EP0307795A2 - Cationically modified pigmentary dispersion and coating colour - Google Patents
Cationically modified pigmentary dispersion and coating colour Download PDFInfo
- Publication number
- EP0307795A2 EP0307795A2 EP19880114669 EP88114669A EP0307795A2 EP 0307795 A2 EP0307795 A2 EP 0307795A2 EP 19880114669 EP19880114669 EP 19880114669 EP 88114669 A EP88114669 A EP 88114669A EP 0307795 A2 EP0307795 A2 EP 0307795A2
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- EP
- European Patent Office
- Prior art keywords
- cationic
- pigment
- polymer
- coating
- degraded
- 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.)
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- 239000011248 coating agent Substances 0.000 title claims abstract description 74
- 238000000576 coating method Methods 0.000 title claims abstract description 74
- 239000006185 dispersion Substances 0.000 title claims abstract description 65
- 239000000049 pigment Substances 0.000 claims abstract description 88
- 239000002270 dispersing agent Substances 0.000 claims abstract description 28
- 229920006317 cationic polymer Polymers 0.000 claims abstract description 22
- 239000003086 colorant Substances 0.000 claims abstract description 22
- 239000002245 particle Substances 0.000 claims abstract description 22
- 239000000084 colloidal system Substances 0.000 claims abstract description 16
- 229920002451 polyvinyl alcohol Polymers 0.000 claims abstract description 16
- 230000001681 protective effect Effects 0.000 claims abstract description 16
- 229920000926 Galactomannan Polymers 0.000 claims abstract description 12
- 239000004372 Polyvinyl alcohol Substances 0.000 claims abstract description 11
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 claims abstract description 11
- 238000004519 manufacturing process Methods 0.000 claims abstract description 11
- 150000003856 quaternary ammonium compounds Chemical class 0.000 claims abstract description 11
- 229920002472 Starch Polymers 0.000 claims abstract description 10
- 235000019698 starch Nutrition 0.000 claims abstract description 10
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims abstract description 9
- 102000004169 proteins and genes Human genes 0.000 claims abstract description 9
- 108090000623 proteins and genes Proteins 0.000 claims abstract description 9
- 239000000454 talc Substances 0.000 claims abstract description 9
- 229910052623 talc Inorganic materials 0.000 claims abstract description 9
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims abstract description 6
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims abstract description 6
- 229920003063 hydroxymethyl cellulose Polymers 0.000 claims abstract description 6
- 229920000609 methyl cellulose Polymers 0.000 claims abstract description 6
- 235000010981 methylcellulose Nutrition 0.000 claims abstract description 6
- 235000010443 alginic acid Nutrition 0.000 claims abstract description 5
- 229920000615 alginic acid Polymers 0.000 claims abstract description 5
- 229920000058 polyacrylate Polymers 0.000 claims abstract description 5
- 239000004606 Fillers/Extenders Substances 0.000 claims abstract description 4
- 229920000881 Modified starch Polymers 0.000 claims abstract description 4
- 235000019426 modified starch Nutrition 0.000 claims abstract description 4
- 125000002091 cationic group Chemical group 0.000 claims description 41
- 239000011230 binding agent Substances 0.000 claims description 32
- 229920000642 polymer Polymers 0.000 claims description 26
- 239000007787 solid Substances 0.000 claims description 23
- 235000019422 polyvinyl alcohol Nutrition 0.000 claims description 14
- 229920003118 cationic copolymer Polymers 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- 229920005989 resin Polymers 0.000 claims description 9
- 239000011347 resin Substances 0.000 claims description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 7
- 229920000371 poly(diallyldimethylammonium chloride) polymer Polymers 0.000 claims description 7
- 235000018102 proteins Nutrition 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 6
- BRLQWZUYTZBJKN-UHFFFAOYSA-N Epichlorohydrin Chemical compound ClCC1CO1 BRLQWZUYTZBJKN-UHFFFAOYSA-N 0.000 claims description 5
- 239000007795 chemical reaction product Substances 0.000 claims description 5
- 229920001577 copolymer Polymers 0.000 claims description 5
- 229920000877 Melamine resin Polymers 0.000 claims description 4
- QGBSISYHAICWAH-UHFFFAOYSA-N dicyandiamide Chemical compound NC(N)=NC#N QGBSISYHAICWAH-UHFFFAOYSA-N 0.000 claims description 4
- 238000011065 in-situ storage Methods 0.000 claims description 4
- 230000003287 optical effect Effects 0.000 claims description 4
- 239000002562 thickening agent Substances 0.000 claims description 4
- 239000002174 Styrene-butadiene Substances 0.000 claims description 3
- 150000001252 acrylic acid derivatives Chemical group 0.000 claims description 3
- 125000000217 alkyl group Chemical group 0.000 claims description 3
- MTAZNLWOLGHBHU-UHFFFAOYSA-N butadiene-styrene rubber Chemical compound C=CC=C.C=CC1=CC=CC=C1 MTAZNLWOLGHBHU-UHFFFAOYSA-N 0.000 claims description 3
- 150000002357 guanidines Chemical class 0.000 claims description 3
- PYGSKMBEVAICCR-UHFFFAOYSA-N hexa-1,5-diene Chemical group C=CCCC=C PYGSKMBEVAICCR-UHFFFAOYSA-N 0.000 claims description 3
- 239000000314 lubricant Substances 0.000 claims description 3
- 150000002734 metacrylic acid derivatives Chemical class 0.000 claims description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 3
- 229920002689 polyvinyl acetate Polymers 0.000 claims description 3
- 238000002360 preparation method Methods 0.000 claims description 3
- 239000011115 styrene butadiene Substances 0.000 claims description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 claims description 3
- OMFJJGDERYLMRX-UHFFFAOYSA-N 3-azabicyclo[3.1.1]heptane;hydrochloride Chemical compound Cl.C1C2CC1CNC2 OMFJJGDERYLMRX-UHFFFAOYSA-N 0.000 claims description 2
- 239000007900 aqueous suspension Substances 0.000 claims description 2
- PZNOBXVHZYGUEX-UHFFFAOYSA-N n-prop-2-enylprop-2-en-1-amine;hydrochloride Chemical compound Cl.C=CCNCC=C PZNOBXVHZYGUEX-UHFFFAOYSA-N 0.000 claims description 2
- 230000007935 neutral effect Effects 0.000 claims description 2
- 125000004433 nitrogen atom Chemical group N* 0.000 claims description 2
- 239000011118 polyvinyl acetate Substances 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 claims 2
- 238000005956 quaternization reaction Methods 0.000 claims 1
- 229910021502 aluminium hydroxide Inorganic materials 0.000 abstract 1
- 239000001175 calcium sulphate Substances 0.000 abstract 1
- 235000011132 calcium sulphate Nutrition 0.000 abstract 1
- 239000000470 constituent Substances 0.000 abstract 1
- 229920000193 polymethacrylate Polymers 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 17
- 125000000129 anionic group Chemical group 0.000 description 16
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 10
- 230000002378 acidificating effect Effects 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 238000012545 processing Methods 0.000 description 7
- 239000005995 Aluminium silicate Substances 0.000 description 6
- 235000012211 aluminium silicate Nutrition 0.000 description 6
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 6
- 206010016807 Fluid retention Diseases 0.000 description 5
- 229910000019 calcium carbonate Inorganic materials 0.000 description 5
- 235000010216 calcium carbonate Nutrition 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000003860 storage Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 230000003993 interaction Effects 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 239000008107 starch Substances 0.000 description 4
- 229940095672 calcium sulfate Drugs 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- 239000010440 gypsum Substances 0.000 description 3
- 229910052602 gypsum Inorganic materials 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 229920001131 Pulp (paper) Polymers 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000005189 flocculation Methods 0.000 description 2
- 230000016615 flocculation Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000011164 primary particle Substances 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 229920001353 Dextrin Polymers 0.000 description 1
- 239000004375 Dextrin Substances 0.000 description 1
- 229920002488 Hemicellulose Polymers 0.000 description 1
- 229920000388 Polyphosphate Polymers 0.000 description 1
- PJANXHGTPQOBST-VAWYXSNFSA-N Stilbene Natural products C=1C=CC=CC=1/C=C/C1=CC=CC=C1 PJANXHGTPQOBST-VAWYXSNFSA-N 0.000 description 1
- 125000005396 acrylic acid ester group Chemical group 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- -1 amide fatty acid compounds Chemical class 0.000 description 1
- 229940095564 anhydrous calcium sulfate Drugs 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 229940053200 antiepileptics fatty acid derivative Drugs 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 125000005587 carbonate group Chemical group 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 239000007857 degradation product Substances 0.000 description 1
- 235000019425 dextrin Nutrition 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 150000004683 dihydrates Chemical class 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000003995 emulsifying agent Substances 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000007646 gravure printing Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000003100 immobilizing effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 150000008040 ionic compounds Chemical class 0.000 description 1
- 239000004816 latex Substances 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000001483 mobilizing effect Effects 0.000 description 1
- 239000001205 polyphosphate Substances 0.000 description 1
- 235000011176 polyphosphates Nutrition 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000004537 pulping Methods 0.000 description 1
- 239000013049 sediment Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- PJANXHGTPQOBST-UHFFFAOYSA-N stilbene Chemical class C=1C=CC=CC=1C=CC1=CC=CC=C1 PJANXHGTPQOBST-UHFFFAOYSA-N 0.000 description 1
- 235000021286 stilbenes Nutrition 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 230000009974 thixotropic effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 239000001993 wax Substances 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
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
- D21H19/00—Coated paper; Coating material
- D21H19/36—Coatings with pigments
- D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
Definitions
- the invention relates to cationically adjusted pigment dispersions and coating colors for paper coating.
- the coating pigments used to produce coating colors which are supplied in the dry state, generally have an anionic interfacial charge, and the pigment particles are usually in the form of agglomerates or coarse-particle aggregates, which are disadvantageous both in terms of the processing of the coating color and on the coating quality impact.
- the individual particles should be used as primary particles, i.e. deflocculated, present.
- a combined application of suitable dispersing devices and the use of chemical auxiliaries is required to disperse the agglomerates.
- Optimal dispersion ensures that the attractive forces between the particles are eliminated or counteracted, so that the pigment particles do not re-agglomerate after the dispersion has been produced.
- the most common inorganic and organic dispersants used in the paper industry are almost exclusively polyanionic (e.g. polyphosphates and polyacrylates). These dispersants break up the pigment agglomerates into primary particles, which improves the optical properties of the papers coated with the coating colors, since finer particles give better paper and printing gloss.
- the dispersion also enables pigment slurries and thus coating colors with a high solid are obtained which do not tend to flocculate prematurely even at elevated storage and processing temperatures.
- the anionic dispersants have a number of disadvantages.
- the negative effects of the anionic dispersants can be remedied to a certain extent by reducing the charge with appropriate binders (eg binders rich in carboxyl groups) and by adding low molecular weight cationic auxiliaries, so-called immobilizing agents.
- appropriate binders eg binders rich in carboxyl groups
- low molecular weight cationic auxiliaries so-called immobilizing agents.
- the anionic dispersants interact undesirably with the cationic auxiliaries, which leads to an increase in need for cationic aids.
- the resulting coacervate acts as a contaminant in the papermaking process.
- a coating color in a weakly acidic medium has the advantage that low dispersant amounts are sufficient for pigment dispersion, owing to the good dispersing action of the protons.
- a broader range of binders can be used in the weakly acidic medium, e.g. Amphoteric binders and binders based on proteins, which are also cationic in the weakly acidic range.
- the acidic mode of operation is not possible with CaCO3, due to the decomposition of the carbonate.
- the object of the present invention was to provide cationically adjusted pigment dispersions or coating colors in which pigments are used, their use in the required high concentration because of their high viscosity in aqueous dispersion hitherto was impossible.
- the calcium sulfate can be present as anhydrous calcium sulfate, as a hemihydrate or as a dihydrate.
- the aluminum hydroxide can be present with a cationic surface or, due to grinding aids, with an anionic surface.
- Talc is generally difficult to disperse without wetting agents.
- the pigment components mentioned can also be blended with other pigments, such as kaolin and / or calcium carbonate, the blended pigments also being able to predominate.
- Aqueous dispersions of the starting pigments used according to the invention have very high viscosities even at relatively low solids contents if they are dispersed in a conventional manner.
- Brookfield viscosities of approximately 50% dispersions are between approximately 5000 and 8000 mPa.s (spindle 5 at 50 rpm).
- the pigment dispersions according to the invention are notable for low viscosities, even at high solids contents.
- the pigment dispersions according to the invention can be stored in their cationic form.
- the proportions of expensive transshipment agents can be kept significantly lower.
- the protective colloids also have water-retentive properties and good pigment-binding properties. This water-retentive effect is particularly important for coating color processing on high-speed coating machines, since under the high hydrodynamic loads in coating dosage and leveling, the coating ink loses mobilizing water, binding agents and auxiliaries to the base paper when water retention is poor, which means that strong processing and Final quality problems, as described above, occur.
- the pigment dispersions according to the invention are preferably characterized in that the cationized polymer (c) has been obtained in situ by cationization of the pigment particles (a) coated with the hydrophilic starting polymers.
- the dispersant used as component (b) is preferably an oligomeric or polymeric quaternary ammonium compound. Compared to low molecular weight quaternary ammonium compounds with a low charge density, such compounds have the advantage that the charge reversal takes place more quickly with lower addition amounts and a positive zeta potential is achieved.
- the cationic polymer is preferably obtained by reacting the hydrophilic starting polymers with nitrogen-containing compounds and quaternizing the reaction products.
- a particular advantage of the present invention is that the pigment dispersions can also be used at a weakly acidic pH. This has the advantage that the amount of dispersant (b) can be reduced or coating colors with higher solids contents can be achieved.
- the protective colloids (c) are preferably cationized by reacting the hydrophilic starting polymers with nitrogen-containing compounds and quaternizing the reaction products or by reacting with a cationic polymer or copolymer from the group of the melamine-formaldehyde resins, epichlorohydrin resins, dicyandiamide resins, quaternary acrylates, the polymeric diallyl compounds or of the polymeric guanidine compounds.
- These cationic polymers are also preferably used for the cationic polymer (b).
- the protective colloid (c) can also be cationized from the outset. These compounds include, for example, proteins at a weakly acidic pH.
- the protective colloid is preferably a reaction product of one or more hydrophilic starting polymers with an originally anionic character from the group of Polyacrylates and methacrylates, degraded starches or degraded modified starches, degraded galactomannans, degraded modified galactomannans, methyl celluloses, hydroxymethyl celluloses, carboxymethyl celluloses, degraded alginates and one or more cationic polymers or copolymers from the group of the melamine-formaldehyde resins, epichlorohydrin resins, polymeric epichlorohydrin compounds, polymeric compounds and dicyandiamide resins.
- Polyvinyl alcohols are non-ionic compounds from which cationized protective colloids can also be produced.
- the cationized protective colloid (c) can also be the reaction product of one or more of the above-mentioned substances with originally anionic character and a quaternary ammonium compound of the general formula HN+R3X ⁇ wherein R is an alkyl group with up to 20 carbon atoms and X ⁇ is an anion, in particular a chloride ion.
- the cationic polymer or copolymer (b) used according to the invention is preferably a poly (diallyldimethylammonium chloride) and preferably has a molecular weight corresponding to a viscosity of 500 to 1500 mPa.s (Brookfield viscosity at 15% solids content, 20 rpm and room temperature).
- the cationic polymer or copolymer (b) is preferably a polymeric quaternary ammonium compound according to one of the following structure types: where x is 1 to 3.
- the cationic polymer or copolymer (b) is a poly (diallylammonium chloride) or a poly (3,5-methylene-piperidinium chloride), the nitrogen atoms optionally being substituted by lower alkyl groups.
- the invention further relates to a method for producing a cationically adjusted pigment dispersion, as described above; This process is characterized in that an aqueous suspension of the pigment particles (a) which are optionally coated with the cationized polymer (c) is dispersed with the cationic polymer (b).
- the procedure is such that the pigment particles (a) are coated with the cationized polymer (c) before dispersing until the zeta potential of the dispersion containing the coated pigment particles (a) has a value at the isoelectric point or in has reached the cationic range. It is therefore favorable that the pigment particles are first coated with the cationized protective colloid (c) before they are dispersed with the dispersing and transfer agent (b).
- the pigment component (a) can also be coated with the hydrophilic starting polymer and cationized in situ with the cationic polymer or with the quaternary ammonium compound (b).
- the invention further relates to a coating color for paper coating, a pigment dispersion as described above, and (d) a binder or mixture of binders for connecting the dispersed and optionally coated with the cationized polymer (c) pigment particles (a) to one another and to one another of the paper surface.
- the binder or binder mixture (d) is preferably also cationic or amphoteric in the neutral or alkaline range.
- amphoteric binders are generally only used for coating colors with a weakly acidic pH.
- the amount of the binder (d) can be kept relatively low if the protective colloid (c) is used since it has a co-binder function.
- Preferred synthetic binders (d) are styrene-butadiene or styrene-acrylate copolymers with functional cationic groups and / or cationic polyvinyl acetates, cationic polyvinyl alcohols or their copolymers.
- the binder (d) can be selected from the group of degraded and native galactomannans, starches, methyl celluloses, hydroxymethyl celluloses, carboxymethyl celluloses, alginates, proteins and polyvinyl alcohols and contain cationic groups. Proteins are particularly suitable for the weakly acidic area because of their amphoteric nature they have a cationic charge from the outset. The isoelectric point is included pH 5 to 6. If proteins are used in the alkaline range, they should be slightly cationized (eg by coacervate formation or by real cationization).
- starch If starch is used, it should be cationized for both the acidic and the alkaline range.
- the binders also affect the water retention of the coating color.
- the coating color according to the invention can further contain, as auxiliaries, cationic or nonionic thickeners (e.g. galactomannans or synthetic thickeners), and / or water retention aids.
- the coating color may also contain auxiliaries, such as lubricants (e.g. fatty acid derivatives, waxes or paraffins in emulsion form), optical brighteners (e.g. stilbene derivatives) and / or wet strength agents (e.g. cationic or nonionic resins).
- a preferred coating color contains the components, based on 100 parts by weight of dry pigment (a) in the following parts by weight: Gravure printing Offset / letterpress (c) protective colloids 0.1-6.0 0.1 - 6.0 (b) dispersant 0.0-3.0 0.0 - 3.0 (d) Natural binder 0.0-10.0 1.0 - 20.0 (e) Synthetic binder 1.0-7.0 1.0 - 15.0 (f) Aids as indicated above 0.2-4.0 0.2 - 5.0 (g) wet strength agent 0.0-3.0 0.0 - 5.0
- the coating slip according to the invention is preferably prepared by placing the pigment dispersion according to the invention in a suitable mixing unit, adding the dilution water required for the desired final solids content of the coating slip and, if the mixing intensity is high, adding the natural binder, if appropriate dissolved in a separate operation, and / or subsequently adding the synthetic binder .
- the binders if necessary, the thickener and the water retention aid and then the other auxiliaries, such as lubricants and, if necessary, optical brighteners, and finally the wet strength agent are added.
- the order given has proven particularly useful for the production of an agglomerate-free, easy-to-process coating color.
- the coating color according to the invention has good adhesion to the normally negatively charged paper fiber. This property can be used by using excess coating color, e.g. when changing the paper type, which adds paper pulp as a filler.
- the cationic coating slip according to the invention can safely enter the paper machine cycle since the interaction with the cationic auxiliaries does not occur or wastewater problems are avoided in this way.
- the coating colors according to the invention when added to the paper pulp as fillers, have the side effect that they are also used in the pulping of wood for the production of paper bind resulting anionic degradation products, such as dextrins, lignins, hemicellulose, etc.
- the anionic impurities are adsorbed on the cationic pigment interface and discharged with the paper, so that the wastewater pollution is also lower in this regard.
- This adsorption improves the base paper properties such as opacity, strength, porosity, etc.
- the talc was mixed with water and the PVA solution (hydrophilic starting polymer) and mixed thoroughly. Then the dispersant solution (b) was added, whereby the initially anionic pigment was reloaded.
- the dispersion obtained had the following properties: Ex. 1 Ex. 2 Solids content (% by weight) 58.3 49.8 PH value 8, 2 8.6 Brookfield viscosity at 50 rpm, spindle 5, room temperature mPa.s 880 48 Brookfield viscosity at 100 rpm, spindle 5, room temperature mPa.s 600 60 Zeta potential (mV) +87 +63
- a dispersion with untreated talc had the following properties: Solids content 49.2% by weight pH 8.6 Brookfield viscosity at 50 rpm, spindle 5, room temperature 6600 mPa.s Brookfield viscosity at 100 rpm, spindle 5, room temperature 3900 mPa.s Zeta potential -22 mV
- the dispersions according to the invention therefore had a significantly lower viscosity than the comparative dispersion despite a higher solids content or with practically the same solids content.
- the talc was mixed thoroughly with water. Then the dispersant solution (b) was added, whereby the initially anionic pigment was reloaded.
- the dispersion obtained had the following properties: Solids content 64.4% by weight pH 7.9 Brookfield viscosity at 50 RPM, spindle 4, room temperature 620 mPa.s Brookfield viscosity at 100 RPM, spindle 4, room temperature 510 mPa.s Zeta potential +96 mV
- the gypsum was mixed with water and the phosphated starch solution (hydrophilic starting polymer) and mixed thoroughly. Then the dispersant solution (b) was added, whereby the initially anionic pigment was reloaded.
- the dispersion obtained had the following properties: Solids content 66.6% by weight pH 6.6 Brookfield viscosity at 50 RPM, spindle 5, room temperature 1040 mPa.s Brookfield viscosity at 100 rpm, spindle 5, room temperature 760 mPa.s Zeta potential + 8 mV
- a dispersion with untreated gypsum had the following properties: Solids content 57.0% by weight pH 7.5 Brookfield viscosity at 50 RPM, spindle 6, room temperature 8000 mPa.s Brookfield viscosity at 100 rpm, spindle 6, room temperature 4300 mPa.s Zeta potential -26 mV
- the dispersion according to the invention therefore had a significantly lower viscosity than the comparative dispersion.
- the dispersant solution (b) was added to the PVA solution (hydrophilic starting polymer) and mixed thoroughly, whereby the PVA was cationized. Then the aluminum hydroxide was added.
- the dispersion obtained had the following properties: Solids content 67.4% by weight pH 9.5 Brookfield viscosity at 50 rpm, spindle 5, room temperature 2520 mPa.s Brookfield viscosity at 100 rpm, spindle 5, room temperature 1500 mPa.s Zeta potential +67 mV.
- a dispersion with untreated aluminum hydroxide had the following properties: Solids content 48.7% by weight pH 9.4 Brookfield viscosity at 50 rpm, spindle 5, room temperature 4500 mPa.s Brookfield viscosity at 100 rpm, spindle 5, room temperature 2750 mPa.s Zeta potential +68 mV.
- the dispersion according to the invention therefore had a significantly lower viscosity than the comparison dispersion.
- the reduction in viscosity which apparently has nothing to do with a change in the zeta potential, is probably due to the fact that the agglomerates of the very finely divided pigment components are broken up by the cationized protective colloid.
- the cationic pigment dispersion according to Example 5 was with a cationic kaolin dispersion (extender pigment) of the following composition Water 135 g Kaolin (90% ⁇ 2 ⁇ m) 306 g 21% PVA solution 60 g 45% solution of poly (diallyldimethylammonium chloride) 13 g mixed in such an amount that the weight ratio between aluminum hydroxide and kaolin was 15:85.
- the mixed dispersion obtained had the following properties: Solids content 62.0% by weight pH 7.0 Brookfield viscosity at 50 RPM, spindle 5 room temperature 1920 mPa.s Brookfield viscosity at 100 rpm spindle 5, room temperature 1050 mPa.s Zeta potential + 58 mV.
- the viscosity of the mixed dispersion remained unchanged even after a long storage period.
- Coating colors were prepared with the pigment dispersions according to Examples 1, 4 and 6, the composition of which is given in the table below.
Landscapes
- Paper (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
Abstract
Description
Die Erfindung betrifft kationisch eingestellte Pigmentdispersionen sowie Streichfarben für die Papierbeschichtung.The invention relates to cationically adjusted pigment dispersions and coating colors for paper coating.
Die zur Herstellung von Streichfarben verwendeten Streichpigmente, die im trockenen Zustand angeliefert werden, haben in der Regel eine anionische Grenzflächenladung, und die Pigmentteilchen liegen gewöhnlich als Agglomerate bzw. grobteilige Aggregate vor, die sich sowohl auf die Verarbeitung der Streichfarbe als auch auf die Strichqualität nachteilig auswirken. Für eine optimale Anwendung der Füllstoffe und Streichpigmente bei der Papierherstellung und -veredelung sollen die einzelnen Teilchen als Primärteilchen, d.h. entflockt, vorliegen.The coating pigments used to produce coating colors, which are supplied in the dry state, generally have an anionic interfacial charge, and the pigment particles are usually in the form of agglomerates or coarse-particle aggregates, which are disadvantageous both in terms of the processing of the coating color and on the coating quality impact. For an optimal use of the fillers and coating pigments in paper production and finishing, the individual particles should be used as primary particles, i.e. deflocculated, present.
Zur Dispergierung der Agglomerate ist eine kombinierte Anwendung von geeigneten Dispergiergeräten und der Einsatz von chemischen Hilfsmnitteln erforderlich. Eine optimale Dispergierung stellt sicher, daß die Anziehungskräfte zwischen den Teilchen eliminiert werden oder diesen entgegengewirkt wird, so daß eine Reagglomeration der Pigmentteilchen nach der Herstellung der Dispersion verhindert wird.A combined application of suitable dispersing devices and the use of chemical auxiliaries is required to disperse the agglomerates. Optimal dispersion ensures that the attractive forces between the particles are eliminated or counteracted, so that the pigment particles do not re-agglomerate after the dispersion has been produced.
Die gebräuchlichsten anorganischen und organischen Dispergiermittel, die in der Papierindustries eingesetzt werden, sind fast ausschließlich polyanionisch (z.B. Polyphosphate und Polyacrylate). Durch diese Dispergiermittel werden die Pigmentagglomerate zu Primärteilchen aufgebrochen, wodurch die optischen Eigenschaften der mit den Streichfarben gestrichenen Papiere verbessert werden, da feinere Teilchen einen besseren Papier- und Druckglanz geben. Auch können durch die Dispergierung Pigmentslurries und somit Streichfarben mit einem hohen Fest stoffgehalt erhalten werden, die auch bei erhöhter Lager- und Verarbeitungstemperatur nicht zum vorzeitigen Ausflocken neigen. Die anionischen Dispergiermittel haben jedoch eine Reihe von Nachteilen.The most common inorganic and organic dispersants used in the paper industry are almost exclusively polyanionic (e.g. polyphosphates and polyacrylates). These dispersants break up the pigment agglomerates into primary particles, which improves the optical properties of the papers coated with the coating colors, since finer particles give better paper and printing gloss. The dispersion also enables pigment slurries and thus coating colors with a high solid are obtained which do not tend to flocculate prematurely even at elevated storage and processing temperatures. However, the anionic dispersants have a number of disadvantages.
Bei der Anlagerung von Dispergiermittel an die Pigmentteilchen werden diese in ihrer negativen Ladung verstärkt, wodurch eine Verringerung der Adsorption der üblicherweise verwendeten anionischen Bindemittel (z.B. Stärke, Acrylsäureester, Styrol-Butadien-Latex, Polyvinylacetate, Polyvinylalkohol) an den Pigmentteilchen eintritt. Ferner tritt eine verstärkte Bindemittelwanderung in das Basispapier sowie an die Strichoberfläche auf.When dispersants are added to the pigment particles, their negative charge is increased, which leads to a reduction in the adsorption of the commonly used anionic binders (e.g. starch, acrylic acid ester, styrene-butadiene latex, polyvinyl acetate, polyvinyl alcohol) on the pigment particles. There is also increased binder migration into the base paper and onto the surface of the coating.
Weiterhin ergibt sich eine Erniedrigung des Sedimentvolumens der Streichfarbe und damit geringeres Strichvolumen und eine schlechtere Faserabdeckung.Furthermore, there is a reduction in the sediment volume of the coating color and thus a lower stroke volume and poorer fiber coverage.
Schließlich können Beeinträchtigungen der Produktion durch ungewollte Wechselwirkungen mit kationischen Hilfsmitteln bei der Papierherstellung, insbesondere Ausflockungen, auftreten, wenn die Streichfarben bzw. der gestrichene Ausschuß in den Papierherstellungsprozeß zurückgeführt werden.Finally, adverse effects on production due to unwanted interactions with cationic auxiliaries in papermaking, in particular flocculation, can occur if the coating colors or the coated scrap are returned to the papermaking process.
Die negativen Auswirkungen der anionischen Dispergiermittel können in einem gewissen Grad durch eine Ladungsreduzierung mit entsprechenden Bindemitteln (z.B. carboxylgruppenreiche Bindemittel) und durch den Zusatz von niedermolekularen kationischen Hilfsmitteln, sogenannten Immobilisierungsmitteln, behoben werden. Problematisch ist jedoch immer noch die Produktionsbeeinträchtigung durch verschiedene anionische Dispergiermittel, die über den Streichausschuß bzw. die Streichfarbenrückführung in den Papierherstellungsprozeß gelangen. Die anionischen Dispergiermittel treten in ungewollte Wechsel wirkung mit den kationischen Hilfsmitteln, wodurch ein Mehrver brauch an kationischen Hilfsmitteln erforderlich wird. Außerdem wirkt das entstandene Koazervat (Wechselwirkungsprodukt) als Störstoff bei dem Papierherstellungsprozeß.The negative effects of the anionic dispersants can be remedied to a certain extent by reducing the charge with appropriate binders (eg binders rich in carboxyl groups) and by adding low molecular weight cationic auxiliaries, so-called immobilizing agents. However, the production impairment caused by various anionic dispersants, which enter the paper production process via the coating scrap or the coating color return, is still problematic. The anionic dispersants interact undesirably with the cationic auxiliaries, which leads to an increase in need for cationic aids. In addition, the resulting coacervate (interaction product) acts as a contaminant in the papermaking process.
Zur Behebung dieser Nachteile wurde bereits ein theoretisches Konzept entwickelt, das auf dem Gedanken beruht, Streichfarben für die Papierbeschichtung kationisch einzustellen.To overcome these disadvantages, a theoretical concept has already been developed based on the idea of cationically adjusting coating colors for paper coating.
Dieses Konzept, das in Verbindung mit einigen Vorversuchen im "Wochenblatt für Papierfabrikation" 6 (1984), Seiten 176 bis 183 beschrieben ist, beruht darauf, Pigmente in einem kationischen Dispergiermittel zu dispergieren und auf diese Weise ein kationisiertes Pigment zu erzeugen und die so hergestellte Dispersion mit einem kationischen Bindemittel zu einer Streichfarbe zu verarbeiten. Als kationische Dispergiermittel wurden quaternäre Ammoniumverbindungen, Polyamino-Amid-Fettsäureverbindungen und stark abgebaute niedermolekulare kationische Galaktomannane vorgeschlagen. Als Pigmente, die mit Hilfe dieser Dispergiermittel dispergiert wurden, wurden Kaolin und Calciumcarbonat vorgeschlagen. Die so behandelten Pigmente wurden dann in Form einer wäßrigen Aufschlämmung mit einer gewissen Menge kationischer synthetischer Bindemittel zu einer Streichfarbe verarbeitet.This concept, which is described in connection with some preliminary tests in "Wochenblatt für Papierfabrikation" 6 (1984), pages 176 to 183, is based on dispersing pigments in a cationic dispersant and in this way producing a cationized pigment and the pigment thus prepared Process dispersion with a cationic binder into a coating color. Quaternary ammonium compounds, polyamino amide fatty acid compounds and strongly degraded low molecular weight cationic galactomannans have been proposed as cationic dispersants. Kaolin and calcium carbonate have been proposed as pigments dispersed with the aid of these dispersants. The pigments thus treated were then processed into a coating color in the form of an aqueous slurry with a certain amount of cationic synthetic binders.
Bei diesen Untersuchungen zeigte sich insbesondere, daß nur durch trockenes CaCO₃ die gewünschten Feststoffgehalte - die heute bei der Verarbeitung in der Streichfarbe notwendig sind - erreichbar sind, jedoch nicht mit Kaolin oder anderen Streichpigmenten, und daß auch bei CaCO₃ sehr hohe kationische Dispergiermittelmengen notwendig sind, um diese Feststoffgehalte zu erzielen. Die mit diesen Pigmentdispersionen hergestellten kationisch eingestellten Streichfarben hatten im Vergleich zu anionisch eingestellten Streichfarben ein niedriges Wasserretentionsvermögen und dadurch schlechtere Laufeigenschaften.In these investigations, it was found in particular that the desired solids contents - which are necessary today for processing in the coating slip - can only be achieved by dry CaCO₃, but not with kaolin or other coating pigments, and that very high amounts of cationic dispersants are also necessary with CaCO₃, in order to achieve these solids contents. The cationically adjusted coating colors produced with these pigment dispersions had a low water retention capacity and therefore poorer running properties in comparison with anionically adjusted coating colors.
Aufgrund ihrer hohen Viskositäten zeigten sie bereits mit einer langsam laufenden Laborstreichmaschine Laufschwierigkeiten, die sich bei der Übertragung auf die Praxis noch verstärkten. Auch bei der Slurryaufbereitung und -Lagerung traten infolge der hohen Viskositätswerte Probleme, z.B. eine hohe Scherempfindlichkeit (Reagglomeration) und eine schlechte Siebbarkeit auf. Bei der Lagerung wurde eine deutliche Erhöhung der Viskositätswerte festgestellt. Bei der Streichfarbenverarbeitung wurden eine Streichfarbeneindickung im Arbeitskreislauf sowie hohe thixotrope Fließeigenschaften beobachtet, wodurch aufgrund schlechter Farbrückspieleigenschaften das Papier streifig und die Strichverteilung ungleichmäßig wurde. Ferner traten Endqualitätsprobleme infolge von Strichgewichtsunterschieden über die Papierbahnbreite, schlechtem "coating hold out" und lappiger Papierqualität auf, die bei einem Praxisdruckversuch zu Passerschwierigkeiten und Auslageschwierigkeiten (umgelegte Papierkanten) führten. Auch die Naßrupffestigkeit und Offset-Bedruckbarkeiten waren schlecht.Due to their high viscosities, they already showed one slow-running laboratory coating machine running difficulties, which increased when transferred to practice. Problems with slurry preparation and storage also occurred due to the high viscosity values, for example high sensitivity to shear (reagglomeration) and poor sievability. A significant increase in the viscosity values was observed during storage. A coating thickening in the working cycle and high thixotropic flow properties were observed in the coating color processing, which caused the paper to become streaky and the line distribution to be uneven due to poor color reproduction properties. In addition, end quality problems arose as a result of line weight differences across the paper web width, poor "coating hold out" and lappy paper quality, which led to registration difficulties and delivery difficulties (folded paper edges) in a practical printing test. The wet pick resistance and offset printability were also poor.
Schließlich war es nicht möglich, in schwach saurem Medium zu arbeiten, da die Pigmentdispersion bzw. die Streichfarbe eine Tendenz zum Ausflocken der Pigmentteilchen zeigte.Finally, it was not possible to work in a weakly acidic medium, since the pigment dispersion or the coating color showed a tendency to flocculate the pigment particles.
Eine Streichfarbe in schwach saurem Medium hat aber den Vorteil, daß man mit niedrigen Dispergiermittelmengen bei der Pigmentdispergierung auskommt, aufgrund der guten Dispergierwirkung der Protonen. Weiterhin kann im schwach sauren Medium eine breitere Palette von Bindemitteln eingesetzt werden, wie z.B. amphotere Binder und Bindemittel auf Proteinbasis, die im schwach sauren Bereich ebenfalls kationisch vorliegen. Die saure Fahrweise ist dagegen mit CaCO₃ nicht möglich, aufgrund der Zersetzung des Carbonats.However, a coating color in a weakly acidic medium has the advantage that low dispersant amounts are sufficient for pigment dispersion, owing to the good dispersing action of the protons. Furthermore, a broader range of binders can be used in the weakly acidic medium, e.g. Amphoteric binders and binders based on proteins, which are also cationic in the weakly acidic range. The acidic mode of operation is not possible with CaCO₃, due to the decomposition of the carbonate.
Andere Streichpigmente konnten bisher nicht so kationisch dispergiert werden, daß bei der Streicherei die gewünschten Feststoffgehalte eingestellt werden konnten.Other coating pigments have so far not been able to be dispersed so cationically that the desired solids contents could be set during coating.
Ausgehend von diesen Nachteilen der bekannten kationisch eingestellten Streichfarben, lag der vorliegenden Erfindung die Aufgabe zugrunde, kationisch eingestellte Pigmentdispersionen bzw. Streichfarben zur Verfügung zu stellen, in welchen Pigmente eingesetzt werden, deren Verwendung in der erforderlichen hohen Konzentration wegen ihrer hohen Viskosität in wäßriger Dispersion bisher unmöglich war.Based on these disadvantages of the known cationically adjusted coating colors, the object of the present invention was to provide cationically adjusted pigment dispersions or coating colors in which pigments are used, their use in the required high concentration because of their high viscosity in aqueous dispersion hitherto was impossible.
Diese Aufgabe läßt sich erfindungsgemäß mit Hilfe von Pigmentdispersionen lösen, die gekennzeichnet sind durch
- (a) eine Calciumsulfat, Talkum und/oder Aluminiumhydroxid als Hauptbestandteil oder Verschnittkomponente enthaltende oder daraus bestehende Pigmentkomponente;
- b) ein kationisches Polymer oder eine quaternäre Ammoniumverbindung als Dispergiermittel; und/oder
- c) ein die Teilchen der Pigmentkomponente (a) als Schutzkolloid umhüllendes kationisiertes Polymer, das aus hydrophilen Polyacrylaten oder -methacrylaten, abgebauten Stärken oder abgebauten modifizierten Stärken, abgebauten Galaktomannanen oder abgebauten modifizierten Galaktomannanen, Methylcellulosen, Hydroxymethylcellulosen, Carboxymethylcellulosen, abgebauten Alginaten, Proteinen und/oder Polyvinylalkohol erhalten worden ist.
- (a) a pigment component containing or consisting of calcium sulfate, talc and / or aluminum hydroxide as the main component or extender component;
- b) a cationic polymer or a quaternary ammonium compound as a dispersant; and or
- c) a cationized polymer which envelops the particles of pigment component (a) as a protective colloid and which consists of hydrophilic polyacrylates or methacrylates, degraded starches or degraded modified starches, degraded galactomannans or degraded modified galactomannans, methyl celluloses, hydroxymethyl celluloses, carboxymethyl celluloses, degraded / alginates, proteins or polyvinyl alcohol has been obtained.
Das Calciumsulfat kann erfindungsgemäß als wasserfreies Calciumsulfat, als Halbhydrat oder als Dihydrat vorliegen. Das Aluminiumhydroxid kann mit kationischer Oberfläche oder aber auch, bedingt durch Mahlhilfsmittel, mit anionischer Oberfläche vorliegen. Das Talkum ist im allgemeinen ohne Netzmittel schwer dispergierbar. Die genannten Pigmentkomponenten können erfindungsgemäß auch mit anderen Pigmenten, wie Kaolin und/oder Calciumcarbonat verschnitten sein, wobei die Verschnittpigmente auch überwiegen können.According to the invention, the calcium sulfate can be present as anhydrous calcium sulfate, as a hemihydrate or as a dihydrate. The aluminum hydroxide can be present with a cationic surface or, due to grinding aids, with an anionic surface. Talc is generally difficult to disperse without wetting agents. According to the invention, the pigment components mentioned can also be blended with other pigments, such as kaolin and / or calcium carbonate, the blended pigments also being able to predominate.
Wäßrige Dispersionen der erfindungsgemäß verwendeten Ausgangspigmente haben auch bei verhältnismäßig niedrigen Feststoffgehalten sehr hohe Viskositäten, wenn sie auf herkömmliche Weise dispergiert werden. Beispielsweise liegen die Brookfield-Viskositäten von ca. 50 %igen Dispersionen zwischen etwa 5000 und 8000 mPa.s (Spindel 5 mit 50 Upm).Aqueous dispersions of the starting pigments used according to the invention have very high viscosities even at relatively low solids contents if they are dispersed in a conventional manner. For example, the Brookfield viscosities of approximately 50% dispersions are between approximately 5000 and 8000 mPa.s (spindle 5 at 50 rpm).
Bei Calciumsulfat bewirkt die hohe Löslichkeit (etwa 2 g /Liter bei Raumtempertur) unkontrollierte Flockungen mit anderen Verschnittpigmenten. Außerdem wird die Dispergierwirkung von herkömmlichen Dispergiermitteln aufgehoben.With calcium sulfate, the high solubility (about 2 g / liter at room temperature) causes uncontrolled flocculation with other blend pigments. In addition, the dispersing effect of conventional dispersants is eliminated.
Die erfindungsgemäßen Pigmentdispersionen zeichnen sich durch niedrige Viskositäten auch bei hohen Feststoffgehalten aus.The pigment dispersions according to the invention are notable for low viscosities, even at high solids contents.
Die erfindungsgemäßen Pigmentdispersionen sind in ihrer kationischen Form lagerfähig. Durch die Verwendung der Schutzkolloide (c) können die Anteile an teuren Umladungsmitteln deutlich niedriger gehalten werden. Ferner haben die Schutzkolloide wasserretendierende Eigenschaften sowie gute Pigmentabbindungs-Eigenschaften. Dieser wasserretendierende Effekt ist vor allem bei der Streichfarbenverarbeitung an schnell laufenden Streichmaschinen wichtig, da unter den hohen hydrodynamischen Belastungen bei der Streichfarbendosierung und -Egalisierung die Streichfarbe bei schlechter Wasserretention mobilisierend wirkendes Wasser, Binde- und Hilfsmittel an das Rohpapier verliert, wodurch starke Verarbeitungs- und Endqualitätsprobleme, wie sie vorstehend geschildert wurden, auftreten.The pigment dispersions according to the invention can be stored in their cationic form. By using the protective colloids (c), the proportions of expensive transshipment agents can be kept significantly lower. The protective colloids also have water-retentive properties and good pigment-binding properties. This water-retentive effect is particularly important for coating color processing on high-speed coating machines, since under the high hydrodynamic loads in coating dosage and leveling, the coating ink loses mobilizing water, binding agents and auxiliaries to the base paper when water retention is poor, which means that strong processing and Final quality problems, as described above, occur.
Die erfindunsgemäßen Pigmentdispersionen sind vorzugsweise dadurch gekennzeichnet, daß das kationisierte Polymer (c) in situ durch Kationisierung der mit den hydrophilen Ausgangspolymeren umhüllten Pigmentteilchen (a) erhalten worden ist. Durch diese Maßnahme wird die Herstellung der kationisierten Pigmentdispersionen vereinfacht, weil die externe Kationisierung des Schutzkolloids entfällt.The pigment dispersions according to the invention are preferably characterized in that the cationized polymer (c) has been obtained in situ by cationization of the pigment particles (a) coated with the hydrophilic starting polymers. Through this measure, the production of the cationized Pigment dispersions simplified because there is no external cationization of the protective colloid.
Das als Komponente (b) verwendete Dispergiermittel ist vorzugsweise eine oligomere oder polymere quaternäre Ammoniumverbindung. Derartige Verbindungen haben gegenüber niedermolekularen quaternären Ammoniumverbindungen mit niedriger Ladungsdichte den Vorteil, daß die Umladung bei geringeren Zugabemengen schneller erfolgt und ein positives Zeta-Potential erreicht wird.The dispersant used as component (b) is preferably an oligomeric or polymeric quaternary ammonium compound. Compared to low molecular weight quaternary ammonium compounds with a low charge density, such compounds have the advantage that the charge reversal takes place more quickly with lower addition amounts and a positive zeta potential is achieved.
Das kationische Polymer wird vorzugsweise durch Umsetzung der hydrophilen Ausgangspolymeren mit stickstoffhaltigen Verbindungen und Quaternisierung der Umsetzungsprodukte erhalten.The cationic polymer is preferably obtained by reacting the hydrophilic starting polymers with nitrogen-containing compounds and quaternizing the reaction products.
Ein besonderer Vorteil der vorliegenden Erfindung besteht darin, daß die Pigmentdispersionen auch bei schwach saurem pH-Wert verwendet werden können. Dies hat den Vorteil, daß die Menge des Dispergiermittels (b) herabgesetzt werden kann bzw. Streichfarben mit höheren Feststoffgehalten erzielt werden können.A particular advantage of the present invention is that the pigment dispersions can also be used at a weakly acidic pH. This has the advantage that the amount of dispersant (b) can be reduced or coating colors with higher solids contents can be achieved.
Die Kationisierung der Schutzkolloide (c) erfolgt vorzugsweise durch Umsetzung der hydrophilen Ausgangspolymeren mit stickstoffhaltigen Verbindungen und Quaternisierung der Umsetzungsprodukte bzw. durch Umsetzung mit einem kationischen Polymer oder Copolymer aus der Gruppe der Melamin-Formaldehydharze, Epichlorhydrinharze, Dicyandiamidharze, quaternären Acrylate, der polymeren Diallylverbindungen oder der polymeren Guanidinverbindungen. Diese kationischen Polymeren werden auch bevorzugt für das kationische Polymer (b) eingesetzt.The protective colloids (c) are preferably cationized by reacting the hydrophilic starting polymers with nitrogen-containing compounds and quaternizing the reaction products or by reacting with a cationic polymer or copolymer from the group of the melamine-formaldehyde resins, epichlorohydrin resins, dicyandiamide resins, quaternary acrylates, the polymeric diallyl compounds or of the polymeric guanidine compounds. These cationic polymers are also preferably used for the cationic polymer (b).
Das Schutzkolloid (c) kann auch von vornherein kationisiert sein. Zu diesen Verbindungen zählen z.B. Proteine bei schwach saurem pH-Wert. Vorzugsweise ist das Schutzkolloid jedoch ein Umsetzungsprodukt aus einer oder mehreren hydrophilen Ausgangspolymeren mit ursprünglich anionischem Charakter aus der Gruppe der Polyacrylate und -methacrylate, abgebauten Stärken oder abgebauten modifizierten Stärken, abgebauten Galaktomannanen, abgebauten modifizierten Galaktomannanen, Methylcellulosen, Hydroxymethylcellulosen, Carboxymethylcellulosen, abgebauten Alginaten und einem oder mehreren kationischen Polymeren oder Copolymeren aus der Gruppe der Melamin-Formaldehydharze, Epichlorhydrinharze, polymeren Diallylverbindungen, polymeren Guanidinverbindungen und Dicyandiamidharzen. Bei Polyvinylalkoholen handelt es sich um nichtionogene Verbindungen, aus denen ebenfalls kationisierte Schutzkolloide hergestellt werden können.The protective colloid (c) can also be cationized from the outset. These compounds include, for example, proteins at a weakly acidic pH. However, the protective colloid is preferably a reaction product of one or more hydrophilic starting polymers with an originally anionic character from the group of Polyacrylates and methacrylates, degraded starches or degraded modified starches, degraded galactomannans, degraded modified galactomannans, methyl celluloses, hydroxymethyl celluloses, carboxymethyl celluloses, degraded alginates and one or more cationic polymers or copolymers from the group of the melamine-formaldehyde resins, epichlorohydrin resins, polymeric epichlorohydrin compounds, polymeric compounds and dicyandiamide resins. Polyvinyl alcohols are non-ionic compounds from which cationized protective colloids can also be produced.
Das kationisierte Schutzkolloid (c) kann auch das Umsetzungsprodukt aus einer oder mehreren der vorstehend angegebenen Substanzen mit ursprünglich anionischem Charakter und einer quaternären Ammoniumverbindung der allgemeinen Formel
HN⁺R₃X⁻
worin R eine Alkylgruppe mit bis zu 20 C-Atomen und X⁻ ein Anion, insbesondere ein Chloridion, bedeuten.The cationized protective colloid (c) can also be the reaction product of one or more of the above-mentioned substances with originally anionic character and a quaternary ammonium compound of the general formula
HN⁺R₃X⁻
wherein R is an alkyl group with up to 20 carbon atoms and X⁻ is an anion, in particular a chloride ion.
Das erfindungsgemäß verwendete kationische Polymer bzw. Copolymer (b) ist vorzugsweise ein Poly-(Diallyldimethylammoniumchlorid) und hat vorzugsweise ein Molekulargewicht entsprechend einer Viskosität von 500 bis 1500 mPa.s (Brookfield-Viskosität bei 15 % Feststoffgehalt, 20 UPM und Raumtemperatur).The cationic polymer or copolymer (b) used according to the invention is preferably a poly (diallyldimethylammonium chloride) and preferably has a molecular weight corresponding to a viscosity of 500 to 1500 mPa.s (Brookfield viscosity at 15% solids content, 20 rpm and room temperature).
Vorzugsweise stellt das kationische Polymer bzw. Copolymer (b) eine polymere quaternäre Ammoniumverbindung nach einem der folgenden Strukturtypen dar:
Nach einer besonders bevorzugten Ausführungsform stellt das kationische Polymer oder Copolymer (b) ein Poly-(diallylammoniumchlorid) oder ein Poly-(3,5-methylen-piperidiniumchlorid) dar, wobei die Stickstoffatome gegebenenfalls durch niedere Alkylgruppen substituiert sind.According to a particularly preferred embodiment, the cationic polymer or copolymer (b) is a poly (diallylammonium chloride) or a poly (3,5-methylene-piperidinium chloride), the nitrogen atoms optionally being substituted by lower alkyl groups.
Gegenstand der Erfindung ist ferner ein Verfahren zur Herstellung einer kationisch eingestellten Pigmentdispersion, wie sie vorstehend beschrieben ist; dieses Verfahren ist dadurch gekennzeichnet, daß man eine wäßrige Suspension der gegebenenfalls mit dem kationisierten Polymer (c) umhüllten Pigmentteilchen (a) mit dem kationischen Polymer (b) dispergiert.The invention further relates to a method for producing a cationically adjusted pigment dispersion, as described above; This process is characterized in that an aqueous suspension of the pigment particles (a) which are optionally coated with the cationized polymer (c) is dispersed with the cationic polymer (b).
Vorzugsweise geht man hierbei so vor, daß man die Pigmentteilchen (a) vor dem Dispergieren so weit mit dem kationisierten Polymer (c) umhüllt, bis das Zeta-Potential der die umhüllten Pigmentteilchen (a) enthaltenden Dispersion einen Wert am isoelektrischen Punkt bzw. im kationischen Bereich erreicht hat. Es ist also günstig, daß die Pigmentteilchen zunächst mit dem kationisierten Schutzkolloid (c) umhüllt werden, bevor sie mit dem Dispergier- und Umladungsmittel (b) dispergiert werden.Preferably, the procedure is such that the pigment particles (a) are coated with the cationized polymer (c) before dispersing until the zeta potential of the dispersion containing the coated pigment particles (a) has a value at the isoelectric point or in has reached the cationic range. It is therefore favorable that the pigment particles are first coated with the cationized protective colloid (c) before they are dispersed with the dispersing and transfer agent (b).
Man kann aber auch die Pigmentkomponente (a) mit dem hydrophilen Ausgangspolymer umhüllen und in situ mit dem kationischen Polymer oder mit der quaternären Ammoniumverbindung (b) kationisieren.However, the pigment component (a) can also be coated with the hydrophilic starting polymer and cationized in situ with the cationic polymer or with the quaternary ammonium compound (b).
Gegenstand der Erfindung ist ferner eine Streichfarbe für die Papierbeschichtung, die eine Pigmentdispersion, wie sie vorstehend beschrieben ist, und (d) ein Bindemittel oder Bindemittelgemisch zum Verbinden der dispergierten und gegebenenfalls mit dem kationisierten Polymer (c) umhüllten Pigmentteilchen (a) untereinander und mit der Papieroberfläche enthält. Vorzugsweise ist das Bindemittel bzw. Bindemittelgemisch (d) auch im neutralen bzw. alkalischen Bereich kationisch oder amphoter. Amphotere Bindemittel werden im allgemeinen jedoch nur bei Streichfarben mit schwach saurem pH-Wert verwendet.The invention further relates to a coating color for paper coating, a pigment dispersion as described above, and (d) a binder or mixture of binders for connecting the dispersed and optionally coated with the cationized polymer (c) pigment particles (a) to one another and to one another of the paper surface. The binder or binder mixture (d) is preferably also cationic or amphoteric in the neutral or alkaline range. However, amphoteric binders are generally only used for coating colors with a weakly acidic pH.
Erfindungsgemäß kann die Menge des Bindemittels (d) relativ niedrig gehalten werden, wenn das Schutzkolloid (c) verwendet wird da dieses eine Co-Bindemittelfunktion hat.According to the invention, the amount of the binder (d) can be kept relatively low if the protective colloid (c) is used since it has a co-binder function.
Bevorzugte synthetische Bindemittel (d) sind Styrol-Butadien-oder Styrol-Acrylat-Copolymere mit funktionellen kationischen Gruppen und/oder kationische Polyvinylacetate, kationische Polyvinylalkohole bzw. deren Copolymere.Preferred synthetic binders (d) are styrene-butadiene or styrene-acrylate copolymers with functional cationic groups and / or cationic polyvinyl acetates, cationic polyvinyl alcohols or their copolymers.
Ferner kann das Bindemittel (d) aus der Gruppe der abgebauten und nativen Galaktomannane, Stärken, Methylcellulosen, Hydroxymethylcellulosen, Carboxymethylcellulosen, Alginate, Proteine und Polyvinylalkohole ausgewählt sein und kationische Gruppen enthalten. Proteine sind besonders für den schwach sauren Bereich geeignet, da sie wegen ihrer amphoteren Natur von vornherein eine kationische Ladung haben. Der isoelektrische Punkt liegt bei einem pH-Wert von 5 bis 6. Werden Proteine im alkalischen Bereich verwendet, so sollten sie leicht kationisiert sein (z.B. durch Koazervatbildung oder durch echte Kationisierung).Furthermore, the binder (d) can be selected from the group of degraded and native galactomannans, starches, methyl celluloses, hydroxymethyl celluloses, carboxymethyl celluloses, alginates, proteins and polyvinyl alcohols and contain cationic groups. Proteins are particularly suitable for the weakly acidic area because of their amphoteric nature they have a cationic charge from the outset. The isoelectric point is included pH 5 to 6. If proteins are used in the alkaline range, they should be slightly cationized (eg by coacervate formation or by real cationization).
Bei Verwendung von Stärke soll diese sowohl für den sauren als auch für den alkalischen Bereich kationisiert vorliegen. Die Bindemittel beeinflussen auch die Wasserretention der Streichfarbe.If starch is used, it should be cationized for both the acidic and the alkaline range. The binders also affect the water retention of the coating color.
Es hat sich gezeigt, daß synthetische Bindemittel, die nur über das Emulgatorsystem kationisiert waren, also in ihrem eigenen Gerüst noch anionisch waren, für die genannten kationischen Streichfarben weniger geeignet sind.It has been shown that synthetic binders which were only cationized via the emulsifier system, ie were still anionic in their own framework, are less suitable for the cationic coating colors mentioned.
Die erfindungsgemäße Streichfarbe kann ferner als Hilfsmittel kationische oder nicht ionogene Verdickungsmittel (z.B. Galaktomannane oder synthetische Verdickungsmittel), und/oder Wasserretentionshilfs mittel enthalten. Ferner kann die Streichfarbe Hilfsmittel, wie Gleitmittel (z.B. Fettsäurederivate, Wachse oder Paraffine in Emulsionsform), optische Aufheller (z.B. Stilben-Derivate) und/oder Naßverfestigungsmittel (z.B. kationische oder nichtionogene Harze) enthalten.The coating color according to the invention can further contain, as auxiliaries, cationic or nonionic thickeners (e.g. galactomannans or synthetic thickeners), and / or water retention aids. The coating color may also contain auxiliaries, such as lubricants (e.g. fatty acid derivatives, waxes or paraffins in emulsion form), optical brighteners (e.g. stilbene derivatives) and / or wet strength agents (e.g. cationic or nonionic resins).
Eine bevorzugte Streichfarbe enthält die Komponenten, bezogen auf 100 Gewichtsteile trockenes Pigment (a) in folgenden Gewichtsanteilen:
Die erfindungsgemäße Streichfarbe wird vorzugsweise dadurch hergestellt, daß man die erfindungsgemäße Pigmentdispersion in einem geeigneten Mischaggregat vorlegt, das für den gewünschten Endfeststoffgehalt der Streichfarbe erforderliche Verdünnungswasser zusetzt und bei hoher Mischintensität das gegebenenfalls in einem separaten Arbeitsgang gelöste natürliche Bindemittel und/oder anschließend das synthetische Bindemittel zusetzt. Nach der Einarbeitung der Bindemittel werden, falls erforderlich, das Verdickungsmittel und das Wasserretentionshilfsmittel und anschließend die übrigen Hilfsmittel, wie Gleitmittel und im Bedarfsfall optische Aufheller und am Schluß das Naßverfestigungsmittel zugesetzt. Die angegebene Reihenfolge hat sich für die Herstellung einer agglomeratefreien, gut verarbeitbaren Streichfarbe besonders bewährt.The coating slip according to the invention is preferably prepared by placing the pigment dispersion according to the invention in a suitable mixing unit, adding the dilution water required for the desired final solids content of the coating slip and, if the mixing intensity is high, adding the natural binder, if appropriate dissolved in a separate operation, and / or subsequently adding the synthetic binder . After incorporation of the binders, if necessary, the thickener and the water retention aid and then the other auxiliaries, such as lubricants and, if necessary, optical brighteners, and finally the wet strength agent are added. The order given has proven particularly useful for the production of an agglomerate-free, easy-to-process coating color.
Die erfindungsgemäße Streichfarbe hat eine gute Haftung an der normalerweise negativ geladenen Papierfaser. Diese Eigenschaft kann man sich zunutze machen, indem man überschüssige Streichfarbe, z.B. bei einem Papiersortenwechsel, der Papiermasse als Füllstoff zusetzt. Im Gegensatz zu einer anionischen Streichfarbe, die mit kationischen Hilfsmitteln ungewollte Wechselwirkungen eingeht, kann die erfindungsgemäße kationische Streichfarbe bedenkenlos in den Papiermaschinenkreislauf gelangen, da die Wechselwirkung mit den kationischen Hilfsmitteln ausbleibt bzw. über diesen Weg Abwasserprobleme vermieden werden.The coating color according to the invention has good adhesion to the normally negatively charged paper fiber. This property can be used by using excess coating color, e.g. when changing the paper type, which adds paper pulp as a filler. In contrast to an anionic coating slip which enters into undesired interactions with cationic auxiliaries, the cationic coating slip according to the invention can safely enter the paper machine cycle since the interaction with the cationic auxiliaries does not occur or wastewater problems are avoided in this way.
Ferner haben die erfindungsgemäßen Streichfarben, wenn sie der Papiermasse als Füllstoffe zugesetzt werden, die Nebenwirkung, daß sie auch die beim Holzaufschluß zur Herstellung von Papier anfallenden anionischen Abbauprodukte, wie Dextrine, Lignine, Hemicellulose usw. binden. Die anionischen Störstoffe werden an der kationisch eingestellten Pigmentgrenzfläche adsorbiert und mit dem Papier ausgetragen, so daß die Abwasserbelastung auch in dieser Hinsicht geringer wird.Furthermore, the coating colors according to the invention, when added to the paper pulp as fillers, have the side effect that they are also used in the pulping of wood for the production of paper bind resulting anionic degradation products, such as dextrins, lignins, hemicellulose, etc. The anionic impurities are adsorbed on the cationic pigment interface and discharged with the paper, so that the wastewater pollution is also lower in this regard.
Durch diese Adsorption werden die Rohpapiereigenschaften, wie Opazität, Festigkeit, Porosität usw. verbessert.This adsorption improves the base paper properties such as opacity, strength, porosity, etc.
Die Erfindung ist durch die nachstehenden Beispiele erläutert:The invention is illustrated by the following examples:
Kationische Pigmentdispersionen aus den nachstehend angegebenen Komponenten
Das Talkum wurde mit Wasser und der PVA-Lösung (hydrophiles Ausgangspolymer) versetzt und gründlich vermischt. Dann wurde die Dispergiermittellösung (b) zugesetzt, wodurch das zunächst anionische Pigment umgeladen wurde. Die erhaltene Dispersion hatte folgende Eigenschaften:
Zum Vergleich hatte eine Dispersion mit unbehandeltem Talkum folgende Eigenschaften:
Feststoffgehalt 49,2 Gew.-%
pH-Wert 8,6
Brookfield-Viskosität bei 50 UPM, Spindel 5, Raumtemperatur 6600 mPa.s
Brookfield-Viskosität bei 100 UPM, Spindel 5, Raumtemperatur 3900 mPa.s
Zeta-Potential -22 mVFor comparison, a dispersion with untreated talc had the following properties:
Solids content 49.2% by weight
pH 8.6
Brookfield viscosity at 50 rpm, spindle 5, room temperature 6600 mPa.s
Brookfield viscosity at 100 rpm, spindle 5, room temperature 3900 mPa.s
Zeta potential -22 mV
Die erfindungsgemäßen Dispersionen hatten also trotz höherem Feststoffgehalt bzw. bei praktisch gleichem Feststoffgehalt eine wesentlich niedrigere Viskosität als die Vergleichsdispersion.The dispersions according to the invention therefore had a significantly lower viscosity than the comparative dispersion despite a higher solids content or with practically the same solids content.
Eine kationische Pigmentdispersion aus den nachstehend angegebenen Komponenten
Wasser für 64,4%ige Dispersion 830 g
Talkum (60 % < 2µm als Pigment (a)) 2181 g
45%ige Lösung von Poly-(Diallyldimethylammoniumchlorid) als Dispergiermittel (b) 105 g
wurde wie folgt hergestellt:A cationic pigment dispersion from the components listed below
Water for 64.4% dispersion 830 g
Talc (60% <2 µm as pigment (a)) 2181 g
45% solution of poly (diallyldimethylammonium chloride) as dispersant (b) 105 g
was made as follows:
Das Talkum wurde mit Wasser gründlich vermischt. Dann wurde die Dispergiermittellösung (b) zugesetzt, wodurch das zunächst anionische Pigment umgeladen wurde.The talc was mixed thoroughly with water. Then the dispersant solution (b) was added, whereby the initially anionic pigment was reloaded.
Die erhaltene Dispersion hatte folgende Eigenschaften:
Feststoffgehalt 64,4 Gew.-%
pH-Wert 7,9
Brookfield-Viskosität bei 50 UPM, Spindel 4, Raumtemperatur 620 mPa.s
Brookfield-Viskosität bei 100 UPM, Spindel 4, Raumtemperatur 510 mPa.s
Zeta-potential +96 mVThe dispersion obtained had the following properties:
Solids content 64.4% by weight
pH 7.9
Brookfield viscosity at 50 RPM, spindle 4, room temperature 620 mPa.s
Brookfield viscosity at 100 RPM, spindle 4, room temperature 510 mPa.s
Zeta potential +96 mV
Dieses Beispiel zeigt, daß auch ohne Verwendung eines Schutzkolloids, d.h. nur mit der Dispergiermittellösung (b) eine starke Erniedrigung der Viskosität erhalten werden konnte.This example shows that even without using a protective colloid, i.e. only with the dispersant solution (b) a sharp reduction in viscosity could be obtained.
Eine kationische Pigmentdispersion aus den nachstehend angegebenen Komponenten
Wasser für 66,6%ige Dispersion 180 g
29%ige phosphatierte Stärkelösung 138 g
Gips (55 % < 2 µm als Pigment (a)) 2667 g
45%ige Lösung von Poly-(Diallyldimethylammoniumchlorid) als Dispergiermittel (b) 44 g
wurde wie folgt herstellt.A cationic pigment dispersion from the components listed below
Water for 66.6% dispersion 180 g
29% phosphated starch solution 138 g
Gypsum (55% <2 µm as pigment (a)) 2667 g
45% solution of poly (diallyldimethylammonium chloride) as dispersant (b) 44 g
was made as follows.
Der Gips wurde mit Wasser und der phosphatierten Stärkelösung (hydrophiles Ausgangspolymer) versetzt und gründlich vermischt. Dann wurde die Dispergiermittellösung (b) zugesetzt, wodurch das zunächst anionische Pigment umgeladen wurde.The gypsum was mixed with water and the phosphated starch solution (hydrophilic starting polymer) and mixed thoroughly. Then the dispersant solution (b) was added, whereby the initially anionic pigment was reloaded.
Die erhaltene Dispersion hatte folgende Eigenschaften:
Feststoffgehalt 66,6 Gew.-%
pH-Wert 6,6
Brookfield-Viskosität bei 50 UPM, Spindel 5, Raumtemperatur 1040 mPa.s
Brookfield-Viskosität bei 100 UPM, Spindel 5, Raumtemperatur 760 mPa.s
Zeta-Potential + 8 mVThe dispersion obtained had the following properties:
Solids content 66.6% by weight
pH 6.6
Brookfield viscosity at 50 RPM, spindle 5, room temperature 1040 mPa.s
Brookfield viscosity at 100 rpm, spindle 5, room temperature 760 mPa.s
Zeta potential + 8 mV
Zum Vergleich hatte eine Dispersion mit unbehandeltem Gips folgende Eigenschaften:
Feststoffgehalt 57,0 Gew.-%
pH-Wert 7,5
Brookfield-Viskosität bei 50 UPM, Spindel 6, Raumtemperatur 8000 mPa.s
Brookfield-Viskosität bei 100 UPM, Spindel 6, Raumtemperatur 4300 mPa.s
Zeta-Potential -26 mVFor comparison, a dispersion with untreated gypsum had the following properties:
Solids content 57.0% by weight
pH 7.5
Brookfield viscosity at 50 RPM, spindle 6, room temperature 8000 mPa.s
Brookfield viscosity at 100 rpm, spindle 6, room temperature 4300 mPa.s
Zeta potential -26 mV
Die erfindungsgemäße Dispersion hatte also trotz höherem Feststoffgehalt eine wesentlich niedrigere Viskosität als die Vergleichsdispersion.Despite the higher solids content, the dispersion according to the invention therefore had a significantly lower viscosity than the comparative dispersion.
Eine kationische Pigmentdispersion aus den nachstehend angegebenen Komponenten
Wasser für 67,4%ige Dispersion 880 g
22%ige PVA-Lösung 91 g
Aluminiumhydroxid (80 % <0,5 µm als Pigment (a)) 2000 g
45%ige Lösung von Poly-(Diallyldimethylammoniumchlorid) als Dispergiermittel (b) 10 g
wurde wie folgt hergestellt:A cationic pigment dispersion from the components listed below
Water for 67.4% dispersion 880 g
22% PVA solution 91 g
Aluminum hydroxide (80% <0.5 µm as pigment (a)) 2000 g
45% solution of poly (diallyldimethylammonium chloride) as dispersant (b) 10 g
was made as follows:
Die PVA-Lösung (hydrophiles Ausgangspolymer) wurde mit der Dispergiermittellösung (b) versetzt und gründlich vermischt, wodurch das PVA kationisiert wurde. Dann wurde das Aluminiumhydroxid zugesetzt.The dispersant solution (b) was added to the PVA solution (hydrophilic starting polymer) and mixed thoroughly, whereby the PVA was cationized. Then the aluminum hydroxide was added.
Die erhaltene Dispersion hatte folgende Eigenschaften:
Feststoffgehalt 67,4 Gew.-%
pH-Wert 9,5
Brookfield-Viskosität bei 50 UPM, Spindel 5, Raumtemperatur 2520 mPa.s
Brookfield-Viskosität bei 100 UPM, Spindel 5, Raumtemperatur 1500 mPa.s
Zeta-Potential +67 mV.The dispersion obtained had the following properties:
Solids content 67.4% by weight
pH 9.5
Brookfield viscosity at 50 rpm, spindle 5, room temperature 2520 mPa.s
Brookfield viscosity at 100 rpm, spindle 5, room temperature 1500 mPa.s
Zeta potential +67 mV.
Zum Vergleich hatte eine Dispersion mit unbehandeltem Aluminiumhydroxid folgende Eigenschaften:
Feststoffgehalt 48,7 Gew.-%
pH-Wert 9,4
Brookfield-Viskosität bei 50 UPM, Spindel 5, Raumtemperatur 4500 mPa.s
Brookfield-Viskosität bei 100 UPM, Spindel 5, Raumtemperatur 2750 mPa.s
Zeta-Potential +68 mV.For comparison, a dispersion with untreated aluminum hydroxide had the following properties:
Solids content 48.7% by weight
pH 9.4
Brookfield viscosity at 50 rpm, spindle 5, room temperature 4500 mPa.s
Brookfield viscosity at 100 rpm, spindle 5, room temperature 2750 mPa.s
Zeta potential +68 mV.
Die erfindungsgemäße Dispersion hatte also trotz höherem Feststoffgehalt eine wesentliche niedrigere Viskosität als die Vergleichsdispersion. Die Viskositätserniedrigung, die offenbar nichts mit einer Änderung des Zeta-Potentials zu tun hat, ist vermutlich dadurch bedingt, daß durch das kationisierte Schutzkolloid die Agglomerate der sehr feinteiligen Pigmentkomponete aufgebrochen werden.In spite of the higher solids content, the dispersion according to the invention therefore had a significantly lower viscosity than the comparison dispersion. The reduction in viscosity, which apparently has nothing to do with a change in the zeta potential, is probably due to the fact that the agglomerates of the very finely divided pigment components are broken up by the cationized protective colloid.
Die kationisische Pigmentdispersion nach Beispiel 5 wurde mit einer kationischen Kaolindispersion (Verschnittpigment) folgender Zusammensetzung
Wasser 135 g
Kaolin (90% < 2 µm) 306 g
21%ige PVA-Lösung 60 g
45%ige Lösung vom Poly-(Diallyldimethylammoniumchlorid) 13 g
in einer solchen Menge vermischt, daß das Gewichtsverhältnis zwischen Aluminiumhydroxid und Kaolin 15 : 85 betrug.The cationic pigment dispersion according to Example 5 was with a cationic kaolin dispersion (extender pigment) of the following composition
Water 135 g
Kaolin (90% <2 µm) 306 g
21% PVA solution 60 g
45% solution of poly (diallyldimethylammonium chloride) 13 g
mixed in such an amount that the weight ratio between aluminum hydroxide and kaolin was 15:85.
Die erhaltene Mischdispersion hatte folgende Eigenschaften:
Feststoffgehalt 62,0 Gew.-%
pH-Wert 7,0
Brookfield-Viskosität bei 50 UPM, Spindel 5 Raumtemperatur 1920 mPa.s
Brookfield-Viskosität bei 100 UPM Spindel 5, Raumtemperatur 1050 mPa.s
Zeta-Potential + 58 mV.The mixed dispersion obtained had the following properties:
Solids content 62.0% by weight
pH 7.0
Brookfield viscosity at 50 RPM, spindle 5 room temperature 1920 mPa.s
Brookfield viscosity at 100 rpm spindle 5, room temperature 1050 mPa.s
Zeta potential + 58 mV.
Die Viskosität der Mischdispersion blieb auch nach längerer Lagerzeit unverändert.The viscosity of the mixed dispersion remained unchanged even after a long storage period.
Herstellung kationischer Streichfarben:Production of cationic coating colors:
Mit den Pigmentdispersionen nach den Beispielen 1, 4 und 6 wurden Streichfarben hergestellt, deren Zusammensetzung in der nachstehenden Tabelle angegeben ist.
Aus den Pigmnentdispersionen nach den Vergleichsbeispielen 1, 4 und 5 konnten keine Streichfarben mit ausreichend hohen Feststoffgehalten bei verarbeitbaren Viskositäten hergestellt werden. Nach kurzer Lagerzeit dickten die Streichfarben so stark ein, daß keine Streichversuche mehr möglich waren. Die erfindungsgemäßen Streichfarben dickten auch nach längerer Verarbeitung nicht ein. Papiere mit den erfindungsgemäßen Streichfarben zeichneten sich durch eine gleichmäßige geschlossene Oberfläche, eine gute Faserabdeckung, eine hohe Opazität und ein hohes Strichvolumen aus. Die Offset-Bedruckbarkeit und die Tiefdruck-Bedruckbarkeit der erhaltenen Papiere waren gut.No coating colors with sufficiently high solids contents and processable viscosities could be produced from the pigment dispersions according to Comparative Examples 1, 4 and 5. After a short period of storage, the coating colors thickened so much that no further coating attempts were possible. The coating colors according to the invention did not thicken even after prolonged processing. Papers with the coating colors according to the invention were distinguished by a uniform, closed surface, good fiber coverage, high opacity and a high stroke volume. The offset printability and the rotogravure printability of the papers obtained were good.
Claims (19)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19873730833 DE3730833A1 (en) | 1987-09-14 | 1987-09-14 | CATIONICALLY PIGMENT DISPERSION AND STRIP COLOR |
DE3730833 | 1987-09-14 |
Publications (2)
Publication Number | Publication Date |
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EP0307795A2 true EP0307795A2 (en) | 1989-03-22 |
EP0307795A3 EP0307795A3 (en) | 1989-12-13 |
Family
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Application Number | Title | Priority Date | Filing Date |
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EP88114669A Withdrawn EP0307795A3 (en) | 1987-09-14 | 1988-09-08 | Cationically modified pigmentary dispersion and coating colour |
Country Status (4)
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EP (1) | EP0307795A3 (en) |
JP (1) | JPH0197296A (en) |
DE (1) | DE3730833A1 (en) |
FI (1) | FI884222A (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0401790A2 (en) * | 1989-06-06 | 1990-12-12 | Plüss-Staufer AG | Highly concentrated aqueous slurry of minerals and/or fillers and/or pigments |
EP0509365A2 (en) * | 1991-04-16 | 1992-10-21 | Nittetsu Mining Co., Ltd. | Filler for degradable plastics and process for producing the same |
WO1993011300A1 (en) * | 1991-11-25 | 1993-06-10 | Raision Tehtaat Oy Ab | A method for reducing the permeability of paper and board and a substance for the method |
US5384013A (en) * | 1988-01-22 | 1995-01-24 | Ecc International Limited | Cationic pigment-containing paper coating composition |
FR2730224A1 (en) * | 1995-02-02 | 1996-08-09 | Sueddeutsche Kalkstickstoff | SUSPENSIONS OF CATIONIC DISPERSANT ALUMINUM HYDROXIDE |
WO2002095130A1 (en) * | 2001-05-18 | 2002-11-28 | Sun Chemical Corporation | Method of coloring cellulosic materials using a cationic pigment dispersion |
WO2006029883A2 (en) * | 2004-09-17 | 2006-03-23 | Basf Aktiengesellschaft | Method for producing single or multiply coated substrates with the aid of a coloured coating composition comprising a binding agent for adhesion |
CN105176142A (en) * | 2015-08-31 | 2015-12-23 | 山东林嘉新材料科技有限公司 | Modification method for aluminum hydroxide |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4970467B2 (en) * | 2007-01-26 | 2012-07-04 | ハリマ化成株式会社 | Papermaking additives and fillers |
CA2697109C (en) * | 2007-07-26 | 2012-12-04 | Harima Chemicals, Inc. | Papermaking internal sizing agent and use thereof |
BRPI1006241A2 (en) * | 2009-03-17 | 2017-03-28 | Styron Europe Gmbh | process for making paper and paper product |
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CH642980A5 (en) * | 1979-12-21 | 1984-05-15 | Hercules Inc | Process for the preparation of a copolymer latex |
JPS60215895A (en) * | 1984-04-10 | 1985-10-29 | 住友ノ−ガタツク株式会社 | Paper coating composition |
-
1987
- 1987-09-14 DE DE19873730833 patent/DE3730833A1/en not_active Withdrawn
-
1988
- 1988-09-08 EP EP88114669A patent/EP0307795A3/en not_active Withdrawn
- 1988-09-14 JP JP63228885A patent/JPH0197296A/en active Pending
- 1988-09-14 FI FI884222A patent/FI884222A/en not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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CH642980A5 (en) * | 1979-12-21 | 1984-05-15 | Hercules Inc | Process for the preparation of a copolymer latex |
JPS60215895A (en) * | 1984-04-10 | 1985-10-29 | 住友ノ−ガタツク株式会社 | Paper coating composition |
Non-Patent Citations (1)
Title |
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ABSTRACT BULLETIN OF THE INSTITUTE OF PAPER CHEMISTRY, Band 57, Nr. 4, Oktober 1986, Seite 610, Zusammenfassung Nr. 5438, Appleton, Wisconsin, US; & JP-A-85 215 895 (SUMITOMO NAUGATUCK CO. LTD) 29-10-1985 * |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5384013A (en) * | 1988-01-22 | 1995-01-24 | Ecc International Limited | Cationic pigment-containing paper coating composition |
AU633321B2 (en) * | 1989-06-06 | 1993-01-28 | Pluss-Staufer Ag | Highly concentrated aqueous suspension of minerals and/or fillers and/or pigments |
EP0401790A3 (en) * | 1989-06-06 | 1991-08-21 | Plüss-Staufer AG | Highly concentrated aqueous slurry of minerals and/or fillers and/or pigments |
EP0401790A2 (en) * | 1989-06-06 | 1990-12-12 | Plüss-Staufer AG | Highly concentrated aqueous slurry of minerals and/or fillers and/or pigments |
EP0509365A2 (en) * | 1991-04-16 | 1992-10-21 | Nittetsu Mining Co., Ltd. | Filler for degradable plastics and process for producing the same |
EP0509365A3 (en) * | 1991-04-16 | 1993-08-04 | Nittetsu Mining Co., Ltd. | Filler for degradable plastics and process for producing the same |
GB2287420B (en) * | 1991-11-25 | 1996-06-05 | Raision Tehtaat Oy Ab | Reducing permeability of paper and board |
GB2287420A (en) * | 1991-11-25 | 1995-09-20 | Raision Tehtaat Oy Ab | Reducing permeability of paper and board |
WO1993011300A1 (en) * | 1991-11-25 | 1993-06-10 | Raision Tehtaat Oy Ab | A method for reducing the permeability of paper and board and a substance for the method |
FR2730224A1 (en) * | 1995-02-02 | 1996-08-09 | Sueddeutsche Kalkstickstoff | SUSPENSIONS OF CATIONIC DISPERSANT ALUMINUM HYDROXIDE |
WO2002095130A1 (en) * | 2001-05-18 | 2002-11-28 | Sun Chemical Corporation | Method of coloring cellulosic materials using a cationic pigment dispersion |
WO2006029883A2 (en) * | 2004-09-17 | 2006-03-23 | Basf Aktiengesellschaft | Method for producing single or multiply coated substrates with the aid of a coloured coating composition comprising a binding agent for adhesion |
WO2006029883A3 (en) * | 2004-09-17 | 2007-02-15 | Basf Ag | Method for producing single or multiply coated substrates with the aid of a coloured coating composition comprising a binding agent for adhesion |
CN105176142A (en) * | 2015-08-31 | 2015-12-23 | 山东林嘉新材料科技有限公司 | Modification method for aluminum hydroxide |
CN105176142B (en) * | 2015-08-31 | 2018-03-30 | 山东林嘉新材料科技有限公司 | A kind of method of modifying of aluminium hydroxide |
Also Published As
Publication number | Publication date |
---|---|
FI884222A0 (en) | 1988-09-14 |
JPH0197296A (en) | 1989-04-14 |
FI884222A (en) | 1989-03-15 |
EP0307795A3 (en) | 1989-12-13 |
DE3730833A1 (en) | 1989-03-23 |
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