U.S. patent application number 10/175729 was filed with the patent office on 2002-12-05 for process and apparatus for preparing a composition using a slurry feed.
Invention is credited to Keillor, Peter T. III.
Application Number | 20020180099 10/175729 |
Document ID | / |
Family ID | 22485909 |
Filed Date | 2002-12-05 |
United States Patent
Application |
20020180099 |
Kind Code |
A1 |
Keillor, Peter T. III |
December 5, 2002 |
Process and apparatus for preparing a composition using a slurry
feed
Abstract
A process and apparatus for preparing compositions including one
or more resinous materials and/or other ingredients using a
continuous reactor combined with a slurry vessel for feeding a
slurry feed stream to the reactor. More specifically, the process
and apparatus prepares a composition by feeding a reactive slurry
of one or more monomers and/or oligomers into a continuous reactor
extruder to manufacture one or more resinous materials. Optionally,
the resinous material may be continuously conveying to a mixer for
continuously mixing the resinous material with other ingredients to
form a blended composition.
Inventors: |
Keillor, Peter T. III; (Lake
Jackson, TX) |
Correspondence
Address: |
THE DOW CHEMICAL COMPANY
INTELLECTUAL PROPERTY SECTION
P. O. BOX 1967
MIDLAND
MI
48641-1967
US
|
Family ID: |
22485909 |
Appl. No.: |
10/175729 |
Filed: |
June 19, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10175729 |
Jun 19, 2002 |
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09595041 |
Jun 15, 2000 |
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6436326 |
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60139281 |
Jun 15, 1999 |
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Current U.S.
Class: |
264/211.24 |
Current CPC
Class: |
B01J 19/0006 20130101;
B01J 8/003 20130101; G01N 29/323 20130101; B01J 2219/00213
20130101; B29B 7/7461 20130101; G01N 2291/0251 20130101; B01J
2219/002 20130101; B29B 7/007 20130101; G01N 2291/0255 20130101;
B29C 2948/92514 20190201; B01J 2219/00033 20130101; G01N 2291/02818
20130101; G01N 29/032 20130101; B01J 19/1862 20130101; B01J 8/002
20130101; B01J 2219/00229 20130101; B29C 48/385 20190201; B01J
19/10 20130101; B29C 48/793 20190201; B01F 27/1143 20220101; B01J
2219/00202 20130101; G01N 2291/102 20130101; G01N 2291/011
20130101; G05D 21/02 20130101; B29C 2948/92704 20190201; G01N
29/326 20130101; B29B 7/7485 20130101; G01N 2291/02836 20130101;
B29C 48/92 20190201; B29K 2063/00 20130101; B01F 33/81 20220101;
B01J 19/20 20130101; B01J 8/20 20130101; C08G 59/621 20130101; C08G
59/00 20130101 |
Class at
Publication: |
264/211.24 |
International
Class: |
B29C 047/78 |
Claims
What is claimed is:
1. A process for preparing a composition of matter comprising the
steps of: (a) continuously preparing a slurry of one or more
components of the composition of matter, (b) continuously feeding
the slurry of one or more components of the composition of matter
into at least one continuous reactor, (c) continuously forming the
composition of matter in the reactor from said slurry, and (d)
recovering said composition of matter from said reactor, (e)
conveying the polymer from the reactor to a mixer through a
connection between the reactor and the mixer, and (f) preparing the
composition of matter by admixing, in the mixer, the polymer and
one or more other components of the composition of matter.
2. The process of claim 1 wherein the mixer is an extruder.
3. The process of claim 1 wherein the composition of matter is a
coating formulation.
4. The process of claim 3 wherein the slurry is prepared from (i) a
substance containing an average of more than one vicinal epoxy
group per molecule, and/or (ii) a substance containing an average,
per molecule, of more than one moiety that is reactive with the
substance (i).
5. The process of claim 4 wherein the substance (ii) is a
polyhydroxyl compound.
6. The process of claim 5 wherein the polyhydroxyl compound is
bisphenol-A.
7. The process of claim 4 wherein, in step (f), the one or more
other components admixed with the polymer is at least one member
selected from the group comprising: a substance that is reactive
with an epoxy resin, a substance that is not reactive with an epoxy
resin, a pigment, a stabilizer and a filler.
8. The process of claim 7 wherein the substance reactive with an
epoxy resin is a polyester.
9. The process of claim 7 wherein an epoxy resin is prepared in a
first reactor, and a substance that is reactive with an epoxy resin
is prepared in a second reactor.
10. An apparatus for preparing a composition of matter comprising:
(a) a means for continuously feeding a slurry of one or more
components of the composition of matter into at least one
continuous reactor to form a composition of matter, and (b) a means
for recovering said composition of matter from said reactor.
11. An apparatus for preparing a polymer comprising: (a) a slurry
vessel for continuously preparing a slurry of one or more monomers
and/or oligomers, (b) at least one continuous reactor connected to
said slurry vessel, said reactor adapted for continuously preparing
one or more polymers by reacting the slurry of one or more monomers
and/or oligomers in the reactor, (c) a means for continuously
feeding the slurry into the at least one continuous reactor to form
a polymer, and (d) a means for recovering said polymer from said
reactor.
12. The apparatus of claim 11 wherein the reactor is an
extruder.
13. The apparatus of claim 11 including (e) a mixer connected to
said reactor, said mixer adapted for preparing the composition of
matter by admixing, in the mixer with the polymer(s) prepared in
each reactor, one or more other components of the composition, and
(f) a means for conveying the polymer(s) from each reactor to a
mixer through a connection between each reactor and the mixer.
14. The apparatus of claim 13 including a means for conveying the
polymer(s) from each reactor to the mixer at a controlled rate.
15. The apparatus of claim 11 wherein the polymer prepared is an
epoxy resin.
16. The apparatus of claim 13 wherein the at least one or more
other components admixed with the polymer(s) is at least one member
selected from the group comprising: a substance that is reactive
with an epoxy resin, a substance that is not reactive with an epoxy
resin, a pigment, a stabilizer and a filler.
17. The apparatus of claim 13 wherein the mixer is an extruder.
18. The apparatus of claim 13 including a first reactor for
preparing an epoxy resin and a second reactor for preparing a
substance that is reactive with the epoxy resin.
19. The apparatus of claim 18 wherein the substance reactive with
an epoxy resin is a polyester.
20. An apparatus of claim 11 wherein the composition of matter is a
coating formulation.
21. The apparatus of claim 20 wherein the slurry is a mixture of
(i) a substance containing an average of more than one vicinal
epoxy group per molecule, and (ii) a substance containing an
average, per molecule, of more than one moiety that is reactive
with the substance (i).
22. The apparatus of claim 21 wherein the substance (ii) is a
polyhydroxyl compound.
23. The apparatus of claim 22 wherein the polyhydroxyl compound is
bisphenol-A.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/139,281, filed Jun. 15, 1999.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a process and an apparatus for
preparing a composition using a continuous extruder. More
particularly, this invention relates to a process and an apparatus
for preparing a composition by feeding a slurry from a slurry
vessel into a continuous reactor.
[0003] Heretofore, chemical compositions, for example polymers,
have been prepared using continuous reactor extruders. For example,
U.S. Pat. No. 4,612,355 discloses the use of extruders for the
manufacture of plastics. More specifically, U.S. Pat. No. 4,612,355
discloses the use of reaction extruders to prepare epoxy
resins.
[0004] Typically, the feed of reactants to such extruders is
carried out as solids and or as a melt prior to feeding the
extruder. It is difficult to thoroughly and intimately mix the
solids together before or while feeding the solids to an extruder.
Some chemicals cannot be fed as solids and must be prepared in a
different manner.
[0005] In addition, feed accuracy demands for continuous processes
are high, particularly when the continuous process is plug flow,
with minimum backmixing, and a step polymerization. Step
polymerizations involving two different di-functional feeds,
represented by A-A and B-B, where A reacts with B, are very
sensitive to the ratio of A-A and B-B regarding final molecular
weight and physical properties.
[0006] Generally, liquid feeds are preferred for step
polymerization processes, as a feed accuracy of less than 0.1% can
be achieved using liquid feeds. However, in some manufacturing
processes, one or more of the feeds must be a solid, because a
liquid feed form may not be desirable due to degradation or safety
concerns. Thus, a solid feed system, such as a loss-in-weight
feeder, is required when a liquid feed can not be used. The
accuracy of loss-in-weight feeders can approach 0.25% over a one
minute interval, but is generally greater than 1% over a 5 second
interval. It would be advantageous to avoid having to use a solid
feed systems in processes which can not accurately handle
solids.
[0007] It is therefore desired to provide a process and apparatus
for preparing a composition using a slurry feed to a reactor such
as an extruder. More preferably, it is desired to provide a process
and apparatus which allows averaging of the short term accuracy of
a solids feeder by holding up several minutes worth of feed in a
continuously stirred, backmixed vessel in combination with a liquid
feed.
SUMMARY OF THE INVENTION
[0008] The present invention pertains to a process and an apparatus
for preparing compositions from one or more resinous materials and
other ingredients using a continuous reactor combined with a
continuous slurry feed apparatus for feeding the slurry feed stream
to the reactor.
[0009] In one specific embodiment of the present invention, the
present process and apparatus prepares a composition by feeding a
slurry of one or more monomers and/or oligomers into a continuous
reactor to manufacture one or more resinous materials. The resinous
materials may optionally be combined with other additives in a
mixer or recovered as a flake for further use.
[0010] This process integrates a slurry feeding operation with a
reactive extrusion operation. The present invention avoids problems
associated with raw materials feed rate variation when using a
solid additive to a liquid material without having to melt the
solids. The present invention advantageously provides accurate feed
flow from a solids feeder.
BRIEF DESCRIPTION OF THE DRAWING
[0011] FIG. 1 shows a schematic representation of one embodiment of
the apparatus of the present invention and in particular,
illustrates a slurry feed vessel in combination with a continuous
reactor extruder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The present invention is directed to a process and an
apparatus for achieving consistent feed of a solid feed to a
continuous process by using continuously formed and mixed slurry of
the solid feed or feeds with a liquid feed. Generally, a
loss-in-weight feeder is used to feed the solid to the slurry
mixing vessel, and an accurate liquid metering system is used to
feed each liquid feed used in the slurry.
[0013] The level in the slurry process is controlled by the speed
of a pump that forwards the slurry to the process. The level should
be measured by a means that does not introduce gas into the system,
such as a diaphragm level transmitter or ultrasonic level
transmitter. Consistent level control is required to provide a
steady feed rate to the process and to ensure adequate mixing. The
level in the vessel is controlled at a point above the agitator to
create a vortex capable of entraining the solids. The loss in
weight feeder discharge should drop the solid feed directly into
the vortex.
[0014] One embodiment of the present process and apparatus of the
present invention involves the preparation of a composition and/or
certain resinous materials that are contained within the
composition using a reactor extruder in combination with a slurry
vessel.
[0015] The term "slurry" herein means one or more solid materials
suspended in a liquid material.
[0016] With reference to FIG. 1, there is shown a slurry vessel 10
connected to a reactor 20. A liquid monomer stream in conduit 11
from storage vessel (not shown) may be heated by an exchanger (not
shown) and rate added to the slurry vessel 10 using a rate addition
pump (not shown) or alternately a control valve (not shown). The
temperature of the liquid monomer stream 11 is controlled to
produce a slurry stream that is pumpable. In some cases, the liquid
monomer stream 11 is heated to a temperature required to melt any
solid monomers present in the slurry vessel 10.
[0017] A solid monomer stream in conduit 12 from a solid addition
system 13 is rate added to the slurry vessel 10 and a high speed
mixer 14 in the slurry vessel 10 combines the solid and liquid
monomers to form the reactive slurry stream in conduit 15. The
slurry stream 15 is continuously rate added to the reactor 20 using
rate addition pump (not shown). If required to complete the
reaction, the slurry 15 is combined with a catalyst from catalyst
addition pump (not shown). The slurry and catalyst may be combined
together in the slurry feed line 15 or alternatively in a high
speed inline mixer (not shown) located within slurry line 15 and
fed into the continuous reactor 20.
[0018] The monomers and other additives such as a catalyst added to
the continuous reactor 20 are heated to sufficient temperatures
required to produce a reaction within the reactor and ultimately a
reaction product stream in conduit 21 exits the reactor 20.
[0019] Although not shown, various other embodiments of the present
invention, may include for example, where the output of the
continuous reactor 20 such as a resinous material is force conveyed
through a conduit connecting the continuous reactor 20 with a
continuous mixer using a resinous material pump. A liquid additive
storage tank and metering flow control pump can also be attached to
the system to add any liquid additives or other ingredients to the
resinous material before conveying to the mixer. A preferred
process and apparatus useful in the present invention for combining
a reactor with a mixer is described in copending U.S. patent
application, Attorney Docket No. 44646, entitled "Process and
Apparatus For Preparing A Composition Using A Continuous Reactor
And Mixer In Series" filed by Keillor et al., of even date
herewith, incorporated herein by reference.
[0020] In addition, the conditions of the resinous material from
continuous reactor must be modified before introduction into the
continuous mixer. For example, a filter system may be used to
remove any particulate matter from the resinous material; or a heat
exchanger system may be used to reduce the temperature of the
resinous material to the required temperatures for proper mixing.
Other solid ingredients may be added from a continuous addition
system to the mixer and combined with the resinous material feed
stream. At the solids discharge end of the continuous mixer, the
product may be transferred to a flaker to solidify and form the
product into flakes the composition.
[0021] In another variation of the design illustrated in FIG. 1,
multiple continuous slurry feed streams may be fed to the
continuous reactor or one slurry feed stream may be fed to multiple
continuous reactors.
[0022] In one embodiment of the present invention, the resinous
material, which may be used as a component in the preparation of a
composition prepared in the present invention, may be prepared by
the process of the present invention in a continuous reactor. The
continuous reactor used for this purpose may be a pipe or tubular
reactor, or an extruder. It is preferred to use an extruder. More
than one such reactor may be used for the preparation of different
resinous materials. Any number of reactors may be used and
optionally any or all of the reactors may be connected directly to
a mixer in which the composition may also be prepared. A pipe or
tubular joint is suitable for use as the means of making such
connection.
[0023] The resinous material useful in the present invention is
prepared by polymerizing one or more monomers and/or oligomers in a
continuous polymerization reactor to form the resinous material,
more specifically a polymer. Typically, a catalyst may be added to
the polymerization reaction mixture for the purpose of obtaining a
specific type of resinous material, or a desired rate of
conversion. The monomer(s), oligomer(s), and catalyst when desired,
may, each separately or in groups of two or more, be fed to the
polymerization reactor in one or more of the following forms: a
liquid solution, a slurry, or a dry physical mixture. However, at
least one or more of the components is fed into the reactor
extruder as a slurry.
[0024] The resinous material from which a composition is prepared
according to the present invention may be virtually any polymer or
copolymer. The resinous material need not have any particular
molecular weight to be useful as a component in the composition.
The resinous material may have repeating units ranging from at
least two repeating units up to those resinous materials whose size
is measured in the hundreds or thousands of repeating units.
Particular resinous materials that may be used in the methods of
the present invention include for example, epoxy resins,
polyesters, urethanes, acrylics and others as set forth in U.S.
Pat. No. 5,094,806, which is incorporated herein by reference. The
most preferred resinous materials useful in the present invention
from among those listed above are epoxy resins and polyesters.
Epoxy resins useful in the present invention, and materials from
which epoxy resins may be prepared, are described in U.S. Pat. No.
4,612,156, which is incorporated herein by reference. Polyesters
useful in the present invention, and materials from which
polyesters may be prepared, are described in Volume 12 of
Encyclopedia of Polymer Science and Engineering, pages 1-313, which
pages are incorporated herein by reference.
[0025] In the production of a resinous material to be used as a
component of a composition of the present invention, various
conditions or parameters have an effect on the course of the
polymerization reaction. Typical examples of these conditions or
parameters are as follows: the rate of feed to the reactor of the
monomer(s) and/or oligomer(s); the temperature at which the
reaction occurs; the length of time during which the reaction
occurs; and the degree to which the reactants are mixed or agitated
during the reaction. The rate of feed of monomer(s) and/or
oligomer(s) can be influenced, for example, by valve adjustment on
a pressured line. The temperature at which the reaction occurs can
be influenced, for example, by the direct heating or cooling of the
monomer(s) and/or oligomer(s) or to the reactor itself. The length
of time during which the reaction occurs can be influenced, for
example, by the size of the reactor, such as the length of a pipe,
tube or extruder, or the speed at which the reactants move into and
out of the reactor, such as may result from the particular speed or
design of an extruder screw, or the introduction of a pressurized
inert gas into a pipe or tube. The degree to which the reactants
are mixed or agitated during the reaction can be influenced, for
example, by the size, shape and speed of blades or other mixing
elements, by the presence of a static mixing element in a pipe or
tube, or the speed of the screw in an extruder.
[0026] The quality of the composition prepared by the process and
apparatus of the present invention is improved if the properties of
the resinous material to be used as a component in the composition
are known and maintained at a desired level. Typical examples of
resinous material properties that may be analyzed for this purpose
are viscosity, melt index, melt flow rate, molecular weight,
molecular weight distribution, equivalent weight, melting point,
glass transition temperature, density, specific gravity, and
purity. For example, when an epoxy resin is used as a resinous
material, it is desired that its viscosity be in the range of from
about 1 to about 100,000 centipoise. The analytical techniques that
may be used to determine resinous material properties such as the
foregoing include ultrasonic wave energy, Raman, infrared, near
infrared, and dielectrics energy. A preferred process and apparatus
for measuring properties of the resinous material used in the
present invention is described in copending U.S. patent
application, Attorney Docked No. 44646 2, entitled "Process And
Apparatus For Preparing A Composition of Matter Utilizing An
Ultrasonic Device", filed by Shawn Maynard, of even date herewith
incorporated herein by reference.
[0027] Generally, the compositions prepared by the slurry process
of the present invention are prepared by continuously feeding a
reactive slurry solution from a slurry vessel to a reactor
extruder. Any number of other ingredients may be added to the
slurry vessel, to the line feed of the reactor or to the reactor to
form a composition. For example, one or more polymers that have not
been prepared in a reactor, reactive or inert compounds, or
additives such as pigments, filler or stabilizer. Optionally, when
the final composition is a blend of materials, the composition from
the reactor extruder may be conveyed from the reactor to a mixer
through a connection between the reactor and the mixer to form a
composition. If more than one reactor is used, a connection is
established between each reactor and the mixer.
[0028] The preferred type of mixer to use is an extruder,
particularly a twin-screw extruder but other types of mixers such
as co-kneaders may be used as well.
[0029] In another embodiment of the present invention, a
composition may be prepared by compounding the resinous material
with other components to prepare a final composition. The remaining
components of the final composition includes a number of other
ingredients which may also include a resinous material, such as an
epoxy or a polyester, or other resinous materials listed above. The
remaining components of the composition may also include
ingredients such as conventional additives for example hardeners
for an epoxy resin (e.g. dicyandiamide), fillers, pigments and
stabilizers. Other additives as ingredients for the composition
prepared by the process and apparatus of the present invention are
disclosed in U.S. Pat. No. 5,416,148, which is incorporated herein
by reference. Such additives may be incorporated as a liquid into
the composition. After mixing the composition in the mixer, the
composition is recovered in a form suitable for handling, such as
in the form of a flake or pellet.
EXAMPLE 1
[0030] Solid epoxy resins were prepared via the reaction of a
liquid epoxy resin and bisphenol A. The feeding of molten bisphenol
A to a reactor extruder was deemed unacceptable for this
application due to color buildup upon shutdown and startup. Thus,
liquid epoxy resin and bisphenol A were fed to a slurry vessel in a
continuous manner at desired flow rates as shown in Table 1 below.
Slurry from the slurry vessel was then continuously fed to a Krupp
Werner & Pfleiderer ZSK-40 reactor extruder using a Moyno.TM.
progressing cavity pump and "The Probe" ultrasonic level
measurement. The epoxide equivalent weight of the product produced
in the reactor was measured over time as indicated in Table 1I.
Consistency of the EEW was acceptable, demonstrating the efficacy
of the slurry feed system. The following table shows the results of
this Example.
1TABLE 1 LER RATE BISPHENOL RATE SAMPLE # TIME (lb/hr) (lb/hr) EEW
#1 1545 101.716 38.284 688.5 #2 1600 101.716 38.284 675.1 #3 1615
101.716 38.284 678.8 #4 1630 101.716 38.284 685.2 #5 1645 101.716
38.284 680.8 #6 1700 101.716 38.284 691.2 #7 1715 101.716 38.284
683.2 #8 1730 101.716 38.284 690.3
* * * * *