Nucleated polypropylene resin for primary lens package
A primary package for holding contact lenses is disclosed. It is primarily made from a nucleated polypropylene resin. It has been determined that the nucleated polypropylene resin should be formulated with a polypropylene base resin with greater than 99% polypropylene homopolymer and a primary and secondary stabilizer, which also contains a catalyst acid scavenger; at least one nucleator/clarifier; and at least one catalyst acid scavenger.
1. In combination:
a contact lens package comprising:
a nucleated polypropylene resin formed from a polypropylene base resin consisting of a polypropylene homopolymer, a primary stabilizer comprising tris(3,5-di-butyl-4-hydroxylbenzyl) isocyanurate, and a secondary stabilizer comprising tris-(2,4-di-t-butylphenyl) phosphite;
at least one nucleator comprising 1,2-cyclohexane dicarboxylic acid, calcium salt (1:1), (1R, 2S)-rel-; and
at least one catalyst acid scavenger;
wherein said nucleated polypropylene resin formed from a polypropylene base resin at greater than 99 weight %;
said at least one nucleator at less than 0.25 weight %; and
said at least one catalyst acid scavenger at less than 0.1 weight %, and
a contact lens contained in said package.
2. The combination of claim 1 wherein the homopolymer is 1-propene homopolymer.
3. The combination of claim 1 wherein the scavenger is a magnesium hydroxide carbonate hydrate.
4. The combination of claim 1 wherein said scavenger is present in an amount of about 0.04 weight %.
5. The combination of claim 1 wherein the nucleating agent is present in an amount of about 0.04 weight %.
6. The combination of claim 1 further containing a primary antioxidant is present in an amount of about 0.05 weight %.
7. The combination of claim 6 further containing a secondary antioxidant is present in an amount of about 0.10 weight %.
8. The combination of claim 1 wherein the homopolymer is present in an amount greater than 99 weight %.