U.S. patent application number 14/704956 was filed with the patent office on 2016-01-28 for aluminum phosphate or polyphosphate compositions.
The applicant listed for this patent is Bunge Amorphic Solutions LLC. Invention is credited to Cesar Augusto Sales Barbosa, Melissa Braga, Fernando Galembeck.
Application Number | 20160024271 14/704956 |
Document ID | / |
Family ID | 40957304 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160024271 |
Kind Code |
A1 |
Galembeck; Fernando ; et
al. |
January 28, 2016 |
ALUMINUM PHOSPHATE OR POLYPHOSPHATE COMPOSITIONS
Abstract
Slurry composition comprising amorphous aluminum phosphate,
polyphosphate orthophosphate, metaphosphate and/or combination
thereof and a dispersant are described. In certain embodiments, the
polyphosphate orthophosphate and/or metaphosphate concentration is
about 40 to about 70 weight % and the dispersant concentration is
less than about 3.5 weight % based on the total weight of the
slurry. In one embodiment, the composition is useful is paints,
varnishes, printing inks, papers and plastics. The compositions can
be used as a substitute for titanium dioxide in various
applications.
Inventors: |
Galembeck; Fernando;
(Campinas, BR) ; Barbosa; Cesar Augusto Sales;
(Campinas, BR) ; Braga; Melissa; (Campinas,
BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bunge Amorphic Solutions LLC |
White Plains |
NY |
US |
|
|
Family ID: |
40957304 |
Appl. No.: |
14/704956 |
Filed: |
May 5, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12368867 |
Feb 10, 2009 |
9023145 |
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14704956 |
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61065493 |
Feb 12, 2008 |
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Current U.S.
Class: |
524/417 ;
106/401 |
Current CPC
Class: |
C01B 25/36 20130101;
C09D 7/45 20180101; C09D 11/037 20130101; C08K 2003/327 20130101;
C01P 2006/10 20130101; C01B 25/40 20130101; C08K 2003/324 20130101;
C09D 7/67 20180101; C01P 2006/22 20130101; B82Y 30/00 20130101;
C01P 2004/64 20130101; C09C 1/40 20130101; C09D 5/028 20130101;
C08K 3/32 20130101 |
International
Class: |
C08K 3/32 20060101
C08K003/32; C09D 7/12 20060101 C09D007/12 |
Claims
1-35. (canceled)
36. A slurry comprising amorphous aluminum phosphate particles and
a dispersant, wherein the aluminum phosphate concentration is about
40 to about 70 weight % and the dispersant concentration is from
about 0.1 to 3.5 weight % based on total weight of the slurry, and
wherein the dispersant is selected from the group consisting of
tetrasodium pyrophosphate, pentasodium triphosphate, trisodium
phosphate dodecahydrate, tetrapotassium pyrophosphate, sodium
potassium triphosphate, a borate dispersant, a silicate dispersant,
and combinations thereof.
37. The slurry as recited in claim 36, wherein the dispersant
concentration is less than about 2 weight % based on the total
weight of the slurry.
38. The slurry as recited in claim 36, wherein the dispersant
concentration is less than about 1 weight % based on the total
weight of the slurry.
39. The slurry as recited in claim 36, wherein the dispersant
concentration is about 0.1 to about 1 weight % based on the total
weight of the slurry.
40. The slurry as recited in claim 36, wherein the dispersant
concentration is about 0.25 to about 1 weight % based on the total
weight of the slurry.
41. The slurry as recited in claim 36, wherein the dispersant
concentration is about 0.25, 0.5, 0.75 or 1 weight % based on the
total weight of the slurry.
42. The slurry as recited in claim 36, wherein the aluminum
phosphate concentration is about 50 to about 60 weight % based on
the total weight of the slurry.
43. The slurry as recited claim 36, wherein the aluminum phosphate
concentration is about 50, 51, 52, 53, 54, 55 or 56 weight % based
on the total weight of the slurry.
44. The slurry as recited in claim 36 wherein the slurry has a
viscosity of from about 300 cPs to about 3,500 cPs measured from
100 s.sup.-1 to 500 s.sup.-1 shear rates.
45. The slurry as recited in claim 36, wherein the dispersant is
selected from the group consisting of tetrasodium pyrophosphate,
pentasodium triphosphate, trisodium phosphate dodecahydrate,
tetrapotassium pyrophosphate, sodium potassium triphosphate.
46. The slurry as recited in claim 45 wherein the wherein the
aluminum phosphate concentration is about 51 weight % based on the
total weight of the slurry, and the slurry has a viscosity of
approximately 576 cPs to 2,774 cPs at 100 s.sup.-1, 462 cPs to
1,396 cPs at 300 s.sup.-1, and 376 cPs to 1,097 cPs at 500
s.sup.-1.
47. The slurry as recited in claim 45, wherein the aluminum
phosphate concentration is about 51 weight % based on the total
weight of the slurry, the dispersant is pentasodium triphosphate,
and the slurry has a viscosity from about 576 cPs to 1,963 cPs
measured at 100 s.sup.-1.
48. The slurry as recited in claim 45, wherein the aluminum
phosphate concentration is about 51 weight % based on the total
weight of the slurry, the dispersant is pentasodium triphosphate,
and the slurry has a viscosity from about 462 cPs to 1,174 cPs
measured at 300 s.sup.-1.
49. The slurry as recited in claim 45, wherein the aluminum
phosphate concentration is about 51 weight % based on the total
weight of the slurry, the dispersant is pentasodium triphosphate,
and the slurry has viscosity from about 376 cPs to 966 cPs measured
at 500 s.sup.-1.
50. The slurry as recited in claim 45 that is substantially free of
titanium dioxide.
51. A coating composition comprising the slurry as recited in claim
36 as combined with a binding polymer.
52. A slurry as recited in claim 36 wherein the slurry comprises
greater than 51 weight % of the amorphous aluminum phosphate, and
wherein the dispersant is pentasodium triphosphate.
53. A slurry as recited in claim 52 wherein the slurry comprises
53.85 to 55.71 weight % of the amorphous aluminum phosphate.
54. The slurry as recited in claim 52 wherein the dispersant
concentration is between 0.98 to 1.51 weight %, and wherein the
slurry and has a viscosity of from 1,308 cPs to 5,623 at 100
s.sup.-1.
55. The slurry as recited in claim 52 wherein the dispersant
concentration is between 0.98 to 1.51 weight %, and wherein the
slurry has a viscosity of from about 914 to 2,405 cPs at 300
s.sup.-1.
56. The slurry as recited in claim 52 wherein the dispersant
concentration is between 0.98 to 1.51 weight %, and wherein the
slurry has a viscosity of from about 757 to 1,687 cPs at 500
s.sup.-1.
57. A slurry comprising an opacifying pigment formed of amorphous
aluminum phosphate particles and a dispersant, wherein the
dispersant is selected from the group consisting of a borate
dispersant, a silicate dispersant, and combinations thereof.
58. A slurry comprising an opacifying pigment formed of amorphous
aluminum phosphate particles and a dispersant that is pentasodium
triphosphate.
59. A method for making a stable aluminum phosphate slurry
composition comprising: a) mixing amorphous aluminum phosphate
particles with a dispersant selected from the group consisting of
tetrasodium pyrophosphate, pentasodium triphosphate, trisodium
phosphate dodecahydrate, tetrapotassium pyrophosphate, sodium
potassium triphosphate, a borate dispersant, a silicate dispersant,
and combinations thereof; and b) stirring with a disperser at
stirring velocity of 500 to 2,000 rpm.
60. The method as recited in claim 59 wherein the aluminum
phosphate concentration is about 40 to about 70 weight %, and the
dispersant concentration is from about 0.1 to 3.5 weight % based on
total weight of the slurry.
61. The method as recited in claim 59 wherein the slurry has a
viscosity of from about 300 cPs to about 3,500 cPs measured from
100 s.sup.-1 to 500 s.sup.-1 shear rates.
62. The method as recited in claim 59 wherein during the step of
mixing, a stock slurry comprising about 30 weight % amorphous
aluminum phosphate based on total weight of the slurry is combined
with the amorphous aluminum particles and the dispersant.
63. The method as recited in claim 59 wherein the amorphous
aluminum orthophosphate concentration is about 51 weight % based on
the total weight of the slurry, and wherein the dispersants are
selected from the group consisting of tetrasodium pyrophosphate,
pentasodium triphosphate, trisodium phosphate dodecahydrate,
tetrapotassium pyrophosphate, sodium potassium triphosphate.
64. The method as recited in claim 63 wherein the slurry has a
viscosity of approximately 576 cPs to 2,774 cPs at 100 s.sup.-1,
462 cPs to 1,396 cPs at 300 s.sup.-1, and 376 cPs to 1,097 cPs at
500 s.sup.-1.
65. A method for making a coating composition comprising combining
the slurry as made according to claim 59 and combining the slurry
with a binder polymer.
Description
PRIOR RELATED APPLICATIONS
[0001] This patent application is a continuation of and claims
priority to U.S. patent application Ser. No. 12/368,867, filed Feb.
10, 2009, now U.S. Pat. No. 9,023,145 issued May 5, 2015, which
claims priority to U.S. Provisional Patent Application No.
61/065,493, filed Feb. 12, 2008, which applications are herein
incorporated by reference in their entirety.
FIELD OF INVENTION
[0002] Provided herein are compositions in form of a slurry
comprising aluminum phosphate, aluminum orthophosphate, aluminum
metaphosphate, aluminum polyphosphate or combinations thereof and a
dispersant. Aluminum phosphate, aluminum orthophosphate, aluminum
metaphosphate, or aluminum polyphosphate particles in the slurry
are characterized by one or more voids. Further provided are uses
of such compositions in paint and other applications.
BACKGROUND OF INVENTION
[0003] Titanium dioxide pigment is the most widely used white
pigment in paint due to its strong ability to backscatter visible
light, which is in turn dependent on its refractive index.
Substitutes for titanium dioxide have been sought, but the
refractive indexes of the anatase and rutile forms of titanium
dioxide are much higher than those of any other white powder, due
to structural reasons.
[0004] Titanium dioxide pigments are insoluble in coating vehicles
in which they are dispersed. The performance properties of such
titanium dioxide pigments, including its physical and chemical
characteristics, are determined by the particle size of the pigment
and the chemical composition of its surface. The decorative and
functional abilities of titanium dioxide are due to its scattering
power that make it a highly desirable pigment. However, titanium
dioxide is known to be an expensive pigment to manufacture.
Accordingly, there is a need for a more affordable substitute for
titanium dioxide as a pigment.
[0005] Amorphous aluminum phosphate particles are reported in the
literature as a substitute for titanium dioxide white pigment in
paints and other applications. For example, see, U.S. patent
publication nos. 2006/0211798 and 2006/0045831 and 2008/0038556.
The disclosures of these patent applications is incorporated by
reference in their entirety herein.
[0006] There is a continuing need to develop efficient and
cost-effective compositions of amorphous aluminum phosphate.
SUMMARY OF THE INVENTION
[0007] Provided herein is a composition in form of a slurry
comprising aluminum phosphate, aluminum orthophosphate, aluminum
metaphosphate, aluminum polyphosphate particles or a mixture
thereof and a dispersant. Also provided is a process for making the
compositions. The aluminum phosphate, aluminum orthophosphate,
aluminum metaphosphate or aluminum polyphosphate particles in the
slurry are characterized by one or more voids per particle of
amorphous aluminum phosphate, aluminum metaphosphate, aluminum
orthophosphate or aluminum polyphosphate when in powder form. In
one embodiment, the aluminum phosphate, aluminum metaphosphate,
aluminum orthophosphate or aluminum polyphosphate particles in the
slurry are characterized by one to four voids per particle of
amorphous aluminum phosphate, aluminum metaphosphate, aluminum
orthophosphate or aluminum polyphosphate when in powder form. In
certain embodiments, the amorphous aluminum phosphate, aluminum
metaphosphate, aluminum orthophosphate or aluminum polyphosphate in
the slurry is characterized by a skeletal density of between about
1.95 and 2.50 grams per cubic centimeter. In certain embodiments,
amorphous aluminum phosphate, aluminum metaphosphate, aluminum
orthophosphate or aluminum polyphosphate in the slurry has a
phosphorus to aluminum mole ratio of about 0.5 to 1.75, 0.65 to
1.75, 0.5 to 1.5 or 0.8 to 1.3. In one embodiment, amorphous
aluminum phosphate, aluminum metaphosphate, aluminum orthophosphate
or aluminum polyphosphate in the slurry has a phosphorus to
aluminum mole ratio of about 0.5 to 1.5 or 0.8 to 1.3. In powder
form, the amorphous aluminum phosphate, aluminum metaphosphate,
aluminum orthophosphate or aluminum polyphosphate may comprise an
average individual particle radius size of between about 5 and 80
nanometers. In certain embodiments, the amorphous aluminum
phosphate, aluminum metaphosphate, aluminum orthophosphate or
aluminum polyphosphate may comprise an average individual particle
radius size of between about 10 to 80, 20 to 80, 30 to 80, 10 to
50, or 10 to 40 nanometers, when in powder form.
[0008] Without being bound to any particular theory, it is believed
that the dispersants in the slurry compositions allow to achieve
higher concentrations of non-volatiles, for example, in certain
embodiments, more than about 40 or 50 weight % non-volatiles based
on the total weight of the slurry or in other embodiments or more
than about 40 or 50 weight % aluminum phosphate, aluminum
metaphosphate, aluminum orthophosphate or aluminum polyphosphate,
or combination thereof, based on the total weight of the slurry. In
certain aspects, the slurry compositions comprising dispersants
exist as viscous liquids with a viscosity suitable for the desired
applications, for example, use of the slurry compositions in
paints. In certain embodiments, the dispersions of aluminum
phosphate, aluminum metaphosphate, aluminum orthophosphate or
aluminum polyphosphate without dispersants, exhibit low viscosity
at lower non-volatile concentrations, for example, lower than or
about 35 weight % non-volatiles based on the total weight of the
slurry. In other embodiments, the dispersions of aluminum
phosphate, aluminum metaphosphate, aluminum orthophosphate or
aluminum polyphosphate without dispersants, exhibit high viscosity
at higher non-volatile concentrations, for example, higher than or
about 35 weight % non-volatiles based on the total weight of the
slurry. Such highly viscous slurry is not suitable for use in, for
example, paint applications and other applications. In certain
embodiments, slurries comprising lower concentrations of
non-volatiles or lower concentrations of aluminum phosphate,
aluminum metaphosphate, aluminum orthophosphate or aluminum
polyphosphate and combinations thereof, settle thereby producing
hard-packed sediment that is not easily dispersed.
[0009] In certain embodiments, the amorphous aluminum phosphate,
aluminum metaphosphate, aluminum orthophosphate or aluminum
polyphosphate in the slurry further comprises an ion, such as
sodium, lithium, calcium, potassium, borate, ammonium or a
combination thereof. In certain embodiments, the ion is selected
from sodium, potassium and lithium ion. In one embodiment, the ion
is sodium ion. In certain embodiment, the slurry comprises sodium
aluminum phosphate, sodium aluminum metaphosphate, sodium aluminum
orthophosphate or sodium aluminum polyphosphate or a mixture
thereof and a dispersant or a mixture of dispersants.
[0010] The slurry comprising aluminum phosphate, aluminum
metaphosphate, aluminum orthophosphate or aluminum polyphosphate or
a mixture thereof may be used as an ingredient in a paint. In
certain embodiments, the slurry is used as a substitute (in part or
in whole) for titanium dioxide. The slurry may also be used as an
ingredient in a varnish, printing ink, paper or plastic.
DESCRIPTION OF DRAWINGS
[0011] FIG. 1: Effects of dispersant type and concentration on 51%
aluminum phosphate slurry viscosities at 100 s.sup.-1. The dashed
lines indicate the interval of low viscosity without sedimentation
(900-1150 cPs).
[0012] FIG. 2: Illustrates effects of dispersant type and
concentration on 51% aluminum phosphate slurry viscosities at 100
s.sup.-1 after 3 weeks at room temperature (24.+-.2.degree. C).
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0013] In the following description, all numbers disclosed herein
are approximate values, regardless whether the word "about" or
"approximate" is used in connection therewith. They may vary by 1
percent, 2 percent, 5 percent, or sometimes, 10 to 20 percent.
Whenever a numerical range with a lower limit, R.sup.L and an upper
limit, R.sup.U, is disclosed, any number falling within the range
is specifically disclosed. In particular, the following numbers
within the range are specifically disclosed:
R=R.sup.L+k*(R.sup.U-R.sup.L), wherein k is a variable ranging from
1 percent to 100 percent with a 1 percent increment, i.e., k is 1
percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50
percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97
percent, 98 percent, 99 percent, or 100 percent. Moreover, any
numerical range defined by two R numbers as defined in the above is
also specifically disclosed.
[0014] Provided herein is an aluminum phosphate composition in a
slurry form comprising aluminum phosphate, aluminum orthophosphate,
aluminum metaphosphate or aluminum polyphosphate, or a mixture
thereof and a dispersant. The term "aluminum phosphate" as used
herein, is meant to include aluminum phosphate, aluminum
orthophosphate, aluminum metaphosphate or aluminum polyphosphate,
and mixtures thereof.
[0015] The term "slurry" as used herein refers to a homogeneous
suspension or dispersion comprising non-volatile particles,
including aluminum phosphate, aluminum orthophosphate, aluminum
metaphosphate or aluminum polyphosphate, and/or mixtures thereof in
a solvent. In certain embodiments, the solvent comprises or is
water. In certain embodiments, the slurry comprises more than 30,
40, 50, 60 or 70 weight % non-volatile particles, including
aluminum phosphate, aluminum orthophosphate, aluminum metaphosphate
or aluminum polyphosphate, and/or mixtures thereof based on the
total weight of the slurry. In some embodiments, the particles
suspended or dispersed in a solvent (such as water) form a
colloidal solution, which is stable over a relatively long period
of time. A colloidal solution is a colloid that has a continuous
liquid phase in which a solid is suspended in a liquid.
[0016] The term "void" referred to herein is generally synonymous
with the term "hollow particle," and is also described herein as a
"closed void." The void (or closed void or hollow particle) is part
of a core and shell structure of the aluminum phosphate mixture.
The voids may be observed and/or characterized using either
transmission or scanning electron microscopes ("TEMs" or "SEMs").
The use of TEMs or SEMs are well known to those of skill in the
art. Generally, optical microscopy is limited, by the wavelength of
light, to resolutions in the range of a hundred, and usually
hundreds, of nanometers. TEMs and SEMs do not have this limitation
and are able to attain a considerably higher resolution, in the
range of a few nanometers. An optical microscope uses optical
lenses to focus light waves by bending them, while an electron
microscope uses electromagnetic lenses to focus beams of electrons
by bending them. Beams of electrons provide great advantages over
beams of light both in control of magnification levels and in the
clarity of the image that can be produced. Scanning electron
microscopes complement transmission electron microscopes in that
they provide a tool to obtain the three dimensional image of the
surface of a sample.
[0017] Amorphous (i.e., non-crystalline) solids exhibit differences
from their crystalline counterparts with a similar composition, and
such differences may yield beneficial properties. For example, such
differences may include one or more of the following: (i) the
non-crystalline solids do not diffract x-rays at sharply defined
angles but may produce a broad scattering halo instead; (ii) the
non-crystalline solids do not have well defined stoichiometry, thus
they can cover a broad range of chemical compositions; (iii) the
variability of chemical composition includes the possibility of
incorporation of ionic constituents other than aluminum and
phosphate ions; (iv) as amorphous solids are thermodynamically
meta-stable, they may demonstrate a tendency to undergo spontaneous
morphological, chemical and structural changes; and (v) the
chemical composition of crystalline particle surface is highly
uniform while the chemical composition of surface of amorphous
particles may show large or small differences, either abrupt or
gradual. In addition, while particles of crystalline solids tend to
grow by the well-known mechanism of Ostwald ripening,
non-crystalline particles may expand or swell and shrink (de-swell)
by water sorption and desorption, forming a gel-like or plastic
material that is easily deformed when subjected to shearing,
compression or capillary forces.
[0018] The aluminum phosphate particles in the slurry are
characterized by one or more voids per particle of amorphous
aluminum phosphate when in powder form. In one embodiment, the
aluminum phosphate particles in the slurry are characterized by one
to four voids per particle of amorphous aluminum phosphate when in
powder form.
[0019] In certain embodiments, the aluminum phosphate particles in
the slurry are characterized by a skeletal density of about
1.723-2.40 g/cm.sup.3. In one embodiment, the skeletal density is
less than 2.40 g/cm.sup.3. In another embodiment, the skeletal
density is less than 2.30 g/cm.sup.3. In another embodiment, the
skeletal density is less than 2.10 g/cm.sup.3. In yet another
embodiment, the skeletal density is less than 1.99 g/cm.sup.3. In
one embodiment, the amorphous aluminum phosphate in the slurry is
characterized by a skeletal density of about 1.95, 1.98, 2.00, or
2.25 grams per cubic centimeter.
[0020] In one embodiment, amorphous aluminum phosphate in the
slurry has a phosphorus to aluminum mole ratio of about 0.5 to 1.5.
In another embodiment, amorphous aluminum phosphate in the slurry
has a phosphorus to aluminum mole ratio of about 0.8 to 1.3. In
certain embodiments, the phosphorus to aluminum mole ratio is about
0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5. In further
embodiments, the phosphorus to aluminum mole ratio is about 0.8,
0.9, 1.0, 1.1, 1.2 or 1.3.
[0021] In powder form, the amorphous aluminum phosphate may
comprise an average individual particle radius size of between
about 5 and 80 nanometers. In certain embodiments, the amorphous
aluminum phosphate may comprise an average individual particle
radius size of between about 5 and 40, 10 and 80, 10 and 40, 20 and
80 or 20 and 40 nanometers.
[0022] In certain embodiments, when the aluminum phosphate,
polyphosphate orthophosphate and/or metaphosphate is in powder
form, samples subjected to a differential scanning calorimetry test
will demonstrate two distinct endothermic peaks, the peaks
occurring generally between 90.degree. Celsius and 250.degree.
Celsius. In one embodiment, the first peak occurs at approximately
between the temperatures of approximately 96.degree. Celsius and
116.degree. Celsius, and the second peaks occurs at approximately
between the temperatures of 149.degree. Celsius and 189.degree.
Celsius. In another embodiment, the two peaks occur at
approximately 106.degree. Celsius and approximately 164.degree.
Celsius.
[0023] In certain embodiments, the slurry compositions provided
herein comprise from about 40% up to about 70% of non-volatiles by
weight measured according to ASTM D280. In certain embodiments, the
slurry comprises from about 40 wt % up to about 60 wt %
non-volatiles based on the total weight. In one embodiment, the
slurry comprises from about 50 wt % up to about 60 wt %
non-volatiles based on the total weight. In other embodiments, the
slurry comprises about 20, 30, 40, 45, 47, 48, 49, 50, 51, 52, 53,
54, 55, 56, 57, 58, 59 or 60 wt % or more of non-volatile solids
based on the total weight. In another embodiment, the slurry
comprises about 51, 53 or 58 wt % non-volatiles based on the total
weight.
[0024] In certain embodiments, the slurry comprises about 25 wt %
up to about 70 wt % aluminum phosphate by weight. In certain
embodiments, the slurry comprises about 40% up to about 60 wt %
aluminum phosphate based on the total weight. In one embodiment,
the slurry comprises from about 50 wt % up to about 60 wt %
aluminum phosphate based on the total weight. In another
embodiment, the slurry comprises 20, 30, 40, 45, 47, 48, 49, 50,
51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wt % or more of aluminum
phosphate based on the total weight. In one embodiment, the slurry
comprises about 51, 53 or 58 wt % aluminum phosphate based on the
total weight.
[0025] In certain embodiments, the aluminum phosphate slurry
provided herein has a viscosity ranging from about 300 cPs up to
about 3500 cPs measured at 100-500 s.sup.-1 shear rates (measured
using a Rheoterm 115 Rheometer, as described in Example 3). In
other embodiments, the aluminum phosphate slurry provided herein
has a viscosity ranging from about 550 cPs up to about 3000 cPs at
100 s.sup.-1 shear rate. In one embodiment, the aluminum phosphate
slurry provided herein has a viscosity ranging from about 900 cPs
up to about 1150 cPs at 100/sec shear rate. In another embodiment,
the aluminum phosphate slurry provided herein has a viscosity of
about 300, 400, 500, 600, 700, 800, 900, 1000, 1200, 1400, 1600,
1800, 2000, 2200, 2400, 2600, 2800 or 3000 cPs measured at 100-500
s.sup.-1 shear rates.
[0026] The dispersant in the aluminum phosphate slurry provided
herein is selected from phosphate dispersants, including inorganic
and organic phosphates, borate dispersants, silicate dispersants,
aluminate dispersants, any anionic or non-ionic surfactant or
soluble polymer or oligomer known to one of skill in the art and
any combination thereof.
[0027] In certain embodiments, the dispersant is selected from
tetrasodium pyrophosphate (TSPP), sodium hexametaphosphate,
pentasodium triphosphate, trisodium phosphate dodecahydrate,
tetrapotassium pyrophosphate (TKPP), sodium potassium triphosphate
or a combination thereof. In one embodiment, the dispersant
concentration in the aluminum phosphate slurry compositions
provided herein is less than about 3.5 weight % based on the total
weight of the slurry. In another embodiment, the dispersant
concentration in the aluminum phosphate slurry compositions
provided herein is less than about 3, 2.5, 2, 1.5 or 1 weight %
based on the total weight of the slurry.
[0028] In one embodiment, the aluminum phosphate slurry composition
provided herein comprises from about 50 weight % to about 60 weight
% aluminum phosphate and less than about 3, 2.5, 2, 1.5 or 1 weight
% dispersant based on the total weight of the slurry.
[0029] In one embodiment, the dispersant in the aluminum phosphate
slurry composition provided herein comprises trisodium phosphate
dodecahydrate in a concentration of about 0.10 to about 1.00 weight
% based on the total weight of the slurry. In another embodiment,
the dispersant in the aluminum phosphate slurry composition
provided herein comprises trisodium phosphate dodecahydrate in a
concentration of about 0.20 to about 0.75 weight % based on the
total weighty of the slurry. In yet another embodiment, the
dispersant in the aluminum phosphate slurry composition provided
herein comprises trisodium phosphate dodecahydrate in a
concentration of about 0.20 to about 0.50 weight % based on the
total weight of the slurry. In a further embodiment, the dispersant
in the aluminum phosphate slurry composition provided herein
comprises trisodium phosphate dodecahydrate in a concentration of
about 0.20, 0.22, 0.24, 0.27, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55,
0.60 or 0.75 weight % based on the total weight of the slurry.
[0030] In one embodiment, the aluminum phosphate slurry composition
provided herein comprises from about 50 weight % to about 60 weight
% aluminum phosphate and less than about 2 or less than about 1
weight % trisodium phosphate dodecahydrate based on the total
weight of the slurry. In one embodiment, the aluminum phosphate
slurry composition provided herein comprises from about 50 weight %
to about 60 weight % aluminum phosphate and about 0.20 weight % to
about 0.75 weight % trisodium phosphate dodecahydrate based on the
total weight of the slurry. In another embodiment, the aluminum
phosphate slurry composition provided herein comprises about 51, 53
or 58 weight % aluminum phosphate and about 0.24 or about 0.50
weight % trisodium phosphate dodecahydrate based on the total
weight of the slurry. In a further embodiment, the aluminum
phosphate slurry composition provided herein comprises about 51
weight % aluminum phosphate and about 0.24 or about 0.50 weight
trisodium phosphate dodecahydrate based on the total weight of the
slurry.
[0031] In another embodiment, the dispersant in the aluminum
phosphate slurry composition provided herein comprises tetrasodium
pyrophosphate in a concentration of about 0.10 to about 1.50 weight
% based on the total weight of the slurry. In one embodiment, the
dispersant in the aluminum phosphate slurry composition provided
herein comprises tetrasodium pyrophosphate in a concentration of
about 0.25 to about 1.00 weight % based on the total weight of the
slurry. In another embodiment, the dispersant in the aluminum
phosphate slurry composition provided herein comprises tetrasodium
pyrophosphate in a concentration of about 0.25, 0.27, 0.30, 0.35,
0.45, 0.50, 0.75, 0.97 or 1.00 weight % based on the total weight
of the slurry.
[0032] In one embodiment, the aluminum phosphate slurry composition
provided herein comprises from about 50 weight % to about 60 weight
% aluminum phosphate and less than about 2 or less than about 1
weight % tetrasodium pyrophosphate (TSPP) based on the total weight
of the slurry. In one embodiment, the aluminum phosphate slurry
composition provided herein comprises from about 50 weight % to
about 60 weight % aluminum phosphate and about 0.2 weight % to
about 1.00 weight % tetrasodium pyrophosphate based on the total
weight of the slurry. In another embodiment, the aluminum phosphate
slurry composition provided herein comprises about 51, 53 or 58
weight % aluminum phosphate and about 0.25, 0.27, 0.50, 0.97 or
1.00 weight % tetrasodium pyrophosphate based on the total weight
of the slurry. In yet another embodiment, the aluminum phosphate
slurry composition provided herein comprises about 51 weight %
aluminum phosphate and about 0.25, 0.50 or about 1.00 weight %
tetrasodium pyrophosphate based on the total weight of the
slurry.
[0033] In one embodiment, the dispersant in the aluminum phosphate
slurry composition provided herein comprises pentasodium
triphosphate in a concentration of about 0.10 to about 3.00 weight
% based on the total weight of the slurry. In another embodiment,
the dispersant in the aluminum phosphate slurry composition
provided herein comprises pentasodium triphosphate in a
concentration of about 0.10 to about 1.60 weight % based on the
total weight of the slurry. In yet another embodiment, the
dispersant in the aluminum phosphate slurry composition provided
herein comprises pentasodium triphosphate in a concentration of
about 0.25 to about 1.00 weight % based on the total weight of the
slurry. In a further embodiment, the dispersant in the aluminum
phosphate slurry composition provided herein comprises pentasodium
triphosphate in a concentration of about 0.25, 0.30, 0.50, 0.53,
0.75, 0.99, 1.00 or 1.50 weight % based on the total weight of the
slurry.
[0034] In one embodiment, the aluminum phosphate slurry composition
provided herein comprises from about 50 weight % to about 60 weight
% aluminum phosphate and less than about 2, less than about 1.5 or
less than about 1 weight % pentasodium triphosphate based on the
total weight of the slurry. In one embodiment, the aluminum
phosphate slurry composition provided herein comprises from about
50 weight % to about 60 weight % aluminum phosphate and about 0.10
weight % to about 1.50 weight % pentasodium triphosphate based on
the total weight of the slurry. In another embodiment, the aluminum
phosphate slurry composition provided herein comprises about 51, 53
or 58 weight % aluminum phosphate and about 0.50 weight %
pentasodium triphosphate based on the total weight of the slurry.
In yet another embodiment, the aluminum phosphate slurry
composition provided herein comprises shout 51 weight % aluminum
phosphate and about 0.50 weight % pentasodium triphosphate based on
the total weight of the slurry.
[0035] In one embodiment, the dispersant in the aluminum phosphate
slurry composition provided herein comprises tetrapotassium
pyrophosphate (TKPP) in a concentration of about 0.10 to about 2.00
weight % based on the total weight of the slurry. In another
embodiment, the dispersant in the aluminum phosphate slurry
composition provided herein comprises tetrapotassium pyrophosphate
in a concentration of about 0.10 to about 1.75 weight % based on
the total weight of the slurry. In yet another embodiment, the
dispersant in the aluminum phosphate slurry composition provided
herein comprises tetrapotassium pyrophosphate in a concentration of
about 0.25 to about 1.55 weight % based on the total weight of the
slurry. In a further embodiment, the dispersant in the aluminum
phosphate slurry composition provided herein comprises
tetrapotassium pyrophosphate in a concentration of about 0.25,
0.30, 0.50, 0.51, 0.75, 0.99, 1.00, 1.50 or about 1.54 weight %
based on the total weight of the slurry.
[0036] In one embodiment, the aluminum phosphate slurry composition
provided herein comprises from about 50 weight % to about 60 weight
% aluminum phosphate and less than about 2 or less than about 1
weight % tetrapotassium pyrophosphate based on the total weight of
the slurry. In one embodiment, the aluminum phosphate slurry
composition provided herein comprises from about 50 weight % to
about 60 weight % aluminum phosphate and about 0.50 weight % to
about 1 weight % tetrapotassium pyrophosphate based on the total
weight of the slurry. In another embodiment, the aluminum phosphate
slurry composition provided herein comprises about 51, 53 or 58
weight % aluminum phosphate and about 1 weight % tetrapotassium
pyrophosphate based on the total weight of the slurry. In a further
embodiment, the aluminum phosphate slurry composition provided
herein comprises about 51 weight % aluminum phosphate and about 1
weight % tetrapotassium pyrophosphate based on the total weight of
the slurry.
[0037] In one embodiment, the dispersant in the aluminum phosphate
slurry composition provided herein comprises sodium potassium
triphosphate in a concentration of about 0.10 to about 3.50 weight
% based on the total weight of the slurry. In another embodiment,
the dispersant in the aluminum phosphate slurry composition
provided herein comprises sodium potassium triphosphate in a
concentration of about 0.10 to about 3.10 weight % based on the
total weight of the slurry. In yet another embodiment, the
dispersant in the aluminum phosphate slurry composition provided
herein comprises sodium potassium triphosphate in a concentration
of about 0.25 to about 1.55 weight % based on the total weight of
the slurry. In a further embodiment, the dispersant in the aluminum
phosphate slurry composition provided herein comprises sodium
potassium triphosphate in a concentration oh about 0.10, 0.24,
0.25, 0.30, 0.50, 0.52, 0.75, 0.99, 1.00 or 1.50 weight % based on
the total weight of the slurry.
[0038] In one embodiment, the aluminum phosphate slurry composition
provided herein comprises from about 50 weight % to about 60 weight
% aluminum phosphate and less than about 2 or less than about 1
weight % sodium potassium triphosphate based on the total weight of
the slurry. In one embodiment, the aluminum phosphate slurry
composition provided herein comprises from about 50 weight % to
about 60 weight % aluminum phosphate and about 1 weight % sodium
potassium triphosphate based on the total weight of the slurry. In
another embodiment, the aluminum phosphate slurry composition
provided herein comprises about 51, 53 or 58 weight % aluminum
phosphate and about 1 weight % sodium potassium triphosphate based
on the total weight of the slurry. In a further embodiment, the
aluminum phosphate slurry composition provided herein comprises
about 51 weight % aluminum phosphate and about 1 weight % sodium
potassium triphosphate based on the total weight of the slurry.
[0039] In one embodiment, the dispersant in the aluminum phosphate
slurry composition provided herein comprises sodium
hexametaphosphate in a concentration of about 0.10 to about 3.50
weight % based on the total weight of the slurry. In another
embodiment, the dispersant in the aluminum phosphate slurry
composition provided herein comprises sodium hexametaphosphate in a
concentration of about 0.10 to about 3.10 weight % based on the
total weight of the slurry. In one embodiment, the dispersant in
the aluminum phosphate slurry composition provided herein comprises
sodium hexametaphosphate in a concentration of about 0.25 to about
1.55 weight % based on the total weight of the slurry. In another
embodiment, the dispersant in the aluminum phosphate slurry
composition provided herein comprises sodium hexametaphosphate in a
concentration of about 0.10, 0.25, 0.29, 0.50, 0.75, 0.99, 1.00 or
1.50 weight % based on the total weight of the slurry.
[0040] In one embodiment, the aluminum phosphate slurry composition
provided herein comprises from about 50 weight % to about 60 weight
% aluminum phosphate and less than about 2 or less than about 1
weight % sodium hexametaphosphate based on the total weight of the
slurry. In one embodiment, the aluminum phosphate slurry
composition provided herein comprises from about 50 weight % to
about 60 weight % aluminum phosphate and about 0.25 weight % to
about 1 weight % sodium hexametaphosphate based on the total
weighty of the slurry. In another embodiment, the aluminum
phosphate slurry composition provided herein comprises about 51, 53
or 58 weight % aluminum phosphate and about 0.25 or about 1 weight
% sodium hexametaphosphate based on the total weight of the slurry.
In another embodiment, the aluminum phosphate slurry composition
provided herein comprises about 51 weight % aluminum phosphate and
about 0.25 or about 1 weight % sodium hexametaphosphate based on
the total weight of the slurry.
[0041] Further exemplary dispersants are listed in Tables
1a-1e.
TABLE-US-00001 TABLE 1A PHOSPHATE DISPERSANTS Group Name General
Formula Examples Monophosphate or PO.sub.4.sup.3- aH.sub.2O
Na.sub.3PO.sub.4, trisodium phosphate Orthophosphate a = 0 to 12
Ca(H.sub.2PO.sub.4).sub.2, calcium dihodrogen phosphate
Polyphosphates P.sub.nO.sub.3n+1.sup.(n + 2)-
NaH.sub.3P.sub.2O.sub.7; Sodium trihydrogen (chain form)
pyrophosphate (monosodium pyrophosphate
Na.sub.2H.sub.2P.sub.2O.sub.7 . Disodium dihydrogen pyrophosphate
(sodium acid pyrophosphate) Na.sub.3HP.sub.2O.sub.7, Trisodium
hydrogen pyrophosphate (trisodium pyrophosphate)
Na.sub.4P.sub.2O.sub.7, Tetrasodium pyrophosphate (TSPP)
KH.sub.3P.sub.2O.sub.7, Potassium trihydrogen pyrophosphate
K.sub.2H.sub.2P.sub.2O.sub.7, Dipotassium dihydrogen pyrophosphate
(potassium acid pyrophosphate) K.sub.3HP.sub.2O.sub.7, Tripotassium
hydrogen pyrophosphate K.sub.4P.sub.2O.sub.7, Tetrapotassium
pyrophosphate CaH.sub.2P.sub.2O.sub.7, Calcium dihydrogcn
pyrophosphate Na.sub.5P.sub.3O.sub.10, Sodium tripolyphosphate
(STP) Na.sub.xK.sub.yP.sub.3O.sub.10, (x=1-4, y=5-x) Sodium
potassium tripolyphosphate K.sub.5P.sub.3O.sub.10, Potassium
tripolyphosphates (KTP) Ca.sub.5P.sub.3O.sub.10, Calcium
triphosphate (LiPO.sub.3).sub.n Lithium polyphosphate
(NaPO.sub.3).sub.x, Sodium polyphosphate
[Na.sub.2H(PO.sub.3).sub.3].sub.n Disodium hydrogen polyphosphates
(KPO.sub.3).sub.n, Potassium polyphosphates (NH.sub.4PO).sub.n or
(NH.sub.4).sub.n+2P.sub.nO.sub.3n+] Ammonium polyphosphate
[Ca(PO.sub.3).sub.2].sub.n, Calcium polyphosphate
[CuK.sub.2(PO.sub.3).sub.2].sub.n, Copper potassium polyphosphate
[CuNH.sub.4(PO.sub.3).sub.2].sub.n, Copper ammonium polyphosphate
[Al(PO.sub.3).sub.3].sub.n, Aluminum polyphosphate
(RbPO.sub.3).sub.n Rubidium polyphosphate (CsPO.sub.3).sub.n Cesium
polyphosphate Cross linked or P.sub.nO.sub.3-1.sup.(n-2)-
CaP.sub.4O.sub.10 ultraphosphates Ca.sub.2P.sub.6O.sub.17
Metaphosphates (PO.sub.3.sup.-).sub.n Na.sub.3(PO.sub.3).sub.3,
sodium trimetaphosphate Na.sub.6(PO.sub.3).sub.6, sodium
hexametaphosphate Where n = 2, 3, 4 . . .
TABLE-US-00002 TABLE 1b ORGANIC PHOSPHATES Group Name General
Formula Examples Glycerol C.sub.3H.sub.7O.sub.6P.sup.2- M.sup.+
Glycerol 1-phosphates Phosphates M.sup.+ = metal cation Glycerol
2-phosphate Phosphate Phosphate Ester of TriStyryPhenol POE 16,
free acid esters Phosphate Ester of TriStyryPhenol POE 16, K Salt
Phosphate Ester of C8-10, Acid Phosphate Ester of 2-Ethyl Hexanol,
Acid Phosphate Ester of 2-Ethyl Hexanol POE 2, K Salt Phosphate
Ester of NonylPhenol POE 4, Acid ##STR00001## Phosphate Ester of
NonylPhenol POE 6, Acid Phosphate Ester of NonylPhenol POE 6, K
Salt Phosphate Ester of NonylPhenol POE 9, Acid Phosphate Ester of
NonylPhenol POE 10, Acid Phosphate Ester of DiNonylPhenol POE 8,
Acid Phosphate Ester of IsoDecyl Alcohol POE 6, Acid Phosphate
Ester of IsoDecyl Alcohol POE 6, K Salt Phosphate Ester of TriDecyl
Alcohol POE 6, Acid Phosphate Ester of C12, K Salt Phosphate Ester
of C12-15, Acid Phosphate Ester of C12-15 POE 5, Acid Phosphate
Ester of C12-15 POE 5, K Salt Phosphate Ester of C12-18 POE 3, Acid
Phosphate Ester of C12-14 POE 6, Acid Phosphate Ester of C12-18 POE
9, Na Salt Phosphate Ester of C16-18 POE 5, Acid Phosphate Ester
[Alcohol Carbon Chain]-[Moles of R = Alkyl chain, EO][Salt]
unsubstituted of substituted with one or more groups selected from
OH, halo and amino. X = metal cation or H
TABLE-US-00003 TABLE 1C SILICATE DISPERSANTS Silicate Type Unit
structures Examples Orthosilicate SiO.sub.4.sup.4-
Na.sub.4SiO.sub.4 Meiasilicate SiO.sub.3.sup.2- Na.sub.2SiO.sub.3
Disilicate Si.sub.2O.sub.5.sup.2- Na.sub.2Si.sub.2O.sub.5
Tetrasilicate Si.sub.4O.sub.9.sup.2- Na.sub.2Si.sub.4O.sub.9
TABLE-US-00004 TABLE 1D BORATE DISPERSANTS Group Name Formula
Examples Borates M.sub.2O.nB.sub.2O.sub.3.aH.sub.2O
Na.sub.2O.2B.sub.2O.sub.3.10H.sub.2O, M = metal cation, disodium
tetraborate decahydrate n = 1-5 and a = 1-10
Na.sub.2O.4B.sub.2O.sub.3.4H.sub.2O, disodium octaborate
tetrahydrate Na.sub.2O.5B.sub.2O.sub.3.10H.sub.2O, sodium
pentaborate pentahydrate Li.sub.2O.2B.sub.2O.sub.3.4H.sub.2O
Li.sub.2O.B.sub.2O.sub.3.4H.sub.2O
Na.sub.2O.5B.sub.2O.sub.3.10H.sub.2O
Na.sub.2O.2B.sub.2O.sub.3.10H.sub.2O
Na.sub.2O.B.sub.2O..sub.4H.sub.2O
K.sub.2O.5B.sub.2O.sub.3.4H.sub.2O
K.sub.2O.2B.sub.2O.sub.3.4H.sub.2O
K.sub.2O.B.sub.2O.sub.32.5H.sub.2O
Rb.sub.2O.5B.sub.2O.sub.3.8H.sub.2O
Cs.sub.2O.5B.sub.2O.sub.3.7H.sub.2O
(NH.sub.4).sub.2O.2B.sub.2O.sub.3.4H.sub.2O
(NH.sub.4).sub.2O.5B.sub.2O.sub.3.8H.sub.2O
TABLE-US-00005 TABLE 1E ALUMINATE DISPERSANTS Group Name Examples
Aluminates NaAlO.sub.2, Na.sub.2O.Al.sub.2O.sub.3 or
Na.sub.2Al.sub.2O.sub.4 BaO.6Al.sub.2O.sub.3 BaO.Al.sub.2O.sub.3
3BaO.Al.sub.2O.sub.3
Processes for Preparing Amorphous Aluminum Phosphate Particles
[0042] The amorphous aluminum phosphate particles used in the
slurry can be prepared by any methods known to one of skill in the
art. Exemplary methods are described herein and in U.S. patent
publication nos. 2006/0211798 and 2006/0045831 and U.S. application
Ser. No. 11/891,510. The disclosures of such patent applications is
incorporated by reference in their entirety herein.
[0043] In one embodiment, the process of manufacturing hollow
particles of aluminum phosphate, aluminum polyphosphate, aluminum
metaphosphate, aluminum orthophosphate (or combinations thereof)
used in the slurry formulations comprises the following general
steps. One of skill in the art will recognize that certain steps
may be altered or omitted altogether. The steps include:
preparation of the main reagents used in the process, such as
diluted solution of phosphoric acid, diluted solution of the
aluminum sulfate, and diluted solution of sodium hydroxide sodium
carbonate, potassium hydroxide or ammonium hydroxide; simultaneous
and controlled addition of the reagents in a reactor equipped with
a sloshing system to keep the homogeneity of the mixture during the
process; control, during the addition of the reagents in the
reactor, of the temperature and pH (acidity) of the mixture and,
mainly, the reaction time; filtration of the suspension, with
approximately 8.0% of solids and separation of the liquid and solid
phases, in an appropriate equipment; washing out the impurities
present in the filter cake with slightly alkaline aqueous solution;
dispersion of the washed cake, containing approximately 20-30% of
the solids, in an adequate disperser; drying of the dispersed pulp
in a turbo-dryer; micronization of the dried product to an average
granulometry of 5.0 to 10 microns; and polymerization of the dried
product by thermal treatment of the aluminum phosphate in a
calcinator.
[0044] There are several ways to prepare the main reagents in this
process. One source of phosphorus for the manufacturing of aluminum
phosphate is the fertilizer grade phosphoric acid, from any origin,
as it is clarified and discolored. For example, a commercial
phosphoric acid containing approximately 54% of P.sub.2O.sub.5 may
be chemically treated and/or diluted with treated water resulting
in a concentration of 20% P.sub.2O.sub.5. Also, as an alternative
to this process (instead of fertilizer grade phosphoric acid or
purified phosphoric acid), salts of phosphorus as orthophosphates,
polyphosphates or metaphosphates can be used.
[0045] Another reagent for the process is the commercial aluminum
sulfate. The aluminum sulfate may be obtained from the reaction
between the alumina (hydrate aluminum oxide) with concentrated
sulfuric acid (98% H.sub.2SO.sub.4), and then clarified and stored
at a 28% concentration of Al.sub.2O.sub.3. For the reaction to have
favorable kinetics, the aluminum sulfate is diluted with water
treated at 5.0% of Al.sub.2O.sub.3. As an alternative for this
process, the source of aluminum can be any other salt of aluminum,
as well as aluminum hydroxide or aluminum in metallic form.
[0046] The neutralization of the reaction is carried out with a
sodium hydroxide solution, which may be commercially purchased in
different concentrations. A concentration of 50% of NaOH may be
purchased and diluted. For example, in the first phase of the
reaction, when the initial reagents are being mixed, the sodium
hydroxide may be used in the concentration of 20% of NaOH. In the
second phase of the reaction, due to the need of a fine-tuning of
the product acidity, a sodium hydroxide solution with 5.0% of NaOH
may be used. As an alternative neutralizer, ammonium hydroxide or
sodium carbonate (soda ash) may be used.
[0047] In one aspect, a chemical reaction results in the formation
of hydroxoaluminum orthophosphates, either pure or mixed (e.g.,
Al(OH).sub.2(H.sub.2PO.sub.4) or Al(OH)(HPO.sub.4). The reaction,
as described, is carried out through the mixture of the three
reagents, i.e., phosphoric acid solution, aluminum sulfate
solution, and sodium hydroxide solution. The reagents are dosed in
a reactor, typically containing a sloshing system, during a
30-minute period. During the addition of the reagents in the
reactor, the pH of the mixture is controlled within a 1.4 to 4.5
range and a reaction temperature, between 35.degree. C. and
40.degree. C. The reaction is completed after 15 minutes of the
reagent mixture. In this period, the pH of the mixture may be
adjusted at 3.0 to 5.0, with the addition of more diluted sodium
hydroxide. In this embodiment, the temperature is preferably below
approximately 40.degree. C. At the end of the reaction, the
suspension formed should contain a mole ratio between the
phosphorus:aluminum elements in a 1.1 to 1.5 range.
[0048] After the formation of the aluminum orthophosphate, the
suspension containing around 6.0% to 10.0 of solids, with a maximum
approximate temperature of 45.degree. C., and density in a 1.15 to
1.25 g/cm3 range, is pumped to a conventional filter press. In the
filer press, the liquid phase (sometimes refereed to as the
"liquor") is separated from the solid phase (often referred to as
the "cake"). The wet cake, containing approximately 18% to 45% of
solids, and still possible contaminated with the sodium sulfate
solution, is kept in the filter for washing cycle. The filtered
concentrate, which is basically concentrated solution of sodium
sulfate, is extracted from the filter and stored for future
usage.
[0049] In one embodiment, the washing of the wet cake is performed
in the filter itself and in three process steps. In the first
washing ("displacement washing") the largest part of the filtered
substance that is contaminating the cake is removed. The washing
step is performed using treated water over the cake at a flow rate
of 6.0 m.sup.3 of water/ton of dried cake. A second washing step,
also with treated water and with a flow of 8.0 m.sup.3 of water/ton
of dried cake, may be carried out to further reduce, if not
eliminate, the contaminants. And, finally, a third washing step
using a slightly alkaline solution may be carried out. Such third
washing step may be performed for the neutralization of the cake
and to keep its pH in the 7.0 range. Finally, the cake may be blown
with compressed air during a certain period of time. In certain
embodiments, the wet product comprises between 35% and 45% of
solids.
[0050] In one aspect, the cake dispersion may be processed in such
a way that the filter cake, wet and washed, and containing
approximately 35% of solids, is extracted from the press filter by
a conveyor belt and transferred to a reactor/disperser. The
dispersion of the cake is aided by the addition of a dilute
solution of tetra-sodium pyrophosphate.
[0051] After the dispersion step, the product is then dried, when
the aluminum phosphate "mud," with a percentage of solids within
the 18% to 50% range, is pumped to the drying unit. In one
embodiment, the water removal from the material can be carried out
with drying equipment, such as a "turbo dryer" type through an
injection of a hot air stream, at a temperature of 135.degree. C.
to 140.degree. C., through the sample. The final humidity of the
product should preferentially be kept in the 10% to 20% of water
range.
[0052] In the next step, the orthophosphate of the dry aluminum, as
Al(H.sub.2PO.sub.4).sub.3, is condensed by a thermal treatment to
form a hollow aluminum polyphosphate, that is
(Al.sub.(n+2)/3(P.sub.nO.sub.(3n+1)), where "n" can be any integer
greater than 1, preferably, n is greater than or equal to 4. In
certain embodiments, n is greater than or equal to 10. In other
embodiments, n is greater than or equal to 20, less than 100 or
less than 50. This process step can be carried out by heating the
phosphate aluminum, in a spray-drier, in a temperature range of
500.degree. C. to 600.degree. C. After the polymerization, the
product may be cooled quickly and sent to the micronization unit.
At this point, product micronization step may be carried out.
Finally, the resulting product that leaves the drier is transferred
to the grinding and finishing unit, ground in a micronizer/sorter,
and its granulometry kept in the 99.5% range below 400 mesh.
[0053] In another aspect, the steps in the process for preparation
of aluminum phosphate used in the slurry compositions include:
preparation of the main reagents used in the process, such as
solution of phosphoric acid, solid hydrated aluminum hydroxide and
sodium aluminate solution; addition of the reagents in a reactor
equipped with a sloshing system to keep the homogeneity of the
mixture during the process; control, during the addition of the
reagents in the reactor, of the temperature and pH of the mixture
and the reaction time; filtration of the suspension; washing out of
the impurities present in the filter cake; dispersion of the washed
cake in an adequate disperser; drying of the dispersed pulp in a
turbo-dryer or spray drier; micronization of the dried product by
thermal treatment of the aluminum phosphate in a calcinator. In
certain embodiments, the process comprises a step of premixing
phosphoric acid and aluminum sulfate solutions before addition to
the reactor. In certain embodiments, the aluminum phosphate or
polyphosphate in pigments can be prepared and used as a slurry pulp
(dispersion of high content of solids, which flows under the action
of gravity or low pressure pumps) with 20-60% or more of
non-volatiles by weight; as dried and micronized aluminum phosphate
with about 10-30%, in certain embodiments, 10, 12, 15, 17, 20, 25
or 30% of humidity; and also in the polymeric form as calcinated
micronized aluminum polyphosphate.
[0054] In one embodiment, the amorphous aluminum phosphate is
prepared by a reaction between phosphoric acid and aluminum
hydroxide. The process may further comprise a step of centralizing.
The neutralizing step can be carried out by sodium aluminate.
[0055] In certain embodiments, the process for making an amorphous
aluminum phosphate or polyphosphate comprises reacting phosphoric
acid, aluminum hydroxide and sodium aluminate.
[0056] In one embodiment, the process for making an amorphous
sodium phosphate or polyphosphate comprises reacting aluminum
phosphate and sodium aluminate.
[0057] In one embodiment, the reaction comprises two steps. In the
first step, phosphoric acid reacts with aluminum hydroxide to
produce aluminum phosphate at an acidic pH. In one embodiment, the
aluminum phosphate is produced as a water soluble aluminum
phosphate. In certain embodiments, the pH of water soluble aluminum
phosphate is less than about 3.5. In certain embodiments, the pH is
about 3, 2.5, 2, 1.5 or 1. In certain embodiments, the aluminum
phosphate is produced as a fine solid-liquid dispersion at a higher
pH. In one embodiment, the pH is about 3, 4, 5 or 6.
[0058] In a second step, the acidic aqueous aluminum phosphate
solution or dispersion from the first chemical step is reacted with
a sodium aluminate. In certain embodiments, the sodium aluminate is
used as an aqueous solution at a pH greater than about 10. In one
embodiment, the pH of the aqueous sodium aluminate solution is
about 11, 12 or 13. In one embodiment, the pH of the aqueous sodium
aluminate solution is greater than about 12. The aluminum sodium
phosphate is generated as a solid precipitate. In one embodiment,
the solid aluminum-sodium phosphate has a molar ratio P/Al=0.85 and
a molar ratio Na/Al=0.50. In one embodiment, the solid
aluminum-sodium phosphate has a molar ratio P/Al=1.0 and a molar
ratio Na/Al=0.76. In certain embodiments, the molecules with other
formulation ratios can be obtained by the same procedure.
[0059] In one embodiment, the solid hydrated aluminum hydroxide is
added to the phosphoric acid in the first chemical step. In another
embodiment, the solid hydrated aluminum hydroxide is added to the
purified liquid sodium aluminate solution to form a colloidal
solution. In another embodiment, the solid hydrated aluminum
hydroxide is added directly as solid or solid-liquid suspension in
water in the second reaction step. In certain embodiments, the
reaction is carried out in a single step.
[0060] In certain embodiments, the reactor to perform the second
step of the reaction, i.e., reaction of an acidic aqueous aluminum
phosphate solution or dispersion from the first chemical step with
sodium aluminate, has a very high mixing and shear stress
performance to mix the reactants and to generate a solid
precipitate with the desired particle size distribution. In certain
embodiments, the reactor dispersion properties could be adjusted
for the spray drying process requirements. In one embodiment, the
reactor is a CSTR (continuous stirred-tank reactor).
[0061] The sodium aluminate solution for use in the process
provided herein can be obtained by methods known to those of skill
in the art. In one embodiment, the sodium aluminate solution is a
standard chemical product resulting from the first step in the
Bayer process in the alumina (Al.sub.2O.sub.3) extraction from
Bauxite ore, often called "purified sodium pregnant solution". This
liquid aqueous sodium aluminate solution is saturated at ambient
temperature and stabilized with sodium hydroxide, NaOH. The typical
compositions are: sodium aluminate, 58 to 65 % mass (25 to 28% mass
of Al.sub.2O.sub.3) and sodium hydroxide, 3.5 to 5.5 % mass (2.5 to
4 % mass of free Na.sub.2O). In certain embodiments, it has a molar
ratio Na/Al from about 1.10 to 2.20 and low impurities (depending
on the Bauxite origin: Fe=40 ppm, Heavy metals=20 ppm, and small
amount of anions, Cl.sup.- and SO.sub.4.sup.2-). In certain
embodiments, the sodium aluminate water solution has a molar ratio
Na/Al of about 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45,
1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2.0,
2.05, 2.10, 2.15 or 2.2. The solution color, in certain
embodiments, is amber. In certain embodiments, the viscosity of the
solution is approximately 100 cP. In certain aspects, the sodium
aluminate solution is purified by polishing filtration. In certain
embodiments, the sodium aluminate solution is regenerated from
solid aluminum hydroxide and sodium hydroxide.
[0062] The solid hydrated aluminum hydroxide is obtained by methods
known to one of skill in the art. In one embodiment, aluminum
hydroxide is an industrial chemical produced by the Bayer process.
The solid hydrated aluminum hydroxide can be obtained from the
"purified sodium aluminate pregnant solution" by precipitation
which is accomplished via cooling the solution. In one embodiment,
the sodium aluminate thus produced has a low level of impurities
and a variable amount of humidity (cations about 70 ppm, Chlorates
about 0.85% mass and Sulfates about 0.60% mass (these impurities
are determined by the purification level of the "Purified Sodium
Aluminate pregnant solution) and the total water, hydration and
humidity, about 22.0 to 23.5 % mass. In one aspect, both raw
materials are standard primary industrial products, just first and
second step from the Bauxite processing, (commodities) produced in
huge amounts by the Bauxite processors.
[0063] In one embodiment, the chemical reaction results in the
formation of aluminum sodium phosphate
(Al(OH).sub.0.7Na.sub.0.7(PO.sub.4).1.7H.sub.2O). After the
formation of aluminum sodium phosphate, the suspension containing
around 6.0% to 10.0% of solids, with a maximum approximate
temperature of 45.degree. C., and density in a 1.15 to 1.25
g/cm.sup.3 range, is pumped to a conventional filter press. In one
embodiment, the suspension contains about 15-30%, 10-30% or 15-25%
solids. In one embodiment, the suspension contains about 15-25%
solids. In one embodiment, the suspension density is in a 1 to 1.3
or 1.10 to 1.20 g/cm.sup.3 range. In the filter press, the liquid
phase (sometimes referred to as the "liquor") is separated from the
solid phase (sometimes referred to as the "cake"). The wet cake,
containing approximately 35% to 45% of solids, in certain
embodiment, about 35, 40 or 45% solids, is kept in the fiber for
washing cycle.
[0064] In one embodiment, the washing of the wet cake is performed
in the filter itself and in two to three process steps. In the
first washing ("displacement washing") the largest part of the
filtered substance that is contaminating the cake is removed. The
washing step is performed using treated water ever the cake at a
flow rate of 6.0 m.sup.3 of water/ton of dried cake. A second
washing step, also with treated water and with a flow of 8.0
m.sup.3 of water/ton of dried cake, may be carried out to reduce
the contaminants. And, finally, a third washing step may be carried
out with water to further reduce the contaminants. Finally, the
cake may be blown with compressed air during a certain period of
time. The wet product should present between 35% and 45% of
solids.
[0065] Next, in this particular embodiment, the cake dispersion may
be processed in such a way that the filter cake, wet and washed, is
extracted from the press filter by a conveyor belt and transferred
to a reactor/disperser.
[0066] In certain embodiments, the dispersion of the cake is aided
by the addition of a dispersing agent, such as a solution of sodium
polyphosphate.
[0067] In one embodiment, after the dispersion step, the produce is
dried, when the aluminum phosphate "slurry," with a percentage of
solids within the 30% to 50% range, is pumped to the drying unit.
In another embodiment, the water removal from the material can be
carried out with drying equipment, such as "turbo dryer" through an
injection of hot air stream, or a "spray dryer" at a temperature of
80.degree. C. to 350.degree. C., through the sample. The final
humidity of the product can be kept in the 10% to 20% of water
range.
[0068] In certain embodiments, the next step of the process
includes product calcination. In this step, the orthophosphate ions
of the dry aluminum phosphate undergo condensation to polyphosphate
ions (diphosphate, triphosphate, tetraphosphate, n-phosphate where
"n" can be any integer greater than 1, in certain embodiments, n is
greater than or equal to 4). In one embodiment, n is greater than
or equal to 10. In another embodiment, n is greater than or equal
to 20. In one embodiment, n is less than 100. In another
embodiment, n is less than 50. This process step is carried out by
heating the aluminum phosphate, in a calcinator, in a temperature
range of 500.degree. C. to 600.degree. C. After the polymerization,
the product may be cooled quickly and sent to the micronization
unit. At this point, product micronization step may be carried
out.
[0069] Finally, the resulting product that leaves the calcinator is
transferred to the grinding and finishing unit, ground in a
micronizer/sorter, and its granulometry kept in the 99.5% range
below 400 mesh.
[0070] In certain embodiments, micronization of the dried product
is carried out to an average granulometry of 5.0 to 10 microns or
between about 0.1 to about 5 microns.
Processes for Preparation of Aluminum Phosphate Slurry
Compositions
[0071] The aluminum phosphate slurry compositions comprising
amorphous aluminum phosphate and one or more dispersants can be
prepared any methods known to one of skill in the art. In one
embodiment, the slurry composition comprises about 40 to about 70
weight % aluminum phosphate by the total weight of the composition
and is prepared by mixing i) a stock slurry comprising about 30
weight % aluminum phosphate; ii) aluminum phosphate powder, for
example, obtained by the process described above; and ii) a
dispersant.
[0072] In one embodiment, the stock slurry comprises about 30-40
weight % amorphous aluminum phosphate. The stock slurry can be
prepared, for example, as described in the processes above.
[0073] In certain embodiments, the slurry compositions comprising
aluminum phosphate and one or more dispersants is prepared by
mixing i) an amorphous aluminum phosphate powder, ii) a dispersant
or a mixture of dispersants and iii) a solvent. In certain
embodiments, the solvent is water. The amorphous aluminum phosphate
powder can be prepared, for example, by the processes described
above. The slurry mixture is stirred for 10-25 minutes using a
suitable disperser, for example, Cowles disperser, with a suitable
stirring velocity, for example stirring velocity of 730.+-.30 rpm
to obtain a homogeneous dispersion. Exemplary slurry compositions
are described in Example 3.
Applications of Aluminum Phosphate Slurry Compositions
[0074] The aluminum phosphate particles in the slurry compositions
described herein demonstrate improved properties in certain
aspects. For example, the aluminum phosphate particles present
voids, when the particles are dried, for example, at room
temperature, or up to 130.degree. C. In one embodiment, the
particles present voids when dried between 40.degree. C. and
130.degree. C., In another embodiment, the particles present voids
when dried between 60.degree. C. and 130.degree. C. In certain
embodiments, the particles present voids when dried between
80.degree. C. and 120.degree. C. In addition, the aluminum
phosphate particles have a core-and-shell structure. In other
words, these particles have shells chemically different from their
cores. This property is evidenced by several different
observations. First, the energy-filtered, inelastic electron images
of the particles in the plasmon region (10-40 eV), as measured by a
transmission electron microscope, show bright lines surrounding
most particles. Nanoindentation measurements performed in the
digital pulsed three microscope (DPFM) show that particle surfaces
are stiffer than the particle interior.
[0075] When a dispersion of such particles dries under air at room
temperature or up to 120.degree. C., nano-sized particles are
formed that have a core-and-shell structure. The nano-sized
panicles show a partial coalescence into micron-sized aggregates
with irregular shapes. Such particles may be observed by analytical
electron microscopy. Moreover, these particles contain many voids
dispersed as closed pores in their interior. The cores of the
particles are more plastic than the respective shells of the
particles. This phenomenon is evidenced by growth of the voids upon
heating, while the perimeter of the shells remains essentially
unaltered.
[0076] The aluminum phosphate compositions described herein can be
used as replacement for titanium dioxide (i.e., TiO.sub.2).
Titanium dioxide is the current standard white pigment used by
almost all manufacturers involved in latex paint formulations. The
optical measurements taken from films drawn using a paint
containing a usual load of titanium dioxide and a paint wherein
fifty percent of the titanium dioxide load was replaced by
amorphous aluminum phosphate demonstrate that aluminum phosphate
may replace titanium dioxide producing films while preserving the
optical properties of the film.
[0077] The aluminum phosphate used in the compositions described
herein has relatively small particle size. Such smaller particles
sizes allow the particles to distribute extensively in the film and
to associate intimately with the resin, with inorganic fillers and
with themselves, thereby creating clusters that are sites for
extensive void formation when the paint dries. In some embodiments,
the particles of aluminum phosphate or polyphosphate are
substantially free of open pores while containing a number of
closed pores. As a result, in such embodiments, the macropore
volume is substantially less than 0.1 cc/gram.
[0078] Opacification of water-based paint films using aluminum
phosphate in some embodiments involves unique features. The wet
coating film is a viscous dispersion of polymer, aluminum
phosphate, titanium dioxide and filler particles. When this
dispersion is cast as a film and dried, it behaves differently from
a standard paint (below the critical pigment volume concentration,
CPVC). In a standard paint, the low glass transition temperature
(Tg) resin is plastic at room temperature and coalesced, so that
the resin film fills pores and voids. A paint formulated with
aluminum phosphate, however, can exhibit a different behavior. The
closed pores form, as described herein, and contribute to the film
hiding power.
[0079] Various paints can be formulated using the aluminum
phosphate compositions described in various embodiments herein,
alone or in combination with another pigment, such as titanium
dioxide. A paint comprises one or more pigments and one or more
polymers as the binder (sometimes referred to as "binding
polymer"), and optionally various additives. There are water-borne
paints and non-water-borne paints. Generally, a water-borne paint
composition is composed of four basic components: binder, aqueous
carrier, pigment(s) and additive(s). The binder is a nonvolatile
resinous material that is dispersed in the aqueous carrier to form
a latex. When the aqueous carrier evaporates, the binder forms a
paint film that binds together the pigment particles and other
non-volatile components of the water-borne paint composition.
Water-borne paint compositions can be formulated according to the
methods and components disclosed in U.S. Pat. No. 6,646,058, with
or without modifications. The disclosure of such patent is
incorporated by reference in its entirety herein. The aluminum
phosphate compositions described in various embodiments herein can
be used to formulate water-borne paints, alone or in combination
with titanium dioxide.
[0080] A common paint is a latex paint which comprises a binding
polymer, a hiding pigment, and optionally a thickener and other
additives. Again, the aluminum phosphate compositions described in
various embodiments herein can be used to formulate latex paints as
a pigment, alone or in combination with titanium dioxide. Other
components for making a latex paint are disclosed in U.S. Pat. No.
6,881,782 and No. 4,782,109, which are incorporated by reference
herein in their entirety. By way of illustration, suitable
components and methods for making latex paints are briefly
explained below.
[0081] In some embodiments, suitable binding polymers include
emulsion copolymerized ethylenically unsaturated monomers including
0.8% to 6% of fatty acid acrylate or methacrylate such as lauryl
methacrylate and/or stearyl methacrylate. Based on the weight of
copolymerized ethylenic monomers, the polymeric binder comprises
0.8% to 6% fatty acid methacrylate or acrylate where preferred
compositions contain 1% to 5% of copolymerized fatty acid acrylate
or methacrylate having an aliphatic fatty acid chain comprising
between 10 and 22 carbon atoms. In one embodiment, lauryl
methacrylate and/or stearyl methacrylate are used. In one
embodiment, lauryl methacrylate is the monomer of choice. Other
useful fatty acid methacrylates include myristyl methacrylate,
decyl methacrylate, palmitic methacrylate, oleic methacrylate,
hexadecyl methacrylate, cetyl methacrylate and eicosyl
methacrylate, and similar straight chain aliphatic methacrylate.
Fatty acid methacrylates or acrylates typically comprise commercial
fatty oils coreacted with methacrylic acid or acrylic acid to
provide primarily the dominant fatty acid moiety methacrylate with
minor amounts of other fatty acid acrylates or methacrylates.
[0082] Polymerizable ethylenically unsaturated monomers contain
carbon-to-carbon unsaturation and include vinyl monomers, acrylic
monomers, allylic monomers, acrylamide monomers, and mono- and
dicarboxylic unsaturated acids. Vinyl esters include vinyl acetate,
vinyl propionate, vinyl butyrates, vinyl benzoates, vinyl isopropyl
acetates and similar vinyl esters; vinyl halides include vinyl
chloride, vinyl fluoride, and vinylidene chloride; vinyl aromatic
hydrocarbons include styrene, methyl styrenes and similar lower
alkyl styrenes, chlorostyrene, vinyl toluene, vinyl naphthalene,
and divinyl benzene; vinyl aliphatic hydrocarbon monomers include
alpha olefins such as ethylene, propylene, isobutylene, and
cyclohexene as well as conjugated diens such as 1,3-butadiene,
methyl-2-butadiene, 1,3-piperylene, 2,3 dimethyl butadiene,
isoprene, cyclohexane, cyclopentadiene, and dicyclopentadiene.
Vinyl alkyl ethers include methyl vinyl ether, isopropyl vinyl
ether, n-butyl vinyl ether, and isobutyl vinyl ether. Acrylic
monomers include monomers such as lower alkyl esters of acrylic or
methacrylic acid having an alkyl ester portion containing between 1
to 12 carbon atoms as well as aromatic derivatives of acrylic and
methacrylic acid. Useful acrylic monomers include, for example,
acrylic and methacrylic acid, methyl acrylate and methacrylate,
ethyl acrylate and methacrylate, butyl acrylate and methacrylate,
propyl acrylate and methacrylate, 2-ethyl hexyl acrylate and
methacrylate, cyclohexyl acrylate and methacrylate, decyl acrylate
and methacrylate, isodecylacrylate and methacrylate, benzyl
acrylate and methacrylate, and various reaction products such as
butyl phenyl, and cresyl glycidyl ethers reacted with acrylic and
methacrylic acids, hydroxyl alkyl acrylates and methacrylates such
as hydroxyethyl and hydroxypropyl acrylates and methacrylates, as
well as amino acrylates and methacrylates. Acrylic monomers can
include very minor amounts of acrylic acids including acrylic and
methacrylic acid, ethacrylic acid, alpha-chloroacrylic acid,
alpha-cyanoacrylic acid, crotonic acid, beta-acryloxy propionic
acid, and beta-styryl acrylic acid.
[0083] In other embodiments, polymers useful as component (a), the
"binding polymer", of the latex paints are copolymerization
products of a mixture of co-monomers which comprise monomers
selected from styrene, methyl styrene, vinyl, or combinations
thereof. In one embodiment, co-monomers comprise at least 40 mole
percent of monomers selected from styrene, methyl styrene, or
combinations thereof and at least 10 mole percent of one or more
monomers selected from acrylates, methacrylates, and acrylonitrile.
In another embodiment, the acrylates and methacrylates contain from
4 to 16 carbon atoms such as, for example, 2-ethylhexyl acrylate
and methyl methacrylates. The monomers may be used in a proportion
such that the final polymer has a glass-transition temperature (Tg)
greater than 21.degree. C. and less than 95.degree. C. In one
embodiment, the polymers have a weight-average molecular weight of
at least 100,000.
[0084] In one embodiment, the binding polymer comprises
interpolymerized units derived from 2-ethylhexyl acrylate. In
another embodiment, the binding polymer comprises polymerized units
comprising from 50 to 70 mole percent of units derived from
styrene, methyl styrene, or combinations thereof; from 10 to 30
mole percent of units derived from 2-ethylhexyl acrylate; and from
10 to 30 mole percent of units derived from methyl acrylate,
acrylonitrile, or combinations thereof.
[0085] Illustrative examples of suitable binding polymers include a
copolymer whose interpolymerized units are derived from about 49
mole percent styrene, 11 mole percent alpha-methylstyrene, 22 mole
percent 2-ethylhexyl acrylate, and 18 mole percent methyl
methacrylates with a Tg of approximately 45.degree. C. (available
as Neocryl XA-6037 polymer emulsion from ICI Americas, Inc.
Bridgewater, N.J.); a copolymer whose interpolymerized units are
derived from about 51 mole percent styrene, 12 mole percent
.alpha.-methylstyrene, 17 mole percent 2-ethylhexyl acrylate, and
19 mole percent methyl methacrylates with a Tg of approximately
44.degree. C. (available as Joncryl 537 polymer emulsion from S.C.
Johnson & Sons, Racine, Wis.); and a terpolymer whose
interpolymerized units are derived from about 54 mole percent
styrene, 23 mole percent 2-ethylhexyl acrylate, and 23 mole percent
acrylonitrile with a Tg of approximately 44.degree. C. (available
as Carboset.TM. XPD-1468 polymer emulsion from B.F. Goodrich Co.).
In one embodiment, the binding polymer is Joncryl.TM. 537.
[0086] As described above, the aluminum phosphate compositions
described herein can be used to formulate latex paints as a
pigment, alone or in combination with another pigment.
[0087] Suitable additional hiding pigments include white opacifying
hiding pigments and colored organic and inorganic pigments.
Representative examples of suitable white opacifying hiding
pigments include rutile and anatase titanium dioxides, lithopone,
zinc sulfide, lead titanate, antimony oxide, zirconium oxide,
barium sulfate, white lead, zinc oxide, leaded zinc oxide, and the
like, and mixtures thereof. In one embodiment, white organic hiding
pigment is rutile titanium dioxide. In another embodiment, the
white organic hiding pigment is rutile titanium dioxide having an
average particle size between about 0.2 to 0.4 microns. Examples of
colored organic pigments are phthalo blue and hansa yellow.
Examples of colored inorganic pigments are red iron oxide, brown
oxide, ochres, and umbers.
[0088] Most know latex paints contain thickeners to modify the
rheological properties of the paint to ensure good spreading,
handling, and application characteristics. Suitable thickeners
include a non-cellulosic thickener, in one embodiment, as
associative thickener; in another embodiment, a urethane
associative thickener.
[0089] Associative thickeners such as, for example, hydrophobically
modified alkali swellable acrylic copolymers and hydrophobically
modified urethane copolymers generally impart more Newtonian
rheology to emulsion paints compared to conventional thickeners
such as, for example, cellulosic thickeners. Representative
examples of suitable associative thickeners include polyacrylic
acids (available, for example, from Rohm & Haas Co.,
Philadelphia, Pa., as Acrysol RM-825 and QR-708 Rheology Modifier)
and activated attapulgite (available from Engelhard, Iselin, N.J.
as Attagel 40).
[0090] Latex-paint films are formed by coalescence of the binding
polymer to form a binding matrix at the ambient paint application
temperature to form a hard, tack-free film. Coalescing solvents aid
the coalescence of the film-forming binder by lowering the
film-forming temperature. The latex paints preferably contain a
coalescing solvent. Representative examples of suitable coalescing
solvents include 2-phenoxyethanol, diethylene glycol butyl ether,
dibutyl phthalate, diethylene glycol,
2,2,4-trimethyl-1,1,3-pentanediol monoisobutyrate, and combinations
thereof. In one embodiment, the coalescing solvent is diethylene
glycol butyl ether (butyl carbitol) (available from Sigma-Aldrich,
Milwaukee, Wis.) or 2,2,4-trimethyl-1,1,3-pentanediol
monoisobutyrate (available from Eastman Chemical Co., Kingsport,
Tenn., as Texanol), or combinations thereof.
[0091] Coalescing solvent is preferably utilized at a level between
about 12 to 60 grams or about 40 grams of coalescing solvent per
liter of latex paint or at about 20 to 30 weight percent based on
the weight of the polymer solids in the paint.
[0092] The paints formulated in accordance with various embodiments
provided herein can further comprise conventional materials used in
paints such as, for example, plasticizer, anti-foam agent, pigment
extender, pH adjuster, tinting color, and biocide. Such typical
ingredients are listed, for example, in TECHNOLOGY OF PAINTS,
VARNISHES AND LACQUERS, edited by C. R. Martens, R.E. Kreiger
Publishing Co., p. 515 (1974).
[0093] Paints are commonly formulated with "functional extenders"
to increase coverage, reduce cost, achieve durability, alter
appearance, control rheology, and influence other desirable
properties. Examples of functional extenders include, for example,
barium sulfate, calcium carbonate, clay, gypsum, silica, and
talc.
[0094] The most common functional extenders for interior flat
paints are clays. Clays have a number of properties that make them
desirable. Inexpensive calcined clays, for example, are useful in
controlling low-shear viscosity and have a large internal surface
area, which contributes to "dry hide". But, this surface area is
also available to trap stains.
[0095] Because of their tendency to absorb stains, it is preferable
that calcined clays are used in the paints only in the small
amounts required for rheology control, for example, typically as
less than about half of the total extender pigment, or are not used
at all. The exemplary extenders for use in the paints described
herein are calcium carbonates; that in certain embodiments, are
ultra-fine ground calcium carbonates such as, for example,
Opacimite (available from ECC International, Sylacauga, Ala.),
Supermite (available from Imerys, Roswell, Ga.), or others having
particle size of approximately 1.0 to 1.2 microns. Ultra-fine
calcium carbonate help to space titanium dioxide optimally for hide
(see, for example, K. A. Haagenson, "The effect of extender
particle size on the hiding properties of an interior latex flat
paint," American Paint & Coatings Journal, Apr. 4, 1988, pp.
89-94).
[0096] The latex paints formulated in accordance with various
embodiments described herein can be prepared utilizing conventional
techniques. For example, some of the paint ingredients are
generally blended together under high shear to form a mixture
commonly referred to as "the grind"0 by paint formulators. The
consistency of this mixture is comparable to that of mud, which is
desirable in order to efficiently disperse the ingredients with a
high shear stirrer. During the preparation of the grind, high shear
energy is used to break apart agglomerated pigment particles.
[0097] The ingredients not included in the grind are commonly
referred to as "the letdown." The letdown is usually much less
viscous than the grind, and is usually used to dilute the grind to
obtain a final paint with the proper consistency. The final mixing
of the grind with the letdown is typically carried out with low
shear mixing.
[0098] Most polymer latexes are not shear stable, and therefore are
not used as a component of the grind. Incorporation of shear
unstable latexes in the grind can result in coagulation of the
latex, yielding a lumpy paint with no, or little, film-forming
capability. Consequently, paints are generally prepared by adding
the latex polymer in the letdown. However, some paints formulated
in accordance with various embodiments described herein contain
latex polymers that are generally shear stable. Therefore, the
latex paints can be prepared by incorporating some or all of the
latex polymer into the grind. In one embodiment, at least some of
the latex polymer is put in the grind.
[0099] The examples of compositions according to various
embodiments described above are presented below. Again, one of
skill in the art will recognize variants that may be utilized in
the compositions described herein. The following examples are
presented to exemplify embodiments of the claimed subject matter.
All numerical values are approximate. When numerical ranges are
given, it should be understood that embodiments outside the stated
ranges may still fall within the scope of the invention. Specific
details described in each example should not be construed as
necessary features of the invetion.
EXAMPLES
Example 1
Preparation of Aluminum Phosphate Powder
[0100] 791 g of phosphoric acid (81.9% wt H.sub.3PO.sub.4 or 59.3%
wt P.sub.2O.sub.5) were reacted with 189 g of hydrated aluminum
hydroxide (85.3% wt Al(OH).sub.3 or 58.1% wt Al.sub.2O.sub.3) in
210 g of water at 80.degree. C. for 1 h (final molar ratio
P/Al=2.99) to obtain an acidic aluminum phosphate solution. In the
second step, 1155 g of commercial purified sodium aluminate
solution (9.7% wt Al and 11.2% wt Na or 18.3% wt Al.sub.2O.sub.3
and 15.7% wt Na.sub.2O, final Na/Al=1.36) were added simultaneously
with acidic aluminum phosphate solution to a stirred vessel loaded
with 1500 g of water at room temperature.
[0101] The final reaction pH was 7.1 and temperature during the
reaction was kept at 45.degree. C. The resulting dispersion was
centrifuged (30 mm, 2500 rpm--relative centrifugal force: 1822 g)
to remove the reaction liquor, forming a cake that was washed with
water once (1000 g of washing water) to give a white wet cake (3300
g) with 27.0% wt non-volatiles content (902 g on dry basis
following ASTM D280) and pH 7.3. The slurry was spray-dried
yielding 1090 g of aluminum phosphate powder (ea 83% wt
non-volatiles content).
Example 2
Preparation of Aluminum Phosphate Powder
[0102] In this example, 535.0 kg of aluminum phosphate was
prepared. The wet product was dried in a "turbo-dryer" and
presented characteristics of hollow particles with 15% humidity and
P:Al (phosphorus:aluminum) ratio of 1:1.50.
[0103] 940.0 kg of fertilizer phosphoric acid containing 55.0% of
P.sub.2O.sub.5 was used. In the initial preparation phase, the acid
discoloration was carried out, which lasted approximately thirty
minutes, at a temperature of 85.degree. C. For this phase, a
solution with 8.70 kg of hydrogen peroxide containing around 50% of
H.sub.2O.sub.2 was added to the acid. Then, the acid was diluted
with 975.0 kg of process water, cooled to a temperature of
40.degree. C. and then stored at the concentration of 27.0% of
P.sub.2O.sub.5.
[0104] The aluminum source employed in this application was a
commercial aluminum sulfate solution containing 28% of
Al.sub.2O.sub.3. The solution was filtered and diluted with process
water. Specifically, 884.30 kg of aluminum sulfate solution and
1,776.31 kg of process water was combined to create a solution of
approximately 9.30% Al.sub.2O.sub.3.
[0105] This particular experiment used a diluted solution of
commercial sodium hydroxide containing 20.0% of NaOH as a
neutralizing reagent. Specifically, 974.0 kg of sodium hydroxide
solution with 50% of NaOH and 1,461.0 kg of process water were
mixed. The final mixture was cooled to 40.degree. C.
[0106] The three reagents were mixed simultaneously, for
approximately 30 minutes, in a reactor with 7,500 liters. During
the addition of the reagents in the reactor, the mixture
temperature was kept in the 40.degree. C. to 45.degree. C. range,
the pH was controlled to stay in a range of 4.0 to 4.5. At the end
of the addition of reagents, the mixture was kept sloshing for
approximately 15 minutes. The pH at this point was controlled at
approximately 5.0 with the addition of a sodium hydroxide solution
containing 5.0% of NaOH. The resulting suspension was approximately
7,000 kg with a density of 1.15 g/cm.sup.3, presented 6.5% of
solids, which represent around 455.0 kg Of precipitate.
[0107] Then, the suspension was filtered in a press-filter
resulting in 1,300 kg of wet cake and 5,700 kg of filtrate. The
filtrate consisted primarily of a sodium sulfate solution
(Na.sub.2SO.sub.4). The cake consisted of approximately 35% solids.
The cake was washed, directly in the press filter, with 3,860
liters of process water, at room temperature, being kept at a
washing ratio of approximately 8.5 cm.sup.3 of the washing solution
per ton of dry cake. The filtrate generated in the washing of the
cake was stored for optional future use or for effluent treatment.
The cake extracted from the filter, around 1,300 kg, was then
transferred to a disperser (of approximately 1,000 liters) through
a conveyor belt. The dispersion, containing approximately 35% of
solids, had a density of 1.33 g/cm.sup.3 and viscosity of 80-200
cPS and could be used as a slurry for making paint.
[0108] The dispersed aluminum phosphate suspension, with
approximately 35% of solids, was then pumped to a turbo-drier. The
product was heated, through a hot air stream, at a temperature of
135.degree. C. Approximately 535.0 kg of aluminum orthophosphate
with 15% of humidity was produced. The final product was micronized
and its granulometry was kept below the 400 mesh. The final
analysis of the dry product presented the following results: the
phosphorus content in the produce was approximately 20.2%; the
aluminum content was approximately 13.9%; the sodium content was
approximately 6.9% and the pH of the aqueous dispersion was
approximately 7.0; the water content was approximately 15%; the
skeletal density of 2.20 g/cm.sup.3, and average diameter of powder
particles was from 5 to 10 .mu.m.
Example 3
Preparation of Aluminum Phosphate Slurry Containing 51 wt. %
Aluminum Phosphate and Viscosity measurements
[0109] A stock slurry containing 37.2 wt % non-volatiles content
and an aluminum phosphate stock powder containing 85.5 wt %
non-volatiles were used with the following dispersants in various
amounts to prepare aluminum phosphate slurry samples containing 51
wt. % and >51 wt. % aluminum phosphate: [0110] i. Tetrasodium
pyrophosphate (TSPP), Na.sub.4P.sub.2O.sub.7, [0111] ii. Sodium
hexametaphosphate, Na(PO.sub.3).sub.x, Nuclear. [0112] iii.
Pentasodium triphosphate, Na.sub.5P.sub.3O.sub.10, Merck. [0113]
iv. Trisodium phosphate dodecahydrate, Na.sub.3PO.sub.4, Merck.
[0114] v. Tetrapotassium pyrophosphate (TKPP),
K.sub.4P.sub.2O.sub.7, [0115] vi. Sodium potassium triphosphate,
K.sub.4.65Na.sub.0.35P.sub.3O.sub.10, prepared from (iii) using ion
exchange resin (Dowex 50WX4-400).
[0116] Solubility of the phosphate dispersants in water (wt %) at
20-25.degree. C. is provided in Table 2 below:
TABLE-US-00006 TABLE 2 Phosphate dispersants solubility in water
Dispersant Water solubility (wt %) at 20-25.degree. C. Tetrasodium
prophosphate 5-6.sup.(a) Sodium hexametaphosphate 20-30.sup.(b)
Pentasodium triphosphate 13-15.sup.(a) Trisodium phosphate
dodecahydrate 25.sup.(b) Tetrapotassium pyrophosphate 60.sup.(b)
.sup.(a)Ullmann's Encyclopedia of Industrial Chemistry
.sup.(b)Determined using standard methods
[0117] Slurry Preparation
[0118] A) 51 wt % aluminum phosphate slurry without dispersant
[0119] 52.0 g of aluminum phosphate stock powder were slowly added
to 140.0 g of aluminum phosphate stock slurry. Mixing was done
using a Cowles disperser with stirring velocity at 730.+-.30 rpm;
powder addition took about 25 minutes and final mixture was further
stirred for about 15 minutes.
[0120] B) 51 wt % aluminum phosphate slurries with dispersant
[0121] The dispersant stock solutions were prepared by dissolving
each phosphate salt in distilled water to yield the following
concentrations:
[0122] 5.0 wt % tetrasodium pyrophosphate,
[0123] 20 wt % sodium hexametaphosphate,
[0124] 11 wt % pentasodium triphosphate,
[0125] 7.7 wt % trisodium phosphate dodecahydrate, 50 wt %
tetrapotassium pyrophosphate, and
[0126] 8 wt % sodium potassium triphosphate.
[0127] Phosphate dispersant solutions were added to stock aluminum
phosphate slurry to achieve the desired dispersant concentration.
Then, aluminum phosphate powder was added to aluminum phosphate
dispersant slurry. Amounts of all components used to prepare 51%
aluminum phosphate slurry are listed in the Table 3 and 4.
TABLE-US-00007 TABLE 3 Aluminum phosphate slurry compositions with
various dispersants Aluminum Dispersant concentration Aluminum
Dispersant phosphate in 51% aluminum phosphate solution powder
Dispersant phosphate slurry (wt %) slurry stock amount (g) amount
(g) Total weight (g) Na.sub.3PO.sub.4 0.24 150.00 7.50 82.50 240.00
0.50 200.00 23.00 129.00 352.00 Na.sub.4P.sub.2O.sub.7 0.10 100.00
3.00 49.00 152.00 0.27 140.00 12.00 70.00 222.00 0.50 140.00 26.00
94.00 260.00 0.97 140.00 70.00 150.00 360.00 1.49 70.00 100.00
165.00 335.00 K.sub.4P.sub.2O.sub.7 0.25 100.00 0.72 46.00 146.72
0.51 100.00 1.50 47.00 148.50 0.99 100.00 3.00 49.00 152.00 1.54
100.00 4.80 51.50 156.30 Na.sub.5P.sub.3O.sub.10 0.10 100.00 1.50
47.00 148.50 0.25 150.00 5.50 80.00 235.50 0.53 150.00 12.50 95.00
257.50 0.99 150.00 26.00 110.00 286.00 1.52 100.00 31.50 94.50
226.00 3.06 20.00 34.00 57.00 111.00
K.sub.4.65Na.sub.6.35P.sub.3O.sub.10 0.10 100.00 47.00 1.20 148.20
0.24 100.00 49.00 3.10 152.10 0.52 100.00 55.00 7.00 162.00 0.99
100.00 66.00 15.00 181.00 1.51 100.00 81.00 26.00 207.00 3.02 50.00
87.00 46.00 183.00 Na(PO.sub.3).sub.x 0.10 135.00 1.00 63.00 199.00
0.29 140.00 2.60 34.00 176.60 0.49 140.00 5.00 60.00 205.00 1.00
140.00 11.00 70.00 221.00 1.51 140.00 18.00 80.00 238.00 3.04
100.00 35.00 95.00 230.00
TABLE-US-00008 TABLE 4 Aluminum phosphate slurry compositions with
dispersant mixtures: Dispersant concentration in Aluminum 51%
Aluminum Aluminum Dispersant phosphate phosphate slurry phosphate
solution powder Total Dispersant (wt %) slurry amount (g) amount
weight mixture Na.sub.5P.sub.3O.sub.10 Na(PO).sub.3).sub.4 stock
Na.sub.5P.sub.3O.sub.10 Na(PO.sub.3).sub.4 (g) (g) A 0.98 0.49
100.00 20.00 5.00 80.00 205.00 B 0.50 0.99 100.00 9.40 9.40 71.00
189.80
TABLE-US-00009 TABLE 5 Slurry compositions with >51 wt %
aluminum phosphate Dispersant Aluminum Aluminum Aluminum phosphate
concentration in phosphate Dispersant phosphate concentration in
the aluminum slurry stock solution powder Total final slurry (wt %)
phosphate slurry (wt %) amount (g) amount (g) amount (g) weight (g)
54.17 0.99 100.00 21.00 90.50 211.50 53.85 1.51 100.00 39.00 119.00
258.00 55.71 0.98 100.00 19.70 99.00 218.70 55.45 1.51 100.00 37.00
129.00 266.00
Viscosity Measurements
[0128] Viscosity of 51% aluminum phosphate slurry compositions was
measured using a Rheoterm 115 Rheometer (Contraves). 51% aluminum
phosphate slurry samples were stirred for 15 min, using a Cowles
disperser, with stirring velocity set at 730.+-.30 rpm. Then, the
sample was added to a coaxial cylindrical geometry vessel and the
spindle was placed within the vessel. The sample was left standing
for 1 hour at 25.degree. C. Then, the viscosity readings were made
at 100, 300 and 500 s.sup.-1 shear rates and provided in Tables 6
and 7.
TABLE-US-00010 TABLE 6 Viscosity and sedimentation behavior of 51%
aluminum phosphate slurry compositions prepared with carious
dispersants 51% slurry Dispersant Viscosity (cPs) Dispersant
Concentration (wt %) Sedimentation (%).sup.1,2 100 s.sup.-1 300
s.sup.-1 500 s.sup.-1 None 0 0 2064 .+-. 177 1334 .+-. 103 1084
.+-. 167 Na.sub.3PO.sub.4 0.25 0 1780 1130 982 0.5 0 2064 1273 1024
Na.sub.4P.sub.2O.sub.7 0.10 0 1805 1068 871 0.25 0 1406 .+-. 411
877 .+-. 225 705 .+-. 206 0.5 0 1406 .+-. 193 813 .+-. 102 609 .+-.
101 1.0 0 1813 .+-. 378 1050 .+-. 93 698 .+-. 27 1.5 0 1890 .+-.
186 1017 .+-. 44 697 .+-. 6 K.sub.4P.sub.2O.sub.7 0.25 0 21399 1343
1097 0.5 0 1868 1183 939 1.0 0 1312 670 553 1.5 0 2774 1396 1051
Na.sub.5P.sub.3O.sub.10 0.10 0 1963 1174 966 0.25 0 1361 .+-. 166
843 .+-. 89 549 .+-. 89 0.5 0 927 .+-. 224 662 .+-. 81 506 .+-. 50
1.0 60 760 462 393 1.5 55 576 583 425 3.0 96 585 465 376
K.sub.4.65Na.sub.6.35P.sub.3O.sub.10 0.10 0 2164 1219 954 0.25 0
1629 956 797 0.5 0 1855 961 662 1.0 0 927 704 561 1.5 24 801 633
509 3.0 74 727 575 460 Na(PO.sub.3).sub.x 0.10 0 2047 1155 893 0.25
0 1152 .+-. 44 802 .+-. 58 680 .+-. 47 0.5 0 965 .+-. 135 604 .+-.
81 475 .+-. 54 1.0 0 1044 .+-. 295 660 .+-. 196 500 .+-. 152 1.5 0
973 .+-. 76 591 .+-. 67 456 .+-. 40 3.0 0 2,523 1,236 893
Na.sub.3P.sub.3O.sub.10 + A.sup.3 1.5 (total) 0 1,161 852 681
Na(PO.sub.3).sub.x B.sup.4 1.5 (total) 0 1,872 1,359 1,023
.sup.1After 3 hours standing at room temperature (23 .+-. 2.degree.
C.). .sup.2% of height occupied by sediment.
.sup.3Na.sub.5P.sub.3O.sub.10 (0.98 wt %) and Na(PO.sub.3)x (0.49
wt %). .sup.4Na.sub.5P.sub.3O.sub.10 (0.50 wt %) and Na(PO.sub.3)x
(0.99 wt %).
TABLE-US-00011 Aluminum Dispersant phosphate concentration in
concentration aluminum in the final phospate slurry Sedimentation
Viscosity (cPs) slurry (wt %) (wt %) % 100 s.sup.-1 300 s.sup.-1
500 s.sup.-1 54.17 0.99 0 2874 1682 1218 53.85 1.51 0 1308 914 757
55.71 0.98 0 3693 1926 1437 55.45 1.51 0 5623 2405 1687
[0129] As seen from the data in Tables 6-7 and FIG. 1, sodium
hexametaphosphate and pentasodium triphosphate dispersants produced
lowwer viscosities for 51 wt % aluminum phosphate slurry. Most
samples upon standing underwent gel formation, but the gels formed
were much weaker than the gel formed in 51 wt % Aluminum phosphate
slurry without dispersant. The gels formed did not flow under
gravity but they were easily thinned when sheared. Sodium potassium
triphosphate, K.sub.4.65Na.sub.0.35P.sub.3O.sub.10, also produced
lower viscosity for 51% aluminum phosphate slurry with two
benefits: (i) no sedimentation at 1 wt % concentration, and (ii)
the formed gel was much weaker than the slurry with pentasodium
triphosphate. In the case of 51 wt % aluminum phosphate slurry with
Na.sub.5P.sub.3O.sub.10 and K.sub.4.65Na.sub.0.35P.sub.3O.sub.10,
at higher dispersant concentration, the viscosity reduction was
excessive, allowing the formation of packed sediment.
[0130] The increase of solid content in slurry composition with
Na.sub.5P.sub.3O.sub.10 seemed to avoid sedimentation but the
viscosity increased considerably and the slurry turned to a gel
that was not easily thinned. In certain embodiments, the highest
useful concentration of aluminum phosphate in the slurry is about
54 weight % with about 1.5 weight % Na.sub.5P.sub.3O.sub.10 (second
line, Table 7).
[0131] Most of the 51 wt % slurries analyzed had their viscosities
increased after accelerated ageing tests (7 days at 54.degree. C.);
however, the viscosity was still the highest for the slurry without
dispersant. Slurry compositions with Na(PO.sub.3)x at 1.0 and 1.5
wt % did not show significant increase in viscosity after aging
test. Slurries after 3 weeks at room temperature (see, FIG. 2) did
not show any correlation with the accelerated tests in the oven (7
days at 54.degree. C.).
[0132] The 51 wt % slurry composition without dispersant decreases
its viscosity after preparation and the slurries with lower
dispersant concentration (0.25 and 0.50%) tend to increase their
viscosities with time except Na.sub.5P.sub.3O.sub.10 that keeps its
initial value. On the other hand, in the 51 wt % slurries with
tetrasodium pyrophosphate and Na(PO.sub.3)x at higher concentration
(1.0 and 1.5%), the viscosities tend to decrease from initial
value.
[0133] In certain embodiments, the viscosity range suitable to
prepare 51% aluminum phosphate slurry is from 900 to 1150 cPs. At
this range, a weak gel is formed in the slurries upon standing and
sedimentation is not observed.
[0134] In a typical paint dry film, the pigment and filler
particles are dispersed in the resin film. The hiding power is
largely dependent on the particle refractive indices and sizes. As
mentioned titanium dioxide is currently the standard white pigment
because of its large refractive index and of the absence of light
absorption in the visible region. A dry film of a paint formulated
with the aluminum phosphate compositions in some embodiments
provided herein has several differences from the typical paint dry
film. First, the film with the aluminum phosphate is not just a
resin film. It is rather formed by enmeshed resin and aluminum
phosphate. It is thus a nanocomposite film that combines two
interpenetrating phases with different properties to achieve
synergistic benefits, concerning film mechanical properties and
resistance to water and to other aggressive agents. Second, good
film hiding power is obtained at lower titanium dioxide contents,
because the film contains a large amount of closed pores that
scatter light. Moreover, if a titanium dioxide particle is adjacent
to one of these voids, it will scatter much more than if it is
fully surrounded by resin, due to the larger refractive index
gradient. This creates a synergism between the novel aluminum
phosphate and titanium dioxide, as far as the hiding power is
concerned.
[0135] In tests comparing a standard paint dry film to a film with
aluminum phosphate, a standard market formulation of a semi-matt
acrylic paint is chosen and titanium dioxide is progressively
replaced by the aluminum phosphate product. Water content and other
paint components are adjusted as required. Several of the
modifications in the formula in this embodiment are related to a
decreased use of thickener/rheology modifier, dispersant, acrylic
resin and coalescing agent.
[0136] As demonstrated above, embodiments described herein provide
a compositions comprising aluminum phosphate slurry comprising
about 40-70% non-volatiles and one or more dispersants.
[0137] While the subject/matter has been described with respect to
a limited number of embodiments, the specific features of one
embodiment should not be attributed to other embodiments of the
invention. No single embodiment is representative of all aspects of
the invention. In some embodiments, the compositions or methods may
include numerous compounds or steps not mentioned herein. In other
embodiments, the compositions or methods do not include, or are
substantially free of, any compounds or steps not enumerated
herein. Variations and modifications from the described embodiments
exist. The method of making the resins or pigments is described as
comprising a number of acts or steps. These steps or acts may be
practiced in any sequence or order unless otherwise indicated.
Finally, any number disclosed herein should be construed to mean
approximate, regardless of whether the word "about" or
"approximately" is used in describing the number. The appended
claims intend to cover all those modifications and variations as
falling within the scope of the invention.
* * * * *