METHOD OF COLOR-DYEING A LENS FOR GOGGLES AND GLASSES

Abstract

A method of color-dyeing a lens for goggles and glasses, whereby the lens includes a polycarbonate substrate, the method including the steps of: providing a liquid mixture of components including at least one dye or pigment, suitable for color-dyeing polycarbonate and a dispersion medium, whereby the at least one dye or pigment is dispersed as colloids in the dispersion medium; immersing the substrate into the mixture such that the at least one dye or pigment is impregnated into the substrate; and withdrawing the substrate from the mixture. The method is characterized in that the dispersion medium includes a solvent for dissolving the at least one dye or pigment, whereby the solvent includes at least one member selected from the group including an organic alcohol, in particular an aromatic alcohol, in particular benzylic alcohol; a butyl acetate, and a methacrylate ester, in particular methyl methacrylate.

Claims

1. A method of color-dyeing a lens for goggles or glasses, wherein the goggles or glasses comprise a lens comprising a polycarbonate substrate, the method comprising the steps of: providing a liquid mixture comprising at least one dye or pigment, and a dispersion medium, wherein said at least one dye or pigment is dispersed as colloids in said dispersion medium; immersing said polycarbonate substrate into said liquid mixture such that said at least one dye or pigment is impregnated into said polycarbonate substrate; and withdrawing said polycarbonate substrate from said liquid mixture; wherein said dispersion medium comprises a solvent comprising at least one aromatic alcohol, amido-functionalized aromatic compound, butyl acetate, and/or methacrylate ester.

2. The method according to claim 1, wherein the mol ratio between said at least one dye or pigment and said solvent is between 0.05 mol % and 5.00 mol %, 0.06 mol % and 2.00 mol %, 0.07 mol % and 1.00 mol %, or 0.10 mol % and 0.50 mol %.

3. The method according to claim 1, wherein said liquid mixture further comprises a surfactant in a sufficient amount to lower the surface tension or interfacial tension between said liquid mixture and said polycarbonate substrate, and in a sufficient amount to impregnate said polycarbonate substrate with said at least one dye or pigment.

4. The method according to claim 3, wherein said surfactant comprises at least one of linear alkylbenzenesulfonates, lignin sulfonates, fatty alcohol ethoxylates, and alkylphenol ethoxylates, sodium stearate, sodium lauryl sulfate, sodium lauryl ether sulfate, dioctyl sodium sulfosuccinate, perfluorooctanesulfonate (PFOS), perfluorobutanesulfonate, linear alkylbenzene sulfonates (LABs), polyoxyethylene glycol alkyl ethers, polyoxypropylene glycol alkyl ethers.

5. The method according to claim 1, wherein said liquid mixture further comprises a moderating agent.

6. The method according to claim 5, wherein said moderating agent comprises at least one of propylene glycol, 1,4 butane diol, ethylene glycol monobutyl ether, lithium hydroxide, sodium hydroxide, and potassium hydroxide.

7. The method according to claim 1, wherein said dispersion medium and/or said liquid mixture further comprises water.

8. The method according to claim 1, further comprising: heating said liquid mixture thereby forming a heated mixture, before said immersing step and/or during said immersing step, wherein said heating temperature is between 80 C. and the boiling temperature of water, between 90 C. and the boiling temperature of water, or between 90 C. and 96 C.

9. The method according to claim 1, further comprising depositing at least one functional layer onto said polycarbonate substrate.

10. The method according to claim 9, wherein said at least one functional layer comprises at least one of a hard coating (HC), an antireflective coating (AR), a reflecting coating, a polarizing coating, an antifogging coating, a clean coating, and an antistatic coating.

11. The method according to claim 1, wherein said at least one dye or pigment comprises at least one (poly)methane colorants, azo colorants, coumarin colorants, perinone colorants, perilene colorants, amino ketone colorants, anthraquinone colorants, quinophthalone colorants, and pyrazolone colorants.

12. The method according to claim 1, wherein said providing a liquid mixture of components step further comprises providing each of said at least one dye or pigment separately dispersed as colloids in said dispersion medium in an amount not exceeding their saturation limit.

13. The method according to claim 1, wherein said providing a liquid mixture of components step further comprises mixing at least two of said at least one dye or pigment separately dispersed as colloids in said dispersion medium in an amount not exceeding their saturation limit.

14. The method according to claim 12, wherein said providing a liquid mixture of components step further comprises mixing at least two of said at least one dye or pigment separately dissolved in a solvent comprising at least one alcohol, a butyl acetate, and a methacrylate ester.

15. The method according to claim 1, wherein in said immersing step and/or said withdrawing step said polycarbonate substrate is immersed into said liquid mixture with a velocity of 0.5 cm/s to 2 cm/s and/or said polycarbonate substrate is withdrawn from said liquid mixture with a velocity of 0.5 cm/s to 2 cm/s.

16. The method according to claim 1, wherein said solvent comprises at least one of benzyl alcohol and methyl methacrylate.

17. The method according to claim 4, wherein the surfactant comprises at least one of polyethylene glycol ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl ether.

18. The method according to claim 14, wherein said solvent comprises at least one of benzyl alcohol and methyl methacrylate.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0059] The invention will now be described with reference to the single FIGURE of the drawing (FIG. 1) which shows a simplified example of a process according to the invention to obtain tinted polycarbonate lenses.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0060] FIG. 1 shows a graphical representation of a simplified example of method according to the invention to obtain tinted polycarbonate lenses. In a first step 10 the dyes 10-1, 10-2, 10-3 are each separately dissolved in benzylic alcohol 10-4 up to their solubility limit. In the example three dyes 10-1, 10-2, 10-3, for example, blue, red and yellow, are dissolved in benzylic alcohol 10-4 forming dye solutions 20-1, 20-2, 20-3. The dye solutions 20-1, 20-2, 20-3 in benzylic alcohol 10-4 are mixed in a second step 20 in the required amounts c (see Table 1) and in a further step 30 supplemented with surfactants 30-1, 30-2, first dipropylene glycol monomethyl ether (DPM) then aqueous solution of potassium hydroxide (for example, Deconex OP141) to obtain a brown solution.

TABLE-US-00001 TABLE 1 Recipe for Brown Tint MACROLEX New Red MACROLEX Yellow 6R TBLS Blue 3R DPM OP141 concentration c Methine- dyestuff Anthraquinone dipropylen aqueous dyestuff mixture dyestuff glycol mono solution of methylether potassium hydroxide ml/1 1.7 11.0 3.7 4.8 0.2
The missing volume share is filled in step 40 by deionized water 40-1. The mixing steps 20, 30, 40 are performed at room temperature under vigorous stirring 50. The stirring step 50 is conducted via a magnetic stirrer 50-1. The tinting bath is indicated in the drawing via the reference numeral 50-2, the mixture via reference numeral 50-3.

[0061] In step 60 the mixture is stirred and heated to 94 C., which yields a homogeneous dispersion 50-3a. Then a polycarbonate lens 70-1, hereinafter referred to as polycarbonate substrate in order to distinguish from a coated lens, in appropriate lens holder 70-2 is fully submerged in the homogenized mixture 50-3a in step 70. The time in the tinting bath 50-3 according to step 80 has to be adjusted according to desired degree of absorption. In step 90 the tinted polycarbonate lens 90-1 is withdrawn from the tinting bath 50-3a via the lens holder 70-2. Table 2 summarizes the results for different time schedules t and their respective luminous transmission T in the visible spectral range, measured under an incidence angle of 2 and standard illumination D65.

TABLE-US-00002 TABLE 2 Optical Analysis of Polycarbonate Lenses Tinting time t 30 60 120 300 (min) Luminous 42 35 24 16 Transmission T (%), D65, 2

[0062] Subsequently the usual Rx treatment 100 can be continued, in particular hard and anti-reflective coating HC, AR, followed by Cut, Edge and Fit processes C, E & F resulting in a pair of glasses or spectacles 110, respectively.

[0063] The recipe shown in Table 1 leads to a brown lens color.

[0064] It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.