Method for producing bell structure, and bell structure

Abstract

This method for producing a bell structure includes: step A for preparing a composite particle having a core particle and a water-soluble material that covers said core particle; step B for obtaining a precursor for thermoforming, which contains the composite particle and a thermosetting resin particle or a coated particle coated with a thermoplastic resin; step C for thermoforming the precursor for thermoforming to obtain a resin molded body containing the composite particle; and step D for bringing the resin molded body into contact with a solution containing water or an alcohol.

Description

Bell structure manufacturing method and bell structure

[0001] The present invention relates to a method for manufacturing a bell structure and a bell structure.

[0002] Bell structures have been attracting attention as components for vibration-damping materials, sound-proofing panels, etc. Bell structures have a structure that includes a substrate with voids inside and particles contained within the voids. Such bell structures can attenuate incident vibration or sound energy by converting it into particle movement within the voids.

[0003] Bell structures have been developed in the past. For example, Patent Document 1 listed below proposes a method for producing a sound-insulating board with a bell-shaped structure by kneading particles coated with a foaming agent into a resin, molding the resin into a plate, and then foaming it.

[0004] Japanese Patent Application Publication No. 9-226035

[0005] However, in the above method, since pores are formed by foaming, it is difficult to control variations in the size and shape of the pores.

[0006] An object of the present invention is to provide a method for manufacturing a bell structure and a bell structure that enable the formation of a desired bell structure.

[0007] One aspect of the present invention includes the following methods for manufacturing a bell structure [1] to [6].

[0008] [1] A method for manufacturing a bell structure, comprising: Step A: preparing composite particles having core particles and a water-soluble material coating the core particles; Step B: obtaining a precursor for heat molding containing the composite particles and thermosetting resin particles or coated particles coated with a thermoplastic resin; Step C: heat molding the precursor for heat molding to obtain a resin molded body containing the composite particles; and Step D: contacting the resin molded body with a solution containing water or alcohol. [2] The method for manufacturing a bell structure according to [1], wherein the solution further contains a surfactant. [3] The method for manufacturing a bell structure according to [1] or [2], wherein the resin molded body has a porosity of 10 to 80 volume %. [4] The method for manufacturing a bell structure according to any one of [1] to [3], wherein the water-soluble material contains at least one material selected from the group consisting of sugars, synthetic polymers, and inorganic salts. [5] The method for manufacturing a bell structure according to any one of [1] to [4], wherein the melting point of the water-soluble material exceeds the heating temperature in Step C. [6] The method for manufacturing a bell structure according to any one of [1] to [4], wherein the core particles are metal particles.

[0009] In the method described in [1] above, steps A to C make a resin molded body containing composite particles porous, while forming interconnected pores that extend from the surface of the composite particles to the outside of the resin molded body. This allows the water-soluble material of the composite particles to be removed in step D, forming a bell structure comprising a porous resin base, pores provided within the resin base, and particles (the above-described core particles) that can move within the pores. This method makes it possible to control the size and shape of the pores by adjusting the size and shape of the composite particles and the amount of water-soluble material coated on them, and thus makes it easy to obtain a bell structure having the desired bell structure.

[0010] Another aspect of the present invention includes the following bell structures [7] to

[11] .

[0011] [7] A bell structure comprising a porous resin substrate, voids provided inside the resin substrate, and particles capable of moving within the voids. [8] The bell structure according to [7], wherein the resin substrate has interconnected pores leading from the voids to the outside of the resin substrate. [9] The bell structure according to [8], wherein at least a portion of the interconnected pores is filled with a water-soluble material.

[10] The bell structure according to any one of [7] to [9], wherein the resin substrate includes a cured product of thermosetting resin particles.

[11] The bell structure according to any one of [7] to

[10] , wherein the particles are metal particles.

[0012] According to the present invention, it is possible to provide a manufacturing method of a bell structure and a bell structure that enable the formation of a desired bell structure.

[0013] Fig. 1 is a schematic cross-sectional view showing one embodiment of a bell structure according to the present invention. Fig. 2 is a schematic cross-sectional view showing one embodiment of a composite particle used in the method for manufacturing a bell structure according to the present invention. Fig. 3 is a schematic cross-sectional view showing a precursor for hot molding used in the method for manufacturing a bell structure according to the present invention. Fig. 4 is a schematic cross-sectional view showing a resin molded body used in the method for manufacturing a bell structure according to the present invention. Fig. 5 is a view showing a cross-sectional image of the bell structure obtained by micro-CT scanning.

[0014] Hereinafter, embodiments of a bell structure and a method for manufacturing a bell structure according to the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted.

[0015] [Method for manufacturing bell structure] The method for manufacturing the bell structure of this embodiment includes the steps of: step A of preparing composite particles having a core particle and a water-soluble material that coats the core particle; step B of obtaining a precursor for heat molding that includes the composite particle and a thermosetting resin particle or a coated particle coated with a thermoplastic resin; step C of heat molding the precursor for heat molding to obtain a resin molded body containing the composite particle; and step D of contacting the resin molded body with a solution containing water or an alcohol.

[0016] According to the manufacturing method of the bell structure of this embodiment, it is possible to obtain a bell structure comprising a porous resin base, voids provided inside the resin base, and particles that can move within the voids.

[0017] Fig. 1 is a schematic cross-sectional view showing one embodiment of a bell structure. The bell structure 1 shown in Fig. 1 comprises a porous resin substrate 4, pores 3 provided inside the resin substrate 4, and particles 2 that can move within the pores 3. A method for manufacturing the bell structure of this embodiment will be described below, taking the case of manufacturing the bell structure 1 as an example.

[0018] (Step A) In step A, as shown in FIG. 2, a composite particle 10 having a core particle 2a and a water-soluble material 5 that coats the core particle 2a is prepared.

[0019] The material of the core particle 2a is not particularly limited, but may be, for example, one or more of a resin material, an inorganic material, and a metal material.

[0020] When the core particle 2a has a resin material or is made of a resin material, the resin material that constitutes the core particle 2a can be, for example, a thermosetting resin such as a phenol resin or an epoxy resin.

[0021] When the core particle 2a has an inorganic material or is made of an inorganic material, for example, ceramic or carbon material can be used as the inorganic material that constitutes the core particle 2a.

[0022] When the core particle 2a has a metal material or is made of a metal material, the metal material constituting the core particle 2a may be, for example, iron, copper, tin, aluminum, or any of various alloys.

[0023] The core particles 2a may be metal particles or copper particles. In this case, particles with a high specific gravity can be accommodated in the pores, and the kinetic energy of the particles in the pores is increased, which makes it easier to increase energy loss in vibration and sound.

[0024] The maximum particle size of the core particle 2a is not particularly limited, but can be, for example, 0.1 μm to 500 μm, 1 μm to 100 μm, or 1 μm to 10 μm. The core particle 2a may be spherical, such as a perfect sphere, or non-spherical, such as a columnar or flat shape. In this specification, the maximum particle size of a particle refers to the diameter of the particle at the position where the particle size is largest.

[0025] The water-soluble material 5 may be any material that dissolves in a solution containing water or alcohol, and may be, for example, at least one material selected from the group consisting of sugars, synthetic polymers, and inorganic salts.

[0026] Examples of sugars include monosaccharides such as granulated sugar and glucose, and water-soluble polysaccharides such as guar gum and sodium alginate. Examples of synthetic polymers include polyvinyl alcohol (PVA), carboxymethyl cellulose, and polyacrylic acid. Examples of inorganic salts include water-soluble salts such as sodium chloride and calcium chloride.

[0027] The melting point of the water-soluble material may be a temperature higher than the heating temperature in step C from the viewpoint of controlling the shape and size of the pores formed inside the resin base, and may be 150 to 300°C, since the softening temperature or hardening temperature of a thermosetting resin suitably used as a resin substrate and the softening temperature of a thermoplastic resin are generally 140 to 250°C.

[0028] Methods for coating the core particles 2a with the water-soluble material 5 include dip coating and spray coating. In these methods, the water-soluble material may be dissolved in a solvent or heated and melted before use, as necessary. Also, known wet and dry methods for producing coated particles may be used. In the wet method, a liquid in which the water-soluble material is dissolved or suspended may be sprayed onto the core particles, and then the liquid may be evaporated. In the dry method, the water-soluble material may be attached to the core particles using a dry binder.

[0029] According to the method of this embodiment, pores corresponding to the external shape of the composite particles can be formed, and therefore the amount of coating water-soluble material may be adjusted so that the pores have the desired shape and size.

[0030] The composite particles prepared in step A may have the same or different shapes and sizes, and one composite particle may contain a plurality of core particles.

[0031] (Step B) In step B, the composite particles prepared in step A and thermosetting resin particles or coated particles coated with a thermoplastic resin are mixed in a predetermined ratio to obtain a thermoforming precursor. The thermoforming precursor 30 shown in Figure 3 contains a mixture of composite particles 10 and thermosetting resin particles 20 filled in a predetermined mold 22.

[0032] Examples of the thermosetting resin particles 20 include phenolic resin particles, epoxy resin particles, melamine resin, and polyurethane resin. The thermosetting resin particles 20 may be semi-cured or polymerized, from the viewpoint of facilitating porosity adjustment during molding.

[0033] The maximum particle size of the thermosetting resin particles 20 is not particularly limited, but may be, for example, 0.1 μm to 1000 μm, 1 μm to 100 μm, or 5 μm to 50 μm. The thermosetting resin particles 20 may be spherical, such as a perfect sphere, or non-spherical, such as a columnar or flat shape.

[0034] The blending ratio of the composite particles is not particularly limited, but may be set so that the volume of the composite particles relative to the volume of the molded body after heat molding is 1 to 50% by volume, or 10 to 30% by volume.

[0035] When using coated particles coated with a thermoplastic resin, examples of core particles that coat the thermoplastic resin include thermoplastic resin particles, thermosetting resin particles, etc. Examples of thermoplastic resin particles include polyethylene particles, polypropylene particles, polyethylene terephthalate particles, polyamide particles, etc. Examples of thermosetting resin particles that can be used are the same as the thermosetting resin particles 20.

[0036] The coated particles coated with a thermoplastic resin may be those in which a thermoplastic resin particle is used as a core particle and is coated with a thermoplastic resin having a lower melting point than the core particle. In this case, for example, a polyethylene particle having a melting point of 130 to 140°C may be used as the core particle and coated with polyethylene having a melting point of 95 to 120°C.

[0037] The maximum particle size of the coated particles coated with the thermoplastic resin and the blending ratio with the composite particles can be the same as those of the thermosetting resin particles 20 described above.

[0038] (Step C) In step C, the above-mentioned thermoforming precursor is thermoformed to obtain a resin molded body 40 composed of a porous resin base 4 and composite particles 10 contained inside the resin base 4, as shown in FIG.

[0039] The heating temperature can be set lower than the melting point of the water-soluble material 5 from the viewpoint of maintaining the shape of the water-soluble material 5, and may be 100 to 250°C in view of the relationship between the softening temperature or hardening temperature of a general thermosetting resin and the softening temperature of a thermoplastic resin and the melting point of the exemplified water-soluble material.

[0040] Pressure may be applied during the thermoforming process, for example, at the above temperature and under a pressure of 0.005 to 20 MPa.

[0041] From the viewpoint of quickly dissolving the water-soluble material and ensuring good material strength, the resin molded body 40 may have a porosity of 10 to 80% by volume, or 20 to 50% by volume. In this specification, the porosity refers to a value calculated from the density measured in accordance with JIS K7112 and the true density of the resin molded body.

[0042] The porosity of the resin molded body can be adjusted to a desired range by, for example, adjusting the particle size of the thermosetting resin particles or the coated particles coated with a thermoplastic resin, adjusting the pressure during heat molding, or adjusting the amount of resin poured into a molding die for molding at a constant volume.

[0043] Furthermore, by the above adjustment, it is possible to form, in the porous resin base 4 , communicating pores (not shown) that communicate from the surface of the composite particle 10 to the outside of the resin molded body 40 .

[0044] (Step D) In ​​step D, the resin molded body 40 is brought into contact with a solution containing water or alcohol (hereinafter, sometimes referred to as "solution D") to remove the water-soluble material 5 from the composite particle 10.

[0045] The alcohol contained in solution D includes ethanol, methanol, propanol, and butanol.

[0046] Solution D may further contain a wetting agent from the viewpoint of improving wettability with the porous resin substrate 4 and facilitating removal of the water-soluble material 5 of the composite particle 10. Examples of wetting agents include ionic surfactants such as anionic, cationic, and amphoteric surfactants, nonionic surfactants, and silicone surfactants.

[0047] The contact angle of the solution D with respect to the resin constituting the resin base 4 may be 10 to 90°, or may be 10 to 60°. The contact angle can be measured, for example, in accordance with JIS K6768.

[0048] As a method for contacting the resin molded body 40 with the solution D, a method of immersing the resin molded body in the solution D and stirring the solution D with a stirrer or the like to cause convection may be mentioned.

[0049] Through step D, the bell structure 1 shown in FIG. 1 can be obtained.

[0050] In this embodiment, in order to improve the mechanical strength of the bell structure 1, the water-soluble material 5 of the composite particle 10 may be removed from the resin molding 40 so that the water-soluble material fills at least a portion of the communicating pores formed in the resin base 4.

[0051] For example, when dissolving the water-soluble material with solution D, the water-soluble material may not be completely removed from the resin molded body, and the cleaning may be stopped midway through the cleaning process, so that the water-soluble material remains in at least some of the communicating pores.

[0052] In this embodiment, the interconnected pores may be filled with a filler material such as a water-soluble material or liquid resin after removing the water-soluble material 5 of the composite particle 10 from the resin molded body 40. In this case, the amount of the water-soluble material, liquid resin, or the like impregnated into the resin molded body can be appropriately adjusted to fill the interconnected pores with the filler material.

[0053] [Bell Structure] The bell structure of this embodiment includes a porous resin substrate, pores provided inside the resin substrate, and particles that can move within the pores.

[0054] The bell structure of this embodiment can be manufactured by the manufacturing method of the bell structure of this embodiment described above. The bell structure of this embodiment may have a configuration similar to that of the bell structure 1 shown in FIG.

[0055] The porous resin substrate may be a cured product of the above-mentioned thermosetting resin particles, or may be a cured product of the above-mentioned coated particles coated with a thermoplastic resin.

[0056] The porous resin substrate may have interconnected pores that extend from the pores to the outside of the resin substrate. To improve the mechanical strength of the bell structure, at least a portion of the interconnected pores may be filled with a water-soluble material or a filler material. The water-soluble material may be the same as the water-soluble material 5 described above. The filler material may be any of the materials described above.

[0057] The particles may be the same as the core particles 2a described above.

[0058] The bell structure of this embodiment can be applied to vibration damping materials, sound insulating materials, and sound absorbing materials.

[0059] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0060] [Preparation of Bell Structure] (Example 1) Copper particles (maximum particle size: about 400 μm) were coated with heated and melted granulated sugar by dropping it onto the particles to obtain composite particles with a maximum particle size of 1.2 mm.

[0061] A mixture was obtained by mixing 2 parts by weight of the composite particles obtained above with 15 parts by weight of polymerized phenolic resin powder (manufactured by Air Water Performance Chemicals Co., Ltd., product name "Bellpearl S830", maximum particle size: 20 μm). This mixture was filled into a 50 mm x 50 mm x 3.5 mm deep mold and thermo-compressed at a temperature of 150°C and a pressure of 0.01 MPa to obtain a resin molded body containing the composite particles. The porosity of the resin molded body was approximately 40% by volume.

[0062] The resin molded body obtained above was washed with water containing 1% by mass of "SN Wet 126" (product name, manufactured by San Nopco Ltd.) as a wetting agent, to obtain a bell structure.

[0063] A cross-sectional image of the obtained bell structure was taken by micro-CT scanning. As shown in FIG. 5, it was confirmed that pores with a maximum diameter of approximately 1.2 mm were formed inside the porous resin base and that copper particles were contained in the pores.

[0064] DESCRIPTION OF SYMBOLS 1...bell structure, 2...particle, 2a...core particle, 3...hole, 4...porous resin base, 5...water-soluble material, 10...composite particle, 20...thermosetting resin particle, 22...mold, 30...thermoforming precursor, 40...resin molded body.

Claims

1. Step A of preparing composite particles having nuclear particles and a water-soluble material coating the nuclear particles; Step B of obtaining a precursor for hot molding including the composite particles and thermosetting resin particles or coated particles coated with a thermoplastic resin; Step C of hot molding the precursor for hot molding to obtain a resin molded body containing the composite particles; and Step D of bringing the resin molded body into contact with a solution containing water or alcohol. A method for manufacturing a bell structure comprising these steps.

2. The method for manufacturing a bell structure according to claim 1, wherein the solution further contains a surfactant.

3. The method for manufacturing a bell structure according to claim 1, wherein the porosity of the resin molded body is 10 to 80% by volume.

4. The method for manufacturing a bell structure according to claim 1, wherein the water-soluble material contains at least one material selected from the group consisting of saccharides, synthetic polymers, and inorganic salts.

5. The method for manufacturing a bell structure according to claim 1, wherein the melting point of the water-soluble material is a temperature exceeding the heating temperature in Step C.

6. The method for manufacturing a bell structure according to claim 1, wherein the nuclear particles are metal particles.

7. A bell structure comprising a porous resin substrate, pores provided inside the resin substrate, and particles capable of moving within the pores.

8. The bell structure according to claim 7, wherein the resin substrate has communicating pores leading from the pores to the outside of the resin substrate.

9. The bell structure according to claim 8, wherein at least a part of the communicating pores is filled with a water-soluble material.

10. The bell structure according to claim 7, wherein the resin substrate contains a cured product of thermosetting resin particles.

11. The bell structure according to claim 7, wherein the particles are metal particles.