Process for making polymer matrix capsules containing large hydrocarbon drops suitable for incorporating large size actives to be used in liquid detergent compositions

The present invention relates to a process for preparing matrix capsules having hydrocarbon cores sufficiently large to contain large size particle actives which process comprises dispersing actives in hydrocarbon core material, and dispersing the active containing hydrocarbon in a polymer solution to form a polymer matrix emulsion of drops of said core material in said solution. The key to the invention is to obtain the dispersion by utilizing low shear rates previously uncontemplated using the standard shearing machinery of the art. This in turn is accomplished by maintaining the core within defined rheological parameters. By using lower shear rates, applicants were unexpectedly able to prepare capsules capable of stably incorporating large size actives in the core.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention relates to polymer matrix capsules which comprise 
actives dispersed in a hydrocarbon core material (in the form of 
hydrocarbon drops containing the actives) wherein the hydrocarbon material 
containing the actives is in turn dispersed in a polymer matrix. The 
capsules are generally made by (1) dispersing actives into drops of a 
hydrocarbon core material; (2) then dispersing the active containing 
hydrocarbon core material into a polymer solution to form an emulsion of 
hydrocarbon drops in polymer solution; and (3) spraying the 
oil/hydrocarbon dispersed in polymer into a hardening solution to cure the 
polymer around the hydrocarbon core. The invention relates to an improved 
method of making the capsules wherein the hydrocarbon core drops can be 
made suitably large to incorporate large size actives such that the 
actives won't be readily released from the hydrocarbon core material when 
the hydrocarbon core material is being dispersed in polymer solution (step 
(2)). 
BACKGROUND 
Encapsulation of sensitive ingredients, especially detergent enzymes, has 
been in practice for a number of years. Techniques range from 
encapsulating the enzymes in a reverse micelle (see U.S. Pat. No. 
4,801,544 to Munk) to protecting them in a hydrocarbon fluid such as 
silicone oil and petroleum jelly (see U.S. Pat. No. 4,906,396 to Falholt 
et al.) or in a solid surfactant (see U.S. Pat. No. 4,090,973 to Maguire 
et al.) or in a polymer matrix (WO 92/20,771). In many of the prior 
inventions, the enzyme is used either as an aqueous solution or as a 
finely dispersed colloidal size solid (=1 .mu.m and less). In the 
particular invention where large enzyme particles were used (U.S. Pat. No. 
4,090,973), 1 .mu.m to 2 mm, the particles were dispersed in a hydrophobic 
core which was directly incorporated (dispersed) into the detergent 
formulation and not into a polymer matrix, as carried out in the present 
invention. The polymer matrix has been found to be necessary to achieve 
the desired enzyme stability in liquid detergent systems containing bleach 
particles. The dispersion of hydrocarbon core material into the polymer 
solution is one of the most challenging steps. 
Capsules comprising solid actives inside a hydrocarbon or oil core and 
surrounded by a hardened polymer solution are known, for example, from 
applicants' copending application numbers, U.S. Ser. No. 150,701 and U.S. 
Ser. No. 151,605, both to Tsaur et al. and both of which are incorporated 
by reference into the subject application. 
In these references, the capsule could be made using a "matrix capsule 
method" (such as described on page 25 of U.S. Ser. No. 150,701, for 
example) or using a "core shell" method such as described on page 37 of 
the same application. The matrix capsule method is characterized by the 
fact that the actives are found inside of drops of hydrocarbon core 
material rather than one large hydrocarbon core as in the core shell 
method. 
In the matrix capsule method of that invention, active material (e.g., 
enzyme) is mixed with a hydrocarbon material (e.g., silicone oil with 
dispersed enzyme particles). The hydrocarbon core drops containing enzyme 
are then dispersed in a polymer solution (e.g., Acrysol ASE-95) using an 
overhead mixer. The homogenizer/mixer used in that case cannot make 
droplets large enough under homogeneous mixing conditions to allow 
incorporation of large active particles. In other words, one can make 
large size particles, but the compositions will not properly mix. 
In the core shell method (different from the matrix capsule method of the 
invention), larger size actives can be incorporated using a specially 
designed triple nozzle, but applicants have found this system to be rate 
limiting and not suitable for commercial scale-up. 
U.S. Pat. No. 4,906,396 to Falholt discloses the encapsulation of enzyme 
particles in the size range of 1 .mu.m to 2 mm in a hydrocarbon core 
material such as silicone oil or petroleum jelly. The capsules made in 
that invention, however, fail to teach a polymeric shell around the 
hydrocarbon core. This shell is very important in boosting the stability 
of active, for example, in bleach containing liquids. 
WO 92/20,771 to Allied Colloids discloses capsules having a hydrocarbon 
core and polymeric shell. The core requires a hydrophobic matrix polymer 
to keep active from migrating too quickly out of an oil layer. This is not 
required in the present capsules. Moreover, active encapsulated by the 
process of that reference are in the colloidal range (about 1 .mu.m). 
Thus, droplet size of the core is in the 10-30 .mu.m range rather than in 
the 100-1000 .mu.m range required for large actives. Further, using the 
homogenizer recommended in that reference, applicants were unable to 
produce larger size droplets because of poor mixing. While not wishing to 
be bound by theory, it is believed that, because of the inherent design of 
the homogenizer, mixing will be extremely poor at the low shear rates 
required to make large droplets (accomplished by decreasing rotor speed or 
RPM). More specifically, these homogenizers are designed to operate at 
high shear rates (i.e., .gtoreq.10,000 s.sup.-1). That is, they are 
designed to make droplets much smaller (typically 100 times smaller) than 
those of the subject invention. 
Accordingly, in a matrix capsule method for making capsules, there is a 
need in the art for a way of producing large droplet sizes (required for 
containing large size actives) while still producing good mixing (i.e., 
maintaining stable capsules). 
SUMMARY OF THE INVENTION 
Applicants have found that if active containing hydrocarbon core drops are 
dispersed in polymer solution using a device producing a low (i.e., 10,000 
s.sup.-1 and below) but controlled shear rate, it is possible to retain 
large size hydrocarbon core droplets (i.e., 10 to 1000 microns) while 
maintaining good mixing. This in turn allows the incorporation of actives 
ranging in size from 0.01 to 500 microns while still providing a 
dispersion which is physically stable for at least 8 hours. Physical 
instability can be defined by either an increase in the droplet size which 
occurs as a result of flocculation followed by coalescence of drops; or by 
separation of the two phases such that the top organic layer constitutes 
at least 5% by volume of the total emulsion. The process of the invention 
allows the production of polymer matrix capsules comprising large size 
solid or liquid actives including actives dissolved in aqueous solution, 
said solution being physically stable as defined above. 
More particularly, the present invention provides a process for 
incorporating actives having a size of 0.01 to 500 microns into a capsule 
used in liquid detergent compositions wherein said capsule comprises (a) 
actives subject to degradation in said liquid detergent; (b) a hydrocarbon 
core surrounding said actives; and (c) a polymer shell surrounding said 
hydrocarbon core, wherein said process comprises 
(1) dispersing said actives into a hydrocarbon core material; and 
(2) dispersing said actives containing hydrocarbon core material in a 
polymer solution using a device which mixes the hydrocarbon material and 
said polymer solution; 
wherein no more than 50%, preferably no more than 25%, more preferably, no 
more than 10% of solid are released from the hydrocarbon core drops during 
dispersion; 
wherein the hydrocarbon core droplets remaining after dispersing in polymer 
solution are 10 to 1000 microns; preferably 100 to 1000, more preferably 
200 to 1000, more preferably 300 to 1000 microns in size; and 
wherein the dispersion of drops in polymer solution is physically stable 
(as defined above) for 8 hours or greater. 
Preferably, the device used to mix the hydrocarbon core drops and polymer 
solution is a flotation machine. This machine is conventionally used for 
beneficiation of mineral ores and, as far as applicants are aware, has not 
been used for dispersion/emulsification of oil in polymer solutions. 
Flotation machine can produce shear rates of less than 10,000 s.sup.-1, 
preferably less than shear 5000 s.sup.-1, more preferably less than about 
3500 s.sup.-1, even more preferably less than 1000 s.sup.-1, while still 
maintaining good mixing. 
Generally, after the active containing hydrocarbon drops are dispersed in 
polymer solution, the hydrocarbon/oil is sprayed into a hardening solution 
(e.g., acid electrolyte bath) to cure the polymer around the hydrocarbon 
core. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention is concerned with a process for making polymer matrix 
capsules such as those described in U.S. Ser. Nos. 150,701 and 151,605, 
both of which are incorporated by reference into the subject application. 
More particularly, the capsules made by the process of the invention 
comprise 
(a) an active subject to degradation by components in an aqueous liquid 
cleaning composition in which they are found; 
(b) a hydrocarbon core (in the matrix capsule, these are in the form of 
hydrocarbon core droplets each containing the active (a) rather than one 
large core containing active (a) such as is made in the core shell method 
which is not part of the subject invention); and 
(c) a polymer shell matrix surrounding the hydrocarbon core drops. 
The hydrocarbon/oil core drops of the invention are defined by meeting each 
of three defined criteria set forth below: (1) by their ability to retain 
active in the dispersion in an aqueous solution; (2) by their ability to 
withstand phase separation at ambient or elevated temperatures over time; 
and (3) by their ability to rapidly and effectively release the 
encapsulated actives in use. As noted, the oils must meet all three 
defined criteria to be selected as the oil component of the invention. 
According to the first criterion, the oil component is defined by its 
ability to retain at least 50% active, preferably 75%, more preferably 90% 
after adding the active in oil dispersion to an aqueous solution. 
Typically, the actives will stay in the oil for at least an hour and up to 
weeks and months if not more. 
A second criterion by which the oil component is defined is its ability to 
hold the active in place and to prevent the active from diffusing or 
precipitating out of the oil phase. The stability of active in oil 
dispersion can be determined by adding the active in oil dispersion to a 
10 ml graduated cylinder and measuring the phase separation of the active 
from the hydrophobic oil. It should be less than 10%, preferably less than 
5% of phase separation when measured at 37.degree. C. for 1 week. 
The last criterion used to define the oil component is its ability to 
rapidly and effectively release the active in use. The oil release 
property can be determined by a standard Terg-O-Meter washing method. 
Terg-O-Meter are well known in the art such as, for example Terg-O-Tometer 
UR7227. In these devices, generally, 500 mls of wash liquid are agitated 
at above 70 rpm for about 20 minutes using desired wash liquid. The 
capsules of the invention were tested using 1000 mls at 100 rpm for 15 and 
30 minutes in the range of 20.degree.-40.degree. C. 
The capsule should release more than 50%, preferably more than 70% of the 
active after the first five minutes of the wash cycle when measured at 
50.degree. C. 
The hydrophobic oil component can be a liquid or a semisolid at room 
temperature. Liquid oils alone with a viscosity of less than 10,000 
centipoises (cps) such as mineral oils, silicone oils or vegetable oils 
are not suitable for this invention and require modification. These oils 
do not have the capability to hold and retain hydrophilic actives and do 
not provide sufficient protection to the active in a liquid detergent. The 
preferred liquid oil components are oils containing hydrophobic particles 
with particle size less than 3.mu., preferably less than 1.mu., more 
preferably less than 0.1.mu.. Examples of such hydrophobic particles are 
hydrophobic silica such as Cabot's Cab-O-Sil TS 720 and Cab-O-Sil TS 530 
or Degussa's Aerosil 200; and hydrophobic clay such as Rheox's Bentone 
SD-1. These hydrophobic particles can be incorporated into the oil 
physically i.e., simply by mixing the oil with the hydrophobic particles 
or chemically, i.e., through the chemical interaction of oil with the 
surface of the particles. The preferred hydrophobic particles are 
submicron sized hydrophobically modified fumed silica such as Cab-O-Sil TS 
720. These hydrophobic particles can enhance the suspension of actives in 
the oil and also increase the capability of oil to retain the actives in 
an aqueous solution. Typically the amount of hydrophobic particles in the 
oil is less than 15%, preferably less than 10%, more preferably less than 
5% but more than 0.5% should be used. 
In preferred embodiments of the invention, the oil component is defined by 
the fact that it is a semisolid rather than a liquid at room temperature. 
Specifically, when the component has a melting temperature of from about 
35.degree. C. to 70.degree. C., preferably 40.degree. C. to 65.degree. C., 
the semisolids are found to retain the active more readily. Moreover, such 
materials release active under wash condition rapidly enough to give wash 
performances comparable to compositions in which enzymes have been newly 
added. Since these semisolid oils will also slow migration of actives out 
of the oil phase or slow migration of bleach and other harsh components 
toward the actives, they are again preferred. 
Examples of such semisolid oils are petrolatums such as Penreco's Penreco 
Snow, Mineral Jelly and Tro-Grees; Witco's Multiwax; and fats (e.g., 
glyceryl ester of C.sub.12 -C.sub.24 fatty acids) or fat derivatives such 
as mono-, di- or tri-glycerides and fatty alkyl phosphate ester. 
Hydrophobic particles such as hydrophobic fumed silica are also desirably 
incorporated into these semisolid oils to further enhance their ability to 
retain actives, especially when the capsule of this invention is processed 
or stored at a temperature close to or above the melting point of the 
semisolid oils. 
The rheological behavior of the appropriate core component (oil phase) can 
be described in terms of a Sisko rheological model (H. A. Barnes, J. F. 
Hutton and K. Walters; An Introduction to Rheology; 1989; Elsevier 
Publishers) described by: 
EQU .eta.=.eta..sub..infin. +k .gamma..sup.n-1 
where: 
.eta., .eta..sub..infin. --Viscosity at a given shear rate and infinite 
shear viscosity respectively; 
.gamma.--Shear rate; and 
k, n--Sisko constants. 
Most preferred hydrocarbon cores (oil phase) are those in which the value 
of k is in the range of 10,000 to 50,000, preferably 20,000 to 40,000; n 
is in the range of 0.2 to 0.6, preferably 0.3 to 0.5 and .eta..sub.28 is 
in the range of 50 to 2,000 centipoises, preferably 100 to 1000 
centipoises. 
These parameters describe a composition which is easy to mix (i.e., mixes 
easily at low shear rate) yet has a high viscosity at rest. 
The polymer suitable for the polymer shell of the capsule of the invention 
must be insoluble in the composition of the liquid cleaning product and 
must disintegrate or dissolve during the use of the product simply by 
dilution with water, pH change or mechanical forces such as agitation or 
abrasion. The preferred polymers are water soluble or water dispersible 
polymers that are or can be made insoluble in the liquid detergent 
composition. Such polymers are described in EP 1,390,503; U.S. Pat. No. 
4,777,089; U.S. Pat. No. 4,898,781; U.S. Pat. No. 4,908,233; U.S. 
5,064,650 and U.S. Ser. Nos. 07/875,872 and 07/875,194, all of which are 
incorporated by reference into the subject application. 
These water soluble polymers display an upper consulate temperature or 
cloud point. As is well known in the art (P. Molyneaux, Water Soluble 
Polymers CRC Press, Boca Raton, 1984), the solubility or cloud point of 
such polymers is sensitive to electrolyte and can be "salted out" by the 
appropriate type and level of electrolyte. Such polymers can generally be 
efficiently salted out by realistic levels of electrolyte (&lt;10%). Suitable 
polymers in this class are synthetic nonionic water soluble polymers 
including: polyvinyl alcohol; polyvinyl pyrrolidone and its various 
copolymers with styrene and vinyl acetate; and polyacrylamide and its 
various modification such as those discussed by Molyneaux (see above) and 
McCormick (in Encyclopedia of Polymer Science Vol 17, John Wiley, New 
York). Another class of useful polymers are modified polysaccharides such 
as carrageenan, guar gum, pectin, xanthan gum, partially hydrolyzed 
cellulose acetate, hydroxy ethyl, hydroxy propyl and hydroxybutyl 
cellulose, methyl cellulose and the like. Proteins and modified proteins 
such as gelatin are still another class of polymers useful in the present 
invention especially when selected to have an isoelectric pH close to that 
of the liquid composition in which the polymers are to be employed. 
From the discussion above, it is clear that a variety of hydrophilic 
polymers have potential utility as the polymer coating for the capsules of 
this invention. The key is to select an appropriate hydrophilic polymer 
that would be essentially insoluble in the composition (preferably a 
concentrated liquid system) under the prevailing electrolyte 
concentration, yet would dissolve or disintegrate when this composition is 
under conditions of use. The tailoring of such polar polymers is well 
within the scope of those skilled in the art once the general requirements 
are known and the principle set forth. 
The fraction of polymer solution (aqueous solution) which will form the 
polymer matrix continuous phase should be such that the ratio by weight of 
organic core to polymer solution is in the range of 0.001 to 100, 
preferably 0.01 to 10, and most preferably 0.05 to 5. 
The rheological characteristics of the polymer solution can be described in 
terms of a Sisko rheological model described earlier in the present 
specification. Most preferred polymer solutions are those in which k 
varies in the range of 500 to 20,000, more preferably 1,000 to 15,000; n 
varies in the range of 0.2 to 0.6, more preferably 0.3 to 0.5 and 
.eta..sub.28 varies in the ranges of 100 to 2,000 centipoises, more 
preferably 2,000 to 1,000 centipoises and most preferably 300 to 500 
centipoises. 
Again, this defines where viscosity is relatively high at rest, yet 
relatively low when mixing. 
Actives 
The active materials which are desired to be encapsulated by the capsule of 
this invention are those materials which will lose their activity in a 
cleaning product, especially a bleach-containing liquid cleaning product, 
if no hydrophobic oil coating is added according to this invention. The 
active materials protected by the oil layer may be a hydrophilic active 
(e.g., enzyme or bleach catalyst) or a hydrophobic active (e.g., perfume) 
and can be solid, liquid or in aqueous solution. If it is a solid 
material, the particle size of the active are typically 0.01 to 500.mu., 
preferably 0.01 to 400.mu., more preferably 0.01 to 50.mu.. Large size 
active particles of 250-500.mu., preferably 100-400.mu. can be readily 
made using the process of the invention, but due to formulation 
constraints, more typically, the particles have an average size of about 
50 to 100.mu.. Of course, since a hydrophobic active is generally readily 
protected by an oily layer and is generally not readily degraded by harsh 
components in composition, the benefits of the invention are more readily 
apparent when the active ingredient is a hydrophilic one. Hydrophilic 
active materials include enzymes, bleach catalysts, peracid bleaches, 
bleach activators and optical brighteners. 
One preferred ingredient of the capsules disclosed herein is an enzyme. The 
enzymes may be amylases, proteases, lipases, oxidases, cellulases or 
mixtures thereof. The amylolytic enzymes for use in the present invention 
can be those derived from bacteria or fungi. Preferred amylolytic enzymes 
are those described in British Patent Specification No. 1,296,839, 
cultivated from the strains of Bacillus licheniformis NCIB 8061, NCIB 
8059, ATCC 6334, ATCC 6598, ATCC 11,945, ATCC 8480 and ATCC 9945A. A 
particularly preferred enzyme is an amylolytic enzyme produced and 
distributed under the trade name, Termamyl, by Novo Industri A/S, 
Copenhagen, Denmark. These amylolytic enzymes are generally sold as 
granules and may have activities from about 2 to 10 Maltose 
units/milligram. The amylolytic enzyme is normally included in an amount 
of from 1% to 40% by weight of the capsule, in particular from 5 to 20% by 
weight. 
The actives may also be a proteolytic enzyme. Examples of suitable 
proteolytic enzymes are the subtilisins which are obtained from particular 
strains of B. subtilis and B. licheniformis, such as those commercially 
available under the trade names Maxatase, supplied by Gist-Brocades NV, 
Delft, Netherlands, and Alcalase, supplied by Novo Industri A/S, 
Copenhagen, Denmark. Particularly preferred are the proteases obtained 
from a strain of Bacillus having a maximal activity throughout the pH 
range of 8-12, being commercially available under the trade names of 
Esperase and Savinase, sold by Novo Industri A/S. These proteolytic 
enzymes are generally sold as granules and may have enzyme activities of 
from about 500 to 50,000 glycine units/milligram. The proteolytic enzyme 
is normally included in an amount of from about 1% to about 40% by weight 
of the capsule, in particular of from 5% to 20% by weight. 
Lipolytic enzymes may also be included in order to improve removal of fatty 
soils. The lipolytic enzymes are preferably included in an amount of from 
about 1% to about 40%, preferably from 5% to 20% by weight. Cellulase 
enzymes may be used in an amount from about 1% to 40% by weight of the 
capsule. 
The total content of the enzyme in the capsules of the present invention is 
from about 1% to about 40%, preferably from about 3% to about 15%. 
It should be understood that the enzyme may also be a genetically 
engineered variation of any of the enzymes described have engineered to 
have a trait (e.g., stability) superior to its natural counterpart. 
The protected actives may also be peroxygen compound activators, peracid 
bleaches, bleach catalysts, optical brighteners or perfumes. 
Peroxygen compound activators are organic compounds which react with the 
peroxygen salts (e.g. sodium perborate, percarbonate, persilicate) in 
solution to form an organic peroxygen acid as the effective bleaching 
agent. Preferred activators include tetraacetylethylenediamine, 
tetraacetyglycoluril, glucosepentaacetate, xylose tetraacetate, sodium 
benzoyloxybenzene sulfonate and choline sulfophenyl carbonate. The 
activators may be released from the capsule to combine with peroxygen 
compound in the composition. 
When activator is included, the ratio between the peroxygen in solution and 
the activator lies in the range of from 8:1 to 1:3, preferably 4:1 to 1:2, 
and most preferably is 2:1. 
Although peroxyacids are generally contemplated for use in the composition 
rather than the capsule, peroxyacid compounds may be used as the active in 
the capsule as well, particularly in compositions where conditions are so 
harsh as to deactivate the peroxyacid. 
Generally the peroxyacids are amido or imido peroxyacids and are present in 
the range from about 0.5 to about 50%, preferably from about 15 to about 
30% by weight of the capsule. Preferably, the peroxyacid is an amide 
peracid. More preferably, the amide is selected from the group of amido 
peracids consisting of N,N'-Terephthaloyl-di(6-aminopercarboxycaproic 
acid) (TPCAP), N,N'-Di(4-percarboxybenzoyl)piperazine (PCBPIP), 
N,N'-Di(4-Percarboxybenzoyl)ethylenediamine (PCBED), 
N,N'-di(4-percarboxybenzoyl)-1,4-butanediamine (PCBBD), 
N,N'-Di(4-Percarboxyaniline)terephthalate (DPCAT), 
N,N'-Di(4-Percarboxybenzoyl)-1,4-diaminocyclohexane (PCBHEX), 
N,N'-Terephthaloyl-di(4-amino peroxybutanoic acid) (C.sub.3 TPCAP analogue 
called TPBUTY) N,N'-Terphthaloyl-di(8-amino peroxyoctanoic acid) (C.sub.7 
TPCAP analogue called TPOCT), N,N'-Di(percarboxyadipoyl)phenylenediamine 
(DPAPD) and N,N'-Succinoyl-di(4-percarboxy)aniline (SDPCA). Such compounds 
are described in WO 90/14,336. 
Other peroxyacids which may be used include the amidoperoxy acids disclosed 
in U.S. Pat. Nos. 4,909,953 to Sadowski and U.S. Pat. No. 5,055,210 to 
Getty, both of which are incorporated by reference into the subject 
application. 
Also, the active inside the compounds may be a bleach catalyst (i.e. for 
activating peracids found in the composition outside the capsule). 
Examples of such catalysts include manganese catalysts of the type 
described in U.S. Pat. No. 5,153,161 or U.S. Pat. No. 5,194,416, both of 
which are incorporated by reference into the subject application; 
sulfonomine catalysts and derivatives such as described in U.S. Pat. Nos. 
5,041,232 to Batal, U.S. Pat. No. 5,045,223 to Batal and U.S. patent No. 
5,047,163 to Batal, all three of which are incorporated by reference into 
the subject application. 
More particularly, manganese catalysts include, for example, manganese 
complexes of the formula: 
EQU LMn (OR).sub.3 !Y IV 
wherein 
Mn is manganese in the +4 oxidation state; 
R is a C.sub.1 -C.sub.20 radical selected from the group consisting of 
alkyl, cycloalkyl, aryl, benzyl and radical combinations thereof; 
at least two R radicals may also be connected to one another so as to form 
a bridging unit between two oxygens that coordinate with the manganese; 
L is a ligand selected from a C.sub.3 -C.sub.60 radical having at least 3 
nitrogen atoms coordinating with the manganese; and 
Y is an oxidatively-stable counterion. 
The sulfonomines include compounds having the structure: 
EQU R.sup.1 R.sup.2 C.dbd.NSO.sub.2 R.sup.3 
wherein: 
R.sup.1 may be a substituted or unsubstituted radical selected from the 
group consisting of hydrogen, phenyl, aryl, heterocyclic ring, alkyl and 
cycloalkyl radicals; 
R.sup.2 may be a substituted or unsubstituted radical selected from the 
group consisting of hydrogen, phenyl, aryl, heterocyclic ring, alkyl, 
cycloalkyl, R.sup.1 C.dbd.NSO.sub.2 R.sup.3, nitro, halo, cyano, alkoxy, 
keto, carboxylic, and carboalkoxy radicals; 
R.sup.3 may be a substituted or unsubstituted radical selected from the 
group consisting of phenyl, aryl, heterocyclic ring, alkyl, cycloalkyl, 
nitro, halo and cyano radicals; 
R.sup.1 with R.sup.2 and R.sup.2 with R.sup.3 may respectively together 
form a cycloalkyl, heterocyclic, and aromatic ring system. 
Sulfonomine derivatives include compounds having the structure: 
##STR1## 
wherein: R.sup.1 may be a substituted or unsubstituted radical selected 
from the group consisting of hydrogen, phenyl, aryl, heterocyclic ring, 
alkyl and cycloalkyl radicals; 
R.sup.2 may be a substituted or unsubstituted radical selected from the 
group consisting of hydrogen, phenyl, aryl, heterocyclic ring, alkyl, 
cycloalkyl, 
##STR2## 
nitro, halo, cyano, alkoxy, keto, carboxylic and carboalkoxy radicals; 
R.sup.3 may be substituted or unsubstituted radical selected from the 
group consisting of phenyl, aryl, heterocyclic ring, alkyl, cycloalkyl, 
nitro halo, and cyano radicals; 
R.sup.1 with R.sup.2 and R.sup.2 with R.sup.3 may respectively together 
form a cycloalkyl, heterocyclic, and aromatic ring system. 
Bleach activators are particularly good candidates for bleach encapsulation 
both because they are used in very small amounts and because they are 
readily deactivated in solution. 
More specifically, bleach activators are used in an amount from about 1% to 
30% by weight of the capsule composition, preferably, 3% to 15% by weight. 
As mentioned above, the actives may also be optical brighteners or 
perfumes. 
Process 
The present invention revolves around an improved method for making the 
capsules defined above such that large size actives can be protected. It 
is extremely important to prepare capsules that protect large size 
actives, since majority of actives such as bleaches and enzymes are 
commercially available only in large sizes and milling them to smaller 
sizes can be prohibitive from economic, safety and stability standpoints. 
The key to this, in turn, is to be able to create an emulsion of 
hydrocarbon drop (disperse phase) in polymer solution (continuous phase) 
where the emulsion can be prepared while retaining droplets having a 
particle size of 10 to 1000 microns, preferably 50 to 1000, more 
preferably 100 to 1000, more preferably 200 to 1000, more preferably 300 
to 1000, and most preferably 400 to 1000 microns. 
In general, the homogenizers used to emulsify the droplets into the polymer 
solution have never been able to create droplets of this range. This is 
because, if the shear rate is too low, mixing is very poor (versus good 
mixing of subject invention) and a stable emulsion cannot be successfully 
made. That is, the equipment conventionally used to make oil in water 
dispersions (or emulsion) work efficiently only at shear rates of greater 
than about 10,000s.sup.-1. At these rates: 
(1) droplets produced are under 100 microns; and 
(2) solids inside the drops are released. 
At lower than 10,000 S.sup.-1, as noted, it is not generally possible to 
make stable emulsions. 
Unexpectedly, applicants have found that a flotation machine of the type 
used for beneficiation of mineral ores, under typical operating conditions 
for such machines, creates the type of shear (estimated shear rates of 
500-3000s.sup.-1) required to produce the droplet sizes and lack of 
actives release from drops required for the invention. 
Specifically, the process of the invention comprises: 
(1) dispersing active particles into hydrocarbon core drop material (this 
can be done as either using an overhead mixer or milling the solid 
active--hydrocarbon core mixture using any type of attrition device such 
as a ball mill or a stirred media mill); 
(2) dispersing the active containing hydrocarbon drops in a polymer 
solution to form a polymer matrix emulsion with the hydrocarbon drops as 
disperse phase and polymer solution as continuous phase; this step is done 
using a device which operates at shear rates low enough such that: 
(a) no more than 50%, more preferably no more than 25%, most preferably no 
more than 10% of the active is released from the drops after shearing to 
form the emulsion; 
(b) the hydrocarbon drops in the emulsion can be as large as 1000 microns, 
i.e., 10-1000 microns, preferably 100-1000, more preferably 200-1000, more 
preferably 300 to 1000, most preferably 400 to 1000 microns; and 
(c) the emulsion is physically stable for 8 hours or greater (physical 
stability as measured by no more than 5% phase separation). 
One device which can be used to create this low shear rate such that the 
conditions described above are met is a flotation machine such as is 
described in Society of Mineral Engineers Handbook N. L. Weiss Ed., 
Section 5, pg. 82-109! which is hereby incorporated by reference into the 
subject application. 
The emulsion can be made in the temperature range of 5.degree. to 
80.degree. C., preferably 10.degree. to 60.degree. C., more preferably 
15.degree. to 50.degree. C. and most preferably 20.degree. to 40.degree. 
C.; 
the concentration of fraction, expressed in weight, of the hydrocarbon 
drops/organic phase can be varied in the range of 0.1 to 99%, preferably 1 
to 90%, more preferably 5 to 50% and most preferably 10 to 25%; 
the loading of the active solids in the hydrocarbon drops/organic phase can 
be varied in the range of 0.001 to 99%, preferably 0.001 to 90%, more 
preferably 0.001 to 50% and most preferably 0.001 to 20%; 
the impeller speed can be varied in the range of 10 to 100,000 rpm, 
preferably 50 to 5000 rpm, more preferably 100 to 2000 rpm and most 
preferably 500 to 1000 rpm. 
After the emulsion is made, the matrix capsules of the subject invention 
are prepared by spraying the emulsion into a hardening solution to cure 
the polymer matrix around the hydrocarbon core drops; during spraying the 
liquid flow rate can be varied in the range of 0.001 to 100,000 gm/min., 
preferably 0.01 to 10,000 gm/min., more preferably 0.1 to 1,000 gm/min. 
and most preferably 1 to 100 gm/min; the mass ratio of liquid to air flow 
rates can be varied in the range of 0.001 to 100,000, preferably 0.01 to 
1000; more preferably 0.1 to 100 and most preferably 1 to 10; the spray 
height can be varied in the range of 1 to 1000 cm, preferably 5 to 500 cm 
and most preferably 10 to 250 cm. 
Unless stated otherwise, all percentages discussed in the examples and 
specification are percentages by wt. 
The following examples are included to further illustrate and describe the 
invention and are not intended to limit the invention in any way.

EXAMPLE 1 
This example is to compare the droplet sizes obtained using flotation 
machine relative to conventionally used homogenizers for producing 
emulsions. 
Conditions used were as follows: 
Aqueous phase=5 wt % PVA-ASE60 (2:1) solution with k=10,800, n=0.37 and 
.eta..sub.28 =325 centipoises. 
Organic phase=1:1 Tro-Grees: Petrolatum+15 wt. % sodium sulfate with 
k=25,600, n=0.06 and .eta..sub.28 =890 centipoises. 
Temperature=23.degree. C. 
______________________________________ 
Sample Mixing 
Amount.sup.1 
Time.sup.2 
Max Drop 
Mean Drop 
Equipment grams minutes Size Microns 
Size Microns 
______________________________________ 
Flotation machine.sup.3 
400.0 1.0 600 440 
Homogenizer.sup.3 
150.0 0.5 250 210 
______________________________________ 
.sup.1 Minimum amount required for the size of the equipment used. 
.sup.2 Minimum time required to obtain homogeneous mixing as observed 
visually. 
.sup.3 Operated at minimum agitation conditions at which mixing was 
homogeneous. 
The example shows that much larger droplet sizes can be obtained with the 
flotation machine than the conventionally used homogenizers, when the two 
machines are operated under their lowest possible shear rate (in other 
words speed) conditions at which homogeneous mixing as visually observed. 
The estimated shear rate of the flotation machine under the tested 
conditions is 1000 s.sup.-1 and that of the homogenizer is 3700 s.sup.-1 
(note, it was not possible to go below this shear rate while maintaining 
mixing). 
Flotation machine used in our experiments is a model D-12 laboratory 
flotation machine purchased from Denver Equipment Company, Colorado 
Springs, Colo., USA. Although only the machine from the above mentioned 
manufacturer was used in our experiments, any flotation machine supplied 
by various suppliers such as Wemco, Agitair etc., can be used to make 
emulsions of the type described in the present invention. 
EXAMPLE 2 
Solid Release From the Hydrocarbon Droplet to Polymer Solution During 
Emulsification 
Denver D12 Flotation Machine 
Impeller Speed=650 rpm 
Aq. Phase=5 Wt. % PVA-ASE 60 (2:1) Solution 
Org. Phase=1:1 Tro-Grees: Petrolatum plus 8 Wt. % Savinase Powder Protease 
Enzyme, Ex: Novo! 
Savinase Powder Particle Size about 1 to 50 microns 
Temperature=25.degree. C.; Aqueous Phase: Organic Phase=9:1 (wt./wt.) 
______________________________________ 
Source Emulsification 
% Enzyme Released 
Petrolatum 
Tro-Grees Time, Min. Into Polymer Solution 
______________________________________ 
Penreco Penreco 1.0 18.0 
3.0 28.0 
5.0 31.0 
Fisher Penreco 1.0 11.0 
3.0 15.0 
5.0 25.0 
______________________________________ 
This example shows that the amount of enzymes released depends both on the 
source of petrolatum as well as emulsification time. 
EXAMPLES 3-6 
These examples show the effect of material and process parameters on the 
droplet size obtained with the flotation machine. In all the experiments 
sodium sulfate approximately 10-50 .mu.m in size! was used as the solid 
but any other solid can be used. The petrolatum samples used in all the 
example shown henceforth are obtained from Penreco. 
EXAMPLE 3 
Effect of Disperse Phase Composition on Droplet Size 
Denver D12 Flotation Machine 
Aq. Phase=5 wt % PVA-ASE 60*(2:1) solution 
Impeller Speed=650 rpm 
Aq.: Org. Phase (Petrolatum:Tro Grees)*=9:1 (wt/wt) 
Agitation Time=2 min. 
Temperature=23.degree. C. 
______________________________________ 
Dis. Ph. Comp. 
D.sub.Vm D.sub.gV 
Petr.:Tro-Grees 
.mu.m .mu.m .sigma..sub.g 
______________________________________ 
1:3 161 143 1.68 
1:1 197 200 2.00 
3:1 Insufficient mixing; large clumps seen 
______________________________________ 
D.sub.Vm volumetric mean droplet diameter 
D.sub.gV volumebased geometric mean 
.sigma..sub.g geometric standard deviation 
This examples shows that droplet size increases with increase in viscosity 
ratio, but above a certain value mixing obtained is poor. 
*PVA--Polyvinyl alcohol Airvol 540; ex: Air Products! 
*ASE 60--Highly cross-linked polyacrylic acid ex: Rohm & Haas! 
*Petrolatum--Snow white petrolatum ex: Penreco! 
*Tro-Grees--Spray Tro-Grees ex: Penreco! 
EXAMPLE 4 
Effect of Disperse Phase (Org. Phase) Concentration on Droplet Size 
Denver D12 Flotation Machine 
Aq. Phase=5 wt % PVA-ASE 60 (2:1) solution 
Impeller Speed=650 rpm 
Org. Phase=1:1 Tro-Grees:Petrolatum+15 wt % Sod. Sulfate 
Temperature=23.degree. C. 
Agitation Time=2 min. 
______________________________________ 
Dis. Ph. Comp. 
D.sub.Vm D.sub.gV 
wt % .mu.m .mu.m .sigma..sub.g 
______________________________________ 
10.0 197 200 2.00 
14.3 381 400 1.81 
25.0* 210 200 1.90 
______________________________________ 
D.sub.Vm volumetric mean droplet diameter 
D.sub.gV volumebased geometric mean 
.sigma..sub.g geometric standard deviation 
* Unstable liquid; larger droplets found initially phase separated 
leaving the emulsion rich in small droplets. 
This example shows that larger droplets can be obtained by increasing the 
disperse phase (organic phase volume) concentration, but above a certain 
concentration (25 wt % in this case) the droplets get too large to be 
stable in the aqueous phase. 
EXAMPLE 5 
Effect of Solids Loading of the Disperse Phase (Organic Phase) on Droplet 
Size 
Denver D12 Flotation Machine 
Aq. Phase=5 wt % PVA-ASE 60 (2:1) solution 
Impeller Speed=650 rpm 
Org. Phase=1:1 Tro-Grees:Petrolatum+15 wt % Sod. Sulfate 
Temperature=23.degree. C. 
Agitation Time=2 min. 
Aq.: Org.=9:1 (wt/wt) 
______________________________________ 
Solids loading 
D.sub.Vm D.sub.gV 
(wt/wt) .mu.m .mu.m .sigma..sub.g 
______________________________________ 
15.0 280 282 1.60 
22.5 276 272 1.90 
30.0* Phase separation occurred with organic phase 
settling to the bottom of the vessel 
______________________________________ 
D.sub.Vm volumetric mean droplet diameter 
D.sub.gV volumebased geometric mean 
.sigma..sub.g geometric standard deviation 
This examples shows that increasing the solids concentration to 30.0 weight 
percent increases the density of the organic phase/hydrocarbon drops to a 
value (1.635 gm/cc in this case) at which phase separation occurs, at 
polymer concentration used in this example. 
It should be understood that at higher polymer concentrations, higher 
solids loadings can be achieved. 
EXAMPLE 6 
Effect on Impeller Speed on Droplet Size 
Denver D12 Flotation Machine 
Aq. Phase=5 wt % PVA-ASE 60 (2:1) solution 
Impeller Speed=650 rpm 
Org. Phase=1:1 Tro-Grees:Petrolatum+15 wt % Sod. Sulfate 
Temperature=23.degree. C. 
Agitation Time=2 min. 
Aq.: Org.-9:1 (wt/wt) 
______________________________________ 
Speed D.sub.Vm D.sub.gV 
rpm .mu.m .mu.m .sigma..sub.g 
______________________________________ 
550 310 310 1.80 
650 280 282 1.60 
750 220 205 2.00 
______________________________________ 
D.sub.Vm volumetric mean droplet diameter 
D.sub.gV volumebased geometric mean 
.sigma..sub.g geometric standard deviation 
This examples shows that, within the range tested, the droplet size is 
proportional to agitation speed and hence the shear rate. 
EXAMPLE 7 and 8 
These examples show conditions under which the emulsion can be sprayed in 
order to obtain capsules with desired properties. 
EXAMPLE 7 
This example is to show conditions under which the emulsion can be sprayed 
without rupturing the droplets. 
Effect of Spraying Condiitons on Emulsion Droplet Size 
Aqueous phase: 5 wt % PVA-ASE 60 (2:1) solution 
Organic phase: 1:1 Tro-Grees-Petrolatum+15 wt % Na.sub.2 SO.sub.4 
Emulsification: 
9:1 Aqueous:Organic phase 
Flotation machine, 650 rpm, 2 min. 
______________________________________ 
Pressure, psig 
Flow Rate, gm/min. 
Droplet diameter, .mu.m 
Liquid Air Liquid Air D.sub.Vm 
D.sub.gV 
.sigma. 
______________________________________ 
-- -- -- -- 236 220 1.54 
10 5 57.3 8.5 230 210 1.50 
10 55.2 13.6 294 300 1.60 
15 53.7 17.4 306 275 1.80 
20 5 183.4 8.5 307 278 1.60 
10 N/A N/A 266 256 1.90 
______________________________________ 
D.sub.Vm volumetric mean droplet diameter 
Dgm geometric mean 
.sigma. geometric standard deviation 
This examples shows that under conditions of liquid and air pressure used, 
the emulsion can be sprayed without rupturing the emulsion droplet. 
EXAMPLE 8 
Effect of Relative Velocity and Spray Height on Aerosol Particle Size and 
Morphology 
Aqueous phase: 5 wt % PVA-ASE 60 (2:1) solution 
Organic phase: 1:1 Tro-Grees-Petrolatum+15 wt % Na.sub.2 SO.sub.4 
Emulsification: 
9:1 Aqueous:Organic phase 
Flotation machine, 650 rpm, 2 min. 
______________________________________ 
Spray 
Pressure, psig Height., 
Liquid 
Air L/G U, m/s 
cm Diam., .mu.m & morphology 
______________________________________ 
10 5 6.75 22.5 120 &gt;300 .mu.m spheres with 
tails 
150 500-3000 .mu.m spheres 
with tails 
200 800-1500 .mu.m spheres 
______________________________________ 
U Superficial air velocity m/g 
L/G Liquid to gas mass ratio dimensions 
This example also shows that at liquid and air pressures of 5 and 10 psig 
respectively and using a spray height of 200 cm, discrete spherical 
capsules of 800-1500 .mu.m can be obtained. 
EXAMPLE 9 
Materials and Process Conditions for Typical Matrix Capsule Preparation 
EMULSIFICATION 
Aqueous phase: 5 wt. % PVA-ASE 60 (2:1) solution 
Organic phase: 15 wt. % Savinase Protease enzyme, ex: Novo! in 1:1 
Tro-grees:Petrolatum 
Aqueous/Organic phase=9:1 (wt/wt) 
Flotation machine, 600 rpm, 2 min. 
SPRAYING 
Two Fluid Spray Nozzle, 1500 .mu.m opening 
Air : 5 psig ; Liquid: 10 psig 
Spray height: 200 cm 
CAPSULE DIMENSIONS 
Average core size=250 .mu.m 
Capsule size=200-800 .mu.m 
The performance of enzyme capsules prepared under the conditions stated in 
Example 9 was tested against liquid enzyme unencapsulated enzyme! on a 
cotton test cloth stained with casein AS 10 test cloth, ex: Center for 
Test Materials! using a Tergo-to-meter. Tergo-to-meter is a laboratory 
standard equipment that mimics the dynamics of a washing machine. Details 
of Tergo-to-meter operation is given in the text. 
EXAMPLE 10 
Deterency Performance Comparision of Matrix Capsules and Liquid Savinase: 
Effect of Time and Temperature 
______________________________________ 
Performance Ratio 
Temp. .degree.C. 
Wash time: 15 min. 
Wash time: 30 min. 
______________________________________ 
20 0.46 0.58 
30 0.81 0.87 
40 0.85 0.95 
______________________________________ 
Performance ratio=Detergency with capsules/Detergency with unencapsulated 
enzyme 
This example shows that the detergency obtained with the encapsulated 
enzyme is close to that of unencapsulated enzyme, especially above 
30.degree. C. 
Detergency is defined by a value Delta Delta R which in turn, is defined as 
Delta R minus Delta R' where: 
Delta R is the reflectance value (reflectance unit is an arbitrarily 
defined unit) of a full detergent composition (i.e., containing actives, 
electrolyte and enzymes) minus the reflectance value of detergent 
composition having electrolyte only; thus Delta R takes into account the 
effect of actives plus enzymes; and 
Delta R' is the reflectance value of a detergent composition containing 
actives and electrolyte (but no enzymes) minus the reflectance value of a 
detergent composiiton having electrolyte only; thus Delta R' takes into 
account the effect of actives only. 
EXAMPLE 11 
Stability of Savinase liquid vs encapsulated Savinase powder in HDL with 
bleach of the following composition: 
______________________________________ 
Component Parts 
______________________________________ 
Water 24.8 
Sorbitol (70%) 15.8 
Glycerol 4.8 
Sodium borate 10 H.sub.2 O 
4.8 
Sodium citrate 2 H.sub.2 O 
9.5 
Narlex DC-1 (ex. National Starch & Chem.) 
3.0 
50% NaOH 5.4 
DB 100 (Dow Chem.) (Antifoam) 
0.1 
Alkylbenzene Sulfonic Acid (anionic) 
21.8 
Neodol 25-9 (nonionic) 
10.0 
TPCAP* (bleach) 3,300 ppm active oxygen 
______________________________________ 
*N,Nterephthaloyl di 6aminopercarboxycaproic acid. 
Half-life of liquid Savinase at 37.degree. C.&lt;1 day 
Half-life of encapsulated Savinase powder at 37.degree. C.=14 days 
This example shows that the capsules of the invention greatly improves 
half-life stability of an enzyme.