Cushion body

Abstract

To provide a technique capable of contributing to reduction in weight or reduction in cold sensation of a cushion body while having preferable deflection characteristics.SOLUTION: In a cushion body 10, a resin foam layer 13 and a gel layer 11 are stacked. In a force-distortion curve (first SS curve) obtained when the cushion body 10 is compressed from the resin foam layer 13 side from 0% to 50% at a speed of 10 mm / minute, a correlation coefficient R1 of the first SS curve and an approximation straight line of the first SS curve satisfies 0.90≤R12≤1.0.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cushioning body. [Background technology]

[0002] Patent Document 1 discloses a mat made up of a gel-like viscoelastic material and a film covering the gel-like viscoelastic material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-52182 Summary of the Invention [Problem to be solved by the invention]

[0004] Gel has good flexibility. However, mats using only gel as an elastic body have a large mass, so weight reduction is desirable. Furthermore, mats using only gel as an elastic body tend to feel cold to the touch, so improvement is also desirable.

[0005] The present disclosure aims to provide a technique that can contribute to reducing the weight of a cushion body or reducing the cold feeling while maintaining good deflection characteristics. The present disclosure can be realized in the following aspects. [Means for solving the problem]

[0006] A cushion body in which a resin foam layer and a gel layer are laminated, In the force-deflection curve (first SS curve) obtained when compressing from the resin foam layer side at a rate of 10 mm / min from 0% to 50%, The correlation coefficient R1 between the first SS curve and the approximation line of the first SS curve is 0.90≦R1 2 Cushion body that satisfies ≦1.0. [Effects of the Invention]

[0007] The present disclosure can provide a technology that can contribute to reducing the weight of a cushion body or reducing the cold feeling while maintaining good deflection characteristics. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. [Figure 2] 1 is a graph showing force-deflection curves of Comparative Examples 1 to 3 and Example 1. [Figure 3] 1 is a graph showing the force-deflection curve of Example 2. [Figure 4] 1 is a graph showing the force-deflection curve of Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0009] Here, a preferred example of the present disclosure will be described. [1] A cushion body in which a resin foam layer and a gel layer are laminated, In the force-deflection curve (first SS curve) obtained when compressing from the resin foam layer side at a rate of 10 mm / min from 0% to 50%, The correlation coefficient R1 between the first SS curve and the approximation line of the first SS curve is 0.90≦R1 2 Cushion body that satisfies ≦1.0. [2] In the force-deflection curve (second SS curve) obtained when returning from a 50% compressed state to an unloaded state, The correlation coefficient R2 between the second SS curve and the approximation line of the second SS curve is 0.87≦R2 2 The cushion body according to [1], which satisfies ≦1.0. [3] The cushion body according to [1] or [2], wherein the slope a1 of the approximation line of the first SS curve satisfies 10≦a1≦32. [4] The cushion body according to any one of [1] to [3], wherein the slope a1 of the approximation line of the second SS curve satisfies 10≦a2≦30. [5] The cushion body according to any one of [1] to [4], which is a cushion body having a resin foam layer and a gel layer laminated together, and in which the F hardness of the resin foam layer side is 56 or less.

[0010] The present disclosure will be described in detail below. In this specification, when a numerical range is indicated using "-", it is intended to include both the lower limit and the upper limit unless otherwise specified. For example, the expression "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less". In addition, in this specification, the upper limit and lower limit of each numerical range can be combined in any way.

[0011] 1. Cushion body 10 (part 1) The cushion body 10 (first type) is formed by laminating a resin foam layer 13 and a gel layer 11. In the force-deflection curve (first SS curve) obtained when the cushion body 10 is compressed from the resin foam layer 13 side at a rate of 10 mm / min from 0% to 50%, the correlation coefficient R1 between the first SS curve and the approximation line of the first SS curve is 0.90≦R1 2 Satisfies ≦1.0.

[0012] (1) Gel layer 11 A gel is a substance in which a polymer having a three-dimensional network structure is swollen with a solvent. The gel layer 11 is formed, for example, by encapsulating the gel in a flexible encapsulation body and forming a layer.

[0013] The type of gel in the gel layer 11 is not particularly limited. The gel can be selected from the group consisting of polyurethane gel, polystyrene gel, silicone gel, polyvinyl chloride gel, polyester gel, vinyl acetate copolymer gel, and neoprene gel. Among these, polyurethane gel and polystyrene gel are preferred. The density of the gel is usually 800 kg / m 3 More than 2000kg / m 3 The following is the result.

[0014] (2) Resin foam layer 13 The resin foam layer 13 is made of a sheet-like resin foam. Resin foam usually has a lower density than gel, which contributes to weight reduction. Resin foam also usually has a lower thermal conductivity than gel, which makes it less likely to feel cold to the touch.

[0015] The type of resin foam is not particularly limited, and various synthetic resin foams can be used. The resin foam is, for example, one or more selected from the group consisting of polyurethane foam, polyolefin foam, acrylic foam, silicone foam, rubber foam, and polystyrene foam. Among these, the resin foam is preferably polyurethane foam or polyolefin foam.

[0016] The polyurethane foam is not particularly limited. The cell structure of the polyurethane foam is preferably an open-cell structure or a semi-open-cell structure. The polyurethane foam preferably has a fine and uniform cell structure. The average cell diameter of the polyurethane foam may be, for example, 50 μm or more and 300 μm or less. The average cell diameter can be calculated by dividing the cumulative cell diameter of cells contacting a 25 mm line when observing the cross section of the foam layer with a scanning electron microscope at 200x magnification by the number of cells. Such polyurethane foam can be obtained, for example, by a mechanical froth method from a composition containing a polyol and a polyisocyanate.

[0017] The density of the polyurethane foam is not particularly limited. From the viewpoint of flexural properties, the density of the polyurethane foam is preferably 55 kg / m 3 More preferably, it is 80 kg / m or more. 3 More preferably, it is 100 kg / m or more. 3 More preferably, it is 120 kg / m or more. 3 The density of the polyurethane foam is preferably 700 kg / m from the viewpoint of weight reduction. 3 More preferably, it is 500 kg / m or less. 3 More preferably, it is 400 kg / m or less. 3 and particularly preferably 300 kg / m 3From these viewpoints, the density of the polyurethane foam is preferably 55 kg / m or less. 3 More than 700kg / m 3 More preferably, it is 80 kg / m or less. 3 More than 500kg / m 3 More preferably, it is 100 kg / m or less. 3 More than 400kg / m 3 and particularly preferably 120 kg / m 3 More than 300kg / m 3 The following is the result. In the present disclosure, the density of the resin foam is an apparent density measured in accordance with JIS K7222:2005.

[0018] The polyolefin foam is not particularly limited. The polyolefin foam is preferably, for example, a polyethylene foam or a polypropylene foam, and more preferably a polyethylene foam. The polyethylene foam is preferably a crosslinked polyolefin foam. The polyethylene foam preferably has a closed-cell structure. The polyethylene foam can be obtained, for example, by foaming a composition containing a polyethylene resin using a supercritical gas foaming method.

[0019] The polyethylene resin is at least one selected from the group consisting of low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, and ethylene-vinyl acetate copolymer. Among these, the polyethylene resin preferably contains low-density polyethylene and / or high-density polyethylene.

[0020] The density of the polyolefin foam is not particularly limited. From the viewpoint of flexural properties, the density of the polyolefin foam is preferably 10 kg / m 3 More preferably, it is 12 kg / m or more. 3 The density of the polyolefin foam is preferably 200 kg / m from the viewpoint of weight reduction. 3 More preferably, it is 100 kg / m or less. 3More preferably, it is 80 kg / m or less. 3 or less, and particularly preferably 40 kg / m 3 From these viewpoints, the density of the polyolefin foam is preferably 10 kg / m or less. 3 More than 200kg / m 3 More preferably, it is 10 kg / m or less. 3 More than 100kg / m 3 More preferably, it is 10 kg / m or less. 3 More than 80kg / m 3 and particularly preferably 12 kg / m 3 More than 40kg / m 3 The following is the result.

[0021] It is preferable that the film layer 15 is adhered to the surface of the resin foam layer 13 opposite to the gel layer 11. That is, the cushion body 10 is preferably formed by laminating the film layer 15, the resin foam layer 13, and the gel layer 11 in this order. The film layer 15 may have any configuration, and the cushion body 10 may not necessarily include the film layer 15.

[0022] The film layer 15 may be a layer of a thermoplastic resin film or a layer of a thermosetting resin film, as long as it satisfies the requirements of the first SS curve. More specifically, the film may be a film of a resin selected from the group consisting of thermoplastic polyurethane resin (TPU), styrene elastomer, and silicone-based resin. The tensile elongation of the film measured in accordance with JIS K 7127:1999 is preferably 150% or more. In the case of a thermoplastic resin film, the film layer 15 can be formed by thermocompression bonding the thermoplastic resin film to the resin foam layer 13. In the case of a thermosetting resin film, the film layer 15 can be formed by bonding the thermosetting resin film to the resin foam layer 13 via an adhesive layer.

[0023] It is preferable that the film layer 15 is substantially non-porous from the viewpoint of suppressing abrasion of the resin foam layer 13. The "substantially non-porous" state can be evaluated, for example, by measuring the air permeability. Specifically, the film layer 15 is preferably a film having an air permeability (Gurley air permeability) of more than 10,000 seconds / 100 mL, as determined in accordance with the air permeability measurement method B (Gurley method) specified in JIS L1096:2010.

[0024] (3) Structure of the cushion body 10 The structure of the cushion body 10 is not particularly limited. The cushion body 10 may include only the resin foam layer 13 and the gel layer 11, or may include a layer other than the resin foam layer 13 and the gel layer 11. The resin foam layer 13 and the gel layer 11 may be laminated directly, or may be laminated with another layer interposed therebetween. The resin foam layer 13 and the gel layer 11 may be laminated without being bonded, or may be bonded directly or indirectly.

[0025] In the cushion body 10, for example, the resin foam layer 13 and the gel layer 11 are preferably arranged in this order from the side closest to the surface to which a load is input during use. For example, when a load is input to the upper surface of the cushion body 10, the resin foam layer 13 and the gel layer 11 are preferably arranged in this order from above.

[0026] There are no particular limitations on the thickness of the cushion body 10. When the resin foam layer 13 and the gel layer 11 are directly laminated together, the thickness of the cushion body 10 is preferably approximately the same as the total thickness of the resin foam layer 13 and the gel layer 11.

[0027] The thickness of gel layer 11 is not particularly limited as long as it satisfies the requirements of the first SS curve. From the viewpoint of improving sitting comfort, the thickness of gel layer 11 is preferably 2 mm or more, more preferably 4 mm or more, even more preferably 6 mm or more, and particularly preferably 8 mm or more. From the viewpoint of weight reduction, the thickness of gel layer 11 is preferably 80 mm or less, more preferably 50 mm or less, even more preferably 30 mm or less, and particularly preferably 15 mm or less. From these viewpoints, the thickness of gel layer 11 is preferably 2 mm or more and 80 mm or less, more preferably 4 mm or more and 50 mm or less, even more preferably 6 mm or more and 30 mm or less, and particularly preferably 8 mm or more and 15 mm or less.

[0028] The thickness of the resin foam layer 13 is not particularly limited as long as it satisfies the requirements of the first SS curve. From the viewpoint of improving sitting comfort, the thickness of the resin foam layer 13 is preferably 0.5 mm or more, more preferably 1 mm or more, even more preferably 2 mm or more, and particularly preferably 3 mm or more. From the viewpoint of reducing the thickness of the cushion body 10, the thickness of the resin foam layer 13 is preferably 50 mm or less, more preferably 30 mm or less, even more preferably 15 mm or less, and particularly preferably 10 mm or less. From these viewpoints, the thickness of the resin foam layer 13 is preferably 0.5 mm or more and 50 mm or less, more preferably 1 mm or more and 30 mm or less, even more preferably 2 mm or more and 15 mm or less, and particularly preferably 3 mm or more and 10 mm or less.

[0029] There are no particular limitations on the ratio of the thickness of gel layer 11 to the thickness of resin foam layer 13. The ratio of the thickness of gel layer 11 to the thickness of resin foam layer 13 is preferably 1:0.1 to 1:0.9, more preferably 1:0.2 to 1:0.7, and even more preferably 1:0.3 to 1:0.5.

[0030] (4) Requirements for the first SS curve of the cushion body 10 In the force-deflection curve (first SS curve) obtained when the cushion body 10 is compressed from the resin foam layer 13 side at a rate of 10 mm / min from 0% to 50%, the correlation coefficient R1 between the first SS curve and the approximation line of the first SS curve is 0.90≦R1 2 ≦1.0. The correlation coefficient R1 is 0.93≦R1 2 It is preferable that R1.0 is satisfied, and 0.95≦R1 2 It is more preferable that the ratio satisfies ≦1.0.

[0031] The approximate line can be determined by the linear approximation formula (y = ax + b) using the least squares method. Here, a is the slope, which represents the ratio of the change in load (N) to the change in compression (%). The square of the correlation coefficient indicates how well the approximate line fits the first SS curve. R1 2 is close to 1.0, this is an indicator that the linearity of the first SS curve is high. The more linear the first SS curve is, the more uniformly the user feels the pressure being applied to the contact surface with the cushion body 10, and therefore the more comfortable it is to sit on the cushion body 10.

[0032] R1 2 can be controlled by appropriately selecting the resin foam layer 13. For example, by selecting a resin foam layer 13 with a small cell diameter, the decrease in the slope near the 25% compression rate caused by the collapse of coarse cells can be suppressed, and R1 2 For example, by increasing the density while maintaining the proportion of closed cells and flexibility in the resin foam layer 13, it is possible to suppress the decrease in the slope near the 25% compression rate caused by the collapse of the cells, and to increase R1 2 can be increased.

[0033] The first SS curve can be measured by performing a compression-recovery cycle test using a test device equipped with a circular pressure plate with a diameter of 150 mm in accordance with JIS K6400-2: 2012. A test specimen with a square shape of 250 mm on each side and the same thickness as the cushion body is taken from the cushion body.

[0034] The slope a1 of the approximation line of the first SS curve of the cushion body 10 preferably satisfies 10≦a1≦32, and more preferably satisfies 15≦a1≦30. A large a1 indicates that a large load is required to compress the cushion body 10 to 50%. If a1 is equal to or greater than the above-mentioned lower limit, for example, when sitting on the cushion body 10, the user is less likely to feel like they are hitting the bottom. On the other hand, if a1 is too large, the cushion body 10 feels hard. If a1 is equal to or less than the above-mentioned upper limit, for example, when sitting on the cushion body 10, the user can feel an appropriate softness.

[0035] a1 can be controlled by appropriately selecting the physical properties of the resin foam layer 13. For example, a1 tends to increase by selecting a resin foam layer 13 with a high 50% compression load. a1 tends to decrease by selecting a resin foam layer 13 with a low 50% compression load.

[0036] From the viewpoint of reducing bottoming out, the 25% compression load (when compressed) is preferably 200 N or more, more preferably 250 N or more, and even more preferably 300 N or more. From the viewpoint of flexibility, the 25% compression load (when compressed) is preferably 800 N or less, more preferably 700 N or less, and even more preferably 600 N or less. From these viewpoints, the 25% compression load (when compressed) is preferably 200 N or more and 800 N or less, more preferably 250 N or more and 700 N or less, and even more preferably 300 N or more and 600 N or less.

[0037] From the viewpoint of reducing bottoming out, the 50% compression load is preferably 450 N or more, more preferably 600 N or more, and even more preferably 720 N or more. From the viewpoint of flexibility, the 50% compression load is preferably 2000 N or less, more preferably 1800 N or less, and even more preferably 1600 N or less. From these viewpoints, the 50% compression load is preferably 450 N or more and 2000 N or less, more preferably 600 N or more and 1800 N or less, and even more preferably 720 N or more and 1600 N or less.

[0038] A preferred example of the first SS curve will be described with reference to Example 1 in Fig. 2 and Example 2 in Fig. 3. The first SS curve preferably satisfies at least one of the following requirements [1] to [5], more preferably satisfies requirement [5], and even more preferably satisfies requirements [3] and [5]. [1] The load at 10% compression is greater than 0N and less than 200N. [2] The load at 20% compression is greater than 200N and less than 400N. [3] The load at 30% compression is greater than 400N and less than 600N. [4] The load at 40% compression is greater than 600N and less than 1000N. [5] The load at 50% compression is greater than 1000N and less than 1400N.

[0039] Another preferred example of the first SS curve will be described with reference to Example 3 in Fig. 4. The first SS curve preferably satisfies at least one of the following requirements

[11] to

[15] , more preferably satisfies requirement

[15] , and even more preferably satisfies requirements

[13] and

[15] .

[11] The load at 10% compression is greater than 0N and less than 150N.

[12] The load at 20% compression is greater than 150N and less than 300N.

[13] The load at 30% compression is greater than 300N and less than 450N.

[14] The load at 40% compression is greater than 450N and less than 600N.

[15] The load at 50% compression is greater than 600N and less than 1200N.

[0040] (5) Requirements for the second SS curve of the cushion body 10 In the force-deflection curve (second SS curve) obtained when the cushion body 10 is returned from a 50% compressed state to an unloaded state, the correlation coefficient R2 between the second SS curve and the approximation line of the second SS curve is 0.87≦R2 2 It is desirable to satisfy the following: ≦1.0. The correlation coefficient R2 is 0.90≦R2 2It is preferable that R2 is ≦1.0, and 0.93≦R2 2 It is more preferable that the ratio satisfies ≦1.0. R2 2 is close to 1.0 is an indicator of high linearity of the second SS curve. The higher the linearity of the second SS curve, the more uniform the pressure felt by the user on the contact surface with the cushion body 10, resulting in a comfortable sitting experience when sitting on the cushion body 10. The second SS curve can be measured by performing a compression-recovery cycle test in the same manner as the first SS curve described above.

[0041] R2 2 can be controlled by appropriately selecting the resin foam layer 13. For example, by selecting a resin foam layer 13 with high shape recovery, R2 2 can be increased.

[0042] In the cushion body 10, the slope a2 of the approximation line of the second SS curve preferably satisfies 10≦a2≦30, and more preferably satisfies 15≦a2≦30. a2 can be controlled by appropriately selecting the physical properties of the resin foam layer 13. For example, a2 tends to increase by selecting a resin foam layer 13 with a high 50% compression load. a2 tends to decrease by selecting a resin foam layer 13 with a low 50% compression load.

[0043] (6) Requirements for hysteresis loss rate The cushion body 10 is compressed from the resin foam layer 13 side from 0% to 50% at a speed of 10 mm / min, and the hysteresis loss rate in a compression-recovery cycle in which the cushion body 10 is returned from the 50% compressed state to the no-load state is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. The lower limit of the hysteresis loss rate is not particularly limited, and is usually 10% or more. The hysteresis loss rate can be calculated based on the above-mentioned first SS curve and second SS curve.

[0044] The hysteresis loss rate can be controlled by appropriately selecting the resin foam layer 13. For example, the hysteresis loss rate tends to be smaller by selecting a resin foam layer 13 with high shape recovery.

[0045] 2. Cushion body 10 (part 2) The cushion body 10 (second type) is formed by laminating a resin foam layer 13 and a gel layer 11. The cushion body 10 has an F hardness of 56 or less on the resin foam layer 13 side. In cushion body 10 (part 2), the explanations of gel layer 11, resin foam layer 13, and the structure of cushion body 10 are the same as those of "(1) Gel layer 11," "(2) Resin foam layer 13," and "(3) Structure of cushion body 10" in "1. Cushion body 10 (part 1)."

[0046] From the viewpoint of deflection characteristics, the F hardness on the resin foam layer 13 side is 56 or less, and may be 50 or less, or 45 or less. The lower limit of the F hardness on the resin foam layer 13 side is not particularly limited, and is usually 20 or more, and may be 25 or more, or 30 or more. The F hardness is measured using an ASKER hardness tester, type F. The measurement is performed at a temperature of 23±2°C by placing the ASKER hardness tester on the surface of the cushion body 10 on the resin foam layer 13 side, and reading the value after 20 seconds.

[0047] 3. Use of cushion body 10 The cushion body 10 can be used in a variety of applications. The present disclosure is suitable for use as a sitting mat, bedding, a seat cushion, etc., which includes the cushion body 10. The present disclosure is also suitable for use as nursing care products, medical products, etc., which include the cushion body 10. The shape and size of the cushion body 10 can be set according to the intended use. Depending on the intended use, the cushion body 10 may be covered with a cover or the like that has little effect on the deflection characteristics. [Example]

[0048] The present invention will be explained in more detail below with reference to examples.

[0049] 1. Preparation of the cushion body Cushion bodies of each example and comparative example were produced with the layer structure shown in Table 1. In the "Gel layer" and "Resin foam layer surface" columns of Table 1, for example, the description "t5mm" indicates that a layer of the material in question is provided with a thickness of 5 mm.

[0050] The details of the materials are as follows: <Gel layer> Urethane gel: density 1200 kg / m 3 <Resin foam layer> Polyurethane foam 1: Density 50kg / m 3 , manufactured by Inoac Corporation, EMO, average cell diameter over 300 μm Polyurethane foam 2: density 25 kg / m 3 , manufactured by Inoac Corporation, EMB, average cell diameter over 300 μm Polyurethane foam 3: density 52 kg / m 3 , manufactured by Inoac Corporation, EMM, average cell diameter over 300 μm Polyurethane foam 4: Density 150 kg / m 3 Rogers Inoac Corporation, PORON, TM-15, average cell diameter 300 μm or less Polyolefin foam: Polyethylene foam, density 15kg / m 3 , Inoac Corporation, AZOTE, LD-15, closed-cell structure Polyurethane foam 5: density 200 kg / m 3 Rogers Inoac, PORON, LE-20, average cell diameter 300 μm or less Polyurethane foam 6: density 240 kg / m 3 , Rogers Inoac Corporation, PORON, L-24, average cell diameter 300 μm or less Polyurethane foam 7: density 240 kg / m 3 , Rogers Inoac Corporation, PORON, H-24, average cell diameter 300 μm or less

[0051] [Table 1]

[0052] <Comparative Example 1> The cushion body of Comparative Example 1 was composed of only a gel layer. The size of the gel layer, that is, the product size, was 24 mm thick x 250 mm x 250 mm. <Comparative Examples 2 to 4> In the cushion bodies of Comparative Examples 2 to 4, the resin foam layer was directly superimposed on the gel layer. No film layer was laminated. The size of the gel layer was 12 mm thick x 250 mm x 250 mm. The size of the resin foam layer was 12 mm thick x 250 mm x 250 mm. The product size was 24 mm thick x 250 mm x 250 mm. <Examples 1 to 5> The cushion bodies of Examples 1 to 5 were laminated by directly overlaying a resin foam layer on a gel layer. No film layer was laminated. The size of the gel layer was 12 mm thick x 250 mm x 250 mm. The size of the resin foam layer was 5 mm thick x 250 mm x 250 mm. The product size was 17 mm thick x 250 mm x 250 mm.

[0053] 2. Evaluation (1)Product weight The weight (g) of each cushion body was measured. Using Comparative Example 1 as the reference, the weight loss rates of Comparative Examples 2 to 4 and Examples 1 to 5 were calculated based on the following formula. Weight reduction rate (%)=(1-Ws / W1)×100 Ws = weight (g) of Comparative Examples 2 to 4 and Examples 1 to 5 W1 = weight of Comparative Example 1 (g)

[0054] (2)F hardness The F hardness of one surface of the gel layer of the cushion body of Comparative Example 1 was measured by the method described in the embodiment. The F hardness of the surface of the cushion body of Comparative Examples 2 to 4 and Examples 1 to 5 on the resin foam layer side was measured by the method described in the embodiment.

[0055] (3) Deflection characteristics The cushion bodies of the comparative examples and examples were subjected to a compression-recovery cycle test under the following conditions in accordance with JIS K 6400-2:2012. Testing machine: Shimadzu Corporation, Autograph precision universal testing machine AGS-X / 10kN type, load cell capacity 10kN Pressure plate: 150mm diameter circle Compression speed: 10mm / min ·Recovery speed: 10mm / min Test temperature: 23℃

[0056] From the results of the compression-recovery cycle test, the 25% compression load, 50% compression load, and hysteresis loss rate (%) of the cushion body during compression of each comparative example and example were determined. Furthermore, from the results of the compression-recovery cycle test, a first SS curve and a second SS curve were obtained. From the obtained first SS curve and second SS curve, a1 and R1 2 , a2, R2 2 was calculated.

[0057] (4) Evaluation of weight reduction, comfort, and coolness The cushion bodies of the examples and comparative examples were evaluated for weight reduction based on the following criteria. <Lightweighting criteria> A: The weight loss rate is 45% or more. B: The weight loss rate is 30% or more and less than 45%. C: The weight loss rate is 15% or more and less than 30%. D: The weight loss rate is less than 15%.

[0058] The cushion bodies of each Example and Comparative Example were evaluated for comfort (feel) and coolness (feel) based on the following criteria. The comfort (feel) and coolness (feel) of Comparative Example 1 were evaluated by placing the cushion body on a flat surface and sitting on the top surface of the gel layer. The comfort and coolness of Comparative Examples 2 to 4 and Examples 1 to 5 were evaluated by placing the cushion body on a flat surface with the resin foam layer facing up and sitting on the top surface of the resin foam layer. <Criteria for determining comfort (feel)> A: The feeling when sitting is better than that of Comparative Example 1. B: The feeling when sitting is the same as that of Comparative Example 1. C: The feeling when sitting is slightly worse than that of Comparative Example 1. D: Feels worse when sitting than Comparative Example 1. <Coldness (feeling) criteria> A: I don't feel any coldness at all. B: I hardly feel any cold. C: It feels a little cold. D: It feels cold.

[0059] 3.Results The evaluation results are shown in Table 1. In the "Evaluation" and "Judgment" columns of Table 1, "-" indicates that the evaluation or judgment was not performed.

[0060] (1) Satisfaction of each requirement in Examples 1 to 5 and Comparative Examples 1 to 4 The cushion bodies of Examples 1 to 5 satisfy all of the following requirements (a) and (b). Requirement (a): The cushion body is formed by laminating a resin foam layer and a gel layer. Requirement (b): In a force-deflection curve (first SS curve) obtained when compressing from the resin foam layer side at a rate of 10 mm / min from 0% to 50%, the correlation coefficient R1 between the first SS curve and an approximation line of the first SS curve is 0.90≦R1 2 Satisfies ≦1.0. In contrast, the cushion body of Comparative Example 1 does not satisfy requirement (a), and the cushion bodies of Comparative Examples 2 to 4 do not satisfy requirement (b).

[0061] The cushion bodies of Examples 1 to 5 also satisfy the following requirement (c). Requirement (c): In the force-deflection curve (second SS curve) obtained when returning from a 50% compressed state to a no-load state, the correlation coefficient R2 between the second SS curve and the approximation line of the second SS curve is 0.87≦R2 2 Satisfies ≦1.0.

[0062] The cushion bodies of Examples 1 to 5 also satisfy the following requirement (d). Requirement (d): The slope a1 of the approximation line of the first SS curve satisfies 10≦a1≦32. The cushion bodies of Examples 1 to 5 also satisfy the following requirement (e). Requirement (e): The slope a2 of the approximation line of the second SS curve satisfies 10≦a2≦30. (2) Consideration Comparative Example 1 was rated "D" for weight reduction and "D" for coolness. Comparative Example 2 was rated "D" for comfort. Although the comfort of sitting was not evaluated for Comparative Examples 3 and 4, it is presumed that they are not comfortable to sit on because they do not satisfy requirement (b).

[0063] The cushion bodies of Examples 1 to 5 were rated "A" and "B" for weight reduction, and were lighter than Comparative Example 1. The cushion bodies of Examples 1 to 5 were rated "B" and "C" for comfort, and were more comfortable to sit on than Comparative Example 2. The cushion bodies of Examples 1 to 5 were rated "B" for coolness, and were less likely to feel cold than Comparative Example 1.

[0064] (3) Satisfaction of each requirement in Examples 1 to 5 and Comparative Examples 1 and 2 Furthermore, the cushion bodies of Examples 1 to 5 satisfy all of the following requirements (f) and (g). Requirement (f): The cushion body is a laminate of a resin foam layer and a gel layer. Requirement (g): The F hardness on the resin foam layer side is 56 or less. In contrast, the cushion body of Comparative Example 1 does not satisfy requirement (f), and the cushion body of Comparative Example 2 does not satisfy requirement (g).

[0065] (4) Discussion Comparative Example 1 was rated "D" for weight reduction and "D" for coolness. Comparative Example 2 was rated "D" for comfort. The cushion bodies of Examples 1 to 5 were rated "A" and "B" for weight reduction, and were lighter than Comparative Example 1. The cushion bodies of Examples 1 to 5 were rated "B" and "C" for comfort, and were more comfortable to sit on than Comparative Example 2. The cushion bodies of Examples 1 to 5 were rated "B" for coolness, and were less likely to feel cold than Comparative Example 1.

[0066] 4. Effects of the Example According to the above-described embodiments, it is possible to provide a technique that can contribute to reducing the weight of the cushion body or reducing the cold feeling while maintaining good deflection characteristics.

[0067] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible. [Explanation of symbols]

[0068] 10...Cushion body 11...Gel layer 13...Resin foam layer 15...Film layer

Claims

1. A cushion body in which a resin foam layer and a gel layer are laminated, In the force-deflection curve (first SS curve) obtained when compressing from the resin foam layer side at a rate of 10 mm / min from 0% to 50%, The correlation coefficient R1 between the first SS curve and the approximation line of the first SS curve is 0.90≦R1 ２ A cushion body that satisfies the condition of ≦1.

0.

2. In the force-deflection curve (second SS curve) obtained when returning from a 50% compressed state to an unloaded state, The correlation coefficient R2 between the second SS curve and the approximation line of the second SS curve is 0.87≦R2 ２ The cushion body according to claim 1 , wherein the relationship ≦1.0 is satisfied.

3. 2. The cushion body according to claim 1, wherein a gradient a1 of an approximation line of the first SS curve satisfies 10≦a1≦32.

4. 3. The cushion body according to claim 2, wherein a gradient a2 of an approximate straight line of the second SS curve satisfies 10≦a2≦30.

5. A cushion body in which a resin foam layer and a gel layer are laminated, wherein the resin foam layer side has an F hardness of 56 or less.

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