GB1564867A – Composite silicate pigment
– Google Patents
GB1564867A – Composite silicate pigment
– Google Patents
Composite silicate pigment
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Info
Publication number
GB1564867A
GB1564867A
GB9890/77A
GB989077A
GB1564867A
GB 1564867 A
GB1564867 A
GB 1564867A
GB 9890/77 A
GB9890/77 A
GB 9890/77A
GB 989077 A
GB989077 A
GB 989077A
GB 1564867 A
GB1564867 A
GB 1564867A
Authority
GB
United Kingdom
Prior art keywords
clay
pigment
silicate
composite
sil
Prior art date
1976-03-19
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB9890/77A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Westvaco Corp
Original Assignee
Westvaco Corp
Priority date (The priority date 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 date listed.)
1976-03-19
Filing date
1977-03-09
Publication date
1980-04-16
1977-03-09
Application filed by Westvaco Corp
filed
Critical
Westvaco Corp
1980-04-16
Publication of GB1564867A
publication
Critical
patent/GB1564867A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
239000000049
pigment
Substances
0.000
title
claims
description
115
239000002131
composite material
Substances
0.000
title
claims
description
68
BPQQTUXANYXVAA-UHFFFAOYSA-N
Orthosilicate
Chemical compound
[O-][Si]([O-])([O-])[O-]
BPQQTUXANYXVAA-UHFFFAOYSA-N
0.000
title
claims
description
18
239000004927
clay
Substances
0.000
claims
description
113
230000003287
optical effect
Effects
0.000
claims
description
33
238000000034
method
Methods
0.000
claims
description
32
150000003839
salts
Chemical class
0.000
claims
description
24
NLYAJNPCOHFWQQ-UHFFFAOYSA-N
kaolin
Chemical compound
O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O
NLYAJNPCOHFWQQ-UHFFFAOYSA-N
0.000
claims
description
19
239000004115
Sodium Silicate
Substances
0.000
claims
description
15
238000006243
chemical reaction
Methods
0.000
claims
description
15
229910052914
metal silicate
Inorganic materials
0.000
claims
description
14
229910052911
sodium silicate
Inorganic materials
0.000
claims
description
14
NTHWMYGWWRZVTN-UHFFFAOYSA-N
sodium silicate
Chemical group
[Na+].[Na+].[O-][Si]([O-])=O
NTHWMYGWWRZVTN-UHFFFAOYSA-N
0.000
claims
description
13
239000000047
product
Substances
0.000
claims
description
12
239000002002
slurry
Substances
0.000
claims
description
12
229910052910
alkali metal silicate
Inorganic materials
0.000
claims
description
11
239000005995
Aluminium silicate
Substances
0.000
claims
description
9
235000012211
aluminium silicate
Nutrition
0.000
claims
description
9
238000001556
precipitation
Methods
0.000
claims
description
8
UXVMQQNJUSDDNG-UHFFFAOYSA-L
Calcium chloride
Chemical group
[Cl-].[Cl-].[Ca+2]
UXVMQQNJUSDDNG-UHFFFAOYSA-L
0.000
claims
description
6
239000001110
calcium chloride
Substances
0.000
claims
description
6
229910001628
calcium chloride
Inorganic materials
0.000
claims
description
6
239000011734
sodium
Substances
0.000
claims
description
5
VYPSYNLAJGMNEJ-UHFFFAOYSA-N
Silicium dioxide
Chemical compound
O=[Si]=O
VYPSYNLAJGMNEJ-UHFFFAOYSA-N
0.000
claims
description
4
159000000007
calcium salts
Chemical group
0.000
claims
description
4
239000012467
final product
Substances
0.000
claims
description
4
229910052751
metal
Inorganic materials
0.000
claims
description
4
239000002184
metal
Substances
0.000
claims
description
4
238000002156
mixing
Methods
0.000
claims
description
4
238000005406
washing
Methods
0.000
claims
description
4
DGAQECJNVWCQMB-PUAWFVPOSA-M
Ilexoside XXIX
Chemical compound
C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+]
DGAQECJNVWCQMB-PUAWFVPOSA-M
0.000
claims
description
3
FYYHWMGAXLPEAU-UHFFFAOYSA-N
Magnesium
Chemical compound
[Mg]
FYYHWMGAXLPEAU-UHFFFAOYSA-N
0.000
claims
description
3
HCHKCACWOHOZIP-UHFFFAOYSA-N
Zinc
Chemical compound
[Zn]
HCHKCACWOHOZIP-UHFFFAOYSA-N
0.000
claims
description
3
229910052788
barium
Inorganic materials
0.000
claims
description
3
DSAJWYNOEDNPEQ-UHFFFAOYSA-N
barium atom
Chemical compound
[Ba]
DSAJWYNOEDNPEQ-UHFFFAOYSA-N
0.000
claims
description
3
239000011575
calcium
Substances
0.000
claims
description
3
238000001914
filtration
Methods
0.000
claims
description
3
229910052749
magnesium
Inorganic materials
0.000
claims
description
3
239000011777
magnesium
Substances
0.000
claims
description
3
230000001376
precipitating effect
Effects
0.000
claims
description
3
229910052725
zinc
Inorganic materials
0.000
claims
description
3
239000011701
zinc
Substances
0.000
claims
description
3
OYPRJOBELJOOCE-UHFFFAOYSA-N
Calcium
Chemical compound
[Ca]
OYPRJOBELJOOCE-UHFFFAOYSA-N
0.000
claims
description
2
229910052783
alkali metal
Inorganic materials
0.000
claims
description
2
150000001340
alkali metals
Chemical class
0.000
claims
description
2
229910052791
calcium
Inorganic materials
0.000
claims
description
2
238000001035
drying
Methods
0.000
claims
description
2
229910052708
sodium
Inorganic materials
0.000
claims
description
2
239000012798
spherical particle
Substances
0.000
claims
description
2
WHXSMMKQMYFTQS-UHFFFAOYSA-N
Lithium
Chemical compound
[Li]
WHXSMMKQMYFTQS-UHFFFAOYSA-N
0.000
claims
1
ZLMJMSJWJFRBEC-UHFFFAOYSA-N
Potassium
Chemical compound
[K]
ZLMJMSJWJFRBEC-UHFFFAOYSA-N
0.000
claims
1
239000003795
chemical substances by application
Substances
0.000
claims
1
229910052744
lithium
Inorganic materials
0.000
claims
1
229910052700
potassium
Inorganic materials
0.000
claims
1
239000011591
potassium
Substances
0.000
claims
1
239000000377
silicon dioxide
Substances
0.000
claims
1
239000012463
white pigment
Substances
0.000
claims
1
239000000203
mixture
Substances
0.000
description
34
239000002245
particle
Substances
0.000
description
21
239000000945
filler
Substances
0.000
description
19
238000009472
formulation
Methods
0.000
description
17
238000000576
coating method
Methods
0.000
description
16
239000000463
material
Substances
0.000
description
14
239000000378
calcium silicate
Substances
0.000
description
13
229910052918
calcium silicate
Inorganic materials
0.000
description
13
235000012241
calcium silicate
Nutrition
0.000
description
13
OYACROKNLOSFPA-UHFFFAOYSA-N
calcium;dioxido(oxo)silane
Chemical compound
[Ca+2].[O-][Si]([O-])=O
OYACROKNLOSFPA-UHFFFAOYSA-N
0.000
description
12
239000002585
base
Substances
0.000
description
11
239000011248
coating agent
Substances
0.000
description
10
-1
clay
Chemical compound
0.000
description
7
239000008199
coating composition
Substances
0.000
description
7
238000009826
distribution
Methods
0.000
description
6
238000002474
experimental method
Methods
0.000
description
6
229940037003
alum
Drugs
0.000
description
5
238000010924
continuous production
Methods
0.000
description
5
239000006069
physical mixture
Substances
0.000
description
5
XLYOFNOQVPJJNP-UHFFFAOYSA-N
water
Substances
O
XLYOFNOQVPJJNP-UHFFFAOYSA-N
0.000
description
5
238000000635
electron micrograph
Methods
0.000
description
4
239000007787
solid
Substances
0.000
description
4
229920002472
Starch
Polymers
0.000
description
3
239000000654
additive
Substances
0.000
description
3
238000013019
agitation
Methods
0.000
description
3
229910052784
alkaline earth metal
Inorganic materials
0.000
description
3
239000006227
byproduct
Substances
0.000
description
3
229910052622
kaolinite
Inorganic materials
0.000
description
3
239000008107
starch
Substances
0.000
description
3
235000019698
starch
Nutrition
0.000
description
3
VEXZGXHMUGYJMC-UHFFFAOYSA-M
Chloride anion
Chemical compound
[Cl-]
VEXZGXHMUGYJMC-UHFFFAOYSA-M
0.000
description
2
239000004111
Potassium silicate
Substances
0.000
description
2
238000005299
abrasion
Methods
0.000
description
2
238000010521
absorption reaction
Methods
0.000
description
2
230000000996
additive effect
Effects
0.000
description
2
ZCCIPPOKBCJFDN-UHFFFAOYSA-N
calcium nitrate
Chemical compound
[Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O
ZCCIPPOKBCJFDN-UHFFFAOYSA-N
0.000
description
2
238000011161
development
Methods
0.000
description
2
238000011156
evaluation
Methods
0.000
description
2
239000000835
fiber
Substances
0.000
description
2
238000004519
manufacturing process
Methods
0.000
description
2
NNHHDJVEYQHLHG-UHFFFAOYSA-N
potassium silicate
Chemical compound
[K+].[K+].[O-][Si]([O-])=O
NNHHDJVEYQHLHG-UHFFFAOYSA-N
0.000
description
2
229910052913
potassium silicate
Inorganic materials
0.000
description
2
235000019353
potassium silicate
Nutrition
0.000
description
2
125000006850
spacer group
Chemical group
0.000
description
2
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Calcium cation
Chemical compound
[Ca+2]
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
0.000
description
1
239000005083
Zinc sulfide
Substances
0.000
description
1
239000003082
abrasive agent
Substances
0.000
description
1
229910001860
alkaline earth metal hydroxide
Inorganic materials
0.000
description
1
PNEYBMLMFCGWSK-UHFFFAOYSA-N
aluminium oxide
Inorganic materials
[O-2].[O-2].[O-2].[Al+3].[Al+3]
PNEYBMLMFCGWSK-UHFFFAOYSA-N
0.000
description
1
229910000329
aluminium sulfate
Inorganic materials
0.000
description
1
235000011128
aluminium sulphate
Nutrition
0.000
description
1
238000013459
approach
Methods
0.000
description
1
239000007900
aqueous suspension
Substances
0.000
description
1
238000000149
argon plasma sintering
Methods
0.000
description
1
229960000892
attapulgite
Drugs
0.000
description
1
238000011021
bench scale process
Methods
0.000
description
1
238000005282
brightening
Methods
0.000
description
1
VSGNNIFQASZAOI-UHFFFAOYSA-L
calcium acetate
Chemical compound
[Ca+2].CC([O-])=O.CC([O-])=O
VSGNNIFQASZAOI-UHFFFAOYSA-L
0.000
description
1
239000001639
calcium acetate
Substances
0.000
description
1
229960005147
calcium acetate
Drugs
0.000
description
1
235000011092
calcium acetate
Nutrition
0.000
description
1
229910001424
calcium ion
Inorganic materials
0.000
description
1
238000003490
calendering
Methods
0.000
description
1
239000007795
chemical reaction product
Substances
0.000
description
1
150000003841
chloride salts
Chemical class
0.000
description
1
230000002596
correlated effect
Effects
0.000
description
1
229920001971
elastomer
Polymers
0.000
description
1
239000012065
filter cake
Substances
0.000
description
1
239000010419
fine particle
Substances
0.000
description
1
239000004816
latex
Substances
0.000
description
1
229920000126
latex
Polymers
0.000
description
1
238000011068
loading method
Methods
0.000
description
1
230000014759
maintenance of location
Effects
0.000
description
1
238000005259
measurement
Methods
0.000
description
1
229910021645
metal ion
Inorganic materials
0.000
description
1
150000002739
metals
Chemical class
0.000
description
1
230000007935
neutral effect
Effects
0.000
description
1
238000007645
offset printing
Methods
0.000
description
1
239000003973
paint
Substances
0.000
description
1
229910052625
palygorskite
Inorganic materials
0.000
description
1
238000002360
preparation method
Methods
0.000
description
1
239000010453
quartz
Substances
0.000
description
1
230000002787
reinforcement
Effects
0.000
description
1
150000004760
silicates
Chemical class
0.000
description
1
238000004513
sizing
Methods
0.000
description
1
159000000000
sodium salts
Chemical class
0.000
description
1
235000019351
sodium silicates
Nutrition
0.000
description
1
238000001694
spray drying
Methods
0.000
description
1
238000003860
storage
Methods
0.000
description
1
239000000126
substance
Substances
0.000
description
1
238000006467
substitution reaction
Methods
0.000
description
1
239000000758
substrate
Substances
0.000
description
1
238000012360
testing method
Methods
0.000
description
1
239000001038
titanium pigment
Substances
0.000
description
1
239000011800
void material
Substances
0.000
description
1
229910052984
zinc sulfide
Inorganic materials
0.000
description
1
DRDVZXDWVBGGMH-UHFFFAOYSA-N
zinc;sulfide
Chemical compound
[S-2].[Zn+2]
DRDVZXDWVBGGMH-UHFFFAOYSA-N
0.000
description
1
Classifications
C—CHEMISTRY; METALLURGY
C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
C09C1/0081—Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound
C09C1/0084—Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound containing titanium dioxide
C09C1/0087—Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound containing titanium dioxide only containing titanium dioxide and silica or silicate
C—CHEMISTRY; METALLURGY
C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
C09C1/0081—Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2004/00—Particle morphology
C01P2004/01—Particle morphology depicted by an image
C01P2004/03—Particle morphology depicted by an image obtained by SEM
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2004/00—Particle morphology
C01P2004/20—Particle morphology extending in two dimensions, e.g. plate-like
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2004/00—Particle morphology
C01P2004/30—Particle morphology extending in three dimensions
C01P2004/32—Spheres
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2004/00—Particle morphology
C01P2004/51—Particles with a specific particle size distribution
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2004/00—Particle morphology
C01P2004/60—Particles characterised by their size
C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2004/00—Particle morphology
C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2006/00—Physical properties of inorganic compounds
C01P2006/12—Surface area
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2006/00—Physical properties of inorganic compounds
C01P2006/22—Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2006/00—Physical properties of inorganic compounds
C01P2006/60—Optical properties, e.g. expressed in CIELAB-values
C—CHEMISTRY; METALLURGY
C01—INORGANIC CHEMISTRY
C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
C01P2006/00—Physical properties of inorganic compounds
C01P2006/80—Compositional purity
Description
PATENT SPECIFICATION ( 11) 1564867
r ( 21) Application No 9890/77 ( 22) Filed 9 March 1977 0 ( 31) Convention Application No 668 436 ( 19) ( 32) Filed 19 March 1976 in t ( 33) United States of America (US) he ( 44) Complete Specification published 16 April 1980 ( 51) INT CL 3 CO 9 C 1/42 ( 52) Index at acceptance C 4 A 6 ( 54) COMPOSITE SILICATE PIGMENT ( 71) We, WESTVACO CORPORATION, of 299 Park Avenue, New York, New York 10017, USA, a corporation of the State of Delaware, USA, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the
following statement: 5
The present invention relates in general to inorganic composite pigments.
More particularly, the invention relates to a composite pigment comprising clay and a metal silicate The pigment is prepared according to a precipitation reaction wherein spherical, hydrous metal silicate particles are precipitated on the planar surfaces of clay particles having a platelet-type structure Subsequently, when the 10 composite pigment is incorporated in a sheet of paper or the like, the precipitated metal silicate particles act as spacers between individual clay particles to produce void volume or pigment-air interfaces and provide improved optical properties to the paper The composite pigment so produced has an unexpectedly high light scattering power as compared with that of the base clay material alone, or as 15 compared with that of a simple physical mixture of the two components Moreover, with only a small amount of the metal silicate component precipitated on the base clay material, the optical efficiency of the composite pigment approaches that of the metal silicate component alone Finally, based on the experimental data disclosed herein, the composite pigment of the present invention finds particularly 20 good application in papermaking.
Clays are familiar components of the papermaking process and the term «clay» as used herein, refers to a class of earthly materials that are used as pigments in the papermaking process as filler materials, sizepress components and in coatings For instance, as used in the paper industry, the term clay ordinarily refers 25 to Kaolin or china clay, but it also includes attapulgite clay In general, however, the clays useful in the present invention are only those which have a platelet-type structure Ordinary kaolin clay or kaolinite meets most of the requirements of a good papermaking pigment except for its low index of refraction, 1 55 Therefore, clays are often used in the papermaking process in conjunction with more 30 expensive and more optically efficient pigments in order to meet the optical requirements of the final product.
In addition, the patent literature contains several teachings for modifying clay to produce a more optically efficient pigment For instance, U S Patent 2, 296,637 discloses a process for acidifying a clay/sodium silicate mixture to increase the dry 35 bulking value, oil absorption, and brightening and opacifying properties of clay.
Moreover, U S Patent 3,690,907 discloses a clay base pigment comprising a mixture of clay with an alkaline earth metal hydroxide that has improved optical properties.
On the other hand, metal silicates are also well known pigments in the paper 40 industry For instance, calcium silicates are sometimes used as fillers in paper to improve the bulk, opacity and brightness of the final product However, calcium silicate, like clay, has a fairly low refractive index, of 1 50.
Accordingly, like clay, calcium silicate is often modified or used in conjunction with other more optically efficient pigments to produce high quality 45 papers.
Also, it is known to attach calcium silicate pigment to papermaking pulp to increase the pigment retention For instance, in U S Patent 2,599,094 (among others issued to W L Craig), there is disclosed a process for precipitating calcium silicate on cellulosic pulp fibers after pretreating the pulp with a chloride solution.
In addition, U S Patent 2,296,618 discloses a silicate modified titanium pigment with improved stability against heat and light And, U S Patent 2,296,639 discloses a zinc sulfide pigment coated with a metal silicate to produce increased oil absorption with what is said to be excellent surface hiding power Meanwhile, in 5 U.S Patent 2,786,777 (among others assigned to Columbia-Southern Chemical Corporation), there is disclosed a method for preparing a composite pigment with calcium silicate and alumina.
However, none of the above noted patents discloses a composite pigment comprising a metal silicate and clay, and none of the patents known to applicant 10 discloses a precipitation reaction for precipitating a silicate pigment onto the planar surface of a platelet-type clay particle to produce a composite pigment having an unexpectedly high optical efficiency.
According to one aspect of the present invention there is provided a composite silicate pigment comprising a clay component and a metal silicate component The 15 clay component is preferably obtained from a class of papermaking clays known generally as kaolin clay or kaolinite, and the metal silicate component is a watersoluble alkali metal silicate, such as sodium silicate The preferred method for preparing the composite pigment comprises the steps of, (a) forming an aqueous suspension of a clay pigment, (b) blending into the clay slurry a quantity of a salt 20 such as calcium chloride, (c) metering into the slurry of clay and salt at high shear a quantity of a silicate component such as sodium silicate, and, optionally, (d) adjusting the p H of the slurry with the addition of alum to a p H no lower than p H 4, before (e) filtering and washing the precipitated product to remove any soluble salts The product obtained is then either used directly in the papermaking process 25 or dried, such as by spray drying or the like, to form a powdered pigment for later use.
During the reaction, the spherical, hydrous metal silicate pigment particles are precipitated on the planar surfaces of the clay particles Later on, when incorporated in a sheet of paper or the like, the metal silicate particles act as 30 spacers between individual clay particles, to create additional air interfaces on sheet drying The result of the precipitation reaction is to produce a vast improvement in the optical efficiency of the clay component with as little as 10 % by weight silicate precipitated on the clay In addition, the scatterinig coefficient of the composite pigment is considerably higher than the scattering coefficient of a 35 physical mixture of the two component pigments.
Examples of water-soluble salts of polyvalent metals that may be used in the process of the present invention include the water-soluble salts of calcium, barium, zinc and magnesium however, from a purely economical point of view, the calcium salts are deemed most desirable Then alkali metal silicate preferred for the 40 invention is sodium silicate, although other alkali metal silicates, such as potassium silicate, may be employed In addition, different grades of clays having properties similar to those of kaolin clays or kaolinite may be employed in preparing the composite pigments disclosed Of the polyvalent alkaline earth metal salts useful for the present invention, calcium chloride is the preferred soluble calcium salt, 45 although other salts such as calcium nitrate or calcium acetate could be used Of course, as noted hereinbefore, other water-soluble chloride salts, such as salts of barium, zinc or magnesium, could also be used as a substitute for calcium chloride.
The amount of alkaline earth metal salt added to the clay slurry should be proportioned so as to obtain an excess over the stoichiometric quantity required to 50 react with the silicate component The salt is added to the clay slurry under turbulent mixing conditions wherein the salt dissociates, permitting the earth metal to become chemically attached to the clay particles In the case of calcium chloride, the calcium ions are adsorbed onto the clay and the chloride goes into solution Generally, the preferred method is to add the alkaline earth metal salt to 55 the clay slurry prior to adding the silicate component However, reversing the order of addition still produces a precipitated product, albeit one having less optical efficiency.
The silicate component is preferably a water-soluble alkali metal silicate.
More particularly, sodium silicate is preferred, but other water-soluble alkali metal 60 silicates, such as sodium or potassium silicate, could be used Sodium silicates containing between 2 and 5 moles (preferably 3 to 4 moles) Si O 2 per mole of Na 2 O are preferred since they are commercially available and, as a rule, are the least expensive alkali metal silicates The silicate component is added to the clay/salt slurry under high shear wherein an almost instantaneous precipitation reaction 65 1,564867 occurs between the earth metal ions on the clay and the silicate ions from the alkali metal silicate The temperature of the reaction is not particularly critical and may range from 20 ‘C to 850 C The concentration of the silicate solution is correlated with the remaining variables so as to produce a final pigment having from 10-90 % by weight of the spherical silicate particles precipitated on the clay platelets for 5 improved optical efficiency.
The reaction of the present invention, if carried out without p H adjustment.
generally proceeds at a p H of p H 9-10 However, the optical efficiency of the final precipitated product and the yield of the reaction can both be increased with a p H adjustment down to a p H no lower than p H 4 The p H of the reaction is preferably 10 adjusted with the addition of alum However other additives could be used depending upon the ultimate use of the pigment In general, for wet end addition of the pigment on the papermachine as a filler material the p H should be fairly low, down to p H 4.
However, for coatings and sizepress application the p H need not be adjusted 15 to as low a level as p H 4 for satisfactory results In the latter cases, the reaction may be carried out at a neutral p H or at least on the alkaline side (p H 7 or above) with satisfactory results.
In the final stages of the process, the precipitated pigment is filtered and washed to remove any unwanted by products of the reaction such as soluble salts or 20 the like After washing and collecting the pigment, it may be used directly in the intended application or be further dewatered and dried for storage and/or shipment to the intended user.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 25 FIGURE 1 shows a schematic representation of a typical flow sheet for the process of the present invention; FIGURE 2 is an electron micrograph showing the platelet structure of a typical kaolin clay; FIGURE 3 is an electron micrograph showing the structure of a composite 30 precipitated pigment according to the present invention consisting of 80 % by weight of the clay of FIGURE 2 and 20 % by weight calcium silicate; FIGURE 4 is an electron micrograph showing the clay of FIGURE 2 incorporated in a handsheet, and FIGURE 5 is an electron micrograph showing the composite precipitated 35 pigment of FIGURE 3 incorporated in a handsheet.
The pigment of the present invention, because of its good dispersibility and excellent optical efficiency, is particularly suitable as a filler for use in the manufacture of paper In addition, the pigment is also useful in the papermaking process as a component of the sizepress or in paper coatings Moreover, the 40 pigment could be used in the manufacture of paints or as a reinforcement in rubber compositions.
The pigment is preferably manufactured in a continuous manner according to a process as shown schematically in FIGURE 1 For this purpose, a feed tank I is provided where the clay and a polyvalent metal salt are premixed under constant 45 agitation This mixture is pumped by pump 2 to one or more in-line mixers 4,4 ‘ where the clay/salt slurry is mixed with the alkali metal silicate component from tank 6 via pump 7 The precipitation reaction in the in-line mixers 4,4 ‘ must be under high shear to achieve a prompt salt-induced precipitation of the siliceous material on the clay Subsequently the p H of the precipitated pigment slurry may 50 be adjusted to a p H no lower than p H 4, for instance, by the addition of alum or the like from tank 8 via pump 9 to in-line mixer 4 ‘ After p H adjustment, the pigment is washed to remove any soluble salts and filtered for ultimate use.
The following examples are given in illustration and are not intended as a limitation on the scope of the invention 55 EXAMPLE I.
The following procedure was used to prepare several composite pigments for an initial evaluation as a paper filler materal In each case, 160 grams of water and from 10-40 grams of clay were slurried in a beaker under low shear agitation.
A quantity of Ca CI 22 H 20 was then added to the clay slurry in dry form and 60 allowed to mix for 15 minutes The clay/Ca CI 2 slurry was then added to a Waring blender Under high shear conditions, a 10 % by weight solids sodium silicate solution was added slowly to the clay/Ca Cd 2 slurry to induce precipitation of calcium silicate on the clay, and the mixture was allowed to mix for a total 1,564,867 of 2 minutes Subsequently, sufficient papermakers alum was added to the mixture to adjust the p H to p H 4-4 5 Mixing was continued for an additional 2 minutes The reaction product of clay with calcium silicate precipitated thereon was then washed in a Buchner funnel to remove soluble salt byproducts and the composite pigment was available for evaluation in handsheets 5 Several sodium silicate grades were evaluated having molar ratios of Si O 2:Na 2 O ranging from 2 50-3 75:1 However, for the experiment noted above, an O » O grade sodium silicate having a Si O 2:Na 2 O molar ratio of 3 22:1 was selected for optimum optical efficiency of the final product and because of its lower price.
Five commercially available Georgia Kaolin clays were used, ranging from a large 10 particle size WP filler clay ( 60 % by weight of particles finer than 2 microns) to a fine particle size Hydragloss 90 coating clay ( 97 % by weight of particles finer than 2 microns) Additionally, a delaminated clay, Nuclay, was included in the experiments In each case, the ratio of clay to sodium silicate in the composite pigment was varied at 20 % intervals from 0 to 100 % The ratio of sodium silicate to 15 Ca CI 2 2 H 20 was held constant at 2 8 to 1 Table I shows typical additive concentrations for the clay-calcium silicate composite products.
TABLE I.
Additive Concentrations-Pigment Preparation Pigment Ca CI 2 Sodium Composition Water Clay 2 H 20 Silicate Alum % gr gr gr gr gr.
Clay Ca Sil 160 40 3 57 10 8 Ca Sil 160 30 7 14 20 12 Clay 160 20 10 71 30 18 5 Ca Sil Ca Sil 160 10 14 28 40 26 0 Ca Sil 160 0 17 85 50 27 7 Tables II-VI summarize the optical performance of the composite pigments prepared with the different base clays The optical properties were determined 20 from handsheets which contained about 5 % by weight of the composite pigment.
Handsheets incorporating physical mixtures of clay and Ti O 2 were also prepared for comparison with the optical performance of the composite pigments In each case, a standard pulp blend was used for the fiber furnish and handsheets were prepared according to standard TAP Pl methods 25 1,564,867 1,564,867 5 TABLE 11.
Optical Comparison-WP Filler Clay Pigment Scattering Composition Filler Coefficient % Brightness Opacity % S’ Control 78 4 72 5 WP clay 79 3 75 9 4 93 158 Clay} Clay j 80 5 77 7 4 75 241 Ca Sil Clay ‘, Clavi f 81 1 78 5 4 79 273 Ca Sil J Clay} 82 1 78 9 4 71 304 Ca Sil} Clay Ca Sil} 82 4 78 4 4 45 317 Ca Sil Clay 29 Ti O 2 81 1 79 3 5 23 293 Ti O, Clay} 82 3 80 9 5 04 405 Ti O 2 I Clay 8.
C Ti 2) 83 O 82 0 4 99 465 Ti O 2 Clay ‘ 83 3 82 8 5 01 521 Ti O 2 6 1,564,867 6 TABLE III.
Optical Comparison-PDM Filler Clay Pigment Scattering Composition Filler Coefficient % Brightness Opacity % S’ Control 78 9 71 5 PDM Clay 78 7 74 9 4 08 156 Clay} Ca Sil Clay} 81 1 78 7 5 01 300 Clay} Ca Sil 4 O Ca Sil} 81 5 78 7 4 36 330 Clay’1 Ca Sil 82 1 79 6 4 64 380 Ca Sil J Clay} Ca Sil} 82 3 79 5 4 30 400 Clay Ti O 2 80 8 79 0 5 05 300 Ti O 2 Clay Ti O 21} 82 2 81 0 5 02 410 Clay Clay} 83 0 82 9 5 25 500 Ti O 2 Clay T 2 Clay 83 3 83 2 4 44 620 Ti O 2 7 1,564,867 7 TABLE IV.
Optical Comparison-Ultra White 90 Clay Pigment Scattering Composition Filler Coefficient % Brightness Opacity % S’ Control 78 4 71 8 UW 90 Clay 79 0 75 1 5 36 13 Ti O 2 83 3 84 0 4 45 66 Ca Sil 82 4 79 0 4 15 37 Clay ‘, Ca Sil 80 9 77 2 4 28 26 Ca Sil Clay Ca Sil} 81 7 78 9 4 44 37 Clay Ca Siy 81 3 78 6 3 74 37 Clay Clay} 81 8 78 6 4 13 34 Ca Sil Clay \’ 78 9 78 5 4 53 27 Ti O 2 f Clay 81 6 79 8 4 84 34 Ti O 2 I Clay Ti 2 82 7 82 0 5 05 46 Ti O} 8 Clay T 2 clay 83 0 83 6 5 13 55 Ti O 2 Pigment Composition Control Hydragloss 90 Clay Ca Sil Clay Ca Sil Clay Ca Sil J Clay Ca Sil Clay Ti O 2 1 Clay Ti O 2 Clay Ti O 2 f Clay Ti O 2 1,564,867 TABLE V.
Optical Comparison-Hydragloss 90 Clay Filler Brightness Opacity % 77.6 71 7 78.2 73 7 5 49 81.2 78 7 5 11 81.6 79 4 5 06 82.2 80 1 5 06 82.5 79 3 4 88 80.6 77 4 5 42 82.1 80 1 5 32 83.3 82 5 5 39 83.9 83 5 5 41 Scattering Coefficient S’ 291 327 327 357 220 365 471 552 1,564,867 TABLE VI.
Optical Comparison-Nuclay Clay Pigment Composition %/ Control Nuclay Clay A Ca Sil J Clay 1 Ca Sil f Clay Ca Sil J Clay Ca Sil I Clay 1 Ti O 2 J Clay, Ti O 2 J Clay} Ti O 2 J Clay Ti O 2 f Brightness Opacity 79.0 79.8 81.5 82.3 82.5 82.0 81.7 82.8 83.7 84.2 71.7 75.7 78.3 79.2 79.5 77.7 78.9 80.8 82.5 83.6 Surface areas of the clays used in Example I ranged from 8 m 2/gr for the Georgia Kaolin WP filler grade to 22 m 2/gr for the Hydragloss 90 coating grade clay from Huber Corporation Table II summarizes the optical comparisons of the composite pigment manufactured with the WP filler grade clay The composite pigment containing 80 % by weight WP clay with 20 % by weight Ca Sil precipitated thereon had an unexpected improvement in optical efficiency as compared with the WP clay alone However, the same pigment was slightly poorer in opacity development than a physical mixture of 80/% by weight WP clay and 20 % by weight Ti O 2 In a similar manner, as shown in Table III, the composite pigment containing % by weight PDM clay with 20 % by weight Ca Sil precipitated thereon had a drastic and unexpected increase in optical efficiency as compared with the PDM clay alone Moreover, the same pigment was equivalent in opacity development to a physical mixture of 80 % by weight PDM clay and 20 % by weight Ti O 2 Similar trends were found for the other clays used, as demonstrated by the data in Tables IV-VI In addition, the data showed that the scattering coefficient of the base clay materials generally increased as the amount of Ca Sil precipitated thereon increased.
Table VII shows some relationships between the surface areas of the base clay materials; the surface areas of the composite pigments prepared from the base clays, and general relationships between the particle size distribution of the clays and the percent increase in scattering coefficient achieved with the composite pigments In each case, the particle size distribution of the composite pigments were found to be substantially the same as the particle size distribution of the base clay materials used in each case As shown in the drawings (FIGURES 2-5), the relatively small spherical particles of calcium silicate that are precipitated onto the clay platelets do not significantly alter the overall particle size distribution of the base material.
Filler %/ 5.03 5.17 4.77 4.93 3.74 4.91 4.93 4.87 5.07 Scattering Coefficient S, 164 272 346 353 344 296 397 531 586 Hu l,54,867 10 TABLE VII.
Scattering Coefficient (s’) vs.
Particle Size Distribution Pigment Surface Scattering Scattering Composition Area Coefficient Coefficient % nm 2/gr S’ % increase Ultra White 90 Clay-90 % Finer than 2 microns Clay 12 6 13 Ca Siy J 16 4 26 100 Calay Ca Sil 20 5 37 169 Nuclay clav-80 % Finer than 2 microns Clay 11 7 164 Clay} 23 1 272 65 8 Ca, Clay 28 5 346 111 Ca Sil PDM Filler Clay-67 % Finer than 2 microns Clay 12 1 156 Clay} 23 7 241 54 5 Ca Sil Ca Sil 21 5 273 75 The data in Table VII demonstrate the importance of the selection of the commercially available base clay material in optimizing the contribution of the silicate component As the partricle size distribution of the base clay material in the composite pigment increases in fineness, the contribution of the silicate component 5 is enhanced Further, with increasing clay particle fineness, and at higher levels of substitution of the silicate component, the composite pigments provide equivalent optics when compared to the same level of Ti O 2 addition With the finer particle size coating clays, equivalent optical efficiency was obtained up to and including the 60 % clay-40 % Ca Sil or 40 % Ti O 2 filler systems (all percentages being in 10 weight) Accordingly, the data demonstrate that it is possible to duplicate the optical contribution of Ti O 2 in a paper substrate with the composite pigment of the present invention where from 20-40 % of the total wet end filler would be Ti O 2.
EXAMPLE II.
Samples of the composite pigment were prepared with a pilot plant apparatus 15 substantially as disclosed in FIGURE 1 except that only one in-line mixer was used.
The p H adjustment with papermakers’ alum was made in small batches prior to filtering and washing of the composite product PDM premium filler clay supplied by Georgia Kaolin was used in one set of experiments (Table VIII) and Ultra White 90 coating grade clay was used in a second set of experiments (Table IX) » O » grade 20 sodium silicate supplied by Philadelphia Quartz Company was selected as the silicate component and calcium chloride as the salt component of the process The sodium silicate solution concentration was varied from 0 42-1 68 lbs/gal at flow rates of from 0 60-1 14 gal /min into a clay/salt slurry containing 1 9-3 07 Ibs/gal.
of clay and from 0 17 to 0 27 Ibs/gal of salt From these reactions, several 25 composite pigments were obtained, filtered and washed The composite pigment prepared in the first experiment (Table VIII) consisted of 80 % PDM clay and 20 % calcium silicate In the second experiment (Table IX), the Ultra White 90 clay an component was varied from 60-90 o and the calcium silicate component from 40-10 %o The pigments were incorporated into standard TAP Pl handsheets as a filler material and the optical properties were measured (All percentages are by weight) TABLE VIII.
Composite Pigment-Optical Comparisons PDM Filler Clay-Continuous Process Pigment Composition 0/ /O Control PDM Clay Brightness Opacity 79.0 79.3 71.5 75.3 PDM Clay Clay Ca Sil Clay l Ca Sil J Clay \ Ca Sil J Clay Ca Sil J 80.0 80.8 81.8 81.1 82.1 79.5 77.6 82.1 77.2 82.4 9.86 4.67 8.90 4.94 10.11 179 257 277 236 259 TABLE IX.
Composite Pigment-Optical Comparisons Ultra White 90 Clay-Continuous Process Pigment Scattering Composition Filler Coefficient % Brightness Opacity % S’ Control 78 5 70 3 UW 90 Clay 79 2 74 4 5 30 157 Clay Ca Sla 81 0 77 5 5 25 278 Ca Silf Clay 0 Ca Sila} 81 0 78 0 5 23 300 Ca Sil} Clay Clayl 82 2 80 3 5 42 396 Ca Sil J’ Each of the composite pigments observed in Tables VIII and IX were prepared with an agitation rate in the in-line mixer of 1700 rpm and incorporated in handsheets at the levels shown Samples collected at lower speeds did not show any significant changes in optical performance Two washes of the filter cake were performed on each batch using 16 parts water per I part pigment to remove up to 93 %o by weight of the sodium salt by-product produced during the reaction A comparison of the data obtained from the pigments prepared in Example II with the data obtained from the pigments prepared in Example I shows that the product prepared in the continuous process apparatus produced about the same Filler 0 ‘ /0 Scattering Coefficient So 0.50 5.02 1,564,867 results as the product produced with the bench scale Waring blender apparatus.
EXAMPLE III.
Composite pigments using as base clay materials Ultra White 90 clay and Nuclay were produced according to the continuous process described in Example II except that no p H adjustment was made The pigments produced were 5 incorporated in size press formulations and applied to a Westvaco Corporation basestock in web form A gate roll size press apparatus was used to apply the formulations to produce a 61 lb/ream envelope paper and a 48 lb/ream Clear Spring offset grade, both of which are commercial products of Westvaco Corporation For the purpose of this Example, a ream is defined as 500 sheets of paper measuring 10 x 38 inches The sizepress formulations were prepared with composite pigments containing 80 % UW 90 clay and 20 % Ca Sil, 80 % Nuclay and 20 % Ca Sil and 90 % UW 90 clay and 10 % Ca Sil The formulations containing the 80/20 composite pigments each comprised by weight about 40 parts starch and 60 parts pigment, while the formulations containing the 90/10 composite pigment contained by 15 weight about 35 parts starch and 65 parts pigment The component parts were slurried in water to a solids content of from 22-28 % The gate roll size press apparatus was operated with an applicator roll speed of 400 fpm and adjusted to give a pick up of less than 5 lb/ream After sizing, the web was dried and sheeted, with sample sheets being analyzed to determine their optical properties and 20 printability The results are set forth in Table X.
TABLE X.
Optical and Strength Comparisons Sizepressed Envelope Grade Pigment Coat Wax Composition Weight Pick % (lbs/ream) Brightness Opacity Wire Basestock 80 4 92 2 9 UW 90 Clay 4 3 79 5 92 0 14 + Nuclay 4 7 79 9 92 5 14 + UW 90 ‘} 4 8 81 5 93 6 12 Ca Sil j Nuclay 5 5 81 0 93 6 13 Ca Sil f UW 90} 4 8 80 9 93 1 14 + Ca Sil J Clear Spring Offset Grade Basestock 81 4 89 0 12 U Wi} 2 7 82 2 90 1 13 Ca Sil J Nuclay} 2 7 81 6 90 2 14 + Ca Sil f UW 90 2 1 82 2 89 7 13 Ca Sil The data in Table X show that optical improvements achieved with the composite pigment were significant as compared with the control formulations containing only Nuclay or Ultra White 90 clay Examination of the sizepressed 25 paper samples also showed that the formulations containing the composite 1,564,867 13 1,564,867 13 pigments produced a more uniform surface The composite pigment formulations also appeared to wet more uniformly than the control when a drop of water was applied Wax pick, a measure of the pick strength of the paper in offset printing, did not decrease any significant amount with the application of the composite pigment formulation These results were confirmed with laboratory print tests 5 where no differences in picking tendency were observed between the paper sized with the composite pigment formulations and the paper sized with the control formulations In addition, ink show-through was greatly reduced with the composite pigment formulations while the sheet appearance was greatly improved.
The composite pigment of the present invention is also useful in coating 10 formulations for paper Ti O 2 pigment is generally used in paper coatings to produce sheets having high opacity and brightness and because of the good hiding power of the pigment.
However, Ti O 2 is a fairly abrasive material (typical Valley abrasion of about 25 is mg) and it is expensive Thus, replacements for Ti O 2 in paper coatings are 15 constantly being sought.
EXAMPLE IV.
Coating formulations were prepared in which the conventionally used Ti O 2 was replaced with an equal weight amount of the composite pigment of the present invention For this purpose, a composite pigment consisting of 90 % Ultra White 90 20 clay and 10 % calcium silicate was produced according to the continuous process disclosed in Example II Three coating formulations were prepared including acontrol coating containing no Ti O 2, a second coating comprising 5 % Ti O 2 and a third experimental coating color comprising 5 %O of the 90/10 composite pigment, all percentages by weight Each coating formulation also contained clay, chalk, starch 25 and a latex prepared according to a standard formula The control coating had a Brookfield viscosity of 14,000 cps at 60 4 % solids while the composite pigment coating had a Brookfield of 20,000 cps at 59 8 % solids The coatings were applied by trailing blade to a 38 lb/ream Field Web Offset basestock (Westvaco
Corporation product) at six different blade loadings to produce coat weights 30 ranging from 5 to 13 lbs/ream The coated basestocks were dried, calendered 3 nips at 600 pli and 1500 F and then sheeted to obtain samples from which the data in Table XI were obtained.
TABLE XI.
Composite Pigment/Ti O 2 Coating Formulations Optical and Printability Comparisons Coat Weight Bulk Wax #/ream Smoothness Gloss Opacity Birghtness Pick % Ti O 2 5.2 928 51 87 1 74 3 7 6.6 1088 57 87 7 74 8 7 7.9 1224 59 88 7 75 5 7 9.1 1296 61 89 1 75 8 7 9.9 1335 62 89 5 76 1 7 12.0 1467 66 90 5 76 4 7 Composite Pigment 5 % 5.0 1057 48 86 5 73 6 7 6.1 1329 54 87 1 73 8 7 7.6 1330 57 87 7 74.4 7 14 1,564,867 14 TABLE XI contd.
Composite Pigment/Ti O 2 Coating Formulations Optical and Printability Comparisons Coat Weight Bulk Wax #/ream Smoothness Gloss Opacity Birghtness Pick Composite Pigment 5 ,’ 9.4 1253 58 88 7 74 7 7 10.8 1561 58 89 6 74 9 6 12.8 1174 55 90 4 75 8 6 Control 5.5 867 47 86 2 73 3 8 7.0 1082 55 87 3 73 7 8 8.0 1182 56 87 8 74 0 7 9.4 1357 58 88 3 74 3 7 9.9 1381 59 88 9 74 4 7 13.1 1312 58 89 8 74 7 7 As may be observed from the data in Table XI, a coating formulation in which Ti O 2 was replaced with an equal weight amount of a 90/10 composite pigment produced coated paper having optical properties (opacity and brightness) that fell about midway between those of the paper coated with the standard formulation 5 containing Ti O, and the control formulation without Ti O 2 Gloss measurements for the composite pigment formulation were slightly lower than those obtained with the standard formulation while the smoothness increased Based on other data (not disclosed), the Valley abrasion of the composite pigment used in Example IV would range from 8-12 mg, or lower than that of Ti O 2, while the cost advantage of using 10 the composite pigment would be substantial, i e, less than the cost of Ti O 2.
Accordingly it may be seen that the composite pigment of the present invention offers a good choice for the replacement of Ti O 2 in paper coating formulations.
Claims (14)
WHAT WE CLAIM IS:-
1 A method of preparing a composite white pigment of improved optical 15 efficiency consisting of a clay component and a metal silicate component, said method comprising the steps of:
(a) forming an aqueous slurry of a clay having platelet-type structure; (b) blending into the clay slurry a water-soluble salt of a polyvalent metal; (c) metering into the clay/salt slurry at high shear a water-soluble alkali metal 20 silicate, thereby precipitating the silica in the form of spherical particles on the planar surfaces of the clay platelets, to form a composite pigment; (d) filtering the composite pigment from the slurry, and (e) washing the product.
2 The method of claim 1, wherein the clay component is a kaolin clay 25
3 The method of claim I or 2, wherein the water-soluble salt is of calcium, barium, zinc or magnesium.
4 The method as claimed in claim 3, wherein the water-soluble salt is a calcium salt.
5 The method of claim 4, wherein the calcium salt is calcium chloride 30
6 The method as claimed in any of claims 1-5, wherein the water-soluble alkali metal silicate is of sodium, potassium, or lithium.
7 The method of claim 6, wherein the water-soluble alkali metal silicate is sodium silicate.
8 The method as claimed in any of claims 1-7, wherein the amount of watersoluble salt added in step (b) is proportioned to obtain an excess over the stoichiometric quantity required to react with alkali metal silicate, and wherein the amount of alkali metal silicate added in step (c) is proportioned to obtain the desired weight ratio of clay to silicate in the final product.
9 The method as claimed in any of claims 1-8, wherein the precipitation reaction takes place at a temperature ranging between 20 and 85 CC.
10 The method as claimed in any of claims 1-9, wherein the p H of the slurry 10 containing the composite pigment is adjusted after step (c) to a value no lower than 4.
11 The method as claimed in any of claims 1-10, wherein at least 10 % by weight of the metal silicate component is precipitated on the clay platelets.
12 The method as claimed-in any of claims I-11, including the further step of 15 drying the filtered and washed pigment.
13 The pigment obtained as a product of carrying out the method claimed in any preceding claim.
14 Paper including the pigment claimed in claim 13.
K B WEATHERALD, Chartered Patent Agent.
Printed for Her Majesty’s Stationery Office by the Courier Press, Leamington Spa, 1980.
Published by the Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.
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Publication number
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JPS60500265A
(en)
*
1982-12-30
1985-02-28
ルユヒトラ−ト，ベルン
Paper or cardboard-like material
WO1987007884A1
(en)
*
1986-06-17
1987-12-30
J.M. Huber Corporation
Synthetic alkali metal alumino-silicates, methods and uses, compositions and their methods of preparation
US5171365A
(en)
*
1986-06-17
1992-12-15
J. M. Huber Corporation
Synthetic alkali metal alumino-silicates compositions and their methods of preparation
US5219660A
(en)
*
1987-06-01
1993-06-15
Wason Satish K
Precipitated encapsulated paper pigments and methods
US5312485A
(en)
*
1988-08-05
1994-05-17
J. M. Huber Corporation
Precipitated encapsulated paper pigments and methods
US5352287A
(en)
*
1988-08-05
1994-10-04
J. M. Huber Corporation
Precipitated encapsulated paper pigments and methods
FI100659B
(en)
1988-08-05
1998-01-30
Huber Corp J M
Paper pigment composite products and process for their manufacture
US5262239A
(en)
*
1988-08-05
1993-11-16
J. M. Huber Corporation
Precipitated encapsulated paper pigments and methods
WO1991005604A1
(en)
*
1989-10-12
1991-05-02
Industrial Progress, Inc.
Structural aggregate pigments
EP0512986A4
(en)
*
1990-01-31
1993-04-07
Industrial Progress, Inc.
Functional complex microgels with rapid formation kinetics
US5203918A
(en)
*
1990-06-04
1993-04-20
Ecc America Inc.
Method for forming aggregated kaolin pigment
US5336311A
(en)
*
1992-07-07
1994-08-09
Nord Kaolin Company
Cationic pigments
EP1019454B1
(en)
*
1997-01-09
2001-11-07
Ciba SC Holding AG
Composite pigment
US6726807B1
(en)
1999-08-26
2004-04-27
G.R. International, Inc. (A Washington Corporation)
Multi-phase calcium silicate hydrates, methods for their preparation, and improved paper and pigment products produced therewith
US6403059B1
(en)
*
2000-08-18
2002-06-11
J. M. Huber Corporation
Methods of making dentifrice compositions and products thereof
US6419174B1
(en)
*
2000-08-18
2002-07-16
J. M. Huber Corporation
Abrasive compositions and methods for making same
US7048900B2
(en)
*
2001-01-31
2006-05-23
G.R. International, Inc.
Method and apparatus for production of precipitated calcium carbonate and silicate compounds in common process equipment
US20030094253A1
(en)
*
2001-06-19
2003-05-22
Torras Joseph H.
Sodium silicate treatment for printing papers
EP3070071A1
(en)
*
2015-03-16
2016-09-21
Construction Research & Technology GmbH
A process for forming roughened micron size anisotropic platelets
Family Cites Families (9)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US2296637A
(en)
*
1938-12-08
1942-09-22
Du Pont
High surface hiding pigment material and process of making the same
US2259481A
(en)
*
1939-04-24
1941-10-21
Glidden Co
Treated pigments and method of making
US2259482A
(en)
*
1939-04-24
1941-10-21
Glidden Co
Method of treating pigments and products produced thereby
US2913419A
(en)
*
1956-04-18
1959-11-17
Du Pont
Chemical process and composition
US2885366A
(en)
*
1956-06-28
1959-05-05
Du Pont
Product comprising a skin of dense, hydrated amorphous silica bound upon a core of another solid material and process of making same
FR1175443A
(en)
*
1957-03-28
1959-03-26
Thann Fab Prod Chem
Organophilic and hydrophobic pigments and method for their preparation
US3433704A
(en)
*
1965-12-16
1969-03-18
Engelhard Min & Chem
Attapulgite clay paper filler and method of forming newsprint therewith
FR1485714A
(en)
*
1966-05-12
1967-06-23
Fr Des Silicates Speciaux Sifr
Combined pigments
GB1380361A
(en)
*
1971-02-10
1975-01-15
Commw Scient Ind Res Org
Mineral surfaces
1976
1976-03-19
US
US05/668,436
patent/US4026721A/en
not_active
Expired – Lifetime
1977
1977-03-09
GB
GB9890/77A
patent/GB1564867A/en
not_active
Expired
1977-03-17
ES
ES456973A
patent/ES456973A1/en
not_active
Expired
1977-03-18
FR
FR7708275A
patent/FR2344604A1/en
not_active
Withdrawn
1977-03-18
DE
DE2711910A
patent/DE2711910C2/en
not_active
Expired
1977-03-19
JP
JP3099277A
patent/JPS52115831A/en
active
Granted
Also Published As
Publication number
Publication date
DE2711910C2
(en)
1983-10-27
ES456973A1
(en)
1978-10-01
US4026721A
(en)
1977-05-31
FR2344604A1
(en)
1977-10-14
JPS52115831A
(en)
1977-09-28
JPS547296B2
(en)
1979-04-05
DE2711910A1
(en)
1977-09-22
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Legal Events
Date
Code
Title
Description
1980-07-02
PS
Patent sealed [section 19, patents act 1949]
1983-10-26
PCNP
Patent ceased through non-payment of renewal fee
