KR100951976B1 - Artificial leather used in conveyance with excellent shrinkage properties - Google Patents

Abstract

The present invention relates to a vehicle artificial leather with excellent elongation characteristics, the composite sheet consisting of a non-woven fabric and microfiber short fibers of 0.3 denier or less interwoven with each other and interwoven with the microfiber short fibers of the nonwoven fabric The present invention relates to a vehicle artificial leather which is filled with a polymer elastic body, has a peak peak elongation of 8 to 25%, a permanent strain of 2 to 10%, and a stretch index obtained by dividing the peak peak elongation by the permanent strain. . The artificial leather for a vehicle manufactured according to the present invention has an appropriate elongation property and maintains good shape stability even for long-term use, and also has excellent cushioning and feel.

Artificial leather, vehicle, elongation, elasticity index, permanent strain, shape stability

Description

Artificial leather used in conveyance with excellent shrinkage properties

The present invention relates to a vehicle artificial leather with excellent elongation characteristics, and more particularly, to a vehicle artificial leather having proper elongation characteristics and maintaining good shape stability even during long-term use, and excellent in cushioning and touch.

Artificial leather is composed of a nonwoven fabric in which microfibers are intertwined in three dimensions and a polymer elastomer impregnated in the nonwoven fabric. The artificial leather has excellent feel, light effect and drape, and has a soft texture and unique appearance similar to that of natural leather. BACKGROUND ART It is widely used as a sheet skin material or interior material of a vehicle (hereinafter, referred to as "vehicle") for transportation such as trains and ships.

Artificial leather used for vehicle materials (hereinafter referred to as "vehicle artificial leather") is required for durability and shape stability against friction and external force, and is suitable for bending and mounting work due to its characteristics of being used in many curved areas. This is required.

Korean Patent No. 10-0681377 discloses a method of imparting elasticity to artificial leather using a nonwoven fabric manufactured to have anisotropy by appropriately controlling the orientation structure of fibers in the nonwoven fabric. However, the artificial leather produced by the conventional method is low in form stability because the elasticity is given only by the anisotropy of the non-woven fabric has caused a problem that is not suitable for artificial leather for vehicles.

In another prior art, Korean Patent No. 0658097 discloses artificial leather produced by filling artificial polyurethane with a composite sheet composed of (i) a nonwoven fabric and (ii) a woven or knitted fabric having a static load elongation of 10 to 30%. Although a method of imparting good elongation characteristics to leather is disclosed, the conventional method has a problem in that the elastic recovery rate is bad because it does not effectively manage the permanent strain, which is closely related to the elasticity, and the shape deformation occurs when used for a long time.

In order to solve the above problems, the present invention is to provide a vehicle artificial leather excellent in cushioning and feel while maintaining a good shape stability even when used for a long time with the proper elongation characteristics.

The present invention is an artificial leather made of a polymer elastic material is filled in a composite sheet made of a nonwoven fabric in which ultrafine short fibers having a thickness of 0.3 denier or less are entangled with each other, and a fabric which is interwoven with the ultrafine short fibers of a nonwoven fabric in the nonwoven fabric. ,

It is characterized by a vehicle artificial leather having excellent elongation characteristics of 1.5 to 3.0, having an elasticity index of 1.5 to 3.0 obtained by dividing the highest peak elongation by 8 to 25%, a permanent strain of 2 to 10%, and dividing the highest peak elongation by the permanent strain. .

The present invention is provided with an appropriate elongation characteristics to maintain good shape stability even during long-term use, excellent cushioning and feel.

The artificial leather for a vehicle according to the present invention is filled with a polymer elastic body in a composite sheet composed of a nonwoven fabric in which microfine short fibers having a thickness of 0.3 denier or less are interlaced with each other, and a fabric interwoven with microfine short fibers of a nonwoven fabric in the nonwoven fabric. Has a structure. The composite sheet contains 60 to 95% by weight of the nonwoven fabric and 5 to 40% by weight of the fabric. When the content of the nonwoven fabric is less than 60% by weight, the surface feel is deteriorated and the appearance quality is deteriorated. In this case, it is preferable to maintain the above range because it becomes too hard to lose the soft characteristics that artificial leather should have. In addition, the polymer elastomer is contained in the range of 10 to 40% by weight with respect to the composite sheet, when the content is less than 10% by weight, the elasticity is lowered, the elongation is lowered, if the content exceeds 40% by weight, wrinkles after stretching It is preferable to maintain the above range because problems arise.

In addition, the artificial leather for vehicles according to the present invention has a peak peak elongation of 5 to 40%, preferably 8 to 25%, and a permanent strain of 0 to 15%, preferably 2 to 10%, as measured by the evaluation method described below. The elasticity index obtained by dividing the peak peak elongation by the permanent strain is 0.5 to 5.0, preferably 1.5 to 3.0. If the elasticity index exceeds the above range, the elastic recovery is good, but if the elastic index is excessively extended and a strong load is applied, it is difficult to maintain the shape. If the elasticity index is lower than the above range, the cushioning feeling and the touch are reduced, and the dimensional stability Low profile results in poor shape stability.

In addition, the maximum load elongation of the artificial leather for vehicles according to the present invention is 0.2 to 1.5 times, preferably 0.6 to 1.0 times the maximum load elongation of the fabric, the permanent strain of the vehicle artificial leather is 0.1 to 2 times the permanent strain of the fabric, Preferably it is 0.1-1.2 times, and the elasticity index of the artificial leather for vehicles is 0.2-3.0 times with respect to the elasticity index of a raw material, Preferably it is 0.6-2.0 times.

The polymer elastomer is a polyurethane resin, a polyurea resin, or the like, and a polyurethane resin is most preferable in view of workability.

The ultrafine short fibers may be polyamide fibers or polyester fibers, and the present invention does not specifically limit the kind of ultrafine short fibers.

The single yarn fineness of the said ultrafine short fibers is 0.3 denier or less, More preferably, it is 0.001-0.3 denier. When the single yarn fineness is less than 0.001 denier, the strength of the artificial leather is lowered. If the single yarn fineness is more than 0.3 denier, the touch and lighting effect of the artificial leather may be lowered.

The fabric is a woven or knitted fabric, which serves as a kind of reinforcement.

The fabric constituting the composite sheet has a maximum peak elongation of 10 to 30%, a permanent strain of 0.5 to 10%, and a stretch index obtained by dividing the maximum peak elongation by a permanent strain of 1.5 to 10, as measured by the evaluation method described below. It is preferable that it is 5.0.

The properties of the fabric are the most important factors in determining the properties of the artificial leather described above. Since the physical properties of the fabric tend to be smaller when combined with the nonwoven fabric, it is important to satisfy the above range with the properties of the fabric in order for the vehicle artificial leather according to the present invention to have the above-described physical properties.

In order to control the properties of the fabric, a combination of polymer type, spinning conditions, stretching and processing conditions, weaving conditions, and the like is appropriately combined.

Conventional artificial leather composed of a nonwoven fabric made of ultrafine fibers and a polymer elastic body impregnated in the nonwoven fabric without the reinforcing material is not suitable as a vehicle artificial leather because the maximum peak elongation, permanent strain, and elasticity index is too large.

It is preferable that the density of the said composite sheet is 0.300-0.5 g / cm <3>.

In addition, the fabric used in the present invention is 10 to 60% by weight of polyethylene terephthalate yarn, polytrimethylene terephthalate yarn, polybutylene terephthalate yarn, polyurethane yarn, polyolefin yarn and polytetramethylene glycol It is possible to use a single yarn or a mixture of two or more yarns selected from the contained polyester yarns. The yarn constituting the fabric is a filament yarn or a staple yarn.

The fabric as the reinforcing material can be entangled by a needle punching method to the short fiber web layer of the nonwoven fabric or by a method of entangled by high pressure water flow (water jet).

Manufacturing of artificial leather for a vehicle of the present invention excellent in elongation characteristics is made through a series of processes as follows.

Specifically, a fabric having a peak peak elongation of 10 to 30%, a permanent strain of 0.5 to 10%, and an elasticity index of 1.5 to 5 measured by an evaluation method described below is prepared, and the thickness after elution or dividing is 0.3 denier or less. A microfiber short fiber web is prepared to bond the fabric and the microfiber web by a needle punching method. In order to prevent the fabric from being damaged, the number of needle barbs is one or less, and the angle of the barbs is adjusted to minimize the probability of contact with the fabric. The punching density required for bonding is preferably 1500 to 3000 PPSC. The density of the composite sheet in which the fabric is bonded is about 0.3 to 0.5 g / cm 3.

The ultrafine short fiber web is made of an eluting two-component composite fiber composed of an eluting component (sea component), which is an alkali-soluble copolyester, and a fiber-forming component (water component) dispersed in the eluting component (sea component). The alkali-soluble copolymer polyester may be a low molecule or monomer having a molecular weight of 100 to 4000 in polyethylene terephthalate, specifically polyethylene glycol, polypropylene glycol, 1,4-cyclohexanedicarboxylic acid, 1,4 -Cyclohexanedimethanol, 1,4-cyclohexanedicarboxylate, 2,2-dimethyl-1,3-propanediol, 2,2-dimethyl-1,4-butanediol, 2,2,4-trimethyl1 Copolymerized polyesters obtained by copolymerizing one or two or more selected from, 3-propanediol and adipic acid in an amount of 35% by weight or less, preferably 5 to 25% by weight can be used.

The ultrafine short fibers of 0.3 denia or less used in the present invention may be composed of one or two or more components of polyamide-based polymers, polyurethane-based polymers, polyester-based polymers, polyolefin-based polymers, and polyurethane-based polymers. .

Next, the nonwoven fabric-fabric composite sheet prepared as described above was padded with a water-soluble polymer solution such as polyvinyl alcohol or carboxymethyl cellulose at a concentration of 3 to 15% by weight and dried to obtain 5 to 20% by weight based on the weight of the fiber. Grant.

This process is effective in preventing subsequent wet processing polyurethane from excessively adhering to the micronized fiber and hardening the touch.

Next, a polyurethane wet impregnation process is performed on the composite sheet. Polyurethane elastomers used in this process are readily dissolved in dimethyl formamide (hereinafter referred to as 'DMF') as a linear polymeric material consisting of macroglycols, diisocyanates and low molecular weight diols or diamines, or as some crosslinkable polymeric materials. As the macroglycol used in the present invention, polyether glycol, polyester glycol, polyether polyester copolymerized glycol, polycarbonate glycol and the like are applicable.

In the present invention, as the low molecular weight diol, 4,4'-butanediol, ethyl glycol, and the like may be used, and a diamine-based chain extension agent such as methylene-bis- (4,4'-phenylamine) may be applied. Surfactant, pigment, functional particles, etc. are added to the DMF solution of this polyurethane elastomer, and the concentration is diluted to use as an impregnation solution.

After the composite sheet is dipped into the impregnation solution, the polyurethane is solidified in an aqueous solution, washed with hot water at 50 to 80 ° C., and then completely filled with water-soluble polymer and dried. The content of the polyurethane after drying is preferably 20 to 50% by weight.

Subsequently, the elution component is removed with a solvent or caustic soda aqueous solution which is capable of dissolving or dividing the eluting component (sea component), thereby performing an ultrafine fiber step.

If the eluting component (sea component) is a copolyester, it is treated with 5 to 15% by weight aqueous solution of caustic soda in a continuous or discontinuous batch manner to decompose the eluting component.If the eluting component is polyethylene or polystyrene, toluene or perchloro Remove with ethylene or trichloroethylene.

For example, the sea component copolyester is completely decomposed and removed by treatment with a 10% aqueous solution of caustic soda at about 100 ° C. for 5 to 10 minutes. At this time, the composite sheet composed of the nonwoven fabric and the fabric has a slight thickness reduction by removing the elution component (sea component), but the shape is well maintained by the tissue of the fabric or knitted fabric, and the elongation in the longitudinal direction is not large due to mechanical tension. The apparent density of the composite sheet surface is improved.

On the other hand, in the present invention, the composite sheet prepared as described above is first treated with an aqueous alkali solution to elute the eluting component (sea component), and then impregnated with polyurethane.

Next, the surface of the leather composite sheet thus obtained is buffed with a buffer equipped with sandpaper of appropriate roughness to form hair on the surface and trim the wool. The roughness of the sandpaper is selected differently according to the use, but it is preferable to use 150-400 mesh.

The leather-like composite sheet fabric in which the wool is formed is dyed to suit the purpose. When the fiber used is nylon-6, it is usually dyed with a metal-containing dye or a milling type acid dye, and in the case of a polyester-based dye, it is dyed in a high pressure rapid dyeing machine.

Lastly, the dyed product is subjected to flexible and functional drug processing to manufacture artificial leather for vehicles.

Automotive artificial leather manufactured by the present invention has a maximum load elongation of 8 to 25%, a permanent strain of 2 to 10%, an elasticity index of 1.5 to 3, very excellent in elongation characteristics and durable against external force. As well as having a feature of easy sewing and mounting work of a lot of bending.

In particular, the present invention effectively manages the permanent strain that correlates with the elasticity has a shape stability in long-term use.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited to the following Examples.

Example 1

75% by weight of polytrimethylene terephthalate was used as a fiber-forming component, and 25% by weight of copolyester was used as an extracting component to prepare an ultrafine island-in-the-sea composite fiber having a total thickness of 75 deniers through a spinning process. At this time, the monofilament of the long fiber was 3.1 denia and the number of microfiber fibers (fiber forming component) in the monofilament was 16. It was crimped and set at 165 ° C. The island-in-the-sea composite filament thus obtained was given a twist of 600 times per meter using a twisting machine, and then used a warp and weft yarn to make a regular beam. The warp and weft yarns were fabrics having a warp density of 65 bones / inch and a weft density of 65 bones / inch. The peak peak elongation of the fabric produced was 14%, the permanent strain was 7%, and the elasticity index was 2.

On the other hand, the short fibers are polyethylene terephthalate 70% by weight of the fiber-forming component, 30% by weight of the copolyester polyester as the extraction component through a process of spinning and crimping, 51 mm in length, single yarn is 2.5 denier, Short fibers of 36 microfiber fibers (fibrous forming component) in the monofilament were prepared.

Meanwhile, the web was formed through the short fiber carding-cross lapping process, and needle punching was performed to bond the fabric to the above fabric to form a composite sheet. In this case, the composite sheet is 90% by weight of the nonwoven fabric and the fabric (fabric) will contain 10% by weight.

The nonwoven-woven (fabric) composite sheet was then padded and dried with an aqueous 10% by weight polyvinyl alcohol solution to give 10% by weight to the fiber weight. Immediately thereafter, the polyurethane elastomer of the polyether polyester copolymer glycol type was diluted in dimethylformamide (DMF), the composite sheet was dipped in an impregnation solution having a concentration of 15% by weight, and then solidified in an aqueous polyurethane solution, followed by solidification at 70 占 폚. It washed with water in the hot water solution of, and completely removed the polyvinyl alcohol polymer, and dried. The content of the polyurethane after drying was 30% by weight. Next, the above composite sheet was continuously treated at 10 ° C. in an aqueous solution of caustic soda at 100 ° C. to completely remove the sea component co-polyester and to make the fiber micron so that only the fine component polyester micro component remained. Subsequently, roughening # 240 sandpaper was applied to the buffing process to cut off a part of the microfiber fibers to raise and express the wool, and then dyed in a high-pressure rapid dyeing machine with excellent fastness to dyeing, followed by reduction washing and drying. Subsequently, a vehicle artificial leather was manufactured through a water repellent agent and an antistatic agent treatment process and a Momi soft process. Evaluation of the physical properties of the artificial leather for the vehicle manufactured as described above is shown in Table 1 below.

Example 2

Carried out in the same manner as in Example 1, using a fabric having a load peak elongation of 14%, a permanent strain of 7%, the elasticity index of 2 was manufactured for a vehicle artificial leather.

Example 3

Carried out in the same manner as in Example 1, 35% by weight of polyurethane content, 58% by weight of nonwoven fabric, 7% by weight of the fabric was manufactured for the artificial leather for the vehicle.

Comparative Example 1

In the same manner as in Example 1, when manufacturing a composite sheet and artificial leather, artificial leather for the vehicle was manufactured using a fabric having a peak peak elongation of 44%, a permanent strain of 11%, and an elasticity index of 4.

Evaluation of the physical properties of the artificial leather for the vehicle manufactured above is shown in Table 1 below.

Comparative Example 2

In the same manner as in Example 1, the artificial leather for the vehicle was manufactured by manufacturing a non-woven web only with short fibers without using a fabric or knitted fabric as a reinforcement material when manufacturing artificial leather.

Evaluation of the physical properties of the artificial leather for the vehicle manufactured above is shown in Table 1 below.

The following Table 1 is to measure the physical properties of the artificial leather for vehicles manufactured in Examples 1 to 3 and Comparative Examples 1 to 2 briefly measured in a table. At this time, physical properties were measured by the following method.

1) Ultrafine short fiber thickness and fineness (denier) measurement

A cross-sectional sample of the manufactured artificial leather was taken and subjected to a preparatory process such as gold coating, and a cross-sectional photograph of the artificial leather composite sheet was taken at a constant magnification through a scanning electron microscope [SEM] analyzer. After evaluating the diameter of one strand of the microfiber shown in the photograph and converting it to the actual value, the fineness was obtained through Equation 1.

[Equation 1]

Fineness (denier) = 9πD ² ρ / 4000

In Equation 1, π is a circumference, D is a microfiber cross-sectional diameter (µm), and ρ is a microfiber density value (g / cm 3). For reference, the density of nylon is 1.14 g / cm 3 and the density of polyethylene terephthalate is 1.38 g / cm 3.

2) Peak peak elongation and permanent strain

A specimen 50 mm long by 250 mm long was placed in a tensile tester with a gauge length (L ₀ ) of 130 mm, then a maximum load of 8 kg _f from a minimum load of 0 kg _f at an x-head speed of 200 m / min. Apply the load at a constant speed up to and then repeat the process of reducing the load up to the minimum load at a constant speed 100 times to determine the length (L ₁ ) at the time when the load is applied to the maximum load (8 kg _f ) for the 100th time. Calculate the maximum load elongation by substituting it into the following Equation 1, the length (L ₂ ) at the point when the load is reduced to the minimum load (0 kg _f ) at constant speed again after giving the highest load in the 100th time. After obtaining, the resultant is substituted into Equation 2 to calculate the permanent strain.

[Equation 2]

Load Peak Elongation (%) = (L ₁ -L ₀ ) / (L ₀ ) × 100

[Equation 3]

Permanent Strain (%) = (L ₂ -L ₀ ) / (L ₀ ) × 100

3) cushion

The higher the score on the scale of 1-9 points, the better the cushioning feeling, when the vehicle is mounted on the vehicle by an evaluation group composed of at least 10 experts and at least 10 non-experts. Calculate as an average value.

4) touch

An evaluation score of at least 10 experts and at least 10 general non-experts, the higher the score on the scale of 1-9 points, the better the feel. Calculate

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Peak load elongation (%) 16 15 24 36 40 Permanent Strain (%) 8 10 8 10 10 Elasticity index 2.0 1.5 3.0 3.6 4.0 Cushion 7.0 6.6 7.8 6.4 4.2 touch 8.2 7.2 7.8 6.8 6.2

As shown in Table 1, Example 1 obtained according to the present invention can be expected not only to maintain the appropriate range of the peak peak elongation, permanent strain, etc., but also to maintain the elasticity index of 2.0, and excellent cushioning and feel.

Claims (11)

An artificial leather made of a polymer elastic material filled in a composite sheet made of a nonwoven fabric in which microfine short fibers having a thickness of 0.3 denier or less are interlaced with each other and a fabric interwoven with microfine short fibers of a nonwoven fabric in the nonwoven fabric. A vehicle artificial leather having excellent elongation characteristics, characterized by an elasticity index of 1.5 to 3.0 obtained by dividing the highest peak elongation by 8 to 25%, a permanent strain by 2 to 10%, and dividing the highest peak elongation by the permanent strain. According to claim 1, wherein the fabric has a peak peak elongation of 10 to 30%, a permanent strain is 0.5 to 10%, the elasticity index is obtained by dividing the peak peak elongation by the permanent strain is 1.5 to 5.0, characterized in that Automotive artificial leather with excellent elongation characteristics. The method of claim 1, wherein the fabric contains 10 to 60% by weight of polyethylene terephthalate yarn, polytrimethylene terephthalate yarn, polybutylene terephthalate yarn, polyurethane yarn, polyolefin yarn and polytetramethylene glycol Automotive artificial leather with excellent elongation characteristics, characterized in that the single yarn or a mixture of two or more selected from polyester-based yarns. The vehicle artificial leather with excellent elongation characteristics according to claim 1, 2 or 3, wherein the fabric is one selected from woven fabrics and knitted fabrics. 2. The vehicle artificial leather having excellent elongation characteristics according to claim 1, wherein the composite sheet has a density of 0.3 to 0.5 g / cm 3. The artificial leather of claim 1, wherein the composite sheet contains 60 to 95 wt% of nonwoven fabric and 5 to 40 wt% of fabric. The artificial leather for a vehicle having excellent elongation characteristics according to claim 1, wherein the polymer elastomer is a polyurethane resin or a polyurea resin. 8. The artificial leather for an automobile having excellent elongation characteristics according to claim 1 or 7, wherein the polymer elastic body is contained in a range of 10 to 40 wt% based on the composite sheet. The vehicle artificial leather of claim 2, wherein the maximum load elongation of the artificial leather for the vehicle is 0.6 to 1.0 times that of the maximum load elongation of the fabric. 3. The vehicle artificial leather having excellent elongation characteristics according to claim 2, wherein the permanent strain of the artificial leather for the vehicle is 0.1 to 1.2 times the permanent strain of the fabric. The vehicle artificial leather of claim 2, wherein the elasticity index of the artificial leather for the vehicle is 0.6 to 2.0 times greater than the elasticity index of the fabric.