KR101143404B1 - Manufacturing method of light weight nonwoven fabric complex for artificial leather and light weight nonwoven fabric complex thereby - Google Patents

Abstract

The present invention relates to a method for producing a composite nonwoven fabric sheet, which comprises: a first step of binding a reinforcing fabric to a fiber nonwoven fabric section by needle punching to produce a low density composite nonwoven fabric sheet; A second step of padding the produced low density composite nonwoven fabric sheet with a PVA aqueous solution; A third step of calendering the padded composite nonwoven fabric sheet in a wet state using a calender composed of upper and lower steel rolls to increase densification; And a fourth step of heat treating the densified sheet at a temperature of 150 to 180 ^° C. The present invention also provides a method for producing a composite nonwoven fabric for artificial leather and a composite nonwoven fabric for artificial leather.
According to the present invention, it is possible to produce a lightweight, flocked composite nonwoven fabric having an apparent fiber density of 0.24 to 0.45 g / cm ³ at a high density and at the same time exhibiting excellent durability and shape stability without using any heat-shrinkable synthetic fiber or organic solvent .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a composite nonwoven fabric for artificial leather and a lightweight synthetic nonwoven fabric for artificial leather,

The present invention relates to a method for producing a composite nonwoven fabric for artificial leather which is light in weight and a composite nonwoven fabric for lightweight synthetic sole by the same, and more specifically to a method for producing a lightweight synthetic woven fabric by densifying a low density composite nonwoven fabric sheet through wet calendering, The present invention relates to a method for producing a composite nonwoven fabric for artificial leather having excellent shape stability and durability as compared with general nonwoven fabrics, and to a composite nonwoven fabric for artificial leather which is thereby reduced in weight.

Conventional polyurethane artificial leather is generally manufactured by impregnating or applying a polyurethane resin or the like on a substrate. The manufacturing method is largely classified into a wet type method and a dry type method, and is classified into a mouth type (suede type) and a silver type (coating type) And is differentiated from synthetic leather produced using polyvinyl chloride (PVC) resin in terms of production method, physical properties and harmfulness.

Artificial leather is a substitute material of natural leather because of advantages such as lower price, superior physical properties, mass production, various appearance and high functionality compared with natural leather. It is used in various industrial fields such as clothing, shoes, sporting goods, It is being used.

In order for artificial leather to be completed with various consumer products, it is usually made through cutting, sewing, and other processes. Therefore, it requires a lot of manpower and automation of the equipment is limited, and it is difficult to sew various and elaborate patterns .

As a technique for solving the disadvantages of sewing described above, Patent Document 1 discloses a non-sewn polyurethane artificial leather made by a conventional dry polyurethane artificial leather manufacturing method using a thermoplastic or thermosetting sheet as a base material . However, the artificial leather thus formed is to be adhered to various conventional materials and molded into a shoe upper material. However, the artificial leather is not limited to ordinary materials such as natural leather, synthetic leather, nonwoven fabric, woven fabric or polyurethane There is no particular mention as a substrate suitable for the manufacture of artificial leather of the non-seal type.

In the case of producing artificial leather using a TPU or a hot-melt film, the TPU or the hot-melt film must be melted and adhered to the base material by heat pressurization or high-frequency wave, so that the base material used for the artificial leather of the non- It is possible to obtain a film having a low weight and a thickness as low as possible in order to exhibit a good adhesive force even when energy is used even when the film resin reaches a melting point and to have a high density of surface layer capable of maintaining a uniform adhesive strength due to adhesion, Sufficient durability and shape stability to meet durability requirements are also required at the same time.

On the other hand, fabric materials used for forming a coating layer and durability during production of general artificial leather usually include woven fabrics, knitted fabrics and nonwoven fabrics, but the fabrics and knitted fabrics are made of artificial leather having a cross- And it is recognized that nonwoven fabric having a three-dimensional structure similar to that of natural leather is suitable for cross-section and structure in order to be recognized as high-quality synthetic leather.

The above-mentioned conventional nonwoven fabric as artificial leather base material can be produced by using a heat-shrinkable fiber material as in Patent Document 2, for example, in order to enhance the quality and physical properties from ordinary nonwoven fabric of low density and low- As in Patent Document 3, advanced high-density nonwoven fabric has been developed by a method of treating a nonwoven fabric with an organic solvent capable of expanding and shrinking general synthetic fibers to increase the density.

However, when the high-density nonwoven fabric is used as a base material for sewing artificial leather due to its high physical properties such as high densification and sensitivity, it is not difficult to manufacture high quality sewing artificial leather. However, it is difficult to manufacture lightweight, non- It is difficult to apply it to a sewing or non-sewing artificial leather requiring the use of a green cloth, and it requires a lot of energy even if it is applied, and it is difficult to infiltrate the molten film resin due to high density formed up to the inside, There is a limit to the manufacture of artificial leather.

Unlike the above-mentioned high-density nonwoven fabric, the conventional low density general nonwoven fabric can be sufficiently lightweight, but since the unit weight of the nonwoven fabric must be considerably lowered in order to make it thinner due to low fiber density, it is sufficient when used as a base material of synthetic leather for shoes or goods It is difficult to maintain durability, form stability and adhesive strength, and in particular, since the uniformity of fiber density of the adhesive surface is poor, a jumping phenomenon of adhesive strength occurs and heterogeneous adhesive properties are exhibited. In addition, artificial leather made from the above-mentioned general nonwoven fabric has a limited surface to be wrinkled and hard to be used as a shoe-making material due to hardness of touch.

Korean Patent Publication No. 344110 Korean Patent Publication No. 217498 Korean Patent Publication No. 861541

It is an object of the present invention to provide a method for producing a composite nonwoven fabric for artificial leather which is lightweight and has excellent form stability and durability as compared with a general nonwoven fabric of the same weight by densifying a low density composite nonwoven fabric sheet through wet calendering.

Another object of the present invention is to provide a composite nonwoven fabric for artificial leather according to the above method.

It is still another object of the present invention to provide a polyurethane artificial leather using the composite nonwoven fabric for artificial leather.

In order to accomplish the above object, the present invention provides a method for manufacturing a composite nonwoven fabric for artificial leather, comprising the steps of: (a) bonding a reinforcing fabric to an end face of a nonwoven fabric by needle punching to produce a low density composite nonwoven fabric sheet; A second step of padding the produced low density composite nonwoven fabric sheet with a PVA aqueous solution; A third step of calendering the padded composite nonwoven fabric sheet in a wet state using a calender composed of upper and lower steel rolls to increase densification; And a fourth step of subjecting the densified sheet to a heat treatment at 150 to 180 ^° C.

The weight of the reinforcing fabric bound to the end face of the fibrous nonwoven fabric in the first step is preferably in the range of 15 to 30% by weight based on the weight of the low density composite nonwoven fabric sheet.

The unit weight of the reinforcing fabric is preferably 20 to 50 g / m ² or less.

The low density composite nonwoven fabric sheet produced in the first step preferably has a weight per unit area of 100 to 180 g / m ² including a reinforcing fabric.

The PVA concentration in the PVA-aqueous solution padded in the second step is preferably 1 to 5% by weight.

The wet calendering in the third step is preferably performed in two or three multi-steps.

It is preferable that the moisture content of the nonwoven fabric after Calendinding's final wet-wax calendering is in the range of 0 to 5% by weight.

The composite nonwoven fabric for artificial leather produced by the present invention preferably has an apparent fiber density of 0.24 to 0.45 g / cm ³ .

According to the present invention, it is possible to provide a lightweight, lightweight, and lightweight fiber having a density of 100 to 180 g / m < ² > that exhibits high densities in the range of an apparent fiber density of 0.24 to 0.45 g / cm < ³ > and excellent durability and shape stability without using any heat shrinkable synthetic fibers or organic solvents. It is possible to obtain a smooth synthetic leather and a lightweight, thinned artificial leather having no surface unevenness.

In addition, when the composite nonwoven fabric produced according to the present invention is used as a base material for sewing, or in particular, artificial leather for footwear or general merchandise made of non-woven fabric, the coating layer or the adhesive layer is lightweight and thin with uniform adhesive strength of 4.0 kg / It is possible to manufacture a silver-type artificial leather having a stable shape, which is effective for making a lightweight shoe or miscellaneous goods which can satisfy recent trends.

The manufacturing cost can be reduced by densifying the nonwoven fabric without using expensive heat-shrinkable synthetic fibers, and there is an additional advantage in terms of environment-friendliness by eliminating the use of the organic solvent which is harmful to the environment in the course of high density.

A method for producing a composite nonwoven fabric for artificial leather according to the present invention comprises the steps of: (a) bonding a reinforcing fabric to an end face of a nonwoven fabric by needle punching to produce a low density composite nonwoven fabric sheet; A second step of padding the produced low density composite nonwoven fabric sheet with a PVA aqueous solution; A third step of calendering the padded composite nonwoven fabric sheet in a wet state using a calender composed of upper and lower steel rolls to increase densification; And a fourth step of subjecting the densified sheet to a heat treatment at 150 to 180 ^° C. Hereinafter, the present invention will be described in detail.

[Step 1: Production of low density composite nonwoven fabric sheet]

The first step in the method for producing a composite nonwoven fabric for artificial leather of the present invention is a step of binding a reinforcing fabric to the end face of a nonwoven fabric by needle punching to produce a composite nonwoven fabric sheet of low density.

In the first step, the fibers usable as the fibrous nonwoven fabric may be all synthetic fibers in the form of short fibers such as nylon, polyester, or acrylic, either singly or in combination, and it is not necessary to mix heat-shrinkable fibers. In addition, natural fibers such as cotton and hemp may be used instead of ordinary synthetic fibers, if necessary, so that the fiber material used is not particularly limited.

However, it is preferable that the thickness of the fibers used as the fibrous nonwoven fabric used at this time is smaller than the thickness of the single fibers constituting the yarn used in the reinforcing fabric described later. This is because when the composite nonwoven fabric is heated and pressed by wet calendering in a process to be described later, it acts positively between the yarns constituting the reinforcing fabric of the synthetic fibers used in the composite nonwoven fabric or between the weaving spaces, Because it can provide an advantageous aspect.

The reinforcing fabric bound to the end face of the fibrous nonwoven fabric may be used singly or in the form of a single filament yarn or a long filament yarn in the form of nylon or polyester. Preferably, filament yarns are used rather than yarns. This is because it is more advantageous in ensuring surface uniformity and durability of the composite nonwoven fabric compared to the same standard spun yarn fabrics, and particularly since the punching resistance is low during needle punching, the insertion of the fabric into the nonwoven fabric is advantageous. The kind of constituent fibers is not particularly limited. In this case, it is preferable that the long fiber yarn used is selected from a lead-free one rather than a flexible one, but it is also possible to use a woven fabric using a mixture of soft and non-leadable materials when the difficulty in weaving work or the occurrence of defects is concerned.

The reinforcing woven fabric bound to the end face of the fibrous nonwoven fabric is preferably selected appropriately within a range of the weight ratio of the final composite nonwoven fabric to the weight of the composite nonwoven fabric within a range from 10 to 30 wt% Is more preferable. The typical configuration of the nonwoven fabric is distinguished from a fabric exhibiting a two-dimensional structural characteristic in that the cross-sectional structure has a three-dimensional shape due to the bonding of the single fibers themselves. However, when the composition ratio of the reinforcing fabric in the composite nonwoven fabric exceeds 30%, it results in lowering the three-dimensional cross-sectional characteristics of the nonwoven fabric, which makes it difficult to justify the characteristics of the nonwoven fabric. On the other hand, when the content is less than 10% by weight, the purpose of contributing to durability and form stability of the composite nonwoven fabric becomes insufficient, making it difficult to meet the use as a lightweight synthetic resin base material.

In order to reduce the weight of the composite nonwoven fabric, it is preferable that the reinforcing woven fabric has a unit weight of 20 to 50 g / m ² by itself. And more preferably in the range of 20 to 40 g / m ² . As the composite nonwoven fabric becomes heavy, the artificial leather using the synthetic nonwoven fabric can not be distinguished as a non-woven synthetic leather because the weight of the composite nonwoven fabric gradually increases away from the lightening weight of the present invention.

The fiber appropriately selected by the above method is subjected to a conventional needle punching nonwoven fabric manufacturing process in order to form a low density composite nonwoven fabric sheet as a desired artificial leather base material. In other words, when the horn rubbing is carried out, the fibers are discharged to the web through the carding, and the web is laminated to the weight corresponding to the purpose of lighter weight through cross lapping, and then formed into a fleece. The reinforcing fabric is then attached to one end surface of the fleece. When punched on both sides, the fibers are transferred and bonded between the yarns constituting the reinforcing fabric or between the weaving spaces to obtain a middle density low density composite nonwoven fabric sheet in which the reinforcing fabric is inserted into the nonwoven fabric. There are no specific limitations on needle punching. The reinforcement fabric can be changed and modified in accordance with the standard such as the weight of the nonwoven fabric to be made so that the fabric is less damaged and inserting is sufficient.

The low density composite nonwoven fabric sheet produced by the above method preferably has a weight per unit area of 100 to 180 g / m ² including a reinforcing fabric for lightening purposes. When the unit weight of the low density composite nonwoven fabric sheet is less than 100 / m ² , there is a problem in securing durability as required. When the unit weight is more than 180 g / m ² , it is difficult to reduce the weight. Return to normal nonwoven or artificial leather category currently in use.

Wherein the intermediate product as a low-density composite nonwoven fabric produced in step 1 is equipped with sheet eoteuna basic conditions for a weight failure to form a thin thickness according to the apparent fiber density of 0.17g / cm ³ low-density characteristics into a range of less than of, in particular It is insufficient to be used as a base material of artificial leather of non-woven form which requires a blush.

[Second Step: Padding Treatment of PVA Solution]

The second step of the present invention is a step of padding the PVA-aqueous solution to the low density composite nonwoven fabric sheet produced in the first step. That is, the composite nonwoven fabric sheet having a low density prepared by the above needle punching is densified by the wet calendering according to the present invention to exhibit flaking characteristics, and then, 95 to 99% by weight of water and a water-soluble polyvinyl alcohol (PVA) resin 1 To 5% by weight of PVA aqueous solution, and then taken out at a pick-up rate of about 100% to paddle the PVA aqueous solution.

The PVA resin used in the PVA aqueous solution padding treatment step functions as a lubricant that reduces friction between fibers before the composite nonwoven fabric padded with an aqueous solution of PVA is dried and functions to fix the nonwoven structure after drying . At this time, if the concentration of the water-soluble PVA resin in the PVA aqueous solution used exceeds 5% by weight, sliding action between the calender and the nonwoven fabric surface is excessively increased at the time of heating and pressing in accordance with the progressive wet calendering, It may not be suitable for the purpose of compacting the fibers into the inside of the reinforcing fabric, and the PVA resin may adhere to the heated calender roll to adhere and cause quality problems.

In addition, although it is possible to use only water instead of PVA aqueous solution, since the lubrication exhibited by the aqueous PVA solution is reduced, the ability to concentrate the fibers between the reinforcing fabrics due to the pressure is insufficient and the density of the nonwoven fabric is insufficient. It is preferable to treat the PVA aqueous solution falling within the above-mentioned weight percentage range. The PVA used in the PVA aqueous solution is not particularly limited, and any conventional PVA can be used in the present invention. However, in order to lower the viscosity of the PVA aqueous solution and facilitate the penetration into the nonwoven fabric, the temperature of the PVA aqueous solution is preferably heated to within a range of 50 to 70 ^° C.

If the lubricant is further added to the fiber to improve the densification of the fiber during wet calendering, which will be described later, addition of a conventional lubricant such as a fabric softening agent causes excessive lubrication, Which is difficult to obtain a satisfactory high-density composite nonwoven fabric.

[Step 3: Densification]

In the third step, the composite nonwoven fabric sheet padded with the PVA-aqueous solution in the second step is sequentially and plurally treated in a wet state by a calender composed of upper and lower steel rolls before being completely dried while passing through a heating drum for drying The density of the nonwoven fabric is increased as the nonwoven fabric is dried.

As a conventional method for pressing the thickness of the nonwoven fabric and improving the smoothness of the surface, a calendering method in which a nonwoven fabric is passed through between two heated steel rolls is used. However, conventional calendering is a method of treating a dry nonwoven fabric at a high temperature and a high pressure for a short time at a time. In this method, high heat is concentrated only in the vicinity of the nonwoven fabric surface and is pressed to help smooth the surface of the nonwoven fabric. A flattening phenomenon is generated to prevent the penetration of the coating or the adhesive resin, resulting in an unsatisfactory bonding strength, and at the same time, a gradient of the fiber density along the cross section of the nonwoven fabric is generated and the artificial leather prepared by impregnating and coating the polyurethane resin There is a problem in that it shows a hard texture and a poor surface wrinkle property.

When calendering is performed under unreasonable heating and pressurizing conditions in order to increase the density of the nonwoven fabric in a dry state to an apparent fiber density of 0.24 g / cm ³ or more, a thickness gradient in the width direction of the nonwoven fabric occurs due to the minute warping of the calender roll, There is a problem that it is a factor of occurrence of defects.

Therefore, in order to solve the above problems, the present invention has devised a wet calendering method as a method for increasing the apparent fiber density of a composite nonwoven fabric without using any heat-shrinkable fibers.

The wet calendering is preferably performed in a multi-step process two to three times before the PVA resin is completely fixed as the composite nonwoven fabric with padded PVA aqueous solution is dried. Since the PVA resin in the nonwoven fabric is not completely fixed by only one wet calendering before the nonwoven fabric is completely dried, the structure of the nonwoven fabric is relaxed due to the evaporation of moisture and the process tension in the subsequent drying process, It is insufficient to form a sufficiently high density and a uniform surface density distribution. It can also be processed more than 4 times, but it is not advantageous in process management complexity and energy consumption.

The calendering pressure can be adjusted in a range of 2 to 5 kg / cm ² depending on the situation, but preferably not exceeding ⁵ kg / cm ² . This is because if the calendering is carried out with too much pressure, a fine gradient (warp) of the calender roll is generated, which may cause a thickness variation in the width direction of the nonwoven fabric.

In the wet calendering, the temperature of the calender drum is not particularly limited, but may be selected in accordance with the weight of the nonwoven fabric to be treated and may be differentially distributed with increasing temperature from the front to the back depending on the recovery rate, As shown in FIG. However, it is preferable that the moisture content of the nonwoven fabric after the last wet-wax calendering is selected and distributed so as to fall within the range of 0 to 5 wt%. The reason for controlling the moisture content of the last cycle is to prevent the overpressure of the surface layer of the nonwoven fabric due to the high pressure and high temperature contact in the last heat treatment (multi-calendering). If necessary, a preliminary drying process using a roll type or felt type drier may be added before the calendering of each cycle, wherein the temperature of the wet calender roll is in the range of 90 to 110% .

[Step 4: Heat treatment]

The nonwoven fabric having a moisture content in the range of 0 to 5 wt%, which has passed through the wet calendering of the last recovered car, is finally post-treated for the purpose of improving the surface smoothness of the nonwoven fabric, alleviating the surface layer density deviation and fixing the fiber density. The post-treatment is carried out at a high temperature in the temperature range of 150 to 180 ^° C and is carried out by a heat treatment means composed of a steel roll, for example, a plurality of dryers or calender rolls to finally complete a composite nonwoven fabric for artificial leather.

According to the content of the present invention, the composite nonwoven fabric having the reinforcing fabric inserted therein is subjected to padding treatment with an aqueous solution of PVA, followed by wet calendering, so that the nonwoven fabric constituting fibers are more uniformly packed between the constituent fibers of the reinforcing fabric and the weaving space, And the composite nonwoven fabric thus produced can be made into an artificial leather base material having a high density in the range of 0.24 to 0.45 g / cm < ³ > It becomes possible to make the filming to the extent possible.

Hereinafter, the present invention will be described in more detail with reference to Examples. The following examples illustrate the present invention, but the scope of the present invention is not limited to the following examples.

Example  One

80% by weight of ordinary nylon (PA) short fibers having a single filament size of 2de and a fiber length of 51 mm and 20% by weight of ordinary polyester (PET) short fibers having the same fineness and fiber length as those of the above- A nonwoven web was prepared according to the manufacturing method. Thereafter, a yarn with 17 yarns of polyamide (PA) filament yarns of 3 denier filament yarns is used in a lead-free form, and a reinforcing fabric having a weft density of 32 g / m ² , which is woven in plain weave of 50 warp yarns and 50 weft yarns And a needle punching process was performed under the conditions of a total needle density (PPSC) of 1,500 / Cm ² to prepare a low density composite nonwoven fabric sheet having a weight per unit area of about 150 g / m ² and a thickness of about 0.95 mm Respectively.

The composite nonwoven fabric sheet was immersed in a PVA aqueous solution of 3% by weight of a water-soluble PVA resin, taken out of the PVA resin solution, squeezed at a pickup ratio of about 100% using a mangle, and then sequentially Dried calendering, and wet calendering was carried out three times, and then passed through a triple calender heated at 170 ^° C to finally obtain an artificial leather having a weight per unit area of about 150 g / m ² and a thickness of about 0.5 mm A composite nonwoven fabric was prepared.

Thereafter, the composite nonwoven fabric was impregnated with an impregnation solution having a polyurethane concentration of 10% by weight according to a conventional processing method, and 20% by weight of a polyurethane coating solution was applied to the surface to coagulate the polyurethane in water, Finally, coated polyurethane artificial leather having a weight per unit area of about 360 g / m ² and a thickness of about 0.7 mm was produced.

Example  2

Unlike in Example 1, 24 yarns of polyamide (PA) filaments were stranded to form a reinforcing fabric, and yarns twisted at a twist number of 1,000T were used as warp yarns. The weft yarns were woven in a non-woven form and weighed 32g / m ² was used instead of the reinforcing fabrics made with high density composite non-woven fabric and artificial leather in the same manner as in example 1 except, this time, and finally per unit area of about 170g / m ² a thickness of about 0.6mm around the composite nonwoven fabric with a unit A coated polyurethane artificial leather having a weight per area of about 420 g / m ² and a thickness of about 0.9 mm was produced.

Comparative Example  One

In this comparative example, a reinforcing fabric was not used, and 30 wt% of ordinary nylon (PA) short fibers having a single filament fineness of 2de and a fiber length of 51 mm and a nonwoven fabric having the same fineness and heat shrinkage characteristics The same needle punching as in Example 1 was carried out by mixing and using 55% by weight of polyester (PET) staple fibers and 15% by weight of high shrinkage polyester (PET) staple fibers having a single filament size of 1.4 de and a fiber length of 51 mm After the nonwoven fabric sheet was prepared, the aqueous PVA solution of Example 1 was heated to 75 캜 to paddle the PVA resin, shrinkage of the high water content, and drying, without wet calendering of the present invention, A nonwoven fabric and a coated polyurethane artificial leather using the nonwoven fabric were prepared.

The general nonwoven fabric thus produced had a thickness of about 0.7 mm at a weight of about 150 g / m ² per unit area, and the artificial leather had a weight per unit area of about 400 g / m ² and a thickness of about 1.05 mm.

Comparative Example  2

For comparison with Example 2, this comparative example is a polyester (PET) having 65% by weight of ordinary nylon (PA) short fibers having a single filament size of 2 denier and a fiber length of 51 mm, a single yarn fineness of 1.4de, Density composite nonwoven fabric having a weight per unit area of about 220 g / m ² and a thickness of about 0.7 mm and a weight per unit area of about 480 g / m ² using the same method as in Comparative Example 1 except that 35 wt% Coated polyurethane artificial leather having a thickness of about 1.0 mm was prepared.

evaluation

The unit weight, the thickness, the apparent density, the tensile strength, the elongation, the tearing strength, and the like of the artificial leather were measured according to the ASTM method , The adhesive strength was measured according to the Nike method and the results are summarized in Table 1. On the other hand, the shape stability was recorded in comparison with the evaluations made by five experts in artificial leather after the evaluation by the tensile strength and elongation result reference and sensory methods respectively, and the adhesion jumping showing the uniformity of adhesion was measured The waveforms of the recorded graphs were recorded for reporting.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 part
Straight
artillery Weight (g / m ² ) 153 174 148 223  Thickness (mm) 0.49 0.62 0.73 0.68 Apparent density (g / cm ³ ) 0.312 0.281 0.203 0.328 sign
article
blood
Innovation Weight (g / m ² ) 365 417 402 478  Thickness (mm) 0.73 0.88 1.07 0.98 Apparent density (g / cm ³ ) 0.500 0.474 0.376 0.488  Tensile strength (Kg / inch) Bell 27.6 28.1 30.2 40.6 Transverse 34.3 36.9 20.3 30.8  Elongation (%) Bell 42.6 43.1 61.6 97.9 Transverse 59.7 61.6 115.3 148.7  Tear strength (Kg) Bell 3.5 4.5 3.0 5.3 Transverse 4.0 5.0 3.3 6.1  Adhesion strength (Kg / cm) 4.5 4.8 2.7 3.2  Morphological stability Very good Very good Inadequate Good  Adhesive jumping Very low Low greatness Low

As can be seen from Table 1, artificial leathers using the composite nonwoven fabric manufactured according to the embodiment of the present invention have similar strengths, lower strengths, and lower strengths, compared with artificial leathers using the general nonwoven fabrics and high density nonwoven fabrics of the comparative examples, The polyurethane artificial leather having a very stable shape stability due to the longitudinal to transverse elongation ratio and being able to be manufactured with relatively low weight and low thickness compared with artificial leather using general nonwoven fabric and high density nonwoven fabric, Able to know.

Particularly, in the case of artificial leather using the composite nonwoven fabric manufactured according to the present invention, since it exhibits excellent adhesive strength and adhesion uniformity as compared with artificial leather using a conventional nonwoven fabric, it is possible to provide a lightweight artificial leather material, It can be confirmed that it has different characteristics for use as a material of urethane synthetic leather.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (8)

A first step of binding a reinforcing fabric to an end face of the fibrous nonwoven fabric by needle punching to produce a low density composite nonwoven fabric sheet;
A second step of padding the produced low density composite nonwoven fabric sheet with a PVA aqueous solution;
A third step of calendering the padded composite nonwoven fabric sheet in a wet state using a calender composed of upper and lower steel rolls to increase densification; And
And a fourth step of heat treating the densified sheet at 150 to 180 ^° C. The composite nonwoven fabric according to claim 1, wherein the weight of the reinforcing fabric bound to the end face of the fibrous nonwoven fabric in the first step ranges from 15 to 30% by weight based on the weight of the low density composite nonwoven fabric sheet. Way. The method of claim 1, wherein the reinforcing fabric has a unit weight of 20 to 50 g / m ² . The method of claim 1, wherein the low density composite nonwoven fabric sheet produced in the first step has a weight per unit area of 100 to 180 g / m ² including a reinforcing fabric. The method for producing a composite nonwoven fabric for artificial leather according to claim 1, wherein the concentration of PVA in the aqueous PVA solution padded in the second step is 1 to 5% by weight. The method of claim 1, wherein the wet calendering in the third step is performed in two or three multi-steps. [7] The method of claim 6, wherein the moisture content of the nonwoven fabric after the final wetting calendering ranges from 0 to 5% by weight. A composite nonwoven fabric for artificial leather, produced by the method of claim 1, having an apparent fiber density of 0.24 to 0.45 g / cm ³ .