U.S. patent application number 13/519546 was filed with the patent office on 2012-10-25 for inhibition of amine oxidation.
This patent application is currently assigned to Huntsman Petrochemical LLC. Invention is credited to Bhajendra Narayan Barman, Robert A. Grigsby, JR..
Application Number | 20120271026 13/519546 |
Document ID | / |
Family ID | 44305753 |
Filed Date | 2012-10-25 |
United States Patent
Application |
20120271026 |
Kind Code |
A1 |
Barman; Bhajendra Narayan ;
et al. |
October 25, 2012 |
INHIBITION OF AMINE OXIDATION
Abstract
In an embodiment, an amine-oxidation inhibitor, such as a free
radical scavenger and/or antioxidant, is added to an
oxidation-sensitive amine, such as an amine catalyst, to inhibit
oxidation of the amine. The inhibitor-treated amine may then be
used in an application such as a polyurethane application to reduce
the emission of undesired oxidation products from the
polyurethane.
Inventors: |
Barman; Bhajendra Narayan;
(Katy, TX) ; Grigsby, JR.; Robert A.; (Spring,
TX) |
Assignee: |
Huntsman Petrochemical LLC
|
Family ID: |
44305753 |
Appl. No.: |
13/519546 |
Filed: |
December 30, 2010 |
PCT Filed: |
December 30, 2010 |
PCT NO: |
PCT/US10/62476 |
371 Date: |
June 27, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61293388 |
Jan 8, 2010 |
|
|
|
Current U.S.
Class: |
528/49 ; 564/506;
564/508 |
Current CPC
Class: |
C08G 18/40 20130101;
C08G 2101/0008 20130101; C08G 18/7671 20130101; C08G 18/1825
20130101; C08G 18/14 20130101; C08K 5/005 20130101; C07C 213/10
20130101; C08G 18/1833 20130101; C08G 18/4841 20130101; C08G
2101/0083 20130101 |
Class at
Publication: |
528/49 ; 564/508;
564/506 |
International
Class: |
C07C 217/42 20060101
C07C217/42; C08G 18/06 20060101 C08G018/06; C07C 215/18 20060101
C07C215/18 |
Claims
1. A composition comprising: an oxidation-sensitive amine selected
from one or more of an amine catalyst, a polyetheramine, an
ethyleneamine, an alkoxylated amine, an alkoxylated amine, and a
surfactant amine; and an amine-oxidation inhibitor selected from a
free radical scavenger, an antioxidant, or both.
2. The composition of claim 1 wherein the oxidation-sensitive amine
is a tertiary amine catalyst selected from one or more of
bis-(2-dimethyaminoethyl)ether,
N,N,N'-trimethyl-N'-hydroxyethylbisaminoethylether, N-(3
-dimethylaminopropyl)-N,N-diisopropanolamine,
N,N-dimethylethanolamine, triethylene diamine,
N,N-dimethylchyclohexylamine, benzyldimethylamine,
pentamethyldiethylenetriamine,
N,N,N',N,'',N''-pentamethyldipropylenetriamine,
N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine, N-(3
-dimethylaminopropyl)-N,N-diisopropanolamine, N'-(3
-(dimethylamino)propyl-N,N-dimethyl-dimethyl-1, 3-propanediamine,
2-(2-dimethylaminoethoxy)ethanol,
N,N,N'-trimethylaminoethyl-ethanolamine, N-ethylmorpholine,
N-methylmorpholine, 4-methoxyethylmorpholine, N,
N'dimethylpiperazine, 2,2'dimorpholinodiethylether,
1,3,5-tris(3-(dimethylamino)propyl)-hexahydro-s-triazine, 1
-Propanamine, 3-(2-(dimethylamino)ethoxy).
3. The composition of claim 1 wherein the oxidation-sensitive amine
is a polyetheramine selected from one or more of a monoamine, a
diamine, a polyether diamine, an unhindered diamine, and a
triamine.
4. The composition of claim 1 wherein the oxidation-sensitive amine
is an ethyleneamine selected from one or more of ethylenediamine,
diethylenetriamine, triethylenetetramine, tetraethylenepentamine,
aminoethylpiperazine, aminoethylethanolamine,
pentaethylenehexamine, hexaethyleneheptamine, and mixtures
thereof.
5. The composition of claim 1 wherein the oxidation-sensitive amine
is an alkoxylated amine selected from one or more of
2-(2-aminoethoxy)ethanol, diethanolamine, N-methyldiethanolamine,
and triethanolamine.
6. The composition of claim 1 wherein the oxidation-sensitive amine
is a surfactant amine selected from one or more of a polyether
monoamine, a hydrophobic monoamine, and a hydrophilic polyether
monoamine.
7. The composition of claim 1 wherein the amine-oxidation inhibitor
is a free-radical scavenger selected from one or more of
allupurinol, propyl thiouracil, glutamine, diaminobenzylamine,
nicotinamide, methimazole, phenyl methimazole, and derivatives of
methimazole or phenyl methimazole.
8. The composition of claim 1 wherein the amine-oxidation inhibitor
is methimazole.
9. The composition of claim 1 wherein the amine-oxidation inhibitor
is an antioxidant selected from one or more of a hindered phenolic,
a hindered aliphatic amine, a hindered aromatic amine, a mixed
phenolic, an antioxidant with triazole and phenolic group, and a
natural antioxidant.
10. The composition of claim 1 wherein the amount of
amine-oxidation inhibitor in the composition is from 5 ppm to 5000
ppm.
11. The composition of claim 1 wherein the amount of
amine-oxidation inhibitor in the composition is 0.5% to 10% by
weight of the composition.
12. A method of forming an inhibitor-treated amine comprising:
combining an oxidation-sensitive amine selected from one or more of
an amine catalyst, a polyetheramine, an ethyleneamine, an
alkoxylated amine, and a surfactant amine with an amine-oxidation
inhibitor selected from an antioxidant, a free-radical scavenger,
or both to form the inhibitor-treated amine
13. The method of claim 12 further including storing the
inhibitor-treated amine in a container padded with an inert
gas.
14. The method of claim 12 wherein from 5 ppm to 5000 ppm of the
amine-oxidation inhibitor is combined with the oxidation-sensitive
amine
15. The method of claim 12 wherein the inhibitor-treated amine and
the amine-oxidation inhibitor are combined to form a blend such
that the concentration of amine-oxidation inhibitor in the blend is
from 0.5% to 10% by weight of the total blend.
16. The method of claim 12 further including incubating the
inhibitor-treated amine at a temperature of from 0.degree. C. to
150.degree. C.
17. The method of claim 12 further including adding the
inhibitor-treated amine to another oxidation-sensitive material
selected from one or more of an isocyanate, a polyol, a prepolymer,
a quasiprepolymer, and a blowing agent.
18. The method of claim 12 further including reducing the
production of amine-oxidation products in the inhibitor-treated
amine as compared to the same oxidation-sensitive amine that is not
treated with the amine-oxidation inhibitor.
19. A polyurethane product made using the composition of claim 1,
said polyurethane product exhibiting decreased amine oxidation
products as compared to the same polyurethane product made without
the composition of claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. patent application
Ser. No. 61/293,388, filed Jan. 8, 2010, which is incorporated
herein by reference.
TECHNICAL FIELD
[0002] This invention relates generally to preventing the formation
of or decreasing the presence of oxidation degradation products in
oxidation-sensitive amines, and more particularly to preventing the
formation of or decreasing the presence of formaldehyde and/or
dimethylformamide in oxidation-sensitive amines.
BACKGROUND
[0003] Amines, such as amine catalysts that are useful in the
polyurethane industry, may degrade over time or upon exposure to
air. As the amines degrade, undesirable products such as
formaldehyde and dimethylformamide (DMF), or both are produced. For
instance, formaldehyde may be formed by oxidative demethylation of
an amine and DMF may be obtained from certain tertiary amines by a
similar oxidation process as is shown in FIG. 1. Formaldehyde
and/or DMF from the amine may then be inadvertently incorporated
into polyurethane or polyisocyanurate formulations and hence into
the product of the formulation.
[0004] Such products include insulation for buildings and
appliances; flexible foams for beds, other furniture, and
automobile seats; elastomers such as shoe soles, skate wheels,
medical elastomers, and the like; urethane and/or urea coatings;
and high-modulus urethane plastics such as furniture foam, molded
doors, and rigid insulation panels just to name a few end
products.
[0005] Both formaldehyde and DMF are linked to human health risks.
Formaldehyde is a common indoor pollutant and may be toxic.
Furthermore, it may cause allergic reactions in
formaldehyde-sensitive people and it may be a human carcinogen. DMF
is a possible carcinogen and is believed to cause birth defects.
Thus, exposure to formaldehyde and DMF should be limited. Current
short-term exposure limits, such as 15 minutes, for DMF and
formaldehyde are 20 parts per million (ppm) and 2 ppm respectively
and longer permissible exposure limits, such as eight hours, for
DMF and formaldehyde are 10 ppm and 0.75 ppm respectively, as
determined by the Occupational Safety and Health Administration
(OSHA).
[0006] Depending upon the age of an oxidation-sensitive amine, DMF
and formaldehyde may be found in relatively high amounts. Thus,
there is a need for reduced concentrations of DMF and/or
formaldehyde in oxidation-sensitive amines
SUMMARY
[0007] In an embodiment of the present invention, an
amine-oxidation inhibitor such as a free radical scavenger and/or
an antioxidant is added to an oxidation-sensitive amine to inhibit
oxidation of the amine For example, when added to an
oxidation-sensitive amine, such as an amine catalyst, the
amine-oxidation inhibitor(s) may stop or reduce the formation of
undesired amine oxidation products. In an embodiment, the free
radical scavenger 1-methyl-3H-imidazole-2-thione (methimazole) may
be added to an amine catalyst to stop or reduce dimethylformamide
and/or formaldehyde formation. In other embodiments antioxidants
and azoles (imidazole, substituted imidazoles, substituted
benzothiazole and benzoxazole) may be used to obtain similar
results.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows possible pathways for forming amine oxidation
products such as dimethylformamide and formaldehyde;
[0009] FIG. 2 is a graph that shows the time dependent increase of
dimethylformamide at room temperature (.about.25.degree. C.) in a
sample of a tertiary amine catalyst;
[0010] FIG. 3 is a graph which shows the effect of various
concentrations of a free radical scavenger on dimethylformamide
formation in samples that were incubated for up to 682 days at
25.degree. C.;
[0011] FIG. 4 is a graph which shows the effect of various
concentrations of a free radical scavenger on dimethylformamide
formation in samples that were incubated for up to 39 days at
40.degree. C.;
[0012] FIG. 5 is a graph that shows the effect of various
concentrations of a free radical scavenger on dimethylformamide
formation in samples that were incubated for up to 39 days at
70.degree. C.
[0013] FIG. 6 is a graph showing the effects of two concentrations
of several antioxidants on dimethylformamide formation in samples
that were incubated for up to 368 days at 25.degree. C.;
[0014] FIG. 7 is a graph showing the effects of several
antioxidants on formaldehyde formation in samples that were
incubated for up to 368 days at 25.degree. C.;
[0015] FIG. 8 is a graph showing the effects of several
antioxidants on dimethylformamide formation in samples that were
incubated for up to 216 days at 40.degree. C.;
[0016] FIG. 9 is a graph that shows the effects of several
antioxidants on formaldehyde formation in samples that were
incubated for 217 days at 40.degree. C.;
[0017] FIG. 10 is a graph that shows the effects of two
concentrations of several azoles on dimethylformamide formation in
samples that were incubated for up to 140 days at 25.degree.
C.;
[0018] FIG. 11 is a graph that shows the effects of several azoles
on formaldehyde formation in samples that were incubated for up to
140 days at 25.degree. C.; and
[0019] FIG. 12 is a graph which shows the effects of several azoles
on dimethylformamide formation in samples that were incubated for
up to 93 days at 40.degree. C.
DETAILED DESCRIPTION
[0020] Oxidation is a concern for some amine products. For
instance, oxidation of urethane catalysts may lead to the
production of undesirable oxidation products, which may reduce the
shelf life and usability of the catalyst. Referring to FIG. 2, an
untreated urethane catalyst, bis-(2-dimethylaminoethyl)ether
(JEFFCAT.RTM. ZF-20), is oxidized in the presence of air at room
temperature such that there is a constant increase of the oxidation
product dimethylformamide (DMF) over time. For example, the
concentration of DMF increased from the initial concentration of 14
ppm to 1378 ppm in 136 days, to 2026 ppm in 369 days, and to 2350
ppm in 682 days. Because DMF is banned at least in some countries,
its production can limit product life and usability.
[0021] According to an embodiment of the present invention, an
oxidation-sensitive amine is treated with an amine-oxidation
inhibitor such as a free radical scavenger and/or an antioxidant to
inhibit oxidation of the amine. As a result, amine oxidation
products such as DMF and/or formaldehyde do not form or do not form
as readily, which may increase the shelf-life and usability of the
inhibitor-treated amine.
[0022] In another embodiment, such an inhibitor-treated amine may
be added to other oxidation-sensitive materials such as polyols,
isocyanates, blowing agents, and combinations thereof. The
inhibitor-treated amine, other oxidation-sensitive material, or
combinations thereof may then be used to make a product. As one
example, the inhibitor-treated amine may be a urethane catalyst for
use in the production of a polyurethane product. Using the
inhibitor-treated amine ensures minimal amounts of DMF and/or
formaldehyde in the urethane catalyst as well as in the urethane
foam product or other urethane product.
[0023] The oxidation-sensitive amine may be any amine that is
susceptible to oxidation. For example, the oxidation-sensitive
amine may be one or more amine-containing catalysts that are useful
in the production of polyurethanes, including polyurethane
elastomers, and/or polyisocyanurates. Such oxidation-sensitive
amine catalysts include tertiary amine-containing catalysts, amine
catalysts that catalyze urethane or urea reactions, or both.
Exemplary amine catalysts include, without limitation, tertiary
amine catalysts such as bis-(2-dimethyaminoethyl)ether
(JEFFCAT.RTM. ZF-20 catalyst),
N,N,N'-trimethyl-N'-hydroxyethylbisaminoethylether (JEFFCAT.RTM.
ZF-10 catalyst), N-(3-dimethylaminopropyl)-N,N-diisopropanolamine
(JEFFCAT.RTM. DPA catalyst), N,N-dimethylethanolamine (JEFFCAT.RTM.
DMEA catalyst), triethylene diamine (JEFFCAT.RTM. TEDA catalyst),
blends of
[0024] N,N-dimethylethanolamine and triethylene diamine (such as
JEFFCAT.RTM. TD-20 catalyst), N,N-dimethylcyclohexylamine
(JEFFCAT.RTM. DMCHA catalyst), benzyldimethylamine (JEFFCAT.RTM.
BDMA catalyst), pentamethyldiethylenetriamine (JEFFCAT.RTM. PMDETA
catalyst), N,N,N',N'',N''-pentamethyldipropylenetriamine
(JEFFCAT.RTM. ZR-40 catalyst),
N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine (JEFFCAT.RTM.
ZR-50 catalyst), N-(3-dimethylaminopropyl)-N,N-diisopropanolamine
(JEFFCAT.RTM. DPA catalyst),
N'-(3-(dimethylamino)propyl-N,N-dimethyl-1,3-propanediamine
(JEFFCAT.RTM. Z-130 catalyst), 2-(2-dimethylaminoethoxy)ethanol
(JEFFCAT.RTM. ZR-70 catalyst),
N,N,N'-trimethylaminoethyl-ethanolamine (JEFFCAT.RTM. Z-110
catalyst), N-ethylmorpholine (JEFFCAT.RTM. NEM catalyst),
N-methylmorpholine (JEFFCAT.RTM. NMM catalyst),
4-methoxyethylmorpholine, N, N'dimethylpiperzine (JEFFCAT.RTM. DMP
catalyst), 2,2'dimorpholinodiethylether (JEFFCAT.RTM. DMDEE
catalyst), 1,3,5-tris(3-(dimethylamino)propyl)-hexahydro-s-triazine
(JEFFCAT.RTM. TR-90 catalyst), 1-Propanamine,
3-(2-(dimethylamino)ethoxy), and combinations thereof The
aforementioned JEFFCAT.RTM. catalysts are available from Huntsman
Petrochemical LLC, The Woodlands, Tex.
[0025] In other embodiments, the oxidation-sensitive amine may be
one or more of a polyetheramine, ethyleneamine, alkoxylated amine,
and surfactant amine, although embodiments are not so limited.
Suitable polyetheramines include monoamines such as JEFFAMINE.RTM.
M-1000. amine, JEFFAMINE.RTM. M-2005 amine, and JEFFAMINE.RTM.
M-2070 amine; diamines such JEFFAMINE.RTM. D-230 amine,
JEFFAMINE.RTM. D-400 amine, and JEFFAMINE.RTM. D-2000 amine;
polyether diamines such as JEFFAMINE.RTM. HK-511 amine,
JEFFAMINE.RTM. ED-600 amine, JEFFAMINE.RTM. ED-900 amine, and
JEFFAMINE.RTM. ED-2003 amine; unhindered diamines such as
JEFFAMINE.RTM. EDR-104 amine, JEFFAMINE.RTM. EDR-148 amine, and
JEFFAMINE.RTM. EDR-176 amine; triamines such as JEFFAMINE.RTM.
T-403 amine, JEFFAMINE.RTM. T-3000 amine, and JEFFAMINE.RTM. T-5000
amine; and mixtures of polyether monoamines and diamines such as
aminated triethyleneglycol (e.g. JEFFAMINE.RTM. XTJ-512 amine), and
the like; suitable ethyleneamines include ethylenediamine (EDA),
diethylenetriamine (DETA), triethylenetetramine (TETA),
tetraethylenepentamine (TEPA), aminoethylpiperzine (AEP),
aminoethylethanolamine (AEEA), pentaethylenehexamine (PEHA),
hexaethyleneheptamine (HEHA), and mixtures thereof; suitable
alkoxylated amines include 2-(2-aminoethoxy)ethanol (DGA.RTM.
amine), diethanolamine (DEA), N-methyldiethanolamine (MDEA),
triethanolamine (TEA), and the like; and suitable surfactant amines
include hydrophobic polyether monoamines such as SURFONAMINE.RTM.
B-100 amine and SURFONAMINE.RTM. B-200 amine, and hydrophilic
polyether monoamines such as SURFONAMINE.RTM. L-100 amine,
SURFONAMINE.RTM. L-200 amine, SURFONAMINE.RTM. L-207 amine,
SURFONAMINE.RTM. L-300 amine, and the like. JEFFAMINE.RTM.
products, SURFONAMINE.RTM. products, and DGA.RTM. product are
available from Huntsman Petrochemical LLC, The Woodlands, Tex.
[0026] The amine-oxidation inhibitor may be any suitable inhibitor
such as an antioxidant and/or free radical scavenger. Suitable
amine-oxidation inhibitors include those that are compatible with,
and that can inhibit oxidation of, one or more amines such as amine
catalysts, polyetheramines, ethyleneamines, alkoxylated amines,
and/or surfactant amines, although embodiments are not limited
thereto. In an embodiment the amine-oxidation inhibitor may be one
or more free radical scavengers such as methimazole, phenyl
methimazole, and derivatives thereof; allupurinol, propyl
thiouracil, glutamine, diaminobenzylamine, and nicotinamide to name
a few. Other suitable amine-oxidation inhibitors may be one or more
antioxidants that are compatible with an oxidation-sensitive amine,
such as an amine catalyst, and that can suppress
free-radical-mediated DMF and/or formaldehyde formation. The
antioxidants may be hindered phenolics such as butylated hydroxy
toluene, IRGASTAB.RTM. PUR 68 antioxidant, IRGANOX.RTM. 1010
antioxidant, IRGANOX.RTM. 1135 antioxidant, and IRGANOX.RTM. 1076
antioxidant; hindered aliphatic amines such as TINUVIN.RTM. 770
light stabilizer; hindered aromatic amines such as IRGASTAB.RTM.
PUR 55 antioxidant, IRGANOX.RTM. 5057 antioxidant, and NAUGARD.RTM.
445 antioxidant; mixed phenolics and amines such as IRGANOX.RTM. MD
1024 antioxidant and IRGANOX.RTM. 565; antioxidants with triazole
and phenolic groups such as TINUVIN.RTM. P antioxidant,
TINUVIN.RTM. 234 antioxidant, TINUVIN.RTM. 327 antioxidant, and
TINUVIN.RTM. 328 antioxidant; proprietary antioxidants such as
TINUVIN.RTM. 866 antioxidant; and natural antioxidants such as
Vitamin C, Vitamin E and/or glutathione, although embodiments are
not limited to these exemplary antioxidants. Furthermore, in some
embodiments, the amine-oxidation inhibitor may be a combination of
one or more free radical inhibitors and antioxidants. IGASTAB.RTM.,
IRGANOX.RTM., and TINUVIN.RTM. products are available from Ciba
Specialty Chemical Corporation, Tarrytown, N.Y., and NAUGARD.RTM.
products are available from Chemtura Corporation, Middlebury,
Conn..
[0027] Azoles such as substituted imidazoles, arylimidazoles have
been found to show inhibitory activity toward hydroxylation and
N-demethylation. These inhibitors may be imidazole,
2-mercaptoimidazole, 2-mercaptobenzimidazole,
2-mercaptobenzothiazole, 2-mercaptobenzoxazole, triazole and
substituted triazoles, although embodiments are not limited to
these exemplary azoles.
[0028] The oxidation-sensitive amine may be treated with the
amine-oxidation inhibitor at any time. For example, in some
embodiments the amine-oxidation inhibitor may be added to the
oxidation-sensitive amine just before use or any other point where
exposure to air is possible. Alternatively, the amine-oxidation
inhibitor may be added to the oxidation-sensitive amine at
production, for storage. In a particular embodiment, the container
in which the inhibitor-treated amine is stored is padded with an
inert gas. In a preferred embodiment, the headspace of the
container holding an inhibitor-treated amine may be padded with
nitrogen for better stability. These examples are nonlimiting and
an amine-oxidation inhibitor may be added to an oxidation-sensitive
amine at any time and in any manner.
[0029] The amount of amine-oxidation inhibitor added to an
oxidation-sensitive amine may be any effective amount. For example,
in some embodiments, the oxidation-sensitive amine may be treated
with 5 ppm, 10 ppm, 100 ppm, 250 ppm, 1000 ppm, or 5000 ppm of an
amine-oxidation inhibitor, and all amounts there between. In other
embodiments, an amine-oxidation inhibitor may be added to an
oxidation-sensitive amine to form a blend where the amount of
amine-oxidation inhibitor in the blend is from 0.5% to 10% by
weight of the total blend. In an embodiment, the aforementioned
blend may be used as a concentrate to enable customization to a
desired inhibitor concentration level. For example, the
concentrated blend may be mixed with an untreated
oxidation-sensitive amine to reach a desired amine-oxidation
inhibitor level. These examples are also non-limiting and the
amount of amine-oxidation inhibitor used to treat a particular
oxidation-sensitive amine may be adjusted according to factors such
as the type of amine, estimated storage time, and application. The
temperature and pressure at which the amine-oxidation inhibitor is
effective may depend on various factors including the amount of
amine-oxidation inhibitor used to treat the oxidation-sensitive
amine. Generally, the amine-oxidation inhibitor may be effective at
temperatures from 0.degree. C. to 150.degree. C. and at pressures
up to 200 psi (pounds per square inch). In some embodiments, the
amine-oxidation inhibitor is especially effective at 25.degree. C.,
40.degree. C., or 70.degree. C. and ranges there between.
[0030] In another embodiment, an inhibitor-treated amine (e.g. an
amine that has been treated with a suitable amine-oxidation
inhibitor) may be added to other oxidation-sensitive materials. In
a particular embodiment, an inhibitor-treated amine may be added to
one or more components for making a polyurethane product, a
polyisocyanurate product, or any other polyurethane products.
Generally, a polyurethane product (or a polyisocyanurate product)
may be formed by reacting an isocyanate component with a polyol
component. One or more inhibitor-treated amines such as an amine
catalyst may be added to the isocyanate component, the polyol
component, or both. Additionally or alternatively, the
inhibitor-treated amine may be added to one or more sub-components,
such as blowing agents, additives, or auxiliary agents, which may
then be added to the polyol component and/or the isocyanate
component. As such, resultant polyurethane/polyisocyanurate
products may contain reduced oxidation products such as DMF,
formaldehyde, or both, which means that less of these oxidation
products may be emitted from the product.
[0031] The isocyanate component may be any isocyanate or
combinations of isocyanates known in the field of polyurethanes
and/or polyisocyanurates. Examples of such isocyanates include,
without limitation, toluenediisocyanate (TDI),
methylenediphenyldiisocyante (MDI), higher functional (greater than
2) methylenediphenyldiisocyanates (poly MDI or pMDI), and
pre-polymers/quasi-prepolymers of these isocyanates. In some
embodiments, an inhibitor-treated amine such as an
inhibitor-treated amine catalyst may be added to the isocyanate
component. In a particular embodiment, the inhibitor-treated amine
catalyst is an inhibitor-treated urethane catalyst.
[0032] The polyol component may include any polyol or combinations
of polyols that are useful in the fields of
polyurethanes/polyisocyanurates. For example, the polyol component
may include polyether polyols, polyester polyols, any other polyol,
and combinations of polyols. Furthermore, the polyols may be made
from mono-, di-, tri-, or higher functional initiators and they may
include alkylene oxides such as ethylene oxide, propylene oxide,
butylene oxide and/or any combination of these or other oxides. An
example of polyether polyols includes polyoxypropylene and/or
polyoxyethylene polyols, and an example of polyester polyols
includes aromatic polyester polyols and/or aliphatic polyester
polyols. Particularly useful polyols include propylene glycol
initiated polyols such as JEFFOL.RTM. PPG-2000 polyol, propylene
oxide-ethylene oxide co-polymers such as JEFFOL.RTM. G-31-28 polyol
and JEFFOL.RTM. PPG-3706 polyol, polyether polyols such as
VORANOL.RTM. 4701 polyol and VORANOL.RTM. 4702 polyol. JEFFOL.RTM.
products may be obtained from Huntsman International LLC, The
Woodlands, Tex.; VORANOL.RTM. products may be obtained from Dow
Chemical Company, Midland, Mich..
[0033] The polyol component may also include one or more low
molecular weight chain extenders, crosslinking agents, or mixtures
of chain extenders and crosslinking agents. Chain extenders may
include alkane diols, dialkylene glycols, polyalkylene polyols, and
combinations thereof, and crosslinking agents may include
ethanediols, butanediols, hexanediols, heptanediols, octanediols,
nonanediols, diethylene glycol, dipropylene glycol, polyoxyalkylene
glycols, and combinations thereof.
[0034] In some embodiments, an inhibitor-treated amine such as an
inhibitor-treated amine catalyst may be added to one or more
polyols of the composition. In a particular embodiment, the
inhibitor-treated amine catalyst is an inhibitor-treated urethane
catalyst.
[0035] In some embodiments, a blowing agent may be added to the
isocyanate component or the polyol component. Furthermore, the
blowing agent may or may not have an inhibitor-treated amine added
thereto. The blowing agent may be any blowing agent or combination
of blowing agents useful in the art of polyurethanes and/or
polyisocyanurates. Generally, such blowing agents include water,
physical blowing agents, and chemical blowing agents, which may be
used alone or in combinations. Exemplary blowing agents include,
but are not limited to, water, pentane, cyclopentane, butane,
FORANE.RTM. 141B agent, which is available from Arkema Inc.
(Philadelphia, Pa.), and HFC-245FA, which is available from
Honeywell International Inc. (Morristown, N.J.).
[0036] Typically, the polyol component may include additives and/or
auxiliary agents. Exemplary additives and/or auxiliary agents
include film stabilizers, cell regulators, flame retardants,
plasticizers, fillers, pigments, surfactants, and the like, or any
combination thereof. To the extent that an additive or auxiliary
agent is an oxidation-sensitive amine, an amine-oxidation inhibitor
may be added to such additive or auxiliary agent.
[0037] The polyurethanes or polyisocyanurates may be made using any
technique. For instance, a polyurethane or polyisocyanurate may be
formed by separately blending the components of the polyol
component and the isocyanate component, either or both of which may
include an inhibitor-treated catalyst and/or other
inhibitor-treated amine. Once separately blended, the two
components may be mixed by any means known in the art. For example,
the polyol component and the isocyanate component may be mixed to
facilitate the manufacture of a molded product or a product made
without a mold.
[0038] Embodiments however are not limited to polyurethanes and/or
polyisocyanurates; the inhibitor-treated amine may be used in any
application where free radical mediated oxidation may occur.
Furthermore, there is no restriction on when the inhibitor-treated
amine may be added to another oxidation-sensitive material;
however, it may be beneficial to add the inhibitor-treated amine
before storing the other oxidation-sensitive material or just
before its use. Likewise, there may be a wide range of temperatures
at which an inhibitor is effective such as temperatures from
0.degree. C. to 150.degree. C., and pressures may be up to 200
psi.
EXAMPLES
[0039] The following non-limiting examples are provided to further
illustrate embodiments described herein. The examples, however, are
not intended to be all-inclusive and are not intended to limit the
scope of the embodiments described herein.
Example 1
[0040] In Examples 1a-1c, DMF and formaldehyde concentrations were
tracked in samples of a tertiary amine mixed with methimazole (MM).
Generally, 50 ml each of 10, 100, 250, and 1000 ppm methimazole (an
amine-oxidation inhibitor) solutions were prepared with
bis-(2-dimethyaminethyl)ether (JEFFCAT.RTM. ZF-20 amine catalyst,
available from Huntsman Petrochemical LLC, The Woodlands, Tex.).
Methimazole is available from Sigma-Aldrich Corp., St. Louis,
Mo.
[0041] An 8 ml aliquot from each of the foregoing preparations was
poured in a corresponding 20 ml vial and an 8 ml aliquot of
untreated JEFFCAT.RTM. ZF-20 amine catalyst was poured in a
separate 20 ml vial. Thus, there were five 20 ml vials in a set; at
least one sample per set had 0, 10, 100, 250, or 1000 ppm
methimazole. Sets of samples were incubated at 25.degree. C.,
40.degree. C., or 70.degree. C. Periodically, a portion of each
sample (about 0.4 ml) was withdrawn to determine the concentration
of DMF and/or formaldehyde formed in that sample. DMF and
formaldehyde concentrations were determined by high performance
liquid chromatography with a UV detector.
Example 1a
[0042] In this example, DMF and formaldehyde concentrations were
tracked in a set of samples that were incubated at room temperature
(about 25.degree. C.) for up to 680 days. Sample la (Neat ZF-20)
was a control sample having no methimazole, and samples 2a, 3a, 4a,
and 5a were test samples, which included 10, 100, 250, and 1000 ppm
of methimazole, respectively. Prior to incubation, baseline DMF and
formaldehyde concentrations were determined. Thereafter, for each
sample in the set, DMF and formaldehyde concentrations were
periodically determined.
[0043] Referring to FIG. 3, DMF concentrations (ppm) at different
time-points are shown for samples la-5a. After about 1 day (18
hours) of incubation, the samples do not show an appreciable
difference in DMF accumulation. Thereafter, however, the DMF
concentration in sample la began to rise compared to the test
samples, and by 12 days and thereafter the difference in DMF
concentration between control sample 1a and the test samples was
quite dramatic. This is especially true for the difference in DMF
concentrations between sample 1a and samples 4a and 5a.
[0044] Referring to Table 1 below, DMF concentrations (in ppm) for
samples 1a, 4a, and 5a are shown. The initial DMF content for these
samples was 14 ppm. After incubating at 25.degree. C. for 39 days,
however, the DMF concentration in sample la rose to 812 ppm, and
for samples 4a and 5a the DMF concentrations were less than 100 ppm
and less than 25 ppm, respectively. Thus, at this time point much
less DMF was formed in test samples 4a and 5a as compared to the
control sample la. Similarly, after incubating for 136 days the DMF
content in sample 1 a rose to 1378 ppm (about 100 fold from the
initial concentration) whereas it was only 337 ppm and 35 ppm in
samples 4a and 5a respectively. Similarly, after 232 days, the DMF
contents of samples 4a and 5a were 588 ppm and 184 ppm,
respectively, compared to 1940 ppm for control sample 1a. Thus, at
25.degree. C., which is about room temperature, samples with
methimazole, especially those samples with 250 and 1000 ppm
methimazole, had lower DMF concentrations compared to the control
sample with no methimazole. Referring to Table 1 and FIG. 3, this
trend continued for all time points up to 682 days. However, DMF
concentration from samples 5a was found to approach that from
sample 4a at 521 days and eventually, DMF concentrations were
higher for sample 5a compared to sample 4a at time points of 597
days and 682 days.
TABLE-US-00001 TABLE 1 Initial Methimazole DMF 39 days 136 days 232
days 369 days 682 days Sample (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)
(ppm) 1a 0 14 812 1378 1940 2026 2350 4a 250 14 97 337 588 710 1197
5a 1000 14 21 35 184 503 1411
[0045] Referring to Table 2 below, it was observed that the free
radical scavenger methimazole also prevented formaldehyde build-up
in samples 4a and 5a (compared to control sample 1a). For example,
the initial formaldehyde content in samples 1a, 4a, and 5a was 50
ppm. After incubating at 25.degree. C. for 521 days, however,
control sample 1a had 772 ppm formaldehyde and test samples 4a and
5a had 538 ppm and 580 ppm formaldehyde, respectively. After being
incubated for 682 days at 25.degree. C., the formaldehyde
concentration for samples 4a increased to 548 ppm, but still well
below the formaldehyde concentration of the control sample at 851
ppm. However, formaldehyde concentration of 782 ppm for the sample
5a was close to that of the control sample at this time point.
TABLE-US-00002 TABLE 2 Initial Methimazole Formaldehyde 521 days
682 days Sample (ppm) (ppm) (ppm) (ppm) 1a 0 50 772 851 4a 250 50
538 548 5a 1000 50 580 782
[0046] The amounts of methimazole remaining in the samples after
being incubated for 136 days, 232 days, 368 days and 682 days at
25.degree. C. were also determined. Similar to DMF, methimazole was
determined by high performance liquid chromatography with UV
detection. Referring to Table 3, samples 2a and 3a, which initially
included 10 and 100 ppm methimazole respectively, were both
methimazole-free after 136 days. In contrast, samples 4a and 5a
still had 30 ppm and 760 ppm methimazole, respectively remaining
after 136 days. Additional losses of methimazole from samples 4a
and 5a were observed after 232 days. After 682 days, sample 5a was
left with only 70 ppm of methimazole down from 1000 ppm.
TABLE-US-00003 TABLE 3 Initial Methimazole 136 days 232 days 369
days 682 days Sample (ppm) (ppm) (ppm) (ppm) (ppm) 2a 10 0 0 0 0 3a
100 0 0 0 0 4a 250 30 21 20 5 5a 1000 760 637 435 70
Example 1b
[0047] In this example, a set of samples was analyzed for the
presence of DMF after being incubated in an oven at 40.degree. C.
for a total of 39 days. Sample lb was a control sample having no
methimazole and samples 2b, 3b, 4b, and 5b were test samples, which
included 10, 100, 250, and 1000 ppm of methimazole,
respectively.
[0048] Referring to FIG. 4, DMF concentrations in samples 1b-5b are
shown. As with the control sample la, control sample lb showed a
steady increase of DMF concentration over the 39 days. In contrast,
samples 2b-5b had a reduced DMF formation over time compared to the
control lb. The most effective concentration of methimazole at
40.degree. C. was 1000 ppm. Interestingly, sample 4b, which
included 250 ppm methimazole, did not appear to be as effective at
40.degree. C. at or after 18 days of incubation as sample 3b, which
included 100 ppm methimazole.
Example 1c
[0049] In this example, a set of catalyst samples was analyzed for
the presence of DMF after being incubated in an oven at 70.degree.
C. for a total of 39 days. Sample 1c was a control catalyst sample
having no methimazole and catalyst samples 2c, 3c, 4c, and 5c were
test catalyst samples, which, in addition to the amine catalyst,
included 10, 100, 250, and 1000 ppm of methimazole,
respectively.
[0050] Referring to FIG. 5, DMF concentrations in catalyst samples
1c-5c are shown. As with the other control samples, control sample
1c showed a steady increase in DMF formation over the 39 day
incubation period. The methimazole in samples 2c and 3c did not
affect DMF formation at this temperature. In fact, DMF formation in
sample 3c, which included 100 ppm methimazole, was greater than
control (1c) at most time points. DMF formation in sample 4c (250
ppm methimazole), however, was usually less than the control sample
at the various time points. As with the other temperatures, the
sample having 1000 ppm methimazole (5c) showed the biggest
reduction in DMF formation over the entire incubation period as
compared to the control 1c.
[0051] It should be noted that the data obtained for Examples 1b
and 1c had a higher level of uncertainty, which was believed to be
due to evaporation loss of some DMF. The evaporation loss was
measured by weighing sample before placing the sample in the oven
and after taking it out from the oven and cooling. Typical
evaporation losses were found to be 0.2% and 0.4% at 40.degree. C.
and 70.degree. C., respectively.
Example 2
[0052] In this example, aldehyde emissions from flexible foams were
determined. Generally, a control foam and a test foam were made
using the same formula:
TABLE-US-00004 TABLE 4 Component Weight % EO-capped Polyol of MW
6000 58.75 Water 2.36 JEFFCAT .RTM. ZF-10 catalyst 0.05 JEFFCAT
.RTM. DPA catalyst 0.6 Silicone surfactant 0.5 Stabilizer
(diethanolamine) 0.24 Isocyanates (MDI) 37.5 Total 100.0
wherein the catalyst used in the control foam was methimazole-free
and the catalyst used in the test foam contained 1000 ppm
methimazole. In the above formulation, JEFFCAT.RTM. ZF-10 catalyst
and JEFFCAT.RTM. DPA catalyst are tertiary amines, and serve as
reactive catalysts. These are available from Huntsman Petrochemical
LLC, The Woodlands, Tex.
[0053] Before use in the foam formulation, catalysts for the test
foam were prepared by adding enough methimazole to each of the
JEFFCAT.RTM. ZF-10 catalyst and the JEFFCAT.RTM. DPA catalyst to
give 1000 ppm methimazole per catalyst. The concentrations of
aldehydes and ketone in JEFFCAT.RTM. ZF-10 catalyst prior to adding
methimazole were as follows: formaldehyde 46 ppm, acetaldehyde 41
ppm, acetone 0.1 ppm, propionaldehyde 1.1 ppm, and butyraldehyde 0
ppm. The corresponding concentrations for JEFFCAT.RTM. DPA catalyst
were as follows: formaldehyde 12 ppm, acetaldehyde 9.3 ppm, acetone
6.0 ppm, propionaldehyde 22 ppm, and butyraldehyde 0 ppm. Catalysts
for the control foam were from the same catalyst batches as that of
the test foam, but without having any free radical scavenger added
thereto.
[0054] Generally, the foams were made by mixing the polyol, water,
respective catalysts, silicone surfactant, and stabilizer in a
mixing cup for 24 seconds. Thereafter, the isocyanate was added to
the polyol mixture, which was then stirred for 6 seconds and poured
into a block mold 65 cm.times.60 cm.times.10 cm. The foams were
allowed to cure for 3 minutes at 60 .degree. C.
[0055] The foam blocks were then tested for aldehyde emission in a
manner similar to ASTM D-5116-06. For this, a model VCE 1000
instrument from Votsch Industrietechnik (Germany)was used for
environmental chamber testing. The size of the chamber was 1000
liter. The sample size was one piece of 65 cm.times.60 cm.times.10
cm foam block. The temperature of the chamber was maintained at
65.degree. C. and the humidity was maintained at 50%. The zero air
exchange rate was 400 L/h. Volatile aldehydes given off by the foam
were drawn at the exhaust flow outlet through a
2,4-dinitrophenylhydrazine (DNPH)-coated silica gel cartridge using
a sampling pump for 5 hours. After sample collection, aldehydes
were eluted from each DNPH cartridge with 5 ml acetonitrile and
determined by HPLC-UV detection.
[0056] Referring to Table 5 below, the presence of formaldehyde,
acetaldehyde, propionaldehyde, and butyraldehyde was evaluated in
both the control and test foam samples. As compared to the control
foam, the concentration of each gas was less in the test foam.
Thus, free radical scavenger added to catalyst samples also has a
beneficial affect on the foams made from such catalysts.
TABLE-US-00005 TABLE 5 Pro- Foam Formaldehyde Acetaldehyde
pionaldehyde Butyraldehyde Sample (.mu.g/m.sup.3) (.mu.g/m.sup.3)
(.mu.g/m.sup.3) (.mu.g/m.sup.3) Control 85 18 108 38 Test 20 3 29
14
Example 3
[0057] In Examples 3a-3b, DMF and formaldehyde concentrations were
tracked in samples of a tertiary amine, JEFFCAT.RTM. ZF-20 mixed
with antioxidants. Generally, 25 ml each of 200 ppm, and 1000 ppm
antioxidant solutions were prepared with JEFFCAT.RTM. ZF-20 amine
catalyst. Untreated JEFFCAT.RTM. ZF-20 (Neat ZF-20) was used as
control sample. As antioxidants, IRGANOX.RTM. 1010 (Irg 1010),
IRGANOX.RTM. MD 1024 (MD 1024), TINUVIN.RTM. 866 (Tin 866),
TINUVIN.RTM. 328 (Tin 328), and TINUVIN.RTM. 770 (Tin 770) were
studied. These were available from Sigma-Aldrich Corp., St. Louis,
Mo. In FIGS. 6 to 9, these antioxidants are referred to by
abbreviations shown in parentheses.
[0058] An 8 ml aliquot from each of the foregoing preparations was
poured in a corresponding 20 ml vial and an 8 ml aliquot of
untreated JEFFCAT.RTM. ZF-20 amine catalyst was poured in a
separate 20 ml vial. Thus, there were two 20 ml vials for each
antioxidant; for example, Irg 1010, 200 ppm and Irg 1010, 1000 ppm
are two solutions with 200 ppm and 1000 ppm of IRGANOX.RTM. 1010
antioxidant, respectively. Thus, there were eleven sample solutions
in each set of samples. Sets of samples were incubated at
25.degree. C. and 40.degree. C. Periodically, a portion of each
sample (about 0.4 ml) was withdrawn to determine the concentration
of DMF and/or formaldehyde formed in that sample. DMF and
formaldehyde concentrations were determined by high performance
liquid chromatography with a UV detector.
Example 3a
[0059] Referring to FIG. 6, DMF concentrations at different
time-points and at 25.degree. C. are shown for a set of eleven
sample solutions. The initial DMF concentration in JEFFCAT.RTM.
ZF-20 was 18.9 ppm. The DMF concentrations in samples Neat ZF-20,
Tin 770, 200 ppm and Tin 770, 1000 ppm began to rise faster than
other test samples after 4 days. Thereafter the difference in DMF
concentration between control sample and the test samples was quite
significant. Almost at all time points, the lowest DMF
concentrations were observed in samples with 1000 ppm IRGANOX.RTM.
MD 1024, followed by 1000 ppm IRGANOX.RTM. 1010 and 200 ppm
IRGANOX.RTM. 1010. However, this study for 368 days suggests that
all solutions except two TINUVIN.RTM. 770 solutions, produced lower
DMF amounts compared to the control sample.
[0060] Referring to FIG. 7, a study with antioxidants for a period
of 368 days, showed that two antioxidants IRGANOX.RTM. 1010 and
IRGANOX.RTM. MD 1024 can provide reduced formaldehyde build-up
compared to the control sample. Both antioxidants at 1000 ppm, and
Irg 1010 at 200 ppm were found to be effective.
Example 3b
[0061] Referring to FIG. 8, the second set of samples was analyzed
for the presence of DMF after being incubated in an oven at
40.degree. C. for a total of 216 days. Here, DMF concentrations
remain relatively low at 163 ppm or less for a period of 18 days.
Thereafter, as with the control sample, all samples showed a steady
increase of DMF concentration. However, samples Irg 1010, 1000 ppm
and MD 1024, 1000 ppm had reduced DMF formation over time compared
to the control sample.
[0062] Referring to FIG. 9, formaldehyde concentrations were
measured for all samples incubated in an oven for 217 days. The
formaldehyde concentrations in JEFFCAT.RTM. ZF-20 at the end of the
incubation period showed that Irg 1010, 1000 ppm and MD 1024, 1000
ppm were effective in slowing down formaldehyde formation in the
amine catalyst.
Example 4
[0063] In Examples 4a and 4b, DMF and formaldehyde concentrations
were tracked in samples of a tertiary amine, JEFFCAT.RTM. ZF-20,
mixed with azoles. Generally, 25 ml each of 200 ppm, and 1000 ppm
azole solutions were prepared with JEFFCAT.RTM. ZF-20 amine
catalyst. Untreated JEFFCAT.RTM. ZF-20 (Neat ZF-20) was used as the
control sample. The following azoles were studied:
2-mercaptoimidazole (2-MCIZ), 2-mercaptobenzimidazole (2-MCBIZ),
2-mercaptobenzothiazole (2-MCBTZ), 2-mercaptobenzoxazole (2-MCBOZ)
and imidazole (IMIDAZ). These are available from Sigma-Aldrich
Corp., St. Louis, Mo. In FIGS. 10 to 12, these azoles are referred
to by abbreviations shown in parentheses.
[0064] An 8 ml aliquot from each of the azole preparations was
poured in a corresponding 20 ml vial and an 8 ml aliquot of
untreated JEFFCAT.RTM. ZF-20 amine catalyst was poured in a
separate 20 ml vial. Thus, there were two 20 ml vials for each
azole. For example, 2-MCIZ, 200 ppm and 2-MCIZ, 1000 ppm are two
solutions with 200 ppm and 1000 ppm of 2-mercaptoimidazole,
respectively. Thus, there were eleven sample solutions in each set
of samples. Sets of samples were incubated at 25.degree. C. and
40.degree. C. Periodically, a portion of each sample (about 0.4 ml)
was withdrawn to determine the concentration of DMF and/or
formaldehyde formed in that sample. DMF and formaldehyde
concentrations were determined by high performance liquid
chromatography with a UV detector.
Example 4a
[0065] Referring to FIG. 10, DMF concentrations at different
time-points up to 140 days and at 25.degree. C. are shown for a set
of eleven sample solutions. The initial DMF concentration in
JEFFCAT.RTM. ZF-20 was 18.1 ppm. Compared to the control sample
(Neat ZF-20) solution, 2-mercaptoimidazole, 2-mercaptobezoxazole
and imidazole solutions showed reduced amounts of DMF. Both
2-mercaptobenzimidazole and 2-mercaptobenzothiazole provided
comparable or higher DMF amounts as compared to the control sample
at almost all time points
[0066] Referring to FIG. 11, a study with azole solutions for a
period of 140 days, suggests that formaldehyde data are scattered.
However, 2-mercaptoimidazole, 2-mercaptobezoxazole and imidazole
showed some advantages compared to the control sample
Example 4b
[0067] Referring to FIG. 12, the second set of samples was analyzed
for the presence of DMF after being incubated in an oven at
40.degree. C. for a total of 93 days. Here, DMF concentrations
increased steadily in all solutions. However, samples 2-MCBOZ, 200
ppm and IMIDAZ 1000 ppm provided reduced DMF amounts compared to
the control sample at all time points.
Example 5
[0068] In Example 5, a tertiary amine, JEFFCAT.RTM. ZF-20 sample in
a 20 mL vial was stored for a period of 370 days at room
temperature in a nitrogen box after blanketing with nitrogen. DMF
and formaldehyde concentrations were measured at the start and at
the end of the experiment. The initial DMF concentration was 18.9
ppm and that after 370 days was 36 ppm. The corresponding
formaldehyde amounts are 60 ppm and 221 ppm, respectively.
[0069] The above disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments, which fall within the true scope of the present
invention. Thus, to the maximum extent allowed by law, the scope of
the present invention is to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing detailed description.
* * * * *