JP3967486B2 - Artificial leather suitable for school bags - Google Patents

Description

【００４１】
【発明の効果】
以上のように、表面層が厚さ３０〜４００μｍのポリウレタン樹脂で、中間層は繊度０．１〜０．０００１デニールのナイロン極細繊維不織布に多孔質ポリウレタン樹脂を含浸凝固させた繊維質基材（Ａ）と、裏面層は繊度０．１〜０．０００１デニールのポリエステル極細繊維不織布に多孔質ポリウレタン樹脂を含浸凝固させた繊維質基材（Ｂ）より構成され、中間層と裏面層の厚み比率（Ａ）／（Ｂ）が０．５〜５となるように積層した人工皮革を用いることで、平滑で風合い良好な外観を有し、大きなクッション性を有するランドセル用素材を製造することが出来る。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an artificial leather having a good cushioning property, particularly an artificial leather suitable for a school bag.
[0002]
[Prior art]
Conventionally, the fabric for school bags has been used for base layers such as fibrous base materials and natural leather floor skins made by impregnating and solidifying a nylon fiber nonwoven fabric or polyester ultrafine fiber nonwoven fabric with polyurethane resin, and directly or wet-coating the resin on it. Or after laminating a non-porous polyurethane sheet, gravure coating, embossing finishing, dry surface finishing, and the like are performed.
[0003]
[Problems to be solved by the invention]
A product in which the base layer is composed only of a nylon fiber nonwoven fabric has poor recovery of creases during bending and poor dimensional stability. In addition, products composed only of polyester microfiber nonwoven fabric are paper-like and have a hard texture. Products using natural leather flooring are excellent, but they are hard and expensive.
Also, those using a wet coat layer have low bending durability and surface strength. A laminate of non-porous polyurethane sheets can greatly improve the recovery of creases, but has the disadvantage of increasing the weight of the product.
An object of the present invention is to provide an artificial leather that is extremely suitable for a school bag having good surface smoothness and creases, and good surface cushioning.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have laminated at least the following surface layer (1), the following intermediate layer (A) and the back surface layer (B), and the intermediate layer and the back surface It has been found that the above object can be achieved by an artificial leather characterized in that the layer thickness ratio (A) / (B) is 0.5 to 5.
(1) A resin layer having a thickness of 30 to 400 μm formed of a polyurethane resin,
(A) a fibrous layer obtained by impregnating and solidifying a porous polyurethane resin on a nylon ultrafine fiber nonwoven fabric having a fineness of 0.1 to 0.0001;
(B) a fibrous layer obtained by impregnating and solidifying a porous polyurethane resin on a polyester ultrafine fiber nonwoven fabric having a fineness of 0.1 to 0.0001 denier,
Furthermore, in this invention, it discovered that a more favorable cushioning property was acquired by the fiber base material using the nylon extra fine fiber nonwoven fabric used for an intermediate | middle layer (A) being relaxed and / or softened.
[0005]
The present invention will be described in detail below.
First, the ultrafine fibers constituting the layers (A) and (B) of the present invention are multicomponent fibers composed of at least two types of spinnable polymers having different chemical or physical properties, and preferably have a sea-island structure in cross section. The fiber obtained is spun, the resulting fiber is made into a non-woven fabric, and at least one kind of polymer, usually a sea component polymer, is extracted at an appropriate stage before or after the non-woven fabric is impregnated with an elastic resin. It is a fiber that has been removed to change its fiber form. The multicomponent fiber that generates this ultrafine fiber is an ultrafine fiber generation type fiber, and a typical example thereof is a sea-island type fiber as described above.
[0006]
Examples of the polymer constituting the island component of the ultrafine fiber-generating fiber include, for example, nylons such as nylon 6, nylon 66, nylon 610, and nylon 12, and other spinnable polyamides. And at least one polymer selected from the group consisting of: Polyester ultrafine fiber components include polyethylene terephthalate or its main copolymer, polybutylene terephthalate or its main copolymer, polyethylene naphthalate or its main copolymer, etc. And at least one polymer selected from these polyesters.
[0007]
The polymer that constitutes the sea component is a polymer that has a different solubility or decomposability to the island component polymer and the solvent or decomposing agent and has a low affinity with the island component polymer, and melts the island component under the spinning conditions. A polymer having a melt viscosity smaller than the viscosity or a low surface tension, such as polyethylene, polypropylene, polystyrene, ethylene propylene copolymer, ethylene vinyl acetate copolymer, styrene ethylene copolymer, styrene acrylic copolymer And at least one polymer selected from polymers such as
[0008]
The proportion of the ultrafine fiber component in the ultrafine fiber generating fiber is preferably 40 to 80% by weight from the viewpoint of spinning stability and economy. The ultrafine fiber-generating fiber is made into a fiber having a fineness of 2 to 10 denier by a conventionally known method through processing steps such as stretching, crimping, heat setting, cutting, and opening.
In the present invention, an ultrafine fiber-generating fiber that generates at least two types of ultrafine fibers having different polymers is used, but a single filament of nylon ultrafine fiber (a) constituting the surface on which the silver surface (surface layer) is provided The fineness needs to be 0.1 to 0.0001 denier, and the preferred fineness is 0.01 or less. If the fineness exceeds 0.1 denier, the surface irregularities become conspicuous when a silver surface is applied, and the smoothness peculiar to the school bag cannot be expressed. Further, if it is less than 0.0001 denier, the fiber strength is insufficient and the product strength is lowered, so that it is necessary to be 0.0001 denier or more.
[0009]
The polyester ultrafine fiber (b) can be adjusted according to the desired setting and texture, but if the fineness exceeds 0.1 denier, the fiber is too thick and the bent portion of the crown of the satchel is bent. In order to cause a sense of incongruity due to an increase in my size, it is necessary to make it 0.1 denier or less. Further, if it is less than 0.0001 denier, the fiber strength is insufficient and the product strength is lowered, so that it is necessary to be 0.0001 denier or more.
[0010]
Next, the ultrafine fiber-generating fibers (a) and (b) are each defibrated with a card, and a random web or a cross-wrap web (Wa) and (Wb) are formed through a webber, and a desired weight and thickness are formed. Say it. In the artificial leather of the present invention, the nylon ultrafine fiber base material and the polyester ultrafine fiber base material are laminated, but are laminated at the web stage or the fiber base stage after the resin impregnation extraction.
The ratio of (Wa) and (Wb) at the time of lamination can be arbitrarily selected according to the target quality of the final product, but a preferable range is 20/80 to 80/20 as a fiber weight ratio in the product. Within range. If it is out of this range, it will be too biased in one direction and it will be difficult to obtain a sense of tilt.
[0011]
Subsequently, the webs or webs laminated are entangled by needle punch. The number of needle punches varies depending on the shape of the needle used and the thickness of the web, but is generally 200 to 2500 punches / cm.²It is set within the range. If the needle punching condition is too strong, the fiber cutting rather than the fiber entanglement effect will increase, leading to a decrease in physical properties such as tearing strength. On the other hand, if the needle punching condition is too weak, it causes deterioration in physical properties such as peel strength and poor appearance and smoothness due to insufficient napped fibers.
[0012]
Next, the entangled nonwoven fabric is pressed in the thickness direction to improve the smoothness of the nonwoven fabric. As a pressing method, a method of passing between two heating rolls, a method of passing a preheated nonwoven fabric between cooling rolls, and the like can be used.
[0013]
Next, the entangled nonwoven fabric is impregnated with a polyurethane-based polymer elastic body. Examples of the polyurethane-based polymer elastic body include resins conventionally used for the production of leather-like sheets, such as a polyurethane-based resin alone, Or a mixture of natural rubber, synthetic rubber, polyether elastic body, polyvinyl chloride resin, polyvinyl butyral resin, polyacrylic acid resin, polyamino acid resin, silicon resin, etc. Of course, these resins may be copolymers. These are impregnated into the fiber as an aqueous emulsion or an organic solvent solution, and then solidified to form a substrate composed of the fiber and a polyurethane polymer elastic body. The reason why the polyurethane-based resin is used in the present invention is that the resulting product is natural leather-like and is excellent in physical properties such as durability.
[0014]
Examples of the polyurethane resin impregnated into the fiber include at least one selected from polyester diol, polyether diol, polyester ether diol, polycarbonate diol, etc. having an average molecular weight of 500 to 3000. Polymer polyols and aromatic, alicyclic and aliphatic groups such as 4,4'-diphenylmethane diisocyanate, isophorodiisocyanate and hexamethylene diisocyanate. At least one diisocyanate compound selected from diisocyanates and the like, and at least one low molecular weight compound having two or more active hydrogen atoms and having a molecular weight of 300 or less, such as ethylene glycol, propylene glycol, Butanediol, 3-methyl-1,5-pentanediol, N-methyldiethanolamine Diols such as ethylene diamine, isophorone diamine, piperazine, phenylene diamine and the like, and at least one selected from hydrazides such as adipic acid hydrazide and isophthalic acid dihydrazide were obtained by reacting at a predetermined molar ratio. A polyurethane is mentioned. If necessary, a compound having three or more active groups may be used in combination.
[0015]
These polyurethane elastic resins are used in the form of a solution or a dispersion or a mixture of a solution and a dispersion, and a coagulation regulator, a foaming agent, other treatment agents, a softening agent, a flame retardant, and the like may be added thereto. As a method of impregnating a fiber assembly with a polyurethane elastic resin, a polyurethane elastic resin liquid is impregnated into the fiber assembly by a dipping method, a coating method, an indentation method, etc., and then a wet method, a dry method, or both methods are used. A method of coagulating a polyurethane elastic resin into a porous or non-porous structure by using in combination. Among them, it is preferable to solidify the impregnated polyurethane elastic resin into a porous shape from the viewpoint of natural leather-like texture, touch, and the like.
[0016]
The fibrous base material impregnated and solidified with the polyurethane elastic resin is a non-solvent for ultrafine fibers and polyurethane elastic bodies, and the sea component polymer of the ultrafine fiber generating fiber is treated with a solvent or a liquid that is a decomposition agent. Thus, the sea component polymer is removed from the fiber, and the ultrafine fiber generating fiber is made into an ultrafine fiber bundle.
[0017]
The total thickness of the fibrous base materials (A) and (B) can be arbitrarily selected according to the target quality of the final product, and is not particularly limited, but the nylon ultrafine fiber nonwoven fabric and the polyester ultrafine fiber at the stage of the web Regardless of whether the non-woven fabrics are laminated and the polyurethane ultra-fine fiber non-woven fabric and the polyester ultra-fine fiber non-woven fabric are individually impregnated with the polyurethane elastic body, preferably 0.3 mm to 3 mm, particularly preferably 0.5 mm to 2.0 mm. It is.
Further, the quantitative ratio between the fibers constituting the fibrous base materials (A) and (B) and the polyurethane elastic body is preferably in the range of 80:20 to 40:60 by weight. If it is out of this range, the balance between the fiber and the polyurethane elastic body will be poor, and the product will be lost or a sense of fulfillment will not be obtained.
[0018]
When the nylon ultrafine fiber substrate (A) and the polyester ultrafine fiber substrate (B) are produced individually, they are bonded after becoming the fibrous substrate. The bonding method uses a conventionally known technique, for example, a method in which an adhesive is applied and bonded to the bonding surface, or a method in which a liquid that becomes a solvent is applied to the polyurethane elastic body impregnated in the bonding surface and the two substrates are bonded to each other. it can. In order to achieve a dense and strong bond, it is preferable to raise the bonding surface with a buff or the like prior to bonding.
Further, a superior cushioning property can be obtained by relaxing and / or softening the nylon ultrafine fibrous base material (A) by a known technique before bonding. Specific relaxation methods include, for example, methods such as Wins relaxation and circular relaxation, and examples of the flexible processing method include a method of applying a general softener and a method of carrying out mechanical scissors.
[0019]
In the present invention, the thickness ratio (A) / (B) between the nylon ultrafine fiber substrate (A) and the polyester ultrafine fiber substrate (B) needs to be 0.5-5. If it is less than 0.5, it is difficult to obtain the desired cushioning property. When the thickness ratio is greater than 5, the crease becomes deep and the uncomfortable feeling appears. The preferred range is 0.8 to 2, more preferably 1 to 1.5. In the present invention, the thickness of the nylon ultrafine fiber substrate (A) and the polyester ultrafine fiber substrate (B) is a dye that is dyed (A) but not (B) substantially (A) ) Is not substantially dyed, but (B) is dyed with the dye to be dyed, and then the laminate is subjected to a pressure load of 240 g / cm in accordance with JIS L1096.²In this state, the thickness ratio of (A) and (B) is obtained by observing the cross section in the thickness direction of the laminate and dividing it into a dyed portion and an undyed portion.
[0020]
As described above, an artificial leather base suitable for the school bag of the present invention is manufactured. The surface on which the film layer with silver (1) is laminated is the surface of the nylon ultrafine fibrous base material (A), and as the resin to be laminated, polyester polyurethane, polyether polyurethane, polyester ether polyurethane, Known resins such as polycarbonate-based polyurethanes, mixed systems thereof, and modified polyurethane resins such as silicon-modified polyurethane are used, and can be selected according to the target quality of the final product. Moreover, you may add additives, such as antioxidant, another colorant, a pigment, etc. in the range which does not impair the objective of this invention as needed. The 100% modulus of the laminated resin may be selected depending on the application, but it is 30 to 100 kg / cm from the viewpoint of texture and surface feeling.²The range of is preferable. Moreover, although the thickness of the resin layer (1) depends on the 100% modulus of the resin, the range of 30 μm to 400 μm is preferable in terms of obtaining a natural leather-like texture. If it exceeds 400 μm, the overall texture is felt hard and the cushioning property is lost, and if it is thinner than 30 μm, the surface physical properties deteriorate, which is not preferable. However, this is not the case when higher sensitivity is intended.
[0021]
The method of laminating the resin layer (1) is a coating method using knife coating, gravure coating, etc., a method in which a resin is applied to a release paper, adhered to a substrate, dried, and then released from the release paper. Conventionally known methods such as a method of applying and drying and then bonding the substrate with an adhesive and then peeling the release paper, a method of applying a molten resin on the substrate and cooling and solidifying the resin are used. Prior to lamination, it is possible to perform pretreatment such as buffing and relaxation treatment on the substrate in order to improve coloring and texture. In the present invention, in addition to the following surface layer (1), intermediate layer (A), and back layer (B), if necessary, a resin layer, a fiber layer, etc. may be laminated or sandwiched within a range not departing from the object of the present invention. May be inserted. The artificial leather of the present invention is extremely suitable as a material for a school bag, particularly a surface material for a cover part called a crown part of a school bag, and further, a lateral part (thickness part) called a heel part, a shoulder strap part It is also suitable for the front part (the front part of the school bag that appears when the crown is lifted).
[0022]
【Example】
EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In addition, unless otherwise indicated, the part and% in an Example are related to a weight.
The measurement of denier of ultrafine fibers was calculated by the following method.
Fiber denier = D x π (R / 2)²× 9 × 10^Five
Where R is the average diameter (cm) of the ultrafine fibers in the ultrafine fiber bundle (taken by scanning the substrate cross section with a scanning electron microscope, randomly selected 10 ultrafine fiber bundles, and ultrafine fibers in each ultrafine fiber bundle cross section 20 are selected from the cross section of the fiber bundle uniformly, and the diameter is measured to obtain an average value), and D is the specific gravity of the ultrafine fiber.
[0023]
Example 1
50 parts by weight of polyethylene as a sea component and 50 parts by weight of 6-nylon as an island component are melt-spun in the same melt system, and an ultrafine fiber generating fiber (a1) having an average number of islands of about 600 in the fiber cross section and a single fiber fineness of 10 denier. ) Was manufactured. The composite fiber is stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and weight per unit of 500 g / m with a cross wrapper weber.²Web (Wa1). Separately, 50 parts of polyethylene as a sea component and 50 parts of polyethylene terephthalate as an island component are melt-spun in the same melt system to obtain an ultrafine fiber generating type fiber (b1) having 1000 islands in the fiber cross section and a single fiber fineness of 30 denier. Produced, stretched 2.5 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and then weighted with a cross wrapper webber 600 g / m²Web (Wb1). Next, the web (Wa1) and the web (Wb1) are overlapped with each other, and the basis weight is about 1250 g / m by needle punching.²The fiber entangled nonwoven fabric. The needle has a first barb located at a position 5 mm from the tip, and has a piercing depth of 8 mm from the web (Wa1) surface and a piercing depth of 4.5 mm from the web (Wb1) surface, each 600 punches / cm.², Total 1200 punch / cm²Processed. Subsequently, the nonwoven fabric was heated in a dryer at 120 ° C., and pressed with two rolls in a state where the polyethylene was softened, thereby smoothing the surface and adjusting the thickness to 3.2 mm.
[0024]
This nonwoven fabric is impregnated with a solution comprising 12 parts by weight of a polyurethane composition mainly composed of polyester-based polyurethane and 88 parts by weight of dimethylformamide, wet-coagulated to obtain a porous state, and then washed with water to extract polyethylene in the fiber. This was removed to obtain a fibrous base material having a thickness of 2.0 mm consisting of a layer of 6-nylon ultrafine fiber bundled fiber and polyurethane and a layer of polyethylene terephthalate ultrafine fiber bundled fiber and polyurethane. In this substrate, the weight ratio of fiber to polyurethane was 47:53. The average thickness of the ultrafine fibers constituting the 6-nylon ultrafine fiber bundle fiber is 0.003 denier, while the average thickness of the ultrafine fibers constituting the polyethylene terephthalate ultrafine fiber bundle fiber is 0.006 denier. It was.
After buffing the surface mainly composed of the polyester ultrafine fiber (b1) in this substrate and adjusting the thickness to 1.8 mm, the surface composed of the nylon ultrafine fiber (a1) is processed with an emery buffing machine. A fiber raised surface was formed. At this time, the ratio (A) / (B) of the nylon ultrafine fiber substrate thickness (A) to the polyester fiber substrate thickness (B) was 0.9.
Subsequently, a polyurethane mainly composed of polyurethane obtained by polymerization from polycarbonate diol, polytetramethylene glycol, polyethylene glycol, and 4,4′-dicyclohexylmethane diisocyanate is formed on the surface of the dried substrate made of nylon ultrafine fibers (a1). The polyurethane composition solution, which was blackened by adding carbon black, was coated on a release paper and dried to obtain a film having a thickness of 40 microns. On top of that, a mixed liquid composed of a two-component polyurethane, a polyisocyanate curing agent, an amine catalyst, and a solvent is applied as an adhesive layer, dried, and pressed onto the fibrous substrate in a state having adhesiveness immediately after drying. And pasted together. After leaving it at 60 ° C. for 48 hours, the release paper was peeled off and used as a satchel artificial leather for the main body crown, front part, shoulder strap part, and heel part. The school bag product was full of luxury, with fine crown creases, good cushioning and excellent fit.
[0025]
Example 2
50 parts by weight of polyethylene as a sea component and 50 parts by weight of 6-nylon as an island component are melt-spun in the same melt system to obtain an ultrafine fiber-generating fiber having an average number of islands in the fiber cross section of about 300 and a single fiber fineness of 10 denier. Manufactured. The composite fiber is stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and weight per unit of 500 g / m with a cross wrapper weber.²Web (Wa2). Separately, 50 parts by weight of polyethylene as a sea component and 50 parts by weight of polyethylene terephthalate as an island component are melt-spun in the same melt system to obtain ultrafine fiber-generating fibers having an average number of islands of 700 in the fiber cross section and a single fiber fineness of 10 denier. Manufactured. The composite fiber is stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and weight per unit of 400 g / m with a cross wrapper weber.²Web (Wb2). Next, the web (Wa2) and the web (Wb2) are separately needle punched, and the basis weight is about 550 g / m.²450 g / m²The fiber entangled nonwoven fabric. As for the needle, in any nonwoven fabric, the first barb is located at a position 5 mm from the tip, and the piercing depth is 4.5 mm and each 600 punches / cm.², Total 1200 punch / cm²Processed. Subsequently, this nonwoven fabric was heated in a dryer at 120 ° C., and pressed with two rolls in a state where the polyethylene was softened to adjust the thickness to 1.4 mm and 1.2 mm.
[0026]
This nonwoven fabric is impregnated with a solution composed of 12 parts by weight of a polyurethane composition mainly composed of polyester-based polyurethane and 88 parts by weight of dimethylformamide, coagulated and washed with water, and then the polyethylene in the fiber is extracted and removed. A fibrous base material having a thickness of 0.9 mm made of bundle fibers and polyurethane and a thickness of 0.7 mm made of polyethylene terephthalate ultrafine fiber bundle fibers and polyurethane was obtained. The average thickness of the ultrafine fibers constituting the 6-nylon ultrafine fiber bundle fiber was 0.006 denier, while the average thickness of the ultrafine fibers constituting the polyethylene terephthalate ultrafine fiber bundle fiber was 0.0025 denier. .
6-Nylon and polyethylene terephthalate ultrafine fiber substrate buffed on both sides, and after adjusting the thickness to 0.85 mm and 0.65 mm, respectively, the surface comprising 6-nylon ultrafine fiber substrate (a2) Was treated with an emery buffing machine to form a fine fiber raised surface, and further subjected to a relaxation treatment in hot water.
Thereafter, an adhesive was applied to the ultrafine fibrous base material of 6-nylon and polyethylene terephthalate with a gravure, and then adhered to obtain a 1.5 mm fibrous base material.
At this time, the ratio (A) / (B) of the nylon ultrafine fiber substrate thickness (A) to the polyester fiber substrate thickness (B) was 1.15.
Hereinafter, it processed like Example 1 and used for the main body crown part, the front stage part, the shoulder strap part, and the heel part as an artificial leather sheet for school bags. The school bag products are unique in quality because of their high quality, fine creases in the crown, and cushioning that is not found in other school bags.
[0027]
Example 3
The fibrous base material was treated in the same manner as in Example 2, and then the surface of the dried substrate made of nylon ultrafine fibers (a2) was coated with polycarbonate diol, polytetramethylene glycol, polyethylene glycol, 4,4′- A polyurethane composition solution prepared by adding carbon black, a polyisocyanate curing agent, an amine catalyst, and a solvent to a polyurethane mainly composed of polyurethane obtained by polymerization from dicyclohexylmethane diisocyanate is coated on release paper. And dried to obtain a film having a thickness of 40 microns. On top of that, a mixed liquid consisting of a two-component polyurethane, a polyisocyanate curing agent, an amine catalyst, and a solvent is applied as an adhesive layer, dried, and pressed onto the fibrous substrate in a state of having adhesiveness immediately after drying. And pasted together. After leaving it at 60 ° C. for 48 hours, the release paper was peeled off and used as a satchel artificial leather for the main body crown, front part, shoulder strap part, and heel part. The school bag product is unique because it has excellent scratch resistance, is not easily scratched, has a high-class feel, has a fine crown crease, and has a cushioning property not found in other school bags. It was a workmanship.
[0028]
Comparative Example 1
50 parts by weight of polyethylene as a sea component and 50 parts by weight of 6-nylon as an island component are melt-spun in the same melt system, and the average number of islands in the fiber cross section is about 4000, and the fine fiber generation type fiber having a single fiber fineness of 10 denier ( a1 ′) was produced. The composite fiber is stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and weight per unit of 500 g / m with a cross wrapper weber.²Web (Wa1 '). Separately, 50 parts of polyethylene as a sea component and 50 parts of 6-nylon as an island component are melt-spun in the same melt system, and the number of islands in the fiber cross section is about 400, and the fine fiber generation type fiber having a single fiber fineness of 10 denier ( b1 '), stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and then weighted with a cross wrapper webber 600 g / m²Web (Wb1 '). Next, the web (Wa1 ') and the web (Wb1') are superposed on each other, and the basis weight is about 1100 g / m by needle punching.²The fiber entangled nonwoven fabric. The needle has a first barb at a position 5 mm from the tip, 600 mm each with a piercing depth of 8 mm from the web (Wa1 ′) surface and a piercing depth of 4.5 mm from the web (Wb1 ′) surface. / Cm², Total 1200 punch / cm²Processed. Subsequently, this non-woven fabric was heated in a dryer at 120 ° C., and pressed with two rolls in a state where the polyethylene was softened to adjust the thickness to 3.2 mm.
[0029]
This nonwoven fabric is impregnated with a solution comprising 12 parts by weight of a polyurethane composition mainly composed of polyester-based polyurethane and 88 parts by weight of dimethylformamide. A fibrous substrate having a thickness of 2.0 mm made of fiber bundle fibers and polyurethane was obtained.
After buffing the surface mainly composed of ultrafine fibers (b1 ′) of this substrate and adjusting the thickness to a thickness of 1.8 mm, the surface composed of ultrafine fibers (a1 ′) is processed with an emery buffing machine. A fiber napped surface was formed, and further relaxed in hot water.
Subsequently, a polyurethane mainly composed of polyurethane obtained by polymerizing polycarbonate diol, polytetramethylene glycol, polyethylene glycol, and 4,4′-dicyclohexylmethane diisocyanate on the surface of the dried substrate made of ultrafine fibers (a1 ′). The polyurethane composition solution, which was blackened by adding carbon black, was coated on a release paper and dried to obtain a film having a thickness of 20 microns. On top of that, a mixed liquid consisting of a two-component polyurethane, a polyisocyanate curing agent, an amine catalyst, and a solvent is applied as an adhesive layer, dried, and pressed onto the fibrous substrate in a state of having adhesiveness immediately after drying. And pasted together. After leaving it at 60 ° C. for 48 hours, the release paper was peeled off and used as a satchel artificial leather for the main body crown, front part, shoulder strap part, and heel part. School bag products have rough wrinkles at the crown and are difficult to remove. Although the texture is soft and cushioning is good, there is no waist, the setability is poor, and it tends to be out of shape.
[0030]
Comparative Example 2
50 parts by weight of polyethylene as a sea component and 50 parts by weight of polyethylene terephthalate as an island component are melt-spun in the same melt system, and an ultrafine fiber generating fiber (a2 ′) having an average number of islands of about 1000 in the fiber cross section and a single fiber fineness of 20 denier. ) Was manufactured. The composite fiber was stretched 2.5 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and weight per unit of 500 g / m with a cross wrapper weber.²Web (Wa2 '). Separately, 50 parts of polyethylene as a sea component and 50 parts of polyethylene terephthalate as an island component are melt-spun in the same melt system, and the number of islands in the fiber cross section is about 600, and the fine fiber generating fiber (b2) having a single fiber fineness of 10 denier. '), Stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and then weighed 600 g / m with a cross wrapper weber²Web (Wb2 '). Next, the web (Wa2 ') and the web (Wb2') are stacked one above the other, and the basis weight is about 1200 g / m by needle punching.²The fiber entangled nonwoven fabric. The needle has a first barb at a position 5 mm from the tip, 600 mm each with a piercing depth of 8 mm from the web (Wa2 ′) surface and a piercing depth of 4.5 mm from the web (Wb2 ′) surface. / Cm², Total 1200 punch / cm²Processed. Subsequently, this non-woven fabric was heated in a dryer at 120 ° C. and pressed with two rolls in a state where the polyethylene was softened to adjust the thickness to 3.0 mm.
[0031]
This nonwoven fabric is impregnated with a solution comprising 12 parts by weight of a polyurethane composition mainly composed of polyester-based polyurethane and 88 parts by weight of dimethylformamide, coagulated and washed with water, and then the polyethylene in the composite fiber is extracted and removed. A 1.8 mm-thick fibrous substrate made of fiber bundle fibers and polyurethane was obtained.
After buffing the surface mainly composed of ultrafine fibers (b2 ′) of this substrate and adjusting the thickness to 1.8 mm, the surface composed of the ultrafine fibers (a2 ′) is treated with an emery buffing machine. A fiber napped surface was formed, and further relaxed in hot water.
Subsequently, a polyurethane mainly composed of polyurethane obtained by polymerizing polycarbonate diol, polytetramethylene glycol, polyethylene glycol, and 4,4′-dicyclohexylmethane diisocyanate on the surface of the dried substrate made of ultrafine fibers (a2 ′). The polyurethane composition solution, which was blackened by adding carbon black, was coated on a release paper and dried to obtain a film having a thickness of 20 microns. On top of that, a mixed liquid consisting of a two-component polyurethane, a polyisocyanate curing agent, an amine catalyst, and a solvent is applied as an adhesive layer, dried, and pressed onto the fibrous substrate in a state of having adhesiveness immediately after drying. And pasted together. Thereafter, the mold was left at 60 ° C. for 48 hours, and then the release paper was peeled off to obtain artificial leather with silver.
Thereafter, it was used in the same manner as in Example 1 for the main body crown portion, the front step portion, the shoulder strap portion, and the heel portion as the artificial leather for the satchel. School bag products have too deep creases in the crown. The texture is too hard to handle. The fit of the product is lacking.
[0032]
Comparative Example 3
The fibrous base material was treated in the same manner as in Example 2, and then the surface of the dried substrate made of nylon ultrafine fibers (a2) was coated with polycarbonate diol, polytetramethylene glycol, polyethylene glycol, 4,4′- A polyurethane composition solution obtained by polymerizing from dicyclohexylmethane diisocyanate and containing polyurethane mainly composed of polyurethane was added with carbon black and a solvent, and the resulting mixture was coated on a release paper and dried to a thickness of 600 microns. A film was obtained. On top of that, a mixed liquid consisting of a two-component polyurethane, a polyisocyanate curing agent, an amine catalyst, and a solvent is applied as an adhesive layer, dried, and pressed onto the fibrous substrate in a state of having adhesiveness immediately after drying. And pasted together. After leaving it at 60 ° C. for 48 hours, the release paper was peeled off and used as a satchel artificial leather for the main body crown, front part, shoulder strap part, and heel part. For school bag products, the folds of the crown are smooth and the marks of the creases are less likely to remain. However, the product weight increases from the 600 micron film, which is not preferable. In addition, the surface cushioning is eliminated and the finish is less characteristic.
[0033]
Comparative Example 4
50 parts by weight of polyethylene as a sea component and 50 parts by weight of 6-nylon as an island component are melt-spun in the same melt system, and the average number of islands in the fiber cross section is about 600, and the fine fiber generation type fiber having a single fiber fineness of 10 denier ( a4 ′) was produced. This composite fiber is stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and weight per unit with a cross wrapper webber of 200 g / m.²Web (Wa4 '). Separately, 50 parts of polyethylene as a sea component and 50 parts of polyethylene terephthalate as an island component are melt-spun in the same melt system, and the number of islands in the fiber cross section is about 1000, and the single fiber fineness is 30 deniers. '), Stretched 2.5 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and then weighted with a cross wrapper webber of 1000 g / m²Web (Wb4 '). Next, the web (Wa4 ') and the web (Wb4') are stacked one above the other, and the basis weight is about 1250 g / m by needle punching.²The fiber entangled nonwoven fabric. The needle has a first barb at a position 5 mm from the tip, 600 mm each with a piercing depth of 8 mm from the web (Wa4 ′) surface and a piercing depth of 4.5 mm from the web (Wb4 ′) surface. / Cm², Total 1200 punch / cm²Processed. Subsequently, the nonwoven fabric was heated in a dryer at 120 ° C. and pressed with two rolls in a state where the polyethylene was softened, and the thickness was adjusted to 3.3 mm.
[0034]
This nonwoven fabric is impregnated with a solution composed of 12 parts by weight of a polyurethane composition mainly composed of polyester-based polyurethane and 88 parts by weight of dimethylformamide, coagulated and washed with water, and then the polyethylene in the fiber is extracted and removed. A fibrous base material having a thickness of 2.1 mm made of bundle fibers and polyurethane was obtained.
After buffing the surface mainly composed of polyester microfibers (b4 ′) of this substrate and adjusting the thickness to 1.9 mm, the surface composed of nylon microfibers (a4 ′) was treated with an emery buffing machine. Thus, an ultrafine fiber raised surface was formed. At this time, the ratio (A) / (B) of the nylon ultrafine fiber substrate thickness (A) to the polyester fiber substrate thickness (B) was 0.25.
Subsequently, a polyurethane base obtained by polymerizing polycarbonate diol, polytetramethylene glycol, polyethylene glycol, and 4,4′-dicyclohexylmethane diisocyanate on the surface of the dried base made of nylon ultrafine fibers (a4 ′) is mainly used. A polyurethane composition solution prepared by adding carbon black to polyurethane and adjusting the color to black was applied onto a release paper and dried to obtain a film having a thickness of 40 microns. On top of that, a mixed liquid consisting of a two-component polyurethane, a polyisocyanate curing agent, an amine catalyst, and a solvent is applied as an adhesive layer, dried, and pressed onto the fibrous substrate in a state of having adhesiveness immediately after drying. And pasted together. After leaving it at 60 ° C. for 48 hours, the release paper was peeled off and used as a satchel artificial leather for the main body crown, front part, shoulder strap part, and heel part. The school bag product has deep and large crown wrinkles. The texture is too hard to handle. The fit of the product is lacking.
[0035]
Comparative Example 5
50 parts by weight of polyethylene as a sea component and 50 parts by weight of 6-nylon as an island component are melt-spun in the same melt system to obtain an ultrafine fiber-generating fiber having an average number of islands in the fiber cross section of about 300 and a single fiber fineness of 10 denier. Manufactured. The fiber was stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and then weight per unit 1000 g / m with a cross wrapper weber.²Web (Wa5 '). Separately, 50 parts by weight of polyethylene as a sea component and 50 parts by weight of polyethylene terephthalate as an island component are melt-spun in the same melt system, and the average number of islands in the fiber cross section is about 700, and the fine fiber generating fiber having a single fiber fineness of 10 denier. Manufactured. This composite fiber is stretched 3.0 times, crimped, cut to a fiber length of 51 mm, defibrated with a card, and weight per unit with a cross wrapper webber of 200 g / m.²Web (Wb5 '). Next, the web (Wa5 ') and the web (Wb5') are separately needle-punched to have a basis weight of about 1100 g / m.²210 g / m²The fiber entangled nonwoven fabric. As for the needle, in any nonwoven fabric, the first barb is 5 mm from the tip, and the piercing depth is 8 mm, each 600 punch / cm.², Total 1200 punch / cm²Processed. Subsequently, the nonwoven fabric was heated in a dryer at 120 ° C., and pressed with two rolls in a state where the polyethylene was softened, and the thickness was adjusted to 2.80 mm and 0.35 mm.
[0036]
This nonwoven fabric is impregnated with a solution composed of 12 parts by weight of a polyurethane composition mainly composed of polyester-based polyurethane and 88 parts by weight of dimethylformamide, coagulated and washed with water, and then the polyethylene in the fiber is extracted and removed to obtain a 6-nylon ultrafine fiber. A fibrous base material having a thickness of 1.55 mm made of bundle fibers and polyurethane and a 0.25 mm thickness made of polyethylene terephthalate ultrafine fiber bundle fibers and polyurethane was obtained.
After 6-nylon and polyethylene terephthalate ultrafine fiber base material are buffed on both sides, the thickness is adjusted to 0.85 mm and 0.65 mm, respectively, and then 6-nylon ultrafine fiber base material (a5 ′) is formed. The surface was treated with an emery buffing machine to form a fine fiber raised surface, and further subjected to a relaxation treatment in hot water.
Thereafter, an ultrafine fibrous base material of 6-nylon and polyethylene terephthalate was bonded with a gravure to obtain a 1.5 mm fibrous base material.
At this time, the ratio (A) / (B) of the nylon ultrafine fiber substrate thickness (A) to the polyester fiber substrate thickness (B) was 6.0.
Hereinafter, it processed like Example 1 and was used for a main part crown part, a front stage part, a shoulder strap part, and a heel part as an artificial leather sheet for school bags. School bag products have rough wrinkles at the crown and are difficult to remove. Although the texture is soft and cushioning is good, there is no waist, the setability is poor, and it tends to be out of shape.
[0037]
The evaluation results of Examples 1 to 3 and Comparative Examples 1 to 5 are shown in Table 1. The determination was performed by the following method.
[Smoothness of the surface]
Evaluation results by 20 panelists selected arbitrarily
5: Good smoothness after bending
4: Slightly uneven after folding, but good with flat cloth
3: Conspicuous irregularities after folding
2: Slightly uneven in flat cloth
1: Unevenness is conspicuous in flat cloth
[0038]
[Cushioning]
Evaluation results by 20 panelists selected arbitrarily
5: Excellent sense of fullness and inclination, and excellent cushioning
Compared with 4: 5, it is slightly slanted but good
3: There is a sense of fulfillment but a slight sense of inclination
2: There is a sense of fulfillment but no sense of inclination
1: There is no sense of fulfillment and the texture is too hard
[0039]
[Surface wrinkles]
Evaluation results by 20 panelists selected arbitrarily
5: Fine wrinkles when bent
4: Wrinkle when bent is slightly finer than 1
3: Wrinkles when bent are rough
2: Wrinkles are deep when bent
1: Wrinkles during bending become large wrinkles
[0040]
[Table 1]

[0041]
【The invention's effect】
As described above, a fibrous base material in which a surface layer is a polyurethane resin having a thickness of 30 to 400 μm and an intermediate layer is impregnated and solidified with a porous polyurethane resin on a nylon ultrafine fiber nonwoven fabric having a fineness of 0.1 to 0.0001 denier. A) and the back layer are composed of a fibrous base material (B) obtained by impregnating and solidifying a porous polyurethane resin into a polyester ultrafine fiber nonwoven fabric having a fineness of 0.1 to 0.0001 denier, and the thickness ratio between the intermediate layer and the back layer By using the artificial leather laminated so that (A) / (B) is 0.5 to 5, a material for a satchel having a smooth and good texture appearance and a large cushioning property can be produced. .

Claims (3)

At least the following surface layer (1), the following intermediate layer (A) and the back surface layer (B) are laminated, and the thickness ratio (A) / (B) between the intermediate layer and the back surface layer is 0.5 to 5. Artificial leather characterized by being.
(1) A resin layer having a thickness of 30 to 400 μm formed of a polyurethane resin,
(A) a fibrous layer obtained by impregnating and solidifying a porous polyurethane resin on a nylon ultrafine fiber nonwoven fabric having a fineness of 0.1 to 0.0001;
(B) a fibrous layer obtained by impregnating and solidifying a porous polyurethane resin on a polyester ultrafine fiber nonwoven fabric having a fineness of 0.1 to 0.0001 denier, The artificial leather according to claim 1, wherein the resin constituting the surface layer (1) is crosslinked. A school bag in which the artificial leather according to claim 1 or 2 is used for a crown.