N,N,N'-trimethylbis (Aminoethyl) ether substituted urea compostions for the production of polyurethanes

A method for preparing a polyurethane foam which comprises reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a cell stabilizer and a catalyst composition consisting essentially of the compound represented by the following formula I or II, or any blend of I and II. ##STR1##

BACKGROUND OF THE INVENTION 
The present invention relates to the use of tertiary amine catalysts for 
producing polyurethanes, especially polyurethane foam. 
Polyurethane foams are widely known and used in automotive, housing and 
other industries. Such foams are produced by reaction of a polyisocyanate 
with a polyol in the presence of various additives. One such additive is a 
chlorofluorocarbon (CFC) blowing agent which vaporizes as a result of the 
reaction exotherm, causing the polymerizing mass to form a foam. The 
discovery that CFCs deplete ozone in the stratosphere has resulted in 
mandates diminishing CFC use. Production of water-blown foams, in which 
blowing is performed with CO.sub.2 generated by the reaction of water with 
the polyisocyanate, has therefore become increasingly important. Tertiary 
amine catalysts are typically used to accelerate blowing (reaction of 
water with isocyanate to generate CO.sub.2) and gelling (reaction of 
polyol with isocyanate). 
The ability of the tertiary amine catalyst to selectively promote either 
blowing or gelling is an important consideration in selecting a catalyst 
for the production of a particular polyurethane foam. If a catalyst 
promotes the blowing reaction to a too high degree, much of the CO.sub.2 
will be evolved before sufficient reaction of isocyanate with polyol has 
occurred, and the CO.sub.2 will bubble out of the formulation, resulting 
in collapse of the foam. A foam of poor quality will be produced. On the 
other hand, if a catalyst too strongly promotes the gelling reaction, a 
substantial portion of the CO.sub.2 will be evolved after a significant 
degree of polymerization has occurred. Again, a poor quality foam, this 
time characterized by high density, broken or poorly defined cells, or 
other undesirable features, will be produced. 
Tertiary amine catalysts generally are malodorous and offensive and many 
have high volatility due to low molecular weight. Release of tertiary 
amines during foam processing may present significant safety and toxicity 
problems, and release of residual amines from consumer products is 
generally undesirable. 
Amine catalysts which contain ureido functionality (e.g., CONH.sub.2) have 
an increase in molecular weight and hydrogen bonding and reduced 
volatility and odor when compared to related structures which lack this 
functionality. Furthermore, catalysts which contain ureido functionality 
chemically bond into the urethane during the reaction and are not released 
from the finished product. Catalyst structures which embody this concept 
are typically of low to moderate activity and promote both the blowing 
(water-isocyanate) and the gelling (polyol-isocyanate) reactions to 
varying extents. 
U.S. Pat. No. 4,644,017 discloses the use of certain diffusion stable amino 
alkyl ureas having tertiary amino groups in the production of a 
polyisocyanate addition product which do not discolor or change the 
constitution of surrounding materials such as PVC. 
U.S. Pat. No. 4,007,140 discloses the use of 
N,N'-bis(3-dimethylaminopropyl)urea as a low odor catalyst for the 
manufacture of polyurethanes. 
U.S. Pat. No. 4,194,069 discloses the use of 
N-(3-dimethylaminopropyl)-N'-(3-morpholinopropyl)urea, 
N,N'-bis(3-dimethylaminopropyl)urea and N,N'-bis(3-morpholinopropyl)urea 
as catalysts for producing polyurethanes. 
U.S. Pat. No. 4,094,827 discloses the use of certain alkyl substituted 
ureas which provide lower odor and a delay in the foaming reaction that 
aids in the production of polyurethane foam. 
U.S. Pat. No. 4,330,656 discloses the use of N-alkyl ureas as catalysts for 
the reaction of 1,5-napthylene diisocyanate with polyols or for the chain 
extension of prepolymers based upon 1,5-napthylene diisocyanate without 
accelerating atmospheric oxidation. 
DE 30 27 796 A1 discloses the use of higher molecular weight dialkyl 
aminoalkyl ureas as reduced odor catalysts for the production of 
polyurethane foam. 
SUMMARY OF THE INVENTION 
The present invention provides a composition for catalyzing the 
trimerization of an isocyanate and/or the reaction between an isocyanate 
and a compound containing a reactive hydrogen, e.g., the blowing reaction 
and the urethane reaction for making polyurethane. The catalyst 
composition comprises an N,N,N'-trimethylbis(aminoethyl)-ether substituted 
urea represented by formula I or II: 
##STR2## 
The catalyst composition may comprise compound I, compound II, or a blend 
of compounds I and II in any weight ratio. 
The advantage of these catalyst compounds is their high activity and 
blowing selectivity. Additionally, they contain a ureido group which will 
react with isocyanate and chemically bond into the urethane during the 
reaction; therefore, the catalyst composition is not released from the 
finished product. The compositions are somewhat viscous and have minimal 
odor.

DETAILED DESCRIPTION OF THE INVENTION 
The catalyst compositions according to the invention can catalyze (1) the 
reaction between an isocyanate functionality and an active 
hydrogen-containing compound, i.e. an alcohol, a polyol, an amine or 
water, especially the urethane (gelling) reaction of polyol hydroxyls with 
isocyanate to make polyurethanes and the blowing reaction of water with 
isocyanate to release carbon dioxide for making foamed polyurethanes, 
and/or (2) the trimerization of the isocyanate functionality to form 
polyisocyanurates. 
The polyurethane products are prepared using any suitable organic 
polyisocyanates well known in the art including, for example, 
hexamethylene diisocyanate, phenylene diisocyanate, toluene diisocyanate 
("TDI") and 4,4'-diphenylmethane diisocyanate ("MDI"). Especially suitable 
are the 2,4- and 2,6-TDI's individually or together as their commercially 
available mixtures. Other suitable isocyanates are mixtures of 
diisocyanates known commercially as "crude MDI", also known as PAPI, which 
contain about 60% of 4,4'-diphenylmethane diisocyanate along with other 
isomeric and analogous higher polyisocyanates. Also suitable are 
"prepolymers" of these polyisocyanates comprising a partially prereacted 
mixture of a polyisocyanate and a polyether or polyester polyol. 
Illustrative of suitable polyols as a component of the polyurethane 
composition are the polyalkylene ether and polyester polyols. The 
polyalkylene ether polyols include the poly(alkylene oxide) polymers such 
as poly(ethylene oxide) and poly(propylene oxide) polymers and copolymers 
with terminal hydroxyl groups derived from polyhydric compounds, including 
diols and triols; for example, among others, ethylene glycol, propylene 
glycol, 1,3-butane diol, 1,4-butane diol, 1,6-hexane diol, neopentyl 
glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, 
diglycerol, trimethylol propane and like low molecular weight polyols. 
In the practice of this invention, a single high molecular weight polyether 
polyol may be used. Also, mixtures of high molecular weight polyether 
polyols such as mixtures of di- and trifunctional materials and/or 
different molecular weight or different chemical composition materials may 
be used. 
Useful polyester polyols include those produced by reacting a dicarboxylic 
acid with an excess of a diol, for example, adipic acid with ethylene 
glycol or butanediol, or reacting a lactone with an excess of a diol such 
as caprolactone with propylene glycol. 
In addition to the polyether and polyester polyols, the masterbatches, or 
premix compositions, frequently contain a polymer polyol. Polymer polyols 
are used in polyurethane foam to increase the foam's resistance to 
deformation, i.e. to increase the load-bearing properties of the foam. 
Currently, two different types of polymer polyols are used to achieve 
load-bearing improvement. The first type, described as a graft polyol, 
consists of a triol in which vinyl monomers are graft copolymerized. 
Styrene and acrylonitrile are the usual monomers of choice. The second 
type, a polyurea modified polyol, is a polyol containing a polyurea 
dispersion formed by the reaction of a diamine and TDI. Since TDI is used 
in excess, some of the TDI may react with both the polyol and polyurea. 
This second type of polymer polyol has a variant called PIPA polyol which 
is formed by the in-situ polymerization of TDI and alkanolamine in the 
polyol. Depending on the load-bearing requirements, polymer polyols may 
comprise 20-80% of the polyol portion of the masterbatch. 
Other typical agents found in the polyurethane foam formulations include 
chain extenders such as ethylene glycol and butanediol; crosslinkers such 
as diethanolamine, diisopropanolamine, triethanolamine and 
tripropanolamine; blowing agents such as water, CFCs, HCFCs, HFCs, 
pentane, and the like; and cell stabilizers such as silicones. 
A general polyurethane flexible foam formulation having a 1-3 lb/ft.sup.3 
(16-48 kg/m.sup.3) density (e.g., automotive seating) containing a gelling 
catalyst such as triethylenediamine (TEDA) and a blowing catalyst such as 
the catalyst composition according to the invention would comprise the 
following components in parts by weight (pbw): 
______________________________________ 
Flexible Foam Formulation 
pbw 
______________________________________ 
Polyol 20-100 
Polymer Polyol 80-0 
Silicone Surfactant 
1-2.5 
Blowing Agent 2-4.5 
Crosslinker 0.5-2 
Catalyst 0.2-2 
Isocyanate Index 70-115 
______________________________________ 
Any gelling catalyst known in the polyurethane art may be used with the 
catalyst compounds of the invention. Illustrative of suitable gelling 
catalysts are TEDA and tin urethane catalysts. 
The blowing catalyst composition comprises the compounds represented by the 
following formulas I and II, and any wt % combination of compounds I and 
II. Mixtures of compounds I and II may comprise 50 to 95 wt % compound I 
and 5 to 50 wt % compound II. As a result of the preparation procedure the 
catalyst composition may also contain up to 20 wt % unreacted urea III. 
##STR3## 
Compounds I and II are prepared by reacting urea and 
4,10-diaza-4,10,10-trimethyl-7-oxa-undecanamine in the appropriate molar 
ratios under an inert atmosphere at elevated temperatures. Compounds I and 
II can be isolated individually by chromatography. 
A catalytically effective amount of the catalyst composition is used in the 
polyurethane formulation. More specifically, suitable amounts of the 
catalyst composition may range from about 0.01 to 10 parts by wt per 100 
parts polyol (phpp) in the polyurethane formulation, preferably 0.05 to 
0.5 phpp. 
The catalyst composition may be used in combination with, or also comprise, 
other tertiary amine, organotin or carboxylate urethane catalysts (gelling 
and/or blowing) well known in the urethane art. 
EXAMPLE 1 
Blend of 4,10-Diaza-4,10,10-trimethyl-7-oxa-undecane urea and 
N,N'-Bis-(4,10-diaza-4,10,10-trimethyl-7-oxa-undecane)urea 
A one liter 3 neck round bottom flask was fitted with the following: 
mechanical stirrer, reflux condenser, nitrogen sparger, and a temperature 
controlled heating mantle. The flask was charged with 138.31 g of urea 
(CH.sub.4 N.sub.2 O) and 467.49 g of 
4,10-diaza-4,10,10-trimethyl-7-oxa-undecanamine (IV) (C.sub.10 H.sub.25 
N.sub.3 O). (Compound IV can be prepared according to following Examples 
5-7.) 
##STR4## 
The mixture was stirred at a constant rate while being slowly heated to 
120.degree. C. The reaction was controlled at 120.degree. C. until all 
signs of NH.sub.3 evolution had ceased (as evidenced by bubbling in the 
N.sub.2 pressure relief device). The pale yellow liquid was cooled to 
80.degree. C. and the flask containing the liquid was evacuated via vacuum 
pump and refilled with N.sub.2 three time to remove any volatiles still 
present. Table 1 presents quantitative .sup.13 C NMR analysis of the 
reaction. 
TABLE 1 
______________________________________ 
Reaction Product Example 1 mole % 
______________________________________ 
4,10-Diaza-4,10,10-trimethyl-7-oxa-undecane urea 
85.27 
N,N'-Bis-(4,10-diaza-4,10,10-trimethyl-7-oxa-undecane) urea 
4.65 
Urea 10.08 
______________________________________ 
EXAMPLE 2 
4,10-Diaza-4,10,10-trimethyl-7-oxa-undecane urea 
The mixture from Example 1 was dissolved in ether and filtered through 
silica gel. The silica gel was washed with methanol and the extract was 
concentrated using a rotary evaporator. Quantitative .sup.13 C NMR 
analysis of the methanol extract is shown in Table 
TABLE 2 
______________________________________ 
Reaction Product Example 2 mole % 
______________________________________ 
4,10-Diaza-4,10,10-trimethyl-7-oxa-undecane urea 
89.32 
N,N'-Bis-(4,10-diaza-4,10,10-trimethyl-7-oxa-undecane) urea 
2.91 
Urea 7.77 
______________________________________ 
EXAMPLE 3 
N,N'-Bis-(4,10-diaza-4,10,10-trimethyl-7-oxa-undecane)urea 
A one liter 3 neck round bottom flask was fitted with the following: 
mechanical stirrer, reflux condenser, nitrogen sparger, and a temperature 
controlled heating mantle. The flask was charged with 8.88 g of urea 
(CH.sub.4 N.sub.2 O) and 63.03 g of 
4,10-diaza-4,10,10-trimethyl-7-oxa-undecanamine (IV) (C.sub.10 H.sub.25 
N.sub.3 O). The mixture was stirred at a constant rate while being slowly 
heated to 120.degree. C. The reaction was controlled at 120.degree. C. 
until all signs of NH.sub.3 evolution had ceased (as evidenced by bubbling 
in the N.sub.2 pressure relief device). The temperature was increased to 
140.degree. C., 160.degree. C., and 180.degree. C., allowing bubbling to 
subside between temperature increases. The yellow liquid was cooled to 
80.degree. C. and the flask containing the liquid was evacuated via vacuum 
pump and refilled with N.sub.2 three times to remove any volatiles still 
present. Quantitative .sup.13 C NMR results of the reaction product are 
presented in Table 
TABLE 3 
______________________________________ 
Reaction Product Example 3 mole % 
______________________________________ 
4,10-Diaza-4,10,10-trimethyl-7-oxa-undecane urea 
4.76 
N,N'-Bis-(4,10-diaza-4,10,10-trimethyl-7-oxa-undecane) urea 
95.24 
Urea 0 
______________________________________ 
EXAMPLE 4 
In this example a polyurethane foam was prepared in a conventional manner. 
The polyurethane formulation in parts by weight (pbw): 
______________________________________ 
COMPONENT TS 
______________________________________ 
E-648 60 
E-519 40 
DC-5043 1.5 
Diethanolamine 1.49 
Water 3.5 
TDI 80 105 Index 
______________________________________ 
E-648 a conventional, ethylene oxide tipped polyether polyol marketed by 
Arco Chemical Co. 
E519 a styreneacrylonitrile copolymer filled polyether polyol marketed b 
Arco Chemical Co. 
DABCO .RTM. DC5043 silicone surfactant marketed by Air Products and 
Chemicals, Inc. 
TDI 80 a mixture of 80 wt % 2,4TDI and 20 wt % 2,6TDI 
For each foam, the catalyst (Table 4) was added to 202 g of the above 
premix in a 32 oz (951 ml) paper cup and the formulation was mixed for 20 
seconds at 5000 RPM using an overhead stirrer fitted with a 2 in (5.1 cm) 
diameter stirring paddle. Sufficient TDI 80 was added to make a 105 index 
foam index=(mole NCO/mole active hydrogen).times.100! and the formulation 
was mixed well for 5 seconds using the same overhead stirrer. The 32 oz 
(951 ml) cup was dropped through a hole in the bottom of a 128 oz (3804 
ml) paper cup placed on a stand. The hole was sized to catch the lip of 
the smaller cup. The total volume of the foam container was 160 oz (4755 
ml). Foams approximated this volume at the end of the foam forming 
process. Maximum foam height and time to reach the top of the mixing cup 
(TOC1) and the top of the 128 oz. cup (TOC2) were recorded (see Table 4). 
TABLE 4 
______________________________________ 
Full Foam 
TOC1 TOC 2 Height 
Height 
CATALYSTS (sec) (sec) (sec) (mm) 
______________________________________ 
0.25 pphp DABCO 33LV/0.10 
13.39 41.13 130.04 
418.87 
pphp DABCO BL-11 
0.25 pphp DABCO 33LV 
20.54 72.94 192.77 
403.10 
0.25 pphp DABCO 33LV/0.18 
13.75 39.68 117.49 
422.92 
pphp Ex 1 catalyst 
______________________________________ 
DABCO 33LV .RTM. catalyst 33 wt % TEDA in dipropylene glycol from Air 
Products and Chemicals, Inc. 
DABCO BL11 catalyst 70 wt % bisdimethylaminoethyl ether in dipropylene 
glycol from Air Products and Chemicals, Inc.. 
The data in Table 4 show that the use of the Example 1 catalyst composition 
afforded an initial reactivity profile as measured by TOC1 and TOC2 
comparable to that of the control catalyst BL-11, with the added advantage 
that full foam height was reached more rapidly. The 33LV only control 
demonstrated that both the control blowing catalyst BL-11 and the Example 
1 blowing catalyst contributed observable catalytic activity at the chosen 
use levels. 
EXAMPLE 5 
N,N,N'-Trimethylbis(aminoethyl)ether (TMAEE) 
A 2-liter stainless steel autoclave was charged with 499.4 g (3.75 moles) 
of dimethylaminoethoxyethanol (DMAEE) and 37.9 g of Cu/ZnO/Al.sub.2 
O.sub.3 catalyst. After purging the reactor with N.sub.2 and H.sub.2, the 
catalyst was reduced in situ under 56 bar of H.sub.2 at a temperature of 
195.degree. C. for 9 hr. The reactor was then cooled to 25.degree. C. and 
vented to ambient pressure. From a sample cylinder connected to a port in 
the reactor head, 177 g (5.7 moles) of monomethylamine (MMA) was charged 
using a 6.5 bar N.sub.2 head to assist in the transfer. After resealing 
the reactor and pressurizing it to 14.8 bar with H.sub.2, the reactor was 
heated to 195.degree. C. and kept at that temperature for 23.3 hr. The 
reactor was then cooled to 25.degree. C. and 600.1 g of reaction product 
was recovered after filtration to remove the catalyst particles. Gas 
chromatographic analysis showed that 65% of the DMAEE was converted and 
the reaction product contained: 
______________________________________ 
Reaction Product 
wt % 
______________________________________ 
N,N,N'-trimethylbis(aminoethyl)ether 
38.2 
Dimethylaminoethoxyethanol 
29.4 
Water 7.1 
Monomethyl amine 5.8 
Other amines 19.5 
______________________________________ 
The reaction product was heated under vacuum to remove the low boiling 
components. A short path distillation was then done to remove heavies and 
any traces of Cu/ZnO/Al.sub.2 O.sub.3 catalyst. The overhead product from 
the short-path distillation (325.6 g) contained: 
______________________________________ 
Overhead Product from Short-Path Distillation 
wt % 
______________________________________ 
N,N,N'-trimethylbis(aminoethyl)ether 
57.2 
Dimethylaminoethoxyethanol 
37.4 
Other amines 5.4 
______________________________________ 
This overhead product was used in the preparation of TMCEAEE in Example 6 
below. 
EXAMPLE 6 
N,N,N'-Trimethyl-N'-2-cyanoethylbis(aminoethyl)ether (TMCEAEE) 
Into a three necked round bottom flask equipped with a teflon coated 
magnetic stir bar, reflux condenser, pressure equalizing dropping funnel, 
and thermometer was placed 325 g of the mixture from Example 1 (1.27 moles 
of contained N,N,N'-trimethylbis(aminoethyl)ether). The mixture was heated 
to 55.degree. C. and 71 g (1.34 moles) of acrylonitrile was added over a 
period of two hours. The reaction was allowed to proceed an additional 
five hours until less than 1% of unreacted 
N,N',N'-trimethylbis(aminoethyl)ether remained. The crude product was used 
without purification in Example 7. 
EXAMPLE 7 
4,10-Diaza-4,10,10-trimethyl-7-oxa-undecanamine 
N,N,N'-Trimethyl-N'-3-aminopropylbis(aminoethyl)ether (TMAPAEE)! 
Into a 1 liter stainless steel autoclave was placed 20 g of chromium 
promoted sponge nickel and 150 g of 28% aqueous ammonium hydroxide. The 
reaction vessel was sealed and purged with nitrogen then hydrogen. The 
contents of the reaction vessel were then heated to 90.degree. C. and the 
pressure adjusted to 82 bars with hydrogen. Then 426 g of the mixture from 
Example 2 was pumped into the reaction vessel over a period of 3.5 hours. 
The reaction was allowed to proceed an additional 50 minutes during which 
time less than 1% of the total hydrogen used was consumed. The hydrogen 
pressure was maintained at 82 bars throughout the reaction by admission of 
hydrogen from a 3.79 liter ballast on demand from a dome regulator. The 
reaction vessel was then cooled and vented and the contents filtered 
through a 0.45 micron fritted stainless steel filter. 
The crude product was placed into a one liter flask and distilled through a 
91.4 cm.times.2.54 cm i.d. packed column to afford 184.5 g of 97.5% pure 
4,10-diaza-4,10,10-trimethyl-7-oxa-undecanamine (IV) collected at 
124.degree. to 133.degree. C. at 13 millibar. 
STATEMENT OF INDUSTRIAL APPLICATION 
The present invention provides a catalyst composition for preparing 
polyurethane products, especially polyurethane foams.