DE936297C - Polymerisation process - Google Patents

Description

(WiGBL p. 175)

ISSUED DECEMBER 7, 1955

M 6586 IVc 13g c

The invention relates to a process for the polymerization of a vinyl compound of the formula R - CH = CH ₂ , in which R is a phenyl or a substituted phenyl radical, together with an acidic sec-alkyl ester of an ethylene-α · ß-dicarboxylic acid.

Example ι

62 parts by weight of maleic anhydride, 33 parts by weight of sec-butyl alcohol, and 5 parts by weight of methyl alcohol was heated to 60 to 70 ⁰ until the titration of a sample, the constancy of acid value revealed even at further heating. 48 parts by weight of styrene and 0.3 part by weight of benzene peroxide as a catalyst were added to 51.7 parts by weight of the mixture thus obtained. For the polymerization, the temperature was initially held during the period of intense heat development at 60 ° to 70 ° and let them thereafter to about 125 ⁰ to the complete course of the reaction increase. The product thus obtained is a hard, colorless resin, soluble in alkalis but insoluble in water. The alkaline solutions are very useful as sizes and for paper coating agents. The ammoniacal solution loses enough ammonia on drying to give a film that is insoluble in water but still soluble in alkali or ammonia. The films obtainable from such solutions can be increased water resistance by drying at higher temperatures or by adding substances which react with the carboxyl groups of the polymer. These substances include active pigments such as calcium carbonate, polyvalent amines and alcohols such as polyethylene amines, polyglycols, polyvinyl alcohol and melamine-formaldehyde resins. The toughness and flexibility of the films can be improved by adding compatible plasticizers. For this purpose

the soaps of unsaturated acids are particularly suitable, like oleic and ricinoleic acid. This not only makes the film essentially brittle eliminated, but also reduced the viscosity of the polymer solution, so that at a certain Viscosity a higher solids content of the solution is made possible. A suitable ratio is approx 30 parts by weight of soap to 70 parts by weight of polymer.

This type of polymer, like styrene-maleic anhydride, an alkali-soluble material with important assets that make it particularly valuable to some Purposes. Its advantages include: the increased tendency of ammoniacal solutions to form water-insoluble films and improved compatibility with plasticizers, which makes it pliable To obtain coatings from solutions with a high solids content.

The polymer contains a mixed polymer of ao styrene and maleic acid mono-sec-butyl ester with an ester ratio of 72 mole percent acidic secondary butyl ester, 24 mole percent acidic methyl ester, remainder anhydride with maleic acid; such mixed polymers give alkaline solutions of lower viscosity than polymers of neutral sec-butyl ester and styrene.

Increase in the styrene content or increase in the proportion of maleic acid associated with the secondary butyl alcohol leads to the emergence of higher viscosity for the alkaline solutions of polymers with similar Molecular weights. Such an increased viscosity is useful or useful for some purposes even desirable, generally inexpedient if the solutions are in glues or based on the alkaline solutions prepared coatings are to be used.

Example 2

46 parts by weight of methyl isobutyl carbinol, 51.9 parts by weight of maleic anhydride and 2.3 parts by weight of methyl alcohol were in a vessel as long as, for. B. 2 hours, ^{heated to 80 to 90 0} until the titration showed that the acid value remained constant even with further heating. To 57.25 parts by weight of the product thus obtained were added 42.5 parts by weight of styrene, and 0.25 parts by weight of benzoyl peroxide, and polymerization during the period of intense heat development at 60 to 70 ⁰ and subsequently allowing the climbing _ temperature to 125 ⁰ during the complete completion of the reaction still required time carried out.

The product thus obtained is in common nitrocellulose lacquer solvents, such as ethyl acetate, Butyl acetate and the like, in alcohols such as ethyl alcohol, butyl alcohol, etc., in alcohol-hydrocarbon mixtures, such as butyl alcohol-xylene, butyl alcohol-petroleum fraction and the like, soluble.

For the production of highly stretchable coatings, e.g. B. for cloth, leather and paper, the product can be modified are made by compatible plasticizers, e.g. B. diglycol ricinoleate, glyceryl monooleate, dibutyl sebacate, aqueous phthalic acid or Glykohnonoäthyläther. It is compatible with other film-forming substances, e.g. nitrocellulose or polyvinyl butyral, and with certain alcohol-soluble resins, e.g. B. Manilacopal. With nitrocellulose, it gives it special flexibility and adhesive strength. Reacts with polyvinyl butyral resin the polymer, when heated, forms an insoluble one which cannot be softened by heating Films. It gives the resins special toughness. ■

The molecular weight of the new products and the viscosity of their solutions can be determined by appropriate Choice of the reaction temperature, the catalyst and the amount of modifier can be varied. One particularly practical method, polymers with low To get molecular weight is the use of a small amount of nitrostyrene in polymerizing, along with a slightly larger amount of catalyst.

The acidic sec-alkyl esters of the invention, with the vinyl compounds of the invention, give copolymers having excellent heat resistance. The sec-alkyl esters of ethylene-α · / 3-dicarboxylic acids are new chemical compounds. They are obtainable by heating the anhydride has reacted with the appropriate acid to the secondary alcohol, preferably using a 10 to 20 ° / _O igenÜberschusses of anhydride over the equivalent amount until virtually all of the alcohol. In general, excess acid does not need to be separated from the cold crude ester by crystallization, but the crude product can be used directly for copolymerization.

Further suitable compounds of the formula R - CH = CH ₂ are, for. B. halogen-substituted styrene, methyl styrene and the like. Acid sec-alkyl esters of ethylene-α ^ -dicarboxylic acids include the acidic esters of maleic acid, fumaric acid, citraconic acid, phenyl maleic acid, benzyl maleic acid, ethyl maleic acid, etc., preferably with lower alkyl, such as isopropyl and sec-octyl.

The products can e.g. B. can be used as follows:

A varnish based on polyvinyl butyral resin made using a mixed polymer of acid methyl ester and styrene, consisted of (in parts by weight)

Polyvinyl butyral resin 20

Styrene copolymer 10

Butyl ricinoleate 15

Diethylene glycol monooleate 10

Ethyl alcohol 25

Petroleum fraction (60 to 100 °) 20

When the cloth is handled, it gives a clear, waterproof, flexible film. To achieve more colored Coatings can be pigmented.

A varnish made of (in parts by weight)

Half-second nitrocellulose 10

Copolymer of styrene and

acidic maleic acid secondary butyl ester 10

Diglycol ethyl ether phthalate 10

Butyl acetate 20

Glycol ethyl ether 20

Ethyl alcohol 10

Toluene 20

has excellent color, flexibility and adhesion to metallic surfaces. By varying the solvent combination, e.g. B. by omitting the glycol ether, a matt when drying instead of clear film can be obtained. Excellent results are also obtained when in the above Composition the mixed polymer of styrene with acid maleic acid sec-butyl ester by that is replaced with acid methylamyl ester. ίο A resin varnish made from (in parts by weight)

Manila copal 20

Copolymer of styrene and
maleic acid secondary butyl ester 5

Denat. Alcohol 75

can be used like shellac solution.
A composition was made from (in parts by weight)

low viscosity mixed polymer
of styrene and acidic maleic acid secondary butyl ester 20

Oleic acid 6

Ammonia solution 74

manufactured.

The alkalinity of the solution is adjusted by the strength of the ammonia solution, so that the composition reacts only slightly alkaline, e.g. B. a p _H of

9 to 10 has. If it is highly pigmented with clay or ground limestone, the result is the composition a smooth, flexible coating that is an excellent printing surface on art paper.

Claims (3)

PATENT CLAIMS: 1. Polymerization process, characterized in that a vinyl compound of the formula R - CH = CH ₂ , for example styrene, in which R is a phenyl or a substituted phenyl radical, together with an acidic sec.-alkyl 4a ester of an ethylene-a · / S-dicarboxylic acid is polymerized. 2. The method according to claim 1, characterized in that that a secondary acidic alkyl ester with lower alkyl (sec-butyl, Methyl isobutyl carbinol ester), e.g. B. maleic acid applies. 3. Process according to Claims 1 and 2, characterized in that the polymerization is carried out in the presence of acidic methyl maleate. Referred publications:
U.S. Patent No. 2,047,398. 1 509590 12.