Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/12—Reflex reflectors
  • G02B5/126—Reflex reflectors including curved refracting surface
  • G02B5/128—Reflex reflectors including curved refracting surface transparent spheres being embedded in matrix

Definitions

• One aspect of the present disclosure relates to a retroreflective film and a method for making the retroreflective film.
• Patent Document 1 describes a retroreflective sheet.
• the retroreflective sheet has a property that retroreflects incident light as it is directly toward a light source.
• the retroreflective sheet includes a top coat layer, a glass bead layer, an adhesive layer, and a backing paper in order from the front surface.
• the glass bead layer includes a plurality of glass beads arranged in a planar shape, a binder that is a synthetic resin filled between the glass beads, and a concave reflective film disposed on the lower side of the glass beads.
• Patent Document 2 describes a retroreflective colored article.
• the retroreflective colored article includes a barrier layer disposed over a backing layer and the thermoplastic layer, a polymeric color layer that covers the barrier layer and the plurality of beads, a reflective layer disposed over the polymeric color layer, and a bead bond layer that covers the reflective layer.
• Each of the plurality of beads is partially embedded in the thermoplastic layer between the barrier layers.
• retroreflective films looks in black or similar colors of low lightness at daytime and looks in colors other than black at nighttime.
• a moving body such as an automobile looks in black or similar colors of low lightness at daytime for improving the design, and reflects light emitted from a vehicle lighting fixture at nighttime for improving the safety.
• a retroreflective film in accordance with an aspect of the present disclosure has a plurality of layers, the plurality of layers including an adhesion layer to be adhered to an adherend, a retroreflective layer, a first colored layer, and a second colored layer having a lower lightness than the first colored layer in this order, and the retroreflective layer retroreflects at least a portion of light incident through the second colored layer and the first colored layer toward a light source of the light.
• a method for making a retroreflective film according to an aspect of the present disclosure includes preparing a retroreflective layer, forming a first colored layer on the retroreflective layer, and forming a second colored layer on the first colored layer, the second colored layer having a lower lightness than the first colored layer, and the retroreflective layer retroreflects at least a portion of light incident through the second colored layer and the first colored layer toward a light source of light.
• design and safety can be improved.
• FIG. 1 is a side view illustrating a portion of an exemplary automobile to which a retroreflective film in accordance with an embodiment is applied.
• FIG. 2 is a perspective view illustrating an exemplary automobile door to which the retroreflective film in accordance with the embodiment is applied.
• FIG. 3 is a view schematically illustrating a cross section of a retroreflective film in accordance with First embodiment.
• FIGS. 4A and 4B are view schematically illustrating steps of a method for making the retroreflective film in FIG. 3.
• FIG. 5A is a view schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Second embodiment.
• FIG. 5B is a view schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Third embodiment.
• FIG. 6A is a view schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Fourth embodiment.
• FIG. 6B is a view schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Fifth embodiment.
• FIGS. 7A and 7B are views schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Sixth Embodiment.
• FIGS. 8 A and 8B are views schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Seventh Embodiment.
• FIGS. 9A to 9D are views schematically illustrating steps of a method for making the retroreflective film in accordance with Eighth Embodiment.
• FIG. 10A is a view schematically illustrating a retroreflective film in accordance with Eighth embodiment.
• FIG. 10B is a view schematically illustrating a retroreflective film in accordance with Ninth embodiment.
• FIG. 11A and FIG. 1 IB are views schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Tenth Embodiment.
• FIG. 12A and FIG. 12B are views schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Eleventh Embodiment.
• FIGS. 13A to 13C are views schematically illustrating steps of a method for making the retroreflective film in accordance with Twelfth Embodiment.
• FIGS. 14A and 14B are views schematically illustrating the retroreflective film and steps of the method for making the retroreflective film in accordance with Twelfth Embodiment.
• FIG. 14C is a view schematically illustrating a retroreflective film in accordance with Thirteenth embodiment.
• FIGS. 15A and 15B are views schematically illustrating the retroreflective film and steps of the method for making the retroreflective film in accordance with Fourteenth Embodiment.
• FIGS. 16A and 16B are views schematically illustrating a retroreflective film and steps of a method for making the retroreflective film in accordance with Fifteenth Embodiment.
• FIGS. 17A to 17C are views schematically illustrating steps of a method for making the retroreflective film in accordance with Sixteenth Embodiment.
• FIGS. 18A and 18B are views schematically illustrating the retroreflective film and steps of the method for making the retroreflective film in accordance with Sixteenth Embodiment.
• FIG. 18C is a view schematically illustrating a retroreflective film in accordance with Seventeenth embodiment.
• “Retroreflective” indicates reflecting light in an opposite direction to a light incidence direction at incidence of the light. That is, “retroreflective” indicates retroreflecting at least a portion of the light emitted from the light source to return light black toward the light source.
• a “retroreflective layer” refers to a layered portion that performs retroreflection.
• a “colored layer” refers to a layer having a color.
• a “colored layer” includes, for example, a layer having a color as opaque, translucent, or colored transparent. The color may be either chromatic or achromatic. Note that the chromatic color and the achromatic color conform to the definition in JIS Z8102: 2001.
• Lightness is an indication of the brightness of the color, indicating that the color is closer to white as the lightness is higher, and is closer to black as the lightness is lower.
• Black includes not only black, but also colors that may be visibly recognized as black, and includes blackish blue, purple, brown, gray, and green of low lightness.
• Black may be a color having a hue or saturation, and may include a color having a predetermined lightness or less.
• Bead indicates a spherical body provided inside the retroreflective layer, and includes, for example, transparent microsphere bead.
• a “bead layer” indicates a layer including beads, for example, a layer that contact with at least a portion of the beads.
• An “adherend” refers to an object to which a retroreflective film is applied, and is a“moving body”, for example.
• A“moving body” is a body that moves, and includes transportation equipment such as vehicles, ships, aircrafts, and rockets, and moving machines such as blades of a wind power plant.
• a “Vehicle” includes drivable machines such as automobiles, bicycles, electric trains, and new trunk lines. The present disclosure describes an example in which a retroreflective film is applied to the vehicle.
• normal light indicates light that has various wavelengths and is emitted in various directions.
• the normal light indicates sunlight or light in environment where one is irradiated with light from general illumination.
• the linear light includes light that has various wavelengths, but has a high directionality in which the light-travelling direction is aligned to a certain level or more.
• the linear light indicates light emitted from the vehicle lighting fixture. Note that coherent light such as laser beam is also included in the linear light.
• environment irradiated with the normal light may be referred to as “under normal light” and environment irradiated with the linear light may be referred to as "under linear light”.
• FIG. 1 illustrates a vehicle body 1 of an automobile, which is an example of a vehicle to which the retroreflective film is applied.
• the vehicle body 1 has a side window 2, an A pillar 3, a B pillar 4, and a C pillar 5.
• the side window 2 is constituted of glass
• the A pillar 3, the B pillar 4, and the C pillar 5 are made of metal.
• the retroreflective film 10 may be applied to at least any one of the A pillar 3, the B pillar 4, and the C pillar 5, for example.
• the portion to which the retroreflective film 10 is applied looks in black when light is strong at daytime, and looks in a color having a higher lightness than black when irradiated with the linear light having a high directivity at nighttime.
• the "Daytime” indicates environment under normal light.
• the “Daytime” indicates, for example, environment under sunlight at daytime, or environment under general illumination.
• the "Nighttime” may indicate, for example, a period from sunset to sunrise on the next morning, or may indicate a dark state that requires any irradiation means.
• the "color having a higher lightness than black” may be yellow, green, or blue, and may further include colors other than yellow, green, and blue, such as red.
• the relation between the application position and color of the retroreflective fdm 10 of the vehicle body 1 conforms to the security standards for road transportation vehicles in each country.
• the retroreflective fdm 10 of a color other than white may be applied to a rear-facing portion of the vehicle body 1.
• the retroreflective fdm 10 of a color other than red may be applied to a front-facing portion of the vehicle body 1.
• the retroreflective fdm 10 of any color may be applied to the A pillar 3, the B pillar 4, and the C pillar 5 that constitute the side portion of the vehicle body 1.
• the retroreflective fdm 10 in accordance with the embodiment may be observed as a color that is close to black under normal light.
• the retroreflective fdm 10 in accordance with the embodiment is retroreflected even when waves in a wavelength band other than visible light emitted from a sensor including a millimeter wave radar or a Light Detection and Ranging (LIDAR) used in a vehicle or the like are incident thereon. This is suitable for ensuring safety.
• LIDAR Light Detection and Ranging
• FIG. 2 is a perspective view illustrating an exemplary door 6 of the vehicle body 1.
• the retroreflective fdm 10 may be applied to the door 6.
• the retroreflective fdm 10 is applied to the inner side of the door 6.
• the retroreflective fdm 10 faces to the rear of the vehicle body 1 when the door 6 is opened, the presence of the vehicle body 1 may be recognized by a vehicle behind due to shining of the retroreflective fdm 10.
• the retroreflective fdm 10 is applied to an outer edge 6d of an inner surface 6c of an outer panel 6b of the door 6.
• the retroreflective fdm 10 is applied to the outer edge 6d of the inner surface 6c of the outer panel 6b in this way, for example, opening of the door 6 can be recognized by the automobile behind due to shining of the retroreflective fdm 10 when irradiated with light from the vehicle light of the automobile behind at nighttime.
• the plurality of retroreflective fdms 10 may be applied to the outer edge 6d of the inner surface 6c of the outer panel 6b so as to be vertically arranged. Retroreflective fdms in accordance with other various embodiments will be described below.
• FIG. 3 is a view schematically illustrating a layered configuration of a retroreflective film 10 in accordance with First embodiment.
• a release liner 11 As illustrated in FIG. 3, in the retroreflective film 10, a release liner 11, an adhesive layer 12, a retroreflective layer 13, a clear layer 14, a first colored layer 15, and a second colored layer 16 are stacked in this order from a lower side (a side of an adherend for the retroreflective film 10).
• the release liner 11 is, for example, a mold release film peeled from the adhesive layer 12.
• the release liner 11 includes polymer or paper, for example. From the perspective of surface smoothness, the release liner 11 is preferably a polymer release liner. Examples of a release coating material of the release liner 11 include, but not limited to, a fluorine polymer, an acrylic resin, or a silicone.
• the adhesive layer 12 is an adhesion layer to be adhered to an adherend.
• the adhesive layer 12 includes, for example, an acrylic-based adhesive, a rubber-based adhesive, a silicone- based adhesive, or an acrylic foam agent, and may further include adhesive microparticles.
• the material for the adhesive layer 12 is not particularly limited.
• the retroreflective film 10 is applied by peeling off the release liner 11 and applying the adhesive layer 12 to the vehicle body 1 and the like.
• the retroreflective layer 13 includes a reflective layer 17 stacked on the adhesive layer 12, a space coat layer 18, a bead layer 19, and a bond layer 20.
• the reflective layer 17 is, for example, an aluminum deposited layer having deposited aluminum.
• the reflective layer 17 may be a silver deposited layer having deposited silver.
• the reflective layer 17 may be flat, or may be concave to cover each bead of the bead layer.
• the space coat layer 18 is, for example, a spacer layer defining a spacing between the reflective layer 17 and the bead layer 19.
• the space coat layer 18 defines a preferred spacing between the reflective layer 17 and each bead 19b in the bead layer 19 for retroreflecting light to the bead.
• the bead layer 19 is a layer including a plurality of beads 19b that are microspheres, and for example, the beads 19b are glass beads made of glass.
• the plurality of beads 19b are arranged in a lattice or staggered manner in the space coat layer 18, for example.
• the retroreflective layer 13 achieves retroreflection with high directionality.
• the bond layer 20 is a layer that covers the plurality of beads 19b of the bead layer 19, and is also referred to as a bead bond layer.
• the material for the bond layer 20 include urethane resin, acrylic resin, vinyl chloride resin, silicone resin, epoxy resin, fluororesin, melamine resin, alkyd resin, and mixtures thereof.
• the bond layer 20 is, for example, an uncolored, colorless, and transparent layer.
• the clear layer 14 may be, for example, a resin fdm or a resin sheet that is made of a transparent resin.
• the material for the clear layer 14 is not particularly limited, but is PVC (polyvinyl alcohol), for example.
• the thickness of the clear layer 14 is, for example, 3 pm or more and 500 pm or less, and may be 58 pm as an example, and may be changed as appropriate.
• the first colored layer 15 is, for example, a yellow colored layer.
• yellow includes not only pure yellows, but also yellowish colors such as yellow green and orange, meaning yellow in a broad sense.
• the first colored layer 15 may include, for example, a yellow pigment such as isoindoline-based pigment, a dispersing agent such as a wet dispersing agent, and a solvent.
• the material for the first colored layer 15 may include acrylic copolymer and ethylene glycol monobutyl ether.
• a thickness of the first colored layer 15 is, for example, 1 pm or more and 10 pm or less, and is 5 pm as one example.
• the second colored layer 16 is a layer colored with a color having lower lightness than the color of the first colored layer 15.
• the color of the second colored layer 16 is black.
• the second colored layer 16 may include a black pigment, a dispersant such as a wet dispersing agent, and a solvent.
• the material for the second colored layer 16 may include at least any one of polycaprolactone diol, isophorone diisocyanate, black acrylic resin, acrylic polymer, and methyl ethyl ketone.
• the proportion of the mass of polycaprolactone diol in the second colored layer 16 is 47% or more and 48% or less, and the proportion of the mass of isophorone diisocyanate in the second colored layer 16 is 42% or more and 43% or less, the proportion of the mass of the black acrylic resin in the second colored layer 16 is 1% or more and 5% or less, and the proportion of the mass of the acrylic polymer in the second colored layer 16 is 0% or more and 1% or less.
• a thickness of the second colored layer 16 is, for example, 10 pm or more and 50 pm or less, and may be 25 pm or more and 35 pm or less.
• a reflective sheet R1 in which the release liner 11, the adhesive layer 12, the retroreflective layer 13, and a clear layer 14 are stacked in advance is prepared (preparing a retroreflective layer).
• yellow liquid LI is coated on the clear layer 14 of the reflective sheet Rl, and the coated yellow liquid LI is dried to form the first colored layer 15 (forming the first colored layer).
• black liquid L2 is coated on the first colored layer 15, and the coated black liquid L2 is dried to form the second colored layer 16 (forming the second colored layer).
• the above-mentioned drying is performed by exposure at 80°C for 60 minutes, for example.
• the second colored layer 16 is formed on the first colored layer 15 in this manner to complete the retroreflective film 10.
• the second colored layer 16, the first colored layer 15, and the retroreflective layer 13 are stacked in this order from the side of the front layer, and the lightness of the color of the second colored layer 16 located on the side of the front layer is lower than the lightness of the color of the first colored layer 15 located on side of the retroreflective layer 13.
• the color of the first colored layer 15 is yellow and the color of the second colored layer 16 is black.
• the color of the second colored layer 16 located on the side of the front layer is visible when irradiated with normal light having a low directionality at daytime, improving design due to the color of low lightness.
• the retroreflective film 10 when irradiated with light XI, which is linear light having a high directivity at nighttime, the retroreflective film 10 retroreflects the chromatic light. Specifically, when irradiated with the light XI, the retroreflective layer 13 directs the reflected light X2 toward the opposite direction to the emission direction, and the reflected light X2 passes through the first colored layer 15 and the second colored layer 16. Thus, because of the high directionality of the reflected light X2 of the light XI at nighttime, the color having high lightness of the first colored layer 15 is visible at nighttime, improving design and safety due to the color having high lightness at nighttime.
• the retroreflective layer 13 may have the bead layer 19 that includes the plurality of beads 19b.
• the retroreflective layer 13 including the bead layer 19 can further suppress the appearance of the lattice shape. Therefore, the visibility of the retroreflective film 10 particularly at nighttime can be increased.
• the color of the second colored layer 16 may be black. In this case, when the retroreflective film 10 is viewed at daytime, the retroreflective film 10 looks black, improving design.
• the retroreflective coefficient of the reflected light X2 reflected by the retroreflective film 10 may be 0.3 (cd/lux/m 2 ) or more, 0.7 (cd/lux/m 2 ) or more, or 1.0 (cd/lux/m 2 ) or more.
• the retroreflective coefficient of the reflected light X2 from the retroreflective layer 13 at nighttime is 0.3 (cd/lux/m 2 ) or more, the amount of light of the reflected light X2 can be increased to enhance the color having high lightness, further improving design and safety.
• the retroreflective coefficient of the reflected light X2 reflected from the retroreflective film 10 may be 30 (cd/lux m 2 ) or less.
• the retroreflective coefficient (cd/lux m 2 ) is obtained by using the measurement method prescribed in JIS Z 9117 8.3 "Measurement of Retroreflective Material and Reflective Performance". Specifically, the retroreflective coefficient is obtained by measuring the retroreflective coefficient (retroreflective coefficient R0.2) at an observation angle of 0.2 degrees and an incidence angle of 5 degrees with a retroreflective measurement device Retrosign Type 4500 (Delta Light Optics, Lyngby, Denmark). In this case, the retroreflective coefficient is obtained by irradiating the retroreflective film with light of constant luminance from a light projector and measuring the luminance of light reflected back from the retroreflective film.
• the retroreflective film 10 may be applied to a moving body.
• the color having low lightness of the second colored layer 16 is visible at daytime, improving design of the moving body such as a vehicle.
• the color of high lightness of the first colored layer 15 is visible at nighttime, improving design and security of the moving body such as a vehicle.
• the moving body has lights on the front and back portions, but has no object emitting light at nighttime on the side portion.
• the retroreflective film 10 when the retroreflective film 10 is applied to the side portion of the moving body, the side portion can shine with color of high lightness at nighttime, improving safety and design. It is also conceivable to provide a light on the side portion of the moving body, but in this case, it is necessary to supply power to the light. However, power supply can be made unnecessary by applying the retroreflective film 10 to the side portion of the moving body.
• the black color of the retroreflective film 10 can be emphasized at daytime.
• the inner side of the side windows 2 of the vehicle body 1 can look wide, improving design of the vehicle body 1.
• the side portion of the vehicle body 1 can shine with color of high lightness of the first colored layer 15 at nighttime, contributing to an improvement of safety and design of the vehicle body 1.
• the retroreflective film 10 is attached to the inside of the door 6 of the vehicle body 1, the inside of the door 6 opened at nighttime can shine, avoiding the possibility that the vehicle behind and the like approaches the door 6 to further improve safety.
• the retroreflective film 10A in accordance with Second embodiment includes a second colored layer 16A that is thicker than the second colored layer 16 described above.
• the thickness of the second colored layer 16A is, for example, 50 pm or more and 100 pm or less, and may be 55 pm or more and 65 pm or less.
• a method for making the retroreflective film 10A is the same as the above-mentioned method for making the retroreflective film 10, and the thickness of the black liquid L2 coated on the first colored layer
• the retroreflective film 10A in accordance with Second embodiment has the same effects as those of the retroreflective film 10
• the retroreflective film 10B includes a second colored layer 26 having components that are different from the components of the second colored layer
• a thickness of the second colored layer 26 is, for example, 10 pm or more to 50 pm or less, and may be 25 pm or more and 35 pm or less.
• the second colored layer 26 includes the same components as the components of second colored layer 16, but the proportion of the components is different from that of the second colored layer 16.
• the proportion of the mass of polycaprolactone diol in the second colored layer 26 is 45% or more and 46% or less
• the proportion of the mass of the isophorone diisocyanate in the second colored layer 26 is 40% or more and 41% or less
• the proportion of the mass of the black acrylic resin in the second colored layer 26 is 5% or more and 7% or less
• the proportion of the mass of the acrylic polymer in the second colored layer 26 is 0% or more and 1% or less
• the proportion of the mass of methyl ethyl ketone in the second colored layer 26 is 7% or more and 8% or less.
• the proportion of the mass of the black acrylic resin in the second colored layer 26 is 5% or more and 7% or less, and is larger than the proportion of the mass of the black acrylic resin in the second colored layer 16 (1% or more and 5% or less).
• the proportion of the mass of the black acrylic resin in the second colored layer 16 is 5% or more and 7% or less, and is larger than the proportion of the mass of the black acrylic resin in the second colored layer 16 (1% or more and 5% or less).
• the retroreflective film IOC includes a third colored layer 27 instead of the bond layer 20 described above.
• the third colored layer 27 functions as, for example, a bond layer (bead bond layer) that covers the plurality of beads 19b of the bead layer 19.
• Examples of the material for the third colored layer 27 include urethane resin, acrylic resin, vinyl chloride resin, silicone resin, epoxy resin, fluororesin, melamine resin, alkyd resin, and mixtures thereof.
• the lightness of the color of the third colored layer 27 may be lower than the lightness of the color of the first colored layer 15, or may be higher than the lightness of the color of the first colored layer 15.
• the color of the third colored layer 27 is black.
• a reflective sheet R2 in which the release liner 11, the adhesive layer 12, the retroreflective layer 13 having and a third colored layer 27, and the clear layer 14 are stacked is prepared.
• the yellow liquid LI is coated on the clear layer 14 of the reflective sheet R2, and the coated yellow liquid LI is dried to form the first colored layer 15.
• the black liquid L2 is coated on the first colored layer 15, and the coated black liquid L2 is dried to form the second colored layer 16, completing the retroreflective film IOC.
• the retroreflective film IOC in accordance with Lourth embodiment has the third colored layer 27 positioned on the opposite side to the second colored layer 16 when viewed from the first colored layer 15, and the lightness of the color of the third colored layer 27 may be lower than the lightness of the color of the first colored layer 15.
• the third colored layer 27 is disposed on the opposite side to the second colored layer 16 across the first colored layer 15, and the lightness of the color of the third colored layer 27 is lower than the lightness of the color of the first colored layer 15.
• the first colored layer 15 is sandwiched between the second colored layer 16 and the third colored layer 27 that have a lower lightness than the lightness of the first colored layer 15. Since the first colored layer 15 is sandwiched between the second colored layer 16 and the third colored layer 27 of lower lightness, the color of lower lightness is visible at daytime, further improving design.
• the third colored layer 27 may be a bond layer that covers the bead layer 19 including the plurality of beads 19b.
• the bond layer 20 covering the bead layer 19 since the third colored layer 27, which is positioned on the opposite side to the second colored layer 16 across the first colored layer 15 and has color of low lightness, is the bond layer 20 covering the bead layer 19, color irregularities can be suppressed while enhancing the black color of the retroreflective film IOC at daytime.
• a retroreflective film 10D in accordance with Fifth embodiment will be described below with reference to FIG. 6B.
• the thickness of the second colored layer 16 of the retroreflective film 10D is larger than the second colored layer 16 of the retroreflective film IOC.
• the thickness of the second colored layer 16 of the retroreflective film 10D is, for example, 50 pm or more and 100 pm or less, and may be 55 pm or more and 65 pm or less.
• the retroreflective film 10D in accordance with Fifth Embodiment has the same effects as those of the retroreflective film IOC.
• the retroreflective film 10E includes a first colored layer 25 having a configuration that is different from that of the first colored layer 15.
• the first colored layer 25 is a layer formed on the clear layer 14 by printing.
• the first colored layer 25 may be a layer printed using an inkjet printer, for example. In this case, the first colored layer 25 is formed by applying ink in a dot pattern.
• the reflective sheet R2 in which the release liner 11, the adhesive layer 12, the retroreflective layer 13, and the clear layer 14 are stacked is prepared. Then, the reflective sheet R2 is printed by an inkjet printer to form the first colored layer 25 formed of dot-like ink on the clear layer 14. Thereafter, the black liquid L2 is coated on the first colored layer 25 and the black liquid L2 is dried to form the second colored layer 16 to complete the making of the retroreflective film 10E.
• the first colored layer 25 is formed using the inkjet printer. That is, the first colored layer 25 is formed of the dot-like ink. In this case, the degree of masking by the first colored layer 25 can be increased and color irregularities of the first colored layer 25 can be reduced, further improving design of the retroreflective film 10E at nighttime.
• a retroreflective film 10F in accordance with Seventh embodiment will be described below with reference to FIGS. 8 A and 8B.
• the retroreflective film 10F differs from the retroreflective film 10E in that an adhesive layer 32 and a clear layer 34 are provided between the first colored layer 25 and the second colored layer 16.
• the adhesive layer 32 may include, for example, an acrylic adhesive, a rubber-based adhesive, a silicone-based adhesive, or an acrylic foam agent, and may be formed from a material that is similar to the material for the adhesive layer 12 described above.
• a thickness of the adhesive layer 32 is, for example, 10 pm or more and 50 pm or less.
• the clear layer 34 is formed from PVC (polyvinyl alcohol), for example, and may be formed from the same material as the clear layer 14 described above.
• the thickness of the clear layer 34 may be, for example, 10 pm or more and 100 pm, such as 50 pm, and may be changed as appropriate.
• the retroreflective fdm 10F first, the first colored layer 25 is printed on the reflective sheet R2 and then, the clear layer 34 with the adhesive layer 32 is laminated onto the first colored layer 25. Thereafter, as described above, the black liquid L2 is coated and dried to form the second colored layer 16 on the clear layer 34, to complete the retroreflective film 10F.
• the thickness of the second colored layer 16 is, for example, 50 pm or more and 60 pm or less.
• the retroreflective film 10F achieves the same effects as the retroreflective film 10E.
• the retroreflective film 10G differs from the retroreflective film 10F described above in that an adhesive layer 35 and a transparent resin layer 36 are further provided between the clear layer 34 and the second colored layer 16.
• the adhesive layer 35 may be formed from the same material as the adhesive layer 12, 32 described above, for example, and the thickness of the adhesive layer 35 is 30 pm or more and 50 pm or less (40 pm as an example).
• the transparent resin layer 36 is formed from polyethylene terephthalate (PET), but may also be formed from other resin materials.
• the retroreflective film 10G first, as illustrated in FIGS. 9A and 9B, the first colored layer 25 is printed on the reflective sheet R2 and then, the clear layer 34 with the adhesive layer 32 is laminated onto the first colored layer 25. As illustrated in FIG. 9C, the black liquid L2 is coated on the transparent resin layer 36 and dried to form the second colored layer 16 on the transparent resin layer 36.
• the black liquid L2 having a thickness of, for example, 40 pm or more and 60 pm or less is dried to form the second colored layer 16 having a thickness of 30 pm or more and 35 pm or less (as an example, 32 pm).
• the adhesive layer 35 is laminated on the clear layer 34, and the transparent resin layer 36 on which the second colored layer 16 is formed is laminated onto the clear layer 34 via the adhesive layer 35. This completes the making of the retroreflective film 10G.
• FIG. 10B is a view illustrating a retroreflective film 10H in accordance with Ninth Embodiment.
• the thickness of the second colored layer 16 of the retroreflective film 10H is greater than the thickness of the second colored layer 16 of the retroreflective film 10G.
• the thickness of the second colored layer 16 of the retroreflective film 10H is, for example, 50 pm or more and 100 pm or less, and may be 50 pm or more and 60 pm or less.
• the method for making the retroreflective film 10H is the same as the method for making the retroreflective film 10G.
• a retroreflective film 10J in accordance with Tenth Embodiment will be described below with reference to FIGS. 11A and 11B.
• the retroreflective film 10J differs from the retroreflective films described above in that a first colored layer 45 of green color is provided instead of the first colored layer 25.
• green includes not only pure green but also colors greenish colors such as blue- green, yellow green, and the like, and meaning green in a broad sense.
• the first colored layer 45 is formed, for example, on the clear layer 14 by printing. In this case, the first colored layer 45 is formed by applying ink in a dot pattern.
• the first colored layer 45 may be, for example, a layer formed using an inkjet printer or a layer formed of green liquid (green pigment).
• the reflective sheet R2 is printed using the inkjet printer to form the first colored layer 45 constituted of dot-like ink on the clear layer 14. Thereafter, the black liquid F2 is coated on the first colored layer 45 and dried to complete the making of the retroreflective film 10J.
• the retroreflective film 10J includes the green first colored layer 45 and thus, can shine green at nighttime.
• yellow has an image that enhances concentration or judgment and draws attention, whereas green has a healing and relaxing effect on the body.
• the retroreflective films 10 to 10H may each has the yellow first colored layer 15, advantageously calling attention.
• the retroreflective film 10J has the green first colored layer 45, increasing the relaxing and calming effects.
• FIGS. 12A and 12B are views illustrating a retroreflective film 10K in accordance with Eleventh Embodiment.
• the retroreflective film 10K differs from the retroreflective film 10J in that the adhesive layer 32 and the clear layer 34 are provided between the first colored layer 45 and the second colored layer 16.
• the first colored layer 45 is printed on the reflective sheet R2 and then, the clear layer 34 with the adhesive layer 32 is laminated onto the first colored layer 45. Thereafter, as described above, the black liquid F2 is coated and dried to form the second colored layer 16 on the clear layer 34, to complete the retroreflective film 10K.
• the retroreflective film 10K achieves the same effects as the retroreflective film 10J.
• FIGS. 13A to 14B illustrate a retroreflective film 10F and a method for making the retroreflective film 10F in accordance with Thirteenth Embodiment.
• the retroreflective film 10F differs from the retroreflective film 10K in that the adhesive layer 35 and the transparent resin layer 36 are provided between the clear layer 34 and the second colored layer 16.
• the first colored layer 45 is printed on the reflective sheet R2 and then, the clear layer 34 with the adhesive layer 32 is laminated onto the first colored layer 45.
• the black liquid L2 is coated on the transparent resin layer 36 and dried to form the second colored layer 16 on the transparent resin layer 36.
• the adhesive layer 35 is laminated on the clear layer 34, and the transparent resin layer 36 on which the second colored layer 16 is formed is laminated onto the clear layer 34 via the adhesive layer 35. This completes the making of the retroreflective film 10L.
• FIG. 14C is a view illustrating a retroreflective film 10M in accordance with Thirteenth Embodiment.
• the thickness of the second colored layer 16 of the retroreflective film 10M is larger than the thickness of the second colored layer 16 of the retroreflective film 10L.
• the thickness of the second colored layer 16 of the retroreflective film 10M is, for example, 50 pm or more and 100 pm or less, and may be 50 pm or more and 60 pm or less.
• a retroreflective film 10N in accordance with Fourteenth Embodiment will be described below with reference to FIGS. 15A and 15B.
• the retroreflective film 10N differs from the retroreflective films described above in that a blue first colored layer 55 is provided instead of the first colored layer 25 or 45.
• the first colored layer 55 is formed, for example, on the clear layer 14 by printing.
• the first colored layer 55 may be a layer formed using the inkjet printer, or may be a layer formed of blue liquid (blue pigment).
• the reflective sheet R2 is printed using the inkjet printer to form the first colored layer 55 constituted of dot-like ink on the clear layer 14. Thereafter, the black liquid L2 is coated on the first colored layer 55 and dried to complete the making of the retroreflective film 10N.
• the retroreflective film 10N includes the blue first colored layer 55 and thus, can shine blue at nighttime. Generally, blue has an image that increases concentration and calms mind. Thus, the retroreflective film 10N including the blue first colored layer 55 can enhance concentration and increase the relaxing effect.
• FIGS. 16A and 16B are views illustrating a retroreflective film 10P in accordance with Fifteenth Embodiment.
• the retroreflective film 10P differs from the retroreflective film 10N in that the adhesive layer 32 and the clear layer 34 are provided between the first colored layer 55 and the second colored layer 16.
• the first colored layer 55 is printed on the reflective sheet R2 and then, the clear layer 34 with the adhesive layer 32 is laminated onto the first colored layer 55. Then, the black liquid L2 is coated and dried to form the second colored layer 16 on the clear layer 34, completing a series of making steps.
• the retroreflective film 10P achieves the same effects as the retroreflective film 10N.
• FIGS. 17A to 17C and FIGS. 18A and 18B illustrate a retroreflective film 10Q and a method for making the retroreflective film 10Q in accordance with Sixteenth Embodiment.
• the retroreflective film 10Q differs from the retroreflective film 10P in that the adhesive layer 32, the clear layer 34, the adhesive layer 35, and the transparent resin layer 36 are provided between the first colored layer 55 and the second colored layer 16.
• the first colored layer 55 is printed on the reflective sheet R2 to laminate the clear layer 34 with the adhesive layer 32 onto the first colored layer 55.
• the black liquid L2 is coated on the transparent resin layer 36 and dried to form the second colored layer 16 on the transparent resin layer 36.
• the adhesive layer 35 is laminated onto the clear layer 34 and then, the transparent resin layer 36 on which the second colored layer 16 is formed is laminated onto the clear layer 34 via the adhesive layer 35.
• FIG. 18C is a view illustrating a retroreflective film 10R in accordance with Seventeenth Embodiment.
• the thickness of the second colored layer 16 of the retroreflective film lOR is larger than the second colored layer 16 of the retroreflective film 10Q.
• the thickness of the second colored layer 16 of the retroreflective film 10R is, for example, 50 pm or more and 100 pm or less, and may be 50 pm or more and 60 pm or less.
• the retroreflective film 10 illustrated in FIG. 3 was used as the retroreflective film in Example 1. Specifically, the retroreflective film 10 had the release liner 11, the adhesive layer 12, the retroreflective layer 13, the clear layer 14, the yellow first colored layer 15, and the black second colored layer 16. The thickness of the clear layer 14 was 58 pm, the thickness of the first colored layer 15 was 5 pm, and the thickness of the second colored layer 16 was 30 pm.
• Example 1 a ScotchcalTM reflective sheet white including the release liner 11, the adhesive layer 12, the retroreflective layer 13, and the clear layer 14 was used.
• Irgaphor registered trademark
• DISPERBYK-2000 0.66 mass% of wet dispersing agent manufactured by BYK
• Dispersant soldsperse (registered trademark) 22000 manufactured by Lubrizol Corporation
• Paint Joncryl
• the retroreflective film 10A illustrated in FIG. 5 A was used as the retroreflective film in Example 2. Specifically, in the retroreflective film 10A including the release liner 11, the adhesive layer 12, the retroreflective layer 13, the clear layer 14, the yellow first colored layer 15, and the black second colored layer 16, the thickness of the clear layer 14 was 58 pm, the thickness of the first colored layer 15 was 5 pm, and the thickness of the second colored layer 16 was 60 pm.
• the materials for the first colored layer 15 and the second colored layer 16 are the same as those in Example 1.
• the retroreflective film 10B illustrated in FIG. 5B was used as the retroreflective film in Example 3.
• a material for the second colored layer 26 of the retroreflective film in Example 3 differs from the material for the second colored layer 16 in Example 1.
• the thickness of the second colored layer 26 was 30 pm.
• the retroreflective fdm IOC illustrated in FIG. 6A was used as the retroreflective fdm in Example 4.
• the thickness of the clear layer 14 was 58 pm
• the thickness of the first colored layer 15 was 5 pm
• the thickness of the second colored layer 16 was 30 pm.
• the color of the third colored layer 27 was black.
• the retroreflective film 10D illustrated in FIG. 6B was used as the retroreflective film in Example 5.
• the thickness of the second colored layer 16 was 60 pm.
• the retroreflective film 10E illustrated in FIG. 7B was used as the retroreflective film in Example 6.
• the retroreflective film in Example 6 differs from the retroreflective film in Example 1 in that a first colored layer 25 formed by printing is used instead of the first colored layer 15.
• the first colored layer 25 was printed using an inkjet printer (iPD8400SE manufactured by Canon Corporation).
• the retroreflective film 10F illustrated in FIG. 8B was used as the retroreflective film in Example 7.
• the thickness of the second colored layer 16 was 54 pm
• the thickness of the adhesive layer 32 was 30 pm
• the thickness of the clear layer 34 was 54 pm.
• the retroreflective film 10G illustrated in FIG. 10A was used as the retroreflective film in Example 8.
• the thickness of the clear layer 14 was 58 pm
• the thickness of the adhesive layer 32 was 40 pm
• the thickness of the clear layer 34 was 50 pm
• the thickness of the adhesive layer 35 was 40 pm
• the thickness of the transparent resin layer 36 was 50 pm
• the thickness of the second colored layer 16 was 33 pm.
• the thickness of the second colored layer 16 of the retroreflective film in Example 8 was 54 pm.
• the retroreflective film in Example 10 was a retroreflective film 10J including a printed green first colored layer 45 as illustrated in FIG. 1 IB.
• the thickness of the clear layer 14 was 58 pm, and the thickness of the second colored layer 16 was 54 pm.
• the retroreflective film 10K illustrated in FIG. 12B was used as the retroreflective film in Example 11.
• the thickness of the clear layer 14 was 58 pm
• the thickness of the adhesive layer 32 was 30 pm
• the thickness of the clear layer 34 was 50 pm
• the thickness of the second colored layer 16 was 54 pm.
• the retroreflective film 10M illustrated in FIG. 14B was used as the retroreflective film in Example 12.
• the thickness of the clear layer 14 was 58 pm
• the thickness of the adhesive layer 32 was 35 pm
• the thickness of the clear layer 34 was 50 pm
• the thickness of the adhesive layer 35 was 40 pm
• the thickness of the transparent resin layer 36 was 50 pm
• the thickness of the second colored layer 16 was 33 pm.
• the thickness of the second colored layer 16 of the retroreflective film in Example 12 was 54 pm.
• the retroreflective film in Example 14 was a retroreflective film 10N including a printed blue first colored layer 55 as illustrated in FIG. 15B.
• the thickness of the clear layer 14 was 58 pm, and the thickness of the second colored layer 16 was 54 pm.
• the retroreflective film 10P illustrated in FIG. 16B was used as the retroreflective film in Example 15.
• the thickness of the clear layer 14 was 58 pm
• the thickness of the adhesive layer 32 was 30 pm
• the thickness of the clear layer 34 was 50 pm
• the thickness of the second colored layer 16 was 54 pm.
• the retroreflective film 10Q illustrated in FIG. 18B was used as the retroreflective film in Example 16.
• the thickness of the clear layer 14 was 58 pm
• the thickness of the adhesive layer 32 was 35 pm
• the thickness of the clear layer 34 was 50 pm
• the thickness of the adhesive layer 35 was 40 pm
• the thickness of the transparent resin layer 36 was 50 pm
• the thickness of the second colored layer 16 was 33 pm.
• the thickness of the second colored layer 16 of the retroreflective film in Example 16 was 54 pm.
• a Scotchcal (registered trademark) retroreflective sheet white was used as a retroreflective film of Comparative Example 1.
• the retroreflective film of Comparative Example 1 is the retroreflective film in Example 1, excluding the clear layer 14, the first colored layer 15, and the second colored layer 16.
• a Scotchcal (registered trademark) retroreflective sheet black was used as a retroreflective film of Comparative Example 2.
• the retroreflective film in Comparative Example 2 is the retroreflective film IOC illustrated in FIG. 6A, excluding the clear layer 14, the first colored layer 15, and the second colored layer 16.
• the retroreflective coefficient was obtained by measuring the retroreflective coefficient (retroreflective coefficient R0.2) at an observation angle of 0.2 degrees and an incident angle of 5 degrees with a retroreflective measurement device Retrosign Type 4500 (Delta Light Optics, Lyngby, Denmark). That is, the retroreflective coefficient was obtained by irradiating the retroreflective film with light of constant luminance from a light projector and measuring the luminance of light reflected back from the retroreflective film.
• the retroreflective coefficients in Table 1 each indicate an average value of results obtained by measuring three points under conditions where the observation angle, which is the angle difference between the light projector and a light receiver described above, is 0.2 degrees and the angle of incidence, which is the difference between the perpendicular line with respect to the retroreflective film and the angle of the light projector, is 5 degrees.
• the lightness of the color at nighttime could be made higher than the lightness of the color at daytime, bringing particularly favorable results.
• the retroreflective films in Examples 8, 9 that include the adhesive layer 32 and the clear layer 34 together with the second colored layer 16 having a thickness of 33 pm or 54 pm shone yellow at nighttime, bringing favorable results.
• Example 10 in which the thickness of the clear layer 14 was 58 pm and the thickness of the second colored layer 16 was 54 pm, and in Example 11 in which the adhesive layer 32 and the clear layer 34 were further provided, the retroreflective films when irradiated with linear light shone green, bringing particularly favorable results. Also, in the Examples 12, 13 in which the thickness of the adhesive layer 35 was 40 pm, the thickness of the transparent resin layer 36 was 50 pm, and the thickness of the second colored layer 16 was 33 pm or 54 pm, the same favorable results as described above were obtained.
• Example 14 in which the thickness of the clear layer 14 was 58 pm and the thickness of the second colored layer 16 was 54 pm, and in Example 15 in which the adhesive layer 32 and the clear layer 34 were further provided, the retroreflective films when irradiated with linear light shone blue, bringing particularly favorable results. Also, in the Examples 16, 17 in which the thickness of the adhesive layer 35 was 40 pm, the thickness of the transparent resin layer 36 was 50 pm, and the thickness of the second colored layer 16 was 33 pm or 54 pm, the same favorable results as described above were obtained.
• the black of the retroreflective film can be exhibited at daytime, and when irradiated with linear light, can shine with color (chromatic color) other than black, bringing favorable results.
• the retroreflective film 10 includes the bead layer 19.
• the retroreflective film may not include the bead layer, and may be provided with a prism layer instead of the bead layer 19. In this case, light can be retroreflected from the retroreflective layer provided with a prism, achieving the same effects as described above.
• a retroreflective film 10 including the black second colored layer 16 was illustrated.
• the color of the second colored layer may be any color other than black, and may be changed as appropriate as long as the color has a lower lightness than the color of the first colored layer.
• the color of the first colored layer is not limited to yellow, green, or blue, and may be white, red, pink, brown, orange, yellow, or purple, and be changed as appropriate.
• the retroreflective film 10 is applied to the vehicle body 1.
• the retroreflective film may be applied to an object other than the vehicle body.
• the retroreflective film may be a retroreflective film applied to a bicycle, a retroreflective film applied to a ship, a retroreflective film applied to a railway vehicle, a retroreflective film applied to an aircraft, a retroreflective film applied to a moving machine, or a retroreflective film applied to an object other than a moving body.
• the adherend to which the retroreflective film is applied can be appropriately changed.
• Retroreflective film Vehicle body (adherend), 10, 10A, 10B, IOC, 10D, 10E, 10F, 10G, 10H, 10J, 10K, 10L, 10M, 10N, 10P, 10Q, 10R: Retroreflective film, 13: Retroreflective layer, 15, 25, 45, 55: First colored layer, 16, 16A, 26: Second colored layer, 20: Bond layer, 27: Third colored layer.

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• Optics & Photonics (AREA)
• Optical Elements Other Than Lenses (AREA)
• Laminated Bodies (AREA)

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Citations (3)

• 2019
  • 2019-06-28 JP JP2019121274A patent/JP2021006887A/ja not_active Withdrawn
• 2020
  • 2020-06-23 WO PCT/IB2020/055928 patent/WO2020261119A1/en active Application Filing

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