Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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DRY BLEACH AND STABLE ENZYME GRA~ULAR COMPOSITION
Robert W. Herdeman
s BACKGROUND OF THE INVENTION
This invention reiates to an improved dry bleach and stable
en~yme granular compositions.
During the last score of years the use of enzymes, especially
of microbial origin, has been more and more common. Enzymes
are used in, for example, the starch in~stry to produce glucose
and fructose by means of amylases, amylglucosidases and glucose
isomerases. In the dairy industry a vast tonnage of rennets is
used and in the detergent industry proteases are normally used
as additives in the washing powders to impart a better action on
proteinaceous stains on the laundry.
On July 7, 1970, C. E~. McCarty w~s granted U.S. Pat. No.
3,519,570 for enzyme-containing detergent compositions and a
process for conglutination of enzymes and detergents. U.S. Pat.
No. 3,784,476, van Kampen et al., issued Jan. 8, 1974, discloses
a particulate enzyme-containing detergent composition containing a
detergent surface-active agent, a water soluble builder salt and
discrete, shaped inorganic solids containing proteolytic or
amylolytic en2ymes. It should be noted that this patent does not
teach an enzyme granulate with alkaline buffer salt as defined
herein (pH of 7-11 ) used in combination with a peroxyacid bleach
as disclosed herein.
U.S. Pat. No. 4,106,991, Markensen et al., issued Aug. 15,
1978, discloses an improved formation for enzyme granula~es
comprising enzyme, inorganic salts, a granulation binder, and
finely divided cellulose fibers as 2 40~ by weight of the
granulate. Optionally, a waxy substance can be employed for
the granulating agent, or to coat the granulate.
The granulates so produced are reported by Markensen et
al. to have a higher physical stability and a higher resistance
against abrasion than granulates without cellulose fibers and,
. ... . . . ..
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consequently, a very low dust level. Markensen et al. ~oes not
disclose that use of alkaline buffer salts would tmprove the
enzyme stability in the presence of peroxyacid bleach.
After the development of the granulated and coated enzymes
5 presently offered to the detergent industry, the use of the
enzymes in detergents has grown steadily.
Making a storage stable mixture of enzyme containing
granulates and dry peroxyacid bleach granulates is a difficult
task. In spite of the fact that some commercially avaiiable enzyme
1~ granulates are advertised as "perborate bleach stable," they are
weak storagewise in the presence of strong peroxyacid bleach
granulates. It should be noted that peroxyacid bleach granulates
are relative newcomers to the dry commercial laundry detergent
and bleach markets. Tlle term "bleach" as used herein unless
15 ~therwise specified means peroxyacid bleach and the terms "per-
oxyacid bleach powder" and "peroxyacid bleach granulates" are
synonymous unless otherwise specified. The term "en7yme" as
used hereinafter means raw enzyme, unless otherwise specified.
The term "enzyme powder" means a mixture of raw enzyme and
20 inorganic salts.
SUI~MARY OF TIIE INVENTION
This invention relates to an improved dry bleach and stable
enzyme granular composition. The enzyme granulate comprises a
homogeneous mixture of proteolytic or amylolytic enzyme and
25 alkaline buffer salt. The improved enzyme granulate is stable
when mixed with peroxyacid bleach granulates.
OBJECTS
It is an object of the present invention to provide a dry
bleach and stable enzyme granular composition. Other objeçts will
30 become apparent in the light of this disclosure.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to an improved dry bleach and stable
enzyme granular composition. The enzyme granulate comprises a
homogeneous mixture of proteolytic or amylolytic en2yme and
35 alkaline buffer salt. The improved enzyme granulate is stable
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3551~)8
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when mixed with peroxyacid bleach granulates. The term 'igranu-
lar" as used herein means the composition comprising: (1) enzyme
granulates and (2) peroxyacid bleach granulates, unless otherwise
specified.
This invention has an improved water-soluble enzyme granu-
late containing enzymes, fillers and/or binders and an effective
amount of alkaline buffer salt to protect the enzyrne from de-
activation via contact with peroxyacid bleach granulate. The
alkaline buffer salt has a pH of from abo~Jt 7 to about 11. The
practical level of alkali buffer salt material contained in the
granulate is from about 3% to about 97 . 5~ by weight of the
enzyme granulate. An alkaline buffer salt material as used herein
is d~fined as a material havin~ an effective amount of alkaline
buffer salt and compatible inorganic salts. Some practical ratio
levels of raw (proteolytic and/or amylase) enzyme to alkaline
buffer salt material are from 1:4 to 1:200, preferably 1:6 to
1: 1 00 , and more preferably 1: 20 to 1: 50 .
The present invention, therefore~, provides a storage
stable granular composition comprising:
(I) an enzyme granulate including a homogeneous
mixture of 0.5% to 20% raw enzyme, 3% to 97.5%
alkaline buffer salt material, 2% to 40~
cellulosic filler and binder, with said enzyme
having an activity of about 0.25-10 Au/gram,
and
(II) a peroxyacid bleach granulate,
wherein said (~) and (II) have a weight ratio of from
about 1:1 to about 1:1500;
wherein said alkaline buffer salt material has a pH of
30 from 7 to 11;
wherein said raw enzyme and said alkaline buffer salt
material have a weight ratio of from 1:4 to 1:200; and
wherein said cellulosic filler and binder of said (I)
have a weight ratlo of about 1:1 to 10:1.
The improved enzyme granulate on a weight percentage
basis preferably comprises:
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TABLE 1
Enz~me Granulate Levels (%)
Ingredient Preferred Low High
Proteolytic Enzyme 4 0.5 15
Amylase Enzyrn~ 1 0 5
Alkaline Buffer Salt
Material 45 3.0 97.5
Cellulose Filler &
Binder 25 2.0 40
Optional Waxy Coating 25 o 57
The weight percentages used herein refer to the weight of the
granulate being discussed, unless otherwise specified.
The improved enzyme granulate preferably is made with a
raw enzyme level of from about 0.5% to about 20% (0.25 to 10
Au/gram), and more preferably from about 1% to about 10% (0.5
to 5 Au/gram) by weight of the total composition. Au equals
Anson units and is a term commonly used in the trade to describe
enzyme activity. The filler and binder in the enzyme
granulate can have a ratio of,from 10:1 to 1:1. A practical
level of cellulosic fillers in the total composition can be
from about 2% to about 36%.
The stability of the alkaline buffer salt material/
enzyme granulate of -this invention is further improved with
the inclusion of an antioxidant salt to the granulate. The
antioxidant is preferably used at a level of from 1% to 40%,
more preferably 2% to 30%. The enzyme granulate of this
invention is further improved if it has a coating of alkaline
buffer salt material including antioxidant with an overcoat
of water-soluble nonionic waxy material over said coating.
A coating level of at least 10% alkaline buffer salt material
by weight of the enzyme granulate is preferred. The waxy
overcoat is preferably used at a level of 10% to 30% and more
preferably 15% to 25% by weight of said granulate.
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Granular Compositions
The improved granular composition of this invention
is a mixture of peroxyacid bleach granulates, improved
enzyme granulates and, optionally, other laundry active
powders including so~teners, detergents, etc. Examples of
powdered detergent materials are disclosed in U.S. Pat.
No. 4,404,128, B.J. Anderson, issued Sept. 13, 1983.
Examples of detergent composition and builder salts are
disclosed in U.S. Pat. No. 3,784,476, van Kampen et al.,
issued Jan. 8, 1974. Examples of powdered peroxyacid
bleach granulates are disclosed in U.S. Pat. No. 4,473,507,
F.P. Bossue, issued Sept. 25, 1984! Suitable granular
compositions can be formulated within the following ranges:
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TABLE 2
Ingredient Weight %
Bleach granulate 0.5-98
Enzyme G ranu late 0 .1 -1 5
Brightener 0-3
Alkali metal builder salts~ 0-80
Anionic surfactant 2-30
Nonionic surfactant 1-10
Ammonium and sodium sulfate 0-80
Perfume 0-1
Other laundry ingredients/
additives, i.e., softeners 0-20
*Orthophosphates, pyrophosphates, tripolyphosphates, nitrilo-
triacetates, ethylenediamine tetraacetates, carbonates and
si l icates .
A preferred mixture is an snzyme-peroxyacid bleach granu-
lar composition comprising the alkaline buffer salt protected
enzyme ~ranulate of this invention and a peroxyacicl bleach
granulate having a weight ratio of from 1 :1 to 1 :1500 of enzyme
granulate to bleach granulate, preferably 1:3 to 1:30. Details of
such a preferred mixture is disclosed below.
The Alkaline Buffer Salt Material
The term "alkaline buffer salt material" as used herein means
a salt having a pH of 7-11 and which provides a comparable pH
for the enzyme granulate in the presence of acidic substances for
an extended period of time. Thus, the alkaline buffer salt
material useful in the present invention can include any one of a
number of suitable compatible inorganic salts which have a pl I of
about 7-11. A pH of 8-10 is preferred. The pH of a salt is
measured as a 10% solution of the salt. Some preferred alkaline
buffer salts are potassium bicarbonate, potassium carbonate,
tetrapotassium pyrophosphate, potassium tripolyphosphate, sodium
bicarbonate and sodium carbonate. Other suitable alkaline buffer
salts can be used.
~5~
The alkaline buffer salt material can constitute 97.5% of the
solids in the enzyme granulate. In this case at least 2~ is cel-
lulosic fibers and 0. 5% enzyme per Table 1 . However, other
compatible materials can be included as part of the alkaline buffer
salt material, e.g., other inorganic salts, fillers, binders, etc.
Calcium is a preferred component and can be added as calcium
sulfate or calcium chloride.
The Antioxidant
As used herein the term "antioxidant" means a substance
that opposes oxidation or inhibits reaction provided by oxygen or
peroxides. The antioxidant is an enzyme stability booster for the
alkaline buffer salt enzyme granulate. The antioxidant increases
the stability of the enzyme when used in conjunction with alkaline
buffer salt. The preferred en~yme granulate can contain an
antioxidant salt, preferably at a level of from 1-40%, and more
preferably 2-30% by weight of the enzyme granlJlate. Some pre-
ferred antioxidant salts are sodium sulfite, sodium bisulfite and
sodium thiosulfate. Other suitable antioxidant salts can be used.
The Enzyme Granulate
The enzyme granulate of the present invention has a particle
size of from 100 to 160~, preferably from about 200 to about
80~, more preferably 300-500
A preferred process for making enzyme granulates of this
invention comprises drum granulating an enzyme material, inor-
ganic salts, a granulation binder, a liquid phase granulating
agent, and finely divided cellulose fibers. In accordance with the
present invention the inorganic salts are selected to include an
effective amount of alkaline buffer salt material to protect the
enzyme from rapid deactivation upon exposure to peroxyacid
bleach granulates.
The process for the production of enzyme granulates com-
prises the introduction into a drum granulator of from 2 to 40% by
weight of cellulose in fibrous form, from 0 to 10% by weight of a
binder as herein defined, 0 . 5% to 20% enzyme and 3% to 97 . 5%
alkaline buffer salt material in an amount which generates the
intended enzyme activity in the finished granulate, a liquid phase
-- 7 --
granulating agent consisting of a waxy substance, as defined
herein, and/or water, in an amount of between 5 and 70% by
weight, whereby the maximum amount of waxy substance is 40% by
weight and the maximum amount of water is 70% by weight,
5 whereby all percentages are referring to the total amount of dry
substances, the sequence of the introduction of the different
materials being arbitrary, except that at least a major part of the
granulating agent is introduced after at least a substantial part of
the dry substances is introduced in the granula~or, whereafter
10 the granulate, if necessary, is dried in a conventional manner,
preferably in a fluid bed.
The ceilulose in fibrous form can be sawdust, pure, fibrous
cellulose, cotton, or other forms of pure or impure fibrous cel-
Iulose. Several brands of cellulose in fibrous form are on the
15 market, e.g., CEP~ and ARRt)CEL*, In a publication from
Svenska Tramjolsfabrikerna AB, "Cepo Cellulose Powder, " it is
stated that for 'Cepo S/20'*cellulose the approximate minimum fiber
length is 50~, the approximate average fiber length is 16~,
the approximate maximum fiber width is 50~ and the approximate
20 average fiber width is 3~ . Also, ît is stated that CEPO SS/200
cellulose has an approximate maximum fiber length of 1 50f~, an
approximate average fiber length of 5,~, an approximate maximum
fiber width of 4~4 and an approximate average fiber width of
2,~. Cellulose fibers with these dimensions are very well suited
25 for the purpose of the invention.
The binders usecl in the process are the binders convention-
ally used in the field of granulation with a high melting point or
with no melting point at all and of a nonwaxy nature, e.g.,
polyvinyl pyrrolidone, dextrin, polyvinylalcohol, and cellulose
30 derivatives, including for example hydroxypropyl cellulose, methyl
cellulose or CMC. A granulate cannot be formed on the basis of
cellulose, filler, enzyme, alkaline buffer salt material and a
binder, without the use of a granulating agent, as defined below.
The term "enzyme" as used herein means raw enzyme unless
35 otherwise specified. The term "enzyme powder" means raw
* Trademark (each instance)
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enzyme mixed with inorganic salts such as NaCI, CaCI2, etc. All
enzymes can be granulated by means of said process. Prefer-
ably, amylases and proteinases are granulated according to the
invention. Specific examples are ALCALASE (a Bacillus licheni-
formTs proteinase), ESPERASE* and SAVINASE (microbial alcaline
proteinases produced according to British Pat. No. 1,243,784) and
TERMAMYL ~ Baccilus licheniformis amyiase). The enzyme can
be introduced into the granulator as a predried milled powder or
as a solution, for example, a concentrated enzyme solution pre-
10 pared by ultrafiltration, reverse osmosis or evaporation.
The granulating agent is water andlor a waxy substance.
The granulating agent is always used as a liquid phase in the
granulation process; the waxy substance if present therefore is
either dissolved or dispersed in the water or melted. By a "waxy
15 substance" is understood a "wax" which possesses all of the
following characteristics: (1) the rnelting point is between 30 and
100C, preferably between 40 and 60C, t2) the substance is of
a tough and not brittle nature, and (3) the substance possesses
substantial plasticity at room temperature.
Both water and waxy substance are granulating agents, i.e.,
they are both active during the formation of the granulate; the
waxy substance stays as a constituent in the finished granulate,
whereas the majority of the water is removed during the drying.
Thus, in order to refer all amounts to the finished, dry gran-
25 ulate, all percentages are calculated on the basis of total drygranulate unless otherwise specified, which means that water, one
of the granulating agents, is not added to the other constituents
when calculating the percentage of water, whereas the waxy
substance, the other granulating agent, has to be added to the
30 other dry constituents when calculating the percentage of waxy
substance. Examples of waxy substances are polyglycols, fatty
alcohols, ethoxylated fatty alcohols, higher fatty acids, mono-,
di- and triglycerolesters of higher fatty acids, e.g., glycerol
monostearate, alkylarylethoxylates, and coconut monoethanolamide.
* Trademark
** Trademark
*** Trademark
**** Trademark
5~
An illustrative summary of a process used to make an enzyme
granulate is:
1. Provide dry enzyme powder, cellulose fillers, alkaline buffer
salt materials, binders, etc.
2, Mix the dry powders of the granulate.
3, Wet the powder mixture with granulating agent, e.g., water
or waxy melt.
4. Process ~he wet powder mixture of Step 3 in a granulating
apparatus (rotating knife) until the granulate has the desired
particle size distribution.
A cylindrical Lodige type mixer FM 130 DIZ (U.S. Pat. No.
3,027,102) can be used in the process for this step. The mixer
is equipped with both plough shaped mixers mounted on a hori-
zontal ~axial) rotating shaft and a granulating device, consis~ing
of one Of more cross knives mounted on a shaft introduced into
the mixer through the cylindrical wall in a direction perpendicular
to the abovementioned horizontal rotating shaft (i.e., radial of
the cyiinder).
5. Dry in a fluidized bed the moist granulate of Step 4 until a
dryness which satisfies both the requirements of enzyme stability
and the requirements of free-flowing properties and mechanical
strength. Usually this will correspond to a water content less
than 109~, preferably less than 3~ and more preferably bone dry.
In the instances where the granulating agent is exclusively or
principally a waxy substance only cooling may be required.
6. Optionally coating the enzyme granulate with an alkaline
buffer salt coating, a waxy or some other compatible substance.
Optional Alkaline Buffer Sa!t Coating of the_Enzyme Granulate
The enzyme granulate produced in the present invention
can also be coated with alkaline buffer salt using any number of
known apparatuses. Coating in a fluidized bed is preferred.
Examples of suitabie apparatuses and processes are disclosed in
U.S. Pat. Nos. 3,196,827, Wurster and Lindlof, issued July 27,
1965; 3,253,944, Wurster, issued May 31, 1966; and 3,117,027,
Lindlof and Wurster, issued Jan. 7, 1964,
Trade mark
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U.S. Pat. No. 3,117,027 discloses a preferred fluidized bed
apparatus which can be used for coating the enzyme granulates
produced in the present invention. The fluidized bed will pro-
vide substantially uniformly enzyme coated granulates.
The coating process of the present invention comprises:
1. Forming an enzyme granulate having a particle size of from
100 to l 60~?, preferably 200 to 80~, with or without optional
waxy coating.
2, Coating the enzyme granulate with an effective amount of
alkaline buffer salt material, preferably at a level of from about
10% to about 10096 by weight of the enzyme granulate on a dry
weight basis. The enzyme granulate should be surrounded by
the coating and the coating should contain an effective amount of
alkaline buffer salt.
The protective coating is preferably applied to the enzyme
granulate as a 15g6 to 70% (preferably 20% to 50%) solids aqueous
solution in a fluidized bed. The temperature range of the solu-
tion can be about 60-82C (140-180F), and is preferably about
65-77C (150-170F). The air temperature of the fluidized bed is
45 to 77C for the coating/drying operation. The rate of addi-
tion of the coating solution and the rate of drying are dependent
on the solution concentration, temperature of air, volume, etc.
Calcium Present in Granulate and Coatin~
The enzyme granulate of this invention can be improved if it
contains from about 40 to 3000 ppm of calcium calculated as cal-
cium chloride. Calcium can be added to the granulate as calcium
chloride or calcium sulfate powder in the granulation process or
by using water containing a calcium content of 100-500 ppm,
preferably 170-300 ppm, calculated as calcium chloride in the
water used in the granulation and/or coating process.
Optional Waxy Coatin~ Materia!
A nonionic waxy material can be applied over the enzyme
granulate or over the alkaline buffer salt coated enzyme granu-
late. The practical levels of optional waxy coating material is up
~S5~8
to 57% by weight of the composition, preferably 5-30~. Examples
of such waxy coatings are polyethylene glycols, fatty alcohols,
ethoxylated fatty alcohols, higher fatty acids, mono-, di- and
triglycerolesters of fatty acids, e.g., glycerol monostearate,
5 alkylarylethoxylates and coconut monoethanolamide. Preferred
nonionic waxy substances are TAE22 ttallow alcohol condensed
with 22 moles of ethylene oxide per mole of alcohol), pEG 1500-
8000 (polyethyiene glycol of molecular weight 1500-8000) and
palmitic acid. Other waxy coatings having a melting point of at
10 least 38C, preferably at least 50C, can also be used. For
example, this waxy coating is melt~d (50-70C) and is sprayed
onto the granulate in a fluidized bed where oool air (15-30~C) is
applied to solidify the waxy coating.
EXAMPLE I
15A preferred enzyme granulate can be made uslng the pro-
cedure outlined above using the following ingredients:
I ng redient Wt%
Proteolytic Enzyme 4
Amylase Enzyme
Alkaline Buffer Salt
Material1 45
Cellulose Filler2 20
Binder3 (polyvinyl pyrrolidone) 5
Waxy Overcoat (PEG 1500) 25
20% KHCO3, 5% Na25O3, 20% CaCI2/NaCI
Cellulose Powder - CEPO S20
3 Selected from polyvinyl pyrrolidone, dextrin,
polyvinyl alcohols and cellulose clerivatives.
EXAMPLE l I
A 6 inch Wurster Fluidized Bed Coating Unit with a capacity
of about 1 liter san be used. The enzyme granulate of Example I
can be optionally coated as follows: 800 grams of enzyme granu-
35late are added to the fluid bed dryer. To this a 1,000 gram 70C
aqucous solution, containing 200 grams of potassium bicarbonate
* Trade mark
and 40 grams of sodiun sulfite, is sprayed on. The coated
enzyme granulate is then dried at a fluid bed temperature of 75C
to contain less than 0. 596 water. The coated enzyme granulate is
then removed from the fluid bed dryer and weighed to confirm
5 coating level.
About 800 grams of the alkaline buffer salt/antioxidant
salt-coated enzyme granulate is then placed back into the fluid
bed dryer. To this 200 grams of TAE22 are sprayed on at 55C
and allowed to cool in the dryer with air temperature 20C.
Final weight %:
Enzyme Granulate 61 . 54
Protective Coatin~:
Potassium Bicarbonate 15.38 )
Sodium Sulfite 3.08 )18.46
TAE22 Overcoating 20.00
Total 100 . 00%
The ratio of enzyme granulate to protective coating is about
3.3 to 1. The pH of the coating is 8.5.
EX AlvlPLE l l l
The enzyme granulates similar to that described in Examples
I or ll are dry mixed with peroxyacid bleach granulates.
Wt% G rams
Peroxyacid Bleach Granulate
Di pe roxydo-
decanedioic Acid 20.75
Dodecanedioic Acid1 . 85
Boric Acid 22 . 75
Na25O4 28 . 06
Sodium Acid
Py rophosphate 5 . 00
C1 3LAS 4 . 50
83 20
Enzyme Granulate of Example I or l l * 17 4
100 24
*2.0 Au/gram protease activity.
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The process used to make the peroxyacid bleach granulate in
Example lll is disclosed in U.S. Pat. No. 4,497,757, Beimesch and
Hortel, issued Feb. 2, 1985,
EXAMPLE IV
A detergent powder containing the following components:
Weight %
Diperoxydodecanedioic acid
bleach granulate (Ex . I l l ) 25
Enzyme granulates of
Example I or l l 2
Sodium salt of straight chain C12
alkylbenzene sulfonate 20
Sodium tripolyphosphate 35
Sodium sulfate 12
Sodium sil icate 4
Brightener
Perfume capsules 0 . 3
Water, perfume Balance
5~8
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EXAMPLE V
"A laundry additive containing the foliowing components:
Weight %
Diperoxydodecanedioic acid
bleach granulate* 90.2
Enzyme grànulates of
Example I or l l 2
Brightener and sodium siiicate 7
Perfume capsules 0. 3
Water Balance
~The peroxyacid bleach granulate of Example l l l is cut with
sodium sulfate to adust peroxyacid level to about 8~ of the
bleach granulate.
This invention offers an improved storage stable granular
composition comprising an enzyme granulate which is storage
stable with a peroxyacid bleach granulate, enabling them to be
used together in a detergent or laundry additive product for
20 combined bleaching and stain removal performance.
