JP2018103444A - Base plate for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base plate for printing having a plate surface easy to remove ink.SOLUTION: The base plate for printing is composed of ceramic, and has a concavity on a plate surface. The plate surface has an arithmetic average roughness Ra found from a roughness curve of not greater than 0.03 μm, and has a projection trough depth Rvk found from the roughness curve of not greater than 0.5 μm. Since the disclosed base plate for printing is easy to remove ink on account of such configuration, there is little risk of a printed letter and a figure bleeding, and of ink attaching to another place than a printing region.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a printing substrate.

  Pad printing is widely used in various fields because it enables printing of characters and figures on all surfaces such as uneven surfaces and curved surfaces. In this pad printing, the object is printed by the following procedure. First, a printing substrate having an arbitrarily shaped recess on the plate surface is prepared. Next, ink is applied to the plate surface of the printing substrate. Next, using a squeegee or the like, excess ink is removed so that no ink remains except in the recesses. Next, the ink in the recess is primarily transferred to the silicon pad by pressing the silicon pad against the plate surface of the printing substrate. Next, by pressing the silicon pad against the object, the ink of the silicon pad is secondarily transferred to the object to be printed, and printing is performed.

Here, as a material for the printing substrate, ceramics are used from the viewpoint of processability and chemical resistance. For example, Patent Document 1 discloses a composite firing of Si ₃ N ₄ and at least one inorganic material selected from the group consisting of MgO, Al ₂ O ₃ , Y ₂ O ₃ , AlN, B ₄ C, and SiC. It is disclosed that it is composed of a ligation.

JP 2001-130154 A

  When excess ink is removed, if ink remains on the periphery of the printing plate other than the inside of the concave portion of the printing substrate, characters or figures to be printed are blurred. Further, if ink remains on the printing plate, a printing error occurs, and the printing object does not become a good product.

  The present disclosure has been devised in view of such circumstances, and an object thereof is to provide a printing substrate having a printing plate on which ink can be easily removed.

  The printing substrate of the present disclosure is a printing substrate made of ceramics and having a concave portion on the plate surface, and the plate surface has an arithmetic average roughness Ra obtained from a roughness curve of 0.03 μm or less and a roughness. The protruding valley depth Rvk obtained from the curve is 0.5 μm or less.

  The printing substrate according to the present disclosure is easy to remove ink.

It is the schematic which shows an example of the member for printing of this indication.

  Hereinafter, the printing substrate of the present disclosure will be described in detail with reference to FIG.

The printing substrate 10 of the present disclosure is made of ceramics and has a recess 2 in the plate surface 1. Here, as the ceramic, for example, aluminum oxide ceramics, silicon carbide ceramics, cordierite ceramics, zirconium oxide ceramics, silicon nitride ceramics, aluminum nitride ceramics, mullite ceramics, or the like can be used. If the ceramic is an aluminum oxide ceramic, since the raw material cost is low and the processing is easy, the printing substrate 10 can be manufactured at a lower cost than other materials.

Here, for example, aluminum oxide ceramics are ceramics mainly composed of aluminum oxide. Moreover, a main component means the case where 70 mass% or more of aluminum oxide is contained among 100 mass% of all the components which comprise ceramics. And the material of the printing substrate 10 of this indication can be confirmed with the following method. First, measurement is performed using an X-ray diffractometer (XRD), and the obtained 2θ (2θ is a diffraction angle) value is identified with a JCPDS card. Next, quantitative analysis of each component is performed using an ICP (Inductively Coupled Plasma) emission spectroscopic analyzer (ICP) or a fluorescent X-ray analyzer (XRF). In XRD, if the presence of aluminum oxide is confirmed, and the content converted from aluminum content measured by ICP or XRF to aluminum oxide (Al ₂ O ₃ ) is 70% by mass or more, it is an aluminum oxide ceramic. . The same applies to other ceramics.

  The plate surface 1 is a region where ink is applied on the surface of the printing substrate 10. Moreover, the recessed part 2 should just be arbitrary shapes and magnitude | sizes according to the character and figure to print.

  The plate surface 1 of the printing substrate 10 of the present disclosure has an arithmetic average roughness Ra obtained from the roughness curve of 0.03 μm or less and a protruding valley depth Rvk obtained from the roughness curve of 0.5 μm. It is as follows.

  Here, the arithmetic average roughness Ra obtained from the roughness curve refers to a value defined in JIS B 0601 (2013). The protruding valley depth Rvk obtained from the roughness curve is defined in JIS B 0671-2 (2002) and is defined as follows. First, in the central portion of the load curve including 40% of the measurement points of the roughness curve, the straight line where the dividing line of the load curve drawn with the difference in load length ratio being 40% is the most gentle is defined as the equivalent line. . Next, a core portion is defined between two height positions where the equivalent straight line intersects the vertical axis at the load length ratios of 0% and 100%. In the roughness curve, the average depth of the protruding valley portion below the core portion is the protruding valley depth Rvk.

  By satisfying the above configuration, the unevenness on the plate surface 1 is small and the depth of the protruding valley portion is shallow. Therefore, by using a squeegee or the like, excess ink accumulated in the valley portion of the plate surface 1 is removed. Easy to remove. Therefore, since the printing substrate 10 of the present disclosure is easy to remove ink, it is possible to reduce a possibility that a character or a graphic to be printed blurs or a printing mistake in which ink adheres to a region other than the printing region occurs.

  Further, the plate surface 1 in the printing substrate 10 of the present disclosure may have a maximum valley depth Rv obtained from a roughness curve of 0.3 μm or less. Here, the maximum valley depth Rv obtained from the roughness curve is defined in JIS B 0601 (2013), and only the reference length is extracted from the roughness curve in the direction of the average line, and the valley portion at the reference length is extracted. Indicates the maximum depth.

  If such a configuration is satisfied, the plate surface 1 of the printing substrate 10 of the present disclosure has a shallow depth of the valley where excess ink is most likely to remain, and therefore, it becomes easier to remove excess ink.

  Further, the plate surface 1 of the printing substrate 10 of the present disclosure may have a skewness Rsk obtained from a roughness curve of −2.5 or more and 0.5 or less. Here, the skewness Rsk obtained from the roughness curve is an index indicating the ratio of the peak portion to the valley portion with respect to the average height of the roughness as the center line. If the skewness Rsk is less than 0, it indicates that the region that is a peak is larger than the valley. On the other hand, if the skewness Rsk is greater than 0, it indicates that the region that is the valley is larger than the mountain.

  If such a configuration is satisfied, the plate surface 1 of the printing substrate 10 according to the present disclosure has a width of a trough portion, which makes it difficult for excess ink to accumulate and easily scrapes excess ink using a squeegee or the like. Therefore, it becomes easier to remove excess ink.

  Further, the plate surface 1 in the printing substrate 10 of the present disclosure may have a load length ratio Rmr at a cutting level of 20% of 10% or less. Here, the load length ratio Rmr obtained from the roughness curve is the reference length extracted in the direction of the average line from the roughness curve, and the roughness curve of this extracted portion was cut at a cutting level parallel to the peak line. The ratio of the sum of the cut lengths obtained sometimes to the reference length is expressed as a percentage. Here, the cutting level is a percentage of the ratio of the height to the maximum height (the sum of the maximum peak height and the maximum valley depth indicated in JIS B 0601 (2013)) in the reference length. It is. That is, the load length ratio Rmr at the cutting level 0% is 0%, and the load length ratio Rmr at the cutting level 100% is 100%.

  If such a configuration is satisfied, since the plate surface 1 of the printing substrate 10 of the present disclosure has few protruding ridges, squeegees and the like can easily enter the valleys, and more excess ink is removed. It becomes easy.

  Here, the arithmetic average roughness Ra, the maximum valley depth Rv, the skewness Rsk, and the load length ratio Rmr in the plate surface 1 of the printing substrate 10 of the present disclosure are based on JIS B 0601 (2013), and the protruding valley portion The depth Rvk can be obtained by measuring in accordance with JIS B 0671-2 (2002). As measurement conditions, for example, the measurement length is set to 1.0 mm, the cutoff value is set to 0.25 mm, and the scanning speed of a stylus having a stylus radius of 2 μm may be set to 0.15 mm / second. Then, it is only necessary to measure at least five places on the printing plate 1 and obtain the average value.

  Hereinafter, a method for manufacturing the printing substrate 10 of the present disclosure will be described.

  First, a sintering aid, a binder, a solvent, a dispersing agent, and the like are appropriately added to and mixed with powders of main component materials (aluminum oxide, silicon carbide, etc.) to prepare a slurry. Then, the slurry is spray-dried by a spray-drying granulation method (spray-drying method) and granulated to produce granules, and the obtained granules are formed by a roll compaction method to obtain a ceramic green sheet.

  Here, the surface properties of the surface of the roll used in the roll compaction method are transferred to the surface of the ceramic green sheet. Therefore, in obtaining the plate surface 1 having an arithmetic average roughness Ra of 0.03 μm or less and a protruding valley depth Rvk of 0.5 μm or less, the amount of polishing by surface treatment such as mirror polishing after firing was taken into consideration. A ceramic green sheet may be produced using a roll having surface properties. In the printing plate 1, the maximum valley depth Rv is set to 0.3 μm or less, the skewness Rsk is set to −2.5 or more and 0.5 or less, or the load length ratio Rmr at a cutting level of 20% is set to 10% or less. The same applies to the case.

Next, the ceramic green sheet is punched with a mold according to the shape of the product or laser processed to obtain a molded body. In addition, it is good also as a molded object with desired thickness by laminating | stacking the green sheet obtained as needed.

  Next, after drying and degreasing the molded body to produce a degreased body, the sintered body is obtained by firing at a firing temperature and a firing atmosphere suitable for the main component raw material.

  And after mirror-polishing the obtained sintered compact, the printing substrate 10 of this indication is obtained by forming the recessed part 2 in the plate surface 1 by laser processing etc. FIG.

  Examples of the present disclosure will be specifically described below, but the present disclosure is not limited to these examples.

  On the printing plate, samples (printing substrates) having different arithmetic average roughness Ra and protruding valley depth Rvk were prepared, and the ease of ink removal was evaluated.

First, aluminum oxide powder, which is a main raw material, and silicon oxide powder, magnesium oxide powder, and calcium oxide powder as a sintering aid are prepared. In each of the samples after firing, 96% by mass of Al ₂ O ₃ and SiO 2 _The aluminum oxide powder and the sintering aid were weighed so that ₂ was 2.5 mass%, MgO was 1.2 mass%, and CaO was 0.3 mass%.

  Next, 4 parts by mass of a water-soluble acrylic resin binder and 100 parts by mass of a solvent are mixed in and stirred in a stirrer for a total of 100 parts by mass of the aluminum oxide powder and the sintering aid. Obtained.

  Next, this slurry was spray-dried by a spray-drying granulation method and granulated to produce a granule, and then the obtained granule was molded by a roll compaction method to obtain a ceramic green sheet.

  Here, the surface properties of the surface of the roll used in the roll compaction method, taking into account the amount of polishing by mirror polishing after firing, the arithmetic average roughness Ra and protruding valley depth shown in Table 1 for the plate surface of each sample Rvk.

  Next, a plurality of ceramic green sheets obtained were laser-processed and then laminated, and a molded body was obtained so as to have a plate shape having a width of 50 mm, a length of 100 mm, and a thickness of 8 mm after firing.

  Next, this molded body was dried and degreased to produce a degreased body, and then fired at 1550 ° C. for 2 hours in an air atmosphere to obtain a sintered body.

  Then, the obtained sintered body was mirror-polished, and then a recess having the shape shown in FIG. 1 was formed by laser processing to obtain each sample.

  Next, for each of the obtained samples, using a contact-type surface roughness meter, based on JIS B 0601 (2001) and JIS B 0671-2 (2002), the arithmetic average roughness Ra and the valley depth in the printing plate Rvk was measured. As measurement conditions, the measurement length is 1.0 mm, the cutoff value is 0.25 mm, the scanning speed of the stylus with a stylus radius of 2 μm is set to 0.15 mm / sec, and measurement is performed at five locations on the plate surface. The average value was calculated.

In addition, using each sample, the ease of ink removal on the plate surface of each sample was evaluated by the following method. First, after applying ink to the plate surface of each sample, use a squeegee to remove the plate surface 1
The ink was removed by reciprocating. Thereafter, the ink residues on the plate surface of each sample were visually compared, and the samples were ranked in order from the sample with the least ink residue. Here, the sample with the least ink residue was ranked first, and the sample with the most ink residue was ranked lowest (fourth). The results are shown in Table 1.

  As shown in Table 1, sample no. Since the ranks 3 and 4 are high, the arithmetic average roughness Ra is 0.03 μm or less and the protruding valley depth Rvk is 0.5 μm or less on the printing plate, so that ink can be easily removed. I understood.

  Next, samples having different maximum valley depths Rv on the printing plate were prepared, and the ease of ink removal was evaluated.

  In addition, as a manufacturing method, the surface property of the surface of the roll used in the roll compaction method takes the polishing amount by mirror polishing after firing into consideration, and the plate surface of each sample has the maximum valley depth Rv shown in Table 2. Except that the sample was changed as described above, the sample N o. 4 was the same as the manufacturing method. Sample No. 5 shows the sample No. of Example 1. Same as 4.

  For each sample obtained, the maximum valley depth Rv was measured on the printing plate, and the measurement conditions were the same as in Example 1. In addition, the ease of ink removal was evaluated in the same manner as in Example 1.

  The results are shown in Table 2. The ranking is made by comparing only the samples shown in Table 2.

  As shown in Table 2, sample no. Sample No. 5 The ranking of 6 and 7 was high. From this result, it was found that if the maximum valley depth Rv is 0.3 μm or less on the printing plate, it is easier to remove the ink.

  Next, samples having different skewness Rsk on the printing plate were prepared, and the ease of ink removal was evaluated.

As a production method, the surface properties of the surface of the roll used in the roll compaction method are changed so that the plate surface of each sample has the skewness Rsk shown in Table 3 in consideration of the polishing amount by mirror polishing after firing. Except that, the sample No. 2 of Example 2 was used. 7 was the same as the manufacturing method. Sample No. 12 is sample No. 2 of Example 2. Same as 7.

  And about each obtained sample, skewness Rsk was measured in the plate surface, but the measurement conditions were the same as in Example 1. In addition, the ease of ink removal was evaluated in the same manner as in Example 1.

  The results are shown in Table 3. The ranking is made by comparing only the samples shown in Table 3.

  As shown in Table 3, Sample No. Compared to Samples 8 and 12, Sample No. The ranking of 9-11 was high. From this result, it was found that if the skewness Rsk is −2.5 or more and 0.5 or less on the printing plate, it is easier to remove the ink.

  Next, samples having different load length ratios Rmr with a cutting level of 20% were prepared on the plate surface, and the ease of ink removal was evaluated.

  In addition, as a preparation method, the surface property of the surface of the roll used in the roll compaction method is taken into consideration the amount of polishing by mirror polishing after baking, and the plate length of each sample is a load length with a cutting level of 20% shown in Table 4 The sample N o. 10 was the same as the manufacturing method. Sample No. 13 is sample No. of Example 3. 10 is the same.

  And about each obtained sample, the load length rate Rmr of the cutting level 20% was measured in the plate surface, but it was the same as that of Example 1 about the measurement conditions. In addition, the ease of ink removal was evaluated in the same manner as in Example 1.

  The results are shown in Table 4. The ranking is made by comparing only the samples shown in Table 4.

As shown in Table 4, Sample No. Compared to sample No. 13, sample no. The ranking of 14 and 15 was high. From this result, it was found that if the load length ratio Rmr at the cutting level of 20% is 10% or less on the printing plate, the ink can be more easily removed.

1: Plate surface 2: Concave portion 10: Print substrate

Claims (5)

Made of ceramics,
A printing substrate having a depression on the printing plate,
The printing plate has an arithmetic average roughness Ra determined from a roughness curve of 0.03 μm or less and a protruding valley depth Rvk determined from the roughness curve of 0.5 μm or less.   2. The printing substrate according to claim 1, wherein the plate surface has a maximum valley depth Rv obtained from a roughness curve of 0.3 μm or less.   3. The printing substrate according to claim 1, wherein the plate surface has a skewness Rsk obtained from a roughness curve of −2.5 or more and 0.5 or less.   4. The printing substrate according to claim 1, wherein the plate surface has a load length ratio Rmr at a cutting level of 20% of 10% or less. 5.   The printing substrate according to claim 1, wherein the ceramic is an aluminum oxide ceramic.

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