DE69931343T2 - MIXTURE OF SILKY ACID AND ACIDOIL TO A MICROPARTICLE SYSTEM FOR PAPER MANUFACTURE - Google Patents

Abstract

A microparticle system for use as a retention and drainage aid in the production of alkaline and acid paper products comprises a high molecular weight flocculant polymer (6) and a silica-acid colloid blend (7), and optionally a cationic coagulant or a medium molecular weight flocculant (5). The high molecular weight flocculant polymer (6) may be added to the furnish after the fan pump (1) and prior to the pressure screen (2); the silica-acid colloid blend (7) may be added to the furnish after the pressure screen (2), and optionally, the coagulant or medium molecular weight flocculant (5) may be added prior to the fan pump (1). Addition of the microparticle system to the paper furnish improves retention and drainage during the papermaking process and sheet formation. The acid colloid of the silica-acid colloid blend (7) is a polymer or a copolymer of a melamine aldehyde acid colloid.

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The The present invention relates to an improved microparticle system, which as an aid in the production of a paper product, for example a paper or a cardboard, with improved properties in the retention and drainage as well as the bow forming areas is used. In particular, it concerns a microparticle system with a silica-acid colloid mixture as inorganic disperse material in a microparticle system.

2. Description of the state of the technique

at the production of paper or paperboard becomes a dilute aqueous composition, which is known as "entry mass" or "pulp" on spraying a moving mesh screen known as a "machine screen". The solid components of this composition, for example cellulose fibers and inorganic particulate filler, are dewatered through the machine screen or separated to one To make paper sheets. The percentage of the on the machine screen retained solid material is referred to as "first pass retention" (FPR) of the papermaking process known. In the papermaking process, retention, drainage and sheet forming aids (D / R / F).

Of the Level of retention is considered to be a function of various mechanisms, For example, the separation by mechanical entrainment, electrostatic Attraction and bridging between the fibers and the fillers in the entry mass. Since both the cellulose fibers and many conventional fillers negative charged, they are repulsive of each other. In essence, the only factor contributing to reinforcement the degree of retention tends, the mechanical entrainment. That is why in general a retention aid is used to determine the degree of retention of the fibers and the fillers to improve on the machine screen. The retention of fines and fillers is for the paper maker important to the retention of the colloid-sized Ensure particles in the bow. This ability of the retention program is measured with first pass retention (FPR). In the past For example, colloidal silica as a microparticle became a retention aid used in alkaline fine paper. If silica is right is applied, it can reduce the retention of fines and fillers reinforce microflakes, which colloidal material hold fast and allow the pulp suspension to drain quickly.

drainage indicates the speed with which water during the Forming the paper sheet is removed from the entry mass. drainage usually designates the removal of water, which takes place before the sheet of paper is pressed out following the formation of the bow takes place. Consequently, be Entwässserungshilfen used to reduce the overall efficiency of dewatering in the production of Paper or cardboard to improve.

forming denotes the formation of the in the papermaking process produced paper or cardboard sheets. The shaping becomes general by the variance of light transmission in a paper sheet rated. High variance indicates "bad" shaping and low variance generally indicates a "good" shaping. If As the degree of retention increases, the degree of molding generally decreases from good shaping to bad shaping.

• a) einzelne Polymere;
• b) doppelte Polymere; oder
• c) Mikropartikelsysteme, welche mit einem Ausflockungsmittel und/oder Koagulierungsmittel verwendet werden können.

It will be appreciated that improvements in retention and drainage and in the forming characteristics for the paper or board sheet are particularly desirable for a number of reasons, the most important of which is productivity. With good retention and drainage, a paper machine can run faster and machine downtime is reduced. By properly shaping the sheets, the amount of paper waste is reduced. These improvements come about through the use of retention and drainage aids. Retention and drainage aids are generally additives used to flocculate the fine, solid material present in the furnish to improve these parameters in the papermaking process. The use of such additives is limited by the effect of flocculation on the formation of the paper sheet. In general, when more retention aid is added, and thus the size of the clumps of fine, solid material increases, there will be variations in the density of the paper sheet, which in the manner set forth above, may result in something occurring, which may be termed " bad "bow forming be records. Excessive flocculation may also affect dewatering, as this may eventually lead to holes in the sheet and a consequent loss of vacuum pressure in the later stages of dewatering during the papermaking process. Retention and drainage aids are generally incorporated into the furnish in the wet end of the paper machine and generally have three types, namely:

• a) individual polymers;
• b) double polymers; or
• c) Microparticle systems which can be used with a flocculant and / or coagulant.

One Microparticle system can generally provide the best result as a retention and drainage aid and is comprehensively described in the prior art. examples for Publications microparticle systems are: EP-B-235,893, in which as inorganic Material bentonite in conjunction with a cationic polymer high Molecular weight used in a specified input sequence becomes; WO-A-94/26972, in which a vinylamide polymer for use in conjunction with one of various inorganic materials such as silica, bentonite, china clay and organic materials is disclosed; WO-A-97/16598, in which kaolin is for use in Compound disclosed with one of various cationic polymers is; and EPO 805234, in which bentonite, silica or acrylate polymer in Compound with a cationic polymer is used.

In US Pat. Nos. 4,305,781 and 4,753,710 is the use nonionic and ionic polymers of high molecular weight in Compound with bentonite as an aid in drainage and retention in papermaking. In the USA patents No. 4,388,150 and No. 4,385,961 is the use of cationic Strength and a colloidal silica. In the USA patents No. 4,643,801 and No. 4,750,974, the use is cationic Strength, of an anionic polymer and colloidal silica high Molecular weight described in papermaking. By doing United States Patent No. 5,185,062 an anionic polymer described as having microparticles with a cationic flocculant of high molecular weight. U.S. Patent No. 5,167,766 discloses the use of charged organic polymers microspheres taught as microparticles in papermaking.

The Use of Acid Colloids of Melamine Formaldehyde (MF) for Wet Strength of paper is well known. It is referred to the TAPPI monograph no. 29 "Wet Strength in Paper and Paperboard "by C. S. Maxwell, J. P. Weidner ed. In US Pat. 2,345,543 is the preparation of stable acidic colloids of melamine formaldehyde and U.S. Patent No. 2,485,080 is the recording of urea in the condensation products. In the USA patents No. 2,559,220 and No. 2,986,489 is the use of these colloids to increase the wet strength of paper taught. In U.S. Patent No. 4,845,148 is the use of an acidic colloid of aminoaldehyde with acrylamide to increase the dry strength of paper described. In the United States patent No. 5,286,347 is the use of a colloid of melamine-formaldehyde to control harmful Resin described in papermaking. In US Pat. 4,461,858 is the use of colloid blends of polyvinyl alcohol and melamine formaldehyde for the wet strength of paper is described. In US Pat. 4,009,706 is the use of MF colloid and anionic polymer high molecular weight taught to flocculate raw sugar. In U.S. Patent No. 5,382,378 is a colloidal composition Silica and melamine aldehyde, urea aldehyde or acid Colloid of melamine urea aldehyde described for the purpose collecting paints, oils and fats or colors from process water mixed together are.

One Microparticle system can generally be a flocculating polymer with or without a cationic coagulant and a fine, comprising particulate material. The fine, disperse material can be an inorganic be disperse material and improves the efficiency of the flocculant and / or enabled the production of smaller, more uniform flakes.

In spite of of the several microparticle systems currently in use for the paper mills stand in order to achieve a better running behavior of the paper machine and / or a special end use characteristic of the paper such as an improved shaping of the sheet for better printability or an improved surface strength To achieve, the very important and essential need for an improved remains Microparticle system to improve the paper or cardboard by improving drainage and retention during the papermaking process and the molding properties in consist of the trained bow.

SUMMARY OF THE INVENTION

With The present invention addresses this need described above covered. The present invention relates to a microparticle system, as a retention and drainage aid used in a papermaking process.

According to one First embodiment of the present invention is a method for the production of paper, which involves the introduction of a Microparticle system, for example, a retention and / or Drainage aid, in a pulp or a collection mass, which includes a flocculating high molecular weight polymer and an inorganic disperse material, wherein the inorganic disperse material a silica-acid colloid mixture and wherein said mixture is colloidal silica and includes an acidic colloid.

According to one Second aspect of the present invention will be an improved Microparticle created, which as retention and / or drainage aid is introduced into a pulp or an entry mass, and wherein the microparticle system is a high molecular weight flocculating polymer and an inorganic particulate material, wherein the inorganic disperse material comprises a silica-acid colloid mixture, and wherein said mixture is colloidal silica and an acid Colloid includes.

According to one third embodiment of the present invention, a paper or paperboard product with improved properties in the field of Retention, drainage and forming, wherein the paper or paperboard product by Introducing an improved microparticle system into an aqueous, cellulose-containing pulp or an entry mass produced wherein the microparticle system is a flocculating polymer high Comprising molecular weight and an inorganic particulate material, which is a silica-acid colloid mixture and wherein said mixture is colloidal silica and includes an acidic colloid.

• a) nach einer ersten Scherstufe das Einbringen eines ausflockenden Polymers hohen Molekulargewichts in den dünnen Massestrom einer Papiereintragsmasse,
• b) nach einer zweiten Scherstufe das Einbringen eines anorganischen, dispersen Materials aus einer Siliciumdioxid-Säure-Kolloidmischung mit kolloidalem Siliciumdioxid und einem sauren Kolloid in die Papiereintragsmasse;
• c) das Entwässern der Papiereintragsmasse zur Formung eines Papierbogens, und
• d) das Trocknen des Bogens.

According to a fourth aspect of the invention, a method is provided in which paper or paperboard is produced by forming an aqueous, cellulosic furnish with the following steps:

• a) after a first shear stage, introducing a high molecular weight flocculating polymer into the thin mass flow of a papermaking furnish;
• b) after a second shear stage, introducing into the papermaking furnish an inorganic disperse silica-colloid-colloidal mixture comprising colloidal silica and an acidic colloid;
• c) dewatering the papermaking furnish to form a paper sheet, and
• d) drying the sheet.

wobei R₁ aus der Gruppe ausgewählt ist, die aus einem geradem und einem verzweigtem C_1-4-Alkyl besteht. Vorzugsweise ist das saure Kolloid ein Polymer von Melaminformaldehyd, kann jedoch ein Copolymer von Melaminformaldehyd und Harnstoff-Formaldehyd oder ein Copolymer mit Melaminaldehyd und Kondensaten oder ein Copolymer von einer Amin-Aldehyd-Art und ethylenisch ungesättigten Monomeren sein.The acidic colloid may comprise an aqueous solution of a water-soluble polymer, which may be melamine aldehyde, urea aldehyde or melamine-urea aldehyde, and which is aldehyde

wherein R ₁ is selected from the group consisting of straight and branched C _1-4 alkyl. Preferably, the acidic colloid is a polymer of melamine-formaldehyde but may be a copolymer of melamine-formaldehyde and urea-formaldehyde or a copolymer with melamine-aldehyde and condensates or a copolymer of an amine-aldehyde type and ethylenically unsaturated monomers.

In the silica-acid colloid mixture For example, the acidic colloid and the colloidal silica are in the ratio range each from about 99.5: 0.5 to about 0.5 to 99.5, based on the total solids, in an acid environment with a pH mixed by 3.0 or below. The silica-acid colloid mixture is present in an amount of from about 0.0005% to 0.5% by weight, based on the dry weight of the solids in the furnish.

The high molecular weight flocculant polymer is present in an amount of from about 0.0025 wt% to about 1.0 wt%, based on the dry weight of solids in the furnish, and the silica-acid colloid blend is in an amount in the range of from 0.0005 wt.% to 0.5 wt.%, based on the dry weight of the solids in the furnish. In the entry mass can ago a high shear rate cationic coagulant or medium molecular weight flocculant may be introduced into a first shear stage and in some cases may be added before or after incorporation of the silica-acid colloid blend. In some cases, it may be more advantageous to change the order of the input sites of the chemical additives in the paper machine. That is, the silica-acid colloid mixture prior to the first shear stage and the coagulant or medium molecular weight flocculant after or before the second shear stage and the high molecular weight flocculant may be introduced into the pulp or furnish after or before the second shear stage.

SHORT DESCRIPTION THE FIGURES

The only figure is a sketch in which a part of a typical Paper machine and the entry points for the components of the microparticle system according to the present Invention are shown in a preferred form.

DETAILED DESCRIPTION OF THE INVENTION

The The invention relates to a microparticle system which serves as a retention and / or drainage aid for special use at the wet end of a paper machine in the papermaking process for both acidic and alkaline Fine paper is used.

In the term "paper" as used herein includes products which comprise a cellulose-containing sheet material, to which a paper sheet, cardboard and the like belong.

With the "microparticle system" according to the invention is the combination of at least one hydrophilic polymer which from flocculant, and an inorganic, disperse material which represents the microparticle in the system, and optionally a cationic coagulant or a Called flocculant medium molecular weight. In the Invention, the inorganic particulate material is a silica-acid colloid mixture. The components of this combination may be the pulp or the Entry mass to be treated, added together, however, are in the manner and order described below preferably added separately.

The The invention may be practiced using a conventional paper machine. According to conventional Practice is the entry mass or the "thin Papierbrei ", which drained to form the paper sheets is, often by thinning made of a thick pulp, which is typically in a mixing container or bucket by mixing pigment or filler, the appropriate Fiber, a desired one Solidifying agents and / or other additives and water manufactured, which can be recycled water. The thin pulp can in conventional Way, for example, using an eddy current cleaner, cleaned become. Usually becomes the thin one Paper pulp by passing through cleaned a centrifugal screen. The thin pulp is usually with one or more radial centrifugal pumps acting as vane pumps are known, pumped along the paper machine. For example can the thin one Paper pulp with a first vane pump be pumped to the centrifugal screen. The thin pulp can with water dilute be to the thin one Paper pulp at the point of entry into this first vane pump or before this first vane pump, i.e. by passing the thick pulp and the dilution water through a mixing pump, train. Then the thin one Pulp by passing through a second centrifugal sieve or printing screen further cleaned and before the Bogenformungsvorgang be passed through a casserole on the paper machine.

The sheet-forming operation can be carried out by using any conventional paper or board molding machine, for example, a flat screen long paper machine, a two-wire former or a paperboard former, or a combination of these forming machines. A method in a paper machine may include the parts shown in the single figure. These parts include a wing pump 1 , a printing screen 2 and a casserole 3 , The thick pulp can be diluted with water to prevent the pulp from entering the vane pump 1 by passing the thick pulp and dilution water through a mixing pump (not shown) to form a thin pulp. The thin pulp is made by passing it through the printing screen 2 cleaned of impurities, and the thin pulp, which from the printing screen 2 Exits, before forming the bow to the casserole 3 guided.

In the single figure are also the preferred entry points for the components of the microparty kelsystems shown according to the present invention. If a cationic coagulant or medium molecular weight flocculant (MMW) is used, it is fed into the thin pulp before the thin pulp through the vane pump 1 is guided, this run by the arrow 4 is designated and the introduction with the arrow 5 is designated. The high molecular weight flocculating polymer (HMW) is added to the thin pulp in the direction indicated by the arrow 6 added manner when this from the vane pump 1 exit, and the silica-acid colloid mixture is added to the thin pulp in the direction indicated by the arrow 7 Significantly added when the thin pulp from the printing screen 2 exit. In the vane pump and the pressure screen 2 high shear steps are generated in the paper machine.

In the invention, the flocculating HMW polymer of the microparticle system is preferably added before the thin pulp reaches the last point of high shear, and the resulting pulp is preferably at the last high shear point, for example, and preferably before adding the silica acid -Colloidmischung the microparticle system according to the invention sheared. The sole figure shows that the HMW flocculant is added before the thin pulp passes through the pressure screen 2 and shows that the silica-acid colloid mixture is added after the pulp has passed through the pressure screen 2 has gone.

Preferably is the flocculating HMW polymer of the microparticle system according to the invention in the thin one Pulp (i.e., having a solids content of desirably not more than 2% by weight or at most 3 wt .-%) and not introduced into the thick pulp. therefore The flocculent HMW polymer can be added directly to the thick pulp or can be introduced into the dilution water, used to convert the thick pulp into thin pulp.

The flocculating HMW polymer comprises a means of aggregating the Solids, in particular fines, in the entry mass for Papermaking. The term "fines" as used herein refers to fine particulates and fibers defined in the TAPPI test method T261 and T269, respectively are.

The Flocculation of the fines of the furnish may be by the HMW polymer itself or in combination with a cationic coagulant high Charge density or the MMW flocculant become. The flocculation of the fines results in a better Retention of fines in the fiber structure of the resulting Paper sheet, and thus results in an improved drainage or water drainage.

The HMW flocculant is a polymer which is preferably characterized by himself for provides a flocculation effect.

Examples for flocculent HMW polymers suitable for use in the invention, are those having a weight average molecular weight of about 100,000, in particular 500,000 or more. This is preferably weight average molecular weight above about 1 million and often above about 1 million, and most typically in the range of 10 to 30 Millions or more. These polymers can linear, branched, cationic, anionic, nonionic, amphoteric or hydrophobically modified polymers of acrylamide or others nonionic monomers.

The Amount of HMW flocculant in the pulp or the An entry mass in the present invention introduced microparticle system can be any sufficient amount to have a significant effect when Flocculation of the solids, especially in the entry mass existing fines, to provide. The total amount of added water-soluble Polymer may range from about 0.0025% to about 1% by weight, more preferably in the range of 0.01% to 0.2% by weight, and most preferably ranging from about 0.0125% to about 0.1% by weight (dry weight of the polymer, based on the dry weight of the in the entry mass existing solids) are. The introduction can in one or take several doses at one or more dosing and preferably takes place in a single dose in the stream of thin pulp after the wing pump, whereby a high shear force is effected.

desirably For example, the flocs formed by the flocculating polymer become a Sheared before the silica-acid colloid mixture of the Microparticle system according to the invention is introduced. Preferably, this shear effect is by a Pressure screen triggered, which causes a high shear.

The particulate microparticle material according to the invention comprises in a preferred embodiment form a silica-acid colloid mixture, for example, such compositions as disclosed in the aforementioned US Pat. No. 5,382,378, the teachings of which are incorporated herein by reference. For example, the silica-acid colloid mixture according to the invention is comprised of a mixture of melamine aldehyde, urea aldehyde or melamine-urea aldehyde and colloidal silica. As described in U.S. Patent 5,382,378, a colloidal silica solution is a stable dispersion of discrete colloidally sized particles of amorphous silica in aqueous solutions. Colloidal silica solutions contain 5 to 50% SiO ₂ and have particle sizes of less than 1 micron. The stability of the colloidal silica solution depends on maintaining high electrostatic repulsion between the silica particles. The pH must be alkaline to maintain the negative charge on the silica particles to avoid agglomeration. The colloidal solutions are much less stable at low pH and prone to gelation.

suitable colloidal silica solutions for use in the invention have a particle size of less than 1 micron, preferably from 3 to 20 nm, and have 0.5 wt% to 50 wt .-% solids.

hergestellt, wobei R₁ aus der Gruppe ausgewählt ist, die aus geradem und aus verzweigtem C_1-4-Alkyl besteht. Dialdehyde können ebenfalls verwendet werden. Das Dialdehyd kann ein geradkettiges oder zyklisches sein, welches 2 bis 8 Kohlenstoffatome enthält, und C-substituiert sein und Heteroatome enthalten. Die bevorzugten Aldehyde sind Methanal (Formaldehyd), Ethanal, Propanal, Glyoxal und Glutaraldehyd. Das am meisten bevorzugte Aldehyd ist Formaldehyd.In a preferred embodiment, any melamine aldehyde-type polymer may be used for the acidic colloid component of the microparticle. This polymer is prepared by using a) melamine or a substituted melamine; and b) an aldehyde having the formula:

wherein R ₁ is selected from the group consisting of straight and branched C _1-4 alkyl. Dialdehydes can also be used. The dialdehyde may be a straight chain or cyclic containing 2 to 8 carbon atoms and C-substituted and containing heteroatoms. The preferred aldehydes are methanal (formaldehyde), ethanal, propanal, glyoxal and glutaraldehyde. The most preferred aldehyde is formaldehyde.

The molar ratio from component a) to component b) above should be in the range of about 1: 1 to about 1:10, wherein the preferred ratio is about 1: 3 to 1: 6. The most preferred molar ratio is about 1 mole of melamine or a derivative thereof to about 3 moles of an aldehyde. So it will the most preferred polymer made from melamine and formaldehyde, and the molar ratio of Melamine to formaldehyde is about 1: 3.

The melamine aldehyde-type polymer according to the invention is insoluble in water, but can be in aqueous solutions be kept in colloidal suspension. For the preparation of the melamine aldehydic acidic colloids of the particulate microparticle material according to the invention can any acid or compatible combination of acids, though used hydrochloric acid is preferred. The active content of the melamine aldehyde-type polymer in acidic suspension or solution should range from about 0.1% to about 20%, preferably 1% to about 15%, and most preferably from about 4% to about 12%. The pH should be in an aqueous inorganic or organic acid be sufficiently low and between 1.0 and 2.5 lie around the melamine aldehyde-like polymer in fine colloidal solution too hold.

Harnstoffaldehydartige Polymer solutions, which are suitable for use in the present invention are those in which the aldehyde is defined in the above manner, most preferably urea-formaldehyde solutions. The molar ratio of Urea to the aldehyde should be in the range of 1: 1 to 1:10, the most preferred ratio being from 1 3 to 1: 6.

Solutions of a Copolymers of melamine and urea aldehyde can be used in the present invention also be used. These solutions are made from the above described aldehyde component, urea and melamine or a substituted melamine produced. Preference is given to solutions of a copolymer of melamine-urea-formaldehyde. The for use in the present Invention suitable solutions the copolymer of melamine-urea-formaldehyde contain 1 to 70 mol% of urea, 30 to 99 mol% of melamine and about 1 to 4 moles of aldehyde for every mole of combined melamine and urea in the acidic aqueous Medium. The copolymer solution for use in the present invention is in the range of 0.1 to 20 percent solids, and preferably 1 to 12 percent Solids.

The acidic colloid may be a copolymer with melamine aldehyde and condensates, including amine aldehyde, dicyandiamide aldehyde, biguanidine aldehyde, urea-formaldehyde polyalkylene polyamine and polyu belong to reido.

The Acid colloid is formed by reaction of said aldehydes with the Amine and aging of the solution under acidic conditions and typically using hydrochloric acid produced. As aging proceeds, the colloidal ones grow Particles of a size of 20 to 200 angstroms. The average Degree of polymerization is 10 to 20 methylolated melamine units. The particle carries one cationic charge, i. some of the secondary amine units are protonated. The colloidal solutions have a characteristic blue turbidity. The solutions will be with a concentration of 8-12% Active substance kept. The solutions can exclusively composed of amine and aldehyde or may be derivatives thereof. The solutions can partly with an alcohol, glycol or another hydroxyl-containing Art be etherified. The solutions can a cocondensate of melamine-formaldehyde and another aminoplast which can then be etherified. The solutions can be a mixture of such Aminoplasts, which then used to form the acidic Kollids become. The colloid-forming aminoplasts may also be copolymers of ethylenic unsaturated Monomers such as acrylamide, dimethylaminoethyl acrylate, diallyldimethylammonium chloride (DADMAC) or methacrylamidopropyltrimethylammonium chloride and the like be.

at a preferred embodiment are similar Compositions of the microparticle according to the present invention those particles disclosed in U.S. Patent 5,382,378 which are incorporated by reference herein or become similar to them produced. The pH of the colloidal silica solution becomes first lowered to 1.3 to 2.0 using 10% hydrochloric acid. Then the acidic colloidal solution, For example, the melamine urea-aldehyde copolymer, added with stirring. The resulting mixture should have a pH of about 1.0 to 3.0 and preferably a pH of 1.5 have. The mixtures can total solids of 1.0 to 50%. In the invention become these silica-acid colloid mixtures as part of a microparticle system for a drainage, retention and Sheet forming program in relation to the production of paper or Cardboard applied.

The amount of silica-acid colloid in the microparticulate particulate material of the microparticle system according to the invention added to the paper or furnish may range between about 0.0005% and about 0.5%, and preferably about 0.005% to about 0 , 25% dry weight, based on the dry weight of the solids in the furnish. The introduction may be in one or more doses at one or more delivery sites, but preferably at one dose, and preferably after the pressure screen 2 in the single figure and at least between the printing screen 2 and the casserole 3 respectively.

The Silica-acid colloid blends of the microparticle system according to the invention includes colloidal silica and an acidic colloid, preferably Melamine formaldehyde acid colloids and derivatives thereof, in the manner described above.

The addition of the flocculating HMW polymer generally results in the formation of large flocs from the suspended solids in the paper or furnish to which the polymer is added. These large flakes are dissolved immediately or subsequently by high shear into small flakes, known in the art as "microflakes". This "high shear" can be achieved by passing the flocced furnish through the printing screen 2 be introduced according to the individual figure.

The water-soluble coagulant generally has a lower molecular weight than that prior to the printing screen 2 introduced into the pulp HMW flocculant and is preferably added to the pulp before the pulp through the vane pump 1 runs according to the individual figure. This coagulant is preferably a high charge density cationic polymer. For example, if the coagulating polymer is a nitrogen-containing cationic polymer, it may have a charge density of about 0.2, preferably at least 0.35 and most preferably 0.4 to 2.5 or more nitrogen equivalents per kilogram of polymer. When the polymer is optionally formed by polymerizing a cationic ethylenically unsaturated monomer with other monomers, the amount of cationic monomer is usually about 2 mole%, and usually about 5 mole%, and preferably at least about 10 mole%, based on the total amount the monomers used to form the polymer.

Suitable cationic coagulants are: polydiallyldimethylammonium chloride (p-DADMAC); polyalkylamines; cationic polymers of epichlorohydrin with dimethylamine and / or ammonia or other primary and secondary amines; polyamidoamines; Copolymers of a nonionic monomer, for example acrylamide, with a cationic monomer, for example DADMAC or acryloyloxyethyltrimethylammonium chloride; cyanoguanidine modified polymers of urea / formaldehyde resins; Melamine / formaldehyde polymers; Urea / formaldehyde polymers, polyethyleneimines; cationic starches; Monomers and polymers of cationic aluminum salts; amphoteric polymers with a net cationic charge; and mixtures of the aforementioned coagulants.

The Amount of the introduced into the pulp or the entry mass cationic coagulating polymer in the microparticle system according to the invention can be any sufficient amount to have a significant effect when Coagulate the existing in the paper or the entry mass To provide solids. The total amount of water-soluble coagulating polymer may range from about 0.0025 to 1% by weight, more preferably in the range of about 0.005 wt% to about 0.50 Wt .-% dry weight, based on the dry weight of solids present in the furnish.

If an MMW flocculant is to be used instead of the cationic coagulant, this flocculant may be introduced before the pulp is removed by the vane pump 1 passes through. Examples of an MMW flocculant suitable for use in the invention are those having a weight average molecular weight in the range of 500,000 to about 5 to 6 million. This chemical additive may be a copolymer of an acrylamide or an unsaturated monomer. A suitable MMW flocculant may include the copolymers ECCat ^™ 500 available from Calgon Corporation, PA.

The Amount of MMW flocculant may be any sufficient amount to have a significant effect when coagulating in the paper or the input mass to provide existing solids. The total amount of the MMW flocculant may be in the range of about 0.0025 to 1 wt .-%, based on the dry weight of solids present in the furnish. The dosages would in the range of 0.01 to 5.0 lb./t polymer.

As mentioned hereinabove, the cationic coagulant or MMW flocculant may be introduced into the thick pulp prior to the vane pump, the flocculating HMW polymer may pass through the vane pump after passing the thick pulp through it 1 can be introduced into the thin pulp, and the silica-acid colloid mixture according to the invention, after passing through the pulp through the printing screen 2 be introduced into the thin pulp according to the single figure. Alternatively, these chemical additives may be introduced into the thick pulp in a different order than that shown in the figure. That is, the silica-acid colloid mixture before. the wing pump 1 can be introduced, the HMW flocculant after the printing screen 2 can be introduced, and the coagulant or MMW flocculant before the printing screen 2 be introduced. There may be other orders at the feeders for the chemical additives in the paper machine.

Of the initial Thick pulp can be made from any conventional papermaking pulp produced, for example, traditional chemical pulps such as bleached or unbleached sulphate or sulphite pulp, mechanical pulps such as groundwood; thermomechanical pulp; or chemical-thermochemical pulp; or recycled Pulp like discolored Waste, fibrous fillers from aggregation or Recycling operations; and all mixtures thereof.

The Furnish or pulp used in the invention can, and the finished paper can essentially unfilled (i.e., less than 10% by weight, and generally less than 5% by weight of filler contain), or with a filler filled be in an amount up to 50%, based on the dry weight the solids in the furnish, or up to 40 wt .-%, based on the dry weight of the paper, can be provided. If filler Any conventional can be used white pigment filler such as calcium carbonate, kaolin clay, calcined kaolin, titanium dioxide or talc or a combination thereof. Of the filler (if any) is preferably in a conventional manner and before Adding the components of the microparticle system according to the present invention Invention introduced into the entry mass.

The furnish or pulp used in the invention may also contain other known optional additives such as rosin, alum, neutral glues or optical brightening agents. She / he may contain a reinforcing or binder, and this can beispielswei It can be a starch like cationic starch. The pH of the furnish is generally in the range of about 4 to about 9.

The Quantities of fiber, filler and other additives, such as reinforcing agents or alum, all conventional be. Typically, the thin one Papierbrei a solids content of 0.1 to 3 wt .-% or a Fiber content of 0.1 to 2 wt .-% to. The thin pulp usually has a solids content from 0.1 to 2% by weight. These percentages are based on dry weight the solids in the entry mass.

As explained further above, includes those as the disperse microparticle material in the microparticle system according to the invention used silicon acid colloid mixture colloidal silica and an acidic colloid or derivatives the same. Preferably, the acidic colloid comprises an aqueous solution of a water-soluble one Polymer, which is preferably a melamine aldehyde and preferably Melamine formaldehyde is. This disperse material dissolves easily in an aqueous Pulp suspension in a papermaking process to the surface properties improve the finished paper product.

The Inventors found that the silicon acid-colloid mixtures were in combination with a HMW flocculant by itself or with a Coagulant or an MMW flocculant drainage and increase retention and improve sheet-forming in a papermaking process can.

experiments

• Polymer A: 25 Gew.-% betragendes aktives Copolymer von Acrylamid und Acryloyloxyethyltrimethylammoniumchlorid, erhältlich von der Calgon Corporation (Pittsburg, PA), mit etwa 90 Mol-% Acrylamid und etwa 10 Mol-% Acryloyloxyethyltrimethylammoniumchlorid.
• Polymer B: anionisches Ausflockungsmittel – 28 Gew.-% betragendes aktives anionisches Copolymer von Acrylamid und Acrylsäure, erhältlich von der Calgon Corporation (Pittsburg, PA), mit etwa 70 Mol-% Acrylamid und etwa 30 Mol-% Acrylsäure.
• Polymer C: kationisches Copolymer mittleren Molekulargewichts von Acrylamid und Diallyldimethylammoniumchlorid, erhältlich von der Calgon Corporation (Pittsburg, PA).
• Polymer D: Terpolymer mittleren Molekulargewichts von Acrylamid, Diallyldimethylammoniumchlorid und Acrylsäure, erhältlich von der Calgon Corporation (Pittsburg, PA).
• Saures Melaminformaldehydkolloid (MF): 8%-ige aktive Lösung, erhältlich von der Calgon Corporation (Pittsburg, PA).
• Kolloidales Siliciumdioxid: 15%-ige aktive Lösung, erhältlich von DuPont (Wilmington, DE).
• Carbital 60: trockenes, gemahlenes Calciumcarbonat, erhältlich von ECC International Inc. (Atlanta, GA).
• Stalok^® 400: (Nationales Warenzeichen von A.E. Staley) und Interbond C: kationische Stärken, erhältlich von A.E. Staley.
• Hercon 70: AKD-Leim (Alkylketendimer-Leim), erhältlich von Hercules, Inc.

The following examples demonstrate the invention in more detail and are not intended to limit the scope of the invention in any way. In these examples the following products were used:

• Polymer A: 25% by weight active copolymer of acrylamide and acryloyloxyethyltrimethylammonium chloride, available from Calgon Corporation (Pittsburg, PA), with about 90 mole% acrylamide and about 10 mole% acryloyloxyethyltrimethylammonium chloride.
• Polymer B: anionic flocculant - 28 wt% active anionic copolymer of acrylamide and acrylic acid, available from Calgon Corporation (Pittsburg, PA), with about 70 mole percent acrylamide and about 30 mole percent acrylic acid.
• Polymer C: medium molecular weight cationic copolymer of acrylamide and diallyldimethylammonium chloride, available from Calgon Corporation (Pittsburg, PA).
• Polymer D: Medium molecular weight terpolymer of acrylamide, diallyldimethylammonium chloride and acrylic acid, available from Calgon Corporation (Pittsburg, PA).
• Acid melamine-formaldehyde colloid (MF): 8% active solution, available from Calgon Corporation (Pittsburg, PA).
• Colloidal Silica: 15% Active Solution, available from DuPont (Wilmington, DE).
• Carbital 60: dry, ground calcium carbonate available from ECC International Inc. (Atlanta, GA).
• Stalok ^® 400: (National trademark of AE Staley) and Inter Bond C: cationic starches available from AE Staley.
• Hercon 70: AKD size (alkyl ketene dimer glue) available from Hercules, Inc.

Examples 1-16 - Alkaline Fine paper furnish

Production of the entry mass

An alkaline fine paper load was prepared and used for drainage and retention tests and for the preparation of test sheets. This entry mass was manufactured with the following components: Fiber: 50/50 wt.% Bleached kraft hardwood / bleached Kraft softwood filler 50/50 wt.% Ground calcium carbonate (Carbital 60) / precipitated calcium carbonate Füllstoffcharge: 20 wt .-%, based on the fiber solids Strength: 0.5 wt .-% (Interbond C), based on the fiber solids Glue: 0.25% by weight Hercon 70 (AKD)

A dry pulp in sheet form was soaked in lukewarm water for 10 minutes, with Water to a consistency of 2% solids by weight and refined or ground to a standard Canadian grind (CSF) of 590 ml with a laboratory Voith Allis Valley Grinder. Starch, size and filler were added in this order to the refined pulp suspension. The pH of the pulp suspension was typically 7.5 ± 0.3. The pulp suspension was further diluted with tap water to a consistency of approximately 1.0% by weight to make a thin pulp for drainage and retention tests and to prepare test sheets. The furnish is representative of a typical alkaline fine paper load as used to make printing paper and writing paper.

Drainage test method

• 1. There were 200 ml (2 g solids) of the entry mass with 1% by weight of resistance poured into a square mixing bowl in the casserole and diluted to 500 ml with tap water.
• 2. These ingredients were mixed using a standard Britt propeller mixer (1 inch diameter) with the following mixing time conditions (in seconds) and speed conditions (in rpm) to allow chemical introduction into the secondary inlet of the vane pump, the outlet of the vane pump and to simulate the outlet of the printing screen:
  
• 3. The ingredients in the mixing cup were graduated into a 500 ml dehydration tube transferred, which on the ground with a sieve with the mesh 100 was equipped. The tube was inverted 5 times to make sure the mass was homogeneous is. The bottom plug of the tube was removed and elution times for elution volumes of 100, 200 and 300 ml measured. The elution time at a volume of 300 ml with an untreated raw material should preferably be longer than Be 60 seconds.
• 4. The improvement in dewatering was calculated in the following manner with respect to the dewatering time of an untreated crude sample:
  

Retention test method (FPR, FPAR) -TAPPI test method T269

• 1. There were 500 ml of the entry mass with (1 % By weight) resistance in the casserole in a Britt-Pecher with a sieve with the mesh size 70 poured in, wherein the mass was stirred at 1200 rev / min.
• 2. The order of mixing time (in seconds) / speed (in rpm) was similar to that in the above dewatering test procedure to simulate chemical feed points with the following change: At t ₃₀ , the lower stopcock was opened and the first 10 ml of the eluate.
• 3. This eluate was passed through Whatman # 4 filter paper filtered and at 105 ° C dried.
• 4. The mass cake was burned for 2 hours at 600 ° C, to determine the ash retention.

Production and test of the test sheet

With Help of a test sheet form from Noble & Wood were test sheets with a basis weight made of 7) grams per square meter. This device presents a square test sheet of 20 cm × 20 cm ago. The sequence used in the preparation of the test sheets Mixing time / speed was the same as that in the dehydration test procedure used sequence. The treated entry mass sample was added to the Adding bounding box the test sheet machine from Noble & Wood poured in, and the bow was made by the skilled person well-known standard methods.

properties of the bow

With Help of a MK system forming tester model MK 95OR was the molding tested on the test sheets. With the help of a device Technidyne Color Touch's ISO model has been used for whiteness and opacity measurements performed.

manufacturing of the mixtures

• 1) Es wurden die Mengen der kolloidalen Siliciumdioxidfeststoffe und der sauren kolloiden Feststoffe in den Verhältnissen von Tabelle 1 berechnet, und es wurden die festgelegten Mengen für jede Lösung in gesonderte Becher eingewogen.
• 2) Es wurde eine pH-Sonde, die an einem pH-Messgerät angebracht war, in die kolloidalen Siliciumdioxidlösung eingeführt. Der pH-Wert dieser Lösung wurde durch Zusetzen von 10%-iger Salzsäure auf etwa 1.5 abgesenkt.
• 3) Die saure Kolloidlösung wurde in die kolloidale Siliciumdioxidlösung eingebracht, und dabei wurde die kolloidale Siliciumdioxidlösung umgerührt. 4) Der pH-Wert der fertigen Mischung gemäß 3) oben wurde durch Zusetzen von 10%-iger Salzsäure auf 1.5 abgesenkt.

The colloidal silica-acid colloid mixtures were prepared according to the following procedure:

• 1) The amounts of colloidal silica solids and acidic colloidal solids in the ratios of Table 1 were calculated and the set amounts for each solution were weighed into separate beakers.
• 2) A pH probe attached to a pH meter was introduced into the colloidal silica solution. The pH of this solution was lowered to about 1.5 by adding 10% hydrochloric acid.
• 3) The acidic colloid solution was introduced into the colloidal silica solution, thereby agitating the colloidal silica solution. 4) The pH of the final mixture according to 3) above was lowered to 1.5 by adding 10% hydrochloric acid.

In Table 1 is the ratio the compositions for Composed the mixtures of silica and melamine formaldehyde (MF). those in Examples 1-16 were used.

Table 1 Composition of the mixtures

Examples 1-7

table 2 shows the results of drainage for the Examples 1-7, and Table 3 shows the results of retention for these same examples 1-7. Examples 2 and 4 particularly show the effectiveness of the use a silica MF mixing ratio of 4: 1.

Drainage:

The Dosages in Examples 1-7 are considered active with respect to to 1 lb / t dry pulp. The information in table 2 show the effectiveness of the Silica-MF blend ratio from 4: 1 at the raise the drainage rate the entry mass. As indicated in Example 2, reinforced by the use of 1.0 lb / t of the mixing ratio of 4: 1 dewatering, i.e. the drainage rate according to example 2, in which the silica-MF mixing ratio of 4: 1 shows an increase compared to Example 1, i. a drainage rate of 57% in Example 2 compared to a drainage rate of 39% in Example 1. As in Examples 3 and 4 in Table 2 apparent, was the drainage through further increases of the 4: 1 silica MF mixing ratios elevated, i.e. 65% in Example 3 and 68% in Example 4.

The Silica-MF blend ratio 4: 1 (Example 4) also worked better than the silica at similar Doses of 2.0 lb / t and with less strength by itself (example 7), i. at 5 lbs./t in example 4 in comparison at 15 lbs./t in example 7, if the entry mass at the inlet too the wing pump was introduced. This is important for the paper manufacturer Save money by using the amount of starch needed in the papermaking system reduced.

Table 2 Improvement of dewatering with 4: 1 mixture

retention:

In Table 3 is the ability of the silica MF mixing ratio of 4: 1 according to the invention for increase retention at first pass (FPR) and ash retention on the first pass (FPAR) in a drainage / retention / shaping program specified. The retention was determined by the Britt method (TAPP test method T269) with the mixing sequences mentioned here above. Example 1, in which no dispersed microparticle material included has an FPR of 85.2%. As shown in Example 4 2 lbs./t of the silica MF blend ratio 4: 1 added, the FPR increased to 92.9%, and the FPAR increased from 61% (Example 1) to 80.1% (Example 4). These Increases in FPR and FPAR can therefore be important factors for the Paper manufacturers say that the paper making process is more effective becomes, the use of fillers can be reduced and improves the properties of the bows can be. In turn, due to the silica: MF mixing ratio of 4: 1 less strength can be used and thereby Results similar the examples using only silica, i. example 3 (mixture 4: 1) compared to Example 6 (silica), be achieved.

Table 3 Retention of the mixture 4: 1

Examples 8-12: Mixture 1: 1

table 4 shows the drainage results for the Examples 8-12, and Table 5 shows the retention results for Examples 8-12. These Results show the effectiveness at the reinforcement of drainage and retention when the dosage of the silica MF mixing ratio from 1: 1 in Table 1 from 1.0 lbs./t to 2.0 lbs./t. This mixing ratio 1: 1 and the silica-MF mixing ratio of 4: 1 are more similar Such as silica, but at a lower level of starch, i.e. 5 lbs./t compared to 15 lbs./t for silica.

Table 4 Dewatering with 1: 1 mixture

Table 5 Retention of the mixture 1: 1

Examples 13-16: Mixture 1: 4

table 6 shows the drainage results and Table 7 shows the retention results for Examples 13-16. These Results show an improvement of drainage and retention when the silica-MF mixing ratio of 1: 4 in Table 1 in the DRF program. Improve again As can be seen in Tables 6 and 7, drainage and retention when the silica-MF mixing ratio of 1: 4 is used, i. Examples 14-16 compared to Example 13 were used in which no mixture was used.

Table 6 Dewatering with 1: 4 mixture

Table 7 Retention of the mixture 1: 4

Stability of the mixtures:

As Table 8 shows the different silica-MF mixing ratios depending on the composition different stabilities at a pH of 2.0 on. The following findings were made.

Table 8 Stability of the mixtures

As the silica-MF mixing ratio of 1: 4 is shown the acidic colloid the longer at acidic pH, i. longer than 180 days, the more of them are in the mix. The 12% MF were made by concentrating a total solution of 8% solids brought about. The mixtures according to the invention have a lot better stability as each of the components in a disconnected state, i. 15 and 90 days opposite 150 days or more in the silica-acid colloid mixtures according to the invention.

Examples 17-21: Easy coated (LWC) entry mass

at the remainder of the examples was a silica-MF mixing ratio of 9: 1 (w / w solids) at 15% solids in total. The silica used was a 30% solids silica, available from DuPont (Wilmington, DE). The mixtures were continued in here prepared as described above.

The Examples 17-21 in Tables 9-A and 9-B illustrate the effectiveness of the present invention Invention in improving drainage, retention. and bow features a synthetic, aqueous Entry mass. This entry mass represents a typical entry mass as used to make a base sheet for lightly coated grades becomes. The entry mass was 15 minutes long with 15 lb./t of starch Stalok 400 treated before retention aids were added.

Preparation of the entry mass:

The synthetic furnish used for dewatering and retention and for making test sheets was prepared with the following components: Fiber: 45% by weight bleached kraft softwood (SWK) 55% by weight chemithermomechanical pulp (CTMP) filler calcined clay Füllstoffcharge: 10% by weight, based on the weight of the oven-dried fibers Alum: 0.5% by weight, based on the weight of the oven-dried fibers

at For the preparation of the entry mass, the CTMP was 15 to 20 minutes long in hot Water soaked, diluted in water to 1.5 wt .-% solids and with a laboratory-based Voith Allis Valley grinding machine Refined to a standard Canadian degree of granulation (CSF) of 200 ml or ground. The SWK was separately soaked in water, on Diluted 1.5 wt .-% solids and refined or ground to a CSF of 550 ml. Then were the above fibers are mixed to the proportions listed above, and the calcined clay was added. The pH of the entry mass was diluted with sulfuric acid set to 5.0, and the conductivity was with sodium sulfate to 2000 μS / cm set.

Table 9-A LWC record mass

Table 9-N LWC record mass

The Examples 18-21 in Tables 9-A and 9-B show the effect of introduction of the microparticle mixture in the LWC entry mass in one position after the sieve. If the dosage of the microparticle mixture is increased, take drainage, FPR and FPAR very strong too. These benefits can be important that the paper maker the speed of the paper machine increase can make the bow dry faster and more of the fillers and the fines of the entry mass compared to one not with the microparticle system according to the invention treated bow is held in the bow. The results in Tables 9-A and 9-B also show that sheet formation at Use of the invention decreases while whiteness and opacity of the bow compared to one not with the microparticle system according to the invention treated bow relatively unchanged stay.

Examples 22-26: Cardboard Inlet

The Examples 22-26 in Tables 10-A and 10-B illustrate the effectiveness of the invention in the improvement of drainage, Retention and bow properties of a synthetic, aqueous Card paste mass. This entry mass represents a typical Mass such as that used to make a base sheet for cardboard is used.

Preparation of the entry mass:

It was an entry mass by dissolving 360 g unbleached old corrugated board (OCC) in lukewarm water and diluted with Tap water made to 23 liters. Then the pulp became with a laboratory milling machine similar to the previous examples to a CSF of 300 ml. 18 liters this slurry was diluted to a consistency of 0.5% by weight, and to adjust the water chemistry to paper mill conditions the following salts were added: 5.61 g calcium chloride; 0.96 g of potassium chloride; 8.17 g of alum (50% by weight); 15.96 g of sodium sulfate; 0.59 g of sodium bicarbonate; and 0.97 g of sodium silicate. The measured conductivity was approximately 2000 μS / cm. Of the pH was diluted with dilute sulfuric acid set to 5.0.

Table 10-A Cardboard load

Table 10-B Cardboard mass

In In Tables 10-A and 10-B, Examples 22, 25 and 26 illustrate Effect of using 20 pounds of starch in conjunction with the microparticle blend according to the invention in a paperboard furnish. Tables 10-A and 10-B show also that by an increase in the dosage of the microparticle mixture according to the invention and the starch drainage, FPR and FPAR increase. These results also show that the microparticle mixture also works well when using 10 pounds of starch in the pickup mass become. This seems to indicate that in the invention no high strength grade Need to be effective to take effect on some entry mass to be. It has been shown that in traditional silica programs typically high starch dosages necessary are to be effective, whereas when using the microparticle system according to the invention does not seem to be the case.

Examples 27-30: Newsprint paper

Examples 27-30 in Tables 11-A, 11-B, and 11-C illustrate the effectiveness of the invention in improving drainage, retention, and sheet properties of a synthetic, aqueous one This furnish is a typical wood pulp furnish used to make a base sheet for newsprint.

Preparation of the entry mass:

The synthetic furnish used for drainage and retention tests and for the preparation of test sheets was prepared as follows: Fiber: 80% by weight of CTMP 10% by weight SWK 10% by weight of recycled newsprint Filler: calcined clay Füllstoffcharge: 4% by weight, based on the weight of the oven-dried fibers Alum: 50 lb./t

at The preparation of this entry mass was the CTMP in hot water (140 ° C) soaked and degreased in a blender for 15 to 20 minutes. The recycled newsprint was separately on the same Treated way. The SWK was in lukewarm water for two hours soaked and degreased in a blender for 15 to 20 minutes.

Of the CTMP, the recycled newsprint and the SWK were together mixed and similar to a laboratory milling machine previous examples to a CSF of 50 to 75 ml. The calcined clay and alum were added to the final pH from 4.8 to 5.2. The conductivity of the slurry was adjusted to 2000 μS / cm using sodium chloride.

Table 11-A Newsprint

Table 11-B Newsprint paper mass

Table 11-C Newsprint

In Tables 11-A and 11-C illustrate Examples 27 and 28, that an increase in drainage, FPR and FPAR occur when the microparticle mixture according to the invention in the position after the screen in the newsprint paper mass is introduced. This increase in drainage, FPR and FPAR can an important consideration in a very fast moving newsprint machine be. These results for Examples 27 and 28 also show that the microparticle system even without strength is effective. These factors allow the paper maker to use the Reduce costs and thereby the total cost per tonne of the produced Lower paper.

Industrial application the machine for alkaline fine paper

The Performance of the machine became on an industrial machine for alkaline Fine paper rated. The microparticle blending program according to the invention was compared with a reference program. The reference program was running on a machine, in which the polymer B (0.15 lb./t active) was added before the sieve and polymer C (1.0 lb./t active) of the furnish was added after the sieve. In the microparticle program according to the invention polymer C of the furnish was in the step before the sieve and the microparticle mixture (1.0 lb. active) was added added in the step after the sieve. It should be noted that the Dosages approximate are and with different basis weight and different Paper type changed wrden. The program according to the invention was also compared to a typical silica program, wherein polyamine (1.5 lb./t active) was added to the vessel, anionic HMW polyacrylamide (1.5 lb./t active) in the step before the sieve was added and colloidal silica (1.5 lb./t active) was added in the stage after the sieve. The results of this Comparisons are shown in Tables 12 and 13.

Table 12 Comparison of paper machines at 80 lb. grammage

Table 13 Comparison of paper machines at 100 lb. grammage

Out Table 12 (basis weight 80 lb.) it can be seen that the microparticle mixture according to the invention to improved bowing (the lower number is better), too lower steam consumption and more pressed solids in the Comparison with the other programs leads. With equivalent steam consumption the speed of the machine with the invention was increased by 13.6% across from the Reference Program and 3.1% compared to the traditional silica program elevated. By this factor, the paper machine manufacturer can speed up increase the machine, which is higher Production of paper and / or less energy for steam production leads. These results also indicate better paper forming when the microparticle mixture according to the invention is used. This factor can be important for that make a paper sheet with a more consistent, higher quality.

In Table 13 (basis weight 100 lb.) is a comparison between the use of the microparticle mixture according to the invention and the use of other programs on a paper of 100 lb. grammage shown. For a heavier weight paper, drainage more problematic in the thicker bow, and drying is more Energy needed. It has been shown that with the invention for better arching, more pressed solids and lower steam consumption compared to the reference program or the silica program becomes. These factors of the invention may make it difficult for the papermaker allows be, a bow of higher quality with a higher one Paper machine speed produce.

Though were for the illustrative purposes are specific embodiments of the present invention However, it will be apparent to those skilled in the art that: numerous variations and details of the invention without deviation of the invention as defined in the appended claims can be.

Claims (20)

A microparticle composition used as a holding and draining aid in a furnish, comprising: a) a high molecular weight flocculating polymer present in an amount of from 0.0025% to 1.0% by weight, based on Dry weight of solids in the furnish, and b) a silica-acid colloid mixture comprising (1) an acidic colloid consisting of melamine-type aldehyde polymers, (2) a colloidal silica, wherein the acidic colloid and the colloidal silica are in the range of, respectively 99.5: 0.5 to 0.5: 99.5, by total solids, in an acidic environment having a pH of 3.0 or less, the silica-acid colloid mixture being in an amount from 0.0005% to 0.5% by weight is, based on the dry weight of the solids in the entry mass. The composition of claim 1, wherein the melamine is substituted or unsubstituted in the melamine-type aldehyde polymer; and the aldehyde

wherein R ₁ is selected from the group consisting of straight and branched C _1-4 alkyl. A composition according to claim 2, wherein the aldehyde selected from the group is made up of formaldehyde, ethanal, propanal, glyoxal and glutaraldehyde consists. A composition according to claim 3, wherein the aldehyde Formaldehyde is. A composition according to claim 4, wherein the water-soluble polymer Melamine formaldehyde is. A composition according to claim 5 wherein the melamine formaldehyde is etherified with a linear or a branched alcohol. The composition of claim 1, wherein the silica-acid colloid mixture is colloidal Silica and an acidic colloid of a copolymer of melamine-formaldehyde and urea-formaldehyde. The composition of claim 1, wherein the silica-acid colloid mixture is colloidal Comprising silica and an acid colloid of a copolymer, which comprises the melamine aldehyde and condensates selected from the group selected from ammelinaldehyde, dicyandiamide aldehyde, biguanidine aldehyde. Urea-formaldehyde, polyalkylenepolyamine and polyureido. The composition of claim 1, wherein the silica-acid colloid mixture is the colloidal silica and a colloid of a copolymer of amine-aldehyde-type and ethylenically unsaturated Comprising monomers selected from the group consisting of acrylamide, Dimethylaminoethyl acrylate, diallyldimethylammonium chloride and methacrylamidopropyltrimethylammonium chloride consists. The composition of claim 1, further comprising: one cationic coagulants of high charge density, which in one Amount of about 0.005 wt .-% to about 0.5 wt .-% is present on the dry weight of the solids in the furnish. The composition of claim 1, further comprising: one Flocculants of average molecular weight, in an amount from 0.0025 wt% to about 1.0 wt%, based on the dry weight of the solids in the furnish. Paper product with the microparticle composition according to claim 1. Paper product with the microparticle composition according to claim 2. Process for the production of paper products with the following steps: a) after a first high shear stage and before a second high shear stage, the introduction of a flocculent The high molecular weight polymer of claim 1 in a paper furnish in an amount of from 0.0025% to about 1.0% by weight, based on the dry weight of the solids in the furnish; and b) before or after the second high shear stage introducing a Silica acid colloid mixture after Claim 1, which is present in an amount of from 0.0005% by weight to about 0.5% by weight. is present, based on the dry weight of the solids in the entry mass, into the paper entry mass. The method of claim 14, further comprising following step: a) before the first high shear stage, the introduction a cationic coagulant of high charge density in one Amount of from about 0.005 wt% to about 0.5 wt%, based on the Dry weight of solids, in the entry mass. The method of claim 14, wherein the silica-acid colloid mixture from melamine-formaldehyde-acid colloid consists. The method of claim 14, further comprising following step: a) before the first high shear stage, the introduction a polymer of average molecular weight in the entry mass in an amount of from 0.0025% to about 1.0% by weight, based on the dry weight of the solids in the furnish. The method of claim 17, further comprising following step: a) before the first high shear stage, the introduction a cationic coagulant of high charge density in the Inlet weight in an amount of about 0.005 wt .-% to about 0.5 Wt .-%, based on the dry weight of the solids in the entry mass. The method of claim 17, wherein the silica-acid colloid mixture from melamine-formaldehyde-acid colloid consists. The method of claim 17, further comprising following step: a) before the first high shear stage, the introduction a polymer of average molecular weight in the entry mass in an amount of from 0.0025% to about 1.0% by weight, based on the dry weight of the solids in the furnish.