KR950007185B1 - A polyurethanes synthetic leather, devices and method thereof - Google Patents

Abstract

An air- and moisture-permeable polyurethane synthetic leather is mfd. in a porous structure by a wet process. The appts. includes a means for supplying a base fabric (100), a means (201, 201', 201") for coating a compound material (CF), a coagulation tank (202), a washing means (203) for semi-products, a dehydrating means (4) and a drying means (205). A molded belt (210) flows first over the coagulation tank (202) and then circulates in the water of the coagulation tank. A polyurethane compound material is spread on the surface of the molded belt so as to form a coated layer (200) of the synthetic leather. The base fabric is adhered to the coated layer. The coated layer united with the base fabric is coagulated and formed into a porous layer during its circulation in the water of the coagulation tank.

Description

Breathable Wet-Finished Polyurethane Synthetic Leather, Manufacturing Method and Manufacturing Apparatus

Figure 1 (a) is a schematic diagram showing the production of polyurethane synthetic leather according to the wet process / post-treatment skin processing process according to the prior art.

Figure 1 (b) is a schematic diagram showing the production of polyurethane synthetic leather according to the wet process / dry process mixing process according to the prior art.

Figure 2 is an enlarged cross-sectional view of a polyurethane synthetic leather produced by the wet method / dry method mixing process of the prior art.

3 is a schematic diagram schematically illustrating the preparation of polyurethane synthetic leather according to the improved wet process system (method / apparatus) of the present invention.

4 is an enlarged cross-sectional view of a polyurethane synthetic leather produced by the improved wet process system of the present invention.

* Explanation of symbols for main parts of the drawings

100: basic forge (fiber structure) CF: blended raw materials

200: polyurethane coating layer 300 ': adhesive layer

300: epidermal layer by dry method

IPL: Intermediate product of polyurethane synthetic leather manufactured by wet process of the prior art

SPL: Flat skin-derived polyurethane composites manufactured by the prior art wet process

FPL-P1: Polyurethane Synthetic Leather by Prior Art Suction Treatment / Post Treatment

FPL-P2: Polyurethane Synthetic Leather by Wet / Dry Process Mixing Process of Prior Art

IPL-1: Intermediate product of polyurethane synthetic leather produced by the wet process of the present invention

FPL-1: Polyurethane Synthetic Leather by Wet Process of the Present Invention

201, 201 ′, 201 ″: Coating means 202: Coagulation tank

203: washing means 204: dehydrating means

205: drying means 206: surface treatment means

210: circulating mold belt 211, 211 ': drying means

301: release paper 302: coating means

303: Dryer

The present invention is to manufacture a polyurethane synthetic leather by the wet method, in particular, the entire polyurethane film layer including the skin portion having a pattern such as natural leather manufactured by the wet method in a porous structure molded poly having excellent ventilation and moisture permeability The present invention relates to a urethane synthetic leather, a method for manufacturing the same, and a device for manufacturing the same. In more detail, the belt-shaped casting manufactured by intaglio engraving from the surface pattern of natural leather is introduced and used in the wet process, and the polyurethane blending material, which is a coating layer of synthetic leather, is applied to the circulating mold belt to form a mold belt. The skin layer formed in contact with the skin layer is formed with a natural leather skin pattern, and then the fiber structure, which is the basis of the synthetic leather, is bonded with the film layer applied to the mold belt, and the film layer laminated with the fiber structure while the mold belt is submerged in water. By allowing the whole to be solidified into a porous layer, a polyurethane synthetic leather including a skin layer having a natural leather pattern and having an excellent air permeability as a whole can be manufactured by a wet process in a single process, without additional processing steps for post skin processing. Polyurethane Synthetic Leather Manufacturing Method and Apparatus It is about.

In the production of polyurethane synthetic leather by the wet method of the prior art, a fiber structure (base) based on a compounding material (CF; composite feed) in which a polyurethane resin, a solvent, a crosslinking agent, an accelerator, a pigment, and other additives are mixed. It is prepared by directly coating (coating) or impregnating the coated raw material layer in water, and during the coagulation process, a solvent (mainly dimethylformamide (DMF) is used) is extracted by dissolving in water and occupied by the solvent. The fine pores form the coating layer in a porous form to produce a synthetic leather molded article having breathability. However, since the skin part of the film layer thus produced does not have a pattern of natural leather, it has a drawback that is not suitable for various uses as a synthetic leather.

Therefore, post-treatment, such as an embossing process which forms a pattern in the skin part or another skin layer bonding process by a dry process, was performed. That is, as shown in the attached Figures 1 (a) and 1 (b), in the production of polyurethane synthetic leather by the wet method of the prior art, the basis transported by rolls (not separately added) The coating material 201, 201 'on the forge 100 is directly coated with the compounding material (CF) by appropriate recovery, and then immersed in the coagulation bath 202 to move the water-soluble solvent for the polyurethane resin in the compounding material Elution-substituted (mainly DMF) to solidify the coating layer (polyurethane coating layer) in water, and then the resulting intermediate product (IPL) is washed with water washing means 203 and dewatered through dewatering means 204 and dried means. It is dried through the 205 to form a polyurethane composite product (SPL) bonded to the basic microporous film layer 200, the flat porous film layer 200. Then, in order to form the leather effect pattern on the skin of the coating layer, the coating layer 200 is heated and embossed by the surface treatment means 206 using thermoplastic of a polyurethane resin coated with a fine porous layer. By pressing the surface with a roll or the like to emboss the pattern, a leather-patterned surface-treated polyurethane synthetic leather (FPL-P1) was prepared. On the other hand, as shown in FIG. 1 (b), a method of treating a polyurethane flat product (S PL) having a flat surface in connection with a separate dry process is widely used. Here, the release paper 301 is used. The coating material 302 is used to apply the compound material for the skin layer (CF), and a leather pattern is formed on the surface of the skin layer by a titration means (not shown), and then dried through the dryer 303 and thus formed skin layer 300 ) Is bonded to the coating layer 200 of the polyurethane synthetic product (SPL) of the wet process, in general, after applying the adhesive (300 ') to the coating layer 200 in order to increase the adhesion, the skin layer 300 is bonded and the release paper The final polyurethane synthetic leather (FPL-P2) was prepared through the process of exfoliating (301).

Accordingly, the polyurethane synthetic leather (FPL-P2) manufactured by such a wet / dry mixing process may be formed of the base cloth 100, the polyurethane film layer 200, and the adhesive layer 3 00 'as shown in FIG. And an epidermal layer 300.

However, in the production of polyurethane synthetic leather by the wet method of the prior art as described above, since the compounding material is directly applied to the base paper, a considerable part of the coating technology is accompanied by the constraints of the coating technology depending on the type of the base paper and the compounding material; Since the coated base wrapper is driven under tension and the coated film is solidified by immersion, it causes quality problems due to the dimensional stability, and moreover, if the base wrap is made of a high stretch ratio without the fabric of a separate fabric Processing is not possible; As the separate skin pattern processing is subsequently involved, the overall process becomes complicated, resulting in higher manufacturing costs; During the subsequent process, the embossed roll embossed roll is a porous layer, and although the polyurethane resin is thermoplastic, the thermoplastic resin is insufficient to reproduce the delicate pattern effect of the natural leather. Depending on the degree, the porous layer is damaged, and the air permeability is considerably lowered, and the physical property tends to be lowered due to heat deterioration. In addition, in the method of manufacturing the skin layer by the dry process linkage process commonly used and bonding it to the polyurethane synthetic product of the wet process, the skin layer prepared by the dry process is manufactured and bonded to the polyurethane synthetic product of the wet process Even in the method, the skin layer and the adhesive layer produced by the dry method are in a closed film state, although the appearance and texture of the leather fabric can be imparted to the final synthetic leather, but the air permeability of the porous film layer formed by an expensive wet process is increased. It causes a fatal flaw that prevents the problem of being applied to various applications where breathability is required. Due to this, in recent years, gelatin, protein, etc. have been formulated in the epidermal layer and the adhesive layer to improve the function, but there are still problems such as excessive increase in expenses and insufficient breathability improvement.

The present invention has the drawbacks of the above-mentioned prior art, that is, the wet process / post-treatment epidermal processing process is not a complete wet process, there is a problem in the quality and yield of the product and the wet process / dry process mixing process Invented in consideration of the presence of fatal defects in the overall breathability of the manufactured product, the synthetic leather is introduced by using a separate belt-shaped casting cast in the engraved pattern from the natural leather skin pattern to the engraved wet process Applying the polyurethane compounding material to be the coating layer on the circulating mold belt to form a natural leather skin pattern on the skin layer contacting the mold belt, and then the fiber structure (base cloth) to be the basis of the synthetic leather to the mold belt The film laminated to the coating layer coated on the film, and the film was laminated with the base paper while the mold belt was submerged in water. By coagulation, the entire skin layer is solidified and molded into the porous layer while the epidermal pattern transferred from the mold belt to the coating layer is kept intact during the wet process, so that the skin part of the natural leather pattern is completely ventilated without further processing step for post skin treatment. Polyurethane synthetic leather composed of a polyurethane synthetic leather including a film layer having excellent moisture permeability as a single process wet process, and a polyurethane synthetic leather including a film layer having excellent air permeability as a whole can be manufactured by a wet process method in a single process. To provide a manufacturing method and apparatus and a breathable moisture-permeable polyurethane synthetic leather produced by such a method, described in detail with reference to the accompanying drawings, the present invention.

As shown in FIG. 3, in the method for producing a polyurethane synthetic leather by the wet process of the present invention, a separately produced belt-shaped casting (preferably a silicon mold) in which the pattern is transferred from the skin of the natural leather to the engraving The belt 210 is installed to be circulated from the top of the coagulation bath 202 into the water of the coagulation tank 202 by rollers (not separately numbered), and the polyurethane resin, solvent, crosslinking agent, accelerator, A compound material (CF) mixed with a pigment and other additives is appropriately applied onto the mold belt 210 by coating means 201, 201 ', 201 ", etc., wherein the coating layer is physically coated during each coating process. In order to maximize the porosity and to facilitate the subsequent application, it is preferable to dry the coating layer previously applied by the drying means 211, 211 ', etc., and then carry out the subsequent application. The base material 100, which is supplied by conventional means, is transferred by conventional means by applying a proper recovery of the compounding material (CF) onto the coating layer to transfer the natural leather skin pattern to the skin layer of the compounding material (CF) in contact with the mold belt. ) Is bonded to the coating layer (20) of the compounding material (CF) applied to the mold belt by roll pressing, etc .; while the mold belt 210 is submerged and passed through the water in the coagulation tank 202, The coating layer 200 coalesced with 100) is solidified to produce an intermediate product (I PL-1) having the coating layer 200 solidified and molded into the porous layer while the skin pattern transferred from the mold belt 210 is maintained. The intermediate product (IPL-1) is then rinsed through the washing means 203, dehydrated through the dehydrating means 204 and dried through the drying means 205, as in the wet process of the prior art, and cuticles such as natural leather. Porous coating layer 200 having a pattern is a base fabric It is to produce a polyurethane synthetic leather (FPL-1) bonded to the paper (100).

As mentioned above, the compounding material (CF) forming the coating layer may be divided and superimposed on the circulation mold belt 210 at an appropriate number of times and the appropriate thickness according to the process conditions, and may be dried to an appropriate level after application. This treatment provides the advantage that the solvent in the subsequently applied blending material swells the preceding coating layer to maximize the porosity of the final coating layer. The base paper 100 is pretreated with a solution composed of water and a solvent according to the process conditions as in the conventional wet process. The time that the mold belt 210 passes through the water of the coagulation tank 202 during the water coagulation process is controlled to a time suitable for sufficient coagulation of the coating layer 200 according to the process conditions. The base pouch / coating layer peeled off from the mold belt 210 is solidified while being returned and wound in the coagulation tank 202 while the remaining solvent is rapidly eluted in water as the skin portion of the peeled coating layer is exposed to water.

In the above-described method of manufacturing polyurethane synthetic leather of the present invention, first, the compounding material is not directly applied to the base paper, but is applied on the mold belt so that the viscosity and the amount of application of the compounding material are relatively free and the base paper used is applied onto the mold belt. The type of foundation paper that can be used is almost non-limiting because it is bonded with the coated film layer; Second, since the base fabric bonded to the coating layer of the compounding material is loaded on the mold belt and flooded into the coagulation tank, a large part of the driving and physical tension in the process is transferred to the mold belt, so that the base paper combined with the coating layer during the water solidification process Less stress is applied to facilitate process control and improve product yield and quality stability; Without a post surface treatment step or a separate dry process step, the wet process itself has the advantage that it can be provided with a polyurethane synthetic leather having a skin appearance such as natural leather and a film layer excellent in breathability and moisture permeability.

On the other hand, the present invention, in the manufacturing apparatus of polyurethane synthetic leather by the wet process of the prior art, polyurethane-containing belt-shaped casting 210 having a surface in which the pattern is transferred by engraving from the skin of the natural leather intaglio The raw material CF is directly coated onto the surface of the belt-shaped casting 210 and driven together with the belt-shaped casting 210 while the base paper 100 is bonded to the coated coating layer. By introducing and installing in a manner circulating from the top into the water of the coagulation tank 202, without the additional treatment step for post skin processing, polyurethane synthesis including a skin layer having a natural leather pattern and excellent breathability overall Provided is an apparatus that can produce leather in a single process wet method. In the manufacturing apparatus of the present invention, the circulating mold belt 210 introduced as a new process medium has its surface portion transferred from a natural leather skin pattern to be embossed with a negative skin pattern, so that the modeling property can sufficiently have a leather skin effect. It can be manufactured with various materials that can be applied to the process continuously because it has excellent moldability and peelability, strong solvent resistance and heat resistance, no change in form and quality, and easy removal of water after water extraction. Preferably, the circulating mold belt 210 is made of silicone rubber, and the glass fiber or synthetic fiber structure is incorporated therein to support the physical action in use including tension. Generally, the thickness of the mold belt 210 is about 0.4-0.7 mm, and the width and length thereof are adjusted according to the process conditions and the size of the production line.

The present invention also provides a new breathable moisture-permeable wet finished polyurethane synthetic leather produced by the method and apparatus of the present invention described above. As shown in FIG. 4, the polyurethane synthetic leather provided by the present invention is composed of a porous film layer 200 having a skin portion of a pattern such as natural leather and a base paper 100 bonded thereto, and aeration is overall. Its excellent moisture permeability and excellent leather appearance make it suitable for various applications such as clothing, shoes and furniture.

[Examples]

Various compositions composed of 70-80 parts by weight of polyurethane resin, 13-18 parts by weight of dimethylformamide (solvent), 4-7 parts by weight of commercial crosslinking agent, 2-3 parts by weight of accelerator, and 5-8 parts by weight of pigment and other additives. Polyurethane synthetic leathers were prepared by the above-described method and apparatus of the present invention using the compounding raw materials (CF). In the manufacturing processes, the compounding material (CF) coating on the circulating mold belt 210 was divided into three to four times and overlapped with each other. After each coating before the final coating, a drying treatment was performed. The immersion drive time of the composite in the coagulation bath 202 was adjusted to 15-25 minutes.

As a result of visual inspection of the resulted polyurethane synthetic leathers, the appearance was very similar to that of natural leather, and after the application of water droplets, it was observed that after water had soaked into it and evaporated to dryness within a few minutes, the moisture permeability was also quite significant. It was found to be excellent.

As described above, the present invention solves the various drawbacks of the wet process / post-treatment epidermal processing process and wet process / dry process mixing process of the prior art, without the need for further treatment step after the post skin treatment, It is an excellent invention configured to produce a polyurethane synthetic leather including a skin layer having a natural leather pattern and having an overall excellent moisture permeability by a single process wet method.

Claims (3)

In the manufacture of polyurethane synthetic leather by a wet process, the upper part of the coagulation tank 202 by rollers is formed by a separate belt-shaped casting (mould belt, 210) in which the pattern is transferred intaglio from the natural leather skin pattern. It is introduced to circulate from the coagulation tank 202 into the water, and the polyurethane compound material (CF), which will be a coating layer of synthetic leather, is coated on the mold belt 210 to contact the mold belt. Is formed and then bonded to the coating layer 200 of the compounding material (CF) coated on the mold belt 210, the base paper 100 to be the basis of the synthetic leather, the mold belt 210 is a coagulation tank While the immersion in the water in the inside 202 solidifies the coating layer 200 and coalescing the coating layer 200 and the skin layer transferred from the mold belt 210 to the coating layer 200 is maintained intact during the wet process. 20 0) Before Without further processing step for post skin processing, characterized in that the solidified molding to the porous layer, the porous film layer having a natural leather pattern and excellent breathability as a whole, and the base paper 100 incorporated therewith Method for producing a synthetic synthetic polyurethane leather by a single process wet method. Wet process comprising basic forge supply means, compounding material coating means (201, 201 ', ...), coagulation water tank (202), intermediate product washing means (203), dewatering means (4) and drying means (205) In the apparatus for producing a polyurethane synthetic leather according to the present invention, a belt-shaped casting (molding belt, 210) having a surface of which is embossed from a natural leather skin pattern is engraved, and a polyurethane compounding material (CF) is used for the belt. Solidification from the top of the coagulation bath 202 so that it is applied directly onto the surface of the cast casting 210 and the base paper 100 is bonded to the coated coating layer 200 and is driven together with the belt casting 210. The porous coating layer 200 having a skin portion such as a natural leather pattern and having excellent air permeability as a whole without requiring additional treatment for post skin treatment, which is introduced and installed in a circulating manner in the water tank 202. ) And with it A base opposite the device for producing a polyurethane synthetic leather made of a (100) by a wet method in a single step. Polyurethane synthetic leather made of the method according to claim 1, comprising a porous coating layer 200 having a skin portion such as a natural leather pattern and excellent in breathability as a whole and a base cloth (00) incorporated therein.