JPS6142033B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a leather-like structure. More specifically, the present invention relates to the production of a leather-like structure having good flexibility, antistatic properties, stain resistance, etc., which is made of a fiber base material such as a woven fabric or nonwoven fabric and a rubber-like elastic material such as polyurethane. It is about the method. BACKGROUND ART Conventionally, as a substitute for natural leather, artificial leather mainly consisting of a fibrous nonwoven fabric or a woven or knitted fabric and a polyurethane composition has been known. However, such artificial leather has the disadvantage that it is easily charged with static electricity, and as a result, it attracts dust and the like and is easily soiled. Furthermore, it did not have sufficient flexibility to be used for footwear or clothing. The present inventors have arrived at the present invention as a result of intensive research aimed at obtaining artificial leather that does not have such drawbacks. That is, the present invention provides a method for producing a leather-like structure by applying a solution or dispersion of a rubber-like elastic body to a fiber base material, and then removing the solvent or dispersion medium from the fiber base material by drying. (1) 0.05 to 5.0% of the weight of the fiber base material is added to the fiber base material in advance.
(2) A surfactant having a hydrophilic structure and a lipophilic structure is attached to the solution or dispersion of the rubbery elastic body, and a hydrophilic agent of 0.1 to 5.0% of the weight of the rubbery elastic body is added in advance. Adding a surfactant with a ratio of base molecular weight to hydrophobic group molecular weight of 13 or less; and (3) using a fiber base material to which a solution or dispersion of a rubber-like elastic material has been applied prior to drying the solvent or dispersion medium. This is a method for producing a leather-like structure characterized by immersing it in water for a short time. In the present invention, a water-soluble or water-dispersible surfactant is used as the surfactant that is previously attached to the fiber base material, for example, a woven fabric or a non-woven fabric, but a water-soluble surfactant is preferably used. That is, it should have a hydrophilic structure. Depending on the size of the colloidal particles, water dispersibility may cause woven or nonwoven fabrics to be treated.
Simple dipping makes it difficult to uniformly adhere the surfactant to the inside of woven or nonwoven fabrics. Further, the type of surfactant should be selected depending on the characteristics of the fibers constituting the woven or non-woven fabric; for example, a surfactant having a lipophilic structure that has affinity with the fibers should be selected. Examples of the lipophilic group structure include natural or synthetic chemical structures such as natural oils and fats, polyester, polyether, polyurethane, polyurea, polyvinyl, polyacrylic, polyamide, and polysilica. Hydrophilic group structures include (-CH ₂ CH ₂ O) - _o , -COO, -
Examples include SO ₂ O, =POO, =P, =S, and =N=. The hydrophilic group structure is (-CH ₂ CH ₂ O
) _-o is particularly preferred. The aqueous solution or dispersion of the surfactant is applied to the fiber base material by a dipping method, a spray method, or the like. The amount of surfactant to be attached is 0.05% to 0.05% based on the weight of the fiber base material.
5.0%, preferably 0.1% to 0.8%. Adhesion rate
Above 5.0%, the final product becomes sticky depending on the surfactant used. Alternatively, it is unsuitable because the surfactant tends to bleed onto the surface. If the amount of adhesion is less than 0.05%, it is not preferable because effects such as antistatic properties and improved flexibility, which are the characteristics of the present invention, cannot be obtained. After attaching the surfactant to the fiber base material, the effects of the present invention can be further enhanced by heat-treating the fiber base material using, for example, infrared rays. In the present invention, the surfactant that is added in advance to the solution or dispersion of the rubbery elastic body is one in which the ratio of the molecular weight of the hydrophilic group to the molecular weight of the hydrophobic group (lipophilic group) is 13 or less, preferably 10 or less. The surfactant may be the same as the surfactant attached to the woven or nonwoven fabric described above. However,
Bleeding of surfactants in the final product may occur due to their chemical structure;
The surfactant added should be selected depending on the chemical composition of the rubbery elastomer used. When the molecular weight of the hydrophilic group and the molecular weight of the hydrophobic group of the surfactant exceeds 13, the hydrophilicity of the solution or dispersion is too strong, and the applied rubber-like elastic body shrinks greatly during drying, resulting in a uniform leather. This is not preferable because no structure can be obtained. In the present invention, the value of hydrophilic group molecular weight/hydrophobic group molecular weight is 13 or less and the cloud point is
Particularly preferred is a temperature of 30 to 60°C. The amount of surfactant added is 0.1 to the weight (dry weight) of the rubbery elastic body contained in the solution or dispersion of the rubbery elastic body.
~5.0%. If the amount of surfactant added is less than 0.1%, the softening effect that is the objective of the present invention cannot be obtained, and if the amount added exceeds 5.0%, the hydrophilicity of the solution or dispersion is too strong. For the same reason as above, it is not possible to obtain a uniform leather structure, which is not preferable. In the present invention, a solution or dispersion of a rubber-like elastic body containing a specific surfactant is applied to a fiber base material to which a surfactant has been previously attached as described above, and then a known The method removes the solvent or dispersion medium. In the present invention, if the fiber base material to which the solution or dispersion of the rubber-like elastic body has been applied is immersed in water for a short time before the solvent or dispersion medium is completely removed, the fiber base material itself becomes hydrophilic. Because of this, water quickly penetrates into the fiber base material, resulting in a leather-like structure with particularly excellent fiber and rubber-like elasticity.
It reaches the interface between the body and the water, and has the effect of accelerating the coagulation of the rubber-like elastic material and preventing adhesion between the two. Then, by removing the water and solvent in the fiber base material through a drying process, a leather-like structure with particularly excellent flexibility is obtained. The immersion time in water is preferably 30 seconds or more and about several minutes, and the water temperature is preferably 10 to 30°C. In the present invention, when a water-containing slurry obtained by mixing and dispersing water in an organic solvent (preferably one with a boiling point of 120° C. or less) solution of a rubbery elastic material is used as the rubbery elastic material solution or dispersion, The effect can be more pronounced. This is because when the rubber-like elastic material begins to solidify, the water dispersed in the elastic material is discharged to the outside of the elastic material, causing water to exist at the interface between the fibers and the elastic material. This is because, together with the water that is present, it greatly contributes to the non-bonding effect between the fibers and the rubber-like elastic body. The amount of water mixed and dispersed is based on the weight (dry weight) of the rubbery elastic body contained in the organic solvent solution of the rubbery elastic body.
50-600% is preferred. In order to stabilize the above-mentioned water-containing slurry, it is preferable to introduce up to 25% by weight of polyoxyethylene chains into the molecules of the rubber-like elastic body constituting the water-containing slurry. in this case,
When the fibrous base material provided with the rubbery elastic body is immersed in water, the rate of immersion of water into the fibrous base material becomes faster, and the effect of increasing the coagulation rate of the rubbery elastic body can also be achieved. If the polyoxyethylene chain contained in this rubber-like elastic body exceeds 25% by weight, the hydrophilicity of the rubber-like elastic body becomes too strong, and when drying, water evaporates and the rubber-like elastic body contracts strongly. ,
This is not preferred because it is difficult to obtain a uniform leather structure. According to the method of the present invention as detailed above, a leather-like structure with excellent flexibility, antistatic properties, stain resistance, etc. can be obtained, and this can be used for clothing, sports equipment, interior decoration, etc. It has a wide range of uses as artificial leather. Embodiments of the present invention will be described in detail below. In the examples, all "parts" mean "parts by weight." Examples 1 to 9, Comparative Examples 1 to 7 [Synthesis of rubber-like elastic body (P-1)] Polybutylene adipate (average molecular weight 1720)
A solution of 345.9 parts of polyoxytetramethylene glycol (average molecular weight 1510), 303.7 parts of polyoxytetramethylene glycol (average molecular weight 1510) and 285.2 parts of diphenylmethane diisocyanate dissolved in 250 parts of methyl ethyl ketone was kept at 60°C for 1.5 hours with stirring, and then dissolved in 1,4-butanediol.
A solution prepared by dissolving 65.2 parts of methyl ethyl ketone in 570 parts of methyl ethyl ketone was added thereto, and a chain extension reaction was carried out while maintaining the temperature at 70°C, to finally obtain a 20% polyurethane-methyl ethyl ketone solution. [Synthesis of rubber-like elastic body (P-2)] Polybutylene adipate (average molecular weight 1720)
A solution of 313.4 parts of polyoxyethylene glycol (average molecular weight 1540), 60.0 parts of polyoxytetramethylene glycol (average molecular weight 1510), 275.2 parts of polyoxytetramethylene glycol (average molecular weight 1510), and 286.0 parts of diphenylmethane diisocyanate dissolved in 250 parts of methyl ethyl ketone was stirred for 1.5 hours. The temperature was maintained at 60°C, and then a solution of 65.4 parts of 1,4-butanediol dissolved in 50 parts of methyl ethyl ketone was added, and a chain extension reaction was carried out while the temperature was maintained at 70°C. Finally, a 20% concentration polyurethane-methyl ethyl ketone solution was obtained. Ta. [Synthesis of surfactant (S-1)] Polyoxypropylene glycol (average molecular weight
A solution of 522.7 parts of 2100) and 94.0 parts of diphenylmethane diisocyanate dissolved in 264 parts of methyl ethyl ketone was kept at 50°C for 1.5 hours and then dissolved in polyoxyethylene glycol (average molecular weight 1540).
A solution prepared by dissolving 383.3 parts of methyl ethyl ketone in 403 parts of methyl ethyl ketone was added and kept at 50°C for 1.5 hours to obtain a 60% surfactant-methyl ethyl ketone solution. [Preparation of fiber base material impregnating solution] A solution of surfactant S-1 obtained as described above was added to each solution of rubber-like elastic bodies P-1 and P-2 obtained as described above. were added and mixed in an amount such that the surfactant was 0.8 parts per 100 parts of the elastic body to prepare fiber base material impregnating solutions D-1 and D-2. Separately, a water-containing slurry D-3 was also prepared by mixing and dispersing 25 parts of water to 100 parts of D-2. Furthermore, for comparison, a water-containing slurry D-4 to which no surfactant was added was also prepared by mixing and dispersing 25 parts of water to 100 parts of the solution of P-2. [Creation of fiber base material] Polyethylene terephthalate fiber (thickness: 2.5 denier, length:
25mm), the weight can be reduced by using a flat card.
A web of 200 g/m ² was produced. This web was passed through a needle rocker room and needle punched at 800 needles/cm ³ , and then immersed in warm water at 68° C. for 5 minutes to shrink to 62% of the original surface. This shrink web is immersed in 0.3% soap water (bath soap water), then nipped, and using a belt dryer.
Dry at 130℃ under pressure of 0.1Kg/cm ² , weight 290g/m ² , thickness 1.1mm, apparent density 0.26g/cm ³
A nonwoven fabric F-1 was obtained (soap adhesion amount was 1.0% by weight based on the weight of the fibers). Similarly, the surfactant S
The shrink web was immersed in a 0.3% aqueous solution of S-1 to obtain nonwoven fabric F-2 (the amount of S-1 deposited was 1.0% by weight based on the weight of the fibers). In addition, the above shrink web was immersed in a 0.3% aqueous solution of surfactant S-1, nipped, heated at 180°C for 1 minute with an infrared plate heater, and belt-dried in the same manner as F-2 above. -3 was obtained (S-1 adhesion amount is per fiber weight)
1.0% by weight). For comparison, the shrink web was belt-dried in the same manner as described above without being treated with a surfactant solution to obtain a nonwoven fabric F-4. [Manufacture of leather-like structure] Impregnating liquids D-1, D-2, D-3 and D were added to each of the nonwoven fabrics F-1, F-2, F-3 and F-4.
-4 each, and soak the impregnated nonwoven fabric in water for 2 hours.
It was soaked for a minute and then dried to obtain a leather-like structure. The physical properties of the obtained leather-like structure are shown in Table 1. The various physical properties shown in Table 1 were measured in the following manner. (1) Bending rigidity From the leather-like structure of the present invention, a width of 2.5 cm and a length of
A 30 cm test piece was cut and this test piece was made to protrude from a horizontal table. and the protrusion length l of the test piece
(cm), protrusion angle θ (angle between the extension line of the horizontal plane of the horizontal table and the line connecting the origin of the protruding part of the test piece (the end of the horizontal table) and the tip of the protruding part), weight W
(g/cm ² ) and thickness h under a load of 500g/cm ²
(cm) was measured. The bending rigidity was calculated from the following equation. Bending rigidity = 12·RC/h ³ (Kg/cm ² ) The smaller the value, the softer it is. If the value is 90 or less, it has the same flexibility as natural leather. (2) Surface electrical resistance From the leather-like structure of the present invention, the width is 6 cm and the length is 12 cm.
A test piece was cut out and left in an atmosphere with a temperature of 20°C and a relative humidity of 65% RH for 24 hours. After that, the surface electrical resistance of the test piece was measured at a temperature of 20℃ and a humidity of 65℃.
It was measured in an atmosphere of %RH using an electrical conductivity measuring device for textiles (manufactured by Koa Shokai). The surface electrical resistance value is preferably 1×10 ⁹ Ω or less. As is clear from Table 1, the leather-like structures obtained in Examples 1 to 9 using the method of the present invention were
It has excellent flexibility and antistatic properties. on the other hand,
When a surfactant is not added to the rubbery elastomer solution (Comparative Examples 1 to 3) and when a surfactant is not attached to the fiber base material in advance (Comparative Examples 4 to 7), the resulting leather-like structure is It is hard and has insufficient antistatic properties.

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Claims (1)

[Claims] 1. A method for producing a leather-like structure by applying a solution or dispersion of a rubber-like elastic body to a fibrous base material, and then removing the solvent or dispersion medium from the fibrous base material by drying: (1) A surfactant having a hydrophilic structure and a lipophilic structure is attached to the fiber base material in advance in an amount of 0.05 to 5.0% by weight of the fiber base material, (2) in a solution or dispersion of a rubber-like elastic body. 0.1 to 5.0% of the weight of the rubber-like elastic material in advance.
A surfactant having a ratio of hydrophilic group molecular weight to hydrophobic group molecular weight of 13 or less is added, and (3) a fiber base to which a solution or dispersion of a rubber-like elastic material is applied prior to drying the solvent or dispersion medium. A method for producing a leather-like structure, characterized by immersing the material in water for a short time.