JP4515483B2 - Decorative resin molded product manufacturing method and decorative resin molded product - Google Patents

Description

  The present invention relates to a method for producing a decorative resin molded product, a decorative resin molded product, and an injection molding die for a decorative resin molded product, and in particular, a decoration that has been decorated to express a wood texture more realistically. The present invention relates to a method for producing a decorative resin molded article, such a decorative resin molded article, and an injection molding die for a decorative resin molded article that is advantageously used for molding the decorative resin molded article.

  Traditionally, decorative resin molded products that have been decorated to simulate the texture of wood have been widely used as surface materials for various products and articles such as automotive interior parts, furniture, building materials, and home appliances. ing. This is because by using this decorative resin molded product, the texture and luxury of wood can be obtained easily and at low cost.

  And in the manufacturing method of such a decorative resin molded product, for example, a resin film having a wood grain pattern printed on the surface is accommodated in a molding cavity of an injection mold, and then a molten resin that becomes a base material The so-called film-in-mold molding method (for example, see Patent Document 1 below) in which a material is injected, filled, and solidified, or a water-soluble film with a grain pattern printed on the surface thereof The wood grain pattern is transferred to the surface of the base material by bringing it into contact with the base material, or by floating the ink on the surface of the water flowing in the water tank and bringing the ink into contact with the base material. A so-called water pressure transfer method (see, for example, Patent Document 2 below) and the like are known. According to these conventional methods, there is an advantage that a wood grain pattern can be reliably and easily formed even on a design surface having a complicated shape.

  However, in the above-described film-in-mold molding method and the water pressure transfer method using a water-soluble film, a resin film on which a wood grain pattern is printed is formed prior to the step of molding the desired decorative resin molded product. In addition, even in the hydraulic transfer method that does not use a water-soluble film, first, a base material is formed, and then a grain pattern transfer process is performed on the design surface of the base material. The manufacturing work was carried out according to the procedure, and in any method, a wood grain pattern could not be formed on the design surface simultaneously with the molding of the decorative resin molded product.

  Therefore, in these conventional methods, the manufacturing process of the target decorative resin molded product is inevitably complicated, and this also hinders the reduction of the manufacturing cost. In addition, the decorative resin molded product obtained by the conventional method described above is simply a wood grain pattern formed on the design surface, so it is avoided that it lacks a sense of realism. I couldn't.

JP-A-9-109179 JP-A-9-277793

  Here, the present invention has been made in the background as described above, and the problem to be solved is simply a decorative resin molded product in which the wood texture is expressed more realistically. And a method that can be manufactured at low cost, a decorative resin molded product having a more realistic wood texture, and an injection molding die for a decorative resin molded product that is advantageously used in the manufacture of such a decorative resin molded product. It is to provide.

And in this invention, in order to solve the problem concerning the manufacturing method of the decorative resin molded product, the fine surface present on the surface of the wood is compared with the design surface having the same color as the wood. A method for producing a decorative resin molded product that is decorated to express a wood texture by forming a concave portion and a grain pattern similar to the groove-shaped concave portion, and (a) burning of the wood Using the thermosetting resin material or ceramic material that is melted or plasticized at a temperature lower than the temperature, the fine groove-like recesses are formed from the surface of the main wood by molding the fine groove-like recesses. A step of preparing a mold-molding body having a mold-molding surface on which protrusions corresponding to the groove-shaped recesses are formed, and (b) a design surface forming portion that forms the design surface At the design surface forming portion of the first cavity surface. Templating molded body, a first type comprising fixed in the surface opposite to the mold-up surface, wherein the back surface forming portion for forming a back surface opposite to the該意Takumi surface, said first cavity A second cavity surface that forms a molding cavity that gives the decorative resin molded product between the surface and the mold taking surface , and a back surface forming portion of the second cavity surface has a second cavity surface in the molding cavity. is injection, preparing a mold for injection molding and a second mold recessed portion or Ranaru more flow inhibiting unit that inhibits the flow of the molten resin material flowing in the molding cavity is provided And (c) using the prepared injection mold, a molten resin material having a color similar to that of the main wood is injected into the molding cavity of the injection mold, and the second cavity The plurality of flow hindrances provided in the back surface forming portion of the surface At By allowed to inhibit the flow of the molten resin material, so that the weld line is generated in the design surface, while flowing the molten resin material was filled into the molding cavity, the inside molding cavity By solidifying the molten resin material, the wood grain pattern is formed on the design surface by the weld line formed on the design surface, and the design surface forming portion of the first cavity surface Forming a concave portion corresponding to the fine protrusions on the mold-taking surface of the mold-molding body provided on the design surface having the same shape as the fine groove-shaped concave portion on the surface of the wood. A process for producing a decorated resin molded product, comprising a step of molding a resin molded product with a decoration that expresses the wood texture on the design surface having the same color as the wood. And its gist and Is shall.

In addition, according to one of the preferable aspects of the method for producing a decorated resin molded article according to the present invention, the plurality of flow inhibition portions are formed on the back surface forming portion of the second cavity surface of the second mold. It is composed of a boss forming recess and a rib forming recess provided, and these two recesses are arranged in a form in which the same size and different sizes are mixed, and preferably According to another aspect of the present invention, the flow inhibition portion including the rib forming recess is provided in a form extending in a direction intersecting the flow direction of the molten resin material in the molding cavity .

  Moreover, according to one of the desirable aspects of the manufacturing method of the decorative resin molded product according to the present invention, a flake-like glitter pigment is contained in the molten resin material.

  Furthermore, according to one of the advantageous aspects of the method for producing a decorated resin molded product according to the present invention, after molding the resin molded product that has been decorated to express the wood texture, the resin molded product in the resin molded product A step of forming a transparent coating film is further performed on the design surface on which the concave portion is formed. In addition, when the formation process of the transparent coating film with respect to such a design surface is implemented, advantageously, this transparent coating film will be formed using a transparent mat paint.

  According to another preferred embodiment of the method for producing a decorative resin molded product according to the present invention, the flow inhibition portion is constituted only by a recess formed in the back surface forming portion of the second cavity surface. Is done.

  Furthermore, according to another advantageous aspect of the method for producing a decorative resin molded product according to the present invention, the molten resin material flowing in the molding cavity is formed on the back surface forming portion of the second cavity surface. A concave groove extending in a direction crossing the flow direction is provided, and the flow inhibition portion is configured to include the concave groove. Further, the flow inhibiting part is advantageously constituted by such a concave groove and a concave part forming a columnar protrusion on the back surface opposite to the design surface.

  And, in the present invention, in order to solve the problems related to the decorative resin molded product to be formed, the concave portion and the wood grain pattern having the same shape as the fine groove-like concave portion existing on the surface of the present wood, A decorative resin molded product made of an injection-molded product, which is formed on a design surface having the same color as that of the present wood and decorated to express a wood texture, and is formed on the design surface A decorative resin molded product characterized in that a pattern is composed of at least one of a weld line and a flow mark formed on the design surface by an injection molding operation of the injection molded product. This is the gist.

  Further, according to one of the preferred embodiments of the decorative resin molded product according to the present invention, when the molten resin material having the same color as that of the main wood is injected and filled into the molding cavity that gives the injection molded product. Further, the melting is performed so that the flow of the molten resin material in the molding cavity is inhibited by a plurality of recesses provided in the back surface forming portion of the cavity surface that forms the back surface opposite to the design surface. The weld line is formed on the design surface by an injection molding operation for injecting and filling a resin material into the molding cavity, and the back surface forming portion of the cavity surface is formed on the back surface opposite to the design surface. And a plurality of protrusions corresponding to the plurality of recesses. The plurality of protrusions are advantageously composed of a plurality of rib-like protrusions and a plurality of columnar protrusions.

In addition, in the present invention, in order to solve the problem relating to the injection molding mold of the decorative resin molded product to be placed, the surface of the wood is against the design surface having the same color as the wood. An injection mold for injection-molding a decorative resin molded product with a decoration that expresses a wood texture by forming a recess and a grain pattern similar to the fine groove-like recesses present in And (a) using the thermosetting resin material or ceramic material that is melted or plasticized at a temperature lower than the combustion temperature of the main wood, the fine groove-shaped recesses are formed from the surface of the main wood. By molding, the fine groove-shaped recess is transferred, and a mold-molding body having a mold-forming surface on which protrusions corresponding to the groove-shaped recess are formed, and (b) forming the design surface A first cavity surface including a design surface forming portion, and the first cavity The design surface forming part of the surface, forming the mold cavity molding body, a first type comprising fixed in the surface opposite to the mold-up surface, a rear surface opposite to the (c) the design surface to include a rear surface forming portion, a second forming a mold cavity providing the decorated resin molded article with the templating surface of the first cavity surface and the mold cavity molding body that put on the first mold has a cavity surface, and the rear surface forming part of said second cavity surface, it is injected into the molding cavity, recess or Ranaru plurality of inhibiting the flow of the molten resin material flowing in the molding cavity A gist for injection molding of a decorative resin molded product characterized by including a second mold provided with a flow inhibiting part is also the gist thereof.

  That is, in such a method for producing a decorated resin molded product according to the present invention, when injection molding the target decorated resin molded product, a molten resin material having a similar color is used for the wood. Originally, weld lines and flow marks that occur as molding defects are intentionally generated on the design surface, and such weld lines and flow marks are used to create a design surface that has the same color as this wood (natural wood). A wood grain pattern is formed.

  Therefore, for example, unlike the conventional method for producing a decorative resin molded product using a film-in-mold molding method or a hydraulic transfer method using a water-soluble film, the process of molding the desired decorative resin molded product Prior to implementation, the need to form a resin film printed with a wood grain pattern can advantageously be eliminated. Also, unlike the conventional method of manufacturing a decorative resin molded product using a hydraulic transfer method that does not use a water-soluble film, after molding the base material of the decorative resin molded product, the grain pattern on the design surface of the base material The wood grain pattern can be formed on the design surface at the same time as the decorative resin molded product is formed, without going through two work steps such as performing the transfer step.

  In addition, in the method of the present invention, fine ridges corresponding to the fine groove-like recesses present on the surface of the wood are provided on the design surface forming portion that forms the design surface among the cavity surfaces of the molding cavity. By using the injection molding die, the target decorative resin molded product has a concave portion corresponding to the fine protrusions of the design surface forming portion on the design surface, that is, the fine surface existing on the surface of the wood. Injection molding is performed so as to provide a recess corresponding to the groove-shaped recess. As a result, a more realistic wood texture can be imparted to the design surface of the decorative resin molded product that has been injection-molded, as compared to a case where only a wood grain pattern is formed.

  Therefore, according to such a method for producing a decorative resin molded product according to the present invention, a decorative resin molded product having a more realistic wood texture, which can hardly be obtained by the conventional production method, with a small number of steps, It can be manufactured easily and at a lower cost.

  In addition, the flow of the molten resin material in the molding cavity using an injection mold in which a plurality of flow-inhibiting portions are provided in the back surface forming portion that forms the back surface of the design surface among the cavity surfaces of the molding cavity. According to the method for producing a decorative resin molded product of the present invention in which a weld line is generated on the design surface by inhibiting a plurality of flow inhibiting portions, a general injection condition is not adopted, In the injection molding operation under typical injection conditions, the weld line can be generated more reliably and advantageously on the design surface, and thus the above-mentioned excellent characteristics can be more effectively exhibited. It becomes.

  And in the decorative resin molded product according to the present invention, the wood pattern is formed on the design surface by the weld line and the flow mark generated on the design surface by a predetermined injection molding operation, and this wood Since the concave portion having the same shape as the fine groove-like concave portion present on the surface of the wood is provided on the design surface, the wood texture can be expressed more realistically, and the texture and luxury of the wood can be further enhanced. In addition, such a realistic wood texture can be provided simply and at low cost.

  Further, in the mold for injection molding of a decorative resin molded product according to the present invention, a fine protrusion corresponding to a fine groove-like recess on the surface of the present wood is formed on the design surface forming portion of the first cavity surface. On the other hand, the back surface forming portion of the second cavity surface is provided with a plurality of flow inhibiting portions that inhibit the flow of the molten resin material in the molding cavity, so that the target decorative resin molded product By being used at the time of molding, substantially the same functions and effects as those exhibited in the method for producing a characteristic decorative resin molded product can be enjoyed extremely effectively.

  Hereinafter, in order to clarify the present invention more specifically, an embodiment of the present invention will be described in detail with reference to the drawings.

  First, in FIGS. 1 to 4, as an example of a decorative resin molded product manufactured according to the method of the present invention, a cover panel (lid body) of a storage box, which is a kind of automobile interior parts, has a perspective form on its upper surface. They are respectively shown in a perspective view, a longitudinal sectional view, and a partially enlarged view of the lower surface. As is clear from these figures, the cover panel 10 as a whole has a substantially rectangular housing shape having a predetermined thickness, and is a thermoplastic resin generally used as a material for forming interior parts for automobiles. It is comprised by the injection molded product injection-molded using resin materials (for example, ABS resin etc.).

  Further, in the cover panel 10, the entire outer surface exposed to the outside is the design surface 12, and a large number of wood grain patterns 14 and wood grain textures 16 are formed on the design surface 12. Has been. Further, the cover panel 10 has the same brown or dark brown color as that of the present wood, and further contains, for example, a flake-like glitter pigment such as a metallic pigment or a pearl pigment. It is formed using a resin material. As a result, the entire surface including the design surface 12 is colored brown, dark brown, or the like similar to the present wood, and light is reflected by the glitter pigment, so that a high-class feeling can be obtained. ing.

  Here, the many wood grain patterns 14 are constituted by weld lines 18 that are formed on the design surface 12 in the course of the injection molding operation of the cover panel 10. In addition, a large number of wood grain textures 16 are formed of fine groove-like recesses extending with various lengths. And in such wood grain grain 16, the cross-sectional shape is various shapes such as a triangle shape, a U-shape, a trapezoidal shape, or an indefinite shape, and the opening shape is also different. The grain-like textures 16 have different and relatively complicated shapes. Further, the depth of the grain-like grain 16 is also different in depth between different ones. Furthermore, although not shown in the figure, even in the single grain tone 16, there are a shallow portion and a deep portion.

  Thus, in the cover panel 10 according to the present embodiment, in addition to the design surface 12 being provided with a large number of wood grain patterns 14 formed of weld lines 18 generated during molding, the present wood (natural wood) Similar to the fine groove-like recesses present on the surface of the veneer plate, the grain-like texture 16 made of groove-like recesses having various lengths and depths and various complex opening shapes and cross-sectional shapes is provided as a design. Many are formed on the surface 12. As a result, the design surface 12 of the cover panel 10 is decorated so that the wood texture can be expressed more realistically.

  Further, in the cover panel 10, the clear coating film 20 is laminated on the entire design surface 12. The clear coating film 20 is formed so as to cover the entire surface of the design surface 12 by applying a known transparent paint by a method similar to the conventional one. As a result, the design surface 12 of the cover panel 10 is effectively given a high-class feeling like a mirror finish, and further, the weather resistance and impact resistance of the design surface 12 of the cover panel 10 are enhanced. The design surface 12 is difficult to be wrinkled. In addition, here, the thickness of the clear coating film 20 is sufficiently thin, and the surface of such a clear coating film 20 is also fine on the surface corresponding to a large number of wood grain textures 16 and a large number of wood grain patterns 14, respectively. A groove-like recess is formed, so that a touch close to that of the present wood can be obtained.

  Furthermore, in the cover panel 10 of the present embodiment, a plurality of bosses 22 and ribs 23 as protrusions are provided on the back surface 21 which is the surface opposite to the design surface 12 in the thickness direction, respectively. It is provided integrally. Each of the plurality of bosses 22 has a cylindrical shape with a low height as a whole. Further, in the plurality of bosses 22, those having the same height and diameter and those having at least one of the height and diameter are mixed.

  On the other hand, each of the plurality of ribs 23 has a rectangular flat plate shape extending in the width direction of the back surface 21 of the cover panel 10 as a whole, and has a predetermined thickness, a relatively low height, and a width of the back surface 21 of the cover panel 10. It has a sufficiently short length. Further, among the plurality of ribs 23, the same thickness, height, and length are mutually mixed, and at least one of the thickness, height, and length is different from each other. Yes.

  The plurality of bosses 22 and the plurality of ribs 23 are positioned on the back surface 21 of the cover panel 10 with appropriate intervals in the length direction and the width direction. That is, the plurality of bosses 22 and the plurality of ribs 23 are positioned so as to be randomly scattered on the back surface 21 of the cover panel 10.

  By the way, when manufacturing the cover panel 10 having such a structure, for example, first, an injection mold having a molding cavity corresponding to the outer shape of the target cover panel 10 is formed and prepared. Then, the cover panel 10 is injection molded in the molding cavity of the prepared injection molding die.

  More specifically, when forming an injection mold having a molding cavity corresponding to the outer shape of the cover panel 10, first, as shown in FIG. 5, various depths and various complex opening shapes and cross-sectional shapes are used. A veneer plate 25 made of the present wood having a large number of fine groove-like recesses 24 on the surface thereof is prepared, and a number of fine groove-like recesses are formed from the surface using the prepared veneer plate 25. 24 is molded on a mold-taking surface 28 of a mold-molding body 26 made of a predetermined resin material, and a large number of ridges 30 corresponding to a large number of groove-like recesses 24 are formed on the mold-taking surface 28. .

  In addition, although the specific operation which should be implemented is not specifically limited, for example, this mold making process proceeds according to the following procedure. That is, first, in the molding cavity of a molding die composed of an upper mold and a lower mold, the veneer 25 has a surface opposite to the surface on which many fine groove-shaped recesses 24 exist on the lower mold cavity surface. It is accommodated and placed in a state where it is in contact with. Next, in the molding cavity in which the veneer 25 is accommodated, a surface in which a predetermined resin material that provides the mold-molding molded body 26 is in a molten or plasticized state and a large number of fine groove-like recesses 24 of the veneer 25 are present. Filled so that it touches the top. Then, if necessary, the resin material in the molding cavity is solidified or cured in a state where the resin material is pressed by the upper mold, so that a plate-shaped resin molded body is formed. Thereafter, after the plate-shaped resin molded body and the veneer plate 25 are released from the molding die, the veneer plate 25 is peeled off from the plate-shaped resin molded body. In this step, a release agent layer is formed by applying, for example, a known release agent to the cavity surface on which the veneer plate 25 is placed in contact. This facilitates peeling of the veneer 25 from the resin molded body molded in the molding cavity.

  Thus, in this step, the molded resin body 26 having a plate-like shape as a whole is formed from the plate-shaped resin molded body molded as described above, and at the same time, the veneer in the molding cavity. A large number of fine groove-like recesses 24 on the surface of the veneer 25 are transferred to the mold taking surface 28 which is a contact surface with 25, and a large number of fine protrusions 30 respectively corresponding to the many groove-like recesses 24 are provided. It is formed.

  In addition, as the resin material for forming the mold-molding body 26 in this step, a thermosetting resin material that is melted or plasticized at a temperature lower than the combustion temperature of the veneer 25 is preferably used. Because, when using such a thermosetting resin material, it is avoided that the veneer 25 burns when such resin material comes into contact with the veneer 25 in a molten or plasticized state, thereby This is because a large number of minute groove-like recesses 24 on the surface of the veneer 25 can be reliably and accurately transferred to the mold-taking surface 28 of the mold-taking molded body 26. Further, when the target cover panel 10 is manufactured in an injection molding process as will be described later, a predetermined molten resin material is put into the molding cavity of the injection mold in which the mold-molding molded body 26 is fixed to the cavity surface. When injection molding and filling are performed, it is avoided that the mold-molding body 26 is heated by contact with the molten resin material to be melted or plasticized again, and thus the design of the target cover panel 10 is achieved. This is because the ridges 30 of the mold surface 28 in the mold body 26 can be reliably and accurately transferred to the surface 12.

  When the mold-molding body 26 is molded, an injection-molding mold 32 having a structure as shown in FIG. 6 is produced (formed) using this mold-molding body 26 and prepared.

  Note that the injection mold 32 prepared and prepared in this step includes, for example, an upper mold 34 as a first mold and a lower mold as a second mold, which are arranged so as to be relatively close to each other in the vertical direction. It has a split mold structure with a mold 36. The upper mold 34 of the injection molding die 32 has a rectangular cavity forming recess 38 that opens downward, and the lower mold 36 is more than the cavity forming recess 38 of the upper mold 34. It integrally has a rectangular cavity forming convex portion 40 that protrudes upward with a small size. Then, in the state where the upper mold 34 and the lower mold 36 are matched to each other (mold closing), the cavity forming convex portion 40 of the lower mold 36 is fitted into the cavity forming concave portion 38 of the upper mold 34, By covering the opening of the cavity forming recess 38 with the lower mold 36, the inner surface of the cavity forming recess 38 and the outer surface of the cavity forming protrusion 40 are respectively placed between the upper mold 34 and the lower mold 36. A rectangular molding cavity 42 having one cavity surface and a second cavity surface is formed (see FIG. 7).

  In addition, the cavity forming convex portion 40 is fitted into the cavity forming concave portion 38 by fitting the upper mold 34 and the lower die 36, and the cavity forming convex portion 40 is opposed to the bottom surface of the cavity forming concave portion 38. A plurality of boss forming recesses 44 and rib forming recesses 46 are formed. Each of the plurality of boss forming recesses 44 and the plurality of rib forming recesses 46 has an inner surface shape corresponding to each of the plurality of bosses 22 and the plurality of ribs 23 formed on the back surface 21 of the cover panel 10. Yes.

  That is, here, the front end surface of the cavity forming convex portion 40 in the lower mold 36 is a back surface forming portion 48 that provides the back surface 21 of the target cover panel 10. The forming recesses 44 and the plurality of rib forming recesses 46 are spaced apart from each other at appropriate intervals in the length direction and the width direction of the back surface forming portion 48, in other words, are randomly scattered or scattered. In this case, the upper opening is provided. Further, the plurality of boss forming recesses 44 and the plurality of rib forming recesses 46 have the same size, depth, shape and the like between the boss forming recesses 44 and between the rib forming recesses 46. Those that are the same and those that are different from each other are mixed together. Further, in the plurality of rib forming recesses 46, when the molten resin material is injected and filled into the molding cavity 42 as will be described later, it intersects the flow direction of the molten resin material in the molding cavity 42. It is formed so as to extend in a direction perpendicular to the direction.

  In this step, the mold-carrying molded body 26 is bonded to the entire bottom surface of the cavity forming recess 38 in the upper mold 34 on the surface opposite to the mold-carrying surface 28 using an adhesive. As a result, the injection mold 32 for injection molding the target cover panel 10 is produced. In addition, the bottom surface of the cavity forming recess 38 in the upper mold 34 of the injection mold 32 thus manufactured is used as the design surface forming portion 50 that gives the design surface 12 of the target cover panel 10. A large number of protrusions 30 corresponding to a large number of fine groove-like recesses 24 on the surface of the thrust plate 25 are formed on the entire surface forming portion 50.

  Next, the injection mold 32 thus produced is used, and as shown in FIG. 7, the upper mold 34 and the lower mold 36 of the injection mold 32 are matched with each other. A molding cavity 42 is formed therebetween.

  Subsequently, as shown in FIG. 8, a predetermined molten resin material is injected and filled from a nozzle of an injection molding machine (not shown) into a molding cavity 42 formed between the upper mold 34 and the lower mold 36. Thereafter, the molten resin material filled in the molding cavity 42 is allowed to cool and solidified. As a result, the design surface 12 is formed on the contact surface of the cavity forming recess 38 of the upper die 34 with the design surface forming portion 50, and many of the design surfaces 12 are provided on the design surface forming portion 50. A resin molded product 52 in which a large number of wood grain textures 16 corresponding to the large number of ridges 30 are formed is molded in the molding cavity 42.

  In this step, the molten resin material injected into the molding cavity 42 contains a pigment such as brown or dark brown, and is colored in the same color as the wood, and in addition to that, a flaky metallic What contains the bright pigments, such as a pigment and a pearl pigment, is used. Thereby, the whole including the design surface 12 of the resin molded product 52 is colored brown or dark brown similar to the main wood. In addition, the presence of the metallic pigment or the pearl pigment exhibits a glitter property that reflects light particularly on the design surface 12, and a high-class feeling can be obtained.

  In addition, the large number of grain-like textures 16 formed on the design surface 12 of the resin molded product 52 are formed in a shape corresponding to the protrusions 30, so that the fine particles existing on the surface of the veneer 25 Similar to the groove-shaped recess 24, the cross-sectional shape is various shapes such as a triangular shape, a U-shape, a trapezoidal shape, or an indefinite shape, and the opening shape is also different between the grain-like textures 16 of different wood grain. The shapes are different from each other and are relatively complicated. Further, the depth of the grain-like grain 16 is also different in depth between different ones. Furthermore, although not shown in the figure, even in the single grain tone 16, there are a shallow portion and a deep portion.

  In this step, when the molten resin material is injected from the nozzle of the injection molding machine into the molding cavity 42 and filled, a part of the molten resin material passes through the molding cavity 42 and the cavity forming convex portion of the lower mold 36. The plurality of boss forming recesses 44 and the plurality of rib forming recesses 46 provided in the back surface forming portion 48 of the 40 are allowed to flow while entering the plurality of rib forming recesses 46. At that time, the smooth flow of the molten resin material in the molding cavity 42 is obstructed, and a flow in which some of the molten resin materials collide with each other is generated, whereby the cavity forming recess 38 of the upper die 34 is formed. Many weld lines 18 (very fine concave grooves or steps) are formed on the contact surface with the design surface forming portion 50.

  In addition, as described above, the plurality of boss formation recesses 44 and the plurality of rib formation recesses 46 include a mixture of a size, a depth, a shape, and the like that are the same as each other and a configuration in which they are different from each other. I'm hurt. Therefore, in each of the plurality of weld lines 18 formed by inhibiting the flow of the molten resin material in the molding cavity 42 by each of the plurality of recesses 44 and 46 having such a non-uniform shape, Different irregular curves and straight lines are drawn on the design surface 12 of the molded product 52. Thus, the grain pattern 14 that artificially represents the annual rings of the present wood is formed on the design surface 12 of the resin molded product 52 by an irregular curve composed of the large number of weld lines 18. . As is apparent from this, in the present embodiment, the boss formation recess 44 and the rib formation recess 46 constitute a flow inhibition portion.

  In the present embodiment, the plurality of rib forming recesses 46 extend in a direction perpendicular to the flow direction of the molten resin material in the molding cavity 42. The flow resistance of the molten resin material is greater than that of the plurality of boss formation recesses 44. For this reason, the wood grain pattern 14 formed of the weld line 18 that is generated when the flow of the molten resin material is obstructed in the rib forming recess 46, and the weld line that is generated when the flow of the molten resin material is inhibited in the boss forming recess 44. It is formed so as to draw a larger curve than the wood grain pattern 14 composed of 18 and to draw a clear curve or straight line.

  Here, since the molten resin material that gives the resin molded product 52 contains a bright pigment such as a flaky metallic pigment or a pearl pigment, the molten resin materials flowing in the molding cavity 42 collide with each other. Then, the flake-like glittering pigment is raised at the portion where the molten resin materials collide with each other, and it becomes difficult to reflect light. As a result, the weld line 18 formed in the portion where the molten resin materials collide with each other, and the wood grain pattern 14 formed of the weld line 18 become black stripes on the design surface 12. It will be formed so that it can be clearly and clearly visible.

  Thus, the wood texture 14 formed of the weld lines 18 and the many grain-like textures 16 having the same shape as the large number of fine groove-like recesses 24 existing on the surface of the veneer 25 are formed on the design surface 12. The resin molded product 52 that has been decorated to express the above is injection molded in the injection mold 32 (molding cavity 42). Thereafter, as shown in FIG. 9, the resin molded product 52 is released from the injection mold 32. Subsequently, although not shown, after removing burrs and the like, a transparent paint such as urethane paint is applied to the entire surface of the resin molded product 52, and the clear coating film 20 is applied. Is formed. Thus, the target cover panel 10 having the structure shown in FIGS. 1 to 4 is obtained. Also in this step, prior to the injection of the molten resin material into the molding cavity 42 of the injection molding die 32, the inner surface of the cavity forming recess 38 of the upper die 34 and the cavity of the lower die 36 in the injection molding die 32. A release agent layer is formed, for example, by applying a known release agent to the outer surface of the forming convex portion 40. Thereby, the releasability of the resin molded product 52 from the injection mold 32 is enhanced.

  As described above, in the present embodiment, the cover panel 10 is molded at the same time as the target cover panel 10 is molded simply by performing a single injection molding operation of injecting, filling, and solidifying the molten resin material into the molding cavity 42. A large number of wood grain patterns 14 and a large number of wood grain textures 16 can be formed on the design surface 12 of the cover panel 10. Therefore, unlike the conventional method, for example, prior to the molding operation of the cover panel 10, an operation of molding a resin film or the like on which the wood grain pattern 14 is printed, or an operation of molding a base material that does not have the wood grain pattern 14 The need to do etc. can be advantageously eliminated. Moreover, the grain-like texture 16 formed on the design surface 12 of the cover panel 10 together with the grain pattern 14 may be different from each other or similar to the groove-like recess 24 on the surface of the veneer 25. It has various depths and various complicated opening shapes and cross-sectional shapes.

  Therefore, according to the present embodiment as described above, the cover panel 10 having both a more realistic wood texture and a wood texture, and a high-class feeling, which cannot be obtained in the past, can be achieved with a small number of steps. It can be manufactured easily and at a lower cost. The cover panel 10 thus obtained can be widely applied to uses and the like that have been difficult to use in the past due to lack of luxury, for example.

  Further, in the present embodiment, the injection using the injection mold 32 in which a plurality of boss forming recesses 44 and rib forming recesses 46 are provided in the back surface forming part 48 of the cavity forming convex part 40 of the lower mold 36. By performing the molding operation, the flow of the molten resin material in the molding cavity 42 is inhibited at the respective recesses 44 and 46, and the grain of the weld line 18 is formed on the design surface 12 of the molded resin product 52 to be molded. A large number of patterns 14 are formed. Therefore, for example, by performing the injection operation under the general injection conditions without performing any troublesome operations such as changing the injection conditions such as the temperature and injection pressure of the molten resin material or the injection mold 32. In general, the weld line 18, which is normally poorly formed, can be intentionally and easily generated on the design surface 12. As a result, the wood grain pattern 14 can be easily formed on the design surface 12.

  Furthermore, in the present embodiment, the plurality of boss forming recesses 44 and the plurality of rib forming recesses 46 that are the flow resistance of the molten resin material in the molding cavity 42 are the same in size, depth, shape, and the like. And those different from each other are mixed together, so that the wood grain pattern 14 composed of the weld lines 18 made of irregular and more complicated curves and straight lines has a design surface. 12 is formed. Therefore, such a wood grain pattern 14 has a more natural texture rather than an orderly artificial texture, and thus gives the cover panel 10 a more realistic and natural wood texture. It can be harassed.

  Furthermore, in the present embodiment, when the cover panel 10 is molded, the ridge 30 that forms the wood grain texture 16 on the surface thereof uses the veneer plate 25 to form the fine groove-shaped recess 24 existing on the surface. Since it has the transferred shape, the cover panel 10 has a real feeling as if it was formed using the actual veneer 25, that is, the texture of the bark of the present wood. Even subtle gloss changes can be advantageously applied.

  In the present embodiment, a plurality of boss forming recesses 44 and a plurality of rib forming recesses 46 are provided in the back surface forming portion 48 of the cavity forming convex portion 40 of the lower mold 36, and the cover panel 10 Projections such as bosses 22 and ribs 23 corresponding to the respective recesses 44 and 46 are formed on the rear surface 21, and such boss formation recesses 44 and rib formation recesses 46 are formed in the molding cavity 42. Therefore, a large number of weld lines 18 are formed on the design surface 12 of the cover panel 10. For this reason, for example, the back surface forming portion 48 of the cavity forming convex portion 40 of the lower mold 36 is different from the case of providing a large number of convex portions serving as flow resistance (inhibiting flow) of the molten resin material in the molding cavity 42. Thus, although a large number of weld lines 18 are formed on the design surface 12 of the cover panel 10, a large number of concave portions corresponding to the large number of convex portions are provided on the back surface 21. It is possible to prevent the strength from being lowered.

  The specific configuration of the present invention has been described in detail above. However, this is merely an example, and the present invention is not limited by the above description.

  For example, in the above embodiment, the back surface forming portion 48 of the cavity forming convex portion 40 of the lower mold 36 is provided with a plurality of boss forming recesses 44 and rib forming recesses 46 as flow inhibiting portions. Although the mold 32 is used, an injection molding mold 32 in which only one of the boss forming recess 44 and the rib forming recess 46 is provided may be used. This also makes it possible to form a large number of wood grain patterns 14 including weld lines 18 on the design surface 12 of the cover panel 10 finally obtained.

In addition, the flow inhibition portion is not limited to the illustrated boss formation recess 44 and rib formation recess 46, and the flow of the molten resin material injected into the molding cavity 42 is inhibited. as may be, provided on the rear surface forming portion 48, a recess made of concave grooves or recesses having various shapes and depths, etc., it may be properly adopted.

Further, the arrangement position and arrangement設個number on the back formation of the fluidized inhibition portion consisting of concave portions also, the grain pattern to be formed on the design surface of the decorated resin molded article of interest (cover panel 10) Needless to say, the shape, size, number, and the like can be changed as appropriate.

  Furthermore, there is no problem even if the clear coating film 20 formed on the design surface 12 of the cover panel 10 as a decorative resin molded product is omitted. Even when the clear coating film 20 is formed, the clear coating film 20 can be formed using a known transparent matte paint such as a urethane paint. Thereby, the tactile sensation of the design surface 12 of the cover panel 10 can be expressed not as a hard feeling of resin but as a soft feeling of wood.

  In the above embodiment, the veneer 25 is used as the material to be transferred of the fine groove-shaped recess 24. However, various kinds of wood other than the veneer 25 can be used as the material to be transferred. is there.

  Further, a method for forming the protrusion 30 corresponding to the groove-like recess 24 existing on the surface of the wood such as the veneer 25 on the design surface forming portion 50 of the cavity forming recess 38 of the upper die 34 in the injection mold 32. Are not particularly limited to those illustrated.

  For example, instead of a thermosetting resin material, a ceramic material is used, and the wood such as the veneer plate 25 is accommodated in a molding cavity of a predetermined mold, and then the ceramic material is filled, By carrying out a die press molding method or the like, a die-molding body made of ceramics, on which the protrusions 30 corresponding to the groove-like recesses 24 existing on the surface of the wood such as the veneer 25 are transferred, is formed. . And the method etc. which adhere this molding body to the design surface formation part 50 of the cavity formation recessed part 38 of the upper mold | type 34 in the surface on the opposite side to the formation surface of the protrusion 30 can also be employ | adopted.

  Also, for example, first, after transferring the groove-like concave portion 24 of the main wood such as the veneer 25 to the first mold-taking surface of the first mold-made molded body made of resin, and forming the first protrusion, The first protrusion of the first mold-molded product is transferred to the second mold-carrying surface of the ceramic second mold-molded product, and a corresponding groove is formed. The concave groove of the second mold-molded product is transferred to the third mold-carrying surface of the mold-molded product, and the second corresponding to the groove and the groove-shaped concave portion 24 of the present wood such as the veneer 25. The ridge (ridge 30) is formed. A method for fixing the third die-molded molded body to the design surface forming portion 50 of the cavity forming recess 38 of the upper die 34 on the surface opposite to the surface on which the second protrusion is formed is also appropriately determined. Can be employed. In addition, the shaping | molding method of a 1st thru | or 3rd die-molding molded object and the transfer method of each protrusion and a ditch | groove are not limited at all.

  Thus, the groove-shaped recess 24 existing on the surface of the main wood such as the veneer 25 is secured by fixing the ceramic molding to the design surface forming portion 50 of the cavity forming recess 38 of the upper die 34. In the case of forming the ridge 30 (second ridge) corresponding to the ridge, for example, at the time of molding the target decorative resin molded product (cover panel 10), the ridge is caused by the flow pressure of the resin material. It is advantageously avoided that 30 is deformed, and as a result, the shape of the grain-like grain 16 can be made to exactly match the shape of the groove-like recess 24 on the surface of the veneer 25.

  Further, a method for forming the protrusion 30 corresponding to the groove-like recess 24 existing on the surface of the wood such as the veneer 25 on the design surface forming portion 50 of the cavity forming recess 38 of the upper die 34 in the injection mold 32. In addition, there is a method of forming a desired protrusion 30 by performing a known etching process or the like on the design surface forming portion 50.

  In addition, in the above-described embodiment, the present invention has been shown as a specific example of a storage box cover panel which is a kind of automobile interior parts, a manufacturing method thereof, and a molding die used therefor. For other interior parts for automobiles, parts or components other than automobile interior parts, and methods for producing decorated resin molded products, and molds for decorated resin molded products and decorative resin molded products Of course, it can be advantageously applied.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is an isometric view explanatory drawing which shows the cover panel as one Embodiment of the decorative resin molded product manufactured according to this invention method. It is a perspective explanatory view showing the back surface form of the cover panel shown in FIG. It is the elements on larger scale in the III-III cross section of FIG. It is the elements on larger scale in FIG. When manufacturing the cover panel shown in FIG. 1 according to the present invention, it is an explanatory view showing an example of a process when forming an injection mold, and molds a groove-like recess on the surface of the veneer, The state which formed the die-molding molded object is shown. FIG. 6 is an explanatory diagram illustrating an example of a process performed subsequent to FIG. 5, and is an injection molding for molding a target cover panel by fixing a mold-molding molded body to a design surface forming portion of a cavity surface of an upper mold. The state which formed the type | mold was shown. FIG. 7 is an explanatory view showing an example of a process for manufacturing the cover panel shown in FIG. 1 using the injection mold shown in FIG. 6 according to the method of the present invention, and closing the injection mold. And the state which formed the molding cavity is shown. FIG. 8 is an explanatory diagram illustrating an example of a process performed subsequent to FIG. 7, in which a molten resin is injected into a molding cavity, filled, and solidified. It is explanatory drawing which shows the example of a process implemented following FIG. 8, Comprising: The state which released the resin molded product shape | molded in the shaping | molding cavity is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cover panel 12 Design surface 14 Wood grain pattern 16 Wood grain grain 18 Weld line 20 Clear coating 16 Wood grain grain 21 Back 22 Boss 23 Rib 24 Groove-shaped recessed part 25 Veneer 26 Molding molding 30 Projection 32 Injection mold 42 Molding cavity 44 Boss forming recess 46 Rib forming recess 48 Back surface forming part 50 Design surface forming part 52 Resin molded product

Claims (7)

A decoration that expresses the wood texture by forming a concave surface and a grain pattern similar to the fine groove-shaped concave portions present on the surface of the main wood on the design surface having the same color as the main wood. Is a method of manufacturing a decorated resin molded product,
By using the thermosetting resin material or ceramic material that is melted or plasticized at a temperature lower than the combustion temperature of the wood, the fine groove-shaped recesses are molded from the surface of the wood, A step of preparing a mold-molding body having a mold-carrying surface on which fine groove-shaped recesses are transferred and protrusions corresponding to the groove-shaped recesses are formed;
It has the 1st cavity surface containing the design surface formation part which forms the said design surface, and the said mold-molding molded object is a design surface formation part of this 1st cavity surface on the opposite side to the said mold-carrying surface. A first mold fixed on the surface and a back surface forming part for forming a back surface opposite to the design surface, and the decorative resin between the first cavity surface and the mold surface A molten resin material that has a second cavity surface that forms a molding cavity for giving a molded product, and is injected into the molding cavity at the back surface forming portion of the second cavity surface and flows in the molding cavity. a step of preparing a mold for injection molding recess or Ranaru more flow inhibiting unit that inhibits flow and a second mold comprising disposed,
Using the prepared injection mold, a molten resin material having a color similar to that of the main wood is injected into the molding cavity of the injection mold, and the back surface forming portion of the second cavity surface in said plurality of flow-blocking portions provided by allowed to inhibit the flow of the molten resin material, so that the design surface in the weld line occurs, while flowing the molten resin material, the molding cavity After filling, the molten resin material in the molding cavity is solidified to form the wood grain pattern on the design surface by the weld line formed on the design surface. A concave portion corresponding to the fine protrusions on the die-forming surface of the die-molding molded body provided in the design surface forming portion of one cavity surface has the same shape as the fine groove-like concave portion on the surface of the wood. Also A step of forming the 該意 Takumi surface, the on 該意 Takumi surface having the same color and the timber, forming a resin molded article decorated to represent the tree texture has been subjected Te,
The manufacturing method of the decorative resin molded product characterized by including. The plurality of flow inhibiting portions are formed of a boss forming recess and a rib forming recess provided in a back surface forming portion of the second cavity surface of the second mold, and the two recesses are The manufacturing method of the decorative resin molded product according to claim 1, wherein the decorative resin molded product is arranged in a form in which the same size and different sizes are mixed. The manufacture of the decorative resin molded product according to claim 2, wherein the flow inhibition portion including the rib forming recess is provided in a form extending in a direction intersecting with a flow direction of the molten resin material in the molding cavity. Method.   The method for producing a decorated resin molded article according to any one of claims 1 to 3, wherein the molten resin material contains a flaky glitter pigment.   The method further includes a step of forming a transparent coating film on the design surface of the resin molded product on which the concave portion is formed after molding the resin molded product decorated with the wood texture. The manufacturing method of the decorating resin molded product of any one of claim | item 1 thru | or 4.   The method for producing a decorated resin molded article according to claim 5, wherein the transparent coating film is formed using a transparent matte paint. An injection mold for use in the method for producing a decorated resin molded product according to any one of claims 1 to 6,
A decoration that expresses the wood texture by forming a concave surface and a grain pattern similar to the fine groove-shaped concave portions present on the surface of the main wood on the design surface having the same color as the main wood. Is an injection molding die for injection molding a decorative resin molded product to which
By using the thermosetting resin material or ceramic material that is melted or plasticized at a temperature lower than the combustion temperature of the wood, the fine groove-shaped recesses are molded from the surface of the wood, A mold-molding body having a mold-carrying surface on which fine groove-shaped recesses are transferred and protrusions corresponding to the groove-shaped recesses are formed;
It has the 1st cavity surface containing the design surface formation part which forms the said design surface, and the said mold-molding molded object is a design surface formation part of this 1st cavity surface on the opposite side to the said mold-carrying surface. A first mold fixed on the surface of
The said design surface includes a rear surface forming portion for forming a back surface opposite the decorated resin molded with the templating surface in the first cavity surface and the mold cavity molding body that put on the first mold Of a molten resin material having a second cavity surface forming a molding cavity for giving a product, and injected into the molding cavity at a back surface forming portion of the second cavity surface and flowing in the molding cavity. a second mold recessed portion or Ranaru more flow inhibiting unit that inhibits the flow is provided,
A mold for injection molding of a decorative resin molded product, comprising:

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