U.S. patent application number 17/501967 was filed with the patent office on 2022-04-07 for amine catalysts for polyurethane foams.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. The applicant listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Haridasan K. Nair, David Nalewajek, Michael Van Der Puy, David J. Williams.
Application Number | 20220106430 17/501967 |
Document ID | / |
Family ID | |
Filed Date | 2022-04-07 |
United States Patent
Application |
20220106430 |
Kind Code |
A1 |
Van Der Puy; Michael ; et
al. |
April 7, 2022 |
AMINE CATALYSTS FOR POLYURETHANE FOAMS
Abstract
The invention provides polyurethane and polyisocyanurate foams
and methods for the preparation thereof. More particularly, the
invention relates to open-celled, polyurethane and polyisocyanurate
foams and methods for their preparation. The foams are
characterized by a fine uniform cell structure and little or no
foam collapse. The foams are produced with a polyol premix
composition which comprises a combination of a hydrohaloolefin
blowing agent, a polyol, a silicone surfactant, and a sterically
hindered amine catalyst.
Inventors: |
Van Der Puy; Michael;
(Charlotte, NC) ; Williams; David J.; (Charlotte,
NC) ; Nair; Haridasan K.; (Charlotte, NC) ;
Nalewajek; David; (Charlotte, NC) |
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Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
Charlotte |
NC |
US |
|
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Assignee: |
HONEYWELL INTERNATIONAL
INC.
Charlotte
NC
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Appl. No.: |
17/501967 |
Filed: |
October 14, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16160438 |
Oct 15, 2018 |
11149105 |
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17501967 |
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15378297 |
Dec 14, 2016 |
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16160438 |
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12241606 |
Sep 30, 2008 |
9550854 |
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15378297 |
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60979453 |
Oct 12, 2007 |
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International
Class: |
C08G 18/18 20060101
C08G018/18; C08G 18/40 20060101 C08G018/40; C08J 9/14 20060101
C08J009/14 |
Claims
1. A polyol premix composition which comprises a combination of a
blowing agent, a polyol, a silicone surfactant, and a sterically
hindered amine catalyst; wherein the blowing agent comprises a
hydrohaloolefin, and optionally a hydrocarbon, fluorocarbon,
chlorocarbon, fluorochlorocarbon, halogenated hydrocarbon, CO.sub.2
generating material, or combinations thereof wherein the sterically
hindered amine catalyst has the formula
R.sub.1R.sub.2N-[A-NR.sub.3].sub.nR.sub.4 wherein each of R.sub.1,
R.sub.2, R.sub.3, and R.sub.4 is independently H, a C.sub.1 to
C.sub.8 alkyl group, a C.sub.1 to C.sub.8 alkenyl group, a C.sub.1
to C.sub.8 alcohol group, or a C.sub.1 to C.sub.8 ether group, or
R.sub.1 and R.sub.2 together form a C.sub.5 to C.sub.7 cyclic alkyl
group, a C.sub.5 to C.sub.7 cyclic alkenyl group, a C.sub.5 to
C.sub.7 heterocyclic alkyl group, or a C.sub.5 to C.sub.7
heterocyclic alkenyl group; A is a C.sub.1 to C.sub.5 alkyl group,
a C.sub.1 to C.sub.5 alkenyl group, or an ether; n is 0, 1, 2, or
3; with the proviso that the sterically hindered amine catalyst has
a sum of Charton's steric parameters of about 1.65 or greater.
2. The polyol premix composition of claim 1 wherein the
hydrohaloolefin comprise at least one fluoroalkene or chloroalkene
containing from 3 to 4 carbon atoms and at least one carbon-carbon
double bond.
3. The polyol premix composition of claim 1 wherein the
hydrohaloolefin comprises a trifluoropropenes, a
tetrafluoropropenes, a pentafluoropropene, a chlorodifluoropropene,
a chlorotrifluoropropene, a chlorotetrafluoropropene, or
combinations thereof.
4. The polyol premix composition of claim 1 wherein the
hydrohaloolefin comprises 1,3,3,3-tetrafluoropropene;
2,3,3,3-tetrafluoropropene; 1,1,3,3-tetrafluoropropene;
1,2,3,3,3-pentafluoropropene; 1,1,1-trifluoropropene;
3,3,3-trifluoropropene; 1,1,1,3-tetrafluoropropene;
1,1,1,3,3-pentafluoropropene; 1,1,2,3,3-pentafluoropropene,
1,1,1,2-tetrafluoropropene; 1,1,1,2,3-pentafluoropropene,
1-chloro-3,3,3-trifluoropropene, 1,1,1,4,4,4-hexafluorobut-2-ene or
structural isomers, geometric isomers or stereoisomers thereof, or
combinations thereof.
5. The polyol premix composition of claim 1 wherein the
hydrohaloolefin comprises 1,3,3,3-tetrafluoropropene,
1-chloro-3,3,3-trifluoropropene, or stereoisomers thereof, or
combinations thereof.
6. The polyol premix composition of claim 1 wherein the blowing
agent comprises water, formic acid, organic acids that produce
CO.sub.2 when they react with an isocyanate, hydrocarbons; ethers,
esters, aldehydes, ketones, halogenated ethers; pentafluorobutane;
pentafluoropropane; hexafluoropropane; heptafluoropropane;
trans-1,2 dichloroethylene; methyl formate;
1-chloro-1,2,2,2-tetrafluoroethane; 1,1-dichloro-1-fluoroethane;
1,1,1,2-tetrafluoroethane; 1,1,1,2-tetrafluoroethane; 1-chloro
1,1-difluoroethane; 1,1,1,3,3-pentafluorobutane;
1,1,1,2,3,3,3-heptafluoropropane; trichlorofluoromethane;
dichlorodifluoromethane; 1,1,1,3,3,3-hexafluoropropane;
1,1,1,2,3,3-hexafluoropropane; difluoromethane; difluoroethane;
1,1,1,3,3-pentafluoropropane; 1,1-difluoroethane; isobutane; normal
pentane; isopentane; cyclopentane, or combinations thereof.
7. The polyol premix composition of claim 1 wherein the silicone
surfactant comprises a polysiloxane polyoxyalkylene block
co-polymer.
8. The polyol premix composition of claim 1 further comprising a
non-silicone, non-ionic surfactant.
9. The polyol premix composition of claim 1 wherein the polyol
comprises one or more of a sucrose containing polyol; phenol; a
phenol formaldehyde containing polyol; a glucose containing polyol;
a sorbitol containing polyol; a methylglucoside containing polyol;
an aromatic polyester polyol; glycerol; ethylene glycol; diethylene
glycol; propylene glycol; graft copolymers of polyether polyols
with a vinyl polymer; a copolymer of a polyether polyol with a
polyurea; one or more of (a) condensed with one or more of (b): (a)
glycerine, ethylene glycol, diethylene glycol, trimethylolpropane,
ethylene diamine, pentaerythritol, soy oil, lecithin, tall oil,
palm oil, castor oil; (b) ethylene oxide, propylene oxide, a
mixture of ethylene oxide and propylene oxide; or combinations
thereof.
10. The polyol premix composition of claim 1 wherein the sterically
hindered amine catalyst comprises a sterically hindered teriary
amine catalyst wherein each of R.sub.1, R.sub.2 and R.sub.3 are
independently C.sub.1 to C.sub.8 alkyl groups.
11. The polyol premix composition of claim 1 wherein the sterically
hindered amine catalyst comprises a sterically hindered secondary
amine catalyst wherein R.sub.1 and R.sub.2 are independently
C.sub.1 to C.sub.8 alkyl groups.
12. The polyol premix composition of claim 1 wherein the sterically
hindered amine catalyst comprises at least one a sterically
hindered teriary amine catalyst wherein each of R.sub.1, R.sub.2
and R.sub.3 are independently C.sub.1 to C.sub.8 alkyl groups, and
at least one sterically hindered secondary amine catalyst wherein
R.sub.1 and R.sub.2 are independently C.sub.1 to C.sub.8 alkyl
groups.
13. The polyol premix composition of claim 1 wherein the sterically
hindered teriary amine catalyst comprises cyclohexyldimethylamine;
dicyclohexylmethylamine; ethyldiisopropylamine;
dimethylcyclohexylamine; dimethylisopropylamine;
methylisopropylbenzylamine; methylcyclopentylbenzylamine;
isopropyl-sec-butyl-trifluoroethylamine;
diethyl-(.alpha.-phenylethyl)amine, tri-n-propylamine or
combinations thereof.
14. The polyol premix composition of claim 1 wherein the sterically
hindered secondary amine catalyst comprises; dicyclohexylamine;
t-butylisopropylamine; di-t-butylamine; cyclohexyl-t-butylamine;
di-sec-butylamine, dicyclopentylamine;
di-(.alpha.-trifluoromethylethyl)amine;
di-(.alpha.-phenylethyl)amine; or combinations thereof.
15. The polyol premix composition of claim 1 further comprising a
non-amine catalyst comprising an organometallic compound containing
bismuth, lead, tin, titanium, antimony, uranium, cadmium, cobalt,
thorium, aluminum, mercury, zinc, nickel, cerium, molybdenum,
vanadium, copper, manganese, zirconium, potassium, sodium, or
combinations thereof.
16. The polyol premix composition of claim 1 further comprising a
non-amine catalyst comprising bismuth nitrate, lead 2-ethylhexoate,
lead benzoate, ferric chloride, antimony trichloride, antimony
glycolate, stannous salts of carboxylic acids, zinc salts of
carboxylic acids, dialkyl tin salts of carboxylic acids, glycine
salts, tertiary amine trimerization catalysts, quaternary ammonium
carboxylates, alkali metal carboxylic acid salts, potassium
acetate, potassium octoate, potassium 2-ethylhexanoate,
N-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate, tin (II)
2-ethylhexanoate, dibutyltin dilaurate, or combinations
thereof.
17. A foamable composition comprising a mixture of an organic
polyisocyanate and the polyol premix composition of claim 1.
18. The foamable composition of claim 14 wherein the organic
polyisocyanate comprises a polymethylene polyphenyl isocyanate,
methylenebis(phenyl isocyanate), toluene diisocyanate, or
combinations thereof.
19. A method of preparing a polyurethane or polyisocyanurate foam
comprising reacting an organic polyisocyanate with the polyol
premix composition of claim 1.
20. A foam produced according to the method of claim 19.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a division of U.S. application Ser. No.
16/160,438, filed Oct. 15, 2018 (now pending), which is a division
of U.S. application Ser. No. 15/378,297 filed Dec. 14, 2016 (now
abandoned), which is a division of U.S. application Ser. No.
12/241,606, filed Sep. 30, 2008 (now U.S. Pat. No. 9,550,854,
issued Jan. 24, 2017) which application claims the benefit of
co-pending Provisional patent application Ser. No. 60/979,453 filed
Oct. 12, 2007, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention pertains to polyurethane and
polyisocyanurate foams and methods for the preparation thereof.
More particularly, the invention relates to rigid, polyurethane and
polyisocyanurate foams and methods for their preparation, which
foams are characterized by a fine uniform cell structure and little
or no foam collapse. The foams are produced with an organic
polyisocyanate and a polyol premix composition which comprises a
combination of a blowing agent, which is preferably a
hydrohaloolefin, a polyol, a silicone surfactant, and an amine
catalyst.
Description of the Related Art
[0003] The class of foams known as low density, rigid polyurethane
or polyisocyanurate foams has utility in a wide variety of
insulation applications including roofing systems, building panels,
building envelope insulation, refrigerators and freezers.
[0004] A critical factor in the large-scale commercial acceptance
of rigid polyurethane foams has been their ability to provide a
good balance of properties. Rigid polyurethane and polyisocyanurate
foams are known to provide outstanding thermal insulation,
excellent fire resistance properties, and superior structural
properties at reasonably low densities. The foam industry has
historically used liquid fluorocarbon blowing agents because of
their ease of use in processing conditions. Fluorocarbons not only
act as blowing agents by virtue of their volatility, but also are
encapsulated or entrained in the closed cell structure of the rigid
foam and are the major contributor to the low thermal conductivity
properties of the rigid urethane foams. The use of a fluorocarbon
as the preferred commercial expansion or blowing agent in
insulating foam applications is based in part on the resulting
k-factor associated with the foam produced. The k-factor is defined
as the rate of transfer of heat energy by conduction through one
square foot of one-inch thick homogenous material in one hour where
there is a difference of one degree Fahrenheit perpendicularly
across the two surfaces of the material. Since the utility of
closed-cell polyurethane-type foams is based, in part, on their
thermal insulation properties, it would be advantageous to identify
materials that produce lower k-factor foams.
[0005] It is known in the art to produce rigid polyurethane and
polyisocyanurate foams by reacting a polyisocyanate with a polyol
in the presence of a blowing agent, a catalyst, a surfactant, and
optionally other ingredients. Blowing agents include hydrocarbons,
fluorocarbons, chlorocarbons, fluorochlorocarbons, halogenated
hydrocarbons, ethers, esters, aldehydes, ketones, or CO.sub.2
generating materials. Heat generated when the polyisocyanate reacts
with the polyol volatilizes the blowing agent contained in the
liquid mixture, thereby forming bubbles therein. As the
polymerization reaction proceeds, the liquid mixture becomes a
cellular solid, entrapping the blowing agent in the foam's cells.
If a surfactant is not used in the foaming composition, the bubbles
simply pass through the liquid mixture without forming a foam or
forming a foam with large, irregular cells rendering it not useful.
Preferred blowing agents have low global warming potential. Among
these are hydrohaloolefins including hydrohaloolefins (HFOs) of
which trans-1,3,3,3-tetrafluoropropene (HFO-1234ze) is of
particular interest and hydrochlorofluoroolefins (HFCOs) of which
1-chloro-3,3,3-trifluoropropene (HFCO-1233zd) is of particular
interest. Processes for the manufacture of
1,3,3,3-tetrafluoropropene are disclosed in U.S. Pat. Nos.
7,230,146 and 7,189,884. Processes for the manufacture of
1-chloro-3,3,3-trifluoropropene are disclosed in U.S. Pat. Nos.
6,844,475 and 6,403,847.
[0006] It is convenient in many applications to provide the
components for polyurethane or polyisocyanurate foams in
pre-blended formulations. Most typically, the foam formulation is
pre-blended into two components. The polyisocyanate and optional
isocyanate compatible raw materials comprise the first component,
commonly referred to as the "A" component. A polyol or mixture of
polyols, surfactant, catalyst, blowing agent, and other isocyanate
reactive and non-reactive components comprise the second component,
commonly referred to as the "B" component. Accordingly,
polyurethane or polyisocyanurate foams are readily prepared by
bringing together the A and B side components either by hand mix
for small preparations and, preferably, machine mix techniques to
form blocks, slabs, laminates, pour-in-place panels and other
items, spray applied foams, froths, and the like. Optionally, other
ingredients such as fire retardants, colorants, auxiliary blowing
agents, and other polyols can be added to the mixing head or
reaction site. Most conveniently, however, they are all
incorporated into one B component.
[0007] A shortcoming of two-component systems, especially those
using certain hydrohaloolefins, including HFO-1234ze and
HFCO-1233zd is the shelf-life of the B-side composition. Normally
when a foam is produced by bringing together the A and B side
components, a good foam is obtained. However, if the polyol premix
composition is aged, prior to treatment with the polyisocyanate,
the foams are of lower quality and may even collapse during the
formation of the foam.
[0008] It has now been found that the origin of the problem is the
reaction of certain amine catalysts with certain hydrohaloolefins
including HFO-1234ze and HFCO-1233zd, resulting in partial
decomposition of the blowing agent. It has been found that,
subsequent to the decomposition of the blowing agent, the molecular
weight of the polymeric silicone surfactants, if present, is
detrimentally altered, leading to poor foam structure.
[0009] While it is possible to solve the problem by separating the
blowing agent, surfactant, and catalyst, for example by adding the
blowing agent, amine catalyst, or surfactant to the polyisocyanate,
("A" component) or by introducing the blowing agent, amine
catalyst, or surfactant using a separate stream from the "A" or "B"
component, a preferred solution is one that does not require
reformulation or a change in the way the foams are made.
[0010] It has now been found that sterically hindered amines have
lower reactivity toward certain blowing agents, such as
hydrohaloolefins including trans HFO-1234ze and HFCO-1233zd, such
that good quality foams can be produced even if the polyol blend
has been aged.
DESCRIPTION OF THE INVENTION
[0011] The invention provides a polyol premix composition which
comprises a combination of a blowing agent, a polyol, a silicone
surfactant, and a sterically hindered amine catalyst; wherein the
blowing agent comprises a hydrohaloolefin, and optionally a
hydrocarbon, fluorocarbon, chlorocarbon, fluorochlorocarbon,
halogenated hydrocarbon, CO.sub.2 generating material, or
combinations thereof; wherein the sterically hindered amine
catalyst has the formula R.sub.1R.sub.2N-[A-NR.sub.3].sub.nR.sub.4
wherein each of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is
independently H, a C.sub.1 to C.sub.8 alkyl group, a C.sub.1 to
C.sub.8 alkenyl group, a C.sub.1 to C.sub.8 alcohol group, or a
C.sub.1 to C.sub.8 ether group, or R.sub.1 and R.sub.2 together
form a C.sub.5 to C.sub.7 cyclic alkyl group, a C.sub.5 to C.sub.7
cyclic alkenyl group, a C.sub.5 to C.sub.7 heterocyclic alkyl
group, or a C.sub.5 to C.sub.7 heterocyclic alkenyl group; A is a
C.sub.1 to C.sub.5 alkyl group, a C.sub.1 to C.sub.5 alkenyl group,
or an ether; n is 0, 1, 2, or 3; with the proviso that the
sterically hindered amine catalyst has a sum of Charton's steric
parameters of about 1.65 or greater.
[0012] The invention also provides a method of preparing a
polyurethane or polyisocyanurate foam comprising reacting an
organic polyisocyanate with the polyol premix composition.
[0013] The blowing agent component comprises a hydrohaloolefin,
preferably comprising at least one of trans-HFO-1234ze and
HFCO-1233zd., and optionally a hydrocarbon, fluorocarbon,
chlorocarbon, fluorochlorocarbon, halogenated hydrocarbon, ether,
fluorinated ether, ester, aldehyde, ketone, CO.sub.2 generating
material, or combinations thereof.
[0014] The hydrohaloolefin preferably comprises at least one
halooalkene such as a fluoroalkene or chloroalkene containing from
3 to 4 carbon atoms and at least one carbon-carbon double bond.
Preferred hydrohaloolefins non-exclusively include
trifluoropropenes, tetrafluoropropenes such as (HFO-1234),
pentafluoropropenes such as (HFO-1225), chlorotrifloropropenes such
as (HFO-1233), chlorodifluoropropenes, chlorotrifluoropropenes,
chlorotetrafluoropropenes, and combinations of these. More
preferred that the compounds of the present invention are the
tetrafluoropropene, pentafluoropropene, and chlorotrifloropropene
compounds in which the unsaturated terminal carbon has not more
than one F or Cl substituent. Included are
1,3,3,3-tetrafluoropropene (HFO-1234ze);
1,1,3,3-tetrafluoropropene; 1,2,3,3,3-pentafluoropropene
(HFO-1225ye), 1,1,1-trifluoropropene; 1,1,1,3,3-pentafluoropropene
(HFO-1225zc); 1,1,1,3,3,3-hexafluorobut-2-ene;
1,1,2,3,3-pentafluoropropene (HFO-1225yc);
1,1,1,2,3-pentafluoropropene (HFO-1225yez);
1-chloro-3,3,3-trifluoropropene (HFCO-1233zd);
1,1,1,4,4,4-hexafluorobut-2-ene or combinations thereof, and any
and all structural isomers, geometric isomers or stereoisomers of
each of these.
[0015] Preferred hydrohaloolefins have a Global Warming Potential
(GWP) of not greater than 150, more preferably not greater than 100
and even more preferably not greater than 75. As used herein, "GWP"
is measured relative to that of carbon dioxide and over a 100-year
time horizon, as defined in "The Scientific Assessment of Ozone
Depletion, 2002, a report of the World Meteorological Association's
Global Ozone Research and Monitoring Project," which is
incorporated herein by reference. Preferred hydrohaloolefins also
preferably have an Ozone Depletion Potential (ODP) of not greater
than 0.05, more preferably not greater than 0.02 and even more
preferably about zero. As used herein, "ODP" is as defined in "The
Scientific Assessment of Ozone Depletion, 2002, A report of the
World Meteorological Association's Global Ozone Research and
Monitoring Project," which is incorporated herein by reference.
[0016] Preferred optional blowing agents non-exclusively include
water, formic acid, organic acids that produce CO.sub.2, when they
react with an isocyanate; hydrocarbons; ethers, halogenated ethers;
pentafluorobutane; pentafluoropropane; hexafluoropropane;
heptafluoropropane; trans-1,2 dichloroethylene; methyl formate;
1-chloro-1,2,2,2-tetrafluoroethane; 1,1-dichloro-1-fluoroethane;
1,1,1,2-tetrafluoroethane; 1,1,2,2-tetrafluoroethane; 1-chloro
1,1-difluoroethane; 1,1,1,3,3-pentafluorobutane;
1,1,1,2,3,3,3-heptafluoropropane; trichlorofluoromethane;
dichlorodifluoromethane; 1,1,1,3,3,3-hexafluoropropane;
1,1,1,2,3,3-hexafluoropropane; difluoromethane; difluoroethane;
1,1,1,3,3-pentafluoropropane; 1,1-difluoroethane; isobutane; normal
pentane; isopentane; cyclopentane, or combinations thereof. The
blowing agent component is usually present in the polyol premix
composition in an amount of from about 1 wt. % to about 30 wt. %,
preferably from about 3 wt. % to about 25 wt. %, and more
preferably from about 5 wt. % to about 25 wt. %, by weight of the
polyol premix composition. When both a hydrohaloolefin and an
optional blowing agent are present, the hydrohaloolefin component
is usually present in the blowing agent component in an amount of
from about 5 wt. % to about 90 wt. %, preferably from about 7 wt. %
to about 80 wt. %, and more preferably from about 10 wt. % to about
70 wt. %, by weight of the blowing agent component; and the
optional blowing agent is usually present in the blowing agent
component in an amount of from about 95 wt. % to about 10 wt. %,
preferably from about 93 wt. % to about 20 wt. %, and more
preferably from about 90 wt. % to about 30 wt. %, by weight of the
blowing agent component.
[0017] The polyol component, which includes mixtures of polyols,
can be any polyol which reacts in a known fashion with an
isocyanate in preparing a polyurethane or polyisocyanurate foam.
Useful polyols comprise one or more of a sucrose containing polyol;
phenol, a phenol formaldehyde containing polyol; a glucose
containing polyol; a sorbitol containing polyol; a methylglucoside
containing polyol; an aromatic polyester polyol; glycerol; ethylene
glycol; diethylene glycol; propylene glycol; graft copolymers of
polyether polyols with a vinyl polymer; a copolymer of a polyether
polyol with a polyurea; one or more of (a) condensed with one or
more of (b):
[0018] (a) glycerine, ethylene glycol, diethylene glycol,
trimethylolpropane, ethylene diamine, pentaerythritol, soy oil,
lecithin, tall oil, palm oil, castor oil;
[0019] (b) ethylene oxide, propylene oxide, a mixture of ethylene
oxide and propylene oxide; or combinations thereof. The polyol
component is usually present in the polyol premix composition in an
amount of from about 60 wt. % to about 95 wt. %, preferably from
about 65 wt. % to about 95 wt. %, and more preferably from about 70
wt. % to about 90 wt. %, by weight of the polyol premix
composition.
[0020] The polyol premix composition next contains a silicone
surfactant. The silicone surfactant is used to form a foam from the
mixture, as well as to control the size of the bubbles of the foam
so that a foam of a desired cell structure is obtained. Preferably,
a foam with small bubbles or cells therein of uniform size is
desired since it has the most desirable physical properties such as
compressive strength and thermal conductivity. Also, it is critical
to have a foam with stable cells which do not collapse prior to
forming or during foam rise.
[0021] Silicone surfactants for use in the preparation of
polyurethane or polyisocyanurate foams are available under a number
of trade names known to those skilled in this art. Such materials
have been found to be applicable over a wide range of formulations
allowing uniform cell formation and maximum gas entrapment to
achieve very low density foam structures. The preferred silicone
surfactant comprises a polysiloxane polyoxyalkylene block
co-polymer. Some representative silicone surfactants useful for
this invention are Momentive's L-5130, L-5180, L-5340, L-5440,
L-6100, L-6900, L-6980 and L-6988; Air Products DC-193, DC-197,
DC-5582, and DC-5598; and B-8404, B-8407, B-8409 and B-8462 from
Goldschmidt AG of Essen, Germany. Others are disclosed in U.S. Pat.
Nos. 2,834,748; 2,917,480; 2,846,458 and 4,147,847. The silicone
surfactant component is usually present in the polyol premix
composition in an amount of from about 0.5 wt. % to about 5.0 wt.
%, preferably from about 1.0 wt. % to about 4.0 wt. %, and more
preferably from about 1.5 wt. % to about 3.0 wt. %, by weight of
the polyol premix composition.
[0022] The polyol premix composition may optionally contain a
non-silicone, non-ionic surfactant. Such may include oxythylated
alkylphenols, oxyethylated fatty alcohols, paraffin oils, castor
oil esters, ricinoleic acid esters, turkey red oil, groundnut oil,
paraffins and fatty alcohols. A preferred non-silicone non-ionic
surfactant is LK-443 which is commercially available from Air
Products Corporation. When a non-silicone, non-ionic surfactant
used, it is usually present in the polyol premix composition in an
amount of from about 0.25 wt. % to about 3.0 wt. %, preferably from
about 0.5 wt. % to about 2.5 wt. %, and more preferably from about
0.75 wt. % to about 2.0 wt. %, by weight of the polyol premix
composition.
[0023] The inventive polyol premix composition next contains at
least one sterically hindered amine catalyst having the formula
R.sub.1R.sub.2N-[A-NR.sub.3].sub.nR.sub.4 wherein each of R.sub.1,
R.sub.2, R.sub.3, and R.sub.4 is independently H, a C.sub.1 to
C.sub.8 alkyl group, a C.sub.1 to C.sub.8 alkenyl group, a C.sub.1
to C.sub.8 alcohol group, or a C.sub.1 to C.sub.8 ether group, or
R.sub.1 and R.sub.2 together form a C.sub.5 to C.sub.7 cyclic alkyl
group, a C.sub.5 to C.sub.7 cyclic alkenyl group, a C.sub.5 to
C.sub.7 heterocyclic alkyl group, or a C.sub.5 to C.sub.7
heterocyclic alkenyl group; A is a C.sub.1 to C.sub.5 alkyl group,
a C.sub.1 to C.sub.5 alkenyl group, or an ether; n is 0, 1, 2, or
3; with the proviso that the sterically hindered amine catalyst has
a sum of Charton's steric parameters of about 1.65 or greater.
[0024] Charton's steric parameters for a group x are determined by:
comparing the rates of acid catalyzed hydrolysis of substituted
esters XCH.sub.2C(O)OR with the rate of the hydrolysis of the
corresponding unsubstituted ester. The differences correlate in
linear fashion with the Van der Waals radii of X (see R. W. Taft in
"Steric effects in organic chemistry," M. S. Newman, ed., Wiley,
New York, N.Y., 1956 p 556 and M. Charton, J. Am. Chem. Soc., 97
(1975) 1552), which are incorporated herein by reference. A list of
the values v can be found in M. Charton, J. Organic Chemistry, 41
(1976), 2217, which is incorporated herein by reference. Values for
selected groups are given in the following table.
TABLE-US-00001 GROUP .nu. H 0 Me 0.52 t-Bu 1.24 CCl.sub.3 1.38
CBr.sub.3 1.56 CI.sub.3 1.79 CF.sub.3 0.91 Me.sub.3Si 1.40 F 0.27
Cl 0.55 Br 0.65 I 0.78 Ph 1.66 Et 0.56 Pr 0.68 Bu 0.68 BuCH.sub.2
0.68 BuCH.sub.2CH.sub.2 0.73 Bu(CH.sub.2).sub.3 0.73
Bu(CH.sub.2).sub.4 0.68 i-PrCH.sub.2 0.98 t-BuCH.sub.2 1.34
s-BuCH.sub.2 1.00 i-PrCH.sub.2CH.sub.2 0.68 t-BuCH.sub.2CH.sub.2
0.70 t-BuCHEtCH.sub.2CH.sub.2 1.01 c-C.sub.6H.sub.11CH.sub.2 0.97
c-C.sub.6H.sub.11CH.sub.2CH.sub.2 0.70
c-C.sub.6H.sub.11(CH.sub.2).sub.3 0.71 i-Pr 0.76 s-Bu 1.02
Et.sub.2CH 1.51 Pr.sub.2CH 1.54 Bu.sub.2CH 1.56
(i-PrCH.sub.2).sub.2CH 1.70 (t-BuCH.sub.2).sub.2CH 2.03 i-PrCHEt
2.11 t-BuCHMe 2.11 t-BuCH.sub.2CHMe 1.41 c-C.sub.6H.sub.11 0.87
t-BuCMe.sub.2 2.43 t-BuCH.sub.2CMe.sub.2 1.74 Et.sub.3C 2.38
PhCH.sub.2 0.70 PhCH.sub.2CH.sub.2 0.70 Ph(CH.sub.2).sub.3 0.70
Ph(CH.sub.2).sub.4 0.70 PhMeCH 0.99 PhEtCH 1.18 Ph.sub.2CH 1.25
ClCH.sub.2 0.60 BrCH.sub.2 0.64 Cl.sub.2CH 0.81 Br.sub.2CH 0.89
Br.sub.2CMe 1.46 Me.sub.2CBr 1.39 CH.sub.2F 0.62 CH.sub.2I 0.67
CH.sub.2CN 0.89 CHI.sub.2 0.97 CHF.sub.2 0.68 c-C.sub.3H.sub.5 1.06
c-C.sub.4H.sub.7 0.51 c-C.sub.5H.sub.9 0.71 EtPrCH 1.51
n-C.sub.9H.sub.19 0.68 n-C.sub.11H.sub.22 0.68 n-C.sub.13H.sub.27
0.68 n-C.sub.15H.sub.31 0.68 n-C.sub.17H.sub.35 0.68
cis-H(CH.sub.2).sub.8CH.dbd.CH(CH.sub.2).sub.11 0.67
trans-H(CH.sub.2).sub.8CH.dbd.CH(CH.sub.2).sub.11 0.68
i-Pr(CH.sub.2).sub.3 0.68 MePrCH 1.05 Me(C.sub.2H.sub.3CH)CH 1.04
MeBuCH 1.07 Me(PhCH.sub.2)CH 0.98 Me-i-PrCH 1.29 Me-i-BuCH 1.09
EtBuCH 1.55 c-C.sub.7H.sub.13 1.00 MeOCH.sub.2 0.63 PrOCH.sub.2
0.65 i-PrOCH.sub.2 0.67 BuOCH.sub.2 0.66 i-BuOCH2 0.62
MeOCH.sub.2CH.sub.2 0.89 EtOCH.sub.2CH.sub.2 0.89
PrOCH.sub.2CH.sub.2 0.89 i-PrOCH.sub.2CH.sub.2 0.87
BuOCH.sub.2CH.sub.2 0.89 i-BuOCH.sub.2 CH.sub.2 0.89
MeO(CH.sub.2).sub.3 0.69 EtO(CH.sub.2).sub.3 0.69
PrO(CH.sub.2).sub.3 0.70 BuO(CH.sub.2).sub.3 0.71
9-Ethyl-9-fluorenyl 1.53 9-Isopropyl-9-fluorenyl 2.21
9-tert-Butyl-9-fluorenyl 2.63 9-Phenyl-9-fluorenyl 2.10
9-Butyl-9-fluorenyl 1.59 9-Benzyl-9-fluorenyl 1.63 9-OH-9-fluorenyl
0.98 9-Anthracenyl 1.18 10-Xanthyl 1.18 10-Thioxanthyl 1.42
C.sub.2H.sub.3Ph.sub.2CCH.sub.2 2.74 PhOCH.sub.2 0.74 EtOCH.sub.2
0.61 MeO(CH.sub.2).sub.4 0.68 EtO(CH.sub.2).sub.4 0.67
HOCH.sub.2CH.sub.2 0.77 MeSCH.sub.2 0.70 MeSCH.sub.2CH.sub.2 0.78
EtSCH.sub.2CH.sub.2 0.79 ICH.sub.2CH.sub.2 0.93 ClCH.sub.2CH.sub.2
0.97 MeOCH.sub.2CH.sub.2OCH.sub.2 0.57 EtOCH.sub.2CH.sub.2OCH.sub.2
0.56 PrOCH.sub.2CH.sub.2OCH.sub.2 0.56 BuOCH.sub.2CH.sub.2OCH.sub.2
0.55 MeO(CH.sub.2).sub.3OCH.sub.2 0.62 MeOCH.sub.2CH.sub.2OCHMe
0.67 MeOCH.sub.2CH.sub.2OCH.sub.2 CH.sub.2OCH.sub.2 0.56 CH.sub.2OH
0.53 MeCHOH 0.50 EtCHOH 0.71 PrCHOH 0.71 BuCHOH 0.70 BuCH.sub.2CHOH
0.71 EtC.dbd.O 0.79 PrC.dbd.O 0.80 EtCHOMe 1.22 PrCHOMe 1.22
BuCHOMe 1.20 C.sub.2H.sub.3 1.51 H.sub.2H.sub.3CH.sub.2 0.69
C.sub.2H.sub.3CH.sub.2CH.sub.2 0.75
C.sub.2H.sub.3CH.sub.2CH.sub.2CH.sub.2 0.75 Ph.sub.2CMe 2.34
Ph.sub.2CEt 2.75 Ph.sub.3C 2.92 9-Fluorenyl 1.08
9-Methyl-9-fluorenyl 1.41 EtSCH.sub.2 0.71 PhSCH.sub.2 0.82
(EtS).sub.2CH 1.39 EtSCHMe 1.10 2,5-Dithiacyclopentyl 0.89
2,6-Dithiacyclohexyl 1.16 t-BuOOCMe.sub.2 1.49
t-BuOCH.sub.2CMe.sub.2 1.30 t-BuCH.sub.2OCMe.sub.2 1.23
C.sub.2H.sub.3 1.31 CMe.dbd.CH.sub.2 1.56
C.sub.2H.sub.3CH.sub.2CH.sub.2 0.74
[0025] Useful sterically hindered amines include a sterically
hindered primary amine, secondary amine or tertiary amine. Useful
sterically hindered tertiary amine catalysts non-exclusively
include dicyclohexylmethylamine; ethyldiisopropylamine;
dimethylcyclohexylamine; dimethylisopropylamine;
methylisopropylbenzylamine; methylcyclopentylbenzylamine;
isopropyl-sec-butyl-trifluoroethylamine;
diethyl-(.alpha.-phenylethyl)amine, tri-n-propylamine, or
combinations thereof. Useful sterically hindered secondary amine
catalysts non-exclusively include dicyclohexylamine;
t-butylisopropylamine; di-t-butylamine; cyclohexyl-t-butylamine;
di-sec-butylamine, dicyclopentylamine;
di-(.alpha.-trifluoromethylethyl)amine;
di-(.alpha.-phenylethyl)amine; or combinations thereof. Useful
sterically hindered primary amine catalysts non-exclusively
include: triphenylmethylamine and 1,1-diethyl-n-propylamine.
[0026] Other useful sterically hindered amines includes
morpholines, imidazoles, ether containing compounds, and the like.
These include dimorpholinodiethylether
N-ethylmorpholine
N-methylmorpholine
[0027] bis(dimethylaminoethyl) ether imidizole n-methylimidazole
1,2-dimethylimidazole dimorpholinodimethylether
N,N,N',N',N'',N''-pentamethyldiethylenetriamine
N,N,N',N',N'',N''-pentaethyldiethylenetriamine
N,N,N',N',N'',N''-pentamethyldipropylenetriamine
bis(diethylaminoethyl) ether bis(dimethylaminopropyl) ether
[0028] The sterically hindered amine catalyst is usually present in
the polyol premix composition in an amount of from about 0.1 wt. %
to about 3.5 wt. %, preferably from about 0.2 wt. % to about 3.0
wt. %, and more preferably from about 0.5 wt. % to about 2.5 wt. %,
by weight of the polyol premix composition.
[0029] In another embodiment of the invention, the sterically
hindered amine component contains at least one of the aforesaid
sterically hindered tertiary amine catalysts and at least one of
the sterically hindered secondary amine catalysts.
[0030] The polyol premix composition may optionally further
comprise a non-amine catalyst. Suitable non-amine catalysts may
comprise an organometallic compound containing bismuth, lead, tin,
titanium, antimony, uranium, cadmium, cobalt, thorium, aluminum,
mercury, zinc, nickel, cerium, molybdenum, vanadium, copper,
manganese, zirconium, sodium, potassium, or combinations thereof.
These non-exclusively include bismuth nitrate, lead 2-ethylhexoate,
lead benzoate, ferric chloride, antimony trichloride, antimony
glycolate, stannous salts of carboxylic acids, zinc salts of
carboxylic acids, dialkyl tin salts of carboxylic acids, potassium
acetate, potassium octoate, potassium 2-ethylhexoate, glycine
salts, quaternary ammonium carboxylates, alkali metal carboxylic
acid salts, and
N-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate, tin (II)
2-ethylhexanoate, dibutyltin dilaurate, or combinations thereof.
When the optional non-amine catalyst is used, it is usually present
in the polyol premix composition in an amount of from about 0.01
wt. % to about 2.5 wt. %, preferably from about 0.05 wt. % to about
2.25 wt. %, and more preferably from about 0.10 wt. % to about 2.00
wt. %. by weight of the polyol premix composition. While these are
usual amounts, the quantity amount of metallic catalyst can vary
widely, and the appropriate amount can be easily determined by
those skilled in the art. The preparation of polyurethane or
polyisocyanurate foams using the compositions described herein may
follow any of the methods well known in the art can be employed,
see Saunders and Frisch, Volumes I and II Polyurethanes Chemistry
and technology, 1962, John Wiley and Sons, New York, N.Y. or Gum,
Reese, Ulrich, Reaction Polymers, 1992, Oxford University Press,
New York, N.Y. or Klempner and Sendijarevic, Polymeric Foams and
Foam Technology, 2004, Hanser Gardner Publications, Cincinnati,
Ohio In general, polyurethane or polyisocyanurate foams are
prepared by combining an isocyanate, the polyol premix composition,
and other materials such as optional flame retardants, colorants,
or other additives. These foams can be rigid, flexible, or
semi-rigid, and can have a closed cell structure, an open cell
structure or a mixture of open and closed cells.
[0031] It is convenient in many applications to provide the
components for polyurethane or polyisocyanurate foams in
pre-blended formulations. Most typically, the foam formulation is
pre-blended into two components. The isocyanate and optionally
other isocyanate compatible raw materials comprise the first
component, commonly referred to as the "A" component. The polyol
mixture composition, including surfactant, catalysts, blowing
agents, and optional other ingredients comprise the second
component, commonly referred to as the "B" component. In any given
application, the "B" component may not contain all the above listed
components, for example some formulations omit the flame retardant
if flame retardancy is not a required foam property. Accordingly,
polyurethane or polyisocyanurate foams are readily prepared by
bringing together the A and B side components either by hand mix
for small preparations and, preferably, machine mix techniques to
form blocks, slabs, laminates, pour-in-place panels and other
items, spray applied foams, froths, and the like. Optionally, other
ingredients such as fire retardants, colorants, auxiliary blowing
agents, water, and even other polyols can be added as a stream to
the mix head or reaction site. Most conveniently, however, they are
all incorporated into one B component as described above.
[0032] A foamable composition suitable for forming a polyurethane
or polyisocyanurate foam may be formed by reacting an organic
polyisocyanate and the polyol premix composition described above.
Any organic polyisocyanate can be employed in polyurethane or
polyisocyanurate foam synthesis inclusive of aliphatic and aromatic
polyisocyanates. Suitable organic polyisocyanates include
aliphatic, cycloaliphatic, araliphatic, aromatic, and heterocyclic
isocyanates which are well known in the field of polyurethane
chemistry. These are described in, for example, U.S. Pat. Nos.
4,868,224; 3,401,190; 3,454,606; 3,277,138; 3,492,330; 3,001,973;
3,394,164; 3,124.605; and 3,201,372. Preferred as a class are the
aromatic polyisocyanates.
[0033] Representative organic polyisocyanates correspond to the
formula:
R(NCO)z
[0034] wherein R is a polyvalent organic radical which is either
aliphatic, aralkyl, aromatic or mixtures thereof, and z is an
integer which corresponds to the valence of R and is at least two.
Representative of the organic polyisocyanates contemplated herein
includes, for example, the aromatic diisocyanates such as
2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixtures of
2,4- and 2,6-toluene diisocyanate, crude toluene diisocyanate,
methylene diphenyl diisocyanate, crude methylene diphenyl
diisocyanate and the like; the aromatic triisocyanates such as
4,4',4''-triphenylmethane triisocyanate, 2,4,6-toluene
triisocyanates; the aromatic tetraisocyanates such as
4,4'-dimethyldiphenylmethane-2,2'5,5-'tetraisocyanate, and the
like; arylalkyl polyisocyanates such as xylylene diisocyanate;
aliphatic polyisocyanate such as hexamethylene-1,6-diisocyanate,
lysine diisocyanate methylester and the like; and mixtures thereof.
Other organic polyisocyanates include polymethylene
polyphenylisocyanate, hydrogenated methylene diphenylisocyanate,
m-phenylene diisocyanate, naphthylene-1,5-diisocyanate,
1-methoxyphenylene-2,4-diisocyanate, 4,4'-biphenylene diisocyanate,
3,3'-dimethoxy-4,4'-biphenyl diisocyanate,
3,3'-dimethyl-4,4'-biphenyl diisocyanate, and
3,3'-dimethyldiphenylmethane-4,4'-diisocyanate; Typical aliphatic
polyisocyanates are alkylene diisocyanates such as trimethylene
diisocyanate, tetramethylene diisocyanate, and hexamethylene
diisocyanate, isophorene diisocyanate, 4,
4'-methylenebis(cyclohexyl isocyanate), and the like; typical
aromatic polyisocyanates include m-, and p-phenylene disocyanate,
polymethylene polyphenyl isocyanate, 2,4- and
2,6-toluenediisocyanate, dianisidine diisocyanate, bitoylene
isocyanate, naphthylene 1,4-diisocyanate,
bis(4-isocyanatophenyl)methene,
bis(2-methyl-4-isocyanatophenyl)methane, and the like. Preferred
polyisocyanates are the polymethylene polyphenyl isocyanates,
Particularly the mixtures containing from about 30 to about 85
percent by weight of methylenebis(phenyl isocyanate) with the
remainder of the mixture comprising the polymethylene polyphenyl
polyisocyanates of functionality higher than 2. These
polyisocyanates are prepared by conventional methods known in the
art. In the present invention, the polyisocyanate and the polyol
are employed in amounts which will yield an NCO/OH stoichiometric
ratio in a range of from about 0.9 to about 5.0. In the present
invention, the NCO/OH equivalent ratio is, preferably, about 1.0 or
more and about 3.0 or less, with the ideal range being from about
1.1 to about 2.5. Especially suitable organic polyisocyanate
include polymethylene polyphenyl isocyanate, methylenebis(phenyl
isocyanate), toluene diisocyanates, or combinations thereof. In the
preparation of polyisocyanurate foams, trimerization catalysts are
used for the purpose of converting the blends in conjunction with
excess A component to polyisocyanurate-polyurethane foams. The
trimerization catalysts employed can be any catalyst known to one
skilled in the art, including, but not limited to, glycine salts,
tertiary amine trimerization catalysts, quaternary ammonium
carboxylates, and alkali metal carboxylic acid salts and mixtures
of the various types of catalysts. Preferred species within the
classes are potassium acetate, potassium octoate, and
N-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate.
[0035] Conventional flame retardants can also be incorporated,
preferably in amount of not more than about 20 percent by weight of
the reactants. Optional flame retardants include
tris(2-chloroethyl)phosphate, tris(2-chloropropyl)phosphate,
tris(2,3-dibromopropyl)phosphate,
tris(1,3-dichloropropyl)phosphate, tri(2-chloroisopropyl)phosphate,
tricresyl phosphate, tri(2,2-dichloroisopropyl)phosphate, diethyl
N,N-bis(2-hydroxyethyl) aminomethylphosphonate, dimethyl
methylphosphonate, tri(2,3-dibromopropyl)phosphate,
tri(1,3-dichloropropyl)phosphate, and
tetra-kis-(2-chloroethyl)ethylene diphosphate, triethylphosphate,
diammonium phosphate, various halogenated aromatic compounds,
antimony oxide, aluminum trihydrate, polyvinyl chloride, melamine,
and the like. Other optional ingredients can include from 0 to
about 7 percent water, which chemically reacts with the isocyanate
to produce carbon dioxide. This carbon dioxide acts as an auxiliary
blowing agent. Formic acid is also used to produce carbon dioxide
by reacting with the isocyanate and is optionally added to the "B"
component. In addition to the previously described ingredients,
other ingredients such as, dyes, fillers, pigments and the like can
be included in the preparation of the foams. Dispersing agents and
cell stabilizers can be incorporated into the present blends.
Conventional fillers for use herein include, for example, aluminum
silicate, calcium silicate, magnesium silicate, calcium carbonate,
barium sulfate, calcium sulfate, glass fibers, carbon black and
silica. The filler, if used, is normally present in an amount by
weight ranging from about 5 parts to 100 parts per 100 parts of
polyol. A pigment which can be used herein can be any conventional
pigment such as titanium dioxide, zinc oxide, iron oxide, antimony
oxide, chrome green, chrome yellow, iron blue siennas, molybdate
oranges and organic pigments such as para reds, benzidine yellow,
toluidine red, toners and phthalocyanines.
[0036] The polyurethane or polyisocyanurate foams produced can vary
in density from about 0.5 pounds per cubic foot to about 60 pounds
per cubic foot, preferably from about 1.0 to 20.0 pounds per cubic
foot, and most preferably from about 1.5 to 6.0 pounds per cubic
foot. The density obtained is a function of how much of the blowing
agent or blowing agent mixture disclosed in this invention plus the
amount of auxiliary blowing agent, such as water or other
co-blowing agents is present in the A and/or B components, or
alternatively added at the time the foam is prepared. These foams
can be rigid, flexible, or semi-rigid foams, and can have a closed
cell structure, an open cell structure or a mixture of open and
closed cells. These foams are used in a variety of well known
applications, including but not limited to thermal insulation,
cushioning, flotation, packaging, adhesives, void filling, crafts
and decorative, and shock absorption.
[0037] The following non-limiting examples serve to illustrate the
invention.
Example 1 (Comparative)
[0038] In this example the reaction of a the tertiary amine
catalyst, pentamethyldiethylenetriamine (Polycat 5), and
trans-1,3,3,3-tetrafluoropropene (HFO-1234ze) was investigated by
heating the two together in a glass pressure reactor for 2 days at
120.degree. F. Over the 2-day period, the physical state of the
liquid phase was monitored as well as the total system pressure. At
the end of the experiment, the liquid phase was analyzed for
fluoride ion. In this example, the pressure decreased 44% after one
day and 65% after 2 days. After the first day, an orange solid was
present. Analysis of the liquid using ion chromatography indicated
>5 weight % fluoride ion (>50,000 ppm).
Examples 2-5 (Comparative)
[0039] In these examples, other amines were evaluated similarly at
120.degree. F. for 3 days using approximately equimolar amounts of
amine and trans-1,3,3,3-tetrafluoropropene. The amine, pressure
drop (%), physical change, and fluoride found are given.
[0040] 1,8-Diazabicyclo[5.4.0]undecene-7, 80%, red-orange solid,
>5 weight %; 1,4-diazabicyclooctane in dipropylene glycol (DABCO
33-LV.RTM.), 25%, orange viscous liquid, >5 weight %;
N-methylcyclohexylamine, 86%, white precipitate followed by orange
liquid, >5 weight %; N-isopropylmethylamine, 78%; orange
solution; >5 weight %. The drop in pressure during the test, the
presence of solid, and the change in color are all indications of
reaction between the amine and olefin. The % fluoride ion in the
residue is a quantitative measurement of the extent of reaction.
Greater than 5 wt % fluoride is unacceptably high and represents
extensive decomposition of the olefin.
Examples 6-8 (Comparative)
[0041] These amines were treated with
trans-1,3,3,3-tetrafluoropropene at room temperature (77-78 F) for
3 days. N-methylcyclohexylamine, 48%, yellow-orange solid, 5 wt
%;
[0042] Di-n-propylamine, 56%, precipitate in 30 minutes; >5 wt
%; Isopropylamine, 45%, solid in 5 minutes, >5 wt %. In these
examples, decomposition of the olefin was still extensive, even at
room temperature.
Example 9 (Comparative)
[0043] A polyol (B Component) formulation was made up of 100 parts
by weight of a polyol blend, 1.5 parts by weight Niax L6900
silicone surfactant, 3 parts by weight water, 8 parts by weight
triethyl phosphate flame retardant, 1 part by weight N, N, N', N'',
N'' pentamethyldiethylenetriamine (sold as Polycat 5 by Air
Products) catalyst and 8 parts by weight
trans-1,3,3,3-tetrafluoropropene blowing agent. The total B
component composition, when freshly prepared and combined with
217.3 parts by weight of Lupranate M20S polymeric isocyanate
yielded a good quality foam with a fine and regular cell structure.
Foam reactivity was typical for a pour in place foam with a gel
time of 80 seconds. The total B component composition (121.5 parts)
was then aged at 120.degree. F. for 62 hours, and then combined
with 217.3 parts of M20S Iso polyisocyanate to make a foam. The
foam collapsed during formation. Due to the foam collapse, no get
time could be determined. The polyol formulation turned yellow
during aging. This result shows that 5 wt % fluoride, as found in
the screening test of Example 1, represented sufficient
decomposition to result in foam collapse.
Example 10-17
[0044] The following amines were heated 3 days at 120 F with
trans-1,3,3,3-tetrafluoropropene (trans-HFO-1234ze) using
approximately equimolar amounts of amine and HFO-1234ze. The amine
and fluoride found are given. Dimethylcyclohexylamine (Polycat 8),
1970 ppm; diisopropylamine, 7650 ppm; dicyclohexylmethylamine
(Polycat 12), 480 ppm; diisopropylethylamine, 67 ppm;
dicyclohexylamine, 942 ppm; di-sec-butylamine, 203 ppm;
t-butylisopropylamine, 237 ppm; dimethylisopropylamine, 3474 ppm.
Using these amines, the amount of fluoride produced (and therefore
the amount of olefin decomposition) in the three-day test was much
less than that in the comparative examples. The amount of fluoride
produced generally decreased with increasingly hindered amines.
Example 18 (Foam Tests)
[0045] A polyol (B Component) formulation was made up of 100 parts
by weight of a polyol blend, 1.5 parts by weight Niax L6900
silicone surfactant, 3 parts by weight water, 8 parts by weight
triethyl phosphate flame retardant, 0.7 parts by weight
N,N-dimethylcyclohexylamine (sold as Polycat 8 by Air Products)
catalyst and 8 parts by weight trans1,3,3,3-tetrafluoropropene
blowing agent. The total B component composition, when freshly
prepared and combined with 217.3 parts by weight of Lupranate M20S
polymeric isocyanate yielded a good quality foam with a fine and
regular cell structure. Foam reactivity was typical of a slow
reacting pour in place foam with a gel time of 285 seconds. The
total B-side composition (119.7 parts) was then aged at 120.degree.
F. for 62 hours, and then combined with 217.3 parts of M20S Iso
polyisocyanate to make a foam. The foam was normal in appearance
without cell collapse. Gel time was 300 seconds. No discoloration
was noted during aging. This test confirmed the screening test of
example 10, that is, the low fluoride produced in the test
successfully predicted that good foam could be made with this
amine, even after aging.
Example 19 (Comparative)
[0046] A polyol (B Component) formulation was made up of 100 parts
by weight of a polyol blend, 1.5 parts by weight Niax L6900
silicone surfactant, 1.5 parts by weight water, 1.2 part by weight
N, N, N', N'', N'' pentamethyldiethylenetriamine (sold as Polycat 5
by Air Products) catalyst and 8 parts by weight
trans-1,3,3,3-tetrafluoropropene blowing agent. The total B
component composition, when freshly prepared and combined with
120.0 parts by weight of Lupranate M20S polymeric isocyanate
yielded a good quality foam with a fine and regular cell structure.
Foam reactivity was typical for a pour in place foam with a gel
time of 78 seconds. The total B-side composition (112.2 parts) was
then aged at 120.degree. F. for 62 hours, and then combined with
120.0 parts of M20S Iso polyisocyanate to make a foam. The foam
collapsed during formation. Due to the foam collapse, no get time
could be determined. The polyol formulation turned yellow during
aging.
Example 20 (Foam Tests)
[0047] A polyol (B Component) formulation was made up of 100 parts
by weight of a polyol blend, 1.5 parts by weight Niax L6900
silicone surfactant, 1.5 parts by weight water, 8.0 part by weight
diisopropylethylamine catalyst and 8 parts by weight
trans-1,3,3,3-tetrafluoropropene blowing agent. The total B
component composition, when freshly prepared and combined with
120.0 parts by weight of Lupranate M20S polymeric isocyanate
yielded a good quality foam with a fine and regular cell structure.
Foam reactivity was typical for a pour in place foam with a gel
time of 187 seconds. The total B-side composition (119.0 parts) was
then aged at 120.degree. F. for 62 hours, and then combined with
120.0 parts of M20S Iso polyisocyanate to make a foam. The foam was
normal in appearance without cell collapse. Gel time was 190
seconds. No discoloration was noted during aging.
Example 21 (Foam Tests)
[0048] A polyol (B Component) formulation was made up of 100 parts
by weight of a polyol blend, 1.5 parts by weight Niax L6900
silicone surfactant, 1.5 parts by weight water, 8.0 part by weight
dicyclohexylmethylamine (sold as Polycat 12 by Air Products and
Chemicals) catalyst and 8 parts by weight
trans-1,3,3,3-tetrafluoropropene blowing agent. The total B
component composition, when freshly prepared and combined with
120.0 parts by weight of Lupranate M20S polymeric isocyanate
yielded a good quality foam with a fine and regular cell structure.
Foam reactivity was typical for a pour in place foam with a gel
time of 150 seconds. The total B-side composition (115.0 parts) was
then aged at 120.degree. F. for 62 hours, and then combined with
120.0 parts of M20S Iso polyisocyanate to make a foam. The foam was
normal in appearance without cell collapse. Gel time was 136
seconds. No discoloration was noted during aging.
[0049] These examples show that the use of non-sterically hindered
amines as catalysts produce polyol premixes that are not stable
over time as evidenced by cell coalescence and foam collapse. When
sterically hindered tertiary amines are substituted for the
non-sterically hindered amines, this instability is not observed
and good quality foam is produced using both fresh and aged polyol
premixes ("B" components).
[0050] While the present invention has been particularly shown and
described with reference to preferred embodiments, it will be
readily appreciated by those of ordinary skill in the art that
various changes and modifications may be made without departing
from the spirit and scope of the invention. It is intended that the
claims be interpreted to cover the disclosed embodiment, those
alternatives which have been discussed above and all equivalents
thereto.
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