VISUALLY ENHANCED PARTICULATE
Perlite microspheres having a modified visual appearance, methods of making the perlite microspheres, a composition, such as a personal care, cosmetic or cleaning composition, comprising the perlite microspheres, a visually enhanced exfoliating agent comprising the perlite microspheres, and to the use of the perlite microspheres in personal care, cosmetic or cleaning compositions.
1 . A perlite microsphere having a modified visual appearance and at least one of the following:
(a) a −Δb* value or −Δb value compared to the unmodified perlite microsphere; or
(b) a +Δb* value or +Δb value compared to the unmodified perlite microsphere; or
(c) a −Δa* value or −Δa value compared to the unmodified perlite microsphere; or
(d) a +Δa* value or +Δa value compared to the unmodified perlite microsphere;
(e) a b* value or b value which is further from 0 than the unmodified perlite microsphere; or
(f) an a* value or a value which is further from 0 than the unmodified perlite microsphere; or
(g) a colour density which is greater than the colour density of the unmodified perlite microsphere.
2 . A perlite microsphere according to claim 1 , wherein the perlite microsphere is coloured with a colourant.
3 . A perlite microsphere according to claim 2 , wherein the colourant is present as a coating layer about the surface of the microsphere.
4 . A perlite microsphere according to claim 2 , wherein the colourant comprises a transition metal, Co, Ag, Pb, Fe, Cr, Ca, Na Cu, or a combination thereof.
5 . A perlite microsphere according to claim 1 , wherein the perlite microsphere has:
(i) a d 50 of from about 0.1 μm to about 400 μm; and/or
(ii) a d 90 of no greater than 900 μm; and/or
(iii) a d 10 of at least 30 μm and a d 90 of no greater than 900 μm; and/or
(iv) a density of from about 0.10 to about 4.0 g/cc; and/or
(v) a bulk density of from about 150-500 g/l; and/or
(vi) a crush strength of greater than 1000 kPa.
6 . (canceled)
7 . A perlite microsphere according to claim 1 wherein:
the a* value or a value is positive and further from 0 compared to the unmodified perlite microsphere and
(i) the b* value or b value is less than the a value or (ii) the b* value or b value is positive and within 1 of the a* value or a value.
8 . A perlite microsphere according to claim 1 , wherein:
the b* value or b value is −10 or less, and
(i) the a* value or a value is less than 0 or (ii) the a* value or a value is always positive and no greater than about 4.
9 . A perlite microsphere according to claim 1 , wherein the a* value or a value is less than 0.
10 . A perlite microsphere according to claim 1 , having a −ΔL* value or −ΔL value compared to the unmodified perlite microsphere, wherein the L* value or L value is less than the L* value or L value of the unmodified perlite microsphere.
11 . A method of making a perlite microsphere, comprising treating a perlite microsphere such that its visual appearance is modified compared to the unmodified perlite microsphere prior to treatment, wherein treating comprises:
(i) burnishing the perlite microsphere in the presence of a colourant, optionally wherein the perlite microsphere is coated with an undercoat prior to burnishing; or
(ii) mixing the perlite microsphere and colourant or colourant precursor in solution; or
(iii) vibrating a mixture of the perlite microsphere and colourant; or
(iv) spraying colourant or colourant precursor onto the surface of the perlite microsphere; or
(v) precipitating colourant onto the surface of the perlite microsphere; or
(vi) coating colourant on the perlite microsphere via a sol-gel process; or
(vii) forming an undercoat on the surface of the perlite microsphere followed by any one of (i)-(vi).
12 . A composition comprising perlite microspheres according to claim 1 .
13 . A composition according to claim 12 , wherein the composition is a personal care composition, a cosmetic composition, or a cleaning composition.
14 . A composition according to claim 12 , wherein the composition is an exfoliating cleansing composition or another personal care cleansing composition.
15 . A composition according to claim 14 , wherein the composition is a shower gel, bath gel, or hair shampoo.
16 . A composition comprising perlite microspheres, wherein the perlite microspheres comprise from about 0.1 wt. % to about 5.0 wt. % of a colourant agent.
17 . The composition according to claim 16 , wherein the composition comprises a cosmetically acceptable base and the perlite microspheres are suspended in the base.
18 . The composition according to claim 17 , wherein the base is formulated as a gel or a cream.
19 . The composition according to claim 16 , wherein the colourant agent comprises a transition metal.
20 . The composition according to claim 16 , wherein the colourant agent comprises a copper phthalocyanine pigment.
21 . The composition according to claim 16 , wherein the colourant comprises a natural dye.
22 - 32 . (canceled)