Note: Descriptions are shown in the official language in which they were submitted.
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WATER INSOLUBLE ENCAPSULATED ENZYMES
PROTECTED AGAINST DEACTIVATION
-BY HALOGEN BLEACHES
.
- Field of the Invention
The invention relates broadly to encapsulated enzymes
and particularly to water soluble encapsulated enzymes which
may be combined with a halogen bleach to form an effective
bleach/enzyme cleaning composition.
ackqround of the Invention
Enzymes are proteins synthesized by living organisms
;which can catalyze specific biochemical reactions such as the
conversion of starch to sugar (amylase), the hydrolysis of
fats to glycerol and fatty acids (lypase) and the hydrolytic
breakdown of prot~ins (protease). It is commonly believed
that enzymes are capable of catalyzing reactions only at a
limited number of specific sites commonly referred to as
"active sites".
Certain biological materials such as proteins, lipids
and polysaccharides can be difficult to remove from
substrates such as dishes, flatware and fabrics as such
biological materials are substantiallyi insoluble in
traditional cleàning media. To increase the solubility and
thereby effect removal of such biological materials, it is
~; known to employ an enzyme in a cleaning media to
catalytically assist in breaking down such materials into
insoluble monomeric and/or oligomeric molecules. Certain
types of enzymes such as amylase, lipase, and protease are
known to be particularly useful for such purposes as they can
effectively remove such materials from substrates without
significantly degrading the substrate being cleaned.
Halogen bleaches are a well known group of chemical
~-~ 35 compounds having the ability to remove stains such as those
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caused by coffee and tea from a substrate. Halogen bleaches
eliminate such stains by brea~ing down the large colored
organic molecules which form such stains into smaller
colorless molecules.
~- The cleaning actions of enzymes and halogen bleaches are
complementary, each affecting different aspects of the soils
typically found on dishes, flatware, and fabrics.
Accordingly, a superior~cleaning composition could be formed
by employing both an enzyme and a halogen bleach in a single
cleaning composition. However, while simple in theory such a
combination has proven to be difficult to implement as
halogen bleaches tend to instantly deactivate enzymes at
concentrations as low as 1 part active halogen per one
million parts cleaning media. While such deactivation of
enzymes is not fully understood, it is believed that the
halogen bleach affects either a change in the structure of
the enzyme's active site or a change in the shape of the
enzyme such that the enzyme's active site is no longer
available as a reactor site.
Early attempts to combine a halogen bleach and an enzyme
into a stable cleaning composition included the incorporation
of a stabilizing amount of a polysaccharide into the cleaning
composition, the incorporation of a stabilizing amount of a
nonionic polymer into the cleaning composit~on, and coupling
of the enzyme to an insoluble support. All of these early
attempts met with limited success, encouraging research into
other methods.
A slightly more successful attempt at combining a
halogen bleach and an enzyme into a stable cleaning
composition comprised encapsulation of the bleach in a time
release coating. The time release coating delayed the
release of the enzyme deactivating bleach for a time period
sufficient to allow the enzyme to perform its cleaning
function before it was deactivated. Unfortunately, this
attempt also met with limited success as it proved virtually
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impossible to economically prevent premature release of an
enzyme deactivating amount of the bleach.
A still slightly more successful attempt at combining a
halogen bleach and an enzyme into a stable cleaning
composition is disclosed in U.S. Pat. No. 4,421,664, which
teaches that enzyme activity may be maintained in the
presence of a halogen bleach by encapsulating the bleach in a
time release coating and incorporating an amount of a
reducing agent into the composition sufficient to
substantially instantaneously reduce all prematurely released
bleach. While this method has proven much more successful
than earlier attempts, it has been discovered that in order
for this method to work effectively it is necessary to employ
an encapsulated bleach having an extremely high encapsulation
efficiency which results in a prohibitively expensive
composition.
Accordingly, , a substantial need e~ists for an
inexpensive and stable cleaning composition containing both
an enzyme and a bleach wherein both the enzyme and the
bleach may perform their desired cleaning function.
Summary of the Invention
In a first aspect of my invention I have discovered a
composition capable of releasing active enzyme into an
a~ueous, chlorine bleach-containing media,~ithe composition
comprising an enzyme core encapsulated with an inner coating
of a bleach-neutralizing substance and an outer coating of a
;~ time-release substance. The encapsulated enzyme may further
comprise an initial coating of a time-release substance
between the enzyme and the bleach-neutralizing substance to
ensure that all chlorine bleach present in the solution has
been neutralized by the bleach-neutralizing substance beEore
the enzyme is released.
In a second aspect of my invention I have discovered a
composition capable of releasing active enzyme into an
aqueous, chlorine bleach-containing media, the composition
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comprising an enzyme core encapsulated with a time-release
substance designed to delay release of the enzyme into
solution ~or a first-time delay, and a bleach-neutralizing
substance encapsulated with a time-release substance designed
to delay release of the bleach-neutralizing substance into
solution for a second-time delay; the first-time delay being
longer than the second- time delay so that the bleach-
neutralizing substance will be released and completely
neutralize all chlorine bleach present in the solution before
the enzyme is released. The bleach-neutralizing substance
may be present either as a core material or as an inner
coating material on a diluent core. Further, the enzyme may
be encapsulated with an inner coating of bleach-neutralizing
substance between the enzyme and the time-release substance.
In 2 third aspect of my invention I have discovered a
composition capable of releasing active enzyme into an
aqueous, chlorine ,bleach-containing media, the composition
comprising an enzyme core encapsulated with a time-release
substance, a diluent core encapsulated with an inner coating
of a bleach-neutralizing substance and an outer coating of a
time-release substance, and a bleach-neutralizing substance
core encapsulated with a time-release substance. The enzyme
core and the bleach-neutralizing substance core may be
further encapsulated with an initial coat~ng of a bleach-
neutralizing substance between the core and the time-release
substance. Still further, the enzyme core may be coated with
the time-release substance so as to delay release of enzyme
into solution for a first time delay, and the cores of
diluent and bleach-neutralizing substance coated with the
time-release substance so as to delay release of diluent and
bleach-neutralizing substance into solution for a second time
delay; the first time delay being longer than the second time
delay so that all bleach-neutralizing substance present as
either a core material or a coating material on a diluent
core will be released and comp'etely neutralize all chlorine
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bleach present in the solution before the enzyme is released.
In a fourth aspect of my invention I have discovered a
cleaning composition particularly effective in warewashing
which comprises at least one of the encapsulated enzyme
containing compositions described above, a chlorine bleach,
and a-t least one additional detergent component.
-Commercially available enzymes typicall~ contain a
significant portion of an inert filler such as sodium
sulfate, sodium chloride, or the like.
As utilized herein, unless otherwise indicated, "wt-~
enzyme" refers to the active enzyme and any inert filler
employed in combination with the enzyme. For example, the
encapsulation of a mixture of 20 mg enzyme and 60 mg inert
filler with an inner coating of 10 mg bleach-neutralizing
substance and an outer coating of 10 mg time-release sub-
stance results in an encapsulated enzyme composition
comprising 80 wt-~ enzyme core.
As utilized herein, "bleach" refers to any chemical
agent capable of removing the color from a substrate by
oxidation~
As utilized herein, "active halogen" or "active
chlorine" refers to the halogen or chlorine actually present
in the compound having a valence o~ greater than -1.
For a detailed analysis of the meaning of "bleach",
"active chlorine", and "available chlorinè" see White,
George, Handbook of Chlorination, 1972, pp. 188-190.
Detailed Description of the Invention
Includina a Best ~ode
ENCAPSUL~TED EN~YME
.
In a first aspect of my~invention I have discovered a
composition capable of releasing active enzyme into an
aqueous, chlorine bleach containing media, the composition
comprising an enzyme core encapsulated with an inner coating
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of a bleach-neutralizing substance and an outer coating of a
time-release substance. The encapsulated enzyme may further
comprise an initial coating of a time-release substance
between the enzyme and the bleach-neutralizing substance to
ensure that all chlorine bleach has been neutralized by the
bleach-neutralizing substance beEore the en~yme is released.
Enzymes
Any enzyme capable of facilitating the removal of
biological soil from a substrate without substantially
damaging the substrate may be usefully employed in the
present invention. Such enzymes includes proteases, lipases,
amylases, and the like. The preferred enzyme or combination
of enzymes depends upon the substrate to be cleaned and the
types of soil to be removed. For reasons of ease of handling
and ease of encapsulation, the en2yme is preferably powdered
in form.
While commercially available enzymes typically contain a
significant portion of an inert filler such as sodium
sulfate, sodium chloride, or the like, I have found that the
presence of sush fillers does not affect the present
invention.
Proteases (including peptidases) are those enzymes which
attack and break down proteinaceous soils such as meat
residue, gravy, and blood. Proteases are classified in EC
class 3, subclass 3.4. While many varieties`and classes of
proteases are potentially suitable for use in the cleaning
composition of this invention, I have found the EC class
3.4.4 peptide peptido-hydrolases such as subtilopeptidase A
(EC 3.4.4.16) to be particularly effective. A suitable
protease can be purchased from Novo Industries under the mark
Esperase~.
Lipases are those enzymes which attack and break down
fatty soils such as cooking oil, grease, and ice cream.
Lipases also belong to EC class 3, but are placed in subclass
3.1. While many varieties and classes of lipases are
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potentially suitable for use in the cleaning composition of
this invention, I have found the EC class 3.1.1 enzymes such
as the glycerol ester hydrolases (EC 3.1.1.3) to be
particularly effective. A suitable lipase can be purchased
from Enzyme Development under the mark Lipase 30,000.
Amylases are those enzymes which can attack and break
down-starch, polysaccharide, and cellulosic soils such as
potatoes, rice, oatmeal, and grass. Amylases also belong to
EC class 3, but are placed in subclass 3.2. While many
varities and classes of amylases are potentially suitable for
use in the cleaning composition of this invention, I have
found the EC 3.2.1 glycoses hydrolases such as alpha-l, 4-
glucan-4-glucanohydrolase (EC 3.2.1.1) r and alpha-l, 4-glucan
maltohydrolase ~EC 3.2.1.2) to be particularly effective. A
suitable amylase can be purchased from Novo Industries under
the mark Termamyl~.
The encapsulated enzyme can comprise from a trace up to
about 95 wt-%, based upon the total capsule, enzyme core.
However, to allow sufficient bleach-neutralizing substance to
be introduced into solution and to achieve an economical
balance between encapsulation efficiency and amount of
; coating substance employed, the capsule preferably comprises
about 50 to 80 wt-~ enzyme.
Bleach-Neutralizina Substance
In the first aspect of my invention, surrounding and
protectively encapsulating the enzyme core is an inner
coating of a bleach-neutralizing substance which, when
released into solution, reduces all active chlorine present
in the solution to a form which will not deactivate the
enzyme. The bleach-neutralizing substance should, of course,
be a stable solid at room temperature and be compatible with
the enzyme and all other components intended to be combined
with the encapsulated enzyme. Further, the bleach-
neutralizing substance should not damage the substrate to be
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cleaned.
Any composition capable of reducing active chlorine to a
form which will not deactivate an enzyme and which meets the
criteria set forth above, can be usefully employed in the
present invention. Suitable bleach-neutralizing substances
include sulf-oxy acids and salts thereof, hydrogen peroxide
producing compounds, sugars, and the like.
Sulf-oxy acids and the salts thereof are a well-known
group of compounds which possess the ability to neutralize
chlorine bleaches. For reasons of low cost, high performance,
and ease of availability, the alkali metal and ammonium salts
of sulf-oxy acids, such as ammonium sulfite ((NH4)2SO3), sodium
bisulfite (Na2SO3), sodium thiosulfite (Na2S203), sodium
metabisulfite (Na2S2O3), potassium metabisulfite (K2S2Os),
lithium hydrosulfite (Li2S2o4), and the like are preferred.
Sulf-oxy acids are readily available from a number of suppliers
including Allied Corporation under the mark Sulftech~.
Because of their odorless and noncorrosive nature, the
preferred chlorine bleach-neutralizing substances are those
compounds capable of producing hydrogen peroxide when placed
in solution. Such compounds include perborates, percarbonates,
perphosphates, persulfates, and the like. These compounds are
readily available from a number of suppliers including Interox
Peroxid-Chemie GmbH and Dupont. For reasons of cost and ease
of availability, the preferred hydrogen peroxide producing
source is sodium perborate monohydrate available from Interox
Peroxid-Chemie GmbH.
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The encapsulated enzyme can comprise about 1 to 95 wt-~,
based upon the total capsule, bleach-neutralizing substance.
However, to achieve an economical balance between encapsulation
efficiency and amount of coating substance employed and provide
sufficient bleach-neutralizing substance to ensure complete
neutralization of all active chlorine present in solution, the
capsule praferably comprises about -
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to 60 wt-~, based upon the total capsule, bleach-
neutralizing substance.
Time-Release Substance
In the first aspect of my invention, surrounding and
protectively encapsulating the enzyme core and the first
coa-ting of bleach-neutralizing substance is an outer coating
of a time-release substance. The time-release substance
delays release of the bleach-neutralizing su~stance and the
enzyme so that a bleach, used in combination with the cap-
sule, can perform its cleansing function before it is deac-
tivated by the bleach-neutralizing substance. The time-
release substance should, of course, be compatible with the
enzyme, the bleach-neutralizing substance, and all other
components intended to be combined therewith. Further, the
time-release substance should not damage the substance to be
cleaned. Any material meeting these two criteria and capable
of delayin~ the ,release of substantial amounts of the
bleach-neutralizing substance for about l to 20 minutes,
preferably about 2 to 6 minutes may be employed in the
present invention.
Generally, the time-release substance will comprise a
high molecular weight semisolid or solid fat, an inorganic
solid, a natural or synthetic polymer, or the like. For
reasons of excellent film formation, the~preferred time-
release substances are the natural and synthetic polymers.
; Suitable time-release polymers are well known in the art and
; include: cellulose derivatives such as sodium carboxymethyl
cellulose, sodium hydr~xyethyl cellulose, ethyl cellulose,
hydroxypropyl cellulose, hydroxypropyl methyl cellulose,
nitro cellulose, cellulose acetate phthalate, and hydroxypro-
pyl methyl cellulose phthalate; gelatin; starch; proteins;
fatty acids; waxes (including paraffin and ~icrocrystalline
waxes); polyacrylamide; polyacrylic acid; polyvinyl alcohol;
polyethylene glycol, etc. The use of these and other similar
time-release substances, including selection of an appropri-
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ate compound for a particular use, is well within the skill
of one of ordinary skill in the art.
Because of its ability to suspend soils in solution in
addition to its time-release characteristics, the preferred
time-release substance is carboxymethyl cellulose and salts
thereof. Suitable sodium carboxymethyl cellulose is avail-
able from a number of suppliers, including ~ercules, Inc.,
under the mark CMC-CLT0.
The encapsulated enzyme can comprise about 1-50 ~t-%,
based upon the total capsule, time-release substance. The
preferred wt-~ depends upon the particular substance employed
and how long the bleach is to be allowed to function before
it is deactivated by the bleach-neutralizing substance. For
use in ware and fabric washing, I have found that about 1-20
wt-~ ! based upon the total capsule, time-release substance is
typically satisfactory.
Initial Time-Release ~ubstance
Optionally, the encapsulated enzyme can comprise an
initial coating of a time-release substance between the
enzyme core and the bleach-neutralizing substance to ensure
that all of the active chlorine in solution has been neutral-
ized by the bleach-neutralizing substance before the enzyme
is released.
While I have found that excellent re~ults may be ob-
tained in the àbsence of this initial coating, it may beuseful in some cases such as when an unstable enzyme is
employed, a slow reacting reducing agent is employed or a
small amount of reducing agent is employed. The initial
coating of time-release substance can comprise any of the
time-release substances previously described.
The amount of initial coating required to ensure that
all active chloxine has been deactivated before the enzyme is
released depends upon the amounts and type of bleach-neutral-
izing substance and initial coating material employed.
~owever, I have found that about 0.5 to 5 wt-~, based upon
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the total capsule, initial coating material is typically
sufficient to prevent premature release.
COMaINATION OF ENCAPSULATED ENZYME AND
EN~APSULATED BLEACH-NEUTRALIZING SUBSTANCE
,
In a second aspect of my invention I have discovered a
composition which comprises an enzyme encapsulated in a
time-release substance designed to delay release of the
enzyme into solution for a first-time delay, and a bleach-
neutralizing substance encapsulated in a time-release
substance designed to delay release of the bleach-
neutralizing substance into solution for a second-time delay;
the first-time delay being longer than the second- time delay
so that the bleach-neutralizing substance will be released
and completely neutralize all active chlorine present in the
solution before the enzyme is released. The bleach-
neutralizing substance may be present either as a core
material or as a first coating on a diluent core. Further,
the enzyme may be encapsulated with -an inner coating of a
bleach-neutralizing substance between the enzyme and the
time-release substance. Still further, the enzyme may be
; initially encapsulated with a time-release substance.
Diluent `'
~ diluent core may be employed as a carrier for bleach-
neutralizing substance wherein the bleach-neutralizing
substance is coated onto the diluent. This is particularly
useful when the bleach-neutralizing substance does not
readily form substantially uniform granules. The use of a
diluent core allows both enzyme and diluent to be
simultaneously coated with bleach-neutralizing substance,
thereby simplifying manufacture.
Suitable diluents include sodium sulfate, sodium
chloride, etc.
The enzymes, chlorine bleach-neutralizing substances,
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time-release substances, and chlorine bleaches described
previously with respect to the first aspect are all equally
well suited for use in this aspect. The time-release
substance employed to coat the enzyme and the bleach-neutral-
S iz-ing substance may be the same or different. For ease of
manufacturing, they are preferably the same.
This composition is particularly useful when the ratio
of chlorine bleach-neutralizing substance to enzyme is s~o
large that there simply is not sufficient enzyme particles
upon which to attach sufficient chlorine bleach-neutralizing
substance.
Generally, the time-release layers should be designed to
prevent release of the bleach-neutralizing substance for at
least about 1 minute, preferably about 2 to 6 minutes, and
the enzyme should be protectively encapsulated for an addi-
tional .5-2 minutes after release of the chlorine bleach-
neutralizing substànce.
In this aspect the encapsulated enzyme particle can
comprise from a trace up to about 95 wt-%, preferably about
30-80 wt-% enzyme, about 0 to 10 wt-%, preferably about 0 to
;~ 5 wt-~ initial coating of time-release substance, about 0 to
95 wt-%, preferably about 10 to 60 wt-%, bleach-neutralizing
substance, and about 1-50 wt-%, preferably about 1-20 wt-%
outer coating of time-release substance; and~the encapsulated
chlorine bleach-neutralizing substance can comprise from a
trace up to about 95 wt-%, preferably 50 to 80 wt-% diluent
core, from a trace up to about 95 wt-%, preferably about S0-
80 wt-% chlorine bleach-neutralizing substance if employed as
the core or about 15-40 wt-% chlorine bleach-neutralizing
substance if employed as the first coat, and about 1-50 wt-%,
preferably about 1-20 wt-% time-release substance.
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COMBINATION OF ENCAPSULATED ENZYME,
ENCAPSULATED BLEAC~-NEUTRALIZING SUBSTANCE
AND ENCAPSULATED DILUENT HAVING A COATING OF
BLEACH-NEUTRALIZING SUBSTANCE
.
In a third aspect of my invention I have discovered a
composition which comprises an enzyme core encapsulated with
a time-release substance, a diluent core encapsulated with an
inner coating o~ a bleach-neutralizing substance and an outer
coating of a time-release substance, and a bleach-
neutralizing substance core encapsulated with a time-release
substance. Further, the enzyme and the bleach-neutralizing
substance cores may be encapsulated with an inner coating of
a bleach-neutralizing substance between the core and the
time-release substance. Still further, the time-release
coating on the enzyme core may be designed to delay release
of the enzyme into solution for a first time delay, and the
time release coating on the diluent core and the bleach-
neutralizing substance core designed to delay release of the
diluent and the bleach-neutralizing substance into solution
for a second time delay wherein the first time delay is
longer than the second time delay such that the bleach-
neutralizing substance core and coatings will be released and
completely neutralize all active chlorine~ present in the
solution before'the enzyme is released.
The enzymes, chlorine bleach-neutralizing substances,
time-release substances, and chlorine bleaches described
previously with respect to the first aspect are all equally
well suited for use in this aspect. The time-release
substance and bleach-neutralizing substance employed to coat
the enzyme, the bleach-neutralizing substance and the diluent
may be the same or different. For ease of manufacturing,
they are preferably the same.
This composition is particularly useful when the ratio
of chlorine bleach-neutralizing substance to enzyme is so
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large that there is insufficient enzyme particles upon which
to attach sufficient chlorine bleach-neutralizing substance.
Generally, when encapsulating the enzyme, bleach-
neutralizing substance and diluent to achieve early release
of the bleach-neutralizing substance, the time-release layers
should be designed to prevent release of bleach-neutralizing
substance for at least about 1 minute, preferably about 2 to
6 minutes, and the enzyme should be protectively encapsulated
for an additional 0.5-2 minutes after release of all of the
bleach-neutralizing substance into solution.
In this aspect the encapsulated enzyme particle can
comprise from a trace up to about 95 wt-%, preferably about
30-80 wt-~ enzyme, about 0 to 10 wt-~, preferably about 0 to
5 wt-% initial coating of the time-release substance, about 0
to 95 wt-%, pre~erably about 10 to ~0 wt-%, bleach-
neutralizing substance, and about 1-50 wt-~, ~referably about
1-20 wt-% outer ,coating of time-release substance; the
encapsulated chlorine bleach-neutralizing substance can
comprise about 50-80 wt-~ chlorine bleach-neutralizing
substance core, about 0-~0 wt-% chlorine bleach-neutrali7ing
substance coating, and about 1-50 wt-%, preferably about 1-20
wt-% time-release substance; and the encapsulated diluent can
comprise about 30-80 wt-% diluent core, 10-60 wt-% chlorine
bleach-neutralizing substance and about 1-5~wt-%, preferably
about 1-2~ wt-%,' time-release substance.
I have found a particularly easy and effective method of
making encapsulated enzyme and bleach-neutralizing substance
which achieves the desired order of release, the method
comprising the steps of obtaining a diluent and a bleach-
neutralizing substance having a granular size substantiallythe same as the enzyme granules, simultaneously coating the
; enzyme, diluent and bleach-neutralizing substance granules
with a bleach-neutraIizing substance, and then coating the
once-coated granules with a time-release substance.
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CLEANING COMPOSITION
In a fourth aspect of my invention, the compositions of
the first, second and/or third aspects are combined ~ith a
chlorine bleach and at least one additional detergent
component to form an effective cleaning composition. The
chlorine bleach should be able to dissolve rapidly so that it
may perform its cleaning function before the chlorine
bleach-neutralizing substance is released. Many of the
well-known chlorine bleaches are rapidly soluble and would be
suitable for use in the invention.
Chlorine bleaches are a well-known group of compounds
capable of releasing active chlorine (C12) or hypochlorite
(OCL-) ions into solution. Suitable chlorine bleaches
include alkali metal dichloroiso- cyanurates, chlorinated
trisodium phosphate, alkali metal and alkaline earth metal
hypochlorites, monochloramine, dichloramine, nitrogen tri-
chloride, [(mono-tri-chloro)-tetra-(mono-potassium dichloro)-
]penta-isocyanurate, 1,3-dichloro-5,5-dimethyl hydantoin,
paratoluene sulfondi-chloroamide, trichlomelamine, N-chloro-
melamine, N-chlorosuccinimide, N,N'-dichloroazodicarbonamide,
N-chloro acetyl urea, N,N'-dichlorobiuret, chlorinated
dicyandiamide, trichlorocyanuric acid, dichlorogly- coluril,
and the like. For reasons of excellent bleaching perform-
ance, the preferred bleaches are hydrated and anhydroussodium dichlorisocyanurate and chlorinated trisodium
; phosphate. These bleaches are available from a number of
commercial sources including Olin Corporation under the mark
Clearon*CDB-56 (sodium dichloroisocyanurate dihydrate) and
Monsanto Industrial Chemical Co. under the mark ACL*-56.
While the cleaning composition can comprise only chlo-
rine bleach and encapsulated enzyme, for reasons of increased
cleaning ability it preferably further comprises at least one
additional detergent component such as a surfactant, a
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chelating agent, etc.
Suitable organic surfactants include anionic, nonionic,
amphalytic, zwitterionic, and mixtures thereof. While any
compatible surfactant may be employed, surfactant types which
are most widely used in detergent compositions include soaps
(i.-e., sodium or potassium salts) of fatty acids, rosin
acids, and tall oil; alkylarenesulfonates; alkyl sulfates,
including surfactants with both branched-chain and straight-
chain hydrophobes, as well as primary and secondary sulfate
groups; sulfates and sulfonates containing an intermediate
linkage between the hydrophobic and hydrophilic groups, such
as the fatty acylated methyl taurides and the sulfated fatty
monoglycerides; long-chain acid esters of polyethylene
glycol, particularly the tall oil ester; polyethylene glycol
ethers of alkyl phenols; polyethylene glycol ethers of long~
chain alcohols and mercaptans; fatty acyl diethanolamides;
and block copolymers of ethylene oxide and propylene oxide.
Suitable detergent fillers, builders, sequestrants, and
chelating agents include any of these well-recognized compon-
ents whose functions include maintaining an alkaline pH,suspending particulate matter in solution, preventing redepo-
sition of particulate matter, etc. A nonexhaustive list of
such detergent fillers, builders, sequestrants and chelating
agents includes condensed phosphates `isuch as sodium
tripolyphosphate, alkalis such as sodium carbonate, sodium
metasilicate, and sodium hydroxide, fillers such as sodium
sulfate, so~ium bicarbonate and sodium chloride, soil
suspending agents such as carboxymethylcellulose, and
chelators such as ethylene diamine tetraacetic acid and
polyacryllc acid.
The cleaning composition can comprise: about 0.1-1.5
wt-~, preferably about 0.5 to 1 wt-~ available chlorine,
about 0.3 to 20 wt-~, preferably about 1.5 to I5 wt-
~encapsulated enzymei an excess stoichiometric amount of an
encapsulated bleach-neutralizing substance for the active
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chlorine, and about 0 to 99 wt-%, preferably about 55 to 95
wt-~ additional detergent components. Preferably the
cleaning composition contains up to 10 wt-% surfactant as an
additional detergent component.
5The amount of chlorine bleach-neutralizing substance
employed must be sufficient to reduce all active chlorine
present in the solution. Preferably the stoichiometric ratio
of bleach-neutralizing substance to active chlorine is about
1:1 to 1.5:1 to ensure immediate deactivation of the active
chlorine.
Method of Pre~aration
Preparation of the encapsulated enzyme and the encapsu-
lated bleach-neutralizing substance can be accomplished in
any of the several known encapsulating processes such as pan
coating, roller coating, spray-congealing, etc. The prefer-
red process is a fluidized bed process encapsulation.
Basically, encapsulation in a fluidized bed comprises
the steps of
(i) liquefying the coating materials by either
20melting the material or dissolving the material in a
suitable solvent (preferably water);
(ii) fluidizing the particles to be encapsulated
by placing the particles in a chamber and passing an oil
flow therethrough;
25(iii) coating the particles with the coating
material by spraying the liquefied coating material onto
the fluidized particles; and
(iv) allowing the coated particles to cool and/or
dry.
30The cleaning composition may be prepared by simply
blending all components together, being sure to minimize the
possibility of damaging the capsules.
Example I
Into a 32 liter container ~as placed 1.25 lbs. KL~CEL*E,
a hydroxypropyl cellulose purchased from Hercules, Inc., and
* ~rade-mark
~3~S~82
- 18 -
39.41 lbs. of soft water. The KLUCEL *E and soft water were
mixed until the KLUCEL *E was completely dissolved. Into a
fluidized bed was placed 23.75 lbs. TERMAMYL* 60T, a powdered
bacterial amylase purchased from Novo Industri a/s. The
TERMAMYL *60T was fluidized in the bed at an air pressure of
40 psi, and the bed heated to 105F. The entire amount of
KLUCEL*E solution was sprayed onto the fluidized TERMAMYL*60T
granules through a Gustav Schlick Nozzle, Model 941. The
fluidized bed was heated to 125F. and the encapsulated
10 TERMAMYL*60T dried therein for 1 minute. The capsules were
cooled to 100F. and re~oved from the bed. 24.5 lbs. of
- encapsulated TERMAMYL*60T was obtained.
Into the fluidized bed used above was placed 2.45 lbs.
of the encapsulated TERMAMYL* 60T and 27.86 lbs. granular
15 sodium sulfate. Into the 32 liter container was placed 5.68
lbs. sodium perborate monohydrate purchased from Interox
Peroxid-Chemie GmbH and 113 lbs. of soft water. The sodium
perborate monohydrate and water were agitated until the
sodium perborate monohydrate was completely dissolved.
The encapsulated TERMAMYL* 60T and sodium sulfate were
fluidized in the fluidized bed at an air pressure of 60 psi
and the bed heated to between 140 to 16~F. The entire
amount of sodium perborate monohydrate solution was sprayed
onto the fluidized TERMAMYL *60T and sodium sulfate granules~
The temperature of the fluidized bed was then adjusted to
remain between 1~2 to 150F., and the encapsulated granules
allowed to dry. Into the 32 liter container was placed 2
lbs. KLUCEL*~ and 60 lbs. of soft water. The KLUCEL* E and
soft water were agitated until the KLUCEL *E was completely
dissolved. After the coating of sodium perborate monohydrate
dried, the KLUCEL~E solution was sprayed onto the once coated
granules forming capsules with a first coating of sodium
perborate monohydrate and a second coating of KLUCEL*E. The
fluidized bed was heated to 170F. and the encapsulated
granules dried therein for 2 minutes. The capsules were
* Trade-mark
., ~ .
~3~S~
- 19 -
cooled to 100F. and removed from the bed. Capsules retain-
ing 90.4~ of the original enzyme activity were obtained.
Example II
Into a chlorine bleach solution of known concentration
was placed an amount of the composition formed in Example I
sufficient to create a 2~ stoichiometric bleach-neutralizing
excess of sodium perborate monohydrate. After allowing the
outer coat of KLUCEL E, the coat of sodium perborate mono-
hydrate, and the initial coat of KLUCEL E to dissolve, the
solution was tested and found to contain 27.0% of the initial
enzyme activity.
Exam~le III
Into a chlorine bleach solution of known concentration
was placed an amount of the composition formed in Example I
sufficient to create a 20~ stoichiometric bleach-neutralizing
excess of sodium perborate monohydrate~ Ater allowing the
outer coat of KLUCEL E, the coat of sodium perborate monohy-
drate, and the initial coat of KLUCEL E to dissolve, the
solution was tested and found to contain 54.6% of the initial
; 20 enzyme activity.
Example IV
Into a 32 liter container was placed 1.5 lbs. sodium
sulfate and 15 lbs. of soft water. The sodium sulfate and
soft water were mixed until the sodium sulfa~e was completely
dissolved.
Into a fluidized bed was placed 18 lbs. ESPERASE 4.OT, a
powdered bacterial protease purchased from Novo Industri a/s.
The ESPERASE 4.0T was fluidized in the fluidized bed at an
atomization pressure of 40 psi and the bed heated to 125 F.
The entire amount of sodium sulfate solution was heated to
120F. and sprayed onto the fluidized ESPERASE 4.0T granules
through a Gustav Schlick Nozzle, Model 941.
Into the 32 liter container was placed 4.67 lbs. sodium
perborate monohydrate purchased from Interox and 93.48 lbs.
of sott water. The sodl~m perb~rate monohydrate and water
' - :
13~S0~2
- 20 -
were agitated until the sodium perborate monohydrate was
completely dissolved. The fluidized bed was heated to
130F., the sodium perborate monohydrate solution maintained
at less than 115F, and the entire amount of sodium perborate
monohydrate solution sprayed onto the once coated fluidized
granules. Into the 32 liter container was placed 1.5
lbs. CMC-CLT, a sodium carboxymethyl cellulose purchased from
Hercules, Inc., and 49.5 lbs. of soft water. The CMC-CLT and
soft water were mixed until the CMC-CLT was completely
dissolved. Finally, the CMC-CLT solution was maintained at
less than 130F. and the entire amount thereof sprayed onto
the twice coated fluidized granules.
The fluidized bed was then heated to 130 ~. and the
thrice encapsulated granules dried therein for 1 minute, then
cooled to 100 F. and removed from th~ bed.
Example V
Into a beaker; equipped with a laboratory stir bar and
plate was placed 0.10 grams sodium dichloroisocyanurate
dihydrate, 100.6 ~rams deionized water, and 0.34 grams
encapsulated enzyme formed in Example IV. The mixture was
~ vigorously agitated and complete neutralization of active
; chlorine found to take approximately 3 minutes. The result-
ant solution was found to have an enzyme activity of 2.28 knp
units per gram of encapsulated enzyme reprèisenting a reten-
tion of 80~ of the theoretical activity.
Example VI
Into a 2 liter container was placed 470.5 grams sodium
sulfate and 1600 grams soft water. The sodium sulfate and
- soft water were mixed until the sodium sulfate was completely
dissolved.
Into a separate 1 liter container was placed 70.5 grams
of a 3000 molecular weight polyacrylic acid and 211.5 grams
soft water. The polyacrylic acid and soft water were mixed
~; until the polyacrylic acid was completely dissolved.
Into a fluidized bed was placed 352.9 grams ESPERASE
.~, .
~ ,
:
~3(~5;(1 ~32
- 21 -
4~0M, a powdered bacterial protease purchased from Novi
Industri a/s. The ESPERASE 4.0M was fluidiæed in the bed and
the bed heated to 80F. The entire amount of sodium sulfate
solution was heated to 84F. and sprayed onto the fluidized
ESPERASE 4.OM granules.
- The fluidized bed was heated to 110F. and the entire
amount of the polyacrylic acid solution heated to 90F. and
sprayed onto the once coated granules. The fluidized bed was
heated to 120 F. and the twice-coated granules dried
therein, and then cooled to 100F. and removed from the bed.
Example VII
Into a beaker equipped with a laboratory stir plate, was
placed 0.4 grams sodium dichloroisocyanurate dihydrate
purchased from the FMC Corp. and 150 grams soft water heated
to 140F., and 1.0 gram of the encapsulated enzyme formed in
Example VI. The mixture was vigorously agitated and found to
effect complete neùtralization of active chlorine. An EMPA
116 test cloth was placed in the solution and indicated
enzyme activity.
The specification and Examples above are presented to
aid in the complete nonlimiting understanding of the inven-
tion. Since many variations and embodiments of the invention
can be made without departing from the spirit and scope of
the invention, the invention resides in t~`e claims herein-
after appended.
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