KR101680535B1 - Artificial Leather Having Improved Light Fastness and Method for Manufacturing The Same - Google Patents

Abstract

Disclosed is an artificial leather having improved light fastness as well as reducing the amount of dye used in dyeing, and a method for producing the same. The artificial leather of the present invention comprises a nonwoven fabric made of microfine fibers having a monofilament fineness of 0.001 to 3 denier and an elastic polymer impregnated into the nonwoven fabric; And a pigment layer formed by applying a pigment solution on the preliminary artificial leather, wherein the nonwoven fabric is dyed with a saline solution containing a disperse dye.

Description

Technical Field [0001] The present invention relates to an artificial leather having improved light fastness and a method of manufacturing the artificial leather.

TECHNICAL FIELD The present invention relates to an artificial leather, and more particularly, to an artificial leather having an improved lightfastness as well as a reduction in the amount of dye used in dyeing.

Artificial leather is made by impregnating a nonwoven fabric formed by three-dimensionally entangled microfine fibers into a polymer elastomer, and has a soft texture and a unique appearance similar to natural leather, and is used for shoes, clothes, gloves, And the like.

Such artificial leathers require a relatively large amount of dye consumption compared to other types of fibers in order to be dyed to have a certain apparent density due to an increase in the fiber surface area due to the use of microfine fibers.

Among the high functionality required for artificial leather, there is light resistance. Light resistance is particularly required for artificial leather used as an automobile interior material because artificial leather for automobile interior materials is exposed to sunlight for a long time and is likely to be discolored as compared with general dyed materials.

Therefore, it is required to develop an artificial leather dyeing method which can reduce the amount of dye used compared to artificial leather in which existing microfine fibers are used and has a high level of light fastness.

Accordingly, the present invention is directed to an artificial leather and a method of manufacturing the artificial leather which can prevent problems due to limitations and disadvantages of the related art.

One aspect of the present invention is to provide an artificial leather which not only can reduce the amount of dye used in dyeing but also has improved light resistance.

Another aspect of the present invention is to provide a method for producing an artificial leather which not only can reduce the amount of dye used in dyeing but also has improved light resistance.

Other features and advantages of the invention will be set forth in the description which follows, or may be learned by those skilled in the art from the description.

According to one aspect of the present invention, there is provided a preliminary artificial leather comprising a nonwoven fabric made of microfine fibers having a monofilament fineness of 0.001 to 3 denier and an elastic polymer impregnated in the nonwoven fabric; And a pigment layer formed by applying a pigment solution on the preliminary artificial leather, wherein the nonwoven fabric is dyed with a salt solution containing a disperse dye.

According to another aspect of the present invention, there is provided a method of manufacturing a nonwoven fabric, Impregnating the nonwoven fabric with an elastic polymer; Fabricating the preliminary artificial leather by making the nonwoven fabric finer so as to have a single yarn fineness of 0.001 to 3 denier; Applying a pigment solution on the preliminary artificial leather to form a pigment layer; And dyeing the preliminary artificial leather on which the pigment layer is formed with a salt solution containing a disperse dye.

The foregoing general description of the present invention is intended to be illustrative of or explaining the present invention, but does not limit the scope of the present invention.

When the artificial leather of the present invention is used as an automobile interior material requiring high light resistance, it exhibits a lower discoloration degree even when exposed to sunlight for a long time, as compared with artificial leather dyed by a general method.

In addition, when the artificial leather is produced by the method of the present invention, the amount of the dye to be used can be reduced compared with the conventional method, thereby reducing the manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a cross-sectional view illustrating an artificial leather according to an embodiment of the present invention,
2 is a flowchart illustrating a method of manufacturing an artificial leather according to an 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 " means an artificial leather including a nonwoven fabric and an elastic polymer resin impregnated in the nonwoven fabric, and means an artificial leather immediately before the pigment layer is coated.

Hereinafter, an artificial leather according to the present invention and a manufacturing method thereof will be described in detail with reference to the accompanying drawings.

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

As shown in FIG. 1, the artificial leather 100 of the present invention includes a nonwoven fabric and a preliminary artificial leather 110 including an elastic polymer impregnated in the nonwoven fabric. The pigment layer 120 is formed by applying a pigment solution on the preliminary artificial leather 110. The nonwoven fabric of the preliminary artificial leather (100) is made of ultrafine fibers having a single fiber fineness of 0.001 to 3 denier and is dyed with a salt solution containing a disperse dye.

Hereinafter, a method of manufacturing the preliminary artificial leather 110 will be described with reference to FIG.

First, a nonwoven fabric made of ultrafine fibers having a single fiber fineness of 0.001 to 3 deniers is prepared by the following method (S10).

(Sea-island) type fibers are produced through a combined spinning process. The components of the sea-island type fibers include nylon, polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polytetraethylene terephthalate, polyoxyethylene benzoate, Polyacrylic, polyvinyl alcohol, acetate, or the like.

Next, the sea-island fibers are formed into a short fiber shape such as staple fibers through a cutting process. The sea-island fibers in the form of short fibers are subjected to a carding process and a cross lapping process to form a web. Alternatively, a web may be formed directly by a spun bonding process using a sea-island fiber in the form of a long fiber without a cutting process.

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

Next, the preliminary artificial leather 110 is completed by sequentially performing the step (S20) of impregnating the nonwoven fabric with the elastic polymer and the microfabricating step (S30) of removing the sea component from the sea-island fibers. Alternatively, the microfabricating step (S30) may be performed first and then the step (S20) of impregnating the elastic polymer resin may be performed.

The step (S20) of impregnating the nonwoven fabric with the elastic polymer may be performed by a coating process or a dipping process. Among these processes, a simple and easy dipping process will be described in detail as follows .

First, a polyurethane resin or a silicone resin may be used as the elastic polymer impregnated in the nonwoven fabric. As the polyurethane resin, a polycarbonate diol resin, a polyester diol resin or a polyether diol resin alone or a mixture thereof may be used.

The step of immersing the nonwoven fabric in the composition containing such an elastic polymer, the coagulating step of solidifying the elastic polymer resin in the coagulating bath, and the washing step in the water bath are sequentially performed to complete the step (S20) of impregnating the elastic polymer resin . The coagulating solution contained in the coagulation bath may be a mixed solution containing water and dimethylformamide.

The microfabrication process (S30) will be described in more detail. Using the alkali solution such as caustic soda aqueous solution, the marine component is eluted and removed from the conjugate fiber composed of the combustible component and the combustible component. By removing the sea component, the residual islands become microfine fibers. The microfine fibers produced by the microfabricating step (S30) are preferably those having a monofilament fineness of 0.001 to 3 denier from the viewpoints of dyeability and tactility.

Although the method for producing the preliminary artificial leather 110 using the sea-island fibers has been described above, the present invention is not limited to this. The present invention can be applied to the production of microfibers from the beginning, The preliminary artificial leather 110 may be produced by impregnating the elastic polymer.

The preliminary artificial leather 110 according to an embodiment of the present invention includes 60 to 80% by weight of the microfine fiber nonwoven fabric and 20 to 40% by weight of the elastic polymer.

A pre-buffing process is performed on the preliminary artificial leather fabricated as described above (S40).

Subsequently, in order to reduce the amount of dye used in dyeing and impart excellent light fastness to the artificial leather, a pigment solution containing a pigment of a color similar to the color to be dyed is applied on the pre-buffed preliminary artificial leather (110) A layer 120 is formed (S50).

As described above, the present invention is characterized in that the pigment is applied to the surface of the preliminary artificial leather (110) using a binder as a medium to develop color. The pigment solution of the present invention includes a pigment, a binder and a solvent.

The pigment may be an inorganic pigment or an organic pigment. For example, the pigments used in the coating may be formulated to match the color to be dyed with one or more pigments selected from carbon black, yellow pigments, red pigments, blue pigments, and green pigments. The concentration of the pigment is suitably 0.01 to 20% by weight based on the pigment solution.

As the binder, an aqueous polyurethane or an oily polyurethane can be used.

Examples of the method for coating the pigment solution include a gravure roller coating, a knife coating, and a coating method using a fader.

The pigment solution is coated on the preliminary artificial leather 110 and the preliminary artificial leather 110 coated with the pigment solution is dried at 100 to 140 ° C for 5 to 10 minutes to remove the solvent and complete the formation of the pigment layer 120 . If the drying temperature is too high or the drying time is too long, aging of the polyurethane binder occurs. Conversely, if the drying temperature is too low or if the drying time is too short, there is a problem that the solvent is not completely removed or the process efficiency is lowered.

On the other hand, during subsequent dyeing and buffing processes, the pigment layer 120 may be partially separated from the preliminary artificial leather 110, which may cause a color difference between the separated and non-separated portions of the pigment layer 120 cause.

Accordingly, as illustrated in FIG. 1, the pigment layer 120 must penetrate the interior of the preliminary artificial leather 110 to a certain extent. That is, the pigment layer 120 of the present invention has an upper thickness a, which means a degree of protrusion on the upper surface of the preliminary artificial leather 110, and a penetration depth, which means a degree of penetration into the interior of the preliminary artificial leather 110 (b).

According to one embodiment of the present invention, the pigment layer 120 has an upper thickness a of 0.1 to 3% and a penetration depth b of 1 to 20%, relative to the thickness c of the preliminary artificial leather 110, .

If the ratio of the upper thickness a of the pigment layer 120 is less than 0.1%, the pigment layer 120 may not be formed properly or the pigment layer 120 may be easily separated by friction, If the ratio exceeds 3%, the surface texture of the artificial leather (100) may drop sharply.

On the other hand, when the penetration depth (b) of the pigment layer 120 is less than 1%, the pigment layer 120 easily separates from the preliminary artificial leather 110 and the pigment layer 120 is not permeated There is a risk of dichromatism occurring when the area is exposed. On the contrary, when the penetration depth (b) ratio exceeds 20%, the feel of the artificial leather can be hardened.

The ratio of the upper thickness (a) of the pigment layer 120 and the penetration depth (b) ratio are measured as follows.

The ratio (%) of the upper layer thickness (a) of the pigment layer 120 is an average of the average thickness (c) of the preliminary artificial leather layer 30 to the pigment layer 120 drawn upward from the upper surface of the preliminary artificial leather layer 110 And the penetration depth b of the pigment layer 120 is the ratio of the average thickness c of the synthetic leather 30 to the inner surface of the preliminary artificial leather 30 Is the ratio of penetration depth (b), which is the average depth to the penetrated pigment coating layer (10). The average thickness c of the preliminary artificial leather 110, the upper thickness a of the pigment layer 120 and the penetration depth b of the pigment layer 120 are measured using a scanning electron microscope (SEM).

Specifically, arbitrary two points are selected so that the interval is 1000 탆 in the cross-sectional SEM photograph of the artificial leather 100, the thickness c of the preliminary artificial leather 110 at the two points, the thickness c of the pigment layer 120, (A) and the penetration depth (b) of the pigment layer 120, respectively. These measurements are performed on five samples in total and the measured results are arithmetically averaged to finally determine the average thickness c of the preliminary artificial leather 110, the average upper thickness a of the pigment layer 120, The penetration depth b of the layer 120 is obtained. Next, the upper thickness ratio (%) of the pigment layer 120 is calculated using the average thickness c of the preliminary artificial leather 110 and the average upper thickness a of the pigment layer 120, The penetration depth ratio (%) of the pigment layer 120 is calculated using the average thickness c of the pigment layer 120 and the average penetration depth b of the pigment layer 120.

After the pigment layer 120 is formed as described above, the preliminary artificial leather 110 formed with the pigment layer 120 is dyed with a salt solution containing disperse dye (S60).

Since the artificial leather of the present invention used as a vehicle interior material requires high light resistance, the disperse dye contained in the saline solution of the present invention is preferably a non-azo disperse dye. Anthraquinone disperse dyes such as Disperse Blue 56, condensate disperse dyes, C.I. Disperse Yellow 54, C.I., Disperse Yellow 64, C.I. Coumarin disperse dyes such as Disperse Yellow 82, and C.I. Disperse Yellow 58, and the like.

In order to improve the light resistance of the artificial leather (100), the salt solution of the present invention may further contain 4 to 10% (o.w.f.) of triazine derivatives as a UV-absorber. Specifically, the UV-absorber is dispersed in a salt solution containing a disperse dye, and then a dyeing process is performed at 100 to 135 캜, preferably 110 to 130 캜. The saline solution of the present invention may further contain a polyalkylene oxide adduct of an alkylnaphthalene-based or polyhydric alcohol fatty acid ester such as? -Naphthalenesulfonic acid formaldehyde condensate as a dispersant and sulfur oxides thereof.

The dyeing time is preferably from 20 to 60 minutes in terms of deterioration of the polyurethane elastic body and cost. At this time, it is preferable to adjust the pH of the salt solution with a pH adjusting agent such as acetic acid so that the pH of the salt solution becomes 4 to 5.

After completion of the dyeing step (S60), reduction washing is carried out under general reducing washing conditions, pH is neutralized in the acidic aqueous solution, and dried (S70).

After the dyeing step (S70), a buffing step for raising is performed (S80).

In the case of the artificial leather (100) of the present invention manufactured by the above method, the L value measured by the colorimeter is 70 or less and the light fastness evaluation standard MS 300-32 4.14.1 (tester: ATLAS Ci -4000 weather-O-meter, black panel temperature: 89 ° C ± 3 ° C, light quantity: 66W / m2, irradiation volume: 84MJ / m2, bath humidity: 50% ± 5% RH) 3 or more, and has a value of 9 or less when the degree of abrasion of an artificial leather is measured using KS K 0591), which has a wear resistance of at least 4, measured according to ISO 12947-2: 1998 (E).

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. It should be noted, however, that the following examples are intended to assist the understanding of the present invention and should not limit the scope of the present invention.

Example 1

A preliminary artificial leather impregnated with a 30 wt% polyurethane elastomer was impregnated in a nonwoven fabric made of polyester microfine fibers having a single yarn fineness of 0.15 denier and subjected to a pre-buffing process, and then the pigment solution was applied on a preliminary artificial leather under the following conditions And then stained. After drying, a final-buffing process was performed to produce an artificial leather.

<Coating Conditions>

Pigment solution composition: water-dispersed polyurethane resin 5 wt% + red pigment 4.5 wt% + water 90.5 wt%

Coating apparatus and conditions:

- Laboratory Gravure Coater (Ilsung Machine)

- Rollers 80mesh

- knife angle: 40 degrees

- When the knife is attached to the gravure roller, the air pressure is 1.2kgf

- Operation speed: 7m / min

- Drying temperature and time: 120 캜, 10 min

<Conditions for dyeing>

- Dye: Red disperse dye (anthraquinone type) 5% (o.w.f.)

UV-Absorbent: UV-Fast P (triazine derivative) 6% (o.w.f.)

- Dispersant: nonionic fatty acid ester 1 g / l

- Acetic acid: 1 g / l

- Bathroom: 1:30

- Dyeing temperature and time: 120 占 폚, 60 minutes

After completion of the dyeing, the dyeing residue was discharged from the dyeing machine, water was again supplied to the dyeing machine, and then water was added to the dyeing solution at 80 DEG C for 20 minutes under ordinary reducing washing conditions (hydrogens: 4 g / l, caustic soda: 2 g / , Washed with an acidic aqueous solution under the following conditions, and then dried at 130 DEG C for 10 minutes to prepare an artificial leather dyeing product. The pigment layer had an upper thickness of 0.51% of the thickness of the preliminary artificial leather and an infiltration depth of 8.54%.

<Cleaning Conditions>

Acetic acid 0.5 g / l

Waste: 1:30

Cleaning temperature: 80 ° C × 20 minutes

Examples 2 to 4

An artificial leather dyed product was produced under the same process and conditions as in Example 1, except that the pigment and disperse dye of Example 1 were changed as shown in Table 2. The ratio of the upper layer thickness and penetration depth of the pigment layer to the thickness of the preliminary artificial leather is shown in Table 2 below.

Examples 5 to 12

Artificial leather dyes were produced under the same conditions and conditions as in Example 1, except that the roller coating, air pressure, and running speed were changed as shown in Table 1, among the pigment coating conditions of Example 1 described above. The ratio of the upper layer thickness and penetration depth of the pigment layer to the thickness of the preliminary artificial leather is shown in Table 2 below.

division Roller mesh Air pressure (kgf) Operation speed (m / min) Example 5 80 2.3 7 Example 6 80 1.0 7 Example 7 60 2.5 5.5 Example 8 80 0.8 8.5 Example 9 80 2.8 7 Example 10 60 0.8 8.5 Example 11 80 0.8 10 Example 12 60 3.2 5.5

Comparative Examples 1 to 4

The pigment coating of Example 1 was not performed, and the artificial leather dyes were prepared according to the same process and conditions as in Example 1, except that the disperse dye used in dyeing was changed as shown in Table 2 below.

division In the pigment solution
Pigment and usage Disperse dyes and usage in saline Upper thickness
(a) Penetration depth
(b) Example 1 Red, 4.5 wt% Red, 6% o.w.f. 0.51% 8.94% Example 2 Blue, 4.5 wt% Blue, 6% o.w.f. 0.48% 9.71% Example 3 Yellow, 4.5 wt% Yellow, 6% o.w.f. 0.64% 7.82% Example 4 Red, 1.5 wt%
Blue, 1.5 wt%
Yellow, 1.5 wt% Red, 2% owf
Blue, 2% owf
Yellow, 2% owf 0.56% 8.60% Example 5 Red, 4.5 wt% Red, 6% o.w.f. 0.12% 13.43% Example 6 Red, 4.5 wt% Red, 6% o.w.f. 2.64% 4.76% Example 7 Red, 4.5 wt% Red, 6% o.w.f. 0.22% 17.98% Example 8 Red, 4.5 wt% Red, 6% o.w.f. 2.04% 3.13% Example 9 Red, 4.5 wt% Red, 6% o.w.f 0.09% 16.51% Example 10 Red, 4.5 wt% Red, 6% o.w.f. 3.06% 2.84% Example 11 Red, 4.5 wt% Red, 6% o.w.f. 2.26% 0.84% Example 12 Red, 4.5 wt% Red, 6% o.w.f. 0.20% 21.84% Comparative Example 1 Not used Red, 6% o.w.f. - - Comparative Example 2 Not used Blue, 6% o.w.f. - - Comparative Example 3 Not used Yellow, 6% o.w.f. - - Comparative Example 4 Not used Red, 2% owf
Blue, 2% owf
Yellow, 2% owf - -

The L value, the light fastness, the abrasion resistance, the lubrication degree, and the surface texture of each of the artificial leathers manufactured according to the foregoing Examples 1 to 12 and Comparative Examples 1 to 4 were measured / evaluated by the following methods And the results are shown in Table 3.

L value measurement of artificial leather

Tester: DATACOLOR 600

Light source: D65

UV: filter not used

specular: include

Measurement area: 3cm diameter Large

Measurement of light fastness of artificial leather

The lightfastness of artificial leather was measured as follows by MS 300-32 4.14.1, the evaluation criteria of automotive interior material of Hyundai Motor Co., Ltd., and the light fastness rating was determined using gray scale (ISO 105 A02) Table 3 shows the results.

Evaluation specification: MS 300-32 4.14.1

Tester: ATLAS Ci-4000 weather-O-meter

Black panel temperature 89 ° C ± 3 ° C

Light quantity: 66 W / m ²

Dose of 84 MJ / m ²

Air humidity 50% ± 5% RH

Measurement of abrasion resistance of artificial leather

According to the color abrasion method (ISO 12947-2: 1998 (E)), the specimen was rotated at a constant load (12kPa) for 35,000 cycles, and the color discoloration of the friction area was judged to be GRAY SCALE.

Lecture measurement

Cantilever method (KS K 0591) was used to measure the lubrication of artificial leather.

Appearance and surface tactile judgment of artificial leather

The surface texture is strongly influenced by the emotional aspect. Therefore, it is difficult to measure accurately by numerical value. Therefore, 30 persons and men who are 30 years old or older are examined. Based on the texture and texture of the brushed artificial leather without pigment coating And 5 grades were given to the students. The grades were graded according to the average score after sensory evaluation with different scores according to the brushed condition and touch as shown below.

Grade 5: Brushed condition and texture of untreated artificial leather

Level 4: There is no difference in brushed condition compared to level 5, but touch feeling is slightly lowered

Grade 3: Bristles are slightly clumped compared to grade 5 and slightly rougher

Level 2: Compared to Level 5, the bristles are much clumped and have rough texture

Level 1: Almost no brushed, rough and firm feeling

division L value Light fastness Lecture Surface touch Abrasion resistance
(discoloration) Example 1 36.2 3 6.35 4 4 Example 2 33.5 3 7.22 4 4 Example 3 45.8 3 7.55 4 4 Example 4 35.7 3 7.85 4 4 Example 5 38.5 3 7.74 5 3 Example 6 35.4 3-4 8.31 3 4 Example 7 37.8 3 8.43 4-5 3-4 Example 8 35.8 3 8.71 3-4 4 Example 9 40.2 2-3 8.41 5 3 Example 10 35.0 3-4 9.94 2-3 4 Example 11 35.5 3 9.03 3-4 3 Example 12 37.5 3 9.75 4-5 4 Comparative Example 1 41.1 2-3 - - - Comparative Example 2 40.3 2-3 - - - Comparative Example 3 52.4 2-3 - - - Comparative Example 4 43.2 2 - - -

100: artificial leather 110: preliminary artificial leather 120: pigment layer

Claims (11)

A preliminary artificial leather comprising a nonwoven fabric made of microfine fibers having a monofilament fineness of 0.001 to 3 denier and an elastic polymer impregnated in said nonwoven fabric; And
And a pigment layer formed by applying a pigment solution on the preliminary artificial leather,
Wherein the nonwoven fabric is dyed with a salt solution containing a disperse dye,
Wherein the pigment layer has an upper thickness of 0.1 to 3% of the thickness of the preliminary artificial leather and an impregnation depth of 1 to 20%, wherein the upper thickness is such that the pigment layer is in contact with the preliminary artificial leather And the penetration depth is a degree of penetration of the pigment layer into the interior of the preliminary artificial leather. The method according to claim 1,
Wherein the pigment layer comprises at least one pigment selected from the group consisting of carbon black, yellow pigment, red pigment, blue pigment, and green pigment. 3. The method of claim 2,
Wherein the pigment layer further comprises an aqueous polyurethane or an oily polyurethane. delete The method according to claim 1,
Wherein the disperse dye comprises at least one selected from the group consisting of an anthraquinone disperse dye, a condensate disperse dye, a quinoline disperse dye, a coumarin disperse dye, and an amino ketone disperse dye. 6. The method of claim 5,
Wherein said saline solution further comprises a triazine-based derivative as a UV-absorber. Producing a nonwoven fabric;
Impregnating the nonwoven fabric with an elastic polymer;
Fabricating the preliminary artificial leather by making the nonwoven fabric finer so as to have a single yarn fineness of 0.001 to 3 denier;
Applying a pigment solution on the preliminary artificial leather to form a pigment layer; And
And dyeing the preliminary artificial leather formed with the pigment layer with a salt solution containing a disperse dye,
Wherein the pigment layer is formed to have an upper thickness of 0.1 to 4% and a penetration depth of 5 to 50% with respect to a thickness of the preliminary artificial leather, wherein the upper thickness is a thickness of the pigment layer And the penetration depth is a degree of penetration of the pigment layer into the interior of the preliminary artificial leather. delete 8. The method of claim 7,
In the step of forming the pigment layer,
Applying the pigment solution onto the preliminary artificial leather; And
And drying the preliminary artificial leather coated with the pigment solution at 100 to 140 캜 for 5 to 10 minutes. 10. The method of claim 9,
Further comprising pre-buffing the preliminary artificial leather before forming the pigment layer. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt; 11. The method of claim 10,
And further comprising a buffing step after the dyeing step.

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