Transparent laminate film, transparent laminate film with protective film, and face shield

Abstract

To provide a transparent laminated film, a transparent laminated film with a protection film, and a face shield, which are capable of enhancing designability or clearly displaying a character and symbol information.SOLUTION: A transparent laminated film 30 at least comprises a core layer 32, and a printed layer 33 covering a surface portion on a front face 301 side of the core layer 32 or a surface portion on a rear face 302 side thereof. In a region without the printed layer 33, a luminous reflectance Y value is from 0.0% to 2.0% inclusive.SELECTED DRAWING: Figure 4A

Description

[Technical field]

[0001] The present disclosure relates to a transparent laminate film, a transparent laminate film with a protective film, and a face shield. [Background technology]

[0002] Conventionally, face shields for preventing droplets of saliva and the like caused by sneezing or coughing from adhering to the face of an opposing person have been known (see, for example, Patent Document 1). Patent Document 1 discloses a face shield that is made up of a shield part that is provided in front of the wearer's face and a frame for holding the shield part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Registered Utility Model No. 3227450 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, such face shields may be worn by employees at an event venue. In this case, the face shield may be required to have a design to liven up the event. Also, event participants may paint their faces to enhance the sense of unity at the event venue. In this case, ink or the like is often applied directly to the faces of the participants, which may take time to form the design on the face, and may require even more effort to remove the paint after the event. For this reason, there is a demand for face shields that can improve the design.

[0005] Face shields are also used in medical settings, etc. For example, in cases where strict management of epidemic prevention equipment is required in medical settings, etc., it is desirable to clearly display information on the face shield indicating the wearer's affiliation, the date and time when the epidemic prevention equipment was first used, etc.

[0006] The present disclosure has been made in consideration of these points, and aims to provide a transparent laminate film, a transparent laminate film with a protective film, and a face shield that can improve design or clearly display letter or symbol information. [Means for solving the problem]

[0007] A transparent laminate film according to one embodiment is a transparent laminate film having a front surface and a back surface, and comprises at least a core layer and a printed layer covering a portion of the front surface or a portion of the back surface of the core layer, and in areas where the printed layer is not provided, the luminous reflectance Y value is 0.0% or more and 2.0% or less.

[0008] In the transparent laminate film according to one embodiment, in an area where the printed layer is not provided, the reflectance of light having a wavelength of 550 nm may be 2% or less, and the total light transmittance may be 90% or more.

[0009] In the transparent laminate film according to one embodiment, in an area where the printed layer is not provided, the transmittance in the ultraviolet region having a wavelength of 380 nm or less may be 1% or less.

[0010] In one embodiment of the transparent laminate film, the core layer may include polyethylene terephthalate.

[0011] In one embodiment of a transparent laminate film, the film further comprises a front-side antireflection layer provided on one side of the core layer and constituting the front surface, and a back-side antireflection layer provided on the other side of the core layer and constituting the back surface, and the printing layer may be provided between the core layer and the front-side antireflection layer.

[0012] In one embodiment, the transparent laminate film further comprises a front-side antireflection layer provided on one side of the core layer and constituting the front surface, and a back-side antireflection layer provided on the other side of the core layer and constituting the back surface, and the printing layer may be provided between the core layer and the back-side antireflection layer.

[0013] In one embodiment of the transparent laminate film, the transparent laminate film may further include a first transparent adhesive layer that bonds the front-surface antireflection layer and the core layer, and a second transparent adhesive layer that bonds the core layer and the rear-surface antireflection layer.

[0014] In the transparent laminate film according to one embodiment, the first transparent adhesive layer and the second transparent adhesive layer may each contain an acrylic adhesive.

[0015] A transparent laminate film according to one embodiment comprises a front-side antireflection layer constituting a front surface, a back-side antireflection layer constituting a back surface, and a printed layer provided between the front-side antireflection layer and the back-side antireflection layer and covering a portion of the front-side antireflection layer, and has a luminous reflectance Y value of 0.0% or more and 2.0% or less in an area where the printed layer is not provided.

[0016] In the transparent laminate film according to one embodiment, in an area where the printed layer is not provided, the reflectance of light having a wavelength of 550 nm may be 2% or less, and the total light transmittance may be 90% or more.

[0017] In the transparent laminate film according to one embodiment, in an area where the printed layer is not provided, the transmittance in the ultraviolet region having a wavelength of 380 nm or less may be 1% or less.

[0018] In a transparent laminate film according to one embodiment, the front-side antireflection layer may have a front-side antireflection functional layer and a front-side transparent substrate layer arranged in that order from the front side to the back side, and the back-side antireflection layer may have a back-side antireflection functional layer and a back-side transparent substrate layer arranged in that order from the back side to the front side.

[0019] In one embodiment of the transparent laminate film, the front-side antireflection functional layer may be a coating layer coated on the front-side transparent substrate layer, and the rear-side antireflection functional layer may be a coating layer coated on the rear-side transparent substrate layer.

[0020] In the transparent laminate film according to one embodiment, the front-surface antireflection functional layer and the back-surface antireflection functional layer may each be made of a cured product of an ionizing radiation curable resin composition.

[0021] In the transparent laminate film according to one embodiment, the ionizing radiation curable resin composition may contain a (meth)acrylate compound.

[0022] In one embodiment of the transparent laminate film, the front-side antireflection functional layer includes a front-side refraction layer and a front-side hard coat layer arranged in that order from the front side to the back side, and the back-side antireflection functional layer may include a back-side refraction layer and a back-side hard coat layer arranged in that order from the back side to the front side.

[0023] In the transparent laminate film according to one embodiment, the front hard coat layer may be a coating layer coated on the front transparent substrate layer, the front refractive layer may be a coating layer coated on the front hard coat layer, the rear hard coat layer may be a coating layer coated on the rear transparent substrate layer, and the rear refractive layer may be a coating layer coated on the rear hard coat layer.

[0024] In one embodiment of a transparent laminate film, the surface refractive layer may include a surface low refractive index layer and a surface high refractive index layer arranged in that order from the surface to the back surface, and the back surface refractive layer may include a back surface low refractive index layer and a back surface high refractive index layer arranged in that order from the back surface to the surface.

[0025] In a transparent laminate film according to one embodiment, the surface high refractive index layer may include a first surface high refractive index layer and a second surface high refractive index layer arranged in order from the surface to the back surface, and the back surface high refractive index layer may include a first back surface high refractive index layer and a second back surface high refractive index layer arranged in order from the back surface to the surface.

[0026] In one embodiment of a transparent laminate film, the refractive index of the first surface high refractive index layer may be higher than the refractive index of the second surface high refractive index layer, and the refractive index of the first back surface high refractive index layer may be higher than the refractive index of the second back surface high refractive index layer.

[0027] In the transparent laminate film according to one embodiment, the front transparent substrate layer and the back transparent substrate layer may contain triacetyl cellulose or polyethylene terephthalate.

[0028] In the transparent laminate film according to one embodiment, one of the front transparent substrate layer and the back transparent substrate layer may contain triacetyl cellulose, and the other may contain polyester.

[0029] In the transparent laminate film according to one embodiment, the front transparent substrate layer and the back transparent substrate layer may each contain polyester.

[0030] In the transparent laminate film according to one embodiment, the thickness may be 40 μm or more and 500 μm or less.

[0031] The transparent laminate film according to one embodiment may have a restoring function.

[0032] The transparent laminate film according to one embodiment may be used in a face shield to protect the face of a wearer.

[0033] A transparent laminate film with a protective film according to one embodiment is a transparent laminate film with a protective film comprising a transparent laminate film according to one embodiment, a surface protective film that protects the front surface of the transparent laminate film, and a back surface protective film that protects the back surface of the transparent laminate film.

[0034] A face shield according to one embodiment is a face shield for protecting the face of a wearer, comprising a holding member worn by the wearer, and a transparent laminate film according to one embodiment attached to the holding member and covering at least a portion of the wearer's face.

[0035] In one embodiment of the face shield, the printed layer may be provided in a position overlapping the cheek of the wearer when viewed from the front.

[0036] In one embodiment, when the wearer wears the face shield, a distance between the wearer's nose and the holding member may be 100 mm or less.

[0037] In a face shield according to one embodiment, the retaining member may have a pair of temple portions that abut against the wearer's ears, a front portion that connects the pair of temple portions to each other, and a pair of pad portions that extend downward from the front portion and abut against the wearer's nose.

[0038] In one embodiment of the face shield, the retaining member may have a band that circumferentially covers the wearer's head.

[0039] In one embodiment of a face shield, the retaining member has a chin pad that abuts the wearer's chin and a pair of hook portions that are connected to the chin pad and hooked onto the wearer's ears, and the transparent laminate film may cover at least the wearer's mouth. Effect of the Invention

[0040] According to the present disclosure, the design of the transparent laminate film and face shield can be improved, or text or symbol information can be clearly displayed on the transparent laminate film and face shield. [Brief description of the drawings]

[0041] [Figure 1] FIG. 1 is a perspective view showing a face shield according to the present embodiment. [Diagram 2] FIG. 2 is a top view showing the face shield according to the present embodiment. [Diagram 3] FIG. 3 is a front view showing a shield portion of the face shield according to the present embodiment. [Figure 4A] FIG. 4A is a cross-sectional view showing an example of a layer structure of a protective film-attached transparent laminate film according to the present embodiment. [Figure 4B] FIG. 4B is a cross-sectional view showing an example of the layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Figure 4C] FIG. 4C is a cross-sectional view showing an example of a layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Figure 4D] FIG. 4D is a cross-sectional view showing an example of the layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Figure 4E] FIG. 4E is a cross-sectional view showing an example of a layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Figure 4F] FIG. 4F is a cross-sectional view showing an example of the layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Figure 4G] FIG. 4G is a cross-sectional view showing an example of the layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Figure 4H] FIG. 4H is a cross-sectional view showing an example of the layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Figure 4I]FIG. 4I is a cross-sectional view showing an example of a layer structure of a transparent laminate film with a protective film according to the present embodiment. [Figure 4J] FIG. 4J is a cross-sectional view showing an example of a layer structure of the protective film-attached transparent laminate film according to the present embodiment. [Diagram 5] FIG. 5 is a perspective view showing a modification of the face shield according to the present embodiment. [Figure 6] FIG. 6 is a perspective view showing a modification of the face shield according to the present embodiment. [Figure 7] FIG. 7 is a perspective view showing another example of use of the transparent laminate film according to the present embodiment. [Figure 8] FIG. 8 is a front view showing the transparent laminate film of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] An embodiment will be described below with reference to the drawings. FIGS. 1 to 4J are diagrams showing an embodiment. Each of the figures shown below is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, it is possible to carry out appropriate modifications within the scope of the technical idea. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values ​​such as the dimensions of each member and the material names described in this specification are examples of an embodiment, and are not limited to these, and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are intended to include substantially the same state in addition to their strict meanings.

[0043] Face shield First, a face shield 10 including a transparent laminate film 30 according to the present embodiment will be described with reference to Figures 1 to 3. This face shield 10 is for protecting the face F of a wearer H.

[0044] 1 and 2, the face shield 10 includes a holding member 20 that is worn by a wearer H, and a shield portion 30A (transparent laminate film 30) that is attached to the holding member 20 and covers the face F of the wearer H. Of these, the holding member 20 has a pair of temple portions 21 that come into contact with the ears E of the wearer H, a front portion 22 that connects the pair of temple portions 21 to each other, and a pair of pad portions 23 that extend downward from the front portion 22 and come into contact with the nose N of the wearer H. In this embodiment, the holding member 20 is of a so-called eyeglass frame type.

[0045] As shown in FIG. 2, such a retaining member 20 holds the shield portion 30A so that, when the wearer H wears the face shield 10, a desired gap is formed between the nose N, mouth, etc. of the wearer H and the shield portion 30A.

[0046] When the wearer H wears the face shield 10, the distance D1 (see FIG. 2) between the nose N of the wearer H and the shield part 30A is preferably 100 mm or less, more preferably 3 mm or more and 100 mm or less, and even more preferably 5 mm or more and 100 mm or less. When the distance D1 is 3 mm or more, the transparent laminate film 30 constituting the shield part 30A can be prevented from coming into contact with the face F of the wearer H when the wearer H moves his / her head. Therefore, even when the wearer H wears the face shield 10, the wearer H can concentrate on his / her work without feeling stress. In addition, when the distance D1 is 100 mm or less, the transparent laminate film 30 constituting the shield part 30A can be prevented from coming into contact with surrounding structures or other people when the wearer H moves his / her head. In addition, when the distance D1 is 100 mm or less, the weight of the face shield 10 can be prevented from becoming too large. Therefore, the wearer H can concentrate on work without feeling stressed even when wearing the face shield 10. Furthermore, since the distance D1 is 100 mm or less, droplets of saliva, etc. caused by the wearer H sneezing or coughing can be effectively prevented from landing on the face of another person, and droplets of saliva, etc. caused by another person sneezing or coughing can be effectively prevented from landing on the wearer H's face.

[0047] Although there is no limitation on the material of the holding member 20, it is desirable that the holding member 20 be made of resin from the viewpoints of flexibility, light weight, ease of procurement, etc. The resin material used for the holding member 20 can be selected from resin materials that are generally used.

[0048] The shield part 30A plays a role in preventing droplets of saliva, etc., caused by sneezing or coughing by the wearer H from adhering to the face of another person, and droplets of saliva, etc., caused by sneezing or coughing by another person from adhering to the face F of the wearer H. The shield part 30A is composed of a transparent laminated film 30. In this embodiment, the shield part 30A covers the entire face F of the wearer H. The shape of the shield part 30A is arbitrary, and the shield part 30A may have a rectangular shape, a rectangular shape with rounded corners, an elliptical shape, or the like. The size of the shield part 30A is preferably a certain size or more from the viewpoint of preventing droplets from scattering, and is preferably a square of 10 cm square or more. In addition, from the viewpoint of not interfering with the movement of the wearer H, it is preferable that the size of the shield part 30A is a square of 40 cm square or less.

[0049] In this embodiment, the shield part 30A (transparent laminate film 30) has a printed layer 33. As shown in FIG. 3, the printed layer 33 is provided at a position overlapping the cheek C of the wearer H in front view. This allows the observer to have the impression that the character or the like displayed by the printed layer 33 is directly printed on the face F. In this case, when the shield part 30A is removed from the holding member 20, the printed layer 33 is preferably provided in an area with a length L from the central axis CL of the shield part 30A of 100 mm or less. This allows the printed layer 33 to overlap the cheek C of the wearer H in a state where the wearer H wears the face shield 10. The printed layer 33 may display information such as characters, figures, marks, and other patterns and letters. In the illustrated example, the printed layer 33 displays a star-shaped, moon-shaped, or flower-shaped pattern. In addition, the printed layer 33 is preferably provided at a position that does not overlap the eyes of the wearer H in front view.

[0050] This shield part 30A may be attached to the holding member 20 via an attachment member (not shown). Alternatively, although not shown, for example, an engaging part such as a protrusion may be provided on the holding member 20, and an engaged part such as a through hole may be provided on the shield part 30A. Then, the engaged part may engage with the engaging part, thereby attaching the shield part 30A to the holding member 20.

[0051] Transparent laminated film with protective film Next, a description will be given of a transparent laminate film 60 with a protective film according to the present embodiment. Fig. 4A to Fig. 4J show an example of a layer structure of the transparent laminate film 60 with a protective film. As shown in Fig. 4A to Fig. 4J, the transparent laminate film 60 with a protective film includes the transparent laminate film 30 according to the present embodiment, a surface protective film 61 that protects a surface 301 of the transparent laminate film 30, and a back surface protective film 62 that protects a back surface 302 of the transparent laminate film 30.

[0052] Among these, the surface protective film 61 and the back protective film 62 serve to prevent the front surface 301 and the back surface 302 of the transparent laminate film 30 from being scratched, and to prevent the front surface 301 and the back surface 302 from being contaminated by foreign matter or the like. The surface protective film 61 and the back protective film 62 are each detachably attached to the transparent laminate film 30. The surface protective film 61 and the back protective film 62 may each include a bonding layer (not shown) and be attached to the transparent laminate film 30 by this bonding layer. The adhesive strength of the bonding layer may be, for example, about 0.05 N / 25 mm or more and 5 N / 25 mm or less. When using the face shield 10 described above, the surface protective film 61 and the back protective film 62 are each peeled off from the transparent laminate film 30. The material of the surface protective film 61 and the back protective film 62 may be, for example, a film made of a polyester resin or a polyolefin such as polyethylene or polypropylene.

[0053] Transparent Laminated Film Next, the transparent laminate film 30 according to the present embodiment will be described. As described above, the transparent laminate film 30 may be used in the face shield 10 that protects the face F of the wearer H. As shown in FIG. 4A to FIG. 4H, the transparent laminate film 30 has a front surface 301 and a back surface 302, and at least includes a core layer 32 and a printed layer 33 that covers a part of the front surface 301 side or a part of the back surface 302 side of the core layer 32. The transparent laminate film 30 also includes a front surface antireflection layer 40 that is provided on one side of the core layer 32 and constitutes the front surface 301, and a back surface antireflection layer 50 that is provided on the other side of the core layer 32 and constitutes the back surface 302. Furthermore, the transparent laminate film 30 may further include a first transparent adhesive layer 31a that bonds the front surface antireflection layer 40 and the core layer 32, and a second transparent adhesive layer 31b that bonds the core layer 32 and the back surface antireflection layer 50.

[0054] Specifically, as shown in Figures 4A, 4C, and 4E, the transparent laminate film 30 includes, in this order from the front surface 301 to the back surface 302, a front surface antireflection layer 40, a first transparent adhesive layer 31a, a printing layer 33, a core layer 32, a second transparent adhesive layer 31b, and a back surface antireflection layer 50. In this case, in the transparent laminate film 30, the front surface antireflection layer 40 is exposed outward from the front surface 301 side. Also, in the transparent laminate film 30, the back surface antireflection layer 50 is exposed outward from the back surface 302 side.

[0055] 4B, 4D, and 4F, the transparent laminate film 30 includes, from the front surface 301 toward the back surface 302, the front surface antireflection layer 40, the first transparent adhesive layer 31a, the core layer 32, the printing layer 33, the second transparent adhesive layer 31b, and the back surface antireflection layer 50, in this order. Even in this case, in the transparent laminate film 30, the front surface antireflection layer 40 is exposed outward from the front surface 301 side. In the transparent laminate film 30, the back surface antireflection layer 50 is exposed outward from the back surface 302 side.

[0056] 4G, the transparent laminate film 30 includes, in this order from the front surface 301 to the back surface 302, a front surface antireflection layer 40, a printed layer 33, a first transparent adhesive layer 31a, a core layer 32, a second transparent adhesive layer 31b, and a back surface antireflection layer 50. In this case as well, in the transparent laminate film 30, the front surface antireflection layer 40 is exposed outward from the front surface 301 side. In the transparent laminate film 30, the back surface antireflection layer 50 is exposed outward from the back surface 302 side.

[0057] 4H, the transparent laminate film 30 includes, from the front surface 301 toward the back surface 302, a front surface antireflection layer 40, a first transparent adhesive layer 31a, a core layer 32, a second transparent adhesive layer 31b, a printing layer 33, and a back surface antireflection layer 50, in this order. Even in this case, in the transparent laminate film 30, the front surface antireflection layer 40 is exposed outward from the front surface 301 side. In the transparent laminate film 30, the back surface antireflection layer 50 is exposed outward from the back surface 302 side.

[0058] As shown in FIGS. 4A to 4H, the front-surface antireflection layer 40 has a front-surface antireflection functional layer 41 and a front-surface transparent substrate layer 42 arranged in order from the front surface 301 to the back surface 302. The front-surface antireflection functional layer 41 includes a front-surface refraction layer 43 and a front-surface hard coat layer 44 arranged in order from the front surface 301 to the back surface 302. Here, as shown in FIGS. 4C to 4F, the front-surface refraction layer 43 may include a front-surface low-refractive index layer 45 and a front-surface high-refractive index layer 46 arranged in order from the front surface 301 to the back surface 302. As shown in FIGS. 4E and 4F, the front-surface high-refractive index layer 46 may include a first front-surface high-refractive index layer 47 and a second front-surface high-refractive index layer 48 arranged in order from the front surface 301 to the back surface 302. 4G and 4H, the front-surface antireflection layer 40 has a front-surface antireflection functional layer 41 and a front transparent substrate layer 42, and the front-surface antireflection functional layer 41 includes a front-surface refraction layer 43 and a front-surface hard coat layer 44. In this case, although not shown, in the front-surface antireflection layer 40, the front-surface refraction layer 43 may include a front-surface low refractive index layer 45 or the like, as shown in FIGS. 4C to 4F.

[0059] As shown in FIGS. 4A to 4H, the back surface antireflection layer 50 has a back surface antireflection functional layer 51 and a back surface transparent substrate layer 52 arranged in order from the back surface 302 to the front surface 301. The back surface antireflection functional layer 51 also includes a back surface refraction layer 53 and a back surface hard coat layer 54 arranged in order from the back surface 302 to the front surface 301. Here, as shown in FIGS. 4C to 4F, the back surface refraction layer 53 may include a back surface low refractive index layer 55 and a back surface high refractive index layer 56 arranged in order from the back surface 302 to the front surface 301. As shown in FIGS. 4E and 4F, the back surface high refractive index layer 56 may include a first back surface high refractive index layer 57 and a second back surface high refractive index layer 58 arranged in order from the back surface 302 to the front surface 301. 4G and 4H, the back surface antireflection layer 50 has a back surface antireflection functional layer 51 and a back surface transparent substrate layer 52, and the back surface antireflection functional layer 51 includes a back surface refraction layer 53 and a back surface hard coat layer 54. In this case, although not shown, in the back surface antireflection layer 50, the back surface refraction layer 53 may include a back surface low refractive index layer 55 or the like as shown in FIGS. 4C to 4F.

[0060] 4I and 4J, the transparent laminate film 30 may not include the core layer 32. Specifically, as shown in FIG. 4I, the transparent laminate film 30 may include a front surface antireflection layer 40, a printed layer 33, a transparent adhesive layer 31, and a back surface antireflection layer 50 in this order from the front surface 301 to the back surface 302. Even in this case, in the transparent laminate film 30, the front surface antireflection layer 40 is exposed outward from the front surface 301 side. In the transparent laminate film 30, the back surface antireflection layer 50 is exposed outward from the back surface 302 side.

[0061] 4J, the transparent laminate film 30 may include, from the front surface 301 toward the back surface 302, a front surface antireflection layer 40, a transparent adhesive layer 31, a printing layer 33, and a back surface antireflection layer 50, in this order. Even in this case, in the transparent laminate film 30, the front surface antireflection layer 40 is exposed outward from the front surface 301 side. In the transparent laminate film 30, the back surface antireflection layer 50 is exposed outward from the back surface 302 side.

[0062] In the example shown in Figures 4I and 4J, the front-surface antireflection layer 40 has a front-surface antireflection functional layer 41 and a front-surface transparent substrate layer 42, and the front-surface antireflection functional layer 41 includes a front-surface refraction layer 43 and a front-surface hard coat layer 44. The back-surface antireflection layer 50 has a back-surface antireflection functional layer 51 and a back-surface transparent substrate layer 52, and the back-surface antireflection functional layer 51 includes a back-surface refraction layer 53 and a back-surface hard coat layer 54. In this case, although not shown, in the front-surface antireflection layer 40, as shown in Figures 4C to 4F, the front-surface refraction layer 43 may include a front-surface low refractive index layer 45 or the like, and in the back-surface antireflection layer 50, the back-surface refraction layer 53 may include a back-surface low refractive index layer 55 or the like.

[0063] As described above, the front-surface antireflection layer 40 may have a basic configuration having a front-surface high refractive index layer 46 and a front-surface low refractive index layer 45 on the front-surface transparent substrate layer 42. Also, as described above, the back-surface antireflection layer 50 may have a basic configuration having a back-surface high refractive index layer 56 and a back-surface low refractive index layer 55 on the back-surface transparent substrate layer 52. The front-surface high refractive index layer 46 (back-surface high refractive index layer 56) and the front-surface low refractive index layer 45 (back-surface low refractive index layer 55) play a role in imparting an antireflection function by optical interference function.

[0064] The front-surface antireflection layer 40 (rear-surface antireflection layer 50) may be provided with an antireflection function by optical interference of three or more layers by further providing a medium refractive index layer, but a multi-layer structure with too many layers is not preferable in terms of cost-effectiveness. Therefore, the front-surface antireflection layer 40 (rear-surface antireflection layer 50) according to the present embodiment is preferably provided with an antireflection function by optical interference of two layers, the front-surface high refractive index layer 46 (rear-surface high refractive index layer 56) and the front-surface low refractive index layer 45 (rear-surface low refractive index layer 55). The front-surface antireflection layer 40 (rear-surface antireflection layer 50) may be provided with an antireflection function by optical interference of three layers, the medium refractive index layer, the high refractive index layer, and the low refractive index layer, by making the front-surface hard coat layer 44 (rear hard coat layer 54) a medium refractive index layer.

[0065] Each layer of the transparent laminate film 30 will now be described.

[0066] <Front-side anti-reflection layer and rear-side anti-reflection layer> The surface antireflection layer 40 is a layer for suppressing reflection of light incident from the surface 301 side of the transparent laminate film 30. By providing the transparent laminate film 30 with the surface antireflection layer 40, it is possible to suppress reflection of light on the surface 301 of the transparent laminate film 30. This makes it possible to improve the visibility of the face F of the wearer H when, for example, viewing the wearer H wearing the face shield 10. This makes it possible to improve the visibility of the mouth of the wearer H, and facilitate smooth communication between the wearer H and others.

[0067] On the other hand, the back surface antireflection layer 50 is a layer for suppressing reflection of light mainly incident from the back surface 302 side of the transparent laminate film 30. By providing the transparent laminate film 30 with the back surface antireflection layer 50, it is possible to suppress reflection of light on the back surface 302 of the transparent laminate film 30. This makes it possible to suppress, for example, discomfort or fatigue felt by a wearer H wearing the face shield 10 due to light reflected on the back surface 302 of the transparent laminate film 30. In addition, the back surface antireflection layer 50 plays a role in suppressing not only reflection of light incident from the back surface 302 side but also reflection of light incident from the front surface 301 side.

[0068] The front-surface antireflection layer 40 has the front-surface antireflection functional layer 41 and the front-surface transparent substrate layer 42, as described above. The back-surface antireflection layer 50 has the back-surface antireflection functional layer 51 and the back-surface transparent substrate layer 52, as described above. Here, the front-surface transparent substrate layer 42 and the back-surface transparent substrate layer 52 will be described first. The front-surface antireflection layer 40 and the back-surface antireflection layer 50 may have a configuration other than the above-mentioned layer configuration, and may each be composed of a resin film. For example, the front-surface antireflection layer 40 and the back-surface antireflection layer 50 may each use a low-reflection film (FG-10MR1, manufactured by Sharp Corporation). The front-surface antireflection layer 40 and the back-surface antireflection layer 50 may also have a structure in which irregularities are formed on the surface of a resin provided on a transparent substrate, which is generally known as a moth eye. In this case, a primer layer for improving adhesion may be provided between the transparent substrate and the resin surface. The resin with irregularities may be provided only on one side of the transparent substrate, or may be provided on both sides.

[0069] [Front transparent substrate layer and rear transparent substrate layer] The front transparent substrate layer 42 and the back transparent substrate layer 52 are layers that support, for example, the front antireflection functional layer 41 and the back antireflection functional layer 51, and increase the overall strength of the front antireflection layer 40 and the back antireflection layer 50. The material of the front transparent substrate layer 42 and the back transparent substrate layer 52 is not particularly limited as long as it is a transparent material that is used as a substrate for a general film, but from the viewpoints of material cost, productivity, etc., preferably a plastic film, a plastic sheet, etc. can be appropriately selected depending on the application.

[0070] Examples of the plastic film or sheet include those made of various synthetic resins. Examples of the synthetic resin include cellulose resins such as triacetyl cellulose resin (TAC), diacetyl cellulose, acetate butyrate cellulose, and cellophane; polyester resins such as polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyethylene naphthalate-isophthalate copolymer resin, and polyester-based thermoplastic elastomer; polyolefin resins such as low-density polyethylene resin (including linear low-density polyethylene resin), medium-density polyethylene resin, high-density polyethylene resin, ethylene-α-olefin copolymer, polypropylene resin, polymethylpentene resin, polybutene resin, ethylene-propylene copolymer, propylene-butene copolymer, olefin-based thermoplastic elastomer, and mixtures thereof; acrylic resins such as poly(methyl (meth)acrylate resin, poly(ethyl (meth)acrylate resin, and poly(butyl (meth)acrylate resin); polyamide resins such as nylon 6 or nylon 66; polystyrene resin; polycarbonate resin; polyarylate resin; and polyimide resin. Moreover, the material of the front transparent substrate layer 42 and the back transparent substrate layer 52 may be a cycloolefin polymer (COP) resin or a cycloolefin copolymer (COC) resin.

[0071] The front transparent substrate layer 42 and the back transparent substrate layer 52 may be made of one of the above-mentioned plastic films and plastic sheets, or a mixture of two or more of them, but from the viewpoints of flexibility, toughness, transparency, etc., cellulose resin and polyester resin are more preferable as the materials for the front transparent substrate layer 42 and the back transparent substrate layer 52. From the viewpoints of flexibility, toughness, transparency, etc., the front transparent substrate layer 42 and the back transparent substrate layer 52 preferably contain triacetyl cellulose and polyethylene terephthalate.

[0072] The thickness of the front transparent substrate layer 42 and the back transparent substrate layer 52 is not particularly limited and is appropriately selected according to the application. The thickness of the front transparent substrate layer 42 and the back transparent substrate layer 52 may be about 5 μm or more and 130 μm or less, respectively, and is preferably 10 μm or more and 100 μm or less in consideration of durability, handling, etc. The thickness of each layer can be calculated by measuring the thickness at 20 points from an image of a cross section taken using, for example, a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a scanning transmission electron microscope (STEM), and averaging the values ​​at the 20 points. When the film thickness to be measured is on the order of μm, it is preferable to use SEM, and when it is on the order of nm, it is preferable to use TEM or STEM. In the case of SEM, the acceleration voltage is preferably 1 kV or more and 10 kV or less, and the magnification is preferably 1000 times or more and 7000 times or less, and in the case of TEM or STEM, the acceleration voltage is preferably 10 kV or more and 30 kV or less, and the magnification is preferably 50,000 times or more and 300,000 times or less. The thickness of each layer described below can be measured in the same manner as the thickness of the front transparent substrate layer 42 and the back transparent substrate layer 52 .

[0073] [Front-side anti-reflection functional layer and rear-side anti-reflection functional layer] Next, a description will be given of the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51. The front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 serve to impart a function of suppressing light reflection to the front-side antireflection layer 40 and the back-side antireflection layer 50, respectively.

[0074] Furthermore, the front-side antireflection functional layer 41 may be a coating layer coated on the front-side transparent substrate layer 42, and the back-side antireflection functional layer 51 may be a coating layer coated on the back-side transparent substrate layer 52. In this way, since the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 are coating layers, the thicknesses of the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 can be easily controlled, and desired functions such as the light reflectance and total light transmittance of the transparent laminate film 30 can be easily controlled.

[0075] The front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 are preferably made of a cured material containing an acrylic monomer, which allows the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 to be formed with high uniformity even by processing in a short time.

[0076] Here, the front-side antireflection functional layer 41 includes the front-side refraction layer 43 and the front-side hard coat layer 44, as described above. Also, the back-side antireflection functional layer 51 includes the back-side refraction layer 53 and the back-side hard coat layer 54, as described above. The front-side hard coat layer 44 may be a coating layer coated on the front-side transparent substrate layer 42, and the front-side refraction layer 43 may be a coating layer coated on the front-side hard coat layer 44. Also, the back-side hard coat layer 54 may be a coating layer coated on the back-side transparent substrate layer 52, and the back-side refraction layer 53 may be a coating layer coated on the back-side hard coat layer 54. In this way, since the front-side refraction layer 43, the front-side hard coat layer 44, the back-side refraction layer 53, and the back-side hard coat layer 54 are coating layers, the thickness of each layer can be easily controlled, and the desired functions such as the light reflectance and total light transmittance of the transparent laminated film 30, and in some cases, the color can be easily controlled.

[0077] Next, the front surface hard coat layer 44 and the back surface hard coat layer 54 will be described.

[0078] {Front hard coat layer and rear hard coat layer} The front hard coat layer 44 and the back hard coat layer 54 serve to improve the scratch resistance of the front antireflection layer 40 and the back antireflection layer 50. Here, the hard coat refers to a layer having a hardness of "H" or more in the pencil hardness test specified in JIS K5600-5-4:1999. The front hard coat layer 44 and the back hard coat layer 54 can be formed, for example, from a hard coat layer coating liquid containing a curable resin composition. Examples of the curable resin composition include a thermosetting resin composition or an ionizing radiation curable resin composition, and from the viewpoint of scratch resistance, an ionizing radiation curable resin composition is preferred.

[0079] The thermosetting resin composition is a composition that contains at least a thermosetting resin, and is a resin composition that is cured by heating. Examples of the thermosetting resin include acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicone resin, etc. In the thermosetting resin composition, a curing agent is added to the curable resin as necessary.

[0080] The ionizing radiation curable resin composition is a composition containing a compound having an ionizing radiation curable functional group (hereinafter, also referred to as "ionizing radiation curable compound"). Examples of the ionizing radiation curable functional group include ethylenically unsaturated bond groups such as (meth)acryloyl group, vinyl group, and allyl group, as well as epoxy group and oxetanyl group. As the ionizing radiation curable compound, a compound having an ethylenically unsaturated bond group is preferred, a compound having two or more ethylenically unsaturated bond groups is more preferred, and among them, a polyfunctional (meth)acrylate-based compound having two or more ethylenically unsaturated bond groups is even more preferred. As the polyfunctional (meth)acrylate-based compound, either a monomer or an oligomer can be used. Note that, the ionizing radiation means an electromagnetic wave or a charged particle beam that has an energy quantum capable of polymerizing or crosslinking molecules, and usually ultraviolet light (UV) or an electron beam (EB) is used, but other electromagnetic waves such as X-rays and gamma rays, charged particle beams such as alpha rays and ion beams can also be used.

[0081] Among the polyfunctional (meth)acrylate compounds, examples of bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxy diacrylate, bisphenol A tetrapropoxy diacrylate, and 1,6-hexanediol diacrylate. Examples of trifunctional or higher (meth)acrylate monomers include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol tetra(meth)acrylate, and isocyanuric acid-modified tri(meth)acrylate. The (meth)acrylate monomers may have a part of the molecular skeleton modified, and those modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol, and the like may also be used.

[0082] In addition, examples of the polyfunctional (meth)acrylate oligomer include acrylate polymers such as urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate. The urethane (meth)acrylate is obtained, for example, by reacting a polyhydric alcohol and an organic diisocyanate with a hydroxy (meth)acrylate. In addition, preferred epoxy (meth)acrylates are (meth)acrylates obtained by reacting trifunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with (meth)acrylic acid, (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with polybasic acids and (meth)acrylic acid, and (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with phenols and (meth)acrylic acid. The above ionizing radiation curable compounds can be used alone or in combination of two or more.

[0083] When the ionizing radiation curable compound is an ultraviolet curable compound, the ionizing radiation curable composition preferably contains additives such as a photopolymerization initiator and a photopolymerization accelerator. The photopolymerization initiator may be one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler's ketone, benzoin, benzyl methyl ketal, benzoyl benzoate, α-acyloxime ester, thioxanthones, etc. These photopolymerization initiators preferably have a melting point of 100°C or higher. By setting the melting point of the photopolymerization initiator to 100°C or higher, it is possible to prevent the residual photopolymerization initiator from sublimating due to heat during the transparent conductive film formation or crystallization process, thereby preventing the reduction in resistance of the transparent conductive film from being impaired. The same applies when using a photopolymerization initiator in the high refractive index layer and the low refractive index layer described later. The photopolymerization accelerator can reduce polymerization inhibition caused by air during curing and increase the curing speed, and examples of the accelerator include one or more types selected from p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, etc.

[0084] The thickness of the front hard coat layer 44 and the back hard coat layer 54 is preferably in the range of 0.1 μm to 100 μm, and more preferably in the range of 0.8 μm to 20 μm. If the thickness of the front hard coat layer 44 and the back hard coat layer 54 is within the above range, sufficient hard coat performance is obtained, and cracks and the like do not occur when subjected to external impact, and the layer is not easily broken.

[0085] The refractive index of the front hard coat layer 44 and the back hard coat layer 54 is preferably smaller than that of the front high refractive index layer 46 and the back high refractive index layer 56, more preferably 1.45 to 1.70, and even more preferably 1.45 to 1.60. If the refractive index of the front hard coat layer 44 and the back hard coat layer 54 is in such a range, the front hard coat layer 44 and the back hard coat layer 54 each play the role of a medium refractive index layer. This enables the interference action of the three layers of the front hard coat layer 44, the front high refractive index layer 46, and the front low refractive index layer 45, and the interference action of the three layers of the back hard coat layer 54, the back high refractive index layer 56, and the back low refractive index layer 55. Therefore, the reflection of light can be effectively suppressed. In addition, from the viewpoint of suppressing interference fringes, it is preferable to reduce the difference between the refractive index of the front hard coat layer 44 and the back hard coat layer 54 and the refractive index of the front transparent substrate layer 42 and the back transparent substrate layer 52.

[0086] The means for imparting the role of a medium refractive index layer to the front hard coat layer 44 and the back hard coat layer 54 include a means for blending a resin with a high refractive index into the hard coat layer coating solution and a means for blending particles with a high refractive index. When particles with a high refractive index are blended, whitening or coating defects may occur due to aggregation of the particles, so the former means (blending a resin with a high refractive index) is preferred. Examples of resins with a high refractive index include those obtained by introducing groups containing sulfur, phosphorus, or bromine, or aromatic rings, into the above-mentioned thermosetting resins or ionizing radiation curable compounds. As particles with a high refractive index, the same high refractive index particles as those used in the front high refractive index layer 46 and the back high refractive index layer 56 described later can be used.

[0087] The refractive index of each layer, such as the front hard coat layer 44 and the back hard coat layer 54, can be calculated, for example, by fitting a reflection spectrum measured by a reflection photometer to a reflection spectrum calculated from an optical model of a multilayer thin film using Fresnel coefficients.

[0088] The front surface hard coat layer 44 and the back surface hard coat layer 54 can be formed by preparing a coating liquid for forming a hard coat layer using the above-mentioned curable resin composition, additives such as an ultraviolet absorber and a leveling agent which are blended as necessary, and a dilution solvent, applying the coating liquid onto a transparent substrate by a conventionally known coating method, drying the coating liquid, and curing the coating liquid by irradiation with ionizing radiation as necessary.

[0089] {Front and rear refractive layers} Next, the front refraction layer 43 and the back refraction layer 53 will be described. The front refraction layer 43 and the back refraction layer 53 play a role in reducing the light reflectance of the front antireflection layer 40 and the back antireflection layer 50. As described above, the front refraction layer 43 includes the front low refraction layer 45 and the front high refraction layer 46. Also, as described above, the back refraction layer 53 includes the back low refraction layer 55 and the back high refraction layer 56. Here, the front low refraction layer 45 and the back low refraction layer 55 will be described first. Note that, as shown in FIG. 4A, FIG. 4B, etc., when the front refraction layer 43 and the back refraction layer 53 are each composed of a single layer, the front refraction layer 43 may be composed only of the front low refraction layer 45, and the back refraction layer 53 may be composed only of the back low refraction layer 55.

[0090] (Front low refractive index layer and rear low refractive index layer) The front surface low refractive index layer 45 and the back surface low refractive index layer 55 are layers provided on the front surface high refractive index layer 46 and the back surface high refractive index layer 56, and play a role of reducing the light reflectance of the front surface antireflection layer 40 and the back surface antireflection layer 50 by interference action using the difference in refractive index between the front surface high refractive index layer 46 and the back surface high refractive index layer 56. In order to make the front surface antireflection layer 40 and the back surface antireflection layer 50 have an ultra-low reflectance, the front surface low refractive index layer 45 and the back surface low refractive index layer 55 preferably have a refractive index of 1.26 or more and 1.40 or less, more preferably 1.28 or more and 1.38 or less, and even more preferably 1.30 or more and 1.32 or less. The lower the refractive index of the front surface low refractive index layer 45 and the back surface low refractive index layer 55, the lower the refractive index of the front surface antireflection layer 40 and the back surface antireflection layer 50 can be without increasing the refractive index of the front surface high refractive index layer 46 and the back surface high refractive index layer 56 so much. On the other hand, if the refractive index of the front surface low refractive index layer 45 and the back surface low refractive index layer 55 is too low, the strength of the front surface low refractive index layer 45 and the back surface low refractive index layer 55 tends to decrease. Therefore, by setting the refractive index of the front surface low refractive index layer 45 and the back surface low refractive index layer 55 in the above range, respectively, the amount of high refractive index particles to be described later in the front surface high refractive index layer 46 and the back surface high refractive index layer 56 can be reduced while maintaining the strength of the front surface low refractive index layer 45 and the back surface low refractive index layer 55, which is preferable in terms of suppressing color and whitening. In addition, the thickness of the front surface low refractive index layer 45 and the back surface low refractive index layer 55 is preferably 80 nm or more and 120 nm, more preferably 85 nm or more and 110 nm, and even more preferably 90 nm or more and 105 nm. In addition, the front surface low refractive index layer 45 and the back surface low refractive index layer 55 may be formed of a plurality of layers that satisfy the above refractive index ranges, but from the viewpoint of cost-effectiveness, two layers or less are preferable, and a single layer is more preferable.

[0091] The method of forming the front low refractive index layer 45 and the back low refractive index layer 55 can be roughly divided into a wet method and a dry method. Examples of the wet method include a method of forming the front low refractive index layer 45 and the back low refractive index layer 55 by a sol-gel method using a metal alkoxide or the like, a method of forming the front low refractive index layer by coating a resin having a low refractive index such as a fluororesin, and a method of forming the front low refractive index layer by coating a coating liquid for forming the front low refractive index layer in which low refractive index particles are contained in a resin composition. Examples of the dry method include a method of selecting particles having a desired refractive index from the low refractive index particles described later and forming the front low refractive index layer by a physical vapor deposition method or a chemical vapor deposition method. The wet method is excellent in terms of production efficiency, and in the present embodiment, it is preferable to form the front low refractive index layer by a coating liquid for forming the front low refractive index layer in which low refractive index particles are contained in a resin composition among the wet methods.

[0092] Low refractive index particles are preferably used for the purpose of lowering the refractive index, i.e., improving the antireflection properties. Either inorganic particles such as silica or magnesium fluoride, or organic particles can be used without restriction. From the viewpoint of further improving the antireflection properties and ensuring good surface hardness, however, particles having a structure in which the particles themselves have voids are preferably used.

[0093] Particles having a structure in which they themselves have voids have fine voids inside, and for example, because they are filled with a gas such as air with a refractive index of 1.0, their own refractive index is low. Examples of such particles having voids include inorganic or organic porous particles and hollow particles, such as porous silica, hollow silica particles, and porous polymer particles and hollow polymer particles using acrylic resin. A preferred example of inorganic particles is silica particles having voids prepared using the technology disclosed in JP-A-2001-233611. A preferred example of organic particles is hollow polymer particles prepared using the technology disclosed in JP-A-2002-80503. The above-mentioned silica or porous silica having voids has a refractive index in the range of 1.18 to 1.44, which is lower than that of general silica particles having a refractive index of about 1.45, and is therefore preferable from the viewpoint of lowering the refractive index of the front surface low refractive index layer 45 and the back surface low refractive index layer 55.

[0094] The hollow silica particles are particles that have the function of lowering the refractive index of the front low refractive index layer 45 and the back low refractive index layer 55 while maintaining the coating strength of the layers. The hollow silica particles used in this embodiment are silica particles having a structure with a cavity inside. The hollow silica particles are silica particles whose refractive index decreases in inverse proportion to the occupancy rate of the internal cavity compared to the inherent refractive index of the silica particles (refractive index n=about 1.45). Therefore, the refractive index of the hollow silica particles as a whole is 1.18 or more and 1.44 or less.

[0095] The hollow silica particles are not particularly limited, and examples thereof include particles having an outer shell and a porous or hollow interior, and silica particles prepared using the techniques disclosed in JP-A-6-330606, JP-A-7-013137, JP-A-7-133105, and JP-A-2001-233611.

[0096] The average particle diameter of the primary particles of the low refractive index particles is preferably 5 nm or more and 200 nm or less, more preferably 5 nm or more and 100 nm or less, and even more preferably 10 nm or more and 80 nm or less. If the average particle diameter of the primary particles is within the above range, the transparency of the front surface low refractive index layer 45 and the back surface low refractive index layer 55 is not impaired, and a good particle dispersion state is obtained. In particular, hollow particles are used as the low refractive index particles, and the average particle diameter of the hollow particles is 70 nm or more and 80 nm or less, which is preferable in that it can increase the porosity and reduce the refractive index while maintaining a shell thickness that does not cause insufficient strength, and is also excellent in balance with the ideal thickness (about 100 nm) of the front surface low refractive index layer 45 and the back surface low refractive index layer 55 for reducing reflectance.

[0097] The low refractive index particles used in this embodiment are preferably surface-treated. As the surface treatment of the low refractive index particles, a surface treatment using a silane coupling agent is more preferable, and among these, a surface treatment using a silane coupling agent having a (meth)acryloyl group is preferable. By subjecting the low refractive index particles to a surface treatment, the affinity with the binder resin described below is improved, the dispersion of the particles becomes uniform, and the aggregation of the particles is less likely to occur, so that the decrease in the transparency of the front surface low refractive index layer 45 and the back surface low refractive index layer 55 due to the increase in particle size caused by aggregation, the applicability of the layer forming composition, and the decrease in the coating strength of the composition are suppressed.

[0098] In addition, when the silane coupling agent has a (meth)acryloyl group, the silane coupling agent has ionizing radiation curing properties, and therefore easily reacts with the binder resin described below, so that the low refractive index particles are well fixed to the binder resin in the coating film of the layer-forming composition. That is, the low refractive index particles function as a crosslinking agent in the binder resin. This provides a tightening effect on the entire coating film, and makes it possible to impart excellent surface hardness to the front low refractive index layer 45 and the back low refractive index layer 55 while retaining the inherent flexibility of the binder resin. Therefore, the front low refractive index layer 45 and the back low refractive index layer 55 are deformed by making use of their own flexibility, and therefore have the ability to absorb and restore external impacts, so that the occurrence of scratches is suppressed, resulting in a high surface hardness with excellent scratch resistance.

[0099] Examples of silane coupling agents that are preferably used in the surface treatment of low refractive index particles include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 2-(meth)acryloxypropyltrimethoxysilane, and 2-(meth)acryloxypropyltriethoxysilane.

[0100] The content of the low refractive index particles in the front low refractive index layer 45 and the back low refractive index layer 55 is preferably 10 parts by mass or more and 250 parts by mass or less, more preferably 50 parts by mass or more and 200 parts by mass or less, and even more preferably 100 parts by mass or more and 180 parts by mass or less, relative to 100 parts by mass of the resin of the front low refractive index layer 45 and the back low refractive index layer 55, respectively. If the content of the low refractive index particles is within the above range, good anti-reflection properties and surface hardness can be obtained. In addition, the proportion of hollow particles and / or porous particles in the total low refractive index particles contained in the front low refractive index layer 45 and the back low refractive index layer 55 is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 80% by mass or more and 95% by mass or less.

[0101] The resin composition contained in the layer-forming coating liquid may be a curable resin composition. The curable resin composition may be the same as that exemplified in the description of the front hard coat layer 44 and the back hard coat layer 54, and an ionizing radiation curable resin composition is preferred. In addition, a fluorine-containing polymer or a fluorine monomer that exhibits a low refractive index by itself is also preferably used as the resin composition. The fluorine-containing polymer is a polymer of a polymerizable compound that contains at least a fluorine atom in the molecule, and is preferred in that it can impart antifouling properties and slip properties. The fluorine-containing polymer is preferably one that has a reactive group in the molecule and functions as a curable resin composition, and more preferably one that has an ionizing radiation curable reactive group and functions as an ionizing radiation curable resin composition.

[0102] As the fluorine-containing polymer, those containing silicon together with fluorine are preferred in order to not only repel dirt on the surface of the low refractive index layer, but also to impart wipeability to the repelled dirt, and for example, silicone-containing vinylidene fluoride copolymers in which a silicone component is contained in a copolymer are preferred. In this case, examples of the silicone component include (poly)dimethylsiloxane, (poly)diethylsiloxane, (poly)diphenylsiloxane, (poly)methylphenylsiloxane, alkyl-modified (poly)dimethylsiloxane, azo-group-containing (poly)dimethylsiloxane, dimethylsilicone, phenylmethylsilicone, alkyl-aralkyl-modified silicone, fluorosilicone, polyether-modified silicone, fatty acid ester-modified silicone, methyl hydrogen silicone, silanol-group-containing silicone, alkoxy-group-containing silicone, phenol-group-containing silicone, methacryl-modified silicone, acrylic-modified silicone, amino-modified silicone, carboxylic acid-modified silicone, carbinol-modified silicone, epoxy-modified silicone, mercapto-modified silicone, fluorine-modified silicone, polyether-modified silicone, etc. Among them, those having a dimethylsiloxane structure are preferred.

[0103] The front surface low refractive index layer 45 and the back surface low refractive index layer 55 can be formed, for example, by preparing a layer-forming coating liquid using low refractive index particles, a resin composition, and additives such as an ultraviolet absorber and a leveling agent that are blended as necessary, and a diluting solvent, and then coating the coating liquid on the front surface high refractive index layer 46 or the back surface high refractive index layer 56 by a conventionally known coating method, drying, and curing by exposure to ionizing radiation as necessary.

[0104] (Front high refractive index layer and rear high refractive index layer) The front surface high refractive index layer 46 and the back surface high refractive index layer 56 serve to reduce the light reflectance of the front surface antireflection layer 40 and the back surface antireflection layer 50 through an interference effect, utilizing the difference in refractive index between them and the front surface low refractive index layer 45 and the back surface low refractive index layer 55. The front surface high refractive index layer 46 and the back surface high refractive index layer 56 can each be formed from a layer-forming coating liquid containing, for example, a curable resin composition and high refractive index particles.

[0105] From the viewpoint of making the front-surface antireflection layer 40 and the back-surface antireflection layer 50 have an ultra-low reflectance, it is preferable that the refractive index of the front-surface high refractive index layer 46 and the back-surface high refractive index layer 56 be high, but a large amount of high refractive index particles is required to increase the refractive index, which leads to aggregation of the high refractive index particles and causes whitening. For this reason, the refractive index is preferably 1.55 to 1.85, and more preferably 1.56 to 1.70. The thickness of the front-surface high refractive index layer 46 and the back-surface high refractive index layer 56 is preferably 200 nm or less, and more preferably 50 nm or more and 180 nm or less. When the front-surface high refractive index layer 46 and the back-surface high refractive index layer 56 each have a two-layer structure described later, it is preferable that the total thickness of the two layers satisfy the above value. The front-surface high refractive index layer 46 and the back-surface high refractive index layer 56 may be formed of a plurality of layers that satisfy the above-mentioned refractive index range, but from the viewpoint of cost-effectiveness, two layers or less are preferable, and a single layer is more preferable.

[0106] Examples of high refractive index particles include antimony pentoxide (1.79), zinc oxide (1.90), titanium oxide (2.3 to 2.7), cerium oxide (1.95), tin-doped indium oxide (1.95 to 2.00), antimony-doped tin oxide (1.75 to 1.85), yttrium oxide (1.87), and zirconium oxide (2.10). The above parentheses indicate the refractive index of the material of each particle. Among these high refractive index particles, those with a refractive index of more than 2.0 are preferred from the viewpoint of achieving the above-mentioned suitable refractive index with a small amount of addition. In addition, conductive high refractive index particles such as antimony pentoxide, tin-doped indium oxide (ITO), and antimony-doped tin oxide (ATO) have free electrons whose plasma frequency is in the near-infrared region, and due to the plasma oscillation of the free electrons, some light in the visible light region is absorbed or reflected, making it difficult to suppress the color. For this reason, it is preferable that the high refractive index particles are non-conductive. For the above reasons, titanium oxide and zirconium oxide are suitable among the high refractive index particles exemplified above, and zirconium oxide is the most suitable from the viewpoint of high durability and stability such as light resistance, etc. If it is desired to impart antistatic properties to the front-surface antireflection layer 40 and the back-surface antireflection layer 50, it is preferable that the front-surface high refractive index layer 46 and the back-surface high refractive index layer 56 have a two-layer structure as described below, and one of the layers contains conductive high refractive index particles.

[0107] The average particle size of the primary particles of the high refractive index particles is preferably 5 nm to 200 nm, more preferably 5 nm to 100 nm, and even more preferably 10 nm to 80 nm. The average particle size of the primary particles of the high refractive index particles and the low refractive index particles described later can be calculated by the following steps (1) to (3). (1) Surface images of the particles themselves, or of a particle dispersion coated and dried on a transparent substrate, are taken using SEM, TEM, or STEM. (2) Randomly extract 10 particles from the surface image, measure the long and short diameters of each particle, and calculate the particle diameter of each particle from the average of the long and short diameters. Note that the longest diameter is the longest diameter on the screen, and the short diameter is the distance between the two points where a line segment perpendicular to the midpoint of the line segment constituting the long diameter intersects with the particle. (3) The same procedure is carried out five times on separate images of the same sample, and the value obtained by averaging the particle sizes of a total of 50 particles is regarded as the average particle size. In addition, when calculating the average particle size of particles, if the calculated average particle size is on the order of μm, it is preferable to use SEM, and if the calculated average particle size is on the order of nm, it is preferable to use TEM or STEM. In the case of SEM, the acceleration voltage is preferably 1 kV to 10 kV and the magnification is preferably 1000 to 7000 times, and in the case of TEM or STEM, the acceleration voltage is preferably 10 kV to 30 kV and the magnification is preferably 50,000 to 300,000 times.

[0108] From the viewpoint of a balance between increasing the refractive index, suppressing color tone, and suppressing whitening, the content of the high refractive index particles is preferably 30 parts by mass or more and 400 parts by mass or less, more preferably 50 parts by mass or more and 200 parts by mass or less, and even more preferably 80 parts by mass or more and 150 parts by mass or less, relative to 100 parts by mass of the curable resin composition.

[0109] The front surface high refractive index layer 46 and the rear surface high refractive index layer 56 are preferably dispersion stabilized to suppress excessive aggregation of the high refractive index particles. For example, a means for dispersion stabilization is a means for adding another high refractive index particle having a smaller surface charge amount than the base high refractive index particle. According to this means, the base high refractive index particles are appropriately gathered around the other high refractive index particles, and excessive aggregation of the base high refractive index particles can be suppressed. Another means for dispersion stabilization is to use high refractive index particles that have been surface-treated, or to add a dispersant to the layer-forming coating liquid.

[0110] The curable resin composition for forming the front surface high refractive index layer 46 and the back surface high refractive index layer 56 may be The same materials as those exemplified in the explanation of the front hard coat layer 44 and the back hard coat layer 54 can be used, and an ionizing radiation curable resin composition is preferable. In order to obtain the above-mentioned refractive index without adding an excessive amount of high refractive index particles, it is preferable to use a curable resin composition with a high refractive index. The refractive index of the curable resin composition is preferably about 1.54 to 1.70.

[0111] Here, as described above, the surface high refractive index layer 46 may include a first surface high refractive index layer 47 and a second surface high refractive index layer 48. In this case, it is preferable that the refractive index of the first surface high refractive index layer 47 is higher than that of the second surface high refractive index layer 48. This makes it possible to increase the refractive index difference between the surface high refractive index layer 46 and the surface low refractive index layer 45, thereby lowering the reflectance of the surface antireflection layer 40, and to reduce the refractive index difference between the surface high refractive index layer 46 and the surface hard coat layer 44, thereby suppressing the occurrence of interference fringes.

[0112] As described above, the back surface high refractive index layer 56 may include a first back surface high refractive index layer 57 and a second back surface high refractive index layer 58. In this case, similar to the front surface high refractive index layer 46, the refractive index of the first back surface high refractive index layer 57 is preferably higher than the refractive index of the second back surface high refractive index layer 58. This makes it possible to increase the refractive index difference between the back surface high refractive index layer 56 and the back surface low refractive index layer 55, thereby lowering the reflectance of the back surface antireflection layer 50 and reducing the refractive index difference between the back surface high refractive index layer 56 and the back surface hard coat layer 54, thereby suppressing the occurrence of interference fringes.

[0113] In addition, when the front surface high refractive index layer 46 and the rear surface high refractive index layer 56 are each made of two layers, the refractive index of the first front surface high refractive index layer 47 and the first rear surface high refractive index layer 57 is preferably 1.60 or more and 1.85 or less, and the refractive index of the second front surface high refractive index layer 48 and the second rear surface high refractive index layer 58 is preferably 1.55 or more and 1.70 or less. Furthermore, in the above two-layer structure, it is preferable that one layer contains conductive high refractive index particles and the other layer contains non-conductive high refractive index particles, and that the thickness of the layer containing conductive high refractive index particles is < the thickness of the layer containing non-conductive high refractive index particles. By adopting this structure, it is possible to impart antistatic properties while suppressing the amount of conductive high refractive index particles added, which may cause coloring. In addition, the conductive high refractive index particles are preferable in that they can be networked within the layer to impart antistatic properties with a small amount of addition, and thus can suppress coloring and whitening.

[0114] The front surface high refractive index layer 46 and the back surface high refractive index layer 56 can be formed by preparing a layer-forming coating liquid using high refractive index particles, a curable resin composition, and additives such as an ultraviolet absorber and a leveling agent which are blended as necessary, and a diluting solvent, and applying the coating liquid onto the front surface hard coat layer 44 or the back surface hard coat layer 54 by a conventionally known coating method, drying the coating liquid, and curing the coating liquid by irradiation with ionizing radiation as necessary.

[0115] [Transparent adhesive layer, first transparent adhesive layer and second transparent adhesive layer] The transparent adhesive layers, such as the transparent adhesive layer 31, the first transparent adhesive layer 31a, and the second transparent adhesive layer 31b, are layers for bonding the front-surface antireflection layer 40, the back-surface antireflection layer 50, the core layer 32, and the like to each other. Here, the "transparent adhesive layer" in this specification is a concept that includes a transparent adhesive layer. The transparent adhesive layer can be formed using various substances that are generally used as adhesives. Examples include acrylic adhesives, urethane adhesives, olefin adhesives, rubber adhesives, silicone adhesives, and polyester adhesives. Acrylic adhesives that have high transparency and can increase adhesive strength are preferred.

[0116] Each of the above adhesives may contain various functionalizing agents, stabilizers, etc., within the range that does not impair transparency. Also, a tackifier may be blended to increase adhesive strength. Also, a crosslinking agent such as isocyanate, epoxy, or a compound containing a double bond may be used according to each resin to form a crosslinked structure.

[0117] The transparent adhesive layer can also be formed using a type of adhesive (OCA, Optical Clear Adhesive) that is laminated with a release film on both sides. Commercially available products can also be used, such as the optically transparent adhesive sheet LUCIACS series (manufactured by Nitto Denko Corporation), highly transparent double-sided tape 5400A series (manufactured by Sekisui Chemical Co., Ltd.), optical adhesive sheet Opteria series (manufactured by Lintec Corporation), SANCUARY series (manufactured by San-A Kaken Co., Ltd.), optically transparent adhesive OAD series (manufactured by Toyo Hozai Co., Ltd.), optical coreless double-sided tape RA series (manufactured by Sumiron Co., Ltd.), and Panaclean series PD-S1 (manufactured by Panac Corporation). The adhesive strength of these adhesives is generally 10N / 25mm or more.

[0118] The thickness of the transparent adhesive layer is not particularly limited, but is preferably, for example, 2 μm or more and 200 μm or less. If the thickness of the transparent adhesive layer is 2 μm or more, the front-surface antireflection layer 40 and the back-surface antireflection layer 50 can be reliably bonded, and if the thickness of the transparent adhesive layer is 200 μm or less, transparency (light transmittance) can be maintained. The lower limit of the thickness of the transparent adhesive layer is more preferably 5 μm or more, 10 μm or more, or 15 μm or more, and the upper limit is more preferably 150 μm or less, 160 μm or less, or 170 μm or less.

[0119] The method for forming the transparent adhesive layer is not particularly limited, and a known method used for manufacturing adhesive tapes, etc. can be adopted. Specifically, the transparent adhesive layer can be formed by any method such as a method of applying a coating of an adhesive composition obtained by dissolving or dispersing each component forming the transparent adhesive layer in an appropriate organic solvent or water to the surface of a substrate, drying and curing the coating, a method of applying each component forming the transparent adhesive layer, a double bond-containing monomer, an oligomer, a crosslinking agent, etc. to a substrate without a solvent, and then crosslinking the coating with radiation, etc., or an extrusion lamination method.

[0120] When using OCA, a transparent adhesive layer can be formed by peeling off the release film on the light release side of the OCA and attaching the adhesive surface to a substrate.

[0121] [Core layer] The core layer 32 plays a role in supporting the front-surface antireflection layer 40 and the back-surface antireflection layer 50. The core layer 32 preferably contains polyethylene terephthalate. Note that the material of the core layer 32 may be the same as the material of the front-surface transparent substrate layer 42 and the back-surface transparent substrate layer 52 described above.

[0122] The thickness of the core layer 32 is not particularly limited and may be appropriately selected depending on the application. The thickness of the core layer 32 may be about 5 μm or more and 130 μm or less, and is preferably 10 μm or more and 100 μm or less in consideration of durability, handling, etc.

[0123] [Print layer] The printed layer 33 is a layer on which a pattern or the like is printed, and is a layer for improving the design of the transparent laminate film 30. The printed layer 33 may be an ink composition obtained by adjusting an ink composition by adding one or more of ordinary ink vehicles as the main component, optionally adding one or more of plasticizers, stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, fillers, and other additives as necessary, and further adding a colorant such as a dye or pigment, and thoroughly kneading with a solvent, a diluent, etc. Examples of such ink vehicles include linseed oil, tung oil, soybean oil, hydrocarbon oil, rosin, rosin ester, rosin-modified resin, shellac, alkyd resin, phenolic resin, maleic acid resin, natural resin, hydrocarbon resin, polyvinyl chloride resin, polyacetic acid resin, polystyrene resin, polyvinyl butyral resin, acrylic or methacrylic resin, polyamide resin, polyester resin, polyurethane resin, epoxy resin, urea resin, melamine resin, aminoalkyd resin, nitrocellulose, ethylcellulose, chlorinated rubber, cyclized rubber, and others, and one or more of these may be used in combination. The printing method may be gravure printing, letterpress printing, screen printing, transfer printing, flexographic printing, inkjet printing, or other printing methods.

[0124] The transparent laminate film 30 described above preferably has a thickness of 60 μm or more and 500 μm or less. By making the transparent laminate film 30 thicker than or equal to 60 μm, the film has a stiffness and strength sufficient to maintain the shape of the shield portion 30A, and therefore can effectively prevent droplets of the wearer H's saliva, etc. from adhering to the face of another person, and can effectively prevent droplets of the wearer H's saliva, etc. from adhering to the face of the wearer H. In addition, by making the transparent laminate film 30 thicker than or equal to 500 μm, the transparency of the transparent laminate film 30 can be improved.

[0125] Moreover, the above-mentioned transparent laminate film 30 preferably has a restoring function. This allows the transparent laminate film 30 to restore to a flat shape when folded or rolled. Here, the restoring function means a function that allows an object (the transparent laminate film 30) to restore to a flat shape without forming creases even after the object is bent for a certain period of time.

[0126] In the above-mentioned transparent laminate film 30, in the region where the printed layer 33 is not provided, the luminous reflectance Y value is 0.0% or more and 2.0% or less, and preferably 0.1% or more and 1.0% or less. In the region where the printed layer 33 is not provided, the luminous reflectance Y value is 0.0% or more and 2.0% or less, so that the region where the printed layer 33 is not provided in the transparent laminate film 30 can be made inconspicuous, and the printed layer 33 can be made conspicuous. In this way, by making the region where the printed layer 33 is not provided inconspicuous, it is possible to give the observer who visually recognizes the printed layer 33 an impression that the character or the like formed by the printed layer 33 is floating in the air. In addition, depending on the angle at which the observer visually recognizes the printed layer 33, it is possible to give the observer an impression that the character or the like is printed directly on the face F. The face shield 10 according to this embodiment can display a design different from the conventional one. Therefore, the design of the face shield can be improved.

[0127] Here, the luminous reflectance Y value can be measured by the following method. First, light is irradiated onto the front surface 301 or the back surface 302 of the transparent laminate film 30 so that the incident angle is 5°. Then, the luminous reflectance Y value can be measured based on the specularly reflected light of the incident light. Here, in this specification, the luminous reflectance Y value refers to the luminous reflectance Y value of the CIE1931 standard color system.

[0128] In addition, in the transparent laminate film 30, in the area where the printed layer 33 is not provided, the reflectance of light having a wavelength of 550 nm is preferably 2% or less, and the total light transmittance (JISK7361-1:1997) is preferably 90% or more. Furthermore, the transparent laminate film 30 more preferably has a total light transmittance of 92% or more. Furthermore, the transparent laminate film 30 preferably has a haze (JISK7136:2000) of 3.0% or less, more preferably 2.5% or less, and even more preferably 2.0% or less.

[0129] The transparent laminate film 30 described above preferably has a transmittance of 1% or less in the ultraviolet region having a wavelength of 380 nm or less in the area not provided with the printed layer 33. This makes it possible to prevent the wearer H from getting sunburned even when the wearer H wearing the face shield 10 works in an environment exposed to direct sunlight.

[0130] In the above-mentioned transparent laminate film 30, the arithmetic mean roughness Ra (JIS B0601:1994) of the front surface 301 and the back surface 302 is preferably 10 nm or less, more preferably 1 nm or more and 8 nm or less. The ten-point mean roughness Rz (JIS B0601:1994) of the front surface 301 and the back surface 302 is preferably 160 nm or less, more preferably 50 nm or more and 155 nm or less. When Ra and Rz are in the above ranges, the film has smoothness and improves scratch resistance.

[0131] Method for producing transparent laminate film, transparent laminate film with protective film, and face shield Next, a method for producing the transparent laminate film, the transparent laminate film with a protective film, and the face shield according to the present embodiment will be described. First, a method for producing the transparent laminate film 30 will be described.

[0132] First, the front surface antireflection layer 40 is prepared. In this case, for example, a resin film constituting the front surface transparent substrate layer 42 is first prepared. Next, a coating liquid for forming a hard coat layer is applied onto the resin film, dried and irradiated with ultraviolet light to form a front surface hard coat layer 44. Next, a coating liquid for forming a high refractive index layer is applied onto the front surface hard coat layer 44, dried and irradiated with ultraviolet light to form a front surface high refractive index layer 46. Next, a coating liquid for forming a low refractive index layer is applied onto the front surface high refractive index layer 46, dried and irradiated with ultraviolet light to form a front surface low refractive index layer 45. In this manner, the front surface antireflection layer 40 can be obtained.

[0133] In addition, the back surface antireflection layer 50 is prepared. In this case, for example, first, a resin film constituting the back surface transparent substrate layer 52 is prepared. Next, a coating liquid for forming a hard coat layer is applied onto the resin film, dried and irradiated with ultraviolet light to form a back surface hard coat layer 54. Next, a coating liquid for forming a high refractive index layer is applied onto the back surface hard coat layer 54, dried and irradiated with ultraviolet light to form a back surface high refractive index layer 56. Next, a coating liquid for forming a low refractive index layer is applied onto the back surface high refractive index layer 56, dried and irradiated with ultraviolet light to form a back surface low refractive index layer 55. In this manner, the back surface antireflection layer 50 can be obtained.

[0134] Furthermore, the core layer 32 having the printed layer 33 is produced. In this case, for example, first, a polyethylene terephthalate film is prepared as the core layer 32. Next, the printed layer 33 is formed on the core layer 32 by, for example, gravure printing or the like.

[0135] Then, the front-surface antireflection layer 40 and the core layer 32 are bonded to each other via the first transparent adhesive layer 31a, and the core layer 32 and the rear-surface antireflection layer 50 are bonded to each other via the second transparent adhesive layer 31b to produce the transparent laminate film 30. In this manner, the transparent laminate film 30 can be produced.

[0136] Next, a surface protective film 61 is attached to the surface 301 of the obtained transparent laminate film 30, and a back protective film 62 is attached to the back surface 302. At this time, the surface protective film 61 and the back protective film 62 may each include a bonding layer (not shown) and be attached to the transparent laminate film 30 by this bonding layer. In this manner, the transparent laminate film 60 with the protective film can be produced. Note that the surface protective film 61 and the back protective film 62 may be attached separately to the front surface antireflection layer 40 and the back surface antireflection layer 50, respectively, before the front surface antireflection layer 40 and the back surface antireflection layer 50 are bonded to each other via the transparent adhesive layer 31.

[0137] Next, the face shield 10 is produced.

[0138] At this time, the protective film-attached transparent laminate film 60 is first processed into a predetermined shape. In this case, the protective film-attached transparent laminate film 60 may be processed by punching using a die, cutting using a drill, or laser processing using a laser. From the viewpoint of processing speed and productivity, the protective film-attached transparent laminate film 60 is preferably processed by punching.

[0139] Next, the front protective film 61 and the back protective film 62 are removed from the protective film-attached transparent laminate film 60 that has been processed into a predetermined shape, thereby obtaining the transparent laminate film 30 that has been processed into a predetermined shape.

[0140] Next, the transparent laminate film 30 processed into a predetermined shape is attached to the holding member 20, thereby obtaining the face shield 10 shown in FIG.

[0141] As described above, according to the present embodiment, the transparent laminate film 30 includes at least the core layer 32 and the printed layer 33 provided on one surface of the core layer 32 and covering a part of the core layer 32. In addition, in the region where the printed layer 33 is not provided, the luminous reflectance Y value is 0.0% or more and 2.0% or less. This makes it possible to make the region where the printed layer 33 is not provided in the transparent laminate film 30 less noticeable, and to make the printed layer 33 more noticeable. In this way, by making the region where the printed layer 33 is not provided less noticeable, it is possible to give an impression to an observer who visually recognizes the printed layer 33 that the character or the like formed by the printed layer 33 is floating in the air. In addition, by making the luminous reflectance Y value 0.0% or more and 2.0% or less in the region where the printed layer 33 is not provided, it is possible to prevent the printed layer 33 from becoming difficult to see due to reflected light. Furthermore, depending on the angle at which the observer visually recognizes the printed layer 33, it is possible to give the observer the impression that the character or the like is directly printed on the face F. The face shield 10 according to the present embodiment can display a design different from the conventional design. This can improve the design of the face shield 10. In addition, since the printed layer 33 can be made to stand out, characters and symbol information can be clearly displayed on the face shield 10.

[0142] Furthermore, according to this embodiment, the transparent laminate film 30 has a reflectance of 2% or less for light with a wavelength of 550 nm and a total light transmittance of 90% or more in the area where the printed layer 33 is not provided. This makes it possible to make the area where the printed layer 33 is not provided even less noticeable. Also, the visibility of the face F of the wearer H can be improved.

[0143] Furthermore, according to this embodiment, the transmittance of ultraviolet light having a wavelength of 380 nm or less is 1% or less in the area not provided with the printed layer 33. This makes it possible to prevent the wearer H from getting sunburned even if the wearer H wearing the face shield 10 works in an environment exposed to direct sunlight.

[0144] Furthermore, according to this embodiment, the core layer 32 contains polyethylene terephthalate, which can improve the transparency of the core layer 32.

[0145] According to this embodiment, the transparent laminate film 30 further includes a front surface antireflection layer 40 that is provided on one side of the core layer 32 and forms the front surface 301, and a rear surface antireflection layer 50 that is provided on the other side of the core layer 32 and forms the rear surface 302. This can suppress the reflection of light incident from the front surface 301 side of the transparent laminate film 30 and the reflection of light incident from the rear surface 302 side of the transparent laminate film 30. That is, the visibility of the transparent laminate film 30 when viewed from the front surface 301 side can be improved, while the visibility of the transparent laminate film 30 when viewed from the rear surface 302 side can be improved. This can improve the visibility of the face F of the wearer H when viewing the wearer H wearing the face shield 10, for example. This can improve the visibility of the mouth of the wearer H, and can facilitate smooth communication between the wearer H and others. In addition, for example, a wearer H wearing a face shield 10 having a shield portion 30A made from a transparent laminate film 30 can be prevented from feeling discomfort or fatigue due to light reflected on the back surface 302 of the transparent laminate film 30.

[0146] Furthermore, the above-described transparent laminate film 30 can provide the following effects. No deterioration occurs even after 100 alcohol wipes and disinfection. Letters written with oil-based ink can be easily wiped off. Even if rubbed with a pencil 100 times, the surface is prevented from being scratched. Adherent fingerprints can be wiped off without leaving any traces. The fact that the above-mentioned effects can be achieved will be explained in the examples described later.

[0147] Moreover, according to this embodiment, the transparent laminate film 30 further includes a first transparent adhesive layer 31a that bonds the front-surface antireflection layer 40 and the core layer 32, and a second transparent adhesive layer 31b that bonds the core layer 32 and the back-surface antireflection layer 50. This makes it possible to easily produce the transparent laminate film 30 that includes the core layer 32 located between the front-surface antireflection layer 40 and the back-surface antireflection layer 50.

[0148] According to this embodiment, the first transparent adhesive layer 31a and the second transparent adhesive layer 31b each contain an acrylic adhesive. As a result, when a transparent laminate film 30 including the front-side antireflection layer 40 constituting the front surface 301, the back-side antireflection layer 50 constituting the back surface 302, and the core layer 32 is produced, the transparent laminate film 30 can maintain transparency and have good optical properties.

[0149] Moreover, according to this embodiment, the front-surface antireflection layer 40 has a front-surface antireflection functional layer 41 and a front-surface transparent substrate layer 42 arranged in this order from the front surface 301 to the back surface 302. Moreover, the back-surface antireflection layer 50 has a back-surface antireflection functional layer 51 and a back-surface transparent substrate layer 52 arranged in this order from the back surface 302 to the front surface 301. This makes it possible to impart to the front-surface antireflection layer 40 and the back-surface antireflection layer 50 a function of suppressing light reflection while increasing the overall strength of the front-surface antireflection layer 40 and the back-surface antireflection layer 50.

[0150] Furthermore, according to this embodiment, the front-side antireflection functional layer 41 is a coating layer coated on the front-side transparent substrate layer 42, and the back-side antireflection functional layer 51 is a coating layer coated on the back-side transparent substrate layer 52. In this way, since the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 are coating layers, the thicknesses of the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 can be easily controlled, and desired functions such as the light reflectance and total light transmittance of the transparent laminate film 30 can be easily controlled.

[0151] Furthermore, according to this embodiment, the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 are each made of a cured material containing an acrylic monomer. This makes it possible to form the front-side antireflection functional layer 41 and the back-side antireflection functional layer 51 with high uniformity even by processing in a short time. It is also possible to achieve both high hardness and good optical performance.

[0152] Moreover, according to this embodiment, the front-side antireflection functional layer 41 includes a front-side refraction layer 43 and a front-side hard coat layer 44, which are arranged in this order from the front side 301 to the back side 302. Moreover, the back-side antireflection functional layer 51 includes a back-side refraction layer 53 and a back-side hard coat layer 54, which are arranged in this order from the back side 302 to the front side 301. This makes it possible to reduce the light reflectance of the front-side antireflection layer 40 and the back-side antireflection layer 50 while improving the scratch resistance of the front-side antireflection layer 40 and the back-side antireflection layer 50.

[0153] According to this embodiment, the front hard coat layer 44 is a coating layer coated on the front transparent substrate layer 42, the front refraction layer 43 is a coating layer coated on the front hard coat layer 44, the back hard coat layer 54 is a coating layer coated on the back transparent substrate layer 52, and the back refraction layer 53 is a coating layer coated on the back hard coat layer 54. In this way, since the front refraction layer 43, the front hard coat layer 44, the back refraction layer 53, and the back hard coat layer 54 are coating layers, the thickness of each layer can be easily controlled, and the desired functions such as the light reflectance and total light transmittance of the transparent laminated film 30 can be easily controlled.

[0154] According to this embodiment, the front surface refraction layer 43 includes a front surface low refractive index layer 45 and a front surface high refractive index layer 46 arranged in this order from the front surface 301 to the rear surface 302. The rear surface refraction layer 53 includes a rear surface low refractive index layer 55 and a rear surface high refractive index layer 56 arranged in this order from the rear surface 302 to the front surface 301. This makes it possible to more effectively reduce the light reflectance of the front surface antireflection layer 40 and the rear surface antireflection layer 50 by an interference effect using the difference in refractive index between the front surface low refractive index layer 45 and the front surface high refractive index layer 46 and the difference in refractive index between the rear surface low refractive index layer 55 and the rear surface high refractive index layer 56.

[0155] According to this embodiment, the front surface high refractive index layer 46 includes a first front surface high refractive index layer 47 and a second front surface high refractive index layer 48, which are arranged in this order from the front surface 301 to the rear surface 302. The rear surface high refractive index layer 56 includes a first rear surface high refractive index layer 57 and a second rear surface high refractive index layer 58, which are arranged in this order from the rear surface 302 to the front surface 301. This makes it possible to more effectively reduce the light reflectance of the front surface antireflection layer 40 and the rear surface antireflection layer 50 by an interference effect using the difference in refractive index between the front surface low refractive index layer 45 and the front surface high refractive index layer 46 and the difference in refractive index between the rear surface low refractive index layer 55 and the rear surface high refractive index layer 56.

[0156] According to this embodiment, the refractive index of the first high refractive index layer 47 is higher than that of the second high refractive index layer 48. The refractive index of the first high refractive index layer 57 is higher than that of the second high refractive index layer 58. This makes it possible to increase the refractive index difference between the high refractive index layer 46 and the low refractive index layer 45, reduce the reflectance of the antireflection layer 40, and reduce the refractive index difference between the high refractive index layer 46 and the hard coat layer 44, thereby suppressing the occurrence of interference fringes. Furthermore, the refractive index difference between the high refractive index layer 56 and the low refractive index layer 55 can be increased, reduce the reflectance of the antireflection layer 50, and reduce the refractive index difference between the high refractive index layer 56 and the hard coat layer 54, thereby suppressing the occurrence of interference fringes.

[0157] Moreover, according to this embodiment, the front transparent substrate layer 42 and the back transparent substrate layer 52 contain triacetyl cellulose or polyethylene terephthalate. This can improve the transparency of the front transparent substrate layer 42 and the back transparent substrate layer 52. In addition, when the front transparent substrate layer 42 and the back transparent substrate layer 52 contain triacetyl cellulose, the flexibility of the front transparent substrate layer 42 and the back transparent substrate layer 52 can also be effectively improved. Therefore, when the shield part 30A made from the transparent laminated film 30 is folded, it is possible to suppress the occurrence of creases, scratches, etc. in the shield part 30A. In addition, even if the size of the shield part 30A is increased, it is possible to suppress the occurrence of creases, scratches, etc. in the shield part 30A. Therefore, since the front transparent substrate layer 42 and the back transparent substrate layer 52 contain triacetyl cellulose, it is possible to easily produce a large-sized shield part 30A.

[0158] Furthermore, according to the present embodiment, the transparent laminate film 30 has a restoring function, which allows the transparent laminate film 30 to be restored to a flat shape without causing creases, scratches, or the like, even when the transparent laminate film 30 is folded or rolled.

[0159] Moreover, according to this embodiment, the transparent laminate film 30 is used in a face shield 10 that protects the face F of the wearer H. This makes it possible to easily obtain a face shield 10 that can improve the visibility of the face F of the wearer H while suppressing the wearer H from feeling uncomfortable or tired. Furthermore, as described above, the face shield 10 according to this embodiment can display a design different from conventional designs, thereby improving the design of the face shield.

[0160] Furthermore, according to this embodiment, the transparent laminate film 60 with a protective film includes the transparent laminate film 30 according to this embodiment, a surface protective film 61 that protects the surface 301 of the transparent laminate film 30, and a back surface protective film 62 that protects the back surface 302 of the transparent laminate film 30. This makes it possible to prevent the surface 301 and the back surface 302 of the transparent laminate film 30 from being scratched when the transparent laminate film 30 is processed. In addition, it is possible to prevent the surface 301 and the back surface 302 from being contaminated by foreign matter or the like when the transparent laminate film 30 is shipped and transported.

[0161] In the above-described embodiment, the holding member 20 of the face shield 10 is a so-called eyeglass frame type, but the present invention is not limited to this. For example, the holding member 20 may be a so-called hair band type or headband type. In this case, as shown in FIG. 5, the holding member 20 may have a band 25 that circumferentially covers the head of the wearer H. The material of the band 25 may be an elastic body such as rubber, in addition to resin or cardboard. Furthermore, the holding member 20 may have a protective member 26 that is attached to the band 25 and abuts against the forehead of the wearer H. The protective member 26 preferably contains a material having cushioning properties such as sponge. This can prevent the wearer H wearing the face shield 10 from feeling uncomfortable. In the illustrated example, the band 25 covers only a part of the head of the wearer H, but the band 25 may cover the entire circumference of the head of the wearer H.

[0162] In the above-described embodiment, the shield part 30A covers the entire face F of the wearer H, but the present invention is not limited thereto. For example, as shown in FIG. 6, the shield part 30A (transparent laminated film 30) may cover only a part of the face F of the wearer H. In this case, the holding member 20 may have a chin pad 27 that abuts against the chin J of the wearer H, and a pair of hook parts 28 (only one of which is shown in FIG. 6) that are connected to the chin pad 27 and hooked on the ears E of the wearer H. The material of the chin pad 27 may be resin, cardboard, or the like. The hook parts 28 may be a string-like member, and the material of the hook parts 28 may be an elastic body such as rubber. In this modification, the shield part 30A covers the mouth M and nose N of the wearer H. This can prevent droplets of saliva and the like caused by sneezing or coughing from the wearer H from landing on the face of others, and can improve visibility of the mouth of the wearer H, enabling smooth communication between the wearer H and others. Note that the shield part 30A may cover only the vicinity of the mouth M of the wearer H, without covering the nose N.

[0163] In the above-described embodiment, the transparent laminate film 30 is used in the face shield 10 that protects the face F of the wearer H, but the present invention is not limited thereto. For example, as shown in FIG. 7, the transparent laminate film 30 may be attached to a pair of temple parts 21 as an accessory. In this case, as shown in FIG. 8, a pair of through holes 35 may be formed in the transparent laminate film 30, and the temple part 21 may be inserted into the through holes 35 to attach the transparent laminate film 30 to the temple part 21. In this modification, the width (distance in the left-right direction in FIG. 8) of the transparent laminate film 30 may be about 50 mm, and the length (distance in the up-down direction in FIG. 8) may be about 200 mm. EXAMPLES

[0164] Next, a specific example of the above embodiment will be described.

[0165] Example 1 First, the transparent laminated film 30 shown in FIG. 4A was produced. In this case, the surface antireflection layer 40 was produced first. When producing the surface antireflection layer 40, a triacetyl cellulose film (refractive index 1.49) having a thickness of 60 μm was prepared as the surface transparent substrate layer 42. Next, a hard coat layer forming coating liquid having the following formulation was applied on the triacetyl cellulose film, dried and irradiated with ultraviolet light to form a surface hard coat layer 44 having a thickness of 10 μm, a refractive index of 1·54, and a pencil hardness of 2H. Next, a high refractive index layer forming coating liquid having the following formulation was applied on the surface hard coat layer 44, dried and irradiated with ultraviolet light to form a surface high refractive index layer 46 having a thickness of 150 nm and a refractive index of 1.63. Next, a low refractive index layer forming coating liquid having the following formulation was applied on the surface high refractive index layer 46, dried and irradiated with ultraviolet light to form a surface low refractive index layer 45 having a thickness of 100 nm and a refractive index of 1.30, thereby obtaining a surface antireflection layer 40.

[0166] <Preparation of Coating Solution for Forming Hard Coat Layer> 1.6 parts by mass of photopolymerization initiator (BASF, Irgacure 127, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one) and 58.3 parts by mass of dilution solvent (methyl isobutyl ketone / cyclohexanone = 8 / 2) were added and stirred until there was no residue left. 20 parts by mass of photocurable resin (Arakawa Chemical, Beam Set 577) and 20 parts by mass of high refractive index resin (DIC, Polylight RX-4800) were added and stirred until there was no residue left. Finally, 0.1 parts by mass of leveling agent (Dainichi Seika Chemicals, Seika Beam 10-28 (MB)) were added and stirred to prepare a coating solution for forming a hard coat layer.

[0167] <Preparation of Coating Solution for Forming High Refractive Index Layer> 0.1 parts by mass of photopolymerization initiator (BASF, Irgacure 127) and 92.6 parts by mass of dilution solvent (methyl isobutyl ketone / cyclohexanone / methyl ethyl ketone = 4 / 2 / 4) were added and stirred until there was no residue left. 1.25 parts by mass of photocurable resin (Arakawa Chemical, Beam Set 577) were added and stirred until there was no residue left. Furthermore, 6 parts by mass of zirconium oxide (Sumitomo Osaka Cement, MZ-230X, solid content 32.5 mass%, average primary particle diameter 15 to 50 nm) and 0.05 parts by mass of leveling agent (Dainichi Seika Chemical Industry, Seika Beam 10-28 (MB)) were added and stirred to prepare a coating liquid for forming a high refractive index layer.

[0168] <Preparation of Coating Solution for Forming Low Refractive Index Layer> 0.2 parts by mass of photopolymerization initiator (BASF, Irgacure 127) and 91.1 parts by mass of dilution solvent (MIBK / AN=7 / 3) were added and stirred until there was no residue left. 1.0 parts by mass of photocurable resin (Nippon Kayaku, KAYARAD-PET-30), 7.6 parts by mass of hollow silica particles (solid content 20% by mass, average primary particle diameter 60 nm), and 0.1 parts by mass of leveling agent (Dainichi Seika Chemicals, Seikabeam 10-28 (MB)) were added and stirred to prepare a coating solution for forming a low refractive index layer.

[0169] Next, the back surface antireflection layer 50 was prepared. When preparing the back surface antireflection layer 50, first, a triacetyl cellulose film (refractive index 1.49) having a thickness of 60 μm was prepared as the back surface transparent substrate layer 52. Next, the coating liquid for forming a hard coat layer having the above-mentioned formulation was applied onto the triacetyl cellulose film, dried and irradiated with ultraviolet light to form a back surface hard coat layer 54 having a thickness of 10 μm, a refractive index of 1·54, and a pencil hardness of 2H. Next, the coating liquid for forming a high refractive index layer having the above-mentioned formulation was applied onto this back surface hard coat layer 54, dried and irradiated with ultraviolet light to form a back surface high refractive index layer 56 having a thickness of 150 nm and a refractive index of 1.63. Next, the coating liquid for forming a low refractive index layer having the above-mentioned formulation was applied onto this back surface high refractive index layer 56, dried and irradiated with ultraviolet light to form a back surface low refractive index layer 55 having a thickness of 100 nm and a refractive index of 1.30, thereby obtaining the back surface antireflection layer 50.

[0170] In parallel with producing the front-surface antireflection layer 40 and the back-surface antireflection layer 50, a 12 μm-thick polyethylene terephthalate film (refractive index 1.58-1.70) on which the printed layer 33 was formed was prepared as the printed layer 33 and the core layer 32.

[0171] Next, the front surface antireflection layer 40 and the core layer 32 on which the printed layer 33 was formed were bonded together via a first transparent adhesive layer 31a (Panac Corp., Panaclean series PD-S1, thickness 25 μm), and the core layer 32 on which the printed layer 33 was formed and the rear surface antireflection layer 50 were bonded together via a second transparent adhesive layer 31b (Panac Corp., Panaclean series PD-S1, thickness 25 μm) to produce a transparent laminate film 30. The layer structure of the obtained transparent laminate film 30 is as follows. Low bending / High bending / Hard coat / TAC / Adhesive / Printing / PET / Adhesive / TAC / Hard coat / High bending / Low bending In the above, "low refractive index" means a low refractive index layer on the front surface or a low refractive index layer on the back surface (same below). "High refractive index" means a high refractive index layer on the front surface or a high refractive index layer on the back surface (same below). "Hard coat" means a hard coat layer on the front surface or a hard coat layer on the back surface (same below). "TAC" means a triacetyl cellulose film (same below). "Adhesive" means a transparent adhesive layer (same below). "Printing" means a printed layer (same below). "PET" means a polyethylene terephthalate film (same below).

[0172] (1) Reflectance measurement test Next, a reflectance measurement test was carried out on the transparent laminate film 30.

[0173] At this time, first, a sample of 20 mm×20 mm size was cut out from the area of ​​the obtained transparent laminated film 30 where the printed layer 33 was not provided. Next, light was irradiated onto the surface of the sample so that the incident angle was 85° (the surface parallel to the film surface is 0°; the same applies below). Then, a spectrophotometer (V-7100, manufactured by JASCO Corporation) was used to calculate the luminous reflectance Y value from the reflection spectrum. At this time, the wavelength of light was set to 450 nm, 550 nm, and 650 nm, and the surface of the sample was irradiated with light for each wavelength. Then, a spectrophotometer (V-7100, manufactured by JASCO Corporation) was used to measure the reflection spectrum of the light, and the reflectance of the light at each wavelength was calculated.

[0174] (2) Design evaluation test In addition, a design evaluation test of the face shield 10 was conducted.

[0175] At this time, first, the face shield 10 shown in Fig. 1 was produced using the obtained transparent laminate film 30. Next, the printed layer 33 of the face shield 10 was observed, and the design of the face shield was evaluated.

[0176] (3) Transmittance measurement test In addition, a transmittance measurement test was carried out on the transparent laminate film 30.

[0177] At this time, first, a sample of 20 mm x 20 mm size was cut out from the obtained transparent laminate film 30. Next, light was irradiated onto the surface of the sample so that the incident angle was 85°. At this time, the wavelengths of the light were set to 450 nm, 550 nm, and 650 nm, and the light was irradiated onto the surface of the sample for each wavelength. Then, the light transmission spectrum was measured using a spectrophotometer (V-7100, manufactured by JASCO Corporation), and the light transmittance at each wavelength was calculated.

[0178] (4) Wearability evaluation test In addition, a test to evaluate the fit of the face shield 10 was conducted.

[0179] First, the obtained transparent laminate film 30 was used to produce the face shield 10 shown in FIG. 1. Next, five experimenters were randomly selected from men and women aged 22 or older. The five selected experimenters performed clerical work while wearing the face shield 10. After that, the five experimenters who performed clerical work for one hour were interviewed about whether or not the impression of wearing the face shield 10 remained.

[0180] (5) Visibility evaluation test In addition, a visibility evaluation test of the face shield 10 was conducted.

[0181] At this time, first, the face shield 10 shown in FIG. 1 was produced using the obtained transparent laminate film 30. Next, five experimenters were randomly selected from men and women aged 22 or older. Then, the visibility of the facial expressions of the five experimenters wearing the face shield 10 was confirmed. At this time, in a general indoor environment illuminated by fluorescent lights, the experimenter's facial expressions were observed from a distance of about 1 m to 2 m from the experimenter. In addition, the observer observed the experimenter's facial expressions while moving about 20° to the left and right around the surface 301 of the face shield 10 from a state facing the experimenter.

[0182] (6) Drop strength evaluation test In addition, a drop strength evaluation test of the face shield 10 was conducted.

[0183] At this time, first, the face shield 10 shown in FIG. 1 was produced using the obtained transparent laminate film 30. Next, a drop test was performed on the face shield 10. At this time, first, one of the temple parts 21 of the holding member 20 of the face shield 10 was pinched, and the face shield 10 was lifted so that the temple part 21 was at a height of 170 mm from the ground. Then, the face shield 10 was allowed to freely fall to the ground. In this way, the drop test was performed on the face shield 10. Then, such a drop test was repeated 10 times, and it was confirmed whether or not there was a change in the appearance of the face shield 10.

[0184] (7) Scratch resistance evaluation test In addition, a scratch resistance evaluation test of the transparent laminate film 30 was carried out.

[0185] At this time, first, the obtained transparent laminate film 30 was pinched with fingers to leave a fingerprint on the transparent laminate film 30. Next, the attached fingerprint was wiped off with Kimwipe S-200 (product name). At this time, the Kimwipe S-200 was not impregnated with any chemicals such as alcohol, and the fingerprint was wiped off with Kimwipe S-200 in a dry state. Then, this test was repeated three times, and it was confirmed whether or not the transparent laminate film 30 had been scratched after the fingerprint was wiped off. In addition, in the three tests, the fingerprint was attached to the same position by pinching approximately the same part of the transparent laminate film 30 with fingers.

[0186] In addition, when the transparent laminate film 30 was rubbed with a pencil, it was confirmed whether or not the transparent laminate film 30 was scratched. At this time, the core of a pencil with hardness H was pushed out by about 5 mm, and then the lower surface of the core was flattened by rubbing with sandpaper. Next, the pencil was rubbed against the transparent laminate film 30 in a state in which the pencil was tilted with respect to the surface 301 so that the angle between the lower surface of the core and the surface 301 of the transparent laminate film 30 was about 45°. In addition, when the pencil was rubbed against the transparent laminate film 30, the pencil was rubbed against the transparent laminate film 30 so that the movement distance of the pencil was about 3 cm, and the amount of indentation of the surface 301 of the face shield 10 was about 5 mm or more and about 10 mm. Then, such a test was repeated 100 times, and it was confirmed whether or not the transparent laminate film 30 after the pencil was rubbed was scratched.

[0187] (8) Alcohol resistance evaluation test In addition, an alcohol resistance evaluation test of the transparent laminate film 30 was carried out.

[0188] At this time, first, the surface 301 of the transparent laminate film 30 was wiped with Kimwipe S-200 (product name) sufficiently saturated with ethanol. At this time, the surface 301 of the transparent laminate film 30 was wiped so that the Kimwipe S-200 came into contact with the edge face located between the surface 301 and the back surface 302 of the transparent laminate film 30. Then, such a test was repeated 100 times, and it was confirmed whether or not there was a change in the appearance of the transparent laminate film 30.

[0189] (9) Droplet prevention functionality evaluation test In addition, a splash prevention functionality evaluation test of the transparent laminate film 30 was carried out.

[0190] In this case, first, an alcohol spray bottle (capacity 30 ml) was filled with colored ink (Shachihata refill ink (XLR-20N red 20 ml for Capless 9·X stamper)). Next, an A3 paper was attached to the wall. Next, the experimenter wearing a face shield 10 faced the wall at a distance of 50 cm. Next, a spray was placed between the experimenter's mouth and the face shield 10 so that the nozzle of the spray faced the wall. After that, the colored ink was sprayed from the spray. After spraying, it was confirmed whether or not the colored ink had adhered to the paper attached to the wall.

[0191] (10) UV transmittance measurement test In addition, a UV transmittance measurement test of the transparent laminate film 30 was carried out.

[0192] At this time, the UV transmittance measurement test was carried out in the same manner as in the above-mentioned transmittance measurement test, except that the wavelength of the irradiated light was 380 nm.

[0193] (11) Antifouling evaluation test In addition, a stain-resistant evaluation test of the transparent laminate film 30 was carried out.

[0194] At this time, first, a line is drawn on the surface 301 of the obtained transparent laminate film 30 with an oil-based marker, Immediately afterwards, the fingerprints were wiped off with Kimwipe S-200 (trade name). At this time, the Kimwipe S-200 was not impregnated with any chemicals such as alcohol, and the fingerprints were wiped off with the dry Kimwipe S-200.

[0195] Example 2 A commercially available low-reflection film (FG-10MR1, manufactured by Sharp Corporation) was used, and the low-reflection film and the core layer 32 on which the printed layer 33 was formed were bonded to each other via a first transparent adhesive layer 31a (Panac Corporation, Panaclean series PD-S1, thickness 25 μm). A commercially available low-reflection film (FG-10MR1, manufactured by Sharp Corporation) was bonded to the surface of the core layer 32 on which the low-reflection film was not bonded via a second transparent adhesive layer 31b (Panac Corporation, Panaclean series PD-S1, thickness 25 μm). The same procedures as in Example 1 were performed except that a reflectance measurement test, a design evaluation test, a transmittance measurement test, a wearability evaluation test, a visibility evaluation test, a drop strength evaluation test, a scratch resistance evaluation test, an alcohol resistance evaluation test, a splash prevention functionality evaluation test, a UV transmittance measurement test, and an antifouling evaluation test were performed.

[0196] Here, when the cross section of the low reflection film of Example 2 was analyzed by SEM, it was found to have a three-layer structure consisting of a 187 μm thick resin layer and two resin layers, each 2 to 3 μm thick and having irregularities on the surface side, laminated above and below the resin layer.

[0197] Comparative Example 1 A reflectance measurement test, a design evaluation test, a transmittance measurement test, a wearability evaluation test, a visibility evaluation test, a drop strength evaluation test, a scratch resistance evaluation test, an alcohol resistance evaluation test, a splash prevention functionality evaluation test, a UV transmittance measurement test, and an antifouling evaluation test were performed in the same manner as in Example 1, except that a commercially available transparent film (YF-800L (product name) manufactured by Yamamoto Kogaku Co., Ltd.) and a core layer on which a printed layer was formed were adhered to each other via a transparent adhesive layer (Panac Corporation, Panaclean Series PD-S1, thickness 25 μm).

[0198] Here, when the cross section of the transparent laminate film according to Comparative Example 1 was analyzed by SEM, it was found to have a three-layer structure in which a resin layer having a thickness of 150 μm was laminated above and below a resin layer having a thickness of 3 μm.

[0199] Comparative Example 2 A reflectance measurement test, design evaluation test, transmittance measurement test, wearability evaluation test, visibility evaluation test, drop strength evaluation test, scratch resistance evaluation test, alcohol resistance evaluation test, splash prevention functionality evaluation test, UV transmittance measurement test, and antifouling evaluation test were performed in the same manner as in Example 1, except that a commercially available low-reflection film (FG-10MR1, manufactured by Sharp Corporation) and a core layer on which a printed layer was formed were adhered to each other via a transparent adhesive layer (Panac Clean Series PD-S1, manufactured by Panac Corporation, thickness 25 μm).

[0200] The above results are shown in Tables 1 to 4. Table 1 shows the results of the reflectance measurement test and the design evaluation test. Table 2 shows the results of the transmittance measurement test. Table 3 shows the results of the wearability evaluation test, the visibility evaluation test, and the drop strength evaluation test. Table 4 shows the results of the scratch resistance evaluation test, the alcohol resistance evaluation test, and the splash prevention functionality evaluation test. Table 5 shows the results of the UV transmittance measurement test and the antifouling evaluation test.

[0201] [Table 1]

[0202] In the design column of Table 1, "○" means that the area of ​​the transparent laminate film 30 of the face shield 10 where the printed layer 33 was not provided was not noticeable, and the printed layer 33 was noticeable. "△" means that depending on the angle at which the face shield is viewed and the surrounding lighting environment, the area where the printed layer was not provided was noticeable, and the printed layer was not noticeable. "×" means that the area of ​​the transparent laminate film of the face shield where the printed layer was not provided was noticeable, and the printed layer was not noticeable.

[0203] [Table 2]

[0204] [Table 3]

[0205] In the column for the wearability evaluation test in Table 3 above, "○" means that the wearer's reflection in the transparent laminate film 30 is not visible, and there is no impression that the face shield is being worn. "△" means that, depending on factors such as the surrounding lighting environment or the direction of the wearer's face, the wearer's reflection in the transparent laminate film is visible, although not always, and the wearer sometimes has the impression that the face shield is being worn, and feels a slight sense of fatigue. "×" means that the wearer's reflection in the transparent laminate film is visible, which interferes with work, and the wearer has the impression that the face shield is being worn, and feels fatigued.

[0206] In the column for the visibility evaluation test in Table 3, "○" means that the wearer's facial expression could be clearly confirmed. "△" means that depending on the angle at which the wearer is viewed, the observer is reflected in the transparent laminate film, making it difficult to confirm the wearer's facial expression. "×" means that regardless of the angle at which the wearer is viewed, the observer is reflected in the transparent laminate film, making it difficult to confirm the wearer's facial expression.

[0207] Furthermore, in the column for the drop strength evaluation test in Table 3 above, "○" means that no deformation or damage was found in the transparent laminate film of the face shield.

[0208] [Table 4]

[0209] In the "fingerprint" column of the scratch resistance evaluation test in Table 4, "○" means that the fingerprint could be wiped off without causing scratches on the transparent laminate film, and "×" means that scratches were caused on the transparent laminate film when the fingerprint was wiped off, and the transparent laminate film had a cloudy white appearance due to fine scratches.

[0210] In the "pencil" column of the scratch resistance evaluation test in Table 4, "○" means that no scratches were generated on the transparent laminate film. "△" means that light scratches were generated on the transparent laminate film. Furthermore, "×" means that dark scratches were generated on the transparent laminate film, and the appearance of the transparent laminate film was deteriorated.

[0211] In the column for the alcohol resistance evaluation test in Table 4, "○" means that no change occurred in the appearance of the transparent laminate film, and "×" means that the transparent laminate film was discolored and its appearance was deteriorated.

[0212] Furthermore, in the column for the splash prevention functionality evaluation test in Table 4 above, "◯" means that no colored ink was found to adhere to the paper, and "×" means that colored ink was found to adhere to the paper.

[0213] [Table 5]

[0214] In the column for the stain resistance evaluation test in Table 5 above, "○" means that the lines disappeared after wiping, and "×" means that the oil-based ink could not be wiped off and the lines remained clearly.

[0215] As a result, as shown in Table 1, the transparent laminate film according to Comparative Example 1 had a luminous reflectance Y value of 8.6%, and the transparent laminate film according to Comparative Example 2 had a luminous reflectance Y value of 3.7%. In contrast, the transparent laminate film 30 according to Example 1 had a luminous reflectance Y value of 0.6%, and the transparent laminate film 30 according to Example 2 had a luminous reflectance Y value of 0.7%. In this way, the transparent laminate films 30 according to Examples 1 and 2 were able to reduce the luminous reflectance Y value. For this reason, it was found that the area of ​​the transparent laminate film 30 where the printed layer 33 was not provided could be made less noticeable.

[0216] Also, as shown in Table 1, the transparent laminate film according to Comparative Example 1 had a reflectance of 8.6% for light having a wavelength of 550 nm, and the transparent laminate film according to Comparative Example 2 had a reflectance of 3.6% for light having a wavelength of 550 nm. In contrast, the transparent laminate film 30 according to Example 1 had a reflectance of 0.6% for light having a wavelength of 550 nm, and the transparent laminate film 30 according to Example 2 had a reflectance of 0.7% for light having a wavelength of 550 nm. Thus, the transparent laminate films 30 according to Examples 1 and 2 were able to reduce the reflectance of light having a wavelength of 550 nm. Furthermore, the transparent laminate films 30 according to Examples 1 and 2 were able to reduce the reflectance of light having a wavelength of 450 nm, 0.8% and 0.7%, respectively, and the reflectance of light having a wavelength of 650 nm, 1.0% and 0.6%, respectively. Thus, the transparent laminate films 30 according to Examples 1 and 2 were able to reduce the reflectance of light in each of the cases where the wavelengths of light were 450 nm, 550 nm, and 650 nm. For this reason, it was found that the transparent laminate film 30 according to the present embodiment can reduce the light reflectance.

[0217] Also, as shown in Table 1, in the face shield according to Comparative Example 1, the area where the printed layer was not provided was conspicuous, and the printed layer was not conspicuous. In addition, in the face shield according to Comparative Example 1, depending on the angle at which the face shield is viewed and the surrounding lighting environment, the area where the printed layer was not provided was conspicuous, and the printed layer was not easily noticeable. In contrast, in the face shields according to Examples 1 and 2, the area where the printed layer 33 was not provided was not conspicuous, and the printed layer 33 could be made to stand out. In this way, it was found that the face shields 10 according to Examples 1 and 2 can display designs different from conventional designs, and can improve the design of the face shield.

[0218] Furthermore, as shown in Table 2, in the transparent laminate films of Comparative Examples 1 and 2, when the light wavelength was 450 nm, the light transmittance was 87.7% and 93.7%, when the light wavelength was 550 nm, the light transmittance was 89.2% and 95.4%, and when the light wavelength was 650 nm, the light transmittance was 90.8% and 96.7%. In contrast, in the transparent laminate film 30 according to Example 1 and Example 2, the light transmittance was 94.7% and 96.4% when the wavelength of light was 450 nm, the light transmittance was 97.3% and 98.3% when the wavelength of light was 550 nm, and the light transmittance was 97.8% and 99.6% when the wavelength of light was 650 nm. Therefore, it was found that the transparent laminate film 30 according to the present embodiment can improve the light transmittance.

[0219] Also, as shown in Table 3, in the wearability evaluation test, the transparent laminate film according to Comparative Example 1 showed a reflection of the wearer on the transparent laminate film, which hindered work and gave the impression that a face shield was being worn, resulting in a feeling of fatigue. In addition, the transparent laminate film according to Comparative Example 2 showed that the reflection of the wearer on the transparent laminate film, etc., was visible, although not always, due to factors such as the surrounding lighting environment or the direction of the wearer's face, and sometimes gave the impression that a face shield was being worn, resulting in a weak but tired feeling. On the other hand, in Examples 1 and 2, the reflection of the wearer on the transparent laminate film 30 was not visible, and the hearing results showed that there was no impression that a face shield was being worn. Thus, the transparent laminate film 30 according to Examples 1 and 2 was able to reduce the reflection of the wearer on the transparent laminate film 30, and was able to suppress the wearer wearing the face shield 10 from feeling tired.

[0220] Furthermore, as shown in Table 3, in the visibility evaluation test, in the transparent laminate film of Comparative Example 1, the observer was reflected in the transparent laminate film, preventing confirmation of the wearer's facial expression regardless of the angle at which the wearer was viewed. In addition, in the transparent laminate film of Comparative Example 2, depending on the angle at which the wearer was viewed, the observer was reflected in the transparent laminate film, preventing confirmation of the wearer's facial expression. On the other hand, in the transparent laminate film 30 of Examples 1 and 2, the wearer's facial expression could be clearly confirmed.

[0221] Furthermore, as shown in Table 3, in the drop strength evaluation test, no deformation or damage was observed in the transparent laminate film 30 of the face shield 10 in the face shields 10 according to Examples 1 and 2. Thus, it was found that the transparent laminate film etc. according to the present embodiment can suppress a decrease in drop strength compared to conventional transparent laminate films.

[0222] Furthermore, as shown in Table 4, in the scratch resistance evaluation test, in the transparent laminate film 30 according to Example 1, fingerprints could be wiped off without causing scratches on the transparent laminate film 30. Furthermore, in the transparent laminate film 30 according to Example 1, when a pencil was rubbed against the transparent laminate film 30, no scratches were caused on the transparent laminate film 30. Thus, in the transparent laminate film 30 according to Example 1, it was possible to suppress a decrease in the scratch resistance of the transparent laminate film 30.

[0223] Furthermore, as shown in Table 4, in the alcohol resistance evaluation test, the transparent laminate film 30 according to Example 1 did not undergo any change in appearance. Thus, the transparent laminate film 30 according to Example 1 was able to suppress a decrease in the alcohol scratch resistance of the transparent laminate film 30.

[0224] Furthermore, as shown in Table 4, in the splash prevention functionality evaluation test, the face shields 10 of Examples 1 and 2 were also able to prevent splashes of a certain size in front of the wearer H of the face shield 10.

[0225] Furthermore, as shown in Table 5, the transparent laminate film 30 according to Example 1 had a UV transmittance of 0.1%. In this manner, the transparent laminate film 30 according to Example 1 was able to reduce the UV transmittance. This means that the wearer H can be made less susceptible to sunburn even when the wearer H is outdoors in an environment where he or she is exposed to direct sunlight.

[0226] Furthermore, as shown in Table 5, in the stain resistance evaluation test, the oil-based ink could be wiped off with the transparent laminate film 30 of Example 1, and the lines disappeared after wiping. Thus, the oil-based ink that is difficult to remove could be easily removed with the transparent laminate film 30 of Example 1. As a result, even if dirt adheres to the face shield 10, the dirt can be easily wiped off from the face shield 10, and the face shield 10 can be easily restored to a clean state.

[0227] It is also possible to combine the multiple components disclosed in the above embodiments as necessary, or to delete some of the components disclosed in the above embodiments. [Explanation of symbols]

[0228] 10. Face Shield 20 Retaining member 21 Temple Section 22 Front section 23 Pad section 25 Bands 27 Chin pad 28 Hook 30 Transparent laminated film 31a 1st transparent adhesive layer 31b Second transparent adhesive layer 32 Core layer 33 Printing layer 40 Surface antireflection layer 41 Surface anti-reflection functional layer 42 Surface transparent base material layer 43 Surface Refraction Layer 44 Surface hard coat layer 45 Surface low refractive index layer 46 High refractive index surface layer 47 First surface high refractive index layer 48 Second surface high refractive index layer 50 Back anti-reflection layer 51 Backside anti-reflection layer 52 Back transparent base layer 53 Backside refraction layer 54 Backside hard coat layer 55 Backside low refractive index layer 56 Backside high refractive index layer 57 First back surface high refractive index layer 58 Second back surface high refractive index layer 60 Transparent laminated film with protective film 61 Surface protection film 62 Back protection film 301 Surface 302 Back side C. Cheek E ear F. Face H Wearer J. Jaw M mouth N nose

Claims

1. A transparent laminate film having a front surface and a back surface, A core layer; a printing layer covering a part of the front surface or a part of the back surface of the core layer; a surface antireflection layer provided on one side of the core layer and constituting the surface; a back surface antireflection layer provided on the other side of the core layer and constituting the back surface; In the region where the printing layer is not provided, the luminous reflectance Y value is 0.0% or more and 2.0% or less, the printing layer is provided between the core layer and the front-surface antireflection layer or between the core layer and the rear-surface antireflection layer, the front-surface antireflection layer includes a front-surface antireflection functional layer and a front-surface transparent substrate layer disposed in this order from the front surface to the back surface, The back surface antireflection layer is a transparent laminate film having a back surface antireflection functional layer and a back surface transparent substrate layer arranged in this order from the back surface to the front surface.

2. 2. The transparent laminate film according to claim 1, wherein in an area where the printed layer is not provided, the reflectance of light having a wavelength of 550 nm is 2% or less, and the total light transmittance is 90% or more.

3. 3. The transparent laminate film according to claim 1, wherein the transmittance of ultraviolet light having a wavelength of 380 nm or less in an area where the printed layer is not provided is 1% or less.

4. The transparent laminate film according to claim 1 , wherein the core layer comprises polyethylene terephthalate.

5. a first transparent adhesive layer that adheres the front-surface antireflection layer and the core layer; The transparent laminate film according to claim 1 , further comprising a second transparent adhesive layer that bonds the core layer and the back surface antireflection layer.

6. The transparent laminate film according to claim 5 , wherein the first transparent adhesive layer and the second transparent adhesive layer each contain an acrylic adhesive.

7. A surface antireflection layer constituting the surface; A back surface antireflection layer constituting a back surface; a printed layer provided between the front-surface antireflection layer and the back-surface antireflection layer and covering a part of the front-surface antireflection layer, In the region where the printing layer is not provided, the luminous reflectance Y value is 0.0% or more and 2.0% or less, the front-surface antireflection layer includes a front-surface antireflection functional layer and a front-surface transparent substrate layer disposed in this order from the front surface to the back surface, The back surface antireflection layer is a transparent laminate film having a back surface antireflection functional layer and a back surface transparent substrate layer arranged in this order from the back surface to the front surface.

8. 8. The transparent laminate film according to claim 7, wherein in an area where the printed layer is not provided, the reflectance of light having a wavelength of 550 nm is 2% or less, and the total light transmittance is 90% or more.

9. 9. The transparent laminate film according to claim 7, wherein the transmittance of ultraviolet light having a wavelength of 380 nm or less in an area where the printed layer is not provided is 1% or less.

10. the front-surface antireflection functional layer is a coating layer coated on the front-surface transparent substrate layer, The transparent laminate film according to claim 1 , wherein the rear surface antireflection functional layer is a coating layer coated on the rear surface transparent substrate layer.

11. The transparent laminate film according to claim 1 , wherein the front-surface antireflection functional layer and the back-surface antireflection functional layer are each made of a cured product of an ionizing radiation curable resin composition.

12. The transparent laminate film according to claim 11 , wherein the ionizing radiation curable resin composition contains a (meth)acrylate compound.

13. The front-surface antireflection functional layer includes a front-surface refraction layer and a front-surface hard coat layer arranged in this order from the front surface to the back surface, The transparent laminate film according to claim 1 , wherein the back surface antireflection functional layer includes a back surface refraction layer and a back surface hard coat layer arranged in this order from the back surface to the front surface.

14. the surface hard coat layer is a coating layer coated on the surface transparent substrate layer, the surface refractive layer is a coating layer coated on the surface hard coat layer, the back surface hard coat layer is a coating layer coated on the back surface transparent substrate layer, The transparent laminate film according to claim 13 , wherein the rear surface refraction layer is a coating layer coated on the rear surface hard coat layer.

15. the surface refractive layer includes a surface low refractive index layer and a surface high refractive index layer arranged in this order from the surface to the back surface, The transparent laminate film according to claim 13 or 14, wherein the back surface refractive layer includes a back surface low refractive index layer and a back surface high refractive index layer arranged in this order from the back surface to the front surface.

16. the surface high refractive index layer includes a first surface high refractive index layer and a second surface high refractive index layer arranged in this order from the surface to the back surface, The transparent laminate film according to claim 15 , wherein the back surface high refractive index layer includes a first back surface high refractive index layer and a second back surface high refractive index layer arranged in this order from the back surface to the front surface.

17. the refractive index of the first surface high refractive index layer is higher than the refractive index of the second surface high refractive index layer; The transparent laminate film according to claim 16 , wherein the refractive index of the first back surface high refractive index layer is higher than the refractive index of the second back surface high refractive index layer.

18. The transparent laminate film according to claim 17 , wherein the front transparent substrate layer and the back transparent substrate layer contain triacetyl cellulose or polyethylene terephthalate.

19. The transparent laminate film according to claim 17 , wherein one of the front transparent substrate layer and the back transparent substrate layer contains triacetyl cellulose, and the other contains polyester.

20. The transparent laminate film according to claim 17 , wherein the front transparent substrate layer and the back transparent substrate layer each contain polyester.

21. The transparent laminate film according to any one of claims 1 to 20, having a thickness of 40 µm or more and 500 µm or less.

22. The transparent laminate film according to any one of claims 1 to 21, which has a restoring function.

23. The transparent laminate film according to any one of claims 1 to 22, which is used for a face shield for protecting the face of a wearer.

24. A transparent laminate film according to any one of claims 1 to 23, a surface protection film for protecting the surface of the transparent laminate film; A transparent laminate film with a protective film, comprising a back surface protective film that protects the back surface of the transparent laminate film.

25. In a face shield that protects the wearer's face, A holding member attached to the wearer; A face shield comprising: a transparent laminate film according to any one of claims 1 to 24 attached to the retaining member and covering at least a portion of the face of the wearer.

26. The face shield according to claim 25, wherein the printed layer is positioned to overlap the cheek of the wearer when viewed from the front.

27. 27. The face shield according to claim 25, wherein when the wearer wears the face shield, a distance between the wearer's nose and the holding member is 100 mm or less.

28. 28. The face shield according to any one of claims 25 to 27, wherein the retaining member has a pair of temple portions that abut against the wearer's ears, a front portion that connects the pair of temple portions to each other, and a pair of pad portions that extend downward from the front portion and abut against the wearer's nose.

29. 28. A face shield as claimed in any one of claims 25 to 27, wherein the retaining member comprises a band that circumferentially wraps around the wearer's head.

30. 28. The face shield according to claim 25, wherein the retaining member has a chin pad that abuts against the chin of the wearer and a pair of hook portions that are connected to the chin pad and hooked onto the wearer's ears, and the transparent laminate film covers at least the wearer's mouth.

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