Cushioning material

Abstract

The invention relates to a cushioning material. The purpose of the present invention is to provide a highly durable cushioning material that is unlikely to deform. A cushioning material (1) is provided with a first cushioning body (2) and a second cushioning body (3) that is arranged above the first cushioning body (2) and covers at least the upper surface of the first cushioning body (2), and is characterized in that the first cushioning body (2) comprises a three-dimensional network structure obtained by irregularly and locally welding continuous lines of a thermoplastic resin to form a loop, and the second cushioning body (3) is arranged above the first cushioning body (2) and covers at least the upper surface of the first cushioning body (2). The second buffer body (3) is configured from a longitudinal nonwoven fabric in which fibers are oriented in the thickness direction.

Description

[0001] This application is a divisional application of the parent application whose applicant is "Xijin Co., Ltd.", whose invention name is "Buffer Material", whose application date is "March 01, 2021", and whose application number is "202180018377.8". Technical Field

[0002] The present invention relates to a cushioning material used as a vehicle seat or a mattress for vehicles, trains, airplanes, etc. Background Art

[0003] In the past, most vehicle seats used lightweight, easy to mass-produce, and inexpensive polyurethane seats as cushioning materials. However, in recent years, it has been recognized that the gas produced when polyurethane is burned is toxic, and there have been efforts to reduce the use of polyurethane around the world. Specifically, the EU standard EN45545 will also be adopted from 2020, and it is necessary to develop durable, lightweight, and environmentally friendly vehicle seats that can replace polyurethane as soon as possible.

[0004] In addition, although the cushioning material made of polyurethane has excellent durability, it has the problem of poor water permeability and easy to get stuffy.

[0005] Therefore, vehicle seats using materials that replace polyurethane have been studied. Patent Document 1 discloses a seat that includes a back portion and a seat portion formed by a fabric, a cushion layer, and a back deep-drawn portion. The seat is characterized in that the cushion layer is made of a material having an apparent density of 0.01 g / cm 3 ~0.2g / cm 3 The mesh body is composed of a thermoplastic elastic resin of a three-dimensional structure formed by bending and contacting continuous lines with a fineness of less than 100,000 deniers to form a mostly fused three-dimensional structure, and the resin molded body is integrally joined to the mesh body.

[0006] Patent document 2 discloses a vehicle seat having a detachable seat cushion and a recessed portion of the same shape as the seat cushion. In the detachable seat cushion, a fiber structure is covered with a fiber cover, and the longitudinal / lateral ratio (T / W ratio) of the fibers constituting the fiber structure is 1.5 or more. The following is disclosed: Such a seat cushion is detachably provided on a polyurethane vehicle seat having a recessed portion.

[0007] Patent document 3 discloses a vehicle seat, wherein the seat portion includes a cushion layer, the cushion layer having a laminated structure of (i) a three-dimensional mesh structure in which lines made of thermoplastic elastic resin form loops so that most of the contact portions are joined, and (ii) a nonwoven fabric made of thermoplastic resin fibers joined, (ii) the nonwoven fabric being located on the seat surface side, the vehicle seat being characterized in that (i) the three-dimensional mesh structure has a structure in which the cut ends of at least two surfaces facing each other in the thickness direction are compressed and joined. In addition, the following is disclosed: the nonwoven fabric is produced by mixing and opening thermal bonding fibers and short fibers made of thermoplastic inelastic resin to form a three-dimensional structure, and most of the contact portions are joined and integrated by thermal bonding components.

[0008] Patent document 4 discloses a vehicle seat with a cushioning filler, the cushioning filler being formed by a net, wherein the net is a fiber net formed by dispersing and mixing as a bonding component a thermoplastic elastomer having a melting point 40°C or more lower than the melting point of the polyester polymer constituting the short fibers, and an elastic composite fiber consisting of an inelastic polyester and the former being exposed on at least the fiber surface, in a base fiber consisting of an aggregate of inelastic polyester-based crimped short fibers, and wherein when the total number of fibers along its length direction is A and the total number along the transverse direction is B, the condition A>3B / 2 is satisfied. In the cushioning filler, the fiber net is folded in sequence in a forest state along its length direction, and at this time, in the fiber net, there are distributed (a) flexible heat-bonding points formed by heat-melting the elastic composite fibers when they cross each other, and (b) flexible heat-bonding points formed by heat-melting the elastic composite fibers and the inelastic polyester-based short fibers when they cross each other.

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 8-10470

[0010] Patent Document 2: Japanese Patent Application Publication No. 2018-193042

[0011] Patent Document 3: Japanese Patent Application Publication No. 2003-260278

[0012] Patent Document 4: Japanese Patent Application Laid-Open No. 8-318066

[0013] However, in the seat of Patent Document 1, since it is composed only of a three-dimensional mesh structure, there is a problem of feeling a bumpy touch. In addition, the deformation is large and the durability is insufficient. In addition, in the seat of Patent Document 2, the area of ​​the front end of the seat located under the thigh when the user sits down is made of polyurethane, so there are problems of insufficient air permeability and less polyurethane reduction. The seat of Patent Document 3 is a laminate of non-woven fabric and mesh structure, but the non-woven fabric used as the upper layer is obtained by mixing and defibration of thermal bonding fibers and short fibers composed of thermoplastic resin to form a three-dimensional structure, and its deformation resistance and durability are insufficient. In addition, since the cut ends of the non-woven fabric of the upper layer and the mesh structure of the lower layer are compressed and joined, there is also a problem of limited product shape. In the seat of Patent Document 4, since it is composed only of a fiber structure formed by fibers oriented in the thickness direction, the cushioning and support force of the buttocks are insufficient. In addition, the shape retention of the front area of ​​the seat, especially where a load is applied, is low, and the durability is insufficient. Summary of the invention

[0014] Therefore, an object of the present invention is to provide a cushioning material which improves cushioning properties and seating comfort, is difficult to deform, and has high durability.

[0015] The cushioning material of the present invention is characterized in that it comprises: a first cushioning body; and a second cushioning body, which is arranged above the first cushioning body and covers at least the upper surface of the first cushioning body, the first cushioning body contains a three-dimensional network structure, and the three-dimensional network structure is obtained by irregularly and locally welding continuous lines of thermoplastic resin to form rings, and the second cushioning body is composed of a longitudinal non-woven fabric in which fibers are oriented in the thickness direction.

[0016] Here, "fibers are oriented in the thickness direction" means that when the total number of fibers arranged longitudinally parallel to the thickness direction of the nonwoven fabric is (X) and the total number of fibers arranged transversely perpendicular to the thickness direction of the nonwoven fabric is (Y), X is greater than Y. In addition, the longitudinal / transverse ratio (X / Y ratio) of the fibers constituting the longitudinal nonwoven fabric 3 is preferably 1.5 or more, and more preferably 2.0 to 8.0.

[0017] Preferably, the cushioning material is used for a vehicle seat, the longitudinal nonwoven fabric has a pleated structure, and has a high-density portion having a higher bulk density than the inner portion in a front region of the vehicle seat.

[0018] Preferably, the 25% compression hardness of the longitudinal nonwoven fabric is smaller than that of the three-dimensional network structure.

[0019] Preferably, the cushioning material is used for a vehicle seat, and the first cushioning body is fitted into a groove provided on a lower surface of the second cushioning body to be integrally formed.

[0020] Preferably, in the second buffer body, the area forward of the front surface of the first buffer body is a high-density portion having a higher packing density than other areas. Thus, by maintaining the cushioning property of the front area without the three-dimensional mesh structure and ensuring the thickness of the high-density portion of the second buffer body, the shape retention can also be improved.

[0021] Preferably, the cushioning material is used for a vehicle seat, and a spring receiving member is provided below the first cushioning body and the second cushioning body.

[0022] Preferably, the spring receiving member is made of a material having a bulk density of 0.5 to 0.01 g / cm 3 , a three-dimensional network structure with a thickness of 0.5 to 25 mm, wherein the three-dimensional network structure is obtained by irregularly and locally welding continuous lines of thermoplastic resin to form rings, and the stacking density of the three-dimensional network structure constituting the spring supporting member is higher than the stacking density of the three-dimensional network structure contained in the first buffer body.

[0023] Preferably, the above-mentioned cushioning material is used for vehicle seats, and the three-dimensional network structure contained in the above-mentioned first cushioning body has a dense structure in which sparse parts and dense parts extending along the width direction of the vehicle seat are repeatedly arranged in the front-to-back direction, and the above-mentioned dense part is provided in the middle part in the front-to-back direction of the vehicle seat.

[0024] Preferably, the first buffer body is composed of multiple layers, including a three-dimensional network structure as an upper layer, and a second longitudinal nonwoven fabric as a layer located below the upper layer, and the stacking density of the second longitudinal nonwoven fabric is higher than that of the longitudinal nonwoven fabric constituting the second buffer body.

[0025] Preferably, the first shock absorbing body is composed of a plurality of layers including a three-dimensional network structure as an upper layer and a nonwoven fabric in which fibers are oriented in a transverse direction as a layer located below the upper layer.

[0026] Preferably, the first buffer body is composed of a plurality of layers including a three-dimensional network structure as an upper layer and a polyurethane foam as a layer located below the upper layer.

[0027] Preferably, the cushioning material is used for a mattress, the second cushioning body has a sparse-dense structure in which sparse portions and dense portions extending in the width direction are repeatedly arranged in the longitudinal direction of the mattress, and the dense portion is provided in the middle portion of the mattress.

[0028] Preferably, the cushioning material is used for a mattress, the first cushioning body comprises a surface layer, an upper layer, and a base layer, the surface layer has a higher bulk density than the upper layer and the base layer, and the base layer has a higher bulk density than the upper layer.

[0029] Preferably, the second buffer body is included in a covering cover that covers at least an upper surface of the first buffer body.

[0030] In the present invention, a longitudinal nonwoven fabric is arranged in the cushioning material at the part located on the buttocks and thigh side when the user sits, and a three-dimensional mesh structure is provided thereunder, so that even if the seat is used for a long time, the deformation of the upper surface and the front area of ​​the seat can be suppressed, and the overall air permeability of the seat can be improved. In addition, by virtue of the elasticity of the three-dimensional mesh structure itself, the supporting force of the buttocks and the like is increased, and fatigue is not easy. In addition, when the cushioning material is used for vehicle seats, a high-density portion is formed in the front area of ​​the longitudinal nonwoven fabric to improve shape retention and durability, and the sitting comfort can also be improved. In addition, the amount of polyurethane used can be reduced, and the burden on the environment can also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a perspective view of the shock absorbing body (vehicle seat) according to the first embodiment.

[0032] Figure 2 It is a XX cross-sectional view of the shock absorbing body (vehicle seat) according to the first embodiment.

[0033] Figure 3 It is a cross-sectional view taken along the line XX of the cushioning body (vehicle seat) according to the second embodiment.

[0034] Figure 4 It is a cross-sectional view taken along the line XX of a cushioning body (vehicle seat) according to a third embodiment.

[0035] Figure 5 It is a longitudinal cross-sectional view of a cushioning body (mattress) according to a fourth embodiment.

[0036] Figure 6 It is a longitudinal cross-sectional view of a modification of the cushioning body (mattress) according to the fourth embodiment.

[0037] Figure 7 It is a figure explaining the use state of the cushioning body (mattress) of 4th Embodiment.

[0038] Figure 8 It is a longitudinal cross-sectional view of a cushioning body (mattress) according to a fifth embodiment. DETAILED DESCRIPTION

[0039] Reference Figure 1-2The vehicle seat 1 (cushion material) of the first embodiment of the present invention is described. The vehicle seat 1 comprises: a three-dimensional mesh structure 2 as a first cushioning body; a longitudinal nonwoven fabric 3 as a second cushioning body arranged to be laminated on the top of the first cushioning body; and a spring receiving member 4. The longitudinal nonwoven fabric 3 has a shape in which the thickness becomes thinner in the front area. A three-dimensional mesh structure 2 having the same shape as the groove 32 is embedded in a groove 32 formed on the lower surface of the longitudinal nonwoven fabric 3, and the spring receiving member 4 is arranged in a manner of abutting against the three-dimensional mesh structure 2 and the lower surface of the longitudinal nonwoven fabric 3, and the whole is covered with a covering cover (not shown) composed of cotton cloth, nonwoven fabric, etc.

[0040] The three-dimensional mesh structure 2 is in the shape of a roughly rectangular parallelepiped, and the groove 32 has an inner shape that is roughly the same as its outer shape. When the three-dimensional mesh structure 2 is embedded in the groove 32 of the longitudinal nonwoven fabric 3, the front and rear sides, left and right sides, and the entire upper surface of the three-dimensional mesh structure 2 are in contact with and covered by the longitudinal nonwoven fabric 3, and the lower surfaces of the three-dimensional mesh structure 2 and the longitudinal nonwoven fabric 3 become one surface. The thickness of the longitudinal nonwoven fabric 3 is preferably 5 to 150 mm, and the thickness of the three-dimensional mesh structure 2 is preferably 5 to 140 mm.

[0041] The longitudinal nonwoven fabric 3 includes short fibers and thermally adhesive fibers, and the fibers are longitudinally oriented in the thickness direction of the longitudinal nonwoven fabric 3. "The fibers are arranged longitudinally in the thickness direction" means that when the total number of fibers arranged longitudinally parallel to the thickness direction of the nonwoven fabric is (X) and the total number of fibers arranged transversely perpendicular to the thickness direction of the nonwoven fabric is (Y), X is greater than Y. In addition, the longitudinal / transverse ratio (X / Y ratio) of the fibers constituting the longitudinal nonwoven fabric 3 is preferably 1.5 or more, and more preferably 2.0 to 8.0. For the ratio of the total number of longitudinal fibers (X) to the total number of transverse fibers (Y), the longitudinal nonwoven fabric 3 is cut in the thickness direction, and the number of fibers arranged parallel to the thickness direction (0° to 45°) and the number of fibers arranged perpendicular to the thickness direction (45 to 90°) are observed on the cross section under a microscope, so that their ratio can be calculated.

[0042] In order to obtain such a longitudinal nonwoven fabric 3, a conventionally known method may be used, but the following method is exemplified: for example, short fibers and thermally adhesive short fibers are mixed, and a uniform web is woven using a roller carding machine, and then the web is folded into a pleated shape using a known heat treatment machine, and in the folded state, a heat treatment is performed to form a fixing point based on heat fusion. Generally, most of the fibers constituting the web are arranged along the plane direction of the web, so by continuously folding them into a pleated shape for lamination, most of the fibers can be arranged in the thickness direction. In more detail, as a method for manufacturing the longitudinal nonwoven fabric 3, it can be manufactured by folding it into a zigzag shape using a struto device (registered trademark, a nonwoven fabric manufacturing device described in the specification of European Patent Application Publication No. 0350627), or an air-laid web machine (for example, V21 / R-K12, V21 / K12 produced by FEILER), etc., and then compressing and heat-treating it. The fiber length of the short fibers used for the longitudinal nonwoven fabric 3 is preferably in the range of 30 to 100 mm. In addition, the longitudinal nonwoven fabric 3 may have a pleated structure or a fiber structure obtained by repeatedly performing a process of stacking short fibers in a rectangular shape.

[0043] The longitudinal nonwoven fabric 3 of the present embodiment is a structure having a structure in which the nonwoven web is folded in a pleated manner, and the folding direction is the front-rear direction of the vehicle seat 1 .

[0044] As the short fibers constituting the longitudinal nonwoven fabric 3, natural fibers such as cotton and wool, inorganic fibers such as carbon fibers, synthetic fibers such as polyolefins and polyesters, etc. can be used. As the thermal adhesive fibers, synthetic fibers having a melting point 40 degrees or more lower than that of the short fibers are preferred. The bulk density of the longitudinal nonwoven fabric 3 is preferably 0.005 to 0.50 g / cm 3 .

[0045] The longitudinal nonwoven fabric 3 has a sparse structure with a sparse part and a dense part in the front-to-back direction. Specifically, the area in front of the seat has a high-density part 31 with a higher bulk density than other places. The bulk density of the high-density part 31 is preferably 0.01 to 0.50 g / cm 3. In the present embodiment, the area in front of the front side of the three-dimensional mesh structure 2 is set as the high-density portion 31, and there is no high-density portion 31 directly above the three-dimensional mesh structure 2. The high-density portion 31 extends in the width direction of the vehicle seat 1. The density of the longitudinal non-woven fabric 3 can be changed, for example, by changing the folding density of the fiber sheet during manufacturing. Since it is provided with the high-density portion 31, the shape retention of the front area, which is easily loaded and the shape is easily collapsed, can be improved, and the cushioning performance can also be improved. The high-density portion 31 is not limited to the front. From the perspective of shape retention, it is also preferred to have a high-density portion 31 on the left and right side portions and the rear side portion of the longitudinal non-woven fabric 3. In addition, it is also possible to have a dense structure in which a dense portion with a high stacking density and a sparse portion with a low stacking density repeatedly appear in one of the thickness direction, the front-back direction, and the left-right direction, or a combination thereof.

[0046] The entire surface of the seat surface of the vehicle seat 1 is composed of the longitudinal nonwoven fabric 3, so that the ventilation is good, and the user does not have to worry about being stuffy even if he sits for a long time. In addition, the longitudinal nonwoven fabric 3 has elasticity compared to the flat nonwoven fabric with fibers arranged horizontally, and the user feels good and relaxed when sitting. In addition, the longitudinal nonwoven fabric 3 has strong tolerance to "deformation" caused by the load from above, especially, and can maintain durability even if the user is in the part where the buttocks and the back of the thighs of the legs are most loaded when sitting. In addition, the longitudinal nonwoven fabric 3 is perpendicular to the pressure surface, so when the user sits and the load is applied, it is deformed in units of points and deforms along the user's body, so the body pressure dispersion is excellent, and it is not easy to get tired even if sitting for a long time.

[0047] The three-dimensional network structure 2 is a structure formed by irregularly partially welding continuous lines of thermoplastic resin with a line diameter (diameter) of 0.3 mm to 1.5 mm to form a ring. The bulk density (apparent density) is an important factor that determines the soft and high resilience, and can be designed as needed, preferably 0.025 g / cm 3 ~0.2g / cm 3 , more preferably 0.04 g / cm 3 ~0.09g / cm 3 If the bulk density is less than 0.025g / cm 3 If it exceeds 0.20g / cm 3 It is not suitable as a vehicle seat.

[0048] The raw material of the three-dimensional network structure 2, i.e., the thermoplastic resin, preferably includes polyethylene thermoplastic resin, polypropylene thermoplastic resin, polyester thermoplastic elastomer, polypropylene thermoplastic elastomer, a mixture of polyethylene thermoplastic resin and polyethylene thermoplastic elastomer, PVC, polyurethane elastomer, nylon elastomer, polystyrene elastomer, etc.

[0049] For a detailed method of manufacturing the three-dimensional network structure 2 used in the present invention, please refer to the publications of the patent applicants such as Japanese Patent No. 4350286 and US Patent No. 7625629.

[0050] The three-dimensional network structure 2 has the following sparse and dense structure: having a relatively high packing density δ 1 The dense part 21 has a relatively low bulk density δ 2 The sparse parts 22 are repeated alternately in the front-to-back direction of the seat. In this embodiment, a dense part 21 extending in the width direction is formed in the middle part of the front-to-back direction of the seat, and sparse parts 22 are formed in front and behind the dense part 21. In particular, the bulk density of the dense part 21 is preferably 0.03 to 0.10 g / cm 3 The bulk density of the sparse part is preferably 0.01 to 0.08 g / cm 3 In particular, since the dense portion 21 is provided in the area to which the load is applied, the cushioning, durability and sitting comfort are improved. The sparse and dense structure can be formed by making the extrusion direction of the three-dimensional mesh structure 2 as the front-rear direction of the seat during manufacture, so that the speed of the roller or the crawler is variable.

[0051] As a modification, the three-dimensional network structure 2 may further have a sparse / dense structure in the thickness direction and the left / right direction. In addition, for example, it may be formed on four sides so as to have a surface layer with a higher packing density than the inside on the upper surface, the lower surface, and the left and right sides.

[0052] Next, the spring receiving member 4 will be described. The spring receiving member 4 has a function of preventing a rod-shaped spring in a seat frame disposed below the vehicle seat 1 from biting into the vehicle seat 1 .

[0053] In the present embodiment, the spring receiving member 4 is a three-dimensional network structure formed by irregularly partially welding continuous lines of thermoplastic resin having a line diameter (diameter) of 0.3 mm to 1.5 mm to form a ring, but has a bulk density δ of the three-dimensional network structure 2 as the first cushioning material. 1 ,δ 2 The spring receiving member 4 preferably has a bulk density of 0.5 to 0.01 g / cm 3The hardness of the spring receiving member 4 can be adjusted by changing the fineness, bulk density, raw material, and structure.

[0054] The raw material of the spring receiving member 4, i.e., the thermoplastic resin, preferably includes polyethylene thermoplastic resin, polypropylene thermoplastic resin, polyester thermoplastic elastomer, polypropylene thermoplastic elastomer, a mixture of polyethylene thermoplastic resin and polyethylene thermoplastic elastomer, PVC, polyurethane elastomer, nylon elastomer, polystyrene elastomer, etc.

[0055] For the spring receiving member 4, in the tensile test described later, the maximum load (maximum endurance) in the extrusion direction during manufacturing is 9.8 to 294.2 N, preferably 19.6 to 294.2 N. If the maximum load in the tensile test is less than 19.6 N, there is a possibility that the fusion of the fibers will peel off during compression. The maximum load in the extrusion direction is affected by the fineness, bulk density, raw materials, and structure.

[0056] The above-mentioned tensile test was performed in the following manner.

[0057] The structure obtained by cutting the three-dimensional network structure product into 10 cm (length: extrusion direction) × 10 cm (width) is used as a test piece. The upper end of the test piece is fixed, and a hook with a diameter of 5 mm and R20 is hung 4 cm above the lower end of the central part in the width direction of the test piece. It is pulled downward to measure the maximum load.

[0058] The detailed manufacturing method of the spring receiving member 4 used in the present invention is basically the same as that of the three-dimensional network structure 2 .

[0059] The three-dimensional network structure 2 preferably has a width c of 100 to 2000 mm and a depth b of 200 to 700 mm. The vertical nonwoven fabric 3 preferably has a width a of 300 to 2000 mm and a depth d of 300 to 800 mm.

[0060] The spring receiving member 4 may be made of felt, nonwoven fabric, or the like, in addition to the three-dimensional mesh structure described above.

[0061] In the present embodiment, the vehicle seat 1 is formed by forming a groove 32 on the inner surface of the longitudinal nonwoven fabric 3, and is manufactured by inserting the three-dimensional mesh structure 2 into the groove 32, laminating the spring receiving member 4, and covering it with a covering cover (not shown). The three-dimensional mesh structure 2, the longitudinal nonwoven fabric 3, and the spring receiving member 4 can be covered by the covering cover in a state of being fitted and laminated without bonding, but they can also be joined to each other by heat fusion, hook and loop fasteners, adhesives such as hot melt adhesives, etc.

[0062] The three-dimensional network structure 2 and the longitudinal nonwoven fabric 3 preferably have a limiting oxygen index (LOI value) of 28 or more. In addition, the cover is preferably made of flame-retardant fiber, and when used for a seat for a train, the limiting oxygen index (LOI value) is preferably 28 or more. As the flame-retardant fiber, known fibers such as carbon fibers and fire-resistant fibers are used.

[0063] In the present invention, the longitudinal nonwoven fabric 3 is arranged on the surface side (human body side) to improve deformation resistance, durability and touch, and the three-dimensional network structure 2 is arranged on the lower surface to improve cushioning properties and sitting comfort.

[0064] The 25% compression hardness of the dense part 21 and the sparse part 22 of the three-dimensional network structure 2 is higher than that of the longitudinal nonwoven fabric 3. The 25% compression hardness is measured according to JIS K6400-2. Specifically, it is preferred that the 25% compression hardness of the dense part 21 of the three-dimensional network structure is 80 to 180N, the 25% compression hardness of the sparse part 22 is 40 to 130N, and the 25% compression hardness of the longitudinal nonwoven fabric 3 (excluding the high-density part 31) is 25 to 100N. By making the hardness of the longitudinal nonwoven fabric 3 below 100N, a soft touch when sitting can be obtained, and by making the hardness above 25N, it is prevented from sinking. In this embodiment, the longitudinal nonwoven fabric 3 and the three-dimensional network structure 2 are composed of thermoplastic elastic resin, so that most of the vibration given from the outside is absorbed and attenuated by the vibration absorption function of the thermoplastic elastic resin, thereby functioning as a vibration cutoff layer.

[0065] Next, refer to Figure 3 (a) to (c) illustrate a vehicle seat 101 (cushion material) according to a second embodiment of the present invention. The vehicle seat 101 has basically the same structure as the vehicle seat 1, so the common description refers to the illustrations and descriptions of the first embodiment, and the differences are described. The reference numerals in the figure marked on each element are the corresponding numbers of the first embodiment, which are set to 100 segment numbers.

[0066] In the first embodiment, the first buffer body is composed of a single layer of a three-dimensional mesh structure, but in the second embodiment, the first buffer body is composed of a double layer of an upper layer 121 and a lower layer 122. The upper layer 121 is composed of a three-dimensional mesh structure, and as the lower layer 122, non-woven fabrics with fibers oriented in the transverse direction (planar direction), longitudinal non-woven fabrics, foamed polyurethane, and other buffer materials can be used. By further providing a lower layer and an intermediate layer, it is also possible to form a plurality of layers such as three layers and four layers. In each example of the lower layer 122 described below, it is also preferred to have a sparse or dense structure in the thickness direction, the front-back direction, and the left-right direction.

[0067] exist Figure 3In (a), the upper layer 121 constituting the first buffer body 102 is composed of a three-dimensional network structure, and the lower layer 122 is a nonwoven fabric in which fibers are oriented in the transverse direction (plane direction). This can improve durability.

[0068] exist Figure 3 In (b), the upper layer 121 constituting the first buffer body 102 is composed of a three-dimensional mesh structure, and the lower layer 122 is composed of a longitudinal nonwoven fabric. The longitudinal nonwoven fabric used for the lower layer 122 is a nonwoven fabric with a higher bulk density and a harder texture than the longitudinal nonwoven fabric 103 used as the second buffer body. The longitudinal nonwoven fabric 103 preferably has a 25% compression hardness of 25 to 100 N and a density of 25 to 80 g / cm 3 The lower layer 122 preferably has a 25% compression hardness of 40 to 140 N and a density of 40 to 100 g / cm 3 As a result, the elasticity is improved, and the sitting comfort is also improved. In addition, the 25% compression hardness is measured according to JIS K6400-2. The 25% compression hardness can be adjusted by changing the material constituting the nonwoven fabric, the bulk density, and the fineness.

[0069] exist Figure 3 In (c), the upper layer 121 is a three-dimensional network structure, and the lower layer 122 is a polyurethane foam. By using the polyurethane foam, high durability can be obtained.

[0070] Next, refer to Figure 4 A vehicle seat 201 according to a third embodiment of the present invention will be described. The vehicle seat 201 has basically the same structure as the vehicle seat 1, so the common description will refer to the illustrations and descriptions of the first embodiment, and the differences will be described. The reference numerals for the corresponding numbers in the first embodiment are set to 200 segment numbers.

[0071] In the vehicle seat of the first embodiment, the three-dimensional mesh structure 2 as the first buffer body is fitted into the groove portion 32 of the inner surface of the longitudinal nonwoven fabric 3 as the second buffer body, but in the vehicle seat of the second embodiment, a longitudinal nonwoven fabric 203 whose lower surface is substantially flat is laminated on the three-dimensional mesh structure 202, and the longitudinal nonwoven fabric 203 is covered by a covering cover (not shown) together with the spring receiving member 204. A high-density portion 231 is formed in a thinner portion in the front region of the longitudinal nonwoven fabric 203, and a sparse-density structure having a sparse portion 222 and a dense portion 221 in the front-back direction is formed in the three-dimensional mesh structure 202, and the dense portion 221 is formed in the middle portion.

[0072] Next, refer to Figures 5 to 7 A mattress 301 as a cushioning material according to a fourth embodiment of the present invention will be described.

[0073] In the first to third embodiments, the cushioning material is used as a vehicle seat, but in this embodiment, it is used as a mattress. The mattress 301 has basically the same structure as the vehicle seat 1, so the illustrations and descriptions of the first embodiment are cited for the common description, and the differences are described. The reference numerals marked on each element are the corresponding numbers of the first embodiment, and the numbers are set to the 300th section.

[0074] like Figure 7 As shown, the mattress 301 is, for example, a mattress used for a bed installed in the rear part of the cab of the truck 8. As is well known, the mattress 301 can be used for a driver or the like to take a nap in the vehicle, or for a passenger to sit in the rear between the seats 81.

[0075] Figure 5 The mattress 301 is a cross-sectional view in the longitudinal direction. The mattress 301 includes a first buffer body composed of a three-dimensional network structure 302 and a second buffer body composed of a longitudinal nonwoven fabric 303 covering the upper surface of the three-dimensional network structure 302. The longitudinal nonwoven fabric 303 as the second buffer body has an overall bulk density of 0.005 to 0.50 g / cm 3 , and has a sparse structure in which sparse parts and dense parts extending in the length direction and the width direction are repeatedly arranged in the front-to-back direction. The central part becomes a high-density part 331, and there are medium-density parts 333 on both sides thereof.

[0076] The three-dimensional mesh structure 302 as the first buffer body also has a sparse and dense structure in which sparse parts and dense parts extending in the longitudinal direction and the width direction are repeatedly arranged in the front-to-back direction. The central part becomes the dense part 321, and the two sides become the sparse parts 322. The first buffer body has a bulk density of 0.03 to 0.80 g / cm 3 . The dense portion 321 is present in a manner abutting against the lower surface of the high-density portion 331. As described above, the co-pilot sometimes sits in the center of the mattress 301, but since the high-density portion 331 is provided in the central portion in the longitudinal direction, durability is improved. In addition, it has the advantage of being very comfortable to lie down when the driver or the like is sleeping. The entirety or the upper surface and side surfaces of the stack of the three-dimensional mesh structure 302 and the longitudinal non-woven fabric 303 are covered with a covering cover (not shown) made of cotton cloth, non-woven fabric, or the like. The stack of the three-dimensional mesh structure 302 and the longitudinal non-woven fabric 303 may be covered by the covering cover in a state where they are stacked without being bonded to each other, or they may be bonded to each other by heat-based fusion, hook-and-loop fasteners, adhesives such as hot melt adhesives, or the like.

[0077] Figure 6301 is a cross-sectional view in the longitudinal direction of a modified example of a mattress 301. The mattress 301 has a first buffer body composed of a three-dimensional mesh structure 302 and a second buffer body composed of a longitudinal nonwoven fabric 303. The three-dimensional mesh structure 302 has a surface layer 323, an upper layer 324, and a base layer 325 from the surface. The surface layer 323 is a thin high-density layer of about 2 mm, and the bulk density is 0.045 to 0.80 g / cm 3 The bulk density of the base layer 325 is lower than that of the surface layer 323, and the bulk density is 0.040 to 0.70 g / cm 3 The bulk density of the upper layer 324 is lower than that of the surface layer 323 and the base layer 325, and the bulk density is 0.040 to 0.70 g / cm 3 .

[0078] Next, refer to Figure 8 A mattress 401 as a cushioning material of the fifth embodiment of the present invention is described. The mattress 401 has basically the same structure as the mattress 301, so the illustrations and descriptions of the fourth embodiment are cited for the general description, and the differences are described. The figure marks marked on each element are numbers in the 400 segment corresponding to the numbers in the fourth embodiment. In the fourth embodiment, the stack of the three-dimensional mesh structure 302 and the longitudinal non-woven fabric 303 is covered by a covering cover, while in this embodiment, the longitudinal non-woven fabric 403 is included in the covering cover 405 covering the three-dimensional mesh structure 402. The longitudinal non-woven fabric 403 is thinner than the three-dimensional mesh structure 402. It is preferred to put the longitudinal non-woven fabric 403 into the covering cover 405 and fix it by quilting.

[0079] In this embodiment, the longitudinal nonwoven fabric 403 and the three-dimensional mesh structure 402 have uniform bulk density as a whole, but as in the fourth embodiment, it is preferred that a high-density portion is provided in the central portion in the longitudinal direction, or the three-dimensional mesh structure 402 has a surface layer, an upper layer, and a base layer with different bulk densities in the thickness direction. According to this embodiment, since it is sufficient to install a cover on the three-dimensional mesh structure 402, it has the advantages of easy manufacturing. In addition, in the vehicle seats of the first to third embodiments, it is also preferred that the longitudinal nonwoven fabric is fixed in the cover as in this embodiment.

[0080] Description of Reference Numerals

[0081] 1. 101. 201... vehicle seat; 301. 401... mattress; 2. 202. 302. 402... three-dimensional network structure (first buffer); 102... first buffer; 21. 221. 321... dense part; 22. 222. 322... sparse part; 3. 103. 203. 303. 403... longitudinal nonwoven fabric (second buffer); 31. 231. 331... high-density part; 333... medium-density part; 323... surface layer; 324... upper layer; 325... base layer; 32... groove part; 4. 104. 204... spring receiving member; 121... upper layer of first buffer; 122... lower layer of first buffer; 8... truck.

Claims

1. A cushioning material, It is characterized in that have: a first buffer body; and The second buffer body is arranged above the first buffer body and covers at least the upper surface of the first buffer body. The first buffer body includes a three-dimensional network structure obtained by irregularly and partially welding continuous lines of thermoplastic resin to form loops. The second buffer body is composed of a longitudinal nonwoven fabric in which fibers are oriented in the thickness direction. The cushioning material is used for a vehicle seat. The three-dimensional network structure included in the first cushioning body has a sparse and dense structure in which sparse parts and dense parts extending in the width direction of the vehicle seat are repeatedly arranged in the front-to-back direction. The dense part is provided in the middle part of the vehicle seat in the front-to-back direction.

2. The cushioning material according to claim 1, It is characterized in that The longitudinal nonwoven fabric has a pleated structure and includes a high-density portion in a front region of the vehicle seat where the bulk density is higher than that of the inner portion.

3. The cushioning material according to claim 1, It is characterized in that The first buffer body is fitted into a groove provided on the lower surface of the second buffer body to form an integrated body. In the second shock absorbing body, a region in front of the front surface of the first shock absorbing body is a high-density portion having a higher packing density than other regions.

4. The cushioning material according to claim 1, It is characterized in that A spring receiving member is provided below the first buffer body and the second buffer body. The spring receiving member is composed of a bulk density of 0.5 to 0.01 g / cm 3 , a three-dimensional network structure having a thickness of 0.5 to 25 mm, wherein the three-dimensional network structure is obtained by irregularly partially welding continuous lines of thermoplastic resin to form rings, The three-dimensional network structure constituting the spring receiving member has a higher bulk density than the three-dimensional network structure included in the first shock-absorbing body.

5. The cushioning material according to claim 1, It is characterized in that The first buffer body is composed of multiple layers, including a three-dimensional network structure as an upper layer, and a second longitudinal nonwoven fabric as a layer located below the upper layer, and the second longitudinal nonwoven fabric has a higher bulk density than the longitudinal nonwoven fabric constituting the second buffer body.

6. The cushioning material according to claim 1, It is characterized in that The first shock absorbing body is composed of a plurality of layers, including a three-dimensional network structure as an upper layer, and a nonwoven fabric in which fibers are oriented in a transverse direction as a layer located below the upper layer.

7. The cushioning material according to claim 1, It is characterized in that The first buffer body is composed of a plurality of layers, including a three-dimensional network structure as an upper layer and a polyurethane foam as a layer located below the upper layer.

8. The cushioning material according to any one of claims 1 to 7, It is characterized in that The 25% compression hardness of the longitudinal nonwoven fabric is smaller than that of the three-dimensional network structure.

9. The cushioning material according to any one of claims 1 to 7, It is characterized in that The second buffer body is contained in a covering cover that covers at least the upper surface of the first buffer body.

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