Gel-based lipstick having improved rheology

1. A method for imparting an unctuous film to the lips comprising applying thereto a composition comprising:

(a) from 0.1 to 40% by weight of a polymeric gellant, said polymeric gellant consisting of a single ester-terminated poly(ester-amide) capable of forming a gel with low-polarity and nonpolar oils at or below a sol-gel transition temperature T gel of said ester-terminated poly(ester-amide), either alone or in combination with a silicone T-resin, wherein T gel is above body temperature;

(b) from 0.1-20% by weight of a first wax component having a melting point above T gel ;

(c) from 0.1-20% by weight of a second wax component having a melting point at or below T gel ; and

(d) from 0.1-90% by weight of one or more low-polarity or nonpolar ester oils capable of forming a gel with said copolymer or copolymers at or below said sol-gel transition temperature T gel ;

wherein said composition is self-supporting at room temperature and is further characterized by a viscosity measured during a second shear cycle that is within ±20% of the viscosity measured during a first shear cycle at every shear rate between 1 and 10 sec −1 , wherein said first and said second shear cycles are identical and comprise increasing shear rates from 1 to 1,000 sec −1 .

2. The method of claim 1 , wherein the ester-terminated poly(ester-amide) is comprised of Bis-Stearyl Ethylenediamine/Neopentyl Glycol/Stearyl Hydrogenated Dimer Dilinoleate.

3. The method of claim 2 , wherein the first wax component comprises silicone waxes having a melting point between about 53 and 75 C.

4. The method of claim 2 , wherein the second wax component comprises cocoa butter.

5. The method of claim 2 , wherein the first wax component comprises silicone waxes having a melting point between about 53 and 75 C and the second wax component comprises cocoa butter.

6. The method of claim 2 wherein the viscosity measured in said second shear cycle is within ±10% of the viscosity measured during said first shear cycle at every shear rate between 1 and 10 sec −1 .

7. The method of claim 2 wherein the viscosity measured in said second shear cycle is within ±5% of the viscosity measured during said first shear cycle at every shear rate between 1 and 10 sec −1 .

8. The method of claim 2 further characterized by a viscosity measured during said second shear cycle that is within ±20% of the viscosity measured during said first shear cycle at every shear rate between 10 and 100 sec −1 .

9. The method of claim 2 further characterized by a viscosity greater than 50 Pa·sec at a shear rate of 1 sec −1 as measured during said first shear cycle.

10. The method of claim 2 further comprising a silicone T-resin.

11. The method of claim 10 wherein said silicone T-resin comprises siloxy moieties of the form:

[RSiO 3/2 ] a [R 1 SiO 3/2 ] b [R 2 SiO 3/2 ] c [R 3 3 SiO 1/2 ] d [R 3 2 SiO 2/2 ] e [SiO 4/2 ] f

where R is methyl; R 1 is C 2-20 alkyl or C 5-20 cycloalkyl; R 2 is phenyl, R 3 is C 1-20 alkyl, C 5-20 cycloalkyl, C 7-14 aralkyl, C 7-14 alkaryl, or C 6-10 aryl; and a, b, and c are such that their respective siloxy groups together comprise at least 90 mol percent of the total of siloxy moieties, and d, e, and f are such that their respective moieties together comprise less than 10 mol percent of all of siloxy moieties.

12. The method of claim 11 wherein said silicone T-resin is a polyphenylsilsesquioxane.

13. The method of claim 11 wherein said silicone T-resin has a refractive index of at least 1.5, measured as a film at 25° C.

14. The method of claim 11 wherein the average molecular weight of said silicone T-resin is between 5,000 and 6,000 Daltons.

15. A method for imparting an unctuous film to the lips comprising applying thereto a composition comprising:

(a) from 0.1 to 40% by weight of a polymeric gellant, said polymeric gellant consisting essentially of a single ester-terminated poly(ester-amide) capable of forming a gel with low-polarity and nonpolar oils at or below a sol-gel transition temperature T gel of 70° C. to 85° C., either alone or in combination with a silicone T-resin;

(b) from 0.1-20% by weight of a first wax component having a melting point above T gel ;

(c) from 0.1-20% by weight of a second wax component having a melting point at or below T gel ; and

(d) from 0.1-90% by weight of one or more low-polarity or nonpolar ester oils capable of forming a gel with said ester terminated poly(ester-amide) polymer at or below said sol-gel transition temperature T gel ;

wherein said composition is self-supporting at room temperature and is further characterized by a viscosity measured during a second shear cycle that is within ±20% of the viscosity measured during a first shear cycle at every shear rate between 1 and 10 sec −1 , wherein said first and said second shear cycles are identical and comprise increasing shear rates from 1 to 1,000 sec −1 ; and

wherein said composition is characterized by:

(i) a viscosity greater than 100 Pa·sec at shear rates between 1 and 5 sec −1 when measured during said first and second shear cycles; and

(ii) a viscosity greater than 10 Pa·sec at shear rates between 10 and 50 sec −1 when measured during said first and second shear cycles; and

(iii) a viscosity greater than 1 Pa·sec at a shear rate of 100 sec −1 when measured during said first and second shear cycles.

16. The method of claim 15 further comprising from about 0.1 to about 8% by weight of a silicone T-resin.

17. The method of claim 15 wherein said silicone T-resin is a polyphenylsilsesquioxane.

18. The method of claim 15 wherein the silicone T-resin is a polyphenylsilsesquioxane.

19. The method of claim 15 , wherein the first wax component comprises silicone waxes having a melting point between about 53 and 75 C.

20. The method of claim 15 , wherein the second wax component comprises cocoa butter.