JP6922214B2 - How to make release paper, synthetic leather, and release paper - Google Patents

Description

The present invention relates to a paper pattern, synthetic leather, and a method for producing the paper pattern. More specifically, the present invention relates to a release paper for shaping fine uneven shapes into synthetic leather without uneven gloss, synthetic leather produced using this release paper, and a method for producing the release paper.

Conventionally, synthetic leather mainly made of vinyl chloride resin or polyurethane resin has been widely used. Such synthetic leather is often manufactured using a paper pattern. For example, in order to produce polyurethane leather, a paste-like polyurethane resin is applied on a release paper, dried and solidified, and then a cloth base material is attached and peeled from the release paper. If a squeezed pattern or uneven shape similar to that of natural leather is formed on the release paper, a good pattern can be imparted to the surface of the obtained synthetic leather.
The release paper used for producing such synthetic leather transfers the surface pattern to form the surface pattern on the synthetic leather, and needs to have a surface state suitable for shaping.
Among them, a release paper in which an optical interference pattern due to fine irregularities is formed is disclosed (Patent Document 1).

Japanese Unexamined Patent Publication No. 3-136753

However, in the paper pattern of Patent Document 1, although it is possible to form fine irregularities, there is a problem that the surface uniformity is lacking. Kraft paper, woodfree paper, etc. are used as the paper base material, and if the surface smoothness of the paper base material is insufficient, the surface smoothness of the paper pattern is inferior, and as a result, this paper pattern is used. This is thought to be because the smoothness of the surface of the release paper is transferred as it is when synthetic leather is produced.

The present invention has been made in such a situation, and is a paper pattern capable of forming a fine uneven surface without uneven gloss on the surface of synthetic leather, and is manufactured by using this paper pattern. It is an object of the present invention to provide synthetic leather and a method for producing this paper pattern.

The release paper of the present invention for solving the above problems is a release paper for forming fine irregularities on the resin layer of the synthetic leather, and is formed on one surface of the paper base material and the paper base material. The smoothing layer includes a smoothing layer for smoothing the surface and a synthetic resin layer formed on the smoothing layer, and the smoothing layer is a clay having an arithmetic average surface roughness Ra of 0.1 μm or less. The synthetic resin layer is composed of a coat layer, and the synthetic resin layer is a thermoplastic resin obtained by mixing one or more of polymethylpentene, polypropylene, and polyethylene, and the entire final surface of the synthetic resin layer constituting the release paper. There is a smooth treated surface, and the gloss value of the surface is 81% or more and 95% or less, the synthetic resin layer, is shaping mold for forming the fine unevenness on the resin layer An anchor coat layer is formed between the smoothing layer and the synthetic resin layer, and the anchor coat layer is an emulsion or dispersion of a polypropylene resin or an emulsion of a modified polyolefin resin. or wherein the anchor coating agent der Rukoto dispersions.

Further, in the release paper of the present invention, the synthetic resin layer may have a layer thickness of 20 μm or more and 100 μm or less .

Further, the method for producing the release paper of the present invention is a method for producing the release paper for forming fine irregularities on the resin layer of the synthetic leather, and has an uneven structure corresponding to the fine irregularities formed on the resin layer. The step of preparing the original plate on which the plate surface to be held is formed, the paper base material, the smoothing layer formed on the paper base material, and the synthetic resin layer extruded from the extruder are laminated on the smoothing layer. , The step of preparing the laminated sheet, the step of forming the smoothed surface by processing the surface of the synthetic resin layer with a mirror surface roll, and the step of superimposing the smoothed surface of the laminated sheet and the plate surface of the original plate. a step of shaping the fine unevenness of the printing plate on the surface of the resin layer, e Bei and a step of peeling the original from the laminated sheet, the smoothing layer is an arithmetic average surface roughness Ra 0. The synthetic resin layer is made of a clay coat layer of 1 μm or less, and the synthetic resin layer is a thermoplastic resin in which one or more of polymethylpentene, polypropylene, and polyethylene are mixed, and the smoothing surface is the surface of the synthetic resin layer. gloss value of 81% or more, and the der Rukoto than 95%.

According to the release paper of the present invention, since the smoothing layer is formed on the paper base material, the surface of the release paper becomes smooth. Therefore, it is possible to form a fine uneven shape with no uneven gloss on the surface of the synthetic leather.

It is sectional drawing which shows one Embodiment of the paper pattern in 1st Embodiment of this invention. It is sectional drawing which shows one Embodiment of the paper pattern in 2nd Embodiment of this invention. It is sectional drawing which shows an example of the synthetic leather of this invention. It is a figure for demonstrating the manufacturing method of the paper pattern of this invention. It is a figure for demonstrating the manufacturing method of the synthetic leather of this invention. It is a figure for demonstrating the shaping process of the paper pattern of an Example. It is a figure for demonstrating the shaping process of the paper pattern of the comparative example.

Hereinafter, an embodiment of the release paper of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

[Release paper]
The release paper 20 according to the present invention is a sheet for forming fine irregularities on the resin layer of the synthetic leather according to the present invention.
As shown in FIG. 1, the paper pattern is provided with a paper base material 22 and a smoothing layer on at least one surface of the paper base material 22, and further provided with a synthetic resin layer 26 on the smoothing layer. The surface of the synthetic resin layer 26 is a smoothed surface, and a shaped mold 12 having convex portions and concave portions for forming fine irregularities on the resin layer of the synthetic leather is formed.

Here, the shaping mold 12 is formed by shaping the shaping fine convex portion structure 14 and the shaping fine concave portion structure 16 into a resin layer of synthetic leather to be embossed to form fine irregularities on the surface thereof. When formed, it means fine irregularities on the surface of the release paper formed so that the gloss value of the resin layer is in the range of 1 or more and 30 or less. The fine uneven structure for shaping can be formed by embossing using an original plate having a pattern of a shape corresponding to the fine unevenness.
Further, as shown in FIG. 2, an anchor coat layer may be formed between the smoothing layer 24 and the synthetic resin layer 26 in order to improve the interlayer adhesion. Further, an intermediate layer that plays a role of improving smoothness and sealing may be formed between the smoothing layer 24 and the synthetic resin layer 26.

The release paper 20 is used as a shaping pattern 12 for forming fine irregularities on the surface of the resin layer constituting the synthetic leather. Since the release paper has a fine uneven structure for shaping corresponding to the fine unevenness, it is possible to easily produce synthetic leather having an uneven shape having uniform and fine concave and convex portions on the entire surface of the resin layer. can.

Hereinafter, the components of the paper pattern 20 will be described in order.

(Paper base material)
The paper base material 22 serves as a support for the paper pattern.
Paper-based pulp includes softwood pulp (N material) and hardwood pulp (L material) in order to obtain strength and smoothness that can withstand the process of forming fine uneven structures for shaping and the process of producing synthetic leather. ) Is mixed. In that case, in order to improve the smoothness, the mixing ratio of the hardwood pulp (L material) is preferably 50% to 90%. The paper base material may be acid-free paper in order to obtain sufficient heat resistance of the release paper. It is necessary, and a neutral paper sized using an alkyl keten dimer as a sizing agent is preferable.

The basis weight of the paper substrate 22, the strength, it is preferred synthetic leather processing workability, a repeated use durability and the surface of the embossing suitability 100g / m ² ~200g / m ² of release paper. If the basis weight is ^{lower than 100 g / m 2} , curls and waviness are likely to occur during the production of synthetic leather. On the contrary, when the basis weight is ^{higher than 200 g / m 2} , the embossing workability is poor, and the thickening of the paper pattern increases the winding diameter and lowers the work efficiency.
The thickness of the paper base material 22 can be 100 μm to 900 μm, preferably 150 μm to 600 μm.

(Smoothing layer)
The smoothing layer 24 is provided on at least one surface of the paper base material 22 to smooth the rough surface of the paper base material.

The smoothing layer 24 is composed of, for example, a clay coat layer, and is formed by applying it to either surface of a paper substrate.
The clay coat layer contains clay, and the clay can be used without particular limitation as long as it is generally called clay or clay. As the clay, for example, kaolin, talc, bentonite, smectite, vermiculite, mica, chlorite, knot clay, gairome clay, halloysite, mica and the like can be used. As clay, talc has a low hardness (Mohs hardness 1) and is excellent in heat resistance, so that it is possible to improve heat resistance and dimensional stability during embossing. Further, the higher the hardness of the smoothing layer 24, the less affected the texture of the paper base material in the synthetic resin layer formed on the smoothing layer, and as a result, the surface of the synthetic resin layer becomes uniform. , The transferability (formability) of the uneven structure of the plate surface is improved.

The clay coat layer preferably contains calcium carbonate, titanium dioxide, amorphous silica, effervescent barium sulfate, satin white and the like as pigments in addition to clay. By using calcium carbonate or titanium dioxide as the pigment, the smoothness of the surface of the clay coat layer can be improved. Furthermore, since calcium carbonate is inexpensive, it is preferably used.

The coating liquid for applying the clay coat layer contains the above clay, a binder, and other pigments and additives as necessary in the solvent. As the solvent, water, alcohol or the like is usually used. The binder is usually a latex-based binder (for example, styrene-butadiene latex, acrylic-based latex, vinyl acetate-based latex), or a water-soluble binder (for example, starch (modified starch, oxidized starch, hydroxyethyl etherified starch, phosphate ester). Chemicalized starch), polyvinyl alcohol, casein, etc.) are used. As the additive, a pigment dispersant, a defoaming agent, an antifoaming agent, a viscosity modifier, a lubricant, a water resistant agent, a water retaining agent and the like are used.

The coating method of the clay coat layer is not particularly limited, but a coating method such as an air knife coat, a blade coat, a short dwell coat, or a cast coat is used.

The coating amount and thickness of the clay coat layer is not particularly limited, the basis weight after drying was ^{5g / m 2 ~40g / m 2} , 10g / m 2 ~40g / m 2 is preferred. 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 that the adhesion may be lowered due to the cohesive failure of the clay coat layer, which is inferior in terms of cost performance.

The smoothing layer 24 may be formed of a polyolefin-based resin instead of the clay coat layer by extrusion-coating on either surface of the paper substrate.
When a material having a relatively rough surface such as kraft paper or woodfree paper is used as the paper base material, the smoothness on the paper base material can be improved.

When such a smoothing layer 24 is formed on a paper substrate and measured using a shape analysis laser microscope (VK-8710 manufactured by KEYENCE CORPORATION), the arithmetic mean surface roughness Ra (Ra) of the smoothing layer is , Arithmetic mean roughness based on Japanese Industrial Standard JIS-B-0601-2001) is 0.1 μm or less. The thickness of the smoothing layer is also not particularly limited, but is 10 μm to 60 μm.

(Anchor coat layer)
The anchor coat layer 28 is provided on the smoothing layer as needed, and adheres the smoothing layer and the synthetic resin layer.
When the smoothing layer is a clay coat layer, the surface of the clay coat layer has good slipperiness, so that the adhesiveness to the extruded and laminated synthetic resin tends to be inferior. It has a function of enhancing the adhesiveness with the layer.
The anchor coat layer 28 can be formed, for example, by applying a water-soluble or water-dispersible emulsion or dispersion anchor coat agent.
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 emulsions and urethane acrylics. Resin emulsion, silicon acrylic resin emulsion, vinyl acetate acrylic resin emulsion, acrylic resin emulsion, and styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, methyl methacrylate-butadiene copolymer latex, chloroprene latex, polybutadiene latex. Rubber-based latex such as, polyacrylic acid ester latex, polyvinylidene chloride latex, or carboxyl-modified products of these latex, and as the water-soluble anchor coating agent, polyvinyl alcohol, water-soluble ethylene-vinyl acetate copolymer, polyethylene An aqueous solution of an oxide, a water-soluble acrylic resin, a water-soluble epoxy resin, a water-soluble cellulose derivative, a water-soluble polyester, a water-soluble isocyanate, a water-soluble lignin derivative, or the like can be used.

Among these, an emulsion or dispersion of a polypropylene-based or modified polyolefin-based resin is preferable because it can further increase the lamination strength of the polypropylene-based resin layer with respect to paper and is also excellent in heat resistance.

The anchor coating agent can be applied by, for example, a gravure coating method, a reverse roll coating method, a knife coating method, a kiss coating method, or the like. / ^{M 2 to 5} g / m ² is preferable.

(Synthetic resin layer)
The surface of the synthetic resin layer 26 has a fine concavo-convex structure for shaping, and functions as a shaping mold when producing synthetic leather.
The material contained in the synthetic resin layer 26 is not particularly limited, but may include, for example, a mixture with inorganic or organic fine particles.

Examples of the resin of the synthetic resin layer 26 include melamine resins such as alkyd resin, methylol melamine resin and methoxymethylol melamine resin, thermosetting resins such as silicone resins and acrylic resins (ultraviolet curable resins and the like). Including.) Etc. can be mentioned. Further, as the resin of the synthetic resin layer, a thermoplastic resin such as a polyolefin resin such as polymethylpentene, polypropylene, or polyethylene can also be used. These resins may be used alone or in combination of two or more in consideration of the formability of the resin layer of the synthetic leather with the resin.
The synthetic resin layer may further contain a dispersant, a viscosity modifier, a colorant, an antistatic agent, and the like, if necessary.

The thickness of the synthetic resin layer 26 is preferably 10 μm or more, more preferably 20 μm or more, for example, from the viewpoint of durability. From the viewpoint of material cost, the thickness of the synthetic resin layer is preferably 100 μm or less, more preferably 50 μm or less. The thickness of the synthetic resin layer is preferably determined as appropriate in relation to the fine uneven structure for shaping.

Examples of the coating method of the synthetic resin layer 26 include an extrusion coat, a roll coat, a reverse roll coat, a micro bar coat, a bar coat, a knife coat, and a gravure coat.

As a method for forming the smoothed surface 10 on the surface of the synthetic resin layer 26, for example, after melt-extruding and laminating the synthetic resin layer on the smoothed layer, the surface is continuously pressed with a mirror-finished mirror-finished roll. By passing the synthetic resin layer in contact with the mirror surface roll between the rolls, the smoothness of the surface can be improved.

As shown in FIG. 1, a fine uneven structure for shaping is formed on the surface of the synthetic resin layer 26. The shaping fine uneven structure is a fine unevenness that functions as a shaping for forming fine irregularities on the resin layer of synthetic leather. That is, the fine uneven structure for shaping is fine unevenness corresponding to the fine unevenness on the surface of the resin layer in synthetic leather. The fine uneven structure for shaping can be embossed on the resin layer of the synthetic leather to be embossed to form fine unevenness on the surface thereof.

The gloss value of the synthetic resin layer 26 constituting the release paper is preferably in the range of 81% or more and 95% or less, and 84% or more, from the viewpoint of the surface gloss of the synthetic leather after shaping. More preferred.

As described above, the release paper according to the present invention can be preferably used for producing synthetic leather having a resin layer having fine irregularities formed on its surface. Since the resin layer on the surface of the release paper is excellent in the smoothness of the surface of the release paper, it is possible to form a fine uneven shape on the surface of the synthetic leather without uneven gloss.

[Synthetic leather]
As shown in FIG. 3, the synthetic leather 30 according to the present invention has a base material and a resin layer in which fine unevenness 3 having uniform and fine concave portions and convex portions is formed on the entire surface of one surface of the base material. It is characterized by having and. As a result, a glossy feeling with no surface unevenness can be obtained.

Hereinafter, the components of the synthetic leather 30 will be described in order.

(Base material)
The base material 32 constitutes synthetic leather, and a resin layer is provided on one surface thereof. The base material is not particularly limited, but a cloth (base cloth) used for known synthetic leather such as a natural cloth, a non-woven fabric, and an artificial cloth can be appropriately selected and used. Further, the base material may be a resin sheet other than cloth or a structure coated with the resin sheet. Examples of the resin material constituting such a resin sheet include vinyl chloride, urethane resin, unsaturated polyester resin, acrylic-urethane resin, acrylic acid ester resin, acrylamide resin, nitrocellulose resin, polystyrene resin, alkyd resin, and phenol resin. be able to.

When the base material 32 is in the form of a sheet, the thickness can be appropriately set according to the intended use of the synthetic leather. For example, the lower limit is preferably 100 μm or more from the viewpoint of durability, tactile sensation, and the like. , 500 μm or more is more preferable. The upper limit is preferably 20 mm or less, more preferably 10 mm or less, from the viewpoint of handleability and the like.

(Resin layer)
The resin layer 34 constitutes a synthetic leather together with the above-mentioned base material, and is formed on one surface of the base material. Fine irregularities are formed on the surface of the resin layer. The fine unevenness is a fine structure formed to give an optical interference pattern or the like like a hologram to synthetic leather.

The resin layer 34 is mainly composed of a resin material. Examples of the resin material include thermoplastic resins, thermosetting resins, radiation curable resins, and the like as resin materials for synthetic leather. Specifically, a vinyl chloride resin, a urethane resin, or the like can be preferably used.

The resin layer 34 may optionally contain one or more selected from plasticizers, foaming agents, stabilizers, colorants and the like.

The color of the resin layer 34 is not particularly limited, and a desired color such as red or black can be obtained by using a colorant. Above all, it is desirable to color the resin layer black from the viewpoint of reducing the reflectance of visible light in the entire wavelength range. The colorant may be a pigment or a dye, and is not particularly limited. However, from the viewpoint of coloring even the tips of fine irregularities, a pigment having a large particle size and which may not penetrate to the tips of fine irregularities is used. It is more preferable to use a dye that does not have such a possibility.

The thickness of the resin layer 34 can be appropriately changed depending on the intended use of the synthetic leather. The lower limit of the thickness of the resin layer is preferably 10 μm, more preferably 30 μm from the viewpoint of durability. Similarly, the upper limit is preferably 200 μm, more preferably 150 μm, in order not to impair the texture of the synthetic leather. The thickness of the resin layer is preferably determined as appropriate in relation to the fine unevenness and the gloss value.

The resin layer 34 may be formed by being directly applied onto the base material, or the base material and the resin layer may be bonded to each other via an adhesive layer or the like.

As described above, the synthetic leather according to the present invention comprises a base material and a resin layer having a concave-convex shape having uniform and fine concave portions and convex portions on the entire surface of one surface of the base material. Therefore, a glossy feeling without surface unevenness can be obtained, and it is possible to have a fine concave portion 38 and a convex portion 36 such as an optical interference pattern.

[Manufacturing method of excipient sheet]
The method for producing a release paper according to the present invention is a method for producing a release paper for forming fine irregularities on the resin layer of synthetic leather.

Specifically, as shown in FIG. 4, a step of preparing the original plate 50 on which the plate surface 52 having the uneven structure corresponding to the fine unevenness formed in the resin layer of the synthetic leather is formed, the paper base material, and the paper base material. A surface to be smoothed by a step of preparing a laminated sheet having a smoothing layer formed on the surface of the sheet and a synthetic resin layer formed on the smoothing layer, and a process using a mirror roll 44 on the surface of the synthetic resin layer. A step of superimposing the smoothing surface of the laminated sheet and the plate surface 52 of the original plate 50 to form a fine uneven structure of the plate surface on the surface of the resin layer, and a step of peeling the original plate from the laminated sheet. , Equipped with.

(Preparation of original version)
First, the original plate 50 on which the plate surface 52 having the fine unevenness structure corresponding to the fine unevenness formed on the resin layer of the synthetic leather is formed is prepared. As the original plate 50, a plate having a plate surface 52 is used. The printing plate 52 is formed with a fine uneven structure corresponding to the fine unevenness formed on the surface of the synthetic leather. In other words, by using the release paper produced by this method, it is possible to produce synthetic leather having fine irregularities corresponding to the uneven structure of the plate surface 52. The original plate 50 is particularly strong as long as it has the strength to form a fine uneven structure for shaping on the release paper and further has the strength to withstand the temperature conditions, pressure conditions, etc. of each step in the forming process. Not limited. As the original plate 50, for example, a stainless steel plate can be used.

The means for forming the uneven structure on the plate surface of the original plate is not particularly limited, but for example, the uneven structure is formed on the original plate by using means such as electrolytic plating, electroless plating, anodic oxidation treatment, and etching on the material to be the original plate. be able to.

(Preparation of laminated sheet)
Laminated sheets are prepared. This laminated sheet is a sheet including a paper base material, a smoothing layer formed on the paper base material, and a synthetic resin layer formed on the smoothing layer and having a shape formed by a plate surface. be. The synthetic resin 46 is extruded from the extruder 40 and laminated on the smoothing layer to prepare a laminated sheet.

(Step of forming smoothing surface)
A smoothed surface is formed on the surface of the synthetic resin layer of the laminated sheet by processing with a mirror surface roll 44. That is, by pressing this laminated sheet between the pressing roll 42 and the mirror surface roll 44 located directly under the extruder 40 and laminating the synthetic resin layer on the surface of the smoothing layer of the paper base material, the smoothed surface is processed. Can be formed.
The mirror surface roll 44 used at that time refers to a mirror-type or semi-mirror-type roll in which the roll is chrome-plated and then wet blasted or dry-lasted. Further, the mirror surface roll 44 also includes an ultrafine matte roll as long as the surface of the roll is smoother than the surface of the paper base material. By using this mirror surface roll 44, the smoothness of the synthetic resin layer can be improved.

(Shaping process)
Next, the synthetic resin layer of the laminated sheet 4 and the plate surface of the original plate are overlapped and pressed between the pressing roll 54 and the original plate 50 to form an uneven structure of the plate surface on the surface of the synthetic resin layer. At this time, the original plate is laminated on the laminated sheet or the laminated sheet is laminated on the original plate so that the resin layer of the laminated sheet and at least a part of the plate surface of the original plate are in contact with each other. As a result, the resin layer of the laminated sheet is formed with fine irregularities formed on the plate surface of the original plate, and the fine irregularities for shaping are formed on the surface of the resin layer to form a release paper. This shaping fine uneven structure is an inverted shape of the fine unevenness of the plate surface. As the shaping treatment, the shaping means can be appropriately adopted in consideration of the material of the synthetic resin layer and the like. The original plate having a plate surface can be in the shape of a cylinder (roll) or a plate.

(Peeling process)
Next, the original plate is peeled off from the laminated sheet. By this peeling step, it is possible to obtain a laminated sheet in which fine irregularities for shaping are formed on the synthetic resin layer, that is, a paper pattern.

Each step in each of the above-mentioned methods for producing a paper pattern can appropriately include a heating step, a cooling step, a drying step, and the like, if necessary. Further, the method for producing the release paper according to the present invention is not limited to the above-mentioned production method.

[Manufacturing method of synthetic leather]
The method for producing synthetic leather is a step of preparing a resin sheet for synthetic leather having a base material and a resin layer provided on at least one surface of the base material, and a separation for forming fine irregularities on the resin layer. The process of preparing the pattern, the process of superimposing the resin layer of the prepared resin sheet for synthetic leather and the synthetic resin layer of the prepared release paper, and the process of superimposing the prepared release paper from the resin sheet for synthetic leather. It is provided with a step of peeling off and forming fine irregularities on the surface of the resin layer of the synthetic leather resin sheet.

First, a resin sheet for synthetic leather and a paper pattern are prepared. In the resin sheet for synthetic leather, a resin layer is formed on a base material. The resin layer is a resin layer before fine irregularities are provided.
Next, the resin layer of the prepared synthetic leather resin sheet and the prepared synthetic resin layer of the release paper are superposed.
Then, the separated paper patterns after being superposed are peeled off from the synthetic leather resin sheet to form fine irregularities on the surface of the resin layer of the synthetic leather resin sheet. That is, when the pattern of the fine uneven structure for shaping of the release paper is shaped on the resin layer, the fine unevenness in which the pattern of the fine uneven structure for shaping is inverted is formed on the surface of the resin layer.

A process for shaping the resin layer is performed in a state where the release paper having the fine uneven structure for shaping is superposed on the resin layer. The treatment is not particularly limited, and the treatment can be performed in consideration of the material of the resin layer and the like. For example, heat embossing treatment that applies heat, chill roll embossing treatment that pressurizes heat-softened resin with a cooled roll, treatment that cures with ultraviolet rays to cure the shaped shape, and curing with an electron beam to form the shaped shape. Examples thereof include a treatment for curing.
Above all, in the case of heat embossing treatment in which heat is applied, unevenness due to the texture of the paper can be smoothed, which is preferable.
Further, depending on the material of the resin layer, for example, when a polyvinyl resin is used, a paste coating method can be used, and when a urethane resin is used, a dry treatment can be used. The conditions such as the temperature and pressure of the treatment are not particularly limited, and can be appropriately set according to the treatment to be adopted and the type of resin contained in the resin layer.

As shown in FIG. 5, by peeling off the paper pattern, it is possible to obtain synthetic leather in which fine irregularities 3 are formed on the surface of the resin layer. The conditions such as the peeling speed of the release paper and the temperature at the time of peeling, and the peeling means are not particularly limited.

The present invention will be described in more detail with reference to Examples.

(Making a paper pattern)
Cast coated paper (basis weight 164 g / m ² , cast coat layer 10 μm to 40 μm) was prepared as the paper substrate on which the clay coat layer was formed.
On this cast coat layer, as a synthetic resin layer, polypropylene resin, blended resin of 80% by mass and polyethylene resin, and 20% by mass (manufactured by Sun Aroma Co., Ltd.) was applied from the first extruder of the coextruder at 310 ° C. Further, a homopolypropylene resin (manufactured by Sun Aroma Co., Ltd.) was extruded on the homopolypropylene resin (manufactured by Sun Aroma Co., Ltd.) from the second extruder of the coextruder at 305 ° C. and a line speed of 80 m / min to obtain a laminated sheet via an aqueous anchor coating agent. When the blend resin of the polypropylene resin and the polyethylene resin and the homopolypropylene resin were co-extruded, the extrusion unevenness was less than that when the single-layer polypropylene resin was extruded, and the extrusion coating could be performed smoothly.
Immediately after that, the surface of the laminated sheet was extruded and coated with a mirror surface roll to smooth the surface of the synthetic resin layer having a thickness of 35 μm to obtain a smoothed surface.
The layer structure is a layer structure, cast coated paper (basis weight 164 g / m ² ) / anchor coat layer (1 μm) / blend resin layer (17 μm) / homopolypropylene resin layer (18 μm) (smoothing surface). .. The arithmetic average roughness Ra of the smoothed surface was measured with a shape analysis laser microscope (VK-8710 manufactured by KEYENCE CORPORATION) and found to be 0.08 μm.
Subsequently, as an original plate for shaping the fine concavo-convex structure, a laminated sheet is guided between an embossed roll on which a 10 μm hologram is tuned and a pressing roll made of a resin flat troll having a smooth surface. Then, a fine concavo-convex structure was formed on the synthetic resin layer by thermal pressure embossing, and a release paper having a fine concavo-convex structure formed on the surface of the resin layer was obtained. As shown in FIG. 6, the release paper 20 was pressed between the pressing roll 54 and the original plate 50 to form a pattern. As a result, since the hardness of the coat layer (smoothing layer 24) of the cast coated paper is high, it is not easily affected by the texture of the paper base material 22 constituting the release paper 20, and the synthetic resin 26 has a uniform and fine uneven shape. I was able to mold the entire surface.

(Making synthetic leather)
A polyurethane composition for a resin layer of synthetic leather was applied onto the resin layer of the obtained release paper by a bar coating method to form a composition coating layer. The composition is polyurethane (product name: Resamine NE-8811, manufactured by Dainichiseika Kogyo Co., Ltd.), 5 parts by mass, colorant (product name: Seika Seven NET-5794 (PM) black, manufactured by Dainichiseika Kogyo Co., Ltd.). ) 1 part by mass. A solvent may be used if necessary.
Next, the paper pattern provided with the composition coating layer was heated at 80 ° C. for 3 minutes at a line speed of 10 m / min and a pressure of 25 N. After drying, a cloth (wet base, manufactured by Kinki Vinyl Co., Ltd.) was attached to the composition coating layer on the release paper using an adhesive (product name: Resamine NE-8811, manufactured by Dainichiseika Kogyo Co., Ltd.). Then, the adhesive was dried and aged, and then the release paper was peeled off from the composition coating layer to obtain synthetic leather.
The obtained synthetic leather was visually observed from the resin layer side. As a result, when the patterning is performed with the release paper and the synthetic leather resin overlapped, the transfer unevenness can be eliminated, so that the surface of the synthetic resin layer of the release paper is uniform, and the produced synthetic leather resin There was no uneven gloss on the surface, and a uniform fine uneven shape was generated.

(Comparison example)
Instead of the paper base material on which the clay coat layer of the examples was formed, the synthetic resin layer was formed directly on the high- ^{quality paper (basis weight 125 g / m 2) on which the clay coat layer was not formed, and similarly, the synthetic resin layer was formed.} The surface was smoothed and prepared in the same manner as in Examples to prepare a release paper. As shown in FIG. 7, the release paper 20'was pressed between the pressing roll 54 and the original plate 50 to form a pattern. As a result, since the smoothing layer constituting the release paper 20'of the comparative example is not formed, the synthetic resin layer 26 is affected by the texture of the paper base material 22, and the fine uneven structure for shaping is partially formed. Non-transferred portions (transfer unevenness) were generated, and as a result, a release paper 20'with a non-uniformly shaped surface was obtained. The arithmetic mean roughness Ra of the synthetic resin layer before shaping was 0.15 μm.
Using this paper pattern, a synthetic leather having fine irregularities was produced in the same manner as in the examples.
The obtained synthetic leather was visually observed from the resin layer side. As a result, uneven gloss was generated on the surface of the resin of the produced synthetic leather.

(Measurement of gross value)
Examples of the obtained release paper (the surface of the synthetic resin layer before and after shaping) were measured using "IG-320 (60 ° reflection)" manufactured by HORIBA, Ltd. As a result, the gloss value of the release paper before shaping was 85%, the gloss value of the release paper after shaping was 23%, and the gloss value of the synthetic leather after shaping was 19%. rice field. In the synthetic leather of the example, there was no uneven gloss, and a uniform and fine uneven shape was imparted.

3 Fine unevenness 4 Laminated sheet 10 Smoothing surface 12 Shaped pattern 14 Fine convex part structure for shaping 16 Fine concave part structure for shaping 20 Release paper pattern 20'Release paper pattern (comparative example)
22 Paper base material 24 Smoothing layer 26 Synthetic resin layer 28 Anchor coat layer 30 Synthetic leather 32 Base material 34 Resin layer 36 Convex part 38 Concave part 40 Extruder 42 Pressing roll 44 Mirror surface roll 46 Synthetic resin 50 Original plate 52 Plate surface 54 Pressing roll

Claims (3)

A paper pattern for forming fine irregularities on the resin layer of synthetic leather.
Paper substrate and
A smoothing layer formed on one surface of the paper substrate and smoothing the surface,
A synthetic resin layer formed on the smoothing layer is provided.
The smoothing layer is composed of a clay coat layer having an arithmetic mean surface roughness Ra of 0.1 μm or less.
The synthetic resin layer is a thermoplastic resin obtained by mixing one or more of polymethylpentene, polypropylene, and polyethylene.
The entire final surface of the synthetic resin layer constituting the paper pattern is a smoothing surface.
Moreover, the gloss value of the surface is 81% or more and 95% or less.
The synthetic resin layer is formed with a shaping mold for forming the fine irregularities on the resin layer .
An anchor coat layer is formed between the smoothing layer and the synthetic resin layer.
The anchor coat layer, polypropylene resin emulsion or dispersion, or modified polyolefin resin of the emulsion or dispersion of an anchor coating agent der release paper, wherein Rukoto. The paper pattern according to claim 1, wherein the synthetic resin layer has a layer thickness of 20 μm or more and 100 μm or less. A method for producing a paper pattern for forming fine irregularities on the resin layer of synthetic leather.
A step of preparing an original plate on which a plate surface having a concavo-convex structure corresponding to the fine concavo-convex formed on the resin layer is formed, and
A step of laminating a paper base material, a smoothing layer formed on the paper base material, and a synthetic resin layer extruded from an extruder on the smoothing layer to prepare a laminated sheet.
A step of forming a smoothed surface by processing the entire surface of the synthetic resin layer with a mirror surface roll, and
A step of superimposing the smoothed surface of the laminated sheet and the plate surface of the original plate to form a fine concavo-convex structure of the plate surface on the surface of the resin layer.
A step of peeling the original plate from the laminated sheet is provided.
The smoothing layer is composed of a clay coat layer having an arithmetic mean surface roughness Ra of 0.1 μm or less.
The synthetic resin layer is a thermoplastic resin obtained by mixing one or more of polymethylpentene, polypropylene, and polyethylene.
A method for producing a paper pattern, wherein the smoothed surface has a gloss value of 81% or more and 95% or less on the surface of the synthetic resin layer.

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