KR20210093520A - Artificial leather manufacturing method and artificial leather manufactured therefrom - Google Patents

Abstract

The present invention relates to a method for manufacturing artificial leather and artificial leather manufactured from the same. Specifically, the present invention relates to: a method for manufacturing artificial leather, which, in artificial leather used for interior materials of automobiles (particularly, automobile seat covers), manufactures the artificial leather in one-pass, thereby having excellent production yield; and artificial leather manufactured from the same.

Description

Artificial leather manufacturing method and artificial leather manufactured therefrom

The present invention relates to a method for manufacturing artificial leather and artificial leather produced therefrom, and specifically, in artificial leather used for interior materials of automobiles (particularly, automobile seat covers), wherein the artificial leather is used in one-pass It relates to a method for manufacturing artificial leather, which is manufactured and has excellent production yield, and artificial leather manufactured therefrom.

In general, the interior of a vehicle is recognized as a second residential space, and in recent years, a functional seat cover for comfortable and pleasant driving in such an interior space of a vehicle has been in the spotlight.

The material for the automobile seat cover can be roughly divided into natural leather and artificial leather. The natural leather is expensive and the supply is not smooth, so the use of artificial leather is gradually increasing.

The artificial leather, for example, as disclosed in Korean Patent Application Laid-Open No. 10-2019-0030595 (hereinafter referred to as 'Patent Document 1'), forming a pre-foaming layer and a skin layer, respectively (S3); Laminating a back layer on the bottom surface of the pre-foaming layer (S5); laminating a skin layer on the pre-foaming layer on which the back surface layer is formed (S7); foaming the pre-foaming layer (S8); It can be prepared through a calendaring (calendaring) process comprising a.

However, in the above manufacturing method, the speed of step (S3), step (S5) and step (S7) is about 50 m/min and the speed of step (S8) is about 17 m/min, due to the significant speed difference, the entire process There was a problem in that the production yield was somewhat lowered as the speed of the artificial leather was lowered and the artificial leather could not be manufactured in one-pass.

On the other hand, as another example of the artificial leather, as disclosed in Republic of Korea Patent Publication No. 10-0873655 (hereinafter referred to as 'Patent Document 2'), the cover layer composition is applied and gelled on top of a release paper as a carrier to form a cover layer. Forming, applying the foam layer composition and foaming at 190-230 ° C. for 60-90 seconds to form a foam layer, coating an adhesive on the top thereof, and then passing through the plywood working process of the fabric, casting process can be manufactured through

However, in Patent Document 2, the cost increases by using a non-recyclable release paper, and as each layer is formed on the release paper, the transfer of heat applied during the gelling or foaming process is lowered, so that the geling speed and the speed of the foaming process are reduced. It was not as fast as about 15 m/min, so there was a problem in that the speed of the entire process was slightly lowered.

Accordingly, the present invention intends to develop and describe a one-pass artificial leather manufacturing method having excellent production yield and artificial leather manufactured therefrom.

KR 10-2019-0030595 A (published on: 2018.08.22) KR 10-0873655 B (Announcement Date: 2008.12.12)

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a one-pass artificial leather manufacturing method having excellent production yield and artificial leather manufactured therefrom.

In order to achieve the above object,

The present invention provides a surface treatment layer forming step of forming a surface treatment layer by applying and drying a surface treatment layer composition on an upper portion of a steel belt;

a skin layer forming step of forming a skin layer by applying and gelling a skin layer composition on the surface treatment layer;

a foaming layer forming step of forming a foaming layer by applying and foaming a foaming layer composition on the skin layer;

a backside layer lamination step of laminating a backside layer on the foam layer;

a steel belt cooling step of cooling the steel belt; and

An embossing step of forming an embossing on the surface treatment layer; including,

The drying, gelling and foaming provides a method for manufacturing artificial leather that uses hot air and mid-infrared (MIR) together.

In addition, the present invention is a skin layer forming step of forming a skin layer by applying and gelling a skin layer composition on a steel belt (Steel-belt);

a foaming layer forming step of forming a foaming layer by applying and foaming a foaming layer composition on the skin layer;

a backside layer lamination step of laminating a backside layer on the foam layer;

a steel belt cooling step of cooling the steel belt;

an embossing step of forming an emboss on the skin layer; and

A surface treatment layer forming step of forming a surface treatment layer by coating and drying the surface treatment layer composition on the embossing; including,

The drying, gelling and foaming provides a method for manufacturing artificial leather that uses hot air and mid-infrared (MIR) together.

Specifically, the artificial leather manufacturing method of the present invention uses a steel belt with high heat transfer rate as a carrier to reduce costs while drying, gelling and foaming by using hot air and mid-infrared (MIR) together as heat sources. An object of the present invention is to provide an artificial leather manufacturing method capable of one-pass while increasing the gelling and foaming efficiency to increase the overall line production speed and artificial leather manufactured therefrom.

The artificial leather manufacturing method of the present invention uses a steel belt with high heat transfer rate as a carrier, and uses hot air and mid-infrared (MIR) as heat sources for drying, gelling and foaming, thereby increasing drying, gelling and foaming efficiency. It has the effect of enabling one-pass while the line production speed is fast.

In addition, the artificial leather manufacturing method of the present invention has an excellent effect of cost reduction compared to using a release paper which is a carrier that cannot be recycled in the prior art by using a steel belt as a carrier.

1 is a configuration diagram schematically showing an embodiment of an artificial leather manufacturing method according to the present invention.
Figure 2 is a flow chart showing an embodiment of the artificial leather manufacturing method according to the present invention.
Figure 3 is a flowchart showing another embodiment of the artificial leather manufacturing method according to the present invention.
4 is a side cross-sectional view showing a laminated structure of artificial leather manufactured according to the artificial leather manufacturing method of the present invention.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Here, in adding reference numerals to the components of each drawing, it should be noted that only the same components are marked with the same reference numerals as much as possible even though they are displayed on different drawings.

An embodiment of the present invention includes a surface treatment layer 17 forming step (S1) of coating and drying a surface treatment layer composition on an upper portion of a steel belt to form a surface treatment layer;

a skin layer 15 forming step (S3) of forming a skin layer by applying and gelling a skin layer composition on the surface treatment layer;

a foaming layer 13 forming step (S5) of forming a foaming layer by applying and foaming a foaming layer composition on the skin layer;

a back layer 11 laminating step (S7) of laminating a back layer on the foam layer;

a steel belt cooling step of cooling the steel belt (S9); and

An embossing (19) forming step (S11) of forming an embossing on the surface treatment layer; including,

The drying, gelling and foaming relates to a method for manufacturing artificial leather (1) using hot air and mid-infrared (MIR) together (see FIGS. 1 and 2).

Hereinafter, each step will be described in detail.

Surface treatment layer forming step (S1)

The surface treatment layer forming step (S1) is a step of forming a surface treatment layer 17 by applying and drying a surface treatment agent on an upper part of a steel belt, and may be coated in a single layer or in multiple layers of two or more layers. .

In the present invention, it may be coated with one degree as a specific embodiment, and in this case, the artificial leather production yield is more excellent.

Specifically, the surface treatment agent is the main agent (A); curing agent (B); aqueous solvent (C); and a silicone compound (D); It may be a two-part aqueous surface treatment agent comprising a.

Subject (A)

The subject (A) 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 among the polyurethanes, for example, a method using a compound having a carboxylic acid group as a raw material at the time of the urethanation reaction is exemplified. Examples of the compound having a carboxylic acid group used as the raw material of the polyurethane include 2,2'-dimethylol propionic acid, 2,2'-dimethylol butanoic acid, 2,2'-dimethylol butyric acid, and 2,2'-dimethyl All pentanoic acid etc. are mentioned.

Examples of the method for producing a polyurethane having a hydroxyl group among the polyurethanes include a method of reacting an excess amount of polyol and/or glycol with a polyisocyanate to obtain a polyurethane having a hydroxyl group at the terminal. As the compound having a hydroxyl group used as a raw material of the polyurethane, for example, polyester polyol, polyether polyol, polycarbonate polyol, polyacetal polyol, polyacrylate polyol, polyester amide polyol, polythioether polyol, polybutadiene polyolefin polyols, such as these, etc. are mentioned.

In addition, as a method for producing a polyurethane having an amine group in the polyurethane, for example, an amino alcohol such as 2-aminoethanol, 2-aminoethyl ethanolamine, and diethanolamine, aminophenol, or the like is reacted with a urethane prepolymer having an isocyanate group terminal. and a method of obtaining a polyurethane having an amine group.

The polyurethane may preferably be a polycarbonate-based polyurethane using 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) may be 20-40% by weight, preferably 25-35% by weight. If the polyurethane content in the main body (A) is less than 20% by weight, the touch feeling and scratch resistance, light resistance, heat resistance, abrasion resistance and solvent resistance are lowered, and when it exceeds 45% by weight, whitening and appearance irregularities occur. may be included.

The whitening phenomenon means a white defect in the shape of a white dot appearing in the middle of the artificial leather surface after the water-based surface treatment agent is applied.

hardener (B)

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

Specifically, the compound having an aziridine group refers to a compound including a hetero three-membered ring composed of 2 carbon atoms and 1 nitrogen atom, and 3-(3-methoxyphenyl)-3-(trifluoromethyl)-dia ziridine (3-(3-methoxyphenyl)-3-trifluoromethyl)-diaziridine); 3-(trifluoromethyl)-3-phenyldiaziridine (3-(trifluoromethyl)-3-phenyldiaziridine); propane-2,2-diyldibenzene-4,1-diyldiaziridine-1-carboxylate; propane-2,2-diyldibenzene-4,1-diyl diaziridine-1-carboxylate; 1,1'-(butylphosphoryl)diaziridine (1,1'-(butylphosphoryl)diaziridine); oxydiethane-2,1-diyldiaziridine-1-carboxylate; 3,3-bis(1,1-difluorohexyl)-[1,2]diaziridine (3,3-bis(1,1-difluoro-hexyl)-[1,2]diaziridine); 1-aziridine propanoic acid (1-Aziridinepropanoicacid); 2-methyl-2-[[3-(2-methyl-1-aziridinyl)-1-oxopropoxy]methyl]-1,3-propaneylester (2-methyl-2-[[3- (2-methyl-1-aziridinyl)-1-oxopropoxy]methyl]-1,3-propanediylester); 2-ethyl-2-[[3-(2-methyl-1-aziridinyl)-1-oxopropoxy]methyl]-1,3-propaneylester (2-ethyl-2-[[3- (2-methyl-1-aziridinyl)-1-oxopropoxy]methyl]-1,3-propanediylester); 2-ethyl-2-[[3-(2-methyl-1-aziridinyl)-1-oxopropoxy]methyl]-1,3-propanediylbis(2-methyl-1-aziridinepropano ate) (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-aziridinopropionate) (pentaerythritol tris( 3-aziridinopropionate)) and combinations thereof.

The compound having an isocyanate group is, for example, toluene diisocyanate, diphenylmethane diisocyanate, modified diphenylmethane diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate, lysine isocyanate, cyclohexane diisocyanate, 3 -Isocyanetomethyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate, methylenediphenyl isocyanate, xylene diisocyanate, tetramethylxylene diisocyanate, norbornene diisocyanate, triphenylmethane triisocyanate, poly It may include at least one selected from the group consisting of phenyl polymethylene polyisocyanate, polyisocyanate containing carbodiimide group, polyisocyanate containing allophanate group, polyisocyanate containing isocyanurate group, and combinations thereof. .

The compound having a carbodiimide group may be polycarbodiimide.

The curing agent (B) may be included in an amount of 5-20 parts by weight, preferably 8-15 parts by weight, based on 100 parts by weight of the main agent (A). When it is contained in less than 5 parts by weight, it is uncured and the physical properties such as light resistance, heat resistance, scratch resistance, abrasion resistance, solvent resistance and hydrolysis resistance are reduced, and when mixed in excess of 20 parts by weight, the raw material value increases, so it is undesirable. It can be mixed within the above range.

aqueous solvent (C)

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

In addition, the alcohol may be at least one selected from the group consisting of alcohols such as methanol, ethanol, propanol, butanol, and the stability of the reaction and the aqueous surface when mixing each component constituting the aqueous surface treatment agent due to the inclusion of the alcohol It has the characteristic that stability of a processing agent is ensured.

Due to the aqueous solvent (C), the main agent (A) and the curing agent not participating in the three-dimensional crosslinking reaction can form an interpenetrating polymer network intertwined with each other, and volatile organic compounds due to the use of the organic solvent It is possible to reduce the generation of odor substances according to substances (VOCs).

The aqueous solvent (C) may be included in an amount of 10-25 parts by weight, preferably 15-20 parts by weight, based on 100 parts by weight of the main agent (A), but is not limited thereto.

Silicone compound (D)

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

The content of polysiloxane in the silicone compound in liquid form may be 5-30% by weight, preferably 10-20% by weight.

The silicone compound (D) may be included in an amount of 1-15 parts by weight, preferably 3-10 parts by weight, based on 100 parts by weight of the main agent (A). When included in an amount of less than 1 part by weight, the antifouling property of artificial leather is reduced, and when included in an amount exceeding 15 parts by weight, the surface texture becomes excessively slippery and the squeak index can be minimized. Therefore, it can be used within the above content range.

In the present invention, the squeak index is a numerical value of noise generated in friction between the artificial leather and the human body, that is, the occupant. By satisfying the above range, the artificial leather of the present invention has a squeak index of less than 0.15, preferably less than 0.14, Low noise and soft to the touch. When the squeak index exceeds 0.15, the noise (noise) is severe and the stick slip characteristic, which is a friction phenomenon accompanying vibration, is strong, and thus may be within the above range.

The squeak index is calculated using a universal testing machine (Universal Testing Machine) to stack artificial leather specimens on top of each other and press with a weight of 4.5Kg, and the deviation (ΔF) and average force (Fa) of the force required to pull it at a speed of 100mm/min. ) can be measured and calculated as ΔF/Fa.

In addition, the dynamic friction coefficient (μ) is to hold the slip property when the object moves while in sliding contact with another object, and the artificial leather of the present invention may have a dynamic friction coefficient of 0.2-0.5, preferably 0.25-0.5. there is. When the coefficient of dynamic friction is less than 0.2, it may not be able to hold slip property, so that the sitting feeling is not good, and if it exceeds 0.5, the squeak index increases due to friction between the artificial leather and the occupant, so it may be within the above range.

The coefficient of dynamic friction can be calculated as Fa / W by measuring the average force (Fa) required to stack the artificial leather specimen up and down using a universal material testing machine and press it with a weight of 4.5 kg (W) and pull it at a speed of 300 mm/min. .

The surface treatment agent described above may further include one or more additives selected from the group consisting of a gloss enhancer, an antifoaming agent, a leveling agent and a matting agent, and the type and content thereof are not limited as long as the object of the present invention is not impaired.

The viscosity of the two-component aqueous surface treatment agent may be 200-400cps, preferably 210-320cps at 20-25°C, preferably at 25°C. If it is less than 200 cps, the artificial leather does not feel soft and relatively stiff, and the surface treatment agent flows down to lower the coating efficiency. If it exceeds 400 cps, irregularities such as the surface treatment layer is not uniform, and whitening occurs when drying. This may occur, so that it may have a viscosity within the above range.

The surface treatment layer 17 of the present invention may be formed by applying and drying the surface treatment agent described above on the upper part of the steel belt. The application method may be a known coating method, for example gravure coating, bar coating, slot-die coating, comma coating or knife coating, in a specific embodiment, slot-die coating to coat a predetermined amount with the same thickness method can be used.

The drying may be performed at 155-180° C., preferably 160-175° C. for 3-10 seconds, preferably 4-8 seconds, and within the above range, the drying efficiency is excellent, so that the production rate is fast and one-pass This has the effect of being able to manufacture artificial leather.

In addition, during the drying, the line length may be 2-5 m, preferably 3-4 m, and within the above range, a conventional calendering or casting process that performs a drying step using hot air using steam as an existing heat source. 60-90%, preferably 70-85%, compared to the length of the drying line of the surface treatment agent in the production yield is excellent.

Specifically, in the present invention, it is characterized in that hot air and Medium Infrared Ray (MIR) are used together to increase drying efficiency. In the present invention, the hot air may be one using gas or steam, and in a specific embodiment, steam may be used. In this case, the cost is low compared to gas, and the drying efficiency is excellent.

In addition, the mid-infrared radiation is an electromagnetic wave having a wavelength range of about 2.0-6.0 μm, and it is easy to control up to a high temperature of about 600-800 ° C. It has a shortening effect. In addition, the mid-infrared rays have an excellent drying efficiency because the reaction rate of the sol is faster than that of near-infrared ray (NIR).

In the existing calendering or casting process, steam has been used alone as a heat source for drying the surface treatment agent. In this case, the drying time is 30-50 seconds and 80-100 seconds, respectively, due to heat transfer through convection, which is a very long time. There was a problem in that the production yield of artificial leather was lowered because the length of the line was also increased.

Accordingly, the present invention uses hot air and mid-infrared rays together, but in particular, by using a steel belt with excellent heat transfer as a carrier, the drying temperature is increased and the drying time is reduced so that the production speed is fast and artificial leather can be manufactured in one pass. .

The speed of the surface treatment layer forming step (S1) is 30-35 m/min, preferably 32-35 m/min, within the above range, the production yield of artificial leather is excellent and in balance with the process to be described later, one pass There is an effect that the manufacture of artificial leather is possible.

The surface treatment layer 17 formed by coating and drying as described above may have a thickness of 4-30 µm, preferably 10-20 µm, and the surface properties such as antifouling and scratch resistance of artificial leather within the above range It is excellent and has the effect of giving flexibility to artificial leather.

Skin layer 15 forming step (S3)

The skin layer forming step (S3) may be a step of forming the skin layer 15 by applying and gelling the skin layer composition on the surface treatment layer.

The skin layer composition may be in a sol state including 50-90 parts by weight of a plasticizer and a pigment based on 100 parts by weight of the polyvinyl chloride resin.

The polyvinyl chloride resin in the skin layer composition may be a paste polyvinyl chloride resin prepared by emulsion polymerization, and specifically, the polymerization degree may be 1400-2000, preferably 1450-1900, and within the above range, artificial It has an excellent effect on the durability of leather.

The degree of polymerization may be measured under 30°C conditions according to ASTM D1243.

In addition, the polyvinyl chloride resin may have a weight average molecular weight of 1600-1900 g/mole, preferably 1650-1800 g/mole, and within this range, the durability of artificial leather is excellent.

The weight average molecular weight can be measured by a known method.

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

The phthalate-based plasticizer is a plasticizer having very good compatibility with the polyvinyl chloride resin. For example, one selected from the group consisting of dibutyl phthalate, diethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate and butyl benzyl phthalate. More than one species may be used, but diisodecyl phthalate, which is a low volatility plasticizer, may be preferably used.

The terephthalate-based plasticizer is an eco-friendly plasticizer, for example, dioctyl terephthalate may be used, but is not limited thereto.

The trimellitate-based plasticizer is an environmentally friendly and excellent thermal stability plasticizer, for example, triisobutyl trimellitate, trinomaloctyl trimellitate, tri(2-ethylhexyl) trimellitate and triisononyl trimellitate. One or more selected from the group consisting of may be used, but is not limited thereto.

The epoxy-based plasticizer is an epoxidized double bond of an unsaturated fatty acid glycerol ester with hydrogen peroxide or peracetic acid. For example, epoxidized soybean oil, epoxidized palm oil, or epoxidized linseed oil may be used, but is not limited thereto.

The plasticizer may be included in an amount of 50-90 parts by weight, preferably 60-80 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin, and it is easy to make a sol within the above range, and the durability and ductility of artificial leather This has an excellent effect.

The pigment may be, for example, carbon black, but is not limited thereto, and its content is not limited as long as it does not impair the purpose of the present invention.

In addition, the skin layer composition may further include one or more selected from the group consisting of a heat stabilizer, a flame retardant and a filler to control melt strength and physical properties, and the type and content thereof are not limited.

The skin layer 15 of the present invention may be formed by applying and gelling the skin layer composition described above on the surface treatment layer 17 .

The coating method may be a known coating method, for example, gravure coating, bar coating, slot-die coating, comma coating or knife coating, in a specific embodiment, easy to control the thickness and easy to replace the raw material comma coating method can be used.

The gelling may be performed at 155-180° C., preferably 160-175° C. for 14-22 seconds, preferably 16-20 seconds. This has the effect of being able to manufacture artificial leather.

In addition, during the gelling, the line length may be 5-12m, preferably 8-11m, and within the above range, the skin layer in the existing casting process to perform gelling using hot air using steam as an existing heat source. Compared to the length of the gelling line, 40-80%, preferably 45-55%, is reduced, so that the production yield is excellent.

Specifically, in the present invention, hot air and mid-infrared rays can be used together as heat sources during the gelling, and since the hot air and mid-infrared rays are the same as hot air and mid-infrared rays, which are heat sources when drying the surface treatment agent, the overlapping description is omitted.

The skin layer 15 formed by coating and gelling as described above may have a thickness of 0.1-0.3mm, preferably 0.15-0.2mm, and the surface smoothness of the artificial leather is excellent within the above range, and the cushioning feeling of the artificial leather is excellent. It has a non-disruptive effect.

The speed of the skin layer forming step (S3) is 30-35 m/min, preferably 32-35 m/min, within the above range, the artificial leather production yield is excellent and in balance with the previous process, the artificial leather in one pass There is an effect that can be manufactured.

Foam layer 13 forming step (S5)

The foaming layer forming step (S5) may be a step of forming the foaming layer 13 by applying and foaming the foaming layer composition on the skin layer.

The foaming layer composition may be in a sol state comprising 50-80 parts by weight of a plasticizer and 1-10 parts by weight of a foaming agent based on 100 parts by weight of the polyvinyl chloride resin.

The polyvinyl chloride resin in the foam layer composition may be a paste polyvinyl chloride resin prepared by emulsion polymerization, and specifically, the polymerization degree may be 1500-2000, preferably 1600-1900. The degree of polymerization can be measured according to JIS K 6720-2.

In addition, the polyvinyl chloride resin may have a weight average molecular weight of 1600-1900 g/mole, preferably 1650-1800 g/mole.

The weight average molecular weight can be measured by a known method.

When the degree of polymerization and weight average molecular weight of the polyvinyl chloride resin is less than the above range, durability is reduced, and when it exceeds the above range, the hardness of the foam layer increases and cushioning feeling is reduced. Therefore, a polychloride having a degree of polymerization and weight average molecular weight within the above range. A vinyl resin may be used.

Since the plasticizer is the same as the plasticizer in the skin layer composition described above, the overlapping description will be omitted.

The plasticizer may be included in an amount of 50-80 parts by weight, preferably 55-75 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin, and when it is less than 50 parts by weight, workability and ductility are reduced and microhardness is increased, 80 If it exceeds parts by weight, the plasticizer may bleed, so it may be included within the above content range for achieving excellent ductility.

On the other hand, in the present invention, microhardness is a local hardness for a micro-specimen such as 0.5-1.5mm thick, and the indentation rate is 1mm/ in peak hold mode using a microhardness meter (Asker Micro Durometer, model name: MD-1 CAPA). s denotes the hardness of the artificial leather, measured immediately after the needle contacts the artificial leather, that is, when the load holding time of the needle is 1 s.

Specifically, there are several methods for measuring hardness, and an example is Shore hardness (Hardness Shore, 'HS'), Rockwell hardness (Hardness Rock, 'HR'), Vickers hardness (Hardness Vickers, 'HV'), noob Hardness Knoop ('HK') and micro-hardness. In the above various hardness measurement methods, shore hardness is commonly used when measuring the 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 micro specimen having a thickness of less than 5 mm.

Microhardness is the hardness of a specimen less than 5 mm, for example, a micro-specimen having a thickness of 0.5-1.5 mm as described above. As an example of a micro-hardness meter for measuring micro-hardness, there may be MD-1 CAPA of Asker Micro Durometer. there is.

The foaming agent is not particularly limited as long as it can form fine bubbles that give the necessary elasticity and thickness to the foaming layer 13, for example, azodicarbonamide (ADCA, Azodicarbonamide), p,p'-oxybisbenzene alcohol It may be a chemical blowing agent such as phonyl hydrazide (p,p'-Oxybis (benzenesulfonyl hydrazide)), p-toluenesulfonyl hydrazide (p-toluenesulfonyl hydrazide), or sodium bicarbonate (Sodiumbicarbonate).

The foaming agent may be used in an amount of 1-10 parts by weight, preferably 2-5 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin. When it is less than the above range, the ductility and cushioning feeling of the artificial leather is lowered, and when it exceeds the above range, the foamed cells in the foaming layer are excessively generated, so that the surface properties and durability are reduced, so it can be used within the above range.

The foam layer composition may further include one or more selected from the group consisting of a heat stabilizer, a flame retardant and a filler to control melt strength and physical properties.

Since the heat stabilizer, flame retardant and filler are the same as the heat stabilizer, flame retardant and filler included in the skin layer composition described above, overlapping descriptions will be omitted.

The foam layer 13 of the present invention may be formed by coating and foaming the foam layer composition described above on the skin layer 15 .

The coating method may be a known coating method, for example gravure coating, bar coating, slot-die coating, comma coating or knife coating, in a specific embodiment, a comma coating method or a slot-die coating method is used. can

The foaming can be performed at 190-220°C, preferably 210-220°C for 10-25 seconds, preferably 15-20 seconds, and within the above range, foaming efficiency is excellent, so the production rate is fast and one-pass This has the effect of being able to manufacture artificial leather.

In addition, the foaming line length may be 5-15m, preferably 8-12m, and within the above range, the calendering method for performing the foaming step using hot air using liquefied natural gas (LNG) as an existing heat source. Compared to that, the length of the foaming line is reduced by about 40-70% or 45-65%, which has an excellent effect on the production yield.

In addition, compared to the casting method of performing the foaming step using hot air using steam as a conventional heat source, the foaming line length is reduced by about 40-60% or 45-55%, thereby improving the production yield.

The foam layer 13 formed by coating and foaming as described above may have a foaming ratio of 150-500%, preferably 200-300%, and within the above range, artificial leather has a sense of volume, cushioning, and soft surface feel. There is an effect that can be given. When it is less than 150%, the microhardness of the artificial leather increases and becomes hard, and when it exceeds 500%, that is, when it is excessively foamed, the durability and strength of the artificial leather are weakened and the physical properties are deteriorated, so it is preferable to have a foaming ratio within the above range.

The foamed cells formed in the foamed layer 13 may be spherical foamed cells. The spherical foam cell is an expression in contrast to the shape of the foam cell that is crushed by external pressure or has a sharp shape, and does not necessarily mean a geometrically perfect spherical shape, and is usually referred to as a spherical shape for each foam cell. It should be understood as a concept that encompasses all levels that can be encompassed when Therefore, in the present specification, the spherical foam cell is not deformed by a physical external force, and it will be understood to maintain the spherical shape during formation.

In addition, the foamed cells may be included in 10-30 ^{cells, preferably 15-20 cells per unit area of 1 mm 2} in the side cross-section or flat cross-section of the foam layer 13 . When the number is less than 10, the ductility and cushioning feeling are reduced, and when it exceeds 30, the surface durability is lowered and physical properties such as the surface feel and cushioning feeling are reduced, so the number of foam cells within the above range can be included.

After cutting the artificial leather in the vertical or horizontal direction, the number of the foamed cells may be measured using an optical microscope to measure the number of foamed cells formed in a unit area ^{of 1 mm 2} of the side cross-section or flat cross-section of the foaming layer.

In addition, the average diameter of the foamed cells is 120-250㎛, preferably 135-200㎛, if the average diameter is less than 120㎛, or exceeds 250㎛, it is excluded from the foamed cells. The average diameter refers to an average value of the diameters that one foam cell can have. More specifically, when the foam cell is geometrically spherical, it means an average of diameters, and in the case of a shape other than the geometric spherical shape, the major axis and the minor axis. When divided by , it means the average length of the major axis.

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

The average diameter of the foamed cells is measured using a scale bar of an optical microscope after cutting the artificial leather in the vertical or horizontal direction, and then measuring ^{the average diameter of the foamed cells formed in a unit area of 1 mm 2 of the side cross-section or flat cross-section of the foam layer.} did.

In addition, the foam layer 13 may have a specific gravity of 0.7-0.9 g/cm ³ , preferably 0.7-0.8 g/cm ³ . If it is less than 0.7 g/cm ^{3 durability is reduced, and if it exceeds 0.9 g/cm 3} , ductility and cushioning feeling are reduced, so the specific gravity may be within the above range.

That is, in the foam layer 13, the structure of the spherical foam cells is not deformed by external pressure, and the foam cells contain 10 to 30 cells per unit area of 1 mm2 of the side cross-section or flat cross-section of the foam layer 13. Thus, the specific gravity ^{can have all of the characteristics of 0.7-0.9 g/cm 3} , so that the artificial leather can realize a significantly improved cushioning feeling and a soft surface feel.

In addition, the foam layer 13 may have a thickness of 0.4-0.8 mm, preferably 0.4-0.7 mm, and has an effect of providing an excellent cushioning feeling to the artificial leather within the above range.

The speed of the foaming layer forming step (S5) is 30-35 m/min, preferably 32-35 m/min, within the above range, the artificial leather production yield is excellent and in balance with the previous process, the artificial leather in one pass There is an effect that can be manufactured.

Back layer 11 lamination step (S7)

The step of laminating the back layer (S7) may be a step of adhering the back layer 11 to the upper portion of the foam layer.

The back layer 11 assists in mechanical properties, maintains the shape of artificial leather and prevents wrinkles, and includes cotton, rayon, silk, polyolefin (eg, polyethylene, polypropylene, etc.), nylon, polyester, It may be a flexible polymer such as woven fabric, non-woven fabric, knitted fabric, plain weave, spunbond, etc. of various synthetic materials based on polyurethane, and may optionally further include natural fibers and/or synthetic fibers.

Preferably, the back layer 11 can easily secure mechanical properties such as strength and flame retardant properties, and in relation to the foam layer, cotton or rayon and polyester can be advantageous in terms of sewing performance and clean appearance. A woven or nonwoven fabric containing 30-40: 60-70 weight ratio may be used.

When the polyester content exceeds the above range, combustibility, covering properties and workability are not good, and when the polyester content is less than the above range, mechanical properties are lowered, so it may be included within the above range.

The back layer 11 may have a thickness of 0.4-0.8 mm, preferably 0.5-0.7 mm, and the mechanical strength of artificial leather is excellent within the above range.

Meanwhile, the present invention optionally provides an adhesive layer forming step of forming an adhesive layer (not shown) on the foam layer after the foam layer forming step (S5) in order to increase the peel strength of the foam layer 13 and the back surface layer 11 . (S6) may be further included.

The adhesive used in the adhesive layer forming step (S6) may be an acrylic adhesive, a polyurethane adhesive, a polyvinyl chloride plastisol, a urethane adhesive, or an aqueous adhesive, but is not limited thereto.

In the present invention, in a specific embodiment Polyvinyl chloride plastisol can be used.

The polyvinyl chloride plastisol may be formed by stirring 70-130 parts by weight of a plasticizer and 0.5-10 parts by weight of a curing agent at room temperature with respect to 100 parts by weight of the 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 included in an amount of 60-90% by weight, preferably 65-85% by weight in the mixed resin. When the amount is less than 60% by weight, the peel strength between the back layer and the foaming layer is lowered, and when it exceeds 90% by weight, it is undesirable, such as smell, so it may be included within the above range.

The copolymer of vinyl chloride and vinyl acetate is a resin that imparts excellent adhesion to a woven or non-woven back layer, and the content of vinyl acetate in the copolymer is 1-15% by weight, preferably 3-10% by weight. And within the above range, there is an excellent effect of peeling strength between the back layer and the foam layer.

In addition, the copolymer of vinyl chloride and vinyl acetate may be included in the mixed resin in an amount of 10-40% by weight, preferably 15-35% by weight. If it is less than 10% by weight, the peel strength of the back layer and the foaming layer is lowered, and if it exceeds 40% by weight, mechanical properties such as heat resistance are reduced, so it may be included within the above range.

The plasticizer contained in the polyvinyl chloride plastisol may be at least one selected from the group consisting of a phthalate-based plasticizer, a terephthalate-based plasticizer, a benzoate-based plasticizer, a citrate-based plasticizer, a phosphate-based plasticizer, and an adipate-based plasticizer. .

In the present invention, preferably, a terephthalate-based plasticizer that is environmentally friendly and has excellent heat resistance may be used. For example, dioctyl terephthalate may be used as the terephthalate-based plasticizer, but is not limited thereto.

The plasticizer may be included in an amount of 70-130 parts by weight, preferably 80-120 parts by weight, based on 100 parts by weight of the mixed resin, and within the above range, the plastisol processability and peel strength of the back layer and the foam layer are excellent. there is.

The curing agent included in the plastisol may use a low-temperature curing type curing agent to increase energy efficiency and productivity, and a block isocyanate curing agent in which some or all isocyanate groups are blocked with a blocking agent may be used.

The blocking agent is phenol, ε-caprolactam, methyl ethyl ketone oxime, 1,2-pyrazole, diethyl malonate (diethyl) malonate), diisopropylamine, triazole, imidazole, and at least one selected from the group consisting of 3,5-dimethylpyrazole may be used. .

The block 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. This increases and the curing reaction proceeds.

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

The curing agent may be included in an amount of 0.5-10 parts by weight, preferably 1-5 parts by weight, based on 100 parts by weight of the mixed resin. When the amount is less than 0.5 parts by weight, the peel strength between the back layer and the foam layer is lowered due to a decrease in the degree of crosslinking, and when it exceeds 10 parts by weight, the unreacted curing agent remains as an impurity and the usability decreases, so it can be used within the above range.

The plastisol may optionally further include one or more other additives selected from the group consisting of stabilizers, fillers, pigments, viscosity reducing agents and dispersants, if necessary, and the content thereof does not affect the physical properties of the plastisol. There is no limit unless

The viscosity of the plastisol may be ?猪? (Zahn cup, #3 cup) viscosity of 20-25 ℃, preferably 80-140 seconds at 25 ℃, preferably 100-120 seconds, within the above range There is an excellent effect of coating efficiency in

The adhesive layer may be formed by coating and drying the above-described adhesive on the foam layer 13 .

The coating method may be a known coating method, for example gravure coating, bar coating, slot-die coating, comma coating or knife coating, and a comma coating method may be used as a specific embodiment.

The drying may be performed at 155-180° C., preferably 160-175° C. for 3-10 seconds, preferably 4-8 seconds, and within the above range, the drying efficiency is excellent, so that the production rate is fast and one-pass This has the effect of being able to manufacture artificial leather.

In addition, the drying line length may be 2-5 m, preferably 3-4 m, and within the above range, the adhesive in the existing casting process that performs the drying step using hot air using steam as an existing heat source. Compared to the length of the drying line, 45-65%, preferably 50-60%, is reduced, so that the production yield is excellent.

In the drying, hot air and mid-infrared rays can be used together in the same manner as drying in the surface treatment layer forming step (S1), and within the above range, the drying efficiency is excellent.

The thickness of the adhesive layer formed by coating and drying as described above may be 5-15 μm, preferably 8-12 μm, and within the above range, the peel strength of the back layer and the foam layer is excellent, and the micro-hardness of artificial leather is reduced. It has a non-disruptive effect.

Here, the back layer 11 in the back layer laminating step (S7) in 1-5kgf / cm ^2, preferably 2-4.5kgf / cm ² After the abutting position with the adhesive layer to be described later is the thickness of the adhesive layer When the pressure is applied, the adhesive is partially impregnated into the back layer 11 , and it means a thickness including the adhesive impregnated into the back layer.

When the adhesive layer forming step (S6) is further included, the peel strength of the back layer 11 and the foam layer 13 may be 2.5-6 kgf/30 mm, preferably 2.5-5.5 kgf/30 mm. If it is less than 2.5kgf/30mm, the peel strength of the back layer and the foam layer is slightly lowered, and the quality of the artificial leather is deteriorated. If it exceeds 6kgf/30mm, the microhardness increases and the touch feeling is reduced. can keep

The speed of the adhesive layer forming step (S6) and the back layer lamination step (S7) is 30-35 m/min, preferably 32-35 m/min. It has the effect of being able to manufacture artificial leather in one pass due to the balance.

Steel belt cooling step (S9)

The steel belt cooling step (S9) is a step of cooling the steel belt to 50°C or less, preferably 30-40°C, and includes a surface treatment layer 17 sequentially stacked on the steel belt within the above range; skin layer 15; foam layer 13; and a back layer 11; There is an effect that can be easily peeled off the semi-finished product containing the.

In addition, the cooling may be performed using water, and in this case, the cooling may be performed at a high speed, so that the semi-finished product can be peeled off from the steel belt.

The speed of the steel belt cooling step (S9) is 30-35 m/min, preferably 32-35 m/min, within the above range, the artificial leather production yield is excellent and the artificial leather is in balance with the previous process in one pass. There is an effect that can be manufactured.

Embossing step (S11)

The embossing step (S11) is a step of forming the embossing 19 on the peeled surface treatment layer 17, a vacuum or press-type embossing roll may be used.

In the present invention, as a specific embodiment, vacuum embossing can be used under a vacuum pressure of 0.02-0.08Mpa, preferably 0.04-0.07Mpa, and in this case, the foamed cells in the foaming layer are excellent in maintaining the cushioning feeling of the artificial leather. It has an excellent effect.

The speed of the embossing step (S11) is 30-35 m/min, preferably 32-35 m/min, within the above range, the production yield of artificial leather is excellent and the balance with the preceding process is in balance with the artificial leather in one pass. There is an effect that can be manufactured.

In addition, the artificial leather manufacturing method of the present invention may optionally further perform an infrared irradiation step (S10) of irradiating infrared rays before the embossing forming step (S11), and in this case, the embossing moldability is more excellent.

In addition, another embodiment of the present invention is a skin layer forming step (S1') of forming a skin layer by applying and gelling the skin layer composition on the steel belt (Steel-belt);

A foaming layer forming step (S3') of forming a foaming layer by applying and foaming a foaming layer composition on the skin layer;

a back layer lamination step of laminating a back layer on the foam layer (S5');

a steel belt cooling step of cooling the steel belt (S7');

An embossing step of forming an emboss on the skin layer (S9'); and

A surface treatment layer forming step of forming a surface treatment layer by coating and drying the surface treatment layer composition on the embossing (S11'); including,

The drying, gelling and foaming relates to an artificial leather manufacturing method using hot air and mid-infrared (MIR) together (see FIG. 3).

In the above manufacturing method, as compared with the manufacturing method of the embodiment, the surface treatment layer 17 forming step (S11 ') is performed last. In this case, the surface treatment layer receives less heat, so that the touch feeling is excellent. , has an excellent effect of color expression.

Specifically, the surface treatment layer forming step (S11') may be performed by applying and drying the surface treatment agent on the upper part of the embossing, and the application may be performed by a gravure coating method in an embodiment.

The drying may be performed at 155-180 ° C., preferably 160-175 ° C. for 10-25 seconds, preferably 15-23 seconds. This has the effect of being able to manufacture artificial leather.

In addition, the drying line length may be 5-15 m, preferably 7-12 m, and within the above range, the drying efficiency is excellent, so that the production speed is fast and the artificial leather can be manufactured in one pass.

On the other hand, when manufacturing artificial leather by the manufacturing method of another embodiment, the adhesive layer forming step (not shown) may be performed after the foaming layer forming step (S3').

Other than that, since each step is the same as the manufacturing method of the embodiment described above, overlapping descriptions will be omitted.

The artificial leather manufacturing method of the present invention realizes cost reduction by using a steel belt with high heat transfer rate as a carrier, while drying, gelling and drying, gelling and By increasing the foaming efficiency, the speed of each step is about 30-35 m/min, preferably 32-35 m/min, and there is an effect that a one-pass is possible while the overall line production speed is fast.

On the other hand, the artificial leather (1) of the present invention manufactured by the manufacturing method of the embodiment is a back layer 11 from the bottom to the top; foam layer 13; skin layer 15; It may include a surface treatment layer 17 and embossing 19 (see FIG. 4).

In addition, the artificial leather (1) of the present invention may have a microhardness of 45-59, preferably 50-57. When it is less than 45, the touch feeling is general and not soft, and when it exceeds 59, mechanical properties such as abrasion are lowered, so it can have a microhardness within the above range that can have a soft and excellent cushioning feeling.

The micro-hardness is measured immediately after the needle is in contact with the artificial leather at a press-in speed of 1 mm/s in the peak hold mode using a micro-durometer (asker Micro Durometer, model name: MD-1 CAPA), that is, the load holding time of the needle is 1 s. The maximum value can be measured when

In addition, the artificial leather (1) of the present invention may have a softness of 3.5-4.5, preferably 3.7-4.0, and within the above range, an excellent cushioning feeling of the artificial leather has an excellent effect.

The ductility was measured at a temperature of 23±2° C. and a relative humidity of 50±5%, using a ductility measuring device (SDL Atlas, ST300D) to prepare 5 artificial leather specimens having a pi (π) of 100 mm, and then to the ST300D device. Press to read and measure the scale moved for 15 seconds.

Hereinafter, preferred examples are presented to help the understanding of the present invention, but the following examples are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention, It goes without saying that changes and modifications fall within the scope of the appended claims.

[Example]

1. Artificial leather manufacturing

<Example 1>

(1) Forming a surface treatment layer (S1)

Isocyanate (XR-78-017, stahl) 10 with respect to 100 parts by weight of a polycarbonate-based polyurethane resin (WF-13-549, stahl) containing 30% by weight of polyurethane on a steel belt Contains parts by weight, 10 parts by weight of water, 5 parts by weight of isopropyl alcohol, 5 parts by weight of a silicone compound (HM-13-118, Stahl Corporation), 10 parts by weight of a gloss enhancer, 0.2 parts by weight of an antifoaming agent, and 0.2 parts by weight of a leveling agent. A two-part aqueous surface treatment agent having a viscosity (25° C.) of 300 cps was applied by a gravure method, and then dried at 165° C. for 6 seconds to form a surface treatment layer having a thickness of 15 μm.

At this time, the heat sources for the drying were hot air using steam and mid-infrared rays.

(2) skin layer forming step (S3)

A sol containing 75 parts by weight of a phthalate-based plasticizer (diisodecyl phthalate), 15 parts by weight of a pigment, and 2 parts by weight of a heat stabilizer based on 100 parts by weight of a paste polyvinyl chloride resin (LG Chem, LP170) on the upper surface of the surface treatment layer ) state was applied with a comma coater, and then gelled at 165° C. for 19 seconds to form a skin layer having a thickness of 0.15 mm.

At this time, the heat sources of the gelling were hot air using steam and mid-infrared rays.

(3) foam layer forming step (S5)

A foam layer composition comprising 65 parts by weight of a phthalate-based plasticizer, 2 parts by weight of a foaming agent, and 2 parts by weight of a heat stabilizer with respect to 100 parts by weight of a polyvinyl chloride resin (Hanwha Chemical, KH-10) on the upper part of the skin layer with a slot-die coater After coating, foaming was performed at 210° C. for 19 seconds to form a foam layer having a foaming ratio of 250% and a thickness of 0.5 mm.

At this time, the heat sources of the foaming were hot air using steam and mid-infrared rays.

(4) adhesive layer forming step (S6)

With respect to 100 parts by weight of a mixed resin consisting of 75% by weight of a paste vinyl chloride homopolymer and 25% by weight of a copolymer of vinyl chloride and vinyl acetate (the content of vinyl acetate is 6% by weight), 100 parts by weight of a plasticizer and 3 parts by weight of a curing agent at room temperature Manufactured by thorough stirring in ?猪? A polyvinyl chloride plastisol having a viscosity (Zahn cup, #3 cup) of 110 seconds at 25°C was applied with a comma coater on the upper portion of the foam layer, and then dried at 165°C for 6 seconds to form an adhesive layer with a thickness of 10 μm. formed.

At this time, the heat sources for the drying were hot air using steam and mid-infrared rays.

(5) back layer lamination step (S7)

A back layer having a thickness of 0.6 mm, which is a woven fabric containing cotton and polyester at a ratio of 35:65, was placed on the adhesive ^{layer and pressed at 4 kgf/cm 2} to adhere the back layer and the foam layer.

(6) Steel belt cooling step (S9)

a surface treatment layer sequentially laminated on the steel belt by water cooling the steel belt to 40°C (water temperature: 20-30°C); skin layer; foam layer; and a back layer; The semi-finished product containing the was peeled off.

(7) Embossing step (S11)

The manufacture of artificial leather was completed by adsorbing and molding the embossing under a vacuum pressure of 0.06 Mpa on the upper surface of the surface treatment layer peeled off from the steel belt.

<Example 2>

(1) skin layer forming step (S1')

A sol state containing 75 parts by weight of a phthalate-based plasticizer, 15 parts by weight of a pigment, and 2 parts by weight of a heat stabilizer with respect to 100 parts by weight of a paste polyvinyl chloride resin (LG Chem, LP170) on a steel belt. After the skin layer composition was applied with a comma coater, it was gelled at 165° C. for 18 seconds to form a skin layer having a thickness of 0.15 mm.

At this time, the heat sources for the drying were hot air using steam and mid-infrared rays.

(2) foam layer forming step (S3')

A foam layer composition comprising 65 parts by weight of a phthalate-based plasticizer, 2 parts by weight of a foaming agent, and 2 parts by weight of a heat stabilizer with respect to 100 parts by weight of a polyvinyl chloride resin (Hanwha Chemical, KH-10) on the upper part of the skin layer with a slot-die coater After coating, foaming was performed at 210° C. for 19 seconds to form a foam layer having a foaming ratio of 250% and a thickness of 0.5 mm.

At this time, the heat sources of the foaming were hot air using steam and mid-infrared rays.

(3) Adhesive layer forming step (S4')

With respect to 100 parts by weight of a mixed resin consisting of 75% by weight of a paste vinyl chloride homopolymer and 25% by weight of a copolymer of vinyl chloride and vinyl acetate (the content of vinyl acetate is 6% by weight), 100 parts by weight of a plasticizer and 3 parts by weight of a curing agent at room temperature Manufactured by thorough stirring in ?猪? A polyvinyl chloride plastisol having a viscosity (Zahn cup, #3 cup) of 110 seconds at 25°C was applied with a comma coater on the upper portion of the foam layer, and then dried at 165°C for 6 seconds to form an adhesive layer with a thickness of 10 μm. formed.

At this time, the heat sources for the drying were hot air using steam and mid-infrared rays.

(4) back layer lamination step (S5')

A back layer having a thickness of 0.6 mm, which is a woven fabric containing cotton and polyester at a ratio of 35:65, was placed on the adhesive ^{layer and pressed at 4 kgf/cm 2} to adhere the back layer and the foam layer.

(5) Steel belt cooling step (S7')

a skin layer sequentially laminated on the steel belt by water cooling the steel belt to 40°C (water temperature: 20-30°C); foam layer; and a back layer; The semi-finished product containing the was peeled off.

(6) Embossing step (S9')

Embossing was adsorbed and molded on the surface of the skin layer peeled from the steel belt under a vacuum pressure of 0.06 Mpa.

(7) surface treatment layer forming step (S11')

10 parts by weight of isocyanate (XR-78-017, stahl), 10 parts by weight of isocyanate based on 100 parts by weight of a polycarbonate-based polyurethane resin (WF-13-549, stahl) containing 30% by weight of polyurethane on the embossed upper part Viscosity including parts by weight, isopropyl alcohol 5 parts by weight, silicone compound (HM-13-118, Stahl) 5 parts by weight, gloss enhancer 10 parts by weight, antifoaming agent 0.2 parts by weight and leveling agent 0.2 parts by weight (25°C) After gravure coating with a two-component water-based surface treatment agent having a value of 300 cps, drying at 165° C. for 20 seconds to form a surface treatment layer having a thickness of 15 μm to complete the manufacture of artificial leather.

At this time, the heat sources for the drying were hot air using steam and mid-infrared rays.

<Comparative Example 1>

(1) Calendaring step

For 100 parts by weight of straight polyvinyl chloride resin (LS100, LG Chem), 85 parts by weight of a plasticizer, 6 parts by weight of a foaming agent, and 2 parts by weight of a heat stabilizer are kneaded with a foaming layer composition, and then kneaded raw materials in a kneaded state at 160-170°C. A pre-foaming layer having a thickness of 0.2 mm was prepared by passing the roll.

Separately, after kneading a skin layer composition containing 95 parts by weight of a plasticizer, 2 parts by weight of a pigment and 2 parts by weight of a heat stabilizer with respect to 100 parts by weight of a straight polyvinyl chloride resin (LS100, LG Chem), 160-170 kneading raw materials A skin layer having a thickness of 0.15 mm was prepared by passing it through a calender roll at °C.

(2) back layer lamination step

Then, on the bottom surface of the pre-foaming layer, a back layer having a thickness of 0.6 mm, which is a woven fabric including cotton and polyester in a ratio of 35:65, was thermally laminated under ^{4kgf/cm 2 .}

(3) skin layer lamination step

Then, the skin layer is thermally laminated at 90° C. on top of the pre-foamed layer on which the back layer is laminated to form a back layer from bottom to top; pre-foaming layer; and a semi-finished product in which a skin layer was laminated.

(4) foam molding step

Then, the semi-finished product was foamed at 220° C. for 88 seconds to form a back layer; foam layer; and a semi-finished product in which a skin layer was laminated.

The foam layer had a foaming ratio of 250% and a thickness of 0.5 mm.

At this time, the heat source of the foaming was hot air using liquefied natural gas (LNG).

(5) Surface treatment layer forming step

An oil-based surface treatment agent containing 95 wt% of urethane acrylate and 5 wt% of methylene dicyclohexyl diisocyanate as a curing agent was gravure-coated on the skin layer and dried at 140° C. to form a 15 μm-thick surface treatment layer.

At this time, the heat source for the drying was hot air using steam.

(6) Embossing step

The embossing was adsorbed and molded under a vacuum pressure of 0.06Mpa on the upper surface of the surface treatment layer to complete the manufacture of artificial leather.

<Comparative Example 2>

(1) skin layer forming step

After applying a sol-state skin layer composition comprising 77 parts by weight of a plasticizer, 10 parts by weight of a pigment, and 3 parts by weight of a heat stabilizer to 100 parts by weight of the paste polyvinyl chloride resin on the release paper with a comma coater, , 180 °C for 80 s A skin layer having a thickness of 1.5 mm was formed by gelling.

At this time, the heat source of the gelling was hot air using steam.

(2) foam layer forming step

After applying a sol-state foaming layer composition comprising 67 parts by weight of a plasticizer, 2.2 parts by weight of a foaming agent, and 2.2 parts by weight of a heat stabilizer to 100 parts by weight of the paste polyvinyl chloride resin on the skin layer with a comma coater, 230 It was foamed at ℃ for 80 seconds to form a foam layer having a foaming ratio of 250% and a thickness of 0.5 mm.

At this time, the heat source of the foaming was hot air using steam.

(3) Adhesive layer forming step

An adhesive composition in a sol state containing 65 parts by weight of a plasticizer and 1.7 parts by weight of a heat stabilizer with respect to 100 parts by weight of the polyvinyl chloride resin paste was applied to the upper portion of the foam layer by a comma coater, and then dried at 160° C. for 40 seconds. to form an adhesive layer having a thickness of 10 μm.

At this time, the heat source for the drying was hot air using steam.

(4) back layer lamination step

A back layer having a thickness of 0.6 mm, which is a woven fabric containing cotton and polyester at a ratio of 35:65, was placed on the adhesive ^{layer and pressed at 4 kgf/cm 2} to adhere the back layer and the foam layer.

(5) release paper peeling step

The release paper located under the skin layer was removed.

(6) Surface treatment layer forming step

An oil-based surface treatment agent containing 95% by weight of urethane acrylate and 5% by weight of methylene dicyclohexyl diisocyanate as a curing agent was coated on the skin layer from which the release paper was peeled, and then dried in a surface treatment oven at 150° C. for 100 seconds to obtain an oil-based solvent. was evaporated to form a surface treatment layer with a thickness of 15 μm.

At this time, the heat source for the drying was hot air using steam.

(7) Embossing step

Embossing was adsorbed on the surface of the surface treatment layer under a vacuum pressure of 0.06 Mpa to complete the manufacture of artificial leather.

2. Whether one-pass artificial leather is manufactured

When manufacturing the artificial leather according to the artificial leather manufacturing method of Examples 1 and 2 and Comparative Examples 1 and 2 described above, drying of the surface treatment agent and adhesive, gelling of the skin layer composition and foaming of the foam layer composition Line length The speed and time taken were measured, and the speed of each step was measured and shown in Table 1 below.

the present invention Example 1 Example 2 traditional calendaring
Method Comparative Example 1 existing casting
Method Comparative Example 2 surface treatment agent drying
(S1) line
Length (m) 3 - skin layer formation speed
(m/min)
50 - - speed
(m/min) 32 time(s) 6 Skin layer composition gelling line
Length (m) 10 10 Spare
foam layer formation speed
(m/min) 50 Skin layer composition gelling line
Length (m) 20 speed
(m/min) 31 31 speed
(m/min) 15 time(s) 19 19 time(s) 80 Foaming layer composition line
Length (m) 10 10 back layer lamination line
Length (m) 80 Foaming layer composition line
Length (m) 20 speed
(m/min) 32 32 speed
(m/min) 50 speed
(m/min) 15 time(s) 19 19 time(s) 96 time(s) 80 adhesive drying line
Length (m) 3 3 skin layer lamination line
Length (m) 80 adhesive drying line
Length (m) 10 speed
(m/min) 32 32 speed
(m/min) 50 speed
(m/min) 15 time(s) 6 6 time(s) 96 time(s) 40 back layer lamination speed
(m/min) 32 32 foam molding line
Length (m) 25 back layer lamination speed
(m/min) 15 speed
(m/min) 17 time(s) 88 steal
belt cooling line
Length (m) 10 10 surface treatment agent drying line
Length (m) 10 release paper peeling speed
(m/min)
12 speed
(m/min) 31 31 speed
(m/min) 15 time(s) 20 20 time(s) 40 embossing speed
(m/min) 30 30 embossing speed
(m/min) 15 embossing speed
(m/min) 12 surface treatment agent drying
(S1') line
Length (m) - 10 - - surface treatment agent drying
line
Length (m) 17 speed
(m/min) 30 speed
(m/min) 10 time(s) 20 time(s) 100

As confirmed in Table 1, the artificial leather manufacturing method according to the present invention uses a steel belt, which is a material with a high heat transfer rate, as a carrier, but uses steam as a heat source for drying, gelling, and foaming, and mid-infrared rays. By using it, it was confirmed that the drying, gelling and foaming efficiency was increased and the speed of each step was maintained at about 30-35 m/min, so that the production speed of the entire line was fast and one-pass was possible.

On the other hand, in the conventional calendering method, the artificial leather manufacturing method of Comparative Example 1 has a speed of 50 m/min during the skin layer lamination step, whereas the hot air using a gas as a heat source is used alone during the foam molding step, and the speed is 17 m/min. It was confirmed that one-pass artificial leather production was impossible due to the significant speed difference in the process.

In addition, in the artificial leather manufacturing method of Comparative Example 2 using a release paper as a conventional carrier, the release paper has a low heat transfer rate, so drying, gelling and foaming efficiency is not good, and furthermore, a hot air using steam as a heat source is used alone, and the speed is 15 m/min. As a result, it was confirmed that the production efficiency of artificial leather decreased.

1: artificial leather
11: back layer 13: foam layer
15: skin layer 17: surface treatment layer
19: Embo

Claims (16)

A surface treatment layer forming step (S1) of forming a surface treatment layer by coating and drying the surface treatment layer composition on the steel belt (Steel-belt);
a skin layer forming step (S3) of forming a skin layer by applying and gelling a skin layer composition on the surface treatment layer;
A foaming layer forming step (S5) of forming a foaming layer by applying and foaming a foaming layer composition on the skin layer;
a back layer lamination step of laminating a back layer on the foam layer (S7);
a steel belt cooling step of cooling the steel belt (S9); and
An embossing step (S11) of forming an embossing on the surface treatment layer; including,
The drying, gelling and foaming is an artificial leather manufacturing method using hot air and mid-infrared (MIR) together. According to claim 1,
In the surface treatment layer forming step (S1),
The surface treatment layer composition comprises a main agent (A); curing agent (B); aqueous solvent (C); and a silicone compound (D); A method for producing artificial leather that is a two-component aqueous surface treatment agent comprising a. According to claim 1,
In the surface treatment layer forming step (S1), the application is a slot-artificial leather manufacturing method that is applied in a die coating method. According to claim 1,
In the surface treatment layer forming step (S1), drying is performed at 155-180 ℃ for 3-10 seconds artificial leather manufacturing method. 5. The method of claim 4,
The artificial leather manufacturing method of the drying line length is 2-5m. According to claim 1,
In the skin layer forming step (S3),
The skin layer composition has a polymerization degree of 1400-2000 and a weight average molecular weight of 1600-1900 g/mole, based on 100 parts by weight of a polyvinyl chloride resin, in a sol state comprising 50-90 parts by weight of a plasticizer and a pigment A method for manufacturing artificial leather. According to claim 1,
In the skin layer forming step (S3), the gelling is an artificial leather manufacturing method that is performed at 155-180 ℃ for 14-22 seconds. 8. The method of claim 7,
The artificial leather manufacturing method that the geling line length is 5-12m. According to claim 1,
In the foaming layer forming step (S5),
The foam layer composition has a polymerization degree of 1500-2000 and a sol containing 50-80 parts by weight of a plasticizer and 1-10 parts by weight of a foaming agent with respect to 100 parts by weight of a polyvinyl chloride resin having a weight average molecular weight of 1600-1900 g/mole. ) state of artificial leather manufacturing method. According to claim 1,
In the foaming layer forming step (S5), the foaming is an artificial leather manufacturing method that is performed at 190-220 ℃ for 10-25 seconds. 11. The method of claim 10,
The manufacturing method of artificial leather that the foaming line length is 5-15m. According to claim 1,
The artificial leather manufacturing method further comprises an adhesive layer forming step (S6) of coating and drying an adhesive on the foam layer to form an adhesive layer. 13. The method of claim 12,
The drying is an artificial leather manufacturing method using hot air and mid-infrared (MIR) together. According to claim 1,
The speed of the steps (S1), (S3), (S5), (S7), (S9), (S11) is 30-35 m/min. A skin layer forming step of forming a skin layer by applying and gelling a skin layer composition on an upper part of a steel belt;
a foaming layer forming step of forming a foaming layer by applying and foaming a foaming layer composition on the skin layer;
a backside layer lamination step of laminating a backside layer on the foam layer;
a steel belt cooling step of cooling the steel belt;
an embossing step of forming an emboss on the skin layer; and
A surface treatment layer forming step of forming a surface treatment layer by coating and drying the surface treatment layer composition on the embossing; including,
The drying, gelling and foaming is an artificial leather manufacturing method using hot air and mid-infrared (MIR) together. An artificial leather for automobile interiors manufactured using the artificial leather manufacturing method of any one of claims 1 to 15.

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