U.S. patent application number 09/308642 was filed with the patent office on 2001-10-11 for disintegrating particles and cleanser or detergent composition.
Invention is credited to HANAZAWA, HIDEYUKI, HASEBE, YOSHIHIRO, MATSUMOTO, TATSUKI, MEIWA, ZENBEI, NAKAMURA, MAMORU, YAMAZAKI, RITSUKO.
Application Number | 20010029243 09/308642 |
Document ID | / |
Family ID | 17393355 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010029243 |
Kind Code |
A1 |
MEIWA, ZENBEI ; et
al. |
October 11, 2001 |
DISINTEGRATING PARTICLES AND CLEANSER OR DETERGENT COMPOSITION
Abstract
The invention relates to disintegrating particles formed by
agglomerating primary particles at least part of which are
insoluble in water, wherein the agglomeration of the disintegrating
particles is disintegrated in an aqueous solution containing a
water-soluble salt by lowering the concentration of the
water-soluble salt. The invention also relates to a cleanser or
detergent composition that includes the disintegrating particles, a
water-soluble salt at a concentration lower than its saturated
solubility, a surfactant and water. The composition has excellent
physical (mechanical) cleanability and stability with time and
gives users a pleasant feeling upon use. The composition does not
cause damage to and itch on the skin because the disintegrating
particles are disintegrated during cleansing and rinsing, and it is
extremely good in rinsability.
Inventors: |
MEIWA, ZENBEI; (WAKAYAMA,
JP) ; NAKAMURA, MAMORU; (WAKAYAMA, JP) ;
MATSUMOTO, TATSUKI; (WAKAYAMA, JP) ; HASEBE,
YOSHIHIRO; (WAKAYAMA, JP) ; HANAZAWA, HIDEYUKI;
(TOKYO, JP) ; YAMAZAKI, RITSUKO; (TOKYO,
JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT
1755 JEFFERSON DAVIS HIGHWAY
FOURTH FLOOR
ARLINGTON
VA
22202
|
Family ID: |
17393355 |
Appl. No.: |
09/308642 |
Filed: |
May 28, 1999 |
PCT Filed: |
September 25, 1998 |
PCT NO: |
PCT/JP98/04294 |
Current U.S.
Class: |
510/130 |
Current CPC
Class: |
A61K 8/0204 20130101;
C11D 3/046 20130101; C11D 3/08 20130101; A61K 8/0275 20130101; C11D
3/3703 20130101; C11D 3/37 20130101; A61Q 19/10 20130101; C11D 3/10
20130101; C11D 3/06 20130101; C11D 17/06 20130101; C11D 3/126
20130101; A61K 2800/28 20130101 |
Class at
Publication: |
510/130 |
International
Class: |
A61K 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 1997 |
JP |
9-263718 |
Claims
1. A disintegrating particle, comprising: an agglomerate of primary
particles, wherein at least a portion of the primary particles are
insoluble in water and wherein the disintegrating particle is
disintegrated in an aqueous solution containing a water-soluble
salt by lowering the concentration of the water-soluble salt.
2. The disintegrating particle of claim 1, wherein the primary
particles are water-insoluble or contain a mixture of
water-insoluble particles and water-soluble particles.
3. The disintegrating particle of claim 1, wherein the agglomerate
of primary particles comprises the primary particles bonded to one
another by a water-soluble binder.
4. The disintegrating particle of claim 1, which has an average
particle diameter of 100 to 800 .mu.m.
5. The disintegrating particle of claim 1, wherein the average
particle diameter of the primary particles is at most 70 .mu.m.
6. The disintegrating particle of claim 3, wherein the content of
the water-soluble binder is 0.5 to 30 wt. % based on the weight of
the primary particles.
7. The disintegrating particle of claim 1, wherein at least a
portion of the disintegrating particles are disintegrated in an
aqueous solution containing the water-soluble salt at a
concentration lower than 1.5 wt. %.
8. The disintegrating particle of claim 7, wherein the
disintegrating particles are disintegrated in an aqueous solution
containing the water-soluble salt at a concentration lower than 1.5
wt. % into particles having an average particle diameter of at most
80 .mu.m or smaller, and a rate of disintegration is at least 60
vol. %.
9. The disintegrating particle of claim 7, wherein said
concentration is 1.0 wt % or less.
10. The disintegrating particle of claim 8, wherein said
concentration is 1.0 wt % or less.
11. A cleanser or detergent composition comprising the
disintegrating particle of claim 1, a water-soluble salt, a
surfactant and water, wherein the concentration of the
water-soluble salt is lower than its saturated solubility.
12. The composition of claim 11, wherein the water-soluble salt is
an inorganic salt, and the inorganic salt is present at a
concentration of from 1.5 wt. % to less than the saturated
solubility of the inorganic salt.
13. The composition of claim 12, wherein said concentration is 1.0
wt % to less than the saturated solubility.
14. The composition of claim 11, which comprises 1 to 25 wt. % of
the disintegrating particles.
15. The composition of claim 11, wherein at least a portion of the
disintegrating particles disintegrate during the cleansing and
rinsing of an object.
16. The composition of claim 11, wherein at least a portion of the
disintegrating particles disintegrate during the cleansing and
rinsing of an object, and the rate of disintegration to particles
having an average particle diameter of 80 .mu.m or smaller is at
least 60 vol. %, based on the total volume of the disintegrating
particles.
17. A method of cleaning an object, comprising contacting the
object with the composition of claim 11, followed by rinsing.
18. The method of claim 17, wherein the object is human skin.
Description
TECHNICAL FIELD
[0001] The present invention relates to disintegrating particles
and a cleaner or detergent composition containing the same, and
more particularly to disintegrating particles which disintegrate
during cleansing and rinsing, thereby causing little damage to and
itchiness of the skin. A cleanser or detergent composition which
contains the disintegrating particles has outstanding physical
(mechanical) cleaning capability, and has excellent rinsability
properties because the particles readily disintegrate during
rinsing.
BACKGROUND ART
[0002] In recent years, various kinds of rinse-out type skin
cleansers (facial soap, body soap, massaging cream and solid soap)
have been marketed and used. The reasons for the success of these
products is that they provide users with a fresh clean feeling
after use and moreover have the desirable property that excess
keratin (dirt), clogged skin pores, and the like, which are
difficult to remove with the conventional cleanser compositions,
can be washed out by virtue of the physical cleansing effects of
the rinse-out type skin cleansers.
[0003] Controlling the particle diameter and hardness of a
scrubbing cleanser in view of problems of irritation to the skin
and skin roughness has also been investigated, in order to develop
a cleanser having high cleanability that causes little skin
irritation (Japanese Patent Application Laid-Open No.
151693/1990).
[0004] On the other hand, cleanser compositions have been proposed
to achieve high physical detergency and to smoothly finish the skin
by incorporating particles of sodium chloride in a proportion not
lower than its saturated solubility in the cleanser composition
(Japanese Patent Application Laid-Open No. 305951/1994). Other
cleanser compositions have been proposed that are intended to
achieve high physical detergency and to smoothly finish the skin by
incorporating particles of a water-soluble inorganic salt in the
cleanser composition and dissolving potassium chloride and
magnesium chloride therein with the object of stabilizing the
resulting dispersion (Japanese Patent Application Laid-Open No.
208455/1996).
[0005] However, the cleanser compositions comprising the scrubbing
cleanser wherein the particle diameter and hardness have been
controlled still have problems because they leave a feeling of
mixed foreign matter upon massaging, and it is difficult to rinse
out afterwards.
[0006] The cleanser composition in which the particles of sodium
chloride are incorporated in a proportion not lower than its
saturated solubility have the problems of dispersion stability and
dispersibility of individual components including the scrubbing
cleanser (scrubber), since the scrubber tends to cause
agglomeration and sedimentation. In addition, since sodium chloride
is incorporated in a proportion not lower than its saturated
solubility, the composition is undesirable because its foamability
is extremely reduced upon cleansing, and so its cleaning ability
and skin feeling are deteriorated.
[0007] On the other hand, in the cleanser composition in which
potassium chloride and magnesium chloride are incorporated in
addition to the above-described particles of the water-soluble
inorganic salt, the agglomeration and sedimentation of the scrubber
are improved. However, since the water-soluble inorganic salt is
incorporated in a proportion not lower than its saturated
solubility, the composition undesirably has a reduced foamability
upon cleansing and so its cleaning ability and skin feel are
deteriorated.
DISCLOSURE OF THE INVENTION
[0008] One object of the invention is to provide a cleansing
composition having high detergency and gives users a pleasant
feeling upon use. Another object is to provide a cleansing
composition that does not cause damage to and itch on the skin.
Another object of the present invention is to provide a cleansing
composition having extremely good rinsability because the
disintegrating particles are easily disintegrated by either rinse
or tears.
[0009] These and other objects are achieved by providing
disintegrating particles formed by agglomerating primary particles
at least part of which are insoluble in water (hereinafter referred
to as "disintegrating particles"), wherein the agglomeration of the
disintegrating particles disintegrates in an aqueous solution
containing a water-soluble salt by lowering the concentration of
the water-soluble salt.
[0010] According to the present invention, there is also provided a
cleanser composition that contains the disintegrating particles, a
water-soluble salt, a surfactant and water, wherein the
concentration of the water-soluble salt is lower than its saturated
solubility.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] Other features of the invention will become apparent in the
following description of preferred embodiments, which are given for
illustration of the invention and are not intended to be limiting
thereof.
[0012] The disintegrating, particles according to the present
invention are agglomerated particles formed by agglomerating
primary particles at least part of which are insoluble in water,
and are such that the agglomeration thereof is disintegrated in an
aqueous solution containing a water-soluble salt by lowering in the
concentration of the water-soluble salt, namely their rate of
disintegration is higher in the case where the concentration of the
water-soluble salt is low compared with the case where the
concentration is high.
[0013] No particular limitation is imposed on the primary particles
for forming the disintegrating particles according to the present
invention so far as at least a portion of the particles is
insoluble in water. Preferable examples thereof include
water-insoluble primary particles and a combination of
water-insoluble primary particles and water-soluble primary
particles. These primary particles may be either organic particles
or inorganic particles. The term "water-insoluble" as used herein
means that the solubility of the subject particles is lower than 50
wt. %, when 1 part by weight of the particles are dissolved in 99
parts by weight of water, while the term "water-soluble" means that
the solubility under the same conditions as described above is at
least 50 wt. %. Preferably, the solubility is calculated out from a
solids content in a filtrate obtained by filtering the aqueous
solution through filter paper (No. 2). The water-soluble primary
particles are preferably those such that the solubility is at least
90 wt. %.
[0014] Examples of the water-insoluble organic primary particles
include primary particles of synthetic polymers, such as
polyethylene, polypropylene, polyamide, polyethylene terephthalate,
polystyrene, polyurethane, sodium poly(meth)acrylate,
poly(meth)acrylic esters, rubbers such as ethylene rubber,
propylene rubber, styrenebutadiene rubber, butadiene rubber and
silicone rubber, and crosslinked products thereof; and natural
polymers such as cellulose and derivatives thereof, chitosan and
derivatives thereof, starch and fruit shells, and derivatives
thereof. Among these, the primary particles of polyethylene,
polyamide, polystyrene, sodium poly(meth)acrylate,
poly(meth)acrylic esters, cellulose and derivatives thereof, and
starch are preferably used.
[0015] Examples of the water-insoluble primary particles include
primary particles of bentonite, talc, mica, kaolin, sepiolite,
silica, calcium carbonate, titanium oxide, silicic acid anhydride,
hydroxy calcium apatite and pearl powder. Among these, bentonite,
talc, mica, kaolin and silica are preferably used.
[0016] These water-insoluble primary particles may be in any form
of true sphere, substantial sphere and irregular shapes formed by
grinding or the like. Hollow or porous particles may also be used.
These water-insoluble primary particles may be used either singly
or in any combination thereof.
[0017] As the water-soluble organic primary particles, there may be
used primary particles of synthetic products such as polyvinyl
alcohol and derivatives thereof, alkali salts of poly(meth)acrylic
acid, alkali salts of (meth)acrylic acid/(meth)acrylate copolymers,
alkali salts of acrylic acid/maleic acid copolymers, and polyvinyl
pyrrolidone; semisynthetic products such as methyl cellulose, ethyl
cellulose, sodium carboxymethyl cellulose, hydroxyalkyl cellulose
and modified starch (hydroxyalkyl-modified starch,
phosphate-modified starch, etc.); and natural products such as
starch, sucrose, lactose, seaweeds and proteins.
[0018] Examples of the water-soluble inorganic primary particles
include primary particles of chlorides such as sodium chloride,
potassium chloride and magnesium chloride; sulfates such as sodium
sulfate, potassium sulfate, magnesium sulfate and aluminum sulfate;
and carbonates such as sodium carbonate and sodium
hydrogencarbonate. As the sodium chloride, may be used common salt
generally sold, highly purified salt, natural salt and the like.
Among these, sodium chloride, potassium chloride, magnesium
chloride and sodium carbonate are preferred.
[0019] The form of these water-soluble primary particles is also
not limited, and they may be used either singly or in any
combination thereof.
[0020] The weight ratio of the water-insoluble primary particles to
the water-soluble primary particles in the disintegrating particles
according to the present invention is preferably within a range of
from 1/99 to 100/0, more preferably 50/50 to 100/0.
[0021] The average particle diameter of these primary particles is
preferably 70 .mu.m or smaller, more preferably 60 .mu.m, and most
preferably 50 .mu.m or smaller. The fact that the average particle
diameter of the primary particles falls within this limit is
preferred in that the primary particles give users no feeling of
physical disorder and have good rinsability when the disintegrating
particles are disintegrated during cleansing of an object to be
cleaned or by rinse and tears. The size is measure according to
ordinary methods.
[0022] The average particle diameter of the disintegrating
particles according to the present invention is preferably within a
range of from 100 .mu.m to 800 .mu.m, more preferably from 125
.mu.m to 600 .mu.m, most preferably from 150 .mu.m to 360 .mu.m.
The fact that the average particle diameter of the disintegrating
particles falls within the range of from 100 .mu.m to 800 .mu.m is
preferred in that the resulting cleanser composition give users a
particularly little feeling of physical disorder upon use and has
very low irritativeness to the skin. The size is measured according
to ordinary methods.
[0023] The disintegrating particles according to the present
invention are desirably such that the above-described primary
particles are bonded to one another into agglomerates by a
water-soluble binder.
[0024] No particular limitation is imposed on such a water-soluble
binder so far as it is dissolved in an aqueous solution of a
water-soluble salt when the salt concentration of the aqueous
solution is lowered and deposited when the salt concentration is
raised. However, synthetic products such as polyvinyl alcohol and
derivatives thereof (for example, itaconic acid-modified polyvinyl
alcohol), sulfonic acid-modified polyvinyl alcohol and maleic
acid-modified alcohol, alkali salts of poly(meth)acrylic acid,
alkali salts of (meth)acrylic acid/(meth)acrylate copolymers,
alkali salts of acrylic acid/ maleic acid copolymers, and polyvinyl
pyrrolidone; semisynthetic products such as methyl cellulose, ethyl
cellulose, sodium carboxymethyl cellulose, hydroxyalkyl cellulose
and starch derivatives; and natural polymers such as starch,
seaweeds, sticky materials of plants and proteins are used.
[0025] In the disintegrating particles according to the present
invention, materials used for the water-soluble primary particles
and the water-soluble binder may be the same or different from each
other.
[0026] It is preferable that the water-soluble binder should be
used in a proportion of from 0.5 wt. % to 30 wt. % more preferably
0.75-25 wt. %, and most preferably 1-10 wt. %, based on the weight
of the primary particles, from the viewpoints of easy
disintegration of the resulting disintegrating particles and
operating characteristics upon the preparation of the
disintegrating particles or the cleanser composition containing the
particles.
[0027] No particular limitation is imposed on the preparation
process of the disintegrating particles according to the present
invention. However, the disintegrating particles are preferably
prepared, for example, either by mixing the primary particles and
the water-soluble binder and granulating the resultant mixture in
accordance with a granulation process such as rolling granulation,
rolling fluidized granulation, fluidized bed granulation, agitated
rolling granulation, melt granulation, extrusion granulation or
spray granulation, or a coating process such as spray drying, or by
granulating the primary particles in accordance with such a
granulation or coating process while mixing the primary particles
with the water-soluble binder.
[0028] As described above, the thus-obtained disintegrating
particles according to the present invention has a feature that the
rate of disintegration thereof in an aqueous solution containing
the water-soluble salt becomes higher as the concentration of the
water-soluble salt is lowered. Accordingly, when the disintegrating
particles are incorporated in a cleanser composition, the
disintegrating particles are stably dispersed in the cleanser
composition without being, disintegrated, but they are
disintegrated as the concentration of the water-soluble salt is
lowered during cleansing and rinsing. Taking such incorporation
into the cleanser composition into consideration, it is preferable
that the disintegrating characteristics of the disintegrating
particles according to the present invention should be designed in
such a manner that at least part of the particles are disintegrated
in an aqueous solution containing the water-soluble salt at a
concentration lower than 1.0 wt. %, preferably lower than 1.5 wt.
%. It is more preferable from the viewpoint of rinsability in rinse
and tears that the disintegrating characteristics should be
designed in such a manner that at least 60 vol. % preferably 70%,
and more preferably 80% of the particles are disintegrated in an
aqueous solution containing the water-soluble salt at a
concentration lower than 1.0 wt. %, preferably lower than 1.5 wt.
%. It is also preferable that the particles disintegrated at this
time should be reduced to an average particle diameter of 80 .mu.m
or smaller, more preferably 70 .mu.m, most preferably 65 .mu.m or
smaller.
[0029] The cleanser composition according to the present invention
comprises the above-described disintegrating particles, a
water-soluble salt, a surfactant and water, wherein the
concentration of the water-soluble salt is lower than its saturated
solubility.
[0030] The amount of the disintegrating particles incorporated into
the cleanser composition according to the present invention is
preferably 1 to 25 wt. %, particularly 2 to 20 wt. % and more
preferably 2-15 wt. % from the viewpoints of a feeling upon use and
physical (mechanical) cleanability.
[0031] The water-soluble salt used in the cleanser composition
according to the present invention includes water-soluble inorganic
salts and water-soluble organic salts. However, the water-soluble
inorganic salts are preferred.
[0032] Examples of the water-soluble inorganic salts include
chlorides such as sodium chloride, potassium chloride and magnesium
chloride; sulfates such as sodium sulfate, potassium sulfate,
magnesium sulfate and aluminum sulfate; and carbonates such as
sodium carbonate and sodium hydrogencarbonate. As the sodium
chloride, may be used common salt generally sold, highly purified
salt, natural salt and the like. Among these, sodium chloride,
potassium chloride, magnesium chloride and sodium carbonate are
particularly preferably used.
[0033] Examples of the water-soluble organic salts include acid
salts such as citric acid salt, succinic acid salt, maleic acid
salt, fumaric acid salt and malic acid salt, as well as anionic
surfactants such as various kinds of fatty acid soap, ester type
phosphates, acylated amino acid salts, sulfosuccinates and taurate
type surfactants. These organic salts may preferably be used in
combination with the water-soluble inorganic salt. In this case, a
weight ratio of the water-soluble inorganic salt to the
water-soluble organic salt is preferably within a range of from
100/0 to 5/95, more preferably 90/10 to 5/95 and most preferably
50/50 to 5/95.
[0034] Preferably, the amount of these water-soluble salts
incorporated is less than their saturated solubility in water in
the cleanser composition. However, from the viewpoints of
disintegrating characteristics by rinse and tears and foamability
of the resulting cleanser composition, the salts are preferably
incorporated in an amount of from at least 1.0 wt. % to less than
the saturated solubility, more preferably from at least 1.5 wt. %
to less than the saturated solubility, particularly from at least
2.0 wt. % to at most 0.8 times of the saturated solubility.
[0035] No particular limitation is imposed on the surfactant used
in the cleanser composition according to the present invention.
However, examples of a main surfactant include anionic surfactants
such as various kinds of fatty acid soap, phosphoric esters,
acylated amino acids, sulfosuccinic acids, taurate type surfactants
and polyoxyethylene alkyl sulfates; and nonionic surfactants such
as alkylsacchrides and ethylene oxide-added surfactants. Among
these, the phosphoric esters, acylated amino acids and
alkylsaccharides are preferred because of their low imitativeness
to the skin.
[0036] Incidentally, the surfactants and water-soluble organic
salts used in the cleanser composition according to the present
invention overlap each other. Any ionic surfactant which functions
as a salt may also be used as the water-soluble salt.
[0037] No particular limitation is imposed on the amount of such a
main surfactant incorporated. However, it is preferable that the
surfactant should be incorporated in an amount of 60 to 90 wt. %
when the cleanser composition is in the form of solid, 40 to 70 wt.
% in the form of paste, 40 to 70 wt. % in the form of gel, or 10 to
50 wt. % in the form of liquid.
[0038] Further, an amine oxide or imidazoline type surfactant may
also be preferably used as a foamability improver in addition to
the main surfactant.
[0039] Besides the above-described components, ingredients commonly
used in the classical cleanser or detergent compositions, for
example, oily substances, thickeners, wetting agents, colorants,
touch improvers, perfume bases, antiphlogistics, germicides,
ultraviolet absorbents and the like, may be used so far as no
detrimental influence is thereby imposed on the effects of the
present invention.
[0040] The cleanser compositions according to the present invention
can be widely used, for example, as skin cleansers such as facial
soap, body soap and solid soap, shampoos, tableware detergents,
contact lens detergent, tooth paste, massage cream and the
like.
EXAMPLES
[0041] Having generally described this invention, a further
understanding can be obtained by reference to certain specific
examples which are provided herein for purposed of illustration
only and are not intended to be limiting unless otherwise
specified.
[0042] In the following examples, all the designations of "part" or
"parts" mean part or parts by weight.
Preparation Example 1 of Disintegrating Particles
[0043] After kaolin (200 g; product of Wako Pure Chemical
Industries, Ltd.) was charged as primary particles into an
LFS-GS-2J type high-speed mixer (manufactured by Fukae Kogyo K.K.)
and premixed, FT-3 (sodium carboxymethyl cellulose, M/C.sub.6=0.9;
40 g; product of Nippon Paper Co., Ltd.) containing 5% of an active
ingredient was gradually added as a binder to conduct granulation.
The thus obtained granules were dried at 70.degree. C. for 24 hours
and sifted to obtain 45 g of Disintegrating Particles (1) having an
average particle diameter of 350 .mu.m.
Preparation Examples 2 to 5 of Disintegrating Particles
[0044] Disintegrating Particles (2) to (5) were produced in the
same manner as in Preparation Example 1 of Disintegrating Particles
except that the kinds and amounts of the primary particles and
binder used in Preparation Example 1 were changed as shown in Table
1. Incidentally, "Amount" shown in Table 1 is based on the weight
of each active ingredient.
Preparation Example 6 of Disintegrating Particle
[0045] UCN-5170D (polyurethane beads; 100 g; product of
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) and ground
sucrose (100 g; product of Wako Pure Chemical Industries, Ltd.)
were charged as primary particles into a SPRAY DRYER SD-1
(manufactured by EYELA Co.), and 5% HPC (hydroxypropyl cellulose;
800 g; product of Wako Pure Chemical Industries, Ltd.) was
gradually added thereto to spray dry the resultant mixture. The
thus-obtained particles were dried further for 24 hours at
70.degree. C. and sifted to obtain 56 g of Disintegrating Particles
(6) having an average particle diameter of 400 .mu.m.
[0046] Test Example
[0047] The average particle diameters and rates of disintegration
in water or a salt solution of the disintegrating particles
obtained in the preparation examples were measured. The results are
shown in Table 1.
[0048] (1) Measuring method of average particle diameter:
[0049] The measurement was conducted by means of a laser
diffraction/scattering type particle size distribution meter LA-910
(manufactured by Horiba Ltd.). A median diameter was used as the
average particle diameter.
[0050] (2) Measuring method of the rate of disintegration of
disintegrating particles:
[0051] (Rate of disintegration in purified water, A (%); Rate of
disintegration in 10% saline solution, B (%))
[0052] Each sample (0.3 g) of the disintegrating particles was
added to purified water (29.7 g) and stored for 15 hours in a
thermostatic chamber controlled to 35.degree. C. This specimen was
weighed out by 6 g on synthetic leather, and the synthetic leather
was massaged with one hand for 1 second (one stroke). Thereafter,
the particle diameter of the disintegrating particle sample was
measured by means of the laser diffraction/scattering type particle
size distribution meter LA-910. The amount of disintegrating
particles disintegrated to 80 .mu.m or smaller at this time was
expressed in terms of percentage by volume and regarded as the rate
of disintegration in purified water, A (%).
[0053] The same procedure was conducted with a 10% saline solution
to determine the rate of disintegration in 10% saline solution, B
(%).
1TABLE 1 Particle Rate of Rate of Preparation of Primary particles
diameter of disintegration disintegration in Example of Particle
Binder disintegrating in purified 10% saline disintegrating
diameter Amount*.sup.1 Amount*.sup.2 particles water, A solution, B
particles Kind (.mu.m) (wt. %) Kind (wt. %) (.mu.m) (%) (%) (1)
Kaolin 5 100 FT-3 1 150 91.7 22.9 (2) W-400G 30 100 KM-118 10 300
76.4 9.2 (3) W-400G 30 75 GL-05 20 350 62.6 6.8 PE-1080 8 25 (4)
W-400G 30 25 KM-118 5 200 88.0 18.2 Sodium Chloride 21 75 (5)
Acrylic beads 9 80 Starch A-55 8 300 80.5 12.1 Starch A-55 34 20
(6) UCN-517OD 7 50 HPC 20 400 68.3 7.5 Sucrose 24 50
*.sup.1Blending proportion in primary particles. *.sup.2[(Weight of
binder)/(weight of primary particles)] .times. 100.
[0054] In the table above, the following definitions apply.
[0055] Kaolin: Product of Wako Pure Chemical Industries, Ltd.
[0056] W-400G: Cellulose powder, product of Nippon Paper Co.,
Ltd.
[0057] PE-1080: Polyethylene beads, product of Sumitomo Seika
K.K.
[0058] Sodium chloride: Product of Naikai Engyo Co., Ltd.
(guaranteed product).
[0059] Acrylic beads: Lauryl acrylate/divinylbenzene 97/7,
synthesized product.
[0060] Starch A-55: Solfarex A-55, product of Matsutani Kagaku
Kogyo Co., Ltd.
[0061] UCN-5170D: Fine powder of crosslinked urethane, product of
Dainichiseika Color & Chemicals Mfg. Co., Ltd.
[0062] Sucrose: Product of Wako Pure Chemical Industries, Ltd.
[0063] FT-3: Sodium carboxymethyl cellulose, product of Nippon
Paper Co., Ltd.
[0064] HPC: Hydroxypropyl cellulose, product of Wako Pure Chemical
Industries, Ltd.
[0065] KM-118: Polyvinyl alcohol, product of Kuraray Co., Ltd.
[0066] GL-05: Polyvinyl alcohol, product of The Nippon Synthetic
Chemical Industry Co., Ltd.
[0067] As is apparent from Table 1, it is understood that in the
disintegrating particles according to the present invention, their
rates of disintegration in an aqueous solution containing a
water-soluble salt is increased in the case where the concentration
of the water-soluble salt is low compared to the case where the
concentration is high.
Examples 1 to 7 and Comparative Examples 1 to 3
[0068] Disintegrating Particles (1) to (6), silica powder (average
particle diameter: 210 .mu.m) and CL-5007 (polyethylene beads,
product of Sumitomo Seika K.K.; average particle diameter: 360
.mu.m) were separately incorporated to prepare cleanser
compositions having their corresponding formulations shown in Table
2. These cleanser compositions according to Examples 1 to 7 and
Comparative Examples 1 to 3 were separately used to evaluate their
rate of disintegration C, stability to incorporation, cleansing
effect, foamability, feeling upon use (massaging effect), itch on
the skin and rinsability in accordance with the following
respective evaluation methods. The results are shown in Table
3.
[0069] (a) Rate of disintegration of disintegrating particles in
the cleanser composition (rate of disintegration, C (%)):
[0070] Each cleanser composition sample and tap water were weighed
out by each 3 g on synthetic leather to conduct model cleansing
with one hand for 15 seconds. The cleanser composition was then
rinsed out with tap water (300 g). After the whole rinsings were
collected and left to stand for 30 minutes, the particle diameter
of particles in the rinsings was measured by means of the laser
diffraction/scattering type particle size distribution meter
LA-910. The rate of disintegration was determined in accordance
with the measuring method (2) described above.
[0071] (b) Stability to incorporation:
[0072] The stability of the disintegrating particles, silica powder
or CL-5007 when its corresponding cleanser composition (50 g) was
placed in a 100-ml closed vessel and stored for 1 week in a
thermostatic chamber controlled to 50.degree. C. was expressed in
terms of the rate of disintegration of the particles. The rate of
disintegration was determined in accordance with the measuring
method (2) described above.
[0073] (c) Percent enhancement in cleansing (%):
[0074] A solid fat dyed with
1-[(p-phenylazo)-phenyl]azo[2-naphthol] was coated 15 mm across and
0.1 mm thick on synthesized leather, and the thus-coated leather
was subjected to a cleansing treatment with each of the cleanser
compositions of Examples 1 to 7 and Comparative Examples 1 to 3
containing their corresponding disintegating particles or other
particles, or a cleanser composition in which purified water was
incorporated in place of the disintegrating particles or other
particles. The solid fat remaining on the synthesized leather was
dissolved in an organic solvent, and an absorbance of the resultant
solution was measured. This value was compared with a measured
value of absorbance on a solution with the solid fat remaining on
the synthetic leather not subjected to the cleansing treatment
dissolved in the organic solvent, thereby determining the percent
enhancement in cleansing. Namely, these absorbance values were
substituted into the following equation to determine the percent
enhancement in cleansing. 1 W = W 1 - W 0 100 - W 0 .times. 100 ( %
)
[0075] wherein
[0076] W=percent enhancement in cleansing;
[0077] W.sub.1=absorbance of the cleanser composition containing
the disintegrating particles or other particles; and
[0078] W.sub.0=absorbance of the cleanser composition containing
the purified water.
[0079] (d) Foamability:
[0080] Each (20 g) of the cleanser compositions and tap water (20
g) were placed in a 120-ml glass container (diameter: 40 mm), and
the glass container was shaken 20 times and then left to stand,
thereby judging the foamability from the height (mm) of foam after
30 seconds and 5 minutes.
[0081] (e) Feeling upon use (massaging effect):
[0082] Ten expert women panelists washed their faces with each of
the cleanser compositions, thereby evaluating it as to a feeling
upon massaging in accordance with the following evaluation
standard:
[0083] .circleincircle.: 8 to 10 panelists evaluated it as
good;
[0084] .largecircle.: 6 to 7 panelists evaluated it as good;
[0085] .DELTA.: less than 5 panelists evaluated it as good;
[0086] X: At least one panelists complained a feeling of physical
disorder and irritation.
[0087] (f): Itch on the skin:
[0088] A specified site of the lower arm was subjected to a
cleansing treatment each one time in the morning and evening and 14
times in total with each of the cleanser compositions by means of a
Teflon applicator. Thereafter, the treated site was visually
observed as to desquamation and luster, thereby evaluating the
composition in accordance with the following evaluation standard
(n=10):
[0089] .circleincircle.: No skin lesion observed;
[0090] .largecircle.: Desquamation visibly developed;
[0091] .DELTA.: Desquamation and erythema highly developed;
[0092] X: Eruption or pus visibly developed.
[0093] (g) Rinsability
[0094] Ten expert women panelists were got to wash their faces with
each of the cleanser compositions, thereby evaluating it as to
rinsability from whether a feeling of existence of particles was
given the panelists when washing or rinsing their faces, in
accordance with the following evaluation standard:
[0095] .circleincircle.: 8 to 10 panelists evaluated it as
good;
[0096] .largecircle.: 6 to 7 panelists evaluated it as good;
[0097] .DELTA.: Less than 5 panelists evaluated it as good;
[0098] X: At least one panelists complained a feeling of physical
disorder and irritation.
2TABLE 2 Component Example Comp. Example (wt. %) 1 2 3 4 5 6 7 1 2
3 Disintegrating particles (1) 10.0 -- -- -- -- -- -- -- -- --
Disintegrating particles (2) -- 10.0 -- -- -- -- -- -- -- --
Disintegrating particles (3) -- -- 10.0 -- -- -- -- 10.0 -- --
Disintegrating particles (4) -- -- -- 3.0 -- -- -- -- -- --
Disintegrating particles (5) -- -- -- -- 10.0 -- 5.0 -- -- --
Disintegrating particles (6) -- -- -- -- -- 5.0 -- -- -- -- Silica
powder -- -- -- -- -- -- -- 10.0 -- CL-5007 -- -- -- -- -- -- -- --
-- 10.0 MAP20H 8.6 8.6 8.6 8.6 8.6 15.0 15.0 8.6 8.6 8.6 AMPHITOL
20N -- -- -- -- -- 6.0 6.0 -- -- -- Triethanolamine 10.7 10.7 10.7
10.7 10.7 20.0 20.0 10.7 10.7 10.7 Stearic acid -- -- -- -- -- 3.0
3.0 -- -- -- Glycerol -- -- -- -- -- 3.0 3.0 -- -- -- Methyl
p-hydroxybenzoate -- -- -- -- -- 0.1 0.1 -- -- -- NaCl 9.0 9.0 9.0
11.0 9.0 1.0 1.0 28.0 -- -- KCl -- -- -- -- -- 1.0 -- -- -- --
Purified Water Balance Balance Balance Balance Balance Balance
Balance Balance Balance Balance MAP20H: Lauryl phosphate, Product
of Kao Corporation. AMPHITOL 20N: 35% aqueous solution of
lauryldimethylamine oxide, Product of Kao Corporation. CL-5007:
Polyethylene beads, products of Sumitomo Seika K.K.
[0099]
3 TABLE 3 Percent Stability to Rate of enhancement Formability
Feeling upon incorporation disintegration in cleaning After 30 sec.
After 5 min. use and Itch on the % % % (mm) (mm) massaging skin
Rinsability Ex. 1 15.3 98.5 70 70 65 .circleincircle.
.circleincircle. .circleincircle. Ex. 2 4.1 67.6 68 70 65
.circleincircle. .circleincircle. .circleincircle. Ex. 3 6.9 72.5
67 70 65 .circleincircle. .circleincircle. .circleincircle. Ex. 4
14.1 81.0 53 65 55 .smallcircle. .circleincircle. .circleincircle.
Ex. 5 9.0 78.5 62 70 65 .smallcircle. .circleincircle.
.circleincircle. Ex. 6 8.7 75.6 65 75 72 .circleincircle.
.circleincircle. .circleincircle. Ex. 7 13.2 85.3 65 75 73
.circleincircle. .circleincircle. .circleincircle. Comp. Ex. 1 2.8
64.8 48 8 2 .smallcircle. .DELTA. .circleincircle. Comp. Ex. 2 0 0
61 75 40 .smallcircle. X X Comp. Ex. 3 0 0 68 75 40
.circleincircle. .DELTA. .DELTA.
[0100] As is apparent from Table 3, it is understood that the
disintegrating particles in the cleanser compositions according to
the present invention have high stability to incorporation in the
storage test at 50.degree. C., disintegrate during cleansing and
rinsing and possess excellent rinsability. In addition, the
cleanser compositions have high percent enhancement in cleansing
upon use, give users a pleasant feeling upon use (massaging) and
cause no itch on the skin. Further since the concentration of the
water-soluble salt in the cleanser compositions according to the
present invention is lower than its saturated stability, the
cleanser compositions retain extremely high foamability compared
with the cleanser composition containing the water-soluble salt at
a concentration higher than its saturated solubility in Comparative
Example 1, and so have excellent cleanability and give users a
pleasant feeling upon use.
INDUSTRIAL APPLICABILITY
[0101] The cleanser compositions according to the present invention
have excellent physical (mechanical) cleanability and stability
over time and give users a pleasant feeling upon use. In addition,
the compositions cause little damage to and itchiness of the skin
because the disintegrating particles are disintegrated during
cleansing and rinsing. The particles have excellent rinsability
properties because they are readily disintegrated during
rinsing.
[0102] This application is based on Japanese Patent Application No.
263718/1997 filed on Sep. 29, 1997, the entire contents of which
are hereby incorporated by reference.
[0103] Obviously, numerous modifications and variations of the
present invention are possible in light of the above teachings. It
is therefore to be understood that, within the scope of the
appended claims, the invention may be practiced otherwise than as
specifically described herein.
* * * * *