Polymerization of diol bis(allyl carbonates) using a mixture of two different peroxy compounds

A method of preparing a molded optical article, the method comprising:

• (1) providing a polymerizable composition,
• wherein preparation of the polymerizable composition comprises mixing (a) a polymerizable component comprising a diol bis (allyl carbonate) and/or a pre-polymer thereof with (b) a polymerization initiator component, wherein (b) the a polymerization initiator component comprises:
• (i) a di(C6-C10 alkyl) peroxydicarbonate, and
• (ii) an organic peroxide having one peroxy, one peroxycarbonate, or one peroxybenzoate group and a 1,1-dimethylalkyl group bonded to a peroxy oxygen,
• wherein the organic peroxide having one peroxy, one peroxycarbonate, or one peroxybenzoate group and a 1,1-dimethylalkyl group bonded to the peroxy oxygen comprises a molecular weight ranging from 200 to 250 g/mole,
• wherein the polymerization initiator (b) is free of diisopropyl peroxydicarbonate,
• wherein the di(C6-C10 alkyl) peroxydicarbonate (i) comprises amount ranging from 4.87% to 7.90% by weight relative to the total solids of the polymerizable composition, and
• wherein the organic peroxide having one peroxy, one peroxycarbonate, or one peroxybenzoate group and a 1,1-dimethylalkyl group bonded to a peroxy oxygen (ii) comprises an amount within the range defined by the following formula:
• (
• 4
• .
• 4
• ⁢
• 0
• ⁢
• 6
• ⁢
• X
• 2
• -
• 0
• .
• 5
• ⁢
• 9
• ⁢
• 2
• ⁢
• X
• +
• 0
• .
• 0
• ⁢
• 2
• ⁢
• 1
• )
• ≤
• Y
• ≤
• (
• 0
• .
• 7
• ⁢
• 2
• ⁢
• 6
• ⁢
• X
• 2
• -
• 0
• .
• 1
• ⁢
• 2
• ⁢
• 1
• ⁢
• X
• +
• 0
• .
• 0
• ⁢
• 0
• ⁢
• 9
• )
• wherein X corresponds to the weight fraction of the di(C6-C10 alkyl) peroxydicarbonate (i) and Y corresponds to the weight fraction of the organic peroxide having one peroxy, one peroxycarbonate, or one peroxybenzoate group and a 1,1-dimethylalkyl group bonded to a peroxy oxygen (ii);
• (2) introducing the polymerizable composition into a mold cavity of a mold;
• (3) introducing the mold into a preheated temperature controlled environment set at a temperature between 35° C. to 55° C.;
• and
• (4) subjecting the polymerizable composition within the mold cavity to a cure cycle to at least partially cure the polymerizable composition to form an at least partially cured optical article within the mold cavity,
• wherein the cure cycle comprises the following steps, in order:
• (A) setting the temperature of the temperature controlled environment to a temperature selected between 45° C. to 55° C. and maintaining the temperature setting for 3 hours in a first cure cycle step,
• (B) increasing the temperature of the temperature controlled environment to 60±2° C. at a constant rate over a 7 hour period in a second cure cycle step,
• (C) increasing the temperature of the temperature controlled environment to 80±2° C. at a constant rate over a 5 hour period in a third cure cycle step,
• (D) increasing the temperature of the temperature controlled environment at a constant rate over a 1 hour period to reach a maximum temperature of 100° C. to 110° C. in a fourth cure cycle step, and
• (E) holding the polymerizable composition at the maximum temperature for at least 4 hours.