TPU powder-containing polyurethane foam composition and method for manufacturing insole using same

Abstract

The present invention relates to a TPU powder-containing polyurethane foam composition and a method for manufacturing a shoe pad using the same, and provides a TPU powder-containing polyurethane foam composition and a method for manufacturing a shoe pad using the same, the TPU powder-containing polyurethane foam composition and the method for manufacturing a shoe pad using the same, the TPU powder-containing polyurethane foam composition and the method for manufacturing a shoe pad using the same, since the composition contains a predetermined amount of thermoplastic polyurethane (TPU) powder having an average particle size of 50 [mu] m to 300 [mu] m, when a polyurethane foam sheet formed from the composition is placed in a mold and processed into an insole shape by heat press, as the time on a step of molding in the mold is reduced to a level of half, the thickness of the insole is increased, and the thickness of the insole is increased. And the high-price energy cost can be reduced while the production rate of the product is greatly improved.

Description

Technical Field

[0001] The present invention relates to a polyurethane foam composition containing thermoplastic polyurethane (TPU) powder and a method for producing an insole using the same. More specifically, the present invention relates to a polyurethane foam composition containing TPU powder and a method for producing an insole using the same. The composition comprises thermoplastic polyurethane (TPU) powder, and thus, the composition comprises an environmentally friendly water-foaming polyurethane foam composition. This composition can reduce by half the time required for the heat press process of processing a polyurethane foam sheet formed from the TPU composition into an insole or foam packaging for a shoe upper. Background Art

[0002] Typically, shoes like leather shoes, sneakers, and hiking boots consist of an upper (the outer leather part) that creates the shoe's appearance, a sole (the outer sole) that contacts the ground, a midsole (the inner sole) located above the sole, and an insole (the inner sole) that contacts the foot. The insole is located on the inner bottom surface of the shoe and is designed to mitigate the impact of the ground on the foot during walking, improving comfort and hygiene.

[0003] Insoles, as described above, have been given a variety of functions based on research findings that foot health is a crucial factor in the human body. For example, insoles are being developed with ergonomically designed structures that effectively absorb shock, while materials are being developed to improve sweat absorption, antibacterial properties, and deodorizing properties. Recently, a technology has been proposed that incorporates heating wires into insoles to provide warmth and prevent winter frostbite.

[0004] In addition, as materials widely used for the above-mentioned insoles, polyurethane (PU), ethylene-vinyl acetate (EVA), polyethylene (PE), latex, etc. are foamed and molded into foam sheets. These are usually bonded to fabric woven from natural or artificial fibers using adhesives or hot melt films.

[0005] This bonding process involves applying a liquid adhesive to the material being bonded, then drying it to evaporate the solvent or water, thus bonding it to the fabric. This has the advantage of reducing process time and labor requirements compared to sewing. However, to minimize costs, a process using thermoplastic hot-melt film instead of liquid adhesive and heat pressing to bond the fabric is more commonly used. As mentioned above, the foam sheet to be bonded to the fabric is usually formed into the shape of an insole by high-temperature heat pressing.

[0006] Regarding the prior art of manufacturing insoles using the foam sheet mentioned above, Korean Patent Publication No. 10-2009-0086791 (Shin Seungwook) relates to an adhesive leather insole using high-density polyurethane foam, characterized in that the following structures are stacked in sequence: a cushioning layer 10, which is attached to the bottom surface of the leather shoe to prevent the foot from slipping, and has excellent impact absorption and resilience, and has a strength of 0.8~1.0 g / cm 3 The high-density polyurethane foam of a density of 10000 is heat-treated, then pressed by cold pressing and sliced ​​into the shape of the insole to be formed; the adhesive layer 20 is coated with polyacrylate, natural rubber or synthetic rubber adhesive, or hot melt adhesive on the surface of the buffer layer 10 attached to the adherend; and the release paper layer 30 protects the adhesive layer 20.

[0007] In addition, Korean Patent No. 10-1569659 (Nike inovate CV) discloses a method for molding a foamed article, comprising the steps of placing a desired amount of thermoplastic polyurethane foam beads in a compression mold in the shape of an article, wherein the thermoplastic polyurethane foam beads have a density of 0.01 g / cm 3 to 0.3g / cm 3 closing the mold; causing the mold to reach a maximum temperature of 130°C to 180°C within a period of 300 seconds to 1,500 seconds; within 30 seconds after reaching the maximum temperature, cooling the mold to a temperature of 5°C to 80°C within a period of 300 seconds to 1,500 seconds; and removing the product.

[0008] In addition, the inventors have developed a method for manufacturing insoles through Korean Patent No. 10-1760577 (Park Hee-dae), not only to improve the cushioning feeling and prevent slipping, but also to maintain excellent sweat absorption or comfort for a long time when worn for a long time. The method is characterized by comprising the following steps: using a hydrophilic polyether polyol to prepare a polyurethane resin; mixing 50% to 95% by weight of the polyurethane resin with 5% to 50% by weight of water, putting the mixed polyurethane resin into a mold for foaming, and then curing it for 40 minutes to 60 minutes to produce a polyurethane foam skin; applying an adhesive between the foamed polyurethane foam and the polyurethane foam skin to bond them together, forming a thickness ratio of the polyurethane foam to the polyurethane foam skin of 2:1, and drawing and bonding them to produce an insole.

[0009] Furthermore, the present invention has investigated the following polyurethane foam composition: This composition is an environmentally friendly polyurethane (PU) foam composition formed by water foaming. Because this composition contains a predetermined amount of thermoplastic polyurethane (TPU) powder having a predetermined particle size, the time required to process a polyurethane foam sheet formed from this composition into a mold and heat press molding it into foam packaging for insoles or shoe uppers can be significantly reduced. Summary of the Invention

[0010] Technical issues The present invention provides a polyurethane foam composition containing TPU powder and a method for producing insoles using the same. The environmentally friendly polyurethane (PU) foam composition, formed by water foaming, contains a predetermined amount of thermoplastic polyurethane (TPU) powder having an average particle size of 50 to 300 μm. When a polyurethane foam sheet formed from the composition is placed in a mold and heat-pressed to form insoles or foam packaging for shoes, the molding process time is reduced by half, thereby significantly improving product productivity and reducing high energy costs.

[0011] Technical Solution The present invention relates to a polyurethane foam composition containing TPU powder and a method for producing insoles using the same. This environmentally friendly polyurethane (PU) foam composition, formed by water foaming, contains a predetermined amount of thermoplastic polyurethane (TPU) powder having an average particle size of 50 to 300 μm. When a polyurethane foam sheet formed from the composition is placed in a mold and processed by heat pressing into insoles or foam packaging for shoes, the molding process time is reduced by half, significantly improving product productivity while reducing high energy costs.

[0012] Technical Effects The polyurethane foam composition containing TPU powder and the method for producing insoles using the same of the present invention are environmentally friendly polyurethane (PU) foam compositions formed by water foaming. Since the composition contains a predetermined amount of thermoplastic polyurethane (TPU) powder having an average particle size of 50 μm to 300 μm, when a polyurethane foam sheet formed from the composition is placed in a mold and processed by heat pressing into insoles or foam packaging for shoes, the time required for the molding process in the mold is reduced by half, significantly improving product productivity and reducing high energy costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 FIG1 is a process flow chart showing a method for manufacturing an insole using the polyurethane foam composition containing TPU powder according to the present invention.

[0014] Best Mode for Carrying Out the Invention The polyurethane foam composition containing TPU powder according to the present invention is composed of polyol, isocyanate, and chain extender as raw materials, and water as a blowing agent. The polyurethane foam composition is characterized in that, based on the total weight of the polyurethane foam composition, the polyurethane foam composition contains thermoplastic polyurethane (TPU) powder having an average particle size of 50 μm to 300 μm at a ratio of 5% to 30% by weight.

[0015] The method for manufacturing an insole using the polyurethane foam composition is characterized in that, based on the total weight of the polyurethane foam composition, the polyurethane foam composition contains 5% by weight to 30% by weight of thermoplastic polyurethane (TPU) powder with an average particle size of 50 μm to 300 μm, and the polyurethane foam composition is heated by the heat press. The insole manufacturing method includes the following steps: reacting a polyurethane foam composition composed of polyol, isocyanate and chain extender as raw materials and water as a foaming agent to produce a polyurethane block foam (S100); cutting the polyurethane block foam into a desired thickness to form a polyurethane foam sheet (S200); laminating the polyurethane foam sheet cut into the desired thickness with a fabric (S300); placing the polyurethane foam sheet laminating with the fabric into a mold, and subjecting the polyurethane foam sheet to a temperature of 150°C to 200°C and a pressure of 40 kgf / cm 2 ~60kgf / cm 2 The insoles or the uppers are formed by heat pressing for 80 to 120 seconds to be processed into foam packaging for insoles or shoe uppers (S400); and the processed insoles or the uppers are cut into foam packaging for insoles or shoe uppers (S500).

[0016] According to a preferred embodiment of the present invention, the thermoplastic polyurethane (TPU) powder can be used alone or in combination with one selected from virgin thermoplastic polyurethane and recycled thermoplastic polyurethane. The adhesive used in the step (S300) of laminating the polyurethane foam sheet with the fabric is composed of a resin composition selected from thermoplastic polyurethane (TPU) or ethylene vinyl acetate (EVA). In this case, the polyurethane foam sheet formed by reacting the polyurethane foam composition containing TPU powder has a hardness of 8-40 (ASKER C-Type) and a density of 0.05 g / cm 3 ~0.2g / cm 3 Within the range.

[0017] The insole manufactured by the above manufacturing method is formed to have a hardness (ASKER C-Type) of 8 to 40 and a density of 0.05 g / cm 3 ~0.2g / cm 3 The structure is a composite structure of polyurethane foam sheet and fabric within the range of . DETAILED DESCRIPTION

[0018] Hereinafter, the polyurethane foam composition containing TPU powder and the method for manufacturing an insole using the same according to the present invention will be described with reference to the accompanying drawings. However, this is only schematically shown to enable a person with ordinary knowledge in the technical field to which the present invention belongs to easily implement the present invention, and therefore does not mean that the technical concept and scope of the present invention are limited.

[0019] Typically, polyurethane resins are produced by reacting isocyanate (-NCO) and hydroxyl (-OH) groups in a polymer to form urethane bonds. Raw materials include polyols, isocyanates, and chain extenders. By adjusting the ratio of the soft and hard segments that make up the polyurethane, a variety of molecular designs are possible, ranging from elastic products like rubber to hard products like plastic.

[0020] This polyurethane resin is characterized by its excellent film strength and adhesive strength, enabling the production of thinner coating films. Furthermore, the coating film's high elasticity allows for the production of soft-touch porous films or sheets, imparting moisture and air permeability while also providing excellent cold resistance. Furthermore, because it can be processed without the use of plasticizers, the processability issues associated with plasticizers are minimized.

[0021] Furthermore, polyols, active hydrogen compounds used to react with isocyanates to produce polyurethanes, refer to compounds with two or more active hydrogen groups, such as hydroxyl, carboxyl, and amine groups, in their molecules. Various types are used, depending on their molecular structure, molecular weight, functionality, and OH value, which directly influence the physical properties of the polyurethane.

[0022] For example, polyurethanes made from polyester polyols not only have higher tensile strength, hardness, and elongation than polyurethanes made from polyether polyols, but also exhibit superior flame retardancy, superior chemical and chemical resistance, strong oxidation resistance, and excellent adhesion to various fabrics woven from polyester and nylon. However, unlike polyether polyols, polyester polyols are susceptible to hydrolysis and therefore have the disadvantage of poor water resistance. However, polyurethanes made from polyether polyols have excellent elasticity, can be used even in high-temperature and high-humidity environments, and exhibit excellent resistance to acids and alkalis. Therefore, they are preferably used alone or in combination depending on the application.

[0023] In the preparation of polyurethane (PU) resin, if polyether prepared by polymerization of ethylene oxide is mixed with diisocyanate, polyurethane is produced. Polyurethane is a mixed amide-ester produced when alcohol groups react with isocyanate. If triol is used instead of diol, a cross-linking reaction occurs to produce thermosetting polyurethane.

[0024] Accordingly, the polyurethane foam composition containing TPU powder according to the present invention is composed of polyol, isocyanate, and chain extender as raw materials, and water as a blowing agent. It is characterized in that the polyurethane foam composition contains thermoplastic polyurethane (TPU) powder with an average particle size of 50 μm to 300 μm at a ratio of 5% to 30% by weight, based on the total weight of the polyurethane foam composition.

[0025] In the present invention, the polyurethane foam composition includes 0.1 wt% to 2 wt% of water as a blowing agent based on the total weight of the polyurethane foam composition, thereby producing a polyurethane foam having a hardness (ASKER C-TYPE) of 8 to 40 and a density of 0.05 g / cm 3 ~0.2g / cm 3 For foam molded articles (for example, insoles and foam molded articles for shoe uppers) within the range of 1:1 to 2:1, water as a blowing agent may be mixed with the polyol component in advance or may be mixed with the polyol component at the same time as the isocyanate component.

[0026] Taking into account processability and environmental friendliness, the foaming agent includes a predetermined amount of water, a low-carbon source, so that a polyurethane foam molded body of a desired density can be produced while minimizing carbon emissions (water reacts with an isocyanate compound to produce carbon dioxide gas). The present invention studies methods that utilize existing commonly used foaming agents such as carbon dioxide, fluorinated carbons (chlorofluorocarbons, etc.), hydrocarbons (pentane and cyclopentane, etc.), fluorinated hydrocarbons, or methods of pre-dispersing air or nitrogen in the polyol component using an aerosol device. It is believed that these methods not only have poor processability, but are also not preferred due to factors such as harmful effects on the environment such as carbon emissions and high energy costs.

[0027] The present invention, based on extensive experimental data, demonstrates that a polyurethane foam composition containing 5% to 30% by weight of thermoplastic polyurethane (TPU) powder having an average particle size of 50 to 300 μm, based on the total weight of the polyurethane foam composition, significantly shortens molding time. This TPU powder, due to its excellent physical and chemical compatibility with the polyurethane (PU) foam composition, a similar polymer resin, is dispersed at a particle size that optimizes kneading properties. This results in not only moldability using heat presses but also excellent product quality (homogeneity, elasticity, and durability).

[0028] The particle size and content of the thermoplastic polyurethane (TPU) powder can be adjusted within a specific range based on the desired hardness and density of the molded article. However, if the average particle size is less than 50 μm, kneading with the polyurethane foam composition becomes poor, while if the average particle size exceeds 300 μm, dispersibility deteriorates, potentially increasing the defect rate of the molded product. Furthermore, if the content is less than 5% by weight, the effect of reducing the molding time during hot pressing is minimal. If the content exceeds 30% by weight, the process conditions for achieving a uniform hardness are restricted, making it difficult to produce a foam molded article with the desired elasticity (cushioning properties).

[0029] Thermoplastic polyurethane (TPU) is a typical (AB)n copolymer. Due to its repeating structure of hard and soft segments, it has unique mechanical and physical properties with regard to thermal behavior and surface characteristics. This results in high toughness, excellent wear resistance, flexibility, and processability. It is widely used as a material for surface coatings and artificial leather, and is particularly noteworthy for being an elastomer that can be plastically processed by heat even without the addition of a separate plasticizer.

[0030] In order to confirm the exemplary properties of the polyurethane foam composition of the present invention, within the range of hardness and density required by the present invention, the polyurethane foam composition was subjected to the same conditions as conventional hot pressing (temperature 150°C to 200°C and pressure 40 kgf / cm 2 ~60kgf / cm 2) were prepared under the conditions of 20 wt % of thermoplastic polyurethane (TPU) powder with an average particle size of about 150 μm. The results of multiple physical property tests on them are shown in the following [Table 1].

[0031] [Table 1]

[0032] -Hardness: ASKER C type durometer according to JIS K 7312 As shown in Table 1, it was confirmed that the polyurethane foam molded article produced from the polyurethane foam composition containing TPU powder according to the present invention could achieve overall physical properties such as tear strength, tensile strength, elongation, and shrinkage comparable to those of conventional polyurethane foam molded articles not containing TPU powder, even when the molding time by heat press was shortened to half (60 seconds or less) of the conventional molding time (120 seconds or less). The polyurethane foam molded article had a hardness (ASKER C-Type) of 8 to 40 and a density of 0.05 g / cm 3 ~0.2g / cm 3 Within the range.

[0033] Hereinafter, a method for producing an insole using a polyurethane foam composition containing the TPU powder will be described in detail with reference to the accompanying drawings.

[0034] like Figure 1 As shown, the method for manufacturing an insole using a polyurethane foam composition containing TPU powder according to the present invention is characterized in that it comprises the following steps in sequence: reacting a polyurethane foam composition composed of polyol, isocyanate and chain extender as raw materials and water as a foaming agent to manufacture a polyurethane block foam (S100); cutting the polyurethane block foam into a desired thickness to form a polyurethane foam sheet (S200); compounding the polyurethane foam sheet cut into the desired thickness with a fabric (S300); placing the polyurethane foam sheet compounded with the fabric into a mold, and subjecting the mold to a temperature of 150°C to 200°C and a pressure of 40kgf / cm 2 ~60kgf / cm 2The polyurethane foam composition comprises a thermoplastic polyurethane (TPU) powder having an average particle size of 50 μm to 300 μm at a ratio of 5 wt % to 30 wt % based on the total weight of the polyurethane foam composition, and the heat press molding time is shortened to within 40 seconds to 60 seconds. The molding time can be adjusted according to the type of product.

[0035] First, in the process of reacting the polyurethane foam composition used in the step (S100) of manufacturing the polyurethane block foam, the polyurethane foam composition is composed of polyol, isocyanate, chain extender and water as a blowing agent as raw materials, wherein the polyurethane foam composition includes 0.1% by weight to 2% by weight of water as a blowing agent based on the total weight of the polyurethane foam composition, thereby manufacturing a polyurethane block foam having a hardness (ASKER C-Type) of 8 to 40 and a density of 0.05 g / cm 3 ~0.2g / cm 3 The insole is formed by compounding fabric on a polyurethane foam sheet within the range.

[0036] In the present invention, a predetermined amount of water as a low-carbon source is included in consideration of processability and environmental friendliness, and carbon dioxide gas is generated by reacting with the isocyanate compound to produce a polyurethane block foam having the desired density as described above. However, the water used as the foaming agent may be mixed with the polyol component in advance, or may be mixed with the polyol component at the same time as it is mixed with the isocyanate component.

[0037] After the step (S100) of manufacturing the polyurethane block foam, the step (S200) of cutting the polyurethane block foam into a desired thickness of 1 mm to 10 mm (usually 2 mm, 4 mm, 5 mm, 6 mm, etc.) to form a polyurethane foam sheet is carried out; and the step (S300) of compounding the polyurethane foam sheet cut into the desired thickness with a fabric is carried out. The adhesive used in the step (S300) of compounding the polyurethane foam sheet with the fabric is most preferably a liquid adhesive or a hot melt film composed of a resin composition selected from thermoplastic polyurethane (TPU) or ethylene vinyl acetate (EVA) having excellent affinity with the polyurethane foam sheet.

[0038] The adhesive composed of the thermoplastic polyurethane (TPU) or ethylene vinyl acetate (EVA) has good workability and productivity. Since no solvent is used, it is not only environmentally friendly but also has excellent adhesion. Moreover, due to its soft material properties, it is conducive to ensuring adhesion to various fabrics. In particular, it can maintain strong adhesion with the polyurethane foam sheet for a long time, thereby ensuring excellent durability.

[0039] Then, the polyurethane foam sheet compounded with the fabric is placed in a mold and heated to 150°C to 200°C and a pressure of 40kgf / cm 2 ~60kgf / cm 2 The insole is manufactured by a step (S400) of forming the insole into an insole shape by heat pressing for 80 seconds to 120 seconds; and a step (S500) of cutting the insole into the insole shape. However, the present invention shortens the molding time required in the step (S400) of forming the insole into an insole shape to within 40 seconds to 60 seconds, thereby completing the present invention.

[0040] Extensive experiments have confirmed that the core feature of the five steps (S100-S500) described above is that, in the step (S100) of manufacturing the polyurethane block foam, the polyurethane foam composition includes 5% to 30% by weight of thermoplastic polyurethane (TPU) powder with an average particle size of 50 μm to 300 μm, based on the total weight of the polyurethane foam composition. This significantly shortens the molding time in the step (S400) of forming the insole shape by heat pressing. This not only doubles product productivity, but also reduces high energy costs and carbon emissions.

[0041] Specifically, by including TPU powder in the polyurethane foam composition, the present invention can shorten the molding time for forming the insole to half, even when performing a heat press operation under the same temperature and pressure conditions, thereby achieving the intended purpose and effect of the present invention.

[0042] The thermoplastic polyurethane (TPU) powder not only exhibits excellent chemical compatibility with the polyurethane foam composition, a similar polymer resin, but also exhibits excellent moldability by hot pressing due to its dispersion at a particle size that optimizes kneading properties. However, an average particle size of less than 50 μm degrades kneading properties with the polyurethane foam composition, while an average particle size exceeding 300 μm degrades dispersibility, potentially increasing the defective rate of molded products. Furthermore, for the same reasons as above, the maximum particle size of the particles of the thermoplastic polyurethane powder preferably does not exceed 500 μm.

[0043] The thermoplastic polyurethane (TPU) powder may be one selected from virgin thermoplastic polyurethane and recycled thermoplastic polyurethane (e.g., recycled fiber scrap or discarded air bags that have been crushed) or a combination of the two in a predetermined ratio.

[0044] Finally, the insole manufactured after the step of cutting the insole shape (S500) is usually packaged after the logo is applied. The insole manufactured as described above is formed into a hardness (ASKER C-Type) of 8 to 40 and a density of 0.05 g / cm 3 ~0.2g / cm 3 The structure is a composite structure of polyurethane foam sheet and fabric within the range of .

[0045] Hereinafter, the present invention will be described with reference to a method for producing an insole using the polyurethane foam composition containing TPU powder of the present invention, using preferred embodiments that can be easily implemented by a person having ordinary knowledge in the technical field to which the present invention pertains.

[0046] [Example] The method for producing an insole according to the present invention is a method for producing by mixing and polymerizing polyol, isocyanate, and a chain extender as raw materials and water as a foaming agent, and the method comprises the following five steps.

[0047] In the first step, thermoplastic polyurethane (TPU) powder with an average particle size of 150 μm is added to a polyurethane foam composition and reacted to produce polyurethane slabstock foam. The polyurethane foam composition includes 0.1% to 2% by weight of water as a blowing agent and polyol and isocyanate as raw materials.

[0048] Second step: cutting the polyurethane block foam into 4 mm thickness to form a polyurethane foam sheet.

[0049] The third step: using a thermoplastic polyurethane (TPU) hot melt film to laminate the polyurethane foam sheet cut into a thickness of 4 mm with the polyester fiber fabric.

[0050] Step 4: Place the polyurethane foam sheet compounded with the fiber fabric into a mold and heat it at a temperature of 170°C and a pressure of 50 kgf / cm 2 The left and right heat presses are used to form the insole.

[0051] Step 5: cutting the insole into a desired shape to manufacture the insole.

[0052] [Experimental example] When manufacturing insoles using the methods described in the examples above, experiments were conducted to measure the molding time required to heat-press a polyurethane foam sheet laminated with a fiber fabric into an insole shape, depending on the ratio of TPU powder contained in the polyurethane foam composition. This was compared with the molding time required to mold the same polyurethane foam sheet without TPU powder into an insole shape. The average values ​​of the molding time, moldability, and appearance obtained from multiple evaluations are shown in Table 2 below.

[0053] [Table 2]

[0054] As shown in Table 2, the insoles manufactured according to Examples 1 to 6 exhibited excellent moldability, adhesion between the fiber fabric and the polyurethane foam sheet, and appearance, comparable to the comparative examples. However, when the TPU powder content exceeded 30 wt%, during heat press molding, some of the TPU powder within the polyurethane foam sheet melted, causing overflow at the joint between the fiber fabric and the polyurethane foam sheet. This indicated that the density and hardness of the insole product could become uneven.

[0055] As described above, the present invention provides an environmentally friendly polyurethane (PU) foam composition containing TPU powder of a predetermined particle size at an appropriate ratio. This reduces the time required to heat-press the polyurethane foam sheet to be laminated with fabric by half, thereby significantly improving product productivity while reducing high energy costs.

[0056] Industrial Applicability The polyurethane foam composition containing TPU powder according to the present invention can be replaced, deformed and changed in various forms without departing from the technical concept of the present invention. In particular, it has the advantages of being environmentally friendly, improving productivity and reducing manufacturing costs. It can be used not only in various insoles requiring uniform moldability and durability, but also in foam packaging for shoe uppers (decorations), clothing made of fiber or natural leather and synthetic leather, plastic, etc., bags, sports equipment or daily necessities, industrial products, etc., which require functions such as molding materials, cushioning materials, and fillers for internal use.

[0057] Sequence Directory (Free Text).

Claims

1. A polyurethane foam composition comprising polyol, isocyanate and chain extender as raw materials and water as a blowing agent, characterized in that: The polyurethane foam composition contains 5% to 30% by weight of thermoplastic polyurethane powder having an average particle size of 50 μm to 300 μm based on the total weight of the polyurethane foam composition.

2. The polyurethane foam composition according to claim 1, wherein The thermoplastic polyurethane powder is used alone or in combination and is selected from one of original thermoplastic polyurethane and recycled thermoplastic polyurethane.

3. A polyurethane foam sheet, characterized in that: A polyurethane foam composition containing the thermoplastic polyurethane powder according to any one of claims 1 or 2 is reacted to form a polyurethane foam having a hardness (ASKER C-Type) of 8 to 40 and a density of 0.05 g / cm 3 ~0.2g / cm 3 Within the range.

4. A method for manufacturing an insole, characterized in that: The insole manufacturing method includes, based on the total weight of the polyurethane foam composition, a thermoplastic polyurethane powder having an average particle size of 50 μm to 300 μm at a ratio of 5% to 30% by weight, and shortening the molding time by hot pressing to within 40 seconds to 0 seconds. The manufacturing method of the insole comprises the following steps in sequence: A polyurethane foam composition composed of polyol, isocyanate, and chain extender as raw materials and water as a blowing agent is reacted to produce a polyurethane slabstock foam (S100); Cutting the polyurethane block foam into desired thickness to form a polyurethane foam sheet ( S200 ); Compounding the polyurethane foam sheet cut into the required thickness with fabric (S300); The polyurethane foam sheet compounded with the fabric is placed in a mold and heated at a temperature of 150°C to 200°C and a pressure of 40 kgf / cm 2 ~60kgf / cm 2 The process is performed by hot pressing for 80 to 120 seconds to form the insole shape (S400); The insole is cut into shape (S500).

5. The method for manufacturing an insole according to claim 4, wherein: The thermoplastic polyurethane powder is used alone or in combination and is selected from one of original thermoplastic polyurethane and recycled thermoplastic polyurethane.

6. The method for manufacturing an insole according to claim 4, wherein: The adhesive used in the step (S300) of laminating the polyurethane foam sheet with the fabric is a liquid adhesive or a hot melt film made of a resin composition selected from thermoplastic polyurethane or ethylene vinyl acetate.

7. A shoe insole, characterized in that: The insole is formed by the manufacturing method according to any one of claims 4 to 6 to have a hardness (ASKER C-Type) of 8 to 40 and a density of 0.05 g / cm 3 ~0.2g / cm 3 The structure is a composite structure of a polyurethane foam sheet within a range of 1000mm and a fabric.

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