Polymeric interpenetrated network carrier and serial polymerization involving a crosslinked polymer network
View Patent ↗This invention relates to a highly stable, dense interpenetrated crosslinked polymer network (ICPN) containing (a) a crosslinked, network-forming primary polymer containing vinyl lactam and/or acrylic acid moieties, and (b) a secondary, optionally crosslinked, distinctly different polymer interpenetrated into the network of (a) and derived from a monomer selected from the group consisting of an acrylate and/or acrylamide monomer. The invention also relates to the oil-suspension, sequential polymerization of (a) and (b) for producing the above described interpenetrated polymeric network.
1. A stable, water resistant, anhydrous interpolymeric carrier concentrate which is an interpenetrated crosslinked polymer network for an active component comprising (a) a non-volatile oil suspension medium, (b) an oil soluble secondary polymer derived from a C 1 to C 30 alkyl acrylate monomer or a mixture of said acrylates formed and physically entrapped in a primary network of (c) a water insoluble, crosslinked polymer derived from vinyl pyrrolidone and acrylic acid monomers, or including an alkyl acrylate and alkyl acrylamide.
2. The carrier concentrate of claim 1 wherein the weight ratio of (b) to (c) is between about 10:1 and 1:10.
3. The carrier concentrate of claim 2 wherein the weight ratio of (b) to (c) is between about 2:1 and 1:2.
4. The carrier concentrate of claim 1 wherein (a) said oil is an organic suspension agent.
5. The carrier concentrate of claim 4 wherein said oil is isocetyl stearate.
6. The carrier concentrate of claim 1 wherein (c) is crosslinked between about 0.5–5 wt. %.
7. The carrier concentrate of claim 1 wherein (c) is crosslinked with pentaerithritol triallyl ether.
8. The carrier concentrate of claim 1 which contains a surfactant and/or a dispersant in an effective distributing amount for the active component.
9. The carrier concentrate of claim 1 wherein an active cosmetic or pharmaceutical component is added to the carrier concentrate in an amount up to about 20 wt. % and said concentrate optionally contains less than 10 wt. % of an inert excipient selected from the group consisting of a thickener, a moisturizer, a dispersing agent or a mixture thereof.
10. The carrier concentrate of claim 9 wherein said active component is a sun blocking agent.
11. The carrier concentrate of claim 1 wherein the weight ratio of monomer in polymer (c) to the monomer in polymer (b) is between about 1:10 and about 10:1.
12. The carrier concentrate of claim 1 wherein the weight ratio of monomer in polymer (c) to the monomer in polymer (b) is between about 1:2 and about 2:1.