U.S. patent application number 09/920778 was filed with the patent office on 2002-04-04 for antiperspirant formulations.
This patent application is currently assigned to Unilever Home & Personal Care USA, Division of Conopco, Inc. Invention is credited to Franklin, Kevin Ronald, Turner, Grahm Andrew.
Application Number | 20020039563 09/920778 |
Document ID | / |
Family ID | 9897034 |
Filed Date | 2002-04-04 |
United States Patent
Application |
20020039563 |
Kind Code |
A1 |
Franklin, Kevin Ronald ; et
al. |
April 4, 2002 |
Antiperspirant formulations
Abstract
Anhydrous antiperspirant formulations in which a particulate
antiperspirant active is suspended in a carrier fluid can result in
significant visible deposits when applied to skin or when
transferred onto clothing. Anhydrous antiperspirant suspension
sticks which exhibit very low visible deposits are obtainable by
employing a carrier fluid in which at least 45% and preferably at
least 60% of its weight comprises an oxygen-containing emollient
oil having a refractive index of at least 1.465, in conjunction
with structurant comprises a wax or a non-polymeric fiber-forming
gellant, excluding certain gellants or gellant combinations.
Preferred emollient oils include alkyl benzoates and
alkylphenylsiloxanes. The waxes can even comprise fatty
alcohols.
Inventors: |
Franklin, Kevin Ronald;
(Wirral, GB) ; Turner, Grahm Andrew; (Wirral,
GB) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Assignee: |
Unilever Home & Personal Care
USA, Division of Conopco, Inc
|
Family ID: |
9897034 |
Appl. No.: |
09/920778 |
Filed: |
August 2, 2001 |
Current U.S.
Class: |
424/65 ; 424/400;
424/401; 424/66; 424/67; 424/68 |
Current CPC
Class: |
A61K 8/365 20130101;
A61K 8/37 20130101; A61K 8/0229 20130101; A61K 8/375 20130101; A61K
8/042 20130101; A61K 8/891 20130101; Y10S 424/05 20130101; A61Q
15/00 20130101; A61K 8/44 20130101; A61K 2800/31 20130101; A61K
8/28 20130101; A61K 8/33 20130101 |
Class at
Publication: |
424/65 ; 424/66;
424/67; 424/68; 424/400; 424/401 |
International
Class: |
A61K 007/32; A61K
007/34; A61K 007/36; A61K 007/38; A61K 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 4, 2000 |
GB |
0019232.8 |
Claims
We claim:
1. An anhydrous antiperspirant formulation comprising a particulate
antiperspirant suspended in a water-immiscible carrier fluid which
is structured by an effective amount of a structurant, in which at
least 45% by weight of said carrier fluid comprises an
oxygen-containing emollient oil of higher RI having a refractive
index of at least 1.465, and said structurant comprises a wax or a
non-polymeric fibre-forming gellant other than 12-hydroxystearic
acid alone or in combination with stearic acid or a polymeric
alkylmethylsiloxane obeying formula (I) or (II) or a combination of
.beta.-sitosterol and .gamma.-oryzanol.
2. An antiperspirant stick according to claim 1 in which the
carrier fluid comprises at least 60% by weight of said emollient
oil of higher RI.
3. An antiperspirant stick according to claim 1 in which the
carrier fluid is deficient in or free from an alkoxy cinnamate.
4. An antiperspirant stick according to claim 1 in which the
emollient oil of higher RI comprises an alkyl benzoate, an alkylene
dibenzoate, an alkoxylated alkyl benzoate or a polyalkylene oxide
dibenzoate, or a mixture of two or more thereof.
5. An antiperspirant stick according to claim 4, in which emollient
oil of higher RI comprises an alkyl benzoate in which the alkyl
group contains from 12 to 20 carbon atoms, or mixture of two or
more of said alkyl benzoate compounds.
6. An antiperspirant stick according to claim 5 in which the alkyl
group in the alkyl benzoate is selected from octyldodecyl,
isostearyl, dodecyl to pentadecyl, and mixtures of dodecyl to
pentadecyl.
7. An antiperspirant stick according to claim 4 in which the
alkylene dibenzoate comprises dipropylene glycol dibenzoate.
8. An antiperspirant stick according to claim 4 in which the
alkoxylated alkyl benzoate comprises polypropylene glycol stearyl
ether benzoate, preferably containing from 10 to 20 polypropylene
glycol units.
9. An antiperspirant stick according to claim 4 in which the
polyalkylene oxide dibenzoate comprises a dibenzyl ester of an
ethylene oxide/propylene oxide copolymer.
10. An antiperspirant stick according to claim 1 in which the
emollient oil of high RI comprises a non-volatile silicone oil.
11. An antiperspirant stick according to claim 10 in which the
non-volatile silicone oil comprises a polymethylphenylsiloxane, and
preferably an oil having a methyl:phenyl mole ratio of 1:1.
12. An antiperspirant stick according to claim 11 in which the
non-volatile silicone oil comprises
tetramethyltetraphenyltrisiloxane.
13. An antiperspirant stick according to claim 10 in which the
non-volatile silicone oil has a viscosity of below 300 centistokes
and preferably below 200 centistokes.
14. An antiperspirant stick according to claim 10 in which the
non-volatile silicone oil has a Refractive Index of at least
1.50.
15. An antiperspirant stick according to claim 1 in which the
emollient oil of high RI comprises from 70 to 99% by weight of the
carrier fluid.
16. An antiperspirant stick according to any one of claims 1, 3, 4
or 10 in which the stick contains said wax as structurant in an
amount of from 10 to 25% by weight of the stick.
17. An antiperspirant stick according to claim 1 in which the stick
contains as structurant one or more waxes selected from fatty
alcohols, glyceride waxes, glycol ester waxes, and alkylalkanoate
waxes.
18. An antiperspirant stick according to claim 17 in which the
structurant comprises a combination of a glyceride wax with at
least one second wax selected from glycol ester waxes,
alkylalcanoate waxes and fatty alcohols.
19. An antiperspirant stick according to claim 18 in which the
glyceride wax is present in a weight ratio to the second wax or
waxes of 1:2 to 1:6 and preferably from 2:5 to 1:4.
20. An antiperspirant stick according to claim 1 in which it
contains said non-polymeric fibre-forming gellant as structurant in
an amount of from 4 to 12% by weight of the stick.
21. An antiperspirant stick according to claim 20 in which the
non-polymeric fibre-forming gellant comprises a mixture of
non-polymeric fibre-forming gellants.
22. An antiperspirant stick according to claim 21 in which the
mixture of said gellants comprises 12-hydroxystearic acid and an
N-alkyl-L glutamic acid di-alkylamide, preferably in a weight ratio
of the former to the latter of from 1:1 to 5:1.
23. An antiperspirant stick according to claim 1 in which the
structurant comprises a mixture of wax and non-polymeric
fibre-forming gellant.
24. An antiperspirant stick according to claim 23 in which the
weight of wax in the stick is selected in the range of from 5 to
12%.
25. An antiperspirant stick according to claim 24 in which the wax
is present in a weight ratio to the non-polymeric fibre-forming
gellant of from 1:1 to 3:1.
26. An antiperspirant stick according to claim 24 or 25 in which
the wax is an alkyl alkanoate wax and the non-polymeric
fibre-forming gellant is 12-hydroxystearic acid.
27. An antiperspirant stick according to any one of claims 1, 3, 4,
16, 20 or 21 which contains up to 5% by weight glycerol.
28. A process for making an antiperspirant stick comprising the
steps of: i. incorporating into a liquid carrier a structurant at
an effective concentration and in an amount sufficient to structure
the carrier to render it solid at 20.degree. C. ii. rendering the
structurant-containing mixture or one or more of its constituents
mobile at an elevated temperature iii. mixing the liquid carrier
with an antiperspirant active to form an antiperspirant-containing
mixture, steps 2 and 3 being conducted either before, after or
simultaneously with step 1 iv. introducing the mobile mixture into
moulding means and v. cooling or permitting the mobile mixture to
cool to a temperature at which it is structured, in which at least
45% by weight of said carrier fluid comprises an oxygen-containing
emollient oil having a refractive index of at least 1.465, and said
structurant is a wax or a fibre-forming gellant other than
12-hydroxystearic acid alone or in combination with stearic acid or
a polymeric alkylmethylsiloxane obeying formula (I) or (II) or a
combination of .beta.-sitosterol and .gamma.-oryzanol.
29. A method of reducing or controlling axillary sweating
comprising applying topically to skin an anhydrous antiperspirant
formulation comprising a particulate antiperspirant suspended in a
water-immiscible carrier fluid which is structured by an effective
amount of a structurant, in which at least 45% by weight of said
carrier fluid comprises of an oxygen-containing emollient oil of
higher RI having a refractive index of at least 1.465, and said
structurant is a wax or a non-polymeric fibre-forming gellant other
than 12-hydroxystearic acid alone or in combination with stearic
acid or a polymeric alkylmethylsiloxane obeying formula (I) or (II)
or a combination of .beta.-sitosterol and .gamma.-oryzanol.
30. An antiperspirant product comprising an antiperspirant
formulation in the form of a stick disposed within a packaging
which enables a portion of the stick to be exposed for topical
application to skin in which the formulation comprises a
particulate antiperspirant suspended in a water-immiscible carrier
fluid which is structured by an effective amount of a structurant,
in which at least 45% by weight of said carrier fluid comprises of
an oxygen-containing emollient oil of higher RI having a refractive
index of at least 1.465, and said structurant is a wax or a
non-polymeric fibre-forming gellant other than 12-hydroxystearic
acid alone or in combination with stearic acid or a polymeric
alkylmethylsiloxane obeying formula (I) or (II) or a combination of
.beta.-sitosterol and .gamma.-oryzanol.
Description
[0001] The present application relates to antiperspirant
formulations, and in particular to antiperspirant stick
formulations.
BACKGROUND AND PRIOR ART
[0002] Topically applied antiperspirant compositions are in
widespread use throughout much of the world, in order to enable
their users to avoid or minimise visible wet patches on their skin,
especially in axillary regions. Antiperspirant formulations
containing astringent metal salts such as aluminium or zirconium
salts commonly act also as deodorants. Antiperspirant formulations
have been produced or proposed for use in several physical forms,
such as solids, gels, soft solids, creams, lotions and particulate
mixtures and these forms can be applied using a range of different
dispensers, including aerosol, roll-on, pump spray, sticks, and
barrel dispensers, in accordance with the individual preferences of
consumers. In some parts of the world, solid formulations in stick
form are especially popular, the stick usually being dispensed from
a barrel provided with means to expose the stick above the
barrel.
[0003] Herein, the term stick indicates a bar of solid material
which retains its integrity whilst being applied, i.e. a firm stick
and which is commonly, though not exclusively, housed within a
dispensing container which hitherto is conveniently in the shape of
a barrel. When a portion of a firm stick is drawn across the skin
surface, a film of the stick composition is transferred onto the
skin surface. Although the stick has the appearance of a solid
article, the material forming the stick usually comprises a
structured liquid phase such that a film of the material is readily
transferred onto another surface such as axillary skin upon contact
under pressure.
[0004] There are typically three classes of firm antiperspirant
sticks, namely suspension sticks, emulsion sticks and solution
sticks. Suspension sticks contain a particulate antiperspirant
active material suspended in a structured carrier. Emulsion sticks
normally comprise an emulsion of an oil phase and a hydrophilic
phase containing the antiperspirant active in solution, the
continuous phase being structured. In some emulsion sticks, the
continuous phase is an oil phase. In solution sticks, the
antiperspirant is typically dissolved in the liquid carrier phase
which is structured. The liquid phase can comprise water and/or a
water-miscible organic solvent. The three categories can be applied
to sticks of both firm and soft solids compositions.
[0005] Conventionally, many suspension sticks have been structured
using naturally-occurring or synthetic waxes, of which typical
examples include stearyl alcohol, hydrocarbon waxes, waxes of plant
or animal origin or their synthetic analogues or derivatives or
silicone waxes. Waxes are widely available, and by suitable
selection of the waxes themselves and their concentrations in the
formulation can effectively obtain either a soft solid or a firm
solid. Thus for example, wax-structured sticks are described in an
article in Cosmetics and Toiletries, 1990, vol. 105, p75-78.
However, many conventional fatty alcohol or other wax structured
sticks tend to leave visible white deposits on application to human
skin, and likewise, visible deposits can also be transferred onto
clothing by physical contact with the skin. Such visible deposits
are disliked by a significant, and in some countries growing,
proportion of consumers of antiperspirants, be they on the skin or
on clothing. Accordingly, the antiperspirant industry, including
the instant inventors, is continuing devoting considerable time and
resources to finding means to ameliorate or overcome customer
perceived whiteness deposits. In countries where both traditional
and low whitening antiperspirant stick products are available,
sales of the low whitening formulations have grown relative to
traditional formulations.
[0006] Patents and patent documents relevant to this field of
invention include:
1 USP 3,255,082; Barton et al; USP 3,986,203; Spitzer et al; USP
4,083,956, Shelton; EP-A-0,028,853, Beckmeyer et al; USP 4,425,328,
Nabial et al; USP 4,265,878, Keil; USP 4,229,432, Geria; USP
4,724,139, Palinczar USP 4,985,238, Tanner et; USP 5,486,347,
Callaghan et al and USP 6,068,518, Bianchi et al.
[0007] Antiperspirant formulations remain on the skin for
considerable periods of time after application, for example many
hours before the axilla or other part of the body to which the
antiperspirant has been applied is washed. In that respect they
differ significantly from many other personal care formulations
such as washing or cleansing formulations which are applied and
almost immediately removed. Accordingly, all non-volatile
components present in the antiperspirant formulations remain on the
skin, including not only non-volatile anti-perspirant actives, but
also non-volatile components of any carrier fluid which is
employed. Such non-volatile components not only remain on the skin,
but likewise remain available for transfer onto clothing which
comes into contact with the skin. Carrier liquid components can
assist in the transfer of solids suspended therein.
[0008] Since their introduction, volatile silicone fluids have been
widely accepted within the antiperspirants industry as carrier
fluids for antiperspirant solids, and commonly are either thickened
to form a cream or structured to form a solid in order to suspend
particulate antiperspirant materials. Volatile silicone oils have
proven to be very popular, on account of their combination of
beneficial properties, so that in many or most of the common
commercial anhydrous suspension stick formulations, such oils
constitute the principal proportion of the carrier fluid. One or
more other oils, such as non-volatile silicone oils or non-volatile
non-silicone emollient oils are often included or proposed for
inclusion in patent specifications in minor amounts in firm stick
suspended antiperspirant formulations, and indeed together commonly
constitute no more than a minor fraction of the carrier fluid.
[0009] Although volatile silicone oils enable the antiperspirant
formulations to exhibit many desirable properties, there are two
consequences of employing them as the principal component of the
carrier fluid, namely that such antiperspirant formulations tend to
exhibit comparatively high visible whiteness when they are
topically applied and also the visible whiteness of such
formulations tends to increase further with the passage of time.
Without being bound to any theory, it is believed that increased
visible whiteness arises from evaporation of the volatile
silicones, thereby exposing those formulation components such as
particulate antiperspirant actives and/or structurant which
contribute to visible whiteness. These observations are of
relevance, because users look carefully at where they are applying
antiperspirant formulations, and they often remain on the skin for
extended periods of time.
[0010] However, it is no simple matter to reformulate
antiperspirant formulations with alternative oils. Whilst many oils
have been accepted within the industry as minor components of a
volatile-silicone-based carrier fluid, the very properties which
have rendered them suitable to be considered suitable as emollients
have been thought to render them unsuitable as the principal
carrier oil. These properties include a propensity to oiliness or
greasiness in the resultant product, when present in a large
proportion.
[0011] A number of attempts have been made already to address the
problems of selecting carrier fluids for
antiperspirant-formulations. Several patent specifications offer
lists of emollient oils for incorporation in carrier fluids, in
some instances for creams, such as in EP-A-388110 and WO-A-98/51272
and in other instances for sticks, such as U.S. Pat. No. 5,833,964.
These specifications classify as similar, materials which the
investigation resulting in the present invention show to be
significantly different. Accordingly, although such specifications
assert that they provide formulation exhibiting low visible
deposits, this assertion is often judged against those sticks which
were commercially available when the applications were sought and
in practice, there often remains considerable room for improvement
and do not provide adequate teaching to the skilled formulator to
enable that person to choose effectively. Other patent
specifications have disclosed the use of certain specified types of
hydrocarbons, such as poly alpha olefins in U.S. Pat. No. 4,919,934
and EP-A-804921, in respectively sticks or creams. In view of the
feel associated with hydrocarbons, it remains a desideratum to
provide formulations which have a lower non-volatile hydrocarbon
content.
[0012] The visibility of a surface deposit depends on the
constituents of the applied formulation, including not only the
active constituent and any carrier fluid, but also the structurant
that is employed when forming the formulation into a stick.
EP-A-396137 (Gillette) discloses compositions which are structured
using polyethylene-vinyl acetate copolymers or polyethylene
homopolymers or blends, and accordingly provides no teaching for
formulations employing waxes and/or non-polymeric fibre-forming
structurants as the main or entire structurant. Its examples employ
alkylmethyoxy cinnamates as the principle solvent. For the reasons
of colour, odour and irritancy identified hereinbelow, it is
undesirable to employ methoxy cinnamates in compositions intended
for use by the general public, so the skilled man would be
prejudiced against this text.
OBJECT OF THE INVENTION
[0013] It is an object of the present invention to ameliorate or
overcome one or more of the disadvantages of suspension
antiperspirant formulations disclosed hereinabove.
[0014] It is a further object of at least some embodiments of the
present invention to provide a suspension formulation employing a
carrier having a non-volatile oil as principal carrier.
BRIEF DESCRIPTION OF THE INVENTION
[0015] According to the present invention there is provided an
anhydrous antiperspirant formulation comprising a particulate
antiperspirant suspended in a water-immiscible carrier fluid which
is structured by an effective amount of a structurant,
characterised in that at least 45% by weight of said carrier fluid
comprises an oxygen-containing emollient oil having a refractive
index of at least 1.465, and said structurant is a wax or a
fibre-forming gellant other than 12-hydroxystearic acid alone or in
combination with stearic acid or a polymeric alkylmethylsiloxane
obeying formula (I) or (II) or a combination of .beta.-sitosterol
and .gamma.-oryzanol.
[0016] Herein, Formula (I) represents
Me.sub.3SiO--[Si(Me)((CH.sub.2).sub.zMe)O--].sub.x-SiMe.sub.3
and
[0017] Formula (II) represents
Me.sub.3SiO--[Si(Me)((CH.sub.2).sub.zMe)O--].sub.x[--SiMe.sub.2O--]--SiMe.-
sub.3
[0018] in which x has a value of 1-50, y has a value of 1-100 and z
has a value of 10-40.
[0019] Herein, the term oxygen-containing emollient oil having a
refractive index of at least 1.465 is often abbreviated to HR
emollient.
[0020] Herein, the refractive index is measured at 22.degree. C.,
using a refractometer for liquids and a comparative method for
solids, unless otherwise specified.
[0021] By the choice of such a combination of carrier fluid
components and structurant, it has been possible to obtain
antiperspirant sticks showing excellently low visible deposits.
[0022] In a second aspect of the present invention there is
provided a process for the production of an antiperspirant stick
comprising the steps of
[0023] i. incorporating into a liquid carrier a structurant at an
effective concentration and in an amount sufficient to structure
the carrier to render it solid at 20.degree. C.
[0024] ii. rendering the structurant-containing mixture or one or
more of its constituents mobile at an elevated temperature
[0025] iii. mixing the liquid carrier with an antiperspirant active
to form an antiperspirant-containing mixture, steps 2 and 3 being
conducted either before, after or simultaneously with step 1
[0026] iv. introducing the mobile mixture into moulding means
and
[0027] v. cooling or permitting the mobile mixture to cool to a
temperature at which it is structured, characterised in that at
least 45% by weight of said carrier fluid comprises an
oxygen-containing emollient oil having a refractive index of at
least 1.465, and said structurant is a wax or a fibre-forming
gellant other than 12-hydroxystearic acid alone or in combination
with stearic acid or a polymeric alkylmethylsiloxane obeying
formula (I) or (II) or a combination of .beta.-sitosterol and
.gamma.-oryzanol.
[0028] In a third aspect, there is provided a method of reducing or
controlling axillary sweating comprising applying topically to skin
an anhydrous antiperspirant formulation comprising a particulate
antiperspirant suspended in a water-immiscible carrier fluid which
is structured by an effective amount of a structurant,
characterised in that at least 45% by weight of said carrier fluid
comprises of an oxygen-containing emollient oil of higher RI having
a refractive index of at least 1.465, and said structurant is a wax
or a non-polymeric fibre-forming gellant other than
12-hydroxystearic acid alone or in combination with stearic acid or
a polymeric alkylmethylsiloxane obeying formula (I) or (II) or a
combination of .beta.-sitosterol and .gamma.-oryzanol.
[0029] In a fourth aspect of the present invention there is
provided an antiperspirant product comprising an antiperspirant
formulation in the form of a stick disposed within a packaging
which enables a portion of the stick to be exposed for topical
application to skin characterised in that the formulation comprises
a particulate antiperspirant suspended in a water-immiscible
carrier fluid which is structured by an effective amount of a
structurant, characterised in that at least 45% by weight of said
carrier fluid comprises of an oxygen-containing emollient oil of
higher RI having a refractive index of at least 1.465, and said
structurant is a wax or a non-polymeric fibre-forming gellant other
than 12-hydroxystearic acid alone or in combination with stearic
acid or a polymeric alkylmethylsiloxane obeying formula (I) or (II)
or a combination of .beta.-sitosterol and .gamma.-oryzanol.
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
[0030] The present invention provides antiperspirant sticks
structured with wax and/or non-polymeric fibre-forming gellant in
which a particulate antiperspirant active is suspended in a carrier
fluid comprising a substantial fraction of HR emollient oil or
oils.
[0031] The choice of the HR emollient oil in a high proportion of
the carrier fluid is of importance in the present invention. In
essence, the HR emollient oil, or each of the oils if more than one
oil is employed, satisfies three criteria. First, it is an
anhydrous water-immiscible oil which is fluid at ambient
temperature, such as 20.degree. C. Secondly, the oil has a
relatively high refractive index, and specifically a refractive
index of above 1.465 and thirdly it is oxygen-containing.
[0032] By the choice of an HR emollient oil, and by employing it in
a high proportion of the carrier fluid, it is possible to obtain
sticks with a wide choice of structurant, but which leave no higher
than very low visible white deposits on skin or clothing. The
ability to have a wide choice of structurant is of considerable
benefit to antiperspirant manufacturers in that it means that they
are not restricted to a narrow range of materials. The resultant
very low visible white deposits, even when employing waxes which
have acquired a reputation for leaving high or comparatively high
visible white deposits, is manifestly of benefit in view of the
prevailing desire expressed by consumers for antiperspirants which
do not leave unsightly marks on clothing or on the skin
surface.
[0033] Many HR emollients have a refractive index of at least 1.47
and most of up to 1.56. A number of especially desirable HR
emollient have a refractive index in the region of 1.47 to 1.49.
They can be employed individually or mixed together. Yet other
desirable HR emollients have a refractive index in the region of
1.50 to 1.56, which can also be used individually or mixed
together. If desired, it is possible to employ a mixture of an HR
emollient having a refractive index of up to 1.49 with that having
a refractive index of at least 1.50. Mixtures of HR emollients can
be selected at weight ratios of the individual emollients at the
discretion of the formulation maker.
[0034] It is highly desirable to employ HR emollients which impart
little or no colour to formulations containing them. Accordingly,
it is preferred to avoid or minimise the incorporation of alkoxy
cinnamates, even if such compounds demonstrate a refractive index
of above 1.5, such as by restricting the content of such cinnamates
to be alkoxy-cinnamate deficient by which we mean below 5% of the
weight of the carrier fluid, or preferably free from alkoxy
cinnamates, by which herein we mean below 1% and especially down to
0%. Such cinnamates tend to be highly coloured, especially in the
yellow region of the spectrum, and would render antiperspirant
stick less acceptable or even unacceptable to potential consumers.
Likewise, there are two further reasons for avoiding or minimising
the incorporation of such alkoxy cinnamates. It is desirable to
avoid employing or at least minimise the presence of any emollient
which has an intrinsically high and unpleasant odour or one which
would cause unacceptable irritation.
[0035] The proportion of HR emollient in the carrier fluid is at
least 45% by weight, and in many desirable formulations is at least
50% or from 55% by weight. If desired, it can comprise as much as
100% of the carrier fluid. However, in practice, the formulation
also includes a number of other liquid constituents such as
fragrance or other liquid emollients, so that it commonly provides
no more than 99% and in a considerable fraction of suitable
formulations, up to 95% by weight of the carrier fluid. In a number
of formulations, the proportion of HR emollient is at least 60% by
weight and more desirably at least 70% by weight and especially at
least 80% by weight of the carrier fluid. In a preferred range, the
HR emollient comprises from 70 to 99% by weight of the carrier
fluid.
[0036] The HR emollients of the present invention are oxygen
containing, that is to say within the oil there is at least one
oxygen atom, which may be embedded within the backbone of the
emollient or in a side chain or comprise a substituent. There are
two particularly desirable classes of HR emollients, namely a)
alkylated or alkoxylated benzoates and b) non-volatile silicone
oils. In class a) the oxygen is embedded within a carbon backbone
i.e. a C--O--C sub-structure and within class b) within a silicon
backbone, i.e. an Si--O--Si sub-structure.
[0037] Within class a) HR emollients, sub groups include alkyl
benzoate, alkylene dibenzoate, alkoxylated alkyl benzoate or a
polyalkylene oxide dibenzoate, or a mixture of two or more
sub-classes thereof. The alkyl group often contains at least 10
carbons, in many instances up to 25 carbons. It is often linear,
but can alternatively be branched.
[0038] Especially desirable alkyl groups are found in the range of
from 12 to 20 carbons and include dodecyl (lauryl) terdecyl,
tetradecyl (myristyl), pentadecy, hexadecyl (palmityl), octdecyl
(stearyl) 2-methyl-heptadecyl (iso-stearyl) and octyldodecyl
groups. A mixture of two or more of the alkyl groups can be
employed, such as a mixture of C12-C15 alkyl groups. The term
alkylated herein includes alkylene groups and the latter are
terminated at each end with a benzoate group. The alkylene group
often contains from 2 to 6 carbons and can be linear or branched, a
suitable example of linear being propylene.
[0039] In the alkoxylated alkyl benzoates contemplated herein, the
alkyl group is terminated by an alkoxy group, which can be
monomeric containing for example up to 6 carbons or polymeric such
as polyethylene oxide or preferably polypropylene oxide, which
conveniently comprises up to 30 units and often from 5 to 20 units.
In such compounds, the alkyl group can be selected from the
previously identified alkyl groups. Alternatively, the benzoate
compound can comprise a polyethylene oxide or polypropylene oxide
moiety, or preferably a block copolymer of ethylene oxide and
propylene oxide, terminated at each end by a benzoate group.
Mixtures of two or more of the benzoate sub-classes of compounds
can be employed. This first class of HR emollients tends to have a
refractive index in the region of 1.465 to 1.49.
[0040] Several preferred benzoate compounds which are HR emollients
are available from Finetex under their trade name Finsolv. Although
Finsolv P is a yellow liquid, its use appears not to result in
formulations having a significant hue.
[0041] The second class (b) of HR emollients comprises non-volatile
silicone oils. Such compounds commonly comprise alkylphenyl
substituted polysiloxanes, and especially methylphenyl
polysiloxanes. Desirably, the polysiloxane is short chain and
linear, such as a disiloxane, trisiloxane or tetrasiloxane.
Particularly desirably, the mole ratio of alkyl (especially methyl)
to phenyl substitution is 1:1. It is especially desirable to select
within the class of non-volatile polysiloxane materials those which
have a viscosity of below 300 centistokes (300.times.10.sup.-6
M.sup.2s.sup.-1) and advantageously those of below 200 centistokes
(200.times.10.sup.-6 M.sup.2s.sup.-1). In practice, the viscosity
of preferred siloxane materials is often in the region of 50
centistokes or higher. The refractive index of preferred
non-volatile silicone oils, such as those comprising
alkylphenylsiloxanes normally fall within the range of 1.50 to
1.56. Examples of highly preferred non-volatile siloxanes include
PDM-7040 and PDM-7050 (trade names) obtainable from Gelest and DC
704 (trade name) obtainable from Dow Corning Inc.
[0042] The remaining constituents of the carrier fluid normally
comprise other fluids which are miscible with the HR emollient or
soluble in the final mixture, thereby forming an anhydrous fluid
carrier. Anhydrous herein indicates that the formulation is free
from a distinct aqueous phase, which means in practice that it does
not comprise an aqueous emulsion or micro-emulsion. The choice of
other carrier fluids is at the discretion of the formulator, within
the bounds indicated herein. In practice, they tend to be
hydrophobic, although a limited proportion of hydrophilic
constituents can be employed, such as those materials which, in the
chosen proportions, are still miscible with the remainder of the
carrier fluid.
[0043] Hydrophobic oils which can be employed herein as non-HR
components of the carrier fluid have a refractive index of below
1.465, and for ease of reference are sometimes referred to herein
as LR oils. In view of the relative proportions of the HR
emollients and LR oils in the carrier fluid, the average RI of the
carrier is often in the range of from about 1.43 to 1.46. This
means that it is not matched to the refractive index of the
suspended particulate antiperspirant, so that the observed low
scores for visible deposits is normally not achieved by RI
matching. It is of considerable value to be able to achieve such
good results without RI matching, because it is a particularly
difficult problem to match constituents sufficiently closely and
consistently in commercial scale production and under commercial
operating conditions.
[0044] The maximum proportion of LR oils in the carrier fluid is
the balance above the proportion provided by the HR emollients. The
full breadth of the ranges of proportions for LR oils indicated
hereinbelow are attainable only to the extent that the balance
above the HR emollient proportion permits this.
[0045] One suitable class of LR oil comprises volatile liquid
silicones, i.e. liquid polyorganosiloxanes. To class as "volatile"
such material should have a measurable vapour pressure at 20 or
25.degree. C. Typically the vapour pressure of a volatile silicone
lies in a range from 1 or 10 Pa to 2 kPa at 25.degree. C.
[0046] It can be desirable for the carrier fluid to include a
volatile silicone because it gives a "drier" feel to the applied
film after the composition is applied to skin. The carrier fluid
often contains from 0 to 50% and particularly from 10 to 40% by
weight volatile silicone
[0047] Volatile polyorganosiloxanes can be linear or cyclic or
mixtures thereof. Preferred cyclic siloxanes include
polydimethylsiloxanes and particularly those containing from 3 to 9
silicon atoms and preferably not more than 7 silicon atoms and most
preferably from 4 to 6 silicon atoms, otherwise often referred to
as cyclomethicones. Preferred linear siloxanes include
polydimethylsiloxanes containing from 3 to 9 silicon atoms. The
volatile siloxanes normally by themselves exhibit viscosities of
below 10.sup.-5 M.sup.2/sec (10 centistokes), and particularly
above 10.sup.-7 M.sup.2/sec (0.1 centistokes), the linear siloxanes
normally exhibiting a viscosity of below 5.times.10.sup.-6
m.sup.2/sec (5 centistokes). The volatile silicones can also
comprise branched linear or cyclic siloxanes such as the
aforementioned linear or cyclic siloxanes substituted by one or
more pendant --O--Si(CH.sub.3).sub.3 groups. Examples of
commercially available silicone oils include oils having grade
designations 344, 345, 244, 245 and 246 from Dow Corning
Corporation; Silicone 7207 and Silicone 7158 from Union Carbide
Corporation; and SF1202 from General Electric.
[0048] Other hydrophobic oils, which can be contemplated to provide
at least a part of the non-HR oxygen-containing fraction of the
fluid carrier, comprise liquid aliphatic hydrocarbons such as
mineral oils or hydrogenated polyisobutene, often selected to
exhibit a low viscosity. Further examples of liquid hydrocarbons
are polydecene and paraffins and isoparaffins of at least 10 carbon
atoms. Although polyisobutene and polydecene are polymeric in
nature, they are mobile liquids at room temperature of 20.degree.
C. and do not cause thickening of other hydrophobic oils. Some
mineral oils may have an RI which approaches 1.465. Such oils may
be used.
[0049] Other LR oils can comprise liquid aliphatic esters. Suitable
aliphatic esters usually contain at least one long chain alkyl
group, such as esters derived from C.sub.1 to C.sub.20 alkanols
esterified with a C.sub.8 to C.sub.22 alkanoic acid or C.sub.6 to
C.sub.10 alkanedioic acid. The alkanol and acid moieties or
mixtures thereof are preferably selected such that they each have a
melting point of below 20.degree. C. These esters include isopropyl
myristate, lauryl myristate, isopropyl palmitate, diisopropyl
sebacate and diisopropyl adipate. The proportion of aliphatic
esters in the carrier fluid is often chosen within the range of 0
to 50% and particularly 0 to 25% of the carrier.
[0050] Aliphatic alcohols which are liquid at 20.degree. C. may be
employed as an LR oil. These include branched chain alcohols of at
least 10 carbon atoms e.g. 10 to 25 carbons, such as isostearyl
alcohol and octyl dodecanol. The proportion of liquid aliphatic
alcohol in the carrier fluid is often chosen within the range of 0
to 50% and particularly 0 to 25% of the carrier.
[0051] Other suitable LR oils include aliphatic ethers that are
liquid at 20.degree. C., which are derivable from at least one
alkanol containing at least 4 carbons and often up to 18 carbons,
and which often contain a polyalkylene glycol moiety. Examples of
such ethers include myristyl ether derivatives e.g. PPG-3 myristyl
ether or lower alkyl ethers of polypropylene glycols such as PPG-14
butyl ether which is commercially available from Amercol under the
trade name Fluid AP. The proportion of liquid aliphatic ethers in
the carrier fluid is often chosen within the range of 0 to 50% and
particularly 0 to 25% of the carrier.
[0052] Each of the above-identified classes of LR oils can provide
the balance of the carrier fluid. However, it is preferred that at
least a fraction of said balance comprises the volatile silicone
oil so that the balance generally comprises a mixture of a volatile
silicone oil and one of the other LR oils. The weight ratio of
volatile silicone oil to other LR oils is often chosen in the range
of from 1:4 to 3:1.
[0053] Structurants
[0054] Waxes
[0055] The term "wax" is conventionally applied to a variety of
materials and mixtures which have similar physical properties,
namely that:
[0056] they are solid at 30.degree. C. and preferably also at
40.degree. C.;
[0057] they melt to a mobile liquid at a temperature above
30.degree. C. but generally below 95.degree. C. and preferably in a
temperature range of 40.degree. C. to 90.degree. C.;
[0058] they are water-insoluble and remain water-immiscible when
heated above their melting point.
[0059] Waxes are usually hydrocarbons, or silicone polymers, or
linear fatty alcohols, esters of fatty acids or glyceride
derivatives or mixtures containing such compounds, possibly also
containing a minority (less than 50%) of other compounds. Naturally
occurring waxes are often mixtures of compounds which include a
substantial proportion, likely to be a majority, of fatty
esters.
[0060] A wax forms crystals in the carrier fluid when it cools from
the heated state during processing.
[0061] These crystals take various forms including needles and
platelets depending on the individual waxes. Some waxes form a
network of fibrous crystals and can therefore also be identified as
fibre-forming structurants.
[0062] Examples of hydrocarbon waxes include paraffin wax,
microcrystalline wax and polyethylenes with molecular weight of
2,000 to 25,000.
[0063] Waxy linear fatty (aliphatic) alcohols normally contain at
least 10 and preferably at least 12 carbon atoms, in practice often
not more than 40 carbon atoms and many preferred alcohols contain
from 14 to 25 carbon atoms. Many formulations which have previously
been targeted at low visible white deposits have sought to
eliminate altogether or at least severely restrict the proportion
of fatty alcohol as wax structurant therein, indicating a
preference for below 1% and more preferably zero percent. It is to
the great advantage of the instant invention, that the benefit of
very low visible deposits can be achieved whilst still permitting
the fatty alcohols to be used as a significant contributor to the
structuring (solidification) of the carrier fluid.
[0064] Two suitable classes of ester waxes include a) glycerol or
glycol esters and b) alkyl alkanoate esters. Within class a) the
waxes are selected from fatty acid derivatives of glycerol or
glycol, such as ethylene glycol. Preferably at least two ester
groups are present in the ester waxes. The fatty acid moiety
therein normally contains at least 10 carbons and especially from
12 to 24 carbons. Commonly the esters are derived from stearic acid
or benhenic acid or a mixture of fatty acids, such as those
containing either or both of said acids e.g. C.sub.16-C.sub.22
fatty acids. It is especially desired to employ glycerol esters.
Some esters may be present as components in certain naturally
occurring waxes and they these may also be made synthetically. A
number of suitable waxes are available from Croda Chemicals under
their trade name "Synchrowax", e.g. Synchrowax ERLC.
[0065] A second class of ester wax comprises esters which have a
melting point of at least 30.degree. C. and which satisfy the
general formula W1 below:
CH.sub.3--(CH.sub.2).sub.n--O--CO--(CH.sub.2).sub.m--CH.sub.3
[0066] in which n is from 9 to 39 and m is from 0 to 35.
[0067] Within general formula W1, a range of preferred esters
comprises those in which n is selected within the range of 14 to 24
and especially 16-22 together with m being selected in the range of
14 to 24 and especially 16 to 22. In second range of preferred
esters within the general formula, n is selected in the range of 18
to 38 and m is either 0 or 1. It will be understood that mixtures
of esters within each preferred range or mixtures of one preferred
range of esters with the other can be employed. Some convenient
mixtures include a mixture of a wax comprising esters of n=14 to 20
and m=14 to 20 with a wax comprising esters of n=16 to 20 and m=14
to 20 or preferably 16 to 20. A number of alkyl alkanoate ester
waxes are available from Koster Keunen under their trade name
"Kesterwax", e.g. those having designations K62, K69, K80H, K80P,
K82H and K82N. Other suitable waxes within this sub-class are
available from Strahl and Pitsch under their trade names SP-C36 and
SP-C44 (stearyl stearate and behenyl behenate respectively).
[0068] Mixtures of the ester waxes can be employed, either within
either class of ester or a mixture of both classes.
[0069] A useful class of waxes comprises those which comprise or
consist of glyceride waxes and in particular triglyceride waxes.
Many suitable glyceride waxes comprise esters of fatty acids, often
containing at least 16 carbon atoms, and especially from 18 to 36
carbon atoms. Examples of suitable ester moieties include stearate,
eicosinate and behenate. Certain of them can be derived from
naturally occurring oils such as castor oil by hydrogenation. Yet
others include tristearin, or are obtainable by hydrogenating
vegetable oils such as rape seed oil. A number of triglyceride
waxes are obtainable from Croda Chemicals under their trade name
Syncrowax, e.g. grades HRC and HGL-C.
[0070] Examples of natural waxes or simple derivatives of natural
products include castor wax, beeswax, carnauba and candelilla
waxes, which are of vegetable origin and mineral waxes from fossil
remains other than petroleum. Montan wax, which is an example of
mineral wax, includes non-glyceride esters of carboxylic acids,
hydrocarbons and other constituents. Other naturally available
waxes include spermeceti wax, ozokerite, ceresin, baysberry, and
synthetic waxes such as Fisher-Tropsch waxes and microcrystalline
waxes.
[0071] Waxes useful in the present invention will generally be
those found to thicken water-immiscible oxygen-containing HR
emollient oils such as C.sub.12-15 alkyl benzoates and/or
non-volatile methylphenylpolysiloxanes when dissolved therein (by
heating and cooling) at a concentration of 5 to 25% by weight.
[0072] The wax is normally employed in such an amount that the
carrier fluid is structured in combination with any other
structurant that is present and the presence of any particulate
antiperspirant and other solids. This amount is usually not greater
than the weight of the carrier fluid, and in most instances not
greater than 30% of the weight of the composition.
[0073] If a wax is used which forms a network of fibres, the amount
of it may commonly be from 4 to 12% by weight of the composition.
If a wax is used which does not form such a network, for instance a
wax which crystallises as spheralitic needles or as small
platelets, the amount is often selected in the range of from 4 to
25% and in many preferred embodiments from 5 to 12% or 10 to 25% of
the composition, depending at least in part upon whether the wax is
being employed in conjunction with or without a further
structurant. Silicone waxes are an example of waxes which
crystallise as small platelets.
[0074] It is often desirable to employ a combination of waxes.
Preferred combinations include a combination of a glyceride wax
with at least one second wax selected from glycerol ester waxes,
alkylalkanoate waxes and fatty alcohols, including specifically
those waxes mentioned by name hereinbefore. Preferably, the
glyceride wax is present in a weight ratio to the second wax or
waxes of 1:2 to 1:6 and more preferably from 2:5 to 1:4.
[0075] Fibre-forming Gellants
[0076] A number of organic compounds are known to possess the
ability to gel water-immiscible organic liquids such as
water-immiscible hydrocarbon and/or silicone oils. Such materials
are generally non-polymeric, i.e. monomers or dimers with molecular
weight below 10,000 often below 5,000 or even 1,000 rather than
polymers with more than four repeat units or with molecular weight
above 10,000.
[0077] Gel formation takes place as an exothermic event within a
temperature range referred to as the gel point; upon re-heating,
melting of the gel takes place as an endothermic event within a
temperature range. Such gels can be disrupted by shearing. Although
a small partial recovery may then be observed, such gels do not
recover their structure for a long time, if at all, unless
re-melted.
[0078] Materials with this ability to gel water-immiscible organic
liquids have been reviewed by Terech and Weiss in "Low Molecular
Mass Gelators of Organic Liquids and the Properties of their Gels"
Chem. Rev 97, 3133-3159 [1997] and by Terech in Chapter 8,
"Low-molecular weight Organogelators" of the book "Specialist
surfactants" edited by I D Robb, Blackie Academic Professional,
1997.
[0079] It is characteristic of such non-polymeric gellants
(structurants), useful in this invention, that:
[0080] they are able to gel the organic liquid in the absence of
any disperse phase, when used in sufficient quantity not exceeding
15% by weight;
[0081] the structured liquids are obtainable by cooling from an
elevated temperature at which the structurant is in solution in the
liquid--this hot solution being mobile and pourable;
[0082] the (thus obtained) structured liquid becomes more mobile if
subjected to shear or stress;
[0083] the structure does not spontaneously recover within 24 hours
if the sheared liquid is left to stand at ambient laboratory
temperature, even though a small partial recovery may be
observed;
[0084] the structure can be recovered by re-heating to a
temperature at which the structurant is in solution in the liquid
and allowing it to cool back to ambient laboratory temperature.
[0085] It appears that such non-polymeric structurants operate by
interactions which are permanent unless disrupted by shear or
heating. Such structurants form a network of strands or fibres
extending throughout the gelled liquid. In some cases these fibres
can be observed by electron microscopy, although in other cases the
observation of the fibres which are believed to be present is
prevented by practical difficulties in preparing a suitable
specimen. When observed, the primary fibres in a gel are generally
thin (diameter less than 0.5 .mu.m, often less than 0.2 .mu.m) and
appear to have numerous branches or interconnections. Primary
fibres may entwine to form a thicker strand.
[0086] If these fibres are crystalline, they may or may not be the
same polymorph as macroscopic crystals obtained by conventional
crystallisation from a solvent.
[0087] One material which is well known to form such gels is
12-hydroxy stearic acid (12-HSA) which is discussed in Terech et al
"Organogels and Aerogels of Racemic and Chiral 12-hydroxy
octadecanoic Acid", Langmuir Vol. 10, 3406-3418, 1994. The material
is commercially available from Ajinomoto and also from Caschem.
[0088] U.S. Pat. No. 5,750,096 is one of several documents which
teaches that gelation can be brought about using esters or amides
of 12-hydroxy stearic acid. The alcohol used to form such an ester
or the amine used to form such an amide may contain an aliphatic,
cycloaliphatic or aromatic group with up to 22 carbons therein. If
the group is aliphatic it preferably contains at least three carbon
atoms. A cycloaliphatic group preferably contains at least five
carbon atoms and may be a fixed ring system such as adamantyl.
[0089] Other fatty acids with C.sub.8 or longer alkyl chains may be
used and amides thereof can also be used. A specific example is
lauric monoethanolamide also termed MEA lauramide.
[0090] N-acyl amino acid amides and esters are employable herein to
structure liquids. We have established that they do so by forming
fibrous networks. They are described in U.S. Pat. No. 3,969,087.
Examples of N-acyl amino acid esters include N.alpha., N.delta.,
dicaprylylornithine octyl, decyl, lauryl and stearyl ester,
N.alpha., N.epsilon., -dilauroyllysine hexyl, octyl, decyl, and
lauryl esters, N.alpha., N.epsilon.,-di(tallowyl) and N.alpha.,
N.epsilon.,-di(hydrogenated tallowyl) lysine hexyl, octyl, decyl,
and lauryl esters, in which tallowyl indicates the acyl radical of
tallow fatty acid.
[0091] Examples of N-acylamino acid amides include N-acetyl
glutamic acid- .alpha.,.gamma.-dilauryl and
.alpha.,.gamma.-distearyl amides; N-lauroyl glutamic acid diamide,
-.alpha.,.gamma.-dibutyl, -.alpha.,.gamma.-dihexyl- ,
-.alpha.,.gamma.-dioctyl, -.alpha.,.gamma.-dilauryl and
-.alpha.,.gamma.-distearyl amides; N-cocoyl glutamic acid,
-.alpha.,.gamma.-diamide, -.alpha.,.gamma.-dibutyl,
-.alpha.,.gamma.-dihexyl, -.alpha.,.gamma.-dioctyl,
-.alpha.,.gamma.-dilauryl and -.alpha.,.gamma.-distearyl amides;
N-hydrogenated tallowyl glutamic acid, -.alpha.,.gamma.-diamide,
-.alpha.,.gamma.-dibutyl, -.alpha.,.gamma.-dihexyl,
-.alpha.,.gamma.-dioctyl, -.alpha.,.gamma.-dilauryl and
-.alpha.,.gamma.-distearyl amides; N.alpha.,
N.epsilon.,-dicaproyllysine amide, butyl hexyl, octyl, lauryl, and
stearyl amides; N.alpha., N.epsilon.,-dicapryloyllysine amide,
butyl, dibutyl, hexyl, octyl, lauryl, and stearyl amides; N.alpha.,
N.epsilon.,-dilauroyllysine amide, butyl, hexyl, octyl, lauryl, and
stearyl amides; N.alpha., N.epsilon.,-dicocoyllysine amide, butyl
hexyl, octyl, lauryl, and stearyl amides; N.alpha.,
N.epsilon.,-di(hydrogenated tallowyl) lysine amide, butyl hexyl,
octyl, lauryl, and stearyl amides; N-lauroylvaline amide, butyl,
hexyl, octyl and lauryl amides; N-lauroyl-phenylalanine amide,
butyl, hexyl, octyl and lauryl amides; N-capryloyl leucine amide,
butyl, hexyl, octyl and lauryl amides; and N-palmitoylmethionine
amide, butyl, hexyl and octyl amides.
[0092] N-Lauroyl-L-glutamic acid di-n-butylamide is particularly
favoured and is commercially available from Ajinomoto under their
trade designation GP-1.
[0093] Further materials which have been disclosed as gelling
agents are the amide derivatives of di and tribasic carboxylic
acids set forth in WO 98/27954 notably alkyl N,N'dialkyl
succinamides.
[0094] Lanosterol, as disclosed in U.S. Pat. No. 5,635,165
mentioned above may suitably be used if the water-immiscible fluid
comprises a major fraction of silicone oils. Lanosterol has the
following chemical formula: 1
[0095] It is commercially available, e.g. from Croda Chemicals Ltd,
and as supplied it contains some dihydrolanosterol. This impurity
in the commercial material does not need to be removed.
[0096] A structurant which is the subject of a co-pending
application is a combination of a sterol and a sterol ester. In its
preferred form the sterol satisfies either of the two formula.
2
[0097] in which R represents an aliphatic, cycloaliphatic or
aromatic group, and preferably a linear or branched aliphatic
saturated or unsaturated hydrocarbon group. R desirably contains
from 1 to 20 carbons and preferably from 4 to 14 carbons.
[0098] It is particularly suitable to employ .beta.-sitosterol or
campesterol or cholesterol, or a hydrogenated derivative thereof,
such as dihydrocholesterol, or a mixture of two or more of them. An
especially preferred sterol is .beta.-sitosterol.
[0099] The preferred sterol ester is oryzanol, sometimes referred
to as .gamma.-oryzanol which contains material satisfying the
following formula: 3
[0100] The sterol and sterol ester are used in a mole ratio that is
normally selected in the range of from 10:1 to 1:10, especially
from 6:1 to 1:4 and preferably in the range of from 3:1 to 1:2.
Employment of the two system constituents within such a mole ratio
range, and especially within the preferred range facilitates the
co-stacking of the constituents and consequently facilitates the
formation of a network that is readily able to structure the
formulation.
[0101] Another structurant which is the subject of a co-pending
application and which may be used in this invention is an ester of
cellobiose and a fatty acid, preferably of 6 to 13 carbon atoms
especially 8 to 10 carbon atoms. Preferably the cellobiose is fully
esterified, or nearly so, and is in the .alpha.-anomeric form.
[0102] The structure of such a compound, in its .alpha.-anomeric
form is: 4
[0103] where R is an alkyl or alkenyl chain of 5 to 12 carbon atoms
so that the acyl group contains 6 to 13 carbon atoms. Particularly
preferred acyl groups incorporate a linear alkyl chain of 7 to 9
carbon atoms and are thus octanoyl, nonanoyl or decanoyl.
[0104] The acyl groups may have a mixture of chain lengths but it
is preferred that they are similar in size and structure. Thus it
is preferred that all of the acyl groups are aliphatic and at least
90% of the acyl groups have a chain length within a range such that
the shorter and longer chain lengths in the range differ by no more
than two carbon atoms, i.e. length in a range from m-1 to m+1
carbon atoms where m has a value in a range from 7 to 10.
[0105] Linear aliphatic acyl groups may be obtained from natural
sources, in which case the number of carbon atoms in the acyl group
is likely to be an even number or may be derived synthetically from
petroleum as the raw material in which case both odd and even
numbered chain lengths are available.
[0106] Synthetic methods for the esterification of saccharides are
well known. The esterification of cellobiose has been reported by
Takada et al in Liquid Crystals, (1995) Volume 19, pages 441-448.
This article gives a procedure for the production of the alpha
anomers of cellobiose octa-alkanoates by esterification of
.beta.-cellobiose using an alkanoic acid together with
trifluoracetic anhydride.
[0107] A further example of structurant which is the subject of a
co-pending application is compounds of the following general
formula (TI): 5
[0108] It is preferred that m is 2 so that the structurant
compounds comply with a general formula (T2): 6
[0109] The groups Y and Y.sup.1 will usually be identical, i.e.
both methylene or both carbonyl. The groups Q and Q.sup.1 may not
be the same but often will be identical to each other.
[0110] If m is 2 and Y and Y.sup.1 are methylene groups, the
compound is a derivative of threitol, which is
1,2,3,4-tetrahydroxybutane, while if m is 2 and Y and Y.sup.1 are
carbonyl groups, the compound is a diester of tartartic acid, which
is 2,3-dihydroxybutane-1,4-dioic acid.
[0111] It is preferred that each group Q and Q.sup.1 contains an
aromatic nucleus which may be phenyl or, less preferably, some
other aromatic group. Thus Q and Q.sup.1 may be groups of the
formula
Ar--(CH.sub.2).sub.n--
[0112] where Ar denotes an aromatic nucleus, notably phenyl or
substituted phenyl and n is from 0 to 10.
[0113] An aromatic nucleus (Ar) is preferably unsubstituted or
substituted with one or more substituents selected from alkyl,
alkyloxy, hydroxy, halogen or nitro.
[0114] One substituent may be an alkyl or alkyloxy group with a
long alkyl chain. Thus a formula (T3) for preferred structurants of
this invention can be given as: 7
[0115] in which
[0116] n=0 to 10, preferably 0 to 3, more preferably 1, 2 or 3;
[0117] Y=--CH.sub.2-- or >C=O
[0118] X.sub.1=H, Cl, Br, F, OH, NO.sub.2, O--R, or R, where R is
an aliphatic hydrocarbon chain with 1 to 18 carbon atoms.
[0119] X.sub.2 to X.sub.5 are each independently H, Cl, Br, F, OH,
NO.sub.2, OCH.sub.3, or CH.sub.3
[0120] In these formulae above, the central carbon atoms which bear
hydroxy groups are chiral centres. Thus if m=2, Y and Y.sup.1 are
the same and Q and Q.sup.1 are the same, the compounds will exist
as R,R and S,S optically active forms as well as an optically
inactive R,S form.
[0121] These compounds may be used as their optically active R,R or
S,S forms or as a mixture of the two--which may be a racemic
mixture.
[0122] Compounds within the general formula (TI) above are
available commercially. Also, syntheses of these compounds have
been given in scientific literature where the compounds were being
used as intermediates for purposes not related to the present
invention. Thus syntheses of threitol derivatives can be found
in:
[0123] Kataky et al, J. Chem Soc Perkin Trans vol. 2 page 321
[1990] Tamoto et al, Tetrahedron Vol. 40 page 4617 [1984], and
Curtis et al, J. C. S. Perkin I Vol. 15 page 1756 [1977].
[0124] Preparations of tartrate esters are found at:
[0125] Hu et al J. Am. Chem. Soc. Vol. 118, 4550 [1996] and Bishop
et al J. Org Chem Vol56 5079 [1991].
[0126] One structurant which it is eminently desirable to employ in
conjunction with a further structurant, be it wax or non-polymeric
fibre forming structurant is 12-hydroxystearic acid (abbreviated
herein to 12-HSA). It is especially desirable to employ a
combination of 12-HSA with either an N-acyl amino acid amide, or
with an alkyl alkanoate ester wax. The weight ratio of 12-HSA to
the N-acyl amino acid amide is often selected in the weight ratio
range of from 1:1 to 5:1. In such combinations, the weight of the
12-HSA is often chosen within the range of 3 to 8% by weight and
that of the N-acyl amino acid amide in the range of from 1 to 5% by
weight. The weight ratio of 12-HSA to the selected wax is often in
the range of 1:1 to 1:3. The weight of 12-HSA in such a combination
is often selected in the range of from 3 to 8% by weight and that
of the wax from 4 to 12% by weight.
[0127] Antiperspirant Actives
[0128] An essential constituent of an antiperspirant formulation is
an antiperspirant active. Antiperspirant actives are preferably
incorporated in an amount of from 0.5-60%, particularly from 5 to
30% or 40% and especially from 5 or 10% to 30 or 35% of the weight
of the composition.
[0129] Antiperspirant actives for use herein are often selected
from astringent active salts, including in particular aluminium,
zirconium and mixed aluminium/zirconium salts, including both
inorganic salts, salts with organic anions and complexes. Preferred
astringent salts include aluminium, zirconium and
aluminium/zirconium halides and halohydrate salts, such as
chlorohydrates.
[0130] Aluminium halohydrates are usually defined by the general
formula Al.sub.2(OH).sub.xQ.sub.y.wH.sub.2O in which Q represents
chlorine, bromine or iodine, x is variable from 2 to 5 and x+y=6
while wH.sub.2O represents a variable amount of hydration.
Especially effective aluminium halohydrate salts, known as
activated aluminium chlorohydrates, are described in EP-A-6739
(Unilever N V et al), the contents of which specification is
incorporated herein by reference. Some activated salts do not
retain their enhanced activity in the presence of water but are
useful in substantially anhydrous formulations, i.e. formulations
which do not contain a distinct aqueous phase.
[0131] Zirconium actives can usually be represented by the
empirical general formula: ZrO(OH).sub.2n-nzB.sub.z.wH.sub.2O in
which z is a variable in the range of from 0.9 to 2.0 so that the
value 2n-nz is zero or positive, n is the valency of B, and B is
selected from the group consisting of chloride, other halide,
sulphamate, sulphate and mixtures thereof. Possible hydration to a
variable extent is represented by wH.sub.2O. Preferable is that B
represents chloride and the variable z lies in the range from 1.5
to 1.87. In practice, such zirconium salts are usually not employed
by themselves, but as a component of a combined aluminium and
zirconium-based antiperspirant.
[0132] The above aluminium and zirconium salts may have
co-ordinated and/or bound water in various quantities and/or may be
present as polymeric species, mixtures or complexes. In particular,
zirconium hydroxy salts often represent a range of salts having
various amounts of the hydroxy group. Zirconium aluminium
chlorohydrate may be particularly preferred.
[0133] Antiperspirant complexes based on the above-mentioned
astringent aluminium and/or zirconium salts can be employed. The
complex often employs a compound with a carboxylate group, and
advantageously this is an amino acid. Examples of suitable amino
acids include dl-tryptophan, dl-.beta.-phenylalanine, dl-valine,
dl-methionine and .beta.-alanine, and preferably glycine which has
the formula CH.sub.3CH(NH.sub.2)CO.sub.2H.
[0134] It is highly desirable to employ complexes of a combination
of aluminium halohydrates and zirconium chlorohydrates together
with amino acids such as glycine, which are disclosed in U.S. Pat.
No. 3,792,068 (Luedders et al). Certain of those Al/Zr complexes
are commonly called ZAG in the literature. ZAG actives generally
contain aluminium, zirconium and chloride with an Al/Zr ratio in a
range from 2 to 10, especially 2 to 6, an Al/Cl ratio from 2.1 to
0.9 and a variable amount of glycine. Actives of this preferred
type are available from Westwood, from Summit and from Reheis.
[0135] Other actives which may be utilised include astringent
titanium salts, for example those described in GB 2299506A.
[0136] The proportion of solid antiperspirant salt in a composition
normally includes the weight of any water of hydration and any
complexing agent that may also be present in the solid active.
[0137] In the present invention, the composition takes the form of
a suspension in which antiperspirant active in particulate form is
suspended in the water-immiscible liquid carrier. Such a
composition does not have any separate aqueous phase present and
may conveniently be referred to as "substantially anhydrous"
although it should be understood that some water may be present
bound to the antiperspirant active or as a small amount of solute
within the water-immiscible liquid phase. In such compositions, the
particle size of the antiperspirant salts often falls within the
range of 0.1 to 200 .mu.m with a mean particle size often from 3 to
20 .mu.m. Both larger and smaller mean particle sizes can also be
contemplated such as from 20 to 50 .mu.m or 0.1 to 3 .mu.m.
[0138] Optional Ingredients
[0139] In addition to the ingredients listed above, the anhydrous,
topically-effective compositions of the present invention also can
include other optional ingredients that conventionally can be
included in topically applied cosmetic compositions. Optional
ingredients in compositions of this invention can include
disinfectants, for example at a concentration of up to about 10%
w/w. Suitable deodorant actives can comprise deodorant effective
concentrations of antiperspirant metal salts, deoperfumes, and/or
microbicides, including particularly bactericides, such as
chlorinated aromatics, including biguanide derivatives, of which
materials known as triclosan (Irgasan DP300.TM.), chlorhexidine and
Tricloban.TM., warrant specific mention. A yet another class
comprises biguanide salts such as available under the trade mark
Cosmosil.TM..
[0140] At the option of the manufacturer, and save as excluded
hereinbefore, inclusion of a polymeric structurant can be
contemplated. Polymeric structurants which can be employed can
comprise organo polysiloxane elastomers such as reaction products
of a vinyl terminated polysiloxane and a cross linking agent or
alkyl or alkyl polyoxyalkylene-terminated poly(methyl substituted)
or poly(phenyl substituted) siloxanes. Suitable elastomers have
been disclosed in for example WO 98/00097 and WO 98/18438. A number
of polyamides have also been disclosed as structurants for
water-immiscible liquids.
[0141] It is desirable to include within the formulation one or
more wash-off aids, often in a proportion of up to about 10% by
weight, especially up to about 5% by weight and particularly from
0.5 to 3% by weight based on the formulation.
[0142] Such wash off aids commonly comprise nonionic surfactants
and especially nonionic surfactants which contain a polyalkylene
oxide moiety, the residue of a fatty acid or fatty alcohol and
optionally the residue of an aliphatic polyhydric alcohol linking
group. Although, the surfactants may comprise a single fatty
residue, they preferably contain two residues. Preferably, the
surfactant is an ester surfactant, and especially a diester
surfactant. The polyalkylene oxide is often polyethylene oxide, or
polypropylene oxide or mixed polyethylene oxide/propylene oxide,
the polymer containing from 3 to 50 and especially from 5 to 20
alkylene oxide units. The fatty acid or alcohol often contains from
12 to 24 carbons, and in many instances is linear, examples
including 16, 18 or 22 linear carbons. Especially preferred
wash-off aids herein comprise polyethylene oxide diesters of fatty
alcohols containing 16 to 22 linear carbons, such as PEG-8
distearate.
[0143] One important class of optional constituents comprises
fragrances. They can be incorporated into the anhydrous,
topically-effective compositions in an amount of from 0% to about
5% and often from 0.2 to 1.5% by weight based on the total weight
of the composition. Fragrance-containing compositions of the
present invention, when applied to skin, fix a substantive
fragrance film on the skin that resists moisture, but that can be
removed by washing.
[0144] One other class of ingredients comprises moisturising agents
such as humectants. These include propylene glycol, sorbitol and
especially glycerol. Moisturising agents often comprise from 0 to
5% by weight of the formulation, and if employed, it is desirable
that the amount is chosen such that the agent is retained within
the carrier fluid.
[0145] Yet other optional ingredients that can be included in the
anhydrous composition of the present invention include, but are not
limited to, drying agents, like talc or DRY FLO (aluminium starch
octenylsuccinate); preservatives; and dyes. Generally, such
optional ingredients are present in a composition of the present
invention in an amount of about 10% or less by weight. In addition,
an organoclay can be included in a composition of the present
invention as an additional suspending agent in an amount of up to
20% by weight of the composition. An organoclay is potentially
helpful as an anti-caking agent to maintain a particulate
topically-effective compound homogeneously dispersed throughout the
composition. An exemplary organoclay is a quaternised three-layer
clay exfoliated with a polar solvent, like a quaternised
montmorillonite clay exfoliated with propylene carbonate. Such
clays are available under the trade name "Bentone". Other inorganic
materials which can be incorporated, for example as a thickener for
the formulation, comprise particulate silica, such as fumed silica,
suitably in an amount of up to 5%.
[0146] Still other cosmetic adjuncts can include:
[0147] skin feel improvers, such as talc (mentioned hereinabove) or
finely divided polyethylene, or glyceryl fatty esters, e.g.
glyceryl stearate, incorporated, for example, in an amount of up to
about 10% w/w;
[0148] skin benefit agents such as allantoin or lipids, for example
in an amount of up to 5% w/w; and
[0149] skin cooling agents, such as menthol and menthol
derivatives, often in an amount of up to 2% w/w.
[0150] Many of the stick formulations produced in accordance with
the present invention are opaque. However, it is possible to obtain
sticks having an appearance which is at least slightly translucent,
for example by so selecting the constituents of the carrier fluid
and the nature of the antiperspirant active that the refractive
index of the carrier fluid and dispersed solid differs by no more
than about 0.06, preferably employing antiperspirant active
particulates which lack substantial internal voids. Substantially
internal void-free actives can be obtained by milling
void-containing actives.
[0151] Whilst the ingredients disclosed herein are effective for
preparing the antiperspirant formulations of the instant invention,
prospective manufacturers should keep abreast of advances in
scientific understanding of their effect on humans and particularly
on skin before selling the resultant compositions for topical
application to skin.
[0152] The compositions described herein can be produced by
conventional processes for making suspension solid sticks. A
convenient process sequence for suspension antiperspirant
formulations comprises first mixing the structurant or mixture of
structurants, namely the wax(es), the non-polymeric fibre-forming
gellant(s) or a mixture of both with the carrier at a temperature
that is high enough to melt the structurant. Thereafter,
particulate antiperspirant active can be blended with the carrier
solution and the blend is formed into a solid mass by cooling, for
example by being introduced into its dispensing container at a
temperature that is often 5 to 10C above its normal setting
temperature. The process normally includes a suitable filling
process, such as a pour fill process (sometimes gravity -fed
injection) or injection at elevated pressure into a dispensing
container such as a barrel where it is cooled or allowed to cool to
ambient.
[0153] The compositions herein are suitable for applying topically
to human skin, and particularly antiperspirant compositions to
axillae, thereby reducing observable perspiration.
[0154] Product Packages
[0155] The compositions of this invention are structured liquids
which are firm in appearance. A composition of this invention will
usually be marketed as a product comprising a container with a
quantity of the composition therein, where the container has an
aperture for the delivery of composition, and means for urging the
composition in the container towards the delivery aperture.
Conventional containers take the form of a barrel of oval cross
section with the delivery aperture(s) at one end of the barrel. An
alternative cross section is round.
[0156] A composition of this invention is typically sufficiently
rigid that it is not apparently deformable by hand pressure. It is
suitable for use as a stick product in which a quantity of the
composition in the form of a stick is accommodated within a
container barrel having an open end at which an end portion of the
stick of composition is exposed for use. The opposite end of the
barrel is closed.
[0157] Generally the container will include a cap to cover its open
end and a component part which is sometimes referred to as an
elevator or piston fitting within the barrel and capable of
relative axial movement along it. In such packaging, the stick of
composition is accommodated in the barrel between the piston and
the open end of the barrel. The piston is used to urge the stick of
composition along the barrel. The piston and stick of composition
may be moved axially along the barrel by manual pressure on the
underside of the piston using a finger or rod inserted within the
barrel. Another possibility is that a rod attached to the piston
projects through a slot or slots in the barrel and is used to move
the piston and stick. Preferably the container also includes a
transport mechanism for moving the piston. One transport mechanism
comprises a threaded rod which extends axially into the stick
through a correspondingly threaded aperture in the piston, and
means mounted on the barrel for rotating the rod. Conveniently, the
rod is rotated by means of a hand-wheel mounted on the barrel at
its closed end, i.e. the opposite end to the delivery opening.
[0158] The component parts of such containers are often made from
thermoplastic materials, for example polypropylene or
polyethylene.
[0159] Having described the invention in general terms, specific
embodiments thereof will now be described in some detail by way of
example only.
[0160] List of Ingredients--Trade name, INCI name, supplier
[0161] 1) Syncrowax ERLC, C.sub.18-36 glycol esters (Croda)
[0162] 2) Castorwax MP80, hydrogenated castor oil (CasChem)
[0163] 3) Kesterwax K82H, C.sub.20-40 alkyl stearate (Koster
Keunen)
[0164] 4) Kesterwax K62, C.sub.16-22 alkyl stearate behenate
(Koster Keunen)
[0165] 5) Stearyl alcohol (Henkel)
[0166] 6) 12-hydroxystearic acid (CasChem)
[0167] 7) GP-1, N-lauryl-L-glutamic acid di-n-butyl amide
(Ajinomoto)
[0168] 8) AZAG 7167, Al/Zr tetrachlorohydrex glycine complex
(Summit)
[0169] 9) SuprafinoTalc, talc (Luzenac Inc)
[0170] 10) Finsolv TN, C12-15 Alkyl Benzoate (Finetex)
[RI=1.4841]
[0171] 11) DC245, cyclomethicone (Dow Corning Inc) [RI=1.3997]
[0172] 12) Fluid AP, PPG-14 Butyl Ether, (Amercol) [RI=1.4465]
[0173] 13) Silkflo 364 NF, polydecene (Albemarle) [RI=1.4544]
[0174] 14) DC704, tetramethyltetraphenyltrisiloxane (Dow Corning
Inc) [RI=1.5558]
[0175] 15) Eutanol G, octyldodecanol (Henkel) [RI=1.4538]
[0176] 16) Prisorine 3515, isostearyl alcohol (Unichema)
[RI=1.4559]
[0177] 17) C.sub.24-34 Montan Acid Wax (Clariant)
[0178] 18) AACH A418 (Summit)
[0179] 19) Glycerol (Aldrich) [RI=1.4725]
[0180] 20) Finsolv BOD, octyl dodecyl benzoate (Finetex)
[RI=1.4839]
[0181] 21) Finsolv SB, isostearyl benzoate (Finetex)
[RI=1.4860]
[0182] 22) Finsolv P, PPG-15 stearyl ether benzoate (Finetex) [RI
=1.4668]
[0183] 23) Finsolv TPP, mixture of C.sub.1215Alkyl
Benzoate/dipropylene glycol dibenzoate/PPG-15 stearyl ether
benzoate (Finetex) [RI=1.4915]
[0184] 24) Finsolv Expt 117-136, Experimental grade mixture of
C.sub.1215 Alkyl Benzoate/poloxamer 182 dibenzoate (Finetex)
[RI=1.4860] {poloxamer 182 dibenzoate is a dibenzyl ester of an
EO/PO block co-polymer}
[0185] 25) Mineral Oil, Sirius M70 (Dalton) [RI=1.4625]
[0186] 26) Kesterwax K80H, C20-40 alkyl stearate (Koster
Keunen)
[0187] 27) Reach 908, Al/Zr tetrachlorohydrex glycine complex
(Reheis)
[0188] 28) DC705, trimethypentaphenyltrisiloxane (Dow Corning) [RI
=1.5620]
[0189] 29) DM 7040, tetramethyltetraphenyltrisiloxane (Gelest)
[RI=1.5554]
[0190] 30) PDM 7050, trimethypentaphenyltrisiloxane (Gelest)
[1.5625]
[0191] 31) SP-C44 Ester Wax, Behenyl Behenate, (Strahl and
Pitsch)
[0192] 32) Cutina MD, Glyceryl stearate, (Henkel)
[0193] 33) Estol EO4DS 3724, PEG8 Distearate, (Unichema)
[0194] 34) Aerosil 200, Fumed Silica, (Degussa)
[0195] 35) SF1642, Silicone wax, (General Electric)
[0196] General Preparative Method
[0197] The preparations in Examples 1 to 4 and Comparisons CA to CB
were made by the general preparative route or by the modification
indicated below.
[0198] The structurant or structurants were weighed into a
round-bottomed flask or a beaker. The amounts of carrier oil(s)
were then weighed into the flask, and the mixture was stirred with
an overhead stirrer and heated using a isomantle or hotplate until
all of the structurant had dissolved. The source of heat was then
removed and the mixture left to cool to about 85.degree. C. While
still stirring the weighed amount of the particulate antiperspirant
active, and where appropriate other particulate materials,
including talc, was or were then added with stirring into the hot
mixture. The mixture was permitted to cool until its temperature
had reached about 10.degree. C. above the solidification
temperature of the formulation, judged either a trial run or on the
basis of experience with other formulations using the same
structurant(s), temperature sensitive ingredients such as the
perfume were added using a Pasteur pipette. The mixture continued
to be stirred and cool and was poured into stick barrels at
approximately 5.degree. C. above its normal solidification
temperature, i.e. solidification at 1 atmosphere pressure and
without being subjected to treatment which can alter the
solidification temperature. The sticks were then left to cool in
the laboratory and solidify. Characterisation was carried out when
the sticks had been stored at room temperature for at least 24
hours.
[0199] When using the foregoing general preparative process to make
Certain of the formulations containing ingredient 7, GP-1 as a
structurant, solidified prematurely when the antiperspirant solids
were introduced after the molten mixture had cooled to about
10.degree. C. above its normal solidification temperature, so that
for those formulations, the preparation was repeated, but adding
the antiperspirant to the molten mixture that was held at a
temperature above 85.degree. C.
EXAMPLE 1
Wax Structured Opaque Sticks
[0200] The formulations made in Example 1 and their properties are
summarised in Table 1 below.
[0201] CWS=Commercially available conventional white solid stick,
structured with waxes (stearyl alcohol+castor wax) employing a
mixture of volatile silicone oils as the principal carrier
fluid.
[0202] ISS=Commercially available solid stick with lower visible
deposits, structured with waxes (stearyl alcohol+castor wax) and
employing as carrier fluid a mixture of volatile silicone oils
(refractive index of about 1.4) with a non-volatile masking oil
(refractive index of below 1.465) (Fluid AP) at a weight ratio of
about 4:1.
[0203] nm=measurement not made
[0204] Comp CA: Stick cracked and fell apart, so that no
characterisation measurements could be made.
2TABLE 1 Comp Comp Comp Comp Ex Ex Ex Ex CWS ISS CA CB 1.1 1.2 1.3
1.4 Syncrowax (1) Castorwax (2) 4.5 4.5 5 4 3 4.5 K82H (3) 13.5
13.5 15 12 9 13.5 AZAG 7167 (8) 24 24 24 24 24 24 Finsolv TN 11.4
22.8 55 59 63 57 (10) DC245 (11) 45.6 34.2 Perfume 1 1 1 1 1 1
Penetrometer 9.8 6.8 nm 11.2 6.5 8.7 11.1 8.3 Hardness (mm)
Whiteness on 165.5 42.7 nm 50.7 15.5 19.3 22.2 16.3 Black Wool
Whiteness 131.0 60.2 nm 40.1 32.3 29.1 36.3 28.6 grey abrasive
paper Ex Ex Ex Ex Ex Ex Ex Ex 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12
Syncrowax (1) 15 Castorwax (2) 4.5 4.5 4.5 4.5 4.5 4.5 4 5 K82H (3)
13.5 13.5 13.5 13.5 13.5 13.5 12 AZAG 7167 (8) 24 24 24 24 24 24 24
24 Finsolv TN (10) 45.6 39.9 34.2 28.5 45.6 45.6 47.2 55 DC245 (11)
11.4 17.1 20.8 28.5 11.8 Fluid AP (12) 11.4 Silkflo 364NF 11.4 (13)
Perfume 1 1 1 1 1 1 1 1 Penetrometer 8.8 8.5 8.9 9.3 6.0 7.4 8.2
8.0 Hardness (mm) Whiteness on 16.1 20.1 18.7 20.3 20.6 23.3 20.6
14.5 Black Wool Whiteness grey 37.2 37.3 32.9 31.4 33.4 32.5 36.7
31.2 abrasive paper Ex Ex Ex Ex Ex Ex Ex Ex 1.13 1.14 1.15 1.16
1.17 1.18 1.19 1.20 Syncrowax (1) 12 9 13.5 13.5 13.5 13.5 13.5
13.5 Castorwax (2) 4 3 4.5 4.5 4.5 4.5 4.5 4.4 AZAG 7167 (8) 24 24
24 24 24 24 24 24 Finsolv TN (10) 59 63 57 45.6 39.9 45.6 45.6 55
DC245 (11) 11.4 17.1 Fluid AP (12) 11.4 Silkflo 364NF 11.4 (13)
Talc (9) 1 Perfume 1 1 1 1 1 1 1 1 Penetrometer 8.7 11.2 8.7 9.2
9.7 9.8 9.4 8.7 Hardness (mm) Whiteness on 16.8 16.2 15.8 16.6 14.3
15.1 15.7 14.0 Black Wool Whiteness on 31.7 29.9 28.6 32.0 32.6
30.1 30.2 29.7 grey abrasive paper Ex Ex Ex Ex Ex Ex Ex Ex 1.21
1.22 1.23 1.24 1.25 1.26 1.27 1.28 Castorwax (2) 4.5 6 6 4.5 4.5
4.5 4 4.5 K82H (3) 13.5 13.5 13.5 13.5 Stearyl Alcohol 15 15 (5)
K80H (26) 12 13.5 AZAG 7167 (8) 24 24 24 24 24 24 AZAG 908 (27) 24
24 Finsolv TN (10) 55 54 37.8 28.5 59 28.5 DC245 (11) 16.2 28.5
28.5 DC704 (14) 57 28.5 28.5 Talc (9) 1 Perfume 1 1 1 1 1 1 1 1
Penetrometer 8.4 9.2 10.0 3.6 4.8 7.7 11.8 14.6 Hardness (mm)
Whiteness on 18.8 18.6 17.6 15.0 14.9 16.2 21.7 21.2 Black Wool
Whiteness on 28.6 35.3 34.9 36.9 38.7 33.5 26.6 32.3 grey abrasive
paper Ex Ex Ex Ex Ex Ex Ex Ex 1.29 1.30 1.31 1.32 1.33 1.34 1.35
1.36 Syncrowax (1) 13.5 13.5 13.5 13.5 13.5 Castorwax (2) 4 3 4.5
4.5 4.5 4.5 4.5 4.5 K82H (3) 13.5 K80H (26) 12 9 AZAG 7167 (8) 24
24 24 24 24 24 24 24 Finsolv TN (10) 28.5 55 Finsolv BOD (20) 59
Finsolv SB (21) 57 Finsolv TPP (22) 57 Finsolv P (23) 57 Finsolv
Expt 1 57 117-136 (24) Mineral Oil (25) 28.5 DC245 (11) 12.0 DC704
(14) 63 Glycerol (19) 25.2 2 Perfume 27.8 1 1 1 1 1 1 1
Penetrometer 12.0 9.6 14.1 15.2 9.5 13.5 13.0 9.6 Hardness (mm)
Whiteness on 25.2 18.9 21.7 20.3 22.5 23.0 22.2 12.2 Black Wool
Whiteness on 27.8 29.1 29.6 31.9 33.5 30.5 35.5 31.6 grey abrasive
paper Ex Ex Ex Ex Ex Ex Ex 1.37 1.38 1.39 1.40 1.41 1.42 1.43
Syncrowax (1) 13.5 Castorwax (2) 4 4 4.5 3 3 3 3 K82H (3) 12 12
K80H (26) 9 9 9 9 AZAG 7167 (8) 24 24 24 24 24 24 24 Finsolv TN
(10) 29.5 31.5 Finsolv BOD (20) 59 57 DC245 (11) 29.5 DC705 (28) 63
31.5 PDM 7040 (29) 63 PDM 7050 (30) 63 Perfume 1 1 1 1 1 1 1
Penetrometer 17.7 10.7 13.9 4.9 9.7 6.9 5.6 Hardness (mm) Whiteness
on 15.9 23.8 20.6 15.3 13.4 13.3 17.5 Black Wool Whiteness on 31.7
27.4 28.2 25.8 27.6 31.9 28.2 grey abrasive paper Ex Ex Ex Ex Ex Ex
1.44 1.45 1.46 1.47 1.48 1.49 Castorwax (2) 12 10 8 6 4.0 K80H (26)
4 6 8 10 16 SP-C44 Ester Wax 17.5 (31) AZAG 7167 (8) 24 24 24 24 24
AZAG 908 (27) 24.0 Finsolv TN (10) 59 59 59 59 59 47 DC245 (11) 6.5
Perfume 1 1 1 1 1 1 Penetrometer 10.6 9.1 9.6 9.8 6.7 9.2 Hardness
(mm) Whiteness on 15.4 15.0 16.6 18.0 18.0 25.0 Black Wool
Whiteness on 25.0 28.2 25.0 27.4 30.8 35.6 grey abrasive paper
[0205] Sticks Ex 1.1 to Ex 1.49 all left virtually no white
deposits when applied to skin. By comparison, the sticks of
commercial Comparisons CA and CB, and formulations outside the
scope of the present invention showed significantly inferior
visible deposits or were physically not able to be tested.
EXAMPLE 2
Opaque Sticks Structured with a Non-polymeric Fibre-forming Gellant
Alone or With a Wax
[0206] The formulations and resultant properties of sticks made in
Example 2 are summarised in Table 2 below.
3TABLE 2 Ex Ex Ex Ex Ex Ex Ex Ex Ex 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8
2.9 12-HSA (6) 6 6 6 6 6 6 6 6 GP-1 (7) 6 K62 (4) 8 8 8 8 K82H (3)
8 8 8 8 AZAG 7167 (8) 24 24 24 24 24 24 24 24 24 Finsolv TN 61 34.9
48.8 36.6 61 48.8 42.7 36.6 55.2 (10) DC245 (11) 6.1 12.2 24.4 12.2
18.3 24.4 Eutanol G 13.8 (15) Perfume 1 1 1 1 1 1 1 1 1
Penetrometer 10.4 12.9 11.1 11.7 9.8 9.4 10.1 10.5 16.5 Hardness
(mm) Whiteness on n/d 24.4 21.8 24.9 22.1 22.1 21.5 23.3 21.3 Black
Wool Whiteness on n/d 32.6 33.6 35.6 31.2 33.4 34.5 33.3 23.1 grey
abrasive paper Ex Ex Ex Ex Ex Ex Ex Ex Ex 2.10 2.11 2.12 2.13 2.14
2.15 2.16 2.17 2.18 12-HSA (6) 6 4 GP-1 (7) 2 6 6 Montan Acid 6 3
Wax (17) K82H (3) 10 10 10 8 8 AZAG 7167 (8) 24 24 25 25 24 24 24
24 24 Finsolv TN 53.6 66.0 65 60 47.2 41.3 35.4 59 (10) Finsolv BOD
61 (20) Prisorine 9 3515 (16 Eutanol G 13.4 (15) Perfume 1 1 1 1 1
1 1 Penetrometer 11.8 13.5 10.3 17.6 8.8 8.8 10.0 7.7 7.1 Hardness
(mm) Whiteness on 20.3 18.8 16.6 19.1 15.0 14.8 14.8 23.1 15.1
Black Wool Whiteness on 28.1 30.6 30.7 32.8 nm nm nm nm 35.1 grey
abrasive paper
[0207] The sticks obtained in Example 2.1 to 2.18 each left
virtually no white deposits when applied to skin.
EXAMPLE 3
Non-opaque Sticks
[0208] The formulations and resultant properties of sticks made in
Example 3 are summarised in Table 3 below.
4 TABLE 3 Ex 3.1 Ex 3.2 Ex 3.3 Ex 3.4 Ex 3.5 Ex 3.6 12-HSA (6) 10 6
6 GP-1 (7) 6 6 6 2 2 AZAG 7167 24 24 (8) AACH A418 20 20 20 20 (18)
Finsolv TN 70 74 64 67 20.4 (10) Prisorine 10 7 3515 (16) Eutanol G
(15) 13.6 DC704 (14) 47.6 54.4 RI AP Active 1.534 1.534 1.534 1.534
1.562 1.562 RI Solvent 1.4841 1.4841 1.4803 1.4814 1.5343 1.5312
Penetrometer 11.9 12.9 Nm 12.5 3.6 10.4 Hardness (mm) Whiteness on
nm 16.3 Nm 16.2 16.0 18.0 Black Wool Whiteness nm 32.7 Nm 35.8 26.5
26.6 on grey abrasive paper
[0209] All of the sticks made in Example 3.1 to 3.6 were all
slightly translucent in appearance and left virtually no white
deposits when applied to skin.
EXAMPLE 4
[0210] Further wax-structured sticks were made in accordance with
the general procedure of Example 1 and as summarised in Table 4
below (n/d=test not carried out).
5TABLE 4 Ex Ex Ex Ex Ex Ex Ex 4.1 4.2 4.3 4.4 4.5 4.6 4.7 K82H (3)
10.4 10.4 10.4 10.4 16 6 6 K62 (4) 5.6 5.6 5.6 5.6 6 6 Stearyl
alcohol (5) 2 2 2 2 2 2 Silicone wax (35) 2 2 AZAG 908 (27) 24 24
24 24 24 24 24 Finsolv TN (10) 57 24 26 56.5 56.5 61 59 Glyceryl
Stearate (32) 5.6 5.6 PEG-8 Distearate (33) 2 DC245 (11) 24 24
Silica (34) 0.5 0.5 Perfume 1 1 1 1 1 1 1 Properties Penetrometer
Hardness 4.5 n/d n/d 5.8 5.2 6.2 8.6 (mm) Whiteness on Black 18.0
20.1 19.5 18.4 16.2 15.2 15.1 Wool (24 hrs) Whiteness on grey 32.4
31.3 31.3 33.1 34.0 32.5 32.2 Wet or Dry paper (24 hrs)
[0211] Measurement of Properties
[0212] i) Hardness of a Stick using a Penetrometer
[0213] The hardness and rigidity of a composition which is a firm
solid can be determined by penetrometry.
[0214] A suitable procedure is to utilises a lab plant PNT
penetrometer equipped with a Seta wax needle (weight 2.5 grams)
which has a cone angle at the point of the needle specified to be
9.degree.10'.+-.15'. A sample of the composition with a flat upper
surface is used. The needle is lowered onto the surface of the
composition and then a penetration hardness measurement is
conducted by allowing the needle with its holder to drop under a
total weight, (i.e. the combined weight of needle and holder) of 50
grams for a period of five seconds after which the depth of
penetration is noted. Desirably the test is carried out at a number
of points on each sample and the results are averaged. Utilising a
test of this nature, an appropriate hardness for use in an
open-ended dispensing container is a penetration of less than 30 mm
in this test, for example in a range from 2 mm to 30 mm. Preferably
the penetration is in a range from 5 mm to 20 mm.
[0215] In a specific protocol for this test measurements on a stick
were performed in the stick barrel. The stick was wound up to
project from the open end of the barrel, and then cut off to leave
a flat, uniform surface. The needle was carefully lowered to the
stick surface, and then a penetration hardness measurement was
conducted. This process was carried out at six different points on
the stick surface. The hardness reading quoted is the average value
of the 6 measurements.
[0216] ii) Deposition and Whiteness of Deposit
[0217] Deposition
[0218] Another test of the properties of a composition is the
amount of the composition which is delivered onto a surface when
the composition is drawn across that surface (representing the
application of a stick product to human skin). To carry out this
test of deposition, a sample of the composition with standardised
shape and size is fitted to apparatus which draws the sample across
a test surface under standardised conditions. The amount
transferred to the surface is determined as an increase in the
weight of the substrate to which it is applied. If desired the
colour, opacity or clarity of the deposit may subsequently be
determined.
[0219] A specific procedure for such tests used apparatus to apply
a deposit from a stick onto a substrate under standardised
conditions and then measures the mean level of white deposits using
image analysis.
[0220] The substrates used were
[0221] a: 12.times.28 cm strip of black Worsted wool fabric.
[0222] b: 12.times.28 cm strip of grey abrasive paper (3M.TM. P800
WetorDry.TM. Carborundum paper)
[0223] The substrates were weighed before use. The sticks were
previously unused and with domed top surface unaltered.
[0224] The apparatus comprised a flat base to which a flat
substrate was attached by a clip at each end. A pillar having a
mounting to receive a standard size stick barrel was mounted on an
arm that was moveable horizontally across the substrate by means of
a pneumatic piston.
[0225] Each stick was kept at ambient laboratory temperature
overnight before the measurement was made. The stick was advanced
to project a measured amount from the barrel. The barrel was then
placed in the apparatus and a spring was positioned to biased the
stick against the substrate with a standardised force. The
apparatus was operated to pass the stick laterally across the
substrate eight times. The substrate was carefully removed from the
rig and re-weighed.
[0226] Whiteness of Deposit
[0227] The deposits from the previous test were assessed for their
whiteness after an interval of 24 hours approximately.
[0228] This was done using a Sony XC77 monochrome video camera with
a Cosmicar 16 mm focal length lens positioned vertically above a
black table illuminated from a high angle using fluorescent tubes
to remove shadowing. The apparatus was initially calibrated using a
reference grey card, after the fluorescent tubes had been turned on
for long enough to give a steady light output. A cloth or
Carborundum paper with a deposit thereon from the previous test was
placed on the table and the camera was used to capture an image. An
area of the image of the deposit was selected and analysed using a
Kontron IBAS image analyser. This notionally divided the image into
a large array of pixels and measured the grey level of each pixel
on a scale of 0 (black) to 255 (white). The average of the grey
intensity was calculated. This was a measure of the whiteness of
the deposit, with higher numbers indicating a whiter deposit. It
was assumed that low numbers show a clear deposit allowing the
substrate colour to be seen.
[0229] Refractive Index
[0230] The refractive index of a liquid was measured using a
standard refractometer at 22.degree. C.
[0231] The refractive index of a particulate solid was measured at
22.degree. C. using a comparative method in which the particulate
material was suspended in a range of fluids of known refractive
index, and the mixture which gave the highest clarity to the eye of
a skilled person was taken to be the refractive index of the
particulate solid.
EXAMPLE 4
[0232] Further wax-structured sticks were made in accordance with
the general procedure of Example 1 and as summarised in Table 4
below.
6 Ex Ex Ex Ex Ex Ex Ex 4.1 4.2 4.3 4.4 4.5 4.6 4.7 K82H (3) 10.4
10.4 10.4 10.4 16 6 6 K62 (4) 5.6 5.6 5.6 5.6 6 6 Stearyl alcohol
(5) 2 2 2 2 2 2 Silicone wax (35) 2 2 AZAG 908 (27) 24 24 24 24 24
24 24 Finsolv TN (10) 57 24 26 56.5 56.5 61 59 Glyceryl Stearate
5.6 5.6 (32) PEG-8 Distearate 2 (33) DC245 (11) 24 24 Silica (34)
0.5 0.5 Perfume 1 1 1 1 1 1 1 Properties Penetrometer 4.5 n/d n/d
5.8 5.2 6.2 8.6 Hardness (mm) Whiteness on Black 18.0 20.1 19.5
18.4 16.2 15.2 15.1 Wool (24 hrs) Whiteness on grey 32.4 31.3 31.3
33.1 34.0 32.5 32.2 Wet or Dry paper (24 hrs)
* * * * *