U.S. patent application number 12/963259 was filed with the patent office on 2011-06-09 for hybrid copolymers.
This patent application is currently assigned to Akzo Nobel N.V.. Invention is credited to Darin K. Griffith, Klin A. Rodrigues.
Application Number | 20110136718 12/963259 |
Document ID | / |
Family ID | 37307281 |
Filed Date | 2011-06-09 |
United States Patent
Application |
20110136718 |
Kind Code |
A1 |
Rodrigues; Klin A. ; et
al. |
June 9, 2011 |
HYBRID COPOLYMERS
Abstract
Hybrid copolymers for use as anti-scalant and dispersant. The
polymers are useful in compositions used in aqueous systems. The
polymers include at least one synthetic monomeric constituent that
is chain terminated by a naturally occurring hydroxyl containing
moiety. A process for preparing these hybrid copolymers is also
provided.
Inventors: |
Rodrigues; Klin A.; (Signal
Mountain, TN) ; Griffith; Darin K.; (Chattanooga,
TN) |
Assignee: |
Akzo Nobel N.V.
Arnhem
NL
|
Family ID: |
37307281 |
Appl. No.: |
12/963259 |
Filed: |
December 8, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12625056 |
Nov 24, 2009 |
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12963259 |
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11458180 |
Jul 18, 2006 |
7666963 |
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12625056 |
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60701380 |
Jul 21, 2005 |
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Current U.S.
Class: |
510/230 ;
252/180; 502/402; 510/337; 510/361; 510/434; 510/471; 524/5;
526/200 |
Current CPC
Class: |
C11D 3/378 20130101;
C08F 220/58 20130101; C08L 51/003 20130101; C02F 2103/18 20130101;
C02F 2303/08 20130101; C08F 2/38 20130101; C02F 2103/002 20130101;
C02F 2103/023 20130101; C08F 291/00 20130101; C08F 265/00 20130101;
C08L 51/003 20130101; C02F 5/10 20130101; C02F 1/285 20130101; C02F
2103/08 20130101; C08F 251/00 20130101; C11D 3/222 20130101; C08F
265/04 20130101; C11D 3/3757 20130101; C08F 265/10 20130101; C02F
2103/28 20130101; C08L 2666/02 20130101; C02F 2305/04 20130101;
C02F 2209/09 20130101; C08F 220/06 20130101; C02F 1/28
20130101 |
Class at
Publication: |
510/230 ;
510/361; 510/337; 510/434; 510/471; 502/402; 252/180; 524/5;
526/200 |
International
Class: |
C11D 3/37 20060101
C11D003/37; C11D 17/00 20060101 C11D017/00; B01J 20/26 20060101
B01J020/26; C02F 5/10 20060101 C02F005/10; C08L 33/08 20060101
C08L033/08; C08F 2/38 20060101 C08F002/38 |
Claims
1.-17. (canceled)
18. A hybrid copolymer comprising: a synthetic polymer comprising
at least one hydrophilic acid monomeric unit wherein the at least
one hydrophilic acid monomeric unit is acrylic acid or methacrylate
acid or salts thereof or mixtures thereof; and a naturally derived
hydroxyl containing chain transfer agent as the end group, wherein
the naturally derived hydroxyl containing chain transfer agent is a
monosaccharide, disaccharide, oligosaccharide or
polysaccharide.
19. The copolymer of claim 18 wherein the at least one hydrophilic
acid monomeric unit further comprises maleic acid, itaconic acid or
salts thereof or mixtures thereof.
20. The copolymer of claim 18 wherein the at least one hydrophilic
acid monomeric unit further comprises 2-acrylamido-2-methyl propane
sulfonic acid or a salt thereof.
21. The copolymer of claim 18 wherein the synthetic polymer
comprises a hydrophobic monomeric unit and a hydrophilic acid
monomeric unit.
22. The copolymer of claim 21 wherein the hydrophobic monomeric
unit is chosen from the group consisting of styrene, a-methyl
styrene, methyl methacrylate, methyl acrylate, 2-ethylhexyl
acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate,
2-ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate,
stearyl methacrylate, behenyl methacrylate and octyl
acrylamide.
23. The copolymer of claim 18 wherein the polysaccharide is chosen
from the group consisting of starch, cellulose, pectin, alginate,
gellan, gums and modified starch.
24. The copolymer of claim 23 wherein the starch is chosen from the
group consisting of maize, potato, tapioca, wheat, rice, pea, sago,
oat, barley, rye and amaranth.
25. The copolymer of claim 24 wherein the starch is chosen from the
group consisting of waxy starch, high amylose starch, maltodextrins
and oxidized starch.
26. A formulation comprising: (a) a hybrid copolymer comprising:
(i) a synthetic polymer comprising at least one hydrophilic acid
monomeric unit wherein the at least one hydrophilic acid monomeric
unit is acrylic acid or a salt thereof, and (ii) a naturally
derived hydroxyl containing chain transfer agent as the end group,
wherein the naturally derived hydroxyl containing chain transfer
agent is a monosaccharide, disaccharide, oligosaccharide or
polysaccharide; and (b) at least one adjunct ingredient.
27. The formulation of claim 26 wherein the formulation is selected
from the group consisting of a cleaning, superabsorbent, fiberglass
binder, rheology modifier, oil field, water treatment, dispersant
and a cement formulation.
28. The formulation of claim 27 wherein the cleaning formulation is
a detergent, fabric cleaner, automatic dishwashing detergent, glass
cleaner, hard surface cleaner or a laundry detergent.
29. The formulation of claim 28 wherein the automatic dishwashing
detergent is a non-phosphate formulation.
30. The formulation of claim 26 wherein the adjunct ingredient is
selected from the group consisting of water, surfactants, builders,
phosphates, sodium carbonate, citrates, enzymes, buffers, perfumes,
anti-foam agents, ion exchangers, alkalis, anti-redeposition
materials, optical brighteners, fragrances, dyes, fillers,
chelating agents, fabric whiteners, brighteners, sudsing control
agents, solvents, hydrotropes, bleaching agents, bleach precursors,
buffering agents, soil removal agents, soil release agents, fabric
softening agent, opacifiers, water treatment chemicals, corrosion
inhibitors, orthophosphates, zinc compounds, tolyltriazole,
minerals, clays, salts, metallic ores, metallic oxides, talc,
pigments, titanium dioxide, mica, silica, silicates, carbon black,
iron oxide, kaolin clay, modified kaolin clays, calcium carbonate,
phosphonates, synthetic calcium carbonates, fiberglass, cement and
aluminum oxide.
31. The method of cleaning of claim 30 wherein the adjunct
ingredient is selected from the group consisting of water,
surfactants, builders, phosphates, sodium carbonate, citrates,
enzymes, buffers, perfumes, anti-foam agents, ion exchangers,
alkalies, anticorrosion materials, anti-redeposition materials,
optical brighteners, fragrances, dyes, fillers, chelating agents,
fabric whiteners, brighteners, sudsing control agents, solvents,
hydrotropes, bleaching agents, bleach precursors, buffering agents,
soil removal agents, soil release agents, phosphonates, fabric
softening agents and opacifiers.
32. The method of controlling scale of claim 31 wherein the scale
controlled is carbonate, sulfate, phosphate or silicate based
scales.
33. A method for dispersing particulates in an aqueous system, the
method comprising adding to the aqueous system the hybrid copolymer
according to claim 18 in an amount sufficient to disperse the
particulates.
34. The method of dispersing particulates of claim 33 wherein the
particulates are minerals, clays, salts, metallic ores, metallic
oxides, dirt, soils, talc, pigments, titanium dioxide, mica,
silica, silicates, carbon black, iron oxide, kaolin clay, calcium
carbonate, synthetic calcium carbonates, precipitated calcium
carbonate, ground calcium carbonate, precipitated silica, kaolin
clay or combinations thereof.
35. The copolymer of claim 18 wherein the synthetic polymer is
present at between 25 and 99.9 percent by weight of the
copolymer.
36. A hybrid copolymer formed by combining at least one hydrophilic
acid monomer with a solution of a naturally derived hydroxyl
containing chain transfer agent and an initiator that is not a
metal based redox system at a temperature effective to activate the
initiator, wherein the at least one hydrophilic acid monomer is
acrylic acid, methacrylic acid or salts thereof or mixtures
thereof, and wherein the naturally derived hydroxyl containing
chain transfer agent is a monosaccharide, disaccharide,
oligosaccharide or polysaccharide.
37. The hybrid copolymer of claim 36 wherein the initiator is
persulfate.
38. The hybrid copolymer of claim 36 wherein the at least one
hydrophilic acid monome further comprises maleic acid, itaconic
acid or salts thereof or mixtures thereof.
39. The hybrid copolymer of claim 36 wherein the at least one
hydrophilic acid monomer further comprises 2-acrylamido-2-methyl
propane sulfonic acid or a salt thereof.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/701,380, filed 21 Jul. 2005.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention. The present invention relates to
hybrid copolymers of synthetic and naturally derived materials.
More particularly, the present invention is directed towards chain
transfer agents formed from hydroxyl-containing naturally derived
materials for use during production of synthetic polymers to
produce those hybrid copolymers. The present invention also relates
to anti-scalant and/or dispersant formulations or compositions
including such polymers and their use in aqueous systems, including
scale minimization.
[0003] Background Information. Many aqueous industrial systems
require various materials to remain in a soluble, suspended or
dispersed state. Examples of such aqueous systems include boiler
water or steam generating systems, cooling water systems, gas
scrubbing systems, pulp and paper mill systems, desalination
systems, fabric, dishware and hard surface cleaning systems, as
well as downhole systems encountered during the production of gas,
oil, and geothermal wells. Often the water in those systems either
naturally or by contamination contains ingredients such as
inorganic salts. These salts can cause accumulation, deposition,
and fouling problems in aqueous systems such as those mentioned
above.
[0004] Inorganic salts are typically formed by the reaction of
metal cations (e.g., calcium, magnesium or barium) with inorganic
anions (e.g., phosphate, carbonate or sulfate). When formed, the
salts tend to be insoluble or have low solubility in water. As
their concentration in solution increases or as the pH and/or
temperature of the solution containing those salts changes, the
salts can precipitate from solution, crystallize and form hard
deposits or scale on surfaces. Such scale formation is a problem in
equipment such as heat transfer devices, boilers, secondary oil
recovery wells, and automatic dishwashers, as well as on substrates
washed with such hard waters, reducing the performance and life of
such equipment.
[0005] In addition to scale formation many cooling water systems
made from carbon steel, including industrial cooling towers and
heat exchangers, experience corrosion problems. Attempts to prevent
this corrosion are often made by adding various inhibitors such as
orthophosphate and/or zinc compounds to the water. However,
phosphate addition increases the formation of highly insoluble
phosphate salts such as calcium phosphate. The addition of zinc
compounds can lead to precipitation of insoluble salts such as zinc
hydroxide and zinc phosphate.
[0006] Other inorganic particulates such as mud, silt and clay can
also be commonly found in cooling water systems. These particulates
tend to settle onto surfaces, thereby restricting water flow and
heat transfer unless they are effectively dispersed.
[0007] Stabilization of aqueous systems containing scale-forming
salts and inorganic particulates involves a variety of mechanisms.
Inhibition is one conventional mechanism for eliminating the
deleterious effect of scale-forming salts. In inhibition, synthetic
polymer(s) are added that increase the solubility of the
scale-forming salt in the aqueous system.
[0008] Another stabilization mechanism is the dispersion of
precipitated salt crystals. Synthetic polymers having carboxylic
acid groups function as good dispersants for precipitated salts
such as calcium carbonates. In this mechanism, the crystals stay
dispersed rather than dissolving in the aqueous solution.
[0009] A third stabilization mechanism involves interference and
distortion of the crystal structure of the scale by the polymer,
thereby making the scale less adherent to surfaces, other forming
crystals and/or existing particulates.
[0010] Synthetic polymers can also impart many useful functions in
cleaning compositions. For example, they can function either
independently or concurrently as viscosity reducers in processing
powdered detergents. They can also serve as anti-redeposition
agents, dispersants, scale and deposit inhibitors, crystal
modifiers, and/or detergent assistants capable of partially or
completely replacing materials used as builders while imparting
optimum detergent action properties to surfactants.
[0011] Cleaning formulations contain builders such as phosphates
and carbonates for boosting their cleaning performance. These
builders can precipitate out insoluble salts such as calcium
carbonate and calcium phosphate in the form of calcium
orthophosphate. The precipitants form deposits on clothes and
dishware that results in unsightly films and spots on these
articles. Similarly, insoluble salts cause major problem in down
hole oil field applications. Hence, there is a need for polymers
that will minimize the scaling of insoluble salts in water
treatment, oil field and cleaning formulations.
[0012] Synthetic polymers have been used to minimize scale
formation in aqueous treatment systems for a number of years.
However, there has been a shortage of monomers to produce these
synthetic polymers lately due to rising demand and tight crude oil
supplies. Hence, there is a need to replace these synthetic
polymers with hybrid polymers that are at least partially derived
from renewal natural sources. Also, polymers from renewal natural
sources should have a better biodegradable profile than synthetic
polymers, which tend to have very little biodegradability.
[0013] A number of attempts have been made in the past to use
natural materials as polymeric building blocks. These have mainly
centered on grafting natural materials like sugars and starches
with synthetic monomers. For example, U.S. Pat. Nos. 5,854,191,
5,223,171, 5,227,446 and 5,296,470 disclose the use of graft
copolymers in cleaning applications.
[0014] Graft copolymers are produced by selectively generating
initiation sites (e.g., free radicals) for the growth of monomer
side chains from the saccharide or polysaccharide backbone (CONCISE
ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING, J. I. Kroschwitz,
ed., Wiley-Interscience, New York, p. 436 (1990)). These grafting
techniques typically use Fe(II) salts such as ferrous sulfate or
Ce(IV) salts (e.g., cerium nitrate or cerium sulfate) to create
those initiation sites on the saccharide or polysaccharide backbone
(see, e.g., U.S. Pat. No. 5,304,620). Such redox processes are not
easily controlled, are inefficient and generate unwanted
homopolymers. Also, cerium salts tend to be left in the resulting
solution as unwanted byproducts, thereby presenting a potential
negative effect on performance. Therefore, there is a need for
natural materials as polymeric building blocks that do not provide
those problems associated with graft copolymers.
SUMMARY OF THE INVENTION
[0015] The present invention discloses hybrid copolymers
compositions derived from synthetic monomers chain terminated with
a hydroxyl containing natural material. By using a hydroxyl
containing natural material as the chain transfer agent, the
molecular weight of the resultant polymer can be controlled,
especially if the chain transfer agent is low in molecular weight.
Further, no special initiation system is required, unlike graft
copolymers. As noted above, grraft copolymers typically require
special redox initiating systems containing metallic ions. In
contrast, hybrid copolymers according to the present invention use
conventional free radical initiating systems.
[0016] The materials are also structurally different than graft
copolymers disclosed in the art. Graft copolymers are defined as a
backbone of one monomer or polymer and one or more side chains
derived from another monomer(s) attached on to the backbone (Odian,
George, PRINCIPLES OF POLYMERIZATION, 2.sup.nd ed.,
Wiley-Interscience, New York, p. 424 (1981)). Graft copolymers
(such as those described in U.S. Pat. Nos. 5,854,191, 5,223,171,
5,227,446 and 5,296,470) typically have a natural polymer backbone
and short side chains derived from synthetic monomers. In contrast,
the hybrid copolymers of the present invention have long chains of
synthetic monomers that incorporate a moiety derived from natural
material at the end of the chain. From Mark, Herman F.,
ENCYCLOPEDIA OF POLYMER SCIENCE AND TECHNOLOGY, 3.sup.rd ed., Vol.
11, Wiley-Interscience, New York, p. 380 (2004), fragments of a
chain transfer agent are incorporated into polymer chains as end
groups. A transfer reaction can therefore be used to introduce
specific end groups into the polymeric material.
[0017] These hybrid copolymers are effective at minimizing a number
of different scales, including phosphate, sulfonate, carbonate and
silicate based scales. These scale-minimizing polymers are useful
in a variety of systems, including water treatment compositions,
oil field related compositions, cement compositions, cleaning
formulations and other aqueous treatment compositions. Polymers
according to the present invention have been found to be
particularly useful in minimizing scale by inhibition of scale
formation, dispersion of precipitants, and interference and
distortion of crystal structure.
[0018] It has now been found that hydroxyl containing naturally
derived materials can be used as chain transfer agents during the
production of synthetic polymers, thereby producing novel hybrid
polymeric materials. These hydroxyl containing naturally derived
materials include glycerol, citric acid and gluconic acid, as well
as monosaccharides, oligosaccharides and polysaccharides such as
sugars, maltodextrins and starches. The resulting materials have
the performance properties of synthetic polymers but use lower
cost, readily available and environmentally friendly materials
derived from renewable sources. These materials can be used in
water treatment, detergent, oil field and other dispersant
applications.
[0019] When present in aqueous treatment compositions, the hybrid
copolymer is present in an amount of about 0.001% to about 25% by
weight of the aqueous treatment composition. In another aspect, the
polymer is present in an amount of about 0.5% to about 5% by weight
of the composition.
[0020] In one aspect, the number average molecular weight of the
hybrid copolymer is between about 1000 and about 100,000. In
another aspect, the number average molecular weight of the polymer
is between about 2000 and about 25,000.
[0021] The hybrid copolymer is useful in cleaning formulations. In
such formulations the polymer is present in an amount of about
0.01% to about 10% by weight of the cleaning formulation. These
cleaning formulations can include phosphorus-based and/or carbonate
builders. The cleaning formulations include automatic dishwashing
detergent formulations. Automatic dishwashing detergent formulation
can also have ingredients such as builders, surfactants, enzymes,
solvents, hydrotropes, fillers, bleach, perfumes and/or
colorants.
[0022] The hybrid copolymer is also useful in water treatment
systems for preventing calcium carbonate and phosphate scales. In
such systems, the polymer is present in an amount of at least about
0.5 mg/L. The hybrid copolymer is also useful in water treatment
compositions or formulations for preventing calcium scales in a
water treatment system. In those water treatment compositions the
polymer is present in an amount of about 10% to about 25% by weight
of the composition.
[0023] The present invention further provides for a mineral
dispersant having the hybrid copolymer. This dispersant is able to
disperse a variety of minerals such as talc, titanium dioxide,
mica, precipitated calcium carbonate, ground calcium carbonate,
precipitated silica, silicate, iron oxide, clay, kaolin clay or
combinations thereof.
[0024] In another aspect, the hybrid copolymer can be used in a
treatment composition for aqueous systems for minimizing carbonate
and/or sulfate scale.
[0025] In another application, the hybrid copolymer can be used in
an aqueous treatment system such as a water treatment system,
oilfield system or cleaning system. When the aqueous treatment
system is an oilfield system, the sulfate scale minimized can be
barium sulfate scale.
[0026] In yet even another application, the hybrid copolymer can be
used as a binder for fiberglass. Fiberglass insulation products are
generally formed by bonding glass fibers together with a polymeric
binder. Typically, an aqueous polymer binder is sprayed onto matted
glass fibers soon after they have been formed and while they are
still hot. The polymer binder tends to accumulate at the junctions
where fibers cross each other, thereby holding the fibers together
at these points. Heat from the hot fibers vaporizes most of the
water in the binder. The fiberglass binder must be flexible so that
the final fiberglass product can be compressed for packaging and
shipping and later recover to its full vertical dimension when
installed.
[0027] Accordingly, the present invention provides a method of
preparing a hybrid copolymer wherein a monomeric solution and a
naturally derived hydroxyl containing chain transfer agent are
polymerized in the presence of an initiator solution. The initiator
solution is not a metal ion based redox system. The monomeric
solution is present in an amount of from about 25% to about 99.9%
by weight and the chain transfer agent is present in an amount of
from about 0.1% by weight to about 75% by weight, based on total
weight of the copolymer.
[0028] The present invention also provides a hybrid copolymer
having a synthetic polymer as the backbone of the copolymer, and a
naturally derived hydroxyl containing polymer as the chain
terminating portion of the copolymer.
[0029] The present invention is further directed towards a water
treatment composition for use in preventing carbonate and phosphate
scales in a water treatment system comprising the above described
hybrid copolymer, wherein the polymer is present in the composition
in an amount of about 10% to about 25% by weight of the
composition.
[0030] The present invention is further directed towards a cleaning
formulation comprising the above described hybrid copolymer,
wherein the polymer is present in an amount of about 0.01% to about
10% by weight of the cleaning formulation. The cleaning formulation
can include one or more phosphorus-based and/or carbonate builders.
The cleaning formulation can include one or more surfactants.
[0031] The cleaning formulations include automatic dishwashing
detergent formulations. These automatic dishwashing detergent
formulations can also include builders, surfactants, enzymes,
solvents, hydrotropes, fillers, bleach, perfumes and/or
colorants.
[0032] The cleaning formulations also include powdered or liquid or
unit dose detergent formulations.
[0033] The above described hybrid copolymer can be used in mineral
dispersants. Mineral dispersants include those that disperse
minerals such as talc, titanium dioxide, mica, precipitated calcium
carbonate, ground calcium carbonate, precipitated silica, silicate,
iron oxide, clay, kaolin clay or combinations thereof.
[0034] The above described hybrid copolymer can be used in aqueous
system treatment composition, wherein the aqueous system treatment
composition is able to modify calcium carbonate crystal growth in
an aqueous system. Examples of aqueous systems include water
treatment systems, oilfield systems or cleaning systems. In another
aspect, the aqueous system treatment composition is able to
minimize sulfate scale. In a further aspect the aqueous system can
be an oilfield system and the sulfate scale minimized is barium
sulfate scale.
[0035] The above described hybrid copolymer can further be used in
a binder for fiberglass. It can also be used in a superabsorbent or
rheology modifier.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The hybrid copolymers according to the present invention are
produced by using hydroxyl-containing naturally derived materials
as chain transfer agents during the production process. These
hydroxyl containing naturally derived materials range from small
molecules such as glycerol, citric acid, lactic acid, tartaric
acid, gluconic acid, glucoheptonic acid, monosaccharides and
disaccharides such as sugars, to larger molecules such as
oligosaccharides and polysaccharides (e.g., maltodextrins and
starches). Examples of these include sucrose, fructose, maltose,
glucose, and saccharose, as well as reaction products of
saccharides such as mannitol, sorbitol and so forth. The chain
transfer agents include oxidatively, hydrolytically or
enzymatically degraded monosaccharides, oligosaccharides and
polysaccharides, as well as chemically modified monosaccharides,
oligosaccharides and polysaccharides. Such chemically modified
derivatives include carboxylates, sulfonates, phosphates,
phosphonates, aldehydes, silanes, alkyl glycosides,
alkyl-hydroxyalkyls, carboxy-alkyl ethers and other
derivatives.
[0037] Use of natural materials as a chain transfer agent is an
attractive and readily available substitute for current synthetic
materials. For example, glycerol is a by-product of biodiesel
production. Glycerol is also a by-product of oils and fats used in
the manufacture of soaps and fatty acids. It can also be produced
by fermentation of sugar. Citric acid is produced industrially by
fermentation of crude sugar solutions. Lactic acid is produced
commercially by fermentation of whey, cornstarch, potatoes,
molasses, etc. Tartaric acid is one byproduct of the wine making
process.
[0038] Polysaccharides useful in the present invention can be
derived from plant, animal and microbial sources. Examples of such
polysaccharides include starch, cellulose, gums (e.g., gum arabic,
guar and xanthan), alginates, pectin and gellan. Starches include
those derived from maize and conventional hybrids of maize, such as
waxy maize and high amylose (greater than 40% amylose) maize, as
well as other starches such as potato, tapioca, wheat, rice, pea,
sago, oat, barley, rye, and amaranth, including conventional
hybrids or genetically engineered materials.
[0039] Also included are hemicellulose or plant cell wall
polysaccharides such as D-xylans. Examples of plant cell wall
polysaccharides include arabino-xylans such as corn fiber gum, a
component of corn fiber. An important feature of these
polysaccharides is the abundance of hydroxyl groups. These hydroxyl
groups provide sites for chain transfer during the polymerization
process. The higher the number of secondary and tertiary hydroxyl
groups in the molecule the more effective it will be as chain
transfer agent.
[0040] Other polysaccharides useful as chain transfer agents
include maltodextrins, which are polymers having D-glucose units
linked primarily by .alpha.-1,4 bonds and have a dextrose
equivalent (`DE`) of less than about 20. Maltodextrins are
available as a white powder or concentrated solution and are
prepared by the partial hydrolysis of starch with acid and/or
enzymes. In one aspect the chain transfer agents are glycerol,
citric acid, maltodextrins and/or low molecular weight oxidized
starches. Useful chain transfer agents according to the present
invention have molecular weights of less than about 20,000. In
another aspect, the chain transfer agents have molecular weights of
less than about 2000. In even another aspect, chain transfer agents
according to the present invention have molecular weights of less
than 1000.
[0041] Polysaccharides can be modified or derivatized by
etherification (e.g., via treatment with propylene oxide, ethylene
oxide, 2,3-epoxypropyltrimethylammonium chloride), esterification
(e.g., via reaction with acetic anhydride, octenyl succinic
anhydride (`OSA`)), acid hydrolysis, dextrinization, oxidation or
enzyme treatment (e.g., starch modified with .alpha.-amylase,
.beta.-amylase, pullanase, isoamylase or glucoamylase), or various
combinations of these treatments.
[0042] The hydroxyl-containing naturally derived chain transfer
agents can be used from about 0.1 to about 75 weight % based on
total weight of the polymer. In one aspect, the range is from about
1 to about 50 weight % of chain transfer agents based on total
weight of the polymer.
[0043] In one embodiment, the hybrid copolymers are prepared from
at least one hydrophilic acid monomer as the synthetic constituent.
Examples of such hydrophilic acid monomers include but are not
limited to acrylic acid, methacrylic acid, ethacrylic acid,
.alpha.-chloro-acrylic acid, .alpha.-cyano acrylic acid,
.beta.-methyl-acrylic acid (crotonic acid), .alpha.-phenyl acrylic
acid, .beta.-acryloxy propionic acid, sorbic acid, .alpha.-chloro
sorbic acid, angelic acid, cinnamic acid, p-chloro cinnamic acid,
.beta.-styryl acrylic acid (1-carboxy-4-phenyl butadiene-1,3),
itaconic acid, maleic acid, citraconic acid, mesaconic acid,
glutaconic acid, aconitic acid, fumaric acid, tricarboxy ethylene,
2-acryloxypropionic acid, 2-acrylamido-2-methyl propane sulfonic
acid, vinyl sulfonic acid, sodium methallyl sulfonate, sulfonated
styrene, allyloxybenzene sulfonic acid and maleic acid. Moieties
such as maleic anhydride or acrylamide that can be derivatized to
an acid containing group can be used. Combinations of
acid-containing hydrophilic monomers can also be used. In one
aspect the acid-containing hydrophilic monomer is acrylic acid,
maleic acid, methacrylic acid, 2-acrylamido-2-methyl propane
sulfonic acid or mixtures thereof.
[0044] In addition to the hydrophilic monomers described above,
hydrophobic monomers can also be used as the synthetic constituent.
These hydrophobic monomers include, for example, ethylenically
unsaturated monomers with saturated or unsaturated alkyl,
hydroxyalkyl, alkylalkoxy groups, arylalkoxy, alkarylalkoxy, aryl
and aryl-alkyl groups, alkyl sulfonate, aryl sulfonate, siloxane
and combinations thereof. Examples of hydrophobic monomers include
styrene, a-methyl styrene, methyl methacrylate, methyl acrylate,
2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl
acrylate, behenyl acrylate, 2-ethylhexyl methacrylate, octyl
methacrylate, lauryl methacrylate, stearyl methacrylate, behenyl
methacrylate, 2-ethylhexyl acrylamide, octyl acrylamide, lauryl
acrylamide, stearyl acrylamide, behenyl acrylamide, propyl
acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, 1-vinyl
naphthalene, 2-vinyl naphthalene, 3-methyl styrene, 4-propyl
styrene, t-butyl styrene, 4-cyclohexyl styrene, 4-dodecyl styrene,
2-ethyl-4-benzyl styrene, and 4-(phenyl butyl)styrene. Combinations
of hydrophobic monomers can also be used.
[0045] The polymerization process can be a solution or suspension
process. The process involves polymerization using free radical
initiators with one or more of the above hydrophilic and/or
hydrophobic monomers, and the hydroxyl containing natural products
used as chain transfer agents or chain stoppers. These chain
transfer agents can be added either at the beginning of the
reaction or during reaction as the monomer(s) is (are) added.
[0046] One advantage of this system is that it makes use of typical
free radical initiators. Unlike grafting systems, special redox
systems such as Ce(IV) salts are not required. Instead, easy-to-use
thermally activated initiators such as sodium persulfate can be
used. One skilled in the art will recognize that most initiating
systems are applicable here.
[0047] A high degree of chain transfer can lead to crosslinking and
formation of an insoluble gel. In one embodiment, this can be
avoided by ensuring that monomer and initiator are fed over the
same approximate period of time. If initiator feed lasts much
longer than monomer feed, a crosslinked gel can form, particularly
when oligopolysaccharides and polysaccharides (those having a
molecular weight greater than about 1000) are used as the chain
transfer agent.
[0048] As noted above, in some cases the reaction product forms a
hybrid gel during manufacture of these hybrid copolymers. This is
especially true if the synthetic monomer used is extremely reactive
(e.g., acrylic acid reacted at low pH (protonated form)) or if the
natural chain transfer agent has a molecular weight of greater than
about 1000. A crosslinked gel starts to form after the monomer feed
has ended and while the rest of the initiator is being fed in. This
is undesirable in most cases, since the gel product cannot be
diluted in water and therefore cannot be used in the applications
described below. The exception to this is in the manufacture of
super absorbents, rheology modifiers and gels used to treat wells
in the oil field industry.
[0049] If an undesirable gel starts to form during the process due
to a reactive monomer, it can be eliminated in a number of ways.
This includes reducing monomer reactivity by neutralizing the
monomer, illustrated in Example 10B (neutralizing the monomer
during polymerization) herein below. As noted in Example 10A,
sodium acrylate is far less reactive than acrylic acid and
therefore does not form gels that acrylic acid may form. In another
embodiment, additional chain transfer agents like thiols, sodium
hypophosphite and alcohols can also be used. Thiols and alcohols
(see, e.g., Example 10C herein below) are particularly useful in
controlling molecular weight and preventing the formation of
crosslinked gels. Finally, these gels can be eliminated by
shortening the initiator feeds so that the initiator and monomer
feeds are pumped over the same period of time (illustrated in
Example 10A).
[0050] Stabilization of aqueous systems containing scale-forming
salts and inorganic particulates involves a variety of mechanisms.
Inhibition is one conventional mechanism for eliminating the
deleterious effect of scale-forming salts. In inhibition, synthetic
polymer(s) are added that increase the solubility of the
scale-forming salt in the aqueous system.
[0051] Another stabilization mechanism is the dispersion of
precipitated salt crystals. Synthetic polymers having carboxylic
acid groups function as good dispersants for precipitated salts
such as calcium carbonates. In this mechanism, the crystals stay
dispersed rather than dissolving in the aqueous solution.
[0052] A third stabilization mechanism involves interference and
distortion of the crystal structure of the scale by the polymer,
thereby making the scale less adherent to surfaces, other forming
crystals and/or existing particulates.
[0053] Hybrid copolymers according to the present invention provide
excellent scale inhibition and deposition control under a wide
variety of conditions. For instance, the inventive polymers have
been found to minimize calcium carbonate scale formation and
deposition by means of all three mechanisms defined above.
[0054] The inventive polymers are further effective at minimizing
sulfate scale in oil field treatment applications. The hybrid
copolymers are also highly effective at dispersing particulate
matter such as minerals, clays, salts, metallic ores and metallic
oxides. Specific examples include talc, titanium dioxide, mica,
silica, silicates, carbon black, iron oxide, kaolin clay, titanium
dioxide, calcium carbonate and aluminum oxide. These particulates
can be found in a variety of applications such as coatings,
plastics, rubbers, filtration products, cosmetics, food and paper
coatings.
Water Treatment Systems
[0055] Water treatment includes prevention of calcium scales due to
precipitation of calcium salts such as calcium carbonate, calcium
sulfate and calcium phosphate. These salts are inversely soluble,
meaning that their solubility decreases as the temperature
increases. For industrial applications where higher temperatures
and higher concentrations of salts are present, this usually
translates to precipitation occurring at the heat transfer
surfaces. The precipitating salts can then deposit onto the
surface, resulting in a layer of calcium scale. The calcium scale
can lead to heat transfer loss in the system and cause overheating
of production processes. This scaling can also promote localized
corrosion.
[0056] Calcium phosphate, unlike calcium carbonate, generally is
not a naturally occurring problem. However, orthophosphates are
commonly added to industrial systems (and sometimes to municipal
water systems) as a corrosion inhibitor for ferrous metals,
typically at levels between 2.0-20.0 mg/L. Therefore, calcium
phosphate precipitation can not only result in those scaling
problems previously discussed, but can also result in severe
corrosion problems as the orthophosphate is removed from solution.
As a consequence, industrial cooling systems require periodic
maintenance wherein the system must be shut down, cleaned and the
water replaced. Lengthening the time between maintenance shutdowns
saves costs and is desirable.
[0057] It is advantageous to reuse the water in industrial water
treatment systems as much as possible. Still, water can be lost
over time due to various mechanisms such as evaporation. As a
consequence, dissolved and suspended solids become more
concentrated over time. Cycles of concentration refers to the
number of times solids in a particular volume of water are
concentrated. The quality of the water makeup determines how many
cycles of concentration can be tolerated. In cooling tower
applications where water makeup is hard (i.e., poor quality), 2 to
4 cycles would be considered normal, while 5 and above would
represent stressed conditions. Hybrid copolymers according to the
present invention perform particularly well under stressed
conditions.
[0058] One way to lengthen the time between maintenance in a water
treatment system is to use polymers that function in either
inhibiting formation of calcium salts or in modifying crystal
growth. Crystal growth modifying polymers alter the crystal
morphology from regular structures (e.g., cubic) to irregular
structures such as needlelike or florets. Because of the change in
form, crystals that are deposited are easily removed from the
surface simply by mechanical agitation resulting from water flowing
past the surface. Hybrid copolymers of the present invention are
particularly useful at inhibiting calcium phosphate based scale
formation such as calcium orthophosphate. Further, these inventive
polymers also modify crystal growth of calcium carbonate scale.
[0059] The polymers of the present invention can be added to the
aqueous systems neat, or they can be formulated into various water
treatment compositions and then added to the aqueous systems. In
certain aqueous systems where large volumes of water are
continuously treated to maintain low levels of deposited matter,
the polymers can be used at levels as low as 0.5 mg/L. The upper
limit on the amount of polymer used depends upon the particular
aqueous system treated. For example, when used to disperse
particulate matter the polymer can be used at levels ranging from
about 0.5 to about 2,000 mg/L. When used to inhibit the formation
or deposition of mineral scale the polymer can be used at levels
ranging from about 0.5 to about 100 mg/L. In another embodiment the
polymer can be used at levels from about 3 to about 20 mg/L, and in
another embodiment from about 5 to about 10 mg/L.
[0060] Once prepared, the hybrid copolymers can be incorporated
into a water treatment composition that includes the hybrid
copolymer and other water treatment chemicals. These other
chemicals can include, for example, corrosion inhibitors such as
orthophosphates, zinc compounds and tolyltriazole. As indicated
above, the amount of inventive polymer utilized in the water
treatment compositions can vary based upon the treatment level
desired for the particular aqueous system treated. Water treatment
compositions generally contain from about 10 to about 25 percent by
weight of the hybrid copolymer.
[0061] The hybrid copolymers can be used in any aqueous system
wherein stabilization of mineral salts is important, such as in
heat transfer devices, boilers, secondary oil recovery wells,
automatic dishwashers, and substrates that are washed with hard
water. The hybrid copolymer is especially effective under stressed
conditions in which other scale inhibitors fail.
[0062] The hybrid copolymers can stabilize many minerals found in
water, including, but not limited to, iron, zinc, phosphonate, and
manganese. The polymers also disperse particulate found in aqueous
systems.
[0063] Hybrid copolymers of the present invention can be used to
inhibit scales, stabilize minerals and disperse particulates in
many types of processes. Examples of such processes include sugar
mill anti-sealant; soil conditioning; treatment of water for use in
industrial processes such as mining, oilfields, pulp and paper
production, and other similar processes; waste water treatment;
ground water remediation; water purification by processes such as
reverse osmosis and desalination; air-washer systems; corrosion
inhibition; boiler water treatment; as a biodispersant; and
chemical cleaning of scale and corrosion deposits. One skilled in
the art can conceive of many other similar applications for which
the hybrid copolymer could be useful.
Cleaning Formulations
[0064] The polymers of this invention can also be used in a wide
variety of cleaning formulations containing phosphate-based
builders. For example, these formulations can be in the form of a
powder, liquid or unit doses such as tablets or capsules. Further,
these formulations can be used to clean a variety of substrates
such as clothes, dishes, and hard surfaces such as bathroom and
kitchen surfaces. The formulations can also be used to clean
surfaces in industrial and institutional cleaning applications.
[0065] In cleaning formulations, the polymer can be diluted in the
wash liquor to the end use level. The polymers are typically dosed
at 0.01 to 1000 ppm in the aqueous wash solutions. The polymers can
minimize deposition of phosphate based scale in fabric, dishwash
and hard surface cleaning applications. The polymers also help in
minimizing encrustation on fabrics. Additionally, the polymers
minimize filming and spotting on dishes. Dishes can include glass,
plastics, china, cutlery, etc. The polymers further aid in speeding
up the drying processes in these systems. While not being bound by
theory, it is believed that the hydrophobic nature of these
polymers aids in increasing the rate of drying on surfaces such as
those described above.
[0066] Optional components in the detergent formulations include,
but are not limited to, ion exchangers, alkalies, anticorrosion
materials, anti-redeposition materials, optical brighteners,
fragrances, dyes, fillers, chelating agents, enzymes, fabric
whiteners and brighteners, sudsing control agents, solvents,
hydrotropes, bleaching agents, bleach precursors, buffering agents,
soil removal agents, soil release agents, fabric softening agent
and opacifiers. These optional components may comprise up to about
90% by weight of the detergent formulation.
[0067] The polymers of this invention can be incorporated into hand
dish, autodish and hard surface cleaning formulations. The polymers
can also be incorporated into rinse aid formulations used in
autodish formulations. Autodish formulations can contain builders
such as phosphates and carbonates, bleaches and bleach activators,
and silicates. These formulations can also include other
ingredients such as enzymes, buffers, perfumes, anti-foam agents,
processing aids, and so forth. Autodish gel systems containing
hypochlorite bleach are particularly hard on polymers due to the
high pH required to maintain bleach stability. In these systems,
hydrophobes without an ester group (e.g., aromatics) are
particularly useful.
[0068] Hard surface cleaning formulations can contain other adjunct
ingredients and carriers. Examples of adjunct ingredients include,
without limitation, buffers, builders, chelants, filler salts,
dispersants, enzymes, enzyme boosters, perfumes, thickeners, clays,
solvents, surfactants and mixtures thereof.
[0069] One skilled in the art will recognize that the amount of
polymer(s) required depends upon the cleaning formulation and the
benefit they provide to the formulation. In one aspect, use levels
can be about 0.01 weight % to about 10 weight % of the cleaning
formulation. In another embodiment, use levels can be about 0.1
weight % to about 2 weight % of the cleaning formulation.
Oilfield Scale Application
[0070] Scale formation is a major problem in oilfield applications.
Subterranean oil recovery operations can involve the injection of
an aqueous solution into the oil formation to help move the oil
through the formation and to maintain the pressure in the reservoir
as fluids are being removed. The injected water, either surface
water (lake or river) or seawater (for operations offshore) can
contain soluble salts such as sulfates and carbonates. These salts
tend to be incompatible with ions already present in the
oil-containing reservoir (formation water). The formation water can
contain high concentrations of certain ions that are encountered at
much lower levels in normal surface water, such as strontium,
barium, zinc and calcium. Partially soluble inorganic salts, such
as barium sulfate and calcium carbonate, often precipitate from the
production water as conditions affecting solubility, such as
temperature and pressure, change within the producing well bores
and topsides. This is especially prevalent when incompatible waters
are encountered such as formation water, seawater, or produced
water.
[0071] Barium sulfate and strontium sulfate form very hard, very
insoluble scales that are difficult to prevent. Barium sulfate or
other inorganic supersaturated salts can precipitate onto the
formation forming scale, thereby clogging the formation and
restricting the recovery of oil from the reservoir. The insoluble
salts can also precipitate onto production tubing surfaces and
associated extraction equipment, limiting productivity, production
efficiency and compromising safety. Certain oil-containing
formation waters are known to contain high barium concentrations of
400 ppm, and higher. Since barium sulfate forms a particularly
insoluble salt, the solubility of which declines rapidly with
temperature, it is difficult to inhibit scale formation and to
prevent plugging of the oil formation and topside processes and
safety equipment.
[0072] Dissolution of sulfate scales is difficult, requiring high
pH, long contact times, heat and circulation, and can only be
performed topside. Alternatively, milling and in some cases
high-pressure water washing can be used. These are expensive,
invasive procedures and require process shutdown. The hybrid
copolymers of this invention can minimize sulfate scales,
especially downhole sulfate scales.
Dispersant for Particulates
[0073] Polymers according to the present invention can be used as a
dispersant for pigments in applications such as paper coatings,
paints and other coating applications. Examples of pigments that
can be dispersed by the inventive polymers include titanium
dioxide, kaolin clays, modified kaolin clays, calcium carbonates
and synthetic calcium carbonates, iron oxides, carbon black, talc,
mica, silica, silicates, and aluminum oxide. Typically, the more
hydrophobic the pigment the better polymers according to the
present invention perform in dispersing particulates. These
particulate matters are found in a variety of applications,
including but not limited to, coatings, plastics, rubbers,
filtration products, cosmetics, food and paper coatings.
Fiberglass Sizing
[0074] Fiberglass is usually sized with phenol-formaldehyde resins
or polyacrylic acid based resins. The former has the disadvantage
of releasing formaldehyde during end use. The polyacrylic acid
resin system has become uneconomical due to rising crude oil
prices. Hence, there is a need for renewal sizing materials in this
industry. The hybrid polymers of this invention are a good fit for
this application. They can be used by themselves or in conjunction
with the with the phenol formaldehyde or polyacrylic acid binder
system.
[0075] The binder composition is generally applied by means of a
suitable spray applicator to a fiber glass mat as it is being
formed. The spray applicator aids in distributing the binder
solution evenly throughout the formed fiberglass mat. Solids are
typically present in the aqueous solution in amounts of about 5 to
25 percent by weight of total solution. The binder can also be
applied by other means known in the art, including, but not limited
to, airless spray, air spray, padding, saturating, and roll
coating.
[0076] Residual heat from the fibers volatizes water away from the
binder. The resultant high-solids binder-coated fiberglass mat is
allowed to expand vertically due to the resiliency of the glass
fibers. The fiberglass mat is then heated to cure the binder.
Typically, curing ovens operate at a temperature of from
130.degree. C. to 325.degree. C. However, the binder composition of
the present invention can be cured at lower temperatures of from
about 110.degree. C. to about 150.degree. C. In one aspect, the
binder composition can be cured at about 120.degree. C. The
fiberglass mat is typically cured from about 5 seconds to about 15
minutes. In one aspect the fiberglass mat is cured from about 30
seconds to about 3 minutes. The cure temperature and cure time also
depend on both the temperature and level of catalyst used. The
fiberglass mat can then be compressed for shipping. An important
property of the fiberglass mat is that it returns substantially to
its full vertical height once the compression is removed. The
hybrid polymer based binder produces a flexible film that allows
the fiberglass insulation to bounce back after a roll is unwrapped
for use in walls/ceilings.
[0077] Fiberglass or other non-wovens treated with the copolymer
binder composition is useful as insulation for heat or sound in the
form of rolls or batts; as a reinforcing mat for roofing and
flooring products, ceiling tiles, flooring tiles, as a
microglass-based substrate for printed circuit boards and battery
separators; for filter stock and tape stock and for reinforcements
in both non-cementatious and cementatious masonry coatings.
[0078] The following examples are intended to exemplify the present
invention but are not intended to limit the scope of the invention
in any way. The breadth and scope of the invention are to be
limited solely by the claims appended hereto.
EXAMPLE 1
Synthesis of Hybrid Copolymer
[0079] A reactor containing 200 grams of a 50% solution of citric
acid (CA) (0.52 moles) as chain transfer agent was heated to
100.degree. C. A monomer solution containing 238 grams of a 50%
solution of sodium 2-acrylamido-2-methylpropane sulfonate (NaAMPS)
(0.52 moles) was added to the reactor over a period of 1.5 hours.
An initiator solution comprising 6.2 grams of sodium persulfate in
100 grams of deionized water was simultaneously added to the
reactor over a period of 2 hours. The mole percent of citric acid
chain transfer agent based on moles of citric acid and NaAMPS was
50%. The reaction product was held at 100.degree. C. for an
additional 2 hours. The final hybrid copolymer product was a golden
yellow solution.
EXAMPLE 2-4
Synthesis of Hybrid Copolymer
[0080] Example 1 was repeated but using lower amounts of citric
acid as the chain transfer agent. The residual amount of citric
acid left in solution was measured by liquid chromatography ("LC").
The amount of citric acid incorporated into the polymer was
calculated by the difference of citric acid added to the initial
charge and the residual amount measured by GC. The number average
molecular weight (Mn) of these polymers was measured by gel
permeation chromatography ("GPC").
TABLE-US-00001 TABLE I Varying amount of natural constituent during
polymerization Mole % CA based Wt % of citric acid on total moles
of incorporated into Example CA + NaAMPS the polymer Mn 1 50 6.4
3536 2 30 4 4867 3 20 1.2 6481 4 10 0.5 6256
The data indicates that the amount of citric acid incorporated into
the copolymer increases as the mole % of CA based on total moles of
CA+NaAMPS increases. Also, the molecular weight of the polymer
decreases when increasing amounts of CA are added to the reaction.
This lowering of molecular weight clearly demonstrates that citric
acid is incorporated into the polymer as a chain transfer
agent.
EXAMPLE 5
Synthesis of Hybrid Copolymer
[0081] A reactor containing 200 grams of a 50% solution of citric
acid (0.52 moles) and 212.4 grams of a 50% solution of NaOH (2.65
moles) was heated to 100.degree. C. A monomer solution containing
100 grams of acrylic acid (1.39 moles) was added to the reactor
over a period of 1.5 hours. An initiator solution comprising of 6.6
grams of sodium persulfate in 30 grams of deionized water was
simultaneously added to the reactor over a period of 2 hours. The
reaction product was held at 100.degree. C. for an additional
period of 2 hours. The final product was a water white
solution.
EXAMPLE 6
Synthesis of Hybrid Copolymer
[0082] A reactor containing 25 grams of a 48% solution of gluconic
acid solution and 25 grams of water was heated to 100.degree. C. A
monomer solution containing 238 grams of a 50% solution of sodium
2-acrylamido-2-methylpropane sulfonate (NaAMPS) (0.52 moles) was
added to the reactor over a period of 1.5 hours. An initiator
solution comprising of 6.2 grams of sodium persulfate in 100 grams
of deionized water was simultaneously added to the reactor over a
period of 2 hours. The reaction product was held at 100.degree. C.
for an additional period of 2 hours.
EXAMPLE 7
Synthesis of Hybrid Copolymer
[0083] A reactor containing 50 grams of a 48% solution of gluconic
acid solution was heated to 100.degree. C. A monomer solution
containing 238 grams of a 50% solution of sodium
2-acrylamido-2-methylpropane sulfonate (NaAMPS) (0.52 moles) was
added to the reactor over a period of 1.5 hours. An initiator
solution comprising of 6.2 grams of sodium persulfate in 100 grams
of deionized water was simultaneously added to the reactor over a
period of 2 hours. The reaction product was held at 100.degree. C.
for an additional period of 2 hours.
EXAMPLE 8
Synthesis of Hybrid Copolymer
[0084] A reactor containing 23.8 grams of maltodextrin as a
polysaccharide chain transfer agent (Cargill MD.TM. 01918,
spray-dried maltodextrin obtained by enzymatic conversion of common
corn starch, available from Cargill Inc., Cedar Rapids, Iowa)
dissolved in 119 grams of water was heated to 100.degree. C. A
monomer solution containing 238 grams of a 50% solution of sodium
2-acrylamido-2-methylpropane sulfonate (NaAMPS) (0.52 moles) was
added to the reactor over a period of 1.5 hours. An initiator
solution comprising of 6.2 grams of sodium persulfate in 100 grams
of deionized water was simultaneously added to the reactor over a
period of 2 hours. The reaction product was held at 100.degree. C.
for an additional 2 hours. The final product was a clear orange
solution. The solution was stable for over a year and did not
exhibit any signs of crosslinking.
EXAMPLE 9
Synthesis of Hybrid Copolymer
[0085] 100 grams of maltodextrin as a polysaccharide chain transfer
agent (Cargill MD.TM. 01918 dextrin, spray-dried maltodextrin
obtained by enzymatic conversion of common corn starch, available
from Cargill Inc., Cedar Rapids, Iowa) was initially dissolved in
135 grams of water in a reactor heated to 100.degree. C. A monomer
solution containing 108 grams of methacrylic acid was subsequently
added to the reactor over a period of 1.5 hours. An initiator
solution comprising of 6.2 grams of sodium persulfate in 28 grams
of deionized water was added to the reactor at the same time as the
monomer solution but over a period of 2 hours. The reaction product
was held at 100.degree. C. for an additional 2 hours. The polymer
was then neutralized by adding 90.7 grams of a 50% solution of
NaOH.
EXAMPLE 10A
Synthesis of Hybrid Copolymer
[0086] A reactor containing 50 grams of water was heated to
100.degree. C. A solution containing 50 grams of acrylic acid, 25
grams of maltodextrin (Cargill MD.TM. 01960 dextrin, spray-dried
maltodextrin obtained by enzymatic conversion of starch, available
from Cargill Inc., Cedar Rapids, Iowa) as a polysaccharide chain
transfer agent, and 60 grams of water was added to the reactor over
a period of 45 minutes. An initiator solution comprising of 3.3
grams of sodium persulfate in 28 grams of deionized water was
simultaneously added to the reactor over the same time frame. (It
was noticed that if the initiator feed continued after the monomer
feed, the reaction product became a crosslinked gel, which is
undesirable in most cases.) The reaction product was held at
100.degree. C. for an additional 2 hours. The polymer was then
neutralized by adding 42.5 grams of a 50% solution of NaOH.
[0087] The final product was an homogenous amber solution that is
stable for several months. In contrast, a blend of sodium
polyacrylate (ALCOSPERSE.RTM. 602N polymer, available from Alco
Chemical, Chattanooga, Tenn.) and maltodextrin (Cargill MD.TM.
01960 dextrin) separated out into phases in a period of less than
24 hours. Lack of phase separation in the final hybrid copolymer
illustrates that the acrylic acid polymer is chemically bonded to
the maltodextrin.
EXAMPLE 10B
Synthesis of Hybrid Copolymer from Monomer Reduced in
Reactivity
[0088] A reactor containing 75 grams of water and 27.8 grams of 50%
NaOH was heated to 100.degree. C. A solution containing 50 grams of
acrylic acid, 25 grams of maltodextrin (Cargill MD.TM. 01960
dextrin) as a polysaccharide chain transfer agent, and 60 grams of
water was added to the reactor over a period of 45 minutes. An
initiator solution comprising of 3.3 grams of sodium persulfate in
28 grams of deionized water was simultaneously added to the reactor
over a period of 60 minutes (extending addition of initiator feed
beyond addition of the monomer feed). The reaction product was held
at 100.degree. C. for an additional hour. The polymer was a clear
amber solution with no signs of crosslinking. This illustrates that
crosslinking can be eliminated by reducing the reactivity of the
monomer (here, by neutralizing the monomer during the reaction)
(contra Example 10A, where the neutralizer was added after the
reaction).
EXAMPLE 10C
Synthesis of Hybrid Copolymer with Addition of Crosslinking
Agent
[0089] A reactor containing 50 grams of water was heated to
100.degree. C. A solution containing 50 grams of acrylic acid, 25
grams of maltodextrin (Cargill MD.TM. 01960 dextrin) as a
polysaccharide chain transfer agent, and 60 grams of water was
added to the reactor over a period of 45 minutes. An initiator
solution comprising 3.3 grams of sodium persulfate in 28 grams of
deionized water was simultaneously added to the reactor over a
period of 60 minutes hours. After the monomer solution was added,
the reaction product started to show signs of forming a crosslinked
gel. At this point, 0.5 grams of isopropanol was added while
addition of the initiator solution was continued. The reaction
product returned to solution almost instantaneously. The reaction
product was held at 100.degree. C. for an additional hour. The
polymer was then neutralized by adding 27.8 grams of a 50% solution
of NaOH and 25 grams of water. The final product was a clear dark
yellow solution. This illustrates that crosslinking noticed in
Example 10A can be eliminated by addition of a conventional
crosslinking agent such as isopropanol.
EXAMPLE 11
Synthesis of Hybrid Copolymer Using Multiple Synthetic Monomers
[0090] A reactor containing 50 grams of water and 50 grams of
glycerol as a chain transfer agent was heated to 85.degree. C. A
solution containing 25 grams of acrylic acid and 25 grams of
styrene was added to the reactor over a period of 45 minutes. An
initiator solution comprising of 3.3 grams of sodium persulfate in
30 grams of deionized water was simultaneously added to the reactor
over a period of 60 minutes. The reaction product was held at
85.degree. C. for an additional period of 2 hours. A solution of 28
grams of 50% NaOH and 53 grams of water was added to reactor over
60 minutes. The final product was an opaque yellow solution.
EXAMPLE 12
Synthesis of Hybrid Copolymer Using Starch as Chain Transfer
Agent
[0091] A reactor containing 50 grams of water was heated to
100.degree. C. A solution containing 50 grams of acrylic acid, 25
grams of a degraded oxidized starch (low molecular weight starch
with carboxylate groups) as a polysaccharide chain transfer agent,
and 60 grams of water was added to the reactor over a period of 45
minutes. An initiator solution comprising of 6.2 grams of sodium
persulfate in 28 grams of deionized water was simultaneously added
to the reactor over a period of 45 minutes hours. (It was noticed
that if the initiator feed continued after the monomer feed, the
reaction product became a crosslinked gel, which is unusable.) The
reaction product was held at 100.degree. C. for an additional
period of 2 hours. The polymer was then neutralized by adding 42.5
grams of a 50% solution of NaOH.
EXAMPLE 13
Synthesis of Super Absorbents and Rheology Modifiers
[0092] A reactor containing 50 grams of water was heated to
100.degree. C. A solution containing 50 grams of acrylic acid, 25
grams of maltodextrin (Cargill MD.TM. 01960) as a polysaccharide
chain transfer agent, and 60 grams of water was added to the
reactor over a period of 45 minutes. An initiator solution
comprising of 3.3 grams of sodium persulfate in 28 grams of
deionized water was simultaneously added to the reactor over a
period of 60 minutes hours. A crosslinked gel is formed, which is
undesirable in most cases. However, this type of material can be
neutralized and spray dried. The spray dried product can be used as
a super absorbent or rheology modifier.
EXAMPLE 14
Dispersancy Evaluation
[0093] The polymers of Example 1 and 4 were evaluated in a clay
suspension/dispersancy test. A control without any polymer was also
tested. These materials were compared against a sodium polyacrylate
sample (NaPAA) (ALCOSPERSE.RTM. 602N, available from Alco Chemical,
Chattanooga, Tenn.). The samples were prepared by adding 2% clay
(50:50 rose clay:bandy black clay) to deionized water. The samples
were then stirred on a magnetic stir plate for 20 minutes, after
which 0.1% active polymer was added and the samples were stirred
for one minute more. The suspensions were then poured into 100 ml
graduated cylinders and allowed to rest. FIG. 1 is a photograph of
all polymers after a time period of one hour.
[0094] FIG. 1 indicates that the polymers of this invention are
excellent dispersants. Furthermore, they are comparable in
performance to synthetic polymers (NaPAA) typically used in this
type of application.
EXAMPLE 15
Anti-Redeposition
[0095] The polymers of this invention were tested for
anti-redeposition properties in a generic powdered detergent
formulation. The powdered detergent formulation was as follows:
TABLE-US-00002 Ingredient wt % Neodol 25-7 10 Sodium carbonate 46
Sodium silicate 3 Sodium sulfate 40
[0096] The test was conducted in a full scale washing machine using
3 cotton and 3 polyester/cotton swatches. The soil used was 17.5 g
rose clay, 17.5 g bandy black clay and 6.9 g oil blend (75:25
vegetable/mineral). The test was conducted for 3 cycles using 100 g
powder detergent per wash load. The polymers were dosed in at 1.0
weight % of the detergent. The wash conditions used a temperature
of 33.9.degree. C. (93.degree. F.), 150 ppm hardness and a 10
minute wash cycle.
[0097] L (luminance) a (color component) b (color component) values
before the first cycle and after the third cycle was measured as
L.sub.1, a.sub.1, b.sub.1 and L.sub.2, a.sub.2, b.sub.2,
respectively, using a spectrophotometer. .DELTA.E (color
difference) values were then calculated using the equation
below--
.DELTA.E=[(L.sub.1-L.sub.2).sup.2+(a.sub.1-a.sub.2).sup.2+(b.sub.1-b.sub-
.2).sup.2].sup.0.5
The data indicate that the polymers of this invention show
anti-redeposition/soil suspension properties even at low
concentrations in the wash liquor (a lower .DELTA.E indicates
better anti-redeposition properties).
TABLE-US-00003 TABLE 2 Effect on anti-redeposition/soil suspension
Delta Whiteness .DELTA.E Index Sample Cotton Poly/cotton Cotton
Poly/cotton Control (no polymer) 1.87 1.59 6.67 5.86 Example 3 1.29
0.82 4.48 3.06 Example 8 1.35 0.98 4.88 3.63
EXAMPLE 16
Hard Surface Cleaning Formulations
Acid Cleaner
TABLE-US-00004 [0098] Ingredient wt % Citric acid (50% solution)
12.0 Phosphoric acid 1.0 C.sub.12-C.sub.15 linear alcohol
ethoxylate with 3 moles of EO 5.0 Alkyl benzene sulfonic acid 3.0
Polymer of Example 4 1.0 Water 78.0
Alkaline Cleaner
TABLE-US-00005 [0099] Ingredient wt % Water 89.0 Sodium
tripolyphosphate 2.0 Sodium silicate 1.9 NaOH (50%) 0.1 Dipropylene
glycol monomethyl ether 5.0 Octyl polyethoxyethanol, 12-13 moles EO
1.0 Polymer of Example 5 1.0
EXAMPLE 17
Automatic Dishwash Powder Formulation
TABLE-US-00006 [0100] Ingredients wt % Sodium tripolyphosphate 25.0
Sodium carbonate 25.0 C12-15 linear alcohol ethoxylate with 7 moles
of EO 3.0 Polymer of Example 10A 4.0 Sodium sulfate 43.0
EXAMPLE 18
Water Treatment Compositions
[0101] Once prepared, the water-soluble polymers are preferably
incorporated into a water treatment composition comprising the
water-soluble polymer and other water treatment chemicals. Such
other chemicals include corrosion inhibitors such as
orthophosphates, zinc compounds and tolyl triazole. As indicated
above, the level of the inventive polymer utilized in the water
treatment compositions is determined by the treatment level desired
for the particular aqueous system treated. The water treatment
compositions generally comprise from 10 to 25 percent by weight of
the water-soluble polymer. Conventional water treatment
compositions are known to those skilled in the art and exemplary
water treatment compositions are set forth in the four formulations
below. These compositions containing the polymer of the present
invention have application in, for example, the oil field.
TABLE-US-00007 Formulation 1 Formulation 2 11.3% of Polymer of Ex.
9 11.3% Polymer of Ex. 6 47.7% Water 59.6% Water 4.2% HEDP 4.2%
HEDP 10.3% NaOH 18.4% TKPP 24.5% Sodium Molybdate 7.2% NaOH 2.0%
Tolyl triazole 2.0% Tolyl triazole pH 13.0 pH 12.64 Formulation 3
Formulation 4 22.6% of Polymer of Ex. 12 11.3% Polymer of Ex. 1
51.1% Water 59.0% Water 8.3% HEDP 4.2% HEDP 14.0% NaOH 19.3% NaOH
4.0% Tolyl triazole 2.0% Tolyl triazole pH 12.5 4.2% ZnCl.sub.2 pH
13.2
where HEDP is 1-hydroxyethylidene-1,1 diphosphonic acid and TKPP is
tri-potassium polyphosphate.
EXAMPLE 19
Cement Composition
[0102] Various quantities of the polymer produced as described in
Example 1 above (9% by weight aqueous solution of the polymer) were
added to test portions of a base cement slurry. The base cement
composition included Lone Star Class H hydraulic cement and water
in an amount of 38% by weight of dry cement. The base composition
had a density of 16.4 pounds per gallon. These compositions
containing the polymer of the present invention have application
in, for example, the oil field.
EXAMPLE 20
Automatic Non-Phosphate Dishwash Powder Formulation
TABLE-US-00008 [0103] Ingredients wt % Sodium citrate 30 Polymer of
Example 1 10 Sodium disilicate 10 Perborate monohydrate 6
Tetraacetylethylenediamine 2 Enzymes 2 Sodium sulfate 30
EXAMPLE 21
Handwash Fabric Detergent
TABLE-US-00009 [0104] Ingredients wt % Linear alkylbenzene
sulfonate 15-30 Nonionic surfactant 0-3 Na tripolyphosphate (STPP)
3-20 Na silicate 5-10 Na sulfate 20-50 Bentonite clay/calcite 0-15
Polymer of Example 4 1-10 Water Balance
EXAMPLE 22
Fabric Detergent with Softener
TABLE-US-00010 [0105] Ingredients wt % Linear alkylbenzene
sulfonate 2 Alcohol ethoxylate 4 STPP 23 Polymer of Example 11 1 Na
carbonate 5 Perborate tetrahydrate 12 Montmorillonite clay 16 Na
sulfate 20 Perfume, FWA, enzymes, water Balance
EXAMPLE 23
Bar/Paste for Laundering
TABLE-US-00011 [0106] Ingredients wt % Linear alkylbenzene
sulfonate 15-30 Na silicate 2-5 STPP 2-10 Polymer of Example 10A
2-10 Na carbonate 5-10 Calcite 0-20 Urea 0-2 Glycerol 0-2 Kaolin
0-15 Na sulfate 5-20 Perfume, FWA, enzymes, water Balance
EXAMPLE 24
Liquid Detergent Formulation
TABLE-US-00012 [0107] Ingredients wt % Linear alkyl benzene
sulfonate 10 Alkyl sulfate 4 Alcohol (C.sub.12-C.sub.15) ethoxylate
12 Fatty acid 10 Oleic acid 4 Citric acid 1 NaOH 3.4 Propanediol
1.5 Ethanol 5 Polymer of Example 11 1 Ethanol oxidase 5 u/ml Water,
perfume, minors up to 100
[0108] Although the present invention has been described and
illustrated in detail, it is to be understood that the same is by
way of illustration and example only, and is not to be taken as a
limitation. The spirit and scope of the present invention are to be
limited only by the terms of any claims presented hereafter.
* * * * *