Shock absorbing flooring

Abstract

To provide a shock-absorbing flooring material capable of suppressing fracture of a femur caused by impact due to a fall of, for example, an elderly person or an infant, and having durability such as static load resistance and dynamic load resistance while having an absorbing effect by a soft material.SOLUTION: A shock-absorbing flooring material 10 for suppressing fracture of a femur caused by the shock due to the fall of a user comprises three layers of a floor material 20 made of a hard material, a floor base material 30 made of a soft material provided below the floor material 20, and an intermediate layer 40 positioned in the middle of the floor material 20 and the floor base material 30; the floor base material 30 has a thickness of 4 mm or more and 10 mm or less, and when a static compression test for measuring test force and displacement is performed, compressive strain of the floor base material 30 is 0.8 or less when energy is absorbed by 5 J. Further, when the static compression test is performed, compressive test force at 50% strain may be 1200 N or more and 1800 N or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a shock-absorbing flooring material that can prevent fractures of the femur caused by the impact of a fall, for example, of the elderly or small children, and is used in hospitals, elderly care facilities, childcare facilities, etc. [Background technology]

[0002] At present, falls and fractures among the elderly have become a social problem, accounting for 10% of the causes of elderly people needing nursing care.Fractures from falls also account for 20-25% of medical accidents. The location of fractures caused by falls varies by age, with the risk of hip fractures increasing sharply after the age of 60. Femoral fractures require hospitalization for treatment and result in the inability to walk for long periods of time, which can lead to a decrease in bone mass and a worsening of the symptoms, making the patient more likely to require nursing care. Additionally, in childcare facilities (kindergartens, nursery schools, certified childcare centers), accidents resulting in fractures due to falls accounted for just over 20% of all accidents in the three layers mentioned above.

[0003] Because of the problems mentioned above, flooring materials have been invented that absorb shock in the event of a fall and reduce the risk of fractures. For example, flooring materials used in hospitals and elderly care facilities are generally in the form of wide sheets known as long sheets, and in order to impart shock absorption to these flooring materials, the sheets themselves may be foamed (see paragraph

[0040] and Figure 3 of Patent Document 1), or a shock-absorbing foamed resin sheet may be laminated onto the base (see paragraph

[0025] and Figures 1 and 3 of Patent Document 2). On the other hand, the flooring materials used in hospitals and elderly care facilities are generally wide sheet-shaped flooring materials called long sheets. In order to impart shock absorption to these flooring materials, the sheets themselves may be foamed or a foamed resin sheet for shock absorption may be laminated on the base. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3600726 [Patent Document 2] Patent No. 5244927 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while many of the flooring materials that use the foaming agents described above have a soft layer to absorb shock, there is a problem in that when heavy objects such as beds are placed on the floor in hospitals or when heavy objects are rolled on casters, the soft layer can be crushed and dented. Therefore, an object of the present invention is to provide an impact absorbing floor material that has the absorption effect of a soft material, while also having durability such as static load resistance and dynamic load resistance. [Means for solving the problem]

[0006] The impact-absorbing flooring material according to one embodiment of the present invention is an impact-absorbing flooring material that prevents fractures of the femur caused by the impact of a user falling, and is composed of three layers: an upper floor material made of a hard material, an under-floor material made of a soft material placed below the upper floor material, and an intermediate layer located between the upper floor material and the under-floor material, the under-floor material having a thickness of 4mm to 10mm, and when a static compression test is conducted to measure test force and displacement, the compressive strain of the under-floor material when 5J of energy is absorbed is within 0.8.

[0007] Furthermore, the impact absorbing floor material according to one embodiment of the present invention is characterized in that, when the static compression test is carried out, the compression test force at 50% strain is 1200N or more and 1800N or less. In one embodiment of the impact absorbing floor material of the present invention, the thickness of the intermediate layer is 1 mm or more and 3 mm or less, and the bending stiffness per unit width is 0.1 Nm 2 More than 10.0Nm 2 The present invention is characterized in that: An impact-absorbing floor material according to one embodiment of the present invention is characterized in that the thickness of the floor covering material is 2 mm or more and 10 mm or less, and the overall thickness of the three layers is 5 mm or more and 20 mm or less.

[0008] One embodiment of the impact-absorbing flooring material of the present invention is characterized in that, under conditions set so that an impact-applying object having a weight and shape based on the pressure distribution applied to the trochanter of the femur when the user falls is dropped from a drop height based on the height of the user's waist, and an impact is applied to a cushioning material made of a material that mimics human soft tissue, the standard impact load Fs generated when the impact-applying object is dropped from the drop height and an impact is applied to the impact-absorbing flooring material through the cushioning material, the impact load F generated is 2000N or more and 5000N or less.

[0009] An impact absorbing floor material according to one embodiment of the present invention is characterized in that the cushioning material has a dynamic viscoelasticity Tan δ of 0.1 or more and 0.7 or less at 25° C. and a measurement frequency of 1 Hz. The impact absorbing floor material according to one embodiment of the present invention is characterized in that the thickness of the cushioning material is 7 mm or more and 80 mm or less. Effect of the Invention

[0010] According to one aspect of the present invention, it is possible to provide an impact absorbing floor material that has the absorption effect of a soft material, while also having durability such as static load resistance and dynamic load resistance. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a cross-sectional view of the shock absorbing floor material according to the first embodiment, in which each component is placed apart. [Diagram 2] FIG. 1 is a schematic diagram of a static compression testing machine used to measure impact absorbing floor materials. [Diagram 3] FIG. 11 is an explanatory diagram for explaining the relationship between a test force and a displacement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. Here, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc. differ from the actual ones. Furthermore, the embodiments shown below are examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the materials, shapes, structures, etc. of the components described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0013] In Figure 1, reference numeral 10 denotes an impact absorbing flooring material. The impact absorbing flooring material 10 can prevent femur fractures caused by the impact of a fall, for example, by elderly people or small children, and is used in hospitals, elderly care facilities, childcare facilities, etc. As shown in FIG. 1, the shock absorbing floor material 10 is composed of the following layers: The following layers will be described later. (1) Flooring material 20 (2) Floor underlayment 30 (3) Middle class 40 (4) 50 picture layers (5) Surface protective layer 60 The layers of the impact absorbing floor material 10 are not limited to the above (1) to (5), and it is also possible to omit either the pattern layer 50 or the surface protection layer 60 to make it four layers, or to omit both to make it three layers.

[0014] (floor material 20) The floor covering 20 constitutes the floor surface on which users walk, and is made of a hard material. The floor covering 20 is made of a hard material such as a wood base material such as plywood, a composite base material made of a mixture of wood powder and plastic, or a resin base material such as polyolefins such as polyethylene (PE) and polypropylene (PP) or polyvinyl chloride (PVC).

[0015] (Thickness of floor covering 20) The thickness of the floor covering 20 is 2 mm or more and 10 mm or less. If the thickness of the floor covering 20 is less than 2 mm, the rigidity decreases, and if it exceeds 10 mm, the rigidity is too high and the shock absorption properties decrease.

[0016] (Floor Underlayment 30) The underfloor material 30 is located below the overfloor material 20, constitutes a shock absorbing portion that absorbs shock, and is made of a soft material. The floor underlayment material 30 is a foam material made of soft materials such as resins such as polyolefin, PVC, ethylene vinyl acetate copolymer (EVA), polystyrene (PS), polyurethane (PU), etc., and has a foam structure such as closed or continuous foam produced by methods such as chemical foaming, physical foaming, and supercritical foaming.

[0017] (Thickness of floor underlayment 30) The thickness of the underfloor material 30 is, for example, 4 mm or more and 10 mm or less. If the thickness of the underfloor material 30 is less than 4 mm, the shock absorbing properties will decrease, and if it exceeds 10 mm, the floor will sink significantly, which may cause an inconvenience when walking.

[0018] (Middle class 40) The intermediate layer 40 is located between the over-floor material 20 and the under-floor material 30, is made of a hard material, and serves as a support layer to distribute the load applied from the over-floor material 20 to the under-floor material 30, thereby improving durability such as dynamic load resistance and static load resistance. The intermediate layer 40 is made of a hard material such as a wood base material such as plywood, a polyolefin such as polyethylene (PE) or polypropylene (PP), or a resin base material such as polyvinyl chloride (PVC).

[0019] (Thickness of intermediate layer 40, bending rigidity per unit width) The thickness of the intermediate layer 40 is 1 mm or more and 3 mm or less. If the thickness of the intermediate layer 40 is less than 1 mm, the durability is poor, and if it exceeds 3 mm, the weight is heavy. The bending stiffness of the intermediate layer 40 per unit width is 0.1 Nm 2 More than 10.0Nm 2 The following is the result. The bending stiffness of the intermediate layer 40 per unit width is 0.1 Nm2 If it is less than 10.0Nm, the rigidity is insufficient, and the improvement in durability and shock absorption due to the three-layer structure cannot be expected. 2 If it exceeds this value, the rigidity will be too high and the user may become fatigued when walking. As long as the bending stiffness is within the above-mentioned range, the base material of the intermediate layer 40 can be foamed to reduce the weight.

[0020] (Total thickness of the three layers) The total thickness of the three layers, including the thickness of the top floor material 20, the underfloor material 30 and the intermediate layer 40, is 5 mm or more and 20 mm or less. If the total thickness of the three layers is less than 5mm, it will be impossible to achieve a balance between shock absorption, walking comfort, and durability, and if it exceeds 20mm, it will be too thick for long PVC (usually 2 to 3mm), which may result in poor fit during installation.

[0021] (Picture layer 50) The pattern layer 50 is located on the surface of the floor covering 20 and provides a design, and is provided appropriately as required. The pattern layer 50 is a sheet made of the same material as the floor covering 20, such as polyolefin or PVC, on which a pattern such as wood grain or a geometric pattern is applied.

[0022] (Surface protective layer 60) The surface protective layer 60 is located on the surface of the design layer 50 and serves to protect the surface so as to improve durability such as chemical resistance, scratch resistance, and dent resistance. The surface protection layer 60 is made of an acrylic coating, transparent PVC, or the like. In addition, the surface of the surface protection layer 60 may be embossed (embossed using an embossing plate). By embossing the surface of the impact absorbing floor material 10, it is possible to provide a more three-dimensional feel to the touch. Although not shown, embossed patterns include, for example, duct grooves in wood grain boards, unevenness on the surface of a stone slab, textured cloth surface, matte finish, sand grain, hairline, and linear grooves.

[0023] (Method of manufacturing the impact absorbing floor material 10) The impact absorbing floor material 10 has the above-mentioned configuration and is manufactured as follows. An intermediate layer 40 made of a hard material is provided between the over-floor material 20 made of a hard material and the under-floor material 30 made of a soft material provided below the over-floor material 20. A pattern layer 50 is laid on the upper surface of the floor covering 20, and a surface protection layer 60 is further laid on the upper surface of the pattern layer 50 to manufacture the shock absorbing floor covering 10.

[0024] (Absorbed energy) When the floor underlayment material 30 is subjected to a static compression test described in the next section, the compression strain of the floor underlayment material 30 when 5 J of energy is absorbed is 0.8 or less. If it exceeds 0.8, the foam layer of the underfloor material 30 will absorb the energy and cause the floor to sink significantly, which may cause an inconvenience when walking. Here, the "compressive strain" is "compressive strain = thickness after deformation (mm) / thickness before deformation (mm)".

[0025] (Static compression test method) The compressive strain when 5J of energy is absorbed is measured using the following "static compression test." The static compression test is carried out using a static compression tester 100 as shown in FIG. 2 under the following conditions. (1) Size of sample 120: 100 mm square (2) Size of compression terminal 130: 50mm square (3) Compression speed: 10 m / min The sample 120 is placed on the test stand 110, a compression terminal 130 is placed in the center of the sample 120, and the test force and displacement are measured as the sample is gradually compressed.

[0026] The absorbed energy is expressed as the area under the load-displacement SS curve obtained in a static compression test, as shown in Figure 3 (see Figure 3). The absorbed energy is obtained by integrating the load. The compressive strain of the floor underlayment when absorbing 5J of energy is set to 0.8 or less, but if the displacement is 8mm or more, the floor will sink significantly in order to absorb the energy, which may interfere with the feeling of walking.

[0027] (Compression test force at 50% strain) When the impact absorbing floor material 10 undergoes a static compression test under the above conditions, the compression test force at 50% strain is 1200N or more and 1800N or less. If the test force exceeds 1800 N, the floor underlayment 30 (shock absorbing material) will be less likely to deform when subjected to a large impact, and may not be able to adequately absorb the impact when a large impact is applied. If the test force is less than 1200N, the floor will be easily deformed and even normal walking will cause the floor to deform, which may actually lead to a fall.

[0028] (Shock load) The shock absorbing floor material 10 is designed such that, under the following conditions, the shock load F generated when an impact applying object is dropped from a drop height and an impact is applied to the floor material via the cushioning material is 2000N or more and 5000N or less. The above conditions are set so that the standard impact load Fs generated when an impact-applying object, the weight and shape of which are based on the pressure distribution applied to the trochanter of the femur when the user falls, is dropped from a drop height based on the height of the user's waist to apply impact to a cushioning material made of a material simulating human soft tissue, is 6,500 N. If the impact load F is less than 2000N, the impact absorption capacity will be too strong, making walking difficult, which is undesirable, and if it exceeds 5000N, the impact absorption capacity will be weak, making it difficult to adequately address the risk of femoral fracture, which is also undesirable.

[0029] (buffer material) The above-mentioned buffer material has a dynamic viscoelasticity Tan δ of 0.1 or more and 0.7 or less at 25° C. and a measurement frequency of 1 Hz. The cushioning material must be between 7mm and 80mm thick.

[0030] (Actions and Effects of the First Embodiment) The effects and advantages of the embodiment are as follows. (1) According to this embodiment 1, the underfloor material 30 has a thickness of 4 mm or more and 10 mm or less. When a static compression test is conducted to measure the test force and displacement, the compressive strain of the underfloor material 30 when 5 J of energy is absorbed is within 0.8. This makes it possible to provide an impact absorbing floor material that has the absorption effect of a soft material while also having durability such as static load resistance and dynamic load resistance. If the thickness of the underfloor material 30 is less than 2 mm, the shock absorbing properties will decrease, and if it exceeds 10 mm, the floor will sink significantly, which may cause an inconvenience when walking. If the compressive strain of the floor underlayment 30 when absorbing 5 J of energy exceeds 0.8, the floor will sink significantly in order to absorb the energy, which may cause an adverse effect on the feeling of walking.

[0031] (2) In the first embodiment, when a static compression test is carried out, the compression test force at 50% strain is 1200 N or more and 1800 N or less. If the test force exceeds 1800 N, the floor underlayment 30 (shock absorbing material) will be less likely to deform when subjected to a large impact, and may not be able to adequately absorb the impact when a large impact is applied.

[0032] (3) According to the first embodiment, the thickness of the intermediate layer 40 is 1 mm or more and 3 mm or less, and the bending stiffness per unit width is 0.1 Nm 2 More than 10.0Nm 2 The following is the result. The thickness of the middle layer 40 is 1mm 0.1Nm 2 If it is less than 10.0Nm, the rigidity and thickness will be insufficient, and the improvement in durability and shock absorption that can be achieved by using three layers will not be expected. 2 If it exceeds this value, the rigidity will be too high and you may feel fatigued when walking.

[0033] (4) In the first embodiment, the floor covering 20 has a thickness of 2 mm to 10 mm, and the total thickness of the three layers is 5 mm to 20 mm. If the thickness of the floor covering 20 is less than 2 mm, the rigidity decreases, and if it exceeds 10 mm, the rigidity is too high and the shock absorption properties decrease. If the total thickness of the three layers is less than 5mm, it will be impossible to achieve a balance between shock absorption, walking comfort, and durability, and if it exceeds 20mm, it will be too thick for long PVC (usually 2 to 3mm), which may result in poor fit during installation.

[0034] (5) In this embodiment 1, an impact-applying object having a weight and shape based on the pressure distribution applied to the trochanter of the femur when the user falls is dropped from a drop height based on the height of the user's waist, and the standard impact load Fs generated when the impact is applied to a cushioning material made of a material simulating human soft tissue is set to be 6,500 N. When the impact-applying object is dropped from the drop height and an impact is applied to the shock-absorbing flooring 10 through the cushioning material, the impact load F generated is 2,000 N or more and 5,000 N or less. If the impact load F is less than 2000N, the impact absorption capacity will be too strong, making walking difficult, which is undesirable, and if it exceeds 5000N, the impact absorption capacity will be weak, making it difficult to adequately address the risk of femoral fracture, which is also undesirable.

[0035] (6) In the first embodiment, the buffer material has a dynamic viscoelasticity Tan δ of 0.1 or more and 0.7 or less at 25° C. and a measurement frequency of 1 Hz. (7) In the first embodiment, the cushioning material has a thickness of 7 mm or more and 80 mm or less. EXAMPLES

[0036] The present invention will be specifically described below with reference to Examples 1 to 3 and Comparative Examples 1 to 3. However, the present invention is not limited to the following Examples 1 to 3.

[0037] Example 1 The main conditions of Example 1 are as shown in Table 1 below. In addition, in Table 1 below, in addition to Example 1, the conditions for Example 2, Example 3, and Comparative Examples 1 to 3 are also shown.

[0038] [Table 1]

[0039] In Example 1, as shown in Table 1 above, the size of the drop surface of the evaluation floor material was 10,000 mm 2 The floor material is 2 mm thick and has a bending stiffness of 0.07 Nm per unit width. 2 The floor is made of polyvinyl chloride resin, and the underfloor material is a polyvinyl chloride resin foam with a thickness of 5 mm, C hardness of 60, and a foaming ratio of 5 times. The middle layer is a thickness of 2 mm and a bending stiffness of 0.51 N m. 2 The impact absorbing floor material of Example 1 was manufactured using the above hard polyvinyl chloride resin board.

[0040] Example 2 In Example 2, as shown in Table 2, an impact-absorbing floor material for Example 2 was produced in the same manner as in Example 1, except that the floor underlayment was a PE resin foam with a thickness of 6.5 mm, a C hardness of 50, and an expansion ratio of 10 times. Example 3 In Example 3, as shown in Table 2, the floor covering has a thickness of 3 mm and a bending stiffness of 0.5 Nm per unit width. 2 An impact absorbing floor material of Example 3 was produced in the same manner as in Example 2, except that:

[0041] Comparative Example 1 In Comparative Example 1, the intermediate layer was not laminated, and the floor was made of a two-layer structure consisting of an upper floor material and an underfloor material, as shown in Table 2. The impact absorbing floor material of Comparative Example 1 was produced in the same manner as in Example 2 except for the above. Comparative Example 2 In Comparative Example 2, as shown in Table 2, the intermediate layer had a thickness of 0.5 mm and a bending stiffness per unit width of 0.03 Nm 2 An impact absorbing floor material of Comparative Example 2 was produced in the same manner as in Example 1, except that a hard polyvinyl chloride resin plate was used. Comparative Example 3 In Comparative Example 3, as shown in Table 2, an impact absorbing floor material of Comparative Example 3 was produced in the same manner as in Example 3, except that the thickness of the floor underlayment was 3 mm.

[0042] (Evaluation items) The evaluation items are as follows: The following evaluation items will be described later. (1) Strain when absorbing 5J (2) Compressive test force at 50% strain [N] (3) Impact load (N / judgment) (4)Durability (5) Overall rating

[0043] (Strain when absorbing 5J) The strain at absorbing 5 J was measured using a static compression test method under the following conditions. A 100 x 100 mm sample is prepared and a 50 mm square terminal is placed on top of it. The specimen was compressed at a compression speed of 10 mm / min using an autograph (AGS-500NX, manufactured by Shimadzu Corporation), and the test force and displacement were measured. When absorbing 5 J, a compressive strain of 0.8 or less was deemed to be acceptable, and anything other than that, i.e., exceeding 0.8, was deemed to be unacceptable. The dynamic viscoelasticity Tan δ and complex modulus of elasticity E* of the floor underlayment were measured using a dynamic viscoelasticity measuring device "DMA8000" (model number) manufactured by PerkinElmer Co., Ltd., in compression mode at 25°C and a measurement frequency of 1 Hz.

[0044] (Compression test force at 50% strain) The compressive test force at 50% strain was measured when a static compression test was performed and the compressive test force at 50% strain was measured. The compressive test force at 50% strain was rated as pass if it was between 1200N and 1800N, and otherwise as fail.

[0045] (Measurement of impact load) The impact load was measured using a method for simulating the impact load applied to a user's femur when the user falls on flooring material (hereinafter referred to as "the impact load method in question"; see Patent Application No. 2019-192234). This measurement method involves placing a cushioning material made of a material that simulates human soft tissue on top of an evaluation flooring material made of the same material as the flooring material, a weight based on the pressure distribution applied to the trochanter of the femur due to a simulated fall, and an impact part formed in a shape that simulates the trochanter, and dropping the integrated weight and impact part at a predetermined drop height based on the height of the simulated fall, so that the weight applies an impact to the evaluation flooring material with the impact part in contact with the cushioning material, and the impact load generated on the evaluation flooring material is measured by a load measuring means. The impact load measuring method will be described later.

[0046] (Device specifications) The specifications of the device used in this impact load measurement method are as follows: (1) Load cell: Tokyo Measuring Instruments Laboratory Co., Ltd. "TCLU-5A" (model number) (2) Accelerometer: Showa Sokki Co., Ltd. digital shock and vibration accelerometer "1340B" (model number) (3) Measuring table / table size: 750mm x 1000mm x 125mm Weight: 185kg (4) Weight body: Material: Stainless steel (5) Weight striking part: Material: Machined stainless steel Curvature radius: 100 mm (6) Impactor / Weight Sw: 5.85 kg (including accelerometer) (7) Impactor / Weight Sw: 5.85 kg (including accelerometer) (8) Cushioning material: "Human Skin Gel" (product name) manufactured by Exseal Co., Ltd. (9) Thickness: 20 mm, Asker C hardness: 7, Young's modulus: 0.22 MPa (10) Dynamic viscoelasticity Tan δ: 0.24 (25°C, measurement frequency 1Hz)

[0047] (Impact load determination) The impact load is judged as follows. (1) If the test result is 2110N or less (low fracture risk for all age groups), the rating is "◎" (double circle), and the test result is a pass. (2) If the score is between 2,110 and 3,440 (low risk of fracture in the elderly), the answer is "O" and the person passes. (3) If the score is over 3,440 and under 5,000 (medium risk of fracture for elderly people), the answer is “△” and the person passes the test. (4) If the score is between 5,000 and 7,200 (high risk of fracture in the elderly), the answer is “×” and the person fails the test. (5) If it is over 7,200 (high fracture risk for all age groups), the answer is “XX” (two “X”s) and the test fails.

[0048] (durability) In durability tests, a load of 20 kg was applied to a resin caster measuring 20 mm in width and 50 mm in diameter, and the caster was moved back and forth 3,000 times. After unloading, the appearance and dents were visually inspected. The durability was evaluated as follows. (1) If the dent recovery rate is 95% or more one week after unloading and there are no abnormal marks or other abnormalities found upon visual inspection, the product is marked as "○" and passes the test. (2) If the dent restoration rate is less than 95% or if there are any abnormal marks when visually observed, the mark is marked "X" and the item is unsatisfactory.

[0049] (comprehensive evaluation) The overall evaluation is as follows: (1) If all evaluation items are passed, the result is marked as “○” and the item is passed. (2) In cases other than (1) above, i.e., if one or more of the evaluation items are failed, the result is “X” and the item is unsuccessful.

[0050] (Evaluation Results) The results are shown in Table 2.

[0051] [Table 2]

[0052] As shown in Table 2 above, Examples 1 to 3 passed the comprehensive evaluation. In contrast to this, all of Comparative Examples 1 to 3 failed. In Comparative Examples 1 and 2, the compressive strain of the floor underlayment when absorbing 5 J exceeded 0.8, which was too high, and the compressive test force at 50% strain was less than 1200 N, which was too low. In Comparative Example 1, as shown in Table 1, this is believed to be due to the absence of an intermediate layer, and it can be inferred that the intermediate layer is essential. As shown in Table 1, in Comparative Example 2, the cause was that the thickness of the intermediate layer was 0.5 mm, which was too thin, and it can be inferred that the thickness of the intermediate layer needs to exceed 0.5 mm. In Comparative Example 3, the compressive test force at 50% strain exceeded 1800 N, which was too high, and the impact load exceeded 5000, which was too high. As shown in Table 1, in Comparative Example 3, the thickness of the underfloor material was 3 mm, which was too thin, and it can be inferred that the thickness of the intermediate layer of the underfloor material needs to exceed 3 mm.

[0053] (This impact load measurement method) The present impact load measurement method has the following features: (1) The weight at the time of impact and the drop height are set so that the impact energy when the weight impacts the evaluation flooring material is 5J or more and 50J or less, and preferably 20J or more and 40J or less. (2) Select cushioning materials based on the user's height, weight, age, and gender. (3) The cushioning material to be selected has an Asker C hardness of more than 0 and less than 16, preferably 5 or greater and 10 or less.

[0054] (4) The cushioning material is selected so that the dynamic viscoelasticity value tan δ of the human soft tissue at a measurement frequency of 1 Hz is 0.1 to 0.7, preferably 0.2 to 0.50. (5) The cushioning material is selected so that the impact load generated when the cushioning material is placed on a rigid measurement table and a weight is dropped on the cushioning material to apply an impact thereto is 3,500 N or more and 10,000 N or less, preferably 5,000 N or more and 8,000 N or less. (6) The buffer material to be selected has a Young's modulus of 0.05 MPa or more and 0.80 MPa or less, and preferably 0.1 MPa or more and 0.5 MPa or less.

[0055] (7) The cushioning material should have a thickness of 7 mm or more and 80 mm or less, preferably 9 mm or more and 30 mm or less. (8) The contact surface of the striking part that comes into contact with the cushioning material has a curvature of R60 mm or more and R180 mm or less, and preferably R90 mm or more and R160 mm or less. (9) The measured value of the impact load is the maximum value of the impact load which changes over time. (10) The surface area of ​​the flooring material to be evaluated is 50 cm 2 More than 100cm, preferably 100cm 2 That's all. (11) A flooring safety evaluation method using a flooring impact load measurement method, in which a fracture load is calculated based on the user's age, sex, and bone density, and the fracture load and the impact load measured by the flooring impact load measurement method are displayed as indices. [Explanation of symbols]

[0056] 10. Shock-absorbing flooring 20 Floor coverings 30 Floor Underlayment 40 Middle Class 50 Picture Layer 60 Surface protective layer 60 Static Compression Tester 70 Test bench 80 Samples 90 Compression terminal

Claims

1. A shock-absorbing flooring material that prevents fractures of the femur caused by the impact of a user falling, A floor covering made of a hard material; A floor underlayment material made of a soft material provided below the floor covering material; The impact absorbing floor material is composed of three layers: the floor top material, the intermediate layer located between the floor underlayment, and The floor underlayment has a thickness of 4 mm or more and 10 mm or less, When a static compression test is conducted to measure the test force and displacement, the compressive strain of the floor underlayment is within 0.8 when 5 J of energy is absorbed. When the static compression test was performed, An impact absorbing flooring material characterized in that the compression test force at 50% strain is 1200N or more and 1800N or less.

2. The impact absorbing floor material according to claim 1, The intermediate layer has a thickness of 1 mm or more and 3 mm or less, Bending stiffness per unit width is 0.1 Nm 2 10.0Nm or more 2 An impact absorbing floor material characterized by the following:

3. The impact absorbing floor material according to claim 1 or 2, The floor covering has a thickness of 2 mm or more and 10 mm or less, The impact absorbing floor material is characterized in that the total thickness of the three layers is 5 mm or more and 20 mm or less.

4. The impact absorbing floor material according to any one of claims 1 to 3, An impact applying object having a weight and shape based on the pressure distribution applied to the trochanter of the femur when the user falls is dropped from a drop height based on the height of the user's waist, and an impact is applied to a cushioning material made of a material simulating human soft tissue under conditions set so that the standard impact load Fs generated is 6500 N. This shock-absorbing flooring material is characterized in that when the impact-applying body is dropped from the drop height and an impact is applied to the shock-absorbing flooring material via the cushioning material, the impact load F generated is 2000N or more and 5000N or less.

5. 5. The impact absorbing floor material according to claim 4, wherein the cushioning material has a dynamic viscoelasticity Tan δ of 0.1 to 0.7 at 25° C. and a measurement frequency of 1 Hz.

6. 6. The shock absorbing floor material according to claim 4, wherein the cushioning material has a thickness of 7 mm or more and 80 mm or less.

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