Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
1996-02-26
2001-10-09
Venkat, Jyothsna (Department: 1627)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C558S208000, C558S209000, C558S210000, C558S213000
Reexamination Certificate
active
06299887
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to phosphoric triesters which have remarkable compatibility with skin, have excellent feel during use, and are mild to the skin. The invention also relates to external compositions containing the triesters as well as to a method for effectively preparing asymmetric phosphoric triesters.
2. Description of Related Art
Liquid oils are very important and indispensable to cosmetic bases. In addition to performing essential functions such as imparting lubricity to the skin, exhibiting barrier functions by forming hydrophobic films, and suppressing transdermal loss of moisture, liquid oils today are required to 1) be compatible with the skin, 2) provide good sensation when applied to the skin, and 3) be safe to the skin.
In order to meet these requirements, a diversity of new liquid oil bases have been developed and applied in various ways. For example, triglycerides such as squalane, olive oil, etc. are used as sebum analogs for the purpose of providing skin compatibility. Synthetic ester oils such as isopropyl palmitate and isopropyl myristate as well as silicone oils are used to provide the skin with good sensation, due to their low viscosity.
However, these conventional oil bases are problematic in that those having higher polarities which generally accounts for higher skin compatibility tend to have stronger intermolecular forces, resulting in disagreeable sensations, e.g., stickiness, to the skin. Particularly, when ester oils and triglycerides are used, they tend to decompose and cause safety problems, as their compatibility with the skin is enhanced. Moreover, oil bases having low molecular weights also involve crucial problems in safety, although they have relatively good sensation and compatibility with the skin.
On the other hand, lower trialkyl phosphoric esters are already widely used as additives such as plasticizers and stabilizers, as lubricants, or as dispersants due to their excellent characteristics. They are liquid at ambient temperatures, chemically stable, and low in cloud point. They have polarity as well as excellent dissolvability, compatibility, miscibility, and pigment-dispersing ability. However, they are not necessarily satisfactory in terms of safety to the skin. Higher trialkyl esters are reliable in safety, but lack in good sensation as they have high viscosities or high melting points.
As described above, no conventional oil bases meet the following requirements simultaneously: 1) high compatibility with the skin, 2) good sensation during use, and 3) safety to the skin. Thus, liquid oils which fulfill these criteria are still desired.
Under the above circumstances, the present inventors have conducted extensive studies, and have found that the phosphoric triesters represented by the formula (1) described below having certain ester residues have high polarity, excellent compatibility with the skin, low viscosity, and low melting points, and also provide a high degree of safety. The present inventors have also found that compositions containing the phosphoric triesters as liquid oils have excellent compatibility with the skin, good sensation during use, and are very safe. Moreover, in the course of researching of methods for synthesizing these phosphoric triesters, the present inventors have discovered an effective method for preparing asymmetric phosphoric triesters.
SUMMARY OF THE INVENTION
Accordingly, in one aspect of the present invention, there is provided a phosphoric triester represented by the following formula (1):
wherein R
1
represents C12-C24 linear or branched alkyl or alkenyl, R
2
represents C6-C24 linear, branched, or cyclic alkyl, C6-C24 linear alkenyl, or aryl, and R
3
represents C1-C6 linear, branched, or cyclic alkyl, C2-C6 alkenyl, or aryl.
In another aspect of the present invention, there is provided an external composition comprising a phosphoric triester represented by the following formula (1):
wherein R
1
represents C12-C24 linear or branched alkyl or alkenyl, R
2
represents C6-C24 linear, branched, or cyclic alkyl, C6-C24 linear alkenyl, or aryl, and R
3
represents C1-C6 linear, branched, or cyclic alkyl, C2-C6 alkenyl, or aryl.
In a further aspect of the present invention, there is provided a method for preparing an asymmetric phosphoric triester comprising the step of adding an alkyl phosphoric halide represented by the following formula (2):
wherein R
4
represents C1-C36 linear or branched alkyl or C2-C36 alkenyl, A
1
represents C2-C3 linear or branched alkylene, “a” denotes the average addition mol number of alkylene oxide representing a number from 0 to 20 inclusive, wherein the A
1
s in the number of “a” may be identical or different from one another, X is a halogen atom or a group represented by R
5
(OA
2
)
b
O— (wherein R
5
is C1-C36 linear or C2-C36 branched alkyl or alkenyl, R
4
and R
5
are the same or different from one another, A
2
represents C2-C3 linear or branched alkylene group, “b” denotes the average addition mol number of alkylene oxide representing a number from 0 to 20 inclusive, wherein the A
2
s in the number of “b” may be identical or different from one another), and Y represents a halogen atom, to an alcohol or an alcoholate represented by the following formula (3):
R
6
(OA
3
)
d
OM (3)
wherein R
6
represents C1-C36 linear or branched alkyl or C2-C36 alkenyl, A
3
represents C2-C3 linear or branched alkylene, “d” denotes the average addition mol number of alkylene oxide representing a number from 0 to 20 inclusive, wherein the A
3
s in the number of “d” are identical or different from one another, and M represents a hydrogen atom, alkali metal, or alkaline earth metal, to cause a reaction, thereby obtaining an asymmetric phosphoric triester represented by the following formula (4):
wherein R
4
, R
6
, A
1
, A
3
, “a”, and “d” respectively have the meanings as defined above, R
4
and R
6
are different from each other, and Z represents R
5
(OA
2
)
b
O— or R
6
(OA
3
)
d
O— (wherein R
5
, R
6
, A
2
, A
3
, “b”, and “d” respectively have the meanings as defined above. This method is hereinafter referred to as method (i).
In a further aspect of the present invention, there is provided a method for preparing an asymmetric phosphoric triester comprising the following steps: reacting a phosphorus oxyhalide represented by the following formula (5)
wherein Y has the same meaning as defined above, with a first organic hydroxyl compound represented by the following formula (6):
R
4
(OA
1
)
a
OH (6)
wherein R
4
, A
1
, and “a” have the same meanings as defined above, or with a mixture of the first organic hydroxyl compound and a second organic hydroxyl compound represented by the following formula (7):
R
5
(OA
2
)
b
OH (7)
wherein R
5
, A
2
, and “b” have the same meanings as defined above, in the presence of an organic amine,
removing a hydrochloric acid salt of the organic amine to obtain an alkyl phosphoric halide represented by the above-described formula (2), and
reacting the alkyl phosphoric halide represented by formula (2) with an alcohol or an alcoholate represented by the above-described formula (3) to obtain an asymmetric phosphoric triester represented by the above-described formula (4). This method is hereinafter referred to as method (ii).
In a still further aspect of the present invention, there is provided a method for preparing an asymmetric phosphoric triester comprising the following steps:
reacting a phosphorus oxyhalide of formula (5) with a first organic hydroxyl compound of formula (6) or with a mixture of the first organic hydroxyl compound and a second organic hydroxyl compound of formula (7),
removing a hydrochloric acid salt of the organic amine to obtain an alkyl phosphoric halide of formula (2), and
adding the alkyl phosphoric halide of formula (2) to an alcohol or an alcoholate of formula (3) to cause a reaction, thereby obtaining an asymmetric phosphoric triester of formula (4). This method is hereafter referred to as method (iii).
The above and other
Ishikawa Shinji
Kita Katsumi
Komori Takashi
Mizooku Takashi
Yano Shinji
Kao Corporation
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Venkat Jyothsna
LandOfFree
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