JP2012140735A - Metal mesh fabric and screen printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal mesh fabric which can be used in highly precise and dense screen printing, is hard to generate stretch of a mesh by prolonged use, can maintain printing accuracy for a long period, and can be produced at low cost; and a screen printing plate using the metal mesh fabric.SOLUTION: The metal mesh fabric is provided, in which a warp and a weft composed of a metal wire are woven so as to intersect with each other. The warp and the weft each comprise: a core portion 51 composed of austenite-based stainless steel; a cured layer 52 provided so as to surround the core portion 51 and obtained by diffusing and penetrating carbon into the austenite-based stainless steel as a base material; and a black clad layer 53 surrounding the cured layer 52, and containing a carbide and an oxide represented by a chemical formula ABO(where A and B are any of Fe, Cr or Ni).

Description

  The present invention relates to a wire mesh for screen printing. More specifically, the present invention relates to a metal mesh for screen printing that enables high-precision and high-density screen printing in the field of electronics, and a screen printing plate using the metal mesh. It is about.

  In electronic devices such as personal computers, mobile phones, and liquid crystal televisions, many printed wiring boards on which various wiring patterns are applied and semiconductor devices such as LSIs are mounted are used. Such a printed wiring board is generally manufactured by forming a wiring pattern on a substrate by screen printing or the like. In recent years, electronic devices have been increasingly refined and densified, and wiring patterns and screen printing for printing them have been required to be finer and densified. A screen-printed version of is required.

  In screen printing, the screen printing plate and the substrate are arranged in parallel with a predetermined gap, the screen is pressed against the substrate while filling the mesh openings of the screen with a squeegee, and the screen is separated from the substrate by the screen tension. Ink is transferred to the substrate during “separation”. Unless this “plate separation” is improved, the printability is remarkably lowered, and high-precision printing cannot be realized. At this time, the larger the gap, the better the separation of the plate, but the larger the screen stretches during squeegeeing, the larger the mesh opening, the lower the resolution, and the shorter the life of the screen printing plate. . In other words, the printability and the life of the screen printing plate have a trade-off relationship.

  In order to achieve printing with high dimensional accuracy, maintain good printability, and ensure the life of the screen printing plate, it is necessary to have a screen printing plate that can separate the plate well while minimizing the gap. . For this purpose, a screen mesh material having a high strength and a low elongation that can stretch a screen printing plate with an extremely high tension is required.

  When the screen printing plate is stretched with the current mesh material, due to the effect of applying tension in two directions, the vertical and horizontal directions, a breakage often occurs when a tension of about 50% of the breaking strength is applied. However, in order to ensure good printability, it is required to perform tensioning with a tension of about 30 to 50% of the breaking strength. For this reason, the current mesh material is forced to be tensioned at a tension just before breaking, and the risk of breakage is extremely high. Therefore, if the breaking strength of the mesh material is increased, there is a margin to break even if it is tensioned with the currently required tension, and the risk of breakage is greatly reduced, so the breaking strength of the mesh material is improved. It has been demanded.

  The screen formed from the mesh material is further subjected to the printing tension by the squeegee described above in addition to the tension of the tension, but as described above, the screen printing plate that has been tensioned immediately before breakage is affected by the printing tension. Damage risk is further increased. Moreover, even if it is not damaged, if a load exceeding the elastic limit of the mesh material is applied by the printing tension, permanent strain remains and causes a dimensional change. In the above-described screen printing for the electronic industry, etc., a decrease in printing accuracy due to a dimensional change can be a fatal printing defect, so this situation must be avoided. Therefore, if the elastic limit of the mesh material is increased, the printing load is also within the elastic limit. Therefore, high-accuracy printing can be realized without causing permanent distortion. Therefore, an improvement in the elastic limit of the mesh material is required.

  On the other hand, in the screen printing plate as described above, the minimum value of the wiring width is determined by the size of the mesh opening of the screen, so that the wire material to be used has been thinned due to the recent demand for finer and higher density. In addition, printed wiring widths as narrow as about 10 to 20 μm have been demanded. In such a fine woven fabric, the strength and rigidity of the woven fabric itself are reduced, and it is difficult to withstand the above-described high tension tension, or the mesh is deformed when the wiring pattern is printed, and the printing accuracy is likely to decrease. There is a problem.

  In this way, the screen printing plate satisfies the demands of fine lines and fine mesh openings, yet does not cause mesh deformation due to high tension and printing stress. Development of a screen with high rigidity is required.

  As described above, in order to realize screen printing with high accuracy and high density, (1) high strength and low elongation, high tension can be stretched, and (2) excellent dimensional accuracy. Dimensional change is stable even when printing stress is applied, (3) the elastic recovery force is large and excellent in durability, and (4) the wire diameter is thin and the mesh is high density. Characteristics are required.

  As a screen that enables high-precision and high-density printing, synthetic fibers such as nylon and polyester cannot be used at all because the strength and elastic modulus are too low. , Strength, elastic recovery rate and low elongation properties are not sufficient.

  Therefore, the following is disclosed as a high-strength and high-rigidity screen.

  (1) Use an austenitic stainless steel wire, mesh the stainless steel wire that has been strengthened in terms of metallography, such as reducing the grain size, improving the component balance, or reducing non-metallic inclusions. Fabricating the fabric (for example, Patent Documents 1 and 2 below).

(2) Nickel-plated metal mesh fabric (for example, Patent Documents 3 and 4 below).

(3) What improved the physical property by forming a DLC (diamond-like carbon) film | membrane after ion-implanting in the textile member of a metal fiber (for example, following patent document 5).

(4) An austenitic stainless steel wire made into a woven fabric and then reinforced by dispersing carbide in the dough by vacuum carburization (for example, Patent Documents 6 and 7 below).

JP-A-11-006037 JP 2003-253399 A JP 2005-131851 A JP 2003-175684 A JP 2008-174790 A JP 2006-089836 A JP 2006-089837 A

  However, although the thing of the said patent document 1 makes the crystal grain size small and makes elongation rate 10 to 40%, a tensile strength is about 1400 MPa and is not enough in intensity | strength. Moreover, although the thing of the said patent document 2 has high tensile strength, since elongation is as small as less than 5%, there exists a possibility that it may fracture | rupture in a tension process. As described above, the conventional metal alloy with high strength using austenitic stainless steel wire has the disadvantage that the elongation decreases when the tensile strength is increased and the tensile strength decreases when the elongation rate is secured. there were.

  In addition, it is extremely difficult to weave with a low elongation metal wire having a narrow plastic region as described above. That is, the mesh material for screen printing is required to have high strength and low elongation as described above. However, if the narrow plastic region as described above is used as a characteristic of the low-strength metal wire itself, a high density Even when trying to narrow the mesh interval like a mesh, the linearity is maintained by the springback action due to the rigidity of the low-stretch metal wire itself, and it is difficult for the low-stretch metal wire to cause undulation deformation to make a fabric. In addition, the spacing between the low-stretch metal wires becomes wide, making it difficult to obtain a high-density mesh fabric.

  As described above, although the wire rod of austenitic stainless steel is easy to draw, there is a problem that if the tensile strength is increased, high elongation (elongation rate) cannot be secured, and if the elongation rate is secured, tensile strength is lowered. . That is, if a high elongation rate is secured, breakage during weaving, thinning of the wire diameter, non-uniformity of material properties due to increased hardness, etc. can be suppressed, but there is a problem that the life as a mesh fabric is shortened because the tensile strength is lowered. On the other hand, if the tensile strength is secured, the elongation rate decreases, so there is a problem that the risk of breakage due to tension tension increases, workability and yield deteriorate, and the risk of breakage due to printing stress increases, resulting in a short life. .

  As described in Patent Documents 3 and 4, a metal mesh fabric is plated with nickel, or as described in Patent Document 5 is a metal fabric coated with a DLC film. The material is coated with a hard material that is different from the above, and the elastic properties are borne by the base material stainless steel, so even if the nickel plating layer or the DLC coating film can assist in improving the strength, It is inevitable that the screen will stretch due to continuous use. In addition, the intersections of the vertical and horizontal fibers are reinforced by plating or the like, but there is also a problem that due to repeated printing stress, defects such as cracks and peeling are likely to occur in the plating film at the intersections, and the strength life is not so long. In addition, there is an inherent weakness that a film cannot be formed at the intersection between the warp and the weft at the intersection between the warp and the weft, depending on the conventional methods such as plating by the plating method or PVD method. Because there is, reinforcement of the intersection of warp and weft cannot be expected. Therefore, depending on a technique such as a hard film coating by a conventional plating method, PVD method, or the like, there is a possibility that the intersecting point where the warp and the weft come into contact is the weakest part, and the improvement in strength as a mesh fabric may be hindered.

  Although the thing of the said patent documents 6 and 7 disperse | distributed and strengthened the carbide | carbonized_material in dough by performing vacuum carburizing with respect to an austenitic stainless steel wire, it is a carburizing process at high temperature of 850-1050 degreeC. For this reason, a large amount of carbide is precipitated, and coarse carbide particles may appear due to variations in various conditions, which may be the starting point of fracture. Further, because of the high temperature treatment, the fabric itself may be distorted and the mesh may be deformed. Further, these high-temperature carburized meshes can be obtained with a relatively high elongation, but the tensile strength is only about 1200 MPa, and the strength is not yet sufficient.

  Moreover, it is said that the carburizing process is carried out while the fabric is rolled out and rolled up by roll-to-roll, but these operations must be performed in a vacuum, resulting in extremely high equipment costs and processing costs. This is extremely difficult to achieve. Furthermore, since the carbide is formed by high-temperature vacuum carburization, the corrosion resistance of stainless steel has to be significantly reduced, and depending on the function and characteristics of the liquid used for printing, it can not be used and the application is limited. There is also a problem.

  The present invention has been made in view of such circumstances, and can be used for high-precision and high-density screen printing in electronics-related fields, and is less likely to cause mesh elongation due to continuous use, and maintains printing accuracy for a long period of time. An object of the present invention is to provide a metal mesh fabric that can be manufactured at low cost, and a screen printing plate using the metal mesh fabric.

In order to achieve the above object, a first aspect of the present invention is a metal mesh fabric having a structure in which warps and wefts made of metal wire are woven so that they intersect each other, wherein each of the warps and wefts is ( a) a core portion made of austenitic stainless steel, and (b) a hardened layer provided so as to surround the core portion, with austenitic stainless steel as a base material, and carbon diffusing and penetrating into the base material, (c) The gist of the invention is that the metal mesh fabric includes a black clad layer that surrounds the hardened layer and includes a carbide and an oxide such as a spinel type represented by the chemical formula AB ₂ O ₄ . Here, the combination of the element A and the element B constituting the chemical formula AB ₂ O ₄ (the element B is an element different from the element A) is any of iron (Fe), chromium (Cr), and nickel (Ni). For example, NiFe ₂ O ₄ type spinel oxide is a typical example.

A second aspect of the present invention is a metal mesh that has a structure in which (a) a formwork and (b) a warp and a weft made of a metal wire are woven so as to cross each other, and is stretched inside the formwork The present invention relates to a screen printing plate provided with a fabric. That is, in the screen printing plate according to the second aspect of the present invention, each of the warp and the weft constituting the metal mesh fabric is provided so as to surround the core made of austenitic stainless steel and the core. A hardened layer in which austenitic stainless steel is used as a base material, carbon is diffused and permeated into the base material, and a black cladding layer that surrounds the hardened layer and includes carbide and an oxide represented by the chemical formula AB ₂ O _4. It is characterized by having. Similar to the first aspect of the present invention, the oxide represented by the chemical formula AB ₂ O ₄ contains oxides such as spinel, an element other than element A and element A constituting the chemical formula AB ₂ O ₄ The combination with B is a combination selected from any one of Fe, Cr, and Ni.

  According to the present invention, a metal mesh fabric that can be used for high-accuracy and high-density screen printing, is less prone to mesh elongation by continuous use, can maintain printing accuracy for a long period of time, and can be manufactured at low cost. In addition, a screen printing plate using a metal mesh fabric can be provided.

It is a SEM surface photograph which shows a part of 500 mesh low elongation mesh fabric based on embodiment of this invention. It is a SEM surface photograph which shows a part of 400 mesh low elongation mesh fabric based on embodiment of this invention. It is a schematic diagram explaining the cross-sectional structure of the low elongation metal wire which comprises the low elongation mesh fabric which concerns on embodiment of this invention as a model. It is a SEM photograph which shows the cross-section of the low elongation metal wire which comprises the 500 mesh low elongation mesh fabric which concerns on embodiment of this invention. It is a SEM photograph which shows the cross-section of the low elongation metal wire which comprises the 400 mesh low elongation mesh fabric which concerns on embodiment of this invention. It is an optical microscope photograph which shows the cross-section of the low elongation metal wire which comprises the 400 mesh low elongation mesh fabric which concerns on embodiment of this invention. It is a schematic diagram for demonstrating the surface morphology of the black clad layer of the low elongation metal wire which comprises the low elongation mesh fabric which concerns on embodiment of this invention. It is a figure which shows an example of the heat processing furnace for manufacturing the low elongation mesh fabric based on embodiment of this invention. It is a figure which shows an example of the stress-strain (elongation) curve in the tension test of the low elongation mesh fabric which concerns on embodiment of this invention. It is a figure which shows the tension test result of the low elongation mesh fabric of a vertical direction. It is a figure which shows the tension test result of the low elongation mesh fabric of a horizontal direction. FIG. 12A is a diagram in which printing coordinates of 9 points are plotted for a printing test using a screen printing plate using a soft metal mesh fabric according to a comparative example, and FIG. It is the figure which plotted the printing coordinates of 9 points | pieces about the printing test by the screen printing plate using an elongation mesh fabric. FIG. 13A is a line graph showing the change over time of the soft metal mesh fabric according to the comparative example, and FIG. 13B is a line graph showing the change over time of the low elongation mesh fabric according to the example. FIG. It is a figure which shows the load load-indentation depth curve of the 400 mesh low elongation mesh fabric which concerns on embodiment of this invention. It is a figure which shows the load load-indentation depth curve of the 500 mesh low elongation mesh fabric which concerns on embodiment of this invention. The relationship between the tension air pressure and tension of a 400 mesh low elongation mesh fabric according to an embodiment of the present invention is shown in comparison with the relationship between the tension air pressure and tension of a conventional soft metal mesh fabric. FIG. According to the screen printing plate using the 400 mesh low elongation mesh fabric according to the embodiment of the present invention, the change in tension when the print shot is increased from 100 shots to 13000 shots in order, the conventional soft metal It is a figure shown comparing with the fall of the tension | tensile_strength of a mesh fabric. It is a figure which shows the reflectance in the wavelength range of 200 nm-800 nm of the 400 mesh low elongation mesh fabric based on Embodiment of this invention compared with the reflectance of the conventional soft metal mesh fabric. It is a figure which shows the AES analysis result of the 500 mesh low elongation mesh fabric which concerns on embodiment of this invention. It is a figure which shows the AES analysis result of the 400 mesh low elongation mesh fabric which concerns on embodiment of this invention. It is a figure which shows the cross-sectional photograph of the optical microscope of the low elongation metal wire in the cross | intersection part of the weft and warp of the 400 mesh low elongation mesh fabric which concerns on embodiment of this invention. It is a figure which shows the relationship between a carburizing rate and breaking strength about the warp of the low elongation mesh fabric which concerns on embodiment of this invention. It is a figure which shows the relationship between a carburizing rate and breaking strength about the weft of the low elongation mesh fabric which concerns on embodiment of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The following embodiments of the present invention exemplify apparatuses and methods for embodying the technical idea of the present invention. The technical idea of the present invention is based on the material and shape of component parts. The structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

(Structure of low elongation mesh fabric)
A screen printing plate according to an embodiment of the present invention includes a mold frame (not shown) and a metal screen made of a low elongation mesh fabric that is stretched inside the mold frame. As the formwork used for the screen printing plate according to the embodiment of the present invention, from the viewpoint of strength and corrosion resistance, generally, an aluminum pipe joining type, a die-casting type, or a stainless steel formwork is cited. Can do. As described in the section “Problems to be Solved by the Invention”, it is extremely difficult to weave a low-stretch metal wire having a narrow plastic region into a mesh fabric, but the screen according to the embodiment of the present invention. In a low elongation mesh fabric used for a printing plate, a known method is used as a method of stretching a soft metal mesh fabric such as a direct tension method or a combination method on this formwork, and FIG. As shown in FIG. 1B, a low elongation metal wire having a diameter of, for example, 10 to 160 μm and made of austenitic stainless steel as a base material is woven into a mesh fabric such as plain weave or twill weave. The tensioned state is easily realized.

  FIG. 1 (a) shows an SEM photograph in the case of 500 mesh, and FIG. 1 (b) shows a SEM photograph in the case of 400 mesh. The low elongation mesh fabric used for the screen printing plate according to the embodiment of the present invention is For example, a topology woven to about 40 to 900 mesh has been realized with a structure having a low elongation metal wire made of austenitic stainless steel as a material.

  As modeled and shown in FIG. 3 (a), the low-strength metal wire material that realizes the low-strength mesh fabric of the screen printing plate according to the embodiment of the present invention is used as a base material at the center. Of the austenitic stainless steel remaining as an untreated region, a hardened layer 52 provided on the surface layer side of the core 51 and in which carbon diffuses and penetrates into the austenitic stainless steel as a base material, and a hardened layer 52 3 layer structure which consists of the black clad layer 53 provided in the surface of this.

As the austenitic stainless steel, for example, an austenitic stainless steel containing 50 mass% or more of iron (Fe), 12 mass% or more of chromium (Cr) and containing nickel (Ni) is suitable. . Specifically, 18-8 stainless steel materials such as SUS304, SUS316, and SUS303S, SUS310S and 309, which are austenitic stainless steels containing 25 mass% Cr and 20 mass% Ni, and a Cr content of 23 An austenite-ferrite two-phase stainless steel material containing 2% by mass and 2% by mass of molybdenum (Mo) can be used. Further, heat-resistant steel castings such as SCH21 and SCH22 containing 19 to 22% by mass of Ni, 20 to 27% by mass of Cr, and 0.25 to 0.45% by mass of carbon (C) are also related to the embodiment of the present invention. It is suitably used as an austenitic stainless steel. Further, SUH35 containing 20 to 22% by mass of Cr, 3.25 to 4.5% by mass of Ni, 8 to 10% by mass of manganese (Mn), and 0.48 to 0.58% by mass of carbon, Cr A heat-resistant steel such as SUH660 containing 13.5 to 16% by mass, Ni is 24 to 27% by mass, and Mo is 1 to 1.5% by mass is preferably used as the austenitic stainless steel according to the embodiment of the present invention. it can.

  The austenitic stainless steel used for the screen printing plate according to the embodiment of the present invention has the above-mentioned diameter of 10 to 160 μm as a representative value, and a wire material that has been drawn to a predetermined thickness as a base material. It can be used, and can be set to about 10 μm or less and 160 μm or more.

The hardened layer 52 shown in FIG. 3 is in a state in which a large amount of C atoms enter and dissolve in the austenite phase which is the base phase (base material), causing lattice expansion, which is significantly higher than that of the base material. Improved hardness. Moreover, since the C atoms penetrate into the crystal lattice and form a solid solution with almost no formation of Cr and Cr ₇ C ₃ or Cr ₂₃ C ₆ or the like in the base material, Cr carbides are contained in the hardened layer 52. Since particles are not substantially present and the amount of Cr dissolved in the base material is not reduced, the same level of corrosion resistance as that of the base material can be maintained.

As shown in the analysis results of Auger electron spectroscopy (AES) shown in FIGS. 19 and 20, the black clad layer 53 is an oxide and a carbide (Cr ₇ C ₃ , Fe ₃ C) represented by the chemical formula AB ₂ O _4. It is a thin layer that exhibits a black color. Here, the element B constituting the chemical formula AB ₂ O ₄ is an element different from the element A, and the combination of the element A and the element B is a combination selected from any of Fe, Cr, and Ni. The oxide represented by the chemical formula AB ₂ O ₄ includes an oxide such as a spinel type, and a NiFe ₂ O ₄ type spinel oxide is a typical example. FIG. 19 shows an AES analysis result of a low-stretch metal wire constituting a 500-mesh low-stretch mesh fabric according to an embodiment of the present invention, and FIG. 20 relates to a 400-mesh embodiment of the present invention. The AES analysis result of the low elongation metal wire which comprises a low elongation mesh fabric is shown. The AES analysis was performed by using ULVAC PHI SAM680 at an acceleration voltage of 10 kV and a beam current of 10 nA. At this time, Ar sputter etching for surface cleaning is performed for 3 minutes.
In the AES analysis data shown in FIG. 19, it can be read from FIG. 19 that the thickness of the black cladding layer 53 of the low-stretch metal wire constituting the low-stretch mesh fabric is about 0.8 μm for the 500 mesh low-stretch mesh fabric. (However, the resolution is 0.2 μm), this value corresponds substantially well to the value (= about 0.3 to 0.8 μm) obtained by SEM cross-sectional observation shown in FIG. From FIG. 19, the carbon concentration of the black cladding layer 53 is about 5 mass%, and the oxygen concentration of the black cladding layer 53 can be read as 30 to 45 at%. Then, the presence of an oxide represented by the chemical formula AB ₂ O ₄ can be inferred from the amount ratio of oxygen, Fe, and Ni in the black cladding layer 53 of FIG. 19 (as described above, the element A and the element of the chemical formula AB ₂ O ₄ (The combination with B is a combination selected from Fe, Cr, and Ni.) Carbon is considered to exist as a carbide of Fe ₃ C or Cr ₇ C ₃ , but the possibility of the presence of graphite cannot be denied because the number of metal atoms is small when viewed from the quantitative ratio with metal atoms. Table 1 shows the carbon concentration C _ks (mass) of the black clad layer 53 obtained by AES analysis, combustion method, SEM cross-sectional observation, and optical microscopic cross-sectional observation for the 500 mesh low elongation mesh fabric according to the embodiment of the present invention. %), The carbon concentration C _S (% by mass) of the surface of the hardened layer 52, the thickness K (μm) of the black cladding layer 53, the thickness D (μm) of the hardened layer 52, and these measured values. carbon concentration C _ks black cladding layer 53 to be estimated (by mass%), the carbon concentration C _S (mass%) of the surface of the hardened layer 52, the thickness K of the black cladding layer 53 ([mu] m), the thickness of the hardened layer 52 D (μm) was indicated. The analysis by the combustion method shown in Table 1 is in accordance with JIS G 1211, and the 500 mesh low elongation mesh fabric according to the embodiment of the present invention was analyzed with respect to 1 g of sample weight, but the analysis accuracy was 0.0002. %, The analysis range is 0.6 ppm to 6.0 mass% C.

On the other hand, in the AES analysis data shown in FIG. 20, the thickness of the black clad layer 53 of the low-stretch metal wire constituting the low-stretch mesh fabric is about Although it can be read as 1.1 μm (however, the resolution is 0.2 μm), this value corresponds to the value obtained by SEM cross-sectional observation shown in FIG. 5 (= about 0.1 to 0.9 μm) considering the resolution. ing. It can be determined that the carbon concentration of the black cladding layer 53 is 14.3 at% (3.5 mass%), and the oxygen concentration of the black cladding layer 53 is 30 to 40 at%. From the amount ratio of oxygen, Fe, and Ni in the black clad layer 53 of the AES analysis data shown in FIG. 20, the black clad layer 53 is an oxide represented by the chemical formula AB ₂ O ₄ , particularly a NiFe ₂ O ₄ type spinel type. Presence of oxide can be estimated. Carbon is considered to exist as a carbide of Fe ₃ C or Cr ₇ C ₃ , but the possibility of the presence of graphite cannot be denied because the number of metal atoms is small when viewed from the quantitative ratio with metal atoms. Unlike the 500 mesh low elongation mesh fabric shown in FIG. 19, in the case of the 400 mesh low elongation mesh fabric, there was no Cr concentration drop in the black cladding layer 53. The 400 mesh low elongation mesh fabric has a hardened layer 52 developed thicker than the 500 mesh low elongation mesh fabric, and is interpreted as the growth of carbides of Cr and Fe. . Table 2 shows the carbon concentration C _ks (mass) of the black cladding layer 53 obtained by AES analysis, combustion method, SEM cross-sectional observation, and optical microscopic cross-sectional observation for the 400 mesh low elongation mesh fabric according to the embodiment of the present invention. %), The carbon concentration C _S (% by mass) of the surface of the hardened layer 52, the thickness K (μm) of the black cladding layer 53, the thickness D (μm) of the hardened layer 52, and these measured values. carbon concentration C _ks black cladding layer 53 to be estimated (by mass%), the carbon concentration C _S (mass%) of the surface of the hardened layer 52, the thickness K of the black cladding layer 53 ([mu] m), the thickness of the hardened layer 52 D (μm) was indicated. Similar to Table 1, the analysis by the combustion method shown in Table 2 is in accordance with JIS G 1211. A 400 mesh low elongation mesh fabric according to an embodiment of the present invention was analyzed with respect to a sample weight of 1 g.

  Since the black clad layer 53 is continuous and firmly adhered to the underlying hardened layer 52, the black clad layer 53 can be peeled off by brushing or washing for removing sooting as described below. Or it is a layer which does not peel off by the operation | work etc. which stretch the low elongation mesh fabric after a carburizing process, and form in a screen printing plate.

4, 5, 6, and 21, the low-stretch mesh fabric according to the embodiment of the present invention is cut with scissors, the cut low-stretch mesh fabric is sandwiched between copper plates, and embedded in embedded resin. After that, the embedding resin is polished so that the cross section of the low-stretch metal wire constituting the low-stretch mesh fabric is exposed, and the cross-section after the final buffing of the cross-section of the low-stretch metal wire that is exposed Show. In the optical micrographs of FIGS. 6 and 21, the surface of the final buffed cross section was further etched with a marble reagent (CuSO ₄ (4 g) + HCl (20 cm ³ ) + H ₂ O (20 cm ³ )). It is the result of observing the surface of the cross section at 600 times. As a result of using the etching selection ratio in which only the core portion 51 is selectively etched by the marble reagent and the cured layer 52 is not etched, the cured layer 52 appears white in the cross-sectional photograph of the optical microscope. In particular, FIG. 21 shows a cross-sectional photograph of an optical microscope of the low elongation metal wire at the intersection of the weft and the warp. The cured layer 52 is substantially uniformly around the core 51 at the intersection of the weft and the warp. It can be seen that the throwing power of the cured layer 52 is good. As shown in FIG. 21, the low elongation mesh fabric according to the embodiment of the present invention does not reinforce the intersection of the weft and the warp with a coating, but hardened layer 52 by solid solution of carbon in the low elongation metal wire itself. Therefore, there is almost no defect such as cracking or peeling off in the conventional film at the intersection, and the strength life is greatly extended. In addition, a film cannot be formed at the intersection between the warp and the weft where the warp and the weft come into contact with each other by a conventional method such as plating with a plating method or PVD method. Accordingly, the rigidity of the crossing portion has no effect over the improvement of the rigidity of the wire itself, whereas the low elongation mesh fabric according to the embodiment of the present invention also cures at the crossing point where the warp and weft yarns of the crossing portion are in contact with each other. Since the layer 52 and the black clad layer 53 on the surface side of the hardened layer 52 are formed, the synergistic effect of improving the strength of the warp and weft increases the rigidity of the intersection more than the rigidity of the wire itself, and as a mesh fabric The strength of is significantly increased.

  As shown in the SEM surface photographs of FIG. 1 (b), FIG. 1 (c), FIG. 2 (b) and FIG. 2 (c), the low elongation constituting the low elongation mesh fabric according to the embodiment of the present invention. The surface morphology of the black cladding layer 53 formed on the outermost surface of the metal wire has micro unevenness. This unevenness is estimated to reflect the micro unevenness of the hardened layer 52 that is the underlying layer. FIG. 7 schematically shows the surface morphology of the black cladding layer 53 shown in the SEM surface photographs of FIGS. 1 (b), 1 (c), 2 (b) and 2 (c). However, in both cases of 500 mesh and 400 mesh, the convex width W1 is a value in the range of 0.3 to 1.5 [mu] m with a central value of 0.9 [mu] m, and the convex length R is a central value of 1. As 5 micrometers, it is a value of the range of 0.5-2.5 micrometers. The groove width W2 schematically shown in FIG. 7 has a value of 1.5 μm or less, and is estimated to correspond to the width of the grain boundary of the austenitic stainless steel as the base material. In wire drawing of austenitic stainless steel, a processed structure in which crystal grains are elongated in the length direction due to large plastic deformation in one direction develops significantly, and oxide, Cr, and Fe carbide crystals growing on this surface are the base material. It is considered that the microscopic irregularities are formed on the surfaces of the hardened layer 52 and the black clad layer 53 by growing into a form that leaves the form of the tissue. Regarding the surface roughness Ra specified in JIS B 0601-1994, there is an insufficient measurement surface, but in the range of data currently obtained by SEM cross-section observation and atomic force microscope (AFM) measurement. The surface roughness Ra is estimated to be about 5 nm to 20 nm. Therefore, although the micro unevenness on the surface of the black clad layer 53 is exaggerated in the model diagram of FIG. 3A, it is an expression for convenience and is a diagram that faithfully reflects the actual surface morphology. Note that there is no.

  As is apparent from a comparison between FIGS. 1B to 1C and FIGS. 2B to 2C, the surface morphology of the 400 mesh cured layer 52 is the surface morphology of the 500 mesh cured layer 52. In the field of view of the photographic image in the range of 25 μm long side and 20 μm long side of the SEM observation image observed at 5000 times, at least 45 convex regions were confirmed in the case of 400 mesh. On the other hand, in the case of 500 mesh, at least 80 convex regions are confirmed, and the 400 mesh cured layer 52 has fewer convex regions than the surface of the 500 mesh cured layer 52, and the convex length R Is also a small tendency. However, the groove width W2 in the length direction of the line is almost the same as the surface morphology of the hardened layer 52 of 400 mesh and 500 mesh.

  Although the low elongation metal wire constituting the low elongation mesh fabric according to the embodiment of the present invention has micro unevenness on the surface of the hardened layer 52, it does not cause dimensional change or magnetism due to swelling.

Further, at the intersecting portion of the weft and the warp constituting the low elongation mesh fabric, the hardened layer 52 and the black clad layer 53 can be formed almost uniformly around the core portion 51. Excellent uniformity. Therefore, the surface roughness of the low-elongation mesh fabric is small and the dimensional change is relatively small, and the surface of the low-elongation mesh fabric is uniformly modified, including the intersection of the weft and the warp. I can judge. Further, among the austenitic stainless steels, the stable austenitic stainless steel containing a large amount of Ni and the stable austenitic stainless steel containing Mo have better corrosion resistance of the hardened layer 52.

Since the surface of the black cladding layer 53 of the low elongation metal wire constituting the low elongation mesh fabric according to the embodiment of the present invention has micro unevenness, the water contact in the soft metal mesh fabric according to the prior art Whereas the angle is about 110 °, the contact angle of water in the low elongation mesh fabric according to the embodiment of the present invention is about 93 °, which improves the wettability. Here, the contact angle of water is such that water is dropped 0.02 cm ³ each on the soft metal mesh fabric according to the prior art and the low elongation mesh fabric according to the embodiment of the present invention, and after 20 seconds. The state of the droplet was photographed, and the contact angle was calculated from the diameter and height of the droplet of the photographed image.

  Therefore, when the low elongation mesh fabric according to the embodiment of the present invention is used for a screen printing plate, the ink transmission performance is improved. By improving the ink transmission performance, using a 640-mesh screen printing plate, in a line and space L / S = 50/50 μm and line and space L / S = 30/30 μm printing test, When a soft metal mesh fabric according to the prior art is used for a screen printing plate, disconnection occurs, but when a low elongation mesh fabric according to an embodiment of the present invention is used for a screen printing plate, No disconnection occurred.

(Production method of low elongation mesh fabric)
(A) The low elongation mesh fabric according to the embodiment of the present invention is first made soft as the material physical property of the wire before weaving, and is woven into the mesh fabric using the soft wire. That is, the wire before weaving is in a state of a tempering classification “soft No. 1 (W1)” in which a solid solution treatment is performed as a finishing treatment after wire drawing, or a solid solution treatment is performed as a finishing treatment after wire drawing. After performing, it is made into the state of the refining classification "soft 2 (W2)" which performs a mild wire drawing process. The material physical property values in “Soft No. 1 (W1)” and “Soft No. 2 (W2)” are respectively equivalent to the values shown in the following Table 3 and Table 4, for example, and the wire diameter is 10 to 50 μm. In this case, the tensile strength is set to about 600 to 1300 N / mm ² and the elongation is set to about 8 to 25%.

  In addition, the tempering process after a wire drawing is not limited to the example mentioned above, It can replace with a solution treatment and can also perform softening annealing, and can also combine these. Thus, by weaving the mesh fabric in a soft state, the wavy deformation of the longitudinal fibers and the transverse fibers can be facilitated, the mesh density of the mesh fabric can be increased, and the mesh opening can be reduced, for example 400 It can be a high density metal mesh such as a mesh or more. By using such a high-density mesh, the printing resolution can be improved. Further, even when a high-density mesh is used, defects in the wire itself are less likely to occur, and the strength of the mesh fabric can be increased without increasing the risk of breakage. In addition, as a weaving method, various conventionally known methods can be employed.

(B) Next, a soft metal mesh fabric obtained by weaving a soft austenitic stainless steel wire is fluorinated using an atmosphere heating furnace such as the muffle furnace 1 illustrated in FIG. (The details of the muffle furnace 1 will be described later). Fluorine compound gas composed of NF ₃ , BF ₃ , CF ₄ , HF, SF ₆ , C ₂ F ₆ , WF ₆ , CHF ₃ , SiF ₄ , ClF _3, etc. is adopted as the fluorine-based gas used for the fluorination treatment. Is possible. These may be used alone or in combination of two or more. In addition to these gases, a fluorine-based gas containing fluorine (F) in the molecule can also be used as the fluorine-based gas according to the embodiment of the present invention. Further, it is possible to use such a fluorine compound gas F ₂ gas and that generated by thermal decomposition at a thermal decomposition apparatus, as F ₂ gas is also a fluorine-based gas premade. Such a fluorine compound gas and F ₂ gas can be mixed and used in some cases. Among these, NF ₃ has the most practical utility as the fluorine-based gas used in the method for producing the low elongation mesh fabric according to the embodiment of the present invention. This is because NF ₃ is gaseous at room temperature, has high chemical stability, and is easy to handle. Such NF ₃ gas is usually used in combination with N ₂ gas and diluted within a predetermined concentration range as described later. Various fluorine-based gases can be used alone, but are usually diluted with an inert gas such as N ₂ gas. The density | concentration of the fluorine-type gas itself in such a diluted gas is 10,000-100,000 ppm on a volume basis, for example, Preferably it is 20000-70000 ppm, More preferably, it is 30000-50000 ppm. Specifically, an untreated soft metal mesh fabric is placed in the furnace of the muffle furnace 1 and is maintained in a heated state in a fluorine-based gas atmosphere having a predetermined concentration as described above. The heating and holding during the fluorination treatment is performed by holding the soft metal mesh fabric itself at a temperature of, for example, 180 to 400 ° C, preferably 200 to 350 ° C, more preferably 220 to 300 ° C. The holding time of the soft metal mesh fabric in the fluorine-based gas atmosphere is usually set to 10 minutes to several hours, for example, about 15 minutes to 3 hours. Both the 500 mesh low elongation mesh fabric shown in FIG. 1, FIG. 4 and Table 1 and the 500 mesh low elongation mesh fabric shown in FIG. 2, FIG. 5 and Table 2 are both NF ₃ gas 5% by volume. In an atmosphere of 95% by volume of N ₂ gas, fluorination treatment is performed by heating and holding at 280 ° C. for 1.5 hours. By heat-treating a soft metal mesh fabric in such a fluorine-based gas atmosphere, compared to a passive film containing Cr ₂ O ₃ formed on the surface of a soft wire constituting the soft metal mesh fabric, It is considered that the penetration of C atoms used for carburization is facilitated, and the surface of the soft wire becomes a surface state that allows easy penetration of C atoms by fluorination treatment.

(C) Next, carburizing treatment is performed on the soft metal mesh fabric at the same time and / or after the fluorination treatment using an atmosphere heating furnace such as the muffle furnace 1 illustrated in FIG. In the carburizing process, the soft metal mesh fabric itself is heated to a carburizing temperature of 550 ° C. or less, preferably 360 to 450 ° C., and carburizing gas composed of CO + H ₂ or RX gas [CO 23 vol%, CO ₂ 1 vol% , H ₂ 31 vol%, H ₂ O 1 vol%, balance N ₂ ] + CO ₂ and the like, and the inside of the furnace is made into a carburizing gas atmosphere. This carburizing gas atmosphere can be enriched with a carbon source gas such as propane gas, if necessary. For example, in the CO + H ₂ production method, not only LP gas modification, but also liquid hydrocarbons such as methanol and isopropanol are useful as carburizing gas modification materials because of high H 2 concentration. Thus, in the manufacturing method of the low elongation mesh fabric which concerns on embodiment of this invention, a carburizing process is performed in a very low temperature range compared with a conventionally well-known carburizing process. In this case, the ratio of CO + H ₂ is preferably 2-50% by mass of CO and 30-90% by volume of H ₂ , and RX + CO ₂ is preferably a ratio of RX of 80-90% by volume and CO ₂ of 0-7% by volume. Moreover, CO + CO ₂ + H ₂ is also used as the gas used for carburizing. In this case, each of the ratios, CO5～55 _volume%, CO 2 0 to _3% by volume, the ratio of H 2 50 to 95 volume% can be employed. As the heating temperature in the carburizing treatment, that is, the carburizing treatment temperature, a temperature of 550 ° C. or less, that is, 360 to 550 ° C. can be employed. This is because when the carburizing temperature exceeds 550 ° C., the diffusion of carbon is accelerated, and the hardened layer 52 develops in an extremely short time, causing excessive carburization. This is because, particularly in the case of a mesh having a small wire diameter, it is difficult to control the balance of the thickness of the hardened layer 52 under the condition that the thickness of the hardened layer 52 is increased in a short time. In addition, carburized C atoms combine with Cr dissolved in the base material to produce Cr carbide, and the amount of Cr contained in the base material itself is reduced to greatly reduce the corrosion resistance of the surface layer portion. This is because the amount of carbon existing in the state of intrusion and solid solution in the carburized layer is reduced, the strength and corrosion resistance of the base material are lowered, and it becomes magnetized. For the same reason, a temperature range of 360 to 550 ° C. is more preferable as the carburizing temperature, a temperature range of 380 to 490 ° C. is more preferable, and a temperature range of 400 to 450 ° C. is more preferable. The low-elongation mesh fabric of 500 mesh shown in FIGS. 1 and 4 and Table 1 was subjected to carburizing treatment for 2 hours at 400 ° C. in an atmosphere of 10% by volume of CO and 90% by volume of H ₂ . Carburizing treatment is performed at 450 ° C. for 2 hours in an atmosphere of 400 mesh low elongation mesh fabric shown in FIG. 5 and Table 2, CO 10 vol%, H ₂ 90 vol%. In the manufacturing method of the low elongation mesh fabric according to the embodiment of the present invention, by performing the fluorination treatment, carburizing treatment at such an extremely low temperature becomes possible, and most of the Cr carbide particles are generated during the carburizing treatment. Instead, carbon is intruded into the base material to form a solid solution, and the lattice size is increased to form the hardened layer 52 in the surface layer portion. The processing time of the carburizing process is normally set to 10 minutes to 10 hours, for example, about 15 minutes to 8 hours.

  (D) The low elongation mesh fabric according to the embodiment of the present invention is removed by brushing or washing as necessary because carbonaceous soot is attached to the surface by sooting immediately after carburizing treatment. To be done.

  As described above, according to the method for producing a low elongation mesh fabric according to the embodiment of the present invention, a fluorination treatment is performed on a soft metal mesh fabric obtained by weaving a soft austenitic stainless steel wire. Therefore, a soft metal mesh fabric can be heated and held at a low temperature of 360 ° C. or higher and 490 ° C. or lower and carburized. A hardened layer 52 in which carbon is dissolved in the austenite phase of the base material, on the surface layer side of the low-stretch metal wire that surrounds the core 51, leaving a core portion 51 where the material remains as an untreated region, and a hardened layer Further, a black clad layer 53 can be formed on the surface layer side of 52. In particular, as shown in FIG. 21, according to the method for producing a low elongation mesh fabric according to the embodiment of the present invention, the cured layer 52 is substantially uniformly cored even at the intersection of the weft and warp forming the mesh. It can be formed around the portion 51.

  According to the method for producing a low elongation mesh fabric according to the embodiment of the present invention, the low elongation metal wire constituting the low elongation mesh fabric includes the crossing portion of the weft and the warp on the entire mesh. 3 is formed substantially uniformly so as to have a concentric three-layer structure of the core portion 51, the hardened layer 52, and the black clad layer 53 as schematically shown in FIG. 3, but the hardened layer 52 formed by carburizing treatment, In particular, the carbon concentration in the vicinity of the surface is sufficiently high, the strength is sufficiently improved by lattice expansion, and excellent surface hardness is imparted, resulting in a low elongation metal wire. Also, since the surface hardness of the product can be measured by sampling and inspection of the intermediate product after carburizing treatment, the quality characteristic standard of the intermediate product is created, and those that do not meet it are subjected to fluorination treatment and carburization treatment again. It is possible to improve the yield by reducing the defective rate of the final product. In particular, as the hardness of the hardened layer 52 of the low-stretch metal wire, the micro Vickers hardness or Knoop hardness measured from the surface of the base material is used as a reference, so that the product can be inspected non-destructively and the yield reduction can be reduced.

  The manufacturing method of the low elongation mesh fabric which concerns on embodiment of this invention is not the method of disperse | distributing a carbide | carbonized_material by vacuum carburizing with respect to an austenitic stainless steel wire like the prior art described in patent document 6, 7. Therefore, it is possible to perform a carburizing process at a low temperature of 550 ° C. or less, particularly about 360 ° C. to 490 ° C., and as a result, a large amount of carbide precipitates as in the conventional techniques described in Patent Documents 6 and 7. Therefore, there is no problem that coarse carbide particles appear due to the influence of various conditions and the coarse carbide particles become the starting point of fracture. In addition, because of the low temperature treatment at 550 ° C or lower, there is no problem that the mesh itself is distorted and the mesh is deformed. Therefore, when used for screen printing plates, the strength life of screen printing plates is greatly extended. The printing accuracy can be maintained for a long time.

  Moreover, the low elongation mesh fabric manufacturing method according to the embodiment of the present invention is a roll-to-roll feeding and winding of the fabric in a vacuum as in the prior art described in Patent Documents 6 and 7. There is no need to perform carburizing while removing the material, and the equipment cost and processing cost can be reduced, which is extremely useful industrially. Furthermore, since the treatment is performed at a low temperature of 550 ° C. or lower, there is no reduction in the corrosion resistance of stainless steel, and the problem that the application is limited by the function and characteristics of the liquid used for printing can be avoided.

(Muffle furnace structure)
As shown in FIG. 8, a muffle furnace 1 suitable for use in the method for producing a low elongation mesh fabric according to an embodiment of the present invention includes an outer shell 2 and an inner container 4 having an inside formed in a processing chamber. The heater 3 provided between the inner container 4 and the outer shell 2 is provided. A gas introduction pipe 5 and an exhaust pipe 6 communicate with the inner container 4. A gas cylinder 15 filled with carburizing gas H ₂ and CO and a gas cylinder 16 filled with fluorination gas N ₂ + NF ₃ and CO ₂ communicate with the gas introduction pipe 5. 17 is a flow meter, and 18 is a valve. An exhaust gas treatment device 14 and a vacuum pump 13 are connected to the exhaust pipe 6, and a treatment gas is introduced into the treatment chamber in the inner container 4 and discharged. A fan 8 with a motor 7 for stirring the processing gas is provided in the processing chamber. The soft metal mesh fabric 11 made of soft austenitic stainless steel, which is a workpiece, can be placed in the inner container 4 and heat-treated in the form of a loose coil, that is, a loose coil.

After putting the soft metal mesh fabric 11 in the inner container 4, the cylinder 16 is connected to the flow path, and a fluorine-based gas such as NF ₃ is introduced into the muffle furnace 1 and subjected to fluorination treatment while being heated, Next, the gas is drawn out from the exhaust pipe 6 by the action of the vacuum pump 13, detoxified in the exhaust gas treatment device 14, and discharged outside.

  Next, the cylinder 15 is connected to the flow path, the carburizing gas described above is introduced into the muffle furnace 1, and the soft metal mesh fabric 11 is carburized, and then the exhaust pipe 6 and the exhaust gas treatment device. The gas is discharged to the outside via 14. By performing the fluorination treatment and the carburizing treatment by this series of operations, the core portion 51 in which the base material remains as an untreated region remains in the central portion of the low elongation metal wire, and the low elongation surrounding the core portion 51 is left. A hardened layer 52 in which carbon is dissolved in the austenite phase of the base metal is formed on the surface layer side of the metal wire, and a black cladding layer 53 is further formed on the surface layer side of the hardened layer 52.

(Mechanical properties of low elongation mesh fabric)
As schematically shown in FIG. 3, the low elongation mesh fabric according to the embodiment of the present invention is subjected to carburizing treatment on a soft metal mesh fabric obtained by weaving a soft austenitic stainless steel wire. The core portion 51 in which the base material remains as an untreated region is located in the center of the low-stretch metal wire, and the austenite phase of the base material is carbonized on the surface layer side of the low-stretch metal wire surrounding the core portion 51. A hardened layer 52 in which is dissolved, and a black clad layer 53 is located on the surface layer portion side of the hardened layer 52 so as to surround the hardened layer 52.

  In such a concentric three-layer structure of the core portion 51, the hardened layer 52, and the black clad layer 53, the carbon concentration in the hardened layer 52 formed by carburizing process, in particular, in the vicinity of the surface is sufficiently high. The strength is sufficiently improved and excellent surface hardness is imparted, and the 1% proof stress can be 1.1 to 3 times that of the soft metal mesh fabric before treatment. Moreover, by performing the process which forms the hardened layer 52 in the surface layer part of a wire, an elastic modulus can be 1.1 to 2.5 times with respect to the soft metal mesh fabric before a process. Furthermore, by performing a process of forming a concentric three-layer structure of the core part 51, the hardened layer 52, and the black clad layer 53, the elastic limit is 1.1 to 3.5 with respect to the soft metal mesh fabric before the process. Can be doubled.

As a result, the mechanical strength characteristics of the low elongation mesh fabric can be as follows (a) to (d):
(A) The low elongation mesh fabric in the machine direction has a breaking strength of 1000 MPa to 2600 MPa, a break elongation of 1% to 8%, and a 1% yield strength of 900 MPa to 2400 MPa. Breaking strength is 1200 MPa to 3400 MPa, breaking elongation is 0.8% to 6%, 1% proof stress is 900 MPa to 2800 MPa;
(B) The elastic limit as a low elongation mesh fabric in the longitudinal direction is 500 MPa or more and 1800 MPa or less, and the elastic limit as a low elongation mesh fabric in the transverse direction is 600 MPa or more and 2400 MPa or less;
(C) The elastic modulus as a low elongation mesh fabric in the longitudinal direction is 40 GPa or more and 120 GPa or less, and the elastic modulus as a low elongation mesh fabric in the transverse direction is 80 GPa or more and 240 GPa or less;
(D) The elastic elongation as a low elongation mesh fabric in the longitudinal direction is 0.8% or more and 3% or less, and the elastic elongation as a low elongation mesh fabric in the transverse direction is 0.6% or more and 1.8% or less. It is.

   FIG. 9 shows an example of a stress-strain (elongation) curve when a low elongation mesh fabric is subjected to a tensile test. In the curve shown in FIG. 9, the stress Cy when broken is the breaking strength (MPa), and the permanent strain (elongation) Cx when broken is the breaking elongation (%). The stress By when the permanent set (elongation) is 1% is 1% yield strength (MPa). Further, in the curve of FIG. 9, the maximum stress Ay that can be elastically recovered without leaving permanent set (elongation) is the elastic limit (MPa), and the maximum strain that can be elastically recovered without leaving permanent set (elongation). (Elongation) is elastic strain (elongation) (%). Further, the slope E in the elastic deformation region up to the elastic limit is the elastic coefficient (GPa). The stress-strain (elongation) curve was measured according to the general textile test method JIS L 1096 as follows.

The size of the metal mesh fabric was 25 mm wide × 150 mm long, and the distance between chucks was 100 mm. In this example, Shimadzu AGS-J1000 was used as the testing machine, and the tensile speed was 50 mm / min. From the number of meshes (M), the number of wires (N = M / 25.4 × 25) per 25 mm fabric width is obtained, while the cross-sectional area of the wire (S = πr ² × N) from the wire diameter (2r). / 1000000) was calculated, the cross-sectional area (N × S) of the test piece was obtained, and the measured value (P) was divided by the cross-sectional area (N × S) to obtain the apparent stress.

  FIG. 22 is a diagram showing the relationship between the carburization rate D / r (%) and the breaking strength of the warp yarn of the low elongation mesh fabric according to the embodiment of the present invention. Here, the carburization rate D / r is an amount defined by the ratio between the thickness D of the hardened layer 52 shown in Tables 1 and 2 and the radius r of the low-stretch metal wire constituting the low-stretch mesh fabric. . In FIG. 22, ◯ indicates the case of 640 mesh, and ♦ indicates the case of 500 mesh, but both 640 mesh and 500 mesh have a carburization rate D / r = 10% to 60% across both sides of the vertical broken line. It can be seen that the breaking strength is improved within the range.

  Similarly, FIG. 23 is a diagram showing the relationship between the carburization rate D / r (%) and the breaking strength of the weft of the low elongation mesh fabric according to the embodiment of the present invention. In FIG. 23, ◯ indicates the case of 640 mesh, and ◆ indicates the case of 500 mesh, which is the same as in FIG. 22, but both 640 mesh and 500 mesh have carburization rates sandwiching both sides of the vertical broken line. It can be seen that the breaking strength is improved in the range of D / r = 10% to 60%.

(Example)
The low elongation mesh fabrics of Examples 1 to 5 were obtained under the conditions shown in Table 5 below. The atmosphere for the fluorination treatment was fluorinated gas concentration of 30000 ppm (remaining N ₂ gas), and the atmosphere for the carburization treatment was 10 volume% CO + 90 volume% H ₂ .

[Tensile test results]
10 and 11 show the tensile test results of 250 mesh, 400 mesh, and 640 mesh low elongation mesh fabrics. The example which concerns on embodiment of this invention WHEREIN: As a comparative example, the tension test result of the untreated soft metal mesh fabric which has not performed the fluorination process and the carburizing process is shown simultaneously. As shown in the measurement results in the vertical direction of FIG. 10 and the measurement results in the horizontal direction of FIG. 11, the 1% yield strength of the soft metal mesh fabric before treatment is 250 mesh as shown in Table 6 below. 1.6 to 1.7 times, 1.7 to 1.9 times for 400 mesh, and 1.9 to 2.0 times for 640 mesh. The elastic modulus is 1.2 to 1.5 times for 250 mesh, 1.1 to 1.2 times for 400 mesh, and 1.3 to 1.4 times for 640 mesh. Yes. The elastic limit is 1.3 to 1.6 times for 250 mesh, 1.5 to 1.9 times for 400 mesh, and 1.9 to 2.0 times for 640 mesh. Yes.

[Print accuracy evaluation results]
About the metal mesh fabric of the Example and the comparative example, it was made the screen printing plate of the same specification, and the time-dependent change of printing accuracy was evaluated.

  The test method is as follows.

○ Use mesh Comparative example (untreated) SUS304 500 mesh, φ16 μm, calendering Example Metal mesh fabric is fluorinated and carburized Fluoride treatment conditions 3% by volume NF ₃ + balance N ₂ atmosphere, 240 ° C. × 90 minutes Carburizing treatment conditions 10% CO + balance H ₂ atmosphere, 420 ° C x 2 hours ○ Screen size: 320mm x 320mm
○ Emulsion film thickness: 15μm
○ Printing machine: LS-150
Printing speed: 60mm / sec
○ Evaluation Method When the number of shots was a specified number, printing was performed on a glass substrate, the coordinates of predetermined nine points of the printed material were measured, and the deviation (direction, distance) from the printed material of the first shot was measured and plotted.

  12 and 13 are diagrams showing printing accuracy evaluation results of the screen printing plate using the soft metal mesh fabric according to the comparative example and the screen printing plate using the low elongation mesh fabric according to the example. That is, FIG. 12A is a diagram in which printing coordinates of 9 points are plotted for a printing test using a screen printing plate using a soft metal mesh fabric according to a comparative example, and FIG. It is the figure which plotted the printing coordinate of 9 points | pieces about the printing test by the screen printing plate using the low elongation mesh fabric which concerns. FIG. 13A is a line graph showing the change over time of the soft metal mesh fabric according to the comparative example, and FIG. 13B is a line graph showing the change over time of the low elongation mesh fabric according to the example. FIG. As can be seen from the results of FIG. 12, it can be seen that the low elongation mesh fabric according to the example has higher printing dimensional accuracy than the soft metal mesh fabric according to the comparative example. In particular, it can be seen that after 5000 shots, the accuracy degradation of the soft metal mesh fabric according to the comparative example becomes severe, whereas the low elongation mesh fabric according to the example suppresses the accuracy degradation low.

(Strength properties of cured layer)
Using an ultra-micro hardness measuring device (Model ENT-1100a manufactured by Elionix Co., Ltd.), controlling the micro load using the electromagnetic actuator as a load loading device, and pushing a triangular pyramid (Berkovic type) indenter into the sample By continuously measuring the load applied to the indenter and the indentation depth during loading and unloading using a capacitance displacement meter as an indenter displacement measuring device, the load loading-indentation as shown in FIGS. A depth curve is obtained. The load load-indentation depth curves shown in FIGS. 14 and 15 are the results of measurement with a load load of 5 mN, a division number of 500, a step interval of 20 msec, and a holding time of 1000 msec.

FIG. 14 shows the measurement results in the case of 400 mesh and a wire diameter of 23 μm, and FIG. 15 shows the measurement results in the case of 500 mesh and the wire diameter of 16 μm. From the load-load-indentation depth curves shown in FIGS. 14 and 15, data such as hardness and elastic modulus as shown in Table 7 can be obtained, and although not shown, untreated soft Similarly, for metal mesh fabrics, obtain load load-indentation depth curves for 400 mesh, wire diameter of 23 μm, and 500 mesh, wire diameter of 16 μm to obtain data such as hardness and elastic modulus. Table 7 below shows a comparison with the low elongation mesh fabric according to the example.

  From Table 7, (b) Martens hardness HM is about 2 times (1.8 and 2.25 times) larger than untreated soft metal mesh fabric by carburizing treatment. The indentation elastic modulus corresponding to the Young's modulus of the piece is larger than that of the untreated soft metal mesh fabric, but the degree of increase tends to be greatly different between 400 and 500 mesh. (C) It can be seen that the indentation depth h2 (displacement at the start of unloading) is about 30% (29% and 36%) smaller than that of the untreated soft metal mesh fabric.

(Tension tension)
FIG. 16 shows the relationship between tension air pressure (MPa) and tension (mm) in the case of 400 mesh, tension air pressure (MPa) of a soft metal mesh fabric not subjected to conventional fluorination treatment / carburization treatment. It is a figure shown comparing with the relationship between tension and (mm). Since the low elongation mesh fabric according to the embodiment of the present invention has high strength and low elongation, as shown in FIG. 16, the tension of the screen printing plate is set to a sinking distance of 0.65 mm or less. It becomes possible to carry out with extremely high tension.

  The tension shown in FIG. 16 is a tension gauge STG-75B (manufactured by Protec) that is used in the screen industry as a standard, and the sinking distance (mm) is measured in an analog manner using a dial gauge.

  16 indicates the tension of the warp yarn of the low elongation mesh fabric according to the embodiment of the present invention, and □ indicates the tension of the weft yarn of the low elongation mesh fabric according to the embodiment of the present invention. In FIG. 16, Δ indicates the warp tension of the conventional soft metal mesh fabric, and ▽ indicates the weft tension of the conventional soft metal mesh fabric. As shown in FIG. 16, since the tension air pressure gradually increases and the tension air pressure exceeds 1000 MPa, the conventional fluorination treatment / carburization treatment of the low elongation mesh fabric according to the embodiment of the present invention is performed. An advantage over the soft metal mesh fabric that has not been applied appears, and the conventional soft metal mesh fabric achieves a tension of subsidence distance of 0.65 mm or less even when the tension air pressure is increased to about 1400 MP. I understand that I can't.

  As shown in FIG. 16, the screen printing plate can be stretched with an extremely high tension with a sinking distance of 0.65 mm or less. Since the separated screen printing plate can be realized, it is possible to achieve printing with high dimensional accuracy, maintain good printability, and ensure the life of the screen printing plate.

  FIG. 17 shows 100 shots, 500 shots, 1000 shots, 2000 shots, 3000 shots, 3500 shots, 4000 shots, 5000 shots, 6000 shots, in the case of a screen printing plate using a 400 mesh low elongation mesh fabric. The conventional fluoridation / carburization process shows the increase in print shots in order of 7000 shots, 7500 shots, 8000 shots, 9000 shots, 10000 shots, 11000 shots, 12000 shots, 13000 shots, and the state of tension reduction due to aging. It is a figure shown in comparison with the fall of the tension | tensile_strength by printing and aging of the soft metal mesh fabric which has not been performed. The circles in FIG. 17 indicate changes in the warp tension of the low elongation mesh fabric according to the embodiment of the present invention, and the squares indicate changes in the weft tension of the low elongation mesh fabric according to the embodiment of the present invention. Indicates. In FIG. 17, Δ indicates a change in the warp tension of the conventional soft metal mesh fabric, and ▽ indicates a change in the weft tension of the conventional soft metal mesh fabric. As shown in FIG. 17, in the case of a conventional soft metal mesh fabric, a decrease in tension is already observed immediately before aging and immediately before printing, and is 100 shots, 500 shots, 1000 shots, 2000 shots, 3000 shots, 3001 shots. It can be seen that as the printing of 3500 shots and 4000 shots progresses, the tension decreases more and more. On the other hand, in the case of the low elongation mesh fabric according to the embodiment of the present invention, it is recognized that almost constant tension can be maintained from 100 shots to about 10,000 shots for both warp and weft. It can be seen that printing can be continued up to about 10,000 shots with high dimensional accuracy within a tolerance of 10 μm, so that good printability can be maintained for a long time and the life of the screen printing plate can be ensured.

(Optical characteristics of low elongation mesh fabric)
Already, as shown in the SEM surface photograph of FIG.1 (b), FIG.1 (c), FIG.2 (b), and FIG.2 (c), the low elongation mesh fabric which concerns on embodiment of this invention is comprised. Since the surface of the black cladding layer 53 located on the outermost surface of the low elongation metal wire has micro unevenness, as shown in FIG. 18, when a low elongation mesh fabric is used for a screen printing plate, Compared with a screen printing plate using a soft metal mesh fabric, the reflectance can be lowered and the resolution of the photosensitive resin can be improved.

  FIG. 18 shows the reflectance in the wavelength range of 200 nm to 800 nm in the case of 400 mesh, and the reflectance of the conventional soft metal mesh fabric is 27% to 45%, which is a characteristic that increases as the wavelength increases. On the other hand, the reflectance of the low elongation mesh fabric according to the embodiment of the present invention is a low value of 15% to 13%, and it can be understood that a constant value can be maintained such that wavelength dependency is hardly recognized. .

  As described above, the low elongation mesh fabric according to the embodiment of the present invention includes the black cladding layer 53 on the outermost surface of the low elongation metal wire constituting the low elongation mesh fabric, and includes the intersection of the weft and the warp. By having the mesh uniformly, when used as a screen printing plate, the resolution is not lowered due to reflection or gloss from the wire during pattern exposure, and the effect of improving the resolution is obtained. For this reason, the process of blackening process, such as the black dyeing conventionally performed with respect to the screen printing plate, can be skipped. As described above, since the adhesion of the black clad layer 53 is strong, the resolution is not partially lowered by the peeling of the black clad layer 53.

(Other embodiments)
As described above, the present invention has been described according to the above-described embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the description of the embodiment of the present invention already described, the austenitic stainless steel is exemplified as a base material of the low elongation mesh fabric used for the screen printing plate, but instead of the austenitic stainless steel, A low elongation metal wire may be formed using martensitic stainless steel or tungsten as a base material of a low elongation mesh fabric.

  In the description of the embodiment of the present invention, the plain weave low-stretch mesh fabric has been described as an example, but instead of the plain weave low-stretch mesh fabric, a twill weave low-stretch mesh fabric is used. Also good. Furthermore, a calendar mesh, a 3D mesh (see, for example, Japanese Patent No. 3710428), a solid mesh (see, for example, Japanese Patent No. 4143681), and a one-side calendar mesh in which the intersection of warp and weft is crushed. Other weaving methods such as Japanese Patent Application Laid-Open No. 2009-090519 may be adopted as the weaving method for the low elongation mesh fabric.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description of the embodiments.

DESCRIPTION OF SYMBOLS 1 ... Muffle furnace 2 ... Outer shell 3 ... Heater 4 ... Inner container 5 ... Gas introduction pipe 6 ... Exhaust pipe 7 ... Motor 8 ... Fan 11 ... Metal mesh fabric 13 ... Vacuum pump 14 ... Exhaust gas treatment device 15, 16 ... Cylinder 17 ... Flow meter 18 ... Valve 51 ... Core 52 ... Hardened layer 53 ... Black clad layer

Claims (9)

A metal mesh fabric having a structure in which warp yarns and weft yarns made of metal wire are woven so as to intersect each other, each of the warp yarns and the weft yarns,
A core made of austenitic stainless steel;
Provided so as to surround the core portion, the austenitic stainless steel as a base material, a hardened layer in which carbon diffuses and penetrates into the base material,
Surrounding the hardened layer, a combination of element A and element B different from element A is selected from any of Fe, Cr, and Ni, and carbide and an oxide represented by the chemical formula AB ₂ O ₄ And a black clad layer.   The metal mesh fabric according to claim 1, wherein the ratio of the thickness of the hardened layer to the radius of the metal wire is a value within a range of 10% to 60%.   The thickness of the said black clad layer is a value within the range of 0.1 micrometer-1.1 micrometer, The metal mesh fabric of Claim 1 or 2 characterized by the above-mentioned.   Concavities and convexities in which the surface of the black clad layer has a convex portion with a width of 0.3 to 1.5 μm and a length of 0.5 to 2.5 μm arranged continuously at random along the length direction of the metal wire. The metal mesh fabric according to any one of claims 1 to 3, characterized by comprising:   In each intersection of the warp and the weft, the hardened layer and the black clad layer surrounding the hardened layer are also formed at the intersection where the warp and the weft contact. The metal mesh fabric according to any one of claims 1 to 4. Formwork,
A metal mesh fabric woven in such a manner that warp yarns and weft yarns made of metal wire cross each other, and each of the warp yarns and the weft yarns,
A core portion made of austenitic stainless steel, provided to surround the core portion, the austenitic stainless steel as a base material, a hardened layer in which carbon diffuses and penetrates into the base material, and surrounds the hardened layer, element A combination of A and an element B different from the element A is selected from any one of Fe, Cr, and Ni, and has a black clad layer containing a carbide and an oxide represented by the chemical formula AB ₂ O _4. A screen printing plate characterized by the above.   7. The screen printing plate according to claim 6, wherein the ratio of the thickness of the hardened layer to the radius of the metal wire is a value within a range of 10% to 60%.   8. The screen printing plate according to claim 6, wherein the black clad layer has a thickness in a range of 0.1 μm to 1.1 μm.   Concavities and convexities in which the surface of the black clad layer has a convex portion with a width of 0.3 to 1.5 μm and a length of 0.5 to 2.5 μm arranged continuously at random along the length direction of the metal wire. The screen printing plate according to any one of claims 6 to 8, wherein