Reactive dyes for contact lenses
View Patent ↗A method for preparing a polymerizable monomer-dye compound is provided in which a monomer, a reactive dye, and base are combined under substantially anhydrous reaction conditions to form the polymerizable monomer-dye compound, wherein the monomer comprises a pendant reactive group that covalently links to the reactive dye to form the monomer-dye compound.
1. A method for preparing a polymerizable monomer-dye compound, comprising:
combining a monomer, a reactive dye, and base under substantially anhydrous reaction conditions to form a reaction product comprising the monomer-dye compound, wherein the monomer comprises a pendant reactive group that covalently links to the reactive dye during the reaction to form the polymerizable monomer-dye compound, wherein the pendant reactive group is a hydroxyl group, an amino group, or a sulthydryl group that forms an ether linkage, amino linkage, or thioether linkage, respectively, between the monomer and the dye.
2. The method of claim 1 , wherein the monomer is hydroxyethyl methacrylate.
3. The method of claim 1 , wherein the monomer is an Si—O-containing monomer.
4. The method of claim 1 , wherein the monomer and the reactive dye are in the reaction mixture at a molar ratio of from about 1:1 to about 6:1, respectively.
5. The method of claim 1 , wherein the monomer is present in a molar amount that is at least 5 times that of the reactive dye.
6. The method of claim 1 , wherein the reactive dye comprises a sulphatoethylsulphonyl group, a halotriazine group, or a vinyl group, that reacts with the pendant reactive group of the monomer to form the covalent linkage between the monomer and the dye.
7. The method of claim 1 , wherein the reactive dye is RB19, RB4 or RB69.
8. The method of claim 1 , wherein the reactive dye is RB19 at a purity of at least 90%.
9. The method of claim 1 , wherein the base is NaOH, or K2CO3, or NaH, or NaNH2, or any combination thereof.
10. The method of claim 1 , wherein the monomer is HEMA, the reactive dye is RB19, and the base is NaH.
11. The method of claim 10 , wherein the RB19 and NaH are mixed together and at least 90% of the RB19 is converted into an intermediate product before the HEMA is added to the reaction mixture.
12. The method of claim 1 , wherein the reaction mixture is mixed at a temperature of about 15-45° C.
13. The method of claim 1 , wherein the reaction mixture is mixed at a temperature of about 20-30° C.
14. The method of claim 1 , wherein the reaction lasts for about 1 to about 6 hours.