U.S. patent application number 10/812541 was filed with the patent office on 2005-11-17 for roofing shingles provided with release coating.
This patent application is currently assigned to BUILDING MATERIALS INVESTMENT CORPORATION. Invention is credited to Kerkar, Awdhoot Vasant, Rodrigues, Tommy, Sieling, Frederick W..
Application Number | 20050252141 10/812541 |
Document ID | / |
Family ID | 35197568 |
Filed Date | 2005-11-17 |
United States Patent
Application |
20050252141 |
Kind Code |
A1 |
Kerkar, Awdhoot Vasant ; et
al. |
November 17, 2005 |
Roofing shingles provided with release coating
Abstract
A roofing shingle and a method of manufacturing a roofing
shingle wherein the bottom surface of said shingle is provided with
a release coating of a continuous film of particles having poor
interlaminar strength due to the particles having good to perfect
basal cleavage. The release coating significantly eases separation
of roofing shingles that stick together when stacked during storage
and transit in warm environments.
Inventors: |
Kerkar, Awdhoot Vasant;
(Rockaway, NJ) ; Rodrigues, Tommy; (Union, NJ)
; Sieling, Frederick W.; (Bound Brook, NJ) |
Correspondence
Address: |
GAF MATERIALS CORPORATION
Attn: William J. Davis, Esq.
Legal Department, Building No. 10
1361 Alps Raod
Wayne
NJ
07470
US
|
Assignee: |
BUILDING MATERIALS INVESTMENT
CORPORATION
|
Family ID: |
35197568 |
Appl. No.: |
10/812541 |
Filed: |
March 30, 2004 |
Current U.S.
Class: |
52/551 |
Current CPC
Class: |
E04D 1/26 20130101; E04D
2001/005 20130101 |
Class at
Publication: |
052/551 |
International
Class: |
E04D 001/34 |
Claims
What is claimed is:
1. A roofing shingle comprising a top and bottom surface, the
bottom surface provided with a release coating of a continuous film
of particles having good to perfect basal cleavage.
2. A shingle in accordance with claim 1 wherein said release
coating is disposed on the pressure point portions of said bottom
surface.
3. A shingle in accordance with claim 1 wherein said roofing
shingle is a shingle selected from the group consisting of a
laminated shingle and a strip shingle.
4. A shingle in accordance with claim 3 wherein said particles are
in the class phyllosilicates.
5. A shingle in accordance with claim 4 wherein said particles are
selected from the group consisting of Allophane, Apophyllite,
Bannisterite, Carletonite, Cavansite, Chrysocolla, Baileychlore,
Chamosite, Chlorite, Clinochlore, Cookeite, Nimite, Pennantite,
Penninite, Sudioite, Glauconite, Illite, Kaolinite,
Montmorillonite, Palygorskite, Pyrophyllite, Sauconite, Talc,
Vermiculite, Delhayelite, Elpidite, Fedorite, Franklinfumaceite,
Franklinphilite, Gonyerite, Gyolite and Leucosphenite; Biotite,
Lepidolite, Muscovite, Paragonite, Phlogopite, Zinnwaldite,
Minehillite, Nordite, Pentagonite, Petalite, Prehnite, Rhodesite,
Sanfomite, Antigorite, Clinochrysotile, Lizardite, Orthochrysotile,
Serpentine, Wickenburgite, Zeophyllite.
6. A stack of roofing shingles comprising a plurality of said
roofing shingles of claim 1 wherein the top surface of each roofing
shingle faces the bottom surface of its adjoining roofing
shingle.
7. A stack of roofing shingles comprising a plurality of said
roofing shingles of claim 2 wherein the top surface of each roofing
shingle faces the bottom surface of its adjoining roofing
shingle.
8. A stack of roofing shingles comprising a plurality of said
roofing shingles of claim 3 wherein the top surface of each roofing
shingle faces the bottom surface of its adjoining roofing
shingle.
9. A stack of roofing shingles comprising a plurality of said
roofing shingles of claim 4 wherein the top surface of each roofing
shingle faces the bottom surface of its adjoining roofing
shingle.
10. A stack of roofing shingles comprising a plurality of said
roofing shingles of claim 5 wherein the top surface of each roofing
shingle faces the bottom surface of its adjoining roofing
shingle.
11. A method of manufacturing a roofing shingle comprising applying
a release coating of a continuous film of particles having good to
perfect basal cleavage to a bottom portion of a shingle.
12. A method of manufacturing a roofing shingle in accordance with
claim 11 wherein said release coating is applied on pressure point
portions of said bottom surface.
13. A method of manufacturing a roofing shingle in accordance with
claim 11 wherein said particles are suspended in a water based
suspension.
14. A method of manufacturing a roofing shingle in accordance with
claim 13 wherein said water based suspension is sprayed onto the
shingle.
15. A method of manufacturing a roofing shingle in accordance with
claim 13 wherein said water based suspension is brushed onto the
shingle.
16. A method of manufacturing a roofing shingle in accordance with
claim 13 wherein said water based suspension is wiped onto the
shingle.
17. A method of manufacturing a roofing shingle in accordance with
claim 11 wherein said particles are selected from the group
consisting of Allophane, Apophyllite, Bannisterite, Carletonite,
Cavansite, Chrysocolla, Baileychlore, Chamosite, Chlorite,
Clinochlore, Cookeite, Nimite, Pennantite, Penninite, Sudioite,
Glauconite, Illite, Kaolinite, Montmorillonite, Palygorskite,
Pyrophyllite, Sauconite, Talc, Vermiculite, Delhayelite, Elpidite,
Fedorite, Franklinfurnaceite, Franklinphilite, Gonyerite, Gyolite
and Leucosphenite; Biotite, Lepidolite, Muscovite, Paragonite,
Phlogopite, Zinnwaldite, Minehillite, Nordite, Pentagonite,
Petalite, Prehnite, Rhodesite, Sanfornite, Antigorite,
Clinochrysotile, Lizardite, Orthochrysotile, Serpentine,
Wickenburgite, Zeophyllite.
18. A method of manufacturing a roofing shingle in accordance with
claim 11 wherein the release coating is applied to a self seal
adhesive portion on the bottom portion of the shingle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to roofing shingles
provided with a release coating. More specifically, the present
invention focuses upon laminated roofing shingles whose bottom
surface is coated with a continuous film of release material
characterized by poor interlaminar strength.
[0003] 2. Background of the Prior Art
[0004] Roofing shingles are often divided into two main groups:
strip shingles and dimensional or laminated shingles. The most
common type of roofing shingles are laminated. These laminated
shingles, often referred to as "architectural shingles," include a
top layer, which those skilled in the art speak of as the "anterior
layer" and a bottom layer, referred to as the "posterior layer."
The back surface of the anterior layer is bonded to the front
surface of the posterior layer. The posterior layer is bonded so
that it mates with the lower butt portion of the anterior layer and
further overlaps the anterior layer over a fraction of the
undivided headlap portion.
[0005] Strip shingles are also prevalent. Strip shingles are single
layer asphalt shingles that are manufactured in strips, typically
three times as long as they are wide.
[0006] A problem associated with both laminated and strip roofing
shingles lies in shipment and storage of these shingles. Shingles
are packaged in bundles of 20 to 25 shingles. Laminated shingles
are bundled in either alternating anterior layer to anterior layer
and posterior layer to posterior layer configuration or each
shingle is stacked one atop another so that the anterior layer of a
first shingle faces the posterior layer of the adjoining shingle,
that is, front surface-to-front surface, back surface-to-back
surface or front surface-to-back surface. Furthermore, the bundles
are typically stacked and palletized in independent columns or in
an interwoven "E" pattern.
[0007] Independent of the bundling method, the high pressure caused
by stacking of these heavy roofing shingles, causes the shingles to
stick together. Additionally, there is a transition region found in
many laminated shingles due to the posterior layer having a smaller
width than the anterior layer added thickness caused by the
overlapping shingle layers in laminated shingles creates a hump.
This transition region is most often characterized by a stepped
profile. The stepped transition region located at the sharp
transition in thickness between the top portion of the anterior
layer, which is unbonded, and the portion of that layer bonded to
the posterior layer, results in a pressure point within the stack.
The pallet arrangements magnify the pressure observed in a single
stack. As such, pressure at the pressure point of each shingle is
magnified. This pressure point results in distortion and localized
sticking of the shingles. The degree of sticking together of
adjoining shingles is proportional to load, which imparts
pressures. Thus, shingles at the bottom of a stack are more prone
to sticking than those at the top where the pressure is lower.
[0008] The sticking together of roofing shingles is observed
predominantly during warmer months and in hotter climates when
temperatures approach the softening point of the shingle asphalt
coating, resulting in asphalt flow. The sticking is also a function
of time where longer periods of compression time increase the
sticking. The combination of high temperature and long storage
times results in very damaging sticking. Mechanical interlock of
asphalt within the granules under the effect of the pressure point
also contributes to the sticking phenomenon.
[0009] The problem discussed above has been recognized in the art.
Among the expedients attempted to overcome this problem has been
the application of a plastic release tape, positioned in the
pressure point region of each shingle. This method has been
successful, albeit not 100% effective. Not only is this method not
totally effective but, in addition, application of release tape
adds significant material and labor expense.
[0010] The failure to find a complete solution to the problem of
sticking together of roofing shingles when stacked in stacks of a
plurality of roofing shingles and disposed on pallets during
shipping and storage of roofing shingles prior to installation on
building roofs evidences the need in the art for a new roofing
shingle which overcomes this problem. The solution to this problem
is constrained by the need to retain the roofing shingle design
that has proven effective in protecting roofs.
BRIEF SUMMARY OF THE INVENTION
[0011] A new roofing shingle has now been developed which overcomes
the problem of sticking together of roofing shingles, when stacked
in a plurality of roofing shingles and disposed on pallets, during
transit and storage. This new shingle design does not adversely
affect roofing shingle performance in protecting roofs and
represents a minimal additional expense in terms of additional
processing complexity and component cost.
[0012] In accordance with the present invention a new roofing
shingle has been developed. The shingles of this invention include
mono- and multiply types as in a roll on sheet used for built up
roofing and also includes individual shingles of the tabbed variety
which in turn includes mono-layered and composite types having a
headlap portion and a tabbed portion with or without a backer strip
underlying the tabs. The shingle includes a surface coated with a
release coating.
[0013] In accordance with the present invention a new method of
manufacturing a roofing shingle is disclosed. The method provides
for applying a release coating to the shingle during
manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention may be better understood by reference
to the accompanying drawings of which:
[0015] FIG. 1 is a view of the top surface of a laminated roofing
shingle in accordance with the present invention;
[0016] FIG. 2 is a view of the bottom surface of the roofing
shingle of FIG. 1 in accordance with the present invention.
DETAILED DESCRIPTION
[0017] The following detailed description of the invention is to a
2-ply laminated shingle for convenience but the invention is not
limited to such a shingle. The roofing shingle 1 in accordance with
the present invention is depicted as it appears viewed from its top
surface in FIG. 1 and from its bottom surface in FIG. 2. The
roofing shingle is preferably a laminate of an anterior layer 2
having a front surface and a back surface and posterior layer 5
having a front surface and a back surface. The anterior layer
includes an undivided headlap portion 3 and a lower butt portion 4.
The posterior layer 5, often referred to in the art as a "backer
strip," is usually rectangularly shaped. The front surface of the
posterior layer 5 is bonded to the back surface of the anterior
layer 2 so that it completely mates with the lower butt portion 4
and provides an overlap of the two layers over a fraction of the
undivided headlap portion 3. However, the shingle may be
mono-layered or have three or more layers.
[0018] Both the anterior layer 2 and the posterior layer 5
preferably comprise a fiberglass mat, an organic or inorganic felt
or fabric stock impregnated with asphalt and coated with weather
resistant mineral granules.
[0019] To provide a roofing shingle 1 which does not stick to its
neighboring shingles in a stack, especially when the stack is
disposed on a pallet, a coating of a release material 100 is placed
on the bottom surface of the shingle 1, as depicted in FIG. 2, and
the shingles 1 are bundled so that the top surface of each shingle
is adjacent the bottom surface of its neighboring shingle. The
release coating comprises a continuous film of solid particles
having poor interlaminar strength when applied as a slurry
coating.
[0020] Particles that result in a film with poor interlaminar
strength have good to excellent basal cleavage. The coating of the
present invention comprises particles from the class preferably
comprised of phyllosilicates, which have rings of tetrahedrons
linked by shared oxygens to other rings in a two dimensional plane
that produce a sheet-like structure. Layers of weakly bonded
cations, often having water molecules and other neutral atoms or
molecules trapped between them, typically connect the sheet
structures.
[0021] The particles used by the present invention are
characterized as being substantially flat, platy, and displaying
good to perfect basal cleavage. Cleavage is the splitting or
tendency of a crystal to split along definite crystalline planes to
produce substantially planar surfaces. The quality of the cleavage
plane is expressed with the terms perfect, good (well defined, but
not completely even) and poor (difficult to recognize). Cleavage
resulting in one non-parallel cleavage plane is called basal
cleavage. Basal cleavage is a type of cleavage across a horizontal
plane of a mineral by its base or top and bottom closing points.
Minerals with good to perfect basal cleavage can be peeled which is
the desired function on the particles for the present
invention.
[0022] Particles meeting this criterion include the minerals of the
mica family, which are all characterized by sheets of silicate.
Other preferred particles include graphite, magnesium silicate,
magnesium sulfite, clays, and crystals intergrown with mica and
clay layers forming a composite crystal.
[0023] Specific examples include but are not limited to:
[0024] Allophane (Hydrated Aluminum Silicate);
[0025] Apophyllite (Hydrated Potassium Sodium Calcium Silicate
Hydroxide Fluoride);
[0026] Bannisterite (Hydrated Potassium Calcium Manganese Iron Zinc
Aluminum Silicate Hydroxide);
[0027] Carletonite (Hydrated Potassium Sodium Calcium Silicate
Carbonate Hydroxide Fluoride);
[0028] Cavansite (Hydrated Calcium Vanadate Silicate);
[0029] Chrysocolla (Hydrated Copper Aluminum Hydrogen Silicate
Hydroxide);
[0030] Baileychlore (Zinc Iron Aluminum Magnesium Silicate
Hydroxide);
[0031] Chamosite (Iron Magnesium Aluminum Silicate Hydroxide
Oxide); Chlorite;
[0032] Clinochlore (Iron Magnesium Aluminum Silicate
Hydroxide);
[0033] Cookeite (Lithium Aluminum Silicate Hydroxide);
[0034] Nimite (Nickel Magnesium Iron Aluminum Silicate
Hydroxide);
[0035] Pennantite (Manganese Aluminum Silicate Hydroxide);
[0036] Penninite (Iron Magnesium Aluminum Silicate Hydroxide);
[0037] Sudoite (Magnesium Aluminum Iron Silicate Hydroxide);
[0038] Glauconite (Potassium Sodium Iron Aluminum Magnesium
Silicate Hydroxide);
[0039] Illite (Hydrated Potassium Aluminum Magnesium Iron Silicate
Hydroxide);
[0040] Kaolinite (Aluminum Silicate Hydroxide);
[0041] Montmorillonite (Hydrated Sodium Calcium Aluminum Magnesium
Silicate Hydroxide);
[0042] Palygorskite (Hydrated Magnesium Aluminum Silicate
Hydroxide);
[0043] Pyrophyllite (Aluminum Silicate Hydroxide);
[0044] Sauconite (Hydrated Sodium Zinc Aluminum Silicate
Hydroxide);
[0045] Talc (Magnesium Silicate Hydroxide);
[0046] Vermiculite (Hydrated Magnesium Iron Aluminum Silicate
Hydroxide);
[0047] Delhayelite (Hydrated Sodium Potassium Calcium Aluminum
Silicate Chloride Fluoride Sulfate);
[0048] Elpidite (Hydrated Sodium Zirconium Silicate);
[0049] Fedorite (Hydrated Potassium Sodium Calcium Silicate
Hydroxide Fluoride);
[0050] Franklinfurnaceite (Calcium Iron Aluminum Manganese Zinc
Silicate Hydroxide);
[0051] Franklinphilite (Hydrated Potassium Manganese Aluminum
Silicate,)
[0052] Gonyerite (Manganese Magnesium Iron Silicate Hydroxide);
[0053] Gyolite (Hydrated Calcium Silicate Hydroxide);
[0054] Leucosphenite (Hydrated Barium Sodium Titanium
Boro-silicate);
[0055] The Mica Group:
[0056] Biotite (Potassium Iron Magnesium Aluminum Silicate
Hydroxide Fluoride);
[0057] Lepidolite (Potassium Lithium Aluminum Silicate Hydroxide
Fluoride);
[0058] Muscovite (Potassium Aluminum Silicate Hydroxide
Fluoride);
[0059] Paragonite (Sodium Aluminum Silicate Hydroxide);
[0060] Phlogopite (Potassium Magnesium Aluminum Silicate Hydroxide;
Fluoride) and
[0061] Zinnwaldite (Potassium Lithium Aluminum Silicate Hydroxide
Fluoride).
[0062] Minehillite (Hydrated Potassium Sodium Calcium Zinc Aluminum
Silicate Hydroxide);
[0063] Nordite (Cerium Lanthanum Strontium Calcium Sodium Manganese
Zinc Magnesium Silicate);
[0064] Pentagonite (Hydrated Calcium Vanadate Silicate);
[0065] Petalite (Lithium Aluminum Silicate);
[0066] Prehnite (Calcium Aluminum Silicate Hydroxide);
[0067] Rhodesite (Hydrated Calcium Sodium Potassium Silicate);
and
[0068] Sanfomite (Barium Silicate);
[0069] Antigorite (Magnesium Iron Silicate Hydroxide);
[0070] Clinochrysotile (Magnesium Silicate Hydroxide);
[0071] Lizardite (Magnesium Silicate Hydroxide);
[0072] Orthochrysotile (Magnesium Silicate Hydroxide);
[0073] Serpentine (Iron Magnesium Silicate Hydroxide);
[0074] Wickenburgite (Hydrated Lead Calcium Aluminum Silicate);
and
[0075] Zeophyllite (Hydrated Calcium Silicate Hydroxide
Fluoride).
[0076] The particles mentioned above all meet a further
requirement. That is, the particles must be capable of forming a
continuous film when applied as a dispersion. The dispersion, for
economic and environmental reasons, is preferably an aqueous
dispersion. A dispersant may or may not be utilized to aid
dispersing of the particles.
[0077] The present invention encompasses the utilization of the
aforementioned coating on all or a portion of a surface of the
shingles. The invention is therefore embodied in terms of single
ply, multi-ply laminated shingles and roll roofing. Optimum
results, in terms of application and material costs, is obtained
when the coating is applied to the "pressure point" portion of the
laminate shingle 1. The pressure point, generally defined above, is
at, and immediately above and below the top edge of the posterior
layer where that top edge overlaps the bottom portion of headlap
portion of the anterior layer. This pressure point is generally
denoted by reference numeral 6 in FIG. 2. For roll roofing it is
preferred to coat the entire back side. The coating should be
applied to the surface of a shingle that is in contact with the
shingle above or below it when stacked. That is, shingles may be
stacked front surface-to-front surface, back surface-to-back
surface or front surface-to-back surface, in each case the coating
is applied to the surfaces in contact with the next shingle when
stacked. Preferably, the coating is applied to the exposed asphalt
surface in contact with either a granular surface or another
exposed asphalt surface.
[0078] Although the invention is independent of any theory
explaining its effectiveness, it is theorized that sticking between
adjacent shingles in a stack occurs principally at the hump in the
region where the top of the posterior layer is bonded to the bottom
of the headlap region of the anterior layer. This is where
thickness of the shingle changes from two layers to one layer,
producing a sharp. Pressure is greatest in the stack at this
location. As such, it is at this point where adhesion between
shingles is most apt to occur. Thus, this region is where
application of a release coating, to prevent adhesion, is most
preferred.
[0079] It is further theorized that the effectiveness of the
release coating is predicated upon the continuous film of particles
having poor interlaminar strength. These particles peel away from
each other or are easily fractured, significantly reducing the
force required to separate adjacent shingles from each other. Thus
this coating can also be applied to roll roofing to prevent
sticking in the roll configuration.
[0080] The self-seal adhesive embodiment of the present invention
involves applying the release coating comprising a continuous film
of solid particles having poor interlaminar strength to a roofing
shingle with a self-seal adhesive. Often, roofing shingles include
an adhesive applied to its bottom surface that provides sealing of
the shingle to an underlayment, sheathing or other shingle. The
coating of the present invention can be applied to the surface of a
shingle in contact with the self-seal adhesive prior to packaging
to prevent sticking of these shingles in bundles and stacked on
pallets. That is, the coating is applied to the front surface or
back surface of a shingle that is in contact with the self-seal
adhesive of another shingle when bundled or stacked.
[0081] The roofing shingle stack aspect of the present invention
involves stacking of the aforementioned roofing shingles one atop
another such that the top surface of each shingle faces the bottom
surface of its adjacent shingle. As stated above, a plurality of
shingles are piled atop one another to from a bundle. In a
preferred embodiment, 20 to 25 roofing shingles constitute a
bundle. Seven to ten of these bundles can then be stacked on top of
each other on a pallet.
[0082] A roofing shingle is typically manufactured using an
apparatus to impregnate a glass mat with a waterproofing compound
such as asphalt. Subsequently, one surface can be covered with an
adhesive material to which mineral granules are adhered to create a
weather surface. In a laminated shingle, the mineral granule coated
shingle material is cut into a plurality of anterior layers and
posterior layers. Typically the anterior layers comprise a headlap
portion and a butt portion. The butt portion thereof can comprise
tabs with spaces between these tabs. The spaces and tabs are
dimensioned so as to permit pairs of overlay portions to be cut
with the tabs thereof in an interleaved configuration. The layers
are subsequently laminated together. This and other similar methods
known by those in the art are used to manufacture roofing
shingles.
[0083] A laminating adhesive applicating station is used to
laminate the layers during manufacturing. The anterior layer and
posterior layer are brought together after a laminating adhesive is
applied, thus adhering them. A heat activatable self-seal adhesive
may be applied during manufacture to the surfaces of the shingles
to seal down the shingle when part of the completed roof shingle
structure. Subsequently, shingles are collected stacked front
surface-to-front surface, back surface-to-back surface or front
surface-to-back surface to form a bundle and palletized for
shipment.
[0084] The release coating of the present invention may be applied
to the portion of a shingle that contacts the heat activatable
adhesive material used to seal shingles down during a roof
installation. This substantially prevents the sticking of this self
seal material during its stacking, storing and shipping.
[0085] Also during manufacture, the release coating of the present
invention can be applied to the exposed bottom surfaces of the
shingles or more preferably at the described pressure points to
prevent sticking. The coating is preferably applied by spraying the
coating onto the desired location of the shingle and providing for
a drying period. Other methods include brushing or wiping the
coating on, dipping the shingle in the suspension, or other methods
known in the art.
[0086] The following examples are provided to illustrate the scope
of the present invention. Because of these examples are given for
illustrative purposes only, the present invention should not be
deemed limited thereto.
COMPARATIVE EXAMPLE 1
[0087] An example was designed to emulate the sticking together of
roofing shingles that occurs when roofing shingles are stacked
together in warm temperatures. In this example, a first stack of
unmodified roofing shingles measuring 7 inches by 5 inches with the
top edge of posterior layer lined up in the middle of the sample
going along the 7 inch side was prepared. A second stack of
identically sized roofing shingles but wherein the top edge of the
posterior layer lined up in the middle of the sample going along
the 5 inch side was also prepared. The shingles in each stack were
disposed such that the top surface of each shingle was in contact
with the bottom surface of the adjoining shingle. The two stacks
were thereupon crosslaced by placing the two stacks together.
[0088] The crosslaced stack was placed in an oven maintained at
165.degree. F. with a 50 lb. weight on its top. The samples were
removed from the oven after 16 hours. After the sample cooled to
ambient temperature, a wood workers clamp clamped a corner of the
top samples. A spring loaded, hand held weighing scale with a hook
at its end, hooked the clamp and the force required to pull a
shingle from the remainder of the stack was measured in pounds.
[0089] A series of 11 such separations was conducted. An average of
7.55 lbs., with a standard deviation of 1.7 lbs., was required to
separate these non-treated roofing shingles.
COMPARATIVE EXAMPLE 2
[0090] Comparative Example 1 was identically repeated but for the
substitution of roofing shingles in which the pressure point
portion of the bottom surface of the shingle was covered with tape
as typically done in the industry. The tape used was polyester.
[0091] A similar series of 11 separations was conducted. An average
of 4.98 lbs. with a standard deviation of 2.01 lbs., was required
to separate a single roofing shingle from the stack.
EXAMPLE 1
[0092] Comparative Example 1 was identically reproduced but for the
application on the pressure point portion of the bottom side of the
shingles of a coating of Nytal.RTM. 100 talc. The dilution ratio of
the release coating was five parts water to one part Nytal.
[0093] The average force required to separate the 11 roofing
shingles was 7.69 lbs. with a standard deviation of 3.74 lbs.
EXAMPLES 2-6
[0094] Example 1 was reproduced except that the coating of that
example was replaced with Graphite 100.RTM. synthetic graphite in
Example 2; Microlite.RTM. vemiculite in Example 3; Desulco.RTM.
graphite in Example 4; Vantal.RTM. 6H magnesium silicate in Example
5; and Nytal.RTM.400 talc in Example 6.
[0095] Each example involved 11 roofing shingle separations.
* * * * *