JP2006045723A - Sueded artificial leather - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide sueded artificial leather useful for furniture, car sheets, etc., requiring high durability performances for abrasion and having the high durability performances. <P>SOLUTION: The sueded artificial leather comprises a surface fiber layer composed of ultrafine fibers of polyethylene terephthalate composed of repeating units of ethylene terephthalate and is impregnated with a polyurethane resin and dyed. The sueded artificial leather is characterized as follows. (1) The intrinsic viscosity of the polyethylene terephthalate ultrafine fibers is ≥0.57 to ≤0.63; (2) the fineness of the ultrafine fibers is ≤0.5 dtex; (3) the ultrafine fibers have ≥0.16 to ≤0.22 tanδ<SB>max</SB>value after a treatment in hot water at 130°C under no tension and ≥125 to ≤160°C T<SB>max</SB>value and (4) the ultrafine fibers have ≥23% crystal integrity by wide angle X-ray diffractometry. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a suede-like artificial leather having high durability and improved quality.

  Suede-like artificial leather composed of ultra-fine polyester fibers has been marketed for furniture and car seats, mainly chairs, because of its elegant surface quality, light weight, and ease of care. However, recently, in such applications that require durability, improvement in performance is more strongly demanded from the market.

  As a technique for improving the wear resistance of suede-like artificial leather, Patent Document 1 discloses many formations of striped knitted loop-like entanglement covering the surface of the entangled layer in order to suppress hair loss on the surface. Techniques to do this are disclosed. This is an improved technology for artificial leather used in clothing, and is intended to improve wear resistance by preventing the detachment of ultrafine fibers by entanglement of ultrafine fibers on the surface of artificial leather. Because it is not up, the performance of artificial leather cannot be significantly improved.

  In Patent Document 2, the degree of polymerization of polyethylene terephthalate, which is an ultrafine fiber on the surface, is set to 0.55 dl / g or more, and the degree of crystal orientation is set to 80 to 90% to improve wear resistance and solve the whitening phenomenon. It is what. The technology disclosed here is a yarn obtained by POY (semi-undrawn yarn) having a yarn elongation of 50 to 70% and a spinning speed range of 2000 to 5000 m / min, or ordinary UDY (undrawn). The yarn obtained by lowering the draw ratio at the time of drawing the yarn) is used. However, these yarns have mechanical properties close to those of undrawn yarns, and heat shrinkage is large in the post-process, such as dyeing, where heat is applied, and the molecular orientation in the fiber axis direction is greatly relaxed. Therefore, the artificial leather having low wear performance and sufficient wear resistance cannot be obtained.

  Conventional suede-like artificial leather, when used as furniture or car seats for a long time, fibrillates the ultra-fine fibers during the wear process and changes the hue of the worn surface (hereinafter referred to as “whitening”), which is different from the hue before use. And the problem of wear that the ultrafine fibers fall off, and the problem that the ultrafine fibers are entangled and pilled during the wear process. Accordingly, there has been a strong demand for the emergence of an excellent suede-like artificial leather that solves these problems in a well-balanced manner and has improved whitening, wear, and pilling.

JP 2000-303367 A JP 2003-268680 A

  The object of the present invention is to have a high wear resistance even when used in a hard application field such as furniture, car seats, etc., where high durability performance is required for wear, and it is not effective. It is to provide a suede-like artificial leather having high durability performance with less whitening, wear and pilling in the process.

In order to solve the above-mentioned problems, the present inventors have conducted extensive studies on the change in the shape of the yarn during the wear process, and as a result, the ease of deformation in the cross-sectional direction of the yarn during the wear process greatly affects the whitening phenomenon. That is, it was found that the compression characteristics and viscoelastic characteristics in the cross-sectional direction of the ultrafine fibers used for the surface fiber layer greatly affect the whitening phenomenon, and in order to reduce the wear phenomenon and eliminate the pilling phenomenon, It has been found that there is an optimum region for the intrinsic viscosity of the ultrafine fibers used in the layer. The present invention has been completed based on these findings.
That is, the present invention is as follows.

  1. A suede-like artificial leather whose surface fiber layer is composed of polyethylene terephthalate ultrafine fibers composed of repeating units of ethylene terephthalate and is impregnated with a polyurethane resin and satisfies the following conditions (1) to (4) Suede-like artificial leather, characterized by

(1) The intrinsic viscosity of the polyethylene terephthalate ultrafine fiber is 0.57 or more and 0.63 or less.
(2) The fineness of the ultrafine fiber is 0.5 dtex or less.
(3) The tan δ _max value after treatment for 30 minutes under no tension in 130 ° C. hot water is 0.16 to 0.22 and the T _max value is 125 ° C. to 160 ° C. .
(4) The ultrafine fiber has a crystal integrity of 23% or more by wide-angle X-ray analysis.

2. 2. The suede-like artificial leather according to 1 above, wherein the ultrafine fibers constituting the surface fiber layer are made of polyethylene terephthalate having an ethylene terephthalate repeating unit of 80% or more.
3. The suede-like artificial leather according to 1 or 2 above, wherein the ultrafine fibers constituting the surface fiber layer have a boiling water shrinkage in the fiber axis direction of less than 25%.

4). The suede-like artificial leather according to any one of the above 1 to 3, wherein the polyurethane resin is an aqueous polyurethane and the content of the polyurethane resin in the artificial leather is 5 to 25 wt%.
5. The suede-like artificial leather according to any one of the above 1 to 3, wherein the polyurethane resin is an organic solvent-based polyurethane, and the content of the polyurethane resin in the artificial leather is 25 to 50 wt%.

6). The suede tone according to any one of 1 to 5 above, wherein the ultrafine fiber constituting the surface fiber layer has a primary yield stress of 0.16 mN / μm ² or less at the time of compressive deformation in the fiber cross-sectional direction. Artificial leather.
7). The suede-like artificial leather according to any one of 1 to 6 above, wherein the end point of wear resistance is 60000 or more, and the anti-pilling performance is 4 or more.

  Hereinafter, the present invention will be described in detail.

  In the present invention, the ultrafine fibers constituting the surface fiber layer are polyethylene terephthalate composed of ethylene terephthalate repeating units, and the ethylene terephthalate repeating units are preferably 80% or more, more preferably 90% or more, and still more preferably 95. %. Polyethylene terephthalate as described above can satisfy the whitening performance, abrasion resistance, and anti-pilling performance of artificial leather, and is preferable from the viewpoint of versatility and recyclability.

  In order to achieve both wear resistance and anti-pilling properties, the intrinsic viscosity of the ultrafine fiber greatly affects the wear resistance and anti-pilling properties of the artificial leather. I found that it was necessary. FIG. 1 shows the relationship between the intrinsic viscosity of an ultrafine fiber, wear resistance and anti-pilling properties.

  According to the knowledge of the present inventors, the wear resistance is improved in performance as the intrinsic viscosity increases. On the other hand, when the anti-pilling property is higher than a certain intrinsic viscosity, it is difficult for fibers to fall off due to wear, resulting in remaining pilling on the artificial leather surface. That is, when a certain intrinsic viscosity is exceeded, the wear resistance and the anti-pilling performance are in a contradictory relationship.

The reason for this is not clear, but as the intrinsic viscosity of the polymer increases, structural defects associated with the molecular end phenomenon of the polymer are reduced and durability is improved in the wear test. When the intrinsic viscosity is exceeded, it is considered that the fiber becomes stronger than the force applied in the process of the wear test and does not fall off and becomes pilling.
Therefore, in the present invention, in order to achieve both high wear resistance and anti-pilling properties, the intrinsic viscosity of polyethylene terephthalate in the ultrafine fibers constituting the surface fiber layer is 0.57 to 0.63.

The artificial leather of the present invention has a suede tone, and the fineness of the ultrafine fibers constituting the surface fiber layer needs to be 0.5 dtex or less, preferably 0.35 dtex or less in order to create an elegant surface property. It is. Furthermore, considering the robustness, durability, and soft feel of the surface with a high-class feeling, 0.04 to 0.2 dtex is the most preferable range.
If the fineness is less than 0.04 dtex and is too fine, when dyeing in a dark dyed area typified by black, the dye concentration at the time of dyeing tends to be very high, and the dyeing fastness tends to decrease, and the yarn Since it becomes too thin, light may be irregularly reflected and a dark color may not be sufficiently developed.

In the present invention, the ultrafine fiber has a tan δ _max value of 0, as shown in FIG. 2, among viscoelastic properties after 30 minutes of treatment in hot water at 130 ° C. without tension, assuming a dyeing process. .16 to 0.22 and a T _max value of 125 to 160 ° C., preferably a tan δ _max value of 0.165 to 0.20 and a T _max value of 130 to 155 ° C., more preferably The tan δ _max value is 0.170 to 0.20, and the T _max value is 135 to 155 ° C.

When the tan δ _max value is 0.16 to 0.22 and the T _max value is 125 to 160 ° C., the amorphous structure of the polyethylene terephthalate fiber has a large amount of amorphous material and is relatively dense. The primary yield stress at the time of compressive deformation in the cross-sectional direction is 0.16 mN / μm ² or less. On the other hand, when the tan δ _max value is less than 0.16, since the amorphous amount is small and the crystal region is large, the primary yield stress at the time of compressive deformation in the cross-sectional direction of the fiber exceeds 0.16 mN / μm ² and the wear evaluation In the endurance test, etc., once the fiber structure is broken like glass, it cannot be recovered, so the diffuse reflection of light due to fibrillation, the fiber is completely crushed and flattened, becomes a mirror, and shine is generated, In any case, it is considered that the degree of whitening, which is a phenomenon that the surface becomes white, increases.

Further, if the tan δ _max value exceeds 0.22, the amount of amorphous becomes excessive, so that the wear performance decreases, and if the T _max value exceeds 160 ° C., the tan δ _max value becomes less than 0.16. Can not satisfy the purpose and effect.

  In the present invention, the ultrafine fiber has a crystal perfection of 23% or more, preferably 25% or more after wide-angle X-ray analysis after 30 minutes of treatment in hot water at 130 ° C. under no tension. The crystal perfection in the crystal structure is a technique for knowing the state of the fiber structure. When the crystal perfection is less than 23%, it becomes close to the fiber structure of the undrawn yarn, and the mechanical performance tends to be lowered. There is a tendency for the abrasion resistance of leather to decrease.

  In the present invention, the ultrafine fiber preferably has a boiling water shrinkage in the fiber axis direction of less than 25%, more preferably less than 20%, and even more preferably less than 15%. When the boiling water shrinkage in the fiber axis direction is in the above range, there is little shrinkage of the fiber in the heat treatment process such as the dyeing process, the wear resistance is good, the surface has a soft texture, and excellent quality. Of artificial leather. In the case of semi-undrawn yarn (POY) in a region where the boiling water shrinkage exceeds 25%, the fiber shrinks in the process of applying heat such as dyeing, resulting in a decrease in molecular orientation in the fiber axis direction and disordered crystallization. Therefore, the strength tends to decrease and the wear resistance performance tends to decrease.

In the present invention, the ultrafine fiber preferably has a primary yield stress of 0.16 mN / μm ² or less at the time of compressive deformation in the cross-sectional direction of the fiber. This is because, as a result of intensive observation of the ultrafine fibers in the surface fiber layer during the wear test, (a) as the whitening progresses, first, a part of the fiber is deformed so as to be flattened, and (b) The degree of flatness and the number of deformed fibers increase, and the flattened fibers become fibrillated and cut and fall off. (C) Many fibers are flattened and flattened including fibrillated and fibrils. It turns out that it goes through the process.

  And as a result of changing the characteristics of the fiber and repeating the abrasion test, it was found that the fiber cross-section is more likely to be whitened as the fiber cross-section is more easily deformed. Therefore, assuming that the ease of deformation of the single yarn cross-section is due to the mechanical properties of the fiber cross-section, the results of an attempt to measure under various conditions showed that the primary yield stress during compression deformation in the fiber cross-section direction was below a certain value. The inventors obtained the knowledge that the cross-sectional deformation of the fiber is suppressed and the whitening resistance is further improved.

From the above findings, the primary yield stress during compression deformation in the cross direction of the fibers is preferably at 0.16mN / μm ² or less, more preferably 0.05~0.16mN / μm ^2, more preferably 0.07 to 0.16 mN / μm ² .

  The compressive deformation characteristic in the cross-sectional direction of this fiber is shown by the compressive stress curve in FIG. The primary yield stress at this time is a numerical value indicated by a dotted arrow in FIG. In the present invention, this numerical value is preferably equal to or less than a certain value, which means that it is easily deformed with respect to the force in the cross-sectional direction of the fiber, and is considered to be contrary to the above-mentioned observation result. However, fibers whose primary yield stress during compressive deformation in the fiber cross-sectional direction is less than a certain value are easily deformed by the force in the direction of compressing the fiber cross-section in the friction test, but durability until structural failure occurs. Since the deformation is easy to recover when the force is relaxed, the deformation of the cross section is considered to be small in the end.

On the other hand, when the primary yield stress at the time of compressive deformation in the cross-sectional direction of the fiber exceeds 0.16 mN / μm ² , it means that it is difficult to be deformed against the force in the cross-sectional direction of the fiber. However, in a long-time wear test, the internal microstructure is easily destroyed, so when the force is relaxed, the deformation does not recover, and eventually the cross-sectional deformation is considered to increase.

  In this way, at first glance, it seems to be a property contrary to the whitening resistance performance, but in the durability test by repeated compression such as a wear test, the durability until the fiber microstructure breaks against the compression in the fiber cross-sectional direction. Improvement is necessary, and it is considered that the primary yield stress at the time of compressive deformation in the cross-sectional direction of the fiber is equal to or less than a certain value leads to improvement of the whitening resistance.

The lower limit value of the primary yield stress at the time of compressive deformation in the cross-sectional direction of the fiber is, for example, a completely undrawn yarn or the like, and the case where most of the fiber is amorphous, preferably 0.05 mN / μm ² or more More preferably, it is 0.07 mN / μm ² or more.

  In the present invention, regarding the wear resistance performance, it is preferable that the end point of Martindale wear evaluation is 60000 times or more even in the region where the lightness (L *) is 30 or less in the suede-like artificial leather. It is preferable that the generation of pills on the surface after 30000 evaluations of Martindale wear is 1 to 2, more preferably less than 1, and the anti-pilling performance is preferably quaternary or higher.

  In the present invention, the ultrafine fibers constituting the surface fiber layer can be produced by a direct spinning method or a method of extracting sea components after once spinning sea-island fibers. In order to simplify the manufacturing process and reduce the environmental burden, etc., the direct spinning method is suitable, and the use of alkali-soluble polyesters and polystyrene, which are easy to produce ultrafine fibers, and polyvinyl alcohol that dissolves in hot water. It can also be produced by extracting and extracting ultrafine fibers from the sea-island fibers or split fibers. In addition, the sea-island fiber or the split fiber can be extracted in a subsequent process to form the ultra-fine fiber without using the ultra-fine fiber.

The suede-like artificial leather of the present invention is produced by raising a nonwoven fabric sheet, a woven fabric, and a knitted fabric.
As an example of a preferred production method, in order to reduce the environmental burden and simplify the production process, the ultrafine fiber obtained by the above-described direct spinning method is cut into short fibers, and this is dispersed in water. This is a technique for making a tangled body by making a sheet directly by the paper making method and three-dimensionally tangling this sheet by the hydroentanglement method.

  Furthermore, in addition to the papermaking method, not only ultrafine fibers obtained by direct spinning, but also ultrafine fibers extracted from sea-island fibers or split fiber may be cut into sheets by paper-making method. After cutting, it may be made into a sheet by a papermaking method, or the cut yarn may be calendered into a sheet.

Furthermore, in order to three-dimensionally interlace the ultrafine fibers and the fibers before extraction after forming into a sheet, not only the hydroentanglement method but also the needle punch method may be used.
That is, the above-described sheet forming method may use a calendar processing method, and is not limited to the papermaking method. Further, the entanglement method may be a entanglement method such as needle punching, and is not limited to the hydroentanglement method in the present invention.

  In the present invention, when a scrim that is a woven fabric or a knitted fabric is used for papermaking, a woven fabric such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, kevlar, and carbon fiber can be used. Although not particularly limited, most preferred is a polyethylene terephthalate fiber scrim having 80% or more of ethylene terephthalate repeating units because of general versatility.

  When the scrim is a woven fabric, high dimensional stability and strength are easily realized due to the characteristics of the woven fabric. As the yarn constituting the woven fabric, a processed yarn having no twist or a twist of 400 to 1200 T / m is suitably used, but an unprocessed fabric or the like may be used and is not particularly limited. In the woven fabric, a processed yarn may be used for either the weft or the warp and may be arbitrarily combined depending on the application.

The fineness of the yarn used for the scrim is preferably in the range of 30 to 500 dtex, more preferably in the range of 55 to 220 dtex, and may be selected according to the required strength.
When the scrim is a knitted fabric, a single knit knitted fabric of 22 to 28 gauge is preferable.

  In the present invention, since the ultrafine fiber layer of the surface layer is characterized, the surface fiber layer may be composed of the ultrafine fiber. Other fibers, woven fabrics, knitted fabrics, etc. can be used for the other layers, and a multi-layer structure may be formed, but a three-layer structure consisting of a surface layer, a woven / knitted layer, and a back layer is an artificial leather. As such, it is easy to obtain dimensional stability, strength, and the like, and the quality is also favorable. In a multilayer structure of more than that, not only the manufacturing process becomes complicated, but the thickness of each layer becomes thin and the durability is lowered, and the fibers of each layer are mixed with each other and the quality is liable to deteriorate.

  In the present invention, an artificial leather base fabric (hereinafter referred to as a non-woven fabric) is impregnated with a polyurethane resin in order to enhance the binding of fibers, prevent the fibers from falling off, or impart resilience to the artificial leather itself.

  When the polyurethane resin is an aqueous polyurethane, the content in the artificial leather is preferably 5 to 25 wt%, and when it has a scrim, it is preferably 6 to 20 wt%, more preferably 7 to 15 wt%. In the case of organic solvent-based polyurethane, the content in the artificial leather is preferably 25 to 50 wt%. When the content of the polyurethane resin is in the above range, the texture of the artificial leather is flexible, the binding between the fibers is sufficiently high, the fibers do not fall off, and the durability is good.

  The type of the polyurethane resin may be either an aqueous polyurethane resin or an organic solvent-based urethane resin, but an aqueous polyurethane resin is preferred from the viewpoint of environmental load and recovery of the organic solvent.

Examples of the components of the aqueous polyurethane resin include the following.
Examples of the polyol component include polyester diols such as polyethylene adipate glycol, polyether glycols such as polyethylene glycol and polytetramethylene glycol, and polycarbonate diols. Examples of the isocyanate component include aromatic isocyanates such as diphenylmethane-4,4-diisocyanate, alicyclic isocyanates such as dicyclohexylmethane-4,4-diisocyanate, and aliphatic diisocyanates such as hexamethylene diisocyanate. Examples of the chain extender include glycols such as ethylene glycol, diamines such as ethylenediamine and 4,4-diaminodiphenylmethane, and the like.

The above-mentioned various components can be appropriately combined to form a raw material polyurethane. In particular, a non-yellowing polyurethane composed of a polycarbonate diol which is not easily yellowed is preferable from the viewpoint of product quality stability.
In addition, polyurethane emulsion or polymer chain with other components such as hindered amines and hindered phenols incorporated such as heat-resistant oxidizers will not affect the degradation of polyurethane resin performance or dropout of polyurethane during dyeing. If there is no problem, it may be used as a polyurethane resin.

The raw fabric of the suede-like artificial leather of the present invention is produced by dyeing with a flow dyeing machine and reduction cleaning.
Dyeing by a liquid dyeing machine is most preferable from the viewpoint of improving the product power due to the effect of pulling out brushed hair by a jet nozzle and the effect of soft cloth, and productivity.

  For the reduction cleaning, a general alkali reduction formulation such as thiourea dioxide and sodium hydroxide, or sodium hydrosulfite and sodium carbonate can be applied. It is preferable to perform a reduction treatment at an appropriate concentration setting so that various fastnesses such as washing, dry cleaning, and wet friction fastness do not decrease. In general, reduction cleaning is performed using thiourea dioxide and sodium hydroxide at a concentration of 1 to 8 g / liter according to the dye concentration.

  Since the suede-like artificial leather of the present invention can maintain high durability and quality even under harsh usage environments, such as furniture and car seats that require high durability against friction. Also in the field of application, high wear resistance can be exhibited with less whitening and wear during the wear process and less pilling.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further, this invention is not limited to these. Measurement methods, evaluation methods, etc. are as follows.

(1) Primary yield stress at the time of compressive deformation in the fiber cross-sectional direction Using a Shimadzu dynamic ultra-micro hardness meter DUH-W201S manufactured by Shimadzu Corporation, one single yarn is taken out from the ultrafine fiber yarn to be measured and placed on the Si wafer. After being set aside and placed on the measurement stage together with the Si wafer, the stress at the time of compressive deformation in the cross-sectional direction of the ultrafine fiber was measured with a flat indenter having a diameter of 20 μm at a load speed of 0.284 mN / sec.
As a result of the measurement, the primary yield stress was determined from the compression stress-compression ratio chart as shown in FIG.

(2) Intrinsic Viscosity Intrinsic viscosity (IV35 ° C) is obtained by dissolving the sample at 35 ° C so as to have a concentration of 1 g / dl with respect to orthochlorophenol, and calculating the reduced viscosity measured by an Ubbelohde viscometer by the following formula It is defined as a value converted to an intrinsic viscosity at ° C.
IV35 ° C. = ((1 + ηsp / c) ^0.5 −1) /0.5

(3) Viscoelastic properties (tan δ _max and T _max )
Using a MODEL DDV-01FP manufactured by Orientec Co., Ltd., a sample length of 2.00 cm, a measurement frequency of 110 Hz, and a heating rate of 5 ° C. The loss elastic modulus and storage elastic modulus at each temperature are obtained under the conditions of / min, the dynamic elastic loss tangent is calculated from (loss elastic modulus / storage elastic modulus), and the peak is obtained from the dynamic elastic loss tangent temperature curve. The top dynamic elastic loss tangent was tan δ _max and the temperature was T _max .

(4) Crystal perfection Using the R-AXISIIC manufactured by Rigaku Corporation as the wide-angle X-ray analyzer, the sample after being treated for 30 minutes under no tension in hot water at 130 ° C., the sample is about 6000 dtex. After bundling to a certain extent, a tube method with a tube voltage of 40 kV and a tube current of 100 mA is applied with a measurement method by transmission X-ray diffraction, the camera length is 98.2 mm, an imaging plate IP is used as a detector, A diffraction intensity curve was measured in a measurement range of 5 to 45 degrees at the bending angle 2θ.

Next, as shown in FIG. 4, the baseline correction is performed from the diffraction intensity curves of 2θ = 5 degrees and 38 degrees, and the diffraction peak intensity (A) of the diffraction peak (100) plane drawn at 2θ = 26 degrees is obtained. Then, the diffraction intensity (B) at a position that is a valley between the diffraction peaks of 2θ = 26 degrees and 22 degrees was determined, and crystal perfection was determined by the following formula.
Crystal perfection (%) = [1- (B / A)] × 100

(5) Whitening resistance Whitening resistance conformed to JIS-L-1096 (E method: Martindale method). In this test, lightness before test, lightness after wear 3000 times with n = 10 (press light load) (lightness after test), lightness (L *) measured using Minolta CM3500D, lightness before and after wear Thus, the brightness difference was set to an absolute value | ΔL |, and the whitening resistance was evaluated according to the following criteria.
| ΔL | = | (Brightness before test) − (Brightness after test) |
○: | ΔL | <9
Δ: 9 ≦ | ΔL | ≦ 10
×: 10 <| ΔL |

(6) Abrasion resistance performance According to JIS-L-1096 (E method: Martindale method). In this test, after a wear test at a pressure load of 12 kPa and n = 10, the number of exposures or holes in two or more scrim surfaces in an area of 2 mm or more in diameter was used as an end point, and evaluation was performed according to the following criteria.
○: Endpoint is 60000 or more Δ: Endpoint is 55000 or more ×: Endpoint is less than 55000

(7) Pilling performance According to JIS-L-1096 (E method: Martindale method), the average value of the number of pills generated on the surface was obtained after 30,000 times wear at n = 10 at a pressure load of 12 kPa, and The pilling property was evaluated based on the standard.
Grade 5: Number of pills = 0
4th class: Number of pills = 1-2
Grade 3: Number of pills = 3-10
Second grade: Number of pills = 11-20
First grade: Number of pills> 20

(8) Texture The surface quality of the artificial leather was evaluated by visual and tactile sensory tests according to the following criteria.
○: The texture is good △: The texture is about the same level ×: The texture is bad

(9) Comprehensive evaluation Comprehensive evaluation was evaluated based on the results of whitening resistance performance, abrasion resistance performance, pilling properties, and texture.
○: All ○
△: 1 △
N: Other than that

[Examples 1 to 4, Comparative Example 1]
In Examples 1 to 4, polyethylene terephthalate having an intrinsic viscosity of 0.63 (Examples 1, 2, 4) and 0.68 (Example 3) before spinning was used, and the spinning speed was 700 by direct spinning. Polyester ultrafine fibers shown in Table 1 were produced under the conditions of ˜1000 m / min and a draw ratio of 1.8 to 2.0 times. The obtained fiber had a single fiber fineness of 0.15 dtex and a breaking elongation of 40 to 55%.
In Comparative Example 1, polyester terephthalate as shown in Table 1 was used under the conditions of a spinning speed of 700 m / min and a draw ratio of 2.5 times by a direct spinning method using polyethylene terephthalate having an intrinsic viscosity of 0.69 before spinning. A fiber was produced. The obtained fiber had a single fiber fineness of 0.15 dtex and a breaking elongation of 25%.

The polyester microfibers obtained above were cut to a length of 5 mm, and then dispersed in water to prepare a papermaking slurry for the surface layer and the back layer. Using the obtained slurry, the surface weight per unit area was 100 g / m ² , the back layer per unit area was 50 g / m ^2, and a polyester fiber processed yarn of 167 dtex / 48f was used in the middle, and a twisted yarn of 800 T / m was used. A gauze-like woven fabric of 2.54 cm and weft 62 / 2.54 cm was inserted as a scrim, and a three-layer laminated nonwoven fabric sheet was produced by continuous papermaking. Next, a three-dimensional entangled nonwoven fabric was obtained by jetting high-speed water flow. The high-speed water jet was jetted from the surface layer at a pressure of 4.0 MPa and from the back layer at a pressure of 3.0 MPa using a straight flow jet nozzle having a hole diameter of 0.1 mm. Subsequently, it dried with the pin tenter and manufactured the sheet-like material with a basis weight of 200 g / m < ² >.

The surface layer of this sheet-like material is buffed with # 400 sandpaper, and then impregnated with a solution obtained by adding 3 wt% of sodium sulfate to a 9 wt% polyether-based aqueous polyurethane so that the adhesion rate becomes 12 wt%. Then, it was heated and dried with a pin tenter dryer for 3 minutes to produce an artificial leather raw fabric.
The obtained artificial leather raw fabric is dyed with a blue disperse dye (BlueFBL: manufactured by Sumitomo Chemical Co., Ltd.) at 130 ° C. for 30 minutes with a liquid dyeing machine, subjected to reduction washing with alkali, and has a lightness of 28 suede-like artificial leather. Got the product.

The obtained suede-like artificial leather product was measured for whitening resistance, abrasion resistance, and anti-pilling at 30000 times by Martindale abrasion. The results are shown in Table 1. As can be seen from Table 1, Examples 1 to 4 were improved in whitening resistance, abrasion resistance and anti-pilling performance, had excellent durability and a good texture as artificial leather. On the other hand, in Comparative Example 1, the value of tan δ _max was small, and the primary yield stress value at the time of compressive deformation in the fiber cross-sectional direction was high, and the whitening resistance performance was poor.

[Comparative Example 2]
Polyester in the same manner as in Example 1 except that after spinning and winding up, the draw ratio in the drawing step was 2.7 times, and heat setting was performed for 5 minutes under tension in a heat tube at 180 ° C. A fiber was produced. The obtained fibers were as shown in Table 1, and had a single fiber fineness of 0.15 dtex and a breaking elongation of 15%.

Using the obtained fiber, an artificial leather raw fabric was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1. As can be seen from Table 1, the value of tan δ _max is small, and the primary yield stress value at the time of compressive deformation in the fiber cross-sectional direction is high, resulting in poor whitening resistance. The performance and quality were not reached.

[Comparative Example 3]
Polyethylene terephthalate with a polymer intrinsic viscosity of 0.63 before spinning is spun at a spinning speed of 2000 m / min by a direct spinning method under conditions where the molten polymer is cooled relatively quickly, and the draw ratio is 1.25 times. As a polyester fiber. The obtained fibers were as shown in Table 1, the single fiber fineness was 0.15 dtex, and the elongation at break was 60%.

  Using the obtained fiber, an artificial leather raw fabric was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1. As can be seen from Table 1, although the primary yield stress value at the time of compressive deformation in the fiber cross-sectional direction is low, the crystal perfection is as low as 21% and the fiber structure is close to the undrawn yarn, so the wear resistance performance is poor. The durability performance of the artificial leather intended in the invention was not expressed.

[Comparative Examples 4 and 5]
Using polyethylene terephthalate having a polymer intrinsic viscosity of 0.68 before spinning and spinning at a spinning speed of 2500 m / min (Comparative Example 4) and 1900 m / min (Comparative Example 5) by the direct spinning method. Polyester fibers were produced. The obtained fibers were as shown in Table 1. The single fiber fineness was 0.15 dtex, and the breaking elongation was 100% (Comparative Example 4) and 140% (Comparative Example 5).

  Using the obtained fibers, artificial leather raw fabrics were produced and evaluated in the same manner as in Example 1. The results are shown in Table 1. As can be seen from Table 1, in Comparative Example 4 and Comparative Example 5, although the primary yield stress value at the time of compressive deformation in the fiber cross-sectional direction is low, the crystal integrity is low, the boiling water shrinkage rate is high, and the wear resistance is high. In addition to poor performance, the quality was also poor, and the durability and quality of the artificial leather intended in the present invention were not reached.

[Examples 5 and 6, Comparative Examples 6 to 9]
A polyester ultrafine fiber was produced in the same manner as in Example 1 except that a polymer having an intrinsic viscosity of 0.52 to 0.74 was used. The obtained ultrafine fibers were as shown in Table 2, and the single fiber fineness was 0.15 dtex.

  Using the obtained ultrafine fibers, an artificial leather raw fabric was prepared and dyed in the same manner as in Example 1. The obtained artificial leather fabric was measured for whitening resistance, abrasion resistance, and anti-pilling at 30000 times by Martindale abrasion. The results are shown in Table 2. As can be seen from Table 2, Examples 5 and 6 had excellent durability with improved whitening resistance, abrasion resistance and anti-pilling performance, and had a good texture as artificial leather.

  On the other hand, Comparative Example 6 and Comparative Example 7 had low intrinsic viscosity of the ultrafine fibers, poor abrasion resistance, and low whitening performance. Since Comparative Example 8 and Comparative Example 9 have a high intrinsic viscosity of the ultrafine fiber, the whitening performance and the wear resistance are excellent, but pilling occurs and the anti-pilling performance is greatly reduced. No artificial leather to be obtained.

[Examples 7 and 8]
For the sea component, polyethylene terephthalate obtained by copolymerizing 10% of polyethylene glycol having a molecular weight of 4000 was used as a polyester copolymer that is easily reduced in alkali. On the other hand, regular type polyethylene terephthalate that was not copolymerized was used for the island component. These two kinds of polymers were spun with 35% sea component and 65% island component, and then heat-drawn, and then the sea component was eluted with 5 wt% NaOH aqueous solution at 80 ° C. to obtain ultrafine fibers. The obtained ultrafine fibers were as shown in Table 3, and the single fiber fineness was 0.10 dtex (Example 7) and 0.06 dtex (Example 8).

  Using the obtained ultrafine fibers, an artificial leather raw fabric was prepared and dyed in the same manner as in Example 1. The obtained artificial leather fabric was measured for whitening resistance, abrasion resistance, and anti-pilling at 30000 times by Martindale abrasion. The results are shown in Table 3. As can be seen from Table 3, Example 7 and Example 8 had improved whitening resistance, abrasion resistance and anti-pilling performance, had excellent durability, and had a good texture as artificial leather.

[Example 9]
Polyethylene terephthalate obtained by copolymerizing 10 wt% of polyethylene glycol having a molecular weight of 4000 was used as the polyester copolymer that is easily reduced in alkali. On the other hand, non-copolymerized regular type polyethylene terephthalate was used as the polymer that is difficult to reduce the alkali. These two types of polymers were spun and stretched at a copolymer polymer: regular type polymer ratio of 20:80 so as to be divided into 6 split fibers, followed by 80 ° C., 5 wt% NaOH aqueous solution. The copolymer component was eluted to obtain ultrafine fibers. The obtained ultrafine fibers were as shown in Table 3, and the single fiber fineness was 0.13 dtex.

  Using the obtained ultrafine fibers, an artificial leather raw fabric was prepared and dyed in the same manner as in Example 1. The obtained artificial leather fabric was measured for whitening resistance, abrasion resistance, and anti-pilling at 30000 times by Martindale abrasion. The results are shown in Table 3. As can be seen from Table 3, the whitening resistance, abrasion resistance, and anti-pilling performance were improved, and it had excellent durability and a good texture as an artificial leather.

[Examples 10 and 11]
In the same production method as in Example 7 and Example 9, the hot-drawn yarn after spinning was cut into 50 mm without reducing the alkali, and then passed through a card cross wrapper, and a sheet-like material having a basis weight of 180 g / m ² Manufactured. This sheet-like material was needle punched to obtain a three-dimensional entangled nonwoven fabric.

The obtained three-dimensional entangled nonwoven fabric was treated in hot air at 150 ° C., and further pressed with a roll heated to 85 ° C. to form a 210 g / m ² sheet, which was subsequently immersed in a polyvinyl alcohol solution, It dried after adjusting so that it might become 20 wt%. Subsequently, it was impregnated with an ester / ether polyurethane solution so as to have an adhesion rate of 30 wt%, wet coagulated, desolvated in hot water and dried.

  Next, this sheet is immersed in an NaOH aqueous solution of 5 wt% at 80 ° C. to elute the copolymer component of the surface yarn, washed with water, dried, sliced to give surface smoothness, and this sheet Was buffed with # 300 sandpaper to obtain an artificial leather raw fabric. The obtained artificial leather fabric is dyed with a blue disperse dye (Blue FBL, manufactured by Sumitomo Chemical Co., Ltd.) at 130 ° C. for 30 minutes and subjected to reduction washing with alkali to produce a suede-like artificial leather product with a brightness of 26 Obtained.

  This product was measured for whitening resistance, abrasion resistance, and anti-pilling at 30000 times by Martindale abrasion. The results are shown in Table 3. As can be seen from Table 3, Example 10 and Example 11 were improved in whitening resistance, abrasion resistance, and anti-pilling performance, had excellent durability, and had a good texture as artificial leather.

[Examples 12 to 15]
Using the sheet completed up to the buffing process in the same manner as in Example 1, the polyether-based aqueous polyurethane was impregnated with the artificial leather so that the adhesion rate was 5 to 25 wt%, and was heat-dried for 3 minutes with a pin tenter dryer. An artificial leather raw fabric was prepared. The obtained artificial leather fabric was dyed in the same manner as in Example 1 to obtain a suede-like artificial leather product with a lightness of 29.

  The obtained artificial leather product was measured for whitening resistance, abrasion resistance, and anti-pilling at 30000 times by Martindale abrasion. The results are shown in Table 4. As can be seen from Table 4, Examples 12 to 15 were improved in whitening resistance, abrasion resistance and anti-pilling performance, had excellent durability, and had a good texture as artificial leather.

[Examples 16 to 18]
Using the same ultrafine fiber as in Example 7, using the sheet completed up to the buffing process in the same manner as in Example 1, the ester / ether polyurethane solution was impregnated with an artificial leather so that the adhesion rate was 25 to 45 wt%. Thereafter, it was wet-coagulated, solvent-removed in hot water and dried to produce an artificial leather raw fabric. The obtained raw fabric was dyed in the same manner as in Example 1 to obtain a suede-like artificial leather product having a lightness of 28.

  The obtained artificial leather product was measured for whitening resistance, abrasion resistance, and anti-pilling at 30000 times by Martindale abrasion. The results are shown in Table 4. As can be seen from Table 4, Examples 16 to 18 were improved in whitening resistance, abrasion resistance and anti-pilling performance, had excellent durability, and had a good texture as artificial leather.

  The suede-like artificial leather of the present invention has high durability and is suitable for car seats and furniture.

It is a figure which shows the relationship in the present invention, showing the relationship between the intrinsic viscosity of the ultrafine fiber, the wear resistance and the anti-pilling property. It is a figure which shows the viscoelastic characteristic range in this invention. It is a figure which shows an example of the relationship between the compression rate at the time of compression of a fiber cross section direction, and the primary yield stress at the time of compression. It is a figure which shows an example of an X-ray diffraction chart.

Claims (7)

A suede-like artificial leather whose surface fiber layer is composed of polyethylene terephthalate ultrafine fibers composed of repeating units of ethylene terephthalate and is impregnated with a polyurethane resin and satisfies the following conditions (1) to (4) Suede-like artificial leather, characterized by
(1) The intrinsic viscosity of the polyethylene terephthalate ultrafine fiber is 0.57 or more and 0.63 or less.
(2) The fineness of the ultrafine fiber is 0.5 dtex or less.
(3) The tan δ _max value after treatment for 30 minutes under no tension in 130 ° C. hot water is 0.16 to 0.22 and the T _max value is 125 ° C. to 160 ° C. .
(4) The ultrafine fiber has a crystal integrity of 23% or more by wide-angle X-ray analysis.   The suede-like artificial leather according to claim 1, wherein the ultrafine fibers constituting the surface fiber layer are made of polyethylene terephthalate having an ethylene terephthalate repeating unit of 80% or more.   The suede-like artificial leather according to claim 1 or 2, wherein the ultrafine fibers constituting the surface fiber layer have a boiling water shrinkage in the fiber axis direction of less than 25%.   The suede-like artificial leather according to any one of claims 1 to 3, wherein the polyurethane resin is an aqueous polyurethane, and the content of the polyurethane resin in the artificial leather is 5 to 25 wt%.   The suede-like artificial leather according to any one of claims 1 to 3, wherein the polyurethane resin is an organic solvent-based polyurethane, and the content of the polyurethane resin in the artificial leather is 25 to 50 wt%. 6. The suede according to claim 1, wherein the ultrafine fiber constituting the surface fiber layer has a primary yield stress of 0.16 mN / [mu] m < ² > or less at the time of compressive deformation in the fiber cross-sectional direction. Artificial leather. The suede-like artificial leather according to any one of claims 1 to 6, wherein the end point of the wear resistance is 60000 or more and the anti-pilling performance is 4 or more.

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