JPS6139911B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for performing raised printing on a substrate, and more particularly, to a printing method for prominently raising an arbitrary pattern without applying pressure to the printing substrate. Conventionally, various methods have been used to perform raised printing, but each method has advantages and disadvantages. For example, the most common method is to use screen printing to print a stiff, relatively less sticky ink on the surface of a substrate. This method uses a solvent-free two-component epoxy resin ink with a high solids content as much as possible, and uses a special screen plate with a thick film thickness. The problem is that the thicker the film, the worse the ink permeability and the lower the printing workability. In addition, in screen printing, the thickness of the ink film is determined by the film thickness of the screen plate, but it is generally very difficult to control the film thickness of the screen plate in a thick state. Another problem is that it is difficult to control the thickness of the ink film because the reproducibility of the thickness is poor. Another problem is that thick-film screen plates usually have a thick coating of light-sensitive emulsion on the surface of a thin screen gauze.
The desired image is printed and developed, but in the case of a pattern with a large area of the image area, even if the desired ink film thickness is obtained in the surrounding area of the image area, Since the tip of the squeegee is deformed by the pressure of the squeegee in the central portion, ink is applied only to the thickness of the screen gauze, resulting in an uneven ink film thickness. On the other hand, another way of thinking is to use a foaming ink, perform the screen printing itself using a screen plate with a normal stable film thickness, and then foam the ink to create a bulge after printing. There is. According to this method, there are no problems with printing workability or reproducibility, but since the ink film is foamed, the strength of the ink film is inevitably weakened, and therefore the products that can be obtained with this method are very limited. The disadvantage is that it can only be used for certain purposes. On the other hand, as a build-up printing method using powder, thermoplastic resin powder is sprinkled over the entire surface of the printing material after printing on the printing material by offset printing or screen printing with adhesive or multi-adhesive ink. There is also a method in which the resin powder is applied to only the ink or adhesive area on the printing material, and then heated to a temperature at which the powder melts to melt the powder, thereby raising the printed area. There is. However, this method has the disadvantage that only a certain amount of resin powder adheres to the surface of the adhesive or ink, and therefore sufficient heaping cannot be achieved. Furthermore, there is a conventional method called electrostatic screen printing, which combines a screen plate and powder. This is done by applying a voltage between a conductive screen plate and a counter electrode, causing toner charged with the same sign as the screen plate to adhere to a printing medium placed between the screen plate and the counter electrode, and then producing a powder image. However, the main focus of this method is to print without contacting the printing material, and the purpose and method are different from raised printing according to the method of the present invention. It is something. As a result of repeated studies to improve the shortcomings of the various methods described above, the inventor of the present invention has developed a method in which powder particles that are melted by heating are dropped onto a printing substrate through the openings of a screen plate, and deposited on the printing substrate. They focused on the fact that by doing so, it was possible to stably perform thick film build-up printing that could not be achieved with conventional methods, and completed the present invention. Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is an explanatory diagram for explaining the present invention which is carried out using a general flat screen plate. First, a flat screen plate 2 having a desired opening 3 is held horizontally above a printing substrate 1 that is placed horizontally, with a constant gap maintained therebetween. Printing base material 1
is not particularly limited, and any material can be used as long as it can withstand the melting temperature of the powder 5. Examples include paper, paperboard, metal plates, asbestos sheets, plastic films,
In addition to plywood, wood fiberboard, inorganic fiberboard, etc., this method does not apply pressure to the printing substrate 1, so it can be used to print on materials with soft surfaces or sticky surfaces that cannot be printed at all with normal printing methods. Even if the material has properties such as an uncured Blastisol coated sheet or a coated sheet whose coating film has not been dried to the touch,
It can be used as a printing base material 1. Next, flat screen version 2 will be explained. As the screen plate 2 used in the method of the present invention, a normal screen plate can be used, but a screen with an appropriate opening selected according to the particle size of the powder or granular material 5 to be used is pasted on the frame, and a manual or photographic method is used. In general, it is desirable to select a screen that closes off the parts of the screen other than the image. in this case,
The height of the bulge is determined by the gap between the screen plate 2 and the printing substrate 1, and has nothing to do with the thickness of the screen plate 2. On the contrary, a printing screen with a thin wire diameter, thin wire, and a wide opening gives favorable results. When using 100 mesh powder 5, a screen of 30 to 70 mesh is preferable, for example, 70 mesh,
A screen with a wire diameter of about 80μ is preferable in terms of cost and workability. However, considering that almost the same finish can be obtained even with a screen of 60 mesh and a wire diameter of about 150μ by adjusting the printing speed, the present invention has another advantage in that it has a very wide selection of screen materials. It turns out that I also have one. The material of the screen may be nylon, polyester, stainless steel, etc., and the thread may be monofilament or multifilament. Regarding the film thickness of the screen plate 2, as already mentioned, in the present invention, the height of the bulge is unrelated to the film thickness of the screen plate 2, so that the screen plate 2 can be manufactured manually or photographically. The minimum necessary film thickness is sufficient. It was found that the number of screen lines affects printing workability, and that this also has a correlation with the particle size of the powder. Show this-
Shown in 1.

[Table] It varies depending on the properties of the powder used, but in general, if the particle size is not too fine, screen penetration is poor, and if it is coarse, the edges of the image are likely to be disturbed.
In addition, it is necessarily impossible to use a material whose opening is rougher than that of the screen gauze. Next, regarding the powder 5, the powder 5 used in the present invention includes a thermoplastic resin composition powder that melts when heated, and a thermosetting resin that hardens after being melted by heating. Composition powder is used as a substrate. Examples of the former resin include polyethylene resin, polypropylene resin, polyamide resin, vinyl chloride resin, vinylidene chloride resin, and vinyl acetate resin, while examples of the latter resin include thermosetting acrylic resin, epoxy resin, and polyester resin. , phenolic resins, amino resins, thermosetting fluorocarbon resins, etc. If necessary, pigments, fillers, stabilizers, plasticizers, surfactants, etc. may be mixed with these base resins, and the mixture may be pulverized to form the powder 5. Good results can also be obtained by using known powder paints as powder particles. Next, let's talk about printing. The printing method is similar to the normal screen printing method, but the basic difference is that no printing pressure is applied to the printing material, and a constant gap is left between the bottom surface of the screen plate and the surface of the printing material. The point is to maintain the To explain step by step, first, the printing base material 1 is placed horizontally, and the screen plate 2 is held horizontally above it with a constant gap maintained therebetween. The reason why the printing substrate 1 and the screen plate 2 are held horizontally is that horizontality is most preferable in terms of uniform raised height and improving image reproducibility. Next, a slightly excessive amount of powder 5 is supplied to one end of the screen plate 2, and then the powder 5 is moved to the other end while scratching the surface of the screen plate 2 with a plate-shaped spatula 4. In the area where the image line on 1 is planned to be formed, the powder 5 is in the opening 3 of the screen plate.
The particles fall from the substrate and are deposited on the printing substrate 5. At this time,
By setting the moving height of the plate-shaped spatula 4 so that an appropriate gap is formed between the upper surface of the printing substrate 2 and the lower surface of the screen plate 2, the powder and granules are moved to a height corresponding to this gap. It is possible to control the amount of 5. There are no restrictions on the material and shape of the plate-shaped spatula 4, such as metal plate, synthetic resin plate, wood, etc., as long as the tip is straight. Even a rubber squeegee used for ordinary screen printing can be used. Also, as a method particularly suitable for the present invention, a fourth plate-shaped spatula 4 may be used instead of the plate-shaped spatula 4.
Using a cylindrical box 23 that is hollow inside and has a discharge port 25 for the granular material 24 on one side as shown in the figure, the granular material 24 is supplied from the inside of the box 23 onto the screen plate 21. Then, the powder and granular material 24 can be smoothly supplied during continuous operation. The use of the box body 23 is particularly effective in the case of a handle in which there is a large difference in the amount of powder consumed in the width direction of the handle. Next, the printed substrate 1, which has been printed, is held horizontally and guided to a heating device, where it is heated to the melting temperature of the granular material 5, and the granular material 5 is melted. In addition, in the case of powder or granular material based on a thermosetting resin composition,
Further, necessary heating is performed to complete the curing reaction. As a heating method, a known method can be used, but it is inappropriate to open hot air such that strong hot air hits the surface of the base material and the powder particles 5 are scattered. Appropriate. Next, by cooling the printing substrate 1 and cooling the melted or melted and solidified powder 5, a raised portion 27 in an arbitrary pattern was formed on the printing substrate 26 as shown in FIG. Products (enhanced prints)
is obtained. The method using the flat screen plate 2 has been described above, which is a feature of the present invention. Provide an appropriate gap between the printing base material and the screen plate,
Based on the idea of depositing the powder at a height corresponding to this gap, the screen plate does not necessarily have to be flat, and even if it is a rotary screen plate as shown in Fig. Similar results can be obtained even with a strip-shaped endless screen plate 12 as shown in the figure. These methods will be explained according to the drawings. In FIG. 2, a plate-shaped spatula 9 is fixed inside the rotating rotary screen plate 7 so that its tip lightly contacts the inner surface of the plate. 10
is dropped onto the printing base material 6. If an appropriate gap is provided between the printing base material 6 moving at a speed equal to the circumferential speed of the rotary screen plate 7, the powder 10
is deposited on the printing substrate 6 through the opening 8 of the rotary screen plate 7, and the powder 10 rises to a height corresponding to the gap. According to this method, printing can be performed continuously on the web-shaped printing base material 6. Next, referring to FIG. 3, first, the belt-shaped endless screen plate 12 adjusted into a belt-shape is stretched through pulleys 16 to 18.
The rotating outer periphery is set parallel to the printing substrate 11. The way the strip-shaped endless screen plate 12 is stretched is not limited to the triangular shape shown in the figure, but can be stretched in any shape. A plate-shaped spatula 14 is fixed inside a strip-shaped endless screen plate 12 so that its tip lightly touches the inner surface of the plate. Powder 15 is supplied to the front side of the spatula 14, and the belt-shaped endless screen plate is rotated. The printing substrate 11 is moved at the same speed as the endless screen plate 12, and by providing an appropriate gap between the endless screen plate 12 and the printing substrate 11, powder falling from the opening 13 can be removed. Granules 15 are deposited on the printing substrate 11 at a height corresponding to the gap. According to this method, not only can continuous raised printing be performed on the web-like printing substrate, but also the printing pattern can be repeated and the length can be made to any desired length, making it possible to print large patterns that cannot be obtained with normal printing methods. It is also possible to print The band-shaped plates used in this method do not need to be very precise in the endless splicing, and even if the spliced parts have some uneven thickness or steps, it will hardly affect the finish. This is because, as a feature of the present invention, strong printing pressure is not applied to the surface of the plate as in normal screen printing, and the surface of the plate does not come into contact with the printing material. It becomes very convenient,
An additional effect is that a cheaper version can be used. Furthermore, since no force is applied to the plate, there is almost no damage to the plate, and the plate can be used almost permanently. When carrying out the method of the present invention, depending on the nature of the powder, a small amount of powder may remain attached to the openings of the screen plate immediately after printing, which may cause the surface of the printing substrate to remain unimaged. This powder may fall onto areas that should be lined parts and cause stains, and in such cases, when the screen plate is a certain distance away from the printing substrate, the powder particles that have adhered to the screen plate will disappear. When the body is removed by suction using a suction device 19 shown in FIG. 3 under reduced pressure, clear printing can be achieved. Next, the method of the present invention will be further explained based on Examples. Example 1 A cold-rolled steel plate with a thickness of 0.5 mm and a base coat was placed horizontally on a surface plate, and a wire diameter of 150 microns was placed on top of this.
A flat screen plate made of 60 mesh polyester monofilament gauze was set horizontally at a distance of 6 mm. A thermosetting polyester resin powder coating was applied to the top of the screen plate and scraped with a metal blade to move the powder coating from one end of the plate to the other. At this time, the metal blade was set at a height such that a gap of 4 mm was created between the steel plate and the lower surface of the screen plate, and was moved horizontally. The powder paint fell onto the steel plate through the opening of the screen plate and was deposited to a height of 4 mm. Next, the steel plate
The deposited powder coating was heated for 10 minutes in an open hot air at 180°C to melt and harden, and then cooled to obtain a decorative steel plate with raised printing approximately 1 mm in height on the surface. Example 2 A hollow box with an opening was used in place of the metal blade used in Example 1, and the powder coating was supplied from inside the box through the opening for printing. However, similar results were obtained. Example 3 The printing substrate was a wallpaper-backed paper coated with a polyethylene resin extruder to a thickness of 20μ, and on top of this was a Lutzker type rotary screen plate with a diameter of 150 mm and 75 lines, the distance from the bottom surface being The circumferential speed of the screen plate and the speed of the printing paper were set to be equal while maintaining the distance to 2 mm. 200 meshes of polyethylene resin powder was supplied inside the screen plate, and was dropped from the opening (image area) of the screen plate using a metal doctor blade fixed inside the screen plate to a height of 2 mm on the printing paper. Polyethylene resin powder was deposited. Next, the printed paper was exposed to hot air at 150°C to melt the polyethylene resin powder, and then cooled, yielding wallpaper with raised prints about 0.5 mm in height. Example 4 A strip-shaped endless screen plate with a width of 1 m and a circumference of 2 m, which uses a polyethylene screen with a wire diameter of 500 microns and 7 meshes, and has a desired opening is stretched in a triangular shape by three pulleys. A metal doctor blade was set in the center of the horizontal part so that the tip lightly touched the inner periphery of the plate. As the printing base material, an uncured asbestos sheet coated with vinyl chloride resin plastisol is used, and a gap of 5 mm is created between the surface of the sheet and the bottom surface of the screen plate at the lowest position of the plate. The distance between the plate and the printing substrate was adjusted accordingly. Adjust the speed so that the plate rotation speed and the asbestos sheet movement speed are equal.
After feeding 30 mesh of PVC resin dry blend powder into the inside of the plate and depositing the powder onto the fully cured PVC resin layer on the asbestos sheet through the opening of the plate, the asbestos When the sheet was introduced into hot air at 200°C to melt and gel the entire sheet, and then cooled, a long flooring material with raised printing about 2 mm in height was obtained. The resulting flooring material was extremely strong, with the resin in the raised portion and the resin in the base coat portion being integrally bonded together.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
The figure is an explanatory diagram showing an embodiment of the present invention when a rotary screen plate is used as the screen plate.
Fig. 3 is an explanatory diagram showing an embodiment of the present invention when a belt-shaped endless screen plate is used as the screen printing plate, and Fig. 4 shows the state of use of a box for distributing powder and granules that can be used in the present invention. An explanatory diagram, FIG. 5, is an explanatory diagram showing a raised printed matter obtained by the present invention. 1, 6, 11, 20, 26... printing base material, 2...
... Screen plate, 3, 8, 13, 22 ... Opening, 5, 10, 15, 24 ... Powder, 4, 9,
14...Hera, 7...Rotary screen version,
12... Band-shaped endless screen version, 23...
Box body, 27...raised part.

Claims (1)

[Claims] 1. A screen plate having desired openings is placed above a printing substrate held substantially horizontally with a certain gap therebetween, and then a resin composition that is melted by heating is applied to the substrate. After depositing the granular material on a desired portion of the printing substrate at a height corresponding to the gap by dropping the granular material from the opening of the screen plate onto the printing substrate, The printing substrate on which the granular material has been deposited is heated to the melting temperature of the resin composition constituting the granular material to fix the granular material onto the printing substrate, and the surface of the printing substrate is heated. A raised printing method characterized in that a raised portion is provided in a portion corresponding to the opening of the screen plate. 2. A flat screen plate having a desired opening is held horizontally above the printing substrate which is placed horizontally, with a certain gap maintained, and the granular material supplied to one end of the top surface of the flat screen plate is By moving it to the other end with a plate-shaped spatula whose tip is in contact with the flat screen plate, it is dropped onto the printing substrate through the opening of the flat screen plate, and the lower surface of the flat screen plate and the printing substrate are separated. The raised printing method according to claim 1, characterized in that the powder is deposited at a height corresponding to the gap between the powder and the upper surface. 3. A rotary screen plate having desired openings is used as the screen printing plate, and the powder and granules supplied inside the rotary screen plate are fixed in a plate shape such that the tip is in contact with the inner periphery of the rotary screen plate. is dropped from the opening with a spatula, and placed on the printing substrate that is being moved at the same speed as the circumferential speed of the rotary screen plate. The raised printing method according to claim 1, characterized in that the powder or granular material is deposited at a height. 4. A plate in which a belt-shaped endless screen plate with desired openings is used as the screen printing plate, and the powder and granules supplied inside the endless screen plate are fixed so that the tip is in contact with the inner surface of the endless screen plate. A space corresponding to the gap between the bottom surface of the endless screen plate and the top surface of the printing base material is placed on the printing substrate, which is moved at the same speed as the circumferential speed of the endless screen plate. 2. The raised printing method according to claim 1, wherein the powder is deposited to a height of about 100 cm. 5. The raised printing method according to any one of claims 1 to 4, characterized in that a thermosetting powder coating that melts and solidifies by heating is used as the powder. 6. A patent claim characterized in that a cylindrical box is hollow inside and has a powder discharge port on one side, and powder and granules are supplied from the inside of the box to the surface of a screen plate. The raised printing method described in item 1 of the scope. 7. Claims 1 to 6, characterized in that after the granular material passes through the openings of the screen plate, excess granular material adhering to the openings is absorbed and removed by negative pressure. The raised printing method described in any one of paragraphs. 8. The raised printing method according to any one of claims 1 to 7, characterized in that a sheet whose surface is covered with an uncured resin film is used as the printing base material. 9. The raised printing method according to any one of claims 1 to 7, characterized in that a surface-treated metal plate is used as the printing base material.