DE1621699A1 - Papermaking process - Google Patents

Description

P 16 21 699.2-45
Nalco Chemical Company

copy

Papermaking process

The invention relates generally to an improved papermaking process, and more particularly to a process To increase the drainage rate of the water from the pulp fiber in the formation of paper, it was found that a combination of an aluminum ion source, such as alum, a cationic component and an anionic polymer the speed, with which the water runs off the paper web, increases considerably without affecting the properties of the paper unfavorably to influence.

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It has been found that the speed at which paper can be made is directly related to the runoff speed of the water from the aqueous suspension of the paper fibers. A paper machine can only produce paper as quickly as the wet web is removed from the machine. When this wet web too is pulled off the machine quickly, the web breaks, resulting in a relatively large loss of time. This problem is not particularly severe in the manufacture of tissue paper or other lightweight papers, but it is especially important with heavier paper

2 or cardboard with a basic weight over 13 »60 kg per 6.4-5 m

The paper industry is therefore very keen to reduce this drainage or to increase the running speed and thereby make the entire papermaking process more efficient. It has been found, for example, that with less refined paper pulp, the wet web has a larger one Has strength and therefore better drainage properties so that faster working machines can be used. However, if the pulp is not up to one is refined to a sufficient degree, the result is a paper which has insufficient dry strength. As a result, if to increase the machine speed a little

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ger fine pulp is used, the quality of the paper suffer and this becomes bad and often unusable.

To this unfavorable effect the less refined To counteract pulp's dry strength, attempts have been made to make the paper by chemical means to enhance. In some cases, however, the artificially created strength becomes of undesirable side effects that make the paper brittle or less resistant to creasing and / or creasing. It is also occasionally used by the dry strength treatment the drainage or drainage speed is unfavorable which in turn reduces the speed at which the paper can be produced will. Another factor that makes paper making difficult is the use of various fillers, pigments, glue additives, etc., which are often the drainage or Influence the drainage speed unfavorably.

A process in which the rate of drainage of the aqueous suspension of the paper fibers is increased significantly allows a greater machine speed and allows a finer pulp to be used, so that Better ^ quality paper can be produced.

The object of the invention is to create a method in which the drainage rate from a suspension

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BATH ORIGINAL

Pulp fiber is significantly increased, with the pulp can be refined much better before it is used for papermaking, without undesirable side effects, such as loss of moisture resistance and slower drainage rates occur.

The invention relates to a process in which the aqueous suspension of the paper pulp is added prior to papermaking one after the other a cationic component, consisting of an aluminum ion source and a cationic substance, such as a cationic polymer, cationic starches and cationic rubbers, and then an anionic high molecular weight polymer can be added. According to a preferred embodiment certain cationic compounds and anionic polymers are used.

The first component in the process according to the invention used involves a double treatment with an aluminum ion source, such as alum, and a cationic one Material consisting of a cationic polymer, starches or types of rubber, which is used in the following for the sake of simplicity referred to as a cationic compound. The cationic compound and the aluminum ion source can be added together or separately in any order. In the usual paper production

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8AD ORIGINAL

the alum or other aluminum ion donor is usually given in the Hollander to the pulp and therefore this compound is preferably added first. Any commercially available aluminum ion donor such as alum, aluminum chloride, sodium aluminate, and the like can be used. I ^{1 For} the method according to the invention, 0.2 5 % aluminum ion donors, calculated on alum and based on the dry fiber weight, are usually sufficient. The preferred amount of this additive is about 0.5-1.5%.

The second part of the first component is a cationic one Compound selected from cationic polymers, cationic starches and cationic rubbers can. In papermaking, cationic starches are known additives and are used for various purposes, such as increasing the dry strength. Cationic In general, starches are all starches that have been modified to give them cationic properties »

As used herein, the term "starch" includes all natural starches as well as dextrins and various rnodir · fied * to understand strengths and strength derivatives. Examples

f.

of natural starches are grain starch, potatoes, tapioca, waxy maize, wheat, wheat and the like. Modified starches and starch derivatives are acid-modified hypachlorite-oxidized and enzyme converted starches and the acetates and ethers of starch.

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There can be numerous connections to modify Starch can be used to impart cationic properties. However, polyamines are preferred. With the help of These can be converted by simply boiling raw starch take place in the presence of the polyamine, with a cationic starch solution is formed. A particularly useful one polymeric polyamine is a reaction product of an alkylene dihalide with an amine and has the general formula

wherein H is an alkylene radical from the group

GH _x ³

, -OH ₂ OH ₂ CH ₂ - and - ₂

GH,

and χ represent an integer from 0-5.

Similarly, cationic gummies can be made. Numerous simple and inexpensive rubbers can be treated with polymeric polyamines to create a superior papermaking additive. Suitable for this purpose rubbers are, for example, Irish moss, tragacanth, dextrin, Veegum, carboxymethyl cellulose, locust bean gum, Shirazgummi "Zenzibargummi _t karaya, agar agar! Frankincense, benzoin, Gambier, Jaguar, psyllium seeds, rubber

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arabic, acacia, senegal, algin, British. . Gum, flaxseed, ghatti, guar, Iceland moss, quince * - ·, seeds and other readily available types of rubber. Guar and locust bean gum are particularly preferred.

After the reaction of the rubber with the polymeric amine, there is a relatively dilute aqueous suspension which contains 1-40% by weight, preferably 1-30% by weight, of the reactants. The ratio of polymers! Amine to rubber is such that 1-40 % polymeric amine, preferably 1-30% * based on the weight of rubber, is present.

Other polyamines that for the conversion of the starches to cationic products that are suitable for modifying starches are: polyethyleneimine, Polyäthylenamin, condensation polymers of Alkylenpolyhalogeniden as Ithylendi chloride and ammonia, or Polystickstof £ containing bases, and addition polymers which are derived from Derive monomers with basic nitrogen groups, such as dimethylaminoethyl methacrylate, 2-vinylpyridine or substituted allylamines. Amines such as i-trimethylamino-2,3-epoxypropane or: 1-dimethylamino-2-chloroethane should also be mentioned. A particularly suitable cationic starch is commercially available ^{under the trademark tt} Q-tac ^M.

■ ♦. t

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Numerous are suitable for the process according to the invention various cationic polymers. They generally have a molecular weight in excess of 1000, preferably greater than 2000. The most preferred molecular weight range is 2000-50,000. These polymeric polyamines can be prepared by various processes, for example by reacting with alkylene polyamines bifunctional alkyl compounds.

A particularly suitable class of polyamine polymers are the condensation polymers of alkylene polyamine and Halohydrins such as those described in U.S. Patent 2,969 are described.

This includes the polyamine condensation polymer, the is defined as an aqueous solution containing 5 - 40% by weight of a high molecular weight epihalohydrin-alkylenepolyamine condensation copolymer and a viscosity of at least 10 cp, measured as an aqueous solution with % By weight of the condensation copolymer at 23.90 ° 0, having. Preferred compounds that fall into this class have - measured under the stated conditions a Viscosity of at least 50 cp. The upper limit of the viscosity is just before gel formation. The on The most suitable products have viscosities of around 50 800 cp. For the preparation of the preferred according to the invention

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Polymers only need epihalohydrin and alkylenepolyamine at temperatures of about 40-85 ° C at a Molar ratio of epihalohydrin to alkylene polyamine of 1.4: 1 to 2.2: 1 are polymerized. Best results are obtained in aqueous solutions at a concentration of the reactants of about 10-30% by weight.

As already stated, for the condensation polymerization uses two classes of monomeric reactants, namely epihalohydrins and alkylene polyamines. to the epihalohydrins include epichlorohydrin, epibromohydrin and epiiodohydrin, of which because of the low cost and epichlorohydrin is particularly preferred for availability.

The alkylene polyamines include known compounds of general formula

where η is an integer from 1-4 and χ is 1 or more. The compounds with η 3 2 and χ 3 1 - 5 are particularly useful. Examples of such alkylene polyamines are the alkylenediamines, such as ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine and polyalkylenepolyamines, such as, for example, diethylenetriamine, triethylenetetramine, tetraethylene pentamine, pentaethylene hexamine, Dipropylene triamine, and the like polypropylene polyamines and polybutylene polyamines. Mixtures of these compounds mentioned can '

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are used and often contain the commercial ones Products of two or more of these alkylene polyamines. Some these commercially available mixtures contain up to five individual compounds.

Another group of polyamines falling into the above class is made by reacting alkylene dihalide made with an amine. Preferred amines for this purpose are ammonia, ethylenediamine, diethylenetriamine and tetraethylene pentamine and triethylenepentamine, of which ammonia because of its excellent reactivity and its low reactivity Cost and availability is particularly preferred. The alkylene dihalide can be selected from a number of bifunctional organic compounds can be selected and can, for example Ethylene dichloride or 1,2 propylene dichloride. Ethylene dichloride is particularly preferred. One for The cationic polymer, which is excellent for the process according to the invention, is formed in the reaction of ammonia with ethylene dichloride under pressure and heating.

In addition to the abovementioned condensates, there are numerous other cationic condensation products for the condensation products according to the invention Exceptionally well suited for purposes. Effective water-soluble cationic polymers or resins are among the amine aldehyde resins and amide aldehyde resins, preferably the hydrophilic melamine-formaldehyde resins. Such colloidal cationic resin solutions can by

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Dissolving common melamaldehyde condensates such as methylolmelamines in acids such as hydrochloric acid to form acidic or acidic resin solutions having a glass electrode pH of about 0.5-3-5 »measured at 15 % solids. The pH of more dilute solutions is up to 4.5 »This solution is aged to a colloidal state, as described in US Pat. No. 2,34-5,543.

Another class of cationic melamine aldehyde resins are the resinous polymers of melamine, urea and aldehydes, such as formaldehyde, consisting of at least 0.7 moles of melamine for 4 moles of urea and about 1-4 moles of combined formaldehyde per mole of melamine plus urea. Such resins are disclosed in ITS Patent 2,485,079. These cationic melara resin mixture polymers are obtained by first adding an acidified aqueous solution of an aldehyde condensate composed of melamine and urea, consisting of 1-70 mol # urea and 30-99 ° / ° melamine and about 0.2-1.5 mol acid per mole of melamine, depending on the strength of the acid, is produced and then the solution is aged until the colloidal cationic state is reached *

Also, the polyimine compounds can according to the invention can be used. These are, for example,

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1621639

polymerization of monomers that form the imine residue -N-

hold, formed and have a molecular weight of at least 1000.

The imine monomers used preferably contain more than 7 carbon atoms. The most suitable monomers are which can be referred to as substituted ethyleneimines and have the general formula

R ¹ R "

Il _R _0 - GR

wherein R, R. ¹ , R "are either hydrogen or acylic hydrocarbon radicals having 1-3 carbon atoms.

Examples of such monomers are:

A. Ithylenimine -. H ₀ O --- 0H ₀

.2 \ _N / d

B-. 1,2-propyleneimine - H

0. 1,2-butyleneimine H

H ₂ O-OH ₀ -O 0H ₀

3 2 ν «/ '2

D. 2,2-Dimethylethyleneimine -

j., Ο — Ο— ~ ΟΗλ

⁵ V- ²

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E. 2,3-Butylenimine -

γ - H - 1621699 H H H CH,
I 3

F. 1,1-dimethyl, 2-n-propyl-

ethylene / min - GH ₅ -GH ₂ -GH ₂ -G ^ ---, G-GHi

Others for manufacture for the purposes of the invention suitable cationic polymers are trimethytenimine with the general formula:

and its lower alkyl substituted derivatives in which one or more hydrogen atoms bonded to a carbon atom by an alkyl group with no more than 3 carbon atoms, e.g. methyl, ethyl and propyl are substituted.

Ethylenimine and many of its derivatives can be a known procedure. Such procedures are described in "Journal of American Chemical Society", vol 57, page 2328 (1935) and Ber. 2h 1094 (1888).

The polymerization of ethyleneimine and its derivatives takes place usually at lower temperatures using acidic catalysts such as HCl and the like .. the polymerization of the various monomers listed above is in one

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its ixt "Journal of Organic Chemistry", Volume 9, page 500 (1944).

The linear polyimines are by a long acyclic Chain in which nitrogen atoms of imine groups are connected to carbon atoms at intervals. It can therefore be seen that linear polyimines not only by homopolymerization, but also by condensation can be prepared with the elimination of a hydrogen halide. So can ethylene dibromide or propylene dibromide with diethylenetriamine, triethylenet et ramin, tetraethylene pentamine and / or dipropylenetriamine are condensed to form polyimines. According to the invention, such products used.

In general, those used according to the invention can be used Polyimines are referred to as water-soluble polyimines in which imino (-1JH) groups are attached to carbon atoms and recur in a linear main chain every two to three carbon atoms, where «each side chain is preferred contains no more than 6 carbon atoms. Where Imino groups are separated from one another by ethylene groups, the linear polyimines are referred to as polyethyleneimines. If the imino groups are separated from one another by propylene groups, we speak of polypropylene imines.

The molecular weights of the imine polymers which can be used are at least 1,000, preferably from 5,000 to 50,000.

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If the. However, condensation continues for too long .or if the conditions are unfavorable, .infusible, water-insoluble resins. If 2,2-dimethylethylehimine is used as the reactant, the Reaction controlled so that the compounds formed are sufficiently water soluble to be in effective concentrations can be used. Long-chain water-soluble cationic polymers by condensing formaldehyde with a polyalkylenepolyamine, such as Tetraethylene pentamine, made to crosslink the polyamines with a variety of methylene bridges.

The above condensates can generally be considered water-soluble Cationic polymers are referred to, which a large number of cationic sites in a straight or branched chain included.

Yet another class of cationic resins includes addition polymers, which form organic cations in an aqueous medium, which have a sufficient number of positive charges, distributed on numerous strips of the polymer. In general, these substances have a molecular weight of over 100,000 and have a hydrophilic side chain Group that has the ability to make the mentioned positive , Charge au, typical representatives of this group are polyvinylpyridine, or other similar monomers with nitrogen containing cores. This class also includes polyvinyl

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pyrrolidine. Salts of the above compounds are also suitable.

The well-known quaternary ammonium compounds of vinylbenzyl are also useful cationic materials. This subheading includes homopolymers of the quaternary ammonium salts of vinylbenzyl or their copolymers, produced by copolymerization with acrylamide, methacrylamide etc .. The quaternary compounds of vinylbenzyl are generally by chloromethylating polystyrene and then substituting the chlorine group with a tertiary amine produced to the corresponding nitrogen quaternary to build.

Other examples of cationic polymers used as treating agents in the first stage of the process according to the invention can be used are homopolymers and water-soluble copolymers of aminoethyl acrylate hydrochloride, Aminoethyl methacrylate hydrochloride or substituted ammonium alkyl acrylates or methacrylates, such as N-methyl- or N-N-dimethylaminoalkyl acrylate or methacrylate, in which the alkyl groups contain 2-3 carbons or suitable substances. Other cationic polymers can be obtained when the cationic monomer of the type described is monoethylene with any one or more unsaturated monomers is copolymerized. Diee'es The latter monomers must be ssur Viny! polymerisation fa-

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hig, so that the copolymer formed is water-soluble or is dispersible in water. Suitable monomers of this type are acrylamide, methacrylamide, acrylonitrile, lower alkyl esters of acrylic and methacrylic acid, vinyl methyl ether etc.

Compounds preferred according to the invention are (1) cationic starches of the type described above and those which are known under the trademark Q-Tac, and (2) a cationic Copolymer of dimethylaminoethyl methacrylate and acrylamide.

The following substances can be used to produce the polymer be used:

Acrylamide - 101.25 g

Dimethylaminoethyl methacrylate - 33 »75 g HCl (CP grade 37-38%) - 21.00g

H ₂ O (distilled) - 144.00 g

Total 300.00 g

The dimethylaminoethyl methacrylate was distilled in 144 g Dissolved water and cooled the solution to 25 ° C. In addition slowly became sufficient hydrogen chloride with good mixing added to lower the pH to 5 »0 while the temperature was kept at 25 ° C during the neutralization. The acrylamide (101.25 g) became the reaction mixture added until it had dissolved. All of the monomer solution was then adjusted to pH 5 »0 again.

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2.7 g of petroleum sulfonate were dissolved in 592 g of tuluene and added to the reaction vessel. The tuluene mixture was on 50 ° G and heated with nitrogen at a flow rate from 1500 ccm / min. flushed.

0.166% tertiary butyl hydroperoxide 70, based on 135 g of monomer, were under. Stir to all of the monomer solution given. This solution was then added to the heated toluene—? mixture was added and the temperature was kept at 50 ° 0 while passing nitrogen through. The reaction mixture was Maintained at 50 ° C for 2 hours after preparation. Afterward the water was removed by azeotropic distillation, the polymer was separated from the toluene and the Air dried. . -,

The polymer obtained in this way had a viscosity of about 3OOO cps, so it is a high molecular weight, water-soluble dimethylaminoethyl methacrylate-acrylamide mis chpölymerisat. Of course, the way of working can be modified to a large extent will. The viscosities of a 1% solution can from 100 cps to 5000 cps. The preferred product has a viscosity of 2000-4000 cps. A 1% solution viscosity from about 3000-4000 cps represents a molecular weight The ratio of amine to acrylamide can easily be varied from 5 to 50% by weight. Of course, other acids can also be used for neutralization, and other acids can be used instead of petroleum sulfonate

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Emulsifiers are used. In addition to toluene, other solvents are also suitable, for example aromatic, aliphatic, chlorinated and the like compounds. Any organic peroxide or inorganic Itedox system is suitable for the process. _v

The amount of the cationic colloid can be from 0.004 -? 3.0%, preferably 0.01-1.5 % _t "based on the dry fiber weight, vary *. ■

The second component used in the present invention can be general defined as an anionic high molecular weight polymer will*

These polymers consist of substances that form organic anions in an aqueous medium that have a measurable negative electrical charge . Particularly preferred anionic substances are polymeric substances which have a sufficient number of negative charges distributed at numerous points on the polymer. They generally have a molecular weight of at least 100,000 and result from the polymerization of at least one aonoolefinic compound via an aliphatic unsaturated group. These polymers must be soluble or dispersible in water and be essentially free of crosslinking, which means that they are soluble or dispersible in water. Usable anionic substances, which correspond to the purposes of the invention, are synthetic dispersible in water.

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see - polymers with a linear hydrocarbon structure, which have a hydrophilic group in a side chain, such as Carboxylic acid, carboxylic acid anhydride, carboxylic acid salt groups and copolymers of the aforementioned type. Typical water-dispersible synthetic anionic organic polymers of this type, which are suitable for the inventive Procedures have proven to be appropriate are:

Surname

Polyacrylate sodium salt

Polymethacrylic sodium

Maleic anhydride vinyl acetate copolymer

Polyvinyl methyl ether maleic anhydride copolymer

Methacrylic acid-acrylamide copolymer

Characteristic group

-CH ₂ -CH-

000 (-)

Na (+) "" ■

-CH ₂ -C-

COO (-> Na .. (+)

-CH-CH ₂ -CH CH-

I I I 0

O = C C = O ^ O

-CH-CH
I.
OCH,

CH

CH CH-

II 0 * 0 CO

CH

I.
COO (-)

CONH

Polyacrylic acid

-CH ₂ -CH-C

COO (-)
HC ₊ )

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No. ₄ . 7th

Urine

Isopropenyl acetate maleic anhydride / tarriua salt

Itaconic acid vinyl acetate

* L -Methylstyrene maleic anhydride sodium salt

Styrene maleic anhydride sodium salt

Methyl methacrylate maleic anhydride sodium salt

Acrylic acid-styrene mix polymer Characteristic group CH,

CH-

—C / U »-» - C ~~~ GH

² I f

CH ₂ GO

C = O

ic *

Na (+) Bfa (+)

OOQ (-) HC +).

-CH — CH ₀ - CH ₀ - CH-I 2 2,

OH ₂ COOC-) O

CH +) CH-.C-0

-CH-

GQOC-) COOC-) ) NaC +)

X-)

COOC-) Na (+)

COOCH

COOC-) CQOC-)) Na (+)

Am useful aaionisohes Miscjipolyaerisat can from one Polycartic acid monomers and at least one other

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polymerizable monomers are produced with it. The 'polycarboxylic acid can be a compound such as maleic anhydride, acrylic acid, maleic acid, fumaric acid, itaconic acid, aconitic acid, citraconic acid and the like ), the alkaline earth metal derivatives (e.g. magnesium, calcium, barium and strontium) and ammonium salts of these acids, the partial alkyl esters (e.g. methyl, ethyl, propyl, butyl, monoesters), the salts of these partial alkyl esters and the substituted amides of these polycarboxylic acids or one A variety of other different monomers are polymerizable. When a hydrophilic polycarboxylic acid such as maleic acid is used as a starting component, a hydrophobic comonomer such as styrene, & -methylstyrene, vinyltQluol, chlorostyrene, vinyl acetate, vinyl chloride, vinyl formate, vinyl alkyl ethers, alkyl acrylates, alkyl methacrylates, ethylene, propylene and / or Isobutylene can be used. The synthetic copolymers mentioned are preferably prepared by reacting equimolar amounts of a polycarboxylic acid and at least one other monomer. However, certain unsaturated polycarboxylic acids can be polymerized in less than equimolar amounts with some of the less hydrophobic comonomers.

Another useful class of anionic polymers is a linear high molecular weight polymer or mixed polymer

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!. sat Vinylary a hydrocarbon, such as styrene, vinyl toluene •, methylstyrene, Viny xylene or the like, which are polymerized and then sulfonated under conditions ^ -controlled form a water-soluble, substantially linear polymeric sulfonate to ^"!.;

Among the anionic compounds within the scope of the invention are used are anionic acrylamide polymers, for example copolymers of sodium acrylate and acrylamide. The most preferred copolymers are polymeric acrylamides and contain 5 - 95% by weight of sodium polyacrylate and 5-95% by weight of polyacrylamide and its molecular weight is over 1 million. Other very preferred polymers and copolymers of acrylic acid are those produced by vinyl polymerisation of acrylic acid, methacrylic acid, SuIfoäthylacrylat, Oarboxyäthylacrylat, or their salts or copolymers of the salts or acids, prepared by appropriate copolymerization with monomers, such as Acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, lower alkyl esters, alkyl esters of acrylic acid, yinyl alkyl ethers and the like can be obtained. A third monomer in quantities up to 20% by weight also results in an effective polymer.

The anionic polymers described above can be prepared by known processes. Many of those mentioned

_B AD

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Polymers are commercially available in sufficient quantities.

The preferred anionic polymers according to the invention are used are terpolymers of three groups of monomers. These are done in a single process step polymerized with each other in such a way that a terpolymer is formed which has recurring units, their respective polar groupings depending on the amount of each monomer used. the exact molecular structure can of course not be determined, but is assumed on the basis of the proportions of the monomers with their corresponding side groups on average. A special polymerization process, which is described in more detail below, results in extremely high molecular weights and obtain the desired physical form of a free flowing white powder.

The first major starting monomeric reactant is acrylamide. This monomer is easy to use known manufacturing processes, such as partial hydrolysis of acrylonitrile. It was found that the Appropriate amount of acrylamide to achieve the desired drainage results, 85-95 parts by weight, preferably 89.5-94.5 parts by weight is.

The next monomeric starting product is a polymerizable polycarboxylic acid such as maleic acid or maleic anhydride

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⁸ A ORIGINAL

or fumaric acid, Again, are the amounts used this monomer is important. Excellent storage capacity is achieved when 0.3-2.0 parts by weight of the compounds mentioned, such as maleic anhydride, are used will. The most preferred storage aids contain from 0.5-1.5 parts by weight of the polycarboxylic acid monomer. Because of its low cost and availability, maleic anhydride is used Of the three compounds mentioned, the two most important, which both hydrolyzes during the polymerization as well as polymerized to form a variety of carboxyl groups.

The last monomeric component is a water soluble one Ethylenically unsaturated monomer with polar groups, for example acrylic acid and its salts and allyl esters, Vinyl pyrrolidone, vinyl acetate, methacrylamide, vinyl alkyl ethers, such as methyl vinyl ether, methacrylic acid and their salts and alkyl esters, acrylonitrile, methacrylonitrile, allyl alcohol, Allylamine and the like. Water-soluble substances are understood as meaning not only those substances which are soluble in water in all proportions, but also those substances Monomers that are only sparingly soluble, but are nonetheless dispersed or emulsified in some way in water can. The amount of ethylenic used as the starting material Unsaturated monomers can be from about 3-5 parts by weight vary. Best results in terms of spoke

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effect and the physical state of a free flowing powder are achieved with 5-9 parts by weight of ethylenically unsaturated monomer.

The terpolymers used according to the invention contain the following polymeric reaction participants and proportions by weight of the raw materials.

Connection A Monomer parts by weight

Acrylamide 85.0-95.0

Polycarboxylic acid monomer 0.3-2.0

athylenically unsaturated

water-soluble monomer 3 »0-15.0

Compound B shows a preferred general terpolymer:

Connection B Monomer parts by weight

Acrylamide 89.5-94.5

Polycarboxylic acid monomer 0.5-1.5

athylenically unsaturated

water soluble monomer 5.0-9.0

The most useful specific terpolymer with proportions according to compound B contains polyacrylamide, maleic anhydride and methacrylic acid.

About terpolymers with exceptionally high molecular weights and correspondingly excellent storage effect

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to achieve, “became a special polymerisation process • applied. This.- procedure included manufacturing the highly concentrated monomer solution, adding an inert , Thermal conductivity solvent, which can be called organic solvent, and subsequent polymerization at relatively low temperatures. The polymerization must be carried out with vigorous stirring and in the presence of an anti-stick agent be carried out in order to prevent the polymer formed from agglomerating into an unusable mass. If the conditions are followed exactly, relatively small granules are created that can easily become one free flowing white soluble powder can be ground and are immediately ready for use without further treatment. The monomers actually terpolymerize in a separate one Layer within the system in the presence of a surface active Agent that acts as an anti-stick agent.

In detail, the procedure is as follows: there is a Aqueous solution prepared containing about $ 0-80% by weight of monomers, 20-70% water and about 0.0Oj-0.2%, based on contains the weight of the monomer present, a polymerization catalyst such as potassium persulfate. The water solution is then added to or mixed with a water-insoluble organic heat transfer agent, preferably is able to form an azeotropic mixture with water. The mixture should contain a small amount of a surfactant

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Contains agent that prevents the terpolymer sticks to the stirrer or the walls of the reaction vessel. The temperature of the system will be up to a desired one The point is raised and the mixture is kept in motion by a stirrer. Oxygen gets out of the system either by purging with an inert gas such as nitrogen or carbon dioxide, removed by applying a vacuum or by boiling the mixture. Once the oxygen has escaped the polymerization begins. If an emulsion is formed due to the surfactant, it will break and the polymerization proceeds in a separate layer. The organic heat transfer agent surrounds the aqueous one Medium when the polymerization occurs. In order to continuously convert the formed polymer layer into small particles share, is violently stirred. These particles can have a diameter of, for example, about 0.063-50.8 mm, more often from about 6.35 ~ 12.7mm. With a preferred Embodiment is the temperature of the mixture up to its boiling point is increased or kept at that boiling point when the polymerization is at the boiling point of the mixture is carried out. After the polymerization has ended, the water is removed by azeotropic distillation. The boiling temperature varies, of course, according to the heat transfer agent in the mixture.

During the cooking process, the organic solvent becomes preferred condensed and returned to the mixture that

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© AD ORIGINAL

Water is collected and removed. After 60-100 % of the water has been removed, the granules formed are separated from the solvent by filtration, washed and air-dried.

It was found that benzene, toluene, xylene and ethylene dichloride are particularly suitable, as are carbon tetrachloride, Tetrachlorethylene and the like. Other similar organic compounds that form azeotropic mixtures with water form, but can also be used without difficulty if they do not have any alcohol, aldehyde or ketone groups that could cause undesirable side reactions. The polymerization medium can also be non-azeotropic Contain component with a boiling point above the distillation temperature. The above substances can are referred to as organic solvents and are all water-insoluble organic heat exchangers that regarded as inert for the process according to the invention will. These organic substances serve as heat conductors or heat spreader through suspension of the aqueous monomer phase and the subsequently formed terpolymer.

Conventional peroxidic oxidizing agents such as potassium persulfate, hydrogen peroxide and ammonium persulfate can be used as catalysts. Water soluble compounds are preferred. The amount of the catalyst added may be from about 0.003 to 0 _t 2 wt .- $, preferably from about 0.003 to 0.5

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% By weight, based on the weight of the monomers. Catalyst concentrations above 0.2% polymerize the aqueous solution, which contains the three monomers, but the products formed thereby are inferior to those formed with the abovementioned amounts of catalyst. One of the advantages of the process is that the polymerization takes place with very small amounts of catalyst can be carried out.

As mentioned above, a surfactant must be added to the polymerization mixture in order to to prevent the polymer from sticking to the walls of the reaction vessel and to the stirrer. There are numerous Preparations on the market that do this job. to Ethylene oxide condensates of fatty acid amides are known under the marks "Ethomid" S-15, 0-15 and HT-15, as well as sorbitan monooleate, trademarks "Arlecel 80" and "Span 80 ". Sorbitan monostearate, sodium dodecylbenzenesulfonate, Aluminum stearates and aluminum oleates suitable adhesive agents. At the beginning of the reaction, the The presence of the surfactant causes the formation of a Effect emulsion. However, it is important to have the emulsion breaks and forms two separate and distinct layers prior to polymerization. The amount of surfactant Additive can vary from about 0.5 - 7% by weight, based on the weight of the heat-conducting agent, and is preferably

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wise about 2-4% by weight. During the polymerization it is • the aqueous medium containing the monomers essentially surrounded by the organic heat transfer agent.

According to a preferred embodiment, the polymerization is carried out using a redox catalyst system. In the process described, oxygen must be either avoided or removed by any means to allow the catalyst to form free residues. In one In the redox system, the catalyst is activated by a reducing agent that releases immediately in the absence of oxygen Forms radicals without the need to apply heat. One of the most commonly used reducing agents is sodium metabisulfite. Other corresponding agents are water-soluble thiosulphates, bisulphites, hydrosulphites and reducing salts, like the sulfates of metals, which occur in several valencies, for example cobalt, iron, nickel and copper. The use of a redox system has several advantages, the most important of which is the ability to carry out the polymerization at lower temperatures. It is not required to decompose the catalyst.

As has been found, numerous surfactants can be used. The compounds mentioned are only examples of suitable and easily available Links. The amount added can be from about 0.5-7% by weight, preferably 2-4% by weight, based on the

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Weight of the heat transfer agent. However, excessive amounts must be avoided, as an excess tends to to form stable emulsions or suspensions. First and foremost, they prevent the terpolymer formed from adhering to the stirrer or the walls of the reaction vessel stuck.

The selection of the particular catalysts - or activators if a redox system is used - is not the job of the Invention. Known catalysts such as potassium persulfate and known activators such as sodium metabisulfite work satisfactorily. But it is important * that the amount of the added Catalyst from 0.00.3 - about 0.2%, based on the Weight of monomers varies.

The catalyst and the activator "are preferably used before the addition to the aqueous solutions of the three monomers dissolved in separate water solutions. The catalyst and activator can be added in the aqueous monomer solution immediately before the addition to the organic heat transfer agent. On the other hand, the catalyst can be used in a small amount Dissolved amount of water and then to the organic heat transfer agent be added prior to addition to the monomer solution. Another satisfactory method is to that the catalyst and / or activator is dissolved in water and this solution is added to the reaction mixture, after the monomer solution was added to the thermal interface.

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The water content of the terpolymers produced in this way should be around O-28 % . A .., amount of water is preferably caking of about 5 -15% When the moisture content is greater than about 28%, tend to · the granules.

Several organic, relatively water-insoluble thermal conductors were suggested above. It is useful that these liquids form azeotropic mixtures with water. Aaeotropic mixtures are to be understood as meaning which raise the boiling point of water under a given pressure, i.e. the water distills above the normal boiling points «above. l! in azeotropic mixture allows it to remove water from the terpolymer without that special drying devices are used. the The selection of the heat transfer agent is not particularly critical; it is only necessary to ensure that these liquids do not contain reactive groups such as alcohol or aldehydes or ketone groups. Benzene is proportionate cheap compound and has been found to give excellent results. Hence will it is preferred as a thermal conductor.

As already stated, the heat transfer agent plays one important role in concentrated solution polymerization. The special task of the organic liquid is there in deriving the heat of reaction from the polymer being formed.

_ _. BATH

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16218-99

One of the most important steps in polymerization is the removal of dissolved oxygen from the reaction mixture. This can be done by (1) flushing the reaction mixture with an inert gas such as nitrogen or carbon dioxide, (2) Boiling the heat mixture or (3) applying a partial vacuum to the system. If an inert gas is used, it is best done by bubbling the gas through it by means of a distributor or atomizer placed below the surface of the reaction mixture *

One of the main disadvantages of the known processes is that only dilute solutions of the monomers can be polymerized without a violent reaction occurring or without a rubber-like, non-flowable mass being formed. In the process described, the total monomer content of the aqueous solution can vary from about 30-80% by weight. The fact that terpolymers with unusual and extremely advantageous properties can be formed is primarily due to the fact that concentrated monomer solutions can be used. _r

The typical terpolymers and the process for their Production will be explained in more detail using the following examples explained.

1 O 9 8 2 6/12? S.

example 1

“There were maleic anhydride, methacrylic acid and acrylamide using an Eedox system and high monomer concentration terpolymerized. Unless otherwise stated, the amounts are given as percentages by weight.

There were 1.125 g maleic anhydride (0.13 #), 9.4 g methacrylic acid (1.11%> and 10.0 g of a 50% concentrated aqueous solution of sodium hydroxide (1.1 %) to 108.0 g of water (12.6 %) were added * The mixture was mixed until complete solution came in. 124.425 g of acrylamide (14-, 59 %) were added to this mixture, stirred gently and gently warmed to a temperature of not more than 38 ° 0 It is important that the temperature does not rise higher, otherwise premature polymerisation would occur. The pH of the solution was then adjusted to 9.0 with 50% caustic solution *

In a separate 1000 ml three-necked flask equipped with a thermometer, a Dean and Stark collecting device, a cooler, a stirring device and a variable Tranef or? With a heating mantle attached to it, 754.0 grams of toluene (67.32 "Jf) and 19.6 grams of sorbitan monooleate (trademark Arlecel 80) detackifying agent (2.30 %) were added. The flask was then filled with nitrogen at a flow rate. it was rinsed at 960 ccm / ml * After sufficient rinsing of the mixture of inert solvent and antiadhesive agent, the basic solution of the monomer was placed in the 1000 ecm flask

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- Submitted. A vacuum (203.2 mm) was applied and the mixture was heated to 70.degree. After this temperature had been reached, the vacuum was interrupted and 4.8 g of a 1% strength aqueous solution of Na — SpO ₁ - (0.56 %) were added with stirring. After a few seconds, 1.2 g of a 1% strength aqueous solution of K2S2Ög (0.14%) were added. During the addition of this redox agent, the temperature fell by 2-3 degrees C. The redox catalyst was completely added and the vacuum was re-established (203.2 mm) and heated to 70.degree. When this temperature was reached, the vacuum was interrupted again and only nitrogen was introduced during the reaction period. Heating was carried out to maintain the temperature of the reaction mixture at 70 ° C until the reaction became exothermic. At this point the heating was stopped and the temperature dropped to 68 ° C. After the exothermic reaction had ended, the temperature of the mixture was held at 70 ° C. for about 50-60 minutes. At that time the water was then removed as an azeotropic distillate. About 90 % of the total water was distilled off. After filtering, a white granulated product remained.

Example 2

The procedure was carried out in a similar manner to Example 1. 85.5 g of acrylamide, 4.0 g of methacrylic acid, 0.5 g of maleic anhydride and 72 ml of distilled water are added. The monomer solution was

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~ 37 -

stirred and the pH value adjusted from 3.2 to 6-3 with 50% concentrated sodium hydroxide. With gentle stirring, 0.8 ml of a 1% aqueous solution of ^ SgO ^ and 3.2 ml of a 1% aqueous NapSpO, - were added to the above monomer solution. In a separate 1000 ml reaction flask, the inert organic solution containing the heat transfer agent and the antiadhesive agent was prepared. This solvent solution contained 574 g of toluene and 19.6 g of sorbitan monooleate (trademark Irlacel 80). After the inert solvent solution had been heated to 71 ° C. with stirring, the aqueous monomer solution was slowly added. During this addition, the temperature fell to 55 ° C., whereupon the mixture was heated again to 75 °. At this time, nitrogen was blown over the reaction surface at a vacuum of 203.2 mm and the temperature was held at 75 ° 0 for 26 minutes. After this time phase separation was observed. During this time, the "vacuum was continuously maintained, and nitrogen was passed over the surface. After the temperature had dropped to about 74 · ° 0, the polymerization was considered complete and the water removed by azeotropic distillation. In this case were withdrawn 72 ml of water. The The white flowing granules obtained were washed and separated by vacuum filtration.The granules could easily be ground to a sieve fineness of 40.

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The amount of anionic polymer needed to carry out must be added in the process depends on the amount of cationic colloid. A preferred area for this additive can be made by a weight ratio of colloid to be expressed as additive from about 25 ϊ 1 to about 1: 2. The preferred weight ratio is from 15 J 1 to 1: 1.

As stated above, the method according to the invention comprises the successive addition to an aqueous suspension of paper pulp fibers consisting of a cationic component from an aluminum ion source and a cationic polymer, cationic starch or cationic Gum followed by an anionic polymer. The treated Ptilpesuspension can then in any known Paper making machine to be processed into paper, in which the aqueous fraction of the suspension of the fibers runs off, so that a fibrous web remains, which then is dried into paper. The aluminum ion source and the cationic compound can be added simultaneously or at different times. It will, however preferred that the aluminum ion source first and then the cationic compound is added. In any case, the anionic polymer becomes after the addition of the aluminum ion source and added to the cationic compound.

109 826 / $ 122 ...-., - ^B & D _ÖRiQ

The alum is, as stated above, preferably to the Pulp suspension added in the Hollander, according to the usual Practice in paper mills. The encore can also be given to anyone , another suitable location, such as directly in front of the fan pump, take place. The cationic compound can also be used at any point in the papermaking process before the Point at which the suspension hits the Fourdrinier wire or another porous device is spread, may be added. When these two substances that have the cationic component have had enough time to distribute themselves well in the pulp suspension, the anionic polymer can be added. In a preferred embodiment, "the anionic Polymer to the pulp suspension immediately in front of the head container given. Sufficient time is allowed for the anionic component to be evenly distributed thereby to derive the maximum benefit from the treatment without compromising the properties of the pulp suspension before it Significantly affect formation into a fibrous web.

The following examples illustrate various embodiments of the invention.

Example 3

The inventive method was carried out in a large paper mill carried out in the northwestern United States. The paper made here was a cardboard insert with a

ρ Basic weight of about 24 494 kg per 6.45 m. Before the addition

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BATH

The paper machine was set to full speed for any chemicals.

The control factor for the production speed was the time it took to convert the aqueous fraction of to drain the fibers and the shape known as wet web. An appearance was observed which is called the wet line is known. This is a term used in papermaking and refers to the point on the Fourdrinier wire which the aqueous suspension of pulp fibers is actually formed into a tough, coherent web of fibers. When the paper machine was in equilibrium, numerous chemicals were added to the aqueous suspension in order to determine their effect on this stabilized wet line. No effect was seen with an addition in the Hollander of about 2% alum based on the fibers observed. Then 6.80 kg of a cationic Starch added per ton of dry fiber. A starch ether was used here, which was combined with a reaction product of epichlorohydrin and trimethylamine in the presence of a strong alkaline catalyst was etherified. At this point, only a minor change in the wet line was noticed, with the wet line shifted almost imperceptibly towards the head container and indicated a slight improvement in drainage.

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Subsequent to this process step, an anionic polymer made from a mixture of monomers, consisting of about 85% acrylamide and 15 % acrylic acid and a molecular weight of over 100,000, was added immediately in front of the top container. Almost immediately after this addition, an extremely strong effect was achieved observed on the wet line with a substantial improvement in drainage rate. In particular, it was found that the mass line migrated with an appreciable speed in the head container _v Once the equilibrium of the system was restored, has been determined by the operator, that in the dewatering an approximately 25% improvement occurred, as indicated by the shift of the wet line became obvious »

In order to determine the savings achieved in this particular paper mill by the method according to the invention, the production rate would be increased until the wet line had returned to its starting point. As soon as the system was in equilibrium again, this same paper machine was able to produce over 20% more paper per hour, whereby the economy of the process according to the invention becomes clear.

Example _; 4 \

A number of trials with unbleached softwood kraft pulp were made performed to explore the various effects of the

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to determine the method according to the invention on the drainage. The device used here consisted of a cylinder which was provided with a sieve and at the bottom of which a vacuum device was arranged. The drainage or drainage was determined by adding a known amount of an aqueous suspension of pulp fibers to the device, measuring the time required for the aqueous portion of the suspension to drain off the fibers under constant vacuum suction. Prior to attenuation, the particular pulp used in these experiments had a drainage rate of 6 seconds. The paper made from this unbeaten material was completely unusable for commercial purposes. The pulp was then ground to a consistency sufficient to achieve drainage in 100 seconds. Although this milled pulp had superior dry strength and the quality of the paper made from it was relatively acceptable, the dewatering rate was too slow for efficient paper production. Ideally, an optimal situation would arise where a pulp had the drainage properties of an unground pulp and possessed the strength and other qualities of the highly milled material. In order to achieve this, pulps were produced according to the method according to the invention. . .-iq

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'' SAD ORIGINAL

Several drainage attempts were made in order to show the surprising effect of the features of the method according to the invention. Process A represents the unground material, without additives. Process B illustrates the ground material without additives. Process C shows the ground material with an addition of 1.5 % of a cationic starch. Procedure D uses 2 % alum plus 1.5 % cationic starch, Procedure E is an experiment with 0.2% of a cationic polymer, in which case a polyamine made by the condensation of epihlorohydrin and an alkylene polyamine was used. Process F illustrates the use of 2 % alum plus 0.2 % of the same cationic polyamine as an additive as Process E. Process G contains 2 % alum and 0.1% of an acrylamidaeryl acid copolymer with a molecular weight of about 4 million. Process H uses 1.5 % cationic starch and 0.1 % of the above-mentioned anionic polymer. Procedure I uses the cationic polyamine in an amount of 0.2% plus 0.1 % of the above anionic polymer. Process J, which represents the process according to the invention, worked with a pulp which contained 0.5 % alum plus 0.5 % of the cationic starch and _0.1 % of the above-mentioned anionic polymer. Vorpang K also relates to the process according to the invention, 1% alum plus 1 % cationic starch plus 0.2% of the anionic polymer being used. Eventually, process 1 is closed .

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■ consider, which also relates to the process according to the invention and in which 0.5% alum, 0.15 % of the cationic polyamines and O ₁ Ί% of the anionic polymer were used. All the percentages are based on the dry dust weight of the fibers. In each case the additive mentioned first was also added first * The results obtained in these tests are summarized in the following table *

Table X Effect of the additives on. die JÖrMnierii!; eschwiiidiiBiteeit Process ^ No » Braini generates seconds 1 6th B. 100 C. 99 D. 96 E. 97 P. 76 G ^ 4 H 84 I. 91 J 18th E. 8th I « 14th

From this it can be seen that only the procedures <?, K and 1> show a sufficient mustard cuag of the draining speed! In the experiment, the heavily milled pulp used in process K was modified by the method according to the invention to such an extent that iieft -ä & m laiilmagsiffad (Brmini # s? Eif @ ös6haf * - ttn) approached the non-refined pulp. The ITorgäiige 0 _t S _t I, f, fi _t tt, tmd I concern available _t b # i din only two of the three "necessary miitives were used *

Compared with the method according to the invention, none shows of these attempts a sufficient reduction of the drainage speed

Similar experiments carried out on other pulps used other cationic polymers, cationic starches and cationic rubbers together with alum, aluminum chloride, and sodium aluminate as well as a large number of anionic polymers with molecular weights of 50,000 - 100,000 up to 5 million. In each case there were similar essentials Improvements in drainage observed. There were Attempts have also been made to determine the quality of the papers produced under these process conditions. In many Cases was the strength, the 'folding resistance and numerous other properties of the properties of the types of paper produced from strongly ground, unmodified pulps far superior.

As already stated above, the combination of substances (1) used according to the invention contains alum-Q-tacanionic Polymer (acrylamide plus polycarnoxylic acid monomers plus ethylenically unsaturated water-soluble monomer) or (2) alum-cationic polymer from dimethylaminoethyl methacrylate and acrylamide-anionic terpolymer. Each of these combinations results in a better drainage rate, while maintaining the strength of the paper and its other properties »

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Claims (1)

- 46 claims re; r r ^ :; ? ·; - SSä = S3: S: 33SS3SSSS = = S = 3 = === = = = SX 1, a process for the production of paper from an aqueous suspension of paper pulp fibers, characterized in that a cationic additive consisting of about 0.2-5.0 % of an aluminum ion source, calculated as Alum and based on the dry fiber weight, and from about 0.1-3.0% of a cationic substance, such as a cationic polymer, cationic starch or cationic gum, the amount being based on the dry weight of the fibers in the suspension, and (b ) an anionic polymer with a molecular weight of at least 100,000 in a sufficient amount to form a weight ratio of this additive to the anionic polymer of about 25 t 1 to about 1: 2, and then the treated pulp suspension on a porous device is brought to drain the aqueous portion of the suspension and is here formed into a fiber web. 2 · The method according to claim 1, characterized in that the aluminum ion source before adding the cabionic Substance is added. 3 · Method according to claims 1 and 2, characterized in that about 0.5-1.5 % of the aluminum ion source is added, · · ■ rj-.A- *. · ■ - 109826/1225 4-. Method according to claim i "to 3», characterized in that • that the cationic additive in a cruet of about 0 ^: 2 - 1 »5% is added * 5. Process according to claims 1 to 4-, characterized in that the weight ratio is approximately Vp : 1 to approximately 1: 1 6. The method according to claims A to 5, characterized in that an anionic polyacrylamide with a molecular weight of at least 250,000 is used as the anionic polymer. 7. The method according to claim 1, characterized in that «that as a cationic additive, a cationic starch or a cationic copolymer of dimethylaminoethyl methacrylate and acrylamide is used * 8. The method according to claim 1, characterized in that as a cationic additive a cationic starch or a cationic copolymer of dimethyl alcohol ethyl methacrylate and acrylamide and, as an anionic polymer, a terpolymer, produced by micropolymerization of following monomers - "" Sott «» · * '' - .. ■ - '■■■■■■ Qweight part « about β | »α - 95, ■ 0.3 - 2.0 • tndtr ·· athyleniech _____ tiftt · waeeerlbalichee monomer - -------- - '■. ■■■■ -, *: f, 0 is used 109826/1225