KR102359888B1 - Manufacturing method of polyurethane synthetic leather using mesh cloths - Google Patents

Abstract

The present invention is characterized in that the water-based polyurethane resin is coated twice on the surface of the mesh fabric. That is, (i) the two-component polyurethane adhesive resin and the additive solution are mixed with the mesh fabric at a viscosity of 2,500-3,500 cps (centipoise), and after mixing, the depth is 200-300㎛ and the size of the engraved hole (4d) is 100 The process of first coating with a coating amount of 100-150 g/m2 using a gravure printing roll of ~140 mesh and drying in a hot air chamber at 120-140°C; and (ii) one-component polyurethane skin layer resin and additive solution at a viscosity of 2,500-3,500 cps (centipoise), after mixing and toning, the depth is 200-300㎛ and the size of the intaglio hole (4d) is 100-140 mesh A process of secondary coating at a coating amount of 100-150 g/m2 using an in-gravure printing roll and drying in a hot air chamber at 120-140° C.; It is characterized in that it contains
Polyurethane synthetic leather prepared by the present invention is not coated on the mesh hole of the fabric, but polyurethane is coated only on the fibrous tissue portion, so that air permeability can be maintained. In addition, as the abrasion resistance and adhesive strength of the fabric are improved, there is no shortage as a material for the outer material of shoes, and it is possible to realize a two-tone surface color in terms of design. In addition, it is possible to realize a hologram effect and three-tone color by a special pearl pigment that cannot be expressed in fabric.

Description

Manufacturing method of polyurethane synthetic leather using mesh fabric {Manufacturing method of polyurethane synthetic leather using mesh cloths}

The present invention relates to a method for producing polyurethane synthetic leather with excellent breathability by applying a mesh (MESH) fabric, and more specifically, to a fiber of a fabric having a mesh hole (hereinafter referred to as “mesh fabric”) It relates to a method of manufacturing synthetic leather that selectively coats only the tissue part with polyurethane to improve the abrasion resistance and adhesive strength of a mesh fabric while maintaining air permeability.

According to the manufacturing method of polyurethane synthetic leather to which the mesh fabric of the present invention is applied, an eco-friendly water-based polyurethane resin is selectively coated on only the fiber tissue part of the mesh fabric to maintain air permeability, while preserving the inherent textile structure of the mesh fabric. By designing different polyurethane colors and fabric colors, two-tone colors can be realized, and synthetic leather with improved abrasion resistance and adhesive strength can be manufactured.

There are double raschel mesh fabrics and single raschel mesh fabrics as mesh fabrics that have been widely used as materials for shoes recently. Double lacquer is mainly knitted with polyester yarn, and in the processing process, one side has a mesh hole and the other side is composed of a flat fabric texture, so it has a three-dimensional textile texture and volume. It is special in terms of design and has more air permeability.

In Korean Patent No. 10-2009720, a mixture of a polyurethane resin for film formation and a polyurethane resin for adhesive is coated on a release paper, dried, and then laminated with a mesh fabric to form a film layer of the mixed coating solution on the mesh fabric, and the release paper is peeled off. Then, another release paper with a pattern and the film layer of the mixed coating solution are laminated in contact with each other, heat-treated to transfer the release paper pattern, and then the release paper is peeled off to dry-coat the mesh fabric. In the prior art, although there is an advantage of implementing a pattern of a release paper on the surface, a process of physically removing the film layer of the mixed coating solution remaining in the hole portion of the mesh fabric is essential to ensure the desired air permeability. In addition, manufacturing cost increases by using two different types of release paper, and organic solvents remain in the product by applying solvent-type polyurethane, which is not environmentally friendly.

In order to solve this problem, in the present invention, polyurethane is coated directly on the surface of the mesh fabric using a gravure printing roll designed to be used semi-permanently without using a release paper. An object of the present invention is to provide a method for manufacturing synthetic leather. In addition, we want to fundamentally block the harmful problem of organic solvents by applying eco-friendly water-based polyurethane without using solvent-type polyurethane.

In order to solve this problem, in the present invention, (i) a two-component polyurethane adhesive resin and an additive solution are mixed with a mesh fabric at a viscosity of 2,500 to 3,500 cps (centipoise), and after mixing, the depth is 200 to 300 μm. Using a gravure printing roll with a engraved hole (4d) of 100 to 140 mesh, the first coating at a coating amount of 100 to 150 g/m2 and drying in a hot air chamber at 120 to 140 ° C. and (ii) one-component polyurethane After mixing and toning the resin and additive solution for the skin layer at a viscosity of 2,500-3,500 cps (centipoise), use a gravure printing roll with a depth of 200-300㎛ and engraving hole (4d) of 100-140 mesh. Polyurethane synthetic leather is manufactured by performing the second coating at a coating amount of ~150g/m2 and drying in a hot air chamber at 120~140℃ in sequence.

When synthetic leather products for footwear are manufactured by the manufacturing method of the present invention, the abrasion resistance and adhesive strength of the mesh fabric are improved while maintaining the air permeability of the mesh fabric. Until now, a single-colored mesh fabric has been used for shoes (for UPPER), but if the polyurethane partial coating method of the present invention is applied, a two-tone color surface effect can be realized, and when a special pearl pigment is added, a hologram effect and A design effect that can realize three-tone color can be obtained. In addition, by coating an eco-friendly water-based polyurethane, an organic solvent is not required during the manufacturing process and it does not remain in the finished product, so it can meet the recent eco-friendly trend. As a result, the synthetic leather of the present invention is a material in which the concepts of textile and synthetic leather are combined, and is useful as an outer material for shoes.

1 is a schematic view of a process of coating a water-based polyurethane resin compounding solution on a mesh fabric or a mesh fabric with a primary coating of an aqueous type polyurethane resin compounding solution using a gravure printing roll.
Figure 2 is a perspective schematic view of the gravure printing roll used in the present invention.
Figure 3 is a surface photograph of the mesh fabric used in Example 1 (a water-based polyurethane resin blending solution is not coated).
4 is a photograph of the surface of the polyurethane synthetic leather prepared in Example 1.
5 is a photograph of the surface of the mesh fabric used in Example 2 (a state in which the aqueous type polyurethane resin blending solution is not coated).
Figure 6 is a photograph of the surface of the polyurethane synthetic leather prepared in Example 2.
7 is a photograph of the surface of the mesh fabric used in Comparative Example 2 (a state in which the aqueous type polyurethane resin blending solution is not coated).
8 is a photograph of the surface of the dry polyurethane synthetic leather prepared in Comparative Example 2.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention is characterized in that the surface of the mesh fabric is coated with a water-based polyurethane resin twice.

Specifically, the present invention (i) a two-component water-based polyurethane adhesive resin and an additive solution to a viscosity of 2,500 to 3,500 centipoise (CPS) to prepare a first water-based type polyurethane resin compounding solution by mixing and toning , Depth of gravure inner printing roll indicating the distance from the outer surface of the central portion 4a of the gravure printing roll engraved with intaglio holes 4d to the outer surface of both end portions 4b of the gravure printing roll on which intaglio holes 4d are not engraved (4c) is 200 ~ 300㎛ and the size of the intaglio hole (4d) is 100 ~ 140 mesh (mesh) using the gravure printing roll (4) to the mesh fabric using the first aqueous type polyurethane resin compounding solution A process of first coating with an application amount of 100 g/m 2 to 150 g/m 2 and drying in a hot air chamber 6 at 120 to 140° C.; and (ii) a one-component water-based polyurethane skin resin and additive solution to a viscosity of 2,500 to 3,500 centipoise (CPS) to prepare a second water-based polyurethane resin compounding solution, and then to the engraved hole ( The depth (4c) of the gravure printing roll indicating the distance from the outer surface of the central portion (4a) of the gravure printing roll engraved with 4d) to the outer surface of the both end portions (4b) of the gravure printing roll in which the intaglio holes (4d) are not engraved Using a gravure printing roll 4 having a size of 200 to 300 μm and the intaglio hole 4d of 100 to 140 mesh, the first aqueous type polyurethane resin blending solution is first applied to the mesh fabric. 2, the second application of the aqueous type polyurethane resin blending solution at an application amount of 100 g/m 2 to 150 g/m 2 and drying in a hot air chamber 6 at 120 to 140° C.; characterized in that it includes.

In the step (i), the two-component polyurethane resin is a water-dispersible polyurethane resin for an adhesive of a copolymerization type of polyester and polyether. It is suitable that the solid content is about 40% and the 100% modulus is 10-20 kg/cm 2 . The blending ratio of the first aqueous type polyurethane resin blending solution is 0 to 10 parts by weight of water, 0 to 2 parts by weight of a cellulosic thickener, 5 to 10 parts by weight of a curing agent, 5 to 15 parts by weight of a pigment toner based on 100 parts by weight of the resin for adhesive. It consists of parts by weight, 0.2 to 1.0 parts by weight of an antifoaming agent, and 1 to 5 parts by weight of an anti-tacky agent. In order to obtain an appropriate viscosity for coating, it is necessary to appropriately control the amount of water added and the amount of the thickener added.

The resin and curing agent of the resin compounding solution for adhesive used in the step (i) may be the same as the resin and curing agent used in the general synthetic leather dry process. However, it is different only in controlling the viscosity in order to apply the gravure printing method rather than the knife coating. In the present invention, a copolymer-type polyurethane resin was applied in order to secure a level of hydrolysis resistance that can be used for footwear.

In the step (ii), the one-component polyurethane skin layer resin is a polyether-type water-dispersible resin with a solid content of about 35% and a 100% modulus of 40-50 kg/cm 2 . The blending ratio of the second water-based polyurethane resin blending solution is 0-20 parts by weight of water, 0-2 parts by weight of a cellulosic thickener, 10-20 parts by weight of a pigment toner, 0.2-1.0 parts by weight of an antifoaming agent based on 100 parts by weight of the resin. , 1 to 5 parts by weight of the anti-stick agent. The polyurethane resin for the skin layer used in the process (ii) is the same as the resin used in general dry synthetic leather, but an ether-type polyol is used to secure the hydrolysis resistance and abrasion resistance for footwear. The modulus of the resin was adjusted in consideration of

Put the coating compounding solution made in the step (i) into the aqueous polyurethane resin compounding solution bath 2 of FIG. If the thickness of the mesh fabric to be used is 1.2 mm, set the interval between the gravure printing roll 4 and the back roll 5 to 0.5 to 0.7 mm, which is about 40 to 60% of the thickness of the mesh fabric. At this time, since the depth (4c) of the gravure printing roll is 200-300 μm, the application amount of the compounding solution to be coated is about 100-150 g/m2 based on the solution before drying, and 100-140 mesh engraved inside the gravure printing roll (4). (mesh) The engraved hole (4d) serves to help the viscous compounding solution to be well transferred and coated on the textile fabric. After coating, dry it in a hot air chamber at a temperature of 120~140℃. Line speed leads to complete drying at a speed of 5-10 m/min. Here, the reason for adjusting the gap between the gravure printing roll 4 and the back roll 5 to 40 to 60% of the thickness of the mesh fabric is that the blending solution does not penetrate into the hole of the mesh fabric due to the pressure of the two rolls, and the fiber texture of the surface It serves to enable partial coating of only the part.

The fabric coated with the adhesive layer is moved back to the introduction part. The aqueous polyurethane resin blending solution for the one-component skin layer prepared in step (ii) is put into the aqueous polyurethane resin blending bath 2 of FIG. 1, coated under the same conditions as in step (i), and completely dried.

The manufacturing method of polyurethane synthetic leather according to the present invention uses a method of coating directly on a textile fabric, unlike the transfer method using a conventional release paper, so that the process is simple and the manufacturing cost is greatly reduced. Also, a water-based type polyurethane resin is used. Therefore, it is possible to manufacture eco-friendly products that are recently required by shoe brands.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples.

Example 1

Prepare a red colored polyester double lacquer fabric (mesh fabric) with an oval mesh hole.

7 parts by weight of a curing agent, 0.5 parts by weight of a thickener, 10 parts by weight of an aqueous black pigment, 0.5 parts by weight of an antifoaming agent and 2 parts by weight of an anti-tack agent were added to 100 parts by weight of a two-component water-based polyurethane resin, and stirred uniformly to form the first water-based type poly A urethane resin compounding solution (for adhesive) is prepared.

Next, from the outer surface of the central portion 4a of the gravure printing roll engraved with intaglio holes 4d as shown in FIG. The first water-based type as shown in FIG. 1 on the mesh fabric by using the gravure printing roll 4 having a depth 4c of the gravure printing roll indicating the distance of 220 μm and a size of the intaglio hole 4d of 110 mesh. The polyurethane resin compounding solution was first applied at a coating amount of 120 g/m 2 and dried in a hot air chamber 6 at 125° C.

Next, 1 part by weight of a thickener, 20 parts by weight of an aqueous black pigment, 1 part by weight of an antifoaming agent, and 3 parts by weight of an anti-tack agent are added to 100 parts by weight of a one-component aqueous polyurethane resin, and the second aqueous type polyurethane resin is mixed by uniformly stirring. Prepare liquid (for skin).

Next, from the outer surface of the central portion 4a of the gravure printing roll engraved with intaglio holes 4d as shown in FIG. The first water-based type polyurethane resin compounding solution was first applied using the gravure printing roll 4 having a depth of 4c of the gravure printing roll indicating the distance of 220 μm and a size of the intaglio hole 4d of 110 mesh. As shown in FIG. 1, the mesh fabric was secondarily applied at an application amount of 120 g/m 2 of the aqueous type polyurethane resin blending solution and dried in a hot air chamber 6 at 125° C. to prepare a polyurethane synthetic leather to which the mesh fabric was applied.

The results of evaluation of the properties of the prepared polyurethane synthetic leather are shown in Table 1, the surface photograph of the mesh fabric applied to the polyurethane synthetic leather production is as shown in FIG. 3, and the surface photograph of the prepared polyurethane synthetic leather is as shown in FIG.

Example 2

Prepare a light green colored polyester double lacquer fabric (mesh fabric) with mesh holes.

7 parts by weight of a curing agent, 0.5 parts by weight of a thickener, 10 parts by weight of an aqueous orange pigment, 0.5 parts by weight of an antifoaming agent, and 2 parts by weight of an anti-tack agent were added to 100 parts by weight of a two-component water-based polyurethane resin and stirred uniformly to form the first water-based poly A urethane resin compounding solution is prepared.

Next, from the outer surface of the central portion 4a of the gravure printing roll engraved with intaglio holes 4d as shown in FIG. The first water-based type as shown in FIG. 1 on the mesh fabric by using the gravure printing roll 4 having a depth of 4c of the gravure printing roll indicating the distance of 280 μm and a size of the intaglio hole 4d of 130 mesh. The polyurethane resin compounding solution was first applied at a coating amount of 140 g/m 2 and dried in a hot air chamber 6 at 135° C.

Next, 0.5 parts by weight of a thickener, 15 parts by weight of an orange aqueous pigment and fluorescent pigment, 0.8 parts by weight of an antifoaming agent, and 3 parts by weight of an anti-tack agent are added to 100 parts by weight of a one-component water-based polyurethane resin and uniformly stirred to form a second aqueous type poly A urethane resin compounding solution (for skin) is prepared.

Next, from the outer surface of the central portion 4a of the gravure printing roll engraved with intaglio holes 4d as shown in FIG. The first water-based type polyurethane resin compounding solution was first applied using the gravure printing roll 4 having a depth of 4c of the gravure printing roll indicating the distance of 280 μm and a size of the intaglio hole 4d of 130 mesh. As shown in FIG. 1, the aqueous type polyurethane resin blending solution of 2 above was applied to the mesh fabric at a coating amount of 140 g/m2 and dried in a hot air chamber 6 at 135° C. to prepare a polyurethane synthetic leather to which the mesh fabric was applied. .

The results of evaluation of the properties of the prepared polyurethane synthetic leather are shown in Table 1, the surface photograph of the mesh fabric applied to the polyurethane synthetic leather production is as shown in FIG. 5, and the surface photograph of the prepared polyurethane synthetic leather is as shown in FIG.

Comparative Example 1

In Example 1, instead of the first water-based type polyurethane resin compounding solution (for adhesive) used in the first application in Example 1, the second water-based type polyurethane resin compounding (for skin) used in the second application in Example 1 was used. A polyurethane synthetic leather was prepared in the same manner as in Example 1 except that it was used.

In other words, in Comparative Example 1, the second water-based type polyurethane resin formulation (for skin) used in the second application in Example 1 was used in both the primary and secondary applications.

The evaluation of the properties of the prepared polyurethane synthetic leather was shown in Table 1.

division Example 1 Example 2 Comparative Example 1 How to measure Adhesive strength (kg/cm) 3.20 3.41 1.04 ASTM D2724 Wear strength (cycle)
(Taber, H-18, 500g) 2,000 2,000 1,400 ASTM D3884 Bally Flex 100,000 times 100,000 times 80,000 times NIKE-11 Color fastness (class)
(Color fastness)
(UV, 50℃*24HRS) 4th grade 4th grade 4th grade ASTM G154 hydrolysis resistance
(Hydrolysis)
(10%NaOH*25℃*24HRS) Pass Pass Pass NIKE-57

Examples 1 and 2 showed adhesive strength suitable for the outer material for shoes, but it can be seen that the adhesive strength of Comparative Example 1 was remarkably low. In addition, Examples 1 and 2 showed results that satisfy all of the important physical properties of the material for shoes, such as surface abrasion strength, flexibility, and hydrolysis resistance.

Comparative Example 2

A general polyurethane dry coating process using a release paper was applied. That is, 150g/m2 of the colored one-component polyurethane resin compounding solution is first coated on the release paper based on the solution and dried, and the second two-component polyurethane adhesive compounding solution is coated with 150g/m2 of the solution based on the solution, and then half-baked with hot air at 120°C. After drying, laminate the fabric with mesh holes (mesh fabric) and apply pressure. Then, after aging for 48 hours in an aging room at 60° C., the release paper was peeled off to prepare a polyurethane-coated dry synthetic leather. In this case, as shown in FIG. 8 , the polyurethane forms a film layer that covers all the mesh holes, so air permeability is naturally lost, and it was impossible to selectively remove the film layer of the hole portion.

A photograph of the surface of the prepared mesh fabric applied to the production of dry synthetic leather is as shown in FIG. 7 , and a photograph of the surface of the prepared dry synthetic leather is as shown in FIG. 8 .

1: Supply roller of mesh fabric or mesh fabric coated with water-based polyurethane resin mixture
2: Water-based polyurethane resin mixture bath
3: Polyurethane resin compounding solution
4: gravure printing roll
5: Back roll
6: hot air chamber
7: A winding roller of a mesh fabric first coated with a water-based polyurethane resin compounding solution or polyurethane synthetic leather (finished product) coated with a water-based type polyurethane resin compounding solution secondary.
4a: the central part of the gravure printing roll 4 on which the intaglio holes 4d are engraved
4b: both ends of the gravure printing roll 4 in which the intaglio holes 4d are not engraved
4c: Distance from the outer surface of the central portion (4a) of the gravure print roll to the outer surface of both end portions (4b) of the gravure print roll (depth of the gravure print roll)
4d: Engraved hole

Claims (4)

(i) Two-component water-based polyurethane adhesive resin and additive solution were mixed with a viscosity of 2,500 to 3,500 centipoise (CPS) to prepare the first water-based polyurethane resin compounding solution, and then engraved hole (4d) The depth (4c) of the gravure inner printing roll indicating the distance from the outer surface of the central portion (4a) of the gravure printing roll engraved to the outer surface of the both end portions (4b) of the gravure printing roll in which the intaglio holes (4d) are not engraved is 200~ Using a gravure printing roll 4 having a size of 300 μm and the intaglio hole 4d of 100 to 140 mesh, 100 g/m 2 to 150 g/ The process of first coating with an application amount of ㎡ and drying in a hot air chamber 6 at 120 to 140° C.; and
(ii) One-component water-based polyurethane skin resin and additive solution were mixed and toned at a viscosity of 2,500 to 3,500 centipoise (CPS) to prepare a second water-based type polyurethane resin compounding solution, and then engraved holes (4d) ), the depth (4c) of the gravure printing roll indicating the distance from the outer surface of the central portion (4a) of the gravure printing roll engraved to the outer surface of the both end portions (4b) of the gravure printing roll on which the intaglio holes (4d) are not engraved is 200 ~300㎛ and the size of the intaglio hole (4d) using a gravure printing roll (4) of 100 to 140 mesh (mesh), the first water-based type polyurethane resin compounding solution is first applied to the mesh fabric, the second The process of applying the aqueous type polyurethane resin mixture of 100g/m2 to 150g/m2 in an application amount of 100g/m2 and drying it in a hot air chamber 6 at 120~140℃ Polyurethane to which a mesh fabric is applied, comprising: A method for manufacturing synthetic leather. The method of claim 1, wherein the two-component water-based polyurethane adhesive resin and the one-component water-based polyurethane skin resin are water-dispersible polyurethane resins. The method of claim 1, wherein the additive solution comprises a curing agent, a thickener, an aqueous pigment, an anti-foaming agent and an anti-tack agent. The method according to claim 1, wherein the gap between the gravure printing roll (4) and the back roll (5) is adjusted to 40-60% of the thickness of the mesh fabric while positioning the back roll (5) on the directly upper end of the gravure printing roll (4). Method of manufacturing polyurethane synthetic leather to which mesh fabric is applied, characterized in that it gives.

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