DE3432364A1 - METHOD FOR PRODUCING LOW MOLECULAR ACRYLAMIDE POLYMERISATS - Google Patents

Description

The invention relates to an improved process for the production of low molecular weight, water-soluble polymers and copolymers of acrylamide by inverse emulsion or solution polymerization using a Chain transfer agent.

The solution or emulsion polymerization of acrylamide is known. According to the prior art, aliphatic Alcohols such as isopropyl alcohol, ethanol and methanol as chain transfer agents for the solution polymerization of Acrylamide used. Other methods see the use of various sulfur and organic sulfur compounds chain transfer agents such as thioglycol, thioglycolic acid, and n-dodecyl mercaptan; See U.S. Patent 4,196 and 4,245,072. In a process used for the solution polymerization of acrylamide, redox initiators are used, in which the bisulfite ion acts as a chain transfer agent.

U.S. Patent 4,307,215 teaches the use of formic acid and alkali metal formates as chain transfer agents the conditions of the inverse emulsion polymerization.

All conventional connections involve difficulties that make commercial use difficult or impossible do. For example, they are either not effective enough and require molecular weight reduction to be achieved high concentrations (of chain transfer agents) or they have a strong, stinging effect Odor, which is often transferred to the finished polymers, what their commercial uses severely restricts. Some compounds are corrosive or toxic while others are powerful retarders exert on the acrylamide polymerization and thus contribute to a loss of productivity.

The object of the invention is that which occur in the prior art Eliminate difficulties. The invention No solution to this can be found in the state of the art.

The invention relates to a process for the preparation of a polymer or copolymer by inverse, aqueous Emulsion polymerization of a component selected from the group

(I) acrylamide,

(II) methacrylamide and

(III) a mixture of 10 to 90 percent of (I) or (II) and a monomer from the group acrylic acid, methacrylic acid, N, N-dimethylaminoethyl methacrylate, Sodium acrylate, isopropyl acrylamide and acrolein,

in the presence of at least one surfactant, at least one free radical initiator and one Chain transfer agent to limit the molecular weight and thus to lower the viscosity of the polymer or Copolymer solution, the chain transfer agent being selected from the group consisting of erythorbic acid (isoascorbic acid) as well as their alkali metal salts, ascorbic acid and their alkali metal salts, vitamins and butylated hydroxytoluene.

The chain transfer agents used in practicing the process of the present invention are known Compounds that are largely used as additives in the food and beverage industry. they are Easily accessible, safe to use and do not have the toxicity and health risks of conventional compounds on. This is particularly important because the polymers formed in various cosmetic preparations and can also be used as additives in the food industry.

Using emulsion polymerization techniques, the present invention overcomes those of high viscosity

557.077 - 6 -

and difficulties associated with low heat transfer. As a result, the ratio of water to monomer are kept quite low, whereby the amount of polymer formed in a given reaction mixture increases will.

In the practical implementation of the method according to the invention a high polymerization temperature is not required. This determines the extent of the polymer branching reduced, which improves the product quality. In view of the high energy costs, the low polymerization temperature leads also to an increase in the economic efficiency of the process.

An emulsion is generally obtained by forming a phase in the form of very fine droplets (i.e. the dispersed Phase) in another phase (i.e. the continuous phase) in the presence of a suitable surfactant dispersed. The most common form of emulsion is the oil-in-water emulsion, in which oil is the disperse phase and water is the represents continuous phase. Another form of emulsion is the water-in-oil emulsion, in which water is the dispersed one Phase represents. Such an emulsion is sometimes also referred to as an inverse emulsion. Unless otherwise is indicated, the term emulsion as used herein refers to water-in-oil emulsions only.

As is known, surface-active agents can be classified according to the HLB system (HLB = hydrophile-lipophile balance). Generally, the surfactants used to make water-in-oil emulsions are surfactants to oil soluble products having an HLB range of from about 1 to 12, and preferably from about 4 to 6. The required HLB range can also be made using mixtures of surfactants, including ionic and

nonionic surfactants. Suitable surfactants include sorbitan fatty acid esters, Mono- and diglycerides of fatty acids, polyoxyethylene sorbitol esters, polyethylene sorbitan fatty acid esters and polyoxyethylene alcohols.

The total concentration of surfactants used can be from 0.5 to 20.0 parts by weight per 100 parts by weight of the oil phase and preferably from about 2.0 to 15.0 parts by weight.

Acrylamide is generally polymerized in an inert atmosphere (e.g. Np or COp) at a pH of about 3 to 8. If the pH is higher than about 9, the amide groups can be hydrolyzed. At a pH of less than about 2.5, imidation often takes place due to the formation of a crosslinked, water-insoluble polymer. Thus, in the practical implementation of the invention Method the preferred pH range is about 3 to

The ratio of water to oil phase is practical Carrying out the method according to the invention is decisive for the stability and the degree of efficiency. Generally amounts to the ratio of water to oil phase about 1: 5 and preferably about 1: 2. It can also be a ratio of water to an oil phase of 1: 1 or even 2: 1, provided the emulsion obtained is stable. Since the monomer in If the water phase is dissolved, it is best to keep the concentration of the oil phase as low as possible to get in a given approach to increase the polymer yield.

The polymerization temperature is generally in the range of about 20 to about 80 ° C and preferably in the range of about 25 to about 6O ⁰ C.

In the case of the free radical-forming used according to the invention Initiators are known initiators of the organic peroxide and azo compound type. Examples suitable initiators are listed below: tert-butyl peroctoate, tert-amyl peroctoate, tert-butyl peroxypivalate, tert-amyl peroxypivalate, X-cumyl peroxypivalate, tert-butyl peroxyneohexanoate, tert-amyl peroxyneohexanoate, tert-butyl peroxyneodecanoate, tert-amyl peroxyneodecanoate, Dibenzoyl peroxide, diacetyl peroxide, dilauroyl peroxide, di- (2-ethylhexyl) peroxydicarbonate, Di- (phenoxyethyl) peroxydicarbonate, 1,1-di- (tert-butylperoxy) -cyclohexane, 1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di- (2-ethylhexanoylperoxy) -hexane, 2,5-dimethyl-2,5-di- (benzoylperoxy) -hexane, Di-tert-butyl peroxide, di- (tert-butyldiperoxy) azelate, tert-butylcumyl peroxide, azo-bis-isobutyronitrile, 2,2'-azo-bis (2,4-dimethylvaleronitrile), 2-tert-butylazo-2-cyano-4-methoxy-4-methylpentane, 2-tert-butylazo-2-cyano-4-methylpentane, 2-tert-butylazo-2-cyanopropane, 2-tert-butylazo-2-cyanobutane, 1-tert-butylazo-1-cyanocyclohexane, tert-butyl hydroperoxide and cumene hydroperoxide.

It can also use water-soluble, free radical initiators, such as potassium persulfate, ammonium persulfate and hydrogen peroxide can be used.

A mixture of 2 or more initiators which form free radicals can also be used. The initiator concentration ranges from about 0.005 to about 5.0 parts by weight per 100 parts by weight of monomer and is preferred from about 0.05 to about 2.5 parts by weight per 100 parts by weight of monomer.

According to the invention, acrylamide or methacrylamide are formed with the formation of low molecular weight, nonionic homopolymers polymerized. However, it is also possible to use them with a

or to copolymerize more comonomers. Examples of suitable comonomers are acrylic acid, methacrylic acid, N, N-dimethylaminoethyl methacrylate, Sodium acrylate, isopropyl acrylamide and acrolein. It is known to the person skilled in the art that these comonomers can be selected to form cationic or anionic polyelectrolytes.

During the copolymerization, the concentration of acrylamide (or methacrylamide) is about 10 to 90 percent by weight of total monomer and preferably about 10 to 75 percent by weight.

By definition, chain transfer agents are used as controls the growth of the polymer chain and thus the molecular weight. Under idealized conditions these compounds should not have any effect on the rate of polymerization to have. They are used in a concentration of about 0.001 to 5.0 parts by weight per 100 parts by weight Monomer, and preferably from about 0.01 to 2.5 parts by weight per 100 parts by weight of monomer.

The following are effective chain transfer agents in the present invention listed:

Erythorbic acid and its alkali metal salts, such as sodium erythorbate, Ascorbic acid and its alkali metal salts, vitamins such as niacin, vitamin E and riboflavin, and butylated Hydroxytoluene (BHT).

When the method according to the invention is carried out in practice, taking into account availability and costs preferred as chain transfer agents are sodium erythorbate, erythorbic acid and butylated hydroxytoluene. These Connections apply according to the provisions of the FDA (Food & Drug Administration) as antioxidants suitable for food use; see Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 3, 3rd ed., p. 140, table

In addition, they do not have a specific tolerance concentration, which indicates that they are safe in any concentration can be used as additives in food. Thus, the preferred chain transfer agents of the invention alone or in combination with other compounds for the production of low molecular weight acrylamide polymers, that can come into contact with food safely.

The invention is explained in more detail below with the aid of examples.

Definitions of the materials used in the examples

OMS: Shell Sol-71 odorless mineral spirits from Shell Oil Co.

Span ^ 80: Sorbitan monooleate from ICI Americas, Inc. EA: Erythorbic acid from Pfizer Inc. NaEA: Sodium erythorbate from Pfizer Inc.

monomeric acrylamide: "Fisher Reagent" for reagent purposes from Fisher Scientific

50 percent aqueous solution of monomeric acrylamide, inhibited with about 25 ppm copper (Cu) from Dow Chemicals triple distilled water from Queen City Pure Water (Buffalo N.Y.). Before use, this water is allowed to boil and cool under an Np atmosphere. Until use it is stored under N ^ atmosphere. Lupersol ^ 223M75: Di- (2-ethylhexyl) peroxydicarbonate

by Lucidol Div. Pennwalt Corp. 80: Diethylenetriaminepentaacetic acid, chelate

Forming agent from Dow Chemicals 6H: azo-bis-isobutyronitrile from DuPont Vazo® 52: 2,2-azo-bis- (2,4-dimethylvaleronitrile)

by duPont
BHT: butylated hydroxytoluene, 2,6-di-tert.-

butyl-p-cresol, 2,6-di-tert-butyl-4-methyl-

phenol from Aldrich Chemical Co., Inc.

10 -

557,077

Riboflavin: Vitamin Bp from Roche

Vitamin E: χ-tocopheryl acetate from Vornado, Inc.

Niacin: Nicotinic acid from Lonza

Formic acid: A.C.S. - Fisher Scientic Company Certificate monomeric acrylamide: "99+% Electrophoresis Grade Gold Label"

from Aldrich Chemical Company, Inc. ^K 2 ^S 2 ° 8 ^: Potassium persulfate, "Baker Analyzed Reagent" from

JT Baker Chemical Co.
Lupersol ^ 256: 2,5-dimethyl-2,5-di- / ~ 2-ethylhexanoylpe-rox_y_7-

hexane, the Lucidol Div. from Pennwalt Corporation Lupersol ^ 331-8OB: 1,1-di- / tert-butylperoxyV-cyclohexane der

Ludicol Div. by Pennwalt Corp. DS-606: 4- (tert-Butylperoxycarbonyl) -3-hexyl-6- (7- (tert-Butylperoxycarbonyl) -heptyl) -cyclohexene the

Lucidol Div. by Pennwalt Corp. Lupersol ^ TA-54M75: tert-amyl peroxypivalate from Lucidol Div.

by Pennwalt Corp.

Standard procedure

composition Parts by weight Acrylamide 50 3 times distilled water 50 OMS 200 Span® 80 20th initiator 0.05 or upon need

Chain transfer agent

procedure

Using a three-beam balance (Ohaus), 50 g of solid, monomeric acrylamide are weighed out and stirred (at Room temperature) dissolved in 50 g of triple distilled water. In a corresponding manner, 20 g of Span ^ 80 are weighed out and dissolved in 200 g of OMS. These two solutions are combined in one

- 11 -

557,077 - 12 -

Stainless steel warring mixer mixed at high speed for about 3 minutes to form a water-in-oil emulsion. This emulsion is then in a 1 liter (jacketed) glass reaction vessel, which is equipped with a stirrer, a Reflux condenser, a thermometer and a nitrogen inlet tube is equipped, transmitted. The reaction vessel itself is placed in a thermostated (+0.1 C) water bath, which is set to the desired reaction temperature (e.g. 35 C), immersed. Before adding the initiator is the emulsion was flushed with nitrogen for about 1/2 hour while stirring .

The required amount of initiator is measured using a Mettler analytical balance (+ 0.0001 g) in tared, glass Weighing vessels ("petticups") balanced. The weighing vessel is then placed in a 10 ml beaker. The solution obtained after adding 5 ml of acetone is added to the stirred solution Emulsion added. The beaker with the weighing vessel is rinsed again with a few ml (2 to 5 ml) of acetone, and the contents are also added to the reaction vessel. At this point an electric stopwatch is used started to indicate the start of polymerization.

If a chain transfer agent is used, it is weighed out appropriately and placed in the reaction vessel with the exception that the choice of solvent depends on the chain transfer agent used, e.g. water for EA, OMS for BHT, water / methanol for riboflavin. However, the initiator is always the last component added to the reaction vessel.

At predetermined time intervals, emulsion samples are taken from the reaction vessel using a subcutaneous syringe with a needle. After weighing, the emulsion sample becomes

- 12 -

precipitated in acetone or methanol with stirring. Syringe and Needles are weighed back to determine the weight of the emulsion sample. The precipitated polymer is on Filtered on pre-weighed filter paper and dried at about 50 C to constant weight (generally about 12 hours). From the determined solids content calculate the percentage of conversion.

For the polymerization of an aqueous acrylamide solution (from Dow Chemicals) the monomer is first used at 0.2 parts by weight Versenex® 80 (chelating agent) per 100 parts by weight of monomer treated to remove the inhibitor (copper). The subsequent procedure is the same as that described above for solid, monomeric acrylamide.

Measurement of the viscosity of the polymer solution

The dry polymer is first about 3 minutes in a micromill (model no.502 from Technilab Instruments) ground. Subsequently, 0.00 g of polymer are mixed with 24 ml of methanol with stirring in a 250 ml beaker mixed. After the polymer has crosslinked completely, 198 ml of triple distilled water are quickly added. After stirring for a further 5 minutes, a 1.8 percent strength aqueous polymer solution is obtained, which is used for viscosity measurement is used.

The viscosity is measured at 25 ° C with a Brookfield viscometer, Model RVF determined with a No. 4 spindle and a speed of 4 rpm.

Unless otherwise noted, this will be the standard procedure used in all examples.

example 1

This example explains the use of EA and NaEA as a

- 13 -

, 077

Chain transfer agents along with different types of free radical initiators. The results are compiled in Table I.

EA was used at a concentration of 0.1 g per 100 g of monomeric acrylamide and NaEA at a concentration of 0.2 g per 100 g monomeric acrylamide is used.

The initiators were used at a concentration of 0.1 g per 100 g of monomer after checking for any differences corrected in the test conditions.

Table I.

Initiator chain over polymer Brookfield viscosity

Carrying percentage of a 1.8% polymer time (min) conversion of merizate solution at 25 ° C

(Centipoise).

luazxß 55
EA 400
360 74
75 14,000
2,500 VazcP 52
EA 245
260 100
100 26,000
7 900 LupersoJ® 256 -
EA 300
300 100
100 24 500
4,500 LupersolV 256 -
NaEA 300
240 100
100 24 500
4,500

Polymerization temperature: 35 C

In game 2

The vitamins listed in Table II have been used successfully as chain transfer agents along with various free ones Free radical initiators used.

The initiators were used at a concentration of 0.1 g per 100 g of monomeric acrylamide, after any

- 14 -

557,077

Differences in test conditions had been corrected.

The concentration of the vitamins used is given in Table II in g per 100 g of monomeric acrylamide.

® 331-80B Chain over Table II Poly Per Brookfield-Vis initiator bearing concentration mer isa- Zen kosity one middle of the chain functional tuale 1.8% poly transmission _ Time Conversion merisat solution by means of (min) lung at 25 C (g / 100 g monomer) (Centipoise) Vitamin B- 300 100 14 800 Lupersof- '' (Riboflavin) - 300 98 1,000 256 _ 0.2 360 85 19 500 Vitamin E. 360 57 3,000 niacin 0.66 360 53 4,800 niacin 0.1 360 56 ' 4,000 0.05

Polymerization temperature: 35 C

Example 3

The standard procedure was repeated except that a reaction temperature profile was used. DS-606 is a sequential initiator in which the peroxide has 2 initiator groups with different calving life activity. The temperature profile consists of 4.5 hours at 35 ° C, then increasing to 45 ° C and 1 1/2 hours Leave at this temperature.

EA was used at a concentration of 0.1 g per 100 g of monomeric acrylamide.

DS-606 was used at a concentration of ~ 0.1 g per 100 g monomeric acrylamide used after looking for any differences

- 15 -

557,077

corrected in the test conditions. From the sequential Initiators are known to form high molecular weight polymers. This example shows (see table III) that EA is suitable for use in conjunction with this type of free radical generating initiator Represents chain transfer agent.

Table III

Initiator chain over- polymer concentration tuale mean time (min) conversion

DS-606

EA

360 300

100 100

Brookfield viscosity of a 1.8% polymerization solution at 25 C (centipoise)

38,000
2,800

Example 4

BHT is a food-grade antioxidant. Certain vitamins such as ascorbic acid (vitamin C) and Λ, tocopheryl acetate (vitamin E) antioxidants This example illustrates the use of BHT as a chain transfer agent (see Table IV).

BHT was used at a concentration of 0.1 g per 100 g of monomeric acrylamide.

Lupersol- ^ 331-8OB (initiator) was used in one concentration of 0.1 g per 100 g of monomeric acrylamide, correcting for any differences in test conditions.

- 16 -

557,077

- 17 -

Chain over
bearing
middle Tabel IV Brokkfield viscosity one
1.8% polymerisation
solution at 25 C
(Centipoise) initiator BHT Polymeri
station
time (min) percent
tuale
Conversion
lung 19 500
5,500 Luper sol--
331-80B BHT 360
360 85
74 27 500
9 500 Luperso]> -
223M75 300
360 100
80

O,

Polymerization temperature: 35 C

Example 5

The following procedure was used in this example: Solid acrylamide was dissolved in 3-fold distilled water until a clear solution was obtained. This solution was poured into a glass reaction vessel which had been preheated to the reaction temperature either with a heating mantle or with a water bath. The reaction vessel was equipped with a stirrer, an Np inlet device, a thermometer and a reflux condenser. The stirrer and the introduction were started. After 1/2 hour, the initiator dissolved in ~ 5 ml of acetone was added to the reaction vessel and the stopwatch was started. The small beaker used to dissolve the initiator was rinsed with 3 to 5 ml of acetone. The rinsing liquid was added to the reaction vessel. The ingredients used are given below:
25 grams of monomeric acrylamide
500 g triple distilled water
1.0 phro initiator
1.0 phm chain transfer agent.

When the chain transfer agent was used, it became

- 17 -

557,077 - 18 -

aqueous monomer solution added before adding the initiator.

The molecular weight was determined by Verdünnungsviskosimetrie using a Cannon-Ubbelhode Verdünnungsviskosimeters (no. 75) was immersed in a thermostated water bath ⁽⁰ + 1 C). The value M was determined using the Mark-Houwink equation l ~ r> 1 - KM, where K = 6.80 χ 10 dl / g, cc = 0.66 and ] _r> _l = intrinsic viscosity for polyacrylamide in Water at 30 ⁰ C.

This example shows (see Table V) that EA has been successful in lowering the molecular weight of by solution polymerization produced polyacrylamide can be used without causing a significant delay in the rate of polymerization comes.

Table V

Initiator chain reaction percentage viscometrically determined extrapolated molecular weight average M medium (min) Conversion at 30 C in 3-fold distilled water

tert-amyl

peroxy- - 60 82 966 100

pivalate

Luperso] ® EA 80 89 75 700

TA-54M75

Polymerization temperature: 35 C

Example 6

Various oil-soluble organic peroxides were used in the above examples. This example explains the Suitability of EA as a chain transfer agent together with water-soluble initiators (see Table VI). The initiator

- 18 -

557,077

was used at a concentration of 0.1 g per 100 g of monomer, correcting for different test conditions.

Chain Tabel VI Per Brookfield-Vis'kosi initiator transferred concentration Poly- centu did gearing of chains merisa- all around middle transmission functional Wall at 25 C by means of Time lung (Centipoise) _ (g / 100 g monomer) (min) 100 10 800 Potassium per _ 60 sulfate EA 100 400 ^K 2 ^S 2 ° 8 0.1 60

Polymerization temperature: 35 C

Example 7

To study the effect of EA on the reaction, the initiator concentration was adjusted to 0.1 g per 100 g of monomer (0.1 phm) kept constant and the EA concentration initially varied from 0.1 g to 4.0 g per 100 g of monomer.

Then 2 further polymerizations were carried out in which the EA concentration was 0.1 g per 100 g of monomer (0.1 phm) and the initiator concentration varied from 0.2 to 0.3 phm.

The results in Table VII show that as the initiator concentration increases the rate of polymerization increases. However, the molecular weight of the polymer decreases due to the reduced EA concentration in relation to the initiator concentration. Thus, EA is an effective one Chain transfer agent, where the ratio of EA to initiator can be critical.

- 19 -

Table VII
^ '. ¹ Y ^ft Ci '■ ⁽ ' J ^{7 '11 l} ii ¹ Il ° ⁿ -'P ⁰ ^ yITKu Is ation of acrylamide at 35 C.

I π i t. i : \ I.or: Lupor.'W) 1 «'■'';(); Zunntz: f.iry thorbic acid

initiator additive Time percentage Viscosity at (phm) (phm) (min) conversion 25 C (Cp) 0.1 0.1 360 79 125 0.1 0.25 360 73 125 0.1 1.0 360 59 125 0.1 4.0 360 41 <100 0.2 0.1 240 100 1 250 0.3 0.1 120 100 5 750

Viscosity: Brookfield viscosity of a 1.8% solution using a # 4 spindle and 4 rpm.

Example 8

The standard procedure was used, with the exception that the polymerization temperature was 45 ° C and that to prepare the aqueous acrylamide solution, not 50.0 g of solid, monomeric acrylamide was weighed out and 50.0 g of triple distilled water was added, but 100 g of a commercially available 50 percent acrylamide solution were weighed into a beaker. This commercial solution was 25 ppm CuSO ₁ . inhibited. Normally a chelating agent would have to be added prior to making an emulsion. For the reactions listed in Table VIII, however, no additions were made.

R 2+

Set of Versenex 80 as a chelating agent to remove the Cu inhibitor.

The initiator was added in an amount of 0.1 g / 100 g monomer, correcting for the test conditions. The chain transfer agent EA was added in an amount of 0.1 g / 100 g of monomer prior to addition of the initiator.

- 20 -

557,077

It is found that EA is an effective way of increasing molecular weight of the polymer decreases, while there is only a slight decrease in the rate of polymerization results.

Chain over Tabel VIII Brookfield viscosity initiator bearing Polymeri a 1.8% poly middle station percentage merisate solution at 25 ° C time (min) conversion (Gentipoise) _ 16 300 Luazo 70 EA 300 97 7,300 360 99

For comparison purposes, formic acid was tested for suitability as a chain transfer agent using the standard procedure investigated this experiment. The initiator was added in an amount of 0.1 g / 100 g of monomer. Formic acid was also used in an amount of 0.1 g / 100 g of monomer, which is typically used in the case of erythorbic acid or BHT Reduction in the molecular weight of the polymer amount used, added.

U.S. Patent 4,307,215 teaches the use of formic acid and alkali metal formates as very effective chain transfer agents for acrylamide. As can be seen from Table A, the rate of polymerization was greatly retarded when formic acid was used as a chain transfer agent, which was not the case with the chain transfer agents of the present invention, i.e. EA, BHT and the like. This delay the reaction rate is undesirable for large-scale industrial processes. Formic acid is also corrosive and therefore requires special precautionary measures during handling in order to ensure the longevity of the system and the Ensure the safety of employees.

- 21 -

, ΟΊΊ

For the polymer produced using formic acid No viscosity value is given in Table A because the final percent conversion is very low was and very little polymer could be obtained.

Table A.

Initiator chain over polymer Brookfield viscosity

Carrying percentage of a 1.8% polymer time (min) conversion of merizate solution at 25 ° C

(Centipoise)

Lupersol ant-256 acid

360

300

18th

100

24 500

Polymerization temperature: 35 C

- 22 -

Claims (9)

Claims 1. Process for the production of a polymer or copolymer, characterized by inverse, aqueous emulsion polymerization of a component from the group (I) acrylamide (II) methacrylamide and (III) a mixture of 10 to 90 percent (I) or (II) and a monomer from the group acrylic acid, methacrylic acid, N, N-dimethylaminoethyl methacrylate, Sodium acrylate, isopropyl acrylamide and acrolein, in the presence of at least one surfactant, at least one free radical initiator and a chain transfer agent to limit the molecular weight and viscosity of the polymer or Copolymer, the chain transfer agent being selected from the group consisting of erythorbic acid (isoascorbic acid) Munich - Bogenhausen Phone: Telex: Fax (II & 111 - automat.): mom nc to ίί 'Telegram: (ilflVlilulUN Mlill and their alkali metal salts, ascorbic acid and their alkali metal salts, vitamins, butylated hydroxytoluene and mixtures thereof. 2. The method according to claim 1, characterized in that the chain transfer agent in an amount of about 0.001 to about 5.0 parts by weight per 100 parts by weight of monomer. 3. The method according to claim 2, characterized in that the chain transfer agent is erythorbic acid or sodium erythorbate. 4. The method according to claim 2, characterized in that the inverse, aqueous emulsion polymerization in one Water-in-oil emulsion is carried out using the water the disperse phase and the oil represents the continuous phase. 5. The method according to claim 2, characterized in that the surface-active agent or agents are oil-soluble and have a hydrophile-lipophile balance (HLB) range of about 1 to 12. 6. The method according to claim 3, characterized in that the surface-active agent or agents in an amount of from about 0.5 to about 20.0 parts by weight per 100 parts by weight of the oil phase. 7. The method according to claim 4, characterized in that the ratio of the water phase to the oil phase is about 1: 1 to 1: 5. the polymerization temperature is about 20 to about 80 ^{0 C} 8. The method according to claim 2, characterized in that the Pc
wearing. 9. The method according to claim 2, characterized in that at least one initiator forming free radicals in the Polymerization medium in an amount of from about 0.005 to about 5.0 parts by weight per 100 parts by weight of monomer is available.