WO2017082273A1

WO2017082273A1 - Artificial leather substrate, artificial leather, and method for manufacturing same

Info

Publication number: WO2017082273A1
Application number: PCT/JP2016/083176
Authority: WO
Inventors: 伸一吉本; 友山田; 中山　公男; 和洋米澤; 正勝西原
Original assignee: 株式会社クラレ; 小松精練株式会社
Priority date: 2015-11-10
Filing date: 2016-11-09
Publication date: 2017-05-18
Also published as: JPWO2017082273A1; TW201723271A; JP6792562B2

Abstract

An artificial leather substrate including fiber-entangled bodies of an ultra-fine nylon fiber of 1.5 dtex or less, and a polymeric elastomer impregnated in and applied to the fiber-entangled bodies, the artificial leather substrate having an apparent density of 0.3-0.55 g/m³, a vertical/horizontal ratio at 20% strength of 0.5-1.25, and tear strength per 1 mm of thickness of 2.5 kgf/mm or more. Also, a method for manufacturing the artificial leather substrate, the method being provided with: a step for preparing the unprocessed artificial leather substrate, which includes the fiber-entangled bodies of the nylon ultra-fine fiber of 1.5 dtex or less and the polymeric elastomer impregnated in and applied to the fiber-entangled bodies, and has an apparent density of 0.2-0.5 g/m ³; and a step for immersing the unprocessed artificial leather substrate in a treatment fluid that includes benzyl alcohol, whereby the unprocessed artificial leather substrate is caused to shrink so that the apparent shrinkage ratio is 5-40%.

Description

Artificial leather substrate, artificial leather and method for producing the same

The present invention relates to an artificial leather having a texture and appearance close to natural leather.

Conventionally, natural leather has been used as a high-quality material in various fields such as clothing, bags, shoes, interior materials, and vehicle interior materials. Since natural leather is expensive, artificial leather is widely used as a substitute. Artificial leather is mainly composed of an artificial leather base material in which a non-woven fabric is filled with a polymer elastic body. Silver-like artificial leather with a skin layer provided on the surface of such an artificial leather base material and suede-like artificial leather obtained by raising the fibers on the surface of the artificial leather base material are known.

Conventionally known general artificial leather bases have a lot of voids that are not filled with a polymer elastic body, so that they are less dense and fuller than natural leather. For this reason, when folded, it bends without buckling and bends as if it is called “poki folding”. In addition, as a method for producing a silver-coated artificial leather having a skin layer on the surface of an artificial leather substrate, a film for forming the skin layer is formed on a release paper, and the skin layer is artificially formed through an adhesive layer. There is known a dry surface forming method for bonding to the surface of a leather substrate. In addition, a polymer elastic resin solution for forming a silver resin layer on the surface of the artificial leather base material is applied by a method such as spray coating or reverse coating, and the resin solution is dried to form a silver resin layer. A direct coating method for forming a film is also known. In the dry surface-forming method, the skin layer and the artificial leather base material are bonded to each other through the adhesive layer, so that the skin layer may be peeled off during use. Since the direct coating method does not adhere the skin layer with an adhesive layer as in the dry surface-forming method, it is excellent in the sense of unity between the silver surface resin layer and the artificial leather base material, and is also excellent in productivity. However, when the direct coating method is applied to an artificial leather base material having a large number of voids, there is a drawback that the liquid sinks inside or the shape of the nonwoven fabric is raised on the surface. These disadvantages of the direct coating method can be solved by increasing the thickness of the silver surface resin layer, but when the thickness of the silver surface resin layer is increased, it tends to move away from the texture of natural leather because it becomes a rubber-like texture. was there.

In order to solve the above-mentioned problems, there is a method of increasing the content of the polymer elastic body in the nonwoven fabric to reduce the voids. When such means are used, artificial leather is formed by the polymer elastic body. There was a problem that the feeling of resilience of the base material was increased, and the rubber-like and stiff texture became prominent, leaving the texture of natural leather.

By the way, conventionally, a technique for softening a nylon fiber by swelling it with benzyl alcohol has been known (see Patent Documents 1 and 2 below). By such a method, it has been known that a fabric having a soft texture can be obtained by swelling nylon fibers with benzyl alcohol.

JP 2003-089984 A Japanese Patent Laid-Open No. 2003-099883

An object of the present invention is to provide an artificial leather that has both a sense of fulfillment and flexibility as natural leather.

One aspect of the present invention includes a fiber entanglement of nylon ultrafine fibers of 1.5 dtex or less and a polymer elastic body impregnated in the fiber entanglement, and has an apparent density of 0.3 to 0.55 g / m ³ . The artificial leather base material has a 20% strength ratio in the vertical / horizontal direction of 0.5 to 1.25, and a tear strength per 1 mm thickness of 2.5 kgf / mm or more. A homogenous artificial leather base material with a relatively high apparent density and a 20% strong vertical / horizontal ratio of 0.5 to 1.25 provides a high sense of fullness and few large voids. A dense and highly smooth surface can also be formed. In addition, when the tear strength per 1 mm thickness is 2.5 kgf / mm or more, it is possible to maintain a supple texture despite a high sense of fulfillment. In addition, when the silver surface resin layer is formed using the direct coating method, the resin liquid for forming the silver surface resin layer is less likely to sink into the artificial leather base material. A surface resin layer can be formed.

In addition, the artificial leather base material preferably has an elongation of 6.5% or less in the vertical direction when it becomes 1.8 kgf at a tensile speed of 200 mm / min.

Further, another aspect of the present invention is a synthetic leather with a silver tone provided with a silver resin layer on at least one surface of the artificial leather base material, or a suede-like artificial leather with at least one surface of the artificial leather base material raised. is there. Further, the elongation set rate of the silver-finished artificial leather described later is preferably 20 to 50%.

Another aspect of the present invention includes a fiber entanglement of nylon ultrafine fibers of 1.5 dtex or less and a polymer elastic body impregnated in the fiber entanglement, and has an apparent density of 0.2 to 0.5 g. / M ³ to prepare an untreated artificial leather substrate, and immersing the untreated artificial leather substrate in a treatment liquid containing benzyl alcohol so that the apparent shrinkage rate is 5 to 40%. And a step of shrinking the artificial leather substrate. According to such a manufacturing method, the artificial leather base as described above can be obtained.

The step of shrinking so that the apparent shrinkage rate is 5 to 40% is a step of immersing an untreated artificial leather substrate in a treatment solution containing 10 to 300 g / L of benzyl alcohol at 80 to 110 ° C. It is preferable.

Another aspect of the present invention is a step of preparing an artificial leather substrate obtained by the above-described method for producing an artificial leather substrate, and a silver surface resin by direct coating on at least one surface of the artificial leather substrate. It is a manufacturing method of the artificial leather with a silver tone provided with the process of forming a layer.

According to the present invention, it is possible to obtain an artificial leather base material having a high solidity and a supple texture like natural leather, and capable of forming a dense and smooth surface with few large voids. Moreover, when forming a silver surface resin layer using a direct coat method, the artificial leather base material which does not sink the resin liquid for forming a silver surface resin layer too much is obtained.

The artificial leather base material and the artificial leather using the same according to the present embodiment will be described in detail along with an example of their manufacturing method. In the production of the artificial leather substrate of the present embodiment, first, a fiber entanglement of nylon ultrafine fibers (hereinafter also simply referred to as ultrafine fibers) of 1.5 dtex or less, and a polymer elastic body impregnated in the fiber entanglement and To produce an untreated artificial leather substrate having an apparent density of 0.2 to 0.5 g / m ³ .

In the production of the fiber entangled body, first, a thermoplastic resin constituting the sea component of the sea-island type composite fiber that can be selectively removed, and nylon constituting the island component of the sea-island type composite fiber that is a resin component that forms ultrafine fibers. A sea-island type composite fiber is obtained by melt-spinning and stretching the resin. In this embodiment, the case where the sea-island type composite fiber is used will be described in detail. However, even if an ultrafine fiber-generating fiber other than the sea-island type composite fiber is used, it is possible to directly Ultra fine fibers may be spun.

As the thermoplastic resin for the sea component, a thermoplastic resin that is different from the island component resin in solubility in a solvent or decomposability in a decomposing agent is selected. Specific examples of the thermoplastic resin constituting the sea component include polyethylene, polypropylene, polystyrene, ethylene propylene resin, ethylene vinyl acetate resin, styrene ethylene resin, styrene acrylic resin, and the like.

As the thermoplastic resin, which is a resin component that forms island components and forms ultrafine fibers, a nylon resin is used. Specific examples of the nylon resin include 6-nylon, 6,6-nylon, 10-nylon, 11-nylon, 12-nylon, 6,12-nylon, and the like. These may be used alone or in combination of two or more.

As a method for producing a fiber entangled body of ultrafine fibers, for example, a sea island type composite fiber is melt spun to produce a web, the web is entangled, and then sea components are selectively removed from the sea island type composite fiber. Examples thereof include a method for forming ultrafine fibers. As a method for producing a web, a long-fiber sea-island composite fiber spun by a spunbond method or the like is collected on a net without being cut to form a long-fiber web, or a long fiber is cut into staples. And a method of forming a short fiber web. Among these, a long fiber web is particularly preferable because it is excellent in denseness and fullness. In addition, the formed web may be subjected to a fusion treatment in order to impart shape stability.

Usually, in any process from removing sea components of the web made of sea-island type composite fibers to forming ultrafine fibers, fiber shrinkage treatment such as entanglement treatment, heat shrinkage treatment with water vapor, etc. It is preferable to apply a crystallization treatment. As the entanglement treatment, for example, a method in which about 5 to 100 layers of the obtained web are stacked and the web is entangled using a known nonwoven fabric manufacturing method such as needle punching or high-pressure water flow treatment is used.

The sea component of the sea-island type composite fiber can be removed by extraction or decomposition at an appropriate stage after the web is formed. By such extraction removal or decomposition removal, the sea-island type composite fibers are made into ultrafine fibers to form fiber bundles of ultrafine fibers.

The fineness of the ultrafine fiber is 1.5 dtex or less, 0.001 to 1.2 dtex, further 0.002 to 1.0 dtex, especially 0.005 to 0.8 dtex, and more particularly 0.005 to 0.5 dtex. It is preferable that When the fineness is too high, the feeling of denseness becomes insufficient, and a fiber entangled body with a feeling of coarseness tends to be obtained. Further, fibers with too low fineness are difficult to produce, and the fibers tend to converge without being unraveled, and the resulting fiber entanglement tends to increase in rigidity.

The fiber entangled body is impregnated with a polymer elastic body in any step. The ratio of the polymer elastic body impregnated is preferably 5 to 25 parts by mass, more preferably 8 to 20 parts by mass with respect to 100 parts by mass of the ultrafine fibers. When the amount of the elastic polymer is too large, the resilience is increased and the rubber feeling is increased, so that the flexibility tends to decrease. On the other hand, when the amount is too small, creases remain when bent, and the quality tends to deteriorate.

The polymer elastic body is obtained by impregnating a fiber entangled fiber of an ultrafine fiber generating fiber or a fiber entangled fiber made of ultrafine fiber with a resin solution such as a solution of a polymer elastic body or an emulsion, and then coagulating the polymer elastic body. Impregnation is provided. The polymer elastic body may be a porous polymer elastic body or a non-porous polymer elastic body.

Specific examples of such a polymer elastic body include, for example, polyurethane, acrylic elastic body, silicone elastic body, diene elastic body, nitrile elastic body, fluorine elastic body, polystyrene elastic body, and polyolefin elastic body. Body, polyamide elastic body, halogen elastic body and the like. These may be used alone or in combination of two or more. Among these, polyurethane is preferable from the viewpoint of excellent wear resistance and mechanical properties.

Specific examples of polyurethane include polycarbonate polyurethane, polyester polyurethane, polyether polyurethane, polycarbonate / ether polyurethane, and the like.

The fiber entangled body or impregnated polymer elastic body may contain a pigment or be dyed with a dye. The pigment may be fixed to the fiber entangled body with a polymer elastic body serving as a binder, or may be kneaded with the fiber itself forming the fiber entangled body, but it should be fixed to the fiber entangled body with a polymer elastic body. Is preferable from the viewpoint of easy coloring and color matching.

The kind of pigment is not particularly limited. Specific examples thereof include, for example, organic pigments such as diketopyrrolopyrrole pigments, quinacridone pigments, anthraquinone pigments, inorganic pigments such as iron oxide for red to orange, and isoindoline for yellow Organic pigments such as pigments, quinophthalone pigments, condensed azo pigments, azo complex pigments, inorganic pigments such as bismuth yellow and titanium yellow; copper to phthalocyanine pigments, cobalt blue, bitumen, ultra Inorganic pigments such as marine; examples of the black type include carbon black. Such pigments may be used singly or in combination of two or more in order to adjust the target color.

In this way, an untreated artificial leather substrate containing a fiber entanglement of polyamide ultrafine fibers of 1.5 dtex or less and a polymer elastic body impregnated in the fiber entanglement is produced. The obtained untreated artificial leather base material is subjected to thickness adjustment or flattening treatment by slicing treatment or buffing treatment as necessary. In this way, an untreated artificial leather substrate is prepared.

The thickness of the untreated artificial leather substrate is preferably about 0.15 to 3.0 mm, more preferably about 0.3 to 2.0 mm. In addition, the basis weight of the untreated artificial leather base material is preferably about 50 to 1650 g / m ² , and more preferably about 90 to 1100 g / m ² , from the viewpoint of obtaining an artificial leather base material with excellent fulfillment.

The apparent density of the untreated artificial leather substrate is 0.2 to 0.5 g / cm ³ , more preferably 0.25 to 0.4 g / cm ³ , particularly 0.3 to 0.4 g / cm ³ , It is preferable from the viewpoint that an artificial leather base material excellent in fulfillment can be obtained.

Next, the untreated artificial leather substrate is treated with a treatment liquid containing benzyl alcohol. Specifically, it is immersed at a temperature of 80 to 110 ° C. in a treatment solution containing 10 to 300 g / L of benzyl alcohol. By such treatment, the untreated artificial leather base material is shrunk so that the apparent shrinkage rate is preferably 5 to 40%, and the mechanical strength of the nylon ultrafine fiber is lowered to improve the flexibility.

In the method for manufacturing an artificial leather base material according to this embodiment, the concentration of benzyl alcohol in the treatment liquid and the temperature of the treatment liquid are important. That is, the artificial leather base material of this embodiment can be obtained by processing the untreated artificial leather base material under a predetermined concentration and temperature condition.

As the treatment liquid containing benzyl alcohol, an aqueous liquid such as an emulsion containing benzyl alcohol is preferably used. Further, the treatment liquid containing benzyl alcohol may contain an antifoaming agent, a softener in bath, a hit prevention agent, and the like. For the treatment with the treatment liquid containing benzyl alcohol, a drum dyeing machine, an atmospheric pressure zicker dyeing machine, a high pressure zicker dyeing machine, a liquid flow dyeing machine, or the like is used.

The concentration of benzyl alcohol in the treatment liquid is preferably 10 to 300 g / L, more preferably 30 to 150 g / L, and particularly preferably 50 to 100 g / L. The treatment temperature with the treatment liquid containing benzyl alcohol is preferably 80 to 110 ° C., more preferably 90 to 110 ° C., and particularly preferably 100 to 110 ° C. when the temperature is raised. If the concentration of benzyl alcohol is too high or the treatment temperature is too high, the untreated artificial leather base material will be sufficiently shrunk and tightened, but the sense of fulfillment will be improved. There is a tendency for the mechanical properties to decrease. On the other hand, when the concentration of benzyl alcohol is too low or the treatment temperature is too low, the untreated artificial leather base material does not sufficiently shrink and becomes difficult to tighten, and there is a tendency that a desired fullness cannot be obtained.

The treatment time of the untreated artificial leather substrate with the treatment liquid is preferably maintained at the maximum temperature for 5 to 180 minutes, more preferably 20 to 60 minutes, depending on the treatment temperature and the concentration of benzyl alcohol. When the processing time at the maximum temperature is less than 5 minutes, the effect of the processing cannot be sufficiently obtained, and when the processing time at the maximum temperature exceeds 180 minutes, the productivity is lowered.

Moreover, it is preferable to perform soaping after the treatment with the treatment liquid containing benzyl alcohol. The conditions for the soaping are not particularly limited. For example, the conditions include treatment with a soaping solution in which alkaline agent such as caustic soda, soda ash or sodium tripolyphosphate, surfactant or chelating agent is added to water at room temperature to about 100 ° C. It is done. In addition, it is preferable to perform the soaping a plurality of times. For example, a soaping solution to which an alkali agent or a surfactant is added is used for the first soaping, and the soaping for the second time is performed only with water. Is preferred. Further, after the treatment with the treatment liquid containing benzyl alcohol and the soaping, a post-treatment treatment such as dyeing may be performed as necessary.

By treating the untreated artificial leather base material with the treatment liquid containing benzyl alcohol, the untreated artificial leather base material shrinks to reduce the voids between the fibers. In addition, the mechanical strength of the nylon ultrafine fiber is reduced. In this way, the untreated artificial leather base material is changed to an artificial leather base material. The apparent shrinkage ratio of the untreated artificial leather substrate by the treatment at this time is preferably 5 to 40%, more preferably 10 to 25%, and particularly preferably 10 to 20%. The shrinkage rate is an average value of the shrinkage rates in the vertical direction and the horizontal direction. If the apparent shrinkage is too low, the fiber density of the ultrafine fibers contained in the untreated artificial leather substrate tends not to be sufficiently densified. Moreover, when the apparent shrinkage is too high, the mechanical strength of the ultrafine fibers contained in the untreated artificial leather substrate tends to be too low, and the mechanical properties such as tear strength tend to be too low.

The artificial leather base material thus obtained includes a fiber entanglement of nylon ultrafine fibers of 1.5 dtex or less and a polymer elastic body impregnated in the fiber entanglement, and has an apparent density of 0.3 to 0.00. a 55 g / m ^3, ratio of 20% strength in the longitudinal direction / transverse direction is 0.5 to 1.25 is tearing per 1mm thickness strength is 2.5 kgf / mm or more. Such an artificial leather base material has a sense of fullness and a supple texture like natural leather, and can form an extremely smooth surface.

The thickness of the artificial leather base material is not particularly limited, but is preferably about 0.1 to 3 mm, more preferably about 0.3 to 2 mm. Further, the basis weight of the artificial leather base material is preferably about 50 to 1650 g / m ² , more preferably about 90 to 1100 g / m ² , from the viewpoint of obtaining artificial leather with excellent solid feeling.

The apparent density of the artificial leather base material is 0.3 to 0.55 g / cm ³ , further 0.35 to 0.5 g / cm ³ , particularly 0.4 to 0.5 g / cm ^3. Is preferable from the viewpoint of obtaining an artificial leather base material excellent in a sense of fulfillment. When the apparent density of the artificial leather substrate is too low, the sense of fulfillment is insufficient, and when it is too high, the flexibility tends to decrease.

Further, the ratio of the vertical direction / width direction of 20% strength of the artificial leather base material is 0.5 to 1.25, 0.6 to 1.2, and further 0.8 to 1.2. preferable. Here, the ratio of the vertical direction / horizontal direction of 20% strength is usually measured by setting the advancing direction in the manufacturing process in which 20% strength is the highest as the vertical direction and the direction perpendicular to the vertical direction as the horizontal direction. 20% strength ratio. Since the artificial leather base material having such a 20% strength ratio in the vertical direction / horizontal direction is a homogeneous base material, it is difficult for large voids to exist on the surface.

The tear strength per 1 mm thickness of the artificial leather base material is 2.5 kgf / mm or more, preferably 3.0 to 8.0 kgf / mm, more preferably 3.0 to 6.0 kgf / mm. . In such a range, practically sufficient mechanical properties can be maintained. In addition, for each artificial leather base material, a test piece is prepared for each direction of an arbitrary direction, a direction rotated by 45 degrees with respect to the direction, and a direction rotated by 90 degrees with respect to the direction. The value obtained by dividing the maximum value of the measured tear strength by the thickness is defined as the tear strength per mm.

In the vertical direction, the elongation when the tensile speed is 1.8 mmf at 200 mm / min is 6.5% or less, more preferably 6.0%, and particularly preferably 5.0% or less. Here, the elongation rate in the vertical direction is the elongation rate when the vertical direction is 1.8 kgf when the vertical direction is the vertical direction and the tensile direction is 200 mm / min.

Artificial leather base material is subjected to thickness adjustment and flattening treatment by slicing or buffing treatment as necessary, stagnation softening treatment, blanking softening treatment, reverse seal brushing treatment, antifouling treatment, hydrophilic treatment Further, finishing treatment such as lubricant treatment, softener treatment, antioxidant treatment, ultraviolet absorber treatment, fluorescent agent treatment, flame retardant treatment and the like may be performed.

Also, such artificial leather base material is finished into a silver-tone artificial leather by providing a silver resin layer on the surface. Moreover, it is finished in suede-like artificial leather by raising the surface fibers of the fiber entangled body.

In addition, as a method of forming the silver surface resin layer on the artificial leather base material, a film for forming the skin layer is formed on the release paper, and the resin layer is adhered to the surface of the artificial leather base material through the adhesive layer. Silver by applying a dry surface-forming method or a polymer elastic resin solution for forming a silver resin layer on the surface of an artificial leather substrate by a method such as spray coating or reverse coating, and drying the resin solution. A direct coating method for forming a surface resin layer film is known. Among these, the direct coating method is preferable in terms of excellent productivity, but when applied to an artificial leather base material having many voids, the liquid may sink inside, or the shape of the nonwoven fabric may appear on the surface. There was a drawback of doing. These disadvantages of the direct coating method can be solved by increasing the thickness of the silver surface resin layer, but when the thickness of the silver surface resin layer is increased, it tends to move away from the texture of natural leather because it becomes a rubber-like texture. There is.

The artificial leather base material of the present embodiment is contracted and reduced in voids by being treated with a treatment liquid containing benzyl alcohol. Therefore, a surface having a dense fiber density and high smoothness can be formed. And since a resin liquid does not sink easily even if it uses a direct coat method with respect to such a surface, the silver surface resin layer which is not too thick can be formed.

Examples of the resin component for forming the silver surface resin layer include polyurethane, acrylic elastic body, silicone elastic body, diene elastic body, nitrile elastic body, fluorine elastic body, polystyrene elastic body, and polyolefin base. Examples include elastic bodies, polyamide-based elastic bodies, and halogen-based elastic bodies. Among these, polyurethane is preferable from the viewpoint of excellent wear resistance and mechanical properties. Further, the resin component for forming the silver surface resin layer may contain a colorant, an ultraviolet absorber, a surfactant, a flame retardant, an antioxidant, and the like, if necessary.

The thickness of the silver surface resin layer is preferably 10 to 1000 μm, more preferably 50 to 300 μm. The silver surface resin layer may have a laminated structure in which a plurality of layers such as a base coat layer, a colored layer, and a top coat layer are appropriately laminated. The silver surface resin layer may have a texture formed by embossing or the like.

Furthermore, it is preferable that the obtained artificial leather with silver tone has an elongation set rate defined as follows of 20 to 50%, more preferably 30 to 40%, from the viewpoint of excellent fulfillment.
[Expansion set rate]
A strip sample having a length of 20 cm and a width of 2.54 cm is prepared from the obtained silver-tone artificial leather. Then, a marked line with a distance between marked lines of 10 cm is drawn at a position of 5 cm from each end of the strip sample in the length direction. Then, the strip sample is hung so that the length direction becomes the vertical direction, a load of 8 kgf is applied for 10 minutes, and then the load is removed and left for 10 minutes. This operation is repeated 5 times, and the distance between marked lines (H1) with a load applied for 10 minutes in the fifth time and the distance between marked lines (H2) after leaving the load for 10 minutes are measured. The vertical direction of the manufacturing process was the vertical direction, the horizontal direction was the vertical direction, and three strip samples in each direction were measured, and an average value of a total of six H1 and H2 was obtained. Then, using the average value of H1 and H2, the expansion set rate is calculated by the following formula.
Elongation set rate (%) = [(H2-10) / (H1-10)] × 100
Moreover, when it is such an elongation set rate, when using a silver-tone artificial leather as a shoe, it is preferable from the point of obtaining a shoe that can be easily adapted to the foot like natural leather. When the elongation set rate is too low, it becomes difficult to become familiar with the shape of the foot when the manufactured shoes are worn, and the feeling of wearing tends to decrease. Further, when the elongation set rate exceeds 20%, the artificial leather with a silver tone is easily deformed into a state along the shape of the foot when the manufactured shoes are worn. In addition, when it exceeds 50%, there exists a tendency for a silver-tone artificial leather to become easy to elongate over time, and there exists a tendency for a clearance gap to be easily made between shoes and a foot.

When an untreated artificial leather substrate is treated with a treatment solution containing benzyl alcohol, the elongation set rate is 20% if the concentration of benzyl alcohol is less than 10 g / L even under conditions of 80 to 110 ° C. When the concentration of benzyl alcohol exceeds 300 g / L, the elongation set rate tends to exceed 50%.

The artificial leather thus obtained is preferably used as a leather-like material for shoes, clothing, gloves, bags, balls, interiors, vehicle interiors, and the like.

The present invention will be described more specifically with reference to examples. The scope of the present invention is not limited by the examples. In the following description, “part” or “%” is based on mass unless otherwise specified.

[Example 1]
6-Nylon and polyethylene are each melted in a single screw extruder, and the island component is 6-nylon, the sea component is high fluidity low density polyethylene, and the sea component / island component ratio is 50/50. The composite fiber was melt-spun with a composite spinning nozzle. The obtained yarn was drawn, crimped, and cut to obtain a staple having 3.5 dtex and a cut length of 51 mm. The obtained staples were passed through a card, made into a web by a cross wrapper method, and laminated. Next, a non-woven fabric having a basis weight of 530 g / m 2 was obtained by needle punching at a needle penetration density of 980 punch / cm ² .

And after heating the obtained nonwoven fabric, the polyethylene component was melt-fixed by pressing and the nonwoven fabric surface was made smooth. Then, a non-woven fabric having a smooth surface was impregnated with a 13% dimethylformamide (DMF) solution of polyester polyurethane, and then immersed in an aqueous DMF solution to solidify the polyurethane into a sponge. And after extracting and removing the sea component polyethylene of the sea-island type composite fiber with toluene at 95 ° C., the intermediate body of the artificial leather base material was obtained by drying. And both surfaces of the intermediate body were buffed using a 400th sandpaper to smooth the surface, thereby obtaining an untreated artificial leather substrate (a1). The untreated artificial leather base material (a1) is composed of a fiber entanglement of ultrafine fibers of 0.006 dtex and a polyurethane impregnated in the fiber entanglement, an apparent density of 0.353 g / cm ³ , a basis weight of 476 g / m ² , a thickness It was a 1.35 mm thick artificial leather substrate.

On the other hand, a processing liquid containing 60 g / L of benzyl alcohol was prepared by introducing an emulsified dispersion of benzyl alcohol into water, and the processing liquid was transferred to a drum dyeing machine. The untreated artificial leather base material (a1) is washed and relaxed, and then immersed in a treatment liquid in a drum dyeing machine. The temperature is raised from 20 ° C. to 110 ° C. in about 40 minutes, and then at 110 ° C. for 40 minutes. Immersion continued. Then, it was soaped and further washed twice with 80 ° C. hot water.

And the untreated artificial leather base material (a1) after soaping was dye | stained. For dyeing, a drum dyeing machine was used for dyeing treatment with a dye solution containing a black acid dye at 95 ° C. for 60 minutes, and after soaping, fix treatment using synthetic tannin was performed. And after drying at 100 degreeC, the artificial leather base material (A) dye | stained by performing a finishing set was obtained. The artificial leather base material (A) thus obtained is composed of a fiber entanglement of ultrafine fibers of 0.006 dtex and polyurethane impregnated in the fiber entanglement, with an apparent density of 0.43 g / cm ³ and a basis weight of 636 g. This was an artificial leather base material having a thickness of 1.48 mm / m ² . Further, the ratio of the vertical direction / horizontal direction of 20% strength is 1.15, the tearing strength per 1 mm thickness in the vertical direction is 3.8 kgf / mm, and the elongation in the vertical direction is 5.0%. there were. The apparent shrinkage due to the treatment with the treatment liquid containing benzyl alcohol was 16% in the vertical direction, 11% in the horizontal direction, and 13.5% on average.

In addition, various characteristics of the artificial leather base material were measured as follows.

(Weight per unit (g / m ² ))
Measured according to JIS L1913 “Testing method for general short fiber nonwoven fabric”.

(Thickness (mm) and apparent density (g / cm ³ ))
The thickness was measured according to JIS L1913 “Test method for general short fiber nonwoven fabric”, and the apparent density was calculated from this value and the basis weight value.

(20% stronger)
In accordance with JIS L1096 8.12.1 “Tensile strength test”, a 2.5 cm × 16 cm test piece cut out from an artificial leather substrate was used and measured at a tensile speed of 100 mm / min. A stress-strain curve in each of the vertical and horizontal directions was obtained. Then, the stress at 20% elongation was read from the stress-strain curve, and the 20% strength was obtained.

(Tearing strength)
Using a 4 cm x 10 cm test piece cut out from the obtained artificial leather base material, the artificial leather base material was pulled according to JISL1096 8.15.1 A-1 method (single tongue) "tear strength test". The tear strength was determined by measuring the load when tearing at a speed of 100 mm / min. In addition, the test piece was created about each direction of the vertical direction which is an advancing direction in a manufacturing process, and a horizontal direction, and measured with them. The value obtained by dividing the maximum tear strength in the vertical direction by the thickness was taken as the tear strength per mm.

(Vertical extension rate)
In accordance with JIS L1096, a test piece having a longitudinal direction in the advancing direction (vertical direction) of the manufacturing process of the artificial leather base material is prepared, and a 1. The elongation at 8 kgf was measured with three samples. Then, the elongation when the average value thereof was 1.8 kgf at a tensile speed of 200 mm / min in the vertical direction was defined as the elongation rate (%).

(Apparent shrinkage)
A 300cm x 140cm test piece is cut out from the obtained artificial leather base material, and the center part is marked with 50cm x 50cm (vertical x horizontal), and the dimensional change in the vertical and horizontal directions before and after treatment with the treatment liquid is measured. did. And the average value of the shrinkage | contraction rate of a length direction and a horizontal direction was computed.

And the artificial leather with silver was manufactured by forming a silver surface resin layer on the artificial leather substrate (A) using the direct coating method. Specifically, by applying a polyurethane solution to the surface of the artificial leather substrate (A) using a reverse coater, the surface was flattened so that the water absorption time when dropping 3 cc of water drops was 3 minutes or more. A 14 μm-thick polyurethane layer was formed on the surface by applying a resin liquid for forming a skin layer containing a pigment and polyurethane. A top coat (lacquer) adjusted to 30 cp with Iwata Cup (IWATA NK-2 12s) is applied to the surface of the polyurethane layer, and a 5 μm-thick top coat is formed as part of the skin layer to add a silver finish. An artificial leather was obtained. And the obtained silver-tone artificial leather was evaluated as follows.

(Extension set rate)
A strip sample having a length of 20 cm and a width of 2.54 cm was prepared from the artificial leather with silver. Then, a marked line having a distance between marked lines of 10 cm was drawn at a position of 5 cm from each end in the length direction of the strip sample. And the strip sample was suspended so that the length direction might become a perpendicular direction, after applying the load of 8 kgf for 10 minutes, the load was removed and it was left to stand for 10 minutes. This operation is repeated 5 times, and the distance between marked lines (H1: cm) after applying the load for 10 minutes for the fifth time and the distance between marked lines (H2: cm) after removing the load and leaving for 10 minutes are measured. did. The vertical direction of the manufacturing process was the vertical direction, the horizontal direction was the vertical direction, and three strip samples in each direction were measured, and an average value of a total of six H1 and H2 was obtained. And the expansion | extension set rate was computed by the following formula using the average value of H1 and H2.
Elongation set rate (%) = [(H2-10) / (H1-10)] × 100

(Folded grain)
The obtained silver-tone artificial leather was cut to 20 × 20 cm to prepare a sample. And the external appearance was judged on the following references | standards, such as bending inside by making a center part a boundary.
A: Folding wrinkles with a feeling of solidity such as dense and fine creases and roundness occurred when folded. It was also excellent in drape.
B: Folding wrinkles were rough textures with large buckling and deep wrinkles, so that fine wrinkles could not be obtained and the texture was poor. Moreover, it was inferior to the drape property.
C: The sense of fulfillment was remarkably low.

(Rebound)
The obtained artificial leather was cut to 20 × 20 cm to prepare a sample. And after grasping by hand so that artificial leather might be rounded, the state when opening and releasing the hand was judged as follows.
A: The shape when rounded was retained like natural leather.
B: The rounded shape was retained for a while and then gradually recovered to the original shape.
C: The shape immediately after being rounded by the repulsive force recovered to the original shape.

The above evaluation results are shown in Table 1 below.

[Examples 2 to 9 and Comparative Examples 1 to 4]
In Example 1, the artificial leather substrate and silver were processed through the same steps as in Example 1 except that the concentration of benzyl alcohol in the treatment liquid and the temperature of the treatment liquid were changed as shown in Table 1. A toned artificial leather was obtained. And it evaluated similarly. The results are shown in Table 1.

[Examples 10 to 12]
25-island sea island type where 6-nylon and polyethylene are melted with a single screw extruder, island component is 6-nylon, sea component is high fluidity low density polyethylene, sea component / island component ratio = 50/50 The composite fiber was melt-spun with a composite spinning nozzle. And the sea-island type | mold composite fiber discharged from the composite spinning nozzle was sprayed on the collection net | network, extending | stretching with the air flow of 3500 m / min, and the long fiber web of the sea-island type | mold composite fiber was obtained. The basis weight of the obtained long fiber web was 36 g / m ² , and the fineness of the sea-island type composite fiber was 2 dtex. This continuous fiber web is continuously folded at a predetermined angle with a folding angle of 84 degrees with respect to the length direction of the web, thereby laminating 10 layers of web, a laminated web having a width of 210 cm and a basis weight of 360 g / m ² . Got. The obtained laminated web was subjected to a needle punch of 1400 punch / cm ² using a 1 barb felt needle, and further subjected to a hot press treatment through a heated roll, whereby a basis weight of 650 g / m ² , An entangled nonwoven fabric of sea-island composite fibers having a thickness of 1.53 mm was obtained.

Then, an entangled nonwoven fabric of sea-island type composite fibers was impregnated with an 18% DMF solution of polyester polyurethane, and then immersed in an aqueous DMF solution to solidify the polyurethane into a sponge. Then, the sea component polyethylene of the sea-island composite fiber was extracted and removed with toluene at 95 ° C., and then dried to obtain an intermediate body of an artificial leather base material including fiber entanglements of fiber bundles of ultrafine fibers. Furthermore, in order to improve the slipping property between the ultrafine fibers, the intermediate was provided so as to be 1.8% with respect to the artificial leather base material from which the lubricant (silicon oil-based aqueous dispersion) was obtained. . When the form angle of the laminated web immediately before the entanglement treatment was 45 degrees, the form angle immediately after application of the oil was 56 degrees. Next, heat treatment was performed which also served drying under conditions of 2% overfeed in the machine direction (MD), 3% widening in the transverse direction (TD), and an ambient temperature of 120 ° C. And the unprocessed artificial leather base material (b1) was obtained by carrying out the buffing process on both surfaces of the intermediate body using the 400th sandpaper, and smoothing the surface. The untreated artificial leather base material (b1) is composed of a fiber entanglement of 0.1 dtex ultrafine fibers and polyurethane impregnated with the fiber entanglement, an apparent density of 0.379 g / cm ³ , a basis weight of 553 g / m 2, It was an artificial leather substrate having a thickness of 1.46 mm.

Instead of the untreated artificial leather substrate (a1), the untreated artificial leather substrate (b1) was used, except that the concentration of benzyl alcohol in the treatment liquid and the temperature of the treatment liquid were treated as shown in Table 2. The subsequent steps were the same as in Example 1 to obtain an artificial leather base material and a silver-tone artificial leather. And it evaluated similarly. The results are shown in Table 2.

[Example 13]
6-nylon and polyethylene are each melted with a single screw extruder, and the island component is 6-nylon, the sea component is high-flowability low-density polyethylene, and the sea-island component ratio is 50/50. The composite fiber was melt-spun with a composite spinning nozzle. And the sea-island type | mold composite fiber discharged from the composite spinning nozzle was sprayed on the collection net | network, extending | stretching with the air flow of 3500 m / min, and the long fiber web of the sea-island type | mold composite fiber was obtained. The basis weight of the obtained long fiber web was 36 g / m ² , and the fineness of the sea-island type composite fiber was 2 dtex. This continuous fiber web is continuously folded at a predetermined angle with a folding angle of 84 degrees with respect to the length direction of the web, thereby laminating 10 layers of web, a laminated web having a width of 210 cm and a basis weight of 360 g / m ² . Got. The obtained laminated web was subjected to a needle punch of 1400 punch / cm ² using a 1 barb felt needle, and further subjected to a hot press treatment through a heated roll, whereby a basis weight of 650 g / m ² , An entangled nonwoven fabric of sea-island composite fibers having a thickness of 1.53 mm was obtained.

Then, an entangled nonwoven fabric of sea-island type composite fibers was impregnated with an 18% DMF solution of polyester polyurethane, and then immersed in an aqueous DMF solution to solidify the polyurethane into a sponge. Then, the sea component polyethylene of the sea-island composite fiber was extracted and removed with toluene at 95 ° C., and then dried to obtain an intermediate body of an artificial leather base material including fiber entanglements of fiber bundles of ultrafine fibers. Furthermore, in order to improve the slipping property between the ultrafine fibers, the intermediate was provided so as to be 1.8% with respect to the artificial leather base material from which the lubricant (silicon oil-based aqueous dispersion) was obtained. . When the form angle of the laminated web immediately before the entanglement treatment was 45 degrees, the form angle immediately after application of the oil was 56 degrees. Next, heat treatment was performed which also served drying under conditions of 2% overfeed in the machine direction (MD), 3% widening in the transverse direction (TD), and an ambient temperature of 120 ° C. And the unprocessed artificial leather base material (c1) was obtained by carrying out the buffing process on both surfaces of the intermediate body using the 400th sandpaper, and smoothing the surface. The untreated artificial leather substrate (c1) is composed of a fiber entanglement of 0.2 dtex ultrafine fibers and polyurethane impregnated with the fiber entanglement, with an apparent density of 0.36 g / cm ³ and a basis weight of 450 g / m ^2. And an artificial leather substrate having a thickness of 1.25 mm.

In place of the untreated artificial leather substrate (a1), the untreated artificial leather substrate (c1) was used, and the concentration of benzyl alcohol in the treatment liquid and the temperature of the treatment liquid were treated as shown in Table 3. The subsequent steps were the same as in Example 1 to obtain an artificial leather base material and a silver-tone artificial leather. And it evaluated similarly. The results are shown in Table 3.

The artificial leather of the present invention is used as a substitute for natural leather for shoes, clothing, gloves, bags, balls, interiors, vehicles, and the like.

Claims

Including a fiber entangled body of nylon ultrafine fibers of 1.5 dtex or less and a polymer elastic body impregnated in the fiber entangled body,
The apparent density is 0.3 to 0.55 g / m 3 ,
20% strong ratio of vertical / horizontal direction is 0.5-1.25,
An artificial leather base material having a tear strength per 1 mm thickness of 2.5 kgf / mm or more.
2. The artificial leather substrate according to claim 1, wherein in the vertical direction, the elongation rate is 1.8% or less at a tensile speed of 200 mm / min and 1.8 kgf.
The artificial leather base material according to claim 1 or 2, further comprising a silver surface resin layer formed by direct coating on at least one surface of the artificial leather base material according to claim 1 or 2.
A silver-tone artificial leather in which a silver surface resin layer is laminated on at least one surface of the artificial leather base material according to any one of claims 1 to 3.
The silver-finished artificial leather according to claim 4, wherein an elongation set rate specified as follows is 20 to 50%.
[Expansion set rate]
A strip sample having a length of 20 cm and a width of 2.54 cm is prepared. Then, a marked line with a distance between marked lines of 10 cm is drawn at a position of 5 cm from each end of the strip sample in the length direction. Then, the strip sample is hung so that the length direction becomes the vertical direction, a load of 8 kgf is applied for 10 minutes, and then the load is removed and left for 10 minutes. This operation is repeated 5 times, and the distance between marked lines (H1) after applying a load for 10 minutes for the fifth time and the distance between marked lines (H2) after leaving the load for 10 minutes are measured. The vertical direction of the manufacturing process is the vertical direction, and the vertical direction is the horizontal direction. Three strip samples in each direction are measured, and the average value of a total of six H1 and H2 is obtained. Then, using the average value of H1 and H2, the expansion set rate is calculated by the following formula.
Elongation set rate (%) = [(H2-10) / (H1-10)] × 100
Suede-like artificial leather obtained by raising at least one surface of the artificial leather substrate according to any one of claims 1 to 3.
An untreated artificial leather base material having an apparent density of 0.2 to 0.5 g / m 3 , comprising a fiber entanglement of nylon ultrafine fibers of 1.5 dtex or less and a polymer elastic body impregnated in the fiber entanglement The process of preparing
A step of immersing the untreated artificial leather base material in a treatment liquid containing benzyl alcohol to shrink the apparent shrinkage rate to 5 to 40%.
The step of shrinking so that the apparent shrinkage rate is 5 to 40% is a step of immersing the untreated artificial leather base material in a treatment solution containing 10 to 300 g / L of benzyl alcohol at 80 to 110 ° C. A method for producing an artificial leather substrate according to claim 7.
Preparing an artificial leather base material obtained by the method for producing an artificial leather base material according to claim 7 or 8,
Forming a silver resin layer on at least one surface of the artificial leather base material by a direct coating method.