Note: Descriptions are shown in the official language in which they were submitted.
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File number: 3008-087
Revision: as filed
Date: January 24, 2011
RUBBERIZED ROOF UNDERLAYMENT
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims the benefits of priority
of commonly
assigned United States Patent Application no. 12/692,084, entitled "Rubberized
Roof
Underlayment" and filed at the United States Patent Office on January 22,
2010.
TECHNICAL FIELD
[0002] The present invention relates to roof underlayments and more
particularly, to
=
heavyweight and lightweight underlayment products which utilizes a rubberized
asphalt layer.
BACKGROUND INFORMATION
[0003] An underlayment material is commonly used in a number of roofmg
applications as well as other underlayment situations. The typical product
utilized in roofing
underlayment is commonly referred to as "tar" of "felt" paper. The traditional
"tar paper" is an
asphalt impregnated paper product which is sold in a roll; unrolled on a roof;
cut to length; and
fastened to the roof utilizing staples or nails. Although tar paper is
inexpensive, it does not seal
nail holes through the paper and thus does not prevent water infiltration. In
addition, once the
felt is rolled out, it absorbs water and once wet, it wrinkles and expands,
and must be allowed to
dry out before covering with shingles. Other prior art shingle underlayment
products also suffer
from the same problems.
[0004] Accordingly, what is needed are generally low cost,
heavyweight or
lightweight, dimensionally stable underlayment products on which the installer
can walk,
without sticking or slipping, which will not slide underfoot and which will
cold flow and/or
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File number: 3008-087
Revision: as filed
Date: January 24, 2011
elongate and recover to seal nail holes and other punctures. In addition, such
products should be
dimensionally stable, resist tearing, non-adhesive to other layers, and
provide hot and cold
flexibility.
SUMMARY
[0005] The present invention features novel underlayment products which
will be
relatively inexpensive and replace prior art products such as "tar paper" or
"felt paper". The
present invention provides underlayment products with a top surface that can
be walked on and
will not slide under foot, and wherein the products will not stick to
themselves or the roof. In
addition, the present invention has "cold" flow properties which allow it to
"repair" or "heal"
itself to thereby reseal around nail or puncture holes and also elongate and
recover around
punctures.
[0006] In accordance with one embodiment of the present invention,
the
underlayment includes an underlayment membrane comprising a fibrous mat having
an upper
surface and a lower surface. An elastomeric asphalt coating is applied to the
lower surface of the
fibrous mat and at least partially or fully infiltrates and saturates the
fibrous mat. Next, an
oxidized asphalt coating is applied to both the upper and lower surfaces of
the fibrous mat,
thereby essentially encapsulating the fibrous mat.
[0007] The underlayment membrane may further include a release
coating applied to
the oxidized asphalt coating on either the upper and/or lower surface of the
fibrous mat. The
release coating includes, in one embodiment, a talc/water coating but may
alternatively include
granule particles applied proximate at least the oxidized asphalt coating
proximate said upper
surface of said fibrous mat.
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File number: 3008-087
Revision: as filed
Date: January 24,2011
100081 The release coating may include a polymeric coating applied on
at least the
upper surface of the fibrous mat while the polymeric coating may be provided
with a coating of
finally-ground mineral, such as talc and finely-ground granules.
[0009] In the preferred embodiment, the rubberized asphalt coating
which is applied
from the bottom of the mat and partially or fully infiltrates the fibrous mat
includes
approximately 48% flux asphalt, 2% radial SBS rubber and 50% filler material
while the fibrous
mat includes fibers selected from the group consisting of polyesters,
polypropylenes and
fiberglass. The coating may, however, be provided having a range a ingredients
including, but
not limited to 0.5% to 12% radial or linear rubber or polymer; 0-70% filler;
and 48-98% asphalt
including 0-70% oxidized asphalt. The filler affects the walkability of the
outer surface. If the
filler content is too low such that a higher asphalt percentage exists, the
product would be sticky.
The high filler content and/or talc layer prevents sticking. In addition, the
filler also brings down
the price of the finished product.
[0010] Adding an oxidized asphalt layer on both the top and bottom
layer of the mat
makes the product more usable in hotter conditions providing a higher
resistance to softening by
providing an asphalt with a higher Ring and Ball softening point temperature.
It also makes the
product not stick in three ways: 1) foot traffic 2) the roof deck and 3) in
the roll form.
[0011] The rubber or other elastomer in the elastomeric layer may be
linear or radial
rubber although with linear SBS rubber, as much as 10 or 12 percent may be
required whereas
with radial SBS rubber, 0.5 to 6% will generally suffice.
[0012] In the preferred embodiment, the talc coating is suspended in
a water-based,
polymer emulsion. Examples of the polymer include styrene, acrylic and the
polyurethane.
When it dries, the polymer forms a film which helps hold the talc to the
asphalt so that the talc
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File number: 3008-087
Revision: as filed
Date: January 24,2011
does not fall off or interfere with any overlap or bonding areas. Loose talc
is a slip problem.
Although a talc acrylic layer is preferred as the method to prevent sticking,
a water or other
based polymer may be applied and may be sufficient, as would be a plastic
film.
100131 In accordance with another embodiment of the present
invention, the
underlayment includes an underlayment membrane comprising a fibrous mat having
an upper
surface and a lower surface. An elastomeric asphalt coating is applied to the
upper surface of the
fibrous mat and at least partially or fully infiltrates and saturates the
fibrous mat. Next, an
oxidized asphalt coating is applied in one embodiment to the lower surface of
the fibrous mat.
10014] The underlayment membrane may further include a release
coating applied to
the oxidized asphalt coating on the lower surface of the fibrous mat. In an
alternate embodiment
without the oxidized asphalt layer, the release coating is applied to the
lower surface of the
fibrous mat. The release coating includes, in one embodiment, a talc/polymer
coating.
100151 The underlayment membrane may further include a split release
facing having
a high traction surface that is applied to the rubberized asphalt coating on
the upper surface of
the fibrous mat. The split release facing having a high traction surface, in
one embodiment,
provides a selvedge edge and includes a plurality of separate and distinct
regions bearing a high
traction polymer blend.
100161 In the preferred lightweight underlayment embodiment, the
rubberized asphalt
coating which is applied onto the top of the mat and partially or fully
infiltrates the fibrous mat
includes approximately 48% flux asphalt, 2% radial SBS rubber and 50% filler
material while
the fibrous mat includes fibers selected from the group consisting of
polyesters, polypropylenes
and fiberglass. The coating may, however, be provided having a range a
ingredients including,
but not limited to 0.5% to 12% radial or linear rubber or polymer, 0-70%
filler; and 48-98%
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asphalt including 0-70% oxidized asphalt. The filler affects the walkability
of the outer
surface. If the filler content is too low such that a higher asphalt
percentage exists, the product
would be sticky. The high filler content and/or talc layer prevents sticking.
In addition, the
filler also brings down the price of the finished product.
[0017] The rubber or other elastomer in the elastomeric layer may be
linear or radial
rubber although with linear SBS rubber, as much as 10 or 12 percent may be
required whereas
with radial SBS rubber, 0.5 to 6% will generally suffice.
[0017a] In one aspect, there is provided an underlayment membrane
comprising: a
fibrous mat having an upper surface and a lower surface; a rubberized asphalt
coating applied to
the upper surface of the fibrous mat and extending at least partially into
said fibrous mat, said
rubberized asphalt coating comprising 0.5% to 12% radial or linear rubber or
polymer, 0% to
70% filler, and 48% to 98% asphalt; an oxidized asphalt coating applied to
said lower surface of
said fibrous mat; and a split facer layer having first and second coplanar
segments applied to
said rubberized asphalt coating applied to the upper surface of the fibrous
mat to define a top
portion of the underlayment, the first segment comprising a removable selvedge
edge segment
to allow partial overlapping of successive courses during installation and the
second segment
comprising a plurality of spaced apart and distinct traction surface regions
applied to an upper
side of the second segment of the facer layer that are softer than a material
substrate of the facer
layer so as to reduce if not eliminate applicator slippage during
installation.
[0018] It is important to note that the present invention is not intended
to be limited
to a system or method which must satisfy one or more of any stated objects or
features of the
invention. It is also important to note that the present invention is not
limited to the
preferred, exemplary, or primary embodiment(s) described herein. Modifications
and
substitutions by one of ordinary skill in the art are considered to be within
the scope of the
present invention, which is not to be limited except by allowed claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0019] These and other features and advantages of the present invention
will be better
understood by reading the following detailed description, taken together with
the drawings
wherein:
[0020] FIG. 1 is a schematic sectional view of the heavyweight underlayment
of the
present invention;
[0021] Fig. 2 is a schematic sectional view of the lightweight underlayment
of the
present invention;
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100221 Fig. 3 is a schematic top plan view of the lightweight
underlayment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
100231 The present invention features novel underlayment products
which will be
relatively inexpensive and replace prior art products such as "tar paper" or
"felt paper". The
present invention provides underlayment products with a top surface that can
be walked on and
will not slide under foot, and wherein the products will not stick to
themselves or the roof, In
addition, the present invention has "cold" flow properties and elongate and
recovery properties
which allow it to reseal around nail or puncture holes.
[0024] The heavyweight underlayment 10, Figure 1, in accordance with the
present
invention includes a fibrous mat 12 disposed in the center of the
underlayment. Examples of and
equivalents for the fibrous mat 12 are disclosed in US patent numbers
6,531,200 and 6,296,912
assigned to the assignee of the present invention.
[0025] The fibrous mat 12 is first coated proximate one side with a
rubberized asphalt
layer 14. The rubberized asphalt layer 14 typically comprises approximately 4%
rubber, 46%
flux asphalt and 50% filler, although various percentages may be provided.
These percentages
are approximate and those skilled in the art would understand that a deviation
from these
percentages is considered within the scope of the present invention.
100261 The rubberized asphalt layer 14 exhibits "cold flow" or "self-
healing"
properties by virtue of the inclusion of a relatively small percentage of
rubber. Accordingly,
when the underlayment 10 is punctured, such as by a nail, the rubberized
asphalt layer 14 will
"self-heal" around the puncture thereby resealing around the puncture. This is
particularly
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important when underlayment is used under roofing tile in which case the tiles
are fastened to the
roof using "ring" nails which create a hole which is larger than the nail
shank itself. In this case,
the rubber in the underlayment will actually stick to the ridges in the nail
shank and stretch
around the nail shank thereby creating a generally watertight seal around the
shank of the nail.
Without the "self-healing" properties of the rubberized asphalt layer 14 of
the underlayment 10
of the present invention, persistent roof leaks abound.
[0027] In the preferred embodiment, the rubber includes "SBS" radial
rubber
although linear rubber, in a higher content percentage, would also be
acceptable. The SBS
rubber is mixed with the flux asphalt using a high shear mill, as is well
known in the art. The
rubberized asphalt layer 14 is applied to only one side of the fibrous mat 12.
This one-sided
application serves to vaporize and drive out any moisture trapped in the
fibrous mat 12.
Examples of how to coat fibrous mats on one side can be found in the two
referenced United
States patents 6,531,200 and 6,296,912.
[0028] The rubberized asphalt layer 14 infiltrates at least
partially but also can extend
fully into the central region 13 of fibrous mat 12.
[0029] After the application of the rubberized asphalt layer 14 to
one side of the
fibrous mat 12, oxidized asphalt layers 16a and 16b are applied; with oxidized
asphalt layer 16a
applied over the rubberized asphalt layer 14 while the oxidized asphalt layer
16b is applied
directly to the fibrous mat on the side opposite the rubberized asphalt layer
14. Accordingly, in
the preferred embodiment, the interface between the rubberized asphalt layer
14 and the oxidized
asphalt layer 16b will occur in region 13 of fibrous mat 12 and not proximate
or on the upper
surface 15 of fibrous mat 12. If the interface between the oxidized asphalt
layer 16b and the
rubberized asphalt layer 14 is proximate or at the upper surface 15 of fibrous
mat 12, the
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oxidized asphalt layer 16 exhibits a tendency to slip or shear away from the
rubberized asphalt
layer particularly due to foot traffic when the product was installed on a hot
roof. This presents a
dangerous situation and also one where the product would have a tendency to
adhere to an
adjacent layer.
[0030] As is well known in the prior art, an oxidized asphalt layer
typically includes
approximately 50% oxidized asphalt and 50% filler. The oxidized asphalt layer
16b will become
the top surface of the underlayment 10. Since there is no rubberized asphalt
layer under the
oxidized asphalt layer 16b, anyone walking on this product will not slip given
the propensity of
oxidized asphalt layer to break away from the rubberized asphalt layer if the
rubberized asphalt
later were located directly beneath the top oxidized asphalt layer and not
within the fibrous mat
12.
[0031] Finally, the top and bottom of the underlayment 10 is coated with a
talc acrylic
layer 18. The talc acrylic layer 18 provides an additional coating to the
oxidized asphalt layers,
filling in any voids that are present and preventing the membrane from
sticking to itself when
rolled. The talc layer 18 is applied as a talc/water or talc polymer mixture
as described, for
example, in US patent number 6,531,200. In an alternative embodiment, talc
layer 18a may be
replaced with or include granular particles.
[0032] The lightweight underlayment 30, Figure 2, in accordance with the
present
invention includes a fibrous mat 32 disposed in the center of the
underlayment. Examples of and
equivalents for the fibrous mat 32 are disclosed in US patent numbers
6,531,200 and 6,296,912.
The fibrous mat 32 is first coated proximate its upper side with a rubberized
asphalt layer 34.
The rubberized asphalt layer 34 typically comprises approximately 4% rubber,
46% flux asphalt
and 50% filler, although various percentages may be provided. These
percentages are
approximate and those skilled in the art would understand that a deviation
from these
percentages is considered within the scope of the present invention.
[0033] The rubberized asphalt layer 34 exhibits "cold flow" or "self-
healing"
properties by virtue of the inclusion of a relatively small percentage of
rubber. Accordingly, when
the underlayment 30 is punctured, such as by a nail, the rubberized asphalt
layer 34 will "self-heal"
around the puncture thereby resealing around the puncture. This is
particularly important as
discussed above when underlayment is used under roofing tile in which case the
tiles are fastened
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to the roof using "ring" nails which create a hole or puncture which is larger
than the nail shank
itself.
[0034] In the preferred embodiment, the rubber includes "SBS" radial
rubber although
linear rubber, in a higher content percentage, would also be acceptable and is
contemplated. The
SBS rubber is mixed with the flux asphalt using a high shear mill, as is well
known in the art.
The rubberized asphalt layer 34 as for the embodiment 10 described hereinabove
is applied to
only one side of the fibrous mat 32, which serves to vaporize and drive out
any moisture trapped
in the fibrous mat 32. Examples of how to coat fibrous mats on one side can be
found in the two
referenced United States patents.
[0035] The rubberized asphalt layer 34 infiltrates at least partially but
also can extend fully
into the central region 36 of fibrous mat 32.
[0036] After the application of the rubberized asphalt layer 34 to the top
of the fibrous mat
32, an oxidized asphalt layer 38 in one embodiment is applied directly to the
fibrous mat underside
opposite the rubberized asphalt layer 34. As is well known in the prior art,
an oxidized asphalt layer
typically includes approximately 50% oxidized asphalt and 50% filler.
[0037] The bottom of the underlayment 30 is coated with a talc acrylic
layer 40. The talc
acrylic layer 40 provides an additional coating to the oxidized asphalt layer
34, filling in any voids
that are present and preventing the membrane from sticking to itself when
rolled. In an alternate
embodiment, the oxidized asphalt layer 38 is not used, and the talc acrylic
layer 40 is applied directly
to the underside of the fibrous mat 32. The talc acrylic layer 40 in either
embodiment is applied as a
talc/water or talc polymer mixture as described, for example, in US patent
number 6,531,200.
[0038] The top of the underlayment 30 is coated with a split release facer
having high
traction surface generally designated 42. As best seen in Fig. 3, the facer 42
is segmented to include a
first removable selvedge edge segment 44 and a second segment providing a high
traction surface
schematically illustrated at 46. As will be readily appreciated by those of
skill in the art, removal of
the selvedge edge segment 44 exposes the adhesive surface of the rubberized
asphalt, which
provides adhesion of successive courses to each other, the exposed rubberized
adhesive edge of
one course to the talc/polymer layer of another partially overlapping course.
Any suitable facer
adapted to provide a removable selvedge edge while preventing or reducing self-
adhesion when
rolled, such as facers provided with partially overlapping edge portions, or
with underlay strips as
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in USP 5,916,654 to Phillips et al., or with pull strings as in USP 6,235,364
to Schaughency et al.,
or laser slit as disclosed in commonly assigned and co-pending United States
utility patent
application serial number 11/749,360, filed May 16, 2007 and published as US
2008/0286517,
entitled -Self-adhesive Product having a Laser Slit Release Liner and Method
of Making Same",
may be employed.
[0039] The high traction portion 46 preferably is formed of one or more
separate and distinct
polymer regions disposed on the upper side of the facer 42 that is softer than
the material substratum
of the facer 42 to provide a high traction surface. The high traction polymer
regions may be
arranged in any suitable pattern, such as strips, or dots. In one presently
preferred embodiment, the
high traction polymer is arranged in spaced-apart longitudinally extending
strips on a .5 mil or .25
mil polyethylene film and is fabricated of a blend comprising a mixture of low
molecular weight
polyethylene and amorphous polyolefin, as disclosed in commonly assigned USP
6,385,934 to
Zickell et al.
[0040] Accordingly, the present invention provides novel and useful
underlayment
products which can be used under many roofing or other materials as a
substrate or underlayment,
which serves to self-seal around any penetrations such as nails and the like.
[0041] As mentioned above, the present invention is not intended to
be limited to a
system or method which must satisfy one or more of any stated or implied
object or feature of the
invention and should not be limited to the preferred, exemplary, or primary
embodiment(s) described
herein. Modifications and substitutions by one of ordinary skill in the art
are considered to be within
the scope of the present invention, which is not to be limited except by the
allowed claims and their
legal equivalents.
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