초록 ▼

The present invention is directed to a composition comprising polystyrene with at least 0.1% (w/w) of an additive, the article of manufacture thereof, such as a mold for making contact lenses and the mold assembly containing said mold, and the use of such mold so to facilitate demolding from a two m

The present invention is directed to a composition comprising polystyrene with at least 0.1% (w/w) of an additive, the article of manufacture thereof, such as a mold for making contact lenses and the mold assembly containing said mold, and the use of such mold so to facilitate demolding from a two mold assembly in the process of making contact lenses.

대표청구항 ▼

A mold material constituting a mold half for use in the production of contact lenses, said mold material comprising a thermoplastic polymer and an internal additive which is impregnated into said thermoplastic material by compounding said internal additive and said thermoplastic polymer, said intern

A mold material constituting a mold half for use in the production of contact lenses, said mold material comprising a thermoplastic polymer and an internal additive which is impregnated into said thermoplastic material by compounding said internal additive and said thermoplastic polymer, said internal additive is present in amounts ranging from about 0.1% to about 20% by weight, said thermoplastic material being polystyrene or polypropylene and said additive being a polyethylene or polypropylene wax having a molecular weight ranging from about 5,000 to about 200,000, stearate salt, a glycerol ester having a molecular weight of about 200-2,000, an amide wax of the formula R1CONH2, wherein R1 is a hyrocarbyl group, and the amide wax has a molecular weight ranging from about 2,000 to about 100,000, Montan wax, oxidized wax, fatty acid having a molecular weight of about 200 to 2,000, a complex ester or a combination thereof.