JPH04119178A - Dyeing of plastic lens - Google Patents

Abstract

PURPOSE:To obtain a dyed plastic lens resistant to fading with ultraviolet ray and heat by dyeing a specific plastic lens with an aqueous solution of a disperse dye containing a specific amount of nickel p-toluenesulfonate in the solution. CONSTITUTION:A dyed plastic lens resistant to fading of the dye with ultraviolet ray, heat, etc., can be produced by dyeing a plastic lens having a relatively high refractive index and containing aromatic ring, halogen atom (excluding fluorine), sulfur atom, etc., (e.g. copolymer of polystyrene diacrylate and CR-39) at 50-100 deg.C in a dyeing bath produced by adding 0.001-5wt.% of nickel p- toluenesulfonate to an aqueous solution containing a disperse dye.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to dyeing a plastic lens with a relatively high refractive index made of a resin material containing an aromatic ring, a halogen atom other than fluorine, or a sulfur atom to produce eyeglasses or This invention relates to a dyeing method for suppressing the deterioration (fading) of dyes caused by ultraviolet rays and heat during use when used as sunglasses.

[Conventional technology] In recent years, the shift from inorganic glass lenses to plastic lenses has become more established.This is because plastic lenses are lightweight and can be dyed, making them easily available in a wide variety of colors. Advantages are said to be the main reason. However, diethylene glycol bisallyl carbonate (hereinafter abbreviated as CR-39) polymer, which is the main resin material in plastic lenses, has a small refractive index, which makes the lens thicker. There is an extremely large demand for resin materials. In response to this demand, a wide variety of high refractive index resin materials containing aromatic rings, halogen atoms other than fluorine, or sulfur atoms have been proposed, and some have been put into practical use. However, these plastic lenses made of resin materials with high refractive index are easily deteriorated by ultraviolet rays and heat, making CR-
Compared to plastic lenses using No. 39 polymer as a resin material, they have the disadvantage that the deterioration (fading) of the dye is greater.

In order to improve this drawback, phenol-based, piperidine-based, acid-based, phosphorus-based antioxidants, benzophenone-based antioxidants, etc.
Attempts have been made to add benzotriazole-based ultraviolet absorbers, but not only are they not sufficiently effective, but they also cause new defects such as yellowing the lens itself and making the film more likely to crack. I'm letting you do it.

[Problem to be Solved by the Invention 1] The present invention dyes a plastic lens made of a resin material with a relatively high refractive index that contains an aromatic ring, a halogen atom other than fluorine, or a sulfur atom to prevent it from deteriorating against ultraviolet rays and heat.
The purpose of the present invention is to provide a dyeing method for producing dyed lenses that are resistant to fading.

Means for Solving the Problems 1 The present invention provides a method for dyeing plastic lenses that achieves the above objects.

That is, in the present invention, when a plastic lens having a relatively high refractive index made of a resin material containing an aromatic ring, a halogen atom other than fluorine, or a sulfur atom is immersed in an aqueous dye solution and dyed, the aqueous dye solution is 0.001～
This invention relates to a method for dyeing plastic lenses characterized by containing 5% by weight of nickel paratoluenesulfonate.

Examples of the plastic lens made of a resin material containing at least one of an aromatic ring, a halogen atom excluding fluorine, and a sulfur atom used in the present invention include polystyrene, a copolymer of diallyl phthalate and CR-39,
, 4′-bis(2-methacryloyloxyethyloxy)-2,2°-diphenylpropane and 3.3°-divinylbiphenyl copolymer, 2.2°-bis[3,5-
Copolymer of dibromo-4-(2-methacryloyloxyethyloxy)phenyl]propane and parachlorostyrene, copolymer of xylylene diisocyanate and dimercaptophenyl sulfide, 4.4°-bis(methacryloylthio)diphenyl Examples include lenses made of resin materials such as copolymers of sulfide and styrene. Antioxidant rJ= agents, ultraviolet absorbers, bluing agents, mold release agents, etc. can be added to these resin materials as necessary, within a range that does not impair the effects of the present invention.

In the present invention, M of nickel paratoluenesulfonate added to the aqueous dye solution is in the range of 0.001 to 5% by weight, preferably 0.1 to 1% by weight, based on the aqueous dye solution. If it is less than 0.0% by weight, there is no substantial effect, and if it exceeds 5% by weight, the lens will become mottled, which is not preferable.

The dispersed dye used in the method of the present invention is not particularly limited, but examples include Vista Black Blue Vista Black Yellow C, Vista Black Red, Vista Black Gray, Seiko Brown D, and Diamond Coat Green D.
, Guyacote Amber D, Nikon Gray H, etc. These dispersed dyes may be blended with dye auxiliaries such as Nikon Orma 70 and Seiko Brauns, if necessary, and the concentration of the dye is preferably in the range of 0.01 to 2% by weight. If the amount is less than 2% by weight, the lens will hardly be dyed, and if it exceeds 2% by weight, it will be difficult to disperse and cause defects such as staining spots, which is not preferable. A surfactant may be added to these disperse dye aqueous solutions as necessary.

The time and temperature for dyeing plastic lenses are:
Although it cannot be determined unconditionally because it varies depending on the depth of the dyeing and the concentration of the dye, the desired dyed plastic lens can usually be obtained in the range of 50 to 100° C. for about 5 seconds to 17 il per square inch.

[Example 1] Hereinafter, the present invention will be explained in more detail by giving Examples and Comparative Examples.

In Examples and Comparative Examples, staining spots and weathering resistance were determined by the following methods.

(1) Dyeing spots Use each dye aqueous solution to dye a -2D lens to a transmittance of 80% or less. Rotate the lens with the convex side facing up. If the presence of spots cannot be confirmed, mark it as ○, and if you can, mark it as ×. did.

(2) Weather-fading resistance - Using a 2D lens, dye it with each dye aqueous solution to a transmittance of 50%, and apply this lens to a sunshine weather meter (
(hereinafter abbreviated as SWM), the transmittance was measured after 24 hours of exposure, and those with a difference in transmittance (8T) of 4% or less were marked as ○.
5% or more and less than 10% was evaluated as △, and 10% or more was evaluated as ×.

Example 1 A lens was obtained by polymerizing a composition consisting of 50 parts of diallyl phthalate, 2 parts of CR-3950, and 3 parts of benzoyl peroxide by a casting method.

This lens was immersed in an aqueous dye solution prepared by the method described below and dyed until the transmittance at a wavelength of 550 nm reached 50%. Dye aqueous solution is dye (
2 g of Seiko Brown D), 3 g of Seiko dyeing aid, and 1 g of nickel para-toluenesulfonate were added, and the mixture was stirred and mixed at 88° C. for 30 minutes. SWM dyed lenses
was exposed for 24 hours.

The transmittance after exposure showed a slight change of 52%, and the color tone was good with almost no change. The results are shown in Table 1.

Example 2 Same as Example 1 except that 0.05 g of nickel balatoluenesulfonate was used (dyed lenses were also dyed in the same way. After SWM exposure, the large diameter pass rate was as small as 54%, and there was no change in color tone. The results are shown in Table 1.The results are shown in Table 1.

Example 3 A dyed lens was obtained in exactly the same manner as in Example 1, except that IOg was used as nickel balatoluenesulfonate. SW
M! ! The transmittance of the large diameter was as small as 52%, and no change in color tone was observed, which was good. The results are shown in Table 1.

Example 4 2.2°-bis[3,5-dibromo-4-(2-methacryloyloxyethyloxy)phenyl]propane 70
parts and 30 parts of 3,3°-divinylbiphenyl, 2,2°-
A lens was obtained by polymerizing a composition containing 0.5 part of azobisisovaleronitrile. This lens was dyed in the same manner as in Example 1. SWM, the transmittance after 1 exposure was as small as 53%, and no change in color tone was observed, which was good. The results are shown in Table 1.

Example 5 A dyed lens was obtained in the same manner as in Example 4 except that Nikon Gray H was used as the dye. The large diameter pass rate after SWM exposure was as small as 54%, and almost no change in color tone was observed, which was good. The results are shown in Table 1.

Example 6 2.2°-bis[3,5-dibromo-4-(2-methacryloyloxyethyloxy)phenyl]propane 30
Part, 1. 1, 40 parts of 1-trimethylolpropane trimethacrylate, 40 parts of parachlorostyrene, and 2
, 0.5 part of 2'-azobisisovaleronitrile was polymerized to obtain a lens. This was dyed in the same manner as in Example 1 to obtain a dyed lens.

After exposure to SWM, the large diameter pass rate remained almost unchanged at 51%. Further, the color tone was also good with no change observed. The results are shown in Table 1.

Comparative Example I A dyed lens was obtained by dyeing in exactly the same manner as in Example 1 except that nickel balatoluenesulfonate was not added to the aqueous dye solution. SWMI! The large diameter ratio after dew was 63%, and the color was significantly faded. The color tone also increased in surface chromaticity and was significantly different from the color tone immediately after dyeing. The results are shown in Table 1.

Comparative Example 2 A dyed lens was obtained by dyeing in the same manner as in Example 1 except that 60 g of nickel balatoluenesulfonate was used. The dyed lens had staining spots and was found to be defective. After exposure to SWM, the large diameter pass rate was as small as 51%, and no change in color tone was observed. The results are shown in Table 1.

Comparative Example 3 A dyed lens No. 11 was dyed in the same manner as in Example 4 except that nickel balatoluenesulfonate was not used.

After exposure to SWM, the large diameter pass rate changed significantly to 70%, and the color tone also became more yellow, which was significantly different from that immediately after dyeing, which was poor. The results are shown in Table 1.

Comparative Example 4 A dyed lens was obtained by dyeing in the same manner as in Example 5 except that nickel balatoluenesulfonate was not used. S
After exposure to WM, the large-diameter pass rate changed significantly to 68%, and the color tone also became more blue, which was significantly different from immediately after dyeing. The results are shown in Table 1.

(Blank below) [Effect of the invention 1 As is clear from the above, according to the method of the present invention, a plastic lens with a relatively high refractive index made of a resin material containing an aromatic ring, a halogen atom other than fluorine, or a sulfur atom can be used. , a dyed lens that is resistant to deterioration (fading) due to ultraviolet rays and heat can be obtained. The dyed plastic lenses obtained according to the present invention are useful as prescription or non-prescription sunglass spectacle lenses and fashion spectacle lenses.

Claims (1)

[Claims] When dyeing a plastic lens made of a resin material containing at least one of an aromatic ring, a halogen atom excluding fluorine, and a sulfur atom by immersing it in an aqueous disperse dye solution, the dye aqueous solution contains 0.001 to 5% by weight of para. A method for dyeing plastic lenses characterized by containing nickel toluenesulfonate.