JPS6320948B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a grain layer made of densely intertwined fibers and resin, and has a clear and deep color tone.
The present invention relates to silver-finished artificial leather that can be dyed robustly.

Conventionally, on a porous substrate containing a resin such as a polyurethane elastomer in a fiber aggregate such as a nonwoven fabric, a porous or non-porous substrate made of a resin such as a polyurethane elastomer of the same type or a different type as that used for the substrate has been used. Many proposals have been made regarding the so-called silver-covered artificial leather, which has a grain layer formed from a layer of , or a layer formed by laminating a porous layer and a non-porous layer. However, in such silver-covered artificial leather, in order to obtain a grain layer that closely resembles the fine collagen fibers of natural leather that are densely intertwined, elastic polymers, etc. are added to the grain layer as described above. Using a resin consisting of
By devising the structure of the resin or simply combining the resin layers, a silver surface layer similar to natural leather is formed, so it has a poor sense of unity, a strong rubber-like repulsion, and is free from scratches. It had drawbacks such as being easy to stick to, and having a uniform surface gloss with no depth of luster.

The present inventors have developed a silver-finished artificial leather that improves these drawbacks and is equivalent to natural leather, or even overcomes the drawbacks of natural leather, such as being susceptible to water and cannot be washed, and is superior to natural leather. First, we begin with a thorough analysis of natural leather.
By making full use of chemical fibers with excellent scientific and physical properties, it has a particularly vivid, deep color and deep luster, and has excellent durability such as bending resistance and resistance to rubbing, and is washable. As a result of intensive study on possible silver-finished artificial leather, we finally arrived at the present invention.

That is, the present invention provides a silvered artificial leather having a silver surface layer on at least one side, which is made of ultrafine fibers made of polyamide containing 6.5 to 15 x 10 ^-2 mol of amino groups per 1 kg of fiber at the molecular terminals. furthermore, the grain layer is composed of the ultrafine fibers and/or
Alternatively, the present invention relates to a silver-covered artificial leather characterized in that the bundle is formed of a composite material mainly consisting of a resin and a densely intertwined fiber structure with a distance between fiber entanglement points of 200 microns or less.

The silver-covered artificial leather of the present invention is formed as a composite in which the grain layer is composed of a fiber structure in which ultrafine fibers and/or bundles thereof are densely intertwined, and a resin present in the voids and/or the upper part of the fiber structure. Furthermore, it is based on the use of highly dyeable polyamide for the ultra-fine fibers, and by this combination, it is possible to obtain vivid and deep color tones, and it is also highly durable. It has now become possible to provide silver-finished artificial leather that is washable and is as good as natural leather.

The ultrafine fiber used in the present invention is
It consists of a polyamide with 6.5 to 15 x 10 ^-2 moles of terminal amino groups. Conventionally, ultrafine fibers have been preferably used for such artificial leather, regardless of the silver type or suede type, in order to obtain a flexible texture, and polyester and polyamide have generally been used for such ultrafine fibers. .

However, as the microfibers become thinner, the surface area of the fibers also increases, and the amount of light reflected on the surface increases, resulting in decreased color development and the fineness of the microfibers.
This tendency is especially strong when it comes to 0.2 denier or less.
It was difficult to dye it in a deep color. Moreover, even if a deep color is obtained, its fastness cannot necessarily be said to be good. Furthermore, in particular, artificial leather made of ultrafine polyamide fibers does not have good dyeability, so its cross section is often white and unsightly.

The polyamide that forms the ultrafine fibers of the present invention differs from ordinary polyamides in that it has a terminal amino group content of 2 to 5 times that of those of ordinary polyamides, that is, the content of terminal amino groups per 1 kg of fiber at the molecular ends.
It is a highly dyeable polyamide containing 6.5 to 15 x 10 ^-2 moles of amino groups.

If the terminal amino group content is less than 6.5 x 10 ^-2 moles, sufficient dyeability cannot be obtained, and it is difficult to dye the silver-covered artificial leather obtained using it in a deep color. On the other hand, in order to have a terminal amino group content of 15 x 10 ^-2 mol% or more, it is necessary to considerably reduce the degree of polymerization of the polymer, and in such a case, the spinnability is poor and the formation of the ultrafine fibers is impaired. It becomes difficult. Terminal amino group content is 6.5 to 1 kg of fiber
15×10 ^-2 mol, preferably the amino group content is 7.0
By using ~8.5×10 ^-2 mol of ultrafine fibers,
For the first time, it is possible to obtain silver-covered artificial leather that can have a clear, dark, and glossy hue that matches the color tone of the resin used in the silver surface layer. Also,
In the silver-covered artificial leather of the present invention, the ultrafine fibers made of the polyamide are present throughout the silver-covered artificial leather, so the entire surface can be uniformly dyed, and its cross section can also be made unsightly.

The fineness of the ultrafine fibers constituting the silvered artificial leather of the present invention is preferably 0.2 denier or less, particularly 0.05 denier or less, since the effects of the present invention can be effectively exhibited. If the fineness is thicker than this, the rigidity of the fiber will be too high, which will not only impair the flexibility of the grain layer and the form of wrinkles on the surface, but also cause cracks to occur easily when rubbed.
This is not preferred because it is difficult to obtain a smooth and durable grain layer, and it is also impossible to sufficiently increase the intertwining density of the fibers. By using ultrafine fibers of 0.2 denier or less, the intertwining of the fibers can be extremely dense, and when a grain layer is formed as a composite with resin, cracks are less likely to occur and a smooth touch is achieved. This is preferable because silver-finished artificial leather having the following characteristics can be obtained.

Now, the structure of natural leather is coiled.
It is already well known that the thin collagen fibers of a book are twisted spirally to form a bundle, and that these bundles are further connected to form a network structure called the reticular layer. The silver layer is
As mentioned earlier, extremely fine collagen fibers are tightly intertwined, giving each type of animal a unique texture. Therefore, such an elegant twill and luster cannot be obtained with the grain layer formed only from a mere resin layer in conventional grain-finished artificial leather. In addition, methods have been proposed in which a resin layer is simply integrated with a structure in which ultrafine fibers or bundles thereof constituting the substrate are arranged in a plane, or in which the fluff fibers on the surface of the substrate are integrated. When subjected to scratching, rubbing, repeated shearing force, etc., the surface tends to become fluffy or cracked, and deep gloss cannot be obtained.

In order to obtain such an elegant twill and luster, it is necessary to use the above-mentioned ultrafine fibers, intertwine the ultrafine fibers and/or their bundles closely, and form a grain layer as a composite with a resin. That is, the fiber structure in the grain layer requires that ultrafine fibers and/or bundles thereof are tightly intertwined with each other. That is, the fiber entanglement density must be high. One method to measure the intertwining density of fibers is to measure the distance between fiber intertwining points described below, but the fibers in the grain layer have an intertwining density of 200μ or less when measured using this method. It is necessary to be present.

The distance between fiber entanglement points is a value determined by the following method, and is a measure of the denseness of intertwining of fibers, and the smaller the value, the more dense the entanglement. The figure is an enlarged schematic view of the constituent fibers in the grain layer when observed from the surface side. The constituent fibers are f ₁ , f ₂ , f ₃ ..., and the point where any two fibers f ₁ and f ₂ intertwine is a ₁ , and the fiber f ₂ on top at a ₁ is another fiber. Trace to the point where they intersect in a manner that is below them, and let that point be a ₂ (intersection point of f ₂ and f ₃ ). Similarly, a ₃ , a ₄ ,
a ₅ ...... Next, the linear horizontal distances between the intersecting points obtained in this way are a ₁ a ₂ , a ₂ a ₃ , a ₃ a ₄ , a ₄ a ₅ , a ₅ a ₆ ,
Measure a ₆ a ₇ , a ₇ a ₃ , a ₃ a ₈ , a _{8 a 7} , a 7 a ₉ , a ₉ a ₆ ..., find the average value of these many measured values, and calculate this as the fiber entanglement point. The distance between

In this way, similar to the fiber structure in the grain layer of natural leather, the highly dyeable ultrafine fibers described above are used to create a densely intertwined structure, and the densely entangled structure and resin are integrated into a composite structure. By doing so, it is possible to obtain the same elegant twill and deep luster as natural leather. Furthermore, since the fibers are densely intertwined, the surface does not become fuzzed easily, and durable silvered artificial leather with excellent scratch resistance and resistance to rubbing can be obtained.

Furthermore, as for the fibers constituting the lower layer of the grain layer of the silver-covered artificial leather of the present invention, it is necessary to mainly use the highly dyeable ultrafine fibers in order to obtain a soft and clear dark color tone. This fiber structure is not particularly limited, and may be, for example, a non-woven structure of the ultrafine fibers, or a structure in which a knitted or woven fabric is inserted into the non-woven structure and integrated into an inseparable structure. In particular, the structure of the lower layer is mainly an entanglement of the ultrafine fiber bundles, and the ultrafine fibers and/or their bundles of the grain layer are branched and more densely intertwined of the ultrafine fiber bundles of the lower layer. A sheet with a fiber structure in which the fibers are substantially continuous in the grain layer and the lower layer, and the degree of branching changes continuously at the boundary between the two layers has a unified texture. This is preferable because a product can be obtained and the grain layer and the lower layer will not peel off.

Further, the structure of the lower layer is a three-dimensional entangled structure in which the ultrafine fiber bundle and the ultrafine fibers branched from the bundle are densely intertwined with each other, and the fibers of the lower layer and the fibers of the grain layer are substantially A structure in which the two layers are continuous and the degree of entanglement of the boundaries between the two layers continuously changes is more preferable because even higher strength can be obtained.

Examples of the resin constituting the grain layer of the present invention include polyamide, polyester, polyvinyl chloride, polyacrylate copolymer, polyurethane, neoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyamino acid, and polyamino acid. Synthetic resins such as polyurethane copolymers, silicone resins, natural polymer resins, or mixtures of these resins can be used, but polyurethane containing tertiary nitrogen in the molecule is even better. It is preferable because it gives a deep luster and deep luster. For such polyurethanes, for example, a compound containing tertiary nitrogen (such as N-methyl-amino-bis-propylamine) is used as part of the extender and reacted with a high molecular weight chemical having an isocyanate group at the end. It can be obtained by Further, the polyurethane may be synthesized from polyisocyanate containing nitrogen, and there are no particular limitations on the method for producing such polyurethane, and it can be obtained by a number of methods.

The method for producing the silver-finished artificial leather of the present invention will be described below. First, the highly dyeable polyamide that makes up the ultrafine fibers is, for example, the well-known PNC
It can be obtained by ring-opening polymerization of ξ-caprolactam synthesized by the method and end-blocking with hexamethylene diamine.

Next, using the spinning device described in, for example, Japanese Patent Publication No. 34-10497, the above-mentioned polyamide is used as the ultrafine fiber component, and polystyrene, for example, is used as the bonding component.
Ultrafine fiber-forming fibers are formed using a copolymer of styrene and a higher alcohol ester of acrylic acid and/or a higher alcohol ester of methacrylic acid.

For example, it may be produced directly using methods such as Super Doro or melt blowing, but as the fibers become thinner, spinning becomes unstable and processing is difficult and difficult to handle. It is preferable to convert the fibers into ultrafine fibers at an appropriate stage during the process. For example, fibers made of ultra-fine fibers immediately after spinning and partially glued together into a single fiber, fibers with a chrysanthemum-shaped cross section in which one component is interposed radially between other components, multilayer bimetallic fibers, and fibers with a donut-shaped cross section. Multilayer bimetallic fiber, sea-island mixed spun fiber made by melt-mixing and spinning two or more components, a large number of ultra-fine fibers that are continuous in the fiber axis direction, arranged and aggregated, and bound and/or partially bound by other components to make a single fiber. The ultrafine fibers are formed by dissolving and removing the bonding components of the polymer mutually arranged fibers and the like with a solvent at an appropriate stage. Thereafter, the ultrafine fiber-forming fibers are stapled, passed through a card and a cross wrapper to form a web, and further needle punched to entangle the ultrafine fiber-formable fibers to form a fiber sheet. Alternatively, following the spinning of the microfiber-forming fibers, they are stretched and placed randomly on a wire mesh, and the obtained web is needle punched in the same manner as described above to form a fiber sheet. Alternatively, the ultrafine fiber-forming fibers may be placed on a woven or knitted fabric made of ordinary fibers or other ultrafine fiber-forming fibers, entangled and three-dimensionally entangled to form an inseparable unit to form a fiber sheet. .

Next, the fiber sheet thus obtained is brought into contact with a high-speed fluid stream using a nozzle with a small hole diameter or slits with narrow intervals, so that the portion corresponding to the grain layer is branched into ultrafine fibers and/or bundles thereof. At the same time, carefully intertwine. The fluid referred to here is a liquid or a gas, and in special cases it may contain extremely fine solids, but water is the most suitable in terms of ease of handling, cost, and amount of collision energy as a fluid. Preferably used.

The pressure applied to the liquid varies depending on the ease with which the ultrafine fiber-forming fibers or ultrafine fiber bundles branch.
A relatively low pressure of 100 Kg/cm ² may be sufficient, but for fibers that are difficult to branch, a high pressure of 100 to 300 Kg/cm ² is preferred. Furthermore, it is possible to increase the degree of branching and entanglement by increasing the number of contacts.
The pressure may be varied with each contact.

Thereafter, the resulting fiber sheet is treated with a solvent that dissolves some of the components of the microfiber-forming fibers to dissolve and remove some of the components. However, the ultrafine fiber-forming fiber is not particularly limited to being subjected to the ultrafine process after being treated with a high-speed fluid stream, and some of the components may be dissolved and removed before being treated with a high-speed fluid stream.
In this case, the ultrafine fiber-forming fibers of the fiber sheet have been transformed into bundles of ultrafine fibers by dissolving and removing some of the components, so that they can be easily and highly branched and entangled with low fluid pressure. This is a preferred method because it can be done. Further, high-speed fluid flow treatment may be performed before and after the step of dissolving and removing the partial components. Furthermore, it is particularly preferable to dissolve and remove some of the components after applying the resin for forming a grain surface and forming a grain surface layer, since a softer texture can be obtained.

In this way, by using high-speed fluid flow to tightly entangle ultrafine fibers and/or their bundles, the sheet-like product has excellent shape retention even without using a resin such as polyurethane elastomer as a binder. If necessary, it may be impregnated with a solution or dispersion of a resin such as a polyurethane elastomer and coagulated by a wet or dry method.

Thereafter, the solution or dispersion of the resin for the grain layer described above is applied to the layer of the obtained fiber sheet in which the ultrafine fibers and/or their bundles are intertwined by reverse roll coating, gravure coating, knife coating, slit coating, or spraying. The fibers and resin are applied by a method such as the above, solidified by a wet or dry method, and the roll or sheet surfaces are pressed together and heated if necessary to integrate the fibers and the resin and at the same time smooth the surface. Here, it is also a preferable method to subject the fiber sheet to a treatment such as pressing to smooth the surface before applying the resin.

The silver-plated artificial leather thus obtained is easily colored using at least one dye selected from commonly used acid dyes, oxidative mordant dyes, metal-containing acid dyes, and reactive dyes. It is possible to obtain artificial leather that is colored in a deep, clear and deep tone over the entire area. In particular, it is preferable to color with a reactive dye because silver-covered artificial leather with good fastness can be obtained.

This coloring method varies depending on the type of dye used, and cannot be generalized, but it may follow a standard method for dyeing using these dyes. It goes without saying that either the dyeing method or the printing method may be used.

As described above, the silver-covered artificial leather of the present invention can be colored vividly and deeply throughout and with good fastness, and the silver surface has an elegant twill and deep luster. It also has excellent durability such as bending resistance and rubbing resistance. Furthermore, the silver-covered artificial leather of the present invention is flexible and highly strong. For this reason, it is preferably used for a variety of purposes, including silver-finished artificial leather for clothing, furniture materials such as chairs and sofas, shoe uppers, handbags, bags, belts, bags, gloves, and ball leather. be able to.

The examples shown below are intended to make the present invention more clear, and the present invention is not limited thereto. In the examples, parts and percentages are by weight unless otherwise specified. In addition, the value of the average intercrossing point distance was taken as the average value of 100 measured values.

Example 1 40 parts of nylon-6 with amino terminals of 8.0 x 10 ^-2 mol per 1 kg of fiber as a microfiber component, and a total of 60 parts of two types of copolymers of acrylic acid and styrene with different viscosities as binding components. Multi-component spinning using a static mixer, in which polymer mutually arrayed fibers are formed in a form in which each filament has 12 island components and a large number of ultrafine fiber components are contained in the island components at a ratio of It was formed using a device.

The number of ultrafine fibers obtained from this polymeric mutually arranged fiber filament was about 700, and the average fineness was 0.002 denier.

Next, the polymeric mutually arranged fibers were drawn and crimped, and then cut into staples. Next, a web is formed through a card cross wrapper, and then needle punched to entangle the fibers of the polymeric mutual array, with a basis weight of 365 g/m ² and a density of 0.18 g/cm ³
A nonwoven fabric was obtained.

Next, from a nozzle with a hole diameter of 0.25 mm and a pitch of 1.5 mm,
Water under a pressure of Kg/cm ² was sprayed into contact with both surfaces of the nonwoven fabric at high speed while moving the nozzle, and the treatment was carried out four times under the same conditions. The obtained nonwoven fabric is
In particular, the surface layer of the polymer mutually arranged fibers was branched into ultrafine fibers or bundles thereof, and had a fiber structure in which they were densely intertwined with each other. The distance between fiber entanglement points on this surface was measured and found to be 55μ.

Next, a prepolymer consisting of polyethylene butylene adipate and hydrogenated diphenylmethane-4,4'-diisocyanate was added to N-methyl-
Chain extension was performed using a mixed extension agent consisting of amino-bis-propylamine and hydrazine, and the resulting polyurethane elastomer solution was applied to a fiber sheet treated with a high-speed fluid stream using a gravure coater so that the solid content was 5 g/m ² The material was then pressed through a heated embossing roll to emboss a leather-like grain pattern.

Thereafter, the bonded components of the polymeric mutual array fibers were almost completely extracted and removed with trichlorethylene.

The sheet-like material thus obtained was dyed using a jet dyeing machine under normal pressure under the following conditions, and finished in a conventional manner.

Dyeing conditions Dye: Irgalam Red Brown RL-200%: 10% owf Dyeing temperature x time: 98℃ x 75min Fixing treatment conditions Fixing agent: Natural tannic acid Fixing temperature x time: 80℃ x 20min Silver-covered artificial leather obtained in this way The entire piece was vividly and deeply colored, its silver surface had an elegant twill and deep luster, and it had a soft and unified texture. When this silver-finished artificial leather is made into a coat, its silhouette has no sharp edges and drape close to the body, and its appearance is so glossy that it is indistinguishable from a natural calf. It was something I had. Moreover, the fastness was good.

Example 2 A 3.5 denier polymer interlayer fiber in the form of 70 ultrafine fibers in one filament with 50 parts of the same highly dyeable polyamide as in Example 1 and 50 parts of polystyrene as the bonding component. A nonwoven fabric was made in the same manner as in Example 1 using a 51 mm piece. The basis weight of this nonwoven fabric is 650g/m ² and the thickness is 3.4
It was warm in mm.

This non-woven fabric is immersed in a 7% aqueous solution of polyvinyl alcohol (hereinafter referred to as PVA) at 80°C, and at the same time as the PVA impregnation, the non-woven fabric is shrunk and dried to remove moisture, then immersed in trichlorethylene, and repeatedly immersed and squeezed. The bonded components of the polymer mutually arranged fibers were extracted and removed and dried. The obtained nonwoven fabric was a nonwoven fabric in which ultrafine fibers were entangled in substantially bundles.

Next, water under a pressure of 50 kg/cm ² was sprayed at high speed on both sides using a nozzle with a hole diameter of 0.13 mm and a pitch of 0.6 mm, and each side was treated a total of 3 times under the same conditions. Branching out at the same time as melting,
Confounded. The final treatment was carried out while vibrating the nozzle, and after removing the PVA, the sample was passed through a mangle while still containing water, and then dried. The surface layer of the obtained nonwoven fabric had a fiber structure in which the original ultrafine fiber bundles were highly branched and densely intertwined.

Next, a prepolymer of a mixed diol of polyethylene adipate and polybutylene adipate and p,p'-diphenylmethane diisocyanate was chain-extended with ethylene glycol, and a very small amount of carbon black was added to the polyurethane obtained. The surface was impregnated with a solution (hereinafter referred to as DMF), the liquid adhering to the surface was removed with a scraper, and then introduced into water and solidified. Thereafter, the remaining PVA and DMF were removed by thorough washing in hot water at 80°C.

Thereafter, the sheet was cut in half using a slicer, and the sliced surface was lightly buffed with sandpaper to fluff the ultrafine fibers. Next, a paint made by adding carbon black and dye to a polyurethane solution is applied to the surface layer of the opposite side treated with a high-speed fluid flow using a gravure coater, dried and pressed to form a composite and give it a texture. I did the kata.

The sheet-like material obtained in this way is dyed with an acid dye.
It was dyed with a jet dyeing machine using Naylosan Blue F-GBL at a dye concentration of 10% owf, fixed with a synthetic fixing agent, and then finished with a conventional finishing process.

The resulting silver-covered artificial leather is colored a clear dark blue throughout, has a texture with a sense of unity with little repulsion, and has fluff on one side of ultra-fine fibers with relatively long piles. One side has an elegant appearance with a deep luster due to the combination of the resin coloring of the silver layer and the high coloring of the ultra-fine fibers, and the textured texture pattern and the rubbed texture produced during the dyeing process. It had a harmonious and elegant texture and was extremely similar to natural leather.

When a sofa was made using the silver-finished artificial leather, the corners were also finished neatly and a smooth curved surface was formed. In addition, even if the surface was scratched with a nail, it would not be easily damaged, the surface film would not peel off as was the case with conventional methods, and even if it did get dirty, it could be easily wiped off with a damp cloth.

Comparative example: Terminal amino group content: 2.0×10 ^-2 mol (1 kg of fiber)
Exactly Example 2 except that the polyamide of
Silver-covered artificial leather was obtained in the same manner as above. This product was colored only pale blue instead of deep blue as in Example 2, and the silver surface was mainly the hue of the colored resin, lacked elegance in luster, and had poor fastness.

[Brief explanation of the drawing]

The figure is an enlarged schematic view of the constituent fibers in the grain layer when observed from the surface side. In the figure, f ₁ , f ₂ , f ₃ , f ₄ , f ₅ and f ₆ are constituent fibers, a ₁ ,
a ₂ , a ₃ , a ₄ , a ₅ , a ₆ , a ₇ , a ₈ and a ₉ indicate intertwining points of the constituent fibers, respectively.

Claims (1)

[Claims] 1. A silver-plated artificial leather having a grain layer on at least one side, the artificial leather has a grain density of 6.5 to 6.5 per kg of fiber.
It is composed of ultrafine fibers made of polyamide containing 15 x 10 ^-2 moles of amino groups at the molecular ends, and the grain layer is dense so that the distance between fiber entanglement points of the ultrafine fibers and/or their bundles is 200 microns or less. 1. Artificial leather with silver, characterized in that it is formed of a composite mainly consisting of an intertwined fiber structure and a resin. 2. The lower layer of the grain layer has ultrafine fibers and/or bundles thereof intertwined with each other, and the fibers in the grain layer and the lower layer are substantially continuous. Silver-finished artificial leather according to item 1. 3. The silvered artificial leather according to claim 1 or 2, wherein the resin forming the grain layer is mainly composed of a polyurethane elastomer containing tertiary nitrogen in the molecule.