JP6398259B2 - Decorative sheet and decorative resin molded product - Google Patents

Description

  The present invention relates to a decorative sheet provided with a heat sealing layer, which is applied to an overlay method.

  Conventionally, a decorative resin molded product in which a decorative sheet is laminated on the surface of a resin molded product is used for an interior / exterior part of a vehicle, a building material interior material, a home appliance housing, and the like. In the production of such a decorated resin molded product, a molding method or the like is used in which a decorative sheet to which a design has been applied in advance is integrated with a resin by injection molding. As a typical example of such a molding method, a decorative sheet is formed in a three-dimensional shape in advance by a vacuum mold, the decorative sheet is inserted into an injection mold, and a resin in a fluid state is injected into the mold. The injection molding method that integrates the resin and the decorative sheet, and the injection molding that integrates the decorative sheet inserted into the mold during the injection molding with the molten resin injected into the cavity The decoration method is mentioned. In addition to the molding method by injection molding, a decorative sheet is also used in a decoration method called an overlay method, which is attached to a pre-molded molded body with heating or pressurization (for example, Patent Document 1).

  Further, in Patent Document 2, in such an overlay method, the image layer is applied to the surface of the workpiece by heating and melting the adhesive layer of the transfer film having the image layer and bringing it into contact with the surface of the workpiece (molding resin). A method of painting is disclosed. According to the method disclosed in Patent Document 2, it is expected that it will be easy to deal with a variety of small-lot production, and further variations of decorative resin molded products can be developed.

Japanese Examined Patent Publication No. 56-45768 JP 2012-101549 A

When the method disclosed in Patent Document 2 is applied to a decorative sheet, high adhesion is maintained even after molding in addition to high adhesion when softening the decorative sheet to follow the shape of the molded product. Is required. In particular, decorative resin molded products used for vehicle interior / exterior parts, building material interior materials, home appliance housings, and the like, as described above, may be exposed to high temperatures, so high adhesion at high temperatures after molding. Is required. However, in decorative sheets with a heat-sealing layer applied to the overlay method, in addition to high adhesion at the time of molding, it is added to exhibit high adhesion even when exposed to high temperatures after molding. The present condition that the requirements which a decoration sheet should have is not fully examined. For this reason, it may become a hindrance to apply an overlay method to manufacture of the decorating resin molded product using the decorating sheet provided with a heat-fusion layer.
Under such circumstances, the present invention is a decorative sheet provided with a heat-sealing layer applied to the overlay method, in addition to high adhesion during molding, and also when exposed to high temperatures after molding The main purpose is to provide a decorative sheet having high adhesion.

  The present inventor has intensively studied to solve the above problems. As a result, in the decorative sheet provided with the heat-sealing layer used in the overlay method, the decorative sheet is a laminate in which at least the base material layer and the heat-sealing layer are laminated, and the thickness of the laminate is further increased. By setting the glass transition temperature of the heat fusion layer in the range of 200 to 400 μm in the range of 65 to 85 ° C., in addition to high adhesion during molding, high adhesion even when exposed to high temperatures after molding It has been found that a decorative sheet having properties can be obtained. The present invention has been completed by further studies based on such findings.

That is, this invention provides the invention of the aspect hung up below.
Item 1. The decorative sheet having the heat-fusible layer is softened by heating, and the decorative sheet is formed by following the shape of the molded resin, and the heat-fused layer is heat-fused to the molded resin to form the decorative sheet. A decorative sheet used in an overlay method for producing a decorative resin molded product in which the molding resin is decorated with a decorative sheet,
The decorative sheet is composed of a laminate in which at least a base material layer and a heat sealing layer are laminated,
The thickness of the laminate is in the range of 200 to 400 μm,
The decorating sheet whose glass transition temperature of the said heat-fusion layer exists in the range of 65-85 degreeC.
Item 2. Item 2. The decorative sheet according to Item 1, further comprising a surface protective layer.
Item 3. Item 3. The decorative sheet according to item 1 or 2, further comprising a decorative layer.
Item 4. Item 4. The decorative sheet according to any one of Items 1 to 3, comprising a laminate in which the heat-fusible layer, the base material layer, and the surface protective layer are laminated in this order.
Item 5. Item 5. The decorative sheet according to Item 4, comprising a laminate in which at least one of a primer layer and a decorative layer is laminated between the base material layer and the surface protective layer.
Item 6. Item 2. The decorative sheet according to Item 1, comprising a laminate in which the heat-fusible layer, a decorative layer, and the base material layer are laminated in this order.
Item 7. Item 7. A decorative resin molded product, wherein the heat-sealing layer of the decorative sheet according to any one of Items 1 to 6 is laminated on a molded resin layer.
Item 8. The manufacturing method of a decorative resin molded product provided with the following processes 1-5.
Step 1: The thermal adhesive layer of the decorative sheet according to any one of Items 1 to 6 is opposed to the molding resin, and the inside of the chamber is divided in an airtight manner through the decorative sheet. The process of arrange | positioning a decorating sheet and the said shaping | molding resin in a chamber Process 2: The inside of the said chamber is pressure-reduced so that the one side and the other side in the said chamber divided | segmented via the said decorating sheet may become the same pressure. And the step of heating and softening the decorative sheet in the chamber Step 3: Canceling the decompression on the opposite side to the molding resin in the chamber divided through the decorative sheet, Step of forming the decorative sheet softened by heating following the shape of the molding resin Step 4: Step of heat-sealing the decorative sheet and the molding resin via the heat-sealing layer Step 5: The decorative sheet The step of releasing the pressure reduction on the side of the molding resin in the chamber divided through the step and taking out the decorative resin molded product

  According to the present invention, a decorative sheet comprising a heat-sealing layer applied to the overlay method, in addition to high adhesion at the time of molding, high adhesion even when exposed to a high temperature after molding. The decorative sheet which has can be provided. Furthermore, according to the present invention, a decorative resin molded product using the decorative sheet can be provided.

It is a schematic sectional drawing of an example of the decorating sheet of this invention. It is a schematic sectional drawing of an example of the decorating sheet of this invention. It is a schematic sectional drawing of an example of the decorating resin molded product of this invention. It is a schematic sectional drawing of an example of the decorating resin molded product of this invention.

1. Decorating sheet The decorating sheet of the present invention is a decorating sheet used in the overlay method. Here, in the present invention, the overlay method is a method in which a decorative sheet having a heat-sealing layer is softened by heating, and the decorative sheet is formed to follow the shape of the molding resin, while the heat-sealing layer is molded resin. It is a method for producing a decorated resin molded product in which a molded resin is decorated with a decorative sheet. The decorative sheet of the present invention comprises a laminate in which at least a base material layer and a heat fusion layer are laminated, the thickness of the laminate is in the range of 200 to 400 μm, and the heat fusion layer. The glass transition temperature is in the range of 65 to 85 ° C. The decorative sheet of the present invention has such a configuration, so that when applied to an overlay method using a decorative sheet having a heat-sealing layer, in addition to high adhesion at the time of molding, a high temperature after molding. High adhesion when exposed underneath. As will be described later, the decorative sheet of the present invention may not have a decorative layer or the like, and may be transparent, for example. Hereinafter, the decorative sheet of the present invention will be described in detail.

Laminated structure of decorative sheet The decorative sheet of the present invention has at least a base material layer 1 and a heat fusion layer 2. Moreover, the decorative sheet of this invention may provide the surface protective layer 3 as an outermost layer as needed for the purpose of protecting the surface of the decorative sheet. Moreover, you may provide the primer layer 4 under the surface protective layer 3 as needed for the purpose of improving the adhesiveness of the surface protective layer 3 and the layer adjacent to this. Moreover, you may provide the decoration layer 5 as needed for the purpose of providing a decorating property to a decorating sheet. Moreover, you may provide the concealment layer 7 as needed in order to suppress the change of color and variation of a decorating sheet.

  As a laminated structure of the decorative sheet of the present invention, a laminated structure in which a heat-fusible layer / base material layer is laminated in this order; a laminated structure in which a heat-fusible layer / base material layer / surface protective layer is laminated in this order; Laminated structure in which fusion layer / base material layer / primer layer / surface protective layer are laminated in this order; Laminated structure in which heat fusion layer / base material layer / decoration layer / surface protective layer are laminated in this order; thermal fusion Examples include a laminated structure in which a layer / base material layer / decoration layer / primer layer / surface protective layer are laminated in this order; a laminated structure in which a heat fusion layer / decoration layer / base material layer is laminated in this order. FIG. 1 is a schematic view of an example of a decorative sheet in which a heat fusion layer / base material layer / decoration layer / primer layer / surface protective layer are laminated in this order as one embodiment of the laminated structure of the decorative sheet of the present invention. A cross-sectional view is shown. FIG. 2 shows a schematic cross-sectional view of an example of a decorative sheet in which a heat-sealing layer / decorative layer / base material layer is laminated in this order as an aspect of the laminated structure of the decorative sheet of the present invention.

(Thickness of decorative sheet)
In the decorative sheet of the present invention, the total thickness of the laminate constituting the decorative sheet needs to be in the range of 200 to 400 μm. In this invention, when the thickness of a decorating sheet exists in such a specific range, and the glass transition temperature (Tg) of the heat bonding layer 2 mentioned later exists in the specific range of 65-85 degreeC, In a decorative sheet provided with a heat-sealing layer applied to the overlay method, in addition to high adhesion at the time of molding, it also has high adhesion when exposed to high temperatures after molding.

  From the viewpoint of further improving the adhesion at the time of molding and under high temperature, the total thickness of the laminate constituting the decorative sheet is preferably about 200 to 350 μm, more preferably about 220 to 300 μm. In addition, in this invention, the total thickness of the laminated body which comprises a decorating sheet is the value measured using the thickness meter (Nikon Corporation Digimicro MF-501).

Composition of each layer forming the decorative sheet [base material layer 1]
The base material layer 1 is a layer provided for the purpose of improving the shape retention of the decorative sheet of the present invention. Moreover, when it laminates | stacks so that the base material layer 1 may be located in the outermost layer of a decorative resin molded product, it functions also as a surface protective layer of a decorative resin molded product. The base material layer 1 is preferably formed of a resin sheet (resin film).

  The resin component used for the base material layer 1 is not particularly limited, and when it functions as a three-dimensional moldability or a surface protective layer of a decorative resin molded product, it is appropriately selected according to scratch resistance, chemical resistance, and the like. Although it may be selected, a thermoplastic resin is preferable. Specific examples of the thermoplastic resin include acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as “ABS resin”); acrylonitrile-styrene-acrylic ester resin; acrylic resin; polyolefins such as polypropylene and polyethylene Resin; Polycarbonate resin; Vinyl chloride resin; Polyethylene terephthalate (PET) resin. Among these, ABS resin is preferable from the viewpoint of three-dimensional moldability. Moreover, when the base material layer 1 is laminated so as to be positioned in the outermost layer of the decorative resin molded product, an acrylic resin is preferable. As a resin component which forms the base material layer 1, only 1 type may be used and 2 or more types may be mixed and used. Moreover, the base material layer 1 may be formed with the single layer sheet | seat of these resin, and may be formed with the multilayer sheet | seat by the same kind or different kind | species resin.

  The base material layer 1 may be subjected to physical or chemical surface treatment such as an oxidation method or an unevenness method on one side or both sides as necessary in order to improve the adhesion between adjacent layers. . Examples of the oxidation method performed as the surface treatment of the base material layer 1 include a corona discharge treatment, a plasma treatment, a chromium oxidation treatment, a flame treatment, a hot air treatment, and an ozone ultraviolet treatment method. Moreover, as the uneven | corrugated method performed as surface treatment of the base material layer 1, a sandblasting method, a solvent processing method, etc. are mentioned, for example. These surface treatments are appropriately selected according to the type of the resin component constituting the base material layer 1, and preferably a corona discharge treatment method from the viewpoints of effects and operability.

  In addition, the base material layer 1 may be colored with a colorant or the like, painted for adjusting the color, formation of a pattern for imparting design properties, or the like.

The thickness of the base material layer 1 is not particularly limited and is appropriately set depending on the use of the decorative sheet,
Usually, about 180-350 micrometers, Preferably about 200-300 micrometers is mentioned. When the thickness of the base material layer 1 is within the above range, the decorative sheet can be provided with more excellent three-dimensional formability, designability, and the like.

[Heat-fusion layer 2]
The heat sealing | fusion layer 2 is a layer provided in order to adhere a decorating sheet and the shaping | molding resin layer 6 using an overlay method. In the decorative sheet of the present invention, the thermal adhesive layer 2 is laminated on the back surface (molded resin layer 6 side) of the layer laminated with the molded resin layer 6 such as the base layer 1 or the decorative layer 5.

  In the decorative sheet of the present invention, the glass transition temperature (Tg) of the heat-fusible layer 2 needs to be in the range of 65 to 85 ° C. As described above, in the present invention, the glass transition temperature (Tg) of the thermal bonding layer 2 is in a specific range of 65 to 85 ° C., and the total thickness of the decorative sheet is in a specific range of 200 to 400 μm. Thus, in the decorative sheet of the present invention provided with the heat fusion layer 2 applied to the overlay method, in addition to high adhesion at the time of molding, it has high adhesion even when exposed to high temperatures after molding. .

  From the viewpoint of further improving the adhesion at the time of molding and at high temperatures, the glass transition temperature (Tg) of the heat-fusible layer 2 is preferably about 65 to 80 ° C. In the present invention, the glass transition temperature (Tg) of the thermal bonding layer 2 means an endothermic peak temperature measured using a differential scanning calorimetry (DSC) method.

  The resin for forming the heat fusion layer 2 is not particularly limited as long as it has the above glass transition temperature (Tg), and, for example, a thermoplastic resin is used. Examples of the thermoplastic resin include acrylic resin, acrylic-modified polyolefin resin, chlorinated polyolefin resin, vinyl chloride-vinyl acetate copolymer, thermoplastic urethane resin, thermoplastic polyester resin, polyamide resin, and rubber-based resin. . A thermoplastic resin may be used individually by 1 type, and may be used in combination of 2 or more types.

  Although the thickness in particular of the heat-fusion layer 2 is not restrict | limited, Preferably it is about 0.5-10 micrometers, Preferably it is about 1-8 micrometers, More preferably, about 2-6 micrometers is mentioned.

[Surface protective layer 3]
For the purpose of enhancing the scratch resistance, weather resistance, etc. of the decorative resin molded product, the surface protective layer 3 is positioned on the outermost surface of the decorative resin molded product as necessary. It is a layer to be provided. Although the raw material which forms the surface protective layer 3 is not specifically limited, Usually, resin is used, Preferably a thermoplastic resin, ionizing radiation curable resin, etc. are used. Moreover, it is also preferable to form the surface protective layer 3 with a resin film. The resin film is not particularly limited, and examples thereof include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and thermoplastic resin films such as acrylic resins. Among these, acrylic resin films are particularly preferable. The surface protective layer 3 may be formed of one layer of, for example, an ionizing radiation curable resin or a thermoplastic resin film, or may be formed of two or more layers thereof. Hereinafter, the ionizing radiation curable resin used for forming the surface protective layer 3 will be described in detail.

(Ionizing radiation curable resin)
The ionizing radiation curable resin used for the formation of the surface protective layer 3 is a resin that crosslinks and cures when irradiated with ionizing radiation, and specifically, a polymerizable unsaturated bond or an epoxy group in the molecule. And a mixture of at least one of prepolymers, oligomers, monomers, and the like, as appropriate. Here, ionizing radiation means an electromagnetic wave or charged particle beam having an energy quantum capable of polymerizing or cross-linking molecules, and usually ultraviolet (UV) or electron beam (EB) is used. It also includes electromagnetic waves such as rays and γ rays, and charged particle rays such as α rays and ion rays. Among the ionizing radiation curable resins, the electron beam curable resin can be made solvent-free, does not require an initiator for photopolymerization, and provides stable curing characteristics, and thus is suitable for forming the surface protective layer 3. Used for.

  As the monomer used as the ionizing radiation curable resin, a (meth) acrylate monomer having a radically polymerizable unsaturated group in the molecule is suitable, and a polyfunctional (meth) acrylate monomer is particularly preferable. The polyfunctional (meth) acrylate monomer may be a (meth) acrylate monomer having two or more polymerizable unsaturated bonds (bifunctional or more), preferably three or more (trifunctional or more) in the molecule. Specific examples of the polyfunctional (meth) acrylate include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6-hexanediol di ( (Meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di ( (Meth) acrylate, ethylene oxide-modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Ethylene oxide modified trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri ( (Meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol Examples include hexa (meth) acrylate. These monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

  The oligomer used as the ionizing radiation curable resin is preferably a (meth) acrylate oligomer having a radical polymerizable unsaturated group in the molecule, and more than two polymerizable unsaturated bonds in the molecule. A polyfunctional (meth) acrylate oligomer having (bifunctional or higher) is preferred. Examples of the polyfunctional (meth) acrylate oligomer include polycarbonate (meth) acrylate, acrylic silicone (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, and polyether (meth) acrylate. , Polybutadiene (meth) acrylate, silicone (meth) acrylate, oligomer having a cationic polymerizable functional group in the molecule (for example, novolac type epoxy resin, bisphenol type epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc.) . Here, the polycarbonate (meth) acrylate is not particularly limited as long as it has a carbonate bond in the polymer main chain and a (meth) acrylate group in the terminal or side chain. It can be obtained by esterification with acrylic acid. The polycarbonate (meth) acrylate may be, for example, urethane (meth) acrylate having a polycarbonate skeleton. The urethane (meth) acrylate having a polycarbonate skeleton can be obtained, for example, by reacting a polycarbonate polyol, a polyvalent isocyanate compound, and hydroxy (meth) acrylate. The acrylic silicone (meth) acrylate can be obtained by radical copolymerizing a silicone macromonomer with a (meth) acrylate monomer. Urethane (meth) acrylate can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol and a polyisocyanate compound with (meth) acrylic acid. Epoxy (meth) acrylate can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. Also, a carboxyl-modified epoxy (meth) acrylate obtained by partially modifying this epoxy (meth) acrylate with a dibasic carboxylic acid anhydride can be used. Polyester (meth) acrylate is obtained by esterifying the hydroxyl group of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, for example, or It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide with (meth) acrylic acid. The polyether (meth) acrylate can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid. Polybutadiene (meth) acrylate can be obtained by adding (meth) acrylic acid to the side chain of the polybutadiene oligomer. Silicone (meth) acrylate can be obtained by adding (meth) (meth) acrylic acid to the terminal or side chain of silicone having a polysiloxane bond in the main chain. Among these, as the polyfunctional (meth) acrylate oligomer, polycarbonate (meth) acrylate, urethane (meth) acrylate, and the like are particularly preferable. These oligomers may be used individually by 1 type, and may be used in combination of 2 or more type.

  Among the ionizing radiation curable resins described above, polycarbonate (meth) acrylate is preferably used from the viewpoint of obtaining excellent three-dimensional formability. Moreover, it is more preferable to use combining a polycarbonate (meth) acrylate and urethane (meth) acrylate from a viewpoint which makes three-dimensional moldability and scratch resistance compatible.

(Other additive ingredients)
Various additives can be blended in the ionizing radiation curable resin composition forming the surface protective layer 3 according to desired physical properties to be provided in the surface protective layer 3. Examples of the additive include a weather resistance improver such as an ultraviolet absorber and a light stabilizer, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, a leveling agent, Examples include a thixotropic agent, a coupling agent, a plasticizer, an antifoaming agent, a filler, a solvent, a colorant, and a matting agent. These additives can be appropriately selected from commonly used ones. Examples of the matting agent include silica particles and aluminum hydroxide particles. In addition, as the ultraviolet absorber or light stabilizer, a reactive ultraviolet absorber or light stabilizer having a polymerizable group such as a (meth) acryloyl group in the molecule can be used.

(Thickness of the surface protective layer 3)
The thickness of the surface protective layer 3 is not particularly limited, but when the surface protective layer 3 is formed using a curable resin such as an ionizing radiation curable resin, for example, 1 to 100 μm, preferably 1 to 50 μm, More preferably, 1-30 micrometers is mentioned. When the thickness within such a range is satisfied, sufficient physical properties as a surface protective layer such as scratch resistance and weather resistance can be obtained, and when the surface protective layer 3 is formed using an ionizing radiation curable resin, ionization is performed. Since it is possible to irradiate the radiation uniformly, it is possible to cure uniformly, which is economically advantageous. Furthermore, since the thickness after hardening of the surface protective layer 3 satisfies the above range, the three-dimensional formability of the decorative sheet is further improved, so that it has high followability to complicated three-dimensional shapes such as automobile interior use. Can be obtained. Thus, even if the decorative sheet of the present invention has a sufficiently high three-dimensional formability even when the thickness of the surface protective layer 3 is made larger than that of the conventional one, a particularly high film thickness is formed on the surface protective layer 3. It is also useful as a decorative member for required members such as vehicle exterior parts. In addition, said thickness shows the thickness of the surface protective layer 3 after hardening. Moreover, when forming the surface protective layer 3 using a resin film, about 10-200 micrometers is mentioned preferably, for example.

(Formation of surface protective layer 3 when using ionizing radiation curable resin)
The surface protective layer 3 is formed, for example, by preparing an ionizing radiation curable resin composition containing an ionizing radiation curable resin, applying it, and curing the composition. The viscosity of the ionizing radiation curable resin composition is such that an uncured resin layer is formed on the surface of the base material layer 1, the decorative layer 5, the primer layer 4 and the like located under the surface protective layer 3 by a coating method described later. Any viscosity can be used.

  In the present invention, the prepared coating liquid is applied to the gravure coat, the bar coat on the base material layer 1, the decoration layer 5, the primer layer 4 and the like positioned below the surface protective layer 3 so as to have the thickness described above. , Roll coating, reverse roll coating, comma coating and the like, preferably gravure coating, to form an uncured resin layer.

  The uncured resin layer thus formed is irradiated with ionizing radiation such as electron beams and ultraviolet rays to cure the uncured resin layer, thereby forming the surface protective layer 3. Here, when an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected according to the resin to be used and the thickness of the layer, but usually includes an acceleration voltage of about 70 to 300 kV.

  In the electron beam irradiation, the transmission capability increases as the acceleration voltage increases. Therefore, when a resin that is easily deteriorated by electron beam irradiation is used under the surface protective layer 3, the electron beam transmission depth and the surface protection are used. The acceleration voltage is selected so that the thicknesses of the layers 3 are substantially equal. Thereby, the irradiation of the extra electron beam to the layer located under the surface protective layer 3 can be suppressed, and the deterioration of each layer due to the extra electron beam can be minimized.

  The irradiation dose is preferably such that the crosslinking density of the surface protective layer 3 is saturated, and is usually selected in the range of 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 50 kGy (1 to 5 Mrad).

  Furthermore, the electron beam source is not particularly limited. For example, various electron beam accelerators such as a Cockloft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type can be used. Can be used.

  When ultraviolet rays are used as the ionizing radiation, light rays including ultraviolet rays having a wavelength of 190 to 380 nm may be emitted. Although it does not restrict | limit especially as an ultraviolet source, For example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, an ultraviolet light emitting diode (LED-UV) etc. are mentioned.

  By adding various additives to the surface protective layer 3 thus formed, a hard coat function, an antifogging coat function, an antifouling coating function, an antiglare coating function, an antireflection coating function, an ultraviolet shielding coating function, You may perform the process which provides functions, such as an infrared shielding coat function.

  In addition, what is necessary is just to laminate | stack a resin film on the base material layer 1, the decoration layer 5, the primer layer 4, etc. which are located under the surface protective layer 3, when forming the surface protective layer 3 with a resin film. In addition, as a resin film, the resin film containing additives, such as a mat agent, and the resin film which surface-treated, such as sandblasting, can also be used.

[Primer layer 4]
The primer layer 4 is a layer that is included as necessary for the purpose of improving the adhesion between the surface protective layer 3 and the layer located therebelow. The primer layer 4 can be formed of a resin.

  Although it does not restrict | limit especially as resin which forms the primer layer 4, For example, a urethane resin, an acrylic resin, (meth) acryl-urethane copolymer resin, a polyester resin, a butyral resin etc. are mentioned. Among these resins, a urethane resin, an acrylic resin, and a (meth) acryl-urethane copolymer resin are preferable. These resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the urethane resin, polyurethane having a polyol (polyhydric alcohol) as a main ingredient and an isocyanate as a crosslinking agent (curing agent) can be used. The polyol may be any compound having two or more hydroxyl groups in the molecule, and specific examples include polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, polyether polyol and the like. Specific examples of the isocyanate include polyvalent isocyanate having two or more isocyanate groups in the molecule; aromatic isocyanate such as 4,4-diphenylmethane diisocyanate; hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, Examples include aliphatic (or alicyclic) isocyanates such as hydrogenated diphenylmethane diisocyanate.

  Among the urethane resins, from the viewpoint of improving the adhesion after crosslinking, preferably a combination of acrylic polyol or polyester polyol as a polyol and hexamethylene diisocyanate or 4,4-diphenylmethane diisocyanate as a crosslinking material; Includes a combination of acrylic polyol and hexamethylene diisocyanate.

  Although it does not restrict | limit especially as said acrylic resin, For example, the homopolymer of (meth) acrylic acid ester, the copolymer of 2 or more types of different (meth) acrylic acid ester monomers, or (meth) acrylic acid ester and others And a copolymer with the above monomer. More specifically, as a (meth) acrylic resin, poly (meth) acrylate methyl, poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, (meth) acrylic acid Methyl- (meth) butyl acrylate copolymer, (meth) ethyl acrylate- (meth) butyl acrylate copolymer, ethylene- (meth) methyl acrylate copolymer, styrene-methyl (meth) acrylate copolymer Examples include (meth) acrylic acid esters such as polymers. These acrylic resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  Although it does not restrict | limit especially as (meth) acryl-urethane copolymer resin, For example, acrylic-urethane (polyester urethane) block copolymer resin is mentioned. Further, as the curing agent, the above-described various isocyanates are used. The ratio of the acrylic to urethane ratio in the acrylic-urethane (polyester urethane) block copolymer resin is not particularly limited. For example, the acrylic / urethane ratio (mass ratio) is 9/1 to 1/9, preferably 8 / 2 to 2/8.

  Although it does not restrict | limit especially about the thickness of the primer layer 4, For example, about 0.5-20 micrometers, Preferably about 1-5 micrometers is mentioned. When the primer layer 4 satisfies such a thickness, the weather resistance of the decorative sheet can be further increased, and cracking, breakage, whitening, and the like of the surface protective layer 3 can be effectively suppressed.

  The primer layer 4 is a resin that forms the primer layer 4, gravure coat, gravure reverse coat, gravure offset coat, spinner coat, roll coat, reverse roll coat, kiss coat, wheeler coat, dip coat, solid coat by silk screen, It is formed by a normal coating method such as wire bar coating, flow coating, comma coating, flow coating, brush coating, spray coating, or the like, or transfer coating. Here, the transfer coating method is a method in which a primer layer or an adhesive layer is formed on a thin sheet (film substrate) and then the surface of the target layer in the decorative sheet is coated.

[Decoration layer 5]
The decorative layer 5 is a layer provided as necessary for the purpose of imparting decorative properties to the resin molded product. The decoration layer 5 may form a pattern, may be solid, or a combination thereof. The decoration layer 5 is formed, for example, by printing various patterns using ink and a printing machine. The pattern formed by the decorative layer 5 is not particularly limited, and for example, a grain pattern simulating the surface of a rock such as a grain pattern, a marble pattern (for example, a travertine marble pattern), a cloth simulating a texture or a cloth pattern Patterns, tiled patterns, brickwork patterns, etc., and patterns such as marquetry and patchwork that combine these are also included. These patterns can be formed by multicolor printing with normal yellow, red, blue and black process colors, or by multicolor printing with special colors prepared by preparing individual color plates constituting the pattern. It is formed.

  As the ink used for the decorative layer 5, an ink obtained by appropriately mixing a binder, a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, or a curing agent is used. The binder is not particularly limited, and examples thereof include polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, chlorinated polypropylene resins, acrylic resins, Examples thereof include polyester resins, polyamide resins, butyral resins, polystyrene resins, nitrocellulose resins, and cellulose acetate resins. These resins may be used alone or in combination of two or more.

  The colorant is not particularly limited. For example, carbon black (black), iron black, titanium white, antimony white, chrome yellow, titanium yellow, petal, cadmium red, ultramarine, cobalt blue, and other inorganic pigments, quinacridone red Organic pigments or dyes such as isoindolinone yellow and phthalocyanine blue, metallic pigments composed of scaly foils such as aluminum and brass, pearl luster composed of scaly foils such as titanium dioxide-coated mica and basic lead carbonate (pearl) ) Pigments.

  Although the thickness in particular of the decoration layer 5 is not restrict | limited, For example, about 1-40 micrometers, Preferably about 3-30 micrometers is mentioned.

  The decoration layer 5 may be a metal thin film layer. Examples of the metal forming the metal thin film layer include tin, indium, chromium, aluminum, nickel, copper, silver, gold, platinum, zinc, and alloys containing at least one of these. The method for forming the metal thin film layer is not particularly limited, and examples thereof include a vapor deposition method such as a vacuum vapor deposition method, a sputtering method, and an ion plating method using the above-described metal. Moreover, in order to improve adhesiveness with an adjacent layer, you may provide the primer layer using well-known resin in the surface and back surface of a metal thin film layer.

[Hidden layer 7]
The hiding layer 7 is a layer provided as necessary (not shown) for the purpose of suppressing color change and variation of the decorative sheet.

  The concealing layer 7 is usually provided as an opaque layer because it is provided to prevent the base material layer 1 from adversely affecting the color tone and design of the decorative sheet.

  The masking layer 7 is formed by using an ink composition in which a binder, a colorant such as a pigment and a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, and a curing agent are appropriately mixed. The ink composition for forming the hiding layer 7 is appropriately selected from those used for the decorative layer 5 described above.

  The concealing layer 7 is usually set to a thickness of about 1 to 10 μm and is desirably formed as a so-called solid printing layer.

2. Decorated resin molded product The decorated resin molded product of the present invention is formed by integrating the decorative sheet of the present invention and a molded resin. That is, the decorative resin molded product of the present invention comprises a laminate in which at least a molded resin layer, a heat fusion layer, and a base material layer are laminated in this order, and the thickness of the portion excluding the molded resin layer is It has a portion of 200 to 400 μm, and the glass transition temperature of the heat fusion layer is in the range of 65 to 85 ° C. In addition, in the case where the decorative sheet of the present invention and the molding resin are integrated and molded, the thickness of the portion where the decorative sheet is stretched is reduced, and therefore, in this portion, the thickness is 200 to 400 μm. May be thinner. In the decorative resin molded product of the present invention, if necessary, at least one layer such as the above-described surface protective layer 3, primer layer 4, and decorative layer 5 may be further provided on the decorative sheet. FIG. 3 is a schematic cross-sectional view of a decorative resin molded product obtained by integrating the decorative sheet having the laminated structure shown in FIG. 1 and a molding resin. FIG. 4 is a schematic cross-sectional view of a decorative resin molded product obtained by integrating a decorative sheet having a laminated structure shown in FIG. 2 and a molding resin.

  The decorative resin molded product of the present invention can be produced by an overlay method using the decorative sheet of the present invention having a heat-sealing layer. As described above, in the overlay method of the present invention, the decorative sheet having the heat-fusible layer is softened by heating, and the decorative sheet is formed by following the shape of the molded resin, while the heat-fusible layer is molded resin. To produce a decorative resin molded product in which the molding resin is decorated with a decorative sheet.

More specifically, the decorative resin molded product of the present invention is manufactured by an overlay method including the following steps 1 to 5.
Step 1: The decorative sheet and the molding resin are formed so that the thermal adhesive layer of the decorative sheet of the present invention faces the molding resin and the inside of the chamber is hermetically divided through the decorative sheet. In the chamber Step 2: The inside of the chamber is depressurized so that one side and the other side of the chamber divided through the decorative sheet have the same pressure, and the inside of the chamber Step of heating and softening the decorative sheet of Step 3: Step of releasing the reduced pressure on the side opposite to the molding resin in the chamber divided through the decorative sheet and softening by heating Step of forming the sheet following the shape of the molding resin Step 4: Step of heat-sealing the decorative sheet and the molding resin via the heat-bonding layer Step 5: Via the decoration sheet Divided The step of releasing the decompression on the molding resin side in the chamber and taking out the decorative resin molded product

  In the above-mentioned step 2, that one side and the other side in the chamber divided through the decorative sheet have the same pressure means that the decorative sheet is kept in a substantially horizontal state. This means that the pressure on both sides through the decorative sheet is close, and the pressure on both sides does not necessarily have to be completely the same. Also, when the decorative sheet is heated and softened, the decorative sheet may hang down due to its own weight, so the decorative sheet can be changed slightly by changing the degree of vacuum on both sides of the decorative sheet in the chamber. May be kept substantially horizontal. Moreover, the pressure reduction in the chamber in the step 2 and before and after heating of the decorative sheet are not particularly limited and may be performed simultaneously.

  In the above step 2, the heating temperature in the chamber is not particularly limited as long as the decorative sheet is softened in step 3 and can follow the shape of the molded resin layer, but is preferably about 90 to 200 ° C. More preferably, about 100-180 degreeC is mentioned.

  Further, in the step of causing the decorative sheet to follow the molding resin in Step 3, the decorative sheet may be formed by the residual heat of the heating in Step 2, but the inside of the chamber is continuously heated to continue heating the decorative sheet. It is preferable. The heating temperature in the chamber in step 3 is preferably about the same as the heating temperature in step 2 above.

  In the step of heat-sealing the decorative sheet and the molding resin through the heat-sealing layer in step 4, the heat-sealing layer may be performed by the residual heat of heating in step 2 or step 3, Is preferably heated to sufficiently soften the heat-fusible layer. The heating temperature in the chamber in step 4 is not particularly limited as long as the heat-fusible layer can be softened and the decorative sheet and the molded resin can be heat-sealed, but preferably about 110 to 220 ° C., more preferably Is about 130 to 200 ° C.

  The means for heating the decorative sheet in the chamber in Steps 2 to 4 is not particularly limited, and for example, heating with a hot plate heater, heating with high-temperature steam, or the like can be used. The heating means in Steps 2 to 4 may be the same or different, and the heating temperature may be changed for each step as necessary.

  In the decorative resin molded product of the present invention, the resin for the molded resin layer may be selected according to the application. The molding resin constituting the molding resin layer may be a thermoplastic resin or a thermosetting resin.

  Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene, ABS resins, styrene resins, polycarbonate resins, acrylic resins, and vinyl chloride resins. These thermoplastic resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  Moreover, as a thermosetting resin, a urethane resin, an epoxy resin, etc. are mentioned, for example. These thermosetting resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  Since the decorated resin molded product of the present invention can be manufactured by the overlay method, it becomes easy to deal with a variety of small lot production, and variations of the decorated resin molded product can be widely developed. Furthermore, the decorative resin molded product of the present invention has high adhesion even when exposed to high temperatures after molding, in addition to high adhesion during molding. Accordingly, the decorative resin molded product of the present invention includes, for example, interior materials or exterior materials for vehicles such as automobiles; fittings such as window frames and door frames; interior materials for buildings such as walls, floors, and ceilings; It can be used as a housing for home appliances such as air conditioners;

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

(Preparation of decorative sheet)
<Examples 1, 4 to 6 and Comparative Examples 1 to 4>
A decorative layer (thickness of 10 μm) is formed by gravure printing on an ABS resin film as a base material layer having the thickness described in Table 1 and Table 2, using an ink containing vinyl chloride-vinyl acetate-acrylic copolymer resin. ) Was formed. The decorative layer pattern was a wood grain pattern. Next, a heat-sealing layer (thickness: 5 μm) was formed on the surface of the ABS resin film opposite to the decorative layer by gravure printing using a resin having Tg described in Tables 1 and 2. Next, a primer layer (thickness: 2 μm) was formed on the decorative layer by gravure printing using a primer composition described later. Next, an ionizing radiation curable resin, which will be described later, was applied on the primer layer by gravure reverse coating so that the thickness after curing was 10 μm. Next, the coated ionizing radiation curable resin is irradiated with an electron beam (acceleration voltage 165 kV, irradiation dose 50 kGy (5 Mrad)) to cure the ionizing radiation curable resin to form a surface protective layer. A decorative sheet (laminated structure 1) was obtained in which a heat-sealing layer / base material layer / decoration layer / primer layer / surface protective layer was laminated in this order. The total thickness of each decorative sheet is as described in Table 1 and Table 2. In addition, the total thickness of each decorative sheet is a value measured using a thickness meter (Digimicro MF-501 manufactured by Nikon Corporation).
[Electron beam curable resin composition]
Acrylic silicone acrylate (weight average molecular weight 20,000): 70 parts by mass Hexafunctional urethane acrylate oligomer (weight average molecular weight 5,000): 30 parts by mass

<Example 2>
A decorative layer (thickness 10 μm) was formed by gravure printing on an ABS resin film as a base material layer having the thickness shown in Table 1, using an ink containing vinyl chloride-vinyl acetate-acrylic copolymer resin. . The decorative layer pattern was a wood grain pattern. Next, a heat fusion layer (thickness 5 μm) was formed by gravure printing on the surface of the ABS resin film opposite to the decorative layer, using a resin having Tg shown in Table 1. Next, a decorative sheet (laminated structure 2) in which an acrylic film (thickness: 100 μm) is laminated on the decorative layer by thermal lamination, and the heat-fusible layer / base material layer / decorative layer / surface protective layer is laminated in this order. )

<Example 3>
A decorative layer (thickness) is obtained by gravure printing on an acrylic film as a base material layer (surface protective layer) having the thickness shown in Table 1 using an ink containing vinyl chloride-vinyl acetate-acrylic copolymer resin. 10 μm). The decorative layer pattern was a wood grain pattern. Next, a heat-sealing layer (thickness 5 μm) is formed on the decoration layer by gravure printing using a resin having Tg shown in Table 1, and the heat-fusion layer / decoration layer / base material layer (surface) A decorative sheet (laminate structure 3) in which the protective layer was laminated in this order was obtained.

(Evaluation of adhesion during molding)
Using the decorative sheets of Examples 1 to 6 and Comparative Examples 1 to 4, a decorative resin molded product was produced by the following steps, and the surface of the obtained decorative resin molded product was observed visually, and the following: The adhesiveness at the time of molding was evaluated according to the criteria. The results are shown in Tables 1 and 2.

[Production of decorative resin molded products]
1. A decorative sheet is placed on the upper side of the chamber and a molding resin is placed on the lower side so as to face each other. At this time, the inside of the chamber is divided in an airtight manner through the decorative sheet.
2. While the decorative sheet is heated by the hot platen heater, the inside of the chamber is evacuated so that the upper and lower sides of the decorative sheet have the same vacuum pressure.
3. When the decorative sheet temperature reaches 150 ° C., the upper side of the chamber is opened to the atmosphere, and the softened decorative sheet is made to follow the shape of the molded resin.
4). The heating temperature is raised, and when the decorative sheet temperature reaches 170 ° C., the heating temperature is maintained for 20 seconds, and heat fusion is performed at the interface between the decorative sheet and the molding resin.
5. The lower side of the chamber is opened to the atmosphere, and the decorative resin molded product is taken out.

[Evaluation of adhesion during molding]
○: The decorative sheet is not peeled over the entire surface of the decorative resin molded product.
X: The decorative sheet peeled off at the end of the decorative resin molded product.
-: The decorative sheet breaks due to heat during molding, and a decorative resin molded product cannot be manufactured.

(Evaluation of adhesion at high temperatures)
After the decorative resin molded product obtained above was allowed to stand at 110 ° C. for 168 hours, the surface was visually observed to confirm the presence or absence of peeling, and the adhesion at high temperatures was evaluated according to the following criteria. The results are shown in Tables 1 and 2.
○: The decorative sheet is not peeled over the entire surface of the decorative resin molded product.
X: The decorative sheet peeled off at the end of the decorative resin molded product.
-: The decorative sheet breaks due to heat during molding, and a decorative resin molded product cannot be manufactured.

  As is clear from the results shown in Table 1 and Table 2, the total thickness of the decorative sheet is in the range of 200 to 400 μm, and the glass transition temperature of the heat-fusible layer is in the range of 65 to 85 ° C. In the decorative sheets 1-6, in addition to the high adhesiveness at the time of shaping | molding, it had high adhesiveness also when exposed to high temperature after shaping | molding.

  On the other hand, although the total thickness of the decorative sheet is in the range of 200 to 400 μm, the decorative sheet of Comparative Example 1 having a high glass transition temperature of 90 ° C. is exposed to a high temperature during and after molding. The adhesiveness was poor. Further, the decorative sheet of Comparative Example 2 having a low glass transition temperature of 60 ° C. of the heat-fusible layer was inferior in adhesion when exposed to a high temperature after molding.

  Further, although the glass transition temperature of the heat-sealing layer is in the range of 65 to 85 ° C., the decorative sheet of Comparative Example 3 having a thick total thickness of 450 μm is exposed to a high temperature during and after molding. The adhesiveness was poor. On the other hand, in the decorative sheet of Comparative Example 4 where the total thickness of the decorative sheet was 175 μm, the decorative sheet was broken by heat during molding, and a decorative resin molded product could not be produced.

DESCRIPTION OF SYMBOLS 1 ... Base material layer 2 ... Heat-fusion layer 3 ... Surface protective layer 4 ... Primer layer 5 ... Decoration layer 6 ... Molding resin layer

Claims (8)

The decorative sheet having the heat-fusible layer is softened by heating, and the decorative sheet is formed by following the shape of the molded resin, and the heat-fused layer is heat-fused to the molded resin to form the decorative sheet. A decorative sheet used in an overlay method for producing a decorative resin molded product in which the molding resin is decorated with a decorative sheet,
The decorative sheet is composed of a laminate in which at least a base material layer and a heat sealing layer are laminated,
The laminate has a thickness in the range of 215 to 400 μm,
The decorating sheet whose glass transition temperature of the said heat-fusion layer exists in the range of 65-85 degreeC.   The decorative sheet according to claim 1, further comprising a surface protective layer.   The decorative sheet according to claim 1 or 2, further comprising a decorative layer.   The decorative sheet according to any one of claims 1 to 3, comprising a laminate in which the heat-fusible layer, the base material layer, and a surface protective layer are laminated in this order.   The decorative sheet according to claim 4, comprising a laminate in which at least one of a primer layer and a decorative layer is laminated between the base material layer and the surface protective layer.   The decorative sheet according to claim 1, comprising a laminate in which the heat-sealing layer, a decorative layer, and the base material layer are laminated in this order.   A decorative resin molded product in which the heat-sealing layer of the decorative sheet according to claim 1 is laminated on a molded resin layer. The manufacturing method of a decorative resin molded product provided with the following processes 1-5.
Step 1: The thermal adhesive layer of the decorative sheet according to any one of claims 1 to 6 is made to face the molding resin, and the inside of the chamber is hermetically divided through the decorative sheet, The process of arrange | positioning the said decorating sheet and the said molding resin in a chamber Process 2: Inside the said chamber so that the one side and the other side in the said chamber divided | segmented via the said decorating sheet may become the same pressure Step of depressurizing and heating and softening the decorative sheet in the chamber Step 3: Release the pressure on the opposite side of the molding resin in the chamber divided through the decorative sheet The step of molding the decorative sheet softened by heating to follow the shape of the molding resin Step 4: The step of heat-sealing the decorative sheet and the molding resin through the heat-sealing layer Step 5 : The decoration The step of releasing the pressure reduction on the side of the molding resin in the chamber divided through the seat and taking out the decorative resin molded product