JP2016011477A - Substrate for artificial leather and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for an artificial leather composed of a fiber and an elastomer that does not have uneven color between the fiber and the elastomer upon dyeing the substrate for the artificial leather, and that has a good wear characteristics and an excellent surface quality, as well as to provide a method for producing the substrate.SOLUTION: The substrate for the artificial leather comprises: a nonwoven fabric composed of a fiber obtained by eluting an easily eluted component from a composite fiber comprising the easily eluted component composed of a polyester-based polymer and a hardly eluted component; and an elastomer. The average value of the area of the elastomer that is exposed to the sheet surface portion is 0.1 mmor less.

Description

The present invention relates to a substrate for artificial leather having good surface quality and excellent wear characteristics, and a method for producing the same.

  Artificial leather is generally obtained by imparting a polymer elastic body to a nonwoven fabric obtained by entanglement of ultrafine fiber-generating fibers to express ultrafine fibers. Examples of the method of entanglement of the composite fiber include needle punch and water jet punch, etc. In general, the entanglement by the needle punch is the friction between the needle material and the fiber, the rigidity, strength and crimp of the raw cotton, etc. Is known to exhibit complex behavior.

  The physical properties such as the quality and friction characteristics of artificial leather tend to be better as the density of the fibers constituting the nonwoven fabric is higher and denser. Therefore, as a base for artificial leather, it is generally required to use a non-woven fabric with high entanglement and high density. One solution to this requirement is to increase the number of needle punches and orient the fibers in the thickness direction. Therefore, a polymer that can increase the rigidity of the fiber has been preferably used so that it can withstand repeated needle punching. For example, the use of specific polystyrene having high rigidity as the sea component of the sea-island type composite fiber, which is an ultrafine fiber-generating fiber, has succeeded in high entanglement in the needle punching process (see Patent Document 1). ).

In recent years, with the growing awareness of the environment, production processes that do not use organic solvents have attracted attention. Copolymerization, which has low frictional resistance between fibers and needles and can be easily dissolved by alkali treatment when ultrafine fibers are generated. Various attempts have been made as attempts using a polyester-based sea component (see Patent Document 2). However, since polyester fibers have lower fiber rigidity than polymers typified by polystyrene and the like, the non-woven fabric is stretched in the thickness direction due to the friction between the needle and the fibers that pierce in the thickness direction when needle punching is performed. Increasing the number of needle punches in order to obtain sufficient entanglement is not only entangled, the fibers constituting the nonwoven fabric are not entangled, the density is increased and the flexibility is impaired. There was a tendency for the wear properties to be reduced as a leather substrate. Further, the hole formed in the thickness direction by the needle punch is easily filled with the polymer elastic body provided in the subsequent process, and tends to be manifested as a mass of the polymer elastic body on the surface of the artificial leather substrate. .
As described above, in the prior art, it has been difficult to obtain a high-entangled and high-quality artificial leather substrate using low-rigidity composite fibers such as polyester composite fibers.

Japanese Patent Publication No.55-20011 JP 2001-55670 A

  Therefore, in view of the above-described problems of the prior art, an object of the present invention is to suppress the exposure of the polymer elastic body on the surface of the artificial leather substrate, to have excellent surface quality, and to have a high friction characteristic. It is in providing the manufacturing method.

The substrate for artificial leather of the present invention comprises a non-woven fabric comprising a fiber obtained by elution treatment of the above-mentioned elution component from a composite fiber comprising an elution component and an elution component comprising a polyester polymer, and a polymer. An artificial leather substrate comprising an elastic body, wherein the average area of the polymer elastic body exposed on the seat surface is 0.1 mm ² or less.
According to a preferred embodiment of the base material for artificial leather of the present invention, the wear loss in the wear resistance test measured according to JIS L1096 (2010) 8.17.5 E method (Martindale method) furniture load (12 kPa) is 10 mg or less.

In addition, the manufacturing method of the base for artificial leather includes a non-woven fabric made of a fiber obtained by elution treatment of the above-mentioned elution component from a composite fiber consisting of an elution component made of a polyester polymer and an elution component, and A method for manufacturing a base for artificial leather made of a polymer elastic body, wherein the nonwoven fabric or the nonwoven fabric and a woven or knitted fabric are integrated by needle punching. area at 0.10 mm ² or more 0.15 mm ² or less, and, in the manufacturing method of artificial leather substrate for barb depth and performing a needle punching using a 0.07mm following needle than 0.05mm is there.

  According to the present invention, in the needle punch, the densification of the nonwoven fabric due to friction between the needle and the composite fiber is suppressed, and the voids in the nonwoven fabric are reduced, so that the mass of the polymer elastic body in the substrate for artificial leather is refined. Thus, a mass of a polymer elastic body is hardly noticeable on the surface of the sheet, an excellent surface quality, and a substrate for artificial leather having high wear characteristics can be obtained.

  It is important that the composite fiber which is the base (raw material) of the fiber constituting the base for artificial leather of the present invention is a composite fiber composed of an easily eluting component composed of a polyester-based polymer and an easily eluting component.

  As an easily eluting component constituting the composite fiber used in the present invention, for example, it is preferable that one component contains a polyethylene terephthalate-based polyester mainly composed of an ethylene terephthalate unit, and a part of the terephthalic acid component A polyester in which is replaced with another difunctional carboxylic acid component is preferably used. Similarly, a polyester in which a part of the ethylene glycol component is replaced with another polyol component is preferably used. In particular, in order to obtain excellent alkali weight loss, a copolymerized polyester obtained by copolymerizing 3 to 12 mol% of 5-sodium sulfoisophthalic acid, and 1 to 10% by weight of polyalkylene glycol in the copolymerized polyester. A polyester composition is preferably used. The copolymerization ratio of 5-sodium sulfoisophthalic acid is more preferably in the range of 5 to 11 mol%.

  Examples of the bifunctional carboxylic acid other than terephthalic acid used in the present invention include aromatic, aliphatic such as isophthalic acid, naphthalene dicarboxylic acid, diphenyldicarboxylic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, etc. Aromatic and alicyclic bifunctional carboxylic acids are preferably used.

  Examples of polyol compounds other than ethylene glycol include aliphatic, alicyclic, and aromatic such as tetramethylene glycol, hexamethylene glycol, cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A, and bisphenol S. Group polyol compounds are preferably used.

  Examples of the hardly eluting component constituting the composite fiber used in the present invention include the above-mentioned polyester, polyamide, polyolefin, polyphenylene sulfide, and the like. Many polycondensation polymers represented by polyester and polyamide have a high melting point and are preferably used in the present invention because they exhibit good performance when used as, for example, a base for artificial leather. Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, and potytrimethylene terephthalate. Specific examples of the polyamide include nylon 6, nylon 66, nylon 12, and the like.

  In the present invention, easy elution of an easily eluted component comprising a polyester-based polymer means that the solubility with respect to the hardly eluted component is 100 times or more in a solvent such as an organic solvent or an aqueous solution such as alkali, preferably 200 More than double. In the elution process of easily eluting components, by adjusting the concentration and temperature of the eluting aqueous solution, a solubility difference of 100 times or more can be obtained, the hardly eluting components are hardly damaged, and the difficult eluting component is dispersed. A sheet with a good polyurethane can be obtained. A sodium hydroxide aqueous solution is preferably used as the aqueous alkali solution used for elution of the easily eluted components, and the concentration of the aqueous solution for obtaining sufficient alkali weight loss is preferably 1 to 20%, and 2 to 10%. It is a more preferable embodiment. The temperature of the sodium hydroxide aqueous solution is preferably 70 to 98 ° C, more preferably 85 to 95 ° C.

  The composite fiber used in the present invention is a polymer mutual array fiber according to Japanese Patent Publication No. 48-2216, a mixed spun fiber according to Japanese Patent Publication No. 51-21041, and a split type according to Japanese Patent Publication No. 9-310230. A composite fiber or the like can be preferably used.

  The average fiber diameter of the ultrafine fibers obtained from the composite fibers is preferably 0.1 to 10 μm. When the average fiber diameter is preferably 10 μm or less, more preferably 5 μm or less, for example, when a suede-like artificial leather is used, a good touch can be obtained. On the other hand, when the average fiber diameter is preferably 0.1 μm or more, more preferably 0.5 μm or more, excellent fiber strength and rigidity can be maintained.

  As a base for artificial leather of the present invention, a short fiber nonwoven fabric obtained by forming a staple fiber web using a card or a cross wrapper and then needle punching or water jet punching, a spunbond method or a melt blow method It is possible to employ a long-fiber nonwoven fabric obtained from the above, a nonwoven fabric obtained by a papermaking method, and the like. Among these, short fiber nonwoven fabrics and spunbond nonwoven fabrics are preferably used because those having good thickness uniformity and the like can be obtained.

  In the artificial leather substrate of the present invention, for the purpose of improving the strength, a woven fabric or a knitted fabric is laminated and lined with a nonwoven fabric. When the nonwoven fabric and the woven or knitted fabric are laminated and integrated with a needle punch, it is preferable that the yarn of the woven or knitted fabric is a strong twisted yarn in order to prevent damage to the fibers constituting the woven or knitted fabric by the needle punch. The twist number of the yarn is preferably in the range of 700 T / m to 4500 T / m. Moreover, the fiber diameter of the fiber which comprises a woven / knitted fabric can use the same thing as the fiber diameter of the ultrafine fiber which comprises a nonwoven fabric, or a thinner thing.

  As a solvent for dissolving an easily soluble polyester polymer (sea component) which is an easily eluted component from the composite fiber used in the present invention, if the sea component is polylactic acid or copolymer polyester, sodium hydroxide or the like can be used. An alkaline aqueous solution can be used. The ultrafine fiber generation processing (sea removal treatment) can be performed by immersing a non-woven fabric made of a composite fiber in a solvent and squeezing it. In addition, for the ultrafine fiber generation processing, known apparatuses such as a continuous dyeing machine, a vibro-washer type sea removal machine, a liquid dyeing machine, a Wins dyeing machine, and a jigger dyeing machine can be used.

As the form of the ultrafine fiber bundle obtained after removing the readily soluble polymer from the composite fiber used in the present invention, the ultrafine fibers may be somewhat separated from each other, or may be partially bonded, It may be aggregated.
The base body for artificial leather of the present invention is obtained by applying a polymer elastic body to a fiber entangled body such as the above-described nonwoven fabric. Thereby, it is possible not only to prevent the ultrafine fibers from falling off the artificial leather substrate due to the binder effect of the polymer elastic body, but also to impart an appropriate cushioning property.

The needle used for the production of the nonwoven fabric constituting the substrate for artificial leather of the present invention has a needle barb (cut) at the tip of the needle, and the cross-sectional area of the nonwoven fabric sheet penetrating portion is 0.08 mm ² or more and 0. .20Mm ² or less are preferred, 0.10 mm ² or more 0.15 mm ² or less being more preferred. By setting the cross-sectional area of the needle to 0.15 mm ² or less, voids in the nonwoven fabric structure generated by the needle punch can be miniaturized, and an artificial leather substrate having a fine surface quality can be obtained. In addition, when the polymer elastic body is integrated with the polymer elastic body, the polymer elastic body that has entered the gap is also as small as the size of the gap, so that the dyed spots of the ultrafine fibers after dyeing and the polymer elastic body can be made inconspicuous. . When the cross-sectional area is less than 0.10 mm ² , the strength of the needle is impaired, and the needle may break due to an impact with the nonwoven fabric during needle punching.

  Further, the barb depth of the needle is 0.05 mm or more and 0.07 mm or less regardless of the cross-sectional area of the needle. If the barb depth indicated by the sum of kick-up and throat depth is less than 0.05 mm, the fiber entanglement becomes insufficient, the fiber density of the artificial leather base is impaired, and the wear characteristics tend to be reduced. . Further, when the barb depth is deeper than 0.07 mm, the number of fibers caught on the barb increases, the voids in the nonwoven fabric structure increase, and as in the case where the needle cross-sectional area is increased, the ultrafine fibers and the polymer elastic body Dyed spots may be noticeable and the surface quality may be greatly impaired.

  Polyurethane, polyurea, polyurethane / polyurea elastomer, polyacrylic acid, acrylonitrile / butadiene elastomer, styrene / butadiene elastomer, etc. can be used as the polymer elastic body imparted to the artificial leather substrate of the present invention. From the viewpoint of cushioning properties, polyurethane is preferably used.

  Examples of the polyurethane include at least one polymer diol selected from polyester diols having an average molecular weight of 500 to 3000, polyether diol, polycarbonate diol, polyester polyether diol, and the like, and 4,4′-diphenylmethane. At least one diisocyanate selected from aromatic diisocyanates such as diisocyanates, alicyclic diisocyanates such as isophorone diisocyanate, and aliphatic diisocyanates such as hexamethylene diisocyanate, ethylene glycol, butanediol, ethylenediamine and 4,4 ′ -Polyurethane obtained by reacting at least one low molecular weight compound having two or more active hydrogen atoms such as diaminodiphenylmethane at a predetermined molar ratio and its Sex products thereof.

  The weight average molecular weight of the polyurethane elastomer is preferably 50,000 to 300,000. By setting the weight average molecular weight to preferably 50,000 or more, more preferably 100,000 or more, and further preferably 150,000 or more, it is possible to maintain the strength of the artificial leather substrate and prevent the fine fibers from falling off. it can. Further, by making the weight average molecular weight preferably 300,000 or less, more preferably 250,000 or less, it is possible to suppress the increase in the viscosity of the polyurethane solution and facilitate the impregnation of the ultrafine fiber layer.

  In addition, the polymer elastic body may contain an elastomer resin such as polyester, polyamide, and polyolefin, an acrylic resin, and an ethylene-vinyl acetate resin.

  The polymer elastic body used in the present invention includes a pigment such as carbon black, a dye antioxidant, an antioxidant, a light-resistant agent, an antistatic agent, a dispersant, a softening agent, a coagulation adjusting agent, if necessary. Additives such as flame retardants, antibacterial agents and deodorants can be incorporated.

  Further, the polymer elastic body can be used either dissolved in an organic solvent or dispersed in water.

  The content of the elastic polymer contained in the artificial leather substrate of the present invention is preferably 5 to 200% by mass. Depending on the content of the polymer elastic body, the surface state, cushioning property, hardness and strength of the artificial leather substrate can be adjusted. When the content is preferably 5% by mass or more, more preferably 20% by mass or more, and still more preferably 30% by mass or more, fiber dropout can be reduced. On the other hand, when the content is 200% by mass or less, more preferably 100% by mass or less, and still more preferably 80% by mass or less, a state in which ultrafine fibers are uniformly dispersed on the sheet surface can be obtained.

The area of the polymer elastic body exposed on the surface portion of the artificial leather substrate of the present invention is preferably 0 mm ² or more and 0.2 mm ² or less, more preferably 0 mm ² or more and 0.1 mm ² or less. . A good surface quality can be obtained by making the dyed spots of the ultrafine fibers and the polymer elastic body constituting the artificial leather substrate smaller and less noticeable.

  The ultrafine fiber generation processing may be performed before the napping treatment or after the napping treatment.

  The substrate for artificial leather of the present invention not only has excellent dyed spots of ultrafine fibers and polymer elastic bodies, but also has no loss of entanglement between fibers and is excellent in structural stability. Therefore, the wear characteristics are excellent, and the grade is grade 3 or higher in the Martindale test (JIS L1096 wear strength E method). The wear loss is preferably 0 mg or more and 20 mg or less, more preferably 0 mg or more and 10 mg or less, and it can be suitably used as a substrate for artificial leather for a wide range of uses such as clothing, miscellaneous goods and industrial materials.

  Next, the method for producing the artificial leather substrate of the present invention will be described.

  As the composite fiber used in the production of the artificial leather substrate of the present invention, two-component thermoplastic resins having different solubility in a solvent or the like are used for the sea component and the island component, and the sea component is dissolved and removed using a solvent or the like. By doing so, it is possible to use sea-island type fibers that are ultrafine fibers composed of island components, and it is important that they are composed of easily extractable components composed of polyester polymers and difficultly extractable components.

  As the sea-island type fiber, a sea-island type composite fiber that uses a sea-island type composite base and spins the sea component and the island component by mutual arrangement, and mixed spinning that mixes and spins the sea component and the island component. Although there are fibers, etc., the sea-island type composite fiber is particularly useful because it can obtain ultrafine fibers of uniform fineness, and can obtain a sufficiently long ultrafine fiber that contributes to the strength of the sheet (fiber entanglement). Preferably used.

  The composite fiber used in the present invention is preferably given buckling crimp. This is because crimping improves the entanglement between fibers when a short fiber nonwoven fabric is formed, and enables high entanglement at high density. In order to impart crimps, a normal stuffing box type crimper is preferably used, but in order to obtain the artificial leather substrate of the present invention, the total value of the average conjugate fiber fineness of the conjugate fibers to be put into the crimper, It is preferable to appropriately adjust the crimper temperature, the crimper load, the indentation pressure, and the like. Of these, the crimper temperature (the temperature at which crimping is applied) is the most important. By setting the crimper temperature to preferably 80 ° C. or less, the composite fiber crimp is gently heat set, It is possible to prevent the entanglement behavior of the fibers from being suppressed.

  The dissolution and removal of the sea component of the composite fiber used in the present invention can be carried out at any stage after the raising treatment, before and after applying the polymer elastic body when the substrate for artificial leather is used.

  In the present invention, as described above, as a method for obtaining a nonwoven fabric composed of composite fibers, a method of entanglement of a fiber web with a needle punch or a water jet punch, a spun bond method, a melt blow method, a paper making method, or the like may be employed. Among them, the method of passing through the needle punch is preferable for the above-described fiber bundle mode, and the woven or knitted fabric can be integrated in the process.

The number of needle punches is preferably 1000 to 6000 / cm ² , more preferably 2500 to 5000 / cm ² . The composite fiber mentioned in the present invention has low rigidity, is easy to stick in the thickness direction when needle punching is performed, and fiber entanglement is difficult to proceed. Therefore, it is more preferable to set the number of punching to 2500 / cm ² or more, whereby sufficient entanglement can be obtained and a dense feeling and friction characteristics can be obtained.

On the other hand, by setting the number of punching to 5000 pieces / cm ² or less, it is possible to prevent deterioration of workability due to excessive needle punching, damage to composite fibers and reduction in strength, and further, high density can be suppressed. The generated voids in the nonwoven fabric can be reduced to prevent the color spots between the fibers and the polymer elastic body from conspicuous.

In the portion penetrating the needle of the nonwoven fabric, the cross-sectional area of the thickest part is important in the range of 0.10~0.15mm ^2. By making the cross-sectional area 0.15 mm ² or less, the voids in the nonwoven fabric can be reduced, and color spots between the ultrafine fibers and the polymer elastic body can be prevented from standing out, and the needle surface in the needle punch and the nonwoven fabric can be prevented. Friction with the composite fiber inside is suppressed, and densification of the nonwoven fabric is prevented. On the other hand, by setting the cross-sectional area to 0.10 mm ² or more, it is possible to prevent the needle from being broken by the impact of the needle punch.

  In the needle used for the needle punching process, the number of needle barbs (cuts) is preferably 1 to 9. By using one or more needle barbs, it is possible to efficiently entangle the composite fibers. On the other hand, damage to the composite fiber can be suppressed by setting the needle barbs to 9 or less.

  The number of composite fibers caught on the needle barb is determined by the shape of the barb and the diameter of the composite fiber. Therefore, the barb shape used in the needle punching process is important for determining the structure of the nonwoven fabric, the undercut angle is 0 to 40 °, the barb depth is 40 to 130 μm, and the slow length is 0.5 to 1.0 mm. Are preferably used, but a needle having a barb depth of 50 to 70 μm is more preferably used. When the barb depth is less than 50 μm, the entanglement of the composite fibers is impaired, the form of the nonwoven fabric becomes unstable, the processability is deteriorated, and the denseness of the artificial leather substrate may be impaired. Further, when the barb depth is deeper than 70 μm, the number of the composite fibers caught on the barb increases, and the voids of the nonwoven fabric formed by the needle punch increase, and even after the base for artificial leather is formed, the voids tend to be conspicuous. is there.

The apparent density of the nonwoven fabric after the needle punch treatment is preferably 0.15 to 0.30 g / cm ³ , more preferably 0.23 to 0.25 g / cm ³ . By setting the apparent density to 0.23 g / cm ³ or more, not only the form is more stable and the workability is stabilized as a substrate for artificial leather, but also a fine surface quality and high friction characteristics are obtained. On the other hand, by setting the apparent density to 0.25 g / cm ³ or less, it is possible to maintain a sufficient space for providing the polymer elastic body in the nonwoven fabric. The apparent density is more preferably 0.23 to 0.25 g / cm ³ .

  In the nonwoven fabric composed of the composite fibers thus obtained, the viewpoint of densification of fibers important in quality, the viewpoint of reducing the gap formed by the needle punch, and the area of polyurethane generated in the gap are reduced. In view of this, the wet heat shrinkage of the composite fiber used is preferably 10 to 50%.

  In the present invention, as described above, the solvent for dissolving the easily soluble polymer (sea component) that is an easily eluted component from the nonwoven fabric composed of the composite fiber is sodium hydroxide if the sea component is polylactic acid or copolymer polyester. An alkaline aqueous solution such as can be used. The ultrafine fiber generation processing (sea removal treatment) can be performed by immersing a non-woven fabric made of a composite fiber in a solvent and squeezing it.

  In addition, for the ultrafine fiber generation processing, known apparatuses such as a continuous dyeing machine, a vibro-washer type sea removal machine, a liquid dyeing machine, a Wins dyeing machine, and a jigger dyeing machine can be used. The ultrafine fiber generation processing may be performed before the napping treatment or after the napping treatment.

  The polymer elastic body can be applied before the ultrafine fiber generation processing or can be applied after the ultrafine fiber generation processing.

  In the present invention, N, N′-dimethylformamide, dimethyl sulfoxide, or the like is preferably used as a solvent used for imparting polyurethane as a polymer elastic body, but a water dispersion type in which polyurethane is dispersed as an emulsion in water. It can also be used as a polyurethane liquid.

  A solution of the polymer elastic body is applied to the nonwoven fabric by immersing the nonwoven fabric in a solution of the polymer elastic body dissolved in a solvent, and then dried to substantially solidify and solidify the polymer elastic body. In the case of a solvent-based polyurethane solution, it can be solidified by immersing it in a non-soluble solvent, and in the case of a water-dispersed polyurethane solution having gelling properties, it is dried and solidified after being gelled. It can be solidified by a method or the like. In drying, it can be heated at a temperature that does not impair the performance of the nonwoven fabric and the polymer elastic body.

  The artificial leather substrate of the present invention can have nappings formed on at least one side. The napping treatment can be performed using a sandpaper or a roll sander. In particular, by using sandpaper, uniform and dense napping can be formed. Furthermore, in order to form uniform napping on the surface of the artificial leather substrate, it is preferable to reduce the grinding load. In order to reduce the grinding load, for example, it is more preferable that the number of buffing stages is multistage buffing with three or more stages, and the number of sandpaper used in each stage is in the range of 150 to 600 of JIS regulations. It is.

  The artificial leather substrate of the present invention can contain functional agents such as dyes, pigments, softeners, anti-pilling agents, antibacterial agents, deodorants, water repellents, light proofing agents, and weathering agents. .

  The substrate for artificial leather of the present invention is preferably dyed. As the dyeing means, a liquid dyeing machine is preferably used because it can be softened by adding a stagnation effect simultaneously with dyeing the sheet. The dyeing temperature is preferably 70 to 120 ° C. As the dye, a disperse dye is preferably used when the hardly-eluting component is polyester. Further, reduction washing can be performed after dyeing.

The artificial leather substrate of the present invention and the artificial leather that can be subjected to finishing treatment with a softener such as silicone, an antistatic agent, a water repellent, a flame retardant and a light fastener as necessary are as described above. It is important that the average value of the area of the polymer elastic body exposed on the sheet surface is 0.1 mm ² or less. By setting the average value of the area of the polymer elastic body to 0.1 mm ² or less after dyeing, the polymer elastic body is scattered on the sheet surface as a light-colored part in ultrafine fibers that occupy most of the sheet surface as a dark-colored part. Is not conspicuous and good surface quality is obtained. In addition, for the purpose of improving the uniformity of dyeing, it is preferable to use a dyeing assistant at the time of dyeing, and further, finishing treatment such as a softener such as silicone, an antistatic agent, a water repellent, a flame retardant, and a light resistant agent is performed. Also good. The finishing treatment can be performed in the same bath as the dyeing even after dyeing.

  The substrate for artificial leather and the artificial leather using the same according to the present invention are excellent in quality and frictional properties, so that clothes, shoes, sundries, automobile interior materials (car seats, ceiling materials, etc.), CDs, DVD curtains, and polishing cloths are used. It is suitably used for industrial materials such as cleaning tapes and wiping cloths.

[Measuring method and processing method for evaluation]
(1) Apparent density of substrate for artificial leather The basis weight (g / m ² ) was measured according to JIS L1913 6.2 (2010), and dial thickness gauge Ozaki Manufacturing Co., Ltd., trade name “Peacock H” (registered trademark) ) To measure the thickness (mm). The apparent density (g / cm ³ ) was calculated using the basis weight and thickness values.

(2) Martindale abrasion test JIS L1096 (2010) 8.17.5 E method (Martindale method) After wearing 20000 times in the abrasion resistance test measured according to furniture load (12 kPa) The weight loss of the test cloth was evaluated. A wear loss of 10 mg or less was considered good performance.

(3) Area of the polymer elastic body on the surface of the artificial leather substrate The surface of the artificial leather substrate was observed with a scanning electron microscope (VE-7800 manufactured by SEM KEYENCE) and extracted randomly within the field of view. The area of each polymer elastic body was measured. However, this was performed at three locations, the areas of a total of 15 polymer elastic bodies were measured, and the average value was calculated by rounding off the second decimal place. Those having an area of 0.1 mm ² or less were regarded as having good quality.

(4) Surface quality evaluation Denseness and dyed spots on the surface of artificial leather products were evaluated by sensory inspection of 10 subjects. Those judged that 7 or more were excellent (circle ◯), those judged that 3 to 6 were excellent (triangle Δ), and those judged that 3 or less were excellent were classified as (X). (Triangles △) and (circles ○) were accepted.

[Example 1]
<Raw cotton>
(Island component polymer)
PET having a melting point of 260 ° C. and MFR of 46.5 was used.

(Sea component polymer)
PET (copolymerized PET1) obtained by copolymerizing 8 mol% of sodium 5-sulfoisophthalate having a melting point of 240 ° C. and MFR of 100 was used.

(Spinning, drawing)
Using the sea component polymer and island component polymer described above, melting was performed using a 16 island / hole sea-island type composite spinneret at a spinning temperature of 285 ° C., an island / sea mass ratio of 55/45, and a spinning speed of 1200 m / min. Spinned. Next, the film was stretched in two stages in a liquid bath at a temperature of 72 ° C. so that the total magnification was 3.4 times, and crimped at a crimper temperature of 65 ° C. using a stuffing box type crimper. The obtained conjugate fiber had a single fiber fineness of 4.5 dtex. This composite fiber was cut into a fiber length of 51 mm to obtain a raw cotton of sea-island type composite fiber.

<Nonwoven fabric>
Using the raw cotton obtained as described above, a laminated web was formed through a card and a cross wrapper process. Next, using a needle punch machine in which one needle having a barb depth of 0.05 mm and a cross-sectional area of the nonwoven fabric penetration portion of 0.11 mm ² was implanted, a needle punch at a needle depth of 7 mm and a number of punches of 4500 / cm ² A nonwoven fabric having a basis weight of 800 g / m ² and an apparent density of 0.234 g / cm ³ was produced. The obtained non-woven fabric was good because voids due to needle punching were not noticeable.

<Water-dispersed polyurethane liquid>
Sodium sulfate as a heat-sensitive gelling agent is added to a nonionic forced emulsification type polyurethane emulsion (polycarbonate type) in an amount of 4% by mass relative to the solid content of the polyurethane, so that the concentration of the polyurethane solution is 10% by mass. Adjusted.
<Base for artificial leather>
The nonwoven fabric was subjected to hot water shrinkage treatment at a temperature of 98 ° C. for 3 minutes and dried at a temperature of 100 ° C. for 5 minutes. Thereafter, the above water-dispersed polyurethane liquid is applied to the nonwoven fabric and dried with hot air at a drying temperature of 125 ° C. for 5 minutes to obtain a polyurethane-attached sheet in which the amount of polyurethane attached is 35% by mass with respect to the island components of the nonwoven fabric. It was.

The polyurethane-coated sheet obtained as described above was heated to a temperature of 90 ° C. so that the difference in solubility between the easily eluted component (sea component polymer) and the hardly eluted component (island component polymer) was 200 times or more. It was immersed in a 2% strength sodium hydroxide aqueous solution and treated for 30 minutes to dissolve and remove the sea component polymer from the composite fiber. The obtained sheet with polyurethane had little damage to difficult-to-elute components and was well dispersed. After that, it is cut in the thickness direction by a half-cutting machine with an endless band knife, and the non-half-cut surface is ground in three stages using JIS # 320 sandpaper to form napped hair, and then dyed with a liquid dyeing machine. A substrate for artificial leather having an area of the polymer elastic body exposed on the surface of 0.04 mm ² was produced. The obtained artificial leather base had good dyeing spots and fineness, and the wear loss was as good as 6 mg. The results are shown in Table 1.

[Example 2]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was performed in the same manner as in Example 1 except that the above raw cotton was used and a needle having a barb depth of 0.06 mm was used. A nonwoven fabric having a basis weight of 794 g / m ² and an apparent density of 0.238 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather having an area of the polymer elastic body exposed on the surface of 0.05 mm ² was produced in the same manner as in Example 1 except that the above-described nonwoven fabric was used. The obtained substrate for artificial leather had good dyeing spots and fineness, and the weight loss by abrasion was also as good as 7 mg. The results are shown in Table 1.

[Example 3]
<Raw cotton>
(Island component polymer, sea component polymer)
The same polymer used in Example 1 was used.

(Spinning / drawing)
A composite fiber with a composite fineness of 4.5 dtex was prepared in the same manner as in Example 1 except that the above sea component polymer and island component polymer were used and a 2.0 mass% melt blend of polyethylene glycol having a molecular weight of 20,000 was used. Obtained. The obtained composite fiber was cut into a fiber length of 51 mm to obtain a raw material of sea-island type composite fiber.

<Nonwoven fabric>
Processing was performed in the same manner as in Example 1 using the above raw cotton. A nonwoven fabric having a basis weight of 824 g / m ² and an apparent density of 0.240 g / cm ³ was obtained.

<Base for artificial leather>
A sheet with polyurethane was obtained in the same manner as in Example 2 except that the above nonwoven fabric was used. The obtained sheet with polyurethane has little damage to the hardly-eluting component, and the dispersion state is better than that of Example 1. The substrate for artificial leather has an area of the polymer elastic body exposed on the surface of 0.05 mm. ^2. Dye spots and fineness were good, and wear loss was also good at 6 mg. Moreover, it had a softer tactile feel than Example 1. The results are shown in Table 1.

[Example 4]
<Raw cotton>
(Island component polymer)
The same polymer used in Example 1 was used.

(Sea component polymer)
A PET (copolymerized PET2) having a melting point of 240 ° C. and 5 mol% of MFR100 sodium 5-sulfoisophthalate was used.

(Spinning, drawing)
A raw material of sea-island type composite fiber was obtained in the same manner as in Example 1 except that the above sea component polymer was used.

<Nonwoven fabric>
Using the above raw cotton, processing was carried out in the same manner as in Example 2. A nonwoven fabric having a basis weight of 813 g / m ² and an apparent density of 0.238 g / cm ³ was obtained.

<Base for artificial leather>
A sheet with polyurethane was obtained in the same manner as in Example 2 except that the above nonwoven fabric was used. The obtained sheet with polyurethane had little damage to the hardly-eluting component, but was slightly inferior in dispersibility to that of Example 1. The obtained artificial leather for substrates, in 0.06 mm ² area of the elastic polymer is exposed on the surface, good uneven dyeing and denseness, was good and 6mg abrasion loss. The results are shown in Table 1.

[Example 5]
<Raw cotton>
(Island component polymer)
The same polymer used in Example 1 was used.

(Sea component polymer)
A PET (copolymerized PET3) having a melting point of 240 ° C. and 11 mol% of MFR100 sodium 5-sulfoisophthalate was used.

(Spinning, drawing)
A raw material of sea-island type composite fiber was obtained in the same manner as in Example 2 except that the above sea component polymer was used.

<Nonwoven fabric>
Using the above raw cotton, processing was carried out in the same manner as in Example 2. A nonwoven fabric having a basis weight of 829 g / m ² and an apparent density of 0.238 g / cm ³ was obtained.

<Base for artificial leather>
A sheet with polyurethane was obtained in the same manner as in Example 2 except that the above nonwoven fabric was used. The obtained sheet with polyurethane was excellent in dispersibility, but many damages to the hardly eluted component were observed. The obtained artificial leather for substrates, in 0.06 mm ² area of the elastic polymer is exposed on the surface, good uneven dyeing and denseness, was also 7mg and good abrasion loss. The results are shown in Table 1.

[Example 6]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was performed in the same manner as in Example 2 except that the above raw cotton was used and a needle having a cross-sectional area of 0.15 mm ^{2 in} the nonwoven fabric penetrating portion was used. A nonwoven fabric having a basis weight of 794 g / m ² and an apparent density of 0.243 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather was produced in the same manner as in Example 1 except that the above nonwoven fabric was used. The area of the polymer elastic body exposed on the surface of the obtained artificial leather substrate was a little as large as 0.08 mm ² , so that the dyeing spots were slightly deteriorated, but the fineness was good and the wear loss was reduced. Was 8 mg. The results are shown in Table 1.

[Example 7]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was carried out in the same manner as in Example 1 except that the above raw cotton was used and a needle having a barb depth of 7 mm was used. A nonwoven fabric having a basis weight of 794 g / m ² and an apparent density of 0.244 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather was produced in the same manner as in Example 1 except that the above nonwoven fabric was used. The area of the polymer elastic body exposed on the surface of the obtained artificial leather substrate was slightly increased to 0.08 mm ² , so that the dyeing spots were slightly deteriorated, but the fineness was good and the weight loss was reduced. Was 5 mg. The results are shown in Table 1.
[Example 8]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Using the above raw cotton, processing was carried out in the same manner as in Example 2. A nonwoven fabric having a basis weight of 794 g / m ² and an apparent density of 0.239 g / cm ³ was obtained.

<Polyurethane liquid>
A DMF (dimethylformamide) solution of polycarbonate polyurethane was adjusted to a solid content concentration of 12%.
<Base for artificial leather>
The nonwoven fabric is shrunk with hot water at a temperature of 96 ° C., then impregnated with an aqueous PVA (polyvinyl alcohol) solution, and dried with hot air at a temperature of 110 ° C. for 10 minutes, whereby the PVA mass relative to the mass of the sheet substrate is 22 A sheet substrate of mass% was obtained. This sheet substrate was immersed in an alkali to dissolve and remove the sea component polymer to obtain a sea removal sheet in which ultrafine fibers and plain fabrics were entangled. The seawater-free sheet composed of the nonwoven fabric and the plain fabric thus obtained was immersed in a polyurethane DMF (dimethylformamide) solution adjusted to a solid content concentration of 12%, and then an aqueous solution having a DMF concentration of 30%. The polyurethane was coagulated in it. Thereafter, PVA and DMF were removed with hot water and dried with hot air at a temperature of 110 ° C. for 10 minutes. Furthermore, it is cut in the thickness direction by a half-cutting machine with an endless band knife, and the non-half-cut surface is ground in three stages using JIS # 320 sandpaper to form napped hair, which is then dyed with a liquid dyeing machine. A substrate for artificial leather having an area of the polymer elastic body exposed on the surface of 0.09 mm ² was prepared. The obtained base for artificial leather had slightly noticeable dyeing spots, but had good density and a weight loss of 6 mg. The results are shown in Table 1.
[Example 9]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was performed in the same manner as in Example 7 except that the above raw cotton was used and a needle having a cross-sectional area of 0.15 mm ^{2 in} the nonwoven fabric penetrating portion was used. A nonwoven fabric having a basis weight of 794 g / m ² and an apparent density of 0.248 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather was produced in the same manner as in Example 1 except that the above nonwoven fabric was used. The area of the polymer elastic body exposed on the surface of the obtained artificial leather substrate was slightly increased to 0.10 mm ² , so that the dyed spots tended to deteriorate. Further, the fineness was good, and the weight loss by abrasion was 5 mg. The results are shown in Table 1.

[Comparative Example 1]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was carried out in the same manner as in Example 2 except that the above-mentioned raw cotton was used and a needle having a cross-sectional area of 0.17 mm ^{2 in} the nonwoven fabric penetrating portion was used. The voids of the nonwoven fabric produced by needle punching were much larger than in Example 1. A nonwoven fabric having a basis weight of 812 g / m ² and an apparent density of 0.251 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather was produced in the same manner as in Example 1 except that the above nonwoven fabric was used. The area of the polymer elastic body exposed on the surface of the obtained artificial leather substrate was 0.16 mm ² , and the dyed spots were at an unacceptable level. Further, the fineness was a reject level because voids in the needle punch remained and there were innumerable holes. Moreover, the wear loss was 6 mg. The results are shown in Table 1.

[Comparative Example 2]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was carried out in the same manner as in Example 2 except that the above raw cotton was used and a needle having a cross-sectional area of 0.08 mm ^{2 in} the nonwoven fabric penetrating portion was used. By making the needle thinner, the strength of the needle decreased, and the needle was broken by the impact when piercing the nonwoven fabric, making it impossible to continue processing. The results are shown in Table 1.

[Comparative Example 3]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was carried out in the same manner as in Example 1 except that the above raw cotton was used and a needle having a barb depth of 0.04 mm was used. Since the entanglement of ultrafine fibers was insufficient, the nonwoven fabric was finished in a slightly unstable form. The basis weight of the nonwoven fabric was 724 g / m ² , and the apparent density was 0.231 g / cm ³ .

<Base for artificial leather>
The same procedure as in Example 1 was carried out except that the above-mentioned nonwoven fabric was used. However, the obtained artificial leather substrate did not exhibit a suede-like surface quality, and the wear loss was 18 mg. The results are shown in Table 1.

[Comparative Example 4]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was carried out in the same manner as in Example 1 except that the above raw cotton was used and a needle having a barb depth of 0.08 mm was used. The voids in the nonwoven fabric produced by the needle punch became slightly larger. A nonwoven fabric having a basis weight of 782 g / m ² and an apparent density of 0.250 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather was produced in the same manner as in Example 1 except that the above nonwoven fabric was used. The area of the polymer elastic body exposed on the surface of the obtained artificial leather substrate was 0.11 mm ² , and the dyed spots were at an unacceptable level. However, the fineness of the ultrafine fibers was good, and the weight loss by abrasion was 5 mg. The results are shown in Table 1.

[Comparative Example 5]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was carried out in the same manner as in Example 1 except that the above raw cotton was used and a needle having a barb depth of 0.10 mm was used. The void of the nonwoven fabric produced by the needle punch was larger than that of Comparative Example 4. A nonwoven fabric having a basis weight of 782 g / m ² and an apparent density of 0.258 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather was produced in the same manner as in Example 1 except that the above nonwoven fabric was used. The area of the polymer elastic body exposed on the surface of the obtained artificial leather substrate was 0.14 mm ² , and the dyed spots were at an unacceptable level. However, the fineness of the ultrafine fibers was good, and the weight loss on wear was 6 mg. The results are shown in Table 1.

[Comparative Example 6]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 1 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was performed in the same manner as in Example 1 except that the above-mentioned raw cotton was used, and a needle having a barb depth of 0.04 mm and a cross-sectional area of the nonwoven fabric penetrating portion of 0.17 mm ² was used. Since the entanglement of ultrafine fibers was insufficient, the nonwoven fabric was finished in a slightly unstable form. A nonwoven fabric having a basis weight of 782 g / m ² and an apparent density of 0.240 g / cm ³ was obtained.

<Base for artificial leather>
The same procedure as in Example 1 was carried out except that the above-mentioned nonwoven fabric was used. However, the obtained artificial leather substrate did not exhibit a suede-like surface quality, and the wear loss was 18 mg.

[Comparative Example 7]
<Raw cotton>
(Island component polymer, sea component polymer, spinning, stretching)
The same polymer as that used in Example 4 was used, and a raw cotton of sea-island type composite fiber was obtained by the same method.

<Nonwoven fabric>
Processing was performed in the same manner as in Example 1 except that the above-described raw cotton was used, and a needle having a barb depth of 0.08 mm and a cross-sectional area of the nonwoven fabric penetration portion of 0.17 mm ² was used. The voids of the nonwoven fabric produced by the needle punch became the most conspicuous in the examples and comparative examples. A nonwoven fabric having a basis weight of 782 g / m ² and an apparent density of 0.260 g / cm ³ was obtained.

<Base for artificial leather>
A substrate for artificial leather was produced in the same manner as in Example 1 except that the above nonwoven fabric was used. The area of the polymer elastic body exposed on the surface of the obtained artificial leather substrate was 0.19 mm ² , and the dyed spots were at a rejected level. Further, the fineness was a reject level because voids in the needle punch remained and there were innumerable holes. Moreover, the wear loss was 6 mg. The results are shown in Table 1.

Claims (3)

A non-woven fabric made of a fiber obtained by elution treatment of the easily-eluting component from a composite fiber consisting of an easily-eluting component and an easily-eluting component made of a polyester polymer, and an artificial leather substrate made of a polymer elastic body. And an average value of the area of the polymer elastic body exposed on the sheet surface portion is 0.1 mm ² or less. The wear loss in an abrasion resistance test measured according to JIS L1096 (2010) 8.17.5 E method (Martindale method) furniture load (12 kPa) is 10 mg or less. Substrate for artificial leather. Manufacture of a base for artificial leather made of a nonwoven fabric made of a fiber obtained by elution treatment of the easy-eluting component from a composite fiber consisting of an easily-eluting component made of a polyester-based polymer and a difficult-to-elute component, and a polymer elastic body a method, the nonwoven or the nonwoven fabric and the woven or knitted fabric in the manufacturing process of the sheet to be integrated by needle punching, a needle cross-sectional area of the sheet penetrating portion is in 0.10 mm ² or more 0.15 mm ² or less, And the manufacturing method of the base | substrate for artificial leather characterized by performing a needle punch using the needle whose barb depth is 0.05 mm or more and 0.07 mm or less.