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Patent 2250432 Summary

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(12) Patent: (11) CA 2250432
(54) English Title: METHOD OF MAKING POLYMERS CONTAINING HYDROXAMATE FUNCTIONAL GROUPS
(54) French Title: PROCEDE DE PRODUCTION DE POLYMERES CONTENANT DES GROUPES A FONCTIONNALITE HYDROXAMATE
Status: Term Expired - Post Grant Beyond Limit
Bibliographic Data
(51) International Patent Classification (IPC):
  • C08F 8/30 (2006.01)
  • B01D 21/01 (2006.01)
  • C08F 8/14 (2006.01)
(72) Inventors :
  • ROTHENBERG, ALAN S. (United States of America)
  • LEWELLYN, MORRIS E. (United States of America)
  • CALBICK, C. JOSEPH (United States of America)
(73) Owners :
  • CYTEC TECHNOLOGY CORP.
(71) Applicants :
  • CYTEC TECHNOLOGY CORP. (United States of America)
(74) Agent: SMART & BIGGAR LP
(74) Associate agent:
(45) Issued: 2006-04-04
(86) PCT Filing Date: 1997-03-26
(87) Open to Public Inspection: 1997-10-09
Examination requested: 2002-03-19
Availability of licence: N/A
Dedicated to the Public: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): Yes
(86) PCT Filing Number: PCT/US1997/004774
(87) International Publication Number: WO 1997036941
(85) National Entry: 1998-09-29

(30) Application Priority Data:
Application No. Country/Territory Date
08/626,297 (United States of America) 1996-04-01

Abstracts

English Abstract


A process is disclosed for the formation of highly anionic hydroxamic acid
polymers whereby (meth)acrylic acid polymers are esterified
in aqueous solution to poly(meth)acrylates. The resultant polymers are then
reacted with an hydroxylamine to produce hydroxamated
(meth)acrylic acid containing polymers. The esterified polymers, their
hydroxamated derivatives and their use to flocculate Bayer Process
streams are also disclosed.


French Abstract

Procédé de formation de polymères d'acide hydroxamique fortement anioniques selon lequel on estérifie des polymère d'acide (méth)acrylique dans une solution aqueuse pour former des poly(méth)acrylates. On fait ensuite réagir les polymères résultant avec une hydroxylamine pour produire des polymères hydroxamatés contenant de l'acide (méth)acrylique. On décrit également dans cette invention les polymères estérifiés, leurs dérivés hydroxamatés et leur utilisation pour floculer des écoulements du procédé Bayer.

Claims

Note: Claims are shown in the official language in which they were submitted.


CLAIMS:
1. A method which comprises esterifying a water-
soluble polymer of an acrylic acid or salt thereof having a
weight average molecular weight of over 1 million in aqueous
solution and hydroxamating the resultant esterified polymer,
wherein the water-soluble polymer is in the dispersed phase
of a water-in-oil emulsion.
2. The method of claim 1, wherein the polymer to be
esterified contains from 5% to 95%, by mole, of the acrylic
acid.
3. The method of claim 1 or 2, wherein the polymer to
be esterified has a weight average molecular weight of at
least 5 million.
4. The method of claim 1 or 2, wherein the polymer to
be esterified has a weight average molecular weight of at
least 10 million.
5. The method of claim 1, 2 or 3, wherein the
esterified polymer is at least 5% esterified.
6. The method of claim 1, 2 or 3, wherein the
esterified polymer is from 5% to 50% esterified.
7. The method of claim 1, 2 or 3, wherein the
esterified polymer is from 10% to 40% esterified.
8. The method of claim 1, 2, 3, 4, 5, 6 or 7, wherein
the hydroxamated polymer is at least 5% hydroxamated.
9. The method of claim 1, 2, 3, 4, 5, 6 or 7, wherein
the hydroxamated polymer is at least 10% hydroxamated.
10. The method of claim 1, 2, 3, 4, 5, 6, 7, 8 or 9,
wherein the acrylic acid is a (meth) acrylic acid.
15

11. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9
or 10, wherein a molar ratio of hydroxylamine to ester
groups is 0.1 to 2Ø
12. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9
or 10, wherein a molar ratio of hydroxylamine to ester
groups is 0.5 to 1.5.
13. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11 or 12, wherein the esterification is achieved by
contacting the water-soluble polymer with an alkylating
agent at a temperature of from 0°C to 80°C.
14. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12 or 13, wherein the hydroxamation is achieved by
contacting the esterified polymer with an hydroxylamine salt
at a pH of at least over 7.0 at a temperature of from 10°C
to 80°C.
15. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13 or 14, wherein the acrylic acid salt is an
ammonium or sodium salt.
16. A water-soluble polymer of a (meth) acrylic acid
and a (meth) acrylic acid ester having a weight average
molecular weight of over 10 million.
17. The polymer according to claim 16, wherein the
(meth) acrylic acid is acrylic acid and the (meth) acrylic
acid ester is methyl acrylate.
18. A hydroxamated, water-soluble polymer of a (meth)
acrylic acid and (meth) acrylic acid ester having a weight
average molecular weight of over 10 million.
16

19. The hydroxamated, water-soluble polymer according
to claim 18 having a molar ratio of hydroxylamine to ester
groups of 0.1 to 2Ø
20. The hydroxamated, water-soluble polymer according
to claim 18 having a molar ratio of hydroxylamine to ester
groups of 0.5 to 1.5.
21. A process for removing suspended solids from a
Bayer alumina process, the improvement comprising contacting
a Bayer Process stream with a hydroxamated, water-soluble
polymer of a (meth) acrylic acid and a (meth) acrylic acid
ester having a weight average molecular weight of at
least 10 million in an amount effective to flocculate the
suspended solids therein and removing the flocculated solids
from the process stream.
22. The process of claim 21, wherein the hydroxamated,
water-soluble polymer has a molar ratio of hydroxylamine to
ester groups of 0.1 to 2Ø
23. The process of claim 21, wherein the hydroxamated,
water-soluble polymer has a molar ratio of hydroxylamine to
ester groups of 0.5 to 1.5.
17

Description

Note: Descriptions are shown in the official language in which they were submitted.


CA 02250432 1998-09-29
WO 97/36941 PCT/LTS97/04774
METHOD OF MAKING POLYMERS CONTAINING
HYDROXAMATE FUNCTIONAL GROUPS
Background of the Invention
The production of hydroxamate group containing polymers has become of
increased
importance in the fast few years, mostly due to the increased use of such
polymers as
flocculants in the Bayer Process for the recovery of alumina. The polymers
have become
accepted worldwide and have virtually replaced the acrylates, especially in
the separation
of red mud in the primary settlers.
Primarily, these hydroxamated polymers have been prepared from acrylamide-
based
polymers by reaction with a hydroxylamine under basic conditions, e.g. a pH of
over about
9, see U.S. Patent Nos. 4,902,751 and 5,128,420.
Other procedures for preparing hydroxamated polymers have also been patented,
see U.S. Patent No. 4,868,248, which discloses the use of polyacrylic acid as
a starting
material instead of an amide polymer. Although this process provides a high
degree of
anionicity to the hydroxamated polymer, the process suffers from various
disadvantages
which renders it less useful from a commercial standpoint in that the reaction
is conducted
under acidic conditions, i.e., a pH of 1-6 and appears to be limited to the
use of rather low
molecular weight polymers.
In U.S. Patent No. 4,767,540, there is disclosed a method whereby acrylic acid-
methyl acrylate copolymers are hydroxamated. The copolymers are disclosed as
being
produced directly from the corresponding monomers, i.e., acrylic acid and
methyl acrylate
and where low amounts of methyl acrylate result in the copolymer, e.g. 10%,
low conversion
of the ester to the hydroxamate is reported. Additionally, because of the
presence of the
acrylate monomer, the molecular weights of the resultant polymers are far
lower than would
be preferred for most applications. Similar low molecular weight polymers are
taught in
U.S. Patent No. 4,587,306 as drilling mud additives.
Although the acrylamide-based hydroxamated polymers have found enormous
success in the marketplace, there still remains certain applications for which
high molecular
weight hydroxamated polymers containing higher levels of acrylic acid moieties
than are
obtainable using previously available processes may be preferred. It was
recognized that
if hydroxamated polymers could be prepared at a high molecular weight and
contain both
hydroxamate groups and acrylic acid groups, both of which have been found to
be effective
in the primary settlers, without the presence of non-ionic acrylamide groups
which are
1

CA 02250432 2005-04-04
75365-147
known to be detrimental therein, a more efficient flocculation of Bayer
Process streams may
be achieved by the user thereof.
While hydroxamation of esters proceeds readily under easily controlled
conditions,
the resultant polymers do not possess a sufficiently high molecular weight so
as to be
commercially attractive because polymerization of acrylic acid esters per se
results in
polymers having molecular weights which are less than those preferred for
flocculation
purposes. See H. L. Cohen, "Journal of Poty Science," Volume 14, pages 7-22
(1976);
Maa, Macromolecules, Volume 22, pages 2036-2039 (1989); Cho, Macromolecules;
Volume
17, pages 2937-2939 (1984). Kern, "Angewandte Chemie" Volume 69, Jahrg. 1957;
Nr. 5
pages 153-171 Hatano, CA 65-15532(g); Renfrow, "Journal of American Chemical
Society,"
Volume 59, pages 2308-2314 (1937).
On the other hand, acrylic acid monomers (or their salts) polymerize readily
to high-
molecular weight polymers but are less easily hydroxamated than the acrylate
esters. See
U.S. Patent No. 4,868,248; Vranken et al, Journal of Poly Science, Volume XIV,
pages 521-
534 (i954), in that acidic conditions are required to be used.
Furthermore, in the hydroxamation of ester group containing polymers, solvents
must
be employed because the polymers are generally not water-soluble, thereby
rendering the
reaction dangerous and environmentally unattractive. The ester group
containing polymers,
because of their insolubility, also cannot be polymerized via water-in-oil
(inverse) emulsion
polymerization, a procedure which is effective for obtaining high molecular
weight polymers,
because the monomers are soluble in the oil phase of the emulsions.
SUMMARY OF THE INVENTION
A novel procedure has now been found whereby high molecular weight, highly
anionic polymers are produced, which polymers contain both acrylate ester and
acrylic acid
linkages, optionally with other pendant groups. The procedure comprises
~esterifying-a high
molecular weight acrylic acid polymer in aqueous solution. The-
resuttant..polymer is then
hydroxamated.
Petrie, Analytical Chemistry, Volume 37, No. 7, pages 919-920, June 1965
teaches
that a hydroxamic acid chelate ion exchange resin can be formed from Ambertite
1RC-50
(a weakly acidic cation exchanger containing 4 percent cross-linkage made from
methacrylic
acid and divinyl benzene) by a process disclosed by Renfrow, Journal of
American
Chemistry Society Volume 59, pages 2308 (1937); however, all reactions are
conducted in
organic solvent solution and no polymerizable monomers are disclosed, much
less
polymers.
*Trade-mark
2

CA 02250432 1998-09-29
- ,
a , _.. "
,
,~ ~ an ns
DESCRIPTION OF THE INVENTION INCLUDING PREFERRED EMBODIMENTS
The present invention relates to a process which comprises esterifying a water-
soluble polymer of a (meth)acrylic acid or salt thereof having a molecular
weight of over one
million in aqueous solution to provide a (meth)acrylic acid alkyl
(meth)acrylate polymer. In
a second phase of the process, the resultant esterified polymer is
hydroxamated.
The instant invention also relates to water-soluble polymers of (meth) acrylic
acid
and a (meth) acrylic acid ester, the polymers having a weight average
molecular weight of
over 10,000,000. Preferably, the polymers are comprised of (meth) acrylic acid
and alkyl
(meth) acrylate units represented by the formula (I):
R
CH-C CH2 ~ Z
2 ~ x I Y ~ ~z
C= O C= O
OH O-R'
wherein each R is, individually, hydrogen or methyl R' is a C,-C4 alkyl group,
Z is the
polymerization residue of a monoethylenically unsaturated monomer
copolymerizable with
(meth) acrylic acid, x ranges from 5 to 95, preferably 10 to 90, y ranges from
5 to 50,
preferably 10 to 40, and z ranges from 0 to 90, preferably 0 to 80.
This invention also relates to hydroxamated polymers of those polymers of
formula
I wherein from 5% to 100% of the ester groups thereof are hydroxamated to
R
-~ C H2 ~ ~ groups
=O
~HOX
wherein X is hydrogen or a cation.
3
AMENDED SME~T

CA 02250432 2005-04-04
75365-147
Also falling within the scope of the present invention is the use of the above-
described hydroxamated polymers in the removal of suspended solids from the
Bayer
alumina process wherein a Bayer Process stream is contacted with the
hydroxamated,
water-soluble polymer of (meth) acrylic ,acid and (meth) acrylic acid ester
having a weight
average molecular weight of at least (preferably over) 10,000,000
in an amount effective to flocculate the suspended solids therein
and the flocculated solids are removed.
The polymers are added to the Bayer Process streams in the form of dilute
aqueous
solutions in an amount at least sufficient to flocculate the suspended solids
therein.
Generally, satisfactory results are achieved when from 0.1 mg of the polymer
per liter of the
process stream are employed, preferably from 1.0 mg of polymer per liter of
process
stream.
Amounts of added polymer may deviate from the above-disclosed amounts and
still
fall within the scope of the present invention as Long as the desired
flocculation is achieved.
The esterification is carried out by' reacting the acrylic acid polymer in
aqueous
solution with an alkylating agent to convert at least a portion of the acrylic
acid groups to
the corresponding esters. Basically, any water-soluble polymer containing
carboxylic acid
groups or their salts can be used in the present process, however, acrylic
acid and
methacrylic acid polymers are preferred. The (meth) acrylic acid polymer
should contain
at least about ~ 0 percent, by weight, of the (meth) acrylic acid, the
remainder being any
monomer copolymerizable therewith which will result in a water-soluble
polymer.
Preferably, the polymer should have at least 25 weight percent of (meth)
acrylic acid
recurring units in its structure, and most preferably the polymer is
homopolymer of (meth)
acrylic acid or salt thereof.
The charge polymers of (meth) acrylic acid should have a molecular inreight of
at
least 1 million, preferably at least 5 million arid most preferably, at least
10 million.
The esterification reaction may be conducted on the polymer of (meth) acrylic
acid
in aqueous solution. By the term "aqueous solution", as used herein, is meant,
solutions
, of the polymer in water, dispersions of the polymer in water, or water-in-
oil emulsions as
described in U.S. Patent Nos. 3,284,393; 5,354,801, in macro or micro sized
micelles of the
aqueous polymer solution. Esterification (and subsequent hydroxamation) of the
polymer
in aqueous solution as a water-in-oil emulsion is preferred.
4

CA 02250432 1998-09-29
, , , ."
. ,,, ~ , - . ,
n w w ' , ,
w a a w a s
Any known alkylating agent may be used to esterify the (meth) acrylic acid
polymer
with dialkyl sulfates such as dimethyl sulfate, diethyl sulfate being
preferred. Other useful
alkylating agents include the alkyl halides such as methyl chloride, ethyl
chloride, allyl
chloride, methyl bromide, methyl iodide; the halohydrins such as
epichlorohydrin; the
alkylene oxides such as ethylene oxide, propylene oxide; 1,2-epoxybutane and
the like.
When the alkyl halides are used in esterifying the (meth) acrylic acid
polymer, catalysts
such as potassium iodide may be used so as to accelerate and improve the
reaction
efficiency. Additionally, those alkylating agents which are gases under the
conditions of the
esterification reaction should be used under pressure.
The esterification reaction is conducted at a temperature ranging from
0° to 80°C,
preferably from 10° to 70°C such as to provide at least 5
percent ester groups in the
resultant polymer, the only criteria being that the resultant esterified
polymer must be either
soluble in the water of the reaction media or reactively dispersed therein.
Preferably,
conversion of the available carboxyl groups of the polymer to ester groups
should result ii-~
from 5-50 percent, most preferably 10-40 percent, of the ester groups in the
resultant
polymer.
The novel process comprising the hydroxamation of the esterified polymer
discussed
above is carried out under at least slightly basic conditions, i.e., at a pH
of at least over 7.0
so as to neutralize the hydroxylamine salt with which the esterified polymer
is reacted. The
slightly basic conditions can be effected by addition of caustic, e.g. NaOH as
is known in
the art, or by the use of a carbonate such as, for example, sodium carbonate.
Temperatures ranging from 10°C to 80°C may be employed and from
at least about
5 percent, by weight, of the available ester groups of the esterified (meth)
acrylic acid
polymer are hydroxamated, preferably at least 10 percent, by weight. Most
preferably, all
the ester groups are hydroxamated. The hydroxamation procedure disclosed in
the above-
referenced U.S. Patent 4,902,751 to Lewellyn et al may be followed for the
hydroxamation
step of the instant process.
Exemplary hydroxylamine salts include the phosphates, perchlorates, sulfates,
sulfites, hydrochlorides, acetates, propionates and the like with the sulfates
being preferred.
Hydroxylamine to ester group mole ratios should range from 0.1 to 2.0,
preferably
0.5 to 1.5.
Examples of monomer which may be copolymerized with the (meth) acrylic acid
monomer to form the polymers which are esterified hereunder and which are
represented
5
AMENDED SHE~fT

CA 02250432 1998-09-29
WO 97/36941 PCT/US97/04774
by recurring unit Z, above, include malefic anhydride, vinyl acetate, vinyl
pyrrolidone,
styrene, acrylamide, methacrylamide, 2-acrylamida-2-methylpropane sulfonic
acid,
acrylonitrile and the like.
The following examples are set forth for purposes of 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.
Exams la a 1
Esterification of a Sodium Polyrjacryrlate) Emulsion with Dimethyl Sulfate
To 300 parts of homopolymeric sodium poiyacrylate oil-continuous emulsion
(21.7%
polymer solids; weight average M.W. range 10 to 20 million) are added 34.2
parts of
dimethyl sulfate (DMS). The reactants are mixed vigorously for 2.5 hours,
after which
Carbon 13 NMR indicates 30% conversion of the carboxylic acid groups to the
methyl ester
in the final emulsion copolymer, representing an essentially quantitative
yield. The weight
average molecular weight remains over 10 million.
Exam lep s 2-8
Using the general procedure described in Example 1, a range of esterified
poly(acrylate) emulsions are prepared, as shown in Table I, below, with
equivalent results.
Table I
Addition Level,% Acid Converted
Example Alkylating AgentMole % to Ester, NMR
2 DMS 2 4
3 DMS 5 6
4 DMS 10 10
5 DMS 15 16
6 DMS 20 19
y
7 DMS 50 43
8 (comp.) DMS 60 emulsion gelled
(comp.) = comparative
6

CA 02250432 1998-09-29
WO 97/36941 PCT/US97/04774
As can be seen, gellation occurs when the ester level gets too high and the
polymer becomes insoluble in the aqueous phase of the emulsion.
Example 9
Esterification of an Ammonium Pc~l ,r(acrylate~ Emulsion with Dimeth~rl
Sulfate
To 300 parts of homopolymeric ammonium poly(acrylate) oil-continuous emulsion
{30% polymer solids; M.W. range 10-20 million) are added 48.3 parts of
dimethyl sulfate.
The mixture is stirred vigorously for 2 hours. Carbon 13 NMR indicates 27%
methyl ester
in the final copolymer of over 10 million weight average molecular weight.
Examples 10-15
Using the general procedure of Example 9, a range of esterified poly(acrylate)
polymers are prepared using dimethyl sulfate (DMS). The results are shown in
Table II,
below, to be substantially equivalent.
Table II
Addition Level,% Acid
Example Alkylating AgentMole % Converted to
10 DMS 5 7
11 DMS 10 11
12 DMS 20 18
13 DMS 50 42
14 DMS 70 53
15 (comp.) DMS 100 product
precipitated
(comp.) = comparative
Again, precipitation {gellation) occurs when the ester polymer becomes
insoluble in
water.
7

CA 02250432 1998-09-29
WO 97/36941 PCT/US97/04774
Exam Ip a 16
Esterification of a Sodium Poly(ac .ryrlate~Emulsion with Meth~rl Chloride
To 300 parts of homopoiymeric sodium poly(acrylate) oil-continuous emulsion
(21.4% polymer solids; M.W. range 10 to 20 million) in a high-pressure
autoclave are added
70.7 parts of methyl chloride. The reaction is heated to 80°C for 2
hours with vigorous
stirring. Carbon 13 NMR indicates 15% methyl ester in the final copolymer of
over 10
million weight average molecular weight.
Examples 17-23
Using the procedure in Example 16, a range of esterified poly(acryiate)
emulsions
are prepared using various alkylating agents. The results are set forth in
Table III, below.
Again, they are substantially equivalent.
Table III
After
Alkylation Reaction 3
Example AIlcylating Level, Temperature Hours-
Agent C Acid
Mole Converted
17 Methyl bromide 20 80 100
18 Methyl bromide 20 80 15
19 Epichlorohydrin20 60 30
20 Propylene Oxide20 90 4 (gel)
21 1,2 Epoxy butane20 100 2 (gel)
22 Allyl Chloride 50 80 7
23 Allyl Chloride 50 100 16 (gel)
Example 24
Esterification of a Sodium Poly~acryrlate) Emulsion with Ethyl Chloride
To 300 parts of homopolymeric sodium poly(acrylate) oil-continuous emulsion
(21.4% polymer solids; M.W. range 10 to 20 million) in a high-pressure
autoclave are added
84 parts of ethyl chloride and 14.9 parts of 10% KI solution. The reaction is
heated to
8

CA 02250432 1998-09-29
WO 97/36941 PCT/US97/04774
100°C for 3 hours with vigorous stirring after which infrared analysis
indicates 16%
esterification resulting in a copolymer of weight average molecular weight
over 10 million.
Exam Ip a 25
Esterification of a Sodium Poly(acrylate) Emulsion with Allyl Chloride
To 300 parts of homopolymeric sodium poly(acrylate) oil-continuous emulsion
{21.4% polymer solids; M.W. range 10 to 20 million) in a high-pressure
autoclave are added
31.8 parts of ally) chloride and 13 parts of 10% KI solution. The reaction is
heated to 80°C
for 2.5 hours with vigorous stirring, after which carbon 13 analysis indicates
7%
esterification. The weight average molecular weight of the copolymer produced
remains
about the same as the charge polymer.
Example 26
Esterification of a Sodium Poly(acr~ fi ate) Emulsion with Epichloroh~rdrin
To 300 parts of homopolymeric sodium poly{acrylate) oil-continuous emulsion
(21.4% polymer solids; M.W. over 10 million) are added 16.5 parts of
epichlorohydrin. After
stirring vigorously for 0.25 hour, the reaction is heated to 60°C
without stirring for 8 hours.
Carbon 13 NMR indicates 30% ester in the final copolymer of about the same
weight
average molecular weight as the charge polymer.
Examlhe 2727
Esterification of a Copolymer Emulsion with Dimethyl Sulfate
To 300 parts of a 50:50 sodium acrylate/acrylamide copolymer oil-continuous
emulsion (24.7% polymer solids; M.W. about 15 million) are added 26 parts of
dimethyl
sulfate {DMS). The mixture is mixed vigorously for 2.5 hours. Carbon 13 NMR
indicates
17% conversion of the carboxylic acid groups to methyl ester in the final
terpolymer,
representing an 85% yield based on DMS. The weight average molecular weight of
the
terpolymer is also about 15 million.
Examples 28-32
The procedure of Example 27 is used to esterify acrylic acid copolymers of
varying
compositions. The results are set forth in Table IV, below.
9

CA 02250432 1998-09-29
WO 97/36941 PCT/US97104774
Table IV
DMS Addition
Example Copolymer Additional Level,% Acid Converted
AA/AMD* Mole to Ester
%
29 10:90 10 10
30 30:70 30 30 (IR)
31 50:50 50 50 (IR)
32 90:10 20 15 (NMR)
33 90:10 30 32 (NMR)
*AA= acrylic acid
AMD = acrylamide
Example 33
Esterification of a Copolymer Emulsion with Methyl Chloride
To 300 parts of a sodium acrylatelacrylamide 50150 copolymer are continuous
emulsion (24.7% polymer solids; M.W. 15 million) in a high-pressure autoclave
added 39.6
parts of methyl chloride and 17.3 parts of 10% KI solution. The reaction is
heated to 80°C
for 3 hours with vigorous stirring. Carbon 13 NMR indicates 14% methyl ester
in the final
terpolymer whose weight average molecular weight is over 15 million.
Example 34
To 300 parts of the emulsion copolymer (30% ester) of Example 1 are added an
aqueous solution containing 63.3 parts of 30% hydroxylamine sulfate, 83 parts
of 50%
sodium hydroxide (100 mole% excess based on total monomer) and 12 parts of
sodium
thiosulfate as a stabilizer. The mixture is mixed vigorously for 1 hour. The
resulting
terpolymer contains 12% hydroxamate according to carbon 13 NMR analysis, 18%
methyl
acrylate and 70% acrylic acid recurring units. The weight average molecular
weight is
virtually unchanged.

CA 02250432 1998-09-29
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~~,., - ",
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o~ ~ oo e~
Examples 35-47
The procedure described in Example 34 is again used to hydroxamate the acrylic
acid/methyl acrylate copolymer of Example 1 under a variety of reaction
stoichiometries.
The results are set forth in the table immediately below.
Moles of
Example Excess HXamine Ester CarboxylateHydroxamat
Caustic*to
-% Ester Group a
35C 0 1.00 30 70 0
36 10 1.00 21 71 8
37 20 1.00 20 72 8
38 25 1.00 12 84 4
39 30 1.00 10 86 4
40 35 1.00 3 89 8
41 40 1.00 0 92 8
42 50 1.00 0 88 12
43 100 0.20 0 96 4
44 100 0.35 0 95 5
45 100 0.50 0 93 7
46 100 1.00 0 88 12
47 100 2.50 0 88 12
*Based on total monomer ,,.
HX = hydroxyl
Exam I
A 90:10 ammonium acrylate/acrylamide copolymer emulsion product (25.4% polymer
solids - weight average M.W. = 11 million) is esterified to the extent of 30%
using dimethyl
sulfate, in accordance with Example 1. To 300 parts of the ester terpolymer
are added an
aqueous reagent solution containing 95.6 parts of 30% hydroxylamine sulfate,
114 parts of
50% sodium hydroxide (100 mole % excess based on total monomer) and 23 parts
of
sodium thiosulfate as a stabilizer. The reaction mixture is agitated
vigorously for 1 hour.
The resulting product contains 9% hydroxamate, 10% amide and 81 % carboxyl
groups
11
AMENDED SHEET

CA 02250432 1998-09-29
WO 97/36941 PCT/US97/04774
according to carbon 13 NMR analysis and has a weight average molecular weight
of about
11 million.
Examples 49-56
The esterified polymers of Examples 17-23, inclusive, are hydroxamated in
accordance with the procedure of Example 34. in each instance, similar results
are
achieved.
Examples 57-66
The hydroxamated polymer of Example 45 is compared with a conventional
commercial polyacrylate red mud flocculant and two commercially available
hydroxamated
polymers derived by hydroxamation of amide polymers. Evaluations are carried
out by first
digesting at elevated temperature and pressure a difficult-to- flocculate
Jamaican bauxite
in alumina plant spent liquor to obtain a slurry containing approximately 100
g/L of mud
solids, and then diluting said slurry with additional spent liquor to provide
a slurry with 40
g/L of mud solids. Portions of the hot slurry are placed in one liter
graduated cylinders and
flocculated by adding thereto varying amounts of the flocculants to be tested
as dilute
aqueous solutions, mixing the added flacculant with the slurry by means of a
perforated
plunger. The settling rate of the mud interface and the clarity of the
supernatant liquor after
mud settling are then measured.
12

CA 02250432 1998-09-29
WO 97/36941 PCT/US97104774
Dosage Settling Clarity,
Example Fiocculant Level, Rate, m/hr.Mg/L
g/T
57C Polyacrylate 234 0.2 >540
58C Commercial Hydroxamate184 20 38
Polymer A
59C Commercial Hydroxamate138 18 45
Polymer A
60C Commercial Hydroxamate92 7 144
Polymer A
61 C Commercial Hydroxamate172 12 6
Polymer B
62C Commercial Hydroxamate128 11 72
Polymer B
63C Commercial Hydroxamate86 5 48
Polymer B
64 Polymer of Example 164 33 14
45
65 Polymer of Example 123 14 6
45
66 Polymer of Example 82 9 22
45
C = comparative
Polymer A = 9% hydroxamation - wt. ave. m.w. 20 million
Polymer B = 18% hydroxamation - wt. ave. m.w. 20 million
Examples 67-80
Hydroxamated polymers of the instant invention are evaluated in the laboratory
using
a red mud slurry from an operating Bayer alumina plant. The laboratory
settling tests are
carried out similarly to those described for Examples 57-66, except that the
hot slurry is
taken from the plant instead of being prepared in a laboratory digestion.
13

CA 02250432 1998-09-29
WO 97/36941 PCT/LTS97/04774
Dosage Settling Clarity,
Example Flocculant Level, Rate, m/hr.Mg/L
g/T
67 Polymer of Example 64 9 124
45
68 Polymer of Example 85 15 100
45
69 Polymer of Example 108 39 112
45
70 Polymer of Example 64 10 121
46
71 Polymer of Example 85 31 137
46
72 Polymer of Example 108 47 121
46
73 Polymer of Example 64 11 154
44
74 Polymer of Example 85 14 161
44
75C Commercial Hydroxamate72 11 126
Polymer A
76C Commercial Hydroxamate97 34 125
Polymer A
77C Commercial Hydroxamate121 77 125
Polymer A
78C Commercial Hydroxamate74 8 71
Polymer C
79C Commercial Hydroxamate92 15 62
Polymer C
80C Commercial Hydroxamate99 28 73
Polymer C
81 C Commercial Hydroxamate124 ~. 45 61
Polymer C
C=comparative
Polymer A = 9% hydroxamation - wt. ave. m.w. 20 million
Polymer C = 14% hydroxamation - wt. ave. m.w. 20 million
14

Representative Drawing

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Administrative Status

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Event History

Description Date
Inactive: IPC expired 2022-01-01
Inactive: Expired (new Act pat) 2017-03-26
Grant by Issuance 2006-04-04
Inactive: Cover page published 2006-04-03
Inactive: Final fee received 2006-01-23
Pre-grant 2006-01-23
Notice of Allowance is Issued 2005-12-15
Letter Sent 2005-12-15
Notice of Allowance is Issued 2005-12-15
Inactive: Approved for allowance (AFA) 2005-07-28
Amendment Received - Voluntary Amendment 2005-04-04
Inactive: S.30(2) Rules - Examiner requisition 2004-10-04
Amendment Received - Voluntary Amendment 2002-08-06
Letter Sent 2002-04-19
Request for Examination Requirements Determined Compliant 2002-03-19
All Requirements for Examination Determined Compliant 2002-03-19
Request for Examination Received 2002-03-19
Inactive: IPC assigned 1998-12-15
Inactive: IPC assigned 1998-12-15
Inactive: IPC assigned 1998-12-10
Classification Modified 1998-12-10
Inactive: First IPC assigned 1998-12-10
Inactive: IPC assigned 1998-12-10
Inactive: Notice - National entry - No RFE 1998-11-26
Application Received - PCT 1998-11-23
Application Published (Open to Public Inspection) 1997-10-09

Abandonment History

There is no abandonment history.

Maintenance Fee

The last payment was received on 2005-12-12

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  • the reinstatement fee;
  • the late payment fee; or
  • additional fee to reverse deemed expiry.

Please refer to the CIPO Patent Fees web page to see all current fee amounts.

Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
CYTEC TECHNOLOGY CORP.
Past Owners on Record
ALAN S. ROTHENBERG
C. JOSEPH CALBICK
MORRIS E. LEWELLYN
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Abstract 1998-09-29 1 46
Description 1998-09-29 14 612
Claims 1998-09-29 1 38
Cover Page 1998-12-16 1 36
Description 2005-04-04 14 615
Claims 2005-04-04 3 91
Cover Page 2006-03-08 1 32
Reminder of maintenance fee due 1998-11-30 1 110
Notice of National Entry 1998-11-26 1 192
Courtesy - Certificate of registration (related document(s)) 1998-11-26 1 114
Reminder - Request for Examination 2001-11-27 1 118
Acknowledgement of Request for Examination 2002-04-19 1 180
Commissioner's Notice - Application Found Allowable 2005-12-15 1 161
PCT 1998-09-29 15 567
Correspondence 2006-01-23 1 37