JP2017061161A - Release sheet and resin leather - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet capable of simply producing a resin leather that exhibits high glossy feeling in which shininess is suppressed, and exhibits designability due to change of glossy feeling according to an observation region, and to provide a resin leather produced using the release sheet.SOLUTION: There is provided a release sheet 10 that has a base material 1 and a release layer 2 having a lens portion 3 where a plurality of unit lenses 3a having a curved surface are arranged provided thereon, on the base material 1, wherein a radius of curvature of the unit lens 3a is 15-150 μm, and a diffusion angle when light is incident on the lens portion 3 from a vertical direction is 5-90°.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a release sheet and a resin leather. In particular, a release sheet capable of easily producing a resin leather that exhibits a high gloss feeling with suppressed shine and expresses a design property due to a change in glossiness according to the observation area, and the above design property Resin leather.

Resin leather such as synthetic leather can be manufactured by peeling the release sheet after coating and curing the resin composition as a raw material on the release sheet having peelability on the surface, The skin layer formed by the resin composition has a texture and color similar to natural leather.
In recent years, optical design has been required for resin leather, and in order to produce such resin leather, various devices have been studied for release sheets. For example, in Patent Documents 1 and 2, a release sheet having a holographic fine uneven shape on the surface has been proposed, and synthetic leather produced using such a release sheet was applied to the skin layer. The hologram-like fine uneven shape can give a rainbow-colored gloss depending on the observation angle.

  In the present specification, the resin leather is a leather simulating natural leather formed of a resin, and is a generic name for synthetic leather and artificial leather.

JP-A-4-361671 JP 2010-2537779 A

  The techniques disclosed in Patent Documents 1 and 2 enable improvement in design properties due to a change in glossy color with respect to resin leather. On the other hand, the glossiness depends on the observation region regardless of the change in glossy color. Resin leather that develops design properties due to changes in height (change in glossiness), specifically, within a certain observation angle range (observation region), it exhibits high glossiness while exhibiting the original color of the resin leather. However, there is a demand for a resin leather that exhibits a design property that such glossiness is not visually recognized in other observation regions. In addition, when trying to enhance the glossiness, there is also a shine that causes the surface to shine brightly, resulting in a glossiness different from the original gloss of the resin leather. For this reason, there is also a demand for high glossiness with reduced shine as a design property of resin leather, and a release sheet capable of producing resin leather having these design properties is required.

  The present invention has been made in view of the above circumstances, and it is possible to easily produce a resin leather that exhibits a high gloss feeling with suppressed shine and expresses a design property due to a change in the gloss feeling according to the observation region. The main object is to provide a possible release sheet and a resin leather that exhibits a high glossiness with suppressed shine and can exhibit design properties by changing the glossiness depending on the observation region.

  As a result of the present inventors diligently studying to realize the resin leather having the above-described design properties, the resin leather obtained by using a release sheet having a plurality of curved unit lenses on its surface The distribution of the scattering intensity of the specular reflection component and the diffuse reflection component of the reflected light generated on the resin leather surface (hereinafter referred to as the scattering distribution of the reflected light) It was found that it is possible to adjust. And by adjusting the scattering distribution of the reflected light, it was found that the resin leather can change the glossiness according to the observation area and can exhibit a high glossiness with reduced shine. . The present invention has been made based on such findings.

  That is, one embodiment of the present invention provides a release sheet having a base material and a release layer having a lens portion on the surface of which a plurality of unit lenses having curved surfaces are arranged on the base material. .

  One embodiment of the present invention provides a release sheet having a lens portion having a plurality of unit lenses having a curved surface on the surface, and a radius of curvature of the unit lens being 15 μm or more and 150 μm or less.

  One embodiment of the present invention provides a resin leather having a support layer and a resin skin layer having a lens-shaped portion on the surface of which a plurality of unit lens shapes having curved surfaces are arranged on the support layer.

  One embodiment of the present invention provides a resin leather having a lens shape portion having a plurality of unit lens shapes having a curved surface on the surface, and a radius of curvature of the unit lens shape being 15 μm or more and 150 μm or less.

The release sheet according to an embodiment of the present invention is capable of easily producing a resin leather that exhibits a high glossiness with reduced shine and expresses a design property due to a change in glossiness according to the observation region. There is an effect.
In addition, the resin leather according to an embodiment of the present invention exhibits a high gloss feeling with shine being suppressed by a plurality of unit lens shapes provided on the surface, and exhibits a design property due to a change in the gloss feeling depending on the observation region. There is an effect that can be.

It is the schematic perspective view and sectional drawing which show an example of the release sheet which concerns on one Embodiment of this invention. It is the schematic perspective view and sectional drawing which show the other example of the release sheet which concerns on one Embodiment of this invention. It is explanatory drawing explaining the scattered light intensity distribution by the shape of a reflective surface. It is explanatory drawing explaining the definition of a diffusion angle. It is explanatory drawing explaining the cross-sectional shape of a unit lens. It is the schematic perspective view and sectional drawing which show the other example of the release sheet which concerns on one Embodiment of this invention. It is explanatory drawing explaining the difference between the scattering angle when the scattered light intensity is 20% and the scattered angle when the scattered light intensity is 80% in the scattered light intensity distribution curve. It is a schematic sectional drawing which shows the other example of the release sheet which concerns on one Embodiment of this invention. It is the schematic perspective view and sectional drawing which show an example of the resin leather which concerns on one Embodiment of this invention. It is the schematic perspective view and sectional drawing which show the other example of the resin leather which concerns on one Embodiment of this invention. It is a schematic diagram which shows the usage example of the resin leather which concerns on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different modes and should not be construed as being limited to the description of the embodiments exemplified below. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with the actual mode for clarity of explanation, but are merely examples and limit the interpretation of the present invention. Not what you want. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate. Further, for convenience of explanation, the description may be made using the terms “upper” or “lower”, but the vertical direction may be reversed.

  In addition, when giving a specific value below, the value is understood including the error etc. resulting from manufacture to such an extent that the effect which this embodiment show | plays is not impaired too much. In addition, the phrase indicating the degree of “vertical” is understood to include errors due to manufacturing and the like to the extent that the effect of the present embodiment is not excessively impaired in the same manner as described above.

A. Release Sheet A release sheet according to an embodiment of the present invention (hereinafter, sometimes referred to as a release sheet according to the present embodiment) includes a base material and a plurality of unit lenses having a curved surface on the base material. And a release layer provided on the surface with the lens part arranged.

The release sheet according to the present embodiment will be described with reference to the drawings. FIG. 1A and FIG. 2A are schematic perspective views showing an example and another example of a release sheet according to this embodiment, and FIG. 1B and FIG. ) And a sectional view taken along line XX in FIG. The release sheet 10 includes a base material 1 and a release layer 2 that is provided on the base material 1 and includes a lens unit 3 on the surface of which a plurality of curved unit lenses 3a are provided.
FIG. 1 shows an example in which the unit lens 3 a has a convex curved surface shape protruding from the surface of the release layer 2. FIG. 2 shows an example in which the unit lens 3 a has a concave curved surface shape that is recessed from the surface of the release layer 2. 1 and 2, the lens unit 3 has a microlens array shape.

  According to the release sheet according to the present embodiment, the surface of the release layer has a lens portion in which a plurality of unit lenses having a curved surface are arranged, so that a lens shape portion in which a plurality of desired unit lens shapes are arranged. Can be easily produced. The resin leather obtained from the release sheet according to the present embodiment is provided with the lens-shaped portion, so that the scattering distribution of reflected light generated on the surface of the resin leather is adjusted. The design property by the change of a glossiness according to an observation area | region can be expressed.

Here, the reason why the obtained resin leather can exhibit the above-described design properties when the release sheet according to the present embodiment has the above-described configuration will be described below.
When light strikes the resin leather, the light component that reflects at the same angle as the incident angle (specular reflection component) and the light component that reflects in a random direction and diffuses widely (diffuse reflection component) on the surface of the resin leather Will occur.
In order to increase the glossiness of the resin leather, generally, a method is adopted in which the surface is smooth and the ratio of the specular reflection component is increased. However, in this method, the specular reflection component of the reflected light generated on the surface of the resin leather directly enters the eyes of the observer. Glossiness different from gloss is developed. At this time, the direction in which the specular reflection occurs is limited to a narrow angle region, and thus the observation region where the glossiness of the resin leather can be visually recognized is limited.
On the other hand, if the surface of the resin leather is subjected to surface treatment by embossing, blasting, plating, etc., and random fine irregularities are applied, the proportion of diffuse reflection components in the reflected light generated on the surface of the resin leather increases. , Can reduce the occurrence of shine. At this time, since diffuse reflection occurs in a wide range, the observation area where the glossiness of the resin leather can be visually recognized is wider than that on a smooth surface.
However, when the ratio of the diffuse reflection component increases, the glossiness decreases, and the resin leather is visually recognized as white due to the mixture of the diffuse reflection component and the specular reflection component.

The difference in glossiness and the wideness and narrowness of the region where high glossiness can be visually recognized are due to the anisotropy of the scattered light intensity of light incident on the resin leather from the desired angle and the size of the diffusion angle. Inferred.
Here, the anisotropy of the scattered light intensity can be explained by the degree of the gradient of the scattered light intensity distribution with respect to the scattering angle. The diffusion angle can be defined from the scattered light intensity distribution with respect to the scattering angle. As shown in FIG. 3, the diffusion angle is such that the scattered light intensity L is the maximum scattered light intensity in the scattered light intensity distribution curves Px and Py where the scattered angle (θ) is the X axis and the scattered light intensity (L) is the Y axis. The half-value width FWHM which is a difference (θ ₂ −θ ₁ ) between two scattering angles θ _{1 (Px)} and θ _{1 (Py)} and θ _{2 (Px)} and θ _{2 (Py)} , which is a half of L _max (Px) and FWHM (Py). For example, if the scattering angle (θ), which is a half of the maximum scattered light intensity L _max , is in the range of θ ₁ = −10 ° to θ ₂ = + 10 °, the diffusion angle is 20 °. Details of the scattered light intensity measurement method will be described later.

Since the reflected light generated on the smooth surface has many specular reflection components, the scattered light intensity distribution curve P has a steep gradient as shown in FIG. Is small. At this time, since the range of the scattering angle θ that is a half of the maximum scattered light intensity L _max is small, the calculated diffusion angle FWHM is also small. On the other hand, since the reflected light generated on the random fine uneven surface has many diffuse reflection components, the gradient of the scattered light intensity distribution curve P is gentle as shown in FIG. High anisotropy. At this time, since the range of the scattering angle θ that is a half of the maximum scattered light intensity L _max is large, the calculated diffusion angle FWHM becomes large.
That is, the steep slope of the scattered light intensity distribution curve decreases the anisotropy of the scattered light intensity and increases the gloss of the resin leather. On the other hand, the wider the range of the diffusion angle, the wider the observation area where the glossiness of the resin leather can be visually recognized.

The resin leather obtained by the release sheet according to the present embodiment has a plurality of curved surfaces by transferring a unit lens having a plurality of curved surfaces provided on the surface of the release sheet and a lens portion that is an aggregate thereof. The unit lens shape and the lens shape portion that is an aggregate thereof are provided on the surface. And the reflected light which arises in the lens-shaped part of resin leather can show the scattering distribution provided with the characteristic of both the optical characteristic by a smooth surface, and the optical characteristic by a fine uneven | corrugated shaped surface.
That is, as shown in FIG. 4C, the reflected light generated in the lens-shaped portion has a steep gradient of the scattered light intensity distribution curve P, and the scattered light intensity has a small anisotropy, but the maximum scattered light. Since the range of the scattering angle θ that is a half of the light intensity L _max is large, the calculated diffusion angle FWHM is large.
For this reason, the resin leather obtained by the release sheet according to the present embodiment has a wide observation area where the glossiness can be visually recognized. In addition, the resin leather expresses a high gloss feeling with reduced shine when the observation area is within the range of the diffusion angle, and on the other hand, if the observation area is out of the range of the diffusion angle, the gloss feeling is lost. Decreases rapidly.
As described above, the resin leather obtained from the release sheet according to the present embodiment has a gloss distribution in which the reflected light is scattered by the lens-shaped portion on the surface, and thus shows a glossy feeling with reduced shine, depending on the observation region. Thus, it is possible to exhibit design properties due to changes in glossiness.

In the release sheet according to the present embodiment, the resin leather obtained by designing the curved surface shape of the plurality of unit lenses provided on the surface of the release layer, the arrangement mode of the unit lenses, and the lens portion that is an aggregate thereof is designed. It is possible to show a desired scattering distribution.
In addition, about the scattering distribution which the resin leather obtained using the release sheet which concerns on this embodiment shows, it demonstrates in the term of the "B. resin leather" mentioned later.

In the present specification, the scattered light intensity and the scattered light intensity distribution curve can be measured and drawn by the following method. The scattered light intensity is measured using a three-dimensional variable angle spectrophotometric color measurement system (GCMS-13, manufactured by Murakami Color Research Laboratory Co., Ltd.) with an incident angle of 0 ° (ie, vertical direction) with respect to the target surface. Incident light can be measured for scattered light intensity for each scattering angle under the condition of a light receiving angle within a range of −60 ° to 60 ° and a variable angle interval of 1 °. Then, the scattered light intensity distribution curve can be drawn by plotting the scattered light intensity value for each scattering angle with the scattering angle on the X axis and the scattered light intensity on the Y axis.
The diffusion angle is obtained by calculating a half-value width, which is a difference in scattering angle at which the scattered light intensity is ½ of the maximum scattered light intensity, from the obtained scattered light intensity distribution curve.

In the release sheet according to the present embodiment, when the plurality of unit lenses constituting the lens portion are convex with respect to the surface of the release layer, that is, as shown in FIG. In the case of a convex shape that protrudes from the surface to the side opposite to the base material side, the obtained resin leather has a concave unit lens shape that is recessed inward with respect to the surface. On the other hand, when the plurality of unit lenses constituting the lens portion are concave with respect to the surface of the release layer, that is, as shown in FIG. 2, they are recessed from the surface of the release layer toward the substrate. In the case of the oval shape, the obtained resin leather has a convex unit lens shape protruding from the surface.
Regardless of whether the unit lens in the release sheet according to the present embodiment is concave or convex, in the obtained resin leather, the direction of the unevenness and the position of the focal point of the unit lens shape, that is, the focal point of each unit lens shape The only difference is whether it is located inside or outside the resin leather, and in either case, it is possible to adjust the scattering distribution of reflected light based on the above-mentioned principle using the curved surface of the unit lens shape In the resulting resin leather, it is possible to produce a high glossiness with reduced shine and a change in glossiness depending on the observation region.

  Hereinafter, each structure of the release sheet which concerns on this embodiment is demonstrated.

1. Release layer The release layer in the release sheet according to the present embodiment has a lens portion formed (arranged) on the substrate and having a plurality of unit lenses each having a curved surface on the surface.
Hereinafter, the surface provided with the lens portion in the surface of the release layer may be referred to as “lens portion forming surface (of the release layer)”.

(1) Lens part The lens part in the said release layer comprises a plurality of unit lenses having a curved surface.

  The unit lens only needs to have a curved surface, and may be convex or concave with respect to the lens portion forming surface of the release layer. When the unit lens has a convex shape with respect to the lens part forming surface of the release layer, the focal point of the unit lens is located inside the release layer or the base material. On the other hand, when the unit lens has a concave shape with respect to the lens portion forming surface of the release layer, the focal point of the unit lens is located outside the release layer side of the release sheet.

  Especially in this embodiment, it is preferable that the said unit lens is convex shape with respect to the surface of the said mold release layer. That is, it is preferable that the focal point of the unit lens is located inside the release layer or the base material. The unit lens has a convex shape protruding outward from the surface of the release layer, and the resin leather produced by the release sheet according to the present embodiment has a concave unit lens shape on the surface. It will be. For this reason, the obtained resin leather not only allows a desired design property to be expressed by the lens shape portion molded on the surface thereof, but also compared with a case where a convex unit lens shape is molded. This is because the amount of material can be reduced.

The unit lens may be a spherical lens or an aspheric lens.
Specific examples of such unit lenses include micro lenses, cylindrical lenses, Fresnel lenses, and toric lenses.

  The planar view shape of the unit lens is not particularly limited, and is appropriately designed according to the type of the unit lens. For example, a circle, a rectangle such as a rectangle or a square, a polygon, a triangle, and the like can be given.

  Further, the cross-sectional shape in the thickness direction of the unit lens (hereinafter simply referred to as a cross-sectional shape) may be symmetrical with respect to the central axis Y of the unit lens 3a as illustrated in FIG. As illustrated in FIG. 5B, the design may be asymmetric with respect to the central axis Y of the unit lens 3a, and the design required for the resin leather obtained by the release sheet according to the present embodiment. It can design suitably according to.

For example, if the cross-sectional shapes of the plurality of unit lenses are all symmetrical, the scattering distribution of reflected light expressed by each unit lens shape can also have symmetry in the obtained resin leather. That is, in the obtained resin leather, since the scattering distribution of the reflected light generated by the lens shape portion is symmetric, the same glossiness is exhibited when viewed from two directions that are symmetrical with respect to the central axis of the unit lens shape.
On the other hand, if the cross-sectional shape of the plurality of unit lenses is an asymmetric shape, the scattering distribution of the reflected light expressed by each unit lens shape can also be asymmetric in the obtained resin leather. That is, in the obtained resin leather, the scattering distribution of the reflected light generated by the lens shape portion is asymmetric, so that when viewed from two directions that are symmetrical with respect to the central axis of the lens shape, one side shows a high gloss feeling. On the other hand, on the other hand, the design property expressed can be varied by showing a low gloss feeling.

  The cross-sectional shape of the unit lens refers to a shape of the unit lens viewed from the width direction, and the central axis of the unit lens refers to an axis that passes through the middle of the width of the unit lens (O in FIG. 5). Similarly, the central axis of the lens shape in the resin leather is an axis passing through the middle of the width of the lens shape.

  The width of the unit lens may be any size as long as the scattering distribution of reflected light can be adjusted on the surface of the resin leather obtained by the release sheet according to the present embodiment, and is preferably 300 μm or less, for example, 100 μm or less. In particular, it is preferably 80 μm or less. The width is preferably 30 μm or more. When the width of the unit lens is larger than the above range, the shape of the unit lens provided on the surface of the resin leather obtained by the release sheet according to the present embodiment is easily visible, and the design of the resin leather may be impaired. . On the other hand, if the width of the unit lens is smaller than the above range, the manufacturing difficulty may be increased even though the function of the unit lens and the shape of the unit lens on the surface of the resin leather formed thereby is hardly changed.

The width of the unit lens refers to the width W of the base portion of the unit lens, as illustrated in FIGS. 1B and 2B. For example, when the planar view shape of the unit lens is a circle like a microlens, the width of the unit lens indicates the diameter of the circle. Further, when the planar view shape of the unit lens is a quadrangle as in the case of a cylindrical lens, the width of the unit lens indicates the length of the unit lens in the short direction.
The base part of a unit lens means a part where the outline of one unit lens is switched to the outline of the other unit lens when the adjacent unit lenses are arranged without a gap. In this case, it means a portion where the flat surface is switched to the contour of the unit lens. The root portion is a portion indicated by C in FIGS. 1 (b) and 2 (b). When the interval between adjacent unit lenses is not flat but curved, the inflection point of the outline near the base of the unit lens in the cross section perpendicular to the direction in which the unit lens extends is defined as the base of the unit lens. can do.

The thickness of the unit lens may be a size that allows adjustment of the scattering distribution of reflected light on the surface of the resin leather obtained by the release sheet according to the present embodiment, and depends on the width and shape of the unit lens. Are adjusted accordingly.
Specifically, the thickness of the unit lens is preferably in the range of 10 μm to 150 μm, more preferably in the range of 15 μm to 150 μm, and particularly preferably in the range of 15 μm to 40 μm. . If the thickness of the unit lens is larger than the above range, transfer may not be possible because it is larger than the thickness of the release layer of the release sheet. On the other hand, if the thickness of the unit lens is smaller than the above range, the unit lens is formed. Even though the function of the unit lens shape on the surface of the resin leather is almost the same, the manufacturing difficulty level may increase.
Here, the unit lens thickness means the length from the root portion to the top when it is a convex unit lens, and the length from the root portion to the bottom when it is a concave unit lens. FIG. 1B is a portion indicated by D in FIG. 1B and FIG.

The unit lens only needs to have a curved surface capable of adjusting the scattering distribution of reflected light in the resin leather obtained from the release sheet according to the present embodiment, and can be appropriately set according to the shape of the unit lens and the like. it can. The unit lens has a curved surface as long as the radius of curvature of the unit lens is within a range of 15 μm to 150 μm (15 μm to 150 μm), and is preferably within a range of 15 μm to 40 μm (15 μm to 40 μm). . If the cross-sectional shape of the unit lens is an asymmetric shape, it is preferable that the radius of curvature at the portion where the curvature is smallest is within the above range.
The surface of the unit lens only needs to have at least a curved surface showing the above-described radius of curvature, and a part of the surface may include a flat surface.

  The width, thickness, and radius of curvature of the unit lens can be measured by obtaining a cross-sectional profile with a laser microscope, AFM, SEM, or the like. For example, using a laser microscope (OLS4000 manufactured by OLYMPUS), obtain height data by laser microscope observation in the shooting mode, display the cross-sectional profile in the measurement mode, and align the cursor, so that the width and thickness of the unit lens The radius of curvature can be calculated.

The lens unit includes a plurality of unit lenses.
In the lens unit, all of the plurality of unit lenses to be arranged may have the same shape and the same size, or a plurality of types of unit lenses having different shapes and dimensions may be arranged in a mixed manner.
Further, when a plurality of types of unit lenses having different shapes and dimensions are arranged in a mixed manner, the different types of unit lenses may be arranged with a certain regularity or may be arranged without any regularity. .

The plurality of unit lenses to be arranged may all have a symmetric cross-sectional shape in the thickness direction, or a part of the unit lenses having an asymmetric cross-sectional shape may be included.
About the number of unit lenses arrange | positioned, it can select suitably according to the use and design property of the resin leather obtained by the release sheet which concerns on this embodiment.

  In the lens part, all of the plurality of unit lenses may be convex with respect to the lens part forming surface of the release layer, and all of the plurality of unit lenses are concave with respect to the lens part forming surface of the release layer. It may be a shape. In particular, in the present embodiment, it is preferable that all of the plurality of unit lenses have a convex shape with respect to the lens portion forming surface of the release layer. That is, the focal points of the plurality of unit lenses are preferably located inside the release layer or the base material. The reason is as described above.

In the lens unit, the plurality of unit lenses may be arranged without a gap so that the bases of the neighboring unit lenses are in contact with each other, and the neighboring unit lenses are arranged with a desired gap between them. It may be selected as appropriate according to the dimensions of the unit lens, the forming method, the design required for the resin leather obtained from the release sheet according to the present embodiment, and the like. Usually, it is preferable that the plurality of unit lenses are arranged without being spaced apart.
When adjacent unit lenses are arranged with an interval between them, the interval is appropriately set within a range that satisfies the width and arrangement pitch of the unit lenses.

As the arrangement pitch of the unit lenses, it is only necessary to be able to adjust the scattering distribution of the reflected light on the surface of the resin leather obtained by the release sheet according to the present embodiment. The size is preferred. For example, the arrangement pitch is preferably 1 to 5 times the unit lens width, and more preferably 1 to 2 times, particularly 1 time. When the arrangement pitch is larger than the above range, the flat portion increases on the surface of the release layer, so that the optical characteristics of the obtained resin leather may be deteriorated. In addition, it is difficult to design the arrangement pitch to be smaller than the above range.
The unit lens arrangement pitch is a portion indicated by P in FIGS. 1B and 2B. When adjacent unit lenses are arranged without a gap, the arrangement pitch of the unit lenses is equal to the width of the unit lens.

The arrangement of the plurality of unit lenses in the lens unit is not particularly limited as long as the arrangement of the reflected light scattering distribution can be adjusted on the surface of the resin leather obtained from the release sheet according to the present embodiment. A one-dimensional array or a two-dimensional array can be appropriately designed according to the shape of the unit lens.
Here, the one-dimensional arrangement means that, for example, a plurality of unit lenses 3a (cylindrical lenses) are arranged in a one-dimensional direction on the lens portion forming surface of the release layer 2 as illustrated in FIGS. 6 (a) and 6 (b). The arrangement | positioning aspect arranged. The lens portion having such an arrangement mode is called a lenticular lens. 6A is a schematic perspective view illustrating another example of the release sheet according to the present embodiment, and FIG. 6B is a cross-sectional view taken along the line XX of FIG. 6A.
On the other hand, the two-dimensional array is, for example, as illustrated in FIG. 1 and FIG. This refers to an arrangement mode arranged in the vertical and horizontal directions. The lens portion having such an arrangement mode is called a microlens array. As a two-dimensional array, cylindrical lenses may be arranged in a pattern in the two-dimensional direction as unit lenses.
The two-dimensional arrangement mode of the unit lenses is not particularly limited, and may be a square lattice arrangement as exemplified in FIGS. 1 and 2, for example, a staggered arrangement, a hexagonal close arrangement, or the like.
Note that the arrangement pitch of the unit lenses may be different, the different pitches may have a certain regularity, or may not have regularity.

(2) Release layer The release layer is usually formed of a resin. As the resin, a desired unit lens can be molded, and when the resin leather is produced using the release sheet according to the present embodiment, any resin can be used as long as the resin leather can be easily peeled off. For example, a thermoplastic resin and a cured resin can be used. The curable resin refers to a resin (thermosetting resin) obtained by heating and curing a thermosetting resin, or a resin (ionizing radiation curable resin) obtained by curing an ionizing radiation curable resin by irradiation with ionizing radiation. Examples of the ionizing radiation curable resin include an ultraviolet curable resin and an electron beam curable resin.
Here, “ionizing radiation” refers to radiation having an energy quantum capable of polymerizing or crosslinking molecules among electromagnetic waves or charged particle beams. For example, in addition to ultraviolet rays and electron beams, electromagnetic waves such as X rays and γ rays are used. And charged particle beams such as α rays and ion rays. Of these, ultraviolet rays and electron beams are preferred.

  Examples of the thermoplastic resin include acrylic resins such as polymethyl methacrylate; polyolefin resins such as polyethylene, polypropylene, and polymethylpentene; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; styrene resins such as polystyrene; Conventional resins such as vinyl resins such as vinyl chloride, polycarbonate resins, silicone resins, polyvinyl alcohol, and copolymers disclosed in JP-A-2015-27811 can be used.

Examples of the thermosetting resin include unsaturated polyester, melamine, epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine ( And (meth) acrylate and triazine acrylate.
Examples of the ionizing radiation curable resin include urethane resins, epoxy resins, ester resins, acrylic resins, acrylic ester copolymers, and the like.

  Especially, it is preferable that the said resin is a thermoplastic resin, and it is more preferable that it is a polypropylene. The desired unit lens can be accurately attached to the surface of the release layer, and when the resin leather is produced using the release sheet according to the present embodiment, the peelability from the resin leather is improved. is there.

  The release layer may be transparent, translucent or opaque. The release layer may be colored.

  The thickness of the release layer may be any thickness as long as it can have a unit lens of a desired shape and a lens portion that is an aggregate thereof on the surface, for example, in the range of 1 μm to 200 μm, especially 20 μm to Within the range of 50 μm is preferable. If the thickness of the release layer is larger than the above range, the amount of material used for forming the release layer and its cost, and the manufacturing cost of the entire release sheet may increase, whereas it is smaller than the above range. In some cases, a unit lens having a desired shape and a lens portion that is an aggregate thereof cannot be provided. Note that the thickness of the release layer is a portion indicated by T in FIGS. 1B and 2B.

Further, a release layer may be provided on the lens portion forming surface of the release layer. This is because the peelability can be increased during the production of the resin leather. Examples of the material for the release layer include silicone resins and fluorine resins, and these resins can be formed by applying them to the lens portion forming surface of the release layer and drying them.
The thickness of the release layer may be any thickness that does not impair the shape of the lens portion forming surface of the release layer, and is preferably about 0.1 μm to 3 μm, for example. This is because if it is below the above range, the peeling force may be insufficient, while if it is above the above range, the difference in shape becomes large.
Moreover, you may make a release layer contain a mold release agent instead of providing a peeling layer. Examples of the mold release agent include conventionally known materials. For example, a mold release agent disclosed in JP-A-2015-039847 can be used.

The release layer is a scatter when the scattered light intensity is 20% in the scattered light intensity distribution curve with respect to the scattering angle when light is incident on the lens part (lens part forming surface) from the vertical direction (incident angle 0 °). The absolute value S _(80-20) of the difference between the angle and the scattering angle when the scattered light intensity is 80% is preferably 4 ° or more and 15 ° or less, and S _(80-20) is preferably 4 ° or more and 8 or less. More preferably, it is not more than 0 °.
When the S _(80-20) value is within the above range, the scattered light intensity distribution curve has a steep gradient, and the anisotropy of the scattered light intensity of the reflected light becomes small. For this reason, also in the resin leather obtained using the release sheet according to the present embodiment, the scattered light intensity distribution curve shows the same gradient, and the anisotropy of the scattered light intensity is reduced. Thereby, it becomes possible for the said resin leather to express desired designability.
When the S _(80-20) value of the release layer is larger than the above range, the gradient of the scattered light intensity distribution curve becomes gentle and the anisotropy of the scattered light intensity increases. For this reason, the resin leather obtained using the release sheet according to the present embodiment also has a high anisotropy in scattered light intensity and a greater influence due to diffuse reflection. Expression becomes difficult. On the other hand, when S _(80-20) of the release layer is smaller than the above range, it is difficult to mold a lens portion having a desired shape.
FIG. 7 is an explanatory diagram for explaining the difference between the scattering angle when the scattered light intensity is 20% and the scattering angle when the scattered light intensity is 80% in the scattered light intensity distribution curve.

  The release layer preferably has a light diffusion angle at the lens portion (lens portion forming surface) of greater than 5 ° and 90 ° or less, and more preferably 10 ° or more and 60 ° or less. When the diffusion angle exceeds the above range, the influence due to diffuse reflection becomes large. On the other hand, when the diffusion angle falls below the above range, the influence due to specular reflection becomes large. Therefore, it is obtained using the release sheet according to this embodiment. It becomes difficult for the resin leather to be obtained to exhibit desired design properties. The diffusion angle of light at the lens portion (lens portion forming surface) is a diffusion angle when light is incident on the lens portion (lens portion forming surface) from the vertical direction (incident angle 0 °).

2. Base material The base material in the release sheet which concerns on this embodiment supports a release layer.
The base material is not particularly limited as long as a release layer can be formed, and examples thereof include conventionally known base materials used for release sheets for resin leather production and process paper. Specifically, a nonwoven fabric, a woven fabric, or these laminated bodies are mentioned. Use paper such as kraft paper, high-quality paper, cast coated paper, polyester such as polyethylene terephthalate and polyethylene naphthalate, polyamide such as various nylons, resin film such as polypropylene, synthetic paper, metal foil, woven fabric, non-woven fabric, etc. Can do. These can be used alone or appropriately laminated.
Among these, paper is preferable as the substrate because the resin leather is less likely to be thermally deteriorated and has high adhesion to the release layer when the release leather according to this embodiment is used.

  Moreover, when the said base material is a resin film, resin used for a resin film may be the same as resin which forms the mold release layer mentioned above. In this case, the substrate and the release layer may be integrated.

  It does not specifically limit about the thickness of the said base material, Although it can set suitably according to the material etc. of a base material, For example, it is preferable to set within the range of 50 micrometers-200 micrometers.

  Even if the surface of the release layer side of the substrate is subjected to surface treatment such as corona discharge treatment, easy adhesion treatment such as ozone treatment or primer coating for the purpose of improving adhesion with the release layer. Good.

3. Arbitrary Layer The release sheet according to the present embodiment has a release layer having a lens part formed on at least the surface thereof and a base material, but may have an optional layer as necessary.
For example, when the surface of the substrate is not smooth, a smoothness improving layer may be provided between the substrate and the release layer so that the release layer can be formed uniformly. As a smoothness improvement layer, the smoothness improvement layer which consists of a composition disclosed by Unexamined-Japanese-Patent No. 2002-086622 etc., a clay coat layer, etc. are mentioned, for example.
Moreover, you may have a contact | adherence layer between a base material and a mold release layer. This is because the adhesion between the substrate and the release layer can be improved. Examples of the material for the primer layer include a fluorine-based coating agent and a silane coupling agent.

4). Others In the release sheet according to the present embodiment, the release layer and the substrate may be integrated. That the release layer and the base material are integral means that the release layer 2 and the base material 1 are a single layer 5 made of the same material, as illustrated in FIGS. 8A and 8B. Say. Examples of the material constituting the single layer include the materials described in the section “1. Release layer”.
Since the lens portion and the like in the release sheet in which the release layer and the base material are integrated are the same as those already described, description thereof is omitted here.

5. Optical Characteristics In the release sheet according to the present embodiment, the scattering distribution of the light reflected on the lens portion forming surface is adjusted by the unit lens provided on the surface and the lens portion that is an aggregate thereof.
Release sheet according to the present embodiment, the diffusion angle of S _(80-20) and light at the lens forming surface is, S is described in the section "1. release layer" described above _(80-20) and It is preferable to show the diffusion angle of light. The reason for this has been described in the above section “1.

6). Another aspect of the release sheet according to the present embodiment The other aspect of the release sheet according to the present embodiment has a lens portion including a plurality of unit lenses having curved surfaces on the surface, and the curvature radius of the unit lens is It is 15 μm or more and 150 μm or less.
The release sheet according to the present embodiment includes a plurality of unit lenses each having a radius of curvature within a predetermined range, and the above-described S _(80-20) and the comparison diffusion angle are obtained. Each can be within a predetermined range. As a result, the resin leather obtained from the release sheet according to the present embodiment adjusts the scattering distribution of the reflected light generated on the surface, and thus exhibits a high glossiness with reduced shine and glossiness depending on the observation region. The design property by the change of can be expressed.
The details of the release sheet of the other aspect are as described above.

7). Release Sheet Manufacturing Method A release sheet manufacturing method according to this embodiment includes a plurality of unit lenses having a desired shape and an assembly thereof on the surface of a release layer formed on one surface of a substrate. The method is not particularly limited as long as it can attach a certain lens portion, and can be appropriately selected according to the material used for forming the release layer.
For example, if the resin contained in the release layer forming composition is an ionizing radiation curable resin, after applying the release layer forming composition to one surface of the substrate, the coating layer is formed into a desired unit lens shape. A release layer having a lens portion on the surface can be formed by pressing a transfer plate on which a corresponding concave portion or convex portion is formed and irradiating with an ionizing radiation to cure.
On the other hand, if the resin contained in the release layer forming composition is a thermoplastic resin, it corresponds to the shape of the desired unit lens while extruding and laminating the resin as the release layer forming composition on the substrate surface. A method of forming a release layer having a lens portion on the surface can be used by pressing a transfer plate on which concave portions or convex portions are formed. Also, after applying the release layer forming composition to one surface of the substrate, the surface is heated and pressed with a transfer plate in which a concave or convex portion corresponding to the shape of the desired unit lens is formed on the coating layer. For example, a method of forming a release layer having a lens portion on the surface can be used.

8). Applications The release sheet according to the present embodiment can be suitably used as a process release paper in the production of resin leather such as synthetic leather and artificial leather, but is not limited thereto. The release sheet according to the present embodiment can be used, for example, as a mold for producing rubber sheets, carbon sheets, other resin sheets, and films, in addition to the use as a release sheet for producing resin leather.

B. Resin leather A resin leather according to an embodiment of the present invention (hereinafter sometimes referred to as a resin leather according to the present embodiment) has a support layer and a plurality of unit lens shapes having curved surfaces arranged on the support layer. And a resin skin layer provided on the surface with the lens-shaped portion thus formed.

The resin leather according to this embodiment will be described with reference to the drawings. 9 (a) and 10 (a) are schematic perspective views showing an example and other examples of the resin leather according to the present embodiment, and FIGS. 9 (b) and 10 (b) are FIG. 9 (a). FIG. 11 is a sectional view taken along line XX in FIG. The resin leather 20 includes a support layer 11 and a resin skin layer 12 that is disposed on the support layer 11 and includes a lens-shaped portion 13 having a plurality of unit lens shapes 13a each having a curved surface.
FIG. 9 shows an example in which the unit lens shape 13 a is a convex curved surface shape protruding from the surface of the resin leather layer 12. FIG. 10 shows an example in which the unit lens shape 13 a is a concave curved surface shape recessed from the surface of the resin leather layer 12. 9 and 10, the lens shape portion 13 has a microlens array shape.

  According to the resin leather according to the present embodiment, the resin skin layer surface of the resin leather is provided with a lens shape portion in which a plurality of unit lens shapes having curved surfaces are arranged, and the scattered distribution of reflected light by the lens shape portion. As a result, the glossiness is suppressed, and a high glossiness with suppressed glossiness is exhibited, and a design property due to a change in glossiness can be exhibited depending on the observation region.

  Hereinafter, the resin leather according to this embodiment will be described for each configuration.

1. Resin skin layer The resin skin layer in the resin leather according to the present embodiment is formed (arranged) on the support layer, and has a lens-shaped portion on the surface, in which a plurality of unit lens shapes having curved surfaces are arranged.
The resin skin layer has a texture and color similar to natural leather as the skin of the resin leather.

  The unit lens shape and the lens shape portion in the resin skin layer are the same as the unit lens and the lens portion included in the release layer described in the section “A. Release Sheet”, and thus description thereof is omitted here.

  In particular, in the present embodiment, as illustrated in FIG. 10, the plurality of unit lens shapes are preferably concave with respect to the surface of the resin skin layer. By making the plurality of unit lens shapes concave, the desired shape is expressed by the lens shape part, and the amount of material used for the resin skin layer can be reduced compared to the case of having a convex unit lens shape. It is because it can plan.

As the resin used for the resin skin layer, a rigid resin used for production of general synthetic leather or artificial leather can be applied, and examples thereof include nylon, polyurethane, and polyvinyl chloride. The resin may be used alone or in combination of two or more.
The resin skin layer may contain additives such as a plasticizer, a stabilizer, and a colorant.

  The thickness of the resin skin layer is not particularly limited as long as it is a thickness that can provide a desired unit lens shape and a lens shape portion that is an aggregate thereof. Can do.

2. Support layer The support layer in the resin leather according to the present embodiment supports the resin skin layer.
As the support layer, natural fibers such as cotton, hemp and wool, regenerated or semi-synthetic fibers such as rayon and acetate, woven fabrics and nonwoven fabrics made of synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl alcohol and polyolefin, From materials used for synthetic leather and artificial leather, such as net cloth, paper, polyester and polyolefin resin films, metal plates, metal foils, glass plates, glass woven fabrics, etc., depending on the type and application of resin leather can do.
The thickness of the support layer is not particularly limited as long as it can support the resin skin layer.

3. Others The resin leather according to the present embodiment suppresses shine due to adjustment of the scattering distribution of the reflected light such as the anisotropy of the scattered light intensity of the reflected light and the size of the diffusion angle by the lens-shaped portion provided on the surface. High glossiness can be exhibited, and design properties due to changes in glossiness can be exhibited depending on the observation region.

In the resin leather according to this embodiment, the resin skin layer and the support layer may be integrated. That the resin skin layer and the support layer are integral means that the release layer and the substrate are a single layer formed of the same material. Examples of the material constituting the single layer include the materials described in the section “1. Resin skin layer”.
Since the lens shape portion and the like in the resin leather in which the resin skin layer and the support layer are integrated are the same as those already described, description thereof is omitted here.

The resin leather according to the present embodiment preferably has a small anisotropy of scattered light intensity of reflected light generated at the lens shape portion. “The scattered light intensity anisotropy is small” means that “the scattered light intensity distribution curve has a steep slope”.
Specifically, the scattered light intensity is 20 in the scattered light intensity distribution curve with respect to the scattering angle when light is incident on the lens shape portion (surface having the lens shape portion) of the resin leather from the vertical direction (incident angle 0 °). It is preferable that the absolute value S _(80-20) of the difference between the scattering angle at the time of% and the scattering angle at the time of the scattered light intensity of 80% is 4 ° or more and 15 ° or less, and among them, S _(80-20) Is more preferably 4 ° or more and 8 ° or less. The greater the S _(80-20) value, the _gentler the gradient of the scattered light intensity distribution curve and the greater the anisotropy of the scattered light intensity, and the greater the influence of diffuse reflection. Therefore, the resin leather has a reduced glossiness and a whited color, making it difficult to develop a highly glossy design. On the other hand, when S _(80-20) is smaller than the above range, it is difficult to have a lens shape portion having a desired shape on the surface of the resin leather.

Moreover, the resin leather which concerns on this embodiment can show high glossiness in a desired observation area | region. The observation region where the high glossiness of the resin leather can be visually recognized means “within the range of the diffusion angle at the lens shape portion of the resin leather”.
Specifically, it is preferable that the light diffusion angle in the lens shape part (surface provided with the lens shape part) of the resin leather is greater than 5 ° and 90 ° or less, and more preferably 10 ° or more and 60 ° or less. It is preferable. If the diffusion angle at the lens-shaped part of the resin leather exceeds the above range, the influence of diffuse reflection increases and it may be difficult to obtain a high gloss feeling. On the other hand, if the diffusion angle is less than the above range, the effect of specular reflection becomes large, and there is a case where shine is more easily recognized than a high gloss feeling. The diffusion angle of light at the lens shape portion is a diffusion angle when light is incident on the lens shape portion from the vertical direction (incident angle 0 °).
The observer can visually recognize the high glossiness of the resin leather within the observation angle region corresponding to the diffusion angle.

4). Another aspect of the resin leather according to the present embodiment Another aspect of the resin leather according to the present embodiment has a lens shape portion on the surface having a plurality of unit lens shapes having curved surfaces, and the curvature radius of the unit lens shape is 15 μm or more and 150 μm or less.
The resin leather according to this embodiment includes a plurality of unit lens shapes each having a curvature radius within a predetermined range, and the above-described S _(80-20) and comparative diffusion angle. Can be within a predetermined range. As a result, the resin leather according to the present embodiment adjusts the scattering distribution of the reflected light generated on the surface, and thus exhibits a high gloss feeling with reduced shine, and exhibits a design property due to a change in the gloss feeling according to the observation region. Can be expressed.
The details of the resin leather of the other aspect are as described above.

5. Method for Producing Resin Leather As a method for producing resin leather according to the present embodiment, the release sheet described in the section “A. Release Sheet” is used, and a desired unit lens shape on the resin skin layer surface of the resin leather and The method is not particularly limited as long as it is a method capable of forming a lens shape portion as an aggregate, and a conventionally known method for producing synthetic leather or artificial leather using a release sheet can be used. The method for producing the resin leather may be a dry method or a wet method.
For example, in the case of producing resin leather by a dry method, the resin skin layer forming composition is applied to the surface of the release layer of the release sheet described in the section “A. Release sheet” and dried to obtain a resin skin layer. The resin leather can be manufactured by laminating the support layer via the adhesive layer on the resin skin layer, drying and aging, and then releasing the release sheet. As the adhesive layer, a conventionally known composition used for the production of resin leather can be used.

The composition for forming the resin skin layer is not particularly limited as long as a desired resin skin layer can be formed, and is appropriately selected depending on the type of the resin leather.
For example, when the resin leather is polyurethane leather, a polyurethane paste having a solid content of about 20% by mass to 50% by mass including polyurethane and an optional additive is used as the resin skin layer forming composition. When the resin leather is polyvinyl chloride leather, a sol or the like containing polyvinyl chloride and optional additives is used as the resin skin layer forming composition.
As a coating method of the resin skin layer forming composition, a known method can be used depending on the composition of the resin skin layer forming composition.

6). Applications The resin leather according to this embodiment can be used for applications in which synthetic leather is generally used. It can also be used as a substitute for natural leather. Specific applications include clothing materials, bags, shoes, wallets, smartphone cover skin materials, interior materials, instrument panel materials, car seat skin materials, steering wheel skin materials, and motorcycle seat materials. Etc. FIGS. 11A and 11B and FIGS. 11C and 11D are schematic views showing examples of the bag 50 and the instrument panel material 60 using the resin leather of the present embodiment, respectively. FIGS. 11B and 11D correspond to YY line cross-sectional views of FIGS. 11A and 11C, respectively.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Examples 1 to 10 and Comparative Examples 1 and 2]
1. Preparation of Transfer Plate Transfer plates used in Examples 1 to 10 and transfer plates used in Comparative Examples 1 and 2 were produced by the following method.

(Transfer plates 1 to 10 used in Examples 1 to 10)
On the surface of the copper plated cylinder (diameter: 100 mmφ, width 300 mm), a pattern corresponding to the reversal shape of the unit lens shape of Example 1 shown in Table 1 is formed by mechanical cutting, and then the surface is transferred by chromium plating. Version 1 was obtained. Transfer plates 2 to 10 used in Examples 2 to 10 were also obtained in the same manner.
For each example, the transfer plate was attached to a roll embossing device.

(Transfer plates 11-12 used in Comparative Examples 1-2)
After the surface of the copper-plated cylinder (diameter: 100 mmφ, width 300 mm) was subjected to chrome plating, the treated surface was roughened by sandblasting so as to have the surface roughness of Comparative Example 1 shown in Table 2 to obtain a transfer plate 11. The transfer plate 12 used in Comparative Example 2 was obtained in the same manner.
For each comparative example, a transfer plate was attached to a roll embossing device.

2. Production of release sheet Polypropylene is applied on one side of a paper substrate (thickness 150 μm) to form a release layer with a thickness of 50 μm, and transferred to the release layer under the following conditions. The plate 1 was heated and pressed to transfer the pattern to obtain a release sheet of Example 1 (raw width 300 mm). A release sheet was obtained in the same manner for Examples 2 to 10 and Comparative Examples 1 and 2.
(Transfer conditions)
・ Cylinder temperature: 120 ℃
・ Pressing force: 150 kgf / cm
・ Conveying speed: 5m / min
Table 1 and Table 2 show the shape and details of the release layer surface of the obtained release sheet. The release sheets obtained in Examples 1 to 10 were provided with lenticular lenses, which are aggregates of cylindrical lenses (unit lenses), as lens portions on the surface of the release layer. Moreover, the release sheet obtained in Comparative Examples 1 and 2 was a blast rough surface having a predetermined surface roughness on the release layer surface.

3. Production of Resin Leather (Synthetic Leather) Using each release sheet obtained in Examples 1 to 10 and Comparative Examples 1 and 2, the following is provided as a resin skin layer forming composition on the release layer of each release sheet. A polyurethane composition for a skin layer of a synthetic leather having the composition described above was applied by a bar coating method and dried by heating within a range of 100 ° C. to 120 ° C. for 2 minutes. Thereafter, a base fabric (support layer) was bonded onto the coating layer using an adhesive, and after drying and aging, the release sheet was peeled off to obtain a synthetic leather.
(Resin skin layer forming composition)
・ Polyurethane (Resamine NE-8811 manufactured by Dainichi Seika Kogyo Co., Ltd.): 100 parts by weight Colorant (Seika Seven NET-5794 Black, manufactured by Dainichi Seika Kogyo Co., Ltd.): 15 parts by weightToluene: 25 parts by weight Isopropyl alcohol (IPA): 25 parts by weight

4). Evaluation The following evaluation was performed about the synthetic leather obtained using the release sheet obtained in Examples 1-10 and Comparative Examples 1-2. Each evaluation result is shown in Table 1 and Table 2.

(1) Polyurethane use amount The release amount of Examples 2-10 and Comparative Examples 1-2 when the polyurethane amount (including the colorant) of the synthetic leather obtained using the release sheet of Example 1 is 1. The amount of polyurethane (including the colorant) in the synthetic leather obtained using the sheet was measured as a weight ratio.

(2) Diffusion angle and S _(80-20) value For synthetic leather obtained using the release sheets obtained in Examples 1 to 10 and Comparative Examples 1 and 2, the scattered light intensity was measured and obtained. The diffusion angle and S _(80-20) value were calculated from the scattered light intensity distribution curve. The scattered light intensity is measured in a vertical direction (incidence angle 0) with respect to the surface having the lens-shaped portion of the resin leather using a three-dimensional variable angle spectral colorimetry system (GCMS-13 type, manufactured by Murakami Color Research Laboratory Co., Ltd.). The intensity at each scattering angle was measured under the condition that the light receiving angle was in the range of −60 ° to 60 ° and the variable angle interval was 1 °. The scattered light intensity distribution curve was drawn by plotting the scattered light intensity for each scattering angle, with the scattering angle on the X axis and the scattered light intensity on the Y axis.

(3) Visibility of unit lens shape A sample of 100 mm square was cut out from the synthetic leather obtained using the release sheets of Examples 1 to 10, and the sample was placed on a desk. Identification was performed.
Further, a 100 mm square sample was cut out from the synthetic leather obtained using the release sheets of Comparative Examples 1 and 2, and the above sample was placed on a desk, and the uneven shape of the blast rough surface was identified from a position 500 mm above. .
The test environment was an illuminance of 400 lux (equivalent to a bright office). The number of persons visible from 10 subjects (from 20s to 60s) was counted and determined as follows.
◎◎: 0 (not visible at all)
A: 1-2 people (almost invisible)
○: 3-7 people (slightly visible)
Δ: 8 or more (visible)

(4) Appearance Evaluation Each sample used in “(3) Visibility of unit lens shape” was placed on a desk, and the appearance of the sample was confirmed under an environment with an illuminance of 400 lux (equivalent to a bright office). Of the 10 subjects (from 20s to 60s), the number of people who felt that the glossiness was high was 7 or more, and the sample was “high glossiness (high glossiness)”. Regarding the feeling of shine, a sample of 10 subjects (from 20's to 60's) who had a strong feeling of shine was 7 or more was designated as “has a sense of shine”.

As a result of the external appearance evaluation, the release sheets of Examples 1 to 10 are provided with a lens portion on the surface of which a plurality of unit lenses having curved surfaces are arranged, and thus synthetic leather obtained using the release sheet. , A high gloss feeling in which shine was suppressed was observed, and the appearance of design properties due to a change in the gloss feeling depending on the observation region was confirmed. On the other hand, the release sheets of Comparative Examples 1 and 2 do not have a curved unit lens and a lens part that is an aggregate thereof, and the synthetic leather obtained using the release sheet has a high glossiness. No white color was observed, and the appearance of design due to a change in glossiness according to the observation region was not confirmed.
The synthetic leather obtained by the release sheets of Comparative Examples 1 and 2 may have the above-described visual recognition result because the S _(80-20) value is not within a desired range (4 ° or more and 15 ° or less). It was suggested.

Moreover, the synthetic leather obtained using the release sheet of Examples 7 and 8 among the synthetic leathers obtained using the release sheets of Examples 1 to 10 has a high gloss feeling from the results of the appearance evaluation. However, it was felt that there was a feeling of shine than other examples. The synthetic leather obtained from the release sheets of Examples 1 to 6 and Examples 9 to 10 has a diffusion angle within a desired range (greater than 5 ° and not more than 90 °), and thus the diffusion angle is within a desired range. Compared with the synthetic leather obtained by the release sheets of Examples 7 to 8 which are not present, it was suggested that a higher shine protection effect can be obtained.
Further, in Examples 4 to 6, Example 8 and Example 10, since the unit lens of the release sheet was convex with respect to the lens portion forming surface of the release layer, Examples 1 to 3 and Example Compared with 7 and Example 9, the amount of polyurethane used for the production of synthetic leather could be reduced.

DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Release layer 3 ... Lens part 3a ... Unit lens 10 ... Release sheet 11 ... Support layer 12 ... Resin skin layer 13 ... Lens shape part 13a ... Unit lens shape 20 ... Resin leather

Claims (5)

A lens part having a plurality of unit lenses having a curved surface on the surface, the radius of curvature of the unit lens is 15 μm or more and 150 μm or less;
Release sheet for resin leather production.   The release sheet according to claim 1, wherein a diffusion angle when light is incident on the lens unit from a vertical direction is greater than 5 ° and equal to or less than 90 °.   A resin leather having a lens shape portion having a plurality of unit lens shapes having a curved surface on the surface, and a radius of curvature of the unit lens shape being 15 μm or more and 150 μm or less.   The resin leather according to claim 3, wherein the resin leather has a lens shape portion having a plurality of unit lens shapes each having a curved surface on a surface, and a width of the unit lens shape is 30 μm or more and 300 μm or less.   The resin leather according to claim 3 or 4, wherein a diffusion angle when light is incident on the lens shape portion from a vertical direction is greater than 5 ° and not greater than 90 °.