KR20180111147A - Manufacturing method of artificial leather to reduce the deviation of color and fastness - Google Patents

Abstract

The present invention relates to a method for manufacturing artificial leather having less variation of color and light fastness in artificial leather by enhancing the uniformity of the artificial leather. The method comprises the steps of: shrinking sea island yarn nonwoven fabric; eluting the sea component of the sea island composite yarn; padding the nonwoven fabric with polyvinyl alcohol; impregnating the nonwoven fabric with polymeric elastomers; removing the polyvinyl alcohol; forming napping on the nonwoven fabric; and dyeing the nonwoven fabric. According to the present invention, microfiber nonwoven fabric is formed by eluting the sea component of the sea island before impregnating with the polymeric elastomers, and the shape of the nonwoven fabric is fixed by being padded with the polyvinyl alcohol, so that the polymeric elastomers are easily and uniformly impregnated into the microfiber nonwoven fabric to achieve uniform distribution, and variations in color and light fastness of each part in artificial leather are reduced finally.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing artificial leather having improved color and fastness deviation characteristics,

The present invention relates to a method for producing an artificial leather having improved uniformity of an artificial leather to thereby minimize variations in color and light fastness of the artificial leather.

The artificial leather is made by impregnating a nonwoven fabric formed by three-dimensionally entangled microfine fibers with a polymer elastomer so as to be brushed and dyed, and has a soft texture and a unique appearance similar to natural leather and is used in shoes, clothes, gloves, And automobile interior materials.

A general method for producing a suede-like artificial leather is to produce a non-woven fabric through a non-woven fabric manufacturing process such as needle punching of marine microfiber composite yarn capable of dissolving a marine component, applying a polymeric elastomer such as polyurethane, To finely fine with a fineness of 0.01-0.3 denier, buffing the surface to form bristles, and dyeing and finishing with a desired color.

In such a manufacturing method, the elastomeric polymer is impregnated in the sea-island type composite yarn in a state in which the marine component is not eluted, and the penetration of the elastomeric polymer is uneven due to the disturbance due to the presence of the sea component. As a result, the impregnation distribution of the elastomeric polymer in the non- It becomes. In addition, when the elution is carried out, the elution of the decomposed components can not be uniformed due to the interruption caused by the polymeric elastomer impregnated, resulting in a deviation of the fiber structure due to the difference in elution property.

Therefore, after the elution, the uniformity of the nonwoven fabric is lowered, for example, the uniformity of the fiber structure of the nonwoven fabric, the impregnation uniformity of the elastomeric polymer, the uniformity of the length of the corn and the distribution thereof are lowered, There is a problem that a difference in the light fastness rating of the daylight occurs.

Korean Patent Laid-Open Publication No. 2016-0082303 (Process for producing suede-like artificial leather having uniform color)

In order to solve the above-mentioned problems, it is an object of the present invention to provide a method of manufacturing an artificial leather for reducing variation in color and light fastness of each part.

In order to solve the above-described problems, the present invention provides a method of manufacturing a sea-island composite yarn, comprising the steps of: preparing a short fiber of a sea- Shrinking the nonwoven fabric; Eluting the sea component of the sea-island type composite yarn to form a microfine nonwoven fabric; Padding the microfine nonwoven fabric with polyvinyl alcohol to obtain a shape-stable nonwoven fabric; Impregnating the shape-stable nonwoven fabric with a polymeric elastomer to obtain a polymeric elastomer-impregnated nonwoven fabric; Removing the polyvinyl alcohol from the polymeric elastomer impregnated nonwoven fabric; Buffing the surface of the nonwoven fabric to form a brushed surface; And dyeing the nonwoven fabric with a desired color, wherein the color and fastness deviation characteristics are improved.

Further, the present invention provides an artificial leather produced by the above-described manufacturing method and having improved color fastness and deviation characteristic with a light fastness (ISO 105 method, 84 MJ / ㎡ irradiation) of grade 3 or more.

According to the present invention, before the impregnation of the polymeric elastomer, the sea component of the marine product is eluted to form a microfine nonwoven fabric and padded with polyvinyl alcohol to fix the shape of the nonwoven fabric, so that the polymeric elastomer is easily and uniformly impregnated into the microfine nonwoven fabric, It is possible to reduce variations in color and light fastness of each part in artificial leather finally.

The present invention relates to a nonwoven fabric comprising a nonwoven fabric made of short fibers of a sea-island type composite yarn capable of eluting a sea component, eluting a sea component of the sea-island type composite yarn, impregnating the nonwoven fabric with polyvinyl alcohol (PVA) , The polyvinyl alcohol is removed from the nonwoven fabric, the bristles are formed on the nonwoven fabric, and the nonwoven fabric is dyed to produce an artificial leather having an improved average value of light fastness and a less variation in color and light fastness .

According to the present invention, since PVA strongly holds the skeleton of the microfiber fiber while forming the final fiber structure by finely finishing the fibers uniformly before impregnating the nonwoven fabric with the elastomeric polymer in the process of producing the artificial leather, The nonwoven fabric impregnated and uniformly impregnated and dispersed easily and uniformly, and the variation in hue and light fastness due to unevenness of the polymer elastomer after dyeing can be reduced.

The short fibers of the sea-island type composite yarn are subjected to melt-co-spinning of a cast component and a sea component composed of polyethylene terephthalate (PET) as a conductive component and an alkali-soluble modified polyester as a sea component, followed by stretching, Followed by cutting to an appropriate length.

The nonwoven fabric may be produced by using a conventional needle punching manufacturing method for the short fibers of the sea-island type composite yarn.

When the shrinkage ratio of the nonwoven fabric thus produced is shrunk to 10 to 15% by hot water (hot water), steam, or dry heat, the apparent density of the nonwoven fabric is improved and the fiber structure of the nonwoven fabric is reduced in space, The uniformity of the distribution can be improved.

Thereafter, the nonwoven fabric shrunk by the shrinkage is treated with an aqueous solution of caustic soda of 8 to 12 wt% to elute the alkali soluble polyester as a seawater to obtain a microfine nonwoven fabric of 0.3 denier or less. At this time, the density of the elution bubbles is preferably 0.2 to 0.5 g / cm 3, because the padding of the PVA and the impregnation of the polymer elastomer can be facilitated while forming a dense and uniform distribution of the fibers.

Conventionally, the polymeric elastomer is impregnated into the nonwoven fabric and then the marine component is eluted. However, in this case, a new space is formed by the elution of the marine component, and as a result, the distribution of the elastomeric polymer is uneven. The polymeric elastomer impregnated later can be uniformly impregnated with the space of the nonwoven fabric.

In the case of the microfine nonwoven fabric, the fibers may be microfine due to the dissolution of marine components and the fiber structure may be weakened. In the present invention, it is possible to suppress the polyvinyl alcohol by padding the microfine nonwoven fabric to 0.1 to 30 wt%.

That is, since the polyvinyl alcohol adheres to the surface of the microfine fiber to make the fiber stiff and has the shape stability that the skeleton of the nonwoven fabric is maintained without falling, the polymer elastomer can easily and uniformly penetrate into the space of the nonwoven fabric have.

In addition to the stabilization of the shape of the nonwoven fabric, the treatment with polyvinyl alcohol also provides an effect of preventing the occurrence of non-uniform dyeing of the fibers due to excessive adhesion of the elastomeric polymer to the fibers.

If the padding amount of the polyvinyl alcohol exceeds 30% by weight, impregnation of the elastomeric polymer is inhibited, increase in the amount of impregnation is inhibited, and uniformity of the fiber structure is lowered in the nonwoven fabric, so that impregnation of the elastomeric polymer can be made non- .

The polyvinyl alcohol to be used is preferably an aqueous solution of 3 to 20% by weight of polyvinyl alcohol having a degree of saponification of 80 to 90%.

Thereafter, polymeric elastomer impregnation is performed. As the polymeric elastomer, polyurethane is generally used. Impregnation is carried out in order to give the artificial leather the same tactile feel as in natural leather, due to the peculiar flexibility elasticity and denseness of the polyurethane elastic body.

If the content of the elastomer is less than 15% by weight, the paper feeling becomes strong. When the content of the elastomer is more than 35% by weight, It is not desirable.

Then, the polyvinyl alcohol can be removed by subjecting the nonwoven fabric impregnated with the polyvinyl alcohol and impregnated with the polymeric elastomer to hot water washing with water at 50 to 99 ° C.

At this time, it is preferable that the hydrolysis liquid contains 1 to 3 wt% of a surfactant and 0.1 to 0.5 g / L of acetic acid because the polyvinyl alcohol can be more easily removed.

If the polyvinyl alcohol can not be removed, the final texture of the artificial leather may be deteriorated.

Thereafter, buffing is performed on the surface of the nonwoven fabric to form brushed, and the desired color can be dyed using a conventional method.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. It is to be understood, however, that the following examples and comparative examples are given for the purpose of illustration only and are not to be construed as limiting the scope of the present invention. It is to be understood that within the scope of the present invention, It will be apparent to those skilled in the art that the present invention can be carried out without departing from the spirit and scope of the invention.

[Example 1]

A nonwoven fabric in which sea water (51 mm in fiber length) in which alkali-soluble polyester was used as a sea component and polyethylene terephthalate (PET) was used as a component was autoclaved.

The nonwoven fabric was hot-shrinked with water at 100 ° C to prepare a shrinkable film having a shrinkage ratio of 12%.

The above-mentioned contraction was treated with a 10 wt% caustic soda aqueous solution to elute an alkali soluble polyester as a decomposition product to prepare a microfine nonwoven fabric having an average fineness of 0.3 denier.

The microfine nonwoven fabric was immersed in a 5 wt% aqueous solution of polyvinyl alcohol having a degree of saponification of 80 to 90%, taken out, squeezed using a mangle, and dried by hot air to perform a padding drying step.

Thereafter, the nonwoven fabric was immersed in a polyurethane elastic elastomer solution at a concentration of 15% by weight, which was obtained by dissolving polyurethane in a dimethylformamide (DMF) solvent, and a 25% by weight aqueous solution of dimethylformamide to prepare a polyurethane Solidified, and then washed with water.

Then, the polyvinyl alcohol was removed by treatment with hot water at 85 캜 containing 1% by weight of a surfactant and 0.2% by weight of acetic acid for 30 minutes to obtain a nonwoven fabric impregnated with 20% by weight of polyurethane.

Thereafter, the polyurethane-impregnated nonwoven fabric was subjected to thermal calendering using a roll heated to 130 ° C., and the surface of the nonwoven fabric impregnated with polyurethane was buffed using roughness # 150 sandpaper to form brushed , A three-color disperse dye was dyed in a dark gray color in a high-pressure rapid dyeing machine, and then washed to prepare an artificial leather.

[Example 2]

An artificial leather was produced in the same manner as in Example 1, except that the nonwoven fabric impregnated with 15 wt% of polyurethane was obtained in Example 1.

[Example 3]

An artificial leather was produced in the same manner as in Example 1, except that it was dyed with a deep blue color in Example 1.

[Example 4]

An artificial leather was produced in the same manner as in Example 1, except that a 10 wt% aqueous solution of polyvinyl alcohol was used in Example 1.

[Comparative Example 1]

Artificial leather was produced in the same manner as in Example 1, except that the elution step was carried out after the impregnation of the polyurethane polymer elastomer.

[Comparative Example 2]

Artificial leather was produced in the same manner as in Example 1, except that the padding drying treatment of polyvinyl alcohol was not carried out in Example 1.

[Comparative Example 3]

An artificial leather was produced in the same manner as in Example 1, except that the nonwoven fabric impregnated with 15 wt% of polyurethane was prepared without carrying out the padding drying treatment step of polyvinyl alcohol in Example 1.

[Comparative Example 4]

An artificial leather was produced in the same manner as in Example 1, except that the padding drying treatment step of polyvinyl alcohol was not carried out and a nonwoven fabric impregnated with 25 wt% of polyurethane was prepared.

[Comparative Example 5]

An artificial leather was produced using the same method as in Example 1, except that the production of a retractable cell in Example 1 was omitted.

The artificial leather produced in the above Examples and Comparative Examples was evaluated by the following evaluation method, and the evaluation results are shown in Table 1 below.

<Evaluation method>

1. How to measure color deviation

L, a, and b values were measured using a CCM machine, and the color of each part of the compartment was measured. Based on the average of L, a, and b values, ΔE The largest value indicates the maximum deviation.

2. Measurement method of daylight fastness deviation

Prepare a sample of artificial leather of 1,500 mm width and 1,500 mm width divided into nine equal parts.

The test equipment specified in ISO 105 or JIS L 0843 is to be tested under the conditions of a black panel temperature of 89 ± 3 ° C, a bath humidity of 50 ± 5% RH and an irradiance of 60 to 100 W / ㎡ (at 300 to 400 nm) The sample was irradiated until the cumulative light amount reached 84 MJ / m 2.

The difference between the unexposed and irradiated samples of the same sample is compared with the naked eye to determine the degree of discoloration of the same sample in gray scale to obtain a grade.

The difference between the lowest grade and the highest grade of each site is expressed as the maximum deviation of daylight fastness.

division 9 section color average
Maximum deviation (ΔE) 9 sections Daily light fastness
Average (grade) 9 sections Daily light fastness
Maximum deviation (Δ grade) Example 1 0.48 3 to 4 0.5 Example 2 0.42 3 to 4 0.5 Example 3 0.39 3 to 4 0.5 Example 4 0.46 3 to 4 0.5 Comparative Example 1 1.15 3 1.0 Comparative Example 2 0.99 3 1.0 Comparative Example 3 1.03 3 1.0 Comparative Example 4 1.24 2 to 3 1.5 Comparative Example 5 1.05 3 1.0

From the results in Table 1, it can be seen that when the padding drying treatment step of polyvinyl alcohol after elution is not carried out (Comparative Examples 2 to 4), or when elution is performed after the padding drying treatment step of polyvinyl alcohol (Comparative Example 1) The color difference of each part of the artificial leather is severely generated and a difference in the fastness of light is significantly generated. In the embodiment according to the present invention, it is confirmed that this phenomenon is improved.

This is due to the uniformity of the elastomer impregnated nonwoven fabric by allowing the elastomer to be uniformly impregnated by the padding of polyvinyl alcohol after elution of the sea component constituting the nonwoven fabric during the production of the artificial leather.

Claims (4)

Preparing a short fiber of a sea-island composite yarn capable of eluting a sea component from a nonwoven fabric;
Shrinking the nonwoven fabric;
Eluting the sea component of the sea-island type composite yarn to form a microfine nonwoven fabric;
Padding the microfine nonwoven fabric with polyvinyl alcohol to obtain a shape-stable nonwoven fabric;
Impregnating the shape-stable nonwoven fabric with a polymeric elastomer to obtain a polymeric elastomer-impregnated nonwoven fabric;
Removing the polyvinyl alcohol from the polymeric elastomer impregnated nonwoven fabric;
Buffing the surface of the nonwoven fabric to form a brushed surface; And
Dyeing the nonwoven fabric in a desired color;
A method for manufacturing an artificial leather having improved color and fastness deviation characteristics. The method according to claim 1,
Wherein a padding amount of the polyvinyl alcohol in the step of obtaining the shape-stable nonwoven fabric is 0.1 to 30% by weight. The method according to claim 1,
Wherein the polyvinyl alcohol is removed by hot water washing with water at 50 to 99 ° C. An artificial leather produced by the method according to any one of claims 1 to 3 and having improved color fastness and deviation characteristics with a light fastness (ISO 105 method, 84 MJ / ㎡ irradiation) of grade 3 or more.