NL7906502A - Terpolymer of ethylene!, vinyl! acetate - and peroxy:alkyl acrylate! as binder for paint, as plasticiser, and backbone in graft copolymers - Google Patents

Abstract

Copolymer of formula (I) where R' is an n-alkyl gp., e.g. CH3, C2H5, C3H7, C4H9 or C5H11; R" has formula (II) or -O-C(CH3)3; x is 24.0-89.9 mols.%; y is 10.0-75.0 mols.%; and z is 0.1-1.0 mols.%, is prepd. by reacting vinyl acetate, ethylene and a peroxy-alkyl acrylate, using a radical initiator, in an organic solvent or an aq. soln. of surfactants and/or polymeric protective colloids, at 20-70 deg.C and 15-100 kgf/square cm. Copolymers are binders for water-resistant emulsion paints, and water- and weather-resistant coatings. They can also be used for prodn. of low-shrink articles, and as plasticisers for, e.g. polymethyl methacrylate and PVC. Vinyl monomers can be grafted onto the copolymers. The copolymers have good mechanical strength. The degree of swelling in an atmos. satd. with water vapour depends on the content of peroxy monomer, and is 0.9-8.6%. The tensile strength is 35-194 kgf/square cm, and 51-245 kgf/square cm after heat-treatment at 110 deg.C. The elongation is 660-1050%, and 540-810% after heat-treatment at 110 deg.C.

Description

* I

-1-20901 / Uk / iv

Applicants: Vram Torgoraovich Shirinian, Suren Sarkisovich Mnatsakanov,

Valery Nikolaevich Pavljuchenko, Mark Eduardovich Rozenberg, Valery Viktorovich Gromov, Sergei Stepanovich Ivanchev, in Leningrad, U.S.S.R.

Short designation: Process for preparing copolymers of vinyl acetate, ethylene and peroxyalkyl acrylate.

The invention relates to a process for preparing copolymers of vinyl acetate, ethylene and peroxyalkyl acrylate.

More particularly, the invention relates to the preparation of new chemical compounds, in particular to the preparation of new copolymers. The novel compounds of the invention are useful as a binder in the preparation of a water-resistant paint emulsion and water-resistant and weather-resistant coating, as well as for the preparation of materials which can be used for the production of articles with low shrinkage or as. plasticizer for polymethyl methacrylate, polyvinyl chloride and other polymers.

The process according to the invention is characterized in that the copolymer corresponding to formula 1 stated on the formula sheet, wherein R 1 is a normal alkyl such as -CH 2, -C 2 Hg »" ^ 3 ^ 7 "" C4 H 9 or R 2 represents a group of formula 2 or -O-CiCH2) ^ where x = 24.0-89.9 mol%, y = 10.0-75.0 mol% and z = 0.1-1.0 mol%, by reacting vinyl acetate, ethylene 20 and peroxyalkyl acrylate under the action of a radical initiator in an organic solvent or an aqueous solution of surfactants and / or polymeric protective colloids at a temperature of 20-70 ° C and a pressure of 15-100 kg f / cm 2, followed by separation of the desired end product.

The new copolymers contain structure-reactive peroxy-type functional groups that can be used as a copolymer for cross-linking or grafting various vinyl monomers thereon.

Depending on the composition of the copolymer and the process for its preparation, copolymers can be obtained with a molecular weight of 20,000-125,000 and a glass transition temperature of 16-37 ° C. The water resistance of the copolymers, determined by the swelling in an atmosphere saturated with water vapor, is highly dependent on the amount of peroxymonomer units in the copolymer structure and ranges from 0.9 to 8.6%, based on the initial copolymer mass.

The mechanical properties of the obtained film from the proposed 790 65 02 is * -2-20901 / Vk / iv copolymers depend on the composition of the copolymer. An ultimate tensile strength is 35-194 kgf / cm with an elongation ranging from 660 to 1050%.

With a heat treatment at a temperature of 110 ° C, the ultimate 2 tensile strength is increased to 51-245 kgf / cm, with the elongation decrease from 5 to 540-810%.

The composition of the copolymer was calculated using the data on the active oxygen content in the copolymers as obtained by an iodometric analysis and the measurements in the IR spectrum of the absorption band intensities within the range of 1433 cm 10 (deformation vibrations of the -CH? groups of the vinyl acetate units) and the 2925 cm area (the valence vibrations of the -CHg groups of the ethylene units).

10% solutions of the copolymers in carbon tetrachloride were used to obtain the IR spectra.

The light diffusion method was used to determine the molecular weight of the copolymers. The light scattering measurements were made using a copolymer solution in benzene at a temperature of 30 ° C.

The glass transition temperature of the copolymers was determined based on the modulus of elasticity which measurements were taken at different temperatures.

To determine the water resistance of the copolymers, 0.5 mm thick films were dried in a thermostat at a temperature of 60 ° C for 3 hours and then held in a thermostat at a relative humidity of 100% at 20 ° C for 24 hours.

The new copolymers of vinyl acetate, ethylene and peroxyalkyl acrylate have been prepared by copolymerizing the monomers. The peroxy monomers used were 1 (d-alkyl acrylate) -1-tert-butyl peroxyethane or tert-butyl peroxy-o-alkyl acrylates of general formula 3, indicated on the formula sheet, where a normal alkyl group is -CH 3, -C ^, -C ^, -C ^ H ^ or -CH .., and R ~ is a group of formula 2, indicated on the formula sheet, or O 11 2 -0-C (CH 3) 3.

The copolymerization can be carried out in an emulsion, suspension or in a solvent system in the presence of a radical type initiator.

The initiators used for the emulsion copolymerization 7906502 / 3-20901 / Vk / iv are water-soluble types such as potassium persulfate or redox systems based thereon such as potassium persulfate sodium metabisulfate.

The initiators used for the slurry or solution copolymerization are oil-soluble types such as azoisobutyronitrile.

The emulsifiers used in the emulsion copolymerization are ionic and nonionic emulsifiers and polymeric protective colloids such as sodium lauryl sulfate, oxyethylated phenols, hydroxyethyl cellulose, or polyvinyl alcohol. Polymeric protective colloids and mineral stabilizers such as barium sulfate are used to stabilize the large particle emulsions in a suspension polymerization.

In the emulsion and slurry copolymerization operation, sodium bicarbonate or formic acid is used as an alkalizing agent or as an acidity adjusting agent for the aqueous phase.

Tert-butyl alcohol is used as the solvent for the solution copolymerization. The copolymerization is carried out in an autoclave reactor of 5 or 27 liters capacity and equipped with an anchor-type jacket and stirrer.

In the emulsion copolymerization, distilled water is dissolved with the erosion stabilizers and initiator and the first agent is fed to the autoclave, the feed of vinyl acetate and peroxyalkyl acrylate being carried out in amounts of 5 to 50% of the total mass of the monomers.

The first amount of the vinyl acetate and peroxyalkyl acrylate mixture fed to the autoclave is stirred at a rate of 100 to 250 revolutions per minute for 30 minutes and rinsed with ethylene to remove the oxygen. Then the reaction mixture is saturated with ethylene under pressure and the temperature is raised to the level required to allow the copolymerization to take place. Two hours later, a second portion of the vinyl acetate and peroxyalkyl acrylate mixture is added. After this, each subsequent portion is supplied after 30 minutes from the previous addition. After the last amount of starting material supplied, the copolymerization is continued for an additional 1 to 2 hours.

Additional amounts of initiator and emulsifying agent can be added in the form of an aqueous solution during the copolymerization to achieve a higher speed and an increased stability of the dispersion formed in the process.

790 65 02 *. i -4- 20901 / Vk / iv

The emulsion copolymerization is carried out at temperatures between 20 and 60 ° C and at a pressure between 15 and 100 kgf / cm 2. The product of the emulsion copolymerization is a fine polymeric dispersion in the form of a latex which can be used directly for the production of films or coatings. In the slurry copolyinerization, distilled water with the polymer-protective colloid and the mineral stabilizer is added to the autoclave and the vinyl acetate and peroxyalkyl acrylate are added as a mixture together with the copolymerization initiator dissolved herein with stirring. The reaction mixture is then stirred at a speed of 100 to 250 revolutions per minute for 30 minutes and purged with ethylene to remove the oxygen therefrom. Then the reaction mixture is prepared with ethylene to obtain a pressure of 30 kgf / cm, after which the temperature is raised to 60 ° C and the pressure is brought to 2 70 kgf / cm. The copolymerization can then be continued under these conditions for 2 hours. Then the temperature is raised to 70 ° C and the copolymerization is continued for another 4 hours. After cooling the reaction mixture to a temperature of 25 ° C, the copolymerization product in the form of granules is discharged on a filter device and then washed, dehydrated and dried at a temperature of 20 ° C.

Tert-butyl alcohol is used as the solvent for the solution copolymerization.

The initiator and the first part of the amount of vinyl acetate and peroxyalkyl acrylate mixture dissolved in tert-butyl alcohol are added to the autoclave. After saturating the reaction mixture with ethylene to a pressure of 40 kgf / cnf, the temperature is raised to 50 ° C, the pressure is built up to 2 to 70 kgf / cm and the copolymerization is continued for 40 minutes. Then vinyl acetate and peroxyalkyl acrylate mixture are dissolved in tert-butyl alcohol and fed in measured amounts, after which the temperature is raised to 60 ° C. Each subsequent portion of the monomer mixture is fed in 30 to 60 minutes after the addition of the previous amount. After cooling the reaction mixture to 30 ° C, the copolymerization product is discharged in the form of a solution of the copolymer in tert-butyl alcohol.

For the production of the film and a coating, the copolymers according to the invention are used as polymer dispersion and solution in tert-790 65 02 / ¼ -5-20901 / Vk / iv butyl alcohol. The copolymer is separated from the solution and dispersion by precipitation in a 5% aqueous sodium chloride solution, followed by washing with water and drying at 20 ° C. The copolymer samples used to determine the molecular mass composition are further purified by dissolving them in benzene (5% solutions are prepared), then precipitated in water, the solution to water ratio being as 1:10. The copolymer films used to determine the mechanical strength are prepared directly from the polymeric dispersions or 5% solutions of the copolymers in benzene. For higher mechanical strength, the copolymers are cross-linked to the peroxy groups by heat treatment at a temperature of 110 ° C.

The invention is further illustrated by the following examples.

Example I

A 5 1 jacketed autoclave and an armature stirrer were charged with 750 g of water, 55 g of polyvinyl alcohol with an acetate group content of 1.2% by weight, 3 g of potassium persulfate, 1.5 g of sodium bicarbonate and a mixture of 500 g vinyl acetate and 1.5 g 1- (o-methyl-acrylate-1-tert-butylperoxyethane. The contents of the autoclave were stirred at a speed of 250 rpm for 30 minutes and then rinsed with ethylene. the reaction mass saturated with ethylene to a pressure of 15 kgf / cm 2 at a temperature of 20 ° C. Then the temperature was raised to 60 ° C and the copolymerization was continued for 2 hours, then five parts of an emulsion was added at intervals 30 minutes each portion contained 150 g of water, 200 g of vinyl acetate, 5 g of 1- (οί, -raethyl-acrylate) 1-tert-butylperoxyethane and 5 g of polyvinyl alcohol After the fifth portion was put into the reactor, 50 g of a 4% potassium persulfate solution and the copolymerization was continued for an additional 2 hours.

The reaction mixture was then cooled to 25 ° C and the product dispersed in a dispersion form. The copolymer thus obtained had the following properties: composition (mol%): 89.9% vinyl acetate, 10.0% ethylene, 0.1% 1 - (οί-rae thy lacry laa t) -1-tert-butylperoxyethane, 35 molecular weight 120,000 790 65 02 v * -½ · -6- 20901 / Vk / iv glass transition temperature 32 ° C, degree of swelling 8.6%, elongation 680%, and after heat treatment at 110 ° C 620%, p 5 ultimate tensile strength 35 kgf / cm,

and after heat treatment at 110 ° C 51 kgf / cm 2 Example II

The copolymerization was carried out in the same manner as in Example X using 1- (o -propyl-acrylate) -1-tert-butylperoxy-10-ethane having a total weight of 60 g, instead of 1- (methyl-acrylate) -1-tert-butylperoxyethane as peroxymonomer and 15 g of a mixture with 7.5 g of hydroxyethyl cellulose and 7.5 g of ethylene oxide-propylene oxide block copolymer which was used as an emulsifier.

The copolymer thus obtained had the following properties: composition (mol%): 86.2% vinyl acetate, 13.6% ethylene and 0.2% 1 - ([- propyl acrylate) -1-tert-butylperoxyethane, molecular weight 110,000, glass transition temperature 34 ° C, 20 swelling 3.4%, elongation 700% and after heat treatment at 110 ° C 640%, 2 ultimate tensile strength 44 kgf / cm and after heat treatment at 110 ° C 76 kgf / cm2.

Example III

A 5 L autoclave was charged with 1500 g of water, 4 g of sodium lauryl sulfate, 2 g of sodium bicarbonate, 5 g of potassium persulfate and a mixture consisting of 150 g of vinyl acetate and 32 g of 1- (n-amyl acrylate) -1-t-butylperoxyethane .

2

The reaction mixture was saturated with ethylene to a pressure of 20 kgf / cm, the temperature was adjusted to a value of 20 ° C, the pressure to 50 kgf / cm, and after addition of 40 g of 3% sodium ametabisulfate solution, the copolymerization was continued for 2 hours. After the temperature was raised to 25 ° C and vinyl acetate and 1- (1-amyl acrylate) -1-tert-butylperoxyethane mixture was fed at 30 minute intervals, 10 g of 3% sodium metabisulfate-35 solution was added to each portion of the monomer mixture. Each portion of 790 65 02 * 7-7 20901 / Vk / iv the monomer mixture contained 100 g of vinyl acetate and 8 g of 1- (ct-amyl acrylate) -1-tert-butylperoxyethane. After adding the sixth portion of the reactants, the copolymerization was continued for an additional 1 hour and the dispersion cooled to 25 ° C and discarded.

The polymer thus obtained has the following properties: composition (mol%): 61.6% vinyl acetate, 37.9% ethylene, 0.5% 1 - (ot-amyl acrylate) -1-tert-butylperoxyethane, molecular weight 90,600, 10 glass transition temperature 36 ° C, swelling 2.8%, elongation 980% and after a heat treatment at 110 ° C 720 ° C, 2 ultimate tensile strength 96 kgf / cm 15 and after a heat treatment at 110 ° C 135 kgf / cm2.

Example IV

The copolymerization was carried out in the manner as described in Example III with. 1- (a-ethyl acrylate) -1-tert-butylperoxyethane which was used as peroxymonomer instead of 1- (tf-amyl acrylate) -1-tert-butylperoxy-20 ethane. First, a mixture of 500 g of vinyl acetate and 30 g of 1- (ot-ethyl acrylate) -1-tert-butyl peroxyethane was added to the autoclave, and then 970 g of a mixture consisting of 850 g of vinyl acetate and 120 g of 1-icC-thyl acrylate) -1-tert-butyl peroxyethane added in six equal parts at 30 minute intervals. The copolymerization was carried out at a pressure of 100 kgf / cm2.

The copolymer thus obtained has the following properties: composition (mol%): 24.0% vinyl acetate, 75> 0% ethylene, 1.0% 1-ethyl ethyl acrylate) -1-tert-butyl peroxyethane, molecular weight 75,000, glass transition temperature 37 ° C, swelling 1.2%, elongation 1050% and after heat treatment at 110 ° C 180%, 2 ultimate tensile strength 174 kgf / cm and after heat treatment at 110 ° C 245 kgf / cm2.

790 65 02 -8- 20901 / Uk / iv

Example V

The copolymerization was carried out as described in Example I, except that 1- (Od-butyl acrylate) -1-tert-butyl peroxyethane was used as peroxy monomer instead of 1- (ot-methyl acrylate) -1-tert-butyl peroxy-5 ethane . First, 35 g of 1- (butyl acrylate) -1-tert-butyl peroxyethane was fed to the autoclave and the remaining amount was fed in five portions 2 each of 5 g. The copolymerization was carried out at a pressure of 30 kgf / cm.

The polymer thus obtained had the following properties: composition (mol%): 79.5% vinyl acetate, 10 20.5% ethylene, 0.3% 1- (ec-butyl acrylate) -1-tert-butylperoxyethane, molecular weight 95 * 000 , glass transition temperature 30 ° C, swelling 2.2%, 15 'elongation 760% and after heat treatment at 110 ° C 680%, 2 ultimate tensile strength 56 kgf / cm

O.

and after heat treatment at 110 ° C 81 kgf / cm.

Example VI

A 27 L autoclave was charged with 8.5 kg of water, 600 g of 3,5-dinonyl phenyloxydecaethylene oxide, 14 g of sodium bicarbonate, 500 g of 5% potassium persulfate solution and a mixture of 970 g of vinyl acetate and 38 g of tert-butylperoxymetha crylate. The reaction mixture was stirred at a speed of 100 rpm and then rinsed with ethylene and then saturated with ethylene to a pressure of 30 kgf / cm. Then the temperature was adjusted to 20 ° C, 2 the pressure at 50 kgf / cm and 50 g of 10% sodium metabisulfate solution was added. 30 minutes later, a mixture consisting of 970 g of vinyl acetate and 12 g of tert-butyl peroxyethane was fed in ten equal amounts, the portions being added at 30 minute intervals. After the tenth portion was added, 100 g of a 5% solution of potassium persulfate was added to the autoclave, the temperature raised to 30 ° C, and the copolymerization continued for an additional 2 hours before the polymeric dispersion was removed. The copolymer thus obtained had the following properties: composition (mol%): 61.0% vinyl acetate, 38.2% ethylene, 0.8% tert-butylperoxy thacrylate, 790 65 02-9-20901 / Vk / iv molecular weight 90 «600» glass transition temperature 34 ° C, swelling 1.8%, 5 elongation 810% and after heat treatment at 1 · 10 ° 0 730%, 2 ultimate tensile strength 71 kgf / cm and after heat treatment at 110 ° C 92%.

Example VII

A 27 L autoclave was charged with 16 kg of water, 110 g of 10% polyvinyl alcohol solution with 15.5 wt% acetate groups, 10 g of barium sulfate, 4 g of formic acid, a mixture consisting of 5 kg of vinyl acetate and 908 g of tert -butylperoxy-ethyl-acrylate, and 25 g of azobisisobutyronitrile. The reaction mixture was stirred for 15 minutes and then rinsed with ethylene and saturated with ethylene to a pressure of 30 kgf / cm. Then the temperature was raised to 60 ° C, the pressure adjusted to 70 kgf / cm 2 and the copolymerization continued for 2 hours. After the temperature was raised to 70 ° C, copolymerization was continued for an additional 4 hours. The contents of the autoclave were then cooled to 25 ° C and discharged through a filtering device. The product was obtained in the form of granules or beads and was washed, anhydrified and dried at 20 ° C. The copolymer thus obtained had the following properties: composition (mol%): 57.0% vinyl acetate, 42.4% ethylene, 0.6% tert-butyl peroxyethyl ethyl acrylate, molecular weight 70,000, glass transition temperature 28 ° C, swelling 0 , 9%, elongation 960%, 30 after heat treatment at 110 ° C 810%, 2 ultimate tensile strength 125 kgf / cm, o 2 after heat treatment at 110 C 158 kgf / cm.

Example VIII

The copolymerization was carried out as indicated in Example VII, except that 186 g of tert-butyl peroxypropyl acrylate was used as 790 65 02 -10-20901 / Vk / iv peroxymonomer instead of tert-butyl peroxy-ethyl acrylate, and the pressure of 2 kgf / cm was kept constant during the copolymerization.

The copolymer thus obtained has the following properties: composition (mol%): 82.6% vinyl acetate, 16.5% ethylene, 0.9% tert-butylperoxy-d-propyl acrylate, molecular weight 80,000, glass transition temperature 23 ° C, swelling 1 , 1%, 10 elongation 660%, after a heat treatment at 110 ° G 540%, 2 ultimate tensile strength 95 kgf / cm _ rt after a heat treatment at 110 ° C 130 kgf / cm.

Example IX

A 27 L autoclave was charged with 5 kg of vinyl acetate and 312 g of a mixture consisting of 200 g of tert-butyl alcohol, 60 g of azobisisobutyronitrile and 52 g of tert-butyl peroxybutyl acrylate. After saturation of the reaction mixture with ethylene, the pressure was raised to 40 kgf / cm, the temperature was raised to 50 ° C and the pressure was brought to 70 kg / cm and the copolymerization was continued for 40 minutes. After this, 1 kg of vinyl acetate and 130 g of a mixture consisting of 100 g of tert-butyl alcohol and 30 g of tert-butyl-peroxy-butyl acrylate were added to the autoclave and the copolymerization was continued for an additional 1 hour. Then 500 g of vinyl acetate and 20 g of tert-butyl peroxy-c (butyl acrylate) were added to the autoclave. Then monomers were added again in the same amounts 30 minutes later, the temperature was raised to 60 ° C and this temperature was maintained for 40 minutes, after which 1 kg of vinyl acetate and 20 g of tert-butylperoxy-tf-butyl acrylate were added 1 hour after the addition of the stated amounts, 1300 g of tert-butyl alcohol were added and the copolymerization was continued for an additional 30 hours. was obtained, cooled to 30 ° C and removed from the autoclave The copolymer thus obtained had the following properties: composition (mol%): 45.6% vinyl acetate, 54.0% ethylene, 0.4% tert- butyperoxy-ct-butyl acrylate, 790 65 02 -11- 20901 / Vk / iv r molecular weight 20,000, glass transition temperature 18 ° C, swelling 2.9%, elongation 950%, 5 after heat treatment at 110 ° C 800%, 2 ultimate tensile strength 86 kgf / cm,

rt O

after heat treatment at 110 C 110 kgf / cm.

Example X.

The copolymerization was carried out as indicated in Example IX, except that tert-butyl peroxy-amyl acrylate was used as peroxy monomer instead of tert-butyl peroxy-K-butyl acrylate.

The copolymer thus obtained has the following properties: composition (mol%): 46.9% vinyl acetate, 52.8% ethylene, 0.3% tert-butylperoxy-oc-amyl acrylate, molecular weight 23,000, glass transition temperature 16 ° C, swelling 3 , 6%, elongation 1000%, 20 after heat treatment at 110 ° C 850%, 2 ultimate tensile strength 80 kgf / cm,

O.

after heat treatment at 110C 98 kgf / cm.

Example XI (comparative example)

The copolymerization was carried out as indicated in Example 1.25, but without using peroxyalkyl acrylate.

The resulting copolymer had the following properties: composition (mol%): 89.0% vinyl acetate, 11.0% ethylene, molecular weight 125,000, glass transition temperature 22 ° C, swelling 26.5%, elongation 900%, after heat treatment at 110 ° C 880%, 2 ultimate tensile strength 17 kgf / cm,

O.

After a heat treatment at 110 C 20 kgf / cm.

790 65 02 -12- 20901 / Uk / iv

The proposed vinyl acetate, ethylene, and peroxyalkyl acrylate terpolymers of the invention are useful as a binder for preparing waterproof and weather-resistant coatings and compositions used in low shrinkable moldings based on a polyester.

The proposed copolymers can also be used as. plasticizers for polymethyl methacrylate, polyvinyl chloride and other polymers. As plasticizers, they can be added during processing or synthesis.

The copolymers according to the invention can also be used as a basis for the. synthesis of different graft copolymers, thereby providing improved impact strength and weather resistance.

Compared to the conventional bipolymers of vinyl acetate and ethylene, the copolymers of the invention are more water resistant and have better mechanical strength. The properties mentioned above can be further improved during processing of the copolymers at elevated temperatures by effecting cross-linking together with the decomposition of the peroxy groups present in the copolymer structure.

CONCLUSIONS— 20 790 6 5 02

Claims (6)

1. Process for preparing copolymers of vinyl acetate, ethylene and peroxyalkyl acrylate, characterized in that the copolymer corresponding to formula 1 is stated on the formula sheet, wherein a normal alkyl group is -CE 1, -C 1, -C 1 , -C ^ H ^ or -Ο, -Η ^, R2 represents a group of formula 2 indicated on the formula sheet or -O-CiCH ^) ^ »where x = 24.0-89.9 mol%, y = 10 .0-75.0 mol% and z = 0.1-1.0 mol%, is prepared by reacting vinyl acetate, ethylene and peroxyalkyl acrylate under the influence of a radical initiator in an organic solvent or an aqueous solution of surfactants and / or polymeric protective colloids at a temperature of 20-70 ° C and a pressure of 15-100 kgf / cm, followed by separation of. the desired end product. 2. Process according to claim 1, characterized in that as peroxyalkyl-15 acrylate use is made of compounds of general formula 3, indicated on the formula sheet, wherein R 1 is a normal alkyl such as -CH 2, "C 2%, -C -H_, -C, H_ or -Cj-H .. and R_ represents a group of formula 2, indicated either * yowd on the formula sheet or -O-CfCKj) ^ · 3. Process according to claims 1-2, characterized in that as a radical initiator use is made of azobisisobutyronitrile, potassium persulfate or a potassium persulfate-sodium metabisulfate redox system. 4. Process according to claims 1-3, characterized in that tertiary butyl alcohol is used as the organic solvent. 5. Process according to claims 1-4, characterized in that as the aqueous surfactant solution use is made of an aqueous solution of sodium lauryl sulfate, 3,5-dinonylphenyloxydecaethylene oxide or a block copolymer of ethylene oxide and propylene oxide. 6. Process according to claims 1-5, characterized in that as the aqueous solution of a polymeric protective colloid 5 use is made of an aqueous solution of polyvinyl alcohol with 1.2 to 1.5% by weight of acetate units or hydroxyethyl cellulose. 790 65 02 -14- 20901 / Vk / iv -FORMULA SHEET- R - CH2Jy- (CH2 - 4¼ 0 0 = .0 I · 1 C0CH3 0 S2 · J '- CH - ®3 3' -Ej ^ 4 - 0 - c (ch3) 3 ch 0 = 0 0 • R2 790 6 5 02