JP2010119975A - Method of manufacturing in-mold coated article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing in-mold coated article capable of forming a design based on orientation of a magnetic material on a desired place irrespective of a shape on the back surface of an object to be coated. <P>SOLUTION: An in-mold coated mold provided with an object to be coated retention mold 11 and a coating film formation mold 12 in which a magnet 21 is arranged is used, the object 1 to be coated is set to the object to be coated retention mold 11, thereafter, the object to be coated retention mold 11 and the coating film formation mold 12 are closed, a coating cavity 22 for coating the object 1 to be coated with a magnetic paint 2 containing the magnetic material is formed between the object 1 to be coated and the coating film formation mold 12, the magnetic paint 2 is injected into the coating cavity 22, thereafter, an orientation pattern of the magnetic material is formed by the magnet 21, thereafter, the magnetic paint 2 is solidified and, thereby, the magnetic paint 2 is integrally applied on the object 1 to be coated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is mainly used for interior parts of automobiles, exterior parts of mobile phones / portable media players, and other electrical appliances, and a magnetic coating is integrally coated on an object so that a magnetic material forms a desired orientation pattern. The present invention relates to a method for manufacturing an in-mold coated product.

  Conventionally, for coating objects such as resin molded products used for exterior parts of automobiles, home appliances and other electrical appliances, a magnetic paint containing a magnetic material is applied and magnetic material is oriented by applying magnetic force to make it unique. There has been a technique for forming an appearance design (see Patent Documents 1 and 2). In this technique, when the magnetic paint 102 is applied to the surface of the article 101 with the magnet 111 on the back surface of the article 101 by spray coating or the like, the magnetic material 102 is applied to the magnetic paint 102 near the magnet. An alignment pattern is formed (see FIG. 2).

Japanese Patent Laid-Open No. 2003-176252 JP-A-5-31460

  However, when the back surface of the article 101 has a complicated structure, for example, when protrusions such as ribs and bosses are standing and an uneven shape is formed, the magnet 111 cannot be disposed at that portion. For this reason, the range in which the magnetic force can be applied is limited. In addition, when the thickness of the object 101 is large, the distance between the magnet 111 and the magnetic paint 102 on the surface of the object is so large that a sufficient magnetic force may not be applied. In addition, metal powder is often used as the magnetic material, but since the specific gravity increases, there is also a problem that the magnetic coating material 102 is liable to sag before being cured after being coated.

  It is an object of the present invention to provide a method for manufacturing an in-mold coated product so as not to cause the above-described problems.

  In order to achieve the above object, the present invention has the following features.

  The method for producing an in-mold coated product of the present invention uses an in-mold coating mold that includes a coating object holding mold and a coating film forming mold on which magnets are arranged, and the article to be coated is applied to the coating object holding mold. After setting the coating, the coating object holding mold and the coating film forming mold are closed, and a coating cavity for coating the coating object with a magnetic paint containing magnetic material is formed. Formed between the mold, injecting the magnetic paint into the coating cavity, forming an orientation pattern of the magnetic material with a magnet, and then solidifying the magnetic paint to coat the magnetic paint on the object to be coated It is characterized by.

  In the above invention, an orientation pattern of the magnetic material may be formed at least on the surface position of the object to be coated on the opposite side to the position where the uneven shape is formed on the back surface.

  Since the method for producing an in-mold coated product of the present invention includes the steps as described above, it has the following excellent effects.

  According to the present invention, after injecting a magnetic paint containing a magnetic material into a coating cavity, an orientation pattern of the magnetic material is formed by a magnet disposed on the coating film forming mold side, and then the magnetic paint is solidified, thereby Is integrally coated on the workpiece. Therefore, since magnetic force is applied from the front side of the object to be coated, a design based on the orientation of the magnetic material can be formed at a desired place regardless of the shape of the back surface of the object to be coated. In addition, since it is a system in which a coating is filled in a sealed coating cavity, dripping does not occur regardless of the specific gravity of the pigment.

  Embodiments of the present invention will be described in detail with reference to the drawings.

  As the material of the article 1 to be used in the present invention, nonmagnetic metals such as aluminum, plastics, ceramics and the like can be used. Moreover, even if it uses a metal material, it is applicable if a magnet having a strong magnet described later is used. These may be subjected to pretreatment or base coating in advance. Irregular shapes such as bosses 4, ribs, and claw portions may be formed on the back surfaces of these objects to be coated (see FIG. 1).

  The in-mold coating mold used in the present invention includes an object holding mold 11 and a coating film forming mold 12 on which a magnet 21 is arranged. The coating object holding die 11 holds the coating object 1 so as to form a coating cavity 22 between the coating object 1 and the coating film forming mold 12. A coating film is formed on the surface of the coating 1 by a magnetic coating 2 described later (see FIGS. 1A to 1C).

  The coating cavity 22 is a cavity formed for coating the surface of the article 1 with a magnetic paint 2 containing a magnetic material described later. The shape of the coating cavity 22 is appropriately set according to the desired pattern and thickness of the coating film made of the magnetic paint 2. The coating cavity 22 may extend over the entire surface of the object 1 or may be formed only on a part of the object 1. The coating cavity 22 is preferably set so that the thickness of the coating film is about 10 μm to 100 μm.

  The inlet for the magnetic paint 2 may be installed on the coating film forming mold 12 side or on the article holding mold 11 side. The injection position of the magnetic paint 2 may be provided near the center of the coating cavity 22, but after the nozzle pin remains, if the appearance is required, the key hole or emblem mounting position can be used, or the outside of the product The provisional product part may be provided in the container and the injection position may be set there.

  As the magnet 21, a permanent magnet, an electromagnet, a superconducting magnet, or the like can be used. The magnet 21 can be installed at an arbitrary position on the cavity surface of the coating film forming mold 12. The magnet 21 may be disposed directly on the cavity surface. However, if the cavity surface itself is formed of a non-magnetic thin metal plate and the magnet 21 is separately disposed on the back surface of the metal plate, the magnet surface is formed on the coating film surface. It is possible to prevent the boundary line between the member and the nonmagnetic member from appearing, and to obtain a more beautiful finish state.

  The magnetic paint 2 used in the present invention contains a thermosetting paint component and a magnetic material as main components. The magnetic paint 2 does not contain or does not contain a volatile organic solvent like the paint used in conventional spraying and dipping.

  The thermosetting paint components include one-component paints mainly composed of binder components that can be cured by peroxide catalysts such as unsaturated polyester resins, epoxy acrylate oligomers, urethane acrylate oligomers, and epoxy resin / polyamine curing. And two-component paints such as a polyol resin / polyisocyanate curing system in which a main agent / curing agent is mixed immediately before mold injection. Among them, an oligomer containing an acrylate group or an unsaturated polyester resin, or an ethylenically unsaturated monomer copolymerizable with these components and an organic peroxide initiator having a crosslinking efficiency of 8 or more are contained. Liquid paints are excellent in curability, adhesion, appearance, and weather resistance, can shorten the curing time, and can be applied to resin molding materials for which in-mold coating methods cannot be applied due to problems with adhesion, appearance, and weather resistance. It is very good in that it can be applied. Further, a crosslinking agent may be further increased by blending a reaction initiator excited by ultraviolet rays or electron beams and irradiating these energy rays after taking out the in-mold coated product 3 from the mold.

  As said magnetic material, metal powders, such as nickel and iron, can be used. Further, pigments whose surfaces are coated with a magnetic metal may be used using scaly pigments such as mica, aluminum powder, alumina flakes, and glass flakes as a base agent.

  The method for producing the in-mold coated product of the present invention will be described.

  First, the article 1 is set in the article-holding mold 11, and then the article-holding mold 11 and the coating-film-forming mold 12 are closed and covered with a magnetic paint 2 containing a magnetic material. A coating cavity 22 for applying the coating 1 is formed between the coating 1 and the coating film forming mold 12 (see FIG. 1A).

  Next, after injecting the magnetic paint 2 into the coating cavity 22, an orientation pattern of the magnetic material is formed by the magnet 21, and then the magnetic paint 2 is solidified so that the magnetic material forms a desired orientation pattern. The paint 2 can be integrally coated on the article 1 (see FIG. 1B).

The magnetic paint 2 is supplied from, for example, a pump 31 to a paint injector 32, and an accurate amount for one shot is injected from the paint injector 32 into the paint cavity 22 with an appropriate pressure (FIGS. 1A and 1B). )reference). The injection time of the magnetic paint 2 is about 1 to 10 seconds, and is appropriately set depending on the material of the magnetic paint 2 and the size of the coating cavity 22. The injection pressure of the magnetic coating material 2 is suitably set within a range of about 10 to 400 kgf / cm ² , but it is preferable to set the pressure higher in order to prevent burrs and bubbles in the coating film. In order to prevent the magnetic paint 2 from being injected after the nozzle, it is preferable to use a keyhole, an emblem mounting position, or the like, or provide a temporary product portion outside the product and install it there.

  As a viscosity of the magnetic coating material 2, it sets suitably according to a pattern and thickness within the range of 2000-7000 mPa * s. Particularly in the case of the present invention, the coating material holding mold 11 and the coating film forming mold 12 have almost no gap other than the cavity and can be fixed with a strong clamping pressure. As the metal powder is used, it does not cause dripping even when the specific gravity increases, and it is advantageous in that the magnetic paint 2 does not leak from the coating cavity 22 even if the magnetic paint 2 has a very low viscosity that easily leaks. It is.

  The mold temperatures of the article holding mold 11 and the coating film forming mold 12 are set by a mold temperature controller. The medium of the mold temperature controller may be water or oil. The mold temperature of the coating film forming mold 12 is set to a temperature at which the magnetic paint 2 is cured within a few seconds depending on the material of the magnetic paint 2.

  Finally, when the article holding mold 11 and the coating film forming mold 12 are opened, the in-mold coated product 3 can be taken out (see FIG. 1C).

  Here, since the magnet 21 is disposed on the coating film forming mold 12 side and applies a magnetic force from the front side of the object 1 to be coated, for example, a boss 4, a rib, a nail portion, etc. on the back surface of the object 1 to be coated Even if the concavo-convex shape is formed, a design based on the orientation pattern of the magnetic material can be formed at a desired location regardless of the shape of the back surface of the object to be coated.

  A resin part provided with a boss for housing casing on the outer periphery of the back surface and having an orientation pattern design made of a magnetic material at the surface position opposite to the boss formation position was formed by the following procedure.

  Made of in-mold coating mold with coating object holding mold and coating film forming mold with electromagnet arranged, and made of black polycarbonate with boss for housing saddle on the back outer periphery as coating object After the resin parts are set in the object holding mold, the object holding mold and the coating film forming mold are closed, and the object to be coated with the magnetic paint containing the magnetic material. A coating cavity was formed between the object to be coated and the film forming mold. Then, a two-component curable urethane urethane ink in which 10% of a magnetic powder material (stainless steel, scale shape, longitudinal particle size of 10 to 30 μm) was mixed as a magnetic coating material was injected into the coating cavity. After an orientation pattern is formed on the magnetic material by an electromagnet attached to the coating film forming mold, the magnetic paint is solidified by the mold heat (mold temperature set at 90 ° C), and the mold is opened to obtain an in-mold coated product. It was. The electromagnet placed in the coating film forming mold is placed near the resin part surface position on the opposite side of the boss formation position. An orientation pattern was formed, a unique design was provided, and the appearance was excellent.

It is sectional drawing which shows the manufacturing method of the in-mold coating goods of this invention. It is sectional drawing which shows the manufacturing method of the conventional coating goods.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coated object 2 Magnetic paint 3 Coated product 4 Boss 11 Coated object holding mold 12 Coating film forming mold 21 Magnet 22 Painting cavity 31 Pump
32 Paint Injection Machine 101 Workpiece 102 Magnetic Paint 111 Magnet

Claims (2)

Using an in-mold coating mold comprising an object holding mold and a coating film forming mold on which magnets are arranged,
After setting the object to be coated in the object holding mold, the object holding mold and the coating film forming mold are closed, and the object to be coated is coated with a magnetic paint containing a magnetic material. A coating cavity is formed between an object to be coated and a coating film forming mold, magnetic paint is injected into the coating cavity, an orientation pattern of the magnetic material is formed by a magnet, and then the magnetic paint is solidified to solidify the magnetic coating. A method for producing an in-mold coated product, characterized in that a paint is integrally coated on an object to be coated. The method for producing an in-mold coated product according to claim 1, wherein an orientation pattern of the magnetic material is formed at least on the surface position of the object to be coated opposite to the position where the uneven shape is formed on the back surface.

Images