JP3344512B2 - Heterogeneous net structure and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a futon, a furniture, a bed,
The present invention relates to a network structure of different fineness having excellent cushioning properties and heat resistance and durability suitable for a cushion material for a vehicle, a heat insulating material, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art At present, urethane foam, non-elastic crimped fiber-filled cotton, and resin cotton and hard cotton to which non-elastic crimped fibers are bonded are used as cushioning materials for futons, furniture, beds, trains, automobiles, and the like. Have been.

[0003] However, foamed-crosslinked urethane has good durability as a cushioning material, but is inferior in moisture permeation and water permeability and has heat storage properties, so that it is easy to humid. In addition, the damage to the incinerator is large, and the cost for removing toxic gas is high.
For this reason, landfills have been increased, but there is a problem in that it is difficult to stabilize the ground, so that landfill locations are limited and costs increase. Further, although the processability is excellent, there is a problem of pollution of chemicals used during the production. In addition, in the case of the cotton filled with thermoplastic polyester fiber, since the space between the fibers is not fixed, the shape at the time of use collapses, the fiber moves, and the crimp set causes a decrease in bulkiness and a decrease in elasticity. become.

Japanese Patent Application Laid-Open Publication No. Sho 6 (1994) discloses a resin cotton in which polyester fibers are bonded with an adhesive, for example, a rubber using an adhesive as a rubber.
Nos. 0-11352, JP-A-61-141388 and JP-A-61-141391. Further, JP-A-61-1377 discloses a method using a crosslinkable urethane.
No. 32 publication. These cushioning materials are inferior in durability, are not thermoplastic, cannot be recycled because they are not a single composition, and have problems such as complicated workability and pollution of chemicals used during production. .

[0005] Polyester hard cotton, for example, JP-A-58-3
JP-A No. 1150, JP-A-2-154050, JP-A-3-220354, etc., are disclosed in Japanese Patent Application Laid-Open No. Sho 58-58, because the adhesive component of the heat-bonding fiber used is a brittle amorphous polymer. -136828, JP-A-3-
There is a problem that the adhesive portion is brittle and the durability is poor such that the adhesive portion is easily broken during use and the form and elasticity are reduced. As an improved method, a method of performing confounding treatment has been proposed in Japanese Patent Application Laid-Open No. 4-245965, but there is a problem that the brittleness of the bonded portion is not solved and the elasticity is greatly reduced. In addition, there is also complexity in processing. Further, there is a problem that the bonded portion is hardly deformed and it is difficult to provide soft cushioning. For this reason, the adhesive is soft and the polyester elastomer recovers even if deformed to some extent.
Japanese Patent Application Laid-Open No. 4-240219 discloses a thermal bonding fiber using an inelastic polyester as a core component, and WO-91 / 19032, Japanese Patent Application Laid-Open No. 5-156561 discloses a cushioning material using the fiber. It has been proposed in, for example, JP-A-5-163654. When the adhesive component used in this fiber structure is a soft segment of polyester elastomer, the content of polyalkylene glycol is 30 to 50.
5% by weight of terephthalic acid in the acid component of the hard segment
It contains 0 to 80 mol%, and contains isophthalic acid as another acid component composition to increase the amorphousness, and has a melting point of 180%.
℃ or lower and low melt viscosity to improve the formation of the heat-bonded part to form an amoeboid bonded part, but plastic deformation is easy, and the core component is inelastic polyester, so plastic deformation especially under heating And there is a problem that heat resistance and compression resistance decrease. In addition, this fiber is the Japanese Patent Publication No. 60-1
Since the fibers are considered to be the same as those described in Japanese Patent No. 404, it cannot be said that the prior art is improved.

A thermoplastic olefin network used for civil engineering is disclosed in JP-A-47-44839. However, unlike a cushion made of fine fibers, the surface is uneven and the touch is poor, and since the material is an olefin, the heat resistance and durability are extremely poor and cannot be used as a cushion material. In Japanese Patent Publication No. 3-17666, there is a method in which discharge filaments having different fineness are fused to each other to form a molding, but this is a net-like structure not suitable for a cushion material. Japanese Patent Publication No. 3-55583 discloses a method in which only a very small surface is thinned by a thinning device such as a rotating body before cooling. In this method, the surface cannot be flattened, and a thick and thin linear layer cannot be formed. Therefore, the cushioning material does not provide a comfortable sitting comfort. JP-A-1-207
Japanese Patent Publication No. 462 discloses a floor mat made of vinyl chloride, which is not preferable as a cushioning material because of its poor compression recovery at room temperature and extremely poor heat resistance.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems,
An object of the present invention is to provide a network structure having a different fineness and a manufacturing method suitable for a cushion material having excellent heat resistance and cushioning properties and excellent in heat resistance.

[0008]

Means for solving the above problems, ie, the present invention is directed to a heterogeneous net structure having at least two or more net structures having different finenesses integrated and having a surface layer and a basic layer. a body, before Symbol surface layer and the base layer of the form a plurality of loops so Magarikunera a continuous filament comprising a thermoplastic elastic resin, and contacted the respective loops in each other molten state, the contact portion large of moiety is fused, is a three-dimensional random loop structure of a multilayer that shape retaining a constant width and thickness, thick when the difference between the fineness of the previous SL surface layer and the base layer of in terms of Mardan area The second moment of area (Ib) of the fine filaments and the second moment of area (Ib) of the fine filaments
s) and a plurality of nozzle orifices characterized by being combined so as to have a ratio (Ib / Is) of 2 or more and being integrated, and a number of nozzle orifices are arranged. From the nozzle having two or more arrangements in which the ratio (Sb / Ss) of the maximum cross-sectional area (Sb) to the minimum cross-sectional area (Ss) in terms of the circular cross-sectional area differs by 1.5 or more, 1
While discharging the thermoplastic elastic resin in a molten state downward at a high temperature of 0 to 80 ° C., and forming a multilayer three-dimensional random loop structure having a fixed width and thickness by fusing,
By sandwiching with a take-off device and continuing to cool, a heterogeneous fineness network having a multi-layered surface layer having a different fineness and a basic layer is formed in a single step. is there.

The thermoplastic elastic resin in the present invention is obtained by block copolymerizing a soft segment such as a polyether-based glycol, a polyester-based glycol, and a polycarbonate-based glycol having a molecular weight of 300 to 5,000. Polyester-based elastomer, polyamide-based elastomer,
Polyurethane-based elastomers and the like can be mentioned. By using a thermoplastic elastic resin, regeneration becomes possible by re-melting, so that recycling becomes easy. For example, as a polyester-based elastomer, a polyester ether block copolymer having a thermoplastic polyester as a hard segment and a polyalkylenediol as a soft segment, or a polyester ester having an aliphatic polyester as a soft segment A block copolymer can be exemplified. More specific examples of polyester ether block copolymers include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene 2.6 dicarboxylic acid, naphthalene 2.7 dicarboxylic acid, and diphenyl 4.4 4 'dicarboxylic acid. Alicyclic dicarboxylic acids such as 1.4 cyclohexanedicarboxylic acid, aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid dimer acid, and at least one dicarboxylic acid selected from ester-forming derivatives thereof; Seeds, 1,4-butanediol, ethylene glyco-
, Trimethylene glycol, tetramethylene glycol
Alicyclic diols such as aliphatic diols such as toluene, pentamethylene glycol and hexamethylene glycol, 1.1 cyclohexane dimethanol, 1.4 cyclohexane dimethanol, and the like; At least one diol component selected from ester-forming derivatives and the like; and polyethylene glycol having an average molecular weight of about 300 to 5,000.
A triblock copolymer composed of at least one of polyalkylenediols such as ethylene glycol, polypropylene glycol, polytetramethylene glycol, and ethylene oxide-propylene oxide copolymer. The polyester ester block copolymer is a ternary block copolymer composed of at least one of each of the above dicarboxylic acids, diols, and polyester diols such as polylactone having an average molecular weight of about 300 to 5,000. .
In consideration of thermal adhesion, hydrolysis resistance, stretchability, heat resistance, etc., terephthalic acid or naphthalene 2.6 dicarboxylic acid as a dicarboxylic acid, 1.4 butanediol as a diol component, poly As the alkylenediol, a triblock copolymer of polytetramethylene glycol or a terpolymer of polyester is particularly preferable. In a special case,
Those having a polysiloxane-based soft segment introduced can also be used. The thermoplastic elastomer resin of the present invention also includes those obtained by blending a non-elastomer component with the above-mentioned elastomer and copolymerizing the same. In addition, the melting point of the thermoplastic elastic resin of the present invention is 1 such that heat resistance and durability can be maintained.
A temperature of 40 ° C. or higher is preferable, and a temperature of 160 ° C. or higher is more preferable because the heat resistance and durability are improved. In addition, durability can be improved by adding an antioxidant, a light-proofing agent, or the like, if necessary.

[0010] The filaments constituting the network structure of the present invention preferably have an endothermic peak below the melting point in the melting curve measured by a differential scanning calorimeter. Those having an endothermic peak below the melting point have remarkably improved heat resistance and sag resistance than those having no endothermic peak. For example, preferred polyester elastomers of the present invention include those containing 90 mol% or more of terephthalic acid or naphthalene 2.6 dicarboxylic acid as an acid component, more preferably the content of terephthalic acid or naphthalene 2.6 dicarboxylic acid is After transesterification of the glycol component with 95 mol% or more, particularly preferably 100 mol%, polymerization is carried out to a required degree of polymerization, and then, as polyalkylenediol, the average molecular weight is preferably 500 or more and 5000 or less, particularly preferably. Is 100
When polytetramethylene glycol of 0 to 3000 is copolymerized in an amount of 15 to 70% by weight, more preferably 30 to 60% by weight, the content of terephthalic acid or naphthalene 2.6 dicarboxylic acid is increased. If the amount is large, the crystallinity of the hard segment is improved, plastic deformation is difficult, and the heat resistance and sag resistance are improved. However, after the heat bonding, annealing treatment is performed at a temperature at least 10 ° C. lower than the melting point. Then, the heat resistance and sag resistance are further improved. Annealing after imparting compressive strain further improves heat resistance and sag resistance. When a melting curve of a line of the network structure thus treated is measured by a differential scanning calorimeter (DSC), an endothermic peak is more clearly exhibited at a temperature from room temperature to a melting point. When annealing is not performed, an endothermic peak does not appear below the melting point. By analogy with this, it is considered that the annealing may cause rearrangement of the hard segments, form pseudo-crystallization-like cross-linking points, and improve heat resistance and sag resistance. (This process is defined as pseudo-crystallization process)

[0011] The reticulated structure of the present invention is characterized in that a wire made of a thermoplastic elastic resin is meandered, and the wires are brought into contact with each other;
The contact portions are fused to form a three-dimensional network structure. As a result, even if a large deformation is given by a very large stress, the entire fusion-integrated three-dimensional network structure is deformed to absorb the stress, and when the stress is released, the rubber elasticity of the elastic resin is developed. Thus, the structure can be restored to its original form. In a cushioning material containing a filament made of a known inelastic resin,
Since plastic deformation occurs and such recovery does not occur, heat resistance and durability are inferior. If not fused, the shape cannot be maintained, and the structure does not deform integrally, so that fatigue phenomena occur due to stress concentration and the durability is deteriorated, and the shape is undesirably deformed. A more preferable degree of fusion in the present invention is a state in which most of the portions in contact with the filaments are fused, and most preferably a state in which all the contact portions are fused.

The filaments forming the reticulated structure made of the thermoplastic elastic resin of the present invention are three-dimensional reticulated structures in which at least a plurality of layers composed of reticulated filaments are integrated. When used as a cushioning material, the function of the cushion layer is to increase the basic fineness and make it slightly harder, and to absorb vibration and maintain body shape (abbreviated as a basic layer), and to make the fineness thinner and increase the number of constituent lines As a soft layer, a layer (which is abbreviated as a surface layer) that gives a comfortable touch to the buttocks by moderate sinking and moderately distributes the pressure distribution of the buttocks is integrated, deforming and absorbing stress and vibration as one It is necessary to improve sitting comfort. Further, since the surface layer composed of a plurality of layers and the basic layer are fused and integrated, the entire structure can be deformed by an external force, thereby preventing a decrease in sag resistance and heat resistance durability. If the surface layer and the base layer are not melt-bonded, it is not preferable because the surface layer is easily removed selectively. Since the surface layer and the basic layer are not a single layer but a multilayer, fine control of cushioning property and uniform dispersion of compressive stress can be easily performed. The preferred fineness difference between the filaments of the surface layer and the basic layer according to the present invention is the maximum cross-sectional secondary moment (Ib) of the basic layer in terms of the circular cross-sectional area / the minimum cross-section of the surface layer.
Next moment (Is): (Ib / Is) is 2.0 or more, more preferably 4 or more. If the ratio is less than 2.0, the above-mentioned effect is insufficiently exhibited. In order to provide another preferable function, an optimum combination of the fineness and density of each layer can be arbitrarily selected in consideration of the apparent density.
In addition, although the average linear thickness of the whole reticulated body is not particularly limited, a preferable average thickness is 0.01 to 10 mm, and more preferably 0.1 to 5 mm. In the present invention, the secondary moment of area when converted to a round cross section is obtained by calculating the diameter (d) of the round cross section and using the following equation. Round cross section of the second moment (I) = πd ^4/64

[0013] The cross-sectional shape of the filaments constituting the net-like structure of the present invention is not particularly limited. However, by forming a hollow cross-section or a modified cross-section, it is possible to impart anti-compressive properties and bulkiness, thereby reducing the fineness. Particularly preferred in the present invention having a surface layer portion. The anti-compression property is adjusted by the modulus of the material used, and the gradient of the initial compressive stress can be adjusted by increasing the hollow ratio and irregularity for soft materials, and the hollow ratio and irregularity can be decreased for materials with slightly higher modulus. It provides good compression resistance with good sitting comfort. As another effect of the hollow cross section and the irregular cross section, by increasing the hollow ratio and the degree of irregularity, when the same compression resistance is imparted, the weight can be further reduced, and when used for a seat of an automobile or the like, energy saving can be achieved. In the case of a futon, the handling at the time of raising and lowering is improved.

[0014] The apparent density of the average of the present invention the network structure is particularly, but not limited to, susceptible 0.005 g / cm ³ or more 0.20 g / cm ³ or less is preferable that the function is expressed as a cushion body, and more preferably 0 .01g / cm ³ or more 0.10g / cm ³ is less than or equal to. The thickness of the mesh is
Although not particularly limited, it is preferably 3 mm or more in which the function as a cushion body is easily exhibited. The size of the random loop can be arbitrarily selected depending on the intended use, but the diameter is preferably 1 to 50 mm, particularly preferably 2 to 15 mm. Thus, since the reticulated structure of the present invention has at least two or more layers composed of a plurality of filaments having different finenesses integrated,
The preferred density can be changed by changing the apparent density of each layer composed of filaments having different fineness. For example, in the case of a surface layer with a fine size and a basic layer with a fine size, the density of the surface layer is slightly increased to increase the number of components, reduce the stress applied to one filament, and improve the dispersion of stress. Also, by improving the cushioning property for supporting the buttocks, the sitting comfort can be improved. The surface of the base layer that is in contact with the seat frame is made of a finer layer. The entire structure integrated with the cushion layer can be deformed so as to be able to be transformed into energy, thereby improving the sitting comfort and improving the durability of the cushion. In addition, in order to increase the thickness and the tension of the side of the seat, the fineness can be made slightly thinner partially to increase the density. Thus, for each layer composed of the filaments having different finenesses, a preferred density and fineness can be arbitrarily selected according to the purpose. In addition, the thickness of each layer of the network structure is not particularly limited, but is preferably 3 mm or more in which the function as the cushion body is easily exhibited.

The windings of the thermoplastic elastic resin on the surface of the network structure form a loop, and in the middle of the loop, the thickness direction of the network structure is set as a base line, and 4% from the base line.
It is preferable in the present invention to have a surface layer portion with a reduced fineness that it is bent by 5 ° or more, the surface is substantially flattened, and most of the contact portions are fused. As a result, the contact points of the filaments on the surface of the net-like structure are greatly increased to form an adhesion point, so that a local external force is received by the structural surface, and the surface structure is entirely deformed and the entire internal structure is When the stress is released by deformation, the elasticity of the elastic resin is developed and the structure can be restored to the original form. When the surface is not substantially flattened, when a local external force is applied to the surface, a stress concentration may be selectively generated up to the streaks and the bonding points on the surface. In some cases, fatigue due to stress concentration occurs and sag resistance decreases. When the filaments are made of a thermoplastic elastic resin, stress concentration is relieved because the entire structure is deformed in the three-dimensional structure portion. It does not recover.

Next, the production method of the present invention will be described. The reticulated structure of the present invention is obtained by using a general melt extruder, from a nozzle orifice having at least a plurality of rows having different cross-sectional areas of orifices in a row section in the longitudinal direction, at a temperature of 10 ° C. or higher and 80 ° C. or lower than the melting point. For example, in the molten state
A thermoplastic elastic resin obtained by a publicly known method such as 120620 is discharged downward, the discharge lines in a molten state are meandered and brought into contact with each other, and most of the contact portions are fused to form a three-dimensional structure. While forming the, sandwiched by the take-off device,
Then, the reticulated structure is cooled in a cooling bath to form a network of different fineness in which multiple layers of the network having different finenesses of the discharge filaments are integrated at the same time. When the pressure loss difference at the time of discharge is given by changing the cross-sectional area of the orifice,
The discharge amount at which the molten thermoplastic elastic resin is extruded from the same nozzle at a constant pressure decreases as the orifice has a larger pressure loss. In the present invention, a net-like structure made of different fineness filaments is manufactured using this principle. In the present invention, the nozzle having at least a plurality of rows having different cross-sectional areas of the orifices in the longitudinal section is, for example, an effective width 5 in the longitudinal direction.
0mm, the pitch between holes in the row in the width direction of the nozzle is 10mm constant,
In the case of an orifice shape having a round cross section in which the pitch between rows is constant at 5 mm, the orifice diameter is φ0.5 mm and 6 between rows 1 to 6.
By changing the method of configuring φ0.45 mm between rows 9 and φ0.3 mm between rows 9 and 11, and changing the orifice diameter in the width direction of the rows of the nozzles, for example, a 500 mm wide nozzle , The 9th and 10th rows are 10 holes on both sides in the width direction.
The method of configuring the middle 30 holes as φ 0.3 mm as 0.4 mm, changing the cross-sectional area of the orifice, changing the pitch between rows or the pitch between holes, and the pitch between both rows and holes Can be exemplified. Although the orifice shape of such a nozzle may have a round cross section, in the present invention,
By forming a hollow or irregular cross section of the wire, the three-dimensional structure formed by the discharge wire in the molten state makes it difficult for the flow to relax, and conversely, the flow time at the contact point can be maintained longer and the bonding point can be strengthened. Particularly preferred. In the case of heating for bonding described in Japanese Patent Application Laid-Open No. 1-2075, it is not preferable because the three-dimensional structure is easily relaxed, and it becomes difficult to form a three-dimensional structure. Next, the both sides of the molten three-dimensional structure are sandwiched by the take-off net, and the melted and twisted discharge lines on both sides are bent and deformed by 45 ° or more to flatten the surface and at the same time the discharge lines that are not bent. After the structure is formed by bonding the contact points with water, it is quenched continuously with a cooling medium (usually, it is preferable to use water at room temperature because the cooling rate can be increased and the cost is reduced). Obtain a three-dimensional three-dimensional network structure. Then, drying with water is performed. However, if a surfactant or the like is added to the cooling medium, draining or drying becomes difficult, and the thermoplastic elastic resin may swell, which is not preferable. As a preferred method of the present invention,
After cooling once, a pseudo-crystallization treatment is performed. The pseudo-crystallization temperature is at least 10 ° C. lower than the melting point (Tm).
This is performed at an α dispersion rising temperature (Tαcr) of anδ or higher. This treatment has an endothermic peak below the melting point, and significantly improves heat resistance and sag resistance as compared with those without the pseudo-crystallization treatment (without the endothermic peak). The preferred pseudo crystallization treatment temperature of the present invention is (Tαcr + 10 ° C.) to (Tm−
20 ° C). Pseudo crystallization by simple heat treatment improves heat set resistance. After cooling once,
Annealing by imparting a compression deformation of 0% or more is more preferable because heat set resistance is remarkably improved. In the case where a drying step is performed after cooling once, the pseudo crystallization treatment can be performed at the same time by setting the drying temperature to the annealing temperature. Further, a pseudo crystallization treatment can be separately performed. Next, it is cut into a desired length or shape and used as a cushion material. The desired loop diameter and wire diameter can be determined by the distance between the nozzle surface and a take-off conveyor provided on a cooling medium for solidifying the resin, the melt viscosity of the resin, the hole diameter of the orifice, and the discharge amount. A pair of take-up conveyors with adjustable intervals installed on the cooling medium sandwich and hold the discharge line in the molten state to fuse the parts that are in contact with each other, and are continuously drawn into the cooling medium to be solidified. When the body is formed, by adjusting the distance between the conveyors, the thickness can be adjusted while the fused net is in a molten state, and a desired thickness can be obtained. The distance between the take-up conveyor and the nozzle surface is preferably within 30 cm. If the distance is too long, the molten wire is cooled and the contact portion is not fused, which is not preferable. If the conveyor speed is too high, the contact point may be insufficiently formed, or the contact point may be cooled until the fusion point is sufficiently formed, and the fusion of the contact portion may be insufficient. On the other hand, if the speed is too slow, the melt will stay too much and the density will increase, so it is necessary to set a conveyor speed suitable for the desired apparent density.

When the net-like structure of the present invention is used for a cushion material, a resin to be used depending on the purpose of use and the site of use,
It is necessary to select fineness, loop diameter and bulk density. For example, when used for wading of the surface layer, it is preferable to use a low-density and fine fineness and a small loop diameter in order to provide a soft touch and a moderate sinking and a firm bulge. In order to lower the resonance frequency, linearly change the appropriate hardness and the hysteresis at the time of compression to improve the shape retention, and maintain the durability, medium density, thick fineness, and a slightly larger The tap diameter is preferred. In addition, it can be used by shaping it into a shape suitable for the purpose of use using a mold or the like to the extent that the three-dimensional structure is not impaired. Also, at any stage during the processing from the manufacturing process to the molded body in a range that does not reduce the performance other than the resin manufacturing process, functions such as flame retardancy, insect repellent antibacterial, heat resistance, water and oil repellency, coloring, fragrance etc. Processing such as drug addition can be performed.

[0018]

The present invention will be described in detail with reference to the following examples.

The evaluation in the examples was performed by the following method. Endothermic peak at melting point (Tm) and below melting point. . The endothermic peak (melting peak) temperature was determined from an endothermic curve measured at a heating rate of 20 ° C./min using a TA50, DSC50 type differential thermal analyzer manufactured by Shimadzu Corporation. Tαcr. . The polymer is heated to the melting point + 10 ° C and the thickness is about 300 µm
And a Tan δ (imaginary modulus M ”and a real part M ′ of modulus measured at 110 Hz and a heating rate of 1 ° C./min using a Vibron DDVII model manufactured by Orientec Co., Ltd.
The rise temperature of the α-dispersion corresponding to the transition temperature from the rubber elastic region to the melting region at a ratio of M ″ / M ′) Apparent density: The sample was cut into a size of 15 cm × 15 cm and cut into four portions. The height is measured, the volume is determined, and the weight of the sample is expressed as a value obtained by reducing the volume (average value of n = 4) Fineness difference of the filaments. A cross-section is cut out to obtain a cross-section photograph, and a cross-section photograph (Si) of each part is obtained from a cross-section photograph of each part having different fineness. From the obtained diameter , the secondary cross section of the circular cross section is obtained.
Using moments (I) = πd ^4/64 official, cross 2 Tsugimo - Instrument (Ii, Ij, ...) to seek, each portion of the cross section 2 Tsugimo - shown as placement ratio (n = 5 Average) .
Note that the maximum fineness difference (Ib / Is) is determined by the following equation: the maximum section secondary moment (Ib) in the basic layer / the minimum section secondary moment (Is) in the surface layer = Expressed as (Ib / Is). Fusion. . Whether or not the sample is fused is determined by visually judging whether or not the bonded fibers are separated by pulling the fibers by hand. Heat resistance (70 ° C residual strain). . The sample was cut into a size of 15 cm × 15 cm, compressed by 50%, allowed to stand in a dry heat at 70 ° C. for 22 hours, cooled to remove the compression strain, and the ratio of the thickness after standing for one day to the thickness before the treatment was indicated by%. (N
= Average value of 3) Repeated compression strain. . The sample was cut into a size of 15 cm × 15 cm, and 50% in a room at 25 ° C. and 65% RH by using a servo pulsar manufactured by Shimadzu Corporation.
The compression recovery is repeated at a cycle of 1 Hz until the thickness of the sample reaches 20,000 times.
Indicated by (Average value of n = 3) Sit comfort. . 30 ° C RH 75% indoor bucket frame for seat frame
A paneler sits on a seat in which a side of polyester moquette is hung on a cushion shaped like a letter (n = 5). (1) Feeling of flooring: The degree of "Donsu" when sitting and hitting the floor. Was qualitatively evaluated sensoryly. Not felt; ◎, almost felt; ○, slightly felt; △, felt; × (2) Feeling of stuffiness: After sitting for two hours, sensationally felt that the part in contact with the buttocks and the inner part of the crotch was stuffy. It was qualitatively evaluated. Almost no: ◎, slight stuffiness; ○, slight stuffiness; △, noticeable stuffiness; × (3) How long to be patient in 8 hours or less: 1 hour; × within 2 hours; △ within 4 hours;
○: 4 hours or more; ◎ (4) The degree of waist fatigue when seated in a seat for 4 hours was qualitatively evaluated sensoryly. None; ◎, hardly tired; ○, slightly tired; △, very tired; × (5) Overall evaluation: 4 points of ◎ from (1) to (4), ○
Is 3 points, Δ is 2 points, and × is 1 point, 12 points or more do not contain Δ; very good (◎), 12 points or more include Δ; good (○), 10 points or more are × Was evaluated as poor (x), poor x (x), and poor (x).

Examples 1-4 As a polyester elastomer, dimethyl terephthalate (DMT) or dimethyl naphthalate (DM
N) and 1.4 butanediol (1.4 BD) were charged with a small amount of a catalyst, transesterified by a conventional method, and polytetramethylene glycol (PTMG) was added. Table 1 shows the formulation of the thermoplastic elastomer resin raw material obtained by forming a terester block copolymer elastomer, adding 1% of an antioxidant, mixing and kneading, pelletizing, and vacuum drying at 50 ° C. for 48 hours. .

[0021]

[Table 1]

As the polyurethane elastomer, 4 ·
4 'diphenylmethane diisocyanate (MDI) and P
TMG and 1.4 BD as a chain extender were added, polymerized, pelletized and vacuum-dried to obtain a polyether-based urethane as a thermoplastic elastic resin raw material. The melting point of the obtained polymer is 152 ° C., the content of PTMG is 64%, and Tαcr is −10 ° C.
Met. (Experiment No. A-4)

The obtained thermoplastic elastic resin raw material has a melting point of +3.
At a temperature of 0 ° C to 50 ° C, the pitch between rows is 5mm in the length direction on the nozzle effective surface of 50cm in width and 5cm in length, the pitch between holes in the 1st to 8th rows is 10mm, and the orifice diameter is 1.0mm From the ninth to eleventh rows, a nozzle having a hole pitch of 2.5 mm and an orifice diameter of 0.7 mm was discharged at a total discharge rate of 1100 g / min, and cooling water was distributed 12 cm below the nozzle surface. Then, a pair of take-up conveyors arranged in parallel with a stainless steel endless net having a width of 60 cm at intervals of 5 cm so as to protrude partially above the water surface are taken out, and while the contact portions are fused, the both sides are sandwiched and sandwiched every minute. It is drawn into a cooling water at 25 ° C at a speed of 1m, solidified, and then subjected to a pseudo-crystallization treatment in a hot-air dryer at 100 ° C for 20 minutes or air-dried without the pseudo-crystallization treatment and cut into a predetermined size. Average apparent density 0.043-0.044 g / A net structure of cm ³ was obtained.
Table 2 shows the characteristics of the obtained network structure.

[0024]

[Table 2]

Comparative Examples 1-2 Polyethylene terephthalate having an intrinsic viscosity of 0.63 (PE
T) and polypropylene having a melt index of 35 (P
P) except that the extrusion temperatures were 280 ° C. and 250 ° C.
Table 2 shows the characteristics of the network structure obtained under the same conditions as in Example 1.

Comparative Example 3 Example 2 was repeated except that the take-up conveyor net was arranged 60 cm below the nozzle surface and the pseudo-crystallization treatment was not performed after the take-up conveyor net.
Table 2 shows some of the properties of the network structure obtained in the same manner as in Example 1. In addition, since the adhesion state is poor and the shape retention is poor, the evaluation of the apparent density, the residual strain at 70 ° C., and the repeated compression strain is not performed.

COMPARATIVE EXAMPLE 4 Nozzle hole arrangement was 5 mm between rows and 10 mm between holes
From the nozzle with an orifice diameter of φ1.0 mm, the total discharge amount of the elastomer of Experiment No. 2 was set to 235 ° C. at 235 ° C.
Table 2 shows the results of a comparison of the riding comfort of the network structure obtained under the same conditions as in Example 2 except that the discharge was performed at 0 g / min and the pseudo crystallization treatment was not performed.

Embodiment 5 The orifice shape of the nozzle is set to 0.
Table 2 shows the characteristics of the reticulated structure obtained under the same conditions as in Example 4, except that the Y-shaped cross section was 4 mm wide.

Example 1 is a net-like structure suitable for a cushioning material which is soft and moderately sinks and has good heat resistance and durability. Examples 2 and 3 are slightly hard and have a good shape retention.
This is an example of a network structure most suitable for a cushioning material having good heat resistance and durability. Example 4 is an example in which a pseudo-crystallization treatment using a slightly soft polyurethane polymer is not performed, and since the softness is a little soft, there is a sink in the buttocks but the sitting comfort is good. The fifth embodiment is an example in which the softness of the fourth embodiment is changed to a triangular cross section to improve the sitting comfort. Comparative Example 1
And Comparative Example 2 is an example using a thermoplastic inelastic resin, does not have an endothermic peak below the melting point even after pseudo-crystallization treatment,
This is an example in which heat resistance and durability are remarkably inferior and hard and the sitting comfort is extremely poor, which is not suitable for a cushion material. Comparative Example 3 is an example in which fibers are not fused to each other, and has extremely poor shape retention and is not suitable for a cushion material. This is an example in which the apparent bulk density is low, and is not suitable for a cushioning material having a remarkable floor feeling due to a low repulsive stress at the time of compression and having poor sitting comfort. Comparative Example 4 is an example out of the range of the present invention in which the fineness is not changed, and the sitting comfort is inferior to that of Example 2.

[0030]

The reticulated structure of the present invention is a reticulated reticulated body made of a thermoplastic elastic resin, in which a plurality of layers having different finenesses are fused and integrated to further improve the sitting comfort, heat resistance and durability. Since it is a bulky, moderately compressive repulsive, and easily recyclable net-like structure suitable for a cushion material that is resistant to stuffiness, it is useful for vehicle seats, marine seats, furniture cushions, and bedding products. It can be used alone or in combination with other materials. Furthermore, it can be used in various applications for elastic nonwoven fabric applications.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-92214 (JP, A) JP-A-5-138789 (JP, A) JP-A-5-272043 (JP, A) JP-A-58-1982 109670 (JP, A) Japanese Utility Model 2-18371 (JP, U) Japanese Utility Model 2-18300 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) D04H 1/00-18 / 00 B68G 1/00-15/00 B32B 1/00-35/00

Claims (4)

(57) [Claims] 1. A least two different network structure fineness are integrated, a different fineness network structure having a surface layer and a base layer, before Symbol surface layer and the base layer of a thermoplastic elastomeric resin A continuous multifilament is formed by winding a large number of loops, and the respective loops are brought into contact with each other in a molten state . three-dimensional random is a loop structure, before <br/> Symbol of the surface layer and the difference in fineness of the base layer is thick fineness when converted into Mardan area striatum second moment (Ib)
Characterized by being combined so as to have a ratio (Ib / Is) of 2 or more to the second moment of area (Is) of a filament having a fine fineness, and integrated to form a net. 2. A loop forming a network structure is pushed and bent at least 45 ° from the base line in the middle of the loop with the thickness direction of the network structure as a base line, and most of the contact portions are fused. 2. The heterogeneous reticulated structure according to claim 1, wherein the structure is substantially flattened. 3. A large number of nozzle orifices are arranged, and the cross-sectional area of the orifice is the ratio (Sb / Sb) between the maximum cross-sectional area (Sb) and the minimum cross-sectional area (Ss) in terms of a circular cross-sectional area.
s) From a nozzle having two or more arrangements different from each other by 1.5 or more, a thermoplastic elastic resin in a molten state is discharged downward at a temperature 10 to 80 ° C. higher than the melting point, and is fused to have a certain width. While forming a multilayered three-dimensional random loop structure with a preserving thickness, it is sandwiched by a take-off device and cooled continuously, so that it can be used as a surface layer with multiple layers and different fineness.
Preparation of different fineness network structure and forming a different fineness network structure having a layer in one step. 4. Once cooled, at least 10 ° C. below the melting point
Preparation of different fineness network structure according to claim 3 you and performing ring - annealing at a temperature lower than.