CA1334324C - Process for the production of paper - Google Patents
Process for the production of paperInfo
- Publication number
- CA1334324C CA1334324C CA000609515A CA609515A CA1334324C CA 1334324 C CA1334324 C CA 1334324C CA 000609515 A CA000609515 A CA 000609515A CA 609515 A CA609515 A CA 609515A CA 1334324 C CA1334324 C CA 1334324C
- Authority
- CA
- Canada
- Prior art keywords
- process according
- colloid
- aluminate
- synthetic polymer
- anionic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
- D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
- D21H17/45—Nitrogen-containing groups
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
- D21H17/68—Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Dispersion Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Paper (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
- Making Paper Articles (AREA)
- Polarising Elements (AREA)
- Electronic Switches (AREA)
Abstract
A method for the production of paper by forming and dewatering a suspension of cellulose containing fibres on a wire. The forming and dewatering takes place in the pre-sence of an anionic, inorganic colloid, an aluminate and a cationic synthetic polymer. The process gives improved dewatering and improved retention of fines and optional fillers.
Description
A process for the production of paper The present invention relates to a process for the production of paper utilizing an improved retention- and dewatering system. More particularly the invention relates to the use of a combination of a cationic synthetic poly-mer, an anionic inorganic colloid and aluminate as reten-tion- and dewatering system in papermaking.
It is previously known to use combinations of cat-ionic retention agents and inorganic colloids as retention-and dewatering agents in the production of paper. TheEuropean patent application 0218674 discloses the use of polyacrylamide in combination with anionic silica sols as binders and retention agents. It is assumed that the colloidal particles of the sols with their strong charges produce a cross-linXing of the polymeric retention agents and that very good retention and dewatering effect is obtained through this. From the British patent 2015614 it is further known to use polymeric cationic retention agents in combination with polyalllm;mlm compounds. It is further known from the US patent 4,643,801 to use a combination of a cationic starch, an anionic silica sol and an anionic high molecular weight polymer, particularly an anionic polyacrylamide, as a binder in papermaking. The three c~mrQnent system according to the US patent can be used with additional aluminum cu.u~ounds, such as alum, sodium aluminate or polyhydroxyalllm;nllm chloride.
According to the present invention it has been found that the retention- and dewatering effect in paperm~k~ng is improved if an aluminate is used in combination with cationic, synthetic polymer and an anionic inorganic colloid. As the dewatering effect is increased the speed of the paper~ch~ne can be increased and, further, less water will have to be dried off in the drying section of the paper machine.
The present invention thus relates to a process for the production of paper by fonming and dewatering a suspen-sion of cellulose containing fibres, and optionally fill-ers, on a wire whereby the forming and dewatering takes ~ - 2 1 334324 place in the presence of an anionic inorganic colloid, an aluminate and a cationic synthetic polymer.
The three components can be added to the fibre stoc~
in arbitrary order. The best effect is obtained if the aluminate is added to the stock first, followed by addition of cationic synthetic polymer and then the anionic inor-ganic colloid. A considerable improvement, in comparison with known techn i que, is obtained also when the anionic inorganic colloid is first added to the stock and the cationic polymer and the aluminate are added subsequently, in any order. Separate addition of the three respective components is preferred although it is possible to pre-mix two of the components before the addition.
As cationic synthetic polymers for use according to the present invention such cationic, organic nitrogen containing polymers which are conventionally used as retention agents and/or wet strength agents in papermaking are suitable. Particularly suitable are cationic polyacryl-amides, polyethyleneimines, polyamine resins and polyamido-amine resins etc. Polyamine resins and polyamidoamineresins are suitably used in their epichlorohydrine modified form. Other cationic synthetic polymers which can also be used are the cationic melamine-formaldehyde and urea--formaldehyde wet strength resins. The amount of the cat-ionic synthetic polymer should suitably be within the rangeof from 0.01 to 3 per cent by weight, preferably within the range of from 0.03 to 2 per cent by weight, based on dry fibres and optional fillers.
The anionic inorganic colloids which are used are per se previously known for use in paperm~k~ ng. As examples of such colloids can be mentioned montmorillonite, ben-tonite, titanyl sulphate sols, silica sols, a~ n-7m modified silica sols or all~m~nllm silicate sols. The terms colloid and colloidal indicate very small particles. The 3s particles of the anionic substances should suitably have a specific surface area above 50 m2/g, more suitably above 100 m2/g, and preferably within the range of 50 to 1000 m2/g. Silica based colloids are the preferred anionic inor-- 3 1 3~32~
ganic colloid.
Particularly suitable silica based colloids are the silica sols with colloidal particles as disclosed in the European patent 41045, and the aluminum containing silica sols which are di6clo~ed in the European patent application 0218674. The colloidal silica in the sols should prefer-ably have a specific surface area of 50 to 1000 m2/g and more preferably of about 100 to 1000 m2~g, and the best results have been obtained when the specific surface area has been about 300 to 700 m2/g. It has been ~ound that the colloidal silica particles should suitably have a particle size below 20 nm and preferably from about 10 down to about 1 nm (a colloidal silica particle having a specific surfacearea of about 550 m2/g corresponds to an average particle size of about 5 nm). Good results are obtained with the mentioned silica sols in the form of an alkali stabilized sol which contains about 2 to 60 per cent by weight of SiO2, preferably from about 4 to 30 per cent by weight of SiO2. The silica sol can be stabilized with alkali in a molar ratio of SiO2:M2O of from 10:1 to 300:1, preferably 15:1 to lOO:l (M is an ion from the group Na, K, Li and NH4). As mentioned above good results are obtained using colloidal particles which have at least a surface layer of aluminum silicate or al~ nllm modified silica sol, so that the surface groups of the particles contain silicon and aluminum atoms in a ratio of from 9.5:0.5 to 7.5:2.5 and the given surfaces and particle sizes also apply to these sols. Silica sols which fulfil the above given specific-. ations are available commercially, eg from Eka Nobel AB.
The amount of anionic colloid which is added to thestoc~ should suitably be within the range of from 0.005 to -2 per cent by weight, preferably from 0.01 to 0.4 per cent by weight, based on dry cellulose fibres and optional fillers. The concentration of the colloid, preferably colloidal silica, in the sol- added.to the stoc~ is not critical. From a practical point of view it is suitable .....
, . . -: . . . . .
that the sols at the addition to the stock have a con-centration of from 0.05 to 5.0 per cent by weight.
Aluminate refers to alkali aluminate which per se is well-known for use in paper productlon, particularly for hydrophobing with rosin. Sodium aluminate (Na2A12O4) is preferably used, but potassium aluminate can of course also be used even if is less advantageous from an economical point of view. The amount of aluminate can vary within wide limits. The addition of aluminate to the stock is suitably made in the form of aqueous solutions and the concentration in the solutions is not critical but is ad;usted with regard to practical considerations. According to the invention it has been found that already very small amounts of aluminate, with regard to the amount`of anionic inor-ganic colloid, give considerable improvements in thedewatering effect. An improvement is obtained already at a weight ratio aluminate, calculated as A12O3, to inorganic colloid of 0.01:1. The upper limit is not critical. How-ever, no improvements worth mentioning are obtained when the ratio of aluminate to inorganic colloid exceeds 3:1.
The ratio is suitably within the range of from 0.02:1 to 1.5:1 and preferably from 0.05:1 to 0.7:1. The given ratios all relate to weight ratio between aluminate, calculated as A12O3, and the inorganic colloid.
The improved retention- and dewatering effect with the system of the invention is obtained over a broad pH
range for the stock. The pH can be within the range from about 4 to about 10. The pH is suitably above 5 and prefer-ably within the range of from 6 to 9. If the desired pH is not reached by the addition of the aluminate solution~
which in itself is alkaline, the pH of the stock can be ad~usted for example by addition of sodium hydroxide. If Alk~l~ne buffering fillers are used, for example chalk, a suitable pH is normally reached without ad~ustments. Other fillers than chalk can of course also be used, but then care has to be taken so that the pH of the stock is kept within the above given limits.
At paper production according to the invention mineral fillers of conventional types can be used, for example kaolin, titanium dioxide, gypsum, chalk and talcum.
The term "mineral filler" is herein used to include, in addition to these fillers, also wollastonite and glass fibres and also mineral low density fillers, such as expanded perlite. The mineral filler is usually added in the form of an aqueous slurry in conventional concen-trations used for such fillers. The filler can optionally be treated before the addition to the stoc~ with components of the dewatering- and retention- system of the invention, for example by treatment with the cationic synthetic polymer and the aluminate or the inorganic colloid, where-after the remaining component is added to the stock.
The three-component system of the invention can be used at production of paper from different types of stocks of cellulose cont~;n;ng fibres. The stocks should suitably contain at least 50 per cent by weight of cellulose con-tA;n;ng fibres. The three-component system can for example be used for stocks of fibres from chemical pulp, such as sulphate and sulphite pulp, thermomech~n;cal pulp, refiner pulp and groundwood pulp from as well hardwood as softwood.
It can of course also be used for stocks from recycled fibres. The terms paper and papermaking, which are used herein do of course not only include paper and its produc-tlon, but also other cellulose fibre conta~n~ng sheet orweb form products, such as pulp sheet, board and cardboard and their production.
The process according the invention can be carried out in per se known manner and with other additions to the fibre stock, such as sizing agents etc.
The invention is further illustrated in the following examples wherein parts and per cent relate to parts by weight and per cent by weight unless otherwise stated.
Example 1 In the following tests the dewaterlng effect was investigated by means of a "Canadian Freeness Tester", which is the usual method for characterizing the dewatering capability according to SCAN-C 21:65.
The stoc~ was based on bleached birchJpine sulphate pulp (60:40) and contained 30 per cent by weight of chalk.
The pH of the stock was 8.5 and CSF was 300 ml.
In the table amounts for the chemical additions refer to ton dry stock system (fibres+fillers). The anionic colloid was an alkali stabilized silica sol with a specific surface area of 500 m2/g. The cationic synthetic polymer was a cationic polyacrylamide of medium cationicity sold by Allied Colloids under the name Percol 292. The sodium aluminate was added in the form of a 0.025% aqueous solu-tion and the given amounts of aluminate are expressed as kg A12O3. The additions of chemicals were made to 1 1 diluted stock (about 0.3~) with intervals of 15 seconds under agitation in the order aluminate, cationic polymer, inor-ganic colloid. The flocked stock was transferred to thefreeness apparatus and measurements were made 15 seconds after the last addition. The water which is collected is a measurement of the dewatering effect and is expressed in ml Canadian Standard Freeness (CSF). The water obtained in the tests using the three components was very clear and this shows that a good retention of the fines material to the flocks had also been obtained.
Test 2 3 Cationic Anionic CSF
No. kg/t polymer kq/t Colloid kq/t ml 1 - - _ 300 2 - 0.3 - 370 3 - 0.6 - 385 4 - 0.9 - 390 0.15 - - 290 6 0.15 0.3 - 350 7 - - 1.0 295 8 0.15 - 1.0 290 9 - 0.3 0.5 420 - 0.3 1.0 430 35 11 - 0.3 1.5 440 12 0.075 0.3 0.5 495 13 0.15 0.3 1.0 520 14 0.225 0.3 1.5 515 - trade mark _ Test A123 Cationic Anionic CSF
No. kg/t polymer kg/t Colloid ~/t ml - 0.6 0.5 42S
16 - 0.6 1.0 490 ~5 17 - 0.6 1.5 510 18 0.075 0.6 0.5 4gs 19 0.15 0.6 l.o 570 0.225 0.6 1.5 585 As evident also use o~ very small amounts of alumi-nate gives a considerably improved dewatering e~fect forthe system of cationic polymer and anionic colloid. The corresponding effect of the aluminate is not obtained if it is used in combination with only cationic polymer or only anionic colloid.
Example 2 This example corresponded entirely to example 1 with the only difference that other cationic synthetic polymers were used. These were A) an epichlorohydrine modified polyamidoamine resin sold by Hercules Inc. under the name Kymene 557 H and B) a modified polyamine resin sold by Hercules Inc. under the name Delfloc -50.
Test A123 Cat. PolymerAnionic CSF
No. kg/t type;~g/tColloid kg/t ml 2 - _ A; 0.6 - 305 3 - A; 1.2 - 315 4 - A; 2.4 - 315 - A; 1.2 0.5 325 6 - A; 1.2 1.0 330 7 - A; 1.2 1.5 310 8 0.075 A; 1.2 0.5 360 9 0.15 A; 1.2 1.0 390 0.225 A; 1.2 1.5 410 11 0.30 A; 1.2 2.0 395 3512 - B; 1.2 - 290 13 - B; 1.2 1.5 280 14 0.225 B; 1.2 1.5 335 - trade mark ~r 1~
Example 3 In this example a groundwood stock was used which did not contain any fillers. To the stock 0.5 g/l of Na2SO4.10H2O had been added to give an ion strength corresponding to the one under large scale conditions. The cationic polymer was the same polyacrylamide as in Exampl~
1. The anionic colloid was an all~mi nll~ modified, 15% alkali stabilized, silica sol where the surface of the colloidal particles had been modified with 9% aluminum atoms and the surface area of the particles was 500 m2/g. The order of addition was sodium aluminate, cationic polymer followed by anionic colloid. Tests were made both with a stock pH of 6 and a stock pH of 7.5 whereby the pH had been adjusted with diluted H2SO4 and diluted NaOH respectively.
15 Test A12O3 Cationic Anionic CSF
No kg/t polymer kg/tcolloid kg/t ml pH 6.0 2 - 0.3 - lg0 3 - 0.6 - 220 4 - 0.9 - 245 s - 1.2 - 250 6 - 0.6 0.5 275 7 - 0.6 1.0 305 8 - 0.6 1.5 300 9 0.075 0.6 0.5 325 0.15 0.6 1.0 345 11 0.225 0.6 1.5 350 pH 7.5 12 - 0.6 - 220 13 - 0.6 0.5 245 14 - 0.6 1.0 270 - 0.6 1.5 275 16 0.075 0.6 0.5 295 17 0.15 0.6 1.0 325 18 0.225 0.6 1.5 340 19 - 0.9 1.5 310 0.225 0.9 1.5 370 Example 4 In these tests a groundwood stock with addition of 0.5 g/l of Na2SO4.10H2O was used as in Example 3. The pH of the stock was 6.5 and the added chemicals were sodium aluminate, a cationic polyethylene lmine sold by BASF under the name Polymin SK and an anionic colloid which was a bentonite colloid having a specific surface area of from about 400 to 800 m2/g in water.
10 Test A123 Cationic Anionic CSF
No. kg/t polymer kq/t colloid kq/t ml 2 - 0.-3 - 175 3 - 0.6 - 230 4 - 0.9 - 300 - 1.2 - 310 6 - 0.6 0.5 260 7 - 0.6 1.0 280 8 - 0.9 1.0 340 9 0.075 0.6 0.5 . 295 0.15 0.6 1.0 335 11 0.15 0.9 1.0 390 - trade mark -~
It is previously known to use combinations of cat-ionic retention agents and inorganic colloids as retention-and dewatering agents in the production of paper. TheEuropean patent application 0218674 discloses the use of polyacrylamide in combination with anionic silica sols as binders and retention agents. It is assumed that the colloidal particles of the sols with their strong charges produce a cross-linXing of the polymeric retention agents and that very good retention and dewatering effect is obtained through this. From the British patent 2015614 it is further known to use polymeric cationic retention agents in combination with polyalllm;mlm compounds. It is further known from the US patent 4,643,801 to use a combination of a cationic starch, an anionic silica sol and an anionic high molecular weight polymer, particularly an anionic polyacrylamide, as a binder in papermaking. The three c~mrQnent system according to the US patent can be used with additional aluminum cu.u~ounds, such as alum, sodium aluminate or polyhydroxyalllm;nllm chloride.
According to the present invention it has been found that the retention- and dewatering effect in paperm~k~ng is improved if an aluminate is used in combination with cationic, synthetic polymer and an anionic inorganic colloid. As the dewatering effect is increased the speed of the paper~ch~ne can be increased and, further, less water will have to be dried off in the drying section of the paper machine.
The present invention thus relates to a process for the production of paper by fonming and dewatering a suspen-sion of cellulose containing fibres, and optionally fill-ers, on a wire whereby the forming and dewatering takes ~ - 2 1 334324 place in the presence of an anionic inorganic colloid, an aluminate and a cationic synthetic polymer.
The three components can be added to the fibre stoc~
in arbitrary order. The best effect is obtained if the aluminate is added to the stock first, followed by addition of cationic synthetic polymer and then the anionic inor-ganic colloid. A considerable improvement, in comparison with known techn i que, is obtained also when the anionic inorganic colloid is first added to the stock and the cationic polymer and the aluminate are added subsequently, in any order. Separate addition of the three respective components is preferred although it is possible to pre-mix two of the components before the addition.
As cationic synthetic polymers for use according to the present invention such cationic, organic nitrogen containing polymers which are conventionally used as retention agents and/or wet strength agents in papermaking are suitable. Particularly suitable are cationic polyacryl-amides, polyethyleneimines, polyamine resins and polyamido-amine resins etc. Polyamine resins and polyamidoamineresins are suitably used in their epichlorohydrine modified form. Other cationic synthetic polymers which can also be used are the cationic melamine-formaldehyde and urea--formaldehyde wet strength resins. The amount of the cat-ionic synthetic polymer should suitably be within the rangeof from 0.01 to 3 per cent by weight, preferably within the range of from 0.03 to 2 per cent by weight, based on dry fibres and optional fillers.
The anionic inorganic colloids which are used are per se previously known for use in paperm~k~ ng. As examples of such colloids can be mentioned montmorillonite, ben-tonite, titanyl sulphate sols, silica sols, a~ n-7m modified silica sols or all~m~nllm silicate sols. The terms colloid and colloidal indicate very small particles. The 3s particles of the anionic substances should suitably have a specific surface area above 50 m2/g, more suitably above 100 m2/g, and preferably within the range of 50 to 1000 m2/g. Silica based colloids are the preferred anionic inor-- 3 1 3~32~
ganic colloid.
Particularly suitable silica based colloids are the silica sols with colloidal particles as disclosed in the European patent 41045, and the aluminum containing silica sols which are di6clo~ed in the European patent application 0218674. The colloidal silica in the sols should prefer-ably have a specific surface area of 50 to 1000 m2/g and more preferably of about 100 to 1000 m2~g, and the best results have been obtained when the specific surface area has been about 300 to 700 m2/g. It has been ~ound that the colloidal silica particles should suitably have a particle size below 20 nm and preferably from about 10 down to about 1 nm (a colloidal silica particle having a specific surfacearea of about 550 m2/g corresponds to an average particle size of about 5 nm). Good results are obtained with the mentioned silica sols in the form of an alkali stabilized sol which contains about 2 to 60 per cent by weight of SiO2, preferably from about 4 to 30 per cent by weight of SiO2. The silica sol can be stabilized with alkali in a molar ratio of SiO2:M2O of from 10:1 to 300:1, preferably 15:1 to lOO:l (M is an ion from the group Na, K, Li and NH4). As mentioned above good results are obtained using colloidal particles which have at least a surface layer of aluminum silicate or al~ nllm modified silica sol, so that the surface groups of the particles contain silicon and aluminum atoms in a ratio of from 9.5:0.5 to 7.5:2.5 and the given surfaces and particle sizes also apply to these sols. Silica sols which fulfil the above given specific-. ations are available commercially, eg from Eka Nobel AB.
The amount of anionic colloid which is added to thestoc~ should suitably be within the range of from 0.005 to -2 per cent by weight, preferably from 0.01 to 0.4 per cent by weight, based on dry cellulose fibres and optional fillers. The concentration of the colloid, preferably colloidal silica, in the sol- added.to the stoc~ is not critical. From a practical point of view it is suitable .....
, . . -: . . . . .
that the sols at the addition to the stock have a con-centration of from 0.05 to 5.0 per cent by weight.
Aluminate refers to alkali aluminate which per se is well-known for use in paper productlon, particularly for hydrophobing with rosin. Sodium aluminate (Na2A12O4) is preferably used, but potassium aluminate can of course also be used even if is less advantageous from an economical point of view. The amount of aluminate can vary within wide limits. The addition of aluminate to the stock is suitably made in the form of aqueous solutions and the concentration in the solutions is not critical but is ad;usted with regard to practical considerations. According to the invention it has been found that already very small amounts of aluminate, with regard to the amount`of anionic inor-ganic colloid, give considerable improvements in thedewatering effect. An improvement is obtained already at a weight ratio aluminate, calculated as A12O3, to inorganic colloid of 0.01:1. The upper limit is not critical. How-ever, no improvements worth mentioning are obtained when the ratio of aluminate to inorganic colloid exceeds 3:1.
The ratio is suitably within the range of from 0.02:1 to 1.5:1 and preferably from 0.05:1 to 0.7:1. The given ratios all relate to weight ratio between aluminate, calculated as A12O3, and the inorganic colloid.
The improved retention- and dewatering effect with the system of the invention is obtained over a broad pH
range for the stock. The pH can be within the range from about 4 to about 10. The pH is suitably above 5 and prefer-ably within the range of from 6 to 9. If the desired pH is not reached by the addition of the aluminate solution~
which in itself is alkaline, the pH of the stock can be ad~usted for example by addition of sodium hydroxide. If Alk~l~ne buffering fillers are used, for example chalk, a suitable pH is normally reached without ad~ustments. Other fillers than chalk can of course also be used, but then care has to be taken so that the pH of the stock is kept within the above given limits.
At paper production according to the invention mineral fillers of conventional types can be used, for example kaolin, titanium dioxide, gypsum, chalk and talcum.
The term "mineral filler" is herein used to include, in addition to these fillers, also wollastonite and glass fibres and also mineral low density fillers, such as expanded perlite. The mineral filler is usually added in the form of an aqueous slurry in conventional concen-trations used for such fillers. The filler can optionally be treated before the addition to the stoc~ with components of the dewatering- and retention- system of the invention, for example by treatment with the cationic synthetic polymer and the aluminate or the inorganic colloid, where-after the remaining component is added to the stock.
The three-component system of the invention can be used at production of paper from different types of stocks of cellulose cont~;n;ng fibres. The stocks should suitably contain at least 50 per cent by weight of cellulose con-tA;n;ng fibres. The three-component system can for example be used for stocks of fibres from chemical pulp, such as sulphate and sulphite pulp, thermomech~n;cal pulp, refiner pulp and groundwood pulp from as well hardwood as softwood.
It can of course also be used for stocks from recycled fibres. The terms paper and papermaking, which are used herein do of course not only include paper and its produc-tlon, but also other cellulose fibre conta~n~ng sheet orweb form products, such as pulp sheet, board and cardboard and their production.
The process according the invention can be carried out in per se known manner and with other additions to the fibre stock, such as sizing agents etc.
The invention is further illustrated in the following examples wherein parts and per cent relate to parts by weight and per cent by weight unless otherwise stated.
Example 1 In the following tests the dewaterlng effect was investigated by means of a "Canadian Freeness Tester", which is the usual method for characterizing the dewatering capability according to SCAN-C 21:65.
The stoc~ was based on bleached birchJpine sulphate pulp (60:40) and contained 30 per cent by weight of chalk.
The pH of the stock was 8.5 and CSF was 300 ml.
In the table amounts for the chemical additions refer to ton dry stock system (fibres+fillers). The anionic colloid was an alkali stabilized silica sol with a specific surface area of 500 m2/g. The cationic synthetic polymer was a cationic polyacrylamide of medium cationicity sold by Allied Colloids under the name Percol 292. The sodium aluminate was added in the form of a 0.025% aqueous solu-tion and the given amounts of aluminate are expressed as kg A12O3. The additions of chemicals were made to 1 1 diluted stock (about 0.3~) with intervals of 15 seconds under agitation in the order aluminate, cationic polymer, inor-ganic colloid. The flocked stock was transferred to thefreeness apparatus and measurements were made 15 seconds after the last addition. The water which is collected is a measurement of the dewatering effect and is expressed in ml Canadian Standard Freeness (CSF). The water obtained in the tests using the three components was very clear and this shows that a good retention of the fines material to the flocks had also been obtained.
Test 2 3 Cationic Anionic CSF
No. kg/t polymer kq/t Colloid kq/t ml 1 - - _ 300 2 - 0.3 - 370 3 - 0.6 - 385 4 - 0.9 - 390 0.15 - - 290 6 0.15 0.3 - 350 7 - - 1.0 295 8 0.15 - 1.0 290 9 - 0.3 0.5 420 - 0.3 1.0 430 35 11 - 0.3 1.5 440 12 0.075 0.3 0.5 495 13 0.15 0.3 1.0 520 14 0.225 0.3 1.5 515 - trade mark _ Test A123 Cationic Anionic CSF
No. kg/t polymer kg/t Colloid ~/t ml - 0.6 0.5 42S
16 - 0.6 1.0 490 ~5 17 - 0.6 1.5 510 18 0.075 0.6 0.5 4gs 19 0.15 0.6 l.o 570 0.225 0.6 1.5 585 As evident also use o~ very small amounts of alumi-nate gives a considerably improved dewatering e~fect forthe system of cationic polymer and anionic colloid. The corresponding effect of the aluminate is not obtained if it is used in combination with only cationic polymer or only anionic colloid.
Example 2 This example corresponded entirely to example 1 with the only difference that other cationic synthetic polymers were used. These were A) an epichlorohydrine modified polyamidoamine resin sold by Hercules Inc. under the name Kymene 557 H and B) a modified polyamine resin sold by Hercules Inc. under the name Delfloc -50.
Test A123 Cat. PolymerAnionic CSF
No. kg/t type;~g/tColloid kg/t ml 2 - _ A; 0.6 - 305 3 - A; 1.2 - 315 4 - A; 2.4 - 315 - A; 1.2 0.5 325 6 - A; 1.2 1.0 330 7 - A; 1.2 1.5 310 8 0.075 A; 1.2 0.5 360 9 0.15 A; 1.2 1.0 390 0.225 A; 1.2 1.5 410 11 0.30 A; 1.2 2.0 395 3512 - B; 1.2 - 290 13 - B; 1.2 1.5 280 14 0.225 B; 1.2 1.5 335 - trade mark ~r 1~
Example 3 In this example a groundwood stock was used which did not contain any fillers. To the stock 0.5 g/l of Na2SO4.10H2O had been added to give an ion strength corresponding to the one under large scale conditions. The cationic polymer was the same polyacrylamide as in Exampl~
1. The anionic colloid was an all~mi nll~ modified, 15% alkali stabilized, silica sol where the surface of the colloidal particles had been modified with 9% aluminum atoms and the surface area of the particles was 500 m2/g. The order of addition was sodium aluminate, cationic polymer followed by anionic colloid. Tests were made both with a stock pH of 6 and a stock pH of 7.5 whereby the pH had been adjusted with diluted H2SO4 and diluted NaOH respectively.
15 Test A12O3 Cationic Anionic CSF
No kg/t polymer kg/tcolloid kg/t ml pH 6.0 2 - 0.3 - lg0 3 - 0.6 - 220 4 - 0.9 - 245 s - 1.2 - 250 6 - 0.6 0.5 275 7 - 0.6 1.0 305 8 - 0.6 1.5 300 9 0.075 0.6 0.5 325 0.15 0.6 1.0 345 11 0.225 0.6 1.5 350 pH 7.5 12 - 0.6 - 220 13 - 0.6 0.5 245 14 - 0.6 1.0 270 - 0.6 1.5 275 16 0.075 0.6 0.5 295 17 0.15 0.6 1.0 325 18 0.225 0.6 1.5 340 19 - 0.9 1.5 310 0.225 0.9 1.5 370 Example 4 In these tests a groundwood stock with addition of 0.5 g/l of Na2SO4.10H2O was used as in Example 3. The pH of the stock was 6.5 and the added chemicals were sodium aluminate, a cationic polyethylene lmine sold by BASF under the name Polymin SK and an anionic colloid which was a bentonite colloid having a specific surface area of from about 400 to 800 m2/g in water.
10 Test A123 Cationic Anionic CSF
No. kg/t polymer kq/t colloid kq/t ml 2 - 0.-3 - 175 3 - 0.6 - 230 4 - 0.9 - 300 - 1.2 - 310 6 - 0.6 0.5 260 7 - 0.6 1.0 280 8 - 0.9 1.0 340 9 0.075 0.6 0.5 . 295 0.15 0.6 1.0 335 11 0.15 0.9 1.0 390 - trade mark -~
Claims (17)
1. A process for the production of paper by forming and dewatering a suspension of cellulose con-taining fibres on a wire, characterized in that the forming and dewatering takes place in the presence of an anionic inorganic colloid, an aluminate and a cationic synthetic polymer.
2. A process according to claim 1, characterized in that the anionic colloid is a silica based colloid.
3. A process according to claim 1 or 2, charac-terized in that the colloid is a silica sol, a silica sol with particles having at least a surface layer of aluminum silicate or an aluminum modified silica sol.
4. A process according to claim 1 or 2, charac-terized in that the particles of the colloid have a specific surface area within the range of from 50 to 1000 m2/g.
5. A process according to claim 3, characterized in that the particles of the colloid have a specific surface area within the range of from 50 to 1000 m2/g.
6. A process according to claim 3, characterized in that the particle size of the colloid is 20 nm at the most.
7. A process according to claim 1, 2, 5 or 6, characterized in that the cationic synthetic polymer is a cationic polyacrylamide, polyethyleneimine, polyamine or polyamidoamine.
8. A process according to claim 1, 2, 5 or 6, characterized in that the aluminate is added to the fibre suspension before the anionic inorganic colloid and the cationic synthetic polymer.
9. A process according to claim 3, characterized in that the aluminate is added to the fibre suspension before the anionic inorganic colloid and the cationic synthetic polymer.
10. A process according to claim 4, characterized in that the aluminate is added to the fibre suspension before the anionic inorganic colloid and the cationic synthetic polymer.
11. A process according to claim 7, characterized in that the aluminate is added to the fibre suspension before the anionic inorganic colloid and the cationic synthetic polymer.
12. A process according to claim 1, 2, 5, 6, 9, 10 or 11, characterized in that the amount of anionic inorganic colloid is within the range of from 0.005 to 2 per cent by weight, based on dry fibres and optional fillers.
13. A process according to claim 3, characterized in that the amount of anionic inorganic colloid is within the range of from 0.005 to 2 per cent by weight, based on dry fibres and optional fillers.
14. A process according to claim 4, characterized in that the amount of anionic inorganic colloid is within the range of from 0.005 to 2 per cent by weight, based on dry fibres and optional fillers.
15. A process according to claim 1, characterized in that the amount of cationic synthetic polymer is within the range of from 0.01 to 3 per cent by weight, based on dry fibres and optional fillers.
16. A process according to claim 7, characterized in that the amount of cationic synthetic polymer is within the range of from 0.01 to 3 per cent by weight, based on dry fibres and optional fillers.
17. A process according to claim 1, 2, 5, 6, 9, 10, 11, 13, 14, 15 or 16, characterized in that the weight ratio of aluminate, calculated as Al2O3, to anionic inorganic colloid is within the range of from 0.01:1 to 3:1.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE8803065-5 | 1988-09-01 | ||
| SE8803065A SE467627B (en) | 1988-09-01 | 1988-09-01 | SET ON PAPER MAKING |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1334324C true CA1334324C (en) | 1995-02-14 |
Family
ID=20373187
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000609515A Expired - Lifetime CA1334324C (en) | 1988-09-01 | 1989-08-28 | Process for the production of paper |
Country Status (13)
| Country | Link |
|---|---|
| EP (1) | EP0357574B1 (en) |
| JP (1) | JP2521539B2 (en) |
| AT (1) | ATE99010T1 (en) |
| AU (1) | AU605997B2 (en) |
| BR (1) | BR8904283A (en) |
| CA (1) | CA1334324C (en) |
| DE (1) | DE68911626T2 (en) |
| ES (1) | ES2048323T3 (en) |
| FI (1) | FI90448C (en) |
| NO (1) | NO171567C (en) |
| NZ (1) | NZ230427A (en) |
| PT (1) | PT91611B (en) |
| SE (1) | SE467627B (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4795531A (en) * | 1987-09-22 | 1989-01-03 | Nalco Chemical Company | Method for dewatering paper |
| US4927498A (en) * | 1988-01-13 | 1990-05-22 | E. I. Du Pont De Nemours And Company | Retention and drainage aid for papermaking |
| SE500367C2 (en) * | 1989-11-09 | 1994-06-13 | Eka Nobel Ab | Silica soles and process for making paper |
| DE69224063T4 (en) * | 1991-07-02 | 1999-02-25 | Eka Chemicals Ab, Bohus | METHOD FOR PRODUCING PAPER |
| DE4437118A1 (en) * | 1994-10-05 | 1996-04-11 | Technocell Dekor Gmbh & Co Kg | Base paper for decorative coating systems |
| SE9502184D0 (en) * | 1995-06-15 | 1995-06-15 | Eka Nobel Ab | A process for the production of paper |
| US5846384A (en) * | 1995-06-15 | 1998-12-08 | Eka Chemicals Ab | Process for the production of paper |
| US5595630A (en) * | 1995-08-31 | 1997-01-21 | E. I. Du Pont De Nemours And Company | Process for the manufacture of paper |
| SE9504081D0 (en) * | 1995-11-15 | 1995-11-15 | Eka Nobel Ab | A process for the production of paper |
| RU2213053C2 (en) * | 1999-05-04 | 2003-09-27 | Акцо Нобель Н.В. | Silicon dioxide-base sols |
| US7169261B2 (en) | 1999-05-04 | 2007-01-30 | Akzo Nobel N.V. | Silica-based sols |
| US6379501B1 (en) | 1999-12-14 | 2002-04-30 | Hercules Incorporated | Cellulose products and processes for preparing the same |
| EP1500745A1 (en) | 2002-04-03 | 2005-01-26 | Seiko PMC Corporation | Method for producing paper and agent for improving yield |
| FI121119B (en) † | 2003-04-15 | 2010-07-15 | Kemira Oyj | Procedure for making paper |
| US8245359B2 (en) | 2006-12-28 | 2012-08-21 | Tokyo Kinzoku Industry Co., Ltd. | Clip |
| CN103556532B (en) * | 2013-10-31 | 2016-01-20 | 东莞理文造纸厂有限公司 | A kind of retention aid for paper making and preparation method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE8403062L (en) * | 1984-06-07 | 1985-12-08 | Eka Ab | PAPER MANUFACTURING PROCEDURES |
| SE451739B (en) * | 1985-04-03 | 1987-10-26 | Eka Nobel Ab | PAPER MANUFACTURING PROCEDURE AND PAPER PRODUCT WHICH DRAINAGE AND RETENTION-IMPROVING CHEMICALS USED COTTONIC POLYACRYLAMIDE AND SPECIAL INORGANIC COLLOID |
| SE8701252D0 (en) * | 1987-03-03 | 1987-03-25 | Eka Nobel Ab | SET FOR PAPER MAKING |
| US4795531A (en) * | 1987-09-22 | 1989-01-03 | Nalco Chemical Company | Method for dewatering paper |
| US4927498A (en) * | 1988-01-13 | 1990-05-22 | E. I. Du Pont De Nemours And Company | Retention and drainage aid for papermaking |
| SE461156B (en) * | 1988-05-25 | 1990-01-15 | Eka Nobel Ab | SET FOR PREPARATION OF PAPER WHICH SHAPES AND DRAINAGE OWN ROOMS IN THE PRESENCE OF AN ALUMINUM SUBSTANCE, A COTTONIC RETENTION AND POLYMER SILICON ACID |
-
1988
- 1988-09-01 SE SE8803065A patent/SE467627B/en not_active IP Right Cessation
-
1989
- 1989-08-09 EP EP89850252A patent/EP0357574B1/en not_active Expired - Lifetime
- 1989-08-09 ES ES89850252T patent/ES2048323T3/en not_active Expired - Lifetime
- 1989-08-09 DE DE89850252T patent/DE68911626T2/en not_active Expired - Lifetime
- 1989-08-09 AT AT89850252T patent/ATE99010T1/en not_active IP Right Cessation
- 1989-08-25 BR BR898904283A patent/BR8904283A/en not_active IP Right Cessation
- 1989-08-25 NZ NZ230427A patent/NZ230427A/en unknown
- 1989-08-28 CA CA000609515A patent/CA1334324C/en not_active Expired - Lifetime
- 1989-08-28 AU AU40840/89A patent/AU605997B2/en not_active Expired
- 1989-08-29 JP JP1220495A patent/JP2521539B2/en not_active Expired - Lifetime
- 1989-08-30 FI FI894075A patent/FI90448C/en active IP Right Grant
- 1989-08-31 NO NO893500A patent/NO171567C/en not_active IP Right Cessation
- 1989-09-01 PT PT91611A patent/PT91611B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| NO171567C (en) | 1993-03-31 |
| ES2048323T3 (en) | 1994-03-16 |
| JPH0299692A (en) | 1990-04-11 |
| FI90448B (en) | 1993-10-29 |
| AU605997B2 (en) | 1991-01-24 |
| FI894075A0 (en) | 1989-08-30 |
| NO893500D0 (en) | 1989-08-31 |
| DE68911626D1 (en) | 1994-02-03 |
| AU4084089A (en) | 1990-03-29 |
| DE68911626T2 (en) | 1994-04-07 |
| NZ230427A (en) | 1991-06-25 |
| BR8904283A (en) | 1990-04-17 |
| ATE99010T1 (en) | 1994-01-15 |
| EP0357574A3 (en) | 1991-10-23 |
| EP0357574B1 (en) | 1993-12-22 |
| FI894075A (en) | 1990-03-02 |
| JP2521539B2 (en) | 1996-08-07 |
| SE8803065D0 (en) | 1988-09-01 |
| SE467627B (en) | 1992-08-17 |
| NO171567B (en) | 1992-12-21 |
| EP0357574A2 (en) | 1990-03-07 |
| NO893500L (en) | 1990-03-02 |
| PT91611A (en) | 1990-03-30 |
| FI90448C (en) | 1994-02-10 |
| SE8803065L (en) | 1990-03-02 |
| PT91611B (en) | 1995-05-31 |
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