JPS63170034A - Polyester mesh for screen printing - Google Patents

Abstract

PURPOSE:To prevent the lowering in the strength of a mesh and to enhance the close adhesiveness of the mesh with a photosensitive resin, by forming recessed and protruding parts to the surface of the polyester fiber constituting the mesh and setting the diameter and number thereof to specific values. CONSTITUTION:Low temp. plasma treatment is preliminarily applied to a polyester mesh in non-oxidatative gas of 0.005-5 Torr and fine recessed and protruding parts having a diameter of 0.01-0.1mum are generated on the surface of the fiber constituting said mesh at density of 1001-6000/mum<2>, pref. 2000-4000/mum<2>. The power applied between the electrodes of a low temp. plasma generator is pref. controlled to 150 KW/m2 or less per the area of the anode. As the non-oxidative gas to be used, He, Ne, Ar, R2, N2 or the like are used and these gases are used alone or in a mixed state, The pressure of the gas at the time of low temp. plasma treatment is set to 0.005-5 Torr and the plasma treatment is desirably performed under pressure of 0.01-1 torr. The irradiation time of low temp. plasma is desirably suppressed to 100 sec. or less and, when plasma irradiation is performed for 100 sec or more, it is not preferable since the lowering in the strength of the mesh is also generated.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a polyester mesh for screen printing, and in particular a mesh that does not cause a decrease in the strength of the mesh and has improved adhesion to a photosensitive resin. It provides:

[Prior Art] The screen printing method performed using the polyester mesh of the present invention belongs to the stencil printing method, and involves applying a photosensitive resin to a mesh-like fabric stretched over a frame, developing it, and removing unexposed areas. to form a pattern for printing. Urethane rubber or the like is used to pass ink through the holes on the mesh created by removing this unexposed resin, and a predetermined printing is performed on the printing material.

Raw materials for the screen mesh used in this printing method include silk, nylon, polyester, and stainless steel, but polyester is increasingly being used due to its elastic recovery rate, cost, etc.

However, since polyester has a highly smooth surface and low wood affinity, its adhesion to photosensitive resins has been inferior compared to other materials. For this reason, when a fine pattern is developed on polyester mesh, it is easy for the pattern to peel off during development, and when washing the pattern surface with a solvent during printing, or using a rubber called a squeegee to allow the ink to pass through, the pattern tends to peel off. Even when pressure is repeatedly applied to the polyester mesh, pattern separation occurs from the mesh, which is a major problem in screen printing using polyester mesh.

Conventionally, various chemical treatments and flame treatments have been used to improve the adhesion of polyester mesh, but satisfactory adhesion has not been achieved, and this results in a decrease in the strength of the mesh, making it difficult to attach the mesh to a frame. There were problems such as the plate breaking during printing.

In addition, it has been pointed out that the mesh tends to break due to external troubles during printing, such as when an edge of the printing material hits the mesh.

[Structure of the Invention] The inventors conducted intensive research to improve the above-mentioned problems. As a result, the polyester mesh was
Low-temperature plasma treatment with non-oxidizing gas of ~5 Torr, the mesh fiber surface has a diameter of 0.01~0.1 μm,
Density is 1001 to 6000 pieces/μm2, preferably 20
The present invention was achieved by discovering that all of the above problems can be solved by producing fine irregularities of 00 to 4000 pieces/μm2.

The polyester mesh proposed by the present invention, which has excellent adhesion to photosensitive resin and has excellent strength properties, is made of polyester filaments with a thread diameter of 10 to 200 μm.
It can be obtained by weaving into ~500 meshes, finishing through processes such as scouring and heat setting, and subjecting it to low temperature plasma treatment under the limited conditions shown below.

The plasma treatment conditions include low-temperature plasma of non-oxidizing inorganic gas of 0.005 to 5.0 torr. As a method for performing low temperature plasma treatment, the mesh is held in a low temperature plasma generator capable of reducing pressure, and a non-oxidizing inorganic gas is passed under low pressure between the electrodes at a frequency of, for example, several kHz to several hundred MHz. This is done by applying high frequency power. Note that as the discharge frequency band, in addition to the above-mentioned high frequency, low frequency, microwave, direct current, etc. can be used.

In the present invention, the low-temperature plasma generator is preferably an internal electrode type, but may be an external electrode type depending on the case, or may be a capacitive coupling such as a coil type, or an inductive coupling. .

However, whatever method is used, it is necessary to prevent the surface of the treated object from being altered by the discharge heat.

The method of the present invention is preferably carried out using the internal electrode method as described above, but there are no particular restrictions on the shape of the electrodes, and the input side electrode and the ground side electrode may have the same shape or different shapes. They may have any shape, such as a flat plate, a ring, a rod, or a cylinder, and may even be of a type in which the metal inner wall of the IA embedding device is grounded as one electrode. Copper, iron, aluminum, etc. are generally used for the input terminal electrode, but in order to maintain a stable discharge, a withstand voltage of 10,000 is required.
It is preferable that the insulation coating is made of glass, enamel, ceramic, or the like having V or more. In particular, rod-shaped electrodes coated with insulation are suitable for generating locally effective plasma.

Regarding the electric power applied between the electrodes, if it is too large, the object to be treated will be decomposed and deteriorated due to heat generation etc., which will lead to a decrease in the strength of the mesh, which is not preferable. From this point, the power applied between the electrodes is 15 per area of the positive electrode.
It is preferable to control it to 0 kW/m' or less.

The non-oxidizing gas used in the present invention is lle.

Ne, Ar, N2, N2, etc. are used, and these gases are used alone or in combination.

Gases containing oxygen atoms, such as 02, Air, Co, and CO2, are not preferred because they tend to cause relatively large unevenness with a diameter of 0.1 μm or more on the mesh surface, resulting in a decrease in the strength of the mesh.

The gas pressure during the low temperature plasma treatment is preferably 0.005 to 5 torr, preferably 0.01 to 1 torr. A gas pressure of less than 0.005 torr or more than 5 torr is preferable because it becomes difficult to generate plasma, or causes relatively large irregularities on the mesh surface due to abnormal discharge or heat generation, leading to a decrease in the strength of the mesh. do not have.

It is desirable to suppress the irradiation time of the low-temperature plasma to within 100 seconds; if the plasma irradiation is performed for longer than that, the strength of the mesh will decrease, which is not preferable.

By performing low-temperature plasma ablation under the above conditions, the present invention proposes a diameter of 0.01 to 0.1 μm and a density of 100 μm.
A polyester mesh having fine irregularities of 1 to 6000 pieces/μrr12 is obtained.

Since the polyester mesh according to the present invention has the above-mentioned fine irregularities, it has excellent adhesion to the photosensitive resin and also exhibits excellent properties in terms of mechanical strength.

A mesh having large irregularities with a diameter of 0.1 μm or more formed on its surface is not preferred because its mechanical strength is significantly reduced.

The polyester mesh for screen printing proposed by the present invention is stretched on a printing frame according to a conventional method, and then coated with a photosensitive resin or laminated with a photosensitive film. As mentioned above, the screen according to the present invention has fine irregularities, so it has high affinity with photosensitive substances.
Therefore, because of the excellent coating properties of the photosensitive material, it is possible to prevent the formation of any holes in the coating film, which were often seen when coating conventional meshes with photosensitive emulsions.

Also, when attaching photosensitive films, the hydrophilicity of the mesh surface is improved by the presence of fine irregularities, so when attaching the film using water, the mesh retains water better and the film can be applied evenly. I can do it.

The mesh coated with or laminated with a photosensitive material is exposed to light using an appropriate light source and developed to become a printing plate for screen printing.

[Effects of the invention] The printing plate formed using the polyester mesh of the present invention has excellent adhesion to the pattern made with the photosensitive material, and the solvent resistance and rigidity resistance of the plate are significantly improved. do.

Even during printing, the printing plate using the novel mesh of the present invention is excellent in ink permeability because the mesh has increased wettability. Therefore, it is suitable for printing with high viscosity ink such as paste printing, and pinholes are no longer observed in solid printing.

The present invention will be explained in detail below with reference to Examples.

Example 1 After setting a polyester mesh having a mesh number of 300 (Super Strong T No. 3005, manufactured by Nippon Tokushu Textile ■) into a low-temperature plasma outer ring device, the pressure was reduced to 0.003 torr. In this state, helium gas was vented and the pressure was adjusted and maintained at 0.06 torr, then 11
0 kl (z, a power of 10 kW/m2 was applied per positive electrode, and plasma treatment was performed for about 1 second).

When the surface of this mesh was observed using an electron microscope, the diameter was 0.01~0.05 am, and the density was 2000~
There were 2,500 unevenness/μ2.

After gauzing the thus obtained mesh according to a conventional method, the photosensitive emulsion EXCEL 53S (manufactured by Kurita Chemical Research Institute) was applied.
was applied to a film thickness of 12 μm, and approximately 1,600 0.25 mm square goblets were baked. Exposure conditions were as follows: 1 minute exposure using a 4 kW high pressure mercury lamp (manufactured by Oak Seisaku Shin). Apply Baklon Tape Y683 (product name manufactured by Sumitomo 3M ■) to the pattern obtained in this way, rub it strongly with your finger, then tear it off. Record the number of stitches that have been removed on the tape, and record the number of stitches that have been separated from the tape. (Table 1).

The tensile properties of the mesh and the strength when the printing plate was torn with a nail were also investigated (Table 2).

Note that the tensile test was conducted in accordance with JIS L 1091i.

However, the printing plate used was a 56 cm square frame with zero outer dimensions, and the tension of the printing plate during the test was 1.1 to 1.2 mm using 5TG75B (trade name, manufactured by Sun Giken ■).

Table-1 Table-2 Comparative Example 1 In the implementation group η1, the plasma irradiation conditions were oxygen 2 Torr,
A mesh was created in the same manner, except that the applied power was 100 kW/m2 (per positive electrode area) and the irradiation time was 30 seconds.
Table 3 shows the results of the tensile test and measuring the strength when the printing plate was torn with a nail.

Furthermore, according to electron microscope observation, this mesh has a diameter of 0.1~
Asperities of 0.5 μm were present at a density of 20 to 30 pieces/μm 2 .

Table 3 Example 2 A polyester mesh with a mesh number of 255 (SRT No. manufactured by NBC Kogyo ■) was put into the low temperature plasma processing apparatus.

255T white) was set, and the plasma irradiation conditions were argon 0.021 l, applied power 20 kW/m2 (per positive electrode area), and irradiation time 2 seconds.

According to electron microscopic observation, the obtained mesh had a diameter of 0.02-0.
There were 2,000 to 2,300 irregularities of 0.05 μm/μm2.

Using the above mesh and under the same conditions as Example 1, 1 c
I burned 10 m-square goban stitches. Dotite FC-404 (Fujikura Kasei ■) was printed on this printing plate, the weight of the printed matter was measured, and the ink permeability was evaluated. (Table-4
) However, the amount of ink permeation was determined by measuring the total weight of 100 printed sheets.

Table-4 Procedural amendment April 8, 1985 1. Indication of the case 1986 Patent Application No. 1448 2. Name of the invention Polyester mesh for screen printing 3. Person making the amendment Relationship to the case Name of patent applicant (206) Shin-Etsu Chemical Co., Ltd. “Spontaneous” l) Indicates “…” on page 7, line 10 of the specification.j
After that, add the following.

Claims (1)

[Claims] A polyester mesh for screen printing, which has irregularities on the surface of the polyester fibers constituting the mesh, the diameter of which is 0.01 to 0.1 μm, and the number of irregularities is more than 1000 and less than 6000 per μm^2.