JP2005131869A - Original plate for pad printing and printed article obtained by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate for pad printing whereby a rounded printed surface is obtained. <P>SOLUTION: In regard to the original plate for pad printing wherein a recess shaped in conformity with the shape of a character, a numeral, a pattern or the like to be printed is provided by engraving, a resin 52 such as an epoxy resin having good releasability from ink is poured a little into corners of the bottom of the recess 50a formed by a chemical etching method or the like, so as to be formed in a curved shape 52a, 52b, and the resin 52 is cured to be adhered and fixed to the original plate 50. The depth of the recess 50a is set to be in the range of about 20-30 μm. Besides, the resin 52 is colored. The releasability of the ink 51 from the recess 50a is improved, while the ink 51 sticks much to a pad 20 and the amount of the ink 51 to be transferred to a printing object 60 is increased. When the amount of the ink 51 is large, the shape of a printed surface is rounded by the working of surface tension. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a printing original plate used when performing pad printing.

  Conventionally, pad printing methods are often used for various nameplates and display plates that require extremely strict printing positional accuracy. The pad printing method is also used for printing very fine characters such as clock dials and dial indicator dials, numbers, scale lines, and patterns.

  This pad printing method takes the steps shown in FIG. 4 for printing. 4A and 4B are explanatory diagrams for explaining the pad printing process. FIG. 4A is an enlarged cross-sectional view of a main part showing a state in which printing ink is buried in a recessed portion that is engraved, and FIG. 4B is a diagram in which ink is attached to the pad. The principal part expanded sectional view which shows a state, (c) The figure has shown the principal part enlarged sectional view which shows the state which transferred the ink to the to-be-printed material. First, a material such as steel or glass is used as the printing plate material, and the surface is flattened, and then a concave portion with a shape that matches the shape of characters, numbers, patterns, etc. to be printed on the surface by a chemical etching method or the like. An original 10 for printing is manufactured by engraving 10a. Then, the printing ink 11 is placed on the recessed portion 10a that is engraved, and the surface of the original 10 is scraped with a metal blade to remove excess ink (FIG. (A)). Next, the soft hemispherical pad 20 is pressed against the surface of the original plate 10, and the ink 11 in the recess 10a is adhered to the surface of the pad 20 (FIG. 5B). Next, the pad 20 to which the ink 11 is adhered is pressed against the surface of the printing material 30 to transfer the ink 11 to the surface of the printing material 30 (FIG. (C)).

  In general, a chemical etching method is used as a means for forming the recesses in the original plate. However, the etching solution varies depending on the material of the original plate. A ferric chloride solution is used for an original plate of a brass material or an iron material, and a hydrofluoric acid (mixed solution of hydrogen fluoride and sulfuric acid) solution is used for an original plate of a glass material (hereinafter referred to as a glass original plate).

  The printing quality of the pad printing method is greatly influenced by the roughness accuracy of the surface of the recess formed in the original plate. Further, the roughness accuracy of the surface of the concave portion varies depending on the material used for the original plate. In the case of the glass original plate, the roughness of the concave surface is relatively small, and in the case of the brass material, the roughness is relatively large. When the roughness of the surface of the recess is large, the cut between the surface of the recess and the ink deteriorates, and the amount of ink remaining in the recess increases. Accordingly, the amount of ink attached to the pad is reduced. If the amount of ink adhering to the pad is small, the amount of ink transferred is also small, and the printed surface becomes thin. Therefore, in order to increase the amount of ink attached to the pad as much as possible, it is desirable to make the surface roughness of the concave surface as small as possible and uniform.

  Therefore, there is a technique disclosed in Patent Document 1 below as a technique for accurately forming the concave portion in the original plate.

JP-A-10-250249,

  FIG. 5 is a cross-sectional view of the main part of the original plate disclosed in Patent Document 1, in which an ink reservoir 2 is formed on the original plate 1 made of a metal material. According to Patent Document 1, by forming the ink reservoir 2 by electric discharge machining, the roughness of the bottom surface of the ink reservoir 2 can be made smaller than that of the chemical etching method and can be finished with uniform accuracy. Has been. And it is supposed that the printing surface of a uniform film thickness is obtained by this.

  However, it is difficult to form electrodes for electrical discharge machining for those with very small specifications such as printed characters, fine scale lines, etc., and complicated shapes such as patterns and indicators, and rely on chemical etching methods. I must. Moreover, the electrical discharge machining method cannot be used for the glass original plate. Have problems such as.

  In addition, when a concave portion is engraved by a chemical etching method using a glass original plate, the roughness of the surface of the concave portion can be reduced, but conversely, the permeability is improved and the engraved portion of the concave portion is difficult to see. Thus, there is a problem that it is difficult to determine what characters are engraved.

  FIG. 6 shows an enlarged cross-sectional view of the main part when the glass original plate is subjected to chemical etching. The depth is 23 μm and the width is 0.6 mm (drawn by changing the vertical and horizontal enlargement ratios). The figure which formed the recessed part of FIG. As can be seen from the figure, when the glass original plate 40 is used, both corners 40a1 and 40a2 of the bottom surface of the recess 40a tend to be deepened by etching. For this reason, the releasability of the ink buried in the concave portion is further deteriorated, and there arises a problem that a sufficient amount of ink does not adhere to the pad. For this reason, in the case where the concave portion is formed by the chemical etching method, a sufficient amount of ink cannot be attached to the pad. Therefore, the printed surface becomes a flat surface, and the rounded surface There was a problem that a certain printed surface could not be obtained easily. This is true not only for glass masters but also for metal masters.

  Furthermore, since the printing ink before drying / firing is required to have an appropriate fluidity, if the ink corresponding to the cross-sectional shape of the concave portion of the glass original plate is attached to the pad, the ink is applied when the pad is pressed against the printing surface. However, if the depth of the concave portion is set to be small for the purpose of preventing this, blurring occurs in the case of a relatively large printing area, i.e. There was a problem that printing ink was not placed in a pinhole shape.

  The present invention has been made in view of the above problems, and an object of the present invention is to obtain a printing original plate from which a round printing surface can be obtained. Another object is to obtain an original plate in which engraved characters and the like can be easily distinguished.

  As a means for achieving the above object, the invention described in claim 1 of the present invention is the pad printing original plate in which the concave portion having a shape matching the shape of characters, numbers, patterns, etc. to be printed is engraved. The corners are formed in an R shape.

  The invention according to claim 2 of the present invention is characterized in that the pad printing original plate is formed of glass.

  The invention according to claim 3 of the present invention is characterized in that the pad printing original plate is formed of metal.

  According to a fourth aspect of the present invention, the depth of the concave portion is approximately 20 to 30 μm.

  The invention according to claim 5 of the present invention is characterized in that the R shape at the bottom corner of the recess is formed by pouring resin.

  The invention according to claim 6 of the present invention is characterized in that the resin is a resin having good releasability such as an epoxy resin.

  The invention according to claim 7 of the present invention is characterized in that the resin is colored.

  The invention according to claim 8 of the present invention is characterized in that the concave portion of the pad printing original plate is formed by an etching method, an electric discharge machining method, or a convex blade whose tip corresponds to the concave portion.

  Moreover, the printed article according to claim 9 of the present invention performs pad printing using the pad printing original plate according to any one of claims 1 to 6, and the printed surface has a round surface shape. It is characterized in that it is formed.

  According to the first aspect of the present invention, by forming the bottom corners of the recesses in an R shape, the releasability of the printing ink embedded in the recesses is improved, and the ink is easily released. The amount of ink can be attached to the pad.

  According to the second aspect of the present invention, when the pad printing original plate is made of glass, the surface roughness of the glass material becomes smaller than that of the metal material when chemical etching is performed. Sexuality is improved.

  Further, according to the invention of claim 3, by forming the pad printing original plate with metal, in addition to chemical etching as described later, an electric discharge machining method, and further, a convex shape whose tip corresponds to the original concave portion shape By moving the shape of the rotary cutter in a desired shape and locus by a numerical control technique, an R shape at the bottom corner of the recess can be formed.

  According to the invention described in claim 4, by setting the depth of the concave portion to approximately 20 to 30 μm, the ink amount becomes appropriate to make the printed surface round, and a round surface shape is obtained. . If it is shallower than this, the amount of ink is small and the printing surface becomes flat. Further, even if the depth becomes deeper than this, the amount of ink adhering to the pad does not change, and the effect does not increase. On the contrary, the deeper the etching, the more the shape of the recess will collapse and it will not be possible to fit within the specified dimensions.

  According to the fifth aspect of the present invention, the bottom corners of the recesses can be easily finished in an R shape by pouring resin. In addition, the R-shaped surface can be cleaned without unevenness.

  Further, according to the invention described in claim 6, when a resin having good releasability such as epoxy resin is used as the resin, the releasability between the resin and the ink is improved, and the ink is easily separated from the concave portion. Adheres to the pad.

  Further, according to the invention described in claim 7, by coloring the resin, the shapes of letters, numbers, patterns and the like engraved on the printing original plate can be seen well, and the engraved shapes Can be immediately and accurately identified, and the pad can be prevented from being set incorrectly.

  Further, according to the invention described in claim 8, in connection with the content described in claim 3, the method for forming the recesses of the pad printing original plate is not limited to the etching method, and the discharge is performed by making the original plate material metal. By moving the rotary blade having a convex shape whose tip corresponds to the concave shape of the original plate along a desired shape and locus, an R shape at the bottom corner of the concave portion of the original plate can be formed.

  According to the seventh aspect of the present invention, a printed article with a rounded printing surface has a high-quality appearance because the printing surface looks beautiful and a three-dimensional appearance also appears.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 shows an enlarged cross-sectional view of the main part of the pad printing original plate according to the first embodiment of the present invention. FIG. 2 is an explanatory view for explaining the state up to printing using the original plate of the present invention. FIG. 2 (a) is an enlarged cross-sectional view of the main part showing a state in which the printing ink is buried in the original plate, and FIG. The principal part expanded sectional view which shows the state which made the ink adhere, (c) The figure has shown the principal part expanded sectional view which shows the state after printing. FIG. 3 is an enlarged cross-sectional view of a main part of a pad printing original plate according to a second embodiment of the present invention.

  As shown in FIG. 1, the pad printing original plate 50 according to the first embodiment of the present invention has a recess 50a having a shape matching a shape such as characters, numbers, and patterns to be printed at a predetermined depth h by chemical etching. It is etched and engraved. The resin 52 having a good releasability is slightly poured into the corners at both corners of the bottom of the recess 50 a to form R shapes 52 a and 52 b with the resin 52. Since these corners are corner portions, the R shapes 52a and 52b are naturally formed by the action of surface tension just by pouring a small amount of resin.

  As the original plate 50, a glass original plate or a metal original plate such as brass or iron can be selected. The recess 50a is formed by a chemical etching method, and the etching solution is appropriately selected depending on the material of the original 50 as described above. Here, the depth h of the recess 50a is preferably in the range of about 20 to 30 μm. The resin 52 is poured by a method of dropping with a dropper or the like, but it is preferable to use a resin having good releasability from the printing ink. Examples of the resin having good releasability include an epoxy resin and a Teflon (R) resin. After the resin 52 is dropped on the corner corner portion, the resin 52 is subjected to heat treatment to be cured and bonded. In this embodiment, a two-component mixed type epoxy resin is used, and a colorant such as a dye is added at the time of mixing, followed by a heat treatment at 150 ° C. for 30 minutes to be cured and bonded. Epoxy resin also has an excellent effect on releasability due to its glossiness. The resin 52 is colored. The reason for coloring is to improve the visibility of the shape of the recess 50a, and the color tone is not particularly limited. It is better to select a desired color such as red, blue or green. When a metal original is used, it is preferable to select a color that can be clearly distinguished from the metal color of the original.

  In this embodiment, Cemedine (R) No. 1565 having relatively high fluidity was used as the epoxy resin. This is because a high-viscosity epoxy resin does not reach the details in scale lines or complicated shapes. For patterns and characters with a relatively large printing area, using a highly viscous epoxy resin such as Araldite (R) standard allows a larger R (roundness) at the bottom corner of the pad printing original plate recess. It has been confirmed by experiments that the effect of the present invention is also great. . A thermosetting resin such as epoxy once has a low viscosity when heated and dried. That is, since the fluidity is temporarily increased, it has been confirmed by experiments that an appropriate roundness necessary for the present invention is formed in the corner of the bottom of the recess by the surface tension.

  Next, the state up to printing when the original 50 of the present invention is used will be described with reference to FIG. (A) The figure has shown the state which filled the ink 51 for printing in the recessed part 50a of the original 50, and scraped with the blade, and removed the excess ink. The ink 51 adheres to a part of the side surface, a part of the bottom surface, and the R-shaped surface of the resin 52 of the recess 50a. Next, the pad 20 is pressed against the concave portion 50a, and the ink 51 is attached to the pad 20 and lifted. (B) The figure shows the adhesion state of the ink 51 when the pad 20 is lifted. When the pad 20 is lifted from the recess 50a, the bottom corner of the recess is finished in an R shape with a resin having good releasability, so that the ink 51 is easily released from the recess 50a. For this reason, most of the ink 51 in the recess 50 a adheres to the pad 20 and rises together with the pad 20. Ink 51 does not remain in the recess 50a. Since the amount of the ink 51 lifted by adhering to the pad 20 is large, it changes to a round shape due to the effect of surface tension. Next, when the pad 20 with the ink 51 is pressed against a predetermined position of the substrate 60 and the pad 20 is immediately lifted, the ink 51 spreads to one side when the pad 20 is pressed, but the pad is lifted. However, a large amount of ink remains attached to the substrate 60 while being pulled upward due to the action of the force. If the amount of ink remaining on the substrate 60 side is large, the ink 51 changes to a rounded surface shape as shown in FIG.

  Whether or not the printed surface has a rounded shape depends on whether the amount of ink is large or small. When the amount is small, the printing surface becomes flat, and when the amount is large, a rounded printing surface is obtained. The amount of ink from which this round printing surface is obtained is determined by the depth h of the recess 50a of the original 50. As a result of various experiments, the depth h can be set as a preferable range of approximately 20 to 30 μm. If the depth is smaller than this, the amount of ink transferred to the substrate 60 is reduced, and a round printing surface cannot be obtained. Further, even if the depth is deeper than this, there is a limit to the amount of ink per unit area that adheres to the pad 20, and therefore the amount of ink that adheres beyond that cannot be increased.

  A glass original plate or a metal original plate such as brass or iron can be selected as the original plate 50, but in the case of a glass original plate, the surface roughness by chemical etching can be suppressed to about 0.5 μm. On the other hand, the brass original plate has a chemical etching surface roughness of 1 to 2 μm, and the glass original plate gives better results in terms of ink releasability. Further, although a super hard material or the like is used for the blade that scrapes the ink, the metal original plate is easily damaged and is inferior to the glass original plate in terms of life.

  However, in the case of a metal original plate, a concave portion formed in the original plate is subjected to an R shape with a certain dimension at the bottom corner of the concave portion by an electric discharge machining method or an end mill process in which a necessary R shape is applied to the tip as described later. There is also an advantage that makes it possible.

  Next, what is shown in FIG. 3 is an enlarged cross-sectional view of a main part of a pad printing original plate according to a second embodiment of the present invention. The pad printing original plate 70 uses a brass material. Since the characters to be printed are large and have a relatively simple shape, an electrode is made of a copper material and is subjected to electric discharge machining to form a recess 70a. Further, the electric discharge machining surface is further polished to a mirror finish. R shapes 70a1 and 70a2 are formed at both corners of the bottom of the recess 70a by attaching an R having the same shape as the R shapes 70a1 and 70a2 formed at the bottom corner of the recess 70a to the tip of the electrode, and performing electric discharge machining. Can do. The depth of the recess 70a is set in a range of approximately 20 to 30 μm, as in the first embodiment.

  If the shape of the concave portion is within a range where the electrode can be formed, the concave portion can be engraved by an electric discharge machining method. Polishing of the electric discharge machining surface is performed to further improve the releasability, and it is not necessary to polish unless the releasability is particularly bad.

  When the original plate 70 is made of a metal such as brass or iron, a well-known NC milling process is performed using a rotary cutting blade such as an end mill whose tip has a required R-shaped dimension, for example, R 0.02 to 0.1 mm. By setting the depth and shape of the cutting tool by programming with a machine and forming patterns, characters, and scale lines, it becomes possible to apply an R shape to the bottom corners of all cut recesses.

  As described above in detail, by forming the bottom corners of the recesses formed in the original plate in an R shape, the ink releasability is improved, and the amount of ink transferred to the printing material can be increased. As a result, it is possible to obtain a rounded and clear printed surface without ink bleeding during printing. The larger the R shape formed at the bottom corner of the recess, the better the releasability. And it is good to form R shape with a uniform dimension over a round.

A printed article subjected to pad printing using the original plate of the present invention has a round-shaped printed surface having a rounded printing surface. The rounded printed surface looks beautiful and has a three-dimensional appearance. And it gives a sense of luxury. The present invention can be applied to the printing of timepiece dials and display boards for various instruments, and the printing of cellular phones and various electronic devices. Also, it can be applied over a wide range such as various nameplates, seals, and other decorative articles.
In addition, the ink adhering to the pad was rounded according to the shape of the recess, and even when the pad was pressed against the printing surface, the ink did not protrude much, and characters and scale lines with clear outlines without bleeding were printed. Clocks and instruments having a dial plate and a display plate can be provided.

  The present invention relates to a pad printing original plate and a printed article printed using the same. It can be used for printing display boards for various instruments, various nameplates and seals, external parts of various electronic devices, and various decorative parts.

It is a principal part expanded sectional view of the original plate for pad printing which concerns on 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing explaining the state until printing using the original plate of this invention, (a) A figure is a principal part expanded sectional view which shows the state which filled the printing ink in the original plate, (b) The figure adheres ink to a pad. The principal part expanded sectional view which shows the made state, (c) FIG. 5: is a principal part expanded sectional view which shows the state after printing. It is a principal part expanded sectional view of the original plate for pad printing which concerns on 2nd Embodiment of this invention. It is explanatory drawing explaining a pad printing process, (a) A figure is a principal part expanded sectional view which shows the state which stored the printing ink in the recessed part which was engraved, (b) A figure shows the state which made the ink adhere to a pad. The principal part expanded sectional view, (c) figure is a principal part expanded sectional view which shows the state which transferred the ink to the to-be-printed material. It is principal part sectional drawing of the original plate shown by patent document 1. FIG. It is a principal part expanded view of the place which gave the chemical etching to the glass original plate.

Explanation of symbols

20 Pad 50, 70 Pad printing master
50a, 70a Recess 51, Ink 52 Resin
52a, 52b R shape
60 Substrate 70a1, 70a2 R shape

Claims (9)

A pad printing original plate in which a concave corner having a shape matching a shape of a character, number, pattern, or the like to be printed is engraved, and the bottom corner of the concave portion is formed in an R shape. 2. The pad printing original plate according to claim 1, wherein the pad printing original plate is formed of glass. 2. The pad printing original plate according to claim 1, wherein the pad printing original plate is made of metal. The original plate for pad printing according to claim 1, 2 or 3, wherein the depth of the recess is approximately 20 to 30 µm. 5. The pad printing original plate according to claim 1, wherein the R shape at the bottom corner of the concave portion is formed by pouring resin. The pad printing original plate according to claim 5, wherein the resin is a resin having good releasability such as an epoxy resin. 7. The pad printing original plate according to claim 5, wherein the resin is colored. The concave portion of the original plate for pad printing is formed by an etching method, an electric discharge machining method, or a convex-shaped blade corresponding to an R-shaped dimension formed at the bottom corner of the concave portion. Or an original plate for pad printing according to 3. A printed article obtained by performing pad printing using the pad printing original plate according to any one of claims 1 to 8 to form a rounded surface shape.

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