Release paper

Abstract

Provided is a release paper that is made up of a paper base layer and a surface resin layer and is shaped onto a shaped resin layer of synthetic leather, and that maintains the quality of the surface shape of the surface resin layer during transportation and storage. [Solution] A smoothing layer 45 is provided on the surface of a paper substrate 41, concealing and smoothing the fibers of the paper substrate. When the release paper 4 is rolled up and transported or stored, the surface of the paper substrate of the release paper and the surface of the surface resin layer 42 overlap, and even if a load is applied to this overlapping surface, the shape of the fibers of the paper substrate is not apparent and is not transferred to the resin layer. Therefore, the surface of the surface resin layer, which has an ornamental irregularity, is not damaged, and the quality of its surface shape is maintained.

Description

Technical Field

[0001] The present invention relates to a release paper, a method for manufacturing the release paper, an object to be shaped, and synthetic leather. More specifically, the present invention relates to a release paper for shaping a fine and uniform concavo-convex shape with few surface defects on the surface as an object to be shaped or synthetic leather, a method for manufacturing the release paper, and an object to be shaped and synthetic leather manufactured using the release paper.

Background Art

[0002] Conventionally, synthetic leather mainly made of vinyl chloride resin or polyurethane resin has been widely used. Such synthetic leather is often manufactured using release paper. For example, to manufacture polyurethane leather, a paste-like polyurethane resin is applied to the surface of the surface resin layer of the release paper, dried and solidified, and then a cloth substrate is laminated and peeled off from the release paper. If a squeezing pattern or concavo-convex shape similar to natural leather is formed on the release paper, a good pattern can be imparted to the surface of the obtained synthetic leather. Alternatively, a pattern that does not imitate natural objects such as a geometric pattern may be used.

[0003] The release paper used for manufacturing such synthetic leather transfers its surface pattern to form a surface pattern on the synthetic leather, and thus needs to have a surface state suitable for shaping.

[0004] Among them, a release paper in which an optical interference pattern due to extremely fine concavo-convexities is formed is disclosed (Patent Document 1).

[0005] In addition, in a release paper for synthetic leather in which a paper base material and a surface resin layer are laminated, unevenness corresponding to the pattern formed on the surface of the synthetic leather is formed on the surface resin layer of the release paper, and a release paper has been proposed in which the formed unevenness becomes more uniform and closer to the intended design.

[0006] An explanation will be given for this device. The unevenness on the surface of the paper base material on the side of the surface resin layer affects the surface of the surface resin layer, and unintended unevenness appears on the surface. When shaping synthetic leather, such unevenness deteriorates the finish of the synthetic leather. As a countermeasure, a release paper is disclosed in which the surface of the paper base material is smoothed and a surface resin layer is provided on the surface of the paper base material, so that the unevenness of the paper base material does not appear on the surface of the surface resin layer and the shaping of the pattern becomes good. (Patent Document 2)

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the release paper of Patent Document 1, although it is possible to form extremely fine unevenness, there is a problem of lack of uniformity on the surface of the release paper due to causes that occur after the production of the release paper.

[0009] Also, in the release paper of Patent Document 2, although a surface resin layer with good surface properties can be produced during the production of the release paper, there is a problem of lack of uniformity on the surface of the release paper due to causes that occur after the production of the release paper.

[0010] The problems that occur after production in Patent Document 1 and Patent Document 2 occur in the processes until the production of synthetic leather, such as during the transportation and storage of the release paper.

[0011] Figs. 1 to 6 are diagrams for explaining a conventional release paper. As shown in Fig. 1, after a paper base material and a resin layer are laminated, the release paper 2 is wound around a roll 1 and transported or stored. During its transportation or storage, the winding core 3 is often placed horizontally with respect to the ground plane. The surface on which the roll 1 is installed is a floor surface, a pallet surface, a truck bed (hereinafter referred to as the floor surface, etc.), and since it is placed on a plane, a stopper (not shown) is often installed so as to contact the outer peripheral portion of the roll and the floor surface, etc. to prevent rolling.

[0012] When the roll 1 is placed on the floor surface, etc., since the roll 1 has a cylindrical shape, the contact portion with the floor surface, etc. is substantially linear and the contact area is not large. The weight of the roll 1 acts on the contact portion between the roll 1 and the floor surface, etc. or near the contact portion. However, since the area of the contact portion is small, the pressure applied to the contact portion becomes large.

[0013] Also, when a stopper for preventing the roll 1 from rolling is installed, a pressing force is applied to the contact portion between the stopper and the roll.

[0014] Also, vibrations and impacts occur during transportation, and a pressing force is applied to the contact portion of the roll 1.

[0015] Furthermore, impacts also occur during loading and unloading. Also, at that time, an unexpected external force may be applied, such as the fork of a forklift hitting the roll 1.

[0016] Furthermore, in order to wind the web of the release paper 2 while applying tension, shrinkage of the web occurs after the roll 1 is completed, and the shrinkage force becomes a pressing force in the direction of the winding core 3. So-called winding tightening occurs, and the pressing force generated here becomes a pressing force in the cross-sectional direction of the release paper 2.

[0017] Also, those pressing forces affect the roll 1 individually, but may occur simultaneously. In that case, the pressing forces are added together and become larger.

[0018] An enlarged view of part A in FIG. 1 is shown in FIG. 2. Part A is a portion near the floor surface of roll 1 or the like. An enlarged view of part B in FIG. 2 is shown in FIG. 3. Part B is an enlarged cross-sectional view of the location where the surface 25 of the paper base material 21 of the release paper 2 and the surface 23 of the surface resin layer 22 of the release paper 2 are in contact.

[0019] In the conventional paper base material 21, the fibers of the paper base material 21 are apparent on the surface 25, and unevenness due to the fibers occurs. Protrusions 26 due to the fibers are formed on the surface 25 of the paper base material 21 and are in contact with the surface 23 of the surface resin layer 22. When a strong pressing force is applied in a direction perpendicular to the contact portion 27 between the surface 25 of the paper base material 21 of the release paper 2 and the surface 23 of the surface resin layer 22 of the release paper 2, as shown in FIG. 4, the protrusions 26 sink into the surface 23 of the surface resin layer 22, forming recesses 28. When the release paper 2 is unwound from the roll 1, the surface 25 of the paper base material 21 and the surface 23 of the surface resin layer 22 are peeled off, and defects of the recesses 28 appear on the surface 23 of the surface resin layer 22 of the release paper 2 as shown in FIG. 5. The recesses 28 are those where the protrusions 26 on the surface 25 of the paper base material 21 are transferred, and this phenomenon is called reverse transfer.

[0020] The recesses 28 impair the uniformity of the pattern of the shaped portion 24 on the surface 23 of the surface resin layer 22. A cross-sectional view of the synthetic leather 6 manufactured using such a release paper is shown in FIG. 6. Protrusions 64 appear on the surface of the shaped resin layer 61, resulting in defects. A detailed description of the synthetic leather will be given later.

[0021] The above description was about the roll, but the same problem also occurs with sheets. When sheets are stacked, a large self-weight is applied near the bottom layer, and there may also be cases where a pressing force is applied when other objects hit the sheets. In those cases as well, a pressing force is applied in the vertical direction of the surface of the release paper 2, and similar to the above roll, it may impair the uniformity of the pattern of the shaped portion 24 on the surface 23 of the surface resin layer 22 of the release paper 2.

[0022] The present invention has been made in view of the above situation, and even when unexpected external forces or internal forces such as winding occur during transportation or storage after the release paper is manufactured, the uniformity of the pattern on the surface of the surface resin layer of the release paper is not impaired, and an object of the present invention is to provide a release paper that can maintain its design property.

Means for Solving the Problems

[0023] The release paper of the present invention for solving the above problems is provided with a paper base material, a surface resin layer provided on one surface of the paper base material and having irregularities on the surface, and a smoothing layer provided on the other surface of the paper base material for smoothing the surface of the paper base material.

[0024] Further, the method for manufacturing the release paper of the present invention includes a step of preparing a master plate having a plate surface with irregularities corresponding to the irregularities formed on the surface resin layer, a step of forming the surface resin layer on one surface of the paper base material, and a step of forming a smoothing layer on the other surface of the paper base material. And a step of forming a shaping portion on the surface of the surface resin layer, a step of superposing the surface of the surface resin layer and the plate surface of the master plate to shape the irregularities, and a step of peeling the master plate from the release paper.

Effects of the Invention

[0025] According to the present invention, the surface of the paper base material of the release paper is smoothed, and even when the surface of the paper base material of the release paper and the surface of the surface resin layer are pressed against each other during storage or transportation by a roll, the surface resin layer can be provided with a release paper in which the uniformity and design property of the pattern on the surface are not impaired.

Brief Description of the Drawings

[0026]

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Mode for Carrying Out the Invention

[0027] Hereinafter, the present invention will be described with reference to the drawings. However, the present invention is not limited to these specifically illustrated forms or various specifically described structures.

[0028] In each figure, for the sake of clarity, the size and ratio of the members may be changed or exaggerated. Also, for the sake of visibility, parts that are not necessary for the explanation and repeated reference numerals may be omitted.

[0029] The release paper of the present invention is mainly used in the production of synthetic leather. In addition, it can also be used in the production of surface materials such as shoes, bags, sofas, chairs, vehicle seats, interior building materials such as boxes, packaging containers, wallpapers and floor materials, household appliances such as refrigerators and television receivers, and surface decorative materials for automotive parts such as dashboards and door interior panels. These articles are collectively referred to as the objects to be coated. In the following description, synthetic leather will be described as a representative example. <Release paper> The release paper of the present invention is a sheet for shaping unevenness with design on the shaped resin layer of synthetic leather. These days, higher quality closer to natural leather has been demanded for synthetic leather, and reproduction of finer unevenness has been required. Also, not only imitation of natural leather but also artificial patterns require design with finer unevenness and uniformity of the pattern to enhance the design. Furthermore, high-gloss mirror finish and the like have also been demanded.

[0030] FIG. 7 is a cross-sectional view of the release paper 4 of the present invention. On one surface of the paper base material 41, a surface resin layer 42 is provided, and on the surface 43 of the surface resin layer 42, a shaping portion 44 for shaping unevenness on the shaped resin layer of synthetic leather is provided.

[0031] And on the other surface of the paper base material 41, a smoothing layer 45 is provided.

[0032] Here, the shaping portion 44 shapes the shaping convex portion 46 and the shaping concave portion 47 on the shaped resin layer of synthetic leather that is the object of shaping, and forms unevenness on its surface. The shaping portion 44 can be formed by embossing using an original plate having a shape corresponding to the unevenness of the shaping portion 44.

[0033] Also, an anchor coat layer (not shown) may be formed between the paper base material 41 and the surface resin layer 42 to improve the adhesion between the layers. Further, an intermediate layer for the purpose of improving smoothness, plugging, or improving adhesion may be formed between the paper base material 41 and the surface resin layer 42.

[0034] As described above, the release paper 4 is used as a shaping mold for forming a shaped portion 63 on the surface of the shaped resin layer 61 constituting the synthetic leather 6, and since it has a shaping portion 44 corresponding to the shaped portion 63 of the synthetic leather 6, the synthetic leather 6 with a uniform uneven shape formed on the shaped resin layer 61 of the synthetic leather 6 can be easily produced.

[0035] Hereinafter, the components of the release paper 4 will be described in order. <Paper base material> The paper base material 41 serves as the support of the release paper 4.

[0036] As the pulp of the paper base material 41, in order to obtain strength and smoothness that can withstand the process of forming the shaping portion 44 and the process of manufacturing synthetic leather, a mixture of softwood pulp (N material) and hardwood pulp (L material) is preferable. In that case, in order to balance strength and smoothness, the mixing ratio of hardwood pulp (L material) is preferably 50% to 90%. The paper base material 41 needs to be neutral paper in order to obtain sufficient heat resistance of the release paper 4, and neutral paper sized using alkyl ketene dimer as a sizing agent is preferable.

[0037] The basis weight of the paper base material 41 is 100 g / m 2 ~200 g / m 2 which is preferable. If the basis weight is lower than 100 g / m 2 curls, undulations, or paper breakage on the production line are likely to occur during the production of synthetic leather. Conversely, if the basis weight is higher than 200 g / m 2 the embossing processability is poor, and since the release paper becomes thick, its winding diameter becomes large, the work efficiency decreases, and the cost further increases.

[0038] As for the thickness of the paper base material 41, those with a thickness of 100 μm to 900 μm, preferably 150 μm to 600 μm can be used. <Smoothing layer> The smoothing layer 45 is provided on at least the surface of the paper base material 41 (the opposite surface of the surface resin layer 42) and smooths the rough surface of the paper base material 41. The smoothing layer 45 is composed of, for example, a clay coat layer or the like.

[0039] The clay coat paint composition is composed of, for example, clay. As this clay, any material generally called clay can be used without particular limitation. Examples of the clay include kaolin, talc, bentonite, smectite, vermiculite, mica, chlorite, kibushi clay, gaylussite clay, halloysite, mica, etc. As the clay, talc has a low hardness (Mohs hardness 1) and excellent heat resistance, so it can improve heat resistance and dimensional stability during embossing. Furthermore, if the hardness of the smoothing layer 45 is high, deformation and scratches caused by external forces can be prevented, and the smoothness of the smoothing layer 45 can be better maintained.

[0040] In addition, the paint composition for the clay coat layer preferably contains, in addition to the clay, as pigments, calcium carbonate, titanium dioxide, amorphous silica, foaming barium sulfate, satin white, etc. By using calcium carbonate or titanium dioxide as the pigment, the smoothness of the surface of the clay coat layer can be increased. Furthermore, since calcium carbonate is inexpensive, it is preferably used.

[0041] The coating liquid for applying the clay coat layer contains the above-mentioned clay, a binder, and, if necessary, other pigments and additives in a solvent. As the solvent, usually, water, alcohol, etc. are used. As the binder, usually, latex-based binders (e.g., styrene-butadiene latex, acrylic latex, vinyl acetate latex), water-soluble binders (e.g., starch (modified starch, oxidized starch, hydroxyethyl etherified starch, phosphate esterified starch), polyvinyl alcohol, casein, etc.) are used. As the additives, pigment dispersants, defoamers, anti-foaming agents, viscosity regulators, lubricants, water resistance agents, water retention agents, etc. are used.

[0042] The coating method of the clay coat layer is not particularly limited, but coating methods such as the air knife coating method, the blade coating method, the short dwell coating method, etc. are used.

[0043] The coating amount and thickness of the clay coating layer are not particularly limited, but usually, the basis weight after drying is 5 g / m 2 ~40 g / m 2 and preferably 10 g / m 2 ~40 g / m 2 . If the basis weight after drying is less than 5 g / m 2 , the smoothness may be inferior. If the basis weight after drying exceeds 40 g / m 2 , there is a possibility of a decrease in adhesion due to aggregation failure of the clay coating layer, etc., and the cost performance is inferior.

[0044] Instead of the clay coating layer, a cast coating layer with higher smoothness can also be used.

[0045] The manufacturing method of cast coated paper having a cast coating layer is roughly classified into a wet method (direct method), a gelation method (coagulation method), or a rewett method (indirect method) according to the processing method for obtaining the gloss finish of the cast coating layer. That is, in the wet method, while the cast coating layer is in a wet state, it is pressure-bonded to a heated metal mirror drum and dried to finish with gloss. Also, in the gelation method, the cast coating layer in a wet state is passed through a coagulation liquid to be in a gelled state, and then pressure-bonded to a heated metal mirror drum and dried to finish with gloss. And in the rewett method, the cast coating layer in a wet state is once dried, then the cast coating layer is rewetted with a rewetting liquid to be in a plastic state, and then pressure-bonded to a heated metal mirror drum and dried to finish with gloss. Each manufacturing method is appropriately selected according to the required specifications of the cast coated paper.

[0046] Note that as the smoothing layer 45, instead of the clay coating layer, it may be formed by extrusion coating on either one side of the paper base material made of a polyolefin-based resin. Further, a film with smoothness on the surface such as a polyethylene terephthalate film or a polypropylene film may be subjected to dry lamination or extrusion lamination via an adhesive resin.

[0047] When using a material with a relatively rough surface, such as kraft paper or high-quality paper, as the paper substrate, the effect of improving the smoothness of the paper substrate is significant.

[0048] When the smoothing layer 45 is formed on the paper substrate 41 and measured using a shape analysis laser microscope (Keyence VK-8710), the arithmetic mean roughness Ra of the surface 80 of the smoothing layer 45 (Ra is the arithmetic mean roughness based on Japanese Industrial Standard JIS-B-0601-2001) is 2 μm or less. Also, if the arithmetic mean roughness Ra of the surface 80 of the smoothing layer 45 is less than 0.5 μm, it will result in excessive smoothness and become a cost factor. The measurement of the arithmetic mean roughness Ra is the average of the values measured 10 times in a 1 mm square area. The arithmetic mean roughness Ra described hereinafter is measured by the above-mentioned measuring instrument and method.

[0049] The thickness of the smoothing layer 45 is not particularly limited, but is preferably 10 μm to 60 μm, and the balance between performance and cost is excellent.

[0050] The smoothing layer 45 is provided at least on the surface side (the side opposite to the surface resin layer 42) of the paper substrate 41, but may or may not be provided on the surface of the paper substrate 41 on the side of the surface resin layer 42, and is appropriately selected according to the intended use and the like.

[0051] Since the surface 80 of the smoothing layer 45 of the paper substrate 41 has high smoothness, the quality can be maintained during the transportation and storage of the release paper 4. This effect will be described later.

[0052] (Anchor coat layer) The anchor coat layer (not shown) is provided on the adhesive surface of the paper substrate 41 and the surface resin layer 42 as necessary, and has a function of enhancing the adhesiveness between the paper substrate 41 and the surface resin layer 42.

[0053] The anchor coat layer can be formed, for example, by applying a water-soluble or water-dispersible emulsion or dispersion anchor coat agent.

[0054] Examples of this anchor coating agent include emulsions or dispersions of polypropylene-based, modified polyolefin-based, ethylene-vinyl acetate copolymer-based, polyethyleneimine-based, polybutadiene-based, polyurethane-based, and polyester-based resins, as well as polyvinyl chloride emulsion, urethane acrylate resin emulsion, silicone acrylate resin emulsion, vinyl acetate acrylate resin emulsion, acrylate resin emulsion, and rubber-based latexes such as styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, methyl methacrylate-butadiene copolymer latex, chloroprene latex, and polybutadiene latex, polyacrylate ester latex, polyvinylidene chloride latex, or carboxyl-modified products of these latexes. Also, as water-soluble anchor coating agents, aqueous solutions of polyvinyl alcohol, water-soluble ethylene-vinyl acetate copolymer, polyethylene oxide, water-soluble acrylate resin, water-soluble epoxy resin, water-soluble cellulose derivative, water-soluble polyester, water-soluble isocyanate, water-soluble lignin derivative, etc. can be used.

[0055] Among these, emulsions or dispersions of polypropylene-based or modified polyolefin-based resins are preferable in that they can further enhance the lamination strength of the polypropylene-based resin layer on paper and are excellent in heat resistance.

[0056] As a method for applying the above anchor coating agent, for example, it can be applied by a gravure coating method, a reverse roll coating method, a knife coating method, a kiss coating method, etc. The coating amount is preferably 0.1 g / m 2 ~5 g / m 2 after drying.

[0057] <Surface resin layer> The surface resin layer 42 has a shaped portion 44 formed on its surface and functions as a shaping mold when producing synthetic leather.

[0058] The additives contained in the surface resin layer 42 are not particularly limited, and for example, a mixture with inorganic or organic fine particles may be included.

[0059] Examples of the resin for the surface resin layer 42 include thermosetting or radiation-curable resins (including ultraviolet-curable resins, etc.) such as alkyd resins, melamine resins such as methylol melamine resin and methoxymethylol melamine resin, silicone resins, and acrylic resins. Further, as the resin for the surface resin layer 42, thermoplastic resins such as polyolefin resins such as polymethylpentene, polypropylene, and polyethylene can also be used. Considering the formability with the resin of the shaped resin layer 61 of the synthetic leather, one of these resins may be used alone or two or more of them may be used in combination.

[0060] Note that the surface resin layer 42 may further contain a dispersant, a viscosity modifier, a colorant, an antistatic agent, etc., as necessary.

[0061] From the viewpoint of durability, for example, the thickness of the surface resin layer 42 is preferably 10 μm or more, more preferably 20 μm or more. From the viewpoint of material cost, the thickness of the surface resin layer 42 is preferably 100 μm or less, more preferably 50 μm or less. In summary, the thickness of the surface resin layer 42 is preferably 10 μm or more and 100 μm or less, more preferably 20 μm or more and 50 μm or less.

[0062] Note that the thickness of the surface resin layer 42 is preferably set as appropriate in relation to the shape and size of the shaped portion 44.

[0063] Examples of the coating method for the surface resin layer 42 include an extrusion coating method, a roll coating method, a reverse roll coating method, a micro bar coating method, a bar coating method, a knife coating method, a gravure coating method, etc.

[0064] Also, a method of bonding the prepared films may be used. Examples include an extrusion lamination method, a dry lamination method, a wet lamination method, etc.

[0065] As a method for forming the smooth treatment surface before the uneven processing of the surface 43 of the surface resin layer 42, for example, after melt-extruding and laminating the paper base material 41 and the surface resin layer 42, continuously passing between a mirror-finished roll 72 with a mirror-finished surface and a pressing roll 71 so that the surface resin layer 42 contacts the mirror-finished roll 72 can improve the smoothness of its surface.

[0066] As shown in FIG. 7, a shaped portion 44 is formed on the surface of the surface resin layer 42. The shaped portion 44 is unevenness that functions as a shaping die for forming a shaped portion 63 on the surface of the shaped resin layer 61 of the synthetic leather 6. That is, the shaped portion 44 is unevenness corresponding to the shaped portion 63 of the shaped resin layer 61 in the synthetic leather 6. The shaped resin layer 61 of the synthetic leather 6, which is the object to be shaped by the shaped portion 44, can be die-pressed to form unevenness on its surface.

[0067] As described above, the release paper 4 according to the present invention can be preferably used for producing a synthetic leather 6 having the shaped resin layer 61 with unevenness formed on its surface before being shaped. <Workpiece to be shaped and synthetic leather> As shown in FIG. 8, in the present invention, the workpiece to be shaped 5 is a sheet-like article in which a surface pattern of a shaped portion 53 is formed on a shaped resin layer 51 using the release paper 4 of the present invention.

[0068] The workpiece to be shaped may be a roll-shaped continuous sheet or a single-sheet. The single-sheet workpiece to be shaped may be made from a single-sheet workpiece to be shaped sheet stock or may be obtained by cutting a continuous-sheet workpiece to be shaped sheet.

[0069] FIG. 8 is a sectional view showing an example of the workpiece to be shaped 5. The workpiece to be shaped 5 includes a shaped resin layer 51 and a base material layer 52, and these are laminated. A shaped portion 53 having a design property is provided on the surface of the shaped resin layer 51.

[0070] The thickness of the shaped resin layer 51 is not particularly limited and varies depending on the application and the depth of the unevenness.

[0071] The base material layer 52 of the shaped body 5 is a layer laminated on the surface opposite to the side where the unevenness of the shaped resin layer 51 is formed, and supports the shaped resin layer 51.

[0072] The thickness of the base material layer 52 is not particularly limited as long as it can support the shaped resin layer 51, but for example, it can be in the range of 25 μm or more and 500 μm or less.

[0073] For the material of the base material layer 52, any material that supports the shaped resin layer 51 and is appropriate according to the application of the shaped body 5 may be used. Natural fibers such as cotton, hemp, silk, and wool, regenerated or semi-synthetic fibers such as rayon and acetate, synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl alcohol, and polyolefin, woven fabrics, non-woven fabrics, mesh fabrics, etc. (also referred to as base fabrics) made of fibers such as glass fibers, paper, resin films made of resins such as polyester and polyolefin, metal plates, or metal foils, glass plates, glass woven fabrics, etc. Generally, those used for synthetic leather and the base material or base fabric of synthetic leather can be appropriately selected according to the type of resin and the application.

[0074] For the resin composition constituting the shaped resin layer 51, various thermoplastic resins, thermosetting resins, ionizing radiation curable resins such as ultraviolet rays or electron beams, etc. can be used, and can be appropriately selected according to the application, manufacturing conditions, etc.

[0075] Specific applications of the shaped body include, for example, surface materials for synthetic leather products, shoes, bags, sofas, chairs, vehicle seats, etc., boxes, packaging containers, interior building materials such as wallpaper and floor materials, household appliances such as refrigerators and television receivers, and surface decorative materials for automotive parts such as dashboards and door interior panels.

[0076] Among the above applications of the shaped body, synthetic leather is a field with relatively high demand, and the following will explain synthetic leather.

[0077] As shown in FIG. 8, the synthetic leather 6 according to the present invention is characterized by comprising a base material 62 and a shaped resin layer 61 formed on the entire surface of one surface of the base material 62. Since FIG. 8 has the same layer structure as the shaped body 5, the same figure is used for explanation, but the reference numerals are read as those corresponding to the synthetic leather.

[0078] Hereinafter, the components of the synthetic leather 6 will be described in order.

[0079] <Base material> The base material 62 constitutes the synthetic leather 6, and the shaped resin layer 61 is provided on one surface thereof. The base material 62 is not particularly limited, and known fabrics (base fabrics) used for synthetic leather, such as natural fabrics, non-woven fabrics, and artificial fabrics, can be appropriately selected and used. Further, as the base material, a resin sheet other than the fabric, or a structure coated with the resin sheet may be used. Examples of the resin material constituting such a resin sheet include vinyl chloride, urethane resin, unsaturated polyester resin, acrylic-urethane resin, acrylate resin, acrylamide resin, nitrocellulose resin, polystyrene resin, alkyd resin, and phenol resin.

[0080] When the base material 62 is in the form of a sheet, the thickness can be appropriately set according to the use of the synthetic leather. For example, from the viewpoints of durability, touch, etc., the lower limit is preferably 100 μm or more, more preferably 500 μm or more. Further, from the viewpoints of handleability, etc., the upper limit is preferably 20 mm or less, more preferably 10 mm or less.

[0081] When the base material 62 is in the form of a roll, the thickness is preferably 5 mm or less, more preferably 2 mm or less, from the viewpoint of ease of winding operation. The lower limit is preferably 100 μm or more, more preferably 500 μm or more, as in the case of the sheet.

[0082] <Shaped resin layer> The shaped resin layer 61 constitutes the synthetic leather 6 together with the above-mentioned base material and is formed on one surface of the base material 62. The surface of the shaped resin layer 61 has a shaped portion 63 formed thereon.

[0083] The shaped resin layer 61 is mainly composed of a resin material. Examples of the resin material for synthetic leather include thermoplastic resins, thermosetting resins, radiation-curable resins, etc. Specifically, vinyl chloride-based resins, urethane resins, etc. can be preferably employed.

[0084] The shaped resin layer 61 may optionally contain one or more selected from plasticizers, foaming agents, stabilizers, colorants, etc.

[0085] The color of the shaped resin layer 61 is not particularly limited, and it can be made into a desired color such as red or black using a colorant. The colorant may be a pigment or a dye and is not particularly limited. However, from the perspective of coloring up to the tip of the unevenness, it is more preferable to use a dye that has no such possibility rather than a pigment with a large particle diameter that may not enter up to the tip of the unevenness.

[0086] The thickness of the shaped resin layer 61 can be appropriately set according to the use purpose of the synthetic leather. From the perspective of durability, the lower limit of the thickness of the shaped resin layer 61 is preferably 10 μm, more preferably 30 μm. Similarly, the upper limit is preferably 200 μm, more preferably 150 μm, so as not to impair the texture of the synthetic leather.

[0087] In summary, the thickness of the shaped resin layer 61 is preferably 10 μm or more and 200 μm or less, more preferably 30 μm or more and 150 μm or less.

[0088] The shaped resin layer 61 may be formed by directly coating on the base material 62, or the base material and the resin layer may be bonded via an adhesive layer or the like. <Method for manufacturing release paper> A method for manufacturing the release paper 4 according to the present invention for forming unevenness in the shaped resin layer 61 of the synthetic leather 6 will be described.

[0089] Specifically, as shown in FIG. 9, the method for manufacturing the release paper 4 according to the present invention includes a step of preparing a master plate 74 having a plate surface 75 with unevenness corresponding to the shaped portion 63 formed in the shaped resin layer 61 of the synthetic leather 6, a step of preparing a laminated sheet 7 including a paper base material 41 and a surface resin layer 42 formed on the paper base material 41, a step of forming a smooth processed surface by processing the surface 43 of the surface resin layer 42 using a mirror finishing roll 72, a step of overlapping the smooth processed surface of the laminated sheet 7 and the plate surface 75 of the master plate 74 to shape the unevenness of the plate surface 75 on the surface 43 of the surface resin layer 42, and a step of peeling the laminated sheet 7 from the master plate 74.

[0090] <Preparation of the master plate> First, a master plate 74 having a plate surface 75 with unevenness corresponding to the shaped portion 63 formed in the shaped resin layer 61 of the synthetic leather 6 is prepared. The plate surface 75 is formed with unevenness corresponding to the shaped portion 63 shaped on the surface of the synthetic leather 6. In other words, when the release paper 4 manufactured by this method is used, a synthetic leather 6 having unevenness corresponding to the uneven structure of the plate surface 75 can be manufactured. The master plate 74 is not particularly limited as long as it has a strength capable of forming a shaped portion 44 on the release paper 4 and further has a strength capable of withstanding the temperature conditions, pressure conditions, etc. of each step in the forming process. As the material for the master plate 74, for example, a stainless steel plate, plated iron, plated copper, etc. can be used.

[0091] The means for producing the uneven structure on the plate surface 75 of the master plate 74 is not particularly limited. For example, an uneven structure can be formed on the material for the master plate 74 using means such as electrolytic plating, electroless plating, anodic oxidation treatment, etching, etc.

[0092] <Preparation of the laminated sheet> Furthermore, a laminated sheet 7 is prepared. The laminated sheet 7 includes a paper base material 41 and a surface resin layer 42 whose uneven shape is formed by a layout 75 on one surface of the paper base material 41, and is a sheet provided with a smoothing layer 45 on the other surface of the paper base material 41.

[0093] The paper base material 41 and the surface resin layer 42 may be directly joined, or may be joined via an intermediate layer. Examples of the intermediate layer include a layer for improving the bonding strength, a smoothing layer on the surface of the paper base material, and a layer for improving the formability of the surface resin layer.

[0094] The resin 73 is extruded from an extruder 70 and laminated on the paper base material 41 to prepare the laminated sheet 7.

[0095] The surface resin layer 42 may be a multi-layer of different resins. As an example, the layer structure of the release paper is [[Smoothing layer 45 surface]] / Paper base material / Resin A / Resin B / [[Forming portion 44 surface]] In the structure of, the physical properties required for Resin A and Resin B may be different. Since the temperature rises when manufacturing synthetic leather, Resin B is often required to have heat resistance, and Resin A is often required to have adhesiveness to both the paper base material and Resin B. In addition, since Resin A is not required to have as much heat resistance as Resin B, a cheaper resin can be adopted to reduce costs.

[0096] As a method for forming a multi-layer of the surface resin layer 42, the resin 73 in FIG. 9 may be extruded together from the extruder 70 as a multi-layer (not shown). Alternatively, a multi-layer resin film may be prepared and laminated. Or, Resin A may be melt-extruded as an adhesive resin and laminated with Resin B as a film.

[0097] As the lamination method, various known methods such as a dry lamination method and an extrusion lamination method can be applied.

[0098] [[Process of forming the smoothing treatment surface]] A smooth treatment surface is formed on the surface 43 of the surface resin layer 42 of the laminated sheet 7 by processing using a mirror finish roll 72. That is, the laminated sheet 7 is pressed between a pressing roll 71 positioned directly below an extruder 70 and the mirror finish roll 72, and the surface resin layer 42 is laminated onto the surface of the paper base material 41, whereby a smooth treatment surface can be formed.

[0099] As the mirror finish roll 72 used at that time, a mirror type roll that has been chrome plated on the roll and then subjected to traverse grinding, polishing processing, etc., or a semi-mirror type processing roll that has been subjected to wet blasting, dry blasting treatment, etc. is used. Further, the mirror finish roll 72 includes an ultrafine matte type processing roll as long as the surface of the processing roll is smoother than the surface 80 of the smoothing layer 45 of the paper base material 41. By using the mirror finish roll 72, the smoothness of the surface resin layer 42 can be improved.

[0100] Note that the surface of the mirror finish roll 72 may not only be a mirror type but may also have fine and minute irregularities, or a ground pattern may be created. It is desirable that the size of the irregularities of this ground pattern is smaller than the irregularities formed in the subsequent shaping process, and the size is appropriately set according to the designability of the release paper 4.

[0101] <Shaping process> Next, the surface resin layer 42 of the laminated sheet 7 and the plate surface 75 of the original plate 74 are overlapped and pressed between the pressing roll 76 and the original plate 74 to impart the unevenness of the plate surface 75 to the surface 43 of the surface resin layer 42. At this time, the original plate 74 is overlapped on the laminated sheet 7 so that at least a part of the surface resin layer 42 of the laminated sheet 7 is in contact with the plate surface 75 of the original plate 74. Thereby, the unevenness formed on the plate surface 75 of the original plate 74 is imparted to the surface resin layer 42 of the laminated sheet 7, and the release paper 4 is formed. The shaped portion 44 of the release paper 4 has an inverted shape of the unevenness of the plate surface 75. As this shaping process, shaping means can be appropriately selected in consideration of the material of the surface resin layer 42 and the like. The original plate 74 having the plate surface 75 can be a cylinder (roll) or a plate shape. The material of the pressing roll 76 may be a material that is easily deformed such as a paper roll, rubber, or elastomer, or a material that is difficult to deform such as metal, ceramic, or hard plastic, and is appropriately selected according to the layer configuration of the release paper 4, the type of resin, and the use.

[0102] <Peeling process> Next, the original plate 74 is peeled off from the laminated sheet 7. By this peeling process, the release paper 4 having the shaped portion 44 formed on the surface resin layer 42 can be obtained.

[0103] In each step of the above method for manufacturing the release paper 4, a heating step, a cooling step, a drying step, etc. can be appropriately included as necessary. Further, the method for manufacturing the release paper 4 according to the present invention is not limited to the above manufacturing method.

[0104] <Transportation and storage of release paper> After the peeling process, the release paper 4 is transported and stored in rolls or sheets. Since it is easy to transport and many processing forms can be selected in subsequent processes, it is often in the form of a roll. The ease of transportation means that there is a risk of load collapse during transportation in the form of stacked sheets, but it is difficult for rolls to experience load collapse. Also, "many processing forms" means that it is possible to supply it to the processing machine in the subsequent process as a roll or cut it into arbitrary dimensions.

[0105] The roll 1 of the release paper 4 of the present invention is shown in FIG. 1. Although this is the figure also used in the description of the conventional release paper 2 in the item of the problem to be solved by the invention, FIG. 2 should also be read as the reference numeral of the release paper 4 of the present invention. Further, the transportation, storage conditions, etc. of the roll 1 of the release paper 4 of the present invention are the same as those of the conventional release paper 2 and have already been described, so they will be omitted.

[0106] FIG. 1 shows the roll 1 of the release paper 4 according to the present invention, and an enlarged view of part A in FIG. 1 is shown in FIG. 2. Part A is a portion near the floor surface of the roll 1. Further, an enlarged view of part B in FIG. 2 is shown in FIG. 10. The surface 80 of the smoothing layer 45 of the paper base material 41 of the release paper 4 is in contact with the surface 43 of the surface resin layer 42 of the release paper 4. The surface 43 of the surface resin layer 42 is provided with a shaped portion 44 which is a pattern with irregularities.

[0107] As shown in FIG. 7, in the release paper 4 of the present invention, in the paper base material 41 of the release paper 4, the convex portions 49 formed by the paper fibers of the paper base material 41 are shielded by the smoothing layer 45 and cannot be confirmed from the appearance. Further, it is smoothed by the smoothing layer 45, and the surface 80 of the smoothing layer 45 has less irregularities.

[0108] The contact portion 48 between the surface 80 of the smoothing layer 45 of the paper base material 41 and the surface 43 of the surface resin layer 42 when the release paper 4 is wound in the form of a roll 1 and placed on the floor surface or the like is shown in FIG. 10. Although the contact portion 48 is drawn exaggeratedly so that there is a gap in FIG. 10, actually there is almost no gap and it is considered that they are almost in contact, but they are not in close contact.

[0109] When a pressing force is applied in the winding core direction, as shown in FIG. 11, the contact portion 48 is crushed, and the surface 80 of the smoothing layer 45 of the paper base material 41 and the surface 43 of the surface resin layer 42 are in close contact. Since the smoothing layer 45 is provided on the paper base material 41 of the release paper 4 of the present invention, the convex portions 49 formed by the fibers of the paper base material are not exposed, so the surface 43 of the surface resin layer 42 is not damaged.

[0110] Here, the pressing force refers to the pressing force caused by the self-weight of the release paper, the contact of the stopper, the contact of the forklift fork, winding tightness, etc. Moreover, there is a possibility that the above pressing forces may overlap to generate an even greater pressing force.

[0111] The size and weight of a typical release paper roll are approximately 1,200 mm in width, 600 mm in outer diameter, and 400 kg in weight. A large pressing force due to its self-weight is applied to the contact part between the outer peripheral part of the roll and the floor surface or the like.

[0112] As described above, in order for no defect to appear in the shaped part 44 of the surface resin layer 42 even when a pressing force is applied to the contact part between the surface 80 of the smoothing layer 45 of the paper base material 41 and the surface 43 of the surface resin layer 42, it is desirable that the smoothness of the surface 80 of the smoothing layer 45 of the paper base material 41, that is, the surface roughness, be within the following numerical range. When measured using a shape analysis laser microscope (Keyence VK-8710), the arithmetic mean roughness Ra (Ra is the arithmetic mean roughness based on Japanese Industrial Standard JIS-B-0601-2001) is 0.5 to 2.0 μm, and more desirably 0.6 to 1.5 μm. <Method for manufacturing synthetic leather> The manufacturing of the synthetic leather 6 is carried out according to the following procedure.

[0113] A step of preparing a laminated sheet 7 having a base material 62 and a resin layer 61 to be shaped provided on at least one surface of the base material 62, a step of preparing a release paper 4 for forming unevenness on the resin layer 61 to be shaped, a step of overlapping the resin layer 61 to be shaped of the laminated sheet 7 and the surface resin layer 42 of the release paper 4, and a step of peeling the release paper 4 after overlapping from the laminated sheet 7 to form a shaped part 63 on the surface of the resin layer 61 to be shaped of the laminated sheet 7.

[0114] First, the laminated sheet 7 and the release paper 4 are prepared. The laminated sheet 7 has a resin layer 61 to be shaped formed on the base material 62. The resin layer 61 to be shaped is a resin layer before unevenness is provided.

[0115] Next, the shaped resin layer 61 of the prepared laminated sheet 7 and the surface resin layer 42 of the release paper 4 are overlapped.

[0116] Thereafter, the release paper 4 after overlapping is peeled off from the laminated sheet 7, and a shaped portion 63 is formed on the surface of the shaped resin layer 61 of the laminated sheet 7. That is, by shaping the shaping portion 44 of the release paper 4 onto the shaped resin layer 61, unevenness with the pattern of the shaping portion 44 inverted is formed on the surface of the shaped resin layer 61.

[0117] A process for shaping the surface resin layer 42 of the release paper 4 provided with the shaping portion 44 onto the shaped resin layer 61 of the laminated sheet 7 in a state where they are overlapped is performed. Such a process is not particularly limited, and can be performed in consideration of the material of the resin layer and the like. For example, a hot embossing process of applying heat, a chill roll embossing process of pressing a resin softened by heat with a cooled roll, a process of curing with ultraviolet rays to cure the shaped shape, a process of curing with an electron beam to cure the shaped shape, and the like can be mentioned.

[0118] Among them, in the case of a hot embossing process of applying heat, it is preferable because it can smooth the spots due to the texture of the paper base material.

[0119] Also, depending on the material of the shaped resin layer 61 of the laminated sheet 7, for example, when a polyvinyl resin is used, the paste coating method can be used, and when a urethane resin is used, a dry process can be used. Conditions such as the temperature and pressure of the process are not particularly limited, and can be appropriately set according to the process adopted and the type of resin contained in the resin layer.

[0120] As shown in FIG. 12, by peeling off the release paper 4, synthetic leather 6 with a shaped portion 63 formed on the surface of the shaped resin layer 61 can be obtained. Various conditions such as the peeling speed and temperature of the release paper 4 at the time of peeling, and the peeling means are not particularly limited. <Release paper for shaped body, and method for manufacturing shaped body> The release paper of the present invention can also be applied to substrates other than synthetic leather. The manufacturing method of the release paper for substrates is the same as that for synthetic leather.

[0121] In the manufacturing method of the substrate, the resin layer to be shaped, materials, etc. corresponding to the use of the substrate are appropriately selected, and the processing method and processing conditions are also appropriately selected.

Example

[0122] The present invention will be further specifically described by way of examples.

[0123] <Production of Release Paper> (Example 1) As the paper substrate, cast-coated paper (basis weight 164 g / m 2 , cast coat layer 10 μm to 40 μm, OK process release paper, manufactured by Oji Paper Co., Ltd.) was prepared.

[0124] Corona treatment was performed on the paper surface on the opposite side of the cast coat layer of this paper substrate. The first polypropylene resin (manufactured by Sun Allomer, polyethylene melt blend) was extruded from the first extruder of the co-extruder at 310 °C, and on top of that, the second polypropylene resin (homopolypropylene, manufactured by Sun Allomer) was extruded from the second extruder of the co-extruder at 305 °C at a line speed of 80 m / min to obtain a laminated sheet. The first polypropylene resin has the property of improving the adhesiveness between the paper substrate and the second polypropylene resin, and the second polypropylene resin has heat resistance. By using these resins in multiple layers, a release paper with a balance between interlayer adhesiveness and heat resistance could be produced.

[0125] Next, immediately after that, the surface of this laminated sheet was extrusion-coated with a mirror-finishing roll to smooth the surface of the resin layer with a thickness of 30 μm, and a surface resin layer was obtained.

[0126] Note that the layer structure is 〔Cast coat layer〕 / Cast-coated paper (basis weight 164 g / m 2 ) / First polypropylene resin layer (15 μm) / Second polypropylene resin layer (15 μm) / 〔Shaped surface〕 It is as follows.

[0127] In addition, in order to facilitate the confirmation of the effects of the present invention, the shaped surface is mirror-finished by the mirror-finishing roll, and no unevenness is processed by embossing.

[0128] The arithmetic mean roughness Ra of the surface of the cast coat layer of the paper base material was 0.65 μm.

[0129] (Example 2) Instead of the paper on which the cast coat layer of Example 1 was formed, paper on which a clay coat layer was formed (basis weight 174.4 g / m 2 Ultra Satine Kintoki, manufactured by Oji Paper Co., Ltd.) was used. Other processing methods and materials were the same as those in Example 1.

[0130] The arithmetic mean roughness Ra of the surface of the paper base material was 1.32 μm.

[0131] (Example 3) Instead of the paper on which the cast coat layer of Example 1 was formed, paper on which a clay coat layer was formed (basis weight 260 g / m 2 N Pearl Card, manufactured by Mitsubishi Paper Mills Ltd.) was used. Other processing methods and materials were the same as those in Example 1. The arithmetic mean roughness Ra of the surface of the paper base material was 1.92 μm. (Comparative Example) Instead of the paper base material on which the cast coat layer of Example 1 was formed, so-called uncoated high-quality paper (basis weight 125 g / m 2 AKD, manufactured by Kitakoshi Paper Co., Ltd.) without a cast coat layer or a clay coat layer was used. Other processing methods and materials were the same as those in Example 1.

[0132] The arithmetic mean roughness Ra of the surface of the paper base material was 3.15 μm.

[0133] (Evaluation of back transfer) In order to confirm the effects of the present invention, the conditions of back transfer were reproduced and evaluated. Prepare two sheets of release paper produced under the same conditions. After overlapping the surface of one paper substrate and the other surface resin layer, pass the overlapped sheets through between a pair (two) of parallel metal rolls and press them. The metal rolls rotate by themselves and rotate in opposite directions to each other, so that the sheet can be grasped and pressed.

[0134] The outer cylindrical surface of the metal roll is mirror-finished, and the metal roll rotates around its axis. The axis of the first metal roll is rotatable and its position is fixed, and the axis of the second metal roll is rotatable and can move in a direction in which the distance from the first metal roll can be adjusted. Also, the second metal roll can vary the pressing force on the first metal roll.

[0135] For the pressing conditions of the metal roll, the feed rate was set at 1 m / min and the surface temperature was set at 25 °C, and two conditions of pressing forces of 100 kN / m and 200 kN / m were used to create samples. Ten samples were created for each condition.

[0136] Engage and press between the metal rolls set under the above conditions, then peel off the two sheets of release paper and observe the surface of the surface resin layer that had been in contact with the paper substrate.

[0137] The samples produced were evaluated according to the following items.

[0138] 1. Appearance observation: Visual inspection and magnified observation of the surface using a microscope (Keyence VK-8710) 2. Gloss measurement: Use a gloss meter (HORIBA GLOSS CHECKER IG-320) 3. Measurement of arithmetic mean roughness: Use a shape analysis laser microscope (Keyence VK-8710) (Appearance observation) Among the appearance observations, the visual inspection was carried out in a test environment with an illuminance of 400 lux (equivalent to a bright office). A 100 mm square sample cut from the transfer sample produced by the above procedure was placed on a table, and five subjects (quality control and technical personnel) visually inspected it from a position 500 mm above and made a judgment.

[0139] It was determined whether cloudiness had occurred in the mirror-finished surface resin layer of the release paper or whether the shape of the fibers of the paper base material had been transferred to the surface resin layer.

[0140] In addition, using a shape analysis laser microscope (VK-8710) manufactured by Keyence, photographs were taken at a magnification of approximately 100 times.

[0141] (Measurement of glossiness) For the examples and comparative examples of the back-transfer samples, measurements were taken using a gloss meter (IG-320 <60° reflection>) manufactured by Horiba, Ltd. The measurements were taken 10 times and the average value was used.

[0142] (Measurement of arithmetic mean roughness) For the examples and comparative examples of the back-transfer samples, measurements were taken with a shape analysis laser microscope (VK-8710) manufactured by Keyence. It is the average of the values measured 10 times in a 1 mm square area.

[0143] The above evaluation results are summarized in Table 1.

[0144]

Table 1

[0145] Among the samples after pressing, samples S3 (Fig. 15) and S7 (Fig. 19), which are the release papers of Example 1 of the present invention, and samples S4 (Fig. 16) and S8 (Fig. 20), which are the release papers of Example 2 of the present invention, are good products. Sample S5 (Fig. 17), which is the release paper of Example 3 of the present invention, is a good product, and although sample S9 (Fig. 21) also has a slight quality degradation, it can be regarded as a good product.

[0146] In conventional release papers, in sample S2 (Fig. 14), there is transfer of paper base material fibers, and a decrease in quality is observed. In sample S6 (Fig. 18), the transfer of paper base material fibers is significant, and it is a defective product.

[0147] Note that the thin streaks running from the top to the bottom of the photos that are common to all photos are marks on the surface of the mirror-finished roll and are hardly visible to the naked eye. Therefore, the surface of the surface resin layer of the release paper maintains a mirror finish.

[0148] Regarding the determination, mainly the appearance was visually inspected. However, it was found that for samples pressurized at 100 kN / m, if the decrease in glossiness measured with a measuring instrument was within 10% of the initial value, it almost coincided with the evaluation of being a non-defective product in the visual inspection. Therefore, it was found that the determination could be made by measuring the glossiness rather than the visual work of the inspector.

[0149] The overall measured values of the surface roughness at 200 kN / m pressure in Table 1 are larger than the measured values of the surface roughness at 100 kN / m pressure, but the determination by visual observation does not change significantly.

[0150] This is presumably because the measurement of the surface roughness of the samples pressurized at 200 kN / m picks up the variations in the density in the plane direction of the paper significantly, and it is difficult to apply it to the evaluation of the smoothness of the paper surface. That is, by strongly compressing the paper in the thickness direction, the areas with high paper density become convex, and the areas with low paper density become concave. Therefore, it is more affected by the variations in the density in the plane direction of the paper than the smoothness of the paper surface.

[0151] The clay coat layer has the effect of enhancing the smoothness of the paper surface. Furthermore, even if the paper is strongly compressed in the thickness direction and the surface roughness becomes rough in the measured values, it has the effect of not transferring the shape of the paper fibers to the surface resin layer of the release paper. This is because the effect of concealing the unevenness of the paper fibers with the clay coat layer is high.

[0152] In this way, even when the release paper of the present invention is pressed in a stacked state, back transfer does not occur, and the shape of the shaped portion can be maintained in a good state. In other words, when transporting and storing the release paper, even if a large external force or internal stress occurs, the quality is less likely to be impaired. Therefore, it is not only useful for maintaining quality, but also does not require excessive consideration for transportation work and storage work, and can contribute to improving work efficiency and reducing costs.

Industrial Applicability

[0153] According to the release paper of the invention, it is possible to prevent deterioration of the quality of the release paper, particularly during transportation and storage, and contribute to improving the quality and reducing the cost of various shaped articles such as synthetic leather manufactured using the release paper.

Explanation of Signs

[0154] 1 Release paper roll 2 Release paper (conventional product) 21 Paper base material (conventional product) 22 Surface resin layer (conventional product) 23 Surface of the surface resin layer (conventional product) 24 Shaped portion (conventional product) 25 Surface of the paper base material (conventional product) 26 Protrusion by paper fibers (conventional product) 27 Contact portion (conventional product) 28 Recessed portion (conventional product) 3 Core 4 Release paper (of the present invention) 41 Paper base material (of the present invention) 42 Surface resin layer (of the present invention) 43 Surface of the surface resin layer (of the present invention) 44 Shaped portion (of the present invention) 45 Smoothing layer 46 Shaped protrusion 47 Shaped recess 48 Contact portion (of the present invention) 49 Protrusion by paper fibers (of the present invention) 5 Shaped article 51 Shaped resin layer (shaped article) 52 Base material layer (shaped article) 53 Shaped part (shaped body) 6 Synthetic leather 61 Shaped resin layer (synthetic leather) 62 Base material layer (synthetic leather) 63 Shaped part (synthetic leather) 64 Protrusion (synthetic leather) 7 Laminated sheet 70 Extruder 71 Pressing roll (for mirror finishing) 72 Mirror finishing roll 73 Resin 74 Master 75 Plate surface 76 Pressing roll (for shaping) 80 Surface of the smoothing layer of the paper base material S1 Sample for reverse transfer evaluation (see Table 1) S2 Sample for reverse transfer evaluation (see Table 1) S3 Sample for reverse transfer evaluation (see Table 1) S4 Sample for reverse transfer evaluation (see Table 1) S5 Sample for reverse transfer evaluation (see Table 1) S6 Sample for reverse transfer evaluation (see Table 1) S7 Sample for reverse transfer evaluation (see Table 1) S8 Sample for reverse transfer evaluation (see Table 1) S9 Sample for reverse transfer evaluation (see Table 1)

Claims

1. A paper substrate, a surface resin layer provided on one surface of the paper substrate and having irregularities on the surface, a smoothing layer provided on the other surface of the paper substrate and smoothing the surface of the paper substrate are provided, the smoothing layer is a clay coat layer, The coating amount of the clay coat layer is 5 g / m² 2 to 40 g / m² 2 in terms of the basis weight after drying, and the roll-shaped release paper is characterized by this.

2. The release paper according to claim 1, wherein the arithmetic mean roughness Ra of the surface of the smoothing layer is 0.50 to 2.00 μm.

3. The release paper according to claim 1 or 2, wherein the thickness of the smoothing layer is 10 μm to 60 μm.

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