JP6311592B2 - Plastic molded product - Google Patents

Description

The present invention relates to a resin molded article having an uneven pattern on the surface.

  2. Description of the Related Art Conventionally, a resin molded product having a concavo-convex pattern formed by a plurality of ridges and valleys between ridges adjacent to each other has been used for interior parts such as automobiles. Such a resin molded product lacks a high-class feeling when the gloss value indicating the glossiness of the surface is high, and therefore, it is required to reduce the gloss value to lower the gloss value. For example, Patent Document 1 describes that the gloss is reduced by forming minute convex portions in the valley portions.

JP2013-139091A

  On the other hand, in addition to low gloss, resin molded products are also required to be improved in scratch resistance, which is difficult to scratch. A resin molded product having low scratch resistance is likely to be continuously linearly scratched when an interference object comes into contact with it. The portion where the line-shaped scratch is formed becomes conspicuous because the gloss value increases due to the flat surface.

This invention is made | formed in view of such a situation, The objective is to provide the resin molded product which enabled reduction in gloss and improvement in damage resistance.

A resin molded product that solves the above-mentioned problems is formed on a surface having a concavo-convex pattern constituted by a plurality of ridges and valleys between the ridges adjacent to each other, formed on the ridges, and separated from each other a plurality of first micro-protrusions are formed in the valley, the first minute projection sections smaller volume than, and e Bei a second minute projections of the plurality are separated from each other, the first The micro convex part has a root diameter of 250 μm or more and 300 μm or less, and a height of 20 μm or more and 40 μm or less, and the second micro convex part has a root diameter of 120 μm or more and 180 μm or less, and a height of It is 10 μm or more and 20 μm or less.

According to the above configuration, minute irregularities are formed on the surface of the peak portion by the first minute convex portion, and minute irregularities are formed on the surface of the valley portion by the second minute convex portion. Therefore, in addition to the concavo-convex pattern constituted by the ridges and valleys, the resin molded product has fine concavo-convexs finer than the concavo-convex pattern formed on the entire surface. As a result, since light incident on the resin molded product from any direction is dispersed and reflected, the resin molded product can be reduced in gloss. Moreover, even if the resin molded product and the interference object come into contact with each other because the frictional resistance on the surface of the resin molded product is increased by the first micro-projections, the stick in which the interference product adheres and slides on the resin molded product is repeated.・ Slip phenomenon tends to occur. As a result, the scratch resistance of the resin molded product is improved, and continuous linear scratches are hardly formed on the resin molded product.
By forming the first minute convex portion as described above in the peak portion, the peak portion can be reduced in gloss. Moreover, the scratch resistance of the resin molded product can be improved.
By forming the second minute convex portion as in the above configuration in the trough, the trough can be reduced in gloss.

In the resin molded product, it is preferable that the first minute convex portion is formed with 4 or more and 8 or less per 1 mm ² .
By setting the number of first minute convex portions per unit area as in the above configuration, the contact between the interference and the peak portion of the base portion can be suppressed while increasing the frictional resistance of the surface of the resin molded product.

  According to the above configuration, it is possible to reduce the gloss of the resin molded product and improve the scratch resistance.

It is a figure which shows the resin molded product of one Embodiment, Comprising: (a) is a top view which expands and shows the surface of a resin molded product, (b) is an end view which shows the end surface structure in a 1b-1b line | wire. . It is sectional drawing which shows typically an example of the cross-sectional shape of a micro convex part. It is sectional drawing which expands and shows a 1st minute convex part, Comprising: It is a figure which shows typically an example of a mode when the interference object is contacting the resin molded product. It is sectional drawing which expands and shows an example of the 1st minute convex part after an interference object contacts the resin molded product. It is a figure which shows the manufacturing process of a resin molding die, (a) is an end view which shows typically an example of a coating process, (b) is an end view which shows typically an example of a film removal process, It is a figure which expands and shows the process part by a laser beam, (c) is an end view which shows typically an example of a corrosion removal process, and is a figure which expands and shows one of the corrosion parts, (d) FIG. 3 is an end view schematically showing an example of a dissolution and removal process. It is an end view which shows typically an example of a 1st minute recessed part formation process, and is a figure which expands and shows the process part by a laser beam. It is an end elevation which shows typically an example of the 2nd minute crevice formation process, and is a figure expanding and showing a processing part by laser light.

One embodiment of a resin molded product and a resin mold will be described with reference to FIGS.
As shown in FIGS. 1A and 1B, the resin molded product 10 is manufactured by injection molding using a synthetic resin such as polypropylene. The resin molded product 10 is used for, for example, an automobile instrument panel, console, door trim, glove box, and the like.

  The resin molded product 10 includes a base portion 13 having a concavo-convex pattern constituted by a plurality of peak portions 11 and valley portions 12 between the adjacent peak portions 11. A plurality of first minute convex portions 15 having a dot shape are integrally formed on the mountain portion 11. The 1st minute convex part 15 is distributed in the state which mutually separated. A plurality of second minute convex portions 16 having a dot shape are integrally formed in the valley portion 12. The 2nd minute convex part 16 has a volume smaller than the 1st minute convex part 15, and is distributed in the mutually separated state. Thus, in the resin molded product 10, the grooving of the ridges 11 is reduced by forming the tiny irregularities formed by the first minute protrusions 15 on the ridges 11. In addition, since the fine irregularities formed by the second minute convex portions 16 are formed in the valley portions 12, the valley portions 12 are reduced in gloss.

  As shown in FIG. 2, the first minute convex portion 15 has a root diameter D <b> 1 that is a diameter at a boundary portion with the peak portion 11 and a height H <b> 1 that is a protruding length from the peak portion 11. Similarly, the second minute convex portion 16 has a root diameter D2 that is a diameter at a boundary portion with the valley portion 12, and a height H2 that is a protruding length from the valley portion 12.

  Here, if the volume is the same, the minute convex portion having a dot shape has a flatter shape as the ratio H / D of the height H to the root diameter D is smaller, and conversely, the ratio H / D is larger. The boundary part with respect to the base 13 is so small that it has a shape that protrudes high. Therefore, the smaller the ratio H / D of the first minute convex portion 15 is, the higher the gloss value of the peak portion 11 and the lower the frictional resistance of the surface of the resin molded product 10. Further, as the ratio H / D of the first minute convex portion 15 is larger, the mechanical strength of the first minute convex portion 15 itself becomes weaker, and when the interference object comes into contact with the resin molded product 10, The possibility that most parts are scraped off or the first minute protrusions 15 themselves are scraped off increases.

  Considering this, the first minute convex portion 15 is formed with a root diameter D1 of 250 μm to 300 μm and a height H1 of 20 μm to 40 μm. By setting the root diameter D1 to 250 μm or more, the mechanical strength at the boundary portion between the peak portion 11 and the first minute convex portion 15 is ensured, and when the interference object comes into contact, the first minute convex portion 15 itself is The possibility of scraping is reduced. By setting the root diameter D <b> 1 to 300 μm or less, it is possible to prevent the shape of the peak portion 11 from being restricted when the first minute convex portions 15 are formed on the peak portion 11 in a state of being separated from each other. Moreover, the frictional resistance of the surface of the resin molded product 10 can be reliably increased by setting the height H1 to 20 μm or more. By setting the height H1 to 40 μm or less, it is possible to suppress friction between the first minute convex portion 15 and the resin molding die when the resin molded product 10 is released from the resin molding die.

Further, as the number of the first minute convex portions 15 decreases, the frictional resistance of the surface of the resin molded product 10 decreases and the possibility that the interference object contacts the surface of the mountain portion 11 increases. Therefore, in order to suppress the contact between the interference and the surface of the peak portion 11 while increasing the frictional resistance of the surface of the resin molded product 10, the first minute convex portions 15 are formed with four or more per 1 mm ² . . On the other hand, as the number of first minute convex portions 15 increases, the root diameter D <b> 1 of the first minute convex portion 15 is more likely to be restricted based on the shape of the peak portion 11. Therefore, in order to increase the degree of freedom of the root diameter of the first minute protrusions 15, the first minute protrusions 15 are formed with 8 or less per 1 mm ² .

  On the other hand, since the first minute convex portion 15 reduces the grooving portion 11, the concavo-convex pattern constituted by the ridge portion 11 and the valley portion 12 is clarified in order to clarify the concavo-convex pattern. A higher contrast with 12 is preferred. That is, it is preferable that the valley portion 12 has a high shading feeling, and the second minute convex portion 16 is preferably not conspicuous. Further, the second minute convex portion 16 has the same number per unit area as that of the first minute convex portion 15 or higher than the first minute convex portion 15 in order to increase the contrast between the peak portion 11 and the valley portion 12. More is preferable.

  Considering this, the second minute convex portion 16 is formed with a root diameter D2 of 120 μm or more and 180 μm or less and a height H2 of 10 μm or more and 20 μm or less. By setting the root diameter D2 to 120 μm or more, the accuracy of the shape of the second minute convex portion 16 can be increased. By setting the root diameter D2 to be equal to or less than 180 μm, the second minute convex portion 16 becomes inconspicuous in the valley portion 12, and the shape of the valley portion 12 is restricted due to the shape of the second minute convex portion 16. It can be suppressed. Moreover, when the height H2 is set to 10 μm or more, the shape defect of the second minute convex portion 16 at the time of injection molding can be suppressed. By setting the height H <b> 2 to 20 μm or less, the second minute convex portion 16 does not stand out in the valley portion 12.

Next, the effect | action of the resin molded product 10 mentioned above is demonstrated.
In the resin molded product 10, minute irregularities are formed in the peak portion 11 by the first minute convex portion 15, and minute irregularities are formed in the valley portion 12 by the second minute convex portion 16. Therefore, in addition to the concavo-convex pattern constituted by the peaks 11 and the valleys 12, the resin molded product 10 has concavo-convex finer than the concavo-convex pattern formed on the entire surface. As a result, the overall gloss of the resin molded product 10 can be reduced. And since the volume of the 2nd minute convex part 16 is smaller than the volume of the 1st minute convex part 15, the further lower gloss of the trough part 12 whose gloss value is originally lower than the mountain part 11 is achieved. As a result, it is possible to increase the contrast of the concavo-convex pattern constituted by the peaks 11 and the valleys 12 while reducing the overall gloss of the resin molded product 10.

  Further, the first minute convex portion 15 is formed integrally with the peak portion 11, whereby the frictional resistance on the surface of the resin molded product 10 is increased. For this reason, even if an interference object comes into contact with the resin molded product 10, it is possible to cause a stick-slip phenomenon in which adhesion and slippage of the interference material to the resin molded product 10 are repeated. Thereby, the continuous linear damage | wound becomes difficult to be attached to the resin molded product 10. FIG.

  For example, as shown in FIG. 3, the interference 31 that has contacted the first position 15a of the first minute convex portion 15 bites into the first minute convex portion 15 at the first position 15a. And even if it tries to move in the direction of the arrow A while being in contact with the resin molded product 10, the interference 31 adheres to the resin molded product 10 in a state of biting into the first minute protrusion 15 at the first position 15 a. After that, it moves on the first minute convex portion 15 toward the second position 15b. The interfering object 31 bites into the first minute convex portion 15 at the second position 15b and again adheres to the resin molded product 10, and then moves on the first minute convex portion 15 toward the third position 15c. The interfering object 31 that has moved to the third position 15c bites into the first minute convex portion 15 and again adheres to the resin molded product 10, and then moves along the direction of the arrow A to differ. To touch.

  As shown in FIG. 4, in the resin molded product 10 after the interference object 31 comes into contact, the first position 15a, the second position 15b, and the third position of the first minute convex portion 15 due to the biting of the interference object 31. Damaged portions 32a, 32b, and 32c are formed at each of the positions 15c. These scratched portions 32a, 32b, and 32c are not continuous linear scratches along the direction of arrow A, but are local scratches lined up along the direction of arrow A. Thus, even if the interference product 31 comes into contact with the resin molded product 10, only local flaws are formed, so that continuous linear flaws are hardly damaged on the resin molded product 10.

  The resin molded product 10 described above is manufactured by injection molding using a plurality of resin molding dies. Each of the plurality of resin molding dies can be formed of steel, zinc alloy, aluminum alloy or the like. Among the plurality of resin molding dies, the resin molding dies having a resin molding surface for molding the above-described peak portion 11, trough portion 12, first minute convex portion 15, and second minute convex portion 16 are as follows. It is manufactured through the steps (a), (b), and (c) shown.

(A) A base molding part forming step of forming a base molding part for molding a base part 13 having a concavo-convex pattern composed of a peak part 11 and a valley part 12 in a resin molding die.
(B) A first minute concave portion forming step for forming a first minute concave portion for molding the first minute convex portion 15 by laser processing on a portion for molding the peak portion 11.

(C) A second minute concave portion forming step for forming a second minute concave portion for molding the second minute convex portion 16 by laser processing on a portion where the valley portion 12 is to be molded.
In the base molded part forming step, the base molded part is formed by etching the base material of the resin molding die. The base molding part forming process includes a coating process, a film removing process, a corrosion removing process, and a dissolution removing process.

  As shown in FIG. 5 (a), in the covering step, after dirt components such as oil and dust adhering to the resin molding surface 21 of the resin molding die 20 are removed by degreasing cleaning, A liquid for forming a corrosion-resistant film is sprayed on the entire surface. This liquid for forming a corrosion-resistant film is, for example, a liquid that has corrosion resistance against an etching corrosive liquid and is soluble in a cleaning liquid described later. And the resin molding surface 21 is coat | covered with the corrosion-resistant film | membrane 22 because this liquid hardens | cures.

  As shown in FIG. 5B, in the film removal step, the laser beam L1 is irradiated to the corrosion resistant film 22 using a laser processing machine. The laser beam L1 is applied to a portion where the peak portion 11 of the base portion 13 is to be formed. The anticorrosion film 22 at the portion irradiated with the laser beam L1 is removed by heating, melting or evaporating. Thereby, only the part which is going to shape the valley part 12 of the base part 13 is covered with the corrosion resistant film 22.

  As shown in FIG. 5 (c), the corrosion removal step is an etching step in which a portion of the resin molding surface 21 that is not covered with the corrosion-resistant coating 22 is removed by corrosion using a corrosive liquid 25. In the corrosion removing step, the resin molding die 20 is immersed in the corrosive liquid 25. As a result, a recess 26 is formed in the resin molding die 20 at a location where the peak portion 11 of the base portion 13 is to be molded. As the corrosive liquid, a chemical polishing liquid for iron and steel or an iron perchloride liquid alone or a mixture of water, nitric acid, hydrochloric acid or the like is used. The blending component and blending ratio of the corrosive liquid 25 are appropriately determined according to the material of the resin molding die 20 to be etched.

  As shown in FIG. 5D, in the dissolution removal step, the corrosion resistant film 22 remaining on the resin molding surface 21 is dissolved and removed by the cleaning liquid. Examples of the cleaning liquid include acetone, ketone, and a strong alkaline aqueous solution.

  In the base molding part forming step, the above-described coating step, film removal step, corrosion removal step, and dissolution removal step are repeated in this order. In the second and subsequent coating steps, the corrosion-resistant coating 22 is formed in the recesses 26 by applying a liquid for forming a corrosion-resistant coating, and in the second and subsequent corrosion removal steps, the portions of the recesses 26 are further removed by corrosion. . On the resin molding surface 21 of the resin molding die 20 after the base molding part forming step is completed, as shown in FIGS. 6 and 7, concave peak molding part 27 and valley part 12 for molding the peak part 11 are molded. A base molding part composed of the convex valley molding part 28 is formed.

  As shown in FIG. 6, the first minute recess forming process is performed after the base forming part forming process. In the first minute recess forming step, the peak forming portion 27 located in the portion irradiated with the laser beam L1 in the film removing step is irradiated with the laser beam L2 using a laser processing machine, thereby A first minute concave portion 29 for forming the one minute convex portion 15 is formed. The first minute recess 29 is formed by removing a portion irradiated with the laser beam L2.

  As shown in FIG. 7, the second minute recess forming step is performed next to the first minute recess forming step. In the second minute recess forming step, the laser beam L3 is irradiated to the trough forming portion 28 located in the portion where the laser beam L1 is not irradiated in the film removing step by using a laser processing machine. A second minute concave portion 30 for forming the second minute convex portion 16 is formed. The second minute recess 30 is formed by removing the portion irradiated with the laser beam L3.

  Note that the irradiation of the laser beams L1, L2, and L3 in the film removal step, the first minute recess formation step, and the second minute recess formation step is performed using a three-dimensional laser processing machine. The three-dimensional laser processing machine includes a table on which the resin molding die 20 is mounted and an irradiation device that irradiates the laser beams L1, L2, and L3. In the three-dimensional laser processing machine, the laser beam is emitted from the irradiation device while appropriately changing the irradiation direction of the laser beams L1, L2, and L3 through rotation of the table, rotation of the irradiation device, and change in the relative positions of the table and the irradiation device. The light L1, L2, and L3 are irradiated to partially remove the corrosion-resistant film 22 or partially remove the resin molding die 20.

  Thus, the resin molding die 20 is manufactured through the base molding portion forming step, the first minute convex portion forming step, and the second minute convex portion forming step. The resin molding die 20 is formed with a base molding part composed of a peak molding part 27 and a valley molding part 28, a first micro concave part 29, and a second micro concave part 30.

  When the resin molded product 10 is manufactured, a cavity for molding the resin molded product 10 is formed by combining the resin molding die 20 and another resin molding die, and the raw material resin is formed in the cavity. Material is filled. Then, after the filled resin material is solidified, each resin molding die is released, whereby the resin molded product 10 is manufactured.

The effect of the resin molded product 10 of the said embodiment is demonstrated.
(1) In the resin molded product 10, minute irregularities are formed in the peak portion 11 by the first minute convex portion 15, and minute irregularities are formed in the valley portion 12 by the second minute convex portion 16. For this reason, the overall gloss of the resin molded product 10 can be reduced. In addition, since the volume of the second minute convex portion 16 is smaller than that of the first minute convex portion 15, it is possible to reduce the overall gloss of the resin molded product 10 and to form a concavo-convex pattern composed of the peak portion 11 and the valley portion 12. The contrast can be increased.

(2) By forming the 1st minute convex part 15 in the peak part 11, it becomes difficult to attach a continuous linear damage | wound to the resin molded product 10. FIG.
(3) With the above (1) and (2), it is possible to reduce the gloss of the resin molded product 10 and improve the scratch resistance.

  (4) When the volume of the second minute convex portion 16 is larger than the volume of the first minute convex portion 15, the shape of the valley portion 12 is restricted by the second minute convex portion 16. There is a possibility that the degree of freedom of the concavo-convex pattern constituted by the troughs 12 is lowered. In this regard, in the resin molded product 10, since the volume of the second minute convex portion 16 is smaller than that of the first minute convex portion 15, the shape of the valley portion 12 is not limited by the second minute convex portion 16. As a result, a decrease in the degree of freedom with respect to the concavo-convex pattern constituted by the peaks 11 and the valleys 12 is also suppressed.

  (5) The first minute convex portion 15 has a root diameter D1 set to 250 μm or more and 300 μm or less, and a height H1 set to 20 μm or more and 40 μm or less. Thereby, even if the interference object 31 contacts the resin molded product 10, while reducing the grooving of the peak portion 11, most of the first minute convex portion 15 is scraped or the first minute convex portion 15 itself is scraped off. It can be suppressed. As a result, it is possible to efficiently reduce the gloss of the resin molded product 10 and improve the scratch resistance.

(6) the first micro-projection 15 is formed with four or more 8 or less per 1 mm ^2. Thereby, the freedom degree of the base diameter of the peak part 11 can be raised, suppressing that the interference object 31 contacts with the peak part 11 of the base part 13. FIG.

  (7) As for the 2nd minute convex part 16, root diameter D2 is set to 120 micrometers or more and 180 micrometers or less, and height H2 is set to 10 micrometers or more and 20 micrometers or less. Thereby, the 2nd minute convex part 16 can be made not conspicuous, improving the shading feeling of the trough part 12. FIG.

  (8) By molding the resin molded product 10 using the resin molding die 20, the resin molded product 10 having the first minute convex portion 15 and the second minute convex portion 16 is molded with high accuracy. Can do.

In addition, the said embodiment can also be suitably changed and implemented as follows.
-In the manufacturing process of a resin molding die, the sandblasting process by which a sand-like abrasive | polishing material is sprayed with compressed air after the 1st and 2nd minute recessed part formation process may be performed. According to such a configuration, the boundary portion can be made inconspicuous because the abrasive hits the boundary portion between the processed portion and the non-processed portion by the laser beams L2 and L3.

-In the manufacturing process of a resin molding die, the 2nd minute recessed part formation process may be performed before the 1st minute recessed part formation process.
The root diameter D2 and the height H2 of the second minute convex portion 16 can be appropriately changed according to the material of the resin molded product 10 and the shape of the valley portion 12. The root diameter D2 may be set to a value of less than 120 μm if the second minute convex portion 16 can be formed with high accuracy, and is less than 180 μm if the second minute convex portion 16 is inconspicuous. A large value may be set. Further, the height H2 may be set to a value less than 10 μm if the shape defect of the second minute convex portion 16 can be suppressed, or larger than 20 μm if the second minute convex portion 16 is not conspicuous. It may be set to a value.

-The peak part 11 should just be formed with the some 1st micro convex part 15. In FIG. Therefore, the number of first minute projections 15 per unit area, but various modifications can be made in accordance with the shape of the mountain portion 11 is not limited to four or more 8 or less per 1 mm ^2.

  The root diameter D1 and the height H1 of the first minute convex portion 15 can be appropriately changed according to the material of the resin molded product 10 and the shape of the peak portion 11. The root diameter D1 may be set to a value less than 250 μm if the mechanical strength at the boundary portion with the first minute convex portion 15 is ensured, or 300 μm if the shape of the peak portion 11 is not restricted. A larger value may be set. Further, the height H1 may be set to a value of less than 20 μm as long as sufficient frictional resistance is obtained, and the friction with the resin molding die may be suppressed when the resin molding die is released. For example, it may be set to a value larger than 40 μm.

  -The 1st minute convex part 15 should just be a minute convex part formed in the peak part 11, and the shape is not restricted to a dot shape, for example, the boundary part with the peak part 11 is a polygonal minute convex part. May be. In such a case, the root diameter is the diameter of the smallest circle among the circles that can surround the boundary portion of the polygonal shape.

  DESCRIPTION OF SYMBOLS 10 ... Resin molded product, 11 ... Mountain part, 12 ... Valley part, 13 ... Base part, 15 ... 1st minute convex part, 15a ... 1st position, 15b ... 2nd position, 15c ... 3rd position, 16 DESCRIPTION OF SYMBOLS 2nd minute convex part, 20 ... Resin molding die, 21 ... Resin molding surface, 22 ... Corrosion-resistant film, 25 ... Corrosion liquid, 26 ... Concave part, 27 ... Mountain part molding part, 28 ... Valley part molding part, 29 ... 1st minute recessed part, 30 ... 2nd minute recessed part, 31 ... Interfering object, 32a, 32b, 32c ... Damaged part.

Claims (3)

A base having a concavo-convex pattern formed on the surface by a plurality of peaks and valleys between the peaks adjacent to each other;
A plurality of first minute protrusions formed on the peak and separated from each other;
Wherein formed in the valleys, the first minute projection sections smaller volume than, and e Bei a plurality of second minute projections which are separated from each other,
The first minute convex portion has a root diameter of 250 μm or more and 300 μm or less, and a height of 20 μm or more and 40 μm or less,
The second minute convex portion is a resin molded product having a root diameter of 120 μm to 180 μm and a height of 10 μm to 20 μm . 2. The resin molded product according to claim 1, wherein the first minute convex portion is formed with 4 or more and 8 or less per 1 mm 2. 3. The resin molded product according to claim 1, wherein the number of the second minute convex portions is at least about the same as the number of the first minute convex portions .

Images