Composition for strip-free hair removal

Abstract

The invention relates to an adhesive composition having a main fraction of synthetic tackifying resin, and a fraction of at least one macromolecular component, characterised in that said at least one macromolecular component comprises a copolymer of at least two different monomers taken from the alpha olefins and ethylene, to give the composition for strip-free hair removal mechanical or adhesive properties.

Claims

1. An adhesive composition for strip-free hair removal comprising at least 50% by weight of a cyclopentadiene resin and between 5% and 15% by weight of an ethylene/octene copolymer for modulating the strength properties or the adhesive properties of the composition, and wherein the composition does not contain ethylene vinyl acetate copolymer.

2. The adhesive composition according to claim 1, wherein the cyclopentadiene resin is present at at least 60% by weight.

3. The adhesive composition according to claim 1, wherein the ethylene/octene copolymer is a copolymer obtained by coordination polymerization.

4. The adhesive composition according to claim 3, wherein the coordination polymerization is catalyzed by a metallocene.

5. The adhesive composition according to claim 1, wherein the ethylene/octene copolymer is characterized by a melt index of more than 100 g/10 min with 2.16 kg at 190° C., or more than 250 g/10 min with 2.16 kg at 190° C.

6. The adhesive composition according to claim 1, wherein the ethylene/octene copolymer is characterized by a melt index of less than 800 g/10 min with 2.16 kg at 190° C.

7. The adhesive composition according to claim 1, wherein the ethylene/octene copolymer is characterized by a density of between 0.86 and 0.91 g/cm.sup.3.

8. An adhesive composition for strip-free hair removal comprising at least 50% by weight of a cyclopentadiene resin and between 1% and 18% by weight of a combination of an ethylene/octene copolymer and an ethylene vinyl acetate copolymer, wherein the ethylene/octene copolymer is for modulating the mechanical strength properties or the adhesive properties of the composition.

9. The adhesive composition according to claim 8, wherein the composition comprises between 5% and 15% by weight of the combination of the ethylene/octene copolymer and the ethylene vinyl acetate copolymer.

10. The adhesive composition according to claim 9, wherein the composition comprises at least 60% by weight of the cyclopentadiene resin.

11. The adhesive composition according to claim 8, wherein the composition comprises at least 60% by weight of the cyclopentadiene resin.

12. A depilatory method comprising heating the adhesive composition of claim 1 between 50° C. and 75° C. to form a warm paste, applying a layer of the warm paste to skin in need of depilation, cooling the layer of the warm paste to form a solidified layer, and peeling the solidified layer off the skin in the opposite direction of the growth of the hair.

13. The depilatory method according to claim 12, wherein the cyclopentadiene resin is present in a concentration of at least 60% by weight.

14. A depilatory method comprising heating the adhesive composition of claim 8 between 50° C. and 75° C. to form a warm paste, applying a layer of the warm paste to skin in need of depilation, cooling the layer of the warm paste to form a solidified layer, and peeling the solidified layer off the skin in the opposite direction of the growth of the hair.

Description

DETAILED DESCRIPTION

(1) A reference formula 1 is compared with a formula 2 in which the elastomer components (28% EVA copolymers of vinyl acetate) present in the formula 1, are replaced by an ethylene octene copolymer, wherein the octene is an alpha-olefin. A polycyclopentadiene synthetic tackifying resin is used.

(2) TABLE-US-00001 Formula 1 is shown in the table below: Hydrogenated C5 resin Majority component (>50%) Synthetic waxes Of the order of 10 to 20% EVA (28% VA) (two different Total EVA: of the order of 10%, compounds) between 5 and 15% total 100%

(3) Fractions are given by weight of the components based on the weight of the entire composition. This is also the case in the other formulas of this document.

(4) TABLE-US-00002 Formula 2 is shown in the table below: Hydrogenated C5 resin As in formula 1 Synthetic waxes As in formula 1 Ethylene/octene copolymer As much EVA as in Formula 1 (Affinity GA 1950) Of the order of 10%, between 5 and 15% total 100%

(5) The Affinity GA 1950 ethylene/octene copolymer component is available from Dow Chemical. It is characterized by a melt index of 500 g/10 min (2.16 kg @ 190° C.) and a density of 0.874. It has a tensile strength of 1.76 MPa.

(6) Other ethylene/octene copolymer grades may be used, for example with melt indices of more than 100 g/10 min (2.16 kg @ 190° C.), or more than 250 g/10 min (2.16 kg @ 190° C.)

(7) The copolymer may also have a density of between 0.86 and 0.91 g/cm.sup.3, 0.868 and 0.897 g/cm.sup.3, or between 0.870 and 0.880 g/cm.sup.3.

(8) As an illustration, the two waxes used have the following characteristics: solidification point 58 to 80° C.

(9) The resin is a hydrogenated C5 resin with a softening point between 85 and 100° C. and a molecular weight of 450 to 590 g/mol.

(10) The EVA used for reference have melt indices of 100 and 500 g/10 min (2.16 kg @ 190° C.) respectively, and densities both of 950 kg/m.sup.3. As already mentioned, this is EVA with 28% vinyl acetate.

(11) These compositions were applied by hair removal specialists on persons to be depilated in the context of blind tests. The composition, initially in granules, is heated in a wax heater to form a warm paste. The heating is between 50° C. and 75° C., and preferably 58° C. to 68° C. Then the warm paste is applied, for example, with a wooden spatula to form a thin elongated layer of the composition that upon cooling, traps the hair or sticks them together and hardens.

(12) This layer, once solidified by its spontaneous cooling is gripped at one of its ends and removed quickly in the opposite direction to the growth of the hair, through a qualified peeling operation. Peeling is thus performed between 20° C. and 38° C., often between 25° C. and 35° C.

(13) Formula 2 has tearing properties and mechanical properties (no breakage), as well as olfactory properties of the product which are improved over formula 1.

(14) The alpha-olefin used above is an alpha-olefin that is not a propylene. It has at least 4 or at least 5 carbons. It is an octene. The alpha-olefin used may also be, but is not limited to, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1 hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene or 1-eicosene, wherein each molecule is taken alone or possibly in combination, and is subject, of course, to the compatibility of the molecules aimed at cosmetic applications.

(15) Of particular interest, although not a limitation of the invention, are copolymers of the plastomer type, having a more dissipative behavior than the EVA used hitherto.

(16) The same tests were carried out with hydrogenated C9 resin compositions (aromatic tackifying resins).

(17) The resin used is a hydrogenated C9 resin having a softening point between 85 and 100° C. and a molecular weight of 600 to 800 g/mol.

(18) TABLE-US-00003 Formula 3 is shown in the table below. It is a formula with an ethylene vinyl acetate copolymer (EVA). Hydrogenated C9 resin Majority component (>50%) Synthetic waxes Of the order of 10 to 20% Beeswax Between 5 and 10% Paraffin oil Between 1 and 3% EVA (28% VA) (two different Of the order of 10%, between compounds) 5 and 15% Perfume Low proportion (less than 2%) total 100%

(19) TABLE-US-00004 Formula 4 is shown in the table below. This is a formula with ethylene/octene copolymers Hydrogenated C9 resin As in formula 3 Synthetic waxes As in formula 3 Beeswax As in formula 3 Paraffin oil As in formula 3 Ethylene octene copolymer As EVA in formula 3 (Affinity GA 1950) Perfume As in formula 3 total 100%

(20) The copolymers of ethylene octene lead to a composition which has properties at least as good as those of the composition comprising EVA. It is likely that improvement is possible if the formulas are modified while remaining within the scope of the invention in order to obtain an optimal result using ethylene octene copolymers.

(21) Experiments were further conducted with the Affinity GA 1950 ethylene/octene copolymers mixed in the same composition with the EVAs according to the following formulas:

(22) TABLE-US-00005 Formula 5: Hydrogenated C9 resin Majority component (>50%) Synthetic waxes Of the order of 10 to 20% Beeswax Between 5 and 10% Paraffin oil Between 1 and 3% Ethylene/octene copolymer Of the order of 6%, between (Affinity GA 1950) 2 and 12% EVA (28% VA) Of the order of 4%, between 2 and 10% Pigments Low proportion (less than 2%) Total 100%

(23) TABLE-US-00006 Formula 6: Hydrogenated C5 resin Majority component (>50%) Synthetic waxes Of the order of 10 to 20% Ethylene/octene copolymer Of the order of 5%, between (Affinity GA 1950) 2 and 12% EVA (28% VA) Of the order of 5%, between 2 and 12% total 100%

(24) The results showed an improvement of the tearing properties and the mechanical properties (absence of breakage), as well as a decrease in residues and odor, compared to the similar composition using only EVA.

(25) In conclusion, the ethylene/octene copolymers improve the performance of the compositions, in particular based on synthetic resins, in particular hydrogenated resins, and offer a new range of products with modified properties. These interesting results are not explained in line with the prior art and were unexpected.

(26) EVA (at 28% VA) and copolymers of ethylene octene may also act in synergy and provide the product with tearing properties and interesting mechanical properties compared to the products of the prior art.

(27) The ethylene octene copolymers used above constitute a particular case of macromolecular components of the class of copolymers of two or more monomers taken from the group comprising ethylene and alpha olefins. For the application described, preference is given to low crystallinity or even amorphous components. They are advantageously obtained by coordinative polymerization with a Zigler Natta catalyst, for example a metallocene catalyst. The invention extends to the use of copolymers of two or even three or more units taken from alpha-olefins and ethylene, wherein all the monomers may be different from ethylene, and at least one monomer may have, for example, at least 4 or at least 5 carbons.