JP2809803B2 - Leather-like sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention has a smooth texture and a good sweat-absorbing property, in which the touch of the hand touches sweat like natural leather without sliminess. Further, the present invention relates to a leather-like sheet which has a solid appearance and color depth similar to that of natural leather, has a mat-like appearance, and is excellent in surface strength.

<Conventional technology> Conventionally, as a mat-like leather-like sheet, nap of fine fibers is formed on the surface, buffed with sandpaper or the like to shorten the hair, and elastic polymer such as polyurethane is used. There have been proposed ones in which a porous coating layer is formed, and a skin layer on the surface is removed by grinding to expose a part of fine pores. However, all of them had an appearance close to a suede of natural leather, far from a matte appearance with a fine embossment.

Also, many attempts have been made to reproduce natural leather-like appearance and texture by mixing natural leather powder, collagen, and the like into the coating layer of the leather-like sheet. For example, Japanese Patent Publication 63-2364
No. 4, JP-B-63-315677, and the like. These leather-like sheets were merely mixed with leather powder or collagen powder having a large particle size, and the surface condition was far from matte.

<Problems to be Solved by the Invention> The present invention is similar to natural leather because it has a smooth texture and a good sweat-absorbing property that the touch to the hand does not have the slimy feeling of sucking sweat like natural leather. The object is to provide a leather-like sheet which has a solid appearance and depth of color, and which looks dark with a fine matte tone and excellent surface strength.

<Means for Solving the Problems> The present invention provides a leather-like sheet comprising a base layer containing a polymer mainly composed of an elastic polymer in a fiber aggregate and a coating layer of a polymer mainly composed of an elastic polymer. In, the surface of the coating layer is non-fibrous, the average particle size is 10μ or less and apparent bulk density 0.1
A leather-like sheet comprising a mixture of collagen powder of about 0.3 g / cm ³ and a polymer mainly composed of polyurethane and having fine irregularities.

That is, the present invention relates to a method of manufacturing a fiber assembly such as a woven fabric, a knitted fabric, or a fiber entangled nonwoven fabric made of any fiber such as ordinary fiber, ultrafine fiber and / or bundled fiber thereof, and special porous fiber. Containing an acrylic polymer, an acrylonitrile-butadiene copolymer, a polymer mainly composed of at least one elastic polymer selected from the group of elastic polymers such as synthetic rubbers such as a styrene-butadiene copolymer. Layer consisting of a polymer mainly composed of an elastic polymer and a fiber assembly obtained by the above method, and a porous layer of a polymer mainly composed of an elastic polymer such as polyurethane or plasticized polyvinyl chloride on one surface of the substrate layer. Alternatively, a sheet-like material having a non-porous layer as a surface layer is formed, and a polyurethane composition solution containing collagen powder is applied to the surface and dried to produce a leather-like sheet. A.

The base layer of the present invention may be formed of ordinary fibers, for example, synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin, and polyvinyl alcohol, synthetic fibers such as regenerated cellulose, natural fibers, or fibers in a special form, for example, polyesters and polyamides. Needle punch or high-speed fluid composed of fibers selected from ultra-fine fibers such as polyacrylonitrile or multi-component fibers that can be transformed into ultra-fine fiber bundles or special porous fibers by dissolving and removing at least one component One type of fabric selected from a fabric entangled by flow, such as a fiber entangled nonwoven fabric, a fiber-woven knitted woven fabric, or a laminated fabric of a nonwoven fabric and a woven fabric, is impregnated with a composition liquid for impregnation mainly comprising an elastic polymer. Then, if necessary, then apply a polymer coating composition on one side and in a polymer non-solvent Solidifying the sponge structure, the multicomponent fibers and transformed into microfine fiber bundles fibers or special porous fibers, further elastic polymer sheet imparted with polymeric coating layer consisting mainly of needed.

If the base layer is made of ordinary fibers, especially those made of polyester or polyamide fibers, the leather-like sheet becomes moderately stiff and excellent in shape retention, and if it is made of ultrafine fiber bundle fibers, When processed into shoes with a soft texture, the top line becomes sharp, and if you use special porous fiber, it will have a moderate waist and lightness, and the surface has a smooth texture and appearance It is an artificial leather product full of luxury, combined with a solid feeling and a deep color tone.

The collagen used in the coating layer in the present invention is obtained by treating and purifying animal skin, bones and tendons with an enzyme or the like, extracting high molecular collagen fibers, causing a cross-linking reaction between the collagen fibers, and then pulverizing. the average particle diameter 2～10Myu, a apparent bulk density of 0.1 to 0.3 g / cm ^3, preferably close-packed bulk density
A non-fibrous collagen powder of 0.4 to 0.6 g / cm ³ , such as CX240 or CX260 manufactured by Showa Denko. When the average particle size of the collagen is larger than 10 μm, the surface becomes rough and a fine smooth surface cannot be obtained, and a natural leather-like smooth and natural touch cannot be obtained. When the apparent density is greater than 0.3 g / cm ³ , the bulk of the collagen particles is reduced, so that the affinity with the resin is reduced, the coating strength is reduced, and the appearance and touch of the fine matte tone are reduced. Is difficult to obtain, and the durability also decreases. Furthermore, the ability to inhale moisture and sweat is reduced, and the desired sweat absorption property cannot be obtained. On the other hand, when the apparent bulk density is less than 0.1 g / cm ³ , the strength of the collagen particles decreases and the strength of the coating film decreases. Accordingly, in order to increase the adhesiveness to the resin and obtain a fine matte finish, it is preferable that the average particle size of collagen is 10 μm or less and the apparent bulk density is 0.1 to 0.3 g / cm ³ . In the present invention, the apparent bulk density is JIS
Determined by K 6721.

The weight ratio of the collagen powder to the polyurethane-based polymer is in the range of 1: 1 to 2: 1. If the amount of the collagen powder is small, the characteristic of collagen such as sweat absorption and a smooth touch cannot be obtained, and if the amount of collagen is large, the collagen powder cannot be sufficiently fixed by the polymer, and the film strength is reduced. The texture also worsens.

In the present invention, the polyurethane mixed with the collagen powder is a polymer diol having an average molecular weight of 500 to 2500, for example, at least one selected from the group of polyester diol, polyether diol, polyester ether diol, polycaprolactone diol, polycarbonate diol and the like. And a polymer diol of an organic polyisocyanate such as an aromatic diisocyanate, an aromatic triisocyanate, an alicyclic diisocyanate, an aliphatic diisocyanate having a cyclic group, and triphenylmethane
Polyurethane obtained by reacting at least one organic polyisocyanate selected from the group of 4,4 ', 4 "-triisocyanate with a low molecular compound having at least two active hydrogen atoms as a chain extender. .

A polymer composition mainly composed of collagen and polyurethane is applied to the surface as a dispersion in which collagen powder is dispersed in a polymer solution. Colorants such as dyes and pigments, stabilizers, antistatic agents, leveling agents, and the like are added to the coating solution depending on the purpose. As a method of applying, for example, a roll application method using a roll having a notch, a smooth surface roll, or the like, a coating method, a spray coating method, a surface contact method, or the like is used. A preferable coating method is a roll coating method from the viewpoint of uniformity of coating and high air permeability and moisture permeability of the coating film.

The coating amount, 5 to 50 g / m ² by weight of dry collagen,
Preferably in the range of 5 to 30 g / m ^2. If the amount of collagen applied is less than 5 g / m ² , the entire surface is not covered with the collagen powder, so that the entire surface does not have a fine matte surface and a smooth touch cannot be obtained. When the amount of collagen and the amount of coating are large, the appearance does not deteriorate so much, but the film strength is reduced and the durability is poor.

The surface provided with the polymer composition mainly composed of collagen and polyurethane has fine irregularities having a size substantially equal to the size of the collagen particles. The light is scattered by the fine irregularities, and the appearance becomes a matte appearance without glare. Collagen particles are not completely covered by the polymer, and many of the collagen particles are directly exposed to the surface. The leather-like sheet of the present invention can be colored with a pigment, but it is preferable to dye the leather-like sheet because the color has more depth. As a dyeing method, a metal complex salt dye, an acid dye, a disperse dye, or the like is used, and dyeing is performed by a Wins dyeing method, a Jigger dyeing method, or the like.

The leather-like sheet obtained in the present invention has a good sweat-absorbing property,
It has the smooth texture of natural leather and the smooth, natural touch similar to natural leather without the slimy feel. It becomes a leather-like sheet with excellent surface strength.

The leather-like sheet of the present invention is suitable for use in shoe uppers such as sports shoes and men's shoes, bags, bags, clothing, gloves and the like.

<Examples> Next, embodiments of the present invention will be described with specific examples, but the present invention is not limited to these examples.
The parts and percentages in the examples relate to weight unless otherwise specified.

Example 1 20% dimethylformamide (DMF) of a polyethylene adipate-based polyurethane containing a blue-based coloring agent was used as a base sheet in an entangled nonwoven fabric of multicomponent fibers containing polyethylene terephthalate as a dispersion component and polyethylene as a dispersion medium component.
The solution was impregnated with, 40% DMF and further the amount applied of 150 g / m ² on the surface
A sheet having a microporous polyurethane surface layer on one surface of a base layer in which polyurethane is contained in a porous state in a nonwoven fabric of ultrafine fiber bundles obtained by dissolving and removing polyethylene after coagulation in an aqueous solution was used. A collagen powder 50 having an average particle size of 5 μm and an apparent bulk density of 0.25 g / cm ^{3 was} added to 100 parts of a 30% polyester polyurethane DMF solution on the surface of the base sheet.
And a composition liquid containing 15 parts by weight of a black pigment were applied by a roll coating method using a gravure roll to 50 g / m ² and dried. Then, using a satin embossed roll,
Heat embossing was performed at a humidity of 150 ° C., and after dyeing with a metal complex dye, mechanical rubbing was further performed to complete the leather-like sheet A.

The obtained leather-like sheet A has a soft texture, a good sweat-absorbing property, a smooth texture similar to that of natural leather, and a tactile sensation having a smooth and natural touch without slimy feeling. It had a fine matte tone and had a deep blackness similar to natural leather and a solid appearance. Further, when the surface was observed with an operation-type electron microscope, it was found that the collagen particles had a fine uneven surface while being half-buried in polyurethane.

When the leather-like sheet A was used to produce men's shoes and women's shoes, the top line was sharp with a soft texture like a calf and had a high-class feel.

Comparative Example 1 In Example 1, the average particle size was 30 as the collagen powder.
A leather-like sheet B was finished in the same manner except that collagen powder having a thickness of 0.5 μm and an apparent bulk density of 0.5 g / cm ³ was used.

The leather-like sheet B had a sweat-absorbing but rough surface, was rough in appearance, and had a poorly finished suede-like appearance.

Example 2 As a substrate sheet, a sheet obtained by impregnating and coagulating a polyethylene adipate-based polyurethane in a woven nonwoven fabric of polyester short fibers having a fineness of 1.5 denier in the same manner as in Example 1 was used. On the surface of the base sheet, 100 parts of a 30% DMF solution of a polyester-ether polyurethane was added to an average particle diameter of 7 μm.
m, a composition solution to which 40 parts of collagen powder having an apparent bulk density of 0.2 g / cm ³ was added was applied at 40 g / m ² by a roll coating method using a gravure roll, and dried. The surface of this sheet was heated and embossed at a temperature of 150 ° C. using a calf-like embossing roll to complete a leather-like sheet C.

The obtained leather-like sheet C had a moderate waist, had a fine matte tone on the surface, had a smooth texture without the sliminess of natural leather, and had a deep blackness. Using this leather-like sheet C, men's shoes and a camera case were produced, all of which were excellent in moldability and shape retention, and were of high commercial value combined with a unique smooth touch and color tone. Was.

Example 3 As a base sheet, an entangled nonwoven fabric of multicomponent fibers containing 6-nylon as a dispersion medium component and polystyrene as a dispersion component,
Impregnated with a 20% dimethylformamide (DMF) solution of polyethylene adipate polyurethane containing a blue colorant,
In addition, a non-woven fabric of special porous fiber obtained by applying 150 g / m ^{2 on} the surface and coagulating in a 40% DMF aqueous solution followed by dissolving and removing polystyrene, the polyurethane is contained in a porous state on one side of the base layer is polyurethane A sheet having a microporous surface layer was used. On the surface of the base sheet, 100 parts of a 30% DMF solution of a polyester-ether polyurethane was added to an average particle diameter of 7 μm.
m, a composition liquid to which 30 parts of collagen powder having an apparent bulk density of 0.2 g / cm ³ was added was applied at 40 g / m ² by a roll coating method using a gravure roll, and dried. Next, heating embossing was performed on the surface coating layer with a satin embossing roll to obtain a leather-like sheet. This leather-like sheet was finished by further rubbing.

The obtained leather-like sheet has a profound feeling of appearance, but it is light when held in hand, the surface is smooth and has a fine matte tone with a deep blackness, a load of 500 g by Gakushin type flat wear tester, No abnormalities were observed after the abrasion test 1000 times.

This leather-like sheet was a suitable material for bags, school bags, and sports shoes.

<Effects of the Invention> The leather-like sheet of the present invention has a smooth texture and a good sweat-absorbing property without the slimy feeling that the wet feeling of the hand sucks sweat like natural leather, and is similar to natural leather. It is a leather-like sheet with excellent surface strength, which has a solid appearance and depth of color, and looks dark with a fine matte tone.

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Claims (1)

(57) [Claims] A leather-like sheet comprising a base layer containing a polymer mainly composed of an elastic polymer in a fiber aggregate and a coating layer of a polymer mainly composed of an elastic polymer, wherein the surface of the coating layer is Non-fibrous, average particle size 10μ or less and apparent bulk density 0.1
A leather-like sheet comprising a mixture of collagen powder of about 0.3 g / cm ³ and a polymer mainly composed of polyurethane and having fine irregularities.