JP3430442B2 - Reticulated structure and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a futon, furniture, bed,
The present invention relates to a net-like structural body having excellent cushioning properties and heat resistance, which is suitable for a vehicle cushioning material, a heat insulating material, and the like, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Currently, as cushion materials for futons, furniture, beds, trains, automobiles, etc., urethane foam, non-elastic crimp fiber stuffed cotton, and resin cotton or hard cotton to which non-elastic crimp fiber is adhered are used. Has been done.

However, although the foamed-crosslinked urethane has good durability as a cushioning material, it is apt to be stuffy due to its poor moisture permeability and heat storage and has a heat storage property, and it is difficult to recycle because it is not thermoplastic, and is burned. The damage to the incinerator is large and the cost for removing toxic gas is high.
For this reason, landfilling has become more frequent, but it is difficult to stabilize the ground, and there is a problem that landfilling sites are limited and costs increase. Further, although it has excellent processability, it also has a problem of pollution of chemicals used during manufacturing. In addition, since the fibers are not fixed in the thermoplastic polyester fiber wadding, the form may collapse during use, the fibers may move, and the crimp may cause a decrease in bulkiness and elasticity. become.

As a resin cotton in which polyester fibers are adhered with an adhesive, for example, a rubber-based adhesive is used, Japanese Patent Application Laid-Open No.
0-11352, JP-A 61-141388, JP-A 61-141391 and the like. Further, as a method using a cross-linkable urethane, JP-A-61-1377
No. 32 publication and the like. These cushion materials have inferior durability, and also have problems such as not being recyclable because they are neither thermoplastic nor single composition, and there are problems such as complexity of processability and pollution of chemicals used during manufacturing. .

Polyester hard cotton, for example, JP-A-58-3
1150, JP-A-2-154050, JP-A-3-220354, etc., but since an amorphous polymer having a brittle adhesive component of the heat-bonding fiber used is used (for example, JP-A-58). -136828, Japanese Patent Application Laid-Open No. 3-
However, there is a problem in that durability is poor such that the bonded portion is brittle and the bonded portion is easily broken during use and the form and elasticity are reduced. As an improved method, a method of entanglement treatment has been proposed in Japanese Patent Laid-Open No. 4-245965, but there is a problem that the brittleness of the bonded portion is not solved and the elasticity is largely reduced. In addition, there is complexity during processing. Further, there is a problem that the bonded portion is hard to be deformed and soft cushioning is hard to be imparted. For this reason, the polyester elastomer that is soft even at the bonded portion and recovers even if it is deformed to some extent
A heat-bonding fiber using a non-elastic polyester as a core component is disclosed in JP-A-4-240219, and a cushion material using the fiber is disclosed in WO-91 / 19032, JP-A-5-155651. It is proposed in Japanese Patent Laid-Open No. 5-163654. The adhesive component used in this fiber structure contains 50 to 80 mol% of terephthalic acid in the acid component of the hard segment of polyester elastomer, and the content of polyalkylene glycol as the soft segment is 30 to 50% by weight. %, The melting point of 180 ° C. or lower for other acid component compositions is disclosed in JP-B-60-14.
Since it is recognized that it is the same as the fiber described in the 04 publication,
It contains isophthalic acid, etc., which increases the non-crystallinity, and the low melt viscosity improves the formation of heat-bonded parts to form amoeber-shaped bonded parts. Since it is an elastic polyester, there is a problem that the plastic deformation becomes remarkable especially under heating, and the heat resistance and compression resistance deteriorates.

A thermoplastic olefin network used for civil engineering work 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 olefin, the heat resistance durability is extremely poor and it cannot be used as a cushion material. Further, JP-A-1-207462 discloses a floor mat made of vinyl chloride, but it is not preferable as a cushioning material because it has poor compression recovery at room temperature and remarkably poor heat resistance. .

[0007]

To solve the above problems,
An object of the present invention is to provide a net-like structure and a manufacturing method suitable for a cushioning material which has excellent heat resistance and cushioning properties and does not easily get damp.

[0008]

Means for solving the above object, according to an aspect of, i.e. the invention, the number of loops caused Magarikunera a continuous filament having a different shape <br/> section made of thermoplastic elastomeric resin A network structure having a three-dimensional random loop structure in which the loops are formed and are brought into contact with each other in a molten state to maintain a constant width and thickness in which most of the contact portions are fused, and the network structure 0.01~0.10g / cm ³ apparent density is
In thickness is not less 3mm or more and different shapes of the filament constituting the net-like structure 1. 5 to 5.0 with an average thickness of 0.1 to 5 mm
From Y-shaped cross shape cross section formed of a plurality of orifices having a projection on the network structure and three, characterized in that it is a thermoplastic elastic resin in a molten state at a temperature higher 10 to 60 ° C. above the melting point Discharge and form a number of loops in the molten state, contact each loop and fuse together to form a three-dimensional random loop structure that maintains a constant width and thickness, sandwich it with a take-up device, and continue. different forms of the streaks allowed to cool in the cooling tank 1. The average thickness is 5 to 5.0.
After forming a reticulated structure having a size of 1 to 5 mm, the filaments constituting the reticulated structure have an endothermic peak below the melting point in the melting curve measured by a differential scanning calorimeter This is a method for producing a reticulated structure characterized by performing annealing at a temperature lower by at least 10 ° C or more.

The thermoplastic elastic resin in the present invention is block-copolymerized with a soft segment, such as polyether glycol, polyester glycol, or polycarbonate glycol having a molecular weight of 300 to 5000. Polyester elastomer, polyamide elastomer,
Examples include polyurethane elastomers. By using a thermoplastic elastic resin, it becomes possible to regenerate by remelting, and thus recycling becomes easy. For example, as the polyester 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 illustrated. More specific examples of the polyester ether block copolymer include terephthalic acid, isophthalic acid, naphthalene -2,6- dicarboxylic acid, naphthalene- 2,7- dicarboxylic acid, diphenyl- 4. Aromatic dicarboxylic acids such as 4 - 'dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4- cyclohexanedicarboxylic acid, aliphatic dicarboxylic acids such as succinic acid, adipic acid and sebacic acid dimer acid, or ester formation thereof At least one dicarboxylic acid selected from the group consisting of organic derivatives, 1,4- butanediol, ethylene glycol, trimethylene glycol, tetremethylene glycol, pentamethylene glycol, hexamethylene glycol Le of aliphatic Geo - le, 1,1-cyclohexane dimethanol - le, 1,4-cyclohexane dimethanol - Le like alicyclic Geo - Le Or geo selected from such ester-forming derivatives thereof - at least 1 Le component
And at least one of polyalkylenediol having an average molecular weight of about 300 to 5,000, such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol and ethylene oxide-propylene oxide copolymer. It is a ternary block copolymer. As the polyester ester block copolymer,
The above dicarboxylic acid and diol, and the average molecular weight are about 300.
It is a ternary block copolymer composed of at least one kind of polyester diol such as ˜3000 polylactone. Considering thermal adhesion, hydrolysis resistance, stretchability, heat resistance, etc., the dicarboxylic acid is terephthalic acid,
Or, and naphthalene -2,6- dicarboxylic acid, geo-
1,4- butanediol as the polyol component and polytetramethylene glycol as the polyalkylenediol.
A terblock copolymer or a terpolymer of polylactone as a polyester diol is particularly preferable. In a special case, a polysiloxane-based soft segment may be used. In addition, the above elastomer is blended with a non-elastomer component,
Copolymers and the like are also included in the thermoplastic elastic resin of the present invention. The melting point of the thermoplastic elastic resin of the present invention is preferably 140 ° C. or higher at which heat resistance and durability can be maintained, and it is more preferable to use a resin having a melting point of 160 ° C. or higher because heat resistance and durability are improved. If necessary, an antioxidant, a light-proofing agent or the like may be added to improve durability.

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 significantly improved heat resistance and sag resistance than those having no endothermic peak. Although the reason for this is not clear, it is considered that a pseudo-crystallization-like cross-linking point is formed and the heat resistance and sag resistance is improved. For example, a preferable polyester elastomer of the present invention contains terephthalic acid or naphthalene -2,6- dicarboxylic acid as an acid component in an amount of 90 mol% or more, and more preferably terephthalic acid or naphthalene -2,6- dicarboxylic acid. Content of 95 mol% or more, particularly preferably 100 mol%, after transesterification of the glycol component, polymerized to a required degree of polymerization, and then as a polyalkylene diol,
Preferably, polytetramethylene glycol having an average molecular weight of 500 or more and 5000 or less, particularly preferably 1000 or more and 3000 or less is copolymerized in an amount of 15% by weight or more and 70% by weight or less, more preferably 30% by weight or more and 60% by weight or less. In this case, when the content of terephthalic acid or naphthalene -2,6- dicarboxylic acid is high, the crystallinity of the hard segment is improved, the plastic deformation is less likely to occur, and the heat resistance and sag resistance are improved. After that, if the annealing treatment is further performed at a temperature lower than the melting point by at least 10 ° C. or more, the heat resistance and sag resistance are further improved. If annealing is performed after applying compressive strain, heat resistance and sag resistance are further improved. When the melting curve of the linear structure of the network structure thus treated is measured by a differential scanning calorimeter (DSC), an endothermic peak is more clearly expressed at a temperature of room temperature or higher and melting point or lower. In the case of not annealing, no endothermic peak appears below the melting point. By analogy with this, it is considered that the annealing causes rearrangement of the hard segments and formation of pseudo-crystallization-like cross-linking points to improve the heat resistance and sag resistance.

The cross-section of the filaments constituting the reticulated structure of the present invention is a polygonal cross-section such as a triangle, a quadrangle, a cross, etc. or a cross-section having protrusions on them, a star, a Y-shape, a U-shape, a hollow cross-section. And modified cross sections such as those having a plurality of protrusions. By forming a modified cross-section, anti-compression property can be imparted. The anti-compression property can be adjusted by the modulus of the material used, and the degree of deformation can be increased for soft materials to adjust the gradient of the initial compression stress, and the degree of deformation can be decreased for materials with a slightly higher modulus to provide a comfortable sitting feeling. Imparts excellent anti-compression properties. As another effect of the irregular cross section, by increasing the irregularity, it is possible to reduce the weight when the same anti-compression property is given, and it is possible to save energy when used for a seat of an automobile or the like, and in the case of a futon or the like. Improves the handleability when raising and lowering. The degree of irregularity in the filament of the present invention is 1.5 to 5.0. 1. 5
If it is less than 5, the effect of the deformed shape is insufficient, and if it exceeds 5 , the deformed cross section is easily deformed when stress is applied by a large force from the direction perpendicular to the cross section, and in the extreme case, the seat is deformed. Bends and the shape retention is deteriorated. When the ratio of the longest distance to the shortest distance from the center of gravity of the filament cross section is 1.2 or more and 5 or less, even if a large compressive stress is applied, it is difficult to deform in a certain direction and the anti-compression property is improved.

In the network structure of the present invention, the filaments made of thermoplastic elastic resin are made to meander, and the filaments 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 amount of deformation is applied with a very large stress, the entire fused and integrated three-dimensional network structure deforms and absorbs the stress, and when the stress is released, the rubber elasticity of the elastic resin develops. 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 poor. If they are not fused, the shape cannot be maintained and the structure does not deform integrally, so that fatigue phenomenon occurs due to stress concentration and durability deteriorates, and at the same time, the shape deforms, which is not preferable. The more preferable degree of fusion in the present invention is that most of the portions where the filaments are in contact are fused, and most preferably all the contact portions are in fusion. The average thickness of the filament of the present invention is 0.1 to 5 m.
m.

[0013] is streak made of a thermoplastic elastic resin of the present invention, the apparent density of the network structure that該線conditions together are fused is 0.005 g / cm ³ or more and 0.20 g / cm ³ or less. If the apparent density is less than 0.005 g / cm ³ , the repulsive force will be lost and it is not suitable as a cushioning material.
If it exceeds g / cm ³ , the elasticity becomes strong and the sitting comfort becomes poor, so it is not suitable as a cushion material. The preferred apparent density of the present invention is 0.01 to 0.10 g / c.
m ^3, more preferably from 0.02~0.05g / cm ^3. The thickness of the net-like structure is not particularly limited,
It is preferably 3 mm or more so that the function as a cushion body is easily expressed. The size of the random loop can be arbitrarily selected according to the intended use, but the diameter is 3 to 100 m.
A size of m, especially 5 to 50 mm is suitable.

A wire made of a thermoplastic elastic resin having a meandering shape on the surface of the net-like structure forms a loop, and in the middle of the loop, the thickness direction of the net-like structure is taken as the base line and 4 from the base line.
It is preferable that the contact portion is bent by 5 ° or more, the surface is substantially flattened, and most of the contact portion is fused. As a result, the contact points of the filaments on the surface of the net-like structure are significantly increased to form bonding points, so that local external force is also received by the structure surface, and the surface structure is deformed as a whole, and the entire internal structure Also deforms to absorb the stress, and when the stress is released, the rubber elasticity of the elastic resin is developed and the structure can be restored to the original form. When not substantially flattened, when a local external force is applied, stress concentration may occur selectively on the surface filaments up to the part where the three-dimensional network structure is not adhered. Fatigue may occur due to stress concentration with respect to such external force, and durability may be reduced. When the filaments are made of thermoplastic elastic resin, the entire structure is deformed in the three-dimensional structure portion, so that stress concentration stops, but in non-elastic resin, stress concentrates at the bonding points as it is and structural damage occurs.

Next, the manufacturing method of the present invention will be described. The network structure of the present invention has a melting point of 1 or more from a plurality of orifices having a plurality of modified cross-sections formed by using a general melt extruder.
Melted at a temperature of 0 ° C. or more and 60 ° C. or less, for example, JP-A-5
A thermoplastic elastic resin obtained by a known method such as JP-A No. 5-120626 is discharged, and the discharge lines in a molten state having a modified cross section are bent and brought into contact with each other to fuse most contact portions. While forming a three-dimensional structure, it is sandwiched by a take-up device and then cooled in a cooling tank to manufacture a net-like structure. In the present invention, the three-dimensional structure formed by the discharge filament in a molten state is less likely to be relaxed by changing the cross-section of the filament, and conversely, since the flow time at the contact point can be maintained for a long time, the adhesion point is strengthened. it can. When heating for adhesion as described in Japanese Patent Application Laid-Open No. 1-2075, the three-dimensional structure is easily relaxed, a planar structure is formed, and a three-dimensional three-dimensional structure becomes difficult, which is not preferable. Then, in the melting net 3
Dimensional three-dimensional structure Both sides are sandwiched, and the winding discharge lines on both sides that are in a molten state are bent by 45 ° or more to deform and flatten the surface, and at the same time, the contact points with the discharge lines that are not bent are bonded to form a structure. After formation, continuously cooling medium (usually using room temperature water can increase the cooling rate,
It is preferable because it is cheap in terms of cost), and the three-dimensional three-dimensional network structure of the present invention is obtained by rapid cooling. Next, it is drained and dried, but if a surfactant or the like is added to the cooling medium, draining and drying may be difficult, or the thermoplastic elastic resin may swell, which is not preferable. As a preferred method of the present invention, pseudo-crystallization treatment is performed after cooling once. The pseudo-crystallization treatment temperature is at least 10 ° C. lower than the melting point (Tm), and is higher than the α dispersion rising temperature (Tαcr) of Tan δ. This treatment has an endothermic peak below the melting point and does not have pseudo-crystallization treatment (no endothermic peak)
The heat resistance and sag resistance are remarkably improved. The preferred pseudo-crystallization treatment temperature of the present invention is from (Tαcr + 10 ° C.) to (Tαcr + 10 ° C.).
m-20 ° C). If it is pseudo-crystallized by simple heat treatment, heat resistance and sag resistance are improved. However, it is more preferable that the material is cooled once and then subjected to compressive deformation of 10% or more and then uncoiled so that the heat and sag resistance is remarkably improved. When the 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. In addition, a pseudo crystallization process can be performed separately. Then, it is cut into a desired length and used as a cushion material. The desired loop diameter and wire diameter can be determined by the distance between the nozzle surface and the take-up conveyor installed on the cooling medium for solidifying the resin, the melt viscosity of the resin, the orifice hole diameter and the discharge amount, and the like. A pair of take-up conveyors with adjustable spacing installed on the cooling medium sandwiches and holds the melted discharge filaments to fuse the parts that are in contact with each other, and continuously draw in the cooling medium to solidify them. By adjusting the distance between the conveyors when forming the body, the thickness can be adjusted while the fused net-like body 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, and if it is too long, the molten filaments are cooled and the contact portion is not fused, which is not preferable. If the conveyor speed is too high, the formation of contact points may be insufficient, or the contact point may be cooled until the fusion point is sufficiently formed, resulting in insufficient fusion of the contact portion. Further, if the speed is too slow, the melt will stay too much and the density will increase, so it is necessary to set the conveyor speed suitable for the desired apparent density.

When the net-like structure of the present invention is used as a cushion material, a resin used depending on the purpose and site of use,
It is necessary to select the fineness, the loop diameter, and the bulk density. For example, when used for the wadding of the surface layer, it is preferable to have a low density, a fine fineness, and a fine loop diameter in order to give a soft touch, an appropriate subsidence, and a bulge with tension. In order to lower the resonance frequency, linearly change the appropriate hardness and hysteresis at the time of compression to improve body retention, and to maintain durability, medium density, thick fineness, and slightly large ru Diameter is preferred. Further, it can be molded into a shape suitable for the purpose of use by using a molding die or the like to the extent that the three-dimensional structure is not damaged. In addition, the addition of chemicals such as flame retardant, insect repellent antibacterial, heat resistant, water and oil repellency, coloring, aroma, etc. at any stage of processing into a molded product from the manufacturing process within the range that does not reduce performance Can be processed.

[0017]

EXAMPLES The present invention will be described in detail below with reference to examples.

The evaluations in the examples were carried out by the following methods. From the cross-section photograph of the irregularity line, the area of the circumscribed circle of the line cross section is divided by the cross-sectional area of the line cross section, and the average value of n = 10 is shown. Melting point (Tm) and endothermic peak below melting point TA50, DSC50 type differential thermal analyzer manufactured by Shimadzu Corporation was used, and the endothermic peak (melting peak) was measured from the endothermic curve measured at a temperature rising rate of 20 ° C./min. ) The temperature was determined. Tαcr polymer is heated to the melting point + 10 ° C and the thickness is about 300 μm.
Film was prepared and measured using a Vibron DDVII type manufactured by Orientec Co., Ltd. at a rate of 110 Hz and a heating rate of 1 ° C./min. Tan δ (the ratio of the imaginary elastic modulus M ″ to the real part M ′ of the elastic modulus M ″ / The rising temperature of α dispersion corresponding to the transition temperature from the rubber elastic region to the melting region of M ′). The apparent bulk density sample is cut into a size of 15 cm × 15 cm, the heights at four places are measured, the volume is determined, and the weight of the sample is divided by the volume. (Average value of n = 4) Whether or not the fusion-bonded sample is fusion-bonded by visual judgment is that the fibers that are adhered are pulled by hand and cannot be detached to decide. Heat resistance and durability (residual strain at 70 ° C) Cut a sample into a size of 15 cm x 15 cm, compress it by 50%, leave it in dry heat at 70 ° C for 22 hours, cool it to remove the compression strain, and leave it for 1 day before treatment. The thickness ratio of is shown in% (n =
The average value of 3) Cyclic compression strain sample is cut into a size of 15 cm x 15 cm, and is 50% in a RH room at 25 ° C and 65% with a Shimadzu Servo Pulser.
The compression recovery was repeated at a cycle of 1 Hz to the thickness of 20,000 times, and the ratio of the thickness of the sample after standing 20,000 times to the thickness before treatment was%.
Indicate. (Average value of n = 3) A 50% compression repulsive force sample was cut into a size of 20 cm × 20 cm, and was compressed to 65% with a φ150 compression plate by Orientec Tensilon. Repulsive force at 50% compression is shown. (Average value of n = 3)

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

[0020]

[Table 1]

As the polyurethane elastomer, 4,
4'-diphenylmethane diisocyanate (MDI) and P
Polymerization by adding TMG and 1,4-BD as a chain extender
Pelletized and vacuum dried to produce polyether urethane
Used as a thermoplastic elastic resin raw material. Melting point of the obtained polymer
152 ° C, PTMG content 64%, Tαcr -10
It was ℃. (Experiment No. A-4)

The thermoplastic elastic resin raw material thus obtained is applied with a width of 50c.
A single-hole discharge rate of 2.0 g / min from a nozzle in which Y-shaped orifices with protrusions at 3 locations on the effective surface of a nozzle of 5 m in length and 5 cm are arranged at intervals of 10 mm in the width direction and 5 mm in the length direction. Discharge and place cooling water 20 cm below the nozzle surface, width 60 cm
The stainless steel endless nets are arranged in parallel at 5 cm intervals so that a pair of take-up conveyors are arranged so as to partially come out on the water surface, and then taken up, while fusing the contact parts while sandwiching both sides at a speed of 1 m / min. After being drawn into cooling water at 25 ° C. to be solidified and then pseudo-crystallized in a hot-air dryer at 100 ° C. for 20 minutes, or air-dried without pseudo-crystallization and cut into a predetermined size, a net-like structure Got The properties of the obtained network structure are shown in Table 2.

[0023]

[Table 2]

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

Comparative Examples 3 to 4 The elastomer of Experiment No. 2 was used and the discharge rate was 0.3 g /
And a take-up conveyor speed of 2 m / min, and a net-like structure obtained in the same manner as in Example 4 with a discharge rate of 6.5 g.
/ Min and the take-up conveyor speed was 50 cm / min, the properties of the net-like structure obtained in the same manner as in Example 4 are shown in Table 2.
Shown in.

Comparative Example 5 The characteristics of the reticulated structure obtained under the same conditions as in Example 4 except that the elastomer of Experiment No. 2 was used and the orifice shape of the nozzle was a circular cross section with a hole diameter of 0.5 mm. 2 shows.

Comparative Example 6 Table 2 shows a part of the characteristics of the reticulated structure obtained in the same manner as in Example 2 except that a take-up conveyor net was placed 60 cm below the nozzle surface and the net was taken out. Since the adhered state is poor, the shape retention is poor and the performance has not been evaluated.

Example 1 is a net-like structure suitable for a cushioning material that is soft and has an appropriate degree of sinking and has good heat resistance and durability. Examples 2, 3, and 4 are slightly hard and have a good shape retention property. 2 is an example of a net-like structure suitable for a cushioning material having good heat resistance and durability. Comparative Examples 1 and 2 are examples using a thermoplastic non-elastic resin, which does not have an endothermic peak below the melting point even when subjected to pseudo-crystallization treatment, has a significantly poor heat resistance durability, and is hard and comfortable to sit on. This is an extremely bad example which is not suitable for a cushion material. Comparative Example 3 is an example having a low apparent bulk density and is not suitable for a cushioning material having a remarkably floor-like feeling and poor sitting comfort because of low repulsive stress at the time of compression. Comparative Example 4 is an example in which the apparent bulk density is extremely high, and the heat resistance and sag resistance and the durability are largely reduced, and it is hard and uncomfortable to sit on, and is not suitable as a cushion material. Comparative Example 5 in cross-section rather different form, the cushion material reduction in resistance and durability or the heat resistance is increased in the example just round cross-section is undesirable. Comparative Example 6 is an example in which fibers are not fused to each other.
The shape retention is extremely poor and it is not suitable as a cushion material.

[0029]

INDUSTRIAL APPLICABILITY The reticulated structure of the present invention uses a thermoplastic elastic resin, and by deforming the cross section of the filament, heat resistance and bulkiness are improved, and the softness peculiar to the thermoplastic elastic resin is improved to a suitable degree. Since it is a net-like structure that has a compression repulsion force and is a mesh-like body that does not get stuffy and is comfortable to sit in, and is easy to recycle, it is useful for vehicle seats, boat seats, furniture cushions, and bedding products. Is. It can be used alone or in combination with other materials. Furthermore, it can be used by various processes for stretchable nonwoven fabric applications.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-109670 (JP, A) JP-A-3-8855 (JP, A) JP-A-5-321119 (JP, A) JP-A-63- 295712 (JP, A) JP 5-329281 (JP, A) JP 5-261184 (JP, A) JP 4-245965 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D04H 1/00-18/00 B68G 1/00-15/00

Claims (2)

(57) [Claims] 1. A form a plurality of loops so Magarikunera a continuous filament having a different shape cross-section made of a thermoplastic elastic resin, and contacted loops each from each other molten state, the majority of the contact portion is fusion A three-dimensional random loop structure mesh structure having a fixed width and thickness, which has an apparent density of 0.01 to 0.10 g / cm ³ and a thickness of 3 mm or more, And the difference in the filaments that make up the mesh structure
Shape degree 1. A reticulated structure having an average thickness of 5 to 5.0 and a thickness of 0.1 to 5 mm. 2. Description of the Y-shaped cross shape cross section formed of a plurality of orifices having a protrusion in three places, to eject a thermoplastic elastic resin in a molten state at a temperature higher 10 to 60 ° C. than the melting point, in the molten state Forming a large number of loops, contacting each loop, forming a three-dimensional random loop structure having a constant width and thickness by fusing, sandwiched by a take-up device,
Subsequently different shape of the streaks allowed to cool in the cooling tank 1. 5
After forming a net-like structure having an average thickness of 0.1 to 5 mm at ˜5.0, the filaments constituting the reticular structure have melting points below the melting point in a melting curve measured by a differential scanning calorimeter. A method for producing a reticulated structure, which comprises performing annealing at a temperature lower than the melting point by at least 10 ° C. so as to have an endothermic peak.