JP2007002342A - Functional leather-like sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suitable leather like sheet having a functionality. <P>SOLUTION: In the functional leather like sheet consisting of a fibrous substrate layer 1, a porous covering layer 2 formed on at least one side surface of the substrate and functional fine particles 3, the functional fine particles exist at the inside of pores of the porous covering layer without being contained at the inside of the resin constituting the porous covering layer, and have opened up apertures 4 having 1-100 μm mean diameter on their surfaces. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a functional leather-like sheet comprising functional fine particles represented by antibacterial / deodorant and the like in a surface porous layer.

  Conventionally, various methods have been proposed as leather-like sheets having functions such as antibacterial properties and deodorizing properties. In the case of a suede-like leather-like sheet having fiber napping, a method of incorporating functional fine particles into fibers, resin, or the like that form fiber napping or a sheet structure is common. On the other hand, in the case of a leather-like leather-coated sheet composed of a fibrous base layer and a resin coating layer, the resin fine coating layer is generally used as the site for containing the functional fine particles. This is because the functionality cannot be effectively exhibited unless the fine particles are present as close to the surface as possible, but on the other hand, the foreign particles are present in the coating layer, which has a problem of adverse effects on the appearance, texture, and surface strength. It is mentioned as a point. As a concrete proposal for solving such problems, a deodorant is contained in a resin layer other than the outermost skin layer of a leather-like sheet having a multilayer resin layer formed on the surface, and leather A method of providing a through-hole with a needle in a sheet (for example, see Patent Document 1) or a method of applying a resin containing an antibacterial agent on the surface of a surface coating layer in a spot shape (for example, see Patent Document 2) Etc.). However, in the former method, since the holes are opened with a needle, there is a bad influence on the appearance and a great restriction on the design, and the deodorant present inside the resin is exposed to a small surface area inside the opening. There is a tendency that only a part of the original deodorizing ability can be exerted because it can be contacted, and in the resin layer containing the deodorant, the deodorant is still a foreign substance, and thus deterioration of physical properties and deterioration of the texture cannot be avoided. In addition, the latter method inevitably has an adverse effect on the appearance and feel of the surface due to the applied antibacterial agent, although it is spot-like. Above all, the surface strength is inferior, and the antibacterial agent falls off due to wear during use. It has a serious drawback that the antibacterial effect is greatly reduced.

JP-A-9-31863 (page 2-4) JP 2002-88661 A (page 2-4)

  The present invention is not solved by the conventional method as described above, but has a bad influence on the sensitive surface such as the appearance and texture as a leather-like sheet by using the functional fine particles, and the physical properties such as surface strength and flexibility. Furthermore, the present invention provides a functional leather-like sheet that is maximized without losing the inherent performance of functional fine particles.

In order to achieve the above-mentioned problems, the present inventors have conducted intensive research, and as a result, by making functional fine particles such as antibacterial and deodorant exist in a large number of holes formed in the porous coating layer, It has been found that a leather-like sheet imparted with functionality can be obtained without impairing the performance inherent to the fine particles and without adversely affecting the appearance, texture, surface strength, and the like. The present invention has been completed based on such findings.
Specifically, the present invention provides the following functional leather-like sheet and a method for producing the functional leather-like sheet.
1. Resin in which functional fine particles constitute a porous coating layer in the pores of the porous coating layer in a functional leather-like sheet comprising a fibrous base layer, a porous coating layer formed on at least one side thereof, and functional fine particles A functional leather-like sheet, which is present without being contained therein, and has an aperture having an average diameter of 1 to 100 μm on the surface of the functional leather-like sheet.
2. 1. The fiber substrate layer comprising a nonwoven fabric composed of fibers or fiber bundles mainly composed of ultrafine fibers having an average fineness of 0.3 dtex or less and a polymer elastic body provided therein. Functional leather-like sheet.
3. 1. The porous film layer is laminated on the surface of the porous coating layer. Or 2. Functional leather-like sheet.
4). A treatment liquid in which a porous coating layer having pores having an average diameter of 1 to 100 μm is formed on at least one surface of a fibrous base layer, and functional fine particles are dispersed in a non-solvent of a resin forming the porous coating layer. A method for producing a functional leather-like sheet, wherein the porous coating layer is introduced into the pores from the aperture and then the non-solvent is removed.
5. 3. Remove the surface portion of the porous coating layer laminated on at least one side of the fibrous base layer to form a porous coating layer having pores with an average diameter of 1 to 100 μm. The manufacturing method of the functional leather-like sheet | seat of description.
6). 4. The above-mentioned 4 or 5, wherein a porous film layer having pores having an average diameter of 1 to 100 μm is further laminated on the surface of the porous coating layer having pores having an average diameter of 1 to 100 μm. The manufacturing method of the functional leather-like sheet | seat of description.

  The functional leather-like sheet of the present invention does not greatly impair the original functionality of the fine particles having functionality represented by antibacterial / deodorant, etc., and sufficiently exhibits its functionality, and the appearance and physical properties of the surface It is an excellent leather-like sheet.

  Examples of the fibrous base layer used in the present invention include woven fabrics, knitted fabrics, non-woven fabrics, or fibrous sheets obtained by combining and combining them, and various resins and treatment agents in the interior or surface of these fibrous sheets. And the like. Among them, those using a non-woven fabric are preferable as those capable of expressing a texture and texture close to natural leather, and most preferably, a non-woven fabric composed of fibers or fiber bundles mainly composed of ultrafine fibers is used. A polymer elastic body is added. In general, the ultrafine fiber often refers to a fiber having a fineness of 1 dtex or less, but the preferred ultrafine fiber in the present invention has an average fineness of 0.3 dtex or less. By using such ultrafine fibers, it is possible to express a texture and texture closer to soft and natural leather than can be expressed with thick fibers.

Examples of the method for producing ultrafine fibers include a method of directly obtaining ultrafine fibers by melt spinning, a composite fiber obtained by composite spinning or mixing spinning of two or more thermoplastic polymers having no compatibility with mechanical stress, For example, a method of obtaining a fiber bundle composed of ultrafine fibers by using a difference in shrinkage ratio or removing by dissolving or decomposing at least one component is used.
In the former method, since the fibers constituting the fiber sheet are in the state of ultrafine fibers from the initial stage of manufacturing the fibrous base layer, processing restrictions in the subsequent processes are large, so processing is generally preferred. This is the latter method with good properties. Among the composite fibers obtained by the latter method, a typical fiber form is a so-called sea-island fiber having a sea-island cross-section in which at least one other component is interspersed in a fiber cross-section composed of at least one component. In general, by removing the polymer component forming the region corresponding to the sea, ultrafine fibers made of the polymer component corresponding to the islands are obtained.

As a polymer that can form an island component of sea-island type fibers, it is a polymer that can be melt-spun and sufficiently exhibits fiber physical properties such as strength, and has a higher melt viscosity than the sea-component polymer under the spinning conditions, and surface tension. Polymers having a large size are preferable, for example, polyamide-based polymers such as nylon 6 and nylon 66, and copolymers mainly composed thereof, polyester-based polymers such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and the like. And the like are preferably used.
Further, as a polymer that can form a sea component, the melt viscosity is lower than that of the island component polymer, the solubility or the decomposability with the island component is different, and the solvent used for dissolving or removing the sea component polymer, or A polymer having a high solubility or decomposability by a decomposing agent or the like and a low compatibility with the island component polymer is preferable. For example, polyethylene, modified polyethylene, polypropylene, polystyrene, modified polyester, polyvinyl alcohol and the like are suitably used.

  In the composite fiber that generates ultrafine fibers, a suitable volume ratio between the ultrafine fiber component and the other components is in the range of ultrafine fiber component: other components = 30/70 to 70/30. If the ratio of other components is less than 30%, it is excellent in that there are few components to be removed and there are few useless components, but the volume occupied by the removed components becomes space, and the fibrous substrate itself When the apparent density of the fiber is lowered and the degree of freedom is imparted to the ultrafine fibers, the flexibility of the resulting fibrous base material, and thus the leather-like sheet, cannot be fully expressed. On the other hand, if the ratio of the other components exceeds 70%, the component remaining after removing the other components, that is, the absolute amount of ultrafine fibers is too small, so in the physical properties of the fibrous base material, and thus the leather-like sheet, It is an inappropriate ratio from the viewpoint of environment and productivity in that the required level cannot be secured and there are many components to be removed.

The average fineness of the ultrafine fibers in the present invention is preferably 0.3 dtex or less, more preferably 0.1 dtex or less, and even more preferably 0.05 dtex or less. When the fineness of the ultrafine fibers exceeds 0.3 dtex, the flexibility of the fibrous base layer is impaired, and it becomes easy to feel harsh. The lower limit of the average fineness of the ultrafine fibers is not particularly limited for obtaining the intended effect of the present invention, but from the viewpoint of physical properties and productivity as a leather-like sheet, 0.0001 decitex is temporarily used. It is a standard. The average fineness of the ultrafine fibers can be obtained by observing the leather-like sheet with an electron microscope or the like, measuring the average diameter of the ultrafine fibers, and calculating it.
The ultrafine fiber generating composite fiber needs to be produced in various forms such as a staple form and a filament form depending on the form of the fibrous sheet to be employed, but the method that can be employed in the present invention is not particularly limited. In addition, any conventionally known method can be employed. For example, in the case of a staple, a staple having a desired form can be obtained through processes such as stretching, crimping, heat setting, and cutting by the following known methods.

  Various types of oil agents may be imparted to the ultrafine fiber generating composite fiber in one or more types, one step or a plurality of steps at any stage from spinning to fiber sheet formation. The types of oils to be applied include polyorganosiloxane, which has the effect of reducing the friction between fibers, various modified silicone oils, and mineral oil, which has the effect of reducing the coefficient of friction between metals by combining the fibers. A known oil agent such as a system oil agent or other oil agent having an antistatic effect is preferably applied in one step as much as possible by blending a plurality of types while considering the characteristics of the fiber. If the composite fiber is a staple, for example, before the crimping of the composite fiber, after crimping, or when using a plurality of types of composite fibers, or when using a composite fiber and other fibers in combination. Any process such as fiber blending may be used. As a method for forming a staple-like ultrafine fiber-generating composite fiber into a fiber sheet, a web is obtained via a card and a webber, and the web is laminated to a predetermined weight, and then subjected to an entanglement process such as a needle punch to obtain a nonwoven fabric. However, since composite fibers are particularly susceptible to troubles such as winding and fiber cracking in the card process and needle punching process, it is preferable to give an oil agent that reduces the coefficient of friction to the composite fibers. .

  In the needle punching process of the present invention, any of the conventionally known felt needles can be used according to the purpose, and a felt needle having various factors such as thickness, length, number and position of barbs, and shapes appropriately adjusted is used. For example, in order to efficiently entangle the fibers constituting the laminated web in the thickness direction, a 1 barb felt needle that is less likely to cause fiber breakage is preferably used. Moreover, in order to make the density of the surface part higher than the density of the middle layer part in the apparent density in the thickness direction of the nonwoven fabric, a multi-barb felt needle such as 3 barb, 6 barb, 9 barb can be suitably used. . Therefore, these felt needles may be used in appropriate combination depending on the purpose.

The number of punches in the needle punching process varies depending on the shape of the needle to be used and the thickness and weight of the web to be processed, but is set in a range of approximately 200 to 2500 punches / cm ² . Generally, in the needle punching process of ultrafine fiber generating composite fibers, if the needle punching conditions are too strong, the ultrafine fiber generating composite fibers are cut or broken, and the entangled state is not improved. If the conditions are too weak, the number of fibers for improving the peel strength between the laminated webs oriented in the thickness direction will be insufficient, and variations in quality and physical properties will tend to occur.

  The nonwoven fabric entangled with a needle punch or the like may be pressed in the thickness direction for the purpose of smoothing the surface or adjusting the thickness or apparent density. As the pressing method, any conventionally known method such as a method of passing a nonwoven fabric between a plurality of pressurized heating rolls and a method of passing a preheated nonwoven fabric between pressurized cooling rolls can be used, and the method is particularly limited. Although it is not a thing, in the ultrafine fiber generation type | mold composite fiber, the method of fuse | melting and crimping | bonding the component which mainly comprises the fiber surface, or a low melting-point component is preferable. For example, when the sea component is polyethylene and the island component is a sea island type fiber of nylon 6, smoothing and evenness can be achieved by performing any one of the above pressing processes at a temperature higher than the melting point of polyethylene and lower than the melting point of nylon 6. A thick nonwoven fabric can be obtained. In the pressing process, an adhesive that can be removed in a subsequent process such as polyvinyl alcohol, starch, or resin emulsion may be applied for the purpose of suppressing unintentional shape change due to tension or excessive crushing due to pressing. .

  Next, the polymer elastic body is applied to the inside of the nonwoven fabric that is entangled and pressed as necessary. Examples of the application method include a conventionally known method, that is, a method in which an organic solvent solution of a polymer elastic body is impregnated or coated and then solidified into a sponge (porous) by a wet method, or an aqueous dispersion of a polymer elastic body And a method of coagulating by a dry method after impregnation or coating. In the polymer elastic body solution or dispersion, as necessary, surfactant, heat-sensitive gelling agent, plasticizer, curing agent, pigment, dye, mica, talc, cotton powder, flame retardant, foaming agent, etc. Various additives such as conventionally known processing agents, colorants, and functionalizing agents may be blended. As the polymer elastic body, any resin that has been conventionally used in the production of leather-like sheets can be suitably used. That is, a polyurethane-based resin, a polyvinyl chloride resin, a polyacrylic acid-based resin, a polyamino acid-based resin, a silicone-based resin, and a copolymer or a mixture thereof are preferable examples. Among these, polyurethane-based resins are the most preferred polymer elastic bodies in the present invention because they can provide a natural leather-like texture, feel and the like, and are excellent in durability.

  When the fiber constituting the nonwoven fabric is not an ultrafine fiber but an ultrafine fiber generating composite fiber, a step of ultrafinening the ultrafine fiber generating composite fiber is performed as a process before or after applying the polymer elastic body. . The ultrafine method is a method of removing the sea component by treating it with an appropriate solvent or decomposition agent if the composite fiber is a sea-island type, and at the interface between different components if the composite fiber does not contain the component to be removed. There is a method of carrying out a squeeze treatment so as to cause cracking and separation by splitting, and there is no particular limitation in the present invention. Thus, it is possible to obtain a fibrous base layer composed of a non-woven fabric mainly composed of fibers or fiber bundles mainly composed of ultrafine fibers of 0.3 decitex or less, and a polymer elastic body provided therein. it can.

  The thickness of the fibrous base layer can be arbitrarily selected according to the application and is not particularly limited, but is preferably 0.3 to 3 mm. In addition, the mass ratio of the nonwoven fabric and the polymer elastic body in the fibrous base layer is preferably 35/65 to 85/15. By making it within this range, the balance of the texture becomes good in the fibrous base material layer in which the nonwoven fabric and the polymer elastic body are combined, and the leather-like sheet of the present invention using the same is used in the intended purpose of the present invention. A suitable sense of fulfillment and flexibility are easily obtained.

  As a method for forming a porous coating layer for supporting functional fine particles on at least one surface of the fibrous base layer, any conventionally known method can be adopted, and the fibrous base layer is not particularly limited. A method of solidifying a polymer elastic body applied in a liquid state such as a solution, dispersion, melt, etc. in a porous state by providing a certain clearance with a roll coater or knife coater on at least one side of the layer, or a fibrous base layer Any of the methods in which a porous layer previously formed on a base material different from the above by a method similar to the above is bonded to at least one surface of the fibrous base layer is preferable. The former method may be carried out after the fiber base layer is formed, but it is also preferably carried out during the formation of the fiber base layer, for example, after the entanglement of the nonwoven fabric and after the impregnation with the polymer elastic body. The polymer elastic body can be coagulated in a porous state by wet coagulation of the solution, dry coagulation of the dispersion liquid in a mechanically foamed state, or by mixing a foaming agent into the treatment liquid. Examples include foaming methods and methods using processing liquids containing fine particles and fine fibers that can be extracted after coagulation. Any of these methods can be used, but in particular, a large number of fine, vertically long holes can be formed. A method of wet coagulating the elastic body solution is preferred. In addition, the method of forming many vertically long holes is not particularly limited, and a known wet coagulation method is applied.

  As the resin for forming the porous coating layer, any of the same polymer elastic bodies suitable for the fibrous base layer can be adopted, and the surface strength and film-forming properties required for the coating layer, the fibrous base layer The polyurethane resin is preferably used from the viewpoints of elasticity, softness, abrasion resistance, easy formation of the porous layer, and the like. Preferred polyurethane resins are mainly composed of a polymer glycol having a hydroxyl group at both ends and a molecular weight of 500 to 5000, an aromatic diisocyanate such as 4,4'-diphenylmethane-diisocyanate, and a lower alkylene glycol having 2 to 6 carbon atoms. Polyurethane obtained from a hard segment, or a polyurethane obtained from a hard segment mainly composed of a polymer glycol having a hydroxyl group at both ends and a molecular weight of 500 to 5000, an aliphatic or alicyclic diisocyanate, an organic diamine or an organic acid dihydrazide, etc. Can be given. For the purpose of adjusting softness, durability, processability, easy formation of the porous layer, etc. to a more suitable range, copolymers and mixtures of these polyurethanes are also preferably used.

  Examples of the polymer glycol having a hydroxyl group at both ends and having a molecular weight of 500 to 5,000 are represented by polyester glycols such as polyethylene adipate glycol, polybutylene adipate glycol, polyhexamethylene adipate glycol, polycaprolactone glycol, and polyhexamethylene carbonate glycol. Polyether glycols such as polycarbonate glycol, polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, or a mixture of polyether glycols such as these are used. And polycarbonate glycol, polyester glycol, polycarbonate And a mixture of bets based glycol and polyether-based glycol.

  Examples of the aliphatic diisocyanate include tetramethylene diisocyanate and hexamethylene diisocyanate, and examples of the alicyclic diisocyanate include cyclohexane diisocyanate and 4,4′-dicyclohexylmethane diisocyanate. Examples of the organic diamine include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminediphenylmethane, ethylenediamine, propylenediamine, diethanolamine, 4,4′-diaminodicyclohexylmethane, isophoronediamine, and the like. Adipic acid dihydrazide, sebacic acid dihydrazide, terephthalic acid dihydrazide, isophthalic acid dihydrazide and the like.

  Typical examples of the lower alkylene glycol having 2 to 6 carbon atoms include ethylene glycol, butanediol, hexanediol, diethylene glycol, dipropylene glycol and the like. Among them, ethylene glycol is preferable in that good embossing property can be obtained. The embossability will be described later.

  Openings having an average diameter of 1 to 100 μm are formed on the surface of the porous coating layer formed on at least one side of the fibrous base layer. The method for forming the aperture is not particularly limited, but when the aperture on the surface of the porous coating layer formed above is smaller than the required diameter, a method of buffing with sandpaper or the like, porous coating A method of applying and drying a treatment solution containing a resin solvent for forming a layer is preferably used. If the aperture is larger than the required diameter, a solution or dispersion of a polymer elastic body is used as a gravure coater, spray coater, etc. The method of applying and drying by the above is preferably used. Of course, in the above-described method for forming the porous coating layer, it is also a preferable method to form the porous coating layer at the same time as forming the porous coating layer by adjusting the conditions. Further, the average diameter of the apertures may be adjusted to a necessary size by the above method, after the functional fine particles are introduced into the porous coating layer by the method described later. In addition, it is also possible to form an opening having an average diameter of 1 to 100 μm by embossing.

  By inserting functional fine particles such as antibacterial agents and deodorants from the pores on the surface of the porous coating layer, it can function without being contained in the resin constituting the porous coating layer inside the pores of the porous coating layer Presents fine particles. As a method for charging, a dispersion medium in which the porous coating layer is not dissolved, preferably a dispersion in which functional fine particles are dispersed in an aqueous dispersion medium, is applied to the surface of the porous coating layer having an opening, and the dispersion medium is applied. The method of drying is preferable. For example, when functional fine particles are introduced from the opening portion by such a method, the functional fine particles are introduced without being partially covered or shielded by the resin constituting the porous coating layer. Therefore, the functional fine particles can exhibit their performance to the maximum.

  After introducing the functional fine particles, it is also preferable to laminate a porous film layer on the surface of the porous coating layer for the purpose of improving the surface design, touch, and wear resistance. What is suitably used as the porous film layer includes those made of a polymer elastic body such as a polyurethane resin similar to those suitable for the porous coating layer. As a forming method, there is a method of preparing a porous film in advance and laminating it on the surface of the porous coating layer, and a method of laminating a non-porous film on the surface of the porous coating layer and then forming a porous film, Any of them can be adopted depending on the purpose. As the former method, a polymer elastic body is applied on a release paper or a base film in a liquid state such as a solution, a dispersion, or a melt, and solidified in a porous state by the above-described method. Before or after lamination, both sides are ground by buffing, etc., or the applied polymer elastic body is solidified in a non-porous state and punched with a needle etc. to open through holes Can be laminated and integrated on the surface of the porous coating layer via an adhesive layer. As the latter method, embossing is performed by laminating a non-woven sheet made of a polymer elastic body formed by a melt blown method or a spunbond method on the surface of the porous coating layer, and then heating it above the softening temperature of the polymer elastic body. The method of embossing with a roll etc. is mentioned. As a method of laminating the non-woven sheet, a non-woven sheet prepared in advance is laminated and integrated on the surface of the porous coating layer via an adhesive layer, or the non-woven sheet is directly formed on the surface of the porous coating layer. A method of pressing the polymer elastic body while it is in a semi-molten state, if necessary, can be mentioned. When a porous film or a non-woven sheet is laminated on the surface of the porous coating layer, when the adhesive layer is interposed, the adhesive should be removed from the porous film or non-woven fabric so as not to block the pores on the surface of the porous coating layer. It is preferably applied to the woven sheet side or the porous coating layer side in a discontinuous state such as a dot shape or a stripe shape. The adhesive is not particularly limited as long as it has an effect of sufficiently bonding the polymer elastic bodies to each other, but a polyurethane-based adhesive, a polyamide-based adhesive, or the like can be preferably used.

  In the present invention, the type of functional fine particles is not particularly limited, and is an antibacterial agent mainly composed of a metal or organic compound containing silver, copper or the like, activated carbon, a deodorant mainly composed of metal oxide, or a negative ion generator. Any of the above-described tourmaline, a hygroscopic agent, a ceramic that generates far-infrared rays, etc., in the form of a fine powder having a particle size that can be introduced into the pores of the porous coating layer can be used. By reducing the average particle size, the functional fine particles can increase the total surface area per unit mass, that is, the specific surface area. Therefore, the functional fine particles can function more efficiently when viewed alone. It is a form. Therefore, since the upper limit of the average particle diameter of the functional fine particles may be appropriately set according to the target functional efficiency, there is no upper limit as an absolute value of the average particle diameter in the present invention. In this case, the use of functional fine particles of less than 5 μm is preferable because it is easy to obtain the display efficiency required in general for various functionalities, more preferably 3 μm or less, and even more preferably 1 μm or less. In the easiness of obtaining the display efficiency, the lower limit of the average particle size of the functional fine particles is not particularly set, and is not particularly limited in the present invention. It is easy to aggregate, and as a standard, 0.001 μm or more is preferable. However, the size in a form that exists stably when charged into the porous coating layer by the above-described method, that is, the secondary particle size, which is generally the size after aggregation, is the porous material to be charged. Since it must be sufficiently smaller than the size of the opening portion of the coating layer, it is preferable to use functional fine particles having an average particle diameter of 1/5 or less with respect to the average diameter of the opening portion as a guide. Preferably, it is 1/10 or less. In other words, on the surface of the porous coating layer when the pores having an average diameter that is 5 times or more larger than the average particle diameter of the functional fine particles set in accordance with the target functional efficiency are introduced. It is preferable to provide, more preferably 10 times or more.

By finishing the surface of the porous coating layer obtained as described above or the surface of the porous film layer by the following method as necessary, various appearances such as various natural leather tones and geometric patterns It can be set as the functional leather-like sheet | seat which has.
As the finishing treatment, an uncolored or colored ink comprising a polymer elastic body, a colorant such as a pigment or a dye, and a solvent or a dispersion medium, if necessary, a gravure coater, a reverse roll coater, a screen coater There is a paint finish that is transferred to the finished surface using a method to form a target clear layer or colored layer. In addition, there is an embossing finish in which embossing rolls such as the desired natural leather tone are embossed to reproduce the texture on the finished surface.
In the above finishing process, care must be taken not to block the necessary opening. By leaving the necessary openings, it is possible to ensure that functional fine particles such as antibacterial agents and deodorants are in direct contact with the atmosphere, so that the performance inherent in the fine particles can be expressed effectively without loss. be able to.
When performing the above-described embossing finish treatment, the treatment temperature and treatment pressure are lowered, and the embossing roll surface unevenness is transferred more faithfully, that is, for the purpose of improving the embossing property, It is preferable to appropriately set the composition, molecular weight, and the like of the elastic polymer constituting the finishing layer of the embossed surface or the coating layer.

The apertures formed on the surface of the porous coating layer or the surface of the porous film layer must have an average diameter of 1 to 100 μm, preferably 3 to 95 μm, more preferably 5 to 90 μm. The larger the average diameter of the apertures, the easier it is to express the functionality of the fine particles. However, if the average diameter exceeds 100 μm, the appearance will be conspicuous, and it is not preferable for general evaluation in the intended use. In addition to the problem that water and other pollutants are easily infiltrated, and the surface strength is significantly reduced, it is possible to form an open surface that can be formed in terms of appearance and surface strength per surface area of the leather-like sheet. When the total area of the pores is limited, a serious problem that the surface area inside the pores where the functional fine particles can be supported is significantly limited becomes obvious. On the other hand, if the average diameter of the apertures is made smaller than 1 μm, the required aperture area can be secured if a huge number of apertures are provided per unit area, but the total area is secured. However, since the resistance between the hole wall surface from the opening to the functional fine particles and the medium, for example, air, is remarkably increased and the moving speed is limited, the functionality cannot be expressed quickly. . Therefore, the average diameter of the apertures should be as large as possible within the above range, in view of the balance between the target level in terms of quality such as appearance and surface strength and the amount of functional fine particles supported to obtain the target level in terms of function. It is preferable to set.
Furthermore, it is preferable that the pores on the surface of the functional leather-like sheet of the present invention are distributed in an amount of 5 to 1000 / cm ² from the viewpoint of not reducing the appearance of the surface and the effect of the functional fine particles. it is more preferable that pieces / cm ² distribution, it is more preferable that 20 to 500 pieces / cm ² distribution.
For this reason, when forming an opening part in the surface, it is necessary to select processing conditions suitably, observing the surface. For example, in the case of buffing processing, it is the sandpaper count, rotation speed, pressure, processing speed, number of times of processing, etc., in the case of paint finishing processing, ink composition and concentration, coating amount, drying conditions, number of times of processing, etc. In the case of an embossing finishing process, the surface temperature, pressure, processing speed, number of processes, and the like.

Next, embodiments of the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples. In the examples, parts and% are based on mass unless otherwise specified.
[Average diameter of aperture]
The surface of the obtained leather-like sheet is photographed with an electron microscope, the average area of 10 arbitrary openings is obtained, and the average area is defined as the diameter of the circle.

Example 1
Nylon 6 chips and high-fluidity low-density polyethylene chips are mixed at a mass ratio of 50/50, and the island component is nylon and the sea component is polyethylene and the sea island-type fiber is averaged with an average number of islands of 600. did. The obtained sea-island fiber was drawn, crimped, and cut to obtain a staple having an average fineness of 3.5 dtex and a cut length of 51 mm. By spreading the staple card, after the web by a cross wrapper scheme, laminated, then fault by needle punching at 980 punches / cm ² of punch numbers using a felt needle barb with only one place in the needle Combined treatment was performed to obtain a nonwoven fabric having a basis weight of 450 g / m ² . After heating the nonwoven fabric to 120 ° C., the surface is smoothed by pressing with a cooling roll, and further impregnated with a dimethylformamide (abbreviated as DMF) solution of a 13% polyester-ether polyurethane, and wetted in a DMF aqueous bath. It solidified and washed with hot water to remove DMF. Next, the sea component in the staple is extracted and removed in a 100 ° C. toluene bath, and the thickness is 1.1 mm, which is composed of a nonwoven fabric made of a bundle of nylon ultrafine fibers having an average fineness of 0.05 dtex and polyurethane applied to the inside. A fibrous substrate was obtained.
After applying 500 g / m ² of a DMF solution of a polyester-ether polyurethane having a concentration of 20% on one side of this fibrous substrate, the polyurethane was solidified by dipping in a water / DMF = 90/10 DMF aqueous solution bath. A porous coating layer having a thickness of 200 μm was formed.
The surface of this porous coating layer is buffed to remove about 0.05 mm in thickness, various holes with an average diameter of 1 to 500 μm are distributed on the surface, and an opening portion with an average diameter of 89 μm is provided, The antibacterial agent (average particle diameter 2 μm) of the following composition was applied with a gravure roll 30 g / m ² and dried, and the antibacterial agent was rubbed into the hole from the aperture. When the porous coating layer was observed with an electron microscope, it was confirmed that the antibacterial agent was present in the pores without being contained in the resin constituting the porous coating layer.
Dispersion: AIS-NAZ320 (manufactured by Catalytic Chemical Industry Co., Ltd.) 5 parts
100 parts of water

Next, a melt blown nonwoven fabric having a basis weight of 25 g / m ^{2 made} of polyester polyurethane was bonded to the surface of the porous coating layer using a DMF solution of polyester polyurethane as an adhesive. To bond the meltblown nonwoven fabric, first apply the adhesive to the surface of the porous coating layer in a discontinuous manner using a gravure roll, then immediately laminate the meltblown nonwoven fabric while adjusting the tension to prevent wrinkles from entering and dry it. Thus, the pores on the surface of the porous coating layer were not significantly blocked.
A black ink, which is a DMF solution of polyester polyurethane mixed with carbon black, is applied to the surface of the bonded meltblown nonwoven fabric at 30 g / m ² by gravure roll, dried and then transferred to 160 ° C. The functional leather-like sheet of the present invention was obtained by embossing with a natural leather-like embossing roll having a fine uneven pattern.
In the obtained functional leather-like sheet, various holes having an average diameter of 1 to 30 μm are distributed on the surface about 100 to 200 holes / cm ^2, and there are 13 μm holes in the average diameter. The antibacterial property evaluated for the above is comparable to the performance of the rubbed amount of the antibacterial agent alone, and also has a soft texture and natural leather-like appearance as a leather-like sheet. It was a very suitable material for applications such as shoes and bags.

Example 2
In Example 1 above, the surface of the porous coating layer was buffed to remove about 0.04 mm in thickness, and various pores having an average diameter of 1 to 400 μm were distributed on the surface, and an average diameter of 85 μm was opened. A hole is provided, and a dispersion of 30 g / m ² of tourmaline fine powder (average particle size 0.7 μm) having the following composition is applied with a gravure roll and dried, and the tourmaline fine powder is rubbed into the hole from the opening. It is. When the porous coating layer was observed with an electron microscope, it was confirmed that the fine powder was present in the pores without being contained in the resin constituting the porous coating layer.
Dispersion: Tourmaline fine powder 10 parts
90 parts of water

Next, polyester-based polyurethane was sprayed on the surface of the porous coating layer by a melt blown method, and a melt blown nonwoven fabric having a basis weight of 30 g / m ² was laminated on the surface of the porous coating layer.
Lightly brown ink, which is a DMF solution of polyester polyurethane mixed with iron oxide (valve) and titanium oxide, is applied to the surface of the laminated meltblown nonwoven fabric by applying 30g / m ^{2 with} a gravure roll and drying. Next, the functional leather-like sheet of the present invention was obtained by embossing with a natural leather-like embossing roll having a slightly larger uneven pattern than that of Example 1 heated to 160 ° C. and further mechanically kneading.
In the obtained functional leather-like sheet, various holes having an average diameter of 1 to 35 μm are distributed on the surface of about 100 to 200 holes / cm ^2, and there are openings having an average diameter of 18 μm. The amount of negative ions evaluated was about the same as the performance of the rubbed amount of tourmaline fine powder alone, and it also has a soft texture and natural leather-like appearance as a leather-like sheet. It was a material that was very suitable for applications such as furniture and exterior designs for electronic devices.

Example 3
In Example 1, the sea component was extracted and removed, and then the back surface was buffed and dyed with a blue-black dye to obtain a fibrous substrate having a thickness of 0.7 mm. A porous coating layer was formed on one side of this fibrous substrate in the same manner as in Example 1, buffed to provide an opening, and an antibacterial agent was rubbed into the hole from the opening.

A DMF solution of polyester polyurethane is applied on a polyethylene film, solidified in a DMF aqueous solution bath of water / DMF = 70/30, and then 30 holes / cm ² having an average diameter of 0.35 mm are formed by punching. Thus, a porous film having a thickness of 0.2 mm was prepared. The obtained porous film was bonded to the surface of the porous coating layer rubbed with the antibacterial agent, and the polyethylene film was peeled off.
Black ink was transferred to the surface of the laminated porous film in the same manner as in Example 1, and then embossed with a natural leather-like embossed roll with a fine uneven pattern heated to 165 ° C., and further subjected to mechanical stagnation treatment. The functional leather-like sheet of the present invention was obtained.
The obtained functional leather-like sheet has various pores with an average diameter of 30 to 80 μm distributed on the surface of about 5 to 20 holes / cm ^2, and there are openings with an average diameter of 48 μm. The antibacterial property evaluated with respect to the performance of the antibacterial agent rubbed in is almost inferior to the performance of a single substance, and also has a soft texture and natural leather-like appearance as a leather-like sheet. Yes, it was a very suitable material for applications such as clothing and vehicle interiors.

Comparative Example 1
In Example 1, 500 g / m ² of a polyurethane solution mixed with an antibacterial agent on one side of a fibrous base material was applied and then immersed in a DMF aqueous bath of water / DMF = 90/10 to obtain polyurethane. It was solidified to form a porous coating layer having a thickness of about 200 μm. When this porous coating layer was observed with an electron microscope, it was confirmed that the antibacterial agent was present inside the resin constituting the porous coating layer.
Solution: 20 parts of polyester polyurethane
AIS-NAZ320 (manufactured by Catalyst Kasei Kogyo Co., Ltd.) 0.3 part
DMF 79.7 parts The surface of this porous coating layer was buffed to remove about 0.05 mm in thickness, and various holes with an average diameter of 5 to 500 μm were distributed on the surface. A hole was provided. Black ink was transferred to the surface of the porous coating layer provided with the apertures in the same manner as in Example 1, and then embossed with a natural leather-like embossing roll with a fine uneven pattern heated to 160 ° C., A functional leather-like sheet was obtained.
The obtained functional leather-like sheet has about 50 to 150 holes / cm ² of various holes having an average diameter of 10 to 40 μm distributed on the surface, and there are openings having an average diameter of 25 μm. When the antibacterial property was evaluated, the amount of the antibacterial agent used was remarkably inferior to the performance exhibited by a single substance, and the antibacterial property was hardly exhibited. Moreover, when the abrasion resistance of the surface was evaluated, the surface strength was weak, such as being significantly reduced from that of Example 1, and the texture was harder than that of Example 1.

Comparative Example 2
In Example 1, the porous coating layer surface provided with the opening portion by buffing processing, the polyurethane solution 75 g / m 2 having the following ^composition, six coated by a gravure roll, transferred by drying. When the porous coating layer was observed with an electron microscope, it was confirmed that the antibacterial agent was adhered to the porous coating layer in a state in which the antibacterial agent was partially included in the surface and the pore wall in the vicinity of the opening.
Solution: Polyester polyurethane 8 parts
AIS-NAZ320 (catalyst chemical industry Co., Ltd.) 2 parts
45 parts of DMF
45 parts of cyclohexanone Black ink was transferred to the surface of the porous coating layer to which the antibacterial agent had been transferred in the same manner as in Example 1, and then embossed with a natural leather-like embossing roll with a fine unevenness pattern heated to 160 ° C. A functional leather-like sheet was obtained.
The obtained functional leather-like sheet has about 50 to 150 holes / cm ² with various holes having an average diameter of 5 to 30 μm on the surface, and there are 15 μm apertures on the surface side. When the antibacterial property was evaluated, the amount of the antibacterial agent used was remarkably inferior to the performance exhibited by itself. Moreover, when the abrasion resistance of the surface was evaluated, the surface strength was weak, such as being significantly reduced from that of Example 1, and the texture was harder than that of Example 1.

Comparative Example 3
In Example 1, the antibacterial agent dispersion liquid is bonded to the porous coating layer without rubbing the meltblown nonwoven fabric, black ink is transferred in the same manner as in Example 1, and then embossed using the same embossing roll. In addition, by setting the temperature to 170 ° C. and slowing down the processing speed, the leather-like leather with a silver surface having almost the same texture as that of the functional leather-like sheet of Example 1 but having almost no openings on the surface. A sheet was produced. This leather-like sheet with a silver surface was immersed in an antibacterial agent dispersion having the following composition, squeezed at a liquid content of 80%, and finally dried.
When the obtained leather-like sheet with a silver surface was observed with an electron microscope, it was confirmed that most of the antibacterial agent was applied to the bundle of ultrafine fibers in the fibrous base layer or the polyurethane surface. This leather-like sheet with a silver surface had almost no antibacterial property on the surface side, and the texture was a little bit stiff compared to that of Example 1.

Comparative Example 4
A leather-like sheet with a silver surface was obtained in the same manner as in Example 1, except that the dispersion medium of the antibacterial agent dispersion liquid rubbed into the porous coating layer was changed to one containing DMF equivalent to water.
When the obtained leather-like sheet with a silver surface is observed with an electron microscope, most of the applied antibacterial agent is attached in the vicinity of the opening portion of the porous coating layer or contained in the resin inside the pore wall. It has been confirmed that Compared to the antibacterial leather-like sheet of Example 1, this silver-faced leather-like sheet did not look much inferior in appearance or texture, but the antibacterial properties evaluated on the surface side exhibited the amount of antibacterial agent used alone. The performance was extremely poor.

  The functional leather-like sheet of the present invention can be used as long as it is used in the same manner as a conventional leather-like sheet, and more preferably various products that have opportunities for human contact, such as shoes, bags, wallets, It can be used as a material for furniture, clothing, gloves, belts, vehicle interiors, balls, and exterior designs for electronic devices.

It is a cross-sectional schematic diagram of the functional leather-like sheet of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fiber base layer 2 Porous layer coating layer 3 Functional fine particle 4 Opening part

Claims (6)

Resin in which functional fine particles constitute a porous coating layer in the pores of the porous coating layer in a functional leather-like sheet comprising a fibrous base layer, a porous coating layer formed on at least one side thereof, and functional fine particles A functional leather-like sheet, which is present without being contained therein, and has an aperture having an average diameter of 1 to 100 μm on the surface of the functional leather-like sheet. 2. The functional leather-like sheet according to claim 1, wherein the fibrous base layer comprises a nonwoven fabric mainly composed of ultrafine fibers having an average fineness of 0.3 dtex or less or a fiber bundle and a polymer elastic body provided therein. The functional leather-like sheet according to claim 1 or 2, wherein a porous film layer is laminated on the surface of the porous coating layer. A treatment liquid in which a porous coating layer having pores having an average diameter of 1 to 100 μm is formed on at least one surface of a fibrous base layer, and functional fine particles are dispersed in a non-solvent of a resin forming the porous coating layer. A method for producing a functional leather-like sheet, wherein the porous coating layer is introduced into the pores from the aperture and then the non-solvent is removed. The functional leather-like sheet according to claim 4, wherein a surface portion of the porous coating layer laminated on at least one surface of the fibrous base layer is removed to form a porous coating layer having pores having an average diameter of 1 to 100 µm. Manufacturing method. The functional leather-like sheet according to claim 4 or 5, wherein a porous film layer having an aperture having an average diameter of 1 to 100 µm is further laminated on the surface of the porous coating layer having an aperture having an average diameter of 1 to 100 µm. Production method.

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