Process for the manufacture of N-(polyoxyalkyl)-N-(alkyl)amines

The present invention provides a novel process for manufacturing N-(polyoxyalkyl)-N-(alkyl) amines. The process is characterized by reacting a polyetheramine in which the amine groups are predominantly primary in character with a low molecular weight, sterically hindered alcohol in the presence of an appropriate catalyst, such as nickel using specific reaction conditions.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a process for the manufacture of N 
(polyoxyalkyl)-N-(alkyl)-amines by reacting in one step a polyetheramine 
in which the amine groups are predominently primary in character with a 
low molecular weight, sterically hindered alcohol. These 
N-(polyoxyalkyl)-N-(alkyl)-amines are characterized by a high content of 
secondary amine groups. 
2. Prior Art 
Amination of polymeric alcohols with ammonia under various reaction 
conditions to produce primary amines is well known. Similarly, it is also 
well known that low molecular weight primary amines react with low 
molecular weight alcohols to form secondary amines, and low molecular 
weight secondary amines react with low molecular weight alcohols to form 
tertiary amines. 
In U.S. Pat. No. 4,638,336 amines are prepared from an aliphatic alcohol 
and, as aminating agents ammonia, a primary amine and a secondary amine. 
When the secondary amine was used, the product was a tertiary amine. 
In DE 3,539,266 tertiary amines were prepared from the reaction of 
secondary amines with alcohols in the presence of a 
hydrogenation/dehydrogenation catalyst. 
In JP 62 51646 alpha, omega ditertiary amines formed from the reaction of 
an alpha, omega diol and a secondary amine in the presence of hydrogen and 
copper or cobalt catalyst. 
In DE No. 3,432,015 very high tertiary amines were derived from the 
reaction of dimethylamine amine and a C12 alcohol. Copper/tin and other 
catalysts were discussed. 
In U.S. Pat. No. 4,625,063 high purity tertiary amines formed from the 
reaction of an alcohol and a primary or secondary amine where the catalyst 
contained copper/nickel and a Group VIII metal. 
In JP 59-222,448 alkyldimethylamines were produced from the reaction of 
dimethylamine and an alcohol. 
In U.S. Pats. Nos. 4,404,404 and 4,409,399 tertiary amines were derived 
from the reaction of dimethylamine and dodecanol in the presence of copper 
on nickel oxide catalysts. 
In U.S. Pat. No. 4,442,306 tertiary amines were produced from the reaction 
of alcohol and a secondary amine using a copper formate catalyst. 
In JP No. 62 33138 there is described a special catalyst for controlling 
the reaction of secondary amines with alkane diols to give mono- and 
ditertiary amine products. 
However, no art teaches the direct manufacture of polyetheramines having a 
high secondary amine content by directly reacting a polyol with a primary 
amine. In fact, the only related art, U.S. Pat. No. 4,686,242, teaches 
that only low levels (less than 40% of total amine) of secondary amine 
terminated polyethers can be obtained when one attempts to directly 
manufacture the secondary polyetheramine from primary amines and a 
polyether polyols. 
Another method for preparing a secondary polyetheramine is described in 
U.S. Pat. No. 4,286,074, where a pre made primary polyetheramine is first 
allowed to react with acetone to form the resulting ketimine. This product 
is hydrogenated to the expected high secondary amine containing product. 
Although this process is technically feasible for polyetheramines of other 
molecular weights and functionalities, it is not very efficient or 
economically attractive and the current commercial suppliers of primary 
polyetheramines are quite limited. 
These patents clearly indicate that it is generally expected from the art 
that a primary amine, when reacted with an alcohol, should form the art 
expected secondary amine. However, as noted in U.S. Pat. No. 4,686,242, 
the reaction actually generates a product which is predominantly primary 
amine in character. It has now been discovered that it is possible to 
overcome this limitation by reacting a polyetheramine in which the amine 
groups are predominantly primary in character with a sterically hindered, 
low molecular weight alcohol to obtain high levels of secondary amine 
termination on the polyetheramine. 
OBJECT OF THE INVENTION 
It is a primary object of the present invention to provide N 
(polyoxyalkyl)-N-(alkyl) amines wherein the content of secondary amine 
groups exceeds the content of primary and tertiary amine groups. 
It is another object of the present invention to provide a novel route to 
such amines via the reaction of alcohols with primary polyetheramines. 
Other objects of the invention will be made apparent from the description 
and examples which follow. 
SUMMARY OF THE INVENTION 
The present invention provides a novel process for manufacturing 
N-(polyoxyalkyl) N (alkyl) amines. The process is characterized by 
reacting a polyetheramine in which the amine groups are predominantly 
primary in character with a low molecular weight, sterically hindered 
alcohol in the presence of an appropriate catalyst, such as nickel, using 
specific reaction conditions. 
DETAILED DESCRIPTION OF THE INVENTION 
In accordance with the present invention there is provided a process for 
manufacturing N-(polyoxyalkyl) N-(alkyl)amines by direct, catalytic 
reaction of a polyetheramine in which the amine groups are predominantly 
primary in character with a sterically hindered, low molecular weight 
alcohol. 
The polyetheramines are those having a molecular weight of at least 400, 
preferably 2000 or more, and having a primary amine content relative to 
the total amine content of 50 percent or more and preferably 90 percent or 
more. The amine content is generally measured as milliequivalents per 
gram. Such polyetheramines are well known in the art and typical examples 
are such commercially available materials as Jeffamine.TM. T-403, D-2000, 
T-3000 and T-5000. 
The sterically hindered, low molecular weight alcohols are those 
represented by the formula R'"OH wherein R'" is a secondary or tertiary 
alkyl or aryl group containing from 3 to 18 carbon atoms, preferably 3 to 
6 carbon atoms and most preferably an isopropyl group. Examples of such 
alcohols are phenol, sec-butanol, cyclohexanol, t-butanol and most 
preferably isopropanol. 
The product of the present process is an N-(polyoxyalkyl)-N-(alkyl)amine of 
the general formula: R[X].sub.(hz) [(Y).sub.p (Z).sub.s (T).sub.t ].sub.z 
-(hz) wherein R is an initiator radical based on a compound containing 
Zerewitinoff active hydrogen atoms. Such compounds are capable of 
initiating polymerization with alkylene oxides when used with a suitable 
catalyst (e.g., potassium hydroxide, zinc hexacyanocobaltate). 
Examples of such compounds include but are not limited to: monofunctional 
compounds such as methanol, butanol, phenol, nonylphenol, lauryl alcohol, 
2-methoxyethanol; difunctional compounds such as ethylene glycol, 
propylene glycol, water, 1,4 butanediol, diethylene glycol; trifunctional 
compounds such as trimethylolpropane, glycerine; and other polyfunctional 
compounds such as pentaerythritol, sorbitol, ammonia, ethylene diamine, 
1,3 diaminopropane, 1,6 hexanediamine, isomers of phenylenediamine and 
toluenediamine, 4,4'-diphenylmethane diamine and its isomers, 
diethanolamine, ethanolamine, dimethylethanolamine N-methylethanolamine, 
triethanolamine, triisopropanolamine, ethylmercaptan, thiophenol and 
propylene disulfide. 
Additional examples of compounds suitable for initiating polymerization of 
alkylene oxides are the various oligomeric polyols known in the art. These 
include the poly-(1,4-butylene oxide)polyethers and the hydroxyl and amine 
terminated poly-(butadienes). When polyols (or other oligomers) are used 
for initiating polymerization of the alkylene oxides, their molecular 
weights can range from 400 to about 3000. When the conventional initiators 
such as described above (i.e., glycerine, water, etc.) are used, their 
molecular weight can range from about 18 (for water) up to about 400. 
Preferably R contains from two to six carbon atoms and most preferably 
three to six carbon atoms. 
The alkylene oxides that find utility in the present invention are those 
well known in the art. These include propylene oxide, ethylene oxide, the 
alpha olefin oxides such as 1,2-epoxybutane and 1,2-epoxyoctadecane, 
oxytane and tetrahydrofuran. "X" denotes the group represented by the 
formula: 
##STR1## 
"Y" denotes the group represented by the formula: 
##STR2## 
"Z" denotes the group represented by the formula: 
##STR3## 
"T" denotes the group represented by the formula: wherein: 
the letter "a" defines the ethylene oxide content of the N (polyoxyalkyl) 
N-(alkyl)amine and e from a value of zero to 175. The preferred range for 
"a" is 0 to 90. When b or c is not equal to zero, the most preferred range 
for "a" is 0 to 50. 
The letter "b" defines the propylene oxide content of the N 
(polyoxyalkyl)-N (alkyl)amine and can also range from a value of zero to 
175. Preferably, "b" should range from 20 to 115 and most preferably from 
25 to 98. 
The letter "c" defines the alpha olefin oxide 
##STR4## 
content of the N (polyoxyalkyl)-N-(alkyl) amine and can range from 0 to 
30. Preferably, "c" can range from zero to 15 and most preferably, from 0 
to 2. 
The letter "n" equals from 1 to 3, preferably 1. 
Two aspects of a, b and c are important and must be noted. The first is 
that the sum of a+b+c must always be greater than or equal to 2 when n 
equals 1. Second, a, b and c indicate ethylene oxide, propylene oxide and 
alpha olefin oxide which can be incorporated into the product backbone in 
any sequence, i.e., blocks or random sequence, in any configuration. 
R' is an alkyl group containing from two carbon atoms to eighteen carbon 
atoms depending on the alpha olefin oxide used in preparation of the 
amine. While R' can contain up to eighteen carbon atoms, two carbon atoms 
are most preferred. 
R" is hydrogen or an alkyl group containing up to eighteen carbon atoms. It 
is preferred that R" is hydrogen or alkyl group containing up to two 
carbons, and most preferably a methyl group. 
R'" is a secondary or tertiary alkyl or aryl group containing from three to 
eighteen carbon atoms, preferably three to six carbon atoms and most 
preferably an isopropyl group. 
R "" is an alkyl or aryl group containing from two to twelve carbon atoms, 
preferably an alkyl group containing from two to six carbon atoms, and 
most preferably an isopropyl group. 
The letter "h" indicates the relative hydroxyl content remaining after 
amination and has been found to range from 0 to 0.7 with 0.1 to 0.3 
preferred and 0 to 0.15 most preferred. As noted, "h" is related to the 
percent amination, i.e. 30 percent amination would result in a hydroxyl 
content of 70 percent and thus "h" would equal 0.7. Values are obtained by 
taking the total amine number as measured in milliequivalents per gram, 
and dividing by the initial hydroxyl number (meg/g) and subtracting that 
quotient from 1.0. 
The letter "p" indicates the relative primary amine content to total amine 
content formed during amination and is from 0 to 0.4. 
The letter "s" indicates the relative secondary amine content to total 
amine content formed during amination and is from 0.5 to 1.0, preferably 
from 0.70 to 1.0. 
The letter "t" indicates the relative tertiary amine content to total amine 
content formed during amination and is from 0 to 0.15, preferably from 0 
to 0.05. The sum of p, s and t must equal 1.0. 
The letter "z" is an integer derived from the number of Zerewitinoff active 
hydrogens on the initiator. The letter "z" is preferably 1 to 6, and most 
preferably 3 to 6. 
The present invention can also be practiced by charging a polyether polyol 
and ammonia in place of the polyetheramine and allowing the sterically 
hindered, low molecular weight alcohol to react with the high molecular 
weight polyetheramine formed in situ. However, because of the competing 
reactions this is not a preferred route. 
The reaction is carried out in a batch autoclave at elevated temperature, 
generally between 175.degree. C. to 250.degree. C. and preferably 
190.degree. C. to 240.degree. C. The reaction pressure will range from 250 
to 2000 psi, preferably 500 to 1250 psi. The reaction is run in the 
presence of hydrogen. Under these conditions the amine containing polymer 
remains in the liquid phase. The stoichiometry on a amine to hydroxyl 
equivalent basis will range from 1:2 to 1:20, preferably 1:5 to 1:10. The 
reaction will generally occur in 4 to 24 hours. The catalyst is a nickel, 
copper or cobalt based catalyst, most preferably nickel, either 
unsupported or on a support. When the catalyst is supported, the metal 
content is at least 25%, with 50% or more preferred. The catalyst loading 
is generally on the order of 1 to 5 weight percent based on total charge. 
In addition to the batch process described above, the amination can be 
carried out using a liquid phase continuous amination process. In this 
process, a pelletized or extruded form of the nickel, copper or cobalt 
catalyst on a support, most preferably nickel, is charged to a high 
pressure tubular reactor. The reactor is heated to 175.degree. C. to 
250.degree. C., preferably 190.degree. C. to 240.degree. C. and a mixture 
of primary amine terminated polyether and alcohol (1:2 to 1:20, preferably 
1:5 to 1:10 on an equivalents basis) is pumped through the reactor at a 
flow rate ranging from about 0.5 to 5.0 g feed/g catalyst/hr. Hydrogen is 
added to the feed stream at a minimum rate of 1, standard cc/min. Reactor 
pressure is controlled by a back pressure regulator to 25% to 2000 psi, 
preferably 500 to 120psi. The products isolated from the continuous 
process are similar to those isolated from the batch process. 
The N (polyoxyalkyl)-N (alkyl)amines of the present invention find utility 
in the preparation of polyureas and polyurethane urea products. 
Whereas the exact scope of the instant invention is set forth in the 
appended claims, the following specific examples illustrate certain 
aspects of the present invention and, more particularly, point out methods 
of evaluating the same. However, the examples are set forth for 
illustration only and are not to be construed as limitations on the 
present invention except as set forth in the appended claims. All parts 
and percentages are by weight unless otherwise specified.

EXAMPLES 
Polyetheramine #1=A 5000 MW primary triamine polyether, commercially 
available from Texaco Chemical Company as Jeffamine.TM. T-5000. 
Catalyst #1=Ni-5136P, a 65% Ni on silica alumina support in powdered form, 
made commercially by Harshaw-Filtrol Partnership. 
Example #1: Polyetheramine #1 (1204.1 g.), isopropyl alcohol (424.7 g), and 
Catalyst #1 (42.1 g) were charged to a 1 gallon reactor. The reactor was 
purged with hydrogen to remove air and pressurized to 200 psi with 
hydrogen. The system was heated to 190.degree. C. and held at temperature 
for about 20 hours. Filtration of the catalyst and removal of the excess 
volatile materials gave a product with the following analysis: total amine 
was 0.496 meg/g, primary amine was 0.063 meg/gm, and tertiary amine was 
0.002 meg/gm. The secondary amine, by difference, was 0.431 meg/gm, i.e., 
86% of the total amine. 
Comparative Example #1: Example #1 was repeated with the exception that the 
isopropyl alcohol was replaced with the equivalent mole ratio of methanol. 
Polyetheramine #1 (1734.0 g.), methanol (336.4 g.), and Catalyst #1 (46.4 
g.) were charged to a 1 gallon reactor. The reactor was purged with 
hydrogen, pressurized to about 200 psi with hydrogen, then heated to about 
190 deg C. for about 22.5 hours. The product had the following analyses: 
total amine was 0.484 meg/gm; primary amine was 0.040 meg/gm; and tertiary 
amine was 0.434 meg/gm. The secondary amine, by difference, was 0.020 
meg/gm, i.e., 4% of the total amine. 
Comparative Example #2:Example # 1 was repeated with the exception that the 
isopropyl alcohol was replaced with the equivalent mole ratio of ethanol. 
Polyetheramine #1 (810.0 g.), ethanol (225.8 g.), and Catalyst #1 (23.3 
g.) were charged to a 2 liter reactor. The reactor was purged with 
hydrogen, pressurized to about 200 psi with hydrogen, then heated to about 
190 deg C. for about 19 hours. The product had the following analyses: 
total amine was 0.477 meg/g; primary amine was 0.058 meg/gm; tertiary 
amine was 0.422 meg/g. The secondary amine, by difference, was 0.039 
meg/gm; i.e., 8% of total amine. 
Comparative Example #3 Example #1 was repeated with the exception that 
isopropyl alcohol was replaced with the equivalent mole ratio of n 
propanol. Polyetheramine #1 (1374.0 g.), n-propanol (499.7 g.), and 
Catalyst #1 (42.1 g.) were charged to a 1 gallon reactor. The reactor was 
purged with hydrogen, pressurized to about 200 psi with hydrogen, then 
heated to about 190 deg C. for about 18.5 hours. The product had the 
following analyses: total amine 0.401 meg/gm; primary amine was 0.025 
meg/gm; and tertiary amine was 0.315 meg/g. The secondary amine, by 
difference, was 0.063 meg/gm; i.e., 16% of total amine.