JP6118174B2 - Non-woven fabric for artificial leather and artificial leather - Google Patents

Description

  The present invention relates to a nonwoven fabric for artificial leather having good quality and flame retardancy, and an artificial leather using this nonwoven fabric.

Artificial leather is suitably used in the fields of clothing, shoes, bags, interiors, furniture, seat skin materials and interior materials such as automobiles, railway vehicles, aircrafts and ships, and patch base materials. In these fields, in addition to good appearance quality and texture, flame resistance and resistance to physical loads such as wear are required.
The material for artificial leather is mainly in a form in which a nonwoven fabric structure is impregnated with a polymer elastic resin and adhered. Simply impregnating the fibers with a needle punch or water jet treatment without impregnating the elastic resin does not provide sufficient strength to withstand the load caused by the liquid flow during dyeing, or it is easy to use as artificial leather This causes the disadvantage of causing damage.

  Among artificial leather manufacturers, a technique of imparting a good texture and abrasion resistance by attaching a polymer elastic body such as polyurethane is generally used. For example, as artificial leather impregnated with polyurethane, it is commercially available under the names such as EXSEINE (trademark) and Alcantara (trademark). However, since a polymer elastic body such as polyurethane is easily combusted, it causes a problem that the flame retardancy of the artificial leather itself is lowered by the adhesion.

  Patent Document 1 discloses an example in which flame retardance is compensated by back coating a flame retardant with a type of artificial leather impregnated with polyurethane. While this method can provide good flame retardancy, the nonwoven fabric becomes extremely hard and has a drawback that a good texture cannot be obtained when used as artificial leather. In addition, since the flame retardant coating process is performed, the manufacturing process becomes complicated and the cost is likely to increase.

  In addition to impregnating and adhering polymer elastic bodies such as polyurethane, as a means of obtaining a binder effect to impart strength to artificial leather, heat-fusible fibers are mixed during the production of nonwoven fabric for artificial leather and melted In the past, methods for bonding the main fibers by doing so have been studied. For example, Patent Document 2 uses a fiber having a thick fiber diameter and a sheath-core type as the heat fusion fiber in the embodiment. Since the fusion points of the main fibers are connected via the fibers in the core, the nonwoven fabric has a hard texture and has a disadvantage of poor quality. Moreover, in patent document 3, since the process which heat-shrinks a nonwoven fabric is included, the molten lump of a heat-fusion fiber will become large, and it will be easy to produce the fault that it is inferior to surface quality. Furthermore, since molten fibers are generated from ultrafine fiber generating composite fibers typified by sea-island fibers, the molten mass tends to concentrate on the original composite fiber portions. Also from this point, the defect derived from the manufacturing method that the molten mass tends to be large is likely to occur.

  In patent document 4, the leather-like thing comprised by the laminated structure containing the fused fiber nonwoven fabric is proposed. In this document, the laminated structure is made such that the skin layer is made of ultrafine fibers, and the nonwoven fabric layer containing the fusion fibers is arranged in the lower layer. The laminated sheet obtained in this way has the disadvantage that it does not have wear resistance that can withstand practical use as artificial leather because the fibers on the outermost surface of the skin layer are not retained by fusion or the like.

Japanese Patent Publication No. 03-080914 JP 07-216756 A Japanese Patent Publication No. 03-016427 Japanese Patent No. 4835181

  An object of the present invention is to provide a nonwoven fabric for artificial leather having good texture, high wear resistance, and flame retardancy, and an artificial leather using the nonwoven fabric.

As a result of intensive studies to solve the above-mentioned problems, the inventor of the present invention, in the nonwoven fabric having a multilayer structure of two or more layers, the main fibers constituting the surface fiber layer are bonded by a block-shaped thermoplastic resin. The present inventors have found that a nonwoven fabric for artificial leather having good texture, high wear resistance, and flame retardancy can be obtained, and the present invention has been completed.
That is, the present invention provides the following inventions.

[1] Non-woven fabric for artificial leather having a multilayer structure of at least two layers of a surface fiber layer and a scrim layer as a fiber structure, and satisfying the following conditions (1) to (5):
(1) The surface fiber layer is composed of at least one kind of main fiber and a thermoplastic resin having a melting point lower by 20 ° C. or more than the melting point of the main fiber,
(2) At least a part of the thermoplastic resin is exposed on the surface of the surface fiber layer in a lump shape,
(3) At least a part of the thermoplastic resin is bonded between the main fibers,
(4) When the thermoplastic resin is observed from the surface, the average value of the projected area of the bulk resin is 1.3 × 10 ⁻⁹ m ² or less, and (5) the surface fiber layer and the scrim layer It is a structure in which the space is entangled and integrated.
[2] The nonwoven fabric for artificial leather according to [1], wherein the main fiber is a polyester fiber or a polyamide fiber.
[3] The nonwoven fabric for artificial leather according to [1] or [2], wherein the thermoplastic resin is a polyester resin or a polyamide resin.
[4] The surface fiber layer according to any one of the above [1] to [3], wherein the weight mixing ratio of the thermoplastic resin to the total of the thermoplastic resin and the main fiber is in the range of 5 to 25%. Non-woven fabric for artificial leather.
[5] The nonwoven fabric for artificial leather according to any one of the above [1] to [4], which has a flame retardancy of 4 or higher in the FMVSS flammability test.
[6] The nonwoven fabric for artificial leather according to any one of the above [1] to [5], which has a three-layer structure of surface fiber layer / scrim layer / back surface fiber layer.
[7] Obtained by raising the surface of the surface fiber layer of the nonwoven fabric for artificial leather according to any one of [1] to [6] in either of the following steps (1) or (2): Suede or nubuck-like artificial leather
(1) Raising the thermoplastic resin before heat fusion treatment,
(2) The thermoplastic resin is subjected to a fusing treatment after being heat-sealed.
[8] A silver-tone artificial leather having a coating layer on the surface of the nonwoven fabric for artificial leather according to any one of [1] to [6].

  In the present invention, since the main fibers constituting the surface fiber layer are bonded with a thermoplastic resin, a nonwoven fabric for artificial leather having both high quality and wear resistance can be obtained.

It is the figure which showed an example of the presence state of the block resin of a surface fiber layer. It is the figure which showed another example of the presence state of the block resin of a surface fiber layer. It is the figure which showed another example of the presence state of the block resin of a surface fiber layer. It is the figure which showed another example of the presence state of the block resin of a surface fiber layer. It is the figure which showed another example of the presence state of the block resin of a surface fiber layer. It is the figure which showed another example of the presence state of the block resin of a surface fiber layer. It is the figure which showed another example of the presence state of the block resin of a surface fiber layer. It is the figure which showed another example of the presence state of the block resin of a surface fiber layer.

Hereinafter, the present invention will be described in detail.
The nonwoven fabric for artificial leather and the artificial leather of the present invention have a multilayer structure of at least two layers of a surface fiber layer and a scrim layer. The surface fiber layer is composed of at least one or more types of main fibers and a thermoplastic resin having a melting point that is 20 ° C. lower than the melting point of the main fibers. The main fiber constituting the surface fiber layer is preferably a polyester fiber, a polyamide fiber, an acrylic fiber, or a polyolefin fiber from the viewpoints of strength, availability, and the like.

  As the polyester fiber, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactate or a copolymer thereof is preferably used. As the polyamide fiber, nylon, meta-aramid, para-aramid, or a copolymer thereof is preferably used. As the acrylic fiber, an acrylic ester or methacrylic ester polymer or a copolymer thereof is preferably used. As the polyolefin fiber, polyethylene, polypropylene, polybutene, polystyrene, or a copolymer thereof is preferably used.

The main fiber preferably has a fineness of 0.6 dtex or less, and a fineness of 0.35 dtex or less from the viewpoint that a texture close to natural leather or a suede-like or nubuck-like surface feeling can be easily obtained. Preferably, the fineness is more preferably 0.2 dtex or less. Further, from the viewpoint of production efficiency and production stability during fiber production, the fineness is preferably 0.001 dtex or more, more preferably 0.003 dtex or more.
Main fiber is obtained by removing sea component from fiber spun directly by melt spinning method, fiber obtained by wet spinning method, sea island fiber using copolymer polyester as sea component and regular polyester as island component. Extra fine fibers can be used.

Further, the main fiber may not necessarily be composed of only a single polymer fiber, and may be a mixture of other polymer fibers. Further, the main fiber may not necessarily be composed of only fibers having a single fineness, and fibers having a plurality of finenesses may be mixed.
In addition, additives may be mixed or adhered to the main fiber as long as the object of the present invention is not impaired. Additives refer to titanium oxide, various oxidation-resistant agents, light-proofing agents, antistatic agents, flame retardants, softeners, fastness improvers, pigments such as carbon black, and dyes.

  The thermoplastic resin having a melting point lower than the melting point of the main fiber constituting the surface fiber layer is 20% or more from the viewpoint of availability, polyester resin, polyamide resin, acrylic resin or polyolefin resin. preferable. As the polyester resin, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactate or a copolymer thereof is preferably used. As the polyamide resin, nylon or a copolymer thereof is preferably used. As the acrylic resin, polymers of acrylic acid esters or methacrylic acid esters or copolymers thereof are preferably used. As the polyolefin resin, polyethylene, polypropylene, polybutene, polystyrene or copolymers thereof are preferably used.

This thermoplastic resin does not necessarily have to be composed of only a single polymer, and a plurality of types of polymers may be mixed.
Further, additives such as additives may be mixed in or adhered to the thermoplastic resin as long as the object of the present invention is not impaired. Additives refer to titanium oxide, various oxidation-resistant agents, light-proofing agents, antistatic agents, flame retardants, softeners, fastness improvers, pigments such as carbon black, and dyes.
This thermoplastic resin has a melting point that is 20 ° C. or more lower than the melting point of the main fiber. When two or more main fibers are used, the thermoplastic resin has a melting point that is 20 ° C. or more lower than the melting point of the main fiber having the lowest melting point. It is necessary to have.

This thermoplastic resin is preferably exposed in the form of a lump on the surface of the surface fiber layer. If it is not exposed on the surface, the main fibers present on the surface are not sufficiently retained by resin fusion, and the fibers are likely to fall off or break down. Absent.
Moreover, it is preferable that part or all of this thermoplastic resin adhere | attaches between main fibers. If the thermoplastic resin is not bonded between the main fibers, the main fibers are not sufficiently retained, and the fibers are liable to fall off or break, so they do not have satisfactory wear resistance and strength as artificial leather. .

The average projected area of the block-shaped thermoplastic resin when the surface fiber layer is observed from the surface is preferably 1.3 × 10 ⁻⁹ m ² or less. When the average value of the projected area is larger than 1.3 × 10 ⁻⁹ m ^{2, the} resin mass present on the surface with respect to the main fiber is large, so that there is a drawback that the appearance quality and the hand feeling are impaired. . In addition, the density of the number of fusion points between the main fibers is reduced, and there is a disadvantage that the surface layer is inferior in wear resistance due to insufficient retention between the main fibers. More preferably, it is 1.1 × 10 ⁻⁹ m ² or less. On the other hand, the average value of the projected area is preferably 0.001 × 10 ⁻⁹ m ² or more from the viewpoint that it is desirable that the bulk resin is sufficiently large to bond the main fibers. More preferably, it is 0.01 × 10 ⁻⁹ m ² or more.

  The mixing ratio in the surface fiber layer of the thermoplastic resin in the present invention is preferably in the range of 5 to 25%. The mixing ratio is a value representing the weight of the thermoplastic resin as a percentage with respect to the total weight of the main fiber and the thermoplastic resin. When the mixing ratio is less than 5%, sufficient fusing power cannot be obtained, so it is difficult to obtain good wear resistance and form stability. On the other hand, when the mixing ratio exceeds 25%, the texture becomes hard, which is preferable. Absent. This mixing ratio is more preferably in the range of 7 to 20%.

  For the nonwoven fabric for artificial leather and the scrim layer constituting the artificial leather of the present invention, a fiber structure made of woven or knitted fabric or nonwoven fabric can be used. In the case of a knitted fabric, a single knit knitted with 22 to 28 gauge is preferable. In the case of a woven fabric, a non-twisted yarn of processed yarn or a twisted yarn of 400 to 1200 T / m is preferably used. In the case of a nonwoven fabric, spunbond, needle punch felt, spunlace and the like are preferable. The material of the scrim layer is preferably the same polymer as the main fiber from the viewpoint of the same color in dyeing.

The nonwoven fabric for artificial leather and the artificial leather of the present invention preferably have a multilayer structure of at least two layers of a surface fiber layer and a scrim layer. For example, it is possible to adopt a configuration composed of two layers of a surface fiber layer / scrim layer and a configuration composed of three layers of a surface fiber layer / scrim layer / back surface fiber layer.
In addition, the material constituting the back surface fiber layer in the case of adopting the structure of the surface fiber layer / scrim layer / back surface fiber layer as one aspect of the present invention is not particularly limited, but the main fiber and / or thermoplasticity of the above surface fiber layer It may be the same as the resin.

The nonwoven fabric for artificial leather and the artificial leather of the present invention preferably have a texture value of less than 26 cm as a substitute property of the texture, measured by the method described later, as a good texture when used as an artificial leather. More preferably, the value is less than 24 cm. If the texture value is large, it becomes too hard to use as artificial leather, and it becomes difficult to obtain good quality.
The non-woven fabric for artificial leather and artificial leather of the present invention has a value obtained by dividing the number of wear until the scrim is exposed by a test by the Martindale method as a good wear resistance when used as an artificial leather by a surface layer weight of 363. Times / (g / m ² ) or more, preferably 272 times / (g / m ² ) or more. If this value is small, it will not have sufficient wear resistance when used as artificial leather.
The nonwoven fabric for artificial leather and the artificial leather of the present invention preferably exhibit a flame retardance of 4th grade or higher, more preferably 5th grade flame retardancy, in the FMVSS test. It is easy to burn if it is flame retardant of 3rd grade or less, and the use suitable for using as artificial leather is limited.

As the method for producing a nonwoven fabric for artificial leather and artificial leather according to the present invention, at least one main fiber and all-melting type heat-fusible fiber having a melting point 20 ° C. lower than the melting point of the main fiber are mixed. A method in which the heat-fusible fiber is melted by heat-treating the non-woven structure having the surface fiber layer formed thereon to form a massive thermoplastic resin in the surface fiber layer is preferable.
This heat-fusible fiber is preferably a fully fusible fiber so that the molten resin has a sufficient number of points for fusing the main fibers. When the sheath-core type fiber using a low-melting point thermoplastic resin for the sheath part or the side-by-side type fiber using the low-melting point thermoplastic resin only on one side is used as the heat-fusible fiber, the main fiber The point of bonding is limited only to the point where it is in contact with the thermoplastic resin, and since the amount of the fusion component in the fusion part is small, there is a disadvantage that the fusion force is not sufficient. In addition, since the fusion point is continuously present in the vicinity through the heat-fusible fiber, there is a disadvantage that the texture is liable to become hard.

  The heat-fusible fiber having a melting point lower by 20 ° C. or more than the melting point of the main fiber constituting the surface fiber layer is polyester fiber, polyamide fiber, acrylic fiber or polyolefin fiber from the viewpoint of availability. Is preferred. As the polyester fiber, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactate or a copolymer thereof is preferably used. As the polyamide fiber, nylon or a copolymer thereof is preferably used. As acrylic fibers, polymers of acrylic esters or methacrylic esters or copolymers thereof are preferably used. As the polyolefin fiber, polyethylene, polypropylene, polybutene, polystyrene, or a copolymer thereof is preferably used.

This heat-fusible fiber does not necessarily have to be composed of only a single polymer, and a plurality of types of polymers may be mixed. From the viewpoint of high fusing power and identity in dyeing, the polymer system is preferably the same as the main fiber.
The heat-fusible fiber is a fiber that is directly spun by the melt spinning method, a fiber obtained by the wet spinning method, and removes the sea component from the sea island fiber using the copolyester as the sea component and the regular polyester as the island component. Can be used.
The fineness of the heat-fusible fiber is preferably 1.5 dtex or less from the viewpoint of the size of the bulk thermoplastic resin after melting. When the fineness is larger than 1.5 dtex, the average value of the projected area of the molten thermoplastic resin after melting becomes larger than 1.3 × 10 ⁻⁹ m ^2. It tends to have the disadvantage of impairing wear.

The heat-fusible fiber may be mixed or adhering with additives as long as the object of the present invention is not impaired. Additives refer to titanium oxide, various oxidation-resistant agents, light-proofing agents, antistatic agents, flame retardants, softeners, fastness improvers, pigments such as carbon black, and dyes.
This heat-fusible fiber has a melting point lower by 20 ° C. or more than the melting point of the main fiber, and when two or more main fibers are used, the melting point is 20 ° C. or lower than the melting point of the main fiber having the lowest melting point. It is necessary to have

As a method of forming the surface fiber layer, a method of directly forming a nonwoven fabric structure by a spunbond method, a melt blow method, etc., a main fiber and / or a heat-fusible fiber are used in the form of short fibers, a paper making method, a card method Or the method of forming a nonwoven fabric structure using the air array method etc. is mentioned.
From the viewpoint of uniform dispersibility of constituent fibers and easy utilization of ultrafine fibers, it is particularly preferable that the surface fiber layer is formed by a papermaking method. In the card method, fibers having a fineness of 0.6 dtex or less are easily wound around the needles of the carding roller and it is difficult to open the fibers. Even with the air array method, it is difficult to disperse fibers having a fineness of 0.6 dtex or less.

In addition, the hydroentanglement method called the spunlace method and the needle punch method can be used for entanglement integration between the layers in the present invention, but the hydroentanglement method does not destroy the structure of the woven or knitted fabric that is the scrim layer. Is preferred.
In the heat fusion treatment in the present invention, a drum dryer, a contact dryer such as a calender roll, or an air-through dryer such as a pin tenter dryer can be used. The treatment temperature is a temperature that is 5 ° C. or more, preferably 10 ° C. or more higher than the melting point of the thermoplastic resin that constitutes the surface fiber layer and that has a melting point that is 20 ° C. lower than the melting point of the main fiber. If the difference between the treatment temperature and the melting point of the thermoplastic resin is less than 5 ° C., a sufficient heat-sealing effect may not be obtained.

The nonwoven fabric for artificial leather obtained by the above method is used as artificial leather of suede or nubuck by raising the surface of the surface fiber layer and dyeing it. As the raising treatment, a known method such as buffing with sandpaper can be used. In this case, a suede-like surface feeling can be obtained by raising the hair before the heat-fusible fibers of the surface fiber layer are heat-sealed. On the other hand, a nubuck-like surface feeling can be obtained by raising the heat-fusible fibers after heat-sealing them.
When finishing to artificial leather with silver, heat-seal the heat-sealable fiber of the nonwoven fabric for artificial leather, dye it if necessary, and then polymer elasticity such as wet polyurethane or dry polyurethane on the surface An artificial leather with silver can be produced by forming a coating layer by a known method such as coating a body or pasting a silver surface layer formed on a release paper on a nonwoven fabric for artificial leather.

  In the dyeing treatment, for example, when the main fiber is a polyester fiber, a disperse dye is generally used, and when the main fiber is a polyamide fiber, an acid dye is generally used. The dyeing method can be a conventional method well known to dyeing processors, and a liquid dyeing machine is preferably used for artificial leather from the viewpoint of levelness. The artificial leather thus dyed is reduced and washed in the presence of soaping or a chemical reducing agent to remove excess dye.

EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited only to these Examples. In addition, the physical-property value shown by this invention and the physical-property value in an Example are measured with the following method.
(1) Average value of projected area of bulk resin 100 images were sampled by photographing 100 arbitrary positions on the surface of the sample nonwoven fabric at a magnification of 250 times of a scanning electron microscope. Using each image, the area of 100 points of the block resin was obtained and averaged to obtain the average value of the projected area of the block resin.

For the photographing, a scanning electron microscope JSM-5610 manufactured by JEOL Ltd. was used. ImageJ was used as image processing software for calculating the area of the block resin. It calculated | required by converting the area obtained by fringing the block resin from the image of 250 times magnification into the reduced scale of a picked-up image. The area obtained by edging was rounded off to the nearest 0.001 × 10 ⁻⁹ m ² . The average value of the area of 100 block resins was rounded to the nearest less than 0.1 × 10 ⁻⁹ m ² .
For the selection of the bulk resin, a criterion for counting those satisfying that the bulk resin adhered between the main fibers and that the bulk resin was exposed on the surface of the surface fiber layer was used. The phrase “the block resin is bonded between the main fibers” means that the block resin is in contact with and integrated with two or more main fibers. The phrase “the block resin is exposed on the surface of the surface fiber layer” means that the entire surface of the block resin is exposed on the surface without being hidden by the main fibers. 1-8 is the schematic diagram which showed the presence state of the block resin of the surface fiber layer. The state of the bulk resin and its determination will be described using these figures. FIG. 1 is an example in which the main fiber is not adhered to the surface of the surface fiber layer, and FIG. 2 is exposed on the surface. This is an example in which the main fibers are bonded. 3 is an example in which the main fibers are bonded to each other, although not exposed on the surface, FIG. 4 is an example in which the main fibers are bonded to the surface, and FIG. This is an example in which the main fibers are not bonded. FIG. 6 is an example in which the resin (heat-fusible fiber) is not melted, and is not called a bulk resin. FIG. 7 shows an example in which a sheath core fiber is used as the heat-fusible fiber. The heat-fusible fiber remains in a fiber shape and is not called a bulk resin. FIG. 8 shows an example in which the main fibers are not bonded, although they are exposed on the surface. In the figure, 1 is a main fiber, 2 is a block resin, 3 is an unmelted resin, and 4 is a sheath core fiber.

(2) Fineness Ten arbitrary positions of the sample were photographed at a magnification of 2500 times of a microscope, the diameters of 50 fibers were measured, and the average value thereof was obtained as the average fiber diameter. In terms of the average fiber diameter, the fineness [dtex] was determined.
(3) Texture A sample is cut into a 20 cm × 20 cm square to obtain a measurement sample. A measurement sample is placed on a horizontal plane, and apexes of a square are set as A, B, C, and D, and apexes A and C facing each other diagonally or one apex of B and D are superimposed on the other apex. For example, the vertex A is placed on the horizontal plane, and the vertex C is superimposed on the vertex A. Next, when the vertex C is in contact with the measurement sample, it is gradually moved away from the vertex A along the diagonal line AC. The texture value is a substitute characteristic of the texture. The smaller the texture value, the better the texture. The evaluation criteria are shown below. A texture value of less than 26 cm was regarded as acceptable (◯ or ◎).
X: A texture value is 28 cm or more.
Δ: The texture value is 26 cm or more and less than 28 cm.
○: The texture value is 24 cm or more and less than 26 cm.
A: The texture value is less than 24 cm.

(4) Abrasion resistance The sample surface was abraded at a pressure load of 12 kPa by the method defined in JIS-L-1096 E method (Martindale method). As an evaluation standard in this test method, the sample surface layer was worn and evaluated according to the following grade according to the number of wear until the scrim was exposed.
X: The scrim is exposed when the number of wear is less than 20000.
(Triangle | delta): A scrim is exposed by the frequency | count of abrasion 20000 times or more and less than 30000 times.
○: The scrim is exposed when the wear frequency is 30000 times or more and less than 40000 times.
A: The scrim is exposed when the wear frequency is 40000 times or more.

(5) Flame retardance Measurement was carried out based on the US Federal Motor Vehicle Safety Standard “FMVSS No. 302”. In this measurement, the grade was determined according to the following criteria.
Grade 5: The burning part does not reach the burning speed range.
Fourth grade: Combustion length is less than 50 mm and combustion time is within 60 seconds.
Third grade: Sample was burned at an average burning rate of less than 50 mm / min.
Second grade: Sample burned out at an average burning rate of 50 mm / min or more and less than 100 mm / min.
First grade: Sample burned out at an average burning rate of 100 mm / min or more.

[Production Example 1-1]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. As the thermoplastic fiber, a single-fiber fineness 0.7 dtex made of a polyethylene terephthalate copolymer having a melting point of 180 ° C. and a total melt-type heat-fusible fiber (Casvene 8000 manufactured by Unitika Ltd.) having a length of 5 mm was used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 95: 5 to prepare a slurry. A paper sheet for surface fibers having a basis weight of 110 g / m ² was produced from this slurry by a paper making method.

[Production Example 1-2]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. As the thermoplastic fiber, a single-fiber fineness 0.7 dtex made of a polyethylene terephthalate copolymer having a melting point of 180 ° C. and a total melt-type heat-fusible fiber (Casvene 8000 manufactured by Unitika Ltd.) having a length of 5 mm was used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 90: 10 to prepare a slurry. A paper sheet for surface fibers having a basis weight of 110 g / m ² was produced from this slurry by a paper making method.

[Production Example 1-3]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. As the thermoplastic fiber, a single-fiber fineness 0.7 dtex made of a polyethylene terephthalate copolymer having a melting point of 180 ° C. and a total melt-type heat-fusible fiber (Casvene 8000 manufactured by Unitika Ltd.) having a length of 5 mm was used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 80: 20 to prepare a slurry. A paper sheet for surface fibers having a basis weight of 110 g / m ² was produced from this slurry by a paper making method.

[Production Example 1-4]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. As the thermoplastic fiber, a single-fiber fineness 1.1 dtex made of polyethylene terephthalate copolymer having a melting point of 180 ° C. and a length of 5 mm, a fully-melt type heat-fusible fiber (Cassben 8000 manufactured by Unitika Ltd.) was used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 90: 10 to prepare a slurry. A paper sheet for surface fibers having a basis weight of 110 g / m ² was produced from this slurry by a paper making method.

[Production Example 1-5]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. A single fiber fineness of 1.7 dtex and a length of 5 mm made of a polyethylene terephthalate copolymer having a melting point of 180 ° C. and a length of 5 mm as a thermoplastic fiber were used as a fully fusible fiber (Casvene 8000 manufactured by Unitika Ltd.). These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 90: 10 to prepare a slurry. A paper sheet for surface fibers having a basis weight of 110 g / m ² was produced from this slurry by a paper making method.

[Production Example 1-6]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. As the thermoplastic fiber, a single-fiber fineness 2.2 dtex made of polyethylene terephthalate copolymer having a melting point of 180 ° C. and a total melt-type heat-fusible fiber (Casvene 8000 manufactured by Unitika Ltd.) having a length of 5 mm was used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 90: 10 to prepare a slurry. A paper sheet for surface fibers having a basis weight of 110 g / m ² was produced from this slurry by a paper making method.

[Production Example 1-7]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. Thermoplastic fibers were not used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 100: 0 to prepare a slurry. A paper sheet for surface fibers having a basis weight of 110 g / m ² was produced from this slurry by a paper making method.

[Production Example 2-1]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. As the thermoplastic fiber, a single-fiber fineness 0.7 dtex made of a polyethylene terephthalate copolymer having a melting point of 180 ° C. and a total melt-type heat-fusible fiber (Casvene 8000 manufactured by Unitika Ltd.) having a length of 5 mm was used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 97: 3 to prepare a slurry. A papermaking sheet for backside fibers having a basis weight of 60 g / m ² was produced from this slurry by papermaking.

[Production Example 2-2]
A polyethylene terephthalate fiber having a single fiber fineness of 0.17 dtex and a melting point of 255 ° C. was produced by a direct spinning method and cut into a length of 5 mm to obtain a main fiber. Thermoplastic fibers were not used. These short fibers were dispersed in water so as to have a weight ratio of main fiber: thermoplastic fiber = 100: 0 to prepare a slurry. A papermaking sheet for backside fibers having a basis weight of 60 g / m ² was produced from this slurry by papermaking.

[Example 1]
The papermaking sheet described in Production Example 1-1 was used as the surface fiber layer, the papermaking sheet described in Production Example 2-1 was used as the back fiber layer, and laminated with the woven scrim, and the surface fiber layer / scrim layer / back fiber layer. The three-layer structure was used. The obtained three-layer laminate was entangled by jetting a high-speed water stream using a straight flow jet nozzle, and then entangled and integrated at 100 ° C. using an air-through type pin tenter dryer. A layered nonwoven fabric was obtained. Note that a woven fabric having a basis weight of 100 g / m ² made of polyethylene terephthalate fiber of 166 dtex / 48f was used for the scrim layer.
After buffing the surface of the surface fiber layer of the obtained nonwoven fabric by buffing with 400 mesh sandpaper, heat-sealing treatment of heat-fusible short fibers by heat treatment at 190 ° C. using a pin tenter dryer To obtain a nonwoven fabric for artificial leather. Subsequently, using a blue disperse dye (BlueFBL: manufactured by Sumitomo Chemical Co., Ltd.), it was dyed at 130 ° C. with a liquid dyeing machine to obtain a suede-like artificial leather. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Example 2]
In Example 1, a non-woven fabric for artificial leather and artificial leather having a suede tone were obtained in the same manner as in Example 1 except that the sheet described in Production Example 1-2 was used as the paper sheet for the surface fiber layer. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Example 3]
In Example 1, a nubuck-like non-woven fabric for artificial leather and artificial leather were obtained in the same manner as in Example 1 except that heat treatment was performed at 190 ° C. using a pin tenter dryer before raising treatment. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Example 4]
In Example 1, a non-woven fabric for artificial suede leather and artificial leather were obtained in the same manner as in Example 1 except that the sheet described in Production Example 1-3 was used as the paper sheet for the surface fiber layer. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Example 5]
In Example 1, a nonwoven fabric for artificial suede and artificial leather were obtained in the same manner as in Example 1 except that the sheet described in Production Example 1-4 was used as the paper sheet for the surface fiber layer. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Comparative Example 1]
In Example 1, a non-woven fabric for artificial suede and artificial leather were obtained in the same manner as in Example 1 except that the sheet described in Production Example 1-5 was used as the paper sheet for the surface fiber layer.

[Comparative Example 2]
In Example 1, a non-woven fabric for artificial suede and artificial leather were obtained in the same manner as in Example 1 except that the sheet described in Production Example 1-6 was used as the paper sheet for the surface fiber layer. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Comparative Example 3]
In Example 1, after carrying out the raising process, the nonwoven fabric for artificial leather and artificial leather of the suede tone were obtained like Example 1 except heat-processing at 180 degreeC using a pin tenter dryer. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Comparative Example 4]
In Example 1, except that a sheath core type fiber having a fineness of 2.2 dtex, in which a polyethylene terephthalate copolymer having a melting point of 180 ° C. is arranged in the sheath and a polyethylene terephthalate having a melting point of 255 ° C. in the core is used as the thermoplastic fiber. In the same manner as in Example 1, a non-woven fabric for artificial leather and artificial leather having a suede tone were obtained. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Comparative Example 5]
The papermaking sheet described in Production Example 1-7 is used as a surface fiber layer, and the papermaking sheet described in Production Example 2-2 is used as a back fiber layer, which is laminated with a woven scrim, and the surface fiber layer / scrim layer / back fiber layer. The three-layer structure was used. The obtained three-layer laminate was entangled by jetting a high-speed water stream using a straight flow jet nozzle, and then entangled and integrated at 100 ° C. using an air-through type pin tenter dryer. A layered nonwoven fabric was obtained. Note that a woven fabric having a basis weight of 100 g / m ² made of polyethylene terephthalate fiber of 166 dtex / 48f was used for the scrim layer.
After buffing the surface of the surface fiber layer of the obtained nonwoven fabric by buffing with 400 mesh sandpaper, a nonwoven fabric for artificial leather was obtained by impregnating with a polyether-based aqueous polyurethane emulsion. The polyurethane impregnation rate with respect to the base fabric before adhesion was 12 wt%. Subsequently, using a blue disperse dye (BlueFBL: manufactured by Sumitomo Chemical Co., Ltd.), it was dyed at 130 ° C. with a liquid dyeing machine to obtain a suede-like artificial leather. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

[Comparative Example 6]
In Comparative Example 5, a non-woven fabric for artificial leather and artificial leather having a suede tone were obtained in the same manner as in Comparative Example 5 except that the polyurethane impregnation ratio to the base fabric before adhesion was 7 wt%. The evaluation results of the obtained artificial leather are shown in Table 1 together with the production conditions.

  The nonwoven fabric or artificial leather for artificial leather of the present invention has good grade and flame retardancy, and is used for clothing, shoes, bags, interiors, furniture, seat skin materials and interior materials for automobiles, railway vehicles, aircraft, ships, etc. It is suitably used in the field of emblem base materials.

1 Main fiber 2 Bulk resin 3 Unmelted resin 4 Sheath core fiber

Claims (8)

Nonwoven fabric for artificial leather having a multilayer structure of at least two layers of a surface fiber layer and a scrim layer as a fiber structure, and satisfying the following conditions (1) to (5):
(1) The surface fiber layer is composed of at least one main fiber and a thermoplastic resin having a melting point that is 20 ° C. lower than the melting point of the main fiber,
(2) At least a part of the thermoplastic resin is exposed on the surface of the surface fiber layer in a lump shape,
(3) At least a part of the thermoplastic resin is bonded between the main fibers,
(4) When the thermoplastic resin is observed from the surface, the average value of the projected area of the bulk resin is 1.3 × 10 ⁻⁹ m ² or less, and (5) the surface fiber layer and the scrim layer It is a structure in which the space is entangled and integrated.   The nonwoven fabric for artificial leather according to claim 1, wherein the main fibers are polyester fibers or polyamide fibers.   The nonwoven fabric for artificial leather according to claim 1 or 2, wherein the thermoplastic resin is a polyester resin or a polyamide resin.   The nonwoven fabric for artificial leather according to any one of claims 1 to 3, wherein in the surface fiber layer, the weight mixing ratio of the thermoplastic resin to the total of the thermoplastic resin and the main fiber is in the range of 5 to 25%.   The nonwoven fabric for artificial leather according to any one of claims 1 to 4, which is flame retardant of grade 4 or higher in an FMVSS flammability test.   The nonwoven fabric for artificial leather according to any one of claims 1 to 5, which has a three-layer structure of surface fiber layer / scrim layer / back surface fiber layer. Suede tone or nubuck tone obtained by raising the surface of the surface fiber layer of the nonwoven fabric for artificial leather according to any one of claims 1 to 6 in the following step (1) or (2): Artificial leather:
(1) Raising the thermoplastic resin before heat fusion treatment,
(2) The thermoplastic resin is subjected to a fusing treatment after being heat-sealed.   The silver-tone artificial leather which has a coating layer on the surface of the nonwoven fabric for artificial leather as described in any one of Claims 1-6.

Images