KR20110098675A

KR20110098675A - Artificial leather

Info

Publication number: KR20110098675A
Application number: KR1020110017147A
Authority: KR
Inventors: 박종호; 이응민; 황영남
Original assignee: 코오롱인더스트리 주식회사
Priority date: 2010-02-26
Filing date: 2011-02-25
Publication date: 2011-09-01
Also published as: WO2011105851A3; WO2011105851A2; JP5956351B2; EP2540909A2; JP2013520581A; EP2540909A4; EP2540909B1; KR101680533B1

Abstract

The present invention relates to an artificial leather that has a flame retardancy of the level required by the industry by applying the flame retardant composition on the preliminary artificial leather, and at the same time, the soft touch of the ultrafine fibers is not degraded and the breathability can be greatly improved. Artificial leather of the present invention, a pre-artificial leather comprising a nonwoven fabric made of ultrafine fibers and an elastic polymer resin impregnated in the nonwoven fabric; And a flame retardant composition layer formed by partially applying a flame retardant composition on the preliminary artificial leather at an area ratio of 60 to 90% of the total surface area of the preliminary artificial leather.

Description

Artificial leather {Artificial leather}

The present invention relates to artificial leather, and more particularly to artificial leather comprising a flame retardant composition layer.

Artificial leather is made by impregnating a polymer elastic body in a nonwoven fabric formed by interweaving microfibers three-dimensionally, and has a soft texture and a unique appearance similar to that of natural leather, thereby making shoes, clothing, gloves, sundries, furniture, and automobiles. It is widely used in various fields such as interior materials.

Such artificial leathers are required to have higher functionality in terms of flexibility, surface quality, wear resistance, light resistance, or elongation, depending on the intended use, and various properties may be required at the same time.

For example, when artificial leather is applied to the skin material attached to a car seat among automotive interior materials, as the eye level of the consumer increases, quality characteristics of the surface, specifically, excellent appearance, breathability, and tactile properties are required, There is a difficulty in satisfying the flame retardancy specified in the statutory items among the physical properties.

In other words, in order to impart flame retardancy required by the industry to artificial leather, a large amount of flame retardant must be used. Thus, when a large amount of flame retardant is treated to artificial leather, there is a problem that the touch of the artificial leather becomes hard and the breathability is lowered.

Therefore, the present invention relates to artificial leather that can prevent problems caused by the above limitations and disadvantages of the related art.

That is, the present invention is to provide an artificial leather that can be greatly improved breathability without deteriorating the soft touch of the ultrafine fibers and at the same time by the application of the flame retardant composition on the pre-artificial leather in part The purpose.

In order to achieve the above object, the present invention is a preliminary artificial leather including a nonwoven fabric made of ultrafine fibers and an elastic polymer resin impregnated in the nonwoven fabric; And a flame retardant composition layer formed by partially applying a flame retardant composition on the preliminary artificial leather at an area ratio of 60 to 90% of the total surface area of the preliminary artificial leather.

The present invention has the following effects.

First, the artificial leather according to the present invention has an effect of improving the economics as well as having a level of flame retardancy required in the industry by having a flame retardant composition layer partially applied in an optimum form and content.

Second, the artificial leather according to the present invention may have excellent touch and breathability as the flame retardant composition layer is partially applied.

Such artificial leather can be used for automobile seats that require excellent flame retardancy and appearance and feel.

1 is a plan view of an artificial leather according to an embodiment of the present invention.
2 is a cross-sectional view of the artificial leather along the AA 'line of FIG.
3 to 5 are plan views of artificial leather according to another embodiment of the present invention.

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 and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

As used herein, the term 'preliminary artificial leather' refers to artificial leather including a nonwoven fabric and an elastic polymer resin impregnated on the nonwoven fabric, and means an artificial leather immediately before a flame retardant composition is added.

Hereinafter, embodiments of the artificial leather of the present invention will be described in detail with reference to the accompanying drawings.

1 is a plan view of an artificial leather according to an embodiment of the present invention.

2 is a cross-sectional view of the artificial leather along the AA ′ line of FIG. 1.

1 and 2, the artificial leather of the present invention includes a preliminary artificial leather 30 and a flame retardant composition layer 10 formed by partially applying a flame retardant composition thereon. According to one embodiment of the invention illustrated in FIGS. 1 and 2, since the flame retardant composition is only partially applied onto the preliminary artificial leather 30, it corresponds to the uncoated area of the preliminary artificial leather to which the flame retardant composition is not applied. A groove is formed, and as a result, the artificial leather of the present invention can have excellent breathability without deteriorating the feel of the preliminary artificial leather made of ultrafine fibers.

In addition, since the flame retardant composition is only partially applied on the preliminary artificial leather 30, the amount of the flame retardant composition can be greatly reduced. As a result, the economical efficiency can be improved by lowering the production cost of artificial leather.

On the other hand, when the flame-retardant composition is completely coated on the preliminary artificial leather 30 as in the prior art, there is a problem in that the economical efficiency is lowered and the feel and breathability of the artificial leather decreases as the flame-retardant composition is used in large quantities.

The artificial leather of the present invention has a flame retardant composition layer 10 formed by partially applying a flame retardant composition at an area ratio of 60 to 90% of the total surface area of the preliminary artificial leather 30. If the area ratio of the flame retardant composition layer 10 is less than 60%, artificial leather having a level of flame retardancy required by the industry cannot be obtained, while the area ratio of the flame retardant composition layer 10 may exceed 90%. In this case, the breathability of artificial leather may drop sharply.

The flame retardant composition layer 10 may have various forms, as shown in FIGS. 1 and 3 to 5.

For example, as shown in FIG. 5, the flame retardant composition layer 10 may be composed of a plurality of discrete unit layers having a predetermined shape. That is, a plurality of unit layers constituting the flame retardant composition layer 10 are discontinuously distributed on the preliminary artificial leather 30, and one groove 20 corresponding to the non-coated region of the preliminary artificial leather 30 is formed. It may be formed to surround the plurality of unit layers.

However, when one groove 20 is formed surrounding a plurality of discontinuously distributed unit layers, the uncoated region of the preliminary artificial leather 30 may easily burn along the continuously formed grooves 20. Because of this, the flame retardancy of artificial leather may be somewhat reduced. As a result, relatively many flame retardants must be used to impart the level of flame retardancy required in the industry to the artificial leather, and thus, the breathability and feel of the artificial leather may be slightly lowered.

On the contrary, as illustrated in FIGS. 1, 3 and 4, respectively, the artificial leather of the present invention has a plurality of discontinuously distributed corresponding to the uncoated regions of the preliminary artificial leather 30 to which the flame retardant composition is not applied. It may have grooves 20.

The flame retardant composition layer 10 of the present invention may be one body surrounding the plurality of grooves 20 as illustrated in FIGS. 1 and 3. Optionally, as illustrated in FIG. 4, the flame retardant composition layer 10 of the present invention may be composed of a plurality of unit layers discontinuously distributed.

When the flame retardancy test is performed on an artificial leather having a plurality of grooves 20 discontinuously distributed corresponding to the non-coated areas of the preliminary artificial leather 30 to which the flame retardant composition is not applied, the plurality of grooves 20 ) Can be prevented from spreading the flame over the entire non-coated area of the preliminary artificial leather 30 because it is discontinuously distributed. As a result, even if the application amount of the flame retardant composition is reduced, the flame retardancy of artificial leather can be greatly improved.

Therefore, when the same amount of flame retardant composition is applied to the preliminary artificial leather 30, artificial leather having a plurality of grooves 20 discontinuously distributed, artificial leather having only one groove 20 continuously formed Compared with the excellent flame retardancy.

The plurality of grooves 20 of the artificial leather of the present invention may be distributed irregularly and discontinuously, as shown in FIG. 6, and the flame retardant composition layer 10 surrounds the plurality of grooves 20. It may be the body of.

Each of the plurality of grooves 20 of the artificial leather of the present invention may have a variety of shapes, for example circular, polygonal or line shape.

On the other hand, in order to improve both flame retardancy and breathability, the flame retardant composition layer 10 should have an optimum penetration depth and upper thickness. 2 is a cross-sectional view of the artificial leather according to the line AA ′ of FIG. 1, which is an embodiment of the present invention. As shown in FIG. 2, the artificial leather has a flame retardant composition layer 10 of the preliminary artificial leather 30. It has an upper thickness, which means the degree derived above the surface, and a penetration depth, which means the degree of penetration of the flame retardant composition layer 10 into the preliminary artificial leather 30.

In order to produce an artificial leather having a horizontal combustion rate of 100 mm / min or less flame retardancy and a breathability of 20 to 50 L / min / 100 cm 2, the upper thickness a is the thickness c of the preliminary artificial leather 30. It is preferably in the range of 0.1 to 4% of the ratio. If the ratio of the upper thickness (a) is less than 0.1%, it is impossible to manufacture artificial leather having the level of flame retardancy required by the industry, whereas if the ratio of the upper thickness (a) exceeds 4%, the artificial leather The touch may drop sharply.

The penetration depth (b) may be preferably in the range of 5 to 50% of the thickness (c) of the preliminary artificial leather (30). If the ratio of the penetration depth (b) is less than 5%, the adhesive strength is lowered and durability is reduced, while if the ratio of the penetration depth (b) exceeds 50%, the touch of artificial leather may be hard.

The top thickness (a) and depth of penetration (b) of the flame retardant composition layer 10 can be measured by imaging the cross section of the sample with a scanning electron microscope (SEM).

The flame retardant composition may comprise a flame retardant and a binder. As the flame retardant, it may be preferable to use a phosphorus flame retardant rather than a halogen flame retardant which is a carcinogen. The binder is for improving the adhesive force, and various kinds of binders may be used as the binder. In particular, since the urethane-based binder including silicon is excellent in heat resistance, the decomposition of silicon is suppressed during combustion and crosslinking with urethane can be formed, thereby improving the flame resistance of artificial leather. On the other hand, the urethane-based binder not only has a strong adhesive strength with the preliminary artificial leather 30, but also has the advantage of having a good adhesive strength with other materials such as sponge.

The flame retardant composition may include various additives in addition to the flame retardant and binder described above. As the additive, an antioxidant, an antistatic agent, an ultraviolet absorber, a hydrolysis inhibitor, a softening agent, or the like may be used.

The preliminary artificial leather 30, as defined above, means an artificial leather including a nonwoven fabric (not shown) and an elastic polymer resin (not shown) impregnated in the nonwoven fabric and immediately before a flame retardant composition is added. , By the method described below.

First, a sea island type fiber is manufactured through a composite spinning process. The island-in-the-sea fiber component may be nylon or polyester, and the polyester may be polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), or polybutylene terephthalate (PBT).

Subsequently, the island-in-the-sea fibers are cut into short fibers such as staple fibers through a cutting process. The island-in-the-sea fibers in the form of short fibers undergo a carding process and a cross lapping process to form a web. Alternatively, a spun bonding process may be used to form a web directly without a cutting process using island-in-the-sea fibers in the form of long fibers.

The plurality of webs thus formed are bonded to each other using a needle punch or a water jet punch to complete a nonwoven fabric.

Subsequently, the preliminary artificial leather 30 is completed by sequentially performing the step of impregnating the elastic polymer resin in the nonwoven fabric and the step of minimizing the sea component in the island-in-the-sea fibers. Optionally, the ultrafine process may be performed first, followed by the impregnation process of the elastic polymer resin.

The process of impregnating the elastic polymer resin in the nonwoven fabric may be performed by a coating process or a dipping process. Among these, a simple and easy dipping process will be described below.

First, a polyurethane resin or a silicone resin may be used as the elastic polymer resin. As the polyurethane resin, polycarbonate diol resin, polyester diol resin or polyetherdiol resin alone or a mixture thereof may be used.

The impregnation process of the elastic polymer resin may be completed by sequentially performing a step of immersing the nonwoven fabric in the composition including the elastic polymer resin, a solidification process of solidifying the elastic polymer resin in a coagulation bath, and a process of washing with water in a washing tank. . The coagulation solution contained in the coagulation bath may be a mixed solution containing water and dimethylformamide.

In more detail, the ultrafine process is performed by using an alkaline solution such as an aqueous caustic soda solution to elute and remove the sea component from the composite fiber composed of the island component and the sea component. As the sea component is removed, the remaining island components form microfibers. The microfibers produced by the micronization process may have a fineness of 0.3 denier or less in terms of touch.

In the above, the method for manufacturing the preliminary artificial leather 30 using the island-in-the-sea fiber was described. However, the present invention is not limited thereto, and the microfiber is manufactured from the beginning and the nonwoven fabric is manufactured using the same. The preliminary artificial leather 30 may be manufactured by impregnating an elastic polymer resin.

Artificial leather as described above has excellent flame retardancy and excellent breathability at the same time. That is, the horizontal combustion speed of artificial leather measured in accordance with the automotive interior combustion test regulation of FMVSS.No.302 is 100 mm / min or less, and at the same time, the breathability of artificial leather is in the range of 20 to 50 L / min / 100 cm2. Can be.

The horizontal combustion speed is a method of measuring flame retardancy mainly when artificial leather is used as interior materials such as automobile seats. If the horizontal burning rate of artificial leather exceeds 100 mm / min, it may be difficult to use as interior materials for automobiles because it may not have the level of flame retardancy required by the industry.

The breathability of the artificial leather indicates the degree of passage of air into and out of the car seat when the artificial leather is used in the car seat. As the breathability increases, the driver feels comfortable, while the breathability decreases, the driver feels uncomfortable. However, if the breathability is excessively increased, as the content of the flame retardant composition layer 10 falls, the flame retardancy of artificial leather is excessively degraded. Therefore, it may be preferable that the breathability of the artificial leather has a range of 20 ~ 50 L / min / 100 cm 2.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. The present invention is only to aid the understanding by the following examples, and is not intended to limit the protection scope of the claims.

Example 1

A molten solution of a sea component is prepared by melting a copolymerized polyester obtained by copolymerizing 5 mol% of a polyester unit containing a metal sulfonate in a polyethylene terephthalate, which is a main component, and melting polyethylene terephthalate (PET). Prepare a melt of the components. Thereafter, using a 50% by weight of the molten solution of the sea component and 50% by weight of the melt of the island component composite spinning to obtain a filament consisting of three denier single yarn and 16 island components in cross section, the filament at a draw ratio of 3.5 After stretching to prepare a island-in-the-sea filament-shaped fibers. Thereafter, the crimp process was performed to have a crimp number of 15 pieces / inch using the island-in-the-sea fibers, heat-set at 130 ° C., and cut into 51 mm to prepare an island-in-the-sea-type fiber in staple form.

Then, after forming the web through the carding process and the cross-lapping process of the island-in-the-sea fibers in the form of staples, the webs were subjected to a needle punch process to prepare a nonwoven fabric.

Thereafter, the nonwoven fabric was padded with an aqueous polyvinyl alcohol solution having a concentration of 5% by weight, followed by drying. The dried nonwoven fabric was obtained by dissolving the polyurethane in a dimethylformamide (DMF) solvent. Immerse in solution for 3 minutes. Thereafter, the nonwoven fabric impregnated with the polyurethane solution was coagulated in an aqueous dimethylformamide solution at a concentration of 15% by weight and washed with water to obtain a nonwoven fabric impregnated with polyurethane.

Subsequently, the polyurethane-impregnated nonwoven fabric was treated with an aqueous solution of caustic soda at a concentration of 5% by weight to elute the sea component in the composite fiber to perform an ultra-fine process to obtain a unit weight of 346.3 g / m 2, a thickness of 0.95 mm, A preliminary artificial leather (30) having a breathability of 56.4 L / min / 100 cm 2 was obtained.

Next, using a rotary screen coating method, a flame-retardant composition having a viscosity of 7,800 cps blended with 40 wt% water, 40 wt% ammonium polyphosphate phosphorus flame retardant, and 20 wt% polyurethane binder was used. On one surface of the preliminary artificial leather 30, by coating in the shape as shown in Figure 1 and hot-air dried at 130 ℃ for 10 minutes, the area ratio 65%, upper thickness (a) 16㎛, and penetration depth (b) An artificial leather having a flame retardant composition layer 10 having a thickness of 100 μm was obtained. The rotary screen coating was performed using a rotary screen printing machine of Ishinose Co., Ltd. and an 80 mesh screen of STORK Co., Ltd.

Examples 2 and 3

In Example 1 described above, artificial leathers were obtained in the same manner as in Example 1, except that the area ratios of the flame retardant composition layer 10 were changed to 75 and 85%, respectively.

Example 4

In Example 1 described above, artificial leather was obtained in the same manner as in Example 1 except that the flame-retardant composition was applied in the shape as shown in FIG. 4.

Examples 5 and 6

In Example 4 described above, artificial leather was obtained in the same manner as in Example 4, except that the area ratio of the flame retardant composition layer 10 was changed to 75 and 85%, respectively.

Example 7

In Example 1 described above, artificial leather was obtained in the same manner as in Example 1 except that the flame-retardant composition was applied in the shape as shown in FIG. 5.

Comparative Example 1

In Example 1 described above, artificial leather was obtained in the same manner as in Example 1 except that the flame-retardant composition was applied to the entire surface of the preliminary artificial leather 30.

Comparative Example 2

In Example 1 described above, artificial leather was obtained in the same manner as in Example 1 except that the area ratio of the flame retardant composition layer 10 was changed to 55%.

Next, the physical properties of artificial leather obtained by the above examples and comparative examples, respectively, were measured by the following method, and the measurement results are shown in Table 1 below.

% Of area of flame retardant composition layer 10

The area ratio (%) of the flame retardant composition layer 10 represents the area occupied by the flame retardant composition layer 10 formed on the preliminary artificial leather 30 relative to the total surface area of the preliminary artificial leather 30.

Specifically, a sample having a size of 50 × 50 cm is selected by selecting an arbitrary point of artificial leather, and a sample prepared by using an image analyzer (using the JVC Digital Camera KY-F70B in the software of Image-Pro Plus) After photographing the surface, the area ratio of the flame retardant composition layer 10 was measured by the following equation through an area analysis program. At this time, a total of five samples were used, and the area ratio of the flame retardant composition layer 10 was finally obtained by arithmetically averaging each measured result.

[Equation]

Area ratio (%) of the flame retardant composition layer 10 = (area of the flame retardant composition layer 10 applied to the preliminary artificial leather 30 / area of the preliminary artificial leather 30) × 100

% Of upper thickness of flame retardant composition layer 10

As shown in FIG. 2, the upper thickness ratio (%) of the flame retardant composition layer 10 is a flame retardant composition derived upward from the surface of the preliminary artificial leather 30, relative to the average thickness c of the preliminary artificial leather 30. The upper thickness a, which is the average height to the layer 10, is shown as a ratio. The average thickness c of the preliminary artificial leather 30 and the upper thickness a of the average height up to the flame retardant composition layer 10 were measured using a scanning electron microscope (SEM).

Specifically, any two points are selected so that the interval is 1000 μm in the cross-sectional SEM photograph of the artificial leather, and the thickness c of the preliminary artificial leather 30 and the top of the flame retardant composition layer 10 at the two points. The thickness a was obtained. The measurement was performed on a total of five samples, and the arithmetic mean of the measured results was finally obtained to obtain the average thickness (c) of the preliminary artificial leather (30) and the average top thickness (a) of the flame retardant composition layer (10). . Subsequently, the upper thickness ratio (%) of the flame retardant composition layer 10 was calculated using the average thickness c of the preliminary artificial leather 30 and the average upper thickness a of the flame retardant composition layer 10.

% Penetration depth of flame retardant composition layer 10

The penetration depth (b) ratio (%) of the flame retardant composition layer 10 is from the surface of the preliminary artificial leather 30 to the inside, as compared to the average thickness c of the preliminary artificial leather 30, as shown in FIG. The penetration depth (b), which is the average depth to the penetrated flame retardant composition layer 10, is shown as a ratio. The average thickness (c) of the preliminary artificial leather 30 and the depth of penetration (b), which is the average depth to the flame retardant composition layer 10, were measured using a scanning electron microscope (SEM).

Specifically, any two points are selected so that the interval is 1000 μm in the cross-sectional SEM image of the artificial leather, and the thickness (c) of the preliminary artificial leather 30 and the penetration of the flame retardant composition layer 10 at the two points. Depth b was obtained. The measurement was performed on a total of five samples, and the arithmetic mean of the measured results was finally obtained to obtain the average thickness (c) of the preliminary artificial leather (30) and the average penetration depth (b) of the flame retardant composition layer (10). . Then, the penetration depth ratio (%) of the flame retardant composition layer 10 was calculated using the average thickness c of the preliminary artificial leather 30 and the average penetration depth b of the flame retardant composition layer 10.

Application amount measurement of the flame retardant composition layer 10

The application amount (g / m 2) of the flame retardant composition was obtained from the difference between the weight of the preliminary artificial leather 30 before the flame retardant composition layer 10 was formed and the weight of artificial leather after the flame retardant composition layer 10 was formed.

Horizontal burning rate measurement of artificial leather

The horizontal combustion speed (mm / min), which indirectly indicates the degree of flame retardancy of artificial leather, was measured according to the automotive interior combustion test regulations of FMVSS.

Breathability Measurement of Artificial Leather

Breathability (L / min / 100 cm 2) was measured according to the Frazier test specified in ASTM D 737.

division Groove shape in artificial leather area
ratio
(%) Upper thickness
ratio(%) Penetration depth
ratio(%) Application amount
(g / ㎡) Horizontal combustion
speed
(Mm / min) Breathable
(L / min / 100㎠) Example 1 Discrete circles 65 1.7 10.5 35.7 Self-extinguishing 44 Example 2 Discrete circles 75 1.7 10.5 44.5 Self-extinguishing 37 Example 3 Discrete circles 85 1.7 10.5 49.8 Self-extinguishing 33 Example 4 Discontinuous lines 65 1.7 10.5 38.1 Self-extinguishing 46 Example 5 Discontinuous lines 75 1.7 10.5 43.1 Self-extinguishing 37 Example 6 Discontinuous lines 85 1.7 10.5 51.1 Self-extinguishing 34 Example 7 One groove enclosing a number of discrete circular application areas 65 1.7 10.5 33.7 99 46 Comparative Example 1 No groove present due to front application of flame retardant composition 100 1.7 10.5 60.6 Self-extinguishing 15 Comparative Example 2 Discrete circles 55 1.7 10.5 30.6 141 49

10: flame retardant composition layer 20: groove
30: preliminary artificial leather

Claims

A preliminary artificial leather comprising a nonwoven fabric made of ultrafine fibers and an elastic polymer resin impregnated in the nonwoven fabric; And
An artificial leather comprising a flame retardant composition layer formed by partially applying a flame retardant composition on the preliminary artificial leather at an area ratio of 60 to 90% of the total surface area of the preliminary artificial leather.

The method of claim 1,
And wherein said artificial leather has a plurality of grooves discontinuously distributed corresponding to uncoated areas of said preliminary artificial leather to which said flame retardant composition is not applied.

The method of claim 2,
And the flame retardant composition layer is one body surrounding the grooves.

The method of claim 2,
Each of the grooves is artificial leather, characterized in that the circular or polygonal shape.

The method of claim 1,
The horizontal combustion speed of the artificial leather measured according to the FMVSS. Artificial leather

The method of claim 1,
The flame retardant composition layer is artificial leather, characterized in that it has an upper thickness of 0.1 ~ 4% range compared to the thickness of the preliminary artificial leather and a penetration depth of 5 ~ 50% range of the thickness of the preliminary artificial leather.

The method of claim 1,
The flame retardant composition layer is artificial leather comprising a phosphorus-based flame retardant.

The method of claim 1,
The flame retardant composition layer is artificial leather including a urethane-based binder containing silicon.

The method of claim 1,
Fineness of the ultrafine fibers is artificial leather, characterized in that less than 0.3 denier.