GB1562417A

GB1562417A - Manufacture of sedimentation-stable water-in-oil dispersions of acrylamide polymers

Info

Publication number: GB1562417A
Application number: GB50063/76A
Authority: GB
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1975-12-02
Filing date: 1976-12-01
Publication date: 1980-03-12
Also published as: SE7613551L; IT1066713B; ATA890176A; FR2333815B1; SE423393B; AT347127B; FR2333815A1

Description

(54) MANUFACTURE OF SEDIMENTATION-STABLE WATER-IN-OIL DISPERSIONS OF ACRYLAMIDE POLYMERS (71) We, BASF AKTIENGESELLSCHAFT, a German Joint Stock Company of 6700 Ludwigshafen, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a process for the manufacture of a sedimentation-stable water-in-oil dispersion of an acrylamide polymer by polymerizing a water-in-oil emulsion of an aqueous acrylamide solution, which may or may not contain one or more other water-soluble ethylenically unsaturated monomers, in a hydrophobic organic dispersion medium in the presence of a polymerization initiator and an emulsifier.

The manufacture of water-in-oil dispersions of acrylamide polymers is disclosed, for example, in German Patent 1,089,173 and German Laid-Open Application DOS 2,226,143. Examples of emulsifiers which are given are sodium hexadecyl-phthalate sorbitan monooleate, sorbitan monostearate and sodium cetyl stearyl phthalate. However, with these emulsifiers it is not possible to produce, in every case, stable, substantially coagulate-free water-in-oil dispersions of the polymers by polymerizing a water-in-oil emulsion of an aqueous acrylamide solution or of a solution of acrylamide and an acid or basic comonomer. Instead, the emulsifier has to be matched to the particular monomer combination used if reasonably stable water-in-oil dispersions of acrylamide polymers are to be obtained. The presence of only a few per cent by weight of a coagulate has an adverse effect when the water-in-oil dispersions of polyacrylamides are used, particularly when they are used for the manufacture of paper.

The present invention seeks to provide an emulsifier for the above process which gives stable water-in-oil dispersions of acrylamide polymers and can furthermore be employed with a variety of monomer combinations used for the manufacture of polyacrylamides.

According to the invention there is provided a process of the type defined at the outset wherein the water-in-oil emulsifier used is a compound which is obtained by reacting one or more saturated or unsaturated fatty alcohols of 10 to 22 carbon atoms with epichlorohydrin in a molar ratio of from 1:0.5 to 1:1.5 to give a glycidyl ether and reacting the latter with a polyhydric alcohol of 2 to 6 carbon atoms, which contains from 2 to 6 hydroxyl groups, or a monoether thereof with a fatty alcohol of 10 to 22 carbon atoms, in a molar ratio of glycidyl ether to alcohol of from 1:0.5 to 1:6.0, in the presence of an acid or a base and, if desired, then oxyalkylating the resulting reaction product with from 1 to 6 moles of one or more alkylene oxides of 2 to 4 carbon atoms.

The manufacture of such emulsifiers is disclosed in German Laid-Open Applications DOS 2,455,287 and 2,536,597. An example of a method for the manufacture of such an emulsifier is to produce the glycidyl ether and its reaction product with the polyhydric alcohol or monoether thereof in a one-step reaction, in which the fatty alcohol and epichlorohydrin in the stated molar ratios, and the polyhydric alcohol or monoether thereof, also in the stated molar ratios, which in this case are based on epichlorohydrin, are reacted conjointly in the presence of the acid catalyst and then of the basic catalyst. In this case, the glycidyl ether ef the polyhydric alcohol or monoether thereof, which in turn is capable of addition reaction with the fatty alcohol, may form alongside the fatty alcohol glycidyl ether.

In a further variant, the fatty alcohol glycidyl ether is first produced but is not isolated. and instead the polyhydric alcohol or monoether thereof is added to the reaction mixture and the addition reaction of the glycidyl ether with the polyhvdric alcohol or monoether is then carried out in the same reaction vessel.

The two variants can also advantageously be implemented by carrying out the acid-catalyzed addition reaction of the epichlorohydrin and then effecting the elimination of hvdrogen chloride from the chlorohydrin by means of solid alkali metal hydroxide powder. In each case, the desired water-in-oil emulsifiers are formed.

One of the starting material for the manufacture of the emulsifier to be used according to the invention is one or more fatty alcohols (which term includes synthetic long-chain alcohols) of 10 to 22 carbon atoms, e.g. oleyl alcohol, stearyl alcohol, cetyl alcohol, linolenyl alcohol, myristyl alcohol, lauryl alcohol, tallow fat alcohol, and industrially manufactured alcohol mixtures, e.g. Alfols of 20 to 22 carbon atoms. Alfols of 16 to 18 carbon atoms, oxo-alcohols of 17 to 19 carbon atoms and oxo-alcohols of 9 to 11 carbon atoms (Alfol is a Registered Trade Mark).

Of course, mixtures of the alcohols, above all mixtures of the naturally occurring alcohols named above, may be used.

In the first stage of emulsifier production, the alcohol(s) is/are reacte.d with epichlorohydrin using a molar ratio of alcohol to epichlorohydrin of from 1:0.5 to 1:1.5, preferably 1:1.

Another starting material for the production of the emulsifier is a polyhydric alcohol of 2 to 6 carbon atoms containing from 2 to 6 hydroxyl groups, or a monoether thereof derived from a fatty alcohol as defined above. Examples of such materials are diethylene glycol, dipropylene glycol, butane-l,4-diol, butane-1,2,4triol, glycerol, trimethylolpropane, sorbitol, sorbitan, neopentyl glycol, pentaerythritol and, as ethers, the monoethers of the alcohols just mentioned, preferably of glycerol, with stearyl alcohol, oleyl alcohol and other alcohols defined above, e.g. I-oleyloxy-propane-2,3-diol. The fatty alcohol ethers of glycerol may, for example, be formed during the reaction by opening of the epoxide ring of the fatty alcohol glycidyl ether, but can also be produced in the conventional manner from the fatty alcohol and glycidyl or by hydrolysis of the fatty alcohol glycidyl ether, and can react as such, or in a mixture with the above polyhydric alcohols, with the fatty alcohol glycidyl ethers.

Acid or basic (alkaline) catalysts are used for the reaction of the glycidyl ethers with the polyhydric alcohols. Amongst acid catalysts, specific examples are, above all, Lewis acids, e.g. boron trifluoride etherate, boron trifluoride/phosphoric acid, boron trifluoride/acetic acid, boron trifluoride hydrate, boron trifluoride alkylglycol-etherate, tin tetrachloride, zinc chloride, titanium tetrachloride or aluminum chloride, and also inorganic acids, e.g. sulfuric acid; advantageous basic (alkaline) catalysts are alkali metal hydroxides, alkali metal alcoholates and alkaline earth metal alcoholates.

Of course it is also possible to react different glycidyl ethers, mixed with one another or used successively, with the polyhydric alcohol or monoether thereof or with a mixture of polyhydric alcohols and/or monoethers thereof.

An advantageous method of carrying out the reaction is to add the acid catalysts to the polyhydric alcohol or monoether thereof under an inert gas atmosphere at from 5 to 500C, preferably from 20 to 300C,- and to add the appropriate molar amount of glycidyl ether in the course offrom 5 to 60 minutes, whilst maintaining the reaction temperature at from 50 to 800 C. The reaction mixture is in general left at the chosen temperature for from I to 10 hours, preferably from 2 to 8 hours, whilst being agitated mechanically. Thereafter the catalyst is neutralized and the emulsifier is obtained directly. If, on the other hand, alkaline catalysts are chosen, the reaction temperatures maintained are from 150 to 220"C, but in other respects the procedure followed is as described above.

The emulsifiers described above can also, if desired, be subsequently oxyalkylated with from I to 6 moles of one or more alkylene oxides of 2 to 4 carbon atoms. The oxyalkylation may be carried out by conventional methods in the presence of alkaline or acid catalysts at from 80 to 1500C.

Preferably, the adduct of from 1 to 3 units of ethylene oxide, 1 or 2 units of propylene oxide or one unit of butylene oxide with the reaction product obtained from the glycidyl ether and a polyhydric alcohol or monoether thereof is formed. I1 is also possible to employ mixtures of the alkylene oxides for the oxyalkylation, e.g. mixtures of ethylene oxide and propylene oxide or mixtures of ethylene oxide and 1,2-butylene oxide or isobutylene oxide. The addition reaction of the alkylene oxides may take place randomly or in the form of blocks.

The emulsifiers obtained are used according to the invention in the manufacture of u ater-in-oil dispersions of homopolymers and copolymers of acrylamide. The compounds copolymerizable with acrylamide which are suitable for use in the process of manufacture are water-soluble and possess an ethylenically unsaturated double bond: examples are esters of aminoalcohols with acrylic acid or methacrylic acid, and mixtures of the said monomers, amides of acrylic acid or methacrylic acid with diamines, methacrylamide, alkali metal salts or ammonium salts of vinylbenzylsulfonic acid and alkali metal salts or ammonium salts of acrylic acid, methacrylic acid. acrylamidopropanesulfonic acid and vinylsulfonic acid. The esters of aminoalcohols with acrylic acid or methacrylic acid, and amides of acrylic acid or methacrylic acid, are employed in a neutralized or quaternized form for polymerization. Further suitable ethylenically unsaturated, water-soluble monomers are described in U.S. Patents 3,418,237, 3,259,570 and 3,171,805. The acrylamide copolymers contain up to 90?', by weight, preferably from 2 to 75 " by weight, of a comonomer or of a mixture of several comonomers.

In order to manufacture water-in-oil dispersions, acrvlamide or a mixture of acrylamide with one or more comonomers is dissolved in water and the aqueous phase is then emulsified in a hydrophobic organic dispersion medium in the presence of the water-in-oil emulsifier to be employed according to the invention.

Suitable hydrophonic organic dispersion media are the liquids described, for example, in German Patent 1,089,173, e.g. aromatic, liquid hydrocarbons, e.g. toluene and xylene, perchloroethylene and aliphatic liquid hydrocarbons, e.g. paraffin oils. In general, saturated hydrocarbons of boiling point from 120 to 350"C are used. Either pure hydrocarbons or mixtures of 2 or more hydrocarbons may be employed. The use of a mixture of saturated hydrocarbons which contains up to 20% by weight of naphthenes is preferred. The saturated hydrocarbons in this mixture are n- and i-paraffins. The boiling range of the mixture is preferably from 192 to 254"C (determined according to ASTM D-l 078/86).

In addition to the water-in-oil emulsifiers to be employed in accordance with the invention, a wetting agent having an HLB value greater than 10 may be present during the manufacture of the water-in-oil dispersion of acrylamide polymer. The HLB value is the hydrophilic-lypophilic balance of the emulsifier, i.e. the equilibrium in size and strength of the hydrophilic and lypophilic groups of the emulsifier. A definition of this concept is to be found, for example, in "Das Atlas HLB-System", Atlas Chemie GmbH, EC 10 G, July 1971, and in Classification of Surface Active Agents by "HLB", W. C. Griffin, Journal of the Society of Cosmetic Chemists, page 311 (1950).

Suitable wetting agents with an HLB value greater than 10 are, for example, oxyethylated alkylphenols, sodium salts of dialkyl sulfosuccinates, where alkyl is of not less than 3 carbon atoms, soaps derived from fatty acids of 10 to 22 carbon atoms, and alkali metal salts of alkyl-sulfuric acids or alkenyl-sulfuric acids of 10 to 26 carbon atoms. The use of oxyethylated nonylphenols with a degree of oxyethylation of from 6 to 20, oxyethylated nonylphenolformaldehyde resins with a degree of oxyethylation of from 2 to 20, sodium salts of dioctyl-sulfosuccinates and octylphenol-polyethoxyethanol is preferred.

The emulsifiers to be employed in accordance with the invention are usually employed in amounts of from 1 to 10%, by weight, based on the total dispersion.

The above wetting agents having an HLB value greater than 10 may be present in an amount of from 0.1 to 100:, by weight, based on the total dispersion.

The monomer(s) may be polymerized in the presence of a conventional polymerization initiator, for example peroxides, e.g. benzoyl peroxide and lauroyl peroxide, hydroperoxides, hydrogen peroxide, azo compounds, e.g. azoisobutyronitrile, and redox catalysts. The polymerization temperature depends on the polymerization initiator used and may vary within wide limits, e.g. within the range of from 5 to 1200C. As a rule, polymerization is carried out under atmospheric pressure at from 40 to 80"C, with thorough mixing of the components.

The monomers undergo virtually complete polymerization.

The molecular weights of the acrylamide polymers obtained may also vary within wide limits. They are usually from 10,000 to 25,000,000, preferably from 1,000,000 to 10,000,000. The finished water-in-oil dispersion usually contains from 40 to 850,, of the aqueous phase, which in turn contains virtually the entire polymer.

The concentration of the polymer in the aqueous phase is usually from 20 to 60 percent by weight. The continuous outer phase of the water-in-oil polymer dispersion, i.e. the liquid hydrocarbons and the water-in-oil emulsifiers, usually accounts for from 15 to 60 ,n by weight of the total dispersion.

The water-in-oil dispersions of acrylamide polymers may be used, for example, as flocculation assistants for clarifying aqueous systems, in the manufacture of paper, in the treatment of sewage, as dispersing agents and protective colloids in drilling muds, and as assistants in the secondary production of petroleum from 'flooding waters. In every case, very dilute solutions are required, so that the waterin-oil dispersions manufactured according to the invention require dilution with water. The fact that the dispersions used for dilution are free from coagulate and sedimentation-stable is a substantial technological advantage.

The Examples which follow illustrate the invention. Parts and percentages are by weight.

The K values of the polymers were measured by the method of H. Fikentscher, Cellulosechemie 13 (1932), 58-64 and 71-74, in 5% strength aqueous sodium chloride solution, at 25"C; K=k. 103.

EXAMPLE 1 Manufacture of a water-in-oil dispersion of an acrylamide homopolymer.

The following components are mixed in a vessel provided with a stirred thermometer and nitrogen inlet and outlet: 344 parts of a mixture of 84% of saturated aliphatic hydrocarbons and 16% of naphthenic hydrocarbons (boiling range of the mixture: 192-2540C) and 56 parts of a reaction product of oleyl glycidyl ether and glycerol, manufactured as described in Example 1 of German Laid-Open Application DOS 2,455,287.

After thoroughly mixing the components, a solution of 213 parts of acrylamide and 387 parts of water is added and the aqueous phase is emulsified in the hydrocarbon oil. Nitrogen is then passed over the mixture for 30 minutes, after which the mixture is heated to 600C in the course of 15 minutes. At this temperature, a solution of 0.212 part of 2,2-azo-bis-isobutyronitrile in a little acetone is added. The polymerization has ended after the mixture has been kept for 3 hours at 60"C, whilst stirring. A coagulate-free water-in-oil polymer dispersion is obtained, which in the course of time shows sedimentation of a lower phase, richer in polymer, but which can readily be redispersed by slight agitation of the dispersion.

COMPARATIVE EXAMPLES I to 9 Example I is repeated several times, using, in each case, a conventional water in-oil emulsifier in place of the reaction product of oleyl glycidyl ether and glycerol. Table 1 shows the emulsifiers employed and the results of the experiments. As may be seen clearly from the Table, none of the water-in-oil emulsifiers of the prior art permit manufacture of the desired water-in-oil polyacrylamide dispersions without (some) coagulation of the dispersion.

TABLE 1 Behavior on Stability of the K value of Example Water-in-oil emulsifier polymerization resulting dispersion the polymer 1 oleyl hydroxyalkyl ether good good 222 of glycerol slight sedimentation Comparative coagulate-free Examples 1 sorbitan mono-oleate from coagulates - German Patent 1,089,173 2 sorbitan monostearate from coagulates - German Patent 1,089,175 3 reaction product of oleyl coagulates - alcohol with 2 moles of ethylene oxide 4 reaction product of tallow fatty coagulates - alcohol with 2 moles of ethylene oxide 5 sodium salt of monohexadecyl phtha- coagulates - late, from German Patent 1,089,173 6 sodium cetyl/stearyl phthalate from coagulates - German Patent 1,089,173 7 Lecithin A coagulates - 8 Lecithin B coagulates - 9 Lecithin C coagulates - - EXAMPLE 2 Manufacture of a water-in-oil dispersion of a polymer of acrylamide and sodium acrylate.

The following components are mixed in a vessel provided with a stirrer. thermometer and nitrogen inlet and outlet: 344 parts of a mixture of 84",, of saturated hydrocarbons and 16% of naphthenic hydrocarbons (boiling range of the mixture: 192--254"C) and 52 parts of a reaction product of oleyl glycidyl ether and glycerol (manufactured as described in Example I of German Laid-Open Application DOS 2,455,287). A solution of 74 parts of acrylamide and 104 parts of acrylic acid in 363 parts of water, the pH of the solution having been brought to 7 with 58 parts of sodium hydroxide, is then added and the aqueous solution is emulsified in the hydrocarbon oil. Nitrogen is then passed over the mixture for 30 minutes, and the mixture is heated to 600C in the course of 15 minutes. At this temperature, a solution of 0.212 part of 2,2'-azo-bis-isobutyronitrile in a little acetone is added. The polymerization has ended after the mixture has been stirred for 3 hours at 600 C. A coagulate-free, water-in-oil polymer dispersion is obtained, which in the course of time shows sedimentation of a lower phase richer in polymer. However, the sedimented phase can readily be redispersed by slight agitation of the dispersion.

COMPARATIVE EXAMPLES 10 to 18 In place of the emulsifier to be employed according to the invention (a reaction product of oleyl glycidyl ether and glycerol), conventional water-in-oil emulsifiers are used for the manufacture of the water-in-oil dispersions of the acrylamide copolymer. The polymerization conditions correspond to Example 2 and the emulsifiers employed, and the results, are summarized in Table 2. The Table shows that with none of the emulsifiers of the prior art was it possible to obtain water-in-oil polymer dispersions without coagulate, whilst this was possible with the water-in-oil emulsifier to be employed according to the invention.

TABLE 2 Behavior on Stability of the K value of Type of water-in-oil emulsifier Example polymerization resulting dispersion the polymer 2 oleyl hydroxyalkyl ether good good, 250 of glycerol sedimentation Comparative Examples 10 sorbitan mono-oleate from deposit on wall sedimentation 227 German Patent 1,089,173 large amount of coagulate 11 sorbitan monooleate from coagulates - German Patent 1,089,173 12 reaction product of oleyl alcohol coagulates - with 2 moles of ethylene oxide 13 reaction product of tallow fatty coagulates - alcohol with 2 moles of ethylene oxide 14 sodium salt of monohexadecylphtha- coagulates - late, from German Patent 1,089,173 15 sodium cetyl/stearyl phthalate from good, but 3% of sedimentation German Patent 1,089,173 coagulate 16 Lecithin A coagulates - 17 Lecithin B coagulates - 18 Lecithin C coagulates - - EXAMPLE 3 Manufacture of a water-in-oil dispersion of a copolymer of 25 ," of acrylamide and 75",, of acryloxyethyldiethylammonium sulfate.

The following components are mixed in a vessel provided with a stirred thermometer and nitrogen inlet and outlet: 344 parts of a mixture of 84 ," of saturated aliphatic hydrocarbons and 16% of naphthenic hydrocarbons (boiling range of the mixture: 192--254"C) and 62 parts of a reaction product of oleyl glycidyl ether and glycerol (manufacture as described in Example 1 of German Laid-Open Application DOS 2,455,287). A solution of 73.5 parts of acrylamide and 171 parts of diethylaminoethyl acrylate in 303 parts of water, the pH of which has been brought to 3 with 52 parts of sulfuric acid, is added to the above mixture. The organic phase is mixed with the aqueous phase, whilst stirring thoroughly, so as to form a water-in-oil emulsion. Nitrogen is then passed over the emulsion for 30 minutes and the emulsion is heated to 600C in the course of 15 minutes. At this temperature, 0.212 part of 2,2'-azo-bis-isobutyronitrile in acetone is added. The polymerization has ended when the temperature of the mixture has been kept at 60"C for 3 hours. A coagulate-free water-in-oil dispersion results, which after some time forms a lower phase, richer in polymer, which can however readily be redispersed by slight agitation of the dispersion.

COMPARATIVE EXAMPLES 19 to 27 Example 3 is repeated except that in place of the reaction product of oleyl glycidyl ether with glycerol, the same amount of the emulsifiers conventionally employed for the manufacture of water-in-oil dispersions is used. The emulsifiers employed and the results obtained are shown in Table 3. As may be seen from the Table, none of the emulsifiers of the prior art permitted the manufacture of coagulate-free water-in-oil polymer dispersions whilst, surprisingly, the manufacture of such a dispersion proved possible with the emulsifier employed in Example 3.

TABLE 3 Behavior on Stability of the K value of Example Type of water-in-oil emulsifier polymerization resulting dispersion the polymer 3 oleyl hydroxyalkyl ether good good, sedimenta- of glycerol tion, no coagulate Comparative Examples 19 sorbitan monooleate from good 142 mediocre sedi German Patent 1,089,173 mentation, 2% of coagulate 20 sorbitan monostearate from coagulates German Patent 1,089,173 21 reaction product of oleyl alcohol coagulates with 2 moles of ethylene oxide 22 reaction product of tallow fatty coagulates alcohol with 2 moles of ethylene oxide 23 sodium salt of monohexadecylphtha- coagulates late, from German Patent 1,089,173 24 sodium cetyl/stearyl phthalate from coagulates German Patent 1,089,173 25 Lecithin A coagulates 26 Lecithin B coagulates 27 Lecithin C coagulates - EXAMPLE 4 Manufacture of a water-in-oil dispersion of an acrvlamide homopolymer.

The procedure described in Example I is followed, but in addition to the emulsifier to be used according to the invention, 10 parts of a reaction product of nonylphenol with from 8 to 12 moles of ethylene oxide are employed. A coagulatefree. substantially sedimentation-stable water-in-oil polyacrylamide dispersion is obtained.

COMPARATIVE EXAMPLES 28 to 36 Example 4 is repeated, except that instead of the emulsifier to be employed according to the invention, the emulsifiers shown in Table 4 are used. The results obtained are also listed in Table 4. It may be seen from the Table that other than with sorbitan monooleate, coagulate-free water-in-oil polyacrylamide dispersions were not obtainable with any of the emulsifiers of the prior art. However, a disadvantage of the use of sorbitan monooleate is that the dispersion shows extensive sedimentation. The use of the emulsifier to be employed according to the invention on the other hand, gives a coagulate-free and sedimentation-stable dispersion.

TABLE 4 Behavior Stability of the K value of Example Water-in-oil emulsifier polymerization resulting dispersion the polymer 4 oleyl hydroxylalkyl ether of glycerol good, no 231 Comparative sedimentation Examples 28 sorbitan monooleate from good sedimentation 239 German Patent 1,089,173 29 sorbitan monostearate from good solidifies to a German Patent 1,089,173 paste, coagulates 30 reaction product of oleyl alcohol coagulates - with 2 moles of ethylene oxide 31 reaction product of tallow fatty coagulates - alcohol with 2 moles of ethylene oxide 32 sodium salt of monohexadecylphtha- coagulates - late, from German Patent 1,089,173 33 sodium cetyl/stearyl phthalate coagulates - from German Patent 1,089,173 34 Lecithin A coagulates - 35 Lecithin B coagulates - 36 Lecithin C coagulates - - EXAMPLE 5 Manufacture of a water-in-oil dispersion of a copolymer of 35% of acrylamide and 65 n of sodium acrylate.

Example 2 is repeated except that 10 parts of a reaction product of nonylphenol with from 8 to 12 moles of ethylene oxide are added to the emulsifier to be used according to the invention. A coagulate-free, substantially sedimentation-stable water-in-oil polymer dispersion is obtained.

COMPARATIVE EXAMPLES 37 to 45 Example 5 is repeated, but the emulsifier to be used according to the invention is replaced by the water-in-oil emulsifiers of the prior art shown in Table 5. The Table lists the results obtained, in comparison to Example 5. With none of the conventional emulsifiers was it possible to obtain the desired water-in-oil polymer dispersions free from coagulate, whilst, surprisingly, this did prove possible with the emulsifier to be used according to the invention.

TABLE 5 Behavior on Stability of the K value of Example Type of water-in-oil emulsifier polymerization resulting dispersion the polymer 5 oleyl hydroxyalkyl ether good good, slight sedi- 243 of glycerol mentation, free from coagulate Comparative Examples 37 Sorbitan monooleate from good good, slight sedi- 209 German Patent 1,089,173 mentation, 2% of 38 sorbitan monostearate from good coagulates German Patent 1,089,173 39 reaction product of oleyl alcohol coagulates - with 2 moles of ethylene oxide 40 reaction product of tallow fatty coagulates - alcohol with 2 moles of ethylene oxide 41 sodium salt of monohexadecylphtha- coagulates - late, from German Patent 1,089,173 42 sodium cetyl/stearyl phthalate coagulates - from German Patent 1,089,173 43 Lecithin A coagulates - 44 Lecithin B good good, slight sedi- 254 mentation, 1,5% of coagulate 45 Lecithin C coagulates - - The above examples and comparative examples show that only with the aid of the water-in-oil emulsifiers to be used according to the invention is it possible to obtain coagulate-free water-in-oil dispersions in the case of all the three copolymers shown, which differ greatly in their composition. This conclusion applies both to the sole use of the water-in-oil emulsifiers to be used according to the invention and to the manufacture of dispersions carried out in the presence of a wetting agent having a higher HLB value, whereby dispersions which are more stable to sedimentation are obtained.

EXAMPLE 6 Manufacture of a water-in-oil dispersion of an acrylamide homopolymer.

The following components are mixed in a vessel provided with a stirred thermometer and nitrogen inlet and outlet: 344 parts of a mixture of 84% of saturated aliphatic hydrocarbons and 16% of naphthenic hydrocarbons (boiling range of the mixture: 192--254"C) and 56 parts of a reaction product of 1 mole of oleyl glycidyl ether and I mole of glycerol, which has been reacted with 1 mole of ethylene oxide under the conditions described in Example 1 of German Laid-Open Application DOS 2,536,597.

After having thoroughly mixed the components, a solution of 213 parts of acrylamide in 387 parts of water is added and the aqueous phase is emulsified in the hydrocarbon oil. Nitrogen is then passed over the mixture for 30 minutes, after which the mixture is heated to 600C in the course of 15 minutes. At this temperature, a solution of 0.212 part of 2,2'-azo-bis-isobutyronitrile in a little acetone is added. The polymerization has ended after the mixture has been kept at 60"C for 3 hours, whilst stirring. A coagulate-free water-in-oil polymer dispersion is obtained, which in the course of time shows sedimentation of a lower phase which is richer in polymer, but can readily be redispersed by slight agitation of the disp

TABLE 6 Behavior on Stability of the K value of Example Water-in-oil emulsifier polymerization resulting dispersion the polymer 6 Oleyl hydroxyalkyl ether of Good Good, slight 185 glycerol+1 mole of ethylene sedimentation, oxide coagulate-free 7 Oleyl hydroxyalkyl ether of Good Good, sedimen- 201 glycerol+2 moles of ethylene tation, oxide coagulate-free Comparative Examples 46 Sorbitan monooleate from German Coagulates - Patent 1,089,173 47 Sorbitan monostearate from German Coagulates - Patent 1,089,175 48 Reaction product of oleyl alcohol Coagulates - with 2 moles of ethylene oxide 49 Reaction product of tallow fatty Coagulates - alcohol with 2 moles of ethylene oxide 50 Sodium salt of monohexadecyl Coagulates - phthalate, from German Patent 1,089,173 51 Sodium cetyl/stearyl phthalate Coagulates - from German Patent 1,089,173 52 Lecithin A Coagulates - 53 Lecithin B Coagulates - 54 Lecithin C Coagulates - - EXAMPLE 8 Manufacture of a water-in-oil dispersion of a polymer of acrylamide and sodium acrylate.

The following components are mixed in a vessel equipped with a stirred thermometer and nitrogen inlet and outlet: 344 parts of a mixture of 840, of saturated hydrocarbons and 16% of naphthenic hydrocarbons (boiling range of the mixture: 192--254"C) and 52 parts of a reaction product prepared from oleyl glycidyl ether and glycerol which has subsequently been reacted with 1 mole of ethylene oxide (as described in Example 6). A solution of 74 parts of acrylamide and 104 parts of acrylic acid in 363 parts of water, the- pH of which has been brought to 7 with 58 parts of sodium hydroxide, is then added and the aqueous solution is emulsified in the hydrocarbon oil. Nitrogen is then passed over the mixture for 30 minutes, after which the mixture Is heated to bOOC in the course of 15 minutes. At this temperature, a solution of 0.212 part of 2,2'-azo-bis isobutyronitrile in a little acetone is added. The polymerization has ended after the mixture has been stirred for 3 hours at 600 C. A coagulate-free, water-in-oil polymer dispersion is obtained, which in the course of time shows sedimentation of a lower ohase, richer in polymer. The sedimented phase can, however, readily be redispersed by slight agitation of the dispersion.

EXAMPLE 9 Example 8 is repeated except that a reaction product of oleyl glycidyl ether and glycerol, which has been oxyalkylated with 2 moles of ethylene oxide, is used as the water-in-oil emulsifier.

A coagulate-free water-in-oil polymer dispersion is obtained, which sediments slightly in the course of some days. However, the sedimented phase can be redispersed by slight agitation of the dispersion.

COMPARATIVE EXAMPLES 55 to 63 Instead of the emulsifiers to be employed according to the invention (oxyalkylated reaction products of oleyl glycidyl ether and glycerol), conventional water-in-oil emulsifiers are used for the manufacture of water-in-oil dispersions of the acrylamide copolymer. The polymerization conditions correspond to Example 8 and the emulsifiers employed and the results are listed in Table 7. The Table shows that with none of the emulsifiers of the prior art was it possible to obtain water-in-oil polymer dispersions without coagulate, whilst this was possible with the water-in-oil emulsifiers to be employed in accordance with the invention.

TABLE 7 Behavior on Stability of the K value of Example Water-in-oil emulsifiers polymerization resulting dispersion the polymer 8 Oleyl hydroxyalkyl ether of Good Good, 257 glycerol reacted with 1 mole sedimentation of ethylene oxide 9 Oleyl hydroxyalkyl ether of Good Good, 258 glycerol reacted with 2 moles sedimentation of ethylene oxide Comparative Examples 55 Sorbitan monooleate from German Deposit on Sedimentation 227 Patent 1,089,173 walls, large amount of coagulate 56 Sorbitan monostearate from German Coagulates - Patent 1,089,173 57 Reaction product of oleyl alcohol Coagulates - with 2 moles of ethylene oxide 58 Reaction product of tallow fatty Coagulates - alcohol with 2 moles of ethylene oxide 59 Sodium salt of monohexadecyl Coagulates - phthalate, from German Patent 1,089,173 60 Sodium cetyl/stearyl phthalate Good, but 3% Sedimentation from German Patent 1,089,173 of coagulate 61 Lecithin A Coagulates - 62 Lecithin B Coagulates - 63 Lecithin C Coagulates - - EXAMPLE 10 Manufacture of a water-in-oil dispersion of a copolymer of 25% of acrylamide and 75 Ó of acryloxyethyldiethylammonium sulfate.

The following components are mixed in a vessel provided with a stirrer, thermometer and nitrogen inlet and outlet: 344 parts of a mixture of 84 , of saturated aliphatic hydrocarbons and 16% of naphthenic hydrocarbons (boiling range of the mixture: 192--254"C) and 62 parts of a reaction product of oleyl glycidyl ether and glycerol oxyalkylated with I mole of ethylene oxide (as described in Example 6). A solution of 73.5 parts of acrylamide and 171 parts of diethylaminoethyl acrylate in 303 parts of water, the pH of which has been brought to 3 with 52 parts of sulfuric acid, is added to the above mixture. The organic phase is mixed with the aqueous phase, whilst stirring thoroughly, so as to form a waterin-oil emulsion. Nitrogen is then passed over the emulsion for 30 minutes and the emulsion is heated to 600C in the course of 15 minutes. At this temperature, 0.212 part of 2,2'-azo-bis-isobutyronitrile in acetone is added. The polymerization has ended when the temperature of the mixture has been kept at 600C for 3 hours. A coagulate-free water-in-oil dispersion results, which after some time forms a lower phase, richer in polymer, which can however be redispersed by slight agitation of the dispersion.

EXAMPLE 11 Results similar to those described in Example 10 are obtained when a reaction product of oleyl glycidyl ether and glycerol, which has been reacted with 2 moles of ethylene oxide, as described in Example 9 is used as the water-in-oil emulsifier.

COMPARATIVE EXAMPLES 64 to 70 Example 10 is repeated except that instead of the oxyethylated reaction products of oleyl glycidyl ether with glycerol, the same amount of the emulsifiers conventionally employed for the manufacture of water-in-oil dispersions is used.

The emulsifiers employed and the results obtained are summarized in Table 8. As may be seen from the Table, none of the emulsifiers of the prior art permitted the manufacture of coagulate-free water-in-oil polymer dispersions, whilst, surprisingly, the manufacture of such a dispersion proved possible with the emulsifiers employed in Examples 10 and 11.

TABLE 8 Behavior on Stability of the K value of Example Type of water-in-oil emulsifier polymerization resulting dispersion the polymer 10 Oleyl hydroxyalkyl ether of Good Good, sedi- 154 glycerol, reacted with 1 mole mentation of ethylene oxide 11 Oleyl hydroxyalkyl ether of Good Good, sedi- 151 glycerol, reacted with 2 moles mentation of ethylene oxide without coagulate Comparative Examples 64 Sorbitan monooleate from German Mediocre, 142 Patent 1,089,173 sedimentation, 2% of coagulate 65 Sorbitan monostearate from German Coagulates - Patent 1,089,173 66 Reaction product of oleyl alcohol Coagulates - with 2 moles of ethylene oxide 67 Reaction product of tallow fatty Coagulates - alcohol with 2 moles of ethylene oxide 68 Sodium salt of monohexadecyl Coagulates - phthalate, from German Patent 1,089,173 69 Sodium cetyl/stearyl phthalate Coagulates - from German Patent 1,089,173 70 Lecithin A Coagulates - 71 Lecithin B Coagulates - 72 Lecithin C Coagulates - - EXAMPLE 12 Manufacture of a water-in-oil dispersion of an acrylamide homopolymer.

The procedure described in Example 6 is followed, but in addition to the emulsifier to be used according to the invention, 10 parts of a reaction product of nonylphenol with from 8 to 12 moles of ethylene oxide are employed. A coagulatefree. substantially sedimentation-stable water-in-oil polyacrylamide dispersion is obtained.

EXAMPLE 13 The procedure described in Example 7 is followed, but in addition 10 parts of a reaction product of nonylphenol with from 8 to 12 moles of ethylene oxide are employed. A coagulate-free, substantially sedimentation-stable water-in-oil polyacrylamide dispersion is obtained.

COMPARATIVE EXAMPLES 73 to 81 Example 12 is repeated, except that instead of the emulsifier to be employed according to the invention the emulsifiers shown in Table 9 are used. The results obtained are also listed in Table 9. It may be seen from the table that other than with sorbitan monooleate, coagulate-free water-in-oil polyacrylamide dispersions were not obtainable with any of the emulsifiers of the prior art. However, a disadvantage of the use of sorbitan monooleate is that the dispersion shows extensive sedimentation. The use of the emulsifiers to be employed according to the invention, on the other hand, gives coagulate-free and sedimentation-stable dispersions.

TABLE 9 Behavior on Stability of the K value of Example Water-in-oil emulsifier polymerization resulting dispersion the polymer 12 Oleyl hydroxylalkyl ether of Good Good, no 234 glycerol, oxyalkylated with sedimentation 1 mole of ethylene oxide 13 Oleyl hydroxyalkyl ether of Good Good, no 246 glycerol, oxyalkylated with sedimentation 2 mole of ethylene oxide Comparative Examples 73 Sorbitan monooleate from German Good Sedimentation 239 Patent 1,089,173 74 Sorbitan monostearate from German Good Solidifies to Patent 1,089,173 75 Reaction product of oleyl alcohol Coagulates - with 2 moles of ethylene oxide 76 Reaction product of tallow fatty Coagulates - alcohol with 2 moles of ethylene oxide 77 Sodium salt of monohexadecyl Coagulates - phthalate, from German Patent 1,089,173 78 Sodium cetyl/stearyl phthalate Coagulates - from German Patent 1,089,173 79 Lecithin A Coagulates - 80 Lecithin B Coagulates - 81 Lecithin C Coagulates - - EXAMPLE 14 Manufacture of a water-in-oil dispersion of a copolymer of 35 ,', of acrylamide and 65 n of sodium acrylate.

Example 8 is repeated except that 10 parts of a reaction product of nonylphenol with from 8 to 12 moles of ethylene oxide are added to the emulsifier to be used according to the invention. A coagulate-free, substantially sedimentation-stable water-in-oil polymer dispersion is then obtained.

EXAMPLE 15 Example 9 is repeated except that the polymerization is carried out in the additional presence of 10 parts of a reaction product of nonylphenol with from 8 to 12 moles of ethylene oxide. A coagulate-free, substantially sedimentation-stable water-in-oil dispersion is obtained.

COMPARATIVE EXAMPLES 82 to 90 Example 14 is repeated, except that the emulsifier to be employed according to the invention is replaced by the water-in-oil emulsifiers of the prior art, shown in Table 10. The Table lists the results obtained, in comparison to Examples 14 and 15.

With none of the conventional emulsifiers was it possible to obtain the desired water-in-oil polymer dispersions free from coagulate, whilst, surprisingly, this did prove possible with the emulsifiers to be used according to the invention.

TABLE 10 Behavior on Stability of the K value of Example Type of water-in-oil emulsifier polymerization resulting dispersion the polymer 14 Oleyl hydroxyalkyl ether of Good Good, slight 241 glycerol, reacted with 1 mole of ethylene oxide 15 Oleyl hydroxyalkyl ether of Good Good, substan- 252 glycerol, reacted with 2 moles tially of ethylene oxide sedimentationstable, coagulate-free Comparative Example 82 Sorbitan monooleate from German Good Good, slight 209 Patent 1,089,173 sedimentation, 2% of coagulate 83 Sorbitan monostearate from German Good Coagulates Patent 1,089,173 84 Reaction product of oleyl alcohol Coagulates - with 2 moles of ethylene oxide 85 Reaction product of tallow fatty Coagulates - alcohol with 2 moles of ethylene oxide 86 Sodium salt of monohexadecyl Coagulates - phthalate, from German Patent 1,089,173 87 Sodium cetyl/stearyl phthalate Coagulates - from German Patent 1,089,173 88 Lecithin A Coagulates - 89 Lecithin B Good Good, slight 254 sedimentation, 1.5% of coagulate 90 Lecithin C Coagulates - - The above Examples and Comparative Examples show that only with the aid of the water-in-oil emulsifiers to be used according to the invention is it possible to obtain coagulate-free water-in-oil dispersions in the case of all the three copolymers shown, which differ greatly in their composition. This conclusion applies both to the sole use of the water-in-oil emulsifiers to be used according to the invention and to the manufacture of dispersions carried out in the presence of a wetting agent having a higher HLB value, whereby dispersions which are more stable to sedimentation are obtained.

Claims

WHAT WE CLAIM IS: 1. A process for the manufacture of a sedimentation-stable water-in-oil dispersion of an acrylamide polymer by polymerizing a water-in-oil emulsion of an aqueous acrylamide solution, which may or may not contain one or more other water-soluble ethylenically unsaturated monomers, in a hydrophobic organic dispersion medium in the presence of a polymerization initiator and an emulsifier. wherein the water-in-oil emulsifier used is a compound which is obtained by reacting one or more saturated or unsaturated fatty alcohols of 10 to 22 carbon atoms with epichlorohydrin in a molar ratio of from 1:0.5 to 1:

1.5 to give a glycidyl ether and reacting the latter with a polyhydric alcohol of 2 to 6 carbon atoms, which contains from 2 to 6 hydroxyl groups, or a monoether thereof with a fatty alcohol of 10 to 22 carbon atoms, in a molar ratio of glycidyl ether to alcohol of from 1:0.5 to 1:6.0, in the presence of an acid or a base.

2. A process as claimed in Claim 1, wherein the water-in-oil emulsifier used is a compound which has been obtained as defined in Claim 1 and then oxyalkylated with from I to 6 moles of one or more alkylene oxides of 2 to 4 carbon atoms.

3. A process as claimed in Claim 1 or 2, wherein, in the production of the water-in-oil emulsifier, the glycidyl ether and its reaction product with the polyhydric alcohol or monoether thereof are produced in a one-step reaction in which the fatty alcohol(s) and epichlorohydrin and the polyhydric alcohol or monoether thereof are reacted conjointly in the presence of an acid catalyst and then a basic catalyst.

4. A process as claimed in Claim 1 or 2, wherein, in the production of the water-in-oil emulsifier, the glycidyl ether is formed first but is not isolated and instead the polyhydric alcohol or monoether thereof is added to the reaction mixture and the further reaction carried out in the same reaction vessel.

5. A process as claimed in any of Claims 1 to 4, wherein the fatty alcohol(s) and epichlorohydrin are reacted in substantially equimolar amounts in the manufacture of the emulsifier.

6. A process as claimed in any of Claims I to 5, wherein in the manufacture of the emulsifier the glycidyl ether is reacted with the polyhydric alcohol or monoether thereof in the presence of an acid catalyst at 50 to sOOC.

7. A process as claimed in any of Claims I to 5, wherein in the manufacture of the emulsifier the glycidyl ether is reacted with the polyhydric alcohol or monoether thereof in the presence of an alkaline catalyst at 150 to 2200 C.

8. A process as claimed in Claim 2 or Claim 2 and any of Claims 3 to 7, wherein the emulsifier used has been oxyalkylated with I to 3 moles of ethylene oxide, I or 2 moles of propylene oxide or 1 mole of butylene oxide.

9. A process as claimed in any of Claims 1 to 8, wherein the acrylamide is polymerized with a water-soluble ethylenically unsaturated comonomer in an amount to provide 2 to 75% by weight of comonomer in the copolymer.

10. A process as claimed in any of Claims 1 to 9, wherein the hydrophobic organic dispersion medium is a mixture of saturated hydrocarbons containing up to 20% by weight of naphthenes and having a boiling range of 192 to 2540C.

11. A process as claimed in any of Claims 1 to 10, wherein a wetting agent having a HLB value greater than 10 is also present during the manufacture of the dispersion.

12. A process for the manufacture of a sedimentation-stable water-in-oil dispersion of an acrylamide polymer carried out substantially as described in any of the foregoing Examples 1 to 15.

13. Sedimentation-stable water-in-oil dispersions of an acrylamide polymer when manufactured by a process as claimed in any of Claims I to 12.

14. A flocculation assistant for clarifying aqueous systems or for use in the manufacture of paper or treatment of sewage, a disposing agent and protective colloid for drilling muds or an assistant in the secondary production of petroleum from flooding waters when obtained bv dilution of a dispersion claimed in Claim 13 with water.