JP4867398B2 - Manufacturing method of sheet-like material - Google Patents

Description

  The present invention relates to a method for producing a sheet-like material excellent in appearance, texture and physical properties using a polyurethane water dispersion.

  A sheet-like material mainly composed of ultrafine fibers and polyurethane has excellent characteristics not found in natural leather, and is widely used in various applications. In particular, sheet-like materials using polyester-based ultrafine fibers are excellent in light resistance, and their use has spread year by year for clothing, chair upholstery, automotive interior materials, and the like.

  In producing such a sheet-like material, the nonwoven fabric is impregnated with an organic solvent solution of polyurethane, and then the fiber sheet-like material is immersed in water or an organic solvent solution which is a non-solvent of polyurethane to wet-solidify the polyurethane. The method is generally adopted. As such an organic solvent, a water-miscible organic solvent such as N, N'-dimethylformamide is used.

  However, since organic solvents such as N, N′-dimethylformamide used in polyurethane as described above are highly harmful to the human body and the environment, the conventional organic solvents have recently been used in the production of sheet-like materials. A method of using a polyurethane aqueous dispersion in which polyurethane is dispersed in water instead of a type of polyurethane has been studied.

  Unlike the conventional solution in which polyurethane is dissolved in an organic solvent, the polyurethane aqueous dispersion is an emulsion in which polyurethane is dispersed in water and does not contain an organic solvent.

  However, when a sheet-like material is produced using an aqueous polyurethane dispersion, the sheet is impregnated with the aqueous polyurethane dispersion and dried, but the polyurethane moves to the surface as the water evaporates during drying. Since the phenomenon occurs, it is difficult to obtain a sheet-like material that can withstand practical use because polyurethane is localized on the surface of the sheet and the quality and texture are lowered.

  In order to solve this problem and obtain a sheet material having a flexible texture, means for preventing the migration phenomenon have been studied.

  For example, in Patent Document 1, heat-sensitive gelling properties are imparted by adding inorganic salts to a polyurethane water dispersion. Due to the heat-sensitive gelation property, the polyurethane gels before being transferred to the sheet surface during drying to suppress migration and soften the texture. However, this method has a problem in productivity because there is concern about the stability of the polyurethane aqueous dispersion.

  Another method for obtaining a sheet material having a soft texture is a method of extracting a sea component of an ultrafine fiber generating fiber using an organic solvent after impregnating an organic solvent type polyurethane into a nonwoven fabric made of the ultra fine fiber generating fiber. It has been known. The sheet obtained by using this method has a very soft texture because the ultrafine fibers and polyurethane are not bonded. However, polyurethane in the polyurethane water dispersion is less entangled between polyurethane molecules than polyurethane dissolved in organic solvent, so it is easy to drop off in the process of expressing the ultrafine fibers of the ultrafine fiber-generating fiber in the organic solvent, The obtained sheet has low physical properties.

  In order to solve this problem, studies have been made to suppress the dropping of polyurethane.

  For example, in Patent Document 2, the resistance to organic solvents is improved by defining the composition of polyurethane, but the polyol uses polyether, polytetramethylene glycol, and photodegradation is unavoidable, and is actually used. Anxiety remains.

  Patent Document 3 describes a method of reacting trifunctional glycol, trifunctional amine or the like in order to improve solvent resistance. However, although this method improves the solvent resistance, the polyurethane itself is hardened, and the texture of the obtained sheet is also hardened.

  Moreover, in this invention, although the polyurethane water dispersion which has heat-sensitive gelling property is used, since surfactant is used in order to provide heat-sensitive gelling property to polyurethane, the stickiness by the bleeding of surfactant is not caused. It is easy to generate | occur | produce, Therefore There exists a subject which requires a washing | cleaning process after a polyurethane impregnation.

That is, the present condition is that the method of obtaining the sheet-like thing excellent in the external appearance, the texture, and the physical property using the polyurethane water dispersion liquid is not obtained until now.
JP-A-6-316877 JP-A-9-132976 JP 2001-81676 A

  In view of the background of such prior art, the present invention provides a method for producing a sheet-like material excellent in appearance, texture and physical properties using a polyurethane water dispersion containing no organic solvent.

In order to solve the above problems, the present invention mainly has the following configuration.
It is a manufacturing method of the sheet-like thing characterized by passing through the process of following (1)-(3) in this order.
(1) The process of creating a nonwoven fabric using the ultra fine fiber generation type | mold fiber which consists of 2 or more types of polymeric substances from which the solubility with respect to an organic solvent differs.
(2) A step of impregnating a non-woven fabric with a self-emulsifying polyurethane aqueous dispersion having a crosslinked structure of siloxane bonds in the molecular structure at a concentration of 15 wt% or more and 45 wt% or less to give the self-emulsifying polyurethane. And a step in which the content of silicon atoms due to siloxane bonds in the imparted self-emulsifying polyurethane molecular structure is more than 0% by weight and 0.8% by weight or less based on the weight of the polyurethane .
(3) A step of treating the non-woven fabric with an organic solvent to express ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the sheet-like material excellent in the external appearance, the texture, and the physical property can be obtained using the polyurethane water dispersion which does not contain an organic solvent.

The method for producing a sheet-like product according to the present invention is a method for producing a sheet-like product, wherein the following steps (1) to (3) are performed in this order.
(1) The process of creating a nonwoven fabric using the ultra fine fiber generation type | mold fiber which consists of 2 or more types of polymeric substances from which the solubility with respect to an organic solvent differs.
(2) A step of impregnating a non-woven fabric with a self-emulsifying polyurethane aqueous dispersion having a crosslinked structure of siloxane bonds in the molecular structure at a concentration of 15 wt% or more and 45 wt% or less to give the self-emulsifying polyurethane. And a step in which the content of silicon atoms due to siloxane bonds in the imparted self-emulsifying polyurethane molecular structure is more than 0% by weight and 0.8% by weight or less based on the weight of the polyurethane .
(3) A step of treating the non-woven fabric with an organic solvent to express ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less.

  By carrying out the steps (1) to (3) in this order, the self-emulsifying polyurethane and the ultrafine fiber form a structure that is not substantially bonded, and the self-emulsifying polyurethane restrains the movement of the fiber entanglement point of the ultrafine fiber. Therefore, a very flexible sheet can be obtained.

  The term “substantially not bonded” as used herein means that there is a gap between the self-emulsifying polyurethane and the ultrafine fiber when a scanning electron microscope (SEM) photograph of the cross section of the sheet-like material is observed at a magnification of 3000 times. It means that it can be confirmed. Alternatively, the self-emulsifying type polyurethane and the ultrafine fiber may have a part in contact with each other, but a scanning electron microscope (SEM) photograph of a cross section of the sheet-like material was randomly observed at a magnification of 3000 times at 10 or more locations. In that case, it means that it can be confirmed that voids exist between the self-emulsifying polyurethane and the ultrafine fibers in more than half of the parts.

  First, step (1) will be described.

  In the present invention, it is important to use ultrafine fiber-generating fibers composed of two or more types of polymer substances having different solubility in organic solvents as the ultrafine fibers constituting the nonwoven fabric. By entangling the ultrafine fiber generating fiber in advance and then treating with an organic solvent to make the fiber ultrafine, a sheet-like product formed by entanglement of the ultrafine fiber can be obtained.

  As ultra-fine fiber generation type fiber, two islands of thermoplastic resin with different solubility in organic solvents are used as sea components and island components, and the island components are converted into ultra-fine fibers by dissolving and removing the sea components using an organic solvent. Adopting a type composite fiber or a release type composite fiber in which the two-component thermoplastic resins are alternately arranged in a radial or multi-layered cross section, and split into ultrafine fibers by peeling and dividing by organic solvent treatment Can do. 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.

  Island components of sea-island type composite fibers, that is, as ultrafine fibers constituting the nonwoven fabric in the production method of the present invention, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, Various synthetic fibers such as polyamide such as 6-nylon and 66-nylon, acrylic, polyethylene, and polypropylene can be used. Of these, polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate are preferably used from the viewpoints of strength, dimensional stability, light resistance, and dyeability.

  The nonwoven fabric may be configured by mixing ultrafine fibers of different materials, and a woven fabric or a knitted fabric may be inserted into the nonwoven fabric for the purpose of improving the strength.

  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 of the nonwoven fabric and napped quality. Preferably it is 0.3 dtex or less, More preferably, it is 0.2 dtex or less. On the other hand, it is preferably 0.005 dtex or more, more preferably 0.01 dtex or more, from the viewpoint of dispersibility of fibers during raising process such as coloring after dyeing or grinding with sandpaper, and ease of spreading. .

  In addition, the average single fiber fineness of the ultrafine fibers constituting the nonwoven fabric was obtained by taking a scanning electron microscope (SEM) photograph of the surface of the sheet-like material (or nonwoven fabric) at a magnification of 2000 times to obtain a circular or nearly elliptical fiber. It is calculated by selecting 100 at random, measuring the fiber diameter, converting the specific gravity of the material polymer to fineness, and calculating the average value.

  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 is graceful, and the dyeing can be uniform and good.

  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. In addition, the fineness CV in the case of an irregular cross section is calculated based on the outer circumference circle of the irregular cross section.

  The obtained ultrafine fiber-generating fiber is preferably crimped and cut into a predetermined length to obtain a nonwoven raw cotton. Although it is good also as a long fiber nonwoven fabric without cutting to predetermined length, when attaching importance to a texture and quality, it is more preferable to cut to predetermined length and to make a short fiber nonwoven fabric. Similarly, when emphasis is placed on the texture and quality, the fiber length of the short fibers is preferably 25 mm or more and 90 mm or less in consideration of wear resistance due to entanglement.

  A known method can be used for crimping or cutting. The obtained raw cotton is made into a web with a cross wrapper or the like, and then the fibers are entangled to make a nonwoven fabric.

  Known methods such as needle punching and water jet punching can be used as a method of entangled fibers to obtain a nonwoven fabric.

  The obtained non-woven fabric may be subjected to shrinkage treatment by warm water or steam treatment in order to improve the fineness of the fibers.

  Next, process (2) is demonstrated.

  In the step (2) in the present invention, the nonwoven fabric obtained in the step (1) is impregnated with a self-emulsifying polyurethane aqueous dispersion having a silanol group inside the molecular structure of the polyurethane, and the nonwoven fabric is provided with the self-emulsifying polyurethane.

  The self-emulsifying polyurethane water dispersion is a polyurethane water dispersion that is stably dispersed in water without using an emulsifier such as a surfactant, and is hydrophilic in the self-emulsifying polyurethane molecular structure. It has an internal emulsifier.

  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.

  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 is sticky due to the emulsifier, so a washing 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 internal emulsifier may be any of a cationic system such as a quaternary amine salt, a nonionic system such as polyethylene glycol, or an anionic system such as a sulfonate or carboxylate. However, the cationic internal emulsifier is resistant to light such as yellowing. Since it is inferior, it is preferable that they are nonionic or anionic.
Examples of the neutralizing agent for the anionic internal emulsifier include tertiary amines such as ammonia, triethylamine, triethanolamine, triisopropanolamine, trimethylamine, dimethylethanolamine, sodium hydroxide, potassium hydroxide, calcium hydroxide, and the like. Examples include alkali metal or alkaline earth metal hydroxides. These are used alone or as a mixture of two or more.

  As the self-emulsifying polyurethane used in the present invention, those having a structure obtained by appropriately reacting polyol, polyisocyanate, chain extender, and internal crosslinking agent 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, 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 internal cross-linking agent is a compound having a functional group capable of cross-linking that is introduced into the molecular structure in advance when a self-emulsifying polyurethane is synthesized as a part of the self-emulsifying polyurethane molecule. , A compound used to introduce a silanol group into a self-emulsifying polyurethane molecular structure. By introducing a silanol group into the molecular structure of the self-emulsifying polyurethane, the self-emulsifying polyurethane existing in the inner space of the nonwoven fabric has a cross-linked structure by siloxane bonds. Durability can be dramatically improved.

A compound used for introducing a silanol group into a self-emulsifying polyurethane molecular structure is 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.
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 viewpoint of 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-aminopropyltrimethoxysilane .gamma.-aminopropyltriethoxysilane, .gamma.-aminopropyl dimethoxysilane, .gamma.-aminopropyl diethoxy silane and the like. 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 due to a siloxane bond in the state of being present in the interior space of the nonwoven fabric.

  The content of silicon atoms resulting from the siloxane bond is preferably more than 0% by weight and 0.8% by weight or less based on the polyurethane weight. As the number of cross-linked structures due to siloxane bonds increases, the durability of the self-emulsifying polyurethane, such as hydrolysis resistance, improves. However, when the amount is too large, the flexibility of the self-emulsifying polyurethane decreases.

  Note that the content of silicon atoms due to siloxane bonds can be calculated by comparing the area of the peak due to the siloxane bond and the peak due to the urethane bond of the polyurethane in the measurement of polyurethane by NMR.

  In the present invention, the self-emulsifying polyurethane may be used alone or in combination of two or more, and other polymers may be used in combination.

  Examples of other polymers include water-dispersible and water-soluble polymers such as acrylic and silicone.

  The softening point of the self-emulsifying polyurethane is preferably 100 ° C or higher and 250 ° C or lower. Since the softening point of polyurethane can be controlled by adjusting the combination of polyol and isocyanate, the amount of crosslinking, etc., when preparing polyurethane, the softening point is adjusted to 100 ° C. by adjusting the combination of polyol and isocyanate and the amount of crosslinking. The temperature may be in the range of 250 ° C. or lower. When the softening point is within this range, it is possible to suppress the dropping of the self-emulsifying polyurethane in the dyeing step, and it is possible to obtain a sheet-like material with a sense of fulfillment while being flexible.

  The softening point is measured by the following method. That is, a 100 μm-thick film obtained by drying a self-emulsifying polyurethane aqueous dispersion at 50 ° C. is cut into 1 cm × 5 cm (width × length), suspended in a dryer, and a 10 g weight under the film Heating at 5 ° C./min with the attached, the temperature when the weight is lowered 3 cm from the start position is defined as the softening point.

  The self-emulsifying polyurethane preferably has a weight reduction rate of 0% by weight or more and 3% by weight or less after treatment at 20 ° C. for 1 hour in an organic solvent. Since the sheet-like material of the present invention is obtained by the above-described production method, it is preferable that the weight loss of the self-emulsifying polyurethane due to dissolution and dropping in an organic solvent is smaller. Therefore, the weight reduction rate is more preferably 0% by weight or more. 2% by weight or less.

  The weight reduction rate in the organic solvent treatment was calculated as follows. By impregnating the polyurethane aqueous dispersion into a 10 cm vertical by 10 cm wide non-woven fabric made of cellulose and drying at 120 ° C. for 30 minutes, a sheet to which 75% by weight of polyurethane has been added to the non-woven fabric weight is obtained. Next, the obtained sheet was immersed in an organic solvent, the weight after treatment at 20 ° C. for 1 hour was measured, and the weight reduction rate was calculated in comparison with the weight before the immersion treatment.

  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 methods for drying by heating, and combinations 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 concentration of the self-emulsifying polyurethane aqueous dispersion (the content of the self-emulsifying polyurethane relative to the self-emulsifying polyurethane aqueous dispersion) is determined by the storage stability of the self-emulsifying polyurethane aqueous dispersion and the non-woven fabric impregnated and dried. From the viewpoint of suppressing the migration phenomenon, it is important that the content is 15% by weight or more and 45% by weight or less.

  The self-emulsifying polyurethane aqueous dispersion used in the present invention may contain a water-soluble organic solvent in an amount of 0 to 40% by weight with respect to the aqueous dispersion in order to improve storage stability and film forming property. Although there is a possibility that the organic solvent may remain in the self-emulsifying polyurethane during coagulation and there is a concern that the organic solvent may remain until the final product, it is preferably 1% by weight or less, more preferably the organic solvent. Is not contained.

  When applying a self-emulsifying polyurethane aqueous dispersion, pigments such as carbon black, dyes, fungicides, light-proofing agents such as antioxidants and UV absorbers, flame retardants, penetrants and lubricants, silica Anti-blocking agents such as titanium oxide, surfactants such as antistatic agents, antifoaming agents such as silicone, fillers such as cellulose, coagulation regulators, and the like can be used.

  In the sheet-like material obtained by the production method of the present invention, the content of the self-emulsifying polyurethane with respect to the island components of the nonwoven fabric 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 dropping 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.

  Next, process (3) is demonstrated.

  In the step (3) in the present invention, the non-woven fabric provided with the self-emulsifying polyurethane in the step (2) is treated with an organic solvent to develop ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less. When the ultrafine fiber generating fiber is a sea-island type composite fiber, polyethylene, polypropylene, polystyrene, sodium sulfoisophthalic acid, or the like can be used as the sea component.

  As the solvent for dissolving the sea component, an organic solvent such as toluene or trichloroethylene can be used, and a halogen-based organic solvent having particularly high solubility is preferable. The sea component can be removed by immersing the sea-island composite fiber in a solvent and performing a stenosis.

  In the present invention, the sheet-like material obtained through the steps (1) to (3) may be a nap-like sheet-like material having naps of ultrafine fibers on at least one side.

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.

  In addition, the sheet-like material may be obtained by half cutting or dividing into several sheets in the sheet thickness direction before performing the raising treatment.

  The sheet-like material obtained by the production method of the present invention may be dyed. 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 known 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 dye is not particularly limited and may be selected according to the ultrafine fiber constituting the nonwoven fabric. For example, a dye such as a disperse dye is used for a polyester ultrafine fiber, and an acid dye or a metal-containing dye is used for a polyamide ultrafine fiber. Can do.

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. Further, a finishing agent treatment such as a softening agent such as silicone or an antistatic agent may be applied, and the finishing treatment may be performed after dyeing or in the same bath as dyeing.

  The sheet-like material obtained by the production method of the present invention is an interior material having a very elegant appearance as a skin material for furniture, chairs, wall materials, seats, ceilings, interiors, etc. in vehicle interiors of automobiles, trains, airplanes, etc. , Shirts, jackets, bags, belts, wallets, etc., and clothing materials used for some of them, casual shoes, sports shoes, men's shoes, shoes for women's shoes, trim, etc. .

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

[Evaluation methods]
(1) Average single fiber fineness A scanning electron microscope (SEM) photograph of the surface of a non-woven fabric or sheet-like material was taken at a magnification of 2000 times, and 100 fibers having a circular shape or a nearly elliptic shape were randomly selected, and the fiber diameter was selected. It was calculated by measuring the specific gravity of the fiber polymer (polyethylene terephthalate is 1.18 g / cm ³ , 6-nylon is 1.14 g / cm ³ ) and calculating the average value of 100 fibers. .

(2) 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.

(3) Confirmation of siloxane bond In the NMR measurement of polyurethane, the area of the peak due to the siloxane bond and the peak due to the urethane bond of the polyurethane are compared to determine the presence or absence of a siloxane bond and the inclusion of silicon atoms due to the siloxane bond. The amount was calculated.

(4) Softening point of polyurethane A polyurethane water dispersion is dried at 50 ° C. for 60 minutes and then heat treated at 120 ° C. for 5 minutes, and a 100 μm thick film is cut into 1 cm × 5 cm (width × length) and dried. Suspended in the cabin. Heating was performed at 5 ° C./min with a 10 g weight attached to the lower part of the film, and the temperature when the weight position dropped 3 cm from the start position was defined as the softening point.

(5) Solvent resistance of polyurethane A sheet provided with 75% by weight of polyurethane with respect to the weight of the nonwoven fabric by impregnating a polyurethane aqueous dispersion with a 10 cm x 10 cm width cellulose nonwoven fabric and drying at 120 ° C for 30 minutes. obtain. Next, the obtained sheet was immersed in trichlorethylene, the weight after treatment at 20 ° C. for 1 hour was measured, and the weight reduction rate was calculated in comparison with the weight before the immersion treatment.

(6) Appearance quality The surface quality of the sheet was evaluated by visual inspection and sensory evaluation as follows. A good level of the present invention was “◯”.
○: 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.

(7) Pilling Evaluation Piling evaluation of the sheet-like material was performed by James H. as a Martindale abrasion tester. Heal & Co. The model 406 made by using the company's ABRASIVE CLOTH SM25 as a standard friction cloth, a load equivalent to 12 kPa was applied, and the appearance of the sample after being rubbed under conditions of 20,000 wear times was visually observed and evaluated. . The evaluation criteria were grade 5 when the appearance of the sample was not changed from before friction, grade 1 when the appearance of many hairballs was graded, and the grade was divided by 0.5 grade. Moreover, the pass level in this invention was made into the 4th grade or more.

(8) Texture Twelve healthy adult males and 10 adult females were evaluated with a total of 20 evaluators, and the following evaluation was made by tactile sensation. A good level of the present invention was “◯”.
○: Very flexible and moderate rebound.
(Triangle | delta): Although it is flexible, there is no rebound feeling.
X: Hard.

[Notation of chemical substances]
The meanings of the abbreviations of chemical substances used in each example and comparative example are as follows.
C5C6PC: Copolycarbonate of pentamethylene carbonate diol and hexamethylene carbonate diol 3MPC: Poly (3-methylpentane carbonate)
PHC: polyhexamethylene carbonate PTMG: polytetramethylene glycol H12MDI: dicyclohexylmethane diisocyanate HDI: hexamethylene diisocyanate TDI: tolylene diisocyanate PET: polyethylene terephthalate Ny6: 6-nylon [polyurethane species]
The composition of the polyurethane water dispersion used in Examples and Comparative Examples is as follows.

(1) Self-emulsifying polyurethane water dispersion I (PUI)
A. Polyurethane composition Polyisocyanate: H12MDI
Polyol: C5C6PC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Water (diamine obtained by reaction of isocyanate and water)
Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane Si content: 0.4%
C. Softening point: 220 ° C
D. Solvent resistance: 0.5%.

(2) Self-emulsifying polyurethane water dispersion II (PUII)
A. Polyurethane composition Polyisocyanate: HDI
Polyol: 3MPC
Internal emulsifier: dimethylolpropionic acid triethylamine salt Chain extender: water (diamine obtained by reaction of isocyanate and water)
Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane Si content: 0.2%
C. Softening point: 200 ° C
D. Solvent resistance: 1%.

(3) Self-emulsifying polyurethane water dispersion III (PUIII)
A. Polyurethane composition Polyisocyanate: HDI
Polyol: C5C6PC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Water (diamine obtained by reaction of isocyanate and water)
Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane Si content: 0.2%
C. Softening point: 210 ° C
D. Solvent resistance: 3%.

(4) Self-emulsifying polyurethane water dispersion IV (PUIV)
A. Polyurethane composition Polyisocyanate: HDI
Polyol: 3MPC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Water (diamine obtained by reaction of isocyanate and water)
Internal cross-linking agent: none Si content: 0%
C. Softening point: 85 ° C
D. Solvent resistance: 45%.

(5) Forced emulsification type polyurethane water dispersion V (PUV)
A. Polyurethane composition Polyisocyanate: TDI
Polyol: PHC, PTMG
Internal emulsifier: dimethylolpropionic acid triethylamine salt Chain extender: diethylenetriamine, isophoronediamine Internal crosslinking agent: None Si content: 0%
C. Softening point: 180 ° C
D. Solvent resistance: 4%.

[Example 1]
A sea island with a composite fineness of 3.8d using a sea island-type composite base with 16 islands using polystyrene as the sea ingredient, polyethylene terephthalate as the island ingredient, and a composite ratio of 57% sea ingredient and 43% island ingredient. After spinning the mold composite fiber, it was stretched, crimped, and cut into 51 mm to obtain a raw nonwoven fabric. The obtained raw cotton was made into a web using a cross wrapper and made into a nonwoven fabric having a basis weight of 530 g / m ² by needle punching.

  This nonwoven fabric was treated in 90 ° C. hot water for 2 minutes to shrink and dried at 100 ° C. for 5 minutes. Next, the self-emulsifying type polyurethane water dispersion I (PUI) is impregnated at a solid content concentration of 30% by weight and dried with hot air at a drying temperature of 125 ° C. for 10 minutes. Thus, a sheet to which polyurethane was applied was obtained.

  Thereafter, polystyrene as a sea component was extracted and removed from trichlorethylene and dried to obtain a sea removal sheet. 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 had good appearance quality, pilling evaluation, and texture.

[Example 2]
A sheet-like material having a polyurethane weight of 60% by weight with respect to the island component weight of the nonwoven fabric, except that the self-emulsifying type polyurethane aqueous dispersion II (PUII) was impregnated at a solid concentration of 20% by weight. Got. The obtained sheet-like product had good appearance quality, pilling evaluation, and texture.

[Example 3]
The same treatment as in Example 1 was performed except that Ny6 was used for the island component and the self-emulsifying polyurethane aqueous dispersion III (PUIII) was impregnated at a solid concentration of 40% by weight. A 100% by weight sheet was obtained. The average single fiber fineness was 0.05 dtex, and the fineness CV was 7.5%. The obtained sheet-like product had good appearance quality, pilling evaluation, and texture.

[Example 4]
Except that the sea component was polyethylene and extracted and removed in toluene, the same treatment as in Example 1 was performed to obtain a sheet-like material having a polyurethane weight of 80% by weight relative to the island component weight of the nonwoven fabric. The obtained sheet-like product had good appearance quality, pilling evaluation, and texture.

[Comparative Example 1]
A sheet-like material having a polyurethane weight of 80% by weight with respect to the weight of the island component of the nonwoven fabric, except that the self-emulsifying polyurethane aqueous dispersion IV (PUIV) was impregnated at a solid content concentration of 30% by weight. Got. Although the obtained sheet-like material had a good texture, the appearance quality was long and raised and became a blanket, and the pilling evaluation was first grade.

[Comparative Example 2]
In Example 1, a seawater-free nonwoven fabric obtained by removing the sea components of sea-island fibers in trichlorethylene was prepared from the nonwoven fabric before applying polyurethane, and then a self-emulsifying polyurethane water dispersion I (PUI) was added at a solid content concentration of 30. The same as in Example 1 except that a sheet provided with polyurethane was obtained by impregnating with weight% and drying with hot air at a drying temperature of 125 ° C. for 10 minutes so that the polyurethane weight relative to the island component weight of the nonwoven fabric was 85% by weight. The process was performed to obtain a sheet.
The pilling evaluation of the obtained sheet-like material was 4.5 grade, but it had a very hard texture and was poor in appearance quality with almost no napping.

[Comparative Example 3]
A sheet-like material having a polyurethane weight of 15% by weight with respect to the island component weight of the nonwoven fabric, except that the self-emulsifying type polyurethane aqueous dispersion I (PUI) was impregnated at a solid concentration of 10% by weight. Got. Although the obtained sheet-like material had a good texture, the appearance quality was rough and poor, and the pilling evaluation was first grade.

[Comparative Example 4]
Except impregnated with the forced emulsification type polyurethane water dispersion I (PUV) at a solid content concentration of 30% by weight, the same treatment as in Example 1 was performed, and the sheet-like material having a polyurethane weight of 75% by weight with respect to the island component weight of the nonwoven fabric Got. Although the obtained sheet-like material had a pilling evaluation of 4.5 grade, the texture was hard and the appearance quality was almost free from napping.

Claims (3)

The manufacturing method of the sheet-like thing characterized by passing through the process of following (1)-(3) in this order.
(1) The process of creating a nonwoven fabric using the ultra fine fiber generation type | mold fiber which consists of 2 or more types of polymeric substances from which the solubility with respect to an organic solvent differs.
(2) A step of impregnating and solidifying a non-woven fabric with a self-emulsifying polyurethane aqueous dispersion having a silanol group in the molecular structure at a concentration of 15% by weight to 45% by weight to give the self-emulsifying polyurethane. The process in which the content of silicon atoms resulting from siloxane bonds in the imparted self-emulsifying polyurethane molecular structure is more than 0% by weight and 0.8% by weight or less based on the weight of polyurethane .
(3) A step of treating the non-woven fabric with an organic solvent to express ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less. The method for producing a sheet-like material according to claim 1, wherein the amount of the organic solvent contained in the self-emulsifying polyurethane water dispersion is 1% by weight or less based on the weight of the polyurethane water dispersion. The method for producing a sheet-like product according to claim 1 or 2, wherein the ultrafine fiber generating fiber is a sea-island type composite fiber.