TW201821662A - Net-like structure - Google Patents

Abstract

Provided is a net-like structure having a three-dimensional random loop bonded structure configured of a continuous linear body, wherein: the continuous linear body is a fiber formed of a resin which contains 45 mass% or more of a polystyrene-based thermoplastic elastomer as a main component; and the polystyrene-based thermoplastic elastomer is a mixture of a first triblock copolymer, said first triblock copolymer consisting of a styrene polymer block-an isoprene polymer block-a styrene polymer block, with a second triblock copolymer, said second triblock copolymer consisting of a styrene polymer block-a butadiene polymer block-a styrene polymer block and/or a styrene polymer block-a butadiene/isoprene copolymer block-a styrene polymer block.

Description

   Reticular structure   

The present invention relates to a mesh structure with low resilience, excellent durability, and no bottoming feeling. The mesh structure can be suitably used for beddings such as office chairs, furniture, sofas, and beds. Shock-absorbing materials used in trams, automobiles, two-wheelers, baby carriages, child seats, and other vehicle seats; shock-absorbing materials that have a lot of transportation opportunities such as sleeping bags and mattresses; floor mats; collisions , Anti-pinch pads, etc.

Currently, mesh structures are increasing as shock-absorbing materials used in beddings such as furniture, beds, and seats for vehicles such as trams, automobiles, and two-wheelers.

For example, Japanese Patent Application Laid-Open No. 2013-076201 (Patent Document 1) discloses a mesh structure, which is composed of a three-dimensional random loop joint structure, which uses a three-dimensional random loop joint structure system. The continuous linear body from 100 dtex to 100,000 dtex is bent to form a random loop, each loop is in contact with each other in a molten state, and most of the contact parts are welded, and the continuous linear system is composed of 10 masses. It is composed of a polyester thermoplastic elastomer of 90 parts by mass to 90 parts by mass, and a resin composition of 90 to 10 parts by mass of a polystyrene thermoplastic elastomer.

In addition, Japanese Patent Application Laid-Open No. 2003-012905 (Patent Document 2) discloses a shock absorbing body composed of an aggregate of a plurality of strands, and an aggregate system of the plurality of strands made of a thermoplastic elastomer. The formed plurality of strands are randomly bent and the contact portions are welded together. The thermoplastic elastic system is composed of the following composition, which is composed of 100 parts by weight of a thermoplastic polyester elastomer and 10 weights. From 900 to 900 parts by weight of an olefin-based and / or styrene-based thermoplastic elastomer, and from 0 to 100 parts by weight of a component of a modified polymer having an epoxy group or a derivative group in the molecule, and The Shore A hardness is 50 to 90.

    [Prior technical literature]         [Patent Literature]    

Patent Document 1: Japanese Patent Application Laid-Open No. 2013-076201.

Patent Document 2: Japanese Patent Application Laid-Open No. 2003-012905.

Although the mesh structure disclosed in Japanese Patent Application Laid-Open No. 2013-076201 (Patent Document 1) can obtain low resilience, it has the problems of low hardness and a bottoming feeling, and it has compression due to the large amount of hard components. The problem is that the residual stress becomes large and the durability is poor.

Although the shock absorbing body disclosed in Japanese Patent Application Laid-Open No. 2003-012905 (Patent Document 2) has a small compression residual strain, it has a high resilience, and therefore there is a problem that a low resilience cannot be obtained.

Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide a mesh structure having low resilience, excellent durability, and no bottoming feeling.

[1] A mesh structure having a three-dimensional random loop joint structure composed of a continuous linear body, and the continuous linear body is composed of a polystyrene-based thermoplastic elastomer as a main component of 45% by mass or more Polystyrene-based thermoplastic elastomer is a mixture of the first triblock copolymer and the second triblock copolymer; the first triblock copolymer is composed of styrene polymer blocks- An isoprene polymer block-a styrene polymer block; the second triblock copolymer is composed of a styrene polymer block-butadiene polymer block-styrene polymer block and At least one of a styrene polymer block-butadiene and an isoprene copolymer block-styrene polymer block.

[2] The mesh structure according to [1], wherein the content of styrene is 5 mass% or more and 45 mass% or less.

[3] The network structure according to the above [1] or [2, wherein the mass ratio of the second triblock copolymer to the first triblock copolymer is 0.25 or more and 2.20 or less.

[4] The mesh structure according to any one of the above [1] to [3], wherein the 40 ° C compressive residual strain is 40% or less.

[5] The mesh structure according to any one of the above [1] to [4], wherein the hysteresis loss due to compression is 35% or more.

[6] The mesh structure according to any one of the above [1] to [5], wherein the compression deflection coefficient is 10 or less.

[7] The mesh structure according to any one of the above [1] to [6], wherein the fiber diameter of the continuous linear body is 0.1 mm to 3.0 mm, and the thickness of the mesh structure is 5 mm to 300 mm the following.

[8] The mesh structure according to any one of the above [1] to [7], in which the tan δ at 25 ° C. measured by a dynamic viscoelasticity measuring device of the resin is 0.3 or more.

[9] The mesh structure according to any one of the above [1] to [8], wherein the Shore A hardness of the resin is 40 or more.

[10] The mesh structure according to any one of the above [1] to [9], wherein the mesh structure is used as a shock absorbing material, an impact absorbing material, or a buffer material.

[11] The mesh structure according to any one of the above [1] to [9], which is a shock absorbing material, an impact absorbing material, or a buffer material.

According to the present invention, it is possible to provide a mesh structure having low resilience, excellent durability, and no bottoming feeling.

Fig. 1 is a schematic diagram of compression and decompression tests in the hysteresis loss measurement of a mesh structure.

The network structure system of one embodiment of the present invention has a three-dimensional random loop joint structure composed of continuous linear bodies, and the continuous linear bodies are made of polystyrene-based thermoplastic elastomer as 45 mass% or more. The main component of the resin is polystyrene-based thermoplastic elastomer, which is a mixture of the first triblock copolymer and the second triblock copolymer. The first triblock copolymer is embedded by a styrene polymer. Segment-isoprene polymer block-styrene polymer block; the second triblock copolymer is composed of styrene polymer block-butadiene polymer block-styrene polymer And at least one of a styrene polymer block-butadiene and isoprene copolymer block-styrene polymer block. The continuous linear system in which the mesh structure of this embodiment forms a three-dimensional random loop joint structure is composed of a resin containing a polystyrene-based thermoplastic elastomer as a main component of 45% by mass or more, and the polystyrene-based thermoplastic The elastomer is a mixture of the first triblock copolymer and the second triblock copolymer, so it has low resilience, excellent durability, and no bottoming feeling. Here, the "bottom feeling" refers to, for example, the rigidity of the mesh structure when the load is applied from the upper surface of the mesh structure by the hand, and the floor directly contacts the lower surface of the mesh structure. Touch-like touch. The feeling of bottoming is sensed when the rigidity and resilience of the mesh structure are insufficient.

The mesh structure in this embodiment has a three-dimensional random loop joint structure composed of continuous linear bodies. In detail, the mesh structure of this embodiment has a three-dimensional random loop joining structure which is joined by bending a continuous linear body to form a random loop, and making the loops contact each other in a molten state. . That is, a "continuous linear body" refers to an object formed by connecting straight lines, curved lines, folded lines, and other lines. In addition, the "three-dimensional random loop joining structure" means that one or a plurality of continuous linear bodies are bent to form an arbitrary shape such as a loop shape having a plurality of sizes or directions, and the plurality of linear bodies forming an arbitrary shape are fused with each other. A three-dimensional structure in which at least a part of the states are joined by contact.

    {Continuous linear body}    

The continuous linear body is a fiber composed of a resin containing a polystyrene-based thermoplastic elastomer as a main component of 45% by mass or more, preferably 55% by mass or more, and more preferably 65% by mass or more. Here, the main component refers to the component that contains the most amount of the resin. The existence of the polystyrene thermoplastic elastomer contained in the continuous linear body is confirmed by the polystyrene peak of the infrared absorption spectrum, and the content rate of the polystyrene thermoplastic elastomer is determined by GPC (Gel Permeation Chromatography; Gel permeation chromatography). The upper limit of the content rate of the polystyrene-based thermoplastic elastomer contained in the continuous linear body may be 75% by mass or less.

In the continuous linear body of the mesh structure of this embodiment, from the viewpoint of ensuring excellent durability and low resilience of the mesh structure, the content of styrene is preferably 5 mass% or more and 45% by mass. Below, more preferably from 5 to 40% by mass, still more preferably from 7 to 40% by mass, even more preferably from 7 to 37% by mass, even more preferably from 10 to 35% by mass the following. The content of styrene was measured by ¹ H-NMR (Nuclear Magnetic Resonance; nuclear magnetic resonance). The "content rate of styrene" herein refers to the content ratio (mass%) of the repeating unit derived from the styrene monomer in the polystyrene thermoplastic elastomer based on the mass of the network structure.

    {Polystyrene-based thermoplastic elastomer}    

The polystyrene thermoplastic elastomer is a mixture of a first triblock copolymer and a second triblock copolymer; the first triblock copolymer is composed of a styrene polymer block and an isoprene polymer. Segment-styrene polymer block; the second triblock copolymer is composed of styrene polymer block-butadiene polymer block-styrene polymer block and styrene polymer block- It is composed of at least one of a copolymer block of butadiene and isoprene-a styrene polymer block. Since the polystyrene thermoplastic elastomer of the thermoplastic elastomer of this embodiment is a mixture of the first triblock copolymer and the second triblock copolymer, it has the following characteristics: low resilience, excellent durability, and No bottoming.

    (1st triblock copolymer)    

The first triblock copolymer is a triblock copolymer composed of a styrene polymer block, an isoprene polymer block, and a styrene polymer block. The first triblock copolymer contains an isoprene polymer block, thereby forming a network structure with low resilience. The presence of the first triblock copolymer and the content rate of the first triblock copolymer were measured by ¹ H-NMR.

The method for producing the first triblock copolymer is not particularly limited, and it can be produced by a known method. For example, it can be manufactured by any of anionic polymerization, cationic polymerization, plasma polymerization method, single site polymerization method, and radical polymerization method. When using an anionic polymerization method, the following methods (i) to (iii) can be cited, for example.

(i) A method of gradually polymerizing an aromatic vinyl compound (for example, a styrene monomer), isoprene, and an aromatic compound by using an alkyl lithium compound (for example, n-butyl lithium) as a polymerization initiator.

(ii) A method of using an alkyl lithium compound as a polymerization initiator to gradually polymerize an aromatic vinyl compound and isoprene, and then add a coupling agent to perform coupling.

(iii) A method in which a dilithium compound is used as a polymerization initiator to gradually polymerize isoprene and then an aromatic vinyl compound.

Here, the anionic polymerization is preferably performed in the presence of a solvent. The solvent is not particularly limited as long as it is inactive to the polymerization initiator and does not adversely affect the polymerization reaction. Examples thereof include saturated aliphatic hydrocarbons or aromatic hydrocarbons such as hexane, cyclohexane, heptane, octane, decane, toluene, benzene, and xylene.

In the case of using any one of the methods (i) to (iii), the polymerization reaction may be performed at a temperature of usually 0 ° C to 80 ° C, preferably 10 ° C to 70 ° C, and more preferably 10 ° C. It is carried out at a temperature of 60 ° C for 0.5 to 50 hours, preferably 1 to 30 hours.

    (Second Triblock Copolymer)    

The second triblock copolymer is a triblock copolymer composed of at least one of the following triblock copolymers: a styrene polymer block-butadiene polymer block-styrene polymer A triblock copolymer composed of the three blocks, and a styrene polymer block-butadiene and isoprene copolymer block-styrene polymer block, the three blocks The triblock copolymer formed. When the second triblock copolymer contains a butadiene polymer block or a copolymer block of butadiene and isoprene, a network structure having excellent durability is formed. The presence of the second triblock copolymer and the content rate of the second triblock copolymer were measured by ¹ H-NMR. A copolymer of butadiene and isoprene in a triblock copolymer composed of a styrene polymer block-butadiene and isoprene copolymer block-styrene polymer block In the segment, it is preferable that the repeating unit derived from butadiene monomer is at least 50% by mass or more. Furthermore, the butadiene and isoprene in a triblock copolymer composed of a styrene polymer block-butadiene and isoprene copolymer block-styrene polymer block In the copolymer block, butadiene and isoprene may be separately copolymerized as blocks, or may be randomly copolymerized with each other.

Regarding the manufacturing method of the second triblock copolymer, it is also possible to change the isoprene to butadiene (for example, 1,3-butadiene monomer) by using the same method as the first triblock copolymer. ) Or butadiene and isoprene.

From the viewpoint of ensuring excellent durability and low resilience of the network structure, the mass ratio of the second triblock copolymer to the first triblock copolymer is preferably 0.25 or more and 2.20 or less, and more preferably 0.30. The above is 2.10 or less, and more preferably 0.35 or more and 2.00 or less.

    {Other ingredients}    

From the standpoint of eliminating bottoming sensation (improving rigidity), the resin forming the continuous linear body of the mesh structure of this embodiment may contain a polyolefin (for example, polypropylene) in addition to a polystyrene thermoplastic elastomer, Paraffin-based process oil, hydrogenated terpene resin, and the like.

From the viewpoint of ensuring excellent durability, the mesh structure of this embodiment has a 40 ° C compressive residual strain of the mesh structure of preferably 40% or less, more preferably 35% or less, and still more preferably 30% or less. . The lower limit of the compression residual strain at 40 ° C is not particularly limited, and it is 1% or more in the mesh structure of this embodiment. Here, the compression residual strain at 40 ° C is based on the thickness t _b before compression and the thickness t _a after compression when the sample is subjected to 50% compression at an ambient temperature of 40 ° C for 22 hours, by (t _b -t _a ) / t _b × 100. The thickness of the sample before compression and the thickness after compression can be measured, for example, by the method described in the column of "(4) 40 ° C compression residual strain" in the examples described later.

From the viewpoint of ensuring low resilience, the mesh structure of this embodiment is preferably 35% or more, more preferably 38% or more, and even more preferably 40% or more due to compression. Furthermore, from the viewpoint of having a sufficient shape recovery speed as a mesh structure, the hysteresis loss due to compression is preferably 98% or less, and more preferably 95% or less. Here, the hysteresis loss due to compression is based on the compression energy WC represented by the stress curve during compression and the compression energy WC 'represented by the stress curve during decompression, and is expressed by (WC-WC') / WC × 100 And figure it out. The compression energy WC and the compression energy WC ′ can be obtained, for example, by a method described in a column of “(5) Hysteresis Loss” in Examples described later.

From the viewpoint that the net-like structure of the present embodiment does not feel bottoming, the compression deflection coefficient is preferably 10 or less, more preferably 9.9 or less, and even more preferably 9.8 or less. The lower limit value of the compressive deflection coefficient is not particularly limited, and it is 1.0 or more in the mesh structure of this embodiment. Here, the flexibility factor based compression hardness by ₆₅ H H ₆₅ / H ₂₅ 25 when calculated from the _25% compression and 65% compression hardness H. The compressive deflection coefficient can be obtained by a method described in the column of "(6) Compression deflection coefficient" in Examples described later.

The mesh structure of this embodiment is preferably 0.1 mm or more and 3.0 mm or less, and more preferably 0.2 in terms of obtaining the hardness necessary for the mesh structure and obtaining shock absorption. mm to 2.5 mm, more preferably 0.3 mm to 2.0 mm. The fiber diameter of a continuous linear body can be calculated | required by the method described in the column of "(7) fiber diameter" in the Example mentioned later, for example. In addition, from the viewpoint of eliminating the bottom contact feeling and the upper limit of the manufacturing device, the thickness of the mesh structure is preferably 5 mm or more and 300 mm or less, more preferably 7 mm or more and 280 mm or less, and even more preferably 10 mm or more and 250 mm or less. The thickness of the mesh structure can be obtained, for example, by a method described in the column of "(8) Thickness" in Examples described later.

From the viewpoint of ensuring low resilience, the mesh structure of this embodiment is preferably 0.3 or more, and more preferably 0.4 at 25 ° C. measured by a dynamic viscoelasticity measuring device for a resin forming a continuous linear body. The above is more preferably 0.5 or more, particularly preferably 0.6 or more. From the viewpoint of having a sufficient shape recovery speed as a mesh structure, the tan δ is preferably 2.0 or less, and more preferably 1.8 or less. The tan δ can be obtained, for example, by the method described in the column of "(9) tan δ" in the examples described later.

From the viewpoint of eliminating the bottoming feeling of the mesh structure of this embodiment, the Shore A hardness of the resin forming the continuous linear body is preferably 40 or more, more preferably 50 or more, and even more preferably 60 or more. From the viewpoint of ensuring low resilience, the Shore A hardness is preferably 80 or less, and more preferably 70 or less. The Shore A hardness can be obtained, for example, by a method based on the hardness tester A hardness measurement method prescribed in JIS (Japanese Industrial Standards) K6253-3: 2012.

The mesh structure of this embodiment is not particularly limited, and can be formed in various shapes, and examples thereof include a rectangular parallelepiped shape and a sheet shape.

The application of the mesh structure of this embodiment is preferably a shock absorbing material, an impact absorbing material, or a buffer material. That is, the mesh structure of this embodiment may be a shock absorbing material, an impact absorbing material, or a buffer material.

The mesh structure of this embodiment is obtained as follows, for example. The network structure system is obtained by a known method described in Japanese Patent Application Laid-Open No. 7-68061. For example, a polystyrene-based thermoplastic elastomer composed of a mixture of a first triblock copolymer and a second triblock copolymer is first distributed from a plurality of rows of nozzles having a plurality of orifices to the nozzle orifices. Then, at a spinning temperature higher than the melting point of the polystyrene thermoplastic elastomer or the glass transition temperature of the hard segment by more than 20 ° C and not more than 200 ° C, it is ejected downward from the nozzle, so that the continuous linear bodies are in a molten state with each other. Contact and fusion to form a three-dimensional structure. The continuous three-dimensional structure of the continuous linear body clamped by the extraction conveying net is cooled by cooling water in the cooling tank and then extracted. After the water is removed or dried, a smooth network structure is obtained on both sides or on one side. When only one surface is smoothed, it can also be sprayed onto an extraction net with a slope, so that continuous linear bodies are in contact with each other in a molten state and welded to form a three-dimensional structure, and only when the mesh surface is extracted, the shape is relaxed. Allow to cool. Then, the obtained mesh structure may be dried. The drying process of the mesh structure may be an annealing process.

For the annealing treatment, a device such as a hot-air drying furnace or a hot-air circulation furnace can be used. It is preferable to set the annealing temperature and the annealing time to a predetermined range. The annealing temperature is at least room temperature, preferably at least 50 ° C, more preferably at least 60 ° C, and even more preferably at least 70 ° C. The upper limit of the annealing temperature is not particularly limited, and it is preferably 10 ° C or more lower than the melting point or the glass transition temperature of the hard segment. The annealing treatment is preferably performed in a nitrogen atmosphere. The annealing time is preferably 1 minute or longer, more preferably 5 minutes or longer, even more preferably 10 minutes or longer, and even more preferably 20 minutes or longer.

    [Example]    

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. The measurement and evaluation of the characteristic values in the examples were performed as follows. In addition, the size of the sample is based on the size described below, but when the sample is insufficient, the measurement is performed using a sample size that is possible.

(1) Existence of polystyrene-based thermoplastic elastomer and content rate of the polystyrene-based thermoplastic elastomer

The existence of the polystyrene-based thermoplastic elastomer was performed by infrared absorption spectrum, and the content of the polystyrene-based thermoplastic elastomer was measured by GPC. As the measurement device, a gel permeation chromatography "L-7000 series" manufactured by Hitachi, Ltd. was used, and TSKgel G4000HXL × 2 tubes (manufactured by Tosoh Corporation) were used for the column, and tetrahydrofuran was used as the solvent. The measurement was performed under conditions of a flow rate of 1 ml / min, a concentration of 20 mg / 10 ml (sample / tetrahydrofuran), and a column temperature of 40 ° C. The peak area ratio of the polystyrene-based thermoplastic elastomer dissolved in tetrahydrofuran to other components was determined, and the ratio of the polystyrene-based thermoplastic elastomer in the tetrahydrofuran-soluble component was set to Awt%. A tetrahydrofuran-insoluble component was set to Bmg, and it was calculated from the content rate = A (1-B / 20).

(2) the existence of styrene and the content of styrene

Regarding the presence of styrene in the network structure and the measurement of the styrene content rate, the determination of the styrene content rate was performed by ¹ H-NMR measurement at a resonance frequency of 500 MHz. The measuring device was AVANCE500 manufactured by BRUKER, and the solvent was deuterated tetrachloroethane to which dimethyl isophthalate was added as a mass reference substance. The sample was dissolved in the solvent at 135 ° C, and the measurement was performed at 120 ° C. Take full repeat time. The measurement was performed according to the method described above, and the content of styrene was calculated by the following method.

In the obtained ¹ H-NMR spectrum, when tetrachloroethane was set to 6 ppm, a peak of 6.4 ppm to 7.3 ppm was a peak corresponding to styrene. The peak integration value of the above peaks was used for analysis (set = A). On the other hand, dimethyl isophthalate has peaks observed around 8.7 (1H), 8.35 (2H), 7.6 (1H), 4.0 ppm (6H), and the peaks that do not overlap with the constituent components of the sample are used. Integration value. Assuming a peak integration value of 7.6 ppm (set = B), the following formula (20.8 × A × Y × 100) / (194 × B × X) (mass% relative to the sample)

(Here, the sample amount was set to X (mg), and the mass of the dimethyl isophthalate contained in the measurement solution was set to Y (mg)), and the styrene content was calculated.

(3) Mass ratio of the second triblock copolymer to the first triblock copolymer

The component separation of the peaks obtained in the GPC measurement was performed, and a ¹ H-NMR spectrum was measured for each peak component. According to the 3,4-bond (4.8 ppm) and 1,2-bond (5.8 ppm) peaks derived from isoprene or a mixture of isoprene and butadiene and 1,4-bond ( 5.3 ppm), and the content (content ratio) of 3,4-bond and 1,2-bond was calculated. The content (content ratio) of the 3,4-bond and 1,2-bond is 45% or more in the first triblock copolymer and less than 45% in the second triblock copolymer. Each peak component is attributed to the first triblock copolymer and the second triblock copolymer. From the obtained GPC graph, the area ratio of each peak component of each of the first triblock copolymer and the second triblock copolymer was calculated to calculate the second triblock copolymer relative to the first triblock copolymer. Segment copolymer mass ratio.

(4) Compression residual strain at 40 ° C

The sample is cut into a size of 10cm × 10cm × sample thickness, and the measured sample of thickness t _b before compression is clamped in a mold that can be maintained in a 50% compression state, and is placed at a setting of 40 ° C ± 2 ° C. Let it stand in the dryer for 22 hours. Then remove the sample, remove the compressive strain, cool at room temperature (25 ° C), and determine the thickness t _a after compression for 30 minutes. Calculate the residual strain at 40 ° C from the formula (t _b -t _a ) / t _b × 100. : Unit% (average value of n = 3). Here, the thickness t _b before compression and the thickness t _a after compression refer to measuring the height of one sample of each sample before and after compression, and using the average value of the height as the thickness.

(5) Hysteresis loss

The sample was cut into a size of 10cm × 10cm × sample thickness, and left unloaded in an environment of 23 ° C. ± 2 ° C. for 24 hours, using a universal testing machine at 23 ° C. ± 2 ° C. (Japanese English An Instron universal testing machine manufactured by Instron Japan Co., Ltd.), arranging the sample so that the pressure plate with a diameter of 50 mm and a thickness of 3 mm is centered on the sample, and the speed is 10 mm / min The center of the sample was compressed, and the thickness when the load was 0.3N ± 0.05N detected by a universal testing machine was measured as the thickness of the hardness tester. Set the position of the pressure plate at this time to zero, compress it to 75% of the thickness of the hardness tester at a speed of 100 mm / min, and return the pressure plate to zero at the same speed without hold time. This state was maintained for 4 minutes (first stress-strain curve). After holding at zero for 4 minutes, it was compressed to 75% of the thickness of the hardness tester at a speed of 100 mm / min, and returned to zero at the same speed without a hold time (second stress-strain curve).

Referring to FIG. 1, in the second stress-strain curve of FIG. 1 (a), it is assumed that the compression energy (WC) represented by the stress-strain at the second compression of FIG. 1 (b), The compression energy (WC ') represented by the stress-strain curve during the second decompression is based on the following formula: Hysteresis loss (%) = (WC-WC') / WC × 100: Unit%

WC = ʃPdT (work amount when compressed from 0% to 75%)

WC '= ʃPdT (the amount of work when the pressure is reduced from 75% to 0%)

Find the hysteresis loss.

In brief, the above-mentioned hysteresis loss can be calculated by analyzing the data using a personal computer after obtaining a stress-strain curve as shown in FIG. 1. In addition, the area of the oblique line portion may be WC, the area of the grid portion may be WC ′, and the weight may be obtained by subtracting the difference between the areas (average value of n = 3).

(6) Compression deflection coefficient

The sample was cut to a size of 10 cm × 10 cm × sample thickness, and left to stand for 24 hours under a load-free condition at an environment of 23 ° C. ± 2 ° C., using a universal testing machine at an environment of 23 ° C. ± 2 ° C. (Japan (Instron Universal Co., Ltd., manufactured by Instron Japan Co., Ltd.), a sample with a diameter of 50 mm and a thickness of 3 mm is arranged so that it becomes the center of the sample, at 10 mm / min. The speed starts to compress the center of the sample, and the thickness when the load is 0.3N ± 0.05N detected by a universal testing machine is measured as the thickness of the hardness tester. The position of the pressure plate at this time is taken as the zero point, and after being compressed at a speed of 100 mm / min to 75% of the thickness of the hardness tester, the pressure plate is returned to the zero point at a speed of 100 mm / min, and maintained in this state for 4 minutes. After 4 minutes, it is compressed at a speed of 100mm / min to 25% and 65% of the thickness of the durometer, and the load at this time is measured as the hardness H _{25 at 25} % compression and the hardness H ₆₅ at 65% compression: Unit N / φ50 (average value of n = 3). Using the thus obtained 25% compression hardness H ₂₅ and 65% compression hardness H ₆₅ , the following formula (compressive deflection coefficient) = H ₆₅ / H ₂₅ : (average value of n = 3)

Calculate the compression deflection coefficient.

(7) Fiber diameter

The sample was cut into a size of 10 cm in the width direction × 10 cm in the length direction × the thickness of the sample, and 10 linear bodies were randomly collected from the cut section in the thickness direction with a length of about 5 mm. With respect to the collected linear bodies, an optical microscope was used to focus the fiber diameter measurement portion (the portion where the fiber diameter was measured) at an appropriate magnification, and the thickness of the fiber viewed from the fiber side (the side of the fiber) was measured. Furthermore, the surface of the mesh structure may be flattened to obtain smoothness, and the fiber cross section (cross section of the fiber) may be deformed. Therefore, samples should not be taken from a region within 2 mm from the surface of the mesh structure (the surface of the mesh structure).

(8) Thickness

Four samples were cut out in a width direction of 10 cm × length direction of 10 cm × sample thickness, and left for 24 hours under no load condition. Then, with the solid section fiber side (the fiber section side of the solid section) facing up, use a FD-80N type thickness gauge manufactured by a polymer meter to measure the height of each sample at a location using a circular measuring device with an area of 15 cm ² . Take the average of 4 samples as the thickness.

(9) tanδ

The sample was formed into a sheet sample having a thickness of 300 μm by hot pressing at a set temperature of 230 ° C., and the sheet sample was cut out with a length of 23 mm × a width of 5 mm. A dynamic viscoelasticity measuring device (Rheogel-E-4000 manufactured by UBM) was used to fix the 4 mm portions of both ends of the long side of the cut-out sheet sample with a stretching jig, at 30 Hz and a heating rate of 2 ° C. / The measurement was performed in min to obtain a value of tan δ (a ratio E "/ E 'of the loss elastic modulus E" to the storage elastic modulus E') at 23 ° C.

(10) Shore A hardness

The hardness is measured in accordance with the hardness meter A hardness measurement method specified in JIS K6253-3: 2012.

    (Synthesis example 1)    

In a 5L autoclave, 1800 g of cyclohexane, 30 g of styrene monomer and 0.32 g of n-butyllithium were added, followed by polymerization at 60 ° C. for 1 hour, followed by addition of 162 g of isoprene monomer and polymerization at 60 ° C. for 1 hour. Finally, 30 g of a styrene monomer was added, and polymerization was performed at 60 ° C for 1 hour. An equal amount of methanol was added to the living polymer solution to deactivate the solution, and then precipitated in a large amount of methanol, thereby recovering an isoprene-containing polystyrene thermoplastic elastomer (S-1). The styrene content of the obtained isoprene-containing polystyrene thermoplastic elastomer (S-1) was 30% by mass, and the weight average molecular weight was 170,000. The "isoprene-containing polystyrene thermoplastic elastomer (S-1)" as used herein refers to a first triblock copolymer.

    (Synthesis example 2)    

In a 5L autoclave, 1800 g of cyclohexane, 67.5 g of styrene monomer and 0.5 g of n-butyllithium were added, and polymerization was performed at 60 ° C for 1 hour, and then 315 g of 1,3-butadiene monomer was added and polymerized at 60 ° C 1 hour. Finally, 67.5 g of a styrene monomer was added and polymerized at 60 ° C. for 1 hour. An equal amount of methanol was added to the living polymer solution to deactivate the solution, and then precipitated in a large amount of methanol, thereby recovering a polystyrene-based thermoplastic elastomer (S-2) containing butadiene. The styrene content of the obtained butadiene-containing polystyrene-based thermoplastic elastomer (S-2) was 30% by mass, and the weight average molecular weight was 270,000. The "butadiene-containing polystyrene thermoplastic elastomer (S-2)" as used herein refers to a second triblock copolymer.

    (Example 1)    

The following nozzles are used. The nozzles are on the effective side of the nozzle with a length of 100 cm in the width direction and a length of 62.4 mm in the thickness direction. The shape of the hole is a solid formed hole with an outer diameter of 0.5 mm. Staggered arrangement with 5.2mm pitch between holes in the direction. That is, the shape of the effective surface of the nozzle is 100 cm in the width direction and 62.4 mm in the thickness direction. In addition, the orifices are solid-formed orifices with an outer diameter of 0.5 mm. The arrangement of the orifices is a staggered arrangement with a pitch of 6 mm in the width direction and a pitch of 5.2 mm in the thickness direction. The polystyrene-based thermoplastic elastomer (S-1) containing isoprene was 43.3% by mass, the polystyrene-based thermoplastic elastomer (S-2) containing butadiene was 21.7% by mass, and the paraffin-based process Oil (weight average molecular weight: 750) becomes 20% by mass, hydrogenated terpene resin (softening point: 150 ° C) becomes 5% by mass, polypropylene (tensile elastic modulus: 2000MPa, MFR (Melt Flow Rate; melt flow rate) ) (Measured at 230 ° C. in accordance with JIS K7210-1: 2014): 45 g / 10 min) was measured so as to be 10% by mass, and the mixture was sufficiently mixed in a pellet state to be used as a raw material. The obtained raw material mixture was sprayed under the nozzle at a spinning rate (melting temperature) of 200 ° C. at a rate of 1.5 g / min per hole in a molten state. The structure below the nozzle is as follows. Cooling water is arranged under the nozzle surface 21cm, and a thermal insulation tube with a length of 50mm is directly below the nozzle between the nozzle and the cooling water. A stainless steel endless net with a width of 300mm is parallel to the water surface with an opening width of 50mm. A pair of extraction conveyors are arranged in a partially exposed manner. According to the above-mentioned configuration, the molten state of the discharge is bent linearly to form a loop, and the contact portions are welded to form a three-dimensional network structure. While the two sides of the mesh structure in the molten state obtained were held by the extraction conveyor belt, they were introduced into cooling water at a speed of 1.0 m per minute to solidify and flatten the two sides. Then, it was cut to a predetermined size and subjected to annealing treatment at 70 ° C. for 30 minutes to obtain a mesh structure. With respect to the obtained mesh structure, each physical property value was obtained in accordance with the above (1) to (10). The results are summarized in Table 1.

    (Example 2)    

Measured so that the polystyrene-based thermoplastic elastomer (S-1) containing isoprene is 50.0% by mass and the polystyrene-based thermoplastic elastomer (S-2) containing butadiene is 15.0% by mass, Except for this, a mesh structure was obtained in the same manner as in Example 1. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Example 3)    

Measured so that the polystyrene-based thermoplastic elastomer (S-1) containing isoprene is 38.2% by mass and the polystyrene-based thermoplastic elastomer (S-2) containing butadiene is 26.8% by mass, Except for this, a mesh structure was obtained in the same manner as in Example 1. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Example 4)    

Measured such that the polystyrene-based thermoplastic elastomer (S-1) containing isoprene is 21.7 mass% and the polystyrene-based thermoplastic elastomer (S-2) containing butadiene is 43.3 mass%, Except for this, a mesh structure was obtained in the same manner as in Example 1. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative example 1)    

A net-like structure was obtained in the same manner as in Example 1 except that the polystyrene-based thermoplastic elastomer (S-1) containing isoprene was measured so as to be 100% by mass. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative example 2)    

A net-like structure was obtained in the same manner as in Example 1 except that the polystyrene-based thermoplastic elastomer (S-2) containing butadiene was measured so as to be 100% by mass. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative example 3)    

The polybutadiene-containing thermoplastic elastomer (S-2) containing butadiene was made 20% by mass and soft polypropylene (hardness (according to ASTM (American Society for Testing and Materials) D2240 at 23 ° C) (Measurement): 61A, MFR (melt flow rate) (measured at 190 ° C in accordance with JIS K7210-1: 2014): 17g / 10min) was measured so as to become 80% by mass, and was the same as in Example 1 except that it was measured. In this way, a mesh structure is obtained. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative Example 4)    

The isoprene-containing polystyrene thermoplastic elastomer (S-1) was 65% by mass, the paraffin-based process oil (weight average molecular weight: 750) was 20% by mass, and the hydrogenated terpene resin (softening point: 150) ℃) to 5 mass%, polypropylene (tensile elastic modulus: 2000 MPa, MFR (melt flow rate) (measured at 230 ° C. according to JIS K7210-1: 2014): 45 g / 10min) to 10 mass% Except for the measurement, a mesh structure was obtained in the same manner as in Example 1. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative example 5)    

The butadiene-containing polystyrene-based thermoplastic elastomer (S-2) was 75% by mass, the paraffin-based process oil (weight-average molecular weight: 750) was 10% by mass, and the hydrogenated terpene resin (softening point: 150 ° C) ) 5% by mass, polypropylene (tensile elastic modulus: 2000 MPa, MFR (melt flow rate) (measured at 230 ° C in accordance with JIS K7210-1: 2014): 45g / 10min) was measured as 10% by mass Except for this, a mesh structure was obtained in the same manner as in Example 1. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative Example 6)    

15% by mass of polystyrene-based thermoplastic elastomer (S-2) containing butadiene, soft polypropylene (hardness (measured at 23 ° C according to ASTM D2240): 61A, MFR (melt flow rate) ( Measured in accordance with JIS K7210-1: 2014 at 190 ° C): 17g / 10min) to 80% by mass, and a paraffin-based process oil (weight average molecular weight: 750) to 5% by mass. 1A mesh structure was obtained in the same manner. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative Example 7)    

The isoprene-containing polystyrene-based thermoplastic elastomer (S-1) was 66.7% by mass, the butadiene-containing polystyrene-based thermoplastic elastomer (S-2) was 13.3% by mass, and the paraffin-based process Oil (weight average molecular weight: 750) becomes 10% by mass, hydrogenated terpene resin (softening point: 150 ° C) becomes 5% by mass, polypropylene (tensile elastic modulus: 2000MPa, MFR (melt flow rate) (according to JIS K7210-1: Measured at 230 ° C in 2014): 45 g / 10 min) was measured in such a manner as to be 5 mass%, and a mesh structure was obtained in the same manner as in Example 1. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

    (Comparative Example 8)    

The polystyrene-based thermoplastic elastomer (S-1) containing isoprene was 22.9% by mass, the polystyrene-based thermoplastic elastomer (S-2) containing butadiene was 57.1% by mass, and the paraffin-based process Oil (weight average molecular weight: 750) becomes 10% by mass, hydrogenated terpene resin (softening point: 150 ° C) becomes 5% by mass, polypropylene (tensile elastic modulus: 2000MPa, MFR (melt flow rate) (according to JIS K7210-1: Measured at 230 ° C in 2014): 45 g / 10 min) was measured in such a manner as to be 5 mass%, and a mesh structure was obtained in the same manner as in Example 1. With respect to the obtained mesh structure, each physical property value was obtained in the same manner as in Example 1. The results are summarized in Table 1.

With reference to Table 1, the mesh structure systems of Examples 1 to 4 contain 45% by mass or more of a polystyrene-based thermoplastic elastomer, and the content ratio of styrene is 5% by mass or more and 40% by mass or less. The ratio of the block copolymer to the first triblock copolymer is in the range of 0.25 or more and 0.75 or less. With such a structure, the hysteresis loss of the net-like structure system of Examples 1 to 4 is 35% or more, tan δ is 0.3 or more, and the Shore A hardness is 80 or less, so it has low resilience. In addition, the reticular structure systems of Examples 1 to 4 have a compression residual strain of 40% or less at 40 ° C, so they have excellent durability, a compression deflection coefficient of 10 or less, a thickness of 5 mm or more, and a Shore A hardness of 40 or more. , So there is no bottoming. Since the mesh structure of Comparative Example 1 does not contain the second triblock copolymer, it has a Shore A hardness of more than 80, so it cannot be said to have low resilience, and its residual strain at 40 ° C is greater than 40, which results in poor durability. Since the mesh structure of Comparative Example 2 does not contain the first triblock copolymer, the hysteresis loss is less than 35% and the tan δ is less than 0.3, so it is not low resilience, and the compression deflection coefficient is greater than 10, so there is a bottoming feeling. Since the net structure of Comparative Example 3 has a styrene content of less than 5% by mass and does not contain a first triblock copolymer, tan δ is less than 0.3 and the Shore A hardness is greater than 80. Compressive residual strain at 40 ° C is inferior to durability.

It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is expressed by the scope of patent application rather than the above description, and means all changes within the meaning and scope equivalent to the scope of patent application.

Claims (10)

    A mesh structure having a three-dimensional random loop joint structure composed of continuous linear bodies; the continuous linear system is composed of a resin containing polystyrene-based thermoplastic elastomer as a main component of 45% by mass or more Fiber; the aforementioned polystyrene thermoplastic elastomer is a mixture of a first triblock copolymer and a second triblock copolymer; the aforementioned first triblock copolymer is a styrene polymer block-isoprene Olefin polymer block-styrene polymer block; the second triblock copolymer is composed of styrene polymer block-butadiene polymer block-styrene polymer block and styrene polymerization At least one of a polymer block-butadiene and an isoprene copolymer block-a styrene polymer block.         The mesh structure according to claim 1, wherein the content of styrene is 5 mass% or more and 45 mass% or less.         The network structure according to claim 1 or 2, wherein the mass ratio of the second triblock copolymer to the first triblock copolymer is 0.25 or more and 2.20 or less.         The mesh structure according to any one of claims 1 to 3, wherein the 40 ° C compressive residual strain is 40% or less.         The mesh structure according to any one of claims 1 to 4, wherein the hysteresis loss due to compression is 35% or more.         The mesh structure according to any one of claims 1 to 5, wherein the compressive deflection coefficient is 10 or less.         The mesh structure according to any one of claims 1 to 6, wherein a fiber diameter of the continuous linear body is 0.1 mm to 3.0 mm, and a thickness of the mesh structure is 5 mm to 300 mm.         The mesh structure according to any one of claims 1 to 7, wherein the tan δ at 25 ° C measured by the dynamic viscoelasticity measuring device of the resin is 0.3 or more.         The mesh structure according to any one of claims 1 to 8, wherein the Shore A hardness of the resin is 40 or more.         The mesh structure according to any one of claims 1 to 9, wherein the use of the mesh structure is a shock absorbing material, an impact absorbing material, or a buffer material.