JPH0637117B2 - Mesh cloth for imprint screen - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mesh fabric using a composite filament, which is suitable for a printing screen.

BACKGROUND ART As a woven fabric for a printing screen, a mesh woven fabric made of silk or stainless steel has been widely used. However, silk has problems in strength and dimensional stability, and stainless steel has problems in elastic recovery and instantaneousness. However, since both of them are expensive, mesh fabrics made of polyester or nylon are now often used.

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

a) White powder scum is easily generated during weaving to cause various troubles. b) Emulsion coatability is poor. c) In order to form a uniform film thickness, many overcoats are required by an artisan technique. , D) low productivity, e) poor adhesion between the mesh and the emulsion resin, and poor printing resistance.

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, but a problem such as a decrease in strength of the material occurs, and a sufficient effect is not obtained. In the present situation, it has not been obtained and no practical improvement has been made.

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

Japanese Patent Application Laid-Open No. 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 a conductive carbon black. It is characterized by using a thermoplastic synthetic polymer containing ## STR3 ## and no solution has been presented for improving the printing accuracy and printing resistance, which have been problems in the past.

OBJECT OF THE INVENTION The present invention uses composite filaments to provide dimensional stability,
An object of the present invention is to provide a mesh fabric for a printing screen, which has both adhesiveness with an emulsion resin and elastic recovery, that is, excellent printing accuracy and printing resistance.

Structure of the Invention The mesh fabric of the present invention is a mesh fabric using a composite filament, wherein the composite filament is a core-sheath composite filament having a core-sheath volume ratio of 1: 5 to 3: 1. Is made of polyamide and the core material is made of polyester or polyolefin, and the stress-strain curve is measured by setting the gripping interval to 20 cm by the labeled strip method as a test piece having a width of 5 cm. If the breaking elongation is 15-40%
And the breaking strength is 25 kgf or more and the elongation is 5% or more, the relation between the strength Y (kgf) and the elongation X (%) is Y ≧
It is characterized in that it is (X + 1) × 5/3.

That is, the present invention is a combination of different synthetic fiber materials,
By using it as a composite filament, the advantages of each material are effectively exhibited and the desired purpose is effectively achieved.

The polyester used as the core material of the composite filament is excellent in dimensional stability and elastic recovery, and guarantees the dimensional stability of the screen, and the polyamide used as the sheath material has good adhesiveness with resins etc. It is possible to prevent the generation of white powder scum during weaving, which is the next point of the screen, and to improve the strength of the screen, the coatability of the emulsion, the permeability of the ink, and the like.

Therefore, the mesh fabric of the present invention can be produced with high productivity, can always be manufactured in high quality, and can be stably used as a screen having excellent printing accuracy and printing resistance.

Further, the woven fabric of the present invention, by sufficiently selecting and using the composite filaments as described above, and by appropriately heat-setting as necessary, the relationship between the strength and elongation of the woven fabric can be specified as described above. By designing within the range, the workability in the screen tensioning process during screen manufacturing and the dimensional stability of the screen are significantly improved, and the high tension printing resistance of the plate in the printing process is also improved, making it suitable for precision printing. Is possible.

The strength-elongation relationship of the woven fabric according to the present invention is such that the rupture strength is remarkably larger than that of a normal synthetic fiber mesh woven fabric while having an appropriate rupture elongation that cannot be expected with stainless steel, and the stress-strain curve is 5%. Y at the above elongation
The curve is one in which the elongation is suppressed such that ≧ (X + 1) × 5/3 and the strength is superior. Therefore, it is possible to form a stable screen with extremely high tension and low elongation. is there. For example, a screen with a high tension, which is not possible with a conventional synthetic fiber mesh woven fabric, having a tension of 0.60 or less by a 75G type tension gauge manufactured by Sun Giken, can be manufactured with good workability.

In the present invention, the polyester and polyolefin constituting the core component need to have an appropriate viscosity at the spinning temperature determined in relation to the sheath component during spinning. For example, as the polyester, polyalkylene terephthalate, copolymer poly Alkyl terephthalate, poly [1,4
-Cyclohexanediol / terephthalate] and the like are used, but polyethylene terephthalate, polybutylene terephthalate and poly [1,1,2] are used in order to ensure dimensional stability in heat setting at the processing stage after weaving.
4-cyclohexanediol terephthalate] is preferable, and the use of polyethylene terephthalate, which is economically available, is most preferable. Further, as the polyolefin, polyethylene, polypropylene, polybutene-
1 or the like can be used, but polyethylene and polypropylene are preferable in terms of stability during spinning and easy handling.
It is particularly preferable to use polypropylene because the spinning temperature can be easily selected.

As the polyamide constituting the sheath component, nylon 6, nylon 66, nylon 610, nylon 12, aliphatic polyamide such as condensation polyamide of paraaminocyclohexylmethane and dodecanedioic acid, polyxylylene adipamide, polyhexamethylene. Although any aromatic polyamide such as phthalamide can be used, nylon 6 and nylon 66 are preferable because of ease of spinning and economy.

It is important that the form of the composite filament is such that the sheath component is present continuously over the entire circumference of the fiber cross section and the core component is not exposed. The shape of the cross section of the fiber may be an ordinary round cross section, and the arrangement and shape of the core components are not particularly limited, and any of single core, multicore, round cross section, irregular cross section, concentric and eccentric may be possible. However, in order to ensure dimensional stability, a concentric single core arrangement with a round cross section in which stress is not dispersed or a multi-core arrangement with a round cross section is preferable.

The volume ratio of the core component to the sheath component may be 1: 5 to 3: 1, but is preferably 1: 2 to 2: 1. If the amount of the sheath component is too small, the sheath coating becomes too thin, resulting in thickness unevenness during spinning, which makes the coating easier to tear,
An external stress may be applied during weaving, stretching, or printing to break the coating. On the other hand, if the core component is too small, these drawbacks do not occur, but the resistance to tensile stress becomes small, and the dimensional stability of the screen becomes poor.

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

In the weaving of the mesh fabric of the present invention, the composite filament is usually used as a drawn yarn, but its strength is 5.5 g in order to ensure dimensional stability as a screen.
/ D or more, residual elongation is 30 to 50%, boiling water shrinkage is 10%
The stretching ratio and heat setting temperature are preferably set at the time of stretching as described below. In particular, it is preferable to use 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.

Also, in general, the weave density of the fabric of the present invention is 10 to 600.
The number of lines / inch (that is, plain weave of 10 to 600 mesh) is used, but an appropriate weave density may be selected depending on the application as a screen, that is, the ink supply amount, the line width of a pattern, and the like. . Usually, it is preferably 100 to 350 lines / inch.

Raw weaving woven using composite filaments is 60-80
After washing with an aqueous solution of a nonionic or anionic surfactant at 0 ° C., it is heated to 100 to 190 ° C. and a tension of 100 to 250 kg is applied to set a predetermined thickness and mesh number.

After setting, the mesh fabric is washed and dried on the surface, and then subjected to the step of stretching the mesh fabric on the frame, but the fabric of the present invention is applied to any frame made of aluminum, iron, wood, or resin. Good.

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

On the other hand, the conventional nylon mesh fabric cannot be applied to precision printing because it does not change with time, and the polyester mesh fabric also has a change over time after being stretched.
I had to leave it for two hours or more.

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

The coating thickness of the emulsion on the mesh fabric varies depending on the intended use, but since the surface of the fabric of the present invention is covered with polyamide having good adhesiveness to the emulsion, compared to a conventional polyester screen. The emulsion coatability is remarkably excellent, and a resin layer having a uniform film thickness can be easily formed.

After coating the emulsion so as to have a predetermined film thickness, it is dried, exposed or heated to produce a screen plate in the usual manner, and the pattern printing differs depending on the emulsion to be used. Usually, a high-pressure mercury lamp, xenon lamp, etc. (about 4 kW) are used as the light source, and 1 to 1.5
Exposure is performed from a distance of about m for 2 to 5 minutes. The integrated light quantity at this time is 300 to 500 millijoules / cm ² .

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

Example 1. A circular concentric composite filament having a sheath of nylon 6 and a core of polyethylene terephthalate and a volume ratio of sheath to core of 1: 1 was used, and the spinning temperature was 285 ° C. and the winding speed was 1,000 m.
Produced at a draw ratio of 3.90,
Stretching was carried out at a stretching temperature of 84 ° C. and a stretching set temperature of 180 ° C. to obtain three types of composite filaments having fiber diameters of 48 μ, 40 μ and 34 μ.

Using these composite filaments, five kinds of mesh fabrics A1 to A5 shown in Table 1 were produced, heat set, and then tested for strength and 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.

The stress-strain curves for the mesh fabrics A1 to A5 and B1 to 5 in Table 1 and the conventional nylon mesh fabrics C1 to C5 are shown in FIGS. The test conditions are the same as above, and the materials and the number of meshes of the mesh fabrics C1 to C5 are as follows.

C1 50μ Nylon monofilament 150 mesh fabric C2 50μ Nylon monofilament 200 mesh fabric C3 39μ Nylon monofilament 250 mesh fabric C4 39μ Nylon monofilament 270 mesh fabric C5 39μ Nylon monofilament 300 mesh fabric Tables 1 and 1 As is clear from FIGS. 5 to 5, the woven fabrics A1 to A5 according to the present invention have an appropriate elongation and are significantly superior to the conventional screen materials B1 to B5 and C1 to C5. Indicates strength. Also, A1 according to the present invention
The stress-strain curve of the woven fabrics of A5 to A5 satisfies Y ≧ (X + 1) × 5/3 at an elongation of 5% or more, while the conventional screen materials B1 to B5 and C1 to C5 have low slopes. , Which is far below the range of the above formula.

Next, the fabrics A2, B2, A3, B3, A5, B5 of Table 1
Table 2 shows a comparison of white powder scum generation during weaving.

The woven fabrics A2 and B5 are 200-mesh fabrics woven at a warp count of 18,800 and a weft driving speed of 230 times / min. The woven fabrics A3 and B3 have a warp count of 23,500 and a weft driving speed of 230 times / min. The woven fabric is a 250 mesh woven fabric, and the woven fabrics A5 and B5 are 300 mesh woven fabrics having 28,200 warp yarns and a weft driving speed of 210 times / min.

All of the woven fabrics were woven using a sulzer loom while wiping the reeds with an air gun where scum was noticeable during weaving and dropping the scum.

From the results in Table 2, the fabrics A2, A3, A5 according to the present invention
It can be seen that is woven with very good quality with almost no white powder scum.

Example 2 Each of the mesh fabrics of Example 1 was heat-set, and then frame-clad in an aluminum frame with a gauze machine.

At this time, the compressor pressure of the gauze machine with the change in tension was measured, and at the same time, the mesh fabric was marked at 50 cm intervals in the longitudinal and transverse directions, and the elongation was measured during this time.

Table 3 shows the relationship between the tension, the compressor pressure of the stretcher, and the elongation of the mesh fabric. In addition, Table 4 shows the changes over time in the tension after the tensioning. In Tables 3 and 4, A2, A3, A5, B2, B3, B5, and C2 indicate the types of the mesh fabric of Example 1.

The equipment used for the test is as follows.

Tensioner: 3S air stretcher made by Mino Group Aluminum frame: 880mm x 880mm square frame width 40mm, thickness 25mm Tension meter: Sun Giken 75B type tension gauge From the results of Tables 3 and 4, it can be seen that the mesh fabrics (A2, A3, A5) according to the present invention have very good workability and can be stably stretched with high tension. On the other hand, normal polyester mesh fabrics (B2, B
In No. 3, B5), the elongation is accelerated at a high tension, and it is difficult to form a stable gauze, and the application of tension is limited. Furthermore, the polyester mesh woven fabric (B2) and the nylon mesh woven fabric (C2) both show remarkable changes in tension after the cloth is stretched. In particular, the nylon mesh fabric (C2) does not have stable tension even after one week has passed since it was stretched.

Example 3 The mesh fabric of the present invention was tested for frictional electrification voltage and its half-life and leakage resistance, and compared with the test results of a normal polyester mesh fabric, a low temperature plasma treated polyester mesh fabric and an antistatic treated polyester mesh fabric. did. The results are shown in Table 5.

The test method is as follows.

Friction electrification voltage: Measured by a Kyoto University chemical research type rotary stick tester (Koa Shokai).

Cloth to be rubbed Cotton wire width 3 Rotation speed 450 rpm Load 500 g Friction time 60 sec Leakage resistance value: SM-5 super insulation meter (Toa Denpa Kogyo)
At 20 ° C. and RH 40%, JISG-1026
Was measured according to.

From this result, the fabric of the present invention, as a screen without causing problems due to static electricity in the printing process,
It turns out that it can be used stably.

Example 4 Each mesh fabric shown in Table 1 of Example 1 was washed with 0.2% neutral detergent aqueous solution and dried, and then PVA-vinyl acetate photosensitive emulsion NK-14 (West Germany, Karley). Was applied, dried, and overcoated to give a film thickness of 10 to 12 μm.

Each of the mesh fabrics after forming the photosensitive coating film has the following 10
A grid pattern of varying size was printed in stages.

The baking was performed by using a 4 kw high-pressure mercury lamp and exposing at a distance of 1.5 m for 3 minutes. In this case, the integrated light quantity is 4
It was 00 millijoules / cm ² . Then, after immersing in water for 3 minutes, an unexposed portion was removed by water spray.

The tape peeling test was carried out on the mesh fabric on which the cross-cut pattern was baked in this manner, and the adhesive strength of the photosensitive coating film was measured.

Test Method The operation of sticking the Sumitomo 3M filament tape # 810 on the pattern of each mesh fabric and then peeling off the tape was repeated 3 times on the same surface, and the number of grids attached to the tape To record.

The results are shown in Table 6. In Table 6, the numerical value shown as 1 time is the number of crosses peeled off by the first tape application, and the numerical values shown as 2 times and 3 times were peeled off after the second and third tape application, respectively. It is the total number of squares on the grid.

Example 5 After each mesh fabric shown in Table 1 of Example 1 was heat-set, each E. P. C. Also, the elongation modulus was tested and compared with the test results of conventional polyester mesh fabrics. The results are shown in Tables 7 and 8.

E. P. C. Elastic Performance Coefficients are physical properties that take into account the recoverability of fibers after they are subjected to mechanical action.

The load-deformation relationship in the first cycle and the nth cycle is determined and shown as in FIG.

L _O : Initial load curve L _C : Conditioned load curve R _O : Initial recovery curve R _C : Conditioned recovery curve a _O : Initial load deformation a _C : Conde Deformation amount with respect to conditioning load at the time of conditioning _{AO and the} like with A indicate respective energy values.

AL _O ratio of AL _O is intended to indicate the degree of recovery when the con den partitioning, speed is a function of the primary creep.

Also, ao ² / AL _o represents a measure of energy absorption for all deformations for the first cycle, and aC ² / A
L _o is a measure of the energy absorption against deformation energy in the same manner conditioning cycle. For these ratios, considering the correction term of AR _o / AL _o ,
E. P. C. Is expressed by the following equation.

If recoverable: AR _o = AL _o , a _o = a _c ,
If AL _o = AL _c and AR _o = AR _e , then E. P.
C. = 1 In case of non-recovery: AR = 0, AR _c = AL _o , a _c = a
_o , E. P. C. = 0. (See "Textile Physics", pages 254-255, published by Maruzen Co., Ltd. on Mar. 10, 1969) Elongation elastic modulus According to JIS L1096.

Using a constant speed extension type tensile tester with an automatic recording device, the distance between grips is 20 cm, and the pulling speed is 10 gripping intervals per minute.
%, Stretch to constant load, then unload at same speed and stretch again to constant load at same speed.
The residual elongation is measured from the recorded load-elongation curve, and the elongation elastic modulus is calculated by the following formula.

L: elongation under constant load (mm) L _1: residual elongation under constant load (mm) Note, E. P. C. The measurement of elongation elastic modulus was performed under the following conditions.

Test method: JIS L1068-1964 Labeled strip method Tester: Constant speed tension type tester (S-500 type, Shimadzu Corporation) Test condition: 20 ° C, R.S. H. 65% test width 5cm, gripping interval 20cm, pulling speed 10cm / min. Cycle 20 times number of tests: 50 times From the results of Tables 7 and 8, the mesh fabrics (A1, A2, A3, A4, A5) according to the present invention have very excellent recoverability, and even if the load is large, a normal polyester mesh fabric (B1, B2, B3, B4, B5) are less changed, and the elastic recovery rate and the recoverability after being subjected to a mechanical action are good.

Due to this improvement in recoverability, the life of the plate having improved printing durability is remarkably extended.

Example 6 The mesh fabrics of Example 1 were heat-set, respectively, framed in an aluminum frame with a gauze machine, washed with water and dried, and then PVA-vinyl acetate photosensitive emulsion NK-14 ( (Germany, West Germany) was applied, dried, and overcoated to a film thickness of 12 μm, and the following two patterns were baked on each mesh fabric after the formation of the photosensitive film.

(I) A lattice pattern in which fine lines intersect at an interval of 150 mm in length and width.

(II) Thickness 50 μm, 60 μm, 80 μm, 100 μ
m, 125 μm, 150 μm, 200 μm, 250 μ
A test pattern of 2 groups in which 5 thin lines of m and 300 μm are arranged at equal intervals.

Look at the print misregistration when the pattern (I) is printed 1,000 times and 3,000 times, and see the reproducibility of the fine line in the pattern (II).

For baking, a 3KW metal halide lamp is used for 80
The exposure was performed at a distance of cm for 2 minutes. Then, after immersing in water for 3 minutes, an unexposed portion was removed by water spray.

In this way, the printing accuracy was measured by performing the print deviation test and the fine line reproducibility test on the mesh fabric on which the patterns (I) and (II) were baked. The results are shown in Table 9,
It shows in Table 10.

Plate-making conditions: Tension machine 3M air stretcher made by Mino Group (normal tension) Tension 1.00mm (stretching) Emulsion NK-14 (West Germany Karley) Thickness 12μ frame 880mm x 880mm (aluminum) Image 300mm x 300mm Squeegee Conditions: Type Urethane hardness 70 ° Angle 75 ° Width 405mm Printing conditions: Gap 3.0mm Printing pressure 1.5mm Ink UV ink 5104-T6 (Mitsui Toatsu) Ink viscosity 200 PS From the results of Tables 9 and 10, the mesh fabric used in the present invention (A
2, A3, A5) can be applied to high-density / high-precision printing excellent in printing accuracy and resolution of fine line printing.

On the other hand, normal polyester mesh fabric (B2
In B3 and B5), the resolution of fine line printing is poor, and the number decreases remarkably as the number of printing increases.

Example 7 Each mesh fabric printed on the surface of Example 6 3,000 times was printed with E. P. C. In addition, the elongation elastic modulus was used as a test and compared with the test result of a normal polyester mesh fabric. The results are shown in Tables 11 and 12. The test method is the same as in Example 5.

From the results of Tables 11 and 12, the mesh product according to the present invention (A2,
A3 and A5) have a very good EPC and elongation elastic modulus after printing, significantly improve printing accuracy and printing resistance, and can be applied to high density / high precision printing. .

On the other hand, in the normal polyester monofilament woven fabrics (B2, B3, B5), the printing resistance decreases as the number of printings increases. Further, although the ordinary nylon monofilament mesh fabric does not show the test result here, it has an elongation elastic modulus inferior to the polyester monofilament mesh fabric and is not suitable for high density / high precision printing.

EFFECTS OF THE INVENTION The mesh fabric of the present invention has excellent dimensional stability, high strength, and excellent adhesiveness with a resin, and thus enables production of a printing screen with good workability and accuracy. Further, since the mesh fabric of the present invention is excellent in antistatic property, it also remarkably enhances workability when used as a printing screen.

That is, the woven fabric of the present invention has good ink permeability, has very little change over time, and enables the production of a screen without deviation, which improves the workability of the printing process and significantly improves the printing resistance, A screen that can be stably used for precision printing of electronic components such as printed circuits, multilayer boards, and IC circuits can be mass-produced at low cost and with good workability.

[Brief description of drawings]

1 to 5 are graphs showing the stress-strain curves of the mesh fabric of the present invention and the conventional mesh fabric in comparison, and FIG. 6 is a graph showing the load-deformation relationship of the fibers.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takuo Mamoru, 11-42-1, Shimoarai-cho, Fukui-shi, Fukui Prefecture (72) Inventor Yoshinori Kato 52, 52, Komyoji Temple, Eiheiji-cho, Yoshida-gun, Fukui Prefecture Examiner Fukatsu Hiroshi (56 ) Reference JP 59-159349 (JP, A) JP 59-143688 (JP, A) JP 55-1337 (JP, A)

Claims (3)

[Claims] 1. A mesh fabric using a composite filament, wherein the composite filament is a core-sheath composite filament having a core-sheath volume ratio of 1: 5 to 3: 1, and a sheath material made of polyamide, When the core material is made of polyester or polyolefin, and when the above-mentioned woven fabric is used as a test piece with a width of 5 cm and the stress strain curve is measured by setting the gripping interval to 20 cm by the labeled strip method, the elongation at break Is 15 to 40%, 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) A mesh fabric for a printing screen, characterized by having a size of 5/3. 2. The mesh fabric according to claim 1, wherein the composite filament is a monofilament. 3. The mesh fabric according to claim 2, wherein the volume ratio of the core-sheath is 1: 2 to 2: 1.