U.S. patent application number 13/847781 was filed with the patent office on 2013-08-22 for materials and process for enhancing selective separations.
This patent application is currently assigned to Georgia-pacific Chemicals LLC. The applicant listed for this patent is Georgia-pacific Chemicals LLC. Invention is credited to Pablo G. Dopico, John B. Hines, Brian L. Swift.
Application Number | 20130217791 13/847781 |
Document ID | / |
Family ID | 41066064 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130217791 |
Kind Code |
A1 |
Hines; John B. ; et
al. |
August 22, 2013 |
MATERIALS AND PROCESS FOR ENHANCING SELECTIVE SEPARATIONS
Abstract
Use of a Maillard reaction product as an adjuvant in a variety
of applications including solid-liquid separations, corrosion
inhibition, emulsification, dust suppression, slow release
fertilization, viscosity modification and others and especially as
a depressant or collector in separation processes, including the
selective separation of solids and/or ionic species from aqueous
media, such as in the process of froth flotation.
Inventors: |
Hines; John B.; (Atlanta,
GA) ; Swift; Brian L.; (Oxford, GA) ; Dopico;
Pablo G.; (The Woodlands, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Georgia-pacific Chemicals LLC; |
|
|
US |
|
|
Assignee: |
Georgia-pacific Chemicals
LLC
Atlanta
GA
|
Family ID: |
41066064 |
Appl. No.: |
13/847781 |
Filed: |
March 20, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12479087 |
Jun 5, 2009 |
8425781 |
|
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13847781 |
|
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61059146 |
Jun 5, 2008 |
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Current U.S.
Class: |
516/9 ;
209/4 |
Current CPC
Class: |
C04B 40/0039 20130101;
B03D 1/02 20130101; C05C 9/02 20130101; C22B 3/20 20130101; Y02P
10/234 20151101; B03D 1/01 20130101; C04B 24/12 20130101; Y02P
10/20 20151101; B03D 1/0046 20130101; C04B 2103/0079 20130101; C05G
1/00 20130101; C05C 1/00 20130101; B03D 2201/02 20130101; C05C
9/005 20130101; C04B 40/0039 20130101; C04B 24/10 20130101; C04B
24/12 20130101; C05C 1/00 20130101; C05D 9/02 20130101; C05F 11/02
20130101 |
Class at
Publication: |
516/9 ;
209/4 |
International
Class: |
B03D 1/02 20060101
B03D001/02 |
Claims
1. A process for obtaining a valued material from an aqueous
suspension, dispersion or solution containing the valued material
comprising adding to the aqueous suspension, dispersion or solution
a Maillard reaction product, the Maillard reaction product
comprising an adduct of (1) an amine reactant and (2) a reducing
sugar, a reducing sugar equivalent, or a mixture thereof.
2. A process for emulsifying a material comprising agitating the
material in a liquid in the presence of a Maillard reaction
product, the Maillard reaction product comprising an adduct of (1),
an amine reactant and (2) a reducing sugar, a reducing sugar
equivalent, or a mixture thereof.
3. The process of claim 1, wherein the amine reactant contains at
least one amine functional group, and wherein a molar ratio of the
reducing sugar, the reducing sugar equivalent, or the mixture
thereof to the amine functional group is about 1:1 to about
3:1.
4. The process of claim 1, wherein the reducing sugar, the reducing
sugar equivalent, or the mixture thereof is selected from the group
consisting of: dextrose, fructose, high fructose corn syrup,
erythrulose, ribulose, xylulose, psicose, sorbose, tagatose,
glyceraldehyde, erythrose, threose, ribose, arabinose, xylose,
allose, altrose, mannose, gulose, galactose, talose, maltose,
lactose, furfural, pyruvaldehyde, acetaldehyde, crotonaldehyde,
2-furaldehyde, glycolaldehyde, glycolaldehyde dimer,
trans-3-(2-furyl)acrolein, acrolein, 5-hydroxymethylfurfural,
5-methylfurfural, 4-hydroxycrotonaldehyde, and cinnamaldehyde, and
wherein the amine reactant is selected from the group consisting
of: ammonia, ammonium hydroxide, hydrazine, guanidine, primary
amines, secondary amines, quaternary ammonium compounds,
polyamines, amino acids, and proteins.
5. The process of claim 1, wherein the Maillard reaction product
has a cationic functionality, a sulfur functionality, a phosphorus
functionality, a sulfate functionality, a sulfonate functionality,
a hydroxamic acid functionality, a silane functionality, a phenolic
functionality, or an aza crown chelating functionality.
6. The process of claim 1, wherein the Maillard reaction product is
produced by reacting the amine reactant and the reducing sugar.
7. The process of claim 1, wherein the Maillard reaction product is
produced by reacting the amine reactant, the reducing sugar, and a
non-carbohydrate polyhydroxy reactant.
8. The process of claim 1, wherein the Maillard reaction product is
produced by reacting the amine reactant, the reducing sugar, and a
polycarboxylic acid.
9. The process of claim 1, wherein the valued material is obtained
by sedimentation, filtration, or flotation.
10. The process of claim 1, further comprising recovering the value
material from the aqueous suspension, dispersion or solution after
adding the Maillard reaction product thereto to produce a purified
product, wherein the purified product contains a reduced
concentration of at least one impurity relative to the aqueous
suspension, dispersion, or solution.
11. The process of claim 1, wherein the Maillard reaction product
depresses the value material or an impurity in the aqueous
suspension, dispersion, or solution.
12. The process of claim 1, wherein the Maillard reaction product
promotes flotation of the value material or an impurity in the
aqueous suspension, dispersion or solution.
13. A process for separating a valued material from a suspension,
dispersion, or solution, comprising: treating the liquid
suspension, dispersion, or solution with a Maillard reaction
product of (1) an amine and (2) a reducing sugar, a reducing sugar
equivalent, or a mixture thereof to provide a treated mixture; and
removing a purified valued material from the treated mixture.
14. The process of claim 13, wherein the Maillard reaction product
further comprises a non-carbohydrate polyhydroxy compound or a
polycarboxylic acid.
15. The process of claim 13, wherein the Maillard reaction product
is produced by reacting the amine and the reducing sugar.
16. The process of claim 13, wherein the amine contains at least
one amine functional group, and wherein a molar ratio of the
reducing sugar, the reducing sugar equivalent, or the mixture
thereof to the amine functional group is about 1:1 to about
3:1.
17. The process of claim 13, wherein the reducing sugar, the
reducing sugar equivalent, or the mixture thereof contains an
aldehyde moiety reactive with Cu.sup.+2 to produce a carboxylic
acid moiety.
18. The process of claim 13, wherein the reducing sugar, the
reducing sugar equivalent, or the mixture thereof is selected from
the group consisting of: dextrose, fructose, high fructose corn
syrup, erythrulose, ribulose, xylulose, psicose, sorbose, tagatose,
glyceraldehyde, erythrose, threose, ribose, arabinose, xylose,
allose, altrose, mannose, gulose, galactose, talose, maltose,
lactose, furfural, pyruvaldehyde, acetaldehyde, crotonaldehyde,
2-furaldehyde, glycolaldehyde, glycolaldehyde dimer,
trans-3-(2-furyl)acrolein, acrolein, 5-hydroxymethylfurfural,
5-methylfurfural, 4-hydroxycrotonaldehyde, and cinnamaldehyde, and
wherein the amine is selected from the group consisting of:
ammonia, ammonium hydroxide, hydrazine, guanidine, primary amines,
secondary amines, quaternary ammonium compounds, polyamines, amino
acids, and proteins.
19. The process of claim 13, wherein the Maillard reaction product
depresses the value material or an impurity present in the treated
mixture, or wherein the Maillard reaction product promotes
flotation of the value material or the impurity in the treated
mixture.
20. The process of claim 13, wherein the purified valued material
is removed from the treated mixture by sedimentation, filtration,
or flotation.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional Application of co-pending
U.S. patent application Ser. No. 12/479,087, filed on Jun. 5, 2009,
which claims the benefit of U.S. Provisional Application No.
61/059,146, filed Jun. 5, 2008, each of which is hereby
incorporated by reference in its entirety.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to the use of Maillard
reaction products as adjuvants in a variety of applications,
including in separation processes, and especially in connection
with the selective separation of solids and/or ionic species from
aqueous media, such as in the process of flotation. The invention
also provides novel materials for use in such applications.
[0004] 2. Description of Related Art
[0005] Flotation is a widely used separation process designed for
the recovery or isolation of a valued material present in admixture
in a liquid suspension or dispersion (and especially aqueous
suspensions or dispersions). Separation is accomplished based on
differences in the tendency of various materials to associate with
rising gas (usually air) bubbles.
[0006] Various additives are commonly incorporated into the
flotation liquid (e.g., the aqueous suspension or dispersion) to
improve the selectivity of the separation process.
[0007] For example, substances identified as "collectors" can be
used to chemically and/or physically absorb preferentially onto one
of the substances in the suspension or dispersion (often, though
not always the valued material in the suspension or dispersion) to
render it more hydrophobic and more amenable to flotation.
[0008] Conversely, "depressants," are often used in conjunction
with collectors, to render other materials in the suspension or
dispersion (often though not always the less valued material in the
suspension or dispersion, e.g., gangue) less likely to associate
with the air bubbles, and therefore less likely to be carried into
the froth concentrate and more likely to remain in the underflow or
tailings. Various depressants for improving flotation separations
are known in the art and include guar gum, sodium silicate, starch,
tannins, dextrins, lignosulphonic acids, carboxymethyl cellulose,
cyanide salts and others.
[0009] Because different substances in the suspension or dispersion
are affected differently by the "collector" and/or the
"depressant," a degree of separation is obtained by this
process.
[0010] The manner in which known collectors and depressants achieve
their effect is not understood with complete certainty, and several
theories have been proposed. Depressants, for example may interfere
with or prevent one of the substances in the suspension or
dispersion (such as gangue) from adhering to another of the
substances in the suspension or dispersion (such as a valued
material to be recovered), or the depressant may interfere with or
even prevent the collector(s) from absorbing onto one of the
substances (such as the gangue). Whatever the mechanism, however,
the ability of a depressant to improve the selectivity in a
flotation process can very favorably impact the economics of the
process.
[0011] Flotation is practiced in the beneficiation of a wide
variety of valued materials, including the recovery of minerals
(e.g., phosphorous and potassium) and metal ores (e.g., platinum
group elements), the recovery of high molecular weight hydrocarbons
such as bitumen from sand and/or clay, and the separation of coal
from its ash content to name a few, to obtain the removal of
unwanted contaminants, which are unavoidably co-extracted from
natural deposits, from the valued material.
[0012] In the case of solid ore beneficiation, the use of flotation
generally comprises grinding the crude ore into sufficiently small,
discrete particles and then contacting an aqueous "pulp" of this
ground ore with rising air bubbles, typically while agitating the
pulp. Prior to flotation, the crude ore may be subjected to any
number of preconditioning steps, including selective crushing,
screening, desliming, gravity concentration, electrical separation,
low temperature roasting, and magnetic differentiation.
[0013] In addition to flotation, a number of other processes also
are designed for the separation of solid contaminants from liquid
suspensions or dispersions. Like flotation these other processes
also often take advantage of additives that facilitate the desired
separation, either by destabilizing the suspension or dispersion,
or by otherwise causing contaminants in the suspension or
dispersion to form larger agglomerates. Coagulation, for example,
refers to the destabilization of suspended solid particles, such as
by neutralizing the electric charge that separates them.
Flocculation refers to the bridging or agglomeration of solid
particles together into clumps or flocs, thereby facilitating their
separation by settling or flotation, depending on the density of
the flocs relative to the liquid. Otherwise, filtration may be
employed as a means to separate the larger flocs.
[0014] Flocculants, such as acrylic polymers, find application, for
example, in the separation of solid particles of rock or drill
cuttings from oil and gas well drilling fluids, for agglomerating
clays suspended in the waste slurry effluent from phosphate
production facilities, in coal slurry dewatering, for treating
sewage to remove contaminants (e.g., sludge) via sedimentation, for
processing of pulp and paper mill effluents to remove suspended
cellulosic solids, for removing sand from aqueous
bitumen-containing slurries generated in the extraction and
subsequent processing of oil sands, and for removing suspended
solid particulates in the purification of drinking (i.e., potable)
water.
[0015] The foregoing descriptions are illustrative of specific
examples where an aqueous liquid suspension or dispersion is
processed to recover, isolate, separate, or purify a desired valued
material. Such separations also are common in a number of other
water-consuming industries and the present invention is intended to
be applicable to the wide variety of treatment options designed to
recover, isolate, separate, or purify a desired valued material
from unwanted contaminants. It may also be used to remove unwanted
contaminants from a liquid, such as in water purification.
[0016] In particular, the present invention is directed to the
discovery of a variety of new uses for certain known materials, as
well as to the discovery of new classes of materials which can be
effectively employed in a wide range of applications including, but
not limited to a variety of separation processes, including
flotation. Applicants have determined that the materials of the
present invention have utility as adjuvants for effectively
enhancing the performance of a wide variety of processes, such as
the selective separation of a wide variety of solid contaminants
from liquid suspensions and dispersions.
SUMMARY OF THE INVENTION
[0017] In one embodiment, the present invention is directed to a
process for obtaining a valued material from an aqueous suspension,
dispersion, or solution containing the valued material comprising
adding to the aqueous suspension, dispersion, or solution, a
Maillard reaction product, the Maillard reaction product comprising
an adduct of (1) an amine reactant and (2) a reducing sugar or a
reducing sugar equivalent, or a mixture thereof.
[0018] In one embodiment, the present invention is directed to
specifically to a flotation process for separating a valued
material from an aqueous suspension or dispersion containing the
valued material comprising adding to the aqueous suspension or
dispersion a Maillard reaction product, the Maillard reaction
product comprising an adduct of (1), an amine reactant and (2) a
reducing sugar or a reducing sugar equivalent, or a mixture
thereof.
[0019] In one embodiment, the present invention is directed to a
process for emulsifying a material comprising agitating the
material in a suitable liquid in the presence of a Maillard
reaction product, the Maillard reaction product comprising an
adduct of (1), an amine reactant and (2) a reducing sugar or a
reducing sugar equivalent, or a mixture thereof.
[0020] In one embodiment, the present invention is directed to a
process for reducing corrosion comprising contacting a material in
need of corrosion protection with a Maillard reaction product, the
Maillard reaction product comprising an adduct of (1), an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof.
[0021] In one embodiment, the present invention is directed to a
process for suppressing airborne dust comprising contacting a dust
generating surface with a Maillard reaction product, the Maillard
reaction product comprising an adduct of (1), an amine reactant and
(2) a reducing sugar or a reducing sugar equivalent, or a mixture
thereof.
[0022] In one embodiment, the present invention is directed to a
process of slow release fertilization comprising applying a high
nitrogen containing Maillard reaction product to soil, the high
nitrogen Maillard reaction product comprising an adduct of (1), a
high nitrogen amine reactant and (2) a reducing sugar or a reducing
sugar equivalent, or a mixture thereof.
[0023] In one embodiment, the present invention is directed to a
process for reducing the viscosity of a cementitious slurry
comprising adding a Maillard reaction product to the slurry, the
Maillard reaction product comprising an adduct of (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof.
[0024] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the amine reactant is selected from a
fatty amine.
[0025] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction product has
high cationic functionality.
[0026] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction product has
sulfur functionality.
[0027] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction product has
phosphorus functionality.
[0028] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction product has
sulfate or sulfonate functionality.
[0029] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction product has
hydroxamic acid functionality.
[0030] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction products have
silane functionality.
[0031] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction products have
phenolic functionality.
[0032] In one embodiment, the present invention is directed to
certain Maillard reaction products formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction products have
aza crown chelating functionality.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The present invention is based on the discovery that
Maillard reaction products formed by reacting (1) an amine reactant
and (2) a reducing sugar, a reducing sugar equivalent or a mixture
thereof can effectively be employed as an adjuvant for a wide
variety of applications including, solid-liquid separations,
corrosion inhibition, emulsification, dust suppression, slow
release fertilization, viscosity modification and others. In
particular, the Maillard reaction products have specific utility in
a wide range of separation processes, including flotation, to
promote a selective separation of a wide variety of valued
materials from a wide variety of solid contaminants found in liquid
suspensions or dispersions.
[0034] The separation processes described herein are applicable to
"suspensions" and dispersions as well as to "slurries" of solid
particles. These terms are sometimes defined equivalently and
sometimes are distinguished based on the need for the input of at
least some agitation or energy to maintain homogeneity in the case
of a "slurry." Because the methods of the present invention,
described herein, are applicable broadly to the separation of
solids and solid particles from aqueous media, the terms
"suspension" and "dispersions" are considered interchangeable with
"slurry" (and vice versa) in the present specification and appended
claims.
[0035] In its normal usage, a Maillard reaction is a chemical
reaction between an amino acid (one category of an amine reactant)
and a reducing sugar that often requires added heat to promote the
reaction. It is known to involve a non-enzymatic browning where a
reactive carbonyl group of the reducing sugar reacts with the
nucleophilic amino group of the amino acid. The resulting products
include a wide variety of poorly characterized molecular species,
including certain high molecular weight heterogeneous polymers,
generally identified as melanoidins.
[0036] As noted, the present invention focuses on the use Maillard
reaction products as an adjuvant for a wide variety of applications
including, solid-liquid separations, corrosion inhibition,
emulsification, dust suppression, slow release fertilization,
viscosity modification and others. The Maillard reaction products
are prepared by a reaction between (1) an amine reactant and (2) a
reducing sugar, a reducing sugar equivalent, or a mixture
thereof.
[0037] Broadly, amine reactants suitable for forming Maillard
reaction products used in the present invention include almost any
compound that has one or more reactive amino groups, i.e., an amino
group available for reaction with a reducing sugar, a reducing
sugar equivalent, or a mixture thereof. Compounds which have (or
which function as though they have) more than one reactive amino
group provide more flexibility in the synthesis of useful Maillard
reaction products. Suitable reactive amino groups can be classified
as a primary amino groups (i.e., --NH.sub.2) and secondary amino
groups (i.e., --NHR), where R can be any moiety that does not
interfere with the Maillard reaction.
[0038] Amine reactants thus include ammonia, hydrazine, guanidine,
primary amines (e.g., compounds generally having the formula
NH.sub.2R.sup.1), secondary amines (e.g., compounds generally
having the formula NHR.sup.1R.sup.2), quaternary ammonium compounds
(e.g., compounds generally having a group of the formula
(NH.sub.4).sup.+, (NH.sub.3R.sup.1).sup.+ and
(NH.sub.2R.sup.1R.sup.2).sup.+ and a related anion), polyamines
(compounds having multiple primary and/or secondary nitrogen
moieties (i.e., reactive amino groups) not strictly embraced by the
foregoing formulae), amino acids, and proteins, where R.sup.1 and
R.sup.2 in the amines and quaternary ammonium compounds are each
selected (independently in the case of (NHR.sup.1R.sup.2) and
(NH.sub.2R.sup.1R.sup.2).sup.+) from hydroxyl, alkyl, alkenyl,
alkynyl, cycloalkyl, aryl, heterocyclic, and heteroaryl groups (as
defined hereinafter).
[0039] "Alkyl" (monovalent) when used alone or as part of another
term (e.g., alkoxy) means an optionally substituted branched or
unbranched, saturated aliphatic hydrocarbon group, having up to 25
carbon atoms unless otherwise specified. Examples of particular
unsubstituted alkyl groups include, but are not limited to, methyl,
ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl,
tert-butyl, n-pentyl, 2-methylbutyl, 2,2-dimethylpropyl, n-hexyl,
2-methylpentyl, 2,2-dimethylbutyl, n-heptyl, 3-heptyl,
2-methylhexyl, and the like. The terms "lower alkyl",
"C.sub.1-C.sub.4 alkyl" and "alkyl of 1 to 4 carbon atoms" are
synonymous and used interchangeably to mean methyl, ethyl,
1-propyl, isopropyl, cyclopropyl, 1-butyl, sec-butyl or t-butyl. As
noted, the term alkyl includes both "unsubstituted alkyls" and
"substituted alkyls," (i.e., optionally substituted unless the
context clearly indicates otherwise) the latter of which refers to
alkyl moieties having substituents replacing one or more hydrogens
on one or more (often no more than four) carbon atoms of the
hydrocarbon backbone and generally only one substituent on one or
two carbon atoms. Such substituents are independently selected from
the group consisting of: halo (e.g., I, Br, Cl, F), hydroxy, amino,
cyano, alkoxy (such as C.sub.1-C.sub.6 alkoxy), aryloxy (such as
phenoxy), nitro, carboxyl, oxo, carbamoyl, cycloalkyl, aryl (e.g.,
aralkyls or arylalkyls), heterocyclic, and heteroaryl. Exemplary
substituted alkyl groups include hydroxymethyl, aminomethyl,
carboxymethyl, carboxyethyl, carboxypropyl, acetyl (where the two
hydrogen atoms on the --CH.sub.2 portion of an ethyl group are
replaced by an oxo (.dbd.O), methoxyethyl, and 3-hydroxypentyl.
Particular substituted alkyls are substituted methyl groups.
Examples of substituted methyl group include groups such as
hydroxymethyl, acetoxymethyl, aminomethyl, carbamoyloxymethyl,
chloromethyl, carboxymethyl, carboxyl (where the three hydrogen
atoms on the methyl are replaced, two hydrogens are replaced by an
oxo (.dbd.O) and the other hydrogen is replaced by a hydroxy
(--OH), bromomethyl and iodomethyl.
[0040] "Alkenyl" when used alone or as part of another term means
an optionally substituted unsaturated hydrocarbon group containing
at least one carbon-carbon double bond, typically 1 or 2
carbon-carbon double bonds, and which may be linear or branched.
Representative alkenyl groups include, by way of example, vinyl,
allyl, isopropenyl, but-2-enyl, n-pent-2-enyl, and n-hex-2-enyl. As
noted, the term alkenyl includes both "unsubstituted alkenyls" and
"substituted alkenyls," (i.e., optionally substituted unless the
context clearly indicates otherwise). The substituted versions
refer to alkenyl moieties having substituents replacing one or more
hydrogens on one or more (often no more than four) carbon atoms of
the hydrocarbon backbone and generally only one substituent on one
or two carbon atoms. Such substituents are independently selected
from the group consisting of: halo (e.g., I, Br, Cl, F), hydroxy,
amino, alkoxy (such as C.sub.1-C.sub.6 alkoxy), aryloxy (such as
phenoxy), carboxyl, oxo, cyano, nitro, carbamoyl, cycloalkyl, aryl
(e.g., aralkyls), heterocyclic, and heteroaryl.
[0041] Alkynyl when used alone or as part of another term means an
optionally substituted unsaturated hydrocarbon group containing at
least one carbon-carbon triple bond, typically 1 or 2 carbon-carbon
triple bonds, and which may be linear or branched. Representative
alkynyl groups include, by way of example, ethynyl; 1-, or
2-propynyl; 1-, 2-, or 3-butynyl, or 1,3-butdiynyl; 1-, 2-, 3-,
4-pentynyl, or 1,3-pentdiynyl; 1-, 2-, 3-, 4-, or 5-henynyl, or
1,3-hexdiynyl or 1,3,5-hextriynyl; 1-, 2-, 3-, 4-, 5- or
6-heptynyl, or 1,3-heptdiynyl, or 1,3,5-hepttriynyl; 1-, 2-, 3-,
4-, 5-, 6- or 7-octynyl, or 1,3-octdiynyl, and 1,3,5-octtriynyl. As
noted, the term alkynyl includes both "unsubstituted alkynyl" and
"substituted alkynyl," (i.e., optionally substituted unless the
context clearly indicates otherwise). The substituted versions
refer to alkynyl moieties having substituents replacing one or more
hydrogens on one or more (often no more than four) carbon atoms of
the hydrocarbon backbone and generally only one substituent on one
or two carbon atoms. Such substituents are independently selected
from the group consisting of: halo (e.g., I, Br, Cl, F), hydroxy,
amino, alkoxy (such as C.sub.1-C.sub.6 alkoxy), aryloxy (such as
phenoxy), carboxyl, oxo, cyano, nitro, carbamoyl, cycloalkyl, aryl
(e.g., aralkyls), heterocyclic, and heteroaryl.
[0042] "Cycloalkyl" when used alone or as part of another term
means an optionally substituted saturated or partially unsaturated
cyclic aliphatic (i.e., non-aromatic) hydrocarbon group (carbocycle
group), having up to 12 carbon atoms unless otherwise specified and
includes cyclic and polycyclic, including fused cycloalkyl. As
noted, the term cycloalkyl includes both "unsubstituted
cycloalkyls" and "substituted cycloalkyls," (i.e., optionally
substituted unless the context clearly indicates otherwise) the
latter of which refers to cycloalkyl moieties having substituents
replacing one or more hydrogens on one or more (often no more than
four) carbon atoms of the hydrocarbon backbone and generally only
one substituent on one or two carbon atoms. Such substituents are
independently selected from the group consisting of: halo (e.g., I,
Br, Cl, F), hydroxy, amino, alkoxy (such as C.sub.1-C.sub.6
alkoxy), aryloxy (such as phenoxy), carboxyl, oxo, cyano, nitro,
carbamoyl, alkyl (including substituted alkyls), aryl,
heterocyclic, and heteroaryl. Examples of cycloalkyls include
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
tetrahydronaphthyl and indanyl.
[0043] "Aryl" when used alone or as part of another term means an
optionally substituted aromatic carbocyclic group whether or not
fused having the number of carbon atoms designated or if no number
is designated, from 6 up to 14 carbon atoms. Particular aryl groups
include phenyl, naphthyl, biphenyl, phenanthrenyl, naphthacenyl,
and the like (see e.g. Lang's Handbook of Chemistry (Dean, J. A.,
ed) 13.sup.th ed. Table 7-2 [1985]). Phenyl groups are generally
preferred. As noted, the term aryl includes both "unsubstituted
aryls" and "substituted aryls" (i.e., optionally substituted unless
the context clearly indicates otherwise), the latter of which
refers to aryl moieties having substituents replacing one or more
hydrogens on one or more (usually no more than six) carbon atoms of
the hydrocarbon core and generally only one substituent on one or
two carbon atoms. Such substituents are independently selected from
the group consisting of: halo (e.g., I, Br, Cl, F), hydroxy, amino,
alkoxy (such as C.sub.1-C.sub.6 alkoxy), aryloxy (such as phenoxy),
carboxyl, oxo, cyano, nitro, carbamoyl, alkyl, aryl, heterocyclic
and heteroaryl. Examples of such substituted aryls, e.g.,
substituted phenyls include but are not limited to a mono- or
di(halo)phenyl group such as 2-chlorophenyl, 2-bromophenyl,
4-chlorophenyl, 2,6-dichlorophenyl, 2,5-dichlorophenyl,
3,4-dichlorophenyl, 3-chlorophenyl, 3-bromophenyl, 4-bromophenyl,
3,4-dibromophenyl, 3-chloro-4-fluorophenyl, 2-fluorophenyl; a mono-
or di(hydroxy)phenyl group such as 4-hydroxyphenyl,
3-hydroxyphenyl, 2,4-dihydroxyphenyl, a mono- or di(lower
alkyl)phenyl group such as 4-methylphenyl, 2,4-dimethylphenyl,
2-methylphenyl, 4-(iso-propyl)phenyl, 4-ethylphenyl,
3-(n-propyl)phenyl; a mono or di(alkoxy)phenyl group, for example,
3,4-dimethoxyphenyl, 3-methoxy-4-benzyloxyphenyl,
3-methoxy-4-(1-chloromethyl)benzyloxy-phenyl, 3-ethoxyphenyl,
4-(isopropoxy)phenyl, 4-(t-butoxy)phenyl, 3-ethoxy-4-methoxyphenyl;
3- or 4-trifluoromethylphenyl; a mono- or dicarboxyphenyl or
(protected carboxy)phenyl group such 4-carboxyphenyl; a mono- or
di(hydroxymethyl)phenyl or 3,4-di(hydroxymethyl) phenyl; a mono- or
di(aminomethyl)phenyl or 2-(aminomethyl)phenyl. The aryl groups may
have amine functionality (amino) such that the amine reactant is a
diaminobenzene or diaminobenzene sulfonic acid, diaminotoluene,
diaminonaphthalene, diaminonaphthalene sulfonic acid, and numerous
others.
[0044] "Heterocyclic group", "heterocyclic", "heterocycle",
"heterocyclic", "heterocycloalkyl" or "heterocyclo" alone and when
used as a moiety in a complex group, are used interchangeably and
refer to any cycloalkyl group, i.e., mono-, bi-, or tricyclic,
saturated or unsaturated, non-aromatic and optionally substituted
hetero-atom-containing ring systems having the number of atoms
designated, or if no number is specifically designated then from 5
to about 14 atoms, where the ring atoms are carbon and at least one
heteroatom and usually not more than four (nitrogen, sulfur or
oxygen). Included in the definition are any bicyclic groups where
any of the above heterocyclic rings are fused to an aromatic ring
(i.e., an aryl (e.g., benzene) or a heteroaryl ring). In a
particular embodiment the group incorporates 1 to 4 heteroatoms.
Typically, a 5-membered ring has 0 to 1 double bonds and 6- or
7-membered ring has 0 to 2 double bonds and the nitrogen or sulfur
heteroatoms may optionally be oxidized (e.g. SO, SO.sub.2), and any
nitrogen heteroatom may optionally be quaternized. Particular
non-aromatic heterocycles include morpholinyl(morpholino),
pyrrolidinyl, oxiranyl, indolinyl, isoindolinyl,
tetrahydroquinolinyl, tetrahydroisoquinolinyl, oxetanyl,
tetrahydrofuranyl, 2,3-dihydrofuranyl, 2H-pyranyl,
tetrahydropyranyl, aziridinyl, azetidinyl, 1-methyl-2-pyrrolyl,
piperazinyl and piperidinyl. As noted, the term heterocyclo
includes both "unsubstituted heterocyclos" and "substituted
heterocyclos" (i.e., optionally substituted unless the context
clearly indicates otherwise), the latter of which refers to
heterocyclo moieties having substituents replacing one or more
hydrogens on one or more (usually no more than six) atoms of the
heterocyclo core and generally only one substituent on one or two
carbon atoms. Such substituents are independently selected from the
group consisting of: halo (e.g., I, Br, Cl, F), hydroxy, amino,
alkoxy (such as C.sub.1-C.sub.6 alkoxy), aryloxy (such as phenoxy),
carboxyl, oxo, cyano, nitro, carbamoyl, and alkyl.
[0045] "Heteroaryl" alone and when used as a moiety in a complex
group refers to any aryl group, i.e., mono-, bi-, or tricyclic,
optionally substituted aromatic ring system having the number of
atoms designated, or if no number is specifically designated then
at least one ring is a 5-, 6- or 7-membered ring and the total
number of atoms is from 5 to about 14 and containing from one to
four heteroatoms selected from the group consisting of nitrogen,
oxygen, and sulfur (Lang's Handbook of Chemistry, supra). Included
in the definition are any bicyclic groups where any of the above
heteroaryl rings are fused to a benzene ring. The following ring
systems are examples of the heteroaryl (whether substituted or
unsubstituted) groups denoted by the term "heteroaryl": thienyl
(alternatively called thiophenyl), furyl, imidazolyl, pyrazolyl,
thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl,
thiadiazolyl, oxadiazolyl, tetrazolyl, thiatriazolyl, oxatriazolyl,
pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, thiazinyl, oxazinyl,
triazinyl, thiadiazinyl, oxadiazinyl, dithiazinyl, dioxazinyl,
oxathiazinyl, tetrazinyl, thiatriazinyl, oxatriazinyl,
dithiadiazinyl, imidazolinyl, dihydropyrimidyl,
tetrahydropyrimidyl, tetrazolo[1, 5-b]pyridazinyl and purinyl, as
well as benzo-fused derivatives, for example benzoxazolyl,
benzofuryl, benzothienyl, benzothiazolyl, benzothiadiazolyl,
benzotriazolyl, benzoimidazolyl and indolyl. As noted, the term
heteroaryl includes both "unsubstituted heteroaryls" and
"substituted heteroaryls" (i.e., optionally substituted unless the
context clearly indicates otherwise), the latter of which refers to
heteroaryl moieties having substituents replacing one or more
hydrogens on one or more (usually no more than six) atoms of the
heteroaryl backbone. Such substituents are independently selected
from the group consisting of: halo (e.g., I, Br, Cl, F), hydroxy,
amino, alkoxy (such as C.sub.1-C.sub.6 alkoxy), aryloxy (such as
phenoxy), carboxyl, oxo, cyano, nitro, carbamoyl, and alkyl.
[0046] "Amino" denotes primary (i.e., --NH.sub.2), secondary (i.e.,
--NHR) and tertiary (i.e., --NRR) amine groups, where the R groups
can be a variety of independently selected moieties, usually an
alkyl or an aryl. Particular primary, secondary and tertiary amines
are alkylamine groups, dialkylamine groups, arylamine groups,
diarylamine groups, aralkylamine groups and diaralkylamine
groups.
[0047] Suitable primary, secondary and polyamines amines for use as
the amine reactant include, but are not limited to, methylamine,
ethylamine, propylamine, isopropylamine, ethyl propylamine
benzylamine dimethylamine, diethylamine, dipropylamine,
caprylamine, palmitylamine, dodecylamine, heptylamine,
stearylamine, ethylene diamine, diethylene triamine, triethylene
tetraamine, tetraethylene pentamine, cadaverine, putrescine,
spermine, spermidine, histamine, piperidine, ethanolamine,
diethanolamine, aminoethylpiperazine, piperazine, morpholine,
aniline, 1-naphthylamine, 2-napthylamine, para-aminophenol,
diaminopropane, diaminodiphenylmethane, allylamine, cysteamine,
aminoethylethanol amine, isopropanolamine, toluidine, Jeffamines,
aminophenol, guanidine, aminothiourea, diaminoisophorone,
diaminocyclohexane, dicyandiamide, amylamine, hexamethylenediamine,
bis-hexamethylenediamine, polyvinylamine, polyallylamine,
cyclohexylamine, xylylenediamine disopropylamine,
aminoethylaminopropyltrimethoxysilane, aminopropyltriethoxysilane,
aminoethylaminopropyltrimethoxysilane,
aminoethylaminopropyltrimethoxysilane, aminoethylaminopropylsilane
triol homopolymer,
vinylbenzylaminoethylaminopropyltrimethoxysilane, aminopyridine,
aminosalicylic acid, aminophenol, aminothiophenol, a
minoresorcinol, bis(2-chloroethyl)amine, aminopropanediol,
aminopiperidine, aminopropylphosphonic acid,
amino(ethylsulfonyl)phenol, aminoethylmorpholine,
aminoethylthiadiazole, aminoethyl hydrogen sulfate,
aminopropylimidazole, aminoethylacrylate, polymerized
aminoethylacrylate, aminoethylmethacrylate, polymerized
aminoethylmethacrylate, the condensation polymers and oligomers of
diacids and polyacids with triamines and higher polyamines like
diethylene triamine and triethylene tetraamine.
[0048] Still other amine reactants include furfurylamine,
dipropylene triamine (available from Air Products), tripropylene
tetramine (available from Air Products), tetrapropylene pentamine
(available from Air Products), the reaction products of amines with
formaldehyde including hexamethylene tetraamine,
N,N,N-tri(hydroxyethyl)triazine, triazone, low molecular weight
amino esters like aminoethylacetate, aminopropylacetate,
aminoethylformate, aminopropylformate, aminoethylproprionate,
aminopropylproprionate, aminoethylbutyrate, aminopropylbutyrate,
aminoethylmaleate, di(aminoethylmaleate), fatty aminoesters like
aminoethyltallate, the aminopropyl ester of all fatty acids, fatty
acid dimers, oxidized fatty acids, maleated fatty acid, and
oxidized-maleated fatty acids, and the aminoethyl ester of all
fatty acids, fatty acid dimers, oxidized fatty acids, maleated
fatty acid, and oxidized-maleated fatty acids--particularly when
the fatty acid is tall oil fatty acid (TOFA). Polyamino esters like
the polymer of aminoethylacrylate, the polymer of
aminoethylmethacrylate, the polymer of aminopropylacrylate, the
polymer of aminopropylmethacrylate, and all other polycarboxylic
acids that have been exhaustively esterfied with ethanolamine (done
under acid conditions to selectively form the ester over the
amide.)
[0049] Also contemplated as amine reactants for the Maillard
reaction are amido amine reactions products having residual
reactive amino groups of a diamine or polyamine with a carboxylic
acid or a mixture of carboxylic acids such as rosin acid, maleated
rosin, maleated unsaturated fatty acids, oxidized unsaturated fatty
acids, oxidized maleated unsaturated fatty acids, unsaturated fatty
acid dimers and trimers, particularly when the fatty acid is
TOFA.
[0050] Suitable amine reactants for use in producing a Maillard
reaction product by a Maillard reaction in accordance with the
present invention also include both natural and synthetic amino
acids, i.e., compounds having both reactive amino and acid
(carboxyl) functional groups.
[0051] Suitable amino acids thus would include biogenic amino acids
such as alanine, aminobutyric acid, arginine, asparagine, aspartic
acid, cysteine, cystine, dibromotyrosine, diidotyrosine, glutamic
acid, glutamine, histidine, homocysteine, hydroxylysine,
hydroxyproline, isoleucine, leucine, lysine, methionine, ornithine,
phenylalanine, proline, sarcosine, serine, threonine, thyroxine,
tryptophane, tyrosine, and valine, and all potential dimers,
oligimers and polymers made from such amino acids. Synthetic amino
acids including aminobenzoic acid, aminosalicylic acid,
aminoundecanoic acid and all potential dimers, oligomers and
polymers made from them are likewise suitable raw materials (amine
reactants) for producing a Maillard reaction product by the
Maillard reaction. Higher molecular weight amine reactants include
peptides and proteins including gluten, whey, glutathione,
hemoglobin, soy protein, collagen, pepsin, keratin, and casein as
these materials can also participate in the Maillard reaction.
[0052] Other suitable synthetic amino acid-type amine reactants can
be formed by reacting a polyamine with a polycarboxylic acid or a
mixture of polycarboxylic acids. The reaction between the polyamine
and the acid can be performed prior to, or coincident with the
Maillard reaction.
[0053] Suitable polycarboxylic acids for forming a synthetic amino
acid-type amine reactant by reaction with a polyamine include, but
are not limited to monomeric polycarboxylic acids and/or a
polymeric polycarboxylic acids. Such polycarboxylic acids include
dicarboxylic acids, tricarboxylic acids, tetracarboxylic acids,
pentacarboxylic acids, and higher carboxyl functionality. Certain
polycarboxylic acids also may be used in their anhydride form.
[0054] To illustrate, but not to limit the potential monomeric
polycarboxylic acids that can be used, mention can be made of the
following: unsaturated aliphatic acids, saturated aliphatic acids,
aromatic acids, unsaturated carbocyclic acids, and saturated
carbocyclic acids, all of which might be optionally substituted,
with hydroxy, halo, alkyl, and alkoxy groups. Representative
monomeric polycarboxylic acids thus include, but should not be
limited to citric acid, aconitic acid, adipic acid, azelaic acid,
butane tetracarboxylic acid dihydride, butane tricarboxylic acid,
chlorendic acid, citraconic acid, dicyclopentadiene-maleic acid
adducts, diethylenetriamine pentaacetic acid, adducts of dipentene
and maleic acid, adducts of olefins and maleic acids,
ethylenediamine tetraacetic acid (EDTA), maleated rosin, maleated,
unsaturated fatty acids including maleated tall oil fatty acid,
oxdized unsaturated fatty acids including oxidized tall oil fatty
acid, oxidized maleated unsaturated fatty acids including oxidized
and maleated tall oil fatty acid, unsaturated fatty acid dimer and
trimers (including TOFA dimers and trimers), fumaric acid, glutaric
acid, isophthalic acid, itaconic acid, maleated rosin oxidized with
potassium peroxide to alcohol then carboxylic acid, maleic acid,
malic acid, mesaconic acid, biphenol A or bisphenol F reacted via
the KOLBE-Schmidt reaction with carbon dioxide to introduce 3-4
carboxyl groups, oxalic acid, phthalic acid, sebacic acid, succinic
acid, tartaric acid, terephthalic acid, tetrabromophthalic acid,
tetrachlorophthalic acid, tetrahydrophthalic acid, trimellitic
acid, polyacrylic acid, polymethacrylic acid, polyaspartic acid,
aspartic acid, ascorbic acid, glucaric acid, styrene maleic acid
copolymers, styrene fumaric acid copolymers, polyitaconic acid,
adipic acid, glutamic acid, malonic acid, malic acid, polycrotonic
acid, humic acid, sorbic acid, and trimesic acid.
[0055] Possible polymeric polycarboxylic acids can be equally
expansive and can include homopolymers and/or copolymers prepared
from unsaturated carboxylic acids including, but not necessarily
limited to, acrylic acid, methacrylic acid, crotonic acid,
isocrotonic acid, maleic acid, cinnamic acid, 2-methylmaleic acid,
itaconic acid, 2-methylitaconic acid and
.alpha.,.beta.-methyleneglutaric acid. Suitable polymeric
polycarboxylic acids also may be prepared from unsaturated
anhydrides including, but not necessarily limited to, maleic
anhydride, itaconic anhydride, acrylic anhydride, and methacrylic
anhydride. Non-carboxylic vinyl monomers, such as styrene,
.alpha.-methylstyrene, acrylonitrile, methacrylonitrile, methyl
acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate,
methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate,
glycidyl methacrylate, vinyl methyl ether and vinyl acetate, also
may be copolymerized with above-noted carboxylic acid monomers to
form suitable polymeric polycarboxylic acids. Methods for
polymerizing these monomers are well-known in the chemical art.
[0056] Suitable polymeric polycarboxylic acids also can include
certain polyester adducts of a polycarboxylic acid, such as those
mentioned above, and a polyol. Suitable polyols can include, but
are not limited, for example, to ethylene glycol, glycerol,
pentaerythritol, trimethylol propane, sorbitol, sucrose, glucose,
resorcinol, catechol, pyrogallol, glycollated ureas,
1,4-cyclohexane diol, diethanolamine, triethanolamine,
bis-[N,N-di(.beta.-hydroxyethyl)]adipamide,
bis[N,N-di(.beta.-hydroxypropyl)]azelamide,
bis[N,N-di(.beta.-hydroxypropyl)]adipamide,
bis[N,N-di(.beta.-hydroxypropyl)]glutaramide,
bis[N,N-di(.beta.-hydroxypropyl)]succinamide,
bis[N-methyl-N-(.beta.-hydroxyethyl)]oxamide, polyvinyl alcohol, a
partially hydrolyzed polyvinyl acetate, and homopolymers or
copolymers of hydroxyethyl(meth)acrylate, and
hydroxypropyl(meth)acrylate. The polyester adduct must contain at
least two carboxylic acid groups or anhydride or salt equivalents
thereof. Methods for making such polyesters are well-known
[0057] Another category of suitable amine reactants are the adducts
of ammonia (typically supplied as an aqueous solution), primary
amines, and/or secondary amines pre-reacted (or reacted in situ)
with monomeric polycarboxylic acids and/or polymeric polycarboxylic
acids to produce the respective ammonium salts of the acid or
mixture of acids. While ammonia can conveniently be used, any
reactive amine, including any primary or secondary amine suitable
for reacting with monomeric polycarboxylic acid and/or a polymeric
polycarboxylic acid also could be used.
[0058] Thus, ammonium salts produced by neutralizing polycarboxylic
acid(s)s with ammonia, or with a primary or secondary amine
including those ammonium salts produced by a less-than-complete
neutralization are considered suitable for use as an amine reactant
for making a Maillard reaction product to be used in carrying out a
process in accordance with the present invention. In such
instances, the neutralization of the acid groups of the
polycarboxylic acid(s) also can be carried out either before or
after the reducing sugar, or equivalent thereof is added for
forming the Maillard reaction product.
[0059] The reducing sugar or equivalent thereof for forming the
Maillard reaction product include carbohydrates having, or capable
of generating a reducing sugar during the formation of the Maillard
reaction product. A reducing sugar is a carbohydrate that either
contains an aldehyde group, or can isomerize, i.e., tautomerize, to
contain an aldehyde group, which is reactive with an amine e.g. a
compound having an amino group under Maillard reaction conditions.
Generally, such aldehyde groups can be oxidized with Cu.sup.+2 to
afford carboxylic acids. Suitable reducing sugars or their
equivalents may optionally be substituted with hydroxy, halo,
alkyl, and alkoxy groups. It is common for such compounds to have
one or more chiral centers, and in those circumstances any of the
optical isomers can be used, including racemic mixtures, or other
diastereomeric mixtures of the various optical isomers. Suitable
reducing sugars or their equivalents thus include monosaccharides
in the aldose or ketose form, including a triose, a tetrose, a
pentose, a hexose, or a heptose such as glyceraldehyde,
dihydroxyacetone, erythrose, threose, erythrulose, ribose,
arabinose, xylose, lyxose; ribulose, arabulose, xylulose, lyxulose,
glucose (i.e., dextrose), mannose, galactose, allose, altrose,
talose, gulose, idose; fructose, psicose, dendroketose,
aldotetrose, aldopentose, aldohexose, sorbose, tagatose and
sedoheptulose; a polysaccharide such as sucrose, lactose, maltose,
starch, and cellulose, or a combination thereof.
[0060] In particular, suitable reducing sugars or reducing sugar
equivalents for use in a Maillard reaction for making a Maillard
reaction product include dextrose, fructose, high fructose corn
syrup, dihydroxyacetone, erythrulose, ribulose, xylulose, psicose,
sorbose, tagatose, glyceraldehyde, erythrose, threose, ribose,
arabinose, xylose, allose, altrose, mannose, gulose, galactose,
talose, maltose, cellobiose, lactose, and gentiobiose. Other
reducing sugar equivalents like furfural, pyruvaldehyde,
acetaldehyde, crotonaldehyde, 2-furaldehyde, quinine ascorbic acid,
glycolaldehyde, glycolaldehyde dimer, trans-3-(2-furyl)acrolein,
acrolein, 2,5-di(hydroxymethyl)furan, furfurol,
5-hydroxymethylfurfural, 5-methylfurfurol, 5-methylfurfural,
4-hydroxycrotonaldehyde, cinnamaldehyde and combinations thereof
are also suitable as raw materials for the Maillard reaction.
[0061] The current thinking is that molecules produced by a
Maillard reaction likely include a general structure comprising a
backbone of carbon atoms with an occasional nitrogen atom, possibly
long stretches of conjugated double bonds, and possibly highly
hydrophilic side chains due to hydroxy groups being substituted on
many of the carbon atoms (See "Isolation and Identification of
Nonvolatile. Water Soluble Maillard Reaction Products," Thesis, Eva
Kaminski, McGill University 1997). At least some nitrogen atoms are
thought to be double bonded to one carbon in the backbone and the
existence of carbon side chains substituted on some of the nitrogen
atoms makes some of the nitrogen atoms quaternary, thus often
introducing some cationic character to the molecules.
[0062] Melanoidins typically display an atomic C:N ratio, degree of
unsaturation, and chemical aromaticity that increase with
temperature and time of heating. (See, Ames, J. M. in "The Maillard
Browning Reaction--an update," Chemistry and Industry (Great
Britain), 1988, 7, 558-561, the disclosure of which is hereby
incorporated herein by reference). Accordingly, Maillard reaction
products used in connection with the various applications
contemplated by the present invention, including certain separation
processes, may contain melanoidins, or other Maillard reaction
products consistent with these understandings.
[0063] The present invention also contemplates the addition of a
non-carbohydrate polyhydroxy reactant along with the reducing sugar
or equivalent when preparing the Maillard reaction product.
Non-limiting examples of non-carbohydrate polyhydroxy reactants for
optional use in combination with the reducing sugar or equivalent
for making the Maillard reaction product are trimethylolpropane,
glycerol, pentaerythritol, partially hydrolyzed polyvinyl acetate,
fully hydrolyzed polyvinyl acetate (i.e., polyvinyl alcohol), and
mixtures thereof.
[0064] The preparation of suitable Maillard reaction products is
easily accomplished by mixing (1) an amine reactant and (2) a
reducing sugar or a reducing sugar equivalent, or a mixture thereof
under conditions conducive for a Maillard reaction. The reaction
can be conducted in an aqueous medium and generally proceeds under
a range of pH conditions, though an acidic pH is most commonly
employed. Depending on the specific reactants chosen, the reaction
may proceed under ambient conditions, or may require mild heating
to initiate the reaction. Conducting the reaction in an aqueous
medium under refluxing conditions has proven to be suitable.
Generally, the reaction is sufficiently exothermic that once
initiated, it may not be necessary to supply any additional heating
such that the reaction system becomes self-refluxing.
[0065] While the relative quantities of (1) an amine reactant and
(2) a reducing sugar or a reducing sugar equivalent, or a mixture
thereof for preparing the Maillard reaction product can be varied
depending on particular circumstances, for the most part preparing
the Maillard reaction product at a relative ratio of the moles of
the reducing sugar (or reducing sugar equivalent) to moles of amine
functional groups (reactive amino groups) in the amine reactant
within the range of 1:1 to 3:1 should be suitable.
[0066] Thus, in one embodiment, the reactant mixture for preparing
a Maillard reaction product may comprise an aqueous mixture of an
amine reactant, such as ammonia, a polycarboxylic acid, i.e.,
citric acid, and a reducing sugar, i.e., dextrose provided in a
molar ratio of moles ammonia:moles citric acid:moles dextrose of
3.3:1:6. In this case, a slight excess amount of ammonia (about
10%) designed to completely neutralize the citric acid is provided.
Nonetheless, the volatility of the ammonia may prevent full or
complete neutralization of the citric acid during the formation of
the Maillard reaction product.
[0067] When producing a Maillard reaction product for certain
applications, such as for use in a separation process, it is may be
useful to control the extent of the reaction that occurs. On the
one hand, a simple physical mixture (e.g., an aqueous solution) of
the amine reactant and the reducing sugar or equivalent may not be
an effective adjuvant, e.g. a depressant or a collector. On the
other hand, if the reaction leading to the Maillard reaction
product is allowed to go to dryness, a highly water insoluble,
hard, thermoset material may be formed in some instances. Even if
the resulting solid is comminuted into small particles in such
cases, the material may not be an effective adjuvant. Thus, in some
cases the reaction might need to be controlled to reach a point
where the solution or mixture of the reactants and/or products
becomes viscous but still retains some water solubility,
miscibility and/or remains dispersible in water. The ability of the
Maillard reaction product to function as an adjuvant in a
separation process thus may vary as a function of its molecular
weight.
[0068] The exact desired end point of the reaction forming the
Maillard reaction product will vary depending on its intended end
use and is influenced by a variety of factors, such as the
particular reactants chosen, the reactant concentrations, the
reaction temperature, pH, time, etc. A skilled worker, armed with
the disclosure of this application, through the exercise of only
routine testing will be able to identify a suitable set of
conditions for producing a suitable Maillard reaction product to be
used as an adjuvant for a particular application, including a
specific separation process. Applicants have observed that in the
case of a Maillard reaction product made from aqueous ammonia,
citric acid and dextrose, heating the aqueous mixture to
atmospheric reflux, removing the heat and then allowing it to cool
to room (ambient) temperature has resulted in a suitable product
for use as a depressant. The resulting Maillard reaction product
can be used as an aqueous solution or dispersion and some forms can
be dried (e.g. such as by spray drying) to form a solid
product.
[0069] The pH of the Maillard reaction product in an aqueous medium
may vary from acidic, i.e., a pH less than 7, for example between 2
and 6, to an alkaline pH, i.e., a pH greater than 7, for example
between 8 and 12, depending on the specific types and amounts of
the various reactants. The present invention contemplates
neutralizing, i.e., forming a salt of such acidic and alkaline
Maillard reaction products using an appropriate base or acid
depending on the pH of the reaction product. Such neutralized
products also are contemplated for use as an adjuvant in a
separation process in accordance with the present invention. Thus,
in the case of an acidic reaction product, a base, such as an
alkali or alkaline earth metal hydroxide, (e.g., sodium or
potassium hydroxide), an amine (e.g., a primary, secondary or
tertiary amine such as guanidine), ammonia or some other organic or
inorganic base, may be added to the Maillard reaction product.
Alternatively, in the case of a alkaline reaction product, an acid,
such as an inorganic acid (e.g., hydrochloric acid or sulfuric
acid) or an organic acid (e.g., acetic acid or formic acid), may be
added to the Maillard reaction product to form the neutralized
salt.
[0070] In one embodiment, the present invention is directed to use
of the above-described Maillard reaction products as adjuvants for
removing, generally in a selective fashion, a wide variety of
solids and/or ionic species from liquids, usually water, in which
they are suspended and/or dissolved. These Maillard reaction
products, depending on their specific structure, are especially
useful either as flotation depressants or collectors in the
beneficiation of many types of materials including minerals and
metal ores, in the flotation of dispersed ink particles to de-ink
printed paper pulp, in the beneficiation of kaolin clay and in the
recovery of bitumen from sand and/or clay contaminants to name but
a few flotation applications. Indeed, combinations of such
materials can be used in a single separation system or process, the
distinct materials functioning separately as depressants and as
collections depending on their specific structure.
[0071] For use as an adjuvant in such separation processes,
including the processes identified hereinafter, it is contemplated
that an effective amount of the Maillard reaction product will
usually be between about 0.0001 to 0.1 part by weight of the
Maillard reaction product per part by weight of the total solids
material in the solution, slurry, suspension or dispersion being
treated (e.g., a clay-containing ore slurry). It is anticipated
that in most cases an effective amount of the Maillard reaction
product will usually be between about 0.0005 to 0.05 part by weight
of the Maillard reaction product per part by weight of the total
solids material in the solution, slurry, suspension or dispersion
being treated. In any event, an effective, and particularly an
optimal addition amount of the Maillard reaction product for any
particular solids separation process can be readily ascertained by
those of skill in the art using only routine experimentation.
[0072] In another embodiment, the Maillard reaction products of the
present invention are also useful as an adjuvant for treating
aqueous liquid suspensions (e.g., aqueous suspensions containing
sand, clay, coal, and/or other solids, such as used drill cutting
fluids, as well as process and effluent streams in phosphate and
coal production, in sewage treatment, in paper manufacturing (e.g.,
in a de-inking process), or in bitumen recovery facilities) to
facilitate the removal (such as by, but not limited to
sedimentation, filtration or flotation) of dispersed particles such
as solid particulates and also potentially metallic cations (e.g.,
in the purification of drinking water) using a number of possible
separation processes. The Maillard reaction products depending on
their specific structures, as described herein, are expected to
have selectivity for a variety of dispersed materials, often
considered as contaminants, and especially siliceous materials such
as sand or clay.
[0073] In one separation process, a Maillard reaction product is
used as a depressing agent in a method for beneficiation of an ore
by flotation. The method comprises treating an aqueous slurry of
ore particles with an amount of the Maillard reaction product
effective to depress an impurity selected from, but not limited to,
sand, clay, an iron oxide, a titanium oxide, iron-bearing titania,
mica, ilmenite, tourmaline, an aluminum silicate, calcite,
dolomite, anhydrite, ferromagnesian, feldspar, calcium magnesium
carbonate, igneous rock, soil, and mixtures thereof from the valued
material in the slurry. The valued material could include, but is
not limited to, phosphate, potash, lime, sulfate, gypsum, iron,
platinum, gold, palladium, titanium, molybdenum, copper, uranium,
chromium, tungsten, manganese, magnesium, lead, zinc, clay, coal,
silver, graphite, nickel, bauxite, borax, and borate. The slurry is
treated by simply mixing the Maillard reaction product with the
slurry.
[0074] If the Maillard reaction product is prepared such that it
contains a strongly cationic functionality, such as a
trimethylammonium moiety, the resulting Maillard reaction product
may have enhanced depressant functionality to depress silicates
like clays, micas, talc, feldspar, kaolin, kyanite, muscovite,
calamine, and hemimorphite. Incorporation of the cationic
functionality can be achieved by incorporating choline, betaine,
carnitine, lecithin, imidazolines or their blends as an amine
reactant into the Maillard reaction product synthesis. An
alternative method to incorporate strongly cationic functionality
into the Maillard reaction product is to post-treat a highly amine
functional Maillard reaction product, such as one made with
polyamines, with a strong alkylating agent like methyl bromide,
methyl iodide, dimethylsulfate and diethylsulfate.
[0075] In another embodiment, the Maillard reaction product can be
modified to contain sulfur functionality. A sulfur-modified
Maillard reaction product would have use as a depressant for a
valued ore in a reverse flotation process where the gangue or some
other ore is floated. Incorporation of sulfur functionality in a
Maillard reaction product can be achieved by a variety of methods
including post-reacting an amine functional Maillard reaction
product with carbon disulfide to add thionocarbamate functionality.
Alternatively, the synthesis of the Maillard reaction product could
be conducted in the presence of carbon disulfide, thioglycolic
acid, cysteamine, cysteine, cystine, thioctic acid, methionine
thiourea, or their blends. Another alternative means of adding
sulfur functionality to a Maillard reaction product is simply to
include carbon disulfide in the front end of the Maillard reaction
product synthesis to create xanthate functionality. The resulting
sulfur functional Maillard reaction product then can be used as a
depressant in the reverse flotation of the sulfide mineral ores of
iron, silver, copper, zinc, lead, molybdenum, antimony, bismuth,
gold, arsenic, cobalt, nickel and the platinum group metals.
[0076] For other applications, it may be desirable to incorporate
phosphorus functionality selected from phosphate, phosphonate or
phosphate ester functionality into the Maillard reaction product. A
Maillard reaction product with phosphate, phosphonate or phosphate
ester functionality would be expected to depress minerals with an
affinity for these moieties in a flotation separation process. The
resulting product can be used as a depressant for iron and titanium
containing heavy minerals, biotite, calcite, dolomite, and
magnesite. Incorporation of the phosphate, phosphonate or phosphate
ester functionality can be achieved, for example, by incorporating
aminotrimethylene phosphonate, phosphorus trichloride, phosphorus
pentachloride, phosphonobutane tricarboxylic acid, phosphorus
oxychloride, phosphorus pentoxide, or their blends into the
Maillard reaction product synthesis. An alternative method to
incorporate phosphate, phosphonate or phosphate ester functionality
into the Maillard reaction product is to post-treat one type of
Maillard reaction product with phosphorus trichloride, phosphorus
pentachloride, phosphonobutane tricarboxylic acid, phosphorus
oxychloride, phosphorus pentoxide. Such Maillard reaction products
would also be expected to have corrosion inhibition activity,
especially if the Maillard reaction product is one made using a
fatty amine-type amine reactant as discussed hereafter.
[0077] For still other applications, it may be desirable to
incorporate sulfonate or sulfate functionality into a Maillard
reaction product. A Maillard reaction product with sulfonate or
sulfate functionality would be expected to depress minerals with an
affinity for these moieties in a flotation separation process. Such
functionality is best achieved by the post treatment of a Maillard
reaction product with a sulfite salt, a bisulfite salt, or fuming
sulfuric acid. Alternatively, sulfated or sulfonated reagents such
as aminomethyl sulfonate, aminoethyl hydrogen sulfate, napthylamine
sulfonic acid, sulfanilic acid, aminoethyl hydrogen sulfate,
napthylamine sulfonic acid, sulfamic acid, sulfophthalic acid,
sulfoacetic acid, sulfobenzoic acid, sulfosalicylic acid,
sulfosuccinic acid, diaminobenzene sulfonic acid, taurine or any
blend of those materials could be incorporated into the synthesis
of the Maillard reaction product. Alternately, the Maillard
reaction product could be post-treated with sulfuric acid to add
sulfate functionality to form such sulfonate or sulfate modified
Maillard reaction products. Such Maillard reaction products would
also be expected to have corrosion inhibition activity, especially
if the Maillard reaction product is one made using a fatty
amine-type amine reactant as discussed hereafter.
[0078] In another embodiment, the Maillard reaction product can be
optimized for use as a flotation collector, such as in the reverse
flotation of iron, pyrochlore, and phosphate and in the direct
flotation of clays, micas, talc, feldspar, kaolin, kyanite, potash,
muscovite, calamine, smithsonite, and hemimorphite. In this case,
the amine reactant would be selected to provide sufficient
hydrophobicity for a particular application. For example, the
Maillard reaction product would be made from a fatty amine
reactant, e.g., a primary amine (NH.sub.2R.sup.1) or a secondary
amine (NHR.sup.1R.sup.2), where at least one of the R.sup.1 and
R.sup.2 substituents includes an alkyl chain of at least seven
carbon atoms, such as caprylamine, palmitylamine, dodecylamine,
heptylamine, stearylamine, dodecylaniline, and 11-amino-undecanoic
acid, and also including an amido-amine reaction product of a
diamine or polyamine with rosin acid, maleated rosin, maleated
unsaturated fatty acids, oxdized unsaturated fatty acids, oxidized
maleated unsaturated fatty acids, unsaturated fatty acid dimers and
trimers, particularly where the fatty acid is TOFA. Producing a
Maillard reaction product in this manner facilitates its use as a
flotation collector as the core structure provides a moiety that
binds to a valued mineral and thus connects that mineral to air
bubbles through the fatty tail of the Maillard reaction product,
thus allowing the mineral to float. In using these particular
Maillard reaction product collectors, best results will likely be
obtained when the ratio of amine to other functionality is
relatively high and the pH of the flotation medium is adjusted down
with any number of mineral or organic acids like acetic acid,
formic acid, hydrochloric acid, sulfuric acid, and/or phosphoric
acid, among others, to protonate any active amines.
[0079] By using acid functional fatty raw materials, like adducts
of olefins and maleic acids, maleated unsaturated fatty acids,
oxidized unsaturated fatty acids, oxidized maleated unsaturated
fatty acids, unsaturated fatty acid dimer and trimers and
particularly TOFA based materials, certain ores can be floated
including apatite and other phosphate ores, feldspar, gypsum,
barite, lead oxide ores, lime, celestite, fluorspar, kainite,
anglesite, anhydrite, fluorite, potash, magnesite, scheelite,
alunite, bauxite, gypsum, biotite, dolomite, albite, orthoclase,
microcline, columbite, tantalite, pyrochlore, cassiterite,
wolframite, rutile, ilmenite, hematite, kaolin, and calcite.
[0080] Likewise, if both sulfur and fatty functionality is
incorporated into the Maillard reaction product, the resulting
product can be used as a collector in the flotation of the sulfide
mineral ores of iron, silver, copper, zinc, lead, molybdenum,
antimony, bismuth, gold, arsenic, cobalt, nickel and the platinum
group metals. As noted above, fatty functionality can be introduced
by using fatty amine reactants of by using fatty acid-type
materials to modify the amine reactant. Incorporation of sulfur
functionality is achieved by several methods including
post-reacting fatty amine functional Maillard reaction products
with carbon disulfide to add thionocarbamate functionality,
incorporating carbon disulfide, thioglycolic acid, cysteamine,
cysteine, cystine, thioctic acid, methionine thiourea, or their
blends into the Maillard reaction product synthesis. An alternative
means of adding sulfur functionality is to simply include carbon
disulfide in the front end of the Maillard reaction product
synthesis to create xanthate functionality.
[0081] Alternatively, strongly cationic functionality such as a
trimethylammonium moiety is incorporated into the Maillard reaction
product also containing fatty functionality (as described above),
the resulting product can be used as a collector in the direct
flotation of silicates like clays, micas, talc, feldspar, kaolin,
kyanite, muscovite, calamine, and hemimorphite. As note above,
cationic functionality can be introduced by incorporating choline,
betaine, carnitine, lecithin or their blends into the Maillard
reaction product synthesis. An alternative method to incorporate
strongly cationic functionality is to post-treat a highly amine
functional Maillard reaction product with a strong alkylating agent
like methyl bromide, methyl iodide, dimethylsulfate and
diethylsulfate. Yet another alternative method to incorporate
strongly cationic functionality is to convert amido amine
functionality to imidazoline functionality either in a preceding or
in a post Maillard reaction step.
[0082] Likewise if dithiophosphate and fatty functionality is
incorporated into the Maillard reaction product, the resulting
product can be used as a collector in the flotation of the sulfide
mineral ores of iron, silver, copper, zinc, lead, molybdenum,
antimony, bismuth, gold, arsenic, cobalt, nickel and the platinum
group metals. Such a collector can also be used in the flotation of
diamonds. Incorporation of such functionality may be achieved by
incorporating phosphorus pentasulfide into the Maillard reaction
product synthesis. Dithiophosphate collectors are often used in
combination with collectors containing sulfur functionality. Such
Maillard reaction products would also be expected to have corrosion
inhibition activity.
[0083] In another embodiment, a collector for the direct flotation
of iron and titanium containing heavy minerals, biotite, calcite,
dolomite, magnesite, and fluorspar can be prepared by incorporating
phosphate, phosphonate or phosphate ester functionality into a
Maillard reaction product containing fatty functionality. The
phosphate functional fatty Maillard reaction product collector may
be used in combination with other collectors like amine functional
or carboxylic acid functional collectors. Incorporation of the
phosphate, phosphonate or phosphate ester functionality is achieved
by incorporating aminotrimethylene phosphonate, phosphorus
trichloride, phosphorus pentachloride, phosphonobutane
tricarboxylic acid, phosphorus oxychloride, phosphorus pentoxide,
lecithin or their blends into the Maillard reaction product
synthesis. An alternative method to incorporate phosphate,
phosphonate or phosphate ester functionality is to post-treat a
highly amine functional Maillard reaction product with phosphorus
trichloride, phosphorus pentachloride, phosphonobutane
tricarboxylic acid, phosphorus oxychloride, or phosphorus
pentoxide. Such Maillard reaction products would also be expected
to have corrosion inhibition activity.
[0084] In another embodiment, sulfonate or sulfate functionality
into a fatty Maillard reaction product used as a collector. Such
functionality is best achieved by the post addition of a fatty
Maillard reaction product with a sulfite salt, a bisulfite salt, or
fuming sulfuric acid. Alternatively, sulfated or sulfonated
reagents such as sulfanilic acid, sulfamic acid, sulfophthalic
acid, sulfoacetic acid, sulfobenzoic acid, sulfosalicylic acid,
sulfosuccinic acid, diaminobenzene sulfonic acid, taurine,
aminomethyl sulfonate, aminoethyl hydrogen sulfate, napthylamine
sulfonic acid, or any blend of those materials could be
incorporated into the synthesis of the Maillard reaction product.
Sulfated unsaturated and/or hydroxy functional fatty acids such as
ricinoleic acid can be used as starting materials to make sulfated
Maillard reaction products. These sulfated fatty acids are made by
treating unsaturated and/or hydroxy functional fatty acids with
sulfuric acid. These sulfated fatty acids can be oxidized and/or
maleated prior to incorporation in the Maillard reaction.
Alternately, the Maillard reaction product can be post-treated with
sulfuric acid to add sulfate functionality. The resulting
sulfonated or sulfated Maillard reaction product would be
particularly useful as a collector for biotite, calcite, dolomite,
magnesite, iron oxides, rutile, celestite, gypsum, kainite,
anglesite, bauxite, barite, alunite, fluorspar, anhydrite, and
ilmenite. Such Maillard reaction products would also be expected to
have corrosion inhibition activity.
[0085] In another embodiment, a Maillard reaction product modified
to include hydroxamic acid functionality may be used as a
collector. Such functionality is can be achieved by condensing of
some or all of the fatty acid-type raw materials destined for use
the synthesis of the Maillard reaction product with hydroxylamine
prior to the synthesis of the Maillard reaction product.
Alternatively, hydroxylamine can be condensed with the Maillard
reaction product made with fatty acid-type materials, either in a
post reaction or the hydroxylamine may be included as a raw
material during the synthesis of the Maillard reaction product.
Fatty Maillard reaction products containing hydroxamate
functionality can be used in the flotation of oxide, hydroxide, and
phosphate minerals like Aeschynite, Anatase, Bindheimite, Bixbyite,
Brookite, Chrysoberyl, Columbite, Corundum, Cuprite, Euxenite,
Fergusonite, Hausmannite, Hematite, Ilmenite, Perovskite,
Periclase, Polycrase, Pseudobrookite, Pyrochlore, Betafite,
Microlite, Ramsdellite, Romanechite, Cassiterite, Plattnerite,
Pyrolusite, Rutile, Stishovite, Samarskite, Senarmontite, Chromite,
Franklinite, Gahnite, Magnesiochromite, Magnetite, Spinel,
Taaffeite, Tantalite, Tapiolite, Uraninite, Valentinite, Zincite,
Brucite, Gibbsite, Goethite, Limonite, Manganite, Psilomelane,
Romeite, Stetefeldtite, Carnotite, tyuyamunite, Meta-autunite,
autunite, apatite, phosphuranylite, tobernite, rhabdophane,
triphylite, woodhouseite, Brazilianite, chirchite, lithiophilite,
Hinsdalite, svanbergite, arthurite, cacoxenite, tsumebite,
Variscite, hopeite, meta-ankoleite, scholzite, strengite,
whitlockite, xenotime, amblygonite, kidwellite, laueite,
meta-uranocircite, meta-variscite, montebrasite, pseudomalachite,
rockbridgeite, strunzite, tarbuttite, whiteite, anapaite, augelite,
beraunite, chalcosiderite, collinsite, uranocircite, zeunerite,
boltwoodite, uranophane, meta-torbernite, meta-uranocircite,
walpurgite, zippeite, uranopilite, coconinoite, monazite,
Stibiconite, quetzalcoaltlite, zincite, Hodgkinsonite,
aurichalcite, hydrozincite, rosasite, descloizite, Hopeite,
veszelyite, ktenasite, and gahnite.
[0086] By maximizing the level of fatty carbon and minimizing the
mole ratio of polar groups to alkyl groups, a Maillard reaction
product can be synthesized that would be an excellent collector for
minerals that are currently treated with fuel oil or diesel fuel,
such as coal, oil sands, heavy crude oil, sulfur, feldspar and
phosphate ores like apatite. This result can be achieved by
incorporating alkylphenol formaldehyde condensates and alkoxylated
alkylphenol formaldehyde condensates into the synthesis of the
Maillard reaction product or alternatively, by blending such
condensates with the Maillard reaction product. Another alternative
is to simply adjust the mole ratio of fatty acids or fatty acid
derivatives to the more polar raw materials such as the reducing
sugar. Incorporation of other reactive but relatively non-polar raw
materials like benzaldehyde, aniline, the mono-condensation
products of fatty alcohols and fatty amines with maleic anhydride,
phthalic anhydride, tetrahydrophthalic anhydride, or trimellitic
anhydride, benzylamine, naphthylamine, alkyl and alkenyl succinic
acids, natural oils including vegetable oils, benzoic acid, and
alkyl benzoic acids also provides a suitable approach. Activity can
be increased and cost decreased by post blending such Maillard
reaction products of sufficient hydrophobicity with fuel oil,
diesel, or other nonpolar solvents and additives.
[0087] In another embodiment, the Maillard reaction product can be
modified to contain silane functionality. A silane-modified
Maillard reaction product would have use as a flotation depressant
for silicates. Incorporation of silane functionality in a Maillard
reaction product can be achieved by a variety of methods including
post-reacting a Maillard reaction product with a chloro silane, for
example such as dimethyldichlorosilane, diphenyldichlorosilane,
methylphenyldichlorosilane, methyldichlorosilane,
methyltrichlorosilane, ethyltrichlorosilane, phenyltrichlorosilane,
trichlorosilane, trimethylchlorosilane, vinyltrichlorosilane, or
silicon tetrachloride. Silane modification could also be achieved
by post-treating a Maillard reaction product with an epoxy
functional silane such as glycidoxypropyltrimethoxysilane or
glycidoxypropylmethyldiethoxysilane. Alternatively, an amine
functional silane like aminoethylaminopropyltrimethoxysilane,
aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane,
aminoethylaminopropyltrimethoxysilane, aminoethylaminopropylsilane
triol homopolymer, and
vinylbenzylaminoethylaminopropyltrimethoxysilane could be
incorporated into the synthesis of the Maillard reaction product as
part or all of the reactive amine component. Additionally, an epoxy
silane like glycidoxypropyltrimethoxysilane or
glycidoxypropylmethyldiethoxysilane could be incorporated into the
front end of the Maillard reaction product synthesis. If mercapto
silane functionality is desired then a silane like
mercaptopropyltrimethoxysilane could be incorporated into the
Maillard synthesis.
[0088] Silane modified Maillard reaction product useful as
collectors for silicates may also be obtained by using all the same
silane incorporation techniques used to makes silicate depressants
but incorporating a fatty amine or fatty acid functional ingredient
as describe above would be used in the Maillard reaction product
synthesis.
[0089] Aza-crown ethers and mixed heteroatom crown ethers are often
used to form very specific metal ion chelates. This highly
selective chelating ability, if incorporated into a Maillard
reaction product, may enhance the utility of the resulting material
as a flotation collector or depressant, depending on whether fatty
functionality is also incorporated into the ultimate product. In
yet another embodiment, the Maillard reaction product can be
modified to contain aza crown ether functionality. Flotation
collectors and depressants incorporating aza crown functionality
can be made using the aza crown as all or part of the reactive
amine in a Maillard reaction product synthesis. Whether the
resulting Maillard reaction product would be used as a collector,
or instead used as a depressant would depend on whether fatty alkyl
chains are incorporated into the Maillard reaction product or not.
Suitable aza-crown ethers to use in this application include
1,4,8,11-tetraazacyclotetradecane; 1,5,9-triazacyclododecane;
1,4,7-triazacyclononane; 1,4,7-triazacyclononane tri HCl;
1-Aza-18-crown-6; 1-Aza-15-crown-5; 1,10-diaza-18-crown-6;
1,4,8,11-tetraazacyclotetradecane-5,7-dione and their blends.
Likewise porphyrins made be added in the same way to incorporate
macrocyclic chelating functionality in the Maillard reaction
product.
[0090] Phenols and substituted phenols often form very strong
complexes with certain metal ions like iron. This complex-forming
capability can be incorporated into a Maillard reaction product to
provide the resulting material with utility as a flotation
collector or depressant, depending on whether fatty functionality
is also incorporated during the synthesis. Thus, in yet another
embodiment, the Maillard reaction product can be modified to
contain phenolic functionality. Collectors incorporating phenolic
functionality can be made by condensing a fatty acid with an
aminophenolic compound like aminophenol, aminosalicyclic acid,
aminothiophenol, aminoresorcinol, and amino(ethylsulfonyl) phenol
and using the resulting phenolic fatty amide in the synthesis of a
Maillard reaction product intended for use as a flotation
collector. Likewise the aminophenolic compound can be used as part
or all of the reactive amine component of a Maillard reaction
product intended for use as a flotation collector or depressant,
depending on whether fatty functionality is also incorporated
during the synthesis.
[0091] For other applications, it may be desirable to incorporate a
polysaccharide with the Maillard reaction product. A Maillard
reaction product chemically modified with or possibly blended with
a polysaccharide may be used as a depressant. The polysaccharide
may be added at the front end of the synthesis for chemical
incorporation into the Maillard reaction product, or the
polysaccharide could be incorporated as a physically blended
component with the Maillard reaction product. Suitable
polysaccharides include, for example, starch, cationic starch,
gums, dextrin and their blends.
[0092] In another embodiment, the Maillard reaction product may be
used as an adjuvant in a process for purifying an aqueous liquid
suspension comprising a solid contaminant. Results may be obtained
by adding the Maillard reaction product in an amount between about
0.0001 to 0.1 part by weight of the Maillard reaction product per
part by weight of the total solids material in the suspension. The
method comprises treating (contacting) the liquid suspension with
the Maillard reaction product and removing, either after or during
the treating step, (1) at least a portion of the solid contaminant
in a contaminant-rich fraction and/or (2) a purified liquid. The
treating step may comprise flocculating the solid contaminant
(e.g., sand or clay). The removing step may be accomplished by
sedimentation, flotation, or filtration. Specific applications may
include recovering a purified oil well drilling fluid for reuse in
oil well drilling, recovering a purified water from clay slimes for
reuse in a phosphate recovery operation, dewatering an aqueous coal
slurry, dewatering sewage, dewatering a pulp or paper mill
effluent, or recovering bitumen from sand or clay impurities.
[0093] In another embodiment, the Maillard reaction product could
also be used for purifying water from metallic cation
contamination. The method comprises treating (e.g., contacting) the
water with a Maillard reaction product and removing at least a
portion of the metallic cation by filtration to yield purified
water (e.g., potable water). Removal might be assisted through the
use of membrane filtration.
[0094] In still another embodiment, the Maillard reaction product
could also be used for airborne dust suppression. The Maillard
reaction product can be applied at a concentration of between about
0.01 to 10 percent by weight of the Maillard reaction product. In
particular, a composition of a Maillard reaction product, such as
an aqueous composition, would be applied onto a dust generating
surface in order to reduce airborne dust formation. Such a
composition could be used on roads, on open railcars and trucks
carrying fugitive solids, on conveyer belts, for dirt parking lots,
and other surfaces where airborne dust generation could present a
problem. Maillard reaction products also could be blended or
co-reacted with certain additives to improve performance in such
applications or to lower the overall cost of the composition. Such
additives include crude tall oil, oxidized crude tall oil, fuel
oil, kerosene, heavy oils and waxes, humic acid, tannins,
lignosulfonates, polysaccharides, urea formaldehyde adducts, tall
oil pitch, coal tar pitch, asphalt, fatty acids, oxidized
unsaturated fatty acids, oxidized maleated unsaturated fatty acids,
maleated unsaturated fatty acids, fatty acid dimers, vegetable
oils, animal oils and fats. It also may be desirable for such
applications to incorporate strongly cationic functionality, such
as a trimethylammonium moiety, into the Maillard reaction product
to improve adhesion to dust-forming substrates. As noted above,
incorporation of the cationic functionality can be achieved by
incorporating choline, betaine, carnitine, lecithin, imidazolines
or their blends into the Maillard reaction product synthesis. An
alternative method to incorporate strongly cationic functionality
is to post-treat a highly amine functional Maillard reaction
product such as one made with polyamines with a strong alkylating
agent like methyl bromide, methyl iodide, dimethylsulfate and
diethylsulfate.
[0095] In still another embodiment, the Maillard reaction product
could be used as a slow release fertilizer. In this application,
the Maillard reaction product would be prepared using a high
nitrogen containing amine reactant and/or by forming the Maillard
reaction product at a high mole ratio of amine reactants with the
reducing sugar or equivalent. Preferred amine reactants would
include ammonia, lysine, and guanidine. Preferred reducing sugars
would be those which contribute the least amount of carbon such as
glyceraldehyde and dihydroxyacetone. The Maillard reaction product
also could be blended or co-reacted with certain additives to
provide more nutrient value like manure, urea formaldehyde adducts,
urea, humic acid, ammonium nitrate, potassium phosphate, potassium
nitrate, ammonium phosphate and micronutrients. Soil amendments
like expanded perlite, vermiculite, potting soil, or humic acid
could be co-blended with the product. Likewise pesticides,
nitrification inhibitors and water retaining agents can be blended
with the Maillard reaction product.
[0096] It another embodiment, the Maillard reaction products made
with fatty raw materials (fatty amine reactants, including amine
adducts with fatty acid materials), as described above for use as a
flotation collector, could also be used as an emulsifier. In such
applications, hydrophobic materials can be emulsified in a
hydrophilic vehicle such as water. Alternatively, hydrophilic
materials could be emulsified in a hydrophobic vehicle, such as an
oil. In either case, suitable results may be obtained by adding the
Maillard reaction product in an amount between about 0.0001 to 0.1
part by weight of the Maillard reaction product per part by weight
of the material to be emulsified. Particular applications for using
the Maillard reaction product as an emulsification adjuvant include
oil drilling muds, oil sands processing, asphalt, oil pipelines,
mineral slurry pipelines and other processes requiring
emulsification.
[0097] As noted above, Maillard reaction products made with fatty
amine reactants and/or modified with fatty acid-type materials,
particularly those further modified to introduce other functional
groups such as phosphate, phosphonate, phosphate esters, sulfonate,
sulfate and alkynyl groups could also be used as corrosion
inhibitors. This embodiment provides a process for reducing
corrosion comprising contacting a material in need of corrosion
protection with a Maillard reaction product. Applications amenable
for such treatment include oil drilling, oil sands processing, oil
refinery processing, oil pipelines, mineral slurry pipelines,
chemicals plants, boilers and other processes requiring protection
of metal from corrosion. Incorporation of alkynyl groups into the
Maillard reaction product can be accomplished by using
acetylenedicarboxylic acid as a raw material in the synthesis
reaction. Alternatively acetylene diols can be condensed with
unsaturated fatty acids, oxidized unsaturated fatty acids, maleated
fatty acids and/or oxidized maleated fatty acids and the resulting
condensation product can be incorporated into a Maillard reaction
product. Maillard reaction products having alkynyl groups
incorporated into the Maillard reaction product, particularly those
made from fatty amine reactants, or modified with fatty acid-type
materials, may also be suitable as a flotation collector for
certain minerals.
[0098] In another embodiment, the Maillard reaction product can be
added to a cementitious slurry in order to reduce its viscosity.
Materials which when added to a cementitiuos slurry, such as a
cement slurry or a gypsum slurry, to produce a higher flow at a
lower water usage are known in the art alternatively as dispersing
agents, superplasticizers, water reducing aids and the like.
Functionally, these materials reduce the slurry's viscosity
allowing it to flow more readily. The Maillard reaction products,
especially the fatty Maillard reaction products described above
exhibit this behavior. Thus, the present invention is also directed
to a process for reducing the viscosity of a cementitious slurry
comprising adding a Maillard reaction product to the slurry.
Results may be obtained by adding the Maillard reaction product in
an amount between about 0.0001 to 0.1 part by weight of the
Maillard reaction product per part by weight of the total solids
material in the slurry.
[0099] It will be understood that while the invention has been
described in conjunction with specific embodiments thereof, the
foregoing description and examples are intended to illustrate, but
not limit the scope of the invention. Unless otherwise specifically
indicated, all percentages are by weight. Throughout the
specification and in the claims the term "about" is intended to
encompass + or -5%.
EXAMPLES
Example 1
Preparation of a Maillard Reaction Product for Use as a
Depressant
[0100] A Maillard-like reaction product was prepared according to
the following procedure: 1081 grams of anhydrous dextrose, 194.5
grams of anhydrous citric acid, and 183.8 grams of 28% aqua ammonia
were combined in a reaction vessel and then heated while being
stirred to a target of temperature 85.degree. C. Heating was
terminated when the mixture attained 85.degree. C., but the
exothermic reaction carried the temperature further to nearly
105.degree. C., before the reaction mixture started to cool. No
vacuum was applied to the vessel during the reaction. The final
mixture was a dark-brown syrup, the solids were measured to be 65%
using a microwave CEM set to a maximum temperature of 135.degree.
C. The specific gravity is 1.3.
Example 2
Titration of the Maillard Produced in Example 1 Reaction
Product
[0101] 12.3 grams of the dark-brown syrup produced in Example 1 was
diluted in 98.8 grams of water, where it exhibited a pH of 3.70. A
0.2 N NaOH solution was added to the solution with intermittent pH
testing with a pH probe. 120 ml of the NaOH solution was needed to
neutralize the 12.3 grams and yield a solution having a pH of 8.5.
Adding above this amount of NaOH solution, the pH would be
initially high, but then would fall over time to a pH of .about.9.
To neutralize the solution of the Maillard reaction product with
ammonia to the same degree as was done with 120 ml of NaOH on 12.3
g of syrup, would require about 11.85 grams of 28% aqua ammonia to
100 g of syrup.
Example 3
Neutralization of the Maillard Reaction Product with Aqua
Ammonia
[0102] To 468.6 g of the Maillard reaction product of Example 1 was
added 56 grams of 28% aqua ammonia. The resulting pH was 6.72. The
final solids tested at 65% using a microwave CEM set to a maximum
temperature of 135.degree. C. The specific gravity is 1.3.
Example 4
Neutralization of the Maillard Reaction Product with Guanidine
Carbonate
[0103] 71.9 grams of guanidine carbonate was added to 410.2 grams
of the Maillard reaction product of Example 1. The mixture swelled,
and 200 ml of water was added in two 100 ml aliquots in order to
depress the foam. The resulting mixture had a pH of 6.08 and a
solids content of 53% using a microwave CEM set to a maximum
temperature of 135.degree. C. The specific gravity is 1.22.
Example 5
Preparation of a Maillard Reaction Product of Dextrose and Lysine
for Use as a Depressant
[0104] A Maillard reaction product was prepared according to the
following procedure: 720.56 grams of anhydrous dextrose, 183.67
grams of lysine HCl, 68.3 grams of 28% aqua ammonia, and 392 grams
of water were combined in a reaction vessel and then heated while
being stirred to a target temperature of 85.degree. C. Heating was
terminated when the mixture attained 85.degree. C., but the
exothermic reaction carried the temperature further to nearly
105.degree. C., before the reaction mixture started to cool. Vacuum
was applied to the vessel to facilitate cooling. The final mixture
was a dark-brown syrup, the solids were measured to be 62% by
weight using a microwave CEM set to a maximum temperature of
135.degree. C. The specific gravity is 1.32.
Example 6
Preparation of a Maillard Reaction Product of Dextrose and Betaine
for Use as a Depressant
[0105] A Maillard reaction product was prepared according to the
following procedure: 1080 grams of anhydrous dextrose, 460 grams of
betaine HCl, and 200 grams of 28% aqua ammonia were combined in a
reaction vessel and then heated while being stirred to a target
temperature of 85.degree. C. Heating was terminated when the
mixture attained 85 C, but the exothermic reaction carried the
temperature further to nearly 105.degree. C., before the reaction
mixture started to cool. Vacuum was applied to the vessel to
facilitate cooling. The final mixture was a dark-brown syrup, the
solids were measured to be 61% by weight using a microwave CEM set
to a maximum temperature of 135 C. The specific gravity is
1.23.
Example 7
Evaluation of Maillard Reaction Products from Example 4 as Clay and
Sand Depressants in the Flotation of Athrabasca Oil Sands
[0106] The Maillard reaction products described in Examples 1, 3
and 4 were tested as a clay and sand depressant in the flotation of
Athrabasca Oil Sands using a Denver 2L mechanical flotation machine
(Denver Model D-12). Maillard Reaction Product was added to 950 ml
dionized water such that dosages of 0.1, 0.25 and 0.5 lb/ton of
slurry were obtained. The pH of the solutions were adjusted to 7.3
and the solutions were heated to 50.degree. C. before adding it to
the flotation cell. 450 gm of the oil sands containing 14.2%
bitumen was then added to the flotation cell. The resulting slurry
was conditioned with agitation (1500 rpm) for 2 min. After
conditioning, the air was turned on to a flow rate of 730 ml/min.
Using a spatula, the bitumen froth that was floating on the surface
was scraped off into a collection vessel. The bitumen froth product
was collected, weighed and assayed. The same procedure was repeated
for the baseline measurement except no Maillard reaction product
was added. The following equations were used to calculate the
bitumen recovery, the solids recovery, and the separation
efficiency:
RB=CB/FB.times.100%
RS=CS/FS.times.100%
SE=RB-RS
Where
[0107] RB: Bitumen Recovery, [0108] RS: Solid Recovery, [0109] SE:
Separation Efficiency, [0110] CB: Weight of Bitumen in Concentrate,
[0111] FB: Weight of Bitumen in Feed, [0112] CS: Weight of Solid in
Concentrate, [0113] FS: Weight of Solid in Feed.
[0114] The following table (Table 1) details the flotation
performance with and without the depressant (Rpm: 1500; 50.degree.
C., pH: 7.3; Depressant dosage: 0.1; 0.25 and 0.5 lb/ton; Condition
time: 2 min).
TABLE-US-00001 TABLE 1 Bitumen Solids Separation Dosage Recovery
Recovery Efficiency Depressant (lb/ton) (%) (%) (%) From 0.1 93.51
7.4 86.11 Example 1 0.25 70.86 24.8 46.06 0.5 68.91 22.35 46.57
From 0.1 79.38 9.01 70.37 Example 3 0.25 70.89 22.78 48.11 0.5
68.88 21.44 47.44 From 0.1 88.72 7.77 80.95 Example 4 0.25 96.05
21.89 74.16 0.5 83.49 19.19 64.31 Baseline, no reagent 78.76 27.18
51.58
[0115] As shown in the table, the Maillard reaction products show
improvements in bitumen recovery and separation efficiency over the
baseline containing no reagent, with Example 4 showing the largest
improvement.
Example 8
Evaluation of Maillard Reaction Products from Examples, 1, 3, 4, 5
and 6 as Sand Depressant in the Bitumen Flotation from Oil
Sands
[0116] Table 3 presents the results of separating oil sands using
the Maillard reaction products described in Examples 1, 3, 4, 5 and
6 using a typical flotation cell (e.g., a Denver 2L mechanical
flotation machine (Denver Model D-12)). Oil sand and Maillard
Reaction Product were added to deionized water to obtain a binder
dosage of 0.1 lb/ton of solids. The pH of the solution was adjusted
to 7.3 and the solution was heated to 50.degree. C. before adding
it to the flotation cell. The resulting slurry was conditioned with
agitation (1500 rpm) for 2 min. After conditioning, the air was
turned on to a flow rate of 730 ml/min. Using a spatula, the
bitumen froth that was floating on the surface was scraped off into
a collection vessel. The bitumen froth product was collected,
weighed and assayed. The same procedure was repeated for the
baseline measurement except no Maillard reaction product was added.
The following equations were used to calculate the bitumen
recovery, the solids recovery, and the separation efficiency:
RB=CB/FB.times.100%
RS=CS/FS.times.100%
SE=RB-RS
Where
[0117] RB: Bitumen Recovery, [0118] RS: Solid Recovery, [0119] SE:
Separation Efficiency, [0120] CB: Weight of Bitumen in Concentrate,
[0121] FB: Weight of Bitumen in Feed, [0122] CS: Weight of Solid in
Concentrate, [0123] FS: Weight of Solid in Feed.
[0124] The following table (Table 3) details the flotation
performance.
TABLE-US-00002 TABLE 2 Bitumen Solids Separation Dosage Recovery
Recovery Efficiency Depressant (lb/ton) (%) (%) (%) From 0.1 96.56
8.04 88.52 Example 1 From 0.1 93.38 8.33 85.05 Example 3 From 0.1
92.92 5.85 87.07 Example 4 From 0.1 88.06 7.4 80.67 Example 5 From
0.1 95.46 8.24 87.23 Example 6 Baseline, no reagent 85.29 9.34
75.95
[0125] As shown in the table, the Maillard reaction products of
Examples 1, 3, 4, 5 and 5 showed improvement in bitumen recovery
and separation efficiency at the 0.1 lb/ton dosage over the
baseline containing no reagent.
Example 9
Filtration of High Grade (HG) Oil Sand Using Maillard Reaction
Products from Examples 5 and 6
[0126] Table 3 presents the results of filtering the recovered
solids from the floatation of HG oil sands. HG oil sand and
Maillard Reaction Product were added to process water to obtain a
binder dosage of 0.1 lb/ton of solids. The treated slurry
(approximately 1 L, constituting the contents of a 1L flotation
cell) was vacuum filtered using a Buchner funnel (10.25'' diameter,
with a paper filter, Ahlstrom 6130-3300). The amount of water that
that passed through the filter over time for each test is reported
below in Table 4. The final value represents the water collected
when as much that could be filtered was filtered, and this occurred
at different times for the different runs.
TABLE-US-00003 TABLE 3 Untreated Control Example 5 Example 6
(Baseline) (0.1 lb/ton) (0.1 lb/ton) (cumulative (cumulative
(cumulative Elapsed Filtration grams of grams of grams of Time
(min) filtered water) filtered water) filtered water) 2 5 10 50 4
10 20 142 8 60 40 230 16 188 128 295 32 252 260 368 Complete 388
420 435 Filtration
[0127] The resulting filter cake was also analyzed for its wet
weight and dry weight (by drying overnight in a 300.degree. F.
oven) and then the absolute moisture content and the percentage
moisture was determined. Better performance is indicated by a
larger amount of water passing through the filter, a larger dry
weight of the filter cake and a lower percentage of moisture in the
filter cake.
[0128] The following table (Table 4) details the flotation
performance.
TABLE-US-00004 TABLE 4 Filter Cake Baseline Example 5 Example 6
Property Filter Cake Filter Cake Filter Cake Wet Mass (g) 439.1
462.9 446.5 Dry Mass (g) 343.8 361.6 353.5 Mass Water (g) 95.3
101.3 93 Moisture % 21.7 21.88 20.83
[0129] In another embodiment, the present invention is described
as:
1. A process for obtaining a valued material from an aqueous
suspension, dispersion or solution containing the valued material
comprising adding to the aqueous suspension, dispersion or solution
a Maillard reaction product, the Maillard reaction product
comprising an adduct of (1) an amine reactant and (2) a reducing
sugar, a reducing sugar equivalent, or a mixture thereof. 2. A
flotation process for separating a valued material from an aqueous
suspension or dispersion containing the valued material comprising
adding to the aqueous suspension or dispersion a Maillard reaction
product of (1) an amine reactant and (2) a reducing sugar, a
reducing sugar equivalent, or a mixture thereof. 3. A process for
emulsifying a material comprising agitating the material in a
suitable liquid in the presence of a Maillard reaction product, the
Maillard reaction product comprising an adduct of (1), an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof. 4. A process for reducing corrosion
comprising contacting a material in need of corrosion protection
with a Maillard reaction product, the Maillard reaction product
comprising an adduct of (1), an amine reactant and (2) a reducing
sugar or a reducing sugar equivalent, or a mixture thereof. 5. A
process for suppressing airborne dust comprising contacting a dust
generating surface with a Maillard reaction product, the Maillard
reaction product comprising an adduct of (1), an amine reactant and
(2) a reducing sugar or a reducing sugar equivalent, or a mixture
thereof. 6. A process of slow release fertilization comprising
applying a high nitrogen containing Maillard reaction product to
soil, the high nitrogen Maillard reaction product comprising an
adduct of (1), a high nitrogen amine reactant and (2) a reducing
sugar or a reducing sugar equivalent, or a mixture thereof. 7. A
process for reducing the viscosity of a cementitious slurry
comprising adding a Maillard reaction product to the slurry, the
Maillard reaction product comprising an adduct of (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof. 8. A Maillard reaction product formed by
reacting (1) an amine reactant and (2) a reducing sugar or a
reducing sugar equivalent, or a mixture thereof, wherein the amine
reactant is selected from a fatty amine. 9. A Maillard reaction
product formed by reacting (1) an amine reactant and (2) a reducing
sugar or a reducing sugar equivalent, or a mixture thereof, wherein
the Maillard reaction product has high cationic functionality. 10.
A Maillard reaction product formed by reacting (1) an amine
reactant and (2) a reducing sugar or a reducing sugar equivalent,
or a mixture thereof, wherein the Maillard reaction product has
sulfur functionality. 11. A Maillard reaction product formed by
reacting (1) an amine reactant and (2) a reducing sugar or a
reducing sugar equivalent, or a mixture thereof, wherein the
Maillard reaction product has phosphorus functionality. 12. A
Maillard reaction product formed by reacting (1) an amine reactant
and (2) a reducing sugar or a reducing sugar equivalent, or a
mixture thereof, wherein the Maillard reaction product has sulfate
or sulfonate functionality. 13. A Maillard reaction product formed
by reacting (1) an amine reactant and (2) a reducing sugar or a
reducing sugar equivalent, or a mixture thereof, wherein the
Maillard reaction product has hydroxamic acid functionality. 14. A
Maillard reaction product formed by reacting (1) an amine reactant
and (2) a reducing sugar or a reducing sugar equivalent, or a
mixture thereof, wherein the Maillard reaction product has silane
functionality. 15. A Maillard reaction product formed by reacting
(1) an amine reactant and (2) a reducing sugar or a reducing sugar
equivalent, or a mixture thereof, wherein the Maillard reaction
product has phenolic functionality. 16. A Maillard reaction product
formed by reacting (1) an amine reactant and (2) a reducing sugar
or a reducing sugar equivalent, or a mixture thereof, wherein the
Maillard reaction product has aza crown chelating functionality
[0130] Other aspects, advantages and modifications will be apparent
to those skilled in the art to which the invention pertains, and
these aspects and modifications are within the scope of the
invention, which is limited only by the appended claims.
* * * * *