JP7416319B2 - shock absorbing flooring - Google Patents

Description

TECHNICAL FIELD The present invention relates to a shock-absorbing flooring material that can suppress fractures of the femur caused by impacts caused by falls of, for example, elderly people or infants, and is used in hospitals, facilities for the elderly, childcare-related facilities, and the like.

Currently, falls and fractures in the elderly have become a social problem, and falls account for 10% of the reasons why elderly people require nursing care. In addition, falls and fractures account for 20 to 25% of medical accidents.
The location of fractures caused by falls varies depending on age, and the risk of femoral fractures increases sharply after the age of 60.
Fractures of the femur require hospital treatment and patients are unable to walk for long periods of time, which can lead to bone loss and worsen the symptoms, making them more likely to require nursing care.
In addition, fractures due to falls account for over 20% of all accidents at childcare-related facilities (kindergartens, nursery schools, certified child care centers).
Because of the above-mentioned problems, flooring materials have been invented that absorb the impact of falls 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 called long sheets, and in order to give these flooring materials shock absorption properties, the sheets themselves are foamed. (see paragraph [0040] and FIG. 3 of Patent Document 1), or a foamed resin sheet for impact absorption may be laminated on the base (see paragraph [0025] of Patent Document 2, and FIGS. 1 and 3). (See Figure 3).

Patent No. 3600726 Patent No. 5244927

However, many conventional flooring materials have shock-absorbing properties and have a soft layer that absorbs shocks, but these materials are used in hospitals and other places where static loads due to heavy objects such as beds or heavy objects are placed on casters. There was a problem in that when dynamic loads such as rolling were applied, the soft layer would collapse and dents would occur.
Therefore, an object of the present invention is to provide a shock-absorbing flooring material that has the absorption effect of a soft layer and also has durability such as static load resistance and dynamic load resistance.

A shock-absorbing flooring material according to one aspect of the present invention is a shock-absorbing flooring material that suppresses fractures of the femur caused by impact caused by a fall of a user, and includes a flooring material made of a hard material, and a lower part of the flooring material. A flooring material consisting of at least three layers: a flooring material made of a soft material provided in ² or more and 100 Nm ² or less.

Moreover, the impact-absorbing flooring material according to one aspect of the present invention is characterized in that the intermediate material has a thickness of 1 mm or more and 5 mm or less.

The impact-absorbing flooring material according to one aspect of the present invention is characterized in that the intermediate material is composed of a thermoplastic resin containing 20 wt% to 85 wt% of an inorganic additive.
The impact-absorbing flooring material according to one aspect of the present invention is characterized in that the inorganic additive contained in the intermediate material is calcium silicate or calcium carbonate.
The impact-absorbing flooring material according to one aspect of the present invention is characterized in that the flooring material has an Asker C hardness of 20 or more and 80 or less.
In the shock-absorbing flooring material according to one aspect of the present invention, the flooring material has a thickness of 2 mm or more and 10 mm or less, the flooring material has a thickness of 3 mm or more and 15 mm or less, and the overall thickness is It is characterized by being 5 mm or more and 20 mm or less.

The impact-absorbing flooring material according to one aspect of the present invention provides an impact-applying body that has a weight and shape based on the pressure distribution applied to the trochanter of the femur when the user falls, and applies the impact-applying body to the lower back of the user. The impact-applying body was dropped from a height based on the height of the impact-applying body under conditions set such that the standard impact load Fs generated when applying an impact to a cushioning material made of a material imitating human soft tissue was 6500N. It is characterized in that an impact load F generated when the floor material is dropped from the falling height and an impact is applied to the flooring material through the cushioning material is 2000N or more and 5000N or less.
Here, "impact load F" means a "value" (N) measured using the measurement method described in JP 2020-76764A.

The impact-absorbing flooring material according to one aspect of the present invention is characterized in that the shock-absorbing 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 shock-absorbing flooring material according to one aspect of the present invention is characterized in that the cushioning material has a thickness of 7 mm or more and 80 mm or less.

According to one aspect of the present invention, it is possible to provide a shock-absorbing flooring material that has the absorption effect of a soft layer and also has durability such as static load resistance and dynamic load resistance.

FIG. 3 is a cross-sectional view of the impact-absorbing flooring material according to the first embodiment, in which each member is separately arranged. FIG. 2 is a schematic diagram for explaining an impact excess load measuring device used for measuring impact-absorbing flooring materials.

(Embodiment 1)
Embodiments of the present invention will be described below mainly with reference to FIG.
Here, the drawings are schematic, and the relationship between the thickness and the planar dimension, the ratio of the thickness of each layer, etc. are different from the actual one. In addition, the embodiments shown below illustrate configurations for embodying the technical idea of the present invention, and the technical idea of the present invention is that the materials, shapes, structures, etc. It is not something specific. The technical idea of the present invention is within the technical scope defined by the claims, and various changes can be made thereto.

(Shock absorbing floor material 10)
In FIG. 1, reference numeral 10 denotes a shock-absorbing flooring material, and the shock-absorbing flooring material 10 suppresses the fracture of the femur caused by the impact caused by a user's fall. The shock-absorbing flooring material 10 can suppress fractures of the femur caused by impacts caused by falls of elderly people, infants, etc., and is used in hospitals, facilities for the elderly, childcare-related facilities, and the like. Note that the shock absorbing flooring material 10 is also referred to as the "flooring material 10" hereinafter.
As shown in FIG. 1, the shock absorbing flooring material 10 includes (1) a flooring material 20, (2) a subflooring material 30, (3) an intermediate material 40, (4) a pattern layer 50, and (5) a protective layer 60. It is configured.
Note that each layer and material of the shock absorbing flooring material 10 is not limited to the above (1) to (5), and one of the pattern layer 50 and the protective layer 60 may be omitted, there may be four layers, or both may be omitted. , three layers may be used.

(Floor material 20)
The floor material 20 is made of a hard material and constitutes a floor surface on which a user walks.
The flooring material 20 is made of, for example, a wooden base material such as plywood, a composite base material made of a mixture of wood flour and plastics, a polyolefin such as polyethylene (PE) or polypropylene (PP), or a resin such as vinyl chloride (PVC). It consists of a hard material such as a base material.
The thickness of the flooring material 20 is set to, for example, 2 mm or more and 10 mm or less.
If the thickness of the flooring material 20 is less than 2 mm, there is a possibility that it will be damaged during transportation or construction work. Moreover, if the thickness of the flooring material 20 exceeds 10 mm, it may become heavy and the burden of construction may increase.

(Floor base material 30)
The flooring material 30 is made of a soft material and is provided below the flooring material 20, and constitutes a shock absorbing section that absorbs shock.
The flooring material 30 is made of a flexible material such as a resin such as polyolefin, PVC, ethylene vinyl acetate copolymer (EVA), polystyrene (PS), or polyurethane (PU), and is made of a soft material such as a resin such as polyolefin, PVC, ethylene vinyl acetate copolymer (EVA), polystyrene (PS), or polyurethane (PU). Depending on the method, it has a foam structure such as independent foam or continuous foam.
The thickness of the flooring material 30 is set to, for example, 3 mm or more and 15 mm or less.
If the thickness of the flooring material 30 is less than 3 mm, the shock absorption properties will be reduced.
If the thickness of the flooring material 30 exceeds 15 mm, the floor will sink into the floor significantly, which may impede the feeling of walking.

(Asker C hardness)
The flooring material 30 has an Asker C hardness of, for example, 20 or more and 80 or less.
Here, "Asker C" refers to SRIS0101 (Japan Rubber Association Standard).
When the Asker C hardness of the floor base material 30 is less than "20", the floor is likely to deform, which may deteriorate walkability and cause a fall.
Further, when the Asker C hardness of the flooring material 30 exceeds "80", the flooring material 30 becomes difficult to deform and may not be able to sufficiently absorb the impact when a large impact is applied.

(Intermediate material 40)
The intermediate material 40 is provided between the flooring material 20 and the subflooring material 30, and acts as a support layer to disperse the load applied from the flooring material 20 to the subflooring material 30, and has shock absorption, dynamic load resistance, and static load resistance. It has the role of improving durability such as durability.
The intermediate material 40 is made of a hard material such as a wooden base material such as plywood, a polyolefin such as polyethylene (PE) or polypropylene (PP), or a resin base material such as vinyl chloride (PVC).
The thickness of the intermediate material 40 is set to, for example, 1 mm or more and 5 mm or less. The thickness of the intermediate material 40 is more preferably 2 mm or more and 4 mm or less.
If the thickness of the intermediate material 40 is less than 1 mm, it is likely to be damaged during transportation or construction work.
If the thickness of the intermediate material 40 exceeds 5 mm, the intermediate material 40 will become heavy and the machinability will deteriorate, resulting in an increased construction burden.

(bending rigidity)
The intermediate material 40 has a bending rigidity set to, for example, 10 Nm ² or more and 100 Nm ² or less.
If the bending rigidity of the intermediate member 40 is less than 10 Nm 2 , the intermediate member 40 will easily bend due to local impact, and the load cannot be dispersed, so that the effect of improving the impact absorption property will be weak.
If the bending rigidity of the intermediate material 40 exceeds 100 Nm ² , workability may deteriorate and fatigue during walking may increase.

(Content of inorganic additives)
The intermediate material 40 is made of a thermoplastic resin containing, for example, 20 wt% to 85 wt% of inorganic additives.
If the content of the inorganic additive is less than 20 wt%, the prescribed thickness and bending rigidity cannot be satisfied.
If the content of the inorganic additive exceeds 85 wt%, it becomes brittle and may break when subjected to impact.

(Inorganic additives contained)
The inorganic additive contained in the intermediate material 40 is, for example, "calcium silicate" or "calcium carbonate".
Here, "calcium silicate" is a type of silicate, and is a general term for a composition in which calcium oxide, silicon dioxide, water, etc. are combined in various proportions.
Here, "calcium carbonate" is a calcium carbonate represented by the compositional formula "CaCO ₃ ".
"Calcium carbonate" which is an inorganic additive not only improves the bending rigidity of the intermediate material 40 but also has excellent workability and economy.
Further, as long as the bending rigidity is within a specified range, it is also possible to foam the base material in order to reduce the weight.
On the other hand, "calcium silicate" not only improves the bending rigidity of the intermediate material 40 but also is lightweight and has excellent workability.

(Picture layer 50)
The pattern layer 50 is located on the surface side of the flooring material 30, provides design, and is provided as appropriate as necessary.
The pattern layer 50 is a sheet made of the same material as the flooring material 20, such as polyolefin or PVC, on which a pattern such as wood grain or a geometric pattern is applied.

(Protective layer 60)
The protective layer 60 is located on the surface side of the pattern layer 50 and protects the surface so as to improve durability such as chemical resistance, scratch resistance, and dent resistance, and is provided as appropriate. It is something.
The protective layer 60 is made of, for example, an acrylic coat or transparent PVC.

(entire floor)
The thickness of the entire floor of the shock absorbing floor material 10 is set to, for example, 5 mm or more and 20 mm or less.
If the thickness of the entire floor is less than 5 mm, it will not be possible to balance shock absorption, walking feel, and durability.
If the thickness of the entire floor exceeds 20 mm, it will be too thick for long PVC (usually 2 to 3 mm), and there is a possibility that it will not settle properly during construction.

(Impact load F)
The impact load F of the entire floor is set to, for example, 2000N or more and 5000N or less.
Here, "impact load F" means a "value" (N) measured using the measurement method described in JP 2020-76764A.
If the impact load F of the entire floor is less than 2000 N, the impact absorption capacity will be too strong and it will become difficult to walk on, which is not preferable.
If the impact load F of the entire floor exceeds 5000N, the impact absorption capacity will be weak and it will be difficult to adequately cope with the risk of femoral fracture, which is not preferable.

(Measurement method of impact load)
The method for measuring the impact load will be described below using FIG. 2 based on Japanese Patent Application Publication No. 2020-76764.
The impact load measuring method is carried out using an impact load measuring device 100 shown in FIG.
The impact load measuring device 100 includes (1) a measuring table 110, (2) an impact applying body 120, (3) a cushioning material 130, (4) an evaluation floor material 140, and (5) a load measuring means 150.
The impact applying body 120 has a weight 121 and a striking part 122.
Specifically, this is a method of simulatively measuring the impact load applied to the user's femur when the user falls on the flooring 10.
Evaluation of the same material as the flooring material 10 Based on the cushioning material 130, which is placed on top of the flooring material 140 and made of a material that simulates human soft tissue, and the pressure distribution applied to the trochanteric region of the femur during a simulated fall. It includes a weight 121 and a striking part 122 formed in a shape similar to the trochanter.
Here, the trochanteric part of the femur is located outside the hip joint capsule.
The integrated weight 121 and striking part 122 are dropped at a predetermined fall height based on the height of the fall to be simulated, and the weight 121 impacts the evaluation flooring material 140 with the striking part 122 in contact with the cushioning material 130. is applied, and the impact load generated on the evaluation floor material 140 is measured by the load measuring means 150.

(Dynamic viscoelasticity Tan δ of buffer material 130)
The dynamic viscoelasticity Tan δ of the buffer material 130 at a measurement frequency of 1 Hz at 25° C. is, for example, 0.1 or more and 0.7 or less.
Specifically, tan δ in a predetermined range at a measurement frequency of 1 Hz of the cushioning material 130 used in the impact load measuring device 100 is determined to be in the range of 0.1 or more and 07 or less. The hardness Kb of the cushioning material 130 is determined to be in the range of more than 0 and less than 16, and the thickness Ka of the cushioning material 130 is determined to be in the range of 7 mm or more and 80 mm or less. The Young's modulus Ky of the buffer material 130 is determined to be in the range of 0.05 MPa or more and 0.80 MPa or less. The impact load Ks of the buffer material 130 is determined to be in the range of 3500N or more and 10000N or less.
By selecting such a cushioning material 130, it is possible to select a cushioning material 130 that simulates the soft tissue of the human body, and therefore the relationship between the rigidity of the evaluation flooring material 140 and the risk of fracture can be further increased.

(Thickness Ka of cushioning material 130)
The thickness Ka of the cushioning material 130 is calculated to be, for example, in the range of 7 mm or more and 80 mm or less, and preferably in the range of 9 mm or more and 30 mm or less.
Further, the Young's modulus Ky of the cushioning material 130 is calculated, for example, in a range of 0.05 MPa or more and 0.80 MPa or less, preferably in a range of 0.1 MPa or more and 0.5 MPa or less.
The impact load Ks of the cushioning material 130 is such that the impact load generated by placing the cushioning material 130 on a rigid measuring table 110, dropping a weight 121, and applying an impact to the cushioning material 130 is 3500 N or more and 10000 N or less. It is calculated within the range of . The impact load Ks of the buffer material 130 is preferably calculated to be in the range of 5000N or more and 8000N or less.
The cushioning material 130, whose hardness (Asker C hardness) Kb, thickness Ka, Young's modulus Ky, and impact load Ks are determined to be within the ranges described above, is an optimal material that simulates the soft tissues of the human body when a user falls. Become.

(Features and effects of embodiments)
The features and effects of the embodiment are as follows.
(First characteristic point of the embodiment)
The first feature of the shock-absorbing flooring material 10 according to the embodiment is that it is a shock-absorbing flooring material that suppresses fractures of the femur caused by the impact caused by a user's fall. , a flooring material 10 consisting of at least three layers: a flooring material 30 made of a soft material provided below the flooring material 20, and an intermediate material 40 located between the flooring material 20 and the flooring material 30; The bending rigidity at a unit width of 40 is 10 Nm ² or more and 100 Nm ² or less. (Effect of first feature point)
According to the first characteristic point, the bending rigidity of the intermediate material 40 can be set optimally.
That is, if the intermediate material 40 has a bending rigidity of less than 10 Nm ² , it will easily bend due to local impact and the load cannot be dispersed, so that the effect of improving the impact absorption property of the intermediate material 40 will be weak.
If the bending rigidity of the intermediate material 40 exceeds 100 Nm ² , workability may deteriorate and fatigue during walking may increase.

(Second feature point of the embodiment)
A second feature of the shock absorbing floor material 10 according to the embodiment is that the thickness of the intermediate material 40 is 1 mm or more and 5 mm or less.
(Effect of second feature point)
According to the second characteristic point, the thickness of the intermediate material 40 can be set optimally.
That is, if the thickness of the intermediate material 40 is less than 1 mm, it is likely to be damaged during transportation or construction work.
If the thickness of the intermediate material 40 exceeds 5 mm, the intermediate material 40 will become heavy and the machinability will deteriorate, resulting in an increased construction burden.

(Third feature point of embodiment)
A third feature of the impact-absorbing flooring material 10 according to the embodiment is that the intermediate material 40 is composed of a thermoplastic resin containing 20 wt% to 85 wt% of an inorganic additive.
(Effect of third feature point)
According to the third characteristic point, the amount of the inorganic additive added to the intermediate material 40 can be set optimally.
That is, if the content of the inorganic additive is less than 20 wt%, the prescribed thickness and bending rigidity cannot be satisfied.
If the content of the inorganic additive exceeds 85 wt%, it becomes brittle and may break when subjected to impact.

(Fourth feature point of embodiment)
A fourth feature of the impact-absorbing flooring material 10 according to the embodiment is that the inorganic additive contained in the intermediate material 40 is calcium silicate or calcium carbonate.
(Effect of fourth feature point)
According to the fourth characteristic point, the inorganic additive contained in the intermediate material 40 can be optimally set.
That is, in addition to improving the bending rigidity of the intermediate material 40, calcium silicate is lightweight and has excellent workability.
Moreover, calcium carbonate not only improves the bending rigidity of the intermediate material 40 but also has excellent workability and economy.

(Fifth characteristic point of the embodiment)
A fifth feature of the shock absorbing flooring material 10 according to the embodiment is that the flooring material 30 has an Asker C hardness of 20 or more and 80 or less.
(Effect of fifth feature point)
According to the fifth characteristic point, the Asker C hardness of the flooring material 30 can be set optimally.
That is, when the Asker C hardness of the flooring material 30 is less than 20, the floor is likely to be deformed, and walkability may deteriorate, leading to a fall.
Further, when the Asker C hardness of the flooring material 30 exceeds 80, the flooring material 30 becomes difficult to deform and may not be able to sufficiently absorb the impact when a large impact is applied.

(Sixth feature point of embodiment)
A sixth feature of the shock absorbing flooring material 10 according to the embodiment is that the flooring material 20 has a thickness of 2 mm or more and 10 mm or less, the subfloor material 30 has a thickness of 3 mm or more and 15 mm or less, and the entire (Shock-absorbing floor material 10) is characterized by having a thickness of 5 mm or more and 20 mm or less.
(Effect of the 6th feature point)
According to the sixth characteristic point, the thickness of the flooring material 20 can be set optimally.
That is, if the thickness of the flooring material 20 is less than 2 mm, there is a possibility that it will be damaged during transportation or construction work.
Moreover, if the thickness of the flooring material 20 exceeds 10 mm, it may become heavy and the burden of construction may increase.
In addition to this, according to the sixth characteristic point, the thickness of the underfloor material 30 can be set optimally.
That is, if the thickness of the flooring material 30 is less than 3 mm, the impact absorption property will be reduced.
If the thickness of the floor base material 30 exceeds 15 mm, the floor will sink into the floor significantly, which may impede the feeling of walking.
Furthermore, according to the sixth characteristic point, the overall thickness of the shock absorbing flooring 10 can be set optimally.
That is, if the thickness of the entire floor is less than 5 mm, it is impossible to balance shock absorption, walking feel, and durability.
If the thickness of the entire floor exceeds 20 mm, it will be too thick for long PVC (usually 2 to 3 mm), and there is a possibility that it will not settle properly during construction.

(Seventh feature point of embodiment)
A seventh feature of the shock-absorbing flooring 10 according to the embodiment is that the impact-applying body 120 has a weight and shape based on the pressure distribution applied to the trochanter of the femur when the user falls. Under conditions set so that the standard impact load Fs generated when a shock is applied to the cushioning material 130 made of a material imitating human soft tissue by dropping it from a drop height based on the waist height of the human body is 6500N. It is characterized in that the impact load F generated when the impact applying body 120 is dropped from a falling height and an impact is applied to the flooring 10 through the cushioning material 130 is 2000 N or more and 5000 N or less.
Here, "impact load F" means a "value" (N) measured using the measurement method described in JP 2020-76764A.
(Effect of seventh feature point)
According to the seventh characteristic point, the impact load F of the impact absorbing flooring material 10 can be optimally set.
That is, if the impact load F of the entire floor is less than 2000 N, the impact absorption capacity will be too strong and it will become difficult to walk on, which is not preferable.
If the impact load F of the entire floor exceeds 5000N, the impact absorption capacity will be weak and it will be difficult to adequately cope with the risk of femoral fracture, which is not preferable.

(Eighth feature point of embodiment)
The eighth feature of the shock absorbing flooring material 10 according to the embodiment is that the cushioning material 130 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. It is characterized by
(Effect of the 8th feature point)
According to the eighth characteristic point, by selecting the cushioning material 130, it is possible to select a cushioning material 130 that simulates the soft tissue of the human body, so that the relationship between the stiffness of the evaluation flooring material 140 and the fracture risk can be further evaluated. can be increased.

(Ninth feature point of embodiment)
A ninth feature of the shock absorbing flooring material 10 according to the embodiment is that the cushioning material 130 has a thickness of 7 mm.
It is characterized by having a length of 80 mm or more.
(Effect of the ninth feature point)
According to the ninth characteristic point, the cushioning material 130 can be made of an optimal material that simulates the soft tissue of a human body when a user falls.

Examples 1 to 5 and Comparative Examples 1 and 2 will be described below. However, the present invention is not limited to Examples 1 to 5 below.
(Example 1)
The main conditions of Example 1 are shown in Table 1 below.
Note that in addition to Example 1, the following Table 1 also lists the conditions of Examples 2 to 5, Comparative Example 1, and Comparative Example 2.

In Example 1, as shown in Table 1 above, the size of the falling surface of the evaluation floor material 140 was 10,000 mm ² .
As the floor material 20, a vinyl chloride resin floor material with a thickness of 2 mm was used.
As the flooring material 30, a vinyl chloride resin foam having a thickness of 7 mm and a C hardness of "76" was used.
As the intermediate material 40, a hard vinyl chloride resin plate having a thickness of 4 mm and a bending rigidity of "69 Nm ² " was used to produce the impact-absorbing flooring material 10 of Example 1.

(Example 2)
As shown in Table 1, Example 2 is the same as Example 1 except that a PE resin foam with a thickness of 4 mm and a C hardness of "62" was used for the flooring material 30, and the impact-absorbing floor of Example 2 was Material 10 was manufactured. (Example 3)
In Example 3, as shown in Table 1, the flooring material 30 was made of PE resin foam with a thickness of 6.5 mm and a C hardness of "50", and the intermediate material 40 was made with a thickness of 3 mm and a bending rigidity of "10 Nm2 ^". The impact-absorbing flooring material 10 of Example 3 was manufactured in the same manner as Example 1 except for the following.

(Example 4)
In Example 4, as shown in Table 1, the impact-absorbing flooring material of Example 4 was manufactured in the same manner as in Example 1 except that the flooring material had a C hardness of "82".
(Example 5)
In Example 5, as shown in Table 1, the impact-absorbing flooring material of Example 5 was manufactured in the same manner as in Example 2 except that the flooring material was 2 mm thick and the C hardness was "60".

(Comparative example 1)
As shown in Table 1, Comparative Example 1 was the same as Example 3 except that the intermediate material had a thickness of 3 mm and a bending rigidity of "9 Nm ² ", and a shock absorbing flooring material of Comparative Example 1 was manufactured.
(Comparative example 2)
As shown in Table 1, Comparative Example 2 was the same as Example 3, except that the intermediate material was not laminated and a two-layer structure of upper flooring material and subflooring material was used, and the impact-absorbing flooring material of Comparative Example 2 was manufactured. .

(Evaluation item)
The evaluation items are as follows.
Note that the following evaluation items will be described later.
(1) Bending rigidity of intermediate material 40 (Nm ² )
(2) Impact load (N)
(3) Durability

(Impact load)
The impact load was measured using the method described in JP 2020-76764A.
The device 100 used for measuring impact load is as shown in FIG. 2, and its specifications are as follows.
(Specifications of device 100)
The load cell is "TCLU-5A" (model number) manufactured by Tokyo Sokki Kenkyusho Co., Ltd.
The accelerometer is a digital shock/vibration accelerometer “1340B” (model number) manufactured by Showa Sokki Co., Ltd.
The measuring table 110 has a surface plate size of 750 mm x 1000 mm x 125 mm and a weight of 185 kg.
The material of the weight 121 (weight body portion) is stainless steel.
The striking portion 122 is made of machined stainless steel and has a radius of curvature R of 100 mm.
The impact applying body 120 has a weight Sw of 5.85 kg (including the accelerometer).
The cushioning material 130 is "Human Skin Gel" (trade name) manufactured by Exile Co., Ltd., and has a thickness of 20 mm, an Asker C hardness of "7", and a Young's modulus of 0.22 MPa.
The dynamic viscoelasticity Tan δ is 0.24 (25° C., measurement frequency 1 Hz).

(durability)
Durability was tested by applying a load of 20 kg to resin casters with a width of 20 mm and a diameter of 50 mm, and making the casters reciprocate 3000 times.
After unloading, the appearance and dents were checked.

(judgement)
First, the determination is made regarding (1) the flooring material 10 having at least three layers, and (2) the bending rigidity (Nm ² ) of the intermediate material 40. The first determinations (1) and (2) will be described later.
A case where the flooring material 10 consists of at least three layers, ie, a floor covering material 20, a subfloor material 30, and an intermediate material 40, is considered to be "passed", and other cases are judged to be "failable".
The bending rigidity (Nm ² ) of the intermediate material 40 is defined as "pass" if it is 10 to 100 Nm ² , and "fail" if it is otherwise.

(Regarding the second judgment)
Second, the determination is based on (3) the thickness (m) of the flooring material 20, (4) the thickness (m) of the flooring material 30, (5) the C hardness of the flooring material 30, and (6) the intermediate material 40. They are thickness (m), (7) impact load (N), and (8) durability. The second determinations (3) to (8) will be described later.
Regarding the thickness (m) of the flooring material 20, a thickness of 2 to 10 m is considered to be "passed", and the rest is "fail".
The thickness (m) of the flooring material 30 is considered to be "pass" if it is 3 to 15 m, and "fail" if it is otherwise.
A C hardness of 20 to 80 for the flooring material 30 is considered to be "pass", and anything else is "fail".
Regarding the thickness (m) of the intermediate material 40, a thickness of 1 to 5 m is considered to be "acceptable", and other than that is "failable".
Regarding the impact load (N), a value of 2000 to 5000N is considered "pass", and anything else is considered "fail".

(durability)
Durability was determined as follows.
"〇" indicates a case where the recovery rate of the dent is 95% or more within one week after unloading, and there are no abnormal marks left by visual observation, and the item is considered to be "passed".
"X" indicates a case where the recovery rate of the dent is within 95% or when there are abnormal traces left by visual observation, and the test is judged as "fail".

(Evaluation results)
Regarding the first judgment (1) and (2), among Examples 1 to 5 and Comparative Examples 1 and 2, those whose evaluation results are all "pass" are applicable to Examples 1 to 5. It is 5.
Regarding the first determinations (1) and (2), among the evaluation results, Comparative Example 1 and Example 2 include one or more "fail" results.

(Comparative example 1)
In Comparative Example 1, as shown in Table 1, the bending rigidity of the intermediate material is "9 Nm ² ", which is less than "10 Nm ² ".
For this reason, the intermediate material is easily bent in response to localized impacts, and the load cannot be dispersed, so that the effect of improving the impact absorption property of the intermediate material is weak.
(Comparative example 2)
As shown in Table 1, Comparative Example 2 has no intermediate material, so it has no bending rigidity and is also inferior in durability.

(Evaluation results (2))
For the first (1) and (2) and second (3) to (8) of the determination, Examples 1 to 3 all passed.
Regarding the second judgments (3) to (8), Examples 4 to 5 include one or more "fail" results.
(Example 4)
In Example 4, as shown in Table 1, the flooring material has a C hardness of "82", which exceeds "80".
For this reason, the flooring material becomes difficult to deform, and there is a possibility that it will not be able to sufficiently absorb the impact when a large impact is applied.
(Example 5)
In Example 5, as shown in Table 1, the thickness of the flooring material is 2 mm, which is less than 3 mm.
Therefore, the impact load is "5164N", which exceeds "5000N", and the impact absorption property of the underfloor material is reduced.

10 Impact-absorbing floor material 20 Floor material 30 Sub-floor material 40 Intermediate material 50 Pattern layer 60 Protective layer 100 Impact load measuring device 110 Measuring stand 120 Impact imparting body 121 Weight 122 Impact part 130 Cushioning material 140 Evaluation floor material 150 Load measuring means

Claims (13)

A shock-absorbing flooring material that suppresses femoral fractures caused by impact caused by a user's fall,
A flooring material consisting of at least three layers: a flooring material made of a hard material, a flooring material made of a soft material provided below the flooring material, and an intermediate material located between the flooring material and the flooring material. and
The intermediate material has a bending rigidity in a unit width of 10 Nm ² or more and 100 Nm ² or less ,
The standard impact load Fs generated when the impact applying body is dropped from a fall height based on the user's waist height and applies an impact to a cushioning material made of a material imitating human soft tissue is 6500N. Under the conditions set to
The impact load F generated when the impact applying body is dropped from the falling height and an impact is applied to the flooring material through the cushioning material is 5000 N or less,
The shock absorbing flooring material is characterized in that the flooring material has an Asker C hardness of 76 or more and 82 or less . The shock absorbing flooring material according to claim 1,
The impact-absorbing flooring material is characterized in that the intermediate material has a thickness of 1 mm or more and 5 mm or less. In the shock absorbing flooring material according to claim 1 or claim 2,
The impact-absorbing flooring material is characterized in that the intermediate material is composed of a thermoplastic resin containing 20 wt% to 85 wt% of an inorganic additive. In the shock absorbing flooring material according to any one of claims 1 to 3,
A shock-absorbing flooring material characterized in that the inorganic additive contained in the intermediate material is calcium silicate or calcium carbonate. The shock absorbing flooring material according to any one of claims 1 to 4 ,
The flooring material has a thickness of 2 mm or more and 10 mm or less,
The floor base material has a thickness of 3 mm or more and 15 mm or less,
A shock absorbing flooring material characterized in that the entire thickness is 5 mm or more and 20 mm or less. The shock absorbing flooring material according to any one of claims 1 to 5 ,
The impact applying body has a weight of 5.85 kg based on the pressure distribution applied to the trochanteric part of the femur when the user falls down, and the impact applying body has a weight of 5.85 kg based on the pressure distribution applied to the trochanteric part of the femur when the user falls. A shock absorbing flooring material characterized in that the shape based on the pressure distribution applied to the child part is a hemispherical shape with a radius of curvature R of 100 mm. In the shock absorbing flooring material according to any one of claims 1 to 6 ,
The shock absorbing flooring material is characterized in that 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. In the shock absorbing flooring material according to any one of claims 1 to 7 ,
The shock-absorbing flooring material is characterized in that the cushioning material has a thickness of 7 mm or more and 80 mm or less. In the shock absorbing flooring material according to any one of claims 1 to 8,
A shock-absorbing flooring material, wherein the flooring material is made of polyethylene, polypropylene, or vinyl chloride. The shock absorbing flooring material according to any one of claims 1 to 9,
The impact-absorbing flooring material is characterized in that the flooring material is made of vinyl chloride, ethylene vinyl acetate copolymer, polystyrene, or polyurethane. In the shock absorbing flooring material according to any one of claims 1 to 10,
The impact-absorbing flooring material is characterized in that the intermediate material is a foamed base material. In the shock absorbing flooring material according to any one of claims 1 to 10,
The inorganic additive contained in the intermediate material is calcium carbonate,
The impact-absorbing flooring material is characterized in that the intermediate material is a foamed base material. In the shock absorbing flooring material according to any one of claims 1 to 12,
A shock absorbing flooring material characterized in that the shock load F is 2000N or more.

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