Three-dimensional network structure and vehicle seat having three-dimensional network structure

Abstract

Provided is a three-dimensional network structure capable of enhancing stability during seating, in which a step portion of the three-dimensional network structure does not come into direct contact with the body of a user, reducing a foreign object sensation during seating, and providing comfortable seating feeling. A three-dimensional network structure 1 is composed of a continuous linear body formed from a thermoplastic resin composition and has a three-dimensional random loop joint structure. The three-dimensional network structure 1 has a user side surface and an opposite side surface which is a surface positioned on the side opposite to the user side surface. The three-dimensional network structure 1 has a front side portion 10 which is a portion positioned on the front side relative to the user and a rear side portion 20 which is a portion positioned on the rear side relative to the user. The front side portion 10 on the opposite side surface has a front side recess 30, and the rear side portion 20 on the opposite side surface has a rear side recess 40.

Description

Three-dimensional mesh structure, and vehicle seat having a three-dimensional mesh structure

[0001] This disclosure relates to a three-dimensional mesh structure and a vehicle seat having a three-dimensional mesh structure.

[0002] Currently, three-dimensional mesh structures are being widely used as cushioning materials in furniture, bedding such as beds, and seats in vehicles such as trains, automobiles, and motorcycles. Compared to foamed and cross-linked polyurethane, three-dimensional mesh structures have comparable durability, superior moisture permeability and breathability, and less heat retention, making them less prone to stuffiness. Furthermore, three-dimensional mesh structures are made of thermoplastic resin, are easily recyclable, and have the advantage of being environmentally friendly with no concerns about residual chemicals.

[0003] For example, Patent Document 1 describes a three-dimensional random loop joint structure in which a continuous linear material of 300 denier or more is bent and twisted to form random loops, and the contact portions are fused together, with an apparent density of 0.005 to 0.20 g / cm³. ３ A mesh structure for cushioning, which has excellent heat resistance, durability, and cushioning properties, is disclosed.

[0004] Japanese Patent Application Publication No. 7-68061

[0005] In mesh structures like the one described in Patent Document 1 above, there was a need to improve comfort when sitting on the mesh structure by increasing stability while seated and reducing the feeling of foreign body contact between the user's body and the mesh structure, and there was room for improvement.

[0006] This disclosure aims to provide a three-dimensional mesh structure that can enhance stability while seated, and that reduces the feeling of foreign objects while seated, as the user's body does not directly come into contact with the stepped portion of the three-dimensional mesh structure, resulting in a comfortable seating experience.

[0007] A three-dimensional mesh structure according to the first embodiment of the present disclosure is as follows: [1] A three-dimensional mesh structure having a three-dimensional random loop joint structure, comprising a continuous linear body made of a thermoplastic resin composition, having a user side and a opposite side which is a side located opposite to the user side, having a front portion which is a portion located in front of the user and a rear portion which is a portion located behind the user, having a front recess in the front portion of the opposite side and having a rear recess in the rear portion of the opposite side.

[0008] A three-dimensional mesh structure according to a second embodiment of the present disclosure is as follows: [2] A three-dimensional mesh structure having a three-dimensional random loop joint structure, comprising a continuous linear body made of a thermoplastic resin composition, having a user side and a face opposite to the user side, having a front portion which is located in front of the user and a rear portion which is located behind the user, having a front recess in the front portion of the user side and having a rear recess in the rear portion of the user side, wherein the front recess and the rear recess have a cross-sectional area perpendicular to the depth direction of the recess that decreases from the user side toward the face opposite.

[0009] Furthermore, the three-dimensional mesh structure according to the first and second embodiments of the present disclosure is preferably as follows: [3] The three-dimensional mesh structure according to [1] or [2], wherein the front portion has a right front portion located to the right of the user and a left front portion located to the left of the user, and the right front portion and the left front portion each have the front recess. [4] The three-dimensional mesh structure according to any one of [1] to [3], wherein the opening edge of the rear recess has a right portion located to the right of the user, a left portion located to the left of the user, and a central portion located between the right portion and the left portion, and the average length of the central portion in the front-rear direction of the user is shorter than the maximum length of the right portion in the front-rear direction and the maximum length of the left portion in the front-rear direction. [5] The three-dimensional mesh structure according to any one of [1] to [4], wherein the rear portion has a right rear portion located to the right of the user and a left rear portion located to the left of the user, and the right rear portion and the left rear portion each have the rear recess. [6] A three-dimensional mesh structure according to any one of [1] to [5], wherein the front portion has a protrusion on the user side. [7] A three-dimensional mesh structure according to any one of [1] to [6], wherein the shortest distance from the opening edge of the front recess to the opening edge of the rear recess is greater than half the maximum length of the opening edge of the rear recess in the user's front-rear direction. [8] A three-dimensional mesh structure according to any one of [1] to [7], wherein the maximum depth of the front recess and the maximum depth of the rear recess are 10% or more and 60% or less of the maximum thickness of the three-dimensional mesh structure. [9] A three-dimensional mesh structure according to [1], wherein an upper layer and a lower layer are laminated, and the lower layer has through holes that form the front recess and the rear recess, respectively.

[10] A three-dimensional mesh structure according to [2], wherein an upper layer and a lower layer are laminated, and the upper layer has through holes that form the front recess and the rear recess, respectively.

[0010] Furthermore, the vehicle seat according to the embodiment of the present disclosure is preferably as follows: A vehicle seat having a three-dimensional mesh structure as described in any of

[11] [1] to

[10] .

[0011] In the three-dimensional mesh structure according to the first embodiment of this disclosure, the three-dimensional mesh structure has a three-dimensional random loop joint structure, which reduces the feeling of heat when sitting and provides a comfortable sitting experience. Furthermore, the front and rear recesses can support the user's thighs and buttocks, which tend to experience high pressure when sitting on the three-dimensional mesh structure, thereby improving stability when sitting. In addition, by having the front and rear recesses on the side opposite to the user's side, the user's body does not directly come into contact with the steps created by the front and rear recesses when sitting on the three-dimensional mesh structure, reducing the feeling of foreign objects when sitting, making it a three-dimensional mesh structure particularly suitable as a vehicle seat.

[0012] In the three-dimensional mesh structure according to the second embodiment of this disclosure, the three-dimensional mesh structure has a three-dimensional random loop joint structure, which reduces the feeling of heat when sitting and provides a comfortable sitting experience. Furthermore, the front and rear recesses can support the user's thighs and buttocks, which tend to experience high pressure when sitting on the three-dimensional mesh structure, thereby improving stability when sitting. Moreover, because the cross-sectional area perpendicular to the depth direction of the recesses decreases from the user's side toward the opposite side, the step difference caused by the front and rear recesses on the user's side does not become large. When sitting on the three-dimensional mesh structure, the step difference caused by the front and rear recesses does not come into direct contact with the user's body, reducing the feeling of foreign objects when sitting. This makes it a three-dimensional mesh structure particularly suitable as a vehicle seat.

[0013] This shows a plan view of the three-dimensional mesh structure on the user's side according to the first embodiment of this disclosure. This shows a plan view of the three-dimensional mesh structure shown in Figure 1 on the opposite side. This shows a cross-sectional view of the three-dimensional mesh structure shown in Figure 1 from III to III. This shows a plan view of the three-dimensional mesh structure on the user's side according to the second embodiment of this disclosure. This shows a plan view of the three-dimensional mesh structure shown in Figure 4 on the opposite side. This shows a cross-sectional view of the three-dimensional mesh structure shown in Figure 4 from VI to VI. This shows a plan view of the three-dimensional mesh structure on the user's side according to another embodiment. This shows a plan view of the three-dimensional mesh structure shown in Figure 7 on the opposite side. This shows a cross-sectional view of the three-dimensional mesh structure shown in Figure 7 from IX to IX.

[0014] The following will provide a detailed explanation of this disclosure with reference to the drawings. However, this disclosure is not limited to the illustrated examples, and it is possible to implement it with appropriate modifications to the extent that it conforms to the spirit of the preceding and following sections, and all such modifications are included within the technical scope of this disclosure. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. For the sake of ease of understanding, some parts of the drawings may be simplified or exaggerated, and the dimensional ratios, etc., are not limited to those indicated in the drawings.

[0015] First, a three-dimensional mesh structure according to the first embodiment of this disclosure will be described in detail.

[0016] The first three-dimensional mesh structure of the present disclosure is a three-dimensional mesh structure having a three-dimensional random loop joint structure, composed of a continuous linear body made of a thermoplastic resin composition, and having a user side and a counter-side which is a side located opposite to the user side, and having a front portion which is a part located in front of the user and a rear portion which is a part located behind the user, and having a front recess in the front portion of the counter-side, and a rear recess in the rear portion of the counter-side.

[0017] The three-dimensional mesh structure of this disclosure is composed of continuous linear bodies made of a thermoplastic resin composition and has a three-dimensional random loop joint structure. Specifically, the continuous linear bodies made of a thermoplastic resin composition are bent to form random loops, and the continuous linear bodies are brought into contact with each other and the contact portions are fused to form a three-dimensional mesh structure having a three-dimensional random loop joint structure. Therefore, even if the three-dimensional mesh structure is subjected to a large deformation by a very large stress, the entire three-dimensional mesh structure made of fused and integrated three-dimensional random loops can deform and absorb the stress, and when the stress is released, the three-dimensional mesh structure can recover to its original form by the elastic force of the thermoplastic resin.

[0018] By having a three-dimensional mesh structure composed of continuous linear bodies and possessing a three-dimensional random loop joint structure, it is possible to create a three-dimensional mesh structure that reduces the feeling of heat when sitting and has excellent cushioning properties that distribute body pressure well.

[0019] The components of the three-dimensional network structure are described below, but in this specification, each component can be used individually or in combination of multiple types. The thermoplastic resin composition for the continuous linear structure is not particularly limited as long as it can be bent and brought into contact with other continuous linear structures and the contact portions between the continuous linear structures can be fused together. Examples include polyester-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and thermoplastic ethylene vinyl acetate copolymer elastomers. Among these, the thermoplastic elastomer is preferably a polyester-based thermoplastic elastomer because it has excellent compressive durability and heat resistance.

[0020] Examples of polyester-based thermoplastic elastomers include polyester ether block copolymers in which thermoplastic polyester is the hard segment and polyalkylenediol is the soft segment, or polyester ester block copolymers in which aliphatic polyester is the soft segment.

[0021] Examples of polyester ether block copolymers include ternary block copolymers composed of a dicarboxylic acid, a diol component, and a polyalkylenediol. Examples of dicarboxylic acids include at least one dicarboxylic acid selected from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, and diphenyl-4,4'-dicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dimer acid; or ester-forming derivatives thereof.

[0022] Examples of diol components include at least one diol component selected from aliphatic diols such as 1,4-butanediol, ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, and hexamethylene glycol; alicyclic diols such as 1,1-cyclohexanedimethanol and 1,4-cyclohexanedimethanol; or ester-forming derivatives thereof.

[0023] Examples of polyalkylenediols include at least one of the polyalkylenediols with a number average molecular weight of approximately 300 to 5000, such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and glycols composed of ethylene oxide-propylene oxide copolymers.

[0024] Examples of polyester ester block copolymers include ternary block copolymers composed of a dicarboxylic acid, a diol component, and a polyester diol. Examples of dicarboxylic acid and diol components include those listed above. Examples of polyester diols include polyester diols such as polylactones with a number average molecular weight of approximately 300 to 5000.

[0025] Considering the thermal adhesion, hydrolysis resistance, elasticity, and heat resistance of the continuous linear material, it is particularly preferable that the polyester ether block copolymer is a ternary block copolymer in which the dicarboxylic acid is terephthalic acid and / or naphthalene 2,6-dicarboxylic acid, the diol component is 1,4-butanediol, and the polyalkylenediol is polytetramethylene glycol.

[0026] Furthermore, in polyester ester copolymers, it is particularly preferable that the dicarboxylic acid is terephthalic acid and / or naphthalene 2,6-dicarboxylic acid, the diol component is 1,4-butanediol, and the polyester diol is a ternary block copolymer composed of polylactone. In special cases, those incorporating polysiloxane-based soft segments can also be used.

[0027] The soft segment content of the polyester thermoplastic elastomer in this disclosure is preferably 15% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, and particularly preferably 40% by mass or more, from the viewpoint of excellent compressive durability, and preferably 80% by mass or less, more preferably 70% by mass or less, from the viewpoint of ensuring hardness and excellent heat resistance.

[0028] In this disclosure, the polyolefin-based thermoplastic elastomer is preferably an ethylene-α-olefin copolymer obtained by copolymerizing ethylene and α-olefin, and more preferably a multi-block copolymer consisting of ethylene and α-olefin, which is an olefin block copolymer. The reason why a multi-block copolymer consisting of ethylene and α-olefin is more preferable is that in general random copolymers, the chain length of the main chain is short, making it difficult to form a crystalline structure and reducing durability. From this viewpoint, the α-olefin copolymerized with ethylene is preferably an α-olefin having 3 or more carbon atoms.

[0029] Here, examples of α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, Examples include 1-eicosene, preferably 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, etc. Two or more of these can also be used.

[0030] The random copolymers, which are ethylene-α-olefin copolymers in this disclosure, can be obtained by copolymerizing ethylene and α-olefin using a catalyst system that has a specific metallocene compound and an organometallic compound as its basic components, and the multiblock copolymers can be obtained by copolymerizing ethylene and α-olefin using a chain shuttle reaction catalyst. If necessary, two or more polymers polymerized by the above methods, or polymers such as hydrogenated polybutadiene and hydrogenated polyisoprene can be blended.

[0031] In the ethylene-α-olefin copolymer in this disclosure, the ratio of ethylene to α-olefin having 3 or more carbon atoms is preferably 70 mol% to 95 mol% for ethylene and 5 mol% to 30 mol% for α-olefin having 3 or more carbon atoms. Generally, it is known that polymer compounds acquire elastomer properties because hard segments and soft segments exist within the polymer chain. In the polyolefin-based thermoplastic elastomer in this disclosure, it is considered that ethylene plays the role of the hard segment and α-olefin having 3 or more carbon atoms plays the role of the soft segment. Therefore, if the ratio of ethylene is less than 70 mol%, the hard segment is reduced, and the recovery performance of rubber elasticity decreases. The ratio of ethylene is more preferably 75 mol% or more, and even more preferably 80 mol% or more. On the other hand, if the ratio of ethylene exceeds 95 mol%, the soft segment is reduced, making it difficult to exhibit elastomer properties and potentially resulting in poor cushioning performance. The ratio of ethylene is more preferably 93 mol% or less, and even more preferably 90 mol% or less.

[0032] Representative examples of polyurethane thermoplastic elastomers in this disclosure include polyurethane elastomers obtained by reacting a polyether and / or polyester having a number average molecular weight of 1,000 to 6,000 and hydroxyl groups at the ends with a polyisocyanate mainly composed of an organic diisocyanate, in the presence or absence of a common solvent (dimethylformamide, dimethylacetamide, etc.), to which both ends of the prepolymer have isocyanate groups, and then extending the chain with a polyamine mainly composed of a diamine.

[0033] The polyester and / or polyether is preferably a polyalkylenediol such as a polybutylene adipate copolymer polyester having a number average molecular weight of about 1000 to 6000, preferably 1300 to 5000, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or glycol made from an ethylene oxide-propylene oxide copolymer.

[0034] As the polyisocyanate, conventionally known polyisocyanates can be used, mainly isocyanates based on diphenylmethane 4,4'-diisocyanate, and if necessary, trace amounts of conventionally known triisocyanates, etc., may be added. As the polyamine, known diamines such as ethylenediamine and 1,2-propylenediamine may be used as the main component, and trace amounts of triamines and tetraamines may be used in combination if necessary. These polyurethane thermoplastic elastomers may be used individually or in combination of two or more types.

[0035] The soft segment content of the polyurethane thermoplastic elastomer in this disclosure is preferably 15% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, and most preferably 40% by mass or more, from the viewpoint of excellent compressive durability, and preferably 80% by mass or less, and more preferably 70% by mass or less, from the viewpoint of ensuring hardness and excellent heat resistance.

[0036] Examples of polyamide elastomers in this disclosure include those obtained by copolymerizing a polyamide as a hard segment and a polyol as a soft segment. Examples of polyamides as the hard segment include at least one polyamide oligomer obtained from a reaction product of a lactam compound and a dicarboxylic acid, or a diamine and a dicarboxylic acid. Examples of polyols as the soft segment include at least one polyol from among polyether polyols, polyester polyols, polycarbonate polyols, etc.

[0037] Examples of lactam compounds include at least one aliphatic lactam having 5 to 20 carbon atoms, such as γ-butyrolactam, ε-caprolactam, ω-heptalactam, ω-undecalactam, and ω-lauryllactam.

[0038] As the dicarboxylic acid, at least one or more of dicarboxylic acid compounds such as aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and orthophthalic acid are included.

[0039] As the diamine, at least one or more of aliphatic diamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 3-methylpentamethylenediamine, or aromatic diamines such as metaxylenediamine are included.

[0040] Regarding the polyol, as the polyether polyol, at least one or more of polyalkylene diols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and glycols composed of ethylene oxide - propylene oxide copolymers having a number average molecular weight of about 300 to 5000 are included. Also, as the polycarbonate diol, those which are reaction products of low molecular weight diols and carbonate compounds and have a number average molecular weight of about 300 to 5000 are included.

[0041] As the low molecular weight diol, at least one or more of aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and alicyclic diols such as cyclohexanedimethanol and cyclohexanediol are included.

[0042] As the carbonate compound, at least one or more of dialkyl carbonate, alkylene carbonate, diaryl carbonate, etc. can be mentioned. Also, as the polyester polyol, at least one or more of polyester diols such as polylactone having a number average molecular weight of about 300 to 5000 can be mentioned.

[0043] In the polyamide-based thermoplastic elastomer in the present disclosure, from the viewpoint of excellent compression durability, the soft segment content is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and most preferably 20% by mass or more. From the viewpoint of ensuring hardness and excellent heat sag resistance, it is preferably 80% by mass or less, more preferably 70% by mass or less.

[0044] As the thermoplastic ethylene vinyl acetate copolymer elastomer in the present disclosure, it is preferable that the polymer constituting the continuous linear body has a vinyl acetate content of 1 to 35%. From the viewpoint that the rubber elasticity may become poor when the vinyl acetate content is small, the vinyl acetate content is preferably 1% or more, more preferably 2% or more, and still more preferably 3% or more. From the viewpoint that although the rubber elasticity is excellent when the vinyl acetate content increases, the melting point may decrease and the heat resistance may become poor, the vinyl acetate content is preferably 35% or less, more preferably 30% or less, and still more preferably 26% or less.

[0045] Thermoplastic ethylene vinyl acetate copolymer elastomers can also be copolymerized with α-olefins having 3 or more carbon atoms. Examples of α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1- Examples include eicosene, preferably 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene. Two or more of these can also be used.

[0046] The continuous linear bodies constituting the three-dimensional network structure can be composed of a mixture of two or more different thermoplastic elastomers, depending on the purpose. When composed of a mixture of two or more different thermoplastic elastomers, it preferably contains 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more, of a thermoplastic elastomer selected from the group consisting of polyester-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers.

[0047] Various additives can be blended into the thermoplastic elastomer of the continuous linear body constituting the three-dimensional network structure according to the purpose. Examples of additives include plasticizers such as phthalate esters, trimellitate esters, fatty acids, epoxies, adipic acid esters, and polyesters; antioxidants such as known hindered phenols, sulfur-based, phosphorus-based, and amine-based antioxidants; light stabilizers such as hindered amines, triazoles, benzophenones, benzoates, nickel-based, and salicylate-based light stabilizers; antistatic agents; molecular weight regulators such as peroxides; compounds having reactive groups such as epoxy compounds, isocyanate compounds, and carbodiimide compounds; metal deactivators; organic and inorganic nucleating agents; neutralizing agents; antacids; antibacterial agents; fluorescent whitening agents; fillers; flame retardants; flame retardant aids; organic and inorganic pigments, etc.

[0048] The apparent density of the three-dimensional network structure is preferably 0.005 g / cm ３ or more and 0.200 g / cm ３ or less, more preferably 0.010 g / cm ３ or more and <0.180 g / cm ３ or less, even more preferably 0.020 g / cm ３ or more and <0.150 g / cm ３ or less, still more preferably 0.050 g / cm ３ or more and <0.150 g / cm ３ or less. If the apparent density is less than 0.005 g / cm ３ , the hardness required when using the three-dimensional network structure as a cushioning material cannot be maintained, and the texture also deteriorates, which is not preferable. On the other hand, if the apparent density exceeds 0.200 g / cm ３ , the three-dimensional network structure becomes too hard and is not only unsuitable for a cushioning material, but also the weight of the three-dimensional network structure becomes excessively heavy, which is not preferable.

[0049] The thickness of the three-dimensional mesh structure is preferably 5 mm or more, more preferably 10 mm or more, even more preferably 30 mm or more, even more preferably 50 mm or more, and particularly preferably 60 mm or more. If the thickness is less than 5 mm, using the three-dimensional mesh structure as a cushioning material may result in it being too thin, causing a feeling of contact with the floor. By setting the lower limit of the thickness of the three-dimensional mesh structure within the above range, it is possible to provide the three-dimensional mesh structure with appropriate cushioning properties. Furthermore, the thickness of the three-dimensional mesh structure is preferably 300 mm or less, more preferably 200 mm or less, even more preferably 120 mm or less, even more preferably 85 mm or less, and particularly preferably 70 mm or less. By setting the upper limit of the thickness of the three-dimensional mesh structure within the above range, it becomes easier to manufacture using general manufacturing equipment, and the weight of the three-dimensional mesh structure is less likely to become excessively heavy.

[0050] The fiber diameter of the continuous linear members constituting the three-dimensional mesh structure is preferably between 0.1 mm and 3.0 mm. If the fiber diameter is less than 0.1 mm, the continuous linear members become too thin, which may make it difficult to secure the necessary hardness for the three-dimensional mesh structure. If the fiber diameter exceeds 3.0 mm, the hardness of the three-dimensional mesh structure can be secured, but the mesh structure of the three-dimensional mesh structure becomes coarser, which may result in poor compressive durability of the three-dimensional mesh structure.

[0051] The cross-sectional shapes of the continuous linear bodies constituting the three-dimensional network structure include solid cross-sections, hollow cross-sections, and irregularly shaped cross-sections.

[0052] The 25% compressive hardness of the three-dimensional mesh structure is preferably 20 N / φ200 mm or higher. The 25% compressive hardness is the stress at 25% compression in the stress-strain curve obtained by compressing the three-dimensional mesh structure to 75% using a circular compression plate with a diameter of φ200 mm. If the 25% compressive hardness is less than 20 N / φ200 mm, the three-dimensional mesh structure may not be able to obtain sufficient elastic force, and the comfortable cushioning may be impaired. Furthermore, the 25% compressive hardness of the three-dimensional mesh structure is preferably 400 N / φ200 mm or lower. If the 25% compressive hardness exceeds 400 N / φ200 mm, the three-dimensional mesh structure may become too hard, which may be undesirable from the viewpoint of cushioning.

[0053] The 50% compressive hardness of the three-dimensional mesh structure is preferably 100 N / φ200 mm or higher. The 50% compressive hardness is the stress at 50% compression in the stress-strain curve obtained by compressing the three-dimensional mesh structure to 50% using a circular compression plate with a diameter of φ200 mm. If the 50% compressive hardness is less than 100 N / φ200 mm, the three-dimensional mesh structure may not be able to obtain sufficient elastic force, and the comfortable cushioning may be impaired. Furthermore, the 50% compressive hardness of the three-dimensional mesh structure is preferably 1000 N / φ200 mm or lower. If the 50% compressive hardness exceeds 1000 N / φ200 mm, the three-dimensional mesh structure may become too hard, which may be undesirable from the viewpoint of cushioning.

[0054] The continuous linear bodies constituting the three-dimensional network structure may be composite continuous linear bodies combined with other thermoplastic resins, to the extent that the purpose of this disclosure is not impaired. Examples of composite forms include composite continuous linear bodies such as sheath-core type, side-by-side type, and eccentric sheath-core type, when the continuous linear bodies themselves are composited.

[0055] The continuous linear members constituting the three-dimensional network structure preferably have an endothermic peak at a temperature below the melting point of the thermoplastic elastomer constituting the continuous linear members, as measured by a differential scanning calorimeter (DSC) in the melting curve. The three-dimensional network structure made of continuous linear members having an endothermic peak at a temperature below the melting point exhibits significantly improved heat resistance compared to those without an endothermic peak at a temperature below the melting point. To further improve the heat resistance of the three-dimensional network structure, it is also preferable to perform an annealing treatment at a temperature at least 10°C lower than the melting point of the thermoplastic elastomer constituting the continuous linear members after fusion heat bonding. The heat resistance of the three-dimensional network structure is further improved by applying compressive strain to the three-dimensional network structure before annealing. The continuous linear members of the three-dimensional network structure that have undergone annealing treatment exhibit a more clearly defined endothermic peak at a temperature 20°C or more below the melting point, as measured by a differential scanning calorimeter (DSC) in the melting curve. Furthermore, if the three-dimensional network structure is not subjected to annealing treatment, an endothermic peak does not appear in the melting curve at temperatures more than 20°C below the melting point. By analogy, it can be inferred that annealing rearranges the hard segments of the thermoplastic elastomer constituting the continuous linear body, forming pseudo-crystallization-like crosslinking points and improving heat degradation resistance. Hereafter, this annealing treatment may be referred to as "pseudo-crystallization treatment." The effect of this pseudo-crystallization treatment is also effective for polyolefin-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers.

[0056] The three-dimensional mesh structure has a user-side surface and an opposite-side surface located on the opposite side of the user-side surface. The user-side surface is the seating surface that comes into contact with the user when the user sits on the three-dimensional mesh structure, and is the surface surface of the three-dimensional mesh structure when in use. The opposite-side surface is the surface opposite the seating surface that does not come into contact with the user when the user sits on the three-dimensional mesh structure, and is the back surface of the three-dimensional mesh structure when in use.

[0057] As shown in Figures 1 and 2, the three-dimensional mesh structure 1 has a front portion 10 located in front of the user and a rear portion 20 located behind the user. The front portion 10 refers to a part of the three-dimensional mesh structure 1 in front of the user when seated on the three-dimensional mesh structure 1, and supports the user's thighs. The rear portion 20 refers to a part of the three-dimensional mesh structure 1 behind the user when seated on the three-dimensional mesh structure 1, and supports the user's buttocks. In particular, it is preferable that the front portion 10 is the part located in front of the user when the length of the three-dimensional mesh structure 1 in the front-to-back direction of the user is divided into two equal parts, and the rear portion 20 is the part located behind the user. That is, it is preferable that the rear end of the front portion 10 is in contact with the front end of the rear portion 20.

[0058] As shown in Figures 1 to 3, the three-dimensional mesh structure 1 has a front recess 30 in the front portion 10 of the opposite side and a rear recess 40 in the rear portion 20 of the opposite side. In Figure 1, the positions of the front recess 30 and the rear recess 40 are shown by dashed lines.

[0059] When a user sits on the three-dimensional mesh structure 1, pressure tends to be high on the user's thighs and buttocks. Because the three-dimensional mesh structure 1 has a front recess 30 and a rear recess 40, the front recess 30 reduces pressure on the user's thighs, and the rear recess 40 reduces pressure on the user's buttocks, thereby reducing the feeling of pressure when sitting on the three-dimensional mesh structure 1, which in turn improves posture and enhances stability when seated. In particular, when the three-dimensional mesh structure 1 is used in a vehicle seat, it can mitigate the lateral inertial force during vehicle movement and the longitudinal inertial force during acceleration and deceleration, resulting in a more stable posture.

[0060] Furthermore, because the front recess 30 and the rear recess 40 are located on opposite sides of the three-dimensional mesh structure 1, when a user sits on the three-dimensional mesh structure 1, the user's body does not come into direct contact with the steps of the three-dimensional mesh structure 1 caused by the opening edges of the front recess 30 and the rear recess 40. Therefore, when sitting on the three-dimensional mesh structure 1, the user is less likely to feel any foreign body sensation, resulting in a comfortable seating experience. The opening edge of the front recess 30 refers to the edge of the opening located on the opposite side of the bottom of the front recess 30, that is, the entrance edge on the opposite side. The opening edge of the rear recess 40 refers to the edge of the opening located on the opposite side of the bottom of the rear recess 40, that is, the entrance edge on the opposite side.

[0061] As shown in Figure 3, the front recess 30 and the rear recess 40 are non-through holes and are bottomed recesses. Furthermore, the area of ​​the portion enclosed by the opening edge of both the front recess 30 and the rear recess 40 is 50 mm². ２ The above-mentioned non-through holes are used, and the gaps between the continuous linear bodies constituting the three-dimensional mesh structure 1 are not treated as the front recess 30 and the rear recess 40.

[0062] The depth of the front recess 30 and the rear recess 40 is preferably 10 mm or more, more preferably 15 mm or more, even more preferably 20 mm or more, and preferably 50 mm or less, more preferably 40 mm or less, and even more preferably 50 mm or less. By setting the lower and upper limits of the depth of the front recess 30 and the rear recess 40 within the above ranges, the user's thighs and buttocks are more easily supported by the front recess 30 and the rear recess 40, making it easier to improve stability when seated.

[0063] The shape of the opening edge of the front recess 30 can be circular, oval, elliptical, teardrop-shaped, egg-shaped, polygonal, rounded polygonal, gourd-shaped, or a combination thereof. In particular, as shown in Figure 2, the shape of the opening edge of the front recess 30 is preferably a rounded rectangle. By making the opening edge of the front recess 30 a rounded rectangle, the front recess 30 can be made to better support the thigh.

[0064] The shape of the opening edge of the rear recess 40 can be circular, oval, elliptical, teardrop-shaped, egg-shaped, polygonal, rounded polygonal, gourd-shaped, or a combination thereof. In particular, as shown in Figure 2, the shape of the opening edge of the rear recess 40 is preferably a combination of a circle and a square, a so-called dumbbell shape. The so-called dumbbell shape of the opening edge of the rear recess 40 allows for seating stability through the sinking of the buttocks, and also makes it easier to support the buttocks in a balanced manner on both sides.

[0065] Next, a three-dimensional mesh structure according to the second embodiment of this disclosure will be described in detail. In the following description, any parts that overlap with the above description will be omitted.

[0066] As shown in Figures 4 to 6, the three-dimensional mesh structure 1 has a front recess 30 in the front portion 10 on the user's side and a rear recess 40 in the rear portion 20 on the user's side. The cross-sectional area perpendicular to the depth direction of the recess decreases from the user's side toward the opposite side. In Figure 6, the positions of the front recess 30 and the rear recess 40 are shown by dashed lines.

[0067] The front recess 30 and rear recess 40, located on the user's side, have a tapered shape because the cross-sectional area perpendicular to the depth of the recess decreases from the user's side toward the opposite side. In other words, the steps of the three-dimensional mesh structure 1 caused by the opening edges of the front recess 30 and rear recess 40 become gentle. Therefore, even with the configuration in which the front recess 30 and rear recess 40 are located on the user's side, when the user sits on the three-dimensional mesh structure 1, the feeling of foreign body contact caused by the opening edges of the front recess 30 and rear recess 40 coming into contact with the user's body can be reduced, making the seating experience on the three-dimensional mesh structure 1 more comfortable. In the second embodiment, the opening edge of the front recess 30 refers to the edge of the opening located on the opposite side of the bottom of the front recess 30, i.e., the entrance edge on the user's side. The opening edge of the rear recess 40 is the edge of the opening located on the opposite side of the bottom of the rear recess 40, that is, the entrance edge on the user's side.

[0068] The bottom area of ​​the front recess 30 is preferably 90% or less, more preferably 85% or less, and even more preferably 80% or less, of the area of ​​the portion enclosed by the opening edge of the front recess 30 on the user's side. By setting the upper limit of the ratio of the bottom area of ​​the front recess 30 to the area of ​​the portion enclosed by the opening edge of the front recess 30 on the user's side within the above range, the step of the three-dimensional mesh structure 1 caused by the opening edge of the front recess 30 becomes smoother, and the feeling of foreign body when sitting becomes easier to reduce. Furthermore, the bottom area of ​​the front recess 30 is preferably 50% or more, more preferably 55% or more, and even more preferably 60% or more, of the area of ​​the portion enclosed by the opening edge of the front recess 30 on the user's side. By setting the lower limit of the ratio of the bottom area of ​​the front recess 30 to the area of ​​the portion enclosed by the opening edge of the front recess 30 on the user's side within the above range, the front recess 30 becomes easier to support the user's thigh.

[0069] Similarly, for the rear recess 40, the bottom area of ​​the rear recess 40 is preferably 90% or less, more preferably 85% or less, even more preferably 80% or less, and also preferably 50% or more, more preferably 55% or more, and even more preferably 60% or more.

[0070] Preferred configurations of the three-dimensional mesh structure according to the first and second embodiments of this disclosure are described below.

[0071] As shown in Figures 2 and 4, the front portion 10 has a right front portion 11 located on the right side of the user and a left front portion 12 located on the left side of the user, and it is preferable that the right front portion 11 and the left front portion 12 each have a front recess 30. Because the right front portion 11 and the left front portion 12 each have a front recess 30, when the user sits on the three-dimensional mesh structure 1, the left and right thighs are supported individually by the right front portion 11 and the left front portion 12, respectively, which makes it possible to further enhance the stability of the thighs when sitting.

[0072] In particular, in the front portion 10, it is preferable that the portion located on the right side of the user is the right front portion 11, and the portion located on the left side of the user is the left front portion 12, when the length of the three-dimensional mesh structure 1 in the left-right direction of the user is divided into two equal parts.

[0073] As shown in Figures 2 and 4, it is preferable that the opening edge of the rear recess 40 has a right portion 41 located on the right side of the user, a left portion 42 located on the left side of the user, and a central portion 43 located between the right portion 41 and the left portion 42. In other words, it is preferable that the opening edge of the rear recess 40 has a right portion 41, a central portion 43, and a left portion 42, extending from the right side of the user to the left side.

[0074] In particular, it is preferable that the portion of the length from the right end to the left end of the opening edge of the rear recess 40 in the left-right direction of the user is divided into three equal parts, with the portion located to the right of the user being the right portion 41, the portion located to the left of the user being the left portion 42, and the portion located between the right portion 41 and the left portion 42 being the central portion 43. In other words, it is preferable that the left end of the right portion 41 is in contact with the right end of the central portion 43, and the right end of the left portion 42 is in contact with the left end of the central portion 43.

[0075] It is preferable that the average length L43 of the central portion 43 in the front-to-back direction for the user is shorter than the maximum length L41 of the right portion 41 in the front-to-back direction and the maximum length L42 of the left portion 42 in the front-to-back direction. The average length L43 of the central portion 43 in the front-to-back direction for the user can be determined by measuring the length of the central portion 43 in the front-to-back direction at any multiple locations on the central portion 43 and calculating the average value. When the average length L43 of the central portion 43 in the front-to-back direction is shorter than the maximum length L41 of the right portion 41 in the front-to-back direction, and the average length L43 of the central portion 43 in the front-to-back direction is shorter than the maximum length L42 of the left portion 42 in the front-to-back direction, it is possible to reduce the feeling of pressure on the buttocks when sitting on the three-dimensional mesh structure 1 while increasing stability when sitting, and thereby improving the comfort of the sitting posture.

[0076] The average length L43 of the central portion 43 in the front-rear direction is preferably 90% or less of the maximum length L41 of the right portion 41 in the front-rear direction and the maximum length L42 of the left portion 42 in the front-rear direction, more preferably 85% or less, and even more preferably 80% or less. By setting the upper limit of the ratio of the average length L43 of the central portion 43 in the front-rear direction to the maximum length L41 of the right portion 41 in the front-rear direction and the maximum length L42 of the left portion 42 in the front-rear direction to the above range, it is possible to reduce the feeling of pressure on the buttocks when seated. Furthermore, the average length L43 of the central portion 43 in the front-rear direction is preferably 50% or more of the maximum length L41 of the right portion 41 in the front-rear direction and the maximum length L42 of the left portion 42 in the front-rear direction, more preferably 55% or more, and even more preferably 60% or more. By setting the lower limit of the ratio of the average value of the length L43 of the central portion 43 in the front-rear direction to the maximum length L41 of the right portion 41 in the front-rear direction and the maximum length L42 of the left portion 42 in the front-rear direction, the rear recess 40 can more easily support the buttocks when seated, thereby improving seating stability.

[0077] It is more preferable that the maximum length L43 of the central portion 43 in the front-to-back direction of the user is shorter than the maximum length L41 of the right portion 41 in the front-to-back direction and the maximum length L42 of the left portion 42 in the front-to-back direction. By making the maximum length L43 of the central portion 43 shorter than the maximum length L41 of the right portion 41 in the front-to-back direction and the maximum length L42 of the left portion 42 in the front-to-back direction, the rear recess 40 can better support the buttocks and reduce the feeling of pressure on the buttocks.

[0078] As shown in Figures 7 and 8, the rear portion 20 has a right rear portion 21 located on the right side of the user and a left rear portion 22 located on the left side of the user, and the right rear portion 21 and the left rear portion 22 may each have a rear recess 40. Because the right rear portion 21 and the left rear portion 22 each have a rear recess 40, when the user sits on the three-dimensional mesh structure 1, the rear recess 40 of the right rear portion 21 and the rear recess 40 of the left rear portion 22 support the buttocks in a balanced manner from left to right, thereby increasing the stability of the buttocks when seated and further improving the comfort of the posture.

[0079] In particular, in the rear portion 20, it is preferable that the portion located to the right of the user is the right rear portion 21, and the portion located to the left of the user is the left rear portion 22, when the length of the three-dimensional mesh structure 1 in the left-right direction of the user is divided into two equal parts.

[0080] As shown in Figures 7 and 9, the front portion 10 may have a protrusion 50 on the user's side. In other words, the front portion 10 of the three-dimensional mesh structure 1 may have a protrusion 50 that is raised on the user's side. By having a protrusion 50 on the user's side of the front portion 10, the effect of supporting the thighs by the protrusion 50 can be enhanced, and the stability of the thighs when seated can be improved.

[0081] As shown in Figure 9, the shape of the protrusions 50, when viewed from a direction perpendicular to the user's side and the opposite side of the three-dimensional mesh structure 1, is preferably semicircular. The semicircular shape of the protrusions 50 makes it easier to reduce the feeling of foreign body sensation when the protrusions 50 come into contact with the user's body.

[0082] As shown in Figure 9, it is preferable that the maximum height H50 of the protrusion 50 is lower than the maximum height H20 of the rear portion 20. Note that the maximum height H10 of the front portion 10 is not included in the maximum height H50 of the protrusion 50. By making the maximum height H50 of the protrusion 50 lower than the maximum height H20 of the rear portion 20, it is possible to support the thigh while minimizing the feeling of a foreign object caused by the protrusion 50 contacting the user's body.

[0083] As shown in Figure 9, the maximum length L50 of the protrusions 50 in the front-to-back direction of the user is preferably 25% or more, more preferably 30% or more, and even more preferably 35% or more of the maximum length L1 of the three-dimensional mesh structure 1 in the front-to-back direction. By setting the lower limit of the ratio of the maximum length L50 of the protrusions 50 to the maximum length L1 of the three-dimensional mesh structure 1 in the front-to-back direction to the above range, it is possible to make it easier for the user's thighs to be supported by the protrusions 50 when seated. Furthermore, it is preferable that the maximum length L50 of the protrusions 50 in the front-to-back direction of the user is 50% or less of the maximum length L1 of the three-dimensional mesh structure 1 in the front-to-back direction. By setting the maximum length L50 of the protrusions 50 in the front-to-back direction of the user to 50% or less of the maximum length L1 of the three-dimensional mesh structure 1, it is possible to reduce the feeling of foreign body sensation when the protrusions 50 come into contact with the user's body.

[0084] Preferably, the shortest distance from the opening edge of the front recess 30 to the opening edge of the rear recess 40 is greater than half the maximum length of the opening edge of the rear recess 40 in the user's front-to-back direction. By ensuring that the shortest distance from the opening edge of the front recess 30 to the opening edge of the rear recess 40 is greater than half the maximum length of the opening edge of the rear recess 40 in the user's front-to-back direction, it is possible to secure the distance from the front recess 30 to the rear recess 40 while preventing the size of the three-dimensional mesh structure 1 in the front-to-back direction from becoming excessively large, making it easier to maintain a comfortable seated posture.

[0085] The shortest distance from the opening edge of the front recess 30 to the opening edge of the rear recess 40 is preferably more than 50% of the maximum length of the opening edge of the rear recess 40 in the front-to-back direction of the user, more preferably 75% or more, and even more preferably more than 100%. By setting the lower limit of the ratio of the shortest distance from the opening edge of the front recess 30 to the opening edge of the rear recess 40 to the maximum length of the opening edge of the rear recess 40 in the front-to-back direction to the above range, it becomes easier to secure the distance from the front recess 30 to the rear recess 40, and it becomes easier to improve the comfort of the posture when seated. Furthermore, the shortest distance from the opening edge of the front recess 30 to the opening edge of the rear recess 40 is preferably 300% or less of the maximum length of the opening edge of the rear recess 40 in the front-to-back direction of the user, more preferably 275% or less, and even more preferably 250% or less. By setting the upper limit of the ratio of the shortest distance from the opening edge of the front recess 30 to the opening edge of the rear recess 40 to the maximum length of the opening edge of the rear recess 40 in the front-rear direction to the above range, it is possible to prevent the size of the three-dimensional mesh structure 1 from becoming too large in the front-rear direction, and to make the three-dimensional mesh structure 1 easy to handle without being too heavy.

[0086] The maximum depth of the front recess 30 and the maximum depth of the rear recess 40 are preferably 10% to 60% of the maximum thickness of the three-dimensional mesh structure 1. By setting the ratio of the maximum depth of the front recess 30 to the maximum thickness of the three-dimensional mesh structure 1 and the maximum depth of the rear recess 40 to the maximum thickness of the three-dimensional mesh structure 1 within the above range, it is possible to improve the pressure distribution of the three-dimensional mesh structure 1 when seated, while also making it easier for the three-dimensional mesh structure 1 to support the thighs and buttocks and improving seating stability.

[0087] The maximum depth of the front recess 30 and the maximum depth of the rear recess 40 are preferably 10% or more of the maximum thickness of the three-dimensional mesh structure 1, more preferably 20% or more, and even more preferably 30% or more. By setting the lower limit of the ratio of the maximum depth of the front recess 30 and the maximum depth of the rear recess 40 to the maximum thickness of the three-dimensional mesh structure 1 within the above range, it is possible to enhance the effect of the front recess 30 in supporting the thighs and the rear recess 40 in supporting the buttocks. Furthermore, the maximum depth of the front recess 30 and the maximum depth of the rear recess 40 are preferably 60% or less of the maximum thickness of the three-dimensional mesh structure 1, more preferably 55% or less, and even more preferably 50% or less. By setting the upper limit of the ratio of the maximum depth of the front recess 30 and the maximum depth of the rear recess 40 to the maximum thickness of the three-dimensional mesh structure 1 within the above range, the cushioning properties of the three-dimensional mesh structure 1 can be enhanced, further improving the pressure distribution.

[0088] As a specific example, when the maximum thickness of the three-dimensional mesh structure 1 is 70 mm, the maximum depth of the front recess 30 and the maximum depth of the rear recess 40 are preferably 10 mm or more, more preferably 15 mm or more, even more preferably 20 mm or more, and also preferably 50 mm or less, more preferably 45 mm or less, and even more preferably 40 mm or less. By setting the maximum depth of the front recess 30 and the maximum depth of the rear recess 40 within the above ranges, it is possible to create a three-dimensional mesh structure 1 that achieves both pressure distribution and seating stability.

[0089] Methods for forming the front recess 30 include cutting the three-dimensional mesh structure 1 with a cutting tool, stacking a three-dimensional mesh structure 1 with through holes and a three-dimensional mesh structure 1 without through holes, and thermoforming the three-dimensional mesh structure 1 while applying pressure with a mold. Methods for forming the rear recess 40 are the same as those for forming the front recess 30. The method for forming the front recess 30 may be different from the method for forming the rear recess 40, but it is preferable that they be the same in order to improve the manufacturing efficiency of the three-dimensional mesh structure 1.

[0090] As shown in Figure 3, the three-dimensional mesh structure 1 preferably has an upper layer 61 and a lower layer 62 stacked on top of each other, and the lower layer 62 has through holes that form a front recess 30 and a rear recess 40, respectively. By having the three-dimensional mesh structure 1 configured such that the lower layer 62 having through holes that form a front recess 30 and a rear recess 40, respectively, and the upper layer 61 are stacked on top of each other, the three-dimensional mesh structure 1 having a front recess 30 and a rear recess 40 on opposite sides can be easily manufactured.

[0091] As shown in Figure 6, the three-dimensional mesh structure 1 is preferably constructed by stacking an upper layer 61 and a lower layer 62, and the upper layer 61 has through holes that form a front recess 30 and a rear recess 40, respectively. By constructing the three-dimensional mesh structure 1 with an upper layer 61 having through holes that form a front recess 30 and a rear recess 40, and a lower layer 62 stacked on top of each other, it is possible to easily manufacture the three-dimensional mesh structure 1 having a front recess 30 and a rear recess 40 on the user's side.

[0092] The three-dimensional mesh structure 1 of this disclosure is preferably used in a vehicle seat. In other words, a vehicle seat having the three-dimensional mesh structure 1 of this disclosure is preferable. By using the three-dimensional mesh structure 1 of this disclosure in a vehicle seat, it is possible to create a vehicle seat that is highly stable when seated, has less of a foreign body sensation, and provides a comfortable seating experience.

[0093] This application claims the benefit of priority based on Japanese Patent Application No. 2024-175320, filed on 4 October 2024. The entire specification of Japanese Patent Application No. 2024-175320, filed on 4 October 2024, is incorporated herein by reference.

[0094] 1: Three-dimensional mesh structure 10: Front part 11: Right front part 12: Left front part 20: Rear part 21: Right rear part 22: Left rear part 30: Front recess 40: Rear recess 41: Right part 42: Left part 43: Central part 50: Convex part 61: Upper layer 62: Lower layer L1: Length of the three-dimensional mesh structure in the front-to-back direction L41: Maximum length of the right part in the front-to-back direction L42: Maximum length of the left part in the front-to-back direction L43: Length of the central part in the front-to-back direction L50: Length of the convex part in the front-to-back direction H10: Maximum height of the front part H20: Maximum height of the rear part H50: Maximum height of the convex part

Claims

1. A three-dimensional mesh structure having a three-dimensional random loop joint structure, comprising a continuous linear body made of a thermoplastic resin composition, wherein the mesh structure has a user side and a side opposite to the user side, a front portion located in front of the user and a rear portion located behind the user, the front portion of the opposite side having a front recess, and the rear portion of the opposite side having a rear recess.

2. A three-dimensional mesh structure having a three-dimensional random loop joint structure, comprising a continuous linear body made of a thermoplastic resin composition, wherein the structure has a user side and a opposite side which is located on the opposite side from the user side, a front portion which is located on the front side of the user and a rear portion which is located on the rear side of the user, the front portion of the user side has a front recess, and the rear portion of the user side has a rear recess, wherein the cross-sectional area of ​​the front recess and the rear recess perpendicular to the depth direction of the recess decreases from the user side toward the opposite side.

3. The three-dimensional mesh structure according to claim 1 or 2, wherein the front portion has a right front portion located to the right of the user and a left front portion located to the left of the user, and the right front portion and the left front portion each have the front recess.

4. The three-dimensional mesh structure according to claim 1 or 2, wherein the opening edge of the rear recess has a right portion located to the right of the user, a left portion located to the left of the user, and a central portion located between the right portion and the left portion, and the average length of the central portion in the front-to-back direction of the user is shorter than the maximum length of the right portion in the front-to-back direction and the maximum length of the left portion in the front-to-back direction.

5. The three-dimensional mesh structure according to claim 1 or 2, wherein the rear portion has a right rear portion located to the right of the user and a left rear portion located to the left of the user, and the right rear portion and the left rear portion each have the rear recess.

6. The three-dimensional mesh structure according to claim 1 or 2, having a protrusion on the user side of the front portion.

7. The three-dimensional mesh structure according to claim 1 or 2, wherein the shortest distance from the opening edge of the front recess to the opening edge of the rear recess is greater than half the maximum length of the opening edge of the rear recess in the user's front-to-back direction.

8. The three-dimensional mesh structure according to claim 1 or 2, wherein the maximum depth of the front recess and the maximum depth of the rear recess are 10% or more and 60% or less of the maximum thickness of the three-dimensional mesh structure.

9. The three-dimensional mesh structure according to claim 1, wherein an upper layer and a lower layer are stacked, and the lower layer has through holes that form the front recess and the rear recess, respectively.

10. The three-dimensional mesh structure according to claim 2, wherein an upper layer and a lower layer are laminated, and the upper layer has through holes that form the front recess and the rear recess, respectively.

11. A vehicle seat having a three-dimensional mesh structure according to claim 1 or 2.

Images