U.S. patent application number 10/164811 was filed with the patent office on 2002-11-28 for latex made with crosslinkable surface active agent.
This patent application is currently assigned to Rhodia, Inc.. Invention is credited to Jakob, Paul, Kiplinger, Jon D., Pratt, Charles E..
Application Number | 20020177655 10/164811 |
Document ID | / |
Family ID | 21971488 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020177655 |
Kind Code |
A1 |
Pratt, Charles E. ; et
al. |
November 28, 2002 |
Latex made with crosslinkable surface active agent
Abstract
A composition comprising a polymer dispersion wherein said
polymer is formed by reacting in the presence of water and in the
presence of the reaction product of (i) one or more carboxylic
fatty acids; and (ii) ammonia or one or more polyfunctional
aromatic or aliphatic amines: (1) one or more ethylenically
unsaturated monomers which is capable of polymerizing in an aqueous
environment is provided.
Inventors: |
Pratt, Charles E.;
(Bethlehem, PA) ; Jakob, Paul; (Easton, PA)
; Kiplinger, Jon D.; (Bordentown, NJ) |
Correspondence
Address: |
CHARLES N.J. RUGGIERO, ESQ
OHLANDT, GREELEY, RUGGIERO & PERLE, L.L.P.
ONE LANDMARK SQUARE, 10th FLOOR
STAMFORD
CT
06901-2682
US
|
Assignee: |
Rhodia, Inc.
|
Family ID: |
21971488 |
Appl. No.: |
10/164811 |
Filed: |
June 7, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10164811 |
Jun 7, 2002 |
|
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|
09105766 |
Jun 26, 1998 |
|
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60051468 |
Jul 1, 1997 |
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Current U.S.
Class: |
524/802 ;
524/804 |
Current CPC
Class: |
B27K 3/15 20130101; C08K
3/22 20130101; C08L 33/06 20130101; C09K 3/18 20130101; C08K 5/21
20130101; C08F 220/14 20130101; C08F 220/1804 20200201; C08L 97/02
20130101; C08L 97/02 20130101; C08L 33/06 20130101 |
Class at
Publication: |
524/802 ;
524/804 |
International
Class: |
C08K 003/00 |
Claims
What is claimed is:
1. A composition comprising a polymer dispersion wherein said
polymer is formed by reacting in the presence of water and in the
presence of the reaction product of (i) one or more carboxylic
fatty acids; and (ii) ammonia or one or more polyfunctional
aromatic or aliphatic amines: (1) one or more ethylenically
unsaturated monomers which is capable of polymerizing in an aqueous
environment.
2. The composition according to claim 1 wherein the reaction
product of component (1) is a polymer having an average particle
size ranging from about 1 and about 2000 nanometers.
3. The composition according to claim 2 wherein said polymer has an
average particle size of less than about 200 nanometers.
4. The composition according to claim 3 wherein said polymer has an
average particle size of less than about 100 nanometers.
5. The composition according to claim 1 wherein component (1) is
selected from the group consisting of (meth)acrylic based esters,
acrylonitrile, styrene, divinylbenzene, vinyl acetate,
2-hydroxyethyl methacrylate, 2-ethylhexyl acrylate, acrylamide,
methacrylamide, vinylidene chloride, butadiene and vinyl chloride
and mixtures thereof.
6. The composition according to claim 1 wherein said reaction
product is the reaction product of (i) one or more carboxylic fatty
acids of 3 to 30 carbon atoms; and (ii) one or more
hydroxy-substituted amines containing from 2 to 25 carbon
atoms.
7. The composition according to claim 6 wherein said one or more
carboxylic fatty acids is selected from the group consisting of
coconut fatty acid, decanoic acid, lauric acid, stearic acid,
isostearic acid, riconoleic acid, tall oil fatty acid, trisdecanoic
acid, myristic acid, palmitic acid and mixtures thereof.
8. The composition according to claim 6 wherein said
hydroxy-substituted amine is selected from the group consisting of
triethanolamine, 2-amino-2-ethyl-1,3-propanediol,
2-amino-2-methyl-1-propanol and tris(hydroxymethyl)aminomethane and
mixtures thereof.
9. The composition according to claim 1 further comprising: (2) a
water soluble or water dispersible metal complex cross-linking
agent.
10. The dispersion according to claim 9 wherein component (2) is
selected from the group consisting of metal salts of zinc,
aluminum, titanium, copper, chromium, iron, zirconium and lead and
mixtures thereof.
11. The dispersion according to claim 10 wherein component (2)
comprises ammonium zirconium carbonate.
12. The dispersion according to claim 1 further comprising
performance enhancing chemicals selected from the group consisting
of defoaming agents, waxes, additional surface active agents,
plasticizers, pigments, colorants, dyes, freeze thaw stabilizers,
antibacterials and mixtures thereof.
13. The dispersion according to claim 2 wherein said polymer has a
glass transition temperature of less than about 80.degree. C.
14. The dispersion according to claim 1 comprising between about 4
to about 30 parts by weight of said reaction product for every 100
parts by weight of component (1).
15. The dispersion according to claim 14 comprising between about
15 to about 25 parts by weight of said reaction product for every
100 parts by weight of component (1).
16. A dispersion consisting essentially of an aqueous composition
which is water repellent when coated and dried onto a surface which
is formed by reacting in the presence of water and in the presence
of the reaction product of (i) one or more carboxylic fatty acids
having between 8 and 18 carbon atoms; and (ii) one or more
polyfunctional aromatic or aliphatic amines which is selected from
the group consisting of triethanolamine,
2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol and
tris(hydroxymethyl)aminomethane and mixtures thereof: (1) butyl
acrylate and methyl methacrylate; methyl methacrylate, butyl
acrylate and 2-hydroxyethyl methacrylate; or butyl methacrylate and
2-ethylhexyl acrylate to form a polymer; and (2) thereafter adding
to said polymer ammonium zirconium carbonate.
17. A method for synthesizing a polymer dispersion comprising
reacting in the presence of water and in the presence of the
reaction product of (i) one or more carboxylic fatty acids; and
(ii) ammonia or one or more polyfunctional aromatic or aliphatic
amines: (1) one or more ethylenically unsaturated monomers which is
capable of polymerizing in an aqueous environment.
18. The method according to claim 17 comprising the additional step
of adding to said polymer a water soluble or water dispersible
metal complex cross-linking agent.
19. The method according to claim 18 wherein said water soluble or
water dispersible metal complex cross-linking agent comprises
ammonium zirconium carbonate.
20. A substrate having water resistant properties wherein said
water resistant properties are obtained by coating and drying onto
one or more surfaces of the substrate an aqueous dispersion of: (A)
a polymer produced by reacting in an aqueous environment and in the
presence of the reaction product of (i) one or more carboxylic
fatty acids; and (ii) one or more polyfunctional aromatic or
aliphatic amines: (1) one or more ethylenically unsaturated
monomers which is capable of polymerizing in an aqueous
environment; and (B) a water soluble or water dispersible metal
complex cross-linking agent.
21. The substrate according to claim 20 which is selected from the
group consisting of wood, paper, and other cellulosic materials,
textiles, stone, brick, masonry, cement, concrete, surface
coatings, metals, roofing materials, powders, inks, leather,
textiles and adhesives.
22. A method for rendering a substrate water resistant comprising
the step of coating and drying onto one or more surfaces of said
substrate an aqueous dispersion of: (A) a polymer produced by
reacting in an aqueous environment and in the presence of the
reaction product of (i) one or more carboxylic fatty acids; and
(ii) one or more polyfunctional aromatic or aliphatic amines: (1)
one or more ethylenically unsaturated monomers which is capable of
polymerizing in an aqueous environment; and (B) a water soluble or
water dispersible metal complex cross-linking agent.
23. The method according to claim 22 wherein said dispersion is
selected from the group consisting of paints, stains, millwork
protective coatings, siding protective coatings, wood fiber cement
protective coatings, roof tile/panel protective coatings, building
lumber protective coatings, and deck treatment protective
coatings.
24. A substrate having water resistant properties wherein said
water resistant properties are obtained by coating and drying onto
one or more surfaces of the substrate an aqueous dispersion of a
polymer produced by polymerizing in an aqueous environment and in
the presence of the reaction product of (i) one or more carboxylic
fatty acids; and ammonia one or more ethylenically unsaturated
monomers.
25. The substrate according to claim 24 which is selected from the
group consisting of wood, paper, and other cellulosic materials,
textiles, stone, brick, masonry, cement, concrete, surface
coatings, metals, roofing materials, powders, inks, leather,
textiles and adhesives.
26. A method for rendering a substrate water resistant comprising
the step of coating and drying onto one or more surfaces of said
substrate an aqueous dispersion of a polymer produced by
polymerizing in an aqueous environment and in the presence of the
reaction product of (i) one or more carboxylic fatty acids; and
(ii) ammonia one or more ethylenically unsaturated monomers.
27. The method according to claim 22 wherein said dispersion is
selected from the group consisting of paints, stains, millwork
protective coatings, siding protective coatings, wood fiber cement
protective coatings, roof tile/panel protective coatings, building
lumber protective coatings, and deck treatment protective coatings.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a coating/impregnating
composition. More specifically, the composition is a latex which is
formed by polymerizing monomers in the presence of crosslinkable
surface active agents to form a dispersion, and then sequentially
admixing said polymer dispersion with a crosslinking agent. The
mixture of the latex synthesized in this manner and the
crosslinking agent produces a material which can be coated onto a
substrate to provide a water resistant coating.
[0003] 2. Technology Description
[0004] U.S. Pat. No. 5,409,527 is directed to an aqueous water
repellent composition comprising the reaction product of one or
more of a carboxylic acid or anhydride containing from 3 to 22
carbon atoms and a polyfunctional aromatic or aliphatic amine or
substituted amine containing from 2 to 25 carbon atoms with a water
soluble metal complex crosslinking agent containing one or more
metals selected from Groups Ia, IIa, IIIa, IVa and the first and
second rows of transition metals from the Periodic Table of
Elements. The composition may contain wax and is dispersed in water
to form a water repellent system. This patent further discusses the
possibility of adding an aqueous acrylic polymer to the resulting
composition. The reference fails to suggest that the polymer can be
synthesized by polymerizing the monomer in the presence of a
crosslinkable surface active agent. The only mention of polymer
dispersions are commercial polymers made with conventional
polymerization surfactants. It would be desirable to undertake a
synthesis where the monomers are polymerized in the presence of a
crosslinkable surface active agent thereby reducing or eliminating
altogether the conventional polymerization surface active agents
which would tend to attract moisture to substrates which are coated
or impregnated with such polymers that were made with the
conventional surface active agents. On the other hand, if the
monomers were polymerized in the presence of crosslinkable surface
active agents, the resulting material would possess outstanding
water repellent properties when subsequently reacted with a
crosslinking agent. In addition, by making the polymerization with
crosslinkable surfactants, the resulting polymer dispersion could
be produced having a desired particle size profile. This reference
fails to disclose or suggest such an embodiment.
[0005] Despite the above teachings, there still exists a need in
the art for a method for producing a dispersion wherein monomers
are added to an aqueous environment containing a crosslinkable
surface active agent and thereafter polymerizing the monomers to
form a polymer dispersion having the desired particle size
properties, and after adding a crosslinking agent, has the ability
to impart outstanding water repellent properties to substrates.
BRIEF SUMMARY OF THE INVENTION
[0006] In accordance with the present invention a novel dispersion
is provided. More specifically, the dispersion comprises a polymer
dispersion wherein said polymer is formed by reacting in the
presence of water and in the presence of the reaction product of
(i) one or more carboxylic fatty acids; and (ii) ammonia or one or
more polyfunctional aromatic or aliphatic amines:
[0007] (1) one or more ethylenically unsaturated monomers which is
capable of polymerizing in an aqueous environment.
[0008] In preferred embodiments, the one or more ethylenically
unsaturated monomers of component (1) are acrylic compositions, and
more preferably acrylic esters; and the reaction product is the
product of (i) one or more carboxylic fatty acids of 3 to 30 carbon
atoms; and (ii) one or more hydroxy-substituted amines containing
from 2 to 25 carbon atoms.
[0009] In particularly preferred embodiments, a water soluble metal
complex crosslinking agent containing one or more metals selected
from Groups Ia, IIa, IIIa, IVa and the first and second rows of
transition metals from the Periodic Table of Elements is added to
the polymer/surface active agent dispersion. For a particularly
preferred embodiment, component (1) comprises a mixture of butyl
acrylate and methyl methacrylate; the surface active agent is the
reaction product of 2-amino-2-ethyl-1,3-propanediol with a single
or combination of fatty acids having a carbon number of 8-18; and
the crosslinking agent comprises ammonium zirconium carbonate.
[0010] The resulting composition comprises a dispersion having a
polymer particle size ranging from about 1 nanometer to about 2000
nanometers, and for specific applications, the reaction synthesis
can be controlled so that the resulting particle size of the
polymer is between about 1 to about 60 nanometers. Such a polymer
particle size would enable the dispersion to be coated onto and
fill surfaces having microscopic voids. This is particularly
important to provide water resistance to the coated surface. The
resulting dispersion also has a solids content in the amount of
about 0.1 to about 50 percent by weight of the resulting
dispersion.
[0011] Another embodiment of the present invention comprises a
method for synthesizing a polymer dispersion comprising reacting in
the presence of water and in the presence of the reaction product
of (i) one or more carboxylic fatty acids; and (ii) ammonia or one
or more polyfunctional aromatic or aliphatic amines:
[0012] (1) one or more ethylenically unsaturated monomers which is
capable of polymerizing in an aqueous environment.
[0013] Still another embodiment of the present invention comprises
a method for rendering a substrate water resistant comprising the
step of coating and drying onto one or more surfaces of said
substrate an aqueous dispersion of:
[0014] (A) a polymer produced by reacting in an aqueous environment
and in the presence of the reaction product of (i) one or more
carboxylic fatty acids; and (ii) one or more polyfunctional
aromatic or aliphatic amines:
[0015] (1) one or more ethylenically unsaturated monomers which is
capable of polymerizing in an aqueous environment; and
[0016] (B) a water soluble or water dispersible metal complex
cross-linking agent.
[0017] In preferred embodiments, the surface to be coated is made
of either wood, brick, stone, cement, concrete, roofing materials
and the like. In specific embodiments the coating composition can
either be in a "one package" or "two package" form. When using a
"one package" form, all of the components are present in a single
package and are thereafter coated and dried onto a substrate. In
the "two package" embodiment, component (B) is maintained in a
separate package from a package containing the remaining
components, and the two packages are mixed together just prior to
coating. The primary purpose for using a two package system is to
enable the production of dispersions having higher levels of
solids.
[0018] An object of the present invention is to provide a
dispersion which has excellent water resistant properties.
[0019] Still another object of the present invention is to provide
a method for making a dispersion which has excellent water
resistant properties.
[0020] A further object of the present invention is to provide a
method for rendering a surface water resistant by using a
dispersion which has excellent water resistant properties.
[0021] These, and other objects, will readily be apparent to those
skilled in the art as reference is made to the detailed description
of the preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] In describing the preferred embodiment, certain terminology
will be utilized for the sake of clarity. Such terminology is
intended to encompass the recited embodiment, as well as all
technical equivalents which operate in a similar manner for a
similar purpose to achieve a similar result.
[0023] The present invention relates to the formation of an aqueous
polymer dispersion. The dispersion is formed by the in situ
polymerization of one or more monomers in an aqueous environment
which contains the reaction product of one or more carboxylic fatty
acids and ammonia or one or more polyfunctional aromatic or
aliphatic amines as a surface active agent; and wherein the
dispersion may also contain a water soluble or water dispersible
metal complex cross-linking agent which is added after
polymerization has occurred to yield a water resistant
coating/impregnating composition.
[0024] The first component used to synthesize the dispersion of the
present invention is one or more ethylenically unsaturated monomers
which is capable of polymerizing in an aqueous environment.
Particularly preferred are any of the following monomers:
(meth)acrylic based esters, acrylonitrile, styrene, divinylbenzene,
vinyl acetate, acrylamide, methacrylamide, vinylidene chloride,
butadiene and vinyl chloride. The dispersion solids that are
produced may take the form of homopolymers (i.e., only one type of
monomer selected) or copolymers (i.e., mixtures of two or more
types of monomer are selected; this specifically includes
terpolymers and polymers derived from four or more monomers).
[0025] Most preferred monomers are acrylic based esters. These
monomers are preferably of the formula 1
[0026] where R.sub.1 is preferably hydrogen or an alkyl group
having from 1 to 4 carbon atoms and R.sub.2 is an aliphatic group
having from 1 to 20 carbon atoms. In most preferred embodiments,
R.sub.1 comprises hydrogen or a methyl group and R.sub.2 is an
alkyl group having from 1 to 20 carbon atoms. The substituent
R.sub.2 may further be substituted with additional organic groups
such as hydroxyl (OH), fluoro or silyl groups.
[0027] Specifically useful monomers falling within the scope of the
invention include methyl methacrylate, ethyl acrylate, butyl
acrylate, 2-hydroxyethyl methacrylate, styrene, butyl methacrylate,
2-ethylhexyl acrylate and mixtures thereof. Particularly preferred
is a mixture of methyl methacrylate and butyl acrylate. Another
preferred combination is a mixture of methyl methacrylate, butyl
acrylate and 2-hydroxyethyl methacrylate. Still another preferred
combination is a mixture of butyl methacrylate and 2-ethylhexyl
acrylate.
[0028] Other monomers or starting compounds which may be utilized
to produce latexes are well known to the art. Examples are set
forth in The Encyclopedia of Chemical Technology, Kirk-Othmer, John
Wiley & Sons, Vol. 14, pp. 82-97, (1981). To the extent
necessary, this passage is hereby incorporated by reference.
[0029] The next component, which is the surface active agent used
to form the inventive dispersion, is the reaction product of (i)
one or more carboxylic fatty acids; and (ii) one or more
polyfunctional aromatic or aliphatic amines. More preferably, this
component is the product of (i) one or more carboxylic fatty acids
of 3 to 30 carbon atoms and (ii) ammonia or one or more
hydroxy-substituted amines containing from 2 to 25 carbon
atoms.
[0030] The carboxylic fatty acid to be selected contains between 3
to about 30 carbon atoms, more preferably between about 8 to about
18 carbon atoms. The acid may take the form of a linear, branched,
cyclic or aromatic carboxylic acid. Specific acids which may be
selected to react with the amine include, but are not limited to,
decanoic acid, coconut fatty acid, lauric acid, stearic acid,
isostearic acid, riconoleic acid, tall oil fatty acid, trisdecanoic
acid, palmitic acid, myristic acid and mixtures thereof.
[0031] The amine to be selected is any which can be reacted with
the carboxylic fatty acid to yield a material which provides
surface active properties as a result of the formation of an amine
salt including the fatty moiety from the carboxylic acid. Examples
of amines which may be selected in accordance with the present
invention include, but are not limited to, triethanolamine,
2-amino-2-ethyl-1,3-propanediol (AEPD), 2-amino-2-methyl-1-propanol
(AMP) and tris(hydroxymethyl)aminomethane, with AEPD or
tris(hydroxymethyl)aminomethane being most preferred. Other
polyfunctional aromatic or aliphatic amines or substituted amines
which are preferred are those which are also water soluble so as to
produce a water dispersible compound when reacted with a carboxylic
acid. All the amines may be substituted optionally with hydroxyl
groups, for example, substituted diols and triols, and may be
selected from primary, secondary and tertiary amines containing
alkyl groups having 1 to 5 carbon atoms or hydrogen, typified by
amino methyl propanol, amino methyl propane diol, diamines typified
by hydrazine and hexamethylene diamine; cyclic amines; aromatic and
aliphatic amino acids typified by 3-methyl4-amino benzoic acid.
[0032] Ammonia can also be used in place of the polyfunctional
aromatic or aliphatic amine. When ammonia is selected as the amine,
it reacts with the carboxylic acid to yield an ammonium fatty acid
salt.
[0033] In practice the carboxylic acid and amine are simply reacted
by adding a powder or flaked form of the carboxylic acid at
elevated temperatures such that it will melt, typically about 50 to
about 100.degree. C., more preferably between about 65 to about
90.degree. C., and most preferably between about 70 to about
80.degree. C., to an agitated solution of the amine in water. The
mixture is agitated for a sufficient period of time necessary to
enable the formation of an amine salt. The agitation time is
considered well within the skill of one in the art and typically
occurs for a time period until the resulting product is a clear
liquid. In preferred embodiments, the agitation time is between
about 2 to about 90 minutes, more preferably between about 5 and
about 30 minutes and most preferably about 5 to 10 minutes.
[0034] The amount of amine/carboxylic reaction product present
contacted with the monomer/water solution is typically between
about 4 to about 30 parts of reaction product, more preferably
between about 15 to about 25 parts of reaction product per 100
parts by weight of monomer. The above constitutes what is believed
to be a novel polymer dispersion.
[0035] To convert the polymer dispersion into a
coating/impregnating composition, a water soluble or water
dispersible crosslinking agent is added to the dispersion after
polymerization of the monomers. Preferred crosslinking agents may
be selected from metal salts of the group comprising zinc,
aluminum, titanium, copper, chromium, iron, zirconium and lead and
may be exemplified by zirconium complexes as described for example
in GB1002103 and, according to one process, prepared by refluxing a
carboxylic acid containing 1-4 carbon atoms with a zirconyl
carbonate paste and then adding a carboxylic acid containing more
that 4 carbon atoms.
[0036] Water soluble inorganic metal compounds may also be used.
Ammonium zirconium carbonate is particularly preferred for
preparing compositions according to the invention.
[0037] The amount of crosslinking agent added typically ranges from
between about 0.5 to about 3.0 parts by mole of metal in the metal
crosslinking agent per mole of reaction product of the carboxylic
acid/amine surface active agent, with amounts ranging from about
1.0 to about 2.0 moles per mole of reaction product of carboxylic
acid/amine being more preferred.
[0038] In the embodiment where ammonia is selected for use in
combination with the carboxylic acid, the resulting ammonium fatty
acid salt may be directly used as an improved water resistance
coating composition without requiring the presence of the
crosslinking agent.
[0039] The dispersion medium may also include other performance
enhancing chemicals. Examples of such materials include, but are
not limited to, defoaming agents, waxes, additional surface active
agents, plasticizers such as polyethylene glycol, freeze thaw
stabilizers, pigments, colorants, dyes, and antibacterials.
[0040] In practice, to make the dispersion of the present
invention, a reactor precharge of the carboxylic acid/amine
reaction product in water is prepared. The carboxylic acid/amine
reaction product can either be prepared as described above and
added to water or prepared "in situ" by the addition of the
respective monomer reactants into the aqueous environment. The
reaction mixture is then heated to between about 50 to about
100.degree. C., more preferably between about 65 to about
90.degree. C., and most preferably between about 70 to about
85.degree. C. Once the reaction medium reaches this temperature, an
amount of monomer initiator in water is added to the medium.
[0041] The polymerization initiators are preferably selected from
free radical thermal initiators. The polymerization initiator may
take the form of many known initiators such as azo, peroxide,
persulfate and perester initiators and may be either water soluble
or monomer soluble. The amount of initiator added to the solution
typically ranges from between about 0.05 to about 2 parts per 100
parts monomer with amounts ranging from about 0.1 to about 1.0
parts being particularly preferred, amounts ranging from about 0.1
to about 0.5 parts being even more preferred and about 0.25 parts
being most preferred. The free radical initiator added is
preferably a water soluble initiator such as sodium or ammonium
persulfate.
[0042] Other initiators which can be selected include azo
(azobisnitrile) type initiators (water or oil soluble) such as
2,2'-azobis-isobutyronitri- le,
2,2'-azobis-(2-methylpropanenitrile),
2,2'-azobis-(2,4-dimethylpentane- nitrile),
2,2'-azobis-(2-methylbutanenitrile), 1,1'-azobis-(cyclohexanecar-
bonitrile), 2,2'-azobis-(2,4-dimethyl-4-methoxyvaleronitrile),
2,2'-azobis-(2,4-dimethylvaleronitrile) and
2,2'-azobis-(2-amidinopropane- ) hydrochloride.
[0043] Other free radical initiators which may be selected include
peroxide materials such as benzoyl peroxide, cumene hydroperoxide,
hydrogen peroxide, acetyl peroxide, lauroyl peroxide, and peresters
such as t-butylperoxypivalate, .alpha.-cumylperoxypivalate and
t-butylperoctoate.
[0044] After the monomer initiator has been added, the monomer(s)
are then added. The monomers are added to the reaction medium over
a period of time, typically between about 60 to about 300 minutes,
more preferably between about 120 to about 240 minutes and most
preferably between about 120 to about 180 minutes. Thereafter, the
reaction mixture is maintained at a reaction temperature for a
suitable period of time to effectuate polymerization of the
monomers. This time typically ranges from about 10 to about 60
minutes, more preferably between about 15 to about 45 minutes.
[0045] The reaction mixture is thereafter cooled. During the
cooling period additives used to terminate polymerization such as
oxidizers and reducing agents are added to the mixture. Examples of
suitable oxidizers include t-butyl hydroperoxide and examples of
suitable reducing agents include sodium metabisulfite.
[0046] The resulting polymer has an average polymer particle size
(Gaussian mean particle diameter) ranging from about 1 to about
2000 nanometers, more preferably less than about 200 nanometers and
most preferably less than about 100 nanometers. In particularly
preferred embodiments, the average preferred polymer particle size
is between about 1 and about 60 nanometers, more preferred between
about 5 and about 40 nanometers, still more preferred between about
10 and about 40 nanometers, and ideally between about 20 and about
40 nanometers. Production of small polymer particle sizes is
desirable as this allows for coating of the composition onto
substrates having microscopic voids.
[0047] In addition, the glass transition temperature of the polymer
can be selected depending on the monomers selected. In practice,
the glass transition temperature of the polymer is preferably less
than about 80.degree. C., more preferably between about -20.degree.
C. and about 40.degree. C. and most preferably between about
-10.degree. C. and about 25.degree. C.
[0048] The resulting product is filtered, and optionally diluted
with water to yield a polymer composition having a percentage
solids ranging between about 1 to about 40 percent by weight. To
this composition is added the crosslinking agent in amounts as
described above. In the preferred embodiment, the pH of the
resulting mixture is adjusted to basic conditions with a volatile
base. The addition of the base is performed to prevent the
crosslinking agent from, over time, prematurely reacting with the
carboxylic acid/amine reaction product. In practice the
crosslinking reaction will occur upon evaporation of the base once
the composition is coated onto a substrate. As long as the base is
present, the reaction is deferred until desired. Alternatively, the
base can be added first to the crosslinking agent and the resulting
material is thereafter added to the polymer dispersion. If long
term shelf life is not a desired property, the base need not be
included at all.
[0049] In the preferred embodiment, the pH of the resulting mixture
is between about 8-12, more preferably between about 8.5 to about
11 and most preferably between about 9 and about 10. The base that
is added is one which is considered volatile, i.e., one which will
evaporate upon application to a substrate. In preferred
embodiments, the base that is added is an inorganic or organic
amine such as ammonia (ammonium hydroxide), dimethylamine or
diethylamine.
[0050] The addition of the crosslinking agent to the polymer prior
to coating onto a substrate and crosslinking results in the
formation of a "one package" system. Alternatively, a "two package"
system could be utilized wherein the crosslinking agent/pH adjuster
is maintained in a separate container just until the time before
coating is to take place. While the one package system provides
benefits in terms of storage, the two package system can be
utilized when higher levels of solids are desired.
[0051] To use the coating composition of the present invention, it
is merely applied to a substrate and then allowed to dry.
Substrates which can be coated according to the present invention
include wood, paper, and other cellulosic materials, textiles,
masonry, cement, concrete, surface coatings, metals, brick, stone,
roofing materials, powders, inks, leather, textiles and adhesives.
In practice the coating composition in either one package or two
package form is applied by means known in the art such as a brush
or roller or by spray application. In the case of the two package
system, the different containers are mixed together prior to
coating. Using either the one package or two package system, the
volatile base then evaporates from the coating, enabling the
crosslinking agent to crosslink the carboxylic acid/amine
component. Typically, this crosslinking reaction time ranges from
about 5 to about 180 minutes. While the crosslinking reaction is
occurring, the polymeric material is able to penetrate into the
pores, or other microscopic voids of the substrate. Once the
crosslinking reaction has gone to completion, and all volatile
solvent is evaporated from the coating composition, what results is
the formation of a thin water resistant film onto the substrate. In
the embodiment where the composition comprises an ammonium fatty
acid salt dispersion, it may be directly applied onto a surface
without the need for the addition of a crosslinking agent.
[0052] As a result of its excellent water resistant properties, the
compositions of the present application can be used for the
following commercial applications: paints, stains, building lumber
protective coating, millwork protective coating, siding protective
coating, edge sealing compositions, wood fiber cement protective
coating, roof tile/panel protective coating and deck treatment
protective coating.
[0053] In addition to providing excellent water resistance, the
coating compositions of the present invention provide resistant
film coatings for extended periods of time, and are recoatable
(i.e., additional coatings can be coated onto the cured composition
of the present invention). They also provide excellent swell
efficiencies, with values exceeding 40, more preferably exceeding
50, and most preferably exceeding 60 being produced when evaluating
water resistance by using ASTM D4446 Swellometer Test.
[0054] The invention is described in greater detail by the
following non-limiting examples.
EXAMPLE 1
Production of AEPD Laurate
[0055] 1,276.8 parts of water are added to a 3 liter reaction
flask. 124.2 parts of 2-amino-2-ethyl-1,3-propane diol (AEPD ) (96%
solution in water) is added to the flask and stirred until
dissolved in the water. 200 parts of lauric acid are added to the
flask and the mixture is heated with stirring to between about 60
-70.degree. C. After 30 minutes and, if clear, the solution is
cooled and packaged.
EXAMPLE 2
Production of AEPD Palmitate
[0056] 1,881 parts of water are added to a 3 liter reaction flask.
124.2 parts AEPD (96% solution in water) is added to the flask and
stirred until dissolved in the water. 257 parts of palmitic acid
are added to the flask and the mixture is heated with stirring to
between about 60-70.degree. C. After 30 minutes and, if clear, the
solution is cooled and packaged.
EXAMPLE 3
Production of AEPD Laurate/stearate
[0057] 1,427 parts of water are added to a 3 liter reaction flask.
124.2 parts AEPD (96% solution in water) is added to the flask and
stirred until dissolved in the water. 100 parts lauric acid and 137
parts stearic acid are added to the flask and the mixture is heated
with stirring to between about 60-70.degree. C. After 30 minutes
and, if clear, the solution is cooled and packaged.
EXAMPLE 4
Production of AEPD Laurate/palmitate (Equimolar Mixture)
[0058] 1,391 parts of water is added to a 3 liter reaction flask.
124.2 parts of AEPD (96% solution in water) is added to the flask
and stirred until dissolved in the water. 100 parts of lauric acid
and 128.5 parts of palmitic acid are added to the flask and the
mixture is heated with stirring to between about 60-70.degree. C.
After 30 minutes and, if clear, the solution is cooled and
packaged.
EXAMPLE 5
Production of AEPD Laurate/palmitate (1:2 Molar Mixture)
[0059] 1,391 parts of water is added to a 3 liter reaction flask.
124.2 parts of AEPD (96% solution in water) is added to the flask
and stirred until dissolved in the water. 100 parts of lauric acid
and 255.0 parts of palmitic acid are added to the flask and the
mixture is heated with stirring to between about 60-70.degree. C.
After 30 minutes and, if clear, the solution is cooled and
packaged.
EXAMPLE 6
Production of AEPD Stearate
[0060] This composition is prepared in a similar manner to those
described above. However, A much larger amount of water is required
in order to completely solubilize the resulting material. The ratio
of AEPD to stearic acid in this case is 124.2 parts of AEPD to 275
parts stearic acid respectively.
EXAMPLE 7
Production of Polymer Dispersion using Surface Active Composition
of Example 2
[0061] 15 to 20 parts by weight of the Example 2 composition is
dissolved in 96.5 to 282 parts water. The resulting mixture is
heated to about 70 to about 85.degree. C. A monomer mix of 100
parts by weight of an equal amount of butyl acrylate (50.0 parts)
and methyl methacrylate (50.0 parts) is prepared. 0.25 parts of
sodium persulfate in 2 to 4 parts of water are added to the
reactor, followed by the feeding of the monomer mix to the reactor
over a two to three hour time period. After the monomers have been
fully added, the reaction mixture is held at 70 to about 85.degree.
C. for 15 to 45 minutes. The mixture is then cooled to 30.degree.
C., but during the cooling period, 0.05 parts of t-butyl
hydroperoxide and 0.03 parts of sodium metabisulfite in 4 to 6
parts of water are added. The material is then filtered through a
100 to 150 mesh filter. The resulting material has a total amount
of polymer solids ranging between about 25 to about 40 percent by
weight, has a pH ranging between about 7.7 and about 8.3, and has a
viscosity of about 15 to about 150 cps at a solids level of 32% as
measured on a Brookfield Viscometer, 60 rpm, Spindle #1. The
particle size of the dispersion is between 15 to 40 nanometers.
EXAMPLES 8-12
[0062] The procedure of Example 7 is repeated except that the
following materials in parts by weight are used as monomers and
surface active agents respectively:
1 2- Butyl Methyl Hydroxyethyl Example 2 Example 4 Example 5
Example Acrylate Methacrylate methacrylate Composition Composition
Composition 8 50 50 -- -- 15-20 -- 9 50 50 -- -- -- 15-20 10 49.7
48.3 2.0 15-20 -- -- 11 49.7 48.3 2.0 -- 15-20 -- 12 49.7 48.3 2.0
-- -- 15-20
EXAMPLE 13
Coating Composition Using Example 7 Composition
[0063] An aqueous solution of ammonium zirconium carbonate is added
to the Example 7 dispersion such that equimolar amounts of the
crosslinkable surface active agent and zirconium are present (the
amount of zirconium present in the ammonium zirconium carbonate
solution is approximately 7.3 percent by weight). Water is added to
yield a dispersion having a percentage of solids of about 10%.
Ammonium hydroxide (28%) is added to the dispersion to raise its pH
to about 9.5.
[0064] To determine the performance characteristics of the
resulting coating composition, it is applied by a brush onto a wood
surface, more specifically, a pine surface. The composition is then
allowed to cure as a result of evaporation of the ammonium
hydroxide, which enables the zirconium from the ammonium zirconium
carbonate to react with the crosslinkable surface active agent and
form a thin, crosslinked film. Curing is accomplished after about 5
to 180 minutes. Because of the particle size of the polymer present
in the dispersion, the polymer is able to penetrate into the small
pores or other openings of the wood surface to provide protective
properties.
[0065] The adhesion of a coating composition, such as a latex paint
to a wood surface having applied thereon the composition of the
present invention is tested by utilizing ASTM-D 3359-90; test
method A.fwdarw.X-cut tape test and test method B.fwdarw. cross cut
tape test. To the extent necessary for completion, the details of
the testing procedure are hereby incorporated by reference. A value
equal to or greater than 4A using the X-cut tape test and equal to
or greater than 3B using the cross cut tape test is evidence of
excellent adherence of a coating composition to a substrate.
(Testing is performed in triplicate to ensure uniformity.) The
composition of this example meets this criteria. This test
indicates that the compositions of the present invention are easily
recoatable.
[0066] The ASTM D4446 Swellometer test is used to determine the
ability of coating compositions to prevent wood from swelling. This
test measures the ability of a wood sample (coated) to resist
water. To the extent necessary for completion, the details of the
testing procedure are hereby incorporated by reference. For use as
a standard an untreated piece of wood is immersed in water and its
ability to swell (i.e., resist penetration by the water) is
measured. The same test is repeated with a similar piece coated
with the coating composition of this Example. The Swell Efficiency
of the coated composition is about 63. A water repellent efficiency
of 60 is required to "pass" the test.
[0067] Having described the invention in detail and by reference to
the preferred embodiments thereof, it will be apparent that
modifications and variations are possible without departing from
the scope of the appended claims.
* * * * *