KR101969324B1 - Manufacturing Method of Artificial Upper Leather - Google Patents

Abstract

The present invention relates to a production method of an eco-friendly upper-type artificial leather implementing a grain layer and a papillary layer of natural leather, which comprises: a first impregnation process of sequentially impregnating a non-woven fabric with an aqueous urethane resin and a latex resin; a second impregnation process of impregnating the impregnated non-woven fabric with a mixture of the aqueous urethane resin and the latex resin; an embossing process in which the non-woven fabric coated with the aqueous urethane resin is pressed by an emboss roller; a surface treatment process of impregnating the embossed non-woven fabric with a resin composition including the aqueous urethane resin, a curing agent, and a quencher; and a first back surface treatment process of impregnating a back surface of the surface-treated non-woven fabric with a non-solvent resin solution.

Description

{Manufacturing Method of Artificial Upper Leather} [0002] The present invention relates to a method of manufacturing a leather-

More particularly, the present invention relates to a process for producing an environmentally friendly upper leather artificial leather which is excellent in surface durability and printability and does not use an organic solvent. And a manufacturing method thereof.

Recently, various artificial leather has been developed and widely used as a substitute for natural leather. Depending on the tanning method and finishing method, the leather may be divided into various types of products such as hats, rafts, garters, uppers, patterns, epithets, suede, velours, buckskin and nubuck. Among these leather upper, the cowhair is tanned with chromium salt and dyed and painted with casene-based paint, and it is mainly used as a material for shoes, handbags and the like.

As shown in Fig. 1, the natural leather is composed of a silver layer, a dermal layer, a papilla layer, a reticular layer, and a subcutaneous layer laminated below the silver layer, which is the epidermis. Since the silver layer forms the outer leather and the silver layer and the papilla form the lining leather, the quality of the artificial leather is determined depending on how the silver layer and the papilla layer are implemented.

For example, Korean Patent Laid-Open Publication No. 10-2017-0100803 discloses a method of printing on the surface of an upper synthetic leather using a sublimation transfer method Thereby solving the problem that the dye is separated or the color is discolored. The upper artificial leather of the prior art can improve the printing performance by improving the printing method, but it can not solve the fundamental problem that the color is discolored if it is used for a long time because of its surface durability as compared with the natural upper. Based artificial leather is advantageous in that its price is inexpensive, but its quality is inferior.

Therefore, it is preferable that the upper leather-like artificial leather is made of a micro-fabric non-woven fabric having a stable structure and high density compared to a fabric or a knitted fabric because it can realize the advantages / characteristics of the natural leather.

On the other hand, in Korean Patent Registration No. 10-0039958, a resin bonded nonwoven fabric structure composed of ultrafine fibers is thermocompression-bonded, laminated layers of a polymeric elastomer and a surface coating layer are successively applied, and thermocompression is performed, An upper leather artificial leather excellent in focusing effect and smoothness is manufactured. Such a manufacturing method can produce an upper leather artificial leather excellent in surface durability, but there is a problem because contaminants (toxic chemicals) may be discharged in the process or remain in the product by using an organic solvent such as dimethylformamide .

Korean Patent Registration No. 10-0099212 discloses a process for producing an upper synthetic leather by wet-processing a polyurethane elastomer on a nonwoven fabric, wherein a high-shear composite fiber and a general composite fiber are used, and before the polyurethane elastomer is impregnated, The upper surface of the nonwoven fabric is brushed and then coated with PVC or polyurethane. However, in the case of the upper fabricated by this method, Artificial leather has a problem that it is difficult to ensure sufficient surface durability.

Korean Patent Publication No. 10-2017-0100803 Korean Patent Publication No. 10-0039958 Korean Patent Publication No. 10-0099212 Korean Utility Model Publication No. 20-1995-0018975 Korean Registered Patent No. 10-1861086

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems of the prior art, and it is an object of the present invention to provide an artificial leather which is environmentally friendly without using an organic solvent, It is an object of the present invention to provide a method for producing leather.

It is also an object of the present invention to provide a method for producing an upper leather artificial leather excellent in surface durability, moisture permeability, air permeability and printability.

It is also an object of the present invention to produce an upper synthetic leather having improved flame retardancy by adding a flame retardant in the manufacturing process.

In order to accomplish the above object, the present invention provides a method for manufacturing an upper synthetic leather sheet, comprising the steps of: impregnating a nonwoven fabric with a water-based urethane resin and a latex resin in sequence; impregnating the impregnated nonwoven fabric with an aqueous urethane resin and a latex resin A second impregnation step of impregnating the nonwoven fabric with the aqueous urethane resin, the second impregnation step impregnating the mixture with the aqueous urethane resin, the embossing step of pressing the nonwoven fabric coated with the aqueous urethane resin with the emboss roller, And a first back surface treatment step of impregnating the back surface of the surface-treated nonwoven fabric raw material with the non-solvent resin solution.

The method may further include a second back surface treatment step of adding a flame retardant agent to the back surface of the non-woven fabric back surface treated by the first back surface treatment step.

Further, the method may further include a tumbling process for tumbling the nonwoven fabric fabric that has undergone the surface treatment process.

The aqueous urethane resin is preferably a resin composition comprising an aqueous urethane resin and alkylaminosilane.

According to the present invention, an upper artificial leather is manufactured by using an environmentally friendly method which does not use an organic solvent, but the quality of the leather is improved by implementing the silver layer and the papilla layer of natural leather.

Further, it is possible to provide an upper leather-like artificial leather excellent in surface durability, moisture permeability, air permeability and printability, and exhibits an effect of improving flame retardancy by adding a flame retardant in the production process.

1 is a sectional view of natural leather.
FIG. 2 is a process diagram showing a manufacturing process of the upper artificial leather according to the present invention.
3 is a photograph of an upper leather artificial leather (a) and a natural leather (b) according to the present invention.

Hereinafter, the present invention will be described in more detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The method of manufacturing the upper leather artificial leather according to the present invention includes the silver surface layer and the nipple layer of natural leather, and adopts an environmentally friendly manufacturing method, and is manufactured in the same order as shown in FIG.

Referring to FIG. 1, a process 100 for preparing a nonwoven fabric, a first impregnation process 200 for impregnating the resin sequentially, a process for printing out the impregnated nonwoven fabric 300 after the elution 300 and the sanding 400 500), a second impregnation process (600) for impregnating the printed nonwoven fabric with a mixture of aqueous urethane resin and latex resin, a step (700) of sanding and impregnating the impregnated nonwoven fabric with the surface of the nonwoven fabric, A step (900) of embossing the surface of the nonwoven fabric by sanding the nonwoven fabric and impregnating the surface-treated nonwoven fabric with a resin composition comprising an aqueous urethane resin, a curing agent and a quencher, A first backside treatment process 1200 for impregnating the nonwoven fabric with the nonwoven fabric raw material, and a second backside treatment process 1200 for impregnating the nonwoven fabric raw material with the non- Adding a flame retarder to the back surface of the nonwoven fabric to proceed the process to the sequence of the second back coating process 1300 for flame retardation processing.

In the step (100) of preparing the nonwoven fabric, it is preferable to use a dense fabric. Specifically, the sea-island type nonwoven fabric is prepared (110), and the nonwoven fabric is woven to produce a nonwoven fabric (120).

As a resin for impregnating the nonwoven fabrics, an aqueous urethane resin and a latex resin are applied, a step of sequentially impregnating the nonwoven fabrics into the respective resins, and a step of impregnating the mixture of the aqueous urethane resin and the latex resin So that artificial leather having a desired thickness can be produced.

The aqueous urethane resin is excellent in properties such as elasticity, abrasion resistance, heat resistance, flexibility, adhesiveness, etc., and is widely used as a binder in the production of artificial leather because of excellent releasability and tensile strength. The aqueous urethane resin is used in impregnation, coating, embossing, and surface treatment, and is a raw material that directly affects the surface durability and printability of the produced artificial leather.

In addition, since the latex resin has excellent elasticity, it is possible to improve the adhesive strength, durability and texture of the artificial leather by using the aqueous latex resin together with the aqueous urethane resin, so that an increased effect can be obtained when the aqueous urethane resin and the latex resin are used together.

Recently, in Korean Patent Registration No. 10-1861086, a silica component is added to an aqueous urethane resin, thereby improving the adhesive strength and applying it to the production of artificial leather. In order to prevent the emission of VOC, aminopropyltriethoxysilane is reacted in the production of urethane resin, in order to ensure sufficient adhesion performance without using a pretreatment agent when a solvent or an adhesive of a waterless type or an aqueous type is used, Amine, acetone, etc. are used, and the manufacturing cost of the aqueous urethane resin is increased, resulting in a problem of poor price competitiveness.

Therefore, in the present invention, by applying the resin composition comprising the alkylaminosilane in the impregnation process using the aqueous urethane resin, the adhesion strength is improved and the surface durability and printability of the finally produced artificial leather are improved.

When the aqueous urethane resin and the latex resin are used in combination, a resin composition in which an aqueous urethane resin and an alkylaminosilane are mixed is first prepared, and then the latex resin Is preferably used in combination. At this time, the aqueous urethane resin and the latex resin are preferably blended in a weight ratio of 1: 1 to 1: 0.5.

The alkylamino silane may be 3-aminopropyltriethoxysilane as disclosed in Korean Patent Publication No. 10-1861086. However, since the alkylaminosilane is used in the form of a resin composition instead of reacting with an aqueous urethane resin, It has been found desirable to apply aminosilane.

Specific examples of such alkylaminosilanes include 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propyldimethoxymethylsilane, 3- It has been found that the desired effect of the present invention can be obtained when a silane having an aminoalkylamino group of any one of ethoxysilane and [3- (6-aminohexylamino) propyl] trimethoxysilane is applied.

The resin composition is preferably contained in an amount of 10 to 15 parts by weight of alkylaminosilane based on 100 parts by weight of the aqueous urethane resin. If the content of the alkylaminosilane is too small, there is no difference in adhesion between the aqueous urethane resin and the aqueous urethane resin alone, and if the content of the alkylaminosilane is too large, the silane component content is excessively large, .

The first impregnation process 200 is performed by wetting the prepared high-density nonwoven fabric by impregnating the prepared high-density nonwoven fabric into the aqueous urethane resin (210) and impregnating the latex resin continuously (220) After the impregnation is completed, it is preferable to perform mangling work and dry completely.

The nonwoven fabrics after the first impregnation process 200 are subjected to a leaching process 300 at a temperature of 80 ° C. for 40 minutes in an aqueous solution of caustic soda of 3 to 5 wt% do.

Through this process, a resin layer is formed on the surface of the nonwoven fabric. The printing process 500 can be performed on the sanded fabric. Such a printing process 500 can be applied to digital printing or printing, and it is possible to print necessary patterns, patterns, characters, designs, etc. on the surface of artificial leather through a printing process. The printing process 500 may be omitted depending on the kind of the product.

The second impregnation process 600 is performed by impregnating the nonwoven fabrics subjected to the sanding process and / or the printing process again with the resin. In the second impregnation process 600, the impregnation of the mixture of the aqueous urethane resin and the latex resin Impregnation process is performed. Through this impregnation process, a resin layer (a resin layer formed by the first impregnation process and the second impregnation process) corresponding to 30 to 40% of the total thickness of the artificial leather is formed.

Next, a step (700) of sanding and impregnating the impregnated nonwoven fabric fabric is performed. The sanding may be performed by sanding the fabric using a sandpaper machine. Through this surface treatment process, the hair formed on the surface is shortly and finely sandwiched to realize the effect of natural leather.

The sandwiched nonwoven fabric is subjected to an embossing process (800) to form a surface embossing pattern. After the impregnation of the resin mixture, the embossing process is performed at 150 ° C using an emboss roller at a pressure of 30 to 50 kg / (800). When the embossing process 800 is completed, the nonwoven fabric is dried.

The embossed nonwoven fabric is subjected to a surface treatment (step 900) by sanding again.

Thereafter, the surface treatment step (1000) is performed by impregnating the surface-treated nonwoven fabric with a resin composition comprising an aqueous urethane resin, a curing agent and a quencher. That is, the composition is prepared by stirring the aqueous urethane resin, the curing agent, and the quencher, and the composition is coated on the surface with a printing roller or a spray, followed by drying at 100 to 120 ° C for 5 to 6 minutes. At this time, the aqueous urethane resin is also preferably used as the resin composition containing alkylaminosilane. In addition, any of the above-mentioned curing agents and quenchers may be used as long as they are commonly used.

The nonwoven fabric fabricated in the surface treatment process 1000 is subjected to the back surface treatment process after the washing and tumbling process 1100.

The backside treatment process can be performed in a primary and secondary stages. In the primary backside treatment process 1200, the backside of the nonwoven fabric is impregnated with a solvent-free resin and wound. The impregnated resin is impregnated and dried After 3 days of natural curing, backside treatment can be performed. The non-solvent resin is preferably a solventless urethane resin, and it is preferably used as a resin composition containing alkylaminosilane.

In this case, a flame retardant may be added to impart artificial leather with flame retardancy. In this case, a second back surface treatment process in which the cured fabric is impregnated with a flame retardant agent on the back of the fabric twice by a printing roller and dried at 100 to 120 ° C 1300). ≪ / RTI >

Examples of the flame retardant include inorganic flame retardants such as ammonium phosphate, triethyl phosphate and phosphate ester or inorganic flame retardants such as red phosphorus, tin oxide, antimony trioxide, zirconium hydroxide, aluminum hydroxide and barium metaborate. It is preferable to use a phosphorus flame retardant.

In the present invention, the step of impregnating the resin or the resin composition can be carried out continuously by supplying the nonwoven fabric raw material to the printing roller. When the aqueous urethane resin and the latex resin are impregnated sequentially, the nonwoven fabric is first impregnated with the aqueous urethane resin (resin composition) by the first printing roller, the secondary impregnated with the latex resin by the second printing roller, Followed by drying for 2 to 5 minutes while passing through a drier of the impregnation method. In addition, the step of impregnating the mixture of the aqueous urethane resin and the latex resin comprises the steps of supplying the dried nonwoven fabric raw material to the third printing roller, impregnating the resin mixture, drying it for 2 to 5 minutes while passing it through a dryer at 100 to 120 ° C . ≪ / RTI >

That is, in the impregnation process of the present invention, the resin is applied to the nonwoven fabric through the third impregnation, and the density of the artificial leather produced by repeating the impregnation process as described above is improved. For example, when impregnating the aqueous urethane resin composition during the primary impregnation, impregnating the latex resin in the secondary impregnation with the aqueous urethane resin composition during the third impregnation, and not using the mixed resin in the second impregnation, The density of the leather was reduced by about 20 to 30%, and it was confirmed that the order of the impregnation process and the use of the mixed resin affected the properties of the artificial leather.

In order to confirm the characteristics of the upper artificial leather according to the present invention, the upper artificial leather was manufactured as follows.

12 parts by weight of 3- (2-aminoethylamino) propyltrimethoxysilane was blended with 100 parts by weight of the aqueous urethane resin to prepare an aqueous urethane resin composition.

The woven nonwoven fabric fabric (polyester nonwoven fabric) was impregnated sequentially with the aqueous urethane resin composition and the latex resin in the first printing roller to perform the first impregnation process. After the drying step, the nonwoven fabric was impregnated with the aqueous urethane resin composition and the latex resin by a second printing roller so that the weight ratio of the aqueous urethane resin and the latex resin was 1: 0.6, And dried. In addition, the sanding process was performed when each process was completed.

Next, the mixture was impregnated with the resin mixture of the aqueous urethane resin composition and the latex resin as described above while passing through the third printing roller. Thereafter, the emboss roller was used to apply pressure of 40 kg / m < 2 >

To increase the surface durability of the embossed nonwoven fabric fabric, a mixture of an aqueous urethane resin composition, a curing agent and a quenching agent was prepared and applied to the surface of the fabric by spraying. Thereafter, it was dried at 110 ° C for about 6 minutes and wound. The wound nonwoven fabric was washed and tumbled, and then impregnated urethane resin was impregnated on the back side with a printing roller, dried and cured for 3 days.

Ammonium phosphate was impregnated to the backside of the cured nonwoven fabrics twice using a printing roller, dried at 110 ° C and discharged, and the upper fabric was dumped to soften the dried fabric to complete the upper artificial leather (Example 1).

For comparison, in Example 2, an aqueous urethane resin composition was prepared by blending 10 parts by weight of 3- (2-aminoethylamino) propyldimethoxymethylsilane with respect to 100 parts by weight of an aqueous urethane resin. In Example 1, Upper artificial leather was produced through the same process.

In Comparative Example 1, a water-soluble urethane resin and a latex resin were used in the same manner as in Example 1, except that no alkylaminosilane was added. In Comparative Example 2, 100 parts by weight of an aqueous urethane resin 10 parts by weight of 3-aminopropyltriethoxysilane was blended to prepare an aqueous urethane resin composition. The same procedure as in Example 1 was followed to produce an upper synthetic leather.

The fabric weight of the upper synthetic leather was 250 g / m < 2 > and the apparent density was calculated from the measured thickness of the artificial leather and the unit weight of the nonwoven fabric after dissolution.

In order to evaluate the printability, the printing process was omitted in the manufacturing process, and instead, the artificial leather was produced, and then the release paper on which the print layer was formed was adhered to the surface of the artificial leather, and the print layer was bonded through hot lamination and the release paper was separated. In order to evaluate the stability of the formed print layer, 100 grids were formed by knurling at intervals of 1 mm each in the longitudinal and lateral directions, and the tape was attached to the surface thereof, and then the grating was pulled at right angles to measure the number of gratings remaining thereon. The results are shown in Table 1.

Apparent density (g / cm3) Adhesion Example 1 0.48 100/100 Example 2 0.47 100/100 Comparative Example 1 0.32 98/100 Comparative Example 2 0.35 94/100

The results of Table 1 indicate that the upper artificial leather according to the production method of the present invention has an apparent density higher than that of Comparative Examples 1 and 2 and superior in adhesion, showing excellent surface durability and printability.

Further, when 3-aminopropyltriethoxysilane was used as the alkylaminosilane, it was found that the surface durability and printability were rather lowered, and the selection of the alkylaminosilane in consideration of the compatibility with the aqueous urethane resin was inferior to the quality of the artificial leather .

As shown in FIG. 3, when the upper leather artificial leather and the natural leather leather produced according to the present invention are compared with each other, the silver surface layer and the nipple layer of natural leather are realized and high quality artificial leather can be obtained. It was found that artificial leather having excellent physical properties can be obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments and that various changes and modifications may be made therein without departing from the spirit and scope of the invention. Change is possible. Such variations and modifications are to be considered as falling within the scope of the invention and the appended claims.

Claims (4)

A first impregnation step of sequentially impregnating the nonwoven fabric into the aqueous urethane resin composition and the latex resin;
A second impregnation step of impregnating the impregnated nonwoven fabric so that the weight ratio of the aqueous urethane resin composition and the latex resin is 1: 0.6;
An embossing step of pressing the nonwoven fabric with an emboss roller;
A surface treatment step of impregnating the embossed nonwoven fabric with a resin composition comprising an aqueous urethane resin composition, a curing agent and a quencher;
A first backside treatment step of impregnating the backside of the surface-treated nonwoven fabric with a solventless resin solution;
A second back surface treatment step of adding a flame retardant agent to the back surface of the non-woven fabric back surface treated by the first back surface treatment step;
A tumbling step of tumbling the nonwoven fabric through the surface treatment step;
/ RTI >
Wherein said aqueous urethane resin composition comprises 12 parts by weight of 3- (2-aminoethylamino) propyltrimethoxysilane based on 100 parts by weight of an aqueous urethane resin. delete delete delete

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