JP3500236B2 - Manufacturing method of acrylic insert film and acrylic insert molded product - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a surface material for furniture,
For interior and exterior materials for buildings, surface materials for cabinets, interior materials for kitchen doors, automotive interior and exterior parts, etc.
TECHNICAL FIELD The present invention belongs to a technical field relating to an acrylic insert film used for producing an insert-molded product having a pattern such as a wood grain pattern and a method for producing an acrylic insert-molded product using the insert film.

[0002]

2. Description of the Related Art Conventionally, as a material used as an automobile interior part having a pattern such as a wood grain pattern, there is an insert molded product obtained by an insert molding method using an acrylic insert film. The insert molding method using an acrylic insert film is an acrylic insert film in which a pattern ink layer such as a wood grain pattern ink layer is printed on an acrylic film substrate, is supplied into the injection molding die, and the molten resin is closed after the die is closed. It is a method of adhering the ink layer side of the acrylic insert film to a resin molded product by injecting it into a mold and solidifying the resin.

The reason why the acrylic film substrate is used is that the acrylic film has a superior light resistance as compared with a PET film because the acrylic film has a molecular structure that makes it difficult for light rays harmful to ink to pass therethrough. An advantage of excellent "light resistance" is that, for example, fading or damage of the design ink layer caused by direct exposure of natural light or room light to the design ink layer can be effectively suppressed. Further, since the acrylic film deforms (elongates) even at a low temperature, the workability of the entire insert film is superior to that of the PET film and the like. The advantage of excellent "workability" is that, for example, the shape of the inner surface of the cavity of the injection mold is a complicated shape such as unevenness with many holes and grooves, Even if the insert film uses an acrylic film as the base sheet, it has a complicated shape and a deep rise on the inner surface of the cavity of the injection mold due to heating and vacuum suction. This is because it is possible to obtain an insert-molded product that is deformed into a shape and exhibits a surface shape similar to the shape of the inner surface of the cavity of the injection molding die.

[0004]

Problems to be solved by the conventional acrylic insert film will be described below. The acrylic film is located on the outermost surface of the insert molded article in order to protect the pattern ink layer. Although the acrylic film is excellent in light resistance and processability, it is inferior in fusion resistance and plasticizer migration resistance to PET films and the like. Fusing property means, for example, if the license case made of vinyl chloride and the acrylic film insert molded product are in contact with each other and exposed to high temperature such as in hot weather, the license case will be fused. Then, it refers to a problem such as sticking to the insert molded product and making it difficult to peel off easily. The term "plasticizer migration" often means that the resin sheet contains a plasticizer (for example, phthalate ester, phosphate ester, etc.) so that the hard resin sheet exhibits flexibility. When the sheet and the acrylic film are in contact with each other and exposed to high temperature such as under hot weather, the plasticizer of the resin sheet moves to the acrylic film side and attacks the surface of the acrylic film, so that the acrylic film surface is It refers to defects such as whitening and flesh-like appearance.

The problems of the conventional method for manufacturing an acrylic insert molded product are shown below. In the insert molding method, in order to supply the insert film into the injection molding die, the continuously printed insert film is wound into a roll and continuously sent out to the injection molding die. However, since the acrylic film substrate has low solvent resistance, the acrylic film substrate and the adhesive layer may adhere to each other due to the action of the solvent in the adhesive layer when the insert film is wound up. For this reason, the insert film is torn or unnecessary substances are attached to the acrylic film substrate. On the other hand, in order to solve this problem, it is conceivable to strongly dry the adhesive layer to reduce the solvent in the adhesive layer, but in this case, deformation such as elongation of the acrylic film substrate due to heat during drying may occur. I will wake you up. For this reason, the design is deformed and the alignment with the injection molding die cannot be performed accurately, so that the production efficiency of the insert-molded product is very low.

The present invention solves the above-mentioned drawbacks, and not only has good light resistance and processability, but also good adhesion resistance and plasticizer migration resistance, and an acrylic insert film with good production efficiency. It is an object of the present invention to provide a method for manufacturing an acrylic insert molded product.

[0007]

In order to achieve the above object, the acrylic insert film of the present invention has a surface of a transparent base sheet containing an acrylic resin as a main component, as described in claim 1. Then, a transparent overcoat layer having a cellulose resin was formed, and a pattern ink layer and an adhesive layer were sequentially formed on the back surface.

Further, as described in claim 2, the overcoat layer contains 70% by weight or more of the cellulose resin.

Further, as described in claim 3, the cellulosic resin is a cellulose acetate resin.

Further, as described in claim 4, the cellulosic resin is a nitrocellulose resin.

Further, as described in claim 5, the cellulose resin is ethyl cellulose resin.

Further, as described in claim 6, the pattern ink layer comprises a wood grain layer and an opaque base layer.

According to the method for producing an acrylic insert molded article of the present invention, as described in claim 7, the acrylic insert film according to any one of the present invention is placed in an injection molding die and the die is closed. After that, a molten resin was injected into the mold to solidify the resin, so that the acrylic insert film was bonded to the resin molded product.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing an acrylic insert film and an acrylic insert molded article according to the present invention will be described in more detail below.

In the acrylic insert film of the present invention, a transparent overcoat layer 2 having a cellulosic resin is formed on the surface of a transparent base sheet 1 containing an acrylic resin as a main component, and a pattern ink layer (wood grain layer) on the back surface. 4, an opaque underlayer 5) and an adhesive layer 6 are sequentially formed (FIG. 1).

The transparent base sheet 1 is a transparent resin sheet containing an acrylic resin as a main component. A transparent resin sheet containing an acrylic resin as a main component has a molecular structure that makes it difficult for light rays harmful to ink to pass therethrough, and therefore has excellent light resistance as compared with a PET film or the like.
An advantage of excellent "light resistance" is that, for example, fading or damage of the design ink layer caused by direct exposure of natural light or room light to the design ink layer can be effectively suppressed. Further, since the transparent resin sheet containing an acrylic resin as a main component is deformed (stretched) even at a low temperature, the workability of the entire insert film is superior to that of a PET film or the like. The advantage of being excellent in "workability" is that, for example, the shape of the inner surface of the cavity 70 of the injection molding die 7 is a complicated shape such as unevenness with many holes or grooves formed. Even if it has a shape with deep rising recesses, an insert film using a transparent resin sheet containing an acrylic resin as a main component as a base sheet can be heated or vacuum sucked into an injection molding die. That is, it is possible to obtain an insert-molded product that is deformed to have a complicated shape or a deep rising shape of the inner surface of the cavity 70 of 7 and has a surface shape of the inner surface of the cavity 70 of the injection molding die 7. .

As the transparent substrate sheet 1 containing an acrylic resin as a main component, not only an acrylic film made of a pure acrylic resin such as polymethylmethacrylate, polyethylmethacrylate, polypropylmethacrylate, polybutylmethacrylate, etc. , A film of a component composed of a copolymer of an acrylic resin and another resin (for example, a fluororesin, a polystyrene resin, a polypropylene resin, a polyvinyl chloride resin, a polyester resin, a silicone resin), an acrylic film and another plastic film ( For example, a laminated film with a fluorine film, a polypropylene film, a polyvinyl chloride film, a polyester film, a polyethylene vinyl acetate film, a polycarbonate film, etc.) is also included. As a method for laminating the laminated film, there are various laminating methods such as direct laminating and dry laminating and methods by a heat sealing method. When a biaxially stretched polyester film or a biaxially oriented polypropylene film and a pure acrylic film are laminated to form a base sheet, the elongation of the film is worse than that of the pure acrylic film. It is preferable to use a relatively thin film as the polypropylene film rather than a pure acrylic film.

The thickness of the base sheet 1 is 10 μm to 500 μm.
Although it is μm, it is preferably 50 μm or more in order to obtain sufficient light resistance. Also, in order to obtain sufficient workability, 30
It is preferably 0 μm or less. In the case of methyl methacrylate, there are 125 μm, 200 μm, etc. as the thickness for having both good light resistance and good processability at the same time.

Specific examples of the cellulose resin used in the overcoat layer 2 include cellulose acetate resin, nitrocellulose resin, ethyl cellulose resin, hydroxypropyl cellulose resin, cellulose propionate resin, methyl cellulose resin, benzyl cellulose resin and carboxymethyl cellulose resin. The three types of cellulose acetate resin, nitrocellulose resin, and ethyl cellulose resin are all of fusion resistance, plasticizer migration resistance, flexibility, solvent resistance, printability (points that are easy to use as a printing ink), etc. It is especially effective because it has both. When the content of these cellulosic resins in the overcoat layer 2 is 70% by weight or more, sufficient plasticizer migration resistance can be secured. The fusion resistance is, for example, the case of a license made of vinyl chloride and the case of a license that is in contact with the overcoat layer 2 and exposed to a high temperature such as in the hot sun. It means that it can be easily peeled off without sticking to the coat layer. The plasticizer migration resistance means that the resin sheet containing a plasticizer such as phthalate ester or phosphate ester is in contact with the overcoat layer 2, and is exposed to a high temperature such as in the hot sun. Also, it means that the plasticizer of the resin sheet does not migrate to the side of the overcoat layer 2 and invade the overcoat layer 2, and as a result, the overcoat layer 2 does not become white or become dull. Flexibility means that it is easy to bend and stretch.

When cellulose acetate is used as the overcoat layer 2, the chemical resistance and oil resistance are further enhanced at least as compared with the nitrocellulose resin and the ethyl cellulose resin. Cellulose acetate resin has a lower flammability than at least nitrocellulose. A cellulose acetate resin having a degree of acetylation of 50 to 60 and an average degree of polymerization of about 100 to 250 is particularly easy to be made into an ink. For converting the cellulose acetate resin into an ink, it is preferable to dissolve the powder of the cellulose acetate resin in a ketone-based, alcohol-based, or ester-based organic solvent to form an ink.

Since at least the nitrocellulose resin has higher drying property and mechanical strength than the cellulose acetate or ethyl cellulose resin, it is easy to use as an ink to be used when the overcoat layer 2 is formed by gravure printing or flexographic printing. Further, the texture and smoothness of the overcoat layer 2 are improved.

The ethyl cellulose resin has lower flammability and higher light resistance than at least the nitrocellulose resin. The ethyl cellulose resin can be easily used for screen printing because it has a wide selection of organic solvents used when it is made into an ink.

In order to further improve the hardness and surface strength of the overcoat layer 2, a cross-linking agent such as polyisocyanate or melamine resin may be contained. Further, in order to improve the adhesiveness of the overcoat layer 2 to the base sheet 1, other cellulosic resin, acrylic resin, urethane resin, polyester resin or the like may be contained.

The overcoat layer 2 may be an ink layer formed on the base sheet 1 by various printing methods or coating methods, or the base sheet 1 and the film-shaped overcoat layer 2 may be coextruded. It may be laminated. The overcoat layer 2 preferably has a film thickness of 0.2 μm to 20 μm. The printing method includes an offset printing method, a gravure printing method, a screen printing method, and a flexo printing method. Examples of the coating method include a roll coating method and a spray coating method. As a specific example of the co-extrusion method, the substrate sheet 1 is extruded by an extruder to be extruded into a film-shaped or sheet-shaped substrate sheet, and at the same time, the overcoat layer 2 is extruded by an extruder to form a film-shaped or sheet-shaped overcoat. The layer 2 is formed on the surface of the base sheet 1 to form a sheet having a two-layer structure.

As the design of the design ink layer, there are wood grain design, characters, symbols, numbers and the like. Hereinafter, as an example of the pattern ink layer, a wood grain pattern layer including the wood grain layer 4 and the opaque base layer 5 will be described. The pattern ink layer may be formed by using various pigments or dyes, or a bright pigment ink layer mixed with pearl powder or aluminum powder, or a metal vapor deposition layer.

The wood grain layer 4 is a layer for expressing a wood grain pattern such as annual rings, fibers and conduits that appear at the cut end when the wood is cut. Specific wood grain patterns include streaks, curved lines, and line breaks. The wood grain layer 4 uses a thermoplastic resin such as vinyl chloride / vinyl acetate copolymer, polyamide, polyester, polyacrylic, polyurethane, chlorinated rubber, or nitrified cotton as a binder, and contains a dye or pigment having a wood grain pattern as a coloring material. Select a single color or multiple colors from brown, dark brown, ocher, reddish brown, etc. The wood grain layer 4 is formed by a usual printing method such as an offset printing method, a gravure printing method, a screen printing method, a flexographic printing method, or a coating method such as a roll coating method or a spray coating method. Alternatively, wood grain layer 4
May be formed on a part or the whole surface of the base sheet 1 by gradation so that the color density or the film thickness is changed stepwise or continuously in order to make it closer to the natural wood grain pattern. The thickness of the wood grain layer 4 is 0.5μ
Adjust within the range of m to 5 μm.

The opaque underlayer 5 is a layer that expresses the color of the wood other than the wood grain that appears at the cut end when the wood is cut. The opaque underlayer 5 contains a thermoplastic resin such as vinyl chloride / vinyl acetate copolymer, polyamide, polyester, polyacryl, polyurethane, chlorinated rubber, or nitrified cotton as a binder, and contains a dye or pigment of the underlayer color as a coloring material. Select a single color or multiple colors from colors such as brown, dark brown, ocher, cream, yellow, and reddish brown. If necessary, the color may be selected to be darker than the color selected for the wood grain layer 4, or may be selected to be a light color. The opaque base layer 5 is formed by a usual printing method such as an offset printing method, a gravure printing method, a screen printing method, a flexographic printing method, or a coating method such as a roll coating method or a spray coating method. The suitable thickness of the opaque underlayer 5 is 2 μm to 10 μm.

The adhesive layer 6 may be made of acrylic resin, urethane resin, polyester resin, polyamide resin, ethylene butyl alcohol resin, ethylene vinyl acetate copolymer, vinyl chloride / vinyl acetate copolymer, or the like.

The acrylic insert film of the present invention has a transparent first base sheet 10 containing an acrylic resin as a main component and a transparent second base sheet 11 containing an acrylic resin as a main component. A transparent overcoat layer 2 made of a cellulosic resin is formed on the surface of the sheet 10, and a wood grain layer 4, a laminating adhesive layer 3, and a second layer are formed on the back surface.
The base sheet 11, the opaque base layer 5, and the adhesive layer 6 are sequentially formed (FIG. 2). In this configuration, the wood grain layer 4 and the opaque base layer 5 are separated from each other with the second base sheet 11 sandwiched therebetween, so that it is possible to obtain a wood grain pattern having a three-dimensional effect in which the wood grain is raised from the base. Is advantageous. The first base sheet 10 and the second base sheet 11 are the same as the base sheet 1. First base sheet 10,
Regarding the method of laminating the wood grain layer 4 and the second base sheet 11, for example, the first base sheet 10 having the wood grain layer 4 formed thereon and the second base sheet 11 are laminated by laminating with the laminating adhesive layer 3.

The method for producing an acrylic insert molded article of the present invention is a method for producing the acrylic insert film by the insert molding method using the acrylic insert film. That is, the acrylic insert film is placed in a mold for injection molding, and after the mold is closed, a molten resin is injected into the mold and the resin is solidified to bond the acrylic insert film to the resin molded product. Yes (FIG. 3, FIG. 4, FIG. 5).

The injection molding die 7 used in this manufacturing method comprises a movable die and a fixed die. When arranging the acrylic insert film in the injection mold, the individual acrylic insert films may be fed and arranged one by one, or the necessary parts of the long acrylic insert film may be intermittently fed and arranged. You may. When a long acrylic insert film is used, it is advisable to use a feeder having a positioning mechanism so that the pattern layer of the acrylic insert film and the molding die are in register. Further, when the acrylic insert film is intermittently fed and arranged, if the position of the acrylic insert film is detected by the sensor and then the acrylic insert film is fixed by the movable mold and the fixed mold, the acrylic insert film is always at the same position. It is convenient because the insert film can be fixed and the position of the design of the design ink layer does not shift. After the acrylic insert film is arranged, the acrylic insert film is brought into close contact with the inner surface of the movable concave portion (the concave portion may be referred to as “cavity”) by vacuum suction or heating. Then, the injection molding die is closed to form the cavity 70 (FIG. 3).
The molten resin 9 is fed into the cavity 7 through the injection port 8 provided in the fixed mold.
0 is injection-filled to solidify the resin to form the resin molded product 12, and at the same time, the acrylic insert film is adhered to the surface. After cooling the resin molded product 12, the injection molding die is opened and the resin molded product is taken out. In this way, an acrylic insert molded product can be obtained.

[0032]

Example A 200 μm thick methyl methacrylate film was used as the base sheet. On the surface of the base sheet,
An overcoat layer composed of 80% by weight of cellulose acetate resin, 10% by weight of urethane diisocyanate and 10% by weight of thermoplastic acrylic resin was formed by a gravure printing method. A wood grain layer (weight%: resin binder / pigment = 60/40) made of a resin binder made of a polyvinyl chloride resin and a brown pigment was formed on the back surface of the base sheet by a gravure printing method. An opaque underlayer (% by weight: resin binder / pigment = 60/40) composed of a resin binder composed of a polyvinyl chloride resin and a black pigment was formed on the wood grain layer by a gravure printing method. An adhesive layer made of vinyl chloride vinyl acetate copolymer resin was formed on the opaque underlayer by a gravure printing method to obtain an acrylic insert film having a grain pattern.

The acrylic insert film having a wood grain pattern obtained as described above is placed in an injection molding die consisting of a movable die and a fixed die for producing a gearbox panel, and the acrylic insert film is heated to 95 ° C. Vacuum suction was performed while heating at, and it was brought into close contact with the concave portion of the movable mold. After closing the mold, while maintaining the mold temperature at 40 ° C to 60 ° C, 220
A molten resin composed of a brown acrylonitrile butadiene polystyrene copolymer resin heated to ℃ to 250 ℃ was injected into the mold to solidify the resin.

[0034]

Since the present invention has the above-mentioned structure and operation, the following effects can be obtained. That is, since the acrylic insert film of the present invention uses a transparent sheet containing an acrylic resin as a main component as a base sheet of the insert film, it has excellent light resistance and workability. Further, since the transparent overcoat layer made of a cellulosic resin is present on the base sheet, the overcoat layer reinforces the fusion resistance and the plasticizer migration resistance, which are weak points of the acrylic sheet. Therefore, the acrylic insert film of the present invention can be used for producing an acrylic insert molded article excellent in all of light resistance, processability, fusion resistance and plasticizer migration resistance.

Further, the method for producing an acrylic insert-molded product of the present invention uses an acrylic insert film having a transparent sheet containing an acrylic resin as a main component as a base sheet and has good workability. It is possible to obtain an insert-molded product that is deformed to have a complicated shape of the cavity inner surface of the injection molding die or a deep rising shape, and has a surface shape similar to the shape of the cavity inner surface of the injection molding die. Furthermore, the cellulosic resin used as the overcoat layer is unlikely to adhere to other printing layers. Therefore, by winding the continuously printed insert film, the overcoat layer and the adhesive layer do not adhere to each other when being rolled, and since it is not necessary to strongly dry the adhesive layer,
The production efficiency of insert-molded products will surely improve.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an acrylic insert film of the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of another aspect of the acrylic insert film of the present invention.

FIG. 3 is a cross-sectional view showing one of the manufacturing steps of the acrylic insert-molded product of the present invention.

FIG. 4 is a cross-sectional view showing one of the manufacturing steps of the acrylic insert-molded product of the present invention.

FIG. 5 is a sectional view showing an acrylic insert molded product of the present invention.

[Explanation of symbols]

1 Base sheet 2 Overcoat layer 3 Laminating adhesive layer 4 wood layers 5 Opaque underlayer 6 Adhesive layer 7 Injection mold 8 exit 9 Molten resin 10 First Base Sheet 11 Second base sheet 12 Resin molded products

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (5)

(57) [Claims] 1. A transparent base sheet having an acrylic resin as a main component, a transparent overcoat layer having a cellulose acetate resin is formed on the surface, and a pattern ink layer and an adhesive layer are sequentially formed on the back surface. And acrylic insert film. 2. A transparent base sheet having an acrylic resin as a main component, a transparent overcoat layer having a nitrocellulose resin is formed on the surface, and a pattern ink layer and an adhesive layer are sequentially formed on the back surface. And acrylic insert film. 3. A transparent base sheet containing an acrylic resin as a main component, a transparent overcoat layer having an ethyl cellulose resin is formed on the surface, and a pattern ink layer and an adhesive layer are sequentially formed on the back surface. Acrylic insert film. 4. The acrylic insert film according to claim 1, wherein the pattern ink layer comprises a wood grain layer and an opaque underlayer. 5. The acrylic insert film according to any one of claims 1 to 4 is placed in a mold for injection molding, the mold is closed, and then a molten resin is injected into the mold to solidify the resin. A method of manufacturing an acrylic insert-molded product, which comprises bonding the acrylic insert film to the resin-molded product by performing the above.