Colored resin sheets and leather-like sheets

Abstract

This colored resin sheet contains a resin and a coloring agent dispersed in the resin, and has an average visible light transmittance of 50% or greater with respect to the red region where the wavelengths are 680-780 nm, and satisfies one of the following: the lightness L* value is 15 or smaller, and the average visible light transmittance is 15% or higher with respect to the full visible light region where the wavelengths are 380-780 nm; the lightness L* value is greater than 15 but not greater than 35, and the average visible light transmittance is 25% or higher with respect to the full visible light region; and the lightness L* value is larger than 35 but not greater than 60, and the average visible light transmittance is 40% or higher with respect to the full visible light region. The leather-like sheet includes a colored resin layer and has a surface with a lightness L* value of 40 or smaller, the leather-like sheet having an average visible light transmittance of 5% or higher with respect to the red region where the wavelengths are 680-780 nm.

Description

[Technical field]

[0001] The present invention relates to a colored resin sheet and a leather-like sheet having optical transparency. [Background technology]

[0002] In recent years, with the diversification of consumer tastes, there has been a demand for materials with novel designs to decorate the surfaces of articles. In light of this, a technology has been proposed in which a lighting device, such as a backlight or a liquid crystal panel equipped with a backlight, is placed on the back of a colored sheet to emit light and transmit it, thereby making letters, figures, etc. appear on the surface of the sheet.

[0003] For example, the following Patent Document 1 discloses synthetic leather having a visible light transmittance of 0.10 to 11.90% in the wavelength range of 380 to 780 nm, which is obtained by laminating a surface layer made of polyurethane resin on raw cloth. It also discloses that a black synthetic leather having a visible light transmittance of 0.17 to 0.20% in the wavelength range of 380 to 780 nm is obtained by laminating a surface layer colored black with a black pigment (manufactured by DIC Corporation, product name "Dialac L-1770") on a raw cloth that is a black knitted polyester. It also discloses that a white synthetic leather having a visible light transmittance of 10.87 to 11.90% in the wavelength range of 380 to 780 nm is obtained by laminating a surface layer colored white with a white pigment (manufactured by DIC Corporation, product name "Dialac L-1781") on a raw cloth that is a white knitted polyester.

[0004] In addition, the following Patent Document 2 discloses a light-transmitting artificial leather sheet using a transparent or translucent elastomer sheet, characterized in that the back or front of the elastomer sheet is provided with a smoke printed layer, the back of the elastomer sheet, and the outermost layer is provided with a mask printed layer for making letters, figures, patterns, or a design of a combination of these stand out, and the surface of the elastomer sheet is provided with unevenness of a leather pattern. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-177714 A [Patent Document 2] JP 2014-173203 A Summary of the Invention [Problem to be solved by the invention]

[0006] It has been difficult to maintain high light transmittance in a colored resin sheet that is colored in a deep color such as black. In addition, when the content of the coloring agent in the colored resin sheet is reduced in order to increase the light transmittance, the color intensity decreases. In addition, when the content of the coloring agent in the colored resin sheet is increased in order to increase the color intensity, the light transmittance decreases.

[0007] In this way, in a colored resin sheet colored in a dark color, if the light transmittance is increased, the darkness of the appearance decreases, and if the darkness of the appearance increases, the light transmittance tends to decrease. In this way, in a colored resin sheet colored in a dark color, there is a trade-off between the darkness of the color and the light transmittance.

[0008] Furthermore, when the colored resin sheet is of a medium or low dark color, the layer underneath covered by the colored resin sheet is not sufficiently concealed, which may reduce the design quality of the colored resin sheet or cause letters, figures, etc. that appear on the surface of the colored resin sheet to become unclear.

[0009] The present invention aims to obtain a colored resin sheet that has an excellent balance between colorability and light transmittance. It also aims to obtain a leather-like sheet that has a colored layer and has an excellent balance between light transmittance that makes transmitted light clear and the concealment of a fiber substrate. [Means for solving the problem]

[0010] One aspect of the present invention is a colored resin sheet comprising a resin and a colorant dispersed in the resin. The colorant contains a reactive special pigment in which a chromophore is bonded to a polyol, and the colored resin sheet is The average visible light transmittance in the red region of 680 to 780 nm is 50% or more, and the brightness L * The value is 15 or less, and the average light transmittance in the entire visible light region of 380 to 780 nm is 15% or more. * The value is more than 15 and 35 or less, and the average light transmittance in the entire visible light region is 25% or more, or the brightness L * The colored resin sheet satisfies either one of the following: the value is more than 35 and not more than 60, and the average light transmittance in the entire visible light region is 40% or more. Note that the average light transmittance is an arithmetic mean. In such a colored resin sheet, by transmitting a large amount of light in the red region of 680 to 780 nm wavelength, which does not easily lighten the emitted color, so that the average value is 50% or more, a colored resin sheet with an excellent balance between colorability and high light transmittance can be obtained.

[0011] In addition, it is preferable that the average dispersed particle diameter of the colorant is 400 nm or less, and further that the colorant is mixed with the resin at the molecular level, since this makes it easier to obtain a colored resin sheet that can maintain high light transmittance even when colored dark colors.

[0012] Also, the lightness L * It is preferable that the lightness L is 5 or more and 15 or less, and the average light transmittance in the entire visible light region is 15 to 26%, because this provides an excellent balance between deep color and light transmittance. * Deep-dark colors with a value below 5 tend to be too dark, making it difficult to balance darkness with light transmission.

[0013] Also, the lightness L * It is preferable that the value is more than 15 and 35 or less and the average light transmittance in the entire visible light region is 25 to 35%, in view of an excellent balance between moderately deep color and light transmittance.

[0014] Also, the lightness L *It is preferable that the lightness L is more than 35 and not more than 60, and the average light transmittance in the entire visible light region is 40 to 50%, in terms of an excellent balance between low deep color and light transmittance. * If the value exceeds 60, the color tends to be too bright and the balance between coloring and light transmittance tends to be poor.

[0015] Another aspect of the present invention is a leather-like sheet comprising a fiber substrate and a colored resin layer laminated on the fiber substrate. The colored resin layer is a layer of resin and a colorant dispersed in the resin. The colorant includes a reactive special pigment having a polyol bonded to a chromophore. The leather-like sheet has a lightness L on the surface of the colored resin layer. * The leather-like sheet has a surface with a lightness L of 60 or less. The leather-like sheet also has an average visible light transmittance in the red region of 680 to 780 nm in wavelength of 5% or more. Preferably, the average light transmittance in the entire visible light region of 380 to 780 nm in wavelength is 2% or more. In such a leather-like sheet, the colored resin layer exhibits excellent hiding power for the fiber substrate. Also, such a leather-like sheet has a lightness L * Even with a surface ranging from a dark color with a value of 40 or less to a low dark color, light transmission is still possible, allowing the light passing through to be clear.

[0016] In addition, the surface brightness L * It is preferable because it is easy to maintain light transmittance such that the average light transmittance in the entire visible light region of 380 to 780 nm is 2% or more even if the value is in the range of dark to medium dark colors of 25 or less. Such a leather-like sheet can be easily obtained by using a colored resin sheet as the colored resin layer that has an average visible light transmittance in the red region of 680 to 780 nm of 50% or more.

[0017] In particular, the surface of the leather-like sheet has a lightness of L * The value is 15 or less, and preferably the lightness L * The value is L *It is preferable that the value is 15 or less and 5 or more, and the average light transmittance of the leather-like sheet in the entire visible light region of wavelengths from 380 to 780 nm is 2% or more. In the case of such a leather-like sheet, it is preferable because it has a particularly excellent balance between light transmittance, which makes the transmitted light clear, and the hiding power of the fiber substrate in dark colors.

[0018] In addition, the surface of the leather-like sheet has a brightness of L * It is preferable that the value is more than 15 and 25 or less, and the average light transmittance of the leather-like sheet in the entire visible light region is 3% or more. In the case of such a leather-like sheet, in the range of medium to low dark colors, it is preferable because it has a particularly excellent balance between light transmittance, which makes the transmitted light clear, and the hiding power of the fiber substrate.

[0019] In addition, the surface of the leather-like sheet has a brightness of L * It is preferable that the value is more than 25 and not more than 40, and the average light transmittance of the leather-like sheet in the entire visible light region is 4% or more. In the case of such a leather-like sheet, it is preferable because it has a particularly excellent balance between light transmittance, which makes the transmitted light clear, and the hiding power of the fiber substrate in low dark colors.

[0020] In addition, the fiber base material preferably contains 10 to 50 mass % of the polymer elastomer in the voids thereof relative to the total mass of the fiber base material and has a void ratio of 70 volume % or less, from the viewpoint of excellent light transmittance.

[0021] In addition, the fiber base material is preferably a fiber structure made of white fibers, since this makes it easier to maintain high light transmittance such that the average light transmittance in the entire visible light region of wavelengths from 380 to 780 nm is 2% or more. Effect of the Invention

[0022] According to the present invention, it is possible to maintain high light transmittance in a colored resin sheet that has been colored. Also, in a leather-like sheet having a colored layer, it is possible to obtain a leather-like sheet that has an excellent balance between light transmittance that makes transmitted light clear and the concealment property of the fiber substrate. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic cross-sectional view of a leather-like sheet 10 according to an embodiment. [Diagram 2] FIG. 2 shows spectra indicating the light transmittance in the visible light region of wavelengths of 380 to 780 nm of the colored resin sheets (colored resin layers) obtained in Example 5 and Comparative Example 6. As shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] An embodiment of the colored resin sheet and the leather-like sheet according to the present invention will be described in detail below.

[0025] The colored resin sheet of the present embodiment is a colored resin sheet in which a colorant is dispersed in a resin sheet. The colorant contains a reactive special pigment in which a chromophore is bonded to a polyol, and the colored resin sheet is The average visible light transmittance in the red region of 680 to 780 nm is 50% or more, and the brightness L * The value is 15 or less, and the average light transmittance in the entire visible light region of 380 to 780 nm is 15% or more. * The value is more than 15 and 35 or less, and the average transmittance of the entire visible light region is 25% or more, or the brightness L * The colored resin sheet satisfies either one of the following: the transmittance value is more than 35 and not more than 60, and the average light transmittance in the entire visible light region is 40% or more. In such a colored resin sheet, a large amount of light in the red region of 680 to 780 nm wavelength, which does not easily lighten the emitted color, is transmitted so that the average light transmittance in the entire visible light region is 50% or more, thereby making it possible to maintain a high average light transmittance in the entire visible light region.

[0026] Resins for forming the resin sheet are preferably transparent resins having an average light transmittance of 60% or more, and more preferably 70% or more in the entire visible light region of 380 to 780 nm. Examples of such transparent resins include hard transparent resins including polycarbonate-based resins and transparent polymeric elastomers including polyurethane-based elastomers, acrylic-based elastomers, polyamide-based elastomers, polyester-based elastomers, polystyrene-based elastomers, and polyolefin-based elastomers. Transparent polymeric elastomers are particularly preferred because they can maintain a leather-like soft texture when the colored resin sheet is used as a colored resin layer that is the surface layer of the leather-like sheet described below.

[0027] In addition, the color pigment dispersed in the resin sheet is , including reactive special pigments with polyols bonded to the chromophore, 6 Pigments and dyes that increase the transmittance of visible light in the range of 80 to 780 nm. A reactive special pigment with a polyol bonded to the chromophore. Examples include Milliken's Vivitint and Reactint. , etc. Disperse type perylene black; organic pigments such as Pigment Yellow 73 and Pigment Red 5; polymerizable dyes with reactive polymerizable groups; disperse dyes; basic dyes, etc. etc. Of these, Vivitint and Reactint are particularly preferred.

[0028] The average dispersed particle diameter of the colorant is preferably 400 nm or less, more preferably 300 nm or less, and is particularly preferably mixed into the colored resin sheet at a molecular level so that the particle contour shape cannot be clearly identified. If the average dispersed particle diameter of the colorant is too large, the colorant particles tend to scatter or reflect light with long wavelengths, making it difficult to maintain the average visible light transmittance in the red region of 680 to 780 nm in wavelength at 50% or more, as described below.

[0029] The colored resin sheet has an average visible light transmittance in the red region of 680 to 780 nm of 50% or more, preferably 55 to 65%. By having the colored resin sheet have an average visible light transmittance in the red region of 680 to 780 nm of 50% or more, the average light transmittance in the entire visible light region can be increased without significantly lightening the emitted color.

[0030] The colored resin sheet as described above has a lightness L * Dark colors such as black with a value of 15 or less and lightness L * Medium dark colors with a value of more than 15 and less than 35, and lightness L * It is darkly colored with a low color value of more than 35 and less than 60.

[0031] Lightness L * Dark colors with a value of 15 or less, preferably lightness L * In the case of a deep color having a value of 5 or more and 15 or less, the average light transmittance in the entire visible light region of 380 to 780 nm is 15% or more, preferably 15 to 26%. For example, the colored resin sheet obtained in Example 5 below, which contains 15% by mass of VIVITINT BLACK 856 shown in FIG. 2, has a lightness L * The colored resin sheet is a dark black color with a brightness L of 5.7 and an average light transmittance of 16.6% in the visible light region of 380 to 780 nm. On the other hand, the colored resin sheet obtained in Comparative Example 6, which is described later and contains 3.0% by mass of carbon black shown in FIG. 2, has a brightness L * The resin sheet has a deep dark color and an average light transmittance of 1.1% in the visible light region having a wavelength of 380 to 780 nm.

[0032] Also, the lightness L * In the case of a medium dark color with a value of more than 15 and not more than 35, the average light transmittance in the entire visible light region of wavelengths from 380 to 780 nm is 25% or more, preferably 25 to 35%, and more preferably 30 to 35%. For example, the colored resin sheet obtained in Example 2 described below, which contains 5% by mass of VIVITINT BLACK 856, has a lightness L *The colored resin sheet has a lightness L of 28.1 and an average light transmittance in the visible light region of 380 to 780 nm is 32.7%. For example, the colored resin sheet obtained in Example 6, which is described later and contains 5% by mass of dispersion-type perylene black, has a lightness L of 28.1 and an average light transmittance in the visible light region of 380 to 780 nm is 32.7%. * The colored resin sheet has a medium dark color with an average light transmittance of 25.2% in the visible light region of 380 to 780 nm and a transmittance of 23.7.

[0033] In addition, the brightness L * In the case of a low, deep color having a lightness value of more than 35 and not more than 60, the average light transmittance in the entire visible light region of 380 to 780 nm is 40% or more, preferably 40 to 50%, and more preferably 45 to 50%. For example, the colored resin sheet obtained in Example 1 described below, which contains 2.5% by mass of VIVITINT BLACK 856, has a lightness L * The colored resin sheet has a low, deep color with an average light transmittance of 45.8% in the visible light region having a wavelength of 380 to 780 nm.

[0034] The thickness of the colored resin sheet and the content of the coloring agent are adjusted so that the average light transmittance of the entire visible light region of wavelengths from 380 to 780 nm falls within a predetermined range according to the brightness of the surface of the intended colored resin sheet. An example of the thickness of the colored resin sheet and the content of the coloring agent is a combination of a thickness of 30 to 90 μm and a content of the coloring agent of 1 to 20 mass %.

[0035] The colored resin sheet may have a single layer structure made of a resin composition having a uniform blend composition, or may have a laminate structure made of resin compositions having mutually different blend compositions.

[0036] The leather-like sheet of this embodiment is a leather-like sheet comprising a fiber substrate and a colored resin layer laminated on the fiber substrate. The colored resin layer comprises a resin having a coloring agent dispersed therein. The leather-like sheet has a surface brightness L *The value is 40 or less. The leather-like sheet has an average visible light transmittance in the red region of 680 to 780 nm wavelengths of 5% or more.

[0037] Examples of the fiber substrate include nonwoven fabric, woven fabric, knitted fabric, and combinations thereof. Among these, nonwoven fabric, particularly nonwoven fabric of ultrafine fibers having a fineness of 1 dtex or less, is particularly preferred because it provides a flexible leather-like sheet. In this embodiment, the case where the fiber substrate is a nonwoven fabric will be described in detail as a representative example.

[0038] As the resin forming the fiber forming the fiber base material, a thermoplastic resin having optical transparency is preferably used. Specific examples of such thermoplastic resins include polyester resins such as polyethylene terephthalate (PET) or modified polyester resins such as modified PET obtained by copolymerizing a small amount of monomer units with these; polyamide resins such as polyamide 66; various acrylic resins; and thermoplastic resins having fiber forming ability such as olefin resins such as polyethylene and polypropylene. These may be used alone or in combination of two or more.

[0039] The fiber form such as the fineness, cross-sectional shape, and fiber length of the fiber forming the fiber substrate is appropriately selected. Examples of the fineness of the fiber include fibers with normal fineness and ultrafine fibers with a fineness of 1 dtex or less. Among these, nonwoven fabrics made of ultrafine fibers with a fineness of 0.8 dtex or less are preferable because they are excellent in flexibility and can improve light transmittance by densifying the nonwoven fabric to reduce the porosity. The fineness is calculated by taking a scanning electron microscope (SEM) photograph of the cross section of the leather-like sheet at 3000 times, randomly selecting 10 fiber cross sections, measuring the cross-sectional area, calculating the average value of the cross-sectional areas, and converting it from the density of each resin.

[0040] The resin used in the manufacture of the fiber substrate may be blended with various additives, specifically, for example, color inhibitors, heat resistance agents, flame retardants, lubricants, antifouling agents, fluorescent brighteners, matting agents, gloss improvers, antistatic agents, fragrances, deodorants, catalysts, antibacterial agents, anti-mite agents, inorganic fine particles, etc., as necessary, within the scope of the purpose and effect of the present invention. The resin used in the manufacture of the nonwoven fabric is preferably a colorless fiber or a white fiber that does not substantially contain a colorant that colors the fiber, since it is easy to obtain a leather-like sheet with high light transmittance. The white fiber means a raw yarn in which colorants such as coloring pigments and dyes are not mixed into the raw material before spinning.

[0041] In addition, the fiber substrate preferably contains a polymeric elastomer, preferably a light-transmitting, uncolored polymeric elastomer, in its internal voids. Specific examples of such polymeric elastomers include polyurethane-based elastomers, acrylic-based elastomers, polyamide-based elastomers, polyester-based elastomers, polystyrene-based elastomers, and polyolefin-based elastomers. Among these, polyurethane-based elastomers and acrylic-based elastomers are preferred, and in particular, the combination of polyurethane-based elastomers and acrylic-based elastomers is preferred because of their excellent balance between light transmittance and mechanical properties. In addition, the polymeric elastomer is preferably a non-foamed material in order to maintain high light transmittance.

[0042] When the fiber base material is an entangled nonwoven fabric of ultrafine fibers consisting of island components obtained by removing the sea component from an entangled sheet of islands-in-sea type composite fibers, it is preferable to impart a polymer elastomer to voids in the fiber bundles formed by removing the sea component, since the interface between the ultrafine fibers and air is replaced by the interface between the ultrafine fibers and the polymer elastomer, thereby reducing the refractive index difference and further improving light transmittance.

[0043] When the fibrous substrate contains a polymeric elastomer, the content of the polymeric elastomer in the fibrous substrate is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass.

[0044] Furthermore, when the fiber substrate contains a polymer elastomer, the porosity in the fiber substrate is 70 volume % or less, preferably 60 volume % or less, particularly 50 volume % or less, and preferably 30 volume % or more, in order to exhibit high translucency.

[0045] The thickness of the fiber substrate is preferably 0.1 to 1.0 mm, more preferably 0.2 to 0.6 mm, since it is easy to obtain a leather-like sheet that retains high light transmittance.

[0046] Referring to FIG. 1, one surface of a fiber base material 1 forming a leather-like sheet 10 is covered with an intermediate layer 2, and a colored resin sheet is covered on the intermediate layer 2 as a colored resin layer 3.

[0047] The leather-like sheet 10 is formed by forming a colored resin sheet on a supporting substrate such as release paper, forming an intermediate layer having adhesive properties on the surface of the colored resin sheet, attaching the intermediate layer to one side of the fiber substrate 1, pressing to adhere if necessary, and peeling off the release paper.

[0048] The thickness of the intermediate layer is not particularly limited, but is preferably, for example, 10 to 300 μm.

[0049] The intermediate layer is a single or multi-layer elastic layer formed to ensure a sufficient thickness for imparting elasticity to the leather-like sheet and to adhere the colored resin sheet to the fiber substrate. Examples of the polymeric elastomer for forming the intermediate layer include polyurethane-based elastomers, acrylic-based elastomers, polyamide-based elastomers, polyester-based elastomers, polystyrene-based elastomers, polyolefin-based elastomers, etc., which have been used conventionally in the manufacture of resin layers that form the surfaces of leather-like sheets.

[0050] The thickness of the leather-like sheet of this embodiment thus obtained is not particularly limited, but is preferably, for example, 0.02 to 10 mm, and more preferably about 0.05 to 5 mm, in order to maintain sufficient light transmittance.

[0051] The apparent density of the leather-like sheet is 0.03 to 1.5 g / cm3 , and even 0.06 to 1.2 g / cm 3 It is preferable that the leather-like sheet is dense in this way, since the reinforcing effect is enhanced.

[0052] The leather-like sheet of the present embodiment has a colored resin layer, and the colored resin layer includes, for example, a colored resin sheet as described above. * The surface has a value of 40 or less, and the average visible light transmittance in the red region of wavelengths from 680 to 780 nm is 5% or more.

[0053] In addition, the leather-like sheet of this embodiment preferably has an average light transmittance of 2% or more, more preferably 2-20%, and even more preferably 2-10% in the entire visible light region of 380-780 nm. If the average light transmittance in the visible light region of 380-780 nm is less than 2%, the light transmittance is low, and it tends to be difficult to clearly display characters or figures by light on the surface of the colored resin layer. If the average light transmittance in the visible light region of 380-780 nm is too high, the surface brightness L * It becomes difficult to obtain a leather-like sheet having a value of 40 or less.

[0054] The surface of the leather-like sheet, L * a * b * Lightness L in color system * It is preferred that the value be 40 or less, preferably 25 or less.

[0055] In addition, the leather-like sheet of this embodiment has an average light transmittance in the red region of 680 to 780 nm wavelengths of 5% or more, and preferably 7 to 15%. By having the leather-like sheet have an average light transmittance in the red region of 680 to 780 nm wavelengths of 5% or more, a large amount of light in the red region, which is difficult to dilute the luminous color, is transmitted, and the surface brightness L * Even if the value is 15 or less, it is easy to maintain light transmittance such that the average light transmittance in the visible light region of wavelengths from 380 to 780 nm is, for example, 2% or more.

[0056] According to the leather-like sheet of this embodiment, the lightness L * Value is 15 or less, preferably lightness L * If the value is between 5 and 15, the average light transmittance in the entire visible light range of 380 to 780 nm is 2% or more, and the brightness L * If the value is more than 15 and less than or equal to 25, the average light transmittance in the entire visible light region is 3% or more, or the brightness L * When the value is more than 25 and not more than 40, a leather-like sheet having excellent colorability and light transmittance, such as an average light transmittance of 4% or more in the entire visible light region, can be obtained.

[0057] The leather-like sheet described above is preferably used as a skin material for a light-emitting structure in which, for example, a light-emitting device such as a backlight or a liquid crystal panel equipped with a backlight is placed on the rear surface to emit light and transmit the light, thereby making letters, figures, etc. appear on the surface of the leather-like sheet. EXAMPLES

[0058] The present invention will be described in more detail below with reference to examples, although the scope of the present invention is not limited to these examples in any way.

[0059] First, the evaluation methods used in the present examples will be summarized below.

[0060] (Lightness L * value) The chromaticity of the surface of the colored resin sheet or the surface of the colored resin layer of the leather-like sheet was measured using a spectrophotometer (CM-3610d, manufactured by Konica Minolta, D65 light source). Specifically, a standard white plate (aluminum oxide plate) was placed on the opposite side of the surface of the colored resin sheet or leather-like sheet and set in the spectrophotometer, and the color was measured. The L * a * b * Lightness L in color system * The value was calculated.

[0061] (Measurement of light transmittance of colored resin sheet) A film of a colored resin sheet having a thickness of 60 μm was formed on a release paper. The obtained colored resin sheet was then peeled off from the release paper. The light transmittance of the film of the colored resin sheet in the wavelength region of 380 to 780 nm was measured using a spectrophotometer (Hitachi U-3010 Spectrophotometer). The arithmetic mean value of the light transmittance in the entire visible light region in the wavelength region of 380 to 780 nm and the arithmetic mean value of the light transmittance in the red region of 680 to 780 nm were then calculated. As an example, FIG. 2 shows the spectrum showing the light transmittance in the visible light region of wavelengths of 380 to 780 nm of the colored sheets obtained in Example 5 and Comparative Example 6.

[0062] (Measurement of light transmittance of leather-like sheet) The light transmittance of the leather-like sheet in the wavelength range of 380 to 780 nm was measured using a spectrophotometer (Hitachi U-3010 Spectrophotometer). The arithmetic mean value of the light transmittance in the entire visible light range of 380 to 780 nm and the arithmetic mean value of the light transmittance in the red range of 680 to 780 nm were calculated.

[0063] (Average dispersed particle size and dispersibility of colorant) The cross section of the colored resin sheet in the thickness direction was measured with a scanning electron microscope (SEM) at a magnification of 3000 times, and the average particle diameter of the colorant particles in a field of view of 10 μm square was identified. The average particle diameter was determined as the distance of the longest part of the particle. The particle diameters of each identified particle were then arithmetically averaged to obtain the average dispersed particle diameter. In addition, the case where the colorant dissolved and the outline could not be identified was judged as A, the case where the average particle diameter was 0.4 μm or less was B, and the case where particles with an average particle diameter of 0.4 μm or more were present was judged as C.

[0064] (Apparent density of leather-like sheet) According to JIS L 1913, thickness (mm) and basis weight (g / cm 2 ) and calculate the apparent density (g / cm 3 ) was calculated.

[0065] (Fineness of fibers forming the fiber substrate of leather-like sheet) The fineness was determined by taking a scanning electron microscope (SEM) photograph of the thickness direction cross section of the leather-like sheet at 3000x magnification, randomly selecting 10 fiber cross sections, measuring the cross-sectional area, calculating the average cross-sectional area, and converting it into the density of each resin.

[0066] (Porosity of fiber substrate of leather-like sheet) A scanning electron microscope (SEM) photograph of a cross section of the thickness direction of the leather-like sheet was taken at 300x magnification, and the true thickness direction was measured. The porosity of the fiber substrate was calculated using the following formula from the basis weight of the fiber substrate and the density of the raw materials used in the substrate. -Volus ratio of fiber base material (volume%) = (1-(weight per unit area / raw material density) / (thickness / true thickness)) x 100

[0067] (Concealment of fiber-based materials) A colored resin sheet was placed on top of a white or black fiber substrate, and the degree of transparency was visually evaluated when viewed from directly above. When the fiber substrate was completely invisible, it was rated as A, when the fiber substrate was only slightly visible, and when the fiber substrate was clearly visible, it was rated as C.

[0068] (Clarity of transmitted light) When the leather-like sheet was irradiated with a white LED light (150 lumens) from the side without the colored resin layer, the clarity of the color of the transmitted light was visually evaluated. If the transmitted light was bright white without any yellowish tint, it was rated as A, if it was white with a slight yellowish tint, it was rated as B, and if it was white with a strong yellowish tint and a slightly dull impression, it was rated as C.

[0069] [Example 1] A resin liquid for forming a colored resin sheet was prepared by dispersing a black pigment (VIVITINT BLACK856, manufactured by Milliken) in a 30% by mass polyurethane DMF solution containing non-yellowing polycarbonate-based polyurethane. The resin liquid contained 2.5% by mass of black pigment relative to the solid content of non-yellowing polycarbonate-based polyurethane. The prepared resin liquid was applied onto a release paper and then dried at 120°C for 2 minutes to form a black colored resin sheet with a thickness of 60 μm. The obtained colored resin sheet was then peeled off from the release sheet. The properties were evaluated by the above-mentioned method. The results are shown in Table 1 below.

[0070] [Table 1]

[0071] [Examples 2 to 5] A colored resin sheet was produced and evaluated in the same manner as in Example 1, except that the blending ratio of the colorant in the colored resin sheet was changed as shown in Table 1. The results are shown in Table 1.

[0072] [Example 6 (Reference example)] A colored resin sheet was produced and evaluated in the same manner as in Example 2, except that VIVITINT BLACK 856 was changed to a dispersion type perylene black. The results are shown in Table 1.

[0073] [Comparative Example 1] A resin liquid for forming a colored resin sheet was prepared by dispersing a black pigment (carbon black, Dilac L-1770, manufactured by DIC Corporation) in a 30% by mass polyurethane DMF solution containing non-yellowing polycarbonate-based polyurethane. The resin liquid contained 0.5% by mass of carbon black relative to the solid content of the non-yellowing polycarbonate-based polyurethane. A colored resin sheet having a thickness of 60 μm was formed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0074] [Comparative Examples 2 to 6] A colored resin sheet was produced and evaluated in the same manner as in Comparative Example 1, except that the blending ratio of the colorant in the colored resin sheet was changed as shown in Table 1. The results are shown in Table 1.

[0075] Referring to Table 1, the colored resin sheet obtained in Example 1, in which the average visible light transmittance in the red region is 69.4%, is L * The colored resin sheet obtained in Comparative Example 1, which has a low visible light transmittance of 52.3, and the average visible light transmittance in the red region of the colored resin sheet obtained in Comparative Example 1 is 43.6%, is also L * The colored resin sheet obtained in Example 1 had a low L value of 57.7, which was a dark color. * Despite the lower values ​​and deeper dark colors, the average light transmittance in the entire visible light range was high. * The colored resin sheets obtained in Examples 2 and 6, which had a medium dark color with L values ​​of 28.1 and 23.7, respectively, also had * Although the color is deeper and darker than the colored resin sheets obtained in Comparative Examples 2 and 3, which have a medium dark color with values ​​of 45.6 and 41.4, respectively, the average light transmittance in the entire visible light region was higher or equal to that of the colored resin sheets obtained in Comparative Examples 2 and 3. * The colored resin sheets obtained in Examples 4 and 5, which are deep dark colors having L values ​​of 7.9 and 5.7, respectively, also had * Although the color was deeper and darker than the colored resin sheets obtained in Comparative Examples 4 and 5, which had a medium dark color with values ​​of 26.8 and 22.0, the average light transmittance in the entire visible light region was higher or equivalent.

[0076] In addition, L using dispersion type perylene black * The colored resin sheet obtained in Example 6, which has a medium dark color and a L value of 23.7, also has * The average light transmittance in the entire visible light region was higher than that of the colored resin sheet obtained in Comparative Example 5, which had a medium dark color with a transmittance of 22.0.

[0077] Furthermore, in the colored resin sheets obtained in Examples 1 to 5, no aggregation of the colorant was observed, and the colorant was mixed at the molecular level.

[0078] [Example 7] A melt conjugate spinning die was used in which a water-soluble thermoplastic polyvinyl alcohol resin was used as a sea component, PET modified with 6 mol% isophthalic acid was used as an island component, the number of islands per fiber was 25, and the sea component / island component ratio was 25 / 75 (mass ratio). Island-in-sea type filaments were extruded from the die at 260°C. The ejector pressure was adjusted so that the spinning speed was 3700 m / min, and islands-in-sea type conjugate long fibers with an average fineness of 2.1 dtex were collected on a net. The islands-in-sea type conjugate long fibers collected on the net were lightly pressed with a metal roll with a surface temperature of 42°C to suppress surface fuzzing and were peeled off from the net, and further passed between a lattice-patterned metal roll and a back roll with a surface temperature of 75°C for hot pressing, resulting in a surface with a basis weight of 31 g / m2 where the ultrafine fibers were temporarily fused. 2 Thus, a long fiber web of 1000 g was obtained.

[0079] The obtained long fiber web was then cross-wrapped to pile up 8 sheets, which were then sprayed with a needle breakage prevention oil. Then, using a 6-barb needle with a distance from the needle tip to the barb of 3.2 mm, the needle depth was 8.3 mm, and 3300 punches / cm were applied alternately from both sides. 2 By needle punching at a punch density of 320g / m 2 Thus, an entangled filamentary web of 1000 g was obtained.

[0080] The long fiber web was then taken up and immersed in hot water at 70° C. for 14 seconds at a line speed of 10 m / min to cause thermal shrinkage, thereby obtaining a densified entangled web.

[0081] Next, the densified entangled web was impregnated with polyurethane as follows. The densified entangled web was impregnated with a polyurethane emulsion (solid concentration 30%) mainly composed of polycarbonate / ether-based polyurethane. The web was then dried in a drying oven at 150°C. The polyurethane-impregnated entangled web thus obtained was repeatedly subjected to dip-nip treatment in hot water at 95°C to dissolve and remove the modified PVA, thereby obtaining a nonwoven fabric of ultrafine fibers in which fiber bundles containing 25 ultrafine long fibers with an average fineness of 0.1 dtex were three-dimensionally entangled. The nonwoven fabric was then sliced ​​and buffed to obtain an apparent density of 0.50 g / cm. 3 The result was a nonwoven fabric substrate of ultrafine fibers with a thickness of 0.35 mm.

[0082] The nonwoven fabric substrate was then impregnated with an acrylic elastomer emulsion (RYUDYE-W BINDER 11KS-EN manufactured by DIC Corporation, resin content 30% by mass) at a pickup rate of 100%. The substrate was then dried in a dryer at 100°C for 10 minutes to obtain a fibrous substrate. The ratio of active ingredients in the fibrous substrate calculated from the pickup rate was ultrafine fiber / polyurethane / acrylic elastomer = 90 / 10 / 20 (mass ratio). The porosity of the fibrous substrate was 44%.

[0083] Then, a colored resin layer was laminated on the fiber substrate by a dry surface forming method as described below.

[0084] In the same manner as in Example 1, a resin liquid for forming a colored resin layer was prepared by dispersing a black pigment (VIVITINT BLACK856, manufactured by Milliken) in a 30% by mass polyurethane DMF solution containing a non-yellowing polycarbonate-based polyurethane. The prepared resin liquid was then applied onto a release paper and dried at 120°C for 2 minutes to form a colored resin sheet having a thickness of 60 μm.

[0085] Next, a resin liquid for forming an adhesive layer was applied to the surface of the colored resin sheet formed on the release paper, and then dried for 2 minutes at 120° C. to form an adhesive layer having a thickness of 50 μm. The resin liquid for forming the adhesive layer was a 30 mass % DMF solution of polycarbonate-based polyurethane.

[0086] The adhesive layer on the release paper thus formed was placed in contact with one side of the fiber substrate and pressed with a heated roll set at a surface temperature of 75° C. After aging for 3 days at 50° C., the release paper was peeled off to obtain a leather-like sheet with a black colored resin layer. The leather-like sheet thus obtained had a thickness of 0.31 mm and an apparent density of 1.07 g / cm. 3 , basis weight 333g / m 2 The properties were evaluated by the methods described above, and the results are shown in Table 2.

[0087] [Table 2]

[0088] [Examples 8 to 11] In the same manner as in Examples 2 to 5, leather-like sheets were produced and evaluated in the same manner as in Example 1, except that the blending ratio of the colorant in the colored resin sheet was changed as shown in Table 2. The results are shown in Table 2 below.

[0089] [Examples 12 to 14] Except for changing the fiber substrate from PET nonwoven fabric to PET knitted fabric, leather-like sheets were produced and evaluated in the same manner as in Example 8, Example 10, or Example 14. The results are shown in Table 2.

[0090] [Comparative Examples 7 to 11] A leather-like sheet was produced and evaluated in the same manner as in Example 7, except that the blending ratio of the colorant in the colored resin layer was changed as shown in Table 2. The results are shown in Table 2.

[0091] [Comparative Examples 12 to 14] Except for changing the fiber substrate from PET nonwoven fabric to PET knitted fabric, leather-like sheets were produced and evaluated in the same manner as in Comparative Examples 6 and 8. The results are shown in Table 2.

[0092] [Comparative Example 15] In the production of the long fiber web of Example 7, 0.5% by mass of carbon black was blended with PET with a degree of modification with isophthalic acid of 6 mol% to color the fibers black to produce a fiber substrate. A leather-like sheet was produced and evaluated in the same manner as in Comparative Example 9 except for the above. The results are shown in Table 2.

[0093] [Comparative Example 16] A colored resin sheet was produced and evaluated in the same manner as in Example 10, except that the porosity of the fiber base material was changed to 72 volume %. The results are shown in Table 2.

[0094] Referring to Table 2, the average visible light transmittance in the red region is 50% or more, and the surface brightness L * The leather-like sheets obtained in Examples 7 to 14, which had a colored resin layer with a colorant dispersed therein, had a total visible light transmittance of 60 or less, and the average light transmittance in the total visible light region of 380 to 780 nm was 2% or more. For example, * The total visible light transmittance of the leather-like sheet obtained in Example 8, which has a L value of 20.4, is 4.7. * The total visible light transmittance of the leather-like sheet obtained in Comparative Example 10 was 2.0, which was the same as that of the leather-like sheet obtained in Comparative Example 10, which had a value of 20.8. It can be seen that similar results were obtained when comparing the other Examples and Comparative Examples. [Explanation of symbols]

[0095] 1. Fiber base material 2 Adhesive layer 3 Colored resin layer 10. Leather-like sheet

Claims

1. A colored resin sheet comprising a resin and a colorant dispersed in the resin, The colorant includes a reactive special pigment having a polyol bonded to a chromophore, The colored resin sheet is The average visible light transmittance in the red region of the wavelength range of 680 to 780 nm is 50% or more, Lightness L ＊ The value is 15 or less, and the average light transmittance in the entire visible light region of 380 to 780 nm is 15% or more; Lightness L ＊ The value is more than 15 and 35 or less, and the average light transmittance in the entire visible light region is 25% or more, or Lightness L ＊ A colored resin sheet, characterized in that the value is greater than 35 and not greater than 60, and the average light transmittance in the entire visible light region is 40% or more.

2. 2. The colored resin sheet according to claim 1, wherein the average dispersed particle diameter of said colorant is 400 nm or less.

3. 3. The colored resin sheet according to claim 1, wherein said colorant is mixed with said resin at a molecular level.

4. The lightness L ＊ The colored resin sheet according to any one of claims 1 to 3, wherein the value is 5 or more and 15 or less, and the average light transmittance in the entire visible light region is 15 to 26%.

5. The lightness L ＊ The colored resin sheet according to any one of claims 1 to 3, wherein the value is more than 15 and not more than 35, and the average light transmittance in the entire visible light region is 25 to 35%.

6. The lightness L ＊ The colored resin sheet according to any one of claims 1 to 3, wherein the value is greater than 35 and less than 60, and the average light transmittance in the entire visible light region is 40 to 50%.

7. A leather-like sheet comprising a fiber substrate and a colored resin layer laminated on the fiber substrate, The colored resin layer includes a resin and a colorant dispersed in the resin, the colorant including a reactive special pigment having a chromophore bonded to a polyol, The leather-like sheet has a lightness of L ＊ having a surface with a value of 40 or less, The leather-like sheet has an average visible light transmittance in the red region of 680 to 780 nm wavelength of 5% or more.

8. 8. The leather-like sheet according to claim 7, wherein the average light transmittance over the entire visible light region of 380 to 780 nm is 2% or more.

9. The leather-like sheet has a lightness of L ＊ 9. The leather-like sheet according to claim 8, wherein said surface has a value of 5 or more and 15 or less.

10. The leather-like sheet has a lightness of L ＊ The leather-like sheet according to claim 7, having a surface with a value of more than 15 and not more than 25, and an average light transmittance in the entire visible light region of 380 to 780 nm is 3% or more.

11. The leather-like sheet has a lightness of L ＊ The leather-like sheet according to claim 7, having a surface with a value of more than 25 and not more than 40, and an average light transmittance in the entire visible light region of 380 to 780 nm is 4% or more.

12. The leather-like sheet according to any one of claims 7 to 11, wherein the colored resin layer comprises a colored resin sheet having an average visible light transmittance of 50% or more in the red region having a wavelength of 680 to 780 nm.

13. 13. The leather-like sheet according to claim 7, wherein the colorant has an average dispersed particle size of 400 nm or less.

14. The leather-like sheet according to any one of claims 7 to 13, wherein the voids in the fiber substrate contain 10 to 50 mass% of a polymer elastomer relative to the total of the voids in the fiber substrate, and the void ratio is 70 volume% or less.

15. The leather-like sheet according to any one of claims 7 to 14, wherein the fiber substrate is a fiber structure made of white fibers.

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