CN1912242B - Paper making method - Google Patents

Abstract

A process for the production of paper which includes the steps of: (a) providing an aqueous suspension containing cellulosic fibers, and optional fillers; (b) an aqueous sol containing silica-based particle having a specific surface area of at least 90 m<2>/g aqueous sol, and the particles contained in the sol having a specific surface area less than 1000 m<2>/g SiO2; (c) at least one charged organic polymer; (d) adding the charged organic polymer and the aqueous sol containing silica-based particle to the suspension: and (e) carrying out formation of the obtained suspension on a mesh and drainage thereof.

Description

Produce the method for paper

The application is denomination of invention the dividing an application for the Chinese patent application 00807147.0 of " silica-based sols " of on April 28th, 2000 application.

The present invention relates generally to a kind of method of producing paper.

Background

In field of papermaking, the water slurry that comprises dispensable filler of cellulose fiber peacekeeping and additive that will be called raw material is fed to flow box, then raw material is ejected on the forming web.Water through this forming web, forms wet web on the net at this by the raw material discharging like this, then with the further dehydration and dry in the dryer section of paper machine of this paper web.Usually with draining with keep auxiliary agent and add in the raw material to help draining and the absorption of increase fine grained on cellulose fibre, they and fiber are stayed on the net like this.

Silica base particle and charged organic polymer such as anion and cation acrylamide based polyalcohol and CATION and amphoteric starch combine and are widely used as draining and keep auxiliary agent.These additive systems are disclosed in United States Patent (USP) 4388150,4961825,4980025,5368833,5603805,5607552 and 5858174 and International Patent Application WO 97/18351.These systems are the most effective drainings of using at present and keep auxiliary agent.

The suitable silica base particle of doing draining and keeping auxiliary agent is usually with aqueous colloidal dispersion, and the form of so-called colloidal sol is supplied with.The silica-based sols of commercial use has the silica content of about 7-15% weight usually and comprises specific area and is at least 300 meters ²The particle of/gram.The colloidal sol of silica base particle with high specific surface area is too rare usually, can not improve storage stability and avoid forming gel.

Can provide and have further improved draining and retention performance and even better the silica-based sols and the particle of stability are favourable.Can provide that a kind of preparation has improved draining, silica-based sols and the particle kept with performance for stability also are favourable.It also is favourable that a kind of paper technology that has improved draining and/or keep effect can be provided.

The present invention

According to the present invention, provide to be adapted at being used as flocculant in the desalt and in papermaking, to be used as draining and to keep the silica-based sols and the particle of auxiliary agent.Have good long term stability, obviously high surface area stability and high gelling stability according to silica-based sols of the present invention and particle, thus they can high-specific surface area and high silica concentration be prepared and transport.Silica-based sols and particle more can keep high-specific surface area when storing under the high silica concentration.Also have extraordinary or improved draining and keep effect when being used in combination according to silica-based sols of the present invention and particle with anion, CATION and/or both sexes organic polymer.Like this, can increase the speed of paper machine and use than the additive of low dosage obtaining corresponding draining and/or to keep effect according to silica-based sols of the present invention and particle, thereby improve paper technology and economic benefit.Therefore the present invention relates to silica base particle and is also referred to as the hydrosol that comprises silica base particle and the production method thereof of silica-based sols in this article, and this further is defined in appending claims.

The invention still further relates to silica-based sols and particle, preferred combination organic polymer described herein is as draining and keep the application of auxiliary agent in papermaking, and this further is defined in appending claims.Term used herein " draining and keep auxiliary agent " is meant the component (auxiliary agent, reagent or additive) that obtains when not adding these components better draining when one or more are in adding paper making raw material and/or keep effect.The invention further relates to a kind of method of producing paper, comprise, in this suspension, add silica base particle and at least a charged organic polymer, moulding on the net of this suspension and draining by the water slurry that comprises the not essential filler of cellulose fiber peacekeeping.Therefore the present invention relates to a kind of method that further is defined in appended claims.

According to silica-based sols of the present invention is to comprise anionic silica-based particles, that is, and and based on silica (SiO ₂) or the hydrosol of the particle of silicic acid.This particle is preferably colloidal state,, is in the colloidal state particle size range that is.The average grain diameter that is present in the silica base particle in the colloidal sol is lower than about 10 nanometers and is preferably about 10-2 nanometer.As the general knowledge in the silica-based colloidal particles chemistry, particle diameter is meant the average-size of the primary particle that can assemble or not assemble.

The specific area of silica-based sols is at least 80 meters suitably ²/ gram the hydrosol, that is, based on the weight of the hydrosol, preferably at least 85 meters ²/ gram the hydrosol, more preferably at least 90 meters ²/ gram the hydrosol, most preferably at least 95 meters ²/ gram the hydrosol.In a preferred embodiment of the invention, the specific area of aqueous silica based sols is at least 115 meters suitably ²/ gram the hydrosol, preferably at least 120 meters ²/ gram the hydrosol.In general, the specific area of the hydrosol can be the highest about 200 meters ²/ gram the hydrosol, the highest suitably 150 meters ²/ gram the hydrosol, preferably the highest 130 meters ²/ gram the hydrosol.

The specific area of silica base particle is at least 300 meters suitably ²/ gram SiO ₂, that is, and based on SiO ₂Weight, preferably at least 400 meters ²/ gram SiO ₂, most preferably at least 550 meters ²/ gram SiO ₂In general, the specific area of particle can be the highest about 1200 meters ²/ gram SiO ₂, be lower than 1000 meters suitably ²/ gram SiO ₂, preferably the highest 950 meters ²/ gram SiO ₂In a preferred embodiment of the invention, the specific area of particle is at 550-725 rice ²/ gram SiO ₂, preferred 575-700 rice ²/ gram SiO ₂Scope in.In another preferred embodiment of the present invention, the specific area of particle is at 775-1200 rice ²/ gram SiO ₂, preferred 800 to being lower than 1000 meters ²/ gram SiO ₂Scope in.

Suitably removing or regulating any compound that may upset titration that is present in the sample, after aluminium and boron substance, specific area can a kind ofly for example be described in Sears's Analytical chemistry 28(1956): 12, the known way of 1981-1983 and United States Patent (USP) 5176891 is by measuring with the NaOH titration.If square metre numerical table with every gram hydrosol shows that specific area is represented the specific area that every gram aqueous silica based sols is had.If square metre numerical table with every gram silica shows that specific area represents to be present in the average specific surface area of the silica base particle in the colloidal sol.

Silica-based sols has 10-45% usually, suitably 20-40%, preferably the S value in the 25-35% scope.The S value can be according to Iler ﹠amp; Dalton exists The physical chemistry magazine60 (1956), measure described in the 955-957 and calculate.The gathering of degree that the S value representation is assembled or microgel forms and lower S value representation higher degree.

The SiO of silica-based sols ₂With M ₂The mol ratio of O was at least 10: 1 usually, suitably at least 12: 1, preferably at least 15: 1, wherein M be alkali metal ion (as, Li, Na, K) and/or ammonium.SiO ₂With M ₂The mol ratio of O generally can be the highest 100: 1, the highest 40: 1 suitably, preferably the highest 30: 1.Therefore preferable range is 10: 1-100: 1, especially 15: 1-30: 1.The pH value of silica-based sols is at least 8.0 usually, is at least 10.0 suitably, and preferably at least 10.5, more preferably at least 10.6.The pH value is can be the highest about 11.5, is up to 11.0 suitably.

Silica-based sols should have the silica content of at least 3% weight suitably, but more suitably is, silica content is in 10-30% weight, in the scope of preferred 12-25% weight.In order to simplify transportation and to reduce cost of transportation, the general preferred silica-based sols that transports high concentration, certainly, can and usually preferably before using, silica-based sols and particle be diluted and be mixed to lower basically silica content, the silica content in the 0.05-5% weight range for example can improve and the mixing of furnish component like this.The viscosity of silica-based sols can be for example changes according to the silica content of colloidal sol.Usually, this viscosity is at least 5 centipoises, is generally the 5-40 centipoise, suitably 6-30 centipoise, preferably 7-25 centipoise.Preferably the viscosity that is at least the sol assay of 10% weight according to silica content can for example use Brookfield LVDV II+ viscosimeter to measure by known technology.

Silica-based sols of the present invention is preferably stable.Term used herein " stable silica-based sols " be meant under 20 ℃ dark and do not store under the agitated conditions or the viscosity increase is lower than 100 centipoises aging 1 month time the silica-based sols.If colloidal sol stands above-mentioned condition, viscosity increases (if any) and is preferably lower than 50 centipoises, preferably is lower than 30 centipoises.

In a preferred embodiment of the invention, silica-based sols does not have aluminium basically,, does not have to add the modifier that contains aluminium that is.In another preferred embodiment of the present invention, silica-based sols does not have boron basically,, does not add the modifier of boracic that is.But a spot of these elements can be present in the initiation material that is used for preparing silica-based sols and particle.In another preferred embodiment of the present invention, silica-based sols uses the various elements that are present in water and/or the silica base particle, carries out modification as aluminium and/or boron.If use aluminium, the Al of this colloidal sol ₂O ₃With SiO ₂Mol ratio 1: 4-1: 1500, suitably 1: 8-1: 1000, preferred 1: 15-1: in 500 the scope.If use boron, the B of this colloidal sol and SiO ₂Mol ratio 1: 4-1: 1500, suitably 1: 8-1: 1000, preferred 1: 15-1: in 500 the scope.If use aluminium and boron, the mol ratio of Al and B can be 100: 1-1: 100, suitably 50: 1-1: in 50 the scope.

Can be according to silica-based sols of the present invention and particle by the aqueous silicate solution such as the alkaline water glass of routine, as potassium or sodium silicate, preferred sodium silicate begins preparation.In silicate solutions or waterglass, SiO ₂With M ₂The mol ratio of O is suitably 1.5: 1-4.5: 1, preferred 2.5: 1-3.9: in 1 the scope, wherein M is alkali metal such as sodium, potassium, ammonium or its mixture.Preferably use a kind of silicate solutions or waterglass of dilution, its SiO ₂Content can be about 3-12% weight, preferably about 5-10% weight.The pH value is generally about 13 or be higher than 13 silicate solutions or waterglass and be acidified to the pH value and be about 1-4.Acidifying can be in a known way by adding inorganic acid such as sulfuric acid, hydrochloric acid and phosphoric acid, or optionally use the chemicals of other suitable waterglass acidifying such as ammonium sulfate and carbon dioxide to carry out.If adding inorganic acid, acidifying preferably carry out in two steps, the first step is carried out certain slaking to the about 8-9 of pH value at this, that is, germination further is acidified to the about 1-4 of pH value then.But preferably, acidifying utilizes a kind of more stable acid cationite of product that also causes inter alia to carry out.Acidifying preferably utilizes strong-acid cation-exchange resin, and for example sulfonic resin carries out.Preferably, acidifying proceeds to the pH value for about 2-4, most preferably from about 2.2-3.0.Products therefrom (acid-sol or poly-silicic acid) comprises and has high-specific surface area, generally above 1000 meters ²/ gram SiO ₂And be generally about 1300-1500 rice ²/ gram SiO ₂Silica base particle.

Acid-sol alkalizes subsequently, is called first alkalinization step in this article.First alkalization can be by adding conventional alkali, and for example lithium hydroxide, NaOH, potassium hydroxide, ammonium hydroxide and composition thereof and/or definition aqueous silicate solution as above carry out.SiO ₂With M ₂Mol ratio definition potassium and sodium silicate, the especially sodium silicate as above of O is applicable to this alkalinization step.The SiO that is used for the water glass solution of first alkalization ₂Content is suitably in about 3-35% weight, in the scope of preferred 5-30% weight.First alkalization proceeds to the pH value usually and is at least 6, is at least 7 suitably, preferably is at least 7.5, and the pH value is up to 10.5 usually, is up to 10.0 suitably.First alkalization further proceeds to SiO suitably ₂With M ₂The final mol ratio of O is lower than 100: 1, and suitably about 20: 1-80: 1, preferred 30: 1-70: in 1 the scope, wherein the M definition as above.In preparation when having the colloidal sol of low S value as mentioned above, degree of microgel is can several modes influenced and be controlled to desirable value.Degree of microgel by be adjusted in preparation during acid-sol and the concentration in first alkalinization step be subjected to the influence of salt content because in this step, degree of microgel is influenced when qualitative when passing through minimum steady under the pH value of this colloidal sol about 5.Especially suitably by in first alkalinization step, regulating dried content (SiO ₂Content) control degree of microgel, higher so dried content obtains lower S value.By in first alkalinization step with SiO ₂Content remains in the scope of 4.5-8% weight, and the S value can be controlled to for example desirable value of 10-45%.In order to obtain the colloidal sol of S value in the 20-40% scope, the SiO in first alkalinization step ₂Content remains in the scope of 5.0-7.5% weight suitably.

The silica base particle that is present in the alkalization colloidal sol that obtains in first alkalinization step carries out germination subsequently, obtains having the particle than low specific surface area and higher stability like this.The germination process should be carried out suitably, obtains specific area and is at least 300 meters ²/ gram SiO ₂, preferably at least 400 meters ²/ gram SiO ₂, most preferably at least 550 meters ²/ gram SiO ₂, and the highest about 1200 meters ²/ gram SiO ₂, be lower than 1000 meters suitably ²/ gram SiO ₂, especially the highest 950 meters ²/ gram SiO ₂Silica base particle.In a preferred embodiment of the invention, it is 550-725 rice that germination process is carried out to obtain specific area ²/ gram SiO ₂, preferred 575-700 rice ²/ gram SiO ₂Particle.In another preferred embodiment of the present invention, it is 775-1200 rice that the germination process is carried out to obtain specific area ²/ gram SiO ₂, preferred 800-1000 rice ²/ gram SiO ₂Particle.The reduction of surface area can by at room temperature store a little long time (1 day to the highest about 2 day and night) or preferably realize by heat treatment.When heat treatment, can regulate time and temperature, can under higher temperature, use the short period like this.Even certainly in the very short time, use higher temperature, consider from reality, be more suitable in a little long time, using lower temperature.When heat treatment, alkalization colloidal sol should be heated at least 30 ℃ suitably, and 35-95 ℃ suitably, preferred 40-80 ℃ temperature.Heat treatment should be carried out 10 minutes suitably at least, and 15-600 minute suitably, preferred 20-240 minute.

After germination process and dispensable cooling, the gained silica-based sols alkalizes at this, is referred to herein as second alkalinization step, with further increase pH value.Second alkalization can be by adding conventional alkali, and for example lithium hydroxide, NaOH, potassium hydroxide, ammonium hydroxide and composition thereof and/or definition aqueous silicate solution as above carry out.SiO ₂With M ₂Mol ratio definition potassium and sodium silicate, the especially sodium silicate as above of O is applicable to second alkalinization step.The SiO that is used for the water glass solution of second alkalization ₂Content is suitably in about 3-35% weight, in the scope of preferred 5-30% weight.Second alkalization proceeds to the pH value usually and is at least 8.0, is at least 10.0 suitably, preferably is at least 10.5, and most preferably at least 10.6.The pH value can be up to 11.5, is up to 11.0 suitably.Second alkalization further proceeds to SiO suitably ₂With M ₂The final mol ratio of O is about 10: 1-100: 1, suitably 12: 1-40: 1, preferred 15: 1-30: in 1 the scope, wherein the M definition as above.

In a preferred embodiment of the invention, this process also comprises concentrating of silica-based sols.Concentrate and after second alkalization, to carry out.In addition, after first alkalization but gained germination or heat treatment step after alkalizes colloidal sol or after germination or heat treatment step but can concentrate at second the gained colloidal sol before alkalizing.Concentrate and to pass through known way, for example undertaken by osmosis, evaporation or ultrafiltration.Concentrate and carry out suitably to obtain being at least 10% weight, preferred 10-30% weight, the more preferably silica content of 12-25% weight.Concentrate and further to make the specific area of the silica-based sols that in this process, obtains be at least 80 meters suitably based on hydrosol weight ²/ gram the hydrosol, preferably at least 85 meters ²/ gram the hydrosol, more preferably at least 90 meters ²/ gram the hydrosol, most preferably at least 95 meters ²/ gram the hydrosol.In a preferred embodiment of the invention, the specific area of the suitable silica-based sols of gained is at least 115 meters suitably ²/ gram the hydrosol, preferably at least 120 meters ²/ gram the hydrosol.In general, the specific area of the gained hydrosol can be up to about 200 meters ²/ gram the hydrosol is up to 150 meters suitably ²/ gram the hydrosol preferably is up to 130 meters ²/ gram the hydrosol.

If desired, silica-based sols and particle can carry out modification by the compound that adding comprises aluminium for example and/or boron.Aluminum contained compound comprises aluminate such as sodium aluminate and potassium aluminate suitably, is sodium aluminate suitably.Aluminum contained compound uses with the form of the aqueous solution suitably.Suitable boron-containing compound comprises boric acid, borate such as Boratex and potassium borate, is Boratex suitably, and tetraborate such as sodium tetraborate and dipotassium tetraborate are sodium tetraborate and metaborate such as kodalk and potassium metaborate suitably.Boron-containing compound uses with the form of the aqueous solution suitably.

If in this technology, use aluminum contained compound, be preferably in before or after second alkalinization step its is added and carry out in germination or the heat treated colloidal sol.In addition, aluminum contained compound can add before germination or heat treatment step by in the silicate solutions of acidifying, in the acid-sol or in the alkalization colloidal sol that obtains in first alkalinization step.Aluminum contained compound can be in acidification step mixes with acid and adds or mix adding with alkali or silicate solutions in any alkalinization step.The suitable addition of aluminum contained compound makes gained colloidal sol have definition Al as above ₂O ₃With SiO ₂Mol ratio.

If in this technology, use boron-containing compound, be preferably in before or after second alkalinization step its is added and carry out in germination or the heat treated colloidal sol.In addition, boron-containing compound can add before germination or heat treatment step and treats by in the silicate solutions of acidifying, in the acid-sol or in the alkalization colloidal sol that obtains in first alkalinization step.Boron-containing compound can be in acidification step mixes with acid and adds or mix adding with alkali or silicate solutions in any alkalinization step.The suitable addition of boron-containing compound makes gained colloidal sol have definition B and SiO as above ₂Mol ratio.If use aluminum contained compound and boron-containing compound, their suitable addition makes gained colloidal sol have definition Al as above and the mol ratio of B.

If colloidal sol comprised the alkali metal ion or the ammonium ion of too many amount before any aluminium and/or boron modification, preference obtains SiO as remove these ions of at least a portion by ion-exchange ₂With M ₂The silica-based sols of final mol ratio in above-mentioned ideal range of O.

According to method of the present invention, can prepare silica-based sols and particle with above-mentioned characteristic, especially stable silica-based sols and particle, and gained colloidal sol has excellent storage stability and can store some months, and specific area is without any descending significantly and not having gelling.

Be fit to for example in the manufacturing of paper pulp and paper, be used as flocculant according to silica-based sols of the present invention and particle, especially be used as draining and keep auxiliary agent, and be used for the desalt field, be used for the different types of waste water of purifying and be used for purifying especially from the white liquid of paper pulp and paper industry.Silica-based sols and particle can combine with the organic polymer that is also referred to as " host polymer " in this article that is selected from anion, both sexes, nonionic and cationic polymer and composition thereof as flocculant, especially are used as draining and keep auxiliary agent.These polymer are well known in the art as flocculant with as draining and the purposes of keeping auxiliary agent.Polymer can be from natural or synthetic source, and they can be straight chain or side chain or crosslinked.The example of general suitable host polymer comprises that anion, both sexes and cationic starch, anion, both sexes and cation guar gum and anion, both sexes and cation acrylamide based polyalcohol and CATION poly-(diallyldimethylammonium chloride), CATION are polyethylene imine based, cationic polyamine, polyamidoamines amine and vinylamide based polyalcohol, melamine-formaldehyde and urea-formaldehyde resins.Suitably, silica-based sols and at least a CATION or amphiphilic polymers, the preferred cationic polymer is in conjunction with use.Cationic starch and cationic polyacrylamide be particularly preferred polymer and they can be separately, use together or with other polymer such as other cationic polymer or anionic polyacrylamide mutually.The molecular weight of host polymer is higher than 1000000 suitably, preferably is higher than 2000000.The upper limit is not crucial; It can be about 50000000, common 30000000, about suitably 25000000.But the molecular weight of the polymer of natural origin can be higher.

If silica-based sols of the present invention and particle are used in combination with above-mentioned host polymer, further preferred use at least a so-called and as low molecular weight (following LMW) cationic organic polymer of anion refuse agent for capturing (ATC).ATC is neutralization and/or the fixative that is used for being present in the harmful anion material of raw material known in the art, and it is with draining with keep being used in combination of auxiliary agent and can further improve draining usually and/or keep effect.The LMW cationic organic polymer can be from natural or synthetic, and be preferably the LMW synthetic polymer.Suitable this organic polymer comprise cationic organic polymer that LMW is highly charged such as polyamine, daiamid, polyethylene imine based, based on the homopolymers and the copolymer of diallyldimethylammonium chloride, (methyl) acrylamide and (methyl) acrylate.About the molecular weight of host polymer, the molecular weight of LMW cationic organic polymer is preferably lower; It is at least 1000 suitably, preferably is at least 10000.The upper limit of molecular weight is generally about 700000, about suitably 500000, common about 200000.The preferred compositions of the polymer that can use with silica-based sols of the present invention comprises LMW cationic organic polymer and host polymer for example cationic starch and/or cationic polyacrylamide, the combination of anionic polyacrylamide and the combination of cationic starch and/or cationic polyacrylamide and anionic polyacrylamide.

According to draining of the present invention and keep the component of auxiliary agent can be in a usual manner and add in the raw material with any order.Comprise the draining of silica base particle and organic polymer such as host polymer and keep auxiliary agent if use, preferably before adding silica base particle, polymer is added in the raw material, even can adopt opposite charging sequence.Add host polymer before further preferably being added in the shearing step that is selected from pumping, mixing, cleaning etc., and after this shearing step, add silica base particle.If use, the LMW cationic organic polymer preferably added in the raw material before adding host polymer.In addition, LMW cationic organic polymer and host polymer (independent or mixed form) basically simultaneously add in the raw material, for example are disclosed in United States Patent (USP) 5858174, incorporate it into the present invention as a reference at this.LMW cationic organic polymer and host polymer preferably added in the raw material before adding silica base particle.

In a preferred embodiment of the invention, silica-based sols and particle combine as draining and keep auxiliary agent with at least a above-mentioned organic polymer and at least a aluminium compound.Aluminium compound can be used for further improving the draining and/or the retention performance of the material additive that comprises silica base particle.Suitable aluminium salt comprise alum, aluminate, aluminium chloride, aluminum nitrate and poly-aluminium compound such as polyaluminium chloride, poly aluminium sulfate, the poly-aluminium compound that comprises chloride and sulfate ion, aluminium silicate polymer-aluminum sulfate, and composition thereof.Poly-aluminium compound also can comprise other anion, for example the ion of ion phosphoric acid, organic acid such as citric acid and oxalic acid.Preferred aluminium salt comprises sodium aluminate, alum and poly-aluminium compound.Aluminium compound can add before or after adding silica base particle.In addition, aluminium compound can with silica-based sols basically simultaneously (mixing individually or with it) add, for example be disclosed in United States Patent (USP) 5846384, incorporate it into the present invention as a reference at this.In many cases, it is early stage to be adapted at technology usually, for example before other additive aluminium compound is added raw material.

According to draining of the present invention with keep the amount that the component of auxiliary agent adds in the raw material to be drained off and can in grace period, change, especially depend on the kind of component and number, batching kind, filer content, filling kind, feed point, etc.In general, the addition of each component obtains when not adding these components better draining and/or keeps effect.The addition of silica-based sols and particle generally is at least 0.001% weight, and at least 0.005% weight usually is with SiO ₂Calculate and based on dried raw material the not essential filler of i.e. cellulose fiber peacekeeping, and its upper limit generally is 1.0%, 0.5% weight suitably.The addition of host polymer generally is at least based on 0.001% of dried raw material, is at least 0.005% weight usually, and its upper limit is generally 3%, suitably 1.5% weight.If use the LMW cationic organic polymer in this technology, its addition is based at least 0.05% of the dry of raw material to be drained off.Suitably, this amount is 0.07-0.5%, preferred 0.1-0.35%.If in this technology, use aluminium compound, add that total amount in the raw material to be drained off depends on the kind of used aluminium compound and from its required effect.For example, well known employing aluminium compound is as the precipitating agent of abietyl sizing agent.The total amount that adds is at least 0.05% usually, with Al ₂O ₃Calculate and based on dried raw material.This amount is 0.1-3.0% suitably, preferred 0.5-2.0%.

Other additive that is usually used in papermaking certainly can be used in combination according to additive of the present invention, for example dry strength agent, wet strength agent, fluorescent whitening agent, dyestuff, sizing agent such as rosin sizing agent and cellulose reactive sizing agent, as alkyl and alkenyl ketenes dimer and ketenes polymer, alkyl and alkenyl succinic anhydrides, etc.Cellulose suspension or raw material also can comprise the ore deposit filler of kind commonly used, for example kaolin, china clay, titanium dioxide, gypsum, talcum and natural and synthetic calcium carbonate such as chalk, crushed marble and winnofil.

The inventive method can be used for producing paper.Term used herein " paper " not only comprises paper and production thereof certainly, but also comprises sheet material or paper web shape product such as plate and the cardboard and the production thereof of other cellulose fiber.This method can be used for producing paper by different types of cellulose fibrous suspension, and this suspension should comprise suitably based on dry 25% weight these fibers of preferred at least 50% weight at least.This suspension can be based on the fiber from chemical pulp such as sulfate pulp, sulfite pulp and organosol slurry, mechanical pulp such as thermodynamics slurry, chemistry-thermodynamics slurry, refining slurry and soft wood pulp, and can based on optionally from the recycled fiber of de inked pulp, and composition thereof.The pH value of suspension, raw material can be in the scope of about 3-10.The pH value surpasses 3.5 suitably, and preferred 4-9.

The present invention further specifies by following examples, but has no intention to limit at this point.Unless refer else, umber and % relate separately to weight portion and % weight.

Embodiment 1

The standard silica sol is prepared as follows:

SiO ₂With Na ₂The mol ratio of O is 3.3 and SiO ₂Content be 27.1% 762.7 the gram sodium silicates be diluted with water to 3000 the gram, obtain a kind of SiO ₂Content is the silicate solutions (I) of 6.9% weight.2800 these silicate of gram or water glass solution are filled with the post of using the saturated strong-acid cation-exchange resin of hydrogen ion through one.Always in exchanger, collect SiO ₂Content is that 6.5% weight and pH value are 2.4 2450 gram-ion exchanged water glass or poly-silicic acid (II).The poly-silicic acid (II) of 1988 grams is fed in the reactor also with 12.3 gram water dilutions.6.9% silicate solutions (I) that under vigorous stirring, adds 173.9 grams subsequently.Gained solution heated 60 minutes under 85 ℃ subsequently and is cooled to 20 ℃ subsequently.Gained silica sol (1a) has following characteristic:

Colloidal sol 1a (reference): SiO ₂Content=7.3% weight, mol ratio SiO ₂/ Na ₂O=40, pH value=10.2, S value=29%, viscosity=2.2 centipoises, specific area=530 meter ²/ gram SiO ₂With 39 meters ²/ gram the hydrosol.

Produce other two kinds of silica sol (colloidal sol 1b and colloidal sol 1c) with following characteristic:

Colloidal sol 1b (reference): SiO ₂Content=7.3% weight, mol ratio SiO ₂/ Na ₂O=63, pH value=10.0, S value=26%, viscosity=2.7 centipoises, specific area=500 meter ²/ gram SiO ₂With 36.5 meters ²/ gram the hydrosol.

Colloidal sol 1c (reference): SiO ₂Content=5.4% weight, mol ratio SiO ₂/ Na ₂O=35, pH value=9.8, S value=32%, viscosity=1.6 centipoises, specific area=690 meter ²/ gram SiO ₂With 37 meters ²/ gram the hydrosol.

Embodiment 2

According to 6 kinds of silica base particles of the present invention by being similar to poly-silicic acid (II) and the SiO that makes by the same ion exchange process ₂Content is the poly-silicic acid preparation of 5.46% weight.The SiO that under vigorous stirring, in 102.0 kilograms of poly-silicic acid, adds 1.46 kilograms ₂/ Na ₂O obtains a kind of mol ratio SiO than the sodium silicate that is 3.3 ₂/ Na ₂O is 54.0 solution.This solution 60 ℃ of following heat treatments 2 hours 20 minutes and be cooled to 20 ℃, is concentrated into SiO with product thus ₂Content is 15.6% weight.Now this intermediate colloidal sol product is divided into 6 independent sample a-f.Further with the NaOH alkalization, sample d-f water glass treatment obtains SiO to sample a-c ₂/ Na ₂The O mol ratio is that 21.5-34.0 and silica content are the colloidal sol of about 15.0% weight.The colloidal sol of the silica base particle of gained has the characteristic that table 1 provides:

Table 1

Colloidal sol	Mol ratio [SiO 2/Na 2O]	The pH value	S value [%]	Viscosity [centipoise]	Specific area [rice 2/ gram SiO 2]	Specific area [rice 2/ gram the hydrosol]
							Colloidal sol 2a colloidal sol 2b colloidal sol 2c colloidal sol 2d colloidal sol 2e colloidal sol 2f	21.5 28.0 34.0 21.5 28.0 33.0	10.7 10.3 10.0 10.7 10.3 10.0	31 30 29 31 29 29	17 29 40 20 34 38	720 710 690 680 670 680	108.0 106.5 103.5 102.0 100.5 102.0

Embodiment 3

Will be as in embodiment 2, making and alkalizing to mol ratio SiO with waterglass by above-mentioned ion-exchange process ₂/ Na ₂O is that 54.0 poly-silicic acid (II) was 60 ℃ of following heat treatments 1 hour.The mol ratio SiO that in 58 kilograms of these products, adds 7.25 kilograms ₂/ Na ₂O be 3.3 and silica content be the dilution water glass of 5.5% weight.It is 15.2% weight and mol ratio SiO that the colloidal sol of the silica base particle of gained is concentrated into silica content ₂/ Na ₂O=24, pH value=10.7, S value=34, viscosity=9.0 centipoises and specific area=760 meter ²/ gram SiO ₂With 115.5 meters ²/ gram the hydrosol.

Embodiment 4

With SiO ₂Content is the poly-silicic acid (II) of 1000 grams of 5.5% weight and the SiO of 14.5 grams ₂Content is 27.1% weight and mol ratio SiO ₂/ Na ₂O is that 3.3 water glass solution mixes under vigorous stirring, obtains a kind of mol ratio SiO ₂/ Na ₂O be 51 and silica content be the product of 5.8% weight, then 60 ℃ of down heating 1.5 hours and to be concentrated into silica content subsequently be 16.7% weight SiO ₂The products therefrom of 283 grams is mixed with 33.0 gram NaOH, obtain the colloidal sol (colloidal sol 4) of silica base particle, wherein SiO ₂Content=15.2% weight, mol ratio SiO ₂/ Na ₂O=21, pH value=10.6, S value=32%, viscosity=14.2 centipoises and specific area=720 meter ²/ gram SiO ₂With 109.4 meters ²/ gram the hydrosol.

Embodiment 5

Repetition is according to the general step of embodiment 3, and just heat treatment was carried out 1.25 hours and concentrated proceeding to higher silica content.Prepare two kinds of silica base particle colloidal sols; Colloidal sol 5a and colloidal sol 5b.The SiO of colloidal sol 5a ₂Content=18% weight, mol ratio SiO ₂/ Na ₂O=18, pH value=10.7, S value=36%, viscosity=18 centipoises and specific area=700 meter ²/ gram SiO ₂With 126 meters ²/ gram the hydrosol.The SiO of colloidal sol 5b ₂Content=20% weight, mol ratio SiO ₂/ Na ₂O=18, pH value=10.7, S value=37%, viscosity=31 centipoises and specific area=700 meter ²/ gram SiO ₂With 140 meters ²/ gram the hydrosol.

Embodiment 6

Utilization derives from Akribi, and the dynamic drainage analyzer (DDA) of Sweden is assessed drainage performance, when removing stopper and when the net side relative with that side that has raw material applies vacuum, measuring the time of this net of raw material discharging process of setting volume.

Used raw material is based on the blend of 60% bleaching birch kraft pulp and 40% bleaching pine sulfate pulp, wherein added 30% grinding calcium carbonate as filler.The raw material volume is 800 milliliters, and denseness is 0.25% and pH value about 8.0.The conductance of raw material is adjusted to 0.47mS/cm by adding sodium sulphate.

In test, silica-based sols is used in combination with cationic polymer Raisamyl 142, and in a kind of routine of the latter-starch of high-cationization, substitution value is 0.042, adds in the raw material in the amount (with the dried starch of dried material system) of 12 kg/ton.Silica-based sols according to embodiment 1-4 is tested in this embodiment.In addition, for relatively, test colloidal sol 6a and 6b.Colloidal sol 6a is a kind of commercially available silica sol, S value=45% wherein, SiO ₂Content=15.0% weight, mol ratio SiO ₂/ Na ₂O=40, viscosity=3.0 centipoises, specific area=500 meter ²/ gram SiO ₂With 75 meters ²/ gram the hydrosol.Colloidal sol 6b is another kind of commercially available silica sol, S value=36% wherein, SiO ₂Content=10.0% weight, mol ratio SiO ₂/ Na ₂O=10, viscosity=2.5 centipoises, specific area=880 meter ²/ gram SiO ₂With 88 meters ²/ gram the hydrosol.The addition of silica-based sols is 0.5 kg/ton, with SiO ₂Calculate and based on dried material system.

In whole test, raw material speed with 1500rpm in the iris type jar is stirred, and following adding chemicals: i) cationic starch is added in the raw material, stirred then 30 seconds, ii) silica-based sols is added in the raw material, stirred then 15 seconds, and iii) drained this raw material, write down water discharge time simultaneously automatically.

The water discharge time of different silica-based sols provides in table 2:

Table 2

Silica-based sols	Water discharge time [second]
		Colloidal sol 1a (reference) colloidal sol 1b (reference) colloidal sol 1c (reference) colloidal sol 2d colloidal sol 3 colloidal sols 4 colloidal sol 6a (reference) colloidal sol 6b (reference)	12.0 11.1 12.0 9.7 9.5 9.4 12.0 9.8

Embodiment 7

According to the general step commentary performance of embodiment 6, just the denseness of raw material be 0.3% and the pH value be about 8.5.Retention performance utilizes nephelometer to assess by the turbidity of measuring filtrate (by draining the plain boiled water that raw material obtains).

Silica-based sols according to embodiments of the invention 5 is tested at the colloidal sol 6a that is used for comparison.Table 3 has provided the water discharge time that silica base particle obtains under various dosage (kg/ton), with SiO ₂The meter and based on dried material system.Only add cationic starch (12 kg/ton are calculated with the dried starch based on dried material system), water discharge time is 15.8 seconds as a result.

Table 3

Silica-based sols	At following SiO 2Water discharge time under the dosage (second)/turbidity (NTU)
						0.5 kg/ton	1.0 kg/ton	1.5 kg/ton	2.0 kg/ton	3.0 kg/ton
	Colloidal sol 6a (reference) colloidal sol 5a colloidal sol 5b	11.1/- 9.0/- 8.9/-	8.8/59 7.1/52 6.9/-	7.9/58 6.3/50 6.3/-	7.1/54 5.2/52 5.7/-						6.8/60 5.7/53 6.0/-

Claims (7)

1. produce the method for paper, comprising:

(a) provide a kind of water slurry that comprises the dispensable filler of cellulose fiber peacekeeping;

(b) provide a kind of hydrosol that comprises silica base particle that does not have aluminium basically, the specific area of described colloidal sol is at least 90 meters ²/ gram the hydrosol, and the specific area of described silica base particle is lower than 1000 meters ²/ gram SiO ₂

(c) provide at least a charged organic polymer;

(d) the described charged organic polymer and the described hydrosol that comprises silica base particle are added in the described suspension;

(e) with moulding on the net of gained suspension and draining.

2. produce the method for paper, comprising:

(a) provide a kind of water slurry that comprises the dispensable filler of cellulose fiber peacekeeping;

(b) providing a kind of does not have aluminium, specific area to be at least 90 meters basically ²/ gram the hydrosol and S value are the hydrosol that comprises silica base particle of 10-45%;

(c) provide at least a charged organic polymer;

(d) the described charged organic polymer and the described hydrosol that comprises silica base particle are added in the described suspension;

(e) with moulding on the net of gained suspension and draining.

3. according to the method for claim 1 or 2, be characterised in that the specific area of described colloidal sol is a 95-150 rice ²/ gram the hydrosol.

4. according to the method for claim 1 or 2, be characterised in that the specific area of described silica base particle is at least 550 meters ²/ gram SiO ₂

5. according to the method for claim 1 or 2, be characterised in that described charged organic polymer is cationic starch or cationic polyacrylamide.

6. according to the method for claim 1 or 2, be characterised in that before the hydrosol that will comprise silica base particle added suspension, it was 0.05-5% weight that the described hydrosol is diluted to silica content.

7. according to the method for claim 1 or 2, be characterised in that, the amount of the described hydrosol that comprises silica base particle with 0.005-0.5% weight added in the described suspension, with SiO ₂Calculate and based on the not essential filler of doing of cellulose fiber peacekeeping.