U.S. patent application number 16/707360 was filed with the patent office on 2021-03-18 for inorganic phosphate ceramics and coatings.
The applicant listed for this patent is Latitude 18, Inc.. Invention is credited to Sameerkumar Vasantlal Patel.
Application Number | 20210079230 16/707360 |
Document ID | / |
Family ID | 1000005430083 |
Filed Date | 2021-03-18 |
United States Patent
Application |
20210079230 |
Kind Code |
A9 |
Patel; Sameerkumar
Vasantlal |
March 18, 2021 |
INORGANIC PHOSPHATE CERAMICS AND COATINGS
Abstract
This disclosure relates to hydrophobic metal phosphate ceramic
comprising a Group IV element of silicon, germanium, tin, or lead
having at least one hydrocarbon covalently bonded thereto. Methods
of providing water proofing and/or anti-corrosion protection are
provided.
Inventors: |
Patel; Sameerkumar Vasantlal;
(Raleigh, NC) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Latitude 18, Inc. |
Sims |
NC |
US |
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|
Prior
Publication: |
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Document Identifier |
Publication Date |
|
US 20200109296 A1 |
April 9, 2020 |
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Family ID: |
1000005430083 |
Appl. No.: |
16/707360 |
Filed: |
December 9, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14768127 |
Aug 14, 2015 |
10501641 |
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PCT/US13/26403 |
Feb 15, 2013 |
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16707360 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C04B 24/42 20130101;
C23C 22/76 20130101; C04B 28/348 20130101; C04B 2111/2092 20130101;
C23C 22/62 20130101; C04B 28/34 20130101; C09D 5/16 20130101; C23C
22/66 20130101; C23C 22/60 20130101; C09D 1/00 20130101; C09D 5/08
20130101 |
International
Class: |
C09D 5/08 20060101
C09D005/08; C04B 28/34 20060101 C04B028/34; C23C 22/60 20060101
C23C022/60; C04B 24/42 20060101 C04B024/42; C23C 22/66 20060101
C23C022/66; C23C 22/62 20060101 C23C022/62; C23C 22/76 20060101
C23C022/76; C09D 5/16 20060101 C09D005/16; C09D 1/00 20060101
C09D001/00 |
Claims
1-45. (canceled)
46. A hydrophobic metal phosphate ceramic comprising: a Group IV
element of silicon, germanium, tin, or lead covalently bonded to
the metal phosphate ceramic, the Group IV element having at least
one hydrocarbon moiety covalently bonded thereto; and wherein, the
at least one hydrocarbon moiety is independently, C.sub.1-20 alkyl,
phenyl, aryl.
47. A method of forming a hydrophobic metal phosphate ceramic, the
method comprising combining at least one acidic phosphate component
with at least one sparingly soluble basic oxide or hydroxide
component; at least one hydrophobic agent comprising at least one
hydrophobic agent is at least one organosiliconate or is at least
one polymeric or oligomeric siloxane with reactive silanol and/or
alkoxyl groups covalently bonded thereto; and one or more of an
inorganic mineral silicate, wollastonite, talc, amorphous magnesium
silicate, amorphous calcium silicate, diatomaceous earth,
aluminosilicate, olivine, calcined Kaolin, mullite, colloidal
silica, silicon dioxide, or amorphous silicon dioxide.
48. The method of claim 47, wherein the at least one
organosiliconate is a salt; or a mono-, di-, or tri-alkyl
siliconate.
49. A metal phosphate ceramic precursor formulation comprising the
following: at least one hydrophobic agent, wherein the hydrophobic
agent is of the general formula (I) or (II) or (III) or (IV):
##STR00005## where: R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are,
independently, hydrogen, C.sub.1-20 alkyl, phenyl, aryl; where
alkyl includes straight-chain, branched, cyclic or acylic alkyl, or
haloalkyl; Y.sub.1, Y.sub.2, and Y.sub.3 is, independently,
hydroxyl, C.sub.1-4 alkoxy, phenoxide, or halogen; or, Y.sub.1,
Y.sub.2, and Y.sub.3 is, independently, an alkali metal salt, an
ammonium salt, an alkylammonium salt, a phenylammonium salt, or an
alkylphenylammonium salt of Si--OH; b is 0-21; n is 1,000 to
1,000,000; m is 0-1,000; and Z is sodium or potassium; at least one
acidic phosphate component in combination with one or more of
formula (I), (II), and (III); and at least one sparingly soluble
basic metal oxide or hydroxide in combination with formula (IV),
the at least one sparingly soluble basic metal oxide or hydroxide
in molar excess to that of the at least one sparingly soluble
acidic phosphate component.
50. The metal phosphate ceramic precursor formulation of claim 49,
further comprising one or more of an inorganic mineral silicate,
wollastonite, talc, amorphous magnesium silicate, amorphous calcium
silicate, diatomaceous earth, aluminosilicate, olivine, calcined
Kaolin, mullite, colloidal silica, silicon dioxide, and amorphous
silicon dioxide.
51. The metal phosphate ceramic precursor formulation of claim 49,
wherein formula (IV) is at least one soluble basic inorganic salt
selected from an alkylsiliconate.
52. A method of preventing or reducing fungal and/or bacterial
growth on a surface, the method comprising contacting a surface
with an aqueous composition comprising: at least one inorganic
phosphate; at least one sparingly soluble metal oxide/hydroxide in
molar excess amount to that of the at least one sparingly soluble
inorganic phosphate; at least one sparingly soluble inorganic
mineral at least one sparingly soluble inorganic mineral, wherein
the at least one sparingly soluble inorganic mineral is one or more
of an inorganic mineral silicate, wollastonite, talc, amorphous
magnesium silicate, amorphous calcium silicate, diatomaceous earth,
aluminosilicate, olivine, calcined Kaolin, mullite, colloidal
silica, or amorphous silicon dioxide; and optionally, at least one
soluble basic inorganic salt; and contacting a surface with the
combined aqueous composition, wherein the surface, after
contacting, provides a basic environment of at least pH 9 to pH 14;
and preventing or reducing fungal and/or bacterial growth on the
surface.
53. The method of claim 52, comprising the at least one soluble
basic inorganic salt selected from an alkylsiliconate, or one or
more of an alkali metal or alkali earth metal salt of a phosphate
or a silicate.
54. A method of preventing or reducing attachment of Mollusca on a
surface, the method comprising: combining an aqueous composition
comprising: at least one inorganic phosphate; at least one
sparingly soluble metal oxide/hydroxide in molar excess amount to
that of the at least one sparingly soluble inorganic phosphate; at
least one sparingly soluble inorganic mineral, wherein the at least
one sparingly soluble inorganic mineral is one or more of an
inorganic mineral silicate, wollastonite, talc, amorphous magnesium
silicate, amorphous calcium silicate, diatomaceous earth,
aluminosilicate, olivine, calcined Kaolin, mullite, colloidal
silica, or amorphous silicon dioxide; and optionally, at least one
soluble basic inorganic salt; contacting a surface with the
combined aqueous composition, wherein the surface, after
contacting, provides a basic environment of at least pH 9 to pH 14;
and preventing or reducing attachment of Mollusca on the
surface.
55. The method of claim 54, wherein the Mollusca is a fresh water
mussel, a zebra mussel or quagga mussel.
56. The method of claim 54, wherein the surface is associated with
a ship hull or a water treatment facility.
57. The method of claim 54, comprising the at least one soluble
basic inorganic salt selected from an alkylsiliconate, or one or
more of an alkali metal or alkali earth metal salt of a phosphate
or a silicate.
Description
TECHNICAL FIELD
[0001] This disclosure relates to hydrophobic metal phosphate
ceramic comprising a Group IV element of silicon, germanium, tin,
or lead having at least one hydrocarbon covalently bonded thereto.
Specifically, the inorganic phosphate ceramic composition is
prepared from one or more acidic phosphate components, a molar
excess of one or more of alkaline metal oxide or metal hydroxide
components, and an effective amount of one or more of a Group IV
element of silicon, germanium, tin, or lead having at least one
hydrocarbon covalently bonded thereto.
BACKGROUND
[0002] Providing waterproofing to ceramic and or cementitious forms
or coatings has proven elusive. Typically, water resisting
materials are included in the pre-set formulation in the desire to
have them bloom or migrate to the surface upon or after setting.
Such techniques result in the dissipation of the water repellency
properties over time. The basic nature of such materials has
resisted most attempts at incorporating materials directly into the
ceramic/cement structure without altering, in a negative way, the
properties of the ceramic/cement. Providing bacterial and/or mold
resistance to metallic and non-metallic surfaces, without the use
of fungicidal and bactericidal chemicals in the form of ceramic
coatings has proven elusive. Typically, one or more fungicides and
bactericides are included in the pre-set ceramic or cement
formulation in the desire to have them bloom or migrate to the
surface upon or after setting. Such techniques result in the
dissipation of the fungicidal/bactericidal properties over time and
further require using an excess of such additives. Moreover, the
use of specific fungicides and bactericides or classes of
fungicides and bactericides ultimately results in resistant strains
of these organisms.
SUMMARY
[0003] In a first embodiment, metal phosphate ceramic is provided.
The metal phosphate ceramic comprising a Group IV element of
silicon, germanium, tin, or lead having at least one hydrocarbon
moiety covalently bonded thereto.
[0004] In a first aspect of the first embodiment, the at least one
hydrocarbon moiety is independently, C.sub.1-20 alkyl, phenyl,
aryl; where alkyl includes straight-chain, branched, or cyclic
alkyl, haloalkyl (e.g. fluoro- or chloro alkyl).
[0005] In another aspect, alone or in combination with any one of
the previous aspects of the first embodiment, the Group IV element
is directly or indirectly covalently and/or mechanically bonded to
the metal phosphate ceramic.
[0006] In another aspect, alone or in combination with any one of
the previous aspects of the first embodiment, the Group IV element
is silicon.
[0007] In another aspect, alone or in combination with any one of
the previous aspects of the first embodiment, the composition
further comprises, chemically bound, one or more inorganic mineral
silicate, wollastonite, talc, amorphous magnesium silicate,
amorphous calcium silicate, diatomaceous earth, silicon dioxide,
calcined kaolin, colloidal silica, and amorphous silicon
dioxide.
[0008] In a second embodiment, method of forming a hydrophobic
metal phosphate ceramic is provided. The method comprises
combining: (i) at least one sparingly soluble acidic phosphate
component; (ii) at least one sparingly soluble basic oxide or
hydroxide component; and (iii) at least one hydrophobic agent
comprising a Group IV element of silicon, germanium, tin, or lead
having at least one hydrocarbon covalently bonded thereto. The
hydrocarbon is independently, C.sub.1-20 alkyl, phenyl, aryl; where
alkyl includes straight-chain, branched, or cyclic alkyl,
haloalkyl.
[0009] In one aspect of the second embodiment, the Group IV element
is silicon.
[0010] In another aspect, alone or in combination with any one of
the previous aspects of the second embodiment, the at least one
hydrophobic agent is at least one polymeric or oligomeric siloxane
with reactive silanol and/or alkoxyl groups, or, is at least one
organosiliconate.
[0011] In another aspect, alone or in combination with any one of
the previous aspects of the second embodiment, the at least one
acidic phosphate component is at least one of mono potassium
phosphate, mono calcium phosphate, and their hydrates. The at least
one sparingly soluble basic component is at least one of magnesium
oxide, barium oxide, zinc oxide, calcium oxide, copper oxide, and
hydroxides thereof, or, independently or in combination, magnesium
brine containing an effective amount of magnesium hydroxide.
[0012] In another aspect, alone or in combination with any one of
the previous aspects of the second embodiment, the at least one
acidic phosphate component is at least one of alkali metal
dihydrogen phosphate MH.sub.2PO.sub.4, alkali earth dihydrogen
phosphate M(H.sub.2PO.sub.4).sub.2 or its hydrate, and mixtures
thereof. The at least one acidic phosphate component can be at
least one of mono potassium phosphate (MKP), mono calcium
phosphate, and their hydrates.
[0013] In another aspect, alone or in combination with any one of
the previous aspects of the second embodiment, the at least one
sparingly soluble basic component is one or more of magnesium
oxide, magnesium hydroxide, calcium oxide, and calcium
hydroxide.
[0014] In another aspect, alone or in combination with any one of
the previous aspects of the second embodiment, the at least one
acidic phosphate component is one or more of mono potassium
phosphate, mono calcium phosphate, and their hydrates, and the at
least one sparingly soluble basic component is one or more of
magnesium oxide, magnesium hydroxide, calcium oxide, and calcium
hydroxide.
[0015] In another aspect, alone or in combination with any one of
the previous aspects of the second embodiment, the method further
comprising combining one or more of an inorganic mineral silicate,
wollastonite, talc, amorphous magnesium silicate, amorphous calcium
silicate, diatomaceous earth, silicon dioxide, and amorphous
silicon dioxide.
[0016] In another aspect, alone or in combination with any one of
the previous aspects of the second embodiment, the combining is
performed with high shear.
[0017] In a third embodiment, a metal phosphate ceramic precursor
formulation is provided. The formulation comprising: at least one
sparingly soluble acidic phosphate component; at least one
sparingly soluble metal oxide/hydroxide component in molar excess
to that of the at least one sparingly soluble acidic phosphate
component; at least one sparingly soluble inorganic mineral; and at
least one hydrophobic agent in combination with one or both of the
at least one sparingly soluble acidic phosphate component and the
at least one sparingly soluble basic metal oxide or hydroxide
component, the hydrophobic agent comprising at least one Group IV
element having a hydrocarbon covalently bonded thereto, where the
Group IV element is one or more of silicon, germanium, tin, or
lead.
[0018] In an aspect, alone or in combination with any one of the
previous aspects, the hydrophobic agent is of the general formula
(I) or (II) or (III) or (IV):
##STR00001##
where:
[0019] R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are, independently,
hydrogen, C.sub.1-20 alkyl, phenyl, aryl; where alkyl includes
straight-chain, branched, cyclic or acylic alkyl, or haloalkyl;
[0020] Y.sub.1, Y.sub.2, and Y.sub.3 is, independently, hydroxyl,
C.sub.1-4 alkoxy, phenoxide, or halogen; or, Y.sub.1, Y.sub.2, and
Y.sub.3 is, independently, an alkali metal salt, an ammonium salt,
an alkylammonium salt, a phenylammonium salt, or an
alklyphenylammonium salt of Si--OH;
[0021] b is 0-21; n is greater than 1,000 to 1,000,000;
[0022] m is 0-1,000; and
[0023] Z is sodium or potassium. The precursor may further comprise
one or more of a sparingly soluble inorganic mineral silicate,
wollastonitc, talc, amorphous magnesium silicate, amorphous calcium
silicate, diatomaceous earth, silicon dioxide, calcined kaolin,
colloidal silica, and amorphous silicon dioxide.
[0024] In a fourth embodiment, an aqueous composition as a slurry
or suspension is provided. The aqueous composition comprises, the
aqueous composition comprising: at least one sparingly soluble
metal oxide or metal hydroxide; at least one sparingly soluble
inorganic phosphate; at least one sparingly soluble inorganic
mineral; and at least one soluble basic inorganic salt.
[0025] In an aspect, alone or in combination with any one of the
previous aspects, the at least one acidic phosphate component is at
least one of mono potassium phosphate, mono calcium phosphate, and
their hydrates, and the sparingly soluble basic component is at
least one of magnesium oxide, magnesium hydroxide, calcium oxide,
or calcium hydroxide.
[0026] In an aspect, alone or in combination with any one of the
previous aspects, wherein the at least one sparingly soluble
inorganic mineral is one or more of an inorganic mineral silicate,
wollastonite, talc, amorphous magnesium silicate, amorphous calcium
silicate, diatomaceous earth, aluminosilicate, olivine, calcined
Kaolin, mullite, colloidal silica, silicon dioxide, or amorphous
silicon dioxide.
[0027] In an aspect, alone or in combination with any one of the
previous aspects, the aqueous composition further comprises the
hydrophobic agent described above.
[0028] In a fifth embodiment, a method of preventing or reducing
fungal and/or bacterial growth on a surface is provided. The method
comprising contacting a surface with the metal phosphate ceramic of
any one of aspects of above, wherein the surface, after contacting,
provides a basic environment of at least pH 9; and preventing or
reducing fungal or bacterial growth on the surface. In one aspect,
the surface is associated with a medical article, medical device,
medical equipment, hydroelectric dam, ship hull, or structure.
[0029] In a sixth embodiment, method of preventing or reducing
attachment of Mollusca on a surface is provided. The method
comprising: combining the metal phosphate ceramic precursor
formulation of any of the previous embodiments or aspects;
contacting a surface with the combined metal phosphate ceramic
precursor formulation, wherein the surface, after contacting,
provides a basic environment of at least pH 9 to pH 14; and
preventing or reducing attachment of Mollusca on the surface. In
one aspect, the Mollusca are zebra mussel or quagga mussel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] NONE
DETAILED DESCRIPTION
[0031] The present disclosure provides, among other things, a
uniquely-suited, hydrophobic phosphate-based composite coatings
having hydrophobic properties that minimize or reduce the
penetration of water and/or corrosion of metals, for example steels
and iron and make it unnecessary to use alloys of steel or iron
such as galvanized (zinc coated) compositions or chrome plated
compositions.
[0032] As used herein, the phrases "acidic phosphate component" and
"acidic phosphate precursor" and "acid component" and "Part A" are
used interchangeably unless otherwise indicated. As used herein,
the phrase "sparingly soluble acidic phosphate component" refers to
inorganic phosphates of chemical formula
A.sup.m(H.sub.2PO.sub.4).sub.m.nH.sub.2O, where A is metal cation,
or mixtures thereof; where m=1-3, and n=0-6.
[0033] As used herein phrases "sparingly soluble basic metal oxide
and sparingly soluble basic metal hydroxide component" and
"sparingly soluble basic component" and "sparingly soluble alkaline
component" and "sparingly soluble alkaline precursor" are used
interchangeably unless otherwise indicated. The phrases "sparingly
soluble basic component" and "sparingly soluble alkaline component"
and "sparingly soluble alkaline precursor" are inclusive of
materials that are sparingly soluble, e.g., have low solubility
product constants in aqueous media, e.g., e.g., solubility
constants (Ksp) of at least 10.sup.-4, 10.sup.-5, 10.sup.-6,
10.sup.-7, 10.sup.-8, 10.sup.-9 or smaller. In one aspect, the
solubility of the sparingly soluble basic component is less than
about 0.1 moles/liter water. In one aspect, the phrases sparingly
soluble basic metal oxide and sparingly soluble basic metal
hydroxide component" and "sparingly soluble basic component" and
"sparingly soluble alkaline component" and "sparingly soluble
alkaline precursor" are exclusive of materials that are readily
soluble, e.g., have high solubility product constants in aqueous
media.
[0034] As used herein, the phrase "soluble basic inorganic salt" is
inclusive of materials that are readily aqueous soluble, e.g.,
solubility constants (Ksp) of at least 10.sup.-3, 10.sup.-2 or
greater, and have an aqueous pH of between about 10 to about 14,
between about 11 to 14, between about 12 to 14, or between about 13
to 14. In one aspect, the solubility of the soluble basic inorganic
salt is greater than about 0.1 moles/liter water, or greater than
about 1 moles/liter water. "Basic inorganic salt of an inorganic
acid" and "basic inorganic salt" include, by way of example, one or
more of a bi-, and/or tri-alkali and/or alkali earth salt of
phosphate (PO.sub.4.sup.-3), silicate (SiO.sub.4.sup.-3), alkyl
silicate (alkyl-SiO.sub.3.sup.-3), or aluminate
(Al.sub.2O.sub.4.sup.-2). Other readily aqueous soluble basic
inorganic salts, providing an aqueous pH of greater than 10,
greater than 11, greater than 12, greater than 13, or an aqueous pH
of between 10 and 14, can be used, for example, potassium
hydroxide, and to a lesser extent, sodium hydroxide. The amount of
basic inorganic salt present in an aqueous mixture of the sparingly
soluble basic metal oxide/hydroxide component, alone or in
combination with one or more sparingly aqueous soluble inorganic
silicates, can be between about 1 weight percent to about 95 weight
percent, or about 3-75 weight percent, or 5-50 weight percent
solids.
[0035] As used herein, the phrase "aqueous mixture" refers to a
combination of at least a quantity of water and at least one of the
acid phosphate or sparingly soluble basic component. For example,
the aqueous mixture can contain mostly water and suspended,
dispersed, or slurried components, and may also contain non-aqueous
components such as alcohols and other solvents. Preferably, water
is the major liquid phase.
[0036] The amount of solids (e.g., the acid phosphate, sparingly
soluble basic component and/or other solids) present in the aqueous
mixture can be between 1 weight percent to about 95 weight percent,
preferably 35-90 weight percent, or 50-80 weight percent
solids.
[0037] In one aspect, the hydrophobic agent is of the general
formula (I) or (II) or (III):
##STR00002##
where x.gtoreq.1.ltoreq.3; R.sub.1, R.sub.2, R.sub.3, and R.sub.4
are, independently, hydrogen, C.sub.1-20 alkyl, phenyl, aryl; where
alkyl includes straight-chain, branched, or cyclic alkyl,
haloalkyl; where Y.sub.1, Y.sub.2 is, independently: hydroxyl,
C.sub.1-4 alkoxy, halogen, phenoxide, or, Y.sub.1, Y.sub.2 is an
alkali metal salt with, ammonium salt, alkylammonium salt,
phenylammonium salt, or alklyphenylammonium salt of Si--OH; n is
greater than 1,000 to 1,000,000; m is 0-1,000. Formulas (I) or (II)
can be solids or liquids, and can be used neat or in aqueous
emulsions (including surfactants). Combinations of two or more of
formulas (I), (II), and (III) can be used in any amount in Part A
and in Part B; or in any combination and amount with either Part A
or Part B, in both Part A or Part B; or only in Part A, or only in
Part B. Compositions of formulas I-III include where R.sub.1,
R.sub.2, R.sub.3, and R.sub.4 are, independently, a fluoroalkyl,
e.g., trifluoromethyl terminated alkyls of 1-20, 2-20, or 2-4
carbons. Other fluoroalkyls can be used.
[0038] In another aspect, the hydrophobic agent is of the general
formula (IV):
R.sub.tSi(O.sub.4-t).sup.4-t.Z.sub.4-t (IV);
where m.gtoreq.1.ltoreq.3; R.sub.1, R.sub.2, and R.sub.3 arc,
independently, C.sub.1-20 alkyl, phenyl, aryl; where alkyl includes
straight-chain, branched, or cyclic alkyl, unsubstituted, or
substituted with halogen; where Z is, independently, one or more of
an alkali metal cation, alkali earth cation, or ammonium cation.
Ammonium cation is inclusive of one or more of
tetra(alkyl,benzyl)ammonium cation, tri(alkyl,benzyl)ammonium
cation, di(alkyl,benzyl)ammonium cation tetra(benzyl)ammonium
cation, monoaalkylammonium cation, tetraalkylammonium cation,
triaalkylammonium cation, or dialkylammonium cation. Compositions
of formula IV include where R.sub.t is methyl, ethyl, (sec- or
tert-) butyl, where t=1 and Z is sodium or potassium. Compositions
of formula IV include where R.sub.t is a fluoroalkyl, e.g.,
trifluoromethyl terminated alkyls of 1-20, 2-20, or 2-4 carbons.
Other fluoroalkyls can be used. In one aspect, the alkylsiliconate
salt can be both the soluble basic inorganic salt and the
hydrophobic agent.
[0039] Combinations of two or more of formulas (I), (II), (III),
and (IV) can be used in any amount in Part A and in Part B; or in
any combination and amount with either Part A or Part B, in both
Part A or Part B; or only in Part A, or only in Part B. In one
aspect, the use of formula (IV) with a single, short chain alkyl,
(e.g., methyl or ethyl) as a alkali metal organosiliconate salt may
be used. While not to be held to any particular theory, formula
(IV) with a single, short chain alkyl is believed to provide an
organosiliconate moiety as an integrated component of the metal
phosphate ceramic where the size and/or nature of the alkyl group
imparts a minimum effect on the ceramic properties while optimizing
the hydrophobicity thereof.
[0040] In one aspect, the hydrophobic agent comprises one or more
siloxanes and/or polysiloxanes. A number of polysiloxanes, with
varying backbone structure are suitable for use as a precursor
component. With reference to Equation (1), various forms of
polysiloxanes, e.g. the M, T, Q, and D backbones, where R is,
independently, alkyl or aryl, are presented:
##STR00003##
[0041] In various aspects, the polysiloxane can comprise one or
more reactive functional groups. The polysiloxane can be mixed with
non-reactive silicone containing polymers. Examples of reactive
silicone containing polymers with reactive groups include, for
example, linear or branched polysiloxanes, and/or linear or
branched polysiloxanes with multiple reactive groups such as Si--H
(silicon hydride), hydroxy, alkoxy, amine, chlorine, and thiol
functional groups. Some specific examples of such linear or
branched polysiloxanes include functional group-terminated and/or
branched functional group polydimethyl siloxanes,
polydimethyl-co-diphenyl siloxanes and
polydimethyl-co-methylphenylsiloxanes. The reactive groups can be
located at one or both terminuses of the reactive silicone
polymers, and/or anywhere along the backbone and/or branches of the
polymer.
[0042] In one aspect, one or more of the hydrophobic agents can
comprise a silsesquioxane and/or polyhedral oligomeric
silsesquioxane moiety ("POSS moieties"). POSS moieties suitable for
the present disclosure are represented generally by Formula (1)
below:
##STR00004##
[0043] showing a representative example of an open cage, partially
condensed and closed cage, fully condensed POSS moiety, wherein the
R groups may be the same or different, optionally with at least one
of the R groups being a group having chemical functionality,
further described below. The R group may be the same or different,
selected from hydrogen, hydroxy, alkoxy, amine, chlorine, or thiol.
In the above aspects, at least one of the R groups can optionally
be a non-reactive group, which may be the same or different,
independently selected from substituted, branched, un-branched,
cyclic, or acyclic C.sub.1-30 alkyl, and aryl and/or substituted,
branched, or un-branched C.sub.6-30 substituted aryl groups.
[0044] "POSS moiety", as used herein is inclusive of polyhedral
oligomeric silsesquioxanes, and compounds, organic
polymers/oligomers, inorganic polymers/oligomers, and/or
organic-inorganic polymers containing one or more open and/or
closed cage silsesquioxane moieties, with any of the R groups
and/or chemical functional groups, described above. Examples of
suitable POSS moieties encompassed by the present disclosure
include, but are not limited to, open-cage and/or closed cage
molecules, having from zero up to and including eight non-reactive
or reactive sites, where each of the sites, independently, can be
substituted/un-substituted alkyl-, branched/un-branched alkyl-,
cyclic/acyclic alkyl-, hydroxyl-, alkoxyl-, amine-, halo/chloro-,
hydrogen-, thiol-, silanol-, aryl, substituted aryl, and/or
styrenyl-containing groups.
[0045] In one aspect, polymeric or oligomeric silicones, silanols,
and/or silicates with at least one silicon-carbon bond arc included
with the acidic phosphate and/or basic metal oxide/hydroxide
component of a metal phosphate ceramic. Introduction of an
effective amount of one or more of a polymeric or oligomeric
silicone, silanol, and/or silicate with at least one silicon-carbon
bond provides, in certain aspects, provides hydrophobic properties
to the metal phosphate ceramic. In other aspects, introduction of
an effective amount of one or more of a silicone, silanol, and/or
silicate with at least one silicon-carbon bond provides, in certain
aspects, a non-porous, hydrophobic phosphate ceramic product that
is essentially water proof. The introduction of an effective amount
of one or more of a polymeric or oligomeric silicone, silanol,
and/or silicate with at least one silicon-carbon bond provides, in
certain aspects, a phosphate ceramic coating for corrodible metals
suitable for use in corrosive environments and/or capable of
electrically isolating the metallic surface.
[0046] In addition to the management of the hydrophobicity, the
present disclosure provides manufacturing methods that optimize the
preparation of the acidic phosphate components and the sparingly
soluble basic components prior to combination so as to manage the
chemical reactions and/or pH of the chemical reactions of the
metallic surface and the acidic phosphate components and the
sparingly soluble basic components. The manufacturing methods
further improve the incorporation of polymeric or oligomeric
silicones, silanols, and/or silicates with at least one
silicon-carbon bond into the composition further providing
insoluble, non-porous phosphate coatings that can eliminate the
need for conventional pre- and/post-treatment of the metallic
surface.
[0047] Examples of the inorganic phosphate coatings provided herein
include a magnesium potassium phosphate coating, and calcium
potassium phosphate coating, either of which optionally contains
the one or more hydrophobic agents discussed above. In one aspect,
the coating comprises the hydrophobic agent chemically integrated
therewith. These compositions are disclosed herein for providing
metal phosphate ceramics, as well as coatings on steels, aluminum,
and other corrodible metals.
[0048] It has now been observed that certain hydrophobic agents,
such as, for example, polymeric or oligomeric silicones, silanols,
and/or organosiliconates with at least one silicon-carbon bond when
added to or formed "in-situ" with an acidic phosphate
component/sparingly soluble basic component formulation greatly
enhance the water resistance, water proofing, electric isolation,
and/or corrosion resistance of the coating.
[0049] It has also been observed that certain hydrophobic agents,
such as, for example, polymeric or oligomeric silicones, silanols,
and/or organosiliconates with at least one silicon-carbon bond, in
combination with one or more inorganic silicates, SiO.sub.2,
wollastonitc, and/or amorphous magnesium silicate, when added to or
formed "in-situ" with an acidic phosphate component/sparingly
soluble basic component greatly enhance the water resistance, water
proofing, electric isolation, and/or corrosion resistance of the
metal-phosphate ceramic.
[0050] The above hydrophobic metal-phosphate ceramic can be used as
monolithic forms, or as coatings that serve as a surface
preparation for further coating and/or painting, a function it
performs effectively with excellent adhesion. In contrast to the
conventional methods of passivating/corrosion protecting metal
surfaces, the present disclosure provides improving the
metal-phosphate ceramic, reducing its porosity and/or reducing its
crystallinity such that the hydrophobicity is controlled and/or
corrosion preventive aspects, and others, are chemically associated
with the metal-phosphate ceramic.
[0051] In one aspect, the aqueous suspension of acidic phosphate
component comprises one or more acid phosphate salts, optionally
comprising one or more hydrophobic agents, with or without
phosphoric acid, calcined kaolin, and/or colloidal silica, the
mixture having a pH between about 1 and about 6 (preferably being
between about 1.5 to about 5, more preferably between about 2 to
about 4).
[0052] The aqueous suspension of sparingly soluble basic component
comprises alkali minerals, optionally comprising one or more
hydrophobic agents, having a pH between about 8 to about 12,
preferably about 9 to about 14, more preferably a pH between about
11 to about 13. Hydrophobic agents alone or in combination with
wollastonite, amorphous magnesium silicate, silica, amorphous
silicon dioxide, diatomaceous earth, olivine, and the like can be
added to the acidic phosphate and/or the basic metal
oxide/hydroxide component.
[0053] Because of the difference in solubility, the acidic
phosphate component, with a higher solubility than that of the
sparingly soluble basic component, can enter into solution first or
in slight excess, and can react with the metallic surface (e.g.,
iron/steel) to provide metallic ions (e.g., ferrous ions) at the
surface and/or in the aqueous phosphate suspension, which is
relatively acidic at the metallic surface. As the sparingly soluble
basic component goes into solution, it can react with the acidic
phosphate component and/or the metallic ions, and chemically
combine with the metallic phosphate at the surface and/or in
solution. It is generally believed that the suspension can become
temporarily alkaline in the local environment of the metallic
surface, which may result in more acidic phosphate from the
suspension to enter into solution such that the local environment
about the metallic surface slurry becomes acidic again. This
acid-base equilibrium process can repeat multiple times, with the
system ultimately reaching a thermodynamic and/or kinetic
equilibrium at the metallic surface that is believed to be in the
alkaline range. In this process, it is further believed that the
hydrophobic agents, which are generally alkaline as aqueous
suspensions, can be chemically incorporated into the
metallic-phosphate and/or chemically bond to the metallic surface.
To be clear, such hydrophobic agents are not simply "fillers." The
hydrophobic agents are added and intended to chemically combine
with one or more of the acidic phosphate component, the sparingly
soluble basic component, and/or a metallic surface, and/or the
metallic phosphate moieties present and/or created. The hydrophobic
agents can be combined, synergistically, for example, with
inorganic silicates, such as wollastonite, talc, amorphous
magnesium silicate, amorphous calcium silicate, diatomaceous earth,
silicon dioxide, olivine, calcined kaolin, mullite, alumino
silicate, and amorphous silicon dioxide, which also can combine
with one or more of the acidic phosphate component, the sparingly
soluble basic component, and/or the metallic surface, and/or the
metallic phosphate moieties present and/or created. Other silicates
can be used.
[0054] During this equilibrium process the polymeric or oligomeric
silicones, silanols, and/or organosiliconates with at least one
silicon-carbon bond can hydrolyze and combine with the acidic
phosphate and/or basic metal oxide/hydroxide and/or with the one or
more inorganic silicates, SiO.sub.2, wollastonite, and/or amorphous
magnesium silicate.
[0055] In one aspect, the instant method provides for a treated
iron or steel surface, at least one iron-magnesium-phosphate moiety
is believed formed, e.g., a hydrophobic, hydrated magnesium
hydrogen iron phosphate, that is chemically distinct from
FePO.sub.4(2H.sub.2O)Fe.sub.3(PO.sub.4).sub.2(8H.sub.2O), and/or
Fe.sub.5H.sub.2(PO.sub.4).sub.2(4H.sub.2O) provided by conventional
iron phosphating processes, the latter being generally crystalline
and porous, the former having at least on silicon-carbon bond.
Additional compositions, including, polyphosphates, and/or
amorphous organo-Group IV moieties, as discussed above, as well as
inorganic metal-silicates, discussed below, can be present and
provide additional and/or synergistic water penetration and/or
corrosion protection.
[0056] The final pH of the metal phosphate ceramic or a coating
prepared from same can be provided in the passivation range of
steel, e.g., between about pH 9 and about pH 12, between about pH
9.5 and about pH 11.5, between about pH 10.0 and about pH 11.0,
between about pH 9.0 and about pH 10.5, between about pH 9.5 and
about pH 10.0, between about pH 10.0 and about pH 10.5. In one
aspect, the surface of a coated article can be provided with a
basic nature, for example between about pH 9 and about pH 12,
between about pH 9.5 and about pH 11.5, between about pH 10.0 and
about pH 11.0, between about pH 9.0 and about pH 10.5, between
about pH 9.5 and about pH 10.0, between about pH 10.0 and about pH
10.5 to prevent or inhibit bacterial and/or microorganism growth or
colonization on the surface of the coated article. The coated
article can be, for example, a medical article, ship hull, surface,
or water treatment facility component.
[0057] Similar conversion coatings can be provided for aluminum or
aluminum alloys using the methods and compositions herein
disclosed, and optionally, the addition of hydrophobic agents
selected from those which are optimal for aluminum or aluminum
alloys. Other corrosion inhibitors, in addition to or
independently, can be added to the acidic phosphate
component/sparingly soluble basic component composition prior to
set. While not to be held to any particular theory, it is believed
that the silicate can covalently bind to aluminum and providing an
anti-corrosion function, preventing or reducing oxidation of
aluminum to its corrosion product (e.g., aluminum oxide) and/or
reducing or eliminating mold and/or bacteria growth on its
surface.
[0058] Addition of other hydrophobic agents than those described
above, in the acidic phosphate/sparingly soluble basic component
composition, can be employed.
[0059] In one aspect, the instant compositions can be configured as
separate, atomizible, sprayable inorganic phosphate precursors that
can be sprayed at a relatively thin thickness. The compositions can
hold high solids contents and yet still hold the solids until
setting and thus avoiding the solids migrating or dislodging from
the point of application, e.g., down a wall, beam, curved surface,
or from a ceiling surface. Such spray coated phosphate ceramic
compositions produce high-strength, rapid-setting phosphate ceramic
coatings that provide corrosion protection and/or be used as an
undercoating in combination with a polymeric coating or paint, such
as an acrylic- or urethane-based coating or paint. In one aspect,
said phosphate spray coating compositions are suitable for spray
coating on metal surfaces, for example, structural elements and
chassis of transportation vehicles such as automobiles, trains,
cycles, aerospace vehicles, trucks, and buses.
[0060] In one aspect, the atomizable phosphate ceramic composition
can comprise an acidic phosphate component comprising an aqueous
solution, suspension, or slurry of an acid-phosphate, for example,
of chemical formula A.sub.m(H.sub.2PO.sub.4).sub.m.nH.sub.2O, where
A is hydrogen ion, ammonium cation, metal cation, or mixtures
thereof; where m=1-3, and n=0-6; the first component solution
adjusted to a pH of about 2 to about 5; a sparingly soluble basic
component, comprising, for example, an aqueous solution,
suspension, or slurry of an alkaline oxide or alkaline hydroxide
represented by B.sub.2mO.sub.m, B(OH).sub.2m, or mixtures thereof,
where B is an element of valency 2m (m=1, 1.5, or 2) the second
component solution adjusted to a pH of between 9-14; and optionally
a rheology modifier/suspending agent in an amount capable of
providing shear thinning of either the first component or the
second component and further capable of suspending a high solids
content of either the first component or the second component for
atomization. Optionally, pigments and/or aggregate material can be
present in an amount in at least one of the acidic phosphate and
the sparingly soluble basic component capable of imparting an
observable color and/or texture. The above atomizible spray coating
can provide a thin, paint-like coating for imparting hydrophobicity
and/or corrosion resistance to metallic surfaces. The rheology
modifier/suspending agent can be at least one of guar gum, diutan
gum, welan gum, and xanthan gum. By using a rheology
modifier/suspending agent in an amount capable of providing shear
thinning of either the acidic component or the sparingly soluble
basic component and further capable of suspending a high solids
content of either the acidic component or the sparingly soluble
basic component for atomization, excellent paint-like coatings for
imparting corrosion resistance to metallic surfaces are
obtained.
[0061] Examples of Group IV element with at least one carbon
covalent bond include silanes, siloxanes, polysilanes, and
polysiloxanes. (Poly)silanes and/or (p)olysiloxanes with reactive
end-groups, e.g. alkoxy, as self crosslinking anionic or cationic
emulsions or low molecular weight oligomers can be used, such as
POLON.TM. silicone or polysiloxane surfactants/sizings,
DYNASYLAN.TM. functionali zed silanes/siloxanes and poly- or
oligomeric functionalized siloxanes, and the like, in amounts of
about 0.1 weight percent to about 20 weight percent, or about 1
weight percent to about 10 weight percent.
[0062] In certain aspects of the present disclosure, the metallic
surface is that of a transition metal or its alloy, for example,
iron, chromium, aluminum, copper, etc. Processes and articles
prepared therefrom disclosed and described herein overcome many if
not all of the problems related to conventional passivation
processes of iron, steels, aluminum, and other corrodible metals.
The instant processes also provide a more economical,
environmentally-friendly method of coating steel and other metal
surfaces with acid-base inorganic phosphate based coatings that not
only passivate the layer but also provide abrasion resistance along
with good aesthetics in one step.
[0063] The metal phosphate ceramics, when used as a coating as
disclosed herein can comprise, in part, the formation of poly
phosphates, and in particular, poly phosphates formed by phosphites
at the interfacial regions of the substrate surface in the instant
passivation layer. Polyphosphate alone or in combination with the
organo-Group IV hydrophobic agent can provide impermeablity to
water and humidity, and, independently, can improve corrosion
resistance to the metallic surface. In one aspect, polyphosphates
in combination with metal silicates are present at the metallic
surface and/or interfacial regions of the metal substrate as
comprising the passivation layer and/or providing water resistance
or water proofing of the ceramic.
[0064] Acidic phosphate component - The acidic phosphate component
consists of an acid-phosphate representative of the formula,
A.sup.m(H.sub.2PO.sub.4).sub.m.nH.sub.2O, where A is an m-valent
element such as sodium (Na, m=1), potassium (K, m=1), magnesium
(Mg, m=2), calcium (Ca, m=2), aluminum (Al, m=3) etc. A may also be
a reduced oxide phase when higher-valent oxides are used. For
example, for iron, which exists in valence state of +2 and +3 (FeO
and Fe.sub.2O.sub.3 as oxides), A can be the metal of lower
oxidation state. It can also be a cation of oxides of four-valent
metal oxide such as ZrO.sup.2+, in which case m=2. nH.sub.2O in the
formula above is simply the bound water, where n can be any number,
normally ranging from 0 to 25.
[0065] It is possible to use hydro phosphates of trivalent metals
such as aluminum, iron and manganese represented by the formula
AH.sub.3(PO.sub.4).sub.2.nH.sub.2O, where A is a transition metal
that includes aluminum, iron, manganese, yttrium, scandium, and all
lanthanides such as lanthanum, cerium, etc.
[0066] In case the pH of the acidic precursor is higher than needed
for instant reaction, phosphoric acid may be added and the pH may
be adjusted to bring down the pH. A preferred pH selected is
between 3 and 4, and the most preferred pH is between 3 and 3.5.
either elevating the pH of phosphoric acid or that of an
acid-phosphate such as magnesium dihydrogen phosphate
(Mg(H.sub.2PO.sub.4).sub.2) or aluminum trihydrogen phosphate
(AlH.sub.3(PO.sub.4).sub.2) by neutralizing partially using an
alkaline oxide, hydroxide, or a mineral, or by acidifying a
dihydrogen phosphate such as mono potassium phosphate
(KH.sub.2PO.sub.4) that has a pH>3.5 by adding a small but
appropriate amount of phosphoric acid or a low pH acid phosphate
such as Mg(H.sub.2PO.sub.4).sub.2 or aluminum trihydrogen phosphate
AlH.sub.3(PO.sub.4).sub.2. Examples described later in this
document provide the art of adjusting this pH.
[0067] One or more of the components of the instant composition can
be wet milled to a size of about 25 to about 150 micron, about 50
to about 100 micron, or about 60 to about 80 micron in average
particle size to improve atomization and/or cure/set and/or
appearance qualities of the coating. In one aspect, the acidic
phosphate or basic precursor is wet-milled so that the average
particle size passes through 230 mesh sieve (less than 70
micron).
[0068] For oxychloride and oxysulfate compositions, the acidic
component consists of magnesium oxychloride, and magnesium
oxysulfates appropriately acidified with either hydrochloric acid
or sulfuric acid to reduce the pH.
[0069] Water may be added to the precursor component to reduce the
viscosity thereof, or other types of viscosity reducing agents
and/or rheology modifiers may be used. Commercial additives that
prevent algae growth may also added to this precursor so that no
algae growth occurs during storage of this precursor.
[0070] Sparingly soluble basic component includes, for example,
basic oxides, hydroxides and basic minerals. The sparingly soluble
basic component generally consists of a sparsely soluble oxide, or
preferably a hydroxide with a solubility product constant less than
the acid phosphate precursor. The oxide may be represented by the
formula B.sup.2mO.sub.m or B(OH).sub.2m, where B is a 2m-valent
metal. All divalent metal oxides (m=1), and some trivalent metal
oxides in reduced state fall into this category of small solubility
product constant oxides. Examples of divalent oxides are, but not
limited to, magnesium oxide, barium oxide, zinc oxide, calcium
oxide and copper oxide. Examples of trivalent oxides in reduced
state are iron oxide (FeO), and manganese oxide (MnO). In preferred
aspects of the instant disclosure, 0 to about 10 molar excess of
sparingly soluble basic component relative to acidic component is
used. For example, about 0.1-10 molar excess of Mg(OH).sub.2 based
on MKP acid phosphate can be used. In one aspect, the molar ratio
of acid:base components can be between about 0.9:1.0 to about
1.0:3.0; preferably about 1.0:2.0; and most preferably, about
1.0:1.8. For example, the composition comprising
Mg(OH).sub.2:KH.sub.2PO.sub.4=1.8:1.0 provides equal volumes of
Parts A and B during spraying. In other aspects, spray coatings of
the instant compositions having a molar ratio of about 1:2 or about
1:1.5 (acid:base components) with mixing, sprayed well and
corrosion-protected and/or water proofed effectively.
[0071] In one aspect, to achieve a desired setting rate and prevent
sagging of a coating prepared from the hydrophobic phosphate
ceramic disclosed herein, about 30-50 weight percent basic metal
oxide/hydroxide and about 55-75 weight percent acidic phosphate
component can be used. In one preferred aspect, about 40 weight
percent magnesium hydroxide and about 62 weight percent mono
potassium phosphate can be used. Other loadings may be used for
coating horizontal surfaces.
[0072] It has been observed that without a basic stabilizing agent,
such as K.sub.3PO.sub.4, or KOH, a basic metal oxide/hydroxide with
a mineral silicate (or Part B) is unstable. Surprisingly, the
particular basic stabilizing agent is not intuitive, for example,
K.sub.3PO.sub.4, or KOH is found effective in stabilizing a
solution of a basic metal oxide/hydroxide with a mineral silicate,
while NaOH does not provide as effective an amount of said
stabilization. Not to be held to any particular theory, it is
believed that potassium cation and/or phosphate anion contributes,
in part, to the stabilization of the basic metal oxide/hydroxide
and mineral silicate mixture. Thus, an effective amount of the
present basic stabilizing agent provides viscosity control of a
basic inorganic oxide/hydroxide with a mineral silicate or a Part
B, preventing or eliminating viscosity changes with time, for
example, a viscosity change that would render the a basic inorganic
oxide/hydroxide with a mineral silicate or Part B unusable for
spraying. In one aspect, the minimum loading of the basic
stabilizing agent is about 2 to about 15 weigh percent, 3 to about
10 weight percent (of the basic metal oxide/hydroxide and mineral
silicate, or Part B). More than 15 weight percent of basic
stabilization agent, for example, results in changes of set time
and further requires adjustment of the basic metal
oxide/hydroxide.
[0073] For reasons not entirely understood, when the acidic
component is phosphoric acid and the sparingly soluble basic
component is a metal oxide, e.g., iron oxide, in a stoichiometric
amount greater than 10% of the acidic phosphate component,
corrosion resistance is less than that when using the acidic
phosphate/sparingly soluble basic components herein disclosed, in
particular, sparingly soluble acid/base components. Thus, in one
aspect, improvement in corrosion protection is achieved when both
phosphoric acid as the inorganic acidic phosphate and iron oxide as
the metal oxide precursor are excluded.
[0074] In another aspect, the instant compositions, either as bulk
forms or as coatings can be formulated to provide aesthetic
properties, such as color, proper shine, and texture. This effect
may be achieved, for example, by adding pigments, color aggregate,
crushed glass, sand, etc, to the instant acidic phosphate/alkaline
metal oxide/hydroxide formulations with hydrophobic agent. For
example, the resulting coating comprising crushed glass prepared by
the processes disclosed herein provides a very dense, glassy
surface. Additional suitable ceramic pigments may be further added
to produce colored paints. Soluble glass in combination with the
instant compositions above can also be used in formulations for
coating of solid objects, to provide very dense, glassy solid
coatings having corrosion resistance.
Experimental Section
[0075] The following examples are illustrative of the embodiments
presently disclosed, and are not to be interpreted as limiting or
restrictive. All numbers expressing quantities of ingredients,
reaction conditions, and so forth used herein may be understood as
being modified in all instances by the term "about." Accordingly,
unless indicated to the contrary, the numerical parameters set
forth herein may be approximations that may vary depending upon the
desired properties sought to be obtained. At the very least, and
not as an attempt to limit the application of the doctrine of
equivalents to the scope of any claims in any application claiming
priority to the present application, each numerical parameter
should be construed in light of the number of significant digits
and ordinary rounding approaches. Several experimental examples,
listed below, were conducted in order to formulate, coat, and
demonstrate the attributes of the instant compositions disclosed
herein. pH values are provided using pH meters having +/-0.5
accuracy.
Hydrophobic Inorganic Phosphate Coating Compositions
[0076] A range of phosphate compositions may be used as the
corrosion inhibitor coatings commensurate with the spirit and scope
of that disclosed and described herein, the following exemplary,
non-limiting examples are provided:
TABLE-US-00001 TABLE 1 Exemplary Phosphate Ceramic Compositions
Part A Part B Sample Weight percent (%) of Part A Weight percent
(%) of Part B A mono potassium phosphate (MKP) magnesium hydroxide
(~38-39%) (~63-64%) wollastonite (~20-21%) phosphoric acid (~8%)
xanthan gum (0.07%) xanthan gum (0.15%) K.sub.3PO.sub.4 (~3.5%)
crystalline SiO.sub.2 (~1.5%) potassium methyl siliconate (40%
solids) remainder water (~9%) remainder water ~27-28% B Mono
Potassium Phosphate (MKP) = ~63-64% magnesium hydroxide (~38-39%)
(~63-64%) wollastonite (~20-21%) phosphoric acid (~8%) xanthan gum
(0.07%) xanthan gum (0.15%) K.sub.3PO.sub.4 (~3.5%) crystalline
SiO.sub.2 (~1.5%) potassium methyl siliconate (at 40% solids)
oligomeric short-chain alkylfunctional (~15%) siloxane oligomeric
or short-chain remainder water alkyl and/or phenyl siloxane with
hydrolysable alkoxy groups (~1.5%) remainder water C Mono Potassium
Phosphate (MKP) = ~63-64% magnesium hydroxide (~40%) (~63-64%)
wollastonite (~21%) phosphoric acid (~8%) xanthan gum (0.07%)
xanthan gum (0.15%) K.sub.3PO.sub.4 (~3.5%) crystalline SiO.sub.2
(~1.5%) potassium methyl siliconate (40% solids) remainder water
(~5%) remainder water D Mono Potassium Phosphate (MKP) = ~57%
magnesium hydroxide (~40%) (~63-64%) xanthan gum (0.07%) phosphoric
acid (~6%) K.sub.3PO.sub.4 (~3.5%) xanthan gum (0.15%)
self-crosslinking anionic siloxane emulsion crystalline SiO.sub.2
(~1%) (40% solids) (~5%) oligomeric short-chain alkylfunctional
remainder water siloxane oligomeric or short-chain alkyl and/or
phenyl siloxane with hydrolysable alkoxy groups (~1.5%) calcined
kaolin (~12%) remainder water F mono potassium phosphate (MKP)
magnesium hydroxide (~38-39%) (~63-64%) wollastonite (~20-21%)
phosphoric acid (~8%) xanthan gum (0.07%) xanthan gum (0.15%)
K.sub.3PO.sub.4 (~3.5%) crystalline SiO.sub.2 (~1.5%) remainder
water ~27-28% remainder water
[0077] The above samples were prepared with a slight molar excess
of Part B and represent a single exemplary embodiment. High
molecular weight (MW) polysiloxane with hydroxy or alkoxyl reactive
terminal groups was used at about 0.01 to about 10 weight percent
of the component (A or B). Oligomeric polysiloxane with hydroxy or
alkoxyl reactive groups was used at about 0.1 to about 20 weight
percent of the component (A or B). Organosiliconate salt was used
at about 0.01 to about 20 weight percent of the component (A or
B).
Water Uptake/Water Absorption Testing
[0078] For water absorption testing, an ASTM Cement substrate
(thickness=.about.0.5 inch) was used as Control. A comparative
example of a phosphate cement without the hydrophobic agent was
prepared and tested as a coating on the Control. Comparative sample
and test samples of compositions A-D were prepared of 15-20 mils (1
mil=1/1000 inches) thickness. Weight gain of the control and each
sample over the period of time (one day, 2 days, and 8 days) after
submerging in water. Weight gain was converted to weight per unit
area (kg/m.sup.2). Results are represented as permeability
(kg/m.sup.2).
[0079] Typically, a coating having a water permeability of about
0.3 kg /m.sup.2 or less over 24 hours is classified as water
impermeable. Samples absorbing water or gaining weight less than 1
kg/m.sup.2 are classified as hydrophobic (vapor permeable only).
There is another classification which classifies.
[0080] As shown in Table 2, Water permeability of the cement
control was greater than 5 kg/m.sup.2. In comparison, samples A-D
had water permeability of less than 1.0 kg/m.sup.2. Samples A-C had
water permeability of 0.2 kg/m.sup.2 or less. Thus, the presently
disclosed hydrophobic phosphate ceramic compositions provide water
and permeability and/or improved water permeability resistance.
TABLE-US-00002 TABLE 2 Water absorption results for exemplary
embodiments Water absorption (Kg/m.sup.2) Sample (~0.5 inch
thickness) (day 1; day 2; day 8) Cement-Control Standard ASTM 5.58;
5.62; 5.93 Cement Substrate A 0.18; 0.06; 0.09 B 0.11; 0.10; 0.08 C
0.20; 0.09; 0.06 D 0.54; 0.54; 0.91
Polarization Resistance Testing
[0081] Polarization resistance data was performed on metal test
samples coated with a magnesium potassium phosphate coating formed
by the combination and/or reaction of magnesium oxide (MgO) (or a
magnesium brine of magnesium hydroxide and magnesium salts in
water) with monoalkylsilicate salt, and mono potassium phosphate
(KH.sub.2PO.sub.4), which measures corrosion current of metal panel
in a 3 weight percent MgCl.sub.3 aqueous electrolyte solution of
about 6.5. Experimental data is converted to mil per year (mpy),
where mpy is the loss of metal (in thickness) due to corrosion per
year when exposed to the test condition. In this test, a poor
anti-corrosion coating initially shows very low number for
polarization resistance (as present in mpy) that increases
significantly overtime. Control samples provided about 1 mpy (mil
per year) that went down with time which may be the result of
formation of a thicker passivation layer. Samples coated with the
compositions of the present disclosure provided initial mpy values
of about 0.03 mpy that appeared to decrease to approach 0 or even
negative corrosion values. While not to be held to any particular
theory, the presently disclosed compositions appear to prevent the
electrolyte test solution from traversing the coating and reaching
the metal.
[0082] The results of testing of a number of samples is provided in
Table 3. As can be seen from Table 3, the present coatings and
monoliths prepared therefrom provided a basic environment of more
than pH 9, and greater pH (more basic) than conventional phosphate
ceramics/cements, even conventional phosphate ceramics/cements with
silicate fillers, said conventional phosphate ceramics/cements
prepared with an excess of acidic phosphate precursor or with equal
molar amounts of acid/base components. The environment can be
realized under ambient conditions of typical relative humidity or
humid conditions. Such environments are effective in reducing or
eliminating microbial growth and effective in at least partially
neutralizing or killing one or more microbes that are presented to
the surface of the present composition, whether as a coating or as
a monolithic form.
TABLE-US-00003 TABLE 3 pH of Samples and Controls Sample pH
Comments DI water 6.62 CONTROL - Molded Sample 6.70 Bulk sample was
immersed in the water Grancrete .COPYRGT. Sample and pH of water
measured after ~1 hr. Weight Ratio (2:2:2) of
(KH.sub.2PO.sub.4:MgO:Kaolin) CONTROL - Molded Sample 6.85 Bulk
sample was immersed in the water Grancrete .COPYRGT. Sample and pH
of water measured after ~1 hr. Weight Ratio (2:2:2) of
(KH.sub.2PO.sub.4:MgO:Wollastonite) CONTROL - Molded Ceramicrete
7.72 Bulk sample was immersed in the water (MgO/KH.sub.2PO.sub.4 +
Wollastonite) and pH of water measured after ~1 hr. (Weight ratio =
1:3:6) CONTROL - Molded Ceramicrete 7.9 Bulk sample was immersed in
the water (Fly ash based), weight ratio = and pH of water measured
after ~1 hr. MgO:KH.sub.2PO.sub.4:Fly ash = 1:3:6 Present
Disclosure Phosphate 9.78 Bulk sample was immersed in the water
Ceramic with molar excess of Part B and pH of water measured after
~1 hr. component (Molded product) Present Disclosure Phosphate 9.8
Bulk sample was immersed in the water Ceramic with molar excess of
Part B and pH of water measured after ~1 hr. component (aged around
2 years) Molded product Present Disclosure Phosphate 10.42 Sample
measured immediately Ceramic with molar excess of Part B component
(Aged around 3 years) (wall coating)
Antifungal/Antimicrobial Testing
[0083] The purpose of the testing was to evaluate the surface of a
treated sample and untreated sample for antimicrobial effectiveness
as demonstrated by the JIS Z 2801:2010 test method. Sample B and
Sample F from Table 1 were separately tested under JIS Z 2801. Each
sample was tested in triplicate. Test pieces were approximately 50
mm.times.50 mm.
[0084] Procedure: Inoculum was prepared using Staphylococcus aureus
ATCC #6538P, and Escherichia coli ATCC #8739, which were adjusted
with a spectrophotometer to a concentration of approximately
2.5-10.times.10.sup.8 Colony-Forming Units per milliliter (CFU/mL).
Dilute nutrient broth prepared as described in the test method was
used to further dilute the inoculum to 2.5-10.times.10.sup.5
CFU/mL. The untreated sample was tested in triplicate at Time=0 and
Time=24 hours to establish organism viability. The treated sample
was tested at Time=24 hours. Each sample piece was placed in
sterile container and then was inoculated with 0.4 mL of the
inoculum. The inoculum was then covered with 40 mm.sup.2 piece of
sterile plastic (cut from sterile Whirlpak.TM. bags) in order to
spread the inoculum evenly over the sample surface and hold it in
place.
[0085] The samples were incubated for 24 hours at 35.degree. C. and
a relative humidity of at least 90%. At the appropriate time, the
samples were placed into a sterile Whirlpak.TM. bag and 10.0 mL of
neutralizing broth was added to the bag. The test pieces were
thoroughly massaged in a bag containing the neutralizing broth
(SCDLP) to facilitate the release of the inoculum from the sample
surface into the neutralizing broth. Serial dilutions of the
neutralizing broth containing the inoculum were plated. All plates
were incubated at 35.degree. C. for 24-48 hours. After incubation,
bacterial colonies were counted and recorded.
[0086] Test Results are summarized in Table 3A below for S. Aureus
and Table 3B for E. coli. An untreated MSL plastic control
recovered an appropriate amount of organism at Time=0 and Time=24
to confirm organism viability. The number of viable bacteria in the
test inoculum was 1.3.times.10.sup.5 CFU/mL. This is the initial
number of bacteria placed onto to the sample surface for testing.
The value of the antimicrobial activity was calculated according to
the formula (I) listed below and recorded as log reduction.
R=(Ut-Uo)-(At-Uo)=Ut-At (I)
[0087] Where, R: antimicrobial activity; Uo: average of logarithm
numbers of viable bacteria from untreated sample at Time=0; Ut:
average of logarithm numbers of viable bacteria from untreated
sample at Time=24 h; and At: average of logarithm numbers of viable
bacteria from treated sample at Time=24 h.
TABLE-US-00004 TABLE 3A Staphylococcus aureus Inhibition Testing of
coatings disclosed herein Uo: Average of logarithm numbers of
viable 3.81 bacteria from untreated control at Time = 0 Ut: Average
of logarithm numbers of viable 6.14 bacteria from treated control
at Time = 24 h At: Average of logarithm numbers of viable 3.21
bacteria from Treated Sample F at Time = 24 h
[0088] According to the standard, an antibacterial product is
determined to have antibacterial effectiveness when the
antibacterial activity (R) is 2.0 or more. The sample coated with a
coating disclosed herein had an R value of 2.93, indicating
excellent antibacterial activity against Staph-type microbes.
TABLE-US-00005 TABLE 3B E. coli Inhibition Testing of coatings
disclosed herein Uo: Average of logarithm numbers of viable 3.93
baeteriafrom untreated control at Time = 0 Ut: Average of logarithm
numbers of viable 5.23 bacteria from treated control at Time = 24 h
At: Average .of logarithm numbers of viable 0.14 bacteria from
Sample B at Time = 24 h At: Average of logarithm numbers of viable
3.84 bacteria from Sample F .at Time = 24 h
[0089] With regard to Table 3B, according to the standard, an
antibacterial product is determined to have antibacterial
effectiveness when the antibacterial activity (R) is 2.0 or more.
The sample coated with Sample B (with Group IV-hydrocarbon covalent
bond component) disclosed herein had an R value of 5.09 (or a
99.9996% reduction), indicating excellent antibacterial activity
against E. coli, and was superior to similar phosphate ceramic
Sample F, which also had excellent antibacterial activity against
E. coli, having an R value of 1.39 (or a 95% reduction) without the
Group IV-hydrocarbon covalent bond component.
[0090] The purpose of this experiment was to evaluate the mold
resistance properties of the instant coating (Sample F; tested in
triplicate) as demonstrated by the ASTM D 3273 fungal resistance
test.
[0091] Procedure: The ASTM D 3273 test chamber contains soil that
was seeded with fungal spores of Aspergillus niger ATCC #6275,
Penicillium citrinum ATCC #9849, and Aureobasdium pullulans ATCC
#9348 and allowed to grow. The D 3273 chamber was maintained at
32.5.+-.1.degree. C. with a relative humidity between 95.+-.3%. The
test samples were hung in the D 3273 chamber with three pieces of
untreated generic wallboard (controls) to confirm validity of the
fungal inoculum coming from the soil. Samples were examined weekly
for fungal growth and defacement and rated according to visual
defacement of fungal growth. Temperature and relative humidity
equipment is internally validated to NIST traceable standards using
an externally calibrated Vaisala MI70/HMP75B, Serial
#G4730008/G4930004; A2LA accredited ISO 17025 Cert. #2083.01.
[0092] Test Results: After 4 weeks of incubation in the D 3273
chamber, the results for the test pieces can be found in Table 4
below. The control pieces performed as expected, confirming the
validity of the test. Samples are rated according to degree of
surface defacement. Visual defacement is determined with an unaided
eye, using magnification only to confirm suspicious areas. The
rating scale is as follows:
TABLE-US-00006 TABLE 4 Aspergillus niger ATCC# 6275, Penicillium
citrinum ATCC# 9849, and Aureobasdium pullulans inhibition using a
coating disclosed and described herein. Rating Definition 10 No
Defacement 9 90% clear (1-10% defaced) 8 80% clear (11-20% defaced)
7 70% clear (21-30% defaced) 6 60% clear (31-40% defaced) 5 50%
clear (41-50% defaced) 4 40% clear (51-60% defaced) 3 30% clear
(61-70% defaced) 2 20% clear (71-80% defaced) 1 10% clear (81-90%
defaced) 0 0% clear (91-100% defaced) Sample Description Week 1
Week 2 Week 3 Week 4 Front Front Front Front SAMPLE 1-1 10 10 10 10
1-2 10 10 10 10 1-3 10 10 10 10 Controls and Conditions Untreated
Wallboard 9/9 3/3 1/2 0/2 Untreated Wallboard 9/9 3/3 1/3 0/3
Untreated Wallboard 8/9 4/4 1/2 1/2 Temperature .degree. C. (32.5
.+-. 1.degree. C.) 31.7 31.8 31.7 31.9 Relative Humidity (95 .+-.
3%) 95.2 94.9 95.0 94.8
[0093] Discoloration was observed on all three replicates during
week 2 evaluation. Areas in red were observed, but are not fungal
growth but rather discoloration from a clip used to suspend the
samples in the chamber. Also observed on the samples were small
specked areas that are also discoloration that appeared to be
rust.
[0094] Based on the above, the coatings disclosed herein are
effective in inhibiting and preventing E. coli and other
hospital-related bacteria and are superior to phosphate
compositions without the Group IV-carbon covalent bond
component.
* * * * *