Note: Descriptions are shown in the official language in which they were submitted.
CA 02597955 2007-08-17
A RESIN COMPOSITION AND AN ARTICLE FORMED THEREFROM
FIELD OF THE INVENTION
[0001] The present invention generally relates to a resin composition and an
article formed therefrom. More specifically, the present invention relates to
an article
that exhibits excellent dimensional stability and adhesion strength while
exceeding Class
I flammability requirements for building materials due to a resin composition
that is used
to form the article.
DESCRIPTION OF THE RELATED ART
[0002] Surface burning characteristics of materials are determined by test
methods such as the American Society of Testing Materials (ASTM) E-84
"Standard Test
Method for Surface Burning Characteristics of Building Materials." The ASTM E-
84 test
is used to assess spread of a flame on a surface of the material, typically, a
building
material. The ASTM E-84 test exposes the material, i.e., an article such as
polyurethane
(PUR) or polyisocyanurate (PIR) foam, to a controlled air flow and a flaming
fire
exposure, adjusted so as to spread the flame along an entire length of the
foam.
Typically, the test is performed on core foam of chosen thickness but on
occasion it is
performed on faced products, such as foil laminated board stock. A flame
spread index
and a smoke density are the two parameters measured in the ASTM E-84 test. The
flame
spread index takes into account both the rate and total distance of the
propagation of a
flame front, measured visually. The smoke density is a time-integrated
measurement of
the occlusion of a visible beam of light.
H&H File: 65,333-063 1
CA 02597955 2007-08-17
[0003] Performance of the foam is put into categories. Namely, a 0-25 flame
spread index is designated Class I, a 26-75 flame spread index is designated
Class II, and
a 76-225 flame spread index is designated Class III. A smoke density limit of
450 is
required in each of these classes. Another flammability test is FM 4880. In
order to meet
Class I flammability requirements, a convective flame parameter (FSPC) of the
FM 4880
test must be equal to or less than 0.39 s-- 1/2. The FSPc is determined from
the chemical
heat of combustion, effective heat of gasification, net heat flux, and thermal
response
parameter of the foam.
[0004] Since the foams may be used in building construction, the foams must
adhere to local building code requirements for flammability. When regulating
building
materials, many of the model building codes and insurance rating organizations
refer to
quality standards developed by standards-setting organizations such as the
ASTM.
Generally, the codes require that the foams have a flame spread index of 75 or
less and a
smoke density of 450 or less, i.e., meet Class II rating in accordance with
the ASTM E-84
test.
[0005] Foams used in laminated board stocks for building insulation
applications
have typically exceeded this requirement and have historically been rated as
Class I in the
ASTM E-84 test. Foams and methods for forming laminated board stock including
the
foams are disclosed, for example, in US Patent Numbers 5,385,952 to Fishback
et al. (the
`952 patent), 6,319,962 to Singh et al. (the `962 patent), and 6,372,811 to
Singh et al. (the
`811 patent). However, the foams of the above patents rely on a high
isocyanate index in
order to meet Class I flammability requirements. The above patents disclose
broad
ranges of an isocyanate index; however, example sections of the above patents
only teach
2
CA 02597955 2007-08-17
higher isocyanate indexes, i.e., isocyanate indexes of 200 or more, and do not
specifically
teach with respect to lower isocyanate indexes, i.e., isocyanate indexes below
200. For
example, the isocyanate index of the foams in an example section of the `952
patent are
at lowest 200 and reach upwards of 350. At this range of isocyanate index, the
foams of
the `952 patent are PIR foams rather than PUR foams. As is known in the art,
PIR foams
intrinsically have an improved flammability .performance and reduced smoke
density, but
tend to be friable and thus have poor adhesion when compared to PUR foams. The
foams
of the `962 patent also suffer from many of the weaknesses of the foams of the
`952
patent, namely higher isocyanate indexes in an example section of the `962
patent,
ranging of from 275 to 325, which are again PIR foams. The `811 patent also
fails to
specifically teach lower isocyanate indexes in an example section, as like the
`952 and
`962 patents. The foams of the `811 patent also rely heavily on a physical
blowing agent
in order to meet Class I flammability requirements, as is shown in the example
section of
the `811 patent. In addition, as also shown in the example section, gel times
for the
foams of the `811 patent are very low, at around 20 seconds. The foams of the
above
patents are useful for making laminated board stocks, such as continuously
laminated
board stocks, as shown and described in the patents, however, all of the foams
tend to gel
too quickly, and are generally not useful for large scale molding operations,
such as those
employed during production of long and/or thick insulation, wall, and ceiling
panels.
[0006] Due to the fast gel times, the foams of the above patents will cure
prior to
fully rising, filling and expanding within a large mold or similar reaction
vessel. In
addition, the foams of the above patents rely heavily on physical blowing
agents and a
phosphorous containing flame retardant in order to meet Class I flammability
3
CA 02597955 2010-11-05
requirements. As such, the foams of the above patents are limited in their
formulation, as
they require minimum amounts of the physical blowing agent and the flame
retardant in
order to meet Class I flammability requirements. In addition, the above
patents do not
specifically teach or disclose use of brominated polyols in order to exceed
Class I
flammability requirements.
[00071 Accordingly, there remains an opportunity to further improve physical
and
flammability properties of foams, in addition to increasing flexibility in
both formulation
and manufacturing requirements of foams over those previously achieved.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0008] The present invention provides a urethane system and an article
formed therefrom.
More specifically, the invention as claimed is directed to a urethane
system, said system comprising:
an isocyanate; and
a resin composition comprising
a halogenated polyol,
a brominated polyol different from said halogenated polyol,
a sucrose/glycerine polyol different from both of said halogenated
polyol and said brominated polyol, and
a flame retardant.
The invention as claimed is also directed to an article comprising the
reaction product of a urethane system, said system comprising:
an isocyanate; and
a resin composition comprising
4
CA 02597955 2010-11-05
a halogenated polyol,
a brominated polyol different from said halogenated polyol, and
a sucrose/glycerine polyol different from both of said halogenated
polyol and said brominated polyol,
with a flame retardant and a blowing agent.
[0009] Due to the presence of the halogenated polyol, the brominated polyol,
and
the flame retardant, the article exceeds Class I flanunability requirements by
not
surpassing a maximum flame spread index, smoke density, and convective flame
spread
parameter of ASTM E-84 and FM 4880 flammability tests, respectively. In
addition, the
article exhibits excellent dimensional stability and adhesion strength not
previously
attainable with previous articles that met Class I flammability requirements.
The article
also has increased flexibility in both formulation and manufacturing
requirements. For
example, the article of the present invention may have broad ranges of
components
4a
CA 02597955 2007-08-17
allowing for less stringent manufacturing requirements, and may be used to
form a wide
variety of different products.
DETAILED DESCRIPTION OF THE INVENTION
[0010] A resin composition is provided for use in forming an article. The
resin
composition comprises a halogenated polyol, a brominated polyol different from
the
halogenated polyol, and a flame retardant. The article comprises the reaction
product of
an isocyanate, the halogenated polyol, and the brominated polyol, in the
presence of the
flame retardant and a blowing agent. Typically, the article is further defined
as a
polyurethane (PUR) foam, which will be discussed in further detail below. The
article
may be used to form building materials such as, but not limited to,
insulation, wall, and
ceiling panels.
[0011] The resin composition includes the brominated polyol. The brominated
polyol may be any suitable brominated polyol as is known in the art. For
example, the
brominated polyol may fall into the class of polyester polyols, a polyether
polyols, and
combinations thereof. As another example, the brominated polyol may be an
aliphatic
polyol, a cycloaliphatic polyol, an aromatic polyol, a heterocyclic polyol,
and
combinations thereof. In one embodiment, the brominated polyol is selected
from the
group of brominated diols, brominated triols, and combinations thereof. It is
to be
appreciated that the term "brominated" means comprising one or more bromine
atoms.
The brominated polyol may comprise other halogen atoms in addition to bromine
atoms.
In one embodiment, the brominated polyol is tetrabrominated, i.e., comprises
four
bromine atoms. However, it is to be appreciated that the brominated polyol may
5
CA 02597955 2007-08-17
comprise more or less than four bromine atoms. One specific example of a
suitable
brominated polyol is a tetrabromophalate diol, commercially available from
Great Lakes
Chemical Corporation of West Lafayette, IN under the trade name PIT4-DiolTM
Another specific example of a suitable brominated polyol is Firemaster 520,
which is
also commercially available from Great Lakes Chemical Corporation.
[0012] Typically, the brominated polyol has a nominal functionality of from 2
to
3, more preferably of from 2 to 2.5, and most preferably of about 2.
Typically, the
brominated polyol has an OH value of from 100 to 800, more preferably of from
200 to
700, and most preferably of from 300 to 600 mg KOH/g. Without being bound or
limited
by any particular theory, it is believed that increasing the number of bromine
atoms of the
brominated polyol allows the article to have excellent flammability resistance
and test
results. For example, the brominated polyol may have a bromine atom content of
about
46 percent by weight of the brominated polyol. In addition, the brominated
polyol seems
to benefit the article, specifically with regard to flammability properties of
the article,
when in the presence of the halogenated polyol and the flame retardant.
[0013] Typically, the brominated polyol is included in an amount of from 5 to
35,
more preferably of from 5 to 25, and most preferably of from 5 to 15 percent
by weight
of the resin composition. It is to be appreciated that the amounts shown above
are based
on the percent by weight of the resin composition only as a reference point,
and should
not be construed as limiting the brominated polyol to only within the resin
composition.
For example, the brominated polyol may be included with the resin composition,
added
during the formation of the article, or combinations thereof.
6
CA 02597955 2007-08-17
[0014] The resin composition further includes the halogenated polyol. The
halogenated polyol may be any suitable halogenated polyol as is known in the
art. For
example, the halogenated polyol may comprise a polyester polyol, a polyether
polyol, or
combinations thereof. As another example, the halogenated polyol may comprise
an
aliphatic polyol, a cycloaliphatic polyol, an aromatic polyol, a heterocyclic
polyol, or
combination thereof. In one embodiment, the halogenated polyol may be based on
dimethyl terephthalate (DMT). In another embodiment, the halogenated polyol
comprises an aromatic polyester polyol. One specific example of a suitable
halogenated
polyol is an aromatic polyester polyol, commercially available from Oxid,
Incorporated
of Houston, TX under the trade name Terol 925.
[0015] Typically, the halogenated polyol has a nominal functionality of less
than
3, more preferably of from 2 to 2.5, and most preferably of about 2.5.
Typically, the
halogenated polyol has an OH value of from 100 to 800, most preferably of from
250 to
350. It is to be appreciated that the term "halogenated" means comprising one
or more of
a substituent comprising a halogen atom. When the halogenated polyol includes
one or
more of the substituents, the substituents may all be the same or may be
different from
one another. The substituent may be any halogen atom, such as a fluorine atom,
a
chlorine atom, a bromine atom, an iodine atom, or an astatine atom. Typically,
the
halogenated polyol comprises one or more substituents selected from the group
of a
chlorine atom, a bromine atom, and combinations thereof. Without being bound
or
limited by any particular theory, it is believed that increasing the number of
the
substituents of the halogenated polyol allows the article to have excellent
flammability
resistance and test results. In addition, the halogenated polyol seems to
benefit the
7
CA 02597955 2007-08-17
article, specifically with regard to flammability properties of the article,
when in the
presence of the brominated polyol and the flame retardant.
[0016] Typically, the halogenated polyol is included in an amount of from 20
to
85, more preferably of from 35 to 70, and most preferably of from 35 to 45
percent by
weight of the resin composition. It is to be appreciated that the amounts
shown above are
based on the percent by weight of the resin composition only as a reference
point, and
should not be construed as limiting the halogenated polyol to only within the
resin
composition. For example, the halogenated polyol may be included with the
resin
composition, added during the formation of the article, or combinations
thereof.
[0017] The resin composition may further comprise a supplemental polyol
different from the halogenated and brominated polyols. The supplemental polyol
may be
any suitable polyol as is known in the art. For example, the supplemental
polyol may
comprise a polyester polyol, a polyether polyol, or combinations thereof. As
another
example, the supplemental polyol may comprise an aliphatic polyol, a
cycloaliphatic
polyol, an aromatic polyol, a heterocyclic polyol, or combinations thereof. As
yet
another example, the supplemental polyol may comprise a sucrose polyol, a
sucrose/glycerine polyol, a trimethylolpropane polyol, or combinations
thereof.
[0018] The supplemental polyol may have a nominal functionality of from 2-8.
Typically, the supplemental polyol has a nominal functionality of from 4 to 6.
A higher
nominal functionality, i.e., 4 or more, may be useful for increasing a
crosslink density of
the article and therefore provide excellent dimensional stability for the
article. In
addition, the supplemental polyol may also be useful for decreasing demolding
time of
8
CA 02597955 2007-08-17
the article. Typically, the supplemental polyol has an OH value of from 100 to
800, more
preferably of from 200 to 600, and most preferably of from 360 to 570 mg
KOH/g.
[0019] In one embodiment, the supplemental polyol comprises a first polyol and
a
second polyol, which is especially useful when two different polyols are
required such as,
but not limited to, two polyols with different nominal functionalities. For
example, the
first polyol may have a nominal functionality of about 4. A specific example
of a
suitable first polyol is a sucrose/glycerine polyol, commercially available
from BASF
Corporation of Wyandotte, MI under the trade name Pluracol PEP 450. As
another
example, the second polyol may have a nominal functionality of about 5.5. A
specific
example of a suitable second polyol is a polyether tetrol, which is also
commercially
available from BASF Corporation, under the trade name Pluracol SG-470. In one
embodiment, the supplemental polyol is a polyether polyol, which is useful for
lowering
a viscosity of the resin composition and thereby promotes increased
flowability of the
resin composition.
[0020] Typically, the supplemental polyol is included in an amount of from 2
to
percent by weight of the resin composition. When the supplemental polyol
comprises
the first and second polyols, typically, the first polyol is included in an
amount of from 2
to 10, more preferably of from 3 to 5, and most preferably of from 3.5 to 4.5
percent by
weight of the resin composition. In addition, typically, the second polyol is
included in
20 an amount of from 10 to 30, more preferably of from 12.5 to 20, and most
preferably of
from 14.5 to 20 percent by weight of the resin composition. It is to be
appreciated that
the amounts shown above are based on the percent by weight of the resin
composition
only as a reference point, and should not be construed as limiting the
supplemental polyol
9
CA 02597955 2007-08-17
or, the first or second polyols, to only within the resin composition. For
example, the
supplemental polyol may be included with the resin composition, added during
the
formation of the article, or combinations thereof.
[0021] The resin composition further includes the flame retardant. The flame
retardant may be any suitable flame retardant as is known in the art.
Typically, the flame
retardant comprises one or more phosphorus atoms and may be selected from the
group
of phosphates, phosphites, phosphonates, polyphosphates, polyphosphites,
ammonium
polyphosphates, and combinations thereof. Without being bound or limited by
any
particular theory, it is believed that the flame retardant, when comprising
phosphorous
atoms, seems to benefit the article, specifically with regard to flammability
resistance and
test results of the article, when in the presence of the brominated polyol and
the
halogenated polyol.
[0022] Typically, the flame retardant is included in an amount of from 5 to
35,
more preferably of from 5 to 25, and most preferably of from 5 to 15 percent
by weight
of the resin composition. It is to be appreciated that the amounts shown above
are based
on the percent by weight of the resin composition only as a reference point,
and should
not be construed as limiting the flame retardant to only within the resin
composition. For
example, the flame retardant may be included with the resin composition,
included with
the isocyanate, added during the formation of the article, or combinations
thereof.
[0023] Suitable phosphates may be of the following formula:
O
RI -0 III O -R2
OI R3
CA 02597955 2007-08-17
where R1 to R3 signifies alkyl, halogen substituted alkyl, aryl, halogen
substituted aryl
and cycloalkyl groups. Preferred phosphates are those where R' to R3 signifies
C1-C12
alkyl, C1-C12 halogen substituted alkyl, phenyl, cresyl, halogen substituted
phenyl and C5-
Clo cycloalkyl groups. More preferred phosphates are those where R' to R3
signifies C1-
C8 alkyl, C1-C8 halogen substituted alkyl, and phenyl groups. Most preferred
phosphates
are those where R1 to R3 signifies C1-C4 alkyl, C1-C4 halogen substituted
alkyl, and
phenyl groups. Some examples of suitable phosphates are tributyl phosphate,
tris(2-
chloroethyl) phosphate (TCEP), commercially available from Aceto Corporation
of Lake
Success, NY, tris(1,3-dichloro-2-propyl)phosphate (TCPP), which is also
commercially
available from Aceto Corporation, tris(2-chloropropyl) phosphate, commercially
available from Albemarle Corporation of Baton Rouge, LA under the trade name
AB80,
tris(2-chloroisopropyl) phosphate, which is commercially available from Akzo
Nobel
Functional Chemicals LLC of Dobbs Ferry, NY under the trade name Fyrol PCF,
tetrakis(2-chloroethyl)ethylene diphosphate, t-butylphenyl diphenylphosphate,
which is
also commercially available from Akzo Nobel Functional Chemicals LLC under the
trade
name Phosflex 71B, triethyl phosphate (TEP), which is commercially available
from
Eastman Chemical Company, tributyl phosphate, commercially available from Akzo
Nobel under the trade name Phosflex 4, chloropropyl bis(bromopropyl)
phosphate,
commercially available from Great Lakes Corporation under the trade name
Firemaster
FM836, and Firemaster 550 and Firemaster BZ-54, both of which are also
commercially available from Great Lakes Corporation.
[0024] Suitable phosphites may be of the following formula:
11
CA 02597955 2007-08-17
R' O P O R2
OR3
where R' to R3 signifies H, alkyl, halogen substituted alkyl, aryl, halogen
substituted aryl
and cycloalkyl groups. Preferred phosphites are those where R' to R3 signifies
C1-C12
alkyl, C1-C12 halogen substituted alkyl, phenyl, cresyl, halogen substituted
phenyl and C5-
Clo cycloalkyl groups. More preferred phosphites are those where R' to R3
signifies, C1-
C8 alkyl, C1-C8 halogen substituted alkyl, and phenyl groups. Most preferred
phosphites
are those where R' to R3 signifies C1-C4, alkyl, C1-C4, halogen substituted
alkyl, and
phenyl groups. Some examples of suitable phosphates are triethyl phosphite
(TEP),
tris(2-chloroethyl)-phosphite, and triphenyl phosphite (TPP).
[00251 Suitable phosphonates may be of the following formula:
O
R1 O II O R2
R3
where R' to R3 signifies alkyl, halogen substituted alkyl, aryl, halogen
substituted aryl
and cycloalkyl groups. Preferred phosphonates are those where R' to R3
signifies C1-C12
alkyl, C1-C12 halogen substituted alkyl, phenyl, cresyl, halogen substituted
phenyl and C5-
Clo cycloalkyl groups. More preferred phosphonates are those where R' to R3
signifies
C1-C8 alkyl, C1-C8 halogen substituted alkyl, and phenyl groups. Most
preferred
phosphonates are those where R' to R3 signifies C1-C4 alkyl, C1-C4 halogen
substituted
alkyl, and phenyl groups. Some examples of suitable phosphonates are diethyl
ethyl
phosphonate, dimethyl methyl phosphanate, dimethyl methane phosphonate,
diethyl
diethanoaminomethylphosphonate, bis(2-chloroethyl), and 2-chloroethyl
phosphonate.
12
CA 02597955 2007-08-17
An example of a suitable ammonium polyphosphate [(NH4PO3),,; n = about 1000]
is
Hostaflam AP 422, commercially available from Hoechst AG of Frankfurt,
Germany.
[0026] The flame retardant may have one or more isocyanate-reactive hydrogen
atoms comprising a hydroxyl group, amino group, thio group, and combinations
thereof.
Suitable compounds may include monomeric or oligomeric phosphates, phosphites,
phosphonates polyols, and combinations thereof.
[0027] Suitable isocyanate-reactive phosphates may be prepared by (1) a
reaction
of polyalkylene oxides with phosphoric acids and partial esters of phosphoric
acids, (2) a
reaction of aliphatic alcohols with phosphoric acids and partial esters of
phosphoric acids,
and (3) by transesterification of products of (1) and (2). Examples of
suitable isocyanate-
reactive phosphates include tributoxyethyl phosphates, oligomeric
organophosphate
diols, ethoxylated phosphate esters, mono- and diesters of phosphoric acid and
alcohols,
and combinations thereof.
[0028] Suitable isocyanate-reactive phosphites may be prepared by (1) a
reaction
of polyalkylene oxides with phosphorous acids and partial esters of
phosphorous acids,
(2) a reaction of aliphatic alcohols with phosphorous acids and partial esters
of
phosphorous acids, and (3) by transesterification of products of (1) and (2).
[0029] Suitable isocyanate-reactive phosphonates may be prepared (1) by a
reaction of polyalkylene oxides with phosphonic acids, (2) by a reaction of
phosphite
polyols with alkyl halides, (3) by a condensation of dialkyl phosphonates,
diethanolamine
and formaldehyde, (4) by transesterification of products of (1) (2) and (3),
and (5) by
reaction of dialkyl alkyl phosphonate with phosphorous pentaoxide and alkylene
oxide.
Some examples of suitable isocyanate-reactive phosphonates include diethyl N,N-
bis(2-
13
CA 02597955 2007-08-17
hydroxyethyl) aminoethyl phosphonate, hydroxyl containing oligomeric
phosphonate.
Other examples of suitable flame retardants include red phosphorous, hydrated
aluminum
oxide, calcium sulfate, expanded graphite, cyanuric acid derivatives, and
combinations
thereof.
[0030] The isocyanate may be any suitable isocyanate as is known in the art.
Examples of suitable isocyanates for forming the article include organic
polyisocyanates,
which may have two or more isocyanate functionalities, and include
conventional
aliphatic, cycloaliphatic, araliphatic and aromatic isocyanates. Specific
examples of
suitable isocyanates include: alkylene diisocyanates with 4 to 12 carbons in
the alkylene
radical such as 1,12-dodecane diisocyanate, 2-ethyl-1,4-tetramethylene
diisocyanate, 2-
methyl-1,5-pentamethylene diisocyanate, 1,4-tetramethylene diisocyanate and
preferably
1,6-hexamethylene diisocyanate; cycloaliphatic diisocyanates such as 1,3- and
1,4-
cyclohexane diisocyanate as well as any mixtures of these isomers, 1-
isocyanato-3,3,5-
trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate), 2,4- and
2,6-
hexahydrotoluene diisocyanate as well as the corresponding isomeric mixtures,
4,4'- 2,2'-,
and 2,4'-dicyclohexylmethane diisocyanate as well as the corresponding
isomeric
mixtures, and aromatic diisocyanates and polyisocyanates such as 2,4- and 2,6-
toluene
diisocyanate and the corresponding isomeric mixtures, 4,4'-, 2,4'-, and 2,2'-
diphenylmethane diisocyanate and the corresponding isomeric mixtures, mixtures
of 4,4'-
, 2,4'-, and 2,2-diphenylmethane diisocyanates and polyphenylenepolymethylene
polyisocyanates (crude MDI), as well as mixtures of crude MDI and toluene
diisocyanates. Other examples of suitable isocyanates include Lupranate M70L,
14
CA 02597955 2007-08-17
Lupranate M70R, and Lupranate M20S, and combinations thereof, which are all
commercially available from BASF Corporation.
[0031] Frequently, the isocyanate may include modified multivalent
isocyanates,
i.e., products obtained by the partial chemical reaction of organic
diisocyanates and/or
polyisocyanates. Examples of suitable modified multivalent isocyanates include
diisocyanates and/or polyisocyanates containing ester groups, urea groups,
biuret groups,
allophanate groups, carbodiimide groups, isocyanurate groups, and/or urethane
groups.
Specific examples of suitable modified multivalent isocyanates include organic
polyisocyanates containing urethane groups and having an NCO content of 15 to
33.6
parts by weight based on the total weight, e.g., with low molecular weight
diols, triols,
dialkylene glycols, trialkylene glycols, or polyoxyalkylene glycols with a
molecular
weight of up to 6000; modified 4,4'-diphenylmethane diisocyanate or 2,4- and
2,6-
toluene diisocyanate, where examples of di- and polyoxyalkylene glycols that
may be
used individually or as mixtures include diethylene glycol, dipropylene
glycol,
polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene glycol,
polyoxypropylene glycol, and polyoxypropylene polyoxyethylene glycols or -
triols.
Prepolymers containing NCO groups with an NCO content of from 3.5 to 29 parts
by
weight based on the total weight of the isocyanate and produced from the
polyester
polyols and/or polyether polyols described below; 4,4'-diphenylmethane
diisocyanate,
mixtures of 2,4'- and 4,4'-diphenylmethane diisocyanate, 2,4,- and/or 2,6-
toluene
diisocyanates or polymeric MDI are also suitable. Furthermore, liquid
polyisocyanates
containing carbodiimide groups having an NCO content of from 15 to 33.6 parts
by
weight based on the total weight of the isocyanate, may also be suitable,
e.g., based on
CA 02597955 2007-08-17
4,4'- and 2,4'- and/or 2,2'-diphenylmethane diisocyanate and/or 2,4'- and/or
2,6-toluene
diisocyanate. The modified polyisocyanates may optionally be mixed together or
mixed
with unmodified organic polyisocyanates such as 2,4'- and 4,4'-diphenylmethane
diisocyanate, polymeric MDI, 2,4'- and/or 2,6-toluene diisocyanate.
[0032] The isocyanate used in the subject invention may have a nominal
functionality of at least 2. Typically, the isocyanate has a nominal
functionality of at
least 2.7. A higher nominal functionality, e.g., 2.7, provides for a greater
cross-linking
density in the article compared to a lower nominal functionality, e.g., 2,
which improves
the dimensional stability of the article.
[0033] The isocyanate, the halogenated polyol, the brominated polyol, and
optionally, one of the supplemental polyols different from the halogenated and
brominated polyols, may be reacted at any isocyanate index. Typically, the
isocyanate
index is of from 90 to 150, more preferably of from 100 to 120, and most
preferably of
from 105 to 115. In one embodiment, the isocyanate and the resin composition
may be
over indexed, i.e., a stoichiometric excess of the isocyanate to all
isocyanate-reactive
components, i.e., the halogenated and brominated polyols, and optionally, one
or more of
the supplemental polyols different from the halogenated and brominated
polyols, in the
resin composition may be provided in order to maximize dimensional stability
of the
article. More specifically, the isocyanate and the resin composition may be
reacted at an
isocyanate index of at least 105. For example, the isocyanate index may fall
within a
range of from 105 to 130 to yield excellent dimensional stability within the
article. The
dimensional stability prevents the article from pulling away from a substrate,
such as
metal, and also prevents the article from losing insulating properties.
Typically, a PUR
16
CA 02597955 2007-08-17
foam is made with isocyanate indexes in the range of from 90 to 150, and a
polyisocyanurate (PIR) foam is made with isocyanate indexes in the range of
from 200 to
350. However, PIR foams tend to be friable and thus have poor adhesion for
attachment
to a substrate and thus are not suitable for purposes of the present
invention.
[0034] When over indexing is employed, the article may be formed in the
presence of a trimerization catalyst. The trimerization catalyst may be any
suitable
trimerization catalyst as is known in the art. Typically, the trimerization
catalyst is
included in an amount of from 0.1 to 1.0, more preferably of from 0.2 to 0.8,
and most
preferably of from 0.3 to 0.5 percent by weight of the resin composition. It
is to be
appreciated that the amounts shown above are based on the percent by weight of
the resin
composition only as a reference point, and should not be construed as limiting
the
trimerization catalyst to only within the resin composition. For example, the
trimerization catalyst may be included with the resin composition, included
with the
isocyanate, added during the formation of the article, or combinations
thereof. Some
examples of suitable trimerization catalysts include N,N,N-
dimethylaminopropylhexahydrotriazine, potassium, potassium acetate, N,N,N-
trimethyl
isopropyl amine/formate, and combinations thereof. One specific example of a
suitable
trimerization catalyst is Polycat 41, commercially available from Air
Products and
Chemicals of Allentown, PA. The trimerization catalyst may be used to aid in
curing
excess isocyanate after the isocyanate, the halogenated and brominated
polyols, and
optionally, one or more of the supplemental polyols different from the
halogenated and
brominated polyols, react. Curing of excess isocyanate may result in excellent
17
CA 02597955 2007-08-17
dimensional stability of the article. In addition, the trimerization catalyst
may also be
used to aid in the article further exceeding flammability requirements.
[0035] The article may be formed in the presence of a tertiary amine catalyst.
The tertiary amine catalyst may be any suitable tertiary amine catalyst as is
known in the
art. Typically, the tertiary amine catalyst is included in an amount of from
0.1 to 1.0,
more preferably of from 0.3 to 0.8, and most preferably of from 0.5 to 0.7
percent by
weight of the resin composition. It is to be appreciated that the amounts
shown above are
based on the percent by weight of the resin composition only as a reference
point, and
should not be construed as limiting the tertiary amine catalyst to only within
the resin
composition. For example, the tertiary amine catalyst may be included with the
resin
composition, included with the isocyanate, added during the formation of the
article, or
combinations thereof. Some examples of suitable tertiary amine catalysts
include
dimethylaminoethanol, dimethylaminoethoxyethanol, triethylamine, N,N,N',N'-
tetramethylethylenediamine, N,N-dimethylaminopropylamine, N,N,N',N',N"-
pentamethyldipropylenetriamine, tris(dimethylaminopropyl)amine, N,N-
dimethylpiperazine, tetramethylimino-bis(propylamine), dimethylbenzylamine,
trimethylamine, triethanolamine, N,N-diethyl ethanolamine, N-
methylpyrrolidone, N-
methylmorpholine, N-ethylmorpholine, bis(2-dimethylamino-ethyl)ether, N,N-
dimethylcyclohexylamine (DMCHA), N,N,N',N',N"-pentamethyldiethylenetriamine,
1,2-
dimethylimidazole, 3-(dimethylamino) propylimidazole, and combinations
thereof.
Some specific examples of suitable tertiary amine catalysts are Polycat 18
and Polycat
1058, which are both commercially available from Air Products and Chemicals.
The
18
CA 02597955 2007-08-17
tertiary amine catalyst may be used to aid in demolding, i.e., removing, the
article from a
mold or other reaction vessel if employed during formation of the article.
[0036] The article may be formed in the presence of an amine blowing catalyst.
The amine blowing catalyst may be any suitable amine blowing catalyst as is
known in
the art. Typically, the amine blowing catalyst is included in an amount of
from 0.1 to
1.0, more preferably of from 0.3 to 0.8, and most preferably of from 0.5 to
0.7 percent by
weight of the resin composition. It is to be appreciated that the amounts
shown above are
based on the percent by weight of the resin composition only as a reference
point, and
should not be construed as limiting the amine blowing catalyst to only within
the resin
composition. For example, the amine blowing catalyst may be included with the
resin
composition, included with the isocyanate, added during the formation of the
article, or
combinations thereof. A specific example of a suitable amine blowing catalyst
is N,N-
dimorpholinodiethyl ether, commercially available from Chevron Products
Company of
San Ramon, CA under the trade name Texacat DMDEE. The amine blowing catalyst
may be used to increase the rate of reaction between the isocyanate, the
halogenated and
brominated polyols, and optionally, one or more of the supplemental polyols
different
from the brominated and halogenated polyols during formation of the article.
[0037] The resin composition may further include the blowing agent. The
blowing agent may be any suitable blowing agent as is known in the art. In one
embodiment, the blowing agent may be selected from the group of chemical
blowing
agents, physical blowing agents, and combination thereof. For example, the
blowing
agent may be selected from the group of hydrofluorocarbons, hydrocarbons,
chlorofluorocarbons, hydrochloroflourocarbons, water, and combinations
thereof.
19
CA 02597955 2007-08-17
[0038] The resin composition may further include a co-blowing agent in
addition
to the blowing agent. Typically, the blowing agent is a physical blowing agent
such as,
but not limited to, a hydrofluorocarbon, and the co-blowing agent is a
chemical blowing
agent such as, but not limited to, water. As used herein, the physical blowing
agents are
the blowing agents that retain their original chemical structure throughout a
blowing
process. Specific examples of the physical blowing agents that are suitable
for the
present invention include HFC-134a, HFC-152a, HFC-245fa, HFC-365mfc, HFC-22,
and
combinations thereof, as well as iso-butane, iso-pentane, cyclopentane, n-
pentane, and
combinations thereof. Typically, the physical blowing agent is selected from
the group
of hydrofluorocarbons, hydrocarbons, and combinations thereof, due to zero
ozone
depletion potential. In one embodiment, the physical blowing agent comprises
HFC-
245fa. As known to those skilled in the art, the chemical blowing agent, e.g.,
water,
reacts with the isocyanate, thereby generating carbon dioxide during the
formation of the
article which actually carries out the blowing process.
[0039] Typically, the blowing agent, i.e., the chemical blowing agent is
included
in an amount of from 10 to 25, more preferably of from 10 to 20, and most
preferably of
from 10 to 15 percent by weight of the resin composition. When included,
typically, the
co-blowing agent, i.e., water is included in an amount of from 1.0 to 5.0,
more preferably
included of from 2.0 to 4.0, and most preferably of from 2.0 to 3.0 percent by
weight of
the resin composition. It is to be appreciated that the amounts shown above
are based on
the percent by weight of the resin composition only as a reference point, and
should not
be construed as limiting the blowing agent or the co-blowing agent to only
within the
resin composition. For example, the blowing agent may be included with the
resin
CA 02597955 2007-08-17
composition, included with the isocyanate, added during the formation of the
article, or
combinations thereof.
[0040] The resin composition may further include an adhesion promoter. The
adhesion promoter may be any suitable adhesion promoter as is known in the
art. In one
embodiment, the adhesion promoter comprises propylene carbonate, which
promotes
excellent adhesion strength for the article, especially at lower molding
temperatures, for
example, at 90 F. A specific example of a suitable adhesion promoter is
Jeffsol
Propylene Carbonate, commercially available from Huntsman Corporation if Salt
Lake
City, UT. Other examples of suitable adhesion promoters include castor oil,
polyethylenimine, polyester polyols derived from polycarboxilic acids, and
combinations
thereof.
[0041] Typically, the adhesion promoter is included in an amount of from 1.0
to
10, more preferably of from 2.0 to 8.0, and most preferably of from 4.0 to 6.0
percent by
weight of the resin composition. It is to be appreciated that the amounts
shown above are
based on the percent by weight of the resin composition only as a reference
point, and
should not be construed as limiting the adhesion promoter to only within the
resin
composition. For example, the adhesion promoter may be included with the resin
composition, included with the isocyanate, added during the formation of the
article, or
combinations thereof. Without being bound or limited by any particular theory,
it is
believed that the adhesion promoter imparts surface instability to the article
and causes
cells on a surface of the article to collapse. When the article is adjacent to
a substrate,
such as metal, the collapse of the cells results in excellent bonding between
the article
21
CA 02597955 2007-08-17
and the substrate. As a result, the article and the substrate exhibit
excellent adhesion
strength between one another.
[0042] The resin composition may further include a surfactant. The surfactant
may be any suitable surfactant as is known in the art. For example, the
surfactant may be
an inorganic surfactant, an organic surfactant, and combinations thereof. As
another
example, the surfactant may also be a non-ionic surfactant, a cationic
surfactant, an
anionic surfactant, an amphoteric surfactant, and combinations thereof. As yet
another
example, the surfactant may be a polyoxyalkylene polyol, an alkylphenol
ehtoxylate, and
combinations thereof. A specific example of a suitable surfactant is a
silicone surfactant,
commercially available from Goldschmidt Chemical Corporation of Hopewell, VA
under
the trade name of TEGOSTAB B 8408.
[0043] Typically, the surfactant is included in an amount of from 0.1 to 3,
more
preferably of from 1 to 2.5, and most preferably included of from 1.5 to 2.5
percent by
weight of the resin composition. It is to be appreciated that the amounts
shown above are
based on the percent by weight of the resin composition only as a reference
point, and
should not be construed as limiting the surfactant to only within the resin
composition.
For example, the surfactant may be included with the resin composition,
included with
the isocyanate, added during the formation of the article, or combinations
thereof.
[0044] The resin composition may further include an additive. The additive may
be selected from the group of plasticizers, cross-linking agents, chain-
extending agents,
chain-terminating agents, air releasing agents, wetting agents, surface
modifiers, waxes,
foam stabilizing agents, viscosity reducers, infra-red opacifiers, cell-size
reducing
compounds, reinforcing agents, dyes, pigments, colorants, mold release agents,
anti-
22
CA 02597955 2007-08-17
oxidants, compatibility agents, ultraviolet light stabilizers, thixotropic
agents, anti-aging
agents, lubricants, coupling agents, solvents, rheology promoters, fillers,
combinations
thereof, and other additives as are known to those skilled in the art.
Typically, the
additive is included in an amount of from 0.1 to 5 percent by weight of the
resin
composition. It is to be appreciated that the amounts shown above are based on
the
percent by weight of the resin composition. only as a reference point, and
should not be
construed as limiting the additive to only within the resin composition. For
example, the
additive may be included with the resin composition, included with the
isocyanate, added
during the formation of the article, or combinations thereof.
[0045] As previously discussed, typically, the article is further defined as a
PUR
foam. For example, the article may be a rigid PUR foam. The article may be
used in a
wide variety of applications. Typically, the article is used to form building
materials such
as, but not limited to, insulation, wall and ceiling panels. The article may
be disposed
adjacent to, i.e., adhered to, a substrate, such as metal, plastic, wood,
paper, combinations
thereof, and other substrates as are known to those skilled in the art. The
article may be
formed by any method or means as in known to those skilled in the art. For
example, the
article may be formed in a reaction vessel such as, but not limited to, an
open- or closed-
type mold. As other examples, the article may be formed directly on the
substrate, or
adhered to the substrate after forming the article.
[0046] The article may have any density. Typically, the article has a density
of
from 1 to 5, more preferably of from 1 to 3, and most preferably of from 1.5
to 2.5
pounds per cubic foot. The article may be of any size and shape. For example,
the article
23
CA 02597955 2007-08-17
may have a thickness of from 1 to 12 inches. One skilled in the art will
select an
appropriate size and shape based on necessity, qualities, and desire.
[0047] Typically, the article has a gel time of from 25 to 200, more
preferably of
from 50 to 150, and most preferably of from 60 to 120 seconds. A longer gel
time range
allows the article to rise and expand, which is especially useful during
production. This
is especially useful for making insulation, wall, or ceiling panels in a mold,
a panel,- or
other reaction vessel. For example, having a longer gel time allows the
article to fully
rise and expand within the mold prior to curing. As such, the article may rise
to a height
or thickness of from 6 inches or more. In addition, if the mold is large in
size, the longer
gel time allows the article to fully expand within the mold. For example, the
mold may
be about 40 feet in length, and the article may be mixed and communicated into
the mold
at one end. The longer gel time allows the article to fully expand to an
opposite end of
the mold prior to curing. Conversely, other previous articles of the prior
art, which are
used primarily to make continuous laminate board stocks, tend to have very
fast gel
times, typically less than 25 seconds. However, due to the fast gel time, the
articles of
the prior art cannot rise or expand to sufficient heights or lengths for large
scale molding
processes and thus are not suitable for purposes of the present invention. In
addition, the
articles of the prior art tend to be very friable, as previously described
above, which
greatly reduces adhesion strength when the articles of the prior art are
bonded to the
substrate, and thus are not suitable for purposes of the present invention. It
is to be
appreciated that the article of the present invention is not limited to large
scale molding
processes. It should also be appreciated that the article of the present
invention is not
limited to use with the substrate. For example, the article may be used alone.
It should
24
CA 02597955 2007-08-17
be appreciated that the term "gel time" is defined as is generally known in
the art.
Typically, the gel time is defined as a total time between initially mixing
components for
forming the article and a time when long strings, i.e., tacky material, can be
pulled from
an interior of the article while forming. For example, to test the gel time of
the article, a
stop watch is started when components of the article are initially mixed and
after some
time has passed, i.e., the article is foaming, a spatula is pushed into and
then pulled from
the article to observe whether any of the article is withdrawn along with the
spatula. If
any of the article "strings" along with the spatula while pulling the spatula
away from the
article, the total time passed since initially mixing the components is
recorded as the gel
time.
[0048] The article of the present invention has a flame spread index of less
than
or equal to 25 and a smoke density of less than or equal to 450 according to
ASTM E-84
testing. The article also has a convective flame spread parameter (FSPc) of
less than or
equal to 0.39 s-112 according to FM 4880 testing. When the flame spread index,
the
smoke density, and the convective flame spread parameter are met, i.e., the
article is at or
below these numbers, the article is classified as Class I for meeting Class I
flammability
requirements. Typically, the article must meet this criterion in order to be
used to form
building materials. These tests and flammability requirements are well known
to those
skilled in the art. The article of the present invention exceeds Class I
flammability, as
further discussed and shown below.
[0049] When there is the substrate, the article exhibits excellent adhesion
strength
between the article and the substrate. The article and the substrate may be
exposed to
various temperatures such as, but not limited to, temperatures encountered
inside and/or
CA 02597955 2007-08-17
outside of a building or similar structure. The article and the substrate
remain adhered
after many heating and cooling thermo-cycles and do not exhibit blistering or
bubbling,
i.e., the substrate does not de-bond from the article or vice versa. The
article also exhibits
excellent adhesion strength when exposed to various humidity levels such as,
but not
limited to, humidity levels encountered in tropical, arid, and temperate
climates.
[0050] The article also has excellent dimensional stability. More
specifically,
dimensional stability is measured as a percent volume change of the article
over a period
of days at a given temperature and humidity. The article of the present
invention may
exhibit a percent volume change of less than 5 percent over a period of up to
28 days at a
temperature of up to 200 F and a relative humidity of 100%. For example, the
article
may exhibit a percent volume change of about 0 over a period of about 28 days
and a
temperature of about 200 F at 0% relative humidity, or a percent volume change
of about
-1 over a period of about 28 days and a temperature of about 158 F at 100%
relative
humidity.
[0051] The following examples, illustrating the articles of the present
invention,
are intended to illustrate and not to limit the invention.
EXAMPLES
[0052] The article of the present invention is made by combining a halogenated
polyol, a brominated polyol, a flame retardant, and a supplemental polyol
different from
the brominated and halogenated polyols, a catalyst, a blowing agent, a
surfactant, and
optionally, an adhesion promoter in a vessel to form a resin composition. The
resin
composition and an isocyanate are then mixed together in a reaction vessel
such as by
spraying and react to form an article. The article is observed for cream time,
gel time,
26
CA 02597955 2007-08-17
tack-free time, and other properties. The amount and type of each component
used to
form the article is indicated in Table 1 below with all values in percent by
weight based
on the total weight of the resin composition unless otherwise indicated.
TABLE 1
Component Article 1 Article 2 Article 3 Article 4
Resin Composition Polyol A 37.04 38.88 42.00 42.50
Polyol B 9.92 10.42 0.00 9.92
Flame Retardant 10.91 11.46 10.91 0.00
Polyol C 15.21 15.97 20.17 20.66
Polyol D 3.97 4.17 3.97 3.97
Catalyst A 0.40 0.42 0.40 0.40
Catalyst B 0.60 0.63 0.60 0.60
Catalyst C 0.65 0.69 0.65 0.65
Blowing Agent A 12.56 13.19 12.56 12.56
Blowing Agent B 2.38 2.50 2.38 2.38
Additive A 4.76 0 4.76 4.76
Additive B 1.60 1.67 1.60 1.60
Total 100.00 100.00 100.00 100.00
Isocyanate Ratio of Resin/Isocyanate 0.96 1.01 0.96 0.91
Isocyanate Index 110 110 110 110
Results Cream time, seconds 13 13 12 15
Gel time, seconds 87 87 85 89
Tack-free time, seconds 137 137 132 141
Cure Temperature, F 73 73 73 73
Density of article, lbs/ft3 2.1 2.1 2.1 2.1
E-84 Flame Spread Index 25 25 60 35
E-84 Smoke Density 400 400 250 600
FM 4880 FSPc, seconds-"' 0.36 0.36 0.48 0.45
* This numerical flame spread rating is not intended to reflect hazards
presented by this
or any other material under actual fire conditions.
[0053) Polyol A is a halogenated aromatic polyester polyol having a nominal
functionality of 2.4, and an OH value of from 300-325 mg KOH/g, commercially
available from Oxid, Incorporated of Houston, TX.
27
CA 02597955 2007-08-17
[0054] Polyol B is a tetrabromophthalate diol, commercially available from
Great
Lakes Chemical Corporation of West Lafayette, IN.
[0055] Flame Retardant is trichloropropyl phosphate (TCPP), commercially
available from Aceto Corp. of Lake Success, NY.
[0056] Polyol C is a sucrose/glycerine polyether polyol having a nominal
functionality of 5.5, and an OH value of from 460-780 mg KOH/g, commercially
available from BASF Corporation of Wyandotte, MI.
[0057] Polyol D is a polyether tetrol having an OH value of from 540-570 mg
KOH/g, commercially available from BASF Corporation of Wyandotte, MI.
[0058] Catalyst A is 1,3,5-tris(3-(dimethylamino)propyl) hexahydro-s-tri
azine,
commercially available from Air Products and Chemicals of Allentown, PA.
[0059] Catalyst B is a tertiary amine catalyst, commercially available from
Air
Products and Chemicals of Allentown, PA.
[0060] Catalyst C is N,N-dimorpholinodiethyl ether, commercially available
from
Chevron Products Company of San Ramon, CA.
[0061] Blowing agent A is HFA 245fa, commercially available from Honeywell
International Incorporated of Morristown, NJ.
[0062] Blowing agent B is water.
[0063] Additive A is propylene carbonate, commercially available from
Huntsman Corporation of Salt Lake City, UT.
[0064] Additive B is a polysiloxane-polyether copolymer surfactant,
commercially available from Goldschmidt Chemical Corporation of Hopewell, VI.
28
CA 02597955 2007-08-17
[0065] Isocyanate is a polymeric diphenylmethane diisocyanate (MDI) having an
actual functionality of about 3.0 and an NCO content of about 31.0%,
commercially
available from BASF Corporation of Wyandotte, MI.
[0066] In Table 1 above, Articles 1 and 2 are examples of the present
invention,
and Articles 3 and 4 are comparative examples. The articles are made by
combining the
resin composition and the isocyanate. More specifically, the resin composition
and the
isocyanate are sprayed into a mold by a mix head. The articles rise, expand,
and cure.
The cream, gel, and tack-free times are measured. The densities of the
articles are then
measured. The articles are then removed from the mold. The time it takes to
demold
Article 1 and Article 2 is lower than in previous articles, and lower than
Articles 3 and 4,
which in turn increases production efficiency. Article 1 had the shortest
demold time
relative to the other articles. The articles are then tested for dimensionally
stability.
Article 1 and Article 2 are both deemed as having excellent dimensionally
stability. The
articles are then tested to determine if the flammability requirements are
met. Article 1
and Article 2 have a flame spread index of 25 and a smoke density of 400
according to
ASTM E-84 testing. In addition, Article 1 and Article 2 have a convective
flame spread
parameter (FSPC) of 0.36s-"2 according to FM 4880 testing. These flammability
results
for Article 1 and Article 2 exceed the Class I flammability requirements.
Conversely,
comparative examples, Article 3 and Article 4, do not meet Class I
flammability
requirements. Both Article 3 and Article 4 exceed the FSPc upper limit of 0.39
seconds-
1i2. Article 3 and Article 4 also exceed the flame spread index upper limit of
25. Article
4 also exceeds the smoke density upper limit of 450.
29
CA 02597955 2007-08-17
[0067] Obviously, many modifications and variations of the present invention
are
possible in light of the above teachings. The invention may be practiced
otherwise than
as specifically described within the scope of the appended claims.
