KR900005057B1 - Air-breathing polyurethane leather and it's production of process and machanism - Google Patents

Abstract

The air-breathing, moisture-permeable polyurethane synthetic leather is prepd. by: forming non-fixed wave type porous coating layer (11), which is mutually regularly bound with the base fabrics (10), by coating the coating mixt. compsn, on the raised surface (10a) of the base woven fibric (10); forming an airbreathing moisture-permeable grain type thin layer by an embosstranscription moulding process of the surface of the coating layer (11) using by a releasing paper (12) . The coating mixt. compsn. comprises polyurethane thermoplastic resin (11a), thermosetting resin (11b), solvent, crosslinking agent, accelerating agent, pigment and other additives.

Description

Air-Breating Polyurethane Leather and It's Production Know-how of Process and Mechanism

1 is a schematic view of the manufacturing apparatus of the present invention.

Figure 2 is an enlarged view of the main part of Figure 1 of the present invention.

Figure 3a, b is a schematic diagram showing a conventional manufacturing apparatus of polyurethane synthetic leather.

4 is an enlarged cross-sectional view of the inventive leather synthetic leather.

5a, b, c is an enlarged cross-sectional view of a conventional polyurethane synthetic leather.

* Explanation of symbols for main parts of the drawings

1: drying chamber 2: forming chamber (high temperature housing)

3: coating part 3a: hopper

4: heating drum 5: close press roller

6: endless belt 6a: auxiliary press roller

6b: belt 7: finish thread

10: foundation forge 10a: raising

11: coating layer 11a: polyurethane thermoplastic resin

11b: polyurethane thermosetting resin 12: release paper

The present invention relates to artificial leather, and in particular, a one-time application of a liquid mixed resin obtained by mixing a solvent, a crosslinking agent, an accelerator, a pigment, and other additives with a thermoplastic resin, which is a polyurethane-based resin, and a thermosetting resin, is applied to the brushed layer of the base cloth for each use. · Atypical waveform porous layer is formed by a series of simple single drying process to dry and then release release paper on the dried surface and surface treatment by surface transfer molding method such as heating and pressing to improve air permeability and moisture permeability. Air-Breathing Polyurethane Leather and It's Production Know-how of Process and Mechanism.

Conventionally, various kinds of artificial leather are known according to the composition, structure, manufacturing method and device, and according to the synthetic resin which is a composition, it can be classified into polyurethane resin, PVC resin and others. Seed resins are being refluxed because cold resistance, appearance, and touch are not similar to natural leather, whereas polyurethane resins are widely used in a variety of ways, and are mainly used in similar leathers.

In addition, artificial leather is divided into SUEDE TYPE without coating layer and GRAIN TYPE with coating layer.These are divided into artificial leather and synthetic leather. Artificial leather is composed of urethane resin component and fiber entangled in three directions rather than flat and connected in all directions. It has a myriad of atypical waveform porous materials, which is similar in structure to natural leather, so it has good ventilation and moisture permeability while producing cost. There are high and uneconomical disadvantages, and synthetic leather is a layered combination of a urethane resin layer and a fiber layer wrapped in a plane, which is economical due to the low production cost, but has a problem in that it lacks similarities in many respects with natural leather.

On the other hand, when the manufacturing method of the conventional artificial leather and synthetic leather as described above can be classified into dry process and wet process, the dry process, which was invented and widely spread in Germany, coated a liquid resin on a release surface, It is obtained by drying and applying the adhesive layer to the coating layer, and then joining and bonding the fibers such as the fabric and the nonwoven fabric, which are the basic substrates, and finally drying them, which is obtained by repeatedly coating the resin and the solvent on the release surface. At the same time, a large amount of coating is difficult and at the same time, there are inconveniences in the process of undergoing the overlapping coating process of the coating layer and the overlapping coating process of the adhesive, and the coating layer is formed of the sealing film layer.

In addition, the wet process of the concept symmetrical to the dry process is invented in the United States to dilute and disperse coagulated urethane resin in a dimethyl boehmide (DMF) solution to apply (coating) or impregnation to the fiber and then solidify in water In the process of coagulation in water, dimethylpymamide (DMF) is dissolved in water, and its space is formed into a fine porous form, which allows for breathable permeability. Formation was not possible, and the production costs were exposed to uneconomical problems, which cost 5-6 times that of dry.

In addition, recently, the manufacturing process that combines wet and dry, which is the final coating treatment, has been developed by the fact that it is difficult to form a grain film on the surface by pure wet method recently, but the microporous layer reinforces the texture, flexibility, resilience, etc. Other than the dry product was no different.

Looking at a specific example of the grain type synthetic leather manufacturing apparatus and manufacturing method according to the conventional dry process associated with the present invention of the prior art as described above are as follows.

Figure 3a is a manufacturing apparatus of a general process (b) is a resin coating on the release paper in view of the configuration of all of them into a manufacturing apparatus of a product that requires relatively strong physical properties (shoes, sheets) Dryers are installed between the coating sections, which increases installation, work space, and power consumption. Meanwhile, in the manufacturing method using the manufacturing apparatuses, a coating composition is formed by distinguishing a polyurethane thermoplastic resin and a thermosetting resin. In the first coating part, the thermoplastic resin is first coated on the release paper and dried in the first dryer. [In FIG. 3b, the thermoplastic resin is coated again in the second coating part in the second coating part on the first coating and dried in the second dryer.] A separate thermosetting resin (adhesive) is coated on the thermoplastic film layer (epidermal layer) which is dry-molded by the primary coating to compress the base paper before drying. After drying in the second dryer to mature to prepare a polyurethane synthetic leather, the coating composition is to separate the thermoplastic resin (film layer) and the thermosetting resin (adhesive layer) to each of the formulation composition and these as a separate coating process over a number of The process has to be processed and at the same time, various types of adhesion defects are caused by coating amount, solvent content raising condition, press condition, etc. when crimping the base paper, resulting in decreased productivity and control of arbitrary physical properties (soft and strong). Not only was it impossible, but the coating and drying were repeated, which caused a lot of power and operating costs as well as installation and work space, which exposed the unreasonable point of mass production system such as higher production cost.

On the other hand, the polyurethane leather produced by the above process is a coating layer as shown in Figs. 5a, b is composed of 2-3 layers of the skin layer and the adhesive layer to form a plastic-like feel and appearance and the thickness is about 20-40 microns Thinning caused a problem of being easily damaged by abrasion and hydrolysis phenomenon. Moreover, the adhesive layer is composed of a single layer of thermosetting resin, so that it is weakly complementary with the epidermal layer (film) and has a weak physical property and a hard property. There were well broken defects exposed.

In addition, in the construction method of the polyurethane synthetic leather, after pressing the adhesive layer coating, the base fabric is press-bonded before drying, and as illustrated in FIG. 5a, the defect rate of the adhesive layer is impregnated into the base fabric or adhered to only the brushed surface, resulting in the lifting phenomenon. Production problems were not too small.

The present invention has been made in view of the deficiencies and problems in the polyurethane synthetic leather and its manufacturing method and manufacturing apparatus according to the prior art in order to mass-produce high-quality products with excellent ventilation and permeability and uniformity in a single dry type. This will be described in detail with reference to the accompanying drawings as follows.

In the manufacturing apparatus of the present invention, as shown in FIG. 1 and FIG. 2, a drying chamber 1 and a forming chamber (2: high-temperature housing) are installed, and a normal coating is provided on the front side (base foam supply part) of the drying chamber 1. The part 3 may be configured, but the coating part 3 may be provided with a plurality of hoppers 3a as needed, and the molding chamber 2 may be supplied with release paper 12 and a heating drum therein. (4: HEATING DRUM) and the press roll (5: PRESS ROLL), the auxiliary press roll (6a) and the belt (6b) and the bells (6: ENDLESS BELT) and finishing press roll (7) : FINISH PRESS ROLL) was installed.

In addition, the base material that is injected into the coating unit 3, that is, the coating composition is made of a conventional polyurethane thermoplastic resin (11a) and thermosetting resin (11b) as a main raw material solution, crosslinked product, accelerator, pigment, other additives ( Add as needed) into a mixed form in which the appropriate amounts are blended as shown in the diagram below.

TABLE 1

(PT = PART)

The manufacturing process according to the present invention manufacturing apparatus as described above in detail with reference to FIGS. 1 and 2 as follows.

The base paper 10 is supplied to the coating unit 3, the drying chamber 1, and the molding chamber 2 so that the heating drum 4, the close press roller 5, and the endless belt 6 of the molding chamber 2 are provided. ), Through the finishing press roll (7) and the release paper 12 is transferred to the molding chamber 2 to pass through the same path as the base paper (10). In this case, the coating composition blended in the coating part 3 is coated on the brushed surface 10a of the base paper 10. If necessary, the coating composition is thickened by using a plurality of hoppers 3a. -Three coatings may be performed sequentially.

As described above, the mixed coating composition of the thermoplastic resin 11a and the thermosetting resin 11b is directly coated on the brushed surface 10a surface of the base paper 10 so that the raised layer 10a fibers and the coating composition are entangled and have an amorphous waveform porous coating layer. (11) is formed and dried in a drying chamber (2) which is transferred at a suitable speed under a suitable temperature. Then, when the base paper 10 subjected to the coating process is transferred to the molding chamber 2, the release paper for surface transfer molding which is simultaneously transferred to the molding chamber 2 (12: embossed surface treatment as necessary) The embossed transfer molding process is carried out so that the surface of the coating layer 11 is formed into a grain type. The embossing transfer molding process is always heated to a proper temperature in a heating drum 4 in the molding chamber 2. In the state (temperature above the stable temperature of the molecule) to pressurize the primary contact press roll (5) and press the continuous pressing operation again with the pressing endless belt (6) installed so that a plurality of auxiliary press roll (6a) interlocked Tertiary pressing is carried out in the finishing press roll (7). Therefore, the press-belt molding of the surface is completed to the same level as the injection molding, because the continuous and continuous pressing is performed in the endless belt 6, and the surface of the grain type is perfectly expressed. After the press-transfer molding process as described above, the release paper 12 is separated and the base paper 10 having the grain type coating layer 11 is finally aged by a conventional method, and thus, polyurethane synthetic leather having excellent ventilation and moisture permeability. Will be manufactured.

On the other hand, the polyurethane synthetic leather according to the manufacturing apparatus and manufacturing method of the present invention as described above, as shown in Figure 4, the thermoplastic resin 11a and the thermosetting resin 11b of the polyurethane is uniformly dispersed and mixed surface The grain-type coating layer 11 of amorphous wave form is formed together with the brushed 10a fibers of the base paper 10, which is expressed until, to have a breathable and moisture-permeable structure such as natural leather.

Hereinafter, the operation and effects of the present invention as described above will be described in detail with reference to the accompanying drawings.

The coating composition is coated on the brushed surface 10a of the base paper 10 as needed in an appropriate amount to form a coating layer 11, and the embossed surface-treated release paper 12 is brought into contact with the surface of the grain type by press-transforming. At the same time, the coating layer 11 is ideally coated and adhered to the bottom surface of the brushed layer due to the suicide and viscosity of the coating composition. It is possible not only to arbitrarily control the feel and feel (soft and strong), but also to completely eliminate the impregnation or lifting phenomenon caused by the conventional adhesive coating layer.

In addition, as illustrated in FIG. 4, the coating layer 11 is formed of a thick single layer, and thus has excellent durability and impact resistance as compared with the conventional 2-3 layers (adhesive layer, film layer). And not only good solvent resistance but also amorphous fiber with the brushed 10a fibers of the base paper 10, in which the mixed coating composition of the thermoplastic resin 11a and the thermosetting resin 11b is uniformly dispersed and mixed to the surface. By forming a layer, it is excellent in breathability and moisture permeability like natural leather, and also greatly improves the touch and flexibility, so that the defects well broken by the conventional adhesive layer formed of the thermosetting resin can be completely eliminated.

In addition, the present invention is to be able to significantly improve the production efficiency by significantly reducing the production cost, such as work space, labor costs and power costs by making the coating and drying process in a single linked process compared to the conventional overlapping process.

Compared with the conventional physical properties of the polyurethane synthetic leather of the present invention as described above is as follows.

TABLE 2

As described above, the present invention simplifies the installation chamber and the drying chamber connected to the coating unit by installing the answering belt and the press roller around the heating drum as a series of single dry manufacturing apparatus to reduce the installation space and operation cost and achieve mass production system. Phosphorus effect can be achieved, and the coating layer is uniformly bonded by the post-treatment process of embossed transfer molding method using a release paper after forming a coating layer of an atypical waveform porous layer by directly coating and drying the base paper directly in the manufacturing method. It is a very excellent invention that can not only obtain the grain type of high-grade synthetic leather, but also satisfy all the points required for synthetic leather including breathability and moisture permeability in physical properties.

Claims (6)

Polyurethane thermoplastic resin (11a) and thermosetting resin (11b) and a mixed coating composition containing a solvent, a crosslinking agent, an accelerator, a pigment, and other additives in an appropriate ratio are coated on the brushed surface (10a) side of the base paper (10) 10) Grain type which constitutes the coating layer 11 of the atypical waveform porous layer that is complementarily and uniformly bonded to the fiber, and the surface of the coating layer 11 is embossed by the embossed transfer molding process by the release paper 12. Leather of breathable and moisture-permeable polyurethane, characterized by forming a film of Polyurethane thermoplastic resin (11a) and thermosetting resin (11b) and a mixed coating composition containing a solution, a crosslinked product, a promoter, a pigment, and other additives in an appropriate ratio are directly coated on the brushed surface (10a) side of the base paper (10). And then dried to form an atypical waveform porous coating layer 11 in which fibers and coating compositions are uniformly dispersed and combined, and the release paper 12 is brought into contact with its surface to form a heating drum (2). 4) Through the embossing transfer molding process by the close press roll (5), the endless belt (6), the finish press roll (7), etc., the tip of the brush (10a) is expressed on the surface and evenly coated to be similar to the natural leather. A method for producing a synthetic leather of breathable and moisture-permeable polyurethane, characterized by having physical and grain type appearance. An endless belt composed of a contact press roll 5, a plurality of auxiliary press rolls 6a, and a belt 6b around the coating layer drying chamber 1 and the hutting drum 4 having the conventional coating part 3 as a whole. (6), the forming chamber (2) equipped with the finishing press roll (7) and the like to form a continuous connection of the sintering so that the coating composition is directly coated and dried on the base paper (10) M by the release paper (12) An apparatus for manufacturing a synthetic leather of breathable and moisture-permeable polyurethane, characterized in that the boss transfer molding enables the surface of the coating layer to be manufactured in a grain type. According to claim 1, wherein the ratio of the coating composition to be coated and dried on the brushed surface (10a) surface of the base paper (10) [Polyurethane thermoplastic resin: polyurethane thermosetting resin: solvent: crosslinking agent: accelerator: pigment: other additives (necessary = 70-80 PT: 20-30 PT: 30-40 PT: 8-12 PT: 4-6 PT: 10-15 PT: Trace amount] and equally mixed with the brushed (10a) fiber Leather of the breathable and moisture-permeable polyurethane composite, characterized in that the coating layer 11 of the grain type to form a dispersive bond. The method according to claim 2, wherein the mixed coating composition is coated with a plurality of hoppers 3a formed on the coating unit 11 as needed, followed by drying the embossed transfer molding process using the release paper 12 whose surface is embossed. A process for producing a breathable, moisture-permeable polyurethane synthetic leather, characterized in that the treatment. 4. The heating drum (4) according to claim 3, wherein the release paper (12) for surface embossing transfer molding is fed into the forming chamber (2) to which the base paper (10) coated and dried in the drying chamber (1) is fed. The presser belt 6 consisting of a close press roll 5, a plurality of auxiliary press rolls 6a and a belt 6b, and a finishing press roll 7 are sequentially connected to the heating drum 4, respectively. A device for manufacturing a synthetic leather of breathable and moisture-permeable polyurethane, characterized in that the embossed transfer molding is carried out while the release paper 12 is in contact with the coated and dried coating layer 11.

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