JPH0646270B2 - Plastic eyeglass frames - Google Patents

Description

TECHNICAL FIELD The present invention relates to a plastic eyeglass frame, and more particularly to an eyeglass frame dyed with a dye.

BACKGROUND OF THE INVENTION There are a metal frame and a plastic frame as an eyeglass frame, and plastic is often used especially in a frame for the purpose of fashionability because of its excellent moldability and coloring property.

When thermoplastic celluloid or acetyl cellulose is mainly used as a plastic material for eyeglass frames, a metal core rod is used to compensate for lack of mechanical strength, and it is heavy and design-friendly. There were also restrictions.

However, recently, thermosetting resins such as epoxy resins having excellent strength have come to be used, and with the reduction in weight, colorful frames with various designs have become popular.

[Problems of conventional technology]

Epoxy resin is widely used as a material for eyeglass frames because it has excellent mechanical properties. To color it, there are a method using a pigment and a method using a dye.

Generally, when a chemically stable pigment is used, coloring durability is excellent, but in this case, there is a limitation that the colored material becomes opaque.

On the other hand, when dyeing with a dye, it is decoratively preferable because a transparent colored product can be obtained, but in this case, the phenomenon of discoloration due to ultraviolet rays or visible light cannot be ignored, and there is a problem from the viewpoint of durability. Becomes

[Object and Structure of Invention]

Therefore, an object of the present invention is to prevent discoloration in an epoxy resin eyeglass frame that is dyed with a dye.

For the above purpose, in the present invention, a polyurethane resin is coated on a base made of an epoxy resin, and the coating layer is dyed with a dye to form a dye layer, and if desired, an ultraviolet absorber may be contained in the dye layer. I chose

The present inventors have observed the fading phenomenon under irradiation of ultraviolet rays and visible light in various plastics dyed with a dye, and the remarkable fading observed in epoxy resins is closely related to the presence of hydroxyl groups based on secondary alcohols. It was found that the active hydrogen of the hydroxyl group is involved in the fading mechanism.

On the other hand, it has been found that the fading phenomenon is practically negligible in a material that does not contain active hydrogen and is not easily oxidized, such as a polyurethane resin having a urethane bond.

The present invention was made based on these findings,
An example will be described below.

Example of Invention

A fade meter FAL-3 type manufactured by Suga Test Instruments Co., Ltd. was used for the fading test in the examples, and the condition was a temperature of 63 ± 2.
C., relative humidity 50%, 100 hours. This accelerated test corresponds to about one year in normal use.

The fading property was evaluated using the color difference ΔE ^* ab according to the L ^* a ^* b ^* color system (CIE1976).

ΔE ^* ab represents the color difference before and after the fading test and is given by the following equation.

ΔE ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δ
b ^* ) ² ] ^1/2 Here, ΔL ^* , Δa ^*, and Δb ^* represent changes in lightness, saturation, and hue, respectively.

It is known as an empirical rule that if the color difference ΔE ^* ab before and after the fading test is 9.0 or less, the change cannot be recognized by human eyes. Therefore, this value was used as a standard for fading. Shimadzu spectrophotometer MP as a color measuring device
S-2000 type was used.

Example 1 A polyurethane resin having a thickness of about 18 μm was applied to the surface of a flat plate cured with a bisphenol A type epoxy resin and an amine curing agent, and then a disperse dye (Diani) was used.
x ACE-Trio, red, yellow, blue) and subjected to a color fading test to obtain a color difference ΔE ^* ab, 9.3 for red, 3.1 for yellow, and 15. for blue.
It was 6.

(Example 2) A polyurethane resin mixed with 1% of an ultraviolet absorber (Sumisorb 350) was applied on the surface of the same epoxy resin plate as in Example 1 to a thickness of about 18 μm, and the same dye as in Example 1 was applied. The color difference ΔE ^* ab was determined by dyeing with a dye and subjecting it to a fading test. As a result, it was 7.0 for red, 2.4 for yellow, and 9.8 for blue.

Comparative Example 1 When the same epoxy resin plate as in Example 1 was dyed with the same dye as in Example 1 without applying a polyurethane resin, the color difference ΔE ^* ab was 33.4 in the case of red, and yellow. Was 11.0 and blue was 30.7.

As is clear from the above results, the large color change observed when the epoxy resin is directly dyed is substantially negligibly improved by coating the polyurethane resin and dyeing it to form the dyed layer. It

Further, it is recognized that the color change is further improved by including the ultraviolet absorber in the polyurethane resin.

〔The invention's effect〕

According to the present invention, since the fading resistance of the dyed epoxy resin product is significantly improved, it is possible to provide a spectacle frame which is excellent in durability and rich in color.

Claims (2)

[Claims] 1. A plastic spectacle frame, at least a main part of which is composed of a base made of epoxy resin and a dyeing layer made of polyurethane resin coated on the base and dyed with a dye. 2. At least a main part is constituted by a base made of an epoxy resin and a dyeing layer made of a polyurethane resin coated on the base and dyed with a dye and containing an ultraviolet absorber. Plastic eyeglass frames to be used.