KR19980702368A - Cellulose particles, preparation method thereof and uses thereof - Google Patents

Abstract

According to this invention, the cellulose particle which has a cationic group also in the inside of a particle is provided.

Description

Cellulose particles, preparation method thereof and uses thereof

The present invention relates to cellulose particles and a method of making the same. Moreover, the present invention addresses the application of cellulose particles.

Various countermeasures, such as concentration of circuits, increased use of de-inked pulp and wood pulp and high yield pulp such as TMP (thermomechanical pulp) and, due to the neutralization process, interfere with the water circulation system in the paper industry. The burden of) increases.

Interfering materials were initially defined as all materials that reduce the efficacy of cationic retention aids in paper stock, i.e. materials added to enhance the persistence of the fiber / filler mixture on the transfer path. Recently, more precisely this definition has been mentioned. Thus, the interference materials are dissolved or colloidally dissolved anionic oligomers or polymers and nonionic hydrocolloids.

These interfering substances exhibit various effects. They hinder the action of lasting, dry and wet reinforcements, i.e. materials to increase the strength of papermaking, and furthermore, impediments to deposits, forming and draining processes inside the circulation path of the papermaking machine, and damage to paper strength, whiteness and opacity. Causes

To remove the adverse effects of these interferences on the papermaking process, alum, polyaluminum chloride, low molecular and high molecular weight fixatives, cationic starch and inorganic adsorbents are used. All these materials attach to anionic waste with the help of electrostatic interactions, forming complexes with them. Through the binding of these complexes to the fibers or through the filtering effect on the network, these coagulum is removed from the papermaking system.

However, all these products have their own disadvantages. For example, aluminum salts are limited to use in neutralization treatments, which are gaining importance because of the increased use of calcium carbonate as filler, because they are not cationicly charged in this pH range and are not very effective.

On the other hand, the use of highly charged cationic polyelectrolytes poses a problem of accurate metering. If accurate metering is not achieved, excess cationization or cationic dispersion of the papermaking circuit can occur. This means that retention of poor micromaterials and reduction in size can occur.

It is an object of the present invention to provide novel cellulose particles characterized by specific properties and possible applications. Furthermore, an object of the present invention is to provide a cellulose particle which can be removed from a circulation path without causing the above-mentioned problem by confining the amount of interference material inside the paper circulation path, the device circulation path or the water circulation path as much as possible. Is in.

It is also an object of the present invention to provide another possible application of the cellulose particles.

The present invention is based on the discovery that this problem can be solved by cellulose particles having cationic groups even inside the particles.

Thus, at least 10%, preferably at least 50% and in particular at least 90% of cationic groups are generally present inside the particles. As a result, cellulose particles are provided in which the cationic groups bound to the cellulose are distributed over the entire cross-sectional area of the particles.

In order for the particles to have sufficient cationicity, there must be at least one cationic group per 100, preferably 50 anhydroglucose units of cellulose.

In order to produce the cellulose particle of this invention, a cellulose is made to react with a cation agent.

The cellulose used may be not only unsubstituted pulp but also substituted cellulose, in particular cellulose esters or ethers such as methyl cellulose, carboxymethyl cellulose, cellulose sulfate, cellulose acetate or chitosan. The degree of substitution (DS) must be less than 1, ie only one of the three OH groups of the anhydroglucose unit for the cellulose should be substituted on average. The DS described above should not be too large so that a sufficient number of hydroxyl groups can be used for reaction with the cationic agent. Moreover, alkaline cellulose, in particular sodium cellulose, can be used as the cellulose described above.

The reaction of the cellulose with the cationic agent may be performed as a solid reaction. The cellulose used may be alkaline cellulose which reacts with the cationic agent in the mixer.

In order to produce the cellulose particles of the present invention described above, the cellulose may be dissolved and the dissolved cellulose may be mixed with a cationic agent to precipitate the cationic and dissolved cellulose into the cellulose particles.

Dissolution of cellulose converts cellulose into sodium xanthogenate with sodium hydroxide and carbon disulfide, which is N-methylmorpholine-N-oxide and lithium dimethylacetamide. , Tetraammine copper copper (II) hydroxide, cupriethylenediamine or cuprammonium.

N-methylmorpholine-N-oxide monohydrate has a melting point of about 70 ° C. Thus, it can be easily recovered as a solid. In contrast to xanthogenic acid salts, no odor is generated and no wastes such as sodium sulfate are obtained.

In the case of the water-soluble cellulose derivative, water may be used as the solvent. The water soluble cellulose derivative may preferably be prepared by a viscose process.

The cationic group may be covalently bonded to the hydroxyl group of the cellulose. However, binding by ionic and / or hydrogen crosslinking is also possible.

The cationic agent used may be an aluminum salt such as polyaluminum chloride or sodium aluminate. The polyaluminum chloride can be partially hydrolyzed. The aluminum acid salt is precipitated together with the xanthogenic acid salt with sulfuric acid.

Furthermore, the cationic agents used are, in particular, polydialkyldiallylammonium salts such as polydialkyldiallylammonium chloride (poly-DADMAC), dicyandiamides, dicyandiamide condensates, polyamines, polyethylene imines and the like. It may be a cationic polyelectrolyte such as polyimine or ionene. In addition, the cationic agents used may be reactive monomers such as primary amine, secondary amine, tertiary amine and quaternary amine salts, each having at least one residual group which reacts with the hydroxy group of the cellulose.

If, as in the case of aluminum salts and cationic polyelectrolytes, the cationic agent does not react with the hydroxyl groups of the anhydroglucose units of cellulose, the solubility of the cellulose does not change significantly or at all. In this case, the ratio of cationic agent to cellulose can vary within wide limits. Normally, however, the weight ratio of aluminum salt or cationic polyelectrolyte to cellulose is from 0.03: 1 to 1: 1 based on the absolute dry material.

However, the reactive monomer preferably participates in cellulose in an amount such that the degree of substitution (DS) is not greater than 0.2. Otherwise, cellulose particles with excessive water solubility may be produced.

The cationic agent with the reactor used, ie the reactive monomer, may in particular be 2-chloroethane trimethylammonium chloride or propoxytrimethylammonium chloride.

By precipitating dissolved cellulose with a high degree of substitution, such as carboxymethyl cellulose in an aqueous solution with a cationic polyelectrolyte, the cationized cellulose particles of the present invention can likewise be obtained.

In the cellulose particles of the present invention, since the cationic charge is mainly fixed inside the particles, the particles can be crushed (crushed) in order to make the charge acting as a functional group more available.

If a reactive monomer is used as the cationic agent, the reactor is a residual group that reacts with the cellulose hydroxyl group. The reactive residual group can be for example a halogen atom, an epoxy group or an imino group. To form an epoxy group, for example, a halogen atom may be bonded to one carbon atom of an alkyl residue of an amine or quaternary amine base, and the hydroxy group may be bonded to an adjacent carbon atom. For example, the ammonium compound may be 3-chloro-2- (hydroxypropyl) -trimethylammonium chloride.

In order to prevent crosslinking of individual cellulose fibers, especially in the case of dicyandiamide and other polyelectrolytes, the cellulose can react with the cationic agent in a relatively high diluent. That is, when mixed with the cationic agent, the dissolved cellulose is preferably present at a concentration below 2% by weight, in particular below 1% by weight.

Preferably, the reaction of the dissolved cellulose with the cationic agent is carried out with stirring for a period of, for example, 10 seconds to 30 minutes depending on the reactivity of the cationic agent. If the reaction time is too long, there is a risk of the aforementioned crosslinking.

Precipitation of the dissolved and cationic cellulose can be achieved, for example, by fine spinning spraying in a precipitation tank.

If the dissolved cellulose is cellulose xanthogenate, the precipitant may be, for example, polyaluminum chloride or sulfuric acid, where sulfuric acid, such as sodium sulfate or zinc sulfate, may optionally be added.

As is apparent, the cellulose particles may also be obtained by adding a precipitant with stirring to the dissolved cationized cellulose, causing precipitation to take place directly in the reactor.

Thus, the size of the cellulose particles or the length of the precipitated cellulose fibers, among other things, depends on the rate of stirring during the dilution and precipitation of the dissolved and cationic cellulose.

The particles of cationized cellulose preferably have an average particle diameter of 0.001 to 10 mm, in particular an average particle diameter of 0.1 to 1 mm. The particles are preferably spherical. However, they may also be present in fibrous form.

The desired size and structure of the cellulose particles can in particular also be obtained by grinding.

To pulverize the cellulose particles, a wide variety of grinding devices, in particular standard devices for pulp grinding, such as Jokro mills, conical grinding machines or disc grinding machines can be used. Also suitable are mills commonly used to mill papermaking fibers. Grinding results in substantial enlargement of the cellulose particle surface, thus increased cationicity and efficacy.

The only accompanying drawing shows the cellulose particles in a dark field image. The particles are in a swollen state. The particles are spherical in three dimensions as a papermaking process, but are compressed between slides in the photograph. The magnification is 100 times. It can be readily seen that the fibers are random fibrous structures with a range of 10 to 50 microns.

When using cellulose particles in paper making, the size of the particles should obviously not be thicker than the thickness of the paper, while the fibrous structure can be advantageous.

If cationized cellulose fibers are used as a means of fixing the interference material inside the paper, the fibers must not be longer than 0.5 mm to rule out molding problems. Preferably, the cationized cellulose fiber should not be longer than 0.1 mm.

For other applications such as, for example, flocculants, particularly flocculants for wastewater purification, an average particle diameter of 0.1 to 1 mm is usually preferred.

The cellulose particles are used in the form of solids or suspensions.

The cellulose particles of the present invention may be called water-insoluble. This means that the cellulose particles are not soluble in water with the papermaking process by conventional residence times and application methods. The residence time is in the range of minutes.

In the cellulose particles of the present invention, the cationic group is covalently bonded to cellulose or fixed inside the cellulose membrane. This covalent bond or fixation prevents impairment of the cationic activity during the use of cellulose particles.

The cellulose particles of the invention are used as solids, where they can contain up to 80% moisture. It is also conceivable to dry these cellulose particles and to use them as dry fine particles. They can also be used, for example, in the form of a suspension with a solids content of 3% or in the form of a paste with a higher solids content up to 20%.

Cationic groups present inside the cellulose particles are not affected by mechanical action, for example, are not removed by shear forces caused by stirring.

The cationized cellulose particles of the present invention are an effective means for immobilizing interfering substances inside the paper present in the water circuit during the papermaking process.

Unlike known means for fixing interfering substances inside paper, such as bentonite, the use of such cationic cellulose has no adverse effect on the properties of the paper.

At the same time, the cationized cellulose of the present invention produces fine materials, in particular fine filler particles, which are associated with the fibers, thereby promoting retention of fine materials or ash and distribution of fine materials within the paper, resulting in a more uniform sheet. To get. That is, the cationized cellulose of the present invention allows the fine material to remain on the side and top of the cellulose particle / filler mixture facing the net.

Above all, however, the cationized cellulose of the present invention allows the anionic waste generated in large quantities within the circulation path of the present papermaking machine (as described above) to bind with the cellulose particles of the cellulose particle / filler mixture, thereby removing To be discharged.

In particular, when the cationized cellulose fibers of the present invention are short, i.e., having a length of, for example, 0.1 mm or less, the strength of the filled paper is obviously increased, which is a critical property in determining the quality of the paper. This is probably due to the fact that short cationized cellulose particles are contained in the spaces between the cellulose fibers of the long paper making, forming crosslinks between the cellulose fibers of the paper making.

Thus, in the paper industry, the cationized cellulose particles of the present invention can be used as strength enhancing means for filled papermaking or as means for fixing interference materials inside paper, thereby removing these interferences from the water circuit. have.

Moreover, the cationized cellulose particles of the present invention are a means for retaining fine materials inside the paper during the paper making process. That is, fine ash or other filler particles or other fine fine solid particles that are incorporated within the paper are retained by the cationized cellulose particles of the present invention, ie, to prevent it from being washed away to protect it inside the paper. This makes it possible to achieve increased uniformity and dimensional stability of paper. Since fine materials are better constrained, this at the same time reduces the tendency to blow into dust during the processing of paper. Moreover, the cationized cellulose particles of the present invention enhance the strength of the filled papermaking.

Thus, the present invention particularly includes a method of forming papermaking using a closed water circuit to which the cellulose particles of the present invention are added. Thus, the interfering substance is constrained and not harmful. Generally, 0.1 kg of cationized cellulose particles can be added per tonne of paper stock (absolute dry weight). Due to cost concerns, the upper limit is usually 10 kg / ton.

At the same time, the cationized cellulose particles of the present invention are excellent coagulation aids for organic sludge that does not precipitate well. Accordingly, the cationized cellulose particles of the present invention can be used as flocculants for flocculating sludge, especially in waste water purification, and above all in clarification plants. Compared to conventional flocculants, in particular polyelectrolytes, the cationized cellulose particles of the present invention have a greatly expanded and stable cationic surface from which the aggregated material can precipitate. Thus, in contrast to conventional flocculants, a more stable precipitate can be obtained which can be dehydrated more easily.

When the cellulose particles are used for sludge drying and in the papermaking process, the use of the cellulose particles of the present invention in combination with a water-soluble polymer has proved surprising.

Particularly good results are obtained when combined with a cationic water soluble polymer. However, combinations with anionic or nonionic polymers may also be considered.

Particularly preferred combinations have been found to be combinations of the cellulose particles of the present invention with water soluble cationic polyacrylamides. With polyacrylamide, in particular polyethylene imines and water-soluble cellulose derivatives such as for example cationic hydroxyethyl cellulose or carboxymethyl cellulose can be used.

In sludge drying, the water soluble cellulose particles of the present invention are preferably added in a mixture with the water soluble polymer. However, separate additions are also possible.

For example, on the basis of a water-soluble polymer such as polyacrylamide, the amount of the cellulose particles of the present invention has a very wide range of 0.1 to 99.9 wt%. However, the weight ratio of the preferred cellulose particles is 1 to 50%, preferably 1 to 10%. The percentage of cellulose particles is determined by the quality of the sludge, the desired amount of drying for the sludge and the treatment capacity.

In the case of using the above-described cellulose particles of the present invention in combination with a cationic polymer, it is preferable to mix the two components in advance, store them and transport them in a dried state. Before being added, the mixture is dissolved or dispersed in water and then directly added to the sludge without any unnecessary filtration for the sludge.

Since the anionic polymer can react with the cationic cellulose particles, the preferred use for such mixtures of cellulose particles and polymers is only possible with cationic polymers, not anionic polymers. Thus, the anionic polymer is added separately from the cellulose particles.

When the cellulose particles of the present invention described above are used in combination with anionic polymers, the cellulose particles are independently stored, transported, prepared and metered in dry form or in the form of an aqueous suspension. Likewise, the anionic polymer is stored and transported in a dried state, dissolved in water or in an emulsion state.

The synergistic effect obtained by the combination of the water-soluble polymer and the water-insoluble cellulose particles is impressive. However, the mechanism of this action is unknown. For example, experiments with biological sludge, using 94.3 wt% polyacrylamide and 5.7 wt% cellulose particles, compared to pure polyacrylamide, resulted in a band press rate of 62 to 100%. The sludge throughput was found to increase from 28 m 3 / h to 33 m 3 / h.

Another experiment aimed at higher dry contents also showed surprising results. Thus, addition of only 3 wt% of cellulose particles to the polyacrylamide used resulted in an increase in dry content after pressing from 48 to 63%.

The use of a combination of cationic, water soluble polymers and water soluble cellulose particles of the present invention has also shown surprising results, particularly in the papermaking process.

In the papermaking process, separate addition of cellulose particles and a water-soluble polymer is preferred. It is advantageous to continuously filter the water soluble polymer as a solution prior to the metering point in order to filter out gel particles which impair the quality of the paper. It is advisable to add the cellulose particles first and only the water soluble polymer later. In particular, it is preferred to add cellulose particles at the beginning of the papermaking process, while adding a water soluble polymer in the last step just before sheet formation.

Expressed as a time flow, assuming a total purification time of about 90 seconds, the cellulose particles are added at 30 to 60 seconds before feeding the paper stock to the headbox, and the water soluble polymer is about 10 to 20 before that. Add in seconds.

The mixing ratio of the cellulose particles and the cationic polymer can be varied in a wide range, for example 90:10 to 10:90. However, it is preferable to add 40 to 60% of cellulose particles by weight. The preferred amount depends first of all on the grade of the papermaking. Higher percentages are preferred for paper making with smaller fillers.

In the papermaking process, the cellulose particles are preferably added in the form of a suspension contained in water, for example a 3% suspension. The polymer solution is added, for example, as an aqueous solution at a concentration of 0.2 to 0.8%.

When an anionic water-soluble polymer is used in combination with the cellulose particles, the same mixing ratio and addition method or addition start are preferred.

The use of the cellulose particles of the present invention in a papermaking process has proven to be able to obtain a large amount of filler inside the paper. Since the filler is cheaper than papermaking fibers, this is desirable for economic reasons. Fillers give good properties, in particular improved opacity and printability.

Another advantage resulting from the addition of the cellulose particles is improved shaping of the paper, and thus improved paper quality.

The term cellulose particles also refers to fibers of any shape and length in the present specification, especially fibres. Cellulose fibers have a variety of applications in the industrial and textile fields.

A special property of the fibrous cellulose particles of the present invention lies in the greatly improved dyeing behavior. In particular, the fibers can be dyed with advantageous anionic dyes. The dyed fibers are characterized by a special color fixation due to the fact that the cationic groups reacting with the dye are immobilized on the cellulose fibers or covalently bonded to the cellulose molecules.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

Aqueous 8.5 wt% aqueous sodium cellulose xanthogenate solution was diluted with 0.02 N sodium hydroxide in a ratio of 1:25.

25 ml of diluted sodium cellulose xanthogenate was mixed with 1 ml of 40 wt% dicyandiamide aqueous solution with stirring.

After stirring for 5 minutes, the speed was increased (600 rpm) and 5 ml of 18 wt% aqueous polyaluminum chloride solution was added dropwise.

The precipitated cellulose fiber was washed with distilled water until the supernatant had no more cationic charge.

Example 2

100 kg of pulp was converted to alkaline cellulose (AC) with an aqueous 18% sodium hydroxide solution. 20 kg of 3-Cl-2-hydroxypropanetrimethylammonium chloride was added to the pressed AC. The reaction was carried out in a mixer while cooling to 35 ° C. for 6 hours. Then neutralized with hydrochloric acid and washed with distilled water. The resulting cationized cellulose was dried and ground to the required particle size.

Example 3

In order to detect the cationic property of the cellulose fiber obtained in Example 1, methyl red is used as the anionic dye. The cationicity for conventional precipitated unmodified cellulose fibers was compared to the cationized cellulose fibers prepared according to Example 1 above. To achieve this goal, the fibers were mixed with methyl red solution and then centrifuged. After centrifugation, the color of the fibers and the coloration of the supernatants were determined.

In the cationized cellulose fiber prepared according to Example 1, in contrast to the unmodified cellulose fiber, the fiber had a clear coloration, and at the same time the supernatant was decolorized.

As a control, methylene blue was used as the cationic dye. For the weakly anionic unmodified cellulose fibers, the coloring of the fibers was observed, whereas the cationized cellulose fibers prepared according to Example 1 did not show color. In addition, in the cationized fiber, decolorization of the supernatant did not occur.

Example 4

In order to examine the efficacy of the cellulose fibers prepared according to Example 1, papermaking raw materials (raw materials for natural acid rotogravure) from wood ash products were mixed with cationic cellulose fibers prepared according to Example 1. Thus, the sheet was formed according to standard methods. Sheet weight, burst pressure, tear propagation strength and formability to papermaking were determined. The cationized cellulose fibers prepared according to Example 1 above were compared with respect to the comparative tests performed simultaneously (without addition of cationized fibers) for the distribution of fine materials, including the ash distribution, for strength and formability. It turned out to have a positive effect.

Example 5

An agglomeration test was performed with immersion sludge from a wastewater purification plant having a cationized cellulose fiber having an average length of about 4 cm prepared according to Example 1 above, which was very fine and difficult to aggregate. The cationized cellulose fibers provided good cohesiveness, glow settling rate and clear supernatant, whereas comparative experiments with conventional coagulants, ie polyacrylamides, showed very small coagulation.

Example 6

An aqueous 8.5 wt% sodium cellulose xanthogenate solution was diluted with an aqueous sodium hydroxide solution (4 g / l) to 4.25% (as cellulose).

A 40% solution of dicyandiamide formaldehyde condensate resin (Melflock C3, commercially available from SKW Trostberg), a cationic agent, was diluted with distilled water to an active concentration of 2 wt%.

600 ml of the diluted 2% dicyandiamide formaldehyde condensate resin solution described above was stirred with a stirrer at 750 rpm, and then 940 ml of the above described sodium cellulose xanthogenate diluted to 4.25% was slowly added to the stirred cationic agent. .

Then, this mixture containing particles that have already precipitated was slowly added to the settling bath. The settling bath consists of 3000 ml of aqueous solution containing 35 g of sulfuric acid (98%) and similarly stirred continuously. In this precipitation bath, quantitative precipitation of the product occurred. More acid was added if necessary to make the pH less than 2.

The precipitated fibrous product was filtered through a filter funnel equipped with a fine plastic gauze sieve, dissolved and shaken in 1000 ml of deionized water. The pH was adjusted between 4.5 and 5.5 using dilute sodium hydroxide solution.

The precipitated product was once again filtered through a filter funnel equipped with a fine plastic gauze sieve, repeatedly dissolved in 1000 ml of deionized water and shaken until no significant cationicity was detected in the supernatant and then filtered.

During this washing step, residual cationicity, if present, is determined by titration of the aliquots against anionic polymers normalized with a particle charge detector (μTek PCD 02) or by a suitable dye (ortho-toluidine blue) as an indicator. Detected.

The wet product (solid content about 12-20%) was removed from the filter and then stored in this state.

Example 7

An aqueous 8.5 wt% sodium cellulose xanthogenate solution was diluted with aqueous sodium hydroxide solution (4 g / l) to 1% (as cellulose).

The cationic agent 40% polydiallyldimethylammonium chloride (FLOERGER FL 45C, commercially available) was diluted with distilled water to an active concentration of 1 wt%.

2000 ml of the sodium cellulose xanthogenate solution diluted to 1% was stirred with a high shear force stirrer to prevent air from entering the solution. Thereafter, 600 ml of the 1% polydiallyldimethylammonium chloride solution was added to the stirred solution over a period of 30 seconds. The resulting mixture was stirred vigorously for 1 hour.

The reaction of the cellulose xanthogenate solution with the cationic agent causes an immediate rise in the viscosity of the mixture. For example, if the undiluted material viscose and poly-DADMAC are mixed together (in the solids content described above), the mixture immediately solidifies and then separates into solid and liquid phases.

1000 ml of an aqueous solution containing 25 g of sulfuric acid (98%) was added to the stirred mixture, causing precipitation. More acid was added if necessary to keep the pH lower than 2.

The precipitated fibrous product was filtered through a filter funnel equipped with a fine plastic gauze sieve, dissolved and shaken in 500 ml of deionized water. The pH was adjusted between 4.5 and 5.5 using dilute sodium hydroxide solution.

The precipitated product was once again filtered through a filter funnel equipped with a fine plastic gauze sieve, repeatedly dissolved in 500 ml of deionized water, shaken and filtered until no more significant cationicity was detected in the supernatant.

During this washing step, residual cationicity, if present, is determined by titration of the aliquots against anionic polymers normalized with a particle charge detector (μTek PCD 02) or by a suitable dye (ortho-toluidine blue) as an indicator. Detected.

The wet product (solid content about 12-20%) was removed from the filter and then stored in this state.

Example 8

The same procedure as in Example 6 was carried out with another cationic agent, 20 wt% polyethylene imine solution (Polymin SK, a commercially available product from BASF). The polyethylene imine solution was diluted to distilled water to 2% concentration. 600 ml of this diluted cationic agent solution was used for the reaction.

Example 9

The same procedure as in Example 6 was carried out with another 50 wt% aqueous polyamine solution (FLOERGER FL 17, a commercially available product), which is another cationic agent. The polyamine solution was diluted to distilled water to 2% concentration. 600 ml of this diluted cationic agent solution was used for the reaction.

Example 10

An aqueous 8.5 wt% sodium cellulose xanthogenate solution was diluted with an aqueous sodium hydroxide solution (4 g / l) to 4.25% (as cellulose).

Reactive cationic monomer solution (RAISACAT 65, commercially available from Raisio), a cationic agent, contains the following ingredients (about 75% concentration):

1) 3-chloro-2-hydroxypropyl-trimethylammonium chloride ca. 2%

2) 2,3-epoxypropyl-trimethylammonium chloride ca. 66%

3) 2,3-dihydroxypropyl-trimethylammonium chloride ca. 3%

2.2 g of commercial product was diluted to 200 ml with deionized water.

470 ml of the sodium cellulose xanthogenate solution diluted to 4.25% was stirred with a propeller stirrer to prevent air from entering the solution. Then 200 ml of the diluted cationic agent solution was added to the stirred solution over a period of 30 seconds. The resulting mixture was further stirred for 30 minutes.

670 ml of an aqueous solution containing 18 g of sulfuric acid (98%) was added to the stirred mixture, causing precipitation. More acid was added if necessary to keep the pH lower than 2.

The precipitated fibrous product was filtered through a filter funnel equipped with a fine plastic gauze sieve, dissolved and shaken in 500 ml of deionized water. The pH was adjusted between 4.5 and 5.5 using dilute sodium hydroxide solution.

The precipitated product was once again filtered through a filter funnel equipped with a fine plastic gauze sieve, repeatedly dissolved in 500 ml of deionized water and shaken until no significant cationicity was detected in the supernatant and then filtered.

During this washing step, residual cationicity, if present, is determined by titration of the aliquots against anionic polymers normalized with a particle charge detector (μTek PCD 02) or by a suitable dye (ortho-toluidine blue) as an indicator. Detected.

The wet product (solid content about 12-20%) was removed from the filter and then stored in this state.

Example 11

The same procedure as in Example 7 above was performed with another cationic agent, 40 wt% of a particularly highly branched polydiallyldimethylammonium chloride aqueous solution. Polydiallyldimethylammonium chloride was diluted with distilled water as in Example 7.

Example 12

The same procedure as in Example 7 was carried out with a special low molecular weight polydiallyldimethylammonium chloride solution of 48.5 wt%, another cationic agent. Polydiallyldimethylammonium chloride was diluted to 1% with distilled water as in Example 7.

Example 13

The same process as in Example 6 was carried out with a copolymer of polydiallyldimethylammonium chloride and acrylic acid, which is another cationic agent, and an aqueous solution of 40 wt% containing 10% or less of acrylic acid, the monomer component. In this example, the copolymer solution was diluted to 1% with distilled water.

Example 14

An aqueous 8.5 wt% sodium cellulose xanthogenate solution was diluted to 2% (as cellulose) with an aqueous sodium hydroxide solution (4 g / l).

A 29% aqueous polyaluminum chloride solution (EKOFLOCK 70, commercially available from Ekokemi), a cationic agent, was used in undiluted form.

1000 ml of the sodium cellulose xanthogenate solution diluted to 2% (as cellulose) was vigorously stirred with a propeller stirrer while preventing air from entering the solution. Then 21 ml of the undiluted cationic agent solution was added to the stirred solution over a period of 30 seconds. The resulting mixture was further stirred for 1 minute.

1000 ml of an aqueous solution containing 20 g of sulfuric acid (98%) was added to the stirred mixture, causing precipitation. More acid was added if necessary to keep the pH lower than 2.

The precipitated fibrous product was filtered through a filter funnel equipped with a fine plastic gauze sieve, dissolved and shaken in 500 ml of deionized water. The pH was adjusted between 3 and 4 using dilute sodium hydroxide solution.

The precipitated product was once again filtered through a filter funnel equipped with a fine plastic gauze sieve, repeatedly dissolved in 500 ml of deionized water, shaken and filtered.

The wet product (solid content about 12-20%) was removed from the filter and then stored in this state.

Example 15

An aqueous 8.5 wt% sodium cellulose xanthogenate solution was diluted to 2% (as cellulose) with an aqueous sodium hydroxide solution (4 g / l).

A 45% aqueous sodium aluminate solution (Fimar A 2527, commercially available from Mare), a cationic agent, was used in undiluted form.

1000 ml of the sodium cellulose xanthogenate solution diluted to 2% was vigorously stirred with a propeller stirrer preventing air from entering the solution. Then 24 ml of the undiluted cationic agent solution were added to the stirred solution over a period of 30 seconds. The resulting mixture was further stirred for 1 minute.

1000 ml of an aqueous solution containing 37 g of sulfuric acid (98%) was added to the stirred mixture, causing precipitation. More acid was added if necessary to keep the pH lower than 2.

The precipitated fibrous product was filtered through a filter funnel equipped with a fine plastic gauze sieve, dissolved and shaken in 500 ml of deionized water. The pH was adjusted between 3 and 4 using dilute sodium hydroxide solution.

The precipitated product was once again filtered through a filter funnel equipped with a fine plastic gauze sieve, repeatedly dissolved in 500 ml of deionized water, shaken and filtered.

The wet product (solid content about 12-20%) was removed from the filter and then stored in this state.

Example 16

The same procedure as in Example 7 was carried out with modified cellulose (sodium methyl cellulose xanthogenate). Low substituted water insoluble methyl cellulose was used in place of the modified cellulose.

Example 17

A cellulose solution dissolved in lithium chloride, dimethylacetamide (DMA) and distilled water was prepared as follows.

Bleached and damply stored cellulose pulp was added to a mixture of dimethyl acetamide under lithium chloride such that the components were present in the following proportions: 5 parts of cellulose (dry weight), 11 parts of lithium chloride, 82 parts of dimethyl acetamide and (wet Some moisture) from the pulp.

The mixture was homogenized with a high shear force stirrer and heated on a water bath under vacuum until the moisture content of the mixture was less than 3%. Drip sparging of dry nitrogen was used to aid in water removal.

The resulting suspension was cooled to 5 ° C. in the refrigerator and stored at this temperature for one day. Periodic agitation helps dissolve the suspended cellulose. The resulting solution was warmed to 50 ° C. and filtered through a fine sieve.

40 wt% aqueous polydiallyldimethylammonium chloride solution (commercially available product, FLOERGER FL 45 C) was used as the cationic agent.

On the basis of the dissolved cellulose, 10% of the cationic agent (as active ingredient) was added slowly with continuous stirring in undiluted form. Small amounts of water introduced into the solution with cationic agents usually do not interfere with solution equilibrium of cellulose-lithium chloride-dimethylacetamine-water, so that cellulose does not precipitate, but the viscosity of the resulting mixture begins to rise rapidly, Perform the steps immediately.

The resulting mixture with a temperature of 50 ° C. was poured into the vortex zone of the stirred aqueous solution precipitation bath to precipitate the cationized cellulose.

The precipitated fibrous product was filtered out of the mixture through a filter funnel equipped with a fine plastic gauze sieve.

The filtered mixture was shaken in deionized water and then refiltered. This washing process removes residual amounts of salt and DMA from the product.

The product was once again washed with deionized water and filtered. This process was repeated until no further cationicity was detected inside the filtrate.

The wet product (solid content about 12-20%) was removed from the filter and then stored in this state.

Example 18

A cellulose solution dissolved in N-methylmorpholine-oxide (NMMO) was prepared as follows.

Moisture content was analyzed for NMMO / distilled water mixture. This value is usually around 35% at this stage.

Pure cellulose with powder phase was added to the mixture at a level of 3.6 wt% (based on NMMO). This mixture was then placed in a vacuum flask equipped with a stirrer and sparging pipe used to deposit and supply dry nitrogen gas under the liquid surface. The flask was then heated to 95 ° C. in a water bath. A vacuum was applied and the stirrer was started to allow a small amount of nitrogen to bubble through the liquid phase, gradually removing water.

Cellulose dissolves in specific concentrations of water and NMMO (about 88% NMMO). The nitrogen purge and vacuum pump were then stopped. In this experiment, 40% polydiallyldimethylammonium chloride solution (commercially available FLOERGER FL 45 C) was used as the cationic agent.

On the basis of the dissolved cellulose, 10% of cationic agent (as active ingredient) was added to the cellulose solution with stirring in undiluted form. Small amounts of water (about 0.5%) introduced into the NMMO solution by the cationic agent usually do not alter the solution equilibrium of cellulose-NMMO / moisture to the extent that can cause saliva of cellulose.

The resulting mixture was pumped into a water bath through a glass wool-filled filter followed by a spinning jet using a gear-wheel pump, where cationized cellulose aggregated to form fibers.

These fibers were filtered, washed and dried and then cut to a length of about 1 cm.

Example 19

An aqueous solution of 2wt% carboxymethylcellulose (CMC) having a degree of substitution of about 0.55 was prepared and stirred for 1 hour to dissolve the CMC completely.

An aqueous solution of 40% dicyandiamide formaldehyde condensate resin, a cationic agent (Melflock C3, commercially available from SKW Trostberg), was diluted to 4 wt% concentration with distilled water.

1000 ml of the 2% CMC solution was stirred at 800 rpm with a propeller stirrer, then an aqueous solution of 125 ml of the dicyandiamide formaldehyde condensate resin diluted to 4% was added over 10 seconds. This mixture, which already contained precipitated and cationic cellulose, was stirred for another 5 minutes.

The precipitated product was filtered through a filter funnel equipped with a fine plastic gauze sieve, repeatedly dissolved in 500 ml of deionized water and shaken until no significant cationicity was detected in the supernatant and filtered.

During this washing step, residual cationicity, if present, is determined by titration of the aliquots against anionic polymers normalized with a particle charge detector (μTek PCD 02) or by a suitable dye (ortho-toluidine blue) as an indicator. Detected.

The wet product (solid content about 12-20%) was removed from the filter and then stored in this state.

Example 20

The solids content of the cationized cellulose from Example 6 above was measured. Sufficient wet product was taken to give 10 g of dry product and made up to 200 g with distilled water.

This dispersion was transferred to a jock mill and milled at 1500 rpm for 10 minutes. This type of mill is commonly used in paper laboratories to test the grinding properties of fibers in the papermaking process. The above grinding parameters are similar to those used to test the fibers in the papermaking process.

The process was repeated using milling times of 1, 15, 30 and 45 minutes. After measuring the solids content, the ground particles were diluted with 3 wt% of suspension. The wet product (solid content about 3%) was stored in this state.

Example 21

Cationicity of the various products in Example 20 above was determined by titration against standardized 0.001 N polyethylene sulfonate sodium (Na-PES) using ortho-toluidine blue as the endpoint indicator.

Optionally, the cationicity was measured by back titration as follows. The product obtained by the method was mixed with an excess of standardized 0.001 sodium polyethylene sulfonate (Na-PES) and stirred for 1 hour. The solid was then centrifuged and an aliquot of the clear supernatant titrated against 0.001 N polydiallyldimethylammonium chloride (poly-DADMAC) with a particle charge detector. The charge of the product was calculated from the consumption of poly-DADMAC.

Cationicity measured by back titration is usually higher than that measured directly. This can be explained by the fact that the reagents penetrate the cellulose structure and react with less accessible charge carriers due to long residence times during the reverse titration process.

The table below shows the cationicity of the product from Example 6 above as a function of different milling times. It can be seen that the cationicity increases with increasing grinding time, which can be explained by the fact that longer grinding times reduce the particle size and therefore the specific surface area and the available charge.

Grinding Time (min) in Jockey Mill Cationic Charge-Dried Product (μeq / g)

0 251

5 394

10 748

15 911

30 978

45 1027

Example 22

The nitrogen content of the dry product from Example 6 above was measured using the Kjeldahl method.

Nitrogen content for the dried cationic agent from Example 6 above was also measured similarly.

The criterion for nitrogen content was uncationic cellulose precipitated in acid as sodium cellulose xanthogenate. However, the value had a value below the detection limit of this method.

By comparing the amount of cationic agent used and the nitrogen content inside the finished product, the yield of the reaction can be derived. Depending on the choice of cationizing agent, it was usually between 60 and 90%.

Example 23

The solids content of the cationized cellulose prepared from the raw material similar to Example 6 above was measured. Sufficient wet product (solid content 15%) was added to the pulp maker of the Sulzer Escher Wyss P 12 laboratory conical grinding mill to provide 380 g of dry product. Such mills are commonly used in paper laboratories to test the milling properties of fibers in the papermaking process.

The above amount of cationized cellulose was charged to 12.5 liters with distilled water and dispersed for 1 minute. The slurry was then transferred to the mill mill portion of the apparatus, the air trapped inside was removed, the product was pumped through the mill for 5 minutes while continuously circulated and then milled.

During the grinding process the power was maintained at 350 watts by automatic control and the speed of the rotor was 1500 rpm. The grinding energy for treating the cationized cellulose was about 0.08 kW / kg.

The above grinding device is similar to that used for grinding fibers in the papermaking industry.

Grinding of the product was carried out at different times (1, 2, 3, 4, 6, 7, 8, 9 and 10 minutes).

After grinding, the solids content was again measured and the ground product was diluted to 3% concentration and stored in this state.

Example 24

The product from Example 6 above was dried in an oven of hot air at 105 ° C. until the moisture content was between 4 and 9%. In this form, the product can easily be broken into small chunks and the density is comparable to hard bread, which was stored for several hours in this state.

Example 25

The dried product from Example 24 above was wetted with moisture for about 10 minutes and then ground in a mill into a jock for 10 minutes as described in Example 20 above. After the grinding had taken place, the solids content was measured again and the ground product was diluted to 3% concentration and stored in this state.

Example 26

The dried product from Example 24 was ground in a Braun model 4045 coffee mill at the finest setting for 5 minutes in the dry state.

Example 27

The cationized cellulose from Example 6 above was ground for 10 minutes using the procedure in Example 20. The resulting fine solid particles were filtered from the milled slurry on an ultrafine synthetic filter cloth and then dried at 90 ° C. In this state the product can be easily crushed into small chunks, similar to hard bread and stored in this state.

Example 28

The product from Example 20 was run for 5 minutes at 1000 rpm in a laboratory centrifuge. Removed along the upper aqueous phase. If the low kneading compound in the tube had a solids content of about 18%, it was stored in this state.

Example 29

The product prepared in Example 28 was diluted to about 3% with distilled water and stirred gently. Thus, very fine doughy products could be very easily and dispersed in distilled water in a short time.

Example 30

The product prepared in Example 28 was added to a water soluble cationic polyacrylamide solution (FLOERGER FO 4190) as used for dewatering the sludge. In this case, 5% cationized cellulose was added based on the dry weight of the cationic polyacrylamide.

The mixture was stirred slowly. Thus, the product was very easily dispersed in the polyacrylamide solution in a short time.

Example 31

The dried product from Example 27 was added to distilled water to a 3% concentration and stirred for 10 minutes. Thereafter, dispersion was performed in a high shear mixer for 5 minutes to obtain a uniform solution.

Example 32

The product prepared in Example 10 was slowly stirred using a 10 minute grinding time to maintain a uniformly dispersed product. After the agitation was stopped, after 1 hour the cationized cellulose particles appeared to be partially precipitated.

After a few days a precipitate paste was formed, consisting of about half of the liquid volume. As a result of running the stirrer once again, this precipitate could be easily redispersed uniformly in distilled water.

This diluted product with a solids content of about 3% was transferred to the circulation furnace using a diaphragm pump (maximum capacity 23 liters / hour) with ball valves on the suction and discharge sides and appropriate piping with an internal diameter of 16 mm. Pumped. Even after 24 hours of continuous cycling, there was no decrease in pumping efficiency.

Another portion of the dispersed product (as well as having a solids content of 3%) was pumped into the circuit using a small screw feed or Mono pump equipped with a rubber stator for aqueous medium. Even after 24 hours of continuous cycling, there was no decrease in pumping efficiency.

Example 33

Dewatering of Biological Sludge

Cationized water-soluble polyacrylamide-based flocculants (DP7-5636, commercially available from Allied Colloids) used in the prior art for dewatering sludge with cationized cellulose from Example 20 as a 3% dispersion. Used in combination with This promoted the dewatering of biological sludge and enhanced the solids content of dewatered sludge compared to the cationic polyacrylamide flocculant alone.

The sludge used in this field test is derived from integrated sewage in urban / industry and contains a mixture of primary and biological sludge. This sludge was taken from the point between the sludge concentrator behind the anaerobic sterilizer and the final dewatering press before any precipitant / coagulant was applied. Solid content was about 2%.

The standard powdered polymer used in this facility was prepared as an aqueous 0.3 wt% solution. This cationized water soluble polymer was selected as the most suitable product after a series of optimal experiments.

The cationized cellulose was diluted with distilled water to a solids content of 0.3%. This means that any mixture of these two products always has the same concentration of active ingredient.

The following apparatus was used for laboratory testing:

1) The Brit-jar drain test apparatus (see attached schematic) was fitted with a pre-weighed black ribbon filter (Schleicher Schull 589, 100 mm diameter, ash free). A sieve and a precision stirrer were not normally used for dehydration testing in the paper laboratory.

2) A drain tube equipped with an off / on valve was connected to a vessel located on the scale using a flexible silicone tube. The balance is programmed to transmit a signal to the computer for the weight registered at a set time interval and recorded on the computer. The collection vessel was also mounted to the vacuum pump with a flexible tube to adjust the preset vacuum level during the dehydration process.

3) A precision stirrer equipped with a brit-self was installed so that the contents of the 500 ml beaker could be stirred.

4) filter paper (Schleicher Schull 589, black ribbon, 110 mm diameter), dosing syringe, scale, drying oven, etc.

The following measurement procedure was used.

A series of flocculant solutions were prepared by mixing 0.3% cationized cellulose dispersion with 0.3% cationized water soluble polyacrylamide (PAA) flocculant to provide pure cationized cellulose from pure PAA through various mixtures. The concentration of active ingredient was the same in all mixtures.

500 ml of fresh untreated sludge with a solids content of 2% was placed in a beaker and stirred at 200 rpm for 1 minute. Then 15 ml of flocculant was added using a syringe (45 mg). This simulates the dosage actually used.

The sludge thus treated was slowly mixed for the next two minutes. During this time, the vacuum pump was run to stabilize the vacuum. The filter paper inside the brit-self was run down and the balance zeroed.

130 ml of aggregated sludge from the beaker was added to the bridging ego to form a sludge layer about 1.5 cm deep. The valve between the brit-self and the collection vessel was opened and data transfer from the balance to the computer was initiated.

Thus, the filtrate weight in the collection vessel was automatically recorded during the dehydration process. In the case of poor dehydration, such as by stopping the inflow of liquid into the collection vessel and stopping the air entering through the sludge into the collection vessel, the sludge is completely dehydrated or the filter is blocked by fine material. , The experiment was stopped. The sludge remaining on the filter was tested for solids content. The filtrate was tested for turbidity and chemical oxygen demand (COD).

The process was repeated for the various flocculants. The results for the filtrate weight for each of the flocculants used are plotted against time. For each flocculant used, the turbidity and COD of the filtrate as well as the dry matter content were tabulated.

result:

Dewatering Rate of Sludge Dewatering of Biological Sludge to Various Levels of Cationic Cellulose Used in Combination with Polyacrylamide—Weight of Filtrate at Various Times Coagulant system for sludge dewatering test as a percentage of specific components % Cationized cellulose 0 0 One 2 4 6 8 10 50 100 % Cationized polyacrylamide 0 100 99 98 96 94 92 90 50 0 Dehydration time (minutes) Weight of filtrate over time (g) One 5 31 37 48 50 31 32 27 25 8 2 5 48 50 55 57 46 45 39 30 10 3 7 54 56 62 67 50 47 44 31 10 4 8 58 61 69 75 52 51 46 35 15 5 10 64 67 73 76 55 53 46 37 17 6 10 67 69 75 80 58 57 53 42 20

Solid content of dehydrated sludge Dewatering of Biological Sludge to Various Levels of Cationized Cellulose Used in Combination with Polyacrylamide-Solid Content of Dehydrated Sludge Coagulant system for sludge dewatering test as a percentage of specific components % Cationized cellulose 0 0 One 2 4 6 8 10 50 100 % Cationized polyacrylamide 0 100 99 98 96 94 92 90 50 0 Solid content of dehydrated sludge (%) * 19.6 20.8 22.7 24.2 21.9 21.5 21.0 16.1 * Note: Samples marked with * could not be dehydrated in a timely manner because the filter was clogged with fine material.

Turbidity and COD of the filtrate Dehydration of Biological Sludge to Various Levels of Cationic Cellulose Used in Combination with Polyacrylamide-Turbidity and Filtration of Filtrate Coagulant system for sludge dewatering test as a percentage of specific components % Cationized cellulose 0 0 One 2 4 6 8 10 50 100 % Cationized polyacrylamide 0 100 99 98 96 94 92 90 50 0 Chemical oxygen demand of the filtrate (mg O ₂ / l) COD mg O ₂ / l 1580 1080 1060 980 970 1000 1040 1050 1400 1590 Turbidity of the filtrate (FNU) Turbidity FNU +450 405 400 388 364 393 402 415 +450 +450

Substitution of about 4% of the water soluble cationic polyacrylamide with cationized water insoluble ground cellulose particles resulted in a significant increase in the solids content of the dehydrated sludge and the turbidity and chemical oxygen demand in the filtrate. At the same time, the sludge was dehydrated at an excellent and significant increase.

Example 34

Dewatering of Primary Sludge

The same test procedure as in Example 33 above was used for this sludge except for the following differences.

The cationized cellulose used was prepared in Example 7 using poly-DADMAC as the cationic agent, and the cellulose was ground for 10 minutes by the procedure described in Example 20 above.

The sludge used in this experiment was taken from an industrial mechanical wastewater plant, in which the wastewater is usually deposited and precipitated, the precipitate is concentrated in a sludge concentrator, and then treated with a water-soluble cationic polyacrylamide, followed by a band Dehydrate in the press.

The standard product used in such plants is known under the product name Floerger FO 4190. The sludge used for laboratory testing was also taken at the point between the sludge thickener and the band press before any flocculant was added. This sludge had a solids content of 2%.

Weight of filtrate during dehydration time Dewatering of Biological Sludge to Various Levels of Cationic Cellulose Used in Combination with Polyacrylamide—Weight of Filtrate at Various Times Coagulant system for sludge dewatering test as a percentage of specific components % Cationized cellulose 0 0 One 2 4 6 8 10 50 100 % Cationized polyacrylamide 0 100 99 98 96 94 92 90 50 0 Drainage time (minutes) Weight (g) of filtrate from dewatering of sludge 0.5 8 21 22 23 25 26 25 21 18 12 1.0 12 37 40 42 43 44 41 31 24 17 1.5 14 49 52 55 57 58 52 42 30 19 2.0 15 54 56 60 64 67 60 49 35 21 2.5 18 57 58 63 67 72 63 54 40 23 3.0 20 59 60 66 72 76 69 59 46 24

Solid content of dehydrated sludge Dewatering of Biological Sludge to Various Levels of Cationized Cellulose Used in Combination with Polyacrylamide-Solid Content of Dehydrated Sludge Coagulant system for sludge dewatering test as a percentage of specific components % Cationized cellulose 0 0 One 2 4 6 8 10 50 100 % Cationized polyacrylamide 0 100 99 98 96 94 92 90 50 0 Solid content of dehydrated sludge (%) * 32.1 33.8 34.4 37.6 42.3 38.5 35.2 27.6 23.1 Note: Samples marked with * could not be dehydrated in a timely manner because the filter was clogged with fine material.

Turbidity and COD of the filtrate Dehydration of Biological Sludge to Various Levels of Cationic Cellulose Used in Combination with Polyacrylamide-Turbidity and Filtration of Filtrate Coagulant system for sludge dewatering test as a percentage of specific components % Cationized cellulose 0 0 One 2 4 6 8 10 50 100 % Cationized polyacrylamide 0 100 99 98 96 94 92 90 50 0 Chemical oxygen demand of the filtrate (mg O ₂ / l) COD mg O ₂ / l 1250 890 880 810 740 790 870 880 1120 1150 Turbidity of the filtrate (FNU) Turbidity FNU +450 320 308 285 252 267 312 338 401 449

Substitution of about 6% of the water soluble cationic polyacrylamide with cationized water insoluble ground cellulose particles resulted in a significant increase in the solids content of the dehydrated sludge and the turbidity and chemical oxygen demand in the filtrate. At the same time, the sludge was dehydrated at an excellent and significant increase.

Example 35

Flocculant in Wastewater Treatment

The wash water from the paper coating apparatus preferably contains anionically charged latex, which preferably causes a persistent problem as an interference material when such wash water is reused in papermaking. Typically, it is necessary to agglomerate such wash water by neutralization so that it can be reused as a dilution water in a papermaking machine or sent to a wastewater purification plant.

Coagulants generally used for this purpose are based on water soluble highly cationic polymers or polyvalent cationic metal ions, or a combination of the two.

This example shows how a cationized cellulose removes anionic colloidal material from water. As a result, the precipitation of these components is also enhanced by treatment with conventional chemicals.

The wastewater from the paper coating machine was taken fresh. By titration with the μTek PCD-02 titration system, the charge with high anionicity was measured. Turbidity and chemical oxygen demand were also very high.

As a control, a sample treated with a standard precipitant [polyaluminum chloride (PAC)] and then aggregated into two types of water-soluble polyacrylamide (anionic + cationic) was used.

On the basis of the drying of the polyacrylamide, about 10% of cationized cellulose was added to the wastewater sample and mixed for a fixed time. Then, the amount of PAC commonly used was added and the amount of polyacrylamide was reduced by the weight of the added cationized cellulose (= 90% of the standard amount).

The wastewater thus treated was poured into a calibrated graduated cylinder and left for 1 hour.

Thereafter, the volume of the sludge was measured. Lower volumes indicate higher, and therefore more preferred sludge density. Turbidity and chemical oxygen demand were also measured. Since such water is usually reused as process water or sent to a wastewater purification plant, low turbidity and COD are preferred.

Sediment volume, turbidity and COD Application of Cationized Cellulose to Agglomeration and Sedimentation of Wastewater in Paper Coating Equipment. Analysis of sediment inside 100 ml graduated cylinder Coagulation / Coagulation System Used Volume of precipitate after 1 hr. ml Turbidity of the supernatant FNU COD O ₂ / ml of supernatant none 30 (poor separation of sediment) +450 1640 PAC + PAA (cationic) 12 44 260 PAC + PAA (anionic) 14 36 290 Cationic cellulose + PAC + PAA (cationic) 10 35 230 Cationic Cellulose + PAC + PAA (Anionic) 10 33 220

Surprisingly, compared to the levels obtained with standard systems, pretreatment of wastewater with cationized cellulose clearly improves precipitation and turbidity and COD. This preferred result was also detected in combination with cationic and anionic PAA.

Example 36

Paper manufacturing

Cationized cellulose from Example 6 above was ground for 10 minutes and diluted with 3% suspension as in Example 20. By using this product as an alternative or additional component for paper holding systems in laboratory test equipment, various improvements have been made to the papermaking process.

Retention / Fix

Britt-ego drainage tester was used.

Part 1) Application to fine paper stock without wood

In the first part of this embodiment. Synthetic adjuvant was prepared from a mixture of pulverized short, long fibers and natural calcium carbonate filler. This thick raw material was diluted, the conductivity was adjusted by adding salt, and then the pH was adjusted to neutral. The raw materials have a negative charge when filtered, due to dissolved or colloidally dissolved material (anionic waste).

These negative charges are measured as cation requirements and results by titrating aliquots of the filtrate against standardized cationic polymer (0.001N polyethylene imine) in a particle charge detector, or by using a suitable color indicator such as ortho-toluidine blue as the endpoint indicator. It was.

A series of drainage tests were performed using various retention systems and replacing the individual components of this system with the above cationic cellulose. This drainage test was performed while operating a brit-ego stirrer.

In tests using cationized cellulose as part of the retention system, this component was added before the second component, the water soluble polymer. The second component was added just before the start of the dehydration process.

The brit-ego filtrate (A) was filtered through pre-weighed ash free filter paper to test for solids content giving a second filtrate (B). The filter paper was ashed to determine filler retention. The second filtrate was tested for chemical oxygen demand (COD), turbidity and residual negative charge or cation demand as described above.

A series of these experimental results are shown in Table 8 below.

Effect on total retention, filler retention, etc. of cationized cellulose mixed with a water soluble polymer. Brit-Ego Trials-Woody Fine Support, Carbonate Filler, Neutral Conditions Britt-Ego Filtrate Brittle-ego filtrate after filtration Total solid g / l Filler amount g / l Turbidity FNU CSBmg O ₂ / l Cationic Requirementsmg PSK / l Retention promoter system FNU mg O ₂ / l mg PEI / l No retention promoter (blank) 2.03 1.14 445 1060 49 0.6% Cationic Polyacrylamide 1.71 1.17 294 810 9.6 0.3% Cationic Polyacrylamide + 1.0% Bentonite 1.59 1.22 432 790 18 0.3% cationized cellulose + 0.3% cationized polyacrylamide 1.34 0.95 297 770 8.7

Part 2) Application to Refining Fees Containing Lumber Pulp / De-Ink

In the experiment of Part 2, the paper stock was taken as a thick stock directly from the mixing vessel of the paper machine. This raw material contains crushed wood pulp, deinked pulp and a small amount of pulp fibers together with porcelain clay as filler, which was diluted to a concentration of 1%.

The same test procedure as described above was conducted for this raw material. At this time, water-soluble polyethylene imine was used as the standard retention aid for the brit-ego drainage test. Similarly, the polyethylene imine described above, which is a standard retention aid for the related papermaking apparatus, was partially substituted with cationized cellulose.

The results of a series of these experiments are shown in Table 9 below.

Effect on total retention, filler retention, etc. of cationized cellulose mixed with a water soluble polymer. Brittle-Ego Test-groundwood pulp / deink pulp / woody blended raw materials, clay fillers, pseudo-neutral conditions Britt-Ego Filtrate Brittle-ego filtrate after filtration Total solid g / l Filler amount g / l Turbidity FNU CSBmg O ₂ / l Cationic Requirementsmg PSK / l Retention promoter system FNU mg O ₂ / l mg PEI / l No retention promoter (blank) 8.8 6.2 237 345 41 0.6% polyethylene imine 7.1 5.3 128 242 25 0.3% cationized cellulose + 0.3% polyethylene imine 6.6 5.0 94 226 21

Retention of fine materials, including fillers, as a result of the replacement of a portion of the water soluble cationic polymer (polyacrylamide as in Example 1 or polyethylene imine as in Example 2) with cationized water insoluble ground cellulose particles A significant increase in was observed in the second filtrate, with reduced turbidity, reduced chemical oxygen demand and anionicity, and thus a marked reduction in dissolved and colloidally dissolved anionic waste. This improvement has, of course, a very important meaning in the paper manufacturing process.

dehydration

Part 3) Application to papermaking fee (woody fine paper)

In the second experiment, a larger diameter outlet was fitted to the brit-self so that the discharge rate of the raw material could be directly measured as a function of the feedstock, preparations were used and sieves. During this modified Britt-Ego process, the filtrate was collected internally on a dragon placed on an electronic balance. The balance was programmed to transmit a signal to the computer for the weight registered at a set time interval so that the dehydration curve of the filtrate weight over time can be recorded.

The results of these tests are shown in Table 10 below. The percentage of retention / dehydration system represents the dry weight of the retention aid relative to the dry weight of the paper stock.

Dehydration of Neutral Paper-making Papers Filled with Carbonate without Carbonate Time measured until a constant volume is reached, sec 50 ml 100 ml 150 ml 200 ml Retention / Dewatering System Dehydration time (seconds) No retention system 47 125 235 312 0.06% cationized polyacrylamide (PAA) 13 38 87 141 0.03% cationized cellulose + 0.03% cationized PAA 9 22 52 117

As a result of replacing some of the commonly used water-soluble cationized polymers (in this case polyacrylamides) with water-insoluble cationized and pulverized cellulose particles, there is a surprisingly significant difference in the dehydration rate for these paper stocks. An increase was shown. This means that, when applied to a paper machine, it can increase the speed and thus the paper production.

Example 37

Cationized cellulose from Examples 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 25 and 31 is a water-soluble polymer retention system in the papermaking process. Was used as some substitute for and the results were compared with each other. As a control, polymer alone and blanks were used, including cellulose prepared using the procedure of Example 7 but without adding any cationic agent.

Each product was ground for 10 minutes by the grinding process of Example 20 and used as 3% sludge.

Experimental method was used in the same manner as in part 1 of Example 36. Each product was added at a standard concentration of 0.4% cationized cellulose with 0.2% water soluble polyacrylamide as the retention aid system. In addition, the papermaking raw material was the same as in Example 36, 1 part.

The results are shown in Table 11 below.

Brit-ego-Comparison of various cationized cellulose products. The retention capacity is expressed as the amount of solids inside the filtrate of the brit-ego. Cationized Cellulose Product Used-Example Number Total amount of solids in the brit-ego filtrate g / l Nothing used (blank) 4.42 Uncationic cellulose 4.35 100% polymer-no cationized cellulose 3.01 6 2.42 7 2.72 8 2.66 9 3.00 10 3.21 11 2.56 12 2.90 13 2.87 14 2.58 15 2.77 16 2.94 17 2.80 19 2.91 25 2.70 31 2.87

In this brit-ego experiment, the retention was always higher with cationized cellulose compared to the polymer alone. This effect was not detected when cellulose was not cationized.

Example 38

This example shows that by replacing part of the conventional retention system with cationized cellulose, it is possible to maintain or enhance the strength of the paper sheet while having a weighted filler content. This is very important because the increased amount of filler generally reduces the strength of the paper.

Paper sheets were prepared using a laboratory sheet generator. The paper stock used was essentially similar to that used in part 1 of Example 36 above, ie a mixture of short, long fibers without wood containing calcium carbonate filler.

The cationized cellulose is the same as that from Example 7, which had a poly-DADMAC as the cationic agent and was subjected to a 10 minute grinding as described in Example 20 above.

A series of paper sheets were prepared using various retention systems, and some of these retention aids were replaced with cationized cellulose as described above.

Characteristics of Paper Made with a Lab Sheet Generator Woodless, carbonate-filled refill. Neutral condition Holding system Grams of papermaking g / ㎡ Volume of filler% Porosity ml / min Destruction length km none 65.1 2.2 2280 5.9 0.2% cationized PAA + 1.5% bentonite 66.5 13.1 2710 4.4 0.6% cationized PAA 67.4 13.9 2850 4.3 0.4% cationized cellulose (Example 7) + 0.2% cationized PAA 67.0 15.4 2980 4.4

Example 39

Fixing Agent for Anionic Waste in Papermaking Process

In order to treat a sample of papermaking fiber stock of groundwood pulp to fix anionic waste, the product of Example 14 ground for 10 minutes was used as described in Example 20 above.

Taken as about 4% of the papermaking aid directly from the incoming fiber flow to the papermaking machine, this papermaking material has a relatively high level of soluble and colloidally soluble material based on lignin which interferes with the papermaking process, especially the holding system. Contains anionic waste.

The efficiency of the cationized cellulose as a waste trapper was compared with an inorganic cationic fixative (polyaluminum chloride from Ekokemi) and an organic water soluble cationic polymer (Catiofast SL from BASF).

In addition, it has been found that the overdose of the conventional fixing agent causes excessive cationization of the water circuit of the papermaking apparatus, and thus may adversely affect the holding force.

Cationic cellulose was added to 500 ml of groundwood pulp support material and mixed for 5 minutes. Subsequently, the backfill of the treated wood pulp was filtered through a Schleichern Schull 589 black ribbon filter in vacuo, and the turbidity, chemical oxygen demand, and cation demand were tested for the filtrate.

These anion charges are measured as cation requirements and results by titrating aliquots of the filtrate against standardized cationic polymer (0.001N polyethylene imine) in the particle charge detector, or by using an appropriate dye such as ortho-toluidine blue as the endpoint indicator. It was. For excess cationized filtrate, standardized anionic polymer solution (0.001 N Na-PES) was used.

From these first experiments, the cation demand of the groundwood pulp feedstock was calculated according to the fixer used, and then twice the specific amount required. The degree of excess cationization for the filtrate was calculated by titration and is shown in the table below as a negative cation demand.

Anionic Garbage Settled in Wood Support Fixative Addition to solids% dry / dry Turbidity of the filtrate CODmg O ₂ / l of filtrate Cation demand of the filtrate mg PSK / l Blank-None 0 268 328 57.5 Polyaluminum Chloride (PAC) 0.3% 220 312 49.7 PAC-Overdose (2x Neutral) 3.5% 262 326 -18.8 Catiofast SL (organic polymer) 0.05% 165 302 40.2 C. SL-overdose (2x neutral) 0.33% 191 366 -27.5 Cationized cellulose 0.1% 171 305 47.9 Cationized Cellulose-Overdose (2x Neutral) 1.2% 167 278 1.3

The cationized cellulose from Example 14 exhibits not only an excellent ability to fix anionic waste compared to conventional fixatives, but also due to its water insoluble properties, excess cations in the filtrate when addition of water soluble products occurs It has the advantage of not causing anger.

Example 40

Dyeing Behavior of Cationic Cellulose Thread

In a dye bath with a concentration of Orange II of 5 g / l, the cationic cellulose according to the invention of Example 6 or optionally uncationic cellulose from the xanthogenate process was stained. Pine nuts were used as the yarn with 3 dtex. The dye bath ratio was 1: 6. Staining was carried out at room temperature for 30 minutes. After removing the spent dye bath, it was washed again with demineralized water and drying was performed.

Measurement result:

Absorbance of the spent dye bath Whiteness ISO

1: 100 dil. L A B

Blank value 0.3

Uncationic 1.732 15.40 71.96 +38.97 +42.73

cellulose

Cationized 0.461 1.38 37.74 +51.23 +44.58

cellulose

Elrepho 2000 is used for whiteness / color position measurements.

Preparation of Samples:

The dried yarn was wound as evenly as possible on a 30 mm wide cardboard strip. The winding thickness must be large so that no change of measurement occurs through the cardboard surface.

The fibrous material consisting of cationized cellulose during the cleaning of the samples was found to have a much higher color flatness compared to the uncationic quality.

Claims (41)

In the cellulose particle which has a cationic group, A cellulose particle, wherein the cationic group is also present inside the particle. The method of claim 1, At least 10%, preferably at least 50% of the cationic groups are present in the interior of the particles. The method according to claim 1 or 2, The cation group inside the cellulose is fixed, characterized in that the cellulose particles. The method according to any of the preceding claims, The cation group is a cellulose particle, characterized in that covalently bonded to the cellulose. The method according to any of the preceding claims, Cellulose particles, characterized in that the concentration of the cation group inside the particle is constant or increases from the outside to the inside. The method according to any of the preceding claims, At least one cationic group per 100 anhydroglucose units of cellulose. The method according to any of the preceding claims, The cellulose particles are characterized in that they have an average particle diameter of 0.001 to 10 mm, in particular 0.1 to 1 mm. The method according to any of the preceding claims, The cellulose particles are present in combination with the water-soluble polymer. The method of claim 8, The cellulose particles are present in combination with a water soluble and cationic polymer. The method according to claim 8 or 9, The cellulose particles are present in combination with polyacrylamide. A method for producing the cellulose particles according to any one of the preceding claims, wherein the cellulose is subjected to a cationic agent reaction. The method of claim 11, The cellulose starting material used is an unsubstituted pulp, cellulose ester or ether, carboxymethyl cellulose, hydroxyethyl cellulose and sulfated cellulose, cellulose acetate, chitosan or alkali cellulose. The method according to claim 11 or 12, The reaction is carried out as a solid reaction. The method according to any one of claims 11 to 13, Wherein said cellulose is an alkali cellulose mixed for reaction with a cationic agent. The method according to claim 11 or 12, Dissolving the cellulose with the cationic agent and precipitating the cationic and dissolved cellulose into the cellulose particles. The method according to any one of claims 11 to 15, The solvent used for cellulose is N-methylmorpholine-N-oxide, lithium chloride dimethylacetamide, and in the case of a water-soluble cellulose derivative, it is water. The method according to any one of claims 11 to 16, The cationic agent used is an aluminum salt, cationic polyelectrolyte or reactive monomer. The method of claim 17, The weight ratio of the aluminum salt or cationic polyelectrolyte with respect to the cellulose is 0.03: 1 to 1: 1. The method of claim 17, Wherein said reactive monomer reacts with cellulose at a rate such that the degree of substitution is no greater than 0.2. The method of claim 17, The aluminum salt used is a polyaluminum chloride or an alkali aluminum acid salt. The method of claim 17, The cationic polymer electrolyte used is polydialkyldiallylammonium chloride, dicyandiamide, dicyandiamide condensate, polyamine or ionene. The method of claim 17, The reactive monomer used is characterized in that each is a primary amine, secondary amine or tertiary amine or quaternary ammonium salt having at least one residual group which reacts with the OH group of cellulose. The method of claim 22, And wherein said reactive residual group is a halogen, epoxy group or imino group. The method of claim 23, The reactive monomer is a 2-chloroethane trimethylammonium salt or propoxytrimethylammonium salt or a mixture thereof. The method of claim 15, When dissolved with the cationic agent, the dissolved cellulose is present at a concentration no greater than 10 wt%, preferably at a concentration of 0.5-4 wt%. The method of claim 15, Wherein said dissolved cationic cellulose is regenerated in a precipitation bath. Use of the cellulose particle of any one of Claims 1-10 as a papermaking manufacture. Use of the cellulose particles according to claim 27 as a means for fixing interfering substances in papermaking present in the water circuit during the papermaking process. Use of the cellulose particles of claim 27 as a means for retaining fine material within the paper during the papermaking process. Use of the cellulose particles according to claim 27 for enhancing the strength of paper during the paper making process. Use according to any one of claims 27 to 30, provided that 0.1 to 10 kg of cellulose particles (absolute dry weight basis) are used per ton of paper stock. Use as a flocculant of the cellulose particle of any one of Claims 1-10. Use according to claim 32 as a flocculant for wastewater purification. Use of the cellulose particle of any one of Claims 1-10 characterized by using a cellulose particle in combination with a water-soluble polymer. The method of claim 34, wherein Use of cellulose particles, characterized in that the cellulose particles are used in combination with a water soluble and cationic polymer. The method of claim 34 or 35, Use of cellulose particles characterized by using cellulose particles in combination with polyacrylamide. The method according to any one of claims 34 to 36, The cellulose particles are used for sludge drying in combination with the water soluble polymer in an amount of 1 to 10 wt%, especially 3 to 5 wt%, based on the water soluble polymer. The method according to any one of claims 34 to 36, Use of the cellulose particles in the manufacture of papermaking in combination with the water-soluble polymer in an amount of 40 to 60wt% of the cellulose particles based on the water-soluble polymer. The method according to any of the preceding claims, The cellulose particles are characterized in that the cellulose particles present in the form of fibers. The method according to any of the preceding claims, The fibrous cellulose particles are cellulose particles, characterized in that dyeable with anionic dyes. Use of the fibrous cellulose particles according to any one of the preceding claims for industrial and textile applications.