JPH0615743B2 - Gold colored image forming method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for forming a strongly bonded gold colored image on a surface made of a specific material, which is a product of silk or modified silk, or gelatin. It can be used to form gold patterns and letters on the coated solid surface.

2. Description of the Related Art Gold is one kind of precious metal and has been widely used for decoration of various high-class products since ancient times. In particular, since fine particles of gold have a strong coloring power, fine particles obtained by reducing a gold salt with a stannous salt are called "casium purple" and are used for coloring ceramics and glass.

Further, a method of coloring fibers with fine gold particles is also known, and the present inventors have previously used gold hydrosol in which gold fine particles are uniformly dispersed in water to change the color of silk cloth to a purple color. A method for dyeing has been proposed (JP-A-62-299587).

However, such a coloring method using fine gold particles results in remarkable aggregation of gold particles when the amount of adsorption is increased, resulting in a dull blackish tone, or fine particles being colored only in the state where they are attached only to the surface portion. Therefore, it has a drawback that it is easily removed by friction, especially in a wet state, and it requires a manual operation by a skilled person to form a specific pattern, which is unsuitable for industrial production. there were.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention provides a gold-colored image that does not discolor even when a large amount of gold is attached, firmly adheres to the surface of a predetermined material, and does not fall off due to friction, Can be easily formed without
It is made for the purpose of providing a method that can be industrially carried out.

Means for Solving the Problems As a result of intensive studies to develop a method for forming a colored image of gold by a simple means, the present inventors have found that a gold salt adhesion layer is formed on a surface made of a specific material. It was found that the object can be achieved by forming it, irradiating it with light through a transparent substrate carrying a desired image, and then removing the unexposed portion, and completed the present invention.

That is, the present invention forms an adhesion layer of a water-soluble metal on a surface made of a material selected from silk, gelatin and cationized cellulose, and then irradiates it with light through an image carrier to expose the exposed portion. The present invention provides a method for forming a gold-colored image, which comprises developing the color and then removing the unexposed portion.

In the present invention, it is necessary to use, as the surface on which the gold colored image is formed, a surface made of a material that adsorbs a gold salt well when it comes into contact with a solution of a water-soluble gold salt. Such materials can include silk, gelatin or cationized cellulose. The silk or cellulose in this may be in any shape such as fiber, cloth or thread. The gelatin may be not only the sheet or film but also a coating film formed on the surface of a suitable solid material.

Examples of the water-soluble gold salt used in the present invention include ammonium chloroaurate, sodium chloroaurate, potassium tetracyanoaurate, and the like.

These gold salts are used as an aqueous solution with a concentration of 1 to 100 mmol /.

To form an adhesion layer of gold salt on the surface of the material, the above material is dipped in an aqueous solution of gold salt, and is left as it is or after being washed with water and dried. The immersion temperature at this time is selected in the range of 0 to 100 ° C., but usually room temperature is used. The dipping time is selected within the range of 10 seconds to 10 hours, but about 10 minutes is usually sufficient.

In this dipping treatment, the higher the gold salt concentration in the aqueous solution, the longer the dipping time, and the higher the dipping temperature, the greater the amount of gold salt adhering to the surface of the material.
The color tone after light irradiation becomes dark.

After soaking in this gold salt solution, leave it in water for a longer time, or soak it in an aqueous solution of a weak alkali such as sodium carbonate or ammonia, and then wash with water.
Drying enhances sensitivity to light and accelerates coloring. This tendency is particularly remarkable when silk is used as the material.

The gold salt adhesion layer thus formed on the surface is then irradiated with light through a transparent substrate carrying the desired image. As this light source, a fluorescent lamp, a tungsten lamp, a mercury lamp, a xenon lamp, sunlight or the like can be used. The irradiation time varies depending on the intensity of light and is usually in the range of 5 minutes to 1 month.

By this irradiation of light, fine gold particles are deposited on the exposed portion, so if the unexposed portion is removed, an ultraviolet gold colored image can be obtained. A photographic fixing solution is convenient for removing the unexposed portion, but a solvent capable of dissolving the water-soluble gold salt other than the photographic fixing solution can also be used.

In order to form the fine gold particles in the method of the present invention, it is necessary to irradiate light with light in the presence of a small amount of water, but the amount of water supplied from ordinary air is sufficient.

However, in an absolutely dry state such as in a desiccator in which a desiccant such as silica gel or calcium chloride coexists, the solid surface to which the gold salt has been applied does not develop color even when exposed to light. The solid substance provided with can be stored for a long period of time without being colored in a bright place. The solid substance thus stored can be colored at any time by being taken out into the air and irradiated with light.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples.

Example 1 A 4 cm × 4 cm plain weave silk cloth with 14 arms (Japanese Standards Association, attached white cloth for dyeing fastness test) was soaked at room temperature for 20 minutes in a 20 mmol / aqueous chloroauric acid aqueous solution, and then washed with water, and then, It was immersed in a 5% aqueous solution of sodium carbonate for 10 minutes, washed with water and dried. When the light orange silk cloth thus obtained was irradiated with sunlight through the image bearing glass for 10 days, a silk cloth having a dark reddish purple colored image was obtained.

Example 2 A 4 cm × 4 cm cotton cloth (Japanese Standards Association, attached white cloth for dyeing fastness test) was cationized with 3-chloro-2-hydroxypropyltrimethylammonium chloride and sodium hydroxide (processing technique, Volume 22 Issue 3 175
Page)), this cotton cloth at room temperature at 20 mmol /
Soak for 10 minutes in an aqueous solution of sodium chloroaurate,
Washed with water. Next, it was dipped in a 5% aqueous ammonia solution for 10 minutes, washed with water and dried. The light yellow silk cloth thus obtained was irradiated with sunlight through the image bearing glass for 10 days, whereby a cotton cloth having a black-grey gold colored image was obtained.

Example 3 A silk cloth similar to that used in Example 1 was used at room temperature at 20 mmol /
Was dipped in the aqueous sodium chloroaurate solution for 10 minutes, then pulled up, washed quickly with water and dried to obtain a pale orange silk cloth. Stick a piece of paper in the shape of a pattern on the surface of this silk cloth,
A 0 W high pressure mercury lamp was irradiated for 1 hour from a distance of 5 cm. Next, after peeling off the piece of paper, it was dipped in a fixing solution for photography (Fuji Photo Film Co., Ltd., Fujifix) for about 10 minutes to dissolve the gold salt in the unexposed portion, washed with water and dried, A silk cloth was obtained in which only the part where the paper piece had been hit was white and the remaining part was colored dark purple.

Example 4 4 cm × 4 cm photographic printing paper (Fuji Photo Film Co., Ltd., Fujibro WP) was unexposed and soaked in a photographic fixing solution (Fujifix) for about 10 minutes without development to remove silver bromide. After that, only the gelatin layer was formed, washed with water and dried. This photographic paper was immersed in a 20 mmol / sodium chloroaurate aqueous solution for 10 minutes at room temperature, then quickly washed with water and dried. The light-yellow photographic printing paper thus obtained was covered with a monochrome negative film, which was then exposed to direct sunlight for 1 hour in fine weather, and then about 10 in a photographic fixing solution (Fujifix).
It was dipped for a minute to dissolve the gold salt in the unexposed portion, washed with water and dried to obtain a photographic paper having a purple positive image.

Effects of the Invention All the gold-colored images obtained by the method of the present invention have a beautiful purple image, and this color does not discolor or fade even if left in a bright place for a long period of time. Moreover, since this colored image can be formed by a simple operation of simply irradiating light through the image carrier, no special skill is required and mass production is easy.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-133076 (JP, A) JP 63-192874 (JP, A) JP 63-192875 (JP, A) JP 49- 30038 (JP, A) JP-B-43-14082 (JP, B1)

Claims (2)

[Claims] 1. An adhesion layer of a water-soluble gold salt is formed on a surface made of a material selected from silk, gelatin and cationized cellulose, and then exposed to light through an image carrier to expose the exposed portion. A method for forming a gold-colored image, which comprises developing a color and then removing an unexposed portion. 2. The method for forming a gold colored image according to claim 1, wherein a weak alkaline treatment is carried out after forming an adhesion layer of a water-soluble gold salt.