KR102886636B1 - Artificial leather fabric, manufacturing method thereof, and ventilating seat, car using the same - Google Patents

Abstract

The present invention relates to artificial leather, a method for producing the same, and a ventilated seat and an automobile using the same, comprising: a nonwoven fabric; breathable holes penetrating the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric; and a nap formed on at least one surface of the nonwoven fabric; wherein the exposure ratio of the breathable holes according to mathematical formula 1 is 0.1% or more and 40% or less, and the average length of the nap covering the breathable holes when viewed from the surface of the nonwoven fabric on which the nap is formed is 100 ㎛ or more and 400 ㎛ or less.

Description

Artificial leather, manufacturing method thereof, and ventilating seat, car using the same {ARTIFICIAL LEATHER FABRIC, MANUFACTURING METHOD THEREOF, AND VENTILATING SEAT, CAR USING THE SAME}

The present invention relates to artificial leather and a method for manufacturing the same, a ventilated seat using the same, and an automobile.

Artificial leather used as a material for vehicles has a soft texture and unique appearance similar to natural leather, so there is a growing trend to replace existing fabric, knitwear, and leather materials with artificial leather as the surface material for interior materials such as vehicle seats.

Recently, luxury and mid-size cars are equipped with ventilated seats, and these are often made of natural leather or polyurethane (PU) faux leather. As the amount of time spent in cars increases, consumer demand for highly ventilated seats is also growing, necessitating the development of more affordable punched faux leather products.

Recently, artificial leather made of polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU) has been replacing natural leather and polyurethane (PU) artificial leather due to its low price. However, there are technical issues in the specifications of punching products for main parts, cushions, and backs, excluding the side parts, so their application in related products is limited.

Accordingly, a technology has been developed to provide ventilation performance by preforating artificial leather products in the final stage using a recently commercialized artificial leather manufacturing technology for automobile seats and creating punching holes for ventilation purposes. However, this method has limitations in terms of appearance and durability, as the holes are exposed on the surface of the product, which hinders the unique appearance characteristics of suede, and foreign substances or fluff are generated between the holes.

Therefore, there is an urgent need to develop new artificial leather fabrics useful for manufacturing ventilated seat products.

The present invention relates to providing artificial leather that can exhibit excellent breathability and appearance characteristics even when used for a long period of time.

In addition, the present invention provides a method for manufacturing the above artificial leather, and a ventilated seat and an automobile using the same.

In order to solve the above problem, the present specification provides an artificial leather comprising: a nonwoven fabric; breathable holes penetrating the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric; and a nap formed on at least one surface of the nonwoven fabric; wherein the exposure ratio of the breathable holes according to the following mathematical formula 1 is 0.1% or more and 40% or less, and when viewed from the surface of the nonwoven fabric on which the nap is formed, the average length of the nap covering the breathable holes is 100 ㎛ or more and 400 ㎛ or less.

[Mathematical Formula 1]

The exposure ratio of the breathable hole = (maximum diameter of the breathable hole covered by the nap when viewed from the surface of the nonwoven fabric on which the nap is formed / maximum diameter of the breathable hole) * 100 is provided.

The present specification also provides a method for manufacturing artificial leather, comprising: a step of forming breathable holes penetrating the interior of a nonwoven fabric from one surface of the nonwoven fabric to an opposite surface of the nonwoven fabric; and a step of forming a nap on the surface of the nonwoven fabric on which the breathable holes are formed.

The present specification also provides a ventilated sheet including the artificial leather.

The present specification also provides a vehicle including the ventilation seat.

Unless explicitly stated otherwise in this specification, terminology is used only to describe specific embodiments and is not intended to limit the invention.

As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise.

As used herein, the term “including” means specifying a particular characteristic, region, integer, step, operation, element and/or component, but does not exclude the presence or addition of other particular characteristics, regions, integers, steps, operations, elements, components and/or groups.

In addition, terms including ordinal numbers, such as "first" and "second," in this specification are used to distinguish one component from another and are not limited by the ordinal numbers. For example, within the scope of the present invention, the first component may also be referred to as the second component, and similarly, the second component may be referred to as the first component.

Hereinafter, artificial leather, a method for manufacturing the same, and a ventilated seat and automobile using the same according to specific embodiments of the invention will be described in more detail.

1. Artificial leather

According to one embodiment of the invention, an artificial leather may be provided, comprising: a nonwoven fabric; breathable holes penetrating the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric; and a nap formed on at least one surface of the nonwoven fabric; wherein the exposure ratio of the breathable holes according to the following mathematical formula 1 is 0.1% or more and 40% or less, and when viewed from the surface of the nonwoven fabric on which the nap is formed, the average length of the nap covering the breathable holes is 100 ㎛ or more and 400 ㎛ or less.

[Mathematical Formula 1]

Exposure ratio of breathable holes = (maximum diameter of breathable holes covered by the nap when viewed from the surface of the nonwoven fabric on which the nap is formed / maximum diameter of the breathable holes when viewed from the surface of the nonwoven fabric) * 100.

The inventors of the present invention have experimentally confirmed that the artificial leather of the above embodiment is manufactured by pre-treating a non-woven fabric to perforate holes in the cross-section, then grinding the surface with sandpaper to form a raised layer, and then performing dyeing/post-processing to conceal the breathable holes in the inner cross-section with the raised layer on the surface, thereby manufacturing an artificial leather having the appearance unique to suede in which the breathable holes inside are not exposed to the surface, thereby maintaining the unique appearance of suede and suppressing clogging of the breathable holes by foreign substances/dust or lint, thereby maintaining the appearance for a long period of time, and have completed the invention.

In particular, by pre-treating a non-woven fabric by perforating to provide breathable holes in the cross-section and then grinding the surface with sandpaper to form a raised layer, the final artificial leather is manufactured so that the exposure ratio of breathable holes according to the above mathematical formula 1 is 0.1% or more and 40% or less, and when viewed from the surface of the non-woven fabric on which the raised layer is formed, the average length of the raised layer covering the breathable holes is 100 ㎛ or more and 400 ㎛ or less, thereby achieving excellent appearance characteristics while suppressing clogging of breathable holes by foreign substances/dust or fluff due to the raised layer having an appropriate length, and at the same time, by controlling the exposure ratio of breathable holes according to the mathematical formula 1 to 0.1% or more and 40% or less, it is possible to implement a breathable performance at an appropriate level for application to automobile ventilated seats.

In the past, when manufacturing artificial leather, the surface of nonwoven fabric was ground with sandpaper to form a raised layer, and after dyeing/post-processing, a perforation post-processing was performed to provide breathable holes in the cross-section. As the breathable holes were drilled, the raised hairs on the breathable holes were cut, and when viewed from the surface of the nonwoven fabric where the raised hairs were formed, the average length of the raised hairs covering the breathable holes became shorter than 100 ㎛, which caused blockage of the breathable holes by foreign matter/dust or fluff, making it difficult to maintain the appearance for a long time.

On the other hand, the artificial leather of the above embodiment is obtained by a method for manufacturing artificial leather described below, in which a nonwoven fabric is pre-treated with perforation to provide breathable holes in the cross-section, the surface is ground with sandpaper to form a raised layer, and then dyeing/post-processing is performed, thereby satisfying the exposure ratio of breathable holes and the average length of the raised layer covering the breathable holes according to the characteristic mathematical formula 1, thereby solving the problems of conventional artificial leather.

Specifically, the artificial leather may have an exposure ratio of breathable holes of 0.1% or more and 40% or less, or 1% or more and 40% or less, or 3% or more and 40% or less, or 3.2% or more and 38.3% or less, or 0.1% or more and 10% or less, as determined by the following mathematical formula 1.

[Mathematical Formula 1]

Exposure ratio of breathable holes = (maximum diameter of breathable holes covered by the nap when viewed from the surface of the nonwoven fabric on which the nap is formed / maximum diameter of breathable holes when viewed from the surface of the nonwoven fabric) * 100.

In the above mathematical expression 1, when viewed from the surface of the nonwoven fabric on which the nap is formed, the maximum diameter of the breathable hole covered by the nap refers to the maximum diameter of the breathable hole covered by the nap when viewed from the direction perpendicular to the surface of the nonwoven fabric on which the nap is formed.

The above maximum diameter means the maximum distance between two points where a straight line passing through the center of gravity intersects the boundary line.

In the above artificial leather, since the nap has a certain length, part or all of the lower ventilation holes may be covered by the nap. Accordingly, for a nonwoven fabric in which ventilation holes and nap are formed together on the surface of the artificial leather, when viewed from the outside while maintaining a straight line in a direction perpendicular to the nonwoven fabric surface in the order of the nap and the ventilation holes, the maximum diameter of the ventilation holes covered by the nap may be reduced compared to the maximum diameter of the actual ventilation holes.

In the above mathematical expression 1, when viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole refers to the maximum diameter of the breathable hole when viewed from the surface of the nonwoven fabric when there is no nap or when the nap is removed, i.e., the maximum diameter of the actual breathable hole. Alternatively, in the above mathematical expression 1, when viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole may refer to the maximum diameter of the perforation pin used to form the breathable hole.

When looking at the surface of the nonwoven fabric on which the above-mentioned pile is formed, examples of a method for measuring the maximum diameter of the breathable hole covered by the pile are not particularly limited, but for example, the surface can be magnified 50 times using an optical microscope and the appearance of the perforated area and the non-perforated area can be compared and measured. In addition, examples of a method for measuring the maximum diameter of the above-mentioned breathable hole are not particularly limited, but for example, the maximum diameter of the perforation pin used to form the breathable hole can be measured.

At this time, the ratio of the maximum diameter of the ventilation hole covered by the reduced nap to the maximum diameter of the actual ventilation hole is the exposure ratio of the ventilation hole of the above mathematical formula 1, and the smaller the exposure ratio of the ventilation hole of the above mathematical formula 1, the more the ventilation hole is covered by the nap, and the larger the exposure ratio of the ventilation hole of the above mathematical formula 1, the less the ventilation hole is covered by the nap.

If the exposure ratio of the ventilation holes according to the above mathematical formula 1 is excessively reduced, the surface pile density on the ventilation holes increases, which may make it difficult to apply the sheet as a ventilation sheet as the ventilation performance due to the ventilation holes is reduced.

On the other hand, if the exposure ratio of the ventilation holes according to the above mathematical formula 1 increases excessively, the ventilation holes are excessively exposed to the outside, which deteriorates the unique appearance characteristics of suede, and foreign substances may get caught between the ventilation holes or fluff may be generated, which may cause problems in terms of appearance and durability. In addition, the mechanical properties of the artificial leather, such as tensile strength and tear strength, may decrease.

In addition, when viewed from the surface of the nonwoven fabric on which the nap is formed, the average length of the nap covering the ventilation hole may be 100 ㎛ or more and 400 ㎛ or less, or 110 ㎛ or more and 380 ㎛ or less, or 118 ㎛ or more and 370 ㎛ or less, or 150 ㎛ or more and 250 ㎛ or less.

When viewed from the surface of the nonwoven fabric on which the above-mentioned nap is formed, the average length of nap covering the ventilation holes refers to the arithmetic mean of the lengths of nap covering the ventilation holes when viewed from a direction perpendicular to the surface of the nonwoven fabric on which the above-mentioned nap is formed. The nap covering the ventilation holes refers to any nap covering even a very small portion of the ventilation holes, and the length of such nap refers to the entire length of the nap starting from the surface of the nonwoven fabric.

In the artificial leather, since the nap has the above-described predetermined length, part or all of the lower ventilation holes may be covered by the nap. Accordingly, for a nonwoven fabric having ventilation holes and nap formed together on the surface of the artificial leather, when viewed from the outside while maintaining a straight line in a direction perpendicular to the nonwoven fabric surface in the order of the nap and the ventilation holes, the maximum diameter of the ventilation holes covered by the nap may be reduced compared to the maximum diameter of the actual ventilation holes.

When looking at the surface of the nonwoven fabric on which the above-mentioned nap is formed, there are no particular limitations to the method for measuring the average length of nap covering the ventilation holes. For example, the method may be performed by comparing the appearance of the perforated area and the non-perforated area by magnifying the surface by 100 times using an optical microscope.

At this time, when viewed from the surface of the nonwoven fabric on which the nap is formed, the larger the average length of the nap covering the ventilation holes, the more ventilation holes can be covered by the nap, and when viewed from the surface of the nonwoven fabric on which the nap is formed, the smaller the average length of the nap covering the ventilation holes, the less ventilation holes can be covered by the nap.

When viewed from the surface of the nonwoven fabric on which the above-mentioned nap is formed, if the average length of the nap covering the ventilation holes increases excessively, the density of the nap on the surface of the ventilation holes increases, which reduces the ventilation performance of the ventilation holes, making it difficult to apply the nonwoven fabric to a ventilated sheet.

On the other hand, when looking at the surface of the nonwoven fabric on which the nap is formed, if the average length of the nap covering the ventilation holes is excessively reduced, the ventilation holes will be excessively exposed to the outside, which will hinder the unique appearance characteristics of suede, and foreign substances may get caught between the ventilation holes or fluff may be generated, which may cause problems in terms of appearance and durability. In addition, the mechanical properties of the artificial leather, such as tensile strength and tear strength, may decrease.

Meanwhile, the breathability of the artificial leather according to the Hyundai Motor Company technical standard (MS300-32, Article 4.18, Breathability Evaluation Criteria) may be 2.5 ml/cm ² ·sec or more and 7.0 ml/cm ² ·sec or less, or 2.8 ml/cm ² ·sec or more and 7.0 ml/cm ² ·sec or less, or 2.8 ml/cm ² ·sec or more and 6.4 ml/cm ² ·sec or less, or 2.8 ml/cm ^{2 ·} sec or more and 6.4 ml/cm ² ·sec or less, or 5 ml/cm ² ·sec or more and 7.0 ml/cm ² ·sec or less.

As described above, the artificial leather can exhibit breathability when exposed to external air, as the exposure ratio of breathable holes according to the following mathematical formula 1 is 0.1% or more and 40% or less.

If the breathability of the artificial leather mentioned above is excessively reduced based on the Hyundai Motor Company technical standards (MS300-32, Article 4.18 Breathability Evaluation Criteria), it may be difficult to apply it to ventilated seats as the breathability performance due to the ventilation holes is reduced.

On the other hand, if the breathability of the artificial leather is excessively increased based on the Hyundai Motor Company technical standards (MS300-32, Article 4.18, Breathability Evaluation Criteria), the breathable holes will be excessively exposed to the outside, which will hinder the unique appearance characteristics of suede, and foreign substances or fluff may get caught between the breathable holes, which may cause problems in terms of appearance and durability. In addition, the mechanical properties of the artificial leather, such as tensile strength and tear strength, may decrease.

Meanwhile, the tensile strength of the artificial leather according to the Hyundai Motor Company technical standard (MS320-19, Type A-2, Article 4.3 Tensile strength evaluation criteria) may be 9 kgf/cm or more and 20 kgf/cm or less, or 9 kgf/cm or more and 15 kgf/cm or less, or 9 kgf/cm or more and 13 kgf/cm or less.

In addition, the tear strength of the artificial leather according to the Hyundai Motor Company technical standard (MS320-19, Type A-2, Clause 4.5 tear strength evaluation standard) may be 2.2 kgf or more and 5.0 kgf or less, or 2.5 kgf or more and 5.0 kgf or less, or 2.2 kgf or more and 3.0 kgf or less, or 2.5 kgf or more and 3.0 kgf or less.

Meanwhile, the artificial leather may include a nonwoven fabric. The description of the nonwoven fabric can be applied without limitation to various nonwoven fabrics widely used in the existing artificial leather field. However, as an example, the nonwoven fabric may be formed by needle-punching a sea-island ultrafine composite yarn containing polyester as a sea component and polyester-based dope yarn as a sea component, and then dissolving the sea component.

The main component of the nonwoven fabric is made of polyester dope-dyed yarn, and such polyester dope-dyed yarn can have a single yarn fineness ranging from 0.04 to 0.3 denier. If the lower limit of the dope fineness is 0.04 denier or lower, problems such as reduced dyeability and reduced light fastness may occur. In other words, if the thickness of the fiber included in the dope component becomes too thin, the amount of dye used increases to express the target color, and if the amount of dye used increases, the light fastness decreases.

Conversely, if the upper limit of the fiber fineness of the dope component exceeds 0.3 denier, the fibers become thicker and stiffer, which reduces the feel of the artificial leather. Therefore, it is desirable to adjust the single-filament fineness of the polyester dope-dyed yarn, taking into account the desired light fastness characteristics and the feel of the artificial leather.

The above nonwoven fabric may include a fiber count per unit filament in the range of 7 to 36. The number of fibers per unit filament in the nonwoven fabric is related to the single yarn fineness of the polyester dope-dyed yarn described above. That is, when the single yarn fineness of the polyester dope-dyed yarn described above is low, the number of fibers per unit filament in the dope-dyed yarn will be high, and when the single yarn fineness of the polyester dope-dyed yarn is high, the number of fibers per unit filament in the dope-dyed yarn will be low.

The nonwoven fabric includes a fabric formed by dyeing and reducing cleaning a nonwoven fabric from which a marine component has been dissolved, and then subjecting the washed nonwoven fabric layer to a flame-retardant treatment in a bath. In other words, the nonwoven fabric of the artificial leather according to the disclosed invention is subjected to a flame-retardant treatment in a bath after dyeing and reducing cleaning, thereby enabling better absorption of the flame retardant into the nonwoven fabric, thereby providing an artificial leather for vehicle interior materials with excellent flame retardancy.

The above artificial leather may further include an elastic resin layer coated on the nonwoven fabric. The elastic resin layer is formed to impart elastic properties to the artificial leather, and by imparting the inherent elasticity of the polyurethane material, it can suppress the occurrence of wrinkles during sewing and covering.

The elastic resin layer can be formed by wet impregnating a nonwoven fabric with an elastic resin, such as a polyurethane resin. Specifically, a nonwoven fabric impregnated with a polyurethane elastomer can be manufactured by immersing the nonwoven fabric in an impregnation solution containing polyurethane.

More specifically, the polyurethane resin may be a material used in the production of wet polyurethane, and for example, polyester-based polyurethane or copolymer type may be preferably applied. In addition, the polyurethane resin may be contained in the range of 27.5 to 31 wt% with respect to the total weight of the artificial leather. If the proportion of polyurethane, which is a high molecular elastomer, in the total weight of the artificial leather is less than 27.5 wt%, the elasticity of the artificial leather deteriorates, so that the feel of fabric increases rather than the feel of leather, and if it is more than 31 wt%, the filling ratio increases, so that the emotional quality becomes hard and a problem may occur that it feels like paper. Emotional quality is one of the quality standards for automobiles, and it refers to the quality of the sight and touch that a person feels sensually, and the feeling of luxury or goodness when seeing and touching, and is a quality related to the appearance quality and surface feel (cushioning and/or softness, etc.).

If necessary, the nonwoven fabric layer may contain 1.5 to 3 wt% of the carbon black relative to the total weight of the leather component. If the concentration of carbon black is less than 1.5 wt%, the blackness of the preliminary artificial leather before dyeing becomes weak, and thus a large amount of dye is required to realize the target high-concentration black color. Since these dyes have weaker light fastness than carbon black, most of the dyes are destroyed in the process of evaluating the light fastness of the artificial leather, and as a result, the light fastness of the artificial leather may decrease as the black color is realized with a small amount of carbon black.

Conversely, if the carbon black concentration exceeds 3 wt%, the apparent concentration reaches saturation, making it difficult to visually detect the increase in the apparent concentration even if the carbon black concentration increases. Therefore, it is desirable to appropriately adjust the carbon black content considering the desired blackness and light fastness levels.

Meanwhile, the artificial leather may include breathable holes penetrating the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric. The breathable holes may be formed by a punching process generally used in the production of breathable sheets made of natural leather or PU artificial leather, thereby ensuring breathable performance of the breathable sheet.

The above-mentioned breathable holes can penetrate the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric facing thereto. The breathable holes on one surface of the nonwoven fabric and the breathable holes on the opposite surface of the nonwoven fabric facing thereto can penetrate the inside of the nonwoven fabric and be connected to each other, and more preferably, they can penetrate the inside of the nonwoven fabric in a straight line parallel to the thickness direction of the nonwoven fabric. That is, the breathable holes on one surface of the nonwoven fabric and the breathable holes on the opposite surface of the nonwoven fabric can face each other and penetrate the inside of the nonwoven fabric parallel to the thickness direction of the nonwoven fabric and be connected to each other.

When viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole may be 0.1 mm or more and 2.0 mm or less, or 0.3 mm or more and 1.5 mm or less, or 0.5 mm or more and 1.0 mm or less. When viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole refers to the maximum diameter of the breathable hole when viewed from the surface of the nonwoven fabric when there is no napping or when the napping is removed, that is, the maximum diameter of the actual breathable hole. Alternatively, when viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole may refer to the maximum diameter of a perforation pin used to form the breathable hole. The maximum diameter refers to the maximum value of the distance between two points where a straight line passing through the center of gravity intersects a boundary line.

When viewed from the surface of the above nonwoven fabric, if the maximum diameter of the above breathable holes is excessively reduced, the breathable performance due to the breathable holes may be reduced, making it difficult to apply the nonwoven fabric to a breathable sheet.

Conversely, when viewed from the surface of the nonwoven fabric, if the maximum diameter of the ventilation holes is excessively increased, the ventilation holes are excessively exposed to the outside, which deteriorates the unique appearance characteristics of suede, and foreign substances may get caught between the ventilation holes or fluff may be generated, which may cause problems in terms of appearance and durability. In addition, the mechanical properties of the artificial leather, such as tensile strength and tear strength, may decrease.

The above-mentioned ventilation holes may be two or more, and the spacing between adjacent ventilation holes may be 1 mm or more and 8 mm or less, or 3 mm or more and 5 mm or less. The spacing between adjacent ventilation holes refers to the shortest straight-line distance between adjacent ventilation holes when viewed from the surface of the nonwoven fabric. If the spacing between adjacent ventilation holes increases excessively, the number of ventilation holes per unit area decreases, resulting in a decrease in the ventilation performance by the ventilation holes, making it difficult to apply the product to a ventilated sheet.

Conversely, when viewed from the surface of the nonwoven fabric, if the spacing between adjacent breathable holes is excessively reduced, the number of breathable holes per unit area increases, which may cause a problem in that mechanical properties of the artificial leather, such as tensile strength and tear strength, decrease.

Meanwhile, the artificial leather may include a nap formed on at least one surface of the nonwoven fabric. The nap may be formed on one side of the nonwoven fabric, or on both sides, including the one side and the opposite side. The nap may be formed as a result of buffing the surface of the nonwoven fabric.

In particular, the artificial leather is formed by pre-treating a nonwoven fabric to perforate a cross-section to provide breathable holes, and then grinding the surface with sandpaper to form a raised layer, so that the suede's unique surface raised texture remains around the area where the breathable holes are created, thereby maintaining the suede's unique exterior appearance and concealing the breathable holes inside the nonwoven fabric without exposing them to the outside.

2. Method for manufacturing artificial leather

According to another embodiment of the invention, a method for manufacturing artificial leather may be provided, comprising: a step of forming breathable holes penetrating the interior of a nonwoven fabric from one surface of the nonwoven fabric to an opposite surface of the nonwoven fabric; and a step of forming a nap on the surface of the nonwoven fabric on which the breathable holes are formed. The contents of the nonwoven fabric, the breathable holes, the nap, and the artificial leather include all of the contents described above in the above embodiment.

That is, the artificial leather of the above embodiment can be obtained by the method for manufacturing the artificial leather of the other embodiment. In addition, the method for manufacturing the artificial leather of the other embodiment can be the method for manufacturing the artificial leather of the above embodiment.

In the past, when manufacturing artificial leather, the surface of nonwoven fabric was ground with sandpaper to form a raised layer, and after dyeing/post-processing, a perforation post-processing was performed to provide breathable holes in the cross-section. As the breathable holes were drilled, the raised hairs on the breathable holes were cut, and when viewed from the surface of the nonwoven fabric where the raised hairs were formed, the average length of the raised hairs covering the breathable holes became shorter than 100 ㎛, which caused blockage of the breathable holes by foreign matter/dust or fluff, making it difficult to maintain the appearance for a long time.

On the other hand, the artificial leather manufacturing method of the other embodiment described above solves the problems of conventional artificial leather by pre-treating a non-woven fabric by perforating to provide breathable holes in the cross-section and then grinding the surface with sandpaper to form a napped layer, thereby satisfying the exposure ratio of breathable holes and the average length of nap covering the breathable holes according to the characteristic mathematical formula 1 as in the artificial leather of the above-described embodiment described above.

Specifically, the method for manufacturing artificial leather of the other embodiment may include a step of forming breathable holes penetrating the interior of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric.

In the step of forming breathable holes penetrating the interior of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric, examples of the method for manufacturing the nonwoven fabric are not particularly limited, and existing nonwoven fabric manufacturing processes can be applied without limitation. However, as an example, a nonwoven fabric can be manufactured through a step of forming a nonwoven fabric by needle-punching a sea-island ultra-fine composite yarn.

The step of forming a nonwoven fabric by needle-punching the above-mentioned ultra-fine composite yarn includes forming a nonwoven fabric by needle-punching the ultra-fine composite yarn of the sea-island type having a readily soluble polyester as a sea component and a polyester-based dope-dyed yarn as a core component. More specifically, a multi-layer web can be formed using the ultra-fine composite yarn of the sea-island type through a carding process and a cross-lapping process, and then the web can be needle-punched to form a nonwoven fabric.

The above-mentioned sea component may be contained in an amount of 10 wt% to 50 wt%, or 10 wt% to 40 wt%, and the above-mentioned island component may be contained in an amount of 50 wt% to 90 wt%, or 60 wt% to 90 wt%.

In the step of forming breathable holes penetrating the interior of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric, the nonwoven fabric may be punched. The punching may be performed according to a punching process generally used in the manufacture of breathable sheets made of natural leather or PU artificial leather.

For example, when punching the above non-woven fabric, pin punching may be used, and at this time, the maximum diameter of the pin may be 0.1 mm or more and 2.0 mm or less, or 0.3 mm or more and 1.5 mm or less, or 0.5 mm or more and 1.0 mm or less. The maximum diameter refers to the maximum value of the distance between two points where a straight line passing through the center of gravity intersects the boundary line.

When viewed from the surface of the above nonwoven fabric, if the maximum diameter of the pin is excessively reduced, the breathability due to the breathable holes may be reduced, making it difficult to apply it as a ventilated sheet.

Conversely, if the maximum diameter of the above pins increases excessively, the ventilation holes will be excessively exposed to the outside, which will compromise the unique appearance characteristics of suede. Furthermore, foreign matter or fluff may become trapped between the ventilation holes, resulting in poor aesthetics and durability. Furthermore, mechanical properties of the artificial leather, such as tensile strength and tear strength, may decrease.

The above pins may be two or more, and the spacing between adjacent pins may be 1 mm or more and 8 mm or less, or 3 mm or more and 5 mm or less. The spacing between adjacent pins refers to the shortest straight-line distance between adjacent pins. If the spacing between adjacent pins increases excessively, the number of ventilation holes per unit area decreases, which may result in a decrease in ventilation performance by the ventilation holes, making it difficult to apply the sheet as a ventilation sheet.

Conversely, when viewed from the surface of the nonwoven fabric, if the spacing between adjacent pins is excessively reduced, the number of breathable holes per unit area increases, which may cause a problem in that the mechanical properties of the artificial leather, such as tensile strength and tear strength, decrease.

When viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole may be 0.1 mm or more and 2.0 mm or less, or 0.3 mm or more and 1.5 mm or less, or 0.5 mm or more and 1.0 mm or less. There may be two or more breathable holes, and the interval between adjacent breathable holes may be 1 mm or more and 8 mm or less, or 3 mm or more and 5 mm or less. The description of the breathable hole is as described above in the above embodiment.

Before the step of forming breathable holes penetrating the interior of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric, the step of impregnating the nonwoven fabric with an elastic resin may be further included.

Specifically, a nonwoven fabric impregnated with a polyurethane elastomer can be manufactured by immersing the nonwoven fabric in an impregnation solution containing polyurethane. Depending on the embodiment, the impregnation solution may additionally contain carbon black, a surfactant, and a solvent (dimethylformamide) in addition to the polyurethane component.

The step of impregnating the nonwoven fabric with a polyurethane resin may include impregnating the nonwoven fabric with the polyurethane resin so that the polyurethane resin is included in a range of 27.5 wt% to 31 wt% based on the total weight of the artificial leather.

Meanwhile, prior to the step of forming a nap on the surface of the nonwoven fabric having the above-described breathable holes, a step of dissolving the marine component of the nonwoven fabric may be performed. The step of dissolving the marine component of the nonwoven fabric includes treating the nonwoven fabric previously impregnated with the polyurethane resin with an alkaline aqueous solution to dissolve the marine component. Since the disclosed invention has a readily soluble polyester as the marine component, the marine component can be easily dissolved by the alkaline aqueous solution.

Meanwhile, the method for manufacturing artificial leather according to another embodiment may include a step of forming a nap on the surface of the nonwoven fabric having the breathable holes formed therein. The step of forming a nap on the surface of the nonwoven fabric having the breathable holes formed therein must be sequentially performed after first performing the step of forming breathable holes penetrating the interior of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric, as described above.

In the step of forming a nap on the surface of the nonwoven fabric in which the above-mentioned breathable holes are formed, the surface of the nonwoven fabric may be ground with sandpaper of Mesh #80 or higher and #240 or lower. If the mesh of the sandpaper is lower than #80, the grounding may be rough and the breathable holes may be blocked, and if the mesh of the sandpaper is higher than #240, the nap may be shortened and the breathable holes may be excessively exposed.

Meanwhile, after the step of forming a nap on the surface of the nonwoven fabric in which the above-mentioned ventilation holes are formed, a step of dyeing and reducing and washing the nonwoven fabric from which the seaweed component has been dissolved and a step of subjecting the washed nonwoven fabric to a flame-retardant treatment in a bath may be further performed.

Anthraquinone dyes can be used as the above dye type, but the types of dyes that can be used are not limited to this. After dyeing is complete, the remaining dye is drained from the dyeing machine, water is supplied to the machine again, and then it is rinsed for reduction. This rinse process can be repeated several times as needed.

The above flame retardant processing may include a process of absorbing a phosphoric acid ester flame retardant in an amount of 15 to 30 wt% based on the total weight of the artificial leather at a bath ratio of 1:5 to 1:30 after the dyeing and reduction washing steps. Meanwhile, depending on the embodiment, an additive such as a nonionic fatty acid ester dispersant may be additionally added together with the flame retardant in the flame retardant processing.

3. Ventilated seats, cars

According to another embodiment of the invention, a ventilation sheet comprising the artificial leather of the above embodiment may be provided. The contents of the artificial leather include all of the contents described above in the above embodiment.

In addition, according to another embodiment of the invention, a vehicle may be provided that includes a ventilated seat according to the other embodiment. The contents of the ventilated seat include all of the contents described above in the other embodiment.

That is, the artificial leather of the above embodiment can be used for automobile ventilation seats.

The specific details of the above ventilation seat or automobile are not particularly limited, and various conventionally known technical configurations can be applied without limitation.

According to the present invention, artificial leather capable of implementing excellent breathability and appearance characteristics even when used for a long period of time, a method for manufacturing the same, and a ventilated seat and automobile using the same can be provided.

The invention is described in more detail in the following examples. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited by the following examples.

<Examples and Comparative Examples: Manufacturing of Artificial Leather>

Example 1

1) Manufacturing of nonwoven fabrics

Polyethylene terephthalate was prepared as the island component and alkali-soluble co-polyester was prepared as the sea component, and 70 wt% of the island component and 30 wt% of the sea component were fed into an extruder and melt-extruded. When the island component was melted and extruded, it was discharged through a spinning nozzle to produce a sea-island filament with 16 split fibers per filament. Subsequently, the filament was drawn so that the island component had a fineness of 0.15 denier, and crimped so that the number of crimps was 10/inch, heat-set, and then cut to 51 mm to produce a sea-island ultra-fine composite yarn.

The above-mentioned ultra-fine composite yarn was formed into a multi-layer web through a carding process and a cross-lapping process. Next, needle punching was performed on the multi-layer web, and steam was used to treat it at 100°C and a relative humidity of 90% or more for 5 minutes, thereby producing a nonwoven fabric having an apparent density of 0.3 g/cm ³ .

2) Manufacturing of nonwoven fabric impregnated with elastic material

A nonwoven fabric was immersed in an impregnation solution containing polyurethane, the polyurethane was coagulated in an aqueous dimethylformamide solution, and washed with water to produce a nonwoven fabric in which 30 wt% of the polyurethane elastomer was impregnated into the nonwoven fabric.

3) Manufacturing of perforated pre-treated nonwoven fabric

The above polyurethane-impregnated nonwoven fabric was pin-punched using a perforated pin to a range of breathable hole diameters of 0.7 mm and breathable hole spacing of 4.0 mm.

4) Manufacturing of artificial leather

Afterwards, the perforated pre-treated polyurethane-impregnated nonwoven fabric was immersed in a 3 wt% NaOH aqueous solution, and then the seaweed component was eluted using a steamer at a temperature of 70°C to form a nonwoven fabric of polyethylene terephthalate fibers having 16 split fibers per filament and a single yarn fineness of 0.15 denier, thereby producing an eluted fabric. The surface of the eluted fabric was ground using mesh #150 sandpaper to form a nap, and then dyed under the dyeing conditions below.

The dye was a mixed dye of 0.8 wt% anthraquinone black disperse dye, 0.5 wt% anthraquinone red disperse dye, 1.5 wt% anthraquinone blue disperse dye, and 0.5 wt% anthraquinone yellow disperse dye based on the total fiber weight. In addition, 4.0 wt% of a triazine derivative based on the total fiber weight was used as a UV absorber, 1 g/L of a nonionic fatty acid ester was used as a dispersant, 1 g/L of acetic acid was used as an acid, and the bath ratio was adjusted to 1:20. After completing dyeing under the above conditions, the dye residue was discharged from the dyeing machine, water was supplied to the dyeing machine again, and then reduction washing was performed under reduction washing conditions (sodium hyposulfite 8 g/L, sodium hydroxide 4 g/L, bath ratio 1:20) at 80 ℃ for 20 minutes.

After reduction washing, the dyeing machine was supplied with water, and the process of washing away the remaining dye decomposition products and alkali was repeated four times, and then flame-retardant treatment in a bath was performed. The flame-retardant treatment in a bath was performed using 25.0 wt% of a phosphate ester flame retardant based on the total fiber weight, 1 g/L of a nonionic fatty acid ester as a dispersant, and the bath ratio was adjusted to 1:20. In addition, the flame-retardant treatment in a bath was performed at a treatment temperature of 80°C for 30 minutes. After the flame-retardant treatment in a bath was completed, the remaining liquid was discharged, and water was supplied to the dyeing machine to remove the insufficient flame retardant and dispersant, rinsed, and dried to produce artificial leather.

Example 2

Artificial leather was manufactured using the same method as Example 1, except that the diameter of the ventilation hole was changed to 0.3 mm during the pin punching.

Example 3

Artificial leather was manufactured using the same method as Example 1, except that the diameter of the ventilation hole was changed to 1.5 mm during the pin punching.

Example 4

Artificial leather was manufactured using the same method as Example 1, except that the ventilation hole spacing was changed to 1.0 mm during the pin punching.

Example 5

Artificial leather was manufactured using the same method as Example 1, except that the ventilation hole spacing was changed to 8.0 mm during the pin punching.

Comparative Example 1

1) Manufacturing of nonwoven fabrics

The process was carried out in the same manner as the manufacturing step of the nonwoven fabric in Example 1 above.

2) Manufacturing of nonwoven fabric impregnated with elastic material

The same method as the manufacturing step of the nonwoven fabric impregnated with elastic material in Example 1 above was used.

3) Manufacturing of artificial leather

Except that the unperforated polyurethane-impregnated nonwoven fabric obtained in the manufacturing step of the elastic body-impregnated nonwoven fabric of Comparative Example 1 2) was used instead of the perforated pre-treated polyurethane-impregnated nonwoven fabric, the same method as the manufacturing step of artificial leather of Example 1 3) was carried out.

4) Manufacturing of artificial leather with perforation post-treatment

In the manufacturing step of artificial leather 3) of Comparative Example 1 above, artificial leather was manufactured by pin punching the artificial leather with a breathable hole diameter of 0.7 mm and a breathable hole spacing of 4.0 mm.

Comparative Example 2

Artificial leather was manufactured using the same method as in Comparative Example 1, except that step 4) of manufacturing artificial leather with post-perforation treatment in Comparative Example 1 was omitted.

<Experimental Example>

The physical properties of the artificial leather manufactured in the above examples and comparative examples were measured using the following methods, and the results are shown in Table 1.

1. Exposure ratio of ventilation holes

For the artificial leather manufactured in the above examples and comparative examples, the surface was magnified 50 times using an optical microscope to compare the appearance of the perforated area and the non-perforated area. If a breathable hole was observed, it was judged as “exposed”, and if the appearance was similar to the non-perforated area, it was judged as “concealed”. The surface exposure ratio of the breathable hole was calculated using the following mathematical formula 1.

[Mathematical Formula 1]

Exposure ratio of breathable holes = (maximum diameter of breathable holes covered by the nap when viewed from the surface of the nonwoven fabric on which the nap is formed / maximum diameter of the breathable holes when viewed from the surface of the nonwoven fabric) * 100.

2. Average length of pile on ventilation hole

For the artificial leather manufactured in the above examples and comparative examples, the average length of the nap covering the ventilation holes (average length of the surface nap covering the perforated area) was measured when the surface of the nonwoven fabric on which the nap was formed was viewed at a magnification of 100 times using an optical microscope.

3. Breathability

The breathability (ml/cm ² *sec) of the artificial leather manufactured in the above examples and comparative examples was evaluated according to the Hyundai Motor Company technical standards (MS300-32, Article 4.18, Breathability Evaluation Criteria).

4. Tensile strength

The tensile strength of the artificial leather manufactured in the above examples and comparative examples was evaluated according to the Hyundai Motor Company technical standard (MS320-19, Type A-2, Section 4.3 Tensile strength evaluation criteria).

5. Tear strength

The tear strength of the artificial leather manufactured in the above examples and comparative examples was evaluated according to the Hyundai Motor Company technical standard (MS320-19, Type A-2, Clause 4.5, tear strength evaluation criteria).

division Exposure ratio of ventilation holes (%) Average length of pile on ventilation hole (㎛) Breathability (ml/cm ² ·sec) Tensile strength (kgf/cm) Tear strength (kgf) Example 1 6.5 181 5.3 11 2.5 Example 2 3.2 370 3.5 12 2.6 Example 3 38.3 118 6.4 9 2.2 Example 4 7.7 212 5.8 10 2.4 Example 5 6.1 188 2.8 12 2.7 Comparative Example 1 92.3 22 5.4 10 2.5 Comparative Example 2 0 - 2.0 14 3.1

As shown in Table 1 above, the artificial leather obtained in Examples 1 to 5 had an exposure ratio of breathable holes of 3.2% or more and 38.3% or less, and an average length of nap on the breathable holes of 118 ㎛ or more and 370 ㎛ or less, whereas the artificial leather obtained in Comparative Example 1 had an exposure ratio of breathable holes of 92.3%, which was excessively increased compared to the Examples, and the average length of nap on the breathable holes was 22 ㎛, which was confirmed to be thinner than the Examples. Through this, the artificial leather obtained in the Examples has a longer nap on the breathable holes than the artificial leather obtained in Comparative Example 1, so that it can prevent contamination by preventing foreign substances or dust from penetrating into the breathable holes, and can also implement excellent surface appearance characteristics.

Meanwhile, the artificial leather obtained in Comparative Example 2 had a limitation in that it was difficult to secure sufficient breathability compared to the example because there were no exposed breathable holes.

Claims (16)

non-woven fabric;
A breathable hole penetrating the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric; and
including a nap formed on at least one surface of the nonwoven fabric;
The exposure ratio of the ventilation hole according to the following mathematical formula 1 is 0.1% or more and 40% or less,
Artificial leather, wherein the average length of the nap covering the ventilation holes is 100 ㎛ or more and 400 ㎛ or less when viewed from the surface of the nonwoven fabric on which the nap is formed:
[Mathematical Formula 1]
Exposure ratio of breathable holes = (maximum diameter of breathable holes covered by the nap when viewed from the surface of the nonwoven fabric on which the nap is formed / maximum diameter of the breathable holes when viewed from the surface of the nonwoven fabric) * 100.
In the first paragraph,
Artificial leather having an exposure ratio of breathable holes according to the above mathematical formula 1 of 0.1% or more and 10% or less.
In the first paragraph,
Artificial leather, wherein the average length of the nap covering the ventilation holes is 150 ㎛ or more and 250 ㎛ or less when viewed from the surface of the nonwoven fabric on which the nap is formed.
In the first paragraph,
Artificial leather having a breathability of 2.5 ml/cm ² ·sec or more and 7.0 ml/cm ² ·sec or less according to the Hyundai Motor Company technical standard (MS300-32, Article 4.18, Breathability Evaluation Criteria) of the above artificial leather.
In the first paragraph,
Artificial leather having a tensile strength of 9 kgf/cm or more and 20 kgf/cm or less according to the Hyundai Motor Company technical standard (MS320-19, Type A-2, Clause 4.3 Tensile strength evaluation standard) of the above artificial leather.
In the first paragraph,
Artificial leather having a tear strength of 2.2 kgf or more and 5.0 kgf or less according to the Hyundai Motor Company technical standard (MS320-19, Type A-2, Clause 4.5 tear strength evaluation standard) of the above artificial leather.
In the first paragraph,
Artificial leather, wherein when viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole is 0.1 mm or more and 2.0 mm or less.
In the first paragraph,
Artificial leather having two or more of the above ventilation holes and a gap between adjacent ventilation holes of 1 mm or more and 8 mm or less.
In the first paragraph,
The artificial leather further comprises an elastic resin layer coated on the nonwoven fabric.
A step of forming a breathable hole penetrating the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric; and
A step of forming a nap on the nonwoven fabric surface in which the above-mentioned ventilation holes are formed;
A method for manufacturing artificial leather, wherein the exposure ratio of breathable holes according to the following mathematical formula 1 is 0.1% or more and 40% or less:
[Mathematical Formula 1]
Exposure ratio of breathable holes = (maximum diameter of breathable holes covered by the nap when viewed from the surface of the nonwoven fabric on which the nap is formed / maximum diameter of the breathable holes when viewed from the surface of the nonwoven fabric) * 100.
In Article 10,
A method for manufacturing artificial leather, wherein when viewed from the surface of the nonwoven fabric, the maximum diameter of the breathable hole is 0.1 mm or more and 2 mm or less.
In Article 10,
A method for manufacturing artificial leather, wherein the above-mentioned ventilation holes are two or more, and the interval between adjacent ventilation holes is 1 mm or more and 8 mm or less.
In Article 10,
In the step of forming a nap on the nonwoven fabric surface in which the above-mentioned ventilation holes are formed,
A method for manufacturing artificial leather, which involves grinding the surface of a non-woven fabric with sandpaper of Mesh #80 or higher and #240 or lower.
In Article 10,
Before the step of forming a breathable hole penetrating the inside of the nonwoven fabric from one surface of the nonwoven fabric to the opposite surface of the nonwoven fabric,
A method for manufacturing artificial leather, further comprising the step of impregnating a nonwoven fabric with an elastic resin.
A ventilated sheet comprising the artificial leather of the first clause.
A vehicle comprising a ventilated seat according to Article 15.