U.S. patent application number 13/896745 was filed with the patent office on 2013-11-21 for dust suppressing aggregate.
The applicant listed for this patent is BASF SE. Invention is credited to Alexander Gershanovich, Donald C. Mente, Raymond Neff.
Application Number | 20130305797 13/896745 |
Document ID | / |
Family ID | 48485535 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130305797 |
Kind Code |
A1 |
Neff; Raymond ; et
al. |
November 21, 2013 |
DUST SUPPRESSING AGGREGATE
Abstract
A dust suppressing aggregate includes a core particle and a dust
suppressing agent. The dust suppressing agent comprises
polyurethane and is disposed about the core particle for
suppressing dusting of the core particle. A method of forming the
dust suppressing aggregate includes the steps of providing the core
particle and encapsulating the core particle with the
polyurethane.
Inventors: |
Neff; Raymond; (Northville,
MI) ; Gershanovich; Alexander; (Beverly Hills,
MI) ; Mente; Donald C.; (Grosse Ile, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BASF SE |
Ludwigshafen |
|
DE |
|
|
Family ID: |
48485535 |
Appl. No.: |
13/896745 |
Filed: |
May 17, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61648707 |
May 18, 2012 |
|
|
|
61648766 |
May 18, 2012 |
|
|
|
61648884 |
May 18, 2012 |
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Current U.S.
Class: |
71/30 ;
71/27 |
Current CPC
Class: |
B01J 13/22 20130101;
C05C 9/00 20130101; C05G 5/37 20200201; Y10T 428/2998 20150115;
B32B 27/40 20130101; C09D 175/08 20130101; C05G 3/20 20200201; B01J
13/14 20130101 |
Class at
Publication: |
71/30 ;
71/27 |
International
Class: |
C05G 3/00 20060101
C05G003/00 |
Claims
1. A dust suppressing aggregate comprising: A. a core particle; and
B. a dust suppressing agent disposed about said core particle and
comprising polyurethane for suppressing dusting of said core
particle; wherein said dust suppressing aggregate has a dust
reduction gradient of greater than 20% and a dissolution gradient
equal to or less than 30 after 1 day of aging in water at
38.degree. C.
2. A dust suppressing aggregate as set forth in claim 1 wherein
said polyurethane is present in an amount of from 0.3 to 5.5 parts
by weight based on 100 parts by weight of said core particle.
3. A dust suppressing aggregate as set forth in claim 2 having a
dust reduction gradient of greater than 60%.
4. A dust suppressing aggregate as set forth in claim 3 having a
dissolution gradient equal to or less than 15 after 1 day of aging
in water at 38.degree. C.
5. A dust suppressing aggregate as set forth in claim 1 wherein
said polyurethane comprises the reaction product of an isocyanate
component and a polyol component.
6. A dust suppressing aggregate as set forth in claim 5 wherein
said polyol component comprises a high molecular weight (HMW)
polyol having a nominal functionality of at least 2.5 and a
hydroxyl number of from 20 to 300 mg KOH/g.
7. A dust suppressing aggregate as set forth in claim 6 wherein
said HMW polyol has a viscosity at 25.degree. C. of from 100 to
2000 cps.
8. A dust suppressing aggregate as set forth in claim 5 wherein
said polyol component comprises a catalytic polyol different than
said HMW polyol and derived from an amine-based initiator.
9. A dust suppressing aggregate as set forth in claim 5 wherein
said isocyanate component comprises polymeric diphenylmethane
diisocyanate and has an NCO content of about 31.5 weight
percent.
10. A dust suppressing aggregate as set forth in claim 5 wherein
said isocyanate component and said polyol component are reacted at
an isocyanate index of from 90 to 160.
11. A dust suppressing aggregate as set forth in claim 1 wherein
said core particle comprises a fertilizer.
12. A dust suppressing aggregate as set forth in claim 1 wherein
said core particle comprises monoammonium phosphate and/or
urea.
13. A method of forming a dust suppressing aggregate including a
core particle and a dust suppressing agent comprising polyurethane
and disposed about the core particle for suppressing dusting of the
core particle, said method comprising the steps of: A. providing
the core particle; and B. encapsulating the core particle with the
polyurethane to form the dust suppressing aggregate having a dust
reduction gradient of greater than 20% and a dissolution gradient
equal to or less than 30 after 1 day of aging in water at
38.degree. C.
14. A method as set forth in claim 13 wherein the polyurethane is
present in an amount of from 0.3 to 5.5 parts by weight based on
100 parts by weight of the core particle.
15. A method as set forth in claim 14 wherein the dust suppressing
aggregate has a dust reduction gradient of greater than 60%.
16. A method as set forth in claim 15 wherein the dust suppressing
aggregate has a dissolution gradient equal to or less than 15 after
1 day of aging in water at 38.degree. C.
17. A method as set forth in claim 13 wherein the step of
encapsulating the core particle with the polyurethane is further
defined as reacting an isocyanate component and a polyol component
to form the polyurethane.
18. A method as set forth in claim 17 wherein the polyol component
comprises a high-molecular weight (HMW) polyol having a nominal
functionality of at least 2.5 and a hydroxyl number of from 20 to
300 mg KOH/g.
19. A method as set forth in claim 18 wherein the polyol component
further comprises a catalytic polyol different than the HMW polyol
and derived from an amine-based initiator.
20. A method as set forth in claim 17 wherein the isocyanate
component comprises polymeric diphenylmethane diisocyanate and has
an NCO content of about 31.5 weight percent.
21. A method as set forth in claim 17 further comprising the step
of heating at least one of the core particle, the isocyanate
component, and the polyol component to a temperature greater than
40.degree. C. prior to or simultaneous with the step of mixing the
isocyanate component and the polyol component.
22. A method as set forth in claim 17 wherein the isocyanate
component and the polyol component are reacted at an isocyanate
index of from 90 to 160.
23. A method as set forth in claim 13 wherein the core particle
comprises a fertilizer.
24. A method as set forth in claim 13 wherein the core particle
comprises monoammonium phosphate and/or urea.
25. A system for producing a dust suppressing aggregate including a
core particle and a dust suppressing agent comprising polyurethane
and disposed about said core particle for suppressing dusting of
said core particle, the polyurethane present in an amount of from
0.3 to 5.5 parts by weight based on 100 parts by weight of said
core particle and comprising the reaction product of an isocyanate
component and a polyol component, said system comprising: A. said
isocyanate component; B. said polyol component reactive with said
isocyanate component for producing the polyurethane; and C. said
core particle; wherein said dust suppressing aggregate has a dust
reduction gradient of greater than 20% and a dissolution gradient
equal to or less than 30 after 1 day of aging in water at
38.degree. C.
26. A system as set forth in claim 25 wherein said dust suppressing
aggregate has a dust reduction gradient of greater than 60%.
27. A system as set forth in claim 26 wherein said dust suppressing
aggregate has a dissolution gradient equal to or less than 15 after
1 day of aging in water at 38.degree. C.
28. A system as set forth in claim 25 wherein said polyol component
comprises a high-molecular weight (HMW) polyol having a nominal
functionality of at least 2.5 and a hydroxyl number of from 20 to
300 mg KOH/g.
29. A system as set forth in claim 25 wherein said core particle
comprises a fertilizer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S.
Provisional Patent Application Nos. 61/648,707, filed on May 18,
2012, 61/648,766, filed on May 18, 2102 and 61/648,884, filed on
May 18, 2012, which are incorporated herewith by reference in their
entirety.
[0002] This application is related to the following U.S.
Non-Provisional Patent Application assigned to the same assignee,
each of which is incorporated herein by reference in its entirety:
U.S. patent application Ser. No. ______, filed on May 17, 2013,
entitled "ENCAPSULATED PARTICLE", claiming priority to U.S.
Provisional Patent Application No. 61/648,697, having Attorney
Docket No. PF-72188/065322.00185, with Alice Hudson, Lillian
Senior, Bernard Sencherey, and Victor Granquist as inventors.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The subject invention generally relates to a dust
suppressing aggregate. More specifically, the subject invention
relates to a dust suppressing aggregate that includes a dust
suppressing agent disposed about a core particle for suppressing
dusting of the core particle.
[0005] 2. Description of the Related Art
[0006] Fertilizers comprising particulate materials tend to
generate dust during manufacturing, handling, storage, and
application. Dust is generated when the particulate materials break
into smaller particles. In particular, fertilizers comprising
ammonium phosphates, calcium phosphates, ammonium nitrates,
potassium nitrates, potassium chlorides, potassium sulfates, etc.
tend to generate substantial levels of undesirable dust.
[0007] The generation of dust during manufacturing, handling,
storage, and application of fertilizers is problematic for a number
of reasons. Typically, dust generated is ultimately wasted, i.e.,
it does not reach its intended application. The dust generated
does, however, typically enter the air and surrounding environs
which may cause health and environmental concerns. In an effort to
curtail such waste and alleviate such concerns, dust suppressants
are often applied to fertilizers to reduce the generation of
dust.
[0008] Dust suppressants are typically liquids, such as oils, but
can be solids, such as waxes. Particular examples of dust
suppressants are petroleum residue, hydrogenated mineral oil, and
wax. Dust suppressants are typically spray applied onto the
fertilizer. The spray application of the dust suppressant onto the
fertilizer typically occurs in combination with agitation in a
rotating drum or tumbler. The agitation facilitates coverage of the
dust suppressant onto the fertilizer, i.e., onto the surface of the
particulate materials.
[0009] To date, treatment of fertilizers has focused on dust
suppressants such as mineral oils and waxes. There are
disadvantages associated with such dust suppressants. Liquid dust
suppressants, such as mineral oils, may volatilize and/or migrate
into the fertilizer with time and lose their effectiveness. Solid
dust suppressants, such as waxes, can be difficult to handle,
require special application equipment, cause clumping or
agglomeration, and can inhibit the dissolution/release of the
fertilizer once applied.
[0010] Accordingly, there remains a need to develop an improved
dust suppressing agent.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0011] The invention provides dust suppressing aggregate including
a core particle and a dust suppressing agent. The dust suppressing
agent comprises polyurethane and is disposed about the core
particle for suppressing dusting of the core particle. A method of
forming the dust suppressing aggregate includes the steps of
providing the core particle and encapsulating the core particle
with the polyurethane.
[0012] The polyurethane protects the core particle and minimizes
the generation of dust by the core particle. The polyurethane is
solid, does not volatilize and/or migrate into the fertilizer with
time and lose its effectiveness as a dust suppressant. Further, the
polyol and isocyanate components from which the polyurethane is
formed promote consistent and minimal encapsulation of the core
particle by the polyurethane and form the polyurethane which is
durable and prevents clumping and agglomeration of the core
particles. Although the polyurethane serves to protect the core
particle and prevent the generation of dust, the polyurethane
allows for the rapid permeation of water and does not significantly
inhibit the dissolution/release of the core particle.
DETAILED DESCRIPTION
[0013] The instant invention provides a dust suppressing aggregate.
The dust suppressing aggregate includes a core particle and a dust
suppressing agent. The dust suppressing aggregate is typically free
of liquid dust suppressants. The core particle typically includes a
fertilizer that may include calcium, magnesium, nitrogen,
phosphate, potassium, sulfur, and combinations thereof. The
fertilizer may be selected from the group of nitrogenous
fertilizers, phosphoric fertilizers, potash fertilizers, sulfuric
fertilizers, and combinations thereof, e.g. mixed fertilizers.
Suitable fertilizers include, but are not limited to, anhydrous
ammonia, urea, ammonium nitrate, urea ammonium nitrate, potassium
nitrate, calcium ammonium nitrate, calcium phosphate, phosphoric
acid, monoammonium phosphate, ammonium polyphosphate, ammonium
phosphate sulfate, potash, ammonium nitrate, potassium nitrate,
potassium chloride, potassium sulfate, ammonium sulfate and
sulfuric acid, and combinations thereof. Typical non-limiting
examples of fertilizer include urea and monoammonium phosphate.
[0014] The core particle may also include herbicides, insecticides,
fungicides, and other components for use in agricultural
applications. However, the dust suppressing aggregate is not
limited for use in agricultural applications and the core particle
of the present invention is not limited to the components described
immediately above.
[0015] Although the shape of the core particle is not critical,
core particles having a spherical shape are preferred. Accordingly,
the core particle is typically either round or roughly spherical.
Although the core particle may be of any size, the core particle
typically has a particle size of from No. 170 to 5/16 in., more
typically from No. 35 to No. 31/2, and most typically from No. 18
to No. 5, mesh, as measured in accordance with standard sizing
techniques using the United States Sieve Series. That is, the core
particle typically has a particle size of from 0.1 to 7, more
typically from 0.5 to 5, and most typically from 1 to 4, mm. Core
particles which are round or roughly spherical and have such
particle sizes typically allow less dust suppressing agent to be
used and typically allow the dust suppressing agent to be disposed
on the core particle with increased uniformity and completeness as
compared to core particles having other particle shapes and
sizes.
[0016] The dust suppressing agent comprises polyurethane and is
disposed about the core particle for suppressing dusting of the
core particle. The polyurethane may be partially or completely
disposed about the core particle. The polyurethane comprises the
reaction product of an isocyanate component and a polyol
component.
[0017] The isocyanate component typically includes an aromatic
isocyanate. More typically, the isocyanate component includes, but
is not limited to, monomeric and polymeric methylene diphenyl
diisocyanate, monomeric and polymeric toluene diisocyanate, and
mixtures thereof. Most typically, the isocyanate component is
LUPRANATE.RTM. M20 commercially available from BASF Corporation of
Florham Park, N.J.
[0018] LUPRANATE.RTM. M20 comprises polymeric diphenylmethane
diisocyanate and has an NCO content of about 31.5 weight percent.
Polymeric methylene diphenyl diisocyanates such as LUPRANATE.RTM.
M20 offer high crosslink density and moderate viscosity.
Alternatively, monomeric methylene diphenyl diisocyanates such as
LUPRANATE.RTM. M offer low viscosity and high NCO content with low
nominal functionality. Similarly, toluene diisocyanates such as
LUPRANATE.RTM. TDI also offer low viscosity and high NCO content
with low nominal functionality.
[0019] Typically, the isocyanate component has a viscosity of from
1 to 3000, more typically from 20 to 700, and most typically from
50 to 300, centipoise at 25.degree. C. The most typical viscosity
of the isocyanate component is from 50 to 300 centipoise at
25.degree. C. to allow the isocyanate component to be sprayed onto
the core particle. Typically, the isocyanate component has a
nominal functionality from 1 to 5, more typically from 1.5 to 4,
and most typically from 2.0 to 2.7. The most typical nominal
functionality of the isocyanate component is from 2.0 to 2.7 to
allow for effective reaction of the isocyanate component with the
polyol component and for cost effectiveness. Typically, the
isocyanate component has an NCO content of from 20 to 50, more
typically from 25 to 40, and most typically from 30 to 34, % by
weight. The NCO content provides a high molecular crosslink density
that aids in the formation of the polyurethane. The NCO content
also provides more chemical bonds per unit of mass to improve cost
efficiency. The viscosity, the nominal functionality, and the NCO
content of the isocyanate component may vary outside of the ranges
above, but are typically both whole and fractional values within
those ranges.
[0020] Referring back to the polyol component, the polyol component
typically includes one or more polyols having one or more OH
functional groups, typically at least two OH functional groups. In
addition to, or in lieu of, the OH functional group(s), the polyol
component can include isocyanate-reactive moieties having one or
more NH functional groups. Typically, the polyol component includes
one or more polyols selected from the group of polyether polyols,
polyester polyols, polyether/ester polyols, and combinations
thereof. However, other polyols may also be employed.
[0021] In one embodiment, the polyol component includes a
high-molecular weight (HMW) polyol. The HMW polyol is typically a
high molecular weight, primary hydroxyl terminated polyol. The HMW
polyol is typically initiated with at least one non-amine based,
tri-functional initiator. Suitable initiators for initiating the
HMW polyol include, but are not limited to, glycerine,
trimethylolpropane, propylene glycol, dipropylene glycol,
isopropylene glocol, sorbitol, sucrose, and the like.
[0022] The HMW polyol has a number average molecular weight, of
greater than 1400 g/mol because such a number average molecular
weight, tends to improve performance properties of the
polyurethane. This number average molecular weight, tends to impart
elasticity, abrasion resistance, and controlled release properties
to the polyurethane. Typically, the HMW polyol has a number average
molecular weight, of greater than 400, more typically from 400 to
15000, and most typically from 500 to 7000, g/mol. Typically, the
HMW polyol has a viscosity of from 100 to 2000, more typically from
150 to 1800, and most typically from 200 to 1600, centipoise at
25.degree. C. Typically, the HMW polyol has a nominal functionality
of at least 1.6, more typically from 1.8 to 5, and most typically
from 1.8 to 3.2. Typically, the HMW polyol has an OH number of from
20 to 300, more typically from 23 to 275, and most typically from
25 to 250, mg KOH/g. The number average molecular weight,
viscosity, nominal functionality, and OH number of the HMW polyol
may be any value outside of the ranges above, but are typically
both whole and fractional values within those ranges. Non-limiting
examples of a typical HMW polyol include PLURACOL.RTM. 220,
PLURACOL.RTM. 2010, and PLURACOL.RTM. 4156, all commercially
available from BASF Corporation of Florham Park, N.J.
[0023] The polyol component can also include the catalytic polyol.
The catalytic polyol is different from the HMW polyol. The
catalytic polyol is referred to as a "catalytic" polyol because the
catalytic polyol can be used instead of a catalyst to facilitate
the chemical reaction of the isocyanate component with the polyol
component. Said differently, a polyol component that includes the
catalytic polyol will typically chemically react with the
isocyanate component at lower temperatures in the presence of less
catalyst (even no catalyst) than a polyol component that does not
include the catalytic polyol. The catalytic polyol is typically
derived from an amine-based initiator. The catalytic polyol may be
formed with more than one initiator. In one embodiment, the
catalytic polyol is derived from a dipropylene glycol initiator. In
another embodiment, the catalytic polyol may be co-initiated with
dipropylene glycol. Without being bound by theory, it is believed
that amine content of the catalytic polyol facilitates the reaction
of the isocyanate component with the polyol component.
[0024] The catalytic polyol may also include alkylene oxide
substituents. Examples of suitable alkylene oxides substituents
include ethylene oxide, propylene oxide, butylene oxide, amylene
oxide, mixtures thereof, alkylene oxide-tetrahydrofuran mixtures,
epihalohydrins, and aralkylene styrene.
[0025] One embodiment of the catalytic polyol that is formed from
an amine-based initiator typically has a viscosity of from 500 to
75,000, more typically from 32,000 to 72,000, and most typically
from 42,000 to 62,000 centipoise at 25.degree. C.; a nominal
functionality typically greater than 2.5, more typically of from
2.75 to 10, and most typically from 3 to 4; an OH number of from
200 to 950, more typically from 250 to 850, and most typically from
750 to 800, mg KOH/g; and a number average molecular weight of less
than 1400, more typically from 100 to 1120, and most typically from
192 to 392, g/mol. The viscosity, nominal functionality, OH number,
and number average molecular weight of the catalytic polyol of this
embodiment may vary outside of the ranges above, but are typically
both whole and fractional values within those ranges. One example
of a suitable catalytic polyol of this embodiment is commercially
available from BASF Corporation of Florham Park, N.J. under the
trade name of QUADROL.RTM..
[0026] Another embodiment of the catalytic polyol is formed from an
aromatic amine-based initiator. The aromatic amine-based initiator
is of the formula:
##STR00001##
wherein R.sub.1 includes one of an alkyl group, an amine group, and
a hydrogen and each of R.sub.2-R.sub.6 independently include one of
an amine group and a hydrogen, so long as at least one of
R.sub.1-R.sub.6 is an amine group. Therefore, it is to be
understood that R.sub.1 can be any one of an alkyl group, an amine
group, or a hydrogen, or any compound including combinations
thereof. It is also to be understood that R.sub.2-R.sub.6 do not
have to be identical and each can include an amine group or a
hydrogen. It is also to be understood that the terminology "an
amine group" refers to R--N--H and NH.sub.2 throughout.
[0027] The aromatic amine-based initiator may include, but is not
limited to, a toluene diamine. The toluene diamine typically
includes, but is not limited to, the following structures:
##STR00002##
wherein the toluene diamine includes, but is not limited to,
2,3-toluenediamine, 2,4-toluenediamine, 2,5-toluenediamine,
2,6-toluenediamine, 3,4-toluenediamine, 3,5-toluenediamine, and
mixtures thereof.
[0028] The aromatic amine-based initiator tends to yield a
catalytic polyol that is miscible with the isocyanate component,
e.g. completely miscible. The miscibility of the isocyanate
component and the catalytic polyol that is derived from an aromatic
amine-based initiator tends to result from two primary effects.
First, the miscibility is affected by London Forces that create
momentarily induced dipoles between similar aromatic moieties of
the catalytic polyol and the isocyanate component. The momentarily
induced dipoles allow the catalytic polyol and the isocyanate
component to mix effectively. Secondly, the miscibility is affected
by the planar geometry of the aromatic moieties of the catalytic
polyol and the isocyanate component that allow for complementary
stacking of the catalytic polyol and isocyanate component. As such,
the isocyanate component and the polyol component mix
effectively.
[0029] The embodiment of the catalytic polyol formed from an
aromatic amine-based initiator typically has a viscosity of from
400 to 100,000, more typically from 450 to 10,000, and most
typically from 500 to 2500, centipoise at 25.degree. C.; a nominal
functionality typically greater than 2.5, more typically from 2.75
to 10, and most typically from 3 to 4; an OH number of from 200 to
950, more typically from 250 to 850, and most typically from 750 to
800, mg KOH/g; and a number average molecular weight of less than
1400, more typically from 100 to 1120, and most typically from 639
to 839, g/mol. The viscosity, nominal functionality, OH number, and
number average molecular weight of the catalytic polyol of this
embodiment may vary outside of the ranges above, but are typically
both whole and fractional values within those ranges. Examples of
suitable catalytic polyols of this embodiment are commercially
available from BASF Corporation of Florham Park, N.J. under the
trade names of PLURACOL.RTM. 1168 and PLURACOL.RTM. 1578.
[0030] If present, the catalytic polyol is typically present in the
polyol component in an amount of from 1 to 95, more typically in an
amount from to 65, and most typically in an amount from 15 to 35,
parts by weight based on 100 parts by weight of the polyol
component. The amount of the catalytic polyol may vary outside of
the ranges above, but is typically both whole and fractional values
within those ranges.
[0031] If the HMW and the catalytic polyol are both present in the
polyol component, the catalytic polyol is typically present in the
polyol component in an amount which is less than the amount of the
HMW polyol. A weight ratio of the HMW polyol to the catalytic
polyol in the polyol component is typically of from 1:1 to 15:1,
more typically from 2:1 to 12:1, and most typically from 2.5:1 to
10:1. The weight ratio of the HMW polyol to the catalytic polyol
may vary outside of the ranges above, but is typically both whole
and fractional values within those ranges.
[0032] The polyurethane can be formed in the presence of a silicone
surfactant. The silicone surfactant is typically a
polyorganosiloxane. A non-limiting example of a typical
polyorganosiloxane is an alkyl pendent organosilicone molecule
comprising a polysiloxane backbone and polyether side chains. The
alkyl pendent organosilicone molecule of this example can be comb
structured or dendrimer structured.
[0033] The silicone surfactant typically improves the wetting of
the polyol component and the isocyanate component on the core
particle and, accordingly, may also be described as a wetting
agent. The silicone surfactant also typically improves the adhesion
of the polyurethane to the core particle. In addition, the silicone
surfactant reduces clumping and agglomeration of the dust
suppressing aggregate during and after the encapsulation process.
As such, the silicone surfactant promotes more complete
encapsulation of the core particle by the polyurethane, promotes
consistent thickness of the polyurethane, allows for formation of
the polyurethane having minimal but consistent thickness, reduces
the amount of the polyurethane that is required to coat the core
particle thereby decreasing the amount of the isocyanate component
and the polyol component collectively required to encapsulate the
core particles with a consistently thick coating of the
polyurethane, increases a yield of dust suppressing aggregates
encapsulated with a consistent coating of the polyurethane, and
minimizes pits and depressions in the polyurethane. Typically, the
silicone surfactant is a liquid and has a viscosity of from 100 to
1500, more typically from 200 to 1000, and most typically from 650
to 850, cSt at 25.degree. C. The viscosity of the silicone
surfactant may vary outside of the ranges above, but is typically
both whole and fractional values within those ranges.
[0034] Specific examples of suitable silicone surfactants include,
but are not limited to, TEGOSTAB.RTM. BF 2370, commercially
available from Goldschmidt AG of Essen, Del., DABCO.RTM. DC5043
commercially available from Air Products and Chemicals, Inc. of
Allentown, Pa., and NIAX.RTM. Silicone L-5340 and L-620, both
commercially available from Momentive Performance Materials of
Albany, N.Y. A particularly suitable silicone surfactant is
NIAX.RTM. Silicone L-620, a polyalkyleneoxidemethylsiloxane
copolymer. The silicone surfactant may be present in the polyol
component in an amount of from 0.01 to 10, typically from 0.05 to
5, and more typically from 0.5 to 1.5, parts by weight based on 100
parts by weight of all components used to form the polyurethane.
The parts by weight silicone surfactant may vary outside of the
ranges above, but is typically both whole and fractional values
within those ranges.
[0035] The polyurethane may optionally include one or more
additives. The additives are typically included in polyol
component, but can be included in the isocyanate component or added
separately. Suitable additives for purposes of the present
invention include, but are not limited to, chain-extenders,
cross-linkers, chain-terminators, processing additives, adhesion
promoters, anti-oxidants, defoamers, flame retardants, catalysts,
anti-foaming agents, water scavengers, molecular sieves, fumed
silicas, surfactants, ultraviolet light stabilizers, fillers,
thixotropic agents, silicones, colorants, pigments, inert diluents,
and combinations thereof. For example, a pigment can be included in
the polyurethane. If included, the additives can be included in the
polyurethane in various amounts.
[0036] The dust suppressing agent comprising polyurethane is
typically present in the dust suppressing aggregate in an amount of
from 0.3 to 5.5, more typically from 0.5 to 3.0, and most typically
from 0.7 to 2.0, parts by weight based on 100 parts by weight of
the core particle. The amount of dust suppressing agent comprising
polyurethane present in the dust suppressing aggregate may vary
outside of the ranges above, but is typically both whole and
fractional values within those ranges.
[0037] The dust suppressing aggregate, including the core particle
and the polyurethane thereon, is typically either round or roughly
spherical. The dust suppressing aggregates have a size distribution
reported as D[4,3], d(0.1), d(0.5), and/or d(0.9), as well defined
and appreciated in the art. In several embodiments, the dust
suppressing aggregates have a size distribution D[4,3] of from 0.5
to 5 mm, of from 1 to 4 mm, or of from 1 to 3 mm, with an overall
particle size range of from 0.1 to mm. In other embodiments, the
dust suppressing aggregates have a size distribution d(0.1) of from
0.2 to 2 mm, of from 0.4 to 1.7 mm, or of from 0.5 to 1.5 mm, with
an overall particle size range of from 0.1 to 10 mm. In further
embodiments, the dust suppressing aggregates have a size
distribution d(0.5) of from 0.5 to 5 mm, of from 1 to 4 mm, or of
from 1 to 3 mm, with an overall particle size range of from 0.1 to
mm. In still other embodiments, the dust suppressing aggregates
have a size distribution d(0.9) of from 0.7 to 7 mm, of from 0.8 to
5 mm, or of from 1 to 4 mm, with an overall particle size range of
from 0.1 to 10 mm. The D[4,3], d(0.1), d(0.5), and d(0.9) size
distributions of the dust suppressing aggregates may vary outside
of the ranges above, but are typically both whole and fractional
values within 0.5 to 5 mm, 0.2 to 2 mm, 0.5 to 5 mm, and 0.7 to 7
mm, respectively.
[0038] The dust suppressing performance of the dust suppressing
agent can be determined. To test the dust suppressing performance
of the dust suppressing agent, a dust value (ppm) of the dust
suppressing aggregate is determined. Dust value is measured by
placing a 50 g sample of the dust suppressing aggregate in a 125 mL
wide mouth glass jar. The jar is placed in a Burrell Model 75
wrist-action shaker, and shaken for 20 minutes at the maximum
intensity setting (10). After shaking, the sample is weighed and
then processed in a dust removal apparatus. The dust removal
apparatus consists of a 2.5 in. diameter plastic cup, a cup holder,
an air flow meter, and a vacuum cleaner. The base of the cup is
removed and replaced with a 200 mesh screen. Each sample is placed
into the cup, the cup is placed into the holder, and then air is
drawn through the sample for two minutes at a rate of 9 standard
cubic feet per minute using the vacuum cleaner. The sample is then
re-weighed. The amount of dust is calculated from the weight
difference before and after dust removal. Results are reported as
an average of two replicates.
[0039] Typically, the dust suppressing aggregate has a dust value
of less than 3000, more typically less than 2000, still more
typically less than 1000, even more typically less than 500, and
most typically less than 250, ppm.
[0040] In one embodiment, the dust suppressing aggregate comprises
the dust suppressing agent in an amount no greater than 1 part by
weight based on 100 parts by weight of the dust suppressing
aggregate and has an initial dust value of less than 1000, more
typically less than 750, and most typically less than 500, ppm.
[0041] In another embodiment, the dust suppressing aggregate
comprises the dust suppressing agent in an amount no greater than 2
parts by weight based on 100 parts by weight of the dust
suppressing aggregate and has an initial dust value of less than
500, more typically less than 200, and most typically less than
150, ppm.
[0042] A dust reduction gradient (%) can be determined with the
dust value. The dust reduction gradient is calculated with the
following formula:
[(Dust Value A-Dust Value B)/Dust Value A].times.100
[0043] Dust Value A is the dust value of the uncoated core
particle
[0044] Dust Value B is the dust value of the dust suppressing
aggregate comprising an identical core particle.
[0045] Said differently, once the dust value for the uncoated core
particle and dust suppressing aggregate are determined under
certain conditions, the dust reduction gradient (%) is the percent
difference in the amount of dust generated by the uncoated core
particle and the coated core particle, i.e., the dust suppressing
aggregate. Typically, the larger the dust reduction gradient, the
better. In one embodiment, the dust suppressing aggregate comprises
the dust suppressing agent in an amount no greater than 1 part by
weight based on 100 parts by weight of the dust suppressing
aggregate and has an initial dust reduction gradient of greater
than 10, more typically greater than 50, and most typically greater
than 80, %.
[0046] In another embodiment, the dust suppressing aggregate
comprises the dust suppressing agent in an amount no greater than 2
parts by weight based on 100 parts by weight of the dust
suppressing aggregate and has an initial dust reduction gradient of
greater than 20, more typically greater than 60, and most typically
greater than 90, %.
[0047] The polyurethane of the dust suppressing aggregate has
minimal impact dissolution of the core particle. That is, the dust
suppressing agent comprising polyurethane minimally impacts the
rate at which the core particle dissolves. Dissolution is the
amount of core particle that dissolves in water under certain
conditions and is typically measured in weight percent, as is
described in greater detail immediately below.
[0048] Dissolution is measured by placing 50 g of the dust
suppressing aggregate in a 250 mL plastic bottle. Then 230 g of
deionized water is added to the bottle. The plastic bottle is
allowed to stand undisturbed for 8 hours at room temperature
(23.degree. C.). A liquid sample is then drawn, and its refractive
index is measured using a refractometer. An amount (in grams) of
the core particle dissolved in each solution sample is calculated
using the refractive index and a temperature-corrected standard
curve. The amount of the core particle dissolved is utilized to
calculate dissolution (%) with the following formula:
Dissolution (%)=X/(50-(Weight Percent Dust Suppressing Agent
Applied/2))
X=the amount of core particle (grams) dissolved in the solution
sample.
Weight Percent Dust Suppressing Agent Applied=100%.times.Dust
Suppressing Agent Applied/Weight of Dust Suppressing Aggregate
[0049] A dissolution gradient can be determined with the
dissolution. The dissolution gradient is simply the difference in
the dissolution (%) of the uncoated core particle and the
dissolution of the core particle of the dust suppressing aggregate.
Said differently, once the dissolution for the uncoated core
particle and the dust suppressing aggregate are determined under
certain conditions, the dissolution gradient is absolute value of
the dissolution of the uncoated core particle minus the dissolution
of the dust suppressing aggregate. Typically, the smaller the
dissolution gradient, the better. Although the dust suppressing
agent should inhibit dusting of the core particle, it is typically
desired that the dust suppressing agent minimally impact the
dissolution of the core particle. Typically, the dust suppressing
aggregate has a dissolution gradient equal to or less than 30, more
typically less than 15, still more typically less than 10, and most
typically less than 5 after 1 day of aging in water at 23.degree.
C.
[0050] In addition to the dust suppressing aggregate, the subject
invention relates to a system for forming the dust suppressing
aggregate and a method of forming the dust suppressing aggregate.
The system for forming the dust suppressing aggregate includes the
isocyanate component, the polyol component, and the core
particle.
[0051] The method includes the steps of providing the core particle
and encapsulating the core particle with the polyurethane. The step
of encapsulating the core particle with the polyurethane can be
further defined as reacting the isocyanate component and the polyol
component to form the polyurethane. Typically, the isocyanate
component and the polyol component are mixed, i.e. combined, and
chemically react to form the polyurethane. Typically, the
isocyanate component and the polyol component are reacted at an
isocyanate index of from 90 to 160, more typically from 110 to 140,
and most typically from 125 to 135. As well known in the art,
isocyanate index is a ratio of an actual molar amount of
isocyanate(s) reacted with the polyol(s) to a stoiciometric molar
amount of isocyanate(s) needed to react with an equivalent molar
amount of the polyol(s). The step of reacting the isocyanate
component and the polyol component can be conducted prior to the
step of encapsulating the core particle with the polyurethane.
Alternatively, the step of reacting the isocyanate component and
the polyol component can be conducted simultaneous with the step of
encapsulating the core particle with the polyurethane.
[0052] The isocyanate component and the polyol component may be
combined using one or more techniques including, but not limited
to, pouring, pan coating, fluidized-bed coating, co-extrusion,
mixing, spraying and spinning disk encapsulation. Most typically,
the isocyanate component and the polyol component are mixed by
spraying into or above the reaction vessel such as a barrel, a
drum, mixer, or the like. The polyol component and the isocyanate
component can be mixed and sprayed into or above the reaction
vessel with a single spray gun or multiple spray guns. In one
embodiment, the isocyanate component and the polyol component are
impingement mixed in a spray nozzle. The polyol component and the
isocyanate component can also be sequentially sprayed into or above
the reaction vessel with a single spray gun and mixed in the
reaction vessel. Alternatively, the isocyanate component and the
polyol component can be simultaneously or sequentially sprayed into
or above the reaction vessel with different spay guns.
[0053] As just one non-limiting example, the isocyanate component
and the polyol component can be sprayed onto the core particle in
the following sequence: (1) a portion of the isocyanate component
is sprayed onto the core particle; (2) a portion of the of the
polyol component is sprayed onto the core particle; (3) a remaining
portion of the isocyanate component is sprayed onto the core
particle; and, (4) a remaining portion of the polyol component is
sprayed onto the core particle. As another non-limiting example,
the isocyanate component and the polyol component can be sprayed
onto the core particle in the following sequence: (1) a portion of
the isocyanate component is sprayed onto the core particle; (2) a
portion of the of the polyol component is sprayed onto the core
particle and a remaining portion of the isocyanate component is
sprayed onto the core particle simultaneously; and, (3) a remaining
portion of the polyol component is sprayed onto the core
particle.
[0054] The method optionally includes the step(s) of heating the
isocyanate component, the polyol component, and/or the core
particles prior to, or simultaneous with, the step of mixing the
isocyanate component and the polyol component. The isocyanate
component, the polyol component, the silicone surfactant, and/or
the core particles may be individually heated or heated in
combination with one or more of each other. The isocyanate
component, the polyol component, and the core particle are
typically heated prior to or simultaneous with the step of
encapsulating the core particle. Typically, the isocyanate
component, the polyol component, and the core particle are heated
to a temperature of greater than 40, more typically to a
temperature of from 45 to 90, and most typically from 50 to 80,
.degree. C.
[0055] The step of encapsulation can occur once or can be repeated.
If repeated the step does not have to be the same each individual
time. The core particle may be encapsulated one time with the
polyurethane or multiple times with the polyurethane. It is
contemplated that the core particle can be encapsulated with the
polyurethane and one or more additional dust suppressing agents.
The core particle may be partially or totally encapsulated.
[0056] The following examples illustrate the nature of the
invention and are not to be construed as limiting of the
invention.
EXAMPLES
[0057] Example Dust Suppressing Aggregates (Examples) A-D are
described herein. Examples A-D include a core particle and a dust
suppressing agent comprising polyurethane disposed about the core
particle. Examples A-D are formed in accordance with the present
invention.
[0058] To form Examples A-D, a dust suppressing agent comprising
polyurethane is disposed about a core particle. The compositions
used to form Examples A-D, in grams, are set forth below in Table
1. Polyol A is pre-heated to a temperature of 150.degree. F. in a
first vessel. Isocyanate is pre-heated to a temperature of
150.degree. F. in a second vessel. Core Particle A is pre-heated to
a temperature of 150.degree. F. in a third vessel. Once pre-heated,
the Core Particle A is added to a reaction vessel having a roller
speed of 26 rpm. Once the Core Particle A is added, the Isocyanate
is added to the reaction vessel and agitated for 2 minutes with the
Core Particle A. Next, the Polyol A is added to the reaction vessel
and agitated with the Isocyanate and the Core Particle A for 10
more minutes. During agitation, the Polyol A and the Isocyanate
react to form the dust suppressing agent comprising polyurethane
and disposed about the Core Particle A.
TABLE-US-00001 TABLE 1 Comparative Core Particle Example A Example
B Example C Example D Polyol A -- 24.5 27.0 16.3 18 Isocyanate --
5.5 3.0 3.7 2 Core Particle A 2000 2000 2000 2000 2000 Total 2000
2030 2030 2020 2020 Isocyanate -- 170 85 170 85 Index Weight
Percent 0 1.5 1.5 1 1 Dust Suppressing Agent Applied (%) Polyol A
is PLURACOL .RTM. 4156, a high molecular weight polyol commercially
available from BASF Corporation of Florham Park, NJ. Isocyanate is
LUPRANATE .RTM. M20, a polymeric methylene diphenyl diisocyanate
commercially available from BASF Corporation of Florham Park, NJ.
Core Particle A is MicroEssentials MES-z, a fertilizer commercially
available from Mosaic of Plymouth, MN.
[0059] The dust suppressing agent comprising polyurethane of
Examples A-D encapsulates the Core Particle A and prevents dust
formation upon mechanical abrasion. Further, the dust suppressing
agent comprising polyurethane does not significantly inhibit or
prevent the dissolution of the Core Particle A.
[0060] Example Dust Suppressing Aggregates (Examples) E-U are also
described herein. Examples E-U include a core particle and a dust
suppressing agent comprising polyurethane disposed about the core
particle. Examples E-U are formed in accordance with the present
invention.
[0061] To form Examples E-U, a dust suppressing agent comprising
polyurethane is disposed about a Core Particle. The compositions
used to form Examples E-U, in grams, are set forth below in Tables
2 and 3. One or more polyols and additives are mixed to form a
polyol component and pre-heated to a temperature of 150.degree. F.
in a first vessel. Isocyanate is pre-heated to a temperature of
150.degree. F. in a second vessel. Core Particle A or B (depending
on the Example) is pre-heated to a temperature of 150.degree. F. in
a third vessel. Once pre-heated, the Core Particle A or B is added
to a reaction vessel having a roller speed of 26 rpm. Once the Core
Particle A or B is added, the Isocyanate is added to the reaction
vessel and agitated for 2 minutes with the Core Particle A or B.
Next, the polyol component is added to the reaction vessel and
agitated with the Isocyanate and the Core Particle A or B for 10
more minutes. During agitation, the polyol component and the
Isocyanate react to form the dust suppressing agent comprising
polyurethane and disposed about the Core Particle.
TABLE-US-00002 TABLE 2 Ex. E Ex. F Ex. G Ex. H Ex. I Ex. J Ex. K
Ex. L Ex. M Polyol A -- -- -- -- -- -- -- 16.91 32.81 Polyol B .38
.76 .76 11.37 18.42 11.51 5.75 5.47 10.94 Polyol C 1.14 2.27 2.27
34.11 -- 34.53 17.26 -- -- Polyol D -- -- -- -- 55.27 -- -- -- --
Additive A .01 .02 .02 .27 .44 -- -- -- -- Additive B .02 .03 .03
.45 .74 -- -- -- -- Additive C .02 .03 .03 .45 .74 0.46 .23 .22 .44
Isocyanate 0.44 .89 .89 13.34 44.39 13.5 6.75 7.91 15.81 Core 200
200 200 3000 -- 3000 3000 3000 3000 Particle A Core -- -- -- --
3000 -- -- -- -- Particle B Total 202 204 204 3060 3120 3060 3030
3031 3060 Isocyanate 130 130 130 130 130 130 130 130 130 Index
Weight 1 2 2 2 4 2 1 1 2 Percent Dust Suppressing Agent Applied
(%)
TABLE-US-00003 TABLE 3 Ex. N Ex. O Ex. P Ex. Q Ex. R Ex. S Ex. T
Ex. U Polyol A 2.19 3.38 3.41 -- -- -- -- -- Polyol B .73 -- -- --
-- -- -- -- Polyol C -- -- -- -- -- -- -- -- Polyol E -- -- -- 3.68
-- -- -- -- Polyol F -- -- -- -- 1.79 -- -- -- Polyol G -- -- -- --
-- 3.54 -- -- Polyol H -- -- -- -- -- -- 1.34 1.11 Additive C .03
.03 -- -- -- -- -- -- Isocyanate 1.05 0.58 0.59 0.32 2.21 0.46 2.66
2.89 Core Particle 400 400 400 400 400 400 400 400 A Total 404 404
404 404 404 404 404 404 Isocyanate 130 130 130 130 130 130 130 130
Index Weight 1 1 1 1 1 1 1 1 Percent Dust Suppressing Agent Applied
(%) Polyol B is PLURACOL .RTM. 1168, an aromatic amine-initiated
polyol commercially available from BASF Corporation of Florham
Park, NJ. Polyol C is PLURACOL .RTM. 220, a high molecular weight
polyol commercially available from BASF Corporation of Florham
Park, NJ. Polyol D is castor oil. Polyol E is PLURACOL .RTM. 4650,
an aromatic amine-initiated polyol commercially available from BASF
Corporation of Florham Park, NJ. Polyol F is PLURACOL .RTM. GP430,
an aromatic amine-initiated polyol commercially available from BASF
Corporation of Florham Park, NJ. Polyol G is PLURACOL .RTM. 593, an
aromatic amine-initiated polyol commercially available from BASF
Corporation of Florham Park, NJ. Polyol H is dipropylene glycol.
Additive A is ANTIFOAM A, an anti-foaming additive commercially
available from Dow Corning Corporation of Midland, MI. Additive B
is MOLSIV 3A, molecular sieves commercially available from UOP of
Des Plaines, IL. Additive C is NIAX .RTM. L-620, a silicone
surfactant commercially available from Momentive Performance
Materials of Albany, NY. Isocyanate is LUPRANATE .RTM. M20, a
polymeric methylene diphenyl diisocyanate commercially available
from BASF Corporation of Florham Park, NJ. Core Particle B is urea
granules.
[0062] The dust suppressing agent comprising polyurethane of
Examples E-U encapsulates the Core Particle A and prevents dust
formation upon mechanical abrasion. Further, the dust suppressing
agent comprising polyurethane does not significantly inhibit or
prevent the dissolution of the Core Particle B.
[0063] Example Dust Suppressing Aggregates (Examples) V-X and
Comparative Example A are described herein. Examples V-X include a
core particle and a dust suppressing agent comprising polyurethane
disposed about the core particle. Examples V-X are formed in
accordance with the present invention. Comparative Example A is not
formed in accordance with the present invention and is included for
comparative purposes.
[0064] To form Examples V-X, a dust suppressing agent comprising
polyurethane is disposed about a Core Particle. The compositions
used to form Examples V-X, in grams, are set forth below in Table
4. One or more polyols and additives are mixed to form a polyol
component and pre-heated to a temperature of 150.degree. F. in a
first vessel. Isocyanate is pre-heated to a temperature of
150.degree. F. in a second vessel. Core Particle B is pre-heated to
a temperature of 150.degree. F. in a third vessel. Once pre-heated,
the Core Particle B is added to a reaction vessel having a roller
speed of 26 rpm. Once the Core Particle B is added, the Isocyanate
is added to the reaction vessel and agitated for 2 minutes with the
Core Particle B. Next, the polyol component is added to the
reaction vessel and agitated with the Isocyanate and the Core
Particle B for 10 more minutes. During agitation, the polyol
component and the Isocyanate react to form the dust suppressing
agent comprising polyurethane and disposed about the Core Particle
B.
TABLE-US-00004 TABLE 4 Comparative Example Example Example A V W
Example X Polyol A -- 24.5 48.9 7.8 Polyol I -- -- -- 7.8
Isocyanate -- 5.5 11.5 14.5 Core Particle B 3000 3000 3000 3000
Weight Percent 0 1 2 1 Dust Suppressing Agent Applied (%) Dust
Value 877 210 150 500 (ppm) Dust Reduction NA 76.1 82.9 43.0
Gradient (%) Dissolution (%) 60.4 70.7 57.8 66.5 (8 hours at
23.degree. C.) Dissolution NA 10.3 2.6 6.1 Gradient *Polyol B is
PLURACOL .RTM. 1168, an aromatic amine-initiated polyol
commercially available from BASF Corporation of Florham Park, NJ.
Core Particle B is SGN 250 (granular urea), a fertilizer
commercially available from CF Industries of Deerfield, IL. The
urea granules are sifted with US #5 and US #16 sieves to control
particle size prior to use.
[0065] Dust value (ppm) is measured by placing 50 g sample of each
Example dust suppressing aggregate in a 125 mL wide mouth glass
jar. The jar is placed in a Burrell Model 75 wrist-action shaker,
and shaken for 20 minutes at the maximum intensity setting (10).
After shaking, the sample is weighed and then processed in a dust
removal apparatus. The dust removal apparatus consists of a 2.5 in.
diameter plastic cup, a cup holder, an air flow meter, and a vacuum
cleaner. The base of the cup is removed and replaced with a 200
mesh screen. Each sample is placed into the cup, the cup is placed
into the holder, and then air is drawn through the sample for two
minutes at a rate of 9 standard cubic feet per minute using the
vacuum cleaner. The sample is then re-weighed. The amount of dust
is calculated from the weight difference before and after dust
removal. Results are reported as an average of two replicates.
[0066] A dust reduction gradient (%) is determined with the dust
value. The dust reduction gradient is calculated with the following
formula: [0067] [(Dust Value A--Dust Value B)/Dust Value
A].times.100
[0068] Dust Value A is the dust value of the uncoated core
particle
[0069] Dust Value B is the dust value of the dust suppressing
aggregate comprising an identical core particle.
[0070] Dissolution (%) is measured by placing 50 g sample of each
Example dust suppressing aggregate in a 250 mL plastic bottle. Then
230 g of deionized water is added to the bottle. The plastic bottle
is allowed to stand undisturbed for 8 hours at room temperature
(23.degree. C.). A liquid sample is then drawn, and its refractive
index is measured using a refractometer. An amount (in grams) of
the core particle dissolved in each solution sample is calculated
using the refractive index and a temperature-corrected standard
curve. The amount of the core particle dissolved is utilized to
calculate dissolution (%) (e.g. percent urea dissolved) with the
following formula:
Dissolution (%)=X/(50-(Weight Percent Dust Suppressing Agent
Applied/2))
X=the amount of core particle (grams) dissolved in the solution
sample.
% Coating=100%.times.Dust Suppressing Agent Applied/Weight of Dust
Suppressing Aggregate
[0071] A dissolution gradient is determined with the dissolution
(%). The dissolution gradient is simply the difference in the
dissolution (%) of the uncoated core particle and the dissolution
of the core particle of the dust suppressing aggregate. Said
differently, once the dissolution for the uncoated core particle
and the dust suppressing aggregate are determined under certain
conditions, the dissolution gradient is absolute value of the
dissolution (%) of the uncoated core particle minus the dissolution
of the dust suppressing aggregate. Typically, the smaller the
dissolution gradient, the better. Although the dust suppressing
agent should inhibit dusting of the core particle, it is typically
desired that the dust suppressing agent minimally impact the
dissolution of the core particle.
[0072] Referring now to Table 4, the dust values of Examples V-X
are substantially lower than the dust values of the Comparative
Example A (uncoated Core Particle B). More specifically, the dust
suppressing agent comprising polyurethane of Examples V-X
encapsulates the Core Particle B and prevents dust formation upon
mechanical abrasion, as indicated by the low dust values and the
high dust reduction gradient values for Examples V-X. Further, the
dust suppressing agent comprising polyurethane does not
significantly inhibit or prevent the dissolution of the Core
Particle B, as indicated by the low dissolution gradients.
[0073] It is to be understood that the appended claims are not
limited to express and particular compounds, compositions, or
methods described in the detailed description, which may vary
between particular embodiments which fall within the scope of the
appended claims. With respect to any Markush groups relied upon
herein for describing particular features or aspects of various
embodiments, it is to be appreciated that different, special,
and/or unexpected results may be obtained from each member of the
respective Markush group independent from all other Markush
members. Each member of a Markush group may be relied upon
individually and or in combination and provides adequate support
for specific embodiments within the scope of the appended
claims.
[0074] It is also to be understood that any ranges and subranges
relied upon in describing various embodiments of the present
invention independently and collectively fall within the scope of
the appended claims, and are understood to describe and contemplate
all ranges including whole and/or fractional values therein, even
if such values are not expressly written herein. One of skill in
the art readily recognizes that the enumerated ranges and subranges
sufficiently describe and enable various embodiments of the present
invention, and such ranges and subranges may be further delineated
into relevant halves, thirds, quarters, fifths, and so on. As just
one example, a range "of from 0.1 to 0.9" may be further delineated
into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e.,
from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which
individually and collectively are within the scope of the appended
claims, and may be relied upon individually and/or collectively and
provide adequate support for specific embodiments within the scope
of the appended claims. In addition, with respect to the language
which defines or modifies a range, such as "at least," "greater
than," "less than," "no more than," and the like, it is to be
understood that such language includes subranges and/or an upper or
lower limit. As another example, a range of "at least 10"
inherently includes a subrange of from at least 10 to 35, a
subrange of from at least 10 to 25, a subrange of from 25 to 35,
and so on, and each subrange may be relied upon individually and/or
collectively and provides adequate support for specific embodiments
within the scope of the appended claims. Finally, an individual
number within a disclosed range may be relied upon and provides
adequate support for specific embodiments within the scope of the
appended claims. For example, a range "of from 1 to 9" includes
various individual integers, such as 3, as well as individual
numbers including a decimal point (or fraction), such as 4.1, which
may be relied upon and provide adequate support for specific
embodiments within the scope of the appended claims.
[0075] The present invention has been described in an illustrative
manner, and it is to be understood that the terminology which has
been used is intended to be in the nature of words of description
rather than of limitation. Obviously, many modifications and
variations of the present invention are possible in light of the
above teachings. It is, therefore, to be understood that within the
scope of the appended claims, the present invention may be
practiced otherwise than as specifically described.
* * * * *