NZ201009A - Water-soluble polymers of di-c1-3alkylaminoneopentyl(meth)acrylates - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £01 009 2Q1flO Priority Date(s): \ t 5~. tV.®'...

Corr.piste Specification F:!ed:'fv~fv^r^ Class: fP. I3, ff?J. ?5?{ tf£i&.'sCc>_ 3*(=i)r4, Publication Date: 3.) .^^.13,85 P.O. Journal, Pic; NEW ZEALAND PATENTS ACT 19 53 COMPLETE SPECIFICATION "Water-soluble polymers of di-C -C_-alkylamino-neopentyl (meth) acrylates and their preparation" -i-VTE BASF Aktiengesellschaft, a German Joint Company organised and existing under the laws of the Federal Republic of Germany with a registered office at 6700 Ludwigshafen, Federal Republic of Germany hereby declare the invention, for which -I-/we pray that a patent may be granted to ffte/us, ,and the method by which it is to be performed, to be particularly described in and by the following statement:- (foffowed by p*ge 1 A.) tA o.z. 0050/35212/35^0^0 | QQ^ Water-soluble polymers of di-O^-C^-alkylamino-neopentyl (meth)acrylates and their preparation Gorman Patent 0)130)600 dioolooco1 A process for the preparation of sedimentation-stable water-in-oi"l dispersions of acrylamide polymers is known in which a water-in-oil emulsion of^an aqueous acrylamide solution, which may contain not more than 50% by weight of other water-soluble, ethylenically unsaturated monomers, is polymerized in a hydrophobic organic dispersion medium in the presence of a water-in-oil emulsifier, of from 0.1 to 10% by weight of a wetting agent having an HLB value greater than 10, and of a 10 polymerisation initiator. Other suitable water-soluble, ethylenically unsaturated monomers include aminoalcohol esters of acrylic acid or methacrylic acid. The known co polymers arej inter alia, used in papermaking for increasing the retention, drainage rate and flocculation rate. However, the effects which can be achieved with these copolymers are still in need of improvement.

Gorman Laid Open Application D0D £,03^,000 Jiis oloooo Emulsion polymers containing (a) from 5 to 100% by 20 weight of a dialkylaminoneopentyl ester of an ethylenically unsaturated polymerizable carboxylic acid and (b) from 0 to 95% by weight of a water-insoluble or at most slightly water-soluble comonomer, (a) and (b) totaling not less than 90% by weight of the polymer, the remainder of ^C^iich can be-built up from water-soluble canoncmer have also been described. |se emulsion polymers are in the form of an aqueous ais- si on, and are used as thickeners for aqueous systems having p r. 2 0 10 09 - 2 - O.Z. 00-j0/]>5212/j)^u0 a pH of less than 7. -Where water-soluble dialkylaminoalkyl (meth)acrylate-containing polymers have hitherto been used as flocculants, their effectiveness decreases fairly rapidly if they are in the form of an aqueous solution, and after prolonged storage they become virtually ineffective as floqculants.

It is an object of the present invention to provide water-soluble polymers which, when used as paper assistants, give better retention, drainage rate and 10 flocculation than the conventional acrylamide copolymers, and at the same time are effective flocculants -for waste • water and sludge. - We have found that this object is achieved, according to the present invention, by water-soluble homo-polymers of neutralized or quaternized di-C^-C^-alkyl-aminoneopentyl (meth)acrylates, and copolymers which contain not less than 5% by weight of neutralized or quaternized di-C^-Cg-alkylaminoneopentyl (meth)acrylate as co-polymerized units, the homopolymers and copolymers having 20 a K value of from 150 to 300. These tiOmO- a rig- copolymers are added to the papermaking stock, and give unexpectedly higher retention, drainage rate and flocculation rate than comparable conventional polymers. Aqueous solutions of the copolymers according to the invention, which are used as flocculants for waste v/ater and sludge, can be stored for a prolonged period without a noticeable drop in flocculation activity.

The homopolymers and copolymers can be prepared n a i n n Q - 3 - O.Z. 0050/35212/35^00 in a conventional manner by polymerization of the monomers, for example by polymerization in a water-in-oil emulsion ■oy proooco diooloood in Gormen Patent 1,000,173 or by a reverse suspension polymerization process diooloood" v in Carman Patient 1^^81)33.8, or by solution polymerization in water or precipitation polymerization in an inert organic solvent. All the processes use the conventional polymerization initiators, eg. peroxides, redox catalysts or azo-bis-isobutyronitrile. Homopolymers are pre- pared by polymerization of neutralized or quaternized di-C-j-C^-alkylaminoneopentyl (meth)aerylates (hereinafter referred to as monomers of group (a)) in the absence of other monomers. Copolymers of di-C^-C^-alkylaminoneo-pentyl acrylates cr of di-C^-C^-alkylaminoneopentyl methacrylates contain not less than 5% by weight, preferably frorr. 20 to 80% by weight, of these monomers as copolymerized units. C-j-C^-Alkyl is methyl, ethyl, n-propyl or isopropyl. The monomers of group (a) may be copolymerized with monomers of groups(b) and (c). Preferred comonomers of group (b) in-20 elude acrylamide, methacrylamide and aminoalcohol esters c-f acrylic acid or methacrylic acid, eg. dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminopropyl acrylate, diethylamino-propyl methacrylate and dimethylaminobutyl acrylate. The aminoalcohol esters of acrylic acid or mfeth-acrylic acid and the di-C^C^alkylaminoneopentyl (meth)-acrylates are always polymerized in neutralized or quater-^i-iT nized form. Examples of suitable quaternizing agents /y ^ ■ £f .o^fc^ire alkyl halides, eg. methyl chloride, ethyl chloride, 30 o#nethyl bromide, ethyl bromide, methyl iodide, propyl $ £} (p ■ 201009 - 4 - Q-rg-r 0030/35212/35'100 chloride and butyl chloride, dimethyl sulfate, diethyl sulfate, lauryl chloride, alkylene oxides, such as ethylene oxide and propylene oxide, hydroxyalkyl halides, epi-halohydrins, such as epichlorohydrin and epibromohydrin, and benzyl chloride.

Inorganic and organic acids which form salts with the basic monomers, for example sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, formic acid and adipic acid, can be used for the neutralization. 10 Other comonomers of group (b) include- ethylenically unsaturated carboxylic acids of 3 to 5 carbon atoms, eg. acrylic acid, methacrylic acid, crotonic acid, itaconic acid and fumaric acid, maleic anhydride and acid monomers, such c.s vinylbenzenesulfonic acid, acrylamidopropane-sulfonic acid and vinylsulfonic acid and their alkali metal or ammonium salts.

The copolymers can be modified by the presence of, as copolymerized units, not more than about 20% by weight of monomers of group (c) , the percentages by weight of (a), (b) and (c) always total-20 ing 100. Monomers of this group are acrylates and methacrylates of monohydric alcohols of 1 to 12 carbon atoms, acrylonitrile, methacrylonitrile, vinyl esters, eg. vinyl acetate, vinyl propionate and vinylbutyrate, diisobutylene and styrene.

The homopolymers of dimethylaminoneopentyl acrylate, and copolymers containing, as copolymerized units, from 20 to 80% by weight of dimethylaminoneopentyl acrylate and from 80 to 20% by weight of acrylamide, methacryl-amide or dialkylaminoalky1 acrylate or methacrylate are of 7 010 0 - 5 - fr:Z. 0050/^5212/35^00-particular importance in the paper industry. All or some of the acrylamide or methacrylamide in the copolymers can be replaced by the above basic acrylates, eg. diethyl-aminoethyl acrylate.

Copolymers containing, as copolymerized units, from 20 to 95% by weight of. neutralized or quaternized di-C^-C^-alkyl-aminoneopentyl acrylate and, as the comonomer, from 5 to 80% by weight of amides of ethylenically unsaturated C^-C^-carboxylic acids, di-C^-C^-alkylamino-10 C^-C^-alkyl acrylates or methacrylates and/or di-C^-Cg-alkylamino-C2-C4-alkylene(meth)acrylamides are preferably used as flocculants for waste water and sludge. Examples of comonoraers of the above type are acrylamide, methacrylamide and aminoalcohol esters of acrylic acid and methacrylic acid, eg. dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, diethylaminopropyl acrylate, diethylaminopropyl methacrylate and dimethyl-aminobutyl acrylate. Examples of dialkylaminoalkylene (meth)acrylamides are compounds of the formula R2 CHo=C-C0-NH (CH„ ) -N< 2 . -i 2 n \ q R RJ 1 2 3 where R is H or CH^, R and R are C^-C^-alkyl and n is from 2 to 4. Examples of compounds of this type are N,N-dimethylaminopropylacrylamide, N,N-dimethylaminopropyl- methacrylamide and N,N-diethylaminobutylacrylamide.

The polymerization temperature depends on the particular polymerization initiator used, and can vary 201009 - 6 - O.Z. 0050/35212/35^00 within a wide range, for example from 0 to 120°C. As a rule, the polymerization is carried out under atmospheric pressure and at from 20 to 80°C, care being taken that the components are mixed thoroughly. The monomers are virtually completely polymerized. The main poly merization can be followed by post-polymerization in order as far as possible to reduce the residual monomer content of the polymer.

The polymers preferably have molecular weights 10 above 1 million, and they are more closely defined by their Fikentscher K value, which is from 150 to 300, preferably from 170 to 250. The high molecular weight polymers in particular can be used in papermaking as retention agents, drainage agents and flocculants. For this purpose, from 0.005 to 0.5% by weight, preferably from 0.01 to 0.1% by weight, based on the dry fiber, of a copolymer containing the di-C^-C^-alkylamino-neopentyl (meth)acrylate is added to the pulp. The di-C^-C^-alkylaminoneopentyl(meth)acrylates are effective in 20 weakly alkaline, neutral and acid pulp. They can be used in either non-ligneous or ligneous pulps, and are particularly effective retention agents for chalk and kaolin.

The high molecular weight water-soluble homopolymers and copolymers are also used as flocculants for waste water and sludge. The waste water can originate from municipal sewage plants or industrial water treatment 'v* Qp&ants, in which case the homopolymers and copolymers used to treat the waste wa-t'er. However, they can also be 2.0 1 0,0 05t^3j2r2/3W& - 7 - : 2/' J3 £"o used for flocculation of sludge from municipal sewage plants and of activated sludge from industrial waste water treatment plants. From 100 to 350 g of flocculant per m3 of sludge are used. For the treatment of waste water, from 1 to 20 g of flocculant are used per m3 of waste water. The homopolymers or copolymers which contain neutralized or quaternized di-C1-C„-alkylarninoneo 1 O pentyl(meth)acrylate as copolymerized units and which are used according to the invention have a more powerful flocculating effect than the conventional cationic flocculants, as is shown by the fact that maximum flocculation is achieved with a smaller amount of flocculant. In contrast to aqueous solutions of conventional cationic polymers, aqueous solutions of polymers containing dialkylaminoneo-pentyl (meth)acrylate retain their activity as flocculants, ie. the activity of the aqueous polymer solutions is i highly stable, so that, once prepared, polymer solutions do not have to.be used immediately but can be stored for a prolonged period before being used as flocculants. in the Examples, parts and percentages are by weight. The K values of the polymers are measured in % strength aqueous sodium chloride solution at 25°C by the method of H. Fikentscher, Cellulosechemie 1_3 (1932), 58 - 64 and 71 - 74; K = k . 103.

Preparation of the polymers I. Preparation of water-in-oil polymer emulsions General Method 220 parts of a mixture of 84% of saturated aliphatic hydrocarbons and 16% of naphthenic hydrocarbons 201009 - 8 - O.Z. 0050/35212/35^00 (boiling range from .192 to 254°C), 35 parts of the reaction product of 1 mole of oleyl glycidyl ether, 1 mole of glycerol and 2 moles of ethylene oxide, and 6 parts of an adduct of 10 moles of .ethylene oxide with 1 mole of nonyl-phenol were mixed in a vessel equipped with a stirrer, thermometer and nitrogen inlet and outlet.

"N The aqueous monomer phase having the particular composition shown in Table 1 was stirred into this mixture. Nitrogen was passed through the emulsion for 30 minutes, 10 and the emulsion was then heated to 50°C in the course of 15 minutes. A solution of 0.15 part of 2,2'-azo-bis- isobutyronitrile in a little acetone was then added, and the temperature v/as kept at from 60 to 65°C for 2 hours. The same amount of polymerization initiator was then again added and the mixture was post-polymerized at 65°C for 2 hours. A coagulate-free and sedimentation-stable water-in-oil polymer emulsion v/as obtained.

The resulting v/ater-in-oil polymer emulsions were 20 used to prepare aqueous polymer solutions by the method disclosed in N.Z. Patent 165197 by adding to the emulsions 2% of a nonylphenol which had been reacted v/ith ethylene oxide in a molar ratio of 10:1 and diluting the mixtures with water to a polymer content of 0.25%. 7 0 10 ft f; - 9 - Qt2. 00^0/^21 £/-3§400 TABLE 1 a) Monomer phase of the water-in-oil emulsions 1 2 3 4_ 5 6 distilled water [gl 369 369 369 369 369 369 369 acrylamide 195 195 195 195 195 195 195 37.5% strength sulfuric acid 60 60 60 60 60 60 60 diethylaminoethyl acrylate [«3 83 74.7 58 .1 41 .5 24.9 8.3 - dimethylamino- neopentyl acrylate 1*1 - 8.3 24, .9 41 .5 58.1 74.7 83 formic acid [s] 0.15 0.15 0 .15 0 .15 0.15 0.15 0.15 b) Composition of the polymers : in % 1/1 1/2 1/3 1/4 1/5 1/6 1/7 acrylamide 70 70 70 70 70 70 70 diethylaminoethyl acrylate 27 21 9 3 0 dimethylamino-neopentyl acrylate"1" 0 3 9 21 27 K value 197 247 201 217 221 235 216 Polymer 1/1 = comparative prior art polymer 0 CH_ CH_ , . " i -J ^ i +)• CHp = CH - C-0 - CHL - C - CH„ - N ch3 ck3 II Pulverulent copolymers Polymer II/l is a commercially available pulverulent copolymer of 60% of acrylamide and 40% of diethylaminoethyl acrylate-sulfate and has a K value of 195. 201009 _ 10 - c.z. 0O5O/55S12/35WO Polymer II/2 was prepared as follows: 114 g of dimethylaminoneopentyl acrylate-sulfate, 170 g of acrylamide and 1 g of formic acid in 280 g of water were brought to pH 3 with sulfuric acid, and 0.57 g of 2,2'-azo-bis-(N,N'-dimethyleneisobutyramidine) dihydro-chloride v/as added. The solution was introduced into a reservoir of 1.6 1 of cyclohexane and 5.5 g of protective colloid A from Gorman Laid Open Application DOC■ 21710 i 372 at 60°C in the course of one hour (protective 10 colloid A was obtained by reacting dicyclopentadiene maleic anhydride and styrene in an autoclave at 267°C, letting down the mixture and distilling off the volatile constituents)- After a further hour at 60°C and azeo- tropic removal of the water, a polymer having a K value of 206 (0.1% strength in 5% strength aqueous sodium chloride solution) was obtained.

III. Preparation of water-in-oil polymer emulsions (General Method) The components of the oil phase whose composition is given in Table 2 were mixed in a vessel equipped with a stirrer, thermometer and nitrogen inlet and outlet. 20 The aqueous monomer phase (for the composition, cf. also Table 2) v/as stirred into this mixture. Nitrogen v/as passed through the emulsion for 30 minutes, and the emulsion was then heated to 60°C in the course of 15 minutes. A solution of the initiator (for the type and amount, cf.

Table 2) in a little acetone was added at this temperature, and the mixture was kept at from 60 to 65°C for 2 - 11 - -Q-r£rr-e050/jj212/35403 then again added and the reaction mixture was post-polymerized at 65°C for 2 hours. A coagulate-free and sedimentation-stable water-in-oil polymer emulsion was obtained.

TABLE 2 Composition of the water-in-oil emulsions for the preparation of the polymers III/l III/A III/2 III/B 1) Oil phase Hydrocarbon mixture (boiling range 192-254° C) Emulsifier aooording to Corman Laid Opori Applioation' [g] 200 200 220 220 000 2,05*7, 324f 1 tg] 40 40 Reaction product of 1 mole of nonylphenol and 10 moles of ethylene oxide tg] 7.5 7.5 6 6 i i-1 i\) l Monomer phase distilled water tgl 225 227 369 369 O • • acrylamide tgl 40 40 190 195 37.5% strength sulfuric acid tgl 203 205 61 60 O o diethylaminoethyl acrylate tgl 83 o "V, vjr Ul ro dimethylaminoneopentyl acrylate tg] 284 formic acid tgl - - 0. 0. ro VJI UI -1^ o o 2,2'-azo-bis-isobutyronitrile tg] 2x0. 2 2x0. 2 2x0. 2x0. 1)-Mixture of 84% of saturated aliphatic and 16% of naphthenic hydrocarbons 2) Reaction product of 1 mole of oleyl glycidyl ether, 1 mole of glycerol and 2 moles of ethylene oxide ro o o o v£> • I • o ^ # TABLE 3 Characterization of the polymers III/l III/A III/2 III/B Polymer content of the emulsion 1 [%] 40 40 Composition of the polymer Acrylamide (% by weight] 63 65 Diethylaminoethyl acrylate 1% by weight] Dime thylaniinoneopentyl acrylate [% by weight] 90 K value 180 134 216 197 CO i <t> M o r i O c M VjJ ui ro i—■ ro UT o o O 201009 .. 1 - 14 - o.z. 0050/35212/35400 To test the effectiveness of the above polymers, aqueous polymer solutions were prepared from the water-in-oil polymer emulsions by the process disclosed inN.Z.

Patent 165197. For this, the emulsions were stirred into water containing 2%, based on the polymer emulsion, of nonylphenol which had been reacted with 10 moles of ethylene oxide. Water was then added in an amount such that the polymer content was 0.1%. These 0.1% strength aqueous polymer solutions were used in Examples 9 and 10. 10 of the polymers EXAMPLE 1 The effectiveness of the polymer 1/7 as a paper assistant in comparison with the prior art polymer 1/1 was tested by reference to the Schopper-Riegler freeness and the drainage time.

A ligneous newsprint stock with a pH of 4.8, an alum content of 1.5%, a consistency of 0.2% and a kaolin content of about 12% was used for the Schopper-Riegler freeness test. The drainage time was determined by recording the time required for 700 ml of the stock des-20 cribed above to pass through the Schopper-Riegler apparatus. The drainage time of the assistant-free stock was 97 seconds, and the freeness was 59°SR. These determinations were then carried out on this model stock to which various amounts of polymers 1/1 and 1/7 had been added. The amounts of the polymers ana the results obtained are summarized in Table 4.

TABLE 4 Amount added % Drainage time (seconds) Freeness (°SR) 0.006 0.012 0.024 0.006 0.012 0^024, Polymer I/l 72.4 63.4 55.0 51 47 44 Polymer 1/7 63.4 53.0 41.4 48 43 37 ? 0 1 o o _ 16 - O'Z. 0050/55212/55■'!00 EXAMPLE 2 Sheets of paper with a weight per unit area of about 70 g/m2 were produced from a neutral stock,comprising 100 parts of sulfate pulp and 50 parts of chalk and having a consistency of 0.2%, v/ith the aid of a Rapid-Ktithen sheet-forming apparatus. In the case of the assistant-free stock, the chalk content of the paper was 3.2%. The chalk content of the paper was in each case determined by ashing the sheets. The effectiveness of the polymer 1/7 as a retention agent was compared with that of the conventional retention agent polymer I/l. The amounts of the polymers used, based on the dry stock, and the results obtained are summarized in Table 5.

TABLE 5 Polymer Chalk content when 0.012% 0.024% of retention agent,based on the dry stock, is added I/l ' 13.2% 17.1% 1/7 18.4% 21.1% EXAMPLE 3 The drainage rate achieved by the polymers given in Table 1 was tested on a model stock with the aid of a Schopper-Riegler apparatus. Ligneous newsprint stock with a pH of 4.8, an alum content of 1.5% and a kaolin content of about 12% was used as the model stock.

When no assistant v/as added to the stock, the drainage time v/as 95.1 seconds. The drainage times obtained with different amounts, based on the dry stock, of the 7 0^0 frT-gr-dO;3 0/35 £ 12/33400 polymers described in Table 1 are given in Table 6.

TABLE 6 Polymer Drainage time (seconds) when 0.006% 0.012% 0.024% of polymer, based on the dry stock, is added I/l 79 , .7 73, .1 68. .1 1/2 70, .7 64. .0 55, .9 1/3 68, .5 60, .0 49, .1 1/4 64. ,1 52. .7 44, ,2 1/5 61 , .1 51, .0 42, ,0 1/6 62. .4 52. .0 43, ,0 1/7 67, ,0 54. ,4 44, .6 EXAMPLE 4 Paper having a weight per unit area of about 35 g/m2 was produced, without using a retention agent, on a pilot paper machine with a wire width of 80 cm at a constant rate of 80 m/minute from a non-ligneous stock comprising 60 parts of pine sulfate pulp, 40 parts of beech sulfate pulp and 50 parts of chalk. The effect of polymers I/l and 1/7 was then tested. The results are summarized in Table 7. • % • 4 ) • Polymer Amount added (g/hour) TABLE 7 Weight per unit area (g/m2 ) Chalk content (%) Production (kg/hour) Polymer consumption (g/tonne) - 86.4 9.4 307 - I/l (comparison) 75 95.7 21.5 367 204 1/7 (according to the invention) 75 101.5 .1 390 192 Percentage difference between I/l and 1/7 0 +6 + 16 +6 -6 *>01009 - 19 - o.z. 00j0/3jgig/X^00 EXAMPLE 5 The drainage-accelerating effect of the pulverulent polymers II/l (comparison) and II/2 (according to the invention) on a ligneous neutral newsprint stock having a density of 0.2% v/as determined following the instructions given in Example 1 for determining the drainage time.

When no drainage assistant was used, a drainage time of 115 seconds v/as recorded for this model stock. The drainage times given below were measured when the amounts of polymers II/l and 11/1 given in Table 8 were used: TABLE 8 Polymer Drainage time (seconds) when 0.01% 0.02% 0.04% of polymer, based on the dry stock, was added II/l (comparison) 83.6 70.3 54.4 II/2 (according to the invention) 78.3 57. 9 42.3 EXAMPLE 6 Example 5 was carried out using a ligneous newsprint stock with a pH of 4.5, an alum content of 1.5% and a consistency of 0.2%. When no drainage assistant was used, the drainage time was 105.3 seconds. The drainage times for polymers II/l and II/2 are given in Table 9. 0 * 0 - 20 - O.z. 0030/35212/35J+00 TABLE 9 Polymer Drainage time (seconds) v/hen 0.01% 0.02% 0.04% of polymer, based on the dry stock, was added II/l 71.4 64.9 54.8 II/2 56.5 47.1 36.3 EXAMPLE 7 Sheets of paper having a weight per unit area of about 65 g/m2 were produced from a stock comprising 80% of bleached sulfite pulp and 20% of kaolin and having a pH of 4.8 and an alum content of 1.5%?v/ith the aid of a Rapid-KOthen sheet-forming apparatus. The ash content of the sheets of paper obtained in the absence of a retention agent v/as 5.3%. The ash contents given in Table 10 were found v/hen the prior art polymer II/l and the polymer II/2 according to the invention were used.

TABLE 10 Polymer Ash contents (%) when 0.01% 0.02% 0.09% of retention agent, based on the dry stock, was added II/l 9.8 11.7 12.9 II/2 . 6 12.7 14. 1 EXAMPLE 8 The flocculating effect of the polymers was determined by treating a stock, which had ahigh content of finely divided solids and contained 1 g of sulfite pulp and 0.25 g of kaolin'per liter with various amounts of polymer ">01009 - 21 - O.Z. 0050/35212/^5400 11/1 and II/2. The suspension was stirred and allowed to settle, and the transparency of the supernatant clear water was determined photometrically in each case. The results are summarized in the Table.

TABLE 11 pH about 7 6/0.5% of alum amounts added (ppm) 0. 0.5 0.125 0. 25 transparency (%) II/l 61 72 43 65 II/2 75 80 64 80 no flocculant 32 Test methods a) Determination of the flocculation number 750 ml of waste water or sludge are heated with defined amounts of a 0.1% strength aqueous flocculating solution in a 1 1 measuring cylinder. Flocculation occurs virtually instantaneously. The contents of the measuring cylinder are then emptied into a BUchner funnel and filtered. The flocculation is evaluated visually with the aid of the filter.

Flocculation number 1 = no visible flocculation Flocculation number 2 = slight flocculation Flocculation number 3 = average flocculation Flocculation number 4 = good flocculation, sufficient for practical purposes Flocculation number 5 = very good,optimum flocculation 2 0'"^ 0 - - 22 - Q-.Z. 0050/35212/33400 b) Flocculation activity In this test, the amount of flocculant which must be added to waste water or sludge to achieve optimum flocculation (flocculation number = 5) is determined, also in a 1 1 measuring cylinder.

EXAMPLE 9 The flocculation activity of polymer III/l and polymer III/A (comparison) was determined on digested sludge from a municipal sewage'plant by the method described above under b). The optimum amount of polymer III/l for flocculation was 250 mg/1 of sludge, while the 10 amount of polymer III/A which had to be used was 350 mg/1 of sludge. Accordingly, polymer III/l is distinctly more effective than the prior art polymer III/A.

EXAMPLE 10 0.1% strength aqueous solutions of polymer III/2 and polymer III/B were kept at 23°C for up to 24 hours. The flocculation number of the aqueous polymer solutions was determined after specific intervals of time, which are shown in Table 12. The results are summarized in Table 12. The flocculation number was determined with the aid of digested sludge from a municipal sewage plant.

TABLE 12 Flocculation number after 0 14 7 24 hours 200 mg of polymer 2/1 5 5 5 5 4 250 mg of polymer B/l 5 5 4 3-4 2 From the Table, it can be seen that the aqueous solution of the polymer III/2 used according to the

Claims (9)

0*009 - 23 - -0.2. 0050/35212/25400 invention is substantially more stable than that of the conventional flocculant, polymer III/B. • ■ 201009 - 24 WHAT J/VVE CLAIM IS> compound selected fran the group comprising a

1. A/water-soluble homopolymer of a neutralized or quaternized di-C^-Cg-alkyiaminoneopentyl (meth)aerylate, and a copolymer which contains not less than 5% by weight of neutralized or quaternized di-C1 -C„-alkyl- X o aminoneopentyl (meth)acrylate as copolymerized units, the homopolymers and copolymers having a K value of from 150 to 300.

2. A process for the preparation of a homopolymer or copolymer claimed in claim 1, wherein (a) a neutralized or quaternized di-C.-C_-alkylaminoneopentyl (meth)acrylate is polymerized, X o where relevant as a mixture with (b) not more than 95% by weight, based on the mixture, of other water-soluble, co-polymerizable ethylenically unsaturated monomers, using a polymerization initiator.

3. A process as claimed in claim 2, wherein a mixture of (a) from 20 to 95% by weight of neutralized or quaternized di-C-j-C^-alkylaminoneopentyl (meth)acrylate and, as a water-soluble comonomer, (b) from 5 to 80% by weight of an amide of an ethylenically unsaturated C3-C5-carboxylic acid, a di-C-j-Cg-alkyl-amino-C2-C4-alkyl acrylate or methacrylate or a di-C^-C^ alkylamino-Cg-C^-alkylene (meth)acrylamide, or an ethylenically unsaturated C^-C^-mono- or -di-carboxylic acid, maleic anhydride, vinylsulfonic acid, vinylbenzenesulfonic acid, acrylamidopropanesulfonic acid or an alkali metal or ammonium salt, of the above carboxylic acids, cuz. 0030/332i£/55^co 201 00 is used for the polymerization.

4. A process as claimed in claim 3, wherein the monomer mixture used in the polymerization additionally contains, as a monomer of group (c), not more than 20% by weight of an acrylate or methacrylate of a monohydric C1-C12-alcohol, acrylonitrile, methacrylonitrile, a vinyl ester of a saturated C^-C^-carboxylic acid, diisobutylene or styrene.

5. A process for the manufacture of paper, wherein a homopolymer or copolymer as claimed in claim 1 is added to the stock as a retention agent, drainage agent or flocculant.

6. A process for flocculating waste water and sludge, wherein a homopolymer or copolymer as claimed in claim 1 is used as the flocculant.

7. Paper manufactured according to the process of claim 5. according to claim 1

8. Water soluble homo- and copolymers/substantially as specifically described herein with reference to any one of the Examples. any one of claims 2-4

9. A process for the preparation of a polymer according to/substantially as specifically described herein with reference to any one of the Examples.