KR20170030244A - Artificial leather fabric for ventilating seat and manufacturing method thereof - Google Patents

Abstract

The present invention relates to polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU) artificial leather sheets; And an artificial leather back fabric joined to the artificial leather sheet; The present invention relates to an artificial leather fabric for a ventilating sheet impregnated with a polyurethane blend, buffing the synthetic fabric, and a method of manufacturing the artificial leather fabric. In the punching process, a napping protrudes between punching holes And the possibility of occurrence of fuzz due to abrasion is very low.

Description

Technical Field [0001] The present invention relates to an artificial leather fabric for a ventilation sheet,

The present invention relates to an artificial leather fabric for a ventilation sheet and a method of manufacturing the same, and more particularly to a synthetic leather material for a ventilation sheet, which is produced by punching artificial leather made of thermoplastic polyurethane (TPU) or polyvinyl chloride And to an artificial leather fabric for a ventilation sheet having a very low possibility of occurrence of napping due to abrasion and a method for manufacturing the same.

In recent years, ventilating seats have been installed in high-end or semi-mid-sized automobile specifications. Natural leather or polyurethane (PU) artificial leather is widely used as the material of the ventilating seat. As the residence time in automobiles increases, there is a growing demand from customers for sheets with excellent ventilation, and it is necessary to develop more affordable artificial leather punching products.

In recent years, artificial leather made of polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU) has been replaced with natural leather and polyurethane (PU) artificial leather with low price, but the main part except the side part, Due to technical problems, there are restrictions on the application of related products.

A method of manufacturing artificial leather sheets known to date is as follows.

Korean Patent Registration No. 10-0616738 (Patent Document 1) discloses a method for producing a nonwoven fabric comprising the steps of: a) preparing a back layer of a nonwoven fabric; b) dry coating the polyurethane blend solution on one side of the release paper in two stages to form a polyurethane film; c) arranging the nonwoven fabric and the polyurethane film so that they are in contact with each other; d) peeling off the release paper of the foam, and then processing the ply pattern on the upper surface of the polyurethane film; And the surface pattern of the TPU material is formed.

Korean Patent Registration No. 10-1266009 (Patent Document 2) discloses a method of manufacturing a double-layer fabric comprising a) preparing a backing layer by brushed or buffed the surface of a double-woven fabric; b) coating and drying the water-soluble urethane resin composition on the back side of the brushed or buffed fabric; A method of manufacturing an artificial leather of TPU material is disclosed.

Korean Patent Laid-Open Publication No. 10-2013-0130224 (Patent Document 3) discloses a TPU intermediate layer between a backing layer of a backing cloth for artificial leather and a skin layer of a thermoplastic polyurethane (TPU) film, And an artificial leather made of TPU material which increases the jointing force with the backing cloth, which is a back layer, is disclosed.

In the above description, only the manufacturing method of artificial leather of TPU material is exemplified. However, in the method of manufacturing artificial leather of PVC material, fiber backing and / or general nonwoven fabric is used as a backing layer of artificial leather. However, when punching artificial leather to produce a ventilation sheet, there is a problem in the quality of the lint such as the raw material of the cloth or the lint of the nonwoven fabric being loosened at the cutting hole, It is being raised. In addition, natural leather punching products and PU artificial leather punching products have raised quality problems such as excessively wrinkled sheets during sewing and covering.

Therefore, it is urgently required to develop new artificial leather fabrics useful for manufacturing ventilation sheet products.

Korean Patent Registration No. 10-0616738 Korean Patent Registration No. 10-1266009 Korean Patent Publication No. 10-2013-0130224

In the present invention, punching products of expensive natural leather or high-grade PU artificial leather are replaced with artificial leather of PVC or TPU, which is inexpensive, to solve problems such as excessive wrinkling of the sheet during sewing and covering, It is an object of the present invention to provide an artificial leather fabric which solves the problem of peeling between the sheet and the back layer and the problem of protruding the fleece between the punching holes.

Accordingly, it is an object of the present invention to provide artificial leather fabrics for ventilation sheets.

It is another object of the present invention to provide a method for manufacturing artificial leather fabrics for ventilation sheets.

In order to solve the above problems, the present invention relates to an artificial leather sheet of polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU); And an artificial leather back fabric joined to the artificial leather sheet; Wherein the back fabric is impregnated with a polyurethane blend liquid and the synthetic surface is buffed.

As a preferred embodiment of the present invention, the artificial leather raw fabric for a ventilation sheet of the present invention is characterized in that a polyurethane blend liquid is coated on the surface of the buffed back fabric and the synthetic resin leather is applied to an artificial leather sheet as an adhesive .

As a preferred embodiment of the present invention, the artificial leather fabric for a ventilation sheet of the present invention may be characterized in that the outer surface of the fabricated backing fabric is buffed and then coated with a polyurethane blend solution.

As a preferred embodiment of the present invention, the artificial leather fabric for a ventilation sheet of the present invention may be characterized in that the back fabric is a warp knitted fabric or a nonwoven fabric.

As a preferred embodiment of the present invention, the synthetic leather raw fabric for a ventilation sheet of the present invention is characterized in that the composition of the polyurethane blend liquid for coating the foamed surface of the impregnated or buffed back fabric is 28 to 35 wt% 0.5 to 2.0% by weight of a surfactant, 1.5 to 5.0% by weight of a pigment, and 58 to 70% by weight of dimethylformamide.

Another aspect of the present invention is directed to a method of making artificial leather fabrics for ventilation sheets,

I) making synthetic leather sheets of polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU);

Ii) impregnating and coagulating the backing fabric for artificial leather into the polyurethane blend;

Iii) washing and drying the back fabric with the polyurethane coagulated;

Iv) performing a buffing process on the surface of the dried back fabric;

V) coating the polyurethane blend solution on the blend side of the buffed back fabric;

(Vi) arranging the back fabric so that the back side of the back fabric is in contact with the artificial leather sheet of (i); And

() Punching the artificial leather soaped; And a method of manufacturing an artificial leather fabric for a ventilation sheet.

As a preferred embodiment of the present invention, the method for manufacturing artificial leather fabrics for ventilation sheets according to the present invention may further comprise a step of removing napping of the backing fabric between the buffing of step iv) and the coating of step v) .

As a preferred embodiment of the present invention, the method of manufacturing a synthetic leather raw fabric for a ventilation sheet according to the present invention is characterized in that the buffing in the step iv) and the coating in the step v) are performed simultaneously on the outer surface opposite to the sponge surface of the backing fabric . ≪ / RTI >

According to a preferred embodiment of the present invention, in the method for manufacturing a synthetic leather raw fabric for a ventilation sheet of the present invention, the back fabric of step ii) may be a warp knitted fabric or a nonwoven fabric.

As a preferred embodiment of the present invention, the method for producing artificial leather fabrics for ventilation sheets according to the present invention is characterized in that the polyurethane blend solution of the steps ii) and v) comprises 28 to 35% by weight of a polyurethane resin, 0.5 to 2.0% , 1.5 to 5.0% by weight of pigment and 58 to 70% by weight of dimethylformamide.

According to a preferred embodiment of the present invention, in the method for manufacturing artificial leather raw fabric for a ventilation sheet of the present invention, drying in step iii) is performed such that the water content of the back fabric is 30 to 35% by weight.

As a preferred embodiment of the present invention, the method for producing artificial leather fabrics for ventilation sheets of the present invention is carried out so that the polyurethane impregnation in step ii) and the polyurethane coating in step v) are 100 to 150 g / .

As a preferred embodiment of the present invention, the method for manufacturing artificial leather raw fabric for a ventilation sheet of the present invention is characterized in that the buffing in the step iv) and the coating in the step v) are carried out one to three times in succession have.

As a preferred embodiment of the present invention, the method of manufacturing a synthetic leather raw fabric for a ventilation sheet of the present invention is characterized in that the step (b) is performed by a thermocompression bonding process or an adhesive bonding process.

The artificial leather fabric according to the present invention has a low yarn occurrence rate even after punching, and the possibility of wear due to getting on and off the car is low, so that the problem of the napping quality protruding from the punching holes is remarkably improved.

In addition, the artificial leather fabric of the present invention has excellent economical efficiency due to a very low material cost and manufacturing cost as compared with existing natural leather products and high-quality polyurethane (PU) artificial leather products. The polyurethane blend liquid of specific composition So that the problem of excessive wrinkling of the sheet during sewing and covering is solved.

Thus, the artificial leather fabrics of the present invention can replace existing natural leather punching products or high quality polyurethane artificial leather punching products.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the production of a TPU artificial leather fabric produced by a conventional calendar method.
2 is a view showing the construction of a conventional TPU artificial leather.
Fig. 3 is a photograph showing a section of a synthetic leather obtained by putting a conventional back fabric (wet nonwoven fabric).
4 is a photograph showing a punching surface of artificial leather in which a conventional back fabric (air bubble) is assembled.
5 is a photograph showing a punching surface of artificial leather in which a conventional backing fabric (nonwoven fabric) is laminated.
Fig. 6 is a view showing a state (a) of the knitted structure and a state (b) of the tricot structure.
Fig. 7 is a photograph of a punching artificial leather specimen (a) produced by using a knitted fabric as a back fabric and a punching artificial leather specimen (b) produced by using a fabric which is made of a tricot structure as a backing fabric to be.
FIG. 8 is a photograph (a) showing the napping and wrinkling state of the punching artificial leather produced by the conventional method, and a photograph (b) showing the punching state of the artificial leather fabric using the backing fabric produced according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the present invention, a detailed description of related processes or configurations will be omitted so as not to obscure the gist of the present invention.

Artificial leather, generally made of thermoplastic polyvinyl chloride (PVC) or polyurethane (TPU), is manufactured by the calendering method. Fig. 1 is a schematic view showing a manufacturing process of artificial leather fabrics by a conventional calendar method. In the general calendar method according to FIG. 1, a process of sheet-making a polymer obtained by blending and kneading a raw material of PVC or TPU through a calender process; A mold release process for fabricating a backing fabric on a sheet; A sheet foaming step of making a certain thickness to provide the required physical properties as artificial leather; And a surface treatment process; To produce artificial leather fabrics.

Fig. 2 shows the construction of artificial leather made by the calender method according to Fig. The artificial leather fabric of Fig. 2 comprises a back side monolayer of nonwoven fabric; A foam layer of thermoplastic polyurethane (TPU); TPU sheet layer; And the surface treatment layer is sequentially stacked.

Fig. 3 shows a cross-section of a synthetic leather obtained by adding a conventional backing fabric (wet nonwoven fabric). 3, since the napkin is formed on the lower surface of the back fabric, the napping occurs due to yarn splitting during punching operation. Particularly, as the material of the backing fabric of PVC or TPU artificial leather, knit tissues or nonwoven tissues of the top-circular knit, the warp knit-tricot, and the rascel are mainly used. In the punching operation, fibers are cut off and the fibers or fibers are climbed on the sheet surface of artificial leather to form fluffs or punch holes, thereby deteriorating the design and quality of products.

Fig. 4 is a photograph showing a punching surface of a synthetic leather prepared by using a cloth base as a back fabric according to a conventional method. According to FIG. 4, it can be confirmed that fluffs are generated during the punching operation by using the bubbles as the back fabric.

5 is a photograph showing a punching surface of artificial leather prepared by using a nonwoven fabric as a back fabric according to a conventional method. According to FIG. 5, it can be seen from photographs that the fibers were cut off during the punching operation, and these fluffs come up on the surface of the artificial leather due to abrasion during the getting on and off of the vehicle, or the hole of the ventilation sheet is blocked.

The present invention has been developed in order to solve the problems of the prior art described above, and there is no fear of closing the holes of the ventilating sheet by the fluffs because no fuzzing occurs on the surface of the PVC or TPU artificial leather fabric by the punching operation.

The artificial leather fabric for a ventilation sheet according to the present invention and its manufacturing method will be described in more detail as follows.

Artificial leather fabrics for ventilation sheets in accordance with the present invention include artificial leather sheets of polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU); And an artificial leather back fabric joined to the artificial leather sheet; . In particular, the artificial leather fabric of the present invention is characterized by a back fabric, wherein the back fabric is impregnated with a polyurethane blend solution and buffed on the fabric blend surface. In other words, since the artificial leather raw fabric of the present invention has the backing fabric impregnated and coagulated with a polyurethane blend liquid of a specific composition, it has its own elastic force, and thus wrinkles of the sheet are not generated during the sewing covering, The backing fabric is buffed so as to improve the adhesion between the backing fabric and the artificial leather sheet to improve the peeling property and prevent the occurrence of fluff of the long file.

In addition, the artificial leather fabric of the present invention may be coated with the polyurethane blend solution after buffing the outer surface of the reverse side as well as the blending surface of the back fabric in order to further improve the nap quality. Thus, if the outer surface of the reverse side of the synthetic leather sheet is coated with buffing and polyurethane, it is possible to minimize the possibility of napping not only during the punching operation but also during abrasion upon boarding and getting off.

The polyurethane blend liquid used in the present invention comprises 28 to 35% by weight of a polyurethane resin, 0.5 to 2.0% by weight of a surfactant, 1.5 to 5.0% by weight of a pigment and 58 to 70% by weight of dimethylformamide.

The polyurethane resin may be a material used in the production of a wet polyurethane. For example, a polyurethane or a copolymer type (COPOLYMER TYPE) may be preferably applied. If the content of the polyurethane resin contained in the polyurethane blend solution is less than 28% by weight, the filling rate may be insufficient and the quality of sensibility may be insufficient. When the content of the polyurethane resin is more than 35% by weight, the filling rate may be high, Emotional quality is one of automobile quality standards. It refers to feeling of being luxurious or good when it is touched by sight as a sense of sensation and tactile sense by a person, and refers to appearance quality and surface sensibility (cushion and / or softness ) And the like.

The surfactant is used for the purpose of dispersibility, and for example, a modified silicone system may be used. If the content of the surfactant contained in the polyurethane blend is less than 0.5% by weight, the dispersibility may deteriorate and problems may arise in the portions related to the uniformity. If the content exceeds 2.0% by weight, the increase in the effect depending on the content is insignificant, .

The pigment is used for the purpose of color reproduction of artificial leather or the like, and may include a color imparting component and an adhesion imparting component. For example, pigments of various colors for coloring and VEHICLE PU RESIN for adhesion. If the content of the pigment contained in the polyurethane blend solution exceeds 5.0 wt%, it may cause a problem due to dye transfer. Therefore, the pigment is preferably contained in an amount of 5.0 wt% or less. In order to ensure the appearance quality of the product, By weight or more.

If the content of dimethylformamide contained in the polyurethane blend is less than 58% by weight, the viscosity of the blend may be high and the workability may be poor. When the content of the blend is more than 70% by weight, The viscosity is lowered and the application amount is decreased and the drying speed is lowered, so that the workability may be deteriorated.

When the backing fabric is impregnated in the polyurethane blend liquid having the above-described composition characteristics, the original elasticity of the polyurethane material is imparted and wrinkles are not generated at the time of the bar material and covering.

As described above, the artificial leather fabric of the present invention uses a back fabric having improved nap quality and elasticity to solve the problem of excessive wrinkling which is pointed out as a disadvantage in existing natural leather products or advanced PU products, Or TPU punching products. ≪ Desc / Clms Page number 2 >

On the other hand, the present invention is also characterized by a method for manufacturing artificial leather fabrics for ventilation sheets. According to the manufacturing method according to the present invention, there is provided a method of manufacturing a synthetic leather sheet, comprising the steps of: i) forming an artificial leather sheet of polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU); Ii) impregnating and coagulating the backing fabric for artificial leather into the polyurethane blend; Iii) washing and drying the back fabric with the polyurethane coagulated; Iv) performing a buffing process on the surface of the dried back fabric; V) coating the polyurethane blend solution on the blend side of the buffed back fabric; (Vi) arranging the back fabric so that the back side of the back fabric is in contact with the artificial leather sheet of (i); And (e) punching the applied artificial leather; . ≪ / RTI >

The method of manufacturing the artificial leather material for a ventilation sheet according to the present invention will be described in more detail as follows.

I) step is the step of making artificial leather sheet. Artificial leather sheets can be made into sheets by calendering using calender rolls used in the manufacture of ordinary artificial leather. PVC or TPU can be used as a typical material of artificial leather sheet.

Step ii) is a step of impregnating and solidifying the backing fabric for artificial leather into the polyurethane blend liquid. Natural fibers, artificial fibers or synthetic fibers may be used as the material of the backing fabric, but synthetic fibers such as polyethylene terephthalate (PET) or a mixture of PET and cotton may be preferably used.

Further, as the back fabric, a fabric, a knitted fabric or a nonwoven fabric may be used, and preferably a warp knitted fabric or a nonwoven fabric may be used.

Fig. 6 shows the state (a) of the knitted structure and the state (b) of the tricot structure. It is preferable to use a warp knitted fabric such as a tricot for the back fabric. 6 (a)) such as a single knit or a double knit may cause a lot of trimming in the punching process, but the warp knitting structure of the tricot (Fig. 6 (b) It can be more preferable to apply it as a back fabric because it does not loosen much. Further, it is preferable to use a microfine nonwoven fabric, a divider yarn nonwoven fabric or a tricot suede microfibre fabric as a backing fabric in view of adhesion with an artificial leather sheet.

7A and 7B are photographs showing a comparison between the case (a) where punching is performed using a knitted fabric as a back fabric and the case (b) where punching is performed using a fabric having a tricot structure as a back fabric. It can be seen that the yarn is not loosened well even after the punching process and the fluff is less generated in the back fabric (b) employing the tricot structure.

In the present invention, the above-mentioned backing fabric is impregnated and coagulated in the polyurethane blend liquid. For impregnation, the backing fabric is fed into the impregnation tank containing the polyurethane blend liquid, and the polyurethane blend liquid is infiltrated into the backing fabric, thereby increasing the concentration of individual fibers in the backing fabric. At this time, the impregnated amount of the polyurethane blend solution is adjusted so that the weight after drying is in the range of 100 to 150 g, as compared with the area (m2) of the back side fabric. If the amount of impregnation of the polyurethane blend liquid is less than 100 g / m < 2 >, the effect of imparting elasticity to the fabric may be insufficient and excessive wrinkling may occur during sewing and covering. If the amount is more than 150 g / m & I do not. The polyurethane (PU) blend liquid preferably maintains a composition ratio of 28 to 35% by weight of a polyurethane resin, 0.5 to 2.0% by weight of a surfactant, and 58 to 70% by weight of dimethylformamide for the reasons described above. The backing fabric impregnated with polyurethane is put into water and solidified.

Step iii) is a step of washing and drying the back fabric with the polyurethane coagulated. The flushing is a process for removing the remaining dimethylformamide or the like on the back fabric. When washing is completed, the back fabric is dried by heat treatment in a drying chamber, and the drying is performed so that the moisture content of the fabric is about 30 to 35% by weight.

In addition, the polyurethane-impregnated back fabric may be subjected to a process for producing a conventional advanced nonwoven PU wet base or a process for producing a microfiber or a divisible nonwoven fabric, unless otherwise specified.

The backing fabric having undergone the polyurethane impregnation process is provided with elasticity to improve the problem of excessive wrinkling in the process of sheet production, and it is also provided with an adhesive force so that the PVC or TPU artificial leather sheet is well- .

Step iv) is a step of performing the buffing process on the surface of the dried back fabric. This step is intended to give a stronger adhesive force to the back fabric, and it is expected that the buffing process is further applied to the polyurethane-impregnated surface to further improve the adhesive strength when the PVC or TPU artificial leather sheet is mixed with the sheet have. The buffing can be carried out by a conventional method.

Step v) is a step of coating the polyurethane blend liquid on the blend side of the buffed back fabric. In the present invention, a process for coating a buffered foamed surface with polyurethane is performed for the purpose of further improving the napping quality and the adhesive force. It is possible to grasp the fluff present on the buffered surface through the polyurethane coating, thereby substantially eliminating the possibility of napping due to wear as well as the case of the yarn structure. The coating can be carried out using the polyurethane blend used for impregnating the back fabric, and can be carried out according to a conventional coating method. It is preferred that the polyurethane coating on the buffed surface is 100 to 150 g / m 2 based on the dry weight. If the coating amount of the polyurethane is less than 100 g / m 2, the effect of improving the lint quality and adhesion can not be sufficiently obtained. If the coating amount exceeds 150 g / m 2, the product becomes hard and the surface brushed state is deteriorated, .

Further, in the present invention, in order to further reduce the possibility of napping of the back fabric, the surface file of the back fabric impregnated prior to carrying out the polyurethane coating step is cut shorter after the iv) buffing step, And a step of removing irregularly occurring nappy may be further performed. To provide excellent fuzz quality, the fuzz removal may be carried out more than once, preferably twice. Further, depending on the conditions of use of the automobile, if the possibility of lint generation is high, it may be carried out three to four times.

Also, the iv) buffing step and v) polyurethane coating step according to the present invention are carried out in order to further improve the adhesion between the backing fabric and the artificial leather sheet, and the buffing and coating are performed one to three times or more More than that can be done repeatedly.

In addition, in the present invention, buffing and polyurethane coating may be further applied to the outer surface of the half surface as well as the surface of the back fabric in the step (iv) and the step (v) of polyurethane coating. Since the outer surface of the reverse side of the backing cloth, which is formed on the artificial leather sheet, is further coated with buffing and polyurethane, the artificial leather fabric can minimize the possibility of napping not only during punching operation but also during wear and tear have.

Step vi) is a step of knitting a bicomponent fabric to an artificial leather sheet. The bonding can be carried out by a thermocompression bonding process or an adhesive bonding process. The thermocompression process is preferably carried out at a temperature of 70 to 220 ° C. If the thermocompression-bonding temperature is less than 70 ° C, the plasticity is low, which is not preferable for molding. If the temperature is more than 220 ° C, the physical properties of the backcoat are undesirably affected. The bonding process can be carried out according to a conventional method used in this technical field. As a result, PVC or TPU artificial leather sheets can be further adhered to and gripped on the back fabric when adhered to the back fabric by an adhesive or a thermo compression process to further reduce the occurrence of fluff.

Step (b) is a step of manufacturing artificial leather fabrics for a ventilation sheet for a ventilation sheet by punching the synthetic leather. The punching can generally be carried out according to a punching process used in the production of ventilation sheets of natural leather or PU artificial leather.

Fig. 8 is a photograph comparing the punching state of artificial leather fabrics produced by the conventional method (a) and the inventive method (b). That is, (a) is a photograph of a punching product of artificial leather in which a back fabric manufactured by a conventional method is assembled, and (b) is a photograph of a punching product of artificial leather in which a fabric is tricot-suede. According to FIG. 8, it can be confirmed that the artificial leather raw fabric b produced according to the present invention has the surface of the punched artificial leather cleanly cut off and that no nap is generated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge of.

Claims (13)

Artificial leather sheets of polyvinyl chloride (PVC) or of thermoplastic polyurethane (TPU); And
A backing fabric for artificial leather,
Wherein the backing fabric is impregnated with a polyurethane blend, and the blending surface is buffed.
The method according to claim 1,
Characterized in that a polyurethane blend liquid is coated on the surface of the above-mentioned buried back fabric, and the polyurethane blend is applied to an artificial leather sheet as an adhesive.
The method according to claim 1,
Characterized in that the outer surface of the impregnated backing fabric is coated with a polyurethane blend after buffing.
The method according to claim 1,
And the back fabric is a warp knitted fabric or a nonwoven fabric.
4. The method according to any one of claims 1 to 3,
Characterized in that the polyurethane blend liquid comprises 28 to 35% by weight of a polyurethane resin, 0.5 to 2.0% by weight of a surfactant, 1.5 to 5.0% by weight of a pigment and 58 to 70% by weight of dimethylformamide. .
I) making synthetic leather sheets of polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU);
Ii) impregnating and coagulating the backing fabric for artificial leather into the polyurethane blend;
Iii) washing and drying the back fabric with the polyurethane coagulated;
Iv) performing a buffing process on the surface of the dried back fabric;
V) coating the polyurethane blend solution on the blend side of the buffed back fabric;
(Vi) arranging the back fabric so that the back side of the back fabric is in contact with the artificial leather sheet of (i); And
() Punching the artificial leather soaped;
≪ / RTI >
The method according to claim 6,
Further comprising the step of removing the napping of the backing fabric between the buffing of step iv) and the coating of step v).
The method according to claim 6,
Wherein the buffing in step iv) and the coating in step v) are simultaneously performed on the outer surface opposite to the surface of the backing fabric.
The method according to claim 6,
Wherein the back fabric of step ii) is a warp knitted fabric or a nonwoven fabric.
The method according to claim 6,
The polyurethane blend liquid of the steps ii) and v) is composed of 28 to 35% by weight of a polyurethane resin, 0.5 to 2.0% by weight of a surfactant, 1.5 to 5.0% by weight of a pigment and 58 to 70% by weight of dimethylformamide Wherein the ventilating sheet is made of synthetic leather.
The method according to claim 6,
Wherein the polyurethane impregnation in the step (ii) and the polyurethane coating in the step (v) are carried out at 100 to 150 g / mm < 2 >.
The method according to claim 6,
Wherein the buffing in step iv) and the coating in step v) are carried out one to three times in succession.
The method according to claim 6,
Wherein the step (b) is carried out by thermocompression bonding or adhesive bonding.

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