U.S. patent application number 13/323599 was filed with the patent office on 2012-06-14 for masking solutions comprising siloxane-based surfactants for using in painting operations.
This patent application is currently assigned to Cal-West Specialty Coatings, Inc.. Invention is credited to Robert Louis Mesa, Edward W. Woodhall.
Application Number | 20120148747 13/323599 |
Document ID | / |
Family ID | 46327200 |
Filed Date | 2012-06-14 |
United States Patent
Application |
20120148747 |
Kind Code |
A1 |
Woodhall; Edward W. ; et
al. |
June 14, 2012 |
MASKING SOLUTIONS COMPRISING SILOXANE-BASED SURFACTANTS FOR USING
IN PAINTING OPERATIONS
Abstract
This invention provides a masking material that can be used to
protect an underling surface (e.g. an automobile surface) during an
overcoating (e.g. painting) operation. The masking material in one
embodiment includes a thickener and a pH control agent and water.
The masking material can be applied to a surface that is to be
protected from paint overspray or other coating processes, allowed
to dry, and the surface then coated (e.g. with paint). After drying
of the paint, or other coating, the masking material can removed by
water washing.
Inventors: |
Woodhall; Edward W.; (Los
Altos, CA) ; Mesa; Robert Louis; (Santa Clara,
CA) |
Assignee: |
Cal-West Specialty Coatings,
Inc.
Sunnyvale
CA
|
Family ID: |
46327200 |
Appl. No.: |
13/323599 |
Filed: |
December 12, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11671354 |
Feb 5, 2007 |
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13323599 |
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11149785 |
Jun 9, 2005 |
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11671354 |
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60771085 |
Feb 6, 2006 |
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60579851 |
Jun 14, 2004 |
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Current U.S.
Class: |
427/259 |
Current CPC
Class: |
C09D 7/43 20180101; C09D
5/20 20130101; B05D 1/02 20130101; B05D 7/02 20130101; B05D 2202/00
20130101; B05D 1/327 20130101; B05B 16/00 20180201; Y10T 428/31663
20150401; C09D 7/45 20180101; B05D 7/14 20130101; B65D 85/70
20130101; B65D 85/00 20130101; B05D 7/54 20130101; C09D 5/008
20130101; C04B 41/4592 20130101; C09D 129/04 20130101 |
Class at
Publication: |
427/259 |
International
Class: |
B05D 1/32 20060101
B05D001/32 |
Claims
1. A method of temporarily protecting a surface in a coating
operation, said method comprising: a) applying a masking material
to said surface, said applying resulting in a dry, substantially
continuous film of said masking material, said masking material,
before drying, comprising an aqueous mixture of: i) a film former
present in an amount ranging from about 0.15 to about 25 weight
percent active ingredient; ii) a siloxane-based surfactant in a
concentration sufficient to allow said masking material to wet said
surface; and iii) a non-siloxane surfactant; wherein said masking
material has a shelf life at room temperature greater than about 1
year; b) coating all or a portion of said surface with an
overcoating compound, said masking material preventing said coating
compound from contacting said surface; and c) removing said masking
material from said surface whereby the coating compound applied to
the surface covered with the masking material is removed together
with the masking material.
2. The method of claim 1, wherein said masking material has a shelf
life greater than two years.
3. The method of claim 1, wherein said film former is an aliphatic
polyol.
4. The method of claim 1, wherein said film former is a polyvinyl
alcohol.
5. The method of claim 4, wherein said film former ranges from
about 1% to about 25% weight percent of said masking material.
6. The method of claim 4, wherein said film former ranges from
about 3% to about 10% weight percent of said masking material.
7. The method of claim 1, wherein said non-siloxane surfactant
comprises an alcohol ethoxylate.
8. The method of claim 7, wherein said non-siloxane surfactant
comprises an oleyl alcohol ethoxylate.
9. The method of claim 1, wherein said masking material further
comprises a thickener.
10. The method of claim 9, wherein said thickener is a xanthan gum
thickener.
11. The method of claim 9, wherein said thickener ranges from about
0.1 to about 1% weight percent active ingredient.
12. The method of claim 9, wherein said thickener is present at
about 0.4% weight percent.
13. The method of claim 1 any of claim 1 or 9, wherein said masking
material further comprises a plasticizer or humectant.
14. The method of claim 13, wherein said plasticizer is a simple
sugar.
15. The method of claim 13, wherein said plasticizer is selected
from the group consisting of glucose, sucrose, and fructose.
16. The method of claim 13, wherein said plasticizer is selected
from the group consisting of sorbitol, glycerin, sucrose, urea,
polyethylene glycol, polypropylene glycol, polyglycerol, and
glycerol.
17. The method of claim 16, wherein said plasticizer is present in
an amount ranging from about 0.2 to about 12 weight percent of said
masking material.
18. The method of claim 1 any of claim 1 or 9, wherein said masking
material further comprises a non-ionic surfactant.
19. The method of claim 18, wherein said non-ionic surfactant is an
alcohol ethoxylate.
20. The method of claim 18, wherein said non-ionic surfactant is a
tridecyl alcohol ethoxylate.
21. The method of claim 18, wherein said non-ionic surfactant is
present in an amount ranging from about 0.01% to about 3% weight
percent of said masking material.
22. The method of claim 1, wherein said masking material further
comprises a pH adjuster.
23. The method of claim 22, wherein said pH adjuster adjusts the pH
of said composition to a basic pH.
24. The method of claim 22, wherein said pH adjuster adjusts the pH
of said composition to about pH 9.5.
25. The method of claim 22, wherein said pH adjuster comprises a
base selected from the group consisting of sodium hydroxide,
potassium hydroxide, magnesium hydroxide, an amine, and sodium
bicarbonate.
26. The method of claim 1, wherein said masking material further
comprises a colorant and/or a biocide.
27. The method of claim 1, wherein: said film former is a polyvinyl
alcohol (PVA); and said non-siloxane surfactant comprises an
alcohol ethoxylate.
28. The method of claim 27, wherein said non-siloxane surfactant
comprises a tridecyl alcohol ethoxylate.
29. The method of claim 1, wherein: said film former is a polyvinyl
alcohol (PVA); said masking material further comprises a thickener;
said masking material further comprises a humectant; said masking
material further comprises a pH adjuster; and said masking material
further comprises a non-siloxane surfactant.
30. The method of claim 29, wherein said masking material further
comprises: a biocide; and a colorant.
31. The method of claim 29, wherein: said film former is present at
about 5% weight percent of said masking material; said thickener is
present at about 0.4% weight percent of said masking material; said
humectant is present at about 0.75% weight percent of said masking
material; and said pH adjuster is a base[[;]].
32. The method of claim 1, wherein said overcoating compound is
paint.
33. The method of claim 1, wherein said surface is a surface of a
vehicle.
34. The method of claim 1, wherein said surface is a surface of an
automobile.
35. The method of claim 1, wherein said surface comprises a painted
surface of a vehicle.
36. The method of claim 1, wherein said surface comprises a painted
surface of an automobile.
37. The method of claim 1, wherein said surface comprises a bumper
or trim of a vehicle.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of U.S. Ser. No.
11/671,354, filed on Feb. 5, 2007, which claims benefit of and
priority to U.S. Ser. No. 60/771,085, filed on Feb. 6, 2006. U.S.
Ser. No. 11/671,354 is also a continuation-in-part of U.S. Ser. No.
11/149,785, filed on Jun. 9, 2005, which claims benefit of and
priority to U.S. Ser. No. 60/579,851, filed on Jun. 14, 2004, all
of which are herein incorporated by reference in their entirety for
all purposes.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH AND DEVELOPMENT
[0002] [Not Applicable ]
FIELD OF THE INVENTION
[0003] The present invention relates to the field of protective
coatings to be used during coating operations of various surfaces
including surfaces of vehicles or buildings. In certain embodiments
the invention provides an improved method and composition for
masking selected portions of a surface, in particular a painted
vehicle surface, from paint or other overcoating materials.
BACKGROUND OF THE INVENTION
[0004] It is well known that painting, or other overcoating
operations often require masking of certain portions of the surface
of the object to be painted to prevent overspray by the coating
material (e.g. paint). For example, it is often necessary to mask
trim, and/or windows, and/or certain already painted areas on a
vehicle (e.g., a motor vehicle) or a component of a vehicle (e.g. a
door, a bumper, a frame, etc.) from paint overspray.
[0005] Similarly, when painting building components (e.g. window
frames) it is often desirable to protect certain areas (e.g. the
glass windows) of the building components from paint overspray.
[0006] On occasion, it is necessary to mask painted portions of a
vehicle or building from paints of a different color and overspray
of paints of the same color. In addition, it is often desired to
protect the surfaces (e.g. floors or walls) of the area (e.g. paint
spray booth) in which the overcoating (e.g. painting) operation is
performed.
[0007] In practice, masking operations are often one of the most
time consuming and, therefore, expensive parts of the
painting/overcoating process. In spite of attempts to develop
suitable chemical masks for vehicle painting, vehicle painters
continue to use primarily masking tape and paper to cover portions
of a vehicle where paint is not desired. To mask the trim on a car,
for example, will often require many hours of tedious labor.
Furthermore, even when done carefully, defects in such paint masks
allow paint to contact surfaces that are desired to be
protected.
[0008] Chemical masking solutions have been proposed to the problem
of protecting surfaces during coating processing operations.
However, such techniques have often not found extensive use. Some
of the proposed chemical masks have been unsuitable for application
to portions of a vehicle or building because of damage that could
potentially occur to the protected portions of the vehicle or
building. Other compositions are not water-soluble which increases
the difficulty and expense of removal. In addition, masks that
require solvents for removal are problematic in view of the
increasing regulation of disposal of solvents as environmental
regulation becomes stricter with time. Other compositions are
difficult to apply, difficult to remove, excessively costly, or the
like.
[0009] From the above it is seen that an improved masking that is
easily applied and removed, that provides good surface protection,
that is economical, and whose use entails little or no
environmental impact is needed.
SUMMARY OF THE INVENTION
[0010] The present invention provides improved methods and
compositions for protecting a s vehicle (e.g. motor vehicle) or
other surface subject to a coating operation such as painting, or
for protecting a surface of an article manufacture during an
assembly operation. In certain embodiments, the compositions
comprise a thickener and a pH control agent.
Definitions
[0011] The term "aqueous solution" need not require the components
comprising the solution actually be in solution phase (i.e. fully
dissolved in water). The term "aqueous solution" thus includes
aqueous mixtures, aqueous suspensions, aqueous dispersions, and the
like.
[0012] The terms "masking material" and "masking composition" are
used interchangeably to refer to a composition that can be applied
to a surface to protect that surface from overcoating (e.g. with
paint) and then subsequently removed from that surface (e.g., by
washing/rinsing with water).
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [Not Applicable ]
DETAILED DESCRIPTION
[0014] The present invention provides improved methods and
compositions for protecting a vehicle (e.g. a motor vehicle) or
other surface subject to a coating operation such as painting. The
compositions described herein are particularly well suited for use
on painted automobile surfaces. They provide effective protection
of such surfaces from overspray during coating operations (e.g.
painting operations), are easily removed, e.g. by a water wash,
have extremely low VOCs, and do not damage or in any way mar the
underlying surface.
[0015] For example, in one embodiment, certain regions of an
automobile, or other surface, may be masked using the masking
compositions of the present invention to protect those regions from
paint overspray in a painting booth. In another embodiment, an
article of manufacture (e.g. an automobile panel) may be protected
from mechanical impact and/or abrasion by the presence of such an
overcoating.
[0016] In addition it is also often desired to protect the surfaces
of the area in which an overcoating operation (e.g. painting) is
performed. In particular, it is desired to protect the walls,
floors and other surfaces of such an area (e.g., a painting booth)
from paint overspray and spills. In addition, it is also desirable
to reduce airborne dust in such areas during overcoating
operations.
[0017] This invention provides compositions and methods to meet
these needs. In preferred embodiments, the methods entail coating
the surface to be protected (e.g., a surface of a car or truck or
the walls and/or floors of a spray booth) with a temporary
protective masking composition as described herein. One or more
coating (e.g. painting) operations, and/or mechanical/handling
operations are performed and, when desired, the protective
composition is removed (e.g., by a simple water wash).
[0018] The masking compositions of this invention, when applied to
a surface (e.g. a painted of an automobile), typically produce a
substantially continuous dry film that adheres well to the
underlying surface. By "substantially continuous film" it is
intended to mean herein a film generally lacking pinholes through
which, oil, paint, dust, or other materials can reach the
underlying surface. Further, the material can be removed easily
from the surface to be protected after use with a water wash, or by
mechanical means such as brushing, or peeling, or by combinations
of these methods. In addition, because the material is
biodegradable, it may be simply disposed of (e.g., washed down a
sewer) with no substantial environmental impact.
[0019] When formulated as described herein, the masking
compositions provide effective protection of an underlying surface
against paint spray, mechanical insult, and the like. It was
surprising discovery that, when formulated as described herein,
siloxane surfactants can be effectively used to improve the wetting
properties of the masking composition (particularly on painted
surfaces of automobiles) without interfering with the painting, or
other overcoating, operation, and without marring or otherwise
damaging the underlying surface. Indeed, it was a surprising
discovery that the coatings described herein are fully compatible
with painted automobile surfaces.
[0020] One preferred method of protecting surfaces according to
this invention includes steps of applying the masking compositions
to the surface to be protected in a substantially continuous film.
The compositions are then dried to form a coating that protects the
underlying surface from the coating operation (e.g., paint
overspray). The coating can then be subsequently removed from the
surface by simply washing with water when it is longer required. In
one particularly preferred embodiment, the coatings of the present
invention are used to protect components of motor vehicles (e.g.,
automobiles or automobile surface finishes), and the walls and
floors of spray booths or other areas or structures that may be
contacted with overspray in a coating (e.g., painting)
operation.
[0021] In certain preferred embodiments, the masking compositions
comprise an aqueous solution of a film former and a siloxane-based
surfactant, and optionally, a pH control agent (pH adjuster). The
compositions can additionally include one or more additional
components, including, but not limited to, cyclodextrin(s),
additional surfactant(s) (e.g., non-ionic surfactants), alcohol(s),
corrosion inhibitor(s), plasticizer(s), defoamer(s), biocides,
dyes/colorants, and the like, as described herein. Various
components and ranges for illustrative formulations are shown in
the Examples.
[0022] The aqueous masking compositions are formulated by simple
mixing of the various components. It is noted, that when a
component is referred to as "X weight percent active ingredient of
a masking composition" this is referred to as the weight percent of
the active ingredient of the component in the "final" masking
composition before drying. Thus, for example a commercial
formulation of the thickener EP-1 consists of about 30 weight
percent active ingredient. When the masking composition comprises 4
weight percent of this formulation, the final active ingredient
weight percent is 1.2 weight percent (0.3.times.0.04=0.012).
I. Film Former.
[0023] The masking compositions of this invention tyhpically
utilize a film former to form a dry substantially continusous film
on the surface that is to be protected during an overcoating
operation. The film former is selected to be resistant to
penetration by the overcoating material (e.g. paint), to be easily
removed (e.g., by a water wash), to be compatible with the
underlying surface (e.g., a painted automobile surface), and
preferably to have low VOCs. In certain embodiments, the film
former comprises an aliphatic polyol such as polyvinyl alcohol.
Polyvinyl alcohols are well known to those of skill in the art and
include, for example, DuPont Corporation's ELVANOL.TM. 5105 having
a molecular weight of about 15,000 to about 27,000 daltons, DuPont
Corporation's ELVANOL.TM. 5042 having a molecular weight of about
70,000 to 100,000 daltons, CELVOL.TM. polyvinyl alcohols (from
Celanese Chemicals, Inc.), and the like. In certain embodiments,
the aliphatic polyol component can include two or more different
polyols having different molecular weight ranges. For example,
DuPont Corporation's ELVANOL.TM. 5105 (15,000 to 27,000 daltons)
and ELVANOL.TM. 5042 (70,000 to 100,000 daltons) can be used
together in some formulations. In certain embodiments, the
polyvinyl alcohol is CELVOL.TM. 205.
[0024] In certain embodiments, other film formers are contemplated
in addition to, or as an alternative to polyvinyl alcohols. Such
film formers include, but are not limited to starch, cellulose,
carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl
cellulose, algin, dextrin, gum Arabic, alginic acid, a cellulose
gum, and the like.
[0025] The film former(s) typically comprise from about 1% to about
50% (weight percent of the liquid masking material), preferably
from about 3% to bout 25%, more preferably from about 5% to about
15% or 20%, and most probably from about 7% or 10% to about 12% or
15%. In certain embodiments, the film former comprises about 11%
(weight percent active ingredient) of the liquid masking
material.
[0026] In certain embodiments, the film former(s) can optionally,
additionally comprise one or more thickeners. Thickeners, in
particular thixotropic (shear-thinning) thickeners, can act as film
formers and, when used as such, are capable of preventing
penetration of a coating material (e.g. paint) to an underlying
surface (e.g. the surface as a vehicle.
[0027] Suitable thickeners include, but are not limited to
neutralized crosslinked acrylate copolymers, neutralized
crosslinked polyacrylic acids, neutralized polyacrylic acids,
algins, carboxymethylcellulose, neutralized polymethacrylic acids,
neutralized ethylene-acrylic acid copolymers, methocel, gum arabic,
cellulose gum, neutralized styrene acrylic acid copolymers, and
combinations thereof
[0028] In certain preferred embodiments, the thickeners include
B.F. Goodrich EP-1.TM., and/or B.F. Goodrich Albucril ESP.
[0029] If present, the thickener typically comprises from about 0.5
to about 10 weight percent, preferably from about 1 to about 5
weight percent, more preferably from about 1 to about 3 weight
percent, and in some embodiments about 1.2 weight percent active
ingredient of the aqueous masking material.
II. Siloxane-Based Surfactant.
[0030] The coating compositions of this invention additionally
include a siloxane-based (silicone) surfactant. It was a surprising
discovery that silicon surfactants, especially polysiloxane
surfactants for aqueous systems are highly compatible with the
masking compositions of this invention, permit effective wetting of
an underlying surface (even a painted surface of an automobile) and
yet, contrary to prevailing belief, do not damage the underlying
painted surface or the applied overcoating material(s).
[0031] It was also a surprising discovery that the siloxane
formulations disclosed herein, particularly when used in
combination with a surfactant/disbursant (e.g., an oleyl alcohol
ethoxylate (such as, for example Rhodasurf.TM.)), have a shelf life
at room temperature (e.g. 65-70.degree. F.) of one year or more,
preferably of at least two years, more preferably of at least 3
years, and most preferably of at least 4 or 5, or even 8 or 10
years.
[0032] Suitable siloxane-based surfactants include silicon
surfactants compatible with aqueous systems. Such surfactants
include, but are not limited to silicone polyoxyalkylene
copolymers, organosilicone-polyether copolymer surfactants, and the
like. In certain embodiments, preferred siloxane-based surfactants
include BYK.RTM. surfactants available from BYK Chemie GmbH (West
Germany). In certain preferred embodiments, the siloxane based
surfactants include BYK.RTM. 347. Other silicon surfactants can be
identified for example in Hill (1999) Silicon Surfactants, Marcel
Decker, New York.
[0033] The siloxane(s) are preferably present in an amount
sufficient to allow the masking material to wet the underlying
surface and to form a substantially continuous film. In certain
embodiments, the siloxane(s) range from about 0.01% to about 1%,
preferably from about 0.05% to about 0.5%, and most preferably from
about 0.2% to about 0.4%/weight percent of the aqueous masking
material.
III. Cyclodextrin.
[0034] In certain embodiments, the masking materials additionally
includes one or more water-soluble cyclodextrins. Without being
bound by a particular theory, it is believed the cyclodextrin(s)
encapsulate the siloxane and thereby enhance the stability and
increase the shelf-life of the masking material.
[0035] When present, the cyclodextrins typically comprises about
0.01 to about 20 weight percent of the masking composition,
preferably about 0.1 to about 5 or 10 of the of the masking
composition, post preferably from about 0.1 to about 1 weight
percent of the masking composition. In certain embodiments, the
cyclodextrin comprises about 0.2 weight percent of the masking
composition.
[0036] Cyclodextrins are well known to those of skill in the art
and are commercially available. Suitable cyclodextrins include, but
are not limited to alpha-, beta-, gamma-cyclodextrins, and various
modified cyclodextrins, with alpha-cyclodextrins being preferred.
Suitable cyclodextrins include, but are not limited to CAVITRON.TM.
8000, CAVITRON.TM. 8200, and the like (see, e.g., Cargill,
USA).
IV. Defoamer.
[0037] In certain embodiments, the masking materials of this
invention additionally includes one or more defoamers. The
defoamer(s) break bubbles, and prevent bubble patterns that would
otherwise appear in the coating from transferring to the underlying
(e.g., painted) surface. In addition defoaners facilitate the
loading of pressurized aerosol spray cans, pump sprayers or any
other container in which the coating composition is to be stored
and/or transported. Foam reduction allows more complete filling of
the receptacle with the coating composition and reduces time spent
waiting for foam to diminish during loading operations.
[0038] Preferred defoamers are compatible with aqueous systems and
typically include a primary antifoam agent such as a hydrophobic
silica, fatty amide, hydrocarbon wax, fatty acid, or fatty ester.
Certain preferred defoamers can include, but are not limited to,
combined surfactant-defoamers. Various defoamers include, but are
not limited to FOAMASTER.RTM., FOAMMAKER.RTM., BUBBLE BREAKER.RTM.,
and 1 and 2 octanol.
[0039] In various preferred embodiments the defoamer is a
silicon-based defoamer (e.g., BYK.RTM.-024 from BYK Chemie GmbH
(West Germany)).
[0040] In a preferred embodiment, the defoamer when present ranges
up to about 5%, preferably from about 0.001% to about 2%, more
preferably from about 0.001% to about 1%, and most preferably about
0.3% about 0.3%, by weight, of the aquesous masking material. In
one embodiment, the defoamer is present at about 0.05%, by weight,
of the masking material.
V. Additional Surfactant.
[0041] To provide a continuous and level film, the masking
composition preferably adequately wets the surface to be protected.
However, many surfaces, in particular, car body finishes, are
themselves highly hydrophobic or purposely treated (e.g. waxed) to
have a low surface free energy so that water will bead.
[0042] In a number of embodiments, an additional surfactant (in
addition to the siloxane) is not required, particularly where the
surface to be protected/masked is clean/pristine. Where the
underlying surface is less clean/pristine, however, effective
masking can be facilitated by the incorporation of one or more
additional surfactants into the masking composition.
[0043] Suitable surfactants include, but are not limited to anionic
surfactants (e.g., alkyl sulfates (e.g. RHODAPON.TM.), ether
sulfates (e.g., RHODAPEX.TM.), sulfonates (e.g. RHODACAL.TM.),
dodecylbenzene sulfonates, alpha-olefin sulfonates, diphenyl oxide
disulfonates, phosphate esters (e.g. Rhodafac.TM.), carboxylates
(e.g. Miranate.TM.), etc.), cationic surfactants (e.g.,
imidazolines (e.g. Miramine.TM.), ethoxylated amines (e.g.
Rhodameen.TM., etc.), non-ionic surfactants (e.g., nonylphenol
ethoxylates (e.g. Igepal CO series), octylphenol ethoxylates (e.g.
Igepal CA series), nonionic esthers (e.g. Alkamuls.TM.), oleyl
alcohol ethoxylates (e.g. Rhodasurf.TM.), ethoxylated mercaptans
(e.g. Alcodet.TM.), capped ethoxylates (e.g. Antarox.TM.), blocked
polymers, etc.), and amphoteric surfactants (e.g., imidazoline
derivatives (Miranol.TM.), fatty amine derivatives (e.g.,
Mirataine.TM.), etc.). In certain preferred embodiments, the
masking composition includes nonionic alkyl aryl surfactants such
as Triton CF-10 and CF-12 (Rohm & Haas, Philadelphia, Pa.,
U.S.A.). Also suitable is Triton X-100 and surfactants having
fluorinated alkyl chains such as "Fluorad" products sold by
Minnesota Mining and Manufacturing (St. Paul, Minn., U.S.A.) and
"Zonyl" products sold by DuPont Company (Wilmington, Delaware,
U.S.A.) are also suitable. In addition, many embodiments include
polyethoxy adducts or modified (poly)ethoxylates such as Triton
DF-12 and DF-16 sold by Union Carbide (Danbury, Conn., U.S.A.).
Other surfactants include nonylphenoxypolyethanol (such as IGEPAL
CO-660 made by GAF), polyoxyalkylene glycol (such as Macol 18 and
19 made by Mazer Chemicals), acetylenic diol-based surfactants
(such as Surfynol 104Amade by Air Products), and the like.
[0044] One role the surfactant in the masking composition is
facilitate wetting of the substrate (the underlying surface) by the
masking composition thereby leading to the formation of a
continuous film. In certain embodiments, a sufficiently continuous
protective film could be obtained with little or no surfactant so
long as underlying surface is sufficiently clean and/or the masking
composition contains a very high solids content (e.g., high
concentrations of thickener). Films containing high solids
concentrations are often highly viscous and therefore difficult to
apply, especially by spraying. The use of surfactants or other
wetting agents is preferred as coatings containing surfactants show
superior film-forming properties in a variety of application
methods even where solids content is quite low.
[0045] In certain embodiments, the wetting properties of the
masking compositions may be improved by adding certain surfactant
compositions, and/or by adding various water soluble alcohols such
as propanol, methanol, or isopropyl alcohol, or by adding aliphatic
polyols such as water soluble alcohols up to octanol. In
particularly preferred embodiments, surfactants are used in the
masking compositions of the present invention.
[0046] Certain preferred surfactants for use in the masking
compositions of the present invention should reduce the surface
tension of the masking composition to a sufficiently low value that
a level film, free of pinholes, is laid down. In certain
embodiments, the surfactant will reduce the surface tension of the
masking composition to at most about 25 dynes per centimeter, and
more preferably to at most about 20 dyne/cm. To avoid formation of
pinholes, the surfactant should not foam.
[0047] In addition, surfactants are preferably selected that work
with a variety of surfaces such as those containing silicones,
acrylic waxes, TEFLON.RTM. waxes, clear coats, natural and
hydrocarbon waxes, etc. Still further preferred surfactants will be
relatively inexpensive, will provide a product that does not spot,
streak, or frame (i.e., evaporate faster at edges such as molding
and/or trim) on the surface to be protected. Finally, the
surfactant is preferably water soluble and otherwise compatible
with the other components of the masking composition so that the
composition does not separate and leave pinholes when dry.
[0048] Because many surfaces to be protected will have unusually
low surface free energies, in many embodiments, surfactans are
selected that are able to dramatically lower the surface and
interfacial tensions of the masking composition. Compositions
having very low surface tensions also tend to produce many fewer
pinholes in the coating. Thus, any of the known classes of very low
surface tension surfactants are preferred for use in certain
embodiments of this invention.
[0049] One such class is the alkoxylates of fluorinated alkyl
chains. Other functional derivatives (e.g., esters, sulfonates,
carboxylates, ammonium compounds, etc.) of fluorinated alkyl chains
also tend to produce low surface tension aqueous solutions. In
general, replacement of hydrogens on an alkyl group by fluorine
atoms leads to surfactants of unusually low surface tension. The
above mentioned "Fluorads" and "Zonyls" are examples of surfactants
having fluorinated alkyl chains.
[0050] One such surfactant comprises about 0.06% FLUORAD.TM. FC
171, about 0.04% Fluorad FC 430 and about 1.0% TRITON.TM. DF-16 or
ACRYSOL.TM. 75. Another preferred formulation comprises about 0.5%
sulfonated surfactant (BIOSOFT.TM. N-300) about 0.03% Fluorad FC
171 and about 0.02% FLUORAD.TM. FC 430. In still another
particularly preferred embodiment for use on painted automobile
surfaces, the surfactant is a combination of a sulfonated
surfactant (e.g. Stephan BIOSOFT.TM. N300) and a non-ionic
surfactant (e.g. an oleyl alcohol ethoxylate e.g.,
RHODASURF.TM.DA630).
[0051] It has been discovered that a in certain particularly
preferred embodiments the surfactants include one or more non-ionic
surfactants. Certain preferred surfactants include alcohol
ethoxylates (e.g. TOMADOL.TM. 91-6. On preferred surfactant
includes TOMADOL.TM. 91-6 and TRITON.TM. DF-16. In one preferred
embodiment, the additional surfactant is DYNOL.TM. 604, a low foam
non-ionic surfactant.
[0052] The surfactant is typically present in an amount effective
to produce a coating that lays out smoothly in a substantially
continuous film of the painted surface of an automobile. In certain
embodiments, preferred masking compositions include up to 5 percent
surfactant, preferably up to about 3 percent surfactant, still more
preferably up to about 1 percent surfactant and most preferably up
to about 0.5 or 0.3 percent surfactant.
VI. Plasticizer
[0053] In various embodiments, the masking materials of this
invention additionally include one or more plasticizers to provide
toughness and flexibility and in particular to prevent cracking of
the film during drying and subsequent handling. Suitable
plasticizers are well known to those of skill in the art and
include, but are not limited to glycerine, sorbitol, sugars (e.g.
glucose, sucrose, levulose, dextrose, etc.), urea, triethylene
glycol, polyethylene glycol, and other water soluble plasticizers.
These plasticizers may be used alone, or in combination with each
other. One preferred combination of plasticizers is urea in
combination with glycerine or glycerine derivatives such as
glycerine monostearate or glycerine monooleate. Another
particularly preferred combination is glycerin in combination with
sorbitol.
[0054] In certain embodiments, Sorbitol, urea and glycerine are
most preferred as plasticizers. When expressed as a percentage of
the total coating compositions, the coatings utilizing urea as a
plasticizer preferably include about 4 percent to about 12 percent
urea, more preferably about 6 percent to about 12 percent urea and
most preferably about 7 percent to about 12 percent urea, while the
coatings utilizing glycerine and/or sorbitol as plasticizer
preferably include about 0.8 percent to about 30 percent glycerine
and/or sorbitol, more preferably about 4 to about 16 percent
glycerine and/or sorbitol, and most preferably about 5 to about 10%
glycerine and/or sorbitol.
[0055] In order to prevent cracking, the coatings of the present
invention that are force dried can require a higher plasticizer
concentration than the coatings that are simply air dried. Thus,
coatings that are simply air-dried may contain plasticizer in
concentrations near the lower end of the ranges provided above.
Thus, the air-dried coatings contain about 4 percent (10 percent,
by weight, of the dextrin) urea or 0.8 percent (2 percent, by
weight, of the dextrin) glycerine. Conversely, force dried coatings
preferably contain higher concentrations of plasticizer. Thus, the
force-dried coatings may contain about 7.2 percent (18 percent, by
weight, of the dextrin) urea or about 2 percent (5 percent, by
weight, of the dextrin) glycerine. Of course, coatings containing
the higher amounts of plasticizer may be air dried as well. In
addition, coatings containing the lower amount of plasticizer may
often be successfully force-dried.
VII. pH Control.
[0056] In certain embodiments, the masking compositions of this
invention additionally, and optionally include a pH control.
Suitable pH controls include essentially any material that can be
used to adjust the pH of the masking composition without damaging
the surface that the masking composition is applied to. The pH
control can be provided as a buffer, and/or as a strong or weak
acid, and/or as a strong or weak base.
[0057] In certain preferred embodiments the pH control is a basic
pH control and is used to adjust the pH of the masking composition
a range from about pH 7 to about pH 9.8, preferably from about pH
7.5 to about pH 9.5, more preferably from about pH 8.5 to about pH
9.5. In certain embodiments, the pH is adjusted to pH 9.5.
[0058] In certain embodiments, the pH control agent comprises one
or more bases including, but not limited to, sodium hydroxide,
potassium hydroxide, magnesium hydroxide, an amine, and sodium
bicarbonate.
VIII. Flash Corrosion Inhibitor.
[0059] The masking compositions of this invention can optionally
include one or more "flash corrosion inhibitors" ("flash rust
inhibitors). Flash corrosion inhibitors compatible with aqueous
systems are well known to those of skill in the art. Such
inhibitors include, but are not limited to ammonium benzoate, ADD
APT.RTM. Ferrocor flash corrosion inhibitor, M-435, M-240, alkyl
alkanolamines (e.g., MORLEX.TM.), and the like. In certain
embodiments, the flash corrosion inhibitor comprises ammonium
benzoate.
[0060] When present, the flash corrosion inhibitor typically ranges
from about 0 to about 0.5 weight percent, preferably from about 0.1
weight percent to about 0.2 weight percent active ingredient in the
masking composition.
IX. Preservative/Biocide.
[0061] The constituents of the masking compositions of this
invention can, in certain instances, support the growth of
microorganisms such as microbes, fungi, and the like. Thus, in
certain embodiments, to increase storage life, it is desired to
include a preservative. The term "preservative", as used herein, is
intended to designate a substance showing antimicrobial properties,
in particular bactericidal properties and preferably also
antifungal properties. Preservatives are well known to those of
skill in the art and include, but are not limited to anti-bacterial
agents, anti-fungal agents, bacteriostatic agents, fungistatic
agents, and enzyme inhibitors. Suitable preservatives include, but
are not limited to benzoic acid, sorbic acid or the salts thereof,
thimerosal (or merthiolate), phenyl mercuric acetate, phenyl
mercuric nitrate, detergents (e.g., benzalkonium chloride), and
sodium azide. Preferred preservatives are relatively or completely
non-toxic to higher animals (e.g., mammals) and, thus,
preservatives commonly used in foodstuffs and medical products are
suitable. Such preservatives include, but are not limited to ethyl
alcohol, chlorhexidine gluconate, sorbic and benzoic acid and their
salts, and the like. Other preferred preservatives include
KATHON.TM. LX (Rohm Haas, Inc.) and BTC 2125 (Stephan Chemical Co.,
Inc.).
[0062] The preservatives, when present, typically range from about
0 weight percent up to about 0.2 weight percent, preferably from
about 0.01 weight percent, up to about 0.005 weight percent.
X. Dye/Coloring Agent.
[0063] The composition can additionally include dyes or color
agents, scents, and the like. In certain embodiments that dyes
range from about 0 weight percent up to about 0.05 weight percent,
preferably from about 0.001 to about 0.02 weight percent active
ingredient in the masking composition. In certain embodiments, the
color agent (colorant) is Azo Rubin present at about 0.0015 weight
percent of the masking material.
XI. Viscosity Control.
[0064] The masking compositions of this invention can optionally
include one or more viscosity control agents. The viscosity control
agents are typically selected to adjust the viscosity for
particular application methods (e.g. brushing, doctor bar,
spraying, etc.). Viscosity control agents are well known to those
of skill in the art.
[0065] In certain embodiments, salts provide effective viscosity
control agents and can effectively be used to "thin" the thickeners
used in the compositions of this invention.
[0066] Suitable salts include, but are not limited to, sulfates
(e.g. sodium sulfate, potassium sulfate, etc.), chlorides (e.g.
sodium chloride, potassium chloride), bromides (e.g. sodium
bromide, potassium bromide), and the like. In certain embodiments,
the salt is sodium sulfate.
[0067] When present the salt typically ranges from about 0 to about
2 weight percent, preferably from about 0.1 to about 1 weight
percent, and more preferably from about 0.1 to about 0.5 weight
percent active ingredient of the masking composition.
XII. Humectant.
[0068] The masking compositions of this invention can optionally
include one or humectants. Humectants are well known to those of
skill in the art. Certain preferred humectants include glycols
(e.g. polyethylene glycol 400), and the like.
[0069] Certain other humectants provide more environmentally
friendly alternatives to traditional humectants. Thus, for example,
humectant GRB2 is an 80% aqueous solution of a non-ionic dispersant
mixed with low molecular weight polyols, which is supplied as a
straw colored liquid and contains minimal VOCs.
[0070] When present, a humectant ranges from about 0 weight percent
to about 5 weight percent, preferably from about 0.01 weight
percent to about 1 or 2 weight percent, more preferably from about
0.1 weight percent to about 0.5 weight percent active ingredient in
the masking composition.
XII. Alcohol.
[0071] In certain embodiments, the masking compositions of this
invention optionally include a water soluble alcohol. The alcohol
can act as a drying agent to speed drying of the film, as a wetting
agent, and as a biocide/preservative.
[0072] Suitable alcohols include, but are not limited to various
straight chain alcohols (e.g. propanol, methanol, ethanol, etc.)
and/or various aliphatic' polyols such as water soluble alcohols up
to octanol. The alcohol(s), when present, are typically present in
a range from about 0 weight percent to about 20 weight percent,
preferably from about 0.1 weight percent to about 10 weight
percent, more preferably from about 0.2 weight percent to about 5
weight percent, and most preferably from about 3 to about 4 weight
percent active ingredient of the masking composition.
EXAMPLES
[0073] The following examples are offered to illustrate, but not to
limit the claimed invention.
Example 1
[0074] To produce various surface protective coatings, of this
invention, components (as shown in Table 1 and Table 2) were
combined at room temperature and at atmospheric pressure by slow
stirring to form the various surface protective masking
compositions. The homogeneous masking compositions were then
adjusted to 8.5-9.5 by the addition of sodium hydroxide.
TABLE-US-00001 TABLE 1 One illustrative formulation of the masking
composition. Illustrative percent solids Percentage Component
Species active ingredient Per unit Water DI Water 87.2785% Film
Former Celanese 100.00 11.0000% Chemicals Cevol 205 PVA Plasticizer
Glycerine 100.00 1.0000% Flash corrosion Ammonium 100.00 0.0100%
inhibitor Benzoate Siloxane surfactant for BYK Chemie, 100.00
0.2000% aqueous systems BYK 347 Silicone defoamer BYK Chemie, 96.00
0.2000% BYK 024 low foam non-ionic Air Products, 100.00 0.0500%
wetting agent Dynol 604 (surfactant) Biocide Rohm and Haas 14.00
0.0100% Kathon LX 14 Colorant Azo Rubin 100.00 0.0015% pH adjuster
Ammonium Target 0.2500% Hydroxide pH 9.5 total solids 100.0000%
TABLE-US-00002 TABLE 2 One illustrative formulation of the masking
material comprising a cyclodextrin.. Illustrative Percent solids
Percentage Component species active ingredient per unit Water DI
Water 87.2285% Film Former Celanese 100.00 11.0000% Chemicals Cevol
205 PVA Plasticizer Glycerine 100.00 1.0000% Flash corrosion
Ammonium 100.00 0.0100% inhibitor Benzoate Cyclodextrin Gargill,
Cavitron 100.00 0.2000% 84000 Gamma Cyclodextrin Silicone
surfactant BYK Chemie, 100.00 0.2000% for aqueous systems BYK 347
Silicone defoamer BYK Chemie, 96.00 0.0500% BYK 024 low foam
non-ionic Air Products 100.00 0.0500% wetting agent Dynol 604
(surfactant) Biocide Rohm and Haas 14.00 0.0100% Kathon LX 14
Colorant Azo Rubin 100.00 0.0015% pH adjuster Ammonium Target
0.2500% Hydroxide pH 9.5 total batch size in gallons total solids
100.0000%
TABLE-US-00003 TABLE 3 One illustrative long shelf-life
formulation. percentage Function Ingredient percent solids per unit
Film Former Celanese, Celvol 205 100.00 5.0000% Polyvinyl Alcohol
film former Thickener Xanthan gum thickener 100.00 0.4000% CP
Kelco, Kelzan Biocide Arch Biocides, 14.00 0.0300% Proxel GXL
Humectant Glycerine 100.00 0.7500% Surfactant BYK Chemie, 100.00
0.2000% BYK 347 Surfactant Rhodia, Rhodasurf 100.00 0.3000% TDA 8.5
(tridecyl alcohol ethoxylate) Color Pigment, Azo Rubin 100.00
0.0015% Preservative Ammonium Benzoate 100.00 0.0100% pH adjuster
Ammonium Hydroxide 30.00 0.1200% Solvent DI Water 0.00 93.1885%
total solids 100.0000%
[0075] It is understood that the examples and embodiments described
herein are for illustrative purposes only and that various
modifications or changes in light thereof will be suggested to
persons skilled in the art and are to be included within the spirit
and purview of this application and scope of the appended claims.
All publications, patents, and patent applications cited herein are
hereby incorporated by reference in their entirety for all
purposes.
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