JP2007092233A - Monofilament for screen gauze - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheath-core conjugate monofilament for a screen gauze, having excellent antihalation effect in the light exposure step in the case of processing to a mesh fabric for printing screen, exhibiting excellent dimensional stability and giving excellent printing accuracy. <P>SOLUTION: The sheath-core conjugate monofilament for screen gauze having a sheath-core conjugate structure has a reflectance of ≤5.0% to the light of 300-500 nm wavelength and an initial elastic modulus of 100-125 cN/dtex. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a core-sheath composite monofilament for printing screens. More specifically, the present invention relates to a core-sheath composite monofilament for screen wrinkles that is excellent in preventing halation in the photosensitive and exposure processes in the field of high-precision printing such as electronic circuit printing and also has dimensional stability.

  In recent high-precision printing fields such as electronic circuit printing, the demand for more precise printing accuracy has become increasingly severe. Usually, screen stencil making is made of monofilament made into a mesh fabric, then laid on a frame frame, coated with a photosensitive resin, dried, and a positive film is adhered to the surface. However, when this is washed with water, the unreacted photosensitive film corresponding to the opaque portion of the positive film is washed away, the screen is developed, and the ink is washed away from the texture to be printed. Follow the process.

  In the screen wrinkle manufacturing process, it is very important to control the UV exposure process. If the exposure amount is small, the photosensitive film will not be cured sufficiently and will fall off during development. There was a problem of getting worse and filling the texture. Further, there is a problem that so-called halation occurs, in which ultraviolet rays are irregularly reflected on the surface of the mesh fabric and are exposed to a portion that does not require exposure to be hardened. In order to prevent halation, there is a method of dyeing the mesh fabric in order to reduce the influence of ultraviolet rays, but the performance is not sufficient.

  In order to solve these problems, there has been proposed a mesh fabric for a printing screen comprising a monofilament in which polyamide, that is, nylon 6, nylon 66 or the like is used as a sheath component and a yellow pigment is mixed in the sheath component (Patent Document 1). However, when the sheath component of the monofilament composing the mesh fabric is polyamide, the monofilament has low breaking strength and lacks dimensional stability, and misalignment occurs during weaving, resulting in poor dimensional stability and printing accuracy. There was a problem of a drop In addition, when polyester is used as the core component and polyamide is used as the sheath component, there is a problem that a peeling phenomenon occurs at the composite interface, and the quality of the mesh fabric is lowered.

On the other hand, a monofilament for a screen having excellent dimensional stability and using a benzotriazole-based compound or a benzophenone-based compound as an ultraviolet absorber and having less ultraviolet reflection has been proposed (see Patent Document 2). When processed into a mesh fabric, the anti-halation effect at the time of exposure and exposure can be obtained, but the performance in the high-precision printing field is not sufficient, and the print pattern baked on the screen causes blurring and fogging. was there.
Japanese Patent Laid-Open No. 01-47591 (2nd item, left column, line 18 to right column, line 14) Japanese Unexamined Patent Application Publication No. 2004-262007 (2nd term, 25th line to 3rd term, 5th line)

  The present invention solves the above problems, and when processing into a mesh fabric for printing screens, it is excellent in preventing halation in the photosensitive and exposure processes, has good dimensional stability, and has excellent printing accuracy. Is to provide.

In order to solve the above problems, the present invention employs the following configuration. That is,
(1) In a screen filament monofilament in which the composite form forms a core-sheath structure, the reflectance with respect to light having a wavelength of 300 to 500 nm is 5.0% or less, and the initial elastic modulus is 100 to 125 cN / dtex. A core-sheath composite monofilament for screen cocoons.
(2) The core-sheath composite monofilament for screen wrinkles according to the above (1), wherein any component of the core-sheath is made of polyester and the sheath component contains an organic pigment.
(3) The core-sheath composite monofilament for screen wrinkles according to (1) or (2), wherein the organic pigment is anthraquinone.
(4) The composite ratio of the core-sheath component is 70:30 to 90:10 in volume ratio, and the breaking strength is 5.9 to 7.0 cN / dtex, (1) to (3) A core-sheath composite monofilament for a screen cage according to any one of the above.

  The core-sheath composite monofilament for screen cocoons in the present invention is highly accurate in the field of high-precision printing and printing because it is excellent in preventing halation in the photosensitive and exposure processes, has good dimensional stability, and has excellent printing accuracy. It is a suitable material for printing printing screen silk thread.

  Hereinafter, the present invention will be described in detail.

  The core-sheath composite monofilament of the present invention has a reflectance of 5.0% or less with respect to light having a wavelength having a peak at 300 to 500 nm by a photolithography method. If the reflectance exceeds 10%, a sufficient anti-halation effect cannot be obtained in the high-precision print printing field. Therefore, the reflectance is preferably as close to 0% as possible.

The core-sheath composite monofilament of the present invention is a high-strength monofilament suitable for high-precision print printing, and the initial elastic modulus is 100 in order to suppress the occurrence of deterioration in weaving property and wrinkle elongation and maintain high dimensional stability. ~ 125 cN / dtex. Here, the initial elastic modulus is a point A corresponding to a linear relationship up to the first yield point Y1 after performing a tensile test on a monofilament having an initial length of 20 cm at a strain rate of 100% / min to obtain the SS curve of FIG. And the slope of the point B are calculated by the following method.
Initial elastic modulus (cN / dtex) =
(Intensity at point A−Intensity at point B) / {(Elongation at point A−Elongation at point B) / 100}
When the initial elastic modulus is less than 100 cN / dtex, necessary and sufficient dimensional stability cannot be obtained, and printing accuracy is lowered. On the other hand, if the initial elastic modulus exceeds 125 cN / dtex, scraping and scum are likely to occur in the warping and weaving process in the manufacture of the mesh fabric, and the quality of the mesh fabric is lowered. More preferably, it is 100-120 cN / dtex.

  The core and sheath component of the core-sheath composite monofilament used in the present invention is preferably made of polyester. The polyester constituting the core and the sheath component is obtained by polymerizing ethylene glycol, which is generally used, with terephthalic acid in order to ensure dimensional stability in heat setting in the processing stage after weaving the monofilament, It is preferable to use polyethylene terephthalate to which 0.1 to 0.5% by weight of titanium oxide is added as an additive, and ethylene terephthalate having a titanium oxide addition amount of 0.2 to 0.4% by weight is particularly preferable.

  In order to impart an antihalation effect to the core-sheath composite monofilament of the present invention, it is preferable that the sheath component polyester forming the core-sheath composite is mixed with an organic pigment and colored with a stock solution. In this method, it is not necessary to dye after the production of the mesh fabric only by mixing the pigment into the sheath component of the composite core-sheath monofilament, and a stable antihalation effect can be obtained. Further, since the screen plate can be produced without any foreign matter adhering to the fiber surface or heat shrinkage of the mesh fabric, a high-density and fine pattern can be produced with high accuracy on the screen plate.

  The organic pigment used in the present invention has a low reflectance with respect to light having a wavelength of 300 to 500 nm, is colored as a uniform solution as much as possible, and passes through a monofilament processing step without being cut off, for example, a yellow pigment such as Color. Index Y193, anthraquinone yellow shown in Chemical Substances Control Law Chemical Number (5) -1259, and the like are preferable. Moreover, the pigment concentration mixed in the sheath component polyester forming the core / sheath composite is preferably 4 to 15% in order to maintain appropriate viscosity during melt spinning and to uniformly knead the pigment.

  In the present invention, the method of mixing the pigment into the polyester of the sheath component is not particularly specified, but the method of kneading with the base polymer in a pellet state using a blender and then melting, or the polyester of the sheath component In order to obtain uniform kneading properties, it is preferable to melt the pigments and to knead them by passing them through a kneading machine in the molten polymer state.

  In the present invention, the ratio of the core component to the sheath component forming the core / sheath structure of the core / sheath composite monofilament is preferably 70:30 to 90:10, and particularly preferably 75:25 to 85:15. If the sheath component is too small, the sheath coating becomes too thin, and thickness unevenness is likely to occur during spinning, or the coating may be easily broken due to external stress during weaving, tensioning, or printing. is there. On the other hand, if the core component is too small, these defects do not occur, but the resistance to tensile stress becomes small and the dimensional stability as a screen is lacking.

  In the form of the core-sheath composite monofilament in the present invention, 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 a normal round cross-sectional shape, and the arrangement and shape of the core component are not particularly limited, and any of single-core, multi-core, atypical cross-section, concentricity, and eccentricity is possible. However, in order to guarantee 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 core-sheath composite monofilament of the present invention is a high-strength monofilament suitable for high-precision print printing, and has a breaking strength of 5.9 in order to suppress the occurrence of deterioration in weaving properties, wrinkle elongation, etc., and maintain high dimensional stability. Those of ˜7.0 cN / dtex are preferred.

  If the fineness of the core-sheath composite monofilament of the present invention is in the range of 8.0 to 18 dtex, the effects of the present invention excellent in dimensional stability and printing accuracy can be obtained to the maximum in the high-precision printing field.

  The core-sheath composite monofilament in the present invention is melt-spun with a spinning member having an orifice hole that forms a core-sheath composite at 290 ° C. in a spinning machine having two or more melting parts, cooled and solidified, and then lubricated. And take up once at a take-up speed of 1000 m / min. It is obtained by drawing the wound undrawn yarn with a hot roller drawing machine at a preheating temperature of 90 ° C. and a draw ratio of 4.0 times, and then heat setting at a temperature of 130 ° C. and winding up 900 m / min.

Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples. In addition, each characteristic value in an Example was measured using the following method.
1. Reflectance (%)
For mesh fabrics of warp and weft density 350 mesh (350 pieces / 2.54 cm) obtained from core-sheath composite monofilament, reflectivity (%) was measured by the method described in JISZ8722 (color measurement method-reflection and transmission object color). It was measured.
2. Initial elastic modulus (cN / dtex)
Using a Tensilon tensile tester manufactured by Orientex Corp., a tensile test was conducted until the specimen broke with an initial sample length of 20 cm, a strain rate of 100% / min, and an initial load of 1/30 cN / dtex, and the initial elastic modulus was calculated by the method described above. .
3. Breaking strength (cN / dtex)
Using a Tensilon tensile tester manufactured by Orientex Co., Ltd., a tensile test was performed until the sample broke with an initial sample length of 20 cm, a strain rate of 100% / min, and an initial load of 1/30 cN / dtex, and the strength at the time of breaking was obtained.
4). Anti-Halation Effect A fine pattern was baked on a mesh fabric having a warp and latitude density of 350 mesh (350 pieces / 2.54 cm) obtained from a core-sheath composite monofilament and observed with an electron microscope.
◎… Halation prevention effect is great.
○ ... Halation prevention effect.
Δ: Little antihalation effect.
× ... Halation occurred.
6). Fine pattern baking state on mesh fabric A fine pattern was baked on a mesh fabric of warp and weft density 350 mesh (350 pieces / 2.54 cm) obtained from the core-sheath composite monofilament and observed with an electron microscope.
A: Good adhesion and clearer pattern.
○: Good adhesion and good pattern edge.
Δ: Adhesive strength is inferior and pattern edges are poor.
X: No adhesive force and no pattern is formed.

Example 1
A polyethylene yellow terephthalate having an intrinsic viscosity (η) of 0.50 as a sheath and a polyethylene terephthalate having an intrinsic viscosity (η) of 0.80 as a core. (C.I.PIG Yellow No. 193) was added and produced at a spinning temperature of 290 ° C. and a winding speed of 1000 m / min so that a composite ratio of core: sheath was 80:20 in volume ratio. The filament was stretched at a stretch ratio of 4.4 times, a stretching temperature of 91 ° C., and a heat setting temperature of 130 ° C. to obtain a core-sheath composite monofilament having a fineness of 13 dtex.

  The obtained core-sheath composite monofilament was placed on a slewer type loom to weave a mesh fabric at a warp / wet density of 350 mesh (350 pieces / 2.54 cm) and a rotational speed of 250 rpm, and then the reflectance was measured. Thereafter, the fine pattern was baked and observed with a microscope.

  The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 4.5%. In addition, the effect of preventing halation was high, and the adhesion of fine patterns was good and clear. The initial elastic modulus was 110 cN / dtex and the breaking strength was 6.0 cN / dtex, and a level with no problem in practical use was obtained.

Example 2
It implemented by the method similar to Example 1 except having changed the composite ratio of the core: sheath to 70:30.

  The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 3.0%. Further, the effect of preventing halation was high, the adhesive force of the fine pattern was good, and it was as clear as in Example 1. The initial elastic modulus was 100 cN / dtex and the breaking strength was 5.9 cN / dtex, and a level with no problem in practical use was obtained.

Example 3
The same procedure as in Example 1 was performed except that the core: sheath composite ratio was changed to 90:10.

  The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 5.0%. Further, the effect of preventing halation was high, the adhesive force of the fine pattern was good, and it was as clear as in Examples 1 and 2. The initial elastic modulus was 118 and the breaking strength was 6.2 cN / dtex, and a level with no problem in practical use was obtained.

Example 4
It implemented by the method similar to Example 1 except having changed the draw ratio to 4.6 times.

  The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 4.8%. Moreover, the halation prevention effect was high, the adhesive force of the fine pattern was good, and it was as clear as in Examples 1 to 3. The initial elastic modulus was 125 cN / dtex and the breaking strength was 7.0 cN / dtex, and a level with no problem in practical use was obtained.

Comparative Example 1
The same procedure as in Example 1 was performed except that nylon 6 was used as the sheath component, the spinning temperature was 290 ° C., the stretching temperature was 85 ° C., and the stretching heat setting temperature was 180 ° C.

  The reflectivity of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 4.5%, but the initial elastic modulus was 90 cN / dtex and the breaking strength was 5.7 cN / dtex. The required strength is not obtained, the dimensional stability is poor, and further, interfacial peeling occurs in the warping and weaving process, scum occurs frequently, clogging of the mesh fabric occurs, and the antihalation effect is obtained, but the fine pattern The adhesive strength was poor and a clear pattern could not be obtained.

Comparative Example 2
As the sheath component, a copolymer polyester obtained by copolymerizing 4.8% by weight of polyethylene glycol having an average molecular weight of 600 in the polyester was used as the sheath component, and the same procedure as in Example 1 was performed except that benzotriazole was used as the pigment. did.

  The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 10.0%. The initial elastic modulus was 92 cN / dtex and the breaking strength was 5.7 cN / dtex, and the strength required for actual use was not obtained, and the dimensional stability was poor. Further, the effect of preventing halation was not obtained so much, the adhesive force of the fine pattern was poor, and a clear pattern could not be obtained.

Comparative Example 3
It implemented like Example 1 except having made the draw ratio into 4.8 times.

  The reflectivity of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 4.7%, but the initial elastic modulus was high at 130 cN / dtex and the breaking strength was 7.5 cN / dtex. Scraping occurred during the production, and the scum was clogged with the mesh fabric, and although an antihalation effect was obtained, the adhesive force of the fine pattern was poor and a clear pattern could not be obtained.

Comparative Example 4
An organic pigment is not kneaded into a white core-sheath composite monofilament, and the mesh fabric obtained in the weaving process is washed with 0.2% neutral detergent and dried, and then PVA-vinyl acetate photosensitive resin NK. -14 (manufactured by Hoechst) was applied and dried, and was carried out in the same manner as in Example 1 except that the film thickness was changed to 10 to 12 μm by repeated coating.

  The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 9.5%. The initial elastic modulus was 110 cN / dtex and the breaking strength was high at 6.0 cN / dtex, and because of the influence of thread shaving in the warping and weaving process, very little powdery dirt was woven into the mesh fabric. When the photosensitive resin NK-14 was applied, the film thickness varied, the fine pattern adhesive strength and sharpness were slightly inferior, and the antihalation effect was not seen so much.

Comparative Example 5
It implemented by the method similar to Example 1 except having made the core-sheath compound ratio 60:40.

  The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 5.0%. The initial elastic modulus was 85 cN / dtex and the strength was 5.5 cN / dtex, and the strength required to maintain dimensional stability could not be obtained. In the weaving process, thread shaving is likely to occur, and because of the influence of thread shaving, a very slight amount of powdery dirt was woven into the mesh fabric, so although the adhesive strength and sharpness of the fine pattern were inferior, halation prevention The effect was seen.

Comparative Example 6
It implemented by the method similar to Example 1 except having made the core-sheath compound ratio 95: 5. The reflectance of the mesh fabric obtained by warping and weaving the obtained core-sheath composite monofilament was 7.0%. The initial elastic modulus was 110 cN / dtex and the strength was 6.0 cN / dtex, and the strength required to maintain dimensional stability was obtained, but the weight distribution of the sheath component containing the organic pigment was small, and warping / Since the interfacial peeling of the core-sheath component occurred in the weaving process, the anti-halation effect was not satisfactory because the whisker-like dirt was woven into the mesh fabric, and the adhesion and sharpness of the fine pattern were inferior. It was a thing.

  The results are summarized in Table 1.

SS curve diagram explaining how to calculate the initial elastic modulus

Explanation of symbols

Y1: First yield point

Claims (4)

  In a monofilament for a screen cage in which the composite form forms a core-sheath structure, the reflectance for light with a wavelength of 300 to 500 nm is 5.0% or less and the initial elastic modulus is 100 to 125 cN / dtex. Sheath composite monofilament.   The core-sheath composite monofilament for a screen bag according to claim 1, wherein any of the core-sheath components is made of polyester, and the sheath component contains an organic pigment.   The core-sheath composite monofilament for a screen bag according to claim 1 or 2, wherein the organic pigment is anthraquinone.   The core / sheath core sheath according to any one of claims 1 to 3, wherein the composite ratio of the core / sheath component is 70:30 to 90:10 by volume, and the breaking strength is 5.9 to 7.0 cN / dtex. Composite monofilament.

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