JPH07373B2 - Screen printing plate making method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a method for making a screen printing plate,
It is an object of the invention to provide a method for producing a screen printing plate capable of printing a fine pattern and having excellent printing durability.

(Prior Art) A direct method, a direct method, and an indirect method are generally used as a method for making a screen printing plate, but the indirect method is the best in terms of dimensional accuracy, formation of a fine pattern, and the like. However, the indirect method has a problem in that the plate film and the mesh are adhered to each other on the screen to make the plate, and thus the plate film and the mesh have poor adhesion, and thus the printing durability is also poor, which is not suitable for mass production.

In order to improve the adhesion of the screen mesh, various chemical treatments, flame treatments, surface treatments such as corona treatment have been performed, but there is a problem that the strength of the material is reduced, etc.
So far, the effect of eliminating the above-mentioned difficulties by the indirect method has not been obtained.

In particular, polyester fibers are superior to nylon fibers in terms of dimensional stability, but have poor adhesion and are not currently used for indirect plate making.

(Structure of the Invention) As a result of intensive research conducted by the present inventors to solve the above-mentioned conventional problems, the present invention has been achieved. This is a polyester set to a predetermined thickness and 100 mesh or more by a conventional method. A screen characterized in that a mesh or nylon mesh is treated with a low temperature plasma of an inorganic gas of 0.005 to 5 Torr to make the surface of the mesh have a wetting index of 40 or more, and then a separately prepared plate film is laminated on the mesh. The main point is the method of making a printing plate.

The method of the present invention will be described in detail below. First, a polyester mesh or a nylon mesh set to a predetermined thickness and 100 mesh or more by a conventional method is subjected to a plasma treatment, but the treatment in this case is a depressurizable plasma. Hold the mesh in the generator, 0.
It is performed by applying a high frequency power of, for example, 10 KHz to 100 MHz between the electrodes while ventilating an inorganic gas under a low pressure of 005 to 5 Torr. As the discharge frequency band, low frequency, microwave, direct current, etc. can be used in addition to the above high frequency.

The low temperature plasma generator is preferably an internal electrode type,
Depending on the case, either an external electrode type or a coil type may be used.

However, no matter which of the above methods is used, it is necessary to prevent the surface to be treated from being deteriorated by the heat of discharge.

Although the method of the present invention is preferably carried out by the internal electrode method as described above, the shape of the electrode at this time is not particularly limited, and the input side electrode and the ground side electrode may have the same shape or different shapes. It may be any of various types such as a plate shape, a ring shape, a rod shape, and a cylinder shape, and may be a type in which the metal inner wall of the processing apparatus is grounded as one electrode. Although copper, iron, aluminum or the like is generally used as the input side electrode, in order to maintain stable discharge, it is preferable that the electrode is insulatingly coated with glass, enamel, ceramic or the like having a withstand voltage of 10,000 V or more. . In particular, the insulation-coated rod-shaped electrode is suitable for locally generating effective plasma.

Regarding the electric power applied between the electrodes, if the electric power is too large, the object to be treated is decomposed and deteriorated due to heat generation and the like, which causes elongation and mechanical strength of the mesh, which is not preferable. From this point of view, the power applied between the electrodes varies depending on the type of mesh, but is preferably 150 KW / m ² or less per positive electrode area.

Examples of the inorganic gas used in the present invention include helium, neon, argon, air, nitrogen, oxygen and the like, and these gases may be used alone or in combination, but from the viewpoint of mesh strength after treatment, helium, neon, Non-oxidizing inorganic gases such as argon and nitrogen are preferred. Further, the plasma irradiation time is not preferable because the mesh surface is excessively roughened or deteriorated when it is exposed to plasma for a long time, and it is preferable to control it within 100 seconds.

Gas pressure in the plasma generator is preferably in the range of 0.005 to 5 torr, preferably 0.01 to 1.0 torr. At a pressure of 0.005 Torr or less, or 5 Torr or more, it is not preferable because it is difficult to maintain stable discharge, and the mechanical strength of the mesh is reduced or the surface is deteriorated due to heat.

The surface of the plasma-treated polyester mesh or nylon mesh is washed, dried, and then stretched by a conventional method.

Next, a step of laminating a separately prepared plate film on the screen mesh is performed. The photosensitive film used for forming the plate film is preferably a polyester film on which a photosensitive resin layer using a chrome or iron salt-based photosensitizer is formed. Plate making is carried out by transferring from the polyester film onto the gauze mesh by such means.

In the screen printing plate according to the method of the present invention, since the mesh fiber is subjected to the low temperature plasma treatment, the adhesion between the plate film and the mesh is very strong, and the printing durability in the printing process is remarkably improved. In particular, chlorinated solvents such as trichlene and methylene chloride, ketones such as acetone and methyl ethyl ketone, alcohols such as methanol, ethanol and isopropanol, aromatic solvents such as toluene and xylene, and other ethyl acetate, butyl acetate, ethyl cellosolve and butyl cellosolve. Since the solvent resistance to cyclohexane and the like is remarkably improved, the durability in the solvent washing step performed in the printing step is remarkably improved. For this reason, conventionally, since solvent resistance is poor, problems such as peeling of the pattern generated in the step of removing the printing ink have been solved and printing durability has been remarkably improved. Unlike the method, it does not suffer from interference of the screen eyes during the exposure, so that fine lines and fine dots can be accurately plate-made, which is a very useful method for multicolor shift such as color printing. By the method of the present invention, the adhesion between the mesh and the plate film is improved, and it is possible to mass-produce the fine printing by the indirect method, which was impossible with the conventional polyester mesh.

Hereinafter, the present invention will be described in examples.

Example 1 Polyester mesh having 250 meshes in a low-temperature plasma generator (Nippon Special Woven Co., Ltd. Super Strong)
T250T) was set and the pressure was reduced to 0.005 torr. In this state, the pressure at which argon was aerated was adjusted and maintained at 0.1 torr, and then high frequency power of 110 KHz was applied and the treatment was performed for about 5 seconds.

At this time, the electric power applied between the electrodes is 30 per area of the positive electrode.
It was KW / m ² . The wettability index of this mesh was 48. The wetting index of untreated one is
It was 34.

Wetting index test method: An ethylene glycol monoethyl ether / formamide solution (wetting index standard solution manufactured by Wako Pure Chemical Industries, Ltd.) set to a predetermined surface tension is applied to the mesh surface, and the surface tension of the wet solution is determined by the wetting index. (According to JIS K-6768).

Next, this plasma-treated mesh was washed with a 0.1% neutral detergent aqueous solution and dried, and then a plate film on which 1500 pieces of 0.2 mm-square and 0.5 mm-square goggles were baked was filled with water by a conventional method.
However, the indirect film used for plate printing was Blue Poly 2 manufactured by Urano Co., Ltd. and was exposed by a 4 KW high pressure mercury lamp (Oak Seisakusho Co., Ltd.) for about 30 seconds to print a pattern.

A tape peeling test and a solvent resistance test were performed on this product, and the adhesion between the mesh and the plate film was examined and compared with that of the untreated plasma. Table 1 shows the results of the tape peeling test, and Table 2 shows the results of the solvent resistance test.

Tape peeling test method: Sumitomo 3M Co., Ltd. on a 0.2mm square goggle pattern
Pakuron tape Y683 was attached to the tape and rubbed strongly with a finger. After rubbing the tape, the tape was peeled off, and the number of burrs attached to the tape was recorded.

Solvent resistance test method: A 0.5 mm square goggle pattern was immersed in methylene chloride for 5 minutes, and then the same tape peeling was performed to record the number of goggles.

Example 2 The number of meshes in place of the polyester mesh of Example 1
270 nylon mesh (N270 manufactured by Nippon Special Weaving Co., Ltd.)
Using T), the same plate making as in Example 1 was performed. However, instead of the goggles pattern, 20 positive patterns with a line width of 100 μm (line spacing 100 μm) were formed on the mesh. A tape peeling test similar to that of Example 1 was conducted by applying a tape to this product in parallel with a 100 μm line. Table 3 shows the results.

Claims (1)

[Claims] 1. A polyester mesh or nylon mesh set to a predetermined thickness and 100 mesh or more by a conventional method is treated with a low temperature plasma of an inorganic gas of 0.005 to 5 torr, and the wetting index of the mesh surface is set to 40 or more. A method for making a screen printing plate, characterized in that a separately prepared plate film is laminated on this mesh.