JP2018069507A - Decorative molded article and decorative film for transfer - Google Patents

Abstract

An object of the present invention is to provide a good decorative molded article by suppressing discoloration of an adhesive layer in a light transmission region and suppressing interlaminar fracture due to adhesive adhesion. A decorative molded product 40 in which a transfer layer 17 having a light transmission region 51 through which light can be transmitted is formed on the surface of a molding resin 18 is provided. The transfer layer 17 includes a decoration layer 15 and an adhesive layer 16 that joins the decoration layer 15 and the molding resin 18. The adhesive layer 16 includes a first adhesive layer 34 formed of a first adhesive and a second adhesive layer 35 formed of a second adhesive. The first adhesive has higher adhesion to the decorative layer 15 and the molding resin 18 than the second adhesive. The second adhesive is less likely to discolor with heat than the first adhesive. The adhesive layer 16 in the light transmission region 51 is composed of the second adhesive layer 35. The adhesive layer 16 in the region other than the light transmission region 51 is configured by the first adhesive layer 34 or the second adhesive layer 35. [Selection] Figure 2

Description

  The present invention relates to an in-mold decorative molded product used for home appliances and automobile interior parts, and an in-mold transfer decorative film used for manufacturing the decorative molded product.

  Conventionally, as one of surface decoration methods for resin molded products, there is a film-in-mold method in which a transfer layer having a design printed on a substrate is transferred to the surface of the molded product simultaneously with injection molding (see, for example, Patent Document 1). ). FIG. 7 is a view showing a cross-sectional structure of the conventional decorative molded product 40 and the decorative film for transfer 20 described in Patent Document 1. As shown in FIG. The decorative film for transfer 20 includes a transfer layer 17 and a carrier film 19 as shown in FIG.

  The carrier film 19 includes a base material 11 (also referred to as a base film) and a release layer 12 formed on the base material 11. The transfer layer 17 is formed by laminating a surface protective layer 13, a primer layer 14, a decoration layer 15, and an adhesive layer 16 in this order. The transfer layer 17 is transferred onto the surface of the injection molding resin 18 simultaneously with the injection molding to form a decorative molded product 40.

  The surface protective layer 13 is made of a hard coat material or a clear coat material, becomes the outermost surface of the decorative molded product 40, and protects the inner layer of the surface protective layer 13 from scratches, foreign object adhesion, and the like. The primer layer 14 ensures interlayer adhesion between the surface protective layer 13 and the decorative layer 15. The primer layer 14 has a function of adsorbing or fixing the ink in the decoration layer 15. When the ink in the decoration layer 15 can be directly bonded to the surface protective layer 13, the primer layer 14 is not necessary. The decorative layer 15 decorates the decorative molded product 40, and can take various layer configurations from a single layer to a plurality of layers depending on the pattern or design desired to be imparted. The adhesive layer 16 plays a role for bonding the decoration layer 15 and the molding resin 18 and a role for protecting the ink in the decoration layer 15 from being washed away by the molding resin 18 injected at a high temperature and high pressure. Is.

  8A to 8D are diagrams showing a general in-mold molding method. In FIG. 8A, the decorative film for transfer 20 on which a design and a pattern have been applied is drawn out from a housing (not shown) and the movable mold 101 is placed with the transfer layer 17 side facing the fixed mold 102. Supplied between the fixed mold 102. The carrier film 19 faces the movable mold 101 side.

  In FIG. 8B, the decorative film for transfer 20 is adsorbed along the surface of the movable mold 101 by vacuum adsorption. Thereafter, the movable mold 101 is moved and clamped with the fixed mold 102, and a cavity space 103 is formed between the transfer layer 17 and the surface of the fixed mold 102.

  8C, the molten molding resin 18 is injected into the cavity space 103 (see FIG. 8B) from the injection port 41 of the fixed mold 102 toward the transfer layer 17 at high temperature and high pressure. The molding resin 18 is bonded to the transfer layer 17.

  8D, after the movable mold 101 and the fixed mold 102 are cooled to solidify the molding resin 18, the movable mold 101 is opened from the fixed mold 102 to take out the cooled decorative molded product 40. At this time, the transfer layer 17 is peeled off from the carrier film 19. The surface protective layer 13 (see FIG. 7) is the outermost surface of the decorative molded product 40. Thereby, the decorative molded product 40 in which the transfer layer 17 and the molding resin 18 are integrated is obtained.

JP 2011-213022 A

  Incidentally, some decorative molded products used for automobile interior parts and household electrical appliances have a design having a light transmission region through which light can be transmitted. For example, it is used for a cover lens of a display audio panel in an automobile interior part, and it shows an LED on the back side of a decorative molded product so as to transmit through a liquid crystal display on the back side or to emit characters for night illumination. Some of them are arranged to transmit light emitted from the LED through the transfer layer to show a light emission pattern.

  In particular, decorative molded products for automobile interior use are often exposed to a high temperature storage environment, and those that do not discolor even under such a high temperature storage environment so as not to cause quality deterioration in appearance. It has been demanded. Usually, the material of the adhesive layer is a mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer. However, the vinyl chloride-vinyl acetate copolymer has a characteristic of yellowing by heat.

  If the decorative molded product does not have a light transmission region, if the decorative layer contains a concealing layer that does not discolor due to heat, the discoloration of the adhesive layer cannot be seen from the surface side of the decorative molded product. However, in a decorative molded product having a light transmission region, since the transmitted light picks up the discoloration of the adhesive layer through the light transmission region, it is recognized as an appearance defect.

  If the component of the vinyl chloride-vinyl acetate copolymer is removed so that the adhesive layer does not turn yellow, the adhesion to the molding resin and the decorative layer is lowered. If an adhesive layer with low adhesion to the molding resin or the decorative layer is used, there is a risk of interlayer breakage between the injection molding resin and the adhesive layer or between the adhesive layer and the decorative layer. . When interlaminar fracture occurs, the transfer layer does not remain on the surface of the decorative molded product, resulting in poor appearance and cannot be used as a decorative molded product.

  As described above, in the conventional configuration, there is a problem that it is difficult to achieve both the prevention of discoloration of the adhesive layer in the light transmission region and the prevention of interlayer breakage due to the adhesiveness of the adhesive. It was.

  The present invention solves the above-mentioned conventional problems, and suppresses discoloration of the adhesive layer in the light transmission region and suppresses interlaminar fracture due to adhesive adhesion, thereby improving the appearance quality. The purpose is to provide a decorative molded product.

  In order to achieve the above object, the decorative molded product of the present invention is a decorative molded product in which a transfer layer having a light transmission region capable of transmitting light is formed on the surface of a molding resin, and the transfer layer is A decorative layer; and an adhesive layer that joins the decorative layer and the molding resin. The adhesive layer includes a first adhesive layer formed of a first adhesive and a second adhesive. The first adhesive has a higher adhesion to the decorative layer and the molding resin than the second adhesive, and the second adhesive Is more difficult to discolor with heat than the first adhesive, and the first adhesive layer and the second adhesive layer are provided between the decorative layer and the molding resin, respectively, and the light The adhesive layer in the transmission region is composed of the second adhesive layer, and the adhesive in the region other than the light transmission region It is characterized by being composed of the first adhesive layer or the second adhesive layer.

  According to the decorative molded product of the present invention, the adhesive layer includes the first adhesive layer formed of the first adhesive whose adhesion to the decorative layer and the molding resin is higher than that of the second adhesive. Therefore, compared with the case where an adhesive layer is comprised only with the 2nd adhesive bond layer formed with the 2nd adhesive agent, the adhesiveness can be improved and, by extension, interlayer destruction is suppressed. Is possible. Furthermore, since the adhesive layer in the light transmission region is composed of the second adhesive layer formed of the second adhesive that is less likely to be discolored by heat than the first adhesive, the adhesive layer is the first adhesive layer. Compared to the case where only the adhesive layer is used, discoloration of the adhesive layer in the light transmission region can be suppressed. Therefore, a decorative molded product with good appearance quality can be obtained.

It is a figure which shows the cross section of the decorating film for transcription | transfer in embodiment of this invention. It is a figure which shows the cross section of the decorative molded product in embodiment of this invention. It is a figure which shows the external appearance of the decorative molded product in embodiment of this invention. It is a figure which shows the filling state of the molding resin in a corner | angular part. It is a figure which shows the stress which generate | occur | produces in each layer of the decorative film for transcription | transfer pushed in with the filling pressure of molding resin. It is a figure which shows the filling state of the molding resin in an inclination part. It is a figure which shows the cross section of the conventional decorative molded product described in patent document 1, and the decorative film for transcription | transfer. It is a figure which shows the process of in-mold shaping | molding. It is a figure which shows the process of in-mold shaping | molding. It is a figure which shows the process of in-mold shaping | molding. It is a figure which shows the process of in-mold shaping | molding.

(Decoration film for transfer)
First, the decorative film for transfer in the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a cross section of a decorative film for transfer 20 in an embodiment of the present invention. The transfer decorative film 20 includes a transfer layer 17 and a carrier film 19. The carrier film 19 includes a base material 11 and a release layer 12 formed on the base material 11. The transfer layer 17 includes a surface protective layer 13, a primer layer 14 formed on the surface protective layer 13, a decoration layer 15 formed on the primer layer 14, and an adhesive layer 16 formed on the decoration layer 15. It consists of.

  As the base material 11, a polyethylene terephthalate (PET) film is mainly used, but a polycarbonate (PC, Poly Carbonate) or an oriented polypropylene (OPP, Oriented Polypropylene) may be used. The thickness of the substrate 11 is preferably 10 μm or more and 200 μm or less, and more preferably 20 μm or more and 100 μm or less. When the thickness is less than 10 μm, the substrate 11 is easily broken when stretched, and when it exceeds 200 μm, the substrate film is difficult to be deformed.

  The release layer 12 is composed of melamine resin, silicon resin, or the like. The thickness of the release layer 12 is not less than 0.5 μm and not more than 5 μm, for example. The surface protective layer 13 is a layer that becomes the outermost surface when the transfer layer 17 is transferred to the molding resin. Further, the surface protective layer 13 is made of a high hardness ultraviolet curable resin or the like. The thickness of the surface protective layer 13 is, for example, 1 μm or more and 10 μm or less.

  The primer layer 14 is a layer that joins the surface protective layer 13 and the decorative layer 15, that is, improves the adhesion between the surface protective layer 13 and the decorative layer 15. The primer layer 14 is made of a polyester resin or the like. The thickness of the primer layer 14 is, for example, not less than 1 μm and not more than 10 μm. The release layer 12, the surface protective layer 13, and the primer layer 14 are formed by a coating method such as gravure coating or slit die coating.

  In the present embodiment, the decoration layer 15 includes a surface decoration layer 31, a masking layer 32, and a light transmission layer 33. Hereinafter, a method for forming the decorative layer 15 will be described. First, the surface decoration layer 31 is printed on the primer layer 14. At this time, the surface decoration layer 31 is not printed on the entire surface of the primer layer 14, and the surface decoration layer 31 is not printed on the light transmission region 51 and the light non-transmission region 52 of the transfer layer 17. Reference numeral 37 denotes an area where the surface decoration layer 31 is not printed. The surface decoration layer 31 is formed of an ink having low light transmittance, and constitutes a background of a pattern or a pattern to be applied, for example. Details of the light transmission region 51 and the light non-transmission region 52 will be described later.

  Next, the light transmission layer 33 is printed in the region 37 where the surface decoration layer 31 on the primer layer 14 is not printed in the light transmission region 51 and the light non-transmission region 52. The light transmissive layer 33 is formed of an ink having a light transmissive property (high light transmissive property). At this time, when the light transmissive layer 33 printed on the light transmissive region 51 and the light transmissive layer 33 printed on the light non-transmissive region 52 are formed of the same ink, they are formed by one printing. However, when it is formed with inks having different colors and light transmittances, it is formed by two or more printings.

  Here, the light transmission layer 33 is preferably printed so as to protrude from the region 37 where the surface decoration layer 31 on the primer layer 14 is not printed and partially overlap the surface decoration layer 31. This is because the light transmission layer 33 is reliably formed in the region 37 even if a printing error occurs. The dimension that the light transmission layer 33 protrudes 31 from the surface decoration layer is set, for example, in the range of 0.2 mm to 1.0 mm. Reference numeral 38 denotes an area where the light transmission layer 33 is printed.

  After the light transmission layer 33 is printed, the masking layer 32 is further printed. At this time, the shielding layer 32 is not printed in the light transmission region 51, and the shielding layer 32 is printed in other regions including the light non-transmission region 52. The masking layer 32 has a function of blocking light, and is formed with an ink having a low light transmittance and a thickness. Further, it is preferable that the concealing layer 32 is printed so as to protrude into the region 38 where the light transmitting layer 33 formed in the light transmitting region 51 is printed and partially overlap the light transmitting layer 33. The reason will be described below.

  When printing the concealing layer 32 without protruding into the light transmissive layer 33 formed in the light transmissive region 51, a region where neither the light transmissive layer 33 nor the concealing layer 32 is printed is generated due to a printing error of the concealing layer 32. If there is a pinhole such as ink loss in the surface decoration layer 31 in that region, light is transmitted through the pinhole. That is, light leakage occurs in an unintended area. Therefore, it is preferable to print the concealment layer 32 so as to overlap the light transmission layer 33 formed in the light transmission region 51 so that such light leakage does not occur even if there is a printing error. Here, the dimension that the concealing layer 32 protrudes from the light transmission layer 33 is set in a range of 0.2 mm or more and 0.5 mm or less, for example. It is necessary to prevent the shielding layer 32 from protruding into the light transmission region 51. Reference numeral 39 denotes an area where the concealing layer 32 is not printed.

  The ink for forming the concealing layer 32 is, for example, black ink whose main material is carbon black. Further, in order to increase the concealment property (lower the light transmission property), printing may be repeated a plurality of times. However, depending on the color of the surface decoration layer 31, it is not limited to black ink, and may be silver metallic ink mainly made of aluminum filler or white ink mainly made of titanium oxide.

  After the masking layer 32 is formed, the first adhesive layer 34 is printed. However, the first adhesive layer 34 is not printed in the light transmission region 51. The area 36 where the first adhesive layer 34 is not printed is larger than the area 37 where the surface decoration layer 31 is not printed, preferably larger than the area 39 where the concealing layer 32 is not printed, and more preferably, the light transmission layer 33 is printed. It is larger than the area 38. The material of the first adhesive layer 34 will be described later.

  After the first adhesive layer 34 is formed, the second adhesive layer 35 is printed in the region 36 where the first adhesive layer 34 is not printed. A region 39 where the concealing layer 32 is not printed and a region 36 where the first adhesive layer 34 is not printed are recessed, and the second adhesive layer 35 is filled in the recess. The second adhesive layer 35 is preferably printed such that it protrudes from the region 36 where the first adhesive layer 34 is not printed and partly overlaps the first adhesive layer 34. This is because even if a printing error occurs, the second adhesive layer 35 is surely filled in the recess. The dimension by which the second adhesive layer 35 protrudes from the first adhesive layer 34 is set, for example, in the range of 0.2 mm to 1.0 mm. The material of the second adhesive layer 35 will be described later.

  The surface decoration layer 31, the hiding layer 32, the light transmission layer 33, the first adhesive layer 34, and the second adhesive layer 35 are formed by a printing method such as gravure printing, screen printing, offset printing, and flexographic printing, respectively. Is done. Here, in the case of a design that requires high concealability, the concealment layer 32 is formed thick in order to reduce the transmittance. Thereby, the dent of the area | region 39 where the concealing layer 32 is not printed becomes deep. In this recess, a recess in a region 36 where the first adhesive layer 34 is not printed is formed. The adhesive layer 16 needs to have a certain thickness or more in order to ensure its adhesiveness even when it becomes thin due to its elongation. Therefore, the recesses in the region 36 and the region 39 are deep, and the thickness of the second adhesive layer 35 filled in these recesses is increased. Therefore, when printing the second adhesive layer 35, it is preferable to employ screen printing that can easily form each layer even if there are irregularities, rather than gravure printing that tends to faint printing without high smoothness. In particular, when a thin pattern or design such as a character is given, the print quality can be stabilized by using the screen printing method.

  The ink materials of the surface decoration layer 31, the hiding layer 32, and the light transmission layer 33 constituting the decoration layer 15 are preferably composed mainly of the same kind of resin material. This is because by using a material mainly composed of the same kind of resin material, adhesion between the layers can be improved when forming each layer.

  Moreover, when forming each layer which comprises the decoration layer 15, it is preferable to form the next layer in the state which is not hardened | cured completely. When the next layer is formed after each layer is completely cured, the portion where the surface of the cured layer and the resin of the next layer are cured and reacted by chemical bonding decreases. Therefore, it is preferable to form each layer while maintaining a semi-cured state. However, if there are too many unreacted parts in a semi-cured state, the surface of each layer and the surface of the substrate may be blocked and the layer may be peeled off, so that blocking does not occur. It is important to maintain a dry state. For this reason, it is preferable to perform heat drying.

  Since there is a dent in the region where the second adhesive layer 35 is printed, the second adhesive layer can enter the dent, and can be in close contact with the side surfaces of the light transmission layer 33 and the concealing layer 32, and the adhesion area between the layers Can be increased. Therefore, the low adhesive force of the second adhesive layer 35 can be compensated.

  As described above, the decorative film for transfer 20 in the present embodiment is obtained. By performing in-mold molding using the decorative film for transfer 20, the decorative molded product in the present embodiment is obtained. Since the in-mold molding method is the same as the conventional in-mold molding method shown in FIGS. 8A to 8D, detailed description thereof is omitted.

(Decorated molded product)
Hereinafter, the decorative molded product in the present embodiment will be described with reference to the drawings. FIG. 2 is a view showing a cross section of the decorative molded product 40 according to the present embodiment. A light emitting unit 60 is provided on the side of the molded resin 18 of the decorative molded product 40, and light 61 emitted from the light emitting unit 60 is transmitted from the side of the molded resin 18 to the surface protective layer 13 side. The light emitting unit 60 is, for example, an LED, but if it is a single LED, it emits light like an eyeball. Therefore, a diffusion sheet or a light guide plate may be disposed between the LED and the molding resin 18 to serve as a surface light source.

  The light transmission region 51 is a region provided in the transfer layer 17, and the light 61 emitted from the light emitting unit 60 is not absorbed by the surface decoration layer 31 and the concealing layer 32, and is recognized as a light emission pattern through the light transmission layer 33. It is an area to be done. The light non-transmission region 52 is a region provided in the transfer layer 17 and does not transmit the light 61 of the light emitting unit 60 because the concealing layer 32 is formed, but the light transmission layer 33 is formed. It becomes a region that is recognized as a pattern or a pattern with a different color from the surroundings. The other area of the transfer layer 17 is an area recognized as the background of the pattern or design.

  FIG. 3 is a diagram (plan view) of the appearance of the decorative molded product 40 according to the present embodiment as viewed from the surface protective layer 13 (see FIG. 2) side. The dotted lines in FIG. 3 indicate the positions of the end portions of the inner light transmission layer 33 and the second adhesive layer 35 that cannot be seen from the outside. The light transmissive layer 33 is larger than the light transmissive region 51 visible from the outside, and the second adhesive layer 35 is printed larger than the light transmissive layer 33.

  As shown in FIGS. 2 and 3, in the light non-transmissive region 52, the light transmissive layer 33 is printed larger than the light transmissive region 51, but the light 61 emitted from the light emitting unit 60 is transmitted by the concealing layer 32. It will be cut off. With the configuration as described above, light from the light emitting portion is transmitted only in the light transmission region 51, and a predetermined light emission pattern can be expressed. The code | symbol 53 in FIG. 3 has shown the corner | angular part of a small curvature radius. The corner 53 is formed on the outer peripheral edge of the decorative molded product 40 over the surface direction and the thickness direction. The curvature radius appears in the cross-sectional direction of the corner portion 53. Details of the corner 53 will be described later.

  In the light transmission region 51, the light generated from the light emitting unit 60 passes through each layer until reaching the surface protective layer 13. Therefore, it is preferable that the material of each layer constituting the light transmission region 51 is such that the color and light transmittance of each layer are maintained in a predetermined state. When the color and light transmittance of each layer change, the emission color and emission luminance observed on the surface change. For this reason, a decorative molded product including a light emitting display unit for automobiles and a light emitting display unit for home appliances that require high appearance quality is required to have little change in light emission color and light emission luminance.

  Here, the cause of the change in color and light transmittance of each layer includes heat and ultraviolet heat. Therefore, the material of the surface protective layer 13, the primer layer 14, the light transmission layer 33, and the second adhesive layer 35 forming each layer has light resistance and heat resistance. As a material having light resistance and heat resistance, for example, a material containing an acrylic resin as a main component (for example, a content of 30% by mass or more) can be given. The ink material forming the decorative layer 15 is a material obtained by adding an inorganic pigment to an acrylic resin.

  Further, the molding resin 18 is also molded from a resin having optical transparency. As a specific material of the molding resin 18, a polycarbonate resin is generally used. However, the resin is not limited as long as it is a light-transmitting resin, and is not limited to ABS resin, a mixture of PC resin and ABS resin, PMMA. (Polymethyl methacrylate) resin, PP (polypropylene) resin, or the like may be used.

  The materials of the first adhesive layer 34 and the second adhesive layer 35 constituting the adhesive layer 16 are for joining the decorative layer 15 and the molding resin 18 and are in close contact with each other between these resin materials. It must have a sex. When the material of the decoration layer 15 is an acrylic resin and the molding resin 18 is a polycarbonate resin, an adhesive containing an acrylic resin and a vinyl chloride-vinyl acetate copolymer (hereinafter referred to as a first adhesive). May be used). The first adhesive has high adhesion to an acrylic resin or a polycarbonate resin due to the vinyl chloride-vinyl acetate copolymer component. However, the vinyl chloride-vinyl acetate copolymer has low heat resistance and is oxidized and yellowed when exposed to a high temperature environment for a long time.

  Examples of the adhesive that has high heat resistance and hardly discolors by heat include an adhesive containing an acrylic resin or a polyester resin (hereinafter sometimes referred to as a second adhesive). In this second adhesive, a vinyl chloride-vinyl acetate copolymer may not be contained at all, or may be contained in such a small amount that yellowing is not noticeable even when oxidized. However, this second adhesive has lower adhesion to the decorative layer 15 and the molding resin 18 than the first adhesive. Therefore, if the adhesive layer 16 is entirely composed of the second adhesive, sufficient adhesion to the decorative layer 15 and the molding resin 18 cannot be obtained, and the decorative layer 15 and the adhesive layer 16 or the adhesive layer 16 and the molding resin are not obtained. Interlaminar fracture of the transfer layer 17 occurs between the transfer layer 17 and the external appearance.

  According to the decorative molded product 40 in the present embodiment, the adhesive layer 16 is a first adhesive layer 34 formed of a first adhesive having high adhesion to the decorative layer 15 and the molding resin 18; Since both of the second adhesive layer 35 formed of the second adhesive having low adhesion to the decorative layer 15 and the molding resin 18 are included, the adhesive layer 16 is configured only by the second adhesive layer 35. Compared with the case, the adhesiveness can be improved, and as a result, the interlayer breakdown can be suppressed. Furthermore, since the adhesive layer 16 in the light transmission region 51 is composed of the second adhesive layer 35 formed of an adhesive that is less likely to be discolored by heat than the adhesive forming the first adhesive layer 34, Compared with the case where the adhesive layer 16 is composed of only the first adhesive layer 34, discoloration of the adhesive layer in the light transmission region 51 can be suppressed. Therefore, a decorative molded product 40 with good appearance quality can be obtained.

  Here, the contact area between the decoration layer 15 and the first adhesive layer 34 is preferably larger than the contact area between the decoration layer 15 and the second adhesive layer 35. Since the first adhesive layer 34 is formed of an adhesive having higher adhesion to the decorative layer 15 and the molding resin 18 than the second adhesive layer 35, the area on which the first adhesive layer 34 is printed. By making this larger than the area on which the second adhesive layer 35 is printed, the adhesion as a whole can be improved.

  Furthermore, when the decorative molded product 40 has a corner portion 53 having a small radius of curvature, the adhesive layer 16 at the corner portion 53 is preferably constituted by the first adhesive layer 34. The reason will be described below.

  FIG. 4 shows a cross-section of the filling state of the molding resin 18 injected at the time of in-mold molding at the corner 54 provided in the movable mold 101 to form the corner 53 of the decorative molded product 40. is there. Before the molding resin 18 is filled, the transfer decorative film 20 is adsorbed on the surface of the movable mold 101, but the tension of the transfer film 20 acts to follow the shape of the corner portion 54. It cannot be done and is in a state of floating from the movable mold 101. Then, when the molding resin 18 is filled, the transfer decorative film 20 is pushed into the corner portion 54 by the filling pressure 55 of the molding resin 18 acting on the transfer film 20. The corner portion 54 here has a radius of curvature of, for example, 1.0 mm or less. The shape of the corner 54 of the movable mold 101 is transferred to the decorative molded product 40, and the corner 53 of the decorative molded product 40 is formed as described above.

  FIG. 5 shows the stress generated in each layer of the decorative film for transfer 20 that is pushed in by the filling pressure 55 of the molding resin 18. In FIG. 5, the layer between the surface decoration layer 31 and the base material 11 is made of the same type of resin as the surface decoration layer 31, and may be considered as a behavior as the same layer, so that illustration is omitted. .

  The transfer decorative film 20 is expanded by the molding resin 18 until it follows the shape of the movable corner by the molding resin 18, and each layer constituting the transfer decorative film 20 is stretched. When the elongation characteristics of the resins constituting each layer are different, shear stress is generated between the layers. Interlayer stress 56 is generated between the stress 58 generated when the first adhesive layer 34 extends and the stress 57 generated when the concealing layer 32 extends. If the adhesive force in the shear direction between the layers is not higher than the stress 56, the transfer layer 17 may be destroyed between layers. That is, interlaminar fracture is particularly likely to occur at the corner 53 of the decorative molded product. Therefore, the adhesive layer in the corner 53 is preferably composed of the first adhesive layer 34 having higher adhesion to the decorative layer 15 and the molded resin 18 than the second adhesive layer.

  Further, as shown in FIG. 6, the transfer decorative film 20 is also lifted from the movable mold 101 by providing the movable mold 101 with the deep-drawn inclined portion 59, and the corner portion having the small curvature radius described above. Similar problems arise. Therefore, also in the decorative molded product to which the shape of the inclined portion 59 of the movable mold 101 is transferred, it is preferable that the adhesive layer of the inclined portion is composed of the first adhesive layer. Here, the inclined portion of the deep drawing is, for example, an inclination ratio (L / D) of 1.3 or more when the distance of the inclined surface is L and the projection distance is D.

  In addition, although the corner | angular part of the said small curvature radius and the inclined part of a deep drawing may be provided in the edge part of a decorative molded product, it is not restricted to this, Area | regions other than an edge part as a level | step difference of a decorative molded product surface May be provided. In addition, when the corners and slopes of these decorative molded products are provided in regions other than the light transmission region, the adhesive is used regardless of the radius of curvature of the corners and the slope ratio of the slopes. The layer is preferably composed of a first adhesive layer.

  The thickness of the first adhesive layer 34 is preferably 8 μm or more. The first adhesive layer 34 having a thickness of 8 μm or more is formed by screen printing of 225 mesh, for example. Since the first adhesive layer 34 is stretched by the molded resin 18 to be injected, if the first adhesive layer 34 does not have a certain thickness, the first adhesive layer 34 is broken in the layer and it is difficult to maintain a predetermined adhesion. If thickness is 8 micrometers or more, it will not become a problem with respect to elongation. When formed by 300-mesh screen printing, the thickness may be as thin as about 5 μm, and thus adhesion may not be maintained due to elongation.

  Further, the cured state of the surface decoration layer 31 and the hiding layer 32 also affects the adhesion with the adhesive layer. As the ink material for the surface decoration layer 31 and the masking layer 32, for example, a two-component curable ink is used, and the surface decoration layer 31 and the masking layer 32 are formed by adding a curing agent and thermally drying. The hardness and elongation characteristics (cured state) of the surface decoration layer 31 and the concealing layer 32 differ depending on the type of the curing agent added. The softening specification curing agent can give the surface decoration layer 31 and the hiding layer 32 more flexible than the normal (standard) curing agent. On the other hand, if the surface decoration layer 31 is formed by using a softening specification curing agent, the glossiness of the appearance is lowered, so that it is not appropriate in the case where an appearance like piano black that requires high gloss is required.

Table 1 shows adhesiveness of the adhesive layer to the decorative layer and the molding resin, thermal discoloration of the adhesive layer, and decoration in Reference Examples 1 to 6 in which the configurations of the surface decorative layer, the concealing layer, and the adhesive layer are changed. The appearance gloss of the molded product is evaluated according to the following criteria. In Table 1, as the surface decoration layer in Reference Examples 1 to 6, based on MIX-HF ink manufactured by Teikoku Ink Manufacturing Co., Ltd., acrylic resin is 60% by mass, carbon black is 20% by mass, and curing agent is 3% by mass. % Content was used. As the concealing layer, a layer containing 60% by mass of an acrylic resin, 20% by mass of carbon black, and 9% by mass of a curing agent was used. 210 curing agent was used as the curing agent (standard), and 200 curing agent was used as the curing agent (softening). As the first adhesive, one containing 15% by mass of an acrylic resin and 61% by mass of a vinyl chloride-vinyl acetate copolymer was used. As the second adhesive, one containing 16.7% by mass of a polyester resin was used. The thickness of the surface decoration layer was 5 μm, the thickness of the concealing layer was 8 μm, and the thickness of the adhesive layer was 8 μm.
(1) Adhesiveness When the peeling width of the transfer layer was 0.3 mm or less,
The peel width of the transfer layer was 0.3 mm or more and 0.5 mm or less as △,
The case where the peel width of the transfer layer was 0.5 mm or more was evaluated as x.
(2) Thermal discoloration As a result of leaving at 80 ° C. for 240 hours, no discoloration was visually confirmed, and ○
As a result of being allowed to stand for 240 hours at a temperature of 80 ° C., the color that was visually confirmed to be discolored was rated as x.
(3) Appearance Gloss When the reflected image was clear by visual inspection,
An image in which the reflected image was blurred visually was rated as x.

In Reference Examples 1, 2, 4, and 5 in which the curing agent for the surface decoration layer was a standard specification, the appearance gloss of the decorative molded product was good. Further, in Reference Examples 1 and 3 in which the curing agent of the concealing layer was softened and the adhesive layer was the first adhesive layer, the concealing layer was sufficiently flexible, so that the adhesion was good. In Reference Example 2 in which the curing agent of the concealing layer is a standard specification and the adhesive layer is the first adhesive layer, the adhesiveness is inferior to Reference Examples 1 and 3 because the concealing layer has insufficient flexibility. It was a thing.

  In Reference Examples 4 to 6, in which the adhesive layer was the second adhesive layer, the adhesion was insufficient regardless of the specifications of the curing agent for the concealing layer. Further, in Reference Examples 1 to 3 in which the adhesive layer is the first adhesive layer, the adhesive layer was discolored by the high temperature standing test, but in Reference Examples 4 to 6 in which the adhesive layer was the second adhesive layer, The discoloration of the adhesive layer was at a level with no problem.

  From the above, the decorative molded product having the light transmission region is formed to have the configuration of Reference Example 4 or 5 in the light transmission region and to the configuration of Reference Example 1 in the other regions. It is preferable. As a result, it is possible to obtain a decorative molded product that exhibits excellent overall adhesion, good appearance gloss, and little thermal discoloration in the light transmission region. If a high gloss appearance is not required, the configuration of Reference Example 3 may be used instead of Reference Example 1, and the configuration of Reference Example 6 may be used instead of Reference Example 4 or 5.

  The in-mold decorative molded product of the present invention has the effect of suppressing the discoloration of the adhesive layer in the light transmission region of the transfer layer of the decorative molded product and suppressing the interlaminar fracture due to the adhesiveness of the adhesive. In particular, it can be suitably used for decorative molded products used for automobile interior parts and household appliances.

DESCRIPTION OF SYMBOLS 11 Base material 12 Release layer 13 Surface protective layer 14 Primer layer 15 Decoration layer 16 Adhesive layer 17 Transfer layer 18 Molding resin 19 Carrier film 20 Decorating film for transfer 31 Surface decoration layer 32 Concealing layer 33 Light transmission layer 34 1st Adhesive layer 35 Second adhesive layer 40 Decorative molded product 51 Light transmitting region 52 Light non-transmissive region 53 Corner portion of decorative molded product 54 Movable corner portion 55 Filling pressure 56 Stress 57 Stress 58 Stress 59 Movable type Inclined part 101 Movable mold 102 Fixed mold

Claims (8)

A transfer layer having a light transmission region capable of transmitting light is a decorative molded product formed on the surface of the molding resin,
The transfer layer is
A decorative layer,
An adhesive layer that joins the decorative layer and the molding resin,
The adhesive layer is
A first adhesive layer formed of a first adhesive;
A second adhesive layer formed of a second adhesive,
The first adhesive has higher adhesion to the decorative layer and the molding resin than the second adhesive,
The second adhesive is less susceptible to discoloration by heat than the first adhesive,
The first adhesive layer and the second adhesive layer are provided between the decorative layer and the molding resin, respectively.
The adhesive layer in the light transmission region is composed of the second adhesive layer,
The decorative molded product, wherein the adhesive layer in a region other than the light transmission region is configured by the first adhesive layer or the second adhesive layer. The decorative molded product according to claim 1, wherein a contact area between the decoration layer and the first adhesive layer is larger than a contact area between the decoration layer and the second adhesive layer. The first adhesive contains an acrylic resin and a vinyl chloride-vinyl acetate copolymer,
The decorative molded article according to claim 1 or 2, wherein the second adhesive contains an acrylic resin or a polyester resin. The said 2nd adhesive bond layer is formed so that it may protrude from the said light transmission area | region, and a part may overlap with the said 1st adhesive bond layer. The decorative molded product described. A corner or inclined part is provided in a region other than the light transmission region,
The adhesive layer in the said corner | angular part or an inclination part is comprised by the said 1st adhesive bond layer. The decorative molded product of any one of Claims 1-4 characterized by the above-mentioned. The decorative layer is
A light transmissive layer that transmits light;
A concealing layer that blocks light,
The decorative layer in the light transmission region is composed of the light transmission layer,
The decorative molded product according to any one of claims 1 to 5, wherein the decorative layer in a region other than the light transmission region includes the concealing layer. The decorative layer further includes a surface decorative layer formed on the surface side of the concealing layer,
The decorative molded article according to claim 6, wherein the concealing layer has higher flexibility than the surface decoration layer. It is a decoration film for transcription | transfer used for manufacture of the decorative molded product of any one of Claims 1-7, Comprising: The transfer layer transcribe | transferred on the surface of the molding resin which comprises the said decorative molded product. A decorative film for transfer, which is formed on a substrate via a release layer.