Fabric-like reinforcing material for urethane foam molding and method for producing a urethane foam molding body

Abstract

Fabric-like reinforcing material for urethane foam molding, obtained by impregnating part of a surface of a nonwoven fabric with a hot-melt magnetic material and immobilizing the hot-melt magnetic material. wherein the hot-melt magnet material has the composition described below and a softening point of 70 to 100 °C, and The melting peak temperature of the ethylene-vinyl acetate copolymer (A) is 50 to 75 °C: Ethylene-vinyl acetate copolymer (A): 10 to 95% by mass, Wax (B): 0 to 30 percent by mass, Magnetic powder (C): 5 to 70 percent by mass, where the sum of components (A), (B) and (C) is 100% by mass.

Description

Technical area

[0001] The present disclosure relates to fabric-type reinforcing materials for urethane foam molding and methods for producing a urethane foam molded article using the same. State of the art

[0002] A conventional urethane foam molded article used for a cushioning material in a vehicle or the like is integrally molded with a fabric-like reinforcing material such as gauze, cheesecloth, or nonwoven fabric to prevent leakage of the urethane resin during foam molding, thereby preventing abnormal noise caused by contact with a metal spring and protecting the urethane member. In the manufacture of the urethane foam molded article, the fabric-like reinforcing material, which is obtained based on a molding die for the urethane foam molded article by cutting and sewing an original fabric of the fabric-like reinforcing material, is temporarily fixed to the molding die and then integrated by injecting a liquid urethane composition through foam molding.

[0003] DE 69900848 T2 relates to an EMI shielding case for an electronic device, and the fiber sheath material disclosed therein is used to surround metal fibers of a metal mat to stabilize them and reduce the flow of molten metal during thermoforming. Japanese Patent Application Laid-Open No. JP 2015-48544 A discloses a method for temporarily securing the woven reinforcement material to the forming die using a magnetic force between permanent magnets and a hot-melt magnetic material containing a magnetic material. The permanent magnets are embedded at multiple locations in the forming die for the urethane foam molded article. The hot-melt magnetic material is immobilized in such a state that the woven reinforcement material is partially impregnated with the hot-melt magnetic material.The hot-melt magnet material is similar to a hot-melt adhesive that contains magnetic materials, such as ferrite, and thermoplastic resin. Thus, the hot-melt magnet material exhibits magnetism and the property of being solid at normal temperature and becoming liquid upon heating, achieving fluidity. Summary of the inventionProblem to be solved by the invention

[0004] In the case of the method disclosed in Japanese Patent Application Laid-Open No. 2015-48544, since the hot-melt magnetic material is immobilized in the fabric-like reinforcing material in the state where the fabric-like reinforcing material is impregnated with the hot-melt magnetic material, there is an advantage in that positional displacement and peeling of the hot-melt magnetic material hardly occur during transportation of the hot-melt magnetic material and during fixing to the molding die. However, the hot-melt magnetic material immobilized in the fabric-like reinforcing material has low flexibility, so in some cases, it is difficult to temporarily fix the fabric-like reinforcing material to the molding die in a state where the hot-melt magnetic material is arranged along curved surfaces of the molding die.

[0005] The purpose of the present disclosure is to provide a fabric-like reinforcing material for urethane foam molding that has flexibility so that it can bend along the curved surfaces of a molding die and can be easily fixed to the molding die for urethane foam molding, and a method for producing a urethane foam molded article using the same. Means to solve the problem

[0006] This object is achieved by the subject matter of independent claims 1 and 6. Further developments according to the invention are the subject matter of the dependent claims.

[0007] According to one aspect of the present disclosure, a fabric-like reinforcing material for urethane foam molding obtained by impregnating a part of a surface of an organic fiber nonwoven fabric with a hot-melt magnetic material and immobilizing the hot-melt magnetic material is characterized in that the hot-melt magnetic material satisfies the composition described below while having a softening point of 70 to 100°C, and the melting peak temperature of the ethylene-vinyl acetate copolymer (A) is 50 to 75°C: Ethylene-vinyl acetate copolymer (A): 10 to 95 mass percent, Wax (B): 0 to 30 mass percent, Magnetic powder (C): 5 to 70 mass percent, where the sum of (A), (B) and (C) is 100 mass percent.

[0008] According to another aspect of the present disclosure, a method for producing a urethane foam molded article using the fabric-like reinforcing material for urethane foam molding includes a fixing step of fixing the fabric-like reinforcing material for urethane foam molding by magnetic force to a molding surface of a molding die including magnets embedded at some predetermined locations, a urethane foam molding step of injecting urethane resin into the molding die and foaming the urethane resin to mold the urethane resin integrally with the fabric-like reinforcing material for urethane foam molding, and a mold releasing step of removing a urethane foam molded article obtained by foam molding from the molding die. Short description of the drawings Fig.1 is a plan view showing one embodiment of a fabric-like reinforcing material for urethane foam molding of the present disclosure. Fig. 2 is an enlarged cross-sectional view of the embodiment of the fabric-like reinforcing material for urethane foam molding of the present disclosure. Embodiments for carrying out the invention

[0009] The fabric-like reinforcing material for urethane foam molding of the present disclosure is obtained by impregnating a part of a surface of an organic fiber nonwoven fabric with a hot-melt magnetic material containing magnetic powder and immobilizing the hot-melt magnetic material.

[0010] The nonwoven fabric used for the fabric-like reinforcing material for urethane foam molding may be made of organic fibers and may have a weight of 50 to 200 g / m 2The weight of the nonwoven fabric is preferably 80 to 175 g / m 2 . If the weight is less than 50 g / m 2 , the urethane resin injected during urethane foam molding tends to leak, resulting in abnormal noise due to contact between a metal spring and the urethane resin. If the weight exceeds 200 g / m 2, wrinkles often occur during forming. The type and thickness of the organic fiber used for the nonwoven fabric are not particularly limited. For example, a polyester woven fabric such as polyethylene terephthalate and polybutylene terephthalate, a polyolefin fiber such as polyethylene and polypropylene (which may be, for example, homopolymers or random copolymers), a polyamide fiber, and the like can be used. Only one type of organic fiber can be used, and two or more types of organic fibers may be combined. In particular, polyester fiber, polypropylene fiber, polyethylene fiber, low-melting polyester fiber with a melting point of 110 to 160 °C, and bicomponent fibers such as polyester / polyethylene, polyester / low-melting polyester, or polypropylene / polyethylene are preferred.The organic fibers may have a thickness of approximately 5 µm to approximately 30 µm or a fineness of approximately 1 dtex to approximately 33 dtex. The nonwoven fabric is not limited to a single-layer fabric and may be a multi-layer fabric obtained by laminating the nonwoven fabrics.

[0011] The hot-melt magnet material is a hot-melt adhesive containing magnetic powder and a thermoplastic resin. It has the properties of being solid at normal temperature and becoming fluid upon heating, and it has a magnetism capable of attracting a magnet. The hot-melt magnet material contains an ethylene-vinyl acetate copolymer (A) as the thermoplastic resin and magnetic powder (C), and optionally contains wax (B).

[0012] The amount of the ethylene-vinyl acetate copolymer (A) is 10 to 95 mass percent based on 100 mass percent of the sum of (A), (B), and (C), depending on the melting peak temperature and melt flow rate (MFR) of the ethylene-vinyl acetate copolymer (A). The amount of the ethylene-vinyl acetate copolymer (A) is preferably 15 mass percent or more, more preferably 20 mass percent or more, and most preferably 30 mass percent or more. In addition, the amount of the ethylene-vinyl acetate copolymer (A) is preferably 80 mass percent or less, more preferably 70 mass percent or less, and most preferably 60 mass percent or less. When the amount of the ethylene-vinyl acetate copolymer (A) is less than 10 mass percent, the melt viscosity tends to be low, making it difficult for the hot-melt magnet material to achieve sufficient flocculation force.When the amount of ethylene-vinyl acetate copolymer (A) is more than 95 mass percent or more, the melt viscosity of the hot-melt magnetic material is too high, so the discharge performance of the hot-melt magnetic material from an applicator is often poor. Furthermore, since the content of magnetic powder (C) is low, sufficient magnetic performance to attract a magnet cannot be achieved.

[0013] The melting peak temperature of the ethylene-vinyl acetate copolymer (A) is 50 to 75°C, preferably 50 to 70°C, and more preferably 55 to 70°C. If the melting peak temperature is less than 50°C, the heat resistance of the hot-melt magnet material is insufficient. If the melting peak temperature is higher than 75°C, the hot-melt magnet material cannot be bent along curved surfaces of the forming die because the flexibility of the hot-melt magnet material is too low.

[0014] The melt flow index of the ethylene-vinyl acetate copolymer (A) is 0.1 to 2500 g / 10 min, preferably 10 to 2000 g / 10 min, and more preferably 20 to 1500 g / 10 min. The melt flow index is measured based on JIS K7210 and corresponds to a flow rate (g / 10 min) for 10 minutes under the conditions of a temperature of 190 °C and a load of 2.16 kg.

[0015] The flexural modulus of the ethylene-vinyl acetate copolymer (A) is 30 MPa or less. Since the flexural modulus is desirably low to provide tracking for the curved surfaces of the forming die, the flexural modulus is preferably 25 MPa or less, more preferably 20 MPa or less, and even more preferably 10 MPa or less. The flexural modulus is measured based on JIS K7116.

[0016] The content of vinyl acetate in the ethylene-vinyl acetate copolymer (A) is 5 to 45 mass %. That is, the ethylene-vinyl acetate copolymer (A) is obtained by copolymerizing a composition containing 5 to 45 mass % of vinyl acetate based on 100 mass % of the sum of ethylene and vinyl acetate. The amount of vinyl acetate is desirably large to provide followability for the curved surfaces of the molding die. The amount of vinyl acetate is preferably 10 mass % or more, more preferably 15 mass % or more, and most preferably 20 mass % or more. In addition, the amount of vinyl acetate is preferably 45 mass % or less, more preferably 40 mass % or less, and most preferably 30 mass % or less.

[0017] The wax (B) may be carnauba wax, candelilla wax, montan wax, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, polypropylene wax, any oxide of these waxes, ethylene-acrylic acid copolymer wax, ethylene-methacrylic acid copolymer wax, or the like. Only one type of these waxes may be used, or two or more types may be combined.

[0018] The amount of wax (B) is 0 to 30 mass % based on 100 mass % of the sum of (A), (B), and (C). The amount of wax (B) is preferably 3 mass % or more, and more preferably 5 mass % or more. In addition, the amount of wax (B) is preferably 20 mass % or less, and more preferably 15 mass % or less. When the amount is within the range, the hot-melt magnet material has good flexibility, trackability on the curved surface of the molding die when fixed to the molding die, and heat resistance. Therefore, it is preferable that the amount of wax (B) is within the range.

[0019] Wax (B) is added to improve the flowability and heat resistance of the hot-melt magnet material. Wax (B) is a low-viscosity material with a molecular weight of less than 1,000, making it difficult to measure the melt flow index of wax (B) based on JIS K7210. The kinematic viscosity of wax (B) is preferably 30 mm. 2 / s or less, more preferably 20 mm 2 / s or less and most preferably 10 mm 2 / s.

[0020] The melting point of the wax (B) is 70 to 160°C. Since the melting point of the wax (B) is desirably high to ensure the heat resistance of the hot-melt magnet material, the melting point of the wax (B) is preferably 80 to 150°C, more preferably 90 to 140°C, and particularly preferably 100 to 130°C. The melting point is measured based on JIS K2235.

[0021] The magnetic powder (C) may be a powdered magnetic material having ferromagnetism, for example, iron, nickel, cobalt, an alloy of these metals, ferrite, a rare earth metal such as gadolinium, a Heusler alloy, a manganese alloy such as Cu2MnAl, a compound of CrO2, CrBr3, or ZrZn2, etc. The particle size of the magnetic powder (C) may be 15 to 500 μm, and preferably 50 to 300 μm. If the particle size is less than 15 μm, the hot-melt magnetic material impregnated and immobilized in the fabric-like reinforcing material for urethane foam molding has a weak magnetic force for attracting the magnets of the molding die, so that wrinkles, loosening, or displacement of the fabric-like reinforcing material frequently occur during molding.When the particle size is more than 500 μm, there are some cases where it is difficult to obtain a uniform hot melt magnet material because of the tendency of insufficient dispersion of the magnetic powder (C) and the high sedimentation rate of the magnetic powder during the preparation of the hot melt magnet material.

[0022] The amount of magnetic powder (C) is 5 to 70 mass percent based on 100 mass percent of the sum of (A), (B), and (C). The amount of magnetic powder (C) is preferably 10 mass percent or more and / or 50 mass percent or less. If the magnetic powder (C) is less than 5 mass percent, the magnet-attracting force is weak, so that temporary fixing of the fabric-like reinforcing material during molding is often insufficient. As a result, there are many cases where wrinkles frequently form, or loosening or displacement of the fabric-like reinforcing material occurs during molding. If the magnetic powder (C) is more than 70%, the total amount of the ethylene-vinyl acetate copolymer (A) and the wax (B) is small, so it is difficult to obtain a uniform hot-melt magnet material.

[0023] The hot melt magnet material may contain 5 to 30 mass percent of additives such as glass filler, silica fibers, or liquid paraffin, based on 100 mass percent of the sum of (A), (B), and (C), to improve the dispersibility and flowability of the magnet powder (C), provided that the magnetic properties of attracting the magnets embedded in the molding tool are not impaired.

[0024] The viscosity of the hot melt magnet material at 150°C is 2,000 to 200,000 mPa s, preferably 5,000 to 100,000 mPa s, and more preferably 10,000 to 50,000 mPa s. If the viscosity of the hot melt magnet material is less than 2,000 mPa s, the magnetic powder (C) will settle in a short time, making it difficult to produce a uniform hot melt magnet material. If the viscosity of the hot melt magnet material is more than 200,000 mPa s, the discharge performance of the hot melt magnet material from the applicator is poor, and the hot melt magnet material tends to have the property of hardly penetrating the fabric-like reinforcing material.

[0025] The softening point of the hot-melt magnet material is 70 to 100°C. The softening point is preferably 80 to 100°C, and most preferably 85 to 95°C. If the softening point is less than 70°C, the hot-melt magnet material will melt during molding, since a normal molding temperature of the urethane foam molded article is 60 to 80°C. If the softening point is higher than 100°C, the hot-melt magnet material often has the property of being difficult to penetrate into the fabric-like reinforcing material. The softening point corresponds to a temperature measured according to the method defined as JIS K6863.

[0026] As in the Fig. 1 and Fig.As shown in Fig. 2, a fabric-like reinforcing material 1 for urethane foam molding according to an embodiment is obtained by impregnating a part of a surface of a nonwoven fabric 2 made of organic fibers with a hot-melt magnetic material 3 and immobilizing the hot-melt magnetic material 3. A condition of impregnation and immobilization means immobilizing by applying or dropping the hot-melt magnetic material 3, which is melted into a liquid state by heating, onto surfaces of specific locations of the nonwoven fabric 2, waiting for the liquid hot-melt magnetic material 3 to penetrate into the interior of the nonwoven fabric 2, and solidifying the hot-melt magnetic material 3 by air drying or cooling. In this case, the surface onto which the hot-melt magnetic material 3 is applied or dropped is a predetermined surface of the nonwoven fabric 2.When a multi-layer nonwoven fabric 2 is used, the liquid hot-melt magnetic material 3 applied or dropped onto the uppermost layer of the nonwoven fabric 2 can penetrate to a lower layer of the nonwoven fabric 2 and be immobilized therein.

[0027] The hot-melt magnet material is obtained by dispersively mixing a thermoplastic resin (ethylene-vinyl acetate copolymer), a mineral oil-based plasticizer, wax, and magnetic powder in an extruder, and extruding this molten mixture from a tip nozzle of the extruder. Alternatively, the magnetic powder is mixed and dispersed into a molten composition of the thermoplastic resin, the mineral oil-based plasticizer, and the wax using a melting pot with a mixture. It can be formed into various shapes, such as granule form, thread form, fiber form, rod form, or planar form, to adapt to the positions and various shapes of a seat molding die to which the fabric-like reinforcing material is applied. Furthermore, the planar form is preferably a film form, a sheet form, a mesh form, or a web-like form.When formed in the granule form, a conventional strand cutting method is used. When formed in the rod-like form, the hot melt magnet material is cut to a predetermined length after cooling. When formed in the thread form, the hot melt magnet material is wound up by means of a bobbin according to a conventional spinning method. When formed in the film form or the sheet form, a typical T-die method is used. When formed in the tape-like form, the film or sheet is cut and wound. When formed in the web-like form, particularly in the form of a nonwoven fabric, the same method can be applied to a hot melt nonwoven fabric manufacturing method under a condition where a porous die for manufacturing the hot melt nonwoven fabric is attached to the tip of the extruder.

[0028] The hot-melt magnetic material is melted and fluidized by energy such as heat or ultrasonic waves, allowing it to permeate a fiber layer of the fabric-like material for reinforcement. Furthermore, the hot-melt magnetic material can be easily molded into a desired shape based on a mold used during cooling. In this way, it is possible to immobilize the magnetic material in the desired shape at a target position of the fabric-like reinforcement material. The impregnation of the nonwoven fabric with the hot-melt magnetic material and the immobilization of the hot-melt magnetic material are performed by the following methods or the like.A first method includes fixing an original nonwoven fabric, disposing the hot melt magnetic material having the predetermined size and amount at predetermined positions on the fabric, heating the hot melt magnetic material with a hot plate such as iron to melt the hot melt magnetic material and impregnate the nonwoven fabric with the hot melt magnetic material, and pressing and cooling the hot melt magnetic material with a cold metal bar or the like to immobilize the hot melt magnetic material.A second method includes placing the predetermined size and quantity of hot-melt magnetic material at predetermined positions on the forming die, fixing a nonwoven fabric to the forming die, heating the hot-melt magnetic material from above the nonwoven fabric with a hot plate such as an iron to melt the hot-melt magnetic material and impregnate the nonwoven fabric with the hot-melt magnetic material, and pressing and cooling the hot-melt magnetic material with a cold metal bar or the like to immobilize the hot-melt magnetic material. In this case, it is preferable to provide a Teflon film as a separating material between the hot-melt magnetic material and a heat source during the heating step.A third method comprises melting the granular hot-melt magnetic material, applying the hot-melt magnetic material to predetermined locations of the nonwoven fabric while extruding the hot-melt magnetic material in a ribbon shape, a fiber shape, a dot shape, a cotton shape, or a net shape from an outlet nozzle of a hot-melt applicator used for the T-die method, spray method, or gravure roll transfer method, and cooling the hot-melt magnetic material to immobilize it.

[0029] A method for producing the urethane foam molded article using the third method will be described in more detail. A roughly cut, sheet-like nonwoven fabric is attached to a metal mold having a plurality of vent holes connecting an outer surface and an inner space. The metal mold is covered with a heat-resistant film, and then the interior of the film is heated with high-temperature steam. Then, the pressure inside the film is reduced, thereby transferring the shape of the metal mold to the sheet-like nonwoven fabric. After the metal mold is cooled, the molded nonwoven fabric is removed from the metal mold. The ribbon-shaped hot-melt magnetic material extruded from the outlet nozzle of the T-die hot-melt applicator is applied to predetermined locations on the molded nonwoven fabric and then cooled for immobilization.The nonwoven fabric, in which the hot-melt magnetic material is immobilized at predetermined locations, is inserted into a cavity of a urethane foam molding die in which magnets are embedded at predetermined locations. Foam molding is performed by injecting a liquid urethane composition into the cavity and then releasing a urethane foam molded article from the molding die. Embodiment

[0030] Next, concrete examples and comparative examples of the present disclosure will be described. However, the present disclosure is not limited to these. Production of a hot-melt magnet material

[0031] The ethylene-vinyl acetate copolymer (A), the wax (B), if necessary, and the additives were mixed for 5 minutes in a Henshel-type mixer. The mixture was transferred to a hopper and then fed into an extruder using a screw feeder. Further, the magnetic powder (C) was added to the extruder at a predetermined ratio using another screw feeder to obtain a hot-melt magnetic material. The following Tables 1 and 2 show the type and amount of each component. Extruder: Co-rotating twin-screw extruder PMT32-40.5, manufactured by IKG Corporation Cylinder temperature: 100 °C (feed opening 80 °C) (adjusted if necessary) Screw speed: 100 rpm Feed speed: 5 kg / h Preparation of a fabric-like reinforcing material for urethane foam molding

[0032] The resulting hot-melt magnet material was formed into a disc shape with a diameter of 15 mm (weight: 0.4 to 0.6 g) and placed on an iron stand. The hot-melt magnet material was covered with a nonwoven fabric made of organic fibers and a Teflon coating was used for separation. ®The hot-melt magnet material was applied to the nonwoven fabric. The hot-melt magnet material was heated and melted by pressing the film from above for 3 seconds with an iron whose temperature was controlled at 150°C using a temperature controller to liquefy the hot-melt magnet material and impregnate the nonwoven fabric with the hot-melt magnet material. The hot-melt magnet material was then cooled with a cold rod to obtain a fabric-like reinforcing material for urethane foam molding.

[0033] Nonwoven fabric made of organic fibers: Single-layer dry nonwoven fabric with a weight of 140 g / m 2 , produced using a carding process from mixed fibres containing 70% by mass of polyester short fibres (fineness 2.2 dtex) and 30% by mass of bicomponent short fibres (fineness 2.2 dtex) of polyethylene and polypropylene.

[0034] With respect to the ethylene-vinyl acetate copolymer (A), the melting point in Tables 1 and 2 means a melting peak temperature.

[0035] Each of the components shown in Tables 1 and 2 is shown below. A-1 ultrasen 760 (ethylene-vinyl acetate copolymer manufactured by Tosoh Corporation, vinyl acetate content 42%, MFR 70 g / 10 min (190 °C×2, 16 kg), flexural modulus 1 MPa, melting peak temperature 50 °C or less). A-2 ultrasen 722 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 28%, MFR 400 g / 10 min (190 °C×2, 16 kg), flexural modulus 10 MPa, melting peak temperature 58 °C). A-3 ultrasen 720 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 28%, MFR 150 g / 10 min (190 °C×2, 16 kg), flexural modulus 10 MPa, melting peak temperature 59 °C). A-4 ultrasen 751 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 28%, MFR 5.7 g / 10 min (190 °C×2, 16 kg), flexural modulus 20 MPa, melting peak temperature 65 °C). A-5 ultrasen 681 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 20%, MFR 350 g / 10 min (190 °C×2, 16 kg), flexural modulus 20 MPa, melting peak temperature 72 °C). A-6 ultrasen 633 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 20%, MFR 20 g / 10 min (190 °C×2, 16 kg), flexural modulus 30 MPa, melting peak temperature 78 °C). A-7 ultrasen 631 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 20%, MFR 1.5 g / 10 min (190 °C×2, 16 kg), flexural modulus 40 MPa, melting peak temperature 80 °C). A-8 ultrasen 638 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 20%, MFR 13 g / 10 min (190 °C×2, 16 kg), flexural modulus 30 MPa, melting peak temperature 82 °C). A-9 ultrasen 625 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 15%, MFR 14 g / 10 min (190 °C×2, 16 kg), flexural modulus 50 MPa, melting peak temperature 92 °C). A-10 ultrasen 541 (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, vinyl acetate content 10%, MFR 9 g / 10 min (190 °C×2, 16 kg), flexural modulus 80 MPa, melting peak temperature 94 °C).

[0036] Wax (B) B-1 sasol H1 (Fischer-Tropsch wax, manufactured by Sasol in South Africa, melting point 110 °C). B-2 high wax NL800 (polyethylene wax, manufactured by Mitsui Chemicals, Incorporated, melting point 105 °C). B-3 biscol 660-P (Sanyo Chemical Industries, Ltd., melting point 145 °C).

[0037] Magnetic powder (C) C-1 JIP300A-120 (magnetic powder manufactured by JFE Steel Corporation). C-2 C-100 (magnetic powder manufactured by Powdertech Co.,Ltd.).

[0038] Additive Antioxidant IRGANOX1010 (manufactured by Ciba Specialty Chemicals) Anti-blocking agent Incroslip C (manufactured by Croda)

[0039] The resulting hot-melt magnet materials and the fabric-like reinforcing materials for urethane foam molding were tested by conducting the following tests. The test results are also shown in Tables 1 and 2. Tests for hot melt magnetic materialMelt viscosity measurement

[0040] The melt viscosity was measured using the dynamic viscoelasticity measuring device Rheosol-G3000, manufactured by UBM Co., Ltd. The measurement method includes placing a simple cone with a diameter of 40 mm and an inclination angle of 2° above a measuring part, placing a simple plate with a diameter of 40 mm below the measuring part, holding a sample between the cone and the plate, holding it for 15 minutes at 150 °C, and then measuring the melt viscosity of the sample at a shear rate of 2.9 (cm -1 ) while maintaining the same state. Evaluation of the spreadability of the hot melt magnet material

[0041] A test piece made of the hot-melt magnet material, formed into a cylindrical shape with a diameter of 5 mm and a height of 8 mm (weighing 0.4 to 0.6 g), was placed on an iron frame. The test piece was covered from above with a piece of nonwoven fabric made of organic fibers. A Teflon membrane was used for separation. ® The hot-melt magnet film was then applied to the nonwoven fabric. The hot-melt magnet material was then heated and melted by pressing the film from above for 2 seconds with an iron whose temperature was set to 150 °C using a temperature controller to evaluate the spreadability of the hot-melt magnet material. O The hot melt magnet material spreads out into a disc shape with a diameter of 15 mm or more. Δ The hot melt magnet material spreads in a disc shape with a diameter of 10 mm or more and less than 15 mm. X The hot melt magnet material spreads out into a disc shape with a diameter of less than 10 mm. Evaluation of the fabric-like reinforcing material for urethane foam moldingAttractiveness (adhesive property) of a hot-melt magnetic material to a magnet

[0042] The attraction ability (adhesive property) was evaluated by bringing the hot melt magnetic material, which is permeated and immobilized in the fabric-like material for reinforcement, into contact with a permanent magnet (2800 G) with a weight of 10 g and a diameter of 6 mm and then lifting the fabric-like material. O The magnet was completely lifted into the air. Δ The magnet was lifted but fell easily when lightly touched. X The magnet was not lifted. Heat resistance

[0043] The woven reinforcement material was placed between a pair of aluminum plates and held at 70 °C for 30 minutes while a 2 kg load was applied. After removal, the aluminum plates were quickly peeled off. The transfer of the hot-melt material to the aluminum plates was then observed. O The hot melt magnet material was not transferred. Δ The amount of hot melt magnet material transferred to the aluminum plates was 20% or less. X The amount of hot melt magnet material transferred to the aluminum plates was 50% or more. Tracking along a curved surface

[0044] The fabric-like reinforcement material was visually observed when the hot-melt magnetic material, which is permeated and immobilized in the fabric-like material for reinforcement, is brought into contact with a magnetic sphere (a neodymium magnet, diameter 10 mm). O The fabric-like reinforcement material was deformed along a curved surface of the magnetic sphere. Δ The fabric-like reinforcing material was bent but not deformed into a shape along the curved surface of the magnetic sphere. X The fabric-like reinforcing material was not deformed. Integration capability (immobilization force) of a hot-melt magnetic material with fabric-like reinforcing material

[0045] The evaluation was performed by manually peeling off the hot melt magnetic material immobilized in the fabric-like reinforcing material and visually inspecting the damaged surface of the peeled nonwoven fabric. O The hot-melt magnet material could not be removed without pulling forcefully. Alternatively, when the hot-melt magnet material was peeled off, the surface of the nonwoven fabric was severely damaged, e.g., the formation of many lints or an opening. Δ The hot melt magnet material could be detached with little force, and little lint was observed on the surface of the nonwoven fabric. X The hot melt magnet material could be easily peeled off without damage to the hot melt magnet material, and the surface of the nonwoven fabric was not seriously damaged. Result

[0046] A hot-melt magnetic material with heat resistance and flexibility could be obtained by using a hot-melt magnetic material having a specific softening point of 70 to 100°C according to the features of this disclosure, so that it was capable of significantly improving the trackability of the fabric-like reinforcing material for urethane foam molding along a curved surface. The trackability of the fabric-like reinforcing material for urethane foam molding along a curved surface was further improved by using ethylene-vinyl acetate copolymer (A) having a melting peak temperature of 50 to 70°C. The above description demonstrates the fact that a fabric-like reinforcing material for urethane foam molding containing the specific hot-melt magnetic material of this disclosure solves a problem related to the trackability along the curved surface of the molding die.

Claims

[1] A fabric-like reinforcing material for urethane foam molding obtained by impregnating a part of a surface of a nonwoven fabric with a hot-melt magnetic material and immobilizing the hot-melt magnetic material, wherein the hot melt magnet material satisfies the composition described below and has a softening point of 70 to 100 °C, and the melting peak temperature of the ethylene-vinyl acetate copolymer (A) is 50 to 75 °C: Ethylene-vinyl acetate copolymer (A): 10 to 95 mass percent, Wax (B): 0 to 30 mass percent, Magnetic powder (C): 5 to 70 mass percent, where the sum of components (A), (B) and (C) is 100 mass percent. [2] A fabric-like reinforcing material for urethane foam molding according to claim 1, wherein the hot-melt magnetic material satisfies the composition described below: Ethylene-vinyl acetate copolymer (A): 30 to 95 mass percent, Wax (B): 0 mass percent, Magnetic powder (C): 5 to 70 mass percent, where the sum of components (A), (B) and (C) is 100 mass percent. [3] A fabric-like reinforcing material for urethane foam molding according to claim 1, wherein the hot-melt magnetic material satisfies the composition described below: Ethylene-vinyl acetate copolymer (A): 10 to 80 mass percent, Wax (B): 3 to 30 mass percent, Magnetic powder (C): 5 to 70 mass percent, where the sum of components (A), (B) and (C) is 100 mass percent. [4] The fabric-like reinforcing material for urethane foam molding according to any one of claims 1 to 3, wherein the content of vinyl acetate is 20 to 45 mass% based on 100 mass% of the ethylene-vinyl acetate copolymer (A). [5] The fabric-like reinforcing material for urethane foam molding according to any one of claims 1 to 4, wherein the melting peak temperature of the ethylene-vinyl acetate copolymer (A) is 50 to 70°C. [6] A method for producing a urethane foam molded article using the fabric-like reinforcing material for urethane foam molding according to any one of claims 1 to 5, comprising: a fixing step of fixing the fabric-like reinforcing material for urethane foam molding by magnetic force on a molding surface of a molding die containing magnets embedded at some predetermined locations, a urethane foam molding step of injecting a urethane resin into the molding die and foaming the urethane resin to mold the urethane resin integrally with the fabric-like reinforcing material for urethane foam molding, and a mold release step for removing a urethane foam molded article obtained by foam molding from the molding die.

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