U.S. patent application number 13/417408 was filed with the patent office on 2012-07-05 for high density polyurethane and polyisocyanurate construction boards and composite boards.
Invention is credited to Gregory A. Brandt, John B. Letts.
Application Number | 20120167510 13/417408 |
Document ID | / |
Family ID | 36609568 |
Filed Date | 2012-07-05 |
United States Patent
Application |
20120167510 |
Kind Code |
A1 |
Brandt; Gregory A. ; et
al. |
July 5, 2012 |
HIGH DENSITY POLYURETHANE AND POLYISOCYANURATE CONSTRUCTION BOARDS
AND COMPOSITE BOARDS
Abstract
A high density construction board includes a cellular body
having a first planar surface and a second planar surface. A first
glass facer is positioned adjacent the first planar surface and a
second glass facer is positioned adjacent the second planar
surface. The cellular body of the construction board includes a
polyurethane, a polyisocyanurate, or a mix of polyurethane and
polyisocyanurate and has a density greater than about 2.5 pounds
per cubic foot and less than 6 pounds per cubic foot.
Inventors: |
Brandt; Gregory A.; (Carmel,
IN) ; Letts; John B.; (Carmel, IN) |
Family ID: |
36609568 |
Appl. No.: |
13/417408 |
Filed: |
March 12, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13108053 |
May 16, 2011 |
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13417408 |
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11343466 |
Jan 30, 2006 |
7972688 |
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13108053 |
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60649385 |
Feb 1, 2005 |
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Current U.S.
Class: |
52/309.13 ;
428/220; 428/304.4; 52/745.06 |
Current CPC
Class: |
B32B 5/245 20130101;
Y10T 428/249987 20150401; B32B 27/12 20130101; B32B 15/20 20130101;
B32B 5/18 20130101; B32B 2307/712 20130101; B32B 29/007 20130101;
B32B 2419/06 20130101; B32B 27/40 20130101; C08G 18/14 20130101;
E04D 11/02 20130101; Y10T 428/249981 20150401; C08G 2110/0041
20210101; Y10T 428/249991 20150401; E04D 13/00 20130101; Y10T
428/249953 20150401; B32B 2266/08 20130101; E04C 2/205 20130101;
B32B 15/046 20130101; B32B 2266/0278 20130101; Y10T 428/249992
20150401; Y10T 428/24992 20150115 |
Class at
Publication: |
52/309.13 ;
52/745.06; 428/304.4; 428/220 |
International
Class: |
E04D 3/34 20060101
E04D003/34; B32B 3/26 20060101 B32B003/26; B32B 3/00 20060101
B32B003/00; E04C 2/22 20060101 E04C002/22 |
Claims
1. A high density construction board comprising: a cellular body
having a first planar surface and a second planar surface, a first
facer adjacent said first planar surface and a second facer
adjacent said second planar surface, wherein said cellular body
includes a polyurethane, a polyisocyanurate, or a mix of
polyurethane and polyisocyanurate and has a density greater than
about 2.5 pounds per cubic foot and less than 6 pounds per cubic
foot, and wherein said first facer and said second facer are formed
from materials selected from the group consisting of coated glass
fiber mats, uncoated glass fiber mats, chopped glass, and
combinations thereof.
2. The construction board of claim 1, wherein said density of said
cellular body is greater than about 3 pounds per cubic foot.
3. The construction board of claim 2, wherein said density of said
cellular body is greater than about 3.5 pounds per cubic foot.
4. The construction board of claim 3, wherein said density of said
cellular body is between about 4 and about 5 pounds per cubic
foot.
5. The construction board of claim 1, wherein said cellular body
includes a thickness greater than about 0.5 inches.
6. The construction board of claim 5, wherein said thickness is
from about 0.5 to about 4.5 inches.
7. The construction board of claim 6, wherein said thickness is
from about 1.0 to about 4.0 inches.
8. The construction board of claim 1 having an iso index of at
least 175.
9. A covered roof comprising: a roof deck; and a high density
construction board comprising a cellular body having a first planar
surface and a second planar surface, a first facer adjacent said
first planar surface and a second facer adjacent said second planar
surface, wherein said cellular body includes a polyurethane, a
polyisocyanurate, or a mix of polyurethane and polyisocyanurate and
has a density greater than about 2.5 pounds per cubic foot and less
than 6 pounds per cubic foot, and wherein said first facer and said
second facer are formed from materials selected from the group
consisting of coated glass fiber mats, uncoated glass fiber mats,
chopped glass, and combinations thereof.
10. The covered roof of claim 9, wherein said density of said
cellular body is greater than about 3 pounds per cubic foot.
11. The covered roof of claim 10, wherein said density of said
cellular body is greater than about 3.5 pounds per cubic foot.
12. The covered roof of claim 11, wherein said density of said
cellular body is between about 4 and about 5 pounds per cubic
foot.
13. The covered roof of claim 9, wherein said cellular body
includes a thickness greater than about 0.5 inches.
14. The covered roof of claim 9, wherein said construction board
has an iso index of at least 175.
15. The covered roof of claim 9 further comprising a protective
membrane, wherein said construction board is between said roof deck
and said protective membrane
16. The covered roof of claim 15, wherein said protective membrane
includes a polymeric membrane.
17. The covered roof of claim 15, wherein said protective membrane
includes a bituminous or asphalt membrane.
18. The covered roof of claim 15, wherein said protective membrane
derives from the application of hot asphalt to the roof.
19. A method of covering a roof comprising: applying a high density
construction board to the roof, the high density construction board
comprising a cellular body having a first planar surface and a
second planar surface, a first facer adjacent said first planar
surface and a second facer adjacent said second planar surface,
wherein said cellular body includes a polyurethane, a
polyisocyanurate, or a mix of polyurethane and polyisocyanurate and
has a density greater than about 2.5 pounds per cubic foot and less
than 6 pounds per cubic foot, and wherein said first facer and said
second facer are formed from materials selected from the group
consisting of coated glass fiber mats, uncoated glass fiber mats,
chopped glass, and combinations thereof.
20. The method of claim 19, wherein said density of said cellular
body is greater than about 3 pounds per cubic foot.
21. The method of claim 20, wherein said density of said cellular
body is greater than about 3.5 pounds per cubic foot.
22. The method of claim 21, wherein said density of said cellular
body is between about 4 and about 5 pounds per cubic foot.
23. The method of claim 19, wherein said cellular body includes a
thickness greater than about 0.5 inches.
24. The method of claim 19, wherein said high density construction
board has an iso index of at least 175.
25. The method of claim 20, further comprising the step of applying
a protective membrane to the roof subsequent to the step of
applying a high density construction board.
26. The method of claim 25, wherein said protective membrane
includes a polymeric membrane.
27. The method of claim 25, wherein said protective membrane
includes a bituminous or asphalt membrane.
28. The method of claim 25, wherein said protective membrane
derives from the application of hot asphalt to the roof.
Description
[0001] This application is a continuation of U.S. Non-Provisional
application Ser. No. 13/108,053, filed May 16, 2011, which is a
continuation of U.S. Non-Provisional application Ser. No.
11/343,466, which gains the benefit of U.S. Provisional Application
No. 60/649,385, filed Feb. 1, 2005, both of which are incorporated
herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed toward high density
polyurethane or polyisocyanurate construction boards and composite
boards, as well as their use in flat or low-slope roofing
systems.
BACKGROUND OF THE INVENTION
[0003] Flat or low-slope roofs are often covered with multi-layered
roofing systems. These roofing systems often include a roof deck,
an insulation layer, and a protective, weather-resistant membrane.
In some situations, a coverboard is also employed. In many
situations, insulation boards are typically adhered directly to a
roof deck, which is most commonly constructed of concrete or steel.
These insulation boards are typically closed-cell foams that
include polyurethane or polyisocyanurate cellular materials with an
insulating gas trapped within the cells. The insulation boards are
then covered with the weather resistant membrane.
[0004] The foam insulation boards are typically low density
cellular structures. The low density stems from two primary
considerations. The first is cost because lower density cellular
structures employ less material. Also, and often more important,
the insulation value of the board can be improved with lower
density structures. While a density of zero would be ideal (i.e., a
vacuum), a certain degree of cellular structure--which gives rise
to the density--is required to maintain the integrity of the
insulation boards. Particularly, a foam core density of greater
than about 1.5 pounds per cubic foot (pcf) is needed to maintain
strength, and a core density of less than about 2 pcf is
conventional for cost and insulation considerations.
[0005] Coverboards typically include fiber boards, gypsum products
such as densdeck, and perlite boards. Coverboards are typically
used to add integrity to the roof. For example, especially where
improved fire performance is sought, the coverboard may first be
applied to the steel deck, the insulation board is applied on top
of the coverboard, and the membrane is then applied over the
insulation board. Alternatively, especially where the roof may
experience heavy traffic, the insulation board may be applied to
the roof deck, the coverboard applied over the insulation board,
and then the membrane is applied over the coverboard. In the latter
situation, the coverboard obviously provides protection to the
insulation board, which is prone to denting or damage due to the
fact that the insulation boards are low density cellular
materials.
[0006] Coverboards are also extensively used in re-roofing
situations. In these applications, the coverboard may be referred
to as a "re-coverboard." As with residential roofs, flat or
low-slope roofs can be re-roofed without removing or "tearing off"
the existing roofing membrane. In many instances, the re-coverboard
is first applied to the existing roofing membrane before a new
roofing membrane is applied to the roof. Also, an additional layer
of insulation board can be applied before the new membrane is
applied. Depending upon the result desired, the re-coverboard can
be applied above or below the insulation board.
[0007] In other instances, a composite board is employed in lieu of
(or possible in addition to) the coverboard and insulation board.
The composite boards include an insulation layer together with a
layer that is rather robust such as a wood fiber, gypsum, or
perlite board. One advantage of the composite board is the ease of
installation. In other words, rather than apply both an insulation
board and a coverboard, the composite board can simply be installed
in a one-step process. Other advantages have been observed based
upon the fact that the composite board is formed integrally within
a controlled environment (i.e., the factory).
[0008] The use of construction boards in new roofing systems and
re-roof situations is, therefore, technologically important thereby
necessitating further advancement in the field.
SUMMARY OF THE INVENTION
[0009] In general the present invention provides a covered
low-slope or flat roof comprising (a) a roof deck, (b) an
insulation board including a polyurethane or polyisocyanurate
cellular structure having a density that is less than 2.5 pounds
per cubic foot, (c) a coverboard including a polyurethane or
polyisocyanurate cellular structure having a density greater than
about 2.5 pounds per cubic foot, and (d) a membrane.
[0010] The present invention also includes a method of re-roofing a
low-slope or flat roof, the method comprising (a) applying a
re-coverboard to an existing covered low-slope or flat roof,
wherein the re-coverboard includes a polyurethane or
polyisocyanurate cellular structure having a density that is
greater than about 2.5 pounds per cubic, and (b) applying a
membrane to the re-coverboard subsequent to the step of applying a
re-coverboard.
[0011] The present invention further includes a composite board
comprising (I) a planar structure including (a) a first layer
comprising a polyurethane or polyisocyanurate cellular structure
having a density that is less than about 2.5 pounds per cubic foot,
and (b) a second layer comprising a polyurethane or
polyisocyanurate cellular structure having a density that is
greater than about 2.5 pounds per cubic foot.
[0012] The present invention also includes a composite board
comprising a least one low density layer comprising a polyurethane
or polyisocyanurate cellular structure having a density that is
less than about 2.5 pounds per cubic foot, and a least one high
density layer comprising a polyurethane or polyisocyanurate
cellular structure having a density that is greater than about 2.5
pounds per cubic foot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a fragmentary perspective view of a high-density
construction board of the present invention.
[0014] FIG. 1A is a fragmentary perspective view of another
high-density construction board of the present invention.
[0015] FIG. 2 is a fragmentary perspective view of a roofing system
including a high density coverboard.
[0016] FIG. 3 is a fragmentary perspective view of a roofing system
including a high density coverboard.
[0017] FIG. 4 is a fragmentary perspective view of a roofing system
including re-roof layers.
[0018] FIG. 5 is a fragmentary perspective view of a roofing system
including re-roof layers.
[0019] FIG. 6 is a fragmentary perspective view of a composite
construction board of the present invention.
[0020] FIG. 6A is a fragmentary perspective view of another
composite construction board of the present invention.
[0021] FIG. 6B is a fragmentary perspective view of still another
composite construction board of the present invention.
[0022] FIG. 6C is a fragmentary perspective view of still yet
another composite construction board of the present invention.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0023] One or more embodiments of the present invention are
directed toward a high density polyurethane or polyisocyanurate
cellular construction board. The unique high density
characteristics of these boards allow them to be advantageously
used in the construction of new flat or low-sloped roofs, as well
as in re-roofing situations. In other words, these construction
boards are useful as coverboards or re-coverboards.
[0024] A high density board according to one or more embodiments is
depicted in FIG. 1. Board 10 includes a cellular body 11 having a
planar shape with first planar surface 12 and second planar surface
14, each defined by a length 16 and a width 18. Board 10 may also
be characterized by a thickness 20. Length 16 and width 18 of board
10 may vary, and these embodiments are not necessarily limited by
the selection of a particular length or width. Nonetheless, because
these boards are advantageously employed in the construction
industry, board 10 may be sized to a 4'.times.8' sheet (e.g.,
3.75'.times.7.75'), a 4'.times.10' sheet, or a 4'.times.4' sheet.
The width 20 of the board can generally be greater than about 0.5
inches, and may be from about 0.5 to 4.5 inches or in other
embodiments from about 1.0 to 4.0 inches in thickness.
[0025] Board 10 may include an optional facer 22, which can be
positioned adjacent one of the first or second planar surfaces 12
or 14. For example, as shown in FIG. 1, facer 22 may be positioned
adjacent second planer surface 14. In one or more embodiments,
facer 22 can be integral with planar surface to which it is
adjacent as a result of the methods employed to manufacture board
10, which will be disclosed below.
[0026] Facer 22 may include a variety of materials or compositions,
many of which are known or conventional in the art. Useful facers
include those comprising aluminum foil, cellulosic fibers,
reinforced cellulosic fibers, craft paper, coated glass fiber mats,
uncoated glass fiber mats, chopped glass, and combinations thereof.
Useful facer materials are known as described in U.S. Pat. Nos.
6,774,071, 6,355,701, RE 36674, 6,044,604, and 5,891,563, which are
incorporated herein by reference. The thickness of the facer
material may vary; for example, it may be from about 0.01 to about
1.00 or in other embodiments from about 0.015 to about 0.050 inches
thick. The facer materials can also include more robust or rigid
materials such as fiber board, perlite board, or gypsum board. The
thickness of the rigid facer can vary; for example, the thickness
of the rigid facer can be from about 0.2 to about 1.5 inches, or in
other embodiments from about 0.25 to about 1.0 inches.
[0027] As shown in FIG. 1A, board 10 may also optionally include a
facer 23 positioned adjacent the planer surface opposite the planar
surface on which facer 22 is positioned. For example, facer 22 is
positioned adjacent second planer surface 14, and facer 23 is
positioned adjacent first planer surface 12. Facer 23 can include
the same or different materials or compositions, as well as the
same or different thickness as facer 22.
[0028] Also, as noted above, facers 22 and 23 are optional.
Therefore, in one or more embodiments, board 10 may be facerless.
The ability to produce facerless construction boards is known as
described in U.S. Pat. No. 6,117,375, which is incorporated herein
by reference.
[0029] Body 11 includes a polyurethane or polyisocyanurate cellular
structure, which refers to an interconnected network of solid
struts or plates that form the edges and faces of cells. These
cellular structures may, in one or more embodiments, also be
defined by a "relative density" that is less than about 0.8, in
other embodiments less than 0.5, and in other embodiments less than
0.3. As those skilled in the art will appreciate, "relative
density" refers to the density of the cellular material divided by
that of the solid from which the cell walls are made. As the
relative density increases, the cell walls thicken and the pore
space shrinks such that at some point there is a transition from a
cellular structure to one that is better defined as a solid
containing isolated pores.
[0030] Despite the cellular nature of body 11, it has a high
density. In one or more embodiments, the density of body 11 is
greater than 2.5 pounds per cubic foot, as determined according to
ASTM C303, in other embodiments the density is greater than 2.8
pounds per cubic foot, in other embodiments greater than 3.0 pounds
per cubic foot, and still in other embodiments greater than 3.5
pounds per cubic foot; on the other hand, in one or more
embodiments, the density of body 11 may be less than 20 pounds per
cubic foot, in other embodiments less than 10 pounds per cubic
foot, and still in other embodiments less than 6 pounds per cubic
foot.
[0031] The boards of one or more embodiments of this invention can
be manufactured by using known techniques for producing
polyurethane or polyisocyanurate insulation boards except the
formulation may need to be modified, and the hydraulic clamping
pressure of the laminator may need to be adjusted. Furthermore, the
amount of total blowing agent (for example, carbon dioxide from the
reaction of isocyanates with isocyanate reactive compounds such as
water plus a physical blowing agent) may need to be decreased.
Likewise, the amount of catalysts may also need to be decreased.
The higher density and potentially higher foam expansion pressure
may necessitate higher hydraulic clamping pressure to maintain
uniform board thickness and to move the product down the
laminator.
[0032] In general, processes for the manufacture of polyurethane or
polyisocyanurate insulation boards are known in the art as
described in U.S. Pat. Nos. 6,117,375, 6,044,604, 5,891,563,
5,573,092, U.S. Publication Nos. 2004/01099832003/0082365,
2003/0153656, 2003/0032351, and 2002/0013379, as well as U.S. Ser.
Nos. 10/640,895, 10/925,654, and 10/632,343, which are incorporated
herein by reference.
[0033] In general, and in a manner that is conventional in the art,
the boards of the present invention may be produced by developing
or forming a polyurethane and/or polyisocyanurate foam in the
presence of a blowing agent. The foam may be prepared by contacting
an A-side stream of reagents with a B-side stream of reagents and
depositing the mixture or developing foam onto a laminator. As is
conventional in the art, the A-side stream includes an isocyanate
and the B-side includes an isocyanate-reactive compound.
[0034] The A-side stream typically only contains the isocyanate,
but, in addition to isocyanate components, the A-side stream may
contain flame-retardants, surfactants, blowing agents and other
non-isocyanate-reactive components.
[0035] Suitable isocyanates are generally known in the art. Useful
isocyanates include aromatic polyisocyanates such as diphenyl
methane, diisocyanate in the form of its 2,4'-, 2,2'-, and
4,4'-isomers and mixtures thereof, the mixtures of diphenyl methane
diisocyanates (MDI) and oligomers thereof known in the art as
"crude" or polymeric MDI having an isocyanate functionality of
greater than 2, toluene diisocyanate in the form of its 2,4' and
2,6'-isomers and mixtures thereof, 1,5-naphthalene diisocyanate,
and 1,4' diisocyanatobenzene. Exemplary isocyanate components
include polymeric Rubinate 1850 (Huntsmen Polyurethanes), polymeric
Lupranate M70R (BASF), and polymeric Mondur 489N (Bayer).
[0036] The B-side stream, which contains isocyanate reactive
compounds, may also include flame retardants, catalysts,
emulsifiers/solubilizers, surfactants, blowing agents, fillers,
fungicides, anti-static substances, water and other ingredients
that are conventional in the art.
[0037] An exemplary isocyanate-reactive component is a polyol. The
terms polyol or polyol component include diols, polyols, and
glycols, which may contain water as generally known in the art.
Primary and secondary amines are suitable, as are polyether polyols
and polyester polyols. Useful polyester polyols include phthalic
anhydride based PS-2352 (Stepen), phthalic anhydride based polyol
PS-2412 (Stepen), teraphthalic based polyol 3522 (Kosa), and a
blended polyol TR 564 (Oxid). Useful polyether polyols include
those based on sucrose, glycerin, and toluene diamine. Examples of
glycols include diethylene glycol, dipropylene glycol, and ethylene
glycol. Suitable primary and secondary amines include, without
limitation, ethylene diamine, and diethanolamine. In one embodiment
a polyester polyol is employed. In one or more embodiments, the
present invention may be practiced in the appreciable absence of
any polyether polyol. In certain embodiments, the ingredients are
devoid of polyether polyols.
[0038] Catalysts are believed to initiate the polymerization
reaction between the isocyanate and the polyol, as well as a
trimerization reaction between free isocyanate groups when
polyisocyanurate foam is desired. While some catalysts expedite
both reactions, two or more catalysts may be employed to achieve
both reactions. Useful catalysts include salts of alkali metals and
carboxylic acids or phenols, such as, for example potassium
octoate; mononuclear or polynuclear Mannich bases of condensable
phenols, oxo-compounds, and secondary amines, which are optionally
substituted with alkyl groups, aryl groups, or aralkyl groups;
tertiary amines, such as pentamethyldiethylene triamine (PMDETA),
2,4,6-tris[(dimethylamino)methyl]phenol, triethyl amine, tributyl
amine, N-methyl morpholine, and N-ethyl morpholine; basic nitrogen
compounds, such as tetra alkyl ammonium hydroxides, alkali metal
hydroxides, alkali metal phenolates, and alkali metal acholates;
and organic metal compounds, such as tin(II)-salts of carboxylic
acids, tin(IV)-compounds, and organo lead compounds, such as lead
naphthenate and lead octoate.
[0039] Surfactants, emulsifiers, and/or solubilizers may also be
employed in the production of polyurethane and polyisocyanurate
foams in order to increase the compatibility of the blowing agents
with the isocyanate and polyol components.
[0040] Surfactants may serve two purposes. First, they may help to
emulsify/solubilize all the components so that they react
completely. Second, they may promote cell nucleation and cell
stabilization. Exemplary surfactants include silicone co-polymers
or organic polymers bonded to a silicone polymer. Although
surfactants can serve both functions, a more cost effective method
to ensure emulsification/solubilization may be to use enough
emulsifiers/solubilizers to maintain emulsification/solubilization
and a minimal amount of the surfactant to obtain good cell
nucleation and cell stabilization. Examples of surfactants include
Pelron surfactant 9920, Goldschmidt surfactant B8522, and GE 6912.
U.S. Pat. Nos. 5,686,499 and 5,837,742 are incorporated herein by
reference to show various useful surfactants.
[0041] Suitable emulsifiers/solubilizers include DABCO Kitane 20AS
(Air Products), and Tergitol NP-9 (nonylphenol+9 moles ethylene
oxide).
[0042] Flame Retardants may be used in the production of
polyurethane and polyisocyanurate foams, especially when the foams
contain flammable blowing agents such as pentane isomers. Useful
flame retardants include tri(monochloropropyl)phosphate,
tri-2-chloroethyl phosphate, phosphonic acid, methyl ester,
dimethyl ester, and diethyl ester. U.S. Pat. No. 5,182,309 is
incorporated herein by reference to show useful blowing agents.
[0043] Useful blowing agents include isopentane, n-pentane,
cyclopentane, alkanes, (cyclo)alkanes, hydrofluorocarbons,
hydrochlorofluorocarbons, fluorocarbons, fluorinated ethers,
alkenes, alkynes, carbon dioxide, and noble gases. Depending on the
required density of the board, the amount of blowing agent may need
to be decreased up to about 95% from a standard formulation. The
amount of water may also, optimally, be reduced. The less blowing
agent used, the less catalyst is generally used.
[0044] As noted above, the high density polyurethane or
polyisocyanurate boards of this invention may be employed in the
construction of new roofing structures and thereby form a unique
flat or low-slope roofing system. For example, FIGS. 2 and 3,
respectively, show unique roofing systems 30 and 31 that employ
high density board 10. Furthermore, although the high density board
10 depicted in FIGS. 2 and 3 does not include facers, facers can be
used.
[0045] As shown in FIG. 2, roofing system 30 includes a roof deck
32 having insulation board 34 disposed thereon, high density board
10 positioned on optional insulation board 34, and a
water-protective layer or membrane 36 disposed on top of high
density board 10. In an alternate embodiment, as shown in FIG. 3,
roofing system 31 includes roof deck 32 with high density board 10
disposed thereon. Insulation board 34 is positioned on high density
board 10, and water protective layer or membrane 36 is disposed on
top of optional insulation board 34.
[0046] The particular embodiment shown in FIG. 2 is advantageous on
roofs that experience high traffic and/or heavy loads. High density
board 10 can be fairly robust and durable, and therefore protects
insulation board 34 from damage. As those skilled in the art will
appreciate, the low-density nature of insulation board 34 makes it
susceptible to damage, particularly through denting, when it is
mechanically impinged such as by pedestrian or vehicle traffic, or
by objects falling and contacting the roof. Also, the embodiment
shown in FIG. 2 may advantageously reduce flame propagation in
exterior fire tests such as UL 790 or ASTM E108.
[0047] Practice of this invention is not limited by the selection
of any particular roof deck. Accordingly, the roofing systems of
this embodiment, as shown in FIGS. 2 and 3, can include a variety
of roof decks. Exemplary roof decks include concrete pads, steel
decks, wood beams, and foamed concrete decks.
[0048] Practice of this invention is likewise not limited by the
selection of any particular insulation board. As is known in the
art, several insulation materials can be employed. In one
embodiment, the insulation board comprises polyurethane or
polyisocyanurate cellular material. These insulation boards are
known in the art as disclosed in U.S. Pat. Nos. 6,117,375,
6,044,604, 5,891,563, 5,573,092, U.S. Publication Nos.
2004/01099832003/0082365, 2003/0153656, 2003/0032351, and
2002/0013379, as well as U.S. Ser. Nos. 10/640,895, 10/925,654, and
10/632,343, which are incorporated herein by reference. In general,
polyurethane is characterized by having an index of from about 100
to about 120; polyisocyanurate is generally characterized by having
an index that is in excess of 150 (in other embodiments at least
175, and in other embodiments at least 200; and insulation with an
index between 120 and 150 generally includes a mix of polyurethane
and polyisocyanurate.
[0049] In those embodiments where the insulation layer comprises
polyurethane or polyisocyanurate cellular material, these cellular
materials are defined by a foam density (ASTM C303) that is less
than 2.5 pounds per cubic foot, in other embodiments less than 2.0
pounds per cubic foot, in other embodiments less than 1.9 pounds
per cubic foot, and still in other embodiments less than 1.8 pounds
per cubic foot. In one or more embodiments, these polyurethane or
polyisocyanurate insulation layers are likewise characterized by
having a density that is greater than 1.50 pounds per cubic foot
and optionally greater than 1.55 pounds per cubic foot.
[0050] Practice of this invention is likewise not limited by the
selection of any water-protective layer or membrane. As is known in
the art, several membranes can be employed to protect the roofing
system from environmental exposure, particularly environmental
moisture in the form of rain or snow. Useful protective membranes
include polymeric membranes. Useful polymeric membranes include
both thermoplastic and thermoset materials. For example, and as is
known in the art, membrane prepared from
poly(ethylene-co-propylene-co-diene)terpolymer rubber or
poly(ethylene-co-propylene)copolymer rubber can be used. Roofing
membranes made from these materials are well known in the art as
described in U.S. Pat. Nos. 6,632,509, 6,615,892, 5,700,538,
5703,154, 5,804,661, 5,854,327, 5,093,206, and 5,468,550, which are
incorporated herein by reference. Other useful polymeric membranes
include those made from various thermoplastic polymers or polymer
composites. For example, thermoplastic olefin (i.e., TPO),
thermoplastic vulcanizate (i.e., TPV), or polyvinylchloride (PVC)
materials can be used. The use of these materials for roofing
membranes is known in the art as described in U.S. Pat. Nos.
6,502,360, 6,743,864, 6,543,199, 5,725,711, 5,516,829, 5,512,118,
and 5,486,249, which are incorporated herein by reference. In one
or more embodiments, the membranes include those defined by ASTM
D4637-03 and/or ASTM D6878-03.
[0051] Still in other embodiments, the protective membrane can
include bituminous or asphalt membranes. In one embodiment, these
asphalt membranes derive from asphalt sheeting that is applied to
the roof. These asphalt roofing membranes are known in the art as
described in U.S. Pat. Nos. 6,579,921, 6,110,846, and 6,764,733,
which are incorporated herein by reference. In other embodiments,
the protective membrane can derive from the application of hot
asphalt to the roof.
[0052] Other layers or elements of the roofing systems are not
excluded by the practice of this invention. For example, and as is
known in the art, another layer of material can be applied on top
of the protective membrane. Often these materials are applied to
protect the protective membranes from exposure to electromagnetic
radiation, particularly that radiation in the form of UV light. In
certain instances, ballast material is applied over the protective
membrane. In many instances, this ballast material simply includes
aggregate in the form of rock, stone, or gravel; U.S. Pat. No.
6,487,830, is incorporated herein in this regard.
[0053] The high density boards are also advantageously useful in
re-roof situations. In other words, and as is known in the art, an
existing roof can be re-roofed without the need to remove one or
more of the existing layers of the existing roof system. Indeed, a
secondary roofing system can be applied directly over the existing
roofing system. In these instances, it is advantageous to apply a
"re-coverboard" over the existing roof before application of
another protective membrane. In certain instances, a second layer
of insulation (i.e., a recover insulation layer) may also be
applied. The additional layer of insulation can be applied above or
below the re-coverboard, and therefore the protective membrane is
either applied to the re-coverboard or the recover insulation
layer. The high-density boards of this invention are advantageously
applied in re-roofing situations as a recovery board.
[0054] For example, one embodiment is shown in FIG. 4, which
includes an original roofing system 50 and a re-roof system 51. In
a manner consistent with that described above, existing roof 50
includes roof deck 52, insulation layer 54, protective membrane 56,
and ballast material 58. Disposed on existing roof 50 is re-roof
system 51, which includes high density re-coverboard 60, recover
protective membrane 64, and ballast material 68. As noted above,
high density re-coverboard 60 is consistent with the high density
boards described hereinabove with respect to the new roof
construction. The nature of this high density board advantageously
allows it to be used as a re-coverboard. That is, re-coverboard 60
can be applied directly to an existing roof. The robust nature of
re-coverboard 60 advantageously allows it to be applied directly to
material such as ballast material 58.
[0055] In other embodiments, the re-coverboard 60 of this
embodiment can be applied directly to an existing roofing membrane.
For example, and as shown in FIG. 5, re-coverboard 60 and
protective membrane 64 can form a re-roof system 51 on top of an
existing roofing system 53, which includes existing roof deck 52,
existing insulation layer 54, and existing protective membrane
56.
[0056] In another embodiment, a composite construction board is
provided. In one embodiment, this composite board can
advantageously be employed in the manufacture of new construction
roofing systems. In other embodiments, the composite boards can
advantageously be employed in re-roof situations. In general, the
composite boards include one or more high density layers and one or
more low density layers. They may also optionally include one or
more facers or one or more reinforcing layers such as reinforcing
scrims. The positioning of the various layers and facers can
advantageously be varied based upon the intended use or properties
that are desired.
[0057] One embodiment of the composite construction board is shown
in FIG. 6. A composite board 80 includes high density layer 82, low
density layer 84 positioned underneath high density layer 82, and
an optional facer 86. The positions of high density layer 82 and
low density layer 84 may optionally be reversed. That is, rather
than the configuration of composite board 80 shown in FIG. 6, low
density layer 84, as shown in FIG. 6A, can instead be positioned
above high density layer 82.
[0058] Furthermore, additional facers may optionally be positioned
between high density layer 82 and low density layer 84 and/or
optionally be positioned on the side of composite board 80 opposite
optional facer 86. For example, as shown in FIG. 6B, composite
board 80 includes an optional facer 87 positioned between high
density layer 82 and low density layer 84, and another optional
facer 88 positioned on the side of composite board 80 opposite
optional facer 86. Furthermore, composite board 80 can also be
configured to include an optional reinforcing layer positioned
between two or more of the various layers. For example, as shown in
FIG. 6C, a fiberglass mat 89 is positioned between two optional
facers 87, 87' which are positioned between high density layer 82
and low density layer 84.
[0059] Additionally, composite board 80 can be constructed of a
plurality of alternating high density layers and low density
layers. For example, composite board 80 may include four layers,
where each layer alternates between high density and low density
layers. Furthermore, composite board 80 could be constructed of
three alternating layers where a high density layer is sandwiched
between two low density layers, or where a low density layer is
sandwiched between two high density layers. Either way, like the
other embodiments discussed above, composite board 80 includes at
least one high density layer 82 and at least one low density layer
84. Moreover, these layers can interface with one another, or
facers can be provided therebetween.
[0060] As with the high density construction boards of the first
embodiment, high density layer 82 of composite board 80 may be
characterized by having a density that is greater than 2.5 pounds
per cubic foot, in other embodiments greater than 3.0 pounds per
cubic foot, and still in other embodiments greater than 3.5 pounds
per cubic foot; on the other hand, the density of high density
layer 82 may be less than 20 pounds per cubic foot, in other
embodiments less than 10 pounds per cubic foot, and still in other
embodiments less than 6 pounds per cubic foot. Low density layer 84
can be characterized by having a foam density that is less than 2.5
pounds per cubic foot, in other embodiments less than 2.0 pounds
per cubic foot, in other embodiments less than 1.9 pounds per cubic
foot, and still in other embodiments less than 1.8 pounds per cubic
foot. In one or more embodiments, these polyurethane or
polyisocyanurate insulation layers may likewise be characterized by
having a density that is greater than 1.50 pounds per cubic foot
and optionally greater than 1.55 pounds per cubic foot.
[0061] In one or more embodiments, high density layer 82 and low
density layer 84 are cellular in nature. In other words, these
layers are characterized by an interconnected network of solid
struts or plates that form the edges and faces of cells. In one or
more embodiments, the cellular material comprises polyisocyanurate
or polyurethane.
[0062] When present, the optional facers (e.g., 86, 87, 88) can be
formed from a variety of materials. Exemplary facer materials
include aluminum foil, cellulosic fibers, reinforced cellulosic
fibers, craft paper, coated glass fiber mats, uncoated glass fiber
mats, chopped glass, and combinations thereof. Useful facer
materials are known as described in U.S. Pat. Nos. 6,774,071,
6,355,701, RE 36674, 6,044,604, and 5,891,563, which are
incorporated herein by reference. The thickness of the facer
material may vary; for example, it may be from about 0.010 to about
0.100 or in other embodiments from about 0.015 to about 0.050
inches thick. The facer materials can also include more robust or
rigid materials such as fiber board, perlite board, or gypsum
board. The thickness of the rigid facer can vary; for example, the
thickness of the rigid facer can be from about 0.20 to about 1.50
inches, or in other embodiments from about 0.25 to about 1.00
inches. When present, the optional reinforcing layers can include a
variety of materials. In one or more embodiments, fiber scrims or
mats can be employed. These mats and scrims may include woven and
non-woven constructions. The fibers may include fiberglass or
synthetic materials such as polyethylene or nylon.
[0063] In one or more embodiments, high density layer 82 and low
density layer 84 comprise the same or similar material. As a
result, there is little interfacial tension between the layers,
which provides an advantageous strength. In one or more
embodiments, high density layer 82 and low density layer 84 are
integral with one another as a result of the manufacture and
process. In other words, the composite board 80 can be manufactured
by forming low-density layer 84 on top of high density layer 82,
and the optional facer 86 can thereafter be selectively applied to
low density layer 84 (FIG. 6) and/or high density layer 82 (FIG.
6A).
[0064] In one or more embodiments, high density layer 82 and low
density layer 84 can be prepared by employing techniques known in
the art for the production of cellular polyurethane or
polyisocyanurate construction boards. As noted above, the methods
are known in the art as disclosed in U.S. Pat. Nos. 6,117,375,
6,044,604, 5,891,563, 5,573,092, U.S. Publication Nos.
2004/01099832003/0082365, 2003/0153656, 2003/0032351, and
2002/0013379, as well as U.S. Ser. Nos. 10/640,895, 10/925,654, and
10/632,343 which are incorporated herein by reference.
[0065] In one embodiment, the high density cellular body is first
formed using techniques described above. In one particular
embodiment, a facer is positioned above and below the high density
layer. Following the manufacture of this high density board, a low
density layer is formed thereon (i.e., the low density layer is
formed on one of the facers positioned on the high density layer)
using techniques known in the art. In one particular embodiment, a
facer can then be positioned on top of the low density layer (i.e.,
on the planar surface of the low density layer that is opposite to
the high density layer). In one or more embodiments, this
manufacturing technique can occur within a continuous operation or
production line.
[0066] In other embodiments, a high density cellular body or layer
can be formed with optional facers. In a second manufacturing step,
a low density layer or cellular body can be formed with optional
facers. The high density layer (with optional facers) and low
density layer (with optional facers) can be adhered together to
form the composite structure. Optionally, a reinforcement can be
positioned therebetween. Conventional adhesives may be employed to
adhere the boards to one another. In one or more embodiments, the
adhesive may include a one-part or two-part polyurethane or
polyisocyanurate adhesive. In other embodiments, a hot-melt
adhesive may be employed. Exemplary hot-melt adhesives include
polyolefin and polydiolefin-based hot-melt adhesives.
[0067] The composite boards can be sized to a variety of
dimensions. In general, composite boards 80 are planar in nature
and, as shown in FIG. 6, can be characterized by including a length
90, a width 91, and a height or thickness 92. Because the composite
boards are advantageously employed in the construction industry,
they may advantageously be sized to a four foot width and eight
foot length (i.e., 4'.times.8'), other useful sizes may include
4'.times.10 and 4'.times.4'. As for the overall thickness of the
composite board, the respective thicknesses of the high-density
layers and low-density layers can vary and therefore the overall
thickness can vary. Likewise, the thickness of the facer employed,
if any, will likewise contribute to the overall thickness of the
composite board. In any event, the thickness of the composite
boards of one or more embodiments can advantageously be from about
1.0 to about 6.0 inches, or in other embodiments from about 1.5 to
about 5.0 inches, or in other embodiments from about 2.0 to about
4.5 inches. In certain embodiments, the thickness of the
high-density layer can vary from about 0.5 to about 2.0 inches, in
other embodiments from about 0.5 to 1.0 inches, and still in other
embodiments from about 0.50 to about 0.75 inches. The low-density
layer, in one or more embodiments, can also vary from about 0.5 to
about 4.0 inches, and in other embodiments from about 1.0 to about
4.0 inches, and still in other embodiments from about 2.0 to about
4.0 inches.
[0068] In order to demonstrate the practice of the present
invention, the following examples have been prepared and tested.
The examples should not, however, be viewed as limiting the scope
of the invention. The claims will serve to define the
invention.
EXAMPLES
Experiment 1
[0069] A 4'.times.8'.times.0.75'' high-density cellular body was
manufactured with cellulosic facers on the upper and lower surfaces
to form a high-density construction board in accordance with this
invention. The cellular body was characterized by a foam density of
7.5 pounds per cubic foot. The compressive strength of the board
(per ASTM 1620) was 42.1 pounds per square inch.
Experiment 2
[0070] A 4'.times.8'.times.0.75'' high density cellular body was
manufactured with cellulosic facers on the upper and lower surfaces
to form a high density construction board in accordance with this
invention. The cellular body was characterized by a foam density of
12 pounds per cubic foot. This board was tested according to UL 790
for fire spread. Specifically, the board was mechanically attached
to a 60 mil low slope, flame retardant EPDM membrane and positioned
on top of a 3'' standard low-density board. Pursuant to this test,
the fire spread was a maximum of 3'11'' with a lateral spread no
closer than 6 inches from the edges at a 0.5:12 slope. As those
skilled in the art will appreciate, a pass requires less than 6'
flame spread, and the front and lateral flame spread is permitted
only along one edge.
Experiment 3
[0071] Using a similar board to that employed in Experiment 2, the
UL 790 test was performed with a 45 mil standard EPDM membrane in
lieu of the 60 mil membrane. The flame spread was 4' 6'' of frontal
flame spread with no lateral flame spread closer than 4'' from the
edges.
Experiment 4
[0072] A high density board similar to that in Experiment 2 was
analyzed for uplift performance. The board was mechanically
attached to a 45 mil standard EPDM membrane using 16 fasteners and
plates per 4'.times.8' board. Failure occurred at 41 seconds into
165 pounds per square foot. When the fastener pattern was reduced
to 10 fasteners end plates per 4'.times.8' board, failure occurred
at 34 seconds into 105 pounds per square foot.
[0073] Various modifications and alterations that do not depart
from the scope and spirit of this invention will become apparent to
those skilled in the art. This invention is not to be duly limited
to the illustrative embodiments set forth herein.
* * * * *