KR101152380B1 - Synthetic Leather Manufacturing Method having a Air Permeability - Google Patents

Abstract

The film is formed by applying a water-soluble PU resin solution directly to the surface of the fabric, but it has a breathability by allowing to leave a small gap formed in the fabric partially, and also strengthens the bonding force between the fabric and the film to prevent the film from peeling off or separating. At the same time, a method of manufacturing artificial leather having air permeability which can improve the durability and texture of a coating is disclosed.
The present invention is a brush-forming step of raising the surface tissue of the fabric to a napping machine to make them fluff; A back surface reinforcing step of reinforcing the back structure of the fabric by applying an appropriate amount of a flame retardant resin coating agent to ensure flame retardancy on the back of the fabric; And a film forming step of forming a film on the surface of the fabric by applying a water-soluble PU resin solution of 50 to 60 g / m 2 on the brush formed on the surface of the fabric, wherein the film forming process includes the total coating amount of the water-soluble PU resin solution. A first coating step of applying 80 to 84% of the medium, a smoothing step of making the surface smooth by uniformly drying the surface of the fabric by heating (130 ° C. to 160 ° C.) after the first coating step, and the smoothing step It consists of a 2nd coating process of apply | coating the remaining 16-20% of water-soluble PU resin solution after that.

Description

Synthetic Leather Manufacturing Method having a Air Permeability

The present invention relates to a method of manufacturing artificial leather, and more particularly, to a method of manufacturing artificial leather having breathability like natural leather and at the same time improving the binding force between the fabric and the film and the texture of the film.

In general, artificial leather is manufactured by using a fabric, knitted fabric or non-woven fabric as a fabric, by forming a film with synthetic resin such as PVC or PU (polyurethane) on one surface of the fabric, and then embossing the leather pattern on the film, Dry and wet methods are largely known as a method of forming a film on the fabric.

In the dry method, a polyurethane stock solution or a solvent-type polyurethane (toluene, melted polyurethane in MEK) resin is applied to a surface of a release paper, for example, a solvent-type polyurethane (PU) solution to RP (RELEASE PAPER; release paper). By drying, then releasing the release paper and the adhesive-coated fabric, followed by drying and bonding to release the release paper from the coating to form a coating on the fabric.

In addition, the wet method uses a method such as gravure on a fabric (woven fabric, knitted fabric, nonwoven fabric) padded with a resin that can form a film on the fabric surface or the entire fabric, for example, a solvent type PU resin or impregnated with a synthetic resin. There is a method in which a PU resin is applied to the surface to form a film, and a release paper is adhered thereon to apply a wet + dry method.

However, since the artificial leather produced by the above-described conventional method, as shown in the photographs of Figs. 7A and 7B, 8A and 8B, after forming all of the film, the film is bonded to the surface of the fabric with an adhesive, The surface of the fabric is completely blocked by the film, so there is no breathable effect like natural leather. In addition, since the film is adhered to the surface of the fabric with an adhesive, it is difficult to adhere uniformly to the whole surface, and the weak adhesive force is easily separated or peeled off from the fabric, and the bonding strength between the fabric and the film is weak. Durability is reduced, such as cracks are generated, and there is a serious disadvantage in environmental problems by using a lot of solvents (toluene, MEK) harmful to humans and VOC compounds generated by the use of adhesives.

The present invention is to solve the conventional problems as described above, the purpose is to form a film by applying a water-soluble synthetic resin solution directly to the surface of the fabric, to have a breathable by leaving a small gap formed in the fabric partially In addition, it is to provide a method of manufacturing artificial leather having a breathable to improve the durability and texture of the coating and at the same time to prevent the peeling or separation of the coating by strengthening the bonding force of the fabric and the coating.

Method for producing a breathable artificial leather of the present invention for achieving the above object is, raising the surface structure of the fabric to the napping machine (起毛 機) raising the lint forming process; A back surface reinforcing step of applying a water-soluble flame retardant resin coating agent to the back surface of the fabric to strengthen the back structure of the fabric and impart flame retardancy; And a film forming step of coating a 50-60 g / m 2 water-soluble PU resin solution on the surface of the fabric formed on the surface of the fabric to form a film on the surface of the fabric.

At this time, the film forming step is the first coating step of applying 80 to 84% of the total coating amount of the water-soluble PU resin solution, and dried (130 ℃ ~ 160 ℃) after the first coating step by heating and pressing the surface of the fabric It is preferable that it consists of the smoothing process which makes surface smoothness uniform, and the secondary coating process which apply | coats the remaining 16-20% water-soluble PU resin solution after the said smoothing process.

In addition, the present invention is a softener attaching step of imparting flexibility to the surface of the fabric by immersing the fabric in a storage tank containing a flexible manufacturing solution diluted with a softener in water prior to the brushing step to attach the softener and then dry, the film forming process Thereafter, a pattern forming process for embossing the film on the surface of the fabric surface to form a pattern, and a painting process for imparting color by spraying a resin solution diluted with pigment on the film surface after the pattern forming process, and the painting process Thereafter, the method further includes a surface strengthening process of spraying a top protect resin to increase heat resistance and cold resistance durability on the surface of the coating.

According to the present invention having the above characteristic configuration, after forming the brush on the surface of the fabric, by coating a water-soluble PU resin solution on the brush to form a film directly, the space is partially filled without filling all the space between the brushed By setting the coating amount of the resin solution within the appropriate amount so as to ensure, it can be breathable by the partially secured space, and at the same time by directly applying the resin solution to the surface of the fabric to penetrate between the napping and between the fabric and the film Improved bonding force prevents the separation and peeling of the fabric and the film, strengthens the film's durability, minimizes the occurrence of cracks, and maintains the texture of the film well. It has the effect of improving quality.

In addition, the present invention, the water-soluble PU resin in the film forming process is applied by dividing the primary and secondary, in the first coating process, the resin solution penetrates into the space between the brushed to lower the binding force, and then the surface is uniformly heated and pressurized By performing the smoothing process to make sure that the resin solution penetrates into the space between the brushed and smoothed the surface, the next secondary coating process is carried out, so that the texture of the coating formed on the brushed fabric is uniform. Can further improve the surface quality.

In addition, the present invention, by forming a softener on the surface of the fabric before attaching a softening agent to give flexibility to the surface of the fabric is easy to form the brushed by the brush, after the film forming step, forming a pattern on the film and , The coating process to impart color by spraying the diluted resin liquid to the surface of the coating and the surface strengthening process of spraying the top protective resin on the surface of the coated film are performed sequentially, thereby further improving the quality of the artificial leather There is.

1 is a block diagram for explaining a method of manufacturing artificial leather according to the present invention.
(A) to (d) is a process diagram schematically showing each process of the present invention.
Figure 3a and Figure 3b is a photograph of the surface before and after the brushing step in the production method of the present invention.
Figure 4 is a back photo of the fabric coated with a flame-retardant resin coating in the back surface strengthening process of the present invention.
5a and 5b is a surface and cross-sectional photograph of the artificial leather produced by the manufacturing method of the present invention.
6a and 6b is a surface and cross-sectional photograph of the natural leather treated with a color spray and top protect spray on the surface.
7A and 7B are surface and cross-sectional photographs of artificial leather manufactured by forming a polyurethane film by a conventional manufacturing method.
8a and 8b is a surface and cross-sectional photograph of the artificial leather produced by forming a PVC film in a conventional manufacturing method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, the method of manufacturing artificial leather having air permeability according to the present invention includes a softening agent attaching step (S1), a brush raising step (S2), a back surface strengthening step (S3), and a film forming step (S4). The fabric used in the manufacture of artificial leather has many gaps between the ol and ol, and is used for knitting (Tricot, etc.) or fabrics and non-woven fabrics, which are highly breathable and easy to form brushed surfaces.

First, the softening agent attaching process (S1) is a process before forming brushing on the surface of the fabric, that is, the surface for forming the film, and gives flexibility to the surface of the fabric so that the brushing operation is made easier. As shown in FIG. 2 (a), a softening agent 11, in which a softening agent, for example, a WAX-based or silicone-based softener, is diluted in water, is contained in a storage tank 12, and the fabric W is immersed in an oil-forming liquid. It is made by drying after attaching a softening agent.

Subsequently, after raising the softening agent attaching process S1, the raising formation step S2 is carried out by raising the surface structure of the fabric W to a brushing machine, for example, brushing fillers, to make them fluff. As a step of forming a loop-shaped napping, as shown in (b) of FIG. 2, the napping cloth 20 formed on the drum 22 with the needle 21 bent in a predetermined direction is fabricated ( By rotating at a high speed while being in contact with the surface of W), as shown in FIG. 3A and the picture after raising the brush of FIG. This brushing forming step (S2) is repeated several times to maintain the uniformity of the brushed over the entire surface of the fabric (W) to the maximum.

Subsequently, the back surface strengthening step (S3) is a flame-retardant coating agent 31, for example bromine or phosphorous flame-retardant resin on the back surface of the fabric (W), as shown in (c) of FIG. It is applied to the back surface of the fabric (W) by coating with a coating machine 32, when the flame-retardant coating agent is coated on the back of the fabric (W) to cure, the back structure of the fabric is harder than before to increase the flexibility of the fabric (W) By weakening, it is easy to keep the fabric W flat, thereby preventing the resin from being applied unevenly when the resin solution is applied to the surface of the fabric W, and the flame retardant coating agent imparts flame retardancy to the fabric. It also performs the function.

At this time, the coating amount of the flame retardant coating agent 31 is the amount to obtain flame retardancy (combustion rate) of 80 mm / min or less by the FMVSS 302 test method as shown in the photograph of FIG. It is preferable to ensure the air permeability of the fabric (W) by preventing the gap between the ol and the fabric of the fabric. For example, in the case of coating in a too small amount, the function of strengthening the back structure of the fabric (W) and the flame retardant function is reduced, it is difficult to fully perform the function, in the case of coating in a large amount of flame retardant coating agent (31) Can penetrate into the gap between the ol and the fabric of the fabric (W) may worsen the breathability.

Subsequently, in the film forming step (S4), after the back surface strengthening step (S3), the water-soluble PU resin solution is applied onto the brush formed on the surface of the fabric W to coat the film P on the surface of the fabric W. In order to form, the coating amount of the water-soluble PU resin solution is within the range of 50 ~ 60g / ㎡ to improve the texture of the film (P) as shown in the photo of Fig. 5a and 5b, and at the same time so as not to fill all the space between the brushed It is desirable to partially secure the space to have breathability, and thus, it is possible to manufacture artificial leather having characteristics similar to the breathability and surface texture of natural leather as shown in the photographs of FIGS. 6A and 6B.

For example, if the coating amount is applied too small, most of the resin solution penetrates between the raising of the fabric (W), making it difficult to form a uniform coating on the raising, which has a disadvantage of lowering the texture of the coating. In addition, if the coating amount is applied too much, a uniform film can be formed on the brush to improve the texture, but since the space between the brush is prevented from being secured most of the space there is a disadvantage in reducing the air permeability.

These results, while the artificial leather is manufactured by sequentially performing the softening agent attaching step (S1), brush forming step (S2), back surface strengthening step (S3) and film forming step (S4) of the present invention, the film forming step ( Through various examples and comparative examples carried out by changing only the application amount of the water-soluble PU resin solution in S4) it was possible to confirm the difference in breathability and texture, the results are shown in the table below.

At this time, the breathability is taken from each artificial leather manufactured in each Example and Comparative Example by cutting the 18cm X 18cm samples, and the test piece is attached to one end of the cylinder using the FRAZIER, the inclined pressure gauge The pressure of the water column 12.7mmH ₂ O is to be shown, and then the amount of air passing through the test piece is obtained from the pressure indicated by the vertical pressure gauge and the type of air OLIFICE used according to the table attached to the tester. did. In addition, the texture of each sample was subjected to sensory evaluation by 20 adults, and then compared with the texture of the artificial leather manufactured by the dry method in the conventional manufacturing method, the results are evaluated in three levels of good, normal, and poor. The decision was made by a number of opinions.

division Coating amount (g / ㎡) Breathability (ml / cm 2 / sec) Texture Example 1 55 0.20 Good Example 2 50 0.26 usually Example 3 60 0.12 Good Comparative Example 1 45 0.31 Bad Comparative Example 2 65 0.07 Good Natural leather - 0.10 -

In Table 1, Examples 1 to 3 sequentially perform the above-described manufacturing method of the present invention, that is, a softening agent attaching step (S1), a brush forming step (S2), a back surface strengthening step (S3), and a film forming step (S4). By manufacturing artificial leather, only the coating amount of the water-soluble PU resin solution in the film forming step (S4) was changed within the range of 50 ~ 60g / ㎡, Comparative Examples 1 and 2 in the same manner as in Examples 1 to 3 It is prepared, but the coating amount of the water-soluble PU resin solution in the film forming process (S4) is changed out of the range of 50 ~ 60g / ㎡.

As can be seen from Table 1, in Examples 1 to 3 produced by the application amount of 50g / ㎡, 55g / ㎡, 60g / ㎡, it was shown that the breathability is better than natural leather and the texture is also conventional Although it was evaluated as being more than normal compared to leather, Comparative Example 1 prepared with a coating amount of 45g / ㎡ showed better breathability than natural leather, but the coating amount is too small, the texture is poor compared to conventional artificial leather In Comparative Example 2 prepared at an application amount of 60 g / m 2, the coating amount was too high, indicating that the air permeability was poor compared to natural leather, and the texture was evaluated to be good.

From the results of these examples and comparative examples, when the coating amount of the water-soluble PU resin solution decreases in the film forming step (S4), the space between the raising is ensured, the air permeability is good, but the texture of the coating is bad, and on the contrary, when the coating amount is high, the texture is good. It was found that the space between the raising is less secured and the breathability is worse. Among them, the artificial leather manufactured at the coating amount in the range of 50 to 60 g / ㎡ in Examples 1 to 3 has a breathable and good texture can be maintained It was confirmed that the artificial leather, which is suitable as an artificial leather produced at a coating amount outside the range of 50 to 60 g / m 2, has little or no breathability and cannot achieve the object of the present invention.

Again, referring to FIG. 1 and FIG. 2 (d), the film forming step S4 is a primary coating step of applying an 80-84% coating amount with the applicator 41 among the total coating amount of the water-soluble PU resin solution. (S4-1), and after the primary coating step (S4-1) to dry (130 ℃ ~ 160 ℃) to uniformly pressurized by the heat press roller 42 to smooth the uniformity of the primary coated surface It is preferable to consist of a process (S4-2) and the secondary coating process (D4-3) which apply | coats the remaining 16-20% water-soluble PU resin solution with the applicator 43 after the said smoothing process (S4-2). .

In this way, by increasing the coating amount in the first coating step rather than the second coating step (S4-1), the resin solution can sufficiently penetrate between the raising and strengthening the bonding force between the raising and the coating, and the second coating step (S4-). By applying the remaining coating amount in 3), it is possible to form a uniform film on the brushed surface, and after the first coating process, a second coating process is performed on the smoothed surface through the smoothing process (S4-2). By forming the surface texture of the artificial leather can be smoothly implemented.

In addition, the present invention further includes a pattern forming step (S5), a painting step (S6) and a surface strengthening step (S7). The pattern forming step (S5) is to form a pattern by embossing the film on the surface of the fabric (W) after the film forming step (S4), for example, by forming a leather pattern on the mold to the electric heater The shape of the leather can be expressed by pressing the fabric with a rod, and the surface quality is determined by the manufacturing method of the mold, the heat embossing temperature, and the processing speed.

In addition, the painting step (S6), after the pattern forming step (S5) is to give a color by spraying a thin film of a water-soluble resin solution diluted with a pigment on the surface of the coating, the surface strengthening step (S7) is the painting step (S6) After spraying a thin layer of the top protective resin (polyurethane resin) for heat resistance, cold resistance, and abrasion resistance to the film surface to increase the durability of the pattern formed on the film surface and to form a protective film to ensure a good quality.

Therefore, the surface texture and quality of the artificial leather manufactured by the manufacturing method of the present invention through the pattern forming process (S5), the painting process (S6) and the surface strengthening process (S7) as described above can be further improved.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the present invention and not to be construed as limiting the scope of the present invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (4)

A brush-forming step of raising the surface tissue of the fabric to a brush- raising machine to make them fluff;
A back strengthening process of reinforcing a back structure of the fabric by coating a flame-retardant coating on the back of the fabric; And
A method of manufacturing an artificial leather having air permeability, comprising a film forming step of forming a film on the surface of the fabric by applying a water-soluble PU resin solution of 50 ~ 60g / ㎡ on the surface of the fabric formed on the surface of the fabric. The method of claim 1, wherein the film forming process,
A primary coating step of applying 80 to 84% of the total coating amount of the water-soluble PU resin solution,
A smoothing step of making the surface smoothness even by drying after the first coating step and heating and pressing the surface of the fabric;
A method of manufacturing artificial leather having air permeability, comprising a second coating step of applying the remaining 16-20% water-soluble PU resin solution after the smoothing step. The method of claim 1 or 2, wherein the softener attaching step of imparting flexibility to the surface of the fabric by impregnating the fabric and attaching the softener to a storage tank containing the softening agent solution diluted with water prior to the brushing step is carried out. Method for producing artificial leather having a breathable, characterized in that it further comprises. The pattern forming process according to claim 3, further comprising: forming a pattern by embossing the film on the surface of the fabric after the film forming process;
A painting process of imparting color by spraying the resin solution diluted with the pigment on the surface of the coating after the pattern forming process;
And a surface strengthening step of spraying a top protect resin on the surface of the coating after the painting process.

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