JP2016216928A - Impact relieving floor material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floor material having an excellent impact relieving property, sitting comfort and stepping comfort, while having thinness and light-weight.SOLUTION: In an impact relieving floor material, a floor material comprises a buffer layer arranged in the lowest layer, a plate material adjacently arranged on the upper side of the buffer layer, and a buffer layer arranged on the uppermost layer on the opposite side to the buffer layer via the plate material. The buffer layer arranged on the uppermost layer has a compressive elastic modulus within a range of 100-2500 kPa and a thickness within a range of 0.5-4 mm, the buffer layer arranged on the lowest layer has a compressive elastic modulus within a range of 10-500kPa, and the plate material has a product of a flexural elastic modulus and a thickness of 1.0×10or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flooring material that has excellent impact relaxation, sitting comfort, and stepping comfort while having thinness and lightness.

  Traditionally, tatami mats with a saddle as the core material have been used for flooring because of their excellent treading comfort, sitting comfort, and shock relaxation. However, tatami mats with a cocoon as a core material are so-called building material tatami mats using a wood material, a synthetic resin foam or the like as a core material in recent years because it is difficult to obtain raw materials.

  In the case of building material tatami using a wooden material, the surface is hard, especially when it is made thin, the seating comfort is poor and the impact relaxation is low. In the case of a building material tatami using a synthetic resin foam, it is easily crushed and has a low durability against impacts. When a thin tatami mat is used, the tatami mats are locally deformed to cause bottoming, resulting in a low impact relaxation property.

  In order to solve the above-described problems, for example, in Japanese Patent Application Laid-Open No. 2010-121287 (Patent Document 1), a synthetic fiber is entangled three-dimensionally on the upper surface of a heat insulating base material made of a synthetic resin foam. The two nonwoven fabric plates having different fiber densities are stacked one above the other, and the fiber density of the lower nonwoven fabric plate in contact with the heat insulating substrate is higher than the fiber density of the upper nonwoven fabric plate. A core material is disclosed. The core material for tatami mats disclosed in Patent Document 1 can promote the lightness of tatami mats while having rigidity capable of reinforcing a heat insulating base material made of a synthetic resin foam. Little change, cushioning on the upper surface.

In addition, International Publication No. 2010/128680 (Patent Document 2) includes a wet heat adhesive fiber, and is used for a flooring material formed of a nonwoven fiber structure in which fibers are fixed by fusion of the wet heat adhesive fiber. A molded article for flooring, which has an apparent density of 0.05 to 0.5 g / cm ³ and a hardness according to JIS A6519 of 130 G or less, is disclosed. Such a molded article for flooring disclosed in Patent Document 2 has high strength and excellent treading comfort and sitting comfort despite being thin and lightweight.

JP 2010-121287 A International Publication No. 2010/128680

  However, in the core material for tatami mats disclosed in Patent Document 1, rigidity and cushioning properties are given by the nonwoven fabric plate superimposed on the upper surface of the heat insulating base material, and the impact relaxation property is sufficient only by the upper nonwoven fabric plate. In particular, when the thickness of the synthetic resin foam or non-woven fabric is reduced to a thin tatami mat, there is a problem in that it is locally deformed to cause bottoming and the impact relaxation properties are reduced.

  Further, the molded article for flooring disclosed in Patent Document 2 is excellent in safety at the time of overturning, and is excellent in stepping comfort, walking comfort, sitting comfort, etc. In some cases, the rigidity as a flooring material is insufficient. Further, Patent Document 2 describes that an intermediate layer may be interposed between the floor material molded product and the floor finish, but does not describe in detail the properties of the intermediate layer. .

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to provide excellent impact relaxation, sitting comfort, and stepping comfort while having thinness and light weight. It is to provide a flooring that combines.

  One way to achieve a comfortable flooring is to give the flooring some degree of hardness, but such flooring is not necessarily good in terms of sitting comfort. Not only that, but when you put on your knees or elbows, you will feel more painful. On the other hand, a flooring that has a comfortable cushioning property that is comfortable to sit on, or that does not feel pain when the knees or elbows are put on, creates a fluffy sensation at the feet, which is not necessarily in terms of stepping comfort, especially walking. It was not good, and a flooring material excellent in both stepping comfort, particularly walking feeling and sitting comfort was not obtained.

  As a result of intensive studies, the inventors have determined that the compression elastic modulus of the uppermost layer of the flooring is in a specific range, and further, the amount of change in thickness during loading of the entire flooring is also in a specific range, In particular, the present inventors have found that a flooring material that can achieve both walking feeling and sitting comfort and that is excellent in impact relaxation property during a fall can be obtained.

That is, the present invention is arranged in the buffer layer arranged in the lowermost layer, the plate material arranged adjacent to the upper side of the buffer layer, and the uppermost layer on the side opposite to the buffer layer via the plate material The buffer layer disposed in the uppermost layer has a compression elastic modulus of 100 to 2500 kPa and a thickness in the range of 0.5 to 4 mm, and the buffer layer disposed in the lowermost layer. Is in the range of 10 to 500 kPa, and the plate material relates to an impact relaxation flooring whose product of bending elastic modulus and thickness is 1.0 × 10 ⁴ or more.

The impact relaxation flooring of the present invention preferably has a total thickness of 60 mm or less.
In the impact relaxation flooring of the present invention, it is preferable that the buffer layer disposed in the uppermost layer has an apparent density in the range of 0.08 to 0.2 g / cm ³ .

In the shock absorbing floor material of the present invention, the buffer layer disposed in the lowermost layer preferably has a thickness of 5 to 50 mm and an apparent density in the range of 0.03 to 0.15 g / cm ^3. .

In the impact mitigating floor material of the present invention, the plate material has a surface density of 2 kg / m ² or more, a product of the surface density, the flexural modulus, and the thickness is 3.0 × 10 ⁴ or more, and the thickness is 1 It is preferably ~ 20 mm.

The buffer layer in the impact mitigating flooring of the present invention is preferably a non-woven fiber structure.
Further, the present invention is a flooring in which a buffer layer is disposed on each of the upper and lower sides of the plate material, and the compression elastic modulus of the buffer layer disposed on the uppermost layer is 100 to 2500 kPa, and the thickness of the entire flooring material at 60 kg load Also provided is an impact mitigating flooring material having a variation of 0.5 to 1.8 mm.

  ADVANTAGE OF THE INVENTION According to this invention, the impact-relieving flooring which has the outstanding impact relaxation property, sitting comfort, and treading comfort can be provided, having thinness and lightness. Furthermore, the impact mitigating flooring material of the present invention is advantageous in that it can be used in place of a bed or a mattress in a public evacuation site in the event of a disaster from the viewpoint of its softness, sitting comfort, treading comfort, heat insulation, etc. Also have.

It is a figure which shows typically the impact relaxation flooring 1 of a preferable example of this invention. It is a figure which shows typically the impact-relieving flooring 1 'of another preferable example of this invention. It is a figure which shows typically the impact-relieving flooring 1 'of another more preferable example of this invention. It is a figure which shows typically the evaluation method of the impact relaxation property of the flooring in an Example and a comparative example.

The impact mitigating floor material of the present invention (hereinafter simply referred to as “floor material”) includes a buffer layer disposed in the lowermost layer, a plate material disposed adjacent to the upper side of the buffer layer, and the plate material. And a buffer layer disposed on the uppermost layer opposite to the buffer layer. Further, in the flooring of the present invention, (A) the buffer layer disposed in the uppermost layer has a compression elastic modulus of 100 to 2500 kPa and a thickness in the range of 0.5 to 4 mm, and (B) disposed in the lowermost layer. The buffer layer has a compression elastic modulus in the range of 10 to 500 kPa, and (C) the plate material has three characteristics that the product of the bending elastic modulus and the thickness is 1.0 × 10 ⁴ or more. It is what you have. With such a configuration, while having thinness and lightness, it has excellent shock relaxation properties, sitting comfort, and treading comfort, and mitigates the impact on the body during a fall, for example, it is difficult to fracture Flooring is provided.

  Here, FIG. 1 is a diagram schematically showing a flooring 1 as a preferred example of the present invention. The flooring 1 of the example shown in FIG. 1 has a structure in which buffer layers 3a and 3b are laminated adjacent to the upper side and the lower side of the plate material 2, respectively. In the example shown in FIG. 1, the buffer layer 3 b corresponds to the buffer layer disposed in the lowermost layer of the floor material 1, and the plate material 2 corresponds to the plate material disposed adjacent to the upper side of the buffer layer disposed in the lowermost layer. In addition, the buffer layer 3a corresponds to the buffer layer disposed as the uppermost layer. As in the example shown in FIG. 1, the surface material 4 may be further laminated on the upper side of the buffer layer 3 a that is the uppermost layer of the floor material 1.

  FIG. 2 is a view schematically showing a flooring 1 'of another preferred example of the present invention. The floor material 1 ′ of the example shown in FIG. 2 is the same as the floor material 1 of the example shown in FIG. 1 in that the buffer layer 3a, the plate material 2a, and the buffer layer 3b are provided in order from the upper side. A plate material 2b and a buffer layer 3c are further laminated in this order on the lower side. Thus, a structure in which a plurality of plate materials are provided and buffer layers are arranged on the upper and lower sides of each plate material may be employed. In the example shown in FIG. 2, the buffer layer 3c corresponds to the buffer layer disposed in the lowermost layer of the flooring 1 ', and the plate member 2b is disposed adjacent to the upper side of the buffer layer disposed in the lowermost layer. This corresponds to a buffer layer in which the buffer layer 3a is disposed as the uppermost layer. In the example shown in FIG. 2, the surface material 4 may be further laminated on the upper side of the buffer layer 3a that is the uppermost layer of the flooring 1 ', as in the example shown in FIG.

  FIG. 3 is a view schematically showing a flooring 1 ″ of still another example of the present invention. The floor material 1 '' of the example shown in FIG. 3 is the same as the floor material 1 of the example shown in FIG. 1 in that the buffer layer 3a, the plate material 2a, and the buffer layer 3b are provided in this order from the upper side. A buffer layer 3c, a plate material 2b, and a buffer layer 3d are further laminated in this order on the lower side. As described above, if the buffer layer disposed in the lowermost layer, the plate material disposed adjacent to the upper side of the buffer layer, and the buffer layer disposed on the upper side of the plate material are provided, a plurality of buffer layers are provided. Of course, they may be arranged adjacent to each other. In the example shown in FIG. 3, the buffer layer 3 d corresponds to the buffer layer disposed in the lowermost layer of the flooring 1 ″, and the plate material 2 b is disposed adjacent to the upper side of the buffer layer disposed in the lowermost layer. And the buffer layer 3a corresponds to the buffer layer disposed in the uppermost layer. In the example shown in FIG. 3 as well, as in the example shown in FIG. 1, the surface material 4 may be further laminated on the upper side of the buffer layer 3 a that is the uppermost layer of the floor material 1 ″.

  The flooring of the present invention is disposed in the buffer layer disposed in the lowermost layer, the plate disposed adjacent to the upper side of the buffer layer, and the uppermost layer opposite to the buffer layer via the plate. If it is provided with the buffer layer, it is not limited to the examples shown in FIGS. 1 to 3, and the plate material, the number of buffer layers, the arrangement, and the like may be appropriately changed.

  The flooring material of the present invention is characterized in that the compression elastic modulus of the buffer layer disposed in the uppermost layer is in the range of 100 to 2500 kPa and the thickness is in the range of 0.5 to 4 mm (the above feature (A)). .

  In the flooring material 1, 1 ′, 1 ″ of the present invention, the compression elastic modulus of the buffer layer 3a disposed in the uppermost layer is in the range of 100 to 2500 kPa, preferably in the range of 150 to 800 kPa, more preferably. Is in the range of 200-600 kPa. When the compression elastic modulus of the buffer layer 3a disposed on the uppermost layer of the flooring 1, 1 ', 1 "is less than 100 kPa, it is easily crushed by a load and it is difficult to obtain a good treading feeling. In addition, when the compression elastic modulus of the buffer layer 3a disposed on the uppermost layer of the flooring 1, 1 ', 1' 'exceeds 2500 kPa, the hardness becomes comfortable to step on, but the sitting comfort deteriorates, Impact relaxation is also reduced. In addition, the compression elastic modulus of the buffer layer 3a arranged in the uppermost layer of the flooring 1, 1 ′, 1 ″ is, for example, using a specimen cut out to a diameter of 29 mm in accordance with the provisions of JIS K 7181. A numerical value measured as an elastic modulus when compressed from a strain of 10% to 20% by a pressure plate at a test speed of 10 mm / min.

  In the flooring material 1, 1 ', 1' 'of the present invention, when the thickness of the buffer layer 3a arranged in the uppermost layer is less than 0.5 mm, the sitting comfort of the flooring material is deteriorated and the impact relaxation property is also improved. There is a problem that it becomes small and it is easy to feel pain when putting a knee or elbow on the floor. On the other hand, when the thickness of the buffer layer 3a arranged on the uppermost layer of the flooring materials 1, 1 ′, 1 ″ exceeds 4 mm, it becomes difficult to realize the thinness of the entire flooring material, and the treading comfort is reduced. In addition, there is a problem that the sinking during walking is large and it is difficult to walk, so that it is easy to fall. The buffer layer 3a disposed on the uppermost layer of the flooring materials 1, 1 ′, 1 ″ is more comfortable to sit on as the thickness increases, but the foot comfort becomes worse, and the shock relaxation properties as the thickness increases. However, if the thickness is the same, if the thickness of the buffer layer arranged at the lowermost layer of the entire flooring material is larger, the impact relaxation property as the entire flooring material becomes larger. As for the thickness of the buffer layer 3a arranged at the uppermost layer of '', it is more important that the thickness of the buffer layer 3a is sufficient to ensure a comfortable sitting, and the thickness within the above range is selected. For the reason that the total thickness of the flooring is as small as possible while ensuring a balance between sitting comfort and impact relaxation, the buffer layer 3a disposed on the uppermost layer of the flooring 1,1 ′, 1 ″ is used. The thickness is preferably in the range of 1 to 3.5 mm, and more preferably in the range of 1.5 to 3 mm.

The apparent density of the buffer layer 3a disposed in the uppermost layer in the flooring 1, 1 ′, 1 ″ of the present invention is not particularly limited, but is within the range of 0.08 to 0.2 g / cm ³ . It is preferable that it is in a range of 0.10 to 0.18 g / cm ³ . When the apparent density of the buffer layer 3a disposed on the uppermost layer of the flooring materials 1, 1 ', 1''is less than 0.08 g / cm ³ , the buffer layer is soft and easily crushed by a load, and a good stepping There is a tendency that it is difficult to obtain comfort, and when the apparent density exceeds 0.2 g / cm ³ , the buffer layer is hard and it tends to be difficult to obtain good impact relaxation properties. In addition, the apparent density of the buffer layer 3a arranged on the uppermost layer of the flooring 1, 1 ', 1''is a numerical value calculated by dividing the basis weight measured in accordance with the JIS L 1913 standard by the thickness. Point to.

  In the flooring 1, 1 ', 1' 'of the present invention, the buffer layer disposed in the lowermost layer (buffer layer 3b in the example shown in FIG. 1, buffer layer 3c in the example shown in FIG. 2, and in the example shown in FIG. 3) The compression elastic modulus of the buffer layer 3d) is in the range of 10 to 500 kPa (feature (B) described above). In the flooring of the present invention, the buffer layer disposed in the lowermost layer is a layer that alleviates the impact transmitted from the plate disposed adjacent to the upper side, and when the compression elastic modulus is less than 10 kPa, Although it has a high impact relaxation property, it may not be able to maintain its shape as a tatami mat, etc., and is inferior in durability, such as sag, and the thickness when used as a flooring material tends to be uneven due to the load. Tend to be difficult to obtain. Moreover, when the compression elastic modulus of the buffer layer arrange | positioned in the lowest layer in the flooring of this invention exceeds 500 kPa, the impact relaxation property of the whole flooring becomes inadequate. In addition, the compression elastic modulus of the buffer layer arrange | positioned at the lowest layer of a flooring can be measured by the method similar to the compression elastic modulus of the buffer layer 3a arrange | positioned above the board | plate materials 2 and 2a.

The apparent density of the buffer layer disposed in the lowermost layer is more it is preferably in the range of 0.03~0.15g / cm ^3, in the range of 0.05~0.10g / cm ³ preferable. In the flooring of the present invention, when the apparent density of the buffer layer disposed in the lowermost layer is less than 0.03 g / cm ³ , the buffer layer tends to be soft and have low shape retention and durability. Further, when the apparent density of the buffer layer disposed in the lowermost layer exceeds 0.15 g / cm ³ , the buffer layer is hard and the impact relaxation property tends to be low. In addition, the apparent density of the buffer layer arrange | positioned at the lowest layer of a flooring can be measured by the method similar to the apparent density of the buffer layer 3a arrange | positioned above the board | plate materials 2 and 2a.

  Moreover, the thickness of the buffer layer arranged in the lowermost layer in the flooring of the present invention is not particularly limited, but is preferably in the range of 5 to 50 mm, and in the range of 7 to 30 mm. More preferred. In the flooring of the present invention, when the thickness of the buffer layer disposed at the lowermost layer is less than 5 mm, the flooring may not have sufficient impact relaxation properties, and the plate may be bent when the impact is reduced. This is because bottoming tends to occur easily. In addition, in the flooring of the present invention, when the thickness of the buffer layer disposed in the lowermost layer exceeds 50 mm, the impact relaxation property of the flooring increases, but the thickness of the entire flooring (total thickness) increases. This is because it tends to pass.

In the flooring materials 1, 1 ′, 1 ″ of the present invention, the plate materials 2, 2 a, 2 b dissipate the impact transmitted through the buffer layer 3 a disposed on the upper side thereof in the surface direction and to the lower side thereof. It plays the role of communicating to the entire buffer layer. From the viewpoint of fulfilling such a role, the product of the flexural modulus and the thickness of the plate materials 2, 2a, 2b in the floor materials 1, 1 ′, 1 ″ of the present invention is 1.0 × 10 ⁴ or more (described above). (C)). The product of the flexural modulus and the thickness is an index that reflects the hardness of the plate material. If the product of the flexural modulus and thickness of the plate members 2, 2 a, 2 b is less than 1.0 × 10 ⁴ , there may be local deformation and bottoming out. There is a problem that the plate material is destroyed in the process. In order to dissipate the impact in the plane direction without breaking the plate material, the product of the bending elastic modulus and the thickness of the plate materials 2, 2a, 2b is preferably 1.5 × 10 ⁴ or more. As the plate members 2, 2a, 2b, as will be described later, it is possible to use an iron plate that is difficult to measure the bending elastic modulus, the higher the bending elastic modulus, the better, and the upper limit is not particularly limited, The product of the flexural modulus and the thickness is preferably 5.0 × 10 ⁵ or less in order to maintain the seating comfort of the flooring and to ensure the handleability when processing the plate material into a panel shape. 3.0 × 10 ⁵ or less is more preferable. In addition, the bending elastic modulus of the board | plate materials 2, 2a, 2b points out the numerical value measured based on prescription | regulation of JISK7171. Although not shown in the drawings, in the case of having a structure in which the plate members are laminated adjacent to each other, if the entire laminate of the plate members adjacent to each other has a product of the flexural modulus and thickness greater than the above-mentioned values. Be good.

In the floor materials 1, 1 ′, 1 ″ of the present invention, the surface density of the plate materials 2, 2a, 2b is not particularly limited, but is preferably ² kg / m ² or more, and preferably 5 kg / m ² or more. More preferred. When the surface density of the plate members 2, 2 a, 2 b is less than 2 kg / m ² , since the plate member is light, there is a tendency that the spring effect due to deformation of the buffer layer disposed in the lowermost layer cannot be fully exhibited. In addition, from the viewpoint of handling as much as possible during construction and transportation of the flooring material and reducing the load applied to the structural frame as much as possible, the surfaces of the plate materials 2, 2 a, 2 b in the flooring material 1, 1 ′, 1 ″ of the present invention. The density is preferably 20 kg / m ² or less, and more preferably 15 kg / m ² or less. The surface density of the plate materials 2, 2a, 2b refers to a numerical value calculated from the weight and area of the plate material.

In the flooring materials 1, 1 ′, 1 ″ of the present invention, the plate materials 2, 2a, 2b preferably have a product of surface density, bending elastic modulus, and thickness of 3.0 × 10 ⁴ or more. More preferably, it is 0 × 10 ⁴ or more. The product of the surface density, the flexural modulus, and the thickness is an index that reflects the impact relaxation that the plate itself works as a weight in addition to the impact relaxation due to the hardness of the plate. When the product of the surface density, flexural modulus, and thickness of the plate members 2, 2a, and 2b is less than 3.0 × 10 ⁴ , the plate member is locally deformed when subjected to an impact, thereby It tends to be difficult to dissipate in the direction, making it difficult to effectively convey the impact to the lowermost impact layer. Moreover, in order to ensure the handleability when processing a flooring into a panel shape, the product of the surface density, bending elastic modulus, and thickness of the plate members 2, 2a, 2b is 5.0 × 10 ⁶ or less. It is preferable that it is 3.0 × 10 ⁶ or less.

  Further, the thickness of the plate materials 2, 2a, 2b in the floor materials 1, 1 ', 1' 'of the present invention is not particularly limited, but is preferably within a range of 1-20 mm, and within a range of 3-10 mm. More preferably. The thickness of the plate members 2, 2 a, 2 b is preferably as small as possible considering the total thickness (total thickness) of the floor materials 1, 1 ′, 1 ″, but if it is too small, the hardness tends to be small. When the thickness of the plate members 2, 2 a, 2 b is less than 1 mm, it tends to be locally deformed when subjected to an impact and cannot be dissipated in the surface direction. It tends to be difficult to reduce the overall thickness.

  As described above, the flooring of the present invention includes a buffer layer disposed at the lowermost layer, a plate disposed adjacent to the upper side of the buffer layer, and the buffer layer opposite to the buffer layer via the plate. In addition to providing the buffer layer disposed on the uppermost layer, the buffer layer only needs to have the features (A), (B), and (C) described above. For example, the buffer layer disposed on the uppermost layer of the flooring and In the case where a buffer layer is provided in addition to the buffer layer arranged at the lowermost layer of the flooring (for example, the buffer layer 3b in the example shown in FIG. 2 and the buffer layers 3b and 3c in the example shown in FIG. 3) If so, the thickness, compression modulus, apparent density (in the case of a non-woven fiber structure) and the like are not particularly limited.

  The overall thickness (total thickness) of the flooring materials 1, 1 ′, 1 ″ of the present invention is not particularly limited, but is preferably 60 mm or less, and more preferably 20 mm or less. According to the present invention, it is possible to provide a flooring material that has excellent impact relaxation, sitting comfort, and treading comfort while having a total thickness that is comparable to or smaller than a conventional tatami mat (total thickness 55-60 mm). Can do. When the total thickness of the flooring materials 1, 1 ', 1' 'exceeds 60mm, it takes time and effort to lower the entire groundwork in order to keep the floor height constant with other rooms. It tends to be like that. Moreover, from the reason of the strength of the flooring and the handling property at the time of construction, the total thickness of the flooring 1, 1 ', 1' 'is preferably 1 mm or more, and more preferably 5 mm or more.

The flooring material 1, 1 ′, 1 ″ of the present invention is not particularly limited in terms of surface density, but has excellent impact relaxation, sitting comfort, and stepping comfort while having light weight as described above. Therefore, it is preferably 30 kg / m ² or less, and more preferably 25 kg / m ² or less. Also, for reasons such as easily fall by it would move during walking and too light, flooring 1,1 ', 1' are preferably surface density is 1 kg / m ² or more ', 2 kg / m ² More preferably.

  Each layer of the flooring may be adhered to each other with an adhesive, or at least partly covered with a cover or the like (note that even when a cover is provided on the lower side of the flooring, the buffer layer is “ It may be configured to maintain a laminated state by being “the lowest layer of the flooring”.

  The material for forming the buffer layer used for the flooring 1, 1 ', 1' 'of the present invention is not particularly limited, and plastic foam (for example, foamed styrene, foamed urethane, foamed polyolefin, etc.), Those having a buffering action such as rubber or elastomer, fiber structures (structures composed of woven fabric, knitted fabric, nonwoven fabric, etc.) can be used. As a buffer layer arrange | positioned at the uppermost layer of the flooring mentioned above, what is necessary is just to use what was formed with these materials and satisfy | fills the characteristic (A) mentioned above, and was arrange | positioned at the lowermost layer of the flooring mentioned above. The buffer layer may be formed of these materials and satisfy the above-described feature (B). Among these, it is preferable to use a buffer layer formed of a non-woven fiber structure because it has an appropriate cushioning property and easily dissipates impact in the surface direction by the constituent fibers.

  Non-woven fiber structures include, for example, molding in which nonwoven fabrics are fixed by mechanical compression treatment (needle punch, etc.), partial hot-pressure fusion treatment (hot embossing, etc.), adhesion or fusion treatment with a binder component, etc. The body is mentioned. Examples of fibers constituting the nonwoven fabric include polyolefin fibers, (meth) acrylic fibers, polyvinyl alcohol fibers, vinyl chloride fibers, styrene fibers, polyester fibers, polyamide fibers, polycarbonate fibers, and polyurethane fibers. Etc. Of these fibers, polyester fibers, polyamide fibers, or composite fibers containing these fibers are widely used.

Examples of the polyester resin constituting the polyester fiber include aromatic polyester resins such as poly C _2-4 alkylene arylate resins (polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), In particular, a polyethylene terephthalate resin such as PET is preferable. In addition to the ethylene terephthalate unit, the polyethylene terephthalate-based resin includes other dicarboxylic acids (for example, isophthalic acid, naphthalene-2,6-dicarboxylic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, bis (carboxyphenyl) ethane, 5-sodium sulfoisophthalic acid, etc.) and diols (eg, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexane-1,4-dimethanol, polyethylene glycol , Polytetramethylene glycol and the like) may be included at a ratio of about 20 mol% or less.

  Polyamide resins constituting the polyamide fibers include aliphatic polyamides such as polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 12, and polyamide 6-12, and copolymers thereof, aromatic dicarboxylic acids and aliphatic diamines. A semi-aromatic polyamide synthesized from these is preferred. These polyamide-based resins may also contain other copolymerizable units.

  The average fineness of the fibers constituting the non-woven fiber structure is not particularly limited. However, when the non-woven fiber structure is used for the buffer layer disposed on the upper side of the plate material, a good sitting comfort and treading are provided. In order to obtain comfort, the average fineness is preferably in the range of 0.1 to 30 dtex, and more preferably in the range of 0.5 to 20 dtex. Moreover, when using a nonwoven fiber structure for the buffer layer arrange | positioned at the lowest layer of a flooring material, in order to obtain favorable impact-relieving property and durability with respect to sag, the average fineness is 0.5-80 dtex. Is preferably within the range of 1 to 50 dtex.

  The non-woven fiber structure (or fiber) is further added to a conventionally known appropriate additive, for example, a stabilizer (a heat stabilizer such as a copper compound, an ultraviolet absorber, a light stabilizer, an antioxidant, etc.), a dispersant, Thickeners, fine particles, colorants, antistatic agents, flame retardants, plasticizers, lubricants, crystallization rate retarders, lubricants, antibacterial agents, insect and acaricides, antifungal agents, matting agents, heat storage agents, fragrances Further, it may contain a fluorescent brightening agent, a lubricant and the like. These additives may be carried on the structure surface or may be contained in the fiber.

  In the present invention, the binder component (particularly, the binder component (particularly, the polyester fiber, the polyamide fiber, the polyolefin resin, the polyvinyl alcohol resin, etc.) is used among the nonwoven fiber structures. Fiber structure fixed by fusion of fibers), and a structure including wet heat adhesive fibers and fixing the fibers by fusion of the wet heat adhesive fibers from the viewpoint of achieving both impact relaxation and strength. The body (nonwoven fibrous structure containing wet heat adhesive fibers) is particularly preferred. A structure including wet heat adhesive fibers and having the fibers fixed by fusion of the wet heat adhesive fibers (hereinafter sometimes referred to as “nonwoven fiber structure including wet heat adhesive fibers”) is, for example, It can be obtained by jetting high temperature steam. Since the internal structure of the nonwoven fiber structure obtained by spraying high-temperature steam is uniformly bonded in the thickness direction, high strength can be ensured while maintaining the fiber structure.

The wet heat adhesive fiber is configured to include at least a wet heat adhesive resin capable of exhibiting an adhesive function when high-temperature steam is jetted. Specific wet heat adhesive resins include thermoplastic resins that are softened with hot water (e.g., 80 to 120 [deg.] C., particularly 95 to 100 [deg.] C.) and can be self-adhered or bonded to other fibers, such as ethylene-vinyl alcohol. Examples thereof include vinyl alcohol polymers such as a copolymer, polylactic acid resins such as polylactic acid, and (meth) acrylic copolymers containing (meth) acrylamide units. Furthermore, it may be an elastomer (for example, a polyolefin-based elastomer, a polyester-based elastomer, a polyamide-based elastomer, a polyurethane-based elastomer, a styrene-based elastomer, etc.) that can exhibit an adhesive function when jetting high-temperature steam. These wet heat adhesive resins can be used alone or in combination of two or more. Of these, vinyl alcohol polymers containing α-C _2-10 olefin units such as ethylene and propylene, particularly ethylene-vinyl alcohol copolymers are preferred.

  The cross-sectional shape (cross-sectional shape perpendicular to the length direction of the fiber) of wet heat adhesive fibers is limited to general solid cross-sectional shapes such as round cross-sections and irregular cross-sections (flat, elliptical, polygonal, etc.) It may not be a hollow cross-sectional shape. The wet heat adhesive fiber may be a composite fiber composed of a plurality of resins including at least a wet heat adhesive resin. The composite fiber only needs to have a wet heat adhesive resin on at least a part of the fiber surface, but from the viewpoint of adhesiveness, it is preferable to have a wet heat adhesive resin continuous in the length direction on the fiber surface.

  Examples of the cross-sectional structure of the composite fiber in which the wet heat adhesive resin occupies the surface include a core-sheath type, a sea-island type, a side-by-side type, a multi-layer bonding type, a radial bonding type, and a random composite type. Among these cross-sectional structures, a core-sheath structure in which the wet heat adhesive resin covers the entire surface of the fiber (that is, the sheath portion is made of the wet heat adhesive resin because it is a structure with high adhesiveness. A core-sheath structure) is preferred. The core-sheath structure may be a fiber in which a wet heat adhesive resin is coated on the surface of a fiber composed of another fiber-forming polymer.

  In the case of a composite fiber, wet heat adhesive resins may be combined with each other, but may be combined with non-wet heat adhesive resins. Non-wet heat adhesive resins include water-insoluble or hydrophobic resins such as polyolefin resins, (meth) acrylic resins, vinyl chloride resins, styrene resins, polyester resins, polyamide resins, polycarbonate resins, polyurethanes Resin, thermoplastic elastomer and the like. These non-wet heat adhesive resins can be used alone or in combination of two or more.

  Among these non-wet heat adhesive resins, from the viewpoint of heat resistance and dimensional stability, resins having a melting point higher than that of wet heat adhesive resins (particularly ethylene-vinyl alcohol copolymers), such as polypropylene resins and polyester resins Resins and polyamide resins, particularly polyester resins and polyamide resins are preferred from the standpoint of excellent balance between heat resistance and fiber-forming properties. Polyester resins include terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, phthalic acid, α, β- (4-carbophenoxy) ethane, 4,4-dicarboxydiphenyl, 5-sodium sulfoisophthalic acid, etc. Aromatic dicarboxylic acids, azelaic acid, adipic acid, sebacic acid and other aliphatic dicarboxylic acids or their esters, ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexane Examples thereof include fiber-forming polyester resins composed of diols such as diol, neopentyl glycol, cyclohexane-1,4-dimethanol, polyethylene glycol, and polytetramethylene glycol. More than 80 mol% of the structural units are ethylene terephthalate. single Is preferred. Examples of the polyamide-based resin include aliphatic polyamides mainly composed of nylon 6, nylon 66, and nylon 12, and polyamides containing a small amount of the third component may be used.

  The nonwoven fiber structure may further contain non-wet heat adhesive fibers in addition to the wet heat adhesive fibers. Examples of the non-wet heat adhesive fibers include cellulose fibers (for example, rayon fibers, acetate fibers, etc.) in addition to the fibers formed of the non-humid heat adhesive resin constituting the composite fiber. These non-wet heat adhesive fibers can be used alone or in combination of two or more. These non-wet heat adhesive fibers can be used alone or in combination of two or more. These non-wet heat adhesive fibers can be selected according to the target properties, and when combined with semi-synthetic fibers such as rayon, a fiber structure having relatively high density and high mechanical properties can be obtained.

  The ratio (mass ratio) of the wet heat adhesive fiber and the non-wet heat adhesive fiber is not particularly limited, but the wet heat adhesive fiber / non-wet heat adhesive fiber = 100/0 to 20/80. Preferably, it is 100/0 to 50/50.

  The non-woven fiber structure containing the wet heat adhesive fibers is not particularly limited in terms of the fiber adhesion rate by fusing the wet heat adhesive fibers of the fibers constituting the non-woven fiber structure, but is arranged in the uppermost layer of the flooring. When using a non-woven fiber structure for the buffer layer, it is preferably in the range of 10 to 85%, preferably in the range of 20 to 60% in order to obtain good sitting comfort and treading comfort. Is more preferable. In addition, when using a non-woven fiber structure for the buffer layer disposed in the lowermost layer of the flooring, it is preferable that each fiber has a high degree of freedom in order to obtain good impact relaxation and impact dispersion Therefore, the fiber adhesion rate by fusion of the wet heat adhesive fibers of the fibers constituting the nonwoven fiber structure is preferably in the range of 3 to 70%, and preferably in the range of 10 to 50%. More preferred. Here, the “fiber adhesion rate” indicates the ratio of the number of cross sections of two or more fibers bonded to the number of cross sections of all the fibers in the cross section of the nonwoven fiber structure. Therefore, a low fiber adhesion rate means that a ratio of a plurality of fibers fused to each other (a ratio of fibers fused by fusing) is small.

  The fibers constituting the non-woven fiber structure are bonded at the contact points of the respective fibers, but in order to develop a large bending stress with as few contacts as possible, the bonding points are formed along the thickness direction. It is preferable that the structure is uniformly distributed from the surface of the structure to the inside (center) and the back surface. When the adhesion points are concentrated on the surface or inside, it is difficult not only to ensure excellent mechanical properties and moldability, but also the shape stability in the portion where the adhesion points are small.

  Therefore, in the cross section in the thickness direction of the non-woven fiber structure, it is preferable that the fiber adhesion rate in each region divided in three in the thickness direction is within the above range. Furthermore, the ratio of the minimum value to the maximum value of the fiber adhesion rate in each region (minimum value / maximum value) (ratio of the minimum region to the region with the maximum fiber adhesion rate) is preferably 50% or more, more preferably 55. -99%, particularly preferably 60-98%. Non-woven fiber structure with excellent hardness, bending strength, folding resistance and toughness, despite the low bonding area of the fibers, because the fiber adhesion rate has such uniformity in the thickness direction You can get a body. In addition, the non-woven fiber structure as described above bends without being bent when it is gradually bent, and further retains without causing an extreme load drop even if it is bent beyond the point showing the maximum bending load. In addition, it has a property (hardness to break) that tends to be restored when the load is released and that a clear crease with permanent distortion hardly occurs. Further, since the bonding area of the fibers is low, there are many fibers that can vibrate freely and have excellent vibration and sound absorption properties.

  The nonwoven fibrous structure containing wet heat adhesive fibers has a temperature of 70 to 150 ° C. (more preferably 80 to 120 ° C.) with respect to a web (for example, semi-random web, parallel web, etc.) obtained using staple fibers. ) At a pressure of 0.1 to 2 MPa (more preferably 0.2 to 1.5 MPa).

  The plate materials 2, 2a, 2b used for the floor materials 1, 1 ', 1' 'of the present invention are not particularly limited as to the forming material thereof, as long as the plate material has the product of the flexural modulus and thickness described above. For example, a plywood, a resin plate, an iron plate, a foam, a corrugated cardboard, a honeycomb formed body, and the like can be given.

  As the surface material 4 used for the floor material 1, 1 ', 1' 'of the present invention, those conventionally used as the surface material of the floor material can be used without any particular limitation, for example, a tatami mat, a vinyl chloride floor. Suitable examples include grooved flooring, carpets, carpets, tiles, cushion flooring and the like.

  In the floor material thus obtained, the compression modulus of the uppermost layer is 100 to 2500 kPa, and the thickness change amount when the entire floor material is loaded with 60 kg is 0.5 to 1.8 mm. When the amount of change is 1.8 mm or less, the foot comfort is good, but when it is larger than 1.8 mm, the floor becomes a fluffy floor and the foot comfort is not good. As for sitting comfort, when the amount of change is 0.5 mm or more, there is a good cushion feeling, but when the amount of change is less than 0.5 mm, pain occurs when the knee or elbow is placed on the floor. It becomes easy to feel. The present invention is such a flooring in which a buffer layer is arranged on each of the upper side and the lower side of the plate, and the compression elastic modulus of the buffer layer arranged in the uppermost layer is 100 to 2500 kPa, and 60 kg of the whole flooring The present invention also provides an impact mitigating floor material having a thickness change amount under load of 0.5 to 1.8 mm. In such a floor material of the present invention, suitable physical property values, materials, etc. are the same as described above. It is.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these at all.

<Example 1>
A flooring sample having a three-layer structure of buffer layer 3a (thickness: 1.0 mm) / plate material 2 (thickness: 5.5 mm) / buffer layer 3b (thickness: 10.1 mm) as shown in FIG. 1 is prepared. (100 cm × 100 cm).

The buffer layer 3a is a core sheath in which the core component is polyethylene terephthalate and the sheath component is an ethylene-vinyl alcohol copolymer (ethylene content: 44 mol%, saponification degree: 98.4 mol%) as wet heat adhesive fibers. Type composite staple fiber (Sofista, manufactured by Kuraray Co., Ltd.), fineness: 3.3 dtex, fiber length: 51 mm, core-sheath mass ratio = 50/50, number of crimps: 21/25 mm, crimp ratio: 13.5% ) Was prepared. Using this core-sheath type composite staple fiber, a card web having a basis weight of about 100 g / m ² was produced by a card method. The card web was transferred to a belt conveyor equipped with a 50 mesh, 500 mm wide stainless steel endless net. In addition, the belt conveyor which has the same metal mesh is equipped in the upper part of the metal mesh of this belt conveyor, and each used the belt conveyor which can adjust the space | interval of these metal meshes arbitrarily, rotating in the same direction at the same speed. . Next, the card web is introduced into a steam spraying device provided in the lower conveyor, and steam treatment is performed by ejecting (vertically) 0.25 MPa high-temperature steam from the device in the thickness direction of the card web. As a result, a molded body having a non-woven fiber structure was obtained. In this steam spraying device, a nozzle is installed in the lower conveyor so as to spray high-temperature steam toward the web via a conveyor net, and a suction device is installed in the upper conveyor. Further, another jetting device, which is a combination of the arrangement of the nozzle and the suction device reversed, is installed on the downstream side in the web traveling direction of this jetting device, and steam treatment is performed on both the front and back sides of the web. did. In addition, the hole diameter of the water vapor | steam injection nozzle was 0.3 mm, and the vapor | steam injection apparatus with which the nozzle was arranged in 1 row at 1 mm pitch along the width direction of the conveyor was used. The processing speed is 10 m / min, and the interval (distance) between the upper and lower conveyor belts on the nozzle side and the suction side is a non-woven fiber structure having a thickness (measured in accordance with JIS L1913 “General Short Fiber Nonwoven Fabric Testing Method”) of 1 mm. It was adjusted so that the body was obtained. The nozzles were arranged on the back side of the conveyor belt so as to be almost in contact with the belt. The obtained non-woven fiber structure (molded body) had a board-like form and was very hard as compared with a general nonwoven fabric. It was calculated from the above thickness measured according to JIS L1913 “General Short Fiber Nonwoven Fabric Test Method” and the basis weight (104 g / m ² ) measured according to JIS L1913 “General Short Fiber Nonwoven Fabric Test Method”. The apparent density was 0.10 g / cm ³ . Furthermore, the fiber adhesion rate was 28.4% on the front surface side, 27.2% on the center portion, and 28.6% on the back surface side.

  The fiber adhesion rate was calculated as follows. Using a scanning electron microscope (SEM), a photograph in which the cross section of the structure was magnified 100 times was taken. The photograph of the cross section in the thickness direction of the photographed structure is divided into three equal parts in the thickness direction, and the number of fiber cut surfaces (fiber end faces) that can be found in each of the three divided areas (front surface, inside (center), back surface) On the other hand, the ratio of the number of cut surfaces where the fibers are bonded to each other was determined. Of the total number of fiber cross-sections that can be found in each region, the ratio of the number of cross-sections in the state where two or more fibers are bonded is expressed as a percentage based on the following formula. In addition, in the part which fibers contact, there exists a part which is simply contacting, without melt | fusion, and a part which has adhere | attached by melt | fusion. However, by cutting the structure for microscopic photography, the fibers in contact with each other are separated from each other by the stress of each fiber on the cut surface of the structure. Therefore, in the cross-sectional photograph, it can be determined that the contacting fibers are bonded to each other.

Fiber adhesion rate (%) = (number of cross sections of fibers bonded two or more) / (total number of cross sections of fibers) × 100
However, for each photograph, all the fibers with a visible cross section were counted, and when the number of fiber cross sections was 100 or less, a photograph to be observed was added so that the total fiber cross section exceeded 100. In addition, the fiber adhesion rate was calculated | required about each area | region divided into three equally, and the ratio (minimum value / maximum value) of the minimum value with respect to the maximum value was calculated | required collectively.

  This nonwoven fiber structure was cut into a size of 100 cm × 100 cm and used as the buffer layer 3a. It was 359 kPa when the compression elastic modulus was measured about the obtained buffer layer 3a based on JISK7181.

For the buffer layer 3b, a non-woven fiber produced in the same manner as described above for the buffer layer 3a, except that 10 card webs of about 100 g / m ² were stacked to form a card web of about 100 g / m ^{2 in} total. A structure was used. The buffer layer 3b had a compression elastic modulus of 347 kPa, a thickness of 10.1 mm, and an apparent density of 0.10 g / cm ³ . Furthermore, the fiber adhesion rate was 34.9% on the front surface side, 31.8% on the central portion, and 33.7% on the back surface side.

As the plate material 2, a plywood having a thickness (C) of 5.5 mm (ordinary plywood, manufactured by Corindo Group) was used. The bending elastic modulus (A) of the plywood is 5.2 × 10 ³ MPa (measured in accordance with JIS K 7171, the test piece width is 10 mm, the length is 100 mm, the distance between fulcrums is 80 mm, and the test speed is 10 mm. ), Surface density (B) is 2.6 kg / m ² , product (D) of flexural modulus (A) and thickness (C) is 2.9 × 10 ⁴ , surface density and bending The product of elastic modulus and thickness (product of (B) and (D)) was 7.4 × 10 ⁴ .

<Example 2>
As the buffer layer 3b disposed in the lowermost layer, the same procedure as in Example 1 was used except that a non-woven fiber structure having a compression elastic modulus of 378 kPa, a thickness of 5.0 mm, and an apparent density of 0.11 g / cm ³ was used. A flooring sample was created. The fiber adhesion rate was 38.3% on the front side, 37.1% on the center, and 39.3% on the back side.

<Example 3>
As the buffer layer 3b disposed in the lowermost layer, the same procedure as in Example 1 was used except that a non-woven fiber structure having a compression elastic modulus of 35 kPa, a thickness of 10.5 mm, and an apparent density of 0.05 g / cm ³ was used. A flooring sample was created. The fiber adhesion rate was 18.2% on the front surface side, 16.8% on the center portion, and 17.9% on the back surface side.

<Example 4>
As the buffer layer 3a disposed on the upper side of the plate material, the same as Example 1 except that a non-woven fiber structure having a compression modulus of 2088 kPa, a thickness of 1.0 mm, and an apparent density of 0.15 g / cm ³ was used. A flooring sample was prepared. The fiber adhesion rate was 63.3% on the front side, 61.1% on the center, and 64.3% on the back side.

<Example 5>
A floor sample was prepared in the same manner as in Example 1 except that an iron plate having a thickness (C) of 1.5 mm was used as the plate 2. The bending elastic modulus (A) of the iron plate is 2.0 × 10 ⁵ MPa, the surface density (B) is 9.7 kg / m ² , and the product (D) of the bending elastic modulus (A) and the thickness (C) is 3. 0 × 10 ^5, (the product of (B) and (D)) the product of the surface density and the bending elastic modulus and the thickness was 2.9 × 10 ^6.

<Example 6>
As the buffer layer 3a disposed on the upper side of the plate member 2, polyethylene terephthalate staple fibers (Tetron T471, manufactured by Toray Industries, Inc.), fineness: 1.6 dtex, fiber length: 51 mm, crimp number: 12.5 / 25 mm, wrinkles (Reduction ratio: 14.0%) was prepared. Using this staple fiber, a card web of about 100 g / m ^{2 is formed} by a card method, and a polyester nonwoven fabric (compression elastic modulus: 411 kPa, apparent density: 0) is formed by a needle punch method (number of punches: 200 times / cm ² ). .12 g / cm ³ ). As a buffer layer 3b disposed in the lowermost layer, 10 card webs of about 100 g / m ² similar to the buffer layer 3a are stacked and a polyester nonwoven fabric having a thickness of 9.8 mm (compression elastic modulus: 405 kPa, apparent density: 0.10 g). / Cm ³ ), the same plywood used in Example 1 as the plate material 2 was used to prepare a flooring sample.

<Example 7>
A resin foam having a thickness of 1.0 mm (Sanperca L1400, manufactured by Sanwa Processing Co., Ltd.) (compression elastic modulus: 560 kPa, apparent density: 0.07 g / cm ³ ) as the buffer layer 3 a disposed on the upper side of the plate member 2, Resin foam (Sambelka L2000, manufactured by Sanwa Kagaku Co., Ltd.) (compressed elastic modulus: 440 kPa, apparent density: 0.05 g / cm ³ ), plate material 2 as the buffer layer 3b disposed in the lowermost layer A flooring sample was prepared using the same plywood as used in Example 1.

<Comparative Example 1>
Only the nonwoven fiber structure used as the buffer layer 3b in Example 1 was used as a flooring sample.

<Comparative example 2>
A flooring sample was prepared in the same manner as in Example 1 except that the buffer layer 3a was not disposed on the upper side of the plate 2.

<Comparative Example 3>
A flooring sample was prepared in the same manner as in Example 1 except that the lowermost buffer layer 3b was not disposed.

<Comparative example 4>
A non-woven fiber structure was prepared in the same manner as in Example 1 except that the thickness was 0.2 mm using a card web of about 20 g / m ² , and the obtained non-woven fiber structure (compression elastic modulus: 326 kPa). , Apparent density: 0.10 g / cm ³ ) was used in the same manner as in Example 1 except that the buffer layer 3a disposed on the upper side of the plate material was used. The fiber adhesion rate was 28.9% on the front side, 28.2% on the center, and 29.6% on the back side.

<Comparative Example 5>
A nonwoven fibrous structure was prepared in the same manner as in Example 1 except that five card webs of about 100 g / m ² were stacked to make about 500 g / m ² and the thickness was 5.0 mm. A flooring sample was prepared in the same manner as in Example 1 except that a fiber structure (compression elastic modulus: 357 kPa, apparent density: 0.10 g / cm ³ ) was used as the buffer layer 3 a disposed on the upper side of the plate. did. The fiber adhesion rate was 26.4% on the front side, 25.7% at the center, and 26.3% on the back side.

<Comparative Example 6>
A nonwoven fiber structure having a thickness of 10.0 mm was prepared in the same manner as in Example 1 except that a card web of about 20 g / m ² was used, and the resulting nonwoven fiber structure (compression elastic modulus: 5 kPa, A floor sample was prepared in the same manner as in Example 1 except that the apparent density: 0.02 g / cm ³ ) was used as the buffer layer 3b disposed in the lowermost layer. The fiber adhesion rate was 10.8% on the front side, 9.4% at the center, and 10.3% on the back side.

<Comparative Example 7>
A non-woven fiber structure having a thickness of 10 mm was prepared in the same manner as in Example 1 except that 20 card webs of about 100 g / m ² were stacked to make about 2000 g / m ^2. A flooring sample was prepared in the same manner as in Example 1 except that (compression elastic modulus: 2368 kPa, apparent density: 0.20 g / cm ³ ) was used as the buffer layer 3b disposed in the lowermost layer. The fiber adhesion rate was 71.2% on the front side, 70.6% at the center, and 74.2% on the back side.

<Comparative Example 8>
A flooring sample was prepared in the same manner as in Example 1 except that a vinyl chloride plate material (Takiron plate TS608A, manufactured by Takiron Co., Ltd.) having a thickness (C) of 1.8 mm was used as the plate material 2. The plate material made of vinyl chloride has a flexural modulus (A) of 3.2 × 10 ³ MPa, an area density (B) of 2.3 kg / m ² , and a product of flexural modulus (A) and thickness (C) (D ) Was 5.7 × 10 ³ , and the product of surface density, flexural modulus and thickness (product of (B) and (D)) was 1.3 × 10 ⁴ .

<Comparative Example 9>
A floor sample was prepared in the same manner as in Example 1 except that a foam plate material (Styrofoam IB, manufactured by Dow Chemical Co., Ltd.) having a thickness (C) of 10 mm was used as the plate material 2. The flexural modulus (A) of the foam plate material is 0.4 MPa, the surface density (B) is 0.3 kg / m ² , and the product (D) of the flexural modulus (A) and the thickness (C) is 4.0. The product of the surface density, the flexural modulus and the thickness (the product of (B) and (D)) was 1.2.

(Evaluation)
The following items were evaluated for the samples of the flooring materials obtained in the examples and comparative examples.

(1) Impact relaxation properties As shown schematically in FIG. 4, a rubber plate 11 (Shore A hardness 38) is placed on the upper side of the flooring sample, and the impact relaxation properties (falling impact) in accordance with the provisions of JIS A6519. G value) was measured.

(2) Step comfort (walking feeling), sitting comfort (thickness change under load)
The amount of change in thickness when a constant load was applied to the flooring sample was measured. As the load, a pressure plate having a diameter of 100 mm and a weight of 60 kg placed thereon was used.

  The results are shown in Tables 1 and 2.

  1, 1 ', 1 "Floor material, 2, 2a, 2b Plate material, 3a, 3b, 3c, 3d Buffer layer, 4 Surface material, 11 Rubber plate, 12 Sensor.

Claims (7)

A floor provided with a buffer layer disposed in the lowermost layer, a plate disposed adjacent to the upper side of the buffer layer, and a buffer layer disposed in the uppermost layer opposite to the buffer layer through the plate. Material,
The buffer layer disposed in the uppermost layer has a compression elastic modulus of 100 to 2500 kPa and a thickness of 0.5 to 4 mm.
The buffer layer disposed in the lowermost layer has a compression elastic modulus in the range of 10 to 500 kPa,
The plate material is an impact mitigating floor material in which the product of the flexural modulus and the thickness is 1.0 × 10 ⁴ or more.   The impact-reducing flooring material according to claim 1, wherein the total thickness is 60 mm or less. The shock absorbing flooring according to claim 1 or 2, wherein the buffer layer disposed in the uppermost layer has an apparent density in the range of 0.08 to 0.2 g / cm ³ . The buffer layer disposed in the lowermost layer has a thickness of 5 to 50 mm and an apparent density in the range of 0.03 to 0.15 g / cm ^3. The listed impact mitigation flooring. The plate material has a surface density of 2 kg / m ² or more, a product of the surface density, a flexural modulus, and a thickness of 3.0 × 10 ⁴ or more, and a thickness of 1 to 20 mm. 5. The impact-reducing flooring material according to any one of 4 above.   The impact-reducing flooring material according to any one of claims 1 to 5, wherein the buffer layer is a non-woven fiber structure.   A flooring material in which a buffer layer is disposed on each of the upper side and the lower side of the plate material, and the compression elastic modulus of the buffer layer disposed on the uppermost layer is 100 to 2500 kPa, and the thickness change amount of the entire flooring material at a load of 60 kg is 0. An impact mitigating floor material that is 5 to 1.8 mm.

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