KR20190028459A - Network structure - Google Patents

Abstract

The present invention relates to a reticulated structure having a three-dimensional random loop bonding structure comprising a continuous linear body, wherein the continuous strand is a fiber comprising a resin containing a polystyrene type thermoplastic elastomer as a main component of at least 45% by mass thereof, and the polystyrene type thermoplastic elastomer is styrene A first triblock copolymer comprising a polymer block-isoprene polymer block-styrene polymer block, at least one of a styrene polymer block-butadiene polymer block-styrene polymer block and a styrene polymer block-butadiene and isoprene copolymer block- Which is a mixture of the first and second triblock copolymers.

Description

Network structure

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material used for an office chair, a furniture, a sofa, a bed, a seat for a vehicle such as a train, a motorcycle, a motorcycle, a baby carriage, a car seat, a cushioning material, , A mattress for absorbing shocks such as an anti-jamming member, and the like, and is excellent in durability and has no bottom contact feeling.

At present, as a cushioning material used for a seat for a vehicle such as a bed of a furniture, a bed, a train, a car, a two-wheeled vehicle, a reticular structure is increasing.

For example, Japanese Patent Application Laid-Open No. 2013-076201 (Patent Document 1) discloses a method of forming a random loop by bending a continuous strand of 100 to 100,000 decitex to form a random loop, And a three-dimensional random loop bonding structure obtained by fusing a majority of the contact portions, wherein the continuous linear body is a resin composition comprising 10 to 90 parts by mass of a polyester-based thermoplastic elastomer and 90 to 10 parts by mass of a polystyrene-based thermoplastic elastomer And discloses a structured network.

Japanese Patent Application Laid-Open No. 2003-012905 (Patent Document 2) discloses a cushion body comprising a plurality of strands formed of a thermoplastic elastomer and randomly twisted and welded to each other, Wherein the thermoplastic elastomer is composed of the following 100 parts by weight of a thermoplastic polyester elastomer, 10 to 900 parts by weight of an olefinic and / or styrenic thermoplastic elastomer, and 0 to 100 parts by weight of a modified polymer having an epoxy group or a derivative thereof in the molecule And a Shore A hardness of 50 or more and 90 or less.

Japanese Patent Application Laid-Open No. 2013-076201 Japanese Patent Application Laid-Open No. 2003-012905

The network structure disclosed in Japanese Patent Application Laid-Open No. 2013-076201 (Patent Document 1) has low rebound characteristics but has a low hardness and a bottom contact feeling. Further, since the amount of hard component is large, And the durability is deteriorated.

The cushion body disclosed in Japanese Patent Application Laid-Open No. 2003-012905 (Patent Document 2) has a problem that low rebound characteristics can not be obtained because the compression residual deformation is small, but the repulsive force is high.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the problems described above and to provide a network structure which is low in resilience, has excellent durability, and has no bottom contact feeling.

[1] A network structure having a three-dimensional random loop bonding structure composed of a continuous linear body, wherein the continuous strand is a fiber comprising a resin containing a polystyrene type thermoplastic elastomer as a main component of at least 45% by mass thereof, and the polystyrene type thermoplastic elastomer is styrene A first triblock copolymer comprising a polymer block-isoprene polymer block-styrene polymer block, at least one of a styrene polymer block-butadiene polymer block-styrene polymer block and a styrene polymer block-butadiene and isoprene copolymer block- Wherein the second triblock copolymer is a mixture of the first triblock copolymer and the second triblock copolymer.

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

[3] The network structure according to [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 network structure according to any one of [1] to [3], wherein the compression set at 40 ° C is 40% or less.

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

[6] The network structure according to any one of [1] to [5], wherein the compression and flexural modulus is 10 or less.

[7] The network structure according to any one of [1] to [6], wherein the continuous filament has a fiber diameter of 0.1 mm or more and 3.0 mm or less and a thickness of the network structure is 5 mm or more and 300 mm or less.

[8] The network according to any one of [1] to [7], wherein the resin has a tan δ at 25 ° C. of not less than 0.3 as measured using a dynamic viscoelasticity measuring apparatus.

[9] The network according to any one of [1] to [8], wherein the resin has a Shore A hardness of 40 or more.

[10] The network structure according to any one of [1] to [9], wherein the use of the network structure is a cushioning material, a shock absorber, or a buffer material.

[11] The network structure according to any one of [1] to [9], which is a cushioning material, a shock absorber, or a buffer material.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a network structure that is low in resilience, has excellent durability, and has no bottom contact feeling.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic graph of a compression / suppression test in hysteresis loss measurement of a network structure. Fig.

A network structure according to one embodiment of the present invention is a network structure having a three-dimensional random loop bonding structure composed of a continuous linear body, wherein the continuous strand is composed of a resin comprising a resin containing a polystyrene type thermoplastic elastomer as a main component of at least 45 mass% , And the polystyrene-based thermoplastic elastomer comprises a first triblock copolymer composed of a styrene polymer block-isoprene polymer block-styrene polymer block, a styrene polymer block-butadiene polymer block-styrene polymer block, and a styrene polymer block-butadiene and isoprene And a second triblock copolymer composed of at least one of a copolymer block and a styrene polymer block. The network structure of the present embodiment is characterized in that the continuous linear body forming the three-dimensional random loop bonding structure is composed of a resin containing a polystyrene type thermoplastic elastomer as a main component of 45 mass% or more and the polystyrene type thermoplastic elastomer is composed of a first triblock copolymer Is a mixture of the first and second triblock copolymers, it is low rebound, has excellent durability, and has no bottom contact feeling. Here, the " bottom contact feeling " means, for example, when a load is applied from the upper surface of the network structure to the rigid surface such as the bottom surface of the network structure that is compressed by the hand and is in contact with the lower surface of the network structure It means the texture. The bottom contact feeling is perceived when the rigidity and repulsive force of the network structure is insufficient.

The network structure of the present embodiment has a three-dimensional random loop junction structure composed of a continuous linear body. Specifically, the network structure of the present embodiment has a three-dimensional random loop junction structure in which a continuous loop is formed by winding a continuous strand to form a random loop, and the loops are in contact with each other in a molten state. That is, the term " continuous line body " means an object formed in a straight line, a curved line, a line, or the like formed on a line. The term " three-dimensional random loop bonding structure " means a structure in which a plurality of arbitrary shapes such as a loop-like shape having irregular size or direction are formed by winding one or a plurality of continuous wire- Refers to a three-dimensional structure in which at least a part of the plurality of linear members is in contact with each other in a molten state.

{Continuous line upper body}

The continuous strand is a fiber made of a resin containing a polystyrene type thermoplastic elastomer as a main component of at least 45 mass%, preferably at least 55 mass%, more preferably at least 65 mass%. Here, the main component means a component contained in the resin in the largest amount. The presence of the polystyrene type thermoplastic elastomer contained in the continuous strand is confirmed by the polystyrene peak of the infrared absorption spectrum, and the content thereof is measured by GPC (gel permeation chromatography). The upper limit of the content of the polystyrene-based thermoplastic elastomer contained in the continuous strand may be 75% by mass or less.

In the continuous strand of the network structure of the present embodiment, the content of styrene is preferably 5% by mass or more and 45% by mass or less, more preferably 5% by mass or more, from the viewpoint of ensuring excellent durability of the network- More preferably 7 mass% or more and 40 mass% or less, still more preferably 7 mass% or more and 37 mass% or less, and still more preferably 10 mass% or more and 35 mass% or less. The content of styrene is measured by ¹ H-NMR. Here, the "content ratio of styrene" refers to the content (% by mass) of the repeating units derived from the styrene monomer in the polystyrene-based thermoplastic elastomer based on the mass of the reticulated structure.

{Polystyrene-based thermoplastic elastomer}

The polystyrene-based thermoplastic elastomer comprises a first triblock copolymer composed of a styrene polymer block-isoprene polymer block-styrene polymer block, a styrene polymer block-butadiene polymer block-styrene polymer block and a styrene polymer block-a copolymer of butadiene and isoprene And a block-styrene polymer block. The thermoplastic elastomer of the present embodiment has low rebound characteristics, excellent durability and no floor contact feeling because the polystyrene thermoplastic elastomer is a mixture of the first triblock copolymer and the second triblock copolymer .

(First triblock copolymer)

The first triblock copolymer is a triblock copolymer composed of three blocks of a styrene polymer block-isoprene polymer block-styrene polymer block. The first triblock copolymer includes an isoprene polymer block to form a low repellency reticulated structure. The presence of the first triblock copolymer and its content are measured by ¹ H-NMR.

The method for producing the first triblock copolymer is not particularly limited and can be produced by a known method. For example, it may be produced by any of an ion polymerization method such as anionic polymerization or cationic polymerization, a single site polymerization method, and a radical polymerization method. In the case of the anionic polymerization method, for example, the following methods (i) to (iii) can be mentioned.

(i) A method in which an aromatic vinyl compound (for example, styrene monomer), isoprene, and an aromatic compound are sequentially polymerized by using an alkyl lithium compound (e.g., n-butyl lithium) as a polymerization initiator.

(ii) a method in which an aromatic vinyl compound and isoprene are sequentially polymerized using an alkyl lithium compound as a polymerization initiator, and then a coupling agent is added to perform coupling.

(iii) a method in which a di-lithium compound is used as a polymerization initiator and isoprene and an aromatic vinyl compound are successively polymerized.

Here, the anionic polymerization is preferably carried out in the presence of a solvent. The solvent is not particularly limited as long as it is inert to the polymerization initiator and does not adversely affect the polymerization reaction. For example, saturated aliphatic hydrocarbons or aromatic hydrocarbons such as hexane, cyclohexane, heptane, octane, decane, toluene, benzene, and xylene can be mentioned.

The polymerization reaction is carried out at a temperature of usually 0 to 80 ° C, preferably 10 to 70 ° C, more preferably 10 to 60 ° C, in any of the above-mentioned methods (i) to (iii) For 0.5 to 50 hours, preferably 1 to 30 hours.

(Second triblock copolymer)

The second triblock copolymer comprises a triblock copolymer consisting of three blocks of styrene polymer block-butadiene polymer block-styrene polymer block and three blocks of styrene polymer block-butadiene and isoprene copolymer block- A triblock copolymer composed of at least one of triblock copolymers composed of triblock copolymers. The second triblock copolymer includes a butadiene polymer block or a copolymer block of butadiene and isoprene to form a network structure having excellent durability. The presence of the second triblock copolymer and its content are measured by ¹ H-NMR. In the copolymer block of butadiene and isoprene in the triblock copolymer composed of the styrene polymer block-butadiene and isoprene copolymer block-styrene polymer block, the content of the repeating unit derived from the butadiene monomer is at least 50 mass% . Also, in the butadiene and isoprene copolymer blocks in the triblock copolymer composed of the styrene polymer block-butadiene and the isoprene copolymer block-styrene polymer block, the butadiene and the isoprene may be respectively copolymerized as a block , Or may be randomly copolymerized with each other.

The method for producing the second triblock copolymer can also be produced by changing isoprene to butadiene (for example, 1,3-butadiene monomer) or butadiene and isoprene in the same manner as for the first triblock copolymer.

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

{Other components}

The resin forming the continuous stranded structure of the network structure of the present embodiment is not limited to polyolefin (for example, polypropylene), paraffinic process oil (for example, polypropylene) , Hydrogenated terpene resins, and the like.

The reticulated structure of the present embodiment is preferably 40% or less, more preferably 35% or less, and most preferably 30% or less of the compression residual strain at 40 캜 from the viewpoint of securing excellent durability. The lower limit value of the compression residual deformation at 40 占 폚 is not specifically defined, but it is 1% or more in the network structure of the present embodiment. Here, the compressive residual strain is 40 _{℃, (t b -t a) /} t b × 100 from the thickness t _b and t _a thickness after compression before compression when compressing the sample to 50% 22 hours in an ambient temperature of 40 ℃ . The thickness before compression and the thickness after compression of the sample can be measured, for example, by the method described in the column of "(4) 40 ° C compression residual deformation" in Examples to be described later.

The hysteresis loss due to compression is preferably 35% or more, more preferably 38% or more, and still more preferably 40% or more from the viewpoint of ensuring low rebound characteristics of the network structure of the present embodiment. From the viewpoint of having a shape recovery speed sufficient as a network structure, the hysteresis loss due to compression is preferably 98% or less, more preferably 95% or less. Here, the hysteresis loss due to compression is calculated by (WC-WC ') / WCx100 from the compression energy WC indicated by the stress curve at compression and the compression energy WC' indicated by the stress curve at the time of compression. The compression energy WC and the compression energy WC 'can be obtained, for example, by the method described in the column of (5) hysteresis loss in the embodiment described later.

The mesh structure of the present embodiment is preferably 10 or less, more preferably 9.9 or less, and even more preferably 9.8 or less in view of not feeling bottom contact. The lower limit value of the compression and flexural modulus is not particularly specified, but it is 1.0 or more for the network structure of the present embodiment. Here, the compressive flexural modulus is calculated from hardness H ₂₅ at 25% compression and hardness H ₆₅ at 65% compression, and H ₆₅ / H ₂₅ . The compression and flexural modulus can be obtained by the method described in the column of "(6) compression and flexural modulus" in Examples described later.

The fiber diameter of the continuous strand is preferably not less than 0.1 mm and not more than 3.0 mm, more preferably not less than 0.2 mm and not more than 2.5 mm from the viewpoint of achieving hardness required as a network structure and cushioning property, More preferably 0.3 mm or more and 2.0 mm or less. The fiber diameter of the continuous filament can be obtained by, for example, the method described in the column of "(7) fiber diameter" in Examples to be described later. The thickness of the network structure is preferably 5 mm or more and 300 mm or less, more preferably 7 mm or more and 280 mm or less, and further preferably 10 mm or more and 250 mm or less, from the viewpoint of eliminating the bottom contact feeling and the upper limit of the manufacturing apparatus. The thickness of the network structure can be obtained, for example, by the method described in the column of " (8) thickness " in Examples to be described later.

The network structure of the present embodiment preferably has a tan? At 25 占 폚 measured using a dynamic viscoelasticity measuring apparatus for a resin forming a continuous strand is preferably at least 0.3, more preferably at least 0.4 More preferably 0.5 or more, and particularly preferably 0.6 or more. Further, from the viewpoint of having a shape recovery speed sufficient as a network structure, the tan? Is preferably 2.0 or less, more preferably 1.8 or less. The tan delta can be obtained, for example, by the method described in the column of " (9) tan delta " in Examples described later.

The shore A hardness of the resin forming the continuous strand is preferably 40 or more, more preferably 50 or more, and even more preferably 60 or more from the viewpoint of eliminating the bottom contact feeling in the network structure of the present embodiment. Further, from the viewpoint of ensuring low rebound 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 in accordance with the measurement method of durometer A hardness specified in JIS K6253-3: 2012.

The network structure of the present embodiment can be formed into various shapes without particular limitation, and examples thereof include a rectangular parallelepiped shape and a sheet shape.

The use of the network structure of the present embodiment is preferably a cushioning material, a shock absorber, or a cushioning material. That is, the network structure of the present embodiment may be a cushioning material, a shock absorber, or a cushioning material.

The network structure of the present embodiment is obtained, for example, as follows. The network structure is obtained on the basis of a known method described in JP-A-7-68061 or the like. For example, first, a polystyrene-based thermoplastic elastomer comprising a mixture of a first triblock copolymer and a second triblock copolymer is distributed from a multi-row nozzle having a plurality of orifices to a nozzle orifice. Thereafter, at a spinning temperature higher than the melting point of the polystyrene-based thermoplastic elastomer or the glass transition temperature of the hard segment by 20 占 폚 or more and less than 200 占 폚, they are discharged downward from the nozzle, and the continuous strands are mutually fused and fused in a molten state Dimensional structure. The obtained three-dimensional structure of the continuous strand is sandwiched between the pick-up conveyor nets, cooled with cooling water in a cooling bath, drawn out, and then dried or dried to obtain a network structure having both sides or one side smoothed. In the case of smoothing only the single side, it is only necessary to cool the shape of the take-out net while relieving the shape while discharging it on the take-up net having the inclination and fusing it in contact with each other in the molten state. Thereafter, the resultant network structure may be subjected to a drying treatment. Further, the drying treatment of the network structure may be an annealing treatment.

As the annealing treatment, a device such as a hot air drying furnace or a hot air circulating furnace can be used. It is preferable to set the annealing temperature and the annealing time within a predetermined range. The annealing temperature is room temperature or higher, preferably 50 ° C or higher, more preferably 60 ° C or higher, and even more preferably 70 ° C or higher. The upper limit value of the annealing temperature is not specifically defined, but is preferably lower than the melting point or the glass transition temperature of the hard segment by 10 占 폚 or more. 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 particularly preferably 20 minutes or longer.

Example

EXAMPLES Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto. Measurement and evaluation of the characteristic values in the examples were carried out as follows. In addition, the size of the sample is the standard described below. When the sample is insufficient, the sample size is used to measure the size of the sample.

(1) Presence and content of polystyrene type thermoplastic elastomer

The presence of the polystyrene-based thermoplastic elastomer was measured by infrared absorption spectroscopy and the content thereof was measured by GPC. A gel permeation chromatograph "L-7000 series" manufactured by Hitachi Seisakusho Co., Ltd., and two TSKgel G4000HXL × 2 columns (manufactured by Tosoh Corporation) were used for the measurement apparatus, and tetrahydrofuran was used as the solvent. Flow rate: 1 ml / min, concentration: 20 mg / 10 ml (sample / tetrahydrofuran), column temperature: 40 占 폚. The peak area ratio of the polystyrene type thermoplastic elastomer dissolved in tetrahydrofuran and other components is determined, and the ratio of the polystyrene type thermoplastic elastomer in the tetrahydrofuran dissolving component is defined as Awt%. The component insoluble in tetrahydrofuran was used as Bmg, and the content was calculated from the content = A (1-B / 20).

(2) presence of styrene and its content

The presence of styrene in the reticulated structure and the content thereof were determined. The content of styrene was determined by ¹ H-NMR measurement at a resonance frequency of 500 MHz. The measuring apparatus used was AVANCE500 manufactured by BRUKER, and tetrachloroethane was used as the solvent, in which dimethyl isophthalate was added as a reference substance for mass. The sample was dissolved in the solvent at 135 占 폚 and the measurement was carried out at 120 占 폚. The repetition time was sufficient. Measurement was carried out according to the above method, and the content of styrene was calculated in the following manner.

In the obtained ¹ H-NMR spectrum, when the amount of tetrachloroethane was 6 ppm, the peak of 6.4 to 7.3 ppm was a peak corresponding to styrene. The peak integral value (= A) was used for the analysis. On the other hand, the peak of dimethyl isophthalate was observed near 8.7 (1H), 8.35 (2H), 7.6 (1H) and 4.0 ppm (6H), and the integral value of the peak which did not overlap with the sample constituent was used. For example, using a peak integral value (= B) of 7.6 ppm,

(20.8 x A x Y x 100) / (194 x B x X) (mass% based on the sample)

(Where X (mg) is a sample amount and Y (mg) is the mass of dimethyl isophthalate contained in the measurement solution).

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

The components of the peaks obtained in the above GPC measurement were aliquoted, and ¹ H-NMR spectrum was measured for each peak component. (4.8 ppm) and 1,2-bond (5.8 ppm) and 1,4-bond (5.3 ppm) peaks derived from a mixture of isoprene or isoprene and butadiene, 3,4- And the content (content ratio) of the 1,2-bond was calculated. Since the content (content ratio) of the 3,4-bond and the 1,2-bond is 45% or more in the first triblock copolymer and less than 45% in the second triblock copolymer, Triblock copolymer and a second triblock copolymer. In the GPC chart obtained, the mass ratios of the second triblock copolymers to the first triblock copolymers were determined by the ratio of the area of each peak component attributed to each of the first triblock copolymer and the second triblock copolymer to Respectively.

(4) 40 캜 Compression residual strain

The sample was cut into a size of 10 cm × 10 cm × sample thickness, and a sample in which the thickness t _b before compression was measured was inserted into a jig capable of maintaining 50% compression, placed in a drier set at 40 ± 2 ° C., . After taking out the sample, and removing the compressed and deformed, and then cooled at room temperature (25 ℃) to obtain a thickness t _a after compression after 30 minutes allowed to stand, formula _{(t b -t a) / t} b 40 ℃ compressed from × 100 Residual strain was calculated: unit% (n = 3 mean value). Here, the pre-compression thickness t _b and the post-compression thickness t _a are obtained by measuring the height of each sample before compression and after compression, and the average value thereof is defined as the thickness.

(5) Hysteresis loss

The sample was cut into a size of 10 cm × 10 cm × sample thickness and allowed to stand for 24 hours under no load under an environment of 23 ° C. ± 2 ° C. The test piece was placed in a universal testing machine (Instron Japan Co., Ltd., A universal testing machine) was used to place a sample with a sample of 50 mm in diameter and 3 mm in thickness centered at the center of the specimen. The center of the sample was compressed at a rate of 10 mm / min. When the load was detected as 0.3 N 0.05 N Was measured to determine the thickness of the hardness meter. At this time, the pressure plate was compressed to 75% of the thickness of the hardness meter at a speed of 100 mm / min at a zero point, and the pressure plate was returned to the zero point at the same rate without holding time and maintained for 4 minutes in this state Strain curve). Held at zero point for 4 minutes, compressed to 75% of the thickness of the durometer at a speed of 100 mm / min, and returned to zero point at the same rate with no hold time (second strain curve).

1, the compression energy WC indicated by the stress-strain curve at the second compression in Fig. 1 (b) and the compression energy Wc shown in Fig. 1 (b) are plotted in the second- (WC ') indicated by the stress-strain curves at the time of the second depressurization of the compressor

Hysteresis loss (%) = (WC-WC ') / WC 占 100: unit%

WC = ∫PdT (the amount when compressed from 0% to 75%)

WC '= ∫PdT (the amount when the pressure is reduced from 75% to 0%)

The hysteresis loss was obtained.

The hysteresis loss can be calculated simply by data analysis by a personal computer, for example, if a stress deformation curve as shown in Fig. 1 is obtained. Further, the area of the oblique line portion may be defined as WC, and the area of the portion into which the halftone dot is inserted may be determined as WC ', and the difference may be obtained from the weight of the portion where the area difference is removed (n = 3 average value).

(6) Compressive flexural modulus

The sample was cut into a size of 10 cm × 10 cm × sample thickness and allowed to stand for 24 hours under no load under an environment of 23 ° C. ± 2 ° C. After that, the sample was placed in an universal testing machine (Instron Japan Co., Ltd., A universal testing machine) and a pressure plate with a thickness of 3 mm were placed so that the center of the sample was the center of the sample, the compression of the center of the sample was started at a rate of 10 mm / min, and when a load of 0.3 N 0.05 N was detected by a universal testing machine The thickness was measured to obtain the thickness of the hardness meter. At this time, the pressure plate is compressed to 75% of the thickness of the hardness meter at a speed of 100 mm / min at a zero point, and the pressure plate is returned to the zero point at a speed of 100 mm / min. After a lapse of 4 minutes, the specimens were further compressed to 25% and 65% of the thickness of the hardness meter at a speed of 100 mm / min, and the load at that time was measured and the hardness was H ₂₅ and the hardness H ₆₅ was 65% : Unit N /? 50 (average value of n = 3). Using the hardness H ₂₅ at 25% compression and the hardness H ₆₅ at 65% compression thus obtained, the compression and flexural modulus was calculated from the following equation

(Compressive flexural modulus) = H ₆₅ / H ₂₅ : (average value of n = 3)

Lt; / RTI >

(7) Fiber diameter

The sample was cut into a size of 10 cm in the width direction × 10 cm × sample thickness in the longitudinal direction, and 10 linear bodies were randomly collected from the cut end face in the thickness direction to a length of about 5 mm. The collected fibers were measured for the thickness of the fibers viewed from the side of the fiber (side of the fiber) by focusing the optical microscope at a proper magnification to the fiber diameter measuring point (the point at which the fiber diameter was measured). Further, the surface of the network structure is flattened to obtain smoothness, so that the fiber cross-section (cross-section of the fiber) may be deformed. Therefore, no sample is taken from an area within 2 mm from the surface of the network structure (surface of the network structure).

(8) Thickness

Four samples were cut out in a size of 10 cm in width direction x 10 cm in length direction x sample thickness in width direction, and left for 24 hours without any load. Thereafter, a round specimen having an area of 15 cm < 2 > was used as a solid cross-section fiber face side (fiber face side of the solid cross section) The average value was determined to be the thickness.

(9) tan?

The sample was formed into a sheet sample having a thickness of 300 mu m by a heat press at a set temperature of 230 DEG C, and the sheet sample was cut into a length of 23 mm and a width of 5 mm. Using a dynamic viscoelasticity measuring device (Rheogel-E-4000 manufactured by UBM Co.), a 4 mm portion of both ends of each long side of the cut sheet sample was fixed with a tension jig and measured at 30 Hz and a heating rate of 2 캜 / (Ratio E "/ E 'of loss elastic modulus E" to storage elastic modulus E').

(10) Shore A hardness

The hardness was measured according to the measuring method of durometer A hardness specified in JIS K6253-3: 2012.

(Synthesis Example 1)

1800 g of cyclohexane, 30 g of styrene monomer and 0.32 g of n-butyl lithium were added to a 5-liter autoclave, and polymerization was carried out at 60 DEG C for 1 hour. Then, 162 g of isoprene monomer was added and polymerized at 60 DEG C for 1 hour. Finally, 30 g of styrene monomer was added and polymerization was carried out at 60 DEG C for 1 hour. An equivalent amount of methanol was added to this living polymer solution, and the mixture was deactivated and further precipitated in a large amount of methanol to recover polystyrene type thermoplastic elastomer (S-1) containing isoprene. The obtained isoprene-containing polystyrene-based thermoplastic elastomer (S-1) had a styrene content of 30% by mass and a weight average molecular weight of 170,000. Here, the "polystyrene-based thermoplastic elastomer (S-1) containing isoprene" means the first triblock copolymer.

(Synthesis Example 2)

1800 g of cyclohexane, 67.5 g of styrene monomer and 0.5 g of n-butyllithium were added to the 5-liter autoclave, and polymerization was carried out at 60 DEG C for 1 hour. Then, 315 g of 1.3-butadiene monomer was added and polymerization was carried out at 60 DEG C for 1 hour. Finally, 67.5 g of styrene monomer was added and polymerization was carried out at 60 캜 for 1 hour. An equivalent amount of methanol was added to the living polymer solution, the mixture was deactivated, and the polymer was further precipitated in a large amount of methanol, thereby recovering the polystyrene-based thermoplastic elastomer (S-2) containing butadiene. The content of styrene in the obtained polystyrene-based thermoplastic elastomer (S-2) containing butadiene was 30% by mass, and the weight average molecular weight was 270,000. Herein, "polystyrene-based thermoplastic elastomer (S-2) comprising butadiene" means a second triblock copolymer.

(Example 1)

The shape of the orifice on the effective surface of the nozzle having the length in the width direction of 100 cm and the length in the thickness direction of 62.4 mm was such that the solid orifices having the outer diameter of 0.5 mm were arranged in a zigzag arrangement with a pitch of 6 mm in the width direction holes and a pitch of 5.2 mm in the thickness direction Nozzles were used. That is, the shape of the effective surface of the nozzle was 100 cm in the width direction and 62.4 mm in the thickness direction. The orifice was a solid-forming orifice having an outer diameter of 0.5 mm, and the arrangement of the orifices was a zigzag arrangement in which the pitch between the holes in the width direction was 6 mm and the pitch between the holes in the thickness direction was 5.2 mm. , 21.3 mass% of a polystyrene-based thermoplastic elastomer (S-1) containing isoprene, 43.3 mass% of a polystyrene-based thermoplastic elastomer (S-2) containing butadiene, 20 mass% of a paraffinic process oil (weight average molecular weight: 750) 5% by mass of a hydrogenated terpene resin (softening point: 150 ° C), and 45 g / m 2 of polypropylene (tensile elastic modulus: 2000 MPa, MFR (melt mass flow rate) (measured at 230 ° C. in accordance with JIS K7210-1: 2014) 10 min) was weighed so as to be 10 mass%, and mixed well in a pellet state to use as a raw material. The mixture of the raw materials thus obtained was discharged in a molten state at a spinning temperature (melting temperature) of 200 DEG C and a single-ended discharge rate of 1.5 g / min down the nozzle. Here, the configuration below the nozzle was as follows. Cooling water was placed 21 cm below the nozzle surface. A stainless steel endless net having a length of 50 mm was disposed immediately below the nozzle between the nozzle and the cooling water. A pair of take-up conveyors I was putting out. Based on the above-described configuration, a three-dimensional network structure was formed while forming a loop by fusing the discharge line in the molten state to fuse contact portions. Both sides of the molten network thus obtained were inserted into the cooling water at a rate of 1.0 m per minute while being sandwiched between the draw conveyors and solidified to flatten both sides. Thereafter, it was cut into a predetermined size and subjected to an annealing treatment for 30 minutes by hot air at 70 占 폚 to obtain a network structure. For each of the obtained network structures, the respective physical properties were obtained in accordance with the above (1) to (10). The results are summarized in Table 1.

(Example 2)

Except that 50.0 mass% of polystyrene type thermoplastic elastomer (S-1) containing isoprene and 15.0 mass% of polystyrene type thermoplastic elastomer (S-2) containing butadiene were weighed, A reticular structure was obtained. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Example 3)

Except that 38.2% by mass of polystyrene type thermoplastic elastomer (S-1) containing isoprene and 26.0% by mass of polystyrene type thermoplastic elastomer (S-2) containing butadiene were metered in. A reticular structure was obtained. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Example 4)

Except that 21.7% by mass of polystyrene type thermoplastic elastomer (S-1) containing isoprene and 43.3% by mass of polystyrene type thermoplastic elastomer (S-2) containing butadiene were weighed in the same manner as in Example 1, A reticular structure was obtained. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 1)

A network was obtained in the same manner as in Example 1, except that the polystyrene-based thermoplastic elastomer (S-1) containing isoprene was weighed so as to be 100% by mass. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 2)

A network was obtained in the same manner as in Example 1 except that the polystyrene-based thermoplastic elastomer (S-2) containing butadiene was weighed to 100% by mass. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 3)

20% by mass of a polystyrene-based thermoplastic elastomer (S-2) containing butadiene, a soft polypropylene (hardness (measured at 23 캜 according to ASTM D2240): 61 A, MFR (melt mass flow rate) : 2014 measured at 190 캜): 17 g / 10 min) was measured to be 80% by mass, a network structure was obtained in the same manner as in Example 1. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 4)

, 65 mass% of a polystyrene type thermoplastic elastomer (S-1) containing isoprene, 20 mass% of a paraffinic process oil (weight average molecular weight: 750), 5 mass% of a hydrogenated terpene resin (softening point: 150 deg. The same procedure as in Example 1 was carried out except that propylene (tensile elastic modulus: 2000 MPa, MFR (melt mass flow rate) measured at 230 캜 according to JIS K7210-1: 2014: 45 g / 10 min) To obtain a network structure. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 5)

, 10 mass% of a paraffinic process oil (weight average molecular weight: 750), 5 mass% of a hydrogenated terpene resin (softening point: 150 占 폚), 75 mass% of a polystyrene type thermoplastic elastomer (S- The same procedure as in Example 1 was carried out except that propylene (tensile elastic modulus: 2000 MPa, MFR (melt mass flow rate) measured at 230 캜 according to JIS K7210-1: 2014: 45 g / 10 min) To obtain a network structure. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 6)

, 15% by mass of a polystyrene-based thermoplastic elastomer (S-2) containing butadiene, a soft polypropylene (hardness (measured at 23 캜 according to ASTM D2240): 61 A, MFR (melt mass flow rate) (Weight average molecular weight: 750) as measured at 190 deg. C in accordance with the method described in Production Example 1, 17 g / 10 min) and 80% by mass of paraffinic process oil (weight average molecular weight: 750) A reticular structure was obtained. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 7)

, 13.3% by mass of a polystyrene-based thermoplastic elastomer (S-2) containing butadiene, 10% by mass of a paraffinic process oil (weight-average molecular weight: 750) 5% by mass of a hydrogenated terpene resin (softening point: 150 ° C), and 45 g / m 2 of polypropylene (tensile elastic modulus: 2000 MPa, MFR (melt mass flow rate) (measured at 230 ° C. in accordance with JIS K7210-1: 2014) 10 min) was adjusted so as to be 5% by mass, a network structure was obtained in the same manner as in Example 1. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 8)

, 22.9 mass% of polystyrene type thermoplastic elastomer (S-1) containing isoprene, 57.1 mass% of polystyrene type thermoplastic elastomer (S-2) containing butadiene, 10 mass of paraffinic process oil (weight average molecular weight: 750) 5% by mass of a hydrogenated terpene resin (softening point: 150 ° C), and 45 g / m 2 of polypropylene (tensile elastic modulus: 2000 MPa, MFR (melt mass flow rate) (measured at 230 ° C. in accordance with JIS K7210-1: 2014) 10 min) was adjusted so as to be 5% by mass, a network structure was obtained in the same manner as in Example 1. With respect to the resultant network structure, the respective physical properties were obtained in the same manner as in Example 1. The results are summarized in Table 1.

The results are shown in Table 1. Referring to Table 1, it was confirmed that the reticulated structures of Examples 1 to 4 contained 45 mass% or more of polystyrene-based thermoplastic elastomer, styrene content was 5 mass% or more and 40 mass% And the ratio of the second triblock copolymer was in the range of 0.25 or more and 0.75 or less. By having such a constitution, the network structures of Examples 1 to 4 had low rebound characteristics because the hysteresis loss was 35% or more, tan? Was 0.3 or more, and Shore A hardness was 80 or less. In addition, since the reticulated structures of Examples 1 to 4 had excellent compression durability, compression flexural modulus of 10 or less, thickness of 5 mm or more, and Shore A hardness of 40 or more because the compressive residual strain at 40 캜 was 40% or less, There was no. Since the second tri-block copolymer is not contained in the reticulated structure of Comparative Example 1, it can not be said to be low resilience because the Shore A hardness is larger than 80, and the 40 ° C compression residual deformation is larger than 40 Durability was low. In the network structure of Comparative Example 2, since the first triblock copolymer is not included, the hysteresis loss is smaller than 35% and the tan delta is smaller than 0.3, There was a sense of bottom contact. Since the content of styrene was less than 5 mass% and the first triblock copolymer was not contained in the reticulated structure of Comparative Example 3, tan? Was smaller than 0.3 and Shore A hardness was larger than 80, , But the durability was deteriorated because the 40 ° C compression residual strain was larger than 40.

It should be understood that the embodiments and examples disclosed herein are by way of illustration and not of limitation in all respects. It is intended that the scope of the invention be indicated by the appended claims rather than the foregoing description and that all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims (10)

A network structure having a three-dimensional random loop junction structure composed of a continuous linear body,
The continuous strand is a fiber made of a resin containing a polystyrene type thermoplastic elastomer as a main component of at least 45 mass%
The polystyrene-based thermoplastic elastomer includes a first triblock copolymer composed of a styrene polymer block-isoprene polymer block-styrene polymer block, a styrene polymer block-butadiene polymer block-styrene polymer block, and a styrene polymer block-butadiene and isoprene And a second triblock copolymer composed of at least one of a cohesive block-styrene polymer block. The network structure according to claim 1, wherein the styrene content is 5 mass% or more and 45 mass% or less. 3. The network 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. 4. The network according to any one of claims 1 to 3, wherein the 40 DEG C compression residual strain is 40% or less. The network according to any one of claims 1 to 4, wherein the hysteresis loss by compression is 35% or more. 6. The network structure according to any one of claims 1 to 5, wherein the compressive flexural modulus is 10 or less. 7. The network structure according to any one of claims 1 to 6, wherein the continuous filament has a fiber diameter of 0.1 mm or more and 3.0 mm or less, and the thickness of the network structure is 5 mm or more and 300 mm or less. 8. The network structure according to any one of claims 1 to 7, wherein the resin has a tan? Of at least 0.3 measured at 25 占 폚 using a dynamic viscoelasticity measuring apparatus. 9. The network according to any one of claims 1 to 8, wherein the resin has a Shore A hardness of 40 or more. 10. The network structure according to any one of claims 1 to 9, wherein the use of the network structure is a cushioning material, a shock absorber, or a cushioning material.

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