U.S. patent application number 13/345200 was filed with the patent office on 2012-10-04 for concrete coloring compositions and methods.
Invention is credited to Ed Daraskevich, Kevin W. Evanson, Matthew S. Gebhard, Sanford Lee Hertz, T. Haward Killilea, Jason J. Netherton, William Tao.
Application Number | 20120247372 13/345200 |
Document ID | / |
Family ID | 42153139 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120247372 |
Kind Code |
A1 |
Hertz; Sanford Lee ; et
al. |
October 4, 2012 |
CONCRETE COLORING COMPOSITIONS AND METHODS
Abstract
The present invention provides acidic compositions and methods
that are adapted to impart color to cementitious or mineral
substrate surfaces. Specifically, the present invention relates to
acidic compositions and methods adapted to treat cementitious or
mineral substrate surfaces that have the advantage of using a less
corrosive acid-based solution. The acidic composition incorporates
species including a weak base in equilibrium with a conjugate acid.
The presence of such species moderates the corrosive behavior of
the acid while still allowing excellent coloring action to
occur.
Inventors: |
Hertz; Sanford Lee; (Hoffman
Estates, IL) ; Daraskevich; Ed; (Oswego, IL) ;
Tao; William; (Downers Grove, IL) ; Netherton; Jason
J.; (Kenosha, WI) ; Gebhard; Matthew S.;
(Cary, IL) ; Killilea; T. Haward; (North Oaks,
MN) ; Evanson; Kevin W.; (Maple Grove, MN) |
Family ID: |
42153139 |
Appl. No.: |
13/345200 |
Filed: |
January 6, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12291316 |
Nov 7, 2008 |
8092555 |
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13345200 |
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11746657 |
May 10, 2007 |
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12291316 |
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Current U.S.
Class: |
106/808 ; 8/495;
8/523 |
Current CPC
Class: |
C04B 41/5012 20130101;
C04B 41/52 20130101; C04B 41/009 20130101; C04B 2111/82 20130101;
C04B 41/52 20130101; C04B 41/5012 20130101; C04B 41/52 20130101;
C04B 41/71 20130101; C04B 2103/0094 20130101; C04B 2103/50
20130101; C04B 2103/50 20130101; C04B 20/0048 20130101; C04B
41/4535 20130101; C04B 41/4535 20130101; C04B 41/5012 20130101;
C04B 41/0045 20130101; C04B 41/4842 20130101; C04B 2103/0094
20130101; C04B 41/483 20130101; C04B 28/02 20130101; C04B 41/522
20130101; C04B 41/52 20130101; C04B 41/65 20130101; C04B 41/009
20130101 |
Class at
Publication: |
106/808 ; 8/495;
8/523 |
International
Class: |
D06P 3/80 20060101
D06P003/80; C04B 16/00 20060101 C04B016/00 |
Claims
1.-24. (canceled)
25. A method, comprising: (a) obtaining a composition derived from
ingredients including (i) at least one metal salt that is a Lewis
acid and that imparts a color to a surface of a cementitious or
mineral substrate when the composition is in contact with and
reacts with the surface; (ii) a weak base, wherein the conjugate
acid of the weak base has a pKa less than 7 and greater than the
pKa of the first acid; (b) wetting the surface with the
composition; and (c) permitting the composition to react with the
substrate surface and develop color.
26. The method of claim 25, wherein the substrate comprises a fiber
cement building product.
27. The method of claim 25, wherein the metal salt comprises a
FeCl.sub.2 salt.
28. The method of claim 25, wherein in the metal salt comprises a
CuCl.sub.2 salt.
29. The method of claim 25, wherein the weak base can decompose
upon application to the substrate into one or more components that
comprise another base.
30. The method of claim 25, wherein the weak base can decompose
upon application to the substrate into one or more components that
have a vapor pressure greater than 0.01 psi at 25.degree. C.
31. The method of claim 25, wherein the ingredients further
comprise a MnCl.sub.2 salt.
32. The method of claim 25, wherein in the weak base comprises
urea.
33. The method of claim 25, wherein the one or more metal salts
comprise at least one of a chloride, sulfate, nitrate, nitrite,
phosphate, or phosphonate salt of titanium, vanadium, chromium,
manganese, iron, cobalt, nickel, copper, aluminum, magnesium, or
barium.
34. The method of claim 25, wherein the composition further
comprises a metal ion complexing agent.
35. The method of claim 25, further comprising the step of
neutralizing the colored surface.
36. The method of claim 25, further comprising the step of:
applying an at least partially transparent protective coating over
at least a portion of the colored surface.
37. The method of claim 25, further comprising the step of:
applying a hydrophobic resist to the surface prior to application
of the composition.
38. A stained cementitious or mineral substrate prepared according
to the method of claim 25.
39. A stained cementitious or mineral substrate prepared according
to the method of claim 26.
40. A system, comprising: (a) a cementitious surface; and (b) an
aqueous composition in contact with the surface so that the
composition can react with the surface and develop color, the
composition derived from ingredients comprising (1) at least one
metal salt that is a Lewis acid and that imparts a color to a
surface of a cementitious or mineral substrate when the composition
is in contact with and reacts with the surface; (ii) a weak base,
wherein the conjugate acid of the weak base has a pKa less than 7
and greater than the pKa of the first acid.
Description
PRIORITY CLAIM
[0001] The present non-provisional patent Application is a
continuation of U.S. patent application having Ser. No. 12/291,316,
filed Nov. 7, 2008, by an inventorship including Sanford Lee Hertz
and titled CONCRETE COLORING COMPOSITIONS AND METHODS, which is a
continuation-in-part and claims priority under 35 USC .sctn.120
from U.S. patent application having Ser. No. 11/746,657, filed on
May 10, 2007, by an inventorship including Sanford Lee Hertz, and
titled WEAK ACID BASED CONCRETE STAIN, both of which applications
are incorporated by reference herein in their entireties and for
all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates generally to compositions and
methods that are adapted to impart color to cementitious or mineral
substrate surfaces.
BACKGROUND
[0003] Cement-based compositions enjoy broad application in
construction materials (e.g., cementation siding and trim products
such as fibercement products), tile setting, wall and pool
plasters, stucco, self leveling compounds, roofing tiles and cement
patches. Concrete and like materials are produced from the alkaline
earth metals typically by mixing Portland cement with sand, gravel,
fibers, and water. The reaction of the cement with the water
produces among other things metal carbonates such as calcium
carbonate. The calcium carbonate in the mixture is insoluble in
water but reacts readily with most acids.
[0004] There has been a desire for some time to produce colored
concrete to improve the decorative appearance of the concrete or
cement-based compositions. For example, U.S. Pat. No. 3,930,740
discloses tools for imprinting non-repeating stone patterns in
fresh concrete to which color is added. U.S. Pat. No. 5,735,094
discloses a process for applying an ornamental coating comprised of
liquid mortar that includes a color pigment. The addition of dyes
and pigments to the cementitious materials has also enjoyed wide
application in all of the above-mentioned materials.
[0005] There are several processes for coloring or ornamenting a
concrete surface that are known in the art. These include sweeping
partially set concrete to produce a broom surface or adding a
coloring agent that is mixed into the concrete blend. However,
afterwards, a thorough clean-up of the applicator equipment is
necessary, resulting in considerable labor and expense. This method
is costly and inefficient, as coloring agents are expensive, become
mixed throughout the concrete, and are only needed at the surface
where they are visible. More elaborate surface treatments are
known, including embedding stones varying in size or color into
concrete areas by means of cement or resin.
[0006] One of the more common processes known in the art for
coloring or staining concrete involves washing a concrete surface
with an acidic solution containing a metallic salt (also referred
to herein as a "metal salt"). This contact helps cause the surface
to develop color. After application of the acidic staining solution
and development of the color, a neutralizing agent is commonly
applied to the stained concrete, and a clear protection polymeric
sealer coating is applied. The clear top coat helps to further
realize the color development.
[0007] A second common method in the art of coloring concrete
involves washing the concrete surface with an acidic solution to
roughen or etch the surface; using a mixture of common baking soda
and water to neutralize and rinse away the etching solution; and
coloring the surface with a polymer based stain or paint; and
finishing the surface with a clear coating.
[0008] Another known process involves acid etching with a mineral
acid such as hydrochloric acid or diamond grinding a concrete
surface, followed by application of cementitious overlay. This
process is described in Bob Harris' Guide to Concrete Overlays
& Toppings (Decorative Concrete Institute 251 Villa Rosa Road
Temple, Ga. 30179). After the cementitious overlay has
appropriately set, it can be stained with an acidic solution
containing a metallic salt. These staining techniques, which employ
an acidic solution containing a metallic salt, are desirable
because they offer highly durable light fast coloration of the
concrete. Typically these processes involve the use of highly
corrosive acidic solutions, which are dangerous to handle. Many
other desirable techniques for staining concrete are described in
Bob Harris' Guide to Stained Concrete Interior Floors (Decorative
Concrete Institute 251 Villa Rosa Road Temple, Ga. 30179).
SUMMARY OF THE INVENTION
[0009] The inventors have discovered that incorporating a weak base
into acid-based coloring compositions also including suitable metal
salt(s) can moderate the corrosive characteristics of the acid
while still allowing effective coloring to occur. In representative
embodiments, the base is in equilibrium in aqueous media with a
conjugate acid to moderate the corrosive characteristics of the
acid. The incorporation of a weak base into acidic coloring
compositions provides an effective and safer means to stain
cementitious substrates. Although the compositions can be derived
from separate ingredients comprising the desired acid and weak
base, the compositions are easier to manufacture from easily and
safely handled ingredients, such as salts of a protonated form of
the weak base. Acidic and basic characteristics then form in situ
when such a salt is dissolved in an aqueous medium. For example, a
representative embodiment of a salt of a protonated weak base is
urea monohydrochloride, which is a commercially available, stable
solid. When dissolved in water, an acidic solution results that
also comprises aqueous species in equilibrium derived from the
urea.
[0010] In contrast, traditional concrete acid stains use an acid
such as hydrochloric acid to decompose the calcium carbonate and
calcium oxide in the concrete and to facilitate the ion exchange
with the metallic salt, but this is done without the presence of
effective amounts of any weak base or conjugates thereof. While the
acid and metallic salts alone do impart color to the surface of the
material, the use of only acid and metallic salt without the
moderating effects of a base tends to involve the production of
excessive fumes of hydrogen chloride. In addition, the conventional
hydrochloric acid solution is very corrosive and thus dangerous to
prepare, handle, and use.
[0011] An additional advantage of combining an acid with a weak
base is that the stained concrete self-neutralizes during the
staining process. This eliminates the need to go through a
neutralization step before rinsing, although neutralizing steps can
still be practiced if desired. In contrast, typically, conventional
acid stains must be rinsed after application to remove excessive
salt precipitate. Conventional acid stains that use hydrochloric
acid must be neutralized prior to rinsing, or the runoff from the
rinse can stain adjacent concrete. Typical neutralizing agents used
are ammonia or sodium hydroxide, or baking soda solutions.
[0012] The compositions of the present invention also can be used
in any of the staining methods described in Bob Harris' Guide to
Stained Concrete Interior Floors (Decorative Concrete Institute 251
Villa Rosa Road Temple, Ga. 30179.
[0013] In one aspect, the present invention relates to a method,
comprising the step of applying to the surface of a cementitious or
mineral substrate a composition including (i) an acid which has a
pKa less than 6; (ii) a weak base, wherein the conjugate acid of
the weak base has a pKa less than 7 and greater than the pKa of the
acid; and (iii) one or more metal salts capable of imparting a
color when the composition is applied to a cementitious or mineral
substrate. The treatment may be used to alter the color of the
surface. After treatment, a protective top coating optionally can
be applied to the treated surface. Such top coatings not only help
protect the surface, but they also can help further develop the
color of the surface. The method is particularly useful for
treating fibercement building products. In another aspect, the
present invention relates to stained substrates, including but not
limited to fibercement building products, prepared according to
these methods.
[0014] In another aspect, the present invention relates to a
method, comprising the steps of applying to at least a portion of
the surface of a fiber cement substrate a composition comprising a
reaction mixture of (i) an acid which has a pKa less than 6; (ii) a
weak base, wherein the conjugate acid of the weak base has a pKa
less than 7 and greater than the pKa of the acid; and (iii) one or
more metal salts capable of imparting a color when the composition
is applied to a fiber cement substrate; and applying a protective
coating to cover the fiber cement surface.
[0015] In another aspect, the present invention relates to a
method, comprising the steps of: (a) incorporating a salt of a
protonated base into an aqueous liquid carrier, said protonated
base having a pKa of less than about 7; (b) incorporating a salt of
a transition metal into the aqueous liquid carrier; and (c) causing
the composition to contact the cementitious surface.
[0016] In another aspect, the present invention relates to a
system, comprising: (a) a cementitious surface; and (h) an aqueous
composition in contact with the surface, said composition
comprising (i) aqueous species comprising a weak base in
equilibrium with a conjugate acid of the weak base, said conjugate
acid of the weak base having a pKa of less than about 7; and (ii)
aqueous species comprising a transition metal ion and a
corresponding anion, wherein the salt corresponding to the
transition metal ion and the anion is a Lewis acid.
[0017] In another aspect, the present invention relates to a
method, comprising the steps of applying to at least a portion of
the surface of a fiber cement substrate an acidic composition
comprising a reaction mixture of (i) an acid which has a pKa less
than 6; and (ii) one or more metal salts capable of imparting a
color when the composition is applied to a fiber cement substrate;
and applying a radiation cured protective coating to cover the
fiber cement surface.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The current invention relates to compositions (e.g.,
solutions and dispersions) and methods for imparting color to a
cementitious or mineral substrate using these compositions.
Preferably, the compositions are aqueous, but may optionally
include one or more other liquid carriers. As used herein, a
"cementitious substrate" is meant to include traditional cement
substrates as well as any composites incorporating cementitious and
other ingredients. Cement generally is an inorganic binder that
cures in the presence of aqueous media. Examples of cements include
portland cement, non-portland cement, and blends derived from
these. Examples of portland cement and blends thereof include
blastfurnace cement, flyash cement, Pozzolan cement, silica fume
cement, masonry cement, expansive cement, colored cement, and the
like. Non-portland cements include Plaster of Paris, pozzolan lime
cement, slag-lime cement, supersulfated cement, calcium aluminate
cement, calcium sulfoaluminate cement, natural cement, and
geopolymer cement. According to one categorization, cements can be
hydraulic or non-hydraulic. Cements are used to produce concrete,
mortar, tile, building materials such as siding products, bricks,
synthetic stones roads, walkways, furniture, vessels, fluid
conduits, and the like. Thus, a cementitious material includes
includes the composite known as fibercement. Fibercement is a
composite that is used widely to produce building materials,
particularly siding used to cover the exteriors of commercial,
residential, farming, or other structures. Fibercement generally is
a composite that incorporates a cement binder and one or more
organic or inorganic fibers. Cellulose fibers are commonly used in
fibercement. Fibercement may also include one or more other
ingredients commonly added to cement products including sand,
vermiculite, perlite, clay, and/or the like.
[0019] Consequently, a "cementitious substrate" would specifically
include fibercement building products, for example, several
preferred fiber cement siding products are available from James
Hardie Building Products Inc. of Mission Viejo, Calif., including
those sold as HARDIEHOME.TM. siding, HARDIPANEL.TM. vertical
siding, HARDIPLANK.TM. lap siding, HARDIESOFFIT.TM. panels,
HARDITRIM.TM. planks and HARDISHINGLE.TM. siding. Other suitable
fiber cement siding substrates include AQUAPANEL.TM. cement board
products from Knauf USG Systems GmbH & Co. KG of Iserlohn,
Germany, CEMPLANK.TM., CEMPANEL.TM. and CEMTRIM.TM. cement board
products from Cemplank of Mission Viejo, Calif.; WEATHERBOARDS.TM.
cement board products from CertainTeed Corporation of Valley Forge,
Pa.; MAXITILE.TM., MAXISHAKE.TM. AND MAXISLATE.TM. cement board
products from MaxiTile Inc. of Carson, Calif.; BRESTONE.TM.,
CINDERSTONE.TM., LEDGESTONE.TM., NEWPORT BRICK.TM., SIERRA
PREMIUM.TM. and VINTAGE BRICK.TM. cement board products from
Nichiha U.S.A., Inc. of Norcross, Ga., EVERNICE.TM. cement board
products from Zhangjiagang Evemice Building Materials Co., Ltd. of
China and E BOARD.TM. cement board products from Everest Industries
Ltd. of India.
[0020] The compositions desirably are acidic and incorporate
aqueous species of a weak base in equilibrium with a conjugate acid
and one or more aqueous species of one or more metal salts. Such
metal salts may be Lewis acids in some embodiments. As used herein,
a weak base refers to a base whose conjugate acid has a pKa of less
than about 7, preferably in the range from about -1 to about 7,
more preferably about -1 to about 5, most preferably about -1 to
about 3. Desirably, the compositions are acidic and may include
aqueous species corresponding to an acid with a pKa of less than 6,
aqueous species corresponding to a weak base such that the
conjugate acid of the weak base has a pKa of less than 7 and
greater than the pKa of the acid, and one or more water soluble
metal salts. In various embodiments, the water-soluble metal salts
of the composition can include salts of the transition elements. In
some embodiments, the weak base can decompose when it is applied to
the cementitious materials such that the decomposition products are
also bases. For instance, without wishing to be bound by theory, it
is believed that aqueous urea species can decompose to form
products including ammonia.
[0021] The strength of a base is defined by the pKa of a conjugate
acid. The higher the pKa of the base's conjugate acid the stronger
the base. For example acetate is a weak base where the conjugate
acid (acetic acid) has a pKa of 4.75. Lactate is a weak base where
the conjugate acid (lactic acid) has a pKa of 3.86. Given this
definition, acetate would be considered a stronger base than
lactate. Certain embodiments will include a weak base that can
decompose into one or more components that have a vapor pressure
greater than 0.01psi at 25.degree. C. upon application to
substrate. For instance, without wishing to be bound, it is
believed that aqueous urea species can decompose to ammonia and
carbon dioxide as well as water. In some embodiments, the aqueous
acid corresponds to a hydrogen halide such as HCl. In yet others,
the weak base preferably comprises aqueous urea species.
[0022] Weak bases useful in the present invention include: [0023]
1) substituted ureas of the following formula
[0023] R.sub.1R.sub.2--N--C(O)--N--R.sub.3R.sub.4 [0024] where
R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are C1-C10 carbon groups or
hydrogen, including for example urea, tetramethyl urea, acetylurea,
imidazolidinone, or substituted imidazolidones, pyrimidinone,
pyrimidinedione, and the like; [0025] 2) amides such as formamide,
and dimethyl formamide, or acetamides such as dimethyl acetamide,
caprolactam; and, pyrollidone; [0026] 3) esters of carbonic acid
such as alkyl and aryl carbonates, such as dimethyl carbonate,
propylene carbonate, ethylene glycol his methyl carbonate, ethyl
M-tolyl carbonate; [0027] 4) carbamates such as alkyl and aryl
carbamates, such as ethyl ethylcarbamate, oxazolidinone, and
oxazolidinedione; and, [0028] 5) amino acids such as glycine,
alanine, leucine, valine, phenylalanine, aspartic acid, glutamic
acid, cysteine, lysine, and histidine.
[0029] Additional examples of weak bases include alkanolamines,
including triethanolamine, diethanolamine, monoethanolamine and
alkoxylated amines of the following formula
(HO--[(R)O]--R).sub.x--R).sub.y--NH.sub.3-y, wherein each R
independently is a C2 to C8 alkyl group, and x can vary from 1 to
100, and y can vary from can vary from 1 to 3; polymers with
nitrogen-containing heterocyclic groups (including but not limited
to pyridine, pyrimidine, imidazole, tetrazole, pyrazine, quinoline,
isoquinoline, indole, isoindole, benzimidazole, purine, pyrrole,
isopyrazole, quinazoline, pyridazine, pyrazine, cinnoline,
phthalazine, quinoxaline, xanthine, hypoxanthine, and pteridine);
polymers and copolymers of acrylamide, and cyclic amides such as
caprolactam; pyrollidone, polyvinyl pyrollidone, copolymers of
vinyl pyrollidone, methacrylamide, polymethacrylamide, copolymers
of methacrylamide, ammonia, guanidine, hydroxyurea, semicarbazide;
mono-, di-, or tri(alkyl or aryl)urea, and wherein in the case of
di(alkyl or aryl)urea the alkyl or aryl groups can be on the same
or different nitrogen atoms, O-methyl hydroxyl amine
(methoxylamine), aniline, and hydrazine. Preferred bases are
nitrogenous bases. Preferred are substituted ureas. Most preferred
is urea.
[0030] In preferred embodiments, the amount of weak base utilized
may be determined by stoichiometric balance with the acid
equivalents. The molar equivalents of acid may be determined from
the total number of protons per mole of acid that can be ionized at
pH values below pH 9.0. For example, (i) hydrochloric acid has one
ionizable proton per mole of hydrochloric acid; (ii) sulfuric acid
has two ionizable protons per mole of sulfuric acid; and (iii)
phosphoric acid only has two ionizable protons per mole of
phosphoric acid, and one proton which can be ionized at pH values
above 9.0. Preferred compositions include at least 5%, more
preferably at least 10%, and more preferably at least 50% molar
equivalents of weak base based on the total molar equivalents of
acid. Preferred compositions include less than 200%, more
preferably less than 175%, and more preferably less than 150% molar
equivalents of weak base based on the total molar equivalents of
acid.
[0031] In some embodiments, the equivalents of acid can be derived
from multiple sources. For instance, if the solution is derived
from a first acid source and a metal salt that is also a Lewis
acid, both the first acid source and the metal salt contribute acid
equivalents to the composition. An illustrative embodiment of such
a coloring composition of the invention could be derived from
ingredients including urea monohydrochloride, which can be viewed
as a first acid source, and a coloring salt that is a Lewis acid
such as FeCl.sub.2. It is believed that the urea monohydrochloride
contributes one mole of hydrogen ions and one mole of chloride ions
per mole of added urea monhydrochloride, and the ferrous chloride
adds two moles of hydrogen ions and two moles of chloride ions per
mole of added ferrous chloride. Thus, both of these ingredients
will contribute acid equivalents corresponding to aqueous HCl when
dissolved in water.
[0032] Acids useful in the present invention can include carboxylic
acids such as acetic, maleic, citric, formic, and benzoic;
phosphoric; phosphonic such as ethyl phosphonic acid;
polyphosphoric acids such as pyrophosphoric, and hexameta
phosphoric; sulfuric; sulfonic such as benzyl sulfonic acid; nitric
or nitrous acid; hydrogen halides such as hydrogen fluoride,
hydrogen chloride, hydrogen bromide, and hydrogen iodide. Preferred
are phosphoric and polyphosphoric acids, nitric or nitrous acid,
and hydrogen chloride. More preferred are phosphoric,
pyrophosphoric, and hydrogen chloride. Most preferred is hydrogen
chloride.
[0033] Preferred compositions include a sufficient amount of acid
such that the pH of the resultant composition is less than about 6,
preferably less than about 4, more preferably less than about 2,
and most preferably less than about 1. In such compositions, the pH
preferably is greater than about -2, more preferably greater than
about -1. In many representative compositions, this corresponds to
compositions that include at least 0.25%, more preferably at least
0.5%, and most preferably at least 1% acid by weight based on the
total weight of the composition. Preferred compositions include
less than 20%, more preferably less than 15%, and most preferably
less than 10% acid by weight based on the total weight of the
composition. Suitable acids preferably have a pKa of less than 6,
more preferably less than 5, most preferably less than 3, and
optimally less than 1.
[0034] In many embodiments, the desired acid(s) may be added to the
compositions directly to provide the desired acidic pH
characteristics. Alternatively, nonacidic ingredients, such as
salts of a protonated base that form acidic species in situ, can
also be used.
[0035] Preferred compositions contain metal ions, which are
typically introduced as water soluble or acid soluble metal salts.
Metal salts useful in the various compositions of the invention can
include chloride, sulfate, nitrate, nitrite, phosphate, or
phosphonate salts of titanium, vanadium, chromium, manganese, iron,
cobalt, nickel, copper, aluminum, magnesium, or barium. Specific
examples of suitable metal salts include but are not limited to
VCl.sub.3, Cr(CH.sub.3CO.sub.2).sub.3, Cr(CH.sub.3CO.sub.2).sub.2,
CrCl.sub.3, CrCl.sub.2, Cr.sub.2(SO.sub.4).sub.3, Cr(SO.sub.4),
Cr(NO.sub.3).sub.3, CrPO.sub.4, MnCl.sub.2,
Mn.sub.2(PO.sub.4).sub.3, MnSO.sub.4, Mn(NO.sub.3).sub.2,
MnCO.sub.3, FeCl.sub.2, FeCl.sub.3, FeSO.sub.4,
Fe.sub.2(SO.sub.4).sub.3, FePO.sub.4, Fe(H.sub.2NSO.sub.3).sub.2,
Fe(NO.sub.3).sub.3, Fe(C.sub.2O.sub.4), CoCl.sub.2, CoCl.sub.3,
CoSO.sub.4, Co(NO.sub.3).sub.2, CuCl, CBrl.sub.2, CuCl.sub.2,
Cu(CH.sub.3CO.sub.2).sub.2, Cu(HCO.sub.2).sub.2,
Cu(C.sub.2O.sub.4), CuCO.sub.3, CuSO.sub.4, Cu(NO.sub.3).sub.2,
NiCl.sub.2, and NiCl.sub.3. Preferred metal salts include salts of
Fe, Cr, Mn, Cu, and Co.
[0036] The unit of measurement for the metal salt is weight percent
of metal ions based on total composition weight. For example if 10
grams of anhydrous ferrous chloride (FeCl.sub.2) is added to 90
grams of water then the resulting composition contains 4.41% of
iron (Fe(II)) ion. Suitable compositions can include more than one
type of metal ion such as for example iron and copper ions.
Preferred compositions include at least 0.1%, more preferably at
least 0.2%, and most preferably at least 0.5% by weight of total
metal ion based on total composition weight. Preferred compositions
include less than 25%, more preferably less than 20%, and most
preferably less than 15% by weight of total metal ion based on
total composition weight.
[0037] The compositions of the present invention can further
comprise one or more optional additives. One optional additive is a
metal ion complexing agent that can help facilitate reaction with
the substrate and/or modulate solubility of composition
ingredients. Examples of complexing agents include EDTA; amino
phosphonates, such as those sold under the trade name Dequest.TM.;
phosphates; and polyphosphates. Other optional additives include
surfactants, defoamers, dispersants, or organic solvents (including
additives capable of improving the wetting of the composition).
Mixtures of these optional additives may also be used.
[0038] In addition to water, aqueous embodiments of the coloring
compositions may include one or more optional solvents. Suitable
optional solvents include: water miscible solvents such as
methanol, ethanol, isopropanol, n-propanol, acetone, ethylene
glycol alkyl ethers, propylene glycol alkyl ethers and diacetone
alcohol; and water immiscible solvents such as alkyl acetates,
butyl acetate, methyl isoamyl ketone, amyl acetate, diisobutyl
ketone, xylene, toluene, butanol, and mineral spirits. Suitable
optional defoamers include: silicone, petroleum, mineral, natural
oil, or polymeric defoamers, and mixtures of these defoamers. When
used, the amount of defoamer is preferably between 0.005% and 5%,
more preferably between 0.01% and 4%, and more preferably is
between 0.05% and 3% by weight based on total composition
weight.
[0039] Typical surfactants can include anionic and nonionic
surfactants. When used, the amount of surfactant is preferably
between 0.05% and 5%, more preferably between 0.1% and 4%, and more
preferably is between 0.2% and 3% by weight based on total
composition weight. Suitable anionic surfactants include, for
example, the higher fatty alcohol sulfates, such as sodium lauryl
sulfate; alkylaryl sulfonates such as sodium or potassium
isopropylbenzene sulfonates or isopropyl naphthalene sulfonates;
alkali metal higher alkyl sulfosuccinates, such as sodium octyl
sulfosuccinate, sodium N-methyl-N-palmitoylaurate, sodium oleyl
isothionate; alkali metal salts and ammonium salts of
alkylarylpolyethoxyethanol sulfates, sulfonates, or phosphates,
such as sodium tert-octylphenoxypolyethoxyethyl sulfate having 1 to
50 oxyethylene units; alkali metal salts and ammonium salts of
alkyl polyethoxyethanol sulfates, sulfonates, and phosphates; and
alkali metal salts and ammonium salts of aryl polyethoxyethanol
sulfates, sulfonates, and phosphates.
[0040] Suitable nonionic surfactants include
alkylphenoxypolyethoxyethanols having alkyl groups of from about 7
to 18 carbon atoms and from about 6 to about 60 oxyethylene units,
such as heptylphenoxypolyethoxyethanols, methyloctyl
phenoxypolyethoxyethanols; polyethoxyethanol derivatives of
methylene-linked alkyl phenols; sulfur-containing agents such as
those made by condensing from about 6 to 60 moles of ethylene oxide
with nonyl mercaptan, dodecyl mercaptan, or with alkylthio-phenols
wherein the alkyl groups contain from 6 to 16 carbon atoms;
ethylene oxide derivatives of long chained carboxylic acids, such
as lauric acid, myristic acid, palmitic acid, oleic acid, or
mixtures of acids such as those found in tall oil containing from 6
to 60 oxyethylene units per molecule; analogous ethylene oxide
condensates of long chained alcohols such as octyl, decyl, lauryl,
or cetyl alcohols, ethylene oxide derivatives of etherified or
esterified polyhydroxy compounds having a hydrophobic hydrocarbon
chain, such as sorbitan monostearate containing from 6 to 60
oxyethylene units; block copolymers of ethylene oxide section
combined with one or more hydrophobic propylene oxide sections.
[0041] Typical dispersants can include polymers and copolymers of
ethylenically unsaturated carboxylic acids such as (meth)acrylic
acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride,
and monoesters of fumaric acid; phosphorus acid monomers such as
phosphoethyl (meth)acrylate and allyl phosphonic acid; and sulfur
acid monomers such as 2-acrylamido-2-methyl-1-propanesulfonic acid,
sulfoethyl (meth)acrylate, and vinyl sulfonic acid. This would
include dispersants marketed under the trade name Tamol.TM.. Citric
acid, oxalic acid, phosphoric acid, pyrophosphoric acid, and poly
phosphoric acids may also be employed.
[0042] The current invention also provides methods for staining the
surface of a cementitious or mineral substrate comprising applying
any of the compositions described herein to the surface of a
cementitious or mineral substrate. The methods can be done in a
single operation comprising: [0043] completely wetting the surface
with an excess of the stain composition (e.g., solution or
dispersion), [0044] permitting the composition to react with the
substrate and develop color, [0045] permitting the stain to dry in
place [0046] optionally applying an acid neutralizing composition
(e.g., solution or dispersion) to the stained cementitious or
mineral surface. Neutralizing compositions (e.g., solutions or
dispersions) can include aqueous mixtures (preferably solutions) of
weak bases such as carbonate and bicarbonate salts such as sodium,
potassium, lithium, cesium, ammonium (bi)carbonate; or phosphate
salts such disodium, dipotassium, dilithium, dicesium, or
diammonium phosphate; or organic alkalinity sources such as
alkylamines and alkanolamines.
[0047] Preferred neutralizing solution contain preferably at least
10% molar equivalents of weak base, such as Sodium Bicarbonate,
based on the total acid equivalents in the acid staining
composition, more preferably at least 50% molar equivalents of weak
base based on the total acid equivalents in the acid staining
composition, and most preferably at least 100% molar equivalents of
weak base based on the total acid equivalents in the acid staining
composition.
[0048] The practice of the present invention may further involve
applying an at least partially transparent, protective coating onto
the previously stained cementitious or mineral substrate. The
protective coating can be applied directly on the substrate.
Alternatively, one or more intervening layers may be interposed
between the substrate and the protective coating. Often, the
application of a protective coating, particularly those that are
substantially transparent, enhances and further realizes the color
development of the stained substrate.
[0049] A wide variety of protective coatings may be used. Under
certain circumstances it may be desirable to apply a wax clear
coating to the previously stained substrate (e.g., concrete,
cementitious or mineral substrate). Typical waxes useful in the
present invention include: natural plant or beeswaxes, paraffin,
carnauba, and these aforementioned natural waxes modified with
organic polymers such as polyethylene, polypropylene, or
polytetrafluoroethylene.
[0050] Polymeric protective coatings also may be used. Typical
polymers useful in the present invention to form protective
coatings include: acrylic, styrene-acrylic, polyurethane,
polyester, alkyd, epoxy-ester, silicone, and epoxy-amide. It is
particularly advantageous to utilize polymer chemistries which
crosslink after application over the stained concrete. Examples of
suitable crosslinking polymers would be those employing air curable
drying oil functionality, epoxy-amide reactions, siloxane
condensation, hydrazide-carbonyl reactions, aziridine-acid
reactions, isocycante-hydroxy reactions, or carbodiimide-acid
reactions. Also suitable are radiation curable (e.g., UV, visible
or electron-beam curable) coatings. Preferred are those chemistries
that offer a high degree of wear resistance. For consumer or
field-applied applications, most preferred are air drying
epoxy-esters, two component epoxy amides, air curable alkyds, and
aziridine crosslinked polyurethanes. For factory-applied uses
(e.g., when manufacturing stained fiber cement substrates) it is
preferred to use two-component crosslinking technologies (e.g.
isocyanate, melamine, unsaturation, or epoxy crosslinking), powder
coatings, laminates, waterborne thermoplastic coating systems
(e.g., latex, more preferably a crush resistance latex such as is
described in U.S. patent application Ser. No. 11/560,329),
fluoropolymer, thermal or radiation cure coatings (ultraviolet
light (UV), visible light, near infra-red (NIR), or e-beam cured),
and the like. Preferred factory applied finishes are radiation
curable waterborne or 100% solids coatings.
[0051] Suitable radiation curable protective coating compositions
may include olefinic oligomers or polymers, which may be anhydrous
or waterborne. One example of a suitable olefinic oligomeric or
polymeric material is a (meth)acrylate material. As used herein a
reference to a (meth)acrylate material is meant to include
methacrylate materials and acrylate materials. Suitable olefinic
oligomers or polymers include urethanes, epoxies, acrylics,
polyesters, melamines, amines and mixtures thereof. Suitable
urethanes include CN 929, CN 963, CN 980, CN 981, CN 982, CN 983,
CN 9001 from SARTOMER, and Bayhydrol 2348, 2282, and 2317 from
BAYER Material Sciences. Suitable epoxies include CN 104, CN 120,
CN121 and CN 151 from SARTOMER. Suitable acrylics include CN 816
from SARTOMER, Suitable polyesters include CN2200, CN2257, CN2258,
CN2259, and CN2260 from SARTOMER., Suitable melamines include CN
9890 from SARTOMER. Suitable amines include CN 501, CN 550, CN 551,
and CN 2100 from SARTOMER.
[0052] The radiation curable coating composition may include a
crosslinkable diluent. The crosslinkable diluent typically includes
olefinic monomer material for crosslinking with the unsaturated
oligomers or polymers and for decreasing the viscosity of the
coating so that standard coating techniques and equipment can be
used. One example of suitable olefinic monomer material is
(meth)acrylate monomer material. Suitable (meth)acrylate monomers
which may be employed have at least one (meth)acrylate functional
group, e.g., acrylate and methacrylate compounds and functional
derivatives thereof. Examples of (meth)acrylate monomer materials
include mono-, di-, tri-, tetra- and penta-functional
(meth)acrylate materials typically having a molecular weight in the
range of about 50 to about 750. Many such materials, are described
in P. K. T. Oldring "Chemistry & Technology of UV & EB
Formulation for Coatings, Inks & Paints", Volume II, 1991, SITA
Technology. When the (meth)acrylate monomer material is used, it is
preferably about 10 to 70 wt. %, and more preferably about 20 to 60
wt. %, of the coating composition.
[0053] Suitable (meth)acrylate monomer materials may include one or
more different (meth)acrylate monomers, each monomer having one or
more (meth)acrylate groups. The (meth)acrylate functional groups of
the (meth)acrylate monomers are bonded to core structural groups
which may be based on a wide variety of organic structures
including tripropylene glycol, isobornyl alcohol, isodecyl alcohol,
phenoxyethyl alcohol, trishydroxyethyl isocyanurate,
trimethylolpropane ethoxylate, hexanediol, ethoxylated and
propoxylated neopentyl glycol, oxyethylated phenol, polyethylene
glycol, bisphenol ethoxylate, neopentyl glycol propoxylate,
trimethylolpropane, propoxylated glycerol, pentaerythritol,
tetrahydrofurfuryl alcohol, .beta.-carboxyethyl alcohol,
substituted derivatives of the above, combinations of the above,
and the like.
[0054] One purpose of the (meth)acrylate monomer material is
viscosity reduction of coating compositions that contain olefinic
oligomers or polymers. In addition, (meth)acrylate monomers may
confer or enhance desirable characteristics, such as chemical
resistance and hardness to the coating composition. It is thought
that the presence of several (meth)acrylate groups on each
substituent of the monomer results in multiple interactions between
each monomer and resin molecule in the cured composition. These
multiple interactions can result in increased chemical resistance,
abrasion resistance, and/or hardness.
[0055] Examples of suitable (meth)acrylate monomers include
isobornyl (meth)acrylate, isodecyl(meth)acrylate,
phenoxyethyl(meth)acrylate, trimethylolpropane ti(meth)acrylate,
trimethylolpropane ethoxylate tri(meth)acrylate, tripropylene
glycol di(meth)acrylate, dipropyleneglycol di(meth)acrylate,
ditrimethylolpropane tetra(meth)acrylate, hexanediol
di(meth)acrylate, tetrahydrofurfuryl(meth)acrylate,
.beta.-carboxyethyl (meth)acrylate, bisphenol A ethoxylate
di(meth)acrylate, and ethoxylated and propoxylated neopentyl glycol
di(meth)acrylates.
[0056] Another example of a suitable olefinic monomer material,
which may be employed as a crosslinkable diluent, is an allyl ether
monomer material. Suitable allyl ether monomer materials include
one or more different ally! ether monomers, each monomer having one
or more allyl ether groups. The ally! ether functional groups of
the ally! ether monomers are bonded to a core structural group,
which is based on a wide variety of polyhydric alcohols. Suitable
polyhydric alcohols include neopentyl glycol, trimethylolpropane,
ethylene glycol, propylene glycol, butylene glycol, diethylene
glycol, trimethylene glycol, triethylene glycol, trimethylolethane,
pentaerythritol, glycerol, diglycerol, 1,4-butanediol,
1,6-hexanediol, 1,4-cyclohexanedimethanol, and the like.
[0057] Examples of suitable allyl ether monomers include
hydroxyethyl allyl ether, hydroxypropyl allyl ether,
trimethylolpropane monoallyl ether, trimethylolpropane diallyl
ether, trimethylolethane monoallyl ether, trimethylolethane diallyl
ether, glycerol monoallyl ether, glycerol diallyl ether,
pentaerythritol mono allyl ether, pentaerythritol diallyl ether,
pentaerythritol triallyl ether, 1,2,6-hexanetriol monoallyl ether,
1,2,6-hexanetriol diallyl ether, and the like. Propoxylated and
ethoxylated forms of these compounds are also suitable.
[0058] Another example of a suitable olefinic monomer material is
vinyl ether monomer material. The vinyl ether monomer material
includes one or more different vinyl ether monomers, each monomer
having one or more vinyl ether groups. Examples of suitable vinyl
ether monomers include 4-hydroxybutyl vinyl ether,
1,4-cyclohexanedimethanol monovinyl ether,
1,4-cyclohexanedimethanol divinyl ether, ethylene glycol monovinyl
ether, ethylene glycol divinyl ether, diethylene glycol monovinyl
ether, diethylene glycol divinyl ether, triethylene glycol divinyl
ether, and the like. Propoxylated and ethoxylated forms of these
compounds are also suitable.
[0059] The crosslinkable diluent may include a mixture of
(meth)acrylate, allyl ether, and vinyl ether monomer materials. In
addition, the crosslinkable diluent can be supplemented by addition
of other olefinic monomer materials. Such monomer materials include
functional materials such as vinyl ether maleate monomers, and the
like.
[0060] Some preferred coating compositions of the present
invention, particularly those with (meth)acrylate functional
groups, are curable by UV or visible light. These coating
compositions typically include a photoinitiator that induces the
curing reaction upon exposure to light. The photoinitiator
typically generates free radicals in response to a particular
wavelength range of light to initiate a free radical reaction that
crosslinks the acrylate double bonds of the resin and
(meth)acrylate monomer material, thereby curing the coating.
[0061] Among photoinitiators suitable for use in the present
invention with resins having (meth)acrylate or allyl ether
functional groups are .alpha.-cleavage type photoinitiators and
hydrogen abstraction type photoinitiators. The photoinitiator
preferably makes up about 0.5 to 15 wt. % of the coating
composition. The photoinitiator may include other agents such as a
coinitiator or photoinitiator synergist that aid the photochemical
initiation reaction.
[0062] Suitable cleavage type photoinitiators of the invention
include, .alpha..,.alpha..-diethoxyacetophenone (DEAP);
dimethoxyphenylacetophenone (Irgacure 651);
hydroxycyclo-hexylphenylketone (Irgacure 184);
2-hydroxy-2-methyl-1-phenylpropan-1-one (Darocur 1173); Irgacure
1700, and Darocur 4265 all from Ciba Corporation, Ardsley, N.Y.
Irgacure 1700 is a 25:75 blend of
bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide
and 2-hydroxy-2-methyl-1-phenylpropan-1-one. Darocur 4265 is a
50:50 blend of 2-hydroxy-2-methyl-1-phenylpropan-1-one and
2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO). Lucirin TPO
photoinitiator (2,4,6-trimethylbenzoyl-diphenylphosphine oxide) of
BASF Corporation and KIP 100 photoinitiator (a mixture of 70% oligo
[2-hydroxy-2-methyl-[4-(1-methylvinyl)phenyl]propan-1-one] and 30%
2-hydroxy-2-methyl-1-phenylpropan-1-one) available from Sartomer
are also suitable.
[0063] Suitable hydrogen abstraction-type photoinitiators include
benzophenone, substituted benzophenones (e.g., Escacure TZT of
Fratelli-Lamberti) and other diaryl ketone such as xanthones,
thioxanthones, Michler's ketone, benzil, quinones, and substituted
derivatives of all of the above.
[0064] Irgacure 500 is a mixture of Irgacure 184 and benzophenone,
in a 1:1 ratio, and is a good example of a mixture of an
.alpha..-cleavage type photoinitiator and a hydrogen
abstraction-type photoinitiator. Other mixtures of photoinitiators
may also be used in the coating composition. Preferred
photoinitiators include Darocur 1173, KIP 100, benzophenone, and
Irgacure 184. Camphorquinone is one example of a suitable
photoinitiator for curing a coating composition with visible
light.
[0065] The present coating composition may also include a
coinitiator or photoinitiator synergist. The coinitiators can be
(1) tertiary aliphatic amines like methyl diethanol amine and
triethanol amine; (2) aromatic amines like
amylparadimethylaminobenzoate, 2-n-butoxyethyl-4-(dimethylamino)
benzoate, 2-(dimethylamino)ethylbenzoate,
ethyl-4-(dimethylamino)benzoate, and
2-ethylhexyl-4-(dimethylamino)benzoate; (3) (meth)acrylated amines
like Ebecryl 7100 and Uvecryl P104 and P115, all from UCB RadCure
Specialties; and (4) amino-functional acrylate or methacrylate
resin or oligomer blends such as Ebecryl 3600 or Ebecryl 3703, both
from UCB RadCure Specialties. Combinations of the above four
categories of amines may also be used.
[0066] Coating compositions with vinyl ether functional groups can
be cured by UV or visible light using cationic-generating
photoinitiators. Examples of suitable cationic-generating
photoinitiators include super acid-generating photoinitiators, such
as triarylsulfonium salts. One useful triarylsulfonium salt is
triphenyl sulfonium hexafluorophosphate, Ph.sub.3 S.sup.+
PF.sub.6.--(available from Union Carbide as UVI 6990).
[0067] Many coating compositions, which may be cured by UV or
visible light, may also be cured with an electron beam. Techniques
and devices for curing a coating composition using an electron beam
are known in the art and typically do not require a
photoinitiator.
[0068] The curable coating composition may also include one of a
group of ingredients that can be called performance enhancing
additives. The coating composition may contain more than one
performance enhancing additive. Typical performance enhancing
additives which may be employed in the curable coating composition
include a surface active agent, a pigment, a curing indicator, a
filler, a UV absorber, a hindered amine light stabilizer (HALS),
and an optical brightener.
[0069] The curable coating composition may include a surface active
agent which modifies the interaction of the curable coating
composition with the substrate, in particular, the agent can modify
the ability of the composition to wet a substrate. Surface active
agents may have other properties as well. For example, surface
active agents may also include leveling, defoaming, or flow agents,
and the like. The surface active agent affects qualities of the
curable coating composition including how the coating composition
is handled, how it spreads across the surface of the substrate, and
how it bonds to the substrate. The surface active agent may
preferably make up about 0.1 to 3% by weight of the curable coating
composition. Exemplary surface active agents include
polydimethylsiloxane surface active agents (e.g., Silwet L-7602,
Silwet L-7622; OSI Specialties or Byk 306, Byk-Chemie) and
fluorinated surface active agents (e.g., Fluorad FC-430; 3M
Company). The surface active agents may include a defoamer.
Suitable defoamers include polysiloxane defoamers, such as a
methylalkylpolysiloxane like Byk 077 or Byk 500 (Byk-Chemie), or
polymeric defoamers (e.g., Byk 051; Byk-Chemie).
[0070] For some applications, a coating that is at least partially
transparent, colored, pigmented and/or has other visual
characteristics is desired. Agents to provide such properties are
also included in the invention. The composition can also include a
gloss control additive or an optical brightener, such as Uvitex OB,
from Ciba-Geigy.
[0071] In certain instances it is advantageous to include fillers
or inert ingredients in the protective coating composition. Fillers
and inert ingredients include, for example, clay, glass beads,
calcium carbonate, talc, silicas, organic fillers, and the like.
Fillers extend, lower the cost of, alter the appearance of, or
provide desirable characteristics to the composition before and
after curing. Suitable fillers are known to those of skill in the
art or can be determined using standard methods. Fillers or inert
ingredients, when present, preferably comprise up to 40% by weight
of the coating composition, more preferably from 0.5 to 40 wt.
%.
[0072] The protective coating compositions may also include other
ingredients such as those which modify properties of a curable
coating composition as it is stored, handled, or applied, and at
other or subsequent stages. Waxes, flatting agents, mar and
abrasion additives, and other similar performance enhancing
additives may be employed in this invention as required in amounts
effective to upgrade the performance of the cured coating and the
coating composition. Desirable performance characteristics of the
coating include chemical resistance, abrasion resistance, hardness,
gloss, reflectivity, appearance, or combinations of these
characteristics, and other similar characteristics.
[0073] A variety of other optional additives may be used in
protective coating compositions and will be familiar to persons
having ordinary skill in the art, including those described in
Koleske et al., Paint and Coatings Industry, April 2003, pages
12-86. For example, the final topcoat compositions may include one
or more performance or property enhancing additives such as
colorants, dyes, thickeners, heat stabilizers, leveling agents,
anti-cratering agents, curing indicators, plasticizers,
sedimentation inhibitors, ultraviolet-light absorbers, and the
like. Also, for application using factory coating equipment (e.g.,
curtain coaters), the composition may employ additives tailored to
the chosen equipment and installation. Such additives typically are
selected on a site-by-site basis using standard methods that will
be familiar to persons having ordinary skill in the art.
[0074] The coloring composition can be applied by any conventional
means known to those skilled in the art, for example by rolling,
spraying, ink jet deposition, or brushing it onto the substrate
(e.g., concrete surface). In factory applied settings the suitable
methods also include curtain coating, and other methods of applying
coatings to a moving substrate. Typically, the method of
application will affect the final outcome. For example, spraying on
the stain will create a more natural look, while brushing will
create a more uniform outcome. The use of multiple coats involving
different stains will create a greater variety of successful color
choices. If desired, one may spray in a pattern or even pre-deposit
a "resist" atop the substrate to cause the subsequently applied
stain to differentially stain the area where the resist was
applied. In one embodiment, the resist is a hydrophobic material,
that inhibits the applied stain from wetting the concrete surface.
Suitable hydrophobic materials include, for example, waxes (e.g.,
paraffin wax), oils (e.g., mineral oil), or a volatile hydrophobic
solvent (e.g., aromatic 150). Preferred resist materials cause the
applied stain to "bead up" on the surface of the concrete. The
resist can be applied in any desirable design. In another
embodiment a volatile resist is applied to the concrete in a
desired pattern, the stain is applied to the concrete and allowed
to dry, the volatile hydrophobic resist is allowed to evaporate
thus rendering the resist treated area stainable, and subsequent
application of stain is applied to the previously resist treated
area. In a further embodiment, a volatile hydrophobic resist is
applied to the concrete in a desired pattern, the stain is applied
to the concrete and allowed to dry, the volatile hydrophobic resist
is allowed to evaporate thus rendering the resist treated area
stainable, a second application of a volatile hydrophobic resist is
applied to the concrete in a desired pattern which is different
than the previous pattern, and a subsequent application of stain is
applied to the concrete. The above application methods can be
repeated several times to form a complex design on the
concrete.
EXAMPLES
[0075] The following are non-limiting examples of stain
compositions that serve to further illustrate advantages of the
disclosed invention.
Example 1
[0076] This example and the next describe coloring compositions in
which the acidic characteristics are developed in situ from
ingredients that are easily handled. The urea monohydrochloride is
a stable, solid and is a chloride salt of a protonated urea. When
dissolved in water, while not intending to be bound by theory, the
compound is believed to dissociate into hydrogen ions, aqueous urea
species that are believed to include at least urea in equilibrium
with a conjugate acid, and chloride anions. When the composition
reacts with a cementitious substrate, it is believed that at least
a portion of the aqueous urea species decompose into products
including ammonia and carbonic acid. The carbonic acid in turn
decomposes to water and CO.sub.2. The ammonia is a stronger base
than the urea, and the formation of the stronger base could help
self-neutralization of the composition. Potentially, the
degradation of the urea also may release additional acidic species
to enhance the etching performance of the composition.
Schematically, the urea or bases with similar decomposition
characteristics can be viewed as shielding and controllably
releasing the acid potential of the composition, thus rendering the
acid safer to use and yet still be effective. The FeCl.sub.2 is not
only a salt that provides coloring action, but it is also a Lewis
acid. In aqueous solution, the dissociation of one mole of this
salt is believed to generate about two moles of hydrogen ions.
TABLE-US-00001 Material Weight (lb) Vol (gal.) Water 54.75 6.57
Urea monohydrochloride 9 0.89 32% FeCl2 solution 37.5 3.51 Silicone
defoamer* 0.1 0.011 Total 101.35 10.98 *Proprietary commercially
available foam destroying polymers and polysiloxanes
This example provides for a "fawn" or tan colored stain
material.
Example 2
TABLE-US-00002 [0077] Material Weight (lb) Vol (gal.) Water 48.26
5.79 Urea monohydrochloride 9 0.89 CuCl2.cndot.2H2O 15.3 0.72 Water
18 2.16 32% FeCl2 solution 9 0.84 Silicone defoamer* 0.1 0.012
Total 99.66 10.41 *Proprietary commercially available foam
destroying polymers and polysiloxanes
This example provides for an olive-colored or green stain
material.
Example 3
TABLE-US-00003 [0078] Material Weight (lb) Vol (gal.) Water 19.89
2.38 Urea monohydrochloride 9.89 0.98 Silicone defoamer* 0.1 0.011
FeCl2 solution, 40% 31.25 2.67 MnCl2.cndot.4H2O 21.43 1.27 Urea
monohydrochloride 1.75 0.17 Water 15.78 1.89 Total 100.09 9.37
*Proprietary commercially available foam destroying polymers and
polysiloxanes
This example provides for a "coffee" or brownish colored stain
material.
Example 4
[0079] The "fawn" colored stain material from Example 1 was applied
to a cement fiber board substrate and allowed to dry. A fawn color
developed. The color is more fully realized following application
of topcoats described below.
Examples 4a
Electron Beam Curable Topcoat
[0080] The resulting stained board from Example 4 was topcoated
with an electron beam cured coating comprising 132.5 parts CN991
(Sartomer) and 56.8 parts hexanediol diacrylate (Sartomer). The
coating was cured by an electron beam supplied by AEB (Wilmington,
Mass.) at 150 kV, 50 feet/minute line speed, oxygen at 500 ppm, and
a beam setting of 10. The resulting coating was a hard durable
protective topcoat.
Examples 4b
Ultraviolet Curable Topcoat
[0081] The resulting stained board from Example 4 was topcoated
with an ultraviolet cured coating comprising 132.5 parts CN991
(Sartomer), 56.8 parts hexanediol diacrylate (Sartomer), and 10
parts KIP100 (Sartomer). The coating was cured by two 300 watt/inch
medium pressure mercury lamps at a line speed of 60 feet per minute
The resulting coating was a hard durable protective topcoat.
Examples 4c
Thermoplastic Topcoat
[0082] The resulting stained board from Example 4 was topcoated
with a waterbased latex/fluoropolymer blend coating comprising
159.1 parts XK-90 (DSM, Elgin, Ill.), 143.19 parts Lumiflon 4300
(Asahi Glass Company), and 25 parts water. The coating was dried in
a 300.degree. F. (149 .degree. C.) oven until a board surface
temperature of 200.degree. F. (93.3.degree. C.) was achieved.
[0083] The resulting coating was a hard durable protective
topcoat.
Examples 4d
Ultraviolet Curable Topcoat
[0084] The resulting stained board from Example 4 is topcoated with
a waterbased ultraviolet cured coating consisting of 100 parts
Bayhydrol UV LS 2317 and 1.5 parts Irgacure 500 (Ciba). The coating
is cured by either first air drying until "dry to touch" or drying
in a 300.degree. F. (149 .degree. C.) hot air oven to a BST (board
surface temperature) of approximately 160 to 180.degree. F. (71 to
82.degree. C.) followed by two 300 watt/inch medium pressure
mercury lamps at a line speed of 60 feet per minute.
[0085] The resulting coating is expected to be a hard durable
protective topcoat.
Example 5
[0086] The "coffee" colored stain material from Example 3 was
applied to a cement fiber board substrate and allowed to dry.
Examples 5a
Electron Beam Curable Topcoat
[0087] The resulting stained board from Example 5 was topcoated
with an electron beam cured coating comprising 132.5 parts CN991
(Sartomer) and 56.8 parts hexanediol diacrylate (Sartomer). The
coating was cured by an electron beam supplied by AEB (Wilmington,
Mass.) at 150 kV, 50 feet/minute line speed, oxygen at 500 ppm, and
a beam setting of 10.
[0088] The resulting coating was a hard durable protective
topcoat.
Examples 5b
Ultraviolet Curable Topcoat
[0089] The resulting stained board from Example 5 was topcoated
with an ultraviolet cured coating comprising 132.5 parts CN991
(Sartomer), 56.8 parts hexanediol diacrylate (Sartomer), and 10
parts KIP 100 (Sartomer). The coating was cured by two 300
watt/inch medium pressure mercury lamps at a line speed of 60 feet
per minute The resulting coating was a hard durable protective
topcoat.
Examples 5c
Thermoplastic Topcoat
[0090] The resulting stained board from Example 5 was topcoated
with a waterbased latex/fluoropolymer blend coating comprising
159.1 parts XK-90 (DSM, Elgin, Ill.), 143.19 parts Lumiflon 4300
(Asahi Glass Company), and 25 parts water. The coating was dried in
a 300.degree. F. (149.degree. C.) oven until a board surface
temperature of 200.degree. F. (93.3.degree. C.) was achieved.
[0091] The resulting coating was a hard durable protective
topcoat.
Examples 5d
Ultraviolet Curable Topcoat
[0092] The resulting stained board from Example 5 is topcoated with
a waterbased ultraviolet cured coating consisting of 100 parts
Bayhydrol UV LS 2317 and 1.5 parts Irgacure 500 (Ciba). The coating
is cured by either first air drying until "dry to touch" or drying
in a 300.degree. F. (149.degree. C.) hot air oven to a BST (board
surface temperature) of approximately 160 to 180.degree. F. (71 to
82.degree. C.) followed by two 300 watt/inch medium pressure
mercury lamps at a line speed of 60 feet per minute.
[0093] The resulting coating is expected to be a hard durable
protective topcoat.
[0094] These embodiments or examples should be considered to be
non-limiting and are presented to illustrate just a few of the
possibilities of the compositions and methods of the present
invention. While the principles of this invention have been
described in connection with specific embodiments, it should be
clearly understood that these descriptions are made only by way of
example and are not intended to limit the scope of the invention.
As such, the present invention may be embodied in other specific
forms without departing from the spirit or essential attributes
thereof, and, accordingly, reference should be made to the appended
claims, rather than to the foregoing specification as indicating
the scope of the invention.
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