JPH1193084A - Leathery sheet excellent in antifouling property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a leathery sheet, good in antifouling properties and water and oil repellencies and capable of simply removing foulings when the foulings such as mud, tobacco ash or a water-based pen or a water based pen/an oil- based pen stick thereto, excellent in adhesion and good in touch feeling. SOLUTION: This leathery sheet is obtained by fixing a resin containing a fluororesin in an amount of 1-10 pts.wt. and a silicone resin in an amount of 0.5-5 pts.wt. based on 100 pts.wt. polyurethane resin in the form of spots on the surface of a substrate layer containing a polymer consisting essentially of an elastic polymer in a fiber assembly. The shortest distance between the mutually adjacent spots is 10-100 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has excellent antifouling properties,
The present invention relates to a leather-like sheet which can easily remove stains such as tobacco ash, water-based pens, water-based / oil-based pens and the like, and has good water and oil repellency and good adhesion.

[0002]

2. Description of the Related Art Conventionally, as an antifouling leather-like sheet,
It has been proposed that a porous wet film or a dry film made of an elastic polymer is provided on the surface of a fibrous base layer, and a fluororesin is provided on the surface by a spray method. Although it has a certain degree of antifouling properties, it has insufficient antifouling durability and little adhesion to other substances, and the desired product has not been obtained. As another method, Japanese Patent Publication No. 61-39437 has developed a method in which a fluororesin / silicone resin is adhered to the entire surface and the surface of a leather-like sheet.

[0003]

However, the leather-like sheet obtained by such a method has good antifouling properties, but has poor flexibility and poor adhesion between the surface layer and the substrate layer. No good texture was obtained. The present inventors have conducted intensive studies in order to solve the above-mentioned drawbacks of the prior art, and as a result, have found a leather-like sheet having good adhesion and good antifouling property and good texture, and have reached the present invention.

[0004]

That is, according to the present invention, there is provided a fiber assembly comprising a base layer containing a polymer mainly composed of an elastic polymer, a fluororesin based on 100 parts by weight of a polyurethane resin. 10 parts by weight and silicone resin 0.5 ~
A leather-like sheet wherein a resin composition containing 5 parts by weight is fixed in a spot shape, and the shortest distance between a spot and an adjacent spot is 10 to 100 microns.

More preferably, in the leather-like sheet, the 100% modulus of the polyurethane resin used for the surface layer is 10 to 80 kg / cm.
² is a leather-like sheet.

Hereinafter, the present invention will be described in detail. The fibers that can be used as the fiber assembly constituting the base layer of the present invention include ordinary fibers, for example, synthetic fibers made of polymers such as polyester, polyamide, polyacrylonitrile, polyolefin, and polyvinyl alcohol, and chemical fibers such as regenerated cellulose. And natural fibers. In the case of synthetic fibers, 0.5 denier is obtained by dissolving and removing at least one component of ultrafine fibers of 0.5 denier or less made of a polymer such as polyester or polyamide. Multicomponent fibers or the like which can be modified into bundle fibers or porous hollow fibers made of the following ultrafine fibers can also be used. These fibers are entangled with a needle punch or a high-speed fluid flow to form a nonwoven fabric. In addition, a fabric such as a raised knitted fabric or a laminated fabric of a nonwoven fabric and a knitted fabric can be used. Prior to impregnation with the elastic polymer solution, the surface of these nonwoven fabrics, woven or knitted fabrics or laminated fabrics thereof (hereinafter collectively referred to as a fiber aggregate) is smoothed by a conventionally known method such as pressing if necessary. Do the processing. The thickness of the fiber aggregate is preferably from 1.0 to 3.0 mm.

The elastic polymer impregnated in the fiber assembly of the present invention is selected from the group consisting of polyurethane polymers, acrylic polymers, acrylonitrile / butadiene copolymers, and styrene / butadiene copolymers. At least one selected elastic polymer can be mentioned. Polyurethane-based polymers are particularly preferred from the viewpoints of texture, adhesion strength with the durable surface layer, and the like. As the polyurethane polymer, a polymer diol having a number average molecular weight of 500 to 2500, for example, at least one diol selected from polyester diol, polyether diol, polyester ether diol, polycaprolactone diol, polycarbonate diol, and the like. An organic polyisocyanate, for example, at least one selected from the group consisting of aromatic diisocyanate, aromatic triisocyanate, alicyclic diisocyanate, aliphatic diisocyanate having a cyclic group, and triphenylmethane 4,4,4-triisocyanate. It is a thermoplastic polyurethane obtained by reacting a kind of organic polyisocyanate with a low molecular compound having at least two active hydrogen atoms as a chain extender. The composition of these polyurethanes can be appropriately selected from those satisfying various physical properties such as hand, deterioration resistance, yellowing resistance, and dyeability, depending on the intended use field of the leather-like sheet. The polymer mainly composed of the elastic polymer is impregnated into the fiber aggregate in a solution or dispersion state and solidified. As a coagulation method, a wet coagulation method is preferable in terms of texture. The amount of the resin to be impregnated into the fiber assembly is 10 to 60 parts by weight based on 100 parts by weight of the fiber assembly as a solid.
Parts by weight. When the fiber aggregate is a multi-component fiber that can be modified, a method of dissolving and removing one component constituting the fiber before or after impregnation with the resin is used.

The polyurethane resin layer used for the surface layer is the same as the polyurethane polymer used for the above-mentioned elastic polymer, and is a polymer diol having an average molecular weight of 500 to 2500, for example, polyester diol, polyether diol. , Polyester ether diol,
At least one diol selected from polycaprolactone diol, polycarbonate diol and the like, and an organic polyisocyanate, for example, aromatic diisocyanate, aromatic triisocyanate, alicyclic diisocyanate, cyclic group-containing aliphatic diisocyanate, triphenyl Thermoplastic polyurethane obtained by reacting at least one kind of organic polyisocyanate selected from the group of methane 4,4,4-triisocyanate with a low molecular compound having at least two active hydrogen atoms as a chain extender It is. The composition of these polyurethane-based polymers can be selected appropriately according to the intended application field of the leather-like sheet, but polyether-based polyurethane is the best in terms of texture, deterioration resistance, yellowing resistance, cost and the like. It is.

Above all, the polyurethane resin used for the surface layer has a 100% modulus of 10 to 80 kg / kg.
Resins having a cm ² are particularly preferred. If the 100% modulus is less than 10% kg / cm ² , the tackiness is very high,
Surface strength decreases. The 100% modulus is 80
If it exceeds kg / cm ² , the surface layer becomes hard and the bending resistance becomes poor. Preferably it is 20 to 60 kg / cm ² .
The resin for forming the surface layer is used in the form of a solution or an emulsion.

The fluororesin contained in the polyurethane elastic resin layer forming the surface layer has a fluorocarbon group such as perfluoroalkyl, perfluoroalkenyl ether, perfluorohexacenyl or the like in a side chain. And a fluorine-containing polymer having a main chain of a polyacrylate or methacrylate polymer or the like. The silicon resin is a silicon resin such as dimethylpolysiloxane or a copolymer thereof.

The amount of the fluorine resin contained in the elastic resin layer is 1 to 10 parts by weight based on 100 parts by weight of the elastic resin. If the amount is less than 1 part by weight, the antifouling property is insufficient and the commercial value is reduced. On the other hand, if it exceeds 10 parts by weight, the antifouling property is very good, but the bending resistance is extremely reduced, the adhesiveness to the base layer is also deteriorated, and it cannot be put to practical use. The amount of the silicone resin added to the elastic assembly layer is 0.5 to 5 parts by weight based on 100 parts by weight of the elastic polymer resin. If the amount is less than 0.5 part by weight, the antifouling property is insufficient, and if it exceeds 5 parts by weight, the adhesiveness to the base layer is deteriorated and the commercial value is lost.

Next, as a method of applying a resin for the surface layer containing a fluorine resin and a silicon resin, a known method such as a spray method, a gravure printing method, a printing method, and a transfer method may be used. A gravure printing method is preferable as a method for easily applying the gravure printing method. In order to achieve both the antifouling property and the adhesive property, which are features of the present invention, the shortest distance between a spot and an adjacent spot must be maintained at 10 to 100 microns. If the shortest distance is less than 10 microns, the antifouling property is good, but the adhesion to the base layer is poor. 100
In the case of a micron or more, the adhesiveness is good, but the antifouling property deteriorates. The size of one spot is 100 to 5
00 μm ² is preferred. The coating amount of the surface layer is preferably ² to 5 g / m ² in terms of resin solid content.

In the present invention, a coloring agent may be added to the resin layer used as the base layer or the surface layer. Examples of the coloring agent to be added include pigments and dyes.
As the pigment, an inorganic pigment such as carbon black or titanium oxide, or an organic pigment such as a ferocyanine-based, azo-based or anthraquinone-based pigment is used. Further, as the dye, a gold-containing dye, an acid dye, a sulfur dye, a disperse dye, and the like are used.
A gold-containing dye is desirable in terms of light fastness, 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 and kneading as required. Further, in the present invention, an intermediate layer may be present between the substrate layer and the surface layer, the intermediate layer may be a porous layer, may be a non-porous layer,
As the resin forming the intermediate layer, a polyurethane resin of the same type as the resin forming the base layer and the surface layer is preferable. The intermediate layer may be composed of a single layer or a layer composed of two or more layers. It is preferable that a coloring agent such as a dye or a pigment is added to these intermediate layers. In particular, the surface in contact with the base layer may be a layer made of a two-liquid curable polyurethane, and the layer in contact with the spot-shaped surface layer may be a multilayer intermediate layer made of a polyurethane layer containing a colorant. It is most preferable to achieve the object of the present invention.

The leather-like sheet obtained by the present invention is excellent in antifouling property, and can easily be removed when dirt such as mud, tobacco ash, aqueous pen or aqueous pen / oil pen is attached,
Moreover, it is a leather-like sheet having good water repellency and oil repellency, good texture and excellent adhesiveness. These leather-like sheets are very suitable for use in sports shoes, bags, bags, gloves, general shoes and the like.

[0016]

EXAMPLES Next, the contents of the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. In the examples, parts and percentages relate to weight unless otherwise specified. Example 1 A 6-nylon sea-island composite fiber (multicomponent fiber) comprising 60 parts of nylon (island component) and 40 parts of high-flow low-density polyethylene (sea component) was obtained by melt spinning, and this was melted in hot water at 70 ° C for 2 hours. After stretching by a factor of 5, applying a fibrous oil agent, drying by mechanical crimping, and cutting to 51 mm to form staples having a thickness of 4 deniers, using this fiber with a basis weight of 500 g / m ^{2 by} a cross-lap method. Was formed, then needle punching was performed at about 500 punches / cm ² alternately from both sides, and further heated at 120 ° C. and pressed with a calender roll to produce an entangled nonwoven fabric having a smooth surface.
The basis weight of this entangled nonwoven fabric was 540 g / m ² , and the apparent specific gravity was 0.3. This entangled nonwoven fabric is impregnated with a 18% dimethylformamide (DMF) solution of polyurethane mainly composed of polytetramethylene ether-based polyurethane, immersed in a DMF / water = 15/85 mixed solution, and wet coagulated. The sea component in the composite fiber is eluted and removed in hot toluene to express a 0.1 denier ultrafine fiber,
A fibrous sheet substrate layer was obtained. The obtained fibrous base material layer had a thickness of 1.3 mm and a polyurethane content of 120 g /
m ² . On the other hand, release paper with a grain (LINTEC TP
R-8) as a skin layer as a skin layer of polyether-based polyurethane (ME-8105LP solid content 30 of Dainichi Kagaku Kogyo KK)
%) 100 parts, 30 parts of titanium oxide DUT4093 (Dainichi Kagaku Kogyo Co., Ltd.), 30 parts of DMF, 30 parts of methyl ethyl ketone are applied on a dry base to a thickness of 50 μm, and dried at 100 ° C. for 5 minutes. Then, a skin layer was obtained. A two-component curable polyether-based polyurethane solution is applied thereon to a dry base of 30 μm, dried at 50 ° C. for 3 minutes, then bonded to the above fibrous sheet base layer, and then at 100 ° C. for 2 minutes. After drying, and then left at 40 ° C. for 3 days, the release paper was peeled off to obtain a leather-like sheet. A solution of a polycarbonate-based polyurethane containing 5% of a perfluoroalkyl group-containing polyacrylate and 2% of dimethylpolysiloxane (100% modulus of polyurethane: 80 kg / cm)
² ) was replaced with a 140 mesh lattice gravure roll (20
(0 line / 1 inch, cell depth 50 microns). The coating amount was 4 g / m ² in terms of solid content, the distance between the spots was 30 μm, and the size of the spot was about 200 μm ² . The obtained leather-like sheet was excellent in antifouling properties, had good adhesiveness, and had a soft texture. This was the best material for sports shoes.

Example 2 50 parts of 6-nylon kneaded with a black pigment was dispersed in a
An entangled nonwoven fabric made of 4-denier multicomponent fibers containing 50 parts of polyethylene as a dispersion medium component was prepared. 450g weight
/ M ² and an apparent specific gravity of 0.26. 18% dimethylformamide (DM) of polyethylene adipate / polyethylene glycol copolymer polyurethane containing black colorant
F) Impregnating the solution, and applying the same type of solution to the surface at 80 g / m ^2.
After knife coating and coagulation of the polyurethane in a 25% DMF aqueous solution, polyethylene in the multicomponent fiber was dissolved and removed to obtain a fibrous sheet substrate layer made of 0.005 denier ultrafine fibers. The obtained fibrous sheet substrate layer has a basis weight of 5
The thickness was 1.3 mm at 00 g / m2. The resin impregnation amount was 120 g / m ² . The skin was treated with a polycarbonate-based polyurethane solution (solid content concentration: 15%) in four steps of 150 mesh with crusher to give a coating amount of 60 g / m ² / wet. Next, a polycarbonate-based non-yellowing polyurethane solution (resin content 15%, 100% modulus 40 kg / cm ² )
100 parts, 2 parts of perfluoroalkenyl ether fluororesin (solid content: 50%), and 1 part of dimethylpolysiloxane silicone resin (solid content: 50%) were mixed and coated with urea. The coating amount was 3 g / m ² in solid content, the distance between the obtained spots was 50 μm, and the size of each spot was 400 μm ² . After that, temperature 150 ℃, pressure 3k
The embossing treatment was performed under the conditions of g / cm and a speed of 2 m / min using an embossing roll of hair creasing. In addition, it was treated to improve texture. The obtained leather-like sheet was excellent in antifouling properties, had good adhesiveness and texture, and was most suitable as a bag or a bag-like raw material.

Comparative Example-1 A leather-like sheet was obtained in the same manner as in Example 1 except that the resin solution for the skin of Example 1 was not applied to the base layer. When this was used as a raw material for men's shoes, the target antifouling property was poor, and there was no commercial value.

Comparative Example 2 A leather-like sheet was obtained under the same conditions as in Example 2 except that the fluororesin was removed from the gravure solution of the surface layer. Although the obtained leather-like sheet had good adhesiveness, the antifouling property was poor and the target product could not be obtained.

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

[0021]

[Table 1]

Antifouling property: Evaluation after wiping of tobacco ash and water-based magic Flex resistance: JIS K6545 Peeling strength: Kuraray method Water repellency: JIS L1092 Oil repellency: DuPont method (determination after using n-hexadecane) sensory test

[0023]

The leather-like sheet obtained by the present invention has good water repellency and oil repellency, and can easily be removed when dirt such as mud, tobacco ash, water-based magic, etc. adheres, and has a good texture. The leather-like sheet was excellent in good adhesiveness. These leather-like sheets are very suitable for use in sports shoes, bags, bags, gloves, general shoes and the like.

Claims (3)

[Claims] 1. A polyurethane resin 100 is coated on the surface of a base layer containing a polymer mainly composed of an elastic polymer in a fiber assembly.
A resin composition containing 1 to 10 parts by weight of a fluororesin and 0.5 to 5 parts by weight of a silicone resin is fixed in a spot shape with respect to parts by weight, and the shortest distance between a spot and an adjacent spot is fixed. A leather-like sheet having a thickness of 10 to 100 microns. 2. The leather-like sheet according to claim 1, wherein a colored polyurethane layer is present between the substrate layer and the surface layer provided in the form of spots. 3. The polyurethane resin used for the surface layer applied in the form of a spot has a 100% modulus of 10 to 10.
The leather-like sheet according to claim 1 which is 80 kg / cm ^2.