JP5227630B2 - Leather-like sheet and manufacturing method thereof - Google Patents

Description

  The present invention relates to a leather-like sheet having gas permeability and moisture permeability and a method for producing the same.

  Silver-like natural leather with a skin layer has been used extensively in clothing, footwear, bags and other various leather products. In recent years, however, there has been a growing awareness of the protection of birds and beasts, so materials that can replace natural leather have been demanded. Furthermore, natural leather has a change in appearance when wet, and there are inherent discomfort due to large amounts of water absorption and inconvenience of aftercare. Various leather-like sheet-like materials such as artificial leather and synthetic leather as alternatives have been proposed.

  Synthetic leather, which is a kind of leather-like sheet, is generally made of a synthetic resin material that is waterproof and moisture permeable and is used as a skin layer. A natural leather having a texture close to that of natural leather and having performances such as gas permeability, moisture permeability, and wear strength has been developed.

  As the skin layer of the leather-like sheet-like material, for example, a synthetic resin material such as a nonporous film made of polyurethane resin or a porous film thereof is used. Here, the nonporous film as the skin layer of the leather-like sheet is a thin film produced by a dry production method. Unlike the porous film, the nonporous film has a moisture permeability function secured by a hydrophilic functional group (hereinafter referred to as “hydrophilic group”) included in the film.

  When the water vapor concentration on one side of this non-porous film is increased, water molecules are taken in via the hydrophilic group of the film, and the water molecules are transferred to the other side of the film where the water vapor concentration is low. The film is diffused from the other side of the film. That is, the nonporous film has moisture permeability that allows water molecules to pass through by its own hydrophilic group, and waterproofness that prevents raindrops from penetrating.

  However, since the non-porous film has a very low gas permeability to allow air to pass through or is not gas permeable in the first place, if it is used as the skin layer of a leather-like sheet, Gas permeability cannot be imparted to the sheet-like material. For this reason, for example, in a garment product using a leather-like sheet-like material using such a nonporous film as a fabric, heat is excessively trapped between the wearer and the garment product. There was a problem of obstructing.

  On the other hand, a porous film as a skin layer of a leather-like sheet has a large number of pores communicating with each other in the thickness direction, and a large number of these pores are open to the surface of the porous film. And evenly distributed. The porous film has a pore size larger than the particle size of water vapor (about 0.0004 μm) and smaller than the particle size of rain particles (about 100 μm to 3 mm), moisture permeability allowing water vapor particles to pass through, and penetration of rain particles It has waterproofness to prevent

If such a porous film is used as the skin layer of the leather-like sheet material, the leather-like sheet material having waterproofness and moisture permeability can be further passed through a large number of pores. Since gas permeability is also provided, the problem regarding the gas permeability inherently contained in the nonporous film is also eliminated.
JP-A-8-41786

  However, in the above-described porous film, once oil with low volatility (hereinafter referred to as “low volatility oil”) penetrates into the pores, the oil cannot be easily removed therefrom. There was a point. On the other hand, even if non-volatile films such as sebum and various oils such as edible oil adhere to the surface of the nonporous film, they do not penetrate into the film and easily wipe off the oil. Is possible.

  For example, an uncolored porous film inherently has a white color because light is irregularly reflected by countless pores existing in the film or on the front and back surfaces thereof. However, when low-volatile oils and fats adhere to such a white porous film, the front and back surfaces and the light reflectance inside thereof are lowered, and the entire porous film becomes transparent. For this reason, in the cloth using the non-colored porous film, there is a problem that the stain due to the low volatile oil is emphasized and the appearance of the cloth is impaired.

  On the other hand, according to the porous film colored with a pigment, when low-volatile oils and fats adhere to the surface, they penetrate into the pores, so that the light reflectance of the surface portion decreases, and the surface The color is dark. Therefore, even in a cloth using a colored porous film, there is a problem that the stain due to the low volatile oil is emphasized and the appearance of the cloth is impaired.

  Therefore, in order to solve the above-described problems, the present invention has a leather-like sheet shape that has both gas permeability and moisture permeability, and further has antifouling properties (oil contamination resistance) against oil and fat stains. The object is to provide a product and a method of manufacturing the product.

In order to achieve this object, the leather-like sheet according to claim 1 has gas permeability and moisture permeability, and is a microporous material having a large number of micropores communicating in the thickness direction from the front surface to the back surface. A microporous membrane layer formed of a microporous polyurethane resin having gas permeability and moisture permeability and having hydrophobicity or non-hydrophilic property, and a surface laminated on the microporous membrane layer The surface treatment layer is provided with a protective film layer having gas permeability formed by solidifying an aqueous resin on the microporous film layer, and the protective film layer is The water-based resin is formed discontinuously on the microporous membrane layer .

The leather-like sheet-like material according to claim 2 is the leather-like sheet-like material according to claim 1 , wherein the surface treatment layer is a leather imitating natural leather printed on the microporous membrane layer using a printing agent. The protective film layer is formed using the water-based resin on the microporous film layer on which the leather pattern is printed.

A leather-like sheet material according to a third aspect is the leather-like sheet material according to the first or second aspect , and includes a base fabric layer made of a fabric laminated under the microporous membrane layer.

The leather-like sheet-like material according to claim 4 is the leather-like sheet-like material according to any one of claims 1 to 3 , wherein the base fabric layer is made of a fabric and the thickness direction from the surface to the back surface is formed on the base fabric layer. And a porous intermediate layer made of a porous polyurethane resin having a large number of pores larger in diameter than the fine pores, and the microporous membrane layer is laminated on the porous intermediate layer .

The leather-like sheet material according to claim 5 is the leather-like sheet material according to any one of claims 1 to 4 , wherein the microporous membrane layer has a peak value of a pore size distribution of the micropores of 0.3 μm to 3 μm. Within range.

The leather-like sheet material according to claim 6 is the leather-like sheet material according to any one of claims 1 to 5 , wherein the protective film layer has a thickness in the range of 1 μm to 10 μm.

The above-described method for producing a leather-like sheet is a method for producing a leather-like sheet having gas permeability and moisture permeability, and is a microporous membrane layer made of a microporous polyurethane resin having gas permeability and moisture permeability. On top of this, by applying an aqueous resin with a predetermined thickness, the aqueous resin is solidified to form a protective film layer having gas permeability.

The manufacturing method of the leather-like sheet are those which the protective layer is formed by the aqueous resin is applied on the microporous membrane layer by a gravure coating method (coating) .

  According to the leather-like sheet of the present invention and the method for producing the same, by forming a protective film layer made of a water-based resin on a microporous film layer made of a microporous polyurethane resin, it has gas permeability and moisture permeability. There is an effect that it is possible to obtain a leather-like sheet-like material that is excellent in practical use and excellent in surface oil contamination and wear strength.

  Hereinafter, a leather-like sheet-like material which is a preferred embodiment of the present invention will be described. The leather-like sheet has gas permeability and moisture permeability, and mainly includes a microporous membrane layer and a surface treatment layer. In addition to the microporous membrane layer and the surface treatment layer, at least one of the base fabric layer and the porous intermediate layer or both of them may be added to the leather-like sheet-like material as necessary. good.

<Microporous membrane layer>
The microporous membrane layer imparts gas permeability, water permeability, waterproofness and surface abrasion strength to the leather-like sheet, and is produced by wet coagulation of a polyurethane resin liquid. Made of thin film. The microporous polyurethane resin here refers to a polyurethane resin having a large number of micropores in a solidified state. The polyurethane resin refers to a resin containing as a main component a copolymer obtained by polyaddition reaction of an isocyanate component such as polyisocyanate as a main raw material and a hydroxy component such as polyol (hereinafter the same).

  For example, as the polyurethane resin for forming the microporous membrane layer, polycarbonate polyurethane, polyether polyurethane, polyester polyurethane, polyether-ester polyurethane and the like are used, but are not particularly limited. The microporous membrane layer has a thickness in the range of 10 μm to 50 μm, and preferably has a thickness of 30 μm to 35 μm. In addition, the microporous membrane layer has a large number of micropores communicating with each other in the thickness direction, and the micropores are open and uniformly scattered on the front and back surfaces of the microporous membrane layer. Yes.

  A large number of micropores are formed in the microporous membrane layer by about 500,000 per unit area (1 square inch), and the pore size distribution effective for providing both water permeability and waterproofness. The peak value (hereinafter simply referred to as “pore diameter distribution peak value”) is in the range of 0.3 μm to 3 μm. Thus, in the microporous membrane layer, the pore size distribution peak value of the micropores is in the range of 0.3 μm to 3 μm, and the pore size distribution peak value of the general porous film is in the range of 1 μm to 20 μm. Compared with, the porous structure is dense. This densification of the porous structure improves the surface smoothness of the microporous membrane layer, and further reduces the surface shaking and distortion during wear, thus improving the surface wear strength. It is illustrated.

  Thus, while the microporous membrane layer has a pore size distribution peak value of micropores in the range of 0.3 μm to 3 μm, the particle size of water vapor is approximately 0.4 nm (= 0.004 μm). In the case of raindrops, the particle size from the finest drizzle to the largest thunderstorm ranges from about 100 μm to about 3 mm (= 3,000 μm). Therefore, the microporous membrane layer has a moisture permeability that allows water vapor particles to pass through the large number of micropores because the pore size of the micropores is larger than the particle size of water vapor and smaller than the particle size of raindrops. It has waterproofness that prevents the penetration of raindrops.

  Furthermore, it is more preferable that the microporous membrane layer is formed such that the pore diameter of the micropores on the surface is generally smaller than the pore diameter of the micropores on the back surface. In this case, the surface side of the microporous membrane layer having a small pore size is defined as the surface side of the leather-like sheet, and the surface treatment layer is formed on the surface side of the microporous membrane, so that the raindrops are fine. It becomes more difficult to penetrate into the porous membrane layer.

The microporous membrane layer has a moisture permeability of 13,000 to 18,000 g / m ² · 24 h, and a water resistance of 10,000 mmH ₂ O (water column) (= 1 kgf / cm ² ≈0.098 Mpa) or more. . Here, the water resistance is “Method B (high water pressure method)” of “Water resistance test (hydrostatic pressure method)” in JIS standard L1092 “Waterproof test method for textile products” (hereinafter “JIS standard L1092 (Method B)). It is also measured in accordance with "." The moisture permeability is “calcium chloride method (A-1 method)” (hereinafter also referred to as “JIS standard L1099 (A-1 method)”) in JIS standard L1099 “Method of testing moisture permeability of textile products”. It is measured in accordance with “potassium acetate method (B-1 method)” (hereinafter also referred to as “JIS standard L1099 (B-1 method)”).

  Furthermore, the microporous polyurethane resin forming the microporous membrane layer is also imparted with hydrophobicity or non-hydrophilicity. For this reason, in the microporous membrane layer, the peripheral portion of each micropore is also made hydrophobic or non-hydrophilic. Thus, since it is hydrophobic or non-hydrophilic, the microporous membrane layer also has waterproofness, which is a property that is contrary to gas permeability and moisture permeability. Moreover, since the material of the microporous membrane layer is hydrophobic or non-hydrophilic, durability against deterioration with time is enhanced.

  Here, as the microporous polyurethane resin having hydrophobicity or non-hydrophilicity, for example, a microporous polyurethane using an organic solvent having hydrophobicity or non-hydrophilicity (including a ketone solvent such as methyl ethyl ketone (MEK)). Even a microporous polyurethane resin using a resin or a hydrophilic organic solvent (for example, including dimethylformamide (DMF)) to which a hydrophobic component such as a water repellent is added is used.

  In addition, the microporous membrane layer is formed of an organic solvent type microporous polyurethane resin, so that, for example, the pore diameter of the pores is made finer than when formed with an aqueous polyurethane resin such as an aqueous polyurethane resin. And the number of pores per unit area can be increased. In other words, the microporous membrane layer is formed of an organic solvent-type microporous polyurethane resin, so that the waterproof property and moisture permeability are superior to those formed of an aqueous microporous polyurethane resin. . The water-based polyurethane resin is a kind of water-based resin, and a polyurethane water obtained by introducing a hydrophilic component necessary for stable dispersion in water in the molecule or by using an external emulsifier for dispersion. It is a dispersion.

  The microporous membrane layer may be colored by adding a predetermined amount of pigment to the polyurethane resin forming it. However, the microporous membrane layer colored by adding a pigment has a porous structure that includes a large number of micropores on the surface and in the interior, so that incident light is irregularly reflected, resulting in a hue corresponding to the amount of pigment added. In fact, it will be lighter.

  As described above, the microporous membrane layer is preferably formed of an organic solvent type microporous polyurethane resin from the viewpoint of waterproofness, moisture permeability, and surface wear strength. However, even an inorganic solvent type polyurethane resin such as a water-based polyurethane resin may be used as a material for the microporous membrane layer as long as it is hydrophobized by adding a water repellent or the like. However, when the microporous membrane layer is formed using an inorganic solvent type polyurethane resin such as a water-based polyurethane resin, the microporous membrane layer is compared with that using the above organic solvent type microporous polyurethane resin. It is necessary to consider that the diameter of the fine holes increases and that the surface wear strength slightly decreases.

<Surface treatment layer>
The surface treatment layer imparts various surface characteristics as the leather surface to the surface of the leather-like sheet, and the leather pattern and protective film layer formed on the above-mentioned microporous film layer (surface side) And.

<Leather pattern>
The leather pattern gives a leather-like sheet-like material with a leather-like appearance design and texture, and uses a predetermined printing agent on the above-mentioned microporous membrane layer (surface side). This is a simulated pattern imitating natural leather. This leather pattern printing method is not particularly limited as long as the leather pattern can be printed on the microporous film layer using a printing agent. For example, a screen method, a roll method, and a gravure method are used. It is done.

  The leather pattern mainly gives the leather-like sheet surface with a unique design (design) of leather, so it is indispensable especially when a design imitating natural leather is unnecessary. Is not an element of Therefore, when a leather pattern is unnecessary, a protective film layer may be formed directly on the surface of the microporous film layer.

<Protective film layer>
The protective film layer protects the surface of the microporous film layer as the skin layer of the leather-like sheet, and in particular, further enhances the surface wear strength of the microporous film layer. It imparts resistance (oil contamination resistance) against oil stains (oil contamination). This protective film layer is a thin film layer formed by coating and solidifying an aqueous resin on the microporous film layer (surface side). The water-based resin here means, for example, a forced emulsification resin obtained by forcibly emulsifying a polymer having no emulsifying property or water solubility using a surfactant or the like, and a self-emulsifying property obtained by emulsifying and dispersing a polymer having self-emulsifying property. This refers to a resin or a water-soluble resin in which a water-soluble polymer is dissolved.

  For example, as the water-based resin forming the protective film layer, those having weather resistance and abrasion resistance are suitable, and water-based polyurethane resins such as ether polyurethane and polycarbonate polyurethane are more preferable. Among these, polycarbonate polyurethane is superior to ether polyurethane in terms of weather resistance and abrasion resistance, and is particularly protective film for leather-like sheets that are expected to be used in harsh environments. It is preferable to employ polycarbonate-based polyurethane as the material of the layer.

  As described above, the protective film layer is formed of an aqueous resin, whereas the microporous film layer is formed of a hydrophobic or non-hydrophilic polyurethane resin as described above. The aqueous resin forming the layer has a lower affinity for the microporous membrane layer than the oil-based resin (solvent type resin). Therefore, when the aqueous resin liquid is applied on the microporous membrane layer, the aqueous resin liquid exerts surface tension on the microporous membrane layer, and is repelled on the microporous membrane layer to form a microporous film. It becomes difficult to penetrate into each micropore on the surface of the membrane layer.

  That is, the water repellency of the surface of the microporous membrane layer prevents the water-based resin from penetrating into the microporous membrane layer, and the water-based resin is surely solidified on the surface of the microporous membrane layer. Thus, the protective film layer is reliably formed on the surface. Moreover, the thickness of the protective film layer is in the range of 1 μm to 10 μm, and is formed in an extremely thin ultrathin shape even when compared with the thickness of the microporous film. Here, since the water-based resin as the material of the protective film layer is easier to adjust the viscosity than the oil-based resin, it is extremely difficult to apply an ultra-thin film on the microporous film layer by fine viscosity adjustment. Is suitable.

  In addition, the protective film layer is formed by coating the aqueous resin in an ultrathin film as described above, and the microporous film layer is hydrophobized or non-hydrophilic. It is formed by solidifying the resin in a discontinuous state on the microporous membrane layer. Here, FIG. 1 is a drawing-substituting photograph in which the surface of the leather-like sheet-like material in the following examples, that is, the surface of the protective film layer formed on the microporous film layer, was photographed with a scanning electron microscope (SEM). It is.

  As shown in FIG. 1, the protective film layer of the leather-like sheet has a form in which the solidified film of the water-based resin becomes a large number of fine pieces and these are arranged in a scale shape. These fine pieces are laminated on the microporous membrane layer so as to partially overlap each other. By the way, as demonstrated from the following examples, even if the protective film layer is formed on the microporous film layer, the leather-like sheet does not lose gas permeability or moisture permeability.

  For this reason, the protective region does not entirely cover the microporous membrane layer, and in the protective membrane layer, there are some gaps between the solid pieces of the solidified coating layered one above the other. It is assumed that such a gap communicates with the micropores of the microporous membrane layer. Moreover, when observing FIG. 1, not all of the fine pieces of the solidified coating are continuously connected to each other, but there are also some gaps between the adjacent fine pieces of the solidified coating, and from there It is assumed that the surface of the microporous membrane layer is exposed.

  That is, the protective film layer communicates with the surface of the microporous membrane layer through a gap between the protective region, which is a region where the solidified coating of the aqueous resin coating the microporous membrane layer exists, and the solidified coating of the aqueous resin. It is inferred that it has a non-protected area that is an area. From the above, in this specification, “the water-based resin is discontinuously present on the microporous membrane layer” means that the non-protected region exists locally in the presence of the solidified coating of the water-based resin serving as the protected region. It is said that it has a form like that.

  Since the water-based resin solidified on the microporous membrane layer is laminated in a discontinuous manner in this way, the protective membrane layer has all the micropores present on the surface of the microporous membrane layer. Will not be blocked. As a result, since the surface of the microporous membrane layer has a non-protected region where the protective region in the protective film layer does not exist locally, the gas permeability and permeability of the microporous membrane layer are passed through the micropores communicating with the non-protected region. Moisture is ensured.

  Further, the coating method of the protective film layer is not particularly limited as long as it is a method in which a water-based resin liquid is directly applied onto the microporous film layer. For example, a gravure coater, a knife coater, a pipe coater, a kiss coater, etc. The coating method performed by the apparatus is used. In particular, according to the gravure coating method using a gravure coater, by adjusting the roll mesh size, the water-based resin is applied so that a large number of fine water spots are scattered on the microporous membrane layer with an arbitrary distribution density. Can be crafted.

  In addition, it is guessed that the coated minute dot-like water-based resin spreads on the microporous membrane layer before solidifying, and becomes the above-mentioned minute piece solidified coating. In other words, the water-based resin coated so that a large number of minute dots are scattered on the microporous membrane layer spreads after coating until it solidifies, thereby forming a large number of minute solidified coatings. It is inferred that they are arranged in a scale on the porous membrane layer.

<Base fabric layer>
Next, the base fabric layer will be described. The base fabric layer is formed by laminating under the microporous membrane layer (on the back side) in the leather-like sheet-like material composed of the microporous membrane layer and the surface treatment layer as described above. This base fabric layer is for imparting tensile strength and overall texture as leather to a leather-like sheet. This base fabric layer is formed of a fabric. Examples of the fabric to be the base fabric layer include woven fabrics, knitted fabrics or nonwoven fabrics, which are natural fibers such as cotton and silk, polyamide fibers such as nylon 6 and nylon 66, or polyester fibers alone or in combination. Is used.

  The base fabric layer may be subjected to functional processing such as dyeing processing or antistatic processing. Further, the fabric to be the base fabric layer is not necessarily limited to the materials described above, and the fabric structure or knitted structure is not particularly limited, and at least air permeability or gas permeability. In addition, any material having moisture permeability may be used.

(Means for laminating the base fabric layer under the microporous membrane layer)
As a lamination method for laminating such a base fabric layer under the microporous membrane layer (back side), either a lamination method or a wet coating method is used.

  The lamination method referred to here is a method in which a film having gas permeability and moisture permeability is adhered on a base material, and the film is integrally laminated on the base material (the same applies hereinafter). On the other hand, in the wet coating method, the resin liquid is applied (coated) directly on the base material, and then the base material is passed through the water to solidify the resin while eluting the solvent contained in the resin into the water. Thus, traces of solvent elution from the resin become a large number of communication holes, and as a result, a resin layer having gas permeability and moisture permeability is directly laminated on the base material (the same applies hereinafter).

  For example, according to the lamination method, the above-mentioned microporous membrane layer is laminated on the base fabric layer by adhering the microporous polyurethane film onto the base fabric layer (one surface). At this time, the microporous polyurethane film is point-bonded or line-bonded to the base fabric layer by an adhesive applied in a fine dot-like or line-like manner between the surfaces facing the base fabric layer. Then, in the microporous membrane layer, the ratio of the micropores on the surface facing the base fabric layer being covered with the adhesive is minimized, and the gas permeability and moisture permeability of the microporous membrane layer are suppressed from being lowered. .

  In addition, in the case of using the lamination method, the production method of the microporous polyurethane film to be the microporous membrane layer is not particularly limited, but in order to form the above-mentioned micropores uniformly and densely, it is produced by a wet coagulation method. More preferably.

  In addition, according to the wet coating method, the polyurethane resin liquid is directly coated on the base fabric layer (one surface) in a uniform thin film shape, and then the laminate is passed through water to apply polyurethane applied to the base fabric layer. The solvent contained in the resin is solidified while eluting into water, so that the trace of solvent elution from the polyurethane resin applied to the base fabric layer becomes a large number of micropores. As a result, the above-mentioned microporous membrane layer becomes the base fabric layer. It is laminated directly on the top.

  The direct coating method is not particularly limited as long as it is a method of directly applying a polyurethane resin solution for forming a microporous membrane layer. For example, a gravure coater, a knife coater, a pipe coater, a kiss coater, etc. The coating method performed by the apparatus is used.

<Porous intermediate layer>
Next, the porous intermediate layer will be described. The porous intermediate layer is formed by laminating between the above-described base fabric layer and the microporous membrane layer, or under the microporous membrane layer (back side) instead of the base fabric layer. This porous intermediate layer is a thin film made of a porous polyurethane resin that imparts a leather texture such as elasticity and thickness to the leather-like sheet. The porous polyurethane resin as used herein refers to a polyurethane resin having a large number of pores in a solidified state. In particular, the pore diameter (pore diameter distribution peak value) of the pores forms a microporous membrane layer. It is larger than the micropores of the polyurethane resin and has a small number of pores per unit area.

  In addition, in order to ensure gas permeability and moisture permeability, this porous intermediate layer is formed with a large number of pores communicating with each other in the thickness direction, and these numerous pores are formed on the front and back surfaces of the porous intermediate layer. Are scattered in the open. Examples of the polyurethane resin that forms the porous intermediate layer include polycarbonate polyurethane, polyether polyurethane, polyester polyurethane, and polyether-ester polyurethane, but are not particularly limited.

  Here, various characteristic values such as the thickness of the porous intermediate layer, the pore diameter, and the number of pores per unit area are not particularly limited, and depend on the use of the leather-like sheet. Can be changed as appropriate. For example, the pore size of the pores of the porous intermediate layer is not particularly limited, and may be a general porous polyurethane that exceeds the pore size distribution peak value of the microporous membrane layer.

(Means for laminating a microporous membrane layer on a porous intermediate layer)
The lamination method for laminating the microporous membrane layer on the porous intermediate layer (surface side) is the same as the lamination method as in the case of laminating the microporous membrane layer on the base fabric layer. Alternatively, any of wet coating methods may be used.

  For example, according to the lamination method, the above-mentioned microporous membrane layer is laminated on the base fabric layer by adhering a microporous polyurethane film on the porous intermediate layer. At this time, the microporous polyurethane film and the porous intermediate layer are naturally point-bonded or line-bonded in order to suppress a decrease in gas permeability and moisture permeability of the microporous membrane layer and the porous intermediate layer. . In addition, the adhesive agent used at this time is not specifically limited, For example, a hot-melt type, a 2 liquid solvent type, etc. are used.

  For example, according to the wet coating method, a polyurethane resin liquid is directly coated on the porous intermediate layer in a uniform thin film, and then the laminate is passed through water to be applied to the porous intermediate layer. The solvent contained in is solidified while eluting into water, so that the traces of solvent elution from the polyurethane resin applied to the porous intermediate layer become a large number of micropores. As a result, the above-mentioned microporous membrane layer becomes a porous intermediate layer. Laminated directly on the layer. The direct coating method is not particularly limited, and a coating method performed by an apparatus such as a gravure coater, a knife coater, a pipe coater, or a kiss coater as described above is used.

(Means for laminating a porous intermediate layer on a base fabric layer)
Moreover, as a lamination | stacking system for laminating | stacking such a porous intermediate | middle layer on a base fabric layer, you may use any of a wet coating system, a dry coating system, or a lamination system.

  For example, according to the wet coating method, after a polyurethane resin liquid is directly coated on one surface of the base fabric layer in a uniform film shape, the laminate is passed through water and contained in the polyurethane resin applied to the base fabric layer. By solidifying the solvent while eluting into water, the traces of the solvent elution from the polyurethane resin become a large number of pores, and as a result, the porous intermediate layer described above is directly laminated on the base fabric layer. The direct coating method is not particularly limited. For example, a coating method performed by an apparatus such as a gravure coater, a knife coater, a pipe coater, or a kiss coater is used.

  For example, according to the dry coating method, after coating a polymer solution prepared by mixing a foaming agent with a polyurethane resin liquid directly on one surface of the base fabric layer in a uniform film shape, the polyurethane resin is dried and dry-solidified. After the solvent is vaporized from the polyurethane resin together with the foaming agent, a large number of pores are formed. As a result, the porous intermediate layer described above is directly laminated on the base fabric layer. The direct coating method is the same as that used in the wet coating method.

  For example, according to the lamination method, the porous intermediate film is laminated on the base fabric layer by adhering a porous polyurethane film to one surface of the base fabric layer. At this time, the porous intermediate layer (porous polyurethane film) and the base fabric layer are naturally point-bonded or line-bonded in order to suppress a decrease in gas permeability and moisture permeability of the porous intermediate layer. In addition, the adhesive agent used at this time is not specifically limited, For example, a hot-melt type, a 2 liquid solvent type, etc. are used.

  The leather-like sheet-like material obtained by the present embodiment is generally used for clothing, interiors, bags, shoes, gloves, miscellaneous goods, belts, school bags, baseball gloves, balls, etc. It is used in all application fields where leather-like sheets are used.

  Next, preferred embodiments of the present invention will be described. First, the evaluation method performed with respect to the leather-like sheet-like material of the present example will be described below. In the examples, “parts” and “%” are based on weight, and the characteristic measurement values and characteristic evaluation results of the leather-like sheet were obtained by the following methods. .

(color)
The color was measured with respect to the hue (H), lightness (V), and saturation (C) of the leather-like sheet using Color-Eye7000A manufactured by GretagMacbeth.
(Moisture permeability)
The moisture permeability is measured in accordance with JIS K6549 “Leather moisture permeability test method” for leather-like sheets.
(Peel strength)
The peel strength is measured in accordance with JIS standard L1089 “Test method for adhesive cloth for clothing” for leather-like sheet-like materials.
(Water resistance)
The water resistance is measured in accordance with JIS standard L1092 (Method B) for a leather-like sheet.
(Abrasion resistance)
Abrasion resistance is an evaluation of the surface change of a leather-like sheet (test piece) subjected to the following friction test based on the following evaluation method.
(Friction test)
The friction test is performed on a leather-like sheet using a “Gakushin type friction tester” in JIS standard L0849 “Test method for dyeing fastness to friction”, and a white cotton cloth for friction is applied to the tip of the friction piece of the friction tester. (Kanakin No. 3) is attached, and in the case of the dry test, the friction white cotton cloth is left as it is. In the case of the wet test, the friction white cotton cloth is made 100% wet with water, and is loaded 500 times with a load of 200 g. It rubs.
(Abrasion resistance evaluation method)
For the evaluation of abrasion resistance, the leather-like sheet subjected to the above-mentioned friction test was subjected to the most changed portion (hereinafter referred to as “evaluation portion”) of the surface and “discoloration color” in accordance with JIS standard L0804. Compared with "Grayscale for use", the evaluation part of the leather-like sheet as the test piece was visually judged to determine whether it is equivalent to or close to what color chart of "Grayscale for color fading" .
(Oil contamination resistance)
The oil contamination resistance is determined by dropping a drop of sesame oil (manufactured by Kadoya Oil Co., Ltd.) as a low-volatility oil on the surface of the leather-like sheet that is the test piece, and letting it stand for 10 minutes. Then, the surface of the leather-like sheet-like material to which sesame oil was adhered was wiped off with tissue paper, and the discolored portion due to the contamination was determined by comparison with a “contamination gray scale” conforming to JIS standard L0805.

<Example>
The leather-like sheet-like material of the present example is a twill fabric of polyester and rayon as a base fabric layer, and has a thickness of 400 μm to 420 μm. A porous intermediate layer having a thickness of 80 μm to 85 μm and a pore diameter distribution peak value of 15 μm to 90 μm is formed on the base fabric layer by a wet coating method. Measurement of moisture permeability, water resistance, abrasion resistance (dry test), abrasion resistance (wet test) and oil contamination resistance of the laminate of the base fabric layer and porous intermediate layer laminated in this way The evaluation results are as shown in Table 1.

  Further, on the porous intermediate layer, a hot melt type adhesive is uniformly applied in a number of minute dots using a gravure coater, and then microporous with a thickness of 30 μm to 35 μm manufactured by a wet coagulation method. A microporous polyurethane film having a pore size distribution peak value of 0.3 μm to 3 μm is spot-bonded. By this point adhesion, a microporous membrane layer made of a microporous polyurethane film is laminated on the porous intermediate layer. The microporous polyurethane film forming the microporous membrane layer is previously colored with a leather-like brown color.

  Here, the characteristic measurement values regarding the microporous polyurethane film forming the microporous membrane layer in this example are as shown in Table 2.

Further, a leather pattern is further printed on the microporous membrane layer. This leather pattern is formed by applying (applying) a predetermined printing agent to the surface of the microporous membrane layer by a gravure method using a gravure coater, and drying the printing agent after this application. . A prescription example of the printing agent used at this time is as follows.
(Prescription example of printing agent)
Rack Skin U-2265
[Seiko Kasei Co., Ltd.]: 100 parts Methyl ethyl ketone (MEK) 33.5 parts Dimethylformamide (DMF): 33.5 parts Dilac Yellow PV-5822
[Dainippon Ink Chemical Co., Ltd.]: 1.5 parts Dilac Brown PV-5818
[Dainippon Ink Chemical Co., Ltd.]: 1.5 parts Dilac Black PV-5824
[Dainippon Ink Chemical Co., Ltd.]: 1.5 parts

  Furthermore, a protective film layer is formed on the microporous film layer on which this leather pattern is printed. This protective film layer is coated (applied) with a predetermined aqueous resin at a processing speed of 10 m / min on the microporous film layer by a gravure coating method using a gravure coater (70 mesh, roll having a depth of 110 μm). ) And drying the aqueous resin after this coating.

In such a case, when an aqueous polyurethane resin (solid content 20%) is used as the aqueous resin, the viscosity of the aqueous polyurethane resin is preferably adjusted within the range of 1000 cps to 7000 cps. Therefore, a prescription example of the water-based resin is as follows. In addition, the viscosity of the water-based resin based on the following formulation example is adjusted to 4000 cps.
(Prescription example of water-based resin)
Shine Binder B1006 (solid content 40%)
(Ether polyurethane resin)
[Matsui Dye Chemical Co., Ltd.]: 100 parts Water: 300 parts

  About the leather-like sheet-like material of Examples obtained as described above, the above-mentioned color, moisture permeability, peel strength, water resistance, abrasion resistance (dry test), abrasion resistance (wet test), and resistance The oil contamination property was measured or evaluated, and the measurement and evaluation results are shown in Table 3 below. Moreover, in this Table 3, the measurement and evaluation result are written together about the same item as the leather-like sheet-like material of a present Example regarding the comparative examples 1-3 mentioned below.

<Comparative Example 1>
The leather-like sheet-like material of Comparative Example 1 is common to the leather-like sheet-like material of this example except that the above-described protective film layer is absent. In other words, Comparative Example 1 includes the base fabric layer, the porous intermediate layer, the microporous membrane layer, and the surface treatment layer consisting only of the leather pattern in the above-described Examples.

<Comparative example 2>
The leather-like sheet material of Comparative Example 2 is intended to improve the oil contamination resistance and the surface wear strength (wear resistance) in place of the above-described protective film layer as compared with the leather-like sheet material of this example. Then, a water repellent is applied with a gravure coater on the microporous film layer on which the leather pattern is printed. That is, Comparative Example 2 includes the base fabric layer, the porous intermediate layer, the microporous membrane layer, and the surface treatment layer composed of the leather pattern and the water repellent in the above-described Examples. In addition, the formulation example of the water repellent used at this time is as follows.
(Prescription example of water repellent)
Fluorine-based water repellent (solid content 20%): 5 parts Water: 95 parts

<Comparative Example 3>
The leather-like sheet of Comparative Example 3 has oil contamination resistance and surface wear resistance (wear resistance) in place of the above-described protective film layer made of water-based resin, compared to the leather-like sheet of this example. For the purpose of improvement, an oil-based polyurethane resin is applied with a gravure coater on a microporous film layer on which a leather pattern is printed to form a protective film layer made of an oil-based resin. That is, in Comparative Example 3, the base fabric layer, the porous intermediate layer, the microporous film layer, and the surface treatment layer including the leather pattern and the protective film layer made of an oil-based resin are provided. In addition, the formulation example of the oil-based resin used at this time is as follows.
(Formulation example of oil-based resin)
Oil-based polyurethane resin (solid content 20%) 100 parts

  According to Table 3, the leather-like sheet-like material of this example has almost the same measurement results regarding color, moisture permeability, peel strength and water resistance as compared with Comparative Examples 1 to 3, and wear resistance. Better evaluation results were obtained with respect to (dry test and wet test) and oil contamination resistance.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements in various dimensions, shapes, materials, and the like can be made without departing from the spirit of the present invention. It can be easily inferred that deformation is possible.

It is the drawing substitute photograph which image | photographed the surface of the protective film layer with the scanning electron microscope (SEM).

Claims (6)

In a leather-like sheet having gas permeability and moisture permeability,
A microporous polyurethane resin having a large number of micropores communicating in the thickness direction from the front surface to the back surface, formed of a microporous polyurethane resin having gas permeability and moisture permeability, and having hydrophobicity or non-hydrophilicity A microporous membrane layer,
And a surface treatment layer laminated on the microporous membrane layer,
The surface treatment layer comprises a protective film layer having gas permeability formed by solidifying a water-based resin on the microporous film layer ,
The protective film layer is formed by the discontinuous presence of the water-based resin on the microporous film layer . The surface treatment layer comprises a leather pattern imitating natural leather printed using a printing agent on the microporous membrane layer,
The protective layer is, the leather-like sheet according to claim 1, wherein that the leather pattern is formed by using the water-based resin on the microporous membrane layer in a state of being printed. The leather-like sheet-like product according to claim 1 or 2 , further comprising a base fabric layer made of a fabric laminated under the microporous membrane layer. A base fabric layer made of a fabric, and a porous intermediate layer made of a porous polyurethane resin formed on the base fabric layer and communicating in the thickness direction from the front surface to the back surface and having a large number of pores having a pore diameter larger than the fine pores. The leather-like sheet-like product according to any one of claims 1 to 3 , further comprising: a microporous membrane layer laminated on the porous intermediate layer. The leather-like sheet material according to any one of claims 1 to 4 , wherein the microporous membrane layer has a peak value of a pore size distribution of the micropores within a range of 0.3 µm to 3 µm. The leather-like sheet material according to any one of claims 1 to 5 , wherein the protective film layer has a thickness in a range of 1 µm to 10 µm.