JP2017222962A - Artificial leather - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial leather rich in durability, having a surface so smooth providing good feeling, and appropriate for a wear fabric, a chair upholstery, and a vehicle interior material.SOLUTION: A depressed hole 24 having an inner diameter (d) of not less than 0.3 mm and not greater than 2 mm is formed on the surface of an artificial leather constituted by applying a thermoplastic resin 13 to a fabric 12 composed of a thermoplastic synthetic fiber 11. A peripheral edge 16 of the depressed hole 24 and an inner wall surface 18 of the inside are composed of a heat-molten mixture 15 of the thermoplastic synthetic fiber 11 and the thermoplastic resin 13. The peripheral edge 16 of the depressed hole 24 is on a position hollowed from the surface of the artificial leather. The inner diameter (d) of the depressed hole 24 is gradually narrowed toward the inside 19 of the depressed hole 24 from the peripheral edge 16 of the surface of the artificial leather. It is preferable that a minimum inner diameter (d) of the depressed hole 24 is less than 1 mm. A pattern can be stippled with the depressed holes 24 on the surface of the artificial leather. The depressed hole 24 may be processed to be an open hole 14 by heat-melting to open a hole bottom 25 thereof.SELECTED DRAWING: Figure 6

Description

  The present invention relates to artificial leather excellent in breathability, and more particularly to artificial leather suitable for clothing fabrics, chair upholstery, and vehicle interior materials that do not give a feeling of stuffiness during use.

  As a method for imparting air permeability to artificial leather, a heat drilling method for piercing a heated metal needle (for example, see Patent Document 1), an embossing method for causing a resin film to crack through an embossing roll (for example, Patent Document 2,) 3), a stagnation processing method (for example, see Patent Document 4) for generating a crack by stagnation processing, a foreign material extraction method (for example, see Patent Document 5) for extracting soluble foreign matter mixed in the resin film, and artificial leather A solvent coating method (for example, refer to Patent Document 6) for applying a solvent to a porous surface layer to open a porous film, and a punching method for performing a punching process (for example, refer to Patent Document 7) are known.

Japanese Patent Publication No. 55-45670 (Japanese Patent Laid-Open No. 54-138102) Japanese Utility Model Publication No.59-031756 (Japanese Utility Model Publication No.57-180791) JP-B-02-002993 (JP 59-199874) Japanese Patent No. 4405834 (Japanese Patent Laid-Open No. 2005-264371) Japanese Examined Patent Publication No. 54-034029 (Japanese Patent Laid-Open No. 48-007957) Japanese Patent No. 4778864 (Japanese Patent Laid-Open No. 2008-057064) Japanese Patent No. 5683353 (JP 2012-207352)

  In the hot drilling method, the hot melt is fused to the heated metal needle during hot perforation (heat insertion), and the insertion resistance of the heated metal needle received from the artificial leather is increased by the hot melt, and the through holes are evenly drilled. It becomes difficult to install, and the hot melt is transferred from the heated metal needle and the artificial leather is easily contaminated.

  In the embossing method, it is difficult to ensure the required air permeability because the cracks are fine, and the embossed pattern dominates the appearance, so that a smooth plain artificial leather cannot be obtained.

  In the stagnation processing method, it is difficult to ensure the required air permeability due to fine cracks, and small wrinkles are generated in the resin film, and silver-made artificial leather cannot be obtained.

  In the foreign matter extraction method, the physical properties of the resin film are impaired by the mixed soluble foreign matter, and artificial leather excellent in durability cannot be obtained.

  In the solvent coating method, the generated aperture is as small as 3 to 159 μm, and even if moisture permeability is ensured, it does not provide breathability to the extent that it does not give a sense of stuffiness. It is not durable because it is clogged, and the solvent to be used is an organic solvent such as dimethylformamide, tetrahydrofuran, dioxane and the like.

  In the punching method, the peripheral edge of the through hole is easily unraveled, and durability is a problem.

  Therefore, an object of the present invention is to provide an artificial leather that is rich in durability, has a smooth surface, has a good touch, has excellent breathability, and is suitable for clothing fabrics, chair upholstery, and vehicle interior materials.

  The artificial leather according to the present invention has (1) an inner diameter (d) of not less than 0.3 mm and not more than 2 mm on the surface of the artificial leather formed by applying the thermoplastic resin 13 to the fabric 12 comprising the thermoplastic synthetic fiber 11. The recessed hole 24 is formed, and (2) the peripheral edge 16 of the recessed hole 24 and the inner inner wall surface 18 are constituted by the hot melt 15 of the thermoplastic synthetic fiber 11 and the thermoplastic resin 13 ( 3) The peripheral edge 16 of the depressed hole 24 is in a position recessed from the surface of the artificial leather. (4) The inner diameter (d) of the depressed hole 24 is determined from the peripheral diameter (D) at the peripheral edge 16 of the artificial leather surface. The first feature is that the width gradually narrows toward the inside 19 of the recessed hole 24.

  The second feature of the artificial leather according to the present invention is that, in addition to the first feature, the recessed hole 24 is a through hole 14 penetrating the front and back of the artificial leather.

  A third feature of the artificial leather according to the present invention is that, in addition to any of the first and second features, the fabric 12 is a thermoplastic synthetic fiber multifilament yarn and the course cage (h) is 2 mm or less. (K) is a knitted fabric knitted to 2 mm or less.

  A fourth feature of the artificial leather according to the present invention is that, in addition to any of the first, second and third features, the fabric 12 is a nonwoven fabric containing 10 to 30% by mass of a polyurethane resin. .

The fifth feature of the artificial leather according to the present invention is that, in addition to any of the first, second, third, and fourth features, the artificial leather dent forming layer in which the recessed hole 24 is formed. The total mass (Q) of the dent forming layer shown as the sum of the mass of the thermoplastic synthetic fiber 11 and the mass of the thermoplastic resin 13 is 700 g / m ² or less.

  The sixth feature of the artificial leather according to the present invention is that, in addition to any of the first, second, third, fourth and fifth features, a pattern is pointed on the surface by the depression hole 24. It is in.

  The seventh feature of the artificial leather according to the present invention is that, in addition to any one of the first, second, third, fourth, fifth and sixth features, the minimum inner diameter ( d) is less than 1 mm.

The real thickness of the artificial leather is a value obtained by dividing the basis weight (Mg / m ² ), which is the mass per unit area of the artificial leather, by the density (ρg / cm ³ ) derived from the specific gravity (ρ) of the artificial leather. (Mg / m ² ÷ ρg / cm ³ = M / ρμm) The specific gravity of polyester, which is a raw material for artificial leather, is 1.38, the density is 1.38 g / cm ³ , the specific gravity of the polyacrylate is 1.15, the density is 1.15 g / cm ³ , and the specific gravity of the acrylate copolymer 1.28, density 1.28 g / cm ³ , polyamide (nylon) specific gravity 1.14, density 1.14 g / cm ³ , vinylon specific gravity 1.30, density 1.30 g / cm ³ The specific gravity of polyvinyl chloride is 1.39 and the density is 1.39 g / cm ^3. The specific gravity (ρ) of these synthetic fibers and synthetic resins is generally around 1.3 and the density is 1.3 g / cm ³ . is there. Therefore, the real thickness of the artificial leather having a basis weight (M) of 700 g / m ² is generally 538 μm.
Here, the “substantial thickness of the artificial leather” means the thickness of the raw material in a state that does not include the internal voids composed of the raw material synthetic fiber and the raw material synthetic resin excluding the internal voids of the artificial leather.
The characteristics of the artificial leather according to the present invention can be defined by the “substantial thickness of the artificial leather” for the following reason.

That is, when the artificial leather having a basis weight (M) of 700 g / m ² is heated, and the circular through hole 14 having an internal diameter (d) of 2 mm is formed as the heating mark, the mass of the hot melt generated is (D) is equal to the mass of a 2 mm diameter circular punched piece generated by punching a 2 mm through hole. The area of the circular punched piece with a diameter of 2 mm is a circular area with a radius of 1 mm, which is 0.0314 cm ² . The volume of the hot melt corresponds to the volume of a circular punched piece with a diameter of 2 mm. The volume is 0.0314 cm ² of the circular punched piece with a radius of 1 mm and the real thickness of artificial leather is 538 μm (= 0.0538 cm). Product (1.193 mm) ³ (≈0.00168932 cm ³ ).

That is, the total mass (Q) of the depression forming layer of the artificial leather to which the present invention is applied is 700 g / m ² , and the maximum diameter of the recessed hole and the through hole formed in the artificial leather to which the present invention is applied is 2 mm. Therefore, the hot melt generated in the artificial leather to which the present invention is applied has a shape equal to a cube having a dimension of 1.193 mm (≈1.2 mm). If the total mass (Q) of the dent forming layer is 700 g / m ² , the substantial thickness is 538 μm (= 0.538 mm), and the recessed hole or the through hole has a cylindrical shape with a maximum diameter of 2 mm, the height is 538 μm (= 0) .538 mm) and a cylindrical shape with a diameter of 2 mm (tmm) is 0.6 mm, and the cylindrical shape has a ring shape with a thickness of about one third of the diameter. Even if the wall 18 is touched, it does not give a sense of incongruity.

  Whether the depressed hole 24 and the through hole 14 affect the touch feeling of the artificial leather depends on whether the hot melt 15 constituting the depressed hole 24 or the through hole 14 is a thermoplastic synthetic fiber that is a raw material of the artificial leather. 11 and the thermoplastic resin 13, and the volume of the hot melt 15 is not due to the thickness or texture of the artificial leather including the internal voids as described above, but the depression in which the recessed holes 24 and the through holes 14 are formed. It is defined by the total mass (Q) obtained by adding the masses of the thermoplastic synthetic fiber 11 and the thermoplastic resin 13 constituting the forming layer. Therefore, the feature of the artificial leather of the present invention can be defined by the “substantial thickness” of the recess forming layer that is formed of the raw material synthetic fiber and the raw material synthetic resin and in which the recessed hole 24 and the through hole 14 are formed.

  In the artificial leather in which the through-holes 14 are formed, the thickness of the depression forming layer is the actual thickness of the artificial leather, but in the artificial leather in which the depression holes 24 are formed instead of the through-holes 14, the depression-forming layer The substantial thickness is a part of the total thickness (t) of the artificial leather, and is calculated as a ratio (t / T) between the total apparent thickness (T) and the apparent thickness (t) of the depression forming layer ( FIG. 6).

Similarly, the total mass (Q) of the artificial leather indentation layer in which the depressions 24 are formed is the total weight (M) of the entire artificial leather, the apparent thickness (T) of the entire artificial leather, and the appearance of the indentation layer. It is calculated as the product (M × t / T) with the ratio (t / T) to the thickness (t) of the film (FIG. 6).
This is because the texture of the artificial leather in which the depressed hole 24 is formed is lower than the bottom (25) of the depressed hole 24 and is not formed in the thermoplastic synthetic fiber or thermoplastic resin in the lower layer that does not constitute the hot melt 15. Because it is not influenced.

If the inner diameter (d) of the depressed hole or the through hole is less than 1 mm, the volume of the hot melt becomes finer and an artificial leather friendly to the skin can be obtained.
That is, as described above, the substantial thickness of the depression forming layer of the depression 24 of the artificial leather having a total mass (Q) of 700 g / m ² is generally 538 μm. The area of the circular punched piece having a diameter of 1 mm is a circular area having a radius of 0.5 mm, which is 0.0078 cm ² . The volume of the hot melt in this case corresponds to the volume of a circular punched piece having a diameter of 1 mm, and the volume is the area (0.0078 cm ² ) of the circular punched piece having a radius of 05 mm and the real thickness (0. 0538 cm) (0.74 mm) ³ and further smaller. Therefore, even if it touches the depression wall of the artificial leather of the present invention or the inner wall surface 18 of the through hole, it does not give a sense of incongruity.

In addition, in the artificial leather of the present invention, the peripheral edge 16 of the recessed hole 24 and the through hole 14 is in a position recessed from the surface of the artificial leather, and its internal diameter (d) is the peripheral diameter (D) at the peripheral edge 16. Since it gradually narrows toward the inside 19 of the recessed hole 24 and the through-hole 14, the skin does not directly touch the hot melt 15 constituting the inside of the recessed hole 24 and the through-hole 14, and the surface is smooth and soft. It is easy to breathe and provides artificial leather suitable for clothing fabrics, chair upholstery, and vehicle interior materials.
Further, in order to make the hot melt 15 minute, the total mass (Q) of the dent forming layer is reduced to 600 g / m ² or less, more preferably 600 g / m ² or less, and the artificial leather has a substantial thickness of generally 460 μm or less. To be.

  The thermoplastic synthetic fiber 11 and the thermoplastic resin 13 constituting the artificial leather of the present invention are cooled and hardened in the recessed holes 24 and the through holes 14 to cure the hot melt 15 constituting the peripheral edges 16 and 17 and the inner wall surface 18. In addition, since the eyelids are firmly joined as if they were bound together with eyelets, the thermoplastic synthetic fiber 11 and the thermoplastic resin 13 are not unraveled in the recessed holes 24 and the through holes 14, and an artificial leather excellent in durability can be obtained. can get.

  According to the present invention, artificial leather that is excellent in durability, rich in elasticity, soft, flexible, and soft to the touch, well adapted to the skin as a clothing fabric, and well adapted to curved surfaces as a chair upholstery or vehicle interior material. Is obtained. That is, any fabric of woven fabric, knitted fabric and non-woven fabric can be used as the base material of the artificial leather as long as it is made of the thermoplastic synthetic fiber 11.

In the knitted fabric, the needle loop surface and the sinker loop surface are front and back. In the sinker loop surface, the sinker loop is an uneven surface raised in each course cage (h) in the knitting (course) direction. The knitting yarn connecting the sinker loop and the needle loop becomes a smooth surface in which chain stitches are formed side by side like a loop pile continuing in the knitting (course) direction.
For this reason, by laminating the film of the thermoplastic resin 13 on the needle loop surface of the knitted fabric 12, a smooth and comfortable artificial leather can be obtained.

Nonwoven fabrics used as artificial leather base materials are a kind of paper and Japanese paper. If a resin film is laminated on the paper or Japanese paper, it becomes a hard cardboard. Even if the stability is improved, a soft and flexible artificial leather cannot be obtained. Therefore, when using a nonwoven fabric for the base material of artificial leather, it is recommended that the nonwoven fabric be used only by impregnating the thermoplastic resin 13 without laminating a resin film. In that case, it is recommended to use a urethane resin as the thermoplastic resin 13 to be impregnated into the nonwoven fabric from the viewpoint of softness and flexibility of the artificial leather.
In addition, from the viewpoint of the soft flexibility of the artificial leather, the nonwoven fabric has an ultrafine thermoplastic synthetic fiber 11 having a single fiber fineness of less than 0.25 dtex, preferably less than 0.20 dtex, more preferably less than 0.10 dtex, particularly It is recommended to use extra fine polyester fibers.

  When the single fiber fineness of the thermoplastic synthetic fiber 11 used for the base material of the artificial leather is increased, the particle size of the molten mass of the hot melt 15 generated at the tip of the ruptured fiber which is heated and melted and broken is also increased. The clothes that come into contact with are caught and easily unraveled. In order to avoid the unraveling of the garment, it is recommended to use a thermoplastic synthetic fiber 11 having a single fiber fineness of less than 0.25 dtex, preferably less than 0.20 dtex, more preferably less than 0.10 dtex, for the base material of artificial leather. The

  The reason why polyester fibers are recommended is that, first of all, the hot melt 15 of polyester fiber is harder and hotter than the hot melt of other synthetic fibers such as polyamide (nylon), polypropylene and polyethylene. The effect of stitching the artificial leather on the front and back by the melt 15 is increased. Second, the melting point is higher than that of polyamide, polypropylene, polyethylene, etc., and the melting point temperature when forming the recessed hole 24 and the through hole 14 Because it is easy to manage.

  When stippling a pattern on the surface with the recessed hole 24 or the through-hole 14, an artificial leather excellent in design can be obtained without giving a stiff impression as if a recessed hole or a vent hole was drilled. .

It is an enlarged plan view of artificial leather using the weft knitted fabric according to the present invention as a base material. It is sectional drawing in the XX line of the artificial leather illustrated in FIG. It is a copy figure of the microscope picture of the section of artificial leather concerning the present invention. It is a top view of artificial leather concerning the present invention. It is a copying figure of the microscope picture of the cross section in the depression hole of the artificial leather which used the nonwoven fabric which concerns on this invention for the base material. It is a top view of the artificial leather which formed the depression hole which concerns on this invention, and is enlarging and enclosing a part in a circle.

  The depressions 24 and the through-holes 14 are formed by using a laser beam irradiation device, irradiating the surface of the artificial leather with a laser beam, and heating the thermoplastic synthetic fiber 11 and the thermoplastic resin 13 with the laser beam.

By the way, when a flame is radiated to the deposited layer of thermoplastic synthetic fiber, a depressed hole is generated, and when radiated as it is, the bottom of the hole is also burned and the depressed hole becomes a through hole. It becomes a tunnel, and the difference in diameter between the entrance and the inside becomes very small.
The same applies to the case where a laser beam is applied to the thermoplastic synthetic fiber deposition layer. If the laser beam is continuously applied for a long time, the distance between the peripheral diameter (D) of the through-hole 14 and the internal diameter (d). However, the wide and narrow gap disappears and the artificial leather expected by the present invention is difficult to obtain.

  Therefore, in the present invention, in order to pierce the recessed hole 24 or the through hole 14 having a wide difference between the peripheral diameter (D) of the peripheral edge 16 and the internal diameter (d) by irradiating the laser beam, the recessed hole is used. No matter how fine the contours of the 24 and the through holes 14 are, the laser beam is instantaneously moved and irradiated along the fine contours so as to trace the fine contours.

  In an artificial leather used for a chair upholstery or a vehicle interior material, the gap between the peripheral diameter (D) of the peripheral edge 16 on the laminated surface side of the film of the thermoplastic resin 13 and the internal diameter (d) of the interior 19 of the through hole 14 is wide. When it is desired to increase the difference, a water-soluble resin composition or emulsion is formed on the back surface of the artificial leather or the back surface of the base fabric 12 of the artificial leather that is heated by the laser beam later than the laminated surface of the film of the thermoplastic resin 13. A backing adhesive such as a resin composition is preferably lined.

  In the case of artificial leather used for chair upholstery and vehicle interior materials, a backing adhesive is preferably lined on the back surface to make it easier to apply to a base material. In order to back the backing adhesive as described above or to make it easy to apply to the base material, it is advisable to apply a raising treatment to the back surface of the artificial leather.

  The artificial leather of the present invention includes both synthetic leather having a thermoplastic resin 13 laminated on its surface (FIG. 3) and artificial leather having the thermoplastic resin 13 soaked therein (FIG. 6). When the surface of the synthetic leather or the artificial leather is irradiated with a laser beam, a thermal melt 15 in which the thermoplastic synthetic fiber 11 and the thermoplastic resin 13 are integrated is generated at the irradiated portion, and the peripheral edge 16 is bordered on the integrated thermal melt 15. This is because a so-called tapered recessed hole 24 or through-hole 14 in which the peripheral edge 16 is in a position recessed from the surface and the diameter d gradually narrows from the peripheral edge 16 toward the inside 19 is generated.

  Artificial leather impregnated with the thermoplastic resin 13 (FIG. 6) can be prepared as synthetic leather (FIG. 3) in which a thermoplastic resin is laminated on the surface thereof and used for the artificial leather of the present invention.

  The thermoplastic resin 13 includes polyester, polyacrylate ester, acrylate copolymer, polyamide (nylon), vinylon, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, ethylene vinyl acetate copolymer, ethylene Vinyl chloride copolymer, ethylene vinyl acetate vinyl chloride terpolymer, polyurethane, polyamino acid, polyamino acid polyurethane copolymer, synthetic rubber and natural rubber can also be used.

The pattern to be stipulated on the surface of the artificial leather is a depression hole distributed in the unit areas 20a, 20b, 20c, 20d,... Of the unit area (4 cm ² ) in which the vertical dimension m and the horizontal dimension n of the artificial leather are 2 cm. 24 and the through-holes 14a, 14b, 14c, 14d,..., The opening area occupancy in the unit area (4 cm ² ) of the opening areas Sa, Sb, Sc, Sd,. -It can be depicted by the difference (difference) in the opening area occupancy ratio of 20b, 20c, 20d.

  The pattern to be stipulated on the surface of the artificial leather is the opening areas Sa and Sb of the recessed holes 24 and the through holes 1, 4a, 14b, 14c, 14d,... Distributed in the unit regions 20a, 20b, 20c, 20d,. It is also possible to change the part of Sc, Sd,..., And draw it by the difference (difference) in the opening areas Sa, Sb, Sc, Sd,.

  The pattern to be stipulated on the surface of the artificial leather partially changes the distribution interval of the recessed holes 24 and the through holes 14a, 14b, 14c, 14d,. It can also be depicted by the difference (difference) in the distribution interval. The pattern may be a geometrical figure, a realistic picture, or an abstract picture, and can be drawn on the whole or part of the artificial leather surface. The inner diameter (d) of the recessed hole 24 and the through hole 14 that are the pixels of the pattern should be 2 mm or less, but in a range not exceeding half of the number of the recessed holes 24 and the through holes 14 depending on the composition of the pattern. It is also possible to form recessed holes and through-holes having an internal diameter (d) of 2 mm or more and 4 mm or less, preferably 2 mm or more and 3 mm or less, preferably in a range that is 20% or less of the number of recessed holes 24 or through holes 14 It is.

  The pattern to be stipulated on the surface of the artificial leather has the peripheral edges 16a, 16b,... Bordering the depressed holes 24 and the through holes 14a, 14b, 14c, 14d,. The shapes of 16c, 16d,... Can be partially changed, and can be depicted by the difference (difference) in the shapes of the peripheral edges 16a, 16b, 16c, 16d,.

In the present invention, the inner diameter (d) of the recessed hole 24 and the through hole 14 is determined by assuming that the void inside is a perfect circle of the diameter d and the opening area S of the recessed hole 24 and the through hole 14 and the inner diameter ( It is calculated by the relational expression S = π × (d / 2) ^{2 with} d).
Here, the opening area S means the area of the air gap inside the through hole viewed through the hole bottom 25 of the recessed hole and the inside of the through hole when the artificial leather supported horizontally is seen in plan view. The area of the air gap is obtained by actually measuring the area of the air gap obtained by copying the air gap.

As described above, in order to make the hot melt 15 fine, the total mass (Q) of the dent forming layer, which is the total value of the mass of the fabric 12 and the mass of the film of the thermoplastic resin 13, is preferably 600 g / m ² or less. Is preferably 500 g / m ² or less.

Apparent thickness measured with a dial thickness gauge in which 57.5 g / m ² (dry weight) of urethane resin is impregnated into a polyester fiber non-woven fabric with a basis weight of 172.5 g / m ² consisting of polyester fiber having a single fiber fineness of 0.04 dtex. Is a non-woven fabric (synthetic fiber felt) having a total weight of 230 g / m ² and a “substantial thickness” of 177 μm (= 230 g / m ² ÷ 1.3 g / cm ³ ). The artificial fabric is irradiated with a laser beam so as to trace a fine circular outline, and the through hole distribution density is 4 / cm ² (the number of through-hole distribution in the unit region is 16/4 cm ² ). A circular through hole having a diameter (d) of 0.86 mm and a through hole opening area of 0.58 mm ² was drilled to finish artificial leather.

  The carbon dioxide laser beam irradiation device has a maximum output of 600 W to 1000 W, an average output of 10 W to 330 W, a laser beam wavelength of 10.6 μm, an oscillation frequency of 25 kHz or less, an operating speed of 4000 mm / min, a beam size of 12 ± 0.5 mm, and a marking line thickness of 0. A 4/2 mm high-tech laser beam irradiation device “Biade RF-333” was used.

The open leather area occupying the unit area (4 cm ² ) of the obtained artificial leather is 2.32%, the air permeability according to JIS-L-1096 (Fragile A method) is 25.37 cc / cm ² / sec, JIS- The bending resistance by L-1096 (cantilever A method) is 6.4 cm, and the hot melt 15 generated by heating with a laser beam protrudes from the peripheral edge 16 of the through-hole 14 and does not protrude to the surface. The diameter d of the hole 14 is gradually narrowed from the peripheral edge 16 of the surface of the artificial leather toward the inside 19 of the depressed hole 24, and is flexible, flexible, soft to the touch, well adapted to the skin, and has high quality as a clothing fabric. It was.

  The artificial leather of the present invention can be used for clothing materials, chair upholstery materials, vehicle interior materials, as well as decorative materials such as wall upholstery materials, furniture surface materials, and cover materials.

d: internal diameter m: longitudinal dimension n: weft dimension D: peripheral diameter 11: thermoplastic synthetic fiber 12: fabric 13: thermoplastic resin 14: through hole 15: hot melt 16: peripheral edge 17: peripheral edge 18: inner wall surface 19 : Internal 20: Unit area 24: Sink hole 25: Hole bottom

The fifth feature of the artificial leather according to the present invention is that, in addition to any of the first, second, third, and fourth features, the artificial leather dent forming layer in which the recessed hole 24 is formed. The basis weight (Q), which is the total mass per unit area of the dent forming layer shown as the total value of the mass of the thermoplastic synthetic fiber 11 and the mass of the thermoplastic resin 13, is 700 g / m ² or less. .

That is, the total mass in a basis weight per unit area of the recess forming layer of the applied artificial leather of the present invention (Q) is 700 g / m ^2, sinkholes Ya formed on the applied artificial leather of the present invention Since the maximum diameter of the through hole is 2 mm, the hot melt generated in the artificial leather to which the present invention is applied has a shape equal to a cube having a dimension of 1.193 mm (≈1.2 mm). If the weight (Q) of the depression forming layer is 700 g / m ² , the substantial thickness is 538 μm (= 0.538 mm), and the recessed hole or the through hole has a maximum diameter of 2 mm, the height is 538 μm (= 0. The wall thickness (tmm) of the cylindrical shape with a diameter of 2 mm is 0.6 mm, and the cylindrical shape is a ring shape whose thickness is about one third of the diameter, and the inner wall surface of the recessed hole 21 and the through hole 14 Touching 18 does not give a sense of incompatibility.

Whether the depressed hole 24 and the through hole 14 affect the touch feeling of the artificial leather depends on whether the hot melt 15 constituting the depressed hole 24 or the through hole 14 is a thermoplastic synthetic fiber that is a raw material of the artificial leather. 11 and the thermoplastic resin 13, and the volume of the hot melt 15 is not due to the thickness or texture of the artificial leather including the internal voids as described above, but the depression in which the recessed holes 24 and the through holes 14 are formed. It is defined by the basis weight (Q) in which the masses of the thermoplastic synthetic fiber 11 and the thermoplastic resin 13 constituting the forming layer are totaled. Therefore, the feature of the artificial leather of the present invention can be defined by the “substantial thickness” of the recess forming layer that is formed of the raw material synthetic fiber and the raw material synthetic resin and in which the recessed hole 24 and the through hole 14 are formed.

Similarly, the weight (Q) of the artificial leather dent forming layer in which the depression 24 is formed is determined by the total weight of the artificial leather (M), the apparent thickness (T) of the entire artificial leather, and the apparent thickness of the dent forming layer. It is calculated as the product (M × t / T) of the ratio (t / T) to the thickness (t) (FIG. 6).
This is because the texture of the artificial leather in which the depressed hole 24 is formed is lower than the bottom (25) of the depressed hole 24 and is not formed in the thermoplastic synthetic fiber or thermoplastic resin in the lower layer that does not constitute the hot melt 15. Because it is not influenced.

If the inner diameter (d) of the depressed hole or the through hole is less than 1 mm, the volume of the hot melt becomes finer and an artificial leather friendly to the skin can be obtained.
That is, as described above, the substantial thickness of the depression forming layer of the depression 24 of the artificial leather having a basis weight (Q) of 700 g / m ² is generally 538 μm. The area of the circular punched piece having a diameter of 1 mm is a circular area having a radius of 0.5 mm, which is 0.0078 cm ² . The volume of the hot melt in this case corresponds to the volume of a circular punched piece having a diameter of 1 mm, and the volume is the area (0.0078 cm ² ) of the circular punched piece having a radius of 05 mm and the real thickness (0. 0538 cm) (0.74 mm) ³ and further smaller. Therefore, even if it touches the depression wall of the artificial leather of the present invention or the inner wall surface 18 of the through hole, it does not give a sense of incongruity.

In addition, in the artificial leather of the present invention, the peripheral edge 16 of the recessed hole 24 and the through hole 14 is in a position recessed from the surface of the artificial leather, and its internal diameter (d) is the peripheral diameter (D) at the peripheral edge 16. Since it gradually narrows toward the inside 19 of the recessed hole 24 and the through-hole 14, the skin does not directly touch the hot melt 15 constituting the inside of the recessed hole 24 and the through-hole 14, and the surface is smooth and soft. It is easy to breathe and provides artificial leather suitable for clothing fabrics, chair upholstery, and vehicle interior materials.
Further, in order to make the hot melt 15 minute, the weight (Q) of the dent forming layer is reduced to 600 g / m ² or less, more preferably 600 g / m ² or less, and the artificial leather has a substantial thickness of generally 460 μm or less. To be.

In order to make the hot melt 15 fine as described above, the basis weight (Q) of the dent forming layer which is the total value of the mass of the fabric 12 and the film of the thermoplastic resin 13 is preferably 600 g / m ² or less, preferably It is desirable to make it 500 g / m ² or less.

Claims (4)

(1) A recessed hole having an inner diameter (d) of 0.3 mm or more and 2 mm or less on the surface of an artificial leather formed by applying a thermoplastic resin (13) to a fabric (12) comprising a thermoplastic synthetic fiber (11) ( 24) is formed,
(2) The peripheral edge (16) of the depression hole (24) and the inner inner wall surface (18) are constituted by the hot melt (15) of the thermoplastic synthetic fiber (11) and the thermoplastic resin (13). And
(3) The periphery (16) of the depression hole (24) is in a position recessed from the surface of the artificial leather,
(4) The internal diameter (d) of the recessed hole (24) gradually narrows from the peripheral diameter (D) at the peripheral edge (16) of the surface of the artificial leather toward the inside (19) of the recessed hole (24). Artificial leather.   The artificial leather according to claim 1, wherein the depression hole (24) is a through hole (14) penetrating the front and back of the artificial leather. The total of the depression forming layer shown as the total value of the mass of the thermoplastic synthetic fiber (11) and the mass of the thermoplastic resin (13) constituting the depression forming layer of the artificial leather in which the depression hole (24) is formed The artificial leather according to claim 1, wherein the mass (Q) is 700 g / m ² or less.   The artificial leather according to any one of claims 1, 2, and 3, wherein a pattern is stippled on the surface by a depression hole (24).

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