KR102025343B1 - Embossed Release Paper for Synthetic Leather - Google Patents

Abstract

The present invention relates to embossed release paper for synthetic leather and a method for producing synthetic leather using the same. In particular, the present invention relates to embossed release paper for synthetic leather which, by using the release paper made of embossed textile material, can increase the peelability, can be used in a dry or wet process, and reduce manufacturing costs and a method for producing synthetic leather using the same.

Description

Embossed Release Paper for Synthetic Leather

The present invention relates to a release paper for synthetic leather embossing and a method for manufacturing a synthetic leather using the same, in particular, to form a embossing on the release paper of the fabric material to increase the peelability, to release the synthetic leather embossing release paper and the same It relates to a synthetic leather manufacturing method used.

Synthetic leather mainly containing vinyl chloride resin or polyurethane resin is generally produced using a release paper. Transferring embossing to such release paper can give a pattern to synthetic leather made using release paper.

Conventional techniques for producing synthetic leather using release paper are described in Korean Patent Publication No. 10-1210414. Embossed release paper for producing synthetic leather of 'Korean Patent Publication No. 10-1210414' is a synthetic leather comprising at least a paper serving as a support and an ionizing radiation cured film placed on the paper, and further embossing on the cured film. It is a manufacturing embossed release paper.

However, since the embossed release paper for preparing synthetic leather of 'Korean Patent Publication No. 10-1210414' should be provided with an ionizing radiation cured film on a paper serving as a support, there is a problem in that a raw material other than the support is additionally required, thereby increasing the manufacturing cost. In addition, since the paper is used as a support, when a tension is applied when the film is dried at a high temperature and then peeled, the release paper breaks, making it difficult to repeatedly use, and it is difficult to produce synthetic leather using a wet method.

Korean Patent Publication No. 10-1210414

The present invention has been made to solve the above-mentioned problems, and can transfer both embossed to synthetic leather, and can use both dry and wet methods, and release leather for synthetic leather embossing with excellent peeling property, and synthetic leather using the same The purpose is to provide a manufacturing method.

Release paper for synthetic leather embossing of the present invention for achieving the above object comprises a fabric that is a support and a coating applied to the fabric, the coating is embossed, the surface roughness of the embossed coating It is characterized by being 10 micrometers or less.

The material of the fabric may be characterized in that the polyester fiber 150 to 500 denier.

The release paper may be characterized in that the resin rupture process after applying the coating agent.

Synthetic leather manufacturing method using a synthetic leather embossed release paper of the present invention for achieving the above object is a manufacturing method using the release paper, step (a) of embossing the release paper and the resin solution on one side of the release paper (B) coating the film to a certain thickness, and (c) heating and drying the release paper and the resin solution or coagulating, washing and drying the resin paper, and (d) removing the dried resin solution from the release paper. It features.

The resin solution may be characterized by including a polyurethane resin and a cell regulator.

According to the release paper for synthetic leather embossing and the synthetic leather manufacturing method using the same according to the present invention has the following effects.

Since the fabric material is used as the support of the release paper, synthetic leather can be manufactured using a wet method or a dry method.

Since the fabric material is used as the support of the release paper, heat resistance and durability may be further improved.

Embossing can be performed directly on the support without further forming an additional layer necessary for embossing the fabric support, thereby simplifying the process and reducing the cost due to the additional layer formation.

Embossing can reduce the surface roughness of the release paper to less than 10μm can further improve the peelability.

1 is a release paper of synthetic leather embossed release paper according to a preferred embodiment of the present invention, and the synthetic leather prepared using the same.
Figure 2 is a synthetic leather embossed release paper according to a preferred embodiment of the present invention, and synthetic leather prepared using the same (left: pattern 1, right: pattern 2).
Figure 3 is a synthetic leather embossed release paper according to a preferred embodiment of the present invention, and synthetic leather prepared using the same (left: pattern 3, right: pattern 4).
Figure 4 is a weft surface roughness profile before the resin burst process of synthetic leather embossed 250 denier polyester oxford fabric release paper according to a preferred embodiment of the present invention.
Figure 5 is a gradient surface roughness profile before the resin burst process of synthetic leather embossed 250 denier polyester oxford fabric release paper according to a preferred embodiment of the present invention.
Figure 6 is a weft surface roughness profile after the resin rupture process of synthetic leather embossed 250 denier polyester oxford fabric release paper according to a preferred embodiment of the present invention.
Figure 7 is an inclined surface roughness profile after the resin burst process of synthetic leather embossed 250 denier polyester oxford fabric release paper according to a preferred embodiment of the present invention.
Figure 8 is a weft surface roughness profile after the pattern 1 embossing of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
Figure 9 is a gradient surface roughness profile after the pattern 1 embossing of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
10 is a weft surface roughness profile after the pattern 2 embossing of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
11 is a sloped surface roughness profile after the pattern 2 embossing of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
12 is a weft surface roughness profile after the pattern 3 embossing of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
Figure 13 is a gradient surface roughness profile after the embossed pattern 3 of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
Figure 14 is a weft surface roughness profile after the embossed pattern 4 of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
Figure 15 is a sloped surface roughness profile after the pattern 4 embossing of 250 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
Figure 16 is a weft surface roughness profile after pattern 2 embossing of synthetic leather embossed 150 denier polyester oxford fabric release paper according to a preferred embodiment of the present invention.
Figure 17 is a sloped surface roughness profile after the pattern 2 embossing of 150 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.
Figure 18 is a weft surface roughness profile after the pattern 2 embossing of synthetic leather embossed 500 denier polyester oxford fabric release paper according to a preferred embodiment of the present invention.
Figure 19 is a gradient surface roughness profile after the pattern 2 embossing of 500 denier polyester oxford fabric release paper for synthetic leather embossing according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the simple forms include plural forms unless the context clearly indicates the inverse.

As used herein, the meaning of “comprising” embodies a particular property, region, integer, step, operation, element, and / or component, and the presence of other specific property, region, integer, step, operation, element, and / or group. I do not exclude wealth.

In the present embodiment, the release paper comprises a fabric as a support and a coating applied to the fabric, wherein the fabric and the coating are embossed, and the roughness of the surface on which the resin solution for synthetic leather is applied after the embossing is 10 μm or less. It is characterized by.

The material of the fabric is preferably polyester (Polyester, PE), the polyester may be an Oxford (Oxford) fabric of 150 to 500 denier (D).

The release paper is subjected to a certain tension in the production process, and must withstand the high temperature state by heating of the oven and the low temperature state by the cooling ruler and be free of deformation. For this purpose, the release paper must have a certain strength or more, which affects the number of times the release paper is used in the production process.

Tensile strength of the polyester oxford fabric according to the denier is shown in Table 1.

The tensile strength 150D 250D 500D PE OXFORD slope ≥1000N ≥1200N ≥2000N Weft ≥700N ≥900N ≥1400N

The support of the release paper used in this embodiment is a polyester material, 250 denier oxford fabric.

As described above, because the release paper has to go through a high temperature production process, if the heat resistance is not good, there may be a problem in the production of the product. Synthetic leather produced in the present embodiment is a synthetic leather made of polyurethane material used in cosmetic puffs and the like. According to the manufacturing process of the synthetic leather of the polyurethane material, the release paper must withstand the heat treatment process for 10 to 15 minutes at up to 150 ℃.

Accordingly, the heat resistance test was performed at 150 ° C. for 1 hour. The results are shown in Tables 2-3.

Support The tensile strength Before heat treatment After heat treatment PE 250D OXFORD slope 1200 N 1200 N Weft 980 N 980 N

Support Elongation Before heat treatment After heat treatment PE 250D OXFORD slope 30 mm 34.7 mm Weft 35.5mm 36.9 mm

Coating is applied to polyester 250D oxford fabric to improve the peelability of the release paper.

The coating agent comprises 11.3 parts by weight of melamine-formaldehyde resin, 3 parts by weight of fabric softener, 3 parts by weight of ceramic resin, and 1 part by weight of catalyst, based on 100 parts by weight of water, and may be cured at 210 ° C.

When the coating agent is applied to the release paper and cured, since the coating agent penetrates between the release paper tissues or soaks to the back side, the touch of the release paper becomes poor and the surface roughness of the release paper also becomes poor.

In order to solve this problem, after the coating agent is applied, the resin is ruptured.

The resin rupture process is a process of uniformly processing the upper surface coating agent applied on the surface of the release paper with a plurality of guide blades, increasing the stretchability of the release paper, and making the surface roughness of the release paper stable. The related art is presented in Korean Patent Publication No. 10-1503649.

In order to determine the safety of the surface roughness of the release paper due to the resin rupture process, the surface roughness value of the release paper before embossing was measured according to the resin rupture.

The results are shown in Tables 4 to 5 and FIGS. 4 to 7. Cutoff values were based on 0.8 mm, Ra is the centerline mean value, Rt and Rmax are the maximum roughness.

Before resin burst Surface roughness (μm) Ra Rt Rmax Weft TEST 1 8.52 65.30 50.80 TEST 2 8.91 66.30 62.20 TEST 3 9.10 68.20 55.60 medium 8.84 66.60 56.20 slope TEST 1 11.70 72.70 62.70 TEST 2 13.90 79.40 71.00 TEST 3 13.80 78.00 69.40 medium 13.13 76.70 67.70

After resin burst Surface roughness (μm) Ra Rt Rmax Weft TEST 1 7.01 53.80 47.20 TEST 2 7.43 57.10 45.80 TEST 3 7.47 58.70 44.30 medium 7.30 56.53 45.77 slope TEST 1 9.96 62.10 58.20 TEST 2 8.14 55.40 48.70 TEST 3 9.91 61.80 57.90 medium 9.34 59.77 54.93

As can be seen in Tables 4 to 5, the surface roughness of the release paper may be more stable due to the resin bursting process. This affects the peel strength of the release paper, so that the more the surface roughness is stabilized, the better the peelability of the release paper.

Release paper is also important for smoothness. Smoothness indicates surface roughness and uniformity, which also affects the number of uses of release paper in the production process. The stiffness that can confirm the smoothness of the release paper can be determined by KS K 0642, 8.21.7: 2016 G method (Drap counting method), and the higher the value, the better the smoothness. If the stiffness is more than 0.8, it is suitable as a release paper of textile materials.

As a result of the experiment, the stiffness of the release paper coated with the coating agent was measured as 0.923 before the resin burst process and 0.953 after the resin burst process.

The experimental procedure for testing the peel strength of the release paper is as follows. The experiment was conducted based on the method of manufacturing synthetic leather using the wet method. The wet method is a method of coagulating, washing, and drying a synthetic leather resin solution applied to a release paper, and then peeling the dried resin solution from the release paper. In contrast, the dry method is a method of peeling the resin solution from the release paper after the drying is completed after the step of heating and drying the resin solution for synthetic leather applied to the release paper. As such, in the case of the dry method, there is a difference between the wet method and the manufacturing process, but the surface roughness and the change in peel strength according to the embossing are similar, and thus the wet method will be described.

First, a coating agent was applied to the support, and then embossed by transferring a metal embossing roll in which a concavo-convex shape of a specific pattern was formed on a release paper which had undergone a resin rupture process. Embosses were processed to a depth of 10 μm to 50 μm. At the time of embossing, it is preferable that the temperature of the said embossing roll is 165 degreeC. Unlike the above, a press method may be used for embossing.

For the experiment, the release paper was cut to a size of 25 mm in width and 150 mm in length.

The resin solution was apply | coated to one side of the embossed release paper by fixed thickness.

The resin solution was prepared by mixing 35 parts by weight of dimethylformamide (DMF) and 2 parts by weight of a cell regulator with respect to 100 parts by weight of polyurethane (Polyurethane, PU), followed by defoaming after mixing.

The resin solution was applied to the release paper at a thickness of 0.6 mm. In order to apply the resin solution to a certain thickness, 0.6 mm thick iron plates were respectively installed on both sides of the release paper, and the resin solution was raised between the iron plates by a predetermined amount, and then the resin solution was evenly distributed using a cylindrical rod. It was applied to release paper.

Thereafter, the release paper coated with the resin solution is placed in a coagulation bath and allowed to coagulate for 10 minutes. At this time, the temperature of the coagulation bath is preferably 20 ℃ to 40 ℃. At the time of the experiment, the temperature of the coagulation bath was set to 35 ° C. The solution of the coagulation bath may include 25 parts by weight of dimethyl formadi per 100 parts by weight of water. When dimethylformadi is contained in less than 20 parts by weight with respect to 100 parts by weight of the solution of the coagulation bath, or if the temperature of the coagulation bath is less than 20 ° C, the cell shape of the micropores increases, which may cause coagulation problems.

When the coagulation process is completed, the release paper is placed in a water bath to remove dimethyl form adide remaining in the coagulated resin solution for 10 minutes. At this time, it is preferable that the temperature of the said washing tank is 60 degreeC.

When the washing process is completed, the release paper is dried for 15 minutes at 120 ℃.

180 ° peeling experiment was carried out as shown in Figure 1 to the release paper completed the drying process. At this time, the peeling strength when the solidified resin solution was peeled at 180 ° using a tensile tester was measured.

First, in order to examine the improvement of peelability due to the resin bursting process, the peeling strength of the resin bursting process was tested three times. The third time means that the experiment of applying and peeling the resin solution on the same release paper was performed three times in succession. The results are shown in Table 6.

Peel Strength N / 25mm Width, 150mm / min 1 time Episode 2 3rd time Before resin burst 3.28 4.57 6.07 After resin burst 1.11 1.47 2.88

As shown in Table 6, it can be seen that the peel strength is stably maintained up to three times through the resin bursting process.

Hereinafter, the results of surface roughness measurement and peel strength test according to the pattern of the embossing formed on the release paper will be described.

2 to 3, surface roughness measurement and peel strength test were performed on the patterns 1 to 4 of the emboss.

Pattern 1 is a flat pattern with an embossing ratio of 100%.

Pattern 2 is an irregular pattern. Pattern 3 and Pattern 4 are regular patterns, Pattern 3 has an embossed rate of 35% and Pattern 4 has an embossed rate of 50%.

The result of measuring the surface roughness value of the pattern 1 is shown in Table 7 and FIGS. 8 to 9.

Pattern 1 Surface roughness (μm) Ra Rt Rmax Weft TEST 1 4.68 37.5 31.5 TEST 2 4.74 41.4 33.2 TEST 3 4.71 37.5 31.2 medium 4.71 38.8 31.9 slope TEST 1 6.53 34.9 38.6 TEST 2 6.56 40.8 38.4 TEST 3 6.53 41.0 38.7 medium 6.54 38.9 38.5

Comparing the surface roughness values in Table 7 with the surface roughness values in Table 5, it can be seen that the surface roughness values are more stable after embossing. In order to examine the stabilization of the surface roughness by the embossing in more detail, the results of measuring the surface roughness of the patterns 2 to 4 are shown in Tables 8 to 10 and 10 to 15.

Pattern 2 Surface roughness (μm) Ra Rt Rmax Weft TEST 1 9.11 58.2 49.2 TEST 2 8.33 55.0 52.6 TEST 3 7.24 82.3 42.3 medium 8.23 65.2 48.0 slope TEST 1 9.83 69.8 59.7 TEST 2 4.49 58.6 39.7 TEST 3 7.50 79.4 70.2 medium 7.27 69.3 56.5

Pattern 3 Surface roughness (μm) Ra Rt Rmax Weft TEST 1 7.90 51.9 48.8 TEST 2 6.32 51.6 43.7 TEST 3 5.59 50.8 47.0 medium 6.60 51.4 46.5 slope TEST 1 7.83 63.3 51.7 TEST 2 8.96 63.0 52.7 TEST 3 10.5 69.2 65.8 medium 9.10 65.2 56.7

Pattern 4 Surface roughness (μm) Ra Rt Rmax Weft TEST 1 4.36 53.6 27.9 TEST 2 5.73 56.0 39.1 TEST 3 6.05 73.2 38.6 medium 5.38 60.93 35.2 slope TEST 1 6.86 71.7 53.8 TEST 2 9.05 65.8 50.1 TEST 3 9.00 90.5 66.0 medium 8.30 76.0 56.63

As can be seen from the surface roughness values of Tables 7 to 10, the value of Ra, which is the surface roughness average value after embossing, is not significantly different from the value of Ra, which is the surface roughness average value of Table 5 before embossing. Particularly, in the case of patterns 1, 3, and 4, the surface roughness of Table 5 is lower than the Ra value. Referring to the surface roughness profiles of each of the patterns 1 to 4, as shown in FIGS. 8 to 15, the height of the unevenness of the surface roughness parameter of the embossed portion is less than 10 μm. That is, despite the embossing on the surface due to embossing, the surface roughness value affecting the peel strength is stabilized.

In addition, the surface roughness values were stabilized in order of pattern 2 (irregular), pattern 3 (35% embossing ratio), pattern 4 (embossing ratio 50%), and pattern 1 (embossing ratio 100%). The higher the ratio, the more stable the surface roughness.

As described above, when one of 150 to 500 denier polyester oxford fabric is used as a support for the release paper, the support of the release paper for the complex pattern 2 is a polyester 150 to check the surface roughness average Ra and the surface roughness profile. Or the surface roughness value measured when the 500 denier oxford fabric is shown in Tables 11 to 12 and 16 to 19.

Pattern 2 (150D) Surface roughness (μm) Ra Rt Rmax Weft TEST1 6.63 65.80 37.10 TEST2 4.35 69.40 37.20 TEST3 4.41 69.70 36.10 medium 5.13 68.30 36.80 slope TEST1 8.94 73.90 73.90 TEST2 7.41 82.10 82.10 TEST3 9.02 69.70 69.70 medium 8.46 75.23 75.23

Pattern 2 (500D) Surface roughness (μm) Ra Rt Rmax Weft TEST1 7.49 67.70 67.70 TEST2 6.94 104.00 100.00 TEST3 6.00 91.60 91.60 medium 6.81 87.77 86.43 slope TEST1 9.79 107.00 76.20 TEST2 8.21 79.60 79.60 TEST3 8.14 80.40 80.10 medium 8.71 89.00 78.63

As can be seen from the surface roughness values of Tables 11 to 12, the value of Ra, which is the surface roughness average value at 150 or 500 denier after embossing, is similar to or more stable than the value of the surface roughness average value Ra at 250 denier. . Looking at the surface roughness profile, as shown in FIGS. 16 to 19, when the height of the surface roughness parameter irregularities of the embossed portion is 150 and 500 deniers, they are all less than 10 μm.

In order to know the effect of the embossing on the peel strength, the results of measuring the peel strength of the patterns 1 to 4 three times are shown in Table 13.

Peel Strength N / 25mm Width, 150mm / min 1 time Episode 2 3rd time Pattern 1 0.91 1.12 1.56 Pattern 2 1.95 2.98 3.5 Pattern 3 2.26 2.98 3.8 Pattern 4 1.16 1.52 2.9

Comparing the peel strength values of the pattern 1 of Table 13 with the peel strength values after the resin burst of Table 5, it can be seen that the peel strength values after the embossing process are more stable.

It can be seen that the peel strength value of the pattern 4 of Table 13 is formed similarly to the peel strength value after the resin rupture of Table 5. That is, even when the surface of the release paper is formed through the embossing process, it is possible to minimize the impact on the peel strength due to the stabilization of the surface roughness through the embossing process.

Patterns 2 to 3 are embossed patterns that are more complex than pattern 4, and it can be seen that the peel strength of patterns 2 to 3 is higher than that of pattern 4. Peel strength can produce products stably when coming out below 3N / mm. Therefore, it can be seen that even in the case of the pattern 2 to the pattern 3 having a complicated pattern, the product can be stably generated up to two times.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art without departing from the spirit and scope of the invention described in the claims various modifications or variations It can be carried out.

Claims (5)

A support provided with a fabric,
It includes a coating applied to the support,
After the coating agent is subjected to a resin rupture process,
And a concave-convex shape formed by heating and pressing the resin ruptured surface to deform the support and the coating agent.
Release paper for synthetic leather embossing, characterized in that the roughness of the uneven surface is 10μm or less. delete delete delete delete

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