JP2023021526A - Release paper for diffractive gloss shaping - Google Patents

Abstract

To provide release paper that is homogeneous, has no uneven gloss, has a high sense of brightness, can be observed in a wide field of view, can be used for shaping a surface aspect exhibiting an excellent diffractive gloss on a material to be transferred, and is excellent in productivity.SOLUTION: Provided is release paper for shaping, by transfer, a surface aspect exhibiting a diffractive gloss on a target transfer material, wherein the release paper is a laminate having a base material layer and a shaping layer which is the outermost surface layer on one side. An outer surface of the shaping layer has a fine uneven structure, and exhibits a diffractive gloss in an MD direction and an MD-orthogonal direction of the release paper. The fine uneven structure is such that linear recesses and projections extending parallel to a substantial MD direction of the release paper are arranged alternately to form a substantially triangular cross section. The release paper has specific glossiness at an incident angle of 85 degrees and specific brightness at an incident angle of 45 degrees.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a release paper for imprinting a surface pattern exhibiting diffraction gloss on an object to be transferred by transfer.

For the purpose of improving the design of the surface of sheets such as synthetic leather and packaging, and the surfaces of decorative boards used for the surfaces of furniture, home interiors, and automobile interior materials, patterns are formed by unevenness, and diffraction is used. Gloss (for example, iridescent gloss) using a phenomenon may be imparted. In that case, there is a method of forming fine irregularities on the surface of the sheet to cause a diffraction phenomenon of light to develop a unique luster.

In order to develop a unique pattern, it is necessary to form a complicated uneven pattern with various depths and sizes, and as the pattern becomes more complicated, the manufacturing process becomes more complicated.
For example, a release paper having a hologram-like fine uneven shape on the surface has been proposed, and in a resin leather manufactured using such a release paper, the hologram-like fine uneven shape formed on the skin layer allows observation. Multicolor luster (rainbow luster) depending on the angle is exhibited (see Patent Documents 1, 2, and 3).
However, sufficient diffraction gloss is not obtained.

Japanese Patent No. 3098799 JP 2010-253779 A JP 2018-104844 A

In view of the above situation, the present invention is capable of imprinting on a transfer material a surface mode exhibiting excellent diffraction gloss that is homogeneous, has no gloss unevenness, has a high sense of brightness, and can be observed in a wide field of view, and improves productivity. An object of the present invention is to provide a release paper excellent in

The present inventors have made intensive studies to solve the above problems, and found that the release liner of the present invention having a specific fine uneven structure in the mold transfer layer can solve the above problems.
That is, the present invention is characterized by the following points.
1. A release paper for imprinting a surface aspect exhibiting diffraction gloss on a material to be transferred by transfer,
The release paper is a laminate having a substrate layer and a mold transfer layer that is the outermost layer on one side,
The outer surface of the imprinting layer has a fine uneven structure and exhibits diffraction gloss in the MD direction and the MD orthogonal direction of the release paper,
The fine concave-convex structure has linear recesses and protrusions that extend substantially parallel to the MD direction of the release paper and are alternately arranged to form a substantially triangular cross section,
In the glossiness measurement at an incident angle of 85 degrees in accordance with JIS Z 8741-1997 of the outer surface of the fine uneven structure,
The glossiness G1 _MD in the linear direction of the recesses and protrusions is 55 gloss or more and 98 gloss or less,
The glossiness G1 _TD in the direction orthogonal to the linear direction of the recesses and protrusions is 40 gloss or more and 80 gloss or less,
The average glossiness G1 _AVG of G1 _MD and G1 _TD is 50 gloss or more and 90 gloss or less,
The value of G1 _MD - G1 _TD is 8 gross or more and 45 gross or less,
In measuring the luminance of the outer surface of the mold layer in a direction perpendicular to the line direction of the recesses and protrusions in accordance with JIS Z 9117:2011, at an incident angle of 45 degrees,
The luminance C1 _TD is 700 cd/m ² or more and 1500 cd/m ² or less,
x1 value is 0.1 or more and 1.0 or less,
A release paper having a y1 value of 0.1 or more and 1.0 or less.
2. 2. The release paper according to 1 above, wherein the base material layer contains a paper base material.
3. 3. The release paper as described in 1 or 2 above, wherein the transfer layer contains a thermoplastic resin.
4. 4. An object to be transferred, which is produced from the release paper according to any one of 1 to 3 above and has a surface mode exhibiting diffraction gloss.

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a release paper that is homogeneous, has no gloss unevenness, has a high sense of brightness, can be observed in a wide field of view, and can form a surface state exhibiting excellent diffraction gloss on a transfer material. can.

1 is a bird's-eye view showing an example of a release paper of the present invention; FIG. 1 is a cross-sectional view showing an example of a release paper of the present invention; FIG. 1 is a plan view showing an example of a release paper of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of the apparatus for producing the material to be transferred of this invention. It is a schematic diagram showing an example of an apparatus for measuring the glossiness of the release paper of the present invention. It is a schematic diagram showing an example of an apparatus for measuring the luminance of the release liner of the present invention.

The present invention will be described below with reference to the drawings. However, the present invention is not limited to these specifically exemplified forms and various specifically described structures. Note that, in the drawings shown below, the sizes and ratios of members may be changed or exaggerated for easy understanding. In addition, for the sake of clarity, parts that are not necessary for explanation and symbols that are repeated may be omitted.
Further, in the present invention, the terms "sheet" and "film" are not distinguished by thickness, but are treated as having the same meaning.

<Release paper>
The release paper of the present invention imparts a diffractive gloss to the surface of a transfer material such as a sheet surface of a package or the like, or a decorative plate used for the surface of furniture, home interior materials, and automobile interior materials by transfer. Release paper for molding.
The release paper is like a printing plate in printing, and the surface mode previously formed on the release paper as a matrix can be transferred onto a material to be transferred. The surface pattern formed on the material to be transferred is the reverse of the surface pattern on the release paper.
The release paper of the present invention is a laminate having a substrate layer and an imprinting layer that is the outermost layer on one side, and the substrate layer and the imprinting layer may be bonded via an adhesive.
Further, the surface of the substrate layer may be subjected to adhesion-promoting treatment such as corona discharge treatment or ozone treatment, surface treatment such as primer coating, or the like, for the purpose of improving adhesion to the mold transfer layer.
The release paper may further have a functional layer made of various materials in order to adjust the moldability, bending resistance, rigidity, and the like.

The outer surface of the imprinting layer has a specific fine uneven structure for imprinting a surface mode exhibiting a diffractive gloss. can be transformed to transfer the fine uneven structure to form a surface mode exhibiting diffraction gloss.
Here, in order to form a surface state exhibiting excellent diffraction gloss on the surface of the material to be transferred, it is preferable that the outer surface itself of the pattern-imparting layer of the release paper also exhibits diffraction gloss.

The imprinting depth of the fine relief structure of the imprinting layer of the release paper can be measured by observing the imprinted cross-sectional shape with, for example, an SEM, and the shape pitch can be measured by measuring the surface shape with, for example, a laser microscope.
The evaluation index of the moldability of the release paper is the measurement of the mold depth and the shape pitch, for example, by the above means, or the JIS of the mold layer side outer surface of the release paper using a gloss meter (gloss meter), which is a handy device. Obtained by measuring the gloss value in accordance with Z 8741-1997 and measuring the luminance value, x value, and y value in accordance with JIS Z 9117:2011 of the external surface of the release paper on the transfer layer side using a color difference meter. can be done.
In addition, the brightness value, x value, and y value of the flat portion of the pattern transfer layer where there is no fine uneven structure can be similarly measured.
However, although the evaluation index calculated from the measurement results of the molding depth and the shape pitch is a more rigorous evaluation index, precise analysis by SEM is time-consuming and labor-intensive, so immediate evaluation can be easily performed at the manufacturing site. Measurements of gloss, brightness, x and y values are preferred.
The outer surface of the mold transfer layer of the release liner has a fine uneven structure, and the fine ridged structure is composed of linear recesses and protrusions extending substantially parallel to the MD direction of the release liner, which are alternately arranged, and have a substantially triangular shape. It preferably forms a cross section.

The fine concave-convex structure of the release paper layer is formed by transferring the fine concave-convex structure of the original plate such as an embossing roll. Accuracy, precision, and finish of the fine relief structure of the layer are affected, and deformation, chipping, and the like may occur.
And even if the design is the same fine uneven structure, the finished release paper does not show the same gloss, brightness, and shapeability, and the transferred material produced by transfer from the release paper does not have the same gloss. , Brightness, and shapeability may not be exhibited.
It is complicated and unrealistic to numerically control the shape and dimensions of the fine ruggedness structure itself in order to define the accuracy, precision, and finished state of the fine ruggedness structure of the mold transfer layer of the release paper in a specific good state. .
Therefore, in the present invention, it is preferable to specify the accuracy, precision, and finished state of the fine concavo-convex structure by setting specific regulations for the glossiness and brightness of the mold transfer layer of the release paper.
In addition, having a specific range of glossiness and brightness at the same time produces a synergistic effect, and a release paper having excellent diffraction gloss visibility, diffraction gloss uniformity, shaping properties, and release properties can be obtained. The release paper can be used to prepare a transferred material having excellent diffraction gloss visibility and diffraction gloss uniformity.

(Glossiness)
The outer surface of the mold transfer layer of the release paper preferably exhibits diffraction gloss in the MD direction and the direction orthogonal to the MD.
The glossiness of the release paper is measured, for example, as shown in FIG.
In the glossiness measurement in accordance with JIS Z 8741-1997 at an incident angle of 85 degrees on the outer surface of the fine uneven structure, the glossiness G1 _MD in the linear direction of the recesses and protrusions is 55 gloss or more and 98 gloss or less. is preferred, 60 to 95 gross is more preferred, and 63 to 93 gross is even more preferred.
The glossiness G1 _TD of the concave and convex portions in the direction orthogonal to the linear direction is preferably 40 gloss or more and 80 gloss or less, more preferably 45 gloss or more and 75 gloss or less, and still more preferably 48 gloss or more and 70 gloss or less.
The average glossiness G1 _AVG between G1 _MD and G1 _TD is preferably 50 gloss or more and 90 gloss or less, more preferably 53 gloss or more and 85 gloss or less, and still more preferably 55 gloss or more and 80 gloss or less.
The value of G1 _MD - G1 _TD is preferably 8 gross to 45 gross, more preferably 10 to 30 gross, and even more preferably 13 to 25 gross.
Here, the angle of incidence is 0 degree when the angle is perpendicular to the release paper. The observation angle (angle of reflection, angle of light reception) is the same as the angle of incidence, ±0.1 degrees.
If the values of G1 _MD , G1 _TD , G1 _AVG , G1 _MD −G1 _TD are within the above ranges, it means that the fine relief structure has few defects or deformation and is formed within the designed accuracy and precision. It exhibits excellent stencilability and can impart good diffraction luster (rainbow luster) to the surface of the material to be transferred.

In addition, when G1 _MD and/or G1 _TD is larger than the above range, even if there is no defect in the formation of the fine concave-convex structure, the surface of the material to be transferred becomes difficult to exhibit sufficient iridescent luster, and the iridescent luster becomes weak. Or, unevenness and variation tend to occur easily, and the quality tends to be difficult to stabilize.
If the gloss value of the surface of the mold transfer layer of the release paper satisfies the above, it is easy for the material to be transferred to exhibit sufficient iridescent gloss visibility.

In addition, in glossiness measurement in accordance with JIS Z 8741-1997 at an incident angle of 85 degrees of a flat portion not having the fine uneven structure on the outer surface of the mold layer, G1 in the same direction as _MD When the glossiness is G0 _MD , the glossiness in the same direction as _GTD is _G0TD , and the average glossiness of _G0MD and _G0TD is _G0AVG , the value of _G0AVG - _G1AVG is 5 gloss or more. , preferably 55 gloss or less, more preferably 7 gloss or more and 50 gloss or less, and still more preferably 10 gloss or more and 45 gloss or less.

The larger the value of G0 _AVG −G1 _AVG , the less missing or deformed the fine uneven structure, indicating that it is formed within the range of designed accuracy and precision, and exhibits excellent moldability. Good diffraction luster (rainbow luster) can be imparted to the surface of the transferred material.
If the value of G0 _AVG −G1 _AVG is smaller than the above range, it indicates that there are many defects and deformations in the fine uneven structure, the moldability is likely to be inferior, and good diffraction gloss (rainbow gloss) is obtained on the surface of the transferred material. It can be difficult to give.
It is practically difficult to make the value of G0 _AVG -G1 _AVG larger than the above range in terms of productivity and cost.
Here, the flat portion of the outer surface of the pattern-imparting layer that does not have the fine concave-convex structure may refer to an unshaped pattern-imparting layer of the original release liner.

In the above gloss measurement, the incident angle is preferably 85 degrees. By setting the incident angle to 85 degrees, it is possible to determine with higher accuracy and precision that the fine uneven structure is formed with less lack and deformation than when the incident angle is around 60 degrees. A distinction that was not possible when the angle is around 60 degrees becomes possible.

(Luminance)
The luminance C1 TD of the outer surface of the fine uneven structure was measured at an incident angle of 45 degrees perpendicular to the linear direction of the concave and convex portions and an observation angle of 45 degrees in accordance with JIS Z 9117: 2011. The luminance C1 _TD was 700 cd. /m ² or more and 1500 cd/m ² or less, more preferably 800 cd/m ² or more and 1300 cd/m ² or less, and even more preferably 850 cd/m ² or more and 1150 cd/m ² or less.
The x1 value is preferably 0.1 or more and 1.0 or less, more preferably 0.2 or more and 0.6 or less, and still more preferably 0.3 or more and 0.4 or less.
The y1 value is preferably 0.1 or more and 1.0 or less, more preferably 0.2 or more and 0.7 or less, and still more preferably 0.3 or more and 0.5 or less.
In addition, in the luminance measurement in accordance with JIS Z 9117:2011 at an incident angle of 45 degrees, the flat portion of the outer surface of the mold layer that does not have the fine uneven structure has the same direction as C1 _TD . When the glossiness is C0 _TD , the value of C1 _TD - CO _TD is preferably 200 cd/m ² or more and 800 cd/m ² or less, more preferably 250 cd/m ² or more and 700 cd/m ² or less, and 275 cd/m ² or more and 600 cd/m ² or less is more preferable.
Here, the flat portion of the outer surface of the pattern-imparting layer that does not have the fine concave-convex structure may refer to an unshaped pattern-imparting layer of the original release liner.

If the C1 _TD , x1 value, and y1 value are within the above ranges, it indicates that there are few defects and deformations in the fine uneven structure, and that it is formed within the designed accuracy and precision, and excellent moldability is achieved. It is possible to give good diffraction gloss (rainbow gloss) to the surface of the material to be transferred.

The brightness of the release paper is measured, for example, as shown in FIG.
In the above luminance measurement, the incident angle and reflection angle are preferably 45 degrees. By setting the incident angle and the reflection angle to 45 degrees, it is possible to determine that the fine uneven structure is formed with less missing and less deformation with higher accuracy and precision than in the case of other incident angles, A distinction that was not possible when the incident angle was around 60 degrees becomes possible.

[Base material layer]
In the present invention, the substrate layer is provided with moldability, flex resistance, rigidity, etc., and substrates made of conventionally known materials generally used for release paper and process paper can be used.
For example, one or a combination of two or more selected from the group consisting of various paper substrates, resin sheets, metal foils, woven fabrics, and non-woven fabrics can be used.

Examples of paper substrates include strong sizing bleached or unbleached paper substrates, pure white roll paper, kraft paper, paperboard, coated paper, cast-coated paper, processed base paper, high-quality paper, and lightly coated printing. Paper, coated printing paper, resin-coated paper, release base paper, double-sided coated release base paper, and the like can be used. Further, it may be a paper substrate on which an intermediate layer such as a sealing layer or a resin layer is formed in advance.
In the above, as the paper base material, a basis weight of about 40 g/m ² or more and 400 g/m ² or less, preferably a basis weight of about 100 g/m ² or more and 250 g/m ² or less can be used. desirable. If the basis weight is smaller than the above range, curling or waviness is likely to occur during the production of the transferred material. As a result, the winding diameter tends to increase and the working efficiency tends to decrease.

The thickness of the paper substrate is not particularly limited, but is preferably 25 μm or more and 200 μm or less, more preferably 50 μm or more and 150 μm or less. If the paper substrate is thicker than the above range, the cost increases, but the improvement in the supporting effect is limited. Further, if the thickness of the paper substrate is less than the above range, there is a risk of insufficient support during lamination and processing of the transfer layer.

As raw material pulp for the paper substrate, a mixture of softwood pulp (N material) and hardwood pulp (L material) is preferable. As a result, it is easy to obtain strength and smoothness that can withstand the process of manufacturing a release paper and the process of manufacturing a transferred material. Furthermore, the mixing ratio of hardwood pulp (L material) is preferably 50% to 90%. This further increases the smoothness.
In order for the release paper to have sufficient heat resistance, the paper substrate is preferably neutral paper, more preferably neutral paper sized using an alkylketene dimer as a sizing agent.

Examples of the resin for the resin film or resin sheet include polyester substrates such as polyethylene terephthalate and polyethylene naphthalate; polyamides such as various nylons;
It is preferable to use a paper base material from the viewpoint of resistance to heat deterioration and high adhesion to the transfer layer. When heat resistance and smoothness are particularly required, polyesters such as polyethylene terephthalate and polyethylene naphthalate are used. A substrate is preferably used.
If necessary, a paper base material and various resin films or resin sheets may be used in combination. Furthermore, when an ultraviolet curable resin is used for the mold layer and cured with ultraviolet rays, the substrate layer preferably transmits ultraviolet rays.

Although the thickness of the base layer is not particularly limited, it is preferably 25 μm or more and 200 μm or less, and more preferably 50 μm or more and 150 μm or less. If the substrate layer is thicker than the above range, the cost increases, but the improvement of the supporting effect is limited. If the thickness of the substrate layer is less than the above range, there is a risk of insufficient support during lamination and processing of the mold transfer layer.
The base layer of the completed release paper may have unevenness reflecting the fine unevenness structure of the mold transfer layer.

(smoothing layer)
In order to improve the smoothness and hardness of the surface of the base material layer, improve the formability of the fine concave-convex structure, and further improve the ability to transfer to the material to be transferred, the surface of the mold layer side is coated with clay. And/or a smoothing layer made of polyolefin resin can be provided.
When a material with a relatively rough surface such as kraft paper or fine paper is used as the paper substrate, it is easy to improve the smoothness on the paper substrate by providing a smoothing layer containing a polyolefin resin. .

Any clay that is generally called clay can be used without particular limitation. Clays that can be used include, for example, kaolin, talc, bentonite, smectite, vermiculite, mica, chlorite, Kibushi clay, gairome clay, halloysite, and mica. Among clays, talc has a low hardness (Mohs hardness of 1) and excellent heat resistance, so that it can improve heat resistance and dimensional stability during embossing.
The clay preferably contains calcium carbonate, titanium dioxide, amorphous silica, foaming barium sulfate, satin white, etc. as pigments. By using calcium carbonate or titanium dioxide as the pigment, the surface smoothness of the clay coat layer can be increased. Furthermore, calcium carbonate is inexpensive and is therefore preferably used.

A coating liquid for coating a smoothing layer containing clay contains the clay as a solvent, a binder, and, if necessary, other pigments and additives. As the solvent, water, alcohol and the like are usually used. As binders, latex binders (e.g., styrene-butadiene latex, acrylic latex, vinyl acetate-based latex), water-soluble binders (e.g., starch (modified starch, oxidized starch, hydroxyethyl etherified starch, phosphate ester starch), polyvinyl alcohol, casein, etc.) are used. As additives, a pigment dispersant, an antifoaming agent, an antifoaming agent, a viscosity modifier, a lubricant, a water resistance agent, a water retention agent, and the like are used.
The method of applying the clay-containing coating liquid is not particularly limited, but air knife coating, blade coating, short dwell coating, cast coating, and the like are used.

The thickness of the smoothing layer containing clay is not particularly limited, but the basis weight after drying is usually 5 g/m ² to 40 g/m ² , preferably 10 g/m ² to 40 g/m ² . If the basis weight after drying is smaller than the above range, the smoothness tends to be poor. Moreover, it is inferior in terms of cost performance.
The smoothing layer made of polyolefin resin may be formed by extrusion coating on the substrate layer.
Although the thickness of the smoothing layer is not particularly limited, it is preferably 10 μm to 60 μm.

(Anchor coat layer)
As for the substrate layer, if necessary, an anchor coat layer may be provided on the substrate layer or the smoothing layer to improve the adhesion between the imprinting layer and the smoothing layer or the substrate layer.
For example, when a smoothing layer containing clay is provided on the base material layer, the surface of the smoothing layer has good lubricity, so the adhesiveness to the imprinting layer tends to be poor, but the anchor coat layer is formed. By doing so, the adhesiveness can be enhanced.
The anchor coat layer can be formed, for example, by applying a water-soluble or water-dispersible emulsion or dispersion anchor coat agent.

Examples of anchor coating agents include polypropylene-based, modified polyolefin-based, ethylene-vinyl acetate copolymer-based, polyethyleneimine-based, polybutadiene-based, polyurethane-based, and polyester-based resin emulsions or dispersions, as well as polyvinyl chloride emulsions and urethane acrylic resins. Resin emulsion, silicone acrylic resin emulsion, vinyl acetate acrylic resin emulsion, acrylic resin emulsion, styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, methyl methacrylate-butadiene copolymer latex, chloroprene latex, polybutadiene latex rubber latexes such as polyacrylate latexes, polyvinylidene chloride latexes, or carboxyl-modified latexes of these latexes, and water-soluble anchor coating agents such as polyvinyl alcohol, water-soluble ethylene-vinyl acetate copolymers, polyethylene Aqueous solutions of oxides, water-soluble acrylic resins, water-soluble epoxy resins, water-soluble cellulose derivatives, water-soluble polyesters, water-soluble isocyanates, water-soluble lignin derivatives and the like can be used.

Among these, emulsions or dispersions of polypropylene-based or modified polyolefin-based resins are preferable because they can further strengthen the lamination strength of the polypropylene-based resin layer to paper and have excellent heat resistance.
The anchor coating agent can be applied by, for example, gravure coating, reverse roll coating, knife coating, kiss coating, or the like, and the coating amount is 0.1 g when dried. /m ² or more and 5 g/m ² or less, or 0.1 μm or more and 5 μm or less.

[Shaping layer]
In the present invention, the embossing layer is a layer made of a resin laminated on one side of the release paper, and has a fine concavo-convex structure for embossing a surface mode exhibiting diffraction gloss on the surface of the material to be transferred by transfer. It comprises a structural portion having
Here, by the transfer, a pattern in which the fine uneven structure of the pattern transfer layer is reversed is formed on the surface of the material to be transferred.
The resin contained in the imprinting layer is not particularly limited as long as it can function as the imprinting layer, and various thermoplastic resins, thermosetting resins, and ionizing radiation-curable resins such as ultraviolet rays and electron beams can be used. etc., or a combination of two or more thereof, but it is preferable to use a thermoplastic resin.

Thermoplastic resins include (meth)acrylic resins such as polyacrylate and polymethyl methacrylate; polyethylene resins, polypropylene resins, polymethylpentene resins, ethylene-propylene copolymers, and propylene-1-butene copolymers. , propylene-1-hexene copolymer, propylene-4-methyl-1-pentene copolymer, propylene-1-octene copolymer, propylene-1-decene copolymer, etc. polyolefin resin; melamine alkyd resin, polyethylene terephthalate polyester resins such as polybutylene terephthalate; vinyl resins such as polyvinyl chloride; styrene resins such as polystyrene; polycarbonate resins; The copolymer may be a random copolymer or a block copolymer. The softening point of the thermoplastic resin is preferably 90 to 135° C. in the case of polypropylene resin and 160 to 190° C. in the case of polymethylpentene resin, from the viewpoint of transferability by heat pressure.

Thermosetting resins include, for example, unsaturated polyesters; melamine-based resins such as melamine alkyd resins, methylolmelamine resins and methoxymethylolmelamine resins; epoxy resins; polyester (meth)acrylates, urethane (meth)acrylates, epoxy (meth)acrylates; (Meth)acrylic resins such as acrylates, polyether (meth)acrylates, polyol (meth)acrylates, melamine (meth)acrylates, and triazine acrylates; silicone resins;

Examples of ionizing radiation-curable resins such as ultraviolet rays or electron beams include urethane-based resins, epoxy-based resins, ester-based resins, (meth)acrylic-based resins, acrylic acid ester copolymers, and the like.
Polypropylene-based resins are preferred for general use, and polymethylpentene-based resins are preferred when the release paper is required to have heat resistance.
Moreover, when the formation precision of the fine unevenness|corrugation of a shaping|molding part is requested|required, an ultraviolet curable resin is preferable and a (meth)acrylic-type resin or an acrylic acid ester copolymer is preferable.

The mold transfer layer further contains an antioxidant, a weathering agent, a lubricant, an antistatic agent, an antifogging agent, a chlorine scavenger, a nucleating agent, an antiblocking agent, an organic/inorganic filler, a plasticizer, a stabilizer, and a coloring agent. 1 or 2 or more selected from etc. may be arbitrarily contained within a range that does not impair the object of the present invention.

The color of the transfer layer is not particularly limited, and a desired color such as red or black can be obtained using a coloring agent. Above all, when it is desired to reduce the reflectance in the entire wavelength range of visible light, it is preferable to color the resin layer black.
The coloring agent may be a pigment or a dye, and is not particularly limited. However, from the viewpoint of coloring the tip of the fine uneven structure, the pigment has a large particle size and may not penetrate to the tip of the fine uneven structure. It is preferable to use a dye that does not have such a possibility rather than to use .
The transfer layer is formed from a composition containing the raw materials described above, and the composition may or may not contain a solvent.
The mold layer may be composed of one layer, or may be composed of two or more layers of the same or different resin species.

In addition, the imprinting layer is integrally constituted by the imprinting portion, which is a thick portion having unevenness, and the base portion, which is a thick portion that supports the imprinting portion. There are no clear boundaries.
The thickness of the pattern transfer layer is not particularly limited, but is preferably 5 μm or more and 120 μm or less, more preferably 25 to 65 μm. If the thickness is less than the above range, the pressure at the time of forming the fine concave-convex structure becomes uneven when the roughness of the surface of the substrate layer is large, and the top surface height of the imprinting layer tends to have undulations. It becomes difficult for the object to be transferred (transfer product) to exhibit uniform iridescent visibility, and the design tends to be inferior.
If it is thicker than the above range, the release paper tends to curl, resulting in poor handleability.
Moreover, the thickness of the base is not particularly limited, but is preferably 100 μm or more and 200 μm or less. If the thickness of the base is thinner than the above range, the release paper tends to be easily damaged.
The thickness of the shaping portion may vary depending on the depth of the fine relief structure.

(Fine concave-convex structure)
The concave portions of the fine concave-convex structure of the imprinting layer according to the present invention have a shape capable of imprinting diffraction gloss on the surface of the material to be transferred.
For example, in FIG. 1, the shaping section has linear recesses extending in the y-axis direction. A plurality of linear concave portions are arranged in the x-axis direction. In addition, in FIG. 1 , the fine uneven structure has clear corners, but the corners may be rounded.

FIG. 2 is an enlarged view of part of FIG. P represents the pitch of the fine uneven structure, and D represents the depth of the fine uneven structure.
The cross section of the linear recess is substantially triangular, and the depth D is preferably 70 nm or more and 1500 nm or less, more preferably 450 nm or more and 1500 nm or less.
The pitch P is preferably 1600 nm or more and 2400 nm or less, more preferably 1800 nm or more and 2200 nm or less.
The apex angle of the triangle is preferably 70 degrees or more and 150 degrees or less, more preferably 80 degrees or more and 140 degrees or less.
Since the fine relief structure of the pattern transfer layer has the above-described shape and size, the transferred material has sufficiently bright diffraction gloss even when the corners of the uneven portions of the surface aspect are somewhat unclear. And it can be observed in a wide field of view.

Furthermore, as shown in FIG. 3, the linear concave portions of the fine concave-convex structure are linear concave portions extending in a direction of about 90 degrees to the patterning direction x of the release paper, but are 0 degrees to the direction y. It is preferable to have an inclination α of 1° or more and 1° or more.
Here, the imprinting direction (MD direction) is the direction in which the release paper is fed when the release paper is continuous paper, or when the release paper is sheet paper, the imprinting pressure is applied and the mold is released. pointing in the direction
In FIG. 3, by tilting the release paper at the above angle with respect to the y-axis direction, the releasability of the release paper at the time of transfer to the transfer material is improved, and the surface of the transfer material has a linear shape. Problems such as chipping in the uneven portion are less likely to occur.

The depth of the fine concave-convex structure of the release paper does not have to be the same as the depth of the fine concave-convex structure of the original plate, and can be adjusted by changing the transfer speed, pressure, temperature, and the like.
For example, it can be made shallower by increasing the transfer speed, lowering the pressure, or lowering the temperature.

(Method for making release paper)
As a method for producing the release paper, first, an original plate having a surface mode capable of imprinting the fine relief structure of the imprinting layer of the release paper is prepared.
The surface aspect of the original plate is such that a fine uneven structure can be formed on the release paper transfer layer by (thermal) pressure, and the fine uneven structure of the release paper transfer layer is substantially reversed. For example, the portion where the linear concave portion is formed in the release paper-transferring layer constitutes the linear convex portion. That is, it has a surface mode that is substantially the same as the diffraction structure layer of the material to be transferred.
The original plate may be made of any material such as metal, resin, or rubber, and may be in any shape such as roll, cylinder, plate, and sheet.

A first method for producing the release paper includes, for example, a method of transferring the surface mode of the master to a master having an unimprinted mold layer.
First, an imprinting layer is formed on a film for a base material layer by an extrusion coat lamination method to prepare a raw roll of release paper having an unimprinted imprinting layer and a base layer.
In addition, for example, by using a mirror-finished chill roll, the original fabric is passed between the mirror-finished roll and the press roll so that the imprint layer is in contact with the mirror-finished roll, thereby improving the smoothness of the surface of the imprint layer of the original fabric. may
Next, the surface of the imprinting layer of the original sheet and the surface having the surface aspect of the original plate are placed face to face, and (thermally) pressed to transfer the surface aspect of the original plate to the original sheet of the release paper. Examples include a method of transferring to a mold layer and peeling off to obtain a release paper. The raw material of the release paper may be a continuous sheet or a single sheet.

As a second method, for example, a composition for the release liner transfer layer is applied to the surface having the surface aspect of the original plate, and then a release liner substrate layer sheet is attached and released. , a method of obtaining a release paper.
The method of applying the composition is not particularly limited, and for example, die coating, extrusion coating, roll coating, reverse roll coating, micro bar coating, bar coating, knife coating, gravure coating and the like can be applied. The applied composition molds the surface aspect of the original plate, and the pattern transfer layer has a fine uneven structure.
After coating, the shape of the imprinting layer can be fixed by an appropriate curing method according to the composition, such as drying by heating, ionizing radiation such as ultraviolet rays or electron beams, or cooling.
An adhesive may be used for attaching the base material layer, if necessary.

<Original fabric of release paper>
The raw material of the release paper is the release paper in an unformed state.
It is advantageous and preferable for the surface of the mold transfer layer of the original roll of the release paper to have a high degree of smoothness because it facilitates the formation of the fine concave-convex structure accurately and with high precision.
However, the finished state of the fine uneven structure of the release paper is affected by the type of fine uneven structure and the process conditions for forming the mold. There are no particular restrictions on degree, glossiness, and brightness.
In addition, in order to obtain a raw roll of release paper with a highly smooth surface of the mold layer, for example, a smoothing layer is provided, or the raw roll is placed between a mirror-finished roll and a pressure roll so that the mold-transfer layer is in contact with the mirror-finished roll. An original roll of the release paper may be produced by passing it through the gap.
In addition, in order to obtain an original roll of release paper with a low smoothness of the surface of the imprinting layer, for example, the original sheet is placed on a mattill roll so that the imprinting layer is in contact with a mattill roll whose roll surface has been roughened by sandblasting. and a pressure roll to produce a release paper stock.

<Transferred material>
The material to be transferred is a transfer product obtained by transferring a fine concavo-convex structure from the release paper of the present invention to the surface of the raw material of the material to be transferred, and has a surface aspect exhibiting diffraction gloss.
The material to be transferred can have, for example, a diffraction structure layer having a surface mode exhibiting diffraction gloss and a substrate layer for supporting the diffraction structure layer. Appropriate materials may be used for each layer according to the application of the material to be transferred.

The diffraction structure layer of the transferred material can be formed from a composition containing various thermoplastic resins, thermosetting resins, ionizing radiation curable resins such as ultraviolet rays or electron beams, etc. The composition is solvent-free. or may be solvent-based.
The base material layer of the material to be transferred is provided as necessary. For example, when the diffraction structure layer has sufficient self-supporting properties, the base material layer need not be provided.
It is also possible to adhere the substrate layer to the non-diffractive glossy surface via an adhesive or the like after once producing a transfer material consisting of only the diffractive structure layer.

A material that supports the diffraction structure layer and has appropriate properties according to the application of the transfer material may be used for the base material layer of the transfer material. For example, natural fibers such as cotton, hemp, silk, wool, rayon,
Recycled or semi-synthetic fibers such as acetate, synthetic fibers such as polyester, polyacrylonitrile, polyvinyl alcohol, polyolefin, woven fabrics, non-woven fabrics, mesh fabrics (also called base fabrics) made of fibers such as glass fiber, paper, polyester It can be appropriately selected and used from materials generally used for base materials or base fabrics, such as resin films made of polyolefin resins, metal plates (or metal foils), glass plates, and glass woven fabrics.
The thickness of the substrate layer of the material to be transferred is not particularly limited, but can be, for example, in the range of 25 μm or more and 500 μm or less. Within the above range, it is easy to obtain an appropriate rigidity, and it is easy to balance the supportability and workability of the diffraction structure layer.
Examples of applications of the material to be transferred include laminates for laminate tubes, laminates for synthetic leather, and the like.

(Method for producing transferred material)
As a first method for producing a transfer material, for example, a resin composition for a diffraction structure layer is applied onto the obtained mold layer of the release paper by a bar coating method or the like, and only the diffraction structure layer of the transfer material is coated. is first formed.
Next, the diffraction structure layer is dried together with the release paper provided with the diffraction structure layer. Heating and pressurization may be performed as necessary.
After drying, the adhesive is applied to the diffraction structure layer on the release paper, the fabric is attached, and the adhesive is dried and aged.
Then, the release paper is peeled off to obtain a transferred material.

As a second method for producing a transfer material, for example, an original fabric of the transfer material (a laminate having an unshaped diffraction structure layer and a base material layer) is prepared, and the diffraction structure layer of the original fabric is prepared. The surface and the imprinting layer of the release paper are placed facing each other, and (thermally) pressed to transform the fine uneven structure of the imprinting layer of the release paper into the unimprinted diffractive structure layer of the raw material to be transferred. A method of transferring to .
Then, after cooling as necessary, the release paper can be peeled off to obtain a transferred material.
The raw material to be transferred may be a continuous sheet or a single sheet.

As a third manufacturing method, as shown in FIG. 4, a composition for a diffraction structure layer of a transfer material is applied to the surface of the mold layer of the release paper to form a diffraction structure layer, and then the necessary Depending on the above, a sheet for the substrate layer of the material to be transferred is attached, and the release paper is peeled off to obtain the material to be transferred.
The base material layer may be attached via an adhesive if necessary.
The applied composition takes the shape of the surface of the release paper-imparting layer, and the diffractive structure layer exhibits a diffractive gloss.
After coating, the surface mode of the diffraction structure layer can be fixed by an appropriate curing method according to the composition, such as drying by heating, ionizing radiation such as ultraviolet rays or electron beams, or cooling.
Although the method of applying the composition is not particularly limited, for example, a die coating method or the like can be applied.

Here, it is preferable to use roll-wound continuous sheet-like release paper as the release paper because of high productivity. Further, when the material to be transferred has a base layer, it is preferable to use a roll-wound continuous sheet for the base layer as the material for the base layer, which improves productivity. high and desirable.
Then, the transfer layer of the continuous sheet-like release paper and the surface of the continuous sheet-like sheet for the base material layer on which the diffraction structure layer is to be formed are opposed to each other and sandwiched between a pair of rolls to transfer the release paper. A molten composition for the diffraction structure layer is poured between the template layer and the sheet for the base material layer to laminate, and after cooling, the release paper is peeled off to obtain a continuous sheet-like transferred material.
The invention is not limited to these fabrication methods.

Raw materials specifically used in the examples are as follows.
Paper base material 1: sheet-wrapped woodfree paper having a basis weight of 125 g/m ² .
• Clay 1: General-purpose clay for paper substrates.
- Molding layer Molding part resin 1: homopolypropylene manufactured by SunAllomer Co., Ltd.;
- Resin 1 for the base portion of the mold layer: manufactured by SunAllomer Co., Ltd., a molten mixture of polypropylene/polyethylene at a mass ratio of 80/20.
· Anchor coating agent 1: Urethane-based anchor coating agent manufactured by Mitsui Chemicals, Inc., A-3210/A-3075 = mass ratio 1/1.
· Polyurethane 1: Polyurethane manufactured by Dainichiseika Kogyo Co., Ltd. Lezamin NE-8811.
- Colorant 1: Seika Seven NET-5794 (PM) black manufactured by Dainichiseika Kogyo Co., Ltd.
Adhesive 1: Polyurethane Lezamin NE-8811 manufactured by Dainichiseika Kogyo Co., Ltd.
・Fabric: Kinki Vinyl Co., Ltd., wet base.

<Preparation of Release Paper Raw Fabric 1>
By co-extrusion molding using the resin 1 for the transfer layer base and the resin 1 for the transfer layer transfer part, a transfer layer base (thickness 15 μm) and a transfer layer transfer part (thickness 15 μm) are formed on the paper substrate 1. ) to prepare a roll-wound release paper stock 1 having the following layer structure.
The surface of the imprinting layer imprinting part was mirror-finished with a mirror chill roll.
Layer structure: base layer (basis weight 125 g/m ² )/transfer layer [base (15 µm thick)/transfer part (15 µm thick)]

<Preparation of Release Paper Base Fabric 2>
First, a smoothing layer (15 μm) made of clay 1 was formed on a paper substrate 1 by cast coating, and then an anchor coat layer was formed using anchor coating agent 1.
Then, by co-extrusion using the transfer layer base resin 1 and the transfer layer transfer part resin 1, the transfer layer base (thickness: 15 μm) and transfer layer transfer part (thickness: 15 μm) are formed on the smoothing layer. 15 μm) to prepare a roll-wound release paper material 2 having the following layer structure.
The surface of the imprinting layer imprinting portion was mirror-finished with a mirror chill roll.
Layer structure: base layer (basis weight 125 g/m ² )/smoothing layer (15 μm thick)/anchor coat layer (1 μm)/imprint layer [base (15 μm thick)/imprinting part (15 μm thick)]

<Preparation of Release Paper Base Fabric 3>
A roll having the following layer structure was produced in the same manner as for the release paper raw roll 1, except that the surface of the imprinting layer imprinting portion was roughened using a mat chill roll whose roll surface was roughened by sandblasting. A rolled release paper material 3 was produced.
Layer structure: base layer (basis weight 125 g/m ² )/transfer layer [base (15 µm thick)/transfer part (15 µm thick)]

<Preparation of resin composition 1 for diffraction structure layer of transferred material>
The following raw materials were mixed and homogenized to prepare a resin composition 1 for a diffraction structure layer of a material to be transferred.
Polyurethane 15 parts by mass,
Colorant 1 1 part by mass

[Example 1]
(Preparation of release paper 1)
A raw release paper sheet 1 is sandwiched between an embossing roll 1 and a back roll so that the surface of the embossing layer contacts the surface of the embossing roll 1, and subjected to heat-pressure embossing (conveyance speed of the raw release paper sheet: 10 m/min). Then, the surface state of the embossing roll 1 was transferred to the transfer layer of the release paper raw roll 1 to produce the release paper 1 . Then, various evaluations were performed.
Surface aspect of embossing roll 1: Linear fine uneven structure. It is a pattern in which linear recesses and protrusions are alternately arranged and extend parallel to the MD direction (1 degree inclination) of the release paper 1, and the cross section is approximately triangular. The depth (height difference between unevenness) is 1000 nm, and the pitch (distance between protrusions or between recesses) is 2000 nm.

(Preparation of transfer material)
The diffraction structure layer resin composition 1 was applied onto the transfer layer of the obtained release paper 1 by a bar coating method to form a diffraction structure layer of the material to be transferred.
Next, the release paper 1 provided with the diffraction structure layer was dried at 80° C. for 3 minutes at a line speed of 10 m/min and a pressure of 25 N.
After drying, the adhesive 1 was applied to the diffraction structure layer on the release paper 1, and the fabric 1 was attached.
Then, after the adhesive 1 was dried and aged, the release paper 1 was peeled off to obtain a synthetic leather as an object to be transferred, and various evaluations were performed.

[Example 2]
(Preparation of Release Paper 2)
A raw release paper sheet 1 is sandwiched between an embossing roll 1 and a back roll so that the surface of the embossing layer contacts the surface of the embossing roll 1, and subjected to heat-pressure embossing (conveyance speed of the raw release paper sheet: 20 m/min). Then, the surface state of the embossing roll 1 was transferred to the transfer layer of the original release paper 1 to prepare the release paper 2 . Then, various evaluations were performed.
Then, the same operation as in Example 1 was performed to obtain a synthetic leather, which was a material to be transferred, and various evaluations were performed.

[Example 3]
(Preparation of Release Paper 3)
A raw release paper 2 is sandwiched between the embossing roll 1 and the back roll so that the surface of the embossing layer contacts the surface of the embossing roll 1, and subjected to heat-pressure embossing (conveyance speed of the raw release paper: 3 m/min). Then, the surface state of the embossing roll 1 was transferred to the transfer layer of the original release paper 1 to prepare the release paper 3 . Then, various evaluations were performed.
Then, the same operation as in Example 1 was performed to obtain a synthetic leather, which was a material to be transferred, and various evaluations were performed.

[Comparative Example 1]
A material to be transferred was produced in the same manner as in Example 1, except that the release paper stock 3 was used as the release paper stock, and various evaluations were performed in the same manner.

<Evaluation method>
[Glossiness]
Four A4-size test pieces were cut out from the release paper or the transferred material.
Concave/concave/convex portions of the fine concave-convex structure at an incident angle of 85 degrees and an observation angle of 85 degrees for a total of 5 points on the imprinting layer or diffraction structure layer of each test piece, the central portion, and the midpoint between the central portion and each corner. The glossiness G _MD in the direction in which the part extends (approximately MD direction) and the glossiness G _TD in the direction (approximately TD direction) orthogonal to the direction in which the concave/convex portions of the fine uneven structure extend are measured using a handy gloss meter (Japan Using a portable gloss meter PG-1M manufactured by Denshoku Kogyo Co., Ltd., measurements were taken three times according to JIS Z 8741-1997, and the average value was calculated.
For those without a fine uneven structure, the direction in which the recesses/projections of the fine uneven structure extend after molding and the direction perpendicular to the direction in which the recesses/projections of the fine uneven structure extend are the same. The gloss was measured at

[Luminance]
Ten test pieces each of 50 mm×100 mm were cut out from the release paper or the material to be transferred.
For each test piece, the luminance value, x value, and y value of the outer surface of the imprint layer or the diffraction structure layer, at an incident angle of 45 degrees and an observation angle of 45 degrees, in accordance with JIS Z 9117:2011, were measured as color luminance. Using a meter (CS-100A manufactured by Konica Minolta, Inc.), measurements were made three times and the average value was calculated.

[Microscopic observation of fine uneven structure]
Four A4-size test pieces were cut out from the release paper or the transferred material.
Using a shape analysis laser microscope (manufactured by Keyence Corporation, VK-X150, objective lens 100 times), the surface of each test piece was magnified and observed, and the pitch and depth of the fine uneven structure were measured by profile analysis.

[Releasability]
About 1,000 m of transfer material was continuously produced, and if the transfer material was easily separated from the release paper and there was no transfer failure (air entrapment) due to residual resin or air on the release paper, it was judged as good.
The meanings of the descriptions in the table are as follows.
◯: Good Δ: Slight transfer failure (air entrapment) due to resin residue or air inclusion.
x: Many transfer defects (air entrapment) due to residual resin or inclusion of air.

<Diffraction Gloss Visibility/Homogeneity>
A test piece of 100 mm square was cut out from the material to be transferred, placed on a desk, and under a test environment with an illumination of 400 lux (equivalent to a bright office), from a position 500 mm above, changing the direction and angle, a rainbow-pattern diffraction gloss was observed. Observed the visibility.
Ten observers (from 20's to 60's) observed from the direction in which the linear projections extend and from the direction perpendicular to it, and 6 or more observers were able to observe the rainbow-patterned diffractive gloss evenly at wide angles from both directions. It was judged as good.
The meanings of the descriptions in the table are as follows.
(Visibility)
◎: Very good ○: Good △: Weak diffraction gloss ×: No diffraction gloss (homogeneity)
◎: Very good ○: Good △: Uneven diffraction gloss ×: No diffraction gloss

<Summary of evaluation results>
The release paper of the example that satisfies the specification of the glossiness specified by the present invention at an incident angle of 85 degrees and the brightness specified by the present invention at an incident angle of 45 degrees exhibited good glossiness and brightness. The transfer material exhibited good releasability, uniform iridescence and good iridescence visibility.
On the other hand, even if the shaping layer has a fine concave-convex structure, it does not satisfy the glossiness specification of the present invention at an incident angle of 85 degrees and satisfies the brightness specification of the present invention at an incident angle of 45 degrees. The transfer material prepared using the release paper of Comparative Example 1 without iridescence had uneven iridescence and exhibited inferior iridescence visibility.

1 release paper 2 mold layer 2a mold portion 2b base portion 3 base layer P pitch D depth α linear recessed portion inclination angle 30 mold forming system 31 transfer material original roll 32 transfer material original roll 33 T die 34 substrate Composition melt for diffraction structure layer of transfer body 35 Release paper roll 36 Release paper (before use)
37 nip roll 1
38 Nip roll 2
39 Cooling machine 40 Release roll 41 Release paper (after use)
42 release paper (after use)
43 transfer material 44 transfer material roll 50 gloss measurement system 51 gloss light source 52 gloss clock 60 luminance measurement system 61 color luminance light source 62 color luminance meter

Claims (4)

A release paper for imprinting a surface aspect exhibiting diffraction gloss on a material to be transferred by transfer,
The release paper is a laminate having a substrate layer and a mold transfer layer that is the outermost layer on one side,
The outer surface of the imprinting layer has a fine uneven structure and exhibits diffraction gloss in the MD direction and the MD orthogonal direction of the release paper,
The fine concave-convex structure has linear recesses and protrusions that extend substantially parallel to the MD direction of the release paper and are alternately arranged to form a substantially triangular cross section,
In the glossiness measurement at an incident angle of 85 degrees in accordance with JIS Z 8741-1997 of the outer surface of the fine uneven structure,
The glossiness G1 _MD in the linear direction of the recesses and protrusions is 55 gloss or more and 98 gloss or less,
The glossiness G1 _TD in the direction orthogonal to the linear direction of the recesses and protrusions is 40 gloss or more and 80 gloss or less,
The average glossiness G1 _AVG of G1 _MD and G1 _TD is 50 gloss or more and 90 gloss or less,
The value of G1 _MD - G1 _TD is 8 gross or more and 45 gross or less,
In measuring the luminance of the outer surface of the mold layer in a direction perpendicular to the line direction of the recesses and protrusions in accordance with JIS Z 9117:2011, at an incident angle of 45 degrees,
The luminance C1 _TD is 700 cd/m ² or more and 1500 cd/m ² or less,
x1 value is 0.1 or more and 1.0 or less,
A release paper having a y1 value of 0.1 or more and 1.0 or less. 2. The release paper according to claim 1, wherein said substrate layer comprises a paper substrate. The release paper according to claim 1 or 2, wherein the mold transfer layer contains a thermoplastic resin. A material to be transferred, which is produced from the release paper according to any one of claims 1 to 3 and has a surface mode exhibiting diffraction gloss.

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