Silicone hydrogel reactive mixtures comprising borates
Disclosed in this specification is a method for forming a silicone hydrogel material that is useful for forming contact lens materials. The method includes using an effective amount of a borate additive to reduce the gel time of the silicone hydrogel reactive mixture and/or enhance the optical properties of the resulting cured material.
1. A contact lens formed from a silicone hydrogel material produced by a method comprising the steps of:
providing a mixture of polymerizable components that includes at least one hydrophilic component and at least one silicone component wherein at least one of the polymerizable components comprises at least one hydroxyl group, the mixture further including a sufficient amount of at least one borate to reduce cure time compared to an identical mixture that lacks the borate, the borate being selected from either boric anhydride or a borate represented by formula:
wherein R 1 , R 2 and R 3 are independently selected from the group consisting of hydrogen; C1-C16 alkyl groups; C1-C16 alkyl groups substituted with O, Cl, N, or Br; polymerizable groups; ester groups, amide groups, ether groups, silicone components and hydrophilic components, with the proviso that R 1 , R 2 , and R 3 comprise at most one hydroxyl group;
curing the mixture to form a cured silicone hydrogel material.
2. A material useful in forming a medical device comprising a silicone hydrogel material made by a method comprising the steps of:
providing a mixture of polymerizable components that includes at least one hydrophilic component and at least one silicone component wherein at least one of the polymerizable components comprises at least one hydroxyl group, the mixture further including a sufficient amount of at least one borate to reduce cure time compared to an identical mixture that lacks the borate, the borate being selected from either boric anhydride or a borate represented by formula:
wherein R 1 , R 2 and R 3 are independently selected from the group consisting of hydrogen; C1-C16 alkyl groups; C1-C16 alkyl groups substituted with O, Cl, N, or Br; polymerizable groups; ester groups, amide groups, ether groups, silicone components and hydrophilic components, with the proviso that R 1 , R 2 , and R 3 comprise at most one hydroxyl group;
curing the mixture to form a cured silicone hydrogel material.
3. A contact lens material formed from a silicone hydrogel material produced by a method comprising the steps of:
providing a mixture of polymerizable components that includes at least one hydrophilic component and at least one silicone component, wherein at least one of the polymerizable components contains a hydroxyl group, the mixture further including a sufficient amount of a borate to reduce cure time compared to an identical mixture that lacks the borate, the borate being selected from either boric anhydride or a borate represented by formula:
where wherein R 1 , R 2 and R 3 are independently selected from the group consisting of hydrogen; C1-C16 alkyl groups; C1-C16 alkyl groups substituted with O, Cl, N, or Br; polymerizable groups; ester groups, amide groups, ether groups, silicone components and hydrophilic components, with the proviso that R 1 , R 2 , and R 3 comprise at most one hydroxyl group;
curing the mixture to form a cured material.
4. A cured contact lens comprising a cured, optically clear polymeric material that is made from a mixture that includes
a hydrogel component mixture of at least one polymerizable hydrophilic component and at least one polymerizable silicone component, wherein at least one of the polymerizable components contains a hydroxyl group;
a borate represented by formula:
where wherein R 1 , R 2 and R 3 are independently selected from the group consisting of hydrogen; C1-C16 alkyl groups; C1-C16 alkyl groups substituted with O, Cl, N, or Br, with the proviso that R 1 , R 2 , and R 3 comprise at most one hydroxyl group.
5. The contact lens as recited in claim 4 , wherein the borate is selected from the group consisting of trimethyl borate and triethyl borate.
6. The contact lens as recited in claim 4 , wherein at least two of R 1 , R 2 and R 3 are divalent and taken together and form a cyclic borate ester.
7. The contact lens as recited in claim 4 , wherein at least one of R 1 , R 2 and R 3 is a polymerizable hydrocarbon.
8. The contact lens as recited in claim 4 , wherein R 1 , R 2 and R 3 are the same.
9. The contact lens as recited in claim 4 , wherein R 1 , R 2 and R 3 are monovalent.
10. The contact lens as recited in claim 4 , wherein R 1 , R 2 and R 3 are selected from the group consisting of methyl and ethyl.
11. The contact lens as recited in claim 4 , wherein R 1 , R 2 and R 3 are selected from the group consisting of n-propyl, iso-propyl, butyl and tert-butyl.
12. The contact lens as recited in claim 4 , wherein the borate is boric acid.
13. The contact lens as recited in claim 1 , wherein the borate is selected from the group consisting of borate esters of the formula:
where R 1 , R 2 and R 3 are hydrocarbons.
14. The contact lens as recited in claim 1 , wherein the cure time is time to 95% cure.