POLYURETHANE-BASED PHOTOCHROMIC RESIN LENS AND PREPARATION METHOD THEREOF

Abstract

The present invention discloses a polyurethane-based photochromic resin lens and a preparation method thereof. The lens includes the following ingredients: 100 weight parts of polyurethane monomers, 0.01-0.1 weight part of an initiator, 0.1-10 weight parts of an additive and 0.01-0.2 weight part of color changing powder, wherein the additive is a molecular weight modifier. The photochromic resin lens of the present invention uses a polyurethane base to realize substrate color change, the impact-resistant strength is high, a photochromic effect is good, a visible light transmittance of the lens after hard coating can reach about 93%, and after the deepest color change depth is reached under ultraviolet irradiation, the visible light transmittance is only 15-25%.

Claims

1. A polyurethane-based photochromic resin lens, wherein the lens comprises the following ingredients: 100 weight parts of polyurethane monomers, 0.01-0.1 weight part of an initiator, 0.1-10 weight parts of an additive and 0.01-0.2 weight part of color changing powder, wherein the additive is a molecular weight modifier.

2. The polyurethane-based photochromic resin lens according to claim 1, wherein the lens comprises the following ingredients: 100 weight parts of polyurethane monomers, 0.02-0.06 weight part of an initiator, 1-5 weight parts of an additive and 0.03-0.1 weight part of color changing powder, wherein the additive is a molecular weight modifier.

3. The polyurethane-based photochromic resin lens according to claim 1, wherein the polyurethane monomers are a mixture of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, pentaerythritol tetra(3-mercaptopropionate) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol, and a mass ratio is 35-55:15-35:20-40.

4. The polyurethane-based photochromic resin lens according to claim 1, wherein the initiator is one or more of dimethyl carbonate, diethyl carbonate, N-dicyclohexylmethylamine, N,N-dimethylcyclohexylamine, dimethyltin dichloride and dibutyltin dichloride.

5. The polyurethane-based photochromic resin lens according to claim 1, wherein the molecular weight modifier is polyether polyol with a weight average molecular weight of 2000-10000.

6. The polyurethane-based photochromic resin lens according to claim 5, wherein the polyether polyol is one of polypropylene oxide glycol, polytetrahydrofuran glycol, polyvinyl alcohol or propylene oxide and ethylene oxide copolymers.

7. The polyurethane-based photochromic resin lens according to claim 1, wherein the color changing powder is one or a mixture of two of photochromic organic substances of spiropyranes and spirooxazines.

8. The polyurethane-based photochromic resin lens according to claim 1, wherein ingredients of the lens further comprise a mold release agent, a content of the mold release agent is 100:0.0001-0.005, and preferably 100:0.001-0.003.

9. A preparation method of the polyurethane-based photochromic resin lens according to claim 1, comprising the following steps: (1) dissolving the color changing powder and the initiator, proportionally mixing the polyurethane monomers, the molecular weight modifier, the dissolved initiator and color changing powder and the mold release agent, performing stirring for 30-60 min under the condition of 10° C., and then performing still standing in vacuum for 30-45 min; (2) filtering a material prepared in step (1), and then, injecting the material into a mold to be sealed; and (3) sequentially performing primary curing and secondary curing on the mold subjected to material pouring in step (2).

10. The preparation method of the polyurethane-based photochromic resin lens according to claim 9, wherein the polyurethane monomers in step (1) are a mixture of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, pentaerythritol tetra(3-mercaptopropionate) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol; and when being mixed, each ingredient is added according to the following sequence: taking partial 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane to respectively dissolve the color changing powder and the initiator, after the dissolution is completed, mixing the material with the rest 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane and the molecular weight modifier, lowering the temperature to 10° C., and then, adding pentaerythritol tetra(3-mercaptopropionate) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol.

Description

DETAILED DESCRIPTION

[0035] Hereinafter, exemplary implementations of the present invention will be described in more detail with reference to specific embodiments.

[0036] The followings are raw materials and auxiliaries used in the embodiments:

[0037] Polyurethane monomer: a mixture of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, pentaerythritol tetra(3-mercaptopropionate) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol: Mitsui Co., Ltd. in Japan

[0038] Dimethyl carbonate: Shenzhen Division Tech Co., Ltd.

[0039] N-dicyclohexylmethylamine: Shanghai Lianshuo Biological Technology Co., Ltd.

[0040] N,N-dimethylcyclohexylamine: Shanghai Lianshuo Biological Technology Co., Ltd.

[0041] Dimethyltin dichloride: Shanghai Aladdin Bio-Chem Technology Co., Ltd.

[0042] Color changing powder: Guangzhou Kehan Science and Technology Co., Ltd.

[0043] Polypropylene oxide glycol: Mitsubishi Corporation in Japan

[0044] Polytetrahydrofuran glycol: Mitsubishi Corporation in Japan

[0045] Propylene oxide and ethylene oxide copolymers: Shanghai YuanMu Biological Technology Co., Ltd.

[0046] Mold release agent: JP-506H, Mitsui Co., Ltd. in Japan.

EXAMPLE 1

[0047] A preparation method of a polyurethane-based photochromic resin lens with a refractive index being 1.60 included the following steps:

[0048] (1) 0.01 g of dimethyl carbonate was dissolved by 5.5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 30-60 min. At the same time, 0.03 g of color changing powder was dissolved by 4.5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 60 min to obtain color change liquid. 35 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 0.1 mg of a mold release agent, 0.1 g of polypropylene oxide glycol and the dissolved color change liquid were added in a proportioning kettle, and were stirred till complete dissolution. The dissolved dimethyl carbonate solution was added into a reaction kettle to be stirred for 10 min, cooling was performed to reach about 10° C., 30 g of pentaerythritol tetra(3-mercaptopropionate) and 25 g of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol were added, stirring was performed for 30-60 min in 10° C. water bath, and finally, still standing was performed in vacuum for 30-45 min.

[0049] (2) Material pouring: the material uniformly mixed in step (1) was filtered through a 1 μm filter, and then injected into a glass mold, and sealing was performed by using an adhesive tape.

[0050] (3) Primary curing: the mold subjected to material pouring in step (2) was put into a curing furnace to be subjected to primary curing forming according to the following curing time and temperature curves: performing heat insulation for 5 h at an initial temperature of 20° C., raising the temperature to 50-55° C. in 3 h, raising the temperature to 70-75° C. in 5 h, raising the temperature to 80-85° C. in 2 h, raising the temperature to 90-95° C. in 1 h, raising the temperature to 100-105° C. in 2 h, and lowering the temperature to 75-80° C. in 1 h, and a speed was constant in the temperature raising and lowering processes.

[0051] (4) Mold opening, edging and cleaning: mold opening was performed after curing forming, edge chamfering was performed by an edger, and then, surface cleaning was performed.

[0052] (5) Secondary curing: the cleaned lens was put into the curing furnace again to be subjected to secondary curing at a curing temperature of 105-110° C. for 2.5 h.

[0053] After the above preparation was completed, a hardening layer was plated on the surface of the lens by using a dip-coating method, and an antireflecting film layer consisting of silicon dioxide, zirconium dioxide, indium tin oxide and a waterproof layer was plated on the surface of the lens by using a vacuum film plating method.

EXAMPLE 2

[0054] A preparation method of a polyurethane-based photochromic resin lens with a refractive index being 1.60 included the following steps:

[0055] (1) 0.02 g of N-dicyclohexylmethylamine was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 30-60 min. At the same time, 0.06 g of color changing powder was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 60 min to obtain color change liquid. 40 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 1 mg of a mold release agent, 1 g of polytetrahydrofuran glycol and the dissolved color change liquid were added in a proportioning kettle, and were stirred till complete dissolution. The dissolved N-dicyclohexylmethylamine solution was added into a reaction kettle to be stirred for 10 min, cooling was performed to reach about 10° C., 20 g of pentaerythritol tetra(3-mercaptopropionate) and 30 g of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol were added, stirring was performed for 30-60 min in 10° C. water bath, and finally, still standing was performed in vacuum for 30-45 min.

[0056] (2) Material pouring: the material uniformly mixed in step (1) was filtered through a 1 μm filter, and then injected into a glass mold, and sealing was performed by using an adhesive tape.

[0057] (3) Primary curing: the mold subjected to material pouring in step (2) was put into a curing furnace to be subjected to primary curing forming according to the following curing time and temperature curves: performing heat insulation for 5 h at an initial temperature of 20° C., raising the temperature to 50-55° C. in 3 h, raising the temperature to 70-75° C. in 5 h, raising the temperature to 80-85° C. in 2 h, raising the temperature to 90-95° C. in 1 h, raising the temperature to 100-105° C. in 2 h, and lowering the temperature to 75-80° C. in 1 h, and a speed was constant in the temperature raising and lowering processes.

[0058] (4) Mold opening, edging and cleaning: mold opening was performed after curing forming, edge chamfering was performed by an edger, and then, surface cleaning was performed.

[0059] (5) Secondary curing: the cleaned lens was put into the curing furnace again to be subjected to secondary curing at a curing temperature of 105-110° C. for 2.5 h.

[0060] After the above preparation was completed, a hardening layer was plated on the surface of the lens by using a dip-coating method, and an antireflecting film layer consisting of silicon dioxide, zirconium dioxide, indium tin oxide and a waterproof layer was plated on the surface of the lens by using a vacuum film plating method.

EXAMPLE 3

[0061] A preparation method of a polyurethane-based photochromic resin lens with a refractive index being 1.60 included the following steps:

[0062] (1) 0.06 g of N,N-dimethylcyclohexylamine was dissolved by 6 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 30-60 min. At the same time, 0.08 g of color changing powder was dissolved by 4 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 60 min to obtain color change liquid. 30 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 3 mg of a mold release agent, 5 g of propylene oxide and ethylene oxide copolymers and the dissolved color change liquid were added in a proportioning kettle, and were stirred till complete dissolution. The dissolved N,N-dimethylcyclohexylamine solution was added into a reaction kettle to be stirred for 10 min, cooling was performed to reach about 10° C., 25 g of pentaerythritol tetra(3-mercaptopropionate) and 35 g of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol were added, stirring was performed for 30-60 min in 10° C. water bath, and finally, still standing was performed in vacuum for 30-45 min.

[0063] (2) Material pouring: the material uniformly mixed in step (1) was filtered through a 1 μm filter, and then injected into a glass mold, and sealing was performed by using an adhesive tape.

[0064] (3) Primary curing: the mold subjected to material pouring in step (2) was put into a curing furnace to be subjected to primary curing forming according to the following curing time and temperature curves: performing heat insulation for 5 h at an initial temperature of 20° C., raising the temperature to 50-55° C. in 3 h, raising the temperature to 70-75° C. in 5 h, raising the temperature to 80-85° C. in 2 h, raising the temperature to 90-95° C. in 1 h, raising the temperature to 100-105° C. in 2 h, and lowering the temperature to 75-80° C. in 1 h, and a speed was constant in the temperature raising and lowering processes.

[0065] (4) Mold opening, edging and cleaning: mold opening was performed after curing forming, edge chamfering was performed by an edger, and then, surface cleaning was performed.

[0066] (5) Secondary curing: the cleaned lens was put into the curing furnace again to be subjected to secondary curing at a curing temperature of 105-110° C. for 2.5 h.

[0067] After the above preparation was completed, a hardening layer was plated on the surface of the lens by using a dip-coating method, and an antireflecting film layer consisting of silicon dioxide, zirconium dioxide, indium tin oxide and a waterproof layer was plated on the surface of the lens by using a vacuum film plating method.

EXAMPLE 4

[0068] A preparation method of a polyurethane-based photochromic resin lens with a refractive index being 1.60 included the following steps:

[0069] (1) 0.08 g of dimethyltin dichloride was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 30-60 min. At the same time, 0.15 g of color changing powder was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 60 min to obtain color change liquid. 40 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 5 mg of a mold release agent, 8 g of polypropylene oxide glycol and the dissolved color change liquid were added in a proportioning kettle, and were stirred till complete dissolution. The dissolved dimethyl carbonate solution was added into a reaction kettle to be stirred for 10 min, cooling was performed to reach about 10° C., 30 g of pentaerythritol tetra(3-mercaptopropionate) and 20 g of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol were added, stirring was performed for 30-60 min in 10° C. water bath, and finally, still standing was performed in vacuum for 30-45 min.

[0070] (2) Material pouring: the material uniformly mixed in step (1) was filtered through a 1 μm filter, and then injected into a glass mold, and sealing was performed by using an adhesive tape.

[0071] (3) Primary curing: the mold subjected to material pouring in step (2) was put into a curing furnace to be subjected to primary curing forming according to the following curing time and temperature curves: performing heat insulation for 5 h at an initial temperature of 20° C., raising the temperature to 50-55° C. in 3 h, raising the temperature to 70-75° C. in 5 h, raising the temperature to 80-85° C. in 2 h, raising the temperature to 90-95° C. in 1 h, raising the temperature to 100-105° C. in 2 h, and lowering the temperature to 75-80° C. in 1 h, and a speed was constant in the temperature raising and lowering processes.

[0072] (4) Mold opening, edging and cleaning: mold opening was performed after curing forming, edge chamfering was performed by an edger, and then, surface cleaning was performed.

[0073] (5) Secondary curing: the cleaned lens was put into the curing furnace again to be subjected to secondary curing at a curing temperature of 105-110° C. for 2.5 h.

[0074] After the above preparation was completed, a hardening layer was plated on the surface of the lens by using a dip-coating method, and an antireflecting film layer consisting of silicon dioxide, zirconium dioxide, indium tin oxide and a waterproof layer was plated on the surface of the lens by using a vacuum film plating method.

Comparative Example 1

[0075] An existing acrylic photochromic resin lens with a refractive index being 1.60.

Comparative Example 2

[0076] A preparation method of a polyurethane-based photochromic resin lens with a refractive index being 1.60 included the following steps:

[0077] (1) 0.02 g of dibutyltin dichloride was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 30-60 min. At the same time, 0.06 g of color changing powder was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 60 min to obtain color change liquid. 40 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 1 mg of a mold release agent, 1 g of polytetrahydrofuran glycol and the dissolved color change liquid were added in a proportioning kettle, and were stirred till complete dissolution. The dissolved N-dicyclohexylmethylamine solution was added into a reaction kettle to be stirred for 10 min, cooling was performed to reach about 10° C., 20 g of pentaerythritol tetra(3-mercaptopropionate) and 30 g of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol were added, stirring was performed for 30-60 min in 10° C. water bath, and finally, still standing was performed in vacuum for 30-45 min.

[0078] (2) Material pouring: the material uniformly mixed in step (1) was filtered through a 1 μm filter, and then injected into a glass mold, and sealing was performed by using an adhesive tape.

[0079] (3) Primary curing: the mold subjected to material pouring in step (2) was put into a curing furnace to be subjected to primary curing forming according to the following curing time and temperature curves: performing heat insulation for 5 h at an initial temperature of 20° C., raising the temperature to 50-55° C. in 3 h, raising the temperature to 70-75° C. in 5 h, raising the temperature to 80-85° C. in 2 h, raising the temperature to 90-95° C. in 1 h, raising the temperature to 100-105° C. in 2 h, and lowering the temperature to 75-80° C. in 1 h, and a speed was constant in the temperature raising and lowering processes.

[0080] (4) Mold opening, edging and cleaning: mold opening was performed after curing forming, edge chamfering was performed by an edger, and then, surface cleaning was performed.

[0081] (5) Secondary curing: the cleaned lens was put into the curing furnace again to be subjected to secondary curing at a curing temperature of 105-110° C. for 2.5 h.

[0082] After the above preparation was completed, a hardening layer was plated on the surface of the lens by using a dip-coating method, and an antireflecting film layer consisting of silicon dioxide, zirconium dioxide, indium tin oxide and a waterproof layer was plated on the surface of the lens by using a vacuum film plating method.

Comparative Example 3

[0083] A preparation method of a polyurethane-based photochromic resin lens with a refractive index being 1.60 included the following steps:

[0084] (1) 0.02 g of N-dicyclohexylmethylamine was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 30-60 min. At the same time, 0.06 g of color changing powder was dissolved by 5 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 60 min to obtain color change liquid. 40 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 1 mg of a mold release agent and the dissolved color change liquid were added in a proportioning kettle, and were stirred till complete dissolution. The dissolved N-dicyclohexylmethylamine solution was added into a reaction kettle to be stirred for 10 min, cooling was performed to reach about 10° C., 20 g of pentaerythritol tetra(3-mercaptopropionate) and 30 g of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol were added, stirring was performed for 30-60 min in 10° C. water bath, and finally, still standing was performed in vacuum for 30-45 min.

[0085] (2) Material pouring: the material uniformly mixed in step (1) was filtered through a 1 μm filter, and then injected into a glass mold, and sealing was performed by using an adhesive tape.

[0086] (3) Primary curing: the mold subjected to material pouring in step (2) was put into a curing furnace to be subjected to primary curing forming according to the following curing time and temperature curves: performing heat insulation for 5 h at an initial temperature of 20° C., raising the temperature to 50-55° C. in 3 h, raising the temperature to 70-75° C. in 5 h, raising the temperature to 80-85° C. in 2 h, raising the temperature to 90-95° C. in 1 h, raising the temperature to 100-105° C. in 2 h, and lowering the temperature to 75-80° C. in 1 h, and a speed was constant in the temperature raising and lowering processes.

[0087] (4) Mold opening, edging and cleaning: mold opening was performed after curing forming, edge chamfering was performed by an edger, and then, surface cleaning was performed.

[0088] (5) Secondary curing: the cleaned lens was put into the curing furnace again to be subjected to secondary curing at a curing temperature of 105-110° C. for 2.5 h.

[0089] After the above preparation was completed, a hardening layer was plated on the surface of the lens by using a dip-coating method, and an antireflecting film layer consisting of silicon dioxide, zirconium dioxide, indium tin oxide and a waterproof layer was plated on the surface of the lens by using a vacuum film plating method.

Comparative Example 4

[0090] A preparation method of a polyurethane-based photochromic resin lens with a refractive index being 1.60 included the following steps:

[0091] (1) 0.02 g of N-dicyclohexylmethylamine was dissolved by 3 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 30-60 min. At the same time, 0.06 g of color changing powder was dissolved by 3 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane for about 60 min to obtain color change liquid. 24 g of 2,5(or 2,6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 1 mg of a mold release agent, 10 g of polytetrahydrofuran glycol and the dissolved color change liquid were added in a proportioning kettle, and were stirred till complete dissolution. The dissolved N-dicyclohexylmethylamine solution was added into a reaction kettle to be stirred for 10 min, cooling was performed to reach about 10° C., 60 g of pentaerythritol tetra(3-mercaptopropionate) and 10 g of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol were added, stirring was performed for 30-60 min in 10° C. water bath, and finally, still standing was performed in vacuum for 30-45 min.

[0092] (2) Material pouring: the material uniformly mixed in step (1) was filtered through a 1 μm filter, and then injected into a glass mold, and sealing was performed by using an adhesive tape.

[0093] (3) Primary curing: the mold subjected to material pouring in step (2) was put into a curing furnace to be subjected to primary curing forming according to the following curing time and temperature curves: performing heat insulation for 5 h at an initial temperature of 20° C., raising the temperature to 50-55° C. in 3 h, raising the temperature to 70-75° C. in 5 h, raising the temperature to 80-85° C. in 2 h, raising the temperature to 90-95° C. in 1 h, raising the temperature to 100-105° C. in 2 h, and lowering the temperature to 75-80° C. in 1 h, and a speed was constant in the temperature raising and lowering processes.

[0094] (4) Mold opening, edging and cleaning: mold opening was performed after curing forming, edge chamfering was performed by an edger, and then, surface cleaning was performed.

[0095] (5) Secondary curing: the cleaned lens was put into the curing furnace again to be subjected to secondary curing at a curing temperature of 105-110° C. for 2.5 h.

[0096] After the above preparation was completed, a hardening layer was plated on the surface of the lens by using a dip-coating method, and an antireflecting film layer consisting of silicon dioxide, zirconium dioxide, indium tin oxide and a waterproof layer was plated on the surface of the lens by using a vacuum film plating method.

[0097] The lenses of the above embodiments and comparative examples were respectively subjected to impact-resistant test, color change performance test and optical performance test, and the results were as shown in Table 1.

TABLE-US-00001 TABLE 1 Performance comparison of lenses of embodiments and comparative examples Impact- Color Visible resistant change depth light Refractive perfor- (visible light transmit- index Sample mance transmittance) tance n.sub.d Example 1 OK   23% 93.3% 1.590 Example 2 OK   20% 92.9% 1.591 Example 3 OK   15% 91.1% 1.592 Example 4 OK   19% 92.0% 1.593 Comparative No   21% 93.5% 1.590 Example 1 Comparative OK   75% 94.1% 1.591 Example 2 Comparative OK 94.5% 94.5% 1.591 Example 3 Comparative Lens white- Lens white- Lens white- Lens white- Example 4 turbid turbid turbid turbid Note: A visible light transmittance test instrument was TM-3; a color change performance test instrument was a transmittance test instrument; impact-resistant test equipment was a 1.6 g small ball falling from a height of 1.27 m, and a test result of no crack after 3 times was regarded as OK; and a refractive index test instrument was an Abbe refractometer.

[0098] From the above table, the polyurethane-based photochromic resin lens of the present invention had high impact-resistant strength, good photochromic effects and high visible light transmittance; when a conventional organic tin initiator was used, or no molecular weight modifier was added, the color change effects were not ideal; and when another proportioning ratio was adopted, the lens white-turbid would be caused, i.e., the lens was non-transparent, and a product was unqualified.

[0099] Each embodiment of the present invention has been described above, and the foregoing description is illustrative, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and technical principles of the described embodiments, and such modifications and variations should also be regarded to be within the protection scope of the present invention.