U.S. patent application number 16/989242 was filed with the patent office on 2020-11-26 for fire performance for wood veneer laminated ceiling tile.
The applicant listed for this patent is ARMSTRONG WORLD INDUSTRIES, INC.. Invention is credited to Marsha S. BISCHEL, Kenneth P. KEHRER, Lida LU, Michelle X. WANG.
Application Number | 20200370302 16/989242 |
Document ID | / |
Family ID | 1000005005121 |
Filed Date | 2020-11-26 |
United States Patent
Application |
20200370302 |
Kind Code |
A1 |
BISCHEL; Marsha S. ; et
al. |
November 26, 2020 |
FIRE PERFORMANCE FOR WOOD VENEER LAMINATED CEILING TILE
Abstract
The present invention is directed to a building panel having a
laminate structure comprising a cellulosic layer; and a topcoat
layer that is substantially impervious to ambient moisture. The
topcoat layer comprises a sealant sub-layer, an intumescent
sub-layer comprising an intumescent composition, and the sealant
sub-layer is positioned between the cellulosic layer and the
intumescent sub-layer such that the intumescent sub-layer is
separated from the first major surface of the cellulosic layer by
the sealant sub-layer. The resulting building panel exhibits
superior flame retardancy resulting in a Class A fire rating,
according to ASTM E-84.
Inventors: |
BISCHEL; Marsha S.;
(Lancaster, PA) ; KEHRER; Kenneth P.; (Lancaster,
PA) ; LU; Lida; (Coraopolis, PA) ; WANG;
Michelle X.; (Lititz, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ARMSTRONG WORLD INDUSTRIES, INC. |
Lancaster |
PA |
US |
|
|
Family ID: |
1000005005121 |
Appl. No.: |
16/989242 |
Filed: |
August 10, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15334923 |
Oct 26, 2016 |
10745920 |
|
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16989242 |
|
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62247569 |
Oct 28, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 2311/24 20130101;
B32B 15/18 20130101; B32B 2307/304 20130101; B32B 37/1207 20130101;
B32B 9/042 20130101; B32B 9/005 20130101; B32B 2307/73 20130101;
E04B 9/34 20130101; B32B 2037/1215 20130101; B32B 15/20 20130101;
B32B 2255/26 20130101; B32B 2307/50 20130101; B32B 21/04 20130101;
E04B 9/045 20130101; B32B 2307/3065 20130101; E04F 13/12 20130101;
B32B 7/12 20130101; E04F 13/0866 20130101; B32B 2250/02 20130101;
B32B 2307/412 20130101; E04B 9/225 20130101; B32B 21/14 20130101;
B32B 2607/00 20130101; B32B 15/10 20130101; B32B 21/02 20130101;
B32B 2255/28 20130101; B32B 2419/00 20130101; B32B 2307/732
20130101; E04F 13/077 20130101; B32B 2255/08 20130101 |
International
Class: |
E04F 13/077 20060101
E04F013/077; E04B 9/22 20060101 E04B009/22; E04B 9/34 20060101
E04B009/34; B32B 21/14 20060101 B32B021/14; B32B 9/04 20060101
B32B009/04; B32B 9/00 20060101 B32B009/00; B32B 21/04 20060101
B32B021/04; B32B 21/02 20060101 B32B021/02; B32B 15/18 20060101
B32B015/18; B32B 7/12 20060101 B32B007/12; B32B 15/10 20060101
B32B015/10; B32B 15/20 20060101 B32B015/20; E04B 9/04 20060101
E04B009/04; E04F 13/12 20060101 E04F013/12 |
Claims
1. A ceiling panel comprising a laminate structure, the laminate
structure comprising: a cellulosic veneer layer comprising a first
major surface opposite a second major surface; a topcoat layer
comprising: a first sub-layer atop the cellulosic veneer layer, the
first sub-layer comprising a sealant composition comprising a first
polymer; and a second sub-layer atop the first sub-layer, the
second sub-layer comprising the intumescent composition. an
adhesive layer formed from an adhesive composition comprising a
thermoplastic polymer; and a metallic substrate layer, the
cellulosic veneer layer at least partially bonded to the metallic
substrate by the adhesive layer.
2. The ceiling panel according to claim 1, wherein the topcoat
layer is substantially clear.
3. The ceiling panel according to claim 1, wherein the first
sub-layer directly contacts the first major surface of the
cellulosic veneer layer and the adhesive layer directly contacts
the second major surface of the cellulosic veneer layer.
4. The ceiling panel according to claim 1, wherein the first major
surface of the cellulosic veneer layer comprises pores, and wherein
the first sub-layer directly contacts the first major surface of
the cellulosic veneer layer thereby sealing at least a portion of
the pores.
5. The ceiling panel according to claim 1, wherein the adhesive
layer directly contacts the second major surface of the veneer
layer and the second sub-layer is separated from the first major
surface of the veneer layer by a height of the first sub-layer.
6. The ceiling panel according to claim 1, wherein the intumescent
composition comprises: a carbon donor compound; and an acid donor
compound comprising ammonium phosphate, di-ammonium phosphate,
ammonium dihydrogen phosphate, ammonium polyphosphate, melamine
phosphate, guanylurea phosphate, urea phosphate, p-toluenesulphonic
acid, ammonium sulfate, ammonium borate, and combinations
thereof.
7. The ceiling panel according to claim 1, wherein the first
polymer comprises one or more of vinyl or acrylic homopolymers or
copolymers formed from ethylenically unsaturated monomers such as
ethylene or butadiene and vinyl monomers such as styrene, vinyl
esters such as vinyl acetate, vinyl propionate, vinyl butyrates,
acrylic acid, methacrylic acid, or esters of acrylic acid and/or
esters of methacrylic acid.
8. The ceiling panel according to claim 1, wherein the topcoat
layer further comprises a third sub-layer that is atop the second
sub-layer, the third sub-layer being substantially impervious to
ambient moisture.
9. The ceiling panel according to claim 8, wherein the second
sub-layer further comprises a second polymer having a second glass
transition temperature and the third sub-layer further comprises a
third polymer having a third glass transition temperature, the
third glass transition temperature being equal to or less than the
second glass transition temperature.
10. The ceiling panel according to claim 1, wherein the second
sub-layer comprises a second polymer that is a carbon donor
compound of the intumescent composition.
11. The ceiling panel according to claim 1, wherein the adhesive
composition is a hot-melt composition.
12. The ceiling panel according to claim 1, wherein the metallic
substrate has a thickness ranging from about 35 mils to about 65
mils and the cellulosic veneer layer has a thickness ranging from
about 25 mils to about 45 mils.
13. A ceiling panel comprising a laminate structure, the laminate
structure comprising: a topcoat layer comprising: a sealant
composition; and an intumescent composition; a cellulosic veneer
layer having a first major surface opposite a second major surface;
an adhesive layer formed from an adhesive composition comprising a
thermoplastic polymer; and a metallic substrate layer.
14. The ceiling panel according to claim 13, wherein the topcoat
includes a first sub-layer comprising the sealant composition and a
second sub-layer comprising the intumescent composition.
15. The ceiling panel according to claim 14, wherein the first
major surface of the cellulosic veneer layer comprises pores that
are at least partially sealed by the first sub-layer of the topcoat
layer.
16. The ceiling panel according to claim 14, wherein the second
sub-layer is separated from the first major surface of the veneer
layer by a height of the first sub-layer.
17. A building panel comprising a laminate structure, the laminate
structure comprising: a cellulosic layer; and a topcoat layer that
is substantially impervious to ambient moisture, the topcoat layer
comprising: a sealant sub-layer; and an intumescent sub-layer
comprising an intumescent composition; the sealant sub-layer
positioned between the cellulosic layer and the intumescent
sub-layer such that the intumescent sub-layer is separated from the
first major surface of the cellulosic layer by the sealant
sub-layer.
18. The building panel according to claim 17, wherein the second
sub-layer comprises a second polymer that is a carbon donor
compound of the intumescent composition.
19. The building panel according to claim 18, wherein the topcoat
layer further comprises a third sub-layer that is atop the second
sub-layer, the third sub-layer being substantially impervious to
ambient moisture.
20. The building panel according to claim 19, wherein the second
polymer has a second glass transition temperature and the third
sub-layer further comprises a third polymer having a third glass
transition temperature, the third glass transition temperature
being equal to or less than the second glass transition
temperature.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of United States
Nonprovisional Patent application Ser. No. 15/334,923, filed Oct.
26, 2016, which in turn claims the benefit of U.S. Provisional
Application Ser. No. 62/247,569, filed on Oct. 28, 2015, the
entireties of which are incorporated herein by reference.
BACKGROUND
[0002] Building products for interior room environments balance
interests with respect to cosmetic value, material cost, structural
integrity, and fire safety. Previously, maximizing one or two of
the aforementioned interests required sacrificing the remaining
interests. For example, a building panel that uses natural
materials (e.g., natural grain from real wood, as compared to
replica grain from printed wood texture) may have superior cosmetic
value. However, such building panels also previously had associated
safety concerns as either the entire building panel would be made
from wood, thereby increasing flammability concerns, or a cosmetic
laminate structure could be used, in which case the veneer layer is
susceptible to delamination at high heat, causing the veneer layer
to fall from the building panel, thereby endangering individuals
below the building and/or further fueling a fire.
[0003] Regarding laminate structures, previous attempts have been
made to improve the fire safety performance of these building
panels. Improved fire safety performance can be qualified as
either: Class A, B, or C rating--with Class A being the best and C
being the worst. However, some previous attempts to achieve
superior fire safety have involved supporting the building panels
during fire testing by use of a variety of external means--such as
rods, bars and/or chicken wire. Adding such external support is not
only inconsistent with the requirements of the building code or the
current ASTM E84 standard, but it also provides a false indication
of the integrity of the building panel during fire testing. Stated
simply, there is a need for building panels that exhibit superior
cosmetic value while also exhibiting high lamination integrity,
especially during a fire in order to ensure proper fire safety.
BRIEF SUMMARY
[0004] According to embodiments, the present invention is directed
to a ceiling panel comprising a laminate structure, the laminate
structure comprising a topcoat layer comprising an intumescent
composition; a cellulosic veneer layer comprising a first major
surface opposite a second major surface; an adhesive layer formed
from an adhesive composition comprising a thermoplastic polymer;
and a metallic substrate layer; wherein the cellulosic veneer layer
is at least partially bonded to the metallic substrate by the
adhesive layer.
[0005] In other embodiments, the present invention is directed to a
ceiling panel comprising a laminate structure, the laminate
structure comprising a topcoat layer comprising a sealant
composition; and an intumescent composition; a cellulosic veneer
layer having a first major surface opposite a second major surface;
an adhesive layer formed from an adhesive composition comprising a
thermoplastic polymer; and a metallic substrate layer; wherein the
first sub-layer is atop the first major surface of the cellulosic
veneer layer; and the second sub-layer is atop the first
sub-layer.
[0006] In a further embodiment, the invention can be a ceiling
panel comprising a laminate structure, the laminate structure
comprising: a cellulosic veneer layer comprising a first major
surface opposite a second major surface; a topcoat layer
comprising: a first sub-layer atop the cellulosic veneer layer, the
first sub-layer comprising a sealant composition comprising a first
polymer; and a second sub-layer atop the first sub-layer, the
second sub-layer comprising the intumescent composition. an
adhesive layer formed from an adhesive composition comprising a
thermoplastic polymer; and a metallic substrate layer, the
cellulosic veneer layer at least partially bonded to the metallic
substrate by the adhesive layer.
[0007] In an even further embodiment, the invention can be a
ceiling panel comprising a laminate structure, the laminate
structure comprising: a topcoat layer comprising: a sealant
composition; and an intumescent composition; a cellulosic veneer
layer having a first major surface opposite a second major surface;
an adhesive layer formed from an adhesive composition comprising a
thermoplastic polymer; and a metallic substrate layer.
[0008] In yet another embodiment, the invention can be a building
panel comprising a laminate structure, the laminate structure
comprising: a cellulosic layer; and a topcoat layer that is
substantially impervious to ambient moisture, the topcoat layer
comprising: a sealant sub-layer; and an intumescent sub-layer
comprising an intumescent composition; the sealant sub-layer
positioned between the cellulosic layer and the intumescent
sub-layer such that the intumescent sub-layer is separated from the
first major surface of the cellulosic layer by the sealant
sub-layer.
[0009] In other embodiments, the present invention is directed to a
building panel comprising a laminate structure, the laminate
structure comprising a cellulosic layer; and a topcoat layer that
is substantially impervious to ambient moisture and comprising an
intumescent composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0011] FIG. 1 is top perspective view of the building panel
according to the present invention;
[0012] FIG. 2 is a cross-sectional view of the building panel
according to the present invention, the cross-sectional view being
along the II line set forth in FIG. 1;
[0013] FIG. 3 is cross-sectional view of a building panel according
to other embodiments of the present invention, the cross-sectional
view being along the II line set forth in FIG. 1;
[0014] FIG. 4 is cross-sectional view of a building panel according
to other embodiments of the present invention, the cross-sectional
view being along the II line set forth in FIG. 1;
[0015] FIG. 5 is a ceiling system comprising the building panel of
the present invention.
DETAILED DESCRIPTION
[0016] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0017] As used throughout, ranges are used as shorthand for
describing each and every value that is within the range. Any value
within the range can be selected as the terminus of the range.
[0018] Unless otherwise specified, all percentages and amounts
expressed herein and elsewhere in the specification should be
understood to refer to percentages by weight. The amounts given are
based on the active weight of the material. According to the
present application, the term "about" means+/-5% of the reference
value. According to the present application, the term
"substantially free" means less than about 0.1 wt. % based on the
total of the referenced value.
[0019] Referring to FIGS. 1 and 5, the present invention includes a
ceiling system 1 as well as a building panel 10 that may be used in
the ceiling system 1. The ceiling system 1 may comprise at least
one or more of the building panels 10 installed in an interior
space, whereby the interior space comprises a plenum space 3 and an
active room environment 2. The plenum space 3 is defined by the
space occupied between a structural barrier 4 between floors of a
building and the lower major surface 12 of the building panel 10.
The plenum space 3 provides space for mechanical lines within a
building (e.g., HVAC, electrical lines, plumbing,
telecommunications, etc.). The active space 2 is defined by the
space occupied beneath the upper major surface 11 of the building
panel 10 for one floor in the building. The active space 2 provides
room for the building occupants during normal intended use of the
building (e.g., in an office building, the active space would be
occupied by offices containing computers, lamps, etc.).
[0020] Each of the building panels 10 may be supported in the
interior space by one or more supports 5. Each of the building
panels 10 are installed such that the upper major surface 11 of the
building panel 10 faces the active room environment 2 and the lower
major surface 12 of the building panel 10 faces the plenum space 3.
The building panels 10 of the present invention have superior fire
safety performance--particularly when a fire originates in the
active room environment 2--without sacrificing the desired
aesthetic appearance of the building panel 10, as discussed
herein.
[0021] Referring to FIG. 1, the present invention is a building
panel 10 comprising a laminate structure having multiple layers.
The building panel 10 may comprise an upper major surface 11, a
lower major surface 12 that is opposite the upper major surface 11,
and major side surfaces 13 that extend from the upper major surface
11 to the lower major surface 12 to form a perimeter of the
building panel 10. The major side surfaces 13 may comprise first
and second longitudinal side surfaces 41, 42 extending
substantially parallel to each other. The major side surfaces 13
may further comprise first and second transverse side surfaces 31,
32 extending substantially parallel to each other. The first and
second longitudinal side surfaces 41, 42 may extend substantially
orthogonal to the first and second transverse side surfaces 31,
32.
[0022] The building panel 10 may have a panel thickness "t.sub.P"
as measured from the upper major surface 11 to the lower major
surface 12. The panel thickness t.sub.P may range from about 25
mils to about 250 mils--including all values and sub-ranges
there-between. The building panel 10 may have a panel length
"L.sub.P" as measured from the first transverse side surface 31 to
the second transverse side surface 32--i.e., the distance along one
of the first or second longitudinal side surfaces 41, 42. The panel
length L.sub.P may range from about 10 inches to about 120
inches--including all values and sub-ranges there-between. The
building panel 10 may have a panel width "W.sub.P" as measured from
the first longitudinal side surface 41 to the second longitudinal
side surface 42--i.e., the distance along one of the first or
second transverse side surfaces 31, 32. The panel width W.sub.P may
range from about 12 inches to about 60 inches--including all values
and sub-ranges there-between. The building panel 10 comprises a
decorative pattern 30 that is visible from the upper major surface
11. The decorative pattern 30 may comprise a pattern formed from
natural materials, such as cellulosic materials (e.g., wood grain,
knots, burl, etc.).
[0023] The laminate structure of the building panel 10 may comprise
a substrate layer 200, an adhesive layer 300, a cellulosic layer
400, and a topcoat layer 500. Specifically, the topcoat layer 500
is atop the cellulosic layer 400, the cellulosic layer 400 is atop
the adhesive layer 300, and the adhesive layer is atop the
substrate 200 layer--as discussed further herein. The cellulosic
layer 400 may be adhesively bonded to the substrate layer 200 by
the adhesive layer 300, as discussed further herein. The
combination of layers 200, 300, 400, 500 of the present invention
creates a laminate structure having high lamination integrity in a
ceiling system under both standard conditions (i.e. daily operation
of an interior building environment) but also during exposure to
the extreme heat and temperature that may result from a fire. Thus,
the laminate structure of the present invention results in a robust
building panel 10 that meets at least Class B fire rating,
preferably Class A fire rating. For the purposes of the present
invention, "high lamination integrity" means each layer 200, 300,
400, 500 of the laminate structure remains coupled and/or bonded to
the adjacent layer 200, 300, 400, 500 without the aid of external
supports (e.g., rods, bars, chicken wire, and the like) applied to
one or more of the major surfaces of the laminate structure. Stated
otherwise, the internal bond of each layer and/or coupling between
each layer 200, 300, 400, 500 is sufficient such that each layer
200, 300, 400, 500 does not internally degrade or delaminate from
an adjacent layer 200, 300, 400, 500 to an extent that causes the
laminate structure to break apart.
[0024] Referring now to FIG. 2, the substrate layer 200 may
comprises an upper substrate surface 211 and a lower substrate
surface 212 that is opposite the upper substrate surface 211. The
substrate layer 200 may comprise a substrate side surface 213 that
extends from the upper substrate surface 211 to the lower substrate
surface 212 and forms a perimeter of the substrate layer 200. The
substrate side surface 213 may form a portion of the major side
surface 13 of the building panel 10. Stated otherwise, the major
side surface 13 of the building panel 10 may comprise the substrate
side surface 213.
[0025] The substrate layer 200 may be formed from a metallic
material, ceramic material, or composite material. Non-limiting
examples of metallic material include aluminum, steel, and iron. In
a preferred embodiment, the substrate layer 200 is formed from
aluminum. The substrate layer 200 may have a substrate thickness
"t.sub.S" ranging from about 20 mils to about 100 mils--including
all values and sub-ranges there-between. The substrate thickness
t.sub.S may range from about 25 mils to about 80 mils. In a
preferred embodiment, the substrate thickness t.sub.S ranges from
about 30 mils to about 65 mils--including all values and sub-ranges
there-between.
[0026] The adhesive layer 300 may comprises an upper adhesive
surface 311 and a lower adhesive surface 312 opposite the upper
adhesive surface 311. The adhesive layer 300 may comprise an
adhesive side surface 313 that extends from the upper adhesive
surface 311 to the lower adhesive surface 312 and forms a perimeter
of the adhesive layer 300. The adhesive side surface 313 may form a
portion of the major side surface 13 of the building panel 10.
Stated otherwise, the major side surface 13 of the building panel
10 may comprise the adhesive side surface 213. The adhesive layer
300 may have an adhesive thickness "t.sub.A" ranging from about 2
mils to about 20 mils--including all values and sub-ranges
there-between--as measured from the upper adhesive surface 311 to
the lower adhesive surface 312. In a preferred embodiment, the
adhesive thickness "t.sub.A" ranges from about 5 mils to about 15
mils--including all values and sub-ranges there-between.
[0027] The adhesive layer 300 may be formed from an adhesive
composition that is a hot-melt composition. According to the
purposes of the present invention, the term "hot-melt adhesive
composition" means a composition having a melt viscosity ranging
from about 10,000 centipoise to about 40,000 centipoise at a
temperature of about 135.degree. C.--including all values and
sub-ranges there-between. The hot-melt adhesive composition may be
solid at room temperature and be substantially free of solvent. The
adhesive composition may comprise adhesive polymer in an amount
ranging from about 50 wt. % to about 100 wt. % based on the total
weight of the adhesive composition--including all values and
sub-ranges there-between.
[0028] The adhesive polymer according to the present invention may
be a thermoplastic polymer. Non-limiting examples of the
thermoplastic polymer may include moisture cured polyester modified
polyurethane polymers. Such polyester modified polyurethanes may be
formed by reacting organic diisocyanate with difunctional polyester
polyol and low molecular weight diols (as chain-extending agents)
at a non-limiting NCO:OH ratio of about 0.7:1 to about
1.3:1--including all sub-ranges and ratios there-between.
[0029] Non-limiting examples of polyester polyol include
di-functional polyester diols containing alcoholic hydroxyl groups.
Suitable polyester diols are polyester having average molecular
weights of from 800 to 5000 and preferably from 2000 to 4000
produced from (i) dicarboxylic acids containing at least 6 carbon
atoms, such as adipic acid, pimelic acid, suberic acid, azelaic
acid and/or sebacic acid (preferably adipic acid, as the sole acid
component) and (ii) alkane diols that may contain at least 4 carbon
atoms, such as, for example, 1,4-dihydroxy-butane,
1,5-dihydroxypentane and/or 1,6-dihydroxy-hexane. Polycondensates
of w-hydroxyalkane-mono-carboxylic acids and the polymers of their
lactones are also suitable, although less preferred.
[0030] Low molecular weight diols suitable as chain-extending
agents in accordance with the present invention include, in
particular, aliphatic diols having average molecular weight of from
62 to 400 or mixtures thereof. Non-limiting examples of such diols
include ethylene glycol, 1,3-dihydroxy-propane,
1,4-dihydroxy-butane, 1,5-dihydroxypentane, 1,6-dihydroxyhexane,
and the like.
[0031] Non-limiting examples of suitable aromatic polyisocyanates
include all isomers of toluylene-diisocyanate (TDI),
naphthalene-1,5-diisocyanate, diphenylmethane-4,4'-diisocyanate
(MDI), diphenylmethane-2,4'-diisocyanate and mixtures of
4,4'-diphenylmethane-diisocyanate with the 2,4' isomer or mixtures
thereof with oligomers of higher functionality (so-called crude
MDI), xylylene-diisocyanate (XDI),
4,4'-diphenyl-dimethylmethane-diisocyanate, di- and
tetra-alkyl-diphenylmethane-diisocyanate,
4,4'-dibenzyl-diisocyanate, 1,3-phenylene-diisocyanate and
1,4-phenylene-diisocyanate. Examples of suitable cycloaliphatic
polyisocyanates are the hydrogenation products of the
above-mentioned aromatic diisocyanates, such as
4,4'-dicyclohexylmethane-diisocyanate (H.sub.12MDI),
1-isocyanatomethyl-3-isocyanato-1,5,5-trimethyl-cyclohexane
(isophorone-diisocyanate, IPDI), cyclohexane-1,4-diisocyanate,
hydrogenated xylylene-diisocyanate (H.sub.6XDI),
1-methyl-2,4-diisocyanato-cyclohexane, m- or
p-tetramethylxylene-diisocyanate (m-TMXDI, p-TMXDI) and dimer-fatty
acid diisocyanate. Examples of aliphatic polyisocyanates are
tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate,
hexane-1,6-diisocyanate (HDI),
1,6-diisocyanato-2,2,4-trimethylhexane,
1,6-diisocyanato-2,4,4-trimethylhexane and
1,2-dodecane-diisocyanate (C.sub.12DI).
[0032] The thermoplastic adhesive compositions comprise
thermoplastic polymer that may transition from the glassy state to
the molten state (or may melt entirely) when heated to an elevated
temperature (e.g., when an office building catches on fire). Thus,
when thermoplastic polymer is exposed to elevated temperatures,
such as in a fire, the adhesive layer may become susceptible to
creep, especially when a load is applied to that adhesive layer
(e.g., a cellulosic layer adhered to the adhesive layer). With the
increased susceptibility to creep, there is a greater likelihood
that the adhesive layer will deform and fail at such elevated
temperatures. Therefore, laminate structures using adhesive that
comprises thermoplastic polymer are at risk of having certain
layers (i.e., cellulosic layers) delaminate and separate from the
over laminate structure during a fire.
[0033] However, the adhesive composition of the present invention
overcomes these difficulties by using a moisture cured
thermoplastic polymer. Specifically, the moisture-curing produces a
high crosslinking density within the polymer network, which
increases adhesive bond strength at room temperature. Furthermore,
the thermoplastic polymer may have a polyester-modified polymer
backbone--with the polyester further enhancing the high temperature
performance of the moisture-cured thermoplastic polymer. Stated
otherwise, the moisture-cured, polyester-modified polyurethane
adhesive of the present invention forms an adhesive layer 300
having high lamination integrity even at elevated temperatures,
which translates into a robust building panel 10 having superior
structural integrity during a fire. The adhesive polymer of the
present invention may exhibit a higher melting and softening
temperatures, giving higher adhesive strength to the final building
panel 10. With such high-heat properties, the adhesive composition
of the present invention increases resistance to delamination of
the cellulosic layer 400 from the substrate layer 200 in a fire
even without the help of whether external means (e.g. chicken wire,
rods, etc.) providing additional structural support to one or both
of the upper major surface 11 and the lower major surface 12 of the
building panel 1.
[0034] The adhesive layer 300 may be formed by heating the adhesive
composition to an application temperature ranging from about
120.degree. C. to about 165.degree. C. (including all values and
sub-ranges there-between) and applying the heated adhesive
composition to at least one of the substrate layer 200 or the
cellulosic layer 400, and joining the substrate layer 200 to the
cellulosic layer 400, as discussed further herein.
[0035] Once the adhesive composition is heated to the application
temperature and applied (continuously or discontinuously) to at
least one of the substrate layer 200 or the cellulosic layer 400,
the adhesive composition may develop significant green strength
once a cellulosic layer is applied within about 30 seconds; bond
strength continues to develop over time, and in the presence of
moisture. The phrase "green strength" refers to a material's
ability to resist deformation and/or fracture before the
composition has been cured/cross-linked. Developing significant
green strength within about 30 seconds after lamination allows for
faster coupling of the cellulosic layer 400 to the substrate layer
200 as pressure can be applied to at least one of the substrate
layer 200 or the cellulosic layer 400 to ensure proper bonding
between the substrate layer 200 and the cellulosic layer 400 by the
resulting adhesive layer 300.
[0036] Once the adhesive composition is heated to the application
temperature and applied to at least one of the substrate layer 200
or the cellulosic layer 400, the adhesive composition may also have
an open time up to about 45 seconds. The phrase "open time" refers
to a time span in which a composition may be workable, allowing for
proper application of that composition before final
curing/cross-linking. Having an open time up to about 45 seconds
allows sufficient time for the cellulosic layer 400 to be coupled
to the substrate layer 200 without undermining the adhesive
strength formed by the resulting adhesive layer 300.
[0037] The adhesive composition of the present invention may
further comprise additives selected from the group consisting of
2,2'-dimorpholinethyl ether catalyst,
di(2,6-dimethylmorpholinoethyl)ether catalyst, adhesion promoters,
diluents, plasticizers, fillers, antioxidants pigments, UV
absorbers and combinations thereof. In other embodiments, the
adhesive composition may further comprise a flame retardant.
Non-limiting examples of flame retardant may include ammonium
hydroxide, magnesium hydroxide, huntite, hydromagnesite, silica,
polyphosphate, melamine cyanurate, chloride salts--such as sodium
chloride, antimony oxide, and borates, such as calcium borate,
magnesium borate, zinc borate, and combinations thereof. The flame
retardant may be present in the adhesive composition in an amount
ranging from about 0 wt. % to about 50 wt. % based on the total
weight of the adhesive composition--including all values and
sub-ranged there-between.
[0038] Referring to FIG. 2, the cellulosic layer 400 may comprise
an upper cellulosic surface 411 and a lower cellulosic surface 412
opposite the upper cellulosic surface 411. The cellulosic layer 400
may comprise a cellulosic side surface 413 that extends from the
upper cellulosic surface 411 to the lower cellulosic surface 412
and forms a perimeter of the cellulosic layer 400. The cellulosic
side surface 413 may form a portion of the major side surface 13 of
the building panel 10. Stated otherwise, the major side surface 13
of the building panel 10 may comprise the cellulosic side surface
413.
[0039] In the exemplified embodiments, the cellulosic layer 400 is
a cellulosic veneer layer 400 having a cellulosic veneer thickness
"t.sub.v" ranging from about 5 mils to about 100 mils--including
all values and sub-ranges there-between. The cellulosic veneer
thickness t.sub.v may range from about 10 mils to about 80
mils--including all values and sub-ranges there-between;
alternatively from about 20 mils to about 50 mils--including all
values and sub-ranges there-between. According to some embodiments,
the cellulosic veneer thickness t.sub.v may range from about 25
mils to about 35 mils.
[0040] According to the present invention the term "veneer" means a
thin layer formed entirely out of the cellulosic material or that
is comprised of thin layers of cellulosic material that have been
adhered together, and then cut into continuous sheets. Veneer
layers may be adhered together using a thermoset resin. A
non-limiting example of thermoset resin may comprise melamine
formaldehyde. The cellulosic material used to form the veneer layer
may be stained or dyed.
[0041] The cellulosic veneer layer 400 may be formed from a
cellulosic material such as wood, bamboo, and a combination
thereof, and may be naturally occurring or engineered. Non-limiting
examples of wood include cherry, maple, oak, walnut, pine, poplar,
spruce, chestnut, mahogany, rosewood, teak, ash, hickory, beech,
birch, cedar, fir, hemlock, basswood, alder wood, obeche wood, and
combinations thereof. The cellulosic veneer layer 400 may comprise
pores that are not only present within the body of the cellulosic
veneer layer 400 but also exposed on at least one of the upper
cellulosic veneer surface 411, lower cellulosic veneer surface 412,
and/or the cellulosic veneer side surface 413. The porosity of the
cellulosic veneer layer 400 will depend on the bamboo or type of
wood selected as the material that forms the cellulosic veneer
layer 400.
[0042] The benefit of using a cellulosic veneer layer 400 is that
the resulting building panel 10 will exhibit authentic decorative
features of real wood and/or bamboo (e.g., wood grain, knots, burl,
etc.) while minimizing the overall thickness required for the
building panel 100 without necessitating artificial print layers.
Artificial print layers, such as those on various papers or
plastics, have been used as a way to recreate wood grain, knots,
burl, etc., while minimizing layer thickness. Such print layers,
however, are undesirable because of the limited amount of variation
the cellulosic pattern across a large number of panels as compared
to the same large number of panels that use veneer formed from real
wood and/or bamboo. Stated otherwise, artificial print layers are
not preferred because of the repetition in the decorative pattern
over large installation areas. Regarding building panels formed
entirely from cellulosic materials--although the decorative pattern
is formed from real wood grain, knots, burl, etc., such building
panels have inferior strength to weight ratios compared to laminate
structure building panels using light weight metallic substrates
(e.g., aluminum), and such cellulosic building panels may increase
some degree of risk of flammability based on more cellulosic
material being present in the building panel. Thus, the cellulosic
veneer layer 400 helps impart authentic decorative features of a
cellulosic material while also balancing flammability, strength,
and weight concerns of the overall building panel 10. The
cellulosic veneer layer 400 also allows installation of building
panels with larger dimensions without adding too much weight to the
building system.
[0043] According to the present invention the laminate structure
may be free of a veneer backing layer (e.g., a cellulosic backing
layer such as a paper backing layer) positioned between the
cellulosic veneer layer 400 and the adhesive layer 300.
Specifically, the laminate structure of the present invention may
be free of a veneer backing layer that is applied directly to the
lower veneer surface 412 of the cellulosic veneer layer 400. Having
no veneer backing layer ensures that the adhesive layer 300
directly contacts the cellulosic veneer layer 400 and further
enhances fire safety as there is less cellulosic material to burn
in a fire. In other embodiments, however, a cellulosic (e.g.,
paper) veneer backing layer (not pictured) may be positioned
between the adhesive layer 300 and the cellulosic veneer layer 400.
A non-limiting example of a veneer backing layer may include a
paper backing layer that is applied to the lower veneer surface 412
of a bamboo cellulosic veneer layer 400, thereby directly
contacting the lower veneer surface 412 of the bamboo cellulosic
veneer layer 400 such that the paper backing layer is positioned
between the bamboo cellulosic veneer layer 400 and upper adhesive
surface 311 of the adhesive layer 300 (not pictured).
[0044] Referring now to FIGS. 2-4, a topcoat layer 500 may be atop
the veneer layer 400. The topcoat layer 500 may be comprised of a
single integral layer (FIG. 2) or a plurality of sub-layers 540,
550, 560 (FIGS. 3 and 4). Referring now to FIG. 2, the topcoat
layer 500 may comprises an upper topcoat surface 511 and a lower
topcoat surface 512 opposite the upper topcoat surface 511. The
topcoat layer 500 may comprise a topcoat side surface 513 that
extends from the upper topcoat surface 511 to the lower topcoat
surface 512 and forms a perimeter of the topcoat layer 500. The
topcoat side surface 513 may form a portion of the major side
surface 13 of the building panel 10. Stated otherwise, the major
side surface 13 of the building panel 10 may comprise the topcoat
side surface 513. The topcoat layer 500 may have a topcoat
thickness "t.sub.TC" ranging from about 3 mils to about 20
mils--including all values and sub-ranges there-between--as
measured from the upper topcoat surface 511 to the lower topcoat
surface 512.
[0045] The topcoat layer 500 may be clear or substantially clear.
For the purposes of this application, the phrases "substantially
clear" or "substantially transparent" refers to materials that have
the property of transmitting light in such a way that a normal,
human eye (i.e., one belonging to a person with so-called "20/20"
vision) or a suitable viewing device can see through the material
distinctly. The level of transparency should generally be one which
permits a normal, human eye to distinguish objects having length
and width on the order of at least 0.5 inches, and should not
significantly distort the perceived color of the original object.
The topcoat layer 500 should be substantially clear (or
substantially transparent) such that the underlying decorative
features 30 provide by the veneer layer can be visible from the
upper major surface 11 of the building panel 10, as discussed
further herein.
[0046] The topcoat layer 500 may be formed from a topcoat
composition comprising an intumescent composition, which is
substantially clear. The intumescent composition may comprise three
components: an acid-donor compound, a carbonific compound (also
referred to as a "carbon donor compound"), and a separate blowing
agent. The topcoat composition may optionally comprise topcoat
polymer binders, fillers (e.g., silica), and other fire retarding
compounds (also referred to as "flame retardant"), as well as other
additives such as, but not limited to, adhesion promoters,
catalyst, cross-linkers, and ultra-violet stabilizers.
[0047] Upon exposure to heat, the intumescent composition is
activated by the following chain of reactions among the components:
first, the acid generated by the acid donor compound begins to
dehydrate the carbonific compound to form a char (also referred to
as a "char layer"). As the char is formed, light gases may be
generated and released (e.g., carbon monoxide, carbon dioxide). The
release of the light gases may be aided by the presence of the
separate blowing agent in the intumescent composition. The blowing
agent may separately generate and release one or more light gases
(e.g., nitrogen, carbon monoxide, carbon dioxide, methane, ammonia,
etc.). The generation and release of light gases swell and/or foam
the char layer, thereby increasing the volume and decreasing the
density of the topcoat layer 500 while forming a protective char
layer that includes pockets of air. The release of the gases leaves
a non-combustible carbonaceous material (i.e., "foamed char") that
acts as an insulative heat-barrier within the topcoat layer 500,
which enhances the high lamination integrity of the laminate
structure of the present invention at elevated temperatures. The
phrase "form a char" refers to carbonizing at least a portion of
the topcoat layer 500 from its initial coating composition into a
charred composition. The intumescing composition may react to form
the insulative heat-barrier at a minimum char temperature of at
least 130.degree. C.
[0048] The added insulative heat-barrier is especially helpful in
preventing the cellulosic veneer layer 400 from igniting at
elevated temperatures--especially when the lower major surface 12
of the building panel 10 is exposed to heat from a fire that exists
in the active room environment 2 of the ceiling system 1 (as shown
in FIG. 5). The insulative heat-barrier created by the intumescent
composition slows and prevents further propagation of heat and
flame through the topcoat layer 500 and, therefore, through the
rest of the building panel 10.
[0049] The acid-donor compound may be present in the topcoat
composition in an amount ranging from about 2 wt. % to about 20 wt.
% based on the total weight of the topcoat composition--including
all values and sub-ranges there-between. The acid-donor compound
may be a strong acid (e.g., phosphoric acid) or a compound that
forms a strong acid when exposed to heat (i.e., acid-forming
compound). Non-limiting examples of acid-donor compounds include
mono-ammonium phosphate, di-ammonium phosphate, ammonium dihydrogen
phosphate, ammonium polyphosphate, melamine phosphate, guanylurea
phosphate, urea phosphate, p-toluenesulphonic acid, phosphoric
acid, aluminum tris (dihydrogen phosphate), ammonium sulfate,
ammonium borate, and combinations thereof.
[0050] The carbonific compound may be present in the topcoat
composition in an amount ranging from about 5 wt. % to about 40 wt.
% based on the total weight of the topcoat composition--including
all values and sub-ranges there-between. The carbonific compound
may include a low molecular weight carbonaceous compound.
Non-limiting examples of low molecular weight carbonaceous
compounds include starch, erythritol, pentaerythritol, resorcinol,
inositol, sorbitol, dextrin, 2-butoxy-1-ethanol, dipropylene glycol
monomethyl ether, propylene glycol, 1-butoxy-2-propanol,
2-methoxy-2-methylethylacetate, methyl (n-amyl) ketone,
formaldehyde, melamine, methanol, methylal,
bis(methoxymethyl)ether; trimethylamine, (dimethylamino)
acetonitrile, N,N,N',N'-tetramethyl-methanediamine,
N,N-dimethyl-formamide, hexahydro-1,3,5-trimethyl-1,3,5-triazine,
methenamine, ethylene glycol, poly(vinyl butyral) and mixtures
thereof.
[0051] The carbonific compound may also include a carbonific
polymer comprising a plurality of hydroxyl groups on the backbone
that can react with the acid-donor compound during char-formation.
The carbonific polymer may be formed from a two-component system
comprising a carbonific pre-polymer and a cross-linker that cure
after the topcoat composition is applied to the cellulosic veneer
layer 400 (as discussed herein). The resulting carbonific polymer
may have a molecular weight of at least about 10,000 MW. The
presence of the hydroxyl groups on the carbonific polymer may
result in the carbonific polymer being slightly hydrophilic.
[0052] The separate blowing agent is a gas-releasing material that
may be included in the intumescent composition to achieve
additional foaming during char-formation, thereby further lowering
the density of the char layer, and in turn providing additional
insulative properties to the topcoat layer 500. The blowing agent
will begin to be activated at a temperature around that of the char
formation temperature. Non-limiting examples of blowing agent
include melamine, urea, dicyandiamide, and combination thereof. The
blowing agent may be present in the topcoat composition in an
amount that is sufficient to foam the topcoat layer 500 during char
formation--i.e., in an amount greater than 0 wt. %. According to
other embodiments, the separate blowing agent may be present in an
amount of 0 wt. % based on the total weight of the topcoat
composition because the char-forming reaction between the
acid-donor compound and the carbonific compound by itself is
sufficient to foam the topcoat composition during
char-formation.
[0053] The topcoat polymer binder may be present in the topcoat
composition in an amount ranging from about 50 wt. % to about 95
wt. %--including all values and sub-ranges there-between--based on
the total weight of the topcoat composition. The topcoat binder may
physically stabilize the intumescent composition within the topcoat
composition such that the intumescent composition has a
substantially uniform distribution throughout the resulting topcoat
layer 500.
[0054] The topcoat polymer binder may comprise polymer produced
from unsaturated monomers. Specifically, the polymer may be a
homopolymer or copolymer produced from ethylenically unsaturated
monomers, such as styrene, alpha-rnethylstyrene,
polyrnethylsiloxane, vinyl toluene, ethylene, propylene, vinyl
acetate, vinyl chloride, vinylidene chloride, acrylonitrile,
acrylamide, methacrylamide, acrylic acid, methacrylic acid,
(meth)acryloxy-propionic acid, itaconic acid, aconitic acid, maleic
acid, monomethyl maleate, monomethyl fumarate, monomethyl
itaconate, various (C.sub.1-C.sub.20) alkyl or (C.sub.3-C.sub.20)
alkenyl esters of (meth)acrylic acid, various lacquers, latex-based
binders and the like. The expression (meth)acrylic, as used herein,
is intended to serve as a generic expression embracing both acrylic
and methacrylic acid and esters thereof e.g., methyl
(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate,
isobutyl (meth)acrylate, 2-ethyl hexyl(meth)acrylate, benzyl
(meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate,
palmityl (meth)acrylate, stearyl (meth)acrylate and the like. In
other embodiments, the topcoat polymer binder may include polymer
comprising polyurethane, polyester, polyester-modified
polyurethane, or a combination thereof.
[0055] According to the present invention, the topcoat polymer
binder may comprise the carbonific polymer. Specifically, the
topcoat composition may comprise an intumescent composition
comprising an acid-donor compound, a carbonific polymer, and
optionally separate blowing agent as well as optionally low
molecular weight carbonaceous compounds. The intumescent
composition may further comprise a non-carbonific topcoat polymer
binder.
[0056] The topcoat polymer binder (including the carbonific
polymer) may have a glass transition temperature Tg ranging from
about 10.degree. C. to about 80.degree. C.--including all values
and sub-ranges there-between. The char temperature of the
intumescent composition may be at least equal to or greater than
the glass transition temperature Tg of the topcoat polymer binder.
The char temperature of the intumescent composition may be at least
about 60.degree. C. greater than the glass transition temperature
Tg of the topcoat polymer binder. Under such relationship, the
topcoat polymer binder will transition into the molten state at
least at the same time as when the intumescent composition begins
to form char within the topcoat composition, thereby facilitating
the swelling and/or foaming that occurs during char-formation. In
other embodiments, at least a portion of the topcoat polymer binder
will be in the molten state when the intumescent composition begins
to form char within the topcoat composition, thereby facilitating
the swelling and/or foaming that occurs during char-formation.
[0057] According to some embodiments, the topcoat layer 500 may
further comprise a sealant composition (also referred to as "a
sealant composition"). The sealant composition may comprise a
sealant polymer binder and a flame retardant.
[0058] The flame retardants may be present in the topcoat
composition in an amount ranging from about 0 wt. % to about 50 wt.
%--including all values and sub-ranges there-between--based on the
total weight of the topcoat composition. Non-limiting examples of
flame retardant may include ammonium hydroxide, magnesium
hydroxide, huntite, hydromagnesite, silica, polyphosphate, melamine
cyanurate, chloride salts--such as sodium chloride, antimony oxide,
and borates, such as calcium borate, magnesium borate, zinc borate,
and combinations thereof. The sealant polymer binder may be present
in the topcoat layer 500 in an amount ranging from about 5 wt. % to
about 100 wt. %--including all values and sub-ranges
there-between--based on the total weight of the sealant
composition. In some embodiments, the sealant polymer binder may be
present in the topcoat layer 500 in an amount ranging from about 10
wt. % to about 95 wt. %--including all values and sub-ranges
there-between--based on the total weight of the sealant
composition.
[0059] The sealant polymer binder may comprise one or more vinyl or
acrylic homopolymers or copolymers formed from ethylenically
unsaturated monomers such as ethylene or butadiene and vinyl
monomers such as styrene, vinyl esters such as vinyl acetate, vinyl
propionate, vinyl butyrates, acrylic acid, methacrylic acid, or
esters of acrylic acid and/or esters of methacrylic acid. The
esters of acrylic or methacrylic acid may have an alkyl ester
portion containing 1 to 12 carbon atoms as well as aromatic
derivatives of acrylic and methacrylic acid, and can include, for
example, acrylic and methacrylic acid, methyl acrylate and methyl
methacrylate, ethyl acrylate and ethyl methacrylate, butyl acrylate
and butyl methacrylate, propyl acrylate and propyl methacrylate,
2-ethyl hexyl acrylate and 2-ethyl hexyl methacrylate, cyclohexyl
acrylate and cyclohexyl methacrylate, decyl acrylate and decyl
methacrylate, isodecyl acrylate and isodecyl methacrylate, benzyl
acrylate and benzyl methacrylate and various reaction products such
as butyl, phenyl, and cresyl glycidyl ethers reacted with acrylic
and methacrylic acids. In a preferred embodiment, the sealant
binder comprises a self-crosslinking acrylic binder.
[0060] According to such embodiments, the topcoat layer 500 is a
single integrally formed layer whereby the intumescent composition
and the sealant composition and blended together and located
between the upper topcoat surface 511 and the lower topcoat surface
512 and surrounded by the topcoat side surface 513 of the topcoat
layer 500. In other embodiments, the topcoat layer 500 may comprise
the intumescent composition and only the flame retardant while
being substantially free of the sealant polymer. In other
embodiments, the topcoat layer 500 may comprise the intumescent
composition and be substantially free of the sealant
composition.
[0061] The topcoat layer 500 may be formed by applying the top coat
composition directly to the upper cellulosic veneer surface 411 of
the cellulosic veneer layer 400, optionally with the addition of a
carrier such as water or a VOC-based solvent (i.e., volatile
organic compound). The topcoat composition and carrier may be
applied by spray, roll-coating, dip coating, curtain coating,
brushing, blade coating, or the like. The topcoat composition may
then be cured (optionally with the addition of heat) for a period
of time, thereby forming the topcoat layer 500 atop the cellulosic
veneer layer 400. As previously discussed, the cellulosic veneer
layer 400 may comprise pores on the upper cellulosic veneer surface
411. Thus, once the topcoat composition is applied to the upper
cellulosic veneer surface 411 of the cellulosic veneer layer 400,
at least a portion of the top coat composition may penetrate into
the pores present in the cellulosic veneer layer 400 in a direction
extending from the upper cellulosic veneer surface 411 toward the
lower cellulosic veneer surface 412.
[0062] The building panel 10 of the present invention may comprise
a laminate structure wherein the topcoat layer 500 is atop the
cellulosic veneer layer 400, the cellulosic veneer layer 400 is
atop the adhesive layer 300, and the adhesive layer is atop the
substrate 200 layer. The overall panel thickness t.sub.P of the
building panel 10 may be the summation of the substrate thickness
t.sub.S, the adhesive thickness t.sub.A, the cellulosic veneer
thickness t.sub.v, and the topcoat thickness t.sub.TC as
follows:
t.sub.P-t.sub.S+t.sub.A+t.sub.v+t.sub.TC
[0063] The upper substrate surface 211 of the substrate layer 200
may directly contact the lower adhesive surface 312 of the adhesive
layer 300 and the upper adhesive surface 311 of the adhesive layer
300 may directly contact the lower cellulosic veneer surface 412 of
the cellulosic veneer layer 400 such that the adhesive layer 300
adhesively bonds together the cellulosic veneer layer 400 and the
substrate layer 200. The lower topcoat surface 512 may directly
contact the upper cellulosic veneer surface 411, such that the
upper topcoat surface 511 forms at least a portion of the upper
major surface 11 of the building panel 10. The lower substrate
surface 212 may form at least a portion of the lower major surface
12 of the building panel 10.
[0064] Referring now to FIG. 3, other embodiments of the present
invention include a topcoat layer 500 comprising a first sub-layer
540 and a second sub-layer 550. The first sub-layer 540 may be
directly atop the cellulosic veneer layer 400 and the second
sub-layer 550 may be directly atop the first sub-layer 540.
[0065] The first sub-layer 540 may comprise a sealant composition
(also referred to as "a sealant composition"). The sealant
composition may comprise a sealant polymer binder and a flame
retardant. The sealant polymer binder may be present in the
cellulosic-layer sealant composition in an amount ranging from
about 50 wt. % to about 100 wt. %--including all values and
sub-ranges there-between--based on the total weight of the sealant
composition. The flame retardant may be present in the
cellulosic-layer sealant composition in an amount ranging from
about 0 wt. % to about 50 wt. %--including all values and
sub-ranges there-between--based on the total weight of the
cellulosic-layer sealant composition.
[0066] The sealant polymer binder may comprise one or more vinyl or
acrylic homopolymers or copolymers formed from ethylenically
unsaturated monomers such as ethylene or butadiene and vinyl
monomers such as styrene, vinyl esters such as vinyl acetate, vinyl
propionate, vinyl butyrates, acrylic acid, methacrylic acid, or
esters of acrylic acid and/or esters of methacrylic acid. The
esters of acrylic or methacrylic acid may have an alkyl ester
portion containing 1 to 12 carbon atoms as well as aromatic
derivatives of acrylic and methacrylic acid, and can include, for
example, acrylic and methacrylic acid, methyl acrylate and methyl
methacrylate, ethyl acrylate and ethyl methacrylate, butyl acrylate
and butyl methacrylate, propyl acrylate and propyl methacrylate,
2-ethyl hexyl acrylate and 2-ethyl hexyl methacrylate, cyclohexyl
acrylate and cyclohexyl methacrylate, decyl acrylate and decyl
methacrylate, isodecyl acrylate and isodecyl methacrylate, benzyl
acrylate and benzyl methacrylate and various reaction products such
as butyl, phenyl, and cresyl glycidyl ethers reacted with acrylic
and methacrylic acids. In a preferred embodiment, the sealant
binder comprises a self-crosslinking acrylic binder.
[0067] The flame retardant of the first sub-layer 540 may include
ammonium hydroxide, magnesium hydroxide, huntite, hydromagnesite,
silica, polyphosphate, melamine cyanurate, chloride salts--such as
sodium chloride, antimony oxide, and borates, such as calcium
borate, magnesium borate, zinc borate, and combinations
thereof.
[0068] The first sub-layer 540 may be formed by applying the
sealant composition in a wet-state directly to the upper cellulosic
veneer surface 411 of the cellulosic veneer layer 400. The
wet-state sealant composition may further comprise a carrier in an
amount ranging from about 20 wt. % to about 60 wt. %--including all
values and sub-ranges there-between--based on the total weight of
the wet-state cellulosic-layer sealant composition. The carrier may
be selected from water, an organic solvent, or a combination
thereof. In a preferred embodiment, the wet-state sealant
composition is a waterborne system having a carrier of water and a
low VOC (i.e., volatile organic compound) content--i.e.
substantially free of VOC solvents. The sealant binder may be
self-crosslinking.
[0069] The sealant composition may then be cured (optionally with
the addition of heat) for a first time period, thereby forming the
first sub-layer 540 atop the cellulosic veneer layer 400. The
resulting first sub-layer 540 may comprise a first sub-layer upper
surface 541 and a first sub-layer lower surface 542 opposite the
first sub-layer upper surface 541. The first sub-layer 540 may have
a first sub-layer thickness "t.sub.TC1" as measured from the first
sub-layer upper surface 541 to the first sub-layer lower surface
542. The first sub-layer thickness t.sub.TC1 may range from 1 mils
to 6 mils--including all values and sub-ranged there-between. The
first sub-layer 540 may comprise a first sub-layer side surface 543
that extends from the first sub-layer upper surface 541 to the
first sub-layer lower surface 542 and forms a perimeter of the
first sub-layer 540.
[0070] The second sub-layer 550 may be formed by directly applying
the previously discussed topcoat composition (i.e., comprising the
intumescent composition and optionally the topcoat polymer binder)
to the first sub-layer upper surface 541 of the first sub-layer
540. The topcoat composition may then be cured (optionally with the
addition of heat) for a second time period of time, thereby forming
the second sub-layer 550 atop the first sub-layer 540. The
resulting second sub-layer 550 may comprise a second sub-layer
upper surface 551 and a second sub-layer lower surface 552 opposite
the second sub-layer upper surface 551.
[0071] The second sub-layer 550 may have a second sub-layer
thickness "t.sub.TC2" as measured from the second sub-layer upper
surface 551 to the second sub-layer lower surface 552. The second
sub-layer thickness t.sub.TC2 may range from about 3 mils to about
20 mils. The second sub-layer 550 may comprise a second sub-layer
side surface 553 that extends from the second sub-layer upper
surface 551 to the second sub-layer lower surface 552 and forms a
perimeter of the second sub-layer 550.
[0072] The first sub-layer side surface 543 and the second
sub-layer side surface 553 may form at least a portion of the
topcoat side surface 513. Stated otherwise, the topcoat side
surface 513 may comprise the first sub-layer side surface 543 and
the second sub-layer side surface 553. The overall topcoat
thickness t.sub.TC of topcoat layer 500 may be the summation of the
first sub-layer thickness t.sub.TC and the second sub-layer
thickness t.sub.TC2--as follows:
t.sub.TC=t.sub.TC1+t.sub.TC2
[0073] According to these embodiments, the first sub-layer lower
surface 542 of the first sub-layer 540 may contact the upper
cellulosic veneer surface 411 of the cellulosic veneer layer 400.
The first sub-layer upper surface 541 may contact the second
sub-layer lower surface 552 of the second sub-layer 550. The second
sub-layer upper surface 551 may form at least part of the upper
topcoat surface 511 of the topcoat layer 500. The first sub-layer
lower surface 542 may form at least part of the lower topcoat
surface 512 of the topcoat layer 500. The second sub-layer upper
surface 551 may form at least part of the upper major surface 11 of
the building panel 10.
[0074] As previously discussed, the cellulosic veneer layer 400 may
comprise pores on the upper cellulosic veneer surface 411. Once the
cellulosic-layer sealant composition of the first sub-layer 540 is
applied to the upper cellulosic veneer surface 411 of the
cellulosic veneer layer 400, at least a portion of the
cellulosic-layer sealant composition may penetrate into the pores
present in the cellulosic veneer layer 400 in a direction extending
from the upper cellulosic veneer surface 411 towards the lower
cellulosic veneer surface 412. As a result, the first sub-layer 540
may form a physical barrier that at least partially seals the upper
cellulosic veneer surface 411 of the cellulosic veneer layer 400
from the second sub-layer 550. The physical barrier formed by the
first sub-layer 540 may prevent at least some of the second
sub-layer 550 (which comprises the intumescent composition) from
penetrating into the pores on the upper cellulosic veneer surface
411 of the cellulosic veneer layer 400. According to some
embodiments, the char-forming insulative barrier that is created by
intumescent composition of the second sub-layer 540 may be
separated from the upper cellulosic veneer surface 411 of the
cellulosic veneer layer 400 by a distance equal to the first
sub-layer thickness t.sub.TC1.
[0075] Referring now to FIG. 4, other embodiments provide that the
topcoat layer 500 may further comprise a third sub-layer 560 atop
the second sub-layer 550, which is atop the first sub-layer 540
that is atop the cellulosic veneer layer 400. The third sub-layer
560 may be formed from a moisture barrier composition that imparts
moisture barrier properties to the resulting third sub-layer 560.
The moisture barrier composition may be comprised of hydrophobic
polymeric binder, which may or may not be cross-linked, as well as
various additives and fillers. Non-limiting examples of hydrophobic
polymeric binder produced from unsaturated monomers. Specifically,
the hydrophobic polymer may be a homopolymer or copolymer produced
from ethylenically unsaturated monomers, such as styrene,
alpha-methylstyrene, vinyl toluene, ethylene, propylene, vinyl
acetate, vinyl chloride, vinylidene chloride, acrylonitrile,
acrylamide, methacrylamide, acrylic acid, methacrylic acid,
(meth)acryloxy-propionic acid, itaconic acid, aconitic acid, maleic
acid, monomethyl maleate, monomethyl fumarate, monomethyl
itaconate, various (C.sub.1-C.sub.20) alkyl or (C.sub.20) alkenyl
esters of (meth)acrylic acid and the like. The expression
(meth)acrylic, as used herein, is intended to serve as a generic
expression embracing both acrylic and methacrylic acid and esters
thereof e.g., methyl (meth)acrylate, ethyl (meth)acrylate, butyl
(meth)acrylate, isobutyl (meth)acrylate, 2-ethyl
hexyl(meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate,
oleyl (meth)acrylate, palmityl (meth)acrylate, stearyl
(meth)acrylate and the like. In other embodiments, the hydrophobic
polymeric binder may include polymer comprising polyurethane,
polyester, polyester-modified polyurethane, epoxy or a combination
thereof.
[0076] The hydrophobic polymer may be present in an amount ranging
from about 70 wt. % to about 100 wt. %--including all values and
sub-ranges there-between--based on the total weight of the moisture
barrier composition.
[0077] The third sub-layer 560 may be formed by applying the
moisture barrier composition with the addition of one or more
organic solvents. Non-limiting examples of organic solvents include
toluene, ethanol, acetone, butyl acetate, methyl ethyl ketone,
ethyl 3-ethoxypropionate. The barrier composition may be present
relative to the organic solvent in a weight ratio ranging from
about 5:1 to about 1:20. After application to the second sub-layer
upper surface 551, the moisture barrier composition may be dried
for a third period of time, optionally at an elevated temperature,
sufficient to drive off any organic solvent. The resulting third
sub-layer 560 may be a continuous or discontinuous coating having
an third sub-layer upper surface 561 and a third sub-layer lower
surface 562 opposite the third sub-layer upper surface 561. The
third sub-layer 560 may have a third sub-layer thickness
"t.sub.TC3" as measured from the third sub-layer upper surface 561
to the third sub-layer lower surface 562. The third sub-layer
thickness t.sub.TC3 may range from about 1 mils to about 6 mils.
The third sub-layer 560 may comprise a third sub-layer side surface
563 that extends from the third sub-layer upper surface 561 to the
third sub-layer lower surface 562 and forms a perimeter of the
second sub-layer 560.
[0078] According to such embodiments, the overall topcoat thickness
t.sub.TC of topcoat layer 500 may be the summation of the first
sub-layer thickness t.sub.TC1, the second sub-layer thickness
t.sub.TC2, and the third sub-layer thickness t.sub.TC3--as
follows:
t.sub.TC=t.sub.TC1+t.sub.TC2+t.sub.TC3
[0079] According to these other embodiments, the first sub-layer
lower surface 542 of the first sub-layer 540 may contact the upper
cellulosic veneer surface 411 of the cellulosic veneer layer 400.
The first sub-layer upper surface 541 may contact the second
sub-layer lower surface 552 of the second sub-layer 550. The second
sub-layer upper surface 551 may contact the third sub-layer lower
surface 562 of the second sub-layer 560. The third sub-layer upper
surface 561 may form at least part of the upper topcoat surface 511
of the topcoat layer 500. The first sub-layer lower surface 542 may
form at least part of the lower topcoat surface 512 of the topcoat
layer 500. The third sub-layer upper surface 561 may form at least
part of the upper major surface 11 of the building panel 10.
[0080] According to other embodiments, the topcoat layer 500 may
comprise only the second sub-layer 550 and the third sub-layer 560
without the first sub-layer 540 (not pictured). In such
embodiments, the second sub-layer 550 may be directly atop the
upper cellulosic veneer surface 411 of the cellulosic veneer layer
400 and the third sub-layer 560 may be directly atop the second
sub-layer upper surface 551 of the second sub-layer 550. In such
embodiments, the second sub-layer 550 acts as a sealant and is
capable of sealing the porous upper cellulosic veneer surface 411
of the cellulosic veneer layer 400, while simultaneously acting as
a char-forming intumescent layer.
[0081] According to other embodiments, the topcoat layer 500 may
comprise only the second sub-layer 550. In such embodiments, the
second sub-layer 550 acts as a sealant and is capable of sealing
the porous upper cellulosic veneer surface 411 of the cellulosic
veneer layer 400, while simultaneously acting as a char-forming
intumescent layer, in situations where moisture resistance of the
coating is not required.
[0082] The building panel 10 of the present invention may be formed
by first cleaning or degreasing the upper major surface of the
substrate layer by either mechanical or chemical means, or a
combination thereof. Non-limiting examples of degreasing may
include sand blasting, or using a chemical bath to clean the
surfaces of the substrate. The adhesive composition may then be
heated to an application temperature ranging from about 120.degree.
C. to about 160.degree. C., thereby lowering the viscosity of the
adhesive composition to a flowable liquid or semi-liquid state. The
adhesive composition may then be applied to at least one of the
upper substrate surface 211 or the lower cellulosic veneer surface
412. The adhesive composition may be applied by roll coating, spray
coating, dip coating, or the like.
[0083] The adhesive composition of the present invention may
develop significant green strength within about 30 seconds of being
applied to at least one of the substrate layer or the cellulosic
veneer layer 400. The adhesive composition may also have an open
time up to about 60 seconds after being applied to the substrate
layer 200. Before the open time expires, the upper substrate
surface 211 is mated to the lower cellulosic veneer surface 412
with the adhesive composition being present there-between, thereby
bonding the upper substrate surface 211 to the lower cellulosic
veneer surface 412 via the adhesive composition. Pressure may then
be applied to at least one of the upper cellulosic veneer surface
411 of the cellulosic veneer layer 400 or the lower substrate
surface 212 of the substrate layer 200 to ensure proper adhesive
bonding.
[0084] Each sub-layer 540, 550, 560 may be individually applied by
spray, roll-coating, dip coating, curtain coating, brushing, blade
coating, or the like. Specifically, the first sub-layer 540 may be
applied to the upper cellulosic veneer surface 411 of the
cellulosic veneer layer 400. The first sub-layer 540 may then be
optionally heated to a temperature ranging from about 10.degree. C.
to about 60.degree. C. to partially or fully cure the first
sub-layer 540. The second sub-layer 550 may then be applied to the
first sub-layer supper surface upper surface 541. The second
sub-layer 550 may then be optionally heated to a temperature
ranging from about 10.degree. C. to about 60.degree. C. to
partially or fully cure the second sub-layer 550. The third
sub-layer 560 may then be applied to the second sub-layer upper
surface 551. The third sub-layer 560 may then be optionally heated
to a temperature ranging from about 10.degree. C. to about
60.degree. C. to partially or fully cure the third sub-layer
560--thereby resulting in the laminate structure of the present
invention. The laminate structure may then be heated in an oven to
fully cure the adhesive layer 300 and the topcoat layer 500 for a
fourth period of time.
[0085] According to the present invention, a laminate structure
comprising the adhesive layer 300 and the topcoat layer 500 in
combination with the cellulosic veneer layer 400 and substrate
layer 200 results in a building panel 10 having superior lamination
integrity during not only normal use in an interior environment,
but also during a fire in the active room environment 2.
Specifically, two mechanisms achieve superior performance. The
polyester-modified polyurethane allows for hot-melt application of
the adhesive that quickly forms significant green strength and does
not sacrifice the open time that is needed to properly apply the
adhesive composition during manufacture. Additionally, the presence
of moisture-cured polymers in the adhesive increases the degree of
cross-linking in the polymeric binder, increasing the softening
temperature of the adhesive, which in turn delays delamination at
high temperatures. The resulting adhesive layer exhibits superior
performance during manufacture and under high temperature
conditions that translates into a substantial delay in the
deformation of the adhesive layer 300 under a load at elevated
temperatures, thereby delaying delamination of the veneer layer 400
from the substrate layer 200 at elevated temperatures--especially
those resulting from a fire in the active room environment 2.
[0086] Furthermore, the intumescent composition of the topcoat
layer 500 helps provide an insulative heat-barrier to the
cellulosic veneer layer 400, thereby helping prevent the cellulosic
veneer layer 400 from igniting during a fire and propagating
through the building panel 10. The multi-layered topcoat layer 500
comprising the cellulosic-layer sealant first sub-layer 540 may
also at least partially seal the pores and the upper cellulosic
veneer surface 411 such that at least a portion of the char-forming
insulative barrier is formed at a distance separated from the upper
cellulosic veneer surface 411 of the cellulosic veneer layer
400--further protecting the cellulosic veneer layer 400 from
igniting in a fire. Additionally, the moisture sealant composition
of the third sub-layer 560 ensures that the intumescent composition
of the underlying sub-layers 540, 550 remains active for prolonged
periods of time in case an interior space catches fire years after
initial installation.
[0087] Referring to FIG. 5, the building panel 10 of the present
invention may be a ceiling panel (as shown installed in the ceiling
system of FIG. 5), a wall panel, or the like. The lower major
surface 12 of the ceiling panel 10 of the present invention may
face the plenum space 3 of an interior space of a ceiling system 1.
The upper major surface 11 of the ceiling panel 10 of the present
invention may face the active space 2 of an interior space of a
ceiling system 1.
[0088] The laminate structure of the present invention results in a
building panel 10 that meets at least the Class B, preferably Class
A, fire rating as measured by the methodology set forth in ASTM
E84--Standard Test Method for Surface Burning Characteristics of
Building Materials--without the aid of external supports one or
more of the major surfaces 11, 12 of the building panel 10--such as
rods, bars and/or chicken wire.
[0089] In non-exemplified embodiments, the present invention may
include a building panel having an upper major surface opposite a
lower major surface, the building panel comprising a cellulosic
layer (also referred to as "cellulosic substrate" in this
embodiment) and a topcoat layer. The cellulosic substrate is
self-supporting and comprises an upper cellulosic surface and a
lower cellulosic surface opposite the upper cellulosic surface.
Non-limiting examples of a cellulosic substrate may include MDF
board, wooden planks, or the like. The cellulosic substrate may
have a cellulosic substrate thickness as measured from the lower
cellulosic surface to the upper cellulosic surface that ranges up
to about 3 inches--including all values and sub-ranges
there-between.
[0090] The building panel of such embodiments may have the topcoat
layer applied to at least one of the upper cellulosic surface or
the lower cellulosic surface of the cellulosic layer. The topcoat
layer comprises an upper topcoat surface opposite a lower topcoat
surface. According to such embodiments, the lower topcoat surface
of the topcoat may directly contact the upper cellulosic surface of
the cellulosic substrate. The topcoat layer comprises at least the
second sub-layer and optionally the first sub-layer and the third
sub-layer, as previously discussed. The upper major surface of the
building panel may comprise the upper topcoat surface of the
topcoat layer and the lower major surface of the building panel may
comprise the lower cellulosic surface of the cellulosic layer.
[0091] The following examples are prepared in accordance with the
present invention. The present invention is not limited to the
examples described herein.
EXAMPLES
Experiment 1
[0092] A first experiment was performed by preparing two building
panels according to the following methodology. A wood veneer layer
was adhered to an aluminum substrate layer using a hot-melt
polyurethane adhesive containing flame retardant. The wood veneer
layer has a thickness of about 30 mils and the aluminum substrate
has a thickness of about 27 mils. For one of the building panels,
the exposed upper surface of the wood veneer layer was coated with
a traditional UV-curable topcoat coating comprising
acrylate-functional polymer, resulting in a topcoat thickness
ranging from about 1 mil to about 2 mils. The other building panel
remained uncoated. Each of the building panels were then subjected
to an ASTM E-84 test to measure surfaces flame spread and smoke
density. The results are provided below in Table 1.
TABLE-US-00001 TABLE 1 Ex. 1 Control Ex. 1 Aluminum Substrate
Thickness (mils) 40 40 Topcoat Y N Flame Retardant in Topcoat N N
Flame Spread 235 235 Smoke Developed 70 75 Classification NC NC
[0093] As demonstrated by Table 1, the presence of the UV-curable
coating--a traditional coating choice for such products--did not
change the fire performance of this construction. The construction
is deemed not classifiable or "NC" by the building code, with or
without the coating.
Experiment 2
[0094] A second experiment was performed by preparing two building
panels according to the following methodology. A wood veneer layer
was adhered to a aluminum substrate layer using a hot-melt
polyurethane adhesive containing flame retardant. The wood veneer
layer has a thickness of about 30 mils and the aluminum substrate
has a thickness of about 40 mils. For one of the building panels,
the exposed upper surface of the wood veneer layer was coated with
a water-borne acrylic coating that resulted in a topcoat thickness
ranging from about 1 mil to about 2 mils. The other building panel
remained uncoated. Each of the building panels were then subjected
to an ASTM E-84 test to measure surfaces flame spread and smoke
density. The results are provided below in Table 2.
TABLE-US-00002 TABLE 2 Ex. 2 Control Ex. 2 Aluminum Substrate
Thickness (mils) 40 40 Topcoat Y N Flame Retardant in Topcoat N --
Flame Spread 40 235 Smoke Developed 60 75 Classification B NC
[0095] As demonstrated by Table 2, the presence of the topcoat
improved the fire performance of the building panel. However, to
receive a Class A rating, the building code requires a flame spread
of 25 or less, and smoke developed of less than 450. Consequently,
the fire performance of Experiment 2 still requires
improvement.
Experiment 3
[0096] A third experiment was performed by preparing an additional
building panel according to the same methodology of Experiment 2
except that the upper surface of the wood veneer layer was coated
with the water-borne acrylic coating that was further modified to
contain 8 wt. % of flame retardant. The resulting topcoat had a
thickness ranging from about 1 mil to about 2 mils. The building
panel of Experiment 3 was then subjected to an ASTM E-84 test to
measure surfaces flame spread and smoke density. The results of
Experiments 2 and 3 are provided below in Table 3.
TABLE-US-00003 TABLE 3 Ex. 3 Ex. 2 Control Ex. 2 Aluminum Substrate
Thickness (mils) 40 40 40 Topcoat Y Y N Flame Retardant in Topcoat
Y N -- Flame Spread 45 40 235 Smoke Developed 75 60 75
Classification B B NC
[0097] As demonstrated by Table 3, when accounting for the known
test result variations between Experiments 2 and 3, the addition of
the traditional flame retardant to the topcoat had no impact on the
fire performance (as measured by the ASTM E-84 test) of the
construction as compared to the material without flame retardant.
Consequently, an improved, non-traditional flame barrier is
required.
Experiment 4
[0098] A fourth experiment was performed to test a single topcoat
layer comprising sealant and an intumescent composition--whereby
the fourth experiment was performed by preparing a first building
panel according to a methodology of the present invention and a
second building panel that is uncoated as a control.
[0099] A wood veneer layer was adhered to an aluminum substrate
layer using a hot-melt polyurethane adhesive containing flame
retardant. The wood veneer layer has a thickness of about 30 mils
and the aluminum substrate has a thickness of about 40 mils. For
one of the building panels, the exposed upper surface of the wood
veneer layer was coated with a wood sealant in a west-state
comprising an inorganic salt flame retardant as well as a 3-part
intumescent composition that comprises (1) pentaerthritol in an
amount ranging from about 5 wt. % to about 40 wt. %, (2) poly
(vinyl butyral) in an amount ranging from about 5 wt. % to about 40
wt. %, and (3) antimony pentoxide in an amount ranging from about 1
wt. % to about 5 wt. %--all amounts are based on the total weight
of the wet-state topcoat and the remaining amounts being a carrier.
The wood sealant further comprises silica. The resulting topcoat
has a thickness ranging from about 2 mils to about 5 mils, and a
total application weight of about 55 g/ft.sup.2 to about 60
g/ft.sup.2. The other building panel remained uncoated. Each of the
building panels were then subjected to an ASTM E-84 test to measure
surfaces flame spread and smoke density. The results are provided
below in Table 4.
TABLE-US-00004 TABLE 4 Ex. 4 Control Ex. 3 Aluminum Substrate
Thickness (mils) 40 40 Sealant Topcoat Y N Flame Retardant in
Topcoat Y -- Intumescent in Topcoat Y -- Flame Spread 20 235 Smoke
Developed 110 75 Classification A NC
[0100] As demonstrated by Table 4, the addition of the intumescent
composition shifted the fire rating to one that had a Class A fire
spread according to ASTM E-84.
Experiment 5
[0101] A fifth experiment was performed to test separate layers of
a topcoat sealant and an intermediate layer comprising an
intumescent composition--whereby the fifth experiment was performed
by preparing five building panels according to a methodology of the
present invention and a sixth building panel that is uncoated as a
control.
[0102] A wood veneer layer was adhered to an aluminum substrate
layer using a hot-melt polyurethane adhesive containing flame
retardant. The wood veneer layer has a thickness of about 30 mils.
The aluminum substrate used has a thickness ranging from about 40
mils to about 62 mils--as described further herein. Four of the
building panels had the exposed upper surface of the wood veneer
layer coated with an intermediate coating that included an
intumescent composition comprising polyphosphate comprised of
phosphoric acid or polyphosphate formed from phosphoric acid in an
amount ranging from about 5 wt. % to about 25 wt. % and
amine-containing compounds comprising melamine, trimethyl amine,
and methenamine in an amount ranging from about 5 wt. % to about 25
wt. %--all amounts are based on the total weight of the
intermediate layer in the wet-state and the remaining amounts being
a carrier. The intermediate coating further comprises silica in an
amount ranging from a non-zero value up to about 5 wt. % based on
the total weight of the intermediate layer. The resulting
intermediate coating for the four building panels having
thicknesses ranging from about 2 mils to about 4 mils. A topcoat of
a standard commercial clear lacquer sealant comprised of various
hydrocarbons was then applied to the intermediate coating to
provide a barrier of moisture protection to the intumescent
coating. The veneer layer of the sixth building panel of this
experiment remained uncoated.
[0103] Each of the building panels were then subjected to an ASTM
E-84 test to measure surfaces flame spread and smoke density. The
results are provided below in Table 5.
TABLE-US-00005 TABLE 5 Control Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 4
Aluminum Substrate 40 40 40 50 62 40 Thickness (mils) Sealant
Topcoat Y Y Y Y Y N Flame Retardant in Topcoat N N N N N -- Flame
Retardant in N N N N N -- Intermediate Coat Intumescent in Y Y Y Y
Y -- Intermediate Coat Application Rate of 18 30 45 28 30 --
Intermediate Coat (g/ft.sup.2) Flame Spread 10 15 20 25 25 235
Smoke Developed 100 110 115 90 70 75 Classification A A A A A
NC
[0104] As demonstrated by Table 5, the addition of the intumescent
composition shifted the fire rating to one that had a superior
flame spread rating across a range of application rates and
aluminum thicknesses. Additionally, superior fire rating was still
achieved even with the sealant topcoat, thereby enhancing moisture
resistance to the veneer layer of the building panel. Although
there was a slight decrease in performance of smoke developed
rating for the panels of Experiments 5 to 9 as compared to Control
Example 4, the panels of Experiments 5 to 9 still performed well
below the required threshold of 450--this consideration for smoke
developed is the same for all following experiments and
examples.
Experiment 6
[0105] A sixth experiment was performed to test separate layers of
a topcoat sealant and an intermediate layer comprising an
intumescent composition--whereby the sixth experiment was performed
by preparing one building panels according to a methodology of the
present invention and a second building panel that is uncoated as a
control.
[0106] A wood veneer layer was adhered to an aluminum substrate
layer using a hot-melt polyurethane adhesive containing flame
retardant. The wood veneer layer has a thickness of about 30 mils
and the aluminum substrate has a thickness of about 50 mils. For
one of the building panels, the exposed upper surface of the wood
veneer layer was coated with an intermediate coat comprising a
phosphate based flame retardant and intumescent composition. The
intumescent composition comprises organo and polyphosphates in an
amount ranging from about 5 wt. % to about 80 wt. % as well as
hydroxyl compounds including alcohols such as methanol and
isopropanol in an amount ranging from about 5 wt. % to about 50 wt.
%--the amounts are based on the total weight of the intermediate
layer in the wet-state. The intermediate layer further comprises
silica in an amount ranging from a non-zero value up to about 5 wt.
% based on the total weight of the intermediate layer in the wet
state. The remaining amounts of the intermediate layer in the
wet-state being a carrier. A topcoat of sealant of a standard
commercial clear lacquer was then applied to the intermediate
coating to provide a barrier of moisture protection to the
intumescent coating. The total thickness of the intermediate
coating and the topcoat ranges from about 2 mil to about 4 mils.
The other building panel remained uncoated. Each of the building
panels were then subjected to an ASTM E-84 test to measure surfaces
flame spread and smoke density. The results are provided below in
Table 6.
TABLE-US-00006 TABLE 6 Ex. 10 Control Ex. 5 aluminum Substrate
Thickness (mils) 50 50 Sealant Topcoat Y N Flame Retardant in
Topcoat Y -- Intumescent in Intermediate coat Y -- Flame Spread 25
50 Smoke Developed 55 70 Classification A B
[0107] As demonstrated by Table 6, the addition of the intumescent
composition shifted the fire rating to one that had a Class A flame
spread according to ASTM E-84.
Experiment 7
[0108] A seventh experiment was performed to test a single topcoat
layer comprising a sealant and intumescent composition--whereby the
seventh experiment was performed by preparing four building panels
according to a methodology of the present invention and a fifth
building panel that is uncoated as a control.
[0109] A wood veneer layer was adhered to an aluminum substrate
layer using a hot-melt polyurethane adhesive containing flame
retardant. The wood veneer layer has a thickness of about 30 mils.
The aluminum substrate used has a thickness ranging from about 40
mils to about 62 mils--as described further herein. Four of the
building panels had the exposed upper surface of the wood veneer
layer coated with a topcoat comprising an aqueous wood sealant
comprising acrylic polymer/co-polymer blend, ethanol and ether
compounds from about 5 wt. % to about 95 wt. % and as well as an
intumescent composition comprising polyphosphates such as
phosphoric acid in an amount ranging from about 20 wt. % to about
40% wt. %, organophosphates in an amount ranging from about 30 wt.
% to about 40 wt. %, butoxy ethanol in an amount less than about 10
wt. %, sulphonic acid in an amount ranging from about 30 wt. % to
about 50 wt. %, and polyalkylene oxide modified
polydimethylsiloxane in an amount less than 5 wt. %--the amounts
being based on the total weight of the topcoat in the wet-state and
the remaining amounts being a carrier. The wet-state topcoat
coating further comprises silica in an amount ranging from about 5
wt. % to about 15 wt. % based on the total weight of the topcoat in
the wet-state. The topcoat on each of first four building panels
had a thicknesses ranging from about 2 mils to about 4 mils. The
veneer layer of the fifth building panel of this experiment
remained uncoated.
[0110] Each of the building panels were then subjected to an ASTM
E-84 test to measure surfaces flame spread and smoke density. The
results are provided below in Table 7.
TABLE-US-00007 TABLE 7 Control Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 6
Aluminum Substrate 40 40 40 62 40 Thickness (mils) Sealant Topcoat
Y Y Y Y N Flame Retardant in Y Y Y Y -- Topcoat Intumescent in Y Y
Y Y -- Topcoat Application Rate of 33 42 46 42 -- Intermediate Coat
(g/ft.sup.2) Flame Spread 15 15 20 15 235 Smoke Developed 120 110
110 170 75 Classification A A A A NC
[0111] As demonstrated by Table 7, the addition of the intumescent
system shifted the fire rating to one that had a Class A flame
spread according to ASTM E-84 across a range of application rates
and thicknesses of aluminum.
Experiment 8
[0112] An eighth experiment was performed to test separate layers
of a topcoat sealant and an intermediate layer comprising an
intumescent composition--whereby the eighth experiment was
performed by preparing one building panels according to a
methodology of the present invention and a second building panel
that is uncoated as a control.
[0113] A wood veneer layer was adhered to an aluminum substrate
layer using a hot-melt polyurethane adhesive containing flame
retardant. The wood veneer layer has a thickness of about 30 mils
and the aluminum substrate has a thickness of about 40 mils. For
one of the building panels, the exposed upper surface of the wood
veneer layer was coated with an intermediate coat comprising a
flame retardant and intumescent composition. The intumescent
composition comprises phosphoric acid in an amount ranging from
about 5 wt. % to about 65 wt. % and dihydrogen phosphate in an
amount ranging from about 5 wt. % to about 35 wt. %--the amounts
are based on the total weight of the intermediate layer in the
wet-state and the remaining amounts being a carrier. A topcoat of
standard commercial clear lacquer sealant was then applied to the
intermediate coating to provide a barrier of moisture protection to
the intumescent coating. The total thickness of the intermediate
coating and the topcoat ranges from about 4 mils to about 6 mils.
The other building panel remained uncoated. Each of the building
panels were then subjected to an ASTM E-84 test to measure surfaces
flame spread and smoke density. The results are provided below in
Table 8.
TABLE-US-00008 TABLE 8 Ex. 15 Control Ex. 7 Aluminum Substrate
Thickness (mils) 40 40 Sealant Topcoat Y N Flame Retardant in
Topcoat N -- Intumescent in Intermediate coat Y -- Flame Spread 10
235 Smoke Developed 135 75 Classification A NC
[0114] As demonstrated by Table 8, the addition of the intumescent
composition shifted the fire rating to one that had a Class A flame
spread according to ASTM E-84.
[0115] It is to be understood that other embodiments may be
utilized and structural and functional modifications may be made
without departing from the scope of the present invention. Thus,
the spirit and scope of the invention should be construed broadly
as set forth in the appended claims.
* * * * *