| |
| United States Patent
|
5,900,061 |
| Wright |
May 4, 1999 |
Sprayable roof coating systems
Abstract
Improved sprayable roof coating systems which provide immediate
waterproofing of a newly-sprayed latex-based ionic roof coating by
applying to the upper surface of such roof coating an ionic catalyst
having a pH opposed to the pH of such roof coating, whereby such
upper surface of such roof coating coagulates immediately to form a
thin waterproof surface layer on such roof coating and the bottom
portions of such roof coating are permitted to coagulate and bond to
the underlying roof normally. Also, latex-based sprayable roof
coating systems permitting use in roof mastics of recycled rubber
and spray equipment for such systems which do not clog up when air
spraying such recycled-rubber-containing roof mastics.
| Inventors: |
Wright; Winfield S.
(Roswell, NM) |
| Appl. No.:
|
08/951,014 |
| Filed: |
October 15, 1997 |
Related U.S. Patent Documents
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Application Number |
Filing Date |
Patent Number |
Issue Date |
|
379278 |
Feb., 1995 |
|
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| Current U.S.
Class: |
118/300 ;
222/321.1; 222/372; 222/382 |
| Current
International Class: |
B05B
7/24 (20060101); E04D 15/00 (20060101); E04D
7/00 (20060101); E04D 15/07 (20060101); B05B
9/04 (20060101); B67D 005/40 (); B65D 045/34 () |
| Field of
Search: |
118/300,323,410,200,206,263,600 52/749.12,DIG.16
427/186,421,426,333 428/142-144 156/356 401/48
239/139,532,195,197,215 417/900 222/372,382,381,321.1 |
References Cited
[Referenced By]
U.S. Patent
Documents
Primary Examiner: Simmons; David A.
Assistant Examiner: Padgett; Calvin
Attorney, Agent or Firm:
Stoneman; Martin L.
Parent Case Text
This is a continuation of application Ser. No. 08/379,278 filed Feb.
27, 1995, now abandoned.
Claims
What is claimed is:
1. A roof coating system comprising a spraying system including:
a. source means for providing a supply of sprayable roof mastic;
b. positive displacement pump means for pumping said sprayable roof
mastic;
c. first conduit means for permitting flow of said sprayable roof
mastic from said source means to said pump means;
d. spray means for spraying said sprayable roof mastic, said spray
means comprising an air-actuated spray gun; and
e. second conduit means for permitting flow of said sprayable roof
mastic from said pump means to said spray means
f. wherein said pump means is structured and arranged so as to allow
for passage to said second conduit means of undamaged rubber pieces
of about 1/2-inch length.
2. The roof coating system of claim 1 wherein said air spray gun is
structured and arranged to allow for passage of rubber pieces of
about 1/2-inch length.
3. The roof coating system of claim 2 wherein any valves and
conduits within said positive displacement pump are large enough in
size to transport without clogging a said sprayable roof mastic
containing up to about three pounds per gallon of rubber pieces each
up to about 1/2" long.
4. The roof coating system of claim 2 wherein said spray means
comprises a spray head and an air supply hose connected to said
spray head, including:
a. second source means for providing a supply of sprayable
waterproofing-inducing liquid having a pH opposite to that of said
sprayable roof mastic;
b. third conduit means for permitting flow of said sprayable
waterproofing-inducing liquid from said second source means to said
air supply hose adjacent said spray head.
5. The roof coating system of claim 4 including:
a. first valve means in said second conduit means for opening or
closing flow of said sprayable roof mastic through said second
conduit means; and
b. second valve means in said third conduit means for opening or
closing flow of said sprayable waterproofing-inducing liquid through
said third conduit means.
6. A roof coating system comprising a spraying system including:
a. source means for providing a supply of sprayable roof mastic;
b. pump means for pumping said sprayable roof mastic, said pump
means comprising a positive displacement pump;
c. first conduit means for permitting flow of said sprayable roof
mastic from said source means to said pump means;
d. spray means for spraying said sprayable roof mastic; and
e. second conduit means for permitting flow of said sprayable roof
mastic from said pump means to said spray means;
f. wherein said pump means is structured and arranged so as to allow
for passage to said second conduit means of undamaged rubber pieces
of about 1/2-inch length.
7. The roof coating system of claim 6 wherein any valves and
conduits within said positive displacement pump are large enough in
size to transport without clogging a said sprayable roof mastic
containing up to about three pounds per gallon of rubber pieces each
up to about 1/2" long.
8. The roof coating system of claim 6 wherein said spray means
comprises a spray head and an air supply hose connected to said
spray head, including:
a. second source means for providing a supply of sprayable
waterproofing-inducing liquid, said liquid being anionic if said
sprayable roof mastic is cationic and said liquid being cationic if
said sprayable roof mastic is anionic;
b. third conduit means for permitting flow of said sprayable
waterproofing-inducing liquid from said second source means to said
air supply hose adjacent said spray head.
9. The roof coating system of claim 8 including:
a. first valve means in said second conduit means for opening or
closing flow of said sprayable roof mastic through said second
conduit means; and
b. second valve means in said third conduit means for opening or
closing flow of said sprayable waterproofing-inducing liquid through
said third conduit means.
10. The roof coating system of claim 9 wherein said first valve
means and said second valve means are structured and arranged for
non-simultaneous operation.
11. The roof coating system of claim 9 wherein said positive
displacement pump comprises a diaphragm pump.
12. The roof coating system of claim 8 wherein said spray head is
large enough in size to transport without clogging a said sprayable
roof mastic containing up to about three pounds per gallon of rubber
pieces each up to about 1/2" long.
13. The roof coating system of claim 6 further comprising a mixing
system for mixing said sprayable roof mastic contained within said
source means.
14. A roof coating system comprising a spraying system including:
a. source means for providing a supply of sprayable roof mastic;
b. pump means for pumping said sprayable roof mastic, said pump
means comprising a positive displacement diaphragm pump;
c. first conduit means for permitting flow of said sprayable roof
mastic from said source means to said pump means;
d. spray means for spraying said sprayable roof mastic; and
e. second conduit means for permitting flow of said sprayable roof
mastic from said pump means to said spray means;
f. wherein any valves and conduits within said diaphragm pump are
large enough in size to transport without clogging a said sprayable
roof mastic containing up to about three pounds per gallon of rubber
pieces each up to about 1/2" long;
g. wherein said spray means comprises a spray head and an air supply
hose connected to said spray head; and
h. wherein said spray head is large enough in size to transport
without clogging a said sprayable roof mastic containing up to about
three pounds per gallon of rubber pieces each up to about 1/2" long.
15. The roof coating system of claim 14 wherein said spray means
further comprises:
a. second source means for providing a supply of sprayable
waterproofing-inducing liquid, said liquid being anionic if said
sprayable roof mastic is cationic and said liquid being cationic if
said sprayable roof mastic is anionic;
b. third conduit means for permitting flow of said sprayable
waterproofing-inducing liquid from said second source means to said
air supply hose adjacent said spray head.
16. The roof coating system of claim 15 further comprising:
a. first valve means in said second conduit means for opening or
closing flow of said sprayable roof mastic through said second
conduit means; and
b. second valve means in said third conduit means for opening or
closing flow of said sprayable waterproofing-inducing liquid through
said third conduit means;
c. wherein said first valve means and said second valve means are
structured and arranged for non-simultaneous operation.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in sprayable roof coating
systems and, more particularly, to improvements in providing sprayed
roof coatings of the type which include a latex-emulsion binder.
2. Description of the Prior Art
As is well-known, emulsions are intimate mixtures of two immiscible
liquids, one of them being dispersed in the other in the form of
fine droplets. A mixture of two miscible liquids, water and alcohol,
for example, will not produce an emulsion, but a more intimate
degree of dispersion, a solution. On the other hand, it is not
possible to form an emulsion with two immiscible liquids alone,
since such a system would lack stability. When water is mixed with
toluene, for instance, the two liquids will quickly separate.
The conditions change completely when a dilute soap solution,
instead of straight water, is mixed with an oil. A milky liquid
develops and remains stable for a considerable length of time,
forming a typical emulsion. Thus three components are necessary to
produce emulsions--two immiscible liquids and an emulsifying agent
or emulsifier to create the emulsion and to keep it stable.
To the casual observer emulsions appear as uniform, opaque liquids
or pastes of white or slightly yellowish color. The microscope
reveals that emulsions are by no means uniform substances. They are
non-uniform and consist of a multitude of small droplets or
particles, usually of spherical shape, and varying diameter,
floating in the surrounding liquid. Emulsions with particles of
large diameter are called coarse emulsions, and those with small
particles are fine emulsions. The particles and the liquids in which
they float are referred to as the phases of an emulsions. The
particles are the discontinuous phase, and the medium which is the
dispersion liquid is called the continuous phase. Also, since the
droplets of the discontinuous phase are enclosed from all sides, it
is also called the internal phase, and the continuous phase is also
called the external phase.
In most emulsions, one of the phases is water, or an aqueous
solution containing salts, soluble organic material, colloids, etc.
The continuous phase thus is also called the water phase. The
discontinuous is often called the oil phase, even it does not
consist of oil. Many substances constitute the oil phase, all having
the important common property of insolubility in water. These
substances include hydrocarbons, resins, waxes, nitrocellulose,
alkyds, rubber, vinyls and acrylics. They are referred to as "oil"
since they behave in emulsions much like oil.
The substances used in emulsions may be classified into two groups:
those which enter the water phase, and those which go into the oil
phase. The first group making up the aqueous portion must be water
soluble, or show a certain affinity toward water. This group has the
general name of hydrophilic substances. The other group of
substances which go into the oil phase have no affinity for water
but rather are attracted to oil or oil-like material. They are known
as hydrophobic substances. Typical hydrophilic substances are
water-soluble compounds, many metal salts, and substances containing
a relatively large number of oxy- or hydroxyl groups. Typical
hydrophobic substances are oils, fats, waxes, and all compounds
containing mainly carbon with few or no polar groups. This
difference is important in the selection of other materials which
will be blended with the emulsion, such as pigments, fillers,
cement, sand, and all other ingredients which may go into the making
of a mastic or concrete or mortar or other material desired. The
characteristic properties of an emulsion are dictated by the
external phase. If water is the external phase (O/W), the emulsion
may be diluted with water and not with oil or organic solvents. The
opposite is true with a W/O emulsion, which must be thinned with
organic solvents. If water is added, the viscosity will increase
rather than decrease. Indeed, this is one way of visually
distinguishing between the two types. Thinning with water will
indicate an oil-in-water emulsion if viscosity decreases. An
increase in viscosity would indicate a water-in-oil emulsion.
Many types of emulsifying agents are used in preparing emulsions.
Chemically they belong to different classes of compounds including
salts, acids, bases, and esters. Physically, they are substances of
medium molecular weight (above 300), and the molecules are of
elongated shape and belong to the mixed polar/non-polar type. These
emulsifying agents determine the type of emulsion produced and the
particle size of the dispersed droplets.
The emulsions generally used in mastics and cementitious
compositions are of the oil-in-water type, and sometimes contain
more than 50 percent water. They are nevertheless oil-in-water
emulsions, and are stable in the presence of the various salts and
oxides comprising the cement. Not all emulsions are compatible with
cement, and to select an emulsion primarily intended for production
of paint or adhesives to act as an admixture for a cementitious
mortar would be an error.
Latex emulsion systems are frequently used as the binder in mastic
and cementitious mixtures. The internal or disperse phase in a latex
system is a polymeric material comprised of spherically-shaped
particles with diameters in the range of 200-300 nm; and the
external phase or dispersion medium is usually aqueous phase. As is
mentioned hereinafter, such particles are usually kept from normally
aggregating by electrostatic repulsion between such particles due to
the presence of ionic charge at the surface of such particles.
Emulsion polymerization refers to a unique process employed for some
radical chain polymerizations. It involves the polymerization of
monomers which are in the form of emulsions. [The process is not
similar to suspension polymerization, but is quite different in its
mechanism and reaction characteristics.] Emulsion polymerization
differs from suspension polymerization in the type and smaller size
of the particles in which polymerization occurs and the kind of
initiator employed. Emulsion polymerization was first employed for
the production of synthetic styrene-butadiene rubbers during the
1940's when the supplies of natural rubber were cut off during World
War II. Conjugated dienes such as butadiene and isoprene are
presently polymerized and copolymerized in large part by the
emulsion process. In addition, emulsion polymerization is also used
extensively for vinyl acetate, vinyl chloride, acrylates,
methacrylates, and various copolymers of these monomers.
The emulsion polymerization process has several distinct advantages.
The physical state of the emulsion system makes it easy to control
the process. Thermal and viscosity problems are much less
significant than in bulk polymerization. The products of emulsion
polymerizations can in some instances be employed directly without
further separations but with appropriate blending operations. Such
applications involve coatings, finishes, floor polishes, and paints.
Aside from the physical difference between the emulsion and other
polymerization processes, there is one very significant kinetic
difference. For the other processes, there is an inverse
relationship between the polymerization rate and the polymer
molecular weight. This drastically limits one's practical ability to
make large changes in the molecular weight of a polymer. Large
increases in molecular weight can only be make by decreasing the
polymerization rate by lowering the initiator concentration or
lowering the reaction temperature. Emulsion polymerization is a
unique process in that it affords a means of increasing the polymer
molecular weight without decreasing the polymerization rate. Because
of a different reaction mechanism, emulsion polymerization has the
advantage of being able to simultaneously attain both high molecular
weights and high reaction rates. To a large extent, the molecular
weight and polymerization rate can be varied independently of each
other.
As is well-known, the main components of an emulsion polymerization
system are the monomer(s), dispersing medium, emulsifying agent, and
water-soluble initiator. The dispersing medium is the liquid in
which the various components are dispersed in an emulsion state by
means of the emulsifying agent. The dispersing medium is usually
water. The emulsifying agent is a surfactant whose action is due to
its having both hydrophilic and hydrophobic segments in its
molecular structure. Various other components may also be present in
the emulsion system.
Also, as is well-known, for ionic latex emulsions, the surface
charges at each particle (provided by the surfactant) assist in
keeping the emulsion dispersed because of the electrostatic
repulsion between the particles. This repulsion may be from cationic
or from anionic charges; and the ways of using appropriate
surfactants to maximize the dispersion of the emulsion by
appropriate electrostatic repulsion between the particles of the
emulsion are well-known. Additionally, it is known that an ionic
emulsion may be coagulated (through aggregation of the separate
particles and polymerization) by the addition of surfactants or
electrolyte with opposite charge to the ions used to stabilize the
latex particles. Additionally, it is known that coatings which
contain ionic latex emulsions as the binder should have a controlled
pH for best dispersion, i.e., maintaining the ionic electrostatic
repulsion. For example, if a cationic latex emulsion is used as a
binder (with pigments, etc.) in a mastic, the mastic should be
maintained with a high pH.
Also, typically, water-based latex roof mastics may be placed on
roofs in several manners, e.g., troweled, sprayed, etc. For such
roof mastics of low enough viscosity to be sprayed (typically by air
spray gun), the cure time is long enough (many hours or days) that
there is often a chance for rain while the water-based latex roof
mastic is not yet cured. It is noted that even if the cure time for
sprayed coatings would be drastically reduced, thus reducing the
chances for rain damage, there would be introduced new problems such
as maintaining good adhesion of the coating to the base.
Addition of water to sprayed roof coating by raindrops typically
softens the mastic to the point where it runs and destroys the
integrity of the roof coating. Thus, in rainy-weather areas or other
areas where rain may come shortly, roof spraying with such
latex-based coatings is avoided even where it is otherwise the best
coating to use for the job in terms of economics, long life,
efficiency, etc. Thus, there have existed needs for sprayable
latex-based roof coating systems which may be used in wet weather.
Furthermore, there have existed needs for sprayable economical
latex-based roof coatings which are exceptionally resilient and
long-wearing, both for use in dry areas and for use in wet areas.
The inclusion in latex-based roof coatings of the kinds of asphaltic
and recycled-rubber ingredients which have been used to provide
resilient and long-wearing properties on floors, roads, and walkways
has not been in the past successfully accomplished. To economically
use these materials in latex roof coating systems, spraying is
necessary. Thus, there exists a need for such sprayable resilient
and long-wearing latex-based roof coatings.
The usual spray systems used in roof coating systems do not work
efficiently with such materials (i.e., latex-based coatings
including asphaltic and recycled-rubber ingredients). One major
problem is that the usual air spray systems used currently in roof
coating tend to clog and spray inefficiently (or not at all) when
spraying such materials including such asphaltic and recycled-rubber
ingredients. Thus there exists a need in roof coating systems for
spraying systems which overcome such disadvantages.
OBJECTS OF THE INVENTION
Thus, the foregoing referred-to drawbacks and disadvantages of prior
roof coating systems have not been met and overcome in the prior art
roof coating systems, and it is the primary object of the invention
herein, a preferred form of which is described in detail
hereinafter, to overcome the said disadvantages and drawbacks and to
provide significant capabilities not previously available.
It is a further object of this invention to provide an improved roof
coating system which permits the use of water-based
latex-emulsion-bound roof coatings in wet weather, even in the face
of raindrops, yet does not interfere with other valuable properties
of such coatings, such as good adhesion to the underlying material.
Another object of this invention is to provide sprayable economical
latex-based roof coatings which are exceptionally resilient and
long-wearing, both for use in dry areas and for use in wet areas,
even including therein the kinds of asphaltic and recycled-rubber
ingredients which provide such benefits in floor coatings.
Yet another object of this invention is to provide spraying systems
which permit sprayable roof coating systems to include such
asphaltic and recycled-rubber ingredients.
SUMMARY OF THE INVENTION
According to the foregoing objectives, this invention provides a
roof coating system comprising: applying a roof coating by spraying
a roof mastic having an ionic latex emulsion binder and an
emulsion-stabilizing pH; and, shortly thereafter, inducing an
immediate thin coagulated waterproof layer on such roof coating by
applying upon such roof coating an ionic liquid having a pH opposite
to such emulsion-stabilizing pH of such roof mastic. And the present
invention further provides such a roof coating system wherein such
applying upon such roof coating of such ionic liquid is done by
spraying; and wherein such ionic latex emulsion binder is cationic
and such ionic liquid is anionic; and wherein such roof mastic has a
pH of about 11.0; and wherein such roof mastic has a pH of from
about 10.75 to about 11.5. Further provided according to the present
invention is such roof coating system wherein such ionic liquid
comprises citric acid; and wherein such ionic liquid is formulated
by mixing about 75% by volume of water with 25% by volume of citric
acid. Additionally, there is provided such roof system including a
last step of permitting such roof coating to cure, whereby a
fully-coagulated roof coating is formed, including provision of a
roof coating resulting thereby. Also provided by this invention is
such roof coating system wherein such roof mastic comprises
particles of recycled rubber; and wherein such roof mastic includes
from about one to about two pounds per gallon of recycled rubber
particles.
Yet additionally, according to the present invention, there is
provided such roof coating system wherein the spraying of such roof
mastic is done by use of spray equipment comprising: source means
for providing a supply of roof mastic; pump means for pumping such
roof mastic at a pressure of at least about 50 psi; first conduit
means for permitting flow of such roof mastic from such source means
to such pump means; spray means for spraying such roof mastic; and
second conduit means for permitting flow of such roof mastic from
such pump means to such spray means.
This invention also provides a method of providing immediate
waterproofing of a newly-sprayed latex-based ionic roof coating,
comprising the step of applying to the upper surface of such roof
coating an ionic catalyst having a pH opposed to the pH of such roof
coating, whereby such upper surface of such roof coating coagulates
immediately to form a thin waterproof surface layer on such roof
coating and the bottom portions of such roof coating are permitted
to coagulate and bond to the underlying roof normally.
And the present invention provides a roof coating system comprising
a sprayable roof mastic mixture consisting essentially of: latex
emulsion; recycled rubber particles; and an extender selected from
the class consisting of pigments and asphalt. Such roof coating
system is further provided wherein such sprayable roof mastic
mixture includes at least about one pound to about two pounds of
such recycled rubber particles per gallon of such mixture; and,
further, wherein such sprayable roof mastic mixture is sprayed onto
a roof as a coating. And such system is further provided wherein
such spraying is done using spraying equipment comprising: source
means for providing a supply of roof mastic; pump means for pumping
such roof mastic at a pressure of at least about 50 psi; first
conduit means for permitting flow of such roof mastic from such
source means to such pump means; spray means for spraying such roof
mastic; and second conduit means for permitting flow of such roof
mastic from such pump means to such spray means. Also provided is
such roof coating system wherein asphalt is the extender and wherein
the recycled rubber particles consist essentially of tire rubber,
including provision of the product resulting therefrom; and,
further, wherein pigments are the extender and wherein the recycled
rubber particles consist essentially of tennis shoe and tennis ball
rubber, including provision of the product resulting therefrom.
Additionally provided by this invention is such roof coating system
wherein the recycled rubber particles consist essentially of: from
ground tire rubber, elongated pieces about 1/2" long passing through
a #5 mesh; from ground tire rubber, particles passing through a #20
mesh; and from ground tire cord, particles passing through a 1/4"
mesh.
Even further, according to the present invention, there is provided
a roof coating system comprising a spraying system including: source
means for providing a supply of sprayable roof mastic; pump means
for pumping such sprayable roof mastic; first conduit means for
permitting flow of such sprayable roof mastic from such source means
to such pump means; spray means for spraying such sprayable roof
mastic; and second conduit means for permitting flow of such
sprayable roof mastic from such pump means to such spray means; and,
further wherein such pump means comprises a positive displacement
pump; and, even further, wherein such spray means comprises an air
spray gun; and yet further, wherein any valves and conduits within
such positive displacement pump are large enough in size to
transport without clogging a such sprayable roof mastic containing
up to about three pounds per gallon of rubber pieces each up to
about 1/2" long.
Additionally, this invention provides a roof coating system
including providing a sprayable roof coating material comprising a
latex emulsion and an ingredient selected from the class consisting
essentially of pigments and asphalt; and providing a sprayable
waterproofing-inducing liquid having a pH opposite to that of such
sprayable roof coating material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial illustration, in perspective, showing a
preferred embodiment of the roof coating system of the present
invention, illustrating a roof being coated according to such
embodiment.
FIG. 2 is a partial sectional view of a roof (such as shown in FIG.
1) before any coating has been done.
FIG. 3 is a view, partially in section, of the roof of FIG. 2, shown
being coated by spraying on of a roof mastic according to a
preferred embodiment of the present invention.
FIG. 4 is a view, partially in section, of the sprayed roof of FIG.
3, shown shortly after spraying thereon of roof mastic, when being
impinged upon by raindrops.
FIG. 5 is a view, partially in section, of the sprayed roof of FIG.
3, shown immediately after spraying thereon of a coating of roof
mastic according to a preferred embodiment of the present invention,
when such coating is being sprayed by a catalyst according to a
preferred embodiment of the present invention.
FIG. 6 is a view, partially in section, of the sprayed roof of FIG.
5, shown immediately after spraying onto the roof mastic coating of
the catalyst of the present invention, when being impinged by
raindrops.
FIG. 7 is a sectional view of the coated roof shown in FIG. 6, shown
after complete curing of the coating according to a preferred
embodiment of the present invention.
FIG. 8 is a pictorial illustration, in perspective, of a spraying
system according to a preferred embodiment of the present invention.
FIG. 9 is a front right view, partially in section, of the pump
means shown in FIG. 8, the section being through the conduit means
to and from such pump means.
FIG. 10 is a pictorial illustration, in perspective, of a
representative mixing system which may be used in making a roof
mastic according to a preferred embodiment of the present invention.
FIG. 11 illustrates a recipe, in form familiar to those skilled in
the art, for the mixing of a roof mastic according to a preferred
embodiment of the roof coating system of the present invention.
FIG. 12 illustrates another recipe, in form familiar to those
skilled in the art, for the mixing of a roof mastic according to a
preferred embodiment of the roof coating system of the present
invention.
FIG. 13 illustrates another recipe, in form familiar to those
skilled in the art, for the mixing of a roof mastic according to a
preferred embodiment of the present invention.
FIG. 14 illustrates another recipe, in form familiar to those
skilled in the art, for the mixing of a roof mastic according to a
preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS AND THE BEST MODE OF
PRACTICE
FIG. 1 is a pictorial illustration, in perspective, showing a
preferred embodiment of the roof coating system of the present
invention, illustrating a roof 21 being coated according to such
embodiment. Shown is a worker 22, being supported by worker support
structure 23, using spraying equipment 24 to spray roof mastic 25
(made with a water-based latex binder in accordance with this
invention as described elsewhere herein) onto roof 21 in a generally
right to left direction, thus making a roof mastic coating 26 on
roof 21. Another worker 27, also being supported by worker support
structure 23, is shown using spraying equipment 28 to spray a
catalyst 29 (prepared in accordance with the present invention as
elsewhere described herein) onto roof mastic coating 26 shortly
after the spraying thereof by worker 22, worker 27 also being shown
working in a generally right to left direction. Air hose 30 is
attached to the spray end 31 of spraying equipment 24 in a
well-known manner for air spray guns. Similarly, air hose 32 is
attached to the spray end 33 of spraying equipment 28 in a
well-known manner for air spray guns. As the catalyst 29 being
sprayed upon roof mastic coating 26 by worker 27 comes into contact
with roof mastic coating 26, the catalyst 29 (as elsewhere herein
described) induces immediate coagulation of the surface of roof
mastic coating 26 to form a thin waterproof surface layer 34 on roof
mastic coating 26. Spraying equipment 24 may, as is hereinafter
described, be part of the spraying system shown in detail in FIG. 8.
FIG. 2 is a partial sectional view of a roof 21 before any coating
has been done. As is well-known in the art, roof 21 will be cleaned
and otherwise prepared to receive a coating in a manner dependent in
detail upon the roof material of the roof 21 to be coated.
FIG. 3 is a view, partially in section, of roof 21 shown being
coated by spraying on through spray end 31 (of spray equipment 24)
of roof mastic 25 according to a preferred embodiment of the present
invention. As shown, when sprayed upon roof 21, roof mastic 25 forms
roof mastic coating 26 upon roof 21. It is noted that, in FIGS. 3
through 7, the thickness of roof mastic coating 26 is exaggerated
for purposes of illustration; the actual thickness is a fraction of
an inch, similar to that of other well-known mastics prepared with a
latex emulsion binder and sprayed. Similarly, the viscosity of
sprayable roof mastics according to the present invention is in
well-known ranges, i.e., high enough to form a coating, and low
enough that gravity maintains a horizontal coating with similar
thickness throughout each area.
FIG. 4 is a view, partially in section, of roof 21 shown shortly
after spraying thereon of roof mastic 25 (made with a water-based
latex as a binder) to form roof mastic coating 26. As shown, and as
is well-known in the roofing industry, when being impinged upon by
raindrops 35, freshly-coated roof mastic coating 26, which has had
no chance to cure, becomes watery and loses its integrity as a
coating.
FIG. 5 is a view, partially in section, of roof 21 shown immediately
after spraying thereon of roof mastic coating 26 according to a
preferred embodiment of the present invention, when such coating 26
is being sprayed by a catalyst 29 according to a preferred
embodiment of the present invention.
In the sprayable roof mastics used according to the present
invention, an ionic latex emulsion is used as the binder, and the
latex remains stabilized by electrostatic repulsion of the particles
therein by maintaining the pH of the roof mastic within desired
ranges. Catalyst 29 is an ionic liquid of opposite pH to that of the
roof mastic; and it has been discovered that application by spraying
of such catalysts to the surface of such a roof mastic coating
"shocks" the surface of the coating in such manner as to
sufficiently destroy the electrostatic stabilization of a thin
surface portion of the roof mastic coating to produce coagulation
and polymerization within such thin surface portion of the roof
mastic, forming an immediate thin waterproof surface layer. However,
importantly, the "shocked" layer of the roof mastic coating does not
ordinarily affect the bottom portions of the roof mastic coating,
permitting relatively normal curing and coagulation/aggregation of
such bottom portions in well-known ways to provide desired
properties and to form desired adhesions to the underlying roof
portions. In this manner, catalyst 29 quickly interreacts with the
surface 36 of coating 26.
FIG. 6 shows the sprayed roof 21 immediately after spraying onto the
roof mastic coating 26 of the catalyst 29 of the present invention,
when being impinged by raindrops 35. As shown, catalyst 29 has
quickly interreacted with the surface 36 of roof mastic coating 26
to form thin waterproof surface layer 34, so that raindrops 35 fall
harmlessly onto thin waterproof layer 34 and are thereby prevented
from destroying the integrity of the underlying portions of roof
mastic coating 26. Thus, roof mastic coating 26 may continue to cure
and coagulate in well-known manners. FIG. 7 shows roof 21 after
complete curing of the coating 26 of the present invention which, as
shown, has been protected from rain during curing by the waterproof
layer 34 of the upper surface 36 of coating 26.
FIG. 8 shows a spraying system 37 constructed according to a
preferred embodiment of the present invention, which will be further
described in detail hereafter after description of the roof mastics
of the present invention for which such spraying system 37 are
especially advantageous; and FIG. 9 shows the pump means 38 of
spraying system 37 in detail.
FIG. 10 shows a representative mixing system 39 which may be used in
making roof mastics 25 according to preferred embodiments of the
present invention. Shown is mixing kettle 40, which may contain roof
mastic ingredients 41 as hereinafter described. Mixer-grinder 42, of
a well-known type, contains base support 43, to which are connected,
through attachment support 44, motor 45, motor shaft 46,
pulley-drive 47, and driven shaft 48. Motor 45 drives pulley-drive
47, which drives shaft 48. Shaft 48 has connected at its lower end
mixer-grinder wheel 49 which, when placed within the ingredients 41
within kettle 40, may be rotated at a selected speed in well-known
ways to perform mixing or grinding of ingredients 41.
FIG. 11 illustrates a recipe, in form familiar to those skilled in
the art, for the mixing of one representative roof mastic according
to a preferred embodiment of the roof coating system of the present
invention. According to the present habit and nomenclature of those
skilled in the present arts, in mixing mastics for use in coatings,
the earliest ingredients which go into a mixing kettle, especially
when such ingredients require a time for mixing or high-speed
grinding, are called the GRIND. After all of such initial
ingredients are added and any necessary high-speed grinding and/or
mixing is accomplished (as is well-known in the art), the then-added
later ingredients, which include any latex binder, to be slowly
blended in the kettle, are called the LETDOWN.
For the cationic latex mastic of FIG. 11, for example, the following
approximate manufacturing procedure is recommended when using the
proprietary latex (known as "Rhoplex EC-1791") of Rohm and Haas
Company: (1) charge the water, the water conditioner, the dispersing
agent, and the defoamer of the GRIND to the mixing kettle; (2) while
mixing at slow speed, add the pigments (zinc oxide, titanium oxide,
calcium carbonate) and the mildewcide to the kettle; (3) After all
the pigments are in the kettle, stop the mixer and scrape the side
and bottom of the kettle; (4) Turn the mixer back on and grind at
high speed for 15-30 minutes, or until a good grind is obtained
(Hegman reading of 4.5-5.0); (5) slow the mixer to its slowest
speed; (6) for the LETDOWN, add the ammonium hydroxide and then the
latex and the other LETDOWN ingredients, making sure the ethylene
glycol and thickening agent are added quickly (at most within about
five minutes) after the ammonium hydroxide (or necessary thickening
time may drastically increase; (7) Note--since this example roof
mastic includes a cationic latex binder and, according to this
preferred embodiment of the present invention, this sprayable roof
mastic will be used with a sprayable catalyst preferred to be a 25%
solution of citric acid, care should be taken in well-known ways to
finish, store and spray this mastic with the preferred pH reading of
about 10.75 to about 11.5, it being highly preferred to have a pH of
about 11.0 for best interaction with catalyst during spraying.
FIG. 12 illustrates another representative recipe, in form familiar
to those skilled in the art, for the mixing of a cationic roof
mastic according to a preferred embodiment of the roof coating
system of the present invention. This example uses a proprietary
latex of Union Carbide Co. available under the name "UCAR Latex
123". Again, the pH of the resulting sprayable mastic should be
about 11.0 for best results with the sprayed catalyst (for best
immediate waterproofing); and this sprayable roof mastic will
preferably be used with a sprayable catalyst of a 25% solution of
soda ash.
FIG. 13 illustrates a recipe, in form familiar to those skilled in
the art, for the mixing of an improved sprayable roof mastic,
according to a preferred embodiment of the present invention, which
gives greatly improved characteristics (more resiliency, longer
life, etc.). This mastic is light in color and produces a
light-colored roof coating which is advantageous in sunny areas.
Furthermore, this improved mastic may be used with a sprayed ionic
catalyst like a 25% citric acid solution to form an immediate thin
waterproof layer on the surface of a roof coating sprayed from this
improved mastic, so as to offer rain protection during the cure
period. Note that in this recipe, the ingredients ground light
rubber A and ground light rubber B consist respectively of materials
like recycled tennis shoes and recycled tennis balls; and these
ingredients may be purchased from Atlos Rubber.
FIG. 14 illustrates another recipe, in form familiar to those
skilled in the art, for the mixing of an improved sprayable roof
mastic according to a preferred embodiment of the present invention.
Thorough mixing of the GRIND takes a mix time of 30-45 minutes. This
improved roof mastic has much more toughness and resiliency than
ordinary mastics; and it too can be used (with proper pH of about
10.75 to about 11.5, of course, for best results) with a sprayed
ionic catalyst like a 25% citric acid solution to form an immediate
thin waterproof layer on the surface of a roof coating sprayed from
this improved mastic, so as to offer rain protection during the cure
period. Note that in this recipe, the following ingredients may be
obtained from recycled tires and represent a particularly excellent
use in roofing of these otherwise-hard-to-dispose-of materials; and
these ingredients may be obtained from Baker Rubber: (1) RUBBER--#5
buffings consists of elongated pieces of about 1/2" each of recycled
tire buffings which pass through a #5 mesh; (2) RUBBER--#WRF-20
consists of ground recycled-tire pieces passing through a #20 mesh;
and (3) CORE--consists of ground recycled tire cord passing through
a 1/4" mesh. It is further noted, with respect to the roof mastic of
FIG. 14, that thickening agent should be added until the viscosity
is just high enough to keep the rubber solids in suspension in the
mixing kettle; if the viscosity is permitted to be higher than this,
the to-be-described pumping of the roof mastic will become more
difficult.
Typically, in applying sprayed mastic coatings, a common air spray
gun of well-known type is used. Typically, the mastic to be sprayed
is supplied to the spray head through a pipe of about an inch in
diameter, and an air hose is attached to the spray head to provide
air under pressure to spray the supplied mastic in well-known ways.
However, in spraying the roof mastics using recycled rubber pieces
according to the present invention, such typical air spray guns can
not do an efficient job due to the clogging or near-clogging of the
supply pipe due to the presence of such rubber pieces in such roof
mastic, especially the roof mastics of the present invention using
recycled tires wherein pieces of tire rubber about 1/2 inch long are
common.
It has been found that such described roof mastics with recycled
rubber ingredients may be sprayed with a typical air spray gun spray
head arrangement only if roof mastic supplied in the supply pipe
leading to the spray head is supplied at a pressure of at least
about 50 pounds per square inch. Such supply with a positive
pressure prevents clogging or near-clogging of the supply pipe and
permits efficient spraying of such roof mastics onto a roof. It has
further been found that using improved spray equipment wherein a
positive displacement pump supplies such roof mastic at such
pressures to such air spray head eliminates such problems and works
efficiently as spray equipment for spraying such
recycled-rubber-containing roof mastics.
FIG. 8 illustrates a preferred embodiment of the spraying system 37
of the present invention. And FIG. 9 illustrates the well-known
details of the pump means 38 which provides the desired pressures in
supplying roof mastic to a spray head. With respect to the pump
means 38 (see FIG. 9), inlet air enters reciprocating motor 53,
through porting of reciprocating motor control valve spool 54, into
right pumping chamber 75, forcing right diaphragm 60 to the far
right activated position against outer wall of right pumping chamber
(fluid side) 58. Such movement of right diaphragm 60 pulls diaphragm
connecting shaft 69 to its full right position because of its
attachment to right diaphragm holding plate 71. As right diaphragm
holding plate 71 moves right, it pulls the attached left diaphragm
holding plate 70 to its full right position. Movement of left
diaphragm holding plate 70 and left diaphragm 59 forces air out of
left pumping chamber (air side) 74, through left air port 76,
through porting of reciprocating motor control valve spool 54 and
out motor exhaust port 73. Left diaphragm holding plate 70 pushes
left activating rod control valve spool 55 and its attached
reciprocating motor control valve spool 54 to the right side of its
travel within its ported cavity, also extending right activating rod
control valve spool 56 into right pumping chamber (air side) 75.
With reciprocating motor control valve spool 54 moved right, exhaust
porting through left air port 76 and motor exhaust port 73 is
blocked by reciprocating motor control valve spool 54. At that same
time, inlet air, through air inlet 72, is allowed to enter left air
port 76 through the opened port in reciprocating motor control valve
spool 54. Air entering left pumping chamber (air side) through left
air port 76 moves the assembly consisting of left diaphragm holding
plate 70, right diaphragm holding plate 71, diaphragm connecting
shaft 69, left diaphragm 59 and right diaphragm 60 to the left. This
forces liquid (roof mastic in this use) in left pumping chamber
(fluid side) 57 out through the left fluid outlet as left discharge
check ball 65 is forced off of left discharge check ball seat 66.
Left inlet check ball 61 is forced against left inlet check ball
seat 62 prohibiting fluid flow into the inlet manifold. As right
diaphragm 60 moves left, air within right pumping chamber (air side)
75 is forced through right air port 77, into the now opened port in
reciprocating motor control valve spool 54, and out through air
outlet 73. Enlarging of right pumping chamber (fluid side) 58,
causes fluid inlet manifold 51 negative pressure, raising right
inlet check ball 63 from its right inlet check ball seat 64, (right
discharge check ball 67 is seated on right discharge check ball seat
68 by gravity), and allowing atmospheric pressure to push fluid
through the inlet manifold and into right pumping chamber (fluid
side) 58. When right diaphragm holding plate 71 contacts right
activating rod control valve spool 56, it in turn begins to shift
the valve spool to its opposite position, again reversing air flow
and fluid pump movement. As is well known, alternating compressing
of left and right fluid pumping chambers forces fluid out the pump
outlet 52 developing flow and pressure proportional to the air
supply pressure and volume. It is noted that the passages and check
ball valves of pump means 38 through which mastic must flow must be
of sufficient size to prevent clogging, for example, due to rubber
pieces in the mastic. It has been found, for pumping the mastic
described in FIG. 14, that hoses, passages, and valves of about
two-inch diameter are sufficient for this purpose.
With respect to the spraying system 37 of FIG. 8, whose various
elements are well-known but whose combinations and uses herein are
new, there is described a preferred embodiment thereof. The
illustrated source means provides drum 81, shown as containing a
supply of the roof mastic 25 to be sprayed, which, for example, may
be the recycled-ground-tire containing mastic whose manufacturing
recipe is given in FIG. 14, which mastic contains pieces of rubber
up to about 1/2 inch long, as previously described. Pump means 38 is
connected to the interior holding portions of drum 81 by first
conduit means 82 comprising a pipe or hose preferably about two
inches in diameter extending from drum 81 to the fluid inlet
manifold 51 of pump means 38. By operation of pump means 38,
described specifically above with respect to FIG. 9, the mastic to
be sprayed is pumped from the fluid outlet manifold 52 of pump means
38 at a pressure preferred to be at least about fifty pounds per
square inch for mastics like the mentioned recycled-ground-tire
containing mastic.
Spray means 83 (corresponding to the spraying equipment shown held
by workers in FIG. 1) is connected to fluid outlet manifold 52 of
pump means 38 by second conduit means 84, preferably comprising a
hose about two inches in diameter. Spray means 83 preferably
comprises a pipe 85 containing shut-off valve 85a along its length
and a spray head 86 (well-known in the art of air spray guns for
spraying mastic) at its end. Thus, a roof mastic 25 may be pumped at
the selected pressure to the spray head 86, from where it is sprayed
in well-known ways onto a roof.
Air pressure is required both by the illustrated pump means 38 and
by spray head 86. Such air under pressure may be supplied from a
common source through air line 87, through air filter 88, then
branching into two air conduits 89 and 90, each containing an air
regulator 91 and shut-off valve 92. Then air conduit 90 provides
inlet air into air inlet 72 of pump means 38, whose operation has
been herein described, and air conduit 89 provides air under
pressure (through spray valve 91) to spray head 86, for operation of
spray head 86 in well known ways.
Optionally (with reference to FIG. 8), a source of sprayable
waterproof-inducing liquid (suitable to act as a catalyst 29
according to the present invention when sprayed upon a coating 26 of
roof mastic 25) such as container 100 may be connected by a suitable
conduit such as hose 101 to air conduit 89 adjacent spray head 86,
as shown. Valve 102 serves to open or close the flow of such
sprayable waterproof-inducing liquid 29 through hose 101 in a
well-known manner. By using this option, a roof spray worker (such
as worker 22 in FIG. 1) may first spray the roof mastic coating 26,
then close valve 85a to stop the flow of mastic, then open valve 102
to start the flow of catalyst 29, and then immediately spray the
catalyst 29. This will be especially advantageous for small jobs
where it is desired to use one worker with one spray-equipment tool.
It is noted that, with reference to FIGS. 4 through 7, elements
labeled with reference numbers 50 may be present and represent
pieces of recycled rubber, as found when using roof mastics like
those of FIGS. 13 and 14.
Further advantages of applicant's invention will be apparent to
those skilled in the art from the above descriptions and the below
claims.
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