KR20190030596A - artificial leather and a method for producing the same - Google Patents

Abstract

The present invention relates to artificial leather and a method for manufacturing the same. Specifically, the present invention relates to artificial leather having a remarkably small amount of volatile organic compounds (VOCs) generated while satisfying both Squeak index and dynamic friction coefficient required as artificial leather used in an automotive seat cover, and a method for manufacturing the same. The Squeak index is less than 0.15, the dynamic friction coefficient is 0.2-0.5, and the VOC generation amount is 500 μg/m^2 or less.

Description

Artificial leather and a method for producing same

The present invention relates to an artificial leather and a method of manufacturing the same. More particularly, the present invention relates to an artificial leather which is a synthetic leather used for an automobile seat cover, a synthetic leather which satisfies both the Squeak index and the coefficient of dynamic friction required, Leather and a process for producing 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.

As such materials for automobile seats, artificial leather, which is relatively inexpensive and satisfies the sensibility and functional aspects of natural leather, has been continuously developed.

Specifically, conventional artificial leather comprises a laminated structure including a back layer, a foam layer, a skin layer, and a surface treatment layer from the bottom.

The surface treatment layer is formed by coating a surface treatment agent on the skin layer. When the surface treatment layer is formed using a conventional oily surface treatment agent, volatile organic compounds (VOCs) An aqueous surface treating agent as disclosed in Korean Patent Laid-Open Publication No. 10-2001-0062664 has been studied so as to reduce such an unpleasant odor.

However, when the above-mentioned aqueous surface treatment agent is used, there is a problem that it is difficult to simultaneously satisfy the squeak index, which is noise caused by friction between a synthetic leather as a seat cover for an automobile and a human body, and a dynamic friction coefficient,

KR 10-2001-0062664 A (Open: 2001.07.07)

Disclosure of the Invention The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an artificial leather which is significantly less in the amount of volatile organic compounds (VOCs) The purpose is to provide.

It is another object of the present invention to provide a method for manufacturing an artificial leather for producing the artificial leather.

In order to achieve the above object,

The present invention relates to an artificial leather having a Squeak index of less than 0.15, a coefficient of dynamic friction of 0.2-0.5, and an amount of volatile organic compounds generated of 500 占 퐂 /

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 measured and calculated as? F / Fa,

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) Artificial leather.

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;

An embossing step of vacuum-forming an emboss using vacuum on the skin layer and the surface treatment layer heated by the infrared ray irradiation, the Squeak index being less than 0.15, the coefficient of dynamic friction being 0.2-0.5, and the amount of volatile organic compounds In the case of an artificial leather production method of 500 占 퐂 /

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 measured and calculated as? F / Fa,

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 present invention provides a method of manufacturing an artificial leather.

The artificial leather of the present invention has an effect of significantly reducing the amount of volatile organic compounds (VOCs) generated while simultaneously satisfying the Squeak index and the dynamic friction coefficient.

1 is a side cross-sectional view showing a laminated structure of artificial leather according to an embodiment of the present invention.
2 is a flow chart showing a method of manufacturing artificial leather according to an embodiment of the present invention.
Fig. 3 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.
4 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.

The present invention relates to an artificial leather having a Squeak index of less than 0.15, a coefficient of dynamic friction of 0.2-0.5 and an amount of volatile organic compound generation of 500 占 퐂 /

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 measured and calculated as? F / Fa,

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) In artificial leather.

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 a Squeak index of less than 0.15 or 0.14, The feeling 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 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 volatile organic compound is a hydrocarbon compound that easily evaporates into the atmosphere to generate odor or ozone. The amount of the generated volatile organic compound is measured by providing a sample of artificial leather. The specimen is placed in a desiccator, And the sample was heated in an oven for 2 hours. After that, the sample was allowed to stand in a laboratory of 25 ° C for 1 hour, and the lid of the desiccator was opened for about 3 cm to 4 cm. Volatile organic compounds emitted from the sample were collected, Can be measured with a measuring instrument.

The artificial leather of the present invention may have an amount of volatile organic compounds generated of not more than 500 μg / m 2 or not more than 400 μg / m 2. The lower limit of the artificial leather may be 0 μg / m 2, .

As described above, the artificial leather of the present invention, which satisfies both the Squeak index and the coefficient of dynamic friction, but has a remarkably small amount of volatile organic compounds generated, has a surface treatment layer 17 from the top to the bottom; A skin layer 15; Foam layers 13b and 13b '; And a back layer 11, and may include an emboss 19 formed on the surface treatment layer and the skin layer (see FIG. 1).

Hereinafter, each layer will be described in detail.

The surface treatment layer (17)

The surface treatment layer (17) comprises a base (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, .

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 of the present invention comprises the steps of: (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.

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.

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 thickness of the surface treatment layer 17 may be 4-30 占 퐉 or 4-20 占 퐉. By maintaining the thickness within the thickness range, the stain resistance can be ensured while maintaining the flexibility of the artificial leather. When the thickness is less than the above range, the thickness is too thin to reduce the durability and stain resistance. If the thickness exceeds the above range, the material cost may be increased due to an increase in the requirement of the aqueous surface treatment agent.

The skin layer (15)

The skin layer 15 is used for securing surface smoothness and realizing 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.

The polyvinyl chloride resin contained in the skin layer 15 has a higher degree of polymerization than the polyvinyl chloride resin used in the foaming layers 13b and 13b 'described later in the foam molding step (S8) It is possible to prevent the skin layer from popping out during the molding step S13.

Specifically, the polyvinyl chloride resin contained in the skin layer 15 may be a straight polyvinyl chloride resin formed by suspension polymerization, and the degree of polymerization may be 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) described later. If it exceeds the above range, the surface feel and ductility of the artificial leather may deteriorate. A polyvinyl chloride resin having a degree of polymerization can be used.

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

The phthalate plasticizer is a plasticizer having excellent compatibility with the polyvinyl chloride resin. Examples of the plasticizer include dibutyl phthalate, diethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate and butyl benzyl phthalate , Preferably diisodecyl phthalate which is 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, microhardness is increased, and when the amount is in excess of the above range, bleeding of the plasticizer occurs.

The pigment may be carbon black, but is not limited thereto.

The skin layer 15 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, and the kind and content thereof are not limited.

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.

The foam layers 13b and 13b '

The foam layers 13b and 13b 'impart softness and a cushioning feeling to the artificial leather. The foaming layers 13b and 13b' may include 5-15 parts by weight of the foaming agent and 60-120 parts by weight of the plasticizer, based on 100 parts by weight of the polyvinyl chloride resin.

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, and the degree of polymerization 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 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 And may be a chemical foaming agent such as benzene sulfonyl hydrazide, p-toluenesulfonyl hydrazide, and sodium bicarbonate.

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 softness and cushion feeling of the artificial leather deteriorates, and if it exceeds the above range, the foaming cells of the foam layer 13b are excessively produced, and the physical properties and durability of the surface are lowered.

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

The foaming layers 13b and 13b 'may have a foaming ratio of 100-500% or 150-300% after foaming at 220-230 ° C. When it is less than the above range, microhardness of the artificial leather is increased and it becomes hard. When 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 in 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 foamed layer 13b or 13b 'may have a specific gravity of 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 are not deformed in structure due to the external pressure, and the foam cells include 10-30 pieces per square millimeter of the area of the foam layer, -0.9. Thus, it is possible to realize a cushioning feeling and a smooth surface feeling which are remarkably improved in the artificial leather.

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.

The backside layer (11)

The backing layer 11 serves to support the mechanical properties and to maintain the shape of the artificial leather and to prevent wrinkles. The backing layer 11 may be made of cotton, rayon, silk, polyolefin (e.g. polyethylene, Nonwoven fabric, knitting, plain weave, spunbond, 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 a cup (Zahn 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. The thickness of the coating layer refers to a thickness including the coating solution impregnated into the backside layer 11 do. 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.

Embo (19)

The embossment 19 may be formed on the skin layer 15 and the surface treatment layer 17 by vacuum using vacuum.

The artificial leather of the present invention having the above structure may have 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 artificial leather of the present invention may have an antifouling property of less than 10% or not more than 7%. The lower limit of the artificial leather of the present invention is not limited but is more than 1% or more than 2%.

Referring to FIG. 2, the present invention includes a backside layer preparation step (S1) for preparing a backside layer which is a woven fabric or a 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; Wherein the squeak index is less than 0.15, the coefficient of dynamic friction is 0.2-0.5, and the amount of volatile organic compounds generated is 500 占 퐂 / m ² or less.

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 measured and calculated as? F / Fa,

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 present invention relates to an artificial leather manufacturing method.

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 17 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 monolayer, the above-described aqueous surface treatment agent may be applied. In the case of multi-layer coating, a composition excluding the silicone compound (D) may be applied to the base in the above-described aqueous surface treatment agent, An aqueous surface treating agent as described above may be applied.

Further, the aqueous solvent may be evaporated by drying the aqueous surface treatment agent applied in the step (S9) at 110-150 占 폚 or 130-150 占 폚 for 80-120 seconds. If the drying time is less than the above temperature and time range, the water-based solvent can not evaporate and the whitening phenomenon may occur on the surface of the artificial leather due to the uncured state, or the Squeak index and the dynamic friction coefficient can not be satisfied at the same time. If dried, the heat resistance may be lowered and discoloration may occur. Therefore, drying can be performed within the above temperature and time 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 be a step of irradiating infrared rays at 150-180 DEG C for 5-15 seconds or 10-15 seconds. It is more preferable that the dynamic friction coefficient of the artificial leather can satisfy the range of 0.25 to 0.4 by irradiation with the infrared ray.

When the infrared ray is irradiated at less than the above-mentioned temperature and time, the skin layer is not softened and the embossing is not formed well in the post-embossing step. When the infrared ray is irradiated in excess of the temperature and time, Infrared rays can be irradiated.

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

The step (S13) may be performed at a vacuum of 0.02-0.08 MPa or 0.04-0.07 MPa, which is a step of performing vacuum adsorption molding of the embossment. When the step is performed at a pressure lower than the vacuum pressure range, it is difficult to form an embossing, and the cushion feeling may be deteriorated. When the pressure exceeds the above range, the surface treatment layer may be damaged or surface properties may be deteriorated. Lt; / RTI >

The process may also be carried out at a temperature of 160-180 占 폚, or 170-180 占 폚. When the process is performed at a temperature lower than the above-mentioned range, it is difficult to sufficiently form an embossment. When the process is performed in excess of the above-mentioned range, the surface properties of the artificial leather are roughly torn due to high temperature, have.

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. Preparation of aqueous surface treatment agent

≪ Example 1 >

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.

≪ 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 Respectively.

≪ 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, .

2. Manufacture of artificial leather including surface treatment layer

One side of the backing layer 11, which is a woven or nonwoven fabric, is coated with a coating solution in the form of polyvinyl chloride plastisol.

The preformed foam layer 13a and the composition for preparing the skin layer 15 were kneaded and passed through a calender roll at 160 to 170 DEG C to form a prefoamed layer 13a having a thickness of 0.3 mm and a skin layer having a thickness of 150 mu m (15) are formed by calender molding.

Thereafter, the backside layer 11 coated on one side of the bottom surface of the prefoamed foil layer 13a is thermally laminated.

Next, the skin layer 15 is heat-laminated on the pre-foamed layer 13a on which the back layer 11 is formed.

Subsequently, the laminated semi-finished product is passed through an oven at 220 ° C to foam the pre-foamed layer 13a at a predetermined ratio, thereby forming a backside layer 11; A foam layer 13b '; And the skin layer 15 was laminated on the surface of the substrate.

Thereafter, the aqueous surface treatment agents of Examples 1 to 3 prepared in 1 above were gravure coated on the skin layer 15 and dried at 140 ° C for 90 seconds to evaporate the aqueous solvent, thereby forming a 15 μm thick surface treatment layer ( 17 are formed.

Subsequently, the upper surface of the surface treatment layer 17 is irradiated with infrared rays at 160 DEG C for 14 seconds.

Subsequently, the emboss 19 is vacuum-formed on the surface of the skin layer 15 and the surface treatment layer 17 of the semi-finished product heated by the infrared ray irradiation under the conditions of 0.04 MPa and 170 캜 to form an emboss Leather.

≪ Comparative Example 1 &

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 1 &

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 2 &

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 3:

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 4 &

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 5:

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 6:

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 7:

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

[Experimental Example]

1. Physical properties of artificial leather

(1) The kinetic friction coefficient, the squeak index, the antifouling property, the amount of generated volatile organic compounds (VOCs), the surface cross-link density, and the surface roughness of the artificial leather of Examples 1-3, Comparative Examples 1 and 1- Tension, viscosity, odor and whitening were measured and the results are shown in Table 2 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. 3 and 4, 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 1 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 Comparative Example 1 Reference Example 1 Reference Example 2 Reference Example 3 Reference Example 4 Reference Example 5 Reference Example 6 Reference Example 7 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 can be seen in Table 2, the artificial leather of Examples 1 to 3 according to the present invention had a surface treatment layer formed by coating with an aqueous surface treatment agent, and the artificial leather of Comparative Example 1 in which the surface treatment layer was formed with an oily surface treatment agent The antifouling property of the leather is excellent, but the amount of VOCs generated is greatly reduced, and the odor is not disintegrated, and the coating on the high viscous in vaskin layer can be confirmed to be good.

In addition, since the artificial leather according to Examples 1 to 3 according to the present invention includes a surface treatment layer formed using an aqueous surface treatment agent containing a silicone compound in a specific content range, the artificial leather according to Reference Example 7, It can be seen that the dynamic friction coefficient and the Squeak index are all satisfied and the antifouling property is equal or superior to that of Reference Example 1 which is contained in the content range below the content range and Reference Example 2 which contains the content in the range exceeding the specific content range.

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 3 which does not include the irradiation step have.

Reference Example 4 in which an aqueous solvent was added to the curing agent without adding a curing agent to an aqueous solvent during the preparation of the aqueous surface treatment agent, and Reference Example 4 in which an aqueous solvent and a curing agent were mixed in the aqueous surface treatment agent In the case of Reference Example 6, which is not sufficiently dried after application to the skin layer, whitening occurs.

Further, in Reference Examples 4 to 6, 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.

1: artificial leather 11: backside layer
13a: pre-foamed layer 13b, 13b ': foamed layer
15: Skin layer 17: Surface treated layer
19: Embo
100: Solution θ: Cabinet

Claims (25)

The Squeak index is less than 0.15, the coefficient of dynamic friction is 0.2-0.5, and the amount of volatile organic compounds generated is less than 500 占 퐂 /
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 measured and calculated as? F / Fa,
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) Artificial leather. The method according to claim 1,
Wherein the artificial leather has a Squeak Index of 0.14 or less, a dynamic friction coefficient of 0.25-0.5, and an amount of volatile organic compounds generated of 400 占 퐂 / m2 or less. The method according to claim 1,
The artificial leather comprises a surface treatment layer (17) from top to bottom; A skin layer 15; Foam layers 13b and 13b '; And an embossing (19) formed on the surface treatment layer and the skin layer. The method of claim 3,
Wherein the surface treatment layer comprises a subject (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). 5. The method of claim 4,
(A) is 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, wherein the polyurethane is dispersed in an aqueous solvent (A-1). 6. The method of claim 5,
Wherein the polyurethane is a polycarbonate-based polyurethane. The method according to claim 6,
Wherein the polyurethane content in said subject (A-1) is 5-30% by weight. 5. The method of claim 4,
The above-mentioned subject (A) is an artificial leather in which an acryl-modified polyurethane further containing acrylate in a main chain is dispersed in an aqueous solvent (A-2). 9. The method of claim 8,
Wherein the acrylic-modified urethane content in the subject (A-2) is 1-10% by weight. 9. The method of claim 8,
The subject matter (A-2) comprises 0.01 to 2% by weight of siloxane in the subject (A-2). 5. The method of claim 4,
The subject (A) is characterized in that the 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 the subject A-1 and the main chain (A-2) dispersed in an aqueous solvent at a weight ratio of 1: 9-4: 6 is used as the acrylic-modified polyurethane. 5. The method of claim 4,
Wherein the curing agent (B) is contained in an amount of 1-25 parts by weight based on 100 parts by weight of the subject (A). 5. The method of claim 4,
Wherein said aqueous solvent (C) is water or an alcohol or a mixture of water and an alcohol. 5. The method of claim 4,
The silicone compound (D) may be either a liquid phase in which the polysiloxane is dispersed in water or a polysiloxane in bead form,
Wherein the content of the silicone compound in the liquid silicone compound (D) is 5-30 wt%. 5. The method of claim 4,
Wherein the silicone compound (D) is contained in an amount of 1-15 parts by weight based on 100 parts by weight of the subject (A). 5. The method of claim 4,
Wherein the aqueous surface treatment agent further comprises 0.1-0.5 parts by weight of a defoaming agent and 1-5 parts by weight of a leveling agent with respect to 100 parts by weight of the subject (A). 5. The method of claim 4,
Wherein the viscosity of the aqueous surface treatment agent is 150-700 cps at 25 占 폚. 5. The method of claim 4,
The aqueous surface treatment agent comprises (a) adding a curing agent (B) to an aqueous solvent (C) followed by stirring;
(b) adding the stirred mixture in step (a) to the subject (A) followed by stirring; Wherein the synthetic leather is made from a process for the production of an aqueous surface treatment agent. 19. The method of claim 18,
Wherein the step (a) is a step of stirring for 40 minutes to 5 hours. 19. The method of claim 18,
Wherein step (b) is a step of stirring for 0.2-1 hours. The method of claim 3,
Wherein the surface treatment layer has a surface cross-link density of 70-98% and a surface tension of 90-130 [deg.]. The method according to claim 1,
The artificial leather has an antifouling property of less than 10%. 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;
(S13) for forming an emboss by suction using vacuum on the skin layer and the surface treatment layer heated by the infrared ray irradiation, and a Squeak index of less than 0.15, a dynamic friction coefficient of 0.2-0.5, and a volatile Wherein the amount of the organic compound generated is not more than 500 占 퐂 / m ² ,
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 measured and calculated as? F / Fa,
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) In synthetic leather. 24. The method of claim 23,
Wherein the step (S11) is a step of irradiating infrared rays at 150-180 DEG C for 5-15 seconds. 24. The method of claim 23,
Wherein the emboss is formed using a vacuum at a vacuum of 0.02-0.08Mpa and a temperature of 160-180 < 0 > C in step (S13).

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