Shock-absorbing flooring

Abstract

The present invention provides an impact-absorbing flooring material that offers shock absorption through its soft layer while minimizing resistance when moving heavy objects with casters. [Solution] The shock-absorbing flooring material comprises a floor top material, a floor subfloor material provided below the floor top material and made of a softer material than the floor top material, and an intermediate material provided between the floor top material and the floor subfloor material. The intermediate material has a bending rigidity of 10 Nm per unit width. 2 Above 100 Nm 2 The floor underlayment material is formed from a resin material mainly composed of polyethylene foam and has a foamed structure. The melting point of the polyethylene component, as measured by a differential scanning calorimeter, is 110°C or higher, and the Asker hardness C is between 20 and 60.

Description

[Technical Field]

[0001] This disclosure relates to shock-absorbing flooring materials. [Background technology]

[0002] In recent years, falls and fractures among the elderly have become a social problem, accounting for 10% of the factors that lead to the need for long-term care among the elderly. The location of fractures due to falls varies greatly depending on age, with the risk of femoral fractures increasing sharply after the age of 60. Femoral fractures require hospitalization and can result in prolonged periods of immobility, often leading to bedridden states or conditions requiring long-term care such as dementia. Therefore, flooring materials that reduce the risk of fractures by absorbing the impact of falls have been proposed (Patent Documents 1 and 2). In such flooring materials, shock absorption is achieved by laminating a soft layer of resin or rubber foam on the back side of a hard wooden surface material.

[0003] However, because the aforementioned flooring materials have a soft layer to absorb impact, when moving heavy objects with casters, such as electric care beds or meal carts, the casters tend to sink into the soft layer. As a result, a great deal of force is required to move heavy objects with casters, or the soft layer may be crushed and dented.

[0004] Therefore, a flooring material has been proposed that improves load-bearing capacity while maintaining shock absorption by providing a layer of resin intermediate material containing a certain proportion of inorganic filler on top of a conventional soft layer (Patent Document 3). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 3600726 [Patent Document 2] Patent No. 5244927 [Patent Document 3] Japanese Patent Publication No. 2022-156607 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in order to improve the impact absorption performance of the flooring material, there was still room for further improvement in the selection of the layers that make up the flooring material. This disclosure is made in view of the above points, and aims to provide an impact-absorbing flooring material that has excellent impact absorption performance and low resistance when moving heavy objects with casters. [Means for solving the problem]

[0007] To solve the above-mentioned problems, a flooring material according to one aspect of the present disclosure comprises a flooring material, a subfloor material provided below the flooring material and made of a material softer than the flooring material, and an intermediate material provided between the flooring material and the subfloor material, wherein the intermediate material has a bending rigidity of 10 Nm per unit width. 2 Above 100 Nm 2 The floor underlayment material is formed from a resin material mainly composed of polyethylene foam and has a foamed structure. The melting point of the polyethylene component, as measured by a differential scanning calorimeter, is 110°C or higher, and the Asker hardness C is between 20 and 60. [Effects of the Invention]

[0008] According to this disclosure, it is possible to obtain an impact-absorbing flooring material that has excellent impact absorption performance and low resistance when moving heavy objects with casters. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing one example of the configuration of the impact-absorbing flooring material relating to this disclosure. [Figure 2] This is a schematic diagram illustrating an impact load measuring device used to evaluate impact-absorbing flooring materials. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments shown below are illustrative of devices and methods for realizing the technical concept of this technology. Furthermore, the technical concept of this technology can be modified in various ways within the technical scope described in the claims.

[0011] <Overall composition of shock-absorbing flooring material> The impact-absorbing flooring material (hereinafter referred to as "flooring material") 1 related to this disclosure will be described below with reference to Figure 1. As shown in Figure 1, the flooring material 1 comprises a flooring material 11, a flooring base material 12 provided below the flooring material (on the side where the flooring material 1 is attached) and made of a softer material than the flooring material, and an intermediate material 13 provided between the flooring material 11 and the flooring base material 12.

[0012] The total thickness of flooring material 1 is preferably more than 7 mm and 25 mm or less. When the total thickness of flooring material 1 exceeds 7 mm, a good balance of shock absorption, walking comfort, and durability is achieved. Furthermore, when the total thickness of flooring material 1 is 25 mm or less, the thickness of flooring material 1 does not become excessive, resulting in a good fit during installation without excessive height differences between adjacent uninstalled areas of flooring material 1. The flooring materials 11, subfloor materials 12, and intermediate materials 13 will be described in detail below.

[0013] <Floor materials> The floor covering 11 is a layer that makes up the surface of the floor covering 1, and is responsible for various surface functions such as design, scratch resistance, stain resistance, and slip resistance. The floor covering 11 is made of a harder material than the floor base material 12. Preferably, the floor covering 11 is made of a resin material such as polypropylene, polyethylene, polyester, acrylic, or polyvinyl chloride, or a paper material. The thickness of the floor covering material 11 is preferably 0.1 mm or more and 5 mm or less. When the thickness of the floor covering material 11 is 0.1 mm or more, it is preferable because it is less likely to cause a sense of discomfort in walking due to wear or damage of the floor covering material 11. Also, when the thickness of the floor covering material 11 is 5 mm or less, it is preferable because the weight load can be reduced and the burden during construction can be alleviated.

[0014] <Floor underlayment material> The floor underlayment material 12 is a layer that constitutes the underlay of the back surface of the floor material 1, and has the function of absorbing impact by deforming when falling and alleviating the impact on the fallen person. The floor underlayment material 12 is formed of a resin material softer than the floor covering material 11 so that it can be deformed when falling. Specifically, the floor underlayment material 12 is formed of a resin material containing polyethylene as a main component and has a foamed structure by chemical foaming, physical foaming, supercritical foaming, etc. Here, the foamed structure of the floor underlayment material 12 may be any of foamed structures such as independent foaming and continuous foaming.

[0015] The melting point of the above polyethylene component is preferably 110°C or more. If those outside these ranges are used, there is a risk that the impact absorption performance cannot be fully exhibited when an impact is applied.

[0016] The Asker C hardness of the floor underlayment material 12 is 20 or more and 60 or less. If the Asker C hardness of the floor underlayment material 12 is less than 20, the floor underlayment material 12 is likely to deform, causing a sense of discomfort in walking or making the pedestrian lose balance and easily fall, which may lead to a decrease in safety etc. Also, if the Asker C hardness of the floor underlayment material 12 exceeds 60, there is a risk that the floor material 1 cannot fully exhibit the impact absorption performance when an impact is applied to the floor material 1.

[0017] Here, the "Asker C hardness" is a value measured with an Asker C hardness meter. This "Asker C hardness meter" is a measuring instrument for measuring hardness and is one of the durometers (spring type hardness meters) defined in the Japan Rubber Association Standard "SRIS 0101".

[0018] The thickness of the subfloor material 12 is preferably 4 mm or more and 15 mm or less. A thickness of 4 mm or more is preferable because it provides sufficient cushioning when a pedestrian falls. A thickness of 15 mm or less is also preferable because it prevents excessive deformation of the subfloor material 12 due to load, which would reduce its load-bearing capacity, and also prevents excessive sinking when walking, making it less likely for pedestrians to fall.

[0019] <Intermediate material> The intermediate material 13 is a layer provided between the flooring material 11 and the subfloor material 12. It supports the flooring material 11 on the subfloor material 12 in a way that distributes the load applied from the flooring material 11 to the subfloor material 12, thereby improving shock absorption and load-bearing capacity. The intermediate material 13 is composed of a resin substrate obtained by mixing a resin material and an inorganic filler so that it can exhibit the desired mechanical properties and thermal expansion properties.

[0020] Examples of resin materials include various polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, ABS resin, and various polyamides. Among these, polyolefins and polyvinyl chloride are preferred, and polyvinyl chloride is particularly preferred, considering versatility, mechanical properties, and thermal expansion properties.

[0021] Examples of inorganic fillers include silica, talc, calcium carbonate, barium sulfate, aluminum hydroxide, carbon fiber, and glass fiber. Among these, calcium carbonate is preferred due to its excellent processability and versatility. The intermediate material 13 preferably contains 30% to 85% by mass of the inorganic filler, and more preferably 50% to 85% by mass.

[0022] The thickness of the intermediate material 13 is preferably between 2 mm and 8 mm. When the thickness of the intermediate material 13 is 2 mm or more, it suppresses excessive deflection of the floor material 1 in the event of a fall, provides sufficient cushioning, and makes the floor material 1 less susceptible to damage. Furthermore, when the thickness of the intermediate material 13 of the floor material 1 is 8 mm or less, the mass does not become excessive, which is less likely to cause deterioration of workability during installation, and load distribution when an impact is applied is effectively achieved, providing sufficient cushioning.

[0023] The bending stiffness of the intermediate material 13 per unit width is 10 Nm 2 Above 100 Nm 2 The following applies: The bending stiffness of the intermediate material 13 per unit width is 10 Nm 2 If the bending stiffness is less than 100 Nm, it becomes more susceptible to localized impacts, leading to a decrease in load distribution and making it difficult to achieve sufficient shock absorption. Also, the bending stiffness of the intermediate material 13 per unit width is 100 Nm. 2 If the bending stiffness exceeds 100 Nm, the intermediate material 13 becomes too rigid, reducing its load distribution ability and making it difficult to obtain sufficient shock absorption, as well as increasing fatigue during walking. 2 If the length exceeds this limit, construction problems may arise, such as difficulty in cutting the material on-site.

[0024] <Method for evaluating the impact absorption properties of flooring materials> The method for evaluating the impact absorption of flooring material 1 will be explained 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 falling on the flooring material. The impact load F is measured by the method described in Japanese Patent Publication No. 2020-76764.

[0025] The impact load is measured using the impact load measuring device 100 shown in Figure 2. The impact load measuring device 100 comprises a measuring platform 110, an impact-applying body 120, a cushioning material 130, and a load measuring means 140. Note that the flooring material 1 shown in Figure 2 is the object of impact load measurement using the impact load measuring device 100, and is not part of the impact load measuring device 100.

[0026] The impact-applying body 120 has a weight 121 and a striking part 122. The weight 121 has a mass based on the pressure distribution applied to the trochanter of the femur due to a simulated fall. The striking part 122 is formed in a shape that simulates the trochanter of the femur. The cushioning material 130 is made of a material that mimics human soft tissue. The load measuring means 140 is a device that measures the force applied to the cushioning material 130 when the impact-applying body 120 is dropped onto the cushioning material 130, and a load cell is used for example.

[0027] When measuring the shock absorption of flooring materials, the flooring material 1 to be measured is placed between the cushioning material 130 and the load measuring means 140, as shown in Figure 2. The load measuring means 140 measures the change in force over time applied to the cushioning material 130 when the impact-applying body 120 is dropped onto the cushioning material 130 from a predetermined height corresponding to the height of the simulated fall, with the floor material 1 placed between the load measuring means (load cell) 140 positioned on the measuring stand 110 and the cushioning material 130. At this time, the load measuring means 140 measures the change in force over time applied by the impact-applying body 120 to the cushioning material 130 from the time the impact-applying body 120 contacts the cushioning material 130 until it stops, and the maximum value of the measured load is defined as the impact load F. At this time, the drop height of the impact-applying body 120 is set so that the impact load (standard impact load Fs) when impact is applied only to the cushioning material 130 is 5600N, in order to simulate the impact on the femur during an actual fall.

[0028] The impact load F on flooring material 1 is preferably 5000N or less, and more preferably 4000N or less, under the conditions described above. If the impact load exceeds 5000N, the risk of femoral fracture in elderly people becomes significantly higher.

[0029] <Effects of the flooring material related to this disclosure> The flooring material described above has the following effects. (1) The floor covering according to the present disclosure includes a floor surface material, a floor base material provided below the floor surface material and formed of a material softer than the floor surface material, and an intermediate material provided between the floor surface material and the floor base material. The intermediate material has a flexural rigidity per unit width of 10 Nm 2 or more and 100 Nm or less. The floor base material is formed of a resin material containing polyethylene as a main component and has a foamed structure. The melting point measured by a differential scanning calorimeter of the polyethylene component is 110°C or more, and the Asker hardness C is 20 or more and 60 or less. As a result, the floor covering has excellent shock absorption performance by the soft layer and less resistance when moving a heavy object with casters.

[0030] (2) In the floor covering according to the present disclosure, the thickness of the intermediate material may be 2 mm or more and 8 mm or less. As a result, it is possible to prevent the floor covering from being overly deflected during a fall, causing a sufficient buffering effect, and making the floor covering less likely to be damaged. Also, the mass of the floor covering does not become too large, making it less likely to cause deterioration of workability during construction, and effectively causing load dispersion when an impact is applied, so that a sufficient buffering effect can be obtained.

[0031] (3) In the floor covering according to the present disclosure, the intermediate material may be formed of a resin base material in which a resin material and an inorganic filler are mixed. As a result, it becomes easier for the intermediate material to exhibit the intended mechanical properties and thermal expansion properties.

[0032] (4) In the floor covering according to the present disclosure, the thickness of the floor base material may be 4 mm or more and 15 mm or less. As a result, a sufficient buffering effect can be obtained when a pedestrian falls, and it is possible to prevent the deformation of the floor base material due to the load from becoming too large and reducing the load-bearing capacity. Also, the sinking during walking does not become too large, making it preferable because it makes it less likely for a pedestrian to fall.

[0033] (5) In the floor covering according to the present disclosure, the inorganic filler may be at least one selected from mica, talc, and glass fiber. This makes it possible to obtain flooring materials with higher load-bearing capacity when the same amount of inorganic filler is added to the intermediate material. [Examples]

[0034] The flooring materials relating to this disclosure will be described below with reference to examples. However, the flooring materials relating to this disclosure are not limited to these examples.

[0035] <Example 1> As a subfloor material, polyethylene foam A (Asker C hardness 42, dimensions 450mm x 450mm x thickness 6mm), which is formed from a resin material mainly composed of polyethylene and has a foamed structure, and a rigid polyvinyl chloride resin board (dimensions 450mm x 450mm x thickness 4mm, calcium carbonate content 65wt%) were prepared as an intermediate material. These subfloor materials and intermediate materials were bonded together with a two-component urethane adhesive to create floor panels. The melting point of polyethylene foam A, as measured by differential scanning calorimeter, was 113°C. Next, the impact-absorbing flooring material of Example 1 was formed by bonding the top-of-the-floor material (TOLI Hospilium NW, 450mm x 450mm x 2mm thick) to the intermediate material side of the flooring panel using adhesive (TOLI Corporation, US Cement).

[0036] <Example 2> Except for setting the thickness of the underlayment material (polyethylene foam A) to 5 mm and the thickness of the intermediate material to 5 mm, the impact-absorbing floor material of Example 2 was obtained in the same manner as in Example 1.

[0037] <Example 3> Except for setting the thickness of the underlayment material (polyethylene foam A) to 4 mm and the thickness of the intermediate material to 6 mm, the impact-absorbing floor material of Example 3 was obtained in the same manner as in Example 1.

[0038] <Example 4> An impact-absorbing flooring material for Example 4 was obtained in the same manner as in Example 1, except that polyethylene foam B (Asker C hardness 20, dimensions 450 mm x 450 mm x thickness 6 mm), which is formed from a resin material mainly containing polyethylene and has a foamed structure, was used as the flooring material instead of polyethylene foam A. The melting point of polyethylene foam B, as measured by differential scanning calorimeter, was 113°C.

[0039] <Example 5> An impact-absorbing flooring material for Example 5 was obtained in the same manner as in Example 1, except that polyethylene foam C (Asker C hardness 60, dimensions 450 mm x 450 mm x thickness 6 mm), which is formed from a resin material mainly containing polyethylene and has a foamed structure, was used as the flooring material instead of polyethylene foam A. The melting point of polyethylene foam C, as measured by differential scanning calorimeter, was 116°C.

[0040] <Example 6> Except for setting the thickness of the underlayment material (polyethylene foam A) to 15 mm and the thickness of the intermediate material to 6 mm, the impact-absorbing floor material of Example 6 was obtained in the same manner as in Example 1.

[0041] <Comparative Example 1> A shock-absorbing flooring material for Comparative Example 1 was obtained in the same manner as in Example 1, except that polyethylene foam D (Asker C hardness 39, dimensions 450 mm x 450 mm x thickness 6 mm), which is formed from a resin material mainly containing polyethylene and has a foamed structure, was used as the flooring material instead of polyethylene foam A. The melting point of polyethylene foam D, as measured by differential scanning calorimeter, was 104°C.

[0042] <Comparative Example 2> The impact-absorbing flooring material for Comparative Example 2 was obtained in the same manner as for Comparative Example 1, except that the thickness of the underlayment material (polyethylene foam D) was 5 mm and the thickness of the intermediate material was 5 mm.

[0043] <Comparative Example 3> The impact-absorbing flooring material for Comparative Example 3 was obtained in the same manner as for Comparative Example 1, except that the thickness of the underlayment material (polyethylene foam D) was 4 mm and the thickness of the intermediate material was 6 mm.

[0044] <Comparative Example 4> A shock-absorbing flooring material for Comparative Example 4 was obtained in the same manner as in Example 1, except that polyethylene foam E (Asker C hardness 16, dimensions 450 mm x 450 mm x thickness 6 mm), which is formed from a resin material mainly containing polyethylene and has a foamed structure, was used as the flooring material instead of polyethylene foam A. The melting point of polyethylene foam E, as measured by differential scanning calorimeter, was 114°C.

[0045] <Comparative Example 5> Comparative Example 5, an impact-absorbing flooring material, was obtained in the same manner as in Example 1, except that polyethylene foam F (Asker C hardness 63, dimensions 450 mm x 450 mm x thickness 6 mm), which is formed from a resin material mainly containing polyethylene and has a foamed structure, was used as the flooring material instead of polyethylene foam A. The melting point of polyethylene foam F, as measured by differential scanning calorimeter, was 115°C.

[0046] [evaluation] (Impact load) The impact-absorbing floor materials of each example and comparative example were used as evaluation floor materials, and the impact load on the evaluation floor materials was measured. The impact load F applied to the evaluation floor materials was measured using an impact load measuring device (impact load measuring device 100 shown in Figure 2). This method is a measurement method described in Japanese Patent Application Publication No. 2020-76764, and can simulate the impact load applied to the femur when a user falls on the floor material. The impact load on the evaluated flooring material was measured by dropping the impact-applying element of the impact load measuring device from a simulated tipping height (50 cm) onto the evaluated flooring material with a cushioning material placed on top. At this time, the impact load [N] applied by the impact-applying element to the evaluated flooring material via the cushioning material was measured by a load measuring device.

[0047] The impact load measuring device was designed to the following specifications. • Measurement conditions Load cell / "TCLU-5A" manufactured by Tokyo Measuring Instruments Laboratory Co., Ltd. Accelerometer / Digital shock and vibration accelerometer "1340B" manufactured by Showa Sokki Co., Ltd. Measuring stand / surface plate size: 750mm x 1000mm x 125mm, weight: 185kg Weight body / Material: Stainless steel Weight striking section / Material: Stainless steel, machined, radius of curvature R: 100mm Impact-generating element / Weight: 5.85kg (including accelerometer) Cushioning material: "Human Skin Gel" (product name) manufactured by Exceel Co., Ltd., thickness: 20mm, Asker C hardness: 9 • Evaluation criteria Impact load less than 4000N: ○ Impact load of 4000N or more: ×

[0048] (Caster mobility) A trolley with casters (45mm wide, 150mm in diameter x 4 wheels) was placed on the flooring material of each example and comparative example, and a 100kg weight was placed on the platform. The ease of moving the trolley by hand was then assessed by sensory evaluation. The evaluation was conducted by 10 testers. • Evaluation criteria 7 or more people found it easy to move: ○ Six people or fewer found it easy to move: ×

[0049] Table 1 below shows the evaluation results for each example and comparative example.

[0050] [Table 1]

[0051] As shown in Table 1, the bending stiffness of the intermediate material per unit width is 10 Nm 2 Above 100 Nm 2 The following conditions were observed: each example of the impact-absorbing flooring material, in which the melting point of the polyethylene component of the flooring material measured by differential scanning calorimeter was 110°C or higher and the Asker hardness C was between 20 and 60, exhibited good impact absorption performance and caster mobility. On the other hand, the impact-absorbing flooring materials in each comparative example, whose polyethylene component of the underfloor material measured with a differential scanning calorimeter at a melting point of less than 110°C, showed good caster mobility, but their impact load was 4000N or more, indicating insufficient impact absorption performance.

[0052] While embodiments of the present disclosure have been described above, these embodiments are merely illustrative examples of devices and methods for realizing the technical concept of the present disclosure, and the technical concept of the present disclosure does not specify the material, shape, structure, arrangement, etc., of the components. The technical concept of the present disclosure can be modified in various ways within the technical scope defined by the claims described in the patent claims. [Explanation of Symbols]

[0053] 10 Flooring 11 Flooring material 12. Subflooring materials 13 Intermediate material 14 Flooring panels 100 Impact load measuring device 110 Measuring stand 120 Impact-generating element 121 Weight 122 Hitting Department 130 Cushioning material 140 Evaluated Flooring 150 Load measurement means

Claims

1. Flooring materials and A subfloor material is provided below the aforementioned flooring material and is made of a material softer than the aforementioned flooring material, An intermediate material provided between the flooring material and the subfloor material, Equipped with, The aforementioned intermediate material has a bending stiffness of 10 Nm per unit width. ２ Above 100 Nm ２ The following: The aforementioned floor underlayment material is formed from a resin material mainly composed of polyethylene, has a foamed structure, has a melting point of 110°C or higher as measured by a differential scanning calorimeter of the polyethylene component, and has an Asker hardness C of 20 to 60. Shock-absorbing flooring material.

2. The thickness of the intermediate material is 2 mm or more and 8 mm or less. The shock-absorbing flooring material according to claim 1.

3. The aforementioned intermediate material is formed from a resin substrate obtained by mixing a resin material with an inorganic filler. The shock-absorbing flooring material according to claim 1.

4. The aforementioned intermediate material contains 30% by mass or more and 85% by mass or less of the aforementioned inorganic filler. The shock-absorbing flooring material according to claim 3.

5. The thickness of the aforementioned subfloor material is 4 mm or more and 15 mm or less. The shock-absorbing flooring material according to claim 1.

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