JPWO2015136921A1 - Nubuck-like sheet and method for producing the same - Google Patents

Abstract

The nubuck-like sheet (1) is formed by laminating a surface layer (3) made of a polyurethane resin on a fibrous base material (2). On the front surface (4) of the nubuck-like sheet, the height difference (A) between the convex portion (8) and the concave portion (9) is 20 to 150 μm, and the interval (B) between adjacent convex portion vertices is 20 to 20 μm. It has fine irregularities that are 150 μm. Moreover, the surface dynamic friction coefficient of the front surface (4) is 0.20 to 0.50.

Description

  The present invention relates to a sheet-like material having a nubuck-like appearance and a method for producing the same.

  Conventionally, a sheet-like material having an appearance imitating a nubuck of natural leather has been used for various applications such as clothing, bags, shoes, interior materials, and vehicle interior materials. As the nubuck-like sheet-like material, those produced by a method called a wet method or a dry method are mainly used.

  In the wet method, a fiber base material is coated or impregnated with a polyurethane resin solvent (organic solvent) solution, which is immersed in a liquid containing a polyurethane resin non-solvent, and the solvent in the polyurethane resin solution becomes a non-solvent. Transition. Thereby, a polyurethane resin is solidified and a porous layer is formed. Then, the front side is ground to give a nap-like appearance. The sheet-like material obtained by this wet method has a delicate nap-like appearance, a moist feeling and a soft texture, and is similar to a natural leather nubuck. However, it is difficult to obtain wear resistance that is fragile to external force and that is satisfactory as a field requiring high durability, for example, interior materials and vehicle interior materials.

  On the other hand, in the dry method, a fibrous base material is coated or impregnated with a solvent solution or aqueous dispersion of a polyurethane resin, dried, and then the front surface is ground to give a nap-like appearance. At first glance, the sheet-like material obtained by this dry method has a nap-like appearance. However, it is rough and dry, has a hard texture, and is far from natural leather nubuck. Moreover, although it is excellent in abrasion resistance than the sheet-like material obtained by a wet method, it cannot be said that it is enough.

  The above two methods are the mainstream for producing a nubuck-like sheet, but as one form of the dry method, a laminate in which a skin layer made of a polyurethane resin produced on a release paper has been proposed. For example, in Patent Document 1, a middle layer made of polyurethane resin is prepared on a skin layer made of polyurethane resin prepared on a release paper, and this is bonded to a fibrous base material with an adhesive, and then the release paper is peeled off Thus, one having a nubuck design has been proposed. According to this method, a nubuck-like design can be obtained, but the tactile sensation (particularly the slime feeling) is not reproduced. In view of this problem, Patent Document 2 discloses that a skin layer made of a polyurethane resin prepared on a release paper is bonded to a fibrous base material with an adhesive, and then the release paper is peeled off. Proposals have been made to grind the surface to give it a raised appearance. According to this method, although a nubuck-like slime feeling can be obtained, the front surface is ground, so that it does not have wear resistance.

  Thus, the present situation is that the nubuck-like sheet-like material excellent in both nubuck-like sensory characteristics and wear resistance has not been obtained.

Japanese Patent No. 3078208 Japanese Patent No. 30603399

  The present invention has been made in view of such a current situation, and provides a nubuck-like sheet-like material having both a tactile sensation satisfactory as a nubuck-like sheet-like material and wear resistance, and a method for producing the same. .

  First, the present embodiment is a nubuck-like sheet-like product obtained by laminating a surface layer made of polyurethane resin on a fibrous base material, and a difference in height between a convex portion and a concave portion on the front surface of the nubuck-like sheet-like material Is a nubuck-like sheet-like material having an unevenness of 20 to 150 μm, an interval between adjacent convex vertices of 20 to 150 μm, and a surface dynamic friction coefficient of 0.20 to 0.50 on the front surface.

Second, the present embodiment is a method for producing the nubuck-like sheet-like material,
(1) A step of applying a surface layer resin liquid on a releasable substrate to form a surface layer,
(2) A step of bonding the surface layer and the fibrous base material, and
(3) a step of peeling the releasable substrate;
Is a method for producing a nubuck-like sheet material.

  According to this embodiment, it is possible to provide a nubuck-like sheet-like material having both a tactile sensation satisfactory as a nubuck-like sheet-like material and wear resistance, and a method for manufacturing the same.

It is a cross-sectional schematic diagram of the nubuck-like sheet-like material which concerns on one Embodiment. It is a cross-sectional schematic diagram of the nubuck-like sheet-like material which concerns on other embodiment. It is a cross-sectional model drawing of the nubuck-like sheet-like material which concerns on other embodiment.

  The nubuck-like sheet material according to the present embodiment is a nubuck-like sheet material obtained by laminating a surface layer made of a polyurethane resin on a fibrous base material, and has fine irregularities on the front surface of the nubuck-like sheet material. And the surface dynamic friction coefficient of the front surface is 0.20 to 0.50. Here, a fine unevenness | corrugation means the unevenness | corrugation whose height difference of a convex part and a recessed part is 20-150 micrometers, and the space | interval of adjacent convex part vertex is 20-150 micrometers.

  FIG. 1 schematically shows a cross-sectional structure of a nubuck-like sheet 1 according to an embodiment. In this sheet-like material 1, the surface layer 3 is laminated on one side of the fibrous base material 2, the surface of the surface layer 3 is the front surface 4, and the front surface 4 has a fine structure composed of convex portions 8 and concave portions 9. Irregularities are provided. Moreover, in this example, the surface layer 3 is laminated | stacked on the fibrous base material 2 via the contact bonding layer 5, Therefore, the contact bonding layer 5 and the surface layer 3 are laminated | stacked in this order on one surface of the fibrous base material 2. ing.

  FIG. 2 schematically shows a cross-sectional structure of a nubuck-like sheet 10 according to another embodiment. In this sheet-like material 10, an anchor coat layer 6 is provided below the surface layer 3, and a protective layer 7 is provided on the surface layer 3. Therefore, in the example of FIG. 2, the adhesive layer 5, the anchor coat layer 6, the surface layer 3, and the protective layer 7 are laminated in this order on one surface of the fibrous base material 2, and the surface of the protective layer 7 is fine. The front surface 4 has unevenness.

  The height difference between the convex portion and the concave portion on the front surface is a height difference between an arbitrary convex portion and the concave portion closest to the convex portion, and is obtained from observation in a vertical cross section as follows. That is, the vertical cross section of the nubuck-like sheet-like material is observed with a microscope (manufactured by Keyence Corporation, Digital HF microscope VH-8000). The height difference (see A in FIG. 1) is measured, and the average value is defined as the height difference between the convex portion and the concave portion.

  Further, the interval between adjacent convex vertices on the front surface is the distance between the vertices between an arbitrary convex portion and the convex portion closest to the convex portion, and is obtained from observation in a vertical section as follows. That is, the vertical cross section of the nubuck-like sheet-like material is observed with a microscope (Keyence Corporation, Digital HF microscope VH-8000), and the protrusions at any ten locations and the protrusions closest to the protrusions are between the vertices. The horizontal distance (the distance between the vertices in the direction perpendicular to the thickness direction of the sheet-like material, see B in FIG. 1) is measured, and the average value is defined as the interval between the adjacent vertices.

  According to this embodiment, the height difference between the convex portion and the concave portion on the front surface is 20 to 150 μm, and the interval between the adjacent convex vertexes is 20 to 150 μm. As a result, it is possible to obtain the same appearance and tactile sensation as the genuine leather nubuck, specifically, a slimy feeling and a fluffy feeling. Specifically, when the height difference between the convex portion and the concave portion is 20 μm or more, the height difference can be recognized as fuzz, and a more appropriate frictional resistance value can be obtained. Therefore, the same tactile feeling, slime feeling and fluffy feeling as those of genuine leather nubuck can be obtained. If the height difference between the convex portion and the concave portion is 150 μm or less, the frictional resistance value will not be too high, and the wear resistance can be prevented from being impaired. Moreover, if the space | interval of adjacent convex part vertex is 20 micrometers or more, a frictional resistance value will not become high too much and it can prevent that abrasion resistance is impaired. If the distance between adjacent apexes of protrusions is 150 μm or less, a moderate frictional resistance value can be obtained. The height difference between the convex portion and the concave portion is more preferably 50 to 100 μm. More preferably, the interval between adjacent convex vertexes is 80 to 120 μm.

  According to this embodiment, since the surface dynamic friction coefficient of the front surface is 0.20 to 0.50, the surface dynamic friction coefficient is the same as that of genuine leather nubuck. Therefore, a moderate surface resistance can be felt when touching the surface, and a touch feeling, particularly a slimy feeling, similar to that of genuine leather nubuck can be obtained. More specifically, if the surface dynamic friction coefficient is 0.20 or more, the surface does not feel slippery and a slimy feeling similar to that of genuine leather nubuck is obtained. If the surface dynamic friction coefficient is 0.50 or less, the surface will not have a strong tactile feeling or a strong tactile feeling, and a slimy feeling similar to that of genuine leather nubuck will be obtained. The surface dynamic friction coefficient of the front surface is more preferably 0.20 to 0.40.

  The surface dynamic friction coefficient of the front surface can be measured by the following method. That is, a nubuck-like sheet-like material cut into a 20 cm square was used as a test piece, and a surface dynamic friction coefficient measuring device: KES-SE (manufactured by Kato Tech Co., Ltd.) was used. Temperature 22 ± 2 ° C., humidity 65 ± 5% Under the RH environment, the average surface dynamic friction coefficient (MIU) of the front side is measured. The measurement conditions are a piano wire sensor 10 mm square as a friction element, a sample moving speed of 1 mm / sec, a measurement direction is WARP (longitudinal direction), three arbitrary points are measured, and the average value is a surface dynamic friction coefficient.

  Examples of the fibrous base material include fabrics such as knitted fabric, woven fabric, and non-woven fabric, and natural leather (leather floor). The cloth is coated or impregnated with a conventionally known solvent-based or solvent-free (including water-based) polymer compound (preferably a polyurethane resin or a copolymer thereof, or a mixture mainly composed of a polyurethane resin). In addition, a dry solidified or wet solidified one can be used. In addition, the material of the fibers constituting the fibrous base material is not particularly limited, and examples thereof include conventionally known fibers such as natural fibers, regenerated fibers, semi-synthetic fibers, and synthetic fibers. It may be combined. Of these, synthetic fibers are preferable, polyester fibers are more preferable, and polyethylene terephthalate is particularly preferable from the viewpoints of heat resistance and light resistance. The thickness of the fibrous base material is preferably 0.3 to 1.5 mm, more preferably 0.5 to 1.0 mm, from the viewpoint of wear resistance and texture. The fibrous base material may be colored with a dye or a pigment.

  The nubuck-like sheet material according to the present embodiment is obtained by laminating a surface layer made of a polyurethane resin as a resin layer on the above-described fibrous base material.

  As the polyurethane resin used for forming the surface layer, a conventionally known polyurethane resin can be used, but from the viewpoint of wear resistance and tactile sensation (particularly slime feeling), a polycarbonate polyurethane resin and a polyether polyurethane resin are blended. Is preferred. By using a polycarbonate-based polyurethane resin, wear resistance is improved. By using the polyether-based polyurethane resin, tactile sensation, particularly slimy feeling, is improved.

  The blending ratio (mass ratio) of the polycarbonate-based polyurethane resin and the polyether-based polyurethane resin is preferably polycarbonate-based polyurethane resin: polyether-based polyurethane resin = 80: 20 to 20:80. In order to achieve both, it is more preferably 50:50 to 30:70. When the ratio of the polycarbonate-based polyurethane resin is 20% by mass or more, it is possible to prevent the heat resistance, moist heat resistance, and light resistance from decreasing. Moreover, when the ratio of the polyether-based polyurethane resin is 20% by mass or more, it is possible to enhance the effect of improving the touch feeling and the texture. In addition, content (solid content conversion) of the polyurethane resin which occupies for the whole surface layer is not specifically limited, 55-93 mass% may be sufficient, and 70-85 mass% may be sufficient.

  A smoothing agent may be added to the surface layer from the viewpoint of improving the wear resistance. The content of the smoothing agent (in terms of solid content) is preferably 1 to 15% by mass, more preferably 3 to 10% by mass with respect to the entire surface layer. When the content is 1% by mass or more, the effect of improving the wear resistance can be enhanced. Moreover, by being 15 mass% or less, it can prevent bleed | breeding or impairing surface quality due to conspicuous scratches.

  Examples of the smoothing agent include silicone compounds, and examples thereof include dimethyl silicone and acrylic-modified silicone. These can be used alone or in combination of two or more. Of these, dimethyl silicone is preferred from the viewpoint of versatility.

  A tactile sensation improver may be added to the surface layer from the viewpoint of imparting a slimy feeling. The content of the tactile sensation improver (in terms of solid content) is preferably 1 to 6% by mass, more preferably 2 to 5% by mass with respect to the entire surface layer. If content is 1 mass% or more, desired slimy feeling will be obtained. Moreover, if it is 6 mass% or less, it can prevent that the whitening phenomenon by abrasion arises.

  Examples of the tactile sensation improver include wax. Examples thereof include paraffin wax, polyethylene wax, polypropylene wax, carbana wax, lanolin wax, and the like, and these can be used alone or in combination. Among these, paraffin wax is preferable because it has a high effect of giving a slimy feeling.

  It is preferable to add a pigment to the surface layer for coloring. The pigment content (in terms of solid content) is preferably 5 to 20% by mass, more preferably 10 to 15% by mass, based on the entire surface layer. When the content is 5% by mass or more, not only the desired color can be colored, but also the yellowing of the resin can be concealed, so that the light resistance, heat resistance, and moist heat resistance can be improved. When the content is 20% by mass or less, the film strength of the surface layer is not impaired, and thus the wear resistance is excellent.

  The 100% modulus of the surface layer is 1 to 5 MPa from the point that fine irregularities are easily adapted to the hand, so that it feels like fluff and can obtain a touch (particularly, fluff feel) similar to genuine leather nubuck. It is preferable, More preferably, it is 2-3 MPa. When the 100% modulus is 1 MPa or more, the strength of the resulting nubuck-like sheet is not impaired. Moreover, if it is 5 Mpa or less, it can prevent that a fine unevenness | corrugation becomes coarse and can improve a tactile feeling.

Here, the 100% modulus value of the surface layer is calculated as follows. That is, the composition for forming the surface layer was applied onto a flat release paper (EU130TPD, manufactured by Lintec Corporation) using a bar coater so that the thickness of the cured film was 100 μm, and then dried at 80 ° C. with a dryer. After heat treatment for 5 minutes, a cured film is formed by aging treatment for 1 day under conditions of room temperature 20 ± 2 ° C. and humidity 65 ± 5% RH. Three test pieces each having a width of 30 mm and a length of 100 mm were taken from the cured film, and subjected to a tensile tester (Autograph AG-X, stock) under the conditions of room temperature 20 ± 2 ° C. and humidity 65 ± 5% RH. It is attached to a gripping tool (manufactured by Shimadzu Corporation) with a gripping width of 30 mm and a gripping interval of 50 mm, pulled at a pulling speed of 100 m / min, and the load when the stroke distance becomes 50 mm is measured. The 100% modulus value is calculated by the following formula, and the average value of the three points is taken as the 100% modulus value of the surface layer.
100% modulus value (MPa) = Load (N) / Cross-section area (mm ² ) when the stroke distance becomes 50 mm

  The thickness of the surface layer is preferably 20 to 200 μm, more preferably 50 to 150 μm. When the thickness is 20 μm or more, the wear resistance of the nubuck-like sheet-like material obtained can be improved. When the thickness is 200 μm or less, there is no possibility that the texture of the nubuck-like sheet obtained is coarse.

  Here, the thickness of the surface layer is calculated as follows. That is, a value obtained by observing a vertical section of a nubuck-like sheet with a microscope (manufactured by Keyence Corporation, Digital HF microscope VH-8000) and measuring the height difference between the top of the convex portion and the lowermost portion of the surface layer at any 10 locations. And the average value of the values obtained by measuring the height difference between the bottom of the recess and the lowermost part of the surface layer at any 10 locations is defined as the thickness of the surface layer.

  In the nubuck-like sheet material according to the present embodiment, a protective layer and / or an anchor coat layer may be provided in order to improve wear resistance. As described above, the protective layer is laminated on the upper layer of the surface layer, and the anchor coat layer is laminated on the lower layer of the surface layer. In addition, it is preferable that a protective layer and / or an anchor-coat layer are formed from a polyurethane resin similarly to a surface layer from a viewpoint of an adhesive improvement.

  As the polyurethane resin for forming the protective layer and the anchor coat layer, the same polyurethane resin as that for the surface layer can be used. A protective layer is located in the outermost layer which forms the front side of a nubuck-like sheet-like material, and a person touches directly. Therefore, for the protective layer, it is preferable to use a polycarbonate-based polyurethane resin from the viewpoint of wear resistance, and further, a tactile sensation improver from the viewpoint of slime feeling and a smoothing agent from the viewpoint of wear resistance may be added. preferable.

  The thickness of the protective layer is preferably 2 to 10 μm, more preferably 2 to 5 μm, from the viewpoints of wear resistance and touch. In addition, the thickness of the anchor coat layer is preferably 10 to 30 μm, more preferably 15 to 20 μm from the viewpoint of texture. The total thickness of the protective layer, the surface layer, and the anchor coat layer is preferably 32 to 240 μm, more preferably 60 to 120 μm, from the viewpoint of wear resistance and texture.

  In the nubuck-like sheet material according to the present embodiment, an adhesive layer may be provided between the surface layer and the fibrous base material. Although the surface layer may be directly laminated on the fibrous base material, excessive penetration of the polyurethane resin constituting the surface layer into the fibrous base material, which may occur when directly laminated, is suppressed by using an adhesive layer. This makes it easier to obtain the same feel and texture as a genuine leather nubuck. Although it does not specifically limit as an adhesive agent used as a contact bonding layer, A polyurethane resin is used preferably and the resin similar to resin used for a surface layer can be used.

The number of convex portions per unit area (1 cm ² ) of fine irregularities on the front surface of the nubuck-like sheet is preferably 4,000 to 80,000, more preferably 20,000 to 50, 000, more preferably 20,000 to 30,000. If the number of convex parts per unit area is 4,000 to 80,000, it is easy to obtain a tactile sensation similar to genuine leather nubuck, that is, a slimy feeling and a fluffy feeling.

Here, the number of convex portions per unit area (1 cm ² ) of fine irregularities on the front surface is calculated as follows. That is, the front side of the nubuck-like sheet-like material was observed at a magnification of 500 times using a microscope (manufactured by Keyence Corporation, Digital HF microscope VH-8000), and the number of protrusions in the vertical 500 μm and horizontal 250 μm (X ) By visual inspection. The number of convex portions per unit area (1 cm ² ) is calculated from the counted number (X) of convex portions using the following formula.
Conversion formula: number of convex portions per unit area = number of convex portions counted (X) × 10 ² /0.125

  Another uneven pattern may be superimposed on the front surface of the nubuck-like sheet material as long as the effect of the present embodiment is not impaired. Another concavo-convex pattern refers to a concavo-convex pattern consisting of concave and convex portions having a large height (height difference) and width (interval) compared to the fine concave and convex portions and concave portions described above. Examples include wrinkle patterns and geometric patterns. Therefore, in a certain embodiment, an uneven pattern larger than the fine unevenness is provided on the front surface of the nubuck-like sheet material, and the fine unevenness is formed on the large uneven pattern using the large uneven pattern as a reference contour. May be formed. By superimposing such a large uneven pattern, it is possible to provide a complicated design having genuine leather nubuck and other patterns. In addition, tactile sensation, slime feeling and fluffy feeling can be brought closer to genuine leather nubuck. In addition, as can be understood from this, the fine irregularities described above are denser than a general natural leather texture pattern, and can be said to be relatively uniform irregularities.

  FIG. 3 schematically shows a cross-sectional structure of the nubuck-like sheet-like material 11 provided with the other uneven pattern. On the front surface 4 of the sheet-like material 11, a large concavo-convex pattern composed of a large concave portion 12 and a convex portion 13 serving as a reference contour is formed. On the front surface 4 having such a large uneven pattern, fine unevenness composed of the concave portion 9 and the convex portion 8 is provided.

  The interval between the adjacent concave portions of the large concave / convex pattern is the lowest location of the lowest concave portion of any large concave portion and the largest concave portion closest to the concave portion (refers to a portion having a larger height difference than the concave portion of the fine concave / convex portion). And the distance. The difference in height between the concave portion and the convex portion having a large concavo-convex pattern is a difference in height between an arbitrary large concave portion and a large convex portion closest to the concave portion. These are obtained from observation in a vertical section as follows. That is, the vertical section of the nubuck-like sheet-like material is observed with a microscope (manufactured by Keyence Corporation, Digital HF microscope VH-8000). Measure the horizontal distance between them (the distance between the lowest locations in the direction perpendicular to the thickness direction of the sheet-like material, see C in FIG. 3), and measure the range (minimum value and maximum value) between adjacent large recesses. The interval of Further, for adjacent large concave portions and convex portions at arbitrary ten locations, the height difference (see D in FIG. 3) between the bottom of the concave portion and the top of the convex portion is measured, and the average value thereof is calculated between the concave portion and the convex portion. Difference in elevation. Here, the magnification by the microscope when observing a large uneven pattern can be set smaller than the magnification when observing fine unevenness in order to observe a wider range. For example, the magnification for observing fine irregularities is 500 times, whereas the magnification for observing large irregularities can be 50 times.

Next, a method for producing the nubuck-like sheet will be described. The manufacturing method is as follows:
(1) A step of applying a surface layer resin liquid on a releasable substrate to form a surface layer;
(2) a step of bonding the surface layer and the fibrous base material;
(3) peeling the releasable substrate;
Is included.

  As a method of applying the surface layer resin liquid onto the releasable substrate, various conventionally known methods can be adopted and are not particularly limited. For example, the method using apparatuses, such as a reverse roll coater, a spray coater, a roll coater, a knife coater, a comma coater, can be mentioned. Among these, application with a reverse roll coater, knife coater, or comma coater is preferable in that a uniform thin film layer can be formed.

  The releasable base material is not particularly limited, and may be any base material having releasability with respect to the polyurethane resin or a base material subjected to a release treatment. For example, release paper, release treated cloth, water repellent treated cloth, olefin sheet or film made of polyethylene resin or polypropylene resin, fluororesin sheet or film, plastic film with release paper, and the like can be mentioned.

  It is important that the releasable substrate has an uneven pattern. By using a releasable base material having a concavo-convex pattern in which the height difference between the convex part and the concave part is 20 to 170 μm and the distance between adjacent concave parts is 20 to 170 μm, a desired fine concavo-convex pattern can be obtained. It can be applied to the front side of the object. That is, the fine unevenness of the front surface of the nubuck-like sheet is provided by the uneven pattern of the releasable substrate. The releasable substrate may have a large concavo-convex pattern corresponding to the above large concavo-convex pattern as long as the fine concavo-convex pattern is not impaired.

  The coating thickness of the surface layer resin solution may be appropriately set according to the thickness of the surface layer, and is preferably 40 to 400 μm, more preferably 100 to 300 μm. By setting the coating thickness within this range, a surface layer having a thickness of preferably 20 to 200 μm, more preferably 50 to 150 μm is obtained.

  After applying the surface layer resin liquid to the releasable substrate, heat treatment is performed as necessary. The heat treatment is performed to evaporate the solvent in the surface layer resin liquid and dry the resin. Further, when a cross-linking agent that causes a cross-linking reaction by heat treatment or when using a two-component curable resin, the reaction is promoted to form a film having sufficient strength.

  The heat treatment temperature may be 50 to 150 ° C or 60 to 130 ° C. When the heat treatment temperature is 50 ° C. or higher, the heat treatment does not take too much time, and the process load does not become excessive. Moreover, since it can prevent that bridge | crosslinking of resin becomes inadequate, it can prevent that abrasion resistance becomes inferior. When the heat treatment temperature is 150 ° C. or lower, the texture of the synthetic leather can be prevented from becoming coarse and hard. The heat treatment time may be 2 to 20 minutes or 2 to 10 minutes. When the heat treatment time is 2 minutes or longer, it is possible to prevent the resin from being insufficiently crosslinked, and thus it is possible to prevent the wear resistance from being deteriorated. When the heat treatment time is within 20 minutes, the process load is not excessively increased.

  Next, the surface layer and the fibrous base material are bonded together. At the time of bonding, as described above, an adhesive layer may be interposed, or direct lamination may be performed. Preferably, they are bonded through an adhesive layer. When the adhesive layer is provided, the adhesive may be applied to the surface layer and then bonded to the fibrous base material.

  The method for applying the adhesive may be any of various known methods and is not particularly limited. For example, the method using apparatuses, such as a reverse roll coater, a spray coater, a roll coater, a gravure coater, a kiss roll coater, a knife coater, a comma coater, can be mentioned.

  Next, the releasable substrate is peeled from the surface layer. Thus, the nubuck sheet material according to the present embodiment is obtained. However, the method for manufacturing the nubuck sheet material according to the present embodiment is not limited to the above method.

  In addition, when forming an anchor coat layer, after forming a surface layer on a releasable base material, before apply | coating an adhesive agent, the resin liquid for anchor coat layers is apply | coated and formed on a surface layer. On the other hand, when forming the protective layer, the release substrate is peeled from the surface layer, and then the protective layer resin liquid is applied to the front surface of the surface layer. About the method of apply | coating and the heat processing after application | coating, the method similar to formation of a surface layer can be used.

  The coating thickness of the protective layer resin solution may be appropriately set according to the thickness of the protective layer, and may be 5 to 25 μm or 5 to 13 μm. By setting the coating thickness within this range, a protective layer having a thickness of preferably 2 to 10 μm, more preferably 2 to 5 μm is obtained.

  What is necessary is just to set suitably the application | coating thickness of the resin liquid for anchor coat layers according to the thickness of the said anchor coat layer, 50-150 micrometers may be sufficient and 75-100 micrometers may be sufficient. By setting the coating thickness within this range, an anchor coat layer having a thickness of preferably 10 to 30 μm, more preferably 15 to 20 μm is obtained.

  In the case of the nubuck-like sheet according to the present embodiment, the front surface has the above-described irregularities and has a predetermined surface dynamic friction coefficient, so that a nubuck-like tactile sensation can be obtained without grinding the surface of the surface layer. Can do. That is, in the nubuck-like sheet-like material according to the present embodiment, the front surface is not ground, but nevertheless a nubuck-like feel is imparted. Therefore, it is possible to impart satisfactory wear resistance even in a field where high durability is required, while having a satisfactory tactile feel as a nubuck-like sheet-like material.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. “Parts” in the examples are based on mass.

[Example 1]
The surface layer resin solution prepared in accordance with the above prescription 1 was applied to a release paper in a sheet form with a comma coater so that the coating thickness was 200 μm, and heat treated at 100 ° C. for 3 minutes in a dryer. A surface layer of 100 μm was formed. As the release paper, a paper having a fine unevenness pattern having a height difference of 115 μm between the convex and concave portions, an interval between adjacent concave portions of 94 μm, and the number of concave portions of 28,000 / cm ² was used. The mass ratio of the polycarbonate-based polyurethane resin and the polyether-based polyurethane resin of the polyurethane resin forming the surface layer was 32:68, the pigment content (in terms of solid content) was 11% by mass, and the 100% modulus value was 2.5 MPa. .

Next, on the surface layer, urethane polyisocyanate prepolymer (NH230, solid content: 100% by mass, manufactured by DIC Corporation) was applied as an adhesive in a sheet shape with a comma coater so that the coating thickness was 170 μm. In the state in which the urethane polyisocyanate prepolymer has a viscosity, a circular knitted fabric (knitted with a mockrod structure using 150 dtex / 48f polyester multifilament yarn, thickness 0.7 cm, basis weight 260 g / m ² , 70 course / 24 0.5 mm, 33 well / 25.4 mm), and mangled with a load of 5 kg / m ² . The film was aged for 3 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%, and then the release paper was peeled off to obtain a nubuck-like sheet.

In the obtained nubuck-like sheet-like material, the height difference between the convex portion and the concave portion of the front surface is 86 μm, the interval between adjacent convex portions is 102 μm, the number of convex portions is 24,000 pieces / cm ² , and the surface dynamic friction coefficient Was 0.38. Further, the content of the smoothing agent (in terms of solid content) in the surface layer that is the outermost surface of the nubuck-like sheet was 8% by mass, and the content of the tactile sensation improver (in terms of solid content) was 3% by mass.

[Example 2]
A sheet-like material was obtained in the same manner as in Example 1 except that the smoothing agent and the tactile sensation improver were removed from the surface layer resin solution. On the surface layer of the obtained sheet-like material, the protective layer resin solution prepared according to Formula 2 was applied in a sheet shape with a roll coater so that the coating thickness was 10 μm, and 3 times at 100 ° C. with a dryer. A heat treatment was performed for 5 minutes to form a protective layer having a thickness of 4 μm, and a nubuck-like sheet was obtained. In the obtained nubuck-like sheet-like material, the height difference between the convex portion and the concave portion on the front surface is 54 μm, the interval between adjacent convex portions is 98 μm, the number of convex portions is 21,600 / cm ² , and the surface dynamic friction coefficient Was 0.26. Moreover, the content rate of the smoothing agent in the protective layer which is the outermost surface of a nubuck-like sheet-like material was 7 mass%, and the content rate of the touch improvement agent was 3 mass%.

[Example 3]
In Example 1, after the surface layer was formed on the release paper, before applying the adhesive, the anchor coat layer resin solution prepared according to Formula 3 on the surface layer was applied with a comma coater to a coating thickness of 150 μm. The film was applied in the form of a sheet and heat-treated at 100 ° C. for 3 minutes in a dryer to form an anchor coat layer having a thickness of 30 μm. Except that, a nubuck-like sheet was obtained in the same manner as in Example 1. In the obtained nubuck-like sheet-like material, the height difference between the convex portion and the concave portion on the front surface is 84 μm, the interval between adjacent convex portions is 110 μm, the number of convex portions is 24,000 pieces / cm ² , and the surface dynamic friction coefficient Was 0.34. Moreover, the content rate (solid content conversion) of the smoothing agent in the surface layer which is the outermost surface of a nubuck-like sheet-like material was 8 mass%, and the content rate of the touch improvement agent (solid content conversion) was 3 mass%.

[Example 4]
In Example 2, after forming the surface layer on the release paper, before applying the adhesive, an anchor coat layer having a thickness of 30 μm was formed in the same manner as in Example 3. Except that, a nubuck-like sheet was obtained in the same manner as in Example 2. In the obtained nubuck-like sheet-like material, the height difference between the convex portion and the concave portion on the front surface is 55 μm, the interval between adjacent convex portions is 93 μm, the number of convex portions is 21,600 / cm ² , and the surface dynamic friction coefficient Was 0.25. Moreover, the content rate (solid content conversion) of the smoothing agent in the protective layer which is the outermost surface of a nubuck-like sheet-like material was 7 mass%, and the content rate (solid content conversion) of the touch improvement agent was 3 mass%.

[Examples 5 to 11 and Comparative Examples 1 to 4]
A nubuck-like sheet was produced in the same manner as in Example 1 except that a nubuck-like sheet was produced according to Table 4. In addition, the release paper used in Example 11 has the fine unevenness | corrugation of Table 4 on this uneven | corrugated pattern by using the leather uneven | corrugated large uneven | corrugated pattern as a reference outline. In the configuration of the large concavo-convex pattern, the height difference between the concave and convex portions was 235 μm, the interval between the adjacent convex portions was 0.2 to 2 mm, and the number of concave portions was 63 / cm ² .

  For each nubuck-like sheet-like material, the tactile sensation, texture, abrasion resistance, moist heat resistance, heat resistance, and light resistance were evaluated by the following methods, and the results are shown in Table 4.

[Feel]
Sensory evaluation was performed about the tactile sensation of the front side of the test piece, and it was determined according to the following criteria.
A: A feeling of moist and fluffy feeling of nubuck tone B: A feeling of either a moist feeling of fluffy or fluffy feeling of nubuck tone is somewhat lacking C: A feeling of nubuck tone is somewhat lacking D : There is no nubuck-like feel, and it is rough and dry.

[Texture]
Sensory evaluation was performed about the hand-held feeling of the test piece, and it determined in accordance with the following reference | standard.
A: Has a soft and supple texture similar to genuine leather nubuck. B: Has a soft and supple texture similar to genuine leather nubuck, but feels slightly resin and core. C: Soft and supple compared to genuine leather nubuck. The texture is inferior and feels a resin feeling and core. D: Clearly feels different from genuine leather nubuck and feels a strong resin feeling and core.

[Abrasion resistance]
One test piece having a width of 70 mm and a length of 300 mm was taken from each of the vertical and horizontal directions, and a urethane foam having a width of 70 mm, a length of 300 mm, and a thickness of 10 mm was attached to the back surface. With a 4.5mm diameter wire installed in the center of the lower surface of the urethane foam, it is fixed to a flat abrasion tester T-TYPE (manufactured by Daiei Kagaku Seisakusho Co., Ltd.), and a wearer covered with a cotton cloth wires over the wire. A wear test was performed by applying a load of 9.8 N to the friction element so as to reciprocate in parallel. The friction element was reciprocated 3000 times at a speed of 60 reciprocations per minute between 140 mm on the surface of the test piece. The surface condition of the test piece after the abrasion test was observed and judged according to the following criteria.
5: No change in appearance (no cracks or tears)
4: Slight wear is observed but not noticeable 3: Wear is clearly observed and the fibrous base material is exposed (cracks are observed)
2: Exposed fiber substrate is slightly exposed 1: Exposed fiber substrate is exposed (breaking is observed)

[Moisture and heat resistance]
The test piece cut into a length of 50 mm and a width of 250 mm was placed in a thermo-hygrostat adjusted to 70 ° C. and 95% RH: PR-2KTH (manufactured by ESPEC. CORP) for 5 weeks and subjected to wet heat treatment. The test pieces before and after the wet heat treatment were visually observed, and the test pieces after the wet heat treatment were determined using a gray scale of JIS L-0804 standard. Grade 4 or higher was considered acceptable.

[Heat-resistant]
A test piece cut to a size of 10 cm square is placed in a wide-mouth reagent bottle (250 mL bottle with a stopper, made of hard glass) along the side of the wide-mouth reagent bottle, and the inside of the dryer adjusted to 110 ° C. For 400 hours and heat-treated. After the heat treatment, the wide-mouth reagent bottle was taken out from the dryer and cooled to room temperature, and then the reagent piece was taken out from the wide-mouth reagent bottle. The test pieces before and after the heat treatment were visually observed, and the test pieces after the heat treatment were judged using a gray scale of JIS L-0804 standard. Grade 4 or higher was considered acceptable.

[Light resistance]
A test piece cut to a length of 65 mm and a width of 150 mm was bonded to an aluminum plate having the same size and a thickness of 1 mm. It was tested under the following conditions using an accelerated xenon light resistance tester: WT-341 (manufactured by Wacom) equipped with a xenon arc lamp (air-cooled 8 kW).
Irradiation cycle: Continuous irradiation Irradiation time: 144 hours Irradiation intensity: 162 W / m ²
・ Black panel temperature: 89 ± 3 ℃
・ Relative humidity: 50 ± 5%
-Irradiation wavelength: 300-400 nm
The test piece before and after irradiation was visually observed, and the light fastness of the test piece after irradiation was determined using a gray scale of JIS L0804 standard. Grade 4 or higher was considered acceptable.

  The nubuck-like sheet-like material according to the present embodiment is used for various applications such as clothing, bags, shoes, interior materials, vehicle interior materials, and in particular, based on its excellent wear resistance, for example, interior materials and vehicle interior materials. It can be suitably used as a material.

DESCRIPTION OF SYMBOLS 1 ... Nubuck-like sheet-like material 2 ... Fiber base material 3 ... Surface layer 4 ... Front side 5 ... Adhesive layer 6 ... Anchor coat layer 7 ... Protective layer 8 ... Convex part 9 ... Concave part 10, 11 ... Nubuck-like sheet-like substance

Claims (9)

  A nubuck-like sheet-like product obtained by laminating a surface layer made of polyurethane resin on a fibrous base material, wherein the height difference between the convex part and the concave part is 20 to 150 μm on the front side of the nubuck-like sheet-like substance. A nubuck-like sheet-like material having irregularities in which the interval between the vertices is 20 to 150 μm and the surface dynamic friction coefficient of the front surface is 0.20 to 0.50.   The said polyurethane resin consists of a polycarbonate-type urethane resin and a polyether-type urethane resin, and mass ratio of the said polycarbonate-type urethane resin and the said polyether-type urethane resin is 80: 20-20: 80. Nubuck-like sheet.   The nubuck-like sheet-like material according to claim 1 or 2, wherein a front surface is not ground.   The nubuck-like sheet-like material according to any one of claims 1 to 3, wherein the surface layer includes a smoothing agent composed of a silicone compound.   The nubuck-like sheet-like material according to any one of claims 1 to 4, wherein the surface layer contains a tactile sensation improving agent made of wax.   The nubuck sheet material according to any one of claims 1 to 5, wherein the surface layer has a 100% modulus of 1 to 5 MPa.   The nubuck-like sheet-like material according to any one of claims 1 to 6, wherein a protective layer made of a polyurethane resin is provided on the surface layer as an outermost layer forming a front surface of the nubuck-like sheet-like material.   The nubuck sheet material according to any one of claims 1 to 7, wherein an anchor coat layer made of a polyurethane resin is provided under the surface layer. It is a manufacturing method of the nubuck-like sheet-like material according to any one of claims 1 to 8,
A step of applying a surface layer resin solution on a releasable substrate to form a surface layer;
A step of bonding the surface layer and the fibrous base material, and
A step of peeling the releasable substrate,
The manufacturing method of the nubuck-like sheet-like thing which contains these in this order.

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