JPS593595B2 - Dyeing method for plastic molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for dyeing wearable ornaments such as brooches, buttons, bangles, earrings, etc. made from cellulose ester plastic materials.

In recent years, with the diversification of fashion, there has been a strong tendency for accessories to be diversified, and in particular, ornaments with beautiful colors and transparency are desired.

Therefore, the inventors of the present invention investigated the purpose of developing a plastic molded product that feels good when worn, and found that the use of cellulose ester plastic, particularly cellulose ester, and the use of disperse dyes as dyeing conditions. We have developed a plastic molded product that can satisfy the above requirements by using a specific dyeing method using scales, and have completed the present invention.

The gist of the present invention is that a plastic molded product made by molding cellulose ester plastic is mixed with a mixed solvent of a specific organic solvent and water at a ratio of 1/9 to 515. In a dye bath containing water-soluble inorganic salts and disperse dyes in a proportion of 50 g/l, the bath temperature was 100 g/l.
A dyeing method for plastic molded products characterized by dyeing at temperatures below ℃.

Specific examples of cellulose ester plastics used in carrying out the present invention include cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, and cellulose propionate. Specific examples include earrings, brooches, buttons, necklaces, eyeglass frames, lenses, bracelets, clips, and other ornaments.

Molded products made of cellulose ester plastics used in the present invention have particularly excellent transparency, and when dyed, they are beautifully dyed, and even when these plastic molded products are attached to the body, they do not feel strange. It has extremely excellent performance as a decorative item.

The dye medium for dyeing the above-mentioned plastic molded products may be a mixture with an organic solvent that is a swelling solvent for cellulose ester plastic molded products and has a certain degree of solubility in water. In the present invention, it is necessary to use a mixed solvent in which an organic solvent having the following general formula and water are mixed in a ratio of 1=9 to 5:5.

general formula [In the formula, R1-R5 are CH3COO-, C2H,0-.

A group consisting of CH30- and OH-, which may be the same or different.

] Specific examples of the organic solvent represented by the above general formula are:
Examples include cellosolve, methyl cellosolve, ethyl cellosolve, triacetin, ethylene glycol, propylene glycol, glycerin, etc., and these can be used alone or in combination, and these organic solvents are added to water in the above ratio. It is preferable that it is homogeneous.

Therefore, it may be preferable to use a water-injectable solvent other than those represented by the above general formula in combination, if necessary.

When a dye bath made of a uniform solvent is used, cellulose ester plastic molded products, especially 0.5 urn.
This is preferable because the plastic molded product having the wall thickness above can be dyed in a deep color without causing devitrification or uneven dyeing due to dyeing.

For this purpose, mixtures of solvents represented by the general formulas [1] and (II), especially in the weight ratio [■]/[■]
It is preferable to use a mixed solvent having a ratio of 5/95 to 9515.

The mixing ratio of the above organic solvent and water is 1:9 to 5:5.
When using a mixed solvent with a ratio higher than 515, the dyeing temperature of the plastic molded product must be raised and the dyed plastic molded product must be dyed in a dark color unless it is dyed for a considerable period of time. Since it is not possible to obtain molded products, the plastic molded products that have been shaped are susceptible to deformation.Furthermore, plastic molded products made from cellulose ester tend to devitrify during the dyeing process, resulting in poor aesthetic appearance. This method is not preferred as a dyeing method for plastic molded articles used as decorative articles, especially those having a wall thickness of 0.5 mm or more.

Specific examples of water-soluble inorganic salts used in carrying out the present invention include sodium chloride, potassium chloride, calcium chloride, sodium sulfate, and sodium nitrate.

When adding these water-soluble inorganic salts to the dyeing medium,
It has become possible to increase the penetration rate of dyes into plastic molded products, making it possible to dye plastic molded products in deep colors in a short time at low temperatures, and also to reduce devitrification caused by dyeing of plastic molded products. By being able to prevent this phenomenon, it is possible to make dyed plastic molded products with extremely good aesthetics. Among these inorganic salts, neutral inorganic salts in particular exhibit the above-mentioned effects significantly. preferable.

The amount of these water-soluble salts used is 5 to 50 g per dye bath.
11 is preferably used in the range of 8 to 30 g/l; if this concentration is less than 5 g/l, the above-mentioned preferred dyeing conditions will be reduced, which is not preferred.

Moreover, if it exceeds 50 g/1, the solubility of the dye deteriorates, the dye usage efficiency decreases, and spot-like uneven dyeing may occur on the dyed product, which is not preferable.

In addition, the dyes used in carrying out the present invention include:
Although various dyes can be used, it is preferable to use disperse dyes in consideration of dyeing speed, weather resistance of the dyed product, etc., such as diaminoazobenzene dyes, NN-bishydroxyethylaniline dyes, dinitrohydroxyphenylaniline dyes, etc. dyes, hydroxyethylaminoanthraquinone dyes, etc. Commercially available dyes include, for example, Diamond Sprue F B-8E (Dia
nixBlue FB-8E), Dianic Sprue R-N E (Dianix Blue R-N
E), Diamond Red R-E (Diani
x Red RE ) (manufactured by Mitsubishi Chemical Industries, Ltd.), etc.

The dyeing temperature when carrying out the present invention is 100°C.
Hereinafter, the temperature is preferably 30 to 80°C.

Cellulose ester plastic molded products, especially those with a wall thickness of 0
．． Fibers with a diameter of 5 mm or less are deformed by heat during dyeing, and there is no major problem even if a slight devitrification phenomenon occurs, so dyes containing water with a ratio of 90% or more in which the dye can be easily dissolved are used as the dye medium. No major problem occurs even if dyeing is carried out for a long time at a temperature of 100°C or higher to increase the dyeing efficiency.
The cellulose ester plastic molded products on anJJ are
Since it is often used in fields with decorative purposes, it is undesirable for the plastic molded product to undergo devitrification, uneven dyeing, and thermal deformation of the plastic molded product during dyeing.

Therefore, the conditions for dyeing cellulose ester plastic molded products with a wall thickness of 0.5 mm or more are below the heat deformation temperature of the cellulose ester plastic, especially at 100°C.
It is necessary to select the following dyeing temperature, but according to the method of the present invention, dyeing can be carried out in a very short time, for example within 10 minutes, without causing devitrification of the plastic molded product. be.

According to the method of the present invention, a plastic molded product with a wall thickness of 0.5 mm or more made of cellulose ester plastic,
In particular, it is possible to easily dye decorative items even at a store selling decorative items, and one of the major features is that it is possible to easily make decorative items with a color tone that meets the customer's request.

The present invention will be explained below with reference to Examples.

Example 1 A cellulose butyl acetate plate with a thickness of 5 mm was dyed under the conditions shown in Table 1.

Table = 1 B Triacetin 20g/l 20g/l Methyl Cellosolve 200g/132009/ID1an
ix Blue FB-8E 1 g/ 11 g/
l (manufactured by Mitsubishi Chemical Industries, Ltd.) N a 2 S 04 t 5j! /l-
L, R, 1:2001:200 A B Staining temperature 50°C50°C Staining time
5 minutes Note: The entire dye bath was made up to 11 with water.

When we observed the washed and dried plastic plates dyed under conditions A and B shown in Table 1, we found that the plastic plates dyed under condition A had no devitrification phenomenon and were uniformly medium-colored. The plastic plate was dyed blue, but when it was dyed under condition B, which did not contain Na2S04 in the dye bath, the surface of the plastic plate had a devitrification phenomenon and was only dyed in a light color. Ta.

Also, instead of Na2S04, use Na(J'15g/7
Alternatively, when CaCl2129/l was added and stained, similar results to A were obtained.

Example 2 Made of cellulose triacetate, width 5u square, length 10C
The prisms of rrL were stained under the conditions shown in Table 2.

Table-2 Methyl cellosolve 450 g/1jDi
anix Blue RN-E 4g
/ l (manufactured by Mitsubishi Chemical Industries, Ltd.) N a 2 S 04 45 g /
(IL, Rol: 200 Dyeing temperature 60℃ Dyeing time
The 3-minute dye bath was adjusted to 11 with water.

The plastic prisms dyed under the conditions shown in Table 2 were washed with water and then dried and observed. As a result, the prisms were uniformly dyed in a deep color without causing any devitrification phenomenon.

Example 3 A cellulose diacetate brooch with a wall thickness of 5 mm was coated with triacetin 50 j! /l, glycerin 300g/1%Na
2SO410g/L Dianix Red R-8
The brooch was dyed at a concentration of F, 49/l using a dye bath adjusted to 11 with water, Rol: 200, dyeing temperature of 50'C, dyeing time of 5 minutes, washed with water, and dried. It was confirmed that the dyeing was uniform without causing any see-through phenomenon.

Furthermore, when eyeglass frames and bracelets made of cellulose acetate butyrate were dyed under the same conditions as above, it was confirmed that dyed products with a rich aesthetic appearance were obtained.

Claims (1)

[Claims] 1. A cellulose ester plastic molded product is prepared by mixing an organic solvent having the following general formula with water in a ratio of organic solvent:water 1:9 to 5:
Dyeing is carried out at a bath temperature of 100°C or less in a dye bath in which a water-soluble inorganic salt and a disperse dye are added in a proportion of 5 to 50 g/l to a mixed solvent in a proportion of 5 to 5. General formula for dyeing plastic molded products [In the formula, R1-R5 are CH3COO-, C2H, 0-C
A group selected from H30- and OH-, which may be the same or different. 2. A method for dyeing plastic molded products, which is characterized in that the method according to claim 1 uses a dye bath containing an externally soluble inorganic salt at a concentration of 8 to 30 fl/l. 3. Claim 1, characterized in that in the method described in claim 1 or 2, a cellulose ester plastic molded product having a wall thickness of Q, 5 mm or more is used as the plastic molded product. , or the method for dyeing plastic molded products according to item 2.