KR20250006376A - Sheet and artificial leather for automobiles using the same - Google Patents

Abstract

Disclosed is a sheet and an artificial leather for automobiles using the same.
A sheet constituting an artificial leather for an automobile according to the present invention, comprising: a first PVC; a second PVC; a first plasticizer; and a second plasticizer; and characterized in that the elongation at -20°C is 260% or more, the tensile strength at -20°C is 30 MPa or more, and the toughness at -20°C is 600 kj/m ³ or more.

Description

SHEET AND ARTIFICIAL LEATHER FOR AUTOMOBILES USING THE SAME

The present invention relates to a seat and an artificial leather for automobiles using the same.

To provide decorative functions and durability and flexibility for use in automobile interiors, artificial leather is used by sequentially laminating a foam layer, skin layer, and coating layer on a base fabric.

The skin layer that constitutes artificial leather is manufactured from PVC material, and PVC material exhibits a hard texture at a low temperature of -20℃. Therefore, artificial leather including the skin layer lacks low-temperature flexibility and cushioning, and thus has limitations in exhibiting low-temperature durability and a texture similar to natural leather. To solve this problem, a technology is being developed to increase the content of a flexibility additive, such as a low-molecular-weight plasticizer, contained in the skin layer of artificial leather.

However, as the content of low molecular weight plasticizer increases, the elongation of the skin layer increases, but the tensile strength decreases, and the skin layer is easily torn, which causes problems such as reduced durability. In addition, since the molar weight of the plasticizer is not large, if it is continuously exposed to heat, it is transferred to the surface of the artificial leather, damaging the appearance of the artificial leather.

In the case of commercialized artificial leather, there are limitations in low-temperature durability, and there are currently no products that satisfy the properties required by customers.

Therefore, it is necessary to develop artificial leather with excellent durability at low temperatures.

The purpose of the present invention is to provide a sheet having excellent durability at low temperatures and an artificial leather for automobiles using the same.

The purpose of the present invention is to provide a seat having an excellent appearance and an artificial leather for automobiles using the same.

The purposes of the present invention are not limited to the purposes mentioned above, and other purposes and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be easily understood that the purposes and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.

A sheet constituting an artificial leather for an automobile according to the present invention, comprising: a first PVC; a second PVC; a first plasticizer; and a second plasticizer; and characterized in that the elongation at -20°C is 260% or more, the tensile strength at -20°C is 30 MPa or more, and the toughness at -20°C is 600 kj/m ³ or more.

The degree of polymerization (DP) of the second PVC may be greater than that of the first PVC, and the weight average molecular weight of the second plasticizer may be greater than the weight average molecular weight of the first plasticizer.

The polymerization degree of the above first PVC may be 1000 to 1700, and the K-value of the above second PVC may be 84 or more.

With respect to the total 100 wt% of the first PVC and the second PVC, the first PVC may contain 60 to 80 wt% and the second PVC may contain 20 to 40 wt%.

The above first plasticizer may include at least one of a phthalate plasticizer, a terephthalate plasticizer, an adipate plasticizer, a trimellitate plasticizer, a benzoate plasticizer, a citrate plasticizer, a phosphate plasticizer, a glycol plasticizer, an aliphatic diester plasticizer, and a cyclohexane plasticizer.

The second plasticizer may include at least one polymer plasticizer selected from the group consisting of a dioctyl adipate plasticizer, an acrylonitrile plasticizer, a methyl methacrylate plasticizer, a butyl acetate plasticizer, an epoxy plasticizer, a polyester plasticizer, an ethylene plasticizer, a vinyl ether or alkyl acrylate-carbon monoxide terpolymer plasticizer, and an acetylated lactide oligomer plasticizer.

For a total of 100 parts by weight of the first PVC and the second PVC, a total of 100 to 120 parts by weight of the first plasticizer and the second plasticizer may be included.

It may contain 80 to 90 parts by weight of the first plasticizer and 10 to 40 parts by weight of the second plasticizer.

The artificial leather according to the present invention comprises: a base fabric; a foam layer disposed on a surface of the base fabric; a sheet disposed on the surface of the foam layer; and a coating layer disposed on the surface of the sheet; wherein the sheet comprises first PVC; second PVC; a first plasticizer; and a second plasticizer; and the sheet is characterized in that the elongation at -20°C is 260% or more, the tensile strength at -20°C is 30 MPa or more, and the toughness at -20°C is 600 kj/m ³ or more.

The sheet according to the present invention and the artificial leather for automobiles using the same can exhibit an elongation of 260% or more at -20°C, a tensile strength of 30 MPa or more at -20°C, a toughness of 600 kj/m ³ or more at -20°C, and excellent durability at low temperatures.

In addition, the sheet according to the present invention and the artificial leather for automobiles using the same have an excellent appearance.

In addition to the effects described above, the specific effects of the present invention are described below together with specific matters for carrying out the invention.

FIG. 1 is a cross-sectional view of artificial leather for an automobile including a sheet according to the present invention.
Figure 2 is a photograph of a ballyflex device according to the present invention.

The above-mentioned objects, features and advantages will be described in detail below with reference to the attached drawings, so that those with ordinary skill in the art to which the present invention pertains can easily practice the technical idea of the present invention. In describing the present invention, if it is judged that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

Hereinafter, the phrase “any configuration is disposed on (or below)” a component or “on (or below)” a component may mean not only that any configuration is disposed in contact with the upper surface (or lower surface) of said component, but also that another configuration may be interposed between said component and any configuration disposed on (or below) said component.

Additionally, when a component is described as being "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through other components.

Hereinafter, a sheet and an artificial leather for automobiles using the same according to some embodiments of the present invention will be described.

There is a growing need for low-temperature durability of artificial leather for automotive applications.

The skin layer that constitutes artificial leather contains PVC resin and a low-molecular-weight plasticizer, and technology is being attempted to increase the content of low-molecular-weight plasticizer in PVC.

However, as the content of low molecular weight plasticizer increases, the elongation at low temperatures increases, but the tensile strength decreases, causing the skin layer to tear easily, which ultimately reduces low-temperature durability. In addition, since the molar weight of the plasticizer is not large, it transfers to the surface of the artificial leather when continuously exposed to heat, damaging the appearance of the artificial leather.

In the case of commercialized artificial leather, there are limitations in low-temperature durability, and there are currently no products that satisfy the properties required by customers.

Accordingly, in order to solve the problem of lowering tensile strength when the content of low-molecular-weight plasticizer is increased, the inventors of the present invention increased the degree of polymerization (DP) of PVC, increased the content of general plasticizer, and added a small amount of high-molecular-weight plasticizer.

As a result, the inventors of the present invention confirmed that the skin layer simultaneously satisfies an elongation of 260% or more at -20°C, a tensile strength of 30 MPa or more at -20°C, and a toughness of 600 kJ/ ^m3 or more at -20°C. Finally, as a result of testing 50,000 times at -20°C using ballyflex equipment, it was confirmed that durability at low temperatures was improved without the occurrence of cracks.

In this way, in order to develop an artificial leather for automobiles having low-temperature durability in the present invention, it must satisfy a 50,000-cycle test at -20°C using a ballyflex device, and in order to satisfy this, parameters such as an elongation of 260% or more at -20°C, a tensile strength of 30 MPa or more at -20°C, and a toughness of 600 kj/m ³ or more at -20°C are required. In addition, in order to satisfy the parameters of elongation, tensile strength, and toughness at low temperatures, it is necessary to increase the degree of polymerization (DP) of PVC constituting the skin layer, increase the content of a low-molecular-weight plasticizer, and add a small amount of a high-molecular-weight plasticizer.

The ballyflex equipment referred to in the present invention is also called a bally flexure tester and can be used to determine the resistance of a material to cracking or breakage in bending creases.

The method for measuring low-temperature durability using ballyflex equipment can be performed as follows.

The specimen is folded in half and clamped at one end. The test specimen is then turned over and the free end is clamped at a 90° angle to the first clamp in the second clamp. The first clamp is oscillated repeatedly at a set speed and a fixed angle, causing the specimen to bend. The number of bending cycles is recorded at set intervals and any damage to the specimen can be visually assessed.

In the present invention, SCHAP 12 Station Cold Capable Bally Flex Tester & Flex Tester with Integrated Freezer was used, and low-temperature durability was measured according to the standard ISO 5402-1 (Leather - Determination of flex resistance).

The sheet (10) according to the present invention is a skin layer constituting artificial leather and can be placed between a foam layer (30) and a coating layer (40).

The sheet (10) includes a first PVC, a second PVC, a first plasticizer, and a second plasticizer, and is characterized by an elongation of 260% or more at -20°C, a tensile strength of 30 MPa or more at -20°C, and a toughness of 600 kj/m ³ or more at -20°C.

The sheet of the present invention is advantageous in satisfying low-temperature durability at -20°C when the elongation, tensile strength, and toughness are high. From this point of view, the elongation at -20°C can be 260 to 1000%, preferably 260 to 500%. The tensile strength at -20°C can be 30 to 200 MPa, preferably 30 to 150 MPa, and more preferably 30 to 100 MPa. The toughness at -20°C can be 600 to 3000 kj/m ³ , preferably 600 to 2000 kj/m ³ .

The sheet is mainly composed of polyvinyl chloride (PVC) resin. In order to increase the elongation of the sheet, the content of a general low-molecular-weight plasticizer is increased, but at this time, the tensile strength is reduced. Accordingly, the sheet is likely to tear and the durability is poor, so it is necessary to maintain or improve the tensile strength. From this point of view, it is desirable to increase the polymerization degree of PVC and add more high-molecular-weight plasticizer, which is a resin type, to increase the tensile strength at -20℃.

The degree of polymerization (DP) of the second PVC may be greater than that of the first PVC.

The polymerization degree of the second PVC may be 2650 or higher, the polymerization degree of the first PVC may be 1000 to 1700, and preferably, the polymerization degree of the first PVC may be 1000 to 1650.

In this case, the K-value of the first PVC is It can be 66 to 76, and the K-value of the second PVC can be 84 or higher, and preferably, the K-value of the second PVC can be 84 to 99.

K-value (K-value) is a value related to the intrinsic viscosity of a resin and is also called Fikentscher's K-value. K-value can be measured by the method of DIN EN ISO 1628-1.

The degree of polymerization of the resin can also be derived from the K-value. For example, when a PVC resin includes a polymerization resin of vinyl chloride alone, its degree of polymerization can be about 800 when the K-value is 60, its degree of polymerization can be about 1000 when the K-value is 66, its degree of polymerization can be 1300 when the K-value is 70, its degree of polymerization can be 1650 when the K-value is 76, its degree of polymerization can be about 2650 when the K-value is 84, and the maximum value of the K-value can be 99. The degree of polymerization of a polymerization resin of vinyl chloride alone indicates the number of vinyl chloride unit monomers that constitute the resin by polymerization.

If the polymerization degree of the second PVC is less than 2650, the polymerization degree increasing effect of the PVC constituting the sheet is low, and if the polymerization degree of the first PVC is outside of 1000 to 1700, the polymerization degree increasing effect of the PVC constituting the sheet is low or the problem of reduced absorbency of the plasticizer may occur.

In this way, the sheet can increase the polymerization degree of PVC by including the first PVC having a polymerization degree of 1000 to 1700 and the second PVC having a K-value of 84 or higher, and has the effect of maintaining or improving the tensile strength at -20℃.

The sheet may contain 60 to 80 wt% of the first PVC and 20 to 40 wt% of the second PVC, based on 100 wt% of the total of the first PVC and the second PVC.

By satisfying 60 to 80 wt% of the first PVC and 20 to 40 wt% of the second PVC, there is an advantage in securing excellent tensile strength at -20°C while maintaining the required physical properties of the sheet.

In the present invention, it is preferable that the sheet further contains a high molecular weight plasticizer of resin type in addition to a low molecular weight plasticizer of liquid type.

In the present invention, the first plasticizer is a low molecular weight plasticizer of a liquid type, the second plasticizer is a high molecular weight plasticizer of a resin type, and the weight average molecular weight of the second plasticizer may be greater than the weight average molecular weight of the first plasticizer.

Since the sheet contains a high molecular weight plasticizer, it has the advantage of exhibiting a tensile strength of 30 MPa or more and a toughness of 600 kj/m ³ or more at -20°C.

The first plasticizer may include at least one of a phthalate plasticizer, a terephthalate plasticizer, an adipate plasticizer, a trimellitate plasticizer, a benzoate plasticizer, a citrate plasticizer, a phosphate plasticizer, a glycol plasticizer, an aliphatic diester plasticizer, and a cyclohexane plasticizer, and preferably may include a phthalate plasticizer.

The above phthalate plasticizer may include, but is not limited to, one or more of dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), dioctyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), dipropylheptyl phthalate, dipentyl phthalate, and butylbenzyl phthalate (BBP).

The above terephthalate plasticizer is an environmentally friendly plasticizer, and examples thereof include, but are not limited to, dioctyl terephthalate.

The above adipate plasticizer may include, but is not limited to, bis(2-ethylhexyl)adipate, dimethyl adipate, monomethyl adipate, dioctyl adipate, or diisononyl adipate.

The above trimellitate plasticizer may include, but is not limited to, triisobutyl trimellitate, trinomaloctyl trimellitate, tri(2-ethylhexyl) trimellitate, or triisononyl trimellitate.

The above benzoate plasticizer may include, but is not limited to, 2-(2-(2-phenylcarbonyloxyethoxy)ethoxy)ethyl benzoate, glyceryl tribenzoate, trimethylolpropane tribenzoate, isononyl benzoate, 1-methyl-2-(2-phenylcarbonyloxypropoxy)ethyl benzoate, 2,2,4-trimethyl-1,3-pentanediol dibenzoate, n-hexyl benzoate, or trimethylol propane tribenzoate.

The above citrate plasticizer may include, but is not limited to, acetyltributyl citrate, tributyl citrate, acetyltriethylhexyl citrate or triethylhexyl citrate.

The above phosphate plasticizer may include, but is not limited to, tricresyl phosphate or tributyl phosphate.

The above glycol plasticizer may include, but is not limited to, ethylene glycol or propylene glycol.

The second plasticizer may include at least one polymer plasticizer selected from the group consisting of a dioctyl adipate plasticizer, an acrylonitrile plasticizer, a methyl methacrylate plasticizer, a butyl acetate plasticizer, an epoxy plasticizer, a polyester plasticizer, an ethylene plasticizer, a vinyl ether or alkyl acrylate-carbon monoxide terpolymer plasticizer, and an acetylated lactide oligomer plasticizer.

The above epoxy plasticizer is obtained by epoxidizing the double bond of an unsaturated fatty acid glycerol ester with hydrogen peroxide or peracetic acid, and may include, but is not limited to, epoxidized soybean oil or epoxidized linseed oil.

The above polyester plasticizer may include, but is not limited to, one or more of poly-2-ethylhexyl glycol adipate, adipic acid polyester, citric acid polyester, sebacic acid polyester, azelaic acid polyester, and phthalic acid polyester.

The alkyl acrylate in the above ternary copolymer resin may include, but is not limited to, one or more of methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butylacrylate, isobutylacrylate, sec-butylacrylate, tert-butylacrylate, methylbutylacrylate, amyl acrylate, isoamyl acrylate, n-hexylacrylate, cyclohexylacrylate, 2-ethylhexylacrylate, pentadecylacrylate, dodecylacrylate, isobornylacrylate, phenyl acrylate, benzylacrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-methoxyethyl acrylate, glycidyl acrylate, and allyl acrylate.

The second plasticizer is a high molecular weight plasticizer and may have a weight average molecular weight of 1,000 to 6,000 g/mole, preferably 1,500 to 5,000 g/mole.

The sheet may contain a total of 100 to 120 parts by weight of the first plasticizer and the second plasticizer, based on 100 parts by weight of the first PVC and the second PVC. In this case, the sheet may contain 80 to 90 parts by weight of the first plasticizer and 10 to 40 parts by weight of the second plasticizer.

By satisfying the total sum of the first plasticizer and the second plasticizer of 100 to 120 parts by weight, and satisfying the first plasticizer of 80 to 90 parts by weight and the second plasticizer of 10 to 40 parts by weight, there is an advantageous advantage of exhibiting an elongation of 260% or more at -20°C, a tensile strength of 30 MPa or more at -20°C, and a toughness of 600 kj/m ³ or more at -20°C.

In this way, the sheet of the present invention can secure properties without surface cracks when tested 50,000 times at -20℃ using ballyflex equipment due to the degree of polymerization and content of PVC and the molecular weight and content of the plasticizer, and has excellent low-temperature durability. In addition, the sheet has the effect of securing surface smoothness while having an excellent appearance.

The thickness of the sheet may be, but is not limited to, 100 to 300 μm.

The sheet may contain one or more additives such as, but not limited to, pigments, heat stabilizers, antistatic agents, antioxidants, lubricants, UV stabilizers, impact modifiers, and processing aids, as required.

A method for manufacturing a sheet may include a step of forming a sheet by calendering a composition comprising first PVC, second PVC, a first plasticizer and a second plasticizer.

The temperature of the roll during calendar processing may be 150 to 170℃, but is not limited thereto. Calendar processing is a plastic molding processing method that involves placing resin between two heated rolls and rolling it to create a film or sheet-shaped molded product. In addition, calendar processing may include covering the surface of cloth, paper, etc. with plastic.

The artificial leather for an automobile of the present invention may include the above-mentioned seat.

By applying the sheet of the present invention onto a backing cloth such as a woven fabric, artificial leather satisfying low-temperature durability can be manufactured, and the physical properties of an elongation of 260% or more at -20°C, a tensile strength of 30 MPa or more at -20°C, and a toughness of 600 kj/m ³ or more at -20°C secured in the sheet can exhibit the same results even when applied between a coating layer and a foam layer.

Specifically, as illustrated in FIG. 1, the artificial leather according to the present invention may include a base fabric (20), a foam layer (30) disposed on the surface of the base fabric, a sheet (10) disposed on the surface of the foam layer, and a coating layer (40) disposed on the surface of the sheet.

At this time, the sheet (10) includes a first PVC, a second PV, a first plasticizer, and a second plasticizer, and the sheet is characterized by having an elongation of 260% or more at -20°C, a tensile strength of 30 MPa or more at -20°C, and a toughness of 600 kj/m ³ or more at -20°C.

The base fabric (20) constituting the artificial leather can be used without limitation as long as it is a known fabric used as a base layer in PVC artificial leather. For example, the base fabric can be selected from woven fabric, nonwoven fabric, knitted fabric, mesh fabric (e.g., double raschel mesh fabric), etc. made of natural fiber or synthetic fiber. The synthetic fiber forming the woven fabric, nonwoven fabric, knitted fabric, or mesh fabric can be selected from polyester fiber, nylon fiber, or blended fiber.

The base fabric may further contain, but is not limited to, one or more of a flame retardant, a surfactant, and calcium carbonate, as required.

The thickness of the base fabric may range from 5 to 20 mm, but is not limited thereto.

The foam layer (30) that constitutes the artificial leather can provide a three-dimensional or cushioned feel to the artificial leather. The lower surface of the foam layer is in contact with the base fabric, and the upper surface of the foam layer is in contact with the sheet.

The foam layer can be manufactured by forming a composition containing PVC, a plasticizer, a foaming agent, a pigment, and a flame retardant into a polyvinyl chloride film by calendering, and then applying a predetermined amount of heat and pressure to foam it.

The PVC constituting the foam layer may have a polymerization degree of 800 to 2000, but is not limited thereto.

The blowing agent may include a capsule blowing agent or a chemical blowing agent. The capsule blowing agent is in the form of a foaming agent contained within a microscopic spherical thermoplastic plastic cell structure having a size of 1 to 1000 ㎛. When the capsule blowing agent is heated, the thermoplastic plastic cells soften, the foaming agent contained within them vaporizes, and the internal pressure increases, causing the capsule to expand and form a foam layer. Azodicarbonamide (ADCA), p,p'-oxybis(benzenesulfonyl hydrazide), p-toluenesulfonyl hydrazide, and sodium bicarbonate can be used as the foaming agent, but the present invention is not limited thereto.

The thickness of the foam layer may be, but is not limited to, 0.1 to 1 mm.

The sheet (10) constituting the artificial leather is the same as described above, so it will be omitted.

The coating layer (40) that constitutes the artificial leather prevents the sheet (skin layer) from being damaged by scratches or other external impacts, and prevents the sheet from being contaminated by external contaminants such as food or detergent while in use. Accordingly, the functions of the artificial leather such as light resistance, hydrolysis resistance, and chemical resistance can be improved, and the coating layer can be formed using an aqueous or oily treatment solution.

For example, the coating layer may include at least one of a polyurethane resin, an acrylic resin, a polyester resin, a silicone resin, and an amine resin, and preferably may include a water-based polyurethane resin. When the coating layer is formed with a polyurethane resin, it has the effect of reducing odor and volatile organic compounds, so that it can exhibit an environmentally friendly artificial leather.

Regarding the method for manufacturing artificial leather, artificial leather can be manufactured by sequentially laminating a foam layer (30) and a sheet (10) on a base fabric (20), foaming and heating, and forming a coating layer (40) on the sheet.

The lower surface of the foam layer and the base fabric or the upper surface of the foam layer and the surface layer can be bonded by calendar processing.

Specific examples of seats and artificial leather for automobiles using the same are as follows.

1. Manufacturing of seats and artificial leather for automobiles using the same

Examples and Comparative Examples

1) Sheets were manufactured by calendering the composition at 120°C under the conditions of Tables 1 to 4 below.

Diisodecyl phthalate was used as the first plasticizer, and Elvaloy, an ethylene polymer, was used as the second plasticizer.

The physical property results of the sheets according to the examples and comparative examples are shown in Tables 1 to 4 below, and even when the sheets were applied to artificial leather, the same physical property results as in Tables 1 to 4 were shown.

2) Artificial leather was manufactured using the sheets manufactured in the examples and comparative examples.

Artificial leather was manufactured through a step of bonding a foam layer and a base fabric made of rayon fiber woven fabric, a step of bonding the manufactured sheet to a laminate in which the foam layer and the base fabric are bonded, a step of passing the structure in which the sheet and the laminate are combined through a foaming machine to foam at 220°C, and a step of coating a water-based surface treatment agent containing a water-based polyurethane resin (trade name: UT-66 from Unitech Industry Co., Ltd.) on the sheet to form a coating layer.

2. Method for evaluating the physical properties of sheets and its results

1) Sheet appearance: Based on visual evaluation, if the surface condition is poor during sheet production, it is evaluated as X, and if the appearance is clean, it is evaluated as O.

2) Elongation (%), tensile strength (MPa), toughness (kj/m ³ ) at -20℃: ISO 527-3, Test Piece Type 1B, Test Speed (100 ± 10) mm/minute, Test Temperature: -20℃, Mount the chamber on the UTM (Universal testing machine) INSTRON 5969 equipment. After aging the specimen for 4 hours in the -20℃ chamber mounted on the UTM, open the chamber, mount it on the jig, close the chamber, and maintain it isothermal at -20℃ for 10 minutes, then perform the test at a speed of 100 mm/min. Through this, the elongation (strain) and tensile strength (stress) are measured, and the area value in the Stress/Strain curve (Graph) is calculated to obtain the toughness value.

3) Low-temperature durability evaluation: The durability was evaluated according to the ISO 5402-1 (Leather - Determination of flex resistance) standard using the Bally Resistance Flexing Tester (SCHAP 12 Station Cold Capable Bally Flex Tester & Flex Tester with Integrated Freezer). Specifically, the sheet specimen was mounted on the test jig, and the chamber temperature was set to -20℃. The appearance of the specimen was visually observed after 50,000 cycles. If cracks occurred in the specimen, it was evaluated as 'crack', and if no cracks occurred, it was evaluated as 'pass'.

[Table 1]

As shown in Table 1, Examples 1 to 3 satisfied the K-value and content of the first PVC, the first PVC, and the contents of the first plasticizer and the second plasticizer, thereby exhibiting a tensile strength of 30 to 33 MPa, an elongation of 260 to 270%, and a toughness of 610 to 630 kj/m ³ at -20°C. Accordingly, Examples 1 to 3 showed no cracks at all at 50,000 cycles at -20°C.

[Table 2]

As shown in Table 2, Examples 4 to 6 satisfied the K-value and content of the first PVC, the first PVC, and the contents of the first plasticizer and the second plasticizer, thereby exhibiting a tensile strength of 30 to 34 MPa, an elongation of 260 to 310%, and a toughness of 620 to 690 kj/m ³ at -20°C. Accordingly, Examples 4 to 6 showed no cracks at all at 50,000 cycles at -20°C.

[Table 3]

Referring to Table 3, Comparative Example 1 is a sample whose K-value is less than that of the first PVC, Comparative Example 2 is a sample whose K-value is greater than that of the first PVC and whose content is also greater than that of the second PVC, Comparative Example 3 is a sample whose K-value is less than that of the second PVC, and Comparative Example 4 is a sample whose K-value is greater than that of the first PVC and whose content is less than that of the second PVC.

Comparative Examples 1 to 4 did not satisfy any of the K-value and content of PVC and the content of plasticizer, and therefore the appearance of the sheet was poor, or at least one of the tensile strength, elongation, and toughness at -20°C was deteriorated. Accordingly, Comparative Examples 1 to 4 had poor appearance of the sheet, or cracks were observed at 50,000 cycles at -20°C.

[Table 4]

Referring to Table 4, Comparative Example 5 is a sample in which the content of the first PVC is less than the content of the second PVC, Comparative Example 6 is a sample in which the content of the first plasticizer is greater than the content of the second plasticizer and there is no second plasticizer, Comparative Example 7 is a sample in which the content of the first plasticizer is less than the content of the first plasticizer and greater than the content of the second plasticizer, and Comparative Example 8 is a sample in which the total sum of the first plasticizer and the second plasticizer exceeds 120 parts by weight.

Comparative Examples 5 to 8 did not satisfy any of the K-value and content of PVC and the content of plasticizer, and therefore the appearance of the sheet was poor, or at least one of the tensile strength, elongation, and toughness at -20°C was deteriorated. Accordingly, Comparative Examples 5 to 8 had poor appearance of the sheet, or cracks were observed at 50,000 cycles at -20°C.

Although the present invention has been described with reference to the drawings as examples, it is obvious that the present invention is not limited to the embodiments and drawings disclosed in this specification, and that various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. In addition, even if the effects according to the configuration of the present invention were not explicitly described while describing the embodiments of the present invention, it is natural that the effects that can be predicted by the corresponding configuration should also be recognized.

10 : Sheet
20: Base fabric
30: Foam layer
40: Coating layer

Claims (12)

As a sheet that constitutes artificial leather for automobiles,
It comprises a first PVC; a second PVC; a first plasticizer; and a second plasticizer;
At -20℃, the elongation is more than 260%,
The tensile strength at -20℃ is 30MPa or more.
Sheet having a toughness of 600kJ/ ^m3 or more at -20℃.
In the first paragraph,
A sheet wherein the polymerization degree (DP) of the second PVC is greater than that of the first PVC.
In the first paragraph,
A sheet wherein the weight average molecular weight of the second plasticizer is greater than the weight average molecular weight of the first plasticizer.
In the first paragraph,
A sheet having a polymerization degree of the above first PVC of 1000 to 1700.
In the first paragraph,
A sheet having a K-value of 84 or higher of the above-mentioned second PVC.
In the first paragraph,
A sheet comprising 60 to 80 wt% of the first PVC and 20 to 40 wt% of the second PVC, based on 100 wt% of the total of the first PVC and the second PVC.
In the first paragraph,
A sheet comprising the first plasticizer at least one selected from the group consisting of a phthalate plasticizer, a terephthalate plasticizer, an adipate plasticizer, a trimellitate plasticizer, a benzoate plasticizer, a citrate plasticizer, a phosphate plasticizer, a glycol plasticizer, an aliphatic diester plasticizer, and a cyclohexane plasticizer.
In the first paragraph,
A sheet including at least one polymer plasticizer selected from the group consisting of a dioctyl adipate plasticizer, an acrylonitrile plasticizer, a methyl methacrylate plasticizer, a butyl acetate plasticizer, an epoxy plasticizer, a polyester plasticizer, an ethylene plasticizer, a vinyl ether or alkyl acrylate-carbon monoxide terpolymer plasticizer, and an acetylated lactide oligomer plasticizer.
In the first paragraph,
A sheet comprising a total of 100 to 120 parts by weight of a first plasticizer and a second plasticizer, relative to a total of 100 parts by weight of the first PVC and the second PVC.
In Article 9,
A sheet comprising 80 to 90 parts by weight of the first plasticizer and 10 to 40 parts by weight of the second plasticizer.
Artificial leather comprising a sheet according to paragraph 1.
Base fabric;
A foam layer disposed on the surface of the above base fabric;
A sheet disposed on the surface of the foam layer; and
A coating layer disposed on the surface of the sheet;
The above sheet comprises a first PVC; a second PVC; a first plasticizer; and a second plasticizer;
The above sheet
At -20℃, the elongation is more than 260%,
The tensile strength at -20℃ is 30MPa or more.
Artificial leather with a toughness of 600kJ/ ^m3 or higher at -20℃.