JPH0780363B2 - Printing method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing method for forming a printing film on a substrate such as glass, metal or resin using a waterless planographic printing plate, a resin relief printing plate or the like.

2. Description of the Related Art Direct printing on a glass substrate using a conventional waterless lithographic plate is performed by a mechanism as shown in FIG. The ink 3 is filled in the image area of the waterless planographic plate 2 wound on the outside of the plate cylinder 1, and the plate cylinder 1 comes into contact with the glass 4 and moves in the horizontal direction while rotating for printing. Figure 3 (a)). In FIG. 3 (b), the ink 3 filled in the image area is the ink that has adhered to the glass 4 side when it comes in contact with and leaves the glass 4.
3a and the ink 3b on the waterless planographic plate 2 side are torn off and separated. As shown in FIG. 3C, the ink printed by the waterless lithographic plate generally has high viscosity and tack, and has poor fluidity, so that the unevenness of the surface of the ink 3a caused by being torn off during the ink separation is not smoothed.

Problems to be Solved by the Invention However, when there is unevenness on the surface of the ink printed as described above, for example, in a color filter for a liquid crystal color television using an ink in which pigments such as red, green, and blue are dispersed. The thin part of the ink film becomes “white clear”, which causes a defect that the contrast is deteriorated as an image. Even when the resistor ink of the thermal head is printed on the ceramic substrate, if the resistor surface is uneven, printing pressure unevenness occurs when the thermal paper is pressure-bonded by the rubber roller, and accurate recording cannot be obtained. .

Means for Solving the Problems The printing method of the present invention comprises a temporary curing step of curing only the surface of the ink layer adhered to the substrate in a predetermined plane shape, a pressing step of applying pressure to the convex portion of the layer thickness of the ink layer, It consists of a main curing step of curing the ink layer over all layers.

Effect The present invention is to cure only the surface of the ink layer by the means of the constitution described above, and then pressurize the convex portion of the ink layer in the pressing step to make the uncured ink inside the ink layer have a predetermined plane shape independent of the ink. At that time, the ink in the convex portion moves to the concave portion to flatten the ink layer, and the entire ink layer is cured in the final main curing step to obtain a flat printing ink film.

Example Hereinafter, an example of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a process drawing for flattening a printing ink layer.
In FIG. 1 (a), 3a is an uncured ink layer having irregularities printed on the glass 4. Here, consider an ink using a thermosetting resin. FIG. 1 (b) shows a temporary curing step. Radiation or convection heating is performed from the heat source 5 such as an electric heater or a warm air heater to the ink layer from the side opposite to the glass substrate, and only the surface of the ink layer is exposed. Cure
3c. At this time, since the inside of the ink layer is not heated, it remains uncured and has fluidity. FIG. 1C shows the pressing step, in which the ink layer whose surface has been cured is pressed by the press roller 6 which moves in the horizontal direction (left direction) while rotating. Here, the principle of flattening in the pressing step will be described with reference to FIG. That is, a gap 7 equivalent to the average film thickness obtained from the amount of ink attached on the glass substrate and the area of the printed shape is provided between the press roller 6 and the glass substrate 4, and The convex portion of the higher ink layer 3c is subjected to a pressure of 8 by the press roller. Due to this pressure 8, the convex portion of the ink layer 3c is compressed downward, causing a flow 9 to the uncured ink 3a inside the convex portion to a portion where the ink layer thickness is thin, and this flow 9 causes one independent predetermined plane. The ink layer having a shape is flattened. At this time, since the outermost peripheral portion of the ink layer has already been hardened in the temporary hardening step of FIG. 1 (b) and strongly adheres to the glass substrate, the lateral flow of the uncured ink in the pressing step is prevented. As a result, the ink layer does not extend beyond the predetermined plane shape. That is, in the pressing step, the ink layer is flattened within a predetermined plane shape, and the shape does not change.

In this way, only the surface is cured and the inside is uncured ink layer is flattened in the pressing step (Fig. 1 (c)), and then the entire layer is cured in the next main curing step (Fig. 1 (d)). Then, the formation of the flat ink layer is completed.

The same effect can be obtained by pressing a flat press plate instead of the press roller in the pressing process.

Color filters for liquid crystal color televisions require printing of three colors of red, green and blue. By forming an ink layer by the flattening method of the present invention for each color, there is no white spot in each color and uniform printing. A color filter having a film thickness can be manufactured.

EFFECTS OF THE INVENTION The present invention keeps the ink layer in a predetermined plane shape by curing only the surface of the ink layer adhered in a predetermined plane shape of the base material and then applying pressure to the convex portion of the layer thickness of the ink layer. It is possible to form an ink layer having a uniform film thickness as it is. Further, when the present invention is used for printing a color filter for a liquid crystal color television, a flat ink layer without white spots can be formed, and a good image can be obtained on the liquid crystal color television.

[Brief description of drawings]

FIG. 1 is a process diagram for flattening a printing ink layer according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing a flattening principle in a pressing process according to an embodiment of the present invention, and FIG. It is a printing process drawing. 3 ... Ink, 3a ... Uncured ink, 3b ... Cured ink, 4 ... Glass, 5 ... Heat source, 6 ... Press roller.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-43646 (JP, A) JP-A-57-105396 (JP, A) JP-A-61-268496 (JP, A) JP-B-55- 23222 (JP, B2)

Claims (2)

[Claims] 1. A temporary curing step of curing only the surface of an ink layer adhered to a substrate in a predetermined plane shape, a pressing step of applying pressure to a convex portion of the layer thickness of the ink layer, and a curing of all the ink layers. A printing method comprising a main curing step. 2. The printing according to claim 1, wherein in the temporary curing step, a heat source is provided on the side opposite to the ink layer attached to the substrate to heat the ink layer. Method.