JP5339736B2 - Manufacturing method of molding die and molding die - Google Patents

Description

  The present invention relates to a molding die used for imparting a concavo-convex pattern to the surface of a plastic molded product by injection molding or press molding, and a method for producing the same.

  The concavo-convex pattern on the surface of the plastic molded product is given by performing injection molding or press molding using a molding die having the concavo-convex pattern. The molding die having the concavo-convex pattern used here is mainly produced by an etching method. The etching method is a method of providing a three-dimensional shape on the surface of the molding die by forming an exposed surface and a non-exposed surface on the surface of the molding die and dissolving the metal on the exposed surface.

  Although such an etching method has the disadvantage that the carving is shallow and the three-dimensional effect is poor, the surface exposed to the processing liquid can be processed at the same time, and since a complicated curved surface and a large area can be processed, Commonly used.

  However, the etching process has a problem that it takes time to dissolve the metal and it is difficult to control the dissolution. Furthermore, once the metal is dissolved in etching, there is a problem that it cannot be restored and cannot be redone.

  In order to solve such a problem, means for forming a concavo-convex pattern by spraying or coating a synthetic resin on a mold has been proposed (Patent Document 1).

JP 2003-39441 A (Claims)

  According to Patent Document 1, the problem of the etching method can be solved. However, it is difficult to form a fine concavo-convex pattern by means of spraying or coating described in Patent Document 1, there is a limit to the thickness of the concavo-convex pattern, and it is difficult to form a wide variety of concavo-convex patterns. There was a problem.

The method for manufacturing a mold of the present invention for solving the above-mentioned problems, on the substrate, by printing using an inkjet printer to form a patterned layer using an ink containing a resin, further printing on the pattern layer Is repeated to form a concavo-convex pattern by laminating a plurality of pattern layers, and then sandblasting is performed from the concavo-convex pattern side.

The method for producing a mold according to the present invention is preferably characterized in that at least a part of the plurality of laminated pattern layers has a pattern area different from that of the other layers.

The method for producing a molding die according to the present invention is preferably such that the plurality of stacked pattern layers are first when the most base layer side is the first layer and the most surface side layer is the nth layer. The pattern area gradually increases from the layer toward the nth layer.

  The method for producing a molding die according to the present invention is preferably such that the plurality of stacked pattern layers are first when the most base layer side is the first layer and the most surface side layer is the nth layer. The pattern area gradually decreases from the layer toward the nth layer.

  The method for producing a molding die of the present invention is preferably characterized in that the printing is printing using an ink jet printer.

The molding die of the present invention is a molding die having a concavo-convex pattern on a substrate, wherein the concavo-convex pattern is formed by laminating a plurality of pattern layers made of a resin formed by printing using an inkjet printer. It is formed by sandblasting from the pattern side.

In the molding die according to the present invention, the plurality of laminated pattern layers may be arranged in such a manner that when the most base layer is the first layer and the most surface layer is the nth layer, the first layer to the nth layer. The pattern area gradually increases toward the layer .

In the molding die according to the present invention, the plurality of laminated pattern layers may be arranged in such a manner that when the most base layer is the first layer and the most surface layer is the nth layer, the first layer to the nth layer. The pattern area gradually decreases as it goes to the layer .

The interior molded product or the exterior molded product plastic molded product of the present invention is characterized in that a concavo-convex pattern is transferred using the molding die according to any one of claims 6 to 9. is there.

  The method for producing a mold for molding according to the present invention produces a concavo-convex pattern by laminating a plurality of pattern layers made of resin by printing. Therefore, the concavo-convex pattern can be applied to a fine pattern or a thick pattern. Can be produced. In addition, since the molding die of the present invention forms a concavo-convex pattern by laminating a plurality of pattern layers made of resin, it can cope with a fine pattern or a thick pattern.

  In the method for producing a molding die of the present invention, a pattern layer is formed by printing on a base material using an ink containing a resin, and printing is further repeated on the pattern layer to laminate a plurality of pattern layers. Thus, an uneven pattern is formed. Further, the molding die of the present invention is a molding die having a concavo-convex pattern on a substrate, wherein the concavo-convex pattern is formed by laminating a plurality of pattern layers made of a resin. . Hereinafter, a method for producing a molding die of the present invention and an embodiment of the molding die of the present invention will be described.

  First, a layer (pattern layer) having a predetermined pattern is formed on the substrate 1 by printing using an ink containing a resin. By this work, the first pattern layer (first layer) 21 made of resin is formed on the substrate 1 (FIGS. 1a and 2a).

  An ink containing a resin is used. As the resin contained in the ink, various thermoplastic resins, thermosetting resins, and ionizing radiation curable resins can be used. Among these resins, ionizing radiation curable resins are preferable in that they are excellent in quick-drying, can improve the durability of the uneven pattern, and can prevent penetration into the lower layer when forming the upper pattern layer.

  A general resin can be used. For example, the ionizing radiation curable resin is composed of a photopolymerizable prepolymer, a photopolymerizable monomer, and the like. Inks made of ionizing radiation curable resins, in addition to these photopolymerizable prepolymers and photopolymerizable monomers, contain a photopolymerization initiator, a diluting solvent, etc. as necessary, and are generally used. An ionizing radiation curable ink can be used.

  Further, it is preferable to select properties of the resin in the ink according to the purpose. For example, when it is desired to increase the shot resistance of the molding die, it is preferable to select a resin having sufficient durability against heat and pressure during molding. In the case of a molding die used for sample preparation, it is preferable to select an ink that is excellent in releasability from the substrate in order to facilitate reuse of the die.

  Pigments and dyes are not necessarily contained in the ink. In consideration of durability and the lamination process of each layer, the content of the pigment or dye is preferably such that the uneven pattern can be viewed.

  Examples of printing means include inkjet printing, silk screen printing, gravure printing, and offset printing. According to these printing means, it is possible to deal with a fine uneven pattern. Among these printing means, ink jet printing that is easy to print even on uneven substrates and that can easily reproduce fine patterns is preferable.

  When using a thermosetting resin or ionizing radiation curable resin, after forming the first pattern layer (first layer), before forming the second pattern layer (second layer), heat treatment or ionizing radiation is applied. The first layer is preferably cured by irradiation, and more preferably cured immediately after the formation of the first layer. By curing the first layer before forming the second layer, the resin of the second layer does not soak into the first layer when the second layer is formed, and the shape of the first layer is prevented from being deformed. And the thickness of the second layer can be made sufficient. Further, the pattern can be prevented from bleeding by curing the first layer immediately after the formation. In addition, when forming the third and subsequent layers, the same effect as described above can be obtained by preliminarily curing the previously formed layer. In order to sufficiently obtain such an effect, an ionizing radiation curable resin that is faster drying than a thermosetting resin and has a short crosslinking time is more preferable.

  A general method can be used for heat treatment of the thermosetting resin and irradiation of ionizing radiation to the ionizing radiation curable resin. For example, the irradiation with ionizing radiation is performed by irradiating ultraviolet rays in a wavelength region of 100 to 400 nm, preferably 200 to 400 nm from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp, or the like, or a scanning type or a curtain type. This can be performed by irradiating an electron beam in a wavelength region of 100 nm or less from the electron beam accelerator. When the printing means is ink jet printing, it is preferable that an ionizing radiation irradiation device is provided in the ink jet head so that it can be instantly cured after printing.

  The base material is a base material for the molding die, and has a strength that can withstand heat and pressure during molding. As the material of the base material, reinforced plastic or reinforced rubber can be used, but it is preferable to use a metal having excellent durability. Examples of the metal include not only steel materials such as prehardened steel, hardened steel, precipitation hardened steel, and stainless steel, but also non-ferrous metals such as zinc alloy, aluminum alloy, and beryllium copper alloy. The shape of the substrate is not limited to a flat shape, and may be a shape including a curved surface. In addition, if what has an uneven | corrugated pattern previously as a base material can be used, the uneven | corrugated pattern of a base material and the uneven | corrugated pattern formed by printing can be combined. Moreover, a concavo-convex pattern may be formed on a substrate that does not have sufficient durability alone, and the substrate may be bonded to a substrate having sufficient durability.

  The surface of the base material may be subjected to a roughening treatment or a corona discharge treatment in advance so as not to affect the molded product. By these treatments, the adhesion between the base material and the concavo-convex pattern can be improved. Examples of the roughening treatment include sandblasting and etching.

  After the first layer 21 made of resin is formed on the substrate 1 as described above, a pattern is printed on the first layer 21 with an ink containing resin, and the second layer 22 made of resin is laminated. (FIGS. 1b and 2b). Furthermore, if necessary, the third layer 23 may be formed on the second layer 22 (FIGS. 1c and 2c), and further may be formed as a fourth layer and a fifth layer.

  In the present invention, since the concavo-convex pattern 2 is formed by laminating a plurality of pattern layers made of resin in this way, a concavo-convex pattern having a thickness can be easily formed.

  The thickness of the concavo-convex pattern can be designed according to the purpose. However, according to the method of the present invention, the concavo-convex pattern can be formed even if the total thickness of the concavo-convex pattern exceeds 100 μm.

  The concavo-convex pattern does not necessarily have to be formed on the entire surface of the substrate, and may be formed only on a necessary portion.

  Further, at least a part of the plurality of pattern layers constituting the uneven pattern may have a pattern area different from that of the other layers. For example, when the most substrate layer is the first layer and the most surface layer is the nth layer, the pattern area is gradually increased from the first layer to the nth layer (FIG. 1). On the other hand, the area of the pattern is gradually reduced from the first layer to the nth layer (FIG. 2), or several layers of the same area are stacked, and the pattern area is reduced only at the end. (Figure 3). What is necessary is just to determine the change rate of the area for every layer suitably according to the objective. Thus, by making the area of the pattern of at least a part of the layers different from that of the other layers, it is possible to form a variety of uneven patterns.

  In addition, by gradually increasing the area of the pattern as it goes from the first layer to the nth layer, or conversely decreasing it, the texture of the concavo-convex pattern transferred to the plastic molded product can be smoothed. Further, it is possible to reduce the catch when the plastic molded product is pulled out from the molding die. This effect is more remarkable when the area of the pattern is gradually increased from the first layer to the nth layer.

  As described above, a concavo-convex pattern is formed by laminating layers made of a plurality of resins by printing. After forming the concavo-convex pattern by final printing, when printing is an inkjet method, it is preferable to perform a sandblasting process from the concavo-convex pattern side. By performing the sandblast treatment, the dots of the ink jet printing can be partially scraped, and the feel of the dots can be reduced from the concavo-convex pattern transferred to the plastic molded product, so that it can approach a natural feel. For sandblasting, the average particle size of silica sand, the injection amount, and the processing time may be selected in accordance with the size of the concavo-convex pattern and the desired feel.

  In addition, after forming the concavo-convex pattern by final printing, resin coating or plating may be performed on the concavo-convex pattern so that the thickness does not hinder the concavo-convex pattern. By applying resin coating or plating on the concavo-convex pattern, the shape of the concavo-convex pattern can be made smooth and the durability of the concavo-convex pattern can be improved.

  The molding die of the present invention produced as described above is used as a molding die at the time of injection molding or press molding, and the uneven pattern is transferred to the surface of the plastic molded product.

  Examples of the concavo-convex pattern include skin wrinkles and pear texture wrinkles. Skin wrinkles are wrinkle patterns found on the surface of leather, and are used in automobile interior moldings such as steering handles, console boxes, meter panels, dashboards, and side moldings. The pear texture refers to minute irregularities as seen on the surface of pear, and is used for exterior molded products of home appliances such as televisions, cooler panels, refrigerator panels, and washing machine panels.

  The following examples further illustrate the present invention.

[Example 1]
A pattern is printed on the surface of the mold subjected to a fine sandblasting process using an ink jet printer (UJF-605C II: Mimaki Engineering Co., Ltd.) using an ink containing an ultraviolet curable resin, cured by irradiating ultraviolet rays, One layer was formed (FIG. 1a). The pattern of the first layer was such that squares (one side 0.5 mm, thickness 15 μm) were arranged at a pitch of 2.5 mm in length and width. Next, a second layer was formed on the first layer pattern (FIG. 1b). The pattern of the second layer was a square (one side 0.7 mm, thickness 15 μm). Next, a third layer was formed so as to overlap the pattern of the second layer (FIG. 1c). The pattern of the third layer was a square (one side 1.0 mm, thickness 15 μm). Thus, the mold for Example 1 was obtained (FIG. 1c). The pitch of the second layer and the third layer is the same as that of the first layer.

[Example 2]
A pattern is printed on the surface of the mold subjected to a fine sandblasting process using an ink jet printer (UJF-605C II: Mimaki Engineering Co., Ltd.) using an ink containing an ultraviolet curable resin, cured by irradiating ultraviolet rays, One layer was formed (FIG. 2a). The pattern of the first layer was such that squares (one side: 1.0 mm, thickness: 30 μm) were arranged at a pitch of 2.5 mm in length and width. Next, a second layer was formed so as to overlap the pattern of the first layer (FIG. 2b). The pattern of the second layer was a square (one side 0.8 mm, thickness 30 μm). Next, a third layer was formed so as to overlap the pattern of the second layer (FIG. 2c). The pattern of the third layer was a square (one side 0.65 mm, thickness 30 μm). Next, a fourth layer was formed to overlap the pattern of the third layer (not shown). The pattern of the fourth layer was a square (one side 0.5 mm, thickness 30 μm). In this way, a molding die of Example 2 was obtained (not shown). The pitch of the second layer to the fourth layer is the same as that of the first layer.

  When injection molding was performed using the molding dies obtained in Examples 1 and 2, a plastic molded product having a concavo-convex pattern transferred to the surface was obtained. Further, the uneven pattern of the obtained plastic molded product was reproduced as a fine and thick uneven pattern, and the touch was smooth. In addition, the molds of Examples 1 and 2 had sufficient durability without peeling off the uneven pattern even when 100 shot molding was performed.

Process drawing which shows one Example of the manufacturing method of the shaping | molding die of this invention Process drawing which shows the other Example of the manufacturing method of the shaping | molding die of this invention Sectional drawing which shows one Example of the shaping | molding die of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ...... Base material 2 ... Uneven pattern 21 ... 1st layer 22 ... 2nd layer 23 ... 3rd layer 3 ... Mold for shaping | molding

Claims (9)

On the substrate, by printing using an inkjet printer to form a patterned layer using an ink containing a resin, by repeating the further printed on the pattern layer by stacking a plurality of pattern layers, an uneven pattern A method for producing a molding die, characterized in that after forming, sandblasting is performed from the concave-convex pattern side.   2. The method for producing a molding die according to claim 1, wherein at least a part of the plurality of stacked pattern layers has a pattern area different from that of the other layers.   The plurality of stacked pattern layers have a pattern area gradually increasing from the first layer to the nth layer, where the most base layer is the first layer and the most surface layer is the nth layer. The method for producing a molding die according to claim 2, wherein the molding die is large.   The plurality of stacked pattern layers have a pattern area gradually increasing from the first layer to the nth layer, where the most base layer is the first layer and the most surface layer is the nth layer. The method for producing a molding die according to claim 2, wherein the molding die is made smaller. In a molding die having a concavo-convex pattern on a substrate, the concavo-convex pattern is formed by laminating a plurality of pattern layers made of a resin formed by printing using an inkjet printer, and then sandblasting from the concavo-convex pattern side. A molding die characterized by comprising: 6. The mold according to claim 5, wherein at least a part of the plurality of stacked pattern layers has a pattern area different from that of the other layers. The plurality of stacked pattern layers have a pattern area gradually increasing from the first layer to the nth layer, where the most base layer is the first layer and the most surface layer is the nth layer. The molding die according to claim 6 , wherein the molding die is large. The plurality of stacked pattern layers have a pattern area gradually increasing from the first layer to the nth layer, where the most base layer is the first layer and the most surface layer is the nth layer. The molding die according to claim 6, which becomes smaller. An interior molded product or a plastic molded product for an exterior molded product, wherein the uneven pattern is transferred using the molding die according to any one of claims 5 to 8 .

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