JP2008208498A - Sheet-like article and method for producing sheet-like article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet-like article to which a polyurethane using a non-petroleum-based raw material originated from a plant can be applied and which has a highly flexible touch even under a low environmental load, and to provide a method for producing a highly flexible sheet-like article. <P>SOLUTION: This sheet-like article includes a nonwoven fabric prepared by entangling the bundles of ultra fine fibers having an average single fiber fineness of 0.001-0.5 dtex, and a polymer elastomer consisting mainly of a polyurethane in the inner spaces of the nonwoven fabric. In the sheet-like article, the polyurethane contains a structure originated from a plant in the molecular chain. The method for producing the sheet-like article includes impregnating a nonwoven fabric prepared by entangling the bundles of ultra fine fibers having an average single fiber fineness of 0.001-0.5 dtex with a polymer elastomer consisting mainly of a polyurethane composition containing a skeleton derived from a plant in the molecular chain. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet-like material that has a low environmental load and has a soft texture, and a method for producing the sheet-like material.

  Sheet-like materials mainly composed of ultrafine fibers and polymer elastic bodies have excellent characteristics not found in natural leather, and their use has spread year by year for clothing, chair upholstery, automobile interior materials, and the like. However, in recent years, due to global trends in consideration of the global environment, reduction of environmental load is required for all products, materials, etc., and those with high environmental load tend not to be used. This is no exception in sheet-like materials.

  As one of the efforts to reduce the environmental burden, technological development efforts aiming at preventing global warming and building a recycling-oriented society are being carried out on a global scale. Carbon dioxide is one of the gases that cause global warming, and there is a need to reduce its emissions.

  However, the conventional sheet-like material composed of a combination of a nonwoven fabric such as polyester or polyamide and a polymer elastic body is obtained only from petroleum-based raw materials such as petroleum and coal. For this reason, the amount of carbon dioxide in the atmosphere is increased by burning and discarding to promote global warming. Furthermore, considering that petroleum-based raw materials are limited and non-recyclable resources, the environmental impact of conventional sheet-like materials has been very large.

  On the other hand, plant-derived substances, which are non-petroleum-based raw materials, are renewable resources produced by plants that take in the amount of carbon dioxide in the atmosphere, and the amount of carbon dioxide in the atmosphere does not increase even when burned. From such a so-called carbon neutral concept, there is a movement to use plant-derived substances that are non-petroleum-based raw materials instead of petroleum-based raw materials such as oil and coal.

Examples of the polymer obtained from a plant-derived material that is a non-petroleum-based material include polylactic acid synthesized by obtaining 100% raw material from a crop such as corn, and Patent Document 1 discloses an ultrafine fiber made of polylactic acid and the like. A sheet-like material by a combination of polyurethanes is described. Since polylactic acid is a polymer obtained from a plant-derived substance, application to a sheet-like product is a low environmental load. However, polyurethane is mainly composed of polyols, polyisocyanates, and chain extenders, but since all raw materials are obtained only from petroleum-based raw materials, the environmental load of polyurethane is large. Even in the applied sheet-like material, the environmental load becomes large.
JP 2001-214380 A

  In view of the background of the prior art, the present invention applies a polyurethane using a plant-derived raw material that is a non-petroleum raw material, and has a low environmental load and a very flexible sheet-like material, as well as a very flexible material. A method for producing a sheet-like material is provided.

The polyurethane composition of the present invention has the following configuration in order to achieve the above-mentioned problems.
That is, the sheet-like material of the present invention has “a non-woven fabric in which fiber bundles of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less are intertwined and polyurethane existing in the interior space as main components. A sheet-like material comprising a polymer elastic body, wherein the polyurethane contains a plant-derived structure represented by the general formula (1) in a molecular chain.

(Where n is a positive integer).

  Moreover, the manufacturing method of the sheet-like material of the present invention is expressed by the general formula (1) on a nonwoven fabric formed by entanglement of fiber bundles of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less. The method for producing a sheet-like material as described above, comprising impregnating a polymer elastic body mainly composed of a polyurethane composition containing a plant-derived skeleton in a molecular chain.

(Where n is a positive integer).

  According to the present invention, since a polyurethane using a plant-derived raw material which is a non-petroleum raw material is used, a sheet material having a low environmental load and a very soft texture, and a sheet material having a very soft texture are obtained. A manufacturing method can be provided.

  The sheet-like material of the present invention is a polymer mainly composed of a nonwoven fabric in which fiber bundles of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less are intertwined with polyurethane existing in the inner space. It consists of an elastic body.

  As the material of the ultrafine fibers constituting the nonwoven fabric, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyester such as polylactic acid, polyamide such as 6-nylon and 66-nylon, and thermoplastic resin capable of melt spinning such as acrylic Can be used. Among them, it is preferable to use polyester from the viewpoint of strength, dimensional stability, and light resistance, and it can be obtained from polytrimethylene terephthalate using 1,3-propanediol starting from a plant or a plant-derived material. Polylactic acid that can be used is more preferable from the viewpoint of reducing environmental burden. Here, as a method for obtaining polytrimethylene terephthalate and polylactic acid starting from plants, the former is produced by, for example, decomposing and saccharifying corn, converting it to glycerin by genetic modification, and fermenting it with a microorganism. It may be obtained by polymerizing 3-propanediol and terephthalic acid as a petroleum component, and the latter may be obtained by dehydration polymerization of lactic acid obtained by fermenting starch such as corn or potato with lactic acid bacteria. As a material for the ultrafine fibers constituting the nonwoven fabric, polytrimethylene terephthalate is particularly preferable because of good color developability when the obtained sheet-like material is dyed. Moreover, the nonwoven fabric may be configured by mixing ultrafine fibers of different materials.

  It is important that the average single fiber fineness of the ultrafine fibers constituting the nonwoven fabric is 0.001 dtex or more and 0.5 dtex or less from the viewpoint of sheet flexibility and napped quality. Preferably it is 0.3 dtex or less, More preferably, it is 0.2 dtex or less. On the other hand, it is preferably 0.005 dtex or more, more preferably 0.01 dtex or more from the viewpoint of dispersibility of bundled fibers during napping treatment such as coloring after dyeing or grinding with sandpaper, and ease of spreading. It is.

  In addition, the average single fiber fineness of the ultrafine fibers constituting the nonwoven fabric is a magnification of a scanning electron microscope (SEM) photograph of the surface of the sheet (or nonwoven fabric) when the cross section of the ultrafine fibers is circular or an ellipse close to a circle. It is calculated by photographing at 2000 times, selecting 100 ultrafine fibers at random, measuring the fiber diameter, converting the specific gravity of the raw material polymer into fineness, and calculating the average value of the 100 fibers. On the other hand, when the ultrafine fiber constituting the nonwoven fabric has an irregular cross section, the outer peripheral circular diameter of the irregular cross section is calculated as the fiber diameter in the same manner. Furthermore, when a circular cross section and an irregular cross section are mixed, or when those having greatly different finenesses are mixed, 100 are selected and calculated so that each has the same number.

  Regarding the uniformity of the fineness of the ultrafine fibers constituting the nonwoven fabric, the fineness CV in the fiber bundle is preferably 10% or less. Here, the fineness CV is a percentage (%) value obtained by dividing the fineness standard deviation of the fibers constituting the fiber bundle by the average fineness within the bundle, and indicates that the smaller the value, the more uniform. . By setting the fineness CV to 10% or less, the appearance of napping on the surface of the sheet-like material becomes graceful, and the dyeing can be made uniform and good. The fineness CV when the cross section of the ultrafine fiber is not a circle or an ellipse close to a circle is obtained by the same method as the calculation of the average single fiber fineness.

  The cross-sectional shape of the ultrafine fiber may be a round cross-section, but may be a polygonal shape such as an ellipse, a flat shape, or a triangle, or an irregular cross-section such as a sector shape or a cross shape.

  The nonwoven fabric constituting the sheet-like material of the present invention may be either a short fiber nonwoven fabric or a long fiber nonwoven fabric, but a short fiber nonwoven fabric is preferred when emphasis is placed on texture and quality. In addition, a woven fabric or a knitted fabric may be inserted into the nonwoven fabric for the purpose of improving the strength.

  The polyurethane used as the main component of the polymer elastic body in the sheet-like material of the present invention contains a plant-derived structure represented by the following general formula (1) in the molecular chain.

In the formula, n is a positive integer.

  By including the structure represented by the general formula (1) in the molecular chain, the crystallinity of the polyurethane is lowered, and a flexible polyurethane having a low modulus can be obtained. Moreover, the structure is obtained from plant-derived raw materials, thereby reducing the environmental load at the time of burning and discarding polyurethane itself.

  It is preferable that the polyurethane is mainly composed of a structure obtained by a reaction between a polyol having a hydroxyl group at both ends of a molecular chain having a structure represented by the general formula (1), an organic polyisocyanate, and a chain extender.

  The polyol having hydroxyl groups at both ends of the molecular chain having the structure represented by the general formula (1) is preferably a polyol made from 1,3-propanediol, which is a plant-derived material.

  The method for obtaining 1,3-propanediol is not particularly limited as long as the plant is used as a starting material. For example, sugar is converted into glycerin by genetic modification using a plant as a starting material, and is converted by a microorganism. There may be. For example, the methods described in JP-T 2006-512907, JP-T 2002-514426, JP-T 2003-507022, JP-T 2001-503636, and the like can be used.

As long as the polyol has a hydroxyl group at both ends of the molecular chain having the skeleton represented by the general formula (1), it may be any of ether-based, ester-based, and carbonate-based, but polyurethane is very flexible. Therefore, an ether polyol is preferable.
In addition, the ether type here forms a polymer chain connected through an ether bond, and the ether type polyol has one or more hydroxyl groups at both ends of the polymer chain. Is.

  The ether polyurethane in the present invention refers to a polyurethane to which an ether polyol is applied as a polyol.

  The number average molecular weight (Mn) of the polyol is preferably 500 to 3,000, more preferably 1,500 to 2,500. By setting the number average molecular weight to 500 or more, the texture is prevented from becoming hard, and by setting the number average molecular weight to 3,000 or less, the strength as polyurethane can be maintained.

  The organic polyisocyanate used for the synthesis of the polyurethane is not particularly limited. Examples include alicyclic diisocyanates such as 4,4′-dicyclohexylmethane diisocyanate and isophorone diisocyanate, and aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate. Of these, aromatic diisocyanates, particularly 4,4′-diphenylmethane diisocyanate, are preferably used from the viewpoint of durability such as strength and heat resistance of the resulting polyurethane. Moreover, you may use polyisocyanate combining these two or more.

  The ratio of polyol to organic polyisocyanate is preferably such that the molar ratio of both is 1: 2 to 1: 5. Within this range, the ratio of organic polyisocyanate should be reduced when emphasizing the flexibility of the resulting polyurethane, and the ratio of organic polyisocyanate should be increased when emphasizing strength, heat resistance, durability, etc. Can be adjusted.

The chain extender used for the synthesis of polyurethane is not particularly limited, and a compound having two or more active hydrogens can be used. Glycols such as organic diol and organic triol, amines such as organic diamine and triamine, hydrazine Derivatives and the like can be used.
Examples of glycols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, methylpentanediol, 1,6-hexanediol, 1,7- Aliphatic diols such as heptanediol, 1,8-octanediol, 1,9-nonanediol and 1,10-decanediol, alicyclic diols such as 1,4-cyclohexanediol and hydrogenated xylylene glycol, xylene glycol And aromatic diols such as

Examples of amines include ethylene diamine, isophorone diamine, xylene diamine, phenyl diamine, and 4,4′-diaminodiphenyl methane.
Examples of hydrazine derivatives include hydrazine, adipic acid dihydrazide, isophthalic acid hydrazide, and the like.

  When emphasizing the hydrolysis resistance of polyurethane, it is preferable to use a glycol type. Among them, in view of the strength, heat resistance, and yellowing resistance of polyurethane, an aliphatic diol having 2 to 6 carbon atoms in the alkyl chain, particularly ethylene. Glycol is preferred.

  Further, when importance is attached to the heat resistance of polyurethane, it is preferable to use an amine system. Among them, water is added to an aromatic diamine such as 4,4′-diaminodiphenylmethane or 4,4′-diphenylmethane diisocyanate. It is preferable to convert it to 4,4′-diaminodiphenylmethane.

  For the synthesis of polyurethane, for example, amines such as triethylamine and tetramethylbutanediamine, and metal compounds such as potassium acetate, zinc stearate, titanium tetraethylisopropoxide, and tin octylate may be used as catalysts.

As a weight average molecular weight (Mw) of a polyurethane, 100,000-300,000 are preferable, More preferably, it is 150,000-250,000. By setting the weight average molecular weight (Mw) to 100,000 or more, the film strength of the formed film is improved and the wear resistance is improved. Moreover, by setting it as 300,000 or less, the increase in the viscosity of a polyurethane solution can be suppressed and it can make it easy to impregnate a nonwoven fabric.

  The elastic polymer constituting the sheet-like material of the present invention uses polyurethane as a main component, but includes polyester resins, polyamide resins, polyolefin resins, etc., acrylic resins, silicone resins, ethylene-vinyl acetate resins, etc. Various additives such as oxazoline-based, carbodiimide-based, epoxy-based, melamine-based, isocyanate-based, silanol-based crosslinking agents, carbon black pigments, phosphorus-based, halogen-based, silicone-based, Inorganic flame retardants, phenolic, sulfur, phosphorus and other antioxidants, benzotriazoles, benzophenones, salicylates, cyanoacrylates, oxalic acid anilides and other UV absorbers, hindered amines, Light stabilizer such as benzoate, plastic , Antistatic agents, surfactants, softeners, water repellant, coagulation adjusting agent, may contain as dyes.

  In the sheet-like material of the present invention, the polymer elastic body is present in the inner space of the nonwoven fabric formed by entanglement of the fiber bundle of ultrafine fibers, but is not substantially present inside the fiber bundle of ultrafine fibers. Is preferred. If a polymer elastic body exists inside the fiber bundle, it tends to be difficult to obtain a good texture of the sheet obtained by the voids inside the fiber bundle, and it will be adhered to each ultrafine fiber, so sandpaper. When grinding by means of, for example, the fiber existing on the sheet surface is severely cut, and it is difficult to obtain the desired napped length and thereby good quality.

  In addition, it is confirmed by observing the thickness direction cross section inside the sheet-like material with a scanning electron microscope (SEM, 1000 times) that the polymer elastic body is not substantially present inside the fiber bundle of the ultrafine fibers. it can.

  Further, as a form inside the nonwoven fabric of the polymer elastic body, it is in a state where it is partially joined to the single fiber located at the outermost periphery of the fiber bundle of the ultrafine fibers, and there are few fibers falling off and peaching, and It is more preferable because a good texture can be obtained.

  The partial joining state of the polymer elastic body and the single fiber located on the outermost periphery of the fiber bundle of the ultrafine fibers is observed by a scanning electron microscope (SEM, 1000 times) in the thickness direction cross section inside the sheet. This can be confirmed.

  In the sheet-like material of the present invention, the ratio of the polymer elastic body to the sheet-like material is preferably 10% by weight or more and 50% by weight or less, more preferably 15% by weight or more and 35% by weight or less. By making it 10% by weight or more, it is possible to obtain sheet strength and prevent the fibers from falling off, and by making it 50% by weight or less, it is possible to prevent the texture from becoming hard and to achieve the desired good raised quality. Can be obtained.

  The sheet-like material of the present invention may be suitably used as a napped-toned leather-like sheet-like material having ultrafine fibers raised on at least one side, and the sheet-like material may be dyed.

  The sheet-like material of the present invention, in particular, the raised leather-like sheet-like material obtained by raising ultrafine fibers on at least one surface of the sheet is a furniture, a chair, a wall material, a seat in a vehicle room such as an automobile, a train, an aircraft, Interior materials that have a very elegant appearance as a skin material for ceilings, interiors, shirts, jackets, casual shoes, sports shoes, men's shoes, women's shoes, uppers, trims, bags, belts, wallets, etc. It can be suitably used as industrial materials such as clothing materials, wiping cloths, polishing cloths, CD curtains, etc. used for some of them.

  Next, the manufacturing method of the sheet-like material of the present invention will be described.

  The method for producing a sheet-like product of the present invention is derived from a plant represented by the general formula (1) on a nonwoven fabric in which fiber bundles of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less are entangled. It is impregnated with a polymer elastic body mainly composed of a polyurethane composition containing a skeleton in the molecular chain.

(In the formula, n is a positive integer.)
As a means for obtaining ultrafine fibers, it is preferable to use ultrafine fiber generating fibers. By performing the ultrafine fiber after entanglement of the ultrafine fiber generating fiber in advance, a nonwoven fabric in which the ultrafine fibers are entangled in a bundle can be obtained. The strength of the sheet can be obtained because the ultrafine fibers are entangled in a bundle.

  As ultra-fine fiber generation type fibers, two-component thermoplastic resins with different solvent solubility are used as sea components and island components, and the sea components are dissolved and removed using a solvent, etc., so that the island components are made into ultra-fine fibers. It is possible to employ a peelable composite fiber that splits fibers into ultrafine fibers by alternately arranging fibers or two-component thermoplastic resin radially or in a multilayer shape on the fiber cross section, and separating and separating each component. Among them, the sea-island type composite fiber can provide an appropriate gap between the island components, that is, between the ultrafine fibers inside the fiber bundle by removing the sea component, so from the viewpoint of sheet flexibility and texture. Is also preferable.

  For the sea-island type composite fiber, a polymer inter-array system that uses the sea-island type composite base to spin the two components of the sea and the islands, and the mixed spinning method that mixes and spins the two components of the sea and the islands. However, a sea-island type composite fiber based on a polymer mutual array system is more preferable in that an ultrafine fiber having a uniform fineness can be obtained.

As the sea component of the sea-island type composite fiber, polyethylene, polypropylene, polystyrene or the like can be used.
As the solvent for dissolving the sea component, an organic solvent such as toluene or trichlorethylene can be used, and it can be removed by immersing the sea-island type composite fiber in the solvent and performing a stenosis solution.

The ultrafine fiber-generating fiber is crimped and cut into a predetermined length to obtain a non-woven raw cotton. A usual method can be used for crimping and cutting.
The obtained raw cotton is made into a web with a cross wrapper or the like, and then the fibers are entangled to make a nonwoven fabric.

  As a method for obtaining a nonwoven fabric by entanglement of fibers, usual methods such as needle punching and water jet punching can be used.

  The obtained non-woven fabric may be subjected to a shrinking treatment by hot water or steam treatment or a compression treatment such as hot pressing in order to improve the fineness of the fibers.

A method for applying the organic solvent solution of polyurethane (hereinafter referred to as a polyurethane solution) to the nonwoven fabric is not particularly limited, but in the sheet-like material of the present invention, the polymer elastic body containing polyurethane as a main component is the interior of the nonwoven fabric. Since it is preferable to obtain a form that exists in the space but does not substantially exist inside the fiber bundle of ultrafine fibers, the polyurethane is made into a solution with an organic solvent such as dimethylformamide, dimethylacetamide, tetrahydrofuran, dioxane,
(A) After impregnating the above-mentioned polyurethane solution into a nonwoven fabric intertwined with ultra-fine fiber-generating sea-island composite fibers and coagulating in water or an organic solvent aqueous solution, the sea component of the sea-island composite fibers is Method of dissolving and removing with an organic solvent that does not dissolve (B) Polyvinyl alcohol having a saponification degree of preferably 80% or more is applied to a nonwoven fabric intertwined with ultra-fine fiber-generating sea-island composite fibers to protect most of the periphery of the fibers After that, the sea component of the sea-island type composite fiber is dissolved and removed with a solvent in which polyvinyl alcohol does not dissolve, then impregnated with the above-mentioned polyurethane solution and solidified in water or an organic solvent aqueous solution, and then the polyvinyl alcohol is removed. Etc. can be preferably used.

  Incidentally, as a means for obtaining a form in which the polymer elastic body mainly composed of polyurethane is present in the inner space of the nonwoven fabric, a production method in which a large amount of polyurethane is present inside the fiber bundle of ultrafine fibers, for example, polyurethane as a sea component. As a dispersion medium component, using polyurethane-based multicomponent fibers in which a polymer that is incompatible with the polyurethane is used as a dispersion component, the polyurethane as the dispersion medium component is once dissolved in a solvent, and a polymer ultrafine fiber as a dispersion component is obtained. A method of solidifying and fixing the polyurethane without removing it after it has been expressed, or removing the sea component first without giving polyvinyl alcohol etc. to the fiber having a sea-island structure, and then impregnating with polyurethane However, in these methods, an elastic resin binder is substantially present inside the fiber bundle of ultrafine fibers. Form, such as not not be achieved.

  Moreover, in the sheet-like product of the present invention, as a form inside the nonwoven fabric of the polymer elastic body, it is in a state of being partially joined to the single fiber located on the outermost periphery of the fiber bundle of ultrafine fibers, It is more preferable because there are few fibers falling off and peaching and a good texture can be obtained, and the form can be obtained by the method (B). That is, since the polyvinyl alcohol protects most of the outer periphery of the microfiber bundle, the polyurethane is prevented from entering the fiber bundle, and the polyurethane adheres to the outer periphery of the fiber bundle that is not partially protected by polyvinyl alcohol. It will be.

  In the method for producing a sheet-like product of the present invention, raising treatment may be performed to form napped on the sheet surface. The raising treatment can be performed by a method of grinding using sandpaper, roll sander or the like. A lubricant such as a silicone emulsion may be applied before the raising treatment.

  In addition, it is preferable to apply an antistatic agent before the raising process, because the grinding powder generated from the sheet-like material by grinding tends to be difficult to deposit on the sandpaper.

  Further, the sheet-like material may be obtained by being divided into half or several sheets in the sheet thickness direction before the raising treatment.

  The manufacturing method of the sheet-like material of the present invention may dye the sheet-like material. As the dyeing method, it is preferable to use a liquid dyeing machine because the sheet-like material can be further softened by dyeing the sheet-like material and simultaneously giving a stagnation effect. As the liquid dyeing machine, a normal liquid dyeing machine can be used.

  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. Therefore, it may be changed depending on the type of the fiber, and generally 80 ° C. or higher and 150 ° C. or lower is preferable. 110 ° C. or higher and 130 ° C. or lower is more preferable.

The dye is not particularly limited and may be selected according to the ultrafine fiber constituting the sheet-like material. For example, a polyester-based ultrafine fiber is a disperse dye, and a polyamide-based ultrafine fiber is a dye such as an acid dye or a metal-containing dye, And dyes combining them can be used.
When dyed with disperse dyes, reduction washing may be performed after dyeing.

  Moreover, it is preferable to use a dyeing assistant during dyeing for the purpose of improving the uniformity and reproducibility of dyeing. Furthermore, finishing agents such as softeners such as silicone, antistatic agents, water repellents, flame retardants, light proofing agents, deodorants, and anti-pilling agents may be applied. But you can.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely using an Example, this invention is not limited only to a following example.

[Evaluation methods]
(1) Average single fiber fineness A scanning electron microscope (SEM) photograph of the surface of a non-woven fabric or sheet-like material was taken at a magnification of 2000 times, and 100 fibers having a circular shape or a nearly elliptic shape were randomly selected, and the fiber diameter was selected. It was calculated by measuring and calculating the average value.

(2) Fineness CV
A cross section in the thickness direction inside the nonwoven fabric or sheet is observed with a scanning electron microscope (SEM, 2000 times), and the fiber diameter of the ultrafine fibers constituting one bundle of bundle fibers is measured from the photograph. Then, the fiber diameter was converted into the fineness of each single fiber, and the value obtained by dividing the fineness standard deviation of the fibers constituting the fiber bundle by the average fineness in the bundle was expressed as a percentage (%). The same measurement was performed on the five bundle fibers, and the average value was defined as the fineness CV.

(3) Sheet-like structure The cross-section in the thickness direction inside the sheet-like article is observed with a scanning electron microscope (SEM, 1000 times), and the positional relationship between the ultrafine fiber bundle and polyurethane (the polyurethane is inside or outside the ultrafine fiber bundle) And the presence / absence of bonding with the single fiber located on the outermost periphery of the ultrafine fiber bundle).

(4) Flexibility Based on method A (45 ° cantilever method) described in JIS L1096-8.19.1 (2005 edition), 5 test pieces each having a size of 2 × 15 cm are prepared in the vertical and horizontal directions. The sample was placed on a horizontal base having a slope of ° C, and the test piece was slid to read the scale when the center point of one end of the test piece was in contact with the slope, and the average value of the five pieces was determined.

[Notation of chemical substances]
The meanings of the abbreviations of chemical substances used in each example and comparative example are as follows.
PTT: Polytrimethylene terephthalate PET: Polyethylene terephthalate MDI: 4,4′-diphenylmethane diisocyanate
EG: Ethylene glycol
DMF: N, N-dimethylformamide
PPG: Polypropylene glycol PHC having a number average molecular weight of 2,000 derived from plant-derived 1,3-propanediol: Polycarbonate diol having a number average molecular weight of 2,000 derived from 1,6-hexanediol.

[Polyurethane synthesis example 1]
PPG as a polyol, MDI as an organic diisocyanate, and DPG as a solvent so that the molar ratio of PPG: MDI is 1: 3 is charged into a four-neck separable colben with a cooling tube and stirred at 40 to 60 ° C. in a nitrogen atmosphere. Further, EG as a chain extender was reacted dropwise at 50-60 ° C. in a state diluted with DMF, and then gradually diluted with DMF. After about 10 hours, a polyurethane solution A having a solid content of 12% was added. Obtained.

[Polyurethane synthesis example 2]
A polyurethane solution B having a solid content of 12% was obtained in the same manner as in Polyurethane Synthesis Example 1 except that PHC was used as the polyol.

[Example 1]
Copolymer polystyrene is used as the sea component, polytrimethylene terephthalate (PTT) using 1,3-propanediol starting from a plant as the island component, and a sea-island type compound base with 16 islands is used. A sea-island composite fiber was spun at a composite ratio of 55% by weight of the component and 45% by weight of the island component, and then stretched, crimped, and cut to obtain a raw nonwoven fabric.

  The obtained raw cotton was made into a web using a cross wrapper and made into a nonwoven fabric by needle punching.

  The nonwoven fabric composed of this sea-island type composite fiber was impregnated with a 10% aqueous solution of polyvinyl alcohol having a saponification degree of 87% and then dried. Thereafter, polystyrene, which is a sea component, was extracted and removed from trichlorethylene and dried to obtain a nonwoven fabric in which fiber bundles made of ultrafine fibers having an average single fiber fineness of 0.1 dtex were intertwined. The fineness CV was 7.3%.

  This nonwoven fabric was dipped in the polyurethane solution A, the amount of the polyurethane solution adhered was adjusted with a squeeze roll, and then the polyurethane was coagulated in an aqueous solution having a DMF concentration of 30% at 30 ° C. Thereafter, polyvinyl alcohol and DMF are removed with hot water at 90 ° C., dried, then impregnated with an aqueous silicone emulsion solution, dried, and then a sheet-like material having a polyurethane content of 32% by weight and a silicone content of 0.2% by weight. Got.

  One side of the obtained sheet-like material was brushed by grinding using 150 mesh and then 240 mesh endless sandpaper, and dyed with disperse dye to obtain a sheet-like material.

  When the cross section in the thickness direction inside the obtained sheet-like material was observed with a scanning electron microscope (SEM), the polymer elastic body was not substantially present inside the ultrafine fiber bundle, and the ultrafine fiber bundle was not present. It was confirmed that the fiber was partially joined to the single fiber located on the outermost periphery of the wire.

  The obtained sheet-like material had a very soft texture and a little environmental load.

[Example 2]
A sheet-like material was obtained in the same manner as in Example 1 except that polystyrene was used as the sea component and polyethylene terephthalate (PET) was used as the island component.

  When the cross section in the thickness direction inside the obtained sheet-like material was observed with a scanning electron microscope (SEM), the polymer elastic body was not substantially present inside the ultrafine fiber bundle, and the ultrafine fiber bundle was not present. It was confirmed that the fiber was partially joined to the single fiber located on the outermost periphery of the wire.

  The obtained sheet-like material had a very soft texture and a little environmental load.

[Comparative Example 1]
A sheet-like material was obtained in the same manner as in Example 1 except that the polyurethane solution B was applied instead of the polyurethane solution A.

  When the cross section in the thickness direction inside the obtained sheet-like material was observed with a scanning electron microscope (SEM), the polymer elastic body was not substantially present inside the ultrafine fiber bundle, and the ultrafine fiber bundle was not present. It was confirmed that the fiber was partially joined to the single fiber located on the outermost periphery of the wire.

  The obtained sheet-like material had a hard texture and a large environmental load.

Claims (10)

A sheet composed of a nonwoven fabric in which fiber bundles of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less are intertwined, and a polymer elastic body mainly composed of polyurethane existing in the internal space A sheet-like product, wherein the polyurethane contains a plant-derived structure represented by the general formula (1) in a molecular chain.

(In the formula, n is a positive integer.)   The sheet-like article according to claim 1, wherein the polyurethane is an ether-based polyurethane.   The sheet-like material according to claim 1, wherein the ultrafine fiber is polyester.   The sheet-like product according to any one of claims 1 to 3, wherein the ultrafine fiber is a polyester mainly composed of polytrimethylene terephthalate.   The sheet-like material according to any one of claims 1 to 4, wherein the polymer elastic body does not substantially exist inside a fiber bundle of ultrafine fibers.   The sheet-like material according to any one of claims 1 to 5, wherein the polymer elastic body is partially bonded to a single fiber located on the outermost periphery of the fiber bundle.   The ratio of the elastic resin binder which occupies for a sheet-like material is 10 to 50 weight%, The sheet-like material in any one of Claims 1-6 characterized by the above-mentioned.   The sheet-like material according to any one of claims 1 to 7, wherein the sheet-like material has napped fibers of at least one surface. A polyurethane composition comprising, in a molecular chain, a plant-derived skeleton represented by the general formula (1) in a non-woven fabric formed by entanglement of fiber bundles of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less A method for producing a sheet-like material, comprising impregnating a polymer elastic body as a main component.

(In the formula, n is a positive integer.)   The method for producing a sheet-like material according to claim 9, wherein the non-woven fabric is an ultrafine fiber-generating fiber.