JPS6058720B2 - Printing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for printing an arbitrary pattern on an uneven object having a curved surface, grooves, or protrusions on its surface.

Conventionally, a method of printing a pattern on the surface of an object with unevenness is to print the pattern on a thin film, float the thin film on a liquid with the printed side facing up, and then press the object from above. A method is known in which the pattern is transferred to the surface of an object using the hydraulic pressure of a liquid, and then the thin film is removed from the surface of the object.

However, for this method, it is desirable for the thin film to have good swelling properties, i.e., expandability, like Obrado, and to have high flexibility and softening properties. Since the film is required to adhere tightly to the uneven surface while being able to stretch and expand, when a thin film with such characteristics is floated on the surface of water, the pattern printed on it will be significantly enlarged and deformed before it is transferred. It is not possible to transfer the exact pattern printed onto the surface of the object. Since the thin film prevents the printing pattern from being transferred to the finely uneven surface of the object, printing on complex unevenness is virtually impossible. After the printed pattern is transferred, the thin film must be removed by physical or chemical means, which increases the number of steps. There were other drawbacks. The present invention aims to eliminate the above-mentioned drawbacks and provide a method for easily printing an arbitrary pattern on the surface of an uneven object having an arbitrary shape.
The present invention will be explained in detail below with reference to the drawings. As shown in FIG. 1, the printing sheet for transfer used in the present invention is composed of a base sheet 1, a thin layer 2 made of water-soluble resin, a pattern layer 3, and a heat-sensitive adhesive layer 4. That is, one side of the base sheet is coated with a gravure coater, a roll coater,
A thin layer of water-soluble resin is applied using a knife coater or other conventional coating method. This thin layer is formed so thin that it dissolves quickly when immersed in water and is completely removed from the pattern layer. Next, an arbitrary pattern layer is applied thereon using a gravure printing method, an offset page printing method, or other conventionally known printing method.

The paint or printing ink used at this time can be arbitrarily selected as long as it is insoluble in water. Next, a heat-sensitive adhesive is applied onto the pattern layer using a gravure coater, a roll coater, a knife coater, or any other conventionally known coating method.

The printed sheet constructed as described above is floated on the surface of water 5 with its printed side facing upward as shown in FIG. 2 below.
Then, the thin layer made of water-soluble resin is dissolved by immersion in water, and the base sheet is peeled off from the pattern layer and submerged in water. Next, as shown in FIG. 3, when the object 7 held by the object holding mechanism 6 is pressed against the pattern layer floating on the water surface and part or all of it sinks into the water, the pattern layer is affected by water pressure. Therefore, it adheres closely to the surface of the object.

The temperature of the water at this time is kept below the activation temperature of the heat-sensitive adhesive. If the water temperature is above the activation temperature,
It is important to control the water temperature at this point because the part of the pattern layer that comes into contact with the object will adhere to the object and will not be able to move freely, making it impossible to print on the minute irregularities on the surface of the object. Next, as shown in Figure 4, after the pattern layer has completely adhered to the surface of the object, water is heated or mixed with preheated water so that the water temperature is higher than the activation temperature of the heat-sensitive adhesive. Perform operations such as replacing the water with preheated water.

The various operations described above may be performed after the pattern layer has completely adhered to the object surface, or after the pattern layer has completely adhered to the object surface, the water temperature may be higher than the activation temperature of the heat-sensitive adhesive. If it is adjusted so that As described above, the heat-sensitive adhesive is activated. By transferring and adhering the pattern layer to the surface of an object and then lifting the object out of the water, it is possible to print any pattern on the surface of the object having an uneven shape. Next, each component of the present invention will be explained.

The base sheet can be anything that can be printed. Polyethylene sheet, polypropylene sheet, vinyl chloride sheet, polyester sheet, nylon sheet,
Others can be used.

Thin layers made of water-soluble resins can be made of synthetic polymers such as sodium polyacrylate, polyvinyl alcohol, methylcellulose, carboxymethylcellulose, polyethylene oxide, polyvinylpyrrolidone, acrylamide, etc., and animal polymers such as glue. , gelatin, chirotin, polypeptide, etc., vegetable polymers include starch, cellulose, dextrin, albumin, soybean protein, gum arabic, gum tragacanth, etc., and seaweed polymers include funori, agar, Select from among sodium alginate, etc., taking into consideration coater suitability, speed of dissolution with water, etc. Any paint or printing ink can be used as long as it is insoluble in water.

The pattern layer includes letters, symbols, wood grain patterns, abstract patterns/patterns,
You can arbitrarily select from various patterns such as marble pattern.

Heat-sensitive adhesives include amino adhesives such as urea and melamine,
30 to 40 from phenolic adhesives, epoxy adhesives, urethane adhesives, polyester adhesives, acrylic adhesives, and composite adhesives that are a mixture of them.
'C or below, no tackiness or adhesion is exhibited,
Select a material that is activated at a temperature of 30 to 40°C or higher and exhibits tackiness or adhesion.

The objects are mainly three-dimensional objects with uneven surfaces, such as wood, metal, plastic, and other molded objects, but are of course not limited to these, and are composed only of smooth surfaces. It also includes three-dimensional objects or flat plates.

The object holding mechanism is configured to allow all or part of the object to sink into the water, and after settling, pull it up to recover the object, and then replace the holding object with a new object. It is only necessary that the surface of the object to be applied sinks into the water.

According to the method of the present invention as described above, the following effects can be obtained. Since the printed pattern is transferred, not only multicolor patterns but also photographic patterns can be applied to the surface of the transfer object, and the same pattern can be applied to a large number of transfer objects.

Since the base sheet is already separated when the transfer target is pressed, the patterns do not overlap even if the surface is highly uneven. The base sheet does not dissolve in water, but separates from the pattern on the water surface and sinks to the bottom of the aquarium, so the time required for transfer is short, and the water is only slightly contaminated, so the pot life of the water is very long. long.

Since the pattern layer is adhered to the surface of the object with an adhesive, the pattern does not fall off.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing an example of a printed sheet used in the present invention, Figure 2 shows the printed sheet floating on the water surface with the base sheet separated, and Figure 3 shows an object pressed against the pattern layer on the water surface. FIG. 4 is a schematic illustration of a state in which the pattern layer is completely adhered to the object surface and the water temperature is raised. DESCRIPTION OF SYMBOLS 1... Base sheet, 2... Thin layer made of water-soluble resin, 3... Pattern layer, 4...
Heat-sensitive adhesive layer, 5...Water, 6...Object holding mechanism, 7...Object.

Claims (1)

[Claims] 1 A thin layer made of water-soluble resin is provided on one side of a base sheet, a desired pattern layer is applied on top of that using paint or printing ink, and a layer of heat-sensitive adhesive is further provided on top of that. Float the printing sheet with the pattern layer facing up on a water surface at a temperature that does not activate the heat-sensitive adhesive, and the thin layer consisting of the water-soluble resin completely dissolves in the water and the base sheet separates from the pattern layer. The object is pressed from above the pattern layer that remains on the water surface after peeling, causing part or all of it to settle into the water, and after the pattern layer is brought into close contact with the object surface by the water pressure, the temperature of the water is determined. A printing method characterized in that the pattern is transferred and adhered to the surface of an object by keeping the temperature at a temperature higher than the activation temperature of the heat-sensitive adhesive.