Note: Descriptions are shown in the official language in which they were submitted.
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~03965S
1 BACKGROUND OF THE INVENTION
1 Field of the Invention
'
The present invention relates generally to an excellent
cosmetic and more particularly it relates to a cosmetic con-
taining as the base the saturated hydrocarbons obtained from
a synthetic polyisoprene rubber.
An object of this invention is to provide an excellent
base for cosmetics, which can be used in place of natural
squalane.
2. Description of the Prior Art
,~ .
Squalane is obtained by reducing squalane which is
recovered from shark liver oil, etc., and is widely used as
bases for cosmetics. However, since natural squalane has a
specific odor, which increases in strength during the storage
of the material degrading the quality of cosmetic, and since it
is a natural product the supply varies widely, the discovery of
substitutes for squalane has been desired.
A process of producing a substitute for squalane by
polymerizing dipentene is disclosed in the specification of
Japanese Patent Publication No. 11,446/'63 but the yield of
the polymer obtained by the process is only about 24~ to the raw
material dipentene and thus such a process is economically dis-
advantageous.
SUMMARY OF THE INVENTION
Therefore, various investigations for discovering a -
substitute for squalane have been made and as the result thereof
it has been discovered that the saturated hydrocarbons obtained
by reducing the hydrocarbons formed by the thermal decomposition
of a synthetic polyisoprene rubber have properties similar to
~39655
1 that of squalane and also are quite excellent as bases for
cosmetics and that in addition these saturated hydrocarbons
are obtained with a high yield of about 65%.
Therefore, according to the present invention there is
provided a cosmetic base comprising the saturated hydrocarbons
prepared by subjecting a synthetic polyisoprene rubber to a
thermally destructive distillation under a reduced pressure, -~
fractionally distilling the distillate thus obtained to provide
a fraction boiling at 155 to 240C/l mmHg, and then catalytically
reducing the fraction and a cosmetic composition including
the cosmetic base.
DETAILED DESCRIPTION OF THE INVENTION
A synthetic polyisoprene rubber is a synthetic rubber
similar to natural rubber and having 92 to 97% cis-type double
bonds prepared by polymerizing isoprene in the presence of a
Ziegler catalyst or a lithium-type catalyst and recently such
a synthetic polyisoprene rubber has become commercially
available easily and at a low cost.
It is well known that low-polymer hydrocarbons are
obtained by thermally decomposing natural rubber and, in
particular, as a method of thermally decomposing natural rubber
under a reduced pressure, a method is reported in which natural
rubber is subjected to a thermally destructive distillation
under a pressure of 0.1 mmHg to provide a distillate fraction
in an amount of 63.5% and a resinous material in an amount of
36.5~ as disclosed in Staudinger & Fritschi; Helv. Chim. Acta.;
Vol. 5, 785 (1922). :
The thermal decomposition of natural rubber has also
been investigated and almost the same results as those obtained
by Staudinyer et al have been obtained. That is, by the thermal
~039655
1 decomposition, a distillate in an amount of 60% and a resinous
material in an amount of 40% were obtained but the content of
the hydrocarbons having 25 to 35 carbon atoms in the dis-
tillate was only 20%. Furthermore, the hydrocarbons have a bad
odor caused by impurities such as protein, etc., contained in
the natural rubber raw material and the removal of the bad odor -
was quite difficult. On the other hand, it has been found that
when a synthetic polyisoprene rubber is thermally decomposed,
the product is composed of almost 100% distillate and contains
almost no resinous material, the content of the hydrocarbons
having 25 to 35 carbon atoms in the;distillate is about 65%,
the hydrocarbons have less of a bad odor, and further the
reduction product of the hydrocarbons is a colorless oil having
a fragrance and have no unstable color and odor as is the ~
situation with natural squalane. -
The polyisoprene rubber as used in this invention has
92 to 97% cis-type double bonds, has a degree of polymerization
of about 220,000 and has the following general formula for ~-
repeating units contained in the polyisoprene rubber;
IC 3 ;
[ CH2 - C = CH - CH2 ]n
wherein n is about 220,000. Typical commercial examples of
the synthetic polyisoprene rubber are"IR2200", which is a common
trademark of Japan Synthetic Rubber Co., Ltd., Kuraray Co., Ltd.,
Nippon Zeon Co., Ltd., etc. The synthetic polyisoprene rubber
can be prepared as described in F.W. Stravely, Industrial and
Engineering Chemistry 48, No. 4, 778-783 (1956), etc. by poly-
merizing isoprene in the presence of a Ziegler type catalyst
or a lithium-type catalyst.
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1'039655
1 The saturated hydrocarbons used in this invention can
be obtained using the process described in Canadian patent
application serial number 213,438, filed on November 12, 1974, :.
in which small pieces of synthetic polyisoprene rubber are
uniformly heated to temperatures of about 300 to 400C, preferably
340 to 350C, under a pressure of about 0.1 to 5 mmHg, preferably
0.1 to 1.0 mmHg. The thermally distructive distillation can be
suitably accomplished for about 30 minutes at about 350C when
1 kg of the starting material rubber is used. Then, by distllling
the distillate thus obtained and collecting a fraction boiling
at 155 to 240C/l.mmHg, hydrocarbons having about 25 to 35 carbon
atoms are obtained. Subsequently, by catalytically reducing
the hydrocarbons under normal pressure-or at high pressure
using hydrogen in the presence of a catalyst such as palladium,
nickel, platinum, etc., using a conventional catalytic reduction
method, the saturated hydrocarbons are obtained. The catalytic
reduction is generally conducted at about room temperature
(e.g., 20 to 30& ) to about 300C. When palladium and platinum
are used as catalyst, a suitable temperature generally
20 ranges from about room temperature to about 100C, and, when :
nickel is used as catalyst, a suitable temperature generally
ranges from about 100 to about 300Cj preferably about 250C. .
A suitable amount of the catalyst generally ranges from about 3
to 10% by weight based on the raw materials. When nickel is
used as a catalyst, the reaction generally is completed in about
5 to 10 hours at about 250C.
The detailed chemical structures of the saturated hydro-
carbons have not yet been determined but are as.sumed to have
structures similar to chain terpene compounds formed by the 1,4-
bond of isoprene. Moreover, since squalane is a chain terpene
-- 4 --
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1(039655
1 compound having isopropyl groups at the both ends of the
molecule, it may be considered that the properties of the saturated
hydrocarbons quite resemble the properties of squalane but
as the result of experiments, it has been confirmed that the
saturated hydrocarbons are similar to squalane in fluidity as a
base for cosmetics, but in addition the oily feeling, solubility
and emulsification are superior to squalane in the point that
they exhibit no irritation to skin and that they are quite
stable. Also, the saturated hydrocarbons used in this invention
are stable as to raw material sources and cost and the industrial
significance as the bases for cosmetics is quite important. For
example, the cosmetic base of this invention can be widely
employed as an oil base in compositions such as cold creams,
tissue creams, hygienic creams, nourishing creams, hand creams,
massage creams, modern face creams, cleansing creams, shaving
creams, after-shaving creams, sunburn preventives, sun tan oils, -
lipsticks, foundation sticks, etc. It is to be emphasiæed that
the utility of the cosmetic base of this invention is not
limited to these examples.
The properties of the saturated hydrocarbons used in
this invention are shown in the following table together with
those of squalane.
TABLE 1
:.
Property Saturated Saturated Squalane
Hydrocarbon Hydrocarbon
(mainly C30) (C25 C35)
Boiling Point
(1 mmHg) 195-215 155-240 205-215
Gravity ( 20) 0.8988 0.8729 0.8106
Freezing Point * about -70C about -70C about -55C
Iodine Value 0 0 0
(*): Simple measurement in an acetone-dry ice bath.
1~3965S
1 The following reference example shows an embodiment of
the process of producing the saturated hydrocarbons used in
this invention.
REFERENCE EXAMPLE
In a decomposition flask were charged 100 g of small
pieces of a synthetic polyisoprene rubber and after displacing
the inside atmosphere of the flask with nitrogen and evacuating
the flask, the polyisoprene rubber was heated to 340 to 350C
under a pressure of 0.1 mmHg, whereby the deccmposition began
in 17 minutes and 100 g of a decomposed oil was obtained 13
minutes later. In this case almost no residue was observed in
the flask. By fractionally distilling the decomposed oil
under a reduced pressure, 65 g of a fraction boiling at 155 to
240C/l mmHg was obtained. The fraction thus obtained was
subjected to a hydrogenation in an autoclave at a temperature
of 100C and at a hydrogen pressure of 100 kg/cm2 in the
presence of 10 g of Raney nickel. The hydrogenation was finished
after two hours. Then, the hydrogenated oil was cooled, with-
drawn from the autoclave, and after removing the catalyst by
20filtration, was distilled under a reduced pressure to provide
63 g of saturated hydrocarbons. The properties of these hydro-
carbons were the same as those shown in Table 1.
The invention is illustrated in greater detail by
reference to the following examples.
EXAMPLE 1
Preparation of Cold Cream (w/o type)
%
Beeswax 12.0
Lanolin 3.0
Vaseline 10.0
Saturated Hydrocarbons of This Invention 38.0
Solid Paraffin 7.0
1~39655
1 Sorbitan Sesquioleate 3.8
Polyoxyethylene Sorbitan Sesquioleate 0.2
Distilled Water 25.5
Perfume 0.5
Antioxidant and Antiseptic Suitable amounts
Distilled water was heated to 70C. A mixture of the -
other components shown above was melted by heating and maintained
at 70C. Distilled water was gradually added to the molten
mixture and emulsified. Then, the mixture was cooled under
stirring, placed in a vessel at 40C and allowed to cool to
provide a cold cream. -
EXAMPLE 2
Preparation of Foundation Stick:
% ~:~
Saturated Hydrocarbons of This
Invention 25.0
Carnauba Wax 7.0
Solid Paraffin lO.0
Isopropyl Myristate 5.0
Sorbitan Sesquioleate 3.0
Powdered Coloring Matter 50.0
Perfume Suitable amounts
Antioxidant Suitable amounts -
The saturated hydrocarbons of this invention were mixed
with isopropyl myristate and after adding thereto sorbitan
sesquioleate and the powdered coloring matter, the mixture was
mixed well. A mixture of carnauba wax and solid paraffin was
melted by heating and after uniformly dispersing the oily
mixture prepared above in the molten mixture, the mixture was
stirred well and solidified by quenching in a mold to provide a
foundation stick.
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~39f~55
1 EXAMPLE 3
Preparation of Sun Tan Oil:
Saturated Hydrocarbons of This Invention 60
Olive Oil 37
Ultraviolet Absorbent 3
Antioxidant Suitable amounts
Perfume Suitable amounts
These components were mixed well to provide a sun tan
oil.
While the invention has been described in detail and
with reference to specific embodiments thereof, it will be
apparent to one skillèd in the art that various changes and
modifications can be made therein without departing from the
spirit and scope thereof.
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