JP2006307000A - Polyurethane composition, sheet-like product using the same and interior material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane composition flexible and good in durability, a sheet-like product that combines high durability and elegant appearance and feeling by using it, and an interior material using the sheet-like product as a skin material. <P>SOLUTION: The sheet-like product consists of a polyurethane composition containing in the molecular chain a carbonate structure represented by general formula (1) and a nonwoven fabric of ultrafine fibers using it as an elastic resin binder. This sheet-like product is suitably used for the interior material as the skin material of furniture, a chair, a wall decoration, a vehicle seat, a vehicle ceiling, a vehicle trim and the like. In general formula (1), R<SB>1</SB>is a 1-4C aliphatic hydrocarbon group, R<SB>2</SB>is a 1-3C aliphatic hydrocarbon group, the number of the total carbons of R<SB>1</SB>and R<SB>2</SB>is ≥4 and ≤7, and x is an integer of 2-20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyurethane composition, a sheet-like material using the same, and an interior material. Specifically, it is suitable as a polyurethane composition from which a flexible film can be obtained and a sheet material of an ultra-fine fiber nonwoven fabric using the same, and as a skin material for furniture, chairs, wall coverings, vehicle seats, vehicle ceilings, vehicle interiors, etc. It relates to the interior material used.

  It is widely used to obtain suede or nubuck-like napped leather-like sheet-like materials by grinding the surface of a sheet-like material impregnated with polyurethane resin on a fiber substrate using sandpaper and raising the fibers. Are known. The characteristics of the target leather-like sheet can be arbitrarily designed in a wide range by combining the substrate made of fibers and the polyurethane resin. For example, Patent Document 1 discloses a polyurethane resin using polytetramethylene glycol, organic diisocyanate, and a glycol chain extender. By using the polyurethane resin, it is compared with a high-grade wool fabric used for a suit or the like. However, it is described that it has become possible to obtain an artificial leather-like material having a very soft texture that is not inferior.

  Napped-toned leather-like sheets have an appearance and surface very similar to natural leather, and have advantages such as uniformity and dyeing fastness that are not found in natural leather. Not only clothing, but also furniture such as sofas in recent years. It is spreading to applications that are used for a long period of 5 to 10 years, such as skins and car seats.

  For this reason, in the polyether-based polyurethane resin using polytetramethylene glycol as described in Patent Document 1, it is easily deteriorated by ultraviolet rays or heat. There was a problem that it could not withstand long-term use. Polyester-based polyurethane resin is also a polyurethane resin often used for leather-like sheets, but although it has good light resistance due to ultraviolet rays etc., the ester bond deteriorates due to hydrolysis. There were similar problems such as the occurrence of peaches and hairballs.

  On the other hand, in Patent Document 2, a polycarbonate-based polyurethane resin obtained by reacting a polycarbonate polyol, an alicyclic polyisocyanate and an aromatic polyisocyanate is useful for applications having high durability such as furniture and vehicle seats. It is disclosed that it is a polyurethane resin. The patent document discloses a polyurethane using polyhexamethylene carbonate as a polycarbonate-based polyurethane resin. However, when the polyurethane is used as an impregnation resin on a nonwoven fabric in which ultrafine fibers are entangled, a sheet form is used. The texture of the object is plastic and rough. In particular, when the surface is raised with sandpaper or the like, the polyurethane is too hard, resulting in a rough surface with short napping on the surface, and it is extremely difficult to obtain good quality with elegant napping. there were.

  For the purpose of achieving both napped quality and durability such as light resistance and hydrolysis resistance, Patent Document 3 discloses a polyether diol or polyester having 30 to 90% by weight of polycarbonate diol, mainly polyhexamethylene carbonate diol. Napped leather-like sheet-like materials using a polycarbonate / polyether polyurethane resin or a polycarbonate / polyester polyurethane resin combined with a diol are disclosed. However, when the ratio of the polycarbonate diol is 70% by weight or less, durability is insufficient due to deterioration of the polyether component or the polyester component, while when the ratio of the polycarbonate diol is 70% by weight or more, Polyurethane became too hard, and when the surface was ground with sandpaper or the like, the surface napping was short and rough, and it was difficult to obtain napped leather-like sheet-like material satisfying both napping quality and durability. .

  In addition, in a leather-like sheet in which a resin layer is applied or laminated on a fibrous base material, so-called synthetic leather, it is known to use a polycarbonate-based polyurethane resin for the resin layer for the purpose of improving durability. Various proposals have been made for polycarbonate-based polyurethane resins used in this resin layer mainly for the purpose of improving the texture of synthetic leather.

  For example, Patent Document 4 discloses a polyurethane resin using a copolymerized polycarbonate diol derived from 1,6-hexanediol and 1,5-pentanediol, and 1,6-hexanediol and 1,4-butanediol. Polyurethane resin using copolymer polycarbonate diol derived, Patent Document 5 includes polyurethane resin using polycarbonate diol derived from 2-methyl-1,8-octanediol, Patent Document 6 includes 5 carbon atoms Polyester / polycarbonate polyurethane resin using a polyester diol derived from an alkanediol having 6 to 6 carbon atoms and a polycarbonate diol derived from an alkanediol having 8 to 10 carbon atoms. Derived from alkanediols Polycarbonate / polyether-based polyurethane resin in combination with polycarbonate diols and polyether diols is disclosed.

  As a resin impregnated into these nonwoven fabrics in which ultrafine fibers are entangled with each other, sheet-like materials existing in the interior space of the nonwoven fabrics, in particular, the napped texture in which the surface fibers are raised by grinding the surface with sandpaper etc. When applied to a leather-like sheet, for example, in the copolymerized polycarbonate polyurethane having 4 to 6 carbon atoms described in Patent Document 4, a softening effect that can be ground by sandpaper cannot be obtained. In addition, since the surface napping becomes a short and rough surface, it is extremely difficult to obtain a good quality having elegant napping. In addition, since the polycarbonate-based polyurethane resin derived from 2-methyl-1,8-octanediol described in Patent Document 5 uses a long-chain alkylene diol, it is impregnated into a nonwoven fabric and then wet coagulated. Is extremely fast, and foaming of polyurethane inside the nonwoven fabric becomes large and rough, and as a result of partial foaming failure, there is unevenness in the length of surface napping when grinding with sandpaper. There was a problem that only a poor one could be obtained. Further, when the surface of the obtained sheet-like material is rubbed with a brush or the like, there is a problem in abrasion resistance because many fibers fall off. The polyurethane resins described in Patent Documents 6 and 7 are durable in the long-term use of napped leather-like sheet-like materials from the viewpoint of hydrolysis resistance or light resistance in that polyester diol and polyether diol are used in combination. It does not lead to improvement of the property, particularly the problem of surface fiber peaches and pills.

As described above, according to the conventional technique, it is extremely difficult to obtain a nap-finished leather-like sheet-like material that is excellent in texture, napping quality, and durability.
Japanese Patent Laid-Open No. 59-19279 JP-A-3-244619 JP 2002-30579 A JP-A-5-5280 JP-A-2-33384 Japanese Patent Laid-Open No. 4-300368 JP-A-5-9875

  The present invention has been made in view of the background of the prior art, and an object of the present invention is to provide a flexible and durable polyurethane composition, and by using the polyurethane composition, fibers may fall off, peach, hair, even in long-term use. Providing napped leather-like sheet-like material that has high durability with less occurrence of balls, elegant appearance by napping, texture like natural leather, and interior materials that use that sheet-like material as the skin material It is.

  The polyurethane composition of the present invention has the following configuration in order to solve the above problems.

  That is, it is a polyurethane composition characterized by including a carbonate structure represented by the general formula (1) in a molecular chain.

(In the formula, R ₁ is an aliphatic hydrocarbon group having 1 to 4 carbon atoms, R ₂ is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and the total number of carbon atoms of R ₁ and R ₂ is 4 or more and 7 or less. Moreover, x is a positive integer of 2 to 20.)
The sheet-like material of the present invention is an elastic material 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 internal space. A sheet-like material composed of a resin binder, wherein the polyurethane is the polyurethane composition.

  Furthermore, the interior material of the present invention is characterized in that the sheet-like material is a skin material.

  According to the present invention, it is possible to provide a polyurethane composition that is flexible and has excellent durability such as hydrolysis resistance and light resistance.

  In addition, according to the sheet-like material of the present invention, even when used for a long period of time, it has a high durability with less fiber dropping, peaching, and pilling, an elegant appearance due to napping, and a raised texture that has a texture like natural leather. A leather-like sheet can be provided.

  Furthermore, according to the interior material of the present invention, an interior material having an elegant appearance can be provided.

  The polyurethane composition of the present invention contains a carbonate structure represented by the following general formula (1) in the molecular chain.

However, in the formula, R ₁ is an aliphatic hydrocarbon group having 1 to 4 carbon atoms, R ₂ is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and the total number of carbon atoms of R ₁ and R ₂ is 4 or more and 7 It is as follows. Moreover, x is a positive integer of 2-20.

By having a branched structure of an aliphatic hydrocarbon group such as R ₁ and R ₂ , polyurethane easily becomes an amorphous structure, and a flexible film can be obtained.

When R ₁ and R ₂ having a branched structure have a large number of carbon atoms, a flexible film can be obtained, but the film strength is lowered and the wear resistance is deteriorated. Accordingly, the carbon number of R ₁ is preferably 2 or 3, the carbon number of R ₂ is 2 to 3, and the total number of carbon atoms of R ₁ and R ₂ is 4 or more and 6 or less, particularly preferably the following general formula (3 ), R ₁ has 3 carbon atoms, and R ₂ has 2 carbon atoms.

  However, in the formula, x is a positive integer of 2-20.

  Moreover, it is preferable that the polyurethane composition of this invention contains the carbonate structure shown by following General formula (2) in a molecular chain.

However, in the formula, y and z are 0 or a positive integer and satisfy 3 ≦ y + z ≦ 30. R ₃ and R ₄ are aliphatic hydrocarbon groups having 3 to 6 carbon atoms, which may be the same or different, but are different from each other in that the polyurethane has a more amorphous structure. The resulting film tends to be flexible.

From the viewpoint of obtaining further flexibility, it is preferable that at least one of R ₃ and R ₄ is an aliphatic hydrocarbon group in which a methyl group or an ethyl group is branched.

  The carbonate skeleton represented by the general formulas (1) and (2) may be either block copolymerization or random copolymerization, but is preferably random copolymer in which the polyurethane tends to have an amorphous structure.

  More specifically, the polyurethane composition includes a polycarbonate diol (A) having a hydroxyl group at both ends of a molecular chain having a carbonate skeleton represented by the general formula (1), and a carbonate skeleton represented by the general formula (2). It is preferable that it has a structure obtained by reaction of polycarbonate diol (B) having a hydroxyl group at both ends of a molecular chain having an organic diisocyanate and a chain extender.

  The carbonate skeleton as used in the present invention forms a polymer chain linked through a carbonate bond, and the polycarbonate diol has one hydroxyl group at both ends of the polymer chain. .

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

Examples of the alkylene glycol for obtaining the polycarbonate diol (A) having a carbonate skeleton represented by the general formula (1) include 2-ethyl-1,3-pentanediol, 2-propyl-1,3-pentanediol, 2-propyl- 1,3-hexanediol, 2-ethyl-1,3-hexanediol and the like can be used. In view of flexibility and wear resistance of the film formed, 2-ethyl-1,3-hexanediol is preferably used.
The alkylene glycol for obtaining the polycarbonate diol (B) having a carbonate skeleton having a long-chain aliphatic hydrocarbon group having 3 to 6 carbon atoms represented by the general formula (2) includes propylene glycol and 1,4-butanediol. , Linear alkylene glycols such as 1,5-pentanediol and 1,6-hexanediol, and branched alkylene glycols such as neopentyl glycol and 3-methyl-1,5-pentanediol can be used. In view of flexibility and wear resistance of the film formed, it is particularly preferable to use linear alkylene glycol and branched alkylene glycol obtained from 1,6-hexanediol and 3-methyl-1,5-pentanediol. It is a copolymerized polycarbonate diol obtained.

  Examples of the carbonic acid ester used for the transesterification include diethyl carbonate and diphenyl carbonate.

  The number average molecular weight (Mn) of the polycarbonate diols (A) and (B) 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.

  In view of durability such as hydrolysis resistance and light resistance, polymer diols used for the synthesis of polyurethane are polymer diols other than polycarbonate diol, such as polyester diol, polylactone diol, castor oil-based polyol, polyether diol, polyester diol, It is preferable not to use ether diol.

  The organic diisocyanate used for the synthesis of the polyurethane is not particularly limited. , 4'-dicyclohexylmethane diisocyanate, alicyclic diisocyanate such as isophorone diisocyanate, and aliphatic diisocyanate 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.

  A plurality of diisocyanates may be used in combination.

  The ratio between the polycarbonate diol (A) and the organic diisocyanate, or when the polycarbonates (A) and (B) are used in combination, the ratio between the total of the polycarbonates (A) and (B) and the organic diisocyanate is the molar ratio of both. The ratio is preferably 1: 2 to 1: 5. Also, within this range, adjust the ratio of organic diisocyanate by lowering the ratio of organic diisocyanate when emphasizing the flexibility of the resulting polyurethane, and increasing the ratio of organic diisocyanate when emphasizing strength, heat resistance, and durability. Is possible.

  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, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, methylpentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 , 8-octanediol, 1,9-nonanediol, aliphatic diols such as 1,10-decanediol, alicyclic diols such as 1,4-cyclohexanediol and hydrogenated xylylene glycol, and aromatics such as xylene glycol Diols can be mentioned.

  Examples of amines include ethylene diamine, isophorone diamine, xylene diamine, phenyl diamine, 4,4'-diaminodiphenyl methane, and the like.

  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 polyurethane composition of the present invention preferably has a gel point of 2.5 ml or more and less than 6 ml. More preferably, it is the range of 3 ml or more and 5 ml or less.

  The gelation point as used in the present invention means that 100 g of an N, N′-dimethylformamide (hereinafter abbreviated as DMF) solution of 1% by weight of polyurethane is stirred and distilled water is dropped into this solution at 25 ± 1 ° C. This is the value of the amount of water dripping when the polyurethane begins to coagulate under the temperature condition and becomes slightly cloudy. For this reason, it is necessary to use the DMF used for the measurement having a water content of 0.03% or less. This measurement method is described on the assumption that the polyurethane DMF solution is transparent. However, when the polyurethane DMF solution is slightly cloudy in advance, the solidification of the polyurethane starts and the degree of cloudiness changes. The amount of water dropped can be regarded as the gel point.

  The gel point indicates the moisture tolerance when polyurethane is wet-coagulated using a polyurethane DMF solution. Generally, those having a low gel point have a fast solidification rate and those having a high gel point. The coagulation rate tends to be slow. For this reason, when the gel point is less than 2.5 ml, when the polyurethane resin is wet-coagulated, the coagulation rate is too high. As a result, when the nonwoven fabric is impregnated, polyurethane foam becomes large and rough. Partial foaming failure occurs. And when the surface of a sheet-like material is ground with sandpaper, the surface of the surface is raised and the length of the raised surface tends to be very poor, and the polyurethane film becomes thin. The effect as a binder for fixing the fibers is small, and when the surface napping is rubbed with a brush or the like, the fibers tend to fall off.

  On the other hand, when the gel point is 6 ml or more, when the polyurethane resin is wet coagulated, the coagulation rate is too slow. It exists as a thick, hard polyurethane. For this reason, when the surface of a sheet-like material is ground with sandpaper, it is difficult to grind polyurethane, and the napping on the surface tends to be inferior with a very short quality.

  In order to obtain a gel point of 2.5 ml or more and less than 6 ml of the present invention, a molecule having a carbonate skeleton represented by the general formula (1) depends on the type and amount of organic diisocyanate and chain extender used for the synthesis of polyurethane. It is possible to adjust the weight ratio between the polycarbonate diol (A) having hydroxyl groups at both ends of the chain and the polycarbonate diol (B) having hydroxyl groups at both ends of the molecular chain having the carbonate skeleton represented by the general formula (2). is there.

  In order to keep the gel point low in the target gelation range, the ratio of the polycarbonate diol (A) is increased. Conversely, to increase the gel point, the ratio of the polycarbonate diol (A) is decreased. Can be adjusted.

  In addition, the elastic resin binder uses polyurethane as a main component, but the polyester resin, polyamide resin, polyolefin resin, etc., acrylic resin, silicone resin, ethylene-vinyl acetate resin as long as the performance and texture as a binder are not impaired. Various additives such as pigments such as carbon black, phosphorus-based, halogen-based, silicone-based, inorganic-based flame retardants, phenol-based, sulfur-based, phosphorus-based antioxidants, etc. UV absorbers such as benzotriazoles, benzophenones, salicylates, cyanoacrylates, oxalic acid anilides, light stabilizers such as hindered amines and benzoates, hydrolysis stabilizers such as polycarbodiimides, plasticizers , Antistatic agent, surfactant, soft Agents, water repellent agents, coagulation modifiers, may contain as dyes.

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

  The sheet-like material of the present invention is an elastic resin binder 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.

  As the material of the ultrafine fibers constituting the nonwoven fabric, a thermoplastic resin that can be melt-spun such as polyester such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyamide such as 6-nylon and 66-nylon, and acrylic is used. Can do. Among these, it is preferable to use polyester from the viewpoints of strength, dimensional stability, and light resistance.

  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, from the viewpoint of dispersibility of bundled fibers at the time of raising treatment such as coloring after dyeing or grinding with sandpaper or the like, it is preferably 0.005 dtex or more, more preferably 0.01 dtex or more. It is.

  The average single fiber fineness was measured by taking a scanning electron microscope (SEM) photograph of the surface of the sheet-like material at a magnification of 2000 times, randomly selecting 100 circular or nearly elliptical fibers, and measuring the fiber diameter. The average value is calculated.

  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 disposing fibers or two-component thermoplastic resin in a radial or multilayered cross section 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.

  In particular, regarding the uniformity of the fineness, 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 can be elegant, and the dyeing can be uniform and good.

  As the sea component of the sea-island composite fiber, polyethylene, polypropylene, polystyrene, copolymerized polyester obtained by copolymerizing sodium sulfoisophthalic acid, polyethylene glycol, or the like, polylactic acid, or the like can be used.

  As the solvent for dissolving the sea component, an organic solvent such as toluene or trichloroethylene in the case of polyethylene, polypropylene, or polystyrene, and an alkaline aqueous solution such as sodium hydroxide can be used in the case of the copolymerized polyester or polylactic acid. It can be removed by immersing the sea-island composite fiber in it and applying a stenosis solution.

  In addition, 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.

  As a method of entangled fibers to obtain a nonwoven fabric, a method of entanglement with a needle punch or a water jet punch can be employed.

  As the polyurethane used as the main component of the elastic resin binder in the sheet-like material of the present invention, it is important to use the above-described polyurethane of the present invention.

  In the sheet-like material of the present invention, the elastic resin binder is present in the inner space of the nonwoven fabric formed by entanglement of the fiber bundles of ultrafine fibers, but may not be substantially present inside the fiber bundles of ultrafine fibers. preferable. If the elastic resin binder is present even 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 etc. When grinding by, the fiber existing on the surface of the sheet is severely cut and it is difficult to obtain the desired napped length and thereby good quality.

As a method for obtaining a form in which an elastic resin binder mainly composed of polyurethane is present in the inner space of the nonwoven fabric but is not substantially present in the fiber bundle of the ultrafine fibers, polyurethane can be obtained by using dimethylformamide, dimethylacetamide, tetrahydrofuran, dioxane. Make a solution with a solvent such as
(A) After impregnating the above-described polyurethane solution of the present invention into a nonwoven fabric entangled with the ultra-fine fiber generating type sea-island composite fiber, and coagulating it in water or an organic solvent aqueous solution, the sea-island composite A method of dissolving and removing the sea component of the fiber with a solvent that does not dissolve polyurethane (B) Polyvinyl alcohol having a saponification degree of preferably 80% or more to the nonwoven fabric intertwined with the ultra-fine fiber-generating sea-island composite fiber as described above After protecting most of the periphery of the fiber, the sea component of the sea-island composite fiber is dissolved and removed with a solvent that does not dissolve polyvinyl alcohol, and then impregnated with the above-described polyurethane solution of the present invention, and water or organic A method of removing polyvinyl alcohol after coagulation in a solvent aqueous solution can be preferably used.

  As a means of obtaining a form in which the elastic resin binder mainly composed of polyurethane is present in the inner space of the nonwoven fabric, a manufacturing method in which a large amount of polyurethane exists in the fiber bundle of ultrafine fibers, for example, polyurethane is dispersed as a sea component. Using a polyurethane-based multicomponent fiber in which a polymer that is incompatible with the polyurethane is used as a dispersion component, once the polyurethane as the dispersion medium component is dissolved in a solvent, a polymer ultrafine fiber as a dispersion component is expressed. After making it solidify and fix without removing the polyurethane, after removing the sea component without giving polyvinyl alcohol etc. to the fiber having a sea-island structure to express the ultrafine fiber, impregnated with polyurethane, There are methods to solidify, but in these methods, an elastic resin binder is substantially contained inside the fiber bundle of ultrafine fibers. Form such does not exist can not be achieved.

  Moreover, as a form inside the nonwoven fabric of the elastic resin binder, it is in a state in which it is partially bonded to the single fiber located on the outermost periphery of the fiber bundle of the ultrafine fiber, and the fiber is less dropped and peach is good. It is more preferable because a fresh texture can be obtained. This form can be obtained by the above 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 sheet material of the present invention, the ratio of the elastic resin binder to the sheet material is preferably 10% by weight or more and 50% by weight or less, and 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 can be suitably used as a napped leather-like sheet-like material having napped fibers of ultrafine fibers on at least one surface.

  The raising treatment for forming napping on the surface of the sheet can be performed by a method of grinding using a sandpaper or a roll sander. 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.

 These sheet-like materials, particularly napped leather-like sheet-like materials obtained by raising ultrafine fibers on at least one side of the sheet, are furniture, chairs, wall coverings, seats, ceilings in automobile interiors such as automobiles, trains, aircraft, It can be suitably used as an interior material having a very elegant appearance as a skin material such as an interior.

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) While stirring 100 g of N, N′-dimethylformamide (DMF) solution of 1% by weight of gel point polyurethane, distilled water was dropped into this solution, and the polyurethane coagulated under the temperature condition of 25 ± 1 ° C. The value of the amount of water dripping when it started to become slightly cloudy was taken as the gel point. The DMF used for the measurement has a water content of 0.03% or less.

This measurement method is based on the premise that the polyurethane DMF solution is transparent. However, when the polyurethane DMF solution is slightly cloudy in advance, the dripping of water when the solidification of the polyurethane starts and the degree of cloudiness changes. The amount was taken as the gel point.
(2) Flexibility of polyurethane film The sensory evaluation was performed as follows. In addition, the softness | flexibility level of the film | membrane of the polyurethane composition of this invention is more than (circle).

  A: Very flexible.

  ○: Flexible.

X: Hard.
(3) Abrasion resistance of polyurethane film The film surface was rubbed 10 times with a finger, and the friction part was visually confirmed and evaluated as follows. In addition, the abrasion resistance level of the film | membrane of the polyurethane composition of this invention is (circle) or more.

  A: No abrasion was observed at all.

  ○: Although the worn part can be confirmed, it was hardly worn.

X: Worn.
(4) Appearance quality The surface quality of the obtained napped leather-like sheet was evaluated by visual sensory evaluation as follows.

  A: Napped length and fiber dispersion state are very good.

  ○: Napped length and fiber dispersion state are good.

  X: Napped length is good, but fiber dispersion is poor.

  XX: Napped length is short and defective.

XXX: There is almost no napping and it is a remarkable defect.
(5) 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 selected at random, and the fiber diameter was selected. It was calculated by measuring and calculating the average value.
(6) Fineness CV
The cross section in the thickness direction inside the nonwoven fabric or sheet is observed with a scanning electron microscope (SEM), and from the photograph, the fiber diameter of the ultrafine fibers constituting one bundle of bundle fibers is measured, and the fiber Converted from the diameter to the fineness of each single fiber, 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.
(7) Brush wear reduction A circular brush (nylon yarn 9700) in which 100 nylon yarns having a length of 11 mm and a diameter of 0.4 mm are aligned to form a bundle of 97 concentric circles in a 110 mm diameter circle. The surface of a circular sample (diameter 45 mm) of a napped leather-like sheet was worn under the conditions of a load of 8 pounds (about 3629 g), a rotation speed of 65 rpm, and a rotation frequency of 45 times. The change in weight was defined as brush wear reduction.
(8) Durability-Hydrolysis resistance-
After applying the forced degradation treatment to the napped leather-like sheet-like material obtained by using a constant temperature and humidity chamber manufactured by Davai Espec Co., Ltd. for 10 weeks in an atmosphere at a temperature of 70 ° C. and a relative humidity of 95%, James H. as a Martindale abrasion tester. Heal & Co. Using the model 406 manufactured by Abrasive Cross SM25 manufactured by the same company as a standard worn cloth, a load equivalent to 12 kPa was applied, and the appearance of the sample after rubbing under the condition of 20,000 times of wear was visually observed. evaluated. The evaluation criteria were grade 5 when the appearance of the sample did not change at all before friction and grade 1 when many pills were generated, and the grade was divided into 0.5 grades. Moreover, the pass level in this invention was made into the 4th grade.
(9) Durability-Light resistance-
Using the xenon weather meter manufactured by Suga Test Instruments Co., Ltd. using a 150 W / m ² xenon lamp, the napped leather-like sheet-like material thus obtained is subjected to forced deterioration treatment by irradiating light with a wavelength of 300 to 400 nm for 144 hours. After applying, James H. as a Martindale abrasion tester. Heal & Co. Using the model 406 manufactured by Abrasive Cross SM25 manufactured by the same company as a standard worn cloth, a load equivalent to 12 kPa was applied, and the appearance of the sample after rubbing under the condition of 20,000 times of wear was visually observed. evaluated. The evaluation criteria were grade 5 when the appearance of the sample did not change at all before friction and grade 1 when many pills were generated, and the grade was divided into 0.5 grades. Moreover, the pass level in this invention was made into the 4th grade.
[Notation of chemical substances]
The meanings of the abbreviations of chemical substances used in each example and comparative example are as follows.
MDI: 4,4′-diphenylmethane diisocyanate
EG: Ethylene glycol
DMF: N, N-dimethylformamide
EHG: polycarbonate diol having a number average molecular weight of 2,000 derived from 2-ethyl-1,3-hexanediol PHC: polycarbonate diol having a number average molecular weight of 2,000 derived from 1,6-hexanediol PHMPC: Copolymer polycarbonate diol having a number average molecular weight of 2,000 derived from 1,6-hexanediol and 3-methyl-1,5-pentanediol represented by the formula (4)

(In the formula, y and z are positive integers and are random copolymers. R is either (CH ₂ ) ₆ or (CH ₂ ) ₂ —CH (CH ₃ ) — (CH ₂ ) ₂ . Represents an aliphatic hydrocarbon group)
PTMG: Polytetramethylene glycol PCL having a number average molecular weight of 2,000: Polycaprolactone diol having a number average molecular weight of 2,000 [Example 1]
60 parts by weight of EHG as the polycarbonate diol (A), 40 parts by weight of PHMPC as the polycarbonate diol (B), and MDI as the organic diisocyanate total amount of polyol {(A) + (B)}: MDI molar ratio is 1: 3 In this way, DMF is charged into a four-necked separable colben with a cooling tube as a solvent, stirred and reacted at 40 to 60 ° C. in a nitrogen atmosphere, and EG as a chain extender is diluted with DMF in a state of 50 to 50- After making it drop-react at 60 degreeC, it diluted gradually with DMF and the polyurethane solution I of 25% of solid content was obtained about 10 hours afterward. The gel point was 3.5 mL.
The release paper was knife-coated with a clearance of 150 μm and immersed in an aqueous solution with a DMF concentration of 30% at 30 ° C. to wet-solidify the polyurethane to obtain a film of the polyurethane composition of the present invention.

The flexibility of the membrane was very flexible and the wear resistance was very good.
[Example 2]
A polyurethane solution II having a solid content of 25% was obtained in the same manner as in Example 1 except that 80 parts by weight of EHG as the polycarbonate diol (A) and 20 parts by weight of PHMPC as the polycarbonate diol (B) were used. The gel point was 2.6 mL.

The film of the polyurethane composition of the present invention obtained in the same manner as in Example 1 was very flexible and had good wear resistance.
[Example 3]
A polyurethane solution III having a solid content of 25% was obtained in the same manner as in Example 1 except that 20 parts by weight of EHG as the polycarbonate diol (A) and 80 parts by weight of PHMPC as the polycarbonate diol (B) were used. The gel point was 5.4 mL.

The film of the polyurethane composition of the present invention obtained in the same manner as in Example 1 was flexible and very good in wear resistance.
[Example 4]
A polyurethane solution IV having a solid content of 25% was obtained in the same manner as in Example 1 except that the polycarbonate diol (B) was changed to PHC. The gel point was 3.9 mL.

The film of the polyurethane composition of the present invention obtained in the same manner as in Example 1 was flexible and very good in wear resistance.
[Comparative Example 1]
A polyurethane solution V having a solid content of 25% was obtained in the same manner as in Example 1 except that 100 parts by weight of PHMPC was used as the polyol. The gel point was 6.6 mL.

The film of the comparative polyurethane composition obtained in the same manner as in Example 1 had good abrasion resistance but was flexible.
[Comparative Example 2]
A polyurethane solution VI having a solid content of 25% was obtained in the same manner as in Example 1 except that 100 parts by weight of PHC was used as the polyol. The gel point was 7.3 mL.

The film of the comparative polyurethane composition obtained in the same manner as in Example 1 had very good abrasion resistance but poor flexibility.
[Comparative Example 3]
A polyurethane solution VII having a solid content of 25% was obtained in the same manner as in Example 1 except that 70 parts by weight of PHC and 30 parts by weight of PCL were used for the polyol. The gel point was 7.0 mL.

The film of the comparative polyurethane composition obtained in the same manner as in Example 1 had good abrasion resistance but was flexible.
[Comparative Example 4]
A polyurethane solution VIII having a solid content of 25% was obtained in the same manner as in Example 1 except that 70 parts by weight of PHC and 30 parts by weight of PTMG were used for the polyol. The gel point was 5.5 mL.

The film of the comparative polyurethane composition obtained in the same manner as in Example 1 was flexible but had poor wear resistance.
[Comparative Example 5]
A polyurethane solution IX having a solid content of 25% was obtained in the same manner as in Example 1 except that 70 parts by weight of PTMG and 30 parts by weight of PCL were used for the polyol. The gel point was 3.1 mL.

The film of the comparative polyurethane composition obtained in the same manner as in Example 1 was flexible but had poor wear resistance.
[Examples 5 to 8, Comparative Examples 6 to 10]
Sea-island composite fibers were spun at a composite ratio of 55% by weight of sea component and 45% by weight of island component, using polystyrene as the sea component, polyethylene terephthalate as the island component, and a sea-island type composite base having 16 islands. Thereafter, stretching, crimping, and cutting were performed to obtain a nonwoven fabric raw cotton.

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

  This nonwoven fabric made of sea-island type composite fibers 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 is immersed in the polyurethane solutions I to IX (concentration: 12% by weight) obtained in any of Examples 1 to 4 and Comparative Examples 1 to 5 described above, and the amount of the polyurethane solution adhered is adjusted with a squeeze roll. After that, 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 the sheet-like material of the present invention.

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

  The evaluation results of the obtained sheet are summarized in Table 2.

Claims (12)

A polyurethane composition comprising a carbonate structure represented by the general formula (1) in a molecular chain.

(In the formula, R ₁ is an aliphatic hydrocarbon group having 1 to 4 carbon atoms, R ₂ is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and the total number of carbon atoms of R ₁ and R ₂ is 4 or more and 7 or less. Moreover, x is a positive integer of 2 to 20.) The polyurethane composition according to claim 1, further comprising a carbonate structure represented by the general formula (2) in a molecular chain.

(Wherein R ₃ and R ₄ are aliphatic hydrocarbon groups having 3 to 6 carbon atoms, which may be the same or different. Y and z are 0 or a positive integer, and 3 ≦ y + z ≦ 30 is satisfied.) A polycarbonate diol (A) having hydroxyl groups at both ends of a molecular chain having a carbonate skeleton represented by the general formula (1), and a polycarbonate having hydroxyl groups at both ends of a molecular chain having a carbonate skeleton represented by the general formula (2) The polyurethane composition according to claim 1 or 2, which has a structure obtained by a reaction of the diol (B), an organic diisocyanate, and a chain extender. The polyurethane composition according to any one of claims 1 to 3, wherein the carbonate structure represented by the general formula (1) is a carbonate structure represented by the general formula (3).

(Wherein x is a positive integer of 2 to 20) _{4. At} least one of R ₃ and R _{4 in} the formula represented by the general formula (2) is an aliphatic hydrocarbon group in which a methyl group or an ethyl group is branched. The polyurethane composition described in 1. Sheet-like material comprising 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 and an elastic resin binder mainly composed of polyurethane existing in the internal space The sheet is characterized in that the polyurethane is any one of claims 1 to 5. The sheet-like product according to claim 6, wherein the ultrafine fibers are polyester. The sheet-like material according to claim 6 or 7, wherein the elastic resin binder does not substantially exist inside the fiber bundle of ultrafine fibers. The sheet-like material according to any one of claims 6 to 8, wherein the elastic resin binder 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 6-9 characterized by the above-mentioned. The sheet-like material according to any one of claims 6 to 10, wherein the sheet-like material has napped fibers of at least one surface. The interior material characterized by using the sheet-like material in any one of Claims 6-11 as a skin material.