JP2003089986A - Flame-retardant grained artificial leather and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a halogen-free flame-retardant grained artificial leather having excellent flame retardance, suitable for interior fields, especially used requiring the flame retardance such as seats for vehicles and having a soft touch feeling. SOLUTION: This flame-retardant grained artificial leather comprises a grain layer (C) on at least one surface of an artificial leather substrate composed of a nonwoven fabric in which ultrafine fibers (A) having <=0.5 dtex fineness are three-dimensionally entangled and a polymeric elastic body (B) filled in the interior thereof. In the artificial leather, the ultrafine fibers are composed of a copolyester comprising an organophosphorus component copolymerized therewith and aluminum hydroxide is contained in the polymeric elastic body (B). A polyphosphate is added to the grain layer (C).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an ultrafine fiber and a polymer elastic body which are halogen-free and have excellent flame retardancy and which are suitable for the field of interior, especially for applications requiring flame retardancy such as vehicle seats. , A flame-retardant artificial leather with a silver tone having a soft texture.

[0002]

2. Description of the Related Art Recently, synthetic fibers, particularly polyester fibers and polyamide fibers, have been indispensable as materials for clothing and interiors because of their excellent dimensional stability, weather resistance, mechanical properties and durability. Has become. However, depending on the application, it is desired to add further special functions. For example, in the interior field, particularly when used as a upholstery material for seats for railroad cars, seats for automobiles, seats for airplanes, it is extremely important to impart flame retardancy. The field of artificial leather is no exception, and not only the texture and strength physical properties that have been sought for artificial leather as a substitute for natural leather until now, but also the addition of special functions depending on the application, such as flame retardancy described above, is desired. There is.

Conventionally, as a base layer of artificial leather, a cloth having a polymer elastic body in the entangled space of an ultrafine fiber nonwoven fabric has been used. When a resin layer is applied to the surface of this cloth, a so-called silver-like artificial leather is obtained, and when the surface of the cloth is fluffed, so-called suede-like artificial leather is obtained. As a method of imparting flame retardancy to such artificial leather, a method of attaching a flame retardant to the surface of the fiber and the polymer elastic material by a post-processing method, a method of laminating a sheet having flame retardance on the back surface,
A method in which flame-retardant fine particles are kneaded into a thermoplastic polymer which is a raw material for ultrafine fibers is generally used.

Among these methods, the post-processing method has a problem that the texture of the artificial leather is deteriorated due to the fact that the flame retardant is introduced into the base layer having an appropriate void. Further, in the case of a method of laminating a flame-retardant sheet on the back surface, there is a problem that the flame resistance of the front surface and the back surface is different and the texture of the artificial leather is impaired.

When a flame retardant is kneaded into a thermoplastic polymer, a flame retardant containing a phosphorus-based or halogen-based compound as an active ingredient is kneaded into a molding material such as polyethylene, polypropylene, polyethylene-polypropylene copolymer, polystyrene, etc. A method of imparting an effect is generally used. On the other hand, nylon 6, nylon 66, nylon 610
The kneading of the flame retardant into a polyamide polymer such as, or a polyester polymer such as polyethylene terephthalate and polybutylene terephthalate is performed by spinning from the viewpoint of the stability of the flame retardant and the polymer at the melt spinning temperature when forming a fiber. There was a problem in productivity due to restrictions on temperature setting, selection of polymer and flame retardant, etc.

Generally, the ultrafine fiber bundle generating fiber used for producing the artificial leather substrate is obtained by composite spinning or mixed spinning of two or more thermoplastic polymers which are not compatible with each other. When the ultrafine fiber bundle-generating fiber is a sea-island structure fiber, in order to impart flame retardancy to the ultrafine fiber bundle obtained by removing the sea component, impart flame retardancy to the resin used for the island component. do it. To impart flame retardancy in the fiber manufacturing stage, a method of kneading a flame retardant such as an inorganic compound, an organic halogen compound, a halogen-containing organic phosphorus compound, or an organic phosphorus compound during spinning may be considered. There are problems such as deterioration of physical properties. Particularly when ultrafine fibers are targeted, there is a problem that the flame retardant is removed in the ultrafine fiber generation treatment step such as the sea component polymer removal step. Further, use of a halogen-containing compound can give excellent flame retardant performance, but on the other hand, there is a problem that a substance harmful to the human body is generated during combustion. Therefore, the use of a halogen-containing compound is not a preferable method for achieving the flame retardancy of the artificial leather used for the seat of a vehicle.

Further, the above method of kneading the flame retardant into the fiber may be applied when the flame retardant fiber is a fiber having a regular decitex, that is, a fiber exceeding 0.5 decitex, but is extremely thin fiber. Not applicable in case of. For example, in the production of artificial leather, it is preferable that the fineness of the fiber in the substrate is 0.5 decitex or less in order to obtain a soft texture and a natural leather-like fullness, but such an ultrafine fiber is flame retardant. When kneading fine particles,
Due to the relationship between the particle size of the flame-retardant fine particles and the cross-sectional area of the fiber, the physical properties of the fiber are extremely deteriorated, and a product that can be used practically cannot be obtained.
In addition, even when a flame-retardant organic substance or the like is dispersed without deteriorating the physical properties of the fiber, the flame-retardant organic substance will fall off in the sea component removing step that is usually used in the case of micronization. In many cases, the flame retardancy level cannot be achieved.

When an artificial leather having a certain flame retardancy is provided with a resin to serve as a surface skin to obtain a silver-tone artificial leather, the surface of the base layer may be flame-retardant even if the base layer is flame-retardant. In many cases, the artificial leather as a whole becomes flammable as a result by adding a flammable silver surface layer. In particular, when trying to obtain an artificial leather having a small thickness, the ratio of the silver surface layer, which is relatively flammable in the sheet, becomes high. Sex is difficult. Furthermore, it was difficult to obtain a flame-retardant silver-tone artificial leather that can be used as an interior material for vehicles by using only non-halogen flame retardants, which are inferior in performance to halogen flame retardants.

[0009]

DISCLOSURE OF THE INVENTION An object of the present invention is a halogen-free and excellent flame retardant property, and it is a soft material suitable for the interior field, especially for applications requiring flame retardancy and durability such as vehicle seats. An object is to provide a silver-tone artificial leather having a texture.

[0010]

That is, the present invention is
A silver surface layer (C) is provided on at least one surface of an artificial leather substrate composed of a nonwoven fabric in which ultrafine fibers (A) having a size of 0.5 decitex or less are three-dimensionally entangled and a polymeric elastic body (B) filled therein. In the artificial leather with a silver tone provided with, the ultrafine fibers (A) are made of an organic phosphorus component copolymerized polyester,
A flame-retardant silver-tone artificial leather, characterized in that the polymer elastic body (B) contains aluminum hydroxide, and the silver surface layer (C) further contains polyphosphate. , And preferably, the phosphorus atom concentration in the ultrafine fibers (A) is 3
The amount of aluminum hydroxide contained in the polymer elastic body (B) is 000 ppm or more, and the polymer elastic body (B) 10
10 to 200 parts by weight relative to 0 parts by weight, the silver surface layer (C)
The artificial leather with flame-retardant silver containing 3 to 50 parts by weight of a polyphosphate salt with respect to 100 parts by weight of the constituent resin.
Further, in the present invention, polyphosphate is added to a base layer composed of a nonwoven fabric in which ultrafine fibers (A) having a size of 0.5 dtex or less are three-dimensionally entangled and a polymeric elastic body (B) filled therein. When producing a flame-retardant silver-tone artificial leather by adding the silver surface layer (C), the following steps, fiber entanglement consisting of sea-island type multi-component fibers having an organic phosphorus component-containing polyester as an island component. A process for producing a non-woven fabric, a process for filling the non-woven fabric with a polymer elastic body (B) containing aluminum hydroxide, a method for removing sea components in the fiber, etc. The step of converting into a bundle of ultrafine fibers (A) having a decitex or less, the step of applying a resin having a polyphosphate added to at least one surface of the substrate layer to form a silver surface layer, is performed in the order of or Characteristic artificial leather with flame retardant silver It is a method of manufacture.

In this manufacturing method, the single fiber fineness is 0.5.
A bundle of ultrafine fibers having a decitex or less is produced by a conventionally known method. For example, at least one component is composed of at least two types of incompatible polymers, at least one type of polymer is an island component in the cross section, and at least one type of polymer other than that is a sea component By dissolving or decomposing and removing (usually the sea component polymer), or by bonding mechanically or chemically a laminated type ultrafine fiber bundle generating fiber having a cross-sectional shape in which two or more incompatible polymers are joined. It can be obtained by peeling at the interface between the two components by any treatment. In order to set the single fiber fineness of the ultrafine fibers constituting the obtained bundle of ultrafine fibers to 0.5 decitex or less, and particularly 0.2 decitex or less, the fiber cross section is smaller than that of the pasting type ultrafine fiber generating fiber. It is advantageous in the process to use ultrafine fiber-generating fibers having a sea-island structure. Alternatively, a method for directly producing ultrafine fibers such as melt blown may be used. In addition, the above-mentioned steps are only those steps that are essential for producing the silver-tone artificial leather of the present invention, and steps other than these steps may be added. After that, a step of temporarily fixing the non-woven fabric with a sizing material typified by polyvinyl alcohol may be added.

The sea-island structured fiber used in the present invention can be obtained by composite spinning or mixed spinning of two or more types of incompatible thermoplastic polymers. To impart flame retardancy to the ultrafine fiber bundle obtained by removing the sea component from the sea-island structure fiber, the resin used for the island component may be imparted with flame retardancy. The inventors of the present invention, by using an organic phosphorus component copolymerized polyester as the resin of the island component of the sea-island structure fiber used in the present invention, do not cause problems such as spinnability and loss of the flame retardant in the subsequent step, and thus the ultrafine fiber. A flame retardant can be imparted to the base, and by providing a silver surface layer containing a polyphosphate on the substrate obtained by the combination of the polymer elastic body containing aluminum hydroxide as a flame retardant and the ultrafine fibers, Flame retardance required for vehicle interior materials,
It has been found that a silver-tone artificial leather having both durability and soft texture can be obtained. As the organic phosphorus component copolymer resin, a copolymer resin to cellulose, polyester, phenol, etc. is known, but in the present invention, since it is possible to perform melt spinning and satisfies the necessary physical properties as an artificial leather, the organic phosphorus component Component copolyester is used.

In the present invention, the method for producing the polyester copolymerized with an organic phosphorus component is not particularly limited.
A known method for producing an organic phosphorus component copolymerized polyester as described in JP-A-82392, JP-A-55-7888 and JP-B-55-41610 can be used. For example, in the case of the transesterification method of a dicarboxylic acid diester and a diol, a method of adding an organic phosphorus compound in the transesterification reaction, or a method of adding an organic phosphorus compound before the polycondensation reaction or in the initial stage of the reaction can be adopted. Even if the esterification method of dicarboxylic acid and diol is used, a method of adding an organic phosphorus compound in any esterification reaction step can be adopted. As the organic phosphorus compound used in the reaction, known phosphorus atom-containing compounds such as oxaphospholane, phosphinic acid derivatives, and phosphaphenanthrene derivatives as mentioned in the above publications can be used.

When this organic phosphorus component copolymerized polyester is used, since the phosphorus component is copolymerized, that is, bonded to the polymer by a covalent bond, the flame retardant may be removed during spinning and in various steps of manufacturing artificial leather thereafter. No trouble occurs. In addition, it is possible to avoid the use of halogen-containing compounds, which have been avoided due to recent environmental circumstances. At this time, it is preferable that the organophosphorus component copolyester has sufficient strength physical properties as a fiber, has a higher melt viscosity and a lower surface tension than the sea component polymer under spinning conditions, and is melt-spinnable. It is preferable. For example, the melt flow rate at the spinning temperature measured with an orifice diameter of 2 mmφ and a load of 325 g is 5 to 50, and the fiber strength is 1.
Resins that are 0-5.0 g / decitex are preferred. Further, the phosphorus atom concentration in the organic phosphorus component copolymerized polyester is preferably 3000 ppm or more and 20000 ppm or less, and particularly preferably 5000 ppm or more and 15000 ppm or less. If it is less than 3000 ppm, satisfactory flame retardancy cannot be obtained when the artificial leather is used. 20,000
If it exceeds ppm, the productivity of the sea-island structure fiber deteriorates due to the decrease in the viscosity of the resin, making it difficult to use.

On the other hand, as the sea component polymer, the island component polymer has a different solubility or decomposability in a solvent or a decomposing agent (greater solubility or degradability than the island component polymer), and compatibility with the island component polymer. Use a resin with a small value. For example, at least one polymer selected from polymers such as polyethylene, polystyrene, polyethylene propylene copolymer, and modified polyester obtained by copolymerizing sodium sulfoisophthalate can be used. Polyethylene and polystyrene can be easily extracted with toluene or trichlene, and polyester modified with sodium sulfoisophthalate can be decomposed and removed with an alkali. By extracting or decomposing and removing the sea component from this sea-island structure fiber, the sea-island structure fiber can be converted into an ultrafine fiber bundle. In the present invention, the sea-island structure fiber may have a sea component divided into a plurality of island components in the cross section of the fiber. For example, the sea component and the island component are each in a layer, and are in a laminated state. Such fibers may be used. The island components may be continuously connected in the fiber length direction or may be discontinuous.

Further, the number of islands in the fiber cross section of the sea-island structure fiber is not particularly specified, but it is necessary to set so that the single fiber fineness becomes 0.5 decitex or less after conversion into an ultrafine fiber bundle. Examples of the method for producing the sea-island structured fiber used in the present invention include various melt spinning methods (chip blending method, needle pipe method, laminating method, etc.). The weight ratio of the sea component and the island component constituting the sea-island structure fiber used in the present invention is preferably in the range of 8: 2 to 2: 8. In the present invention, the thickness of the ultrafine fibers constituting the ultrafine fiber bundle formed after removing the sea component polymer from the sea-island structure fibers is 0.5 decitex or less, which is a soft texture and a natural leather-like fullness. In order to obtain the above, it is preferable that the range of 0.001 to 0.2 decitex is particularly preferable. In addition to the above-mentioned organic phosphorus component copolymerized polyester, a colorant such as a dye or a pigment and various stabilizers may be added to the island component of the fiber.

In the present invention, the flame-retardant agent is also included in the elastic polymer. When the elastic polymer is filled inside the sea-island fiber entangled nonwoven fabric, the nonwoven fabric is immersed in a liquid composition containing the elastic polymer, and then the nonwoven fabric is immersed in a coagulation bath to form a polymer. A method of solidifying an elastic body, a method of heating an elastic polymer emulsion liquid into a gel, or the like is used. In order to incorporate the flame retardant into the elastic polymer, it is sufficient to disperse the flame retardant in the liquid composition with which the nonwoven fabric is impregnated.

As the flame retardant to be dispersed in the polymer elastic material, known flame retardants generally used for resins, for example, halogen-based, phosphorus-based, nitrogen-based organic flame retardants, metal hydroxides, Red phosphorus, silicon-based inorganic compounds, etc. are conceivable, but they do not accelerate the deterioration of the polymer elastic body and the ultrafine fibers, and, in the treatment step of the present invention, the treatment liquid in the coagulation bath or the ultrafine fiber generation step It is required that they are not substantially dissolved or decomposed. In addition to these conditions, it is dispersed in a polymer elastic body, and an artificial leather substrate is prepared by combining it with the ultrafine fibers composed of the above-mentioned organic phosphorus component copolymerized polyester, and earnest research is conducted from the viewpoint of the effect expression temperature when burning. As a result, it was found that aluminum hydroxide, which is one kind of metal hydroxide, is the most suitable. Here, the amount of aluminum hydroxide is preferably 10 to 200 parts by weight, more preferably 30 to 100 parts by weight, based on 100 parts by weight of the elastic polymer. 1 aluminum hydroxide
If it is less than 0 part by weight, sufficient flame retardancy cannot be obtained when it is used as an artificial leather substrate, and if it exceeds 200 parts by weight, it becomes difficult for the polymer elastic body to sufficiently retain aluminum hydroxide.
Further, considering the dispersion stability in the impregnating liquid and the flame retardant effect, aluminum hydroxide fine particles having an average particle size of 2 μm or less, particularly 1 μm or less are preferable. The aluminum hydroxide particles may be subjected to various treatments for improving performance such as moisture resistance, heat resistance, water resistance, and acid resistance, if necessary.

The elastic polymer may be at least one selected from diols having an average molecular weight of 500 to 3000, such as polyester diols, polyether diols and polycarbonate diols, or composite diols such as polyester polyether diols. Polymer diol, at least one diisocyanate selected from aromatic, alicyclic, and aliphatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, ethylene glycol, isophorone Examples include polyurethanes obtained by reacting at least one kind of low molecular weight compound having two or more active hydrogen atoms such as diamines with a predetermined molar ratio and modified products thereof, and polyesters. Other examples include elastomers, elastic polymers such as styrene-isoprene block copolymers-hydrogenates, and acrylic resins. A polymer composition obtained by mixing these may also be used. However, flexibility, elastic recovery,
The above-mentioned polyurethane is preferably used from the viewpoint of the porous polymer elastic body forming property and durability.

A polyurethane resin or an acrylic resin is preferably used as the resin for applying the silver surface layer, and a polyurethane resin is more preferably used, which is the same as the impregnating polyurethane described above. Similarly, a known material may be used, and another resin may be appropriately mixed. Since durability is required for many applications in recent years, it is more preferable to use a polyurethane or a polyurethane having excellent durability such as a polyether type or a polycarbonate type.
The hardness of polyurethane is preferably such that the modulus at 100% elongation is in the range of ²⁰ to 150 kg / cm ² . If it is less than 20 kg / cm ² , sufficient strength as an epidermis cannot be obtained, and if it exceeds 150 kg / cm ² , the texture of the artificial leather as a whole becomes hard and the creases are unnatural and rough.

In the present invention, the addition of the flame retardant to the silver surface layer can be achieved by mixing the polyurethane with the flame retardant in any of these processing methods. It is preferable to add it to a layer below the outermost surface layer, for example, the intermediate layer and / or the adhesive layer from the viewpoint of imparting a flame retardant effect while maintaining the surface physical properties. When the silver surface layer is applied by the dry surface forming method, it is preferable to add the flame retardant only to the adhesive layer or the intermediate layer without adding the flame retardant to the outermost surface layer. As the flame retardant added to the silver surface layer, a non-halogen flame retardant is used for the purpose of the present invention. As the non-halogen flame retardant, it is possible to use a known non-halogen flame retardant such as phosphorus, metal hydroxide, silicon, and nitrogen.
For example, when adding a phosphate ester flame retardant,
Although flame retardancy is achieved, bleeding of the flame retardant significantly impairs the surface feel and appearance of the surface, so a practical product cannot be obtained. Also, the same aluminum hydroxide as that contained in the base layer is added. In this case, since a relatively large amount is required, the handling property as an adhesive is hindered and the surface properties such as peel strength are also adversely affected. Also,
Even when a silicon-based flame retardant is used, the same problem as in the case of aluminum hydroxide occurs. Further, when it is added to the skin to increase the concentration of the flame retardant, there are problems such that the surface feeling becomes rough and the physical properties of wear are deteriorated. As a result of the inventors' earnest research on a flame retardant which does not cause these problems in combination with the above-mentioned base layer, polyphosphonate, which is one of the inorganic flame retardants, is contained in the silver surface layer in a relatively small amount. It has been found that the addition of the above can make the entire artificial leather sheet flame-retardant without causing bleeding and adversely affecting the physical properties. The polyphosphate salt is not particularly limited, but ammonium polyphosphate and sodium polyphosphate are used.

First, an ultrafine fiber-generating sea-island structure fiber staple using an organic phosphorus component copolymerized polyester as an island component is manufactured by the above-described known method. As the fiber, a fineness of 1 to 10 decitex is preferable from the viewpoint of ensuring good card passage, and more preferably 3 to 6 decitex. Next, the sea-island structure fiber staple is defibrated with a card, a web is formed through a webber, the obtained web is laminated to a desired weight and thickness, and then a known method such as a needle punching method or a high pressure method. The entanglement treatment is performed by a hydroentanglement treatment method or the like to obtain a nonwoven fabric, or the knitted or woven fabric on which the staples are superposed is entangled using a water flow or the like to obtain an entangled nonwoven fabric. The non-woven fabric needs to have a shape suitable for the purpose in consideration of the thickness of the artificial leather substrate and the like.
The range of 0 g / m ² and the thickness of 1 to 10 mm is preferable from the viewpoint of easy handling during the process. If necessary, a non-woven fabric produced by the above method may be provided with a polyvinyl alcohol-based sizing agent or the surface of the constituent fibers may be melted to bond the constituent fibers of the non-woven fabric to temporarily fix the non-woven fabric. You may go. By performing this treatment, it is possible to prevent the structural destruction of the nonwoven fabric due to tension or the like in the subsequent step of impregnation with the elastic polymer solution or the like.

Next, a nonwoven fabric is impregnated with a polymer solution obtained by dissolving or dispersing the above-mentioned elastic polymer containing aluminum hydroxide in a solvent or a dispersant, and treating it with a poor solvent for the resin. The sea-island structure fiber and the polymer elastic body are formed by a method such as wet coagulation to form a porous polymer elastic body layer, or heat-drying and gelation to form a porous polymer elastic body phase. To obtain a sheet composed of. Additives such as colorants, coagulation regulators, antioxidants and dispersants may be added to the polymer solution as required.

Next, the sheet composed of the sea-island structure fiber and the polymer elastic material is treated with a drug which is a poor solvent for the island component polymer and the polymer elastic material and a solvent or a decomposing agent for the sea component polymer. By doing so, the sea-island structure fibers are converted into ultrafine fiber bundles. In this step, most of the aluminum hydroxide particles in the elastic polymer remain in the elastic body in a state where they do not easily fall off. The proportion of the elastic polymer in the sheet after removal of the sea component is 10% or more, preferably 30 to 50% by weight as a solid content.
If the elastic body ratio is less than 10%, a dense porous polymer elastic body is not formed, and the aluminum hydroxide particles are likely to fall off after the generation of the ultrafine fibers. In the present invention, the ultrafine fibers formed by removing the sea component from the sea-island structure fibers have a fineness of 0.5 because a substrate having a soft feeling can be obtained.
The following decitex is used.

The flame-retardant artificial leather substrate produced in this way is a combination of ultrafine fibers of an organic phosphorus component copolymerized polyester and a porous polymer elastic body holding aluminum hydroxide particles. Although it is difficult to theoretically prove that this combination is optimal, a combination of polyester fiber containing no flame-retardant component and porous polymer elastic body holding aluminum hydroxide particles, or organic phosphorus component The combination of the ultrafine fibers of the copolyester and the porous polymer elastic body not containing aluminum hydroxide cannot make the entire sheet flame-retardant even if the concentration of one flame-retardant component is made as high as possible. In a composite material such as this sheet, it is effective to have a flame-retardant component in each constituent element, and details cannot be confirmed.However, due to the combustion suppression mechanism by the carbonized film formation of the organophosphorus compound and the heat absorption of aluminum hydroxide. It is estimated that the combustion suppression mechanism exerts a synergistic effect by suppressing combustion at multiple points in the combustion process.

As a method of applying a flame retardant to a fiber sheet, a method of impregnating the sheet with a liquid containing a flame retardant and drying it is generally used. In the case of such a method, fibers are extra fine fiber bundles. When the flame retardant is fine particles, the flame retardant hardly penetrates into the inside of the ultrafine fiber bundle, and most of the flame retardant exists on the outside of the fiber bundle or the outer surface of the polymer elastic body. In such a state, the flame retardant is easily dropped off, and a durable flame retardant effect cannot be obtained. In order to prevent the flame retardant from falling off, there is also a method of kneading the flame retardant in the binder resin and impregnating the sheet with this binder resin liquid.However, even if such a method is used, it penetrates into the ultrafine fiber bundle. In addition, since the flame retardant is covered with resin, the flame retardancy is greatly reduced, and since the sheet is also filled with the resin, the flexibility of the sheet is impaired.
In the case of the present invention, such a drawback does not occur.

A silver surface layer containing a flame retardant is provided on at least one surface of the flame-retardant artificial leather substrate obtained as described above to obtain the flame-retardant silver-tone artificial leather of the present invention. In general,
Examples of the method for applying the silver surface layer to the artificial leather substrate include, for example, a method in which a resin layer containing polyurethane as a main component is coated on the surface of the substrate layer with a gravure coater, and then pressure-pressed with a heating embossing roll. A so-called dry surface-forming method in which a resin film patterned on the surface with release paper is adhered, a resin solution mainly composed of polyurethane is coated on the base layer, then wet coagulated in a poor solvent of polyurethane, and gravure coating is applied on this. , A method of embossing embossing, and the like. The application of the silver surface layer containing the polyphosphate in the present invention can be achieved by preliminarily mixing the polyphosphate with the polyurethane in any of these processing methods. Considering the deterioration of the surface properties due to the presence in the layer, a method in which the flame retardant is added to the adhesive layer in the dry surface forming method and not added to the resin film layer serving as the skin is preferable. The amount of polyphosphate added is 3 to 5 relative to 100 parts of the resin solid content including the skin layer and the adhesive layer.
It is 0 part, and preferably 5 to 30 parts. If it is less than 3 parts, sufficient flame retardancy cannot be obtained, and if it exceeds 50 parts, the strength and physical properties of the silver surface layer deteriorate. The penetration of the adhesive layer into the base layer is preferably from the surface of the base layer to the inside of 30 to 200 μm below. If it is less than 30 μm, sufficient peeling strength tends to be unachievable, and if it exceeds 200 μm, the upper layer tends to be hard and creases tend to be rough. The preferred thickness of the non-porous silver surface layer is 10 to 100 μm. If it is less than 10 μm, sufficient surface strength tends to be unachievable.
When it exceeds μm, the texture as artificial leather becomes hard and the creases tend to be rough. The preferred thickness of the porous silver surface layer is
It is 70 to 500 μm. If it is less than 70 μm, sufficient surface strength tends to be unachievable, and if it exceeds 500 μm, a rubber-like texture tends to be obtained.

The artificial leather thus obtained is used for shoes,
In addition to miscellaneous goods such as bags and accessory cases, it can be used for interior goods such as upholstery for sofas and for clothing. The flame-retardant silver-finished artificial leather of the present invention is particularly suitable for applications requiring flame retardancy such as upholstery for vehicle seats of automobiles, railway vehicles, airplanes, ships, etc., and applications requiring strength. .

[0029]

EXAMPLES The present invention will now be specifically described with reference to Examples.
The present invention is not limited to these examples. Parts and% in the examples relate to weight unless otherwise specified. The thickness of the fiber referred to in the present invention was determined by the following method. The flame retardancy and surface abrasion strength in the examples were measured according to the following standards and methods. [Thickness of fiber]: Obtained by actually measuring the weight of the fiber bundle. [Fiber diameter in artificial leather sheet]: Obtained by observing the cross section of the sheet with an electron microscope (4000 times). [Phosphorus atom concentration]: After wet-decomposing the fiber component with an acid, ICP emission spectrometer IRI manufactured by Jarrell Ash Co., Ltd.
It was measured by SAP. [Flame retardancy test method]: Automotive interior material test method FMV
It was measured by SS-302. [Surface strength measurement method]: Taber wear (wear wheel: CS-
It was judged by the appearance of 10,000 kg after 10,000 times). [Feeling determination method]: Five panelists randomly selected from those engaged in the artificial leather manufacturing industry judged that the texture was good or bad, and judged by a majority vote.

Example 1 Using a known polyester polymerization method, using terephthalic acid as a main acid component and ethylene glycol as a main glycol component, a phosphorus-based flame retardant M-Ester (manufactured by Sanko Co., Ltd., molecular weight 434, phosphorus content) 7 wt%) was added during the polymerization to obtain a phosphorus-based flame retardant copolyester having a phosphorus atom concentration of 10,000 ppm. Sea-island type composite spun fiber (sea component / island component = 35/65, number of islands 16) using the phosphorus-based flame retardant copolyester as an island component and high-fluidity low-density polyethylene as a sea component is obtained by melt spinning. Then, this was stretched 2.5 times in warm water at 70 ° C., a fiber oil was applied, and after mechanical crimping and drying, it was cut to 51 mm to form 5.0 decitex staples, and the cross lap method was used. A web having a basis weight of 450 g / m ² was formed, and then alternately lapped from both sides to about 2000 P / cm ² needle punch, further heated and pressed with a calendar roll to form a entangled nonwoven fabric having a smooth surface. The unit weight of this entangled nonwoven fabric is 830 g / m ² , and the apparent density is 0.48 g / m ² .
It was cm ³ .

This entangled non-woven fabric is made of polycarbonate-based polyurethane and has a solid content of 14%, and is dimethylformamide of polyurethane (hereinafter sometimes abbreviated as DMF).
Impregnation with an impregnating solution (polyurethane / aluminum hydroxide = 100: 50) prepared by adding 17.5 parts of a 40% dispersion of aluminum hydroxide having an average particle size of 1 μm in DMF to 100 parts of the solution. Then, the impregnated nonwoven fabric is dipped in a DMF / water mixed solution and wet-coagulated, and then sea components in the sea-island type composite fiber are eluted and removed in hot toluene to express ultrafine fibers, and FMVSS- An artificial leather substrate having a thickness of 0.90 mm, which was determined to be flame retardant from the measurement result of 302, was obtained. The average fineness of the ultrafine fibers was 0.2 decitex. The weight ratio of the fibers in the artificial leather substrate to the polyurethane containing aluminum hydroxide was about 7: 2. Moreover, when the fiber cross section of the obtained artificial leather substrate was observed with a microscope, it was confirmed that many aluminum hydroxide particles were present inside the porous polymer elastic body.

On the release paper, 30 g / m ² as a solid content of a solution containing a polycarbonate-based polyurethane having a modulus of 100% elongation of 80 kg / cm ² as a main component was applied to form a skin layer, and a skin layer was formed on top of this. Ammonium polyphosphate as a flame retardant (Pekoflam manufactured by Clariant Co., Ltd.
TC203PDR) is added to 100 parts of the adhesive resin solid content in an amount of 15 parts, and a solution containing polycarbonate-based polyurethane as a main component is applied in a solid content of 100 g / m ² to form an adhesive layer, and an adhesive force is obtained. This was attached to one surface of the artificial leather substrate, aged at 60 ° C. for 48 hours, and then the release paper was peeled off to obtain a silver-tone artificial leather.
The obtained artificial leather with a silver tone was judged to be flame-retardant from the measurement results of FMVSS-302, and peeling of the skin did not occur even after the Taber abrasion measurement. Further, it had a soft texture similar to that of natural leather.

When a seat for a car seat was actually manufactured using the obtained flame-retardant silver-tone artificial leather, no processing problems due to strength or the like occurred, and a feeling similar to that when using natural leather was obtained. It became a seat that has both the external appearance and the flame retardancy required for car seats.

Comparative Example 1 A silver-tone artificial leather was produced under the same conditions as in Example 1 except that ordinary polyester was used as the island component. The obtained artificial leather was good in texture and surface abrasion strength, but judged to be flammable from the measurement results of FMVSS-302, and did not meet the object of the present invention.

Comparative Example 2 Except that aluminum hydroxide was not added to the polymeric elastic body,
Under the same conditions as in Example 1, a silver-tone artificial leather was produced.
The obtained artificial leather was good in texture and surface abrasion strength, but judged to be flammable from the measurement results of FMVSS-302, and did not meet the object of the present invention.

Comparative Example 3 An artificial leather with a silver tone was produced under the same conditions as in Example 1 except that magnesium hydroxide was used instead of aluminum hydroxide as the flame retardant added to the polymer elastic body. The obtained artificial leather was good in texture and surface abrasion strength, but judged to be flammable from the measurement results of FMVSS-302, and did not meet the object of the present invention.

Comparative Example 4 An artificial leather with a silver tone was produced under the same conditions as in Example 1 except that the sea-island fiber prepared by kneading a low molecular weight phosphorus flame retardant into the island component was used. Most of the kneaded flame retardant was removed in the ultrafine fiber generation step, and the obtained artificial leather had good texture and surface wear strength, but it was determined to be flammable from the measurement results of FMVSS-302. , Did not meet the purpose of the present invention.

Comparative Example 5 A silver-tone artificial leather was produced under the same conditions as in Example 1, except that the flame retardant was not added to the adhesive at the time of forming the silver surface layer. The obtained artificial leather was good in texture and surface abrasion strength, but judged to be flammable from the measurement results of FMVSS-302, and did not meet the object of the present invention.

Comparative Example 6 In Example 1, a phosphoric acid ester type flame retardant (addition of 50 parts to 100 parts of adhesive resin solid content) was used as a flame retardant added to the adhesive at the time of forming the silver surface layer. Produced an artificial leather with a silver tone under the same conditions. The obtained silver-tone artificial leather was judged to be flame-retardant from the measurement results of FMVSS-302, and peeling of the skin did not occur even after the Taber abrasion measurement, but the appearance change due to bleeding was remarkable and it was not practical. It was

Comparative Example 7 In Example 1, aluminum hydroxide (adhesive resin solid content 10%) was used as a flame retardant added to the adhesive when the silver surface layer was formed.
A silver-tone artificial leather was produced under the same conditions except that 70 parts was added to 0 part). The obtained silver-tone artificial leather was judged to be flame retardant from the measurement results of FMVSS-302, but peeling of the skin occurred after the Taber abrasion measurement,
It wasn't practical.

[0041]

EFFECT OF THE INVENTION The flame-retardant silver-tone artificial leather of the present invention is halogen-free and excellent in flame retardancy, and also extremely excellent in flame retardancy durability. The artificial leather with flame-retardant silver of the present invention is
It has a leather-like soft texture and is suitable for applications requiring flame retardancy such as automobile seats, railway car seats, aircraft seats, and sofa upholstery. Furthermore, the flame-retardant silver-coated artificial leather of the present invention can be used for general purposes other than artificial leather, such as wallpaper and carpets.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4F055 AA02 BA13 CA11 DA08 EA04                       EA09 EA12 EA24 EA34 FA20                       FA40 GA02 GA11 GA31                 4F072 AA08 AB05 AB29 AD02 AD43                       AE07 AF03 AF19 AG02 AH02                       AL02 AL09

Claims (5)

[Claims] 1. An ultrafine fiber (A) having 0.5 decitex or less.
In a silver-tone artificial leather in which a silver surface layer (C) is provided on at least one surface of an artificial leather substrate made of a non-woven fabric three-dimensionally entangled with each other and a polymeric elastic body (B) filled therein. The ultrafine fibers (A) are composed of a copolyester of an organic phosphorus component, the elastic polymer (B) contains aluminum hydroxide, and the silver surface layer (C) further contains polyphosphate. A flame-retardant silver-tone artificial leather characterized by the following. 2. The phosphorus atom concentration in the organic phosphorus component copolymerized polyester is 3000 ppm or more, and the content of aluminum hydroxide in the elastic polymer is 10 per 100 parts by weight of the elastic polymer (B). The flame-retardant silver-tone artificial leather according to claim 1, which is ˜200 parts by weight. 3. The flame-retardant, silver-tone artificial leather according to claim 1, which contains 3 to 50 parts by weight of polyphosphate with respect to 100 parts by weight of the constituent resin of the silver surface layer (C). 4. A vehicle seat in which the flame-retardant silver-toned artificial leather according to any one of claims 1 to 3 is used as an upholstery material. 5. An ultrafine fiber (A) having 0.5 decitex or less.
A non-woven fabric three-dimensionally entangled with each other and a polymer layer (B) filled inside the base layer to which a silver surface layer (C) added with polyphosphate is applied to provide a flame-retardant silver coating. In the production of a toned artificial leather, the following steps, the step of producing a fiber-entangled non-woven fabric composed of sea-island type multi-component fibers having an organic phosphorus component-containing polyester as an island component, and containing aluminum hydroxide inside the non-woven fabric. Filling the polymer elastic body (B), converting the fibers into a bundle of ultrafine fibers (A) having a single fineness of 0.5 decitex or less by a method such as removing sea components in the fibers, A method for producing a flame-retardant silver-tone artificial leather, characterized in that the step of applying a resin having a polyphosphate added to at least one surface of the base layer to form a silver surface layer is performed in the order of or.