JP6261332B2 - Skin material - Google Patents

Description

  The present invention relates to a skin material. In particular, the present invention relates to a skin material having a low feeling of contact cooling / heating.

  Conventionally, as a skin material, there are vinyl chloride leather, synthetic leather, artificial leather, natural leather, etc. provided with a resin layer on a fibrous base material, but these are generally compared to skin materials made only of fibrous materials, Susceptible to outside temperature. Therefore, when exposed to extreme temperatures, the skin material itself becomes excessively hot or cold, and when the skin material comes into contact with the skin, it gives a sudden temperature change to the skin, causing discomfort. To remember. In particular, when it is used in a space such as a vehicle interior material that is affected by the outside air temperature, it becomes a significant problem.

  In order to solve such problems, Patent Document 1 discloses a cover cushion material (synthetic material) using a temperature adjusting material in which microcapsules containing a latent heat storage agent that generates a liquid-solid phase change are dispersed in a base material. Leather) and thereby preventing it from becoming too hot or cold. However, although some effects can be obtained in the above-described aspect, if the latent heat storage agent is used for the entire skin material, the cost is high and the versatility is poor.

  In order to solve the above problems, in Japanese Patent Application No. 2013-99297, a porous heat insulating layer is provided in a part of the resin layer, and the contact area ratio of the skin with respect to the surface of the synthetic leather is specified, thereby reducing the contact cold / hot feeling. An improved synthetic leather is proposed. However, when this technique is used for natural leather, there are problems in that the natural texture and wrinkles inherent to natural leather are impaired, and the design of the leather surface is limited.

Japanese Patent Laid-Open No. 2002-399

  The present invention has been made in view of the above points, without impairing the texture and wrinkles that are the original texture of natural leather, and while maintaining the required durability as a skin material, the feeling of contact cold and warm It aims at providing the skin material which can improve.

  The skin material according to the present invention is a skin material in which a porous heat insulating layer and a colored layer are sequentially laminated on a leather base material, and the porous heat insulating layer includes a closed hole having a spherical shape whose upper side is crushed, The porous heat insulation layer has a thickness of 20 to 100 μm, and the porous heat insulation layer has a closed pore area ratio of 40 to 90%.

  According to the present invention, it is affected even when exposed to extreme temperatures without damaging the texture and wrinkles that are the original texture of natural leather, while maintaining the required durability as a skin material. It is difficult to improve the cold feeling of contact, in which it is difficult to feel a temperature change even when the skin comes into contact.

It is a cross-sectional schematic diagram of the skin material which concerns on one Embodiment. It is a cross-sectional schematic diagram of the skin material which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described in detail.

  The skin material according to the present embodiment is a skin material obtained by sequentially laminating a porous heat insulating layer and a colored layer as a resin layer on a leather base material, and the porous heat insulating layer is a spherical shape whose upper side is crushed. The porous heat insulating layer has a thickness of 20 to 100 μm, and the porous heat insulating layer has a closed hole area ratio of 40 to 90%.

  Although the porous heat insulation layer of this embodiment is a thin film with a thickness of 20 to 100 μm, it has a sufficient heat insulation effect. Therefore, the texture and wrinkles that are the original texture of natural leather are not impaired. Moreover, since the influence by the size of the contact area between the skin material and the skin is small, it is possible to provide a skin material that can improve the feeling of contact cold / warmness while having little restrictions on the design of the front surface. Here, the front surface of the skin material is a design surface that appears on the front side when the skin material is used as a skin covering the surface of an object in various applications such as vehicle interior materials, and a person or the like comes into contact with it. It is a surface that can be.

  FIG. 1 schematically shows a cross-sectional structure of a skin material 1 according to an embodiment. In the skin material 1, a porous heat insulating layer 3 and a colored layer 4 are sequentially laminated on one surface of a genuine leather base material 2. In the illustrated example, a protective layer 5 is laminated on the colored layer 4.

  The leather base material used in the present embodiment is not particularly limited, and examples of raw materials include mammals such as cows, horses, pigs, goats, sheep, deer, kangaroos, birds such as ostriches, sea turtles, monitor lizards, Examples include those derived from reptiles such as pythons and crocodiles. Furthermore, recycled leather using floor leather or leather fibers can also be used. Especially, what uses a cowhide with a high versatility and a large area as a raw material is preferable. Raw hides or those that have been salted to prevent decay are called raw hides, and those in this state are used in the leather making process.

  The leather (raw leather) is used to impart durability (heat resistance, rot resistance, chemical resistance, etc.), and the leather-like material is called “leather” (simply called “leather”). It is distinguished from “skin” which is called and not hesitated.

The leather making process is generally divided into a tanning process, a dyeing process, and a finishing process, and is further divided into the following steps.
Moistening process; raw hide, pickled / back split, lining, depilation / lime pickling, splitting, re-lime pickling, decalcification / fermentation, soaking, tanning.
Dyeing process: rehydration, water squeezing / sorting, shaving, re-tanning, dyeing / greasing, setting out, drying, taste-removing, staking (kneading, tapping), tension drying, silver peeling.
Finishing process: painting, ironing / embossing, polishing.

  Although the individual steps are being improved, it can be said that the steps are technically determined and are well known in the art. However, the order may be partially changed, omitted, or replaced with another process.

  Prior to painting, usually silvered. Silver peeling is a process for smoothing the surface by scraping the surface of the silver surface, removing elements that affect the appearance quality such as individual differences, site differences, worms, scratches, and skin scars, and making them uniform. It is. Usually, it is stripped with silver, but it may not be stripped for the purpose of taking advantage of the original design of animal skins.

  After peeling off the silver, the porous heat insulating layer is formed as the first resin layer by coating the surface (generally the silver surface side) of the leather base material.

  It is important that the thickness of the porous heat insulating layer in the present embodiment is 20 to 100 μm, and more preferably 40 to 90 μm. When the thickness of the porous heat insulating layer is 20 μm or more, it is possible to provide a skin material capable of improving the feeling of contact cooling / heating. Moreover, durability required as a skin material, in particular, wear resistance and fir resistance can be maintained. When the thickness of the porous heat insulating layer is 100 μm or less, it is possible to provide a skin material that does not impair the texture and wrinkles that are the original texture of natural leather.

  The porous heat insulating layer in the present embodiment is a heat insulating layer having a large number of closed holes (that is, closed holes that do not penetrate). By being porous, it becomes difficult for heat to be transmitted, the skin material is not easily affected by the outside air temperature, and a skin material with a low feeling of contact cooling / heating can be obtained.

  In the present embodiment, as shown in FIG. 1, the porous heat insulating layer 2 includes a closed hole 6 having a spherical shape in which the upper portion 6 </ b> A is crushed. That is, the blocking hole has a spherical shape as a basic shape, and the upper side thereof is flattened, and the upper portion of the hole has a horizontally long, substantially elliptical cross-sectional shape that is deformed to be nearly flat. Specifically, in the cross-sectional shape shown in an enlarged manner in FIG. 1, the lower portion 6B of the blocking hole 6 has a semicircular shape, and the upper portion 6A has a semielliptical shape. More specifically, the cross-sectional shape of the obstruction hole is preferably a shape in which the side lacking the shape of the moon of the ages 11 to 13 faces upward. By setting it as such a shape, a space | gap increases on the front surface side of a skin material, and sufficient heat insulation effect can be acquired, although a porous heat insulation layer is a thin film of 20-100 micrometers. Here, the moon age defining the cross-sectional shape means that the moon age of cocoon (new moon, lunar and solar meridian difference = 0 °, lunar phase 0) is 0, and hope (full moon, lunar and solar yellow meridian difference) = 180 °, moon phase 14) is the moon age when the moon age is 14, and is also called the moon phase.

  The arrangement configuration of the blocking holes in the porous heat insulating layer is preferably a single layer structure in which the blocking holes are arranged on the same plane, or a multilayer structure in which a plurality of the single layer structures are stacked. As shown in FIG. 1, the single layer structure is a state in which the blocking holes 6 are arranged uniformly on the same plane without any difference in height. As shown in the example of the two-layer structure in FIG. 2, the multi-layer structure has a structure in which the blocking holes 6 are uniformly arranged on the same plane without any difference in height (in FIG. 2, two layers of an upper layer 7A and a lower layer 7B). ). By adopting such an arrangement configuration, the voids can be increased on the front side of the skin material, so that a layer having a low thermal conductivity can be formed, and the porous heat insulating layer is a thin film of 20 to 100 μm. However, a sufficient heat insulating effect can be obtained.

  The closed hole in the porous heat insulating layer may be only one that forms the above-mentioned collapsed sphere, or may be a mixture of one that forms the collapsed sphere and one that is a true sphere, Preferably, the closed hole located at least in the vicinity of the interface with the colored layer has the above-described collapsed spherical shape, and more preferably, all of the closed holes have a collapsed spherical shape. For example, in the case of the single layer structure, it is preferable that all of the blocking holes have a crushed spherical shape, and in the case of the two-layer structure, it is preferable that at least the blocking hole 6 of the upper layer 7A has a crushed spherical shape. Note that, in a multilayer structure such as a two-layer structure, when the closed hole is deformed by a heat pressing process described later, the deformation of the lower layer may be lighter than that of the upper layer, but such an aspect is also included.

  The size of the blocking hole is not particularly limited, and for example, the long diameter of the blocking hole is preferably in the range of 20 to 60 μm, more preferably in the range of 30 to 50 μm. When the major diameter of the blocking hole is 20 μm or more, the effect of improving the feeling of cold contact can be enhanced. Moreover, when the major axis of the blocking hole is 60 μm or less, it is possible to prevent the texture of the natural leather, particularly the texture and wrinkling, from being impaired. As shown in FIG. 1, in the closed hole 6 having a crushed spherical shape, the spherical diameter D on the lower 6B side is the long diameter of the closed hole.

  The thermal conductivity of the porous heat insulating layer is preferably 0.1 W / (m · K) or less, more preferably 0.05 W / (m · K) or less, from the viewpoint of the heat insulating effect.

λr：多孔質断熱層の熱伝導率（Ｗ／（ｍ・Ｋ）)
Ｖ：多孔質断熱層における閉塞孔体積率（％）
λs：多孔質断熱層を形成するマトリックスの熱伝導率（Ｗ／（ｍ・Ｋ）)
λg：閉塞孔内部の気体の熱伝導率（Ｗ／（ｍ・Ｋ）)
※ マトリックスとは、多孔質断熱層を形成する樹脂、及び、その他の添加剤（但し、中空微粒子は除く）の混合物を指す。
※ 多孔質断熱層における閉塞孔体積率（Ｖ）として、本実施形態では、多孔質断熱層の閉塞孔面積率、すなわち、多孔質断熱層の垂直断面における閉塞孔の占める割合を代入する。 The thermal conductivity is obtained by the following calculation formula.

λr: Thermal conductivity of porous heat insulating layer (W / (m · K))
V: Volume ratio of closed pores in porous heat insulation layer (%)
λs: thermal conductivity of the matrix forming the porous heat insulating layer (W / (m · K))
λg: thermal conductivity of gas inside closed hole (W / (m · K))
* Matrix refers to a mixture of resin that forms a porous heat insulation layer and other additives (excluding hollow fine particles).
* As the closed pore volume ratio (V) in the porous heat insulating layer, in this embodiment, the closed hole area ratio of the porous heat insulating layer, that is, the ratio of the closed holes in the vertical cross section of the porous heat insulating layer is substituted.

  The method for calculating the area ratio of the closed pores is to obtain the area ratio of the closed hole portion with respect to the area occupied by the entire porous heat insulating layer of the vertical section by observing the vertical section of the layer with an electron microscope, a microscope, etc. and image processing. by.

  In the present embodiment, the closed hole area ratio is in the range of 40 to 90%. When the obstructed pore area ratio is 40% or more, the thermal conductivity of the porous heat insulating layer can be set to a desired value, and the effect of contact cold / warm feeling can be enhanced. When the blocking hole area ratio is 90% or less, it is possible to prevent the texture of natural leather, in particular, the texture and wrinkles, and the durability, particularly wear resistance and fir resistance, from being impaired. In addition, it is more preferable that the blocking hole area ratio is 70 to 90%.

  The means for forming a large number of closed holes in the porous heat insulating layer is not particularly limited, and a known method can be adopted. Examples thereof include physical foaming by mechanical stirring, chemical foaming by adding a foaming agent, and formation of closed pores by adding hollow fine particles. Preferably, from the viewpoint that the shape and size of the closed hole and the area ratio and volume ratio of the closed hole are easily adjusted, the closed hole is formed by adding hollow fine particles. That is, in this embodiment, the porous heat insulating layer is formed by blending hollow fine particles with a resin that is a matrix (that is, a base material or a main agent), and contains a large number of hollow fine particles in the porous heat insulating layer. It is preferable that a large number of closed holes are formed by the hollow fine particles.

  The hollow fine particles refer to spherical shapes in which minute voids inside are covered with coatings (called outer shells, outer walls, etc.) made of various materials. In particular, it is preferable that no volume expansion occurs even when heat treatment is performed. By using such hollow fine particles, volume fluctuation of the porous heat insulating layer during production can be minimized, quality variation can be reduced, and the resin around the hollow fine particles is stretched and thinned. Can be prevented, and wear resistance can be improved.

  As the hollow fine particles, various particles satisfying the above conditions can be used. Examples thereof include organic hollow fine particles having an outer shell made of a thermosetting resin such as a phenol resin, an epoxy resin or a urea resin, or a thermoplastic resin such as an acrylic resin or a vinyl chloride resin. Alternatively, inorganic hollow fine particles having an outer shell made of glass, shirasu, silica, alumina, carbon or the like can also be mentioned. Moreover, what coat | covered the surface of organic hollow fine particles with inorganic fine powders, such as a calcium carbonate, a talc, or a titanium oxide, can also be used. In particular, after forming the coating film of the porous heat insulating layer, it can be transformed into a desired shape (the above-mentioned crushed spherical shape), and is excellent in heat resistance, wear resistance, and strength. Organic hollow fine particles having a shell or organic hollow fine particles whose surface is coated with an inorganic fine powder are preferable.

  The hollow fine particles having an outer shell made of a thermoplastic resin that is preferably used are typically those obtained by previously foaming a microcapsule type foaming agent. The microcapsule-type foaming agent itself includes a volatile foaming agent such as a low-boiling hydrocarbon in an outer shell made of a thermoplastic resin that can be softened and expanded by heat treatment. In addition to being able to be used by foaming, it can also be used as an already foamed material obtained by foaming in advance. From the viewpoint of easy adjustment of the shape and size of the blocking hole, and the area ratio and volume ratio of the blocking hole, a foamed material is preferable.

  As for the size of the hollow fine particles, the major axis is preferably in the range of 20 to 60 μm, more preferably in the range of 30 to 50 μm. When the major axis is in the above range, the size of the obtained blocking hole can be set to the above-described 20 to 60 μm.

  Examples of the resin used as the main component in the porous heat insulating layer, that is, the resin serving as a matrix, include, for example, known synthetic resins such as polyurethane resins, acrylic resins, epoxy resins, silicone resins, and the like. These can be used in combination. Among these, a polyurethane resin is preferable from the viewpoint of texture and wear resistance, and an acrylic resin is preferable from the viewpoint of texture, moldability (formability in embossing) and versatility, and it is more preferable to use these in combination.

  A polyurethane resin is not specifically limited, For example, a polycarbonate-type polyurethane resin, a polyether-type polyurethane resin, a polyester-type polyurethane resin etc. can be mentioned, These can be used 1 type or in combination of 2 or more types. Among these, from the viewpoint of durability, a polycarbonate-based polyurethane resin is preferable, and from the viewpoint of texture, a polyether-based polyurethane resin is preferable, and a combination thereof is more preferable.

  The form of the polyurethane resin can be used regardless of whether it is solventless (solvent-free), hot-melt, solvent-based, or water-based. And may be appropriately selected depending on the application. Among these, a one-part resin is preferably used because a film can be formed only by removing the solvent by drying. The one-component resin is usually marketed in the form of emulsified dispersion in water (emulsion type) or dissolved in an organic solvent, but the emulsion type is preferably used from the viewpoint of environmental burden.

  The acrylic resin is not particularly limited. For example, acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate; methacrylic acid Alkyl methacrylates such as methyl, ethyl acrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy acrylate Hydroxy group-containing acrylic esters such as butyl; heavy hydroxy group-containing methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, etc. Can be mentioned the body, it can be used in combination thereof one or more.

  A commercially available acrylic resin can be used, and it is usually marketed in the form of being emulsified and dispersed in water (emulsion type) or dissolved in an organic solvent, but the emulsion type is preferably used from the viewpoint of environmental burden.

  In the present embodiment, the porous heat insulating layer preferably has a 10% modulus value of 1.0 MPa or less, more preferably 0.8 MPa or less, from the viewpoint of durability, particularly fir resistance.

The 10% modulus value of the porous heat insulating layer is determined as follows. That is, the resin liquid for forming the porous heat insulating layer is applied on a flat release paper (EU130TPD, manufactured by Lintec Corporation) using a bar coater so that the thickness of the cured film becomes 100 μm, and is applied to the dryer. After heat treatment at 80 ° C. for 2 minutes, a cured film is prepared 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. Attach to a gripping tool (manufactured by Shimadzu Corporation) with a gripping width of 30 mm and a gripping interval of 50 mm, pull at a pulling speed of 100 m / min, and measure the load when the stroke distance reaches 5 mm. The average value of the three points is taken as the 10% modulus value of the porous heat insulating layer.
10% modulus value (MPa) = load when the stroke distance becomes 5 mm (N) / cross-sectional area of the test piece (mm ² )

  If necessary, the resin liquid forming the porous heat insulation layer may contain pigments, matting agents, smoothing agents, surfactants, fillers, leveling agents, and additives, as long as the physical properties of the porous heat insulation layer are not impaired. Various additives such as a sticking agent and a crosslinking agent can be used.

  Although it is not always necessary to color the porous heat insulating layer, it is preferable that the porous heat insulating layer is colored with a desired color, that is, the same color as the colored layer or an approximate color. This facilitates toning by the colored layer. The pigment used for coloring is preferably a pigment having an infrared reflection or transmission function from the viewpoint of suppressing the temperature rise of the skin material itself. Examples of the pigment having an infrared reflection or transmission function include perylene-based and azomethine-based organic pigments, titanium oxide-based and complex oxide-based inorganic pigments, and the like.

  In addition to the additives described above, the resin liquid for forming the porous heat insulating layer contains a solvent as necessary. As the solvent, water is preferably used from the viewpoint of environmental load.

  The porous heat insulating layer is formed by applying a resin liquid for forming the porous heat insulating layer and then performing a heat treatment.

  For application of the resin liquid forming the porous heat insulating layer, for example, a reverse roll coater, a spray coater, a roll coater, a gravure coater, a kiss roll coater, a knife coater, a comma coater and the like can be used without particular limitation. Among them, by forming a uniform film with a small coating amount, it is possible to uniformly apply a pressure to the film when embossing, and it is possible to easily form a porous heat insulating layer having the above single layer structure or multilayer structure. Application by a reverse roll coater is preferred. The coating thickness or wet coating amount may be appropriately set according to the desired thickness of the porous heat insulating layer.

  Examples of the method for forming the porous heat insulating layer having a single layer structure include a method in which the resin liquid is applied with a thickness of about the same as the major axis of the hollow fine particles to a slightly larger thickness and heat-treated. Moreover, as a method of forming a porous heat insulating layer having a multilayer structure, for example, (1) after applying the resin liquid with a thickness of about the same as the major axis of the hollow fine particles to a slightly larger thickness and heat-treating, the same conditions (2) Almost a multiple of the long diameter of the hollow microparticles (ie, approximately 2 times for 2 layers, approximately 3 times for 3 layers) to slightly larger The method of apply | coating the said resin liquid by thickness and heat-processing is mentioned.

  The heat treatment is performed to evaporate the solvent in the paint and dry the resin. In order to prevent excessive moisture evaporation of the leather base material, the heat treatment is preferably performed so that the leather base material itself does not reach a temperature of 80 ° C. or higher. Therefore, it is preferable that the heat processing temperature is 90-130 degreeC, More preferably, it is 100-120 degreeC. The heat treatment time is preferably 1 to 5 minutes, more preferably 2 to 3 minutes. When the heat treatment temperature and the heat treatment time are equal to or higher than the lower limit, drying does not become insufficient. When the heat treatment temperature or heat treatment time is less than or equal to the upper limit value, it is possible to prevent the texture and feel from becoming hard.

  Thus, after forming a porous heat insulation layer, the heat press process is given to the surface of this porous heat insulation layer. By performing the heat pressing process, the closed hole in the porous heat insulating layer can be formed into the desired shape. That is, by heating and pressing the porous heat insulating layer, the upper portion of the closed hole is deformed into a shape close to flat, and the desired shape (spherical shape where the upper side is crushed, specifically, the shape of the moon of the ages 11-13) (The shape with the chipped side facing up). In addition, the thickness of the porous heat insulation layer mentioned above is the thickness of the porous heat insulation layer after a heat press process.

  An example of the heat pressing process is embossing that gives a concavo-convex pattern to the surface. That is, if it is an embossing process, the deformation | transformation process of the said obstruction | occlusion hole can also be performed, providing the design of an uneven | corrugated pattern to the front surface of the obtained skin material.

  A known embossing device can be used for embossing without limitation. The emboss mold may be a roll (emboss roll) or a flat (emboss plate). Furthermore, even if the concavo-convex pattern is manufactured so that the concavo-convex patterns overlap each other in the facing portion (male type and female type), one may have a concavo-convex pattern and the other may have a flat surface. Especially, the embossing apparatus provided with the roll which has an uneven | corrugated pattern and the roll which has a flat surface is preferable at the point that it is excellent in continuous workability and does not impair the texture of a genuine leather base material.

  The shape of the concavo-convex pattern is not particularly limited, and examples thereof include a texture pattern, a geometric pattern such as a point, a straight line, a curve, a dotted line, a circle, an ellipse, a triangle, a quadrangle, and a polygon. The pattern which combined the seed | species or more may be sufficient.

  The heating temperature of the roll or flat plate having the concavo-convex pattern (ie, corresponding to the heat treatment temperature during the heat pressing process) may be set as appropriate, but is preferably performed at a temperature at which the porous heat insulating layer does not melt. . Therefore, it is preferable that heating temperature is 60-120 degreeC. What is necessary is just to set suitably about various conditions, such as the pressure and speed at the time of a press, and the introduction | transduction tension | tensile_strength of a leather base material.

  Next, a colored layer is formed as a second resin layer on the surface of the porous heat insulating layer. The colored layer is a layer for concealing the porous heat insulating layer and coloring the leather product in a desired color.

  As the resin for forming the colored layer, the same resin as the main agent of the porous heat insulating layer can be used. Among these, a polyurethane resin is preferable from the viewpoint of texture and wear resistance, and an acrylic resin is preferable from the viewpoint of texture, moldability (formability in embossing) and versatility, and it is more preferable to use these in combination.

  A pigment such as an inorganic pigment or an organic pigment is added as a colorant to the resin liquid forming the colored layer. Among these, it is preferable to use a pigment having an infrared reflection or transmission function from the viewpoint of suppressing the temperature rise of the skin material itself. As the pigment having an infrared reflection or transmission function, the same pigment as the porous heat insulating layer can be used.

  The addition amount of the colorant is not particularly limited and may be set as appropriate according to the desired color, but is 1.0 to 20 mass in terms of solid content with respect to the entire composition forming the colored layer. % Is preferable, and more preferably 5.0 to 15% by mass. When the added amount is 1.0% by mass or more, the concealability of the porous heat insulating layer and the colorability sufficient as a design can be enhanced. If the addition amount is 20% by mass or less, the anti-friction fastness associated with the decrease in coating film strength is not impaired.

  In addition to the colorant, a known additive such as a smoothing agent, a crosslinking agent, a matting agent, and a leveling agent can be used in the resin liquid for forming the colored layer, if necessary. In addition to the additive, the resin liquid for forming the colored layer contains a solvent as necessary. As the solvent, water is preferably used from the viewpoint of environmental load.

  The colored layer is formed by applying a resin liquid for forming the colored layer and then performing a heat treatment.

  As the coating method of the resin liquid for forming the colored layer, the methods mentioned in the coating method of the porous heat insulating layer can be used. Of these, application by a reverse roll coater or spray coater is preferable because a uniform and thin coating film can be formed. The coating thickness or wet coating amount may be set as appropriate according to the desired thickness of the colored layer.

  The heat treatment is performed to evaporate the solvent in the paint and dry the resin. In order to prevent excessive moisture evaporation of the leather base material, the heat treatment is preferably performed so that the leather base material itself does not reach a temperature of 80 ° C. or higher. Therefore, it is preferable that the heat processing temperature is 90-130 degreeC, More preferably, it is 100-120 degreeC. The heat treatment time is preferably 1 to 5 minutes, more preferably 2 to 3 minutes. When the heat treatment temperature and the heat treatment time are equal to or higher than the lower limit, drying does not become insufficient. When the heat treatment temperature or heat treatment time is less than or equal to the upper limit value, it is possible to prevent the texture and feel from becoming hard.

  The thickness of the colored layer is preferably 1 to 50 μm, more preferably 5 to 40 μm. When the thickness is 1 μm or more, a uniform coating film can be formed, and color unevenness and durability such as wear resistance can be prevented from deteriorating. When the thickness is 50 μm or less, it is possible to prevent the original texture of natural leather, in particular the texture and wrinkling, from being impaired and the effect of improving the feeling of contact cooling and warming from being impaired.

  Thus, the skin material according to the present embodiment is obtained.

  In the skin material of the present embodiment, a protective layer is preferably formed as a third resin layer on the surface of the colored layer. The role of the protective layer is to improve durability such as wear resistance.

  As resin which forms a protective layer, resin similar to the main ingredient of a porous heat insulation layer can be used. Among these, a polyurethane resin is preferable from the viewpoint of texture and wear resistance, and a polycarbonate-based polyurethane resin is more preferable. The type of resin is not particularly limited, such as a solventless system, a solvent system, and an aqueous system.

  Various additives may be added to the resin liquid forming the protective layer, as in the case of the porous heat insulating layer. Among these, it is preferable to add a crosslinking agent from the viewpoint of wear resistance and a colorant (pigment) from the viewpoint of design. The pigment used as the colorant is preferably a pigment having an infrared reflection or transmission function from the viewpoint of suppressing the temperature rise of the skin material itself. As the pigment having an infrared reflection or transmission function, the same pigment as the porous heat insulating layer can be used.

  In addition to the additives described above, the resin liquid for forming the protective layer contains a solvent as necessary. As the solvent, water is preferably used from the viewpoint of environmental load.

  The protective layer is formed by applying a resin solution for forming the protective layer and then performing a heat treatment.

  As the coating method of the resin liquid for forming the protective layer, the methods mentioned in the coating method of the porous heat insulating layer can be used. Of these, application by a reverse roll coater or spray coater is preferable because a uniform and thin coating film can be formed. The coating thickness or wet coating amount may be appropriately set according to the desired thickness of the protective layer.

  The heat treatment is performed to evaporate the solvent in the paint and dry the resin, and when a cross-linking agent is used, accelerates the cross-linking reaction and forms a coating film having sufficient strength. In order to prevent excessive moisture evaporation of the leather base material, the heat treatment is preferably performed so that the leather base material itself does not reach a temperature of 80 ° C. or higher. Therefore, it is preferable that the heat processing temperature is 90-130 degreeC, More preferably, it is 100-120 degreeC. The heat treatment time is preferably 1 to 5 minutes, more preferably 2 to 3 minutes. When the heat treatment temperature and the heat treatment time are equal to or higher than the lower limit, drying does not become insufficient. When the heat treatment temperature or heat treatment time is less than or equal to the upper limit value, it is possible to prevent the texture and feel from becoming hard.

  It is preferable that the thickness of a protective layer is 1-30 micrometers, More preferably, it is 10-25 micrometers. A uniform coating film can be formed as thickness is 1 micrometer or more, and it can prevent that durability, such as abrasion resistance, worsens. When the thickness is 30 μm or less, it is possible to prevent the original texture of natural leather, in particular, the texture and wrinkle, and the effect of improving the feeling of contact cold / warm from being impaired.

  In the skin material of this embodiment, the total thickness of the colored layer and the protective layer is preferably 20 to 50 μm, more preferably 20 to 35 μm. When the total thickness is 20 μm or more, it is possible to prevent the durability, particularly the wear resistance and the fir resistance, from being impaired and the desired designability from being impaired. If the total thickness is 50 μm or less, it is possible to prevent the original texture of natural leather, particularly the texture and wrinkle, from being impaired, and the effect of improving the feeling of contact cooling and warming from being impaired.

  The skin material to which the present invention is directed has a genuine leather base material, a porous heat insulating layer, and a colored layer as essential constituent members. Two or more layers may be provided.

  The use of the skin material of the present invention is not particularly limited. For example, it is used for interior materials for various vehicles including automobile interior materials such as automobile seats, ceiling materials, dashboards, door lining materials or handles. In addition, it can be used for interior applications such as the skin for sofas and chairs.

  Hereinafter, although an Example demonstrates in more detail, this invention is not limited to a following example.

[Example 1]
(1) Preparation of Genuine Leather Base Adult cowhide was used as the raw leather, and silvering was performed through a normal process. The dyeing was performed so as to have the same color as the colored layer.

(2) Formation of porous heat insulating layer [prescription A1]
1) Product name “BAYDERM Bottom DLV”; 160 parts by mass (polycarbonate polyurethane resin, solid content 40% by mass)
2) Product name “BAYDERM Bottom 51UD”; 200 parts by mass (polyether polyurethane resin, solid content 35% by mass)
3) Product name “PRIMAL SB-300”; 200 parts by mass (acrylic resin, solid content 34% by mass)
4) Trade name “Matsumoto Microsphere F-30E”: 20 parts by mass (hollow microparticles: average particle size 45 μm, solid content 11% by mass)
5) Product name “DIRAC BLACK HS-9630”; 160 parts by mass (perylene black pigment, solid content 20% by mass)
6) Product name “EUDERM Nappa Softs”; 110 parts by mass (matting agent, solid content 25% by mass)
7) Product name “EUDERM Matching Agent SN-C”; 120 parts by mass (matting agent / filler, solid content 23% by mass)
8) Product name “EUDERM Paste DO”; 40 parts by mass (matting agent / filler, solid content 52% by mass)
9) Product name “AQUADERM Fluid H”; 10 parts by mass (leveling agent: water-dispersed silicone, solid content 100% by mass)
10) Product name “ACRYSOL RM-1020”; about 10 parts by mass (thickener, solid content 20% by mass)
11) Water; 150 parts by mass The raw materials are made of DIC Corporation, the hollow fine particles are made by Matsumoto Yushi Seiyaku Co., Ltd., and the others are made by LANXESS, excluding water.

  According to prescription A1, each raw material was mixed with a mixer, and the viscosity was adjusted with a thickener so that the viscosity would be 6,500 mPa · s (digital viscometer, manufactured by BROOKFIELD, 25 ° C.).

A resin composition for a porous heat insulation layer prepared according to the above-mentioned formulation A1 is applied to the surface of a genuine leather base material prepared according to the above-mentioned (1), with a reverse roll coater (trade name “JUMBOSTAR-SR”, Ge.Ma.Ta The product was applied so that the wet coating amount was 250 g / m ² and processed at 110 ° C. for 3 minutes with a dryer to form a porous heat insulating layer.

(3) Embossing On the surface of the porous heat insulating layer obtained in (2), using an embossing machine (trade name “KOMBIPRESS-1800NE”, manufactured by BERGI ofb spa), 70 ° C., pressure: 1470 N / M ² , processing speed: 2.8 m / min, heat embossing was performed, and a hair wrinkle pattern design was applied to the surface. The thickness of the porous heat insulating layer after the embossing was 68.7 μm. In addition, the thickness of a layer observes the vertical cross section of a synthetic leather with a microscope (the Keyence Corporation make, digital HF microscope VH-8000), measures the thickness about arbitrary 10 places, and averages these values Was calculated.

(4) Formation of colored layer [prescription B1]
1) Product name “BAYDERM Bottom DLV”; 160 parts by mass (polycarbonate polyurethane resin, solid content 40% by mass)
2) Product name “BAYDERM Bottom 51UD”; 200 parts by mass (polyether polyurethane resin, solid content 35% by mass)
3) Product name “PRIMAL SB-300”; 200 parts by mass (acrylic resin, solid content 34% by mass)
4) Product name “DIRAC BLACK HS-9610”; 160 parts by mass (perylene black pigment, solid content 20% by mass)
5) Product name “EUDERM Nappa Softs”; 110 parts by mass (matting agent, solid content 25% by mass)
6) Product name “EUDERM Matching Agent SN-C”; 120 parts by mass (matting agent / filler, solid content 23% by mass)
7) Product name “EUDERM Paste DO”; 40 parts by mass (matting agent / filler, solid content 52% by mass)
8) Product name “AQUADERM Fluid H”; 10 parts by mass (leveling agent, solid content 100% by mass)
9) Product name “ACRYSOL RM-1020”; about 5 parts by mass (thickener, solid content 20% by mass)
10) Water; 150 parts by mass The raw materials are made of DIC Corporation, and the others are made of LANXESS, except for water.

  According to prescription B1, each raw material was mixed with a mixer and adjusted with a thickener so that the viscosity was 25 seconds (Cup Viscometer, Ford Cup No. 4, Meiji Machinery Co., Ltd., 25 ° C.).

Using a spray coater (trade name “TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the surface of the intermediate product that has undergone step (3), the wet coating amount is 30 g. / M ^2, and a non-porous colored layer was formed by treatment at 110 ° C. for 3 minutes in a dryer. The thickness of the colored layer was 8.3 μm. In addition, the thickness of a layer observes the vertical cross section of a synthetic leather with a microscope (the Keyence Corporation make, digital HF microscope VH-8000), measures the thickness about arbitrary 10 places, and averages these values Was calculated.

(5) Formation of protective layer [Formulation C1]
1) Product name “HYDRHOLAC UD-2”; 340 parts by mass (polycarbonate polyurethane resin, solid content 25% by mass)
2) Product name “HYDRHOLAC Finish HW-2”; 120 parts by mass (polycarbonate polyurethane resin, solid content 35% by mass)
3) Product name “AQUADERM Finish HAT”; 200 parts by mass (polycarbonate polyurethane resin, solid content 40% by mass)
4) Product name “DIRAC BLACK HS-9610”; 20 parts by mass (perylene black pigment, solid content 20% by mass)
5) Trade name “Rosilk 2229”; 70 parts by mass (smoothing agent, solid content 60% by mass)
6) Product name “AQUADERM Additive SF”; 30 parts by mass (smoothing agent, solid content 50% by mass)
7) Product name “AQUADERM Fluid H”; 10 parts by mass (leveling agent, solid content 100% by mass)
8) Product name “AQUADERM XL-50”; 150 parts by mass (crosslinking agent, hexamethylene diisocyanate (HDI), solid content 50% by mass)
9) Product name “ACRYSOL RM1020”; about 10 parts by mass (thickener, solid content 20% by mass)
10) Water; 150 parts by mass The raw materials are made of DIC Corporation, and the others are made of LANXESS, except for water.

  According to prescription C1, each raw material was mixed with a mixer and adjusted with a thickener so that the viscosity was 25 seconds (Cup Viscometer, Ford Cup No. 4, Meiji Machinery Co., Ltd., 25 ° C.).

Using a spray coater (trade name “TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the surface of the intermediate product obtained in (4), the wet coating amount is 25 g. / M ² was applied, and the mixture was treated with a dryer at 110 ° C. for 3 minutes, and this step was repeated twice to form a nonporous protective layer. The thickness of the protective layer was 16.1 μm when converted from the solid content and the coating amount.

Thus, the skin material of Example 1 was obtained. The obtained skin material has a textured pattern on the front surface, the porous heat insulating layer has a single layer structure as shown in FIG. 1, and the shape of the closed hole is a spherical shape whose upper side is crushed. (Denoted as “flattened sphere” in the table). The hollow fine particles blended in the formulation A1 were spherical, but became flattened by embossing after the coating of the porous heat insulating layer was formed. The cross-sectional shape of the obstruction hole was a shape in which the lunar side of the moon of age 12 was facing upward. The size (major axis) of the closed hole is 45 μm, the closed hole area ratio is 75%, the thermal conductivity is 0.04 W / (m · K), the 10% modulus value of the porous heat insulating layer is 0.7 MPa, and coloring The total thickness of the layer and the protective layer was 24.5 μm.
In addition, the shape of the obstruction | occlusion hole observed the vertical cross section of the skin material with the microscope (the Keyence Corporation make, digital HF microscope VH-8000). The size of the blocking hole was determined by observing a vertical section of the skin material with a microscope (manufactured by Keyence Corporation, Digital HF microscope VH-8000), and setting the maximum value as the size of the blocking hole. Obstruction hole area ratio is measured by observing the vertical cross section of the skin material with a microscope (Keyence Corporation, Digital HF microscope VH-8000), reading the image of the porous heat insulation layer into a personal computer, and making the obstruction hole white. After the filling, the area ratio of the closed hole was calculated by binarizing the color of the closed hole and the other part into white and black and counting the white dot part by integration.

[Examples 2 to 9 and Comparative Examples 1 to 4]
All layers were fabricated in the same manner as in Example 1 except that the configuration of each layer was fabricated as shown in Table 1.
In Example 3, the porous heat insulation layer has a two-layer structure as shown in FIG. 2, and the shape of the blocking hole is a spherical shape whose upper side is crushed in both the upper layer 7A and the lower layer 7B, and has a cross-sectional shape. The age of the upper layer 7A was 12 and the lower layer 7B was 13 (indicated as “upper 12 / lower 13” in Table 1). The same applies to Comparative Examples 2 and 3. The porous heat insulation layers of Examples 2, 4 to 6, 9 and Comparative Examples 1 and 4 all had a single layer structure.
Example 6 is an example in which a protective layer is not provided. In Examples 7 and 8, since the resin composition for a porous heat insulating layer was applied thinner than twice the major axis of the hollow fine particles, the hollow fine particles are arranged in two layers, and the arrangement of the closed pores is a non-layered structure. It was.
In Example 9, heat pressing was performed using an iron roll having a flat surface instead of the emboss roll. Temperature, pressure, and processing speed are the same as in the embossing. On the other hand, Comparative Example 4 is an example in which the pressure was changed to 735 N / m ² under the embossing conditions. Since the pressure was low, the closed hole of the porous heat insulating layer was not deformed, and the cross-sectional shape was substantially true. It was circular.

For the prepared skin material, contact area ratio, contact cooling feeling (q _max ), sensory evaluation of contact cooling feeling, sensory evaluation of contact temperature feeling, texture, wrinkle, wear resistance, and fir resistance evaluation The following method was used, and the results are shown in Table 1.

[Contact area ratio]
The contact area ratio is a simple calculation of the ratio of the area where the skin is in close contact with the front surface of the skin material when a person touches the skin material. Specifically, on the front surface of the skin material, a rectangular region of 2.5 mm in length and 2.0 mm in width is randomly extracted, and XY coordinates are obtained using a laser microscope (VK-8500, manufactured by Keyence Corporation). The depth at every 10 μm was measured. The ratio of the number of XY coordinates indicating the depth from the top of the highest convex portion existing in the region (that is, the highest point in the region) to 50 μm with respect to the total number of XY coordinates on the front surface of the skin material The contact area ratio was used. Extraction of the region was performed at 10 locations at random, and the average value of the contact area ratios calculated at these 10 locations was defined as the contact area ratio on the front surface of the skin material.

[Evaluation of cold feeling of contact (measurement of q _max )]
As an evaluation of the cold feeling of contact, q _max was measured using a precise rapid thermophysical property measuring apparatus (KES-F-M7 Thermolab II type, manufactured by Kato Tech Co., Ltd.). This apparatus includes a sample stage on which a skin material as a sample is attached, and a detector. A copper thin plate is attached to one surface of the detector, and a temperature sensor is attached to the back surface of the copper thin plate. A heater is attached to the sample stage and the detector, and the temperature can be set independently by a control device.
A skin material is affixed to the sample stage, the sample stage is set to 20 ° C. by the control device, and the temperature of the copper thin plate of the detector is set to 40 ° C. Next, in the atmosphere of 20 ° C. × 60% RH, the front surface of the skin material on the sample table is brought into contact with the copper thin plate of the detector, and at the same time, the sensor output from the temperature sensor is recorded. At this time, the copper thin plate is deprived of heat by the sample stage through the skin material, and the temperature decreases. The maximum heat absorption rate (q _max ) at this time was measured. The higher the value of q _max is large, the cold feeling when touched people feel larger.

[Evaluation of cold contact feeling (sensory evaluation)]
The test piece was allowed to stand at 0 ° C. for 30 minutes, and then, when the subject brought the palm into contact with the front surface of the skin material, the cooling feeling felt by the subject was determined according to the following criteria. In addition, the sensory evaluation by the subject calculated the average of the evaluation by 10 subjects.
6… No sudden temperature change is felt at all 5… Slight temperature change is felt slightly, but there is no discomfort 4… Slight temperature change is felt slightly, but there is no discomfort 3… Rapid temperature change 2… Slight discomfort 2… Severe sudden temperature changes are felt and uncomfortable 1… Sudden temperature changes are strongly felt and there is considerable discomfort

[Evaluation of contact sensation (sensory evaluation)]
The test piece was allowed to stand at 70 ° C. for 30 minutes, and then the contact temperature feeling felt by the subject when the subject brought the palm into contact with the front surface of the skin material was determined according to the following criteria.
6… No sudden temperature change is felt at all 5… Slight temperature change is felt slightly, but there is no discomfort 4… Slight temperature change is felt slightly, but there is no discomfort 3… Rapid temperature change 2… Slight discomfort 2… Severe sudden temperature changes are felt and uncomfortable 1… Sudden temperature changes are strongly felt and there is considerable discomfort

[Texture]
One test piece having a size of 150 mm square was collected, and a strain measurement value (BLC value) when it was pushed in with a load of 500 g was measured using ST300 Laser Softness Tester (manufactured by BLC Laser Technology Center Ltd.). Judgment was made according to the following criteria. The greater the strain measurement, the more flexible and the better the texture.
◎: 3.0 mm or more ○: 2.5 mm or more, less than 3.0 mm Δ: 2.0 mm or more, less than 2.5 mm ×: less than 2.0 mm

[With bowl]
The wrinkle at the time of bending (how to enter wrinkles into the colored layer when folded by hand for 3 seconds with the colored layer as the inner surface) was evaluated according to the following criteria.
◎: Skin material without a porous heat insulation layer and dense wrinkles comparable to that of ○ ○: Slightly dense wrinkles enter △: Large and coarse wrinkles enter ×: Almost no wrinkles enter

[Abrasion resistance]
One specimen is taken from each of the vertical and horizontal directions with a width of 50 mm and a length of 120 mm. Next, the test piece is fixed to the table of a friction tester I type (Clock Meter: manufactured by Tester Sangyo Co., Ltd.) as follows.
A silicon tube having an inner diameter of 4 mm, an outer diameter of 6 mm, and a length of 100 mm (code number 55-586-12, manufactured by Inoue Seieido Co., Ltd.) is attached to the table of the testing machine, and a 15 mm gap is formed between the silicon tube and the test piece. Attach the test piece as follows. At this time, it fixes with a double-sided tape so that the width | variety of a test piece may be set to 35 mm.
Next, a cotton canvas (JIS L3102: average cotton canvas No. 9) cut to 60 mm square is attached to a friction element (2 cm square flat plate) with double-sided tape. With the load applied to the friction element so that the surface pressure becomes 330 g / cm ² , the stroke is 50 mm, the state of the coating is checked every 1000 times at a 50 times / minute cycle, and the wear operation is performed up to 20000 times. Went.
The number of frictions at which coating film cracking, peeling, etc. occurred was evaluated as wear resistance. The greater the number of frictions, the better the wear resistance.

[Fir resistance]
Two test pieces are collected from each of the vertical and horizontal directions with a width of 25 mm and a length of 120 mm. Two test pieces in the same direction are overlapped with the front side facing inward, and the test piece is attached with a spacing of 15 mm between the grips of a Scott type abrasion resistance tester (manufactured by Daiei Kagaku Seisakusho). Gradually narrow the gap between the grips so that the two test pieces are open and separated from each other, apply the load after the front surfaces of the test pieces lightly touch each other until the load reaches 9.8 N Reduce the interval. The state of the coating film was confirmed every 1000 times at a stroke of 40 mm and a cycle of 120 times / minute, and fir operation was performed up to 6000 times.
The fir resistance was evaluated based on the number of fir occurrences at which coating film peeling occurred. The greater the fir frequency, the better the fir resistance.

As shown in Table 1, Examples 1 to 9 maintain the necessary wear resistance and fir resistance as a skin material without damaging the texture and wrinkles that are the original texture of natural leather. However, the feeling of contact cold / warm was improved. As is clear from the comparison between Examples 7 and 8 and the other examples, the arrangement structure of the closed holes of the porous heat insulating layer is the above-mentioned single-layer or multi-layer structure. In comparison, it is possible to further improve the balance between the cold feeling of contact, the texture and the wrinkles.
In Comparative Example 1, the porous heat-insulating layer was too thin, the contact cold / warm feeling was inferior, and the fir resistance was insufficient. In Comparative Example 2, the porous heat insulating layer was too thick and inferior in texture and wrinkles. In Comparative Example 3, the closed hole area ratio of the porous heat insulating layer was too low, and the contact cold / warm feeling was inferior. In Comparative Example 4, since the closed pores of the porous heat insulating layer were not flattened, the thin porous heat insulating layer did not provide a sufficient heat insulating effect and was inferior in the feeling of contact cooling / heating.

DESCRIPTION OF SYMBOLS 1 ... Skin material 2 ... Genuine leather base material 3 ... Porous heat insulation layer 4 ... Colored layer 5 ... Protective layer 6 ... Closure hole

Claims (7)

A skin material in which a porous heat insulating layer and a colored layer are sequentially laminated on a genuine leather base material,
The porous heat insulating layer includes a closed hole having a spherical shape whose upper side is crushed, the thickness of the porous heat insulating layer is 20 to 100 μm, and the area ratio of the closed hole of the porous heat insulating layer is 40 to 90%. Is the skin material.   The skin material according to claim 1, wherein the porous heat insulating layer is formed by blending hollow fine particles with a resin that serves as a matrix, and the closed pores are formed by the hollow fine particles.   The skin material according to claim 1 or 2, wherein the cross-sectional shape of the blocking hole is a shape in which a side lacking the shape of the moon of the ages 11 to 13 is directed upward.   4. The porous heat insulation layer according to claim 1, wherein the porous heat insulation layer has a single layer structure in which closed pores are arranged on the same surface, or a multilayer structure in which a plurality of the single layer structures are stacked. The skin material according to claim 1.   The thickness of the said colored layer is 1-50 micrometers, The skin material of any one of Claims 1-4 characterized by the above-mentioned.   The skin material according to any one of claims 1 to 5, wherein a protective layer is laminated on the colored layer.   The skin material according to claim 6, wherein the total thickness of the colored layer and the protective layer is 20 to 50 μm.

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