Decorative film and decorative molded body

Abstract

The objective of this invention is to provide a decorative film that exhibits excellent adhesion to substrates containing polypropylene resin and excellent resistance to sticking in molds. This invention relates to a decorative film comprising a substrate having a decorative layer, an adhesive layer, and a polypropylene layer, for decorating substrates containing polypropylene resin. Furthermore, this invention relates to a decorative molded article formed by bonding the decorative film to a substrate containing polypropylene resin.

Description

Technical Field

[0001] This invention relates to decorative films and decorative molded articles. Background Technology

[0002] Previously, when protecting or decorating (adding decoration) the surfaces of automotive interior and exterior parts, home appliance parts, and building material parts, the following process was performed: after processing the molded body through injection molding or vacuum forming, a coating was applied to the surface of the molded body through spray coating or other methods, followed by drying / heat curing. However, in addition to the problem of volatile organic solvent emissions deteriorating the working environment, such coating also suffers from poor paint yield and low productivity because each molded part requires processing steps and production equipment, and repeated coating is necessary.

[0003] In recent years, the use of resin molded bodies has developed to achieve lightweighting of automotive interior and exterior parts, home appliance parts, and building material parts. For decorative (decorative) resin molded bodies, spray painting is often unsuitable, leading to the development of various methods for adding decoration to their surfaces. Among these methods, decorating the outermost surface of the molded body with a decorative film offers advantages over coating or printing methods, such as higher design freedom and superior productivity. Furthermore, the decorative film method can also decorate three-dimensional, textured surfaces of molded bodies, thus finding applications across a wide range of uses.

[0004] For example, Patent Document 1 discloses a decorative molding laminate having a substrate layer and an adhesive layer, wherein the adhesive layer comprises an organosilicon adhesive layer and an acrylic adhesive layer. Furthermore, Patent Document 2 discloses a vacuum-formed sheet having an adhesive layer on the lower surface of a surface film. Here, the adhesive layer uses a substance obtained by mixing 1.5 to 2.5 equivalents of polyisocyanate into a thermoplastic saturated copolyester resin and then curing it.

[0005] Patent document 3 discloses a decorative film used in an injection molding and simultaneous transfer decoration method. Here, a three-dimensional decorative film for injection molding and simultaneous transfer is disclosed, formed by sequentially stacking a release layer, a protective layer, a coloring layer, and an adhesive layer on a substrate. Examples of resins used as the adhesive layer include acrylic resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, styrene-acrylic copolymer resins, polyester resins, and polyamide resins.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-154410

[0009] Patent Document 2: Japanese Patent Application Publication No. 2010-120209

[0010] Patent Document 3: Japanese Patent Application Publication No. 2011-88420 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] In decorative molding, it is essential that the adhered object and the decorative film adhere tightly and not easily peel off. However, when the adhered object is made of polypropylene resin, using conventional decorative molding adhesive sheets (decorative films) can result in insufficient adhesion of the decorative film to the adhered object.

[0013] Furthermore, in the manufacture of decorative molded articles, methods such as film embedding molding or in-mold molding are sometimes used to bond the decorative film to the substrate. In this case, the decorative film is sometimes molded into the desired shape before the molten resin constituting the substrate is injected. However, in such a process, it is sometimes difficult to pre-process the decorative film into the desired shape without peeling it off from the mold. Thus, if problems occur in the pre-processing stage of the decorative film, the production efficiency of the decorative molded article can be significantly reduced, and unexpected defects may arise in the decorative film itself, becoming a problem.

[0014] Therefore, in order to solve the problems of the prior art, the inventors have conducted research to provide a decorative film that exhibits excellent adhesion to substrates containing polypropylene resin and excellent resistance to sticking in molds.

[0015] Methods for solving problems

[0016] In order to solve the above-mentioned problems, in-depth research was conducted. As a result, the inventors discovered that by sequentially stacking a substrate having a decorative layer, an adhesive layer and a polypropylene layer in a decorative film, a decorative film that exhibits excellent adhesion to the substrate containing polypropylene resin and excellent resistance to sticking to the mold can be obtained.

[0017] Specifically, the present invention has the following structure.

[0018] [1] A decorative film comprising, in sequence, a substrate having a decorative layer, an adhesive layer, and a polypropylene layer.

[0019] It is used to decorate substrates containing polypropylene resin.

[0020] [2] According to the decorative film described in [1], the adhesive layer contains:

[0021] Block copolymers comprising blocks made of isopentane-derived structures and blocks made of styrene-based polymers; and

[0022] Terpenoid resins.

[0023] [3] According to the decorative film described in [2], the terpene resin is selected from at least one of terpene resin, aromatic modified terpene resin, and terpene phenol resin.

[0024] The softening point of terpene resins is 60–130℃.

[0025] The number average molecular weight of terpene resins ranges from 300 to 1500.

[0026] [4] According to the decorative film described in [2] or [3], the content of terpene resin is 40 to 200 parts by weight relative to 100 parts by weight of block copolymer.

[0027] [5] The thickness of the adhesive layer of the decorative film according to any one of [1] to [4] is 0.5 to 20 μm.

[0028] [6] The decorative film according to any one of [1] to [5] has a polypropylene layer thickness of 1 to 30 μm.

[0029] [7] The decorative film according to any one of [1] to [6] is used for decorating an object by means of film embedding or in-mold molding.

[0030] [8] A decorative molded body is formed by bonding the decorative film described in any one of [1] to [7] to an adhesive containing polypropylene resin.

[0031] [9] The decorative molded body according to [8] is used in automotive components, electronic equipment or building materials.

[0032] The effects of the invention

[0033] According to the present invention, a decorative film that exhibits excellent adhesion to substrates containing polypropylene resin and excellent resistance to sticking to molds can be obtained. Attached Figure Description

[0034] Figure 1 A cross-sectional view showing an example of the composition of a decorative film.

[0035] Figure 2 A cross-sectional view showing an example of the composition of a decorative molded body. Detailed Implementation

[0036] The present invention will now be described in detail. The description of the constituent elements described below is sometimes based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. Furthermore, the numerical range indicated by “~” in this specification refers to the range including the values ​​described before and after “~” as both the lower and upper limits.

[0037] (Decorative film)

[0038] This invention relates to a decorative film comprising a substrate having a decorative layer, an adhesive layer, and a polypropylene layer in sequence. The decorative film of this invention is used to decorate an adherend containing polypropylene resin. Due to the above-described structure, the decorative film of this invention exhibits excellent adhesion to adherends containing polypropylene resin. Therefore, the decorative film of this invention is preferably used for bonding adherends containing polypropylene resin as a main component. Furthermore, due to the above-described structure, the decorative film of this invention exhibits excellent resistance to adhesion to molds. That is, the decorative film of this invention has excellent peelability from the mold. Therefore, when the decorative film is molded, it can be easily peeled off from the mold and can be smoothly moved to the subsequent bonding process with the adherend. Furthermore, by easily peeling the decorative film from the mold, defects in the decorative film can be suppressed, thus preserving the design of the decorative molded article.

[0039] Previously, polycarbonate resins and ABS resins were used as the substrates for decorative molded bodies. Therefore, the specific structure of decorative films used to decorate substrates containing polypropylene resin as the main component has not been sufficiently studied. Furthermore, when manufacturing decorative molded bodies to decorate substrates, film embedding molding or in-mold molding methods are sometimes used, but the processability and processing efficiency of the decorative film in these cases remain issues. Therefore, the inventors have conducted fundamental investigations and studies on the layer structure of decorative films, thereby producing a decorative film in which a polypropylene layer is laminated as the outermost layer, and which sequentially comprises a substrate having a decorative layer, an adhesive layer, and a polypropylene layer. As a result, a decorative film that exhibits excellent adhesion to substrates containing polypropylene resin as the main component is successfully obtained, and the decorative film can be easily peeled off from the processing mold during mold processing.

[0040] Figure 1 A cross-sectional view illustrating an example of the structure of the decorative film of the present invention. For example... Figure 1 As shown, the decorative film 30 sequentially comprises a substrate 10 having a decorative layer, an adhesive layer 12, and a polypropylene layer 14. In the decorative film 30, other layers can be disposed between the layers, but in this embodiment, it is preferable that the substrate 10 having the decorative layer and the adhesive layer 12 are laminated in direct contact, and that the adhesive layer 12 and the polypropylene layer 14 are also laminated in direct contact. It is particularly preferable that the adhesive layer 12 and the polypropylene layer 14 are laminated in direct contact. Figure 1 As shown, by providing a polypropylene layer 14 as the outermost layer of the decorative film 30, the decorative film 30 can exhibit excellent adhesion to substrates containing polypropylene resin as the main component. Furthermore, the decorative film 30 possesses… Figure 1 As shown in the diagram, this structure provides excellent resistance to sticking to the mold.

[0041] exist Figure 1 For convenience, the substrate 10 with the decorative layer is depicted as a single layer. However, the substrate 10 with the decorative layer can be a single layer consisting of the decorative layer, or it can have a multi-layer structure comprising at least a substrate and a decorative layer. Preferably, the substrate 10 with the decorative layer comprises a multi-layer structure comprising a substrate and a decorative layer. In the case where the substrate 10 with the decorative layer comprises a substrate and a decorative layer, the decorative layer in the substrate 10 with the decorative layer can be disposed in contact with the adhesive layer 12. In this case, the substrate in the substrate 10 with the decorative layer is disposed on the outermost layer of the decorative film. Furthermore, an easy-to-adhere layer or similar layer that improves adhesion can be provided between the decorative layer and the adhesive layer 12.

[0042] Furthermore, when the decorative film of the present invention is used for film embedding molding, functional layers such as a hard coating layer and an anti-reflective layer, which are different from the decorative layer, can be provided on the outermost layer (the opposite side in contact with the adhesive layer 12) of the substrate 10 having the decorative layer.

[0043] On the other hand, when the decorative film of the present invention is used for in-mold molding, it is preferable that the decorative layer of the substrate 10 having the decorative layer must be provided on the surface in contact with the adhesive layer 12, a substrate with demolding properties that allows the substrate and the decorative layer to be easily separated after molding is used, or a demolding layer is provided between the substrate and the decorative layer, so that the substrate (demolding layer) and the decorative layer are formed in contact.

[0044] The decorative film of the present invention is preferably used for decorating adhered objects using a film embedding molding method or an in-mold molding method. In the film embedding molding method and the in-mold molding method, after the decorative film is pre-processed into a 3D shape, it is placed in the mold cavity of a mold, and molten resin constituting the adhered object is injected into the mold to obtain a decorative molded body in which the decorative film and the adhered object are integrated.

[0045] (Adhesive layer)

[0046] The decorative film has an adhesive layer. In this invention, a substrate with a decorative layer and a polypropylene layer are respectively laminated on both sides of the adhesive layer, and the adhesive layer is not exposed in the decorative film.

[0047] In this embodiment, the adhesive layer preferably comprises a block copolymer and a terpene resin. Here, the block copolymer comprises blocks made from a structure derived from isopentane and blocks made from a styrene-based polymer. The content of the terpene resin relative to 100 parts by weight of the block copolymer is preferably 40 parts by weight or more, more preferably 45 parts by weight or more, further preferably 50 parts by weight or more, and particularly preferably 55 parts by weight or more. Furthermore, the content of the terpene resin relative to 100 parts by weight of the block copolymer is preferably 200 parts by weight or less, more preferably 180 parts by weight or less, further preferably 160 parts by weight or less, even more preferably 140 parts by weight or less, and particularly preferably 120 parts by weight or less. This is preferred. By keeping the content of the terpene resin within the above range, the interlayer adhesion between the adhesive layer and the polypropylene layer can be improved, and further, the interlayer adhesion between the adhesive layer and the substrate having the decorative layer can also be improved. That is, by keeping the content of the terpene resin within the above range, the adhesion to the polypropylene layer can be effectively improved without compromising the adhesion resistance of the decorative film.

[0048] Furthermore, the total content of the block copolymer and terpene resin relative to the total mass of the adhesive layer is preferably 50% by mass or more, more preferably 60% by mass or more. Additionally, the total content of the block copolymer and terpene resin relative to the total mass of the adhesive layer can be 100% by mass. By setting the total content of the block copolymer and terpene resin within the above range, the adhesive layer can more effectively improve the interlayer strength between itself and the substrate with the decorative layer and the polypropylene layer. That is, by setting the content of the terpene resin within the above range, the adhesion to the polypropylene layer can be effectively improved without compromising the adhesion resistance of the decorative film.

[0049] The adhesive layer comprises block copolymers containing blocks made of isopentane-derived structures and blocks made of styrene-based polymers. In this specification, the isopentane-derived structure refers to the following structure. Furthermore, the blocks made of isopentane-derived structures are blocks polymerized from the isopentane-derived structures described above. Additionally, the isopentane-derived structure is preferably a propylene / ethylene copolymer.

[0050]

[0051] Blocks made of styrene-based polymers are preferably made of styrene polymers or α-methylstyrene polymers.

[0052] In addition to blocks made from isopentane and styrene-based polymers, the adhesive layer may also contain blocks made from other polymers. Examples of blocks made from other polymers include blocks made from ethylene and blocks made from (meth)acrylate polymers.

[0053] In the block copolymers included in the adhesive layer, if block A is made of isopentane and block B is made of styrene-based polymers, the block copolymer can be a diblock copolymer with an AB structure, or a triblock copolymer with an ABA structure or a BAB structure. Furthermore, it can also be a block copolymer with repeating structures of each block, such as the -ABAB- structure. Further, as described above, it can be a block copolymer that further includes blocks made of other polymers.

[0054] The block copolymer contained in the adhesive layer may further have substituents in its polymer chain; for example, a block copolymer containing substituents with unsaturated bonds may be used.

[0055] The aforementioned block copolymers can be produced by polymerization using known methods, but commercially available products can also be used. Examples of commercially available products include Septon 1020, Septon 2002, Septon 4033, and Septon HG252 manufactured by Clare.

[0056] The terpene resin contained in the adhesive layer is preferably selected from at least one of terpene resins, aromatic modified terpene resins, and terpene phenol resins. More specifically, examples include α-pinene polymers, β-pinene polymers, dipentene polymers, and terpene resins that have been modified with phenol, aromatics, hydrogenation, or hydrocarbons.

[0057] The softening point of the terpene resin is preferably 60°C or higher, more preferably 65°C or higher, even more preferably 70°C or higher, and particularly preferably 75°C or higher. The softening point of the terpene resin can be 100°C or higher. Furthermore, the softening point of the terpene resin is preferably 130°C or lower, more preferably 125°C or lower. Additionally, the softening point of the terpene resin is the value measured using an automatic softening point measuring device (FLEX SCIENTIFIC, EX-719PD4) according to the method described in JIS K2207.

[0058] The number average molecular weight of the terpene resin is preferably 300 or more, more preferably 350 or more, and even more preferably 400 or more. Furthermore, the number average molecular weight of the terpene resin is preferably 1500 or less, more preferably 1400 or less, and even more preferably 1300 or less. The number average molecular weight of the terpene resin is determined by gel permeation chromatography (GPC) using a standard curve prepared using standard polystyrene with a known molecular weight.

[0059] As the terpene resin, commercially available products can be used. As commercially available products, for example, YSレジンPX 1150, YSレジンPX 1250, YSレジンTO 125, and YSレジンTO manufactured by Toshiro Co., Ltd. 105, YSポリスターT 125, YSポリスターT 80, YSポリスターG 125, etc.

[0060] In addition to the block copolymers and resins mentioned above, the adhesive layer may also contain additives. Examples of additives include antioxidants (or anti-aging agents), silane coupling agents, tackifiers other than terpene resins, oil components, softeners, crosslinking agents, pigments, and hydrogen-abstracting initiators.

[0061] Examples of antioxidants include phenolic antioxidants, amine antioxidants, lactone antioxidants, phosphorus antioxidants, and sulfur antioxidants. These antioxidants can be used individually or in combination of two or more.

[0062] Examples of silane coupling agents include, for example, thiol-based silane coupling agents containing thiol groups, epoxy-based silane coupling agents having epoxy groups, and vinyl-based silane coupling agents having vinyl groups. Among these, thiol-based silane coupling agents are preferred for use in the present invention. Examples of thiol-based silane coupling agents include mercaptotrimethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, triethoxy(2-mercaptoethyl)silane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 4-mercaptobutyltrimethoxysilane, 10-mercaptodecyltriethoxysilane, 11-mercaptoundecyltrimethoxysilane, and 11-mercaptoundecyltriethoxysilane.

[0063] Examples of tackifiers other than terpene resins include styrene resins, rosin resins, C5 resins, C9 resins, and petroleum-based resins such as C5 / C9 resins.

[0064] As an oil component, alkane-based or cycloalkane-based system oils are preferred. Considering reasons such as the reduced likelihood of rubber degradation, alkane-based system oils are more preferred.

[0065] Examples of hydrogen-abstracting initiators include methyl benzoylformate, tetramethylbenzophenone, and other benzophenone compounds.

[0066] The thickness of the adhesive layer is preferably 0.5 μm or more, more preferably 1 μm or more. Furthermore, the thickness of the adhesive layer is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. In this embodiment, the thickness of the adhesive layer can also be made thin.

[0067] (Substrate with decorative layer)

[0068] The decorative film contains a substrate with a decorative layer. Here, the substrate with the decorative layer preferably comprises a film-like substrate and a decorative layer.

[0069] The decorative layer constituting the substrate having the decorative layer can be a layer disposed on the outermost surface of the decorative film (the side opposite to the side in contact with the adhesive layer), or a layer disposed on the side in contact with the adhesive layer, but preferably a layer disposed on the side in contact with the adhesive layer. In particular, when the decorative film is used for in-mold molding, the decorative layer needs to be disposed on the side in contact with the adhesive layer. On the other hand, when the decorative film is used for film embedding molding, the decorative layer is preferably disposed on the outermost surface of the decorative film (the side opposite to the side in contact with the adhesive layer), in which case functional layers such as a hard coating layer or an anti-reflective layer can be further disposed on the outermost surface.

[0070] The decorative layer is preferably a printed layer. The printed layer is formed, for example, by printing on one side of the aforementioned film-like substrate using ink with thermosetting resin, UV-curable resin, or similar ink as the main agent. Printing can be performed using known printing methods such as inkjet printing or screen printing. Examples of film-like substrates for printing include, for example, ABS resin (a copolymer of acrylonitrile, butadiene, and styrene), AS resin (a copolymer of acrylonitrile and styrene), acrylic resins, polyethylene terephthalate, polybutylene terephthalate, nylon, polyacetal, polyphenylene ether, phenolic resin, urea resin, melamine resin, liquid crystal polymer, polytetrafluoroethylene, poly1,1-difluoroethylene, polysulfone, polyethersulfone, polyacetal, polyetheretherketone, polyphenylene sulfide, polyetherimide, polyamide imide, polycarbonate, polyolefin resins (polyethylene, polypropylene, etc.), polystyrene, and urethane resins. These substrates are preferably stretchable to follow the shape of the object being adhered during the molding process. In addition, while transparent films are typically used as substrates for film-like applications, colorants such as carbon (graphite) can be mixed in to create colored layers for design purposes.

[0071] To protect the printed layer, the substrate with the decorative layer may further have a surface protective layer and a printing protective layer. The surface protective layer is preferably disposed on the exposed outermost surface of the substrate with the decorative layer, and serves to improve scratch resistance and weather resistance. Therefore, the surface protective layer is preferably a layer comprising a curable resin layer, more preferably a hard coating layer. The curable resin is preferably a photocurable resin, more preferably an ultraviolet-curable resin. In this case, the resin composition used to form the surface protective layer preferably includes, for example, a photopolymerization initiator in addition to an ultraviolet-curable resin. Furthermore, when the decorative layer is formed by printing, it is easily scratched by the ink used; therefore, to prevent scratches, a printing protective layer such as a hard coating layer can be provided on the ink layer.

[0072] The surface protective layer may further contain microparticles. Examples of microparticles include inorganic microparticles, with metal oxides being a preferred example. Furthermore, pigments and dyes may be included as needed. Additionally, the surface protective layer may include additives such as pigment dispersants, defoamers, UV absorbers, HALS (hindered amine light stabilizers), antioxidants, antistatic agents, abrasion inhibitors, and anti-blocking agents, as required.

[0073] The substrate with the decorative layer may further include a protective film, and if the outermost layer has an adhesive layer, it may further include a release layer. The protective film and release layer are provided for temporary protection of the surface protective layer. For example, they may be provided to prevent scratches on the surface protective layer, printed layer, etc., before use. The protective film is preferably a self-adhesive film made of ethylene vinyl acetate copolymer, or a micro-adhesive film obtained by laminating a urethane-based and / or acrylic-based re-peelable adhesive layer onto a PET film, etc. The release layer is preferably, for example, composed of a release layer such as silicone provided on the surface of the substrate layer as described above. Such a release layer is peeled off during the manufacturing process or during use, and removed from the decorative film or decorative molded body.

[0074] Examples of substrates with decorative layers include the following layer configurations. Furthermore, to bond the layers together, adhesive layers or easy-to-bond material layers can be provided between the layers as needed.

[0075] (1) It consists of a substrate layer, a printing layer, and a printing protective layer arranged sequentially.

[0076] (2) It consists of a surface protective layer, a printing layer, and a substrate layer arranged in sequence.

[0077] (3) The structure consists of a substrate layer and a printing layer arranged sequentially.

[0078] (4) It consists of a functional layer, a substrate layer, and a printing layer arranged in sequence.

[0079] (Generally, this configuration is used for membrane embedding rather than in-mold molding.)

[0080] (5) The substrate layer, release layer, printing protective layer and printing layer are arranged in sequence.

[0081] (Generally, this configuration is used for in-mold molding rather than for membrane embedding molding)

[0082] (6) A protective film is further provided on the outermost surface of the above-mentioned (1) to (5) structures.

[0083] (7) The outermost surface of the above-mentioned (1) to (5) structures is further provided with an adhesive layer and an isolation layer.

[0084] When an adhesive layer is provided to bond the various layers together, known adhesives can be used as the adhesive constituting the adhesive layer. Examples of adhesives include natural rubber-based adhesives, synthetic rubber-based adhesives, acrylic adhesives, urethane-based adhesives, and silicone-based adhesives. The adhesive can be any of the following: solvent-based, solvent-free, emulsion-based, or water-based.

[0085] (Polypropylene layer)

[0086] The decorative film has a polypropylene layer. The thickness of the polypropylene layer is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more. Furthermore, the thickness of the polypropylene layer is preferably 30 μm or less, more preferably 25 μm or less, even more preferably 20 μm or less, even more preferably 15 μm or less, and particularly preferably 10 μm or less.

[0087] (Manufacturing method of decorative film)

[0088] The method for manufacturing the decorative film of the present invention includes the steps of: forming an adhesive layer by coating an adhesive composition onto a substrate having a decorative layer and allowing it to dry or cure; and forming a polypropylene layer or laminating a polypropylene film onto the adhesive layer. Alternatively, the method for manufacturing the decorative film of the present invention may include the steps of: forming an adhesive layer by coating an adhesive composition onto a polypropylene layer and allowing it to dry or cure; and laminating a substrate having a decorative layer onto the adhesive layer.

[0089] Adhesive compositions can be coated using existing methods. When using adhesive compositions manufactured by dissolving in a solvent, they can be coated with a doctor blade coater and then dried in a drying oven to achieve sheet formation. Conversely, when using adhesives manufactured by a heated mixing method, sheet formation can be achieved using a hot melt coater capable of softening the adhesive composition through preheating.

[0090] When forming a polypropylene layer on an adhesive layer formed on a substrate with a decorative layer, a method of laminating a polypropylene film onto the adhesive layer and then pressing it together can be used. Existing laminating machines can be used as the laminating method. For example, the adhesive layer and the polypropylene layer can be laminated in combinations such as roll-to-roll, sheet-to-roll, roll-to-sheet, or sheet-to-sheet. In this case, it is preferable to apply pressure while laminating using rollers or similar equipment. Furthermore, when an adhesive layer is formed on the polypropylene layer, the substrate with the decorative layer can also be laminated using the same method.

[0091] In addition, when forming a polypropylene layer on an adhesive layer formed on a substrate with a decorative layer, a polypropylene layer can be formed on the adhesive layer by using an extrusion lamination method and by using melt extrusion through a T-die.

[0092] (Decorative molding)

[0093] The present invention also relates to a decorative molded article formed by bonding a decorative film to an adhesive comprising polypropylene resin. Furthermore, in the decorative molded article, the adhesive and at least the decorative film (or, in the case of in-mold molding, a decorative layer) are integrated via a polypropylene layer, and at least a portion of the surface of the adhesive is covered by the decorative film (or decorative layer).

[0094] Figure 2 A cross-sectional view illustrating an example of the composition of a decorative molded body. For example... Figure 2 As shown, the decorative molded body 100 has a structure in which a decorative film 30 is laminated onto the substrate 50. Figure 2 As shown, the decorative film 30 includes a substrate (or a decorative layer in the case of in-mold molding) 10 with a decorative layer, an adhesive layer 12, and a polypropylene layer 14, the polypropylene layer 14 being directly bonded to the substrate 50. Additionally, in Figure 2 In order to easily understand the composition of the decorative molded body 100, the polypropylene layer 14 is depicted as a layer. However, in the actual decorative molded body, the polypropylene layer 14 is sometimes integrated with the adhered object 50, and its boundary is unknown.

[0095] The adherend contains polypropylene resin. Here, the adherend contains polypropylene resin as a main component. Specifically, the content of polypropylene resin in the adherend is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. Alternatively, the content of polypropylene resin in the adherend can be 100% by mass, and the adherend can also be made of polypropylene resin.

[0096] The shape of the adherend containing polypropylene resin is not particularly limited; it can be plate-shaped or have a three-dimensional shape. Furthermore, the adherend may have an uneven texture on a portion of its surface.

[0097] Decorative molded bodies are preferably used in automotive components, electronic devices, or building materials. This invention can relate to automotive components, electronic devices, or building materials comprising the aforementioned decorative molded bodies. Examples of automotive components include, for example, body panels, bumpers, spoilers, mirrors, wheels, logos, and interior trim. Examples of electronic devices include home appliances and liquid crystal displays such as personal computers. Examples of building materials include furniture and building materials. Furthermore, the adhered objects can be road materials (e.g., traffic signs, sound barriers), tunnel materials (e.g., sidewall panels), musical instruments, containers, office supplies, sporting goods, toys, etc.

[0098] (Manufacturing method for decorative molded objects)

[0099] The preferred method for manufacturing a decorative molded body includes a step of attaching a decorative film to a substrate. Examples of manufacturing methods for decorative molded bodies include hot pressing, in-mold molding, film embedding molding, and molding under vacuum or reduced pressure conditions. Among these, the preferred method is film embedding molding or in-mold molding, and the decorative film is a suitable decorative film for decorative molding in either method.

[0100] As a method for manufacturing a decorative molded body, in the case of in-mold molding, a decorative film is fixed inside the mold of an injection molding machine, a resin composition with polypropylene resin as the main component constituting the adherend is injected into the mold, and after the resin composition is cured, only the substrate with the decorative layer is removed to obtain a decorative molded body. Alternatively, as a method for manufacturing a decorative molded body, in the case of film embedding molding, a decorative film is fixed inside the molding die of an injection molding machine, a resin composition with polypropylene resin as the main component is injected into the molding die, and the resin composition is cured to obtain a decorative molded body.

[0101] Example

[0102] The features of the present invention are further illustrated below with examples and comparative examples. The materials, amounts, proportions, processing contents, processing steps, etc., shown in the following examples can be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as limited by the specific examples shown below.

[0103] <Preparation of Adhesive Compositions>

[0104] Adhesive composition (A-1)

[0105] An adhesive composition (A-1) was obtained by dissolving 100 parts by weight of a block copolymer (Clares Co., Septon 1020) having the structure shown below, 60 parts by weight of a terpene resin (YS Reijin PX 1150, softening point 115°C, number average molecular weight 1000) and 0.6 parts by weight of an antioxidant (BASF Co., IRGANOX 1010) in toluene at a solids concentration of 30% by weight.

[0106]

[0107] Adhesive composition (A-2)

[0108] As a block copolymer, a resin having the structure shown in the following structural formula (Kurare Co., Ltd., Septon 2002) was used. Otherwise, an adhesive composition (A-2) with a solid content concentration of 30% by mass was obtained by operating in the same manner as the preparation method of the adhesive composition (A-1).

[0109]

[0110] Adhesive composition (A-3)

[0111] As a block copolymer, a resin (Clares Corporation, Septon 4033) having the structure shown in the following structural formula was used. Otherwise, an adhesive composition (A-3) with a solid content concentration of 30% by mass was obtained by operating in the same manner as the preparation method of the adhesive composition (A-1).

[0112]

[0113] Adhesive composition (A-4)

[0114] The terpene resin (manufactured by Yasuharakemica Co., Ltd., YS Reijin PX 1150, softening point 115℃, number average molecular weight 1000) was changed to terpene resin (manufactured by Yasuharakemica Co., Ltd., YS Reijin PX 800, softening point 80℃, number average molecular weight 700), and the amount added was further changed to 100 parts by mass. Otherwise, the same method as the preparation method of adhesive composition (A-3) was used to obtain adhesive composition (A-4) with a solid component concentration of 30% by mass.

[0115] Adhesive composition (A-5)

[0116] The terpene resin (manufactured by Yasuharakemica Co., Ltd., YS Regin PX 1150, softening point 115℃, number average molecular weight 1000) was changed to an aromatic modified terpene resin (manufactured by Yasuharakemica Co., Ltd., YS Regin TO 125, softening point 125℃, number average molecular weight 800). Otherwise, the same procedure as that used to prepare the adhesive composition (A-3) was followed to obtain an adhesive composition (A-5) with a solid content concentration of 30% by mass.

[0117] Adhesive composition (A-6)

[0118] The resin was changed to terpene phenol resin (manufactured by Yasuharake Mikaru Co., Ltd., YS Polyster T 80, softening point 80°C, number-average molecular weight 500). Otherwise, the same method as that used to prepare the adhesive composition (A-3) was followed to obtain an adhesive composition (A-6) with a solid content concentration of 30% by mass.

[0119] Adhesive composition (B-1)

[0120] Instead of block copolymers having a structure derived from isopentane, hydrogenated polybutadiene resin (Kurare Co., Septon 8004) with the following structural formula, which does not have a structure derived from isopentane, was used. Otherwise, adhesive composition (B-1) with a solid content of 30% by mass was obtained by operating in the same manner as the preparation method of adhesive composition (A-1).

[0121]

[0122] Adhesive composition (B-2)

[0123] Instead of terpene resin, a styrene-based resin (Mitsui Chemicals, FTR8100, number average molecular weight 800) was used. Otherwise, the adhesive composition (B-2) with a solid content concentration of 30% by mass was obtained by operating in the same manner as the adhesive composition (A-3).

[0124] Adhesive composition (C-1)

[0125] In a reaction vessel equipped with a stirrer, nitrogen inlet pipe, thermometer, and reflux cooling pipe, n-butyl acrylate (BA) and 2-hydroxyethyl acrylate (2HEA) were mixed at a mass ratio of 80:20. 2,2'-azobis(2,4-dimethylpentanonitrile) was dissolved in the solution as a free radical polymerization initiator. The monomer components were randomly copolymerized by heating the solution to 60°C, resulting in a copolymer solution. 0.11 parts by mass of a phthalimide diisocyanate compound (manufactured by Mitsui Chemicals Co., Ltd., Tapene D-110N) were added as a crosslinking agent to 100 parts by mass of the obtained copolymer, and ethyl acetate was added at a solids concentration of 30% by mass to obtain an adhesive composition (C-1).

[0126] Adhesive composition (C-2)

[0127] As the acid component, terephthalic acid, isophthalic acid, and adipic acid were mixed in a mass ratio of 30:30:40. As the diol component, 1,4-butanediol and 1,6-hexanediol were mixed in a mass ratio of 25:75. The mixture was heated in the presence of a catalyst (tetrabutyl titanate) to obtain a thermoplastic saturated copolyester resin. The obtained thermoplastic saturated copolyester resin was dissolved in a solvent (methyl ethyl ketone) and diluted with stirring to a solution with a solid content concentration of 30% by mass. Next, 2 parts by mass of polyisocyanate (Polyurett Corporation of Japan, "Coronate HX" (1,6-hexanediisocyanate), 100% by mass) relative to 100 parts by mass of the thermoplastic saturated copolyester resin were added to the solution to obtain an adhesive composition (C-2).

[0128] <Production of Decorative Film>

[0129] (Example 1)

[0130] Using a doctor blade coater, the adhesive composition (A-1) prepared above was coated onto an acrylic film (Clare Co., Parapula HI grade 75μm) to achieve a 5μm thickness of adhesive layer after drying. The film was then dried at 100°C for 3 minutes to allow the toluene solvent to evaporate. Next, a polypropylene film (Oji Effiex Co., EM-501 5μm) was applied to the adhesive layer side using a hand roller to obtain a decorative film.

[0131] (Example 2)

[0132] The adhesive composition (A-1) was changed to adhesive composition (A-2), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0133] (Example 3)

[0134] The adhesive composition (A-1) was changed to adhesive composition (A-3), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0135] (Example 4)

[0136] The adhesive composition (A-1) was changed to the adhesive composition (A-4), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0137] (Example 5)

[0138] The adhesive composition (A-1) was changed to adhesive composition (A-5), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0139] (Example 6)

[0140] The adhesive composition (A-1) was changed to adhesive composition (A-6), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0141] (Example 7)

[0142] The thickness of the dried adhesive layer was changed to 1 μm, and the polypropylene film was changed to a polypropylene film with a thickness of 20 μm (manufactured by Oji Eftex Co., Ltd., SS-121 20 μm). Otherwise, the same procedure as in Example 3 was followed to obtain the decorative film.

[0143] (Example 8)

[0144] The thickness of the dried adhesive layer was changed to 20 μm, and the polypropylene film was made into a 12 μm thick polypropylene film (manufactured by Oji Eftex Co., Ltd., MAM-411 12 μm). Otherwise, the same procedure as in Example 3 was followed to obtain the decorative film.

[0145] (Comparative Example 1)

[0146] A decorative film without a polypropylene layer was obtained by operating in the same manner as in Example 1, except that the polypropylene film was not laminated.

[0147] (Comparative Example 2)

[0148] The adhesive composition (A-1) was changed to adhesive composition (B-1), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0149] (Comparative Example 3)

[0150] The adhesive composition (A-1) was changed to adhesive composition (B-2), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0151] (Comparative Example 4)

[0152] The adhesive composition (A-1) was changed to adhesive composition (C-1), and otherwise the same procedure as in Example 1 was followed to obtain the decorative film.

[0153] (Comparative Example 5)

[0154] The adhesive composition (A-1) was changed to the adhesive composition (C-2), and otherwise the same procedure as in Comparative Example 1 was followed to obtain a decorative film.

[0155] (Fitness assessment)

[0156] <The Making of Decorative Molded Components>

[0157] Using the decorative films obtained in the various embodiments and comparative examples, decorative molded bodies were manufactured by a film embedding molding method. First, a decorative film was placed inside a plate-shaped mold with a size of 100mm × 100mm × 2mm, with a polypropylene layer as the injection resin side. Next, the mold with the decorative film placed was heated to 60°C, and polypropylene (manufactured by Mitsubishi Kemica Co., Ltd., Nobatek) that had been heated to 200°C and molten was then injected. TM PP is injected into the mold, cooled to room temperature, and then the decorative molded body is removed from the mold to obtain the decorative molded body.

[0158] <Evaluation>

[0159] After curing the above-prepared decorative molded body at 23°C and 50% relative humidity for 24 hours, the adhesion between the decorative film and the polypropylene resin substrate was evaluated according to JISK 5600-5-6. Specifically, an adhesion test was conducted using the grid method as follows.

[0160] First, using a razor, 100 cuts were made from the decorative film side in a 1mm x 1mm checkerboard pattern. Then, celluloid tape (made by Nichiban Co., Ltd., CT28) was pressed from above with fingers to ensure it adhered tightly to the decorative film, and then peeled off. Within the 100 cuts, the number of cuts where the decorative film was not peeled off was recorded as 100 / 100, and the number of cuts where the film was peeled off was recorded as 0 / 100. The adhesion of the decorative film was evaluated using the following criteria after counting the number of cuts where the film was not peeled off.

[0161] A: 80 / 100~100 / 100

[0162] B: 50 / 100~79 / 100

[0163] C: 0 / 100~49 / 100

[0164] (Evaluation of the mold's resistance to sticking)

[0165] The decorative films obtained in the various embodiments and comparative examples were used to evaluate their resistance to adhesion to the mold (mold sealing performance). First, a material was prepared by cutting the decorative film into 25mm × 300mm pieces. This decorative film was then pressed onto a SUS304 steel sheet (surface finished BA) heated to 50°C using a 2kg roller according to JIS Z 0237. Adhesion was measured 5 minutes after pressing at a peel speed of 300mm / min and a peel angle of 180°, and evaluated using the following criteria.

[0166] A: Adhesion force less than 0.05 N / 25 mm

[0167] B: Adhesion strength is 0.05N / 25mm or higher.

[0168]

[0169]

[0170] The decorative film obtained in the examples exhibits good adhesion to the polypropylene resin substrate. Furthermore, the decorative film obtained in the examples demonstrates good resistance to mold adhesion. On the other hand, the decorative film obtained in the comparative examples does not simultaneously possess both good adhesion to the polypropylene resin substrate and resistance to mold adhesion.

[0171] Explanation of symbols

[0172] 10. Substrate with decorative layer

[0173] 12 Adhesive Layer

[0174] 14 Polypropylene layer

[0175] 30 Decorative film

[0176] 50 Adhesives

[0177] 100 Decorative molded parts.

Claims

1. A decorative film (30) for decorating an adhesive comprising polypropylene resin, said decorative film (30) being characterized in that it comprises: Substrate with a decorative layer (10); Adhesive layer (12); and Polypropylene layer (14), in, The substrate (10) with the decorative layer, the adhesive layer (12), and the polypropylene layer (14) are sequentially stacked. The adhesive layer (12) contains: Block copolymers comprising blocks made of isopentane-derived structures and blocks made of styrene-based polymers; and Terpenoid resins The terpene resin is selected from at least one of terpene resins, aromatic modified terpene resins, and terpene phenol resins. The softening point of the terpene resin is 60–130°C. The number-average molecular weight of the terpene resin is 300–1500. The structure derived from isopentane has the following structure.

2. The decorative film (30) according to claim 1, wherein the content of the terpene resin is 40 to 200 parts by weight relative to 100 parts by weight of the block copolymer.

3. The decorative film (30) according to claim 1 or 2, wherein the thickness of the adhesive layer is 0.5 to 20 μm.

4. The decorative film (30) according to claim 1 or 2, wherein the thickness of the polypropylene layer is 1 to 30 μm.

5. The decorative film (30) according to claim 1 or 2, used for decorating an adhered object by means of film embedding or in-mold molding.

6. A decorative molded body formed by bonding the decorative film (30) of claim 1 or 2 to an adhesive comprising polypropylene resin.

7. The decorative molded body according to claim 6, which is used in automotive components, electronic devices or building materials.

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