TW568884B - Silica-based sols and silica-based particles, their production and use - Google Patents

Abstract

The invention relates to a process for the production of an aqueous sol containing silica-based particles which comprises (a) acidifying an aqueous silicate solution to a pH of from 1 to 4 to form an acid sol; (b) alkalising the acid sol at an SiO2 content within the range of from 4.5 to 8% by weight; (c) allowing particle growth of the alkalised sol for at least 10 minutes; or heat-treating the alkalised sol at a temperature of at least 30 DEG C; (d) alkalising the obtained sol to a pH of at least 10.0; and (e) optionally concentrating the sol obtained according to (b), (c) or (d) to provide an aqueous sol containing silica-based particles and having a specific surface area of at least 90 m<2>/g aqueous sol; as well as an aqueous sol containing silica-based particles obtainable by the process. The invention also relates to an aqueous sol containing silica-based particles which sol has a specific surface area of at least 115 m<2>/g aqueous sol and an S-value within the range of from 10 to 45% or contains silica-based particles having a specific surface area of at least 550 and less than 1000 m<2>/g SiO2. The invention further relates to the use of the aqueous sol containing silica-based particles as a drainage and retention aid in the production of paper as well as a process for the production of paper from an aqueous suspension containing cellulosic fibres, and optional filler, in which silica-based particles and at least one charged organic polymer are added to the cellulosic suspension.

Description

568884 A7 ___________B7__________ V. Description of the invention, preferably a water-soluble sol of at least 85 square meters per gram, more preferably a water-soluble sol of at least 90 square meters per gram, and most preferably at least 95 square meters M / g water soluble sol. In a preferred embodiment of the present invention, the specific surface area of the water-soluble sol mainly composed of silica is suitably a water-soluble sol of at least 115 m 2 / g, more preferably at least 120 m 2 / g Water-soluble sol. Generally, the specific surface area of the water-soluble sol may be as high as about 200 square meters / gram of water-soluble sol, suitably as high as 150 square meters / gram, and preferably as high as 13 square meters / G of water-soluble sol. The specific surface area of the silica-based particles is suitably at least 300 square meters per gram of Si02, that is, based on the weight of SiO2, preferably at least 400 square meters per gram of Si02, and the best It is at least 550 square meters / gram Si02. In general, the specific surface area of the particles can be as high as about 1200 square meters / gram SiO2, suitably less than 1000 square meters / gram SiO2, and preferably as high as 950 square meters / gram SiO2. In a preferred embodiment of the present invention, the specific surface area of the particles is in a range from 550 to 725 m 2 / g Si 2, preferably from 575 to 700 m 2 / g Si 2. . In another preferred embodiment of the present invention, the specific surface area of the particles is in a range from 775 to 12,000 m 2 / g Si 2, preferably from 800 to not less than 1000 m 2 / Gram si 〇 2 〇 Example: by Sears in Analytieai Chemistry, Volume 28 (1956): Volume I2, pages 1981-1983, and in US Patent No. 5,176,891 It is described in the appropriate removal 7 (Please read the precautions on the back before filling this page) · Installed by the Intellectual Property Bureau of the Ministry of Economic Affairs Employee Cooperatives Printed on paper This paper applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 568884 A7 B7 V. Description of the invention (female) or adjustment of any compounds present in the sample that interfere with the titration, such as aluminum and boron species, the specific surface area can The known method is measured by NaOH titration. When expressed in square meters per gram of water-soluble sol, the specific surface area represents the specific surface area available per gram of silica-based water-soluble sol. When expressed in square meters per gram of silica, this specific surface area represents the average specific surface area of the silica-based particles present in the sol. Generally, silica-based sols have S- 値 in the range from 10 to 45%, suitably from 20 to 40%, and preferably from 25 to 35%. The S-fluorene can be measured and calculated as described by Iler and Dalton in the Journal of Physical Chemistry (J. Phys. Chem.) Vol. 60 (1956) pages 955-957. The S- 値 indicates the degree of coagulation or microgel formation, and a lower S- 値 indicates a higher degree of coagulation. Silica-based sols usually have a molar ratio of Si02 to M20 of at least 10: 1, where M is an alkali metal ion (for example: Li, Na, K) and / or ammonium, suitably at least 12: 1, And preferably at least 15: 1. The molar ratio of SiO2 to M2O can usually be as high as 100: 1, suitably as high as 40: 1, and preferably as high as 30: 1. The preferred range is therefore from 10: 1 to 100: 1, and especially from 15: 1 to 30: 1. Silica-based sols generally have a pH of at least 8.0, suitably at least 10.0, preferably at least ι · 5, and more preferably at least 10.6. The pH can be as high as about 11.5, suitably as high as 11.0. The silica-based sol must suitably have a silica content of at least 3% by weight, but more suitably a sandstone content in the range from 10 to 30% by weight. And preferably from 12 to 25% by weight. In order to simplify transportation and reduce 8 ^ paper size applies Chinese National Standard (CNS) A4 specifications (210 X 297 mm) one (please read the precautions on the back before filling this page) 568884 A7 B7 V. Description of the invention ) Less transportation costs, it is usually better to transport high concentration silica-based sols, but of course it is possible, and it is usually better to 'dilute and mix silica-based sols and particles before use, To greatly reduce the content of silica, for example: the content of sand and gravel is in the range from 0.05 to 5% by weight to improve the mixing with the equipment components. The viscosity of silica-based sols can vary depending on, for example, the silica content of the sol. Generally, the viscosity is at least 5 centipoise (cP), generally in the range from 5 to 40 centipoise, suitably 6 to 30 centipoise, and preferably 7 to 25 centipoise. Has a silica content of at least 10 weights. The viscosity measured on the sol can be measured by known techniques, for example: using a Brookfield LVDV Π + viscometer. The silica-based sol of the present invention is preferably stable. As used herein, the term "stabilized silica-based sol" means that when stored or aged for one month at 20 ° C in the dark and without stirring, it shows an increase in viscosity of less than 100 Centipoise is a silica-based sol. When the sol is subjected to the above conditions, if there is any increase in viscosity, it is suitably less than 50 centipoise, and preferably less than 30 centipoise. In a preferred embodiment of the present invention, the silica-based solvent is almost free of aluminum, that is, there is no added modifier containing aluminum. In another preferred embodiment of the present invention, the silica-based sol is almost free of boron, that is, there is no added modifier containing boron. However, small amounts of these elements are present in the starting materials used to prepare silica-based sols and particles. In another preferred embodiment of the present invention, the silica-based sol is modified with different elements, such as: aluminum and / or boron, which can exist in 9 paper sizes and is applicable to Chinese National Standards (CNS) A4 size (210 X 297 mm) (Please read the precautions on the back before filling this page)

T. Ϋ i · — · ϋ ^ ^ · ϋ —Bi ϋ ^ 1 ϋ I Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 568884 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the Invention (7) Water Phase and / or silica-based particles. If aluminum is used, the mol ratio of Al203 to SiO2 that the sol may have is in the range from 1: 4 to 1: 1500, suitably from 1: 8 to 1: 1000, and is preferably It is from 1:15 to 1: 500. If boron is used, the sol may have a molar ratio of B to SiO2 in the range from 1: 4 to 1: 1500 ', suitably from 1: 8 to 1: 100G, and preferably It is from 1:15 to 1: 500. If both aluminum and boron are used, the molar ratio of A1 to B ranges from 100: 1 to 1: 100, suitably from 50: 1 to 1:50. The silica-based sol and particles according to the present invention can be produced from a conventional water-soluble silicate solution, such as starting from alkaline water glass, for example, potassium or sodium water glass, preferably sodium water. glass. Si02 to M20 mole ratio in silicate solution or water glass, where M is an alkali metal ion 'such as sodium, potassium, ammonium or mixtures thereof, suitably in the range from 1.5: 1 to 4.5: 1 Within, it is preferably from 2.5: 1 to 3.9: 1. A dilute silicate solution or water glass is suitably used, which may have a SiO2 content of from about 3 to about 12% by weight, preferably from about 5 to about 10% by weight. A silicate solution or water glass, which typically has a pH of about 13 or higher, is acidified to a pH of from about 1 to about 4. Acidification can be performed in a known manner by adding mineral acids, such as: sulfonic acid, hydrochloric acid, and phosphoric acid, or optionally other chemicals known to be suitable for acidifying water glass, such as ammonium sulfate and carbon dioxide. When mineral acid is added, the acidification is suitably performed in two steps. The first step is a pH of about 8 to 9, which has some maturity, that is, the growth of particles, allowing further acidification to a pH of from about 1 to about 4 happened before. However, the acidification is preferably carried out through an acid cation exchanger. Among other things, it results in the Chinese National Standard (CNS) A4 specification (210 X 297 mm) being applied to 10 paper sizes. C Please first Read the notes on the back and fill in this page &gt;

568884 A7 B7 V. Description of the invention (g) (Please read the notes on the back before filling this page) Stable product. Acidification is preferably performed by strong acid cation exchange resins, for example: sulfonic acids. Preferably, the acidification is carried out to a pH of from about 2 to 4, and most preferably from about 2.2 to 3.0. The resulting product, acid sol or polysilicic acid, contains silica-based particles with a high specific surface area, typically higher than 1,000 square meters per gram of Si02, and usually about 1300 to 1500 square meters. Feet / gram Si02. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs and then the acid sol is alkalized, which is referred to herein as the first alkalizing step. The first alkalizing step is performed by adding conventional alkalis, such as: lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide and mixtures thereof, and / or a water-soluble silicate solution as defined above. Potassium and sodium water glass, especially sodium water glass, have a molar ratio of Si02 to M20 as defined above, and are suitably used in the alkalizing step. The SiO2 content of the water glass solution used in the first alkalizing step is suitably used in a range from about 3 to about 35% by weight, and more preferably in a range from 5 to 30% by weight. The first alkalization step is usually carried out at a pH of at least 6, suitably at least 7, and preferably at least 7.5, and the pH is usually as high as 10.5 and suitably as high as 10.0. The first alkalinization step is further suitably performed until the final SiO2 to M20 molar ratio is less than 100: 1, and M is as defined above, and is suitably a range from about 20: 1 to about 80: 1, preferably It is from 30: 1 to 70: 1. In preparing a sol with low S- 値 as defined above, the degree of the microsol can be influenced in several ways and controlled to the desired 値. The degree of the microsol can be affected by the salt content to adjust the preparation of the acid sol and the concentration in the first alkalizing step, because in this step, when the pH is about 5 and the minimum stability through the sol, the degree of the microsol affected. In the process, it takes a long time to make the degree of microsol. 11 This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm). Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 568884 A7 B7 5. DESCRIPTION OF THE INVENTION (?) Orientation. It is particularly appropriate to control the degree of microsol by adjusting the dry content and the content of SiO2 in the first alkalinization step, and to give lower S- 値 by a higher dry content. Keeping the Si02 content in the first alkalizing step in the range from 4.5 to 8% by weight, S- 値 can be controlled to the desired 値, for example: from 10 to 45%. In order to obtain a sol having a range of S-fluorene from 20 to 40%, the content of SiO2 in the first alkalizing step is appropriately maintained in a range from 5.0 to 7.5% by weight. The silica-based sol present in the alkalized sol in the first alkalinization step is then grown by particles to obtain particles having a lower specific surface area and higher stability. The particle growth method must be appropriately performed to provide silica-based particles having a specific surface area of at least 300 square meters per gram of Si02, preferably at least 400 square meters per gram of Si02, and most preferably It is at least 550 square meters / g Si02, and as high as about 1200 square meters / g Si02, suitably less than 1000 square meters / g Si02, especially as high as 950 square meters / G Si02. In a preferred embodiment of the present invention, the particle growth method is performed by providing particles having a specific surface area ranging from 550 to 725 m 2 / g SiO 2, preferably from 575 to 700 m 2 / G Si02. In another preferred embodiment of the present invention, it is performed to provide particles having a specific surface area ranging from 775 to 1200 square meters per gram of Si02, preferably from 800 to less than 1000 square meters per gram of Si. 〇2. The reduction in surface area can be obtained by storing at room temperature for a slightly longer time, one day or up to about two days and nights, or preferably by heat treatment. During the heat treatment, the time and temperature can be adjusted so that shorter times can be used at higher temperatures. It is of course even possible for a very short period of 12 $ paper size to apply Chinese National Standard (CNS) A4 specifications (210 X 297 mm) (Please read the precautions on the back before filling this page)

568884 A7 B7 V. Description of the invention (π) Use a relatively high temperature. From a practical point of view, it is more appropriate to use a lower temperature for a slightly longer time. The 'alkaliated sol in the heat treatment must be appropriately heated to a temperature of at least 30 ° C, suitably from 35 to 95 ° C, and preferably from 40 to 80 ° C. The heat treatment must be appropriately performed for at least 10 minutes, suitably from 15 to 600 minutes, and preferably from 20 to 240 minutes. After the particle growth step and optional cooling, the resulting silica-based sol is again alkalized, which is referred to herein as the second alkalization step, which further increases the pH. This second alkalizing step can be performed by adding conventional bases, for example: lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide and mixtures thereof, and / or a water-soluble silicate solution as defined above. Potassium and sodium water glass, especially sodium water glass having a SiO2 to M20 mole ratio as defined above, are suitable for use in the second alkalizing step. The SiO2 content of the water glass solution used in the second alkalizing step is suitably in a range from about 3 to about 35% by weight, and preferably in a range from about 5 to about 30% by weight Inside. The second alkalizing step is suitably performed to a pH of at least 8 · 0, suitably at least 10.0, preferably at least 10.5, and most preferably at least 10.6. The pH can be as high as about 11.5, suitably as high as 11.0. The second alkalization step is further suitably carried out until the final SiO2 to M20 molar ratio is in the range from about 10: 1 to 100: 1, M is as defined above, and suitably from 12: 1 To 40: 1, preferably from 15: 1 to 30: 1. In a preferred embodiment of the invention, the method also includes the concentration of a silica-based sol. Concentration can also be performed after the second alkalizing step. In addition, or in addition, after the first alkalization step, but at the size of 13 paper, the Chinese National Standard (CNS) A4 specification (210 X 297 mm) is applicable (please read the note 3 on the back before filling in this Page) Equipment I · 1 na · — I ϋ ϋ IIII · Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs, printed by the Consumer Cooperatives of the Ministry of Economic Affairs Printed by the Employees' Cooperative of the Intellectual Property Bureau of the Ministry of Economics, printed by 568884 A7 B7 V. Description of the invention (丨 丨) Before the growth or heat treatment step The resulting alkalized sol 'or sol after the particle growth or heat treatment step, but after the second alkalization step. Can be concentrated. Concentration can be performed in known ways, for example: by osmosis, evaporation and ultrafiltration. Concentration is suitably performed to produce a silica content of at least 10 weight. / 〇, preferably from 10 to 30% by weight, and more preferably from 12 to 25% by weight. Concentration is further appropriately performed so that the silica-based sol obtained in this method has a water-soluble sol having a specific surface area of at least 80 square meters per gram, that is, based on the weight of the water-soluble sol, preferably A water-soluble sol of at least 85 square meters per gram, more preferably a water-soluble sol of at least 90 square meters per gram, and most preferably a water-soluble sol of at least 95 square meters per gram. In a preferred embodiment of the present invention, the specific surface area of the water-soluble, silica-based sol obtained is suitably at least 115 square meters per gram of water-soluble sol, preferably at least 120 square meters. / G of water-soluble sol. Generally, the specific surface area of the obtained water-soluble sol may be as high as about 200 square meters / gram of water-soluble sol, suitably as high as 150 square meters / gram, and preferably as high as 130 square meters. / G of water-soluble sol. If desired, silica-based sols and particles can be added with compounds containing, for example, aluminum and / or boron. Suitable aluminum-containing compounds include aluminates such as: sodium aluminate and potassium aluminate, suitably sodium aluminate. The aluminum-containing compound is suitably used in the form of an aqueous solution. Suitable boron-containing compounds include boric acid; borates, such as: sodium and potassium borate, suitably sodium borate; tetraborates, such as: sodium and potassium tetraborate, suitably sodium tetraborate; and metaborate 'Like: sodium metaborate and potassium. The boron-containing compound is suitably in the form of an aqueous solution. 14 This paper is sized to the Chinese National Standard (CNS) A4 (210 X 297 public love) -----— — — — — — ^ -------- Order -------- Line · (Please read the precautions on the back before filling out this page) 568884 A7 B7 V. Description of Invention (p) to use. (Please read the notes on the back before filling this page.) When using an aluminum-containing compound in this method, add it to the sol appropriately before or after the second alkalization step, or when growing or heat-treating the particles. in. In addition, or in addition, the aluminum-containing compound may be added to the silicate solution to acidify before the particle growth or heat treatment step, to the acid sol, or to the alkalized sol obtained in the first alkalizing step. The aluminum-containing compound may be added in a mixture with the acid in the acidification step, and in a mixture with the base or the silicate solution in any one of the alkalinization steps. The appropriate addition amount of the aluminum-containing compound is such that the obtained sol has a Mohr ratio of Al203 to Si2O as defined above. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs When a boron-containing compound is used in this method, it is suitably added to the sol before or after the second alkalization step, and when the particles are grown or heat-treated. In addition, or in addition, the boron-containing compound may be added to the silicate solution to acidify, to the acid sol, or to the alkalized sol obtained in the first alkalizing step before the particle growth or heat treatment step. The boron-containing compound may be added in a mixture with the acid in the acidification step, and in a mixture with the base or the silicate solution in any one of the alkalization steps. A suitable addition amount of the boron-containing compound is such that the resulting sol has a molar ratio of B to Si2O as defined above. If both aluminum-containing and boron-containing compounds are used, their proper amount of addition is such that the resulting sol has a molar ratio of A1 to B as defined above. Before any modification of aluminum and / or boron, if the sol contains too high amounts of alkali metal or ammonium ions, it is preferred to remove at least a portion of these ions, for example: ion exchange to provide Silica-based sol with 15 paper sizes applicable to Chinese National Standard (CNS) A4 (210 X 297 mm) 568884 A7 B7 V. Description of the invention (j) = 530 m² / g Si02, and 39 m² M / g water soluble sol. Two additional silica sols, sol lb and sol lc, were produced with the following characteristics: Sol (lb) (reference): Si02 content = 7.3 weight. / 〇, Mo02 ratio of Si02 / Na20 = 63, ρΗ = 10 · 0, S- 値 = 26%, viscosity = 2.7 centipoise, specific surface area = 500 m 2 / g Si02, and 36.5 m 2 / g Water-soluble sol. Sol (lc) (reference): Si02 content = 5.4% by weight, Si02 / Na20 molar ratio = 35, PΗ = 9 · 8, S- 値 = 32%, viscosity = 1.6 centipoise, specific surface area = 690 square meters / G Si02, and 37 square meters / g water-soluble sol. Example 2 Six sols having silica as main particles according to the present invention were prepared from polysilicic acid, similar to polysilicic acid (II) produced by the same ion exchange process, and the content of SiO2 was 5.46 wt%. Under vigorous stirring, 1.46 kg of sodium water glass having a Si02 / Na20 ratio of 3.3 was added to 102.0 g of polysilicic acid, and the resulting solution had a Si02 / Na20 mole ratio of 54.0. This solution was heat-treated at 60 ° C for 2 hours and 20 minutes and cooled to 20 ° C, and then the product was now concentrated to a Si02 content of 15.6% by weight. The intermediate sol product is now divided into six separate samples, a to f. Samples a to c were further alkalized with NaOH, samples d to f were alkalized with water glass to achieve a sol with a Si02 / Na20 mole ratio between 21.5 and 34.0, and the silica content was approximately 15.0% by weight. Silica-based granules are obtained. 22 The paper size is applicable to Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) ϋ ϋ ϋ I meme I 一so, ... —a— tmt am— · ϋ ϋ · ϋ i Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 568884 A7 B7 V. Description of the invention (γ) The glue has the characteristics as described in Table 1: Table 1 Solmor Ratio [Si02 / Na20] pH S · 値 [%] Viscosity [centipoise] Specific surface area [square meter / meter [square meter / gram g Si〇2] Sol 2a 21.5 10.7 31 17 720 108.0 Sol 2b 28.0 10.3 30 29 710 106.5 Sol 2c 34.0 10.0 29 40 690 103.5 Sol 2d 21.5 10.7 31 20 680 102.0 Sol 2e 28.0 10.3 29 34 670 100.5 Sol 2f 33.0 10.0 29 38 680 102.0 Example 3 (Please read the precautions on the back before filling this page)

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs as in Example 2, polysilicic acid (Π) produced by the above-mentioned ion exchange method and alkalized with water glass to a Si02 / Na20 Mohr ratio of 54.0 at 60 ° C Under heat treatment for 1 hour. To 58 kg of this product was added 7.25 kg of diluted water glass having a Si02 / Na20 mole ratio of 3.3 and a silica content of 5.5% by weight. The obtained sol-sol 3 containing silica-based particles was concentrated to a silica content of 15.2% by weight, and had a Mo02 ratio of Si02 / Na20 = 24, pH = 10.7, S- 値 = 34, and viscosity = 9.0%. Poise, and specific surface area = 760 m 2 / g SiO 2, and 115.5 m 2 / g of water-soluble sol. Example 4 1000 g of polysilicic acid (Π) having a Si02 content of 5.5% by weight, with vigorous stirring, with a Si02 content of 27.1% by weight, and having a Si02 / Na20 mole ratio = 3.3 Mixing 14.5 grams of water glass, resulting in a product with a Si02 / Na20 molar ratio of 51 and a silica content of 23. This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm). Employees of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Consumer Cooperative 568884 A7 B7 V. Description of the Invention (7 丨) 5.8% by weight of SiO2, which was heat-treated at 60 ° C for 1.5 hours, and then concentrated to SiO2 with a silica content of 16.7% by weight. The obtained 283 grams of product was mixed with 33.0 grams of NaOH, resulting in a silica-based particle of sol-sol 4 having a content of Si02 = 15.2% by weight, a molar ratio of Si02 / Na20 = 21, PH = 10.6, S-値 = 32%, viscosity = 14.2 centipoise, and specific surface area = 720 m 2 / g SiO 2, and 109.4 m 2 / g of water-soluble sol. Example 5 The general procedure according to Example 3 was followed except that the heat treatment was performed for 1.25 hours and the concentration was carried out to a higher silica content. Two sols mainly composed of silica are prepared: sol 5a and sol 5b, and sol 5a has an Si02 content = 18 weight. / 〇, Mo02 ratio of Si02 / Na20 = 18, PH = 10.7, S- 値 = 36 ° /. , Viscosity = 18 centipoise, and specific surface area = 700 m 2 / g SiO 2, and 126 m 2 / g of water-soluble sol. Sol 5b has a content of Si02 = 20% by weight, a molar ratio of Si02 / Na20 = 18, ρΗ = 10 · 7, S · 値 = 37%, viscosity = 31 centipoise, and specific surface area = 700 m 2 / g Si02, And a water soluble sol of 140 m2 / g. Example 6 Drainage performance was evaluated by a Dynamic Drainage Analyser (DDA), available from Akrini, Sweden. 'When the stopper is removed and a vacuum is applied to the side where the raw material is present On the other side of the opposite pipeline, it measures the time to discharge a fixed volume of raw material through the net. 24 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) '(Please read the precautions on the back before filling this page)

568884 Printed by A7 B7, Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of Invention (&gt;) The raw materials used are based on a mixture of 60% bleached birch sulfate and 40% bleached pine sulfate 30% of honed calcium carbonate was added as the filling. The volume of the raw material was 80 ml, the concentration was 0.25%, and the pH was about 8.0. The conductivity of the raw materials was adjusted to 0.47 mS / cm by adding sodium sulfate. In tests, silica-based sols were used with cationic polymers. Raisamyl 142, which is a conventional medium-high cationized starch &apos; has a degree of substitution of 0.042 &apos; and its amount added to the raw material is 12 kg / metric ton &gt; calculated on the basis of the dry starch of the dry raw material system. The silica-based sols according to Examples 1 to 4 were tested in this example. In addition, sols 6a and 6b were also tested for comparison purposes. Sol 6a is a commercial silica with S- 値 = 45%, Si02 content = 15.0% by weight, Si〇2 / Na20 mole ratio = 40, viscosity = 3.0 centipoise, specific surface area = 500 square meters / g SiO2, and a water-soluble sol of 75 m2 / g. Sol 6b is another commercial silica sol with S- 値 = 36%, Si02 content = 10.0% by weight, Si02 / Na20 mole ratio = 10, viscosity = 2.5 centipoise, specific surface area = 880 square M / g SiO2, and 88 m2 / g water-soluble sol. The silica-based sol is added in an amount of 0.5 kg / metric ton, based on Si02 and based on a dry raw material system. Throughout the test, the raw materials were stirred at 15,000 revolutions per minute in a baffled bottle and chemically added as follows: i) adding cationic starch to the raw materials, continued stirring for 30 seconds, ii) adding Silica-based sol is mixed into the raw material, and then stirred for 15 seconds. Iii) The raw material is discharged, and the drainage time is automatically recorded. 25 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) ϋ 1 · 1 I · Β1 1 I I I I ϋ _

Public application

Amendment 91. 11. -1: Tongyou Case No. A4 C4 (the above columns are filled by the Bureau) 568884 Wumo Patent Specification, Invention, New Name Invention Creation / III. Applicant's Chinese and English Name Nationality Residence, Residence Name (Name) Nationality residence and residence (office) Silica-based sol and silica-based particles, their manufacturing methods and uses _

Silica-based Sols and Silica-based Particles, Their Production and Use 1. Pearson Michael 2. Dell Glen Margieris 3. Tokaz Marek Sweden 1. Sweden S-413 21 Gottborg, Fivikaga Tan 5C 2. Sweden S-449 33 Nottingi, Capriflex Gangen 9 3. Sweden S-442 39 Kongawu, Harkansgartan 4 AkzoNobel Netherlands Holland ML-6800 SB A Enhan, the name of the representative at PO Box 9300, Johnny Andrews, this paper ¥ The size is applicable to the Chinese national standard ^ (CNS) A4 (21 (^ 2 ^ 7 mm) gutter 568884 A7 B7 5. Description of the invention ((please first Read the notes on the back and fill in this page) The present invention relates generally to a silica-based sol suitable for papermaking. More specifically, the present invention relates to a silica-based sol and a Stone-cut granules, their manufacturing methods, and their uses in paper manufacturing. The method of the present invention provides silica-based granules with high drainage and retention performance, high stability, and high solid content, and A sol of silica-based particles. The background is 'contained in papermaking' An aqueous suspension of vitamin fiber and optional fillers and additives, called stock, is fed into a headbox, which injects the raw material into a net. Water is passed from the raw material through the net Drain, so that a wet web of paper is formed on the web, and the paper web is further dehydrated and dried in the dry part of the paper machine. Drainage and retained additives are customarily introduced into the raw materials to accelerate drainage, and Increasing the adsorption of finely divided particles on fibrous fibers, so that it maintains the fibers on the net. Silica-based particles combined with charged organic polymers are widely used as drainage and retention aids. The organic polymerization Objects are anionic and cationic polymers based on propionamidine, and cationic and amphoteric starches. Such additive systems are disclosed in U.S. Patent Nos. 4,388,150, 4,961,825, 4,980,025, 5,368,833, 5,603,805, 5,607,552 and 5,858,174; and international patent application W097 / 18351. These systems are among the most effective drainage and retention aids currently in use. Suitable for use in Silica-based particles for drainage and retention aids are generally supplied in the form of water-soluble colloidal suspensions. The water-soluble colloidal suspension is compatible with Chinese National Standard (CNS) A4 specifications (210 X 297 cm). ) 568884 A7 B7;. This V: "---Γ Dongi V. Description of the invention () 1 (Please read the precautions on the back before filling this page) The floating liquid is a so-called sol. Commercially used silica-based sols typically have a silica content of about 7 to 15% by weight and contain particles having a specific surface area of at least 300 square meters per gram. Silica-based particles with higher specific surface area are usually diluted to improve storage stability and avoid gel formation. It can superiorly provide silica-based sols and particles, which have further improved drainage and retention performance, and have better stability. It is also superior in being able to provide a method for preparing silica-based sols and particles, which have improved drainage, retention and stability properties. It is also better able to provide papermaking methods with improved drainage and / or retention. The invention • Threads • According to the present invention, silica-based sols and particles are provided, which are suitable for use as coagulants in water purification, and as drainage and retention aids for papermaking. The silica-based sols and particles according to the present invention show good stability over a prolonged period of time, especially high surface area stability and high stability to gels, and therefore they can have high specific surface areas and High silica concentration to prepare and transport. Silica-based sols and particles have improved capabilities to maintain a high specific surface area stored at high silica concentrations. When used with anionic, cationic and / or amphoteric organic polymers, the silica-based sols and particles according to the present invention further result in very good or improved drainage and retention. Therefore, the silica-based sols and particles according to the present invention can increase the speed of paper machines and use lower doses of additives to produce corresponding drainage and / or retention effects, thus leading to improved papermaking methods And economic benefits. Therefore, the present invention relates to the use of silica ____5_ This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 568884 A7 B7 one: five, the description of the invention (), ... one by one (please read the back of the first Note: Please fill in this page again.) The water-soluble sol containing mainly silica particles and silica-based particles 'also referred to as silica-based sols and their production' is further filed in the attached patent application. Defined in the scope. The present invention also relates to the use of silica-based sols and particles as drainage and retention aids in papermaking, which are preferably combined with the organic polymers described herein, as further described in the attached patent application Defined in the scope. As used herein, the term "drainage and retention aids" means one or more components (auxiliaries, reagents or additives) that, when added to a papermaking raw material, produce more than if the component were not added. For better drainage and / or retention. The present invention further relates to a method for producing paper from a water-soluble suspension containing cellulosic fibers and an optional filler, and for forming and draining the suspension on a web. Suspension and at least one charged organic polymer. The invention therefore relates to a method, as further defined in the scope of the attached patent application. The silica-based sol according to the present invention is a water-soluble sol, which includes anion particles mainly composed of silica, and particles mainly composed of silica (SiO2) or silicic acid. The particles are preferably colloidal, i.e. the size of the particles in the colloidal range. The silica-based particles present in the sol suitably have an average particle size of less than 10 nm, and preferably in a range from about 10 to about 2 nm. As is customary in the chemistry of colloidal particles mainly composed of silica, the 'particle size' means the average size of the main particles, which may be agglomerated or non-agglomerated particles. The specific surface area of the silica-based sol is suitably a water-soluble sol of at least 80 square meters per gram, that is, based on the weight of the water-soluble sol -____ 6___ This paper size applies to Chinese National Standards (CNS) A4 specification (210 X 297 mm) &quot; 568884 A7 r "_B7_, ..... C, V. Description of the invention (): There is a final molar ratio of Si02 to M20 as defined above. (Please read the precautions on the back before filling this page) According to the present invention, silica-based sols and particles, especially stable, silica-based sols and particles, can be used The sol prepared and produced exhibits good storage stability and can be stored for several months without any significant reduction in specific surface area and without gelling. The silica-based sol and particles according to the present invention are suitably Used as a flocculant, for example: in the production of pulp and paper, especially as a drainage and retention aid, and in the field of water purification, for the purification of different types of wastewater, and especially Purification of white water in the pulp and paper industry. Silica-based sols and particles can be used as flocculants, especially as drainage and retention aids, and can be selected from anionic, zwitterionic, nonionic and cationic polymers It is also known as a "main polymer" as a combination of organic polymers and mixtures thereof. This polymer is used as a flocculant and as a drainage and retention aid, and is well known in the art. The polymer can be Derived from natural or synthetic sources, and it may be linear, branched or crosslinked. Examples of the main polymers that are generally applicable include anionic, amphoteric and cationic starches; anionic, amphoteric and cationic guar gums ; And anionic, amphoteric and cationic polymers based on acrylamide, and cationic poly (diallyldimethylammonium chloride), cationic polyethyleneimine, cationic polyamines, cationic polyfluorene Amines and polymers based on vinylamine, melamine-formaldehyde and urea-formaldehyde resins, suitably silica-based sols, and at least Cation or two __16_ This paper size is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) 568884 A7 ___B7_; ^ ,. ~ -_ \ 1-5. Description of the invention ()…-: f sex polymerization The cationic polymer is preferably a cationic polymer. Cationic starch and cationic polyacrylamide are particularly good polymers, and they can be used alone, together or with other polymers, such as other cationic polymers or Anionic polypropylene amide. The molecular weight of the main polymer is suitably above 1,000,000, and preferably above 2,000,000. The upper limit is not important, it may be about 50,000,000 ', usually 30,000,000, and suitably About 25,000,000. However, the molecular weight of polymers derived from natural sources can be higher. When this silica-based sol and particles are used in combination with the above-mentioned main polymer, it is further preferred to use at least one low molecular weight (hereinafter referred to as LMW) cationic organic polymer, which is commonly referred to as being used in combination Anionic Garbage Collector (ATC). ATC is known in the art as a neutralizing and / or fixing agent for harmful anionic substances present in the raw materials, and it is used in combination with drainage and retention aids to provide further drainage and / or retention. LMW's cationic organic polymers can be derived from natural or synthetic sources, and are preferably LMW synthetic polymers. Suitable such organic polymers include LMW highly charged cationic organic polymers such as: polyamines, polyamidoamines, polyethyleneimines, based on diallyldimethylammonium chloride Homo- and copolymers, (meth) acrylamide and (meth) acrylic esters. The molecular weight of the LMW cationic organic polymer is relatively low relative to the molecular weight of the main polymer; it is suitably at least 1,000, and preferably at least 10,000. The upper limit of the molecular weight is usually about 700,000, suitably about 500,000, and usually about 200,000. Preferred combinations of polymers that can be shared with the silica-based sol of the present invention include: LMW cationic polymer and __17___ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read first (Notes on the back then fill out this page)

568884 A7 r:-_______ _B7_; _ 1 ί ^ * V. Description of the invention () ...... 'The combination of main polymers, for example: cationic starch and / or cationic polyacrylamide, anionic polyacrylamide Amine, and cationic starch and / or cationic polyacrylamide and combination with anionic polyacrylamide ## The components of the drainage and retention aid according to the present invention can be added to the raw materials in a conventional manner and in any order . When using silica-based particles and drainage and retention aids of organic polymers such as main polymers, it is preferred to add the polymer to the raw material before adding silica-based particles , Even if the reverse order of addition is available. It is further preferred to add the main polymer before the shearing stage, which can be selected from pumping, mixing, cleaning, etc., and to add silica-based particles after the shearing stage. When used, the LMW cationic organic polymer is preferably introduced into the raw material before introduction into the main polymer. In addition, the LMW cationic organic polymer and the main polymer may be introduced into the raw material at the same time, or introduced separately, or as a mixture, for example: as disclosed in US Patent No. 5,858,174, which is hereby incorporated herein by reference. The LMW cationic organic polymer and the main polymer are preferably introduced into the raw material before being introduced into silica-based particles. In a preferred embodiment of the present invention, the silica-based sol and particles are combined with at least one organic polymer as described above and at least one aluminum compound, and are used as drainage and retention aids. Brocade compounds can be used to further improve the drainage and / or retention performance of the raw material additives. The raw material additives contain silica-based particles. Appropriate Ming salts include alum, aluminate, aluminum chloride, aluminum nitrate, and polyaluminum compounds. For example: polychloride __18______ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)- ------------ Install --- (Please read the precautions on the back before filling this page) Order: Line 568884 A7 _B7 _ :: _ V. Description of the invention () ..... (Please read the notes on the back before filling out this page) Aluminum, polyaluminum sulfate, polyaluminum compounds containing both chloride and sulfate, polyaluminosilicate-sulfate, and mixtures thereof. Polyaluminum compounds may also contain other anions, such as anions derived from phosphoric acid, organic acids, such as citric acid and oxalic acid. Preferred aluminum salts include sodium aluminate, alum and polyaluminum compounds. The aluminum compound can be added before or after the silica-based particles are added. In addition, or in addition, the aluminum compound may be added at the same time as the silica-based sol at the same point, or separately or in a mixture with it, for example: as disclosed in US Patent No. 5,846,384 This is here for reference. In many cases' it is usually appropriate early in the process, for example, to add aluminum compounds to the raw material before other additives, and the components of the drainage and retention aids according to the present invention can be added to the raw material to dehydrate, Its weight can vary within wide limits, especially depending on the type and number of components, the type of equipment, the content of the filling, the type of filling, the point of addition, etc. Generally, the amount of component added is better drainage and / or retention than that obtained without the component. Silica-based sols and granules are usually added in an amount of at least 0.001% by weight, often at least 0.005% by weight, based on Si02 and based on dry raw material substances, g: cellulose fiber and optional It is usually charged at an upper limit of 1.0%, and suitably 0.5% by weight. The main polymer thorn is usually added in an amount of at least 0.001%, often at least 0.005% by weight, based on the raw material substance, and the upper limit is usually 3%, and suitably 1.5% by weight. When LMW cationic organic polymers are used in this method, the amount that can be added is at least 0.05% by weight, based on the dried material of the raw material to be dehydrated. 19 This paper size applies to Chinese National Standard (CNS) A4 specifications 210 X 297 mm) 568884 A7, '____B7_______ V. Description of the invention () · U-based quality. A suitable portion range is from 0.07% to 0.5%, and a preferred range is from 0.1 to 0.35%. When an aluminum compound is used in the method, the total amount to be introduced into the raw material to be dehydrated depends on the kind of the aluminum compound used and other effects desired therefrom. For example, it is well known in the art to use aluminum compounds as rosin-based sizing agents. The total amount added is usually at least 0.05%, calculated on Al203 and based on the dry feedstock material. A suitable portion range is from 0.1 to 3.0%, and a preferred range is from 0.5 to 2.0%. Other additives conventionally used in papermaking can of course be used in combination with the additives according to the invention, for example: dry strengthening agents, wet strengthening agents, optical luminescent agents, dyes, sizing agents, such as rosin-based Sizing agents and sizing agents that are reactive with cellulose, such as alkyl and alkenyl ketene dimers and ketene polymers, alkyl and alkenyl succinic anhydride, and the like. Cellulose suspensions or raw materials can also contain conventional types of mineral fillers such as kaolin, Chinese clay, titanium dioxide, gypsum, talc, and natural and synthetic calcium carbonate, such as chalk, powdered marble, and precipitated Calcium carbonate. The method of the invention can be used to produce paper. The term "paper" as used herein, of course, includes not only paper and its products, but also other cellulosic fiber sheets or net products, such as, for example, cardboard and paperboard, and their products. This method can be used to produce paper from different types of cellulose-containing suspensions, and the suspension must suitably contain at least 25% by weight, and preferably at least 50% by weight of such fibers, on a dry matter basis. The suspension can be based on the fibers of chemical pulp, for example: sulfate, sulphur ___ ._20 ____ This paper size applies to China National Standard (CNS) A4 (21〇χ 297 mm) (Please read the note on the back first Please fill in this page for matters): Binding ···· Line · 568884 B7 V. Description of the invention () I ..... (Please read the notes on the back before filling this page) Acid salt and other organic dissolved pulp; Mechanical pulp, for example: thermomechanical, pulp, chemical-thermomechanical pulp, refined pulp; and ground wood paper, from hardwood and softwood, and also based on recycled fiber, stomach_ choose pulp from ink removal , And mixtures thereof. The pH of the suspension and raw materials can range from about 3 to about 10. The pH is suitably 3.5 or more, and preferably in the range of 4 to 9. The invention is further illustrated in the following examples, however, it is not intended to limit the same. Part as well. / 〇 corresponds to the weight portion and 4% by weight, respectively, unless stated otherwise. Example 1 A standard silica sol was prepared as follows:-line · 762.7 grams of sodium water glass with a mole ratio of SiO2 to Na2O of 3.3 'and a SiO2 content of 27.1%' diluted with water to 3000 grams, A silicate solution (I) was produced with a SiO 2 content of 6.9% by weight. 2800 grams of this silicate or water glass solution was passed through a column filled with strong cation exchange resin saturated with hydrogen ions. 2450 g of ion-exchanged water glass or polyoxalic acid (Π) had a SiO 2 content of 6.5% by weight and a pH of 2.4 and were collected from an ion exchanger. 1988 grams of polysilicic acid (II) was fed into the reactor and diluted with 12.3 grams of water. Then 173.9 g of a 6.9% silicate solution (I) was added under vigorous stirring, and the resulting solution was then heated at 85 ° C for 60 minutes, and then cooled to 20 ° C. The obtained silica sol (la) has the following characteristics: Sol (1 &amp;) (reference): 8 丨 02 content = 7.3% by weight, 8 丨 02 / _20 mole ratio = 40, 1 ^ = 10.2, 8- 値= 29%, viscosity = 2.2 centipoise, specific surface area, __21____ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 568884 A7 B7 V. Description of the invention ()… One pair of different silica The drainage time of the main sol is shown in Table 2:, Table 2 Main sol_dehydration time [second] _ Luojiao la (reference) 12.0 11.1 12.0 9.7 9.5 9.4 12.0 9.8 (Please read the precautions on the back before filling (This page) Sol lb (Reference) Sol le (: J test) Sol 2d Sol 3 Sol 4 Sol 6a (Reference) Grain 6 b (Reference) Example 7 Use the general procedure of Example 6 to evaluate the performance of drainage, except that The raw material had a concentration of 0.3% and a pH of about 8.5. Retention efficiency is evaluated by a suspension meter, and the turbidity of the filtrate and white water obtained by discharging the raw materials is measured. A silica-based sol according to the present invention and according to Example 5 was tested for comparison with the sol. Table 3 shows the drainage time obtained for silica-based particles at different doses (kg / metric ton), calculated on Si02 and based on the dry feedstock system. Only cationic starch was added (12 kg / metric ton based on the dry raw material system), resulting in a drainage time of 15.8 seconds. … ’___ Table 3_ Silica-based sol drainage time (seconds) / turbidity (Nτυ), at 0.5 kg / ton 1.0 kg / ton! 5 kg / ton 2.0 kg: Sol 6b (reference) Sol 5a Sol 5b 11.1 /. "8/597 9/58 9.0 /-7.1 / 52 6.3 / 50 5.2 / 52 · 8 / 6〇8.9 /-6.9 / -6.3 /-5 · 7Λ *? / 53 6.0 /. 26 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm)

Claims (1)

568884 Β8 /.¾ .. C8 D8 &gt; Scope of patent application H1 ^ (Please read the precautions on the back before writing this page) 1. A method for manufacturing a water-soluble sol containing silica-based particles, It includes: (a) acidifying a water-soluble silicate solution to a pH of 1 to 4 to form an acid sol; (b) alkalizing the acid sol having a SiO 2 content in the range of 4.5 to 8% by weight to a pH of at least 7; (c) growing the particles of the alkalized sol for at least 10 minutes; (d) alkalizing the resulting sol to a pH of at least 10.0; and (e) optionally concentrating the obtained according to (b), (c) or (d) To provide a water-soluble sol containing silica-based particles and having a specific surface area of at least 90 square meters per gram of water-soluble sol. 2. A method of manufacturing a water-soluble sol containing silica-based particles, comprising: (a) acidifying a water-soluble silicate solution to a pH of 1 to 4 to form an acid sol; (b) alkalizing The acid sol having a Si02 content in the range of 4.5 to 8% by weight (c) heat-treating the alkalized sol at a temperature of at least 30 ° C; (d) alkalizing the heat-treated sol to a pH of at least 10.0; and (e) The sol 'obtained according to (b), (c) or (d) can be optionally concentrated to provide a water-soluble sol containing sand-based particles and having a specific surface area of at least 90 square meters per gram of water-soluble sol. 3. The method according to item 1 or 2 of the scope of patent application, characterized in that it includes (e) concentrating the sol obtained according to (c) or (d) to provide a specific surface area. The paper size is applicable to Chinese National Standard (CNS) A4. Specifications (210x297 mm) 568884 A8 B8 C8 D8 6. Apply for a patent with a sol of at least 95 square meters per gram of water-soluble sol. (Please read the notes on the back before writing this page) 4. The method according to item 丨 or 2 of the scope of patent application, characterized in that the alkalization according to (b) and (d) is through water-soluble silicate Solution. 5. The method according to item 1 or 2 of the scope of patent application, characterized in that the particle growth and heat treatment according to (c) are performed at a temperature ranging from 35 to 95 ° C. 6. The method according to item 1 or 2 of the patent application scope, characterized in that the particle growth and heat treatment according to (c) are performed for 20 to 240 minutes. 7. The method according to item 1 or 2 of the scope of patent application, characterized in that the molar ratio of Si02 to M20 (where M is an alkali metal ion or ammonium) according to (d) is 15: 1 to 30: Sols in the range of 1 and a pH of at least 10.6 ^. 8. The method according to item 1 or 2 of the scope of patent application, characterized in that it further comprises adding an aluminum-containing compound and / or a boron-containing compound. 9. The method according to item 1 or 2 of the scope of patent application, characterized in that the obtained silica-based particles have a specific surface area of at least 550 square meters per gram of Si02. 10. A water-soluble sol containing silica-based particles, which can be obtained by a method according to any one of claims 1 to 9 of the scope of patent application. 11. A water-soluble sol containing silica-based particles, characterized in that it has a specific surface area of at least 115 square meters / g of water-soluble sol, and the silica-based particles have at least 550 square meters / Specific surface area of gram and less than 1000 square meters / gram Si02. 12. —A kind of water-soluble sol containing silica-based particles, characterized by _____2___ This paper size applies Chinese National Standard (CNS) A4 (210 X 297 mm) &quot; 568884 A8B8C8D8 (Please read the notes on the back before writing this page). It has a specific surface area of at least Π5 m2 / g water-soluble sol and S- 値 in the range of 10 to 45%. 13. The water-soluble sol according to item u or 12 of the scope of the patent application, characterized in that it has a molar ratio of SiO2 to M20 (where μ is an alkali metal ion or ammonium) in the range of 15: 1 to 40: 1. 14. The water-soluble sol according to item 12 of the application, characterized in that the silica-based particles have a specific surface area of at least 550 m 2 / g Si02. 15. The water-soluble sol according to claim 11 or 12, characterized in that it has S- 値 in the range of 25 to 35%. 16. The water-soluble sol according to claim 11 or 12, characterized in that it has a silica content of at least 10% by weight. Line 17. 17. A water-soluble solution containing silica-based particles prepared according to any of claims 10 to 16 or by a method according to any of claims 1 to 9 The use of sexual sol, which is used as a drainage and retention aid in paper production. 18. —A method for making paper from a water-soluble suspension containing cellulose fibers and an optional filler, which comprises adding silica-based particles and at least one charged organic polymer to the suspension Forming the suspension on a wire and draining the water, the method is characterized in that the silica-based particles are obtained by a method according to any one of claims 1 to 9 of the scope of patent application, or Exist in a water-soluble sol according to any one of claims 10 to 16 of the scope of patent application. 19. A method for producing paper, comprising: This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 568884 A8B8C8D8 6. Scope of patent application (a) Provide cellulose fiber and optional Filled water-soluble suspension; (Please read the notes on the back before writing this page) (b) Provide a water-soluble sol containing silica-based particles, the sol has a water solubility of at least 90 square meters / g The specific surface area of the sol, and the silica-based particles have a specific surface area of less than 1,000 square meters per gram of Si02; 0) providing at least one charged organic polymer; (d) adding the charged Organic polymer and silica-based particles into the suspension; (e) forming the resulting suspension on a wire and draining. 20. —A method for producing paper, comprising: (a) providing a water-soluble suspension containing cellulose fibers and an optional filler; thread '(b) providing water-solubility including silica-based particles A sol having a specific surface area of at least 90 square meters per gram of a water-soluble sol and S- 値 in a range of 10 to 45%; (c) providing at least one charged organic polymer; (d) adding the tape Charged organic polymers and silica-based particles are added to the suspension; (e) The resulting suspension is shaped on a wire and drained. 21. The method according to claim 19 or 20, characterized in that the sol has a specific surface area ranging from 95 to 150 square meters per gram of water-soluble sol. 22. The method according to item 19 or 20 of the scope of patent application, which is characterized by 4 applicable Chinese National Standard (CNS) A4 specification (210 X 297 mm) &quot; &quot; 568884 A8 C8 D8 Granite-based particles have a specific surface area of at least 550 square meters / gram Si02. 23. A method according to item 19 or 20 of the scope of the patent application, characterized in that the charged organic polymer is a cationic starch or a cationic polypropylene amidine. 24. The method according to claim 19 or 20, characterized in that the water-soluble sol is diluted to a silica content of about 0.05 to 5% by weight before adding silica-based particles to the suspension. 25. The method according to item 19 or 20 of the patent application scope, characterized in that the proportion of silica-based particles added to the suspension ranges from 0.005 to 0.5% by weight, which is calculated based on SiO2 and is based on dry fibers. Based on plain fibers and optional fillings. (Please read the notes on the back before transcribing this page)