JPH105672A - Gradient dyeing method of plastic lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of the boundary line between a dyed part and an undyed part by adding a foaming agent to a dyeing soln. when gradient dyeing is applied to a plastic lens and stirring the dyeing soln. to form a foam phase between a liquid phase and a gas phase and immersing the lens up to a part where a concn. gradient is desired to be applied. SOLUTION: When gradient dyeing being half dyeing forming a concn. gradient is applied to a plastic lens for glasses, a foaming agent is added to a dyeing soln. in order to obscure the boundary line between a dyed part and an undyed part and the dyeing soln. is stirred to form a foam phase between a liquid phase and a gas phase and the lens is subsequently immersed up to a part where a concn. gradient is desired to be formed and gradually drawn up to be treated. At this time, various dyes such as a disperse dye or a reactive dye are used in the dyeing soln. and the foaming agent is pref. added to the dyeing soln. within a range of 0.05-1wt.% and, for example, polyethylene glycol alkyl phenol is designated. The foam phase is pref. formed at a height of 0.1-6cm from the interface of the dyeing soln.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of dyeing a plastic lens with a concentration gradient, that is, a method of performing gradient dyeing.

[0002]

2. Description of the Related Art Conventionally, plastic lenses for eyeglasses are dyed from the viewpoint of their fashionability, etc.
For example, half-staining with a concentration gradient is performed. The latter gradient staining is performed by immersing the lens in a staining bath to a portion where a color density gradient is desired, and then slowly pulling up the lens. However, in this method,
The boundary line between the lens part immersed in the staining solution and the lens part not immersed, that is, the boundary line between the stained part and the unstained part clearly appears, and a natural transition to staining is not obtained, and the appearance is Inferior, there was a sense of incongruity in actual use.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for gradient dyeing of plastic lenses which does not produce sharp boundaries in the dyed product.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a boundary between a dyed portion and an undyed portion can be blurred by forming a bubble phase between a liquid phase and a gas phase in a dyeing tank. It was completed based on the knowledge that That is, in the gradient dyeing method for a plastic lens of the present invention, a foaming agent is added to a dyeing solution, and a stirring is performed to form a foam phase between a liquid phase and a gaseous phase. It is characterized in that it is immersed to the desired part and then gradually lifted.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the plastic lens is not particularly limited, and the plastic lens base is made of various plastic lens materials such as diethylene glycol bisallyl carbonate polymer, polyurethane resin, acrylic resin, polycarbonate resin and polystyrene. May be something.

Various dyes such as disperse dyes, reactive dyes, acid dyes and cationic dyes can be used in the dyeing solution used in the present invention. More specifically, anthraquinone type, phthalocyanine type, nitro type, , Quinoline-based and lactone-based dyes can be used. Further, a cationic surfactant, a nonionic surfactant, an anionic surfactant, or the like can be added to the staining solution as a dispersant. Generally, the dyeing solution used in the present invention is the same as a normal dyeing solution except that it contains a foaming agent.

[0007] The foaming agent is not particularly limited. Examples thereof include polyethylene glycol alkylphenol, sodium phosphate of organic phosphate, aliphatic alcohol ethoxylate, diethanolamine lauryl sulfate,
Examples thereof include sodium lauryl ether sulfate, ammonium lauryl sulfate, diethanolamine cocoamide, alkyl allyl sulfonate alkanolamide, coco alkanolamide, lauryl alkanol amide, sodium lauryl sulfate, and coco fatty acid diethanolamine.

The foaming agent is contained in the dyeing solution in an amount of 0.05 to 1% by weight.
It is preferable to add in the range. The amount of the foaming agent added is 0.
If the content is less than 05% by weight, a sufficient foaming effect cannot be obtained,
If the content exceeds 1% by weight, the dyeing properties will be reduced, and the dyeing solution will take a long time.
In the present invention, the dyeing solution to which the above-mentioned foaming agent has been added is stirred to generate air bubbles, and an intermediate foam phase is formed between the liquid phase and the gas phase. This foam phase is preferably formed at a height of 0.1 to 6 cm from the interface of the dyeing solution,
More preferably, it is formed at a height of 1 to 3 cm. If the foam phase is less than 0.1 cm from the interface of the dyeing solution, a sufficient border blurring effect cannot be obtained, and if it exceeds 6 cm, it becomes impossible to sufficiently perform lens staining.

As described above, the lens is immersed in the dyeing solution in which the foam phase has been formed, to the portion where the concentration gradient is desired, and is left standing for a predetermined time if necessary. The bubble phase acts to scrape off the staining solution attached to the stained lens, and the boundary between the stained portion and the unstained portion can be blurred. After staining, wash the lens with water,
For example, by removing stains on the lens surface with acetone or the like, there is no boundary line between a stained portion and an unstained portion, and a beautiful colored lens having a naturally-graded density can be obtained.

[0010]

Next, the present invention will be described in detail based on examples, but the present invention is not limited thereto.

Example 1 To a dyeing solution obtained by dissolving 2 g of MLP-red2 (a dye manufactured by Mitsui Toatsu Dye Co., Ltd.) and 2 g of MLP-yellow 2 (a dye manufactured by Mitsui Toatsu Dye Co., Ltd.) in 1 liter of water as a brown mixture. Sodium salt of an organic phosphoric acid ester was added as a foaming agent to a concentration of 0.2% by weight, and the mixture was stirred with a simple whisk for 2.5 minutes to form a 1.5 cm foam phase.
Set the plastic lens in a special lens holder, and immerse it in the staining solution for about 4 minutes using the dyeing device that moves the holder up and down to the part you want to stain. Pull up. afterwards,
After washing with water and removing dirt on the lens surface with acetone, a clean gradient-stained plastic lens without boundaries between stained and unstained parts was obtained.

Example 2 To a dyeing solution obtained by dissolving 2 g of MLP-red2 (a dye manufactured by Mitsui Toatsu Dye Co., Ltd.) and 2 g of MLP-yellow 2 (a dye manufactured by Mitsui Toatsu Dye Co., Ltd.) in 1 liter of water as a brown mixture. As a foaming agent, polyethylene glycol alkylphenol is added to be 0.2% by weight,
Stirred with a simple whisk for 2.5 minutes to form a 1.5 cm foam phase. Set the plastic lens in a special lens holder, and immerse it in the staining solution for about 4 minutes using the dyeing device that moves the holder up and down to the part you want to stain. Pull up.
After that, the lens was washed with water and stained on the lens surface with acetone. As a result, a clear gradient-stained plastic lens having no boundary between a stained portion and an unstained portion was obtained.

Comparative Example The same dyeing solution as in Example 1 was used except that no foaming agent was used, and dyeing was carried out in the same manner as in Example 1 except that no foaming was performed. A line has come out. Further, stains of the dye remain on the lens surface, which is not preferable as a dyeing condition.

[0014]

According to the present invention, there is no boundary between the stained portion and the unstained portion, no stain of the dye remains on the lens surface, and a clean gradient dyeing can be obtained by a simple operation at a low cost.
A highly fashionable plastic lens can be provided.

Claims (3)

[Claims] 1. A foaming agent is added to a dyeing solution and stirred to form a foam phase between a liquid phase and a gaseous phase. Then, the lens is immersed to a portion where a concentration gradient is desired, and then gradually. A gradient dyeing method for plastic lenses, characterized by being raised up to 2. A foaming agent of 0.05 to 1% by weight in a dyeing solution.
2. The method according to claim 1, wherein the compound is added so as to have a concentration of
The method for gradient staining of the plastic lens as described. 3. The foam phase is 0.1 to 6 c from the interface of the dyeing solution.
The gradient staining method for a plastic lens according to claim 1, wherein the plastic lens is formed at a height of m.