JP3483868B2 - Screen gauze for printing - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing screen cloth made of synthetic fiber capable of being photoengraved, and more particularly to enabling precise printing of printed wiring and the like.

[0002]

2. Description of the Related Art As a screen cloth for printing, a fine wire material made of stainless steel and having a diameter of 10 to 50 μm is used as a warp and a weft to weave a 100 to 800 mesh raw fabric, and stainless steel is sputter-deposited on both sides of the fabric. It is known that the above warp and weft are coated with a vapor deposition film of stainless steel having an amorphous structure and a thickness of 10 to 1000 nm (see Japanese Patent Laid-Open No. 8-118835). This printing screen gauze is superior in wettability to printing ink, toner, and printing paste, as compared with the above-mentioned screen screen having no vapor deposition film, and enables precision printing.

However, since the surface of the warp and the weft of the above printing screen gauze is made of stainless steel and has light reflectivity, a water-soluble emulsion composed of an ultraviolet curable resin is applied and dried at the time of photolithography. Then, a photosensitive layer is formed, and when one side of the resulting screen is exposed to ultraviolet light through a mask for the original plate, part of the ultraviolet light that has entered the photosensitive layer is reflected on the surface of the warp or weft, and this reflected light However, there is a problem in that the area of the cured portion becomes larger than designed, and the width of the line obtained by printing becomes narrower than designed, because the photosensitive layer of the portion which is not originally exposed is exposed and cured.

On the other hand, as a screen cloth for printing made of synthetic fiber, there is known a cloth made by weaving a monofilament thread made of polyester for warp and weft into a mesh of 100 to 300 mesh. FIG. 1 is a cross-sectional view showing a state in which a photosensitive layer 11 is formed on a conventional printing screen mesh 10 made of polyester. The screen mesh 10 is woven with polyester warps 10a and wefts (not shown), The photosensitive layer 11 is formed by coating and drying a water-soluble emulsion made of the above ultraviolet curable resin.

Reference numeral 12 denotes an original mask, which comprises a transparent portion 12a and a shadow portion 12b. When this original mask 12 is superposed on the surface of the photosensitive layer 11 and ultraviolet rays L are irradiated, a part of the original mask 12 is exposed by the shadow portion 12b. Although it is blocked from entering the photosensitive layer 11, the rest enters the photosensitive layer 11 through the transparent portion 12a and is exposed and cured. Then, the ultraviolet rays L that have entered the photosensitive layer 11 are divided into those that are reflected by hitting the warp threads 10a or wefts, those that penetrate the warp threads and the weft threads even if they hit, and those that penetrate the photosensitive layer 11 without hitting them. A portion La of the reflected light is incident on the photosensitive layer 11 below the shadow portion 12b, and this portion is exposed and cured.

After the above exposure, the screen cloth 10 from which the original mask 12 has been removed is subjected to development, and the non-exposed areas of the photosensitive layer 11 are removed except the exposed areas, and holes through which printing ink or paint can pass. Are formed, and a printing plate (screen type) 13 (see FIG. 2) is obtained. Therefore, when there is no ultraviolet ray La incident on the lower portion of the shadow portion 12b, a hole 13a having the same shape as the shadow portion 12b is formed in the printing plate 13 as shown in FIG. 2 (a). Actually, since the ultraviolet ray La that is incident below the shadow portion 12b exists, as shown in FIG.
The hole 13a formed in the printing plate 13 has a trapezoidal cross section in which the upper portion is substantially equal to the shadow portion 12b and the lower portion is narrow.

This polyester screen mesh 1 for printing
0 is more transparent than the stainless steel printing screen gauze, and the reflected light on the surface of the warp 10a and the weft is less, so the pattern of the original mask 12 is reproduced relatively accurately, and it has elastic elasticity. Since it is rich, the expansion that occurs due to the cage during printing tends to return, but the wettability of toner, printing ink, printing paste and paste (UV paste, glass paste, silver paste, gold paste, etc.) is poor, especially high-speed printing. At that time, it was difficult to carry out precision printing because air bubbles were easily entrained. Further, since the conductivity is low, electrostatic damage due to charging has occurred.

Therefore, it has been attempted to perform physical vapor deposition on both sides of the screen mesh 10 so as to cover the entire warp and weft with a conductive vapor deposition film made of stainless steel. The transparency decreases, and the amount of ultraviolet rays La reflected on the surface increases, so that the area of the cured portion becomes larger than the design, and as shown in FIG. 2B, the holes 13a formed in the printing plate 13 are larger than the design. Becomes smaller,
There was a problem that precision printing became impossible.

[0009]

DISCLOSURE OF THE INVENTION The present invention prevents the incidence of ultraviolet rays on the photosensitive layer below the shadow layer during photoengraving in a screen mesh for printing, which uses monofilament yarn of synthetic fiber as warp and weft. To form holes of the same shape as the original mask on the photosensitive layer, and to improve the wettability of the warp and weft to the printing ink, and to prevent electrostatic damage due to electrification. It makes it possible.

[0010]

A printing screen gauze according to the present invention is a mesh-like raw fabric woven by using thin monofilament yarns of synthetic fibers as warp and weft, and the warp and weft are metal oxides. Is entirely covered with a conductive ultraviolet antireflection film made of a nitride or a carbide, and the ultraviolet antireflection film has a thickness of 3 to 250 nm.
The physical vapor deposition film of, the ultraviolet ray of which wavelength is 350-450 nm
The reflectance is 15% or less and the transmittance is 45% or more .

The above-mentioned printing screen gauze is integrated with a photosensitive layer made of an ultraviolet curable resin by a conventional method at the time of photoengraving, and then an original mask is overlaid on the surface of the photosensitive layer to irradiate it with ultraviolet rays, followed by development, The unexposed areas are washed away with water to form a printing plate (screen type), but the thin monofilament yarns of the synthetic fibers that make up the warp and weft are covered with an anti-reflective coating for ultraviolet light, so they are reflected when exposed to ultraviolet light. The light reflected from the prevention film is greatly reduced.

Therefore, the ultraviolet rays do not enter the photosensitive agent below the shadow portion of the original mask and the area is not cured. Therefore, by developing and rinsing, holes having substantially the same shape as the shadow portion are accurately formed, and the original mask is removed. A printing plate (screen type) having the same pattern is obtained.

Moreover, since the above antireflection film has excellent wettability with respect to printing ink, toner, printing paste, paste and the like, the printing ink or the like smoothly flows from the front surface to the back surface of the warp or weft during printing, The backing is good, and bubbles are not mixed in even when high-speed printing is performed, so that more precise printing is possible. Further, since the antireflection film has conductivity, it does not cause electrostatic trouble due to charging.

The antireflection film of the present invention comprises Ti, Zn, N
It is formed of oxides, nitrides or carbides of metals such as i, Cr, Sn and In, but in particular In SnOx, TiOx,
A physical vapor deposition film made of TiN, TiC, ZnSnOx or the like is preferable. These physical vapor deposition films suppress the level of oxidation to a low level, and by adjusting the processing time during physical vapor deposition to set the thickness of the vapor deposition film to an appropriate size, the reflected light from the warp and weft yarns can be adjusted. Can be canceled with the incident light.

The reflectance of the printing screen gauze provided with the above-mentioned antireflection film is preferably 15% or less with respect to ultraviolet rays having a wavelength of 350 to 450 nm, and if it exceeds 15%, plate making as designed is difficult. become. By selecting the ultraviolet ray having the above wavelength, it becomes easy to select and handle the ultraviolet curable resin. In order to obtain the above reflectance, the thickness of the antireflection film is adjusted to 3 to 250 nm by controlling the vapor deposition time when performing the physical vapor deposition.
It is preferable to set to. Further, the transmittance is preferably 45% or more with respect to the above ultraviolet rays. The above antireflection film may be a single layer, but it is also possible to further reduce the reflectance as a multilayer structure composed of two or more kinds of antireflection films having different refractive indexes.

The above antireflection film has conductivity, and the degree of conductivity is from 10 ³ to 10 ^{3 in} terms of surface resistivity.
10 ¹¹ Ω / cm ² is preferable, and if it is less than 10 ³ Ω / cm ² , the cost increases, while if it exceeds 10 ¹¹ Ω / cm ² ,
Electrostatic charges such as whiskers on the edges of the printed pattern are likely to occur during charging.

In the present invention, the screen gauze before the antireflection film is vapor-deposited, that is, the synthetic fibers constituting the warp and weft of the gauze-like raw fabric, has a strength of 20 g / d or more and an elastic modulus of 500 g / d. The above high-strength superfibers are preferable, and aramid fiber, polyarylate fiber, ultrahigh molecular weight polyethylene fiber, polyparaphenylene benzobisoxazole (PBO) fiber, polyparaphenylene benzobisthiazole (PBT) fiber, and polyparaphenylene benzobis. Examples are polybenzazole fibers such as imidazole (PBI) fibers. And, the preferable diameter of the monofilament yarn composed of these fibers is 15 to 30.
If it is less than 15 μm, it becomes easy to cut, and if it exceeds 30 μm, it becomes difficult to print fine lines.

The density of the above-mentioned raw fabric is 100 to 8 in the history.
00 mesh, especially 250 to 700 mesh is preferred. If this density is less than 100 mesh, it is impossible to print and print precise patterns consisting of fine lines, and on the contrary, 800
If it exceeds the mesh, manufacturing becomes difficult. In addition, the weave structure of the above-mentioned raw fabric is preferably a structure such as a flat structure, which is less likely to cause misalignment and has an opening surface that is uniform in length and width.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 FIG. 3 shows a cross section of a screen mesh 15 according to the present invention, in which a high-strength synthetic fiber called super fiber has a wire diameter of 1
A monofilament yarn of 5 to 30 μm is used as the warp yarn 16 and the weft yarn 17, and after weaving a raw fabric having a plain weave structure of 250 to 700 mesh, the warp yarn 16 and the weft yarn 17 are electrically conductive by sputtering from both front and back surfaces thereof. Antireflection films 16a and 1 having wettability and wettability
It is made by covering the entire surface with 7a.

A water-soluble emulsion made of an ultraviolet-curable resin is applied to the above screen gauze and dried to form a photosensitive layer, and a master mask is placed on the surface of the screen to irradiate it with ultraviolet rays, followed by development and washing with water. A printing plate (screen type) having the same pattern as in (1) is obtained. And since this printing plate has both wettability and conductivity, the backing during printing is also good, and there is no obstacle due to electrostatic charging,
Extremely precise printing is possible.

FIG. 4 shows an example of a sputtering apparatus as a physical vapor deposition apparatus, in which a flat plate-like target 21 made of titanium is fixed to a lower part of a chamber 20 which can be sealed and a surface of the target 21 is fixed on a hollow target source 22. , The target 2 with cold water that is passed through the target source 22
1 is cooled from the lower surface. Anodes 23 are horizontally installed above and below the target 21.
Between the target 21 and the target 21 by the DC power supply E
A DC voltage of 1000 V is applied.

A water cooling cylinder 2 is provided above the anode 23.
4 is horizontally and rotatably installed, and a feed shaft 25 for the raw fabric F made of the monofilament yarn of the super fiber is provided on the upper left side thereof, and a take-up shaft 26 for the intermediate product Fa of the screen gauze is provided on the upper right side. Are installed horizontally and rotatably. Then, the original fabric F wound on the delivery shaft 25 is drawn out, wound on the water cooling cylinder 24 via the upper left guide roller 27a, and wound on the winding shaft 26 via the upper right guide roller 27b. To be A vacuum pump 28, an argon gas supply gas cylinder 29a, and an oxygen gas supply gas cylinder 29b are connected to the chamber 20, respectively.

In the above apparatus, the feed shaft 25, the take-up shaft 26 and the water-cooling cylinder 24 are rotated to produce the original fabric F.
Water-cooling cylinder 2 while feeding counterclockwise at a predetermined speed
4 is cooled, and the surface temperature of the said original fabric W is maintained below 60 degreeC. Meanwhile, the vacuum pump 28 is driven to drive the chamber 2
0 internal pressure is reduced to about 1.3 × 10 ⁻³ Pa, and then argon gas is introduced from the argon gas supply gas cylinder 29a to adjust the internal pressure of the chamber 20 to about 6.6 × 10 ⁻² Pa. Oxygen gas is introduced from the oxygen gas supply gas cylinder 29b to adjust the pressure inside the chamber 20 to 1.3 × 10 ^-1 Pa.
After adjusting to a certain degree, a DC voltage of 500 to 1000 V is applied between the anode 23 and the target 21 to eject titanium from the target 21, and this titanium is reacted with oxygen gas to obtain titanium oxide having a low oxidation rate. This titanium oxide is adhered onto the warp and weft of the above-mentioned raw fabric F, and a half or more circumference of the warp and weft is coated with a titanium oxide vapor deposition film. At this time, the feed rate of the raw fabric W is adjusted to control the thickness of the vapor deposition film to 3 to 250 nm to form an antireflection film, and the intermediate product Fa has an antireflection film on one surface.
To get

Then, the above intermediate product Fa is removed,
This is turned over and attached to the above-mentioned delivery shaft 25, and the second sputtering is performed from the back side, whereby an antireflection film is formed on the remaining half circumferences of the warp and the weft, and a screen gauze of the product is obtained.

When a single metal such as zinc, nickel, chrome, tin or indium or an alloy of indium and tin is used instead of titanium of the target 21,
An antireflection film made of the oxide of the elemental metal or alloy is obtained.

Embodiment 2 In Embodiment 1 described above, nitrogen gas is used in place of oxygen gas, and the same as in Embodiment 1 except that metals such as titanium, zinc, nickel and chrome are reacted with nitrogen gas. Thereby forming an antireflection film made of nitride.

Embodiment 3 In Embodiment 1 described above, methane gas is used instead of oxygen gas, and in the same manner as in Embodiment 1 except for the above, metals such as titanium, zinc, nickel and chrome are used as carbon gas separated from methane gas. The reaction is carried out, whereby an antireflection film made of carbide is formed.

Embodiment 4 As shown in FIG. 5, when two sets of sputtering devices are installed in the chamber, front and back sputtering can be continuously performed. In FIG. 5, reference numeral 30 denotes a closed chamber, a first water-cooling cylinder 31 and a second water-cooling cylinder 32 are juxtaposed on the left and right of the central part thereof, the first water-cooling cylinder 31 on the left side is counterclockwise, and the second water-cooling cylinder 31 on the right side is second. The water-cooled cylinders 32 are driven to rotate in the clockwise direction.

A delivery shaft 33 for the original fabric F is rotatably installed above the first water-cooling cylinder 31, and a winding shaft 34 for the screen cloth Fb is rotatably installed above the second water-cooling cylinder 32. The original fabric F drawn from the delivery shaft 33 is wound around the first water-cooling cylinder 31 via the first guide roller 35a so that the back surface is in contact with the first water-cooling cylinder 31. 35b to be separated, and the upper third guide roller 35
c, the winding shaft 3 is guided by the fourth guide roller 35d.
4, passed through the lower fifth guide roller 35e, and wound so that the surface is in contact with the second water-cooled cylinder 32,
From the second water cooling cylinder 32 to the sixth guide roller 35.
It separates after passing through f and is taken up by the winding shaft 34.

The above-mentioned first water-cooled cylinder 31 and second
Below the water cooling cylinder 32, a pair of left and right first anodes 37 and second anodes 38 are installed.
Then, a water-cooled first target source 39 and a second target source 40 are installed below the first anode 37 and the second anode 38, respectively, and titanium is placed on the first target source 39 and the second target source 40, respectively. The flat plate-shaped targets 31 each made up of are fixed, and a DC power source E having a voltage of 500 to 1000 V is provided between the first anode 37 and the first target source 39 and between the second anode 38 and the second target source 40, respectively. It

In the above structure, the delivery shaft 33, the winding shaft 34, and the water-cooled cylinders 31, 32 are rotated to deliver the original fabric F from the delivery shaft 33 at a predetermined speed.
While being brought into contact with the water-cooled cylinder 31 and the second water-cooled cylinder 32 in order and taken up by the winding shaft 34, the above-mentioned raw fabric F is cooled from the back side in the first water-cooled cylinder 31.
Further, the second water cooling cylinder 32 is cooled from the front side. Meanwhile, a vacuum pump (not shown) connected to the closed chamber 30 is driven to reduce the internal pressure of the closed chamber 30 to about 1.3 × 10 ⁻³ Pa, and then a gas cylinder for supplying an argon gas (shown in the drawing). Argon gas is introduced into the closed chamber 30 to adjust the internal pressure to 6.
The pressure inside the chamber 30 is adjusted to about 1.3 × 10 ^-1 Pa by adjusting the pressure to about 6 × 10 ^-2 Pa and further introducing oxygen gas from a gas cylinder for supplying oxygen gas (not shown).

Then, the above-mentioned first anode 37 and first
Between target source 39 and second anode 38 / second
A direct current voltage is applied between the target sources 40 to eject titanium from the flat target 41 and react with oxygen to form titanium oxide, which is attached to the surface of the raw fabric F on the first water-cooled cylinder 31 and rapidly cooled. To form an antireflection film having an amorphous structure and a thickness of 3 to 250 nm to obtain an intermediate product Fa, and then deposit the above titanium oxide on the back surface of the intermediate product Fa on the second water cooling cylinder 32,
An antireflection film is formed in the same manner, and the product screen F
get b.

When zinc, nickel, chrome or the like is used instead of titanium of the left and right targets 41, an antireflection film made of the oxide is obtained. When nitrogen gas is used instead of oxygen gas, a nitride antireflection film is obtained. When methane gas is used instead of oxygen gas, a carbide antireflection film is obtained.

[0034]

[Example] Using a polyarylate fiber (“Vectran” manufactured by Kuraray Co., Ltd.) as a super fiber, a 600-mesh plain weave having monofilament yarn having a wire diameter of 23 μm as warp and weft is woven, and this is a raw fabric The screen meshes for printing of Sample Nos. 1 to 3 shown in Table 1 below were manufactured. However, Sample No. 1 was used as a screen gauze as it was as the raw fabric. The sample number 2 is the first embodiment.
The target was made of stainless steel, and sputtering was performed in an argon gas atmosphere. Sample No. 3 was manufactured by the method of the first embodiment.

[0035]

[Table 1]

The screen gauze of each of the above sample numbers 1 to 3 is attached to a screen frame (size 320 × 320 mm), a photosensitive emulsion is applied, and the central portion (size 100 × 1) is applied.
The original mask was tightly attached to (00 mm). Then wavelength 200
Irradiate with ultraviolet rays of ~ 450nm, develop and plate-making, UV
A printing test was performed using a paste (“ER-70B” manufactured by Somar), a glass paste (“ELD-520” manufactured by Okuno Pharmaceutical Co., Ltd.) and a silver paste (“LS-504HC” manufactured by Asahi Chemical Co., Ltd.), and before printing. The weight of the printed material (coated paper) after printing was measured, the coating amount of the paste was calculated from the difference, and the performance was compared with this coating amount.

A small printing machine (trade name "LS15GX" manufactured by New Long Precision Co., Ltd.) is used as the printing machine.
The squeegee pressure is 3.5 kg / cm ² , and the pushing amount (the squeegee head descending distance when the tip of the squeegee rubber is brought into contact with the printing object and printing pressure is applied with this position as a reference) is set to 0.
3 mm, off-contact (gap between printing surface of printing plate and substrate) 1.0 mm, squeegee hardness 70 degrees,
The squeegee angle was set to 75 degrees and the printing speed was set to 100 mm / sec. However, the paste application amount was tested 10 times for each of the sample numbers 1 to 3, and the arithmetic average thereof was calculated. The results are shown in Table 2 below.

[0038]

[Table 2]

As shown in Tables 1 and 2 above, Sample No. 1 has the least reflected light, but has poor wettability to the paste and has low conductivity, so that the average coating amount becomes the minimum and electrostatic damage occurs. However, it was not suitable for precision printing. In addition, Sample No. 2 has improved wettability and is superior in conductivity to Sample No. 1, but the physical vapor deposition film on the surface does not have reflectivity, the reflectance of ultraviolet rays is large, and the transmittance is small, The improvement of the average coating amount was insufficient. The sample No. 3 corresponding to the example of the present invention improves the ultraviolet reflectivity and transmissivity of the sample No. 2, and particularly has a low reflectance and a high transmittance for ultraviolet rays having a wavelength of 410 nm near the visible light region, Moreover, since the wettability of the titanium oxide film having conductivity to the paste was excellent, the average coating amount was maximized, the reproducibility of the printed image was excellent, and precision printing was possible.

[0040]

INDUSTRIAL APPLICABILITY As described above, the screen mesh for printing according to the present invention is excellent in reproducibility in photolithography as compared with one having no antireflection film and has a pattern similar to that of the original mask (screen type). ) Is obtained, and precise printing and precise printing become possible. Moreover, the antireflection film is limited to the physical vapor deposition film.
Since it is a fixed product, it is easy to manufacture and has excellent durability.
It In addition, the reflectance and transmittance of the antireflection film are relatively long.
Since it was limited to ultraviolet rays in a certain wavelength range, design
Street plate making becomes easier. In particular, the invention according to claim 2 uses high-strength super fiber for the warp and the weft, so that further precise printing becomes possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a printing screen during photoengraving.

FIG. 2 is a cross-sectional view showing a relationship between an original mask and a printing plate.

FIG. 3 is a sectional view of the embodiment.

FIG. 4 is a cross-sectional view showing an example of a sputtering apparatus.

FIG. 5 is a cross-sectional view showing another example of the sputtering apparatus.

[Explanation of symbols]

L, La: ultraviolet rays 10: screen gauze, 10a: warp 11: photosensitive layer 12: original plate mask, 12a: transparent part, 12b: shadow part 13: printing plate (screen type), 13a: hole 15: screen gauze of embodiment 16: Warp 17: Wefts 16a, 17a: Antireflection film F: Original fabric Fa: Intermediate product of screen gauze Fb: Product of screen gauze 20, 30: Chamber 21, 41: Target 22, 39, 40: Target source 23 , 37, 38: Anodes 24, 31, 32: Water-cooled cylinders 25, 33: Delivery shafts 26, 34: Winding shafts 27a, 27b, 35a to 35f: Guide rollers 28: Vacuum pumps 29a, 29b: Gas cylinder E: DC Power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eigo Nakajima 36 Hamacho, Gamagori-shi, Aichi Prefecture, Suzura Co., Ltd. (72) Inventor Toshikazu 36, Hamacho, Gamagori-shi, Aichi Prefecture, Suzutora Co., Ltd. (72) Inventor Takahiro Suzuki 36 Hama-cho, Gamagori-shi, Aichi Prefecture Suzu-Tora Co., Ltd. (72) Inventor Toru Yokomizo 3-50-50 Toyota, Hino-shi, Tokyo NBC Industrial Co., Ltd. (72) Inventor Hiroshi Otaka 3-50-2 Toyota, Hino City, Tokyo NBC Industry Co., Ltd. (56) References JP-A-63-15795 (JP, A) JP-A-10-331048 (JP, A) (58) ) Fields surveyed (Int.Cl. ⁷ , DB name) B41N 1/24

Claims (2)

(57) [Claims] 1. A conductive ultraviolet antireflection film in which a warp and a weft of a gauze-like raw fabric woven using thin monofilament yarn of synthetic fiber as a warp and a weft are made of metal oxide, nitride or carbide. The entire surface is covered with, and this UV antireflection film has a thickness of 3 to 250 nm.
The physical vapor deposition film of, the ultraviolet ray of which wavelength is 350-450 nm
A printing screen gauze having a reflectance of 15% or less and a transmittance of 45% or more . 2. The printing screen gauze according to claim 1, wherein the synthetic fiber is a high-strength super fiber, and the monofilament yarn has a diameter of 15 to 30 μm.