromatic hydrocarbons are known to be used as solvents for producing this copolymer, but none of these solvents dissolve the copolymer produced and precipitate it out of the system. This production method was the so-called precipitation copolymerization method. In this case, there was a problem that the copolymer adhered to the inner wall of the reactor and the stirring blade. Furthermore, when this copolymer is used as an adhesive, a paint, etc., it is necessary to prepare the copolymer as an alkaline aqueous solution and mix it with certain additives. Therefore, the present inventors have searched for various solvents that allow the copolymerization reaction to proceed smoothly and dissolve the resulting copolymer, and have found that the above objective can be achieved when an organic solvent with a specific solubility constant is used. Based on this knowledge, we have completed the present invention. That is, the present invention is characterized in that when an olefin and maleic anhydride are radically copolymerized to produce an olefin-maleic anhydride copolymer, an organic solvent having a solubility coefficient of 11 or more is used as a polymerization solvent. A method for producing an olefin-maleic anhydride copolymer is provided. In the present invention, various olefins can be used. For example, ethylene, propylene,
Examples include butylene, 1-pentene, etc., and a butane-butene fraction obtained by removing butadiene from a 4-carbon fraction obtained by thermal decomposition of petroleum is particularly preferred. This fraction is mainly composed of isobutylene, and also contains 1-butene, 2-trans-butene,
Includes cis-butene-2, isobutene, and the like. The blending amounts of the above olefin and maleic anhydride are not particularly limited and may be determined depending on the physical properties of the desired olefin-maleic anhydride copolymer, but usually the molar ratio of maleic anhydride to olefin is 1. The above ratio is preferably used, and the ratio of the former to the latter is preferably as close as possible to 1:1. Furthermore, a catalyst is used to carry out the radical copolymerization. Various radical catalysts can be used as the catalyst here, but usually benzoyl peroxide, lauroyl peroxide, cumene hydroxide, t
Examples include peroxides such as -butyl hydroperoxide and dicumyl peroxide, azo compounds such as azobisisobutyronitrile, and superphosphates. The amount of catalyst used is 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of all monomers. The catalyst can be used as is or diluted. The addition timing may be all at the beginning of the polymerization, or it may be added in parts during the polymerization. The solvent used in the present invention is an organic solvent having a solubility coefficient of 11 or more, preferably 11 to 13. The solubility coefficient is a characteristic value of liquids that is a measure of miscibility between liquids. A solvent with a solubility coefficient of less than 11 hardly dissolves the copolymer and precipitates outside the polymerization reaction system. Specific examples of organic solvents with a solubility coefficient of 11 or higher include acetonitrile (11.9), dimethyl sulfoxide (12.0), acetylmorpholine (11.6), acetylpiperidine (11.2), acetylpyrrolidine (11.4), acrylic acid (12.0), Aryl alcohol (11.8), benzyl alcohol (12.1), butanediol-1,3 (11.6), butanediol-1,
4 (12.1), butanediol-2,3 (11.1), butyl alcohol (11.4), N,N-dimethylformamide (12.1), nitromethane (12.7), nitroethane (11.1), and the like. In this way, the solvent used in the present invention needs to have a solubility coefficient of 11 or more, but in this case, the hydrogen bond strength can be classified into three levels (weak, medium, strong).
Among those evaluated, weak and medium grades are preferred. In addition, the amount of solvent used is sufficient to dissolve the copolymer to be produced, and usually all monomers are
The amount is at least 50 parts by weight or more, preferably 100 to 500 parts by weight, per 100 parts by weight. The conditions for the copolymerization reaction carried out using the above-mentioned raw materials, catalysts and solvents are not particularly limited, and may be appropriately determined in consideration of the type of raw materials used, the amount blended, the type of solvent, etc. It is usually carried out at a temperature of 30 to 200°C, preferably 45 to 150°C, and a pressure ranging from normal pressure to 30 kg/cm ² G, preferably 0 to 10 kg/cm ² G for 0.5 to 20 hours, preferably 1 to 10 hours. The olefin-maleic anhydride copolymer thus obtained is dissolved in a solvent. Therefore, the obtained copolymer solution can be used as it is, or after the polymerization solvent is partially removed, for specific uses such as adhesives, paint binders, inorganic binders, dispersants, emulsion polymerization stabilizers, metal repair agents, etc. Coating agents for thermal recording paper, fluorescent coating materials, mold materials, water-soluble cores,
It can be effectively used as a liquid crystal display element, an alignment control film, a scale inhibitor, a metal corrosion preventive material, a glaze material, an alkaline battery material, a binder for waste tire powder rubber, a calcium carbonate treatment agent, etc. Furthermore, by adding an alkaline substance such as ammonia, sodium hydroxide, urea, formamide, etc. to this solution and heating it to form an alkaline aqueous solution, it becomes extremely useful as an adhesive or the like. As described above, according to the method of the present invention, since the olefin-maleic anhydride copolymer is obtained in a solution state, the copolymer does not adhere to the inside of the reactor, and productivity is good. be. Therefore, the present invention is extremely useful as a method for producing adhesives, paints, binders, etc. by appropriately selecting raw materials. Next, the present invention will be explained in detail with reference to Examples. Example 1 Acetonitrile 460ml, maleic anhydride 60g,
Put 0.8g of benzoyl peroxide into an autoclave, then cool it down sufficiently, degas the inside of the autoclave, and collect the return obtained from the naphtha cracked gas.
BB (composition: isobutene 44.5%, 1-butene 25.0
%, 2-butene 17.5%, n-butane 9.4%, isobutane 2.5%, others 1.1%). Next, the mixture was stirred at a rotational speed of 400 rpm, the temperature inside the autoclave was maintained at 110°C, and polymerization was carried out for 2 hours. After the reaction was completed, the polymerization reaction solution was treated with an evaporator at 90° C. and 2 mmHg for 3 hours to remove the solvent, yielding 88 g of a copolymer. Conditions, results etc. first
Shown in the table. The same procedure as above except that a portion of the solvent was removed yielded a copolymer solution containing 88 g of copolymer and 50 g of solvent. This product was useful as an adhesive for polypropylene sheets. Example 2 42 g of a copolymer was obtained in the same manner as in Example 1 except that dimethyl sulfoxide was used as the solvent. Comparative Examples 1 and 2 A copolymer was obtained in the same manner as in Example 1 except that the solvent shown in Table 1 was used. The results are shown in Table 1. 【table】

Claims (1)

[Claims] 1. An olefin-maleic anhydride characterized in that an organic solvent having a solubility coefficient of 11 or more is used as a polymerization solvent in producing an olefin-maleic anhydride copolymer by radical copolymerization of an olefin and maleic anhydride. Method for producing acid copolymer.