JPH01298285A - Production of leathery sheet - Google Patents

Abstract

PURPOSE:To obtain a deep-wrinkly leathery sheet by laminating an elastomeric surface layer on a base layer surface of fibrous sheet having a specified amount of area shrinking capacity followed by press contact on a hot roll with smooth or patterned surface to form uneven wrinkles on said surface layer. CONSTITUTION:A fiber of developing shrinkage by e.g., heat treatment and/or chemical treatment and a nonshrinkable fiber are mutually combined to produce a nonwoven fibrous sheet having 10% area shrinking capacity. One surface of said sheet as a base layer is laminated with a surface layer consisting of an elastomer such as polyurethane-based one followed by coagulation to form a surface layer of (non)porous polymer layer, and after being freed from fluidity, the polymer layer surface is put to press contact with a smooth- or pattern surfaced hot roll or flat plate to effect shrinkage of said fibrous sheet followed by, using a embossing machine, smoothing the projected parts on said sheet along with imparting gloss; thereby obtaining the objective silvery leathery sheet with deep uneven wrinkles good in feel without decreasing moisture permeability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a leather-like sheet having a sufficiently deep uneven surface pattern.

[Conventional technology]

Conventionally, as a method for forming a polyurethane polymer coating film having a surface structure with sufficiently deep irregularities in the shape of a mountain range, a polyurethane polymer solution is applied to a base material such as a film, nonwoven fabric, or knitted fabric, and then a coagulation bath is applied. Japanese Patent Publication No. 48-1 discloses that one polymer is immersed in water, taken out before coagulation of one polymer is completed, and allowed to proceed with coagulation in a coagulation bath that has a swelling effect on one polymer.
No. 8583 also discloses that when a polymer solution such as polyurethane is coated on the surface of a fibrous base material and coagulated in a non-solvent of pentapolymer to produce a sheet-like product having one surface coating layer, By embossing one polymer layer while the coagulation is almost complete but still retains some fluidity, a leather retainer with a dense surface layer and high moisture permeability is created. According to Japanese Patent Publication No. 50-26604, it is possible to obtain a sheet-like material by providing a synthetic resin layer on a base with a thermal shrinkage rate of 2 to 15%, and applying a moist heat rolling process to give it a texture. Japanese Unexamined Patent Publication 1986-42
This is proposed in Publication No. 979.

[Problem to be solved by the invention]

In the production of conventional leather-like sheets, surface embossing patterns are applied to a porous or non-porous surface layer of a polymer applied to the surface of a substrate layer by applying a high temperature sufficient to soften the polymer. Emboss and shape using pressure. Therefore, it is difficult to engrave an embossing roll with a deep uneven pattern or an embossing roll with a complicated pattern with deep unevenness, and furthermore, it is difficult to maintain and manage the embossing roll so as not to damage it. In addition, when attempting to clearly form a deep uneven pattern, a special embossing process is required to prevent the mold from returning, rather than using a method that requires extremely high temperatures and pressures. Furthermore, embossed products have a hard texture and a significant drop in moisture permeability. In addition, artificially engraved patterns result in a uniform and monotonous design, resulting in a material that lacks strength in terms of product design.

Therefore, when attempting to manufacture a sheet material having a surface layer with a sufficiently deep uneven wrinkle surface structure based on the conventional technology, the polymer coagulates in a non-solvent coagulation bath and the coagulation process is not completed. In the method of taking out the polymer and coagulating it in a coagulation bath containing a polymer swelling agent, changing the coagulation bath continuously requires the bath composition of the swelling agent coagulation bath, selection of when to move the coagulation bath, setting management of coagulation conditions, and coagulation. There are many manufacturing difficulties such as the treatment of the swelling agent retained in the subsequent sheet-like material, and further disadvantages such as a decrease in the porosity of the porous surface layer and a decrease in moisture permeability. On the other hand, in the method of performing embossing in the middle of solidification, it is necessary to select the solidification time for embossing and to remove the polymer layer and dirt that have entered the recesses of the embossing roll frequently, and it is complicated and takes a long time. It has drawbacks such as difficulty in continuous production over time. Furthermore, even if the rolling process is performed while applying moist heat, a wrinkle structure with sufficiently deep unevenness cannot be obtained.The present invention has a complex wrinkle structure with sufficiently deep unevenness,
To provide a method for producing a leather-like sheet, which has a surface layer free from artificial uniform monotony, has high moisture permeability, has a soft texture, and is easy to control production conditions.

[Means to solve the problem]

The present invention involves applying or impregnating and applying a solution or dispersion of a polymer mainly composed of an elastic polymer to a fiber sheet having an area shrinkage capacity of at least 100%, solidifying the polymer,
This method of producing a leather-like sheet is characterized in that, at least after the fluidity of the polymer is lost, the fiber sheet is shrunk to form uneven wrinkles on the surface polymer layer.

The present invention also provides a fiber sheet having an area shrinkage capacity of at least 10% or a fiber sheet containing a polymer mainly composed of an elastic polymer, and a porous polymer coating of a polymer mainly composed of an elastic polymer. Alternatively, there is a method for producing a leather-like sheet, which is characterized by applying a non-porous polymer film and then shrinking the fiber sheet to form uneven wrinkles on the surface polymer layer.

Furthermore, the present invention provides a surface polymer layer of a polymer mainly composed of an elastic polymer on one side of a fiber sheet having an area shrinkage capacity of at least 10% or a fiber sheet containing a polymer mainly composed of an elastic polymer. When shrinking the sheet-like material, the fiber sheet is shrunk to form uneven wrinkles on the surface polymer layer, and then the convex portions of the wrinkles are removed using a roll or flat plate with a smooth or patterned surface. to smooth at least a portion of the head of the convex portion. Alternatively, when shrinking a sheet material, the surface of the polymer layer is pressed against a roll or flat plate having a smooth or patterned surface to shrink the fiber sheet, resulting in deep unevenness in the surface polymer layer. This is a method for producing a leather-like sheet characterized by a mixture of smooth parts without wrinkles and parts with deep uneven wrinkles.

The protrusions of the polymer layer formed with deep uneven wrinkles obtained according to the present invention are subjected to embossing treatment with a smooth surface, a mirror surface or a patterned surface, and a solution or dispersion of a gloss-adjusting polymer is applied.
The leather-like sheet of the present invention is a method for producing a leather-like sheet having a different color by applying any or all of the finishing treatments consisting of applying a solution or dispersion of a polymer containing a colorant. A fibrous sheet having an area shrinkage capacity of at least 10% constitutes the base of the sheet.

This is a fiber sheet made using fibers that exhibit shrinkage by subjecting tR fibers to heat treatment (dry heat or wet heat), chemical treatment, or a combination thereof.

Shrinkable fibers are fibers that exhibit shrinkage properties depending on spinning conditions (for example, spinning conditions in high-speed spinning), drawing conditions, modification of fiber-forming polymers (copolymerization, addition of additives), etc. Polyesters such as polymerized polyethylene terephthalate and polybutylene terephthalate, 6-nylon, 6-row nylon,
Polyamides such as 610-nylon and 11-nylon,
Single-component fibers obtained by spinning a polymer selected from polyvinyl chloride, copolymerized polyvinyl chloride, polyethylene, polyglopyrene, copolymerized polyolefin, polyacrylonitrile or acrylonitrile copolymer, or at least two types of polymers. A fiber that changes the fiber form and exhibits contractility by removing one component constituting the fiber from a multicomponent fiber obtained by spinning a combined fiber, or by separating and dividing a multicomponent fiber into components, such as polyester/ Polyolefin, polyester/polystyrene or copolystyrene, polyamide/polyolefin, polyurethane/polyolefin or copolyolefin,
Polyurethane/polystyrene or copolymerized polyolef9
One or more types of zero-shrinkage producing fibers, which are multi-component fibers such as polyester elastomer/polyolefin or copolymerized polyolefin, are selected and the shrinkage producing fiber alone or the fiber sheet is sufficiently shrunk to shrink by at least 10%. An IH fiber web is prepared by mixing expressive fibers and non-shrinkable fibers, and fII obtained by fiber entanglement treatment using needle punching and/or high-pressure water jet treatment.
The fiber entangled nonwoven fabric or the fiber entangled nonwoven fabric is laminated on one or both sides of the fiber web and subjected to a fiber entanglement treatment to form a laminated nonwoven fabric or fiber napped knitted woven fabric, in which the knitted woven fabric and the fiber entangled nonwoven fabric are integrated. The fibrous sheet is subjected to dry heat treatment, wet heat treatment, or chemical treatment to the fibrous sheet and then heat treatment to cause the fibrous sheet to shrink by at least 10 inches in area. Preferably, shrinkage occurs in the range of 17% to 60% in terms of area. If the shrinkage is small, sufficiently deep uneven wrinkles may not be formed or the surface coating polymer layer may not be able to withstand the stress. The desired uneven wrinkles are not formed. On the other hand, if the shrinkage is too large, the deep uneven wrinkles become so dense that not only does the pattern not form, but also the surface layer feels hard. Another method for producing shrinkage of a fiber sheet is to treat a fiber sheet made using multicomponent fibers with a chemical treatment or a combination of chemical treatment and heat treatment to remove one component constituting the multicomponent fibers. By separating and dividing the fiber into fine fiber components, the tension of at least one component constituting the multicomponent fiber is released and contracted.

*The fiber sheet may contain a polymer mainly composed of an elastic polymer to the extent that the shrinkage effect is not hindered.

Examples of the elastic polymer include synthetic elastic polymers or synthetic elastic polymers such as polyurethane distomer, polyacrylate, butadiene-acrylonitrile copolymer, styrene-butadiene copolymer, butadiene-acrylonitrile-styrene copolymer, and polyester elastomer. It is a polymer selected from polymer compositions blended with natural rubber, polyvinyl chloride, vinyl chloride copolymer, polyacrylonitrile, acrylonitrile copolymer, etc.

Further, the surface layer of the leather-like sheet of the present invention is a porous polymer layer or a non-porous polymer layer formed of a polymer mainly composed of an elastic polymer. That is, a solution or dispersion of a polymer mainly composed of an elastic polymer, and optionally additives selected from colorants, thickeners, lubricants, flame retardants, blowing agents, water repellents, crosslinking agents, etc. A polymer composition liquid containing the above is applied to one side of the fiber sheet. Application methods include conventional roll coating, curtain flow coating, and spraying.

Conventional application methods such as surface contact methods are utilized.

The polymer liquid applied to the fiber sheet surface coagulates in the polymer non-solvent. The polymer is solidified by a method such as coagulation by removing the solvent or dispersant by heat, or by coating a solution or dispersion of the polymer on a releasable support, and then solidifying the polymer in a non-solvent of the polymer. Adhering a porous polymer film or a non-porous polymer film of a polymer obtained by solidifying the polymer by coagulating or coagulating by removing a solvent or dispersant with heat to a fiber sheet, etc. A sheet-like product consisting of a fiber sheet and a surface polymer layer is obtained by the method.

The elastic polymer constituting the surface layer is a polyurethane elastomer obtained by reacting a polymer glycol, an organic diisocyanate, and a low-molecular compound having two active hydrogen atoms, a vinyl chloride polymer containing a plasticizer, a plasticized polyamide, and a polyurethane elastomer. and other polymers, or a copolymerized polyurethane distomer.

To treat the uneven wrinkled convex surface of the present invention, a metal roll or metal plate finished with a mirror surface, a smooth surface such as a satin surface, or a patterned surface similar to leather is used. Preferably, it is a metal roll or metal plate that can be heated, but more preferably it is heated to 50°C or higher in a groove where the head of the convex part does not soften or melt and flow, and then the condition of the treated part, e.g. These are metal rolls, metal endless belts, plastic endless belts, gold, and m-plates that can be processed by a heating-cooling method that allows them to be cooled until their gloss, shaping state, etc. do not change.

A sheet-like product consisting of a shrinkable fiber sheet base and a polymer layer is produced by (1) shrinking the sheet-like product by heat treatment using dry heat or wet heat, chemical treatment, or a combination of chemical treatment and heat treatment to increase the surface weight. After forming uneven wrinkles on the combined layer, the convex portions of the surface polymer layer are pressed against a smooth or patterned surface at a temperature and/or pressure at which the polymer can be deformed, and the tops of the convex portions are made glossy. Give. Perform finishing such as smoothing or adding a pattern.

(2) The surface of the polymer layer of the sheet is pressed against a smooth or patterned surface, and if necessary, the fiber sheet is contracted by pressing with protrusions of a desired shape to create deep irregularities in the surface polymer layer. The surface is finished with a mixture of smooth parts without wrinkles and parts with deep uneven wrinkles.

A leather-like sheet is thereby obtained.

The surface condition of the leather-like sheet obtained here will be explained using drawings.

FIG. 1 is a schematic diagram showing the state of uneven wrinkles formed in one polymer layer after the shrinkage treatment of the present invention, where 1 is the concave part of the wrinkle, 2
This is the convex part of the wrinkle. FIG. 2 is a schematic diagram showing a state in which the surface of the uneven wrinkles formed in the polymer layer is heated and pressed with a smooth metal roll to smooth the heads of the convex portions after the shrinkage treatment of the present invention; 1 is a concave portion of the wrinkle, 2 is a convex portion of the wrinkle, and 3 is a portion where the head of the convex portion is smoothed. Figure 3 shows the surface of the polymer layer of the present invention being brought into contact with a smooth metal roll and pressed with a protrusion from the back side of the sheet to shrink the polymer layer, resulting in a smooth surface that does not form deep uneven wrinkles on the polymer layer. 1 is a schematic diagram illustrating a surface state consisting of a surface in which a portion with deep uneven wrinkles is mixed, 1 is a concave portion of the wrinkle, 2 is a convex portion of the wrinkle, and 4 is a surface that is pressed against a smooth surface undergoing shrinkage treatment. This is the smooth surface of the convex part.

The convex portions of the polymer layer with deep uneven wrinkles obtained by the present invention are embossed with a smooth surface, a mirror surface, or a patterned surface. After applying a solution or dispersion, applying a solution or dispersion of a polymer containing a colorant, or applying an easily dyeable polymer, the product may be manufactured by performing a finishing treatment such as dyeing.

〔Example〕

Embodiments of the present invention will be described below using specific examples. Note that parts and parts in the examples refer to weight unless otherwise specified.

Example 1 Polyethylene terephthalate f! with a fineness of 2 denier and a shrinkage rate of 38% in hot water at 75°C. A cross-wrapped web was made by mixing fibers and non-shrinkable polyethylene terephthalate fibers at a predetermined ratio, and the entanglement treatment was performed on both sides using a needle punch at +40=-$ to give a fabric weight of 145 f/n.
Nonwoven fabrics I to ■ with an apparent density of 0.10 l'' and an apparent density of 0.10 l/- were obtained.

Next, apply a polycaprolactone-based polyurethane solution colored with carbon black to the release paper as a polyurethane solution.
After drying, apply a solution of polyoxypropylene-based two-component polyurethane in a solvent solution mainly composed of ethyl acetate in an amount equal to 15 y/d as polyurethane, and remove most of the solvent. After removing it, it was laminated on one side of the nonwoven fabric and left in a room at about 30° C. for about 24 hours to adhere. Thereafter, the release paper was peeled off to obtain sheet materials 1 to 4 having black coating layers. These sheet-like materials 1 to 4 are heated at a temperature of 1
The samples were treated for 2 minutes in a hot air circulation oven at 30° C. to allow free shrinkage, and the results are shown in Table 1.

Table 1 The surface conditions of sheet materials 2 to 4 were as shown in the schematic diagram of FIG. These sheet-like materials 2 to 4 are made by pressing the protrusions of polyurethane against the heating part of an embossing device with a heating part temperature of 160°C and a cooling part temperature of 70°C of an Endren mirror-finished rice grain belt stretched between a heating drum and a cooling drum. and glue
When it was peeled off from the metal belt in the cooling section, as shown in the schematic diagram in Figure 2, the head part (3) of the convex part was smooth and shiny, and the head part (3) of the convex part was smooth and shiny, and the head part (3) of the convex part was smoothed and had no mirror finish. The convex portion (2) had no luster, and was a leather-like sheet with a concavo-convex pattern and a two-tone appearance. This leather-like sheet is used for bags,
It was suitable as a material for belts, etc.

Example 2 When shrinking the unshrinked sheet material 3.4 obtained in Example 1, using the heating/cooling embossing device used in Example 1, the heating part temperature was 150°C, the cooling part temperature was 70°C, Using pressure rolls used to press the sheet-like material against the heating section and rolls with protrusions arranged regularly, the polyurethane surface layer of the sheet-like material is sequentially pressed with the rolls having protrusions on the surface of the metal belt, one part at a time. I performed contractions while holding it down. As shown in the schematic diagram in Figure 3, the obtained sheet-like material has a planar convex part (4) in the part pressed during the shrinkage process, and a deep uneven shape with mountain-like undulations in the other part. Wrinkles had appeared. Easily dyeable polyurethane was gravure printed on the surface of this sheet-like material, and then dyed with red metal complex dye.
The convex parts are a bright maroon color, and the concave parts are a slightly reddish black.

It was suitable as a material for clothing belts, bags, shoes, etc.

Example 3 6-60 parts of multi-component fiber made of 65 parts of nylon (island component) and 35 parts of high-flow polyethylene, 60 parts of multi-component fiber made of 55 parts of polycaprolactone polyurethane (island component) and 45 parts of high-flow polyethylene ( When polyethylene is removed from multicomponent fibers, polyurethane fibers exhibit a shrinkage of 44%). 40 parts of the polyurethane fibers are mixed to form a fiber web, and needle punch entanglement treatment gives a basis weight of 2559/n1', and the apparent density is One piece of nonwoven fabric with a rating of 0.12 to 7/- was obtained.

Next, the sheet was impregnated with a polyester-based polyurethane solution, and then a polyurethane solution consisting of 85 parts of polyester-based polyurethane and 15 parts of polyoxyethylene-based polyurethane was applied in an amount of 4097 d of polyurethane, and coagulated in water to solidify the polyurethane. After that, water was squeezed out to obtain a sheet material impregnated and coated with polyurethane. The surface polymer layer of this sheet-like material has an apparent density of 0.319/lYA.
It was porous. The sheet material was treated in hot toluene to dissolve and remove the polyethylene component of the fibers, and further treated in hot water to azeotropically remove toluene. During this treatment step, the area of the sheet material shrunk by about 29.3%, and the surface polymer layer developed wrinkles in the form of mountain ranges and deep unevenness.

The surface of this polymer layer was embossed with a matte pattern, and then easily dyed polyurethane was applied by gravure. On the other hand, the back side was puffed and fiber-raised with sandpaper to give it a suede look, and then dyed brown with a metal complex dye. The resulting product has a light color in the concave areas on the polymer layer surface;
The convex part had a dark dichroic silver surface, and the back surface had a suede-like surface with raised microfine nylon fibers, making it a product suitable for use as a clothing item.

〔Effect of the invention〕

The non-invention lies in the manufacturing method of a silver-plated leather-like sheet with a surface layer that is wrinkled with deep unevenness that is difficult to make artificially. A deep wrinkle pattern can be obtained without hardening the texture, deteriorating bending resistance, moisture permeability, etc.

[Brief explanation of the drawing]

? Figure J1 is a schematic diagram showing the surface condition of a leather-like sheet with a deep uneven wrinkle pattern on the surface of the present invention.
The figure shows a state in which the head of the convex part of the uneven wrinkle pattern of the present invention is smoothed. FIG. 3 is a schematic diagram showing another surface state of the leather-like sheet according to the present invention, which has a deep uneven wrinkle pattern on its surface.

Claims (3)

[Claims] (1) Applying or impregnating and applying a solution or dispersion of a polymer mainly composed of an elastic polymer to a fiber sheet having an area shrinkage capacity of at least 10%, solidifying the polymer, and improving at least the fluidity of the polymer. 1. A method for producing a leather-like sheet, which comprises shrinking the fiber sheet to form uneven wrinkles on the surface polymer layer after the fiber sheet is lost. (2) On one side of a fiber sheet having an area shrinkage capacity of at least 10% or a fiber sheet containing a polymer mainly composed of an elastic polymer, a porous polymer coating of a polymer mainly composed of an elastic polymer or a non-porous polymer film made of a polymer mainly composed of an elastic polymer A method for producing a leather-like sheet, which comprises applying a porous polymer film and then shrinking the fiber sheet to form uneven wrinkles on the surface polymer layer. (3) A surface polymer layer of a polymer mainly composed of an elastic polymer is provided on one side of a fiber sheet having an area shrinkage capacity of at least 10% or a fiber sheet containing a polymer mainly composed of an elastic polymer. When shrinking the fiber sheet, the surface of the polymer layer is pressed against a roll or flat plate having a smooth or patterned surface to shrink the fiber sheet.
A method for producing a leather-like sheet, characterized in that a smooth part without deep uneven wrinkles and a part with deep uneven wrinkles are mixed in the polymer layer.