JP2603481B2 - Mesh fabric for printing screen - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mesh fabric for a printing screen using composite filaments, which is particularly excellent in preventing halation at the time of exposure and exposure, and enables delicate pattern printing. The present invention relates to a mesh fabric for a printing screen.

Prior Art As a printing screen fabric, a mesh fabric made of silk or stainless steel has been widely used, but silk has problems in strength and dimensional stability, and stainless steel has problems in elastic recovery and instantaneousness. In addition, since these are both expensive, mesh fabrics made of polyester or nylon are often used at present.

In particular, polyester mesh fabrics are often used because of their excellent dimensional stability, but polyester screens have the following disadvantages.

a) White powder scum is generated during weaving, which is likely to cause various obstacles. b) Emulsion coating property is poor. c) In order to form a uniform film thickness, a large number of overcoats are required using a craftsman technique. D) low productivity; e) poor adhesion between the mesh and the emulsion resin, poor print resistance, and the like.

Conventionally, in order to solve these drawbacks, various methods such as chemical treatment with acid or alkali, flame treatment, corona treatment, etc. have been studied. At present, no practical improvements have been made.

However, with the diversification of the printing field, the demand for printing accuracy and printing resistance has been increasing, and the dimensional stability of the stainless steel screen, the adhesion with the emulsion resin of the nylon screen, and the elastic recovery of the polyester screen have been combined. There is a strong demand for screen development.

JP-A-59-142688 discloses an antistatic screen gauze using a composite filament, which is intended to improve the antistatic property of the screen gauze and is made of conductive carbon black. It is characterized by using a thermoplastic synthetic polymer containing the same, and no solution has been shown for the improvement of printing accuracy and printing resistance which has been a problem in the past.

Problems to be Solved by the Invention The present inventors have solved the above-mentioned problems of the conventional method by using a composite filament, and have all of dimensional stability, adhesion to an emulsion resin, and elastic recovery. In addition, we succeeded in developing a mesh fabric for printing screens with excellent printing accuracy and printing resistance, and applied for a patent as Japanese Patent Application No. 62-35252, but simply used a transparent or white mesh fabric for screen production. However, the halation at the time of exposure / exposure is strong, and the pattern printed on the screen is blurred or fogged. Is difficult to obtain with high accuracy.

With the diversification of the printing field, the demand for higher density and higher precision of the pattern on the printing screen has been increasing year by year. Therefore, the present invention improves the mesh fabric for the printing screen developed earlier, It is an object of the present invention to provide a mesh fabric for a printing screen capable of printing, which can produce a fine pattern on a screen plate with good reproducibility without causing halation by the method, and has excellent printing accuracy and printing resistance. Aim.

Means for Solving the Problems In the present invention, as described in detail in the specification of Japanese Patent Application No. 62-35252, the core-sheath structure of the composite filament is used in a mesh fabric made of a characteristic core-sheath type composite filament. In addition, the above object has been achieved by imparting light absorptivity to light that is exposed to the sheath surface during the production of the screen plate.

That is, the mesh fabric of the present invention is made of a core-sheath composite filament having a sheath having a good adhesive property with an emulsion or a resin of a screen and a core having a material excellent in dimensional stability and elastic recovery. As a 5 cm wide test piece, the label strip method was used to set the
When the strain curve is measured, the elongation at break is 15-40%
When the breaking strength is 25 kgf or more and the elongation is 5% or more, the relationship between the strength Y (kgf) and the elongation X (%) is Y ≧
(X + 1) × 5/3, and the sheath surface of the composite filament has a light absorbing property with respect to light exposed at the time of manufacturing a screen plate.

The mesh fabric of the present invention uses a polyester or polyolefin having excellent dimensional stability and elastic recovery as a core material of the composite filament, guarantees dimensional stability of the screen, and adheres to a resin or the like as a sheath material. The use of polyamide or low-viscosity polyester with good properties prevents the occurrence of white powder scum during weaving, which is a drawback of ordinary polyester screens, and improves screen strength, emulsion coatability, ink permeability, etc. can do.

In addition, by designing the relationship between the strength and elongation of the woven fabric in the specific range as described above, the workability in the gauze process during screen production and the dimensional stability of the screen are remarkably improved, and the plate in the printing process is further improved. In addition to improving the high-tension print resistance, not only enables application to precision printing, for example, the conventional synthetic fiber mesh fabric, such as the San Giken 75B type tension gauge tension of 0.60 or less, such as Even high-tension screens that were not possible can be manufactured with good workability.

In particular, in the present invention, in such a mesh fabric, in order to form the sheath surface of the composite filament so as to absorb light of a certain wavelength, when manufacturing a screen plate by photoengraving, light is reflected. This makes it possible to produce a high-quality screen plate without causing blurring or fogging in the pattern printed on the screen and having no halation for any pattern.

The antihalation effect in the present invention can be easily achieved by uncoloring or dyeing only the sheath portion without affecting the core portion, since the sheath portion of the composite filament may be provided with light absorbency. As will be described later, a more reliable effect than before can be obtained without substantially affecting the strength of the fabric or the production cost.

The polyester, polyolefin and the like constituting the core component of the composite filament used in the present invention must have an appropriate viscosity at the spinning temperature determined in relation to the sheath component during spinning. Terephthalate, copolymerized polyalkylene terephthalate, poly [1,4-cyclohexanediol terephthalate] and the like are used, but after weaving, in order to ensure dimensional stability in the heat setting at the processing stage, polyethylene is used. The use of terephthalate, polybutylene terephthalate and poly [1,4-cyclohexanediol terephthalate] is preferred, and the use of economically available polyethylene terephthalate is particularly preferred.
As the polyolefin, polyethylene, polypropylene, polybutene-1 and the like can be used. From the viewpoint of stability during spinning and ease of handling, polyethylene and polypropylene are preferable, and use of polypropylene is particularly easy to select a spinning temperature. Is preferred.

Examples of the polyamide constituting the sheath component include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, condensed polyamide of paraaminocyclohexylmethane and dodecanedioic acid, polyxylylene adipamide, and polyhexamethylene. Any aromatic polyamide such as phthalamide can be used, but nylon 6 and nylon 66 are preferred from the viewpoint of easy spinning and economy.

In the form of the composite filament, it is important that the sheath component is continuously present over the entire circumference of the fiber cross section and the core component is not exposed. The cross-sectional shape of the fiber may be an ordinary round cross-sectional shape, and the arrangement and shape of the core component are not particularly limited, and any of single-core, multi-core, round cross-section, irregular cross-section, concentric, and eccentric can be used. However, in order to guarantee the dimensional stability, a concentric single-core arrangement having a round cross section in which stress is not dispersed or a multi-core arrangement having a round cross section is preferable.

The ratio of the core component to the sheath component is preferably 1: 5 to 3: 1 by volume, and particularly preferably 1: 2 to 2: 1. If the amount of the sheath component is too small, the sheath film becomes too thin, the thickness unevenness occurs at the time of spinning, and the film is easily broken, or the film is broken due to external stress during weaving, gauging or printing. Sometimes. Conversely, if the core component is too small, these disadvantages will not occur, but the resistance to tensile stress will be small,
The screen lacks dimensional stability.

The composite filament may be either a monofilament or a multifilament. However, in order to obtain a screen with high printing accuracy, it is generally preferable that the composite filament is a monofilament, and the fineness of the filament is 1d or more. 5-50d
The use of monofilaments is particularly preferred. Note that the fiber diameter is usually preferably 100 μm or less.

In weaving the mesh fabric of the present invention, the composite filament is usually used as a drawn yarn, but in order to guarantee dimensional stability as a screen, its strength is 5.5 g / d.
As described above, the stretching ratio and the heat setting temperature are preferably set at the time of stretching such that the residual elongation is 30 to 50% and the boiling water shrinkage is 10% or less. In particular, it is preferable to use a drawn yarn having a strength of 6 g / d or more, a residual elongation of 35 to 45%, and a boiling water shrinkage of 9% or less.

In general, the weaving density of the woven fabric of the present invention is 10 to 600 yarns / inch (that is, 10 to 600 mesh plain weave).
An appropriate weave density may be selected according to the use as a screen, that is, according to the ink supply amount, the line width of the picture, and the like. Usually, it is preferably 100 to 350 lines / inch.

Raw woven using composite filaments is 60-80 ° C
After washing with an aqueous solution of a nonionic or anionic surfactant, the film is heated to 100 to 190 ° C., tensioned to 100 to 250 kg, and set to a predetermined thickness and a predetermined number of meshes.

After setting, after washing and drying the mesh fabric surface,
The woven fabric of the present invention may be applied to any frame made of aluminum, iron, wood, or resin.

Since the woven fabric of the present invention uses the composite fiber as described above, it does not change with time even after laminating, and after standing for 24 hours, it can be subjected to the next photosensitive or heat-sensitive resin emulsion coating step, The workability of manufacturing the screen plate is also significantly improved.

On the other hand, conventional nylon mesh fabrics cannot be applied to precision printing due to poor change over time, and polyester mesh fabrics also change over time after gauging,
They had to leave for more than 72 hours.

In the production of the screen plate, any of commercially available photosensitive and photosensitive resin emulsions can be applied to the fabric of the present invention. For example, as a photosensitive agent, dichromates such as ammonium bichromate, various diazo compounds, and as an emulsion resin, gelatin, gum arabic, polyvinyl alcohol, vinyl acetate, an acrylic resin or a mixture thereof can be used. Other additives such as emulsifiers and antistatic agents can also be used.

The thickness of the emulsion applied to the mesh fabric varies depending on the intended use.However, the fabric of the present invention has a surface covered with a polyamide having good adhesion to the emulsion, so that it is compared with a conventional polyester screen. Emulsion coating properties are remarkably excellent, and a resin layer having a uniform thickness can be easily formed.

After applying the emulsion to a predetermined thickness, dried,
It is usual to produce a screen plate by exposure or heating, and the printing of the pattern depends on the emulsion used, but usually a high-pressure mercury lamp, xenon lamp, etc. (about 4 kw) is used as the light source. Exposure from a distance of about 1 to 1.5 m for 2 to 5 minutes. The integrated light amount at this time is
300-500 mJ / cm ² .

In order to impart an antihalation effect to the mesh fabric of the present invention, dye absorption may be applied to the fabric surface, that is, the sheath surface of the composite filament, after dyeing the mesh fabric, but the sheath material of the composite filament may be added. Pigments or dyes may be mixed to color undiluted solution, or an ultraviolet absorber may be mixed.

In the case of using ordinary polyester filaments, high-pressure dyeing is required, so dyeing not only has poor workability, but also causes heat shrinkage of the mesh fabric during dyeing,
In addition, although it is difficult to produce a screen pattern having a dense pattern with good performance due to foreign substances easily adhering to the fiber surface, the product of the present invention uses polyamide or the like having excellent dyeability as a sheath material of the composite fiber. Because it can be dyed at normal pressure, it has excellent antihalation effect against exposure during screen plate manufacturing by photoengraving, with relatively little heat shrinkage of the mesh fabric and adhesion of foreign matter to the fiber surface during dyeing. be able to.

Furthermore, in the present invention, it is possible to stably obtain an antihalation effect without mixing dyeing after fabric production by simply mixing a pigment or an ultraviolet absorber into the sheath material of the composite filament. According to this method, the pigment or the like may be mixed only into the sheath material of the composite filament, so that the desired effect can be obtained very economically. Since the screen plate can be manufactured without causing thermal shrinkage, a high-density and fine pattern can be manufactured on the screen plate with extremely high precision than ever before.

In general, in the photomechanical method, since there is a possibility of exposure to light having a wavelength having a peak in the range of 280 to 450 nm, the composite filament is in the range of 280 to 450 nm corresponding to the light used during photomechanical processing. It should be treated so as to have a light absorbing property at at least a part of the wavelengths contained in. In particular, it is preferable that the treatment is performed so as to have a light absorbency of a wavelength of 350 to 400 nm which is easily exposed.

 Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1.6 A circular concentric composite filament having a nylon sheath and a polyethylene terephthalate core and a sheath: core volume ratio of 1: 1 was produced at a spinning temperature of 285 ° C. and a winding speed of 1,000 m / min. A stretching ratio of 3.90, a stretching temperature of 84 ° C,
Stretching is performed at a stretching set temperature of 180 ° C and the fiber diameter is 48μm, 40μ
m and 34 μm were obtained.

Using these composite filaments, five types of mesh fabrics A1 to A5 shown in Table 1 were produced, heat-set, and then tested for their elongation. The results are shown in Table 1 in comparison with the results of polyester mesh fabrics B1 to B5 having the same wire diameter and the same mesh.

Manufacture of woven fabric having antihalation ability A yellow pigment (CIPIG. Yellow No. 83) was added at a rate of 0.01% by weight to the sheath material of the composite filament, and was used in the same manner as A1 to A5 in Table 1, Mesh fabrics X1 to X5 composed of conjugate fibers in which the sheath portion was colored undiluted with yellow were obtained.

Next, the mesh fabrics A1 to A5 of Table 1 were dyed yellow under the conditions of Table 2 to produce mesh fabrics Y1 to Y5 in which the sheath portion of the composite filament was dyed yellow. Further, Table 1 was used as a comparative example. B1 to B5 were dyed yellow under the conditions shown in Table 2 to obtain polyester mesh fabrics Z1 to Z5 whose surfaces were dyed yellow.

The mesh fabric thus obtained exhibits antihalation properties against exposure in photolithography,
As shown in Table 2, the mesh fabrics X1 to X5 made of composite filaments using the uncolored sheath material do not need to use a dyeing process with poor workability. It can be seen that the method can be applied to the production of a screen plate having such a pattern with extremely high quality. In addition, the mesh fabrics Y1 to Y2 of the present invention, even when dyed, do not require severe dyeing conditions, can relatively easily obtain the antihalation performance, and can be relatively deformed due to heat shrinkage during dyeing. Less, even in the screen plate production with a dense pattern, it will be relatively stable can be used, but ordinary polyester mesh fabric Z1 ~ Z5,
It requires severe conditions for dyeing and becomes a product with high heat shrinkage.
It can be seen that it is difficult to apply to the production of a screen plate having a dense pattern.

Example 2 For each of the mesh fabrics X1 to X5, Y1 to Y5, and Z1 to Z5 of Example 1, the state of the fabric surface was photographed with an electron microscope.
Compared. Table 3 shows the results.

From these results, the mesh fabrics X1 to X5 using the undiluted colored composite monofilaments according to the present invention have extremely clean surfaces, and even when dyed, the mesh fabrics Y1 to Y5 using the composite monofilaments according to the present invention are: Mesh fabric Z1 using polyester monofilament
It can be seen that the product is of good quality with less foreign matter adhesion as compared with Z5.

Example 3 The mesh fabrics X1-X5, Y1-Y5 and Z1-Z5 of Example 1
And the non-dyed mesh fabrics A1 to A5 and B1 of Table 1
~ B5 is washed with 0.2% aqueous neutral detergent and dried,
VA-vinyl acetate photosensitive resin NK-14 (manufactured by Hoechst) was applied and dried, and the film thickness was adjusted to 10 to 12 μm by repeated coating.

Table 4 shows the results of baking a fine pattern on each of the mesh fabrics after forming the photosensitive coating film and observing them with an electron microscope.

As is clear from the results, the mesh fabric according to the present invention can prevent halation very effectively by both dyeing and stock solution coloring, and can reproduce a fine pattern on a screen plate with high accuracy (Table 4). X1 to X5 and
In the case of ordinary polyester monofilament mesh woven fabric, the halation prevention effect can be obtained by dyeing, but the fiber surface becomes uneven, the adhesive strength is reduced, and a clear pattern cannot be obtained (see Table 4). Z1 to Z5). In the mesh fabric of the present invention, a pattern can be formed even in an undyed state (see A1 to A5 in Table 4).
In the case of ordinary polyester monofilament mesh fabric, blurring and fogging occur as shown in FIG. 7 and a clear pattern cannot be obtained (see columns B1 to B5 in Table 14).

Example 4 The product obtained in Example 1 was subjected to a strong elongation test in the same manner as in Table 1 of Example 1. Table 5 shows the results.

As is evident from the results in Table 5, the mesh fabrics X1 to X5 according to the present invention have a moderate elongation and are compared with products Z1 to Z5 dyed with a conventional polyester screen.
It shows remarkably excellent strength. Further, the mesh woven fabric of the present invention was practically used, even if it was a product Y1 to Y5 dyed after weaving, with little decrease in strength and elongation.

Example 5 Each of the products obtained in Example 1 was heat-set, and then framed on an aluminum frame with a gauging machine. On this occasion,
At the same time as measuring the compressor pressure of the laying machine in accordance with the change in tension, a mark was made at the center of the mesh fabric at intervals of 50 cm in the vertical and horizontal directions, and the elongation during this was measured.

Table 6 shows the relationship between the tension, the compressor pressure of the stretcher, and the elongation of the mesh fabric. Table 7 shows the time-dependent change of the tension after the stretching.

 The equipment used for the test is as follows.

Gauging machine: 3S air stretcher made by Mino Group Aluminum frame: 880mm x 8805mm Square frame material width 40mm, thickness 25mm Tension meter: Sun Giken 75B type tension gauge From the results of Tables 6 and 7, the woven fabric (X2,
X3, X5) and (Y2, Y3, Y5) are very workable, can be sewn with a stable and high tension, and in particular, a fabric in which the sheath part of the composite filament is given light absorbency by coloring the undiluted solution (X2, X3, X5) show high practicality. On the other hand, the dyeing of ordinary polyester mesh fabrics (Z2, Z3, Z5) increases the elongation at an accelerated rate when the tension is high, making it difficult to form a stable gauze and limiting the application of tension. . Furthermore, the tension change after the stretching is remarkable.

Effect of the Invention The mesh fabric of the present invention is excellent in dimensional stability, and has high strength and excellent adhesiveness with resin, so that it is possible to produce a printing screen with good workability and high accuracy, and There is no blurring or fogging during photolithography, and even ultra-fine patterns can be accurately and clearly reproduced on the screen plate. Therefore, the fineness of the present invention makes it possible to mass-produce a screen that can be stably used for precision printing of electronic components such as printed circuits, multilayer boards, and IC circuits at low cost and with good workability.

Claims (9)

(57) [Claims] 1. A mesh fabric using composite filaments, wherein said composite filaments are made of a material having good adhesiveness to an emulsion or resin of a screen, and a core made of a material having excellent dimensional stability and elastic recovery. Consisting of a core-sheath composite filament, the woven fabric, as a 5 cm wide test piece,
When the stress-strain curve was measured by the labeled strip method with the gripping interval set to 20 cm, the elongation at break was 15
〜40%, the breaking strength is 25 kgf or more, and the elongation of 5% or more, the relationship between the strength Y (kgf) and the elongation X (%) is Y ≧ (X + 1) × 5/3, And a mesh fabric for a printing screen, wherein a sheath surface of the composite filament has a light absorbing property with respect to light exposed at the time of manufacturing a screen plate. 2. The mesh fabric according to claim 1, wherein said composite filament is a monofilament. 3. The mesh fabric according to claim 1, wherein the volume ratio of the core and the sheath is 1: 5 to 3: 1. 4. The mesh fabric according to claim 1, wherein the sheath material of said composite filament is polyamide or low-viscosity polyester. 5. The composite filament according to claim 1, wherein the core material is polyester or polyolefin.
Item 5. The mesh fabric according to any one of Items 4 to 7. 6. The mesh fabric according to any one of claims 1 to 5, wherein at least one of a pigment and an ultraviolet absorber is mixed in the sheath of said composite filament. 7. The mesh fabric according to claim 1, wherein the sheath of said composite filament is dyed. 8. The mesh according to any one of claims 1 to 7, wherein said composite filament has a light absorbing property for light of at least a part of wavelengths in a range of 280 to 450 nm. fabric. 9. The mesh fabric according to claim 8, wherein said composite filament has a light absorbing property for light having a wavelength of 350 to 400 nm.