U.S. patent application number 14/652989 was filed with the patent office on 2015-11-26 for roofing seam with reactive adhesive.
This patent application is currently assigned to ADCO PRODUCTS, LLC. The applicant listed for this patent is ADCO PRODUCTS, INC.. Invention is credited to John William Miller, Robert Reel, Paul Snowwhite.
Application Number | 20150337534 14/652989 |
Document ID | / |
Family ID | 50934999 |
Filed Date | 2015-11-26 |
United States Patent
Application |
20150337534 |
Kind Code |
A1 |
Miller; John William ; et
al. |
November 26, 2015 |
ROOFING SEAM WITH REACTIVE ADHESIVE
Abstract
A roofing system includes a first membrane, second membrane and
an adhesive layer with no VOC content. A portion of the second
membrane overlaps a portion of the first membrane. The adhesive
layer directly adheres the overlapping portions of the first
membrane and the second membrane together.
Inventors: |
Miller; John William;
(Hudson, MI) ; Snowwhite; Paul; (Dexter, MI)
; Reel; Robert; (Ann Arbor, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ADCO PRODUCTS, INC. |
Michigan Center |
MI |
US |
|
|
Assignee: |
ADCO PRODUCTS, LLC
Michigan Center
MI
|
Family ID: |
50934999 |
Appl. No.: |
14/652989 |
Filed: |
December 13, 2013 |
PCT Filed: |
December 13, 2013 |
PCT NO: |
PCT/US13/75079 |
371 Date: |
June 17, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61737356 |
Dec 14, 2012 |
|
|
|
Current U.S.
Class: |
52/309.3 ;
52/516 |
Current CPC
Class: |
C08G 18/10 20130101;
C08G 18/4211 20130101; C08G 18/10 20130101; E04D 5/08 20130101;
E04D 5/148 20130101; C08G 18/4825 20130101; C08G 18/40 20130101;
C08G 18/4829 20130101; C09J 175/04 20130101 |
International
Class: |
E04D 5/14 20060101
E04D005/14; E04D 5/08 20060101 E04D005/08 |
Claims
1. A roofing system comprising: a first membrane: a second
membrane, a portion of the second membrane overlapping a portion of
the first membrane; and an adhesive layer directly adhering the
overlapping portions of the first membrane and the second membrane
together, the adhesive layer having no VOC content.
2. The roofing system of claim 1 wherein the adhesive layer is the
product of mixing an A side composition and a B side composition
together.
3. The roofing system of claim 2 wherein the B side composition
includes a polyol, a catalyst and a chain extender, and wherein the
A side composition includes at least one of a polyurethane
prepolymer and a diisocyanate.
4. The roofing system of claim 3 further comprising at least one
adhesion promoter present in at least one of the A side and the B
side.
5. The roofing system of claim 4 wherein the at least one adhesion
promoter is selected from the group consisting of chlorinated
paraffins and chlorinated polyolefins.
6. The roofing system of claim 4 wherein the at least one adhesion
promoter includes at least two adhesion promoters each selected
from the group consisting of chlorinated paraffins and chlorinated
polyolefins.
7. The roofing system of claim 2 wherein a ratio of isocyanate
groups in the A side to hydroxyl groups in the B side is greater
than 1.5:1.
8. The roofing system of claim 1 wherein the adhesive layer further
includes a blowing agent.
9. The roofing system of claim 1 wherein the first membrane and the
second membrane are unprimed prior to the application of the
adhesive layer.
10. The roofing system of claim 1 wherein the first membrane and
the second membrane are sheets of EPDM.
11. The roofing system of claim 1 wherein the adhesive layer is a
one-part composition including at least one poyol, at least one
moisture cure prepolymer, and at least one catalyst.
12. A composite roof structure comprising: a roofing substrate
having a substrate surface; a first roofing membrane having a
membrane surface that opposes the substrate surface of the roofing
substrate; a second roofing membrane having a membrane surface that
opposes the substrate surface of the roofing substrate, a portion
of the second roofing membrane overlapping a portion of the first
roofing membrane and an adhesive layer directly adhering to the
substrate surface of the roofing substrate and directly adhering to
the membrane surface of the first roofing membrane and to the
membrane surface of the second roofing membrane; and a splice
adhesive layer directly adhering the overlapping portions of the
first roofing membrane and the second roofing membrane together,
the splice adhesive layer having no VOC content.
13. The roofing structure of claim 12 wherein the adhesive layer
and the splice adhesive layer of made of the same adhesive
composition.
14. The roofing structure of claim 12 wherein the adhesive layer
and the splice adhesive layer are the product of mixing an A side
composition and a B side composition together.
15. The roofing structure of claim 14 wherein the B side
composition includes a polyol, a catalyst and a chain extender, and
wherein the A side composition includes at least one of a
polyurethane prepolymer and a diisocyanate.
16. The roofing structure of claim 15 further comprising at least
one adhesion promoter present in at least one of the A side and the
B side.
17. The roofing structure of claim 16 wherein the at least one
adhesion promoter is selected from the group consisting of
chlorinated paraffins and chlorinated polyolefins.
18. The roofing structure of claim 16 wherein the at least one
adhesion promoter includes at least two adhesion promoters each
selected from the group consisting of chlorinated paraffins and
chlorinated polyolefins.
19. The roofing structure of claim 14 wherein a ratio of isocyanate
groups in the A side to hydroxyl groups in the B side is greater
than 1.5:1.
20. The roofing structure of claim 12 wherein the first roofing
membrane and the second roofing membrane are unprimed prior to the
application of the splice adhesive layer.
21. The roofing structure of claim 12 wherein the first roofing
membrane and the second roofing membrane are sheets of EPDM.
22. The roofing structure of claim 12 wherein the adhesive layer
and the splice adhesive layer are a one-part composition including
at least one poyol, at least one moisture cure prepolymer, and at
least one catalyst.
Description
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 61/737,356, filed on Dec. 14, 2012 and PCT
Application No. PCT/US13/75079, filed on Dec. 13, 2013. The
contents of the above applications are incorporated herein by
reference in its entirety.
FIELD
[0002] The present invention relates to one-part and two-part
adhesives with low volatile organic content for use roofing
seams.
BACKGROUND
[0003] In many roofing applications, for example in large, flat
commercial roof decks, the roofing substrate is a concrete, light
weight concrete, wood, gypsum, wood fiber or steel roof deck. The
roofing membrane is used to seal and protect the roof deck from
environmental weather conditions and is placed over insulation
boards, which provide insulative qualities. The insulation boards
are typically secured to the roofing substrate or roof deck via an
adhesive composition or fasteners. The roofing membrane may be made
of various materials, such as polymeric materials including EPDM
(ethylene propylene diene M-rubber), Mod Bit (Modified Bitumen),
TPO (thermoplastic polyolefin), or polyvinyl chloride (PVC). The
roofing membrane may also be a composite material that includes
EPDM or TPO. The roofing membrane is adhered overtop insulation
boards or panels using an adhesive composition such as mopping
asphalt (typically Type III or Type IV) or other conventional
adhesive compositions. Conventional adhesives normally are required
to be applied to both the roofing membrane and the substrate.
[0004] When the membrane sheets are applied to the substrate the
edges of adjacent membrane sheets are typically spliced together
with a seam tape. Prior to the application of the tape, a primer is
applied to the membrane sheets. Conventional primers contain high
levels of volatile organic compounds (VOC), and low VOC primers are
expensive.
[0005] Accordingly, there is a need in the art for splicing
adjacent membrane sheets together with adhesive compositions that
exhibit favorable properties, such as, for example, sufficient
adhesive strength, low to no VOC content, and are easily
applied.
SUMMARY
[0006] A roofing system includes a first membrane, second membrane
and an adhesive layer with no VOC content. A portion of the second
membrane overlaps a portion of the first membrane. The adhesive
layer directly adheres the overlapping portions of the first
membrane and the second membrane together.
[0007] Further features, advantages, and areas of applicability
will become apparent from the description provided herein. It
should be understood that the description and specific examples are
intended for purposes of illustration only and are not intended to
limit the scope of the present disclosure.
DRAWING
[0008] The drawing described herein is for illustration purposes
only and are not intended to limit the scope of the present
disclosure in any way. The components in the figure are not
necessarily to scale, emphasis instead being placed upon
illustrating the principles of the invention. In the drawing:
[0009] FIG. 1 shows a cross-sectional side view of overlapping
membranes adhered to a substrate with an adhesive composition in
accordance with the principles of the present invention.
DETAILED DESCRIPTION
[0010] The following description is merely exemplary in nature and
is not intended to limit the present disclosure, application, or
uses.
[0011] Referring now to FIG. 1, there is shown a roofing seam
implementing of adhesive compositions described below. The adhesive
composition can be a one-part adhesive, or the first and second
components of the adhesive composition are prepared and packaged
separately, and then combined in the proper ratio for application
at a job site. As shown in FIG. 1, in accordance with the
principles of the present invention, the adhesive composition 22 is
applied between the polymeric roofing material 20, such as, for
example, EPDM, and a roof-deck substrate 18. The adhesive
composition can be allowed to cure for a desired period of time at
a desired temperature to obtain optimum bond strength. The
overlapping sheets or membranes 20 may then be joined with a splice
adhesive 11 at the time the roofing material 20 is applied to the
substrate 18 or after the adhesive composition 22 is cured to form
a continuous membrane. The splice adhesive 11 can be made of the
same composition as the adhesive composition 22. The implementation
shown in FIG. 1 does not require the overlapping sheets to be
primed prior to the application of the splice adhesive 11. Further
the implementation does not require the use of a seam tape as
commonly employed to form a seal between the overlapping sheets 20,
since the strength of the seal between the overlapping sheets 20 is
as strong as the bond between the sheets 20 and the substrate 18
with the use of the adhesive composition 22. Note again that the
formation of the seam formed with the sheets 20 is primerless so
that the sheets do not need to be primed before joining the sheets
together to form the seam. Also, an additional tape layer is not
required to join the sheets together. Further note that the
implementation is not limited to the use of the adhesives described
below. For example, the primerless seam can be formed with other
technologies, such as, but not limited to, a polyurea or epoxy type
composition, or any other suitable adhesive composition.
[0012] In some implementations, the adhesive composition is either
a one-part or a two-part reactive adhesive composition. The
adhesive composition generally includes a polyol, a pre-polymer, a
catalyst, and may or may not contain an adhesion promoter.
[0013] The polyol may be any compound conventionally used in the
production of polyurethanes having at least one isocyanate-reactive
functionality. These polyols include glycols, diols, mono alcohols
or multi-functional alcohols. One exemplary polyol suitable with
the composition of the present invention includes an ortho
phthalate-diethylene glycol based aromatic polyester polyol
commercially available from Stepan under the designation STEPANPOL
PS-2352. Another exemplary polyol suitable with the composition of
the present invention includes a di-functional polyether diol
commercially available from Huntsman under the designations JEFFOL
PPG-1000 and JEFFOL PPG-2000. Another exemplary polyol suitable
with the present invention includes a multi-functional polyether
polyol commercially available from BASF under the designation
PLURACOL SG360. Chemical derivatives and combinations of polyols
may also be employed in the composition without departing from the
scope of the present invention. The polyol comprises from about 30%
to about 50% by weight of the composition.
[0014] The prepolymer or polymer precursor may be any polyurethane
prepolymer formed by combining an excess of diisocyanate with a
polyol to yield a diisocyanate prepolymer. The prepolymer reacts
like a diisocyanate but with several important differences. When
compared with the original diisocyanate, the prepolymer has a
greater molecular weight, a higher viscosity, a lower isocyanate
content by weight (% NCO), and a lower vapor pressure. One
exemplary prepolymer suitable with the composition of the present
invention includes a moisture cure prepolymer commercially
available from Huntsman under the designation RUBINATE 9272.
Another exemplary prepolymer suitable with the composition of the
present invention includes a 4,4'-MDI prepolymer commercially
available from Huntsman under the designation RUBINATE 1209.
Combinations of prepolymers and commercially available prepolymers
or modified prepolymers may also be employed in the composition
without departing from the scope of the present invention. In one
embodiment, the prepolymer comprises from about 30% to about 70% by
weight of the composition.
[0015] The catalyst may be a metal or an amine based urethane
catalyst. It is preferably amine based, more preferably a diazole,
and even more preferably an imidazole. One exemplary catalyst
suitable with the composition of the present invention includes
1-methylimidazole, commercially available from Air Products and
Chemicals, Inc. under the designation IMICURE AMI-1. A secondary
catalyst can also be used. An example includes a quaternary
ammonium salt, Dabco TMR-3, commercially available from Air
Products and Chemicals. Combinations of catalysts may also be
employed in the composition without departing from the scope of the
present invention. The catalyst comprises from about 0.5% to about
5% by weight of the composition.
[0016] The blowing agent may be reactive or non-reactive.
Non-reactive blowing agents include hydrocarbons and
hydrofluorocarbons. Reactive blowing agents react with the
isocyanate group which produces carbon dioxide. The carbon dioxide
generation produces cellular structure within the adhesive. The
application of the membrane will crush the adhesive thereby
releasing the generated carbon dioxide. Water is a commonly used
reactive blowing agent in two-part polyurethanes. When water is
included in the B side of a two-part polyurethane, the water reacts
with the A side components upon mixing of the A and B sides.
Additionally, water is not considered a VOC or solvent.
[0017] The adhesive composition may include adhesion promoters such
as chlorinated waxes, chlorinated paraffins or chlorinated
polyolefins. An example is Paroil 60H, commercially available from
Dover Chemicals.
[0018] The adhesive composition may further include other
additives, such as, for example, tackifiers, fillers, plasticizers,
surfactants, rheology modifiers, viscosity modifiers, and
thixotropic agents. Fillers, plasticizers, rheology modifiers,
surfactants, and thixotropic agents may be used to alter the liquid
viscosity to either or both of parts A and B, optimize mixing
properties during dispensing, enhance air entrainment, improve wet
out, and improve flow properties of the adhesive during
application. Examples of fillers include silica particles and talc.
Examples of plasticizers include process oils and phthalates.
Examples of rheology modifiers include organoclays, natural clays,
and fumed silica. An exemplary organoclay is CLAYTONE APA available
from Southern Clay Products. The surfactants may include silicone
based or non-silicone based compounds. Tackifiers may be added to
improve initial green strength and may be selected, for example,
from a group including polyterpenes, rosin esters, phenolic resins,
hydrocarbon resins, and hydrogenated resins.
[0019] The amount of the components included in the composition is
selected to balance tack, cure speed, and adhesion strength of the
adhesive. For example, the embodiments presented exhibit adhesive
tack when cured and the foam adhesive is substantially soft with a
low modulus. The low modulus allows for diffusion of the adhesion
promoter to the substrate surface and improves heat aged adhesive
strength.
[0020] The "A" side and "B" sides are mixed so that the ratio of
the reactive components, ie, ratio of "A" side isocyanate groups to
"B" side hydroxyl groups, is greater than 1.5:1. This ratio is also
known as the Isocyanate index and stoichiometrically one isocyanate
group reacts with one hydroxyl group. In several of the examples
presented below, this Isocyanate index and the prepolymer
incorporated combine to produce a soft, non-rigid adhesive.
[0021] The adhesive composition is prepared by mixing the
components prior to application on a substrate. In a one-part
adhesive configuration, the components are mixed prior to packaging
into a single container. The adhesive is then dispensed or
otherwise applied to the roofing substrate or the roofing membrane
and is cured in-situ via moisture cure. Due to the reactive nature
of the adhesive composition, the adhesive composition may be
applied in ribbon or bead method and may be applied to only one
side of the substrate or roofing membrane. Additionally, the
adhesive compositions provided herein are sprayable. In some of the
adhesive composition examples described below the sprayability of
the adhesive composition is facilitated using equipment that is
capable of modifying the viscosity of the adhesive through the
application of heat or like methods.
[0022] In a two-part adhesive configuration, the adhesive is formed
by combining two separate compositions or blends just prior to
application on the roofing substrate. The two parts include a "B
side" or resin side and an "A side" or prepolymer side. Each of the
sides is packaged separately and is mixed by an applicator prior to
applying on the roofing substrate. The A and B side components may
be packaged in several ways. For example, each may be stored in a
collapsible bag disposed within a box such as Cubitainer.RTM. by
Hedwin or Cheertainer.RTM. by CDF, stored in rigid containers such
as drums or barrels, paired in cylinders, or in flexible, fully
compressible structures such as collapsible tubes that dispense the
materials. In the example provided, the B side includes the polyol
and the catalyst and the A side includes the prepolymer. The
adhesive, once mixed, is dispensed or otherwise applied to the
roofing substrate or the roofing membrane to splice adjacent
membranes together. During mixing, and after mixing, the components
react to form a polyurethane adhesive having suitable physical
properties. Due to the reactive nature of the adhesive composition,
the adhesive composition may be applied in ribbon or bead method
and may be applied to only one side of the substrate or roofing
membrane. As noted above, the A Side and B Side components are
preferably mixed by an applicator just prior to being dispensed or
otherwise applied to the roofing substrate. Forms of application
include using a cartridge, using low pressure pumping of the two
components and mixing them with a static mixer, or using high
pressure tanks that are brought to about 500-1500 psi with an inert
dry gas, such as Nitrogen. In the latter form of application, the A
and B side materials are metered as two individual components and
brought together and mixed by high pressure impingement or by a
static mixer and then applied in a bead or ribbon form.
[0023] The "A" and "B" side components are generally mixed in a
ratio of 1:1 by volume, however the ratio may range from about 10:1
to about 1:10. During mixing, and after mixing, the A Side
components and B Side components react to form a polyurethane
adhesive having suitable physical properties. Preferably, the
adhesive composition is applied in discrete beads or ribbons
overtop the roofing substrate, such as the insulation boards or
roof deck or roofing membrane. Next, the roofing membrane is rolled
or otherwise positioned overtop of the adhesive composition and the
roofing substrate. Overlapping sheets as shown in FIG. 1 are then
joined together with the splice adhesive 11, which is typically the
same adhesive composition. The adhesive composition then cures and
secures the roofing membrane to the roofing substrate, as well as
securing adjacent roofing membranes together. Due to the
formulation of the adhesive composition of the present invention,
the roofing substrate and the roofing membrane may be untreated,
i.e., no primer or membrane fleece back is required to achieve the
desired adhesive strength. Therefore, no fleece backing or primer
needs to be applied during membrane production in the factory or
during membrane installation at the job site. As discussed earlier,
the overlapping membranes also do not need to be treated with a
primmer before applying the splice adhesive. Also, as mentioned
earlier the adhesive composition can be a one-part
configuration.
[0024] The adhesive compositions can have a low modulus of
elasticity. For example, the adhesive can have a modulus of about
121.5 psi. Similarly, the adhesive can also have soft and flexible
characteristics that promote mobility of the chlorinated paraffins
within the adhesive.
[0025] The method of adhering a "neat" EPDM roofing membrane to a
roof member as well as forming a seam between adjacent membranes
provides several advantages over existing methods. The present
method provides a VOC free application using curable chemistry
between two water-impervious membranes. Furthermore, the present
method does not require a fleece backing or priming to adhere the
EPDM roofing membrane to the roof member.
[0026] In various arrangements the two-part adhesive exhibits a
slow reaction initiation time to allow greater wet out of the
substrates for improved adhesion. Some imidazole structures
(permethylated nitrogen) act as latent catalysts and are more
effective after heat aging of the polymer. Other imidazole
structures (active hydrogen) produce blocked isocyanates that
become un-blocked with heat. Various two-part adhesives exhibit an
acceptable cure time of the adhesive which allows for enough green
strength to resist wind up-lift forces on a roof. (This improvement
is from polymer viscosity build and tensile strength increase.) The
two-part adhesive can exhibit an acceptable cure time of the
adhesive to lock down the membranes to allow normal activities on a
roof (This improvement is from polymer viscosity build and tensile
strength increase.) The two-part adhesive in some implementations
has an NCO to OH ratio resulting in a soft polymer with a modulus
of less than 500 psi and is tacky with a T-peel breakaway strength
of greater than 0.5 pli.
[0027] The two-part adhesive can contain an MDI isocyanate
pre-polymer having a high 2-4' content which exhibits a slow
reaction initiation time to allow greater wet out of the substrates
for improved adhesion. (This is due to a balance of 4-4' MDI with
2-4' MDI allowing for fast polymer formation from 4-4' and slower
reaction and good wet-out due to steric hindrance of the 2-4'.)
Certain two-part adhesives contain Di-ethanol amine or other
additives which disrupt the hard/soft segment blocks of the
polyurethane adhesive resulting in a soft polymer with good peel
strength. The two-part adhesives can contain an acid composition
that can alter the surface tension or chemistry of the adhesive or
membrane allowing for better wet out or creation of reactive sites
and improved adhesion.
[0028] In various arrangements, the adhesive compositions described
above may or may not include paraffins or other adhesion promoters.
Any of the compositions may include chain extenders such as, for
example, glycerin, di-ethylene glycol etc. for back end cure speed
improvements. The addition of glycerin or similar chemistries
provide a formulation that performs as a roofing adhesive over a
wide application temperature range. This allows sufficient we-out
time during the initiation of the reaction time to allow for
adhesive to the roofing substrate. Further, the formulation with
glycerin or similar chemistries exhibits acceptable completion of
reaction to make the membrane resistant to wind up-lift forces in a
timely manner. In certain compositions with glycerin or similar
chemistries, the application temperature range for these
compositions have a range from about 0.degree. F. to about
190.degree. F.
[0029] The adhesive compositions may be pressure sensitive
adhesives (PSA). Such adhesives can be readily dispensed as a
liquid that cures to its final form within a desired period of time
with final physical properties (i.e. pressure sensitive adhesive)
that allow it to adhere to, for example, a polymeric sheet with
adequate bond strength to resist application stresses.
[0030] The compositions can include high molecular weight polymer
additions such as tackifiers and rheology modifiers. The reduction
or elimination of entrapped air can be obtained through polymer
cure speed, polymer rheology or the method of applying the
adhesive. For example, employing faster polymer viscosity increase
or use of the spreader to trap less air between membranes.
[0031] Further details of suitable adhesive compositions as well as
the application of such compositions are described in U.S. patent
application Ser. No. 14/069,653, filed on Nov. 1, 2013, the entire
contents of which are incorporated herein by reference.
[0032] The description of the invention is merely exemplary in
nature and variations that do not depart from the gist of the
invention are intended to be within the scope of the invention.
Such variations are not to be regarded as a departure from the
spirit and scope of the invention.
* * * * *