JP2014019983A - Sheet-like object and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-like object that has favorable appearance quality and has high strength; and a production method of the same.SOLUTION: A sheet-like object includes: a nonwoven cloth consisting of a fiber having a mean single fiber diameter of 0.3-30 μm; and a polymer elastic body included in an inside of the same, and when trisection is performed by a surface perpendicular to a thickness direction of the sheet-like object to A layer, B layer and C layer, average diameters of single fiber cross sections existing in respective cross sections parallel to a thickness direction are assumed to be a, b, c respectively, the following relational expression is satisfied. a<b<c ( A layer neighbors with B layer in a thickness direction, B layer neighbors with C layer in a thickness direction.)

Description

  The present invention relates to a sheet material having a good appearance quality and a high strength, and a method for producing the same.

  A leather-like sheet-like material mainly composed of ultrafine fibers and a polymer elastic body has excellent characteristics not found in natural leather, and its use has been expanded year by year for apparel, chair upholstery and automotive interior materials. In particular, for skin materials such as car seats and chairs, a high-strength leather-like sheet that can withstand repeated use over a long period of time is required.

  In order to deal with such problems, there is a method of making an artificial leather having high strength, low elongation, and flexibility by integrating a woven or knitted fabric inside or on one side of the nonwoven fabric (Patent Document 1). By using this method, an artificial leather having good mechanical properties can be obtained. However, when the woven or knitted fabric and the nonwoven fabric are entangled and integrated by the needle punch, the woven or knitted fabric is damaged by the needle. May not be able to fully utilize the mechanical properties inherent to. In addition, if this damage is anticipated and the woven or knitted fabric is densified to supplement the strength, the woven or knitted fabric has increased rigidity, and a flexible artificial leather cannot be obtained.

  As a method for enhancing the mechanical properties of woven and knitted fabrics, woven and knitted fabrics are composed of high-strength fibers such as high-strength polyvinyl alcohol-based synthetic fibers (high-strength vinylon fibers) and wholly aromatic polyamide (aramid) fibers. An artificial leather base that is intertwined with each other has been proposed (Patent Document 2). However, in this case as well, if the needle barb is in the relationship of hooking the knitted fabric during needle punching, not only will the fibers constituting the woven or knitted fabric be damaged, but the wear of the needle will be accelerated rapidly. Therefore, there is a problem that a long sheet cannot be processed stably.

  Further, an invention has been proposed in which a structure in which the ultrafine fibers are partially restrained at an unsealed portion by not eluting all the sea components of the sea-island type ultrafine fibers constituting the leather-like sheet (Patent Document 3). However, in this manufacturing method, the unsealed portion is also exposed on the sheet surface, so that there is a problem that the appearance quality is lowered.

  Furthermore, a leather-like sheet material composed of two nonwoven fabric layers having different average fineness diameters has been proposed (Patent Document 4). However, there is a problem that wrinkles are likely to occur in the leather-like sheet-like material because distortion due to a difference in shrinkage stress and rigidity occurs at the interface between two layers of nonwoven fabrics having different average fineness diameters.

JP-A-62-78281 JP-A-2005-240197 JP 2008-285807 A JP 2002-180383 A

  An object of the present invention is to provide a sheet material having a good surface appearance and high strength.

  The sheet-like material of the present invention is a non-woven fabric made of fibers having an average single fiber diameter of 0.3 to 30 μm, and a sheet-like material made of a polymer elastic body contained therein, and the thickness direction of the sheet-like material When the average diameter of the cross section of the single fiber existing in the cross section parallel to the thickness direction is a, b, c when the A layer, the B layer, and the C layer are divided into three equal parts on the plane perpendicular to It is a sheet-like object characterized by satisfying.

a <b <c
(The A layer is adjacent to the B layer in the thickness direction, and the B layer is adjacent to the C layer in the thickness direction.)
Moreover, the manufacturing method of the sheet-like thing of this invention impregnates the nonwoven fabric which consists of an ultrafine fiber expression type composite fiber with alkaline aqueous solution, and performs 40-130 degreeC heat processing in the atmosphere of humidity 0-60%. It is the manufacturing method of the sheet-like material characterized.

  According to the present invention, a sheet having a good surface appearance and a high strength can be obtained.

  The sheet-like material of the present invention is a sheet-like material composed of a nonwoven fabric composed of ultrafine fibers and a polymer elastic body contained therein.

  The sheet-like material in the present invention has a smooth touch and an excellent lighting effect in a nap-like appearance like suede or nubuck like natural leather.

  The nonwoven fabric used in the present invention may be either a short fiber nonwoven fabric or a long fiber nonwoven fabric, but a short fiber nonwoven fabric is preferably used in terms of texture and quality.

  When the fiber length is preferably 25 mm or more, a sheet-like material having excellent wear resistance can be obtained by entanglement. In addition, by making the fiber length preferably 90 mm or less, a sheet-like product having a better texture and quality can be obtained. The fiber length of the short fibers in the short fiber nonwoven fabric is more preferably 30 to 70 mm.

  In the present invention, it is a preferable aspect that the nonwoven fabric has a structure in which fiber bundles (fiber bundles) are intertwined. When the fibers are intertwined in a bundle state, the strength of the sheet-like material is improved. The nonwoven fabric of such an embodiment can be obtained by causing the ultrafine fibers to develop after entanglement of the ultrafine fiber-expressing fibers in advance.

  The nonwoven fabric can contain a woven fabric or a knitted fabric for the purpose of improving the strength. The average single fiber diameter of the fibers constituting the woven or knitted fabric is preferably about 0.3 to 20 μm.

The apparent density of the nonwoven fabric is preferably 0.10 to 0.60 g / cm ³ . When the apparent density of the nonwoven fabric is within the above range, the structure of the nonwoven fabric becomes uniform, and it is possible to avoid an extremely large variation in quality in the area direction, and the physical properties and texture of the obtained sheet-like material are good. . The nonwoven fabric may be subjected to shrinkage treatment by warm water or steam treatment in order to improve the fineness of the fibers. Also in this case, in order to obtain a uniform and dense fiber entangled structure, the apparent density is preferably in the above range. The apparent density of the nonwoven fabric is more preferably 0.15 to 0.55 g / cm ³ .

  As fibers constituting the nonwoven fabric, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid, polyamides such as 6-nylon and 66-nylon, acrylic, polyethylene, polypropylene, and thermoplastic cellulose are melted. A fiber made of a thermoplastic resin that can be spun can be used. Among these, polyester fibers are preferably used from the viewpoints of strength, dimensional stability, and light resistance. Moreover, the nonwoven fabric may be configured by mixing fibers of different materials.

  The cross-sectional shape of the fibers constituting the nonwoven fabric may be a round cross section, but may be a polygonal shape such as an ellipse, a flat shape, or a triangle, or a modified cross section such as a sector shape or a cross shape.

  In the present invention, a polyurethane liquid is impregnated as a polymer elastic body contained in the nonwoven fabric so that the polyurethane is present in the interior space of the nonwoven fabric.

  The polyurethane used in the present invention may be solvent-based or water-dispersed. However, the water-dispersed polyurethane is preferred from the viewpoint of environmental protection because it does not require the use of an organic solvent.

  As the water-dispersed polyurethane used in the present invention, those obtained by reaction of a polymer diol, an organic diisocyanate and a chain extender are preferable.

  As the polymer diol, for example, a polycarbonate diol, a polyester diol, a polyether diol, a silicone diol, and a fluorine diol may be employed, and a copolymer combining these may be used. Of these, polycarbonate diols and polyether diols are preferably used from the viewpoint of hydrolysis resistance. From the viewpoints of light resistance and heat resistance, it is preferable to use a polycarbonate diol and a polyester diol. From the viewpoint of all the balances of hydrolysis resistance, heat resistance and light resistance, a polycarbonate diol and a polyester diol are more preferable, and a polycarbonate diol is particularly preferable.

  The polycarbonate-based diol can be produced by an ester exchange reaction between an alkylene glycol and a carbonate ester, or a reaction between phosgene or chloroformate ester and an alkylene glycol.

  Examples of alkylene glycols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol. Chain alkylene glycol, branched alkylene glycol such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, Alicyclic diols such as 1,4-cyclohexanediol, aromatic diols such as bisphenol A, glycerin, trimethylolpropane, and pentaerythritol. Either a polycarbonate diol obtained from a single alkylene glycol or a copolymerized polycarbonate diol obtained from two or more types of alkylene glycols may be used.

  Examples of the polyester diol include polyester diols obtained by condensing various low molecular weight polyols and polybasic acids.

  Examples of the low molecular weight polyol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, and 2,2-dimethyl-1,3-propane. Diol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, and One kind or two or more kinds selected from cyclohexane-1,4-dimethanol can be used. Further, addition products obtained by adding various alkylene oxides to bisphenol A can also be used.

  Polybasic acids include, for example, succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and hexahydro One kind or two or more kinds selected from isophthalic acid can be mentioned.

  Examples of polyether-based diols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymerized diols combining them.

  The number average molecular weight of the polymer diol is preferably 500 to 4000. By making the number average molecular weight 500 or more, more preferably 1500 or more, it is possible to prevent the texture from becoming hard, and by making the number average molecular weight 4000 or less, more preferably 3000 or less, the strength as polyurethane is increased. Can be maintained.

  Examples of the organic diisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and aromatic diisocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate, and combinations thereof. May be used. Among these, aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and isophorone diisocyanate are preferably used from the viewpoint of light resistance.

  As the chain extender, amine chain extenders such as ethylenediamine and methylenebisaniline and diol chain extenders such as ethylene glycol can be used. Moreover, the polyamine obtained by making polyisocyanate and water react can also be used as a chain extender.

  Polyurethane may be used in combination with a crosslinking agent for the purpose of improving water resistance, abrasion resistance, hydrolysis resistance and the like. The cross-linking agent may be an external cross-linking agent added as a third component to the polyurethane, or may be an internal cross-linking agent that introduces a reaction point that becomes a cross-linked structure in advance in the polyurethane molecular structure. It is preferable to use an internal crosslinking agent from the viewpoint that the crosslinking points can be formed more uniformly in the polyurethane molecular structure and the reduction in flexibility can be reduced.

  As the crosslinking agent, compounds having an isocyanate group, an oxazoline group, a carbodiimide group, an epoxy group, a melamine resin, a silanol group, and the like can be used.

  Moreover, it is preferable that the polyurethane used by this invention has a hydrophilic group in molecular structure. By having a hydrophilic group in the molecular structure, the dispersion / stability of the water-dispersed polyurethane can be improved.

  Examples of the hydrophilic group include cationic systems such as quaternary amine salts, anionic systems such as sulfonates and carboxylates, nonionic systems such as polyethylene glycol, and combinations of cationic and nonionic systems, and anionic and nonionic systems. Any hydrophilic group of the combination of systems can be employed.

  Among these, nonionic hydrophilic groups that are free from yellowing caused by light and harmful effects caused by a neutralizing agent are particularly preferable.

  That is, in the case of an anionic hydrophilic group, a neutralizing agent is required. For example, the neutralizing agent is a tertiary amine such as ammonia, triethylamine, triethanolamine, triisopropanolamine, trimethylamine and dimethylethanolamine. In some cases, amines are generated and volatilized by the heat generated during film formation and drying, and released outside the system. For this reason, in order to suppress the release of air and the deterioration of the working environment, it is essential to introduce a device for recovering volatile amines. In addition, if the amine does not volatilize by heating and remains in the final product sheet, it may be discharged to the environment when the product is incinerated. On the other hand, in the case of a nonionic hydrophilic group, since no neutralizing agent is used, it is not necessary to introduce an amine recovery device, and there is no fear of remaining amine in the sheet. Further, when the neutralizing agent is an alkali metal such as sodium hydroxide, potassium hydroxide or calcium hydroxide, or a hydroxide of an alkaline earth metal, the polyurethane part becomes alkaline when wetted with water. In the case of a nonionic hydrophilic group, since a neutralizing agent is not used, there is no need to worry about deterioration due to hydrolysis of polyurethane.

  It is preferable that content of the polyurethane with respect to a sheet-like material is 1-40 mass%. By setting the ratio of polyurethane to 1% by mass or more, more preferably 3% by mass or more, it is possible to obtain sheet strength and to prevent the fibers from falling off. Further, by setting the polyurethane content to 40% by mass or less, more preferably 35% by mass or less, it is possible to prevent the texture from becoming hard and to obtain a good appearance quality.

  In the present invention, when the A layer, the B layer, and the C layer are divided into three equal parts on a plane perpendicular to the thickness direction of the sheet-like material, the average diameter of the single fiber cross section existing in the cross section parallel to the respective thickness direction is a , B, and c satisfy the following relational expressions.

a <b <c
Here, the A layer is adjacent to the B layer in the thickness direction, and the B layer is adjacent to the C layer in the thickness direction.

  When the A layer having a small average single fiber diameter is the product surface and the C layer is the back surface, the average single fiber diameter of the product surface is small, resulting in a good surface appearance, and the back surface has a large average single fiber diameter. The entanglement between them is strong, and the physical properties of the sheet-like material become strong, which is preferable. When the average single fiber diameter is the same for all of the A layer, B layer, and C layer, the surface appearance is good when the average single fiber diameter is small, but the entanglement between the fibers is weak, so the physical properties are weak. When the average single fiber diameter is large, the entanglement between the fibers becomes strong and the physical property becomes a sheet-like material, but the surface appearance becomes rough and does not become a good surface appearance with a high-class feeling. In addition, when the A layer and the C layer are in direct contact with each other, wrinkles are generated due to distortion such as a difference in shrinkage between the A layer and the C layer in the manufacturing process, and the surface appearance is deteriorated, but between the A layer and the C layer. By having the B layer having an average single fiber diameter in the middle, the strain between the A layer and the C layer in the production process does not occur, the generation of wrinkles is suppressed, and a good appearance quality can be obtained. .

  The average single fiber diameter of the fiber which comprises a sheet-like material is 0.3-30 micrometers. The average single fiber diameter a of the A layer is preferably 0.3 to 7 μm, which is the average single fiber diameter of the island component of the sea-island fiber in the manufacturing method described later, and the average single fiber diameter c of the C layer is in the manufacturing method described later. It is preferable that it is 12-30 micrometers which is an average single fiber diameter of a sea island fiber.

Next, the manufacturing method of the present invention will be described.
It is a preferable aspect that the fibers of the nonwoven fabric constituting the sheet-like material of the present invention are fibers obtained from ultrafine fiber expression type fibers. By using the ultrafine fiber expression type fiber, a form in which the fiber bundles are entangled can be stably obtained.

  The average single fiber diameter of the ultrafine fiber expression type fiber is preferably 12 to 30 μm.

  As ultra-fine fiber expression type fiber, two-component thermoplastic resins with different solvent solubility are used as sea component / island component, and island component is made into ultra-fine fiber by dissolving and removing the sea component using solvent etc. Alternatively, a two-component thermoplastic resin may be alternately disposed in a radial or multilayer manner on the fiber cross section, and a peelable composite fiber that is split into ultrafine fibers by separating and separating each component may be employed. Among these, the sea-island type fibers can be preferably used also from the viewpoint of the flexibility and texture of the sheet-like material because an appropriate void can be imparted between the island components, that is, between the ultrafine fibers, by removing the sea components. .

  For the sea-island type fiber, a sea-island type compound base is used, and the sea-island type composite fiber that spins the sea component and the island component by mutual arrangement and the sea component and the island component are mixed and spun. Although there are spun fibers, sea-island type composite fibers are preferably used from the viewpoint that ultrafine fibers having a uniform fineness can be obtained, and that a sufficiently long ultrafine fiber can be obtained and contribute to the strength of the sheet-like material.

  As the sea component of the sea-island fiber, copolymerized polyester obtained by copolymerizing sodium sulfoisophthalate or polyethylene glycol, polylactic acid, polyvinyl alcohol, or the like can be used. Among them, copolymerized polyester and polylactic acid obtained by copolymerizing alkali-decomposable sodium sulfoisophthalate, polyethylene glycol, or the like are preferably used because sea island-type fibers can be stretched and contracted in hot water.

  It is preferable that the average single fiber diameter of the fiber obtained from the island component of the sea-island fiber is 0.3 to 7 μm. By setting the average single fiber diameter to 7 μm or less, preferably 6 μm or less, more preferably 5 μm or less, it is possible to obtain a sheet-like product having excellent flexibility and napping quality. On the other hand, when the average single fiber diameter is 0.3 μm or more, preferably 0.7 μm or more, more preferably 1 μm or more, dispersion of bundle fibers during napping treatment such as coloring after dyeing or grinding with sandpaper etc. Excellent in ease and judgment.

  In the nonwoven fabric, needle punching or water jet punching can be employed as a method for entanglement of fibers or fiber bundles.

  The sea removal treatment when sea-island fibers are used as the ultrafine fiber-expressing fibers constituting the nonwoven fabric may be performed before or after applying polyurethane to the nonwoven fabric. If the sea removal treatment is performed before the polyurethane is applied, the polyurethane is in close contact with the ultrafine fibers so that the ultrafine fibers can be strongly gripped, so that the wear resistance of the sheet-like material is improved. On the other hand, when sea removal treatment is performed after polyurethane is applied, voids are generated between the polyurethane and the ultrafine fibers due to the sea components removed from the sea, so the texture of the sheet-like material is not directly gripped by the polyurethane. Becomes flexible.

The sea removal treatment can be performed by immersing the sea-island fiber in a solvent and squeezing it. As the solvent for dissolving the sea component, an alkaline aqueous solution such as sodium hydroxide can be used.
The sea removal treatment is carried out in an atmosphere with a humidity of 0 to 60%, preferably a humidity of 0 to 50%, so that the alkaline aqueous solution migrates and effectively changes the sea removal rate between the inside of the sheet and the surface portion. Can do. Further, by performing heat treatment at a temperature of 40 to 130 ° C., preferably 80 to 130 ° C., sea removal can be promoted.

  In the present invention, polyurethane is applied to the fibrous base material by solidifying it after applying the polyurethane liquid to the fibrous base material, but it is preferable to uniformly apply polyurethane in the thickness direction of the fibrous base material. Therefore, the polyurethane liquid preferably exhibits heat-sensitive coagulation. When the heat-sensitive coagulation property is not exhibited, the polyurethane liquid undergoes a migration phenomenon that concentrates on the surface layer of the nonwoven fabric during dry coagulation, and the texture of the polyurethane sheet tends to be cured. The heat-sensitive coagulation property refers to the property that when the polyurethane liquid is heated, the fluidity of the polyurethane liquid decreases and solidifies when reaching a certain temperature (heat-sensitive coagulation temperature).

  The heat-sensitive coagulation temperature of the polyurethane in the present invention is 40 to 90 ° C. By setting the heat-sensitive coagulation temperature to 40 ° C. or higher, stability during storage of the polyurethane liquid is improved, and adhesion of polyurethane to the machine during operation can be suppressed. Moreover, the migration phenomenon of the polyurethane in a nonwoven fabric can be suppressed because a thermal coagulation temperature shall be 90 degrees C or less.

  In order to set the heat-sensitive coagulation temperature as described above, a heat-sensitive coagulant may be added as appropriate. Examples of the heat-sensitive coagulant include inorganic salts such as sodium sulfate, magnesium sulfate, calcium sulfate, calcium chloride, and radical reactions such as sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutyronitrile, and benzoyl peroxide. Initiators are mentioned.

  Water-emulsion polyurethane liquids are various additives, for example, pigments such as carbon black, flame retardants such as phosphorus, halogen, silicone and inorganic, antioxidants such as phenol, sulfur and phosphorus, UV absorbers such as benzotriazole, benzophenone, salicylate, cyanoacrylate and oxalic acid anilides, light stabilizers such as hindered amines and benzoates, hydrolysis stabilizers such as polycarbodiimides, plasticizers, Contains antistatic agents, surfactants, softeners, water repellents, coagulation modifiers, dyes, preservatives, antibacterial agents, deodorants, fillers such as cellulose particles, and inorganic particles such as silica and titanium oxide You may do it.

  The water-emulsion polyurethane liquid may contain a water-soluble organic solvent in an amount of 40% by mass or less based on the polyurethane liquid in order to improve storage stability and film-forming properties. Therefore, the content of the organic solvent is preferably 1% by mass or less.

  A polyurethane can be coagulated by impregnating, applying, etc., a water emulsion polyurethane liquid to a nonwoven fabric by dry heat coagulation, wet heat coagulation, wet coagulation, or a combination thereof.

  The wet heat coagulation temperature may be equal to or higher than the heat sensitive coagulation temperature of polyurethane, and is preferably 40 to 200 ° C., for example. By setting the wet heat solidification temperature to 40 ° C. or higher, more preferably 80 ° C. or higher, the time to solidification of the polyurethane can be shortened to further suppress the migration phenomenon. On the other hand, heat degradation of polyurethane can be prevented by setting the wet heat solidification temperature to 200 ° C. or lower, more preferably 160 ° C. or lower.

  The temperature of wet coagulation may be higher than the heat-sensitive coagulation temperature of polyurethane, and is preferably 40 to 100 ° C., for example. By setting the temperature of wet coagulation in hot water to 40 ° C. or higher, more preferably 80 ° C. or higher, the time to solidification of polyurethane can be shortened to further suppress the migration phenomenon.

  The dry solidification temperature and the drying temperature are preferably 80 to 160 ° C. By setting the dry solidification temperature and the drying temperature to 80 ° C. or higher, more preferably 90 ° C. or higher, the productivity is excellent. On the other hand, when the dry coagulation temperature and the drying temperature are 180 ° C. or lower, more preferably 160 ° C. or lower, thermal deterioration of the polyurethane can be prevented.

  After polyurethane is applied to the nonwoven fabric, dividing the polyurethane-applied sheet-like material into half or several sheets in the sheet thickness direction is a preferable aspect with excellent production efficiency.

  A lubricant such as a silicone emulsion can be applied to the polyurethane-applied sheet-like material before the raising treatment described later. Moreover, applying an antistatic agent before the raising treatment is a preferable aspect in order to make it difficult for the grinding powder generated from the sheet-like material to be deposited on the sandpaper by grinding.

  In order to form napping on the surface of the sheet-like material, napping treatment can be performed. The raising treatment can be performed by a method of grinding using sandpaper, roll sander or the like.

  The sheet material may be dyed. As a dyeing method, it is preferable to use a liquid dyeing machine because the sheet-like material can be softened by dyeing the sheet-like material and at the same time giving a stagnation effect. If the dyeing temperature is too high, the polyurethane may be deteriorated. Conversely, if the dyeing temperature is too low, the dyeing to the fiber becomes insufficient. In general, the dyeing temperature is preferably from 80 ° C to 150 ° C, more preferably from 110 ° C to 130 ° C.

  The dye can be selected according to the type of fiber constituting the nonwoven fabric. For example, disperse dyes can be used for polyester fibers, acidic dyes or metal-containing dyes can be used for polyamide fibers, and combinations thereof can be used. When dyed with disperse dyes, reduction washing may be performed after dyeing.

  It is also a preferred embodiment to use a dyeing assistant during dyeing. By using a dyeing assistant, the uniformity and reproducibility of dyeing can be improved. In addition, a finishing treatment using a softening agent such as silicone, an antistatic agent, a water repellent, a flame retardant, a light proofing agent, and an antibacterial agent can be performed in the same bath or after dyeing.

  The sheet-like material obtained by the present invention includes furniture, chairs and wall materials, interior materials having a very elegant appearance as a skin material such as seats, ceilings and interiors in vehicle interiors such as automobiles, trains and aircraft, shirts, Jackets, casual shoes, sports shoes, uppers and trims for shoes such as men's shoes and women's shoes, bags, belts, wallets, etc. It can be suitably used as an industrial material.

Hereinafter, although the sheet-like material of the present invention and the manufacturing method thereof will be described more specifically with reference to examples, the present invention is not limited to only these examples. The evaluation methods in the examples are as follows.
[Evaluation method]
(1) Average single fiber diameter The cross section parallel to the thickness direction of a nonwoven fabric or a sheet-like material is observed at a magnification of 2000 using a scanning electron microscope (SEM). The average single fiber diameter is obtained by dividing a nonwoven fabric or a sheet-like material into three equal parts in a plane perpendicular to the thickness direction, randomly selecting circular or nearly elliptical fibers from each, and measuring a total of 100 single fiber diameters. The average value was calculated.

  When the ultrafine fiber constituting the nonwoven fabric or the sheet-like material has an irregular cross section, the diameter of the circumscribed circle of the irregular cross section is defined as the single fiber diameter. In addition, when the circular cross section and the irregular cross section are mixed, or when the fiber sections having greatly different fiber diameters are mixed, 100 are selected and calculated so that the number is the same.

(2) Sea removal rate The sea removal rate is calculated by dividing the decrease in seat weight after sea removal by the total weight of sea components contained in the sheet before sea removal.

[Preparation of polyurethane liquid]
As water emulsion polyurethane resin, heat-sensitive to 100 parts by mass of solid content of carboxylic acid triethylamine salt-containing polycarbonate-based forced emulsification type polyurethane liquid in which polyhexamethylene carbonate diol is applied to polyol and dicyclohexylmethane diisocyanate is applied to isocyanate. 15 parts by mass of sodium sulfate was added as a coagulant, and the whole was adjusted to a solid content of 10% by mass with water, and this was used as a polyurethane liquid.

[Example 1]
As the sea component, polyethylene terephthalate copolymerized with 8 mol% of sodium 5-sulfoisophthalate is used, and as the island component, polyethylene terephthalate is used. The sea component is 45% by mass and the island component is 55% by mass. A sea-island fiber having 1 filament and an average single fiber diameter of 17 μm was obtained. The obtained sea-island fiber was cut into a fiber length of 51 mm to form a staple, a fiber web was formed through a card and a cross wrapper, and a nonwoven fabric was formed by needle punching. When the obtained sea-island type fiber is completely removed from the sea, the average single fiber diameter of the island component is 2.2 μm.

  This nonwoven fabric was immersed in hot water at a temperature of 98 ° C. for 2 minutes to shrink and dried at a temperature of 100 ° C. for 5 minutes. Next, this nonwoven fabric is impregnated with the polyurethane liquid prepared above, treated for 5 minutes in a humid heat atmosphere at a temperature of 100 ° C. and a humidity of 90%, and then dried with hot air at a temperature of 120 ° C. for 5 minutes, The sheet | seat which provided the polyurethane was obtained so that the polyurethane mass with respect to the island component mass of a nonwoven fabric might be 20 mass%. After applying a polymer elastic body to a nonwoven fabric made of sea-island fibers, a portion of the sea components of sea-island fibers is immersed in an aqueous alkaline solution in the nonwoven fabric and subjected to a heat treatment at 120 ° C. in an atmosphere of 20% humidity. A seawater removal sheet with a seawater removal rate of 60% was obtained. After half-cutting the sea removal sheet in the sheet thickness direction, the surface was brushed by grinding using 240 mesh endless sandpaper, then dyed with disperse dye using a circular dyeing machine, and reduced and washed to obtain a sheet-like material It was. When the sheet-like material is divided into three layers of A layer, B layer, and C layer in a plane perpendicular to the thickness direction, the average diameters of the cross-sections of the single fibers existing in the cross sections parallel to the respective thickness directions are respectively a and b. And c satisfy the relational expression of a <b <c (a = 2.2 μm, b = 10 μm, c = 17 μm) to obtain a sheet material having a good appearance quality and high strength. .

[Example 2]
In Example 1, after applying a polymer elastic body to a nonwoven fabric composed of sea-island fibers, an alkaline aqueous solution was immersed in the nonwoven fabric and subjected to a heat treatment at 120 ° C. in an atmosphere of 50% humidity, whereby the sea-island fibers A sheet-like material was obtained in the same manner as in Example 1 except that the sea component was partially removed at a sea removal rate of 70%. When the sheet-like material is divided into three layers of A layer, B layer, and C layer in a plane perpendicular to the thickness direction, the average diameters of the cross-sections of the single fibers existing in the cross sections parallel to the respective thickness directions are respectively a and b. C, a sheet satisfying the relational expression of a <b <c (a = 2.2 μm, b = 9 μm, c = 15 μm) and having good appearance quality, but a value of c−a smaller than that of Example 1 A product was obtained.

[Example 3]
In Example 1, after applying a polymer elastic body to a nonwoven fabric composed of sea-island fibers, an alkaline aqueous solution was immersed in the nonwoven fabric and subjected to a heat treatment at 50 ° C. in an atmosphere of 20% humidity, whereby the sea-island fibers A sheet-like material was obtained in the same manner as in Example 1 except that the sea component was partially removed at a sea removal rate of 80%. When the sheet-like material is divided into three layers of A layer, B layer, and C layer in a plane perpendicular to the thickness direction, the average diameters of the cross-sections of the single fibers existing in the cross sections parallel to the respective thickness directions are respectively a and b. , C satisfy a relational expression of a <b <c (a = 2.2 μm, b = 6 μm, c = 13 μm), and have a good appearance quality, but a value of c−a smaller than that of Example 1 A product was obtained.

[Example 4]
As the sea component, polyethylene terephthalate copolymerized with 8 mol% of sodium 5-sulfoisophthalate is used, and as the island component, polyethylene terephthalate is used. The sea component is 45% by mass and the island component is 55% by mass. A sea-island fiber having 1 filament and an average single fiber diameter of 17 μm was obtained. The obtained sea-island fiber was cut into a fiber length of 51 mm to form a staple, a fiber web was formed through a card and a cross wrapper, and a nonwoven fabric was formed by needle punching. When the obtained sea-island type fiber is completely removed from the sea, the average single fiber diameter of the island component is 2.4 μm.

  This nonwoven fabric was immersed in hot water at a temperature of 98 ° C. for 2 minutes to shrink and dried at a temperature of 100 ° C. for 5 minutes. Subsequently, an alkaline aqueous solution was immersed in the nonwoven fabric and subjected to a heat treatment at 120 ° C. in an atmosphere of 20% humidity to obtain a sea removal sheet having a sea removal rate of 50% from which a part of the sea components of the sea-island fibers was removed. By impregnating the prepared seawater sheet with the polyurethane liquid prepared as described above, treating it for 5 minutes in a humid heat atmosphere at a temperature of 100 ° C. and a humidity of 90%, and then drying with hot air at a temperature of 120 ° C. for 5 minutes. The sheet | seat which provided the polyurethane was obtained so that the polyurethane mass with respect to the island component mass of a nonwoven fabric might be 20 mass%. After applying a polymer elastic body to the sheet, the sheet is cut in half in the thickness direction, the surface is brushed by grinding using a 240 mesh endless sandpaper, and then dyed with a disperse dye using a circular dyeing machine, followed by reduction washing. To obtain a sheet. When the sheet-like material is divided into three layers of A layer, B layer, and C layer in a plane perpendicular to the thickness direction, the average diameters of the cross-sections of the single fibers existing in the cross sections parallel to the respective thickness directions are respectively a and b. C, a relational expression of a <b <c (a = 2.2 μm, b = 10 μm, c = 16 μm) is satisfied, but a sheet-like material having a smaller value of c−a than Example 1 was obtained.

[Comparative Example 1]
In Example 1, after applying a polymer elastic body to a nonwoven fabric composed of sea-island fibers, an alkaline aqueous solution was immersed in the nonwoven fabric and subjected to a heat treatment at 120 ° C. in an atmosphere of 70% humidity, thereby allowing the sea-island fibers to A sheet-like material was obtained in the same manner as in Example 1 except that sea components were completely removed (sea removal rate: 100%). When the sheet-like material is divided into three layers of A layer, B layer, and C layer in a plane perpendicular to the thickness direction, the average diameters of the cross-sections of the single fibers existing in the cross sections parallel to the respective thickness directions are respectively a and b. , C satisfy the relational expression of a = b = c (a = 2.2 μm, b = 2.2 μm, c = 2.2 μm) and have good appearance quality, but from Examples 1, 2, and 3 A sheet with a low c-a value and a low strength was obtained.

Claims (3)

A non-woven fabric made of fibers having an average single fiber diameter of 0.3 to 30 μm, and a sheet-like material made of a polymer elastic body contained therein, and a layer A in a plane perpendicular to the thickness direction of the sheet-like material, Sheets characterized by satisfying the following relational expressions, where a, b, c are the average diameters of the single fiber cross sections existing in the cross sections parallel to the respective thickness directions when the B layers and C layers are equally divided into three layers: State.
a <b <c
(The A layer is adjacent to the B layer in the thickness direction, and the B layer is adjacent to the C layer in the thickness direction.) 2. The sheet-like material according to claim 1, wherein the fiber constituting the B layer contains at least one selected from a copolymerized polyester obtained by copolymerizing sodium sulfoisophthalate and / or polyethylene glycol, and polylactic acid. A method for producing a sheet-like material, comprising impregnating a non-woven fabric composed of ultrafine fiber-expressing composite fibers with an alkaline aqueous solution and performing a heat treatment at 40 to 130 ° C. in an atmosphere of 0 to 60% humidity.