Coating-equipped foaming base material

Abstract

To provide a coating-equipped foaming base material in which a foaming base material body and a coating on its outer circumference contain different resin materials.SOLUTION: A coating-equipped foaming base material 1 includes: a foaming base material 10 containing a first resin material; and a coating 29 containing a second resin material different from the first resin material, the coating 29 being formed to be welded on at least a surface of the foaming base material 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a film-coated foam substrate comprising a foam substrate and a film. [Background technology]

[0002] Patent Document 1 discloses a ceramic filter substrate comprising a main body made of an ester-based polyurethane foam and an outer periphery formed around the main body. In this substrate, the main body is made of a specific ester-based polyurethane foam from which the cell membrane has been removed, and the outer periphery has a coating surface formed by melting and solidifying the outer periphery of the same polyurethane foam to seal the periphery. In other words, the outer periphery of the foam is covered with a film made of the foam's own material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-218344 Summary of the Invention [Problem to be solved by the invention]

[0004] The coating of such a coating-coated foamed substrate is formed from the main body of the foamed substrate, and therefore has the same properties as the main body.

[0005] On the other hand, such a foamed substrate cannot be used when different properties are required for the main body and the coating. In order to solve this problem, an object of the present invention is to provide a foamed substrate with a coating, in which the foamed substrate main body and the coating formed on its outer periphery contain different resin materials. [Means for solving the problem]

[0006] A film-coated foam substrate according to one embodiment of the present disclosure comprises a foam substrate containing a first resin material and a film formed by welding to at least one surface of the foam substrate, the film containing a second resin material different from the first resin material. [Effects of the Invention]

[0007] The film-attached foam substrate according to one embodiment of the present disclosure allows for a wide variety of combinations of film types and foam substrate types, making it possible to meet a variety of needs. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a film-coated foam substrate in one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic perspective view of a film-coated foam substrate in another embodiment of the present invention. [Figure 3] FIG. 2 is a schematic perspective view of a film-coated foam substrate in another embodiment of the present invention. [Figure 4] FIG. 1 is a diagram showing the formation of a molten film by hot pressing. [Figure 5] FIG. 1 is a diagram showing the formation of a molten film by a heated roll. [Figure 6] FIG. 10 is a diagram showing the formation of a coating using an annular mold. [Figure 7] 1 is a schematic diagram showing a state in which a film-forming member is superimposed on a foam substrate, in which the longitudinal direction of the depth of the foam substrate is omitted. DETAILED DESCRIPTION OF THE INVENTION

[0009] The film-coated foam substrate 1 can be used, for example, as a sealing material, a sound-absorbing material, a filter material, a ceramic filter substrate, etc. As a specific example of its use, the film-coated foam substrate 1 of this embodiment is used as a substrate for producing ceramic filters. Ceramic filters are prone to chipping at their corners and edges during transportation or installation in castings, and therefore require improved corner and edge strength. Therefore, the film-coated foam substrate 1 is suitable as a ceramic filter substrate.

[0010] 1 to 3 show a resin film-attached foam substrate 1 in the shape of a sheet, a rectangular parallelepiped, or a cylinder. The shape of the film-attached foam substrate 1 may be a polygonal prism such as a prism, a square prism, or a regular square prism, an ellipse, or a disk. The film-attached foam substrate 1 of this embodiment has a foamed foam substrate 10 and a film 29 formed on at least one surface of the foam substrate 10.

[0011] 1 shows a sheet-like film-coated foam substrate 1. The foam substrate 10 has a top surface 91, a bottom surface 92 opposite the top surface 91, and an end surface 94 connected between the top surface 91 and the bottom surface 92. The film 29 is welded only to the top surface 91 of the foam substrate 10.

[0012] FIG. 2 shows a rectangular parallelepiped foam substrate 1 with a coating. This foam substrate 10 may be a cut prism. The foam substrate 10 has a first surface 11, a second surface 12 opposite the first surface 11, and an outer circumferential surface 14 connected between the first surface 11 and the second surface 12. The outer circumferential surface 14 includes four side surfaces. A coating 29 is welded to the outer circumferential surface 14 of the foam substrate 10.

[0013] 3 shows a cylindrical foam substrate 1 with a coating. The foam substrate 10 has a first surface 11, a second surface 12 opposite the first surface 11, and an outer peripheral surface 14 connected between the first surface 11 and the second surface 12. The coating 29 is welded to the outer peripheral surface 14 of the foam substrate 10.

[0014] 2 and 3, the coating 29 is formed over the entire outer peripheral surface 14. However, this is not limiting, and the coating 29 may be formed only on a portion of the outer peripheral surface 14. The coating 29 formed over the entire outer peripheral surface 14 may have through holes as long as the desired coating 29 is formed. <Foam base material>

[0015] The foam substrate 10 includes a first resin material. The first resin material may be a thermoplastic resin or a thermosetting resin. Examples of thermoplastic resins include polyethylene, polypropylene, polystyrene, and polyvinyl chloride. Examples of thermosetting resins include polyurethane. The foam substrate 10 may be, for example, a thermoplastic resin foam or a thermosetting resin foam, but a thermosetting resin foam, particularly a polyurethane foam, is preferred.

[0016] The foam substrate 10 may be an elastically deformable foam that is soft at room temperature, bends when compressed, and then returns to its original shape when the compression is released. Examples of the foam substrate 10 include a semi-rigid foam and a soft foam, and a soft foam is more preferred.

[0017] Thermosetting resin foams are produced by polymerizing a raw material composition to form a cross-linked polymer. Because the resulting foam has a cross-linked structure, it usually has good thermal compression recovery (thermal distortion resistance) and is resistant to thermal softening or shrinkage, allowing for a wide range of temperature settings during melt film molding.

[0018] Polyurethane foam is suitable for the foam substrate 10 because the degree of flexibility (elasticity) or softness can be easily adjusted and it has good thermal compression recovery. The polyurethane foam may be a semi-rigid polyurethane foam or a soft polyurethane foam, and foams of various hardnesses can be used for the foam substrate 10. Specific examples of polyurethane foam include polyether-based polyurethane foam, polyetherester-based polyurethane foam, and polyester-based polyurethane foam.

[0019] The foaming substrate 10 can be manufactured using raw materials for producing ordinary thermoplastic resin foams or raw materials for producing ordinary thermosetting resin foams. Specifically, in the case of polyurethane foams, polyester polyols, polyetherester polyols, polyether polyols, and compounds having ether groups can be used as the polyol component in the polyurethane foam-producing composition. Other raw materials for producing polyurethane foams include, for example, polyisocyanates, blowing agents, crosslinking agents, chain extenders, catalysts, foam stabilizers, pigments, and other auxiliary agents used in producing ordinary polyurethane foams.

[0020] <Coating> The coating 29 is a thin, almost porous film with bubbles crushed when the coating-forming member 120 is heated and melted. The thickness of the coating 29 is, for example, about 50 μm or more and less than 900 μm, and may be slightly uneven with a mixture of thin and slightly thick portions. Areas where the thickness is too thin may have holes, resulting in areas where the coating 29 is not present. The coating 29 contains a second resin material. The second resin material may be a thermoplastic resin or a thermosetting resin. Examples of thermoplastic resins include polyethylene, polypropylene, polystyrene, and polyvinyl chloride. Examples of thermosetting resins include polyurethane. Thinner portions of the coating 29 may contain a large amount of resin components that melt easily with heat, while thicker portions of the coating 29 may contain a large amount of components that do not melt easily with heat.

[0021] The first resin material of the foam substrate 10 may be polyurethane, and the second resin material of the coating 29 may be the same or different polyurethane as the first resin material. For example, the first resin material may be polyether-based polyurethane, and the second resin material may be polyether-based polyurethane or polyester-based polyurethane. Alternatively, the first resin material may be polyester-based polyurethane, and the second resin material may be polyether-based polyurethane or polyester-based polyurethane.

[0022] The foam substrate 10 may have a first color, and the coating 29 may have a second color that is the same as or different from the first color. Having the coating 29 a different color from the foam substrate 10 makes it easier to visually inspect the quality of the coating 29, for example. <Manufacturing method>

[0023] FIG. 4 shows a method for producing the film-coated foam substrate 1 according to one embodiment.

[0024] The press die 40 has a flat upper die 41 and a flat lower die 42 facing the upper die 41. The upper die 41 has a heater and is movable in the vertical direction. Examples of the heater include an electric heater and a hydraulic heater.

[0025] A foam substrate 10 and a film-forming member 120 are prepared. As described above, the foam substrate 10 contains a first resin material. The film-forming member 120 is a member for forming the film 29 and contains a second resin material. In this embodiment, the film-forming member 120 is a foamed body, but in other embodiments, a non-foamed body may be used.

[0026] The foam substrate 10 is placed on the lower mold 42. The film-forming member 120 is placed on the foam substrate 10. The heated upper mold 41 descends and presses against the foam substrate 10 and the film-forming member 120. The film-forming member 120 melts under the heat of the upper mold 41, and becomes a thin film 29 under the pressure of the upper mold 41. The upper mold 41 then ascends and cools and solidifies the film 29. In this way, the foam substrate 1 with a film is obtained.

[0027] The press die 40 may include a spacer disposed between the upper die 41 and the lower die 42. The amount of compression can be adjusted by the spacer.

[0028] In this way, the film-forming member 120 can be superimposed on at least one surface of the foaming substrate 10, and the film-forming member 120 can be melted. This allows the formation of a film 29 that is welded to at least one surface of the foaming substrate 10. Alternatively, the film-coated foaming substrate 1 may be formed by heating both the upper mold 41 and the lower mold 42 of the press mold 40, so that the film 29 is formed on both the top and bottom surfaces of the foaming substrate 10.

[0029] The film-forming member 120 has a heated surface 121 and an overlapping surface 122 opposite to the heated surface 121. The overlapping surface 122 is the surface that comes into contact with the foaming substrate 10. In this embodiment, the film-forming member 120, which is physically separated from the foaming substrate 10, is overlapped with the film-forming member 120, and the heated surface 121 of the film-forming member 120 is heated and melted to form the film 29.

[0030] The majority of the film 29 may be the second resin material melted from the heated surface 121 side of the film-forming member 120. Alternatively, the upper surface 91 of the foaming substrate 10 may also be heated by the heated and melted state, and the first resin material of the foaming substrate 10 may also melt, forming the film 29 together with the molten second resin material. Even in this case, the second resin material different from the first resin material is melted, and the film 29 is welded to at least one surface of the foaming substrate 10.

[0031] In this embodiment, the second resin material of the film-forming member 120 has the property of melting when heated. Furthermore, a flexible, soft foam is preferable because it has thermal melting properties and can be heated while applying pressure to the gap between the heating roll 50 or heating mold and the film-forming member 120. This allows the film-forming member 120 to be heated and the second resin material to melt, which then becomes flexible and elastically deformable by compression, allowing the molten material to approach the interface with the foam substrate 10. Furthermore, since the film-forming member 120 is a porous film-forming foam, the heated and melted second resin material is preferably extruded into the micropore spaces in the porous material by compression and can reach the foam substrate 10. The melted second resin material is then cooled and welded to the foam substrate 10. The cell membrane of the film-forming foam may or may not be removed.

[0032] The film 29 is formed by pressing the surface (heating surface 121 or overlapping surface 122) of the film-forming member 120 with a hot plate or hot roll to melt the surface of the film-forming member 120 and crush any air bubbles, resulting in a substantially porous state. The film-forming member 120 is mainly obtained by cutting a block-shaped slab foam, which is called a slab in the technical field of synthetic resin foam, into a sheet. The film-forming member 120 is obtained by cutting a film-forming foam into a sheet with a thickness of 0.3 to 20 mm, and then cutting this sheet to a specified width.

[0033] Examples of the thermoplastic resin foam for the film-forming member 120 include foams obtained from thermoplastic resins such as polyethylene, polypropylene, polystyrene, and polyvinyl chloride. Examples of the thermosetting resin foam for the film-forming member 120 include polyurethane foam. Further examples of the polyurethane foam include polyether-based polyurethane foams having ether groups in the polymer and polyester-based polyurethane foams having ester groups in the polymer. Polyurethane foams include semi-rigid polyurethane foams and flexible polyurethane foams, particularly flexible polyurethane foams that are highly flexible.

[0034] Polyurethane foam is a thermosetting resin that has crosslinks in its molecular structure due to the reaction between the main raw materials polyisocyanate and polyol. Polyurethane foam suitable for the film-forming member 120 preferably has a low crosslink density, which is the proportion of crosslinks in the molecular structure. From this perspective, semi-rigid and flexible polyurethane foams are more preferable than rigid polyurethane foams.

[0035] Furthermore, as a film-forming foam (film-forming member 120) that has excellent heat melting properties even when it has a crosslinked structure, a foam having an ester bond is preferable. Examples of foams having an ester bond include polyester-based polyurethane foams. Specific examples of polyester-based polyurethane foams include polyester-based polyurethane foams and polyetherester-based polyurethane foams produced by foaming a composition containing an ester-based polyol component. These foams are produced by using polyester polyol or polyether ester polyol as the polyol component in a polyurethane foam-producing composition.

[0036] Furthermore, foams having an ester bond include those obtained by foaming a composition containing raw materials such as an ester-based crosslinking agent, a chain extender, a plasticizer, a flame retardant, etc. Examples include polyester polyurethane foams and polyether polyurethane foams obtained by foaming a composition containing a crosslinking agent having an ester bond, a chain extender, a plasticizer, and a flame retardant in a polyester polyol or a polyether polyol.

[0037] Furthermore, foams having ester bonds include those in which compounds having ester bonds are reacted and bonded to the molecular structure, as well as those in which compounds having ester bonds are dispersed around polyurethane molecules without reacting. Specific examples include polyester polyurethane foams and polyether polyurethane foams produced by foaming compositions containing plasticizers having ester bonds and flame retardants that do not have reactive groups. Raw materials generally used in polyurethane foam production can be used as the raw materials for producing polyurethane foams.

[0038] FIG. 5 shows another embodiment in which a heated roll is used instead of the heat press mold in FIG. 4. The film-forming member 120, overlapping the foam substrate 10, is passed between heated rolls 50, and the surface of the film-forming member 120 is brought into contact with the heated roll 50 and pressed. The foam substrate 10 and film-forming member 120 may also pass between supply rolls (not shown) as needed. The surface of the film-forming member 120 in contact with the heated roll 50 is melted, and the molten second resin material reaches the foam substrate 10 under pressure and is fused to the foam substrate 10. When the heated roll 50 is then separated from the molten film, the molten film cools and solidifies to form the film 29. In this manner, a film-coated foam substrate 1 is continuously obtained.

[0039] In FIG. 5, both the upper and lower heating rolls 50 are heated, so that a film 29 can be formed on both the top and bottom surfaces of the foam substrate 10. The film-forming members 120 disposed on the top surface 91 or bottom surface 92 may be of the same type as the foam substrate 10, or may be different. If the film-forming members 120 are made of the same type of resin material as the foam substrate 10, a film 29 with the same properties as the foam substrate 10 is formed. If the film-forming members 120 are made of a different type of resin material than the foam substrate 10, a film 29 with different properties than the foam substrate 10 is formed. Although a heating roll 50 is used in FIG. 5, a heated metal piece such as a plate-shaped spatula may be used instead of the heating roll 50. When the lower roll in FIG. 5 is not heated, the lower roll simply serves as the pressure roll 55. In this case, the film-forming member 120 below the foam substrate 10 in FIG. 5 is not used. Therefore, the film-forming member 120 is placed only on the upper surface 91 of the foam substrate 10 and passes between the heating roll 50 and the pressure roll 55 while being pressed. The upper heating roll 50 heats the film-forming member 120. The surface of the film-forming member 120 in contact with the heating roll 50 is melted, and the molten second resin material reaches the foam substrate 10 by pressure and is welded to the upper surface of the foam substrate 10.

[0040] A coating can be formed on the outer peripheral surface 14 of the foaming substrate 10 as follows. First, the foaming substrate 10 in the shape of a prismatic column (rod, rectangular parallelepiped) is heated in a mold having heating surfaces arranged in parallel, and melted to form (press mold) the coating 29. Thereafter, the prismatic column is rotated, for example, by 90 degrees and heated again, so that the coating 29 can be formed in two or more places on the outer peripheral surface 14.

[0041] In another embodiment, two sets of heating rolls 50 can be arranged with their rotation axes intersecting to form a coating 29 over the entire outer peripheral surface 14 of the foaming substrate 10. An apparatus having a pair of heating rolls 50 with their rotation axes horizontally arranged and another pair of heating rolls 50 with their rotation axes vertically arranged may also be used. The film-forming member 120 superimposed on the foaming substrate 10 passes between the heating rolls 50 arranged on the horizontally arranged rotation axis 51. The foaming substrate 10 and the film-forming member 120 may pass through a supply roll as needed. The heating roll 50 contacts and presses against the surface of the film-forming member 120 superimposed on the foaming substrate 10. The surface of the film-forming member 120 in contact with the heating roll 50 is melted, and the molten second resin material reaches the foaming substrate 10 by pressure and is welded to the foaming substrate 10. Thereafter, when the horizontally arranged heating rolls 50 move away from the film-forming member 120, the molten second resin material cools and solidifies, and a molten film is continuously formed on the upper surface 14a and the lower surface 14b of the foaming substrate 10. Next, the pair of heating rolls 50, whose rotation axes are arranged vertically, heat and melt the left side surface 14d and the right side surface 14c of the foaming substrate 10, and a film 29 is formed over the entire outer peripheral surface 14.

[0042] 7, when the film-forming member 120 is superimposed on the upper surface 14a of the foam substrate 10, the continuous film-forming member 120 may be arranged so as to reach the right side surface 14c of the foam substrate 10. When the film-forming member 120 is superimposed on the foam substrate 10, separate, independent film-forming members 120 may be arranged on, for example, the left side surface 14d of the foam substrate 10. The size and coverage area of ​​the film-forming member 120 arranged on the foam substrate 10 are arbitrary. The leading end of the film-forming member 120 to be superimposed on the foam substrate 10 may be temporarily fixed at the interface with an adhesive, or may be tied with a string or the like before being transported to the heating roll 50.

[0043] This allows the coating 29 to be continuously formed on the upper surface 14a of the foaming substrate 10 and on the right surface 14c intersecting with the upper surface 14a. Of course, the coating 29 can also be continuously formed on the upper surface 14a of the foaming substrate 10, the opposing lower surface 14b, and the right surface 14c intersecting with the upper surface 14a. In this way, the coating 29 can be continuously formed on the outer peripheral surface 14 of the foaming substrate 10, and further, can be continuously formed over the entire outer peripheral surface 14 of the foaming substrate 10.

[0044] As shown in FIG. 6, the film 29 may be produced by heating an annular mold 60 having spaces (holes) therein and passing the foaming substrate 10 and the film-forming member 120 through the annular mold 60 .

[0045] The annular mold 60 is provided with an inlet 61 having a similar shape to or slightly larger than the cross-sectional shape of the foaming substrate 10 and the film-forming member 120 stacked together. Furthermore, a space (through hole) is provided with an outlet 62 having a shape similar to but smaller than the cross-sectional shape of the foaming substrate 10 and the film-forming member 120 stacked together. The annular mold 60 is also provided with a heater, which heats the inner wall surface temperature of the through hole of the annular mold 60 to a temperature close to the melting temperature of the film-forming member 120.

[0046] The film-forming member 120 is placed around the foam substrate 10, and these are introduced into the heated through-hole from the inlet 61 of the annular mold 60. As the film-forming member 120 passes through the through-hole, the surface of the film-forming member 120 becomes molten due to compression by the inner wall surface and the heat of the annular mold 60, and a molten second resin material is formed. Upon leaving the outlet 62 of the through-hole, the second resin material is cooled by the ambient temperature, and the molten film solidifies on the outer peripheral surface of the foam substrate 10, forming a film 29 over the entire outer peripheral surface 14 and welding it to the foam substrate 10.

[0047] Hereinafter, the heated press mold 40, the heated roll 50, and the heated annular mold 60 having through-holes will be referred to as the heated mold. The heating temperature of the heated mold may be selected appropriately depending on the type and size of the heated mold used, and the type (melting temperature), density, and thickness of the film-forming member 120. For flexible polyurethane foams, a temperature of 280°C to 450°C, and particularly preferably 330°C to 400°C, is appropriate.

[0048] <Example> The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0049] <Types of polyurethane foam> The following types of polyurethane foams are used: Malt filters are polyurethane foams from which the cell membrane has been removed. 1. Ester-based Product name: Malt Filter MF-8 (manufactured by Inoac Corporation, density: 30 kg / m 3 , Number of cells: 8 / 25mm, yellow) Product name: Malt Filter MF-13 (manufactured by Inoac Corporation, density: 30 kg / m 3 , Number of cells: 13 / 25mm, Black) Product name: Malt Filter MF-20 (manufactured by Inoac Corporation, density: 30 kg / m 3 , Number of cells: 20 / 25mm, black) Product name: Malt Filter MF-30 (manufactured by Inoac Corporation, density: 30 kg / m 3 , Number of cells: 30 / 25mm, black) Product name: Malt filter MF-13 (non-membrane type, manufactured by Inoac Corporation, density: 30 kg / m 3 , Number of cells: 13 / 25mm, Black) 2. Ether system Product name: Color Foam EL-62 (manufactured by INOAC Corporation, density: 24 kg / m 3 , Number of cells: 42 / 25mm (measured value, gray)

[0050] <Comparative Example 1> (Example of four coating surfaces) To produce a 50 mm square prismatic film-coated foam substrate 1, a square prismatic foam with a 10 mm melt margin on each side was prepared, with a 70 mm square base. The corners were linearly chamfered. The 70 mm square prismatic film was positioned so that its longitudinal direction was horizontal, passed between two heated rolls 50, and pressed against the heated rolls 50 (Figure 5). In this way, a film-coated foam substrate 1 was produced. The prismatic film was then rotated 90 degrees, with the sides not in contact with the heated rolls 50 facing upward and downward, and passed between the two heated rolls 50. The surface of the prismatic film was pressed against the heated rolls 50. A film-coated foam substrate 1 was produced, with a film 29 formed only on a portion of the entire periphery of the four sides of the yellow foam substrate 10. The production conditions were as follows. Foam substrate 10: Product name: Malt Filter MF-8 Film forming material 120: None Creation conditions: Heating temperature: 360°C, conveyor speed: 0.5m / min

[0051] The malt filter MF-8 had coarse cells, and the film 29 was only formed on a part of the outer peripheral surface 14, with most of it being perforated. This was because the cell spacing (skeleton spacing) of the malt filter MF-8 was wide, and the amount of resin was insufficient with a melting allowance of 10 mm, making it impossible to form the desired film 29. In addition, an octagonal prism with a square base of 70 mm on each side was used as the melting allowance, with each corner chamfered by a right triangle with one side of 10 mm, to obtain a product in the form of a regular square prism with a square base of 50 mm on each side. The product area of ​​the base of the prismatic prism was 2500 mm 2 On the other hand, 4700mm 2 The material required for the formation of the coating 29 is 2200 mm 2 The yield rate per unit length of the prism is 2500 / 4700 = 53%. -Base area of ​​the rectangular pillar: 2500mm 2 - Base area of ​​the rectangular pillar used: 4700mm 2 Yield rate per unit length: 53%

[0052] <Example 1> (Example of coating on one surface) A foam substrate 10 in the shape of a regular square pillar with a 50 mm square base was prepared. The longitudinal direction of the pillar (the height direction relative to the base) was placed horizontally, and a sheet-like film-forming member 120 with a width of 50 mm and a thickness of 5 mm was placed on the top surface of the pillar, and the base was passed between a heating roll 50 and a pressure roll 55 (FIG. 5). A heated roll 50 was brought into contact with and pressed against the surface of the coating forming member 120 to produce a coated foam substrate 1 in which a black coating 29 was formed on the upper surface of a gray foam substrate 10. The foam substrate 10 is an ether-based polyurethane foam, to which an ester-based polyurethane coating has been melted and solidified and welded. Foam substrate 10: Product name: Color Foam EL-62 Film forming material 120: Product name: Malt Filter MF-30 Creation conditions: Heating temperature: 360°C, conveyor speed: 0.5m / min -Base area of ​​the rectangular pillar: 2500mm 2 - Base area of ​​the rectangular pillar used: 2750mm 2 Yield rate per unit length: 91%

[0053] Example 2 (Example of two coating surfaces) A foam substrate 10 in the shape of a square pillar with a side length of 50 mm was placed horizontally, and sheet-like film-forming members 120 each having a width of 50 mm and a thickness of 5 mm were placed on the top and bottom surfaces of the foam substrate 10, and the sheet-like film-forming members 120 were passed between two heated rolls 50 (Fig. 5). A heated roll 50 was brought into contact with and pressed against the surface of the coating forming member 120 to produce a coated foam substrate 1 in which black coatings 29 were formed on the upper and lower surfaces of a gray foam substrate 10. The production conditions were the same as in Example 1. The foam substrate 10 was an ether-based polyurethane foam, to which an ester-based polyurethane coating 29 had been melted and solidified and welded. Foam substrate 10: Product name: Color Foam EL-62 Film forming material 120: Product name: Malt Filter MF-20 -Base area of ​​the rectangular pillar: 2500mm 2 - Base area of ​​the rectangular pillar used: 3000mm 2 Yield rate per unit length: 83%

[0054] Example 3 (Example of two coating surfaces) A foam substrate 10 in the shape of a square pillar with a length of 50 mm on each side was placed horizontally, and sheet-like film-forming members 120 each having a width of 50 mm and a thickness of 3 mm were placed on the top and bottom surfaces of the foam substrate 10, and the film-forming members 120 were passed between two heated rolls 50 (Fig. 5). A heated roll 50 was brought into contact with and pressed against the surface of the coating forming member 120 to produce a coated foam substrate 1 in which a gray coating 29 was formed on the upper and lower surfaces of a black foam substrate 10. The production conditions were the same as in Example 1. The foam substrate 10 was an ester-based polyurethane foam, to which an ether-based polyurethane coating had been melted and solidified and welded. Foam substrate 10: Product name: Malt Filter MF-13 Film forming material 120: Product Name: Color Foam EL-62 -Base area of ​​the rectangular pillar: 2500mm 2 - Base area of ​​the rectangular pillar used: 2800mm 2 Yield rate per unit length: 89%

[0055] Example 4 (Example of four coating surfaces) A foam substrate 10 in the shape of a regular square prism with a side length of 50 mm was placed horizontally, and sheet-like film-forming members 120 each having a width of 50 mm and a thickness of 7 mm were placed on the top and bottom surfaces of the foam substrate 10, and the foam substrate was passed between two heated rolls 50 (Fig. 5). A heated roll 50 was brought into contact with the surface of the film-forming member 120 and pressed against it to produce a film-coated foam substrate 1 in which a black film 29 was formed on the upper and lower surfaces of the yellow foam substrate 10. Furthermore, the orientation of the prismatic body was changed by 90 degrees so that the surfaces not in contact with the heated roll 50 became the upper and lower surfaces, and a sheet-like film-forming member 120 having a width of 50 mm and a thickness of 7 mm was placed on each of the upper and lower surfaces and passed between the two heated rolls 50. The surface of the film-forming member 120 was brought into contact with the heated roll 50 and pressed against it. A film-coated foam substrate 1 in which a uniform black film 29 was formed around the entire periphery of the four sides of the yellow foam substrate 10 was produced. The production conditions were the same as in Example 1. An ester-based polyurethane film was melted and solidified and welded to the foam substrate 10 made of ester-based polyurethane foam. In Comparative Example 1, in which the coating 29 was formed on all four sides of the foam substrate 10, the yield rate was 53%, whereas in Example 4, the yield rate was 64%, which was excellent, and the desired coating 29 was formed. Foam substrate 10: Product name: Malt Filter MF-8 Film forming material 120: Product name: Malt Filter MF-13 -Base area of ​​the rectangular pillar: 2500mm 2 - Base area of ​​the rectangular pillar used: 3900mm 2 Yield rate per unit length: 64%

[0056] <Example 5> (Example with four coating surfaces) The film-forming member 120 was MF-20 and had a thickness of 5 mm, and the other conditions were the same as in Example 4. A foam substrate 10 in the shape of a square prism with a 50 mm side was placed with its longitudinal direction horizontal, and sheet-like film-forming members 120 with a width of 50 mm and a thickness of 5 mm were placed on the top and bottom surfaces of the foam substrate 10, and the film-forming members 120 were passed between two heated rolls 50 ( FIG. 5 ). Next, as in Example 4, the orientation of the prism was changed by 90 degrees, and the sheet-like film-forming members 120 with a width of 50 mm and a thickness of 5 mm were placed on top of each other. The prism was then brought into contact with the heated roll 50 and pressed. A film-coated foam substrate 1 was produced in which a uniform black film 29 was formed on all four sides of a yellow foam substrate 10. The production conditions were the same as in Example 1. An ester-based polyurethane film was melted and solidified and welded to the foam substrate 10 made of ester-based polyurethane foam. In Comparative Example 1, in which the coating 29 was formed on the four peripheral surfaces of the foam substrate 10, the yield rate was 51%, whereas in Example 5, the yield rate was 71%, which was excellent, and the desired coating 29 was formed. Foam substrate 10: Product name: Malt Filter MF-8 Film forming material 120: Product name: Malt Filter MF-20 -Base area of ​​the rectangular pillar: 2500mm 2 - Base area of ​​the rectangular pillar used: 3500mm 2 Yield rate per unit length: 71%

[0057] Example 6 (Example of two coating surfaces) A foam substrate 10 in the shape of a square pillar with a side length of 50 mm was placed horizontally, and sheet-like film-forming members 120 each having a width of 50 mm and a thickness of 5 mm were placed on the top and bottom surfaces of the foam substrate 10, and the sheet-like film-forming members 120 were passed between two heated rolls 50 (Fig. 5). A heated roll 50 was brought into contact with and pressed against the surface of the coating forming member 120 to produce a coated foam substrate 1 in which a uniform black coating 29 was formed on the upper and lower surfaces of the black foam substrate 10. The production conditions were the same as in Example 1. The foam substrate 10 was an ester-based polyurethane foam with a non-removed coating, and the ester-based polyurethane coating was melted, solidified, and welded. Foam substrate 10: Product name: Malt filter MF-13 (non-membrane-removed) Film forming material 120: Product name: Malt Filter MF-13 -Base area of ​​the rectangular pillar: 2500mm 2 - Base area of ​​the rectangular pillar used: 3000mm 2 Yield rate per unit length: 83%

[0058] As described above, in each example, the coating 29 is formed on the foam substrate 10 using different resin materials, each having a different cell count for the foam substrate 10 and the coating-forming member 120. A coating-forming member 120 with a larger cell count than the foam substrate 10 (a foam with a finer cell size) can be used, facilitating the formation of the coating 29. According to the present invention, even when manufacturing a ceramic filter substrate with a small cell count and a coarse cell size for the foam substrate 10, a resin foam with a large cell count and a finer cell size can be used as the coating-forming member 120. This allows the thickness of the coating-forming member 120 to be reduced, improving yield and eliminating the need to chamfer the corners of the foam substrate 10, thereby improving productivity. These coating-coated foam substrates 1 can be used as substrates for manufacturing ceramic filters.

[0059] By adopting the present invention, it is possible to use separate foams in which the foam substrate 10 and the film-forming member 120 are physically separated, for example, foams with different densities, cell numbers (cell sizes), hardness, breathability, whether or not the film is removed, color, etc. This allows the thickness, type, properties, etc. of the film 29 to be changed, resulting in a wide variety of products. For example, by using a polyester foam for the foam substrate 10 and an ether foam for the film-forming member 120, the hydrolysis resistance of the film 29 itself can be improved compared to an ester film. By using a polyether foam for the foam substrate 10 and an ester foam for the film-forming member 120, the mechanical strength of the film 29 itself can be improved compared to an ether film. By changing the colors of the foam substrate 10 and the film-forming member 120, the quality and appearance of the film 29 formed and the manufacturing process can be more easily managed compared to conventional products in which the film 29 is formed using a single material. Furthermore, physically separating the waste material of the same type of foam after cutting the product into the foam substrate 10 and the film-forming member 120 is also beneficial from a recycling perspective.

[0060] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the examples described in this specification can be arbitrarily combined as necessary. [Explanation of symbols]

[0061] 1: Foam substrate with film 10: Foam base material 11: 1st surface, 12: 2nd surface, 14: Outer surface, 14a: Top side, 14b: Bottom side, 14c: Right side, 14d: Left side 29: Membrane 40: Press die, 41: Upper die, 42: Lower die 50: Heating roll, 51: Horizontally arranged rotating shaft, 55: Pressure roll 60: Annular mold, 61: Inlet, 62: Outlet 91: Top surface, 92: Bottom surface, 94: End surface 120: film forming member, 121: heating surface, 122: overlapping surface

Claims

1. a foam substrate containing a first resin material; a coating including a second resin material different from the first resin material and formed by welding to at least one surface of the foam base material; A film-coated foam substrate comprising:

2. The foam substrate includes a first surface, a second surface opposite to the first surface, and an outer circumferential surface connected between the first surface and the second surface, The coating is formed on the entire outer peripheral surface of the foam substrate. The film-coated foam substrate according to claim 1 .

3. the first resin material is polyurethane; The film-coated foam substrate according to claim 1 , wherein the second resin material is a polyurethane different from the first resin material.

4. The film-coated foam substrate according to any one of claims 1 to 3, wherein the film-coated foam substrate is a substrate for producing a ceramic filter.

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