U.S. patent application number 10/140906 was filed with the patent office on 2002-10-10 for continuous process for the production of polyether polyols.
This patent application is currently assigned to BASF Corporation. Invention is credited to Dexheimer, Edward Michael, Hinz, Werner.
Application Number | 20020147370 10/140906 |
Document ID | / |
Family ID | 23758525 |
Filed Date | 2002-10-10 |
United States Patent
Application |
20020147370 |
Kind Code |
A1 |
Hinz, Werner ; et
al. |
October 10, 2002 |
Continuous process for the production of polyether polyols
Abstract
A continuous alkoxylation process for the production of
polyether polyols is disclosed. The process comprises the use of a
plurality of reaction modules each having an outer tube and an
inner tube with annular chamber between them. A spiral reaction
tube is spaced from the inner tube and winds around the inner tube
within the annular chamber. The spiral reaction tube includes an
inlet and an outlet, each of which extend through said outer tube.
A heat exchange medium flows through the annular chamber and
controls the reaction temperature in the spiral reaction tube. The
process comprises continuously forming an initial reaction mixture
of at least one [alkaline] alkylene oxide and an initiator having
at least one reactive hydrogen which is reactive to the [alkaline]
alkylene oxide. Continuously flowing the initial reaction mixture
through a first spiral reaction tube having an internal diameter
and a spiral diameter that promote a pseudo-turbulent flow of the
initial reaction mixture through the first spiral reaction tube to
form a reaction product. Then flowing the reaction product into a
second spiral reaction tube and adding a catalyst and an [alkaline]
alkylene oxide to the reaction product, the second spiral reaction
tube having an internal diameter and a spiral diameter that promote
a pseudo-turbulent flow of the reaction product, the catalyst and
the [alkaline] alkylene oxide in the second spiral reaction
tube.
Inventors: |
Hinz, Werner; (Grosse Ile,
MI) ; Dexheimer, Edward Michael; (Grosse Ile,
MI) |
Correspondence
Address: |
BASF CORPORATION,
LEGAL DEPARTMENT
1609 BIDDLE AVENUE
WYANDOTTE
MI
48192
US
|
Assignee: |
BASF Corporation
|
Family ID: |
23758525 |
Appl. No.: |
10/140906 |
Filed: |
June 14, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10140906 |
Jun 14, 2002 |
|
|
|
09442882 |
Nov 18, 1999 |
|
|
|
6410801 |
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Current U.S.
Class: |
568/620 |
Current CPC
Class: |
B01J 19/242 20130101;
C08G 59/3209 20130101; B01J 19/243 20130101; C08G 65/2696 20130101;
B01J 2219/0002 20130101; B01J 2219/00094 20130101; B01J 2219/00033
20130101 |
Class at
Publication: |
568/620 |
International
Class: |
C07C 041/03 |
Claims
In the claims:
14. (amended) A continuous process of forming polyether polyols
comprising the steps of: a) continuously forming an initial
reaction mixture of at least one alkylene oxide and an initiator
having at least one reactive hydrogen which is reactive to said
alkylene oxide; b) providing a plurality of spiral shaped reaction
tubes operably connected to each other in series and each having an
internal diameter between 0.25 and 3.0 inches, a spiral diameter of
between 2 feet and 10 feet, said spiral shaped reaction tubes
promoting a pseudo-turbulent flow of said initial reaction mixture;
c) continuously flowing said initial reaction mixture through said
first of said spiral shaped reaction tubes to form a reaction
product; d) flowing said reaction product into a second of said
spiral shaped reaction tubes adjacent to said first of said spiral
reaction tubes and adding a catalyst and an alkylene oxide to said
reaction product; e) surrounding said plurality of spiral shaped
reaction tubes with a heat exchange medium, said heat exchange
medium establishing and maintaining a reaction temperature within
said plurality of spiral shaped reaction tubes of between
130.degree. C. and 250.degree. C.; and f) maintaining a pressure in
said spiral shaped reaction tubes of between 200 to 1500 pounds per
square inch.
18. (amended) A continuous process as recited in claim 14 wherein,
step c) further comprises adding said catalyst to said initial
reaction mixture in said first of said spiral shaped reaction
tubes.
19. (amended) A continuous process as recited in claim 14 further
comprising the steps of adding additional amounts of said catalyst
and said alkylene oxide to others of said spiral shaped reaction
tubes.
20. (amended) A continuous process as recited in claim 14 wherein
step e) further comprises the additional steps of establishing and
maintaining a first reaction temperature in a first plurality of
spiral shaped reaction tubes and establishing and maintaining a
second reaction temperature in a second plurality of spiral shaped
reaction tubes, said second reaction temperature being greater than
said first reaction temperature.
21. (new) A continuous process as recited in claim 14 wherein the
spiral reaction tubes curve in a continuous spiral, in the absence
of substantially linear tubes.
22. (new) A continuous process as recited in claim 14 wherein the
spiral reaction tubes provide fluid flow from a first spiral
reaction tube inlet to a first spiral reaction tube outlet, in the
absence of any fluid flow out of said outlet into said inlet.
23. (new) A continuous process as recited in claim 14 wherein the
spiral reaction tubes comprise a continuously curved wall, said
wall being continuously curved in x, y and z planes.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to a method for producing
polyether polyols and, more particularly, to a continuous process
for the production of polyether polyols.
[0002] Polyols are generally defined as compounds that include a
plurality of hydroxyl groups. They can be simple polyols or as
complex as a 10,000 Dalton polyether polyol comprising a heteric
mixture of ethylene oxide and propylene oxide. Polyols,
particularly polyether polyols, are useful when combined with
isocyanates to form polyurethanes. To produce a high quality
polyurethane it is necessary to begin with a high quality polyol.
By high quality it is meant a polyol that has a very narrow size
distribution and a generally uniform composition. Typically polyols
are produced commercially in a batch reactor. A batch reactor is a
large reactor chamber that includes and agitator and a thermal
jacket. The reactants are added in bulk to the reactor under
pressure and the reaction proceeds for hours and sometimes days.
One problem with batch reactors is that thermal control can be hard
to achieve and the entire reaction must be run at a common
temperature. Also the batch reactor needs to be shut down to remove
the reaction product, thus slowing production.
[0003] It would be advantageous to design a continuous reactor
assembly to permit the continuous formation of high quality
polyether polyols. It would be most advantageous to design the
reactor assembly in a manner that promotes turbulent or
pseudo-turbulent flow of the reactants and that is modular to
permit rapid and easy modification of the assembly to meet the
design requirements of a variety of polyols. It would be
additionally beneficial to design the reactor assembly to permit
different reaction temperatures at different points in the
reaction.
SUMMARY OF THE INVENTION
[0004] In general terms, this invention provides a continuous
reactor assembly and a method of using the same to form polyether
polyols. The reactor assembly is of a modular design that permits
rapid and easy modification of the reactor to accommodate different
reaction requirements imposed by the chosen product. The reactor
assembly additionally provides the ability to prepare a polyol that
requires different reaction temperatures at different points in the
reaction.
[0005] In a first embodiment the method of the present invention
comprises a continuous process of forming polyether polyols
comprising the steps of: continuously forming an initial reaction
mixture of at least one [alkaline] alkylene oxide and an initiator
having at least one reactive hydrogen which is reactive to the
[alkaline] alkylene oxide; continuously flowing the initial
reaction mixture through a first spiral reaction tube having an
internal diameter and a spiral diameter that promote a
pseudo-turbulent flow of the initial reaction mixture through the
first spiral reaction tube to form a reaction product; flowing the
reaction product into a second spiral reaction tube operably
connected to the first spiral reaction tube and adding a catalyst
and an [alkaline] alkylene oxide to the reaction product, the
second spiral reaction tube having an internal diameter and a
spiral diameter that promote a pseudo-turbulent flow of the
reaction product, the catalyst and the [alkaline] alkylene oxide in
the second spiral reaction tube; and continuously flowing a heat
exchange medium around said first and said second spiral reaction
tubes, said heat exchange medium establishing and maintaining a
reaction temperature between 130.degree. C. and 250.degree. C. in
said first and said second spiral reaction tubes.
[0006] Another embodiment of the method of the present invention
comprises a continuous process of forming polyether polyols
comprising the steps of: continuously forming an initial reaction
mixture of ethylene oxide and an aromatic initiator in the absence
of a catalyst, the aromatic initiator having at least one reactive
hydrogen which is reactive to the ethylene oxide; continuously
flowing the initial reaction mixture through a first spiral
reaction tube having an internal diameter and a spiral diameter
that promote a pseudo-turbulent flow of the initial reaction
mixture through the first spiral reaction tube to form a reaction
product; flowing the reaction product into a second spiral reaction
tube operably connected to said first spiral reaction tube and
adding a catalyst and an [alkaline] alkylene oxide to the reaction
product, the second spiral tube having an internal diameter and a
spiral diameter that promote a pseudo-turbulent flow of the
reaction product, the catalyst and the [alkaline] alkylene oxide in
the second spiral tube; surrounding the first and the second spiral
reaction tube with a heat exchange medium, the heat exchange medium
establishing and maintaining a reaction temperature between
130.degree. C. and 250.degree. C. in the first and the second
spiral reaction tubes; and pressurizing the first and the second
spiral reaction tube at a pressure between 200 to 1500 pounds per
square inch, thereby maintaining the ethylene oxide and the
[alkaline] alkylene oxide in a liquid state.
[0007] These and other features and advantages of this invention
will become more apparent to those skilled in the art from the
following detailed description of the presently preferred
embodiment. The drawings that accompany the detailed description
can be described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a sectional view of a reaction module;
[0009] FIG. 2 is a schematic view of a first embodiment of a
continuous reactor;
[0010] FIG. 3 is a schematic view of another embodiment of a
continuous reactor;
[0011] FIG. 4 is an alternative embodiment of the continuous
reactor shown in FIG. 2.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0012] Within the several views described below like components are
given the same reference numerals.
[0013] A reactor module is generally indicated at 20 in FIG. 1.
Reactor module 20 comprises an outer tube 22 which defines an
annular chamber 25. In a preferred embodiment, the module 20
further includes an inner tube 24, with the annular chamber 25
defined between the inner tube 22 and the outer tube 24. Reactor
module 20 further includes an upper flange 26 opposite a lower
flange 28. A heat exchange medium inlet 30 extends through the
outer tube 22 into the annular chamber 25 and a heat exchange
medium outlet 32 also extends through the outer tube 22 into the
annular chamber 25. In one embodiment, support rods 34 are secured
to an inner wall 33 of the outer tube 22 and extend toward the
inner tube 24. Alternatively, the support rods 34 may be secured to
inner tube 24 and extend toward outer tube 22.
[0014] A spiral reaction tube 36 is spaced apart from and spirals
around the inner tube 24. Spiral reaction tube 36 rests on support
rods 34 in the annular chamber 25. Spiral reaction tube 36 has a
spiral diameter d1 that is preferably approximately 1 to 2 inches
less than the inner diameter of outer tube 22. Thus, spiral
reaction tube 36 closely follows the inner contour of outer tube 22
which can be varied between about two feet and ten feet in
diameter. The spiral reaction tube 36 is preferably formed from
stainless steel, but as is apparent to one of ordinary skill in the
art, tube 36 could be formed of other materials so long as it is
compatible with the desired reaction as described below. The
internal diameter of the spiral reaction tube 36 can vary between
about 0.25 to 3.0 inches depending on the operating parameters, as
more fully described below. The length of the spiral reactor tube
36 can vary between about 20 feet and several hundred feet
depending on the requirements of the reaction. Preferably, the
length and diameter of spiral reaction tube 36 are chosen to ensure
that any reactants introduced at an inlet 38 have a sufficient
residence time to permit a substantially complete reaction between
the reactants before the product of the reactants reaches an outlet
40. Furthermore the internal diameter and the spiral diameter d1 of
the spiral reaction tube 36 are specifically designed to ensure a
largely turbulent or pseudo-turbulent flow, defined as a flow with
eddy current mixing off a continuously curved wall, of reactants
through the spiral reaction tube 36. This turbulent flow greatly
increases the efficiency of the reaction, especially for polyether
polyol formation. As described below, the velocity of the flow rate
of reactants in the spiral reaction tube 36 is also preferably
chosen to provide turbulent flow. The spiral reaction tube 36 inlet
38 and outlet 40, both extend beyond the outer tube 22. Both the
inlet 38 and the outlet 40 include connectors (not shown) that
permit feed lines (see FIGS. 2 and 3) to be connected to each.
[0015] Adjacent the upper flange 26 and the lower flange 28 is a
seal 60 (see FIGS. 2 and 3) that seals the annular chamber 25 and a
space 42 defined by an inner wall 44 of the inner tube 24. In a
preferred embodiment, the inner tube 24 includes perforations (not
shown) that permit fluid communication between the annular chamber
25 and space 42. A heat exchange medium 46 continuously flows from
heat exchange medium inlet 30 through annular chamber 25 and out of
heat exchange medium outlet 32 and then recirculates through a heat
exchanger 58 (FIGS. 2 and 3). The flow of the heat exchange medium
46 is preferably turbulent within the annular chamber 25. The heat
exchange medium 46 may also flow through space 42, which can serve
as a large heat sink to maintain a reaction temperature within the
spiral reaction tube 36.
[0016] A schematic of a continuous reactor assembly is shown
generally at 50 in FIGS. 2 and 3. Continuous reactor assembly 50
comprises a series of modules including a first module 52, a second
module 54, and additional modules 56 stacked on top of each other
and connected via fasteners (not shown) on their respective upper
and lower flanges. Such fasteners are known in the art. The first
module 52 includes a first spiral reaction tube 76, the second
module 54 includes a second spiral reaction tube 78, and the
additional modules 56 each include an additional spiral reaction
tube 80. The spiral reaction tubes 76, 78, and 80 are operably
connected in series via connector lines 74. By virtue of these
connections a fluid flow is established from the inlet 38 of the
first spiral reaction tube 76 through the outlet 40 of the last
additional spiral reaction tube 80. Preferably the internal
diameter of the first and second spiral reaction tubes 76 and 78
are about 0.75 inches. Preferably the spiral reaction tubes in
subsequent modules have an internal diameter that is larger, on the
order of between 1.5 to 3.0 inches. The larger diameter is
necessary to accommodate the increased viscosity of the reaction
product as the polyol chain grows and the increased volume of the
reaction product while maintaining the turbulent flow
characteristics.
[0017] Each module 52, 54 and 56 includes a heat exchanger
connected to its heat exchange medium inlet 30 and heat exchange
medium outlet 32. This design permits each module 52, 54, and 56 to
have a different reaction temperature. For example, it is
advantageous when adding propylene oxide as the [alkaline] alkylene
oxide to have a higher reaction temperature, preferably 180.degree.
C. to 250.degree. C., than when ethylene oxide is the [alkaline]
alkylene oxide being added. As would be understood by one of
ordinary skill in the art, one or more modules could share a common
heat exchanger 58. Because of the continuous flow of the heat
exchange medium, the temperature differential between the heat
exchange medium and the reaction temperature is small. Said another
way, the heat exchange medium is generally heated to the desired
reaction temperature in a given module 20.
[0018] Continuous reactor assembly 50 further includes a stock
[alkaline] alkylene oxide tank 62 that is operably connected to the
inlet 38 of the first spiral reaction tube 76 through a feed line
66. A pump 64 connected to feed line 66 pressurizes the [alkaline]
alkylene oxide in feed line 66 to a pressure of between about 200
to 1500 pounds per square inch. The actual pressure is chosen to be
above the vapor pressure of the [alkaline] alkylene oxide to thus
maintain the [alkaline] alkylene oxide in a liquid state through
out the continuous reactor assembly 50. A stock initiator tank 68
is operably connected to the inlet 38 of the first-spiral reactor
tube 76 through a feed line 72. A pump 70 connected to feed line 72
pressurizes the initiator in feed line 72 to a pressure of between
about 200 to 1500 pounds per square inch. The [alkaline] alkylene
oxide and initiator react to form an initial reaction mixture in
first spiral reaction tube 76 and to form a reaction product as the
initial reaction mixture exits the outlet of the first spiral
reaction tube 76. A stock catalyst tank 82 is operably connected to
the inlet 38 of the second spiral reactor tube 78 through a feed
line 86 which connects to connector line 74. A pump 84 connected to
feed line 86 pressurizes the catalyst in feed line 86 to a pressure
of between about 200 to 1500 pounds per square inch. Both stock
[alkaline] alkylene oxide tank 62 and stock catalyst tank 82 are
operably connected to the inlet of second spiral reaction tube 78
and additionally operably connected to additional inlets of
additional spiral reaction tubes 80 beyond second spiral reaction
tube 78. Thus catalyst and [alkaline] alkylene oxide can be added
to the reaction product of the first spiral reaction tube 76 at
multiple points in the continuous reactor assembly 50. Another
[alkaline] alkylene oxide tank 88 is operably connected to the
inlet 38 of one or more of the additional spiral reactor tubes 80
through a feed line 92 which connects to connector line 74 joining
additional spiral reactor tubes 80. A pump 90 connected to feed
line 92 pressurizes the other [alkaline] alkylene oxide in feed
line 92 to a pressure of between about 200 to 1500 pounds per
square inch to maintain the other [alkaline] alkylene oxide in a
liquid state. As will be understood by one of ordinary skill in the
art, in some reactions it may be advantageous if pumps 64, 70, 84,
and 90 are operated at lower pressures so long as the pressure is
above the pressure in an associated spiral reaction tube 36 so that
the reactants flow into the continuous reactor 50.
[0019] The outlet of the last module is operably connected through
a feed line 94 to a storage tank 96. The product leaving the final
module can then be further processed to produce the final product,
for example, a polyether polyol. In the continuous reactor assembly
50 shown in FIG. 2 the catalyst is not added until after the
[alkaline] alkylene oxide first reacts with the initiator. This can
be beneficial when it is desired to ensure that all of the reactive
hydrogens on the initiator are replaced with the [alkaline]
alkylene oxide prior to adding catalyst and beginning to build the
polyol chain. As shown in FIG. 3, other polyol formation reactions
are best performed by adding initiator, [alkaline] alkylene oxide
and catalyst to the first spiral reaction tube 76, thus in FIG. 3
the feed line 86 is additionally operably connected to the inlet of
the first spiral reaction tube 76. This is the only difference
between the continuous reactor assembly 50 shown in FIGS. 2 and
3.
[0020] In FIG. 4 an alternative embodiment of the reactor assembly
of FIG. 2 is shown at 150. The only difference in reactor assembly
150 is that it is formed as a single module 20 having a plurality
of spiral reaction tubes 36 operably connected to each other in
series including the first spiral reaction tube 76, second spiral
reaction tube 78 and additional spiral reaction tubes 80. In
addition, a single heat exchange medium inlet 30 and outlet 32
recirculates a heat exchange medium through a single heat exchanger
58 to provide a uniform temperature in the continuous reactor
assembly 150.
[0021] Now that the structure of the continuous reactor assembly 50
has been described, its use to form several example polyether
polyols will be described. The continuous reactor assembly 50 shown
in FIG. 2 was used to form a polyether polyol wherein the first
[alkaline] alkylene oxide was ethylene oxide and the initiator was
an aromatic initiator having reactive hydrogens that are reactive
to ethylene oxide. One example of such an initiator is toluene
diamine. When self catalyzing initiators such as amines, like
toluene diamine, or acids such as phosphoric acid are used it is
preferred that all of the reactive hydrogens are reacted with the
first alkylene oxide prior to adding any additional catalyst. Also,
it is preferred that the free alkylene oxide level not exceed 25
weight % based on the total weight of the alkylene oxide and
initiator, thus it may be necessary to use multiple injections of
alkylene oxide in multiple spiral reaction tubes 76 prior to adding
catalyst. When using ethylene oxide as the alkylene oxide and
toluene diamine it is preferred that 4 moles of ethylene oxide be
added to each mole of toluene diamine prior to addition of
catalyst. The ethylene oxide is fed into the inlet 38 of first
spiral reaction tube 76 under a pressure of between 200 and 1500
pounds per square inch to maintain the ethylene oxide in a liquid
state. The initial reaction mixture of ethylene oxide and toluene
diamine self catalyzes and becomes a reaction product during flow
through the first spiral reaction tube 76 to form a reaction
product wherein ethylene oxide replaces the reactive hydrogens on
the amines of toluene diamine. Preferably the stoichiometry of
[alkaline] alkylene oxide to initiator is designed to produce a
reaction product with very low concentrations of polymeric
[alkaline] alkylene oxide. In subsequent modules, after complete
reaction of the ethylene oxide with the reactive hydrogens on the
toluene diamine, both ethylene oxide and catalyst are added to form
an elongated polyether polyol through the well know chain extension
reaction. The preferred catalysts are potassium hydroxide, sodium
hydroxide, alcoholates of potassium hydroxide, alcoholates of
sodium hydroxide, cesium hydroxide, amines, Lewis acid catalysts,
or double metal complex catalysts, all of which are known in the
art.
[0022] At additional points in the continuous reactor 50 another
[alkaline] alkylene oxide such as propylene oxide can be added to
the reaction product. Because of the length of the spiral reaction
tubes any [alkaline] alkylene oxide added to any module is
substantially completely reacted before the reaction product flows
to the next spiral reaction tube. Thus, the process allows the
formation of polyether polyols which are all of approximately the
same length, thus reducing heterogeneity in the product. In
addition, the design ensures that at any given time the amount of
[alkaline] alkylene oxide in the reaction is low compared to a
batch reactor and that the stoichiometry is better controlled. This
also enhances the quality of the polyether polyol. The multiple
addition points permit an operator to form a variety of polyols,
for example, a polyether polyol having blocks of ethylene oxide and
propylene oxide or a heteric polyol. As will be understood by one
of ordinary skill in the art the separate heat exchangers 58 permit
the reaction temperature to be changed during the reaction. This
ability can be useful to increase the yield of the reaction and the
reaction temperature will be determined in part by the identity of
the [alkaline] alkylene oxide used in a given spiral reaction tube.
The continuous reactor assembly shown in FIG. 3 will be used when
it is not desirable to first replace all of the reactive hydrogens
on the initiator with an [alkaline] alkylene oxide prior to
beginning the elongation reaction. The reactor assembly 150 is more
efficient when it is desired to run the entire reaction at a single
reaction temperature.
[0023] Suitable [alkaline] alkylene oxides for use in the formation
of polyether polyols include ethylene oxide, propylene oxide, and
butylene oxide.
[0024] Suitable catalysts include: the [alkaline] alkylene
catalysts such as potassium hydroxide, sodium hydroxide,
alcoholates of potassium hydroxide, alcoholates of sodium
hydroxide, cesium hydroxide, or amines; Lewis acid catalysts such
as boron trifluoride; and metal complex catalysts such as double
metal cyanide complexes. Preferably the catalyst is added in an
amount of 0.1% to 1.0% in a given addition.
[0025] Suitable initiators include amines and aromatic initiators
having hydrogens which are reactive with [alkaline] alkylene
oxides. Preferred aromatic initiators include toluene diamine,
hydroquinone, and other aromatic initiators. Other initiators
include the well known non-aromatic initiators which have hydrogens
that are reactive to [alkaline] alkylene oxides such as
glycerol.
EXAMPLE 1
[0026] A continuous reactor similar to that disclosed in FIG. 2 was
utilized in preparing the following example. Vicinal toluene
diamine (a mixture of 2,3-and 3,4-toluene diamine) was loaded into
stock initiator tank 68 and kept under nitrogen pressure. Ethylene
oxide monomer was loaded into stock [alkaline] alkylene oxide tank
62 and also kept under nitrogen pressure (35 lbs. per square inch).
Propylene oxide monomer was loaded into the other [alkaline]
alkylene oxide tank 88 and also kept under nitrogen pressure. The
vicinal toluene diarnine was injected together with the ethylene
oxide monomer into a first spiral reaction tube 76. The feed rate
ratio of vicinal toluene diamine to ethylene oxide monomer was
7.3:8.6 (w/w). The pressure upon injection into the first spiral
reaction tube 76 was 995 lbs. per square inch and the heat exchange
medium was at a temperature of 160.degree. C. The reaction product
exiting the first spiral reaction tube was passed into a second
spiral reaction tube 78 wherein the heat exchange medium was at a
temperature of 210.degree. C. Intermediate removed at this point in
the reaction had a hydroxyl number of 758, and an amine number of
216, and a viscosity of 6,200 centipoise at 120.degree. F. The
intermediate from the second spiral reaction tube 78 was injected
together with an aqueous KOH solution (45%) and propylene oxide
monomer mixture from the other [alkaline] alkylene oxide tank 88
into a third spiral reaction tube 80. The feed ratio of
intermediate to monomer mixture was 7.9:9.0 (w/w). The catalyst
concentration of KOH was 0.2%. The heat exchange medium was at a
temperature of 180.degree. C. The reaction product from the third
spiral reaction tube was passed through a fourth spiral reaction
tube 80 wherein the heat exchange medium was at a temperature of
230.degree. C. The product from the fourth spiral reaction tube was
placed under high vacuum to remove unreacted [alkaline] alkylene
oxide monomer. The obtained product had a hydroxyl number of 395,
and an amine number of 103, and a viscosity of 6,600 centipoise at
80.degree. F.
EXAMPLE 2
[0027] Example 2 was prepared similar to Example 1. Vicinal toluene
diamine and ethylene oxide were fed into the first spiral reaction
tube at a ratio of initiator to monomer of 7.3:9.0 (w/w). The
pressure at the injection point was 660 lbs. per square inch and
the heat exchange medium was at a temperature of 140.degree. C. The
product from the first spiral reaction tube was passed through a
second spiral reaction tube wherein the heat exchange medium was at
a temperature of 200.degree. C. The intermediate from the second
spiral reaction tube had a hydroxyl number of 749, and an amine
number of 205, and a viscosity of 6,300 centipoise at 120.degree.
F. The intermediate from the second spiral reaction tube was
injected together with an aqueous KOH solution (45%) and propylene
oxide monomer mixture into a third spiral reaction tube. The feed
ratio of intermediate to propylene oxide monomer mixture was
7.2:8.9 (w/w). The catalyst concentration of KOH was 0.2% and the
heat exchange medium was at a temperature of 180.degree. C. The
product from the third spiral reaction tube was passed through a
fourth spiral reaction tube wherein the heat exchange medium was at
a temperature of 230.degree. C. The product from the fourth spiral
reaction tube was placed under high vacuum to remove unreacted
[alkaline] alkylene oxide monomer. The product obtained had a
hydroxyl number of 366, and an amine number of 94, and a viscosity
of 4,000 centipoise at 80.degree. F.
EXAMPLE 3
[0028] Example 3 was prepared similar to Example 1. The vicinal
toluene diamine and ethylene oxide monomer mixture were injected
into a first spiral reaction tube at a feed ration of 8.4:8.2
(w/w). The pressure at injection was 650 lbs. per square inch and
the heat exchange medium was at a temperature of 140.degree. C. The
product from the first spiral reaction tube was passed through a
second spiral reaction tube wherein the heat exchange medium was at
a temperature of 200.degree. C. The intermediate at this point had
a hydroxyl number of 830 and an amine number of 297. The product
from the second spiral reaction tube was injected with aqueous KOH
solution (45%) and propylene oxide monomer mixture into a third
spiral reaction tube. The feed ratio of intermediate to propylene
oxide monomer mixture was 8.1:8.8 (w/w). The catalyst concentration
of KOH was 0.2% and the heat exchange medium was at a temperature
of 180.degree. C. The reaction product from the third spiral
reaction tube was passed into a fourth spiral reaction tube wherein
the heat exchange medium was at a temperature of 230.degree. C. The
product from the fourth spiral reaction tube was placed under high
vacuum to remove unreacted [alkaline] alkylene oxide monomer and
the product obtained had a hydroxyl number of 421 and an amine
number of 143.
EXAMPLE 4
[0029] Example 4 was prepared similar to Example 1. To the first
spiral reaction tube vicinal toluene diamine, ethylene oxide
monomer, and aqueous KOH catalyst solution (45%) were injected into
the first spiral reaction tube. The feed ratio of vicinal toluene
diamine to ethylene oxide monomer was 6.6:9.2 (w/w). The catalyst
at this point had a hydroxyl number of 750 and an amine number of
139. The product from the second spiral reaction tube was injected
together with propylene oxide monomer mixture into a third spiral
reaction tube. The feed ratio of intermediate to propylene oxide
mixture was 8.7:8.9 (w/w). The heat exchange medium was at
180.degree. C. The product from the third spiral reaction tube was
passed into a fourth spiral reaction tube wherein the heat exchange
medium was at a temperature of 230.degree. C. The product from the
fourth spiral reaction tube was placed under high vacuum to remove
unreacted alkylene monomer and the product obtained had a hydroxyl
number of 388 and an amine number of 69.
[0030] The present invention has been described in accordance with
the relevant legal standards, thus the foregoing description is
exemplary rather than limiting in nature. Variations and
modifications to the disclosed embodiment may become apparent to
those skilled in the art and do come within the scope of this
invention. Accordingly, the scope of legal protection afforded this
invention can only be determined by studying the following
claims.
* * * * *