JP2013139091A - Resin molding, mold for molding resin and method for molding resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce a gloss value in a part where low gross is required.SOLUTION: This resin molding 11 includes a bulging part B formed at the surface thereof and a low-gloss part where a gloss value representing a value of a glossy level is lowered in a groove D between the bulging parts B so that a grained pattern (leather grain pattern) is applied thereto. In the low-gloss part, an arrangement pitch of a number of fine projections 12 is adjusted to 50-100% relative to a base diameter of the fine projection 12.

Description

  The present invention relates to a resin molded product, a resin molding die, and a resin molding method, and more particularly to a technique for improving molding quality in resin molding.

  2. Description of the Related Art Conventionally, a resin molded product used for interior parts in automobiles, for example, has been subjected to a processing technique such as a leather pattern in which a bulge portion and a groove portion between the bulge portions are formed on the surface as shown in FIG. Has been. In such a resin molded product, it is required to reduce the gloss value which is a value of gloss (gloss) (suppress gloss and to make it low gloss), and a technique for that is also known (for example, (See Patent Document 1 and Patent Document 2).

JP 2007-160637 A JP 2006-68972 A

  As described above, when a pattern such as a texture is given to a resin molded product, the surface may be processed using an etching technique in which a resin molding die is dissolved and eroded with a chemical or the like. That is, by molding a resin molded product with a resin molding die whose surface has been processed, light is scattered on the surface of the resin molded product to reduce the gloss.

  On the other hand, the resin molded product is also required to increase the contrast ratio between the bulging part and the groove part to produce a three-dimensional effect / shade feeling. For this reason, when the entire surface of the resin molded product is processed to reduce the gloss, the contrast ratio between the bulge and the groove cannot be increased sufficiently, and the three-dimensional effect / shade cannot be expressed. was there.

  Therefore, the present invention provides a resin molded product, a resin molding die, and a resin molding method capable of effectively reducing the gloss value in a portion where low gloss is required.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to the first aspect of the present invention, a low gloss portion in which a large number of minute convex portions are arranged is provided, and the arrangement pitch of the large number of minute convex portions is 50% or more and 100% or less with respect to the root diameter of the minute convex portions. It is what is.

  According to a second aspect of the present invention, in the low gloss portion, the minute convex portion is formed by a concave portion formed by etching in a resin molding die.

  According to a third aspect of the present invention, the low gloss portion is formed as a groove portion between the bulging portions in the embossed pattern in the resin molded product.

  In Claim 4, it has the low gloss part molding part by which many recessed parts were arranged, and the arrangement pitch of the many recessed parts is 50% or more and 100% or less with respect to the aperture of a recessed part, The low gloss part formation The part is formed by etching the concave part.

  According to a fifth aspect of the present invention, a resin molded product having a low gloss part is molded by the resin molding die according to the fourth aspect.

  According to a sixth aspect of the present invention, the low gloss portion is formed as a groove portion between the bulging portions in the embossed pattern in the resin molded product.

  As effects of the present invention, the following effects can be obtained.

  According to the present invention, it is possible to effectively reduce the gloss value in a portion where low gloss is required.

(A) is the figure which showed the surface of the resin molded product which concerns on this embodiment, (b) is the figure which showed the micro convex part in the low gloss part of a resin molded product, and the recessed part in the resin mold. (A) is the enlarged view which showed the surface of the resin molded product which concerns on 1st Example, (b) is the figure which showed the micro convex part in the low gloss part of a resin molded product, and the recessed part in the resin mold. (A) is the enlarged view which showed the surface of the resin molded product which concerns on a comparative example, (b) is the figure which showed the micro convex part in the low gloss part of the resin molded product, and the recessed part in the resin mold. (A) is the enlarged view which showed the surface of the resin molded product which concerns on 2nd Example, (b) is the figure which showed the micro convex part in the low gloss part of the resin molded product, and the recessed part in the resin mold. The figure which showed the surface of the resin molded product which concerns on a prior art.

Next, embodiments of the invention will be described.
It should be noted that the technical scope of the present invention is not limited to the following examples, but broadly covers the entire scope of the technical idea that the present invention truly intends, as will be apparent from the matters described in the present specification and drawings. It extends.

  As shown in FIG. 1A, the resin molded product 11 according to the present embodiment has a gloss value that is a gloss (gloss) value in a bulge portion B and a groove portion D between the bulge portions B on the surface. By forming the reduced low gloss portion, a texture pattern (skin texture pattern) is processed. However, the present invention is not applied only to a resin molded product provided with a texture pattern, but can be applied to all resin molded products having a low gloss portion.

  In the low gloss portion, a large number of minute convex portions 12, 12... Shown in FIG. 1B are arranged in a predetermined direction, and light is scattered by the minute convex portions 12, 12. The gloss value of the low gloss part is reduced (see FIG. 2A). The low gloss portion is formed by transferring the concave portion 112 formed in the resin molding die 111 shown in FIG. 1B to the surface of the resin molded product 11 to form the minute convex portion 12. Here, as shown in the shaded portion in FIG. 1B, the shaded portion S in the minute convex portion 12 is a tapered portion of the minute convex portion 12 (T in the cross section of the minute convex portion 12 in FIG. 1B). Part). That is, a portion corresponding to the t portion in the cross section of the concave portion 112 of the resin molding die 111 becomes a shaded portion S in the minute convex portion 12 and is expressed on the surface of the resin molded product 11.

  When the resin molding die 111 is manufactured, an etching technique is used in which a molding surface of a steel material that is a material of the resin molding die 111 is dissolved and eroded with a chemical or the like. Specifically, the concave portion 112 is formed by immersing the molding surface of the steel material with an etching solution obtained by adding an additive to nitric acid to corrode the surface of the steel material.

The resin molded product 11 according to the first embodiment will be described with reference to FIG. The resin molded product 11 according to the first embodiment has a low arrangement in which the arrangement pitch in the arrangement direction of a large number of microprojections 12 is 50% or more and 100% or less with respect to the root diameter of the microprojections 12. Has a gloss section. Specifically, as shown in FIGS. 2A and 2B, the root diameter of the minute projections 12 is 250 μm, the arrangement pitch of the minute projections 12 is 240 μm, and the height of the minute projections 12 is 60 μm. . That is, in this embodiment, as shown in FIGS. 2A and 2B, the adjacent minute convex portions 12 are partially overlapped with each other, and in this embodiment, each has a width of 10 μm.
In other words, the resin molding die 111 includes low-gloss portion forming portions arranged so that the arrangement pitch in the arrangement direction of the plurality of concave portions 112 is 50% or more and 100% or less with respect to the diameter of the concave portions 112. It has.

  On the other hand, in the resin molded product 31 according to the comparative example, as shown in FIGS. 3A and 3B, the root diameter of the microprojections 32 is 250 μm, the arrangement pitch of the microprojections 12 is 300 μm, and the microprojections The height of 32 is 60 μm. Similar to the minute projections 12 according to the first embodiment, the minute projections 32 are formed by transferring the recesses 132 formed in the resin molding die 131 onto the surface of the resin molded product 31.

  By configuring as described above, the interval between the adjacent minute convex portions 32 in the comparative example (the plane portion between the minute convex portions 32) does not exist between the adjacent minute convex portions 12 in the present embodiment. In the example, the area of the shaded portion S per unit area (area ratio of the shaded portion S) is relatively increased compared to the comparative example. That is, in the resin molded product 11 according to the present embodiment, light can be more scattered in the groove portion D in which the minute convex portions 12, 12... Are arranged as compared with the resin molded product 31 according to the comparative example. The gloss value of the low gloss portion can be reduced. Specifically, the gloss value of the low gloss portion in the comparative example was 0.8, whereas the gloss value of the low gloss portion in the present example could be set to 0.3.

From the viewpoint of efficiently ensuring the area of the shaded portion S per unit area, it is preferable to keep the width of overlapping the minute convex portions 12 to about several tens of μm.
Further, in order to reduce the gloss value of the groove portion D, which is a low gloss portion, it is necessary to ensure the relative area ratio of the shadow portion S as described above. For this purpose, the tapered portion in the cross section of the minute convex portion 12 is required. It is necessary to form T with a certain size. The shape of the tapered portion T in the minute convex portion 12 is defined by the shape of the t portion in the concave portion 112 of the resin molding die 111. When the concave portion 112 is formed by etching, the diameter and depth of the concave portion 112 affect the shape of the t portion. Therefore, in order to secure an effective area of the shadow portion S, the root diameter of the minute convex portion 12 (the concave portion It is preferable that the diameter is equal to or larger than a predetermined size. From such a viewpoint, it is preferable that the root diameter of the minute convex portion 12 is 240 μm or more.

  On the other hand, when the root diameter of the minute convex portion 12 is increased, the arrangement can be recognized with the naked eye. That is, since directionality appears in the arrangement of the minute projections 12 in the groove D, the root diameter of the minute projections 12 is preferably set to a predetermined size or less. From such a viewpoint, it is preferable that the root diameter of the minute convex portion 12 is 280 μm or less.

Thus, in the resin molded product 11 which concerns on a present Example, the gloss value of the groove part D which is a low gloss part was able to be reduced effectively.
Further, in the present embodiment, the low gloss portion is formed as a groove portion D between the bulging portions B in the embossed pattern in the resin molded product 11. For this reason, the contrast ratio between the bulging portion B and the groove portion D can be increased, and as shown in FIG. 1A, the three-dimensional effect / shade feeling in the embossed pattern can be expressed.

  In addition, in this embodiment, the microprojections 12 are arranged with the groove portion D as a low gloss portion, not the bulging portion B that is easily damaged. Thereby, low gloss can be realized without impairing scratch resistance on the entire surface of the resin molded product 11.

  Moreover, the low gloss part which concerns on a present Example is set as the structure by which the micro convex part 12 is formed of the recessed part 112 formed in the metal mold | die 111 for resin molding by the etching. Thereby, since the recess 112 in the resin molding die 111 can be formed with a simple configuration, the gloss value of the groove D can be reduced at a low cost.

  Next, the resin molded product 21 according to the second embodiment will be described with reference to FIG. Also in the resin molded product 21 according to the second embodiment, as in the resin molded product 11 according to the above-described embodiment, the arrangement pitch of a large number of minute protrusions 22 is 50% or more to the root diameter of the minute protrusions 100. % Of low-gloss portions arranged to be less than or equal to%. Specifically, as shown in FIGS. 4A and 4B, the root diameter of the minute projections 22 is 320 μm, the arrangement pitch of the minute projections 22 is 300 μm, and the height of the minute projections 22 is 80 μm. . That is, in this embodiment, as shown in FIGS. 4A and 4B, the adjacent minute convex portions 22 are partially overlapped with each other, and in this embodiment, each has a width of 20 μm.

  By configuring as described above, the interval between the adjacent minute convex portions 32 in the comparative example (the plane portion between the minute convex portions 32) does not exist between the adjacent minute convex portions 22 in the present embodiment. In the example, the area of the shaded portion S per unit area is relatively increased compared to the comparative example. That is, in this embodiment, compared with the comparative example, light can be more scattered in the groove portion D in which the minute convex portions 22, 22... Are arranged, so that the gloss value of the low gloss portion can be reduced. It can be done. Specifically, the gloss value of the low gloss portion in the comparative example was 0.8, whereas the gloss value of the low gloss portion in the present example could be set to 0.3.

Thus, also in the resin molded product 21 which concerns on a present Example, the gloss value of the groove part D which is a low gloss part was able to be reduced effectively.
Further, in the present embodiment, the low gloss portion is formed as a groove portion D between the bulging portions B in the embossed pattern in the resin molded product 21. For this reason, the contrast ratio between the bulging portion B and the groove portion D can be increased, and the three-dimensional effect / shade feeling in the embossed pattern can be expressed.

DESCRIPTION OF SYMBOLS 11 Resin molded product 12 Minute convex part 111 Mold for resin molding 112 Concave part B Bumping part D Groove part (low gloss part)
S shaded area

Claims (6)

It has a low gloss part in which a large number of minute convex parts are arranged,
The arrangement pitch of the large number of minute projections is 50% or more and 100% or less with respect to the root diameter of the minute projections.
A resin molded product characterized by that. In the low gloss portion, the minute convex portion is formed by a concave portion formed by etching in a resin molding die.
The resin molded product according to claim 1, wherein: The low gloss portion is formed as a groove portion between the bulging portions in the embossed pattern in the resin molded product.
The resin molded product according to claim 1 or 2, wherein It has a low-gloss part molding part in which a large number of recesses are arranged,
The arrangement pitch of the plurality of recesses is 50% or more and 100% or less with respect to the diameter of the recesses,
In the low gloss portion forming portion, the concave portion is formed by etching.
A mold for resin molding characterized by the above. The resin molding die according to claim 4, wherein a resin molded product having a low gloss portion is molded.
The resin molding method characterized by the above-mentioned. The low gloss part is formed as a groove part between the bulging parts in the embossed pattern in the resin molded product.
The resin molding method according to claim 5, wherein:

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