JPH0457980A - Dyeing method for plastic lens - Google Patents

Abstract

PURPOSE:To accomplish the uniform, stable dyeing of plastic lens by treating the surface of plastic lens with a specific carrier followed by immersing and treating the resultant lens in a disperse dye-contg. dyeing bath. CONSTITUTION:Plastic lens, esp. consisting of a low water-absorptive resin containing aromatic ring and/or halogen element is immersed in an aqueous solution (or organic solvent solution) of a carrier of the formula (R<1> and R<2> are each H, aliphatic hydrocarbon or aromatic hydrocarbon; R<3> is 2-10C alkylene; where, R<1> and R<2> are not H at the same time; (m) is 1-10) to treat the surface of said lens followed by treating the resultant lens in a disperse dye-contg. dyeing bath at 50-l00 deg.C for 5sec to 1hr or so, thus accomplishing the objective uniform dyeing of the lens with a desired hue.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to dyeing plastic lenses, particularly plastic lenses made of a resin material with low water absorption containing an aromatic ring and/or a halogen element, at a desired dyeing speed. good(,
This invention relates to a method for dyeing uniformly, without spots, and stably.

[Conventional technology 1] With the trend of shifting from inorganic glass lenses to plastic lenses becoming established year by year, poly(diethylene glycol bisallyl carbonate) (hereinafter referred to as
There is an extremely strong demand for a resin material that can replace the plastic glass lens (abbreviated as CR39) from which thinner and lighter plastic eyeglass lenses can be made. These demands can be realized by increasing the refractive index of resins, and in recent years a wide variety of high refractive index resin materials have been proposed, and some of them have been put into practical use. However, many of these high refractive index resin materials contain aromatic rings and/or halogen elements as their structural characteristics, and therefore have strong hydrophobicity and low water absorption. It has the disadvantage of being difficult to dye.

Currently, the lineup of dyes for CR39 has been completed and is in widespread use, so there is a need for resin materials to come up with ways to use dyes and dyeing equipment for CR39 as they are. It is preferable that the water absorption rate is low in order to maintain surface accuracy.
In order to be well dyed with disperse dyes, a certain degree of water absorption is required, which is a trade-off between the two and is an obstacle to the development of resin materials. For example, in the case of plastic eyeglass lenses whose water absorption rate is greater than 0.9% by weight when immersed in water at 100°C for 2 hours, dyeing is relatively easy, and surfactants and salts such as sodium hydrogen phosphate are used as dyes. It is also possible to further improve dyeability by adding it to an aqueous solution, but
In the case of a low water absorption plastic eyeglass lens whose water absorption rate is less than 0.9% by weight when immersed in water at 100° C. for 2 hours, it can hardly be dyed by the same dyeing method as above.

To improve this drawback, methods have been proposed in which carriers such as diphenyl, phenol, and salicylic acid are added to the aqueous dye solution, but although these methods can improve the dyeing speed, they do not reduce the uniformity of the dyeing. This is difficult to secure and is not an adequate method.

[Problem to be Solved by the Invention J] An object of the present invention is to dye plastic lenses, particularly plastic lenses made of a low water absorption resin material containing an aromatic ring and/or a herogen element, at a desired dyeing speed and with good color tone. The object of the present invention is to provide a method for dyeing plastic lenses that can be dyed uniformly, without spots, and stably.

[Means to solve the problem]

The present invention provides a method for dyeing a plastic lens that achieves the above objects.

That is, the present invention relates to a method for dyeing a plastic lens, which is characterized in that, when dyeing a plastic lens by immersing it in an aqueous disperse dye solution, the surface of the plastic lens is treated in advance with a carrier represented by the bottom (I) below. .

R'O→-R"O+=-R" fl) (wherein, R
', R'' represents a hydrogen atom, an aliphatic hydrocarbon residue or an aromatic hydrocarbon residue, and R3 represents an unsubstituted or substituted alkylene group having 2 to 10 carbon atoms, provided that R1 and R2 are hydrogen at the same time. It cannot be an atom. m is 1-10
is an integer. ) In the present invention, the carrier used to pre-treat the surface of the plastic lens is represented by the following general formula (1), as described above.

R'O-←-R"0-)-t-R" (1) Here, in formula (I), when R' and R" are aliphatic hydrocarbon residues, the number of carbon atoms is 1 to 10 Examples include linear or branched alkyl groups, and when R' and R'' are aromatic hydrocarbon residues, examples include phenyl groups and halogenated phenyl groups.

Further, when R3 is an unsubstituted alkylene group, examples include ethylene, 1,3-propylene, 1,2-propylene, etc., and examples of substituents for R3 include -OR'
(However, R4 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.).

Specific examples of the carrier represented by general formula (I) include:
Ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monooctyl ether, ethylene glycol monophenyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1.2 −
Propanediol monomethyl ether, 1.2-propanediol monoethyl ether, 1.2-propanediol monobutyl ether, 1.2-propanediol monophenyl ether, 1.2-propanediol dimethyl ether, 1.2-propanediol diethyl ether , 1.2-propanediol dibutyl ether, 1.
3-propanediol monomethyl ether, 1.3-propanediol monopropyl ether, 1.3-propanediol monooctyl ether, 1.3-propanediol dimethyl ether, 1.3-propanediol dibutyl ether, 1.3-propanediol diphenyl ether, 1.3-butanediol monomethyl ether, 1.3-butanediol monobutyl ether, 1.3
-Butanediol monophenyl ether, 1,3-butanediol diethyl ether, 1,4-butanediol monohexyl ether, 1,4-butanediol dimethyl ether, 1,6-hexanesiol monomethyl ether, 1.6-hexanethiol mono butyl ether,
1.6-hexanethiol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether , bis(l,2-propanediol) monomethyl ether,
Bis(1,2-propanediol) monophenyl ether, bis(1,2-propanediol) diethyl ether, bis(1,2-propanediol) dibutyl ether, bis(1,3-propanediol) monoethyl ether, Bis(1,3-propanediol) monooctyl ether, 1,2-dimethoxyethanol, 2-methoxypropylene glycol, 2,3-dimethoxy normal propyl alcohol, 4-hydroxy-1,4-dimethoxy-2,2-dimethyl Butane, 1-methoxy-1
, 2-diphenyloxypropane, bis(2-methoxy-1-hydroxymethylethyl) ether, and the like. Two or more of these carriers may be used in combination.

When treating the surface of a plastic lens with a carrier, it may be treated directly with the carrier alone, or it may be treated with an aqueous or organic solvent solution prepared by diluting the carrier with water or an organic solvent.The carrier may be used alone. Whether to use it in the form of an aqueous solution or an organic solvent solution takes into consideration the characteristics of the carrier used, such as whether the carrier is liquid or solid, and whether it is soluble in water or an organic solvent. and decide accordingly.

As an organic solvent used to prepare the organic solvent solution of the carrier, it does not attack the plastic lens.
There are no particular restrictions as long as the carrier can be dissolved uniformly, but from the viewpoint of handling management, it is desirable to have low toxicity and high volatility when heated.
Specific examples of solvents include ethanol, toluene, xylene, cellosolve acetate, ethyl cellosolve, and DMF.
, DMSO, etc.

The concentration of the carrier in the aqueous solution or organic solvent solution varies depending on the carrier, so it cannot be absolutely defined, but it is generally preferably in the range of 1 to 99.9% by weight, and less than 1% by weight will not have a substantial effect. I can't get it.

As a method for treating the surface of a plastic lens, a dipping method is preferred.

When the surface of a plastic lens is treated with a carrier alone, an aqueous carrier solution, or an organic solvent solution of the carrier, the temperature of the carrier alone, the aqueous carrier solution, or the organic solvent solution of the carrier is 25 to 120°C, preferably 40 to 8°C.
It is in the range of 0°C. The immersion time in the carrier of the plastic lens, the water droplet solution of the carrier, or the organic solvent solution of the carrier is in the range of 5 seconds to 1 hour, preferably 5 seconds to 15 minutes.

Various dispersants, antioxidants, stabilizers, and other additives can be added to the carrier, an aqueous solution of the carrier, or an organic solvent solution of the carrier, as necessary, within a range that does not impair its performance.

The plastic lens thus immersed in a carrier, an aqueous solution of the carrier, or an organic solvent solution of the carrier is then immersed in an aqueous disperse dye solution for dyeing.

In addition, in the present invention, it is necessary to pre-treat the plastic lens with a carrier, and if the plastic lens is not pre-treated with a carrier and is dyed by mixing the carrier with an aqueous dye solution, the dyeing speed and dyeing may be affected. Although it can improve the appearance of spots, it has the disadvantage of poor resistance to weather fading.

The dye used in the method of the present invention is not particularly limited as long as it is a disperse dye, and examples include Vista Blacks Blue, Vista Blacks Yellow C, Vista Blacks Red, Vista Blacks Gray, Seiko Brown D,
Examples include Diacoat Green D and Nikon Gray H. These can be used alone or in combination depending on the desired color tone. Further, dyeing aids (for example, Nikon Orma 70, Seiko Browns, etc.) may be added to the dye solution as necessary.

The concentration of the disperse dye in the aqueous disperse dye solution is preferably in the range of 0.05 to 2% by weight. Further, the concentration of the dyeing aid used as necessary is preferably in the range of 0.1 to 2% by weight.

The temperature and time for dyeing surface-treated plastic lenses cannot be determined unconditionally as they vary depending on the density of the dyeing, but they are usually in the range of 50 to 100°C and the desired dyed plastic is dyed in about 5 seconds to 1 hour. A lens is obtained. It is preferable to stir the disperse dye aqueous solution in order to improve the dyeing effect.

Note that the color tone of the plastic lens is similar to that of mixing paints, and by appropriately mixing the above-mentioned disperse dyes, it is possible to dye the plastic lens to a desired color tone.

The plastic lens used in the present invention is not particularly limited as long as it is difficult to dye with ordinary dyeing methods, but it is preferably made of a resin material containing an aromatic ring and/or a halogen element in its structure. Thickness 3
It is particularly effective for plastic lenses with a water absorption rate of 0.9% by weight or less when immersing an absolutely dry cylindrical sample of +++a+, 50m+mφ in water at 1°C for 2II! Typical examples of lenses include polystyrene, a copolymer of tetrabromobisphenol A dimethacrylate and styrene, a copolymer of 4.4゛-bis(methacryloylthio) diphenyl sulfide and styrene, and 3,3゛-divinylbiphenyl. and 4.
4'-(2-acryloyloxyethyloxy) -2
, 2'-diphenylpropane copolymers, and diallylisophthalate/benzyl methacrylate copolymers.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

In addition, in Examples and Comparative Examples, dyeing speed, staining spots, and resistance to weather fading were determined by the following methods.

(1) Dyeing speed - Seiko Brown D density of 2D lens at 87℃ is 2
It was immersed in a dyeing solution of % by weight for 5 minutes and dyed. The transmittance after staining was measured and evaluated in the three stages shown below.

○: Good (stained (transmittance at 550ns is less than 70%))
Δ: Slightly stained 1550n Transmittance in intestine is 70% or more 8
(Less than 0%)
% or more) (2) Staining spots The lenses were stained under the same conditions as in (1) above, and the stained spots on the lenses were visually observed and evaluated on the following three scales.

○: No staining spots (with the convex side facing down and the lens rotated and no spots found) △: Some staining spots (with the concave side facing down and the lens rotating and no spots found) × : There are staining spots (the spots can be seen by rotating the lens with the concave side facing down) (3) Weather resistance - 2D lens with Seiko Brown D concentration of 2 at 87℃
% by weight dyeing solution until the transmittance reached 60%, and after subjecting it to a 30-hour weather test using a sunshine weather meter, the transmittance was measured and evaluated in the following three stages.

○: Transmittance less than 65% △: Transmittance 65% or more and less than 70% X: Transmittance 70% or more Example 1 Tetrabromobisphenol A dimethacrylate 75 g
A resin composition consisting of 25 g of styrene and 0.5 g of 2,2°-azobisisobutyronitrile was cured by a casting method to obtain a 2D lens. This lens is 8
The sample was treated by immersion in 1,2-propanediol diethyl ether heated to 0°C for 3 minutes, and then washed with isopropyl alcohol in an ultrasonic cleaner. Next, the cleaned lens was dyed by immersing it in a dyeing solution at 87° C. in which 2 g of a dye (Seiko Brown D) was mixed with water lI2 and stirred at 87° C. for 30 minutes to uniformly disperse it. 550na
The transmittance at + was 65%, which was the same staining rate as a lens made of CR39, and there were no staining spots.

Comparative Example 1 In Example 1, the surface of the lens was not treated with 1.2-propanediol diethyl ether, but a staining solution in which 1.2-propanediol diethyl ether was added to the staining solution used in Example 1 was used. Other than that, dyeing was carried out in the same manner as in Example 1. The results are shown in Table 1.

Examples 2 to 16 and Comparative Examples 2 to 8 2D lenses of various compositions were molded by the same method as in Example 1, and then molded with a carrier, an aqueous solution of the carrier, or a carrier under the conditions shown in Tables 1 and 2. After cleaning the lens, the lens was immersed in an organic solvent solution of 1, and then dyed in the same manner as in Example 1. The results are shown in Tables 1 and 2.

(Margin below) (Note 1) The resin materials (cured products) of the lenses used in Tables 1 and 2 are as follows.

The numbers in parentheses represent the weight composition ratio.

A: Tetrabromobisphenol A dimethacrylate/
Styrene copolymer (75/25) refractive index 1.59 Water absorption 0.51% by weight B: 4,4'-bis(methacryloylthio) diphenyl sulfide/styrene copolymer (67/33) refractive index 1.66 Water absorption rate @ 0.29% by weight Carbon diallyl isophthalate/benzyl methacrylate copolymer (50150) Refractive index 1.56 Water absorption rate 0.65% by weight Umbrella - Thickness: 3cm Ig, water absorption rate when an absolutely dry cylindrical sample of 50 lφ was immersed in 100°C water for 2 hours (Note 2) The dyes used in Tables 1 and 2 are as follows.

SBD + Seiko Brown D (Note 3) The carriers used in Tables 1 and 2 are as follows.

PGME: 1.2-Propanediol monoethyl ether EGMB: Ethylene glycol monobutyl ether DEGME Nidiethylene glycol monoethyl ether DECDE Nidiethylene glycol diethyl ether EGDB: Ethylene glycol dibutyl ether HDM
M: 1,6-hexanesiol monomethyl ether DPGME: Bis(1,2-propanediol) monomethyl ether EGMP: Ethylene glycol monopropyl ether PGco 1,2-propanediol DEG Nidiethylene glycol DPG Nidipropylene glycol 0-PP: Ortho Phenylphenol MPG: 2-Methoxypropylene glycol [Effects of the Invention] According to the method of the present invention, plastic lenses can be dyed uniformly and without spots at a desired speed, which was difficult with conventional general dyeing methods. can.

The plastic lenses obtained by the present invention are useful as prescription or non-prescription sunglasses and fashion glasses.

Claims (1)

[Claims] A method for dyeing a plastic lens, which comprises treating the surface of the plastic lens in advance with a carrier represented by the following general formula (I) when dyeing the plastic lens by immersing it in an aqueous disperse dye solution. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R^1 and R^2 represent hydrogen atoms, aliphatic hydrocarbon residues, or aromatic hydrocarbon residues, and R^3 is the number of carbon atoms. represents an unsubstituted or substituted alkylene group of 2 to 10. However, R^1 and R^2 are never hydrogen atoms at the same time. m is an integer of 1 to 10.)