WO2019054732A1 - Artificial leather and manufacturing method therefor - Google Patents

Abstract

The present invention relates to an artificial leather and a manufacturing method therefor and, specifically, to: artificial leather used for vehicle seat covers, which has natural leather-like texture and soft touch, and exhibits excellent peel strength; and a manufacturing method therefor.

Description

Artificial leather and its manufacturing method

The present invention relates to an artificial leather and a method of manufacturing the same, and more particularly, to an artificial leather used as an automobile seat cover, a synthetic leather having a texture similar to that of natural leather, a soft touch feeling and excellent peel strength, and a method for manufacturing the same.

In general, the inside of a car is recognized as a second residential space, and recently, a functional seat has been spotlighted for comfortable and comfortable driving in the interior space of such a car.

Natural leather, artificial leather such as polyvinyl chloride, and polyurethane are used as materials for such a car seat. Artificial leather is less expensive than natural leather, but functional parts to maintain a comfortable state of luxury and sensibility when driving is much less than natural leather.

Therefore, the artificial leather which can meet the sensibility and the functional aspect of natural leather has been developed steadily. That is, there are some advantages such as a high moisture permeability and a reduction in the surface temperature of a summer seat because of advantages in terms of functionality of natural leather. This is a characteristic that occurs when moisture and heat are passed through the surface of natural leather and numerous pores formed inside.

Specifically, the artificial leather of the related art has a laminated structure including a back layer, a foam layer, a skin layer and a surface treatment layer from the bottom as disclosed in Korean Patent Registration No. 10-1450604 (published on Oct. 23, 2014) .

In this case, the foam layer and the skin layer are mainly made of polyvinyl chloride or polyurethane, and laminated to a predetermined thickness through a calendaring or casting process . Thereafter, the foaming layer is foam-molded at a predetermined ratio while being subjected to a foaming process.

On the other hand, the emboss is formed by using a roller pressing method in which the embossed material is transferred between the emboss rollers so as to add texture and cushioning feeling of natural leather to the upper side of the semi-finished product in which the back layer, the foam layer and the skin layer are laminated.

However, in the embossing method using the roller pressing method, a predetermined peeling strength can be given to the artificial leather by applying a large pressure to the semi-finished product. However, when the foamed cells in the foamed layer are destroyed, , An elongated shape, a protruding shape, and the like can not be maintained.

[Prior art document]

[Patent Literature]

(Patent Document 1) KR 10-1450604 B (Notification Date: Oct. 24, 2014)

It is an object of the present invention to provide an artificial leather having a texture similar to that of natural leather and a soft touch.

Another object of the present invention is to provide an artificial leather excellent in peel strength.

Another object of the present invention is to provide a synthetic leather excellent in cushioning feeling by preventing the foam cell constituting the foam layer from being crushed or broken.

In order to achieve the above object,

The present invention relates to an artificial leather having a microhardness of 45-59, wherein the microhardness is measured by a micro hardness meter (Asker Micro Durometer, model: MD-1 CAPA) in a peak hold mode at a pressing speed of 1 mm / Wherein the maximum value is measured immediately after the needle is in contact, that is, when the load holding time of the needle is 1s.

The present invention also provides artificial leather in which one side of the backing layer is coated with a coating solution.

The present invention also relates to a method for manufacturing a backing layer,

A preformed foam layer or a foamed layer and a skin layer forming a prefoamed or foamed layer and a skinned layer, respectively;

A backside layer stacking step of stacking the backside layer on the bottom of the prefoamed or foamed layer;

A skin layer laminating step of laminating the skin layer on the pre-foamed layer or the foamed layer on which the backside layer is formed;

Forming a surface treatment layer by coating an aqueous surface treatment agent on the skin layer to form a surface treatment layer;

An infrared ray irradiation step of irradiating infrared rays onto the surface treatment layer;

And an embossing step of forming an emboss by using vacuum on the skin layer and the surface treatment layer heated by the infrared ray irradiation,

The artificial leather has a microhardness of 45-59,

The microhardness was measured immediately after the needle contacted the artificial leather at a pressing speed of 1 mm / s in a peak hold mode using a microhardness tester (Asker Micro Durometer, model: MD-1 CAPA) And the maximum value at 1 s is measured.

The artificial leather of the present invention has an effect of having a texture similar to that of natural leather and a soft touch.

The artificial leather of the present invention can realize an effect of excellent peel strength.

In addition, the artificial leather of the present invention can prevent the foamed cell constituting the foamed layer from being crushed or broken, thereby realizing an excellent cushioning effect.

1 is a side sectional view showing a laminated structure of artificial leather according to the present invention.

FIG. 2 is a flowchart showing an embodiment of a method for manufacturing artificial leather according to the present invention.

FIG. 3 is a flowchart showing another embodiment of a method of manufacturing artificial leather according to the present invention.

4 is a photograph showing the surface (emboss) of the artificial leather of the present invention.

Fig. 5 is a view schematically showing a method of measuring the gloss difference of the appearance of the synthetic leather surface.

FIG. 6 is a photograph showing the degree of liquid penetration when measuring the surface tension of a surface treatment layer formed using an oil-based surface treatment agent.

FIG. 7 is a photograph showing the degree of liquid penetration when measuring the surface tension of the surface treatment layer formed using the aqueous surface treatment agent according to the present invention. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings, the same reference numerals as in the drawings denote the same elements in the drawings, unless they are indicated on other drawings.

The present invention relates to artificial leather having a microhardness of 45-59, or 50-57.

The microhardness is a local hardness for a minute specimen such as a thickness of about 0.5-1.5 mm and is measured in a peak hold mode at a pressing speed of 1 mm / s using a microhardness tester (Asker Micro Durometer, Model: MD-1 CAPA) The maximum value was measured immediately after the needle was in contact with the leather, that is, when the load holding time of the needle was 1s.

Specifically, there are various methods of measuring the hardness. Examples include hardness shore ('HS'), hardness rock ('HR'), hardness vickers ('HV'), Hardness Knoop ('HK') and microhardness. In the above various hardness measuring methods, shore hardness is commonly used for measuring hardness of artificial leather.

However, Shore hardness is a method of measuring a specimen having a thickness of 5 mm or more, and is not suitable for measuring the hardness of a minute specimen having a thickness of less than 5 mm.

As an example of a microhardness tester for measuring microhardness, MD-1 CAPA of Asker Micro Durometer may be used as an example of a microhardness hardness of less than 5 mm, for example, a hardness of 0.5 to 1.5 mm have.

In the present invention, when the microhardness exceeds the above range, the touch feeling is not general and smooth, and when the microhardness is less than the above range, the mechanical properties such as abrasion property are lowered. Therefore, the microhardness within the above- have.

The present invention also relates to a synthetic leather on one side of which is coated with a coating solution.

Fig. 1 is a cross-sectional side view showing a laminated structure of artificial leather according to the present invention. The artificial leather 1 of the present invention has a back layer 11, a foam layer 13b, 13b ', a skin layer 15 And an embossing 19 formed on the skin layer 15 and the surface treatment layer 17 including the surface treatment layer 17.

Each layer of artificial leather according to the present invention will now be described in more detail.

The backside layer (11)

The back layer 11 of the present invention assists mechanical properties and plays a role of maintaining shape and preventing wrinkles of artificial leather. The back layer 11 is made of cotton, rayon, silk, polyolefin (for example, polyethylene, polypropylene, etc.) Woven, knitted, plain weave, spun bond, and the like, and may further include natural fibers and / or synthetic fibers.

Preferably, the backside layer 11 can easily secure mechanical properties such as strength and flame retardancy, and has an advantage that a sewing performance and a clean appearance can be realized in relation to the foam layers 13b and 13b ' A woven fabric or a nonwoven fabric containing rayon and polyester in a weight ratio of 30-40: 60-70 can be used.

When the content of the polyester exceeds the above range, the flammability, the covering property and the workability are not good, and when the polyester content is less than the above range, the mechanical properties are deteriorated.

The backside layer 11 may have a coating layer formed on one side thereof to enhance the peeling strength of the backside layer 11 with respect to the foam layers 13b and 13b '.

Specifically, since the artificial leather according to the present invention sucks and embosses the emboss using the vacuum during the embossing step S13 described later, as in the case of embossing using the roller pressing type embossing roll, The peeling strength between the back layer 11 and the foam layers 13b and 13b 'may be reduced. Therefore, in order to increase the peeling strength of the back layer 11 according to the present invention, the coating solution is applied to one side of the back layer 11, and then the gel layer is subjected to heat treatment at 120-150 ° C. gelling to form a coating layer.

The coating solution may be an acrylic adhesive, a polyurethane adhesive, or a polyvinyl chloride plastisol. However, the acrylic adhesive has a disadvantage in that the hardness of the artificial leather is increased due to hardness after drying, and the polyurethane adhesive is relatively expensive and the material cost rises, preferably polyvinyl chloride plastisol.

The polyvinyl chloride plastisol may be formed by stirring 70 to 130 parts by weight of a plasticizer and 0.5 to 10 parts by weight of a curing agent at room temperature with respect to 100 parts by weight of a polyvinyl chloride resin.

Specifically, the polyvinyl chloride resin may be a mixed resin composed of 60-90% by weight of a homopolymer of vinyl chloride and 10-40% by weight of a copolymer of vinyl chloride and vinyl acetate.

The vinyl chloride homopolymer is a paste polyvinyl chloride resin prepared by emulsion polymerization and may be contained in the mixed resin in an amount of 60-90% by weight or 65-85% by weight. If it is less than the above range, the peeling strength between the backside layer 11 and the foam layer 13b or 13b 'is lowered. If it exceeds the above range, the backside layer 11 is not preferable.

The copolymer of vinyl chloride and vinyl acetate is a resin that imparts excellent adhesion to the backing layer 11, which is woven or nonwoven fabric, and the content of vinyl acetate in the copolymer may be 1-15% by weight or 3-10% by weight have. When the amount is less than the above range, the adhesive strength is lowered and the peel strength between the back layer 11 and the foam layers 13b and 13b 'is lowered. When the above range is exceeded, the hydrolysis resistance is lowered.

In addition, the copolymer of vinyl chloride and vinyl acetate may be contained in the mixed resin in an amount of 10-40 wt% or 15-35 wt%. If it is less than the above range, the peel strength of the backing layer 11 and the foam layer 13b or 13b 'is lowered. If the thickness is out of the above range, the mechanical properties such as heat resistance are lowered.

The plasticizer contained in the coating solution may be at least one selected from a phthalate plasticizer, a terephthalate plasticizer, a benzoate plasticizer, a citrate plasticizer, a phosphate plasticizer or an adipate plasticizer.

In the present invention, it is preferable to use a terephthalate plasticizer which is environmentally friendly and excellent in heat resistance. As the terephthalate-based plasticizer, for example, dioctyl terephthalate can be used, but is not limited thereto.

The plasticizer may be contained in an amount of 70-130 parts by weight or 80-120 parts by weight based on 100 parts by weight of the mixed resin. When the amount is less than the above range, the viscosity of the coating solution may be increased and the processability may be deteriorated. If the amount is more than the above range, the adhesive force may decrease due to migration of the plasticizer.

The curing agent contained in the coating solution may be a low-temperature curing type curing agent for enhancing energy efficiency and productivity, and a block isocyanate curing agent blocked with a blocking agent in part or all of the isocyanate group may be used.

The blocking agent may be selected from the group consisting of phenol, ε-caprolactam, methyl ethyl ketone oxime, 1,2-pyrazole, diethyl malonate, malonate, diisopropylamine, triazole, imidazole, and 3,5-dimethylpyrazole may be used as the starting material. .

The blocked isocyanate curing agent blocks the isocyanate group so that the isocyanate group (-NCO) does not react with the hydroxyl group (-OH) or the amino group (-NH) at room temperature. When the blocked isocyanate curing agent reaches a certain temperature region, And the curing reaction proceeds.

The dissociation temperature of the curing agent may be 100 ° C or higher or 110-130 ° C.

The curing agent may be added in an amount of 0.5-10 parts by weight or 1-5 parts by weight based on 100 parts by weight of the mixed resin. If it is less than the above range, the peeling strength between the backing layer 11 and the foam layers 13b and 13b 'is lowered due to the lowering of the degree of crosslinking. If the above range is exceeded, the unreacted curing agent remains impurities, Can be used within.

The coating solution may further optionally contain at least one other additive selected from the group consisting of a stabilizer, a filler, a pigment, a viscosity reducing agent and a dispersing agent. The content of the coating solution may be adjusted so long as it does not affect the physical properties of the coating solution There is no restriction.

The viscosity of the coating solution may be 80-140 seconds or 100-120 seconds at 25 ° C in the viscosity of cup (# 3 cup). If the amount of the coating solution is less than the above range, the coating solution may flow down to lower the coating efficiency. If the amount exceeds the above range, the coating solution may not be impregnated into the backing layer 11, And stable processability can be ensured.

The thickness of the coating layer formed on the backside layer 11 may be 1-10 占 퐉 or 2-5 占 퐉, for example. Here, the thickness of the coating layer refers to the thickness including the coating solution impregnated into the backside layer 11. When the thickness of the coating layer is less than the above range, the peel strength of the back layer 11 and the foam layers 13b and 13b 'decreases. When the thickness exceeds the above range, the microhardness of the artificial leather increases, So that it can be coated with a thickness within the above range.

When the coating layer is formed on one side of the backside layer 11, the peeling strength between the backside layer 11 and the foam layers 13b and 13b 'may be 2.5-6 kgf / 30 mm or 2.5-5.5 kgf / 30 mm. If it is less than the above range, the back layer 11 and the foam layers 13b and 13b 'are easily peeled off and the quality of the artificial leather is deteriorated. If it exceeds the above range, the microhardness is increased and the touch feeling is lowered. It is desirable to maintain the peel strength.

The thickness of the backside layer 11 may be 0.4-0.7 mm. If the thickness is less than the above range, the mechanical strength of the backside layer 11 may deteriorate. If the backside layer 11 is thicker than the above range, material cost may be increased.

Foam layer ( 13b, 13b ')

The foam layer 13b, 13b 'of the present invention imparts a soft characteristic and a cushioning feeling to the artificial leather, and can include 60-120 parts by weight of plasticizer and 5-15 parts by weight of the blowing agent, based on 100 parts by weight of the polyvinyl chloride resin have.

Specifically, the polyvinyl chloride resin may be a straight polyvinyl chloride resin formed by suspension polymerization capable of simultaneously securing excellent cushion feeling, high elongation and excellent durability.

The degree of polymerization of the polyvinyl chloride resin may be 900-1200, or 950-1150. If it is less than the above range, the durability is deteriorated. If it exceeds the above range, the hardness of the foam layers 13b and 13b 'becomes high and the cushion feeling is lowered, so that a polyvinyl chloride resin having a polymerization degree within the above range can be used.

The foaming layers 13b and 13b 'of the present invention are formed so that a copolymer of vinyl chloride and vinyl acetate is added in an amount of 5-20 (parts by weight) to 100 parts by weight of the polyvinyl chloride resin Or 5-15 parts by weight, and the peeling strength with the back layer 11 is excellent within the above range.

The content of vinyl acetate in the copolymer of vinyl chloride and vinyl acetate may be 0.5-10 wt% or 1-5 wt%.

Alternatively, the foam layers 13b and 13b 'of the present invention may be formed by selectively adding a thermoplastic polyurethane (TPU) resin, a polyvinylidene chloride (PVDC) resin, a polyvinylidene fluoride (PVDF) resin, a chlorinated poly One kind selected from the group consisting of polyvinyl chloride (CPVC) resin, polyvinyl alcohol (PVA) resin, polyvinyl acetate (PVAc) resin, polyvinyl butyrate (PVB) resin, polyethylene (PE) resin and polypropylene Or more.

The plasticizer may be at least one selected from the group consisting of a phthalate plasticizer, a terephthalate plasticizer and an epoxy plasticizer.

The phthalate plasticizer is a plasticizer having very good compatibility with the polyvinyl chloride resin. Examples of the plasticizer include phthalate plasticizers such as dibutyl phthalate, diethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate and butyl benzyl phthalate. However, diisodecyl phthalate, which is preferably a low volatile plasticizer, can be used.

The terephthalate plasticizer is an environmentally friendly plasticizer such as dioctyl terephthalate, but is not limited thereto.

The epoxy plasticizers are epoxidized double bonds of unsaturated fatty acid glycerol esters with hydrogen peroxide or peracetic acid, for example, epoxidized soybean oil or epoxidized linseed oil, but are not limited thereto.

The plasticizer may be used in an amount of 60-120 parts by weight, or 70-100 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin. If the amount is less than the above range, the processability and ductility are lowered, and the microhardness is increased. When the amount exceeds the above range, bleeding phenomenon of the plasticizer occurs.

The blowing agent is not particularly limited as long as it can form fine bubbles which give the foam layer 13b and 13b 'necessary elasticity and thickness. Examples of the blowing agent include azodicarbonamide (ADCA), p, p'-oxy A chemical foaming agent such as p-toluene sulfonyl hydrazide or sodium bicarbonate may be used as the organic solvent, for example, p, p'-Oxybis (benzenesulfonyl hydrazide), or the like.

The foaming agent may be used in an amount of 5-15 parts by weight, or 5-10 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin. If it is less than the above range, the ductility and cushioning feeling of the artificial leather deteriorates, and if it exceeds the above range, the foaming cells of the foam layers 13b and 13b 'are excessively generated to lower the surface physical properties and durability, .

The foam layers 13b and 13b 'may further include at least one selected from the group consisting of a heat stabilizer, a flame retardant, and a filler for controlling the melt strength and physical properties.

The foam layers 13b and 13b 'may have a foaming ratio of 100-500% or 150-300% after foaming at 220-230 ° C. If it is less than the above range, microhardness of the artificial leather is increased and it becomes hard. If it exceeds the above range, that is, when it is too much foamed The durability and the strength of the artificial leather are weakened and the physical properties are deteriorated. Therefore, it is preferable that the artificial leather has a foaming ratio within the above range.

The foam cells formed on the foam layers 13b and 13b 'may be spherical foam cells. The spherical foam cell is not necessarily a geometrically perfect spherical shape as it is distorted by the external pressure or is in contrast to the shape of the foam cell having a pointed shape. The spherical foam cell is generally referred to as spherical But also the level of inclusiveness. Therefore, in the present specification, it is to be understood that a spherical foam cell does not deform its shape due to a physical external force, but maintains a spherical shape at the time of formation.

The foamed cells may include 10-30 or 15-20 per 1 mm ² of the cross-section or flat cross-section of the foam layers 13b and 13b '. If it is less than the above range, the ductility and cushion feeling will be lowered. If it exceeds the above range, the surface durability will be lowered and the physical properties such as surface feeling and cushion feeling will decrease.

The number of foam cells is determined by dividing the number of foam cells formed on the end face of the foam layer 13b or 13b 'or the unit area of 1 mm ² of the flat face by an optical microscope after cutting the artificial leather in the vertical direction or the horizontal direction Respectively.

The average diameter of the foamed cells may be 120-250 占 퐉, or 135-200 占 퐉. The average diameter represents an average value of the diameter of one foam cell. More specifically, when the foam cell is geometrically spherical, it means an average diameter. In the case of a shape other than a geometric sphere, And the average length of the axis.

The average diameter of the foam cells satisfies the above range, and by maintaining the shape of the sphere, the artificial leather can secure high ductility and workability, and can exhibit excellent cushioning feeling.

The average diameter of the foamed cell in the after cutting the artificial leather in the vertical direction or the horizontal direction, an optical microscope an average diameter of the foamed cells formed in the foam layer (13b, 13b ') per unit area of 1mm ² of the end face or flat cross-section Scale bar.

The specific gravity of the foam layers 13b and 13b 'may be 0.7-0.9 or 0.7-0.8. If it is less than the above range, the durability is deteriorated. If the above range is exceeded, the ductility and cushion feeling may be deteriorated.

That is, the foam layers 13b and 13b 'are formed such that the spherical foam cells do not deform the structure due to the external pressure, and the foam cells include 10-30 per 1 mm 2 unit area of the cross- And the specific gravity is 0.7-0.9. Thus, the artificial leather can be remarkably improved in cushioning feeling and smooth surface feeling.

The foam layers 13b and 13b 'may have a thickness of 0.4-0.8 mm or 0.4-0.7 mm. If the thickness is less than the above range, the cushion feeling may be deteriorated. If the thickness exceeds the above range, Can take a lot of time.

Skin layer (15)

The skin layer 15 of the present invention is intended to ensure smoothness of the surface and to realize hue. The skin layer 15 may include 60-120 parts by weight of a plasticizer and 100 parts by weight of a pigment, based on 100 parts by weight of the polyvinyl chloride resin.

It is preferable that the polyvinyl chloride resin contained in the skin layer 15 has a degree of polymerization higher than that of the polyvinyl chloride resin used for the foam layers 13b and 13b ' It is possible to prevent the skin layer from popping out during step S13.

Specifically, the polyvinyl chloride resin contained in the skin layer 15 may be a straight polyvinyl chloride resin formed by suspension polymerization.

The polyvinyl chloride resin may have a degree of polymerization of 1250-3000, or 1250-2000. If it is less than the above range, the skin layer 15 may burst during the foaming molding step (S8) or the embossing step (S13) which will be described later. If it exceeds the above range, the surface feeling and ductility are lowered, Polyvinyl chloride resin can be used.

The skin layer 15 may further include at least one selected from the group consisting of heat stabilizers, flame retardants, and fillers for controlling the melt strength and physical properties.

The plasticizer, heat stabilizer, flame retardant, filler, etc. contained in the skin layer 15 may be the same as the foam layers 13b and 13b '.

The thickness of the skin layer 15 may be 100-300 占 퐉 or 120-200 占 퐉. When the amount is less than the above range, the surface smoothness and workability are lowered. In addition, the material cost is increased due to an increase in the amount of pigment added to realize the color, and when it exceeds the above range, the cushioning feeling of artificial leather is lowered, Can take a lot of time.

Surface treatment layer (17)

The surface treatment layer 17 of the present invention may be formed by applying and drying an aqueous surface treatment agent on the skin layer 15.

Wherein the aqueous surface treatment agent comprises at least one member selected from the group consisting of a main component (A); (B) a curing agent comprising at least one functional group selected from the group consisting of an aziridine group, an isocyanate group, and a carbodiimide group per molecule; Aqueous solvent (C); And a silicone compound (D).

More specifically, the theme (A) is as follows.

Topic (A-1)

For example, the subject (A-1) in the present invention may be one in which a polyurethane having at least one functional group selected from the group consisting of a carboxylic acid group, a hydroxyl group, an amino group and a combination thereof per molecule is dispersed in an aqueous solvent .

As a method for producing a polyurethane having a carboxylic acid group in the polyurethane, for example, a method in which a compound having a carboxylic acid group is used as a raw material in the urethane formation reaction can be mentioned. Examples of the compound having a carboxylic acid group used as a raw material of the polyurethane include 2,2'-dimethylolpropionic acid, 2,2'-dimethylolbutanoic acid, 2,2'-dimethylolbutyric acid, 2,2'-dimethyl And allpentanoic acid.

Examples of the method for producing a polyurethane having a hydroxy group in the polyurethane include a method of reacting an excessive amount of a polyol and / or a glycol with a polyisocyanate to obtain a polyurethane having a hydroxy group at the terminal. Examples of the compound having a hydroxy group used as a raw material of the polyurethane include polyester polyol, polyether polyol, polycarbonate polyol, polyacetal polyol, polyacrylate polyol, polyester amide polyol, polythioether polyol, polybutadiene , And the like.

On the other hand, as a method for producing a polyurethane having an amine group in the polyurethane, for example, an amino alcohol such as 2-aminoethanol, 2-aminoethylethanolamine or diethanolamine, aminophenol or the like is reacted with a urethane prepolymer at the terminal of the isocyanate group To obtain a polyurethane having an amine group.

The polyurethane may preferably be a polycarbonate-based polyurethane which uses the polycarbonate polyol having excellent heat resistance and light resistance as a raw material.

In the present invention, the polyurethane content in the subject (A-1) may be 5-30% by weight, or 10-25% by weight. When the content of the polyurethane in the subject (A-1) is less than the above range, the touch feeling, scratch resistance, light resistance, heat resistance, abrasion resistance and solvent resistance are lowered. When the content exceeds the above range, whitening phenomenon and appearance unevenness occur, .

The whitening phenomenon refers to a white dot defect of a white dot appearing in the middle of the surface of the artificial leather after application of the aqueous surface treatment agent.

Topic (A-2)

As another example, the subject matter (A) may be an acrylic-modified polyurethane further containing acrylate in the main chain dispersed in an aqueous solvent.

The acrylic-modified urethane content in the subject (A-2) may be 1-10% by weight, or 2-8% by weight. When the content of the acryl-modified urethane in the subject (A-2) is less than the above range, the stain resistance and touch feeling slip, and when the content exceeds the above range, the ductility is lowered and the touch feeling is dry, .

On the other hand, the above-mentioned subject (A-2) may further include a siloxane for facilitating water dispersion of the acrylic-modified polyurethane and improving antifouling property.

Preferably, the siloxane contains at least one methyl group to secure the antifouling property, and it is possible to ensure excellent compatibility with the acryl-modified polyurethane and excellent hardness.

The siloxane may be included in the subject (A-2) in an amount of 0.01 to 2% by weight, or 0.05 to 1.5% by weight. When the amount is less than the above range, the antifouling property is lowered. When the amount exceeds the above range, the siloxane is transferred to the surface and the surface of the artificial leather becomes excessively glossy. When the surface of the artificial leather is rubbed by hand, siloxane appears, . ≪ / RTI >

Topic (A-3)

As another example, the theme (A) of the present invention may be a mixture of the theme (A-1) and the theme (A-2).

The subject matter (A-1) and the subject matter (A-2) may be mixed at a weight ratio of 1: 9-4: 6 or 2: 8-3: 7. When the subject (A-1) is less than the above range, the surface texture of the artificial leather is not smooth and the antifouling property of the subject (A-1) exceeding the above range is lowered.

The curing agent (B)

The curing agent (B) may contain, per molecule, at least one functional group selected from the group consisting of an aziridine group, an isocyanate group, and a carbodiimide group.

Specifically, the compound having an aziridine group refers to a compound containing a heterocyclic tricyclic ring composed of two carbon atoms and one nitrogen atom, and includes 3- (3-methoxyphenyl) -3- (trifluoromethyl) 3- (3-methoxyphenyl) -3-trifluoromethyl) -diaziridine); 3- (trifluoromethyl) -3-phenyldiaziridine (3- (trifluoromethyl) -3-phenyldiaziridine); Propane-2,2-diyldi zenzene-4,1-diyl diaziridine-1-carboxylate; 1,1 '- (butylphosphoryl) diaziridine; 1,1' - (butylphosphoryl) diaziridine; Oxydiethane-2,1-diyldiaziridine-1-carboxylate; oxydiethane-1, < / RTI > 3,3-bis (1,1-difluorohexyl) - [1,2] diaziridine; 3,3-bis (1,1-difluoro-hexyl) - [1,2] diaziridine; 1-Aziridinepropanoicacid; Methyl-2 - [[3- (2-methyl-1-azidinyl) -1-oxopropoxy] (2-methyl-1-aziridinyl) -1-oxopropoxy] methyl] -1,3-propanediol; 2 - [[3- (2-methyl-1-aziridinyl) -1-oxopropoxy] methyl] -1,3-propanediyl ester (2-methyl-1-aziridinyl) -1-oxopropoxy] methyl] -1,3-propanediol; (2-methyl-1-aziridinyl) -1-oxopropoxy] methyl] -1,3-propanediylbis (2-ethyl-2 - [[3- (2-methyl-1-aziridinyl) -1-oxopropoxy] methyl] -1,3-propanediylbis (2-methyl-1-aziridinepropanoate); Pentaerythritol tris [3- (1-aziridinyl) propionate], pentaerythritol tris (3-aziridinyl) propionate] 3-aziridinopropionate)), and combinations thereof.

The isocyanate group-containing compound is, for example, selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate, modified diphenylmethane diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate, lysine isocyanate, cyclohexane diisocyanate, -Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate, methylenediphenyl isocyanate, xylene diisocyanate, tetramethyl xylene diisocyanate, norbornene diisocyanate, triphenyl methane triisocyanate, poly Phenylpolymethylene polyisocyanate, polyisocyanate containing carbodiimide group, polyisocyanate containing allophanate group, polyisocyanate containing isocyanurate group, and It may include one or more selected from the group consisting of the combination.

The compound having the carbodiimide group may be a polycarbodiimide.

The curing agent (B) may be contained in an amount of 1-25 parts by weight, 5-20 parts by weight or 10-20 parts by weight based on 100 parts by weight of the main component (A). When it is contained in the above range, it is not cured and physical properties such as light resistance, heat resistance, scratch resistance, abrasion resistance, solvent resistance and hydrolysis resistance are lowered. Mix within range.

Aqueous solvent (C)

The aqueous solvent (C) may be water or an alcohol or a mixture of water and an alcohol.

The alcohol may be at least one selected from the group consisting of alcohols such as methanol, ethanol, propanol, butanol, and the like. Due to the alcohol, stability of the reaction during mixing of the components constituting the aqueous surface- And the stability of the treating agent is ensured.

Due to the aqueous solvent (C), an interpenetrating polymer network in which the subject (A) and a curing agent not participating in the three-dimensional crosslinking reaction are intertwined can be formed, and volatile organic compounds It is possible to reduce the generation of odorous substances depending on the substances (VOCs).

The aqueous solvent (C) may be contained in an amount of 1-25 parts by weight, 5-20 parts by weight, or 10-20 parts by weight based on 100 parts by weight of the subject (A).

The silicone compound (D)

The silicone compound (D) may be in the form of a liquid in which the polysiloxane is dispersed in water or may be a polysiloxane in the form of beads, but may be in the form of a liquid, preferably dispersed in water having a better surface feel.

The content of the polysiloxane in the liquid silicone compound may be 5-30 wt%, or 10-20 wt%.

The silicone compound (D) may be contained in an amount of 1-15 parts by weight, 1-10 parts by weight or 5-7 parts by weight based on 100 parts by weight of the main component (A).

When the content of the polysiloxane in the silicone compound and the content of the silicone compound mixed with the subject are less than the above range, the antifouling property is lowered. When the amount exceeds the above range, the surface feeling is excessively slipped and the Squeak index can be minimized. The coefficient is not satisfied and the seizure feeling is not good, so that it can be used within the above content range.

additive

The aqueous surface treatment agent may further include a defoaming agent and a leveling agent.

The antifoaming agent may be selected from a silicone resin, a surfactant, a paraffin wax or a mineral oil to prevent a large number of air bubbles from being generated due to the high viscosity of the aqueous surface treating agent as compared with the oil surface treatment agent. Do not.

The antifoaming agent may be contained in an amount of 0.1-0.5 parts by weight based on 100 parts by weight of the subject matter (A), and has excellent coating properties and physical properties within the above range.

The leveling agent is added so that the surface coating can be made uniform, and may be selected from silicone resin or acrylic resin, but is not limited thereto.

The leveling agent may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the main component (A), and has excellent coating properties and physical properties within the above range.

The aqueous surface treatment agent of the present invention may optionally further include at least one member selected from the group consisting of urethane beads, acrylic beads and fluorine-containing waxes.

The antifouling property can be realized by hydrophobicity by further including at least one member selected from the group consisting of urethane beads, acrylic beads and fluorine-containing wax, and the surface tension of the aqueous surface treatment agent is reduced, .

At least one member selected from the group consisting of urethane beads, acrylic beads and fluorine-containing wax may be contained in the aqueous surface treatment agent in an amount of 1-10% by weight, more preferably 2-5% by weight. The inclusion of at least one member selected from the group consisting of urethane beads, acrylic beads and fluorine-added waxes within the above ranges can lower the occurrence of problems of dyes and other substances being adhered to the aqueous surface treatment agent, It can be easily implemented.

Further, depending on the role of the aqueous surface treatment agent, it may further include at least one selected from the group consisting of a surfactant, a cosolvent, a modifier, a quencher, a gloss enhancer, a thickener and a quencher, And is not particularly limited.

The viscosity of the aqueous surface treatment agent having the above composition may be 150-700 cps or 200-600 cps at 25 ° C. If it is less than the above range, the texture of the artificial leather will not become smooth and relatively stiff, And if it exceeds the above range, gravure coating is not possible, so that it is possible to have a viscosity within the above range.

The viscosity of the aqueous surface treatment agent is higher than that of the conventional oily surface treatment agent, and the coating of the upper part of the skin layer is effected with high viscosity.

The aqueous surface treatment agent may be prepared by (a) adding the curing agent (B) to the aqueous solvent (C) followed by stirring; (b) adding the mixture stirred in step (a) to the subject (A) and stirring the mixture; Based on the total weight of the composition.

Since the subject (A), the curing agent (B), and the aqueous solvent (C) are the same as those described above, duplicated description is omitted.

The step (a) may be a step of stirring at 20-25 ° C for 40 minutes-5 hours, or for 1-3 hours.

In the step (a), the aqueous solvent (C) and the curing agent (B) are not sufficiently stirred when stirring is carried out for less than the time, and then the unreacted curing agent B) rapidly reacts with the subject (A) to cause a shocking phenomenon, resulting in a decrease in surface cross-link density and workability, and a whitening phenomenon on the surface of artificial leather.

Further, when the aqueous solvent (C) is added to the curing agent (B), the viscosity of the resin increases rapidly at an early stage, and the surface cross-link density is lowered. It is preferable to add the curing agent (C) to the aqueous solvent (C).

The step (b) may be a step of stirring at 20-25 ° C for 0.2-1 hours, or for 0.3-0.8 hours.

The aqueous surface treatment agent prepared as described above can be obtained by adding a curing agent (B) to the water-based solvent (C), stirring it sufficiently and then mixing with the subject (A) The hardening agent not participating in the bonding reaction can form an interpenetrating polymer network intertwined with each other, so that the antifouling property and surface cross-linking density of the surface treatment layer can be increased and the surface tension can be lowered.

The surface cross-linking density of the surface treatment layer 17 of the present invention formed using the above-mentioned aqueous surface treatment agent is 70-98% or 75-95%, thereby securing the surface cross-linking density within the above range, And can have excellent antifouling property.

In addition, the surface tension of the surface treatment layer 17 is 90-130 or 95-120, and the surface tension of the surface treatment layer 17 is maintained to be superior to that of the surface treatment layer formed of an oil-based surface treatment agent.

The surface treatment layer 17 may have a thickness of 4-30 탆 or 10-20 탆. By keeping the thickness of the surface treatment layer 17 within the above-mentioned range, the stain resistance can be secured simultaneously while maintaining the flexibility of the artificial leather. When the thickness is less than the above range, the thickness is too thin and durability is deteriorated. If it exceeds the above range, the material cost may be increased due to an increase in the requirement of the aqueous surface treatment agent.

The artificial leather of the present invention including the surface treatment layer 17 as described above has a Squeak index of less than 0.15 and a dynamic friction coefficient of 0.2 to 0.5, and can satisfy both the Squeak index and the dynamic friction coefficient.

Specifically, the Squeak index is a numerical value of the noise generated in the friction between the artificial leather and the human body, that is, the occupant. The artificial leather of the present invention satisfies the above range with the Squeak Index less than 0.15 or 0.14 or less, And the touch is soft. If the Squeak index exceeds the above range, the Squeak index may be within the above range because noise is strong and the stick slip characteristic, which is a friction phenomenon accompanying vibration, is strong.

The Squeak index was obtained by superimposing artificial leather specimens on top of each other with a universal testing machine and pushing it at a force of 4.5 Kg and measuring the deviation of force (DELTA F) and the average force (Fa ) Was calculated and calculated as? F / Fa.

The coefficient of dynamic friction (μ) is used to make slippability when an object moves while sliding on another object. The artificial leather of the present invention may have a coefficient of dynamic friction of 0.2-0.5 or 0.25-0.5. If it is less than the above range, the slipperiness can not be ensured and the seizure feeling is not good. If it exceeds the above range, the Squeak index increases due to friction between the artificial leather and the occupant, so that the coefficient of dynamic friction may be within the above range.

The coefficient of dynamic friction was calculated as Fa / W by measuring the average force (Fa) necessary to pull the artificial leather specimens up and down at a speed of 300 mm / min with a weight of 4.5 kg (W) .

The synthetic leather of the present invention including the surface treatment layer 17 as described above may have a volatile organic compound generation amount of 500 μg / m 2 or less or 400 μg / m 2 or less. The lower limit of the artificial leather may be 0 μg / There is an eco-friendly effect within the above range.

The volatile organic compound means a hydrocarbon compound that easily evaporates into the atmosphere to generate odor or ozone. The amount of the generated volatile organic compound is determined by preparing a test piece of artificial leather, placing the test piece in a 4 L glass desicator The sample was heated in an oven for 2 hours, and then allowed to stand in a laboratory of 25 ° C for 1 hour. The lid of the desiccator was opened for about 3 cm to 4 cm, and volatile organic compounds emitted from the specimen were collected, Measured by instrument.

The artificial leather of the present invention including the surface treatment layer 17 as described above may have an antifouling property of less than 10% or not more than 7%, and the lower limit thereof is not limited but is more than 1% or 2% And has an excellent resistance to contamination.

Embo (19)

The embossment 19 is formed by vacuum on the skin layer 15 and the surface treatment layer 17 by vacuum. More specifically, the embossment 19 may be concave and convex formed on the uppermost part of the artificial leather.

The difference in thickness between the valley 19a of the emboss 19 of the artificial leather of the present invention and the surface treatment layer formed on the crest 19b may be less than 5 mu m or 3 mu m or less, The ratio of the thickness of the surface treatment layer formed on the floor 19b of the emboss 19 to the thickness of the surface treatment layer formed on the trough 19a of the emboss 19a The thickness of the surface treatment layer) may be 0.7-1 or 0.8-1, and the surface treatment layer formed on the floor and the floor may have a slight difference in gloss within the above range so that the surface does not appear mottled. There is an effect that can be done.

The area where the ratio of the thickness of the surface treatment layer formed on the troughs 19a of the embossing 19 to the floor 19b satisfies the above range is 80% or more or 90% or more of the entire surface of the artificial leather. Or more.

In the present invention, the valley of the embossment is a recessed concave portion of the concave and convex portion, which means the lowest point, and the crest of the embossed portion is a convex convex portion, (See FIG. 4).

The thickness of the surface treatment layer formed on the trough 19a and the floor 19b of the embossment 19 can be measured using a high magnification optical microscope after cutting the artificial leather in the vertical direction.

On the other hand, referring to FIG. 2,

(S1) a backside layer preparation step of preparing a backside layer which is a woven or nonwoven fabric;

A prefoamed or foamed layer and a skinned layer (S3) for forming a prefoamed or foamed layer and a skinned layer, respectively;

A backside layer stacking step (S5) of stacking the backside layer on the bottom surface of the prefoamed or foamed layer;

A skin layer laminating step (S7) of laminating the skin layer on the prefoamed or foamed layer on which the backside layer is formed;

(S9) forming a surface treatment layer by coating an aqueous surface treatment agent on the skin layer to form a surface treatment layer;

An infrared ray irradiation step (S11) of irradiating infrared rays onto the surface treatment layer;

And an embossing step (S13) of sucking and embossing the emboss using a vacuum on the skin layer and the surface treatment layer heated by the infrared ray irradiation,

The artificial leather has a microhardness of 45-59,

The minute hardness was measured immediately after the needle contacted the artificial leather at a pressing speed of 1 mm / s in a peak hold mode using a microhardness tester (Asker Micro Durometer, model: MD-1 CAPA) And the maximum value at 1 s is measured.

In the step (S1), one side of the backside layer 11 may be coated with a coating solution. Specifically, this may be done by coating one side of the backside layer 11 with a coating solution to increase the peeling strength between the backside layer 11 and the foam layers 13b and 13b 'on the backside layer 11 .

Other features of the coating solution for coating the backing layer 11 and one side thereof are the same as those described above, so the overlapping description is omitted.

The step (S3) may be a step of extruding or calendering the prefoamed foam layer 13a or the foamed layer 13b and the skin layer 15.

The extrusion molding may be a T-die extrusion process using a T-die extruder after melting the prefoamed or foamed layer and the composition for preparing the skin layer, respectively, in an extruder, and the calendered molding is carried out using the pre- And the composition for preparing the skin layer are kneaded in a mixer, respectively, and then passed through a calender roll at 160 to 170 ° C.

Specifically, the pre-foamed layer 13a is formed into a sheet shape by extrusion molding or calendering, and then foamed in a foam molding step S8 to form a foamed layer 13b ' The layer 13a may have a thickness of 0.2-0.35 mm or 0.25-0.3 mm.

The foam layer 13b is formed into a sheet shape by extrusion molding or calendering, and is then passed through an oven at 220-260 ° C to complete foaming.

The composition for preparing the prefoamed layer or the foamed layer is the same as the composition of the foamed layer described above, so duplicate description is omitted.

Since the composition for preparing the skin layer is the same as the composition of the skin layer described above, the overlapping description is omitted.

The step (S5) may be a step of hot-laminating the back layer 11 on the bottom surface of the pre-foamed layer 13a or the foamed layer 13b.

The step (S7) may be a step of forming a semi-finished product by hot-laminating the skin layer 15 on the pre-foamed layer 13a or the foamed layer 13b in which the back layer 11 is laminated.

More specifically, the back layer 11 coated with one side is laminated on the bottom surface of the pre-foam layer 13a or the foam layer 13b, and the pre-foam layer 13a or the foam layer 13b, The reason why the skin layer 15 is laminated on the upper portion 13b is that the back layer 11 has excellent mechanical strength and each layer holds the physical properties in the process. If the pre-foamed layer 13a or the foamed layer 13b and the skin layer 15 are first laminated, bending of the two layers 13a / 13b and 15 during thermal lamination, or curling such as bending of the layer It is possible to preferentially heat-laminate the back layer 11 having excellent mechanical strength on the bottom surface of the pre-expanded layer 13a or the foam layer 13b.

If the prefoamed foam layer 13a is used in step (S7), the prefoamed foam layer 13a is passed through the oven at 220-230 ° C and foamed after the step (S7) to form a backing layer 11; A foam layer 13b '; And a foaming molding step (S8) of forming a semi-finished product in which the skin layer 15 is laminated.

In the step (S9), a surface treatment layer is formed by applying and drying an aqueous surface treatment agent on the skin layer of the semi-finished product, and may be a single layer or a multilayer coating of two or more layers.

In the case of coating with the single layer, the above-described aqueous surface treatment agent may be applied. In the case of multi-layer coating, a composition excluding the silicon compound in the aqueous surface treatment agent described above may be applied to the base. An aqueous surface treating agent such as one can be applied.

The drying may be performed at 110-150 ° C or 130-150 ° C for 80-120 seconds. If the drying temperature is less than the above temperature and time range, the aqueous solvent remains not evaporated. As a result, the surface of the artificial leather is whitened due to the uncured state, and the surface properties of the artificial leather are lowered. So that it can be dried within the temperature and time range within the above range.

Since the structure of the surface treatment layer 17 is the same as that described above, the overlapping description is omitted.

The step (S11) may include irradiating the surface of the semi-finished product having the surface treatment layer formed in step (S9) with infrared rays at 150 to 180 DEG C for 5 to 15 seconds or 10 to 15 seconds. When the infrared ray is irradiated at less than the above temperature and time, the skin layer 15 is not softened, so embossing is not performed well in the embossing step S13 to be described later. When infrared rays are irradiated over the temperature and time, The infrared ray 15 can be melted and the infrared ray can be irradiated within the time.

In step S11, the process speed may be 10-20 m / min or 12-15 m / min. For example, when the process speed is 15 m / min, infrared may be irradiated for 14 seconds.

The step (S13) may be carried out under a vacuum of 0.02-0.08 MPa or 0.04-0.07 MPa in the step of adsorbing and embossing the embossment 19 using vacuum. When the step is performed at a pressure lower than the vacuum pressure range, it is difficult to form the embossment 19, and the cushion feeling may be deteriorated. If the step is performed in excess of the above range, the surface treatment layer 17 may be damaged, It can be performed within the pressure range of the vacuum system.

The step (S13) may be performed at a temperature of 150-190 DEG C or 160-180 DEG C. It is difficult to sufficiently form the embossing 19 when the process is performed at a temperature lower than the above temperature range. When the process is performed above the above range, the surface properties of the artificial leather are rough or torn due to high temperature, Can be performed.

The artificial leather manufacturing method according to the present invention may optionally include the in-line foam molding step (S8), the surface treatment layer forming step (S9), the infrared irradiation step (S11), and the embossing step (S13).

Alternatively, instead of applying the surface treatment agent to the upper surface of the skin layer 15 of the semi-finished product to form the surface treatment layer, the surface treatment layer forming step may be performed by irradiating infrared rays (S9 ') onto the skin layer 15 of the semi-finished product The emboss 19 is suction-molded (S11 ') on the surface of the skin layer 15 of the heated semi-finished product by vacuum, and then the surface treatment agent is applied to form the surface treatment layer 17 (S13' (See Fig. 3).

The artificial leather of the present invention has an effect of having a texture similar to that of natural leather and a soft touch.

The artificial leather of the present invention can realize an effect of excellent peel strength.

In addition, the artificial leather of the present invention can prevent the foamed cell constituting the foamed layer from being crushed or broken, thereby realizing an excellent cushioning effect.

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 scope and spirit of the invention as disclosed in the accompanying claims. Changes and modifications may fall within the scope of the appended claims.

[ Example ]

1. Manufacture of artificial leather

< Example  1>

(1) In the backside layer 11,

1) Preparation of coating solution

Paste 100 parts by weight of a mixed resin consisting of 75% by weight of a vinyl chloride homopolymer and 25% by weight of a copolymer of vinyl chloride and vinyl acetate (vinyl acetate content: 6% by weight), 100 parts by weight of a plasticizer and 3 parts by weight of a curing agent The coating composition was thoroughly stirred at room temperature to prepare a coating solution having a cup viscosity (Zahn cup, # 3 cup) at 25 캜 for 110 seconds.

2) cotton and polyester 35: 65 was coated with a coating solution prepared as described above by a gravure coating method to a thickness of 3 쨉 m, followed by gelling by applying heat at a temperature of 130 캜 A backside layer having a thickness of 0.6 mm is prepared.

(2) The pre-foamed layer 13a

10 parts by weight of a copolymer of vinyl chloride and vinyl acetate (vinyl acetate content: 3% by weight), 85 parts by weight of a plasticizer, 6 parts by weight of a blowing agent, 2 parts by weight of a heat stabilizer The kneaded composition for kneading the foamed layer was kneaded, and the kneaded raw material was passed through a calender roll at 160 to 170 DEG C to prepare a prefoamed layer (13a) having a thickness of 0.3 mm.

(3) Skin layer (15)

A composition for preparing a skin layer containing 95 parts by weight of a plasticizer, 2 parts by weight of a pigment and 2 parts by weight of a heat stabilizer was kneaded with respect to 100 parts by weight of a straight polyvinyl chloride having a degree of polymerization of 1,300, and the kneaded raw material was passed through a calender roll To prepare a skin layer having a thickness of 150 mu m.

Next, the skin layer 15 is laminated on the upper part of the pre-foamed layer 13a having the backside layer 11 laminated after the backside layer 11 coated with one side is laminated on the bottom face of the prefoamed foam layer 13a, Respectively.

Next, the backside layer (11); A pre-foamed layer 13a; A backing layer 11 by passing the semi-finished product having the skin layer 15 thereon through an oven at 220 캜 to foam the pre-expanded foam layer 13a; A foam layer 13b '; And the skin layer 15 was laminated on the surface of the substrate.

(4) Surface treatment layer (17)

First, 5 parts by weight of a curing agent containing hexamethylene diisocyanate and polyisocyanate as a curing agent is added to 20 parts by weight of an aqueous solvent containing 15 parts by weight of water and 5 parts by weight of isopropyl alcohol, followed by stirring at 25 DEG C for 1 hour.

Specifically, 5 parts by weight of a silicone compound containing 75% by weight of water and 15% by weight of polysiloxane, 0.2 part by weight of a defoaming agent and 2 parts by weight of a leveling agent as a main component Was added to 100 parts by weight of a polycarbonate-based polyurethane resin containing 50% by weight of water and 20% by weight of polyurethane.

Subsequently, 25 parts by weight of the mixture of the curing agent and the aqueous solvent was added to the mixture of the subject and the additive, followed by stirring at 25 DEG C for 0.5 hour to prepare an aqueous surface treatment agent.

Then, the aqueous surface treatment agent was gravure-coated on the skin layer 15, followed by drying at 140 캜 to evaporate the aqueous solvent to form a surface treatment layer 17 having a thickness of 15 탆.

Then, from the bottom to the top, the backside layer 11; A foam layer 13b '; A skin layer 15; The surface of the semi-finished product on which the surface treatment layer 17 was formed was irradiated with infrared rays at 150-180 캜 for 14 seconds and heated to about 170 캜.

(5) Embossing (19) Forming

The emboss 19 was adsorbed and formed on the surface of the skin layer 15 and the surface treatment layer 17 under a vacuum pressure of 0.06 Mpa to complete the production of the artificial leather according to the present invention.

< Example  2>

An aqueous surface treatment agent was prepared by the same composition and manufacturing method as in Example 1, except that a polycarbonate-based polyurethane resin containing 60% by weight of water, 7% by weight of acrylic modified urethane and 0.15% by weight of siloxane was used as a subject A synthetic leather was prepared in the same manner as in Example 1, except that the surface treatment layer was formed using the aqueous surface treatment agent.

< Example  3>

Except that a polycarbonate-based polyurethane resin in which the subject of Example 1 and the subject of Example 2 were mixed in a weight ratio of 2: 8 was used as the base material and the same composition and manufacturing method as in Example 1, A synthetic leather was prepared in the same manner as in Example 1, except that the surface treatment layer was formed using the aqueous surface treatment agent.

< Comparative Example  1>

In Example 1, infrared radiation was irradiated after the foam molding step (S8), roll pressing was carried out under pressure of 4 Mpa using an embossing roll having an emboss pattern on the surface of the heated skin layer 15 to form an embossing, Artificial leather was produced in the same manner as in Example 1, except that an aqueous surface treatment agent was applied to the surface of the skin layer 15 to form a surface treatment layer.

< Reference Example  1>

Artificial leather was produced in the same manner as in Example 1, except that one side of the backing layer 11 was not coated with a coating solution in Example 1.

< Reference Example  2>

A synthetic leather was prepared in the same manner as in Example 1, except that the pre-foamed layer (13a) in Example 1 did not contain a copolymer of vinyl chloride and vinyl acetate.

< Reference Example  3>

The polyvinyl chloride resin contained in the pre-foamed layer 13a in Example 1 had a degree of polymerization of 1300 and a polyvinyl chloride resin having a degree of polymerization of 1500 as the polyvinyl chloride resin contained in the skin layer 15 , Artificial leather was produced in the same manner as in Example 1.

< Reference Example  4>

Artificial leather was produced in the same manner as in Example 1, except that a polyvinyl chloride resin having a degree of polymerization of 900 was used as the polyvinyl chloride resin contained in the skin layer 15 in Example 1.

< Reference Example  5>

Except that the skin layer was an oily surface treatment agent containing 95 wt% of urethane acrylate as a surface treatment agent and 5 wt% of methylene dicyclohexyl diisocyanate as a curing agent, Artificial leather was produced.

< Reference Example  6>

A synthetic leather including a surface treatment layer was prepared in the same manner as in Example 1, except that the silicone compound (D) content in the aqueous surface treatment agent was 0.5 parts by weight based on 100 parts by weight of the main component (A).

< Reference Example  7>

A synthetic leather including a surface treatment layer was prepared in the same manner as in Example 1, except that the silicone compound (D) content in the aqueous surface treatment agent was 20 parts by weight based on 100 parts by weight of the main component (A).

< Reference Example  8>

A synthetic leather including a surface treatment layer was prepared in the same manner as in Example 1 except that the aqueous surface treatment agent was coated on the skin layer and then the infrared ray irradiation was not performed.

< Reference Example  9>

A synthetic leather including a surface treatment layer was prepared in the same manner as in Example 1, except that the curing agent (B) was added to the aqueous solvent (C) during the production of the aqueous surface treatment agent and the mixture was stirred at 25 캜 for 0.5 hour.

< Reference Example  10>

A synthetic leather containing a surface treatment layer was prepared in the same manner as in Example 1 except that an aqueous solvent (C) was added to the curing agent (B) in the production of the aqueous surface treatment agent.

< Reference Example  11>

A synthetic leather including a surface treatment layer was prepared in the same manner as in Example 1 except that the aqueous surface treatment agent was coated on the skin layer and dried at 100 ° C.

< Reference Example  12>

Except that the silicone compound (D) in the aqueous surface treatment agent was not contained, Artificial leather was produced.

2. Measurement of physical properties of artificial leather

(1) The micro hardness, peel strength, softness, sensibility (touch feeling), lubrication degree of the artificial leather of Example 1, Comparative Example 1 and Reference Example 1-4, The surface appearance was measured and the results are shown in Table 1 below.

- Micro hardness

The microhardness was measured immediately after the needle contacted the artificial leather at a pressing speed of 1 mm / s in peak hold mode using a micro-hardness tester (Asker Micro Durometer, model: MD-1 CAPA) The maximum value was measured.

- Peel strength

A specimen having a width of 30 mm and a length of 150 mm was prepared from the artificial leather prepared in the above step 1, five samples were taken in each of the transverse direction and the longitudinal direction, and the bubble side was impregnated with a solvent such as methyl ethyl ketone (MEK) (Foam layer) and air bubbles (back layer) are forcedly peeled by a length of 50 mm in parallel with the short side, taking care not to apply stress to the bubbles.

After the peeling, the test piece was allowed to stand in the room for 2 hours or more, the solvent was sufficiently volatilized, and the peeled skin (foam layer) and bubbles (back layer) were fixed to the clamp of the tensile tester and then peeled off at a rate of 200 mm / min Is obtained as an average value of the maximum value.

The test results are the average of five specimens.

- Ductility

5 pieces of artificial leather specimens having a pi (pi) of 100 mm were prepared by using a softness measuring instrument (SDL Atlas, ST300D) at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5% Measurements were made by reading the numerical value of the scale moved for 15 seconds by pushing it with the instrument.

- Sensibility ( touch feeling )

In-house experts on artificial leather evaluated their relative softness by hand touching.

(Ⓞ very soft, 부드러운 soft level, △ plain touch).

- Lecture

For the lecture, take 5 pieces of artificial leather with width of 250mm and length of 200mm in each of the horizontal and vertical directions, and set the short side to the SCALE baseline (A) on the horizontal stand.

Next, the specimen is pressed with a pressing plate of the same size as the specimen and slid at a speed of about 10 mm / sec in the direction of the slope, and the position (B) of the other end when the one end of the specimen comes into contact with the slope is read as SCALE .

The lecture figure is represented by the moving distance (scale of point B) (mm), and five surface and back surface in both length and width are measured and shown with their average value.

- Skin layer Bursting degree

After foaming the semi-finished product, the extent of skin layer breakage was visually confirmed.

(The breakdown, ○ partially broken, and not broken).

- Surface appearance

1) The artificial leather was cut in the vertical direction, and the thickness of the surface treatment layer formed on the embossed bone and floor was measured using a high magnification optical microscope, and the results are shown in Table 1 below.

2) The surface appearance was evaluated by a panel of 10 evaluators to determine whether visually recognizing the difference in luster between the bone and the floor of the embossing (19) for artificial leather specimens. When the number of persons who answered that there is gloss difference is less than 5, it is defined that there is no gloss difference and it is defined as ○ (excellent appearance).

Specifically, the method for measuring the difference in gloss between the bone and the floor of the embossing 19 in the artificial leather specimen is that the light (light source), the artificial leather specimen and the eyes of the evaluator are placed at right angles, Keep your eyes on the same line.

Thereafter, the artificial leather specimen is repeatedly tilted at 30-60 degrees with respect to incident light of light, and visibility of the gloss difference is measured based on the valley of the embossment 19 (refer to FIG. 5).

When measuring the gloss difference, the distance between the eyes of the artificial leather specimen and the eyes of the evaluator was 30 cm or less.

 (○ Surface treatment layer thickness was uniformly formed, and excellent appearance was obtained.

 X Surface treatment layer thickness is not uniform, so the surface looks mottled.)

	Example 1	Comparative Example 1	Reference Example 1	Reference Example 2	Reference Example 3	Reference Example 4
Micro hardness	54	66	54	54	63	Not measurable
Peel strength [kgf / 30mm]	3	3	2	2.1	3	3
Softness	3.8	3.3	3.8	3.8	3.2	Not measurable
Sensibility (touch feeling)	Ⓞ	△	Ⓞ	Ⓞ	△	Not measurable
Lecture (mm)	52	76	52	55	73	Not measurable
Skin layer breakup	X	X	X	X	X	Ⓞ
Surface treatment layer thickness of embossed grains and floor (㎛)	15/15	15/10	15/15	15/15	15/15	Not measurable
Surface appearance	○	X	○	○	○	Not measurable

As can be seen from Table 1, the artificial leather of Example 1 according to the present invention has a lower microhardness, higher ductility, and a soft touch feeling than artificial leather of Comparative Example 1 in which embossing is formed by roller pressing, It can be confirmed that the surface sensitivity is excellent. In addition, the artificial leather of Example 1 according to the present invention has low flexibility as compared with artificial leather of Comparative Example 1, so that it can be confirmed that flexibility is high.

Particularly, in the artificial leather of Comparative Example 1, since the surface treatment layer is formed after the emboss is formed, the thickness of the embossed bone and the surface treatment agent applied to the floor are not uniform, and the difference in gloss between the embossed bone and the surface treated layer formed on the floor The appearance of the surface of the artificial leather is uneven.

Meanwhile, the artificial leather of Example 1 according to the present invention was prepared in the same manner as in Example 1, except that the backside layer was coated with the coating solution so that the backside layer was not coated, and that the composition for the preparation of the prefoaming layer contained no copolymer of vinyl chloride and vinyl acetate It can be confirmed that the peel strength is superior to that of the artificial leather of Reference Example 2.

Further, the artificial leather of Example 1 according to the present invention has a lower microhardness and higher ductility than synthetic leather of Reference Example 3 in which the degree of polymerization of the polyvinyl chloride resin contained in the foam layer is higher than that of the present invention, It can be confirmed that the sensibility is excellent.

Further, it can be confirmed that the artificial leather of Reference Example 4 in which the degree of polymerization of the polyvinyl chloride resin in the skin layer is lower than the degree of polymerization of the polyvinyl chloride resin in the foamed layer is undesirable because the skin layer is blown upon foaming.

(2) The kinetic friction coefficient, the squeak index, the antifouling property, the amount of generated volatile organic compounds (VOCs), the surface cross-link density, the surface tension, the viscosity, and the odor of the artificial leather prepared in Examples 1-3 and Reference Example 5-12 And whitening phenomenon were measured. The results are shown in Table 3 below.

- Coefficient of friction

The artificial leather specimens were placed on top of each other with a universal material tester, and the average force (Fa) required for pulling at a speed of 300 mm / min was measured by pressing a weight of 4.5 kg (W).

- Squeak Index

Using a universal testing machine, the artificial leather specimens are placed on top of each other and pressed with a force of 4.5 Kg. The force deviation (F) and average force (Fa) required to pull at a speed of 100 mm / min are measured , And the Squeak index was calculated by ΔF / Fa.

- Antifouling

Artificial leather was attached to a universal wear tester (Toyoseiki), a piece of Cotton Soil Test Cloth was placed on the artificial leather, and a constant load of 0.9 kg was applied.

At this time, a pressure of 0.14 kgf / cm 2 was applied to the rubber diaphragm to contaminate the automobile seat for 500 cycles, and the automotive seat was contaminated again for 500 cycles after the contaminated cloth was replaced.

The contaminated sheet for automobiles is placed in an opening of a colorimeter and a green filter is mounted to measure the reflection value of the artificial leather in the uncontaminated part. The average value (%) of staining was calculated by measuring the reflection value (%) at the intermediate polished portion between the center and the outer edge of the stained portion.

- Amount of volatile organic compounds ( VOCs ) generated

The amount of volatile organic compounds (VOCs) generated was prepared as described above, and the test piece was placed in a desiccator, which was a 4-liter glass container, and was sealed and heated in an oven for 2 hours. Thereafter, the sample was allowed to stand in a laboratory at 25 ° C. for 1 hour, and the lid of the desiccator was opened for about 3 cm to 4 cm. Volatile organic compounds (VOCs) emitted from the test specimen were collected and the amount of the generated volatile organic compounds (VOCs) was measured by a measuring instrument.

- Surface cross - link density

The surface cross-link density measures the amount of crosslinked urethane that does not dissolve in boiling xylene or decahydronaphthalene. The artificial leather specimens are weighed to 1 mg (m1) on a chemical balance and placed on a mesh or metal plate with a perforated metal plate. Subsequently, the container is placed in boiling xylene or decahydronaphthalene, and left for 6-8 hours.

Thereafter, the container with the residue is removed from the boiling solvent, cooled to room temperature, and dried, and the residual amount (m2) is weighed to 1 mg.

Surface cross-link density (%) G is calculated as m2 / m1 x100.

- Surface tension ( Dyne test )

Referring to FIGS. 6 and 7, when a pen (a dyne pen) containing a liquid having a specific tension of 20 to 60 degrees is applied and stretched on a synthetic leather, if the tension of the liquid is larger than the surface tension of the synthetic leather, If the liquid tension is smaller than the surface tension of artificial leather, the liquid spreads flat and spreads well.

At this time, the internal angle? Of the liquid 100 is measured.

The larger the angle, the smaller the surface tension of the artificial leather.

- Viscosity

Viscosity was measured using a Brookfield viscometer.

First, the temperature of the sample is set to 25 DEG C, the sample is placed in a large-sized cylindrical container having a size of 600 ml or more, and a spindle No. 64 is placed in the center of the sample container.

Then slowly lower the viscometer down to the point of the spindle, and measure the viscosity by rotating the spindle at 30 RPM.

-smell

According to the sensory test method, the panel was composed of three or more persons and the odor was directly evaluated. The following Table 2 shows the odor according to the direct sensory evaluation. It is divided into 6 steps from 1 to 6, It shows that it is flying badly.

Odor too	Smell / expression of odor
One	No odor.
2	Almost undetectable odor.
3	The smell is weakly detected and does not disintegrate.
4	The odor is easily detected and somewhat disgusting.
5	Strong smell and disgust.
6	Stimulating and intense smell.

- whitening phenomenon

The whitening phenomenon was visually confirmed by the presence of white dots on the synthetic leather surface.

(O: occurrence of whitening phenomenon, X: no whitening phenomenon occurred)

	Example 1	Example 2	Example 3	Reference Example 5	Reference Example 6	Reference Example 7	Reference Example 8	Reference Example 9	Reference Example 10	Reference Example 11	Reference Example 12	Reference value
Coefficient of friction	0.3	0.25	0.3	0.3	0.35	0.15	0.15	0.15	0.15	0.1	0.4	0.2-0.5
Squeak Index	0.1	0.1	0.1	0.1	0.20	0.05	0.1	0.1	0.1	0.05	0.3	Less than 0.15
Antifouling (%)	5	4.5	4.9	10	7	5	5	7	7	5	8	-
Amount of VOCs generated (㎍ / m 2 )	220	220	220	800	220	220	220	220	220	220	220	-
Surface cross-link density (%)	80	85	82	90	78	80	80	70	70	75	75	-
Surface tension (°)	107.5	107.5	107.5	83.4	100	107.5	107.5	100	100	105	90	-
Viscosity [cps]	400	400	400	80	400	400	400	400	400	400	400	-
Smell	3	3	3	4	3	3	3	3	3	3	3	-
Whitening	X	X	X	X	X	X	X	○	○	○	X	-

As shown in Table 3, the artificial leather of Examples 1 to 3 according to the present invention was formed by coating the surface treatment layer with an aqueous surface treatment agent, and the artificial leather of Reference Example 5 in which the surface treatment layer was formed by the oily surface treatment agent The artificial leather of Examples 1 to 3 according to the present invention was found to be excellent in antifouling property against leather, but it was also found that the artificial leather of Examples 1 to 3 according to the present invention had a good anti- It is preferable to use the composition of Reference Example 12 which does not contain the silicone compound, Reference Example 6 which contains less than the specific content range, and the amount of the component exceeding the specific content range because the inclusion of the surface treatment layer formed using the aqueous surface treatment agent containing the compound in the specified content range The same coefficient of dynamic friction and the same Squeak index as those of Reference Example 7 including the same antifouling property or better Able to know.

In addition, since the surface treatment layer of artificial leather according to Examples 1 to 3 according to the present invention is formed by further including an infrared ray irradiation step, it can be seen that the coefficient of dynamic friction is better than that of Reference Example 8 which does not include the irradiation step have.

Reference Example 9 in which an aqueous solvent is added to a curing agent without adding a curing agent to an aqueous solvent during the preparation of the aqueous surface treatment agent and Reference Example 10 in which an aqueous solvent and a curing agent are mixed in the aqueous surface treatment agent In the case of Reference Example 11, which is not sufficiently dried after application to the skin layer, whitening occurs.

Further, in Reference Examples 9 to 11, the surface cross-link density is also lower than that of Examples 1 to 3 according to the present invention, and it can be seen that the dynamic friction coefficient is not satisfied.

3. Artificial leather Of the foam layer  Foam cell size, number, shape and measurement

When the artificial leather of Example 1 and Comparative Example 1 prepared above was cut in the vertical direction, the foam cell size (average diameter), number and shape included in the cross-section of the foam layer were measured, and the results are shown in Table 4 Respectively.

The average diameter of the foamed cells formed in a unit area of 1 mm ^{2 on} the end face of the foam layer 13b 'after cutting the artificial leather in the vertical direction was measured using a scale bar of an optical microscope Respectively.

- The number of foam cells was measured by using an optical microscope after the artificial leather was cut in the vertical direction, and the number of foam cells formed in a unit area of 1 mm ² on the cross section of the foam layer (13b ') side was measured.

	Example 1	Comparative Example 1
Foam cell size [탆]	135-200	100-400
Foam cell number [pieces / mm 2 ]	15-20	5-10
Foam cell shape	rectangle	Unevenness
Foaming layer thickness (mm)	0.5	0.3

As can be seen from Table 4, the artificial leather of Example 1 according to the present invention retains the spherical shape of the foamed cells in the foamed layer even after forming the embossed body by calendering and vacuuming, (Average diameter) of 135-200 占 퐉, and the number of foam cells on the cross-section of the foam layer is 15-20 pieces / mm ² , thereby realizing excellent cushioning feeling, high ductility and excellent sensitivity. On the other hand, in the artificial leather of Comparative Example 1, when the emboss is formed by the roller pressing method, the shape of the foam cell is irregular such as elongated and distorted, the size and number of foam cells are small, , Ductility and sensibility are all lower than those of the artificial leather of Example 1.

4. Embo  Transfer efficiency

As a result of measuring the embossing efficiency of the artificial leather of Example 1 and Comparative Example 1, it was found that the artificial leather of Comparative Example 1 had an embossing efficiency of 80-90% by using an embossing device of a roll pressing method during embossing, , Artificial leather of Example 1 according to the present invention showed an embossing efficiency close to 100% by using an embossing apparatus using a vacuum during embossing.

[Description of Symbols]

1: artificial leather 11: backside layer

13b, 13b ': foam layer 13a: pre-foamed layer

15: Skin layer 17: Surface treated layer

19: Embo 19a: Embo's goal

19b: The floor of the emboss

Claims (20)

1. Artificial leather with a micro hardness of 45-59,

   The microhardness was measured immediately after the needle contacted the artificial leather at a pressing speed of 1 mm / s in a peak hold mode using a microhardness tester (Asker Micro Durometer, model: MD-1 CAPA), that is, And the maximum value at the time of the measurement.
2. The method according to claim 1,

   Wherein the artificial leather comprises a back layer having a coating layer formed on one side thereof.
3. 3. The method of claim 2,

   Wherein the coating layer is formed of a coating solution containing 70 to 130 parts by weight of a plasticizer and 0.5 to 10 parts by weight of a curing agent, based on 100 parts by weight of the polyvinyl chloride resin.
4. The method of claim 3,

   Wherein the polyvinyl chloride resin is a mixed resin comprising 60-90 wt% of a homopolymer of vinyl chloride and 10-40 wt% of a copolymer of vinyl chloride and vinyl acetate.
5. The method of claim 3,

   Wherein the viscosity of the coating solution is 80-140 seconds at 25 ° C in the viscosity of a cup (# 3 cup).
6. 3. The method of claim 2,

   The artificial leather further includes a foam layer, a skin layer, and a surface treatment layer which are sequentially laminated on the backside layer,

   And an emboss formed on the skin layer and the surface treatment layer.
7. The method according to claim 6,

   Wherein the peel strength of the back layer and the foam layer is 2.5-6 kgf / 30 mm.
8. The method according to claim 6,

   Wherein the foam layer comprises 60-120 parts by weight of a plasticizer and 5-15 parts by weight of a blowing agent, based on 100 parts by weight of the polyvinyl chloride resin.
9. 9. The method of claim 8,

   Wherein the polyvinyl chloride resin is a polyvinyl chloride resin having a degree of polymerization of 900 to 1200. Description:
10. 9. The method of claim 8,

    Wherein the foam layer further comprises a copolymer of vinyl chloride and vinyl acetate in an amount of 5-20 parts by weight based on 100 parts by weight of the polyvinyl chloride resin.
11. The method according to claim 6,

    The foam layer has a man-made leather comprises a rectangle of foam cells having an average diameter of 10-30 120-250㎛ pieces per unit area of 1mm ² of the foam layer side end face or flat cross-section.
12. The method according to claim 6,

    Wherein the skin layer comprises 60-120 parts by weight of a plasticizer and a pigment, based on 100 parts by weight of the polyvinyl chloride resin.
13. 13. The method of claim 12,

    Wherein the polyvinyl chloride resin is a polyvinyl chloride resin having a degree of polymerization of 1250-3000.
14. The method according to claim 6,

    Wherein the artificial leather has a Squeak index of less than 0.15 and a dynamic friction coefficient of 0.2 to 0.5.
15. The method according to claim 6,

    Wherein the emboss is formed by vacuum using vacuum.
16. The method according to claim 6,

    Wherein a region where a difference in thickness between a valley of the emboss and a surface treatment layer formed on a crest is less than 5 mu m is 80% or more of the entire surface of the artificial leather.
17. The method according to claim 6,

    Wherein a region where the ratio of the thickness of the surface treatment layer formed on the embossed floor to the thickness of the surface treatment layer formed on the embossed bone is 0.7-1 is 80% or more of the entire surface of the artificial leather.
18. A backside layer preparation step (S1) of preparing a backside layer which is a woven or nonwoven fabric;

    A prefoamed or foamed layer and a skinned layer (S3) for forming a prefoamed or foamed layer and a skinned layer, respectively;

    A backside layer stacking step (S5) of stacking the backside layer on the bottom surface of the prefoamed or foamed layer;

    A skin layer laminating step (S7) of laminating the skin layer on the prefoamed or foamed layer on which the backside layer is formed;

    (S9) forming a surface treatment layer by coating the aqueous surface treatment agent on the skin layer to form a surface treatment layer;

    An infrared ray irradiation step (S11) of irradiating infrared rays onto the surface treatment layer;

    An embossing step (S13) of sucking and forming an emboss using a vacuum on the skin layer and the surface treatment layer heated through the infrared irradiation; A method for manufacturing a synthetic leather comprising the steps of:

    The artificial leather has a microhardness of 45-59,

    The microhardness was measured immediately after the needle contacted the artificial leather at a pressing speed of 1 mm / s in a peak hold mode using a microhardness tester (Asker Micro Durometer, model: MD-1 CAPA) 1s &lt; / RTI &gt; is measured.
19. 19. The method of claim 18,

    Wherein the backside layer is coated on one side with a coating solution in the backside layer preparation step (S1).
20. 19. The method of claim 18,

    The prefoamed layer 13a and the skin layer 15 are respectively formed in the step (S3) and the foamed layer 13b 'is formed by foaming the preformed foamed layer 13a after the step (S7) And forming step (S8).

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