DE1124695B - Process for the production of joint polymers based on acrylic acid and methacrylic acid - Google Patents

Description

There are acrylic anhydride and methacrylic anhydride on the one hand and polymers on the other each of these anhydrides are known.

On the other hand, mixed polymers of both anhydrides are not known to date.

The invention relates to a process for the production of joint polymers based on acrylic acid and methacrylic acid. It is characterized by the fact that so far this has also been done mixed monomeric anhydride of the two which are not known but which can be prepared in a manner known per se Acids polymerized to give poly (acrylic methacrylic anhydride) and, if appropriate, then the polymeric anhydride hydrolyzed to poly (acrylic methacrylic acid).

The monomeric mixed anhydride of acrylic acid and methacrylic acid has the formula I:

CH.

CH ₃

CH ₂

of joint polymers

based on acrylic acid and methacrylic acid

Applicant:

Rohm & Haas Company,
Philadelphia, Pa. (V. St. A.)

Representative: Dr.-Ing. Dr. jur. H. Mediger, patent attorney, Munich 9, Aggensteinstr. 13th

Claimed priority:
V. St. v. America 9 October 1959 (No. 845 323)

Jesse Chia Hsi Hwa, Levittown, Pa. (V. St. A.),
has been named as the inventor

O'

This mixed anhydride is produced by combining a halide of one acid with an alkali salt the other acid converts, for example in benzene solution in the presence of an inhibitor. Man so brings z. B. methacryloyl chloride with sodium or potassium acrylate, or potassium or sodium methacrylate with acrylyl chloride for reaction. Of course, other acid halides than the Suitable for chlorides.

Methylenanthrone or another known inhibitor, for example, can be used as the inhibitor.

The monomeric mixed anhydride of acrylic and methacrylic acid obtained in this way is liquid and is easy to polymerize in the absence or presence of a solvent. One works with a solvent, it can either be a diluent, which is the one that forms Polymers dissolves, e.g. B. dimethylformamide, dimethyl sulfoxide, etc., or it can be a diluent be, which precipitates the polymer being formed, e.g. B. benzene, acetone, dioxane, etc. In the latter case the precipitated polymer is filtered off, washed with benzene or the like and dried to a white powder. In the first case, a viscous solution of the polymer is obtained, which is used in this form and is precipitated by the addition of a nonsolvent such as acetone. But you can also do that Evaporate the viscous solution to dryness in order to obtain the polymer.

The polymerization can be carried out at temperatures between room temperature and the boiling point of the liquid, but temperatures from 50 to 100 ^° C. are generally preferred. The polymerization can be initiated or accelerated in a known manner by means of heat, UV radiation or catalysts which form free radicals. Typical suitable catalysts are ","'- bis-azoisobutyronitrile, methylazoisobutyrate, benzoyl peroxide, acetyl peroxide, lauroyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, tert-butyl perbenzoate, stearoyl peroxide, ascaridol, and cymol hydroperoxide. The catalysts are used in amounts of from 0.01 to 5%, calculated on the weight of the monomers

The poly-mixed anhydride produced in this way corresponds to constitutional formula II:

CH

where X is an integer greater than 1. For the practically more valuable polymers, X has a value of 100 to 100,000 or more.

209 517/439

These mixed poly anhydrides can easily be converted into copolymers of the two acids by hydrolysis by allowing water and heat to act on the mixed poly anhydrides. In this way, mixed polymers of acrylic and methacrylic acid in a ratio of 1: 1 are obtained, which are particularly interesting and correspond to structural formula III, where X in each case has the same value as in the poly-mixed anhydride from which it was assumed.

CH ₃ H

IO

- CHe - C - CH ₂

COOH

COOH χ

III

These copolymers of acrylic and methacrylic acid are characterized by a unique arrangement of the Excellent acid units in the molecule. The arrangement is different than if you follow the usual ao Methods Acrylic acid and methacrylic acid copolymerized in a molar ratio of 1: 1. In this case Namely, even with catalysis by free radicals, a mixed polymer with an arbitrary one is best obtained and irregular distribution of acrylic acid residues (A) and methacrylic acid residues (M), for example in the sense of the following scheme:

- MMAMAAAAMMAMMMAA -

If one goes against it in the sense of the present invention from the monomeric mixed anhydride of the two acids, a cyclopolymer is formed from structural units MA, which correspond to the formula IV and arranged according to one of the three schemes could be:

(a) - MAMAMAMAMA -

(b) - MAÄMMAÄMMA—

(c) - MAÄMÄMMAÄM -

CH ₃

-CH ₂ -C

H
C -

IV

40

45

If such a poly-mixed anhydride is hydrolyzed according to the invention, a mixed polymer is obtained of the two acids, the building blocks of which can be arranged according to one of the following schemes can:

(a ') - MAMAMAMAMA -
(b ') - MAAMMAAMMA -
(c ') - MAAMAMMAAM -

55

It can be seen that in all three cases the building blocks M and A either alternate in pairs or also Arbitrarily follow one another, but never more than two identical building blocks follow one another.

Thanks to this particular structural arrangement of the building blocks are those according to the present invention The copolymers produced by the two acids are superior to the copolymers of the same acids, obtained by the previous methods directly by polymerizing the two acids will.

The products of the process of the invention have interesting properties and utility.

Poly (acrylic methacrylic anhydride) is, in a similar way to polystyrene and poly (methyl methacrylate), a thermoplastic material and as such can be used, worked and processed, whereby it shows some unique and superior properties. The poly-mixed anhydrides can be molded into webs or shaped objects at elevated temperatures using conventional injection molding methods. The sheets are visually extremely clear and also harder and more heat-resistant than polystyrene. While the latter softens at 130 to 140 ⁰ C to flow, the poly mixed anhydrides of the invention, nor their shape and retain clarity. These are therefore particularly suitable, among other things, for the manufacture of nose pulpits for aircraft. Because of their highly chemically polar character, the poly-mixed anhydrides of the invention are resistant to common commercial organic solvents such as kerosene, benzene, cleaning fluids, acetone, paint thinners, and also to common laboratory solvents such as nitrobenzene, dioxane, ether, chloroform, etc. As a result Shaped objects made from these polymers are also more resistant to such solvents than corresponding objects made from known plastics.

Another advantage of the poly mixed anhydrides is that they can be dissolved in strongly polar solvents such as dimethylformamide and dimethyl sulfoxide. For example, to obtain a clear viscous solution when 30 parts of powdery poly-mixed anhydride and 70 parts of dimethyl sulfoxide was heated with stirring for 30 minutes at 120 ⁰ C. The viscosity of the Gardner-Holdt solution at 25 ° C. is V. It can be applied to a large number of metal objects by brushing on, dipping or the like, and can be dried by heating. This gives clear, hard plastic coatings which are distinguished by the solvent resistance indicated above.

A particular advantage of the poly-mixed anhydrides of the invention is their ability to seal against glass surfaces be liable. A laminate of a layer of mixed poly anhydride between two glass plates has a strong structural strength without loss of optical clarity. The poly mixed anhydrides are therefore suitable very good as a binder in certain glassware, e.g. B. TV tubes.

The mixed polyanhydrides of the invention, as well as the mixed poly acids, have other valuable ones as well Properties and applications based on them, For example, the acid is valuable as a warp size for polyamide yarns.

The following examples illustrate embodiments according to the invention:

example 1

108 parts of dry sodium methacrylate, 0.6 part of methylenanthrone and 400 parts of benzene are mixed in a reaction vessel equipped with a mechanical stirrer, reflux condenser and dropping funnel, and 115 parts of acrylyl chloride are added dropwise over the course of 40 minutes with constant stirring. The temperature of the mixture rises from 25 to 55 ⁰ C. The mixture was then heated three hours

the reflux, left to stand overnight at room temperature, then drives off the benzene by distillation, heats the remaining amount further under vacuum and receives 129 parts of acrylic methacrylic anhydride as a colorless liquid which boils at 64 ° C / 4 mm Hg and its refractive index n'S has the value 1.4516. Yield 92.3%.

Analysis: 60.4% C, 5.57% H (theory for C ₇ H ₈ O ₃ : 60.0% C, 5.71% H).

IO

The mixed anhydride is prepared in the same way by reacting sodium acrylate with methacrylyl chloride here.

The production of the monomeric anhydrides is not part of the subject matter of the invention.

A mixture of 20 parts of the acrylic methacrylic anhydride and 160 parts of benzene is boiled for 18 hours and 0.1 part of azobisisobutyronitrile, the precipitate is filtered off, washed three times with 100 parts of benzene each time, the washed polymer dries in the oven and receives 19.8 parts of poly-Cacryl-methacrylic anhydride). yield 99%.

In the same way, a mixture of 100 parts of acrylic methacrylic anhydride is heated for 12 hours, 600 parts of acetone and 2 parts of benzoyl peroxide to 60 ° C., the precipitate is filtered off, washed, dried and receives 72 parts of poly (acrylic methacrylic anhydride).

The polymers obtained in both cases are in common organic solvents, such as benzene, Alcohol, acetone, ether, octane, acetonitrile, butylcellosolve are insoluble, but dissolve in dimethylformamide and dimethyl sulfoxide.

Example 2

A mixture of 10 parts of acrylic methacrylic anhydride, 40 parts of toluene and a trace of benzoin in an ampoule is made using a bath of liquid Frozen nitrogen. The ampoule is melted under vacuum and irradiated at -50 ° C. for 7 hours by means of a UV light source (»Sylvania« black light tube), the reaction mixture is removed from the Ampoule, mixed it with an excess of hexane, filtered off the precipitated polymer and dry it in the oven. 4.2 parts of poly (acrylic methacrylic anhydride) are obtained.

Example 3

Acrylic methacrylic anhydride is polymerized in a glass mold in the presence of 0.02% benzoyl peroxide within 40 hours at a temperature of 65 to HO ⁰ C and obtained as a clear, hard polymer poly-acrylic acid methacrylic anhydride, which adheres well to glass and when heated 100 to HO ⁰ C not softened.

A laminate made in this way from a layer of polymer between two glass plates has good mechanical strength, thermal stability and clarity.

Example 4

A mixture of 100 parts of acrylic methacrylic anhydride, 200 parts, is heated for 10 hours Dimethyl sulfoxide and 1 part α, Λ'-bis-azoisobutyronitrile to 100 ° C. Another part of the catalyst is then added and the mixture is heated for a further five hours. the The resulting viscous solution is cooled to room temperature and stirred with 1500 parts of isopropanol the precipitated substance was washed with fresh isopropanol and then dried.

45 parts of poly (acrylic methacrylic anhydride) are obtained.

Example 5

A mixture of parts of poly (acrylic methacrylic anhydride) and is boiled for 2 hours Parts of water, the solution then treated with a commercially available adsorbent, dried by freezing out and receives 7.4 parts of poly (acrylic methacrylic acid). The polymer is soluble in water and can be neutralized with alkali solutions.

Example 6

A mixture of 10 parts of poly (acrylic methacrylic anhydride) is stirred. and an equivalent amount of 1 η sodium hydroxide solution at room temperature overnight and the sodium salt is obtained in quantitative yield of poly (acrylic methacrylic acid). The free polyacid can be produced by ion exchange and evaporation to be isolated.

Example 7

Powdered poly (acrylic methacrylic anhydride) is dissolved in an equivalent within a few minutes Amount of aqueous alkali and a clear solution of an alkali salt of poly (acrylic methacrylic acid) is obtained.

Claims (6)

PATENT CLAIMS: 1. A process for the preparation of joint polymers based on acrylic acid and methacrylic acid, characterized in that first the mixed monomeric anhydride of the two acids prepared in a conventional manner is polymerized to give the poly (acrylic-methacrylic anhydride) and then optionally the poly-mixed anhydride hydrolyzed to poly (acrylic methacrylic acid). 2. The method according to claim 1, characterized in that the monomeric mixed acid anhydride in the presence of a polymerization accelerator at a temperature of room temperature polymerized to the boiling point of the liquid, preferably between 50 and 100 ° C. 3. The method according to claim 1, characterized in that the polymerization in the presence a diluent is carried out, which dissolves the resulting polymer. 4. The method according to claim 1, characterized in that the polymerization in the presence a diluent is carried out, which precipitates the resulting polymer. 5. The method according to claim 2, characterized in that the polymerization is carried out in the presence an excess organic solvent for the monomeric mixed acid anhydride executes, the precipitated reaction product is filtered off, the precipitation in a further excess Solvent washes and dries. 6. The method according to claim 1 to 5, characterized in that the poly (acrylic methacrylic anhydride) obtained converted into poly (acrylic methacrylic acid) by heating in water. Publications considered: Ber. d. German Chem. Ges., 57, p. 429. 1 209 517/439 2.