JP6334319B2 - Manufacturing method of metallic resin molded product - Google Patents

Description

This invention comprises the visibility of metallic, a method of manufacturing a superior main Tarik tone resin molded article appearance.

In recent years, in a resin molded product used for home appliances and the like, a color having a metallic feeling is adopted for the purpose of imparting a high-class appearance to the appearance design surface. Conventionally, a high-grade feeling has been imparted by painting a paint containing a metallic tone pigment on the surface of a molded product (see, for example, Patent Document 1).
However, in the method disclosed in Patent Document 1, although a metallic resin molded product can be obtained, it takes time and cost for the coating process, and peeling of the paint during use by consumers, use of organic solvents in the painting process, and air pollution There is a large environmental load such as scattering of substances.
On the other hand, high brightness obtained by injection molding a metallic resin that is pre-blended with a bright material such as aluminum flakes or pearl powder as an alternative to painting, for reasons such as reducing environmentally hazardous substances. Metallic-like molded products are being adopted.

Japanese Patent Laid-Open No. 2001-314813 (paragraph 0016, FIG. 1)

However, if the molded product that will be the exterior design surface is injection-molded with a metallic resin that is pre-blended with a bright material such as aluminum flakes or pearl powder, the metallic resin that is blended with the bright material is colored in a solid color with no metallic feeling. Compared to the above resin, molding failure such as a weld line is likely to occur due to the flow direction of the resin in the mold, and the color defect on the appearance design surface becomes remarkable.
In particular, convex ribs for reinforcement and fitting purposes provided on the back side of the appearance design surface of molded products have a wide range of resin flow directions during injection molding, and molding such as weld lines due to differences in flow speeds. It is easy to generate a defect. Due to the flow of the resin to the ribs and the occurrence of weld lines, the orientation of the glittering material in the resin becomes irregular and causes a color tone defect.
As described above, in the molded product of the metallic tone resin, there is a problem that the color tone defect occurs due to the irregular orientation of the glittering material in addition to the molding failure in the same manner as in the case of the solid color. In addition, there is a problem in that there are many design restrictions such as the need to select the shape of the molded product in advance in order to eliminate the occurrence of color tone defects.
The present invention has been made to solve the above problems, to provide a method of manufacturing a main Tarik tone resin molded article having a color defect suppressing structure of metallic tone resin molded article in an injection molding For the purpose.

Method for producing a metallic tone resin molded article of the invention this includes the step of injecting the appearance design unit having the appearance design surface of the resin containing the luminous material into a mold by injection molding, provided on the back surface of the exterior design part And a step of controlling the flow amount of the resin to the rib portion by a concave portion with the back surface of the appearance design portion provided at the base portion of the rib portion as an edge at the branch portion with the rib portion.

According to the present invention, the concave portion is provided at the base portion of the rib portion provided on the back surface of the appearance design portion, thereby adjusting the amount of resin that flows to the rib portion side at the time of injection molding. The orientation of the material can be made uniform in a certain direction, and the luster having an ideal metallic feeling with high brightness can be obtained by suppressing the color tone defect.
Further, by suppressing the generation of the weld line, it is possible to suppress the color tone defect caused by the weld line and to improve the design freedom in the shape of the molded product.

It is a perspective view which shows the structure of the metallic tone resin molded product by Embodiment 1 of this invention. It is an expanded sectional view which shows the structure of the metallic tone resin molded product by Embodiment 1 of this invention. It is a schematic cross section explaining the fountain flow in manufacture of the metallic tone resin molded product by Embodiment 1 of this invention. It is a schematic cross section which shows the orientation state of the glittering material after the fountain flow in manufacture of the metallic tone resin molded product by Embodiment 1 of this invention. It is an expanded sectional view which shows the orientation state of the luster material in manufacture of the conventional metallic tone resin molded product. It is an expanded sectional view explaining generation | occurrence | production of the weld line in manufacture of the conventional metallic tone resin molded product. It is an expanded sectional view which shows the orientation state of the luster material in the weld line in manufacture of the conventional metallic tone resin molded product. It is an expanded sectional view which shows the orientation state of the luster material in manufacture of the metallic tone resin molded product by Embodiment 1 of this invention. It is an expanded sectional view explaining the relationship between the orientation state of the luster material and reflection of a metallic tone resin molded product. It is a perspective view which shows the structure of the metallic tone resin molded product by Embodiment 2 of this invention. It is a perspective view which shows the other structure of the metallic tone resin molded product by Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 is a perspective view of a metallic tone resin molded product 100 according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along the line II of FIG.
A metallic-tone resin molded product 100 is obtained by molding a metallic-tone resin 5 containing a bright material such as aluminum flakes or pearl powder by an injection molding method. As shown in FIG. And a rib portion 2 provided on the back surface of the portion 1.

  The appearance design portion 1 has a thin plate shape having an appearance design surface 1a, and the thickness dimension is appropriately set in consideration of the fluidity and fillability of the metallic resin 5 and the component strength. The appearance design portion 1 is not limited to a plate shape, and the metallic design resin 5 that has passed through the gate can maintain a flow direction that does not form a defect such as a weld line. What is necessary is just to determine suitably a thickness dimension, a curved surface, a curved surface shape, etc.

  The rib part 2 consists of convex shape which has the latching | locking part 2a etc., and the back surface 1b of the external appearance design part 1 is provided with at least 1 or more for the purpose of fitting and reinforcement. In consideration of the strength of the entire rib portion 2, a recess 2 c is formed in the entire width of the rib portion 2 in the root portion 2 b of the rib portion 2. In FIG. 1, the recess 2 c is formed on the same side as the locking portion 2 a with respect to the thickness direction of the rib portion 2, but may be on the opposite side or on both sides.

Here, the thickness C (see FIG. 2) of the base 2b where the recess 2c of the rib 2 is formed depends on the physical properties such as the viscosity of the metallic resin 5 itself, but the thickness of the appearance design 1 With respect to A (see FIG. 2), the thickness difference (AC) with respect to the appearance design portion 1 is 0.1 in the range of 1/10 to 3/4 (1/10 ≦ C / A ≦ 3/4). It is preferable that the configuration is 5 mm or more (A−C ≧ 0.5 mm).
When the value of C / A exceeds 3/4 (C / A> 3/4), color unevenness or sink marks due to orientation failure of the glittering material are likely to occur on the appearance design surface 1a, and satisfy 1/10. When it is not present (C / A <1/10), it is difficult for the metallic resin 5 to flow through the root portion 2b of the rib portion 2. Even when the thickness difference (A−C) is less than 0.5 mm (A−C <0.5 mm), color unevenness due to poor alignment of the glittering material tends to occur on the appearance design surface 1a.

Further, the thickness dimension B (see FIG. 2) of the main body portion 2e of the rib portion 2 is equal to or smaller than the thickness dimension A (A ≧ B) of the appearance design portion 1, and is thicker than the thickness dimension C of the root portion 2b of the rib portion 2. (B> C) is set.
When the thickness dimension B of the main body part 2e of the rib part 2 is larger than the thickness dimension A of the appearance design part 1 (A <B), color irregularities and sink marks are caused on the appearance design surface 1a due to poor alignment of the glitter material. It becomes easy to do. When the thickness dimension B of the main body part 2e of the rib part 2 is equal to or less than the thickness dimension C of the base part 2b of the rib part 2 (B ≦ C), the metallic resin 5 is difficult to flow through the base part 2b of the rib part 2.

  Further, the thickness dimension A of the appearance design portion 1 is preferably 0.7 mm to 4.0 mm (0.7 mm ≦ A ≦ 4.0 mm), although it depends on physical properties such as the viscosity of the metallic resin 5 itself. . When the thickness dimension A is less than 0.7 mm (A <0.7 mm), the metallic resin 5 is difficult to flow through the appearance design portion 1. When the thickness dimension A exceeds 4.0 mm (A> 4.0 mm), irregularities such as sink marks are likely to occur on the appearance design surface 1a.

  The thickness B of the main body 2e of the rib 2 is 0.4 mm to 4.0 mm (0.4 mm ≦ B ≦ 4.0 mm), although it depends on physical properties such as the viscosity of the metallic resin 5 itself. It is preferable. When the thickness dimension B is less than 0.4 mm (B <0.4 mm), not only does the metallic resin 5 hardly flow through the base portion 2b and the main body portion 2e of the rib portion 2, but the reinforcing effect is insufficient. It is easy to become. When the thickness dimension A exceeds 4.0 mm (B> 4.0 mm), color unevenness and sink marks due to poor alignment of the glitter material occur on the appearance design surface 1a as in the case of A <B. Not only does this become easy, but irregularities tend to occur on the appearance design surface 1a.

The thickness C of the base 2b where the recess 2c of the rib 2 is formed depends on the physical properties such as the viscosity of the metallic resin 5 itself, but is 0.2 mm to 3.5 mm (0.2 mm ≦ C ≦ 3.5 mm) is preferable. When the thickness dimension C is less than 0.2 mm (C <0.2 mm), the metallic resin 5 is not only difficult to flow through the root portion 2b of the rib portion 2, but the reinforcing effect is likely to be insufficient. When the thickness dimension C exceeds 3.5 mm (C> 3.5 mm), color unevenness due to poor alignment of the bright material occurs on the appearance design surface 1a as in the case of the above-mentioned AC <0.5 mm. It becomes easy to do.
Further, the height dimension Ch of the root portion 2b in which the concave portion 2c of the rib portion 2 is formed depends on physical properties such as the viscosity of the metallic resin 5 itself, but is 0.1 mm to 3.0 mm (0.1 mm ≦ Ch ≦ 3.0 mm) is preferable. When the height dimension Ch is less than 0.1 mm (Ch <0.1 mm), the amount of resin flowing to the rib portion 2 side tends to be insufficiently controlled, and the appearance design surface 1a is caused by poor alignment of the glitter material. Color unevenness is likely to occur. When the height dimension Ch exceeds 3.0 mm (Ch> 3.0 mm), the metallic resin 5 becomes difficult to flow through the root portion 2 b of the rib portion 2.

  Moreover, although the height dimension Bh of the main-body part 2e of the rib part 2 is based also on physical properties, such as a viscosity, of the metallic resin 5 itself, it is preferable that it is 0.1 mm or more (Bh> = 0.1 mm). When the height dimension Bh is less than 0.1 mm (Bh <0.1 mm), it is difficult for the metallic resin 5 to flow through the root portion 2 b of the rib portion 2. The upper limit of the height dimension Bh is appropriately determined depending on the reinforcing effect of the molded product and the fluidity of the resin.

Next, the manufacturing method of the metallic tone resin molded product 100 by Embodiment 1 of this invention is demonstrated based on FIGS. First, resin flow in the injection molding method will be described.
In a general injection molding method, when the resin is melted in the cylinder of an injection molding machine and injected into the mold, the air gap in the mold is called a fountain flow. From the part, it flows so that it spouts one after another.

Similarly, in the production of the metallic-tone resin molded product 100 according to Embodiment 1 of the present invention, the metallic-tone resin 5 containing the flake-like or fibrous glittering material 4 such as aluminum flakes and pearl powder is obtained by injection molding. It flows with fountain flow.
FIG. 3 is a schematic diagram of the fountain flow of the metallic resin 5 containing the glitter material 4. The metallic tone resin 5 injected into the mold 6 flows near the center of the fluidized bed 5a in the D direction toward the leading end portion 5b in the flow direction, and the molten metallic tone resin 5 and the glittering material 4 are supplied.
Further, the metallic resin 5 that has reached the flow direction tip 5b flows in the direction of the mold 6 (directions E and F in FIG. 3) in the form of a fountain, and comes into contact with the inner wall surface of the mold 6 to melt the metallic tone. The resin 5 is cooled and solidified to form a metallic tone resin layer 5c in which the long sides of the flake-like or fibrous glittering material 4 are oriented in parallel along the flow direction of the metallic tone resin 5 (see FIG. 4).

Next, the flow of the metallic tone resin 5 in the rib portion 2 of the metallic tone resin molded product 100 when molded by the injection molding method will be described.
Usually, the resin injected into the mold flows through the gaps constituting the runner in the mold, and the gaps constituting the molded product are filled with resin from a filling port called a gate. If multiple gates are installed, the resin fillability in the gaps that make up the molded product will be improved, but the flow direction of the resin will also be diversified, which may cause molding defects such as weld lines. Also become.
Therefore, as much as possible, it is desirable to arrange the gates so that the appearance design is not impaired, and to reduce the number of gates. Here, it is assumed that the gate is installed at a position corresponding to the side surface 1c (see FIG. 1) of the exterior design portion 1.

FIG. 5 shows the orientation state of the glittering material 4 of the conventional metallic tone resin molded product 200 when molded from the gate position by the injection molding method. FIG. 5 is an enlarged cross-sectional view of the branch portion of the rib portion 20 in the appearance design portion 1, and the orientation of the glitter material 4 in the appearance design portion 1 is the region J of the branch portion of the rib portion 20 in the appearance design surface 1 a. You can see that it has changed.
In the conventional injection molding of the metallic tone resin molded product 200, the metallic tone resin 5 that has passed through the gate first flows in the D direction in the appearance design portion 1, but the flow direction in the branch portion of the rib portion 20 is in the G direction. And the flow direction (G direction) of the metallic resin 5 constituting the appearance design portion 1 and the flow direction (H direction) of the metallic resin 5 constituting the rib portion 20 are different from each other. The orientation of the glitter material 4 in the region J of the branch portion of the portion 20 is affected by the flow in each direction.
As a result, on the appearance design surface 1 a side of the appearance design portion 1, in the reflection with respect to the incident light to each particle of the glitter material 4, the appearance design portion 1 without the rib portion is regularly reflected, and the rib portion 20 There is a difference in color tone in the vicinity of the appearance design surface 1a of the branch portion of the rib portion 20 such that it is irregularly reflected in the region J of the branch portion or is not reflected (becomes dark) because the glitter material 4 is in the form of flakes or fibers. And a color tone defect of the metallic resin molded product 200 occurs.
Further, when the metallic tone resin 5 branches in two directions and the flow of the metallic tone resin 5 to the rib portion 20 increases, the outer appearance design portion 1 constituting the appearance design surface 1a after the branching becomes a metallic tone resin. When 5 passes through the branch portion, when viewed from the exterior design surface 1a side, the flow is partially delayed at the central portion where the rib portion 20 is arranged as shown in FIG. The flow of the resin in the two directions in the L direction merges to form a weld line.
FIG. 7 is a view seen from the side surface 1d (see FIG. 1) opposite to the side surface 1c of the exterior design portion 1 on which the gate is installed, and shows the orientation state of the glitter material 4 in the vicinity of the weld line 7. FIG. As shown in FIG. 7, in the vicinity of the weld line 7, the glittering material 4 is oriented along the merging plane.
On the appearance design surface 1a side, in the region M where the weld line 7 is present, the reflection of the particles of the luminous material 4 with respect to the incident light is scattered, and the reflection is irregularly reflected on the regularly reflecting portion without the weld line 7. The difference in color tone occurs due to the portion and the portion that does not reflect (becomes dark), and a color tone defect of the appearance design surface 1a of the metallic tone resin molded product 200 occurs.

On the other hand, in the metallic tone resin molded product 100 according to the first embodiment of the present invention, the concave portion 2c is formed in the root portion 2b of the rib portion 2 for the purpose of preventing the occurrence of color tone defects on the appearance design surface 1a. Is formed over the entire width of the rib portion 2.
In a general injection molding method, although depending on physical properties such as the viscosity of the resin itself, the thickness of the molded product is small, and there is a characteristic that it is difficult to flow into a thin part or a thin part in shape. In this invention, each direction after branching at the time of injection molding is provided by providing a concave portion 2c in the width direction of the rib portion 2 in the base portion 2b connecting the appearance design portion 1 and the rib portion 2 of the metallic tone resin molded product 100. It is possible to control the orientation of the glittering material 4 by adjusting the amount of resin that flows to the surface.
FIG. 8 shows the orientation state of the glitter material 4 of the metallic tone resin molded product 100 according to Embodiment 1 of the present invention. As shown in FIG. 8, in the injection molding of the metallic tone resin molded product 100, the metallic tone resin 5 flowing from the gate provided at the position of the side surface 1c (see FIG. 1) of the appearance design portion 1 is the appearance design portion. 1, the flow direction branches in two directions of the G direction and the H direction in the region J of the branch portion of the rib portion 2, but the rib portion is formed by the recess 2 c provided in the root portion 2 b. The amount of resin flowing to the second side is suppressed.

As shown in FIG. 9, the ideal glossiness with high brightness in the metallic resin molded product is obtained by regularly orienting the glitter material 4 blended in the metallic resin 5, from the incident light 9 of each particle of the glitter material 4. The reflection 10 becomes regular in a certain direction.
As a result of suppressing the amount of resin flowing toward the rib portion 2, the metallic resin 5 flows preferentially in the G direction of the appearance design portion 1 even when passing through the branch portion of the rib portion 2. Since the metallic tone resin 5 is flowing in the fountain flow, when cooled and solidified on the wall surface of the mold 6, as shown in FIG. 8, the surface layer of the appearance design surface 1 a of the molded product is the same as in FIG. 9. The glitter material 4 is solidified in an orientation that is parallel to the flow direction, and the back surface 1b side is solidified with the orientation of the glitter material 4 being different due to the flow in the H direction toward the rib portion 2.

The larger the difference in thickness between the outer appearance design portion 1 and the root portion 2b of the rib portion 2 thinned by the recess 2c, the more uniform the orientation of the bright material 4 on the surface layer of the outer appearance design surface 1a of the molded product is. . As a result, the reflection 10 from the incident light 9 of each particle of the glittering material 4 becomes regular in a certain direction, so that a gloss having a high brightness and an ideal metallic feeling with suppressed color tone defects can be obtained.
Further, the metallic tone resin molded product 100 is required to have strength as a component, and even when the difference between the thickness dimensions of the appearance design portion 1 and the base portion 2b of the rib portion 2 thinned by the concave portion 2c cannot be secured, Providing the recess 2c at the base 2b of the rib 2 also has an effect of concealing the color tone difference due to the orientation of the glitter material 4 in the vicinity of the rib 2 when viewed from the appearance design surface 1a side.
The metallic-tone resin molded product 100 according to Embodiment 1 of the present invention focuses on regularizing the orientation of the glitter material 4 in the metallic-tone resin 5 forming the surface layer on the appearance design surface 1a side in a certain direction. Even if it is a molded product having the rib portion 2 for the purpose of reinforcement or fitting, it has a configuration in which the orientation of the glitter material 4 on the exterior design surface 1a is uniformly formed, and is an epoch that suppresses color tone defects Means.

As described above, in the metallic tone resin molded product 100 according to the first embodiment of the present invention, the concave portion 2c is formed in the base portion 2b of the rib portion 2 provided on the back surface of the appearance design portion 1 in the width direction of the rib portion 2. By providing the whole, it is possible to adjust the amount of resin flowing to the rib part side at the time of injection molding, to uniform the orientation of the glitter material on the appearance design surface side in a certain direction, and to suppress color tone defects, A gloss having an ideal metallic feeling with high luminance can be obtained.
Further, by suppressing the generation of the weld line, it is possible to suppress the color tone defect caused by the weld line and to improve the design freedom in the shape of the molded product.
Further, by giving a metallic feeling to the molded product without requiring painting, it is possible to reduce the time and cost required for painting, and it is also possible to prevent paint peeling during use. In addition, the use of organic solvents in the painting process can be reduced, and environmental loads such as prevention of scattering of air pollutants can be reduced.

Embodiment 2. FIG.
In the first embodiment, the concave portion 2c is provided in the entire width direction of the rib portion 2 in the base portion 2b of the rib portion 2. However, in the second embodiment, the concave portion is partially formed in the width direction of the rib portion 2. The case where it is provided automatically will be described.

FIG. 10 is a perspective view of a metallic tone resin molded product 101 according to Embodiment 2 of the present invention. A sectional view taken along line II-II in FIG. 10 is the same as FIG.
In the root portion 2b of the rib portion 2, a concave portion 2d is formed in the center portion in the width direction, leaving both end portions in the width direction of the rib portion 2. That is, both end portions in the width direction of the rib portion 2 have the same thickness dimension B as the main body portion 2 e of the rib portion 2. In addition, in FIG. 10, although the recessed part 2d is formed in the same side as the latching | locking part 2a with respect to the thickness direction of the rib part 2, it may be an opposite side or both sides.

In this case, by forming the concave portion 2d in the center portion in the width direction of the rib portion 2, both end portions in the width direction have the same thickness dimension B as the main body portion 2e of the rib portion 2 at the base portion 2b of the rib portion 2. While having the same effect as Embodiment 1, the strength of the root portion 2b of the rib portion 2 can be improved.
About another structure, it is the same as that of the metallic tone resin molded product 100 of Embodiment 1 shown in FIG. 1, The same code | symbol is attached | subjected to the same part and the description is abbreviate | omitted.

As described above, in the metallic-tone resin molded product 101 according to the second embodiment of the present invention, both end portions in the width direction of the rib portion 2 are left on the root portion 2b of the rib portion 2 provided on the back surface of the appearance design portion 1. By providing the recess 2d in the center portion in the width direction, it is possible to adjust the amount of resin that flows to the rib portion side during injection molding, and to uniform the orientation of the glitter material on the appearance design surface side in a certain direction, By suppressing the color tone defects, it is possible not only to obtain a gloss having an ideal metallic feeling with high brightness, but also to improve the strength of the base part of the rib part.
In addition, by suppressing the occurrence of the weld line, it is possible to suppress color tone defects caused by the weld line and to improve the strength of the base part of the rib part. Can be improved.
Further, by giving a metallic feeling to the molded product without requiring painting, it is possible to reduce the time and cost required for painting, and it is also possible to prevent paint peeling during use. In addition, the use of organic solvents in the painting process can be reduced, and environmental loads such as prevention of scattering of air pollutants can be reduced.

In the second embodiment, the case where the concave portion 2d is provided in the central portion in the width direction of the root portion 2b of the rib portion 2 has been described, but the present invention is not limited to this. The same effect can be obtained if a part of the base part 2b of the rib part 2 has the same thickness as the main body part 2e of the rib part 2. For example, as shown to Fig.11 (a), the recessed part 2d may be formed in the width direction both ends of the base part 2b of the rib part 2, and the part of the same thickness as the main-body part 2e may be left in the center part.
Further, for example, as shown in FIG. 11B, two recesses 2d are formed in the central portion in the width direction of the base portion 2b, and portions having the same thickness as the main body portion 2e are left at the three end portions and the central portion. May be. In this case, the strength of the root portion of the rib portion can be further improved.

DESCRIPTION OF SYMBOLS 1 Appearance design part, 1a Appearance design surface, 1b Back surface, 2 Rib part, 2b Root part, 2c, 2d Concave part, 2e Main body part, 4 Bright material, 5 Metallic resin, 6 Mold, 100, 101 Metallic resin molding Goods

Claims (5)

A step of injecting a resin containing a glitter material into the mold from an appearance design portion having an appearance design surface by an injection molding method;
The flow amount of the resin to the rib portion by a concave portion with the back surface of the appearance design portion provided at the base portion of the rib portion at a branch portion with the rib portion provided on the back surface of the appearance design portion. A method of manufacturing a metallic-like resin molded product, comprising: The method for producing a metallic tone resin molded product according to claim 1 , wherein the concave portion is provided in the entire width direction of the rib portion. The method for manufacturing a metallic tone resin molded product according to claim 1 , wherein the concave portion is partially provided in a width direction of the rib portion. The method for producing a metallic resin molded article according to any one of claims 1 to 3 , wherein the glittering material is aluminum flakes or pearl powder. When the thickness of the appearance design part is A, the thickness of the rib part is B, the thickness of the base part of the rib part is C and the height is Ch, the following conditional expressions (1) to (7) 5) The method for producing a metallic resin molded product according to any one of claims 1 to 4 .
1/10 ≦ C / A ≦ 3/4 (1)
A-C ≧ 0.5 mm (2)
A ≧ B> C (3)
0.7 mm ≦ A ≦ 4.0 mm (4)
0.4 mm ≦ B ≦ 4.0 mm (5)
0.2 mm ≦ C ≦ 3.5 mm (6)
0.1 mm ≦ Ch ≦ 3.0 mm (7)

Images