NL8203877A - QUATERARY AMMONIUM ENTPOLYMERS. - Google Patents

Description

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Ammonium ammonium graft polymers.

The invention relates to a novel cationic graft copolymer and its use as flocculants, dry strength additives of paper and cling retention agents. More particularly, the invention relates to quaternary ammonium graft copolymers prepared by graft polymerizing water-soluble vinyl monomers into quaternary ammonium polymers. The invention relates to flocculation of the suspended substance by the aforementioned polymers and to papers with improved strength and dye retention prepared by using the aforementioned polymers.

A number of methods are known for the preparation of graft copolymers. These include radiation methods, both high energy radiation from gamma rays or electron accelerators and actinic, ie photochemical radiation. Chemical catalysts also used include free radical initiator systems such as the ferrous ion hydrogen peroxide reaction, which is very effective in promoting graft polymerization.

The invention is not limited to a single method of initiating the polymerization. However, the cerion ion initiating system known from U.S. Pat. No. 2,923,768 is particularly attractive. It is believed that in these methods ceri ions react directly with a pendant reactive group, such as a hydroxyl group, on the polymeric substrate. The radical resulting from this initial reaction can then react with vinyl monomers present in the solution to form a graft copolymer.

Relatively little homopolymer is used in this method 8203877 -2-

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* formed, unless large amounts of chain transfer agents are added.

It has now been found that certain polycwaternary ammonium polymers of the ionic type are active substrates for graft polymerizations. Graft polymers formed by cerion ion-catalyzed graft polymerizations on the aforementioned polycwaternary ammonium polymers are unusually effective as flocculants, paper dry strength agents, and dye retention agents.

10 Water-soluble cationic polymers have been used in a number of applications, including the pulp and paper industry, to increase strength and dye retention, in the water treatment for flocculating suspended solids, and in the wastewater treatment for assisting 15 when dewatering sludge. New materials that are effective in these applications are constantly being synthesized and researched, and materials with improved properties would be readily accepted.

An object of the invention is to provide new cationic enteopelymers. Another object of the invention is to provide new polymers which are effective in a variety of applications, such as flocculation of suspended inorganic and organic matter, additives for retaining dyes and for the dry strength of paper and for dewatering sludge.

Another object of the invention is to provide methods for improving drainage and improving retention of fine particles, dyes, pigments, fillers in starch in the papermaking process, as well as increasing strength, improving gluing and increasing the electrical conductivity of paper and paper board.

A further object of the invention is to provide methods for improving the dewatering of sewage sludge.

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Yet another object of the invention is to provide methods for flocculating impurities in water and methods for improving treating waste liquids.

These and other objects and advantages of the new polymers and methods of the invention will become apparent from the following description.

The invention provides new high molecular weight quaternary ammonium graft copolymers containing a substrate portion 10 and a graft portion. The substrate is a water-soluble polymeric quaternary ammonium material with an amount of hydroxypropylene groups of the general structure 1 according to the formula sheet, wherein A is a tertiary or quaternary nitrogen, characterized in that the number of quaternary nitrogen atoms is greater than the number of tertiary nitrogen atoms. The grafting portion contains polymerized water-soluble nonionic, anionic and cationic vinyl addition monomers. The amount of graft vinyl addition polymer can vary between one-tenth and one hundred times the amount of substrate polycwaternary ammonium polymer.

The graft copolymers described above are used to flocculate suspended inorganic and organic matter in aqueous solutions, to improve draining and / or retention in papermaking, to improve the dry strength of paper, to improve the dye retention, as well as other applications.

The graft copolymers according to the invention contain a substrate part, ie a pre-prepared polymer, and a graft part. The substrate polymer is a cationic polycwaternary ammonium polymer of the ionic type. Generally, these substrate polymers are prepared by the reaction of a ditertiary amine with epichlorohydrin. A suitable method for preparing cationic polyquaternary ammonium polymers suitable for use in the 8203877% -4-

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invention, is the method described in U.S. Pat. No. 4,054,542. Full descriptions are given therein regarding the details of the reagent species as well as the preparation methods. These polymers have a molecular weight of about 40,000.

In addition to the polymers described above, other polymers described in U.S. Pat. No. 4,018,592 may be used. These polymer molecules have molecular weights in the range of 5000.

A polyquaternary ammonium polymer can be distinguished from a polyamine by the functionality of the nitrogen atoms in the polymer. In a polyquaternary ammonium polymer, most of the nitrogen atoms are quaternized, that is, they are covalently bonded to four carbon atoms. In a polyamine, most of the nitrogen atoms are not quaternized. Polyamines will have nitrogen atoms, which are primary, that is to say bonded to a carbon atom to two hydrogen atoms, secondary, that is to say bound to two carbon atoms, and a hydrogen atom and tertiary, that is to say bonded to three carbon atoms. In addition, polyamines can have some nitrogen atoms, which are quaternary; but these quaternary nitrogen atoms are considerably less than half of the total number of nitrogen atoms.

A polyquaternary ammonium polymer is prepared from a ditertiary amine and another difunctional monomer, for example epichlorohydrin. The reaction between the two monomers combines a carbon atom of the difunctional monomer with a nitrogen atom on a tertiary nitrogen to form a quaternary nitrogen.

In the process which yields polyamines, very few reactions occur which lead to quaternary ammonium groups. Generally, a polyamine is prepared from a multifunctional amine, such as diethylene triamine, which contains some primary and some secondary nitrogen atoms. The polymerization reactions between the multifunctional amines and difunctional 8203877 J * -5 monomers, such as epichlorohydrins, will change primary nitrogen atoms to secondary nitrogen atoms and secondary nitrogen atoms to tertiary nitrogen atoms. Inevitably, some of the tertiary nitrogen atoms formed in previous 5 reactions will be converted to quaternary groups, but considerably less than half of the nitrogen atoms will be quaternized.

Polyamines can also be prepared from methylamine and epichlorohydrin as described in U.S. Patent 3,567,659. In this process, a well-considered effort has been made to reduce the amount of cross-links by minimizing the formation of quaternary nitrogen atoms. The polyamine prepared according to this US patent has the formula 2 of the formula sheet.

In solutions with an acidic pH, these polyamines are converted into the cationic form, for example the hydrochloride salt of the formula III of the formula sheet.

The structure of a typical polycwaternary ammonium polymer used as a substrate in the present invention has the formula 4 of the formula sheet, wherein A is a tertiary or quaternary nitrogen atom, characterized in that the number of quaternary nitrogen atoms is always is greater than the number of tertiary nitrogen atoms.

In the processes used to prepare polycwaternary ammonium polymers, a deliberate attempt is made to have as many nitrogen atoms in the quaternary form as possible. More than 50% of the nitrogen atoms in polyquaternary ammonium polymers are quaternary nitrogen atoms.

The graft of the polymers of the invention is prepared by the graft polymerization of water-soluble vinyl monomers onto the body of the substrate. The water-soluble monomers used in the present process include acrylamide, methacrylamide, acrylic acid, methacrylic acid, dimethylaminoethyl methacrylate, N, N-dimethylacrylamide, dimethylaminopropylmethacrylamide, methacrylamidopropyl-8203877-6

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trimethyl ammonium chloride, dimethyl diallyl ammonium chloride, the quaternization product of dimethylaminoethyl methacrylate with methyl chloride, the quaternization product of dimethyl aminoethyl methacrylate with dimethyl sulfate and other water-soluble monomers, which will be apparent to those skilled in the art. Mixtures of two or more of the water-soluble vinyl monomers can also be used.

Preferred mixtures include acrylamide with one or more of the other aforementioned monomers. The most preferred mixtures are acrylamide and acrylic acid, acrylamide and dimethylaminoethyl methacrylate, acrylamide and the quaternization product of dimethylaminoethyl methacrylate with dimethyl sulfate, and acrylamide and the quaternization product of dimethylaminoethyl methacrylate with methyl chloride. Also included are mixtures of three or more monomers, such as acrylamide, acrylic acid and the quaternization product of dimethylaminoethyl methacrylate with dimethyl sulfate.

The graft polymerization can be initiated in several ways. High energy radiation, such as gamma rays or electron accelerators, are suitable methods for use in many graft polymerizations. Photochemical initiation is also a suitable source of radicals, which are effective in promoting graft polymerizations.

The preferred method of initiating polymerization to form the cationic polyquaternary ammonium graft copolymers of the invention is to use chemical catalysts. The reaction between ferrous ion and hydrogen peroxide is such a preferred catalyst system. Other chemical catalysts are known to those skilled in the art.

A very preferred method of initiating these graft polymerizations is the use of ceri salts. Cerion is believed to react with pendant hydroxyl groups present in the substrate polymer. These hydroxyl groups are formed by the reaction of epichlorohydrin with ditertiary amine. The product of this reaction is a polymer, which alternately contains quaternary ammonium ions and hydroxypropylene units.

The radical resulting from the reaction of cerion with the hydroxyl groups reacts with vinyl monomers. Polymerization then continues, when more vinyl monomers are added and a new polymeric graft chain forms, one end of which is covalently bonded to the substrate polymer. The result of this graft polymerization is the cationic polycwaternary ammonium graft copolymer according to the invention.

The reaction conditions can be varied widely. The graft copolymers of the invention can be prepared under conditions in which the proportions, by weight, of the polyquaternary ammonium polymer (substrate) and the vinyl monomer (graft) are approximately equal. For example, the weight ratio of substrate and vinyl-15 monomer can be in the range of, for example, ten to one to ten. Graft copolymers with molecular weights of up to a million or more have been prepared by this method.

It has been found that even higher molecular grafts are prepared when the weight ratio of substrate and monomer 20 is considerably less than one in ten. Extremely high molecular graft copolymers are obtained, for example, when the ratio of substrate and monomer is about one in fifty. Products prepared using these reagent ratios are highly effective flocculants. When bearing molecular products are desired, high weight ratios of substrate an monomer are preferred. In addition, as shown in U.S. Pat. No. 3,711,573, isopropanol or other chain transfer agents can be added to the reaction mixture to reduce molecular weight.

In general, it is desirable to have an end product that has a high polymer solids content. Storage and transportation costs of polymer solutions with low solids contents increase the cost of the product and make it uneconomical, even when the polymer properties are superior 8203877

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-8-. Water-soluble polymers, the molecular weights of which are about a million or higher, give very viscous aqueous solutions. The upper limit of the polymer content in an aqueous solution of a high molecular weight, water-soluble polymer is less than 10% for molecular weights close to one million. Solutions containing a higher polymer solids content are too viscous to be used in many situations.

In a preferred embodiment of the method 10 for preparing such high molecular graft copolymers, while maintaining a high total polymer solids content, a small weight ratio of substrate polymer and monomer is used. The total solids (substrate polymer plus monomer) are kept high, above 15 10%. The reaction is initiated with a cerion ion catalyst and polymerization continues. To prevent gel formation when the viscosity starts to rise, additional low molecular weight polyquaternary ammonium polymer (substrate) is added. Since the polymer content of the substrate solution can be 25% or more, the total polymer solids content in the graft copolymer solution does not decrease. To further control the viscosity of the graft copolymer solution, isopropanol or other chain transfer agents can be added either before, simultaneously or after adding the added polymer substrate solution.

Depending on the amount of monomer in the initial charge and the amount of polyquaternary ammonium substrate polymer added in the second charge, the final polymer solids content can range from 25 to 50% or more.

The conditions necessary for efficient graft polymerization are not critical. The pH of the solution should be acidic, in a range of 1 to 4 pH units. The monomer does not have to be of high purity. Acrylamide, for example, is often added as a 50% aqueous solution containing copper ions as a polymerization inhibitor.

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While some advantage is obtained by ion exchange copper removal, due to the availability of somewhat higher molecular weights, this purification step is not critical or necessary.

5 Temperature is also not a critical parameter. Good grafting efficiency is obtained at ambient temperatures as well as at a higher temperature. Removal of oxygen from the solution is often used, resulting in higher molecular grafts, but this is not critical. An adequate polymerization efficiency and molecular weights are obtained if no attempts are made to remove oxygen.

It will be understood that when two or more monomers are copolymerized, different properties are obtained when the relative concentrations of the monomers are different. The same applies to graft copolymerizations.

For certain applications, for example dewatering sludge, it has been found that higher ratios of a cationic monomer, for example, the dimethyl sulfate hydrating product of dimethylaminoethyl methacrylate, and acrylamide will give a product with superior properties. For other applications, for example water clarification, the best results are obtained when the graft portion contains only small amounts of cationic monomer and also when the graft-25 "portion is completely nonionic, i.e. a polyacrylamide graft.

The invention will now be illustrated in the following examples, in which parts are parts by weight.

Example I

This example illustrates the preparation of a polyquaternary ammonium polymer suitable as the substrate polymer with subsequent graft polymerizations.

An epichlorohydrin-methylamine prepolymer was prepared by reacting 300 parts of a 50% aqueous 8203877-10-methylamine solution with 2424 parts of epichlorohydrin. The reaction was performed at 35 ° C in 600 parts of n-propanol solvent. When the reaction was completed, 272 parts of concentrated sulfuric acid was added.

The polycwaternary ammonium polymer was then prepared by adding 2007 parts of water and 2275 parts of an aqueous solution containing 60% Ν, Ν, Ν "," tetramethyl ethylene diamine. The mixture was heated to 75 ° C until the contents of the vessel became viscous, at which point the reagents were diluted with 7678 parts of water. The mixture was heated again and the reaction continued until the viscosity rose again. The polymerization reaction was stopped by adding 402 parts of sulfuric acid and 298 parts of water. The final solution contained 25% by weight polymeric solids. More than 80% of the nitrogen atoms in this polymer were quaternary ones.

Example II

This example describes the method for the preparation of a graft copolymer according to the invention.

In a 1 liter glass reaction kettle equipped with a stirrer, thermometer and nitrogen bubble tube, 250g of the polycwaternary ammonium polymer of Example 1, 100g of a 50% aqueous acrylamide solution and 147g of deionized water were added. The solution was stirred and purged with nitrogen to remove dissolved air. To this mixture were added 3 ml of a catalyst solution, which consisted of 0.1N cerium ammonium nitrate and 1N nitric acid.

A reaction immediately took place. The temperature rose and the solution became very viscous in about 5 minutes. The reaction was allowed to continue for 2 hours. The resulting solution contained 22.5% of the polycwaternary ammonium acrylamide graft copolymer, in which about 55.6% of the graft copolymer was from the substrate and about 44.4% of the 8203877 9 Ο-11 graft copolymer polymerized acrylamide. used to be.

Example III

This example describes the preparation of another polyquaternary ammonium polymer, which is suitable as a substrate polymer in the subsequent graft polymerizations.

The ionic polymer, poly / hydroxyethylene (dimethyliminio) ethylene (dimethyliminio) methylene dichloride / was prepared by mixing 375 parts of an aqueous solution containing 60% N, N, NT, NT-tetramethyl at a temperature below 50 ° C ethylene diamine (TMEDA) and 4496 parts of muriatic acid (31.5% HCl). While the temperature was kept at 40-50 ° C by cooling, 3588 parts of epichlorohydrin were added. The mixture was further stirred for an additional 0.5 hours and then heated at 60-70 ° C, at which temperature it was held, adding 3750 parts of additional aqueous solution of TMEDA. The concentration was adjusted to 60% polymer solids by distilling off part of the water from the product. The molecular weight of the product is about 20 5000. All nitrogen atoms in this polymer were quaternary nitrogen atoms.

Example IV

This example illustrates a method of preparing graft copolymers using as the substrate of the polymer of Example III.

The general method of Example II was used except that 313g of water, 100g of a 50% acrylamide solution and 84g of the polyquaternary ammonium polymer of Example III were added to the reaction kettle. 3ml Ceri catalyst was added and a viscous polymer solution was obtained in a few minutes. Another 25 ml of catalyst were added 25 minutes after the addition of the first 3 ml of catalyst. Another 25 ml of ceri catalyst were added 25 minutes after this second catalyst addition. The resulting 8203877 y-12-clear, viscous solution contained about 20.1 wt% polymer, about half of which was graft acrylamide and the remainder derived from the substrate polycwaternary ammonium polymer of Example III.

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Examples V - XI

The general method of Example II was used, except that 118.5g of water, 7.5g of isopropanol, 70g of acrylamide and 250g of the polycwateric polymer of Example 1 were stirred in the reaction flask. In addition to the acrylamide, the water-soluble vinyl addition monomers listed in Table A were used in separate preparations.

In all cases, 30 g of the listed monomers were added. 3ml Ceri catalyst were added. In all cases, the temperature rose and the solution became viscous, indicating that graft polymerization was taking place. Additional ceri catalyst (3 ml per addition) was added. A total of 24 ml of catalyst were always added, except in Example XI, where only 12 ml were added. In this case, the solution was already extremely viscous.

Table A

Example Comonomers used with Total polymer acrylamide to form solids _ graft copolymer _ 25 V dimethylaminoethyl methacrylate 24.3 methosulfate (80% solution) VI dimethylaminoethyl methacrylate methyl chloride (75% solution) 24.0 VII dimethylaminopropyl-25.5 methacrylamide 30 VIII methacrylamidopropyltrimethyl- 22.5 ammonium chloride (50% solution) IX dimethyldiallylammonium chloride 25.5 XN, N dimethylacrylamide 25.5 35 XI acrylic acid 26.1 8203877

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Example XII

The procedure of Example II was followed, except that the cerica catalyst was not used. To the reaction kettle were added 250g of the polyquateral ammonium polymer of Example I, 100g of a 50% acrylic amide solution and 147g of water. The pH was adjusted to 3.5 with 50% sodium hydroxide.

Two milliliters of 0.35% hydrogen peroxide were added to the flask, quickly followed by 2 ml of a solution consisting of a 0.1M ferrous ammonium sulfate in 1M sulfuric acid.

A temperature rise immediately occurred, accompanied by an increase in viscosity. The reaction was allowed to proceed for 40 minutes, after which 7.5 ml of isopropanol was added followed by another batch of the catalyst, ie 2 ml of 0.35% hydrogen peroxide and 2 ml of the ferrous solution . Two more additions of the catalyst system (ferrous solution and H2O2) were made over the next 2 hours. The resulting solution was identical in appearance and composition to the product of Example II, except that the product of this example contained a slightly lower polymer solids content, 21.6%.

Example XIII

The following example describes the preparation of the polyquateral ammonium graft copolymer of the invention using a combination of two catalyst systems.

The method of Example II was followed. 250g of the polymer of Example 1, 100g of a 50% acrylamide solution and 147g of water were added to the reaction flask. 3 ml of the ceri catalyst were added. The temperature rose and the solution became viscous. 2 Hours after the reaction was initiated, 7.5 ml of isopropanol was added, followed by 2 ml of 0.35% hydrogen peroxide and 2 ml of the ferrous sulfate solution described in Example XII. A significant amount of unreacted monomer was present after the first addition of the ceri catalyst, since there was a direct rise in temperature and a slight rise in viscosity. Two subsequent additions of 2 ml of the peroxide and the ferrous solutions were made. After the last catalyst addition, no noticeable reaction took place. The product of this example was very similar in appearance and composition to the product of Example XII.

Example XIV

The following illustrates another method of preparing the graft copolymers of the invention.

The general method of Example II was followed, except that two reaction vessels were charged with 100kg of a 50% acrylamide solution, 147g of water and 4g of the polyquaternary ammonium polymer of Example I. The ratio of acrylamide and polyquaternary ammonium polymer was therefore 50 to 1 on a solid basis. 3 ml of Ceri catalyst solution were added to each kettle. A direct rise in temperature occurred in each solution followed by a rapid rise in viscosity. When the viscosity became so great that the solution started to rise along the agitator shaft, 250 ml of water were added to the first kettle. Solution 14A and 250 ml of the polyquateral ammonium polymer of Example I were added to the second kettle, solution 14B. The reactions continued as evidenced by a slight rise in temperature and a marked rise in viscosity. Two hours after the first catalyst additions, an additional 300 ml of water were added to solution 14A. Then 7.5 ml of isopropanol was added to each solution, followed by addition of 2 ml of dilute hydrogen peroxide and 2 ml of the ferrous solution described in Example XII. A second 2 ml aliquot of the ferrous solution and the peroxide solution was added to each solution. The solutions obtained had about 6.3% polymer solids for solution 14A and 21.8% in solution 14B.

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Example XV

The polyquaternary ammonium graft polymers of the invention were tested for their effectiveness as flocculants in laboratory beaker tests. 1500 ml of a 0.4 wt.% Suspension of bleaching earth (kaolin) were added to each beaker and stirred with blades at a rotation speed of 100 revolutions per minute. Different amounts of the polymer solution to be tested were added and stirring was continued for 1 minute, then stirring was stopped and the suspension was allowed to settle for several minutes. Investigations took place after the flocculation rate, i.e. the settling speed, as well as the final clarity of the above solution after 5 minutes.

The flocculation rate was assessed qualitatively and the polymers were arranged in order of a flocculation rate. The clarity of the test solution was indicated on a scale from 0 to 5 (0 means no settling and 5 means a clear supernatant) after settling for 5 minutes.

Table B compares the properties of the graft copolymer prepared in Example II with two commercially available products, both of which are used to treat water, to remove the suspended substance. Commercial product A is 25 wt% and commercial product B is 40 wt% polymer solids. A dilute solution (1500 ppm) of each polymer product to be tested was first prepared. Then 2, 4 or 8 ml of these diluted polymer solutions were added to the kaolin suspension. The rate of consumption of each polymer diluent was therefore 2, 4 or 8 ppm. However, since the products differ on a weight percent basis, the consumption rate on a total polymer solids basis is of course different.

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Tab el B

Brightness rating at 2ppm 4ppm 8ppm consumption rate

Product of example II

(22.5%) 3.1 3.5 4.4

5 Commercial product A

(25%) 3.4 3.8 3.5

Commercial product B

(40%) 3.2 3.4 3.3

The product of Example II gave the fastest settling speed at any operating rate. Table B shows that the two commercial products provide good clarity at these usage rates, with a maximum effect near 4 ppm. The product of Example II, in addition to a fastest settling time, gave a significantly better brightness at slightly higher usage rates, without decreasing effectiveness at higher usage rates. Excellent effectiveness occurs over a wider range of consumption rates.

Example XVI

This illustrates the effectiveness of the polycwaternary ammonium graft copolymers for flocculation of the suspended material when the graft portion of the polymeric product is a mixture of acrylamide and other water-soluble vinyl addition monomers.

The method of Example XV was followed. Polymer solutions to be tested were prepared from the products of Examples V to X, as well as Example II. The results are shown in Table C.

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Example Comonomer Clarity at ______ consumption rate of 2 ppm 5 ppm 5 II Acrylamide only 3.1 4.0 V Dimethylaminoethyl methacrylate methosulfate 3.4 4.2 VI Dimethylaminoethyl methacrylate methyl chloride 3.1 4.0 VII Dimethylaminopropyl 10 methacrylamide 2.8 3.7 VIII Methacrylamidiopropyl trimethylammonium chloride 2.9 3.8 IX Dimethyldiallyl ammonium chloride 2.8 3.8 XN, N-Dimethylacrylamide 2.9 3.9 15

All graft copolymers in dafcabel have excellent flocculation properties.

Example XVII

This example illustrates the effectiveness of the graft copolymers of the invention as flocculants for sewage sludge.

The facility consisted of a No. 1 Buchner funnel placed directly above a graduated 25 250 ml cylinder. A piece of filter cloth was cut to the same size as No. 1 filter paper and this filter cloth was placed in the Biichner funnel. This filter cloth was of the same type used in sludge dewatering presses.

5% Dilutions of the polymer solutions to be tested were prepared. In each run, 500 ml of sewage sludge (3.4% solids) were placed in a beaker. The desired amount of diluted polymer solution was placed in a second beaker. The sludge was then poured back and forth between the beakers three times to ensure complete mixing. The resulting mixture was then poured into the Biichner funnel on the 8203877-18 filter.

The solution was allowed to drain by gravity, that is, no pressure or vacuum was applied. The cylinder in the graduated cylinder collected amount of liquid was measured after 15, 30 and 120 seconds. The better the effectiveness of the polymer for sludge dewatering, the more liquid will be collected at some point.

Two graft polymers were prepared for study. The method of Example VI was used to make Solution D. The reaction kettle was charged with 147g of water, 250g of the polyquaternary aimnonium polymer of Example I, 70g of a 50% aerylamide solution and 30g of an 80% aqueous solution of dimethylaminoethyl methacrylate methosulfate. Ceri-15 catalyst was added nine times in 3 ml aliquots over the next 4 hours.

Solution E was prepared on a slightly larger scale. A 2 liter reaction kettle was charged with 828g of water, 100Qg of the polyquaternary ammonium polymer of Example 1, 160g of a 50% acrylamide solution and 4Qg of isopropanol. 12 ml of Ceri catalyst were added.

Table D shows the sludge dewatering effectiveness of solutions D and E, compared to the effectiveness of a commercially available cationic polyacrylamide polymer used in sludge dewatering processes.

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Table D

Assayed Added volume Volume in milliliters of 5% polymer solution _ collected after_ solution 15 sec. 30 sec. 60 sec. 120sec.

—— milliliters 5 Solution D 4 26 38 '53 73 6 45 65 78 93 8 60 80 98 116

Solution E 4 27 '35 50 65 6 50 65 '83 100 10 8 55 75 93 105

Commercial 4 19 23 31 41

Cationic 6 32 45 60 75

Polyacrylamide 8 52 70 85 101

This table shows that graft copolymers according to the invention are effective in dewatering sewage sludge.

Example XVIII

The polymeric blends of Example XV of the invention were tested for their effectiveness in retaining total solids in a paper pulp slurry using the method described in Example XV of U.S. Patent 4,250,269, which is incorporated herein. should be considered.

Fractionation of the paper pulp slurry showed that the slurry contained 27% fines. Retain percentage of fines to be calculated when the total solids hold and the percentage of fines in the original slurry were known. Table E shows that the polycwaternary ammonium acrylamide graft copolymer of Example II is better than the ungrafted polycarnary ammonium polymer of Example I, a product currently used as a retention agent.

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Table E

Investigated Application Quantity% Product Retention Pounds per ton / pulp of fine materials

Control without holding device 0 59.6 5 Example I 0.75 65.3 1, 50 69.6 2.50 71.5 5.00 71.2

Example IX 0.675 67.3 10 1.35 69.2 2.25 74.3 4.50 81.8

Example XIX

This example illustrates the effectiveness of the graft copolymers of the invention in increasing the dry strength of paper.

Hand sheets were manufactured and examined using a Scott Internal Bond Tester. 300g From a 1.5% 20 hardwood Kraft pulp, which had been purified into a Canadian

540 ml Stand Freeness were added to 300 ml of water.

The desired amount of dilute polymer solution was added to obtain the consumption rates set forth in Table F below. The solutions tested 25 were the product of Example II in which the graft portion contained only acrylamide, the product of Example VII in which the graft portion contained acrylamide and dimethylaminoethyl methacrylate methyl chloride, and the product of Example XI, wherein the graft portion contained acrylamide and 30 Ν, Ν-dimethylacrylamide. The aforementioned copolymers were compared with the product of Example 1, a non-grafted polyquaternary ammonium polymer currently used in the paper industry to increase bond strength.

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Table F

Investigated Quantity of application Increase in percent product Pounds per ton / pulp Scott bond strength

Example I 10 14 5 Example II 10 16

Example VII 10 24

Example XI 10 18

The graft copolymers of the invention provide greater bond strength, and the presence of cationic comonomers in the graft gives the best improvement.

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Claims (16)

Water-soluble high molecular weight quaternary ammonium graft copolymer containing as substrate a water-soluble polymer quaternary ammonium material having multiple hydroxy-5-propylene groups of the formula 1 of the formula sheet, wherein A is a tertiary or quaternary nitrogen atom, characterized in that the number of quaternary nitrogen atoms is always greater than the number of tertiary nitrogen atoms, and the present part of the product is a polymeric material selected from the group consisting of water-soluble non-ionic, anionic and cationic vinyl addition polymers, and that further characterized in that the amount of grafting vinyl addition polymer varies between one-tenth and one hundred times the amount of substrate polyquaternary ammonium polymer. Graft copolymer according to claim 1, wherein the vinyl addition polymer is polyacrylamide. Graft copolymer according to claim 1, characterized in that the vinyl addition graft polymer is a copolymer of acrylamide and acrylic acid. Graft copolymer according to claim 1, characterized in that the vinyl addition graft polymer is a copolymer of acrylamide and the quaternization product of dimethylaminoethyl methacrylate with dimethyl sulfate. Graft copolymer according to claim 1, characterized in that the vinyl addition graft polymer is a copolymer of acrylamide and the quaternization product of dimethylaminoethyl methacrylate with methyl chloride. Graft copolymer according to claim 1, characterized in that the vinyl addition graft polymer is a terpolymer of acrylamide, acrylic acid and the quaternization product of dimethylaminoethyl methacrylate with dimethyl sulfate. Graft copolymer according to claim 1, characterized in that the vinyl addition graft polymer is a terpolymer of acrylamide, acrylic acid and the quaternization product of dimethylaminoethyl methacrylate with methyl chloride. 8203877 -23 " Graft copolymer according to claim 1, characterized in that the sub-treat is a water-soluble polymeric quaternary ammonium material, derived from metbylamine, epichlorohydrin and Ν, Ν, Ν ', Ν'-tetrarnethylethylenediamine. Graft copolymer according to claim 1, characterized in that the substrate is a water-soluble polymeric quaternary ammonium material derived from epichlorohydrin and Ν, Ν, Ν ', N'-tetramethyl ethylene diamine. Graft copolymer according to claim 1, characterized in that the substrate is a water-soluble polymer quaternary ammonium material, derived from methylamine, epichlorohydrin and Ν, Ν, Ν ', Ν'-tetramethylethylenediamine and the vinyl addition graft polymer is polyacrylamide. Method for increasing the rate of water removal from wet fibrous webs during the manufacture of paper and paper board, characterized in that in the papermaking system the graft copolymer according to claim 1 is added in an amount sufficient for obtaining the desired increase in water removal. 12. A method for improving the retention of the components of a papermaking additive to the wet fibrous web during the manufacture of papermaking and papermaking, characterized in that the graft copolymer according to claim 1 is added to the papermaking system in an amount sufficiently is for obtaining the desired increase in retention. A method of increasing the strength of paper and paper board, characterized in that the graft copolymer according to claim 1 is added to the papermaking system in an amount sufficient to obtain the desired increase in strength. 14. Method for gluing paper or paper board, characterized in that the graft copolymer according to claim 1 is added to the papermaking system in an amount sufficient for gluing the paper and paper board. 8203877 -24- A method of flocculating solids from an aqueous system containing suspended or dissolved solids, characterized in that it is attached to the aqueous system. as the flocculating agent, the graft copolymer according to claim 1 is added in an amount sufficient to effect flocculation of the solids. 16. A method for increasing the rate of water removal during the dewatering of wet mud from urban or industrial effluent, characterized in that the graft copolymer according to claim 1 is added to the wet mud in an amount sufficient for increase the rate of water removal. 8203877