Decorative sheet and method for manufacturing decorative molded article

Abstract

[Problem] The purpose of the present invention is to provide a decorative sheet which has excellent moldability and chemical resistance and in which a two-component curable urethane resin that is a thermosetting resin is used, and a decorative molded article in which the decorative sheet is used. [Solution] A decorative molded article 20 includes a resin molded body 21, has a decorative sheet 10 formed on the resin molded body 21, and is such that a backer sheet 16, an adhesive layer 15, a pattern layer 14, a base sheet 11, a matte layer 12, and a matte pattern layer 13 are stacked in order from the resin-molded-body 21 side. The base sheet has a glass transition temperature of 80-110°C and a thickness of 75-125 μm. The matte layer 12 includes a first binder resin and a first matte material. The matte pattern layer 13 includes a second binder resin and a second matte material. The first binder resin and the second binder resin are two-component curable urethane-based resins that are cured products of a polyol and an isocyanate-based curing agent, and the ratio (NCO / OH) of isocyanate groups of the isocyanate-based curing agent to hydroxyl groups of the polyol is 1.1-2.0.

Description

Method for manufacturing decorative sheet and decorative molded product

[0001] The present invention relates to a decorative sheet having excellent formability and chemical resistance, a decorated molded article using the same, and a method for manufacturing the decorated molded article.

[0002] Traditionally, decorative molded products in which a decorative sheet is laminated onto the surface of a resin molded product have been used for vehicle interior and exterior parts, building and interior materials, home appliances, etc. In line with the recent trend toward luxury among consumers, there is a demand for decorative molded products with a three-dimensional appearance that can be recognized when the exterior is observed visually, and a luxurious design.

[0003] For example, Patent Document 1 discloses a decorative sheet having a base layer, a first protective layer provided on the base layer, and a second protective layer partially provided on the first protective layer, with a three-dimensional effect given by the difference in gloss and uneven shape between the second protective layer and the first protective layer.

[0004] JP 2016-190329 A

[0005] In the conventional decorative sheets described above, the first protective layer is formed from a cured product of an ionizing radiation curable resin composition. However, the use of an ionizing radiation curable resin requires a process for irradiating ionizing radiation and an increase in the size of the equipment, which can reduce productivity. Furthermore, when a thermosetting resin is used instead of an ionizing radiation curable resin, although it does not require as large an equipment as the ionizing radiation curable resin, sufficient moldability and chemical resistance may not be obtained.

[0006] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a decorative sheet that uses a two-component curing urethane resin, which is a thermosetting resin, and has good formability and chemical resistance, as well as a decorated molded product that uses this decorative sheet.

[0007] In order to achieve the above object, a first invention provides a decorative sheet comprising: a base sheet having a glass transition temperature of 80 to 110°C and a thickness of 75 to 125 μm; a matte layer formed on the base sheet; and a matte pattern layer formed on the matte layer, wherein the matte layer contains a first binder resin and a first matting material, and the matte pattern layer contains a second binder resin and a second matting material, and the first binder resin and the second binder resin are two-component curing urethane resins that are cured products of polyol and an isocyanate-based curing agent, and the ratio (NCO / OH) of isocyanate groups in the isocyanate-based curing agent to hydroxyl groups in the polyol is 1.1 to 2.0.

[0008] By configuring it in this way, the base sheet has appropriate bendability, and the two-component curing urethane resin that forms the matte layer and matte pattern layer undergoes an appropriate crosslinking reaction, thereby providing a decorative sheet with excellent formability and chemical resistance.

[0009] In a second aspect of the present invention, in the first aspect, the first matting agent is inorganic particles, and the second matting agent contains resin particles.

[0010] In this configuration, the inorganic particles of the first matting material do not easily repel the binder resin applied as an overcoat, improving the film-forming properties of the binder resin of the matte pattern layer formed on the matte layer, thereby providing a decorative sheet with excellent design and chemical resistance.Furthermore, the inclusion of resin particles in the second matting material allows for the provision of a decorative sheet with excellent tactile feel and scratch resistance.

[0011] A third invention is the first or second invention, wherein the base sheet contains an acrylic resin.

[0012] With this configuration, the formability and impact resistance of the base sheet are improved, making it possible to provide a decorative sheet with excellent formability.

[0013] In a fourth aspect of the present invention, the decorative sheet according to the third aspect of the present invention has an Erichsen value of 12.0 to 14.9 mm as measured by the Erichsen test method.

[0014] With this configuration, the decorative sheet can have both the bendability and the strength required for processing, thereby providing a decorative sheet with excellent formability.

[0015] A fifth invention is a decorated molded article comprising: a resin molded body; a base sheet formed on the resin molded body, the base sheet having a glass transition temperature of 80 to 110°C and a thickness of 75 to 125 μm; a matte layer formed on the base sheet; and a matte pattern layer formed on the matte layer, wherein the matte layer contains a first binder resin and a first matting material, and the matte pattern layer contains a second binder resin and a second matting material, the first binder resin and the second binder resin are two-component curing urethane resins that are cured products of a polyol and an isocyanate-based curing agent, and the ratio (NCO / OH) of isocyanate groups in the isocyanate-based curing agent to hydroxyl groups in the polyol is 1.1 to 2.0.

[0016] With this configuration, it is possible to provide a decorated molded product that has good moldability and chemical resistance and is highly productive.

[0017] A sixth invention provides a laminate comprising a base sheet having a glass transition temperature of 80 to 110°C and a thickness of 75 to 125 μm, a matte layer formed on the base sheet, and a matte pattern layer formed on the matte layer, wherein the matte layer contains a first binder resin and a first matting material, and the matte pattern layer contains a second binder resin and a second matting material, and the first binder resin and the second binder resin are two-component curing urethane resins that are cured products of polyol and an isocyanate-based curing agent, and the isocyanate in the isocyanate-based curing agent is a cured product of the first binder resin and the second binder resin. the ratio of NCO groups to hydroxyl groups in the polyol (NCO / OH) is 1.1 to 2.0; placing the decorative sheet on the cavity surface of the first or second mold of an injection molding die having a first mold and a second mold that forms a cavity between the first mold and the second mold by clamping; clamping the injection molding die; injecting molten resin into the cavity to form a resin molded body while simultaneously fixing the decorative sheet to the surface of the resin molded body; and opening the injection molding die and removing the resin molded body.

[0018] This manufacturing method uses insert molding or in-mold molding, making it possible to manufacture decorated molded products with complex shapes. In addition, the number of manufacturing steps is reduced, making it possible to reduce production costs and production time.

[0019] According to this invention, a decorative sheet having good moldability and chemical resistance can be provided by using a two-component curing urethane resin, which is a thermosetting resin.

[0020] Fig. 2 is a perspective view of a decorated molded product according to a first embodiment of the present invention. Fig. 3 is a schematic cross-sectional view taken along the line II-II shown in Fig. 1. Fig. 4 is a cross-sectional view showing a schematic configuration of a decorative sheet according to a first embodiment of the present invention. Fig. 5 is a cross-sectional view showing a method for manufacturing a decorated molded product according to a first embodiment of the present invention.

[0021] A decorated molded product 20 according to a first embodiment of the present invention will be described with reference to the drawings.

[0022] [Regarding the Decorative Molded Product] Referring to FIG. 1 , the decorative molded product 20 has a rectangular shape in a planar view and includes a flat plate-shaped planar portion 61 and raised portions 62 that rise downward at the same height from two short sides of the planar portion 61. The two opposing raised portions 62 are connected at an obtuse angle to the planar portion 61 so as to move away from each other as they rise downward. The decorative molded product 20 includes a resin molded body 21 and a decorative sheet 10 formed on the resin molded body 21. Referring to FIG. 2 , the decorative molded product 20 includes a backer sheet 16, an adhesive layer 15, a pattern layer 14, a base sheet 11, a matte layer 12, and a matte pattern layer 13 laminated in this order on the resin molded body 21. The decorative molded product 20 is formed by insert molding or in-mold molding using the decorative sheet 10, with each layer being formed on the resin molded body 21.

[0023] 3, the decorative sheet 10 has a laminated structure in which a matte layer 12 and a matte pattern layer 13 are laminated in this order on one surface of a base sheet 11, and a design layer 14, an adhesive layer 15, and a backer sheet 16 are laminated in this order on the surface of the base sheet 11 on which the matte layer 12 is not formed. The matte pattern layer 13 is also partially provided on the matte layer 12. On the surface of the matte layer 12, an uneven shape is formed by the portions where the matte pattern layer 13 is provided and the portions where the matte pattern layer 13 is not provided.

[0024] [Composition of Each Layer Constituting the Decorative Molded Product] [Resin Molded Body 21] Examples of materials for the resin molded body 21 include general-purpose resins such as polystyrene resins, polyolefin resins, ABS resins, AS resins, and AN resins; general-purpose engineering resins such as polyphenylene oxide-polystyrene resins, polycarbonate resins, polyacetal resins, acrylic resins, polycarbonate-modified polyphenylene ether resins, polybutylene terephthalate resins, and ultra-high molecular weight polyethylene resins; and super engineering resins such as polysulfone resins, polyphenylene sulfide resins, polyphenylene oxide resins, polyarylate resins, polyetherimide resins, polyimide resins, liquid crystal polyester resins, and heat-resistant polyallyl resins. Furthermore, reinforcing materials such as glass fiber and inorganic fillers may be added as appropriate.

[0025] [Base Sheet 11] In the decorative sheet 10 of the first embodiment, the base sheet 11 is a layer formed by laminating a matte layer 12 and a matte pattern layer 13 and serving as a support for the decorative sheet. The base sheet 11 is formed of a thermoplastic resin, such as a polycarbonate-based resin, an acrylic-based resin, an ethylene-based resin, a propylene-based resin, a polyolefin-based resin, a polyester-based resin, a polyamide-based resin, polyvinyl chloride, or an ABS resin. The base sheet 11 may be formed by using one of these resins alone or by mixing two or more of them. It may also be formed by stacking multiple sheets of the same or different types. The components of the thermoplastic resin are not particularly limited, but it is preferable that it contains an acrylic resin from the standpoint of formability and impact resistance. Rubber particles may also be added to the base sheet. The addition of rubber particles can increase toughness. The base sheet 11 may also contain, as appropriate, dispersants, antioxidants, compatibilizers, UV stabilizers, antiblocking agents, antistatic agents, and the like.

[0026] The glass transition temperature of the substrate sheet 11 is preferably 80° C. or higher and 110° C. or lower, and more preferably 90° C. or higher and 110° C. or lower. A glass transition temperature of 80° C. or higher provides excellent bendability, and a glass transition temperature of 90° C. or higher provides excellent formability. A glass transition temperature of 110° C. or lower provides the strength required for processing and excellent trimming properties.

[0027] The thickness of the base sheet 11 is preferably 60 μm or more and 140 μm or less, and more preferably 75 μm or more and 125 μm or less. A thickness of 60 μm or more provides the strength required for processing, and a thickness of 75 μm or more provides excellent trimming properties. A thickness of 140 μm or less provides good moldability. A thickness of 125 μm or less provides a decorative sheet with excellent design during injection molding.

[0028] [Matte Layer 12] The matte layer 12 is a layer that gives the decorative sheet 10 a three-dimensional appearance by virtue of the difference in gloss from the matte pattern layer 13 and its uneven shape, and is provided on the base sheet 11. The matte pattern layer 13 is partially provided on the matte layer 12. Therefore, the matte pattern layer 13 forms the outermost layer of the decorative sheet 10 in the area where the matte pattern layer 13 is provided, and the matte layer 12 forms the outermost layer of the decorative sheet 10 in the area where the matte pattern layer 13 is not provided. In the decorative sheet 10 of the first embodiment, the matte layer 12 contains a first binder resin and a first matting material. The first binder resin is a two-component curing urethane resin, which is a thermosetting resin. The two-component curing urethane resin is a resin that is cured by adding an isocyanate curing agent to a polyol, which is a main component, and forming a crosslinked structure when urethane bonds are generated between the hydroxyl groups in the polyol and the isocyanate groups in the isocyanate curing agent. The two-component curing urethane resin is not particularly limited, but examples include those containing a polyol component having hydroxyl groups (e.g., acrylic polyol, polyester polyol, polyether polyol, epoxy polyol, etc.) as the base component and an isocyanate component (e.g., tolylene diisocyanate, hexamethylene diisocyanate, meta-xylene diisocyanate, etc.) as the curing agent component. Among these, from the viewpoint of achieving both light resistance and processability, it is preferable to use an acrylic polyol as the base component and meta-xylene diisocyanate as the curing agent. Furthermore, the first binder resin may be a two-component curing urethane resin alone, or it may be mixed with other resins. Examples of other resins include acrylic resins, urethane resins, thermoplastic polyester resins, and soluble nitrocellulose. Plasticizers, stabilizers, catalysts, and curing agents may also be added as appropriate.

[0029] The NCO / OH ratio, which is the ratio of the isocyanate groups in the isocyanate-based curing agent to the hydroxyl groups in the polyol, of the two-component curing urethane resin that forms the matte layer 12 is 1.1 to 2.0. If the NCO / OH ratio is 2.0 or less, excessive progress of the crosslinking reaction is suppressed, the matte layer does not become too hard, and the decorative sheet is less likely to crack during three-dimensional molding. On the other hand, if the NCO / OH ratio is 1.1 or more, the progress of the crosslinking reaction is promoted, improving the chemical resistance of the matte layer. By allowing the crosslinking reaction of the two-component curing urethane resin to proceed appropriately, a decorative sheet with excellent moldability and chemical resistance can be provided.

[0030] The first matting material may be inorganic particles or resin particles. The first matting material can adjust the gloss and provide a gloss difference between the matte layer 12 and the matte pattern layer 13. The first matting material can also improve scratch resistance.

[0031] Examples of inorganic particles that can be used include amorphous silica, spherical silica, alumina, kaolinite, calcium carbonate, barium sulfate, and glass. Of these, amorphous silica is preferred from the viewpoints of scratch resistance and printability. The inorganic particles may be used alone or in combination of two or more types.

[0032] The content of the inorganic particles is not particularly limited, but is preferably 20 parts by mass or more and 70 parts by mass or less, and more preferably 40 parts by mass or more and 60 parts by mass or less, relative to 100 parts by mass of the first binder resin. If it is 20 parts by mass or more, improved scratch resistance is obtained. If it is 40 parts by mass or more, the inorganic particles are distributed over the entire surface, resulting in a good matte effect. If it is 70 parts by mass or less, the occurrence of cracks during shaping is suppressed, and if it is 60 parts by mass or less, good moldability is maintained.

[0033] The particle size of the inorganic particles is preferably 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 8 μm or less. If it is 1 μm or more, a portion of the inorganic particles is easily exposed from the surface of the matte layer, resulting in a good matte effect. If it is 2 μm or more, scratch resistance is improved. If it is 10 μm or less, excellent moldability is achieved, and if it is 8 μm or less, the inorganic particles are distributed throughout the entire surface, resulting in a good matte effect and improved scratch resistance. In the present invention, the average particle size is a volume-based average arithmetic value obtained by a laser diffraction / scattering method, and includes not only the primary particle size but also the secondary particle size, which is a particle aggregate.

[0034] As the resin particles, organic beads such as urethane resin, acrylic resin, polycarbonate resin, polyamide (nylon) resin, urea resin, silicon-based resin, etc. may be used. The resin particles may be used alone or in combination of two or more types.

[0035] The content of the resin particles is not particularly limited, but may be, for example, in the range of 5 to 25 parts by mass relative to 100 parts by mass of the first binder resin. At least 5 parts by mass provides a good tactile feel, while at most 25 parts by mass provides good moldability. The average particle diameter of the resin particles may be, for example, in the range of 5 μm to 30 μm.

[0036] It is preferable to use only inorganic particles as the first matting material. When inorganic particles whose particle size can be easily adjusted to a small size are used, the inorganic particles as the first matting material are less likely to repel the binder resin that is applied as an overcoat, improving the film-forming properties of the binder resin of the matte pattern layer formed on the matte layer, thereby obtaining a decorative sheet with excellent design and chemical resistance.

[0037] When the matte layer 12 contains these particles, the particles are dispersed throughout the matte layer 12 .

[0038] The thickness of the matte layer 12 is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 10 μm or less. A thickness of 1 μm or more provides good scratch resistance, and a thickness of 2 μm or more provides good chemical resistance. A thickness of 20 μm or less provides good formability, and a thickness of 10 μm or less allows a portion of the first matte material to be exposed from the surface of the matte layer, resulting in a good matte effect. The thickness of the matte layer 12 refers to the thickness of the portion where the first matte material is not located on the surface of the matte layer 12.

[0039] [Matte Pattern Layer 13] The matte pattern layer 13 is a layer that imparts a three-dimensional feel and a tactile sensation to the decorative sheet by virtue of its difference in gloss from the matte layer 12 and its uneven shape, and is partially disposed on the matte layer 12. For example, the matte pattern layer 13 can be made less matte (matte feel) than the matte layer 12. The matte pattern layer 13 may be partially disposed so as to match the pattern of the design layer 14. By matching the uneven shape of the matte pattern layer 13 to the pattern of the design layer 14, a three-dimensional feel and a tactile sensation that are in harmony with the design can be imparted. "In harmony with the pattern of the design layer 14" does not necessarily mean that the outer shape of the matte pattern layer 13 matches the outer shape of the design layer 14. For example, the matte pattern layer 13 may have convex portions inside the pattern formed by the design layer 14, or the matte pattern layer 13 may have convex portions outside the pattern formed by the design layer 14. Furthermore, the matte pattern layer 13 may have an uneven shape that matches only a specific pattern (color or shape) formed by the design layer 14. In the decorative sheet 10 of the first embodiment, the matte pattern layer 13 includes a second binder resin and a second matting material. The second binder resin is a two-component curing urethane resin, which is a thermosetting resin. The NCO / OH ratio, which is the ratio of isocyanate groups in the isocyanate-based curing agent to hydroxyl groups in the polyol, is 1.1 to 2.0. The two-component curing urethane resin used for the second binder resin can be the same material as the first binder resin for the matte layer 12. From the viewpoint of achieving both light resistance and processability, it is preferable to use an acrylic polyol as the base resin and metaxylene diisocyanate as the curing agent. Furthermore, the second binder resin may be a two-component curing urethane resin alone, or a two-component curing urethane resin mixed with other resins. Examples of other resins include acrylic resins, urethane resins, thermoplastic polyester resins, and soluble nitrocellulose. Plasticizers, stabilizers, catalysts, and curing agents may also be added as appropriate. The base resin and curing agent of the second binder resin and the first binder resin may be the same or different. The NCO / OH ratios may also be the same or different.

[0040] The second matting material can be resin particles or inorganic particles. The second matting material can adjust the gloss and create a gloss difference between the matte layer 12 and the matte pattern layer 13. The second matting material preferably contains resin particles. The resin particles can improve the tactile feel and scratch resistance.

[0041] The resin particles may be made of the same material as the first matting material of the matte layer 12 described above.

[0042] The content of the resin particles is not particularly limited, but from the viewpoint of providing a tactile feel, it is preferably 5 parts by mass or more and 30 parts by mass or less, and more preferably 10 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the second binder resin. If it is 5 parts by mass or more, scratch resistance is improved, and if it is 10 parts by mass or more, the resin particles are distributed over the entire surface, resulting in a good matte effect and tactile feel. If it is 30 parts by mass or less, cracking during shaping is suppressed, and if it is 20 parts by mass or less, good moldability is maintained.

[0043] From the viewpoint of printability and tactile feel, the particle diameter of the resin particles is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 30 μm or less. If the particle diameter is 5 μm or more, a good matte effect is obtained. If it is 10 μm or more, a portion of the resin particles is exposed from the surface of the matte layer, resulting in a good tactile feel. Furthermore, if the particle diameter is 50 μm or less, a good coating film appearance is obtained, and if it is 30 μm or less, the resin particles are distributed throughout the entire surface, resulting in a good matte effect and improved scratch resistance.

[0044] For example, if resin particles are used as the second matte material, the content of the resin particles is 10 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the second binder resin, and the average particle diameter of the resin particles is 10 μm or more and 30 μm or less, the resin particles are more likely to be localized on the surface of the matte pattern layer 13, and an unevenness that feels smooth to the touch can be imparted to the surface of the decorative sheet.

[0045] It is more preferable that the second matting material contains inorganic particles in addition to resin particles. By adding inorganic particles in addition to resin particles, the scratch resistance of the matte pattern layer 13 can be further improved.

[0046] The inorganic particles may be the same material as the first matting material of the matte layer 12. The content of the inorganic particles is not particularly limited, but may be, for example, in the range of 5 parts by mass to 25 parts by mass per 100 parts by mass of the second binder resin.

[0047] The average particle size of the inorganic particles is, for example, in the range of 1 μm to 10 μm.

[0048] The thickness of the matte pattern layer 13 is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 10 μm or less. A thickness of 1 μm or more provides good scratch resistance, and a thickness of 2 μm or more provides good chemical resistance. A thickness of 20 μm or less provides good formability, and a thickness of 10 μm or less provides good matting effect, with part of the second matte material being exposed from the surface of the matte layer. The thickness of the matte pattern layer 13 refers to the thickness of the portion where the second matte material is not located on the surface of the matte pattern layer 13.

[0049] The height of the convex portions of the matte pattern layer 13 is preferably 5 μm or more and 20 μm or less. If the height of the convex portions is 5 μm or more, changes in the tactile feel of the surface are easily felt, and if it is 20 μm or less, good moldability is maintained. Here, the height of the convex portions is the height from the surface of the matte layer 12 to the highest point of each convex portion.

[0050] The area of ​​the convex portions of the matte pattern layer 13 relative to the area of ​​the entire decorative sheet is preferably 30% or more and 70% or less. If the area of ​​the convex portions relative to the area of ​​the entire decorative sheet is 30% or more, a good tactile feel can be imparted. Furthermore, if the area of ​​the convex portions relative to the area of ​​the entire decorative sheet is 70% or less, the difference in gloss between the matte layer 12 and the matte pattern layer 13 becomes clear, resulting in a three-dimensional design.

[0051] [Pattern Layer 14] The pattern layer 14 is a layer that imparts decorative properties to the decorative sheet and is formed by printing a pattern or color. The pattern formed on the pattern layer 14 is not particularly limited and may be a pattern that imparts a glossy texture to the decorated molded product or a pattern that imparts a matte texture. Woodgrain, leather, metallic, and other patterns are also possible. The pattern layer 14 may be formed by printing directly onto the base sheet 11, or by laminating a sheet with a printed pattern onto the base sheet 11. When printing on a sheet other than the base sheet 11, the sheet that serves as the printing base may be made of, for example, an acrylic resin, a urethane resin, a vinyl chloride-vinyl acetate copolymer resin, or a polyester resin. From the standpoint of light resistance, it is preferable that the sheet that serves as the printing base contain an acrylic resin. The pattern layer 14 may be formed over the entire surface or in any pattern. The pattern layer 14 may be formed to a thickness of, for example, 1 μm or more and 20 μm or less, and preferably to a thickness of 2 μm or more and 7 μm or less. If the thickness is 2 μm or more, the strength is suitable for processing, and if it is 7 μm or less, the moldability is good.

[0052] When the pattern layer 14 is made to have a wood grain pattern, the wood grain pattern can be formed by the vessel portions and the non-vessel portions. Also, the vessel portions of the pattern layer 14 may be formed to match the matte pattern layer 13.

[0053] The design ink used for the design layer 14 is prepared by appropriately blending a binder with a colorant such as a pigment or dye, a solvent, a plasticizer, a stabilizer, a catalyst, a hardener, etc. There are no particular restrictions on the binder or colorant, and known binder resins and colorants can be used.

[0054] [Adhesive Layer 15] The adhesive layer 15 is an optional layer for adhering the base sheet 11 to the backer sheet 16. Known heat- or pressure-sensitive materials can be used for the adhesive layer 15. Examples include acrylic, polystyrene, polyamide, polyolefin, and vinyl chloride-vinyl acetate copolymer resins. The adhesive layer 15 can be formed to a thickness of, for example, 1 μm to 20 μm, preferably 1 μm to 5 μm. A thickness of 1 μm or more improves the adhesion between the base sheet 11 and the backer sheet 16. A thickness of 20 μm or less prevents the adhesive layer from extending beyond the adhesive area between the backer sheet 16 and the base sheet 11, thereby impairing the adhesion between the two layers. A thickness of 5 μm or less improves formability.

[0055] [Backer Sheet 16] In the decorative sheet of the present invention, the backer sheet 16 serves as a support and is adjacent to the molding resin during insert molding or in-mold molding. The material of the backer sheet 16 is not particularly limited, and a thermoplastic resin, for example, can be used. Examples of thermoplastic resins that can be used include polycarbonate-based resins, acrylic-based resins, ethylene-based resins, propylene-based resins, polyolefin-based resins, polyester-based resins, polyamide-based resins, polyvinyl chloride, and ABS resins. The base sheet 11 may contain two or more of these materials or may be a laminate of these materials. The material can be selected appropriately based on compatibility with the molding resin used in injection molding and three-dimensional molding. From the perspective of moldability, ABS resin is preferred. The thickness of the backer sheet 16 is, for example, 200 μm to 600 μm, more preferably 300 μm to 450 μm. A thickness of 300 μm or more improves the supportability of the decorative sheet, while a thickness of 450 μm or less ensures good moldability.

[0056] In the decorative sheet 10 of the first embodiment, a primer layer may be provided between the base sheet 11 and the matte layer 12, or between the base sheet 11 and the pattern layer 14. By providing a primer layer, it is possible to improve adhesion between the base sheet 11 and the adjacent layer and to improve the formability of the decorative sheet. In addition, a concealing layer may be provided between the base sheet 11 and the pattern layer 14. By providing a concealing layer, it is possible to suppress color changes and variations in the base sheet 11. Furthermore, a backer sheet adhesive layer may be provided to improve adhesion with the resin molded body 21.

[0057] [Primer Layer] The primer layer is a layer provided for the purpose of increasing the adhesion of each layer and improving the formability of the decorative sheet, and may be provided, for example, between the base sheet 11 and an adjacent layer. The resin forming the primer layer is not particularly limited, but examples thereof include thermosetting resins such as urethane resin, acrylic resin, and polyester resin. These may be used alone or in a mixture of two or more types. From the viewpoint of suppressing cracking during shaping, it is preferable to provide the primer layer between the base sheet 11 and the matte layer 12. Furthermore, from the viewpoint of good formability, it is preferable to use a two-component curing urethane resin.

[0058] The thickness of the primer layer is preferably 1 μm or more and 20 μm or less, more preferably 1 μm or more and 5 μm or less. A thickness of 1 μm or more provides strength suitable for processing, while a thickness of 20 μm or less, particularly 5 μm or less, provides good formability.

[0059] [Masking Layer] The masking layer is a layer provided to prevent the color of the resin molded body 21 from showing through and causing changes or variations in the color of the decorative sheet when the decorative sheet 10 is attached to the resin molded body 21 for use. For example, the masking layer can be provided as needed between the base sheet 11 and the design layer 14. The ink used for the masking layer is an ink obtained by appropriately blending a binder with a colorant such as a pigment or dye, a solvent, a plasticizer, a stabilizer, a catalyst, a hardener, etc. There are no particular restrictions on the materials for the binder and the colorant, and known materials can be used.

[0060] [Backer Sheet Adhesive Layer] The backer sheet adhesive layer is provided for the purpose of increasing the adhesion between the backer sheet 16 and the resin molded article 21, and can be provided as needed on the surface of the backer sheet 16 opposite the surface on which the base sheet 11 and the design layer 14 are laminated. Known materials having heat-sensitive or pressure-sensitive adhesive properties can be used as the backer sheet adhesive layer. The backer sheet adhesive layer can be formed to a thickness of, for example, 1 μm to 10 μm.

[0061] The decorative sheet 10 preferably has an Erichsen value measured by the Erichsen test method of 12.0 mm or more and 14.9 mm or less, more preferably 12.4 mm or more and 14.3 mm or less, and even more preferably 12.7 mm or more and 14.3 mm or less. An Erichsen value of 12.0 mm or more provides good bendability, and an Erichsen value of 12.4 mm or more provides excellent formability. Furthermore, an Erichsen value of 12.7 mm or more provides good trimmability. An Erichsen value of 14.9 mm or less provides the strength required for processing. An Erichsen value of 14.3 mm or less provides good durability. The Erichsen value of the decorative sheet 10 can be adjusted mainly by the material constituting the base sheet 11, the thickness of the base sheet 11, the materials constituting the matte layer and matte pattern layer (type of resin, NCO / OH ratio), the thickness of the matte layer and matte pattern layer, and the contents of the first matte material and the second matte material. Furthermore, when layers other than the base sheet 10, the matte layer 11, and the matte pattern layer 12 are provided, the thickness can also be adjusted by the materials constituting these layers, their thickness, etc. In this specification, the Erichsen test method refers to a test in which a decorative sheet (dimensions: 70 mm x 70 mm) is pressed into the base sheet side with a spherical punch (diameter: 20 mm) using an Erichsen tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) at a moving speed of 12 mm / min, and the Erichsen value refers to the penetration depth of the punch at which microcracks occur in the decorative sheet in the Erichsen test method.

[0062] Next, an outline of a method for manufacturing the decorated molded article 20 according to the first embodiment of the present invention will be described with reference to FIG.

[0063] [Method for manufacturing the decorative sheet] A method for manufacturing the decorative sheet 10 will now be described. First, a sheet having a glass transition temperature of 80 to 110°C and a thickness of 75 to 125 μm is prepared as the base sheet 11. The above-mentioned thermoplastic resins can be used for the base sheet.

[0064] Next, a matte layer 12 is formed on the base sheet 11. To form the matte layer 12, a first matte material is mixed with a first binder resin. As described above, a two-component curing urethane resin is used for the first binder resin, and isocyanate and polyol are blended so that the NCO / OH ratio is 1.1 to 2.0. An ink is obtained by mixing the first binder resin and the first matte material. This mixture is layered on the base sheet 11 to form the matte layer 12. The matte layer 12 can be formed by a conventional printing method such as gravure printing, screen printing, or offset printing, or a coating method such as gravure coating, roll coating, or die coating.

[0065] Next, a matte pattern layer 13 is partially laminated on the matte layer 12. To form the matte pattern layer 13, a second matte material is mixed into a second binder resin. As described above, a two-component curing urethane resin is used for the second binder resin, and isocyanate and polyol are blended so that the NCO / OH ratio is 1.1 to 2.0. The ink containing the second binder resin and the second matte material may be laminated using a known printing method or coating method, similar to the matte layer 12. By forming the matte pattern layer 13 and matte layer 12, which form the outermost surface of the decorative sheet, from a urethane resin, the surface of the decorative sheet can be made to feel soft to the touch.

[0066] Next, a design layer 14 is formed on the surface of the base sheet 11 opposite to the surface on which the matte layer 12 is formed. To form the design layer, a known binder resin and colorant are mixed and laminated by a known printing method or coating method. The design layer 14 may be formed by directly printing on the base sheet 11, or by laminating a sheet on which a design is printed onto the base sheet 11.

[0067] Next, an adhesive layer 15 is formed on the pattern layer 14. As the adhesive layer 15, a heat-sensitive adhesive or a pressure-sensitive adhesive is laminated on the matte pattern layer 13 and the pattern layer 14.

[0068] Next, a backer sheet 16 is formed on the adhesive layer 15. The sheet used as the backer sheet 16 is laminated on the adhesive layer 15.

[0069] In this way, the decorative sheet 10 is prepared.

[0070] [Method of Manufacturing Decorative Molded Product] A method of manufacturing the decorative molded product 20 will be described with reference to FIG. 4 . First, the decorative sheet 10 is placed on a jig 72 and preheated using a heat source 71 (see FIG. 4( a)). Examples of the heat source 71 include an infrared heater, an electric heater, high-frequency induction, a halogen lamp, microwaves, high-temperature induction such as steam, and a laser. The temperature of the heat applied to the decorative sheet 10 by the heat source 71 can be 100 to 250°C. Next, the decorative sheet 10 softened by heating is brought into close contact with the jig 72 and shaped (see FIG. 4( b)). Examples of methods for bringing the decorative sheet 10 into close contact include sucking air between the decorative sheet 10 and the jig 72 through suction holes (not shown) in the jig 72, or blowing compressed air from the decorative sheet 10 side to bring the decorative sheet 10 into close contact with the jig 72. Next, unnecessary portions of the decorative sheet 10 are trimmed (see FIG. 4( c)). This allows for the production of a decorative sheet 10 shaped to the outer surface of the decorative molded article. The trimmed decorative sheet 10 is placed with the matte pattern layer 13 facing the cavity surface of the first mold 81, and the decorative sheet 10 is fixed in place by, for example, sucking air through suction holes (not shown) provided in the first mold 81 (see FIG. 4(d)). Next, the first mold 81 and the second mold 82 are clamped together to form a cavity between the first mold and the second mold. Molten resin is injected into the cavity through a gate 83 to form a resin molded body 21, and at the same time, the resin molded body 21 and the surface of the decorative sheet 10 facing the backer sheet 16 are fixed together (see FIG. 4(e)). The same resin as used for the resin molded body 21 described above can be used as the molten resin. The mold is then opened, and the decorative molded article 20, in which the decorative sheet 10 and the resin molded body 21 are integrated, is removed (see FIG. 4(f)).

[0071] In the above-described manufacturing method, the decorative sheet 10 is shaped by adhering it to the jig 72 and then trimmed before injection molding. However, trimming of the decorative sheet 10 may be performed after injection molding. In this case, the decorative sheet 10 is shaped by adhering it to the molding surface of the first mold 81, and a resin molded product in which the decorative sheet 10 and the resin molded body 21 are integrated by injection molding is removed, and the unnecessary portion of the decorative sheet is trimmed. To adhere the decorative sheet 10 to the molding surface of the first mold 81, air may be sucked between the decorative sheet 10 and the molding surface through suction holes provided in the first mold 81. In the above-described manufacturing method, the gate 83 is located in the second mold 82. However, the gate 83 may also be located in the first mold. The decorative sheet 10 may be located on either the cavity surface of the first mold 81 or the second mold 82.

[0072] Example 1: A base sheet was prepared consisting of an acrylic resin sheet (glass transition temperature: 90°C, thickness: 75 μm) containing acrylic resin with added rubber particles. A design layer (thickness: 2-5 μm) consisting of an acrylic resin / vinyl chloride-vinyl acetate copolymer, an adhesive layer (thickness: 2-5 μm) consisting of a vinyl chloride-vinyl acetate copolymer, and a backer sheet (thickness: 430 μm) consisting of an ABS resin were laminated on one side of the base sheet in this order. A two-component curing urethane resin (acrylic polyol, meta-xylene diisocyanate) was blended as the first binder resin to an NCO / OH ratio of 1.1, and silica (average particle size: 4 μm) was mixed as the first matting agent in an amount of 50 parts by weight per 100 parts by weight of the first binder resin. The resulting mixture was laminated on the base sheet by gravure printing to form a matte layer. Next, a two-component curing urethane resin (acrylic polyol, metaxylene diisocyanate) was blended as the second binder resin so that the NCO / OH ratio was 1.1, and 12 parts by mass of acrylic resin (average particle diameter: 20 μm) was mixed as the second matting agent for every 100 parts by mass of the second binder resin. A matte pattern layer was partially formed on the matte layer by gravure printing. In this way, a decorative sheet having the layer structure shown in Figure 3 was produced. The Erichsen value of the decorative sheet of Example 1 was 13.6 mm.

[0073] (Examples 2 to 6 and Comparative Examples 1 to 5) Decorative sheets having the layer structure shown in Fig. 3 were produced in the same manner as in Example 1 under the production conditions shown in Table 1. The Erichsen values ​​of the decorative sheets obtained in the examples and comparative examples were measured.

[0074]

[0075] The decorative sheets obtained in the examples and comparative examples were subjected to the following tests to evaluate formability and chemical resistance. The results are shown in Tables 2 and 3 below.

[0076] (Forming ability) The decorative sheet was heated at 120 to 150°C, fitted into a jig and shaped. Those that could be shaped over the entire temperature range were marked with a ◎, those that could be shaped only under specific temperature conditions were marked with a ○, and those that could not be shaped were marked with an ×.

[0077] (Trimming ability) The decorative sheet was trimmed using a trimming mold heated to room temperature or 50° C. The decorative sheet that did not crack when using the room temperature trimming mold was evaluated as ⊚, the decorative sheet that cracked at room temperature but not when using a mold heated to 50° C was evaluated as ◯, and the decorative sheet that cracked even when using a mold heated to 50° C was evaluated as ×.

[0078] (Whether or not cracks occurred during shaping) The trimmed decorative sheet was set in a decorative molding die heated to room temperature or 50° C. If the decorative sheet did not crack in the die at room temperature, it was marked with an ⊚, if it cracked at room temperature but not in a die heated to 50° C, it was marked with an ◯, and if it cracked even in a die heated to 50° C, it was marked with an ×.

[0079] (Design of Decorated Molded Product) The decorative sheet was used for injection molding, and the decorative molded product was visually inspected for wrinkles and cracks. Those without abnormalities were marked with ◯, and those with wrinkles or cracks were marked with ×.

[0080] (Chemical resistance) Alcohol, hand cream, and sun lotion were applied to the decorative sheet (amount 2g / 1000mm). ２), and left to stand at 80°C for 24 hours. After standing, the decorative sheet was subjected to an adhesion test and an appearance test. - Adhesion test: A cross-cut test (checkerboard test) (JIS-K5600) was carried out, and those that did not peel off with the adhesive tape were rated as ◯, and those that peeled off were rated as ×. - Appearance test: Those that showed no abnormalities in the appearance of the decorative sheet were rated as ⊚, those that showed almost no abnormalities although there may have been traces of the coating remaining were rated as ◯, and those that showed discoloration due to the coating were rated as ×.

[0081]

[0082]

[0083] As can be seen from Table 2, in Examples 1 to 6, the evaluations of formability, trimming ability, cracking during shaping, and design of injection-molded products were all rated as ◯ or ◎, indicating good formability. In addition, the evaluations of chemical resistance were all rated as ◯ or ◎, indicating excellent chemical resistance. In particular, the decorative sheets of Examples 1 and 3 to 6 showed excellent trimming ability. In contrast, in Comparative Examples 1 to 5, the evaluations of formability, trimming ability, cracking during shaping, design of injection-molded products, and chemical resistance were all rated as ×.

[0084] In the decorated molded product according to the first embodiment described above, a pattern layer, an adhesive layer, and a backer sheet are formed on a base sheet, but it is sufficient that a matte layer and a matte pattern layer are formed on the decorated molded product; it is not necessary to form a pattern layer, an adhesive layer, and a backer sheet.

[0085] Although the decorated molded product according to the first embodiment is manufactured by simultaneously molding the resin molded body 21 and laminating the decorative sheet 10, these steps may be performed separately. That is, a preformed decorative sheet 10 may be attached to the molded resin molded body 21.

[0086] REFERENCE SIGNS LIST 10 Decorative sheet, 11 Base sheet, 12 Matte layer, 13 Matte pattern layer, 20 Decorative molded product, 21 Resin molded body, 81 First mold, 82 Second mold

Claims

1. A decorative sheet comprising: a base sheet having a glass transition temperature of 80 to 110°C and a thickness of 75 to 125 μm; a matte layer formed on said base sheet; and a matte pattern layer formed on said matte layer, wherein said matte layer comprises a first binder resin and a first matting material, and said matte pattern layer comprises a second binder resin and a second matting material, and said first binder resin and said second binder resin are two-component curing urethane resins that are cured products of polyol and an isocyanate-based curing agent, and the ratio (NCO / OH) of isocyanate groups in said isocyanate-based curing agent to hydroxyl groups in said polyol is 1.1 to 2.

0.

2. The decorative sheet according to claim 1, wherein the first matting material is inorganic particles, and the second matting material contains inorganic particles.

3. The decorative sheet according to claim 1 or 2, wherein the base sheet contains an acrylic resin.

4. The decorative sheet according to claim 3, having an Erichsen value of 12.0 to 14.9 mm.

5. A decorated molded product comprising: a resin molded body; a base sheet formed on the resin molded body, the base sheet having a glass transition temperature of 80 to 110°C and a thickness of 75 to 125 μm; a matte layer formed on the base sheet; and a matte pattern layer formed on the matte layer, wherein the matte layer comprises a first binder resin and a first matte material, and the matte pattern layer comprises a second binder resin and a second matte material, and the first binder resin and the second binder resin are two-component curing urethane resins that are cured products of polyol and an isocyanate-based curing agent, and the ratio (NCO / OH) of isocyanate groups in the isocyanate-based curing agent to hydroxyl groups in the polyol is 1.1 to 2.

0.

6. A decorative sheet comprising: a base sheet having a glass transition temperature of 80-110°C and a thickness of 75-125 μm; a matte layer formed on the base sheet; and a matte pattern layer formed on the matte layer, wherein the matte layer comprises a first binder resin and a first matte material, and the matte pattern layer comprises a second binder resin and a second matte material, the first binder resin and the second binder resin being two-component curing urethane resins that are cured products of polyol and an isocyanate-based curing agent, and the ratio (NCO / OH) of the isocyanate groups in the isocyanate-based curing agent to the hydroxyl groups in the polyol is 1.1-2.0; a process of placing the decorative sheet on the cavity surface of the first mold or the second mold of an injection molding die having a first mold and a second mold that forms a cavity between the first mold and the second mold by clamping; and a process of clamping the injection molding die. A method for manufacturing a decorated molded product, comprising: a step of injecting molten resin into the cavity to form a resin molded body, and simultaneously fixing the decorative sheet to the surface of the resin molded body; and a step of opening the injection molding die and removing the resin molded body.

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