POLYAMIDE 10.10 POWDER AND ITS USE IN PERSONAL CARE PRODUCTS
The present invention is directed to particles based on polyamide 10.10, wherein the particles have a mean particle size d 50 from 1 to 50 μm, an apparent density from 180 to 300 g/l and a NH 2 /COOH end group ratio of from 50:50 to 95:5, the use of such particles for the production of cosmetic compositions, the cosmetic composition itself and a process for producing the particles.
1 . Particles based on polyamide 10.10, wherein said particles have a mean particle size d 50 from 1 to 50 μm, an apparent density from 180 to 300 g/l and a NH 2 /COOH end group ratio from 50:50 to 95:5.
2 . The particles as claimed in claim 1 , wherein said polyamide 10.10 has a pH from 2 to 7.
3 . The particles as claimed in claim 1 , further comprising a buffer system or at least a remains of a buffer system.
4 . The particles as claimed in claim 3 , wherein the buffer system comprises an organic acid or a mineral acid and a corresponding salt thereof.
5 . The particles as claimed in claim 1 , wherein said particles have a BET surface from 1 to 20 m 2 /g.
6 . The particles as claimed in claim 1 , wherein said particles have a BET surface of more than 20 to 50 m 2 /g.
7 . The particles as claimed in claim 1 , wherein said polyamide 10.10 has a mean number average molecular weight from 5000 to 50000 g/mol.
8 . The particles as claimed in claim 1 , further comprising inorganic particles, wherein said inorganic particles are present in a content from 0.1 to 80% by weight, based on the total weight of the particles.
9 . A formulation comprising 0.1 to 20% by weight of the particles of claim 1 .
10 . The formulation according to claim 9 , further comprising a component of a powder composition, a foundation, a nail polish, an aerosol, a lipstick, an eye shadow, a masking stick, a rouge, a skin cream, a face cream, a hair care formulation, a sun care formulation, a cleansing formulation or antiperspirant/deodorizing formulation.
11 . A process for producing a formulation comprising incorporating 1 to 20% by weight of particles based on polyamide 10.10, wherein said particles have a mean particle size d 50 from 1 to 50 μm, an apparent density from 180 to 300 g/l and a NH 2 /COOH end group ratio from 50:50 to 95:5 to a composition.
12 . A process for preparing particles comprising:
dissolving polyamide 10.10 having a relative solution viscosity η rel in a range from 1.4 to 2.0, measured in 0.5% m-cresol solution at 25° C., in an alcoholic medium;
lowering, in a first stage, the temperature until nucleation takes place without precipitation;
lowering, in a second stage, the temperature until supersaturation results; and
precipitating said polyamide and drying the resulting suspension, wherein said polyamide 10.10 is dissolved at from 130 to 165° C. and precipitation is carried out isothermally at a precipitation temperature from 100 to 130° C. preceded by a nucleation stage at from 2 to 20° C. above said precipitation temperature, wherein said temperature during precipitation is held constant for from 10 minutes to 2 hours, and wherein said temperature during nucleation is held constant for from 30 to 90 minutes.
13 . The process according to claim 12 , wherein in the dissolving step 0.1 to 80% by weight, of inorganic particles are added to the alcoholic medium, based on the total weight of the sum of polyamide 10.10 and inorganic particles used.
14 . The process as claimed in claim 13 , wherein said inorganic particles are selected from the group of Al 2 O 3 , TiO 2 , ZrO 2 , SiO 2 , ZnO, Bi 2 O 3 , CeO 2 , ITO, ATO, IZO, boron nitride, boron carbide, mixed oxides and spinets, and wherein said inorganic particles have a mean particle size d 50 from 0.001 to 0.8 μm.
15 . The process according to claim 12 , wherein the inorganic particles are added to the medium by adding a suspension comprising alcohol and the inorganic particles, wherein the suspension has a content of inorganic particles in the range from 10 to 60% by weight based on the total weight of the suspension.