JP2020084333A - Sheet-like article - Google Patents

Abstract

To provide a sheet-like article excellent in frictional property while having a deep color hue in a sheet-like article comprising a fiber-entangled body composed of a polyester ultrafine fiber, and an elastic polymer.SOLUTION: The sheet-like article comprises: a fiber-entangled body constituted by entangling an ultrafine fiber composed of polyester-based resin having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less; and an elastic polymer where the following requirements 1-3 are satisfied, requirement 1: the ultrafine fiber contains carbon black, requirement 2: the carbon black does not contact an interface of the ultrafine fiber, or does not expose beyond the interface, but exists only inside the ultrafine fiber, and requirement 3: the area in a part inside the carbon black nearest of the interface of the ultrafine fiber is 95% or more of an area of the ultrafine fiber. A method of manufacturing the sheet-like article is further provided.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a sheet-like material which is composed of a fiber entangled body made of polyester ultrafine fibers and a polymer elastic body and which has both dark colorability and high fastness.

A natural leather-like sheet mainly composed of a fiber entangled body made of polyester ultrafine fibers and a polymer elastic body has excellent characteristics in comparison with natural leather such as high durability and uniformity of quality, It is used not only as a material for clothing, but also in various fields such as vehicle interior materials, interiors, shoes, and clothing.When a sheet-like material is used for vehicle interior materials, etc., it is often colored in dark colors such as black. Color and high light resistance that can withstand actual use are required.

However, it is known that polyester fibers have a high refractive index and are inferior in color developability as compared with other synthetic fibers such as acetate fibers, acrylic fibers and nylon fibers, and therefore it is known that it is difficult to dye a dark color. Especially in ultrafine fibers, this tendency is remarkable due to the influence of the surface area that increases with the decrease in fiber diameter.However, when dyeing with an increase in dye concentration in order to produce a dark color, the light fastness and friction of the sheet material Since the fastness such as fastness is deteriorated, a method for achieving both dark color and fastness in a sheet material using polyester ultrafine fibers has long been required.

In order to solve the above problems, as a means for achieving both a dark color and fastness in a sheet-like material using ultrafine fibers, a method of adding a pigment such as carbon black to the ultrafine fibers, a method of using so-called primary fiber is It has been proposed (see Patent Documents 1, 2, and 3).

JP, 2004-143654, A Special table 2011-523985 gazette JP 60-224881 A

However, in the techniques disclosed in Patent Documents 1 and 2, it is possible to achieve darkening to some extent without lowering the light fastness by using a pigment that is more excellent in light fastness than a dye. .. However, the exposure of the pigment on the surface of the ultrafine fibers causes problems such as deterioration of friction characteristics such as friction fastness and contamination of a processing machine during processing.

In addition, the method disclosed in Patent Document 3 uses a core-sheath type composite fiber in which a core component that has been rawly deposited is covered with a sheath component that has not been rawly deposited, and thus contamination due to fallen substances from the fiber is prevented. Is possible. However, there is a problem in that the specific surface area of the deposited portion becomes large and the color becomes bright by applying the raw material only to the core component.

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide a sheet-like material made of a fiber entangled body made of polyester ultrafine fibers and a polymer elastic body, while having a dark color. An object is to provide a sheet-shaped material having excellent friction characteristics.

As a result of repeated studies by the present inventors in order to achieve the above object, without contacting the interface of the ultrafine fibers, or in a range where the carbon black is not exposed beyond the interface, carbon black is widely dispersed inside the ultrafine fibers. It has been found that not only is it possible to prevent the pigment from falling out of the ultrafine fibers, but it is also possible to obtain a sheet-like material having a dark color.

The present invention has been completed based on these findings, and the present invention provides the following inventions.

That is, the sheet-like material of the present invention has an average single fiber diameter of 1.0 μm or more and 10.0 μm or less, and comprises a fiber entangled body composed of ultrafine fibers made of a polyester resin, and a polymer elastic body. And, the following requirements 1 to 3 are satisfied.
Requirement 1: The ultrafine fibers include carbon black Requirement 2: The carbon black is present only inside the ultrafine fibers without coming into contact with the interface of the ultrafine fibers or being exposed beyond the interface. Requirement 3: The area of the portion inside the carbon black closest to the interface of the ultrafine fibers is 95% or more of the area of the ultrafine fibers. According to a preferred embodiment of the sheet material of the present invention, the carbon is The average particle diameter of black is 0.01 μm or more and 0.30 μm or less.

According to a preferred embodiment of the sheet material of the present invention, the coefficient of variation (CV) of the average particle diameter of the carbon black is 50% or less.

According to the present invention, it is possible to obtain a sheet-like material having both a dark color and excellent durability. In addition, it is possible to obtain a sheet-shaped material in which the detachment of the pigment from the ultrafine fibers, which has been a problem in the conventional sheet-shaped material made of ultrafine fibers to which a pigment is added, is improved. Further, the sheet-like material of the present invention has a soft touch like natural leather and a dark color, and further has excellent durability, and can be widely used from furniture, chairs and vehicle interior materials to clothing applications. However, because of its excellent light fastness, it is preferably used as a vehicle interior material.

FIG. 1 is a conceptual cross-sectional view of ultrafine fibers, illustrating and explaining the existence mode of carbon black closest to the interface of the ultrafine fibers according to the present invention.

The sheet-like material of the present invention has an average single fiber diameter of 1.0 μm or more and 10.0 μm or less, and is a sheet-like product composed of a fiber entangled body composed of ultrafine fibers made of a polyester resin and a polymer elastic body. The product satisfies the following requirements 1 to 3.
Requirement 1: the ultrafine fibers include carbon black Requirement 2: the carbon black exists only inside the ultrafine fibers without coming into contact with the interface of the ultrafine fibers or being exposed beyond the interface. 3: The area of the portion inside the carbon black closest to the surface of the ultrafine fibers is 95% or more of the area of the ultrafine fibers. The details will be described below.

[Fiber entanglement]
It is important that the ultrafine fibers constituting the fiber entangled body used in the present invention are made of a polyester resin from the viewpoint of durability, particularly mechanical strength, heat resistance and the like.

Examples of the polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, and polyethylene-1,2-. Examples thereof include bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate. Among them, polyethylene terephthalate most commonly used or a polyester copolymer mainly containing an ethylene terephthalate unit is preferably used.

As the polyester resin, a single polyester may be used, or two or more different polyesters may be used. When two or more different polyesters are used, the phase of two or more components may be used. From the viewpoint of solubility, the difference in intrinsic viscosity (IV value) of the polyesters used is preferably 0.50 or less, and more preferably 0.30 or less.

In the present invention, the intrinsic viscosity is calculated by the following method.
(1) Dissolve 0.8 g of the sample polymer in 10 mL of orthochlorophenol.
(2) At a temperature of 25° C., the relative viscosity η _r is calculated by the following formula using an Ostwald viscometer.
・Η _r =η/η ₀ =(t×d)/(t ₀ ×d ₀ )
-Intrinsic viscosity (IV value) = 0.0242 η _r +0.2634
(Where η is the viscosity of the polymer solution, η ₀ is the viscosity of orthochlorophenol, t is the drop time of the solution (seconds), d is the density of the solution (g/cm ³ ), and t ₀ is the drop of orthochlorophenol. Time (sec), d ₀ represents the density (g/cm ³ ) of orthochlorophenol, respectively.)

The cross-sectional shape of the ultrafine fiber is preferably a round cross-section from the viewpoint of processing operability, but it is a polygon such as an ellipse, a flat shape and a triangle, a fan shape and a cross shape, a hollow shape, a Y shape, a T shape, and a U shape. It is also possible to adopt a cross-sectional shape of a modified cross section such as a mold.

In addition to carbon black, in addition to carbon black, the polyester resin forming the ultrafine fibers includes inorganic particles such as titanium oxide particles, lubricants, heat stabilizers, ultraviolet absorbers, conductive agents, heat storage agents and antibacterial agents. Agents and the like can be added.

It is important that the average single fiber diameter of the ultrafine fibers is 1.0 μm or more and 10.0 μm or less. By setting the average single fiber diameter of the ultrafine fibers to 1.0 μm or more, preferably 1.5 μm or more, excellent effects can be obtained in color development after dyeing, light resistance and abrasion fastness, and stability during spinning. On the other hand, when the thickness is 10.0 μm or less, preferably 6.0 μm or less, more preferably 4.5 μm or less, a sheet-like material having a dense and soft touch and excellent surface quality can be obtained.

In the present invention, the average single fiber diameter of the ultrafine fibers means a scanning electron microscope (SEM) photograph of a cross section of a sheet-like material, and randomly selects 10 ultrafine fibers of a circular shape or an ellipse close to a circle, Is calculated and the arithmetic mean value of 10 is calculated. However, when ultrafine fibers having an irregular cross section are adopted, the cross sectional area of the single fiber is first measured, and the diameter of the single fiber is calculated by calculating the diameter when the cross section is assumed to be circular.

In order to achieve excellent dark coloration in the present invention, it is important that the polyester resin forming the ultrafine fibers contains carbon black as a pigment.

Further, in order to prevent the carbon black from falling off during actual use and in the manufacturing process, the carbon black is not contacted with the interface of the ultrafine fiber, or is not exposed beyond the interface, and the inside of the ultrafine fiber is not exposed. It is important to exist only in.

This will be described with reference to the drawings. FIG. 1 is a conceptual cross-sectional view of ultrafine fibers, illustrating and explaining the existence mode of carbon black closest to the interface of the ultrafine fibers according to the present invention. In the carbon black (2) of the present invention, as shown in FIG. 1a, all the carbon black (2) is present only inside the ultrafine fibers (1). That is, for the carbon black (2a, 2b, 2c) closest to the interface of the ultrafine fibers, the carbon black (2a, 2b, 2c) is in contact with the interface (3) of the ultrafine fibers as illustrated in FIG. 1b, or the interface (3 as illustrated in FIG. 1c. ), the carbon black (2a) closest to the interface of the ultrafine fibers exists away from the interface (3) toward the center of the ultrafine fibers (1).

From the viewpoint of excellent color development of deep color and yarn strength, the area (abbreviated as S _I ) of the portion inside the carbon black closest to the interface of the ultrafine fibers is the area of the ultrafine fibers (S _F). It is important to be 95% or more (S _I /S _F ≧0.95), and preferably 97% or more (S _I /S _F ≧0.97).

In the present invention, the ratio (S _I /S _F ) of the area (S _I ) of the portion inside the carbon black closest to the interface of the ultrafine fibers to the area (S _F ) of the ultrafine fibers is calculated by the following method. Shall be done.
(1) Osmium dyeing of ultrafine fibers.
(2) An ultrathin section having a thickness of 5 to 10 μm is produced in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fibers.
(3) The fiber cross section in the ultrathin section is observed with a transmission electron microscope (TEM) at 4000 times.
(4) using the image analysis software, measuring the area of any of the ultrafine fibers (S _F).
(5) In the ultrafine fibers whose area is measured in (4), the distance A from the fiber surface to the closest carbon black is measured, and the distance A from the outer circumference of the fiber is measured inside the fiber (the carbon black closest to the interface of the ultrafine fibers. The area (S _I ) of the inner portion) is measured.
(6) The result (S _I /S _F ) obtained by dividing the area (S _I ) obtained in (5) by the area (S _F ) obtained in (4) was measured at n=5, and the average thereof was obtained. The value is defined as the ratio of the area inside the carbon black closest to the surface (S _I /S _F ).

The carbon black used in the present invention preferably has an average particle diameter of the ultrafine fibers of 0.01 μm or more and 0.30 μm or less.

The particle size referred to here is the particle size in the state where carbon black is present in the ultrafine fibers, and is generally called the secondary particle size.

When the average particle diameter is 0.01 μm or more, more preferably 0.05 μm or more, or 0.3 μm or less, more preferably 0.25 μm or less, further preferably 0.20 μm or less, a dark color is obtained. It is excellent in color development, stability during spinning, and yarn strength.

The carbon black used in the present invention preferably has a coefficient of variation (CV) of the particle diameter in the ultrafine fibers of 50% or less.

When the coefficient of variation (CV) of the particle size is 50% or less, the distribution of the particle size becomes small, and the falling of the small particles from the surface and the spinning failure due to the significantly agglomerated particles are suppressed. The coefficient of variation of particle diameter is preferably 40% or less, more preferably 30% or less.

In the present invention, the average particle size and the coefficient of variation (CV) are calculated by the following method.
(1) Osmium dyeing of ultrafine fibers.
(2) An ultrathin section having a thickness of 5 to 10 μm is produced in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fibers.
(3) The fiber cross section in the ultrathin section is observed with a transmission electron microscope (TEM) at 4000 times.
(4) The particle size of the pigment contained in the 3 μm×3 μm visual field of the observed image is measured at 20 points.
(5) An average value (arithmetic mean) and a coefficient of variation (CV) are calculated for the measured 20 particle diameters. The coefficient of variation was calculated by the following formula.
・Coefficient of variation of particle size (%)=(standard deviation of particle size)/(arithmetic mean of particle size)×100
The proportion of carbon black contained in the polyester resin forming the ultrafine fibers is preferably in the range of 0.1% by mass to 5.0% by mass with respect to the mass of the ultrafine fibers. By setting the above ratio to 0.1% by mass or more, more preferably 0.2% by mass or more, and further preferably 0.5% by mass or more, it is possible to obtain a sheet-shaped material excellent in dark coloration. it can. On the other hand, when the content is 5.0% by mass or less, more preferably 3.0% by mass or less, and further preferably 2.0% by mass or less, a sheet-like material having high physical properties such as yarn strength can be obtained.

The sheet-shaped article of the present invention is one in which the ultrafine fibers are in the form of a fiber entangled body, and particularly preferably in the form of a non-woven fabric. By using a non-woven fabric, it is possible to obtain a uniform and elegant appearance and texture when the surface is raised.

The form of the non-woven fabric includes a long-fiber non-woven fabric mainly composed of filaments and a short-fiber non-woven fabric mainly composed of fibers of 100 mm or less. When a long-fiber nonwoven fabric is used as the fibrous base material, a sheet-like material having excellent strength can be obtained, which is preferable. On the other hand, when a short-fiber nonwoven fabric is used, it is possible to increase the number of fibers oriented in the thickness direction of the sheet-like product as compared with the case of a long-fiber nonwoven fabric, and the surface of the sheet-like product when raised is highly dense. It can have a feeling.

When using a short-fiber nonwoven fabric, the fiber length of the ultrafine fibers is preferably 25 mm or more and 90 mm or less. By setting the fiber length to 90 mm or less, more preferably 80 mm or less, and further preferably 70 mm or less, good quality and texture can be obtained. On the other hand, by setting the fiber length to 25 mm or more, more preferably 35 mm or more, and further preferably 40 mm or more, a sheet-shaped material having excellent abrasion resistance can be obtained.

The basis weight of the non-woven fabric constituting the sheet-shaped material according to the present invention is measured by "6.2 mass per unit area (ISO method)" of JIS L1913:2010 "General non-woven fabric test method", and is 50 g/m ² or more and 400 g or more. It is preferably in the range of /m ² or less. By setting the basis weight of the non-woven fabric to 50 g/m ² or more, and more preferably 80 g/m ² or more, it is possible to obtain a sheet-like material having a solid feeling and an excellent texture. On the other hand, when it is 400 g/m ² or less, and more preferably 300 g/m ² or less, a flexible sheet-like material having excellent moldability can be obtained.

In the sheet-shaped article of the present invention, it is also a preferred embodiment that a woven fabric is laminated inside or on one side of the above-mentioned non-woven fabric and entangled and integrated for the purpose of improving its strength and morphological stability.

As the type of fibers constituting the woven fabric used when the woven fabrics are entangled and integrated, filament yarns, spun yarns, mixed composite yarns of filament yarns and spun yarns, and the like can be used. When entwining a non-woven fabric with a large number of fluffs on the surface due to its structure, it becomes a drawback that the fluffs fall off and are exposed on the surface, so it is more preferable to use filaments, and multifilaments are preferably used as filaments. preferable.

The fiber diameter of the single fiber of the fibers forming the woven fabric is preferably 1 μm or more and 50 μm or less. By setting the fiber diameter of the monofilament to 50 μm or less, a sheet-like material having excellent flexibility can be obtained, and by setting the fiber diameter of the monofilament to 1 μm or more, the morphological stability of the product as the sheet-like material is improved. To do.

The total fineness of the yarns constituting the above-mentioned woven fabric is JIS L1013:2010 “Chemical fiber filament yarn test method”, “8.3 fineness”, “8.3. 1 Normal fineness b) B method (simple method) It is measured at 30 dtex or more and 170 dtex or less. By setting the fineness to 170 dtex or less, a sheet material having excellent flexibility can be obtained, and by setting the total fineness to 30 dtex or more, the morphological stability of the product as the sheet material is improved. At this time, the total fineness of the multifilaments of the warp and the weft is preferably the same.

[Polymer elastic body]
Since the polymer elastic material constituting the sheet-like material of the present invention is a binder that holds the ultrafine fibers constituting the sheet-like material, in consideration of the soft texture of the sheet-like material of the present invention, the polymer elastic material used Examples of the body include polyurethane, polyurethane, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), and acrylic resin. Above all, it is a preferred embodiment to use polyurethane as the main component. By using polyurethane, it is possible to obtain a sheet-like material having a full-feeling feel, a leather-like appearance, and physical properties capable of withstanding actual use. The term "main component" as used herein means that the mass of polyurethane is more than 50 mass% with respect to the mass of the entire elastic polymer.

When polyurethane is used in the present invention, both an organic solvent-based polyurethane used in a state of being dissolved in an organic solvent and a water-dispersed polyurethane used in a state of being dispersed in water can be used. As the polyurethane, polyurethane obtained by reacting a polymer diol, an organic diisocyanate and a chain extender is preferably used.

In addition, various additives such as carbon black and other pigments, phosphorus-based, halogen-based and inorganic-based flame retardants, phenol-based, sulfur-based and phosphorus-based oxidizing agents are added to the polymer elastic body. Inhibitors, benzotriazole-based, benzophenone-based, salicylate-based, UV absorbers such as cyanoacrylate-based and oxalic acid anilide-based, light stabilizers such as hindered amine-based and benzoate-based, hydrolysis-resistant stabilizers such as polycarbodiimide, A plasticizer, an antistatic agent, a surfactant, a coagulation regulator and a dye may be contained.

Generally, the content of the elastic polymer in the sheet-like material can be appropriately adjusted in consideration of the type of the elastic polymer to be used, the method for producing the elastic polymer, the feeling and the physical properties, In the invention, the content of the elastic polymer is preferably 10% by mass or more and 60% by mass or less with respect to the mass of the fiber entangled body. By setting the content of the polymer elastic body to 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more, it is possible to strengthen the bond between the fibers by the polymeric elastic body, It is possible to improve the abrasion resistance of the sheet material. On the other hand, by making the content of the above-mentioned polymer elastic body 60% by mass or less, more preferably 45% by mass or less, further preferably 40% by mass or less, the sheet-shaped material can be made more flexible. You can

[Sheet]
It is a preferred embodiment that the sheet-like material of the present invention has naps on the surface. The naps may be provided only on the surface of the sheet-like material, or may be provided on both surfaces. The napped form in the case of having naps on the surface has a napped length and directional flexibility to the extent that a so-called finger mark is emitted, leaving a mark when the direction of the napped is changed when tracing with a finger from the viewpoint of design effect. Preferably. More specifically, the napped length of the surface is preferably 100 μm or more, more preferably 150 μm or more. On the other hand, it is preferably 400 μm or less, and more preferably 350 μm or less. For the nap length of the surface, SEM image of the cross section of the sheet-like material is taken at a magnification of 50 with the nap of the sheet-like material standing upside down using a lint brush or the like, and the height of the napped portion (layer consisting of only ultrafine fibers) It is calculated by measuring 10 points and calculating the average value.

The sheet-shaped product of the present invention has a thickness of 0.2 mm measured by "6.1.1 A method" of "6.1 Thickness (ISO method)" of JIS L1913:2010 "General nonwoven test method". It is preferably in the range of 1.2 mm or less. By setting the thickness of the sheet-like material to 0.2 mm or more, more preferably 0.3 mm or more, and further preferably 0.4 mm or more, not only excellent workability at the time of manufacturing but also a feeling of fulfillment and texture. It will be excellent. On the other hand, by setting the thickness to 1.2 mm or less, more preferably 1.1 mm or less, and further preferably 1.0 mm or less, it is possible to obtain a flexible sheet material having excellent moldability.

The sheet-like material of the present invention has a friction fastness measured according to "9.1 Friction tester type I (clock meter) method" of JIS L0849:2013 "Test method for dyeing fastness to friction" and JIS L0843:2006 ". It is preferable that the light fastness measured by "7.2 Exposure method a) First exposure method" of "Dyeing fastness test method against xenon arc lamp light" is 4 or more, respectively. When the color fastness to rubbing and the color fastness to light are grade 4 or higher, discoloration or contamination of clothes or the like can be prevented during actual use.

Further, the sheet-like material of the present invention is JIS L1096:2010 “Method for testing fabrics of woven and knitted materials”, “8.19 Abrasion strength and friction discoloration”, “8.19.5 E method (Martindale method)”. In the abrasion resistance test measured by, the weight loss of the sheet material after the pressing load is set to 12.0 kPa and the number of times of abrasion of 20000 times is preferably 10 mg or less, more preferably 8 mg or less, It is more preferably 6 mg or less. When the weight loss is 10 mg or less, it is possible to prevent contamination due to fluff falling during actual use.

Further, it is preferable that the sheet-like material of the present invention has a dark color and the surface lightness (L ^* value) is 25 or less. The lightness of the surface refers to JIS Z8781-4:2013 "Measurement-Part 4: CIE1976L ^* a ^* " in a state in which napped hair is laid down using a lint brush or the like, with a surface having a nap of a sheet-like material as a measurement surface ^. "L ^* value" defined by "3.3 CIE1976 lightness index" of "b ^* color space". In the present invention, the L ^* value is measured 10 times using a spectrophotometer, and the arithmetic average of the measurement results is adopted as the L ^* value of the sheet.

[Method for manufacturing sheet-like material]
Next, a method for producing the sheet-shaped material of the present invention will be described.

<Process for producing ultrafine fiber-expressing fiber>
As the ultrafine fiber-expressing fibers, thermoplastic resins having different solvent solubility are used as sea parts (easy-soluble polymers) and island parts (hardly soluble polymers), and the sea parts are dissolved and removed by using a solvent or the like. The use of sea-island type composite fibers having islands as ultrafine fibers can provide appropriate voids between the islands when removing the sea, that is, between the ultrafine fibers in the fiber bundle, so that a sheet-like material It is preferable from the viewpoint of texture and surface quality. As a method for spinning ultrafine fiber-generating fibers having a sea-island composite structure, a method using a sea-island composite spinneret and a polymer inter-array body in which the sea part and the island part are mutually aligned and spun is It is preferable from the viewpoint that ultrafine fibers having a fiber fineness can be obtained.

As the island portion of the ultrafine fiber-generating fiber having the sea-island type composite structure, in order to prevent carbon black from being exposed on the surface of the island portion, two components of a core component containing carbon black and a sheath component not containing carbon black are included. Preferably.

The mass ratio of the core component to the sheath component is preferably in the range of 70:30 to 99:1 in order to achieve both the color developability of the ultrafine fibers and the coating of the carbon black with the sheath component.

As a method of containing carbon black in the island portion (or core component), a polyester resin chip obtained by previously kneading carbon black in an amount of 0.1% by mass or more and 5.0% by mass or less based on the mass of the polyester resin is used. Which is obtained by mixing carbon black with polyester resin in the range of 10% by mass or more and 40% by mass or less, and mixing the masterbatch and the chips of the polyester resin, and spinning. However, the method of mixing with a polyester-based resin chip using a masterbatch is preferable because the amount of the pigment contained in the ultrafine fibers can be appropriately adjusted.

When the master batch is mixed with polyester resin chips, the number average primary particle diameter of carbon black contained in the master batch used is 0.05 μm or more and 0.10 μm or less, and the coefficient of variation (CV) is It is preferred to use less than 30% masterbatch. By using a masterbatch having a primary particle diameter within the above range, the particle diameter (secondary particle diameter) in the ultrafine fibers can be adjusted to an appropriate range.

As the sea part of the sea-island type composite fiber, polyethylene, polypropylene, polystyrene, copolyester obtained by copolymerizing sodium sulfoisophthalic acid or polyethylene glycol, and polylactic acid can be used. From the viewpoint, polystyrene and copolyester are preferably used.

In the sheet-like material manufacturing method of the present invention, the strength of the island portion of the sea-island type composite fiber is preferably 2.5 cN/dtex or more. When the strength of the island portion is 2.5 cN/dtex or more, more preferably 2.8 cN/dtex or more, and further preferably 3.0 cN/dtex or more, the abrasion resistance of the sheet-like material can be improved.

In the present invention, the strength of the island portion of the sea-island type composite fiber is calculated by the following method.
(1) 10 sea-island type composite fibers having a length of 20 cm are bundled.
(2) The sea part is dissolved and removed from the sample of (1), and then air-dried.
(3) JIS L1013:2010 “Chemical fiber filament yarn test method”, “8.5 Tensile strength and elongation”, “8.5.1 Standard time test”, grip length 5 cm, pulling speed 5 cm/min The test is repeated 10 times under a load of 2 N (N=10), and the arithmetic average of the test results is taken as the strength of the island.

<Process of manufacturing fibrous base material>
In this step, the spun ultrafine fiber-expressing fibers are opened, and then formed into a fiber web by a cross wrapper or the like, and entangled to obtain a nonwoven fabric. As a method for entanglement of the fibrous web to obtain a nonwoven fabric, needle punching treatment, water jet punching treatment or the like can be used.

As the form of the non-woven fabric, it is possible to use either a short-fiber non-woven fabric or a long-fiber non-woven fabric as described above. It is possible to obtain a high degree of compactness on the surface of the sheet-like material when it is raised.

When a short-fiber non-woven fabric is used as the non-woven fabric, the resulting ultrafine fiber-expressing fibers are preferably crimped and then cut into a predetermined length to obtain raw cotton, which is then opened, laminated, and entangled. By doing so, a short fiber non-woven fabric is obtained. Known methods can be used for the crimping and cutting.

Further, when the sheet-like material includes a woven fabric, the obtained nonwoven fabric and the woven fabric are laminated and entangled and integrated. For the entanglement and integration of the non-woven fabric and the woven fabric, the non-woven fabric is laminated on one or both sides of the non-woven fabric, or after sandwiching the woven fabric between a plurality of non-woven fabrics, the non-woven fabric is subjected to needle punching treatment or water jet punching treatment. Textile fibers can be entangled with each other.

Apparent density of the nonwoven fabric made of microfine fiber phenotype fibers after needle punching or water jet punching is preferably 0.15 g / cm ³ or more 0.45 g / cm ³ or less. By setting the apparent density to preferably 0.15 g/cm ³ or more, the sheet-like material can have sufficient morphological stability and dimensional stability. On the other hand, by setting the apparent density to preferably 0.45 g/cm ³ or less, it is possible to maintain a sufficient space for providing the polymeric elastic body.

It is also a preferred embodiment that the non-woven fabric is subjected to heat shrinkage treatment with warm water or steam in order to improve the denseness of the fibers.

Next, the non-woven fabric may be impregnated with an aqueous solution of a water-soluble resin and dried to give the water-soluble resin. By applying the water-soluble resin to the nonwoven fabric, the fibers are fixed and the dimensional stability is improved.

<Step of expressing ultrafine fibers>
In this step, the obtained fibrous base material is treated with a solvent to express ultrafine fibers having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less.

The expression treatment of the ultrafine fibers can be performed by immersing a nonwoven fabric composed of sea-island type composite fibers in a solvent to dissolve and remove the sea part of the sea-island type composite fibers.

When the ultrafine fiber-expressing fiber is a sea-island type composite fiber, as a solvent for dissolving and removing the sea part, when the sea part is polyethylene, polypropylene or polystyrene, an organic solvent such as toluene or trichlorethylene can be used. When the sea part is a copolyester or polylactic acid, an aqueous alkali solution such as sodium hydroxide can be used. When the sea part is a water-soluble thermoplastic polyvinyl alcohol-based resin, hot water can be used.

<Step of applying a polymeric elastic body>
In this step, a solution of a polymer elastic material is impregnated into a fibrous base material containing the ultrafine fibers or the ultrafine fiber-expressing fibers as a main constituent and solidified to give the polymer elastic material. As a method for fixing the polymeric elastic body to the nonwoven fabric, there is a method of impregnating the nonwoven fabric (fiber entangled body) with a solution of the polymeric elastic body and then wet coagulation or dry coagulation. Therefore, these methods can be appropriately selected.

N,N'-dimethylformamide, dimethylsulfoxide, and the like are preferably used as the solvent used when applying polyurethane as the polymer elastic material. Alternatively, a water-dispersed polyurethane liquid in which polyurethane is dispersed as an emulsion in water may be used.

Incidentally, the application of the polymeric elastic body to the fibrous base material may be applied before the generation of the ultrafine fibers from the ultrafine fiber-generating fibers, or after the generation of the ultrafine fibers from the ultrafine fiber-generating fibers. May be.

<Process of half-cutting and polishing a sheet material>
From the viewpoint of manufacturing efficiency, it is a preferable embodiment to half-cut the sheet-like material to which the polymer elastic body is applied after the above steps.

Further, the surface of the sheet-shaped article or the semi-cut sheet-shaped article provided with the above-mentioned elastic polymer can be subjected to a nap treatment. The raising treatment can be performed by a method such as grinding using sandpaper or a roll sander. The raising treatment can be applied to only one surface of the sheet-like material or to both surfaces thereof.

When the raising treatment is applied, a lubricant such as a silicone emulsion can be applied to the surface of the sheet-like portion before the raising treatment. Further, by providing the antistatic agent before the raising process, it becomes difficult for the grinding powder generated from the sheet-like material due to the grinding to be deposited on the sandpaper. In this way, a sheet-like material is formed.

<Process of dyeing a sheet material>
The above sheet-like material is preferably dyed with a dye having the same color as the color of carbon black. This dyeing treatment includes, for example, jet dyeing treatment using a Jigger dyeing machine or jet dyeing machine, dip dyeing treatment such as thermosol dyeing treatment using a continuous dyeing machine, or roller printing, screen printing, inkjet printing, sublimation. Printing on the napped surface by printing, vacuum sublimation printing, or the like can be used. Above all, it is preferable to use a jet dyeing machine from the viewpoint of quality and quality, because a soft texture can be obtained. If necessary, various resin finishing processes can be performed after dyeing.

<Post-processing step>
Further, the surface of the above-mentioned sheet-like material can be provided with a design property, if necessary. For example, post processing such as perforation processing such as perforation, embossing processing, laser processing, pinsonic processing, and printing processing can be performed.

The sheet-like material of the present invention obtained by the above-exemplified production method has a natural leather-like soft touch and dark color, and further has excellent durability, and is used for furniture, chairs and vehicle interior materials. Although it can be widely used for clothing, it is particularly suitable for vehicle interior materials because of its excellent light fastness.

Next, the sheet-like material of the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Next, the evaluation method and its measurement conditions used in the examples will be described. However, in the measurement of each physical property, unless otherwise specified, the measurement was performed based on the above-mentioned methods.

[Measuring method and processing method for evaluation]
(1) Area of the portion inside the carbon black closest to the surface of the ultrafine fibers:
An ultrathin section in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fiber was produced using an ultramicrotome "MT6000 type" manufactured by Sorvall. The obtained slice was observed using a transmission electron microscope (“H7700 type” manufactured by Hitachi High-Technologies Corporation). Next, the area of the ultrafine fibers, the distance A from the surface to the closest carbon black, and the area of the portion inside the carbon black closest to the surface were measured using image analysis software (“WinROOF” manufactured by Mitani Corporation).

(2) Average particle size and coefficient of variation (CV) of pigment:
An ultrathin section in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fiber was produced using an ultramicrotome "MT6000 type" manufactured by Sorvall. The obtained slice was observed using a transmission electron microscope (“H7700 type” manufactured by Hitachi High-Technologies Corporation). Next, the particle size of the pigment was measured using image analysis software (“WinROOF” manufactured by Mitani Corporation).

(3) Lightness of sheet (L ^* value):
The L ^* value defined in 3.3 of JIS Z8781-4:2013 “Color measurement—Part 4: CIE1976L ^* a ^* b ^* color space” described above was measured using a spectrophotometric system. The measurement was performed 10 times by "CR-310" manufactured by Konica Minolta, and the average was taken as the L ^* value of the sheet-like material.

(4) Rubbing fastness of sheet:
The degree of contamination of the sample after the measurement was judged by a gray scale for contamination specified in JIS L0805:2005 “Gray scale for contamination”, and the color difference ΔE ^* _ab according to No. 4 or more (L ^* a ^* b ^* color system was 4. 5±0.3 or less) was passed.

(5) Light fastness of sheet:
The degree of discoloration of the sample after irradiation was graded using the gray scale for discoloration specified in JIS L0804:2004 “Grayscale for discoloration”, and color difference ΔE according to the L ^* a ^* b ^* color system was determined. ^* _Ab was 1.7±0.3 or less).

(6) Abrasion resistance of sheet material:
As a wear tester, James H. Heal & Co. The "Model 406" manufactured by "Model 406" was used as a standard friction cloth and "Abrasive CLOTH SM25" manufactured by the same company was subjected to an abrasion resistance test, and a sheet having a wear loss of 10 mg or less was passed.

<Manufacture of raw cotton A>
An ultrafine fiber-expressing fiber having a sea-island type composite structure in which a core component and a sheath component were compounded in a core-sheath type to form an island part and further a sea part was melt-spun under the following conditions.
Core component: A mixture of the following components (a) and (b) in a mass ratio of 94:6 (a) Polyethylene terephthalate A having an intrinsic viscosity (IV value) of 0.73
(B) A master containing 20% by mass of carbon black (average particle size: 0.05 μm, coefficient of variation (CV) of particle size: 20%) in the polyethylene terephthalate A relative to the mass of the masterbatch. Batch/sheath component: Polyethylene terephthalate A above
・Sea part: polystyrene with MFR of 65 g/10 min ・Cover: 3 component sea-island composite spinneret with 16 islands/hole ・Spinning temperature: 285℃
・Core component/sheath component mass ratio: 80/20
・Island/sea part mass ratio: 80/20
・Discharge rate: 1.2g/(min・hole),
-Spinning speed: 1100 m/min. Then, it was stretched 2.8 times in an oil bath for spinning at 90°C. Then, after performing crimping treatment using an indentation type crimping machine, it was cut into a length of 51 mm to obtain a raw cotton A of sea-island type composite fiber having a single fiber fineness of 3.8 dtex. The obtained raw cotton A is shown in Table 1.

<Manufacture of raw cotton B>
A sea-island type having a single fiber fineness of 3.8 dtex as in the production of raw cotton A except that carbon black having an average particle diameter of 0.10 μm and a coefficient of variation (CV) of particle diameter of 30% was used. A raw cotton B of a composite fiber was obtained. The obtained raw cotton B is shown in Table 1.

<Manufacture of raw cotton C>
A sea-island type single fiber having a fineness of 3.8 dtex was produced in the same manner as in the production of the raw cotton A except that carbon black having an average particle diameter of 0.05 μm and a coefficient of variation (CV) of particle diameter of 50% was used as the carbon black. A raw cotton C of a composite fiber was obtained. The obtained raw cotton C is shown in Table 1.

<Manufacture of raw cotton D>
A raw material D of sea-island type composite fiber having a single fiber fineness of 3.8 dtex was obtained in the same manner as in the production of raw cotton A except that the mass ratio of the components (a) and (b) was changed to 87:13. The obtained raw cotton D is shown in Table 1.

<Manufacture of raw cotton E>
A sea-island composite fiber raw cotton E having a single fiber fineness of 3.8 dtex was obtained in the same manner as in the production of raw cotton A except that the mass ratio of the core component and the sheath component was changed to 90/10. The obtained raw cotton E is shown in Table 1.

<Manufacture of raw cotton F>
A single fiber fineness of 3.8 dtex was obtained in the same manner as in the production of the raw cotton A except that the mass ratio of the components (a) and (b) was changed to 93:7 and the mass ratio of the core component and the sheath component was changed to 75/25. Raw cotton F of sea-island type composite fiber was obtained. The obtained raw cotton F is shown in Table 1.

<Manufacture of raw cotton G>
A sea-island composite fiber raw cotton G having a single fiber fineness of 3.8 dtex was obtained in the same manner as in the raw cotton A production except that polyethylene terephthalate B having an intrinsic viscosity (IV) of 0.76 was used as a sheath component. The obtained raw cotton G is shown in Table 1.

<Manufacture of raw cotton H>
A sea-island type composite fiber having a single fiber fineness of 3.8 dtex was produced in the same manner as in the production of the raw cotton A except that carbon black having an average particle diameter of 0.20 μm and a coefficient of variation of particle diameter of 50% was used as the carbon black. Raw cotton H was obtained. The obtained raw cotton H is shown in Table 1.

<Production of raw cotton I>
The single fiber fineness was 3.8 dtex in the same manner as in the production of the raw cotton A except that the mass ratio of the components (a) and (b) was changed to 90:10 and the mass ratio of the core component and the sheath component was changed to 50/50. A raw cotton I of sea-island type composite fiber was obtained. The obtained raw cotton I is shown in Table 1.

<Manufacture of raw cotton J>
A sea-island composite fiber raw cotton J having a single fiber fineness of 3.8 dtex was obtained in the same manner as in the raw cotton A production except that polyethylene terephthalate C having an intrinsic viscosity (IV) of 0.79 was used as a sheath component. The obtained raw cotton J is shown in Table 1.

<Manufacture of raw cotton K>
Ultrafine fiber-expressing fibers having a sea-island type composite structure composed of islands and seas were melt-spun under the following conditions.
Island part: A mixture of the following components (a) and (b) in a mass ratio of 95:5 (a) Polyethylene terephthalate A having an intrinsic viscosity (IV value) of 0.73
(B) A masterbatch/kaifu containing 20% by mass of carbon black (average particle size: 0.05 μm, coefficient of variation of particle size: 20%) in the polyethylene terephthalate A relative to the mass of the masterbatch. : Polystyrene with MFR of 65g/10min・Spinneret: Sea island type spinneret with 16 islands/hole ・Spinning temperature: 285℃
・Island/sea part mass ratio: 80/20
・Discharge rate: 1.2g/(min・hole),
-Spinning speed: 1100 m/min. Then, it was stretched 2.8 times in an oil bath for spinning at 90°C. Then, after crimping using a push-type crimping machine, it was cut into a length of 51 mm to obtain a raw cotton K of sea-island type composite fiber having a single fiber fineness of 3.8 dtex.

[Example 1]
<Process of manufacturing fibrous base material>
First, raw cotton A was used to form a laminated web through a card and cross-wrapper process. Then, needle punching was performed with 2500 punches/cm ² to obtain a nonwoven fabric having a basis weight of 550 g/m ² and a thickness of 2.5 mm.

<Step of expressing ultrafine fibers>
The nonwoven fabric obtained as described above was shrink-treated with hot water at 96°C. Then, a nonwoven fabric contracted with hot water was impregnated with an aqueous solution of polyvinyl alcohol (PVA) having a saponification degree of 88%, which was prepared to have a concentration of 12% by mass. Further, this was squeezed with a roll and dried while migrating PVA with hot air at a temperature of 120° C. for 10 minutes to obtain a sheet with PVA in which the PVA mass was 25 mass% with respect to the mass of the sheet substrate. The sheet with PVA thus obtained was dipped in trichlorethylene, and squeezed and compressed by mangle 10 times. Thus, the sea area was dissolved and removed, and the PVA-added sheet was subjected to a compression treatment to obtain a PVA-attached sheet in which the ultrafine fiber bundles provided with PVA were entangled.

<Step of applying a polymeric elastic body>
The PVA-attached sheet obtained as described above was dipped in a DMF (dimethylformamide) solution of polyurethane, which was prepared so that the solid content of polyurethane as a main component was 13%. After that, the sheet with deseaed PVA soaked in a DMF solution of polyurethane was squeezed with a roll. Next, this sheet was immersed in a DMF aqueous solution having a concentration of 30% by mass to solidify the polyurethane. After that, PVA and DMF were removed with hot water and dried with hot air at a temperature of 110° C. for 10 minutes. Thus, a sheet with polyurethane having a thickness of 1.8 mm and a polyurethane mass of 30% by mass relative to the mass of the fibrous base material was obtained.

<Process of half-cutting and brushing>
The sheet with polyurethane obtained as described above was half-cut to a thickness of 1/2 each. Subsequently, the surface layer portion of the half-cut surface was ground by 0.3 mm with an endless sandpaper having a sandpaper count of 180 to perform a raising process to obtain a napped sheet having a thickness of 0.6 mm.

<Dyeing and finishing process>
The napped sheet obtained as described above was dyed using a jet dyeing machine. At this time, a black dye was used at 120° C., and a resipe adjusted to have an L ^* value of 22 after dyeing was used. After that, a drying treatment was performed at 100° C. for 7 minutes to obtain a sheet-shaped material having an average single fiber diameter of the ultrafine fibers of 4.4 μm, a basis weight of 230 g/m ² , and a thickness of 0.7 mm. The obtained sheet material had excellent toughness and abrasion resistance. The results are shown in Table 2.

[Examples 2 to 8]
A sheet-like material was obtained in the same manner as in Example 1 except that the raw cottons B to H were used. The obtained sheet material had excellent toughness and abrasion resistance. The results are shown in Table 2.

[Comparative Example 1]
A sheet-like material was obtained in the same manner as in Example 1 except that the raw cotton I was used. The obtained sheet-like material had a large amount of the dye used in comparison with Example 1 and was inferior in fastness. The results are shown in Table 2.

[Comparative example 2]
A sheet-like material was obtained in the same manner as in Example 1 except that the raw cotton J was used. The obtained sheet-like material had a large amount of the dye used in comparison with Example 1 and was inferior in fastness. The results are shown in Table 2.

[Comparative Example 3]
A sheet-like material was obtained in the same manner as in Example 1 except that the raw cotton K was used. The obtained sheet-like material was inferior in friction fastness due to the drop of carbon black from the fiber surface.

As shown in Examples 1 to 8 in Table 2, when the area inside the carbon black closest to the surface of the ultrafine fibers used for the sheet-like material is 95% or more, a dark color is obtained even before dyeing, When further darkening is performed by dyeing, the amount of the dye used is small, and the obtained sheet-shaped material has excellent fastness.

On the other hand, as shown in Comparative Examples 1 and 2, when the area inside the carbon black closest to the surface of the ultrafine fibers used for the sheet-like material is smaller than 95%, the drop of carbon black from the surface of the ultrafine fibers is suppressed. However, since the color of the dark color is slightly inferior, a large amount of dye is required when further deepening the color by dyeing, resulting in inferior rubbing fastness.

Further, as shown in Comparative Example 3, when carbon black is present on the surface of the ultrafine fibers, although the dark color is comparable to that of Example 1, the carbon black on the surface of the ultrafine fibers is removed. It will be inferior in friction fastness.

1: Ultrafine fiber 2: Carbon black 2a, 2b, 2c: Carbon black closest to the interface of ultrafine fiber 3: Interface of ultrafine fiber

Claims (3)

A sheet-like material having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less and a fiber entangled body composed of ultrafine fibers made of a polyester resin, and a polymer elastic body, wherein: A sheet-like material satisfying 1 to 3.
Requirement 1: Requirement 2 wherein the ultrafine fibers include carbon black Requirement 3: The carbon black exists only inside the ultrafine fibers without coming into contact with the interface of the ultrafine fibers or being exposed beyond the interface. : The area of the portion inside the carbon black closest to the interface of the ultrafine fibers is 95% or more of the area of the ultrafine fibers. The sheet material according to claim 1, wherein the average particle diameter of the carbon black is 0.01 μm or more and 0.30 μm or less. The sheet-like material according to claim 1, wherein the coefficient of variation (CV) of the average particle diameter of the carbon black is 50% or less.

Images