Shock absorbing floor material

Abstract

To provide a shock absorbing floor material superior in load resistance, while having an absorbing effect by a soft layer.SOLUTION: The shock-absorbing floor material includes an upper floor material, an underfloor material provided below the upper floor material, and an intermediate material provided between the upper floor material and the underfloor material, wherein the underfloor material is formed of a resin material and has a foamed structure, the intermediate material is formed of a material containing a thermoplastic resin and an inorganic filler, and a strain (ε (σ max)) at which a bending strength becomes maximum in a three point bending test according to JISK7074 is 0.5% or more and a bending modulus of elasticity is 1 GPa or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to impact absorbing flooring. [Background technology]

[0002] Falls and fractures account for 10% of the reasons why elderly people require nursing care. Femoral fractures, the risk of which increases with age, require long-term hospitalization and can easily lead to elderly people becoming bedridden or developing dementia, resulting in a state of needing nursing care. For this reason, flooring materials have been proposed that reduce the risk of fractures by absorbing the impact on the femur when a pedestrian falls (for example, Patent Documents 1 and 2). Such flooring materials often have shock-absorbing properties achieved by foaming the flooring material itself or by providing a soft member such as a foam resin sheet on the back side of the flooring material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3600726 [Patent Document 2] Patent No. 5244927 Summary of the Invention [Problem to be solved by the invention]

[0004] However, such flooring materials have the problem that when heavy objects with casters, such as electrically operated nursing care beds or food delivery carts, are moved, the soft layer is crushed and dents are formed. The present disclosure has been made in view of such problems, and aims to provide an impact-absorbing flooring material that has excellent load-bearing capacity while retaining the impact-absorbing effect of a soft layer. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, one embodiment of the flooring material of the present disclosure comprises a top-floor material, a sub-floor material provided below the top-floor material, and an intermediate material provided between the top-floor material and the sub-floor material, wherein the sub-floor material is formed from a resin material and has a foam structure, and the intermediate material is formed from a material containing a thermoplastic resin and an inorganic filler, and has a strain (ε(σmax)) at which the bending strength is maximized in a three-point bending test according to JIS K7074 of 0.5% or more, and a bending modulus of elasticity of 1 GPa or more. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide an impact-absorbing flooring material that has excellent load-bearing capacity while still providing the impact-absorbing effect of the soft layer. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing an example of the configuration of a flooring material according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram for explaining a measuring device for measuring the impact absorption properties of flooring materials according to the first embodiment of the present disclosure. [Figure 3] 10A to 10C are a plan view, a cross-sectional view, and an enlarged view showing an example of the configuration of a flooring material according to a second embodiment of the present disclosure. [Figure 4] 1A and 1B are a plan view and a cross-sectional view showing a more detailed configuration of a base panel used in a flooring material according to a second embodiment of the present disclosure, and a cross-sectional view showing the configuration of a flooring material using the base panel. [Figure 5] FIG. 10 is a plan view showing another configuration of a base panel used in a flooring material according to a second embodiment of the present disclosure. [Figure 6] 1A and 1B are a plan view and a cross-sectional view showing the configuration of a sample used in load-bearing capacity evaluation in Examples 5 to 7 of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the embodiments described below exemplify devices and methods for embodying the technical ideas of the present disclosure. Furthermore, the technical ideas of the present disclosure can be modified in various ways within the technical scope described in the claims.

[0009] 1. First embodiment The impact-absorbing floor material according to the first embodiment of the present disclosure will be described below.

[0010] (1.1) Basic structure of impact-absorbing flooring Hereinafter, with reference to FIG. 1, an impact-absorbing floor material (hereinafter referred to as floor material) 1 according to the present disclosure will be described. The flooring material 1 comprises a top floor material 11, a subfloor material 12 provided below the top floor material 11 (the surface to which the flooring material 1 is attached), and an intermediate material 13 provided between the top floor material 11 and the subfloor material 12.

[0011] The floor covering 11 has surface functions such as improving the scratch resistance and stain resistance of the flooring material 1 and imparting design features to the flooring material 1. The underfloor material 12 has the function of absorbing pressure when a user falls and increasing the cushioning properties of the floor material 1. The intermediate material 13 serves as a support layer to distribute the load applied from the upper floor material 11 to the underfloor material 12, thereby improving shock absorption and load resistance.

[0012] The total thickness of the flooring material 1 is preferably more than 7 mm and not more than 25 mm. If the total thickness of the flooring material 1 exceeds 7 mm, it becomes easier to balance shock absorption, walking comfort, and durability. Also, if the total thickness of the flooring material 1 is 25 mm or less, the thickness of the flooring material 1 will not be too large, so the difference in height between the flooring material 1 and the non-installed part will not be too large, and the flooring material 1 will fit well during installation. The overfloor material 11, underfloor material 12 and intermediate material 13 will be described in detail below.

[0013] <Floor materials> The overfloor material 11 is a layer that forms the surface of the floor material 1, and is made of a harder material than the underfloor material 12. The thickness of the floor covering material 11 is preferably 5 mm or less. By making the thickness of the floor covering material 11 5 mm or less, the weight of the floor covering material 1 does not become too heavy, and the burden during construction can be reduced.

[0014] Common materials such as long vinyl chloride sheets or vinyl chloride tiles can be used for the floor covering material 11. Methods for laminating the floor covering material 11 and the intermediate material 13 include adhesion using adhesive tape or glue. The floor covering material 11 may be laminated to the intermediate material 13 by thermal lamination in a process subsequent to the manufacturing process of the intermediate material 13.

[0015] <Underfloor materials> The underfloor material 12 is provided below the overfloor material 11 (on the opposite side to the surface of the overfloor material 11). The underfloor material 12 is made of a softer material than the overfloor material 11, and has the function of absorbing impacts on the floor material 1 by deforming appropriately in the event of a fall. The underfloor material 12 has a foam structure formed by methods such as chemical foaming, physical foaming, or supercritical foaming. The resin foam structure may be either a closed-cell foam structure or an open-cell foam structure.

[0016] The floor underlayment material 12 having a foam structure is formed from a thermoplastic resin such as polyethylene, polypropylene, polyvinyl chloride, ethylene vinyl acetate copolymer, polystyrene, polyurethane, or other resin.

[0017] The Asker C hardness of the underfloor material 12 is preferably 25 or more and 60 or less. Here, "Asker C" is a measuring instrument for measuring hardness, and is one of the durometers (spring-type hardness testers) specified in SRIS0101 (Japan Rubber Association Standard). In other words, "Asker C hardness" refers to a value measured using the above-mentioned Asker C hardness tester. If the Asker C hardness of the underfloor material 12 is 25 or more and 60 or less, the impact absorption properties of the floor material 1 can be easily ensured, and discomfort when walking on the floor material 1 is also reduced.

[0018] The thickness of the underfloor material 12 is preferably 4 mm or more and 15 mm or less. If the thickness is 4 mm or more and 15 mm or less, it becomes easier to ensure shock absorption and load resistance, and also makes it less likely that discomfort will occur when walking.

[0019] <Intermediate material> Intermediate material 13 has appropriate mechanical properties (bending stress-strain characteristics), and is a layer that undergoes minimal deformation during normal use, but deforms appropriately when a large impact such as a fall is applied, dispersing the impact that the human body receives from the floor surface. In other words, intermediate material 13 has the function of improving the impact absorption and load-bearing capacity of flooring material 1.

[0020] The intermediate material 13 having such mechanical properties is formed from a material containing a thermoplastic resin and an inorganic filler. A composite of a thermoplastic resin and an inorganic filler is preferably used as the intermediate material 13. The intermediate material 13 can be obtained, for example, by molding a masterbatch, which is a mixture of a resin material and an inorganic filler, into a plate shape using a T-die extruder. Examples of thermoplastic resins that can be used include polyethylene, polypropylene, and polyvinyl chloride. Examples of inorganic fillers that can be used include calcium carbonate, calcium silicate, mica, talc, and glass fiber. The use of mica, talc, and glass fiber is preferred. This is because the flooring material 1 can have higher load-bearing capacity with the same amount of inorganic filler. The inorganic filler preferably has a scaly, plate-like, or fibrous shape. By using such an inorganic filler, better mechanical properties (bending stress-strain properties) can be obtained, and the load-bearing capacity can be further improved. The intermediate material 13 has a foam structure such as closed or open cells formed by methods such as chemical foaming, physical foaming, or supercritical foaming in order to improve the impact absorption effect of the flooring material 1. The intermediate material 13 having a foam structure can also reduce the weight of the flooring material 1, improving workability during installation of the flooring material 1.

[0021] The thickness of the intermediate material 13 is preferably 2 mm or more and 8 mm or less. By making the thickness 2 mm or more and 8 mm or less, the necessary shock absorption and load resistance are obtained, and the intermediate material 13 is not too heavy, so that problems with workability during installation are unlikely to occur.

[0022] The intermediate material 13 has appropriate mechanical properties (bending stress-strain characteristics) such that the strain (ε(σmax)) at which the bending strength is maximized in a three-point bending test according to JIS K7074 is 0.5% or more, preferably 0.5% or more, and the bending modulus is 1 GPa or more. If the above-mentioned strain ε(σmax) of the intermediate material 13 is less than 0.5% or the flexural modulus is less than 1 GPa, the intermediate material 13 is likely to be damaged, such as cracked or broken, when a large load is applied to the flooring material 1, and the impact absorption ability of the damaged area may decrease. In addition, the appearance of the flooring material 1 may become irregular or have other appearance abnormalities.

[0023] Furthermore, the distortion (ε(σmax)) of the intermediate material 13 is preferably 3% or more, and more preferably 6% or more. When the distortion (ε(σmax)) of the intermediate material 13 is 3% or more, the load-bearing capacity of the floor material 1 against a large load (for example, 100 kg) is improved, and when it is 6% or more, the load-bearing capacity of the floor material 1 against a large load (for example, 100 kg) is further improved. Furthermore, the flexural modulus of the intermediate material 13 is preferably 15 GPa or less. When the flexural modulus of the intermediate material 13 is 15 GPa or less, when a large load is applied to the flooring material 1 and an impact is applied to the flooring material 1, the load is effectively dispersed, and the cushioning effect of the flooring material 1 is further improved.

[0024] <Method for evaluating the impact absorption of flooring materials> A method for evaluating the impact absorption of flooring material 1 will be described with reference to Figure 2. The impact absorption of the flooring material is evaluated by the "impact load F," which is a simulated measurement of the impact load applied to the femur when a person falls on the flooring material. The impact load F is measured by the method described in JP 2020-76764 A.

[0025] The impact load is measured using an impact load measuring device 200 shown in Fig. 2. The impact load measuring device 200 includes a measurement table 210, an impact applying body 220, a buffer material 230, and a load measuring means 240. It should be noted that the floor material 1 shown in FIG. 2 is an object to be measured for impact load using the impact load measuring device 200, and is not a part that constitutes the impact load measuring device 200.

[0026] Impactor 220 has weight 221 and hitting portion 222. Weight 221 has a mass based on the pressure distribution applied to the trochanter of the femur due to a simulated fall. Hitting portion 222 is formed in a shape that simulates the trochanter of the femur. The cushioning material 230 is made of a material that mimics the soft tissue of the human body. The load measuring means 240 is a device that measures the force applied to the buffer material 230 when the impact applying body 220 is dropped onto the buffer material 230, and is, for example, a load cell.

[0027] When measuring the impact absorption of a flooring material, the flooring material 1 to be measured is placed between the buffer material 230 and the load measuring means 240, as shown in FIG. With the floor material 1 placed between the load measuring means (load cell) 240 placed on the measurement table 210 and the buffer material 230, the load measuring means 240 measures the change over time in the force applied to the buffer material 230 when the impact applying body 220 is dropped onto the buffer material 230 from a predetermined height corresponding to the height of the fall to be simulated. At this time, the load measuring means 240 measures the change over time in the force applied by the impact applying body 220 to the buffer material 230 from the time the impact applying body 220 comes into contact with the buffer material 230 until it stops, and the maximum value of the measured load is taken as the impact load F. At this time, the drop height of the impact applying body 220 is set so that the impact load (standard impact load Fs) when impact is applied only to the buffer material 230 is 5600 N, in order to simulate the impact on the femur during an actual fall.

[0028] Under the above conditions, the impact load F on the flooring material 1 is preferably 5000 N or less, and more preferably 3440 N or less. If the impact load exceeds 5000 N, the risk of femur fracture in elderly people becomes significant.

[0029] <Effects of the flooring material according to the present disclosure> The flooring material according to the present disclosure described above has the following effects. (1) The flooring material disclosed herein comprises a top-floor material, a sub-floor material provided below the top-floor material, and an intermediate material provided between the top-floor material and the sub-floor material, the sub-floor material being formed from a resin material and having a foam structure, and the intermediate material being formed from a material containing a thermoplastic resin and an inorganic filler, and having a strain (ε(σmax)) at which the bending strength is maximized in a three-point bending test according to JIS K7074 of 0.5% or more and a bending modulus of elasticity of 1 GPa or more. This allows the flooring material to have excellent load-bearing capacity while still providing the absorption effect of the soft layer.

[0030] (2) In the flooring material according to the present disclosure, the inorganic filler contained in the intermediate material may have a flaky, plate-like, or fibrous shape. This provides the flooring with better mechanical properties (bending stress-strain characteristics) and improved load-bearing capacity.

[0031] (3) In the flooring material according to the present disclosure, the above-mentioned strain ε(σmax) of the intermediate material may be 3% or more. This further improves both the impact absorption and load-bearing capacity of the flooring material.

[0032] 2. Second embodiment The impact-absorbing floor material according to the second embodiment of the present disclosure will be described below. The impact-absorbing floor material according to the second embodiment is composed of a plurality of base panels and a floor covering that covers the base panels. The shock-absorbing floor material according to the second embodiment will be described in detail below with reference to FIG.

[0033] (2.1) Basic structure of impact-absorbing flooring Hereinafter, the shock-absorbing flooring material (hereinafter referred to as the flooring material) 2 according to this embodiment will be described with reference to FIGS. 3(A) to 3(C) and 4(A) to 4(C). FIG. 3(A) is a plan view showing the configuration of the flooring material 2, with the floor covering material 11 of the flooring material 2 omitted. FIG. 3(B) is a cross-sectional view showing the cross-sectional configuration of the flooring material 2, showing the AA cross-section in FIG. 3(A). FIG. 3(C) is an enlarged view showing one intermediate material 13 and its surrounding area of ​​the flooring material 2 shown in FIG. 3(A). FIG. 4(A) is a plan view showing the configuration of the base panel 14 constituting the flooring material 2, FIG. 4(B) is a cross-sectional view showing the cross-sectional configuration of the base panel 14 constituting the flooring material 2, and FIG. 4(C) is a cross-sectional view showing the cross-sectional configuration of the flooring material 2. The base panels 14 shown in FIG. 4 are, as an example, two panels out of the multiple base panels 14 constituting the flooring material 2.

[0034] As shown in Figures 3(A) and 3(B), the flooring material 2 comprises a top flooring material 11 and a plurality of base panels 14 provided below the top flooring material 11 (the surface to which the flooring material 2 is attached). The base panel 14 is a laminated body in which a subfloor material 12 and an intermediate material 13 are stacked. The base panels 14 are arranged, for example, in a matrix pattern on the surface to which the flooring material 2 is attached. The base panels 14 are arranged so that the subfloor material 12 faces the surface to which the flooring material 2 is attached and the intermediate material 13 faces the top flooring material 11.

[0035] Here, the floor covering 11 has the same components as the floor covering 1 described in the first embodiment, and therefore a description thereof will be omitted. The substrate panel 14, which is composed of the underfloor material 12 and the intermediate material 13, will be described below.

[0036] <Base panel> As described above, the base panel 14 is a laminate formed by stacking the rectangular intermediate material 13 and the rectangular underfloor material 12. In each of the base panels 14, the outer periphery of the intermediate material 13 overlaps the outer periphery of the underfloor material 12 by two sides or less in a plan view. As shown in Figure 4(A), the intermediate material 13 of the base panel 14 is rectangular and has four sides 131 to 134 that form the periphery of the intermediate material 13. Similarly, the underfloor material 12 of the base panel 14 is rectangular and has four sides 121 to 124 that form the periphery of the underfloor material 12. Of the four sides of the underfloor material 12, the side that is positioned corresponding to side 131 of the intermediate material 13 is side 121, the side that is positioned corresponding to side 132 of the intermediate material 13 is side 122, the side that is positioned corresponding to side 133 of the intermediate material 13 is side 123, and the side that is positioned corresponding to side 134 of the intermediate material 13 is side 124.

[0037] In base panel 14, which is a laminate of intermediate material 13 and underfloor material 12, it is preferable that sides 131-134 forming the periphery of intermediate material 13 and sides 121-124 forming the periphery of underfloor material 12 overlap by no more than two sides in a plan view. Fig. 3(A) shows a configuration example in which sides 131-134 forming the periphery of intermediate material 13 and sides 121-124 forming the periphery of underfloor material 12 overlap by zero in a plan view. 5(A), the base panel 14 of the flooring material 2 may be configured such that the underfloor material 12 and intermediate material 13 of the same shape are stacked with a misalignment in only one direction. That is, the base panel 14 of the flooring material 2 shown in FIG. 5(A) shows a configuration example in which the sides 131-134 forming the periphery of the intermediate material 13 and the sides 121-124 forming the periphery of the underfloor material 12 overlap on two sides in a plan view (sides 122 and 132, and sides 124 and 134). 5(B) and 5(C), the flooring material 2 may include some base panels 14 in which the sides 131-134 forming the periphery of the intermediate material 13 overlap the sides 121-124 forming the periphery of the underfloor material 12 by more than two sides in a plan view. For example, as shown in FIGS. 5(B) and 5(C), base panels 14 in which the sides 131-134 forming the periphery of the intermediate material 13 overlap the sides 121-124 forming the periphery of the underfloor material 12 by more than two sides in a plan view may be arranged at positions that are the ends of the flooring material 2 (the periphery of the flooring material 2), and base panels 14 in which the sides 131-134 forming the periphery of the intermediate material 13 overlap the sides 121-124 forming the periphery of the underfloor material 12 by two sides or less in a plan view may be arranged at positions other than the ends of the flooring material 2.

[0038] The distance L1 (offset amount) in a plan view between the side 131 of the intermediate material 13 and the side 121 of the underfloor material 12 facing the side 131 of the intermediate material 13 can be determined as appropriate, but is preferably 20 mm or more. Similarly, the distance L2 in a plan view between the side 132 of the intermediate material 13 and the side 122 of the underfloor material 12, the distance L3 in a plan view between the side 133 of the intermediate material 13 and the side 123 of the underfloor material 12, and the distance L4 in a plan view between the side 134 of the intermediate material 13 and the side 124 of the underfloor material 12 are also preferably 20 mm or more. By having the distances L1 to L4 be 20 mm or more, good load-bearing properties are achieved, particularly when a large load of 100 kg or more is applied.

[0039] <Effects of the flooring material according to the present disclosure> The flooring material according to this embodiment described above has the following advantages in addition to the advantages (1) to (3) of the first embodiment. (4) The flooring material according to the present disclosure is composed of a plurality of base panels and the floor covering material covering the base panels, and the base panels are laminated bodies in which the rectangular intermediate material and the rectangular underfloor material are stacked, and it is preferable that in each of the base panels, the overlap between the outer periphery of the intermediate material and the outer periphery of the underfloor material in a plan view is two sides or less. This prevents deformation of the outer periphery of the intermediate material even when a load is applied to the base panel, improving the load-bearing capacity of the flooring material. (5) In the flooring material according to the present disclosure, it is preferable that the distance between one side of the intermediate material and one side of the floor underlayment material opposite to the one side of the intermediate material in a plan view of the base panel is 0 mm or more. This improves load-bearing capacity, especially when a large load of 100 kg or more is applied. [Example]

[0040] The flooring material according to the present disclosure will be described below with reference to examples, but the flooring material according to the present disclosure is not limited to these examples.

[0041] Example 1 The underfloor material was polyethylene foam (Asker C hardness 45, dimensions 600mm x 600mm x 6mm thick), the intermediate material was a rigid polyvinyl chloride resin board (containing 70wt% irregular calcium carbonate, ε (σmax) 0.9%, flexural modulus 8GPa, dimensions 600mm x 600mm x 4mm thick), and the top-floor material was a long polyvinyl chloride resin sheet (dimensions 600mm x 600mm x 2mm thick). The underfloor material, intermediate material, and top-floor material were laminated in this order using an adhesive to form the impact-absorbing flooring material of Example 1. Here, ε (σmax) is the strain (unit: %) at which bending strength is maximized in a three-point bending test according to JIS K7074.

[0042] <Example 2> The impact-absorbing flooring material of Example 2 was prepared in the same manner as Example 1, except that a hard polyvinyl chloride resin board (containing 35 wt% of irregularly shaped calcium carbonate, ε (σ max) 2%, flexural modulus 1.2 GPa, dimensions 600 mm × 600 mm × thickness 4 mm) with a varying content of inorganic filler was used as the intermediate material.

[0043] Example 3 The impact-absorbing flooring material of Example 3 was formed in the same manner as Example 1, except that a hard polyvinyl chloride resin board (containing 70 wt% of scaly mica, ε (σmax) 3%, flexural modulus of elasticity 12 GPa, dimensions 600 mm x 600 mm x thickness 4 mm) with different inorganic filler materials and contents was used as the intermediate material.

[0044] Example 4 The impact-absorbing flooring material of Example 4 was formed in the same manner as Example 1, except that a hard polyvinyl chloride resin board (containing 35 wt% of scaly mica, ε (σmax) 6%, flexural modulus 4 GPa, dimensions 600 mm x 600 mm x thickness 4 mm) with different inorganic filler materials and contents was used as the intermediate material.

[0045] <Example 5> The dimensions of the underfloor material were two types, (600mm x 315mm) and (600mm x 285mm), the dimensions of the intermediate material and the top floor material were (600mm x 300mm), and the top floor material was adhered to the base panel obtained by adhering the underfloor material and the intermediate material as shown in Figure 4. Except for this, the impact-absorbing floor material (2 pieces) of Example 5 was formed in the same manner as Example 1.

[0046] Example 6 Two shock-absorbing floor materials of Example 6 were formed in the same manner as in Example 5, except that the dimensions of the underfloor material were two types: (600 mm x 325 mm) and (600 mm x 275 mm).

[0047] Example 7 The same procedure as in Example 5 was carried out except that the dimensions of the floor underlayment were changed to two types: (600 mm x 350 mm) and (600 mm x 250 mm). Two impact-absorbing floor materials of Example 7 were prepared.

[0048] <Comparative Example 1> The impact-absorbing flooring material of Comparative Example 1 was prepared in the same manner as in Example 1, except that a hard polyvinyl chloride resin board (containing 80 wt% irregular calcium carbonate, ε (σmax) 0.4%, flexural modulus 10 GPa, dimensions 600 mm × 600 mm × thickness 4 mm) with a varying inorganic filler content was used as the intermediate material.

[0049] <Comparative Example 2> The impact-absorbing flooring material of Comparative Example 2 was prepared in the same manner as in Example 1, except that a hard polyvinyl chloride resin board (containing 30 wt% irregular calcium carbonate, ε (σmax) 2%, flexural modulus 0.5 GPa, dimensions 600 mm × 600 mm × thickness 4 mm) with a varying inorganic filler content was used as the intermediate material.

[0050] <Comparative Example 3> An impact-absorbing floor material of Comparative Example 3 was formed in the same manner as in Example 1, except that a urethane rubber plate (Asker C hardness 45, dimensions 600 mm x 600 mm x thickness 6 mm) was used as the floor underlayment material.

[0051] [evaluation] (load-bearing capacity) The impact-absorbing flooring materials of Examples 1 to 4 and the Comparative Example were cut into rectangles of 300mm x 600mm, and two pieces of the cut impact-absorbing flooring materials were prepared. These impact-absorbing flooring materials were then laid out and glued on a slate board (600mm x 600mm, 10mm thick) to prepare test specimens. Furthermore, a shock-absorbing floor material (600mm x 600mm) formed using two types of base panels from Examples 5 to 7 was placed on a slate board (600mm x 600mm, thickness 10mm) and bonded to form a test specimen. As shown in Fig. 6, the test specimens formed in Examples 5 to 7 have a thickness in which a base panel 14, which is made of a floor underlayment material 12 and an intermediate material 13, and a floor top material 11 are layered on a slate board 100. At this time, the distance L5 (offset amount, see FIG. 4(C)) between the portions where the intermediate materials contact each other and the portions where the underfloor materials contact each other in the test specimens of Examples 5 to 7 was 25 mm in Example 5, 15 mm in Example 6, and 50 mm in Example 7. Furthermore, in the test specimens of Examples 5 to 7, the distance between the portions where the intermediate materials contact each other and the portions where the underfloor materials contact each other on the periphery of the test specimen was 0 around the entire periphery. The load-bearing capacity was evaluated based on the appearance of the floor material and intermediate material after the caster test for each test specimen. The caster test conditions were as follows: Caster test conditions The test was conducted using the A-2 method for caster durability testing in accordance with JIS 1454:2016, with loads of 50 kg and 100 kg and a test time of 3 hours. The 50 kg load is assumed to be the load per wheel of an electric bed, and the 100 kg load is assumed to be the load per wheel of a food delivery cart. Evaluation criteria The evaluation criteria for the caster tests with loads of 50 kg and 100 kg were as follows: Slight to no change in appearance of flooring and intermediate materials: ○ Moderate changes in appearance of flooring or intermediate materials: △ Significant changes in appearance of flooring or intermediate material: ×

[0052] (shock absorption) The impact-absorbing flooring materials of each example and comparative example were cut into 100 mm squares to prepare test specimens, and the impact load F (unit: N) was measured using the method described in JP 2020-076764 A using an impact load measuring device 100 shown in Figure 2. The impact load measuring device had the following specifications. Measurement conditions Load cell: "TCLU-5A" manufactured by Tokyo Measuring Instruments Laboratory Co., Ltd. Accelerometer: Showa Sokki Co., Ltd. Digital Shock and Vibration Accelerometer "1340B" Measuring table: Surface plate size 750mm x 1000mm x 125mm, weight 185kg Weight body: Material: Stainless steel Striking part: Material: Stainless steel, machined, radius of curvature: 100 mm Impactor: Weight Sw 5.85 kg (including accelerometer) Cushioning material: "Human Skin Gel" (product name) manufactured by Exseal Co., Ltd., thickness 20 mm, Asker C hardness 7, Young's modulus 0.22 MPa Evaluation criteria Less than 3500N (low risk of fracture in elderly): 3500N or more but less than 5000N (elderly people at risk of fracture): △ Over 5000N (high risk of fractures in the elderly): × ·Judgment criteria ○ or △: Pass ×: Fail

[0053] Table 1 below shows the evaluation results of each of the examples and comparative examples.

[0054] [Table 1]

[0055] As shown in Table 1, the impact-absorbing flooring materials of Examples 1 to 4, which comprised a top-floor material, an under-floor material, and an intermediate material, in which the under-floor material had a foam structure and the intermediate material contained an inorganic filler, and in which the strain (ε(σmax)) at which the bending strength was maximized in a three-point bending test according to JIS K7074 was 0.5% or more and the bending modulus was 1 GPa or more, had good impact absorption. Furthermore, the impact-absorbing flooring materials of Examples 1 to 4 described above had good load-bearing properties when subjected to a load of 50 kg. Furthermore, the impact-absorbing flooring materials of Examples 2 to 4, in which the above-mentioned distortion (ε(σmax)) is 2% or more, also have good load-bearing properties when subjected to a load of 100 kg, and the impact-absorbing flooring materials of Examples 3 and 4, in which the above-mentioned distortion (ε(σmax)) is 3% or more, have even better impact absorption properties. Furthermore, in the impact-absorbing floor material of Example 4, in which the above-mentioned distortion (ε(σmax)) is 6% or more, there was little to no change in the appearance of the floor material and intermediate material, and the load-bearing capacity when subjected to a load of 100 kg was also good, at less than 3500 N.

[0056] Furthermore, in the impact-absorbing floor materials of Examples 5 to 7, in which a distance L5 was set between line A relating to the intermediate material and line B relating to the floor underlayment material in the test specimen for the load-bearing test, Example 5 (distance L5 = 15 mm) had the same load-bearing capacity as Example 1, but Example 6 (distance L5 = 25 mm) showed improved load-bearing capacity, and Example 7 (distance L5 = 50 mm) was equivalent to Example 6.

[0057] The test specimens of Examples 5 to 7 are part of an impact-absorbing flooring material that is "composed of a plurality of base panels laid on the installation surface and floor covering materials that cover the base panels, the base panels being a laminate of rectangular intermediate materials and rectangular underfloor materials, and in which the four sides of the intermediate materials of each base panel overlap with the four sides of the underfloor material in two or less places in a plan view." Among the test specimens of Examples 5 to 7, the test specimens of Examples 6 and 7 in particular showed improved load-bearing capacity, which revealed that the above-mentioned impact-absorbing flooring material has particularly improved load-bearing capacity.

[0058] On the other hand, the impact-absorbing flooring materials of Comparative Example 1, in which the distortion (ε(σmax)) of the intermediate material was less than 0.5%, Comparative Example 2, in which the flexural modulus of the intermediate material was less than 1 GPa, and Comparative Example 3, in which the floor underlayment did not have a foamed structure, did not have sufficient impact absorption properties.

[0059] Although the embodiments of the present disclosure have been described above, the above embodiments are merely examples of devices and methods for embodying the technical ideas of the present disclosure, and the technical ideas of the present disclosure do not specify the materials, shapes, structures, arrangements, etc. of the components. The technical ideas of the present disclosure can be modified in various ways within the technical scope defined by the claims. [Explanation of symbols]

[0060] 1. Flooring 11 Flooring material 12 Underfloor materials Sides 121, 122, 123, and 124 13 Intermediate materials Sides 131, 132, 133, and 134 14 Base panel 200 Impact load measuring device 210 Measuring Table 220 Impactor 221 Weight 222 striking section 230 Cushioning material 240 Load measurement means

Claims

1. Floor coverings and A floor underlayment material provided below the floor covering material; an intermediate material provided between the floor covering material and the underfloor material; Equipped with The underfloor material is made of a resin material and has a foam structure, The intermediate material is formed from a material containing a thermoplastic resin and an inorganic filler, and in a three-point bending test according to JIS K7074, the strain at which the bending strength is maximized (ε (σmax)) is 0.5% or more, and the bending modulus is 1 GPa or more. Shock absorbing flooring.

2. The inorganic filler has a scaly, plate-like or fibrous shape. The impact-absorbing floor material according to claim 1.

3. The strain ε (σmax) of the intermediate material is 3% or more. The impact-absorbing floor material according to claim 1 or 2.

4. The floor covering is made up of a plurality of base panels and the floor covering material that covers the base panels, The base panel is a laminate in which the rectangular intermediate material and the rectangular underfloor material are laminated, and in each of the base panels, the outer periphery of the intermediate material and the outer periphery of the underfloor material overlap on two sides or less in a plan view. The impact-absorbing floor material according to claim 1.

5. The distance between one side of the intermediate material and one side of the floor underlayment material opposite to the one side of the intermediate material in a plan view of the base panel is 20 mm or more. The impact-absorbing floor material according to claim 4.

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