JPH061089A - Screen for printing - Google Patents

Abstract

PURPOSE:To manufacture a plate having excellent quality, antistatic property, excellent adhesion to sensitive emulsion and free from adhesion of dust, by forming a metal compound thin film by spattering on top and rear faces of a mesh fabric, in a screen for printing consisting of synthetic fiber mesh fabric. CONSTITUTION:A mesh fabric is made in such a manner that a texture woven with synthetic fiber is washed by nonionic or anionic surface active agent aqueous solution, heated so as to give tension, and set to a predetermined thickness and the number of meshes. On both faces of the mesh fabric, conductive metal thin films are formed by a metal spattering device. The mesh fabric treated in this way is stretched. The stretched mesh fabric is coated with photosensitive or thermosensible resin emulsion repeatedly so as to make a predetermined thickness. Thereafter, the dried mesh fabric is exposed or heated and finished finally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing screen using synthetic fibers.

[0002]

2. Description of the Related Art Printing screens are manufactured by using mesh fabrics such as silk, stainless steel, nylon and polyester. Silk has problems in strength and dimensional stability. There is a problem with sex,
In addition, since these are expensive, many of them are made of polyester and nylon at present, and particularly those made of polyester, which are excellent in dimensional stability, have been widely used.

However, these synthetic fiber screens generate static electricity due to friction or the like, and as a result, dust or dust is liable to be troubled by suction and adsorption, and further, ink splashes at the time of printing to cause a precision. There are problems such as making printing impossible.

[0004] Although there is a mesh woven material in which an antistatic agent is kneaded into polyester which is a material of the mesh woven material, it is not suitable for screen printing because of its weak strength and large elongation. Conventionally, in order to solve these problems, a screen to which a conductive resin is attached has been experimentally produced by post-processing after weaving, but this is not uniform in processing and causes a great obstacle to the adhesiveness of the photosensitive resin. Further, a screen using a conductive fiber was also investigated, but it was poor in practical use because it had little effect and interfered with the exposure.

Further, it has been studied to knead and knead a conductive substance into the yarn, but this leads to a decrease in the absolute strength of the screen and is not suitable for printing. In addition, an attempt was made to apply plating to the mesh fabric, but the plating was cracked at the stage of upholstery, which was not suitable for practical use. In addition,
There are techniques for plating mesh fabrics, but they are expensive and have not solved the problems of pollution problems and screen opening clogging.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a printing screen using a synthetic fiber having excellent strength, elongation, initial elastic modulus, chemical resistance, etc., which is antistatic, prevents dust from adhering, and is an ink. It is an object of the present invention to provide a printing screen which is remarkably improved in passability, emulsion coatability, solvent resistance and the like, and is excellent in plate making accuracy and printability.

[0007]

According to the present invention, in a printing screen made of a mesh fabric made of synthetic fibers, the mesh fabric has a metal compound thin film formed by sputtering on both front and back surfaces. Solved the problem very effectively.

That is, the screen of the present invention is characterized in that a sputter-deposited film of an antistatic metal is formed on both front and back surfaces of a mesh fabric suitable for screen printing of 10 mesh or more.

The mesh fabric used in the present invention, for example, is made by weaving a raw fabric woven with a synthetic fiber having a wire diameter of 10 to 300 μm, and washing it with a nonionic or anionic surfactant aqueous solution at 60 to 80 ° C. After 100-190
It is heated to a temperature of 100 ° C., applied with a tension of 100 to 250 kg, and set to a predetermined thickness and mesh number.

A metal thin film having conductivity (for example, a thin film of a metal oxide) is formed on both sides of this mesh fabric with a metal sputtering device, and the surface resistance of this thin film is 10
^Since it is about ³ to 10 ⁸ ohms and is hardly affected by humidity, there is almost no charging phenomenon, and it is possible to obtain a durable antistatic effect with strong adhesive force, which is not affected by water.

The mesh fabric treated in this way is then subjected to a gauze step, and the screen frame may be made of wood, metal or resin, and aluminum is particularly durable, It is preferable in terms of workability and chemical resistance.

A conventional plated screen requires a thick plated layer of 2 μm or more in order to make the plated layer uniform, which easily causes cracks in the step of upholstering and has a charging effect. There were few, many were clogged, and the product suitable for practical use was not obtained. However, the screen of the present invention has a treatment layer of 0.5 micron or less, 0.05
Since it is as thin as ~ 0.005 micron and is sputtered,
With the elongation in the stretch process, cracks do not occur and ink splashing in the printing process described later can be significantly suppressed, enabling precision printing.

There is also a method of plating after covering, but it is not practical because of the high price, the problem of pollution, and the long process time.

Next, the mesh woven fabric that has undergone the cloth-tensioning process is subjected to a coating process of a photosensitive or heat-sensitive resin emulsion.
As the photosensitive or heat-sensitive resin, dichromates such as ammonium dichromate, various diazo compounds, S.I.
B. Q-based photosensitizers, acrylic monomer photosensitizers, etc. are used, and as emulsion resin, gelatin, arabic rubber, polyvinyl alcohol, vinyl acetate, acrylic resin, etc., or a mixture thereof is used. A photosensitive or heat-sensitive resin emulsion is formed by adding an agent and other necessary additives.

The coating thickness of the emulsion on the mesh fabric is
Although it depends on the intended use, the surface of the mesh fabric is modified by sputtering, the coatability is significantly improved compared to conventional polyester products, and it is easy to form a resin layer with a uniform thickness. Is possible. Further, since it has an excellent antistatic effect, it prevents dust and the like from adhering to the surface of the mesh fabric.
It is possible to perform high-quality plate making with extremely reduced pinholes.

After the emulsion is coated by recoating so as to have a predetermined film thickness, the dried mesh fabric is finally finished by an exposure or heating process. The pattern printing depends on the emulsion used, but usually a high pressure mercury lamp, xenon lamp (about 4 Kw),
It is used as a light source and exposed at a distance of about 1 to 1.5 m for 2 to 5 minutes. The integrated light quantity at this time is 300 to 500 millijoules / cm ² .

Since the mesh fabric in which the antistatic carbon is put in the yarn absorbs light, the back surface of the plate is not photo-crosslinked, and the adhesiveness and the plate strength are weakened. However, since the mesh fabric used in the present invention has only a very thin metal oxide film on the surface, the color hardly changes and the back surface of the plate is photo-crosslinked to enable accurate plate making.

The screen of the present invention has an excellent antistatic effect, the adhesion between the resin layer and the mesh fabric is strong, the number of pinholes in the plate is small, the time for the manufacturing process is shortened, the workability is remarkably improved, and the printing is performed. It significantly improves printing durability in the process, prevents ink splashing, and enables precision printing.

[0019]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples. Parts and% in Examples mean parts by weight and% by weight unless otherwise specified. Example 1 First, the physical properties of the polyester mesh fabric used in Examples were compared with those of the polyester mesh fabric kneaded with the antistatic agent. (1) 48 micron polyester 200 mesh fabric (2) 40 micron polyester 250 mesh fabric (3) 35 micron polyester 300 mesh fabric (4) 48 micron polyester 200 mesh fabric mixed with antistatic agent ( 5) Polyester 250 mesh woven fabric with 40 micron antistatic agent kneaded. (6) 300 mesh woven polyester fabric with 35 micron antistatic agent kneaded. Table 1 shows a comparison of the average value with the same wire diameter and the same number of meshes.

Test method: JIS L1068-196
4 Labeled strip tester: Constant speed tension type tester (AG manufactured by Shimadzu Corporation
-500B) Sample condition: sample width 5 cm, gripping interval 20 cm, pulling speed 10 cm / min

[0021]

[Table 1]

As shown in Table 1, the mesh fabric containing the antistatic agent was weak in strength and high in elongation and was not suitable for a printing screen.

Example 2 A metal compound thin film was formed on the surface of the mesh fabric of (1) to (3) by the apparatus shown in FIG. The sputtering apparatus used here is a high frequency sputtering apparatus, and this film is used semipermanently (note that a low frequency apparatus may be used as the sputtering apparatus). The mesh fabric is wound around a roll in the supply chamber 1 and guided from the insertion port 3 through the processing chambers 4 and 5 to the outlet 6 of the winding chamber 7 in the direction of arrow 2. Since the processing chambers 4 and 5 are close to a vacuum, the decrease in the vacuum degree at the insertion port 3 and the ejection port 6 is caused by the transfer port 8 and the ejection port 6 between the insertion port 3 and the processing chambers 4 and 5.
It is prevented by the exhaust pipes 9, 10 and 11 provided in the. Further, the supply chamber 1 and the winding chamber 7 are kept in a vacuum state by a tube 12. The processing chambers 4 and 5 have a main exhaust port 13
Therefore, the processing chamber is evacuated, but once exhausted sufficiently, an appropriate amount of gas is introduced from the gas injection hole 14, while the exhaust from the main exhaust port 13 is appropriately throttled so that the gas in the processing chamber is 1
The regulator 15 realizes a state in which a predetermined value of 0 ⁻⁴ Torr or more is reached and new gas always flows in little by little. In such a state, the metal compound is vapor-deposited on almost the entire surface of the mesh fabric by evaporation from the vapor deposition source 16, and the vapor-deposited substance is taken out from the take-out port 6 to the winding chamber 7.
Sent to and wound up. Although many metal compounds to be sputtered have been tried, the price, the hardness and corrosion of the formed film,
In terms of chemical resistance, commercially available stainless steel (SUS30
4, SUS310) was preferable, the electric characteristics were good, and good adhesion strength was obtained. It is preferable to use Ni or Hastelloy C276. About 0.1 micron is sufficient for the film thickness to be formed on the surface of the mesh woven fabric. The products tested in this example are:
Using SUS304, with the device of Fig. 1, the degree of vacuum is 2.3 x
Sputtering was performed at 10 ⁻⁵ Torr and 1.2 × 10 ⁻⁵ Torr. The operating pressure was 5.0 × 10 ⁻³ Torr, the DC power was 400 W, and the operating speed was 0.3 to 10.0 m / min as shown in Tables 2 and 3. In Tables 2 and 3, 200, 250, and 300 mesh are shown in the screen dyed columns, respectively, for polyester mesh fabrics of Table 1, (48 microns, 200 mesh), (40 microns, 250 mesh) and (35 mesh). Micron, 300 mesh). Tables 2 and 3 show the results of the electrification test of the products subjected to the one-side treatment and the both-side treatment. However, the charging test is 20
It was carried out at 65 ° C. and 65% RH.

[0024]

[Table 2]

[0025]

[Table 3]

The electrification voltage of the untreated mesh fabric is 4500
At ~ 6000 mV, the half-life is 60 seconds or more, but as is clear from the results of Tables 2 and 3, the product of the present invention can significantly reduce both the charged voltage and the half-life. It was also confirmed that this effect was further enhanced by double-sided treatment. Since the metal oxide film is formed only slightly on the back surface in the single-sided treatment, the antistatic effect is inferior to that in the double-sided treatment.

Example 3 The mesh fabric treated in Example 2 is then sent to the cloth-laying step. In the subsequent steps, static electricity causes various obstacles in workability, quality and precision plate making and printing steps. Then, No. 13-24 of Example 2 and No. 37-4
The mesh fabric of No. 8 was frame-tensioned with a gauze machine. At the same time, for comparison, the plated mesh fabric and the mesh fabric made of carbon yarn were similarly framed.
Table 4 shows the results of visual evaluation of the state of the finished product. The conditions for the upholstery are as follows. Gauze machine: Mino group 3S air stretcher Aluminum frame: Commercial product 880 x 880 mm square (width 40 mm,
Thickness 25mm) Tension: 1.0 (75B tension gauge)

[0028]

[Table 4]

As shown in Table 4, the plated mesh fabric was cracked and could not be put into practical use.

Example 4 Nos. 13 to 24 and Nos. 37 to 48 stretched in Example 3
The product and the carbon thread mesh fabric are washed with 0.2% neutral detergent aqueous solution and dried, and then polyvinyl alcohol-
A vinyl acetate type photosensitive emulsion was applied, dried, and recoated to give a film thickness of 10 to 12 μm. On these mesh fabrics, a grid pattern of 0.5 mm square, 20 rows × 50 rows was printed. This printing was performed by using a 4 Kw high pressure mercury lamp and exposing at a distance of 1.5 m for 3 minutes. The integrated light quantity in this case was 400 millijoules / cm ² . Then
After soaking in water for 3 minutes, the unexposed portion was removed by water spray. The mesh fabric obtained by baking the cross-cut pattern thus obtained was evaluated for the state of pattern burning from the back surface and the state of pinholes (adhesion of dust), and a tape peeling test was performed. These test results are shown in Tables 5 to 7 in comparison with the results of the conventional polyester mesh fabric (Super Strong made by Nippon Special Fabric). The tape peeling test method is as follows. Sumitomo 3M filament tape # 880 was applied to each mesh fabric on the pattern, and then the tape was peeled off. Do this operation 3
The operation was repeated, and the number of grids (number per 1000 pieces) attached to the tape at that time was recorded.

[0031]

[Table 5]

[0032]

[Table 6]

[0033]

[Table 7]

As is clear from Tables 5 to 7, in the case of the mesh fabric containing carbon yarn, the back surface of the plate is inferior and the adhesion to the emulsion is also inferior, so that a precision plate cannot be produced. In addition, a simple polyester mesh fabric has poor adhesion to the emulsion and has many pinholes. However, with the mesh fabric of the present invention, the plate state is extremely good, there are few pinholes and dust adhesion, and the adhesiveness to the emulsion is also good, making it possible to manufacture precision plates.

Example 5 Next, the plate making of the mesh fabric of the present invention and the plate making of the polyester mesh fabric were subjected to a printing step, and a reproducibility test of fine lines of the printed matter was carried out by the following method. The results are shown in Table 8
Shown in. Test method Thickness of 50 μm 60 μm 80 μm 100 μm 125 μm 150 μm 200 μm 250 μm 300 μm fine line patterns, each having 5 lines arranged at equal intervals, are printed in the same manner as in Example 3 to produce a plate, and printing is performed to obtain fine lines. The reproducibility was judged. The conditions for plate making, squeegee, and printing are as follows. Plate-making conditions: Tension machine: 3S air stretcher made by Mino Group Aluminum frame: Commercial product 880mm x 880mm square Tension: 1.00mm Emulsion thickness: 12μm Image: 300mm x 300mm Squeegee condition Type: Urethane hardness: 70 degrees Angle: 75 Degree width: 405mm Printing condition Gap: 3.0mm Printing pressure: 1.5mm Ink viscosity: 200PS

[0036]

[Table 8]

The static electricity in the printing process is a major factor causing ink splashes and hinders precision printing. However, as is clear from the results in Table 8, the electrification voltage is 500.
Printing on a plate having a screen of V or less and having no backside exposure does not cause ink splashing and is excellent in fine line reproducibility.

[0038]

The product of the present invention, by the antistatic treatment,
The effect is semi-permanent even in the step of stretching, has excellent adhesiveness with the photosensitive emulsion, does not hinder exposure, does not easily attach dust, etc., and enables production of a high-quality plate. In addition, ink splash does not occur in the printing process, precise printing is possible, pollution prevention, time reduction between processes, and remarkable improvement in workability are recognized. Further, not only general screen printing but also printing for printed boards such as printed circuits, multi-layer boards and IC circuits can be precisely printed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a sputtering device used in an example.

[Explanation of symbols]

 1 Supply Chamber 2 Arrow 3 Insertion Port 4 Processing Chamber 5 Processing Chamber 6 Outlet 7 Winding Chamber 8 Transfer Port 9 Exhaust Pipe 10 Exhaust Pipe 11 Exhaust Pipe 12 Pipe 13 Main Exhaust Port 14 Gas Injection Hole 15 Regulator 16 Deposition Source

Claims (1)

[Claims] 1. A screen for printing, comprising a mesh fabric made of synthetic fibers, wherein metal compound thin films are formed on both front and back surfaces of the mesh fabric by sputtering.