JP3166381B2 - 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 screen gauze for printing. More specifically, the present invention relates to a printing screen gauze that realizes a high opening area in a high mesh screen gauze made of fine filaments and has good dimensional stability.

[0002]

2. Description of the Related Art Polyester monofilaments as a material constituting a screen gauze for printing have a high elastic modulus and excellent dimensional stability, and thus have been frequently used for precision printing of electronic circuits and the like. In order to realize such high-precision printing, generally, the weave density of the screen gauze is increased to create a finer line pattern. In this simple method of increasing the weaving density,
Since the number of openings of the woven fabric, that is, the opening area, is reduced, the ink passing property is reduced, and the printing accuracy is rather reduced.

[0003] On the other hand, it is possible to weave a woven fabric having a large opening area using fine fine yarn, but there are the following problems in addition to the difficulty in producing fine fine monofilaments. A screen gauze with good dimensional stability could not be obtained. In other words, when trying to obtain a woven fabric with a large opening area from the design stage during weaving, warp yarn,
Both weft yarns are liable to be misaligned, and it is difficult to form a uniform opening fabric.

Japanese Utility Model Publication No. 41-20626 discloses a method of increasing the number of meshes of a screen gauze by heat shrinkage and then hydrolyzing the fiber surface with an alkaline solution to increase the opening area. I have.
However, in this method, it is essential to perform a heat shrink treatment prior to the weight reduction treatment, and this is an effective means for increasing the weaving density. However, as clearly shown in FIG. 2 of the publication, There is a fatal drawback that the fibers meander during the shrinking process and the mesh structure becomes uneven. Further, since the weight loss rate is easily influenced by the concentration, temperature and treatment time of the alkaline solvent, it is difficult to keep the weight loss rate constant and there is a problem that reproducibility is poor. Also, because the strength of the screen gauze is greatly reduced by the weight loss process,
In addition to the fact that high tension gauging cannot be performed, the fiber structure becomes loose, so that the stress relaxation of the screen plate becomes large and the dimensional accuracy is inferior, so that it is not suitable for high precision printing.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the drawbacks of the prior art and to provide a high-measurement screen gauze for high-precision printing which has a high mesh, a large opening area, and excellent ink permeability. I do.

[0006]

An object of the present invention is to provide a polyester component having a higher dissolution rate in an alkaline solvent as a sheath component and a polyester component having a lower dissolution rate than the sheath component as a core component. After setting a plain weave screen gauze made of a core-sheath type composite monofilament on a greige machine, the screen gauze for printing, in which the sheath component is substantially dissolved and removed with an alkaline solvent, has a single yarn fineness of 7 d or less and a weave density of 300.
It can be achieved by a printing screen gauze characterized by having a mesh size or more, an opening area of 35% or more, and a breaking strength of 25 kg / 5 cm or more.

The woven density of the screen gauze of the present invention is 300
It is mesh or more, more preferably 350 mesh or more. The present invention is intended for precision printing in screen printing, for example, in order to accurately print fine lines with a line width of 150 μm or less in electronic circuit printing,
It is necessary to make the screen plate a high mesh screen with a weave density of 300 mesh or more.

In the screen gauze of the present invention, the opening area% after substantially removing the sheath component with an alkaline solvent is 35% or more, more preferably 40% or more. By setting the opening area% to 35% or more, a high-mesh screen of 300 mesh or more can make the printing ink having a viscosity of 150 poise or more pass well through the plate.

Here, the opening area% is "New Screen Printing Technology and Its High Accuracy / Various Trouble-Solving Techniques-Comprehensive Technical Data Book" published by Soft Giken Publishing Department (published October 6, 1986). -The porosity described on page 339. The viscosity of the printing ink is a viscosity measured at 25 ° C. using a Visco tester (VT-04).

The monofilament fineness of the monofilament constituting the screen gauze of the present invention is 7 denier or less, more preferably 6 denier or less. Here, the single yarn fineness means the fineness of the core component after the sheath component has been substantially dissolved and removed with an alkaline solvent described later.

A screen gauze having a single yarn fineness of 7 deniers or less has a low yarn strength and is liable to be broken at the time of weaving in a high-density woven fabric under severer weaving conditions. Due to the large damage to the fiber surface, it was difficult to obtain high quality gauze. For the first time, the screen gauze of the present invention has achieved a very good quality screen gauze at a fineness of 7 denier or less.

In order to obtain a screen gauze having a large opening area, it is generally sufficient to set the weaving density of the warp yarn and the weft yarn to be coarse. However, in the case of a woven fabric having a fineness of 7 denier or less as the object of the present invention, if weaving is performed at a coarse weaving density from the beginning, misalignment is likely to occur during weaving or during handling in the finishing process, and the yarn meanders. It is difficult to obtain one having uniform opening and good dimensional stability.

According to the present invention, during weaving, it is possible to close the eyes in a state of large fineness and weave it. After fixing the position by the greige set, the fineness is reduced by alkali dissolution treatment, and the opening area is adjusted to a desired size. Because it can be spread out quickly, a screen gauze with a uniform opening can be obtained.

Further, in the present invention, since the fineness is large during the handling of the monofilament from the production of the raw yarn to the weaving, troubles such as yarn breakage due to excessive tension and abrasion can be prevented, and operability is good. In addition, it is possible to obtain a high quality screen gauze.

The breaking strength of the screen gauze of the present invention is 25
Kg / 5cm or more, more preferably 30Kg / 5
cm or more. The breaking strength of screen gauze is 25kg
By setting the size larger than / 5 cm, the screen can be stuck to the gauze frame with a sufficient tension when the gauze is stretched. Therefore, a screen gauze having good dimensional stability at the time of printing and good separation of the plate due to the viscosity of the ink can be obtained. .

The woven structure of the screen gauze is preferably a plain weave in order to prevent misalignment. In particular, when the opening area% exceeds 45%, it is necessary to use a plain weave to effectively exhibit the fixing effect of the greige set.

The screen gauze of the present invention is capable of selectively dissolving and removing a certain amount of the sheath component, so that a uniform weight reduction treatment can be performed, and the damage of the core component polyester after the weight reduction treatment can be reduced. The weight reduction rate can be set by the high ratio and the composite ratio, and the screen gauze can be designed to have a desired opening area.
Furthermore, even if there is a film-like or lint-like scum generated during weaving and woven into the screen gauze, it can be completely removed.

Next, the effects of the present invention will be described with reference to the drawings.
The broken line in FIG. 1 is a weight loss curve of the core component (A), and the solid line is a weight loss curve of the sheath component (B). In the screen gauze made of the core-sheath composite yarn of the present invention, for example, a weight loss process such as 0ab can be taken, so that the sheath component (B) can be weight-removed and removed in a short time, and the sheath component (B). After the point "a" is removed, the core component (A) has a slow weight loss rate, so that an extremely uniform weight loss rate can be obtained. Further, in the present invention, the strength of the composite monofilament,
Since the core component (A) is mainly responsible for the elastic modulus, dimensional stability, etc., the reduction in mechanical properties is small and uniform even when the sheath component is removed by weight reduction.

In the present invention, the sheath component polyester is quickly reduced in the weight reduction treatment, but the core component polyester is hardly reduced. Therefore, the sheath component can be uniformly and quickly reduced in weight without causing significant damage to the core component polyester due to weight loss. For this reason, the mechanical characteristics of the screen gauze after the weight reduction treatment are sufficiently maintained, and a screen gauze with excellent quality without breakage at the time of gauging can be obtained. Here, the weight reduction ratio of the core component and the sheath component depends on the weight reduction conditions, but the core component is adjusted to be at least 1: 2, preferably at least 1: 4 by weight reduction treatment with 98% C. 3% caustic soda solution. And the polymer of the sheath component.

The weight reduction treatment in the present invention mainly aims at removing the monofilament sheath component, and it is preferable that the weight reduction does not reach the core component. When the weight is reduced to the core component, the uniformity of the weight loss rate is impaired. In addition, the strength retention of the screen gauze decreases. The screen gauze of the present invention is characterized in that the substantial weight loss rate can be set by the compounding ratio of the sheath component, so that the unevenness of the weight loss rate can be extremely small.

Further, in the present invention, it is desirable that the core component is not damaged by the weight reduction treatment. When the core component is damaged, the strength of the screen gauze decreases.
In order to suppress such a decrease in strength, it is desirable to leave at least 5% by weight of the sheath component when the sheath component polyester is substantially removed by weight reduction treatment.
More preferably, 0.5 to 4% by weight is left. This is because, in the weight reduction treatment of the high mesh screen gauze of the present invention, the surface portion of the screen gauze is most easily reduced, and then the opening portion is easily reduced, but within the texture point where the warp and the weft are in contact with each other. This is because the sheath component of the contact portion is difficult to be reduced in weight.When the sheath component of the tissue point inscribed portion is dissolved and removed by a weight reduction treatment, the core component polyester is removed on the screen gauze surface portion where the sheath component has already been dissolved and removed. Will be damaged, and the strength of the scoon gauze will accelerate. On the other hand, if the sheath component is left in an amount of 5% by weight or more in the weight reduction treatment, the sheath component will also remain in the screen gauze opening portion, making it difficult to obtain a uniform opening. Furthermore, the stiffener also exists on the surface of the screen gauze, and when rubbed with a squeegee or the like at the time of printing, the sheath component remaining on the sladam peels off and causes clogging of the opening.

The composite ratio of the sheath component is not particularly limited, but is preferably 5 to 60%. More preferably, it is 10 to 50%. If it is less than 5%, it is difficult to obtain an ink having an opening area of 35% or more and it is difficult to improve the ink passage property. If it is 60% or more, the opening area becomes large and the ink permeability is remarkably improved. It is not preferable because misalignment is likely to occur at the organization point where the image is formed.

In the present invention, the alkaline solvent is a solvent mainly composed of caustic soda, and at least 50% by weight of the solute component is caustic soda. In addition, organic solvents such as caustic potash, other inorganic alkali compounds, and quaternary ammonium salts are used. Alkaline salts may be contained, and those obtained by dissolving those solutes in water can be suitably used.

In the present invention, the concentration, temperature and the like in the weight reduction treatment with an alkaline solvent are not particularly limited, but the alkali concentration is usually about 3%, and the range of the treatment temperature from 98 ° C. to the boiling point is preferable for production control. . As the core component polyester of the present invention, polyethylene terephthalate, polyethylene-2,6-naphthalate and the like are preferably used because they can have high strength and high elastic modulus and are excellent in dimensional stability.

In the composite monofilament of the present invention, its mechanical properties such as strength and elastic modulus are controlled by the core component. Therefore, it is preferable that the molecular weight of the polymer of the core component is as high as possible. For example, in the case of polyethylene terephthalate, the intrinsic viscosity is preferably 0.7 or more. By doing so, a core-sheath composite monofilament having a strength of 5.5 g / d or more can be obtained, and a high-mesh fabric can be produced from the beginning without impairing the operability in the weaving process, and the screen gauze shrinks. A high mesh can be achieved without causing the mesh to be formed. Therefore, a screen gauze having a uniform weave density can be obtained.

Examples of the sheath component polyester of the present invention include modified polyethylene terephthalate. By using modified polyethylene terephthalate, the symmetry of the molecular chain is disturbed and the fiber structure becomes loose, and the rate of weight loss can be increased up to about 100 times compared with homopolyethylene terephthalate by treatment with caustic soda or the like. As such modified polyethylene terephthalate, for example, when polymerizing polyethylene terephthalate, isophthalic acid, adipic acid, dimeric acid, dicarboxylic acids such as 5-sodium sulfoisophthalate, diethylene glycol, low molecular weight glycols such as butanediol, polyethylene glycol And one or more third components such as polyalkylene glycols such as polytetramethylene glycol, etc., and are copolymerized. The amount of the third component is not particularly limited, but may be selected so that the alkali dissolution rate becomes a desired value. In addition, polyethylene-
When 2,6-naphthalate is used, polyethylene terephthalate can be used as a sheath.

[0027]

【Example】

Examples 1 to 3 and Comparative Examples 1 and 2 Polyethylene terephthalate (A) having an intrinsic viscosity [η] of 0.80 was prepared as a core component of a composite monofilament. On the other hand, polyethylene glycol having a molecular weight of 1,000 was used as a sheath component during polymerization of polyethylene terephthalate.
A polymer (B) having an intrinsic viscosity [η] of 0.70 added by weight% was prepared. Using the above-mentioned polymer, concentric circular composite monofilaments having different composite ratios, with A as a core and B as a sheath, were spun at 1000 m / min at a spinning temperature of 298 ° C. according to a conventionally known composite spinning method. The obtained undrawn polyester monofilament is heated at 90 ° C and 140 ° C.
Using a pair of hot rolls heated to ℃, it was stretched 4.4 times to obtain a stretched monofilament having a fineness of 7 denier. Table 1 shows the composite ratio and yarn properties of the drawn monofilament. The measurement conditions for strength, elongation, and Young's modulus were a test length of 20 cm and a tensile speed of 2 using a Tensilon-type constant-speed tensile tester.
It was determined from the average value of 20 SS curves measured at 0 cm / min.

[0028]

[Table 1] Even with the use of the monofilament, weaving was carried out with a weaving length of 500 m using a sulzer loom, and the weavability was evaluated from the scum adhesion to the wings and the breakage of the warp or weft yarn. Then
By scouring and setting a greige machine according to a conventional method, a plain weave high mesh gauze of 420 mesh was obtained. The opening area of this gauze was 31.5%. FIG. 1 shows the relationship between the weight loss time and the weight loss rate when the mesh gauze was heated at a bath temperature of 98 ° C. and a 3% caustic soda solution at a bath ratio of 1:50 using a beam dyeing machine. Based on the results shown in FIG. 1, the screen gauze was subjected to weight reduction by the above-described method, and after washing with water, a finish setting was performed at 180 ° C. by a conventional method to prevent misalignment. Table 2 shows the weaving properties, the weight loss treatment conditions, and the strength retention after the finish setting. Here, the strength retention rate indicates the retention rate of the screen gauze breaking strength after the weight loss treatment with respect to the screen gauze breaking strength before the weight reduction treatment, and a test length of 20 cm, a sample width of 5 cm, and a tensilon type constant speed tensile tester. It was determined from the average value of five SS curves measured at a tensile speed of 20 cm / min.

Next, a gauze frame is stretched with a high tension at an angle of 22.5 degrees, and an ultraviolet-curing masking resin of a polyvinyl alcohol and polyvinyl acetate system is applied to the gauze frame.
A thin plate pattern having a line width of 0.07 mm and a length of 80 mm was exposed and baked in a square of mx100 mm in the running direction of the squeegee so as to have 300 lines at equal intervals, and washed with water to form a screen plate. Using the screen plate, an ultraviolet-curable etching resist ink AS-400 (viscosity: 160 PS / 25 ° C.) manufactured by Taiyo Ink Mfg. Co., Ltd. was used as a printing ink, and after printing was repeated 1,000 times on paper, a thin copper line pattern was formed. Was printed. Subsequently, the copper thin film was irradiated with ultraviolet rays to cure the ink, and then all the blurred portions and broken portions of the fine ink lines were counted at an optical microscope magnification of 50 times. The results are shown in Table 3.

[0030]

[Table 2]

[Table 3] As is clear from the results of Tables 1, 2 and 3, the screen gauze made of each of the monofilaments of Examples 1, 2, and 3 of the present invention has good weaving properties, and the weight reduction treatment with caustic soda is also effective. The screen gauze is uniform, and therefore has a high strength retention rate even when the weight loss rate is increased, has excellent ink permeability, and has very few printing defects even in fine line printing with a line width of 0.07 mm. Was. Comparative Example 1 has high strength and high Young's modulus yarn properties, but when weaving into screen gauze, scum in the form of film or lint due to scraping is remarkable, and warp yarn breakage occurs in part. There was a problem. Further, in the weight reduction process using caustic soda, there are problems that the weight reduction speed is slow, the weight reduction process requires a long time, and the strength retention rate by the weight reduction process is small. Furthermore, the ink passage property was such that both the blurred portion and the broken portion of the printed fine line were present, and had a printing defect. Further, the screen gauze of Comparative Example 2 had a problem that the strength was greatly reduced due to the caustic soda treatment, and thus the yarn was easily broken during printing.

Comparative Example 3 In Example 1, the screen gauze was further reduced with caustic soda to reduce the weight reduction rate to 36%. The breaking strength of the screen gauze after the weight reduction treatment was 20 kg / 5 cm and the strength retention was 53%. Thus, there is a drawback in that it is difficult to spread the gauze with high tension and the screen plate has a large dimensional error during printing.

Example 4, Comparative Example 4 A drawn monofilament having a fineness of 12 denier was obtained under the same spinning conditions as in Example 1. Table 4 shows the composite ratio and yarn properties of the drawn monofilament.

Even when the monofilament was used, a weaving length of 500 m was woven by a Sulzer loom, and the weaving property was evaluated from the scum adhesion to the wings and the breakage of the warp or weft yarn. Next, scouring and greige setting are performed according to the standard method.
A plain mesh high mesh gauze of 0 mesh was used. The opening area of this gauze was 33%. The mesh gauze was adjusted to a bath ratio of 1:50 with a 3% caustic soda solution at a bath temperature of 98 ° C. using a beam dyeing machine, and the sheath component was dissolved and removed. Then, the screen gauze was washed with water and subjected to a finishing set at 180 ° C. in a conventional manner to prevent misalignment. Table 5 shows the weaving properties, the weight loss treatment conditions, and the strength retention after the finish setting.

[0034]

[Table 4]

[Table 5] Next, a gauze frame is stretched with a high tension at a 22.5 degree angle, and a UV curable masking resin of polyvinyl alcohol and polyvinyl acetate is applied, and 100 mm × 100 m.
line width 0.15m in the squeegee running direction
Exposure baking was carried out so that 300 lines each having a length of 80 mm and a length of 80 mm were formed at equal intervals, and washed with water to form a screen plate. Using the screen plate, Taiyo Ink Manufacturing Co., Ltd.
UV curable etching resist ink AS550
(Viscosity 220PS / 25 ° C) as printing ink and 1 on paper
After repeating printing 000 times, a thin line pattern was printed on copper thin. Subsequently, the copper thin film was irradiated with ultraviolet rays to cure the ink, and then all the blurred portions and broken portions of the fine ink lines were counted at an optical microscope magnification of 50 times. The results are shown in Table 6.

[0035]

[Table 6] As is clear from the results in Tables 4, 5 and 6, the screen gauze made of the monofilament of Example 4 of the present invention has good weaving properties, and the weight loss treatment with caustic soda is uniform. The screen gauze had a high strength retention rate even when the value was increased, had excellent ink permeability, and had very few printing defects even in fine line printing with a line width of 0.15 mm. Comparative Example 4 has high strength and high Young's modulus yarn properties, but when weaving into screen gauze, film scraps or thread scraps are significantly generated due to shaving, and warp yarn breaks occur in some parts. There was a problem. Further, since the weight reduction treatment with caustic soda was not performed, the opening area% was as small as 33%, so that the ink permeability was inferior, and there were both a blurred portion and a broken portion of the printed fine line, and had a printing defect. . Example 5 Polyethylene terephthalate (C) having an intrinsic viscosity [η] of 1.0 was prepared as a core component of a composite monofilament. On the other hand, intrinsic viscosity [η] = 1 mol% of 5-sodium sulfoisophthalate and 5 mol% of isophthalic acid copolymerized into polyethylene terephthalate as a sheath component
A 0.72 polymer (D) was prepared.

Using the above polymer, composite spinning was performed so that the composite ratio of core: sheath was 7: 3 in terms of fiber cross-sectional area ratio.
Stretched in the same manner as described above, fineness 9 denier, strength 7.8
A concentric circular composite monofilament having g / d and elongation of 20% was obtained. The monofilament was used for the warp yarn and the weft yarn and woven with a sluser weaving machine, and was refined and set on a greige machine by a conventional method to obtain a 360-mesh plain-woven high mesh gauze. The opening area of this gauze was 33%.
The sheath component was dissolved and removed from the mesh gauze using a beam dyeing machine in the same manner as in Example 1. The weight reduction ratio between the core component and the sheath component of this screen gauze was 1:40. Then, the screen gauze was washed with water and finished at 195 ° C. by a conventional method to prevent misalignment. The opening area of this screen gauze is 41.5% and the breaking strength is 35 kg.
/ 5 cm. Furthermore, no lint-like scum is attached,
It was a high quality screen gauze.

[0037]

According to the present invention, it is possible to obtain an opening area with high accuracy even with a high mesh screen gauze, obtain a screen gauze for printing which has excellent dimensional stability and good ink permeability. Further, since the thickness of the gauze can be easily reduced, the amount of expensive ink used can be reduced.

[Brief description of the drawings]

FIG. 1 shows the relationship between the weight reduction processing time and weight reduction rate of a screen gauze made of a core-sheath composite monofilament,
The solid line in the figure is the weight loss curve of the sheath component (B), and the broken line is the weight loss curve of the core component (A).

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ Identification code FI D06M 5/02 F (56) References JP-A-62-220391 (JP, A) JP-A-64-45867 (JP, A) JP-A-56-49018 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41N 1/24 B41F 15/34 D03D 15/00 D06M 11/14

Claims (1)

(57) [Claims] 1. A plain woven screen gauze comprising a core-sheath composite monofilament comprising a polyester component having a higher dissolution rate in an alkaline solvent as a sheath component and a polyester component having a lower dissolution rate than the sheath component as a core component. After the setting, the screen gauze for printing, in which the sheath component was substantially dissolved and removed with an alkaline solvent, had a single yarn fineness of 7d or less, a woven density of 300 mesh or more, and an opening area of 35%.
A screen gauze for printing characterized by having a breaking strength of 25 kg / 5 cm or more.