JP2001098468A - Leather-like sheet with antibacterial properties - Google Patents

Abstract

(57) [Summary] [Problem] To provide a leather-like sheet excellent in antibacterial property, antifungal property, and deodorant property, and excellent in touch feeling and softness. A leather-like sheet comprising a fiber assembly impregnated with an elastic polymer and a coating layer formed on the surface thereof, wherein the surface of the coating layer is provided with an antimicrobial agent in the form of spots, and A leather-like sheet having a minimum distance of 10 to 100 microns between adjacent spots.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leather-like sheet which is excellent in antibacterial properties, antifungal properties and deodorant properties, has little falling off of antibacterial substances, and is excellent in folding wrinkles and texture.

[0002]

2. Description of the Related Art Conventionally, various leather-like sheets having good antibacterial properties have been proposed. As a typical technique, for example, Japanese Patent Application Laid-Open No. 60-181370 discloses an antibacterial property by coating or laminating a resin containing zeolite-based solid particles holding metal ions having a bactericidal action on the surface of a fiber substrate. A technique for producing a leather-like sheet is described. However, in the case of the antibacterial leather-like sheet obtained by this method, the antibacterial resin layer present on the surface is easy to fall off, and impairs the wrinkles and texture of natural leather which is essential for the leather-like sheet. . Further, if the amount of the antibacterial agent is reduced in order to prevent the antibacterial substance from falling off, creases and deterioration of the texture, the antibacterial performance is reduced.

[0003]

As described above, the conventional antibacterial leather-like sheet does not satisfy both antibacterial properties, creases and texture. The present inventors have conducted intensive studies to eliminate the above-mentioned conventional disadvantages, and as a result, have excellent antibacterial properties,
In addition, a leather-like sheet having excellent folding wrinkles and good texture was found, and the present invention was achieved.

[0004]

That is, the present invention provides an elastic
Fiber aggregate impregnated with polymer and formed on its surface
In a leather-like sheet comprising a coating layer, the surface of the coating layer
Antibacterial agent-containing resin is applied in the form of a spot, and
The distance between a spot and an adjacent spot is 10 to 100 mm
It is a leather-like sheet that is a cron. And preferably,
Antibacterial agents given to the surface of the coating layer are silver, copper, zinc
At least one metal selected from the group consisting of
The above leather-like sheet which is a compound. Also, the coating layer
Constituting polyurethane resin is silicon-modified polyurethane
Made mainly of urethane resin and 100%
Durus is 20-150kg / cm ^TwoIs a leather-like sheet
Is preferred.

Hereinafter, the present invention will be described in detail. First, as the fibers constituting the fiber assembly which is the substrate layer of the present invention,
Examples thereof include ordinary fibers, for example, fibers made of synthetic resin such as polyester, polyamide, polyacrylonitrile, polyolefin, and polyvinyl alcohol, chemical fibers such as regenerated cellulose, and natural fibers such as cotton, hemp, and wool. In the case of a synthetic fiber, not only a fiber composed of a single polymer but also a fiber obtained by mixing or spinning two or more kinds of polymers may be used. When a mixed spun fiber or a conjugate spun fiber is used, at least one polymer is extracted and removed or removed at any stage of producing a leather-like sheet from two or more polymers constituting the fiber. It is preferable to adopt a method of decomposing and removing or a method of dividing and treating each polymer component constituting the fiber to convert the fiber into a bundle of ultrafine fibers or a porous fiber having a large number of hollows inside.

[0006] These fibers are made into a web and entangled by a needle punch or a high-speed fluid flow to form a nonwoven fabric. It can also be a knitted fabric. Further, a laminate of a nonwoven fabric and a knitted fabric can be used. These nonwoven fabrics, woven or knitted fabrics, and their laminated fabrics (hereinafter collectively referred to as fiber aggregates) are impregnated with a solution or dispersion of an elastic polymer. Prior to the impregnation treatment with the elastic polymer liquid, If necessary, the fiber aggregate is subjected to a surface smoothing treatment by a method such as hot pressing. Also, in order to prevent the morphological destruction of the fiber aggregate which is likely to occur during the subsequent impregnation and coagulation of the elastic polymer liquid and the extraction of the fiber constituent polymer, the surface of the fiber aggregate is heated and pressed to partially melt the constituent fibers. It is also possible to use a method of adhering or a method of impregnating and drying a fiber aggregate with a water-soluble resin typified by polyvinyl alcohol and gluing and fixing the fibers. The thickness of the fiber aggregate is 1.0 to
3.0 mm is preferred.

The elastic polymer impregnated in the fiber assembly of the present invention is selected from the group of elastic polymers such as polyurethane, acrylic polymer, acrylonitrile-butadiene copolymer and styrene-butadiene copolymer. At least one type of elastic polymer can be used. Polyurethane is particularly preferred from the viewpoint of the feeling and the adhesive strength with the durable surface layer. Polyurethane has a number average molecular weight of 50
0 to 2500 polymer diols such as polyester diols, polyether diols, polyester ether diols, polycaprolactone diols, at least one diol selected from polycarbonate diols, and organic polyisocyanates such as aromatic diisocyanates; At least one organic polyisocyanate selected from the group consisting of an aromatic triisocyanate, an alicyclic diisocyanate, an aliphatic diisocyanate having a cyclic group, triphenylmethane-4,4,4-triisocyanate, and an active hydrogen atom At least 2
It is a polyurethane elastomer obtained by reacting a low molecular compound having a molecular weight of 300 or less, for example, a low molecular compound containing an active hydrogen atom such as a low molecular diol, a low molecular diamine, hydrazine or dicarboxylic dihydrazide as a chain extender.

The raw material composition of these polyurethanes can be appropriately selected from those satisfying various physical properties such as hand, deterioration resistance, yellowing resistance, dyeing property, etc., according to the intended application field of the leather-like sheet. . If necessary, other polymers, various stabilizers, coloring agents, coagulation regulators and the like are added to these elastic polymers. As described above, the elastic body is impregnated into the fiber aggregate in a state of a solution or a dispersion and solidified. As a coagulation method, a wet coagulation method is preferable in terms of texture. By using the wet coagulation method, the elastic resin becomes porous, and a natural leather-like texture can be obtained. The amount of the resin impregnated in the fiber assembly is 10 parts by weight based on 100 parts by weight of the fiber assembly (in the case where one component in the fiber is removed by extraction or the like, the weight of the fiber assembly after removal). ~ 6
0 parts by weight is preferred.

When the fiber aggregate is composed of a mixed spun fiber or a composite spun fiber composed of two or more kinds of polymers, the fiber is formed before or after the fiber aggregate is impregnated with the elastic resin. It is preferable to use a method of dissolving or decomposing at least one component of the polymer and leaving at least one component. For example, when the mixed spun fiber or the conjugate spun fiber is a fiber having a sea-island structure cross section, when the sea component polymer is dissolved or decomposed and removed, the island component polymer remains, and the fiber becomes an ultrafine fiber bundle. When dissolved and removed, the sea component remains to form a porous fiber having many hollow portions in the fiber. When the fiber is a composite spun fiber obtained by laminating a plurality of polymers in the length direction, a method in which the fiber is separated from the polymer by physical treatment or chemical treatment to make the fiber into an ultrafine fiber bundle. May be used. 0.0001 ~
0.1 denier, especially the range of 0.001 to 0.05 denier is preferable.

After the fiber assembly is impregnated with the elastic resin, a coating layer made of the elastic resin is formed on the surface of the fiber assembly so as to resemble natural leather with silver. In the present invention, at least the surface side (the surface opposite to the adhesive surface) of the coating layer is made of a silicon-modified polyurethane resin cross-linked by a polyisocyanate-based curing agent when the wear resistance and the abrasion resistance are reduced. Is preferred. The type of the silicone-modified polyurethane resin, which is a suitable elastic resin constituting the surface layer of the coating layer, is not particularly limited, and includes polyester, polyether, and polycarbonate resins. Then, a polyether type or a polycarbonate type is preferable. As silicone modified polyurethane resin,
It is a polyurethane modified by introducing a dimethylsiloxane unit into the main chain or side chain of the polyurethane. As for the degree of silicon modification, it is preferable that 5 to 50% by weight of dimethylsiloxane units be present in the polyurethane.

In particular, the silicone-modified polyurethane resin 10
A resin having a 0% modulus of 10 to 150 kg / cm ² is preferable. When the 100% modulus is less than 10 kg / cm ² , the tackiness is very strong and the surface strength is weak. When the 100% modulus exceeds 150 kg / cm ² , the surface layer becomes hard and the bending resistance becomes poor. Preferably it is 20 to 100 kg / cm ² . The resin for forming the coating layer is used in the form of a solution or an emulsion.

The method for forming the coating layer may be a method of directly applying the coating solution on the fiber aggregate, or a method of coating the resin solution for the coating layer on release paper in advance and coagulating it.
A method may be used in which a resin liquid serving as an adhesive is applied thereon, and is superposed on and integrated with the fiber aggregate, and then the release paper is peeled off. As the resin used as the adhesive in this method, a two-component curable polyurethane is preferable because a strong adhesive force can be obtained. As a method of solidifying the surface of the coating layer, a dry-type surface is used. Of course, in the resin forming the coating layer, if necessary, an antioxidant, an ultraviolet absorber, a pigment, a dye, a surfactant, an antistatic agent, a flame retardant, a filler, etc. as long as the reaction of the curing agent is not inhibited. Various additives, collagen powder and the like can also be added. Note that 100
The% modulus is measured by the strength at 100% elongation from the stress and elongation curve of a dry film having a thickness of 100 microns produced from a resin solution. As the thickness of the coating layer, 30 to
A range of 150 microns is preferred.

An antimicrobial agent is spot-applied to the surface of the coating layer to impart antimicrobial properties. As antibacterial agents,
Preferably, it contains an antibacterial metal component from the viewpoint of the durability of the antibacterial effect, and specific examples thereof include an antibacterial metal itself or a compound of such a metal. Those in which these antibacterial metal components are supported by an inorganic oxide other than the antibacterial metal component serving as a carrier are preferable in view of the durability of the antibacterial effect. As the antibacterial metal component, known antibacterial metal components can be used, for example, silver, copper, zinc,
There are metals or compounds thereof such as tin, lead, bismuth, cadmium, chromium, and mercury. In particular, one or more antibacterial metal components selected from silver, copper, and zinc are preferable from the viewpoints of antibacterial action, discoloration, and safety to the human body. In the antimicrobial metal component supported on a carrier that is a suitable antimicrobial agent in the present invention, the amount of the antimicrobial metal component is as pure metal,
It is desirable to be within the range of 1 to 30% by weight. When the amount of the antibacterial metal component is less than 1% by weight, the antibacterial effect is not sufficiently exhibited. When the amount of the antibacterial metal component exceeds 30% by weight, an antibacterial effect is exhibited, but the discoloration becomes severe and there is a problem in quality. The preferred amount of the antibacterial metal component is in the range of 5 to 15% by weight in terms of pure metal.

On the other hand, as the inorganic compound for a carrier other than the antibacterial metal component used in the present invention, for example, SiO ₂ , TiO ₂ , ZrO ₂ , Fe ₂ O ₃ , S
b ₂ O _{5 and the} like, and as the composite oxide, for example,
SiO ₂ · Al ₂ O ₃ , SiO ₂ · TiO ₂ , SiO ₂ · Al
_{There are 2} O ₃ .MgO, SiO ₂ .Al ₂ O ₃ .TiO ₂ and the like. Among them, SiO ₂ · A in terms of dispersibility and safety
l ₂ O ₃ .MgO is preferred. In particular, as the antibacterial agent used in the present invention, in consideration of antibacterial action, safety, dispersibility, discoloration, etc., one or both of silver oxide and zinc oxide are supported on silicon oxide, aluminum oxide, and magnesium oxide. The one that is let is the best. The average particle size of the antibacterial metal component supported on a carrier is desirably 200 microns or less. If the average particle size is larger than 200 microns, the dispersibility with the resin will be poor, and the texture will be poor, and the resin will easily fall off. More preferably, it is in the range of 2 to 50 microns, even more preferably 5 to 30 microns.

[0015] Such an antibacterial agent is added to a resin solution or a resin emulsion solution and applied in the form of spots on the surface of the leather-like sheet. In the present invention, the antibacterial agent-containing resin needs to be present in the form of spots, and does not exist in the form of spots, for example, when present as a continuous layer or as a layer that is continuous in one direction. If it is, the adhesion to the lower layer is poor, and the bending resistance is poor, so that the wrinkles and the texture are deteriorated. In the present invention, the size of each spot is preferably 10 ⁻⁴ to 10 ⁻² mm ² . The antibacterial agent may be applied by any of known methods such as a spray method, a gravure printing method, a printing method, a transfer method, and the like, and a gravure printing method is preferable as a method of easily applying the antibacterial agent in a spot form. In order to achieve both the antibacterial property and the tactile property of the leather-like sheet, which is a feature of the present invention, the shortest distance between a spot and a spot adjacent thereto is 10 to 100.
It is necessary to maintain microns.

If the shortest distance is less than 10 microns, the adhesion to the lower layer will be poor. On the other hand, if it exceeds 100 microns, the adhesiveness is good but the antibacterial effect is inferior. A preferable application amount of the antibacterial agent is 0.2 to 5 g / in terms of pure metal.
m ² . When the coating amount is less than 0.2 g / m ² , the effect on the antibacterial property is small, and when it exceeds 5 g / m ² , the texture becomes poor and the bending resistance is poor.

Examples of the resin include commonly used polyurethane resins, for example, polyester-based polyurethane resins, polyether-based polyurethane resins, polycarbonate-based polyurethane resins, and silicone-modified products of these resins. And a polycarbonate resin or a silicon-modified resin thereof is preferred. The application amount of the antimicrobial-containing resin is 2 to 50 g / in terms of resin solid content.
m ² is particularly preferred. When the coating amount is less than 2 g / m ² , the antibacterial effect is small. On the other hand, when it exceeds 50 g / m ² , the texture becomes poor, the flexibility is poor, and the wrinkles are rough. More preferably, it is in the range of 5 to ²⁰ g / m ² . More preferably, it is in the range of 5 to ²⁰ g / m ² .

In the present invention, a coloring agent may be added to the above-mentioned coating layer or the resin layer of the antibacterial agent to be present in the form of spots on the surface thereof, and a pigment or dye is used as the coloring agent to be added. You. As pigments, inorganic pigments such as carbon black and titanium oxide, and organic pigments such as ferocyanine-based, azo-based, and anthraquinone-based pigments are used. As the dye, a gold-containing complex dye, an acid dye, a sulfur dye, a disperse dye or the like is used, and a gold-containing complex dye is desirable in terms of light resistance, fastness and the like. The addition amount is preferably 1 to 30 parts by weight based on 100 parts by weight of the resin.

It is also possible to carry out embossing, kneading or relaxing as required.

The leather-like sheet obtained in the present invention has excellent abrasion resistance, scratch resistance, abrasion resistance and fold wrinkles, and furthermore has a good texture. These leather-like sheets are very suitable for applications such as balls, bags, bags, sports shoes and general shoes.

[0021]

EXAMPLES Next, the present invention will be described specifically with reference to Examples.
The present invention is not limited to these examples. In the examples, parts and percentages relate to weight unless otherwise specified.

Example 1 A sea-island composite fiber comprising 60 parts of 6-nylon (island component) and high-flowability low-density polyethylene (sea component) was obtained by melt spinning, and this was 2.5-fold in hot water at 70 ° C. It was stretched, coated with a fiber oil agent, mechanically crimped and dried, and then cut into 51 mm to obtain 4-denier staple fibers. The stable fiber is formed into a web having a basis weight of 500 g / m ² by a scrap method, and is then alternately combined from both sides to about 50 g.
Needle punching at 0 punch / cm ² was performed, and the mixture was further heated at 120 ° C. and pressed with a calender roll to form an entangled nonwoven fabric having a smooth surface. The basis weight of this entangled nonwoven fabric was 340 g / m ² , and the apparent specific gravity was 0.3.
This entangled non-woven fabric is impregnated with a 13% polyurethane dimethylformamide (DMF) solution mainly composed of polytetramethylene ether-based polyurethane, and immersed in a mixture of DMF / water = 15/85 to make the polyurethane porous. After wet coagulation into a qualitative form, the sea component in the composite fiber is eluted and removed in hot toluene to remove the ultrafine fiber (average fiber thickness 0.001).
(Denier) and a fibrous sheet substrate layer was obtained. The obtained fibrous base material layer had a thickness of 1.0 mm and the amount of polyurethane was 120 g / m ² .

On the other hand, release paper with a grain (LINTEC TP)
R-8) as a skin layer, a silicon-modified polyether-based polyurethane (US-938, 100 manufactured by Seiko Chemical Co., Ltd.).
% Modulus 60 kg / cm ² solid content 30%) 100
Parts, trimethylolpropane polyisocyanate curing agent 5 parts (NE crosslinker NE cross-linking agent solid content 80%), Resamine DUT4093 white (Dainichi seika titanium oxide, solid content 5
0%) 30 parts, DMF 30 parts, methyl ethyl ketone 30
A part of the polyurethane resin solution was applied to a dry base of 50 μm and heated at 100 ° C. for 5 minutes to obtain a skin layer. On top of that, one-pack type polyether-based polyurethane (Resamine ME8133-2 solid content 30%, manufactured by Dainichi Seika)
100 parts of a polyurethane resin solution of 20 parts of DMF is applied by wet to 100 g / m ² , bonded to the fibrous sheet substrate layer, dried at 100 ° C. for 2 minutes, and then at 40 ° C. for 1 day After leaving, the release paper was peeled off to obtain a leather-like sheet. Rezamine TC400 on the surface
0 (15% polyether polyurethane manufactured by Dainichi Seika) 1
To 00 parts silver-based antibacterial agent AIS-NAZ320 (catalyzed chemical compound silver-based compound: antibacterial compound: AgO and ZnO, carrier: 2S)
iO2.Al2O3, pure metal component is 10% by weight based on 100% of solid portion, average particle size is 30 microns) 1 part is 14 parts
An amount of 200 g / m ² was applied using a 0 mesh grid-like gravure roll (140 lines / 1 inch, cell depth 50μ). The distance between the spots was 20 microns.
A kneading treatment was performed to further impart flexibility. The obtained leather-like sheet had a soft texture and also had an antibacterial property, and the result of the antibacterial film adhesion method measurement (Staphylococcus aureus, Escherichia coli) increased / decreased by 3.0 and passed (2.0 or more). . The obtained leather-like sheet had a soft texture with fine wrinkles. This was perfect for a kitchen shoe blank.

Example 2 50 parts of 6-nylon kneaded with a black pigment was dispersed in a
An entangled nonwoven fabric of multicomponent fibers containing 50 parts of polyethylene as a dispersion medium component was produced in the same manner as in Example 1. The basis weight was 450 g / mm and the apparent specific gravity was 0.26. An 18% dimethylformamide (DMF) solution of a polyethylene adipate / polyethylene glycol copolymer-based polyurethane containing a black coloring agent is impregnated, and the same type of solution is knife-coated with 80 g / m ^{2 of} knife in a 25% DMF aqueous solution. After coagulation, polyethylene in the multicomponent fiber was dissolved and removed to obtain a fibrous sheet base layer made of ultrafine fibers of 0.002 denier. The obtained fibrous sheet base layer had a basis weight of 500 g / m ² and a thickness of 1.3 mm. The resin impregnation amount was 120 g / m ² . The skin layer is made of polycarbonate silicone-modified polyurethane (Chris Bon NY3)
24 (made by Dainippon Ink, 100% modulus 40 kg /
cm ² , solid content 15%) was subjected to four-stage gravure 150 mesh treatment, and the coating amount was adjusted to 60 g / m ² with a resin solution. On top of that, embossing was performed using a wrinkle embossing roll under the conditions of a temperature of 150 ° C., a press pressure of 2 kg / cm ² , and a speed of 2 m / min. On top of that, Rezamine TC-7 (manufactured by Dainichi Seika, 100% modulus 80 kg / cm 2, solid content 15
%), 100 parts of the antibacterial agent used in Example 1 was added, and a gravure coating treatment was performed at a coating amount of 5 g / m ² with a cloud print roll using a resin solution. The size of the obtained spot was 5 × 10 ⁻³ mm ² and the distance between the spots was 50 microns. The obtained leather-like sheet had excellent antibacterial properties and good texture, and was optimal as a raw material for sports shoes.

COMPARATIVE EXAMPLE 1 In Example 1, a resin having an antibacterial agent applied to its surface was applied in a solid content of 20 g / m ² to the entire surface by using a direct roll instead of a spot-like resin. The obtained leather-like sheet had good antibacterial properties, but had a hard feel and poor flexibility, and had a lower commercial value than that of Example 1.

Table 1 shows the evaluation results of the leather-like sheets obtained in Examples and Comparative Examples.

[Table 1]

[0027]

The leather-like sheet obtained by the present invention is a leather-like sheet having excellent antibacterial properties, antifungal properties, and deodorant properties, and having good wrinkles and texture. These leather-like sheets are balls,
It is very suitable for applications such as bags, bags, sports shoes, and general shoes.

Claims (3)

[Claims] 1. A leather-like sheet comprising a fiber aggregate impregnated with an elastic polymer and a coating layer formed on the surface thereof, wherein the surface of the coating layer is provided with an antimicrobial agent-containing resin in the form of spots, A leather-like sheet having a minimum distance between a spot and an adjacent spot of 10 to 100 microns. 2. The antibacterial agent provided on the surface of the coating layer,
The leather-like sheet according to claim 1, wherein the leather-like sheet is at least one metal selected from the group consisting of silver, copper, and zinc or a compound thereof. 3. The polyurethane resin constituting the coating layer is mainly composed of a silicon-modified polyurethane resin, and has a 100% modulus of 20 to 150 kg / c.
The leather-like sheet according to claim 1, which has a m ² of ² .