U.S. patent application number 16/190685 was filed with the patent office on 2019-03-14 for microcapsules comprising hydroxyalkyl cellulose.
The applicant listed for this patent is BASF SE. Invention is credited to Emmanuel Julien Leon Christian Aussant, Ewelina Burakowska-Meise, Wolfgang Denuell, Addi Fadel, Ian Harrison, Thomas Soltys.
Application Number | 20190076812 16/190685 |
Document ID | / |
Family ID | 51932187 |
Filed Date | 2019-03-14 |
United States Patent
Application |
20190076812 |
Kind Code |
A1 |
Burakowska-Meise; Ewelina ;
et al. |
March 14, 2019 |
MICROCAPSULES COMPRISING HYDROXYALKYL CELLULOSE
Abstract
The application describes an aqueous dispersion of
microcapsules, wherein the shell of the microcapsules comprises at
least one polyuria and the core comprises one or more lipophilic
components with the proviso that the core does not contain a
fragrance, and having a percentage of the shell weight with
reference to the total weight of the capsules of 5 to 40% and
wherein the microcapsules have a volume average diameter of 15 to
90 .mu.m and the dispersion comprises hydroxyalkylcellulose and the
use of such a dispersion.
Inventors: |
Burakowska-Meise; Ewelina;
(Reichenbach (Lautertal), DE) ; Denuell; Wolfgang;
(Mannheim, DE) ; Soltys; Thomas; (Ludwigshafen,
DE) ; Aussant; Emmanuel Julien Leon Christian;
(Paris, FR) ; Fadel; Addi; (Paris, FR) ;
Harrison; Ian; (Poissy, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BASF SE |
Ludwigshafen |
|
DE |
|
|
Family ID: |
51932187 |
Appl. No.: |
16/190685 |
Filed: |
November 14, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15523953 |
May 3, 2017 |
|
|
|
PCT/EP2015/074826 |
Oct 27, 2015 |
|
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16190685 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 8/11 20130101; A61K
2800/412 20130101; A61K 8/84 20130101; A61K 9/4816 20130101; A61Q
19/00 20130101; A01N 25/28 20130101; C11D 17/0013 20130101; C11D
17/0039 20130101; C11D 3/3776 20130101; B01J 13/20 20130101; B01J
13/185 20130101; C11D 3/225 20130101; A61K 2800/10 20130101; C11D
3/3723 20130101; A61K 9/4858 20130101; A61K 8/731 20130101; A61K
8/8176 20130101 |
International
Class: |
B01J 13/18 20060101
B01J013/18; A61K 8/73 20060101 A61K008/73; C11D 3/37 20060101
C11D003/37; A61K 8/84 20060101 A61K008/84; A61K 8/11 20060101
A61K008/11; A61Q 19/00 20060101 A61Q019/00; B01J 13/20 20060101
B01J013/20; C11D 3/22 20060101 C11D003/22; C11D 17/00 20060101
C11D017/00; A61K 9/48 20060101 A61K009/48; A61K 8/81 20060101
A61K008/81; A01N 25/28 20060101 A01N025/28 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 7, 2014 |
EP |
14192187.4 |
Claims
1. An aqueous dispersion of microcapsules, wherein: a shell of the
microcapsules comprises at least one polyurea and a core comprises
one or more lipophilic components with the proviso that the core
does not contain a fragrance, and having a percentage of the shell
weight with reference to a total weight of the microcapsules of 5
to 40%; the microcapsules have a volume average diameter of 15 to
90 .mu.m; the dispersion comprises hydroxyalkylcellulose as a
stabilizing agent; and a ratio of the shell weight percentage to
the volume average diameter of the microcapsules is at most 0.7
.mu.m.sup.-1.
2. The microcapsule dispersion according to claim 1, wherein a
ratio of the shell weight percentage to the volume average diameter
of the capsules is at most 0.5 .mu.m.sup.-1.
3. The microcapsule dispersion according to claim 1, wherein a
nominal rupture stress of the capsules is in a range of 0.1 to 2
MPa.
4. The microcapsule dispersion according to claim 1, wherein the
lipophilic components are selected from components having a
solubility in water of .ltoreq.10 mg/mL at 20.degree. C.
5. The microcapsule dispersion according to claim 1, wherein a
viscosity of the dispersion is .ltoreq.4 Pa s, measured on a
rheometer with rotating discs at a shear rate of 21 s.sup.-1 and at
a temperature of 25.degree. C.
6. The microcapsule dispersion according to claim 1, wherein an
amount of the hydroxyalkylcellulose is 0.05 to 1.2% by weight based
on the total weight of the dispersion.
7. The microcapsule dispersion according to claim 1, wherein the
hydroxyalkylcellulose comprises at least one
hydroxyethylcellulose.
8. The microcapsule dispersion according to claim 1, wherein the
lipophilic component is selected from the group consisting of oil
bodies, UV-filters, biocides, dyes, emollients, vitamins,
cosmetically active ingredients, pharmaceutically active
ingredient, cosmetically and pharmaceutically acceptable
auxiliaries, detergents, and mixtures thereof.
9.-12. (canceled)
13. The microcapsule dispersion according to claim 3, wherein the
nominal rupture stress of the capsules is in a range of 0.2 to 1.5
mPa.
14. The microcapsule dispersion according to claim 3, wherein the
nominal rupture stress of the capsules is in a range of 0.4 to 1
mPa.
15. The microcapsule dispersion according to claim 1, wherein the
microcapsules have a percentage of the shell weight with reference
to a total weight of the microcapsules of 10 to 20%.
16. The microcapsule dispersion according to claim 1, wherein a
ratio of the shell weight percentage to the volume average diameter
of the capsules is in a range from 0.2 .mu.m.sup.-1.
17. The microcapsule dispersion according to claim 1, wherein a
ratio of the shell weight percentage to the volume average diameter
of the capsules is in a range from 0.2 .mu.m.sup.-1 to 0.6
.mu.m.sup.-1.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an aqueous dispersion of
microcapsules having a polyurea shell and a lipophilic core
material, microcapsules obtained by drying the aqueous dispersion
and the use of both thereof.
STATE OF THE ART
[0002] Microcapsules are spherical objects which consist of a core
and a wall material surrounding the core, wherein the core in
principal can be a solid, liquid or gaseous component which is
surrounded by the solid wall material. For many applications the
wall is formed by a polymer material. Microcapsules usually have a
volume average diameter from 1 to 1000 .mu.m.
[0003] A multitude of shell materials is known for producing the
wall of microcapsules. The shell can consist either of natural,
semisynthetic or synthetic materials. Natural shell materials are,
for example, gum arabic, agar agar, agarose, maltodextrins, alginic
acid or its salts, e.g. sodium alginate or calcium alginate, fats
and fatty acids, cetyl alcohol, collagen, chitosan, lecithins,
gelatin, albumin, shellac, polysaccharides, such as starch or
dextran, polypeptides, protein hydrolyzates, sucrose and waxes.
Semisynthetic shell materials are inter alia chemically modified
celluloses, in particular cellulose esters and cellulose ethers,
e.g. cellulose acetate, ethyl cellulose, hydroxypropylcellulose,
hydroxypropylmethylcellulose and carboxymethylcellulose, and also
starch derivatives, in particular starch ethers and starch esters.
Synthetic shell materials are, for example, polymers, such as
polyacrylates, polyamides, polyvinyl alcohol, polyvinylpyrrolidone
or polyurea.
[0004] Depending on the type of shell material and the production
process, microcapsules are formed in each case with different
properties, such as diameter, size distribution and physical and/or
chemical properties.
[0005] Polyurea core-shell microcapsules obtained by reaction of
two diisocyanates and a polyamine are well known in the art, for
example from WO 2011/161229 or WO 2011/160733. According to WO
2011/161229 or WO 2011/160733 the polyurea microcapsules are
prepared in presence of polyvinylpyrrolidone (PVP) as a protective
colloid.
[0006] WO 2012/107323 discloses polyurea microcapsules having a
polyurea shell comprising the reaction product of a polyisocyanate
with guanazole and an amino acid in presence of anionic stabilizers
or surfactants like anionic polyvinyl alcohol, such as Mowiol.RTM.
KL-506 sold by Kuraray.
[0007] EP-B-0 537 467 describes microcapsules prepared from
isocyanates which are containing polyethylenoxide groups, in the
presence of stabilizers like polyvinyl alcohol, e.g. partially or
totally saponified polyvinyl acetate.
[0008] According to WO 2007/096592 microencapsulation can take
place in an oil phase which is emulsified in a continuous aqueous
phase, generally stabilized by a surfactant system like polyvinyl
alcohols or carboxylated and sulphonated derivatives thereof.
[0009] These is a continuing demand for delivery systems that
allows controlled delivery of hydrophilic compounds under defined
application conditions. This comprises e.g. the delivery of a
cosmetically or pharmaceutically active component to a person or
animal.
[0010] Thus, several techniques are used to provide stable dosage
forms that allow a controlled release of these additives.
Encapsulated lipophilic components which are different from
perfume, are manufactured in the form of a dispersion of
microcapsules in an aqueous medium. It is important to ensure that
the distribution of the lipophilic component-containing capsules in
a dispersion is controlled in order that the microcapsules do not
phase separate from the aqueous dispersing medium and cream,
sediment or coagulate. In order to properly disperse and suspend
microcapsules within an aqueous dispersing medium, to provide a
composition with long time stability, dispersing aids are commonly
employed in the manufacture of those dispersions.
[0011] A wide variety of dispersing aids are known in the art and
include polysaccharides, pectine, alginate, arabinogalactan,
carageenan, gellan gum, xanthan gum, guar gum, acrylates/acrylic
polymers, starches, water-swellable clays, acrylate/aminoacrylate
copolymers, and mixtures thereof, maltodextrin; natural gums, such
as alginate esters; gelatine, protein hydrolysates and their
quaternized forms; synthetic polymers and copolymers, such as
poly(vinyl pyrrolidone-co-vinyl acetate), poly(vinyl
alcohol-co-vinyl acetate), poly(maleic acid), poly(alkyleneoxide),
poly(vinylmethylether), poly(vinylether-co-maleic anhydride), and
the like, as well as poly-(ethyleneimine), poly((meth)acrylamide),
poly(alkyleneoxide-co-dimethylsiloxane), poly(amino
dimethylsiloxane), and the like.
[0012] Despite the variety of dispersing aids that are available
for use, the selection of the appropriate dispersing aid will
depend on a number of factors, including the capsule shell
chemistry, its morphology, its size and density, as well as the
composition of the aqueous dispersing media, such as its pH and
electrolyte content, all of which will be influenced to a certain
extent by the encapsulation process conditions.
[0013] Indeed, it proved difficult to prepare in a reliable and
reproducible way encapsulated lipophilic components which are
different from perfume, comprising polyurea microcapsules in the
form of aqueous dispersion. Phase separation as well as viscosity
of the dispersion was difficult to control. If the visosity of the
dispersion is too high, often excessive processing forces need to
be employed which in turn can damage the microcapsules.
Furthermore, highly viscous dispersion can be difficult to handle
and can lead to difficulties when incorporating the lipophilic
components into consumer products.
[0014] It is an object of the present invention to provide a
microcapsule composition with improved properties. In particular,
it is an object of the present invention to provide a stable
microcapsule dispersion, wherein the size of the micropasules can
be controlled in a wide range and that are capable releasing an
encapsulated ingredient under controlled conditions. Additionally,
it is very important to provide microcapsule dispersions with a
high stability against phase separation in view of a good storage
stability for their use. Further, it is an object of the present
invention to provide a microcapsule dispersion or the dried
composition for the use in a personal care composition, or in a
composition used for industrial or institutional or hospital
desinfection, or in a material protection composition, or in a
pharmaceutical composition, or in a plant protection composition,
or in home care products.
[0015] All in all, it was an object of the present invention to
prepare microcapsules with tailord properties and to provide these
microcapsules in form of an aqueous dispersion with good phase
separation properties.
[0016] Surprisingly, these objects could be achieved by
microcapsules, wherein the shell of the microcapsules comprises at
least one polyurea and the core comprises at least one lipophilic
components with the proviso that the core does not contain a
fragrance and having a capsule shell weight of 3 to 40%, based on
the total weight of the microcapsules and wherein the microcapsules
have a volume average diameter of 15 to 90 .mu.m.
[0017] It has further surprisingly been found that the ratio of the
shell weight to the volume average diameter of the capsules is a
suitable parameter to select microcapsules having desired release
properties depending on the mechanical stress applied to the
capsules. The mechanical stress applied to the capsules is a
typical parameter for each field of application.
[0018] Moreover, it has further surprisingly been found that
aqueous dispersions of these kind of microcapsules have excellent
phase seperation properties and/or an excellent shell-life in the
presence of hydroxyalkylcellulose as a stabilizing agent.
SUMMARY OF THE INVENTION
[0019] The core of the microcapsules according to the invention
does not contain any fragrance. This holds also for a mixture of
fragrances or formulation of fragrances denoted as "perfume" or
"scent".
[0020] The present invention relates to aqueous dispersions of
microcapsules, wherein the shell of the microcapsules comprises at
least one polyurea and the core comprises one or more lipophilic
components with the proviso that the core does not contain a
fragrance, and having a percentage of the shell weight with
reference to the total weight of the capsules of 3 to 40% and
wherein the microcapsules have a volume average diameter of 15 to
90 .mu.m and the dispersion comprises hydroxyalkylcellulose as a
stabilizing agent.
[0021] The present invention further relates to the use of a
microcapsule dispersion as defined above or of microcapsules
defined above in [0022] a personal care composition or [0023] a
composition used for industrial or institutional or hospital
disinfection or [0024] a material protection composition or [0025]
a pharmaceutical composition or [0026] a plant protection
composition or [0027] home care products.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The volume average particle size is measured by light
scattering measurements using a Malvern 2000S instrument and the
Mie scattering theory. The principle of the Mie theory and how
light scattering can be used to measure capsule size can be found,
for example in H. C. van de Hulst, Light scattering by small
particles. Dover, N.Y., 1981. The primary information provided by
static light scattering is the angular dependence of the light
scattering intensity, which in turn is linked to the size and shape
of the capsules. However, in a standard operation method, the size
of a sphere having a size equivalent to the size of the diffracting
object, whatever the shape of this object is, is calculated by the
Malvern proprietary software provided with the apparatus. In case
of polydisperse samples, the angular dependence of the overall
scattering intensity contains information about the size
distribution in the sample. The output is a histogram representing
the total volume of capsules belonging to a given size class as a
function of the capsule size, whereas an arbitrary number of 50
size classes is typically chosen.
[0029] Experimentally, a few drops of the dispersion containing
about 10% of capsules are added to a circulating stream of degased
water flowing through a scattering cell. The angular distribution
of the scattering intensity is measured and analyzed by Malvern
proprietary software to provide the average size and
size-distribution of the capsules present in the sample. In the
context of the present invention, the percentiles D 10, Dv50 and D
90 are used as characteristics of the particle size distribution,
whereas D 50 corresponds to the median (=average) of the
distribution. In the present invention the term "particle size"
means "volume particle size".
Young's Module (E-Modulus):
[0030] The elastic modulus of microcapsule membranes are studied by
using an Atomic Force Microscope (AFM). The working principle of
atomic force microscopy is based on a scanning probe tip, which
interacts with an underlying surface with low forces. A laser is
focused on the cantilever tip and the reflected laser beam is
recorded by a photodiode. The photodiode detects cantilever
deformations. The AFM probe tip is connected to a piezoelectric
transducer in order to move the tip with respect to the sample.
Hence a topographically image of the sample surface with nanometer
resolution can be obtained. In general the AFM is operated in the
so called Tapping Mode. Thereby the AFM cantilever tip is driven by
an oscillating actuator at a set frequency close to the resonance
frequency of the cantilever and feedback-loop keeps the oscillation
amplitude constant. During each oscillation the tip strikes the
sample surface. Tip-sample interactions can lead to a phase angle
between the external force signal and the cantilever deflection
signal. The so called phase shift provides information about the
material properties of the sample surface. However these data are
not quantitative.
[0031] In order to get quantitative mechanical information of the
microcapsule surface the Peak-Force Quantitative Nano-Mechanics
mode (PF-QNM) is used. Here the AFM cantilever system is
oscillating at a much lower frequency compared to the resonance
frequency of the AFM cantilever. For each oscillation cycle of the
cantilever-tip system a complete Force-Distance curve is recorded
and analyzed. Therefore a full data set including topography,
elasticity, plasticity, and work of adhesion of a given surface can
be studied. A detailed description of this method is given in the
U.S. Pat. No. 8,650,660 B2 "Method and apparatus of using peak
force tapping mode to measure physical properties of a sample".
Nominal Rupture Stress (NRS):
[0032] The burst force of microcapsules is investigated using a
micro-manipulation method. Microcapsules are diluted in distilled
water and cast on a mica plate and dried at room temperature
(24.+-.1.degree. C.). The coated mica plate is then placed on a
positioning stage of the micro-manipulation set-up. The set-up
includes a tip (diameter of the tip apex is in the .mu.m-range),
perpendicular to the positioning stage which is connected to an
actuation-based force transducers allowing simultaneous force and
displacement measurements. An additional optical camera allows
imaging and analyzing the cross-section of individual
microcapsules.
[0033] The measurement of the burst force is done by compressing
individual microcapsules between tip and mica surface and
simultaneously recording the imposed load and tip displacement.
Typically, the microcapsules burst at a critical load at the time
of compression. Images of individual microcapsules are taken before
and after each compression test in order to verify bursting. From
the force-displacement curves the load and microcapsule deformation
at bursting are obtained.
[0034] The load at bursting is measured in mN (Millinewton) and the
microcapsule diameter is measured in .mu.m (Micrometer). For each
type of microcapsule more than 45 individual measurements were
performed. The nominal rupture stress (NRS) is defined as the load
at bursting divided by the projected area of the microcapsule.
Microcapsules
[0035] A first aspect of the invention relates to the aqueous
dispersion of the microcapsules. One important parameter of the
dispersion of microcapsules of the invention is the shell weight of
the capsules in relation to the total weight of the capsules. It is
expressed as percentage of the shell weight with reference to the
total weight of the capsules (=encapsulated lipophilic
component+shell material).
[0036] The percentage of the shell weight with reference to the
total weight of the capsules is of 3% to 40%, particularly 5% to
25%, and more particularly 10% to 20%.
[0037] The shell weight is an important parameter in determining
both the stability of the microcapsules and the performance
characteristics of the dispersion of microcapsules of the present
invention. In particular, the shell weight in relation to the
volume average diameter of the capsules determines the release
characteristics of the encapsulated lipophilic components.
Especially, the stability and performance of the capsules is in an
advantageous range if the ratio of the shell weight, which is
expressed as percentage of the shell weight with reference to the
total weight of the capsules, to the capsule volume average
diameter is .ltoreq.0.7 .mu.m.sup.-1, preferably .ltoreq.0.6
.mu.m.sup.-1, more preferably .ltoreq.0.5 .mu.m.sup.-1, and in
particular .ltoreq.0.2 .mu.m.sup.1.
[0038] It has been found that shell weight to capsule volume ratio
is a more reliable parameter than shell thickness for in-process
control. By manipulating shell weight to capsule volume ratio,
which means simply by controlling the amount of shell-forming
monomers added during the encapsulation process, and the capsule
diameter within the parameters described above, it is possible to
produce microcapsules with at least one encapsulated lipophilic
component having the required release profile for all purposes of
the invention. More particularly, microcapsules, which are
sufficiently mechanically robust when they are subjected to
compression or shear force that does not exceed a critical value
can be obtained. This enables the encapsulated liophilic components
to be incorporated effectively in leave-on products, such as
deodorant sticks, hair conditioners, skin care products including
creams, lotions and shaving products, whilst retaining the
capability of being sheared by frictional contact between material
and material, when in use.
[0039] The microcapsules typically have core/shell ratios (w/w)
from 20:1 to 1:10, preferably from 5:1 to 2:1 and in particular
from 4:1 to 3:1.
[0040] Further, the present invention relates to a microcapsule
dispersion wherein, wherein the viscosity of the dispersion is
preferably .ltoreq.4 Pa s, more preferably in the range from 0.15
to 3 Pa s, when measured on a rheometer, for example a
RheoStress.TM. 1 instrument (ThermoScientific), using rotating
disks at a shear rate of 21 s.sup.-1 at a temperature of 25.degree.
C.
[0041] Preferably, the nominal rupture stress of the microcapsules,
expressed as MPa, is in the range of 0.1 to 2 MPa, particularly 0.2
to 1.5 MPa and more particularly 0.4 to 1 MPa.
[0042] A "stable dispersion" in the sense of the present invention
denotes a dispersion of polyurea microcapsules which, upon visible
inspection, shows no sign of phase separation, such as creaming,
settling, precipitation or coagulation when stored for a period of
two weeks at a temperature of 50.degree. C.
[0043] The term "aqueous dispersion" in the sense of the invention
denotes water and mixtures of water with at least one at least
partly water-miscible organic solvent. Suitable organic solvents
are e.g. C.sub.1-C.sub.4-alkanols. The C.sub.1-C.sub.4-alkanols are
preferably selected from among methanol, ethanol, n-propanol,
isopropanol and n-butanol. Mixtures of at least one
C.sub.1-C.sub.4-alkanol with water preferably comprise from 0.1 to
99.9% by weight, particularly preferably from 0.2 to 50% by weight,
in particular from 0.3 to 10% by weight of at least one
C.sub.1-C.sub.4-alkanol, based on the total weight of the mixture.
In a special embodiment the aqueous dispersion consists of
water.
[0044] Within the context of the present invention, the
microcapsules can be prepared by a process comprising the steps of:
[0045] a) providing a premix (I) comprising at least one protective
colloid different from hydroxyalkylcellulose in an aqueous
solution, [0046] b) providing a premix (II) comprising at least one
polyisocyanate and the at least one lipophilic component, [0047] c)
mixing premix (I) and premix (II) until an emulsion (III) is
formed, [0048] d) adding an aqueous solution (IV) containing at
least one polyfunctional amine to the emulsion formed in step c),
[0049] e) forming a dispersion of microcapsules by heating the
mixture obtained in step d) to a temperature of at least 50.degree.
C. until microcapsules are formed and [0050] f) adding
hydroxyalkylcelluloses as a stabilizing agent to the dispersion
obtained in step e).
[0051] The reaction is a polycondensation between the isocyanate
groups and the amine groups and optional further groups, capable of
reacting with NCO groups, which leads to the formation of polyurea
linkages. The polyfunctional amine may in addition to at least one
primary or secondary amine contain at least one further group,
capable of reacting with NCO groups, e.g. at least one OH group.
Further components, capable of being incorporated into the shell
are in principle all compounds which contain at least one active
hydrogen atom per molecule. Reaction of NCO groups with amine
groups leads to the formation of urea groups. Reaction of NCO
groups with OH groups leads to the formation of urethane groups.
Compounds containing only one active hydrogen atom per molecule
lead to a termination of the polymer chain and can be employed as
regulators. Compounds containing more than two active hydrogen
atoms per molecule lead to the formation of branched polyureas.
[0052] The compounds which contain at least one active hydrogen
atom per molecule are usually employed in a molar excess of active
hydrogen atoms relative to the NCO groups of the polyisocyanate.
The amount of polyfunctional amines which is introduced is usually
in a molar excess, relative to the stoichiometric amount needed to
convert the free isocyanate groups. Suitable polyisocyanates,
polyfunctional amines, optional components that take part in the
polyaddition reaction, lipophilic components, protective colloids,
stabilizing agent and further additives, are mentioned below.
[0053] In a special embodiment, the shell is the reaction product
of at least two different polyisocyanates with at least one
polyfunctional amine and the process is carried out as follows:
[0054] a) providing a premix (I) comprising at least one protective
colloid different from hydroxyalkylcellulose in an aqueous
solution, [0055] b) providing a further premix (II) comprising at
least one lipophilic component and first polyisocyanate (A), [0056]
c) mixing premix (I) and premix (II) until an emulsion is formed
and adding a second polyisocyanate (B) to the emulsion obtained in
step c), [0057] d) adding an aqueous solution (IV) containing at
least one polyfunctional amine to the emulsion formed in step c,
[0058] e) forming a dispersion of microcapsules by heating the
mixture obtained in step d) to a temperature of at least 50.degree.
C. until microcapsules are formed, [0059] f) adding
hydroxyalkylcelluloses as a stabilizing agent to the dispersion
obtained in step e).
[0060] In one preferred embodiment, the process is carried out as
follows: [0061] a) providing a premix (I) comprising at least one
protective colloid different from hydroxyalkylcellulose in an
aqueous solution and adjusting the pH in a range of from 5 to 12,
[0062] b) providing a further premix (II) comprising at least one
lipophilic component and first polyisocyanate (A), [0063] c) mixing
premix (I) and premix (II) until an emulsion is formed and adding a
second polyisocyanate (B) to the emulsion obtained in step c) and
adjusting the pH of the resulting emulsion in a range of from 5 to
10, [0064] d) adding an aqueous solution (IV) containing at least
one polyfunctional amine to the emulsion formed in step c), [0065]
e) forming a dispersion of microcapsules by heating the mixture
obtained in step d) to a temperature of at least 50.degree. C.
until microcapsules are formed [0066] f) adding
hydroxyalkylcelluloses as a stabilizing agent to the dispersion
obtained in step e).
Step a)
[0067] Premix (I) provided in step a) contains an aqueous solvent.
Suitable solvents are water and mixtures of water with at least one
water-miscible organic solvent. Suitable water-miscible organic
solvent are mentioned above. Preferably, the solvent is essentially
water.
[0068] The aqueous solution provided in step a) comprises at least
one protective colloid. The protective colloid provided in step a)
is preferably different from hydroxyalkylcellulose.
[0069] During the reaction between the polyisocyanates and the
polyfunctional amines, a protective colloid may be present.
Protective colloids are polymer systems which, in suspensions or
dispersions, prevent a clumping together (agglomeration,
coagulation, flocculation) of the emulsified, suspended or
dispersed components. During solvation, protective colloids bind
large amounts of water and in aqueous solutions produce high
viscosities depending on the concentration. Within the context of
the process described herein, the protective colloid may also have
emulsifying properties. The aqueous protective colloid solution is
likewise preferably prepared with stirring.
[0070] Preferably, premix (I) comprises at least one protective
colloid selected from polyvinylpyrrolidones, polyvinyl alcohols,
maleic-vinyl copolymers, sodium lignosulfonates, maleic
anhydride/styrene copolymers, ethylene/maleic anhydride copolymers,
copolymers of ethylene oxide, propylene oxide and ethylenediamine,
fatty acid esters of polyethoxylated sorbitol, sodium
dodecylsulfate and mixtures thereof. More preferably, premix (I)
comprises at least one protective colloid selected from
polyvinylpyrrolidones, polyvinyl alcohols and mixtures thereof.
Polyvinylpyrrolidones are particularly preferred.
[0071] Standard commercial polyvinylpyrrolidones have molar masses
in the range from ca. 2500-750000 g/mol which are characterized
with K values and have--depending on the K value--glass transition
temperatures from 130 to 175.degree. C. They are supplied as white,
hygroscopic powders or as aqueous solution.
[0072] The polyvinylpyrrolidones used in premix (I) preferably have
a K value (determined at 25.degree. C. in a 1% by weight aqueous or
ethanolic solution) of at least 10, particularly preferably of at
least 20, more preferably of at least 80. Determination of the K
value is described in H. Fikentscher "Systematik der Cellulosen auf
Grund ihrer Viskositat in Losung", Cellulose-Chemie 13 (1932),
58-64 and 71-74, and Encyclopedia of Chemical Technology, Vol. 21,
2nd edition, 427-428 (1970).
[0073] Suitable commercially available polyvinylpyrrolidones are
the Kollidon trademarks from BASF SE. Preferred
polyvinylpyrrolidones useful in the practice of the present
invention are available in three grades: Kollidon.RTM. 25 (BASF
Corporation), Kollidon.RTM. 90 (BASF Corporation), and
Kollidon.RTM. CI-M (BASF Corporation). Kollidon.RTM. 25 has a
weight average molecular weight of 28000-34000. Kollidon.RTM. 90
has a molecular weight average of 1000000-1500000.
[0074] Further commercially available polyvinylpyrrolidones are
Kollidon 12 which has a weight average molecular weight of
2000-3000, Kollidon 17 which has a weight average molecular weight
of 7000-11000 and Kollidon 30 which has a weight average molecular
weight of 44000-54000.
[0075] Particular protective colloids include polyvinyl alcohol
copolymers having a degree of hydrolysis in the range of 85 to
99.9%. As used herein, the term "polyvinyl alcohol copolymer" means
a polymer of vinyl alcohol/vinyl acetate with comonomers.
[0076] It is known that polyvinyl alcohol is produced by hydrolysis
(deacetylation) of polyvinylacetate, whereby ester groups of
polyvinyl acetate are hydrolysed into hydroxyl groups, thus forming
polyvinyl alcohol.
[0077] The degree of hydrolysis reflects the percentage of groups
that are converted by hydrolysis. The term "polyvinyl alcohol",
qualified by a degree of hydrolysis, means therefore, a vinyl
polymer containing both ester and hydroxyl groups.
[0078] In a particular embodiment of the invention, copolymers of
polyvinyl alcohol with a degree of hydrolysis in the range of 85 to
99.9%, more particularly 85 to 95% may be used as protective
colloids.
[0079] The degree of hydrolysis can be determined by techniques
well known in the art, for example, according to DIN 53401.
[0080] The polyvinyl alcohol copolymers contain addition
comonomers, that is, comonomers that are polymerized with a vinyl
ester in a first step, followed by hydrolysis of the ester groups
to form the copolymer of polyvinyl alcohol in a second step.
Copolymers may be formed by radical polymerization of vinyl acetate
and comonomers in a manner known per se.
[0081] Polyvinyl alcohol copolymers may contain unsaturated
hydrocarbons as comonomers. These hydrocarbons may be modified with
charged or non-charged functional groups. Particular comonomers
include, but are not limited to: [0082] unsaturated hydrocarbons
with 2 or 3 carbon atoms and no functional groups, e.g. ethylene,
[0083] unsaturated hydrocarbons having 2 to 6 carbon atoms and
non-charged functional groups, such as hydroxyl groups, e.g.
buten-1,4-diol, [0084] unsaturated hydrocarbons having anionic
groups, such as carboxyl, and/or sulphonic acid groups, [0085]
unsaturated hydrocarbons having cationic groups, such as quaternary
ammonium groups.
[0086] Particular copolymers of polyvinyl alcohol include those
having a degree of hydrolysis of 85 to 99.9%, and more particularly
85 to 95%; and which contain: 0.1 to 30 mol % of comonomers
containing anionic groups as mentioned above; or [0087] 0.1 to 30
mol % of comonomers containing cationic groups as mentioned above
or [0088] 0.1 to 30 mol % of comonomers with unsaturated
hydrocarbons having 2 to 6 carbon atoms [0089] and non-charged
functional groups, especially two hydroxyl groups, wherein mol % is
based on the vinyl acetate/comonomer polymerization mixture.
[0090] Suitable copolymers of polyvinyl alcohol and comonomers
having 1,2 diol structures are described in EP 2 426 172 and EP 2
648 211 which are herein incorporated by reference.
[0091] Particularly preferred polyvinyl alcohols are the G-polymer
type available from Nichigo.
[0092] The following protective colloids are particularly useful in
the preparation of polyurea capsule compositions of the present
invention: [0093] Anionic polyvinyl alcohol copolymers with a
degree of hydrolysis of greater than 80%, preferably 85.0% to 995%,
and a viscosity of 2 mPas to 70 mPas (DP 100 to 6000), for example
K-polymer KL-318 from Kuraray (viscosity 20 to 30 mPas, hydrolysis
85.0 to 90.0%); Gohsenal T-350 from Nippon Gohesi (viscosity 27 to
33 mPas, hydrolysis 93.0 to 95.0%); Gohseran L-3266 from Nippon
Gohsei (viscosity 2.3 to 2.7 mPas, hydrolysis 86.5 to 89.0%);
[0094] Non-charged polyvinyl alcohol copolymers with a degree of
hydrolysis of greater that 80%, preferably 85.0 to 99.5%, and a
viscosity of 2 mPas to 70 mPas (DP 100-6000), for example G-polymer
OKS-8041 from Nippon Gohsei (viscosity 2.8 to 3.3 mPas, hydrolysis
88.0 to 90.0%), G-polymer AZF-8035 from Nippon Gohsei (viscosity
2.8 to 3.3 mPas, hydrolysis 98.5 to 99.5%); and [0095] Cationic
polyvinyl alcohol copolymers with a degree of hydrolysis of greater
than 80%, and more particularly 85.0 to 99.5%, and a viscosity of 2
mPas to 70 mPas (DP 100 to 6000), for example Gohsefimer K-210 from
Nippon Gohsei (viscosity 18.0 to 22.0 mPas, hydrolysis 85.5 to
88.0%).
[0096] The protective colloid can be, but does not have to be, a
constituent of the capsule shell.
[0097] The protective colloid may be, but does not have to be, a
constituent of the capsule shell with amounts from 0.1 to at most
15% by weight, but preferably in the range from 1 to 5% by weight
and in particular from 1.5 to 3% by weight, based on the weight of
the capsules, being possible here.
[0098] Combinations of two or more different protective colloids
may also be employed in the present invention.
[0099] In a further preferred embodiment, the protective colloid
employed in step a) comprises or consists of at least one
polyvinylpyrrolidone.
[0100] Premix (I) may also contain at least one emulsifier.
Emulsifiers include nonionic, cationic, anionic and zwitterionic
surfactants.
[0101] Suitable nonionic surfactants are selected from the group
consisting of products of the addition of 2 to 30 mol ethylene
oxide and/or 0 to 5 mol propylene oxide onto linear C.sub.6-22
fatty alcohols, onto C.sub.12-22 fatty acids, onto alkyl phenols
containing 8 to 15 carbon atoms in the alkyl group and onto
alkylamines containing 8 to 22 carbon atoms in the alkyl group;
alkyl oligoglycosides containing 8 to 22 carbon atoms in the alkyl
group and ethoxylated analogs thereof; addition products of 1 to 15
mol ethylene oxide onto castor oil and/or hydrogenated castor oil;
addition products of 15 to 60 mol ethylene oxide onto castor oil
and/or hydrogenated castor oil; partial esters of glycerol and/or
sorbitan with unsaturated, linear or saturated branched fatty acids
containing 12 to 22 carbon atoms and/or hydroxycarboxylic acids
containing 3 to 18 carbon atoms and addition products thereof onto
1 to 30 mol ethylene oxide; partial esters of polyglycerol (average
degree of self-condensation 2 to 8), polyethylene glycol (molecular
weight 400 to 5,000), trimethylolpropane, pentaerythritol, sugar
alcohols (for example sorbitol), alkyl glucosides (for example
methyl glucoside, butyl glucoside, lauryl glucoside) and
polyglucosides (for example cellulose) with saturated and/or
unsaturated, linear or branched fatty acids containing 12 to 22
carbon atoms and/or hydroxycarboxylic acids containing 3 to 18
carbon atoms and addition products thereof onto 1 to 30 mol
ethylene oxide; mixed esters of pentaerythritol, fatty acids,
citric acid and fatty alcohol and/or mixed esters of fatty acids
containing 6 to 22 carbon atoms, methyl glucose and polyols,
preferably glycerol or polyglycerol, mono-, di- and trialkyl
phosphates and mono-, di- and/or tri-PEG-alkyl phosphates and salts
thereof, wool wax alcohols, polysiloxane/polyalkyl/polyether
copolymers and corresponding derivatives, block copolymers, for
example Polyethyleneglycol-30 Dipolyhydroxystearate; polymer
emulsifiers, for example Pemulen types (TR-1, TR-2) of Goodrich;
polyalkylene glycols and glycerol carbonate and ethylene oxide
addition products.
Step b
[0102] Premix (II) provided in step b) comprises at least one
polyisocyanate providing and at least one lipophilic component.
[0103] Premix (II) is generally in liquid form. Preferably, premix
(II) contains no or only a minor amount of solid components. In the
sense of the invention a minor amount means that the amount of
solid components is at the most 5% by weight, preferably at the
most 1% by weight, more preferably at the most 0.1% by weight,
based on the total weight of premix (II). In particular, premix
(II) contains no solid components.
[0104] Premix (II) optionally contains at least one organic
solvent. An organic solvent is particularly used if the mixture of
the employed polyisocyanates and the employed lipophilic components
is not liquid under the conditions of process step b).
[0105] Lipophilic components are in general components which have
only limited solubility in water. This includes hydrophobic
components that are liquid under the encapsulation conditions and
mixtures of hydrophobic components, wherein the mixture is liquid
under the encapsulation conditions. Said mixtures may contain at
least one hydrophobic component that is solid, but is solubilized
in at least one liquid component.
[0106] Premix (II) does not contain a fragrance as hydrophobic
component. In the sense of the invention the term perfume or any
fragrances as such materials are excluded.
[0107] Suitable lipophilic components are mentioned in detail
below. In the sense of the invention, the term "lipophilic
component" is understood in a broad sense. It encompasses a single
lipophilic component, a mixture comprising at least two lipophilic
components and a solution of at least one lipophilic solid compound
in a liquid lipophilic compound.
[0108] The lipophilic components used according to the invention
have only a limited solubility in water. The solubility of the
lipophilic components in water at 20.degree. C. and 1013 mbar is
preferably .ltoreq.10 mg/mL, more preferably .ltoreq.5 mg/mL, in
particular .ltoreq.3 mg/m L.
[0109] In a special embodiment of the invention, the microcapsules
contain substantially no solvent in the core. According to the
process of the invention, it is possible to prepare a microcapsule
composition, wherein the encapsulated cores are composed entirely
of lipophilic components and no solvents. Solvent-free encapsulated
lipophilic components may be employed, in particular, when the
lipophilic components making up the core material are liquid under
the conditions used for the preparation of the microcapsules.
[0110] Preferably, at least 60% by weight, more preferably at least
70% by weight, in particular at least 80% by weight and especially
at least 90% by weight of lipophilic components, based on the total
weight of the lipophilic components, have a solubility in water at
20.degree. C. and 1013 mbar of 10 mg/mL, particularly 5 mg/mL, and
more particularly 3 mg/mL.
[0111] The microcapsules contain one or more lipophilic components.
Preferably, the amount of the lipophilic components is in a range
of from 5 to 97% by weight, more preferably 10 to 95% by weight, in
particular 25 to 93% by weight, based on the total weight of the
microcapsules. In a special embodiment, the amount of the
lipophilic components is in a range of from 70 to 98% by weight,
based on the total weight of the microcapsules.
[0112] Preferably, the amount of the lipophilic components is in a
range of from 5 to 65% by weight, more preferably 10 to 50% by
weight, in particular 20 to 40% by weight, especially 25 to 35% by
weight, based on the total weight of the microcapsule
composition.
[0113] Advantageously, a large amount of lipophilic components can
be encapsulated in the microcapsules of the invention despite the
relatively low shell weight. Preferably, the ratio of the total
weight of the lipophilic components to total weight of the shell
material is in a range of from 60% to 95% by weight, more
preferably 75% to 80% by weight, and more particularly 80% to 88%
by weight.
[0114] The core-shell weight ratio may be obtained by weighing an
amount of capsules that have been previously washed with water and
separated by filtration. The core is then extracted by solvent
extraction techniques to give a core weight. The shell weight is
obtained from simple mass balance taking into account the initial
amount of encapsulating materials in weight %.
[0115] Lipophilic components that are used can be various organic
substances. In particular, the lipophilic component is selected
from active ingredients and auxiliaries for cosmetics (e.g. hair
and skin cosmetics), pharmaceuticals, hygiene compositions,
detergents, cleaning agents, textile treatment compositions, etc.,
compositions used for industrial or institutional or hospital
applications, material protection compositions or plant protection
compositions. Especially, the lipophilic component is selected from
active substances and additives for personal care compositions,
home care compositions, compositions used for industrial or
institutional or hospital applications, material protection
compositions, pharmaceutical compositions or plant protection
composition.
[0116] Active ingredients are substances which generally develop an
effect even at low concentration, e.g. a cosmetic effect on skin
and/or hair, a pharmacological effect in an organism, a plant
protecting effect, a cleaning and/or disinfecting effect, a
modification of a textile substance, e.g. a crease-free finishing,
and effect substances which impart a certain property to living
things or inanimate substrates, for example colors for make-up,
mascara, etc.
[0117] Preferably, the lipophilic component is selected from oil
bodies, UV-filters, organic compounds, biocides, dyes, emollients,
vitamins, cosmetically active ingredients, pharmaceutically active
ingredients, cosmetically and pharmaceutically acceptable
auxiliaries, detergents or mixtures thereof.
[0118] A first class of lipophilic components that can be
encapsulated are oil bodies.
[0119] Preferably, the lipophilic components comprise at least one
oil body capable to dissolve the polyisocyanates employed in step
b). More preferably, these oil body are capable to dissolve the
polyisocyanates without extraneous solvents and/or auxiliaries.
Should an oil body not ensure adequate solubility of the
polyisocyanates, there is the option of overcoming this
disadvantage by using suitable solubility promoters.
[0120] The term oil body in the sense of the invention means
vegetable oils, modified vegetable oils, synthetic (tri)glycerides,
fatty acid alkyl esters, fatty acid alkyl esters based on said
C.sub.6-C.sub.22 fatty acids, mineral oils, silicone oils,
hydrocarbons, saturated or unsaturated C.sub.6-C.sub.30-fatty
acids, aromatic compounds, waxes, polymers, Guerbet alcohols based
on fatty alcohols, esters of linear C.sub.6-C.sub.22-fatty acids
and mixtures thereof.
[0121] Suitable vegetable oils are rape seed oil, sunflower oil,
soy oil, olive oil and mixtures thereof.
[0122] Modified vegetable oils are alkoxylated sunflower or soy oil
and mixtures thereof.
[0123] Synthetic (tri)glycerides are technical mixtures of mono, di
and triglycerides of C.sub.6-C.sub.22 fatty acids and mixtures
thereof. Preferred are caprylic/capric triglyceride. Preferred
commercially available caprylic/capric triglyceride are sold by
BASF SE under the trademark Myritol.RTM..
[0124] Suitable fatty acid alkyl esters are selected from methyl or
ethyl esters of vegetable oils. Preferred commercially available
fatty acid alkyl esters sold by BASF SE under the trademarks
Agnique.RTM. ME 18 RD-F, Agnique.RTM. ME 18 SD-F, Agnique.RTM. ME
12C-F, Agnique.RTM..
[0125] Suitable silicone oils are cyclomethicones or silicon
methicone types;
[0126] Suitable aliphatic hydrocarbon compounds are straight-chain
alkanes or paraffinic hydrocarbons, branched-chain alkanes,
unsaturated hydrocarbons, halogenated hydrocarbons, and alicyclic
hydrocarbons, such as hexane, cyclohexane, decane,
chloroparaffines, fluorinated hydrocarbons, saturated or
unsaturated C.sub.1-C.sub.40-hadrocarbons which are branched or
linear, e. g. n-tetradecane, n-pentadecane, n-hexadecane,
n-heptadecane, n-octadecane, n-nonadecane, n-eicosane,
n-heneicosane, n-docosane, n-tricosane, n-tetracosane,
n-pentacosane, n-hexacosane, n-heptacosane, n-octacosane, also
cyclic hydrocarbons, e.g. cyclohexane, cyclodecane; halogenated
hydrocarbons, such as chloroparaffines, bromooctadecane,
bromopentadecane, bromononadecane, bromeicosane, bromodocosane;
[0127] Suitable aromatic compounds are benzene, naphthalene,
alkylnaphthalenes, biphenyl, o- or n-terphenyl, xylene, toluene
dodecylbenzene, C.sub.1-C.sub.40-alkyl-substituted aromatic
hydrocarbons, such as dodecylbenzene, tetradecylbenzene,
hexadecylbenzene, hexylnaphtalene or decylnaphthalene;
[0128] Suitable saturated or unsaturated C.sub.6-C.sub.30-fatty
acids are lauric acid, stearic acid, oleic acid or behenic acid,
preferably eutectic mixtures of decanonic acid with for example
myristic, palmitic or lauric acid;
[0129] Suitable waxes are natural and synthetic waxes, such as
montan waxes, montan ester waxes, carnauba waxes, polyethylene wax,
oxidized waxes, polyvinyl ether wax, ethylene-vinyl acetate wax or
hard waxes obtained from Fischer-Tropsch process;
[0130] Suitable polymers are polyethylene, polypropylene,
polypropylene glycol, polytetramethylene glycol, polypropylene
malonate, polyneopentyl glycol sebacate, polypentane glutarate,
polyvinyl myristate, polyvinyl stearate, polyvinyl laurate,
polyhexadecyl methacrylate, polyoctadecyl methacrylate, polyesters
produced by polycondensation of glycols (or their derivatives) with
diacids (or their derivatives), and copolymers, such as
polyacrylate or poly(meth)acrylate with alkyl hydrocarbon side
chain or with polyethylene glycol side chain and copolymers
including polyethylene, polypropylene, polypropylene glycol, or
polytetramethylene glycol;
[0131] Suitable Guerbet alcohols based on fatty alcohols having 6
to 18, preferably 8 to 10, carbon atoms, esters of linear
C.sub.6-C.sub.22-fatty acids with linear or branched
C.sub.6-C.sub.22-fatty alcohols or esters of branched
C.sub.6-C.sub.13-carboxylic acids with linear or branched
C.sub.6-C.sub.22-fatty alcohols, such as, for example, myristyl
myristate, myristyl palmitate, myristyl stearate, myristyl
isostearate, myristyl oleate, myristyl behenate, myristyl erucate,
cetyl myristate, cetyl palmitate, cetyl stearate, cetyl
isostearate, cetyl oleate, cetyl behenate, cetyl erucate, stearyl
myristate, stearyl palmitate, stearyl stearate, stearyl
isostearate, stearyl oleate, stearyl behenate, stearyl erucate,
isostearyl myristate, isostearyl palmitate, isostearyl stearate,
isostearyl isostearate, isostearyl oleate, isostearyl behenate,
isostearyl oleate, oleyl myristate, oleyl palmitate, oleyl
stearate, oleyl isostearate, oleyl oleate, oleyl behenate, oleyl
erucate, behenyl myristate, behenyl palmitate, behenyl stearate,
behenyl isostearate, behenyl oleate, behenyl behenate, behenyl
erucate, erucyl myristate, erucyl palmitate, erucyl stearate,
erucyl isostearate, erucyl oleate, erucyl behenate and erucyl
erucate. Also suitable are esters of linear C.sub.6-C.sub.22-fatty
acids with branched alcohols, in particular 2-ethylhexanol, esters
of C.sub.18-C.sub.38-alkylhydroxy carboxylic acids with linear or
branched C.sub.6-C.sub.22-fatty alcohols, in particular Dioctyl
Malate, esters of linear and/or branched fatty acids with
polyhydric alcohols (such as, for example, propylene glycol,
dimerdiol or trimertriol) and/or Guerbet alcohols, triglycerides
based on C.sub.6-C.sub.10-fatty acids, liquid
mono-/di-/triglyceride mixtures based on C.sub.6-C.sub.18-fatty
acids, esters of C.sub.6-C.sub.22-fatty alcohols and/or Guerbet
alcohols with aromatic carboxylic acids, in particular benzoic
acid, esters of C.sub.2-C.sub.12-dicarboxylic acids with linear or
branched alcohols having 1 to 22 carbon atoms or polyols having 2
to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils,
branched primary alcohols, substituted cyclohexanes, linear and
branched C.sub.e-C.sub.22-fatty alcohol carbonates, such as, for
example, dicaprylyl carbonate (Cetiol.RTM. CC), Guerbet carbonates,
based on fatty alcohols having 6 to 18, preferably 8 to 10, carbon
atoms, esters of benzoic acid with linear and/or branched
C.sub.6-C.sub.22-alcohols, linear or branched, symmetrical or
asymmetrical dialkyl ethers having 6 to 22 carbon atoms per alkyl
group, such as, for example, dicaprylyl ether, ring-opening
products of epoxidized fatty acid esters with polyols, silicone
oils (cyclomethicones, silicone methicone grades, etc.), aliphatic
or naphthenic hydrocarbons, such as, for example, squalane,
squalene or dialkylcyclohexanes, and/or mineral oils; and mixtures
of these substances.
[0132] Preferred oils are cosmetical acceptable oils. Preferred
oils are caprylic/capric triglyceride, myristyl myristate, cetyl
oleate.
[0133] Preferred commercial avalible caprylic/capric triglyceride
are sold by BSAF SE under the trademark Myritol.RTM. 318.
[0134] Within the context of the present invention, preferred oil
bodies are Guerbet alcohols based on fatty alcohols having 6 to 18,
preferably 8 to 10, carbon atoms, esters of linear
C.sub.6-C.sub.22-fatty acids with linear or branched
C.sub.6-C.sub.22-fatty alcohols or esters of branched
C.sub.6-C.sub.13-carboxylic acids with linear or branched
C.sub.6-C.sub.22-fatty alcohols, such as e.g. myristyl myristate,
myristyl palmitate, myristyl stearate, myristyl isostearate,
myristyl oleate, myristyl behenate, myristyl erucate, cetyl
myristate, cetyl palmitate, cetyl stearate, cetyl isostearate,
cetyl oleate, cetyl behenate, cetyl erucate, stearyl myristate,
stearyl palmitate, stearyl stearate, stearyl isostearate, stearyl
oleate, stearyl behenate, stearyl erucate, isostearyl myristate,
isostearyl palmitate, isostearyl stearate, isostearyl isostearate,
isostearyl oleate, isostearyl behenate, isostearyl oleate, oleyl
myristate, oleyl palmitate, oleyl stearate, oleyl isostearate,
oleyl oleate, oleyl behenate, oleyl erucate, behenyl myristate,
behenyl palmitate, behenyl stearate, behenyl isostearate, behenyl
oleate, behenyl behenate, behenyl erucate, erucyl myristate, erucyl
palmitate, erucyl stearate, erucyl isostearate, erucyl oleate,
erucyl behenate and erucyl erucate.
[0135] Also preferred oil bodies are esters of linear
C.sub.6-C.sub.22-fatty acids with branched alcohols, in particular
2-ethylhexanol, esters of C.sub.18-C.sub.38-alkylhydroxycarboxylic
acids with linear or branched C.sub.6-C.sub.22-fatty alcohols,
linear or branched C.sub.6-C.sub.22-fatty alcohols, in particular
dioctyl malates, esters of linear and/or branched fatty acids with
polyhydric alcohols (such as e.g. propylene glycol, dimerdiol or
trimertriol) and/or Guerbet alcohols, triglycerides based on
C.sub.6-C.sub.10-fatty acids, liquid mono-/di-/triglyceride
mixtures based on C.sub.6-C.sub.18-fatty acids, esters of
C.sub.6-C.sub.22-fatty alcohols and/or Guerbet alcohols with
aromatic carboxylic acids, in particular benzoic acid, esters of
C.sub.2-C.sub.12-dicarboxylic acids with linear or branched
alcohols having 1 to 22 carbon atoms or polyols having 2 to 10
carbon atoms and 2 to 6 hydroxyl groups, vegetable oils, branched
primary alcohols, substituted cyclohexanes, linear and branched
C.sub.6-C.sub.22-fatty alcohol carbonates, such as e.g. dicaprylyl
carbonate (Cetiol.TM. CC), Guerbet carbonates based on fatty
alcohols having 6 to 18, preferably 8 to 10, carbon atoms, esters
of benzoic acid with linear and/or branched
C.sub.6-C.sub.22-alcohols (e.g. Finsolv.TM. TN), linear or
branched, symmetrical or asymmetrical dialkyl ethers having 6 to 22
carbon atoms per alkyl group, such as e.g. dicaprylyl ether
(Cetiol.TM. OE), ring-opening products of epoxidized fatty acid
esters with polyols, silicone oils (cyclomethicones, silicon
methicone types etc.) and/or aliphatic or naphthenic hydrocarbons,
such as e.g. squalane, squalene or dialkylcyclohexanes.
[0136] A further class of lipophilic components that can be
encapsulated are UV filters. Preferably, the lipophilic components
comprise at least one UV filters capable to dissolve the
polyisocyanates employed in step b). More preferably, these
UV-filters are capable to dissolve the polyisocyanates without
extraneous solvents and/or auxiliaries. Should an UV filter not
ensure adequate solubility of the polyisocyanates, there is the
option of overcoming this disadvantage by using suitable solubility
promoters.
[0137] Typical lipophilic UV filters are UV-A filters, UV-B filters
or broad-spectrum UV A/B filters are, for example,
3-benzylidenecamphor or 3-benzylidenenorcamphor and derivatives
thereof, e.g. 3-(4-methylbenzylidene)-camphor,
3-(4'-trimethylammonium)benzylidenebornan-2-one methylsulfate
(Mexoryl SO),
3,3'-(1,4-phenylenedimethine)bis(7,7-dimethyl-2-oxobicycle-[2.2.1]he-
ptane-1-methanesulfonic acid) and salts (Mexoryl SX),
3-(4'-sulfo)benzylidenebornan-2-one and salts (Mexoryl SL), polymer
of N-{(2 and 4)[2-oxoborn-3-ylidene)methyl}benzyl]acrylamide
(Mexoryl SW),
2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-(1,3,3,3-tetramethyl-1-(t-
rimethylsilyloxy) disiloxanyl)propyl)phenol (Mexoryl SL),
4-aminobenzoic acid derivatives, preferably 2-ethylhexyl
4-(dimethylamino)benzoate, 2-octyl 4-(dimethylamino)benzoate and
amyl 4-(dimethylamino) benzoate; esters of cinnamic acid,
preferably 2-ethylhexyl 4-methoxycinnamate, propyl
4-methoxycinnamate, isoamyl 4-m ethoxycinnamate, 2-ethylhexyl
2-cyano-3,3-phenylcinnamate (octocrylene); esters of salicylic
acid, preferably 2-ethylhexyl salicylate, 4-isopropylbenzyl
salicylate, homomenthyl salicylate; derivatives of benzophenone,
preferably 2-hydroxy-4-methoxybenzophenone,
2-hydroxy-4-methoxy-4'-methylbenzophenone,
2,2'-dihydroxy-4-methoxybenzophenone; esters of benzalmalonic acid,
preferably di-2-ethylhexyl 4-methoxy-benzmalonate; triazine
derivatives, such as e.g.
2,4,6-trianilino(p-carbo-2'-ethyl-t-hexyloxy)-1,3,5-triazine and
2,4,6-tris[p-(2-ethylhexyloxycarbonyl)anilino]-1,3,5-triazine
(Uvinul T 150) or bis(2-ethylhexyl)
4,4'-[(6-[4-((1,1-dimethylethyl)aminocarbonyl)phenylamino]-1,3,5-triazine-
-2,4-diyl)diimino]bisbenzoate (Uvasorb.RTM. HEB);
2,2-(methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)ph-
enol (Tinosorb.RTM. M);
2,4-bis[4-(2-ethylhexyloxy)-2-hydroxy-phenyl]-6-(4-methoxyphenyl)-1,3,5-t-
riazine (Tinosorb.RTM. S); propane-1,3-diones, such as e.g.
1-(4-tert-butyl-phenyl)-3-(4'-methoxyphenyl)propane-1,3-dione;
ketotricyclo(5.2.1.0)decane derivatives, di-methicodiethyl
benzalmalonate (Parsol.RTM. SLX).
[0138] A further class of lipophilic components that can be
encapsulated are biocides.
[0139] Preferably, the lipophilic components comprise at least one
biocide capable to dissolve the polyisocyanates employed in step
b). More preferably, these biocides are capable to dissolve the
polyisocyanates without extraneous solvents and/or auxiliaries.
Should an biocide not ensure adequate solubility of the
polyisocyanates, there is the option of overcoming this
disadvantage by using suitable solubility promoters.
[0140] A biocide is a chemical substances capable of killing
different forms of living organisms used in fields, such as
medicine, agriculture, forestry, and mosquito control. Usually,
biocides are divided into two sub-groups: [0141] pesticides which
includes fungicides, herbicides, insecticides, algicides,
moluscicides, miticides and rodenticides, and [0142] antimicrobials
which includes germicides, antibiotics, antibacterials, antivirals,
antifungals, antiprotozoals and antiparasites.
[0143] Biocides can also be added to other materials (typically
liquids) to protect the material from biological infestation and
growth. For example, certain types of quaternary ammonium compounds
(quats) can be added to pool water or industrial water systems to
act as an algicide, protecting the water from infestation and
growth of algae.
[0144] Pesticides:
[0145] The U.S. Environmental Protection Agency (EPA) defines a
pesticide as "any substance or mixture of substances intended for
preventing, destroying, repelling, or mitigating any pest". A
pesticide may be a chemical substance or biological agent (such as
a virus or bacteria) used against pests, including insects, plant
pathogens, weeds, mollusks, birds, mammals, fish, nematodes
(roundworms) and microbes that compete with humans for food,
destroy property, spread disease or are a nuisance. In the
following examples, pesticides suitable for the agrochemical
compositions according to the present invention are given:
[0146] Fungicides:
[0147] A fungicide is one of three main methods of pest
control--the chemical control of fungi in this case. Fungicides are
chemical compounds used to prevent the spread of fungi in gardens
and crops. Fungicides are also used to fight fungal infections.
Fungicides can either be contact or systemic. A contact fungicide
kills fungi when sprayed on its surface. A systemic fungicide has
to be absorbed by the fungus before the fungus dies. Examples for
suitable fungicides, according to the present invention, encompass
the following species: (3-ethoxypropyl)mercury bromide,
2-methoxyethylmercury chloride, 2-phenylphenol, 8-hydroxyquinoline
sulfate, 8-phenylmercurioxyquinoline, acibenzolar, acylamino acid
fungicides, acypetacs, aldimorph, aliphatic nitrogen fungicides,
allyl alcohol, amide fungicides, ampropylfos, anilazine, anilide
fungicides, antibiotic fungicides, aromatic fungicides,
aureofungin, azaconazole, azithiram, azoxystrobin, barium
polysulfide, benalaxy,I benalaxyl-M, benodanil, benomyl, benquinox,
bentaluron, benthiavalicarb, benzalkonium chloride, benzamacril,
benzamide fungicides, benzamorf, benzanilide fungicides,
benzimidazole fungicides, benzimidazole precursor fungicides,
benzimidazolylcarbamate fungicides, benzohydroxamic acid,
benzothiazole fungicides, bethoxazin, binapacryl, biphenyl,
bitertanol, bithionol, blasticidin-S, Bordeaux mixture, boscalid,
bridged diphenyl fungicides, bromuconazole, bupirimate, Burgundy
mixture, buthiobate, butylamine, calcium polysulfide, captafol,
captan, carbamate fungicides, carbamorph, carbanilate fungicides,
carbendazim, carboxin, carpropamid, carvone, Cheshunt mixture,
chinomethionat, chlobenthiazone, chloraniformethan, chloranil,
chlorfenazole, chlorodinitronaphthalene, chloroneb, chloropicrin,
chlorothalonil, chlorquinox, chlozolinate, ciclopirox, climbazole,
clotrimazole, conazole fungicides, conazole fungicides
(imidazoles), conazole fungicides (triazoles), copper(II) acetate,
copper(II) carbonate, basic, copper fungicides, copper hydroxide,
copper naphthenate, copper oleate, copper oxychloride, copper(II)
sulfate, copper sulfate, basic, copper zinc chromate, cresol,
cufraneb, cuprobam, cuprous oxide, cyazofamid, cyclafuramid, cyclic
dithiocarbamate fungicides, cycloheximide, cyflufenamid, cymoxanil,
cypendazole, cyproconazole, cyprodinil, dazomet, DBCP, debacarb,
decafentin, dehydroacetic acid, dicarboximide fungicides,
dichlofluanid, dichlone, dichlorophen, dichlorophenyl,
dicarboximide fungicides, dichlozoline, diclobutrazol, diclocymet,
diclomezine, dicloran, diethofencarb, diethyl pyrocarbonate,
difenoconazole, diflumetorim, dimethirimol, dimethomorph,
dimoxystrobin, diniconazole, dinitrophenol fungicides, dinobuton,
dinocap, dinocton, dinopenton, dinosulfon, dinoterbon,
diphenylamine, dipyrithione, disulfiram, ditalimfos, dithianon,
dithiocarbamate fungicides, DNOC, dodemorph, dodicin, dodine,
DONATODINE, drazoxolon, edifenphos, epoxiconazole, etaconazole,
etem, ethaboxam, ethirimol, ethoxyquin, ethylmercury
2,3-dihydroxypropyl mercaptide, ethylmercury acetate, ethylmercury
bromide, ethylmercury chloride, ethylmercury phosphate,
etridiazole, famoxadone, fenamidone, fenaminosulf, fenapanil,
fenarimol, fenbuconazole, fenfuram, fenhexamid, fenitropan,
fenoxanil, fenpiclonil, fenpropidin, fenpropimorph, fentin, ferbam,
ferimzone, fluazinam, fludioxonil, flumetover, flumorph,
fluopicolide, fluoroimide, fluotrimazole, fluoxastrobin,
fluquinconazole, flusilazole, flusulfamide, flutolanil, flutriafol,
folpet, formaldehyde, fosetyl, fuberidazole, furalaxyl, furametpyr,
furamide fungicides, furanilide fungicides, furcarbanil,
furconazole, furconazole-cis, furfural, furmecyclox, furophanate,
glyodin, griseofulvin, guazatine, halacrinate, hexachlorobenzene,
hexachlorobutadiene, hexachlorophene, hexaconazole, hexylthiofos,
hydrargaphen, hymexazol, imazalil, imibenconazole, imidazole
fungicides, iminoctadine, inorganic fungicides, inorganic mercury
fungicides, iodomethane, ipconazole, iprobenfos, iprodione,
iprovalicarb, isoprothiolane, isovaledione, kasugamycin,
kresoxim-methyl, lime sulphur, mancopper, mancozeb, maneb, mebenil,
mecarbinzid, mepanipyrim, mepronil, mercuric chloride, mercuric
oxide, mercurous chloride, mercury fungicides, metalaxyl,
metalaxyl-M, metam, metazoxolon, metconazole, methasulfocarb,
methfuroxam, methyl bromide, methyl isothiocyanate, methylmercury
benzoate, methylmercury dicyandiamide, methylmercury
pentachlorophenoxide, metiram, metominostrobin, metrafenone,
metsulfovax, milneb, morpholine fungicides, myclobutanil,
myclozolin, N-(ethylmercury)-p-toluenesulphonanilide, nabam,
natamycin, nitrostyrene, nitrothal-isopropyl, nuarimol, OCH,
octhilinone, ofurace, organomercury fungicides, organophosphorus
fungicides, organotin fungicides, orysastrobin, oxadixyl, oxathiin
fungicides, oxazole fungicides, oxine copper, oxpoconazole,
oxycarboxin, pefurazoate, penconazole, pencycuron,
pentachlorophenol, penthiopyrad, phenylmercuriurea, phenylmercury
acetate, phenylmercury chloride, phenylmercury derivative of
pyrocatechol, phenylmercury nitrate, phenylmercury salicylate,
phenylsulfamide fungicides, phosdiphen, phthalide, phthalimide
fungicides, picoxystrobin, piperalin, polycarbamate, polymeric
dithiocarbamate fungicides, polyoxins, polyoxorim, polysulfide
fungicides, potassium azide, potassium polysulfide, potassium
thiocyanate, probenazole, prochloraz, procymidone, propamocarb,
propiconazole, propineb, proquinazid, prothiocarb, prothioconazole,
pyracarbolid, pyraclostrobin, pyrazole fungicides, pyrazophos,
pyridine fungicides, pyridinitril, pyrifenox, pyrimethanil,
pyrimidine fungicides, pyroquilon, pyroxychlor, pyroxyfur, pyrrole
fungicides, quinacetol, quinazamid, quinconazole, quinoline
fungicides, quinone fungicides, quinoxaline fungicides, quinoxyfen,
quintozene, rabenzazole, salicylanilide, silthiofam, simeconazole,
sodium azide, sodium orthophenylphenoxide, sodium
pentachlorophenoxide, sodium polysulfide, spiroxamine,
streptomycin, strobilurin fungicides, sulfonanilide fungicides,
sulfur, sultropen, TCMTB, tebuconazole, tecloftalam, tecnazene,
tecoram, tetraconazole, thiabendazole, thiadifluor, thiazole
fungicides, thicyofen, thifluzamide, thiocarbamate fungicides,
thiochlorfenphim, thiomersal, thiophanate, thiophanate-methyl,
thiophene fungicides, thioquinox, thiram, tiadinil, tioxymid,
tivedo, tolclofos-methyl, tolnaftate, tolylfluanid, tolylmercury
acetate, triadimefon, triadimenol, triamiphos, triarimol,
triazbutil, triazine fungicides, triazole fungicides, triazoxide,
tributyltin oxide, trichlamide, tricyclazole, tridemorph,
trifloxystrobin, triflumizole, triforine, triticonazole,
unclassified fungicides, undecylenic acid, uniconazole, urea
fungicides, validamycin, valinamide fungicides, vinclozolin,
zarilamid, zinc naphthenate, zineb, ziram, zoxamide and their
mixtures.
[0148] Herbicides:
[0149] A herbicide is a pesticide used to kill unwanted plants.
Selective herbicides kill specific targets while leaving the
desired crop relatively unharmed. Some of these act by interfering
with the growth of the weed and are often based on plant hormones.
Herbicides used to clear waste ground are nonselective and kill all
plant material with which they come into contact. Herbicides are
widely used in agriculture and in landscape turf management. They
are applied in total vegetation control (TVC) programs for
maintenance of highways and railroads. Smaller quantities are used
in forestry, pasture systems, and management of areas set aside as
wildlife habitat. In the following, a number of suitable herbicides
are compiled: [0150] 2,4-D, a broadleaf herbicide in the phenoxy
group used in turf and in no-till field crop production. Now mainly
used in a blend with other herbicides that act as synergists, it is
the most widely used herbicide in the world, third most commonly
used in the United States. It is an example of synthetic auxin
(plant hormone). [0151] Atrazine, a triazine herbicide used in corn
and sorghum for control of broadleaf weeds and grasses. It is still
used because of its low cost and because it works as a synergist
when used with other herbicides, it is a photosystem II inhibitor.
[0152] Clopyralid, a broadleaf herbicide in the pyridine group,
used mainly in turf, rangeland, and for control of noxious
thistles. Notorious for its ability to persist in compost. It is
another example of synthetic auxin. [0153] Dicamba, a persistent
broadleaf herbicide active in the soil, used on turf and field
corn. It is another example of synthetic auxin. [0154] Glyphosate,
a systemic nonselective (it kills any type of plant) herbicide used
in no-till burn-down and for weed control in crops that are
genetically modified to resist its effects. It is an example of a
EPSPs inhibitor. [0155] Imazapyr, a non-selective herbicide used
for the control of a broad range of weeds including terrestrial
annual and perennial grasses and broadleaved herbs, woody species,
and riparian and emergent aquatic species. [0156] Imazapic, a
selective herbicide for both the pre- and post-emergent control of
some annual and perennial grasses and some broadleaf weeds.
Imazapic kills plants by inhibiting the production of branched
chain amino acids (valine, leucine, and isoleucine) which are
necessary for protein synthesis and cell growth. [0157]
Metoalachlor, a pre-emergent herbicide widely used for control of
annual grasses in corn and sorghum; it has largely replaced
atrazine for these uses. [0158] Paraquat, a nonselective contact
herbicide used for no-till burndown and in aerial destruction of
marijuana and coca plantings. More acutely toxic to people than any
other herbicide in widespread commercial use. [0159] Picloram, a
pyridine herbicide mainly used to control unwanted trees in
pastures and edges of fields. It is another synthetic auxin. [0160]
Triclopyr.
[0161] Insecticides: An insecticide is a pesticide used against
insects in all developmental forms. They include ovicides and
larvicides used against the eggs and larvae of insects.
Insecticides are used in agriculture, medicine, industry and the
household. In the following, suitable insecticides are mentioned:
[0162] Chlorinated insecticides, such as, for example, Camphechlor,
DDT, Hexachloro cyclohexane, gamma-Hexachlorocyclohexane,
Methoxychlor, Pentachlorophenol, TDE, Aldrin, Chlordane,
Chlordecone, Dieldrin, Endosulfan, Endrin, Heptachlor, Mirex and
their mixtures; [0163] Organophosphorus compounds, such as, for
example, Acephate, Azinphos-methyl, Ben isulide, Chlorethoxyfos,
Chlorpyrifos, Chlorpyriphos-methyl, Diazinon, Dichlorvos (DDVP),
Dicrotophos, Dimethoate, Disulfoton, Ethoprop, Fenamiphos,
Fenitrothion, Fenthion, Fosthiazate, Malathion, Methamidophos,
Methidathion, Methyl-parathion, Mevinphos, Naled, Omethoate,
Oxydemeton-methyl, Parathion, Phorate, Phosalone, Phosmet,
Phostebupirim, Pirimiphos-methyl, Profenofos, Terbufos,
Tetrachlorvinphos, Tribufos, Trichlorfon and their mixture; [0164]
Carbamates, such as, for example, Aldicarb, Carbofuran, Carbaryl,
Methomyl, 2-(1-Methylpropyl)phenyl methylcarbamate and their
mixtures; [0165] Pyrethroids, such as, for example, Allethrin,
Bifenthrin, Deltamethrin, Permethrin, Resmethrin, Sumithrin,
Tetramethrin, Tralomethrin, Transfluthrin and their mixtures;
[0166] Plant toxin derived compounds, such as, for example, Derris
(rotenone), Pyrethrum, Neem (Azadirachtin), Nicotine, Caffeine and
their mixtures.
[0167] Rodenticides:
[0168] Rodenticides are a category of pest control chemicals
intended to kill rodents. Rodents are difficult to kill with
poisons because their feeding habits reflect their place as
scavengers. They would eat a small bit of something and wait, and
if they do not get sick, they would continue eating. An effective
rodenticide must be tasteless and odorless in lethal concentrations
and have a delayed effect. In the following, examples for suitable
rodenticides are given: [0169] Anticoagulants are defined as
chronic (death occurs after 1 to 2 weeks post ingestion of the
lethal dose, rarely sooner), single-dose (second generation) or
multiple dose (first generation) cumulative rodenticides. Fatal
internal bleeding is caused by lethal dose of anticoagulants, such
as brodifacoum, coumatetralyl or warfarin. These substances in
effective doses are antivitamins K, blocking the enzymes
K1-2,3-epoxide-reductase (this enzyme is preferentially blocked by
4-hydroxycoumarin/4-hydroxythiacoumarin derivatives) and
K1-qui-none-reductase (this enzyme is preferentially blocked by
indandione derivatives), depriving the organism of its source of
active vitamin K1. This leads to a disruption of the vitamin K
cycle, resulting in an inability of production of essential
blood-clotting factors (mainly coagulation factors II
(prothrombin), VII (proconvertin), IX (Christmas factor) and X
(Stuart factor)). In addition to this specific metabolic
disruption, toxic doses of 4-hydroxycoumarin/4-hydroxythiacoumarin
and indandione anticoagulants are causing damage to tiny blood
vessels (capillaries), increasing their permeability, causing
diffuse internal bleedings (haemorrhagins). These effects are
gradual; they develop in the course of days and are not accompanied
by any nociceptive perceptions, such as pain or agony. In the final
phase of intoxication the exhausted rodent collapses in hypovolemic
circulatory shock or severe anemia and dies calmly. Rodenticidal
anticoagulants are either first generation agents
(4-hydroxycoumarin type: warfarin, coumatetralyl; indandione type:
pindone, diphacinone, chlorophacinone), generally requiring higher
concentrations (usually between 0.005 and 0.1%), consecutive intake
over days in order to accumulate the lethal dose, poor active or
inactive after single feeding and less toxic than second generation
agents, which are derivatives of 4-hydroxycoumarin (difenacoum,
brodifacoum, bromadiolone and flocoumafen) or
4-hydroxy-1-benzothiin-2-one (4-hydroxy-1-thiacoumarin, sometimes
incorrectly referred to as 4-hydroxy-1-thiocoumarin, for reason see
heterocyclic compounds), namely difethialone. Second generation
agents are far more toxic than first generation agents, they are
generally applied in lower concentrations in baits (usually in the
order of 0.001 to 0.005%) and are lethal after single ingestion of
bait and are effective also against strains of rodents that have
become resistant against first generation anticoagulants; thus, the
second generation anti-coagulants are sometimes referred to as
"superwarfarins". Sometimes, anticoagulant rodenticides are
potentiated by an antibiotic, most commonly by sulfaquinoxaline.
The aim of this association (e.g. warfarin 0.05%+sulfaquinoxaline
0.02%, or difenacoum 0.005%+sulfaquinoxaline 0.02% etc.) is that
the antibiotic/bacteriostatic agent suppresses intestinal/gut
symbiotic microflora that represents a source of vitamin K. Thus,
the symbiotic bacteria are killed or their metabolism is impaired
and the production of vitamin K by them is diminuted, an effect
which logically contributes to the action of anticoagulants.
Antibiotic agents other than sulfaquinoxaline may be used, for
example co-trimoxazole, tetracycline, neomycin or metronidazole. A
further synergism used in rodenticidal baits is that of an
association of an anticoagulant with a compound with vitamin
D-activity, i.e. cholecalciferol or ergocalciferol (see below). A
typical formula used is, e. g., warfarin 0.025 to
0.05%+cholecalciferol 0.01%. In some countries there are even fixed
three-component rodenticides, i.e. anticoagulant+antibiotic+vitamin
D, e. g. difenacoum 0.005%+sulfaquinoxaline 0.02%+cholecalciferol
0.01%. Associations of a second-generation anticoagulant with an
antibiotic and/or vitamin D are considered to be effective even
against the most resistant strains of rodents, though some second
generation anticoagulants (namely brodifacoum and difethialone), in
bait concentrations of 0.0025-0.005% are so toxic that no known
resistant strain of rodents exists and even rodents resistant
against any other derivatives are reliably exterminated by
application of these most toxic anticoagulants. [0170] Vitamin K1
has been suggested and successfully used as an antidote for pets or
humans which/who were either accidentally or intentionally (poison
assaults on pets, suicidal attempts) exposed to anticoagulant
poisons. In addition, since some of these poisons act by inhibiting
liver functions and in progressed stages of poisoning, several
blood-clotting factors as well as the whole volume of circulating
blood lacks, a blood transfusion (optionally with the clotting
factors present) can save a person's life who inadvertently takes
them, which is an advantage over some older poisons. [0171] Metal
phosphides have been used as a means of killing rodents and are
considered single-dose fast acting rodenticides (death occurs
commonly within 1 to 3 days after single bait ingestion). A bait
consisting of food and a phosphide (usually zinc phosphide) is
left, where the rodents can eat it. The acid in the digestive
system of the rodent reacts with the phosphide to generate the
toxic phosphine gas. This method of vermin control has possible use
in places where rodents are resistant to some of the
anticoagulants, particularly for control of house and field mice;
zinc phosphide baits are also cheaper than most second-generation
anticoagulants, so that sometimes, in cases of large infestation by
rodents, their population is initially reduced by copious amounts
of zinc phosphide bait applied, and the rest of the population that
survived the initial fast-acting poison is then eradicated by
prolonged feeding on anticoagulant bait. Inversely, the individual
rodents that survived anticoagulant bait poisoning (rest
population) can be eradicated by pre-baiting them with nontoxic
bait for a week or two (this is important to overcome bait shyness
and to get rodents used to feeding in specific areas by offering
specific food, especially when eradicating rats) and subsequently
applying poisoned bait of the same sort as used for pre-baiting
until all consumption of the bait ceases (usually within 2 to 4
days). These methods of alternating rodenticides with different
modes of action provides a factual or an almost 100% eradication of
the rodent population in the area if the acceptance/palatability of
bait is good (i.e., rodents readily feed on it). [0172] Phosphides
are rather fast acting rat poisons, resulting in that the rats are
dying usually in open areas instead of the affected buildings.
Typical examples are aluminum phosphide (fumigant only), calcium
phosphide (fumigant only), magnesium phosphide (fumigant only) and
zinc phosphide (in baits). Zinc phosphide is typically added to
rodent baits in amounts of around 0.75 to 2%. The baits have a
strong, pungent garlic-like odor characteristic for phosphine
liberated by hydrolysis. The odor attracts (or, at least, does not
repulse) rodents, but has a repulsive effect on other mammals;
birds, however (notably wild turkeys), are not sensitive to the
smell and feed on the bait thus becoming collateral damage. [0173]
Hypercalcemia. Calciferols (vitamins D), cholecalciferol (vitamin
D3) and ergocalciferol (vitamin D2) are used as rodenticides which
are toxic to rodents for the same reason that they are beneficial
to mammals: they are affecting calcium and phosphate homeostasis in
the body. Vitamins D are essential in minute quantities (few IUs
per kilogram body weight daily, which is only a fraction of a
milligram), and like most fat soluble vitamins they are toxic in
larger doses as they readily result in the so-called
hypervitaminosis which is, simply said, poisoning by the vitamin.
If the poisoning is severe enough (that is, if the dose of the
toxicant is high enough), it eventually leads to death. In rodents
consuming the rodenticidal bait it causes hypercalcemia by raising
the calcium level, mainly by increasing calcium absorption from
food, mobilising bone-matrix-fixed calcium into ionized form
(mainly monohydrogen-carbonate calcium cation, partially bound to
plasma proteins, [CaHCO.sub.3].sup.+) which circulates dissolved in
the blood plasma, and after ingestion of a lethal dose the free
calcium levels are raised sufficiently, so that blood vessels,
kidneys, the stomach wall and lungs are min-eralised/calcificated
(formation of calcificates, crystals of calcium salts/complexes in
the tissues thus damaging them), leading further to heart problems
(myocard is sensitive to variations of free calcium levels that are
affecting both myocardial contractibility and excitation
propagation between atrias and ventriculas) and bleeding (due to
capillary damage) and possibly kidney failure. It is considered to
be single-dose or cumulative (depending on concentration used; the
common 0.075% bait concentration is lethal to most rodents after a
single intake of larger portions of the bait), sub-chronic (death
occurring usually within days to one week after ingestion of the
bait). Applied concentrations are 0.075% cholecalciferol and 0.1%
ergocalciferol when used alone. There is an important feature of
calciferols toxicology which is that they are synergistic with
anticoagulant toxicants. This means that mixtures of anticoagulants
and calciferols in the same bait are more toxic than the sum of
toxicities of the anticoagulant and the calciferol in the bait, so
that a massive hypercalcemic effect can be achieved by a
substantially lower calciferol content in the bait and vice-versa.
More pronounced anticoagulant/hemorrhagic effects are observed if
calciferol is present. This synergism is mostly used in baits low
in calciferol because effective concentrations of calciferols are
more expensive than effective concentrations of most
anticoagulants. The historically very first application of a
calciferol in rodenticidal bait was, in fact, the Sorex product
Sorexa.RTM. D (with a different formula than today's Sorexa.RTM. D)
back in the early 1970's, containing warfarin 0.025%+ergocalciferol
0.1%. Today, Sorexa.RTM. CD contains a 0.0025% difenacoum+0.075%
cholecalciferol combination. Numerous other brand products
containing either calciferols 0.075 to 0.1% (e. g. Quintox.RTM.,
containing 0.075% cholecalciferol) alone, or a combination of
calciferol 0.01 to 0.075% with an anticoagulant are marketed.
[0174] Miticides, Moluscicides and Nematicides:
[0175] Miticides are pesticides that kill mites. Antibiotic
miticides, carbamate miticides, formamidine miticides, mite growth
regulators, organochlorine, permethrin and organophosphate
miticides all belong to this category. Molluscicides are pesticides
used to control mollusks, such as moths, slugs and snails. These
substances include metaldehyde, methiocarb and aluminium sulfate. A
nematicide is a type of chemical pesticide used to kill parasitic
nematodes (a phylum of worm). A nematicide is obtained from a neem
tree's seed cake; which is the residue of neem seeds after oil
extraction. The neem tree is known by several names in the world,
but was first cultivated in India since ancient times.
[0176] Antimicrobials:
[0177] In the following examples, antimicrobials suitable for
agrochemical compositions according to the present invention are
given. Bactericidal disinfectants mostly used are those applying
[0178] active chlorine (i.e., hypochlorites, chloramines,
dichloroisocyanurate and trichloroisocyanurate, wet chlorine,
chlorine dioxide, etc.), [0179] active oxygen (peroxides, such as
peracetic acid, potassium persulfate, sodium perborate, sodium
percarbonate and urea perhydrate), [0180] iodine (iodpovidone
(povidone-iodine, Betadine), Lugol's solution, iodine tincture,
iodinated nonionic surfactants), [0181] concentrated alcohols
(mainly ethanol, 1-propanol, called also n-propanol and 2-propanol,
called isopropanol and mixtures thereof; further, 2-phenoxyethanol
and 1- and 2-phenoxy-propanols are used), [0182] phenolic
substances (such as, phenol (also called "carbolic acid"), cresols
(called "Lysole" in combination with liquid potassium soaps),
halogenated (chlorinated, brominated) phenols, such as
hexachlorophene, triclosan, trichlorophenol, tribromophenol,
pentachlorophenol, Dibromol and salts thereof), [0183] cationic
surfactants, such as some quaternary ammonium cations (such as
benzalkonium chloride, cetyl trimethylammonium bromide or chloride,
didecyldimethylammonium chloride, cetylpyridinium chloride,
benzethonium chloride) and others, non-quarternary compounds, such
as chlorhexidine, glucoprotamine, octenidine dihydrochloride,
etc.), [0184] strong oxidizers, such as ozone and permanganate
solutions, heavy metals and their salts, such as colloidal silver,
silver nitrate, mercury chloride, phenylmercury salts, copper
sulfate, copper oxide-chloride, etc. Heavy metals and their salts
are the most toxic and environmentally hazardous bactericides and,
therefore, their use is strongly suppressed or forbidden; further,
also [0185] properly concentrated strong acids (phosphoric, nitric,
sulfuric, amidosulfuric, toluenesulfonic acids) and [0186] alcalis
(sodium, potassium, calcium hydroxides) between pH<1 or >13,
particularly below elevated temperatures (above 60.degree. C.) kill
bacteria.
[0187] As antiseptics (i.e., germicide agents that can be used on
human or animal body, skin, mucoses, wounds and the like), few of
the above mentioned disinfectants can be used under proper
conditions (mainly concentration, pH, temperature and toxicity
toward man/animal). Among them, important are [0188] Some properly
diluted chlorine preparations (e. g. Daquin's solution, 0.5% sodium
or potassium hypochlorite solution, pH-adjusted to pH 7 to 8, or
0.5 to 1% solution of sodium benzenesulfochloramide (chloramine
B)), some [0189] iodine preparations, such as iodopovidone in
various galenics (ointments, solutions, wound plasters), in the
past also Lugol's solution, [0190] peroxides as urea perhydrate
solutions and pH-buffered 0.1 to 0.25% peracetic acid solutions,
[0191] alcohols with or without antiseptic additives, used mainly
for skin antisepsis, [0192] weak organic acids, such as sorbic
acid, benzoic acid, lactic acid and salicylic acid [0193] some
phenolic compounds, such as hexachlorophene, triclosan and Dibromol
and [0194] cation-active compounds, such as 0.05-0.5% benzalkonium,
0.5-4% chlorhexidine, 0.1-2% octenidine solutions.
[0195] Bactericidal antibiotics kill bacteria; bacteriostatic
antibiotics only slow down their growth or reproduction. Penicillin
is a bactericide, as are cephalosporins. Aminoglycosidic
antibiotics can act in both a bactericidic manner (by disrupting
cell wall precursor leading to lysis) or bacteriostatic manner (by
connecting to 30s ribosomal subunit and reducing translation
fidelity leading to inaccurate protein synthesis). Other
bactericidal antibiotics according to the present invention include
the fluoroquinolones, nitrofurans, vancomycin, monobactams,
co-trimoxazole, and metronidazole. The preferred biocides are
selected from the group consisting of oxyfluorfen, glyphosate,
tebucanozol, desmedipham, phenmedipham, ethofumesat and their
mixtures.
[0196] A further class of lipophilic components that can be
encapsulated are emollients.
[0197] Preferably, the lipophilic components comprise at least one
emollient capable to dissolve the polyisocyanates employed in step
b). More preferably, these emollients are capable to dissolve the
polyisocyanates without extraneous solvents and/or auxiliaries.
Should an emollient not ensure adequate solubility of the
polyisocyanates, there is the option of overcoming this
disadvantage by using suitable solubility promoters.
[0198] An emollient is a material that softens, soothes, supplies,
coats, lubricates, moisturizes, or cleanses the skin. An emollient
typically accomplishes several of these objectives, such as
soothing, moisturizing, and lubricating the skin. Preferred are
selected from petroleum-based, fatty acid ester type, alkyl
ethoxylate type, fatty acid ester ethoxylates, fatty alcohol type,
polysiloxane type, or mixtures thereof.
[0199] A further class of lipophilic components that can be
encapsulated are dyes.
[0200] Preferably, the lipophilic components comprise at least one
dye capable to dissolve the polyisocyanates employed in step b).
More preferably, these dyes are capable to dissolve the
polyisocyanates without extraneous solvents and/or auxiliaries.
Should an dye not ensure adequate solubility of the
polyisocyanates, there is the option of overcoming this
disadvantage by using suitable solubility promoters.
[0201] Preferred dyes according to the invention are dyes suitable
and approved for cosmetic purposes. Examples include cochineal red
A (C.I. 16255), patent blue V (C.I. 42051), indigotin (C.I. 73015),
chlorophyllin (C.I. 75810), quinoline yellow (C.I. 47005), titanium
dioxide (C.I. 77891), indanthrene blue RS (C.I. 69800) and madder
lake (C.I. 58000). These dyes are normally used in concentrations
of 0.001 to 0.1% by weight, based on the mixture as a whole.
[0202] A further class of lipophilic components that can be
encapsulated are cosmetically active ingredients.
[0203] Preferably the lipophilic component comprise at least one
cosmetically active ingredient capable to dissolve the
polyisocyanates employed in step b). More preferably, these
cosmetically active ingredients are capable to dissolve the
polyisocyanates without extraneous solvents and/or auxiliaries.
Should an cosmetically active ingredients not ensure adequate
solubility of the polyisocyanates, there is the option of
overcoming this disadvantage by using suitable solubility
promoters.
[0204] Specifically suitable cosmetically compatible oil bodies are
described in Karl-Heinz Schrader, Grundlagen and Rezepturen der
Kosmetika [Fundamentals and formulations of cosmetics], 2nd
edition, Verlag Huthig, Heidelberg, pp. 319-355, to which reference
is made here.
[0205] Suitable cosmetically active ingredients are, for example,
skin and hair pigmentation agents, tanning agents, bleaches,
keratin-hardening substances, antimicrobial active ingredients,
photofilter active ingredients, repellent active ingredients,
hyperemic substances, keratolytic and kerato-plastic substances,
antidandruff active ingredients, antiphlogistics, keratinizing
substances, active ingredients which have an antioxidative effect
and/or free-radical scavenging effect, skin-moisturizing or
-humectant substances, refatting active ingredients, deodorizing
active ingredients, sebostatic active ingredients, plant extracts,
antierythimatous or antiallergic active ingredients and mixtures
thereof.
[0206] Artificially skin-tanning active ingredients which are
suitable for tanning of the skin without natural or artificial
irradiation with UV rays are, for example, dihydroxyacetone,
alloxan and walnut shell extract. Suitable keratin-hardening
substances are generally active ingredients as are also used in
antiperspirants, such as, for example, potassium aluminum sulfate,
aluminum hydroxychloride, aluminum lactate, etc. Antimicrobial
active ingredients are used in order to destroy microorganisms
and/or to inhibit their growth and thus serve both as preservatives
and also as deodorizing substance which reduces the development or
the intensity of body odor. These include, for example, customary
preservatives known to the person skilled in the art, such as
p-hydroxybenzoic acid esters, imidazolidinylurea, formaldehyde,
sorbic acid, benzoic acid, salicylic acid, etc. Deodorizing
substances of this type are, for example, zinc ricinoleate,
triclosan, undecylenic acid alkylolamides, triethyl citrate,
chlorhexidine, etc. Suitable photofilter active ingredients are
substances which absorb UV rays in the UV-B and/or UV-A region.
Suitable UV filters are those specified above. Also suitable are
p-aminobenzoic acid esters, cinnamic acid esters, benzophenones,
camphor derivatives and pigments which stop UV rays, such as
titanium dioxide, talc and zinc oxide. Suitable repellent active
ingredients are compounds which are able to deter or drive away
certain animals, in particular insects, from people. These include,
for example, 2-ethyl-1,3-hexanediol, N,N-diethyl-m-toluamide, etc.
Suitable hyperemic substances, which stimulate blood flow through
the skin, are, for example, essential oils, such as dwarf-pine,
lavender, rosemary, juniper berry, horse chestnut extract, birch
leaf extract, hay flower extract, ethyl acetate, camphor, menthol,
peppermint oil, rosemary extract, eucalyptus oil, etc. Suitable
keratolytic and kerato-plastic substances are, for example,
salicylic acid, calcium thioglycolate, thioglycolic acid and its
salts, sulfur, etc. Suitable antidandruff active ingredients are,
for example, sulfur, sulfur polyethylene glycol sorbitan
monooleate, sulfur ricinol polyethoxylate, zinc pyrithione,
aluminum pyrithione, etc. Suitable antiphlogistics which counteract
skin irritations, are, for example, allantoin, bisabolol,
dragosantol, camille extract, panthenol, etc.
[0207] A further class of lipophilic components that can be
encapsulated are pharmaceutically ingredients.
[0208] Preferably, the lipophilic components comprise at least one
pharmaceutically ingredient capable to dissolve the polyisocyanates
employed in step b). More preferably, these pharmaceutically
ingredients are capable to dissolve the polyisocyanates without
extraneous solvents and/or auxiliaries. Should a pharmaceutically
ingredient not ensure adequate solubility of the polyisocyanates,
there is the option of overcoming this disadvantage by using
suitable solubility promoters.
[0209] In principle, all pharmaceutical active substances and
prodrugs are suitable for the use of the lipophilic components
according to the invention. These include benzodiazepines,
antihypertensives, vitamins, cytostatics, in particular taxol,
anesthetics, neuroleptics, antidepressants, antibiotics,
antimycotics, fungicides, chemotherapeutics, urologics, thrombocyte
aggregation inhibitors, sulfonamides, spasmolytics, hormones,
immunoglobulins, sera, thyroid therapeutic agents,
psychopharmacological agents, antiparkinsonians and other
antihyperkinetic agents, ophthalmics, neuropathy preparations,
calcium metabolism regulators, muscle relaxants, narcotics,
antilipemics, hepatic therapeutic agents, coronary agents,
cardiacs, immuno-therapeutics, regulatory peptides and their
inhibitors, hypnotics, sedatives, gynecological agents, antigouts,
fibrinolytic agents, enzyme preparations and transport proteins,
enzyme inhibitors, emetics, circulation-promoting agents,
diuretics, diagnostics, corticoids, cholinergics, bile duct
therapeutics, antiasthmatics, broncholytics, beta-receptor
blockers, calcium antagonists, ACE inhibitors,
antiarteriosclerotics, antiinflammatories, anticoagulants,
antihypotensives, anti-hypoglycemics, antihypertonics,
antifibrinolytics, antiepileptics, antiemetics, antidotes,
anti-diabetics, antiarrhythmics, antianemics, antiallergics,
anthelmintics, analgesics, analeptics, aldosterone antagonists and
slimming agents. Examples of suitable pharmaceutical active
substances are in particular the active substances mentioned in
paragraphs 0105 to 0131 of US 2003/0157170.
[0210] The lipophilic component preferably comprises a
pharmaceutically acceptable auxiliary. Of pharmaceutical
acceptability are the auxiliaries that are known for use in the
field of pharmacy, food technology and related fields, in
particular the auxiliaries listed in relevant pharmacopoeia (e.g.
DAB, Ph. Eur., BP, NF), as well as other auxiliaries whose
properties do not preclude a physiological use.
[0211] Suitable cosmetically and pharmaceutically acceptable
auxiliaries are also described in Fiedler, H. P. Lexikon der
Hilfsstoffe fur Pharmazie, Kosmetik and angrenzende Gebiete
[Lexicon of the auxiliaries for pharmacy, cosmetics and related
fields], 4th edition, Aulendorf: ECV-Editio-Kantor-Verlag,
1996.
[0212] A further class of lipophilic components that can be
encapsulated are compositions used for industrial or institutional
or hospital applications.
[0213] Preferably, the lipophilic components comprise at least one
compositions used for industrial or institutional or hospital
applications capable to dissolve the polyisocyanates employed in
step b). More preferably, these are compositions used for
industrial or institutional or hospital applications are capable to
dissolve the polyisocyanates without extraneous solvents and/or
auxiliaries. Should a composition used for industrial or
institutional or hospital applications not ensure adequate
solubility of the polyisocyanates, there is the option of
overcoming this disadvantage by using suitable solubility
promoters.
[0214] Suitable compositions used for industrial or institutional
or hospital applications are, for example, chelants of heavy metal
and hardness ions (builders), scale inhibiting agents, corrosion
inhibiting agents, deflocculating/dispensing agents, stain removal
agents, bleach stabilizing agents, protecting agents of peroxygen
labile ingredients, photobleaching enhancing agents,
thickener/viscosity modifying agents, crystal growth modification
agents, sludge modification agents, surface modification agents,
processing aids, electrolyte, hydrolytic stability agents,
alkalinity agents and the like. The lipophilic components are
compounds which are also useful for certain industrial
applications, such as acid cleaners, aluminum etching, boiler
cleaning, water treatment, bottle washing, cement modification,
dairy cleaners, desalination, electrochemical machining,
electroplating, metal finishing, paper mill evaporations, oil field
water treatment, paper pulp bleaching, pigment dispersion, trace
metal carrier for fertilizers, irrigation, circuit cleaning and the
like.
[0215] A further class of lipophilic components that can be
encapsulated are textile treatment compositions.
[0216] Preferably, the lipophilic components comprise at least one
textile treatment composition capable to dissolve the
polyisocyanates employed in step b). More preferably, these textile
treatment compositions are capable to dissolve the polyisocyanates
without extraneous solvents and/or auxiliaries. Should a textile
treatment composition not ensure adequate solubility of the
polyisocyanates, there is the option of overcoming this
disadvantage by using suitable solubility promoters.
[0217] Suitable textile treatment compositions are softening
compositions, such as liquid fabric softeners, fabric softening
rinses, fabric softening sheets, tissue papers, paper towels,
facial tissues, sanitary tissues, toilet paper and the like.
[0218] A further class of lipophilic components that can be
encapsulated are vitamins. Suitable water-insoluble vitamins and
provitamins are e.g. vitamin A, vitamin A acetate, vitamin D,
vitamin E, tocopherol derivatives, such as tocopherol acetate and
vitamin K.
[0219] Further, premix (II) comprises at least one
polyisocyanate.
[0220] Isocyanates are N-substituted organic derivatives
(R--N.dbd.C.dbd.O) of isocyanic acid (HNCO) tautomeric in the free
state with cyanic acid. Organic isocyanates are compounds in which
the isocyanate group (--N.dbd.C.dbd.O) is bonded to an organic
radical. Polyfunctional isocyanates are compounds with two or more
(e.g. 3, 4, 5, etc.) isocyanate groups in the molecule.
[0221] Preferably, the polyisocyanate employed in step b) comprises
at least one difunctional isocyanate. In a special embodiment, the
polyisocyanate employed in step b) is exclusively selected from
difunctional isocyanates, the allophanates, isocyanurates,
uretdiones or carbodiim ides of difunctional isocyanates and
mixtures thereof.
[0222] In general, suitable polyisocyanates are all aromatic,
alicyclic and aliphatic isocyanates, provided they have at least
two reactive isocyanate groups.
[0223] Preferably, the polyisocyanate component has an average
content of 2 to 4 NCO groups. Preference is given to using
diisocyanates, i.e. esters of isocyanic acid with the general
structure O.dbd.C.dbd.N--R''--N.dbd.C.dbd.O, where R' is an
aliphatic, alicyclic or aromatic radical.
[0224] Suitable polyisocyanates are chosen from compounds with 2 to
5 isocyanate groups, isocyanate prepolymers with an average number
of from 2 to 5 isocyanate groups and mixtures thereof. These
include, for example, aliphatic, cycloaliphatic and aromatic di-,
tri- and higher polyisocyanates.
[0225] Preferably, the polyisocyanate is selected from
hexamethylene diisocyanate (HDI), tetramethylene diisocyanate,
ethylene diisocyanate, 1,2-diisocyanatododecane,
4-iso-cyanatomethyl-1,8-octamethylene diisocyanate,
triphenylmethane-4,4',4''-triisocyanate,
1,6-diisocyanato-2,2,4-trimethylhexane,
1,6-diisocyanato-2,4,4-trimethylhexane, isophorone diisocyanate
(=3-Isocyanatmethyl-3,5,5-trimethylcyclohexylisocyanat,
1-Isocyanato-3-isocyanato-methyl-3,5,5-trimethylcyclohexan, IPDI),
2,3,3-trimethylhexamethylene diisocyanate, 1,4-cyclo-hexylene
diisocyanate, 1-methyl-2,4-diisocyanatocyclohexane,
dicyclohexylmethane-4,4'-diisocyanate
(=methylene-bis(4-cyclohexylisocyanate)), 1,3-phenylene
diisocyanate, 1,4-phenylene diisocyanate, 2,4- and 2,6-toluylene
diisocyanate and isomer mixtures thereof, 1,5-naphthylene
diisocyanate, 2,4''- and 4,4'-diphenylmethane diisocyanate (MOi),
mixtures of diphenylmethane diisocyanates and more highly
polycyclic homologs of diphenylmethane diisocyanate (polymeric
MDI), hydrogenated 4,4'-diphenylmethane diisocyanate (H12MD1),
xylylene diisocyanate (XDI), tetramethylxylol diisocyanate (TMXDI),
4,4'-dibenzyl diisocyanate, 4,4'-diphenyldimethylmethane
diisocyanate, di- and tetraalkyldiphenylmethandiisocyanates, dimer
fatty acid diisocyanates, chlorinated and brominated diisocyanates,
4,4''-diisocyanatophenylperfluoroethane,
tetra-methoxybutane-1,4-diisocyanate, phosphorus-containing
diisocyanates, sulfur-containing diisocyanares, anionically
modified polyisocyanates, polyethylene oxide-containing isocyanate,
oligomers of the afore-mentioned polyisocyanates that contain
urethane, allophanate, isocyanurate, uretdione, carbodiimide or
biuret groups, and mixtures thereof.
[0226] Suitable chlorinated and brominated polyisocyanates comprise
polyisocyanates with reactive halogen atoms. Preferably, the
chlorinated and brominated polyisocyanate is selected from
1-chloromethylphenyl 2,4-diisocyanate, 1-bromomethylphenyl
2,6-diisocyanate, 3,3-bischloromethyl ether
4,4'-diphenyldiisocyanate.
[0227] Suitable sulfur-containing polyisocyanates are obtained, for
example, by reacting 2 mol of hexamethylene diisocyanate with 1 mol
of thiodiglycol or dihydroxydihexyl sulfide.
[0228] Preferably, the anionically modified polyisocyanates contain
at least two isocyanate groups and at least one anionic or
aniogenic group in the molecule. Suitable anionic or aniogenic
groups are carboxylic acid groups, sulfonic acid groups, phosphonic
acids groups and the salts thereof. Preferably, the anionically
modified polyisocyanates contain one or more than one sulfonic acid
group or a salt thereof in the molecule. Suitable salts are e.g.
sodium, potassium and ammonium salts. Ammonium salts are especially
preferred. Preferred bases to neutralize the anionic groups are
selected from, for example, ammonia, NaOH, KOH,
C.sub.1-C.sub.6-alkylamines, preferably n-propyl-amine and
n-butylamine, dialkylamines, preferably diethylpropylamine and
dipropylmethylamine, trialkylamines, preferably triethylamine and
triisopropylamine, C.sub.1-C.sub.6-alkyldiethanolamines, preferably
methyl- or ethyldiethanolamine and
di-C.sub.1-C.sub.6-alkylethanolamines.
[0229] Preferred anionically modified polyisocyanates are obtained
by reaction of polyisocyanates with
2-(cyclohexylamino)-ethanesulfonic acid and/or
3-(cyclohexylamino)-propanesulfonic acid.
[0230] More preferred anionically modified polyisocyanates are
obtained by reaction of polyisocyanates with
2-(cyclohexylamino)-ethanesulfonic acid and/or
3-(cyclohexylamino)-propanesulfonic acid, wherein the
polyisocyanate is delected from hexamethylene diisocyanate,
tetramethylene diisocyanate, isophorone diisocyanate,
dicyclohexylmethane-4,4'-diisocyanate, 2,4- and 2,6-toluylene
diisocyanate and isomer mixtures, diphenylmethane diisocyanates,
biurets, allophanates and/or isocyanurates of the afore-mentioned
polyisocyanates.
[0231] Suitable anionically modified polyisocyanates are described
in US 2004/0034162 which is incorporated herein by reference.
[0232] Preferred anionically modified polyisocyanates have [0233]
an average isocyanate functionality of at least 1.8, [0234] a
content of isocyanate groups (calculated as NCO; molecular
weight=42) of 4.0 to 26.0 wt. %, [0235] a content of sulfonate
groups (calculated as SO.sub.3; molecular weight=80) of 0.1 to 7.7
wt. % and [0236] optionally a content of ethylene oxide units
bonded within polyether chains (calculated as C.sub.2H.sub.2O;
molecular weight=44) of 0 to 19.5 wt. %, wherein the polyether
chains contain a statistical average of 5 to 55 ethylene oxide
units.
[0237] Preferred anionically modified polyisocyanates are selected
from anionically modified hexamethylene diisocyanate, anionically
modified hexamethylene diisocyanate, anionically modified
isocyanurates of hexamethylene diisocyanate and mixtures
thereof.
[0238] Preferred commercially available anionically modified
polyisocyanates are modified isocyanurates of hexamethylene
diisocyanate sold by Bayer AG under the trademark Bayhydur, e.g.
Bayhydur XP. It has the following formula:
##STR00001##
[0239] Suitable polyethylene oxide-containing polyisocyanates have
at least two isocyanate groups and at least one polyethylene group.
Polyethylene oxide-containing isocyanates are described, e.g. in
U.S. Pat. No. 5,342,556. These isocyanates are self-emulsifying in
water, which may be advantageous within the context of the present
process since it may be possible to dispense with a separate
emulsifying step.
[0240] The polyisocyanate preferably comprises at least one
polyisocyanate, selected from hexamethylene diisocyanate,
tetramethylene diisocyanate, isophorone diisocyanate,
dicyclohexylmethane-4,4'-diisocyanate, 2,4- and 2,6-toluylene
diisocyanate and isomer mixtures thereof, 2,4'- and
4,4'-diphenylmethane diisocyanate, the biurets, allophanates and/or
isocyanurates of the afore-mentioned polyisocyanates, anionically
modified polyisocyanates, and mixtures thereof.
[0241] In a special embodiment, the polyisocyanate employed in step
b) comprises two structurally different polyisocyanates (A) and
(B).
[0242] Suitable polyisocyanates of type (A) are nonionic
polyisocyanates bearing at least two NCO groups.
[0243] Preferably, polyisocyanates of type (A) are selected from
hexamethylene diisocyanate, tetramethylene diisocyanate,
dicyclohexylmethane-4,4'-diisocyanate, 2,4- and 2,6-toluylene
diisocyanate and isomer mixtures thereof, 2,4'- and
4,4'-diphenylmethane diisocyanate and isomer mixtures thereof, the
biurets, allophanates and/or isocyanurates of the afore-mentioned
polyisocyanates or mixtures thereof.
[0244] In particular, isocyanates of type (A) are selected from
hexamethylene diisocyanate, isophorone diisocyanate,
dicyclohexylmethane-4,4'-diisocyanate, the isocyanurate of
hexamethylene diisocyanate or mixtures thereof.
[0245] Preferred commercially available isocyanates of type (A) are
hexamethylene diisocyanate sold by Bayer AG under the trademark
Desmodur N3200.TM..
[0246] Also preferred commercially available isocyanates of type
(A) are isophorone diisocyanate sold by Bayer AG under the
trademark Desmodur N3300.TM..
[0247] The second polyisocyanate of type (B) is structurally
different from the isocyanate of type (A). Preferably, the
polyisocyanate of type (B) bears at least two NCO groups and at
least one functional group, selected from anionic/anionogenic
groups, polyethylene groups and combinations thereof.
[0248] Preferably, however, only anionically modified isocyanates
are used as component (B) in the present process.
[0249] Preferably, the polyisocyanate (B) is selected from in each
case anionically modified hexamethylene diisocyanate,
tetramethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate,
2,4- and 2,6-toluylene diisocyanate and isomer mixtures thereof,
2,4'- and 4,4'-diphenylmethane diisocyanate and isomer mixtures
thereof, the biurets, allophanates and/or isocyanurates of the
afore-mentioned polyisocyanates or mixtures thereof.
[0250] In particular, isocyanates of type (B) are selected from in
each case anionically modified hexamethylene diisocyanate,
isophorone diisocyanate, dicyclohexylmethane-4,4''-diisocyanate,
the isocyanurate of hexamethylene diisocyanate or mixtures
thereof.
[0251] In a preferred embodiment, the isocyanates of type (A) are
selected from hexamethylene diisocyanate, isophorone diisocyanate,
dicyclohexylmethane-4,4'-diisocyanate, the isocyanurate of
hexamethylene diisocyanate or mixtures thereof and the isocyanates
of type (B) are selected from anionically modified hexamethylene
diisocyanate, anionically modified isophorone diisocyanate,
anionically modified dicyclohexylmethane-4,4'-diisocyanate, the
anionically modified isocyanurate of hexamethylene diisocyanate or
mixtures thereof.
[0252] In a further preferred embodiment, the premix (II) comprises
at least one nonionic polyisocyanate (A) and at least one
anionically modified isocyanate (B), wherein the anionically
modified diisocyanates (B) preferably contain at least one sulfonic
acid group in the molecule.
[0253] In particular, the polyisocyanate of type (A) is
hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate
or a mixture thereof and the polyisocyanate of type (B) is
anionically modified hexamethylene diisocyanate, anionically
modified isocyanurate of hexamethylene diisocyanate, anionically
modified dicyclohexylmethane-4,4'-diisocyanate or mixtures
thereof.
[0254] The weight ratio of the polyisocyanates (A) and (B) is
preferably in the range from 10:1 to 1:10, more preferably in the
range from 5:1 to 1:5 and in particular in the range from 3:1 to
1:1.
[0255] It is also possible to use mixtures of different isocyanates
of types (A) and (B). Besides the isocyanates (A) and (B), further
isocyanates can also additionally be used in the process according
to the invention.
[0256] In a further preferred embodiment of the present invention,
the lipophilic component is used as the solvent for premix (II).
Preferably, premix (II) contains no extraneous solvents apart from
the lipophilic component.
Step c)
[0257] In step c) the premix (I) and premix (II) are mixed until an
emulsion (III) is formed. In order to form an emulsion (III) in the
present process, the premix (I) and premix (II) are emulsified by
processes known to the person skilled in the art, e.g. by
introducing energy into the mixture through stirring using a
suitable stirrer until the mixture emulsifies.
[0258] A preferred embodiment is a process, wherein [0259] a target
range for the volume average diameter of the droplets of the
hydrophobic (discontinuous phase) of the resulting emulsion (III)
is predefined, [0260] the actual volume average diameter of the
droplets of the hydrophobic phase in the mixture of premix (I) and
premix (II) is determined, [0261] the speed of the stirrer and/or
the time of stirring of the mixture are adjusted until the target
value volume average diameter of the droplets of the hydrophobic
phase of the resulting emulsion (III) is reached in order to obtain
the predefined target volume average diameter of the droplets of
the hydrophobic phase.
[0262] It has been found favourable if the mixture of premix (I)
and premix (II) in step c) is stirred with a speed of the stirrer
of 200 rpm to 1200 rpm, preferably 400 to 800 rpm. Those values are
especially favorable if MIG stirrer is used.
[0263] It has been found favourable if the mixture of premix (I)
and premix (II) is stirred vigorously in streaming conditions with
Reynolds numbers above 10.sup.3 for a time period of only a several
seconds up to a several minutes. The mixture in step c) is stirred
for 1 to 120 minutes, preferably 2 minutes to 60 minutes,
especially 5 to 20 minutes.
[0264] Suitable devices for controlling the volume average diameter
of the droplets of discontinuous phase of the resulting emulsion
are known to those skilled in the art. Such devises are based, for
example, on light scattering measurements. Suitable light
scattering measurements are known to those skilled in the art and
are commercially available from, for example, Malvern Instruments,
e.g. Malvern autosizer.
[0265] The rate of stirring of the mixture of premix (I) and premix
(II) in step c) is adjusted to influence the size of droplets of
hydrophobic phase in the aqueous phase. After a period of vigorous
stirring, an emulsion is obtained, in which the premix (II) is
dispersed as tiny droplets in the aqueous solution of premix (I).
The droplets of the discontinuous phase of the emulsion has a
volume average diameter of 15 to 88 .mu.m.
[0266] The mixture of premix (I) and premix (II) is stirred
vigorously. Preferred stirrer are MIG stirrer, propellers stirrer,
paraviscs stirrer, INTERMIG stirrer and isojet stirrer.
[0267] The pH is preferably adjusted using aqueous bases,
preference being given to using sodium hydroxide solution (e.g. 5%
strength by weight). Preferably the pH of emulsion (III) is
adjusted from 3 to 12, in particular between 4 to 10, and more
particular in the range from 5 to 10.
[0268] In a preferred embodiment, premix (II) comprises a
polyisocyanate (A) which is mixed with premix (I) until an emulsion
is formed. Another polyisocyanate (B) is added to the obtained
emulsion (III). In another preferred embodiment, the polyisocyanate
(A) and polyisocyanare (B) are both contained in the premix (I).
Preferably, first the isocyanate (A) is contained in the premix
(II), and an emulsion with premix (I) is formed and the second the
isocyanate (B) is added to the emulsion (III).
Step d)
[0269] The aqueous solution (IV) comprises at least one
polyfunctional amine. Suitable amines are mentioned below. In a
preferred embodiment, the aqueous solution comprises a bifunctional
amine, preferably comprises or consists of at least one
polyethyleneimine.
[0270] In the sense of the invention, the term polyfunctional amine
denotes amines that comprise at least two groups capable of
reacting with NCO groups, wherein at least one of the groups
capable of reacting with NCO groups is a primary or secondary amino
group. When the polyfunctional amine contains only one primary or
secondary amino group, it will contain one or more additional
functional groups that are capable of reacting with NCO groups in a
polymerisation reaction. Suitable are in principle active hydrogen
atom containing groups. The groups of the polyfunctional amines
that are reactive toward NCO groups are preferably chosen from
hydroxyl groups and primary and secondary amino groups.
[0271] The polyfunctional amine is preferably selected from
diamines, aminoalcohols, polymeric polyamines, guanidines,
melamines, urea, hydrazines and mixtures thereof.
[0272] Suitable diamines are, for example, 1,2-ethylenediamine,
1,3-propylenediamine, 1,4-diamino-butane, 1,5-diaminopentane,
1,6-diaminohexane, 1,3-diamino-1-methylpropane,
1,4-diamino-cyclohexane, piperazin and mixtures thereof.
[0273] Suitable amino alcohols are, for example, 2-aminoethanol,
2-(N-methylamino)ethanol, 3-amino-propanol, 4-aminobutanol,
1-ethylaminobutan-2-ol, 2-amino-2-methyl-1-propanol,
4-methyl-4-aminopentan-2-ol, etc.
[0274] Suitable polymeric polyamines are in principle linear or
branched polymers that have at least two primary or secondary amino
groups. Additionally, these polymers can have tertiary amino groups
in the polymer chain.
[0275] In the processes according to the invention,
polyethyleneimines with a molecular weight of at least 500 g/mol,
preferably from 600 to 30 000 or 650 to 25 000 g/mol and in
particular from 700 to 10 000 g/mol or 850 to 5000 g/mol, are
preferably used.
[0276] Preference is given to polymeric polyamines having a
weight-average molecular weight of at least 500 g/mol. More
preferred are polymeric polyamines having a weight-average
molecular weight of from 500 to 1 000 000, in particular from 650
to 2 000 000, especially from 700 to 100 000, more especially from
800 to 50 000.
[0277] The polymeric polyamine is preferably selected from
polyalkyleneimines, polyvinylamines, polyetheramines, etc. More
preferably, the polymeric polyamine is selected from
polyalkyleneimines, in particular polyethyleneimines.
[0278] Preferred polyethyleneimines are diethylenetriamine,
triethylenetetramine, tetraethylene-pentamine,
ethylenepropylenetriamine, trisaminopropylamine and higher
polyethyleneimines.
[0279] In a preferred embodiment, the polymeric polyamine is
selected from polyethyleneimines having a weight average molecular
weight of at least 300 g/mol.
[0280] Suitable polyethylenimines contain the following repeat
units
##STR00002##
wherein x is from 8 to 1500, preferably from 10 to 1000; y is from
0 to 10, preferably from 0 to 5, especially 0; z is 2+y.
[0281] Preferred polyethyleneimines are linear polyethyleneimines,
wherein x is from 8 to 1500, y is 0 and z is 2.
[0282] Preferred commercially available polyethylenimines are sold
by BASF SE under the trademark Lupasol.TM. and the Jeffamine
trademarks from Huntsman, particularly Lupasol.TM. PR8515.
[0283] In the processes according to the invention,
polyethyleneimines with a molecular weight of at least 500 g/mol,
preferably from 600 to 30 000 or 650 to 25 000 g/mol and in
particular from 700 to 5000 g/mol or 850 to 2500 g/mol, are
preferably used.
[0284] It is preferred to use the ratio of amine molar equivalents
(both primary and secondary) in the polyethyleneimine to Isocanates
molar equivalents contained in the isocyanate compound (A) or (A)
and (B) from 1.0:1.0 to 1.0:1.5, especially from 1.0:1.05 to
1.0:1.2.
[0285] The microcapsules obtained by the process according to the
invention, typically have core/shell ratios (w/w) from 20:1 to 1:1,
preferably from 5:1 to 2:1 and in particular from 4:1 to 3:1.
Step e)
[0286] The polyaddition reaction in step e) is generally performed
at a temperature of at least 50.degree. C., preferably 60.degree.
C., more preferably in a range of from 75.degree. C. to 90.degree.
C. and in particular 85.degree. C. to 90.degree. C., in order to
ensure sufficiently rapid reaction progress.
[0287] Here, it may be preferred to increase the temperature in
stages (e.g. in each case by 10.degree. C.) until the completion of
the reaction, the dispersion is cooled down to room temperature
(21.degree. C.).
[0288] The reaction time typically depends on the reaction amount
and temperature used. The period of time for the polyaddition
reaction is ranging from a few minutes to several hours. Usually,
microcapsule formation is established between ca. 60 minutes to 6 h
or up to 8 h at the temperatures defined above.
Step f)
[0289] According to the invention in step f) the addition of
hydroxyalkylcellulose to the dispersion obtained in step e) is
required.
[0290] In addition to hydroxyalkylcelluloses, the microcapsule
dispersion of the invention may comprise at least one stabilizing
agent which is different from hydroxyalkylcelluloses. Suitable
further stabilizing agents different from hydroxyalkylcelluloses
are described in the following.
[0291] The relation to hydroxyalkylcellulose the term "alkyl" is
preferably defined as linear or branched C.sub.1-C.sub.6 alkyl.
Examples of C.sub.1-C.sub.6-alkyl are CH.sub.3, C.sub.2H.sub.5,
n-propyl, CH(CH.sub.3).sub.2, n-butyl, CH(CH.sub.3)--C.sub.2H5,
CH.sub.2--CH(CH.sub.3).sub.2, C(CH.sub.3).sub.3, n-pentyl,
1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl,
1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl,
1-methyl pentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl,
1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl,
2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl,
1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl,
1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl or
1-ethyl-2-methylpropyl, preferably methyl, ethyl, n-propyl,
1-methylethyl, n-butyl, 1,1-dimethylethyl, n-pentyl or n-hexyl.
[0292] Examples of C.sub.2-C.sub.6-hydroxyalkyl groups are
2-hydroxyethyl, 2- and 3-hydroxypropyl, 1-hydroxyprop-2-yl, 3- and
4-hydroxybutyl, 1-hydroxybut-2-yl, 5-hydroxypentyl, 6-hydroxyhexyl.
Preferred is 2-hydroxyethyl.
[0293] Preferred is hydroxyalkylcellulose, wherein alkyl is a
C.sub.1-C.sub.4-alkyl, particularly hydroxyethylcellulose. Suitable
hydroxyalkylcelluloses can be prepared by alkoxylation of a
cellulose material by known methods. Thus, a cellulose can be
reacted with ethylene oxide and/propylene oxide. The amount of
alkylene oxide is preferably about 0.01 to 5 moles, more preferably
about 0.02 to 3.5 moles, especially 0.05 to 2.5 per mole of glucose
repeat units in the employed cellulose.
[0294] Preferably, the hydroxyalkylcellulose has a degree of
polymerization (DP) of 10 to 5000, preferably 20 to 3000, in
particular 30 to 1000.
[0295] Preferably, the hydroxyalkylcellulose has a degree of
substitution with respect to hydroxyalkyl groups (DS) of from 0.01
to 3, more preferably 0.02 to 2, especially 0.02 to 1.5.
[0296] Preferred commercially available hydroxyalkylcelluloses are
the Natrosol.TM. trademarks and especially preferred Natrosol.TM.
250 (CAS-Nr. 9004-62-0) of Herkules Incorporated.
[0297] In a particular embodiment of the invention, the amount of
hydroxyalkylcellulose employed in the dispersion is in the range
from 0.01% by weight to 1.2% by weight, more particularly in the
range from 0.01% by weight to 0.6% by weight, based on the total
weight of the dispersion.
[0298] Provided hydroxyalkylcellulose is employed as a stabilizing
agent, additional stabilizing agents may also be employed. Examples
of suitable additional stabilisation agents are starches, acrylate
homopolymers or acrylate copolymers.
[0299] Preferred commercially available starches are sold by
National starch, under the trademark National 465, Purity W or
starch B990.
[0300] Preferred commercially available acrylate polymers or
copolymers are sold by BASF SE under the trademark Tinovis CD,
Ultragel 300 and Rheocare TTA.
[0301] When additional stabilizing agents are employed, they may be
used in an amount of about 0.1% by weight to about 5.0% by weight,
particularly 0.5% by weight to 4% by weight and more particularly
1% to 3% by weight, based on the total weight of the
dispersion.
[0302] The stabilizing agent, in particular hydroxyalkylcellulose,
is preferably added to the dispersion once the microcapsules are
formed. It is not preferred to add the stabilizing agent, in
particular hydroxyalkylcellulose, during the formation of the
microcapsules.
[0303] In a special embodiment, the hydroxyalkylcellulose is added
to the microcapsule dispersion in combination with at least one
dispersion aid. Examples of suitable dispersion aids are alcohols,
polyols, mono- and dialkyether of polyols, oils and mixtures
thereof.
[0304] Suitable dispersion aids are alkylenglycoles,
alkylenglycolmono(C.sub.1-C.sub.4-alkyl)ethers,
alkylen-glycoldi(C.sub.1-C.sub.4-alkyl)ethers, polyalkylenglycoles,
polyalkylenglycolemono(C.sub.1-C.sub.4-alkyl)ethers,
polyalkylenglycoledi(C.sub.1-C.sub.4-alkyl)ethers and mixtures
thereof.
[0305] The dispersion aid is preferably selected from methanol,
ethanol, n-propanol, isopropanol, n-butanol, ethylenglycol,
ethylenglycolmono(C.sub.1-C.sub.4-alkyl)ethers,
ethylenglycoldi(C.sub.1-C.sub.4-alkyl)ethers, 1,2-propylenglycol,
1,2-propylenglycolmono(C.sub.1-C.sub.4-alkyl)ethers,
1,2-propylenglycoldi(C.sub.1-C.sub.4-alkyl) ethers, glycerin,
polyglycerines and mixtures thereof.
[0306] Preferred dispersion aids are glycerine or propandiol.
Step g)
[0307] A further aspect of the invention relates to microcapsules,
obtained by drying the aqueous dispersion of the defined
microcapsules.
[0308] The dispersion of the microcapsules obtained in step f) may
be dried in step g) by using techniques known in the art. For
example, the solid capsules can be isolated by filtration and
dryed. Drying of the isolated capsules may be performed by heating,
e.g. in an oven or by contact with a heated gas stream.
[0309] Preferably, drying of the dispersion is carried out by spray
drying or fluid-bed drying.
[0310] Spray drying techniques and apparatus are well known in the
art. A spray-drying process pushes suspended capsules through a
nozzle and into a drying chamber. The capsules may be entrained in
a fluid (such as air) that moves inside of a drying chamber. The
fluid (which may be heated, for example at a temperature of 150 and
120.degree. C., more preferably between 170.degree. C. and
200.degree. C., and still more preferably between 175.degree. C.
and 185.degree. C.) causes the liquid to evaporate, leaving behind
the dried capsules which can then be collected from the process
equipment and further processed.
[0311] It is conventional to mix spray dried capsules with flow
aids to produce a flowable powder that are not susceptible to
caking. Flow aids include silicas or silicates, such as
precipitated, fumed or colloidal silicas; starches; calcium
carbonate; sodium sulphate; modified cellulose; zeolites; or other
inorganic particulates known in the art.
[0312] It is quite common, given the high temperatures and
impaction forces encountered during a spray drying procedure, for
core shell capsules to lose some of their core material.
[0313] Furthermore, it may not be possible to work at sufficiently
high temperatures for a sufficiently long period of time to drive
off all moisture from the dispersion, without compromising the
thermal stability of the capsules. Accordingly, the polyurea
capsules emerging from a spray-drying process, as herein described,
may contain small amounts of surface oil as well as residual
moisture.
[0314] In general the obtained dried microcapsules are in the form
of a powder. Advantageously, these dried microcapsules can be
redispersed in water and have excellent properties like low
viscosity, good phase stability without any or low
agglomeration.
[0315] If the microcapsules of the present invention are intended
to be stored in the form of a dispersion, the pH of the dispersion
is adjusted to a level of about 5 to 10. This may be achieved with
the addition to an alkaline dispersion of a suitable acid, such as
citric acid or formic acid.
[0316] The microcapsule composition can be prepared continuously or
batchwise, preferably batchwise. In a further embodiment, the
dispersion of the microcapsules may contain non-encapsulated, i.e.
free lipophilc components, external of the capsules in the aqueous
dispersion.
[0317] It is likewise possible for the ingredients of the core to
migrate from the core of the microcapsules (i.e. the lipophilic
component and/or further materials present in the core) into the
shell.
[0318] In a further embodiment of the invention, the dispersion of
the microcapsules comprises at least one preservative in order to
prevent microbial contamination of the microcapsules. The
preservative may be encapsulated and/or it may be contained in the
aqueous suspending medium of the dispersion.
[0319] Suitable preservatives include quaternary compounds,
biguanide compounds, ethylhexylglycerin, caprylyl glycol, phenezhyl
alcohol, propandiol, undecyl alcohol, tocopherol and mixtures
thereof.
[0320] Non-limiting examples of quaternary compounds include
benzalkonium chlorides and/or substituted benzalkonium chlorides,
di(C.sub.6-C.sub.14)alkyl di short chain (C.sub.1-4 alkyl and/or
hydroxyalkl) quaternary, N-(3-chloroallyl) hexaminium chlorides,
benzethonium chloride, methylbenzethonium chloride, cetylpyridinium
chloride, diester quaternary ammonium compounds and mixtures
thereof.
[0321] Preferred commercially available benzalkonium chlorides are
sold by Lonza under the trademark Barquat.RTM., Maquat.RTM.
trademarks from Mason, Variquat.RTM. trademarks from Witco/Sherex
and Hyamine.RTM. trademarks from Lonza.
[0322] Preferred commercially available di(C.sub.6-C.sub.1a)alkyl
di short chain (C.sub.1-4 alkyl and/or hydroxyalkl) quaternary are
sold by Lonza under the trademark Bardac.RTM..
[0323] Preferred commercially available N-(3-chloroallyl)
hexaminium chlorides are sold by Dow under the trademark
Dowicide.RTM. and Dowicil.RTM..
[0324] Preferred commercially available benzethonium chlorides are
sold by Rohm & Haas under the trademark Hyamine.RTM..
[0325] Preferred commercially available methylbenzethonium
chlorides are sold by Rohm & Haas under the trademark
Hyamine.RTM. 10*.
[0326] Preferred commercially available cetylpyridinium chlorides
are sold by Merrell Labs under the trademark Cepacol chloride.
[0327] Examples of preferred dialkyl quaternary compounds are
di(C.sub.8-C.sub.12)dialkyl dimethyl ammonium chlorides.
[0328] Preferred commercially available dialkyl quaternary and
dioctyldimethylammonium chlorides are sold by Lonza under the
trademark Bardac.RTM. 22 and (Bardac.RTM. 2050).
[0329] The quaternary compounds useful as cationic preservatives
and/or antimicrobial agents herein are preferably selected from the
group consisting of dialkyldimethylammonium chlorides,
alkyldimethylbenzylammonium chlorides, dialkylmethylbenzylammonium
chlorides, and mixtures thereof. Other preferred cationic
antimicrobial actives useful herein include
diisobutylphenoxyethoxyethyl dimethylbenzylammonium chloride and
(methyl)diisobutylphenoxyethoxyethyl dimethylbenzylammonium
chloride (i.e. methylbenzethonium chloride). Preferred commercially
available quaternary compounds are sold by Rohm & Haas under
the trademark Hyamine.RTM. 1622.
[0330] Preferred commercially available preservatives are sold by
Schulke under the trademark Sensiva PA20.RTM., Sensiva PA40.RTM.,
Sensiva SC10.RTM., Sensiva SC50.RTM..
[0331] The microcapsules and dispersion of microcapsules as defined
above can be used in a large number of different applications,
depending on the type of lipophilic component.
[0332] A preferred embodiment of the invention is the use of the
aqueous dispersion of microcapsules or of microcapsules obtained by
the drying of the aqueous dispersion as defined in [0333] a
personal care composition or [0334] a composition used for
industrial or institutional or hospital disinfection or [0335] a
material protection composition or [0336] a pharmaceutical
composition or [0337] a plant protection composition or [0338] home
care products.
[0339] Especially preferred is the use in [0340] a cosmetic
composition or [0341] a hygiene composition or [0342] a composition
for industrial or institutional or hospital cleaning or
disinfection or [0343] laundry detergents, [0344] fabric softeners,
[0345] dishwashing liquids, [0346] household cleaners or [0347]
industrial cleaners.
[0348] Preference is given to the use of aqueous dispersion of the
microcapsules or of microcapsules obtained by drying the aqueous
dispersion for the finishing of all kind of nonwovens, like wipes
(for example wet wipes or dry wipes for cosmetic or cleaning
purposes), but also for finishing papers (including wallpapers,
toilet paper or papers for books and newsletters), for finishing
diapers or sanitary napkins and similar hygienic products or
textiles, e.g. in order to finish the papers or textiles with a dye
or an insecticide, or in cosmetic compositions, e.g. for producing
sunscreen compositions which comprise the UV filter in the form of
the microcapsules. Another use pertains to finishing diapers or
sanitary napkins and similar hygienic products. Furthermore the
microcapsules may be used in massage oils or cremes or personal
lubricants, and suppositories, e.g. to provide this products with
antiinflammatory actives.
[0349] A preferred embodiment of the invention is the use of the
microcapsules or of microcapsules dispersion according to the
invention in finishing of textiles, papers or nonwovens.
EXAMPLES
[0350] The following examples are intented to further illustrate
the present invention without limiting its scope in any way.
Analytics:
[0351] The volume average particle size is measured by light
scattering measurements using a Malvern 2000S instrument and the
Mie scattering theory, e.g. Mictrotrac nanotrac 250.
[0352] Young's modulus (E-Modulus) and Nominal rupture stress are
described above. In Particular, in order to get quantitative
mechanical information of the microcapsule surface the Peak-Force
Quantitative Nano-Mechanics mode (PF-QNM) is used.
Ingredients:
[0353] polyvinylpyrrolidone having a K value of 90 (PVP Kolloidon
90.RTM. by BASF SE) [0354] caprylic/capric triglyceride
(Myritol.RTM. 318 by BasF SE) [0355] dicyclohexylmethane
diisocyanate (Desmodur.RTM. W) [0356] anionic HDI oligomer
(Bayhydur.RTM. XP 2547 by Bayer Material Science) [0357]
polyethyleneimine (Lupasol.RTM. PR8515 by BASF SE) [0358]
hydroxyethylcellulose (Natrosol.RTM. 250 by Herkules)
Preparation:
Example 1. (with the Ratio of Capsule Shell to Capsule Diameter
<0.7)
[0359] A premix(I) was prepared from 25 g of polyvinylpyrrolidon
having a K value of 90 (PVP Kolloidon 90) and 860 g of water and
adjusted to a pH of 10.0 using aqueous sodium hydroxide solution
(5% strength by weight). Premix II was prepared from 300 g of
caprylic/capric triglyceride (Myritol.RTM. 318), 23.8 g of
dicyclohexylmethane diisocyanate (Desmodur.RTM. W) and 6.6 g of
anionic HDI oligomer (Bayhydur.RTM. XP 2547). These two premixes
were combined and emulsified with the help of a Mig stirrer at room
temperature and a speed of 800 rpm until the desired capsule size
was achieved monitored with a Malvern Autosizer. The pH of the
emulsion was then adjusted to 8.5 using aqueous sodium hydroxide
solution (5% strength by weight). Then, at room temperature and
with stirring at 800 rpm, a solution of 12 g of polyethyleneimine
(Lupasol.RTM. PR8515) in 22.6 g of water was added over the course
of 1 minute. The reaction mixture was then subjected to the
following temperature program: heating to 60.degree. C. in 60
minutes, maintaining this temperature for 60 minutes, then 60
minutes at 70.degree. C., 60 minutes at 80.degree. C. and finally
60 minutes at 85.degree. C. Finally, 5 g of hydroxyethylcellulose
(Natrosol.RTM. 250) was added at once. The mixture was then cooled
to room temperature, giving the desired microcapsule dispersion
with volume particle size distribution according to the following
values: d 50=40 .mu.m and d 90=78 .mu.m.
shell weight capsule diameter = 0.45 ##EQU00001##
[0360] Young's modulus: .about.100 MPa
[0361] Nominal rupture stress: 0.1-0.5 MPa
Example 2. (with the Ratio of Capsule Shell to Capsule Diameter
<0.7)
[0362] A premix(I) was prepared from 25 g of polyvinylpyrrolidon
having a K value of 90 (PVP Kolloidon 90.RTM.) and 870.4 g of water
and adjusted to a pH of 10.0 using aqueous sodium hydroxide
solution (5% strength by weight). Premix II was prepared from 300 g
of caprylic/capric triglyceride (Myritol.RTM. 318), 19.9 g of
dicyclohexylmethane diisocyanate (Desmodur.RTM. W) and 5.5 g of
anionic HDI oligomer (Bayhydur.RTM. XP 2547). These two premixes
were combined and emulsified with the help of a Mig stirrer at room
temperature and a speed of 400 rpm until the desired capsule size
was achieved. The pH of the emulsion was then adjusted to 8.5 using
aqueous sodium hydroxide solution (5% strength by weight). Then, at
room temperature and with stirring at 800 rpm, a solution of 10.2 g
of polyethyleneimine (Lupasol.RTM. PR8515) in 19 g of water was
added over the course of 1 minute. The reaction mixture was then
subjected to the following temperature program: heating to
60.degree. C. in 60 minutes, maintaining this temperature for 60
minutes, then 60 minutes at 70.degree. C., 60 minutes at 80.degree.
C. and finally 60 minutes at 85.degree. C. Finally, 5 g of
hydroxyethylcellulose (Natrosol.RTM. 250) was added at once. The
mixture was then cooled to room temperature, giving the desired
microcapsule dispersion with the volume particle size distribution
according to the following values: d 50=33 .mu.m and d 90=56
.mu.m.
shell weight capsule diameter = 0.5 ##EQU00002##
[0363] Young's modulus: .about.30 MPa
[0364] Nominal rupture stress: <0.2
Example 3 and 4 and Comparative Examples
[0365] According to example 1 dispersions of microcapsules were
prepared, but with different stabilizing agents in step (f). As
shown in table 1 the use of hydroxyethylcellulsose alone or in
mixture with a second stabilizing agent give microcapsule
dispersion with a better stability (lower phase separation after 2
weeks according to example 1, 3 and 4 in comparison to the examples
without hyroxyethylcellulose)
TABLE-US-00001 stabilizing agent in Amount Phase separation after 2
step (f) tested [%].sup.1) weeks at 50.degree. C.[%].sup.2)
Rheocare .RTM.XG 3.0 >20 Rheocare .RTM. TTA 3.0 >20 Luvigel
.RTM.Fit 3.0 >20 Tinovis .RTM.ADE 3.0 >20 Luvigel Star .RTM.
3.0 >20 Tinovis .RTM. CD 3.0 >10 Cosmedia-Triple-C .RTM. 3.0
>20 Cosmedia-SP .RTM. 3.0 >20 Purity W .RTM. 3.0 10 Starch
B990 .RTM. 3.0 10 National 465 .RTM. 3.0 10 Natrasol .RTM.250 0.4
<5 (Example 1) Natrosol .RTM.250 with 0.2:1.5 <5 Cosmedia
Triple C .RTM. (Example 3) Natrosol 250 .RTM.with 0.2:1.5 <5
Purity W .RTM. (Example 4) .sup.1)Percentage by weight
.sup.2)Stabilization was measured by naked eye assessment and was
expressed as the ratio of the height of the water phase to the
total height of the slurry
[0366] Stabilizing agents in step (f)
TABLE-US-00002 Rheocare .RTM. XG Xanthan gum Rheocare .RTM. TTA
Acrylates Copolymer Luvigel .RTM. Fit Acrylates/C10-C30 Alkyl
Methacrylate Copolymer Tinovis .RTM. ADE Sodium acrylates copolymer
(and) hydrogenated polydecene (and) PPG-1 Trideceth-6 Luvigel .RTM.
Star Polyurethane-39 Tinovis .RTM. CD
Dimethylacrylamide/Ethyltrimonium chloride Methacrylate Copolymer
(and) Propylene glycol dicaprylate/dicaprate (and) PPG-1
Trideceth-6 (and) C10-C11 Isoparaffin Cosmedia .RTM. Triple C
Polyquaternium-37 (and) Dicaprylyl Carbonate (and) Lauryl Glucoside
Cosmedia .RTM. SP Sodium polyacrylate Purity .RTM. W modified
starch Starch .RTM. B990 modified starch National .RTM. 465
modified starch Natrosol .RTM. 250 HR hydroxyethyl cellulose by
Herkules
* * * * *