JP4973265B2 - Manufacturing method of sheet and sheet - Google Patents

Description

  The present invention provides a sheet-like product having a soft texture and good appearance quality, and in a method for producing a sheet-like product having little environmental load and hardly using an organic solvent in the production process. The present invention relates to a method for producing a sheet-like material having a good overall yield in all steps, and a sheet-like material obtained thereby.

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

  As an effort to reduce environmental impact, technologies for preventing the outflow of organic solvents used in the manufacturing process to the environment are being studied on a global scale.

  The manufacturing process of a general sheet-like material is as follows. That is, a process of generating a fine fiber by treating a nonwoven fabric composed of ultrafine fiber-generating fibers with an organic solvent, and impregnating the nonwoven fabric with an organic solvent solution of polyurethane, and then the fiber sheet is a non-solvent of polyurethane Many combinations of steps in which polyurethane is wet-solidified by dipping in water or an organic solvent aqueous solution are employed.

  As such an organic solvent, toluene, trichloroethylene or the like is used in the fiber ultrafine process, and a water-miscible organic solvent such as N, N′-dimethylformamide is used as the organic solvent for polyurethane.

  However, since organic solvents are highly harmful to the human body and the environment, there is a strong demand for the realization of a technique that does not use organic solvents in the production of sheet-like materials.

  As a specific solution to this requirement, for example, with respect to the fiber ultrafine process, an alkaline aqueous solution, hot water, etc. are used by using an alkaline aqueous solution soluble component, a hot water soluble component, etc. Regarding the use of an organic solvent of polyurethane by performing ultrafine fiber, a method using a polyurethane aqueous dispersion in which polyurethane is dispersed in water instead of the conventional organic solvent type polyurethane has been studied.

  For example, a method for producing a leather-like sheet has been proposed in which a nonwoven fabric composed of fibers capable of alkaline sea removal is impregnated with a heat-sensitive gelling polyurethane aqueous dispersion, and then seawater is removed with an aqueous alkaline solution (for example, Patent Document 1). reference). By using a polyurethane aqueous dispersion with heat-sensitive gelling properties, the migration of polyurethane during drying after impregnation with polyurethane is suppressed, and the texture of the leather-like sheet is softened. Since a surfactant is used for imparting water, stickiness due to bleeding of the surfactant is likely to occur, and there is a problem that a washing step is required after impregnation with polyurethane. In addition, since the surfactant is present, fusion between polyurethane emulsions during film formation is likely to be inhibited, and the film strength of the polyurethane film may be reduced to reduce the wear resistance of the sheet-like material.

  Furthermore, in this proposal, after impregnating with polyurethane, the fiber is made ultrafine by treating with an alkaline aqueous solution. However, since polyurethane is generally easily hydrolyzed to an alkaline aqueous solution, the polyol is mixed with polyether or polycarbonate. However, considering that the urethane bond and urea bond of polyurethane are easily hydrolyzed, it is not possible to suppress the drop-off of polyurethane during alkaline solution treatment. In addition, the strength and wear resistance of the sheet-like material are remarkably lowered, so that it is not practically sufficient.

  In addition, a manufacturing method in which a non-woven fabric is impregnated after a crosslinking agent is added in advance to an aqueous polyurethane dispersion (see, for example, Patent Document 2). By using a crosslinking agent in combination, the durability of the polyurethane-impregnated nonwoven fabric is improved. However, when production is considered, adding a crosslinking agent to a polyurethane aqueous dispersion and storing it easily causes gelation over time, and the pot life is short. It becomes.

  In addition, for the purpose of softening the polyurethane-impregnated nonwoven fabric, a production method has been proposed in which polyvinyl alcohol is imparted to a nonwoven fabric made of alkali-deseasable fiber and then impregnated with a polyurethane water dispersion (for example, Patent Document 3). reference). By imparting polyvinyl alcohol, reinforcement of the nonwoven fabric properties during processing and softening of the polyurethane-impregnated nonwoven fabric by removal after removal of the polyurethane water dispersion (removal of the polyvinyl alcohol) are achieved. However, it is necessary to go through a step of applying polyvinyl alcohol and a step of removing (removing the polyvinyl alcohol), and there is a problem that the manufacturing process of the leather-like sheet is very long and the manufacturing cost is high.

  On the other hand, polyester-based fibers are often applied to sheet-like materials that are developed especially for applications requiring light resistance. Among them, polyethylene terephthalate is excellent in terms of versatility and practicality, and is preferably used. Yes.

  In general, polyethylene terephthalate is produced from terephthalic acid or an ester-forming derivative thereof and ethylene glycol. In a commercial process for producing a high molecular weight polymer, an antimony compound is widely used as a polycondensation catalyst. However, polymers containing antimony compounds have some undesirable properties as described below.

For example, when a polymer obtained using an antimony catalyst is melt-spun into a fiber, it is known that an antimony catalyst residue is deposited around the die hole. If this deposition progresses, it will cause a defect in the raw cotton, so that it must be removed in a timely manner. The deposition of the antimony catalyst residue is considered to be due to the antimony compound in the polymer being transformed in the vicinity of the die and partially vaporizing and dissipating, and then a component mainly composed of antimony remains in the die.
In addition, the antimony catalyst residue in the polymer tends to become relatively large particles, and it has undesirable characteristics such as foreign matter, increasing the filter pressure of the filter during molding, and causing yarn breakage during spinning. This contributes to a decrease in operability.

  From the above background, when considering improving the overall yield in all processes including spinning to obtain a sheet-like material, the meaning of improving the operability of spinning is large, and the antimony content is high. There is a demand for a sheet-like product using raw cotton made of polyester which is little or not contained.

  However, it is not easy to substitute antimony as a polymerization catalyst for polymers, and studies are underway to clear technical problems. As an alternative to the antimony-based catalyst, germanium-based, titanium-based, and aluminum-based materials can be given. However, the germanium-based catalyst has almost the same catalytic activity as that of the antimony-based catalyst, but the amount of the germanium-based catalyst is very low. Therefore, there is a problem that the cost is high when mass production of the polymer is considered. In addition, the titanium and aluminum systems are relatively inexpensive, but have a problem that the color tone of the resulting polymer is yellowish and inferior in heat resistance.

  Considering the production of polymers, since the cost is relatively low, studies with titanium-based catalysts are mainly underway. For example, a long fiber nonwoven fabric using polyester using a titanium-based catalyst has been proposed (see, for example, Patent Document 4). This proposal is premised on split-type split yarns of polyester and nylon, and no proposal has been made for ultrafine fiber-generating fibers containing an elution component. There is also no proposal regarding a sheet-like material in which a nonwoven fabric is impregnated with a polymer elastic body.

As described above, in a manufacturing process that uses almost no organic solvent as an effort to reduce environmental impact, a manufacturing method of a sheet-like material that improves the overall yield in the entire manufacturing process, and a sheet-like material are not obtained. Currently.
JP 2001-55670 A JP 2005-248415 A JP 2002-317386 A Japanese Patent Laid-Open No. 2004-300652

  In view of the background of such conventional technology, the object of the present invention is a method for producing a sheet-like material having a soft texture and good appearance quality, and having little use of an organic solvent in the production process and having a small environmental load. Another object of the present invention is to provide a method for producing a sheet-like material having a good overall yield in all steps from spinning to obtaining a sheet-like material, and a sheet-like material obtained thereby.

In order to achieve the above object, the present invention has the following configuration. That is,
[1] A method for producing a sheet-like product comprising the following steps (1) to (3) in this order.
(1) A copolymerized polyester comprising terephthalic acid and ethylene glycol as main components and containing 5 to 12 mol% of sodium 5-sulfoisophthalate with respect to the total acid component, wherein the copolymerized polyester is titanium. atom containing 0.1ppm or 100ppm or less, and the step of producing a nonwoven fabric using ultrafine fiber-generating fibers obtained by using containing no antimony atom, or 30ppm copolymerized polyester containing less at least as one component,
(2) The self-emulsifying polyurethane in the nonwoven fabric produced in (1) has a silicon atom content in the molecular structure of more than 0% by weight and less than 1% by weight based on the weight of the polyurethane. Impregnating a self-emulsifying polyurethane water dispersion to give a self-emulsifying polyurethane,
(3) A step of treating the nonwoven fabric provided with the self-emulsifying polyurethane in (2) with an alkaline aqueous solution to express ultrafine fibers.

  [2] The method for producing a sheet-like product according to [1], wherein the ultrafine fiber is a polyester-based ultrafine fiber.

[3] The sheet according to [2], wherein the polyester-based ultrafine fiber is an ultrafine fiber containing 0.5 ppm to 150 ppm of titanium atoms and not containing antimony atoms or containing 30 ppm or less. A method for producing a product.

  [4] The method for producing a sheet-like product according to any one of [1] to [3], wherein a sea-island composite fiber is used as the ultrafine fiber generating fiber.

  [5] The sheet according to any one of [1] to [4], wherein the self-emulsifying polyurethane water dispersion does not contain an organic solvent or contains 1% by weight or less. A method for producing a product.

[ 6 ] The self-emulsifying polyurethane has 3 to 30% by weight of polyethylene glycol with respect to the total weight of the polyurethane, according to any one of the above [1] to [ 5 ] Manufacturing method of sheet-like material.

[ 7 ] The method for producing a sheet-like material according to any one of [1] to [ 6 ], wherein the self-emulsifying polyurethane has a nonionic emulsifier.

[ 8 ] A sheet-like material in which a self-emulsifying polyurethane having a crosslinked structure by a siloxane bond in a self-emulsifying polyurethane molecular structure is contained in a non-woven fabric composed of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less. a is, contain ultrafine fibers 0.5ppm least 150ppm or less titanium atoms, and contain no antimony atom, or 30ppm contain less, further wherein the self-emulsifiable polyurethane and the microfine fibers is substantially close contact And the self-emulsifying polyurethane part has a non-porous structure.

  According to the present invention, in a method for producing a sheet-like material having a soft texture and good appearance quality and having a small environmental impact in the production process, the sheet-like material is obtained from spinning. It is possible to provide a method for producing a sheet-like material having a good overall yield in all steps until it is obtained, and a sheet-like material obtained thereby.

The manufacturing method of the sheet-like object of the present invention has the following steps (1) to (3) in this order.
(1) A copolymerized polyester comprising terephthalic acid and ethylene glycol as main components and containing 5 to 12 mol% of sodium 5-sulfoisophthalate with respect to the total acid component, wherein the copolymerized polyester is titanium. atom containing 0.1ppm or 100ppm or less, and the step of producing a nonwoven fabric using ultrafine fiber-generating fibers obtained by using containing no antimony atom, or 30ppm copolymerized polyester containing less at least as one component,
(2) The self-emulsifying polyurethane in the nonwoven fabric produced in (1) has a silicon atom content in the molecular structure of more than 0% by weight and less than 1% by weight based on the weight of the polyurethane. Impregnating a self-emulsifying polyurethane water dispersion to give a self-emulsifying polyurethane,
(3) A step in which the non-woven fabric of (2) provided with the self-emulsifying polyurethane is treated with an alkaline aqueous solution to develop ultrafine fibers.

  By carrying out the steps (1) to (3) in order, the self-emulsifying polyurethane and the ultrafine fibers form a structure that is not substantially adhered, and a very flexible sheet-like material can be obtained.

  The sheet-like material referred to in the present invention has an excellent surface appearance such as suede like natural leather, nubuck, silver surface, and preferably has a smooth appearance such as suede or nubuck. It has touch and excellent lighting effects.

  As a means for obtaining ultrafine fibers constituting the nonwoven fabric, ultrafine fiber generating fibers are used. A nonwoven fabric in which ultrafine fibers are entangled can be obtained by performing ultrafine fiber after entanglement of ultrafine fiber generating fibers in advance.

  The ultrafine fiber generation type fiber is composed of at least two thermoplastic polymer components having different solubility in an alkaline aqueous solution as sea components and island components, and the sea components are dissolved and removed using an alkaline aqueous solution to remove the island components from ultrafine fibers. The sea-island type composite fiber and the two-component thermoplastic polymer component are arranged alternately in a radial or multi-layer cross section, and each component is peeled and divided to split into ultrafine fibers, etc. Can be adopted. Above all, the sea-island type composite fiber can provide an appropriate gap between island components, that is, between the ultrafine fibers inside the fiber bundle by removing the sea component, so from the viewpoint of flexibility and texture of the base material. preferable.

  For the sea-island type composite fiber, a sea-island type composite base is used, and a polymer inter-array system in which the two components of the sea and the island are mutually arranged and spun, and the mixed spinning in which the two components of the sea and the island are mixed and spun. Although a system etc. can be used, the sea island type composite fiber by a polymer array system is more preferable at the point from which the ultrafine fiber of uniform fineness is obtained.

  The different solubility in alkaline aqueous solution in the present invention is preferably such that the dissolution rate is different from 20 times to 1000 times under the condition for expressing ultrafine fibers, and is different from 40 times to 1000 times. Is more preferable. If it is less than 20 times, it is difficult to control the fineness of the thermoplastic polymer component having low solubility when developing the ultrafine fiber, which is not preferable.

  The dissolution rate in the alkaline aqueous solution can be calculated from the weight ratio obtained by treating the treatment time as 1 hour in accordance with the chemical resistance test (test solution: sodium hydroxide 10%) of JIS K6911 (1995).

  As a sea component of the sea-island type composite fiber having high solubility in an alkaline aqueous solution, from the viewpoint of the dissolution rate in alkaline aqueous solution and spinning stability, terephthalic acid and ethylene glycol are the main constituent components, and the total acid component is A copolyester containing 5-12 mol% sodium 5-sulfoisophthalate is used. The term “main component” as used herein means that about 50 mol% or more of all components is composed of terephthalic acid and ethylene glycol. The copolymer polyester may be not only a binary but also a ternary or higher multi-component copolymer as long as the solubility in an alkaline aqueous solution is within the range that does not hinder the production method of the present invention. As copolymerization components, polyesters such as polytrimethylene terephthalate and polybutylene terephthalate, sodium 5-sulfoisophthalate, polyethylene glycol, sodium dodecylbenzenesulfonate, bisphenol A compound, isophthalic acid, adipic acid, dodecadioic acid, cyclohexylcarboxylic acid A copolymerized polyester obtained by copolymerizing 5 to 12 mol% of the above, polylactic acid, or the like can be used.

  The copolyester of the present invention contains 0.1 ppm or more and 100 ppm or less of titanium atoms or aluminum atoms. The titanium atom or the aluminum atom here is derived from a catalyst for polymerizing the copolymer polyester. From the heat resistance point of the copolyester, it is more preferably 0.5 ppm or more and 80 ppm or less, and further preferably 1 ppm or more and 50 ppm or less.

  Moreover, the said copolyester of this invention does not contain an antimony atom, or contains 30 ppm or less. By setting it within this range, it is possible to obtain a relatively inexpensive polymer with little occurrence of base stains during spinning. More preferably, it does not contain antimony atoms or contains 20 ppm or less. An antimony atom here originates in the catalyst at the time of superposing | polymerizing copolyester.

  The metal element content in the polymer is determined by fluorescent X-ray analysis or ICP (inductively coupled plasma) emission analysis.

  When the target polymer contains titanium dioxide particles or silicon oxide particles, the following pretreatment is performed to remove the influence of the particles, and then X-ray fluorescence analysis or ICP emission analysis is performed. . That is, the polymer is dissolved in orthochlorophenol, and the viscosity of the polymer solution is adjusted with chloroform as necessary, and then the particles are precipitated with a centrifuge. Thereafter, only the supernatant liquid is collected by a gradient method, and the polymer is reprecipitated by adding acetone, filtered and washed to obtain a polymer from which particles are removed. Metal analysis is performed on the polymer from which the particles obtained by the above pretreatment have been removed.

As a catalyst for polymerizing the copolymerized polyester of the present invention, all of the following reactions (A) to (C) in a polymer synthesized from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof: Alternatively, a compound that contributes substantially to the promotion of some elementary reactions can be used.
(A) an esterification reaction that is a reaction between a dicarboxylic acid component and a diol component;
(B) a transesterification reaction which is a reaction between an ester-forming derivative component of a dicarboxylic acid and a diol component;
(C) A polycondensation reaction in which the ester reaction or transesterification reaction is substantially completed, and the resulting polyethylene terephthalate low polymer is highly polymerized by a dediol reaction.

  As the titanium compound catalyst in the present invention, in addition to titanium alkoxide compounds such as tetraisopropyl titanate and tetrabutyl titanate, composite oxides and titanium complex compounds whose main metals are titanium and silicon are preferably used.

  Here, the composite oxide is a compound having two or more main elements that form an oxide together with oxygen. There are two kinds of elements of titanium and silicon with respect to oxygen atoms. Three kinds of elements form one compound.

  When the main metal is a composite oxide composed of titanium and silicon, the ratio of Ti and Si is not particularly limited, but if the molar ratio of the two metals (Ti / Si) is 20/80 or more, the activity as a polymerization catalyst Is preferable because it can be polymerized in a small amount. More preferably, Ti / Si = 98/2 to 50/50.

  Examples of the titanium complex include those in which an alkoxytitanium compound is used as a base material and various complexing agents are bound thereto. Specific examples of the complexing agent include hydroxycarboxylic acids such as lactic acid, glycolic acid, citric acid, tartaric acid and malic acid, glycine, bishydroxyethyl glycine, hydroxyethyl glycine, nitrilotripropionic acid, carboxyimino dicarboxylic acid. Acetic acid, carboxymethyliminodipropionic acid, diethylenetriaminopentaacetic acid, triethylenetetraminohexaacetic acid, iminodiacetic acid, iminodipropionic acid, hydroxyethyliminodiacetic acid, hydroxyethyliminodipropionic acid, methoxyethyliminodiacetic acid, alanine N-acetic acid, alanine-N, N-diacetic acid, β-alanine-N-acetic acid, β-alanine-N, N-diacetic acid, serine-N-acetic acid, serine-N, N-diacetic acid, isoserine-N N-diacetic acid, aspartic acid-N-acetic acid, aspartic acid-N, N -Aminocarboxylic acids such as diacetic acid, glutamic acid-N-acetic acid, glutamic acid-N, N-diacetic acid, nitrogen-containing compounds such as aspartic acid, glutamic acid, leucine, isoleucine, triethanolamine, acetylacetonate, acetoacetate, etc. Can be mentioned.

Further, among titanium complexes, a titanium complex using a compound having two or more carboxylic acids in one molecule as a complexing agent is preferable because the color tone of the resulting copolyester is good.
Examples of the aluminum compound catalyst in the present invention include aluminum hydroxide, aluminum chloride, aluminum hydroxide chloride and the like as inorganic aluminum compounds, and examples of aluminum alcoholate include aluminum ethylate, aluminum isopropylate, aluminum tri-n-butylate, Examples include aluminum tri-sec-butyrate, aluminum tri-tert-butyrate, mono-sec-butoxyaluminum diisopropylate, and the aluminum chelates include ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), alkyl acetoacetate Acetate aluminum diisopropylate, aluminum monoacetyl acetate bis (ethyl acetoacetate), aluminum Minium tris (acetyl acetate), aluminum monoisopropoxy monooroxyethyl acetoacetate, aluminum acetylacetonate, etc. are mentioned. Aluminum acetate, aluminum acetate, aluminum benzoate, aluminum lactate, aluminum laurate, aluminum stearate Etc.

  Examples of the antimony compound catalyst in the present invention include antimony oxides such as antimony trioxide, antimony pentoxide, and the like, and antimony carboxylic acids such as antimony acetate, antimony oxalate, and potassium antimony tartrate, and antimony alkoxides. , Antimony tri-n-butoxide, antimony triethoxide and the like.

  The copolymerized polyester may be added with particles for the purpose of reducing friction with contact materials such as various guides and rollers in the molding process and improving process passability. The kind of particle | grains is not specifically limited, Any of conventionally well-known particle | grains can be used. Specifically, for example, inorganic particles such as silicon dioxide, titanium dioxide, calcium carbonate, barium sulfate, aluminum oxide, and zirconium oxide, and organic polymer particles such as crosslinked polystyrene can be used. Among these particles, titanium dioxide particles are preferable because of their good dispersibility in the polymer and relatively low cost.

  The addition amount and particle diameter of the particles in the present invention with respect to the polymer are not particularly limited, but the process passability is 0.01 to 10% by weight with respect to the polyester composition and the average particle diameter is in the range of 0.05 to 5 μm. Good and preferable.

  In addition, the copolymer polyester includes pigments such as carbon black, surfactants such as alkylbenzene sulfonates, conventionally known antioxidants, anti-coloring agents, light-proofing agents, charging agents, and the like within a range that does not impair the object of the present invention. An inhibitor or the like may be added.

  In the present invention, in the ultrafine fiber-generating fiber, the polymer of ultrafine fiber (island component in the case of sea-island type composite fiber) that appears after treatment with an alkaline aqueous solution includes polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene-2, Polyesters such as 6-naphthalenedicarboxylate, polyamides such as 6-nylon and 66-nylon, acrylic, polyethylene, and polypropylene can be used. Among them, it is more preferable to use a polyester-based polymer such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and particularly preferably polyethylene from the viewpoint of the strength of the ultrafine fiber, the dimensional stability of the sheet-like material, light resistance, and dyeability. It is terephthalate.

  The polyester polymer preferably contains 0.5 ppm or more and 150 ppm or less of titanium atoms or aluminum atoms. The titanium atom or aluminum atom here is derived from a catalyst for polymerizing the polyester polymer. From the viewpoint of heat resistance of the polyester-based polymer, the titanium atom or aluminum atom is preferably contained in an amount of 0.5 ppm to 80 ppm, more preferably 1 ppm to 50 ppm.

  Moreover, it is preferable that the said polyester-type polymer does not contain an antimony atom, or contains 30 ppm or less. By setting it within this range, it is possible to obtain a relatively inexpensive polymer with little occurrence of base stains during spinning. More preferably, it does not contain antimony atoms or contains 20 ppm or less. The antimony atom here is derived from a catalyst for polymerizing the polyester polymer.

  After spinning the above-described ultrafine fiber-generating fiber, it is preferably 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 by 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. Further, in the step of obtaining a nonwoven fabric by entanglement of fibers, the nonwoven fabric may be constituted by mixing ultrafine fibers of different materials, or the strength of the nonwoven fabric may be improved by inserting a woven fabric or a knitted fabric. The average single fiber fineness of the fibers constituting the woven fabric or knitted fabric is not particularly limited, and may be an ultrafine fiber of 0.001 dtex or more and 1 dtex or less.

  The obtained non-woven fabric may be subjected to shrinkage treatment by hot water, steam treatment, hot press, etc. in order to improve the fineness of the fibers.

  Further, the non-woven fabric may be obtained by half-cutting (dividing into two sheets) or dividing into several sheets in the thickness direction of the non-woven fabric before applying the self-emulsifying polyurethane water dispersion.

  In applying the self-emulsifying type polyurethane water dispersion to the nonwoven fabric, the nonwoven fabric is impregnated with the polyurethane water dispersion or applied to dry heat solidification, and the nonwoven fabric is impregnated with the polyurethane water dispersion and then wet heat solidified. There are a method of heat drying, a method of wet coagulation in hot water and heat drying, and a combination thereof, but there is no particular limitation.

  If the drying temperature is too low, the drying time will be long, and if it is too high, it may cause thermal degradation of the self-emulsifying polyurethane, so that it is preferably 80 ° C. or higher and 180 ° C. or lower. More preferably, it is 90 ° C or higher and 160 ° C or lower.

  The polyurethane water dispersion used in the production of the present invention is a polyurethane water dispersion which is dispersed in water as an emulsion, and is preferably a self-emulsifying polyurethane water dispersion which does not contain an emulsifier such as a surfactant.

  When a forced emulsification-type polyurethane aqueous dispersion containing an emulsifier such as a surfactant is used, the surface of the obtained sheet-like material generates stickiness due to the emulsifier, so a cleaning step is required, and the processing step Will increase the cost. In addition, in the forced emulsification type polyurethane water dispersion, the water resistance of the polyurethane film formed into a film is lowered due to the presence of the emulsifier, and therefore, in the dyeing of the sheet-like material containing polyurethane, the polyurethane is not dropped into the dyeing liquid. Since it occurs, it is not preferable.

  The polyurethane water dispersion used in the present invention is a self-emulsifying polyurethane water dispersion, but the self-emulsifying polyurethane water dispersion is a polyurethane in which water is stably dispersed without using an emulsifier such as a surfactant. It is an aqueous dispersion and has a hydrophilic so-called internal emulsifier in the self-emulsifying polyurethane molecular structure.

  The self-emulsifying polyurethane is usually handled in a state of being dispersed in water, and can be obtained from the manufacturer in this state. This is because once dried, it cannot be dispersed in water again.

  Internal emulsifiers are any of cationic systems such as quaternary amine salts, anionic systems such as sulfonates and carboxylates, nonionic systems such as polyethylene glycol, combinations of cationic systems and nonionic systems, and combinations of anionic systems and nonionic systems. However, it is most preferable to use a nonionic internal emulsifier that does not cause the yellowing due to light and does not cause any harmful effects due to the neutralizing agent.

  That is, when an anionic internal emulsifier is used, a neutralizing agent is required. For example, the neutralizing agent is a tertiary amine such as ammonia, triethylamine, triethanolamine, triisopropanolamine, trimethylamine, or dimethylethanolamine. In some cases, amines are generated and volatilized by the heat generated during film formation and drying, and released outside the system. Therefore, it is indispensable to introduce an apparatus for recovering volatile amines in order to suppress atmospheric emissions and work environment deterioration. In addition, if the amine does not evaporate by heating and remains in the final product sheet, it may be discharged to the environment when the product is incinerated, but the nonionic internal emulsifier uses a neutralizing agent. Therefore, it is not necessary to introduce an amine recovery device, and there is no fear of remaining amine in the sheet. In addition, 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 self-emulsifying polyurethane part exhibits alkalinity when wet. However, since the nonionic internal emulsifier does not use a neutralizing agent, there is no need to worry about degradation due to hydrolysis of the self-emulsifying polyurethane.

  As the self-emulsifying polyurethane used in the present invention, those having a structure in which polyol, polyisocyanate, and chain extender are appropriately reacted in addition to the internal emulsifier can be used.

  As the polyol, a polycarbonate-based diol, a polyester-based diol, a polyether-based diol, a silicone-based diol, a fluorine-based diol, or a copolymer combining these may be used. Of these, polycarbonate diols and polyether diols are preferably used from the viewpoint of hydrolysis resistance, and polycarbonate diols are more preferable from the viewpoints of light resistance and heat resistance.

  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 the alkylene glycol include linear chains such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol. 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, 1,4 -Alicyclic diols such as cyclohexanediol, aromatic diols such as bisphenol A, glycerin, trimethylolpropane, pentaerythritol and the like. 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 polyisocyanate include aliphatic systems such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and aromatic systems such as diphenylmethane diisocyanate and tolylene diisocyanate, and these may be used in combination. Of these, aliphatic systems such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate are preferable from the viewpoint of light resistance.

  As the chain extender, amines such as ethylenediamine and methylenebisaniline, diols such as ethylene glycol, and polyamines obtained by reacting polyisocyanate with water can be used.

  The self-emulsifying polyurethane preferably contains a crosslinking component. By including a crosslinking component, the durability of the self-emulsifying polyurethane is dramatically improved. The crosslinking component may be obtained by using a crosslinking agent as an additive in the self-emulsifying polyurethane aqueous dispersion, and a compound having a functional group capable of crosslinking reaction, which is previously introduced into the molecular structure during the synthesis of the self-emulsifying polyurethane, An internal cross-linking agent may be used, but it is more preferable to use an internal cross-linking agent that can more uniformly cross-link the self-emulsifying polyurethane and improve the durability with a small amount.

  The crosslinking agent and the internal crosslinking agent are not particularly limited, and 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. Since polyurethane is easily cured and the texture of the sheet is hardened, it is preferably a compound having a silanol group from the viewpoint of balance between reactivity and flexibility.

  When silanol groups are introduced into the self-emulsifying polyurethane molecular structure as an internal cross-linking agent, the self-emulsifying polyurethane impregnated and solidified in the internal space of the nonwoven fabric has a cross-linked structure due to siloxane bonds. The durability such as hydrolysis resistance can be remarkably improved, which is preferable.

  The silanol groups in the self-emulsifying polyurethane containing silanol groups have sufficient water in the surroundings in the self-emulsifying polyurethane water dispersion, so that the silanol groups react with each other to form siloxane bonds. Is not stable and exists stably in water.

  Examples of the compound used for introducing the silanol group into the self-emulsifying polyurethane molecular structure include a compound containing an active hydrogen group capable of reacting with at least one isocyanate group and a hydrolyzable silicon group in one molecule. It is done.

  The hydrolyzable silicon group means a group in which a hydrolyzable group that is hydrolyzed by moisture is bonded to a silicon atom. Specific examples of the hydrolyzable group include a hydrogen atom, a halogen atom, and an alkoxy group. And generally used groups such as an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, an alkoxy group that has low hydrolyzability and is relatively easy to handle is preferable. The hydrolyzable group is bonded to one silicon atom in the range of 1 to 3, but from the reactivity of the hydrolyzable silyl group, water resistance, etc., those having 2 to 3 bonds are preferable. .

  Examples of the active hydrogen group capable of reacting with an isocyanate group include a mercapto group, a hydroxyl group, and an amino group.

  Hydrolyzable silicon group-containing compounds having a mercapto group as an active hydrogen group and an alkoxy group as a hydrolyzable group include, for example, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropylmethyl. Examples of the hydrolyzable silicon group-containing compound having an amino group as an active hydrogen group and an alkoxy group as a hydrolyzable group include dimethoxysilane and γ-mercaptopropylmethyldiethoxysilane. Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropyldimethoxysilane, γ- (2-aminoethyl) aminopropyldiethoxysilane, γ-aminopropyltrimethoxysila , .Gamma.-aminopropyltriethoxysilane, .gamma.-aminopropyl dimethoxysilane, and .gamma.-aminopropyl diethoxy silane. Among these, from the viewpoint of weather resistance and hydrolysis resistance, it is preferable to introduce a hydrolyzable silicon group into the middle part of the self-emulsifying polyurethane molecule, and further a hydrolyzable silicon group-containing compound having two or more active hydrogen groups Is preferred.

  The self-emulsifying polyurethane into which the hydrolyzable silicon group-containing compound has been introduced contains a crosslinked structure by siloxane bonds in a state of being impregnated and solidified in the internal space of the nonwoven fabric. Due to this cross-linked structure, the durability is remarkably improved, and furthermore, the polyurethane can be prevented from falling off from the sheet-like material in the treatment with the alkaline aqueous solution.

  Here, in order to form a siloxane bond, silanol groups directly bonded to the polymer need to be condensed. Therefore, the presence of a siloxane bond indicates that the silanol groups are condensed and a crosslinked structure that bonds the polymers.

  The content of silicon atoms in the polyurethane molecular structure indicating the amount of silanol groups contained in the silanol group-containing self-emulsifying polyurethane is preferably more than 0% by weight and 1% by weight or less based on the weight of the polyurethane. As the number of cross-linked structures due to siloxane bonds increases, the durability of the self-emulsifying polyurethane, such as hydrolysis resistance, is improved. However, if the amount is too large, the flexibility of the self-emulsifying polyurethane decreases. 0.5% by weight or less. The content of silicon atoms can be quantified by performing elemental analysis of the polyurethane component extracted from the self-emulsifying polyurethane liquid itself or a sheet-like material.

  The presence or absence of a siloxane bond can be confirmed by a peak due to the siloxane bond in the measurement of polyurethane by NMR.

  The self-emulsifying polyurethane aqueous dispersion used in the present invention may contain a water-soluble organic solvent in an amount of 1% by weight or less based on the aqueous dispersion for improving storage stability and film-forming property. It is preferable not to include an organic solvent in view of concerns such as the release of the organic solvent into the atmosphere due to heating during film formation and the remaining organic solvent in the final product.

  The amount of the organic solvent contained in the polyurethane water dispersion is different depending on the type of the organic solvent used in the dispersion medium gas chromatography analysis (HITACHI 263-50, column: solid water concentration polyurethane water dispersion used for impregnation. In the case of N, N-dimethylformamide, PEG20M is used.).

  The concentration of the self-emulsifying polyurethane aqueous dispersion (content of the self-emulsifying polyurethane relative to the self-emulsifying polyurethane aqueous dispersion) is 10% by weight or more and 50% by weight from the viewpoint of storage stability of the self-emulsifying polyurethane aqueous dispersion. The following is preferred.

  The self-emulsifying polyurethane aqueous dispersion preferably has a thermal gelation temperature. By having a thermal gelation temperature, it is possible to suppress the polyurethane migration phenomenon when the sheet is impregnated and dried. However, if the thermal gelation temperature is too low, there is a high possibility of gelation in the storage of the polyurethane water dispersion, and if it is too high, the migration phenomenon cannot be suppressed. preferable.

  The self-emulsifying polyurethane aqueous dispersion preferably has a heat-sensitive gelation property alone, but for the purpose of imparting the heat-sensitive gelation property to the self-emulsifying polyurethane water dispersion or lowering the heat-sensitive gelation temperature, Inorganic salts such as calcium, sodium sulfate, and potassium sulfate may be added.

  The self-emulsifying polyurethane preferably contains 3% by weight or more and 30% by weight or less of polyethylene glycol with respect to the total weight of the polyurethane, since the self-emulsifying polyurethane aqueous dispersion alone can exhibit heat-sensitive gelation. Moreover, it is preferable that polyethylene glycol is introduced into the self-emulsifying polyurethane as a nonionic internal emulsifier. If the polyethylene glycol content is too low, self-emulsification becomes difficult, and if it is too high, physical properties such as water resistance and polyurethane film strength are likely to deteriorate. Preferably they are 5 weight% or more and 20 weight% or less.

  In the present invention, the self-emulsifying polyurethane liquid may be used alone or in combination of two or more, or an aqueous dispersion of another polymer may be used in combination. Other polymer aqueous dispersions include, for example, acrylic and silicone aqueous dispersions and water-soluble polymers.

  Further, the self-emulsifying type polyurethane preferably has a weight reduction rate of 0% by weight or more and 5% by weight or less after treatment at 90 ° C. for 30 minutes in a 15 g / L sodium hydroxide aqueous solution. In the method for producing a sheet-like product according to the present invention, it is preferable that the weight loss of the self-emulsifying polyurethane due to dissolution and dropping in an alkaline aqueous solution is smaller. Therefore, the weight reduction rate is more preferably 0 wt% or more than 0 wt%. 4% by weight or less.

  The weight reduction rate (hydrolysis resistance) in the alkaline aqueous solution treatment was calculated as follows. The polyurethane water dispersion is impregnated into a polyethylene nonwoven fabric (vertical yarn 15 pieces / cm, transverse yarn 20 pieces / cm density) having a length of 10 cm and a width of 10 cm, and dried at 120 ° C. for 30 minutes, so that the weight of the nonwoven fabric is 75. A sheet with weight percent polyurethane is obtained. Next, the obtained sheet was immersed in a 15 g / L aqueous solution of sodium hydroxide, the weight after treatment at 90 ° C. for 30 minutes was measured, and the weight reduction rate was calculated in comparison with the weight before the immersion treatment.

  In addition, when applying a self-emulsifying polyurethane aqueous dispersion, a pigment such as carbon black, a dye, an antifungal agent, a light-resistant agent such as an antioxidant or an ultraviolet absorber, a flame retardant, a penetrating agent or a lubricant. Antiblocking agents such as silica and titanium oxide, antistatic agents, antifoaming agents such as silicone, fillers such as cellulose, polyurethane coagulation adjusting agents and the like can be added and used.

  In the method for producing a sheet-like product of the present invention, a self-emulsifying polyurethane is applied to a nonwoven fabric made of ultrafine fiber generating fibers, and then the ultrafine fibers are expressed by treating with an alkaline aqueous solution. The alkaline aqueous solution is not particularly limited, and an aqueous solution such as sodium hydroxide or potassium hydroxide, an ammonia salt, or the like can be used.

  The concentration of the aqueous alkali solution is not particularly limited as long as ultrafine fibers can be expressed, but is preferably 0.05 mol / L or more and 10 mol / L or less.

  The treatment with an alkaline aqueous solution involves immersing a non-woven fabric made of ultrafine fiber-generating fibers after application of self-emulsifying polyurethane, and performing a squeezing liquid. In the case of a sea-island type composite fiber divided by physical force, the sea component dissolved in alkaline water is eluted to generate ultrafine fibers, so the method is not particularly limited, but for example, a liquid dyeing machine or A treatment using a scouring apparatus or the like, or a combination thereof is also included. The temperature and time in the treatment using a liquid dyeing machine are preferably 50 ° C. or higher and 140 ° C. or lower and 5 minutes or longer and 90 minutes or shorter, respectively.

  For the purpose of improving the expression of ultrafine fibers, heat treatment, steam treatment, treatment with addition of a penetrant such as a surfactant may be performed as appropriate, and treatment with an acidic aqueous solution having a pH of 3 or less is performed in advance. After performing, you may process by alkaline aqueous solution.

  In the manufacturing method of the sheet-like material of the present invention, at least one surface of the sheet-like material may be subjected to raising treatment, and a nap-like sheet-like material in which napped fibers are expressed can be used. The raising treatment for forming napping on the surface of the sheet-like material can be performed by a grinding method 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 treatment, 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 divided into half or several sheets in the sheet thickness direction before the raising treatment.

  You may dye | stain in the manufacturing method of the sheet-like material of this invention. As the dyeing method, it is preferable to use a liquid dyeing machine because the sheet-like material can be softened by giving a stagnation effect at the same time as the dyeing method. As the liquid dyeing machine, a normal liquid dyeing machine can be used.

  If the dyeing temperature is too high, the self-emulsifying polyurethane may be deteriorated. Conversely, if the dyeing temperature is too low, the dyeing to the fibers becomes insufficient. The following is preferable, and 110 ° C. or higher and 130 ° C. or lower is more preferable.

  The type of the dye is not particularly limited, and may be selected according to the ultrafine fiber constituting the nonwoven fabric. For example, the polyester ultrafine fiber is a disperse dye, and the polyamide ultrafine fiber is an acid dye or metal-containing dye. Dyes such as dyes, 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 a softener such as silicone, an antistatic agent, a water repellent, a flame retardant, and a light-resistant agent may be applied. The finishing treatment may be performed after dyeing or in the same bath as dyeing.

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

  The sheet-like material of the present invention is composed of a nonwoven fabric in which fiber bundles of ultrafine fibers are entangled and a self-emulsifying polyurethane existing in the internal space.

  The average single fiber fineness of the ultrafine fibers constituting the nonwoven fabric is important to be 0.001 dtex or more and 0.5 dtex or less from the viewpoint of the flexibility and napped quality of the sheet-like material. 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 the circular cross section and the irregular cross section are mixed, or when the fine cross-sections are mixed greatly, 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 the 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.

  In the nonwoven fabric according to the present invention, the self-emulsifying polyurethane existing in the internal space does not substantially adhere to the ultrafine fibers constituting the nonwoven fabric, and the self-emulsifying polyurethane has a nonporous structure. preferable. That is, since the ultrafine fibers and the self-emulsifying polyurethane are not substantially in close contact with each other, the self-emulsifying polyurethane does not hinder the movement of the ultrafine fibers, so that the sheet-like material becomes very flexible.

  Here, “substantially not in contact” means that when a scanning electron microscope (SEM) photograph of the cross section of the sheet-like material is observed at a magnification of 300 times, the self-emulsifying polyurethane is integrated with the ultrafine fibers. That is, it means that it can be confirmed that voids exist between the self-emulsifying polyurethane and the ultrafine fibers. Although it may be partially in contact, it basically means that there is a gap.

  In the present invention, “the state in which the ultrafine fiber and the self-emulsifying polyurethane are not substantially adhered” is a method for producing a non-woven fabric using the ultrafine fiber generating fiber using the above-described copolymer polyester as at least one component, After impregnating the nonwoven fabric with an aqueous polyurethane dispersion to give a self-emulsifying polyurethane, the state can be realized by treating with an alkaline aqueous solution to dissolve and remove the above-mentioned copolyester to develop ultrafine fibers. Is. In addition, by this method, a space | gap comes to exist between ultrafine fibers in an ultrafine fiber bundle. However, there may be a portion where the ultrafine fibers are in contact with each other.

  In addition, since the self-emulsifying polyurethane part has a non-porous structure, it is stronger in physical force such as stagnation than in the case of a porous structure, so that the pilling resistance and abrasion resistance of the sheet-like material are good. Become.

  “Non-porous structure” as used herein means that when a scanning electron microscope (SEM) photograph of a cross section of a sheet-like material is observed at a magnification of 300 times, pores of 5 μm or more cannot be seen in the self-emulsifying polyurethane part. That is, it means that the existence cannot be confirmed.

  Thus, “making the self-emulsifying polyurethane into a non-porous structure” means, for example, a method in which a nonwoven fabric is impregnated with the polyurethane water dispersion or applied and dry-heat solidified, after the nonwoven fabric is impregnated with the polyurethane water dispersion. The state can be realized by a method of heat-coagulation after heat and heat coagulation, a method of wet coagulation in hot water and heat-drying, and a combination thereof.

  In the sheet-like material of the present invention, the content of the self-emulsifying polyurethane with respect to the total weight of the substrate is preferably 20% by weight or more and 200% by weight or less. By making it 20% by weight or more, it is possible to obtain sheet strength and prevent the fibers from falling off, and by making it 200% by weight or less, it is possible to prevent the texture from becoming harder than necessary, and to achieve a desired good. Napping quality can be obtained. More preferably, it is 30 wt% or more and 180 wt% or less.

  The sheet-like material of the present invention includes various functional agents such as dyes, pigments, softeners, texture modifiers, anti-pilling agents, antibacterial agents, deodorants, water repellents, light proofing agents, and weathering agents. It may contain a functional drug.

  The sheet-like material of the present invention may be suitably used as a nap-like sheet-like material having ultra-fine fiber nappings on at least one side, and the sheet-like material may be dyed.

  The sheet-like material of the present invention includes furniture, chairs, 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, Industry such as casual shoes, sports shoes, men's shoes, women's shoes, uppers and trims of shoes, bags, belts, wallets, etc., clothing materials used for some of them, wiping cloth, polishing cloth, CD curtains, etc. It can be suitably used as a material for use.

  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) Intrinsic viscosity of polymer IV
Measurement was performed at 25 ° C. using orthochlorophenol as a solvent.

(2) Metal element content in polymer The metal element content in the polymer is determined by the X-ray fluorescence elemental analyzer (manufactured by Horiba, Ltd., MESA-500W type) or ICP (inductively coupled plasma) emission analyzer (Seiko Instruments). It was obtained by SPS1700).

  When the target polymer contains titanium dioxide particles or silicon oxide particles, the following pretreatment was performed to remove the influence of the particles, and then X-ray fluorescence analysis or ICP emission analysis was performed. . That is, the polymer was dissolved in orthochlorophenol, the viscosity of the polymer solution was adjusted with chloroform as necessary, and then the particles were precipitated with a centrifuge. Thereafter, only the supernatant liquid was collected by a gradient method, and the polymer was reprecipitated by adding acetone, filtered and washed to obtain a polymer from which particles were removed. Metal analysis was performed on the polymer from which the particles obtained by the above pretreatment were removed.

(3) Observation of deposits in the die The amount of deposits around the die holes 72 hours after spinning of the fibers was observed using a long focus microscope.
The state in which deposits were hardly recognized was judged as ◯, the state in which deposits were recognized but operable was judged as Δ, and the state in which deposits were found and yarn breakage frequently occurred was judged as ×.

(4) Amount of organic solvent contained in polyurethane water dispersion In polyurethane water dispersion of solid content concentration used for impregnation, gas chromatographic analysis of dispersion medium (263-50, manufactured by HITACHI, column: depending on the type of organic solvent, In the case of N, N-dimethylformamide, PEG20M was used.) The amount of the organic solvent contained was quantified.

(5) Confirmation of siloxane bond in self-emulsifying polyurethane and determination of silicon atom content In the measurement of polyurethane by NMR, the presence or absence of siloxane bond was confirmed by the peak due to siloxane bond. In addition, the content of silicon atoms was quantified by conducting elemental analysis of the sheet-like material, or the polyurethane extracted from the sheet-like material and the self-emulsifying polyurethane aqueous dispersion.

(6) Confirmation of polyethylene glycol In the measurement of polyurethane by NMR, it was calculated by comparing the areas of the peak caused by the reference substance and the peak caused by polyethylene glycol (for example, the proton of the ethylene chain portion adjacent to the oxygen atom). .

(7) Thermosensitive gelation temperature of polyurethane water dispersion 10 g of polyurethane water dispersion with a solid content concentration of 10% by weight is put in a test tube, heated in a constant temperature hot water bath at 95 ° C., and the polyurethane water dispersion is fluid. The temperature at which gelation / solidification occurs after loss of heat was defined as the thermal gelation temperature.

(8) Hydrolysis resistance of polyurethane (weight reduction rate)
The polyurethane water dispersion is impregnated into a polyethylene nonwoven fabric (vertical yarn 15 pieces / cm, transverse yarn 20 pieces / cm density) having a length of 10 cm and a width of 10 cm, and dried at 120 ° C. for 30 minutes, so that the weight of the nonwoven fabric is 75. A sheet provided with wt% polyurethane was obtained.
Next, the obtained sheet was immersed in a 15 g / L aqueous solution of sodium hydroxide, the weight after treatment at 90 ° C. for 30 minutes was measured, and the weight reduction rate was calculated in comparison with the weight before the immersion treatment.

(9) Average single fiber fineness When the cross-section of the ultrafine fiber is circular or elliptical, the scanning electron microscope (SEM) photograph of the surface of the sheet (or non-woven fabric) is taken at a magnification of 2000 times to obtain the ultrafine fiber. 100 are selected at random, the fiber diameter is measured, the specific gravity of the material polymer is converted into the fineness, and the average value of the 100 is further calculated. 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 the circular cross section and the irregular cross section are mixed, or when the fine cross-sections are mixed greatly, 100 are selected and calculated so that each has the same number.

(10) Fineness CV
The cross section inside the non-woven fabric or sheet-like material is observed with a scanning electron microscope (SEM) at a magnification of 2000 times, and from the photograph, the fiber diameter of the ultrafine fibers constituting one bundle of bundle fibers is measured. The value obtained by converting the fiber diameter to the fineness of each single fiber and 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.

(11) Sheet-like structure A cross-section inside the sheet-like article is observed with a scanning electron microscope (SEM) at a magnification of 300 times. From the photograph, the adhesion between the self-emulsifying polyurethane and the ultrafine fibers, the self-emulsifying polyurethane part Judged the structure.

(12) Flexibility Based on the method A (45 ° cantilever method) described in JIS L1096-8.19.1 (2005 version), 5 test pieces each having a size of 2 × 15 cm are produced in the vertical direction and the horizontal direction. 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 obtained.

(13) Appearance quality The surface quality of the sheet was evaluated by visual inspection and sensory evaluation as follows.
○: Napped length and fiber dispersion state are good.
Δ: Napped length is good, but fiber dispersion is poor.
X: There is almost no napped and it is inferior.

[Notation of chemical substances]
The meanings of the abbreviations of chemical substances used in each example and comparative example are as follows.
PET: Polyethylene terephthalate H12MDI: 4,4′-dicyclohexylmethane diisocyanate HDI: Hexamethylene diisocyanate MDI: 4,4′-diphenylmethane diisocyanate NMP: N-methylpyrrolidone DMF: N, N-dimethylformamide C5C6PC: 1,5-pentanediol Copolymer polycarbonate polyol PHC having a number average molecular weight of 2,000 derived from 1,6-hexanediol and polycarbonate diol having a number average molecular weight of 2,000 derived from 1,6-hexanediol 3MPC: 3-methylpentanediol Polycarbonate diol having a number average molecular weight of 2,000 derived from [Polyurethane type]
The composition of the polyurethane water dispersion used in Examples and Comparative Examples is as follows. The properties of each polyurethane are shown in Table 1.
(1) Self-emulsifying polyurethane water dispersion A (solid content concentration: 30% by weight)
Polyisocyanate: H12MDI
Polyol: C5C6PC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Water Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane-containing organic solvent: 0.05% by weight
(2) Self-emulsifying type polyurethane water dispersion B (solid content concentration: 30% by weight)
Polyisocyanate: H12MDI
Polyol: C5C6PC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Water Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane-containing organic solvent: 0.04% by weight
(3) Self-emulsifying type polyurethane water dispersion C (solid content concentration: 30% by weight)
Polyisocyanate: HDI
Polyol: C5C6PC
Internal emulsifier: dimethylolpropionic acid triethylamine salt Chain extender: water Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane-containing organic solvent: 0.08% by weight
(4) Self-emulsifying polyurethane water dispersion D (solid content concentration: 30% by weight)
Polyisocyanate: HDI
Polyol: 3MPC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Water Internal cross-linking agent: None Contained organic solvent: 0.07% by weight
(5) Solvent-based polyurethane E (solid content concentration: 10% by weight)
Polyisocyanate: MDI
Polyol: PHC
Internal emulsifier: None
Chain extender: Water Internal cross-linking agent: None Contained organic solvent: 100% by weight (solvent: DMF)
(6) Forced emulsification type polyurethane F (solid content concentration: 30% by weight)
Polyisocyanate: H12MDI
Polyol: PHC
Internal emulsifier: None External emulsifier: Nonionic surfactant Internal cross-linking agent: None Contained organic solvent: 0.09% by weight.

[Polymer type]
The composition of the polymer constituting the ultrafine fiber generating fiber used in the examples and comparative examples is as follows.

(1) Synthetic Example of Copolyester A A low polymer containing no catalyst produced from high-purity terephthalic acid and ethylene glycol according to a conventional method is melted and stirred at 250 ° C., and phosphoric acid is added to the melt with phosphorus atoms. It added so that it might be set to 20 ppm with respect to the copolyester composition obtained by conversion. Further, a 30 wt% ethylene glycol solution of lithium acetate dihydrate was added so that the lithium acetate dihydrate was 0.1 wt% with respect to the copolymerized polyester composition. Subsequently, a 40 wt% ethylene glycol dispersion liquid having a transesterification rate of 70% synthesized by transesterification of dimethyl ester of 5-sodium sulfoisophthalic acid and ethylene glycol was converted into a total acid component using 5-sodium sulfoisophthalic acid as a copolymerization component. Then, a 2 wt% ethylene glycol solution of dimethoxydiacetylacetonato titanate was added so that the content of titanium atoms in the resulting copolymerized polyester was 5 ppm. . Thereafter, while stirring the low polymer at 15 rpm, the reaction system was gradually heated from 250 ° C. to 280 ° C. and the pressure was reduced to 40 Pa. The time to reach the final temperature and final pressure was both 60 minutes. When the predetermined stirring torque is reached, the reaction system is purged with nitrogen, returned to normal pressure, the polycondensation reaction is stopped, discharged into cold water in the form of a strand, and immediately cut to obtain a copolymer polyester A having an IV of 0.50 dlg ^-1 . Pellets were obtained.

(2) Synthetic Example of Copolyester B Synthetic Example of Polyester A except that antimony trioxide was added in place of dimethoxydiacetylacetonato titanate so that the content of antimony atoms was 300 ppm in the resulting copolyester. Similarly, a copolyester B was obtained.

(3) Synthesis Example of Polyester C A low polymer containing no catalyst produced from high-purity terephthalic acid and ethylene glycol according to a conventional esterification reaction is melted and stirred at 250 ° C., and phosphoric acid is added to the melt. It added so that it might become 10 ppm with respect to the polyester composition obtained in conversion of a phosphorus atom. A 12 wt% ethylene glycol slurry of titanium oxide particles was added so that the titanium oxide particles were 0.1 wt% based on the polyester composition, and then a 5 wt% ethylene glycol solution of cobalt acetate tetrahydrate was added to the cobalt. 30 ppm of the polyester composition in terms of atoms and 5 wt% ethylene glycol solution of magnesium acetate tetrahydrate were added to 20 ppm with respect to the polyester composition in terms of magnesium atoms, and then dimethoxydiacetylacetonate. A 2 wt% ethylene glycol solution of titanate was added so that the content of titanium atoms was 10 ppm in the resulting polyester. Thereafter, while stirring the low polymer at 30 rpm, the reaction system was gradually heated from 250 ° C. to 285 ° C. and the pressure was reduced to 40 Pa. The time to reach the final temperature and final pressure was both 60 minutes. When the predetermined stirring torque is reached, the reaction system is purged with nitrogen, returned to normal pressure, the polycondensation reaction is stopped, discharged into cold water in the form of strands, and immediately cut to obtain polyester C pellets with an IV of 0.72 dlg ^-1. Obtained.

(4) Synthesis example of polyester D Polyester D was synthesized in the same manner as in the synthesis example of polyester C except that antimony trioxide was added instead of dimethoxydiacetylacetonate titanate so that the content of antimony atoms was 300 ppm in the obtained polyester. D was obtained.

[Example 1]
It is a form in which 36 parts of island component are contained in one filament in a proportion of 45 parts of polyester A as a sea component and 55 parts of polyester C as an island component, and an average fineness of 2.8 dtex of sea island type fiber. A staple (fiber length: 51 mm) was used to form a web through a card and a cross wrapper, and a nonwoven fabric (1) was formed by needle punching. In the melt spinning process, almost no deposits around the nozzle holes and no increase in filtration pressure were observed during spinning, and the spinning operability was good.

This non-woven fabric was shrunk by treating in hot water at 90 ° C. for 2 minutes and dried at 100 ° C. for 5 minutes. Next, impregnated with the self-emulsifying type polyurethane water dispersion A, and after wet heat treatment at 100 ° C. for 5 minutes, drying with hot air at a drying temperature of 125 ° C. for 10 minutes results in a polyurethane weight of 80% by weight with respect to the island component weight of the nonwoven fabric. Thus, a sheet provided with polyurethane was obtained.
Next, this sheet was immersed in a 15 g / L aqueous sodium hydroxide solution heated to 90 ° C. and treated for 30 minutes to obtain a sea removal sheet from which sea components of sea-island fibers were removed. By observation with a scanning electron microscope (SEM) on the surface of the sea removal sheet, it was confirmed that the average single fiber fineness was 0.04 dtex and the fineness CV was 7.4%.

  And after half-cutting the sea removal sheet in the thickness direction, the surface opposite to the half-cut surface is brushed by grinding using a 240 mesh endless sandpaper, then dyed with a disperse dye in a circular dyeing machine, A product was obtained.

  The obtained sheet-like product was good in appearance quality and flexibility, and was a sheet-like product having a low environmental load that does not use an organic solvent in the production process. The results are shown in Table 2.

[Example 2]
A sheet-like material was obtained in the same manner as in Example 1 except that the self-emulsifying polyurethane water dispersion A was used instead of the self-emulsifying polyurethane water dispersion A.

  The obtained sheet-like product was good in appearance quality and flexibility, and was a sheet-like product having a low environmental load that does not use an organic solvent in the production process. The results are shown in Table 2.

[Example 3]
In the form of 20 parts of copolymer polyester A as a sea component and 80 parts of polyester D as an island component, 16 islands are contained in one filament, and a sea island type fiber having an average fineness of 3.8 dtex A staple (fiber length 51 mm) was used to form a web through a card and a cross wrapper, and a nonwoven fabric (2) was formed by needle punching. In the melt spinning process, the spinning operation was possible although the deposit around the mouthpiece hole during spinning and the increase in filtration pressure were slightly recognized.

  This non-woven fabric was shrunk by treating in hot water at 90 ° C. for 2 minutes and dried at 100 ° C. for 5 minutes. Next, impregnated with the self-emulsifying type polyurethane aqueous dispersion C, after heat treatment at 100 ° C. for 5 minutes, and drying with hot air at a drying temperature of 125 ° C. for 10 minutes, the polyurethane weight is 85% by weight with respect to the weight of the nonwoven fabric. The sheet | seat which gave was obtained.

  Next, this sheet was immersed in a 15 g / L aqueous sodium hydroxide solution heated to 90 ° C. and treated for 30 minutes to obtain a sea removal sheet from which sea components of sea-island fibers were removed. By observation with a scanning electron microscope (SEM) on the surface of the sea removal sheet, it was confirmed that the average single fiber fineness was 0.21 dtex and the fineness CV was 7.8%.

  And after half-cutting the sea removal sheet in the thickness direction, the surface opposite to the half-cut surface is brushed by grinding using a 240 mesh endless sandpaper, then dyed with a disperse dye in a circular dyeing machine, A product was obtained.

  The obtained sheet-like product was good in appearance quality and flexibility, and was a sheet-like product having a low environmental load that does not use an organic solvent in the production process. The results are shown in Table 2.

[ Reference Example 4]
A sheet-like material was obtained in the same manner as in Example 3 except that the self-emulsifying polyurethane water dispersion C was used instead of the self-emulsifying polyurethane water dispersion C.

The results are shown in Table 2.

[Comparative Example 1]
In the form of a sea-island type fiber in which 36 parts of the island component are contained in one filament at a ratio of 45 parts of the copolymer polyester B as the sea component and 55 parts of the polyester D as the island component, and the average fineness is 2.8 dtex. A staple (fiber length 51 mm) was used to form a web through a card and a cross wrapper, and a nonwoven fabric (3) was formed by needle punching. In the melt spinning process, deposits around the nozzle holes during spinning and an increase in filtration pressure were observed, and yarn breakage occurred frequently, resulting in poor operability.

  A sheet-like material was obtained in the same manner as in Example 1 except that this nonwoven fabric was used.

  The obtained sheet-like product had good appearance quality and flexibility, and was a sheet-like product having a low environmental load that does not use an organic solvent in the production process, but the spinning operability was poor. The results are shown in Table 2.

[Comparative Example 2]
In Comparative Example 1, the non-woven fabric (3) before imparting polyurethane was immersed in an aqueous solution of sodium hydroxide having a concentration of 15 g / L and treated for 30 minutes to produce a seawater-free nonwoven fabric from which sea components of sea-island fibers were removed. Then, after impregnating with the self-emulsifying type polyurethane water dispersion A, after heat treatment at 100 ° C. for 5 minutes, and then drying with hot air at a drying temperature of 125 ° C. for 10 minutes, the polyurethane weight is 80% by weight with respect to the island component weight of the nonwoven fabric. A sheet-like material was obtained in the same manner as in Comparative Example 1 except that a sheet provided with polyurethane was obtained.

  Although the obtained sheet-like material was a sheet-like material having a low environmental load that does not use an organic solvent in the production process, the appearance quality and flexibility were poor, and the spinning operability was poor. The results are shown in Table 2.

[Comparative Example 3]
In Comparative Example 1, the non-woven fabric (3) before imparting polyurethane was immersed in an aqueous solution of sodium hydroxide having a concentration of 15 g / L and treated for 30 minutes to produce a seawater-free nonwoven fabric from which sea components of sea-island fibers were removed. Thereafter, the sheet is impregnated with solvent-based polyurethane E, immersed in water at 40 ° C. and wet-solidified for 60 minutes to obtain a sheet provided with polyurethane so that the polyurethane weight relative to the island component weight of the nonwoven fabric is 80% by weight. Except for the above, the same treatment as in Comparative Example 1 was performed to obtain a sheet.

  The obtained sheet-like material was good in appearance quality and flexibility, but was a sheet-like material having a high environmental load using an organic solvent in the production process, and the spinning operability was inferior. The results are shown in Table 2.

[Comparative Example 4]
A sheet-like material was obtained in the same manner as in Comparative Example 1 except that the forced emulsification type polyurethane water dispersion F was used instead of the self-emulsification type polyurethane water dispersion A.

  The obtained sheet-like material is a sheet-like material that does not use an organic solvent in the production process and has a low environmental impact. The flexibility was good, but the appearance quality was poor in fiber dispersibility, and the spinning operation The property was inferior. The results are shown in Table 2.

Claims (8)

The manufacturing method of the sheet-like thing characterized by having the process of following (1)-(3) in this order.
(1) A copolymerized polyester comprising terephthalic acid and ethylene glycol as main components and containing 5 to 12 mol% of sodium 5-sulfoisophthalate with respect to the total acid component, wherein the copolymerized polyester is titanium. atom containing 0.1ppm or 100ppm or less, and the step of producing a nonwoven fabric using ultrafine fiber-generating fibers obtained by using containing no antimony atom, or 30ppm copolymerized polyester containing less at least as one component,
(2) The self-emulsifying polyurethane in the nonwoven fabric produced in (1) has a silicon atom content in the molecular structure of more than 0% by weight and less than 1% by weight based on the weight of the polyurethane. Impregnating a self-emulsifying polyurethane water dispersion to give a self-emulsifying polyurethane,
(3) A step of treating the nonwoven fabric provided with the self-emulsifying polyurethane in (2) with an alkaline aqueous solution to express ultrafine fibers. The method for producing a sheet-like product according to claim 1, wherein the ultrafine fibers are polyester ultrafine fibers. 3. The production of a sheet-like article according to claim 2, wherein the polyester-based ultrafine fiber is an ultrafine fiber containing 0.5 ppm to 150 ppm of titanium atoms and not containing antimony atoms or containing 30 ppm or less. Method. The method for producing a sheet-like material according to any one of claims 1 to 3, wherein a sea-island type composite fiber is used as the ultrafine fiber generating fiber. The method for producing a sheet-like material according to any one of claims 1 to 4, wherein the self-emulsifying polyurethane water dispersion does not contain an organic solvent or contains 1% by weight or less. The sheet-like material according to any one of claims 1 to 5 , wherein the self-emulsifying polyurethane has 3 to 30% by weight of polyethylene glycol with respect to the total weight of the polyurethane. Method. The method for producing a sheet-like product according to any one of claims 1 to 6 , wherein the self-emulsifying polyurethane has a nonionic emulsifier. A sheet-like material in which a self-emulsifying polyurethane having a crosslinked structure by a siloxane bond in a self-emulsifying polyurethane molecular structure is contained in a nonwoven fabric composed of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less. The ultrafine fiber contains 0.5 ppm or more and 150 ppm or less of titanium atoms and does not contain antimony atoms or contains 30 ppm or less, and the self-emulsifying polyurethane and the ultrafine fibers are not substantially adhered to each other. And the self-emulsifying polyurethane part has a nonporous structure.