Note: Descriptions are shown in the official language in which they were submitted.
11;~501V
UI~BLE PIG~ENTED SII.ICATE COMPOSITIONS
Background oE the Invention
During the past several years, environmental pollution concerns
have led those active in the coatings, castings and moldings arts to
develop various curabie compositions in which organic solvents derived
from petroleum have been eliminated or at least substantially minimized.
Thus, compositions such as water-based compositions and high solids
compositions have been extenslvely investigated. Even more recently
the high cost and scarcity of petroLeum by-products has engendered interest
in the development of curable compositions which are composed entirely of~
or at least substantially of, inorganic components.
Inorganic coating compositions based on alkali metal silicates
are well known in the art. Such compositions can be applied from an
aqueous medium alone or in combination with various known insolubilizing
agents. The insolubilizing agents aid in the fast formation of a water-
resistant silicate coating. The coatings are inorganic in nature with the
consequent advantages discussed above and possess a desired set of properties.
Unfortunately, pigmented coatings based on the alkali metal
silicate can have a less than desired appearance due to an inade-
quate pigment dispersion in the coating composition. This inadequate
pigment dispersion is most noticeable in lapped areas, where Eresh addi-
tional coating composition is applied over a first coat of the same composi-
tion.
The present invention relates to pigmented inorganic coatin~
compositions based on water-soluble or water-dispersible silicates
which are capable of providing coatings having good color uniforrnity.
1 1;~5 0 1 0
As ~Ised hcrein, al~ percents and ratios are by weLght unless
otherwise indlcated.
Summary of the Invention
Curable aqueous compositions consist essentially of inorganic
constituents. More particularly, the curable compositions consist essen-
tially of aqueous solutions or dispersions of silicate glass, pigments
and a base having a basicity greater than tha~ of the silicate glass. In
one embodiment of the invention, the base is initially ground with the
pigment and the resultant grind then combined with the silicate glass.
This technique of mixing minimizes shock.
The invention thus provides a curable coating composition having
improved pigment dispersion, consisting essentially of
(a) an aqueous phase of
(i) from about 2 percent to about 50 percent of a water-
soluble alkali metal silicate glass having a SiO2:M20
mole ratio of about 2:1 to about 4:1 wherein M represents
the alkali metal;
(ii) from about 0.01 percent to about 5 percent of a water-
soluble base having a basicity greater than that of the
silicate glass; and
(iii) from about 50 percent to about 98 percent of water;
(b) pigment, wherein the pigment represents from about 5 percent
to about 90 percent by volume of the solids in the composi-
tion; and
(c) a water-soluble latent insolubillzing agent for the silicate.
Description of the Invention
This invention is concerned with the discovery that the presence of
certain bases either preadsorbed on a plgment's surface or separately added
to compositions containing the pigment and an alkali metal silicate glass,
improve the appearance of cured films formed from the compositions. In a
preferred embodiment the compositions also contain metal ion containing
latent insolubiliæing agents. The compositions consist essentially of an
2 -
~.
. . .
1,1;~5~0
aqueous phase ancl plgment. ~ach o~ the components of the compositions and
thecomposit~ons~ method of production are describcd in the paragraphs
which follow.
- 2~ -
5~0
Watcr-~oluble or wa~er-disper;ible silicate. which are ernployed
in the co~npositiolls are the alkali metal siLicates, e.g., sodiu;n silicate,
potassium silicate, lithium silicate, and mixtures thereof. Preferred
water-soluble silicate glasses are sodium and potassium silicate with
SiO~:?t2o mole ratios o~ about 2:l to about 4:l, with U representing
al'~ali rnetal. The level of silicate glass in the aqueous phase of the
compositions ranges from about 2 percent to about 50 percent, preEerably
about lO percent to about 40 percent. (While silicates comrnercially
available are usually aqueous solutions of silicate, the afore~entioned
percents are given on a silicate solids basis.)
The compositions of the invention also consist essentially of at
least one pigment. Preferred pigments are characterized by their ability
to adsorb a base from an aqueous solution thereof. Many pigrnents displaying
this characteristic are useful in the compositions of this invention.
While the term "adsorb" is employed, it is employed in the sense of
removal from solution and is not intended to imply a physical rather than
chemical interaction between pigment surface and the base. In fact, the
precise mode of interaction is not known. It is believed that any pigment
having metal ions on its surface capable of interacting with the base can
be enhanced by this invention. This includes most commonly employed
pigments.
While the invention enhances the coLor uniformity properties
of any pigment, particularly useful pigments include titanium dioxide,
barium metaborate, alumina, zinc oxide, clay and mica. The invention
~ is particularly useful where the compositions coneain one or rnore organic
or inorganic coloring pigrnents which impart a color ~other than white),
particularly a pastel, bright or intense color. Useful coloring pigments
11;~50~
include iron o~ide red, bariu-n yello-J, ~inc yellow, zinc green, cadmium
yelLow, chrome ~-~ide green, coba~t blue, greell or violet, various rnixed
metal oxides and organic pigments of the azo series. Base-treated pigrnents
are also useful and can, in part or in full, provide the source of the base
discussed below. The pigments are employed as dispersed pulverulent
solids. Mi~tures of pigmellts can and generally are employed. The pigments
are present in an amount of about 5 percent to about 90 perc~nt and prefera-
bly about 30 percent to about 70 percent based on the total volune of
solids in the composition, i.e., % PVC.
Another essential con:ponent of the compositions of the inven~ion --
is a base having a basicity greater than that of the silicate glass. Such
bases include the alkali metai and quaternary ammonium hydroxides, e.g.,
potassium hydroxide, sodium hydroxide and tetraethyl ammonium hydroxide;
alkali metal silicates having a SiO2:~l20 mole ratio of from about 1:2 to
about 2:1 where ~ is alkali metal, e.g., sodium orthosilicate; organo
silanolates, e.g., tripotassium -aminopropylsilantriolate, tripotassium N-
( -aminoethyl)- -aminopropylsilantriolate, tripotassium -aminopropyl-
silantriolate, dipotassium -aminopropylmethylsilantriolate, potassium
-aminobutyldimethylsilantriolate, tripotassium methyl-silantriolate,
dipotassium dimethylsilandiolate and potassium trimethylsilanolate; and-
mi~tures thereof.
The base employed has a basicity grea~er than that oE the silicate
glass as measured by their respective p~l's at the same normality. This
results in the compositions having a better dispersion as evidenced by
, better color unifornity, hiding power, lo~er viscosity and consistency, and
being substantially lump-free. The level of base in the aqueous phase of
the compositions ranges from abou, 0.01 perc~nt to about 5 percent. A
-- 4 --
~ 50~0
preferrcd range of base for dilute applicacions such 3S Eound in eLectrode
deposition coating is from about 0.01 percent to about 4 percent. A
preferred can~e oE base in the co~positions for other coating applications
ran,es from about 0.1 percent to about 4 percent. An increase in pH in the
vicinity of the surface of the pigment is theorized as bPing responsible
for the compositions' better pigment dispersions. This increase in pH is
bel;eved to be due to the base having a greater affinity Eor the pigmenc's
~urface than the silicate glass.
Bases above described can be added directly as a component of the
curable compositions during or after their formulation. Alternatively, the
base can be admixed with at least a portion of the pigment to be employed
in the composition. ~his l~ter method of incorporating the base into che
CompoQitions is preferred; i~ has been found the resultant compositions
are even ~ore substantially lump-free due to less shock when the pigmen~/
base and silicate are combined to form the coating compositions.
The compositions are ~ater based. While the amount of water can
~ary widely tepending ~n intended use> generally the aqueous phase Oe the
composieions consists essentially of between about 50 percent and about 98
percent water, preEerably between about 60 percent and about 90 percent.
A preferred e~bodi~ent of the invention are the above described
compositions additionally consisting essentially of a water-soluble latent
insolubilizing agent. Such agents improve the water-resistance of the
silicate coatings and are Eor this reason desired. Satisfactory insolu-
bilizing agents are described in tl~e following paragraphs.
25 I Metallate insolubilizing agents are describ~d in U.S. Pa~ent No.
4,140,535, issued February 20, 1979 and No. 4,169,735, issued on October
2~ 1~79.
1~35010
The described systems comprise a blend ~f silicates and water-soluble
metallate latent lnsolubilizlng agents where the water-soluble latent in-
solubilizing agent is selected from alkali metal or quaternary ammonium
zincates and borates. Still another water-soluble latent insolubllizing
agent is an alkali metal or quaternary ammonium aluminate. Illustrative
of such metallate latent insolubilizing agents which can be employed are
lithium zincate, potassium zincate, and sodium zincate; lithium borate,
potassium metaborate, and sodium tetraborate; and lithium aluminate,
potassium aluminate, and sodium aluminate. The term "borate" as used in
connection with the alkali metal borates is intended to include ortho-
borates, pyroborates, metaborates and more complex borate ions. The
alkali metal aluminates, especially sodium aluminate, are preferred in-
solubilizing agents.
U.S. Patent 3,715,224, to Campbell discloses solutions and/or
colloidal suspensions of water-soluble silicates containing monovalent and
divalent metal ion complexes. The disclosed metal ion complexes are useful
latent insolubillzing agents here also.
Yet other insolubilizing agents are described in U.S. Patent
4,137,087, issued January 30, 1979. Water-soluble latent insolubilizing
agents are formed from metal ions selected from the group consisting of
Al , Fe , Cr and Sn and ligands (i.e., complexing agents)
selected from the group consisting of ethylenediaminetetraacetate, di-
ethylenetriaminepentaacetate, N-~hydroxyethyl)ethylenediaminetetraacetate,
nitrilotriacetate ~nd 1,3-propanediaminetetraacetate. It should be noted
that other similar or analogous type ligands where they exist may be
employed and these are
-- 6 --
SO10
considered to be within the scope of the invention. Illustrative examples
of such latent insolubilizing agents are compounds such as sodium ethylene-
diaminetetraacetatoaluminate (III), sodium ethyLenediaminetetraacetato-
ferrate (III), sodium etllylenediaminetetraacetatochromate (IIIj, and
sodium ethylenediaminetetraacetatostannate (II). --
~le amount of latent insolubilizing agent included in the
compositions can vary considerably depending UpOll desired properties.
Ilowever, in general, ehe amount of latent insolubilizing agent employed is
an amount sufficient to enhance wet abrasion and water resistance of the
cured composition but which is insufficient to cause an irreversible gel ~-
when the uncured composition is stored for 24 hours at 70 C. In most
instances, amounts of metallate latent insolubilizing agent ranging
from about O.l percent to about 6 percent, preferably from about 0.25
percent to about 2.5 percent by weight, based upon the combined weight of
the silicate glass and metallate latent insolubilizing agent are employed.
Insolubilizing agents based on the metal ions and ligands are present at a
level of from about 0.2 percent to about 12 percent, preferably from about
l percent to about 5 percent, again based on the combined weight of silicate
glass and insolubilizing agent.
The reaction between the silicate glass and latent insolubilizing
agent is not known with certitude; however, it is theorized the metalLic
ion associates with the ligand and the resulting conple.~ maintains the
composition in a reasonably stable configuration. Ilowever, upon drying
(e.g., air drying or baking) the equilibria shift and the metal ion or the
~ meeallic ion is released to crosslink the silicate glass and form an
insoluble silicate composition having e~cellent properties. E~amples of
the properties obtained are stain resistance, flame and heat resistance and
water resistance.
li;~SO10
The p;gmented curab~e compositiolls o~ the invention can contain
ccrtain otller additives such as, ~or example, dyes, ~illers, antioxidants,
flow control agents, and surfactants.
In addition it is often advantageous to include in the composi-
tions a thickener. Of particular value are water-soluble thickeners which
are solub;lized through carboxyl groups. Illustrative of such materials
are sodium polyacrylate, potassium polymethacrylate, sodium salts of
styrene maleic anllydride copolymers, sodium carboxymethyl cellulose,
and potassium polyacrylate copolymers. Also suitable are inorganic thick-
eners such as clays and the like. ~
As mentioned above, the curable compositions of the invention
can be employed in various applications. The compositions are particularly
useful in coatings over a variety of substrates such as wood, metals,
glass, wallboard and the like.
The curable compositions can be applied by any conventional
~ethod, including brushing, dipping, rolling, flow coating, roll coating,
spraying and the like. Conventional spray techniques and equipment can be
utilized.
The curable compositions of the invention can be cured by baking
at moderate or elevated temperatures if desired. However, one advantageous
property of these curable compositions is that they can be cured by drying
in air at ambient temperature without the use of heat. As will be evident,
ambient temperature curable compositions are of considerable advantage in
that they provide for significant energy savings in comparison to composi-
'tions which require elevated temperatures Eor curing.
The examples which ~ollow are illustrative of the invention with
composition B of Exa;nple ~Ir repr~senting a preferred embodinent.
1135C)10
EXA~IPL.E I
A coating compositioll is formu1.1ted in the fo11Owing manner.
Twer1ty-five (25.0) grams of a potassium hydroxide solution (40,'. solids)
and 56.4 grams water are mixed together. The resultant solution is mixed
with 62.0 grams oE titanium dioxide pigment (Titrnox 2060, available from
Titanium In~ernational Corp.), 8.0 grams of pigment (Shepherd Green #5,
available from Shepherd Chem. Co.) and 33.0 grams of pigment (barium
metaborate, avaiLable from Buckman Laboratories as Busan llMl). Coors
beads are added to the mixture, followed by a 15 minute grind.
The beads are removed to give a pigment grind having a medium
viscosity and little pigment flocculation as evidenced by the presence of
only slight "puff" and "hang-up". Puff is defined as being false body, or
a high amount of viscosity at low shear rates, that results from pigment
flocculation. Hang-up results from the puff. Hang-up is evidenced by
paint clinging to the side of a container while paint in the center is
being mixed or sheared by the action of the mixer blade. Puff and hang-up
are both undesirable.
Next, 350.0 grams of potassium silicate (mole ratio of sio2:~2o = 3.9,
29.1% solids) is added to the pigment grind, follo~ed by 76.0 grams of mica
(Micro~ica ClO00, availabLe from English ~ica Corp.), lO.0 grams of --
clay (Attagel 40, available from ~inerals and Chemicals Phillipp Corp.),
4.0 grams of sodium carboxymethyl cellulose (available from Hercules
Chemical Co. as 12M8 grade) and 3.0 grams of polyethylene oxide (Polyox
WS~-205, available from Union Carbide Corp.). This loixture is rnixed for 15
~rminutes. The final composition is as follows:
~ 1350~
Percent
Pot3ssium silicate (solids) 23.23
~ater 72.89
Potassium hydroxide tsolids) 2.28
Sodium carboxymethyl cellulose 0.92
Polyethylene o~ide 0.68
100. 00
Pigment (53~ PVC)
Titanium dioxide 32.81
Shepherd Green #5 4.23
Barium metaborate 17.46
Mica 40.21
Clay 5.29
100 . 00
The composition has a smooth consistency and no puff or hang-up.
The compositions are next coated onto a prepainted plasterboard
substrate and evaluated for pigment dispersibility. This is done by
first applying a base coat (application made all in one direction), allowing
it to dry and then applying a second coat (application made in horizontal
and vertical directions to the base coat). A visual evaluation of the
coated substrate indicates the coating compositions have good color uni-
formity and good lapping characteristics.
E~IPLE II
Co~ting CompositiOnS are formulated to show the e~ect potassium
hydroxide has in compositions containing potassiurrl silicate and aluminum
ethylenedianine tetraacetate complerc. The compositiolls contain the
following components:
-- 10 --
11;~501a~
COmDOnellt _ npositions (7 ?
A B C
Potassium siLicate (mvle ratio of
SiO2:~20=3.3, solids~ 20.86 20.86 20.86
Water 75.29 74.72 74;14
Aluminum ethylenediamine tetra-
acetate complex (solids) 1.80 l.80 1.80
Potassium hydro~ide ~solids) -- 0.57 1.15
Defoa~er ~1) 0.S2 0.52 0.52
Sodium carboxymethyl cellulose (2)1.39 1.39 1.39
Surfactant (3) 0.14 0.14 0.14
i00. 00100 . 00100. 00
55% 54% 53%
Pigment (Z PVC)
Titanium dio~ide (4) 56.00 56.00 56.00
Clay (4) 5.33 S.33 5.33
Mica (3~5 ~esh) 38.67 38.67 38.67
100.00 100.00 100.00
(1) Available from Nopco Div. of Diamond Shamrock Cv. as Foamaster ~.*
(2) Available from ilercules Chemical Co. as 7M8S grade.
(3) Available from De~ter Chemical Co. as Strodex PK-90.*
(4) Same as used in ~xample I.
Composition A has noticeable puff~ hang-up and the appearance of
a gelatinous structure. Composition B has no puff and a slight, but accepta-
ble, hang-up, while Composition C has no puff and very slight hang-up.
Brush application of the compositions to a plasterbvard substrate
shows Composition A to exhibit a medium drag during the application.
; The gelatinous structure of the composition (this being an indication of
puff) broke do~n on repeated brushings. Compositions B and C exhibit only
lo~-medium drag durin~ brush application and the respective paint films
show no indication of an objectionable gelatinous structure.
* Trade Mark
-- 11 --
'~'
, ~ ~
50~0
EXA.~PI.~ III
This e~.imple illustrates the use of sodium hydroxide and potassium
hydro~ide as base materials in the compositions of the invention. The
compositions are made following the procedure of Example I:
Percent
A B
Potassium silicate (mole ratio of
SiO2:K2o = 3.9, solids) 23.30 23.30
Water 74.05 73.68
Sodium aluminate 0.13 0.13
Sodium hydroxide (solids) 0.91 ---
Potassium hydroxide (solids) ~-- l.Z8
Sodium carboxymethyl cellulose (1) 0.92 0.92
Polyethylene oxide (1) 0.69 0.69
lOO.OU 100.00
Pigment (54~ PVC for Compositions A and B)
Titanium dioxide (1) 32.80
Shepherd Green ~5 (1~ 4.23
Barium metaborate (L) 17.46
Mica (1) 40.21
Clay (1) 5.29
100 . UO
(1) As used in ~xample I.
Composition ~ is made by first blending 14.6 grams sodium hydroxide
solution (27.3% solids), 0.57 grams sodium aluminate and 60.0 grams water.
This blend has added to it 49.0 grams water, 62.0 grams titanium dioxide,
8.0 grans Shepherd Green ~5 pigment and 33.0 grams barium metaborate and is
then ~round together wi~h Coors beads for 15 minutes. A poreioll (150.0 gralns)
of the potassium siLicate is next added. A~ter removin~ the Coors beads, a
- 12 -
11;~5010
blend of 76.0 grams of mica, 10.0 grams clay, 4.0 grams sodium carboxymethyl
cellulose alld 3.0 gr;lms of the surfact.lnt is added. The mixture has next
added to it the balance of the potass;um silicate (200.0 grams) to get the
finaL coating composition. The composition has only slight puff and no
hang-up. -
Composition B is made in a similar manner with the substitution
of potassium hydroxide for the sodium hydroxide.
The compositions when painted on a substrate in the manner oE
~xanple I and visually tested for color uniforin;ty and lapping proved to
be satisfactory. Composition B does have better cure than Com.position ~ as
evidenced by B's film having better water-resistance and durability.
E~IPLE IV
This exampie illustrates the advantages of the invention when
sodium nethylsiliconate is used as the base material. Two compositions,
one being a control, are forrnulated as follows:
Components Cornpositions (%)
.
A B
Potassium silicate (mole ratio of
sio2:x2o = 3.9, solids) 23.23 23.23
Water 74.26 71.98
Sodium aluminate 0.13 0.13
Potassium hydroxide (solids) 0.11 O.IL
Sodium methylsiliconate (2) -- 2.28
Glycerine 1.14 1.14
Defoamer (1) 0.34 0.34
Sodium carboxymettlyl cellulose (5) 0.68 0 r 68
Thickener (3) O~ll O.Ll
10() . ()01~0 . 00
- 13 -
~ 50~0
52% 52%
Pir,lnent (% PVC)
Titanium dioxide (5) 34.85 34.85
Inoroanic pigment (4) 3.88 3.88
Barium metaborate (5) 18.55 18.55
~1ica (5) 42.72 42.72
100 . 00 100 . 00
(1) Available from SWS Silicones, Inc. as SWS-214.*
(2) Available from Dow Corr.ing Corp. as Dow Corning 772.*
~3) Available from B. F. Goodrich Chemical Co. as Carbopol 910*-
(4) Available from Ferro Chemical Co. as Ferro V3285*
(5) Sa~e as used in Example I
The compositions are made by making a soLution o 0.57 grams
sodium aluminate, 0.5 grams potassium hydroxide and 50.0 grams water and
blending with additional water (27.3 grams for Composition A and 19.0 ~rams
for Composition B), 5.0 gra~s glycerine, and 1.5 grams defoa~ner. Ten
(10.0) grams sodium methylsiliconate is added to Composition B. The
remaining components ~re added in the following order: 62.0 grams titanium
dioxide, 6.9 grams inorganic pigment, 33.0 grams barium metaborate, 3.0
grams C~IC, blended for 10 minutes, 350 grams potassium silicate added under
agitation, 76.0 grams mica a~d 0.5 grams thickener and then the total
cornposition blended for 10 minutes.
At the end of the blending, Composition ~ exhibited a moderate puff
and no hang-up while Composition B exhibited a trace of pufi and no hang-up.
Plasterboard substrates, as in Example I, are next painted with
each of ehe compositions. rne color uniformity of the ilm formed by Compo-
sition A is very good while that painted with Cornpositioll B is excellent.
Composition A's fiLm has a moderate ~ensity of small lumps of floccul3ted
piOment wllile Cornposition B's filln has none.
* Trade Mark
- ~4 -
:~i3S~
I~ X~ 'L.li: V
Sodium orthosilicate is useci in varyin~ levels in this example
to sllow the effect it has on the coating compositions and Eilms rormed
therefrom. The compositions are as follows:
Component Compositions (%)
A B C D E F
Potassium silicate (mole
ratio of SiO2:K20 =
3.9, solids) 23.4723.47 23.47 23.4723.4723.47
Wat-r 73.0172.78 72.55 72.0971.1969.40
Sodium aluminate 0.13 0.13 0.13 0.13 0.13 0.13
Potassium hydroxide (solids) 0.12 0.12 0.12 0.12 0.12 0.12
Sodium orthosilicate
pentahydrate -- 0.23 0.46 0.92 1.82 3.61
Citric acid 0 09 0 09 0 09 0 09 0 09 0 09
~minopropyl propanol 0.23 0.23 0.23 0.23 0.23 0.23
Surfactant (1) 0.97 0.97 0.97 0.97 0.97 0.97
Surfactant (2) 0.14 0.14 0.14 0.14 0.14 0.14
De~oamer (3) 0.23 0.23 0.23 0.23 0.23 0.23
PoLyethylene o~ide (4)0.690.69 0.69 0.69 0.69 0.69
Sodium carboxjmethyl cellulose(4)0.92 0.92 0.92 0.92 0.92 0.92
100.00100.0010().00100.00 100.00 100.00
52% 52% 52% 52% 51~o 50,~
Pi~Jment (~ PVC)
Titanium dioxide (4)32.8032.8032.80 32.8032.8032.80
Shepherd Green #5 (4) 4.23 4.23 4.23 4.23 4.23 4.23
Barium metaborate (4) 17.46 17.46 17.4617.4617.46 17.46
Mica (4) 40.2140.21 40.21 40.2140.2140.21
Clay (4) 5.29 5.29 5.29 5.29 _5.29 5.29
10~ 0.00 10U.'~ 100.~0 100.00 100.~0
- 15 -
11;~5010
(1) Noniollic surfactant available froln ~SF-Wyandotte Co. as Tetronic
304. *
~2) Nonionic surfactant available from Rohm & Haas Co. as Triton
X4~.*
(3) Available from SWS Silicones, Inc. as SWS-2L4.
~4) Same as used in Example I.
The viscosities of the compositions are measured with a Stormer
Yisco;neter and are graded for color uniformity using a scale of 0-100 wi~h
0 being the poorest and 100 being the best. Ihe gelatinous structure
is visually estimated as noted. --
Composition Viscosity Color Uniformity Gelatinous
(Krebs units) Ratinv Structure
_ _
A 106 27 slight-moderate
E~ 105 42 " "
C 102 33 slight
D 97 38 "
E 83 67 none
F 82 98 "
The above tests indicate increasing the level of sodium ortho-
silicate decreases the viscosi~y, improves color uniformity and reduces ehe
formation of an objectionable gelatinous structure in the compositions.
Example VI
This example shows the advantage o~ mi~ing pigment and base
together prior to combining with silicate binder. Two compositions ~re
formulated. Each has the following composition:
* Trade Mark
' '~',-
. . .
il;~50~0
Percent
Potassium silicate (molar ratio of
SiO2:~2O = 3.9, solids) 23.79
Water 70.16
Sodium aluminate 0.13
Potassium hydroxide (solids) 0.12
Sodium methylsiliconate (1) 2.90
Glycerine 1.17
Defoamer (1) 0.35
Aminomethyl propanol 0.28 - _
Citric acid 0.12
Nonionic surfactant (2) 0.16
Sodium carboxymethyl cellulose 0.70
Thickener (1) 0.12
100.00 - -
Pigment (55% PVC)
Titanium dioxide (1) 39.75
Shepherd #125 Blue (3) 4.42
Barium metaborate (1) 14.74
Mica (1) 41.09
ioo. oo
(1) Same as used in Example IV.
(2) Available from Rohm & Haas Co. as Triton X45.
(3) Available from Shepllerd Chemical Co.
One composition is made by blending the (a) sodium methylsili- -
conate with the water, sodium aluminate, potassium hydroxide, glycerine,
defoamer, aminomethyl propanol, citric acid and nonionic surfactant with
(b) pigments and then combining the blend with the remaining components.
No hang-up or puff is observed at any stage of the formulatioil making;
the composition has a smootn consistency at all stages.
11350~0
A second compos;tion is made iderltical to the first with the
e~ception being the post aclditioll of the sodiu[D methylsiliconate to a blend
oE all the other remaining co~mponents, Eollowed by agita~ion. rhe final
compositioll has a smooth non-gelatinous consistency, free of puff and
hang-up; however, heavy puEE and hang-up are noticed in the composition
pr_or to the addition of the siliconate. This ilLustrates the advanta~e of
adding the base to the pigment prior to combining with silicate.
rhe above examples illustrate the advantages obtained from the
present invention. rne examples all show that the inclusion of a base in a
silicate-containing composition improves the appearances of resultant -
coatings.
18 -
