CN1289356A

CN1289356A - Composition and method of making improved high bulking clays

Info

Publication number: CN1289356A
Application number: CN99802385A
Authority: CN
Inventors: J·亨; J·P·伯布里克
Original assignee: Engelhard Corp
Current assignee: BASF Catalysts LLC
Priority date: 1998-11-03
Filing date: 1999-10-27
Publication date: 2001-03-28
Also published as: KR20010033837A; BR9906718A; AU1326100A; CA2316998A1; EP1042409A1; JP2002528624A; WO2000026306A1; ID26566A

Abstract

A delaminated and deslimed pigment is bulked with small and controlled quantities of a cationic polyelectrolyte such as polydimethyldiallyl ammonium chloride to produce a highly bulked pigment ideal for improving printability, opacity and sheet gloss in coated paper applications, particularly for LWC rotogravure papers.

Description

Make the composition and the method for improved high bulking clays

Background of the present invention

1.1 the field of the invention

The present invention relates to produce the composition and the method for high bulking clays pigment.This pigment is proved to be and can significantly improves paper performance such as printing in paper coating is used, and opacity and sheet material gloss are especially opened for rotogravure paper and comprised for lightweight coating (LWC) and ultralight matter coating (ULWC) paper.This pigment also can be as the filler of paper web.

1.2 correlation technique

The narrowing relatively of size-grade distribution that has realized that the kaolin particle of mechanical system leafing and non-leafing makes this pigment that improved opacity is provided in applying filler.When being used to make the lightweight overlay paper of using for rotogravure printing, it is ideal (referring to the U.S. 4,948,664, people such as Brociner) especially that this pigment is disclosed.Well-known is to remove the ultrafine kaolin particle after leafing, for example than about 0.3 micron particle that (e.s.d.) is thinner.This helps to produce the leafing pigment products with narrower size-grade distribution, if the size-grade distribution when not removing ultra-fine grain Comparatively speaking.The U.S. 4,948 the preceding, and 664 have illustrated for the situation that requires very narrow size-grade distribution, and leafing then carries out rough classification afterwards and the secondary particulate is removed step.Before leafing, the patentee does not remove elementary particulate.In illustrative embodiment, in the leafing process, produced a large amount of secondary particulates, need remove subsequently.Fine grain remove at people's such as Bundy United States Patent (USP) 4,943,324 and also belong in people's such as Bundy the United States Patent (USP) 5,085,707 be known as " taking off particulate (defining) ".In these patents, take off the particulate operation and always as if after appropriateness or slight leafing step, carry out.Sometimes fine grain removing is known as the term " desliming " that uses in present patent application.The patent of Bundy also discloses with the surface treatment to clay of this type of material such as Tai-Ace S 150 and hexamethylene-diamine.

The Kaolin pigments that also has realized that " expanded " leafing is a kind of effective means that improves the opacity of pigment.United States Patent (USP) 4,738,726 for example, discloses a kind of highly bulked Kaolin pigments that is used to make the water-borne coatings colorant, the filler that it is fit to make coating lightweight publication paper or is used as paper web (paper webs).Pigment is by will be a small amount of but the water-soluble cationic polyelectrolyte flocculation agent of significant quantity and kaolin clay pigment are mixed with expanded clay pigment in the presence of water make.Select basic kaolin clay to distribute to have certain particle before flocculation, 0.3 micron of the material ratio that wherein is lower than 35wt% is thinner.

Although aforementioned pigment has special characteristic, continue to seek to give paper to improve the new pigment of characteristic.Especially, rotogravure printing is opened the paper application and is had the special characteristics that requirement is satisfied, as compressibility, and printing (helio), opacity, sheet material gloss, smoothness and low glue spread.The applicant has found new method and color compositions, and they provide significantly improved paper property astoundingly, as above those that especially discussed in the rotogravure paper printing is used.

The present invention's general introduction

The present invention relates to produce the composition and the method for kaolin based pigment, it is given paper, is particularly useful for the paper of rotogravure printing with significantly improved characteristic.

One embodiment of the invention relate to the method for making kaolin type pigment, may further comprise the steps: (a) with kaolin clay leafing in addition, wherein the degree of kaolin clay leafing proceeds to a kind of like this degree: the size-grade distribution that will be lower than 2 μ m is brought up to excess layer from the about 5-40% that preceding is lower than the size-grade distribution of 2 μ m; (b) from the clay of leafing, remove that a part of particle less than 0.3 μ m; (c) absorb fillers;

Wherein the degree of leafing, remove and the interpolation of weighting agent is adjusted to and is enough to obtain to contain the degree that 5-30% is equal to or less than the particulate pigment of 0.3 μ mm less than the particulate of 0.3 μ m.

The advantage of composition of the present invention comprises the performance of improving the coating paper.Especially for the coating paper that in rotogravure printing is used, uses, in smoothness, rotary printing, brightness, the important improvement on the opacity has kept required sheet material gloss simultaneously.Improved performance makes that can reduce costliness under the prerequisite of not sacrificing optics and printing performance forges system clay or other more use of expensive additive, has obtained the sheet material gloss that improves simultaneously.

Being described in detail of the preferred embodiments of the invention

The compositions and methods of the invention relate to be given paper and is particularly useful for paper that rotogravure uses with significantly improved performance.The present invention will become clearer from following definition and the discussion of following.

Here Bao Gao size-grade distribution is that it is to be measured by common sedimentation techniques by the SEDIGRAPH_ particle-size analyzer that uses Micromeretics Inc based on by weight equivalent spherical diameter (e.s.d.).The measurement that it should be understood that clay particle size for 0.3 micron or thinner delaminated kaolins pigment has limited reproducibility.Therefore, when using the SEDIGRAPH_ analyser, when by another one operator test or when using different SEDIGRAPH_ analyser by weight this value of calculating of percentage ratio may be 45%.For the Kaolin pigments of leafing, limited reproducibility extends to the kaolin clay granularity that is higher than 0.3 micron.This should emphasize, because in the middle of the pigment of leafing several principal characters that are the present invention one.Another principal character of the present invention is expanded.The expanded structurizing that has caused pigment in being higher than the condensed water slurry of 55% solid content, this can have the value of raising to observe from Brookfield viscosity (or low-shear viscosity).Yet in the preparation of the pigment sample that is used for the SEDIGRAPH_ analysis, clay slurry is diluted to 6% solid and can't observes expanded or structurized effect between the particle to this diluting effect of expanded filler is feasible.

Leafing used herein be meant allow natural kaolin particle " stacked body (stacks) " or " brochure (booklets) " thus standing shear action in aqueous clay slurry splits sheet operation with the kaolin stacked body.Leafing can be by allowing the aqueous slurry of stacked kaolin particle at sand mill, ball mill or pebble mill, and forcing machine or rotor-stator colloidal mill, or stand shearing action in other appropriate device and carry out.With reference to the general U.S. Patent No. of transferring the possession of 5.645,635 (it is for reference that its disclosure is introduced into this paper) discussing fully about the peeling method of kaolin clay.

Term used herein " desliming " is meant the operation of thin fraction that separates and abandon the certain percentage of Kaolin clay suspension.Among each embodiment that here provides, take off the particulate operation and in whizzer, carry out.Need the Kaolin clay suspension of " desliming " to be transported in the whizzer and process therein and suspension is separated into thick fraction and thin fraction.This thin fraction can all be abandoned or the thin fraction of only selected that volume per-cent is abandoned, and remaining thin fraction is mixed to make further processing treatment with thick fraction.When the thin level timesharing of abandoning selected per-cent, expressed percentage takes off the percent by volume that the particulate level is meant the thin fraction of being abandoned usually.For example, take off particulate reach 40% level mean from 40% in the middle of the thin fraction of whizzer abandoned and from the residue 60% of the thin fraction of whizzer with mix to do further processing from the thick fraction of whizzer.

Term " expanded " is meant a kind of method, and clay pigment has improved scattering of light by this method modification, and it is can the quantitative performance of scattering coefficient, and the measuring method of the opacification ability of pigment is provided usually.With reference to the general US Patent No of transferring the possession of 4,640,716 and 4.738,726 (it is for reference to be introduced into this paper), it comprises and is used to prepare the expanded and method of expanded filler and more going through of raw material (" weighting agent ").

Term " hydration " is the clay that is used for describing and does not calcine (being the temperature that the basic crystalline structure of clay changes).For kaolin, the temperature that clay is maintained 450 ℃ will not change kaolinic crystalline structure.

The clay that is fit to use in the present invention comprises various hydrous kaolin clays.Although embodiments of the invention may demonstrate special size-grade distribution, the invention is not restricted to any special size-grade distribution.

After removing coarse sand and coarse impurity, contain the particle that is narrower than 2 microns (μ M) of the 40%-75wt% that has an appointment usually as the common kaolin clay raw ore in pigmentary kaolinic source.

In the processing of common kaolin, former mineral aggregate is added in the blunger so that clay is dissociated into little particle, and it mixes with water and primary dispersion agent and forms clay-neatly mud or slurry.The primary dispersion agent can be a water glass, sodium polyphosphate or sodium polyacrylate and well known in the prior art those.The consumption of dispersion agent is normally in about 0.025-0.3wt% scope, based on the weight of dry clay.Electronegative with the clay particle that the primary dispersion agent is handled, this makes and causes that when particle suspension is in water they repel mutually.Clay-aqueous slurry pump from blunger is extracted in rake classifier or wet cyclone and the screen cloth to remove most coarse sand and very coarse impurity.The slurry that takes off coarse sand is collected in the large-scale stirring-type storage tank and pump is extracted in the source mill.In source mill, before processed, in factory, the kaolin slurry is collected in the large-scale storage tank.

Usually the kaolin slurry is at first peeled off layer by layer, by the successive centrifugal treating kaolin particle is dissociated into thick and thin fraction.The purpose of this step is to remove remaining coarse sand and very coarse brochure.Thin fraction is further to process needed intermediate.The degree of peeling off layer by layer is subjected to the influence of desired particle size distribution, rheological property and the pigment optical property of the finished product.Generally speaking, it is 70-95% that the kaolin slurry is stripped to the fraction ratio that is narrower than 2 μ m layer by layer, preferably is stripped to the 80-90% of 2 μ m.Peel off layer by layer and can after other downstream ore dressing or procedure of processing are as the back leafing, carry out.

The leafing of clay is to be undertaken by usual way, as those methods of describing in the above definition of leafing.To foundation such as clay raw ore material granularity distribution to a certain extent for obtaining the desired degree of delamination of benefit of the present invention, the source of former mineral aggregate, the variable of smoothness of fine grain amount and surface of clay and so on changes in the former mineral aggregate.

Yet, for size-grade distribution be lower than 2 μ m 50% to 70% the former mineral aggregate of a kind of clay that is lower than 2 μ m, by the 5-40% δ (delta) of leafing to 2 μ m, preferred leafing has obtained good result to the 10-20% δ of 2 μ m.In other words, 5-40% " δ " is meant that size-grade distribution under 2 μ m levels brought up to than leafing 2 μ m size-grade distribution level height not the absolute percentage point of 5-40%.

Be lower than under the leafing level of 5% δ, especially particle size distribution has limited reproducibility when using common sedimentation particle size distribution test technology.For example, typical sedigraph has the repeatability of about 4-5% under 2 μ m, so will have limited tolerance range and numerical value by using this commercial measurement to be lower than 50% size-grade distribution δ value.

Be higher than under 40% the leafing level, the ratio of size-grade distribution δ (rate) can stop to increase and can't obtain further leafing benefit for all actual purpose.So pursue and to be higher than 40% leafing δ and not have practical significance.

In enforcement of the present invention, peel off layer by layer at random and before or after leafing, carry out, or further carry out, to remove remaining coarse sand and too coarse particle in the downstream.Generally speaking, it is 70-95% that the kaolin slurry is stripped to the fraction ratio that is narrower than 2 μ m layer by layer, preferably is stripped to the 80-90% of 2 μ m.The present invention is without wishing to be held to any concrete stripping conditions layer by layer.

The desliming of leafing clay can be by any carrying out in numerous common desliming devices or the method, as listed those in the relevant definition of desliming in front.

Desliming is meant that particle size separation has caused removing particle the thinnest in the size-grade distribution.The thinnest particle is commonly considered as being narrower than the particle of 0.3 μ m.Desliming is usually finished by mechanical means.Although chemical desliming method is a popular technology,, enforcement of the present invention comprises the very any method of fine particle of effectively removing in the kaolin slurry.The example that fine grain chemistry is removed is disclosed in the general U.S. Patent application of transferring the possession of and submitted on July 11st, 08/891,666,1997, and it is for reference that its disclosure is introduced into this paper.

The mechanical desliming of the aqueous slurry that takes off flocculation of hydrous kaolin can be undertaken by using whizzer, as nozzle feed disk whizzer (nozzle discharge disc centrifuge) or rolling discharge whizzer.The example of full scale plant is the horizontal three-phase centrifuge, available from Alfa Laval company (Greenwood, Indiana State).Alfa Laval whizzer applies " g " power more much higher than common Bird whizzer (about 3,000-10 is in the scope of 000g power).Top speed AlfaLaval whizzer can will be narrower than about 0.3 micron kaolin particle and bigger kaolin particle sharp separation.In the laboratory, desliming is to finish through about 7-15 branch clock time under 2800rpm with low speed centrifuge Damon/IEC CU-5000 whizzer.Generally speaking, desliming is carried out the size-grade distribution that reaches under 0.3 μ m level at 5-30%, in the preferred 5-20% scope.

Can believe, can use various weighting agents according to the present invention and satisfy the application requiring of especially considering the rotogravure printing performance.This weighting agent is meant water solubles cationic polyelectrolyte flocculation agent, for example is described in the general United States Patent (USP) of transferring the possession of 4,738,726, and it is for reference that its disclosure is introduced into this paper.Cationic polyelectrolyte is meant and contains the high molecular material that carries a plurality of cationic charges under a kind of pH value when using.

Suitable polyelectrolyte comprises QAS polymer, and the multipolymer of secondary aliphatic amine and Epicholorohydrin contains poly-(quaternary ammonium) polyester salt of quaternary nitrogen, polyamine and poly-imines such as polymine and have the polyamphoteric electrolyte of a plurality of cation groups.

In the U.S. patent application of transferring the possession of 08/936 unexamined, common, one group of useful especially polyelectrolyte describing as weighting agent in 702 (on September 24th, 1997 submitted to, and its disclosure is introduced into for reference) is the polyquaternary amine polymkeric substance that forms from following reaction: (ⅰ) secondary amine such as dialkylamine and difunctional epoxy compound or its precursors reaction or (ⅱ) lower dialkyl amine (C ₁-C ₃), two sense epoxy type reactants (identical) and be selected from ammonia, primary amine, have the Alkylenediamine of 2-6 carbon atom and the third reactant reaction of polyamines with (1).

(ⅰ) Zu polymkeric substance is disclosed among the United States Patent (USP) Re.2 8.807 (people such as Panzer).It is for reference that the whole disclosure of this second edition patent is introduced into this paper.

As at second edition described in the patent, (ⅰ) Zu polyquaternary amine polymkeric substance is that reaction from secondary amine such as dialkylamine and dual functional epoxy compounds or their precursor obtains.

According to the disclosure of second edition patent, mainly form by following repeating unit as the water dissolvable or the water-dispersible polyquaternary amine polymkeric substance of second component of the present invention:

Wherein R and R ₁Be independently selected from low alkyl group (1-3 carbon atom).E is from epihalohydrin, the residue that obtains after the epoxide, the difunctional reactant of the compound of selecting in the precursor of epihalohydrin and diepoxides and their mixture, and m and n are the integers with basic identical numerical value.X ^_Expression constitutes the negatively charged ion of the part of poly quaternary ammonium compound; M and n are the integers of representing the molar weight of amine reactant and difunctional reactant compounds respectively.In a word, the polymkeric substance of (1) group only comprises two kinds of reactants: lower dialkyl amine and dual functional epoxy type reactant.

As for epoxy reactant, epihalohydrin is to be particularly useful as Epicholorohydrin and epibromohydrin.Epicholorohydrin is preferred.Diepoxides is as 1, and 4-butyleneglycol-diglycidyl ether also is useful.The precursor of epihalohydrin and diepoxides also is useful.The example of precursor comprises: 1, and 3-dichlorohydrine-2 and 1,4-two chloro-2,3-dihydroxyl butane.

As for the secondary amine that can be used as reactant, they comprise dimethylamine, diethylamine, dipropylamine and contain C ₁-C ₃The secondary amine of the mixture of alkyl.

Suitable reaction parameter sees United States Patent (USP) Re.28, and 807, here no longer repeat.(ⅰ) Zu preferred polymers forms from dimethylamine and Epicholorohydrin reaction.This is reflected among the embodiment 1 that reprints patent and is described in detail.

(ⅰ) Zu preferred polyquaternary amine polymkeric substance is considered to have following structure: (ⅰ) Zu the suitable polymkeric substance that is purchased is with trade(brand)name SHARPFLOC_22, and SHARPFLOC_23 and SHARPFLOC_24 sell.The molecular weight of these polymkeric substance is that 000-10 is in the scope of 000 atomic mass unit (nucleidic mass) about 2 according to test.The concrete molecular weight of these polymkeric substance is not crucial, as long as polymkeric substance keeps water-soluble or water dispersible.

Spendable according to the present invention (ⅱ) group polymkeric substance is characterized by branching polyquaternary amine polymkeric substance and is described in detail in United States Patent (USP) Re.28 on type, among 808 people such as () Panzer.It is for reference that the whole disclosure of this second edition patent is introduced into this paper.

As at 28,808 second editions described in the patents, (ⅱ) Zu water-dispersible polyquaternary amine polymkeric substance mainly is made up of following repeating unit:

R wherein, R ₁, E, m, with n with above identical for the definition that provides of (ⅰ) group polymkeric substance.A is from ammonia, and primary amine has the Alkylenediamine of 2-6 carbon atom, the many alkyl polyamines with following structure Wherein y represents the integer of about 1-5, R ₃Be alkylidene group with about 2-6 carbon atom, and R ₄Be selected from hydrogen, the omega-amino-alkyl of the alkyl of 1-3 carbon atom and 2-6 the carbon atom of having an appointment is arranged, have for example polyglycol amine of following structure

Wherein a is the integer among about 1-5, the residue that obtains after the piperazine heteroaromatic diamines, the difunctional reactant of the multiple functionalized polyamines of selecting in the polyamines of molecular weight about at the most 10,000-polyprotonic acid condensation product; X ^_It is the ion that constitutes the anionicsite of this poly quaternary ammonium compound; M and p are the integers of the molar weight of expression amine reactant, and the ratio of m and p is about 99: 1 to 85: 15; N represents to form the molar weight of E of the main chain of polyquaternary amine, and the molar weight of being represented by n is substantially equal to the summation of the molar weight of m and p; This multiple functionalized amine except the E that contains needed that quantity of difunctional reactant, also contain quantity from zero to big about this A the E of remaining whole functional groups number; The summation of m, n and p should make provides a kind of like this poly quaternary ammonium compound, this compound is as the 37wt% aqueous solution, based on the gross weight of the cationic moiety of polyquaternary amine, having 25 ℃ of viscosity is the integer that satisfies the negatively charged ion matching request of poly quaternary ammonium compound at least 100 centistokes and Z.

In a word, (ⅱ) polymkeric substance of group is formed by three kinds of reactants: rudimentary two (C ₁-C ₃) alkylamine, dual functional epoxy type reactant (with identical in the polymkeric substance of (ⅰ) group) and from ammonia, primary amine, have the Alkylenediamine of 2-6 carbon atom and the polyamines that defines equally with above A the third reactant of selecting.The third reactant of preferred type is the ammonia or the amine of trifunctional at least, promptly can be at the amine that reacts on 3 positions that is not less than of amine.The example of this class amine is whole primary amine and/or polyfunctional amine such as quadrol and diethylenetriamine.

(ⅱ) the concrete reaction parameter of Zu cationic polyelectrolyte is at aforesaid U.S. Patent Re.28, specifies in 808.Preferably (ⅱ) group polymkeric substance is the crosslinked polyquaternary amine polymkeric substance (referring to for example United States Patent (USP) Re.28,808 embodiment 2) that forms from quadrol, dimethylamine and Epicholorohydrin.

Preferably (ⅱ) group polyquaternary amine polymkeric substance is considered to have following structure:

(ⅱ) the suitable polymkeric substance that is purchased of set type is trade(brand)name SHARPFLOC_25, SHARPFLOC_26, SHARPFLOC_27, SHARPFLOC_28, SHARPFLOC_29, SHARPFLOC_30, SHARPFLOC_31, SHARPFLOC_32 and SHARPFLOC_33 sell.The molecular weight of these polymkeric substance is after tested in the scope of about 20,000 to 500,000 nucleidic mass.The concrete molecular weight of these polymkeric substance is not crucial, as long as polymkeric substance keeps water-soluble or water dispersible.Therefore, the aforementioned molecular weight ranges of disclosed other polyelectrolyte should not thought restricted in the present invention meaning in the present invention.

Other again one group of useful especially polyelectrolyte is a quaternary ammonium salt.Most preferably dialkyl group, diallyl QAS polymer, they contain the alkyl of 1-4 the carbon atom of having an appointment, preferable methyl.

Molecular weight is after measured 50, has been found that in enforcement of the present invention particularly useful and obtained FDA permission (license number 176-170) moisture and that fat food is used with trade(brand)name polymkeric substance 261 LV available from the dimethyl diallyl aliquat polymkeric substance of Calgon Corporation between the 000-250.000.Do not obtain the FDA permission at many reagent that are proposed to be used in expanded clay before this.Yet, the invention is not restricted to polymkeric substance 261 LV, because as if other cationic flocculant can provide same effect, even be not excellent result.

The usage quantity of polyelectrolyte must be controlled carefully so that improve the opacity of clay fully by forming expanded (coalescent) structure (wherein agglomerate has enough intensity to bear the mechanical force that applies in manufacturing and final use), but must limit carefully to guarantee that this product can make solids content at least 55% or higher clay-aqueous slurry, this slurry has acceptable rheological property.As discussed above, although expanded rheological property to spissated kaolin slurry has strong influence, by the size-grade distribution of SEDIGRAPH_ analysis to measure can normally not show and expanded before the noticeable change compared.

The amount that is used to dispose the cationic polyelectrolyte salt of kaolin clay can change with the variation of the characteristic of polyelectrolyte, and these characteristics comprise the electric density of polyelectrolyte, the size-grade distribution of clay and added the solids content of the clay slurry of polyelectrolyte.Here preferred dimethyldiallylammonium salt polyelectrolyte with median particle at about 0.4-0.9 micron, preferred 0.5-0.7 μ m with to have the fraction ratio that is narrower than 0.3 micron be to be lower than that 25% clay uses and when the about 15-40wt% of clay solid content aforementioned taken off in the clay-aqeous suspension of flocculation the interpolation polyelectrolyte, the consumption of polyelectrolyte is the about 0.20wt% of about 0.02-of the no moisture weight of clay, the most preferably from about about 0.12wt% of 0.06-.When using not enough polyelectrolyte, will be lower than desirable for the effect of opacity in the application of paints and printing.On the other hand, excessive polyelectrolyte can damage other desired properties of clay, especially rheological property.Water miscible polyelectrolyte under agitation is added in the slurry as rare aqueous solution (for example 1/4-4wt% concentration), has obtained well distributed in slurry.Can the environment for use temperature.It is desirable to the slurry with clay, the solution of polyelectrolyte or both are heated to about 150 °-180 °F.

When cationic polyelectrolyte is added in the slurry that takes off flocculation of pH value in the 6-9 scope, obtained gratifying result.After polyelectrolyte, because the result of flocculation, suspension is basically by thickening.Prepared thickened systems is in addition acidifying then, typically to being lower than the 5pH value, usually to pH value 3-4, and uses common clay SYNTHETIC OPTICAL WHITNER (hydrosulphite such as sodium bisulfite) bleaching and aging.Employed SYNTHETIC OPTICAL WHITNER usually is any colorific ferric ion composition to be reduced into have more water-soluble and therefore a kind of reductive agent of easier ferrous state of removing.SYNTHETIC OPTICAL WHITNER is that the amount with 1-15 pound SYNTHETIC OPTICAL WHITNER/dry clay per ton joins in the clay mineral slurry.The slurry of handling dewaters by filtering, and obtains the wet cake of solids content between the about 60wt% of about 50-.Filter cake washs then to remove soluble substance and to make it fluidisation by adding secondary dispersion agent such as tetrasodium pyrophosphate or sodium polyacrylate or both mixtures then.In order to compensate the problem that when slurry of the present invention is stored or stored, transports or standing contact high temperature in the process of moderate shearing condition, may run into, more advantageously use at United States Patent (USP) 4,772,332 and 4,767, those disclosed additive in 466, replacement resembles the common secondary dispersion agent of tetrasodium pyrophosphate or sodium polyacrylate and so on.

Product of the present invention can transport with slurry or with dried forms.Wish that slurry has total solids level and is at least 55% solid.The type of additive used according to the invention is included in United States Patent (USP) 4,772.332 and 4,767, those that describe in 466, and it is for reference that their disclosure is introduced into this paper.These additives be particularly useful for compensating when aqueous slurries of the present invention by storage or the problem of storing, being run into during contact high temperature in the transportation, or for example be made into pigment printing paste and need use when providing acceptable rheological property simultaneously when slurry.

The rheological property of pigment of the present invention requires to involve simultaneously acceptable highly filled slurry rheological property and pigment printing paste rheological property.The viscosity of the highly filled suspension of clay paint pigment must be enough low to allow to mix and pump is taken out.After binding agent was introduced, the prepared coating mill base must also have suitable viscosity, to carry out aftertreatment and to be coated on the sheet of paper.Also have, wish that very acquisition has the calendering scraps of paper of the band coating of good opacity, gloss, brightness and printing.

Usually, paper producer idea is used the clay paint pigment that can form highly filled clay-aqueous slurry, has the 1200cp of being lower than when being measured under 20r.p.m by the Brookfield viscometer, preferably is lower than the low-shear viscosity of 800cp.The shear viscosity of these slurry should make can be than using " A " float 16 * 10 ⁵Dyne-centimetre under the Hercules terminal point viscosity that records be 150r.p.m., the slurry that is preferably 800r.p.m. has more viscosity.Those skilled persons will know in the prior art, and when using He Keershi (Hercules) viscometer and 1100r.p.m. or higher measurement terminal point, terminal point viscosity is with under 1100r.p.m. 10 ⁵Dyne-centimetre unit report; Along with the raising of dyne-centimetre value, apparent viscosity descends.Use abbreviation term " dyne " to replace 10 traditionally ⁵Dyne-centimetre.Therefore, " 2 dyne " clay slurry is not as " 9 dyne clay " such thickness of slurry.The expression phrase 150r.p.m. of Shi Yonging or higher hereinafter, perhaps 800r.p.m. or higher wishes to comprise lower viscosity, so that terminal point measurements is to be to report with dyne at 1100r.p.m. with this numerical value.

Another requirement of pigment of the present invention is that it can experience and produces and finally use each stage and can be disperseed be formed with the weather resistance of the solid argillaceous-aqueous slurry of height of acceptable viscosity simultaneously.The general wet processes scheme that the typical case uses when making pigment of the present invention is an absorb fillers before filtering, therefore filtering pigment is cake form, and it contains expanded aggregation (assemblages) when becoming liquid slurry when this filter cake " is in harmonious proportion (made down) ".Expression phrase " mediation " is common in industry and refers to the preparation of dispersed color-aqueous slurry.Sometimes, be necessary filter cake is applied mechanical work so that viscosity is reduced to operable value.Pigment must have enough tolerances so that bear mechanical force in this treating processes.Expanded filler also must have enough stability to keep expanded structure to take out as pump in impeller pump at high shear rate under the high shear rate that runs into when height is consolidated the argillaceous aqueous slurry under shearing action.And when the clay water slurry that takes off flocculation used the mediation equipment of standard to be made into pigment printing paste, pigment must be able to remain.Simultaneously, pigment must exist in coating application and calendering process subsequently.The friability of the bulked structure that is obtained by the prior art chemical treatment of moisture clay makes to have limited industrial application value.Usually, the standard of the weather resistance of bulked structure is the hold facility of improved opacification after above-mentioned aftertreatment.

When the preparation pigment printing paste, common binding agent or binder mixtures use with the sliding slurry of the clay that takes off flocculation.For example, useful pigment printing paste composition is to obtain by mixing the clay that the about 20 weight part binding agents of about 5-/per 100 weight part polyelectrolyte are handled fully with the sliding slurry of clay.When being used to apply lightweight publication paper, this pigment printing paste is produced a kind of product of sheet material glossy with excellent printing, smoothness, opacity, brightness and desired level.

Term used herein " binding agent " is meant known those materials that use with paper colors, and its is assisted granules of pigments to keep together and and then coating protection is held on the paper surface.This class material comprises, for example, and casein, soy-protein, starch (dextrin, Sumstar 190, ferment convert starch, hydroxylation starch), gelatin, polyvinyl alcohol, rubber latex, styrene-butadiene copolymer latex and synthetic polymerized resin emulsion (as forming) from vinylformic acid and vinyl-acetic ester.When binding agent is included in the starch of jet cooking under the expanded filler existence of being added, hope is heated the slurry that has added the clay of polyelectrolyte in the preparation of expanded filler, in order to avoid forming pigment printing paste undue viscosity, that can not handle.Temperature in about 150 ° of-200 scopes is recommended.About 180 temperature can successfully be used.Yet the use of heating in preparation process can reduce the scattering power of pigment.

Pigment printing paste composition prepared in accordance with the present invention can be coated on the sheet of paper in normal way.Expanded filler can use separately or use with known coating clay or other pigment blending, to improve the optical property and the printing performance of the coating scraps of paper.Those that binding agent that uses in pigment printing paste and additive are that the typical case uses in this industrial circle and be known for those skilled persons in the art.Expanded filler also can be used as filler and is used for paper web.

Embodiment

Embodiment 1

The performance of four kinds of (4) Kaolin pigments compares.First kind of pigment P-1 is by the coating level kaolin of Engelhard Corporation with the standard grading leafing of trade(brand)name NUCLAY sale.The slurry of NUCLAY is to prepare according to the PL-1 of the EngelhardCorporation that describes in U.S. patent 4,738,726 and PL-3 program, and it is for reference that the content of the disclosure thing is introduced into this paper already.To be used for the agent of redispersion P-1 dispersing of pigments in (make down) program be that SODA ASH LIGHT 99.2, part and polyacrylic acid and Sodium hexametaphosphate 99 (" SAP " dispersion agent) are respectively with the 18-21wt% aqueous solution of activeconstituents weight ratio 45.5/24.5/30 being in harmonious proportion.

Second kind of pigment P-2 is from the aqeous suspension preparation of taking off flocculation of Georgia kaolin clay.Taking off flocculation agent is water glass.Solids content is about 29%.Size-grade distribution at the aqeous suspension medium clay soil that takes off flocculation is to be lower than 68%, 0.76 micron median diameter of 2.0 microns and to be lower than 22% of 0.3 micron diameter.Suspension further takes off flocculation with the sodium polyacrylate of 2 pounds of/ton consumptions, and 1: 1 volume ratio using granulated glass sphere and pigment suspension in 5 gallons of wet lapping machines is by the leafing size-grade distribution 15-20% δ under 2 μ m extremely.The size-grade distribution of leafing suspension is to be lower than 85.8%, 0.55 micron median diameter of 2 microns and to be lower than 25.9% of 0.3 micron diameter.Leafing suspension carries out classification then in whizzer Damon/TEC CU-5000 whizzer, obtained size-grade distribution and be to be lower than 87.9%, 0.50 micron median diameter of 2.0 microns and be lower than 0.3 micron diameter 28.3% overflow suspension.Prepared suspension flows through magnetic separator magnet, and (Carpco-CC WHIMS3 * 4L) obtain to be higher than 83 brightness, actual brightness is 83.4.Suspension has obtained size-grade distribution by using the Damon/, the centrifugal treating of TECCU-5000 whizzer to come desliming be 16.2% a kind of dirty suspension that is lower than 84.0%, 0.66 micron median diameter of 2.0 microns and is lower than 0.3 micron diameter.Prepared suspension uses the Tai-Ace S 150 of 8 pounds of/ton consumptions to flocculate, and with sulfuric acid pH value is reduced to 2.8 and the sodium bisulfite (being purchased with KBrite) of 10 pounds/ton of interpolations subsequently.The pigment suspension of flocculation carries out the disc type filtration and carries out rinsing to remove water-soluble salt with isopyknic at least rinse water.The filter cake of rinsing about 5-7 pound/ton SAP dispersion agent redispersion.The suspension of this redispersion is divided into several parts to carry out spraying drying and adds to again then in the suspension to improve solid content to 67.0% total solids.

The third pigment P-3 is the desliming that provided with trade(brand)name EXSILON by Engelhard Corporation and expanded kaolin coating level pigment (promptly not leafing), and uses C-235 dispersion agent described below to be in harmonious proportion according to described Engelhard PL-1 of above mediation for P-1 pigment and PL-3 method.

The 4th kind of pigment E-1 is the expanded modification of P-2 pigment, but in the redispersion packing difference arranged.In order to prepare E-1, be diluted to 20% solids content and expanded with the Poly Dimethyl Diallyl Ammonium Chloride (polyDADMAC) of 1.6 pounds/ton (0.08%) from the desliming intermediate of P-2.The interpolation of poly-DADMAC can impel suspension to flocculate.Further flocculation takes place after with sulfuric acid the pH value being reduced to about 3.5.Also have, 10 pounds/ton sodium bisulfite adds as SYNTHETIC OPTICAL WHITNER.Prepared dilute suspension wears out a night, carries out the disc type filtration and carries out rinsing to remove water-soluble salt with isopyknic at least rinse water.The filter cake of rinsing carries out redispersion with special dispersion stabilizer additive packages, is enough to improve the pH value to about 6.5-7.0.

Employed special dispersing agent package is sodium lignosulfonate, part neutral polypropylene, the five sodium-salt of amino three (methylene phosphonic acids) and the mixture of caustic alkali, and with trade(brand)name Colloid 235 (" C-235 ") from Vinings Industries, Inc buys.The various versions of special dispersion agent package are disclosed in United States Patent (USP) 4,772, and in 332, it is for reference that disclosure is introduced into this paper.The suspension of this redispersion is divided into several parts to carry out spraying drying and adds to again then in the suspension to improve solid content to about 61-62% total solids.

Although pigment P-1 has used the dispersion agent package different with E-3 with pigment P-3 with P-2, these are different not have expection can influence below the pigment printing paste composition properties of report, is the C-235 package acquisition sheet material brightness lower slightly than SAP package.In any case because C-235 uses with institute of the present invention invention composition, the use of C-235 can not obtain the benefit in the brightness to a certain extent in the pigment printing paste composition, with the colorant composition that uses SAP dispersion agent package Comparatively speaking.

Table 1. hydrous kaolin pigments performance

	P-1	?P-2	?P-3	?E-1
	P-1	?P-2	?P-3	?E-1	GE brightness	87.8	?86.5	?87.0	?86.5
Sedigraph mean particle size (μ m)	0.71	?0.66	?0.56	?0.63	GE brightness	87.8	?86.5	?87.0	?86.5
Sedigraph mean particle size (μ m)	0.71	?0.66	?0.56	?0.63	% is at 2 μ m	?79	?84	?90	?89
% is at 1 μ m	?60	?66	?70	?70	% is at 2 μ m	?79	?84	?90	?89
% is at 1 μ m	?60	?66	?70	?70	% is at 0.3 μ m	?22	?16	?22	?14
Slurry-% total solids	67.2	?67.0	?62.6	?61.4	% is at 0.3 μ m	?22	?16	?22	?14
Slurry-% total solids	67.2	?67.0	?62.6	?61.4	?pH	?5.9	?6.7	?6.2	?7.0
?Brookfield?20?rpm(cps)1	205	?130	?80	?590	?pH	?5.9	?6.7	?6.2	?7.0
?Brookfield?20?rpm(cps)1	205	?130	?80	?590	?Brookfield?100?rpm(cps)1	186	?116	?94	?250
Hercules A float 21100 rpm	?690?rpm	18.8 dyne	2.5 dyne	15.7 dyne	?Brookfield?100?rpm(cps)1	186	?116	?94	?250

Annotate: 1-Brookfield viscosity, the viscosity that in this embodiment and embodiment subsequently, records by TAPPIT648-om-88.

2-Hercules viscosity is pressed United States Patent (USP) 4,738 in this embodiment and subsequent embodiment, measure described in 726.

The rheological property of the physicals of four kinds of pigment and their pigment slurries is shown in Table 1.In the experimental error of Tao Luning, the size-grade distribution of P-2 and E-1 is different basically in front, although exist following true: E-1 is the expanded modification of P-2, and compares with P-3 with P-1, and P-2 and E-1 have the kaolin particle fraction that is lower than 0.3 μ m of lower amount.Influence expanded between E-1 and not expanded P-2 can be found out from the solids content of their lower shear rheology performances and their suspension.P-2 can make 67% solids suspension and E-1 only makes 61.4% solids suspension.The Brookfield rheology has disclosed the expanded structurizing that causes makes E-1 that much higher low shearing difficulty be arranged, even under the solids content more much lower than P-2.

Four kinds of pigment is made into to belong to the pigment printing paste of 58% total solids level of LWC formulation for coating material, this prescription contains a kind of hydrous kaolin pigment of 88 parts, phenylethylene/butadiene (styrene-butadiene rubber(SBR)) the latex paint base of 12 parts of calcined clays and 6.0 parts, 0.8 part calcium stearate.

The pH value of pigment printing paste is adjusted to 8.2.This colorant is applied on the wire side (wire side) of 28 pounds of lightweight body paper with the Dow applicator by using the laboratory.Glue spread is coating 5.5 pounds/R (R=ream=3300 square feet).Sheet material is nursed one's health and calendering on the soft chuck in laboratory (nip) roller calender under 50% relative humidity and 72.After reaching this condition, P-1 (NUCLAY) contrast has obtained gloss target value 57-58.

The coating paper is carried out 75 ° of gloss of following test: TAPPI (T480 om-85), TAPPI opacity (T425 om-91), ISO brightness (ISO method #2469).Parker PrintSurf (10kgF/cm ²) (ISO 8791/4 and TAPPI T555), compressibility, and Heliotest (rotary printing test).

The compressibility of the band coating scraps of paper is to measure according to the Engelhard shop experiment of Parker Print Surf (PPS) test by part.The principle of PPS test is: the slickness (or roughness) of measuring the surface of the scraps of paper or cardboard is pushed down the function of the speed of passing through between this surperficial flat circular platform on this surface with specified pressure as air.Measure compressibility by the relative air velocity of test under two kinds of different pressures in the present invention.Air velocity is by at 5kg/cm2 and 10kg/cm ²Carrying out PPS down tests and measures.Calculate compressibility then:

Compressibility=100[1-[(PPS 5 _Kg/cm2-PPS 10 _Kg/cm2)/PPS 5 _Kg/cm2]]

Measure by this method, numerical value is low more, and compressibility is high more, and vice versa.Generally acceptedly be, fine gravure processes demand a kind of can be on its whole surface the compressible paper of contact print cylinder reliably, guarantee to have obtained the highest possible printing ink absorption rate from the cylinder in view of the above.

In the Helio test, the scraps of paper of band coating print with the photogravure cylinder with ink logo, and this cylinder has been preserved the cavity that some diameters that pass through reduce.Therefore, these print trial product at one end have big ink dot and have little ink dot at the other end.Begin to count the point of jump at big ink dot end, printing quality is registered as the beginning distance (in millimeter) of omitting between the point to the 20th from print trial.For given glue spread, long more in this distance of millimeter, the printing of coating paper is good more.The result is summarised in the table 2.

Table 2. performance that contains the polymkeric substance scraps of paper expanded, that pigment printing paste desliming and clay leafing applies

	P-1	P-2	P-3	R-1
Gloss	57	59	57	57
The Tappi opaqueness	81.3	83.7	82.5	83.0
ISO brightness	71.0	71.7	71.9	71.5
PPS	1.20	1.27	1.20	1.16
Compressibility	79.2	76.6	79.3	74.6
Helio printing (mm)	40	41	45	54

Annotate: lower value means compressibility and PPS (smoothness) better

Data show in the table 2, although the pigment P-2 of leafing and desliming obtains comparing significantly improved opacity and brightness with pp-1 (NUCLAY) contrast, do not observe the obvious improvement of helio printing.Yet by with the expanded P-2 of a small amount of polyDADMAC (that is, make E-1), E-1 demonstrates confers similar advantages in opacity and brightness, but in the Helio printing, on smoothness (from low PPS reading) and the compressibility wonderful remarkable improvement is arranged.Helio printing, compressibility and the smoothness of the coating scraps of paper of handling with E-1 obviously are better than P-3, not leafing but expanded filler.

Embodiment 2

The new batch of material of preparation P-1 and E-1 is respectively referred to as P-2 ' and E-1 '.Pigment P-2 ' is from the aqeous suspension preparation of taking off flocculation of Georgia kaolin clay.The size-grade distribution of the aqeous suspension medium clay soil that takes off flocculation be lower than 2 microns 64% and be lower than 15% of micron diameter O.3.30.0% solids suspension further takes off flocculation with the sodium polyacrylate of 2 pounds of/ton consumptions, and 1: 1 volume ratio using granulated glass sphere and pigment suspension in 5 gallons of wet lapping machines is by the leafing size-grade distribution 15-20% δ under 2 μ m extremely.The size-grade distribution of leafing suspension be lower than 2 microns 82% and be lower than 20% of 0.3 micron diameter.Leafing suspension carries out classification then in whizzer Damon/TEC CU-5000 whizzer, obtained size-grade distribution and be being lower than 2 microns 89% and be lower than 0.3 micron diameter 22% overflow suspension.Prepared suspension has obtained 83.5 pigment brightness and by magnet (magnet) separator.Suspension is 15% a kind of dirty suspension that is lower than 87%, 0.65 micron median diameter of 2 microns and is lower than 0.3 micron diameter by come desliming to obtain size-grade distribution with the centrifugal treating of Damon/TEC CU-5000 whizzer.Prepared suspension uses the Tai-Ace S 150 of 8 pounds of/ton consumptions to flocculate, and with sulfuric acid pH value is reduced to 2.8 and the sodium bisulfite (being purchased with KBrite) of 10 pounds/ton of interpolations subsequently.The pigment suspension of flocculation carries out the disc type filtration and carries out rinsing to remove water-soluble salt with isopyknic at least rinse water.According to described in the embodiment 1 and the method for using, the filter cake of rinsing is with about 5-7 pound/ton SAP dispersion agent redispersion.The suspension of this redispersion is divided into several parts to carry out spraying drying and adds to again then in the suspension to improve solid content to 67.1 total solids.

Pigment E-1 ' is the expanded modification of P-2 ' pigment, but in the redispersion packing difference is arranged.In order to prepare E-1 ', be diluted to 20% solids content and expanded with the Poly Dimethyl Diallyl Ammonium Chloride (polyDADMAC) of 1.6 pounds/ton (0.09%) from the desliming intermediate of P-2 '.The interpolation of poly-DADMAC can impel suspension to flocculate.Further flocculation takes place after with sulfuric acid the pH value being reduced to about 3.5.Also have, 10 pounds/ton sodium bisulfite adds as SYNTHETIC OPTICAL WHITNER.Prepared dilute suspension wears out a night, carries out the disc type filtration and carries out rinsing to remove water-soluble salt with isopyknic at least rinse water.According to described in the embodiment 1 and employed method, be enough to improve the extremely consumption of about 6.5-7.0 of pH value with a kind of, the filter cake of rinsing carries out redispersion with C-235 dispersing additive package.The suspension of this redispersion is divided into several parts to carry out spraying drying and adds to again then in the suspension to improve solid content to about 61-62% total solids.

The performance of the improved expanded pigment of table 3.

	P-1	P-2’	E-1’
GE brightness	87.8	87.2	86.0
Sedigraph mean particle size μ m	0.71	0.65	0.70
% is at 2 μ m	79	87	87
% is at 1 μ m	60	66	66
% is at 0.3 μ m	22	15	11
Slurry-%TS	67.1	67.1	61.5
pH	5.9	7.2	6.2
Brookfield 20 rpm(cps)	186	180	116
Brookfield 100 rpm(cps)	169	132	106
Hercules A float 1100 rpm	687rpm	390	759

Comprise with embodiment 1 in the physicals of three kinds of (3) pigment of employed identical P-1 (NUCLAY) control sample and the rheological property of these pigment slurries be given in the table 3.In the experimental error of Tao Luning, the size-grade distribution of P-2 ' and E-1 ' is inequality basically in front, is the expanded modification of P-2 ' although the following fact: E-1 ' is arranged.P-2 ' and E-1 ' have the kaolin particle fraction that is lower than 0.3 μ m than the lower amount of P-1.Expanded influence can be found out from their solids content of suspension again between E-1 ' and not expanded P-2 '.P-2 ' can make 67.1% solids suspension and E-1 ' only makes 61.5% solids suspension.If P-2 ' and E-1 ' suspension compare under 61.5% solid, the low-shear viscosity of P-2 ' is low-down, with E-1 ' Comparatively speaking.This expected results is based on expanded structurizing effect.

By use basically with embodiment 1 in identical prescription, three kinds of (3) pigment are formulated into the pigment printing paste of 57% total solids level.Pigment printing paste is applied on the 28 pound weight body paper by using CLC applicator (guiding the intermittent application device at a high speed).Glue spread is 5.0 pounds/3300 square feet.The conditioning condition of coated sheet is identical with condition among the embodiment 1.The calendering condition can make the Nuclay contrast obtain 56 gloss target value after selecting.The various performances of coated sheet are given in the table 4, according to the identical calendering condition of indicating in following table 4.

The performance of table 4. coated sheet

	Identical calendering
	Identical calendering				P-(NUCLAY)	88
?P-2’		88			P-(NUCLAY)	88
?P-2’		88			?E-1’			88	?94
Calcined clay	12	?12	?12	?6	?E-1’			88	?94
Calcined clay	12	?12	?12	?6	% sheet material gloss	56	?63	?58	?63
ISO brightness	71.1	?72.0	?71.9	?71．8	% sheet material gloss	56	?63	?58	?63
ISO brightness	71.1	?72.0	?71.9	?71．8	The Tappi opaqueness	84.7	?85.8	?85.8	?85.8
The Helio printing	74	?79	?89	?86	The Tappi opaqueness	84.7	?85.8	?85.8	?85.8
The Helio printing	74	?79	?89	?86	?PPS?10?Kgf／cm ²	0.99	?0.92	?0.88	?0.89
Compressibility	72.2	?72.0	?70.8	?72.5	?PPS?10?Kgf／cm ²	0.99	?0.92	?0.88	?0.89
Compressibility	72.2	?72.0	?70.8	?72.5	The CLC behaviour in service	Better	Better	Well	Better

Calendering condition: identical calendering

Pli (pound/linear inch) 1093

Temp(°F)???????????175

Speed (feet per minute clock) 37

Number of pass times 2

Under identical calendering condition, E-1 ' obtains comparing much better coating and the printing performance of product P-1 in the same old way under identical calcined clay content (12 parts).E-1 ' has bigger advantage than unpuffed modification sample P-2 ' equally.Compare with the P-1 contrast, Helio printing, smoothness (PPS), opacity, brightness and compressibility are significantly improved.Simultaneously, under the calcined clay (12 parts) of equal parts, E-1 ' is superior to P-2 ', and the former has significant improvement in the helio printing on smoothness (PPS) and the compressibility.The sheet material gloss of E-1 ' can keep helio printing, smoothness, brightness and opacity simultaneously by calcined clay is reduced to 6 parts of improvement that obtain remarkably from 12 parts.By reducing the amount of calcined clay, the CLC behaviour in service also is modified.

Embodiment 3

This embodiment has illustrated the use as the another kind of weighting agent of buying with trade(brand)name SHARPFLOC_26 (" SF-26 ") from Sharpe Speciality Chemical company, secondary aliphatic amine and the multipolymer of Epicholorohydrin are described, and with the result and the weighting agent polyDADMAC that is used to make E-1 and E-1 ' compare.This time, use with embodiment 1 and 2 in employed another kind of desliming inequality and leafing the kaolin clay intermediate and in following table 5, be appointed as P-4.Intermediate is that to have particle size distribution be that the former mineral aggregate that is lower than about 50-75% of 2 μ m forms.P-4 be filtered with rinsing after also carry out redispersion with the SAP dispersion agent of embodiment 1.Pigment E-2 is expanded with 1.6 pounds/ton poly (DADMAC), and E-3 is expanded with 2.0 pounds/ton SF-26 polymkeric substance.After expanded, two pigment suspensions filter and carry out rinsing to remove soluble salt with rinse water.E-1 and E-2 pigment suspension with 6 pounds/ton carry out redispersion with employed SAP dispersion agent as described in example 1 above, and by 325 eye mesh screens with carry out spraying drying.Therefore in the present embodiment, pigment P-1, P-4, E-2 and E-3 all use the SAP dispersion agent.P-4, E-2, the pigment performance and the slurry performance of E-3 and front contrast P-1 (NUCLAY) pigment are given in the table 5.E-2 and E-3 both have the kaolin particle fraction that is lower than 0.3 μ m than P-1 and the low slightly amount of P-4.Two pigment are blended to than P-1 contrast and the much lower solids content of P-4 pigment.

The performance of table 5. hydrous kaolin pigments

	P-1	P-4	E-2	E-3
GE brightness	87.8	90.7	90.5	90.6
% is at 2 μ m	79	88	88	88
% is at 1 μ m	60	69	70	68
% is at 0.3 μ m	22	20	17	16
Slurry-% total solids	67.1	68.1	61.1	61.0
pH	5.8	6.9	6.8	6.8
Brookfield20rpm(cps)	200	280	170	120
Brookfield100rpm(cps)	156	176	150	120
HerculesA float 1100rpm	825rpm	405rpm	14.8 dyne	234rpm

According to embodiment 1 in the same generic LWC formulation for coating material discussed, pigment P-1, E-2 and E-3 are made into the pigment printing paste of 57% total solids level.Pigment printing paste is applied on the 28 pound weight body paper by using CLC applicator (guiding the intermittent application device at a high speed).Glue spread is 5.5 pounds/3300 square feet.The conditioning condition of coated sheet is identical with condition among the embodiment 1.The calendering condition can make the Nuclay contrast obtain 54 gloss target value after selecting.The various performances of coated sheet are given in the table 6, according to the identical calendering condition of indicating in following table 6.

The performance of the table 6. coating scraps of paper

P-1(Nuclay)	88
E-2		88
E-3			88
Calcined clay	12	12	12
% sheet material gloss	54	52	52
ISO brightness	68.8	70.0	70.2
The Tappi opaqueness	81.4	81.7	82.9
PPS is at 10kgf/cm ²	0.91	0.86	0.80
The Helio printing	57	70	82

Calendering condition: identical calendering

Pli (pound/linear inch) 1407

Temp(°F)?????????????150

Speed (feet per minute clock) 36.5

Number of pass times 2

E-2, poly-(DADMAC) expanded filler obtains comparison according to better printing performance of P-1 and smoothness.E-3 (multipolymer of secondary aliphatic amine and Epicholorohydrin) obtains much better printing performance, smoothness and the opaqueness than E-2 (poly-(DADMAC) expanded filler).

Individually, P-1 and P-4 are according to containing 100% hydrous kaolin clay (promptly not having calcined clay), and the generic LWC formulation for coating material of 6.0 parts of phenylethylene/butadiene (styrene-butadiene rubber(SBR)) latex and 0.5 part of calcium stearate is made into the pigment printing paste of 58.0% total solids.Mill base is applied on the wire side that is purchased the LWC body paper with 5.5 pounds/3300 square feet amount.The performance of the coating scraps of paper be shown in table 7.

Table 7

	P-1	P-4
% sheet material gloss	57	61
Brightness	69.7	71.0
The Tappi opaqueness	83.3	83.8
PPS,10Kgf/cm ²	0.90	0.83
The Helio printing	71	74

Although compare with P-1, P-4 obtains smoothness, brightness and improved slightly opaqueness preferably, but the Helio printing is not improved in the various variable ranges of helio test, this with table 6 in E-2 and E-3 demonstrate more opposite than the significantly improved performance of P-1.

Be described in front the explanation of principle of the present invention, preferred embodiment and operator scheme.Yet the present invention who needs protection should not think and is limited to special shape disclosed herein, and is nonrestrictive because they are considered to illustration purpose.Those skilled persons can do many modification and variation in the prior art under the prerequisite that does not break away from spirit of the present invention.

Claims

1. make the method for kaolin based pigment, may further comprise the steps:

(a) with kaolin clay leafing in addition, wherein the kaolin clay leafing proceeds to the size-grade distribution that is lower than 2 μ m and brings up to the degree of excess layer from about 5-40% of the size-grade distribution that preceding is lower than 2 μ m;

(b) from the clay of leafing, remove that a part of particle less than 0.3 μ m; With

(c) absorb fillers; The degree of leafing wherein removes interpolation with weighting agent less than the particulate of 0.3 μ m and is adjusted to and is enough to obtain to contain the degree that 5-30% is equal to or less than the particulate pigment of 0.3 μ mm.

2. the process of claim 1 wherein that the leafing of kaolin clay proceeds to a kind of like this degree: improve the size-grade distribution that is lower than 2 μ m and make it than the high approximately 10-20% of the size-grade distribution that is lower than 2 μ m before the leafing.

3. the method for claim 2, wherein this weighting agent is a cationic polyelectrolyte.

4. the method for claim 3, wherein the addition of cationic polyelectrolyte is about 0.02-0.20wt% of the no moisture weight of clay.

5. the method for claim 4, wherein polyelectrolyte is selected from quaternary ammonium salt, and the multipolymer of secondary aliphatic amine and Epicholorohydrin contains poly-(quaternary ammonium) polyester salt, polyamine and the poly-imines of quaternary nitrogen.

6. the method for claim 5, wherein this polyelectrolyte is a quaternary ammonium salt.

7. the method for claim 6, wherein polyelectrolyte is the dialkyl diallyl QAS polymer that contains the C1-C4 alkyl of having an appointment.

8. the method for claim 7, wherein alkyl is a methyl.

9. the method for claim 4, wherein polyelectrolyte is the reaction product of secondary amine and difunctional epoxy compound or its precursor.

10. the method for claim 4, wherein polyelectrolyte is the dialkylamine that contains 1-3 carbon atom, difunctional epoxy compound or its precursor and be selected from ammonia, primary amine, have the reaction product of the 3rd reactant of the Alkylenediamine of 2-6 carbon atom and polyamines.

11. the method for claim 9, wherein difunctional epoxy compound is an epihalohydrin.

12. the method for claim 10, wherein difunctional epoxy compound is an epihalohydrin.

13. the method for claim 9, wherein difunctional epoxy compound is an Epicholorohydrin.

14. the method for claim 10, wherein difunctional epoxy compound is an Epicholorohydrin.

15. the method for claim 9, wherein secondary amine is dimethylamine, diethylamine, or dipropylamine and difunctional epoxy compound are epihalohydrins.

16. the method for claim 15, wherein secondary amine is that dimethyl amine and epihalohydrin are Epicholorohydrins.

17. the method for claim 10, wherein the 3rd reactant is that the amine and the bifunctional epoxide of ammonia or the trifunctional at least that is selected from primary amine, quadrol and diethylenetriamine are epihalohydrins.

18. the method for claim 17, wherein the 3rd reactant is that quadrol and epihalohydrin are Epicholorohydrins.

19. the process of claim 1 wherein that the particle that is lower than 0.3 μ m is in the 5-20% scope.

20. the method for claim 1-19 further comprises the step of removing coarse sand and very coarse brochure from clay, is the clay slurry of 70-95% so that obtained to be lower than the size-grade distribution of 2 μ m before absorb fillers.

21. product by the method production of any one among the claim 1-19.

22. the product of producing by the method for claim 20.

23. contain the paper of the spawn of claim 21, this product is to exist as paper coating form, filler form or this two kinds of forms.

24. contain the paper of the spawn of claim 22, this product is to exist as paper coating form, filler form or this two kinds of forms.