Polycarbonate resin compositions with consistent color and stable blue-cut performance
Embodiments of the disclosure relate to a series of PC resin additives for maintaining the color stability and blue-cut performance during injection molding. The additives may be used to adapt a PC resin customarily used for sun protection lenses for clear lens applications.
1. A high blue-cut performance polycarbonate resin composition for use in clear lenses comprising:
a polycarbonate polymer base resin;
0.05 to 1% by weight of a UV absorber, based on the weight of the base resin;
0.05 to 1% by weight of an antioxidant, based on the weight of the base resin;
at least one selective blue blocking filter that at least partially blocks blue light in a wavelength range chosen within the 400-460 nm range;
a colorant additive; and
0.05 to 1% by weight of a hindered amine light stabilizer, based on the weight of the base resin;
wherein:
the resin composition blocks>99% of light with a wavelength less than 400 nm at each wavelength in the wavelength range of 315-400 nm; and
the color stability and blue-cut performance of the resin composition are maintained during an injection molding process.
2. The polycarbonate resin composition of claim 1 , wherein a weight average molecular weight of the polycarbonate polymer base resin ranges from about 20,000 to about 40,000 g/mol.
3. The polycarbonate resin composition of claim 1 , wherein the UV absorber is a benzotriazole absorber.
4. The polycarbonate resin composition of claim 3 , wherein the UV absorber is 2-(5-chloro-2H-benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-methyl phenol.
5. The polycarbonate resin composition of claim 1 , wherein the colorant additive is a blue dye, a violet dye, a red dye, or any combination thereof.
6. The polycarbonate resin composition of claim 1 , wherein the colorant additive is 1,4-di(2,6-dibromo-4-methylphenylamino) anthracene-9,10-dione.
7. The polycarbonate resin composition of claim 1 , wherein the antioxidant is a benzenepropanoic acid ester.
8. The polycarbonate resin composition of claim 7 , wherein the antioxidant is benzenepropanoic acid, 3(1,1-dimethylethyl)-4-hydroxy-5-methyl-1,1′-[1,2-ethanediylbis(oxy-2,1-ethanediyl)] ester.
9. The polycarbonate resin composition of claim 1 , wherein the hindered amine light stabilizer is bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate.
10. A clear lens comprising a high blue-cut performance polycarbonate resin composition, comprising:
a polycarbonate polymer base resin;
0.05 to 1% by weight of a UV absorber, based on the weight of the base resin;
0.05 to 1% by weight of an antioxidant, based on the weight of the base resin;
at least one selective blue blocking filter that at least partially blocks blue light in a wavelength range chosen within the 400-460 nm range;
a colorant additive; and
0.05 to 1% by weight of a hindered amine light stabilizer, based on the weight of the base resin;
wherein:
the resin composition blocks>99% of light with a wavelength less than 400 nm at each wavelength in the wavelength range of 315-400 nm;
the color stability and blue-cut performance of the resin composition are maintained during an injection molding process; and
a D65 transmittance of a 1.1 mm thick clear lens is greater than 85%.
11. The clear lens of claim 10 , wherein the clear lens comprises a BVC(B′) value of ≥20%.
12. The clear lens of claim 11 , wherein the clear lens further comprises a wafer overmold for increasing at least one of blue-cut performance, color balance, and lens clarity.
13. A method for maintaining the color stability and blue-cut performance of a resin composition during an injection molding process, comprising:
obtaining a base resin comprising a polycarbonate polymer base resin and adding to said base resin 0.05 to 1% by weight of a UV absorber, based on the weight of the base resin, 0.05 to 1% by weight of an antioxidant, based on the weight of the base resin, at least one selective blue blocking filter that at least partially blocks blue light in a wavelength range chosen within the 400-460 nm range, a colorant additive and 0.05 to 1% by weight of a hindered amine light stabilizer, based on the weight of the base resin,
injection molding the resin composition to produce a high blue-cut performance polycarbonate clear lens,
wherein the lens blocks>99% of light with a wavelength less than 400 nm at each wavelength in the wavelength range of 315-400 nm.