Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
2000-04-05
2002-11-05
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S163000, C525S222000, C525S299000, C526S318440, C424S070100
Reexamination Certificate
active
06476124
ABSTRACT:
The present invention relates to a composition, in particular a cosmetic composition, comprising, in a physiologically acceptable medium, at least one polymer with a highly specific ordered structure. These compositions find a specific application in the field of caring for or making up keratinous fibres, in particular as a mascara composition for the eyelashes or for the hair.
It is common practice to produce mascara compositions comprising at least one wax. However, the wax is never used alone because make-up with such compositions proves to be very mediocre, leading to the formation, on the eyelashes, of a non-homogeneous film which is reflected by the formation of thin films which crack immediately after drying.
It is also known, for example according to Applications WO 96/36323 and WO 96/33690, to combine a wax and a film-forming polymer in a mascara composition. However, such a combination does not make it possible to give good curling to the eyelashes or to obtain a thick make-up on the eyelashes.
Mascara compositions comprising microdispersions of waxes in combination with film-forming polymers have also been provided, for example in Applications EP-A-557,196 and EP-A-639,371. However, such compositions do not make it possible to obtain a thick make-up on the eyelashes, these mascaras not having a high load.
The Inventor has found that, surprisingly and unexpectedly, the use of highly specific polymers exhibiting a specific ordered structure can make it possible to obtain a composition capable of being applied to keratinous fibres, in particular the eyelashes, which can make possible improved curling of the eyelashes, the curling furthermore being instantaneous and long-lasting.
Thus, a subject-matter of the present invention is a polymer with a “star” structure represented by the following formula (I):
A—[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
]
n
in which:
A represents a polyfunctional centre, with a functionality of “n”, n being an integer greater than or equal to 2,
[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
] represents a polymer chain, also known as a “branch”, composed of identical or different polymerized monomers Mi having a polymerization index pj, each branch being identical or different and being grafted covalently to the centre A;
i being greater than or equal to 1 and pj being greater than or equal to 2;
the polymer comprising one or more monomers Mi chosen from polymerized monomeric units Mk, which may be identical or different, wherein a homopolymer formed by the corresponding polymerized monomers Mk has a Tg of greater than or equal to approximately 10° C., preferably of greater than or equal to 15° C. and even better still of greater than or equal to 20° C.
In a preferred embodiment, this or these monomers Mi being present, in the final polymer, in a minimum amount of approximately 45% by weight, preferably in an amount of between 55 and 99% by weight and even better still in an amount of 75-95% by weight with respect to the total weight of monomers.
Another subject-matter of the present invention is a polymer as described above further comprising one or more monomers Mj, the corresponding homopolymer of which exhibits a Tg of less than or equal to approximately 10° C., preferably of less than or equal to 5° C. and even better still of less than or equal to 0° C.
In a preferred embodiment, this or these monomers Mj are present in the final polymer in a maximum amount of approximately 55% by weight, preferably in an amount of between 1 and 45% by weight and even better still in an amount of 5-25% by weight with respect to the total weight of monomers.
Another subject-matter of the invention is a composition comprising, in a physiologically acceptable medium, at least one polymer as defined above.
Another subject-matter of the invention is a process for the cosmetic treatment of keratinous fibres, in particular the eyelashes and/or hair, characterized in that it comprises applying, to the latter, a cosmetic composition as defined above.
Another subject-matter of the invention is the use of at least one polymer as defined above in a cosmetic composition to be applied to the eyelashes, for allowing improved curling of the eyelashes to be obtained.
The compositions according to the invention exhibit a light texture and are very comfortable to wear throughout the day. They adhere well to the substrate to which they are applied.
They exhibit good resistance to water and can be easily removed, for example using a conventional make-up remover, in particular one with an oily base.
The composition according to the invention therefore comprises a polymer, the “star” structure of which can be illustrated, in a general way, by the following formula (I):
A—[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
]
n
in which:
A represents a polyfunctional centre, with a functionality of “n”, n being an integer greater than or equal to 2, preferably of between 4 and 10,
[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
] represents a polymeric chain, also known as a “branch”, composed of identical or different polymerized monomers Mi having a polymerization index pj, each branch being identical or different and being grafted covalently to the centre A;
i being greater than or equal to 1, preferably of between 2 and 10;
pj being greater than or equal to 2, preferably of between 10 and 20,000.
The polymer chains are preferably provided in the form of blocks with a molecular mass of greater than or equal to 500 which can range up to 2,000,000.
In a preferred embodiment, the polymer used in the context of the present invention can be obtained by controlled radical polymerization, also known as “living” radical polymerization. This technique makes it possible in particular to overcome the limitations inherent in conventional radical polymerization, that is to say that it makes it possible in particular to control the length of the chains of the polymer which is formed and therefore to obtain block structures.
The controlled radical polymerization makes it possible to reduce the reactions in which the growing radical species is deactivated, in particular the termination stage, which reactions, in conventional radical polymerization, interrupt the growth of the polymer chain in an irreversible and uncontrolled way.
In order to decrease the probability of termination reactions, provision has been made to block, in a temporary and reversible way, the growing radical species by forming so-called “dormant” active species with the aid of a bond of low dissociation energy.
In particular, mention may be made of the possibility of using bonds of C—ONR type (by reaction with a nitroxyl); this is illustrated in particular by the article “Synthesis of nitroxy-functionalized polybutadiene by anionic polymerization using a nitroxy-functionalized terminator”, published in Macromolecules, 1997, volume 30, pp. 4238-4242.
Mention may also be made of the possibility of using bonds of C-halide type (in the presence of metal/ligand complex). This is then described as atom transfer radical polymerization, also known under the abbreviation ATRP. This type of polymerization is reflected in control of the mass of the polymers which are formed and in a low polydispersity index by weight of the chains.
Atom transfer radical polymerization is generally carried out by polymerization:
of one or more radically polymerizable monomers, in the presence
of an initiator having at least one radically transferable atom or group,
of a compound comprising a transition metal capable of participating in a reduction stage with the initiator and a “dormant” polymer chain, and
of a ligand, which can be chosen from compounds comprising a nitrogen (N), oxygen (O), phosphorus (P) or sulphur (S) atom, which compounds are capable of coordinating via a &sgr; bond to the compound comprising a transition metal, or from compounds comprising a carbon atom, which compounds are capable of coordinating via a &pgr; or &sgr; bond to the compound comprising a transition metal, the formation of direct bonds between the compound comprising a transition
Asinovsky Olga
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
L'Oreal
Seidleck James J.
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