JP2005194664A - Suede-like artificial leather - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suede-like artificial leather using an ultrafine fiber useful as a material in fields of clothes, vehicles, furniture and industrial materials and having excellent abrasion resistance and excellent touch feeling and quality appearance and to provide a suede-like artificial leather using ultrafine fiber and excellent in a drape property and clarity for dyeing in addition to excellent abrasion resistance and excellent touch feeling and quality appearance. <P>SOLUTION: The suede-like artificial leather is obtained by forming and integrating a substrate layer obtained by three-dimensionally interlacing ultrafine fiber having 0.1-0.50 dtex fineness with a fiber base fabric and a surface layer and rear surface layer each obtained by three-dimensionally interlacing ultrafine fibers while sandwiching the substrate layer and contains a polymer elastomer and has ≥300 g/m<SP>2</SP>basis weight, ≥0.30 g/cm<SP>3</SP>apparent density and ≤70 mm bending resistance. In the suede-like artificial leather, the thickness of the surface layer is ≥0.4 mm and the apparent density of the surface layer is higher than the apparent density (excluding density of the base fabric) of whole artificial leather. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a suede-like artificial leather excellent in wear resistance used for applications such as clothing, furniture, vehicles, and materials.

  Artificial leather is an artificial product that approximates the form and structure of natural leather, and is usually composed of ultrafine fibers called ultrafine fibers with a fineness of about 0.1 dtex made of polyester, polyamide, acrylonitrile polymers, etc. It is composed of a entangled sheet formed by entangled a nonwoven fabric or super extra fine fibers entangled with a fiber base fabric, and a polymer elastic body such as polyurethane.

  Artificial leather has surface morphology, color development, texture, etc., depending on the ultrafine fiber material used, the structure of the nonwoven fabric, the physical properties of the fiber base fabric, the entanglement means with the ultrafine fiber or base fabric, the type of polymer elastic body, the amount of impregnation, etc. Drapability, wear resistance, etc. are greatly different. In particular, when the water jet method is used as the entanglement means, the surface of the resulting nonwoven fabric or entangled sheet of ultrafine fibers becomes a homogeneous and densified surface due to the high density three-dimensional entanglement of the ultrafine fibers. The artificial leather has a smooth suede-like texture and an elegant surface with high appearance quality. The texture and appearance quality are higher than those of artificial leather using non-woven fabrics formed by other methods such as the needle punch method and airlaid method. Is also excellent.

  In particular, using a water jet method, using a superfine acrylic fiber as a superfine fiber, forming a nonwoven fabric or entangled sheet, the resulting suede-like artificial leather using the nonwoven fabric or entangled sheet has a texture, draping property, It has excellent dyeing clarity and is extremely useful as a suede-like material in the clothing field.

  However, artificial leather using ultra-fine fibers, particularly nonwoven fabrics or entangled sheets of ultra-fine acrylic fibers, has a problem that the surface is reduced in wear due to external force such as strong rubbing and eventually the base fabric is exposed. In the field of furniture, industrial materials, etc., the present situation is that they do not have sufficient wear resistance particularly required.

  There are several proposals for a suede-like artificial leather or napped sheet that is excellent in wear resistance using a nonwoven fabric or an entangled sheet formed by a water jet method (see Patent Documents 1 to 5). However, these proposals do not sacrifice texture and flexibility, or do not have satisfactory wear resistance, and do not use ultrafine acrylic fibers. There is no indication of texture, dyeing clarity and appearance quality based on the above.

Japanese Patent No. 3047951 Japanese Patent No. 3222024 JP 2001-27124 A JP 2001-8167 A JP 2001-96658 A

  An object of the present invention is to provide a suede-like artificial leather using superfine fibers having excellent wear resistance, excellent texture, and appearance quality useful as materials in the fields of clothing, vehicles, furniture, and industrial materials. Another object of the present invention is to provide a suede-like artificial leather excellent in drape and dyeing clarity in addition to excellent wear resistance, excellent texture and appearance quality using ultra-fine acrylic fibers.

The present invention relates to a substrate layer in which ultrafine fibers having a fineness of 0.1 to 0.50 dtex are three-dimensionally entangled with a fiber base fabric, and a surface layer in which the ultrafine fibers are three-dimensionally entangled with the substrate layer interposed therebetween. And an artificial leather having a basis weight of 300 g / m ² or more, an apparent density of 0.30 g / cm ³ or more, and a bending resistance of 70 mm or less. The suede-like artificial leather characterized in that the surface layer thickness of the artificial leather is 0.4 mm or more, and the apparent density of the surface layer is higher than the apparent density of the whole artificial leather (excluding the density of the base fabric). is there.

  According to the present invention, in an entangled sheet composed of superfine fibers and a fiber base fabric, the superfine fibers are three-dimensionally entangled with the base layer, the superfine fibers are three-dimensionally entangled across the base layer. The surface layer and the back layer are formed into an integrated entangled sheet, the surface layer in the entangled sheet is thickened, and the density of the entangled sheet is increased to increase the wear resistance of artificial leather using ultrafine fibers. When the water jet method is used as the entanglement means, it is possible to provide a suede-like artificial leather having excellent wear resistance, excellent texture, and appearance quality, and further, as ultrafine fibers. When acrylic fiber is used, it is possible to provide a suede-like artificial leather excellent in drape and dyeing clarity.

  The artificial leather of the present invention has a base layer formed by three-dimensional entanglement of a superfine fiber and a fiber base fabric in a entangled sheet state that does not include a polymer elastic body, and one of the superfine fibers sandwiching the base layer. It is composed of a surface layer in which three-dimensionally entangled each other and a back surface layer in which the other ultra-fine fibers are three-dimensionally entangled, and the substrate layer, the surface layer, and the back surface layer are formed, and the ultrafine fiber is formed. It is integrated by confounding. In addition, a surface layer means the layer of the surface side used as a surface when it is set as artificial leather, and a surface layer and a back surface layer are arbitrarily determined.

  Accordingly, in the artificial leather of the present invention in which a polymer elastic body is contained in an entangled sheet, the base layer is composed of a superfine fiber, a fiber base fabric, and a polymer elastic body, and the surface layer and the back surface layer are super It is a layer composed of ultrafine fibers and a polymer elastic body, and the base layer is also involved in the expression of the artificial leather texture, draping properties, flexibility, etc. In particular, the surface layer is involved in the expression of the texture. A part of the ultra-fine fibers entangled in is appearing as a fluff exhibiting a suede tone.

  In the present invention, the ultrafine fiber is a fiber having a fineness of 0.1 to 0.5 dtex. Extra fine fibers affect the wear resistance, texture and appearance of artificial leather. With ultra-fine fibers with a fineness of less than 0.1 dtex, the breaking strength is low and the desired wear resistance cannot be obtained. With fibers with a fineness of more than 0.5 dtex, the appearance quality is reduced, and Suede-like artificial leather with an excellent texture cannot be obtained.

  The ultrafine fiber may be a superfine fiber made of a polyester-based, polyamide-based polymer, or the like, but is preferably a superfine acrylic fiber made of an acrylonitrile-based polymer containing 50% by weight or more of acrylonitrile, When the ultra-fine fiber is an ultra-fine acrylic fiber, it becomes a suede-like artificial leather that is more excellent in drape and dyeing clarity. There is no restriction | limiting in particular about the manufacturing method of a super extra fine fiber, If it is a super extra fine acrylic fiber, a uniform fiber diameter and fiber length can be obtained by a direct spinning method.

  The acrylonitrile polymer used in the production of the ultrafine acrylic fiber, which is the preferred ultrafine fiber in the present invention, is acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth). (Meth) acrylic acid esters such as acrylate and hexyl (meth) acrylate, halogen salts such as vinyl chloride, vinyl bromide and vinylidene chloride, maleic acid imide, phenylmaleimide, (meth) acrylamide, styrene, α-methylsulfone Further, a copolymer with vinyl acetate or the like may be used, and among these, a copolymer with methyl acrylate and vinyl acetate is preferable from the viewpoint of improving spinnability. The specific viscosity of the acrylonitrile polymer forming the ultrafine acrylic fiber fiber is preferably 0.05 to 0.5 from the viewpoint of spin drawability.

  In the present invention, since the thickness of the fiber base fabric affects the formation state of the surface layer and the combined state of the surface layer and the base layer integrated by the entangled ultrafine fibers, the thickness is 0.4. It is preferable that it is a base fabric of -1.0 mm. If the thickness is less than 0.4 mm, the entanglement between the ultrafine fibers and the fiber base fabric is weak, the bonding force when the surface layer and the base layer are integrated is reduced, delamination is likely to occur, and the thickness is Even if it exceeds 1.0 mm, the entanglement between the ultrafine fibers becomes weak, it becomes difficult to form a surface layer having a target thickness, and the wear resistance cannot be improved.

  Examples of the fiber base fabric include woven fabrics, knitted fabrics, and nonwoven fabrics made of synthetic fibers such as acrylic fibers, nylon fibers, polyester fibers, polyethylene fibers, and rayon, and semi-synthetic fibers. In the present invention, the fiber base fabric is preferably a knitted fabric made of heat-shrinkable polyester fibers capable of shrinking by 10 to 20% by heat treatment, since the ultrafine fibers entangled with the fiber base fabric can be firmly held.

  In the present invention, examples of the polymer elastic body contained in the entangled sheet include polyurethane elastic bodies, acrylonitrile-butadiene copolymers, styrene-butadiene copolymers, synthetic rubbers such as polybutadiene and neoprene, and polyacrylates. It is done. In particular, the polyurethane elastic body is excellent in flexibility and wear resistance and is preferable as a polymer elastic body.

  Polyurethane elastic materials include polyethylene diols such as polyethylene adipate glycol and polyethylene adipate glycol, polyether glycols such as polyethylene glycol and polypropylene glycol, polyol components such as polycarbonate diol, aromatic isocyanate, alicyclic isocyanate, fatty acid It is preferable to use a water-dispersed polyurethane elastomer obtained by a forced emulsion polymerization method from an isocyanate component such as an aliphatic diisocyanate and a chain extender such as a glycol such as ethylene glycol or a diamine such as ethylenediamine.

  Furthermore, as the water-dispersed polyurethane elastic body, a polyether-based non-yellowing polyurethane elastic body, a carbonate-based non-yellowing polyurethane elastic body, and a polyester-based elastic body can be used. In addition, it is preferable to use a hindered amine-based, hindered phenol-based or hydrazine-based antioxidant, and a light stabilizer as a heat resistance improver in the water-dispersed polyurethane elastic body.

  The suede-like artificial leather of the present invention is composed of a macromolecular elastic body in each layer of a substrate layer of ultrafine fibers and a fiber base fabric, a surface layer of only ultrafine fibers, and an entangled sheet on which a back layer is formed. The polymer elastic body is contained so that the total content is 3 to 15% by weight. When the content is less than 3% by weight, the polymer elastic body adheres to the surface of the ultrafine fiber. It hardly contributes to the adhesion between the fibers, the wear resistance is lowered, and if it exceeds 15% by weight, the desired excellent texture and flexibility cannot be obtained.

In the suede-like artificial leather of the present invention, a base layer in which ultrafine fibers are three-dimensionally entangled with a fiber base fabric, and a surface layer and a back surface layer in which the ultrafine fibers are three-dimensionally entangled with the substrate layer interposed therebetween. The formed entangled sheet contains a polymer elastic body and has excellent wear resistance, which is an artificial leather having a basis weight of 300 g / m ² or more and an apparent density of 0.30 g / cm ³ or more. Necessary to obtain, if the basis weight of the whole artificial leather is less than 300 g / m ² and the apparent density is less than 0.30 g / cm ³ , the intended wear resistance cannot be obtained.

In order to obtain an artificial leather having a basis weight of 300 g / m ² or more and an apparent density of 0.30 g / cm ³ or more, a water jet method is used in which a paper sheet made of ultrafine fibers is placed on a fiber base fabric in the process of manufacturing an entangled sheet. When making an entanglement, use a paper sheet of ultra-fine fibers with different basis weights, use the one with a high basis weight first, and gradually increase the jet pressure of the water jet to place it appropriately from the same side and the opposite side A method of entanglement by applying a number of water jets according to the number is preferably used.

  The suede-like artificial leather of the present invention needs to have a bending resistance of 70 mm or less in order to obtain excellent texture as well as excellent wear resistance, which is the object of the present invention, and the bending resistance is 70 mm or less. It has a soft texture.

In the suede-like artificial leather of the present invention, the surface layer of the artificial leather has a surface layer thickness of 0.4 mm or more, which is higher than the apparent density of the whole artificial leather (excluding the density of the fiber base fabric). More preferably, an apparent density of 0.31 g / cm ³ or more is necessary to obtain excellent wear resistance, and the thickness is less than 0.4 mm. The apparent density of the whole artificial leather (fiber base fabric) If the density is lower than the above, the intended abrasion resistance cannot be obtained, and the fiber base fabric of the base layer is exposed in 20,000 wear tests in accordance with JIS L1096 (Martindale method).

  In order to manufacture the suede-like artificial leather of the present invention, for example, the following method is used. In other words, ultra-fine fibers are cut to an arbitrary length according to the purpose of use of artificial leather, and the cut ultra-fine fibers are entangled with a fiber base fabric by a water jet. Prepare a paper-making sheet with a different basis weight of ultra-fine fibers. Next, the paper sheet is placed on a fiber base cloth of a predetermined thickness, and the operation of entangling the ultrafine fibers on the fiber base cloth by applying a water jet of pressure that is sequentially increased from above the paper base sheet is repeated from both sides as many times as necessary. After the treatment and entanglement treatment, if the fiber base fabric is a base fabric made of heat-shrinkable fibers, the fiber base fabric is shrunk by heat treatment with wet heat or dry heat, and the ultrafine fibers are firmly fixed to the fiber base fabric. In addition to forming the base layer, the surface layer and the back surface layer are formed to produce an entangled sheet having a predetermined basis weight and an apparent density. In some cases, the entangled sheet is dried, brushed and dyed, impregnated with a polymer elastic body in the form of an aqueous dispersion, and dried. Further, the surface is sanded and the surface layer is ground to a predetermined thickness and finished.

  Hereinafter, the present invention will be specifically described by way of examples. In addition, the measuring method of each measured value in an Example and a comparative example is shown below.

(1) Thickness of sheet and artificial leather The thickness was measured by cross-sectional observation with a scanning electron microscope (SEM) 50 times.
(2) Weight per unit area The sample weight of the unit area was measured and converted to a basis weight (g / m ² ).
(3) Apparent density The apparent density of the artificial leather was calculated by the following formula.
Density (g / cm ³ ) = Weight (g / cm ² ) / Thickness (mm) × 1/1000
In addition, the apparent density of the surface layer in the artificial leather is determined by the amount of the surface layer removed when the wear is reduced to the base fabric exposure in a certain area (cm ² ) by the same abrasion test as that for measuring the abrasion resistance. It calculated from weight (g) and thickness (mm).
(4) Abrasion resistance Measured by JIS L1096 (Martindale method, standard wear cloth, 12 KPa). In the case of artificial leather consisting of a 3D entangled body of ultrafine fibers and fiber base fabric and a polymer elastic body, the surface layer of the ultrafine fibers and polymer elastic body on the surface of the artificial leather loses its wear due to abrasion and the like. Although the fiber base fabric is exposed, in the present invention, it was determined that the fabric base fabric that was not exposed at a predetermined number of wear (20,000 times) was excellent in wear resistance.
(5) Thickness of surface layer It measured by cross-sectional observation with a scanning electron microscope (SEM) 50 times.
(6) Bending softness Measured by JIS L1096 (45 ° cantilever method).

[Example 1]
Preparation of paper sheet:
A superfine acrylic fiber having a single fiber fineness of 0.13 dtex (fiber diameter: 3.8 μm) made of a vinyl acetate copolymer acrylonitrile-based polymer containing 93% by weight of acrylonitrile is cut into 3 mm, and then a basis weight of 20 g / m ^{2 is} obtained by a papermaking method. , And a papermaking sheet having a basis weight of 35 g / m ² was produced. In producing the papermaking sheet, 20% by weight of polyvinyl alcohol fiber was used as a binder.

Production of entangled sheet:
A knitted fabric having a thickness of 0.4 mm and a basis weight of 115 g / m ² (pear fabric, double knit jersey) made of heat-shrinkable polyethylene terephthalate filaments of 72 dtex / 36 filaments is used as the base fabric, and the above-prepared basis weight of 35 g / m is used as the base fabric. ² is placed on an 80-mesh wire mesh, and the entanglement process is performed from the paper sheet side with a water jet at a pressure of 4 MPa using a nozzle having a hole diameter of 0.125 mm. A papermaking sheet with a weight per unit area of 35 g / m ² is placed on the paper sheet, and entangled with a water jet at a pressure of 7 MPa, and then a paper sheet with a weight per unit area of 35 g / m ² is placed on the paper and a tangling process with a water jet at a pressure of 10 MPa. Thus, a sheet having a basis weight of 220 g / m ² was formed.

Next, this sheet was inverted, and a papermaking sheet having a basis weight of 20 g / m ² was placed thereon. Similarly, a tangling process by a water jet of 3 MPa was performed, and then a papermaking sheet having a basis weight of 20 g / m ² was placed. The entanglement process with a jet was performed twice to produce a sheet having a basis weight of 260 g / m ² . Next, the produced sheet was treated in boiling water for 2 minutes to shrink the base fabric by 10%, and then dried to produce an entangled sheet. The obtained entangled sheet has a surface layer and a back layer in which the ultrafine fibers are entangled three-dimensionally with a base layer in which the ultrafine fibers are three-dimensionally entangled with the base fabric, and has a basis weight of 321 g / m ² and a thickness of 1 The apparent density was .01 mm and the apparent density was 0.32 g / m ³ .

  The obtained entangled sheet is dyed blue with a cationic dye (Nissei Kasei Co., Ltd., Nichiron Blue AQN), and then an emulsion of water-dispersed polyurethane (Bayer Co., Impranil DLN (ester)) is prepared to a concentration of 5%. ), And muffled with polyurethane so that the impregnation rate was 100%. Next, a 3% aqueous solution of sodium alginate was coated on the surface through a # 100 screen, dried at 105 ° C., and then cured at 130 ° C. for 1 minute to obtain a sheet having a polyurethane content of 5% by weight. The obtained sheet was finished by sanding the surface with sandpaper (# 240) to obtain an artificial leather.

The obtained artificial leather was a suede-like artificial leather having a basis weight of 330 g / m ² , a thickness of 1.0 mm, an apparent density of 0.33 g / cm ³ , a good texture and a high appearance quality. The artificial leather has a surface layer thickness of 0.5 mm, a base layer thickness of 0.40 mm, and a back surface layer thickness of 0.1 mm. The surface layer has a basis weight of 160 g / m ² and an apparent density of the surface layer. but higher than the apparent density of 0.19 g / cm ³ of artificial leather, excluding the density of the base fabric, and as high as 0.32 g / cm ^3, stiffness by 45 ° cantilever method is 53 mm, also Martin In the Dale abrasion test (20,000 times), the base fabric was not exposed and the appearance was good.

[Comparative Example 1]
Preparation of paper sheet:
A papermaking sheet was prepared in the same manner as in Example 1 except that the same ultrafine acrylic fiber as used in Example 1 was used and the basis weight was 26 g / m ² .
Production of entangled sheet:
The above-prepared papermaking sheet with a basis weight of 26 g / m ² is placed on the base fabric of the same knitted fabric as used in Example 1, and this is placed on an 80-mesh wire mesh. Using a 125 mm nozzle, a water jet is entangled with a water jet at a pressure of 5 MPa, and similarly, a paper sheet having a basis weight of 26 g / m ² is placed thereon and a tangling process is performed with a water jet at a pressure of 5 MPa. A sheet of / m ² was formed.

Next, this sheet is reversed, and a papermaking sheet having a basis weight of 26 g / m ² is placed thereon. Similarly, a 5 MPa high-pressure jet water flow treatment is performed, and then a papermaking sheet having a basis weight of 26 g / m ² is placed, and similarly using a 5 MPa water jet. The entanglement process was performed twice to produce a sheet. The obtained sheet had a basis weight of 219 g / m ² . Next, the produced sheet was treated in boiling water for 2 minutes to shrink the base fabric by 13%, and then dried to produce an entangled sheet. The obtained entangled sheet has a surface layer and a back layer in which the ultrafine fibers are entangled three-dimensionally with a base layer in which the ultrafine fibers are three-dimensionally entangled with the base fabric, and has a basis weight of 285 g / m ² and a thickness of 1 0.1 mm, apparent density 0.26 g / m ³ .

The obtained entangled sheet was dyed with a cationic dye under the same conditions as in Example 1, and 5% by weight of polyurethane was contained in the polyurethane impregnation treatment, followed by sanding treatment to obtain an artificial leather. The obtained artificial leather had a suede appearance with a basis weight of 270 g / m ² , a thickness of 1.0 mm, and an apparent density of 0.27 g / cm ^3. The surface layer has a basis weight of 69 g / m ² , and the surface layer has an apparent density of 0.13 g / artificial leather excluding the density of the base fabric. although higher cm ^3, as low as 0.23 g / cm ^3, a 48mm is stiffness by 45 ° cantilever method, in Martindale abrasion test (20,000 times), the exposure of the base fabric abrasion loss of the surface layer occurs confirmed.

  The suede-like artificial leather of the present invention has excellent abrasion resistance that the base fabric is not exposed even after 20000 abrasion tests in JIS L1096 (Martindale method), and is therefore used as a material for clothing. It can withstand practical use as furniture, vehicles and industrial materials and can be used as materials for furniture, vehicles and industrial materials. Further, the suede-like artificial leather of the present invention not only has excellent wear resistance, but also has a very fine suede-like soft texture and appearance quality, and when using ultra-fine acrylic fibers as ultra-fine fibers, Since it has excellent drape and dyeing clarity, it is useful as a high-quality artificial leather.

Claims (5)

A substrate layer in which ultrafine fibers having a fineness of 0.1 to 0.50 dtex are three-dimensionally entangled with a fiber base fabric, and a surface layer and a back layer in which the ultrafine fibers are three-dimensionally entangled across the substrate layer An artificial leather having a basis weight of 300 g / m ² or more, an apparent density of 0.30 g / cm ³ or more, and a bending resistance of 70 mm or less formed and integrated and containing a polymer elastic body, A suede-like artificial leather, wherein the surface layer has a thickness of 0.4 mm or more, and the apparent density of the surface layer is higher than the apparent density of the whole artificial leather (excluding the density of the base fabric).   The suede-like artificial leather according to claim 1, wherein the ultrafine fiber is an ultrafine acrylic fiber made of an acrylonitrile-based polymer containing 50% by weight or more of acrylonitrile.   The suede-like artificial leather according to claim 1 or 2, wherein the fiber base fabric is a base fabric having a thickness of 0.4 to 1.0 mm.   The suede-like artificial leather according to claim 3, wherein the fiber base fabric is a knitted fabric made of heat-shrinkable polyester fibers. The suede-like artificial leather according to any one of claims 1 to 4, wherein the polymer elastic body is contained in an amount of 3 to 15% by weight.