JP2007301871A - Concave-convex side structure for printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concave-convex side structure for printing which enables an avoidance of an unclear display of printing caused by ink's spreading while enabling the printing display of character printed by an inkjet to be held stably without making the display disappear even if touching the printed surface with fingers after printing. <P>SOLUTION: The concave-convex side structure 10 for printing formed in the periphery of a cap 11 for applying an inkjet printing is composed of a concave-convex side 16 which comprises a projection 14 with many convex bars 13 and a recess 15 between each adjoining convex bars 13. The recess 15 has a flat or nearly flat bottom face part 15a with the width (b) of 50.0 to 500 μm, and the depth (c) measured between the bottom face part 15a and the top 14a of the projection 14 is 10.0 to 100 μm. Both sides 14b of the projection 14 are slopes with broadening toward the end towards the bottom face part 15a of the recess 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an uneven surface structure for printing, and more particularly to an uneven surface structure for printing provided on an outer peripheral surface of a resin molded product in order to perform ink jet printing.

  When printing on the outer peripheral surface of the resin molded product by, for example, inkjet, it is difficult to perform printing because the surface of the resin molded product is smooth, and the printed ink is on the surface It is easy to peel off because it is close to the ink, and it is often difficult to read the print by removing ink just by touching it with a finger or the like. For this reason, a resin molded product is molded using a mold in which irregular fine irregularities having a depth of about 30 to 100 μm are formed by, for example, sandblasting on a portion corresponding to the printing surface of the resin molded product, and transferred to the printing surface. A technique has been disclosed in which printing is easily performed by printing on a rough surface formed by irregular fine irregularities (for example, see Patent Document 1). By printing on the rough surface with fine unevenness, even if the print surface is touched with a finger after printing, the ink applied to the recess is not easily rubbed and the print is difficult to disappear. It can be stably held on the outer peripheral surface.

Also, molds with irregular fine irregularities formed by sandblasting etc. on the part corresponding to the printing surface of resin molded products are easy to collapse, and it takes time to maintain the mold and maintain irregularities. For example, the top surface of a polyolefin resin cap is used as the printing surface, and a large number of V-shaped grooves having a depth of about 30 to 100 μm are provided concentrically at a pitch of 300 to 700 μm by etching or the like. Also disclosed is a technique in which the print surface is roughened by providing a continuous surface (see, for example, Patent Document 2).
JP 2001-247684 A JP-A-2005-75441

  When printing on the printing surface of a resin molded product by inkjet, the oil-based or water-based ink used for inkjet printing contains an organic solvent or water as a solvent. A certain amount of time is required until the ink applied by volatilization is solidified. For this reason, on the rough surface by the V-shaped groove portion described in Patent Document 2, the applied ink flows along the narrow tip bottom portion of the acute groove portion before solidifying due to the action of surface tension or the like. The printed display may become blurred due to blurring of printed characters. Also, since the ink that has entered the bottom of the narrow tip of the V-shaped groove is difficult to dry, the printed display of printed characters and the like is more likely to spread.

  The present invention continues to stably display the printed display of characters and the like printed by inkjet on the outer peripheral surface of the resin molded article without disappearing because the printed surface after printing is not easily rubbed with a finger or the like (or An object of the present invention is to provide a concave / convex surface structure for printing which can effectively avoid blurring of the printed display due to ink bleeding during printing, while keeping the display content visible.

  The present invention relates to an uneven surface structure for printing formed on the outer peripheral surface of a resin molded product for performing ink jet printing, and includes a plurality of protrusions and protrusions between adjacent protrusions. The concave portion has a flat or substantially flat bottom portion having a width of 50.0 to 500 μm, and the depth of the bottom portion from the top of the convex portion is 10.0. The object is achieved by providing an uneven surface structure for printing of ˜100 μm.

  According to the concavo-convex surface structure for printing of the present invention, the printed display of characters and the like printed by ink jet is not rubbed with a finger or the like after printing and disappears on the outer peripheral surface of the resin molded product without disappearing. In addition to being able to continue displaying stably, it is possible to effectively avoid blurring of the printed display due to ink blurring during printing.

  As shown in FIG. 1, the uneven surface structure 10 for printing according to a preferred embodiment of the present invention is provided on the top surface of a cap 11 that is a resin molded product, for example, for displaying the expiration date. The printing surface 12 is formed. That is, the cap 11 is preferably used by being detachably mounted on a mouth and neck portion (not shown) of a soft synthetic resin container main body that contains a relatively high viscosity liquid food such as mayonnaise or kechip. Here, containers for storing foods such as mayonnaise and kechip are generally marketed in a state where they are stored in an outer bag that describes the expiration date, and consumers who have purchased the container should take out the container from the outer bag and use it. become. The uneven surface structure 10 of the present embodiment prevents the expiration date printed on the printing surface 12 from being lost due to friction with the outer bag or the like when the container is transported, and even after the outer bag is discarded. The expiration date formed on the cap 11 attached to the opening of the container for storing food and printed on the printing surface 12 is designated by a finger so that the expiration date of the food stored in the container over the period can be confirmed. Even if it is touched or rubbed, etc., it is employed so that it can be directly printed clearly without disappearing.

  The concave-convex surface structure 10 for printing in the present embodiment is a rough surface structure formed on the outer peripheral surface of the cap 11 that is a resin molded product in order to print characters, numbers, and the like by inkjet. As shown in FIGS. 2A, 2 </ b> B, and 3, the concave portion 15 includes a convex portion 14 formed by a large number of convex stripes 13 and a concave portion 15 between the adjacent convex stripes 13. Is provided with a flat or substantially flat bottom surface portion 15a having a width b of 50.0 to 500 μm, and a depth c from the top portion 14a of the convex portion 14 of the bottom surface portion 15a is 10.0 to 100 μm. Yes.

  In the present embodiment, the cap 11 is preferably an injection-molded product made of an olefin resin, and includes a disk-shaped top plate portion 11a and a skirt portion 11b that extends downward in a cylindrical shape from the peripheral portion of the top plate portion 11a. It consists of. On the inner peripheral surface of the skirt portion 11b, a female screw that is screwed into the mouth-neck portion of the container body is provided, and on the outer peripheral surface, irregularities for preventing slipping are provided. Further, the top surface of the cap 11 which is the outer peripheral surface of the top plate portion 11a is a flat flat surface, and this flat flat surface is used as the printing surface 12, and an uneven surface 16 composed of fine convex portions 14 and concave portions 15. Thus, the uneven surface structure 10 of the present embodiment is formed.

  In this embodiment, the concavo-convex surface 16 constituting the concavo-convex surface structure 10 is formed by using, for example, a die formed with a surface in which a large number of ridges 13 are regularly arranged in parallel at predetermined intervals by etching. It is formed by molding the printing surface 12 on the top surface of the cap 11. (Many ridges 13 are mechanically easier to form regularly, such as in parallel or at regular intervals, but it is not always necessary to form them regularly.)

  Here, the concave portion 15 of the concavo-convex surface 16 is formed such that the width b of the bottom surface portion 15a is 50.0 to 500 μm, and more preferably, the width b of the bottom surface portion 15a is 200 to 300 μm. . If the width b of the bottom surface portion 15a is smaller than 50.0 μm, it becomes difficult to dry the ink, so that there is a disadvantage that the possibility that the printing will spread out. If the width b of the bottom surface portion 15a exceeds 500 μm, the bottom surface 15a This causes a disadvantage that the possibility of being rubbed with a finger or the like becomes high when the outer bag, the packing material, or the container is used during distribution. In other words, by setting the width b of the bottom surface portion 15a to 50.0 to 500 [mu] m, the advantage that the printing is difficult to spread and hard to disappear can be obtained.

  Further, the concave portion 15 of the concavo-convex surface 16 is formed so that the depth c from the top portion 14a of the convex portion 14 of the bottom surface portion 15a is 10.0 to 100 μm, and the depth c from the top portion 14a is 30.0. It is preferably formed to be ˜70.0 μm. If the depth c from the top portion 14a of the bottom surface portion 15a is smaller than 10.0 μm, the height difference of the concave and convex surface 16 becomes small, so that there is a high possibility that the printing on the bottom surface portion 15a portion is also rubbed with a packing material or a finger. When the depth c from the top portion 14a of the bottom surface portion 15a exceeds 100 μm, it becomes difficult for the ink to reach the bottom surface portion 15a, so that the printing state may be deteriorated. In other words, by setting the depth c from the top portion 14a of the bottom surface portion 15a to 10.0 to 100 μm, an advantage that the printing state is good and hard to disappear can be obtained.

  It is preferable that the convex part 14 of the uneven surface 16 is formed so that the width a is 40 to 170 μm. Since the convex portion 14 has a width of 40 to 170 μm, the printing ratio to the convex portion 14 is reduced and the printing ratio to the concave portion 15 is increased. Printing on (especially the bottom surface portion 15a) remains, and an advantage of easily distinguishing the printed characters and numbers can be obtained.

  In the present embodiment, the convex portion 14 of the concavo-convex surface 16 is an inclined surface in which both side surface portions 14b widen toward the bottom surface portion. By making the both side surface portions 14b of the convex portion 14 into inclined surfaces, it is possible to increase the printing area, so that the ink is easy to dry and the characters do not bleed, and the boundary between the convex portion 14 and the concave portion 15 becomes inconspicuous. There is an advantage that the appearance of the top printing is improved. Moreover, it is preferable to incline the inclined surface so that the crossing angle θ between the side surface parts 14b of the convex part 14 and the bottom part 15a of the concave part 15 is 100 to 150 degrees, and more preferably the crossing angle θ is 120 to 140 degrees. The inclined surface is inclined so that By inclining the inclined surface so that the crossing angle θ is 100 to 150 degrees, the ink is easily dried and bleeding of characters can be suppressed, and the boundary between the convex portion 14 and the concave portion 15 or the convex portion 14 and the concave portion. The corner between 15 and 15 becomes inconspicuous, and the appearance of printing is improved in appearance. (If the inclined surface is standing, characters may be seen depending on the viewing angle. If the inclined surface is provided at a certain angle, the continuity of the printed characters will be improved. (It is possible to prevent the characters and the like from appearing to be stepped.)

  Furthermore, in this embodiment, it is preferable that the both side surface parts 14b of the convex part 14 used as the inclined surface and the bottom face part 15a of the recessed part 15 are connected via the curved surface 17 whose curvature radius r is 30-120 micrometers. Since the both side surface portions 14b of the convex portion 14 and the bottom surface portion 15a of the concave portion 15 are connected via the curved surface 17, the corner between the convex portion 14 and the concave portion 15 becomes smooth, and the ink printed by the ink jet can be obtained. Since it is difficult to accumulate at the corner between the convex portion 14 and the concave portion 15, it is easy to dry and the printing is difficult to spread.

  In the present embodiment, the top portion 14a of the convex portion 14 is a top portion that is curved in an arc shape, but may be a top portion that is cut flat or angular. Further, the bottom surface portion 15a of the recess 15 may be a curved surface or a surface including irregularities as long as it is a substantially flat surface in addition to a flat surface.

  In the present embodiment, ink-jet printing is performed on the top printing surface 12 of the cap 11 formed by the uneven surface structure 10 having the above-described configuration, and preferably the expiration date is printed. Here, the ink used for the ink jet is not particularly limited, but for example, an oil-based ink using an organic solvent such as methyl ethyl ketone (MEK) or a water-based ink using water considering the environment as a solvent can be used. . In addition, the ink used for inkjet is preferably 2 to 12 mPa · s, more preferably 2.5 to 10 mPa · s, at 20 ° C. in order to maintain good ejection properties. The average particle size of the water-insoluble vinyl polymer particles containing the colorant is preferably 0.01 to 0.5 μm, more preferably 0.03 to 0, from the viewpoint of preventing clogging of the printer nozzle and dispersion stability. .3 μm, particularly preferably 0.05 to 0.2 μm.

  And according to the uneven surface structure 10 for printing of this embodiment provided with the above-mentioned structure, a packing material contacts the printing surface 12 after printing the printing display (expiration date) of the character etc. which were printed by the inkjet. It is difficult to disappear even if it is touched with a finger or the like, and can continue to be displayed on the top surface of the cap 11, and it is possible to effectively avoid blurring of the printed display due to ink smearing during printing. it can.

  That is, according to the present embodiment, the concave / convex surface 16 for printing is constituted by the concave / convex surface 16 formed by the convex portions 14 by the numerous convex strips 13 and the concave portions 15 between the adjacent convex strips 13. 15 includes a flat or substantially flat bottom surface portion 15a having a width b of 50.0 to 500 μm, and a depth c from the top portion 14a of the convex portion 14 of the bottom surface portion 15a is 10.0 to 100 μm. Therefore, even if a finger or the like touches the printing surface 12, by touching only the top portion 14 a of the convex portion 14 with the finger or the like so as not to contact the concave portion 15, the both side surface portions 14 b and the concave portion 15 of the convex portion 14 are touched. It is possible to prevent the applied ink from peeling off, thereby effectively preventing the disappearance of the printed display (expiration date) printed on the printing surface 12. Further, since the concave portion 15 is provided with a flat or substantially flat bottom surface portion 15a, it is possible to prevent the applied ink from flowing to the surroundings due to the action of surface tension or the like. It is possible to effectively prevent the printed display from becoming obscured due to bleeding.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the uneven surface structure for printing according to the present invention is not necessarily formed on the top surface of the cap, and can be formed on other portions of the outer peripheral surface of the cap. Moreover, the resin molded product in which the uneven surface structure of the present invention is formed on the outer peripheral surface does not necessarily need to be a cap, and may be a container body or other various resin molded products. Furthermore, the large number of ridges arranged to form the concavo-convex surface do not necessarily have to be arranged in parallel in a stripe shape. For example, as shown in FIGS. It is also possible to form the concavo-convex surface 16 ′ by forming the ridges 13 ′ in a lattice shape and arranging the convex portions 14 ′ and the concave portions 15 ′ in a grid pattern. Furthermore, the number of ridges need not be limited to those extending in a straight line, and the intervals between adjacent ridges and the widths of the protrusions need not all be the same.

It is a perspective view which shows the cap which is a resin molded product provided with the uneven surface structure for printing which concerns on preferable one Embodiment of this invention. FIG. 1A is an enlarged plan view of a portion A in FIG. 1 for explaining the configuration of an uneven surface structure for printing according to a preferred embodiment of the present invention, and FIG. It is a B section enlarged plan view. It is a fragmentary sectional view explaining the structure of the uneven surface structure for printing which concerns on preferable one Embodiment of this invention. 1A is an enlarged plan view of a portion A in FIG. 1 for explaining the configuration of a concavo-convex surface structure for printing according to another preferred embodiment of the present invention, and FIG. FIG.

Explanation of symbols

10 Concave and convex surface structure for such printing 11 Cap (resin molded product)
11a Cap top surface portion 11b Cap skirt portion 12 Printing surface 13, 13 'Convex strips 14, 14' Convex portion 14a Convex top portion 14b Convex side portions 15, 15 'Concave portion 15a Concave bottom surface portions 16, 16' Concave and convex surface 17 Curved surface a between side and bottom surface a Width of convex part b Width of bottom part of concave part c Depth r from top part 14a of convex part of bottom part of concave part Curvature radius of curved surface

Claims (7)

An uneven surface structure for printing formed on the outer peripheral surface of a resin molded product in order to perform printing by inkjet,
Consists of a concavo-convex surface formed by a plurality of ridges and a recess between each adjacent ridge,
The concave portion has a flat or substantially flat bottom portion with a width of 50.0 to 500 μm, and the depth of the bottom portion from the top of the convex portion is 10.0 to 100 μm. Uneven surface structure.   The uneven surface structure for printing according to claim 1, wherein both side surface portions of the convex portion are inclined surfaces that are divergent toward the bottom surface portion of the concave portion.   The uneven surface structure for printing according to claim 2, wherein an angle of intersection between the inclined surface and the bottom surface portion is 100 to 150 degrees.   4. The uneven surface structure for printing according to claim 2, wherein the inclined surface and the bottom surface portion are connected via a curved surface having a radius of curvature of 30.0 to 120 [mu] m.   The printing for printing according to any one of claims 1 to 4, wherein the resin molded product is a cap made of an olefin resin, and the printing surface is formed on a flat surface provided on an outer peripheral surface of the cap. Uneven surface structure.   6. The uneven surface structure for printing according to claim 5, wherein the flat surface is a top surface of the cap. The concavo-convex surface structure for printing according to any one of claims 1 to 6, wherein the resin molded product constitutes at least a part of a container for containing food, and the ink-jet printing is a shelf life.

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